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A study of fire propagation in coal seam with numerical simulation of heat transfer and chemical reaction rate in mining field

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International Journal of Mining Science and Technology 2019年第6期29卷 873-879页

作者： Moisés Oswaldo bustamante rúa Alan José Daza Aragón Pablo bustamante Baena National University of Colombia Cr 65 # 63 20 CIMEX Minerals Institute

Spontaneous combustion of coal is a problem that affects the mining operation and generates environ-mental,economic,social and geotechnical *** phenomenon has been divided into two pro-cesses:ignition and *** propagation develops in coal seams because of a set of factors such as direction and wind speed,fracturing and *** this work,heat transfer and chemical kinetics are studied from conservation equations of energy and species,respectively,using the software COMSOL Multiphysics to simulate the propagation of fires in coal *** possible scenarios were analyzed that usually occur in the walls of the coal seams,such as fire focus and fire complete *** was found that the propagation kinetics of the fire changes depending on the temperature,the fractur-ing of rock mass and the area of fire *** temperature values lower than 300℃,there is con-sumption around 250 cm^3/h,values around 700℃,the consumption is 1500 cm^3/h,and for fires of 1200℃ have values of 3000 cm^3/*** on the speed of propagation can vary from 4 to 17cm/day,considering on the level and fracturing of the final wall of the open pit.

关键词： Spontaneous combustion of coal Open pit mines Simulation Heat transfer Chemical reaction COMSOL

Statistical analysis to establish an ignition scenario based on extrinsic and intrinsic variables of coal seams that affect spontaneous combustion

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International Journal of Mining Science and Technology 2019年第5期29卷 731-737页

作者： M.O.bustamante rúa A.J.Daza Aragón P.bustamante Baena J.D.Osorio Botero school mines national university of colombiamedellín 050036colombia

Spontaneous combustion of coal seams in open pit mines is a problem that occurs in coal mines around the *** have been developed that express several factors which generate self-heating in the coal and favor *** synergy of these factors contributes to the increase in the temperature of oxidation reactions,facilitating the culmination of the activation energy of the system,in which the ignition develops and the reaction is ***,the incidence of each variable’s susceptibility to coal combustion is unknown,so in this work a methodology was developed to determine statistically which of the variables has the greatest contribution in the *** statistics,atypical values detection,principal component determination,cluster analysis,and logistic regression were used to determine how many indicator variables are necessary to describe susceptibility to coal *** the analysis,21,000 data from different seams of two open-pit coal mines in endwalls and abandoned pits were processed with consideration given to extrinsic and intrinsic *** temperature,atmospheric pressure,wind speed,oxygen,methane,height,ash,volatile matter,heat power,vitrinite,liptinite and the Hardgrove Index are the most influential variables in the phenomenon.

关键词： Coal fire Self-ignition Statistics analysis Open pit mines Spontaneous combustion

How to avoid overtreatment of benign colorectal lesions:rationale for an evidence-based management

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World Journal of Gastroenterology 2022年第47期28卷 6619-6631页

作者： Marco bustamante-Balén Gastrointestinal Endoscopy Unit Gastrointestinal Endoscopy Research GroupHospital Universitari Ⅰ Politècnic La FeHealth Research Institute Hospital La Fe(ⅡSLaFe)Valencia 46026Spain

Implementing population-based screening programs for colorectal cancer has led to an increase in the detection of large but benign histological ***,endoscopic mucosal resection can be considered the standard technique for the removal of benign lesions of the colon due to its excellent safety profile and good clinical ***,several studies from different geographic areas agree that many benign colon lesions are still referred for ***,the referral rate to surgery is not decreasing over the years,despite the theoretical improvement of endoscopic resection *** article will review the leading causes for benign colorectal lesions to be referred for surgery and the influence of the endoscopist experience on the referral *** will also describe how to categorize a polyp as complex for resection and consider an endoscopist as an expert in endoscopic *** finally,we will propose a framework for the accurate and evidence-based treatment of complex benign colorectal lesions.

关键词： Colorectal polyps Endoscopic mucosal resection Colorectal surgery

Constructing Hopf Insulator from Geometric Perspective of Hopf Invariant

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Chinese Physics Letters 2024年第3期41卷 121-126页

作者：常治文郝维昌 Miguel bustamante 刘鑫 Institute of Theoretical Physics School of Physics and Optoelectronic EngineeringBeijing University of TechnologyBeijing 100124China School of Physics Beihang UniversityBeijing 100191China Complex and Adaptive Systems Laboratory School of Mathematics and StatisticsUniversity College DublinBelfield4DublinIreland

We propose a method to construct Hopf insulators based on the study of topological defects from the geometric perspective of Hopf invariant ***,we prove two types of topological defects naturally inhering in the inner... 详细信息

关键词： Hopf topological invariant

Gone with the wind： Seasonal trends in foraging movement directions for a central-place forager

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Current Zoology 2014年第5期60卷 604-615页

作者： Jesus HErNANDEZ-PLIEGO Carlos rODrIGUEZ Javier.bustamante Department of Wetland Ecology Estacion Biologica de Dofiana CSIC c/Amorico Vespucio s/n 41092 Seville Spain Department of Conservation Biology Estacion Biologica de Dofiana C SIC c/Amorico Vespucio s/n 41092 Seville Spain

Lesser kestrels Falco naumanni are migratory central-place foragers that breed in dynamic arable landscapes. After arriving from migration, kestrels have no knowledge of the distribution of crops, and consequently prey, around their colony. The energy demand of pairs increases as breeding season progresses, but at the same time prey abundance, and their knowledge on prey distribution, also increases. Wind can have a strong influence on flight cost and kestrels should try to reduce energy expendi- ture when possible. When prey abundance is low, kestrels have little knowledge of prey distribution, and pairs have no chicks, they could reduce foraging flight cost by leaving the colony with tailwinds. When prey is abundant, knowledge on prey distribu- tion has increased, and chick demand is high, kestrels should fly to the most favorable foraging patches. We analyzed foraging trips directions in a lesser kestrel colony along the breeding season and in relation to wind speed and direction. We recorded 664 foraging trips from 19 individuals using GPS-dataloggers. We found that outward flights direction changed from uniform to a concentrated distribution along the season, as prey abundance and individual experience increased. We also found a temporal trend in the angular difference between outward flights and wind directions, with low values early in the season and then increa- sing as expected, but again low values at the end, contrary to expectation. results suggest changes in kestrels foraging strategy along the season in relation to wind. Kestrels depart more with tailwinds in exploratory flights early in the season, while there is a spurious coincidence in direction to preferred foraging patches and dominant wind direction at the end [Current Zoology 60 （5）： 604-615, 2014].

关键词： Falco naumanni Movement ecology Foraging behavior Wind effect GPS-dataloggers

resonance Clustering in Wave Turbulent regimes:Integrable Dynamics

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Communications in Computational Physics 2011年第10期10卷 1211-1240页

作者： Miguel D.bustamante Elena Kartashova School of Mathematical Sciences University College DublinBelfieldDublin 4Ireland IFA J.Kepler UniversityLinz 4040Austria.

Two fundamental facts of the modern wave turbulence theory are 1)existence of power energy spectra in k-space,and 2)existence of“gaps”in this spectra corresponding to the resonance ***,three wave turbulent regimes are singled out:kinetic,described by wave kinetic equations and power energy spectra;discrete,characterized by resonance clustering;and mesoscopic,where both types of wave field time evolution *** this review paper we present the results on integrable dynamics of resonance clusters appearing in discrete and mesoscopic wave turbulent *** a novel method based on the notion of dynamical invariant we show that some of the frequently met clusters are integrable in quadratures for arbitrary initial conditions and some others-only for particular initial *** also identify chaotic behaviour in some *** implications of the results obtained are discussed.

关键词： resonance clustering Hamiltonian formulation wave turbulent regimes Nrdiagram integrable dynamics.

Effect of cerium/lanthanum addition on microstructure and mechanical properties of Al7075 alloy via mechanical alloying and sintering

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Journal of rare Earths 2016年第4期34卷 420-427页

作者： r.Pérez-bustamante A.reyna-Cruz D.C.Acosta-Pena C.r.Santillán-rodríguez J.A.Matutes-Aquino F.Pérez-bustamante M.C.Maldonado-Orozco J.Aguilar-Santillán r.Martínez-Sánchez research Center in Advanced Materials(CIMA V) National Laboratory of NanotechnologyMiguel de Cervantes No.120C.P.31109ChihuahuaChih.Mexico Faculty of Engineering Autonomous University of Chihuahua(UACH)Circuito No.1 Nuevo Campus UniversitarioC.P.31 125ChihuahuaChih.Mexico Faculty of Chemical Sciences Autonomous University of Chihuahua(UACH)Circuito No.1 Nuevo Campus UniversitarioC.P.31125ChihuahuaChih.Mexico Materials&Tools LLC 4118 E Washington CtGilbertAZUSA 85234

The effect of the Al-6Ce-3La（ACL） on the microstructural behavior of the Al7075 was investigated. Materials were synthesized by mechanical alloying with variation in the ACL content and milling time. Products were characterized and studied in the as-milled condition and mechanically evaluated after sintering. The synergetic effect of milling time and ACL content in the modified materials led to a reduction in the particle size. results from electron microscopy showed a homogeneous dispersion of Ce/La phases up to 20 wt.% of ACL content after 10 h of milling. Mechanical evaluation under compressive test showed an improved performance for those alloys reinforced with 0.2 wt.% and 0.5 wt.% of ACL.

关键词： mechanical alloying rare earths aluminum microstructure sintering

Ketamine effect on intracellular and mitochondrial calcium mobilization

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BIOCELL 2016年第1期40卷 11-14页

作者： JUANITA bustamante ANALIA CZErNICZYNIEC SILVIA LOrES-ArNAIZ Centro de Altos Estudios en Ciencias Humanas y de la Salud(CAECIHS) Facultad de MedicinaUniversidad Abierta InteramericanaBuenos AiresArgentina Instituto de Bioquímica y Medicina Molecular Facultad de Farmacia y BioquímicaUniversidad de Buenos AiresArgentina

The suppressive effects of ketamine on intracellular calcium has been reported in a variety of cells although the mechanisms involved are not well *** aim of this work was to evaluate the ketamine effect on the mitochondrial Ca^(2+)accumulation and the cellular Ca^(2+)mobilization using FLUO4-AM and flow *** results showed that mitochondria from ketamine injected animals presented a lower ability to retain calcium at concentrations higher than 20μM,as compared with controls(saline injected animals).In ad-dition,ketamine showed a significant decreased KCl-induced intracellular calcium *** increased calcium influx through cellular *** to the data presented herein,ketamine presents a clear inhibitory effect on cytosolic Ca2+transport mechanisms,independently from their action on the calcium channel associated NMDA receptor.

关键词： calcium transport hippocampal mitochondria Vero cell culture

Effects of temperature and hydric environment on survival of the Panamanian Golden Frog infected with a pathogenic chytrid fungus

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Integrative Zoology 2010年第2期5卷 143-153页

作者： Heidi M.bustamante Lauren J.LIVO Cynthia CArEY Department of Integrative Physiology University of ColoradoBoulderColoradoUSA

Considerable controversy exists concerning whether or not climate changes(particularly global warming)are causing outbreaks of a lethal amphibian pathogen,the chytrid fungus Batrachochytrium dendrobatidis(Longcore,Pessier&*** 1999).In the present study,groups of Panamanian golden frogs(Atelopus zeteki Dunn,1993),a critically endangered amphibian thought to be nearly extinct in Panama,were exposed to varying dosages of zoospores of Batrachochytrium dendrobatidis,temperatures and hydric environments in order to learn whether this species is susceptible to this pathogen and,if so,how environmental factors affect *** pathogen proved to be highly lethal for *** exposed to a dosage of 100 Bd zoospores survived significantly(Pr than those that had been exposed to 104 or 106 *** frogs housed at 23℃survived significantly(Pr than those that were housed at 17℃.Exposed frogs held in dry conditions survived significantly longer than those in wet conditions(Pratory study,these results do not directly test hypotheses about the relation between climate change and the decline of these frogs in the field,but they inform the discussion about how environmental conditions can have an impact on the interaction between a susceptible amphibian and this *** data do not support the contention that rising global temperatures are necessary to cause the death of amphibians infected with this pathogen because the pathogen was equally lethal at 17 as at 23℃,and frogs at the warmer temperature lived significantly longer than those at the cooler one.

关键词： amphibian declines Atelopus zeteki Batrachochytrium dendrobatidis chytridiomycosis climatelinked-epidemic hypothesis