Connecting earthquake nucleation in basement rock to fluid injection in basal,sedimentary reservoirs,depends heavily on choices related to the poroelastic properties of the fluid-rock system,thermo-chemical effects no...Connecting earthquake nucleation in basement rock to fluid injection in basal,sedimentary reservoirs,depends heavily on choices related to the poroelastic properties of the fluid-rock system,thermo-chemical effects notwithstanding.Direct constraints on these parameters outside of laboratory settings are rare,and it is commonly assumed that the rock layers are isotropic.With the Arbuckle wastewater disposal reservoir in Osage County,Oklahoma,high-frequency formation pressure changes and collocated broadband ground velocities measured during the passing of large teleseismic waves show a poroelastic response of the reservoir that is both azimuthally variable and anisotropic;this includes evidence of static shifts in pressure that presumably relate to changes in local permeability.The azimuthal dependence in both the static response and shear coupling appears related to tectonic stress and strain indicators such as the orientations of the maximum horizontal stress and faults and fractures.Using dynamic strains from a nearby borehole strainmeter,we show that the ratio of shear to volumetric strain coupling is~0.41 which implies a mean Skempton's coefficient of A=0.24 over the plausible range of the undrained Poisson's ratio.Since these observations are made at relatively low confining pressure and differential stress,we suggest that the hydraulically conductive fracture network is a primary control on the coupling between pore pressure diffusion and elastic stresses in response to natural or anthropogenic sources.展开更多
From 2009 to 2017,parts of Central America experienced marked increase in the number of small to moderate-sized earthquakes.For example,three significant earthquakes(~Mw 5)occurred near Prague,Oklahoma,in the U.S.in 2...From 2009 to 2017,parts of Central America experienced marked increase in the number of small to moderate-sized earthquakes.For example,three significant earthquakes(~Mw 5)occurred near Prague,Oklahoma,in the U.S.in 2011.On 6 Nov 2011,an Mw 5.7 earthquake occurred in Prague,central Oklahoma with a sequence of aftershocks.The seismic activity has been attributed to slip on the Wilzetta fault system.This study provides a 3 D fully coupled poroelastic analysis(using FLAC3 D)of the Wilzetta fault system and its response to saltwater injection in the underpressured subsurface layers,especially the Arbuckle group and the basement,to evaluate the conditions that might have led to the increased seismicity.Given the data-limited nature of the problem,we have considered multiple plausible scenarios,and use the available data to evaluate the hydromechanical response of the faults of interest in the study area.Numerical simulations show that the injection of large volumes of fluid into the Arbuckle group tends to bring the part of the Wilzetta faults in Arbuckle group and basement into near-critical conditions.展开更多
2011年11月6日3时,美国俄克拉何马州发生了5.6级地震。此次地震是该地区100多年以来的最大地震,因该区地震活动性低,故需要对此次地震成因开展研究。本文采用CAP(Cut And Paste)方法对该地震分别进行近震、远震以及近远震联合反演,得到...2011年11月6日3时,美国俄克拉何马州发生了5.6级地震。此次地震是该地区100多年以来的最大地震,因该区地震活动性低,故需要对此次地震成因开展研究。本文采用CAP(Cut And Paste)方法对该地震分别进行近震、远震以及近远震联合反演,得到了震源机制解与震源深度。其中联合反演得到的机制解参数为:节面Ⅰ:234°/81°/-170°;节面Ⅱ:143°/81°/-9°;震级为MW=5.6。为了验证近震结果的可靠性,采用不同模型对近震数据进行反演测试,发现震源断层面解结果有3°的偏差,震源深度结果有0.5km偏差。CAP结果显示,该地震的质心深度为5.0km左右,属于浅源地震。同时,根据地震震源参数的标度分析,得到破裂区宽度约为7.0km,此次地震破裂区上缘可达1.4km深,下缘深度达8.4km。破裂上缘在该区域井的注水深度范围之内,由此推测该地震可能与当地页岩气开采过程中的注水活动有关。展开更多
Overhead electrical power distribution systems(PDS)are very susceptible to extreme wind hazards.Power outages can cause catastrophic consequences,including economic losses,loss of critical services,and disruption to d...Overhead electrical power distribution systems(PDS)are very susceptible to extreme wind hazards.Power outages can cause catastrophic consequences,including economic losses,loss of critical services,and disruption to daily life.Therefore,it is very important to model the resilience of PDS against extreme winds to support disaster planning.While several frameworks currently exist to assess the resilience of PDS subjected to extreme winds,these frameworks do not systematically consider the tree-failure risk.In other words,there is no integrated framework that can simultaneously consider tree failures,PDS component failures induced by falling trees,resilience assessment,and evaluation of resilience enhancement with vegetation management.Therefore,this study proposed an integrated simulation framework to model the resilience of PDS against extreme winds,which includes tree fragility modeling,PDS fragility modeling,PDS component failure estimation,system performance evaluation,system restoration modeling,and resilience enhancement evaluation.The framework is demonstrated with a power distribution network in Oklahoma.The results show that the estimated system resilience will reduce if tree failures are considered.Crown thinning can effectively enhance the system’s resilience,but the effectiveness is affected by both wind speed and direction.展开更多
The poor prognosis of glioblastoma multiforme(GBM)patients is in part due to resistance to current standard-of-care treatments including chemotherapy[predominantly temozolomide(TMZ;Temodar)],radiation therapy and an a...The poor prognosis of glioblastoma multiforme(GBM)patients is in part due to resistance to current standard-of-care treatments including chemotherapy[predominantly temozolomide(TMZ;Temodar)],radiation therapy and an anti-angiogenic therapy[an antibody against the vascular endothelial growth factor(bevacizumab;Avastin)],resulting in recurrent tumors.Several recurrent GBM tumors are commonly resistant to either TMZ,radiation or bevacizumab,which contributes to the low survival rate for GBM patients.This review will focus on novel targets and therapeutic approaches that are currently being considered to combat GBM chemoresistance.One of these therapeutic options is a small molecule called OKlahoma Nitrone 007(OKN-007),which was discovered to inhibit the transforming growth factor β1 pathway,reduce TMZ-resistance and enhance TMZ-sensitivity.OKN-007 is currently an investigational new drug in clinical trials for both newly-diagnosed and recurrent GBM patients.Another novel target is ELTD1(epidermal growth factor,latrophilin and seven transmembrane domain-containing protein 1;alternatively known as ADGRL4,Adhesion G protein-coupled receptor L4),which we used a monoclonal antibody against,where a therapy against it was found to inhibit Notch 1 in a pre-clinical GBM xenograft model.Notch 1 is known to be associated with chemoresistance in GBM.Other potential therapeutic targets to combat GBM chemoresistance include the phosphoinositide 3-kinase pathway,nuclear factor-κB,the hepatocyte/scatter factor(c-MET),the epidermal growth factor receptor,and the tumor microenvironment.展开更多
文摘Connecting earthquake nucleation in basement rock to fluid injection in basal,sedimentary reservoirs,depends heavily on choices related to the poroelastic properties of the fluid-rock system,thermo-chemical effects notwithstanding.Direct constraints on these parameters outside of laboratory settings are rare,and it is commonly assumed that the rock layers are isotropic.With the Arbuckle wastewater disposal reservoir in Osage County,Oklahoma,high-frequency formation pressure changes and collocated broadband ground velocities measured during the passing of large teleseismic waves show a poroelastic response of the reservoir that is both azimuthally variable and anisotropic;this includes evidence of static shifts in pressure that presumably relate to changes in local permeability.The azimuthal dependence in both the static response and shear coupling appears related to tectonic stress and strain indicators such as the orientations of the maximum horizontal stress and faults and fractures.Using dynamic strains from a nearby borehole strainmeter,we show that the ratio of shear to volumetric strain coupling is~0.41 which implies a mean Skempton's coefficient of A=0.24 over the plausible range of the undrained Poisson's ratio.Since these observations are made at relatively low confining pressure and differential stress,we suggest that the hydraulically conductive fracture network is a primary control on the coupling between pore pressure diffusion and elastic stresses in response to natural or anthropogenic sources.
文摘From 2009 to 2017,parts of Central America experienced marked increase in the number of small to moderate-sized earthquakes.For example,three significant earthquakes(~Mw 5)occurred near Prague,Oklahoma,in the U.S.in 2011.On 6 Nov 2011,an Mw 5.7 earthquake occurred in Prague,central Oklahoma with a sequence of aftershocks.The seismic activity has been attributed to slip on the Wilzetta fault system.This study provides a 3 D fully coupled poroelastic analysis(using FLAC3 D)of the Wilzetta fault system and its response to saltwater injection in the underpressured subsurface layers,especially the Arbuckle group and the basement,to evaluate the conditions that might have led to the increased seismicity.Given the data-limited nature of the problem,we have considered multiple plausible scenarios,and use the available data to evaluate the hydromechanical response of the faults of interest in the study area.Numerical simulations show that the injection of large volumes of fluid into the Arbuckle group tends to bring the part of the Wilzetta faults in Arbuckle group and basement into near-critical conditions.
文摘2011年11月6日3时,美国俄克拉何马州发生了5.6级地震。此次地震是该地区100多年以来的最大地震,因该区地震活动性低,故需要对此次地震成因开展研究。本文采用CAP(Cut And Paste)方法对该地震分别进行近震、远震以及近远震联合反演,得到了震源机制解与震源深度。其中联合反演得到的机制解参数为:节面Ⅰ:234°/81°/-170°;节面Ⅱ:143°/81°/-9°;震级为MW=5.6。为了验证近震结果的可靠性,采用不同模型对近震数据进行反演测试,发现震源断层面解结果有3°的偏差,震源深度结果有0.5km偏差。CAP结果显示,该地震的质心深度为5.0km左右,属于浅源地震。同时,根据地震震源参数的标度分析,得到破裂区宽度约为7.0km,此次地震破裂区上缘可达1.4km深,下缘深度达8.4km。破裂上缘在该区域井的注水深度范围之内,由此推测该地震可能与当地页岩气开采过程中的注水活动有关。
基金supported by the National Science Foundation under Grant No.OIA-1946093。
文摘Overhead electrical power distribution systems(PDS)are very susceptible to extreme wind hazards.Power outages can cause catastrophic consequences,including economic losses,loss of critical services,and disruption to daily life.Therefore,it is very important to model the resilience of PDS against extreme winds to support disaster planning.While several frameworks currently exist to assess the resilience of PDS subjected to extreme winds,these frameworks do not systematically consider the tree-failure risk.In other words,there is no integrated framework that can simultaneously consider tree failures,PDS component failures induced by falling trees,resilience assessment,and evaluation of resilience enhancement with vegetation management.Therefore,this study proposed an integrated simulation framework to model the resilience of PDS against extreme winds,which includes tree fragility modeling,PDS fragility modeling,PDS component failure estimation,system performance evaluation,system restoration modeling,and resilience enhancement evaluation.The framework is demonstrated with a power distribution network in Oklahoma.The results show that the estimated system resilience will reduce if tree failures are considered.Crown thinning can effectively enhance the system’s resilience,but the effectiveness is affected by both wind speed and direction.
基金This work was supported by the Oklahoma Medical Research Foundation,and Oblato,Inc.,as reported in published manuscripts.
文摘The poor prognosis of glioblastoma multiforme(GBM)patients is in part due to resistance to current standard-of-care treatments including chemotherapy[predominantly temozolomide(TMZ;Temodar)],radiation therapy and an anti-angiogenic therapy[an antibody against the vascular endothelial growth factor(bevacizumab;Avastin)],resulting in recurrent tumors.Several recurrent GBM tumors are commonly resistant to either TMZ,radiation or bevacizumab,which contributes to the low survival rate for GBM patients.This review will focus on novel targets and therapeutic approaches that are currently being considered to combat GBM chemoresistance.One of these therapeutic options is a small molecule called OKlahoma Nitrone 007(OKN-007),which was discovered to inhibit the transforming growth factor β1 pathway,reduce TMZ-resistance and enhance TMZ-sensitivity.OKN-007 is currently an investigational new drug in clinical trials for both newly-diagnosed and recurrent GBM patients.Another novel target is ELTD1(epidermal growth factor,latrophilin and seven transmembrane domain-containing protein 1;alternatively known as ADGRL4,Adhesion G protein-coupled receptor L4),which we used a monoclonal antibody against,where a therapy against it was found to inhibit Notch 1 in a pre-clinical GBM xenograft model.Notch 1 is known to be associated with chemoresistance in GBM.Other potential therapeutic targets to combat GBM chemoresistance include the phosphoinositide 3-kinase pathway,nuclear factor-κB,the hepatocyte/scatter factor(c-MET),the epidermal growth factor receptor,and the tumor microenvironment.
