853 research outputs found

    Stress and strain analysis and induced seismicity in geological gas storage (Yela, Spain)

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    Geologic gas storage is a sustainable strategy to store energy in underground reservoirs in order to be used under demand. Injection and withdrawal gas operations could trigger induced seismicity according to the tectonic constrains of the reservoir. The study of the active stress/strain fields shows the properties of the fault patterns that can be involved in induced seismicity. In our work, we have determined the strain/stress field in the Yela underground gas storage, an Upper Cretaceous carbonate reservoir located in central Spain. Slickensides on fault planes were measured from Cretaceous, Miocene and Quaternary rocks. Results show a strain field with ey (maximum horizontal shortening) oriented NW-SE. This field was compressional during the early Miocene, switching off to extensional from late Miocene to present-day. Our results suggest that NNW-SSE and NW-SE oriented faults could act as an effective pathway for gas leakage and prone to trigger induced seismicity. Moreover, 141 small earthquakes (Mmax 2.3) were recorded during underground operations in Yela. Peaks of earthquakes appear seasonally from November to February, in coincidence with the injection operations prior to the winter withdrawal. Working at its maximum gas storage volume, earthquake peaks decreased in intensity and magnitude from 2017 to 2021, and show a time lag of 3 months from the month of maximum volume injection to the earthquake occurrenc

    CaracterĂ­sticas das ondas de desenvolvimento folicular em novilhas Bos taurus indicus prĂŠ-pĂşberes de dois tamanhos diferentes

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    The purpose of this study was to evaluate in a period of 42 days prior to the onset of puberty (PB), the effects of size (small size and large size) of prepubertal Brahman heifers (BHM) on; age, characteristics of follicular dynamics, and body composition parameters. In addition, the frame score (body structure) was calculated as an additional estimator of height. We defined PB as the first ovulation preceded by the observation of estrus and followed by the formation of a corpus luteum (CL) of normal duration. Prepubertal BHM (10) heifers were used. The feeding was individual with corn silage and commercial concentrate to obtain similar weight gains. Measurements of weight and body condition score (BCS) were performed every 14 d. Ovulation and the formation of the CL were confirmed according to the monitoring of the ovarian structures by ultrasonography. Statistically, correlation analysis and analysis of variance were performed with the GLM procedure of SAS. A significant effect of size on the total number of follicles at PB was found, where small-sized heifers had 16 follicles, while those of large size had 12 follicles at PB (P < 0.0001). The frame score of the undersized animals was 10 % higher than that of the oversized heifers (P < 0.0001). Likewise, the frame score had a significant effect (P < 0.0001) on the total number of follicles in the PB. In conclusion, the effect of height in prepubertal animals is a complex characteristic, associated with body composition parameters, which affects some of the characteristics of follicular dynamics, and is worth further study in Zebu cattle.En un periodo de 42 días previos al inicio de la pubertad (PB), se estudiaron los efectos de la talla (talla chica y talla grande) de vaquillas prepúberes de la raza Brahman (BHM) sobre; la edad, características de la dinåmica folicular y paråmetros de composición corporal. Ademås, se calculó el frame score (estructura corporal) como estimador adicional de la talla. La PB fue definida como la primera ovulación precedida por la observación del estro y seguida por la formación de un cuerpo lúteo de duración normal. Se utilizaron 10 vaquillas BHM. La alimentación fue individual con ensilado de maíz y concentrado comercial para obtención de ganancias de peso similares. Se realizaron pesajes y se midió la condición corporal (CC) cada 14 d. De acuerdo al monitoreo ultrasonogråfico de las estructuras ovåricas se confirmó la ovulación y la formación del cuerpo lúteo (CL). Estadísticamente se realizó un anålisis de correlación y anålisis de varianza con el procedimiento GLM del SAS. Se encontró efecto significativo de la talla sobre el número total de folículos a la PB, en donde las vaquillas de talla chica registraron 16 folículos, mientras que las de talla grande tuvieron 12 folículos a la PB (P < 0.0001). El frame score de los animales de talla chica fue 10 % mayor que la de las vaquillas de talla grande (P < 0.0001). Así mismo, se observó que el frame score tuvo un efecto significativo (P < 0.0001) sobre el número total de folículos a la PB. Se concluye que el efecto de la talla en animales prepúberes una característica compleja, que estå asociada con los paråmetros de composición corporal y que afecta algunas de las características de la dinåmica folicular y que ademås vale la pena seguir estudiando en el ganado Cebú.Em um período de 42 dias antes do início da puberdade (PB), os efeitos do tamanho (pequeno e grande porte) de novilhas Brahman prÊ-púberes (BHM) sobre; idade, características da dinâmica folicular e parâmetros de composição corporal. AlÊm disso, a pontuação do quadro (estrutura corporal) foi calculada como um estimador adicional de altura. BP foi definido como a primeira ovulação precedida pela observação do estro e seguida pela formação de um corpo lúteo de duração normal. Foram utilizadas 10 novilhas BHM. A alimentação foi individual com silagem de milho e concentrado comercial para obtenção de ganhos de peso semelhantes. Pesagens foram realizadas e a condição corporal (CC) foi medida a cada 14 dias. De acordo com o acompanhamento ultrassonogråfico das estruturas ovarianas, foi confirmada a ovulação e a formação do corpo lúteo (CL). Estatisticamente, uma anålise de correlação e anålise de variância foram realizadas com o procedimento GLM do SAS. Um efeito significativo do tamanho sobre o número total de folículos no BP foi encontrado, onde novilhas de pequeno porte tiveram 16 folículos, enquanto as de grande porte tiveram 12 folículos no BP (P < 0,0001). O escore estrutural dos animais subdimensionados foi 10% maior do que o das novilhas superdimensionadas (P < 0,0001). Da mesma forma, observou-se que o frame score teve efeito significativo (P < 0,0001) sobre o número total de folículos no PB. Conclui-se que o efeito da altura em animais prÊ-púberes Ê uma característica complexa, que estå associada a parâmetros de composição corporal e que afeta algumas das características da dinâmica folicular, e que tambÊm merece um estudo mais aprofundado em zebuínos

    Endurecimiento por precipitaciĂłn en aleaciones al-4%cu-0.5%mg modificadas con ag

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    El estudio del endurecimiento por precipitación en la aleación Al-4%Cu- 0.5%Mg con adiciones de 0.5-4%Ag se realizó mediante microscopía electrónica de transmisión (MET) y microdureza Vickers. Las aleaciones fueron homogeneizadas a 525°C durante 7 días y templadas. Los tratamientos de precipitación se realizaron a 150, 200 y 250°C por diferentes tiempos. La adición de hasta 3%Ag promueve un aumento en dureza para todos los tratamientos de envejecido. Adicionalmente, los resultados muestran que la coexistencia de las fases θ’ y Ω son las responsables de promover el aumento en dureza. Por otra parte, los análisis de MET confirman que la fase Ω tiene una estructura fcc, es coherente con la matriz, y su morfología es hexagonal con intercaras alineadas en las direcciones [311]α, [022]α y [111]α. Finalmente, la disminución en la dureza de las aleaciones se atribuye a la desaparición de la fase θ’ y al engrosamiento de la fase Ω

    Home Garden as Socio-Environmental Sustainability Option

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    El artículo tiene como objetivo analizar la estrategia “huertas caseras” como opción de sostenibilidad socio-ambiental, tomando como referente contextual la expe-riencia de acciones solidarias de seguridad alimentaria con familias del Municipio de Tenza (Boyacá, Colombia). La metodología se aborda desde tres fases: 1) Diagnós-tica, orientada al reconocimiento de la comunidad inter-venida, a través de una ficha de caracterización socio­demográfica, ambiental y de seguridad alimentaria; 2) Diseño de un plan estratégico con acciones solidarias para la atención de las necesidades encontradas en el diagnóstico. 3) Implementación del plan propuesto en las comunidades objeto de estudio. Los resultados evidencian como el modelo de huerta casera y el aprovechamiento de residuos sólidos orgánicos, resultan opciones estratégicas pertinentes para generar en la comunidad una iniciativa de reflexión sobre la seguridad alimentaria y la sosteni-bilidad socioambiental. Se concluye de esta forma como al contar con una mejor oferta alimenticia para la población, se podrá garantizar una óptima ingesta de nutrientes, mejorando los niveles de bienestar y estado de salud en sus habitantesThe objective of this article is to analyze the "home gardens" strategy as an option for socio-environmental sustainability, taking as a contextual reference the ex-perience of food security solidarity actions with fami-lies in the Municipality of Tenza (Boyacá, Colombia). The methodology is approached from three phases: 1) Diagnosis, oriented to the recognition of the intervened community, through a sociodemographic, environmen-tal and food security characterization file; 2) Design of a strategic plan with solidary actions for the attention of the needs found in the diagnosis. 3) Implementation of the proposed plan in the communities under study. The results show how the home-garden model and the use of solid organic waste are relevant strategic op-tions to generate in the community an initiative for reflection on food security and socio­environmental sustainability. It is concluded in this way that by hav-ing a better food supply for the population, it will be possible to guarantee an optimal intake of nutrients, improving the levels of welfare and health status of its inhabitants

    AnĂĄlisis arqueosismolĂłgico del conjunto arqueolĂłgico romano de Mulva- Munigua (Sevilla, EspaĂąa). Resultados preliminares

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    El conjunto arqueolĂłgico romano de Mulva-Munigua (Sevilla, EspaĂąa) presenta daĂąos en las edificaciones que pueden ser interpretadas como resultado de la ocurrencia de un evento sĂ­smico (Efectos ArqueolĂłgicos de los Terremotos: EAEs) a finales del siglo III A.D., fecha coincidente con el inicio del periodo de declive econĂłmico de este asentamiento romano. Para intentar establecer el posible origen sĂ­smico de las deformaciones, se ha procedido al inventario y anĂĄlisis de las estructuras deformadas presentes en el yacimiento. No obstante, algunas de estas deformaciones tambiĂŠn se pueden interpretar como resultado de procesos gravitaciones asociados a la ladera Este de la colina sobre la que se sitĂşa parte del yacimiento. Las direcciones de mĂĄxima deformaciĂłn (ey) obtenidas del anĂĄlisis de EAEs indica dos direcciones preferentes de la deformaciĂłn (o movimiento preferente del terreno): NNO-SSE y ENEOSO. Aunque los datos presentan una dispersiĂłn importante, se puede establecer que la orientaciĂłn principal NNO-SSE es compatible con un evento sĂ­smico situado en el borde norte del Valle del Guadalquivir. La orientaciĂłn ENE-OSO podrĂ­a relacionarse con un evento posterior, o mĂĄs seguramente con procesos de ladera de carĂĄcter cosĂ­smico o no.The Roman archaeological site of Mulva-Munigua (Sevilla, Spain) displays building damage features suggesting a seismic origin (Earthquake Archaeological Effects: EAEs). The proposed seismic event could be tentatively dated in the late 3rd century AD, coinciding with the beginning of the economic fall of the Roman Empire at Iberia. However, some of the recorded EAEs can be also interpreted as a result of intervening slope movements in the eastern hillslope of this roman site. The inventory and analysis of the proposed EAEs make possible to discern between seismic oriented damage and other causes. In spite of the data show a significant dispersion, their analysis result in two different orientations of maximum deformation (ey) or preferential ground movement: NNW-SSE and ENE-WSW. The main ey orientation (NNW-SSE) can be tentatively related to a seismic event occurred in the environs of the northern border of the Guadalquivir Depression. The secondary orientation (ENE-WSW) can be interpreted as a consequence of latter slope movements triggered (or not) by other ancient earthquakes

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV

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    The azimuthal anisotropy of charged particles in PbPb collisions at nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pt) range up to approximately 60 GeV. The data cover both the low-pt region associated with hydrodynamic flow phenomena and the high-pt region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with pt, reaching a maximum around pt = 3 GeV, and then to gradually decrease to almost zero, with the decline persisting up to at least pt = 40 GeV over the full centrality range measured.Comment: Replaced with published version. Added journal reference and DO

    Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

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    Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

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    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE
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