Health monitoring of reinforced concrete slabs subjected to earthquake-type dynamic loading via measurement and analysis of acoustic emission signals

Antolino Gallego,Amadeo Benavent-Climent,Cristóbal Infantes 국제구조공학회 2011 Smart Structures and Systems, An International Jou Vol.8 No.4

This paper discusses the applicability of Acoustic Emission (AE) to assess the damage in reinforced concrete (RC) structures subjected to complex dynamic loadings such as those induced by earthquakes. The AE signals recorded during this type of event can be complicated due to the arbitrary and random nature of seismicity and the fact that the signals are highly contaminated by many spurious sources of noise. This paper demonstrates that by properly filtering the AE signals, a very good correlation can be found between AE and damage on the RC structure. The basic experimental data used for this research are the results of fourteen seismic simulations conducted with a shake table on an RC slab supported on four steel columns. The AE signals were recorded by several low-frequency piezoelectric sensors located on the bottom surface of the slab. The evolution of damage under increasing values of peak acceleration applied to the shake table was monitored in terms of AE and dissipated plastic strain energy. A strong correlation was found between the energy dissipated by the concrete through plastic deformations and the AE energy calculated after properly filtering the signals. For this reason, a procedure is proposed to analyze the AE measured in a RC structure during a seismic event so that it can be used for damage assessment.

Microbial diversity and biochemical profile of aguamiel collected from Agave salmiana and A. atrovirens during different seasons of year

M. Isabel Enríquez-Salazar,Fabiola Veana,Cristóbal N. Aguilar,Iliana M. De la Garza-Rodríguez,Mercedes G. Lo´pez,Olga M. Rutiaga-Quiñones,Jesú s A. Morlett-Chávez,Raúl Rodríguez-Herrera 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.4

Aguamiel is a beverage produced by some Agave species that is consumed in its fresh or fermented form. Despite its uses and popularity, seasonal effects on its microbial and chemical profiles are unknown. In this study, using aguamiel collected from A. salmiana and A. atrovirens during different seasons, we identified microorganisms by sequencing the 16S and 18S rDNA genes and determined their chemical profiles. In total, 49 microbial strains were identified (38 bacteria and 11 yeasts). The highest richness and biodiversity were observed during winter and summer. Different lactic acid bacteria and yeast genera with potential industrial applications were identified, such as Acetobacter, Lactobacillus, Leuconostoc, and Clavispora. The analysis of the chemical profiles indicated the presence of maltooligosaccharides and fructooligosaccharides, which are associated with human health improvements, during spring in Agave aguamiel. Aguamiel can be used in the food industry due to its microbiological and chemical profiles.

Cytotoxicity Screening of Several Tomato Extracts

Jose´ Luis Guil-Guerrero,Rebeca Ramos-Bueno,Ignacio Rodríguez-García,Cristóbal López-Sánchez 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.1

The cytotoxic effects of extracts of the tomato variety “Racimo” have been evaluated through the use of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay at several concentrations. Three extracts—ethanol–water, petroleum ether, and in vitro digested tomato—exhibited in vitro cytotoxicity against the proliferation of the cultured cancer cell line HT-29. The concentration that caused 50% inhibition of cancer cell growth occurred (GI50) of the different extracts for HT-29 cells was 62.5μg/mL for the petroleum ether extract and 87.0μg/mL for the digested tomato extract. For the ethanol–water extract, it was not possible to determine this parameter at the assayed extract concentrations. These results clearly indicate that after the digestion process, the less polar substances, such as carotenoids and sterols, are bioavailable as active species against cancer cells. The GI50 levels for tomato extracts are similar to those values reported for medicinal plants. The results of the MTT assay on nonmutagenic CCD-18 cells showed a lack of negative effect on cell growth, which indicates that tomato extracts act selectively on HT-29 tumor cells. ^1H-Nuclear magnetic resonance spectra confirmed the presence of known compounds with accepted cytotoxic activity against tumor lines (lycopene and β-carotene). The high cytotoxicity for HT-29 cells showed by the petroleum ether extract might be due to the simultaneous presence in the extract of both carotenoids and glyceryl esters of fatty acids. The results of this work clearly indicate the importance of carotenoid consumption on colon tumor proliferation and prevention, and also the importance of the dietary fats in carotenoid bioavailability.

Juice Extraction from Mango Pulp Using an Enzymatic Complex of Trichoderma sp. produced by Solid-state Fermentation

Juan Buenrostro-Figueroa,Heliodoro de la Garza-Toledo,Vrani Ibarra-Junquera,Cristóbal Noe Aguilar-González 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.5

In this study, 2 Trichoderma strains (T-Ⅰ and T-ⅡI)were evaluated for the production, by submerged (SmF)and solid state fermentation (SSF) of an enzymatic complex with the capacity to degrade the cell components of mango peels, using these as support (in SSF) and source of nutrients. Highest enzymatic activity (7,552.5 units of endo-glucanase/L) was found in T-II by SSF. Efficiency of this crude enzymatic extract in the extraction of mango juice was evaluated, improving the yield up to 79%,representing an alternative to give an added value of mango peels improving the yields of production of mango juice.

Comparison of physicochemical pretreatments of banana peels for bioethanol production

Sócrates Palacios,Héctor A. Ruiz,Rodolfo Ramos-Gonzalez,José Martínez,Elda Segura,Miguel Aguilar,Antonio Aguilera,Georgina Michelena,Cristóbal Aguilar,Anna Ilyina 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.4

Pretreatments with different concentrations of sulfuric acid (0, 0.5, and 1% v/v) and temperatures (28 and 121 C at 103 kPa in an autoclave) were performed on banana peels (BP) milled by mechanical grinding and grinding in a blender as well as without grinding. Cellulose, hemicellulose, lignin, ash, and total and reducing sugar contents were evaluated. The highest yields of cellulose enzymatic hydrolysis (99%) were achieved with liquefied autoclaved BP treated with 0.5 and 1% acid after 48 h of hydrolysis. Ethanol production by Kluyveromyces marxianus fermentation was assayed using hydrolyzed BP at 10, 15, and 20% (w/w). The highest ethanol level (21 g/ L) was reached after 24 h of fermentation with 20% (w/w) BP. Kinetics of the consumption of reducing sugars under this fermentation condition demonstrates the presence of a lag period (about 8 h). Thus, BP are a good source for ethanol production.

J-PLUS: Identification of low-metallicity stars with artificial neural networks using SPHINX

Whitten, D. D.,Placco, V. M.,Beers, T. C.,Chies-Santos, A. L.,Bonatto, C.,Varela, J.,Cristó,bal-Hornillos, D.,Ederoclite, A.,Masseron, T.,Lee, Y. S.,Akras, S.,Borges Fernandes, M.,Caballero, J. Springer-Verlag 2019 Astronomy and astrophysics Vol.622 No.-

<P><I>Context.</I> We present a new methodology for the estimation of stellar atmospheric parameters from narrow- and intermediate-band photometry of the Javalambre Photometric Local Universe Survey (J-PLUS), and propose a method for target pre-selection of low-metallicity stars for follow-up spectroscopic studies. Photometric metallicity estimates for stars in the globular cluster M15 are determined using this method.</P><P><I>Aims.</I> By development of a neural-network-based photometry pipeline, we aim to produce estimates of effective temperature, <I>T</I>eff, and metallicity, [Fe/H], for a large subset of stars in the J-PLUS footprint.</P><P><I>Methods.</I> The Stellar Photometric Index Network Explorer, SPHINX, was developed to produce estimates of <I>T</I>eff and [Fe/H], after training on a combination of J-PLUS photometric inputs and synthetic magnitudes computed for medium-resolution (<I>R</I> ~ 2000) spectra of the Sloan Digital Sky Survey. This methodology was applied to J-PLUS photometry of the globular cluster M15.</P><P><I>Results.</I> Effective temperature estimates made with J-PLUS Early Data Release photometry exhibit low scatter, σ(<I>T</I>eff) = 91 K, over the temperature range 4500 < <I>T</I>eff (K) < 8500. For stars from the J-PLUS First Data Release with 4500 < <I>T</I>eff (K) < 6200, 85 ± 3% of stars known to have [Fe/H] < −2.0 are recovered by SPHINX. A mean metallicity of [Fe/H] = − 2.32 ± 0.01, with a residual spread of 0.3 dex, is determined for M15 using J-PLUS photometry of 664 likely cluster members.</P><P><I>Conclusions.</I> We confirm the performance of SPHINX within the ranges specified, and verify its utility as a stand-alone tool for photometric estimation of effective temperature and metallicity, and for pre-selection of metal-poor spectroscopic targets.</P>