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Experimental and computational study of smoke dynamics from multiple fire sources inside a large-volume building

Building Simulation 2021年第4期14卷 1147-1161页

作者： Gabriele Vigne Wojciech Węgrzyński Alexis Cantizano Pablo Ayala Guillermo Rein Cándido gutiérrez-Montes Fluid Dynamics Division of the Department of Mining and Mechanical Engineering Universidad de JaénJaénSpain Institute for Research in Technology ICAIUniversidad Pontificia ComillasMadridSpain Building Research Institute(ITB) WarsawPoland Imperial College London LondonUK JVVA Fire&Risk MadridSpain

Fire in large-volume buildings poses separate and distinct challenges from compartmented *** particular,the risk it poses on life safety is mostly due to the smoke it produces,its effects on the evacuation process,and how it can affect the firefighters when they approach the building to fight the fire and rescue the *** is why smoke control in large-volume enclosures is of utter importance for life safety,property protection and business *** research presents an experimental and numerical study of the smoke dynamics from four fire sources(combined heat release rate of 5.2 MW)with different ignition times and under transient ventilation conditions,inside a 20 m high cubic *** measurements in the plume and close to the walls have been recorded using 59 *** data was used in the determination of the smoke layer interface height,with the least-square and the N-Percent *** show that significantly worse conditions are induced by multiple sources than those in a single fire of equal *** results have been obtained using the computational fluid dynamics code FDS(Fire Dynamics Simulator,v6.7.1).The comparison shows that in the far field the temperature predictions are accurate inside the smoke layer(10 m and 15 m)with discrepancies lower than 10%,whereas higher significant discrepancies were observed at the smoke layer interface,i.e.5 m high,with discrepancies up to 20%.Furthermore,a grid analysis has been performed showing that grid resolutions,D*/δ,based on the global HRR of the fire might be sufficient to predict the fire induced conditions far from the *** analysis confirmed the applicability of FDS to the assessment of the smoke dynamics under complex fire conditions away from ***,the present work shows the importance of considering fires with multiple sources due to the faster smoke production compared with single fires.

关键词： experiments simulation fire buildings FDS CFD

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The reaction electronic flux in chemical reactions

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Science China Chemistry 2011年第12期54卷 1982-1988页

作者： CERON María Luisa ECHEGARAY Eleonora gutiRREZ-OLIVA Soledad HERRERA Barbara TORO-LABB Alejandro Laboratorio de Química Teorica Computacional(QTC) Facultad de Química Pontificia Universidad Catolica de Chile

The mechanism of a chemical reaction can be characterized in terms of chemical events that take place during the *** events are bond weakening/breaking and/or bond strengthening/*** reaction electronic flux(REF),a concept that identifies and rationalizes the electronic activity taking place along the reaction coordinate,has emerged recently as a powerful tool for characterizing the mechanism of chemical reactions.A quantitative theory introducing new descriptors for characterizing reaction mechanisms is presented in detail and three illustrative examples are *** nucleophilic substitution reactions the REF indicates that bond breaking or forming events may be leading the electronic activity whereas in the methanol decomposition reaction by copper oxide,the REF allows to discover that consecutive electronic reductions of copper together with bond breaking processes control the course of the reaction.

关键词： reaction mechanisms chemical potential conceptual DFT reaction electronic flux (REF)

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Tu diras!

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2006年

作者： Ana Mart?inez-Lage John guti?errez Harry L. Rosser with contributions from Stasie C. Harrington.

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A review of feed efficiency in swine:biology and application

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Journal of Animal Science and Biotechnology 2015年第4期6卷 369-377页

作者： John F.Patience Mariana C.Rossoni-Seräo Nestor A.gutiérrez Department of Animal Science Iowa State University

Feed efficiency represents the cumulative efficiency with which the pig utilizes dietary nutrients for maintenance, lean gain and lipid accretion. It is closely linked with energy metabolism, as the oxidation of carbon-containing components in the feed drive all metabolic processes. While much is known about nutrient utilization and tissue metabolism, blending these subjects into a discussion on feed efficiency has proven to be difficult. For example, while increasing dietary energy concentration will almost certainly increase feed efficiency, the correlation between dietary energy concentration and feed efficiency is surprisingly low. This is likely due to the plethora of non-dietary factors that impact feed efficiency, such as the environment and health as well as individual variation in maintenance requirements, body composition and body weight. Nonetheless, a deeper understanding of feed efficiency is critical at many levels. To individual farms, it impacts profitability. To the pork industry, it represents its competitive position against other protein sources. To food economists, it means less demand on global feed resources. There are environmental and other societal implications as well. Interestingly, feed efficiency is not always reported simply as a ratio of body weight gain to feed consumed. This review will explain why this arithmetic calculation, as simple as it initially seems, and as universally applied as it is in science and commerce, can often be misleading due to errors inherent in recording of both weight gain and feed intake. This review discusses the importance of feed efficiency, the manner in which it can be measured and reported, its basis in biology and approaches to its improvement. It concludes with a summary of findings and recommendations for future efforts.

关键词： Caloric efficiency Energy Feed efficiency Residual feed intake Swine

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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

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Natural compounds and extracts from Mexican medicinal plants with anti-leishmaniasis activity: An update

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Asian Pacific Journal of Tropical Medicine 2017年第12期10卷 1105-1110页

作者： Gabriel Alfonso gutiérrez-Rebolledo Susan Drier-Jonas María Adelina Jiménez-Arellanes Unidad de Investigación Médica en Farmacología Hospital de EspecialidadesCentro Médico Nacional Siglo XXIInstituto Mexicano del Seguro SocialAv. Cuauhtémoc 330Col. DoctoresDelg. Cuauhtémoc06720 Ciudad de MéxicoMexico

Leishmaniasis is considered as an emerging, uncontrolled disease and is endemic in 98 countries. Annually, about 2 million cases of cutaneous and 500000 cases of visceraltype leishmaniasis are recorded and 60000 persons died from the disease. In Mexico,cutaneous leishmaniasis is known as chiclero's ulcer and is reported in 22 states, it is considered as a health problem. For its treatment, pentavalent antimonial drugs are administered. These drugs cause severe side effects, are costly. Drug-resistant cases have been reported and have been developing for over 70 years. One alternative to the drugs that are currently available is to find active molecules in medicinal plants. Dihydrocorynantheine, corynantheine and corynantheidine are active against Leishmania major,while harmane, pleiocarpin, buchtienin, luteolin and quercetin are active against Leishmania donovani. In Mexico, about 20 medicinal plants have been evaluated against Leishmania mexicana, among which the most active are Tridax procumbens, Lonchocarpus xuul and Pentalinon andrieuxii. From these plants, active compounds with IC_(50)≤30 mg/mL or m M have been isolated, such as 3(S)-16,17-didehydrofalcarinol or Oxylipin, cholestra-4,20,24-trien-3-one or pentalinosterol, 24-methylcholest-4-24(28)-dien-3-one, cholest-4-en-3-one, 6,7-dihydroneridie-none, neridienone, cholest-5,20,24-trien-3β-ol, and isocordoin. Today, only pentalinonsterol has been synthesized and assayed in the visceral leishmaniasis experimental model using BALB/c mice infected with Leishmania donovani. Liposome formulation of this compound administered by intravenous route at 2.5 mg/kg showed a significant reduction of parasite load in mouse liver and spleen.

关键词： Active extracts Leishmaniasis Antileishmanicidal activity Natural compounds Mexican medicinal plants

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Glucose-6-phosphate-dehydrogenase deficiency and its correlation with other risk factors in jaundiced newborns in Southern Brazil

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Asian Pacific Journal of Tropical Biomedicine 2011年第2期1卷 110-113页

作者： Clarissa gutirrez Carvalho Simone Martins Castro Ana Paula Santin Carina Zaleski Felipe gutirrez Carvalho Roberto Giugliani Genetics Service Hospital de Clinicas de Porto AlegrePGP in PediatricsUFRGS Pharmacy School UFRGS Medical School UFRGS

Objective:To evaluate the correlation between glucose-6-phosphate-dehydrogenase(G6PD) deficiency and neonatal ***:Prospective,observational case-control study was conducted on 490 newborns admitted to Hospital de Clinicas de Porto Alegre for phototherapy, who all experienced 35 or more weeks of gestation,from March to December *** screening of G6PD activity was performed,followed by ***:There was prevalence of 4.6% and a boy-girl ratio of 3:1 in jaundiced *** jaundiced neonate with ABO incompatibility presented G6PD deficiency,and no Mediterranean mutation was found.A higher proportion of deficiency was observed in *** was no association with UGT1A1 variants. Conclusions:G6PD deficiency is not related to severe hyperbilirubinemia and considering the high miscegenation in this area of Brazil,other gene interactions should be investigated.

关键词： Glucosephosphate dehydrogenase Jaundice Hyperbilirubinemia Neonatal Hemoglobin

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Relationships between soil pollution by heavy metals and melanin-dependent coloration of a fossorial amphisbaenian reptile

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Integrative Zoology 2022年第4期17卷 596-607页

作者： JoséMARTÍN Pablo RECIO Gonzalo RODRÍGUEZ-RUIZ Isabel BARJA Eduardo gutiÉRREZ Luis VGARCÍA Departamento de Ecología Evolutiva Museo Nacional de Ciencias NaturalesCSICMadridSpain Departamento de Zoología Facultad de BiologíaUniversidad Autónoma de MadridMadridSpain Centro de Investigación en Biodiversidad y Cambio Global(CIBC-UAM) Universidad Autónoma de MadridMadridSpain Departamento de Biogeoquímica Ecología Vegetal y MicrobianaInstituto de Recursos Naturales y Agrobiología de SevillaCSICSevillaSpain

Melanin is the basis of coloration in many animals,and although it is often used in communication,thermoregulation,or camouflage,melanin has many other physiological *** example,in polluted habitats,melanin can have a detoxifying *** coloration would help to sequester in the skin the heavy metal contaminants from inside the body,which will be expelled to the exterior when the skin is ***,animals should have evolved more melanic colorations in more polluted habitats(“industrial melanism”hypothesis).We examined whether the fossorial amphisbaenian reptile,Trogonophis wiegmanni,is able to eliminate heavy metals,derived from soil pollution by seagull depositions,through sloughing its *** results suggest a covariation between levels of soil pollution by heavy metals and the concentration of heavy metals in the sloughed skins of *** suggests that amphisbaenians may expel heavy metals from their bodies when they slough the *** also tested whether amphisbaenians inhabiting soils with higher levels of heavy metal pollution had darker(melanin-dependent)body ***,contrary to predictions from the“industrial melanization”hypothesis,we found a negative relationship between soil pollution and proportions of melanic *** contradictory result could,however,be explained because heavy metals have endocrine disruption effects that increase physiological stress,and higher stress levels could result in decreased *** suggest that although amphisbaenians might have some detoxifying mechanism linked to melanin in the skin,this process might be negatively affected by stress and result ineffective under conditions of high soil pollution.

关键词： amphisbaenians coloration fossorial reptiles heavy metals melanin soil pollution

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A review on the parasitic isopod genus Notophryxus ***,1883(Crustacea:Isopoda),and first report of Notophryxus globularis ***,1885 from Lakshadweep Sea(Amini Island)

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Acta Oceanologica Sinica 2024年第8期43卷 142-153页

作者： Mukkattu Nazar Suhaana Jaime Gómez-gutiérrez Paravanparambil Rajakumar Jayachandran Punnakkal Hari Praved Sivasankaran Bijoy Nandan Department of Marine Biology Microbiology and BiochemistrySchool of Marine SciencesCochin University of Science and TechnologyKochi-Kerala 682016India Departamento de Plancton y Ecología Marina Centro Interdisciplinario de Ciencias MarinasInstituto Politécnico NacionalLa Paz B.C.S.23096Mexico Applied Research Centre for Environment and Marine Studies King Fahd University of Petroleum and MineralsDhahran 31261Saudi Arabia

Isopod crustaceans of the family Dajidae are exclusively marine *** genus Notophryxus ***,1883 currently includes nine nominal species,which are very rarely reported as the chances for encountering these specimens are *** comprehension of the taxonomy,biology,ecology,and life cycle of species belonging to the Notophryxus genus is notably *** nominal species of Notophryxus genus are reviewed here to obtain a comprehensive and integrative taxonomic understanding of this genus,in an attempt to address the *** paper also documents the rediscovery of an ectoparasitic isopod from the genus Notophryxus in Indian waters,after 55 *** isopod specimens obtained from the outer reefs of Amini Island in the Lakshadweep archipelago,Southeastern Arabian Sea,display morphological congruence to Notophryxus globularis ***,*** only previous report on this species dates back to 1885 from ***'description of *** as an ectoparasite on the euphausiid Thysanoessa gregaria ***,1883 in the North *** discovery represents a range extension of *** from the North Pacific to the Arabian *** cryptoniscid larvae and three adult females of ***(with dwarf males)were found attached to four adult mysid specimens of Siriella aequiremis Hansen,*** present study provides an improved diagnosis of *** with the aid of light microscopy images and line drawings which was not given in the original ***,1885 *** research also provides a concise description of cryptoniscid larvae from the same sampling location and same host which is most likely to be *** larvae.

关键词： Dajiidae Mysid cryptoniscan larvae Southeastern Arabian Sea Notophryxus

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Subclinical carotid atherosclerosis predicts all-cause mortality and cardiovascular events in obese patients with negative exercise echocardiography

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World Journal of Cardiology 2019年第1期11卷 24-36页

作者： Rafael Vidal-Perez Raúl Franco-gutiérrez alberto J Pérez-Pérez Virginia Franco-gutiérrez alberto Gascón-Vázquez Andrea López-López Ana María Testa-Fernández Carlos González-Juanatey Department of Cardiology Hospital Universitario Lucus Augusti Department of Otolaryngology Hospital Carmen y Severo Ochoa Faculty of Medicine University of Santiago de Compostela

BACKGROUND Obesity is a major health problem due to its high prevalence. The relationship between obesity and cardiovascular disease is unclear. Some studies agree that certain conditions associated with obesity, such as physical inactivity or cardiovascular risk factors, are responsible for cardiovascular risk excess among obese people. Carotid intima-media thickness and carotid plaques(CP) have been associated with cardiovascular adverse events in healthy populations, and recent data suggest a higher prevalence of subclinical carotid atherosclerosis in obese and metabolically unhealthy patients. However, there are no studies correlating subclinical atherosclerosis and adverse events(AE) in obese *** To determine the association between carotid disease and AE in obese patients with negative exercise echocardiography(EE).METHODS From January 1, 2006 to December 31, 2010, 2000 consecutive patients with a suspicion of coronary artery disease were submitted for EE and carotid ultrasonography. Exclusion criteria included previous vascular disease, left ventricular ejection fraction < 50%, positive EE, significant valvular heart disease and inferior to submaximal EE. An AE was defined as all-cause mortality,myocardial infarction and cerebrovascular accident. Subclinical atherosclerosis was defined as CP presence according to Manheim and the American Society of Echocardiography *** Of the 652 patients who fulfilled the inclusion criteria, 226(34.7%) had body mass indexes ≥ 30 kg/m2, and 76 of them(33.6%) had CP. During a mean follow-up time of 8.2(2.1) years, 27 AE were found(11.9%). Mean event-free survival at 1, 5 and 10 years was 99.1%(0.6), 95.1%(1.4) and 86.5%(2.7), respectively. In univariate analysis, CP predicted AE [hazard ratio(HR) 2.52, 95% confidence interval(CI) 1.17-5.46; P = 0.019]. In multivariable analysis, the presence of CP remained a predictor of AE(HR 2.26, 95%CI 1.04-4.95, P = 0.041). Other predictors identified were glomerular

关键词： Carotid intima media thickness Carotid plaque Carotid disease Myocardial infarction Mortality Stroke Exercise stress echocardiography

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