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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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Output feedback adaptive super twisting sliding mode control for quadrotor UAVs

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control Theory and Technology 2024年第1期22卷 92-105页

作者： Oscar Salas-Peña Jesus DeLeón-Morales Susana V.gutiérrez-Martínez École centrale de Nantes-LS2N UMR 6004 CNRS44300NantesFrance Facultad de Ingeniería Mecánica y Eléctrica Universidad Autónoma de Nuevo León66451San Nicolás de Los GarzaMexico

In this paper, a sliding mode control with adaptive gain combined with a high-order sliding mode observer to solve the tracking problem for a quadrotor UAV is addressed, in presence of bounded external disturbances and parametric uncertainties. The high order sliding mode observer is designed for estimating the linear and angular speed in order to implement the proposed scheme. Furthermore, a Lyapunov function is introduced to design the controller with the adaptation law, whereas an analysis of finite time convergence towards to zero is provided, where sufficient conditions are obtained. Regarding previous works from literature, one important advantage of proposed strategy is that the gains of control are parameterized in terms of only one adaptive parameter, which reduces the control effort by avoiding gain overestimation. Numerical simulations for tracking control of the quadrotor are given to show the performance of proposed adaptive control–observer scheme.

关键词： Adaptive super twisting controller High-order sliding modes observer UAV

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The Effect of Water and Salt Stress on Paspalum dilatatum,a constituent of Pampas Natural Grasslands

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Phyton-International Journal of Experimental Botany 2024年第8期93卷 2009-2018页

作者： claudia A.Porcelli Gerardo Rubio Flavio H.gutiérrez Boem Raul S.Lavado Departamento de Química Facultad de AgronomíaUniversidad de Buenos AiresBuenos AiresC1417DSEArgentina Instituto de Investigaciones en Biociencias Agricolas y Ambientales(INBA) Facultad de AgronomíaUniversidad de Buenos AiresBuenos AiresC1417DSEArgentina

The effects of the salt stress on plant growth are usually increased by the water *** studied the impact of both stresses in simultaneous pulses of drought and salinity on Paspalum *** forage species is native to South America,spread in grasslands in many tropical,subtropical,and temperate areas of the world,and very common in grasslands of the Flooding Pampas of *** what happens in *** compared a pot experiment,a non-stressed control against water stress for a month(midpoint between field capacity and wilting point),and two saline stresses(moderate,6 d·Sm^(−1)and strong,12 d·Sm^(−1)),also for a *** biomass(green leaf;non-leaf green material,and dry material)and roots were harvested,weighed,and analyzed for nitrogen,phosphorus,and *** biomass of all components significantly decreased when both stresses were *** plus strong saline stress reduced by half the total biomasses,compared to the *** proportion of aerial biomass/root biomass ratio as well as aerial green component/dry materials ratio tend to decrease when subjected to both *** concentration in plants was not significantly affected,but phosphorus concentration increased in aerial biomass components,from 0.10 to 0.18 mg·kg^(−1)between the extreme treatments,but did not change in *** concentration in plants increased(i.e.,in green leave sodium(Na)increased from 0.27 to 2.01 mg·kg^(−1)between the extreme treatments),whereas other cations either did not change or decreased,affecting the ratios between *** performance allows us to infer that the Na accumulation of *** behaves in an intermediate range,compared to very tolerant to salts or non-salt tolerant species of the Paspalum *** agreement,when salts were applied in the form of a pulse,*** tolerated higher salinity than that found by other authors for the same species,using continuous salinity.

关键词： Dallis grass salinity drought sodium in plants phosphorus in plants potassium/sodium ratio

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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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Roller Screw and Threaded chain Speed Reducer: An Experimental Evaluation

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Modern Mechanical Engineering 2024年第1期14卷 1-11页

作者： Filiberto gutiérrez Instituto de Ingeniería Universidad Nacional Autónoma de México Mexico City Mexico

We are developing a speed reducer that can be considered a transformation of a worm gear reducer: the worm is replaced by an inverted roller screw, and the gear is replaced by a threaded chain drive. This configuration lessens wear, increases load capacity, and improves efficiency. The threaded chain consists of nut-shaped links. This paper presents the results of tests carried out on a prototype with a reduction ratio of 46.

关键词： Speed Reducer Inverted Roller Screw chain Drive Threaded chain Drive

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THE SUMERIAN TERM u_(8)/ud_(5)/ab_(2)/eme_(3)/_(6)sila_(4)/maš_(2)/amar du_(3)(-a)

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Journal of Ancient civilizations 2024年第1期39卷 1-28,123页

作者： Marcos Such-gutiérrez Facultad de Filosofía y Letras Universidad Autónoma de Madrid

The aim of the present article is twofold:firstly,to prove that the expression animal+young du_(3)(-a),which is basically documented in texts from the 3rd millennium Bc,refers to a dam that has just given birth,and se... 详细信息

关键词： 3rd millennium Bc female animal+young du_(3)(-a) livestock newborn suckling animal UrⅢperiod

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Metal-modulated epitaxy of Mg-doped Al_(0.80)In_(0.20)N-based layer for application as the electron blocking layer in deep ultraviolet light-emitting diodes

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Journal of Semiconductors 2024年第5期45卷 80-89页

作者： Horacio Irán Solís-cisneros carlos Alberto Hernández-gutiérrez Enrique campos-González Máximo López-López Optomechatronics Group Tecnológico Nacional de México Campus Tuxtla Gutiérrezcarretera Panamericana 1080C.P.29050Tuxtla GutiérrezChiapasMéxico Departamento de Física Instituto Nacional de Investigaciones NuclearesCarretera México-Toluca s/nC.P.52750La Marquesa OcoyoacacMéxico Departamento de Física Centro de Investigación y estudios Avanzados del Instituto Politécnico NacionalAv.Instituto Politécnico Nacional 2508San Pedro ZacatencoGustavo A.Madero07360 Ciudad de MéxicoCDMXMéxico

This work reports the growth and characterization of p-AlInN layers doped with Mg by plasma-assisted molecular beam epitaxy(PAMBE).AlInN was grown with an Al molar fraction of 0.80 by metal-modulated epitaxy(MME)with a thickness of 180 nm on Si(111)substrates using AlN as buffer *** substrate temperatures were used to enhance the incorporation of indium atoms into the alloy without clustering,as confirmed by X-ray diffraction(XRD).cathodoluminescence measurements revealed ultraviolet(UV)range ***,Hall effect measurements indicated a maximum hole mobility of 146 cm^(2)/(V∙s),corresponding to a free hole concentration of 1.23×10^(19)cm^(−3).The samples were analyzed by X-ray photoelectron spectroscopy(XPS)estimating the alloy composition and extracting the Fermi level by valence band ***-doped AlInN layers were studied for use as the electron-blocking layer(EBL)in LED *** varied the Al composition in the EBL from 0.84 to 0.96 molar fraction to assess its theoretical effects on electroluminescence,carrier concentration,and electric field,using SILVAcO *** results from this study highlight the importance and capability of producing high-quality Mg-doped p-AlInN layers through *** simulations suggest that an Al content of 0.86 is optimal for achieving desired outcomes in electroluminescence,carrier concentration,and electric field.

关键词： metal-modulated epitaxy AlInN DUV-LED EBL simulation

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Gut microbiota in preterm infants receiving breast milk or mixed feeding

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World Journal of clinical Pediatrics 2024年第2期13卷 135-145页

作者： Sandra Gabriela Sánchez-González Bárbara Gabriela cárdenas-del-castillo Elvira Garza-González Gerardo R Padilla-Rivas Isaías Rodríguez-Balderrama consuelo Treviño-Garza Fernando Félix montes-Tapia Gerardo c Palacios-Saucedo Anthony gutiérrez-Rodríguez Manuel Enrique de-la-O-cavazos Department of Pediatrics Hospital Universitario“Dr.JoséEleuterio González”Universidad Autónoma de Nuevo LeónMonterrey 64460Nuevo LeónMéxico Departamento de Bioquímica y Medicina Molecular Universidad Autónoma de Nuevo LeónMonterrey 64460Nuevo LeónMéxico Department of Biochemistry and Molecular Medicine Universidad Autónoma de Nuevo LeónMonterrey 64460Nuevo LeónMéxico Department of Pediatric Surgery Hospital Universitario"Dr.JoséEleuterio González"Monterrey 64460Nuevo LeónMéxico

BAcKGROUND Preterm birth is the leading cause of mortality in newborns,with very-low-birthweight infants usually experiencing several *** milk is considered the gold standard of nutrition,especially for preterm infants with delayed gut colonization,because it contains beneficial microorganisms,such as Lactobacilli and *** To analyze the gut microbiota of breastfed preterm infants with a birth weight of 1500 g or *** An observational study was performed on preterm infants with up to 36.6 wk of gestation and a birth weight of 1500 g or less,born at the University Hospital ***éEleuterio González at Monterrey,Mexico.A total of 40 preterm neonates were classified into breast milk feeding(BM)and mixed feeding(MF)groups(21 in the BM group and 19 in the MF group),from October 2017 to June *** samples were collected before they were introduced to any feeding *** full enteral feeding was achieved,the composition of the gut microbiota was analyzed using 16S rRNA gene *** variables were compared using Student’s t-test or using the Mann–Whitney U test for nonparametric ***,evenness,equitability,Margalef’s index,Fisher’s alpha,chao-1 index,and Shannon’s diversity index were also *** No significant differences were observed at the genus level between the *** comparison indicated higher counts of Alphaproteobacteria and Betaproteobacteria in the initial compared to the final sample of the BM group(Pcounts of Gammaproteobacteria were detected in the final than in the initial sample(P=0.040).According to the Margalef index,Fisher’s alpha,and chao-1 index,a decrease in species richness from the initial to the final sample,regardless of the feeding type,was observed(Pcteroidetes,Actinobacteria,Firmicutes,and Proteobacteria,with Proteobacteria being the most ***,no significant differences were

关键词： Gut microbiota Human milk Preterm infant Proteobacteria Very low birth weight 16S rRNA

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clinical features of chronic kidney disease in dogs with the serological presence of Leptospira spp.,Ehrlichia canis,and Anaplasma phagocytophilum

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Animal Diseases 2024年第3期4卷 224-230页

作者： claire A.Vázquez‑Manzanilla María F.cárdenas‑Marrufo Eduardo gutiérrez‑Blanco Matilde Jiménez‑coello Nelly R.Pech‑Sosa Antonio Ortega‑Pacheco Departamento de Salud Animal y Medicina Preventiva Facultad de Medicina Veterinaria y ZootecniaCampus de Ciencias Biológicas y AgropecuariasUniversidad Autónoma de YucatánMéridaYucatán 97100México Unidad Interinstitucional de Investigación clínica y Epidemiológica Facultad de MedicinaUniversidad Autónoma de YucatánMéridaYucatán 97000México

chronic kidney disease is commonly diagnosed in dogs,and clinical signs may be aggravated when infected agents are *** this case report,33 dogs with chronic kidney disease were clinically evaluated and serologically tested for Leptospira spp.,Ehrlichia canis,and Anaplasma *** seroprevalence for Leptospira *** 39.4%.The most frequent serovars found were Pyrogenes,canicola,Bratislava and Australis,with serological titers between 1:100 to 1:*** signs included fever,depression,decreased body condition,vomiting and hema‑*** laboratory fndings were anemia,leukocytosis,thrombocytopenia,increased liver enzymes,urea and creatinine,hyperbilirubinemia and *** leptospira seronegative dogs were positive for one or both monitored homoparasites(i.e.,*** and ***);only three leptospira seropositive dogs were positive for one or both *** also suggest that endemic hemoparasites of dogs should be moni‑tored in dogs with a kidney condition for a better clinical picture of the patients and therapeutic approach.

关键词： Anaplasma chronic kidney disease Dog Ehrlichia Leptospira

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Single atom cu-N-c catalysts for the electro-reduction of cO_(2) to cO assessed by rotating ring-disc electrode

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Journal of Energy chemistry 2024年第1期88卷 169-182,I0004页

作者： S.Pérez-Rodríguez M.gutiérrez-Roa c.Giménez-Rubio D.Ríos-Ruiz P.Arévalo-cid M.V.Martínez-Huerta A.Zitolo M.J.Lázaro D.Sebastián Instituto de carboquímica(cSIc) Miguel Luesma Castán 450018 ZaragozaSpain Instituto de catálisis y Petroleoquímica(cSIc) Marie Curie 228049 MadridSpain Synchrotron SOLEIL L’Orme des MerisiersDépartementale 12891190France

The electrochemical cO_(2) reduction reaction(cO_(2)RR) to controllable chemicals is considered as a promising pathway to store intermittent renewable energy. Herein, a set of catalysts based on copper-nitrogendoped carbon xerogel(cu-N-c) are successfully developed varying the copper amount and the nature of the copper precursor, for the efficient cO_(2)RR. The electrocatalytic performance of cu-N-c materials is assessed by a rotating ring-disc electrode(RRDE), technique still rarely explored for cO_(2)RR. For comparison, products are also characterized by online gas chromatography in a H-cell. The as-synthesized cu-Nc catalysts are found to be active and highly cO selective at low overpotentials(from -0.6 to -0.8 V ***) in 0.1 M KHcO_(3), while H_(2) from the competitive water reduction appears at larger overpotentials(-0.9 V vs. RHE). The optimum copper acetate-derived catalyst containing cu-N_(4) moieties exhibits a cO_(2)-to-cO turnover frequency of 997 h^(-1) at -0.9 V vs. RHE with a H_(2)/cO ratio of 1.8. These results demonstrate that RRDE configuration can be used as a feasible approach for identifying electrolysis products from cO_(2)RR.

关键词： cu-N-c carbon xerogel Rotating ring disc electrode carbon dioxide reduction reaction carbon monoxide

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