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HVSR analysis of pumice sands for sediment depth characterization:A case study for Guadalajara,Mexico

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 577-591页

作者： Hafid Salgado M. Alejandro Ramírez-Gaytan Adolfo Preciado Christian R.Escudero departamento de Ciencias Exactas Centro Universitario de la CostaUniversidad de GuadalajaraCP.48280 Puerto VallartaJaliscoMéxico departamento de Ciencias Computacionales Centro Universitario de Ciencias Exactas e IngenieríaUniversidad de GuadalajaraCP.44430 GuadalajaraJaliscoMéxico departamento del Hábitat y desarrollo Urbano Instituto Tecnológico y de Estudios Superiores de Occidente(ITESO)CP.45604 TlaquepaqueMéxico

The horizontal to vertical spectral ratio(HVSR)methodology is used here to characterize pumice soils and to image the three-dimensional surface geometry of Guadalajara,*** to other Latin American cities,Guadalajara is exposed to high seismic risk,with the particularity of being the largest urban settlement in Latin America built on pumice *** has not yet been tested to characterize subsoil depths in pumice *** to the questionable use of traditional geotechnical tests for the analysis of pumice soils,HVSR provides an alternative for its characterization without altering its fragile and porous *** this work,resonance frequency(F0)and peak amplitude(A0)are used to constrain the depth of the major impedance contrast that represents the interface between bedrock and pumice *** were compared with borehole depths and other available geotechnical and geophysical data and show good *** of the profiles estimated on the riverbanks that cross the city,reveals different subsoil thickness that could have an impact on different site responses on riverine areas to an eventual *** and academic efforts are combined in this work to characterize depth sediments,an important parameter that impacts the regulations for construction in the city.

关键词： subsoil of Guadalajara shallow soil thickness bedrock depth pumice soil characterization

Palm oil biodiesel:An assessment of PAH emissions,oxidative potential and ecotoxicity of particulate matter

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Journal of Environmental Sciences 2021年第3期33卷 326-338页

作者： Silvana Arias Francisco Molina John R.Agudelo Grupo de Investigación en Gestión y Modelación Ambiental-GAIA Escuela AmbientalFacultad de IngenieríaUniversidad de Antioquia UdeACalle 70 No.52-21MedellínColombia departamento de ingeniería Mecánica Universidad de Antioquia UdeA

This work assessed the impact of fuelling an automotive engine with palm biodiesel(pure,and two blends of 10%and 20%with diesel,B100,B10 and B20,respectively)operating under representative urban driving conditions on 17 priority polycyclic aromatic hydrocarbon(PAH)compounds,oxidative potential of ascorbic acid(OP^(AA)),and ecotoxicity through D aphnia pulex mortality *** diluted with filtered fresh air(WD)gathered in a minitunel,and particulate matter(PM)collected directly from the exhaust gas stream(W/oD)were used for *** showed that PM collecting method significantly impact PAH *** all PAH appeared in both,WD and W/oD,higher concentrations were obtained in the last *** biodiesel concentration in the fuel blend decreased all PAH compounds,and those with 3 and 5 aromatic rings were the most *** biodiesel affected both OP^(AA)and *** B10 and B20 exhibited the same rate of ascorbic acid(AA)depletion,B100 showed significant faster oxidation rate during the first four minutes and oxidized 10%more AA at the end of the test.B100 and B20 were significantly more ecotoxic than *** lethal concentration LC50 for B10 was 6.13 mg/*** was concluded that palm biodiesel decreased PAH compounds,but increased the oxidative potential and ecotoxicity.

关键词： Biodiesel Particulate matter P emissions Oxidative stress Ecotoxicity Daphnia pulex

Geochemistry and Genesis of the Pampean and Post-Pampean Formations (Late Pleistocene-Holocene), Central and Northern Argentina Pampas and Its Adjacent Region—An Approaching Case Study

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Chinese Journal Of Geochemistry 2004年第3期23卷 220-237页

作者： Roberto Torra departamento de Geociencias. Facultad de ingeniería. Universidad Nacional del Nordeste. Avda. Las Heras St. No. 727 H3500COI. Resistencia Chaco Argentina

Littoral siliciclastic shallow marine horizontal conformable beds (a heterolithic succession), Middle to Late Miocene, outcropping in northeastern Argentina (Ituzaingó Formation) and overlying transitional conformable horizontal regolithic mantle-rock bed derived from them (the Pampean and Post-Pampean Formations), were geochemically analyzed. The focus of this study is placed on the application of geochemical parameter and signature analyses related with the aforementioned geological units, which are of subcontinental extension into South America. The encountered results show an outstandingly similar geochemical behaviour between them. The main conclusion is that regolithic mantle-rock beds were derived from the littoral shallow marine mudstone (silty-argillaceous) beds. This is in oposition to previous aeolian processes proposed early in the 50’s and later. These mudstone beds constitute important sections of the littoral shallow marine sequence beds (outcropping HST parasequence). Such regolitization proposed for the Pampean and Post-Pampean Formations predominantly developed in-situ during the Late Pleistocene and Holocene. The main erosional and mobilized agents were the surface free water (pluvial, fluvial and laminar water sheets) and vadose water. So, the wind flows and/or the immense air flow hurricanes are of insignificant sedimentological influence. Otherwise, there is not a proved appropiate sandy-silty reservoir for a reasonable support of the “aeolian hypothesis”, as well as clear aeolian structures settled in the regolithic mantle-rock bed. In spite of these lines of equality textural-structural evidence, the geochemical values for both major elements and trace elements, demonstrate that the Miocene heterolithic marine succession was the mother rock of the overlying regolithic mantle-rock bed, which was formed as an in-situ mantle-rock bed.

关键词：地球化学沉积环境南美大草原洪积世全新世阿根廷东北部地区

Rheological Studies on Glycerol Plasticized Gelatin and Its Blends with Epoxidized Soybean Oil

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Journal of Renewable Materials 2019年第1期7卷 21-30页

作者： E.M.Ciannamea L.A.Castillo R.A.Ruseckaite S.E.Barbosa Instituto de Investigaciones en Ciencia y Tecnología de Materiales(INTEMA) Universidad Nacional de Mar del Plata-CONICETAv.J.B.Justo 4302Mar del PlataB7608FDQArgentina Planta Piloto de ingeniería Química(PLAPIQUI) UNS-CONICETCno.La Carrindanga Km.7Bahía Blanca8000Argentina departamento de ingeniería Química Universidad Nacional del SurAv.Alem 1253Bahía Blanca8000Argentina

Blends of gelatin(Ge)plasticized with varying amounts of glycerol(Gly),buffer solution pH 10 and epoxidized soybean oil(ESO)to enhance hydrophobicity were prepared by mixing and *** were characterized by rheological tests and microscopy to select optimal conditions for scaling up their *** effect of each component on rheological response was analyzed using parallel plate *** of gelatin specimens with PDMS during rheological tests led to reliable and reproducible results since water evaporation was prevented.A gradual increment in ESO concentration led to blends with increased degree of phase separation,as evidenced by optical and confocal *** compatibility between ESO and Ge increased viscosity at high ESO levels,but up to 10%Gly could be replaced with ESO without a significant variation of rheological behavior.

关键词： Rheology renewable plasticizers gelatin blends microstructure

Spectrophotometric determination of the formation constants of Calcium(Ⅱ) complexes with 1,2-ethylenediamine,1,3-propanediamine and 1,4-butanediamine in acetonitrile

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Green Energy & Environment 2017年第1期2卷 51-57页

作者： Jacqueline González González Mónica Nájera-Lara Varinia López-Ramírez Juan Antonio Ramírez-Vázquez José J.N.Segoviano-Garfias Programa de Maestría en Biociencias División de Ciencias de la Vida (DICIVA) Universidad de Guanajuato Campus Irapuato-Salamanca Colegio del Nivel Medio Superior de Salamanca(ENMS) departamento de ingeniería Bioquímica Instituto Tecnológico Superior de Irapuato (ITESI) departamento de Ciencias Ambientales División de Ciencias de la Vida (DICIVA) Universidad de Guanajuato Campus Irapuato-Salamanca

In this work, with the purpose to explore the coordination chemistry of calcium complexes which could work as a partial model of manganese-calcium cluster, a spectrophotometric study to evaluate the stability of the complexes: Calcium(Ⅱ)-1,2-ethylendiamine, Calcium(Ⅱ)-1,3-propanediamine and Calcium(Ⅱ)-1,4-butanediamine in acetonitrile, were carried on. By processing the spectrophotometric data with the HypSpec program allows the determination of the formation constants. The logarithmic values of the formation constants obtained for Calcium(Ⅱ)-1,2-ethylendiamine, Calcium(Ⅱ)-1,3-propanediamine and Calcium(Ⅱ)-1,4-butanediamine were log β_(110) = 4.69, log β_(110)= 5.25 and log β_(110) = 4.072, respectively.

关键词： Calcium(Ⅱ)complexes Solution equilibria Artificial photosynthesis Absorbance molar Speciation

Analysis of the role of diffraction in topographic site effects using boundary element techniques

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Earthquake Science 2013年第5期26卷 341-350页

作者： Juan Gomez Doriam Restrepo Juan Jaramillo Camilo Valencia departamento de ingeniería Civil Universidad EAFITMedellín Colombia

The role played by the diffraction field on the problem of seismic site effects is studied. For that purpose we solve and analyze simple scattering problems under P and SV in-plane wave assumptions, using two well known direct boundary-element-based numerical methods. After establishing the difference between scattered and diffracted motions, and introducing the concept of artificious and physically based incoming fields, we obtain the amplitude of the Fourier spectra for the diffracted part of the response： this is achieved after establishing the connection between the spatial distribution of the transfer function over the studied simple topographies and the diffracted field. From the numerical simulations it is observed that this diffracted part of the response is responsible for the amplification of the surface ground motions due to the geometric effect. Furthermore, it is also found that the diffraction field sets in a fingerprint of the topographic effect in the total ground motions. These conclusions are further supported by observations in the time-domain in terms of snapshots of the propagation patterns over the complete computational model. In this sense the geometric singularities are clearly identified as sources of diffraction and for the considered range of dimensionless frequencies it is evident that larger amplifications are obtained for the geometries containing a larger number of diffraction sources thus resulting in a stronger topographic effect. The need for closed-form solutions of canonical problems to construct a robust analysis method based on the diffraction field is identified.

关键词： Seismic site effects Topographiceffects Elastic wave scattering Diffractionof in-plane waves

Behavior of ductile steel X-braced RC frames in seismic zones

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Earthquake Engineering and Engineering Vibration 2019年第4期18卷 845-869页

作者： Eber Alberto Godínez-Domínguez Arturo Tena-Colunga Facultad de ingeniería Universidad Autónoma de Chiapas Tuxtla Gutiérrez 29050 Mexico departamento de Materiales Universidad Autónoma Metropolitana México City 02200 Mexico

A satisfactory ductile performance of moment-resisting reinforced concrete concentric braced frame structures (RC-MRCBFs) is not warranted by only following the provisions proposed in Mexico’s Federal District Code (MFDC-04). The nonlinear behavior of low to medium rise ductile RC-MRCBFs using steel X-bracing susceptible to buckling is evaluated in this study. The height of the studied structures ranges from 4 to 20 stories and they were located for design in the lakebed zone of Mexico City. The design of RC-MRCBFs was carried out considering variable contribution of the two main lines of defense of the dual system (RC columns and steel braces). In order to observe the principal elements responsible for dissipating the earthquake input energy, yielding mappings for diff erent load-steps were obtained using both nonlinear static and dynamic analyses. Some design parameters currently proposed in MFDC-04 as global ductility capacities, overstrength reduction factors and story drifts corresponding to diff erent limit states were assessed as a function of both the considered shear strength and slenderness ratios for the studied RC-MRCBFs using pushover analyses. Additionally, envelopes of response maxima of dynamic parameters were obtained from the story and global hysteresis curves. Finally, a brief discussion regarding residual drifts, residual drift ratios, mappings of residual deformations in steel braces and residual rotations in RC beams and columns is presented. From the analysis of the obtained results, it is concluded that when a suitable design criterion is considered, good structural behavior of RC-MRCBFs with steel-X bracing can be obtained. It is also observed that the shear strength balance has an impact in the height-wise distribution of residual drifts, and an important “shake-down” eff ect is obtained for all cases. There is a need to improve design parameters currently proposed in MFDC to promote an adequate seismic performance of RC-MRCBFs.

关键词： RC braced-frames seismic design nonlinear dynamic analyses steel-X bracing overstrength collapse mechanism story drifts residual drifts

Robust Disturbance Rejection Based Control with Extended-state Resonant Observer for Sway Reduction in Uncertain Tower-cranes

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International Journal of Automation and computing 2019年第6期16卷 812-827页

作者： Horacio Coral-Enriquez Santiago Pulido-Guerrero John Cortés-Romero Programa de ingeniería Mecatrónica Facultad de IngenieríaUniversidad de San Buenaventura sede BogotáCra.8H No 172-20 Edif.DBBogotáOf204Colombia departamento de ingeniería Eléctrica y Electrónica Facultad de IngenieríaUniversidad Nacional de Colombia sede BogotáCra.30 No 45-03 Edif.453BogotáOf222Colombia

In this paper, the problem of load transportation and robust mitigation of payload oscillations in uncertain tower-cranes is addressed. This problem is tackled through a control scheme based on the philosophy of active-disturbance-rejection. Here, a general disturbance model built with two dominant components: polynomial and harmonic, is stated. Then, a disturbance observer is formulated through state-vector augmentation of the tower-crane model. Thus, better performance of estimations for system states and disturbances is achieved. The control law is then formulated to actively reject the disturbances but also to accommodate the closed-loop system dynamics even under system uncertainty. The proposed control schema is validated via experimentation using a small-scale tower-crane,and compared with other relevant active disturbance rejection control(ADRC)-based techniques. The experimental results show that the proposed control scheme is robust under parametric uncertainty of the system, and provides improved attenuation of payload oscillations even under system uncertainty.

关键词： Active disturbance rejection control(ADRC) extended state observer(ESO) tower-crane control resonant observer disturbance observer linear matrix inequality

Effect of laser shock processing on erosive resistance of 6061-T6 aluminum

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Transactions of Nonferrous Metals Society of China 2016年第6期26卷 1522-1530页

作者： J.IBARRA E.RODRíGUEZ O.JIMéNEZ G.GóMEZ-ROSAS M.FLORES J.VERDUZCO J.CHáVEZ Universidad de Guadalajara Departamento de Ingeniería de Proyectos Universidad de Guadalajara Departamento de Física Centro Universitario de Ciencias Exactas e Ingenierías

Application of laser shock processing （LSP） on 6061-T6 aluminum was made in order to evaluate its response to the erosive wear by silica sand. Impact angles of 15° , 30° , 60° and 90° were tested, two particle speeds （37 and 58 m/s） and two LSP irradiation conditions were used. Erosion marks were characterized by 3D profilometry and SEM analysis was conducted to identify the erosion mechanisms for each tested angle. The results showed a maximum erosive wear at low impact angles （ductile type behavior）. Erosion strength and the erosion mechanisms were not affected by the application of LSP and they were attributed to the high strain rate of the erosion phenomena. A few differences encountered on the erosion plots were explained on the basis of the surface roughness left by the LSP process. The maximum mass loss and the maximum erosion penetration happened in different impact angles （15° and 30° , respectively）. Finally, a well-defined erosion mechanism transition was observed, from cutting action at low impact angle, to crater formation at 90° of incidence.

关键词： 6061-T6 aluminum erosive wear laser shock processing