Let A be the class of functions f(z)=z+sum from n=2 to ∞ (a_nZ^n) which are analytic in the unit disc, and let In this paper, Some properties of Q_α(β) and R_α(β) are investigated. In particular, Some results due...Let A be the class of functions f(z)=z+sum from n=2 to ∞ (a_nZ^n) which are analytic in the unit disc, and let In this paper, Some properties of Q_α(β) and R_α(β) are investigated. In particular, Some results due to chichra [4], Mocanu[5] and Obradovic[6] are extended. In addition, We also showed an error of S. Owa[8].展开更多
Sand production is an undesired phenomenon occurring in unconsolidated formations due to shear failure and hydrodynamic forces. There have been many approaches developed to predict sand production and prevent it by ch...Sand production is an undesired phenomenon occurring in unconsolidated formations due to shear failure and hydrodynamic forces. There have been many approaches developed to predict sand production and prevent it by changing drilling or production strategies. However, assumptions involved in these approaches have limited their applications to very specific scenarios. In this paper, an elliptical model based on the borehole shape is presented to predict the volume of sand produced during the drilling and depletion stages of oil and gas reservoirs. A shape factor parameter is introduced to estimate the changes in the geometry of the borehole as a result of shear failure. A carbonate reservoir from the south of Iran with a solid production history is used to show the application of the developed methodology. Deriving mathematical equations for determination of the shape factor based on different failure criteria indicate that the effect of the intermediate principal stress should be taken into account to achieve an accurate result. However, it should be noticed that the methodology presented can only be used when geomechanical parameters are accurately estimated prior to the production stage when using wells and field data.展开更多
DNA translesion synthesis(TLS)is a DNA damage tolerance mechanism that relies on a series of specialized DNA polymerases able to bypass a lesion on a DNA template strand during replication or post-repair synthesis.TLS...DNA translesion synthesis(TLS)is a DNA damage tolerance mechanism that relies on a series of specialized DNA polymerases able to bypass a lesion on a DNA template strand during replication or post-repair synthesis.TLS DNA polymerases pursue replication by inserting a base opposite this lesion,correctly or incorrectly展开更多
Herbal medicines have been used since ancient times for thetreatment of many diseases and illnesses.Modern chromatographic and spectroscopic techniques have had a tremendous impact on the analysis of herbal medicine t...Herbal medicines have been used since ancient times for thetreatment of many diseases and illnesses.Modern chromatographic and spectroscopic techniques have had a tremendous impact on the analysis of herbal medicine to facilitate research as well as enhancement of safety and efficacy of commercial products.Today,with the展开更多
文摘Let A be the class of functions f(z)=z+sum from n=2 to ∞ (a_nZ^n) which are analytic in the unit disc, and let In this paper, Some properties of Q_α(β) and R_α(β) are investigated. In particular, Some results due to chichra [4], Mocanu[5] and Obradovic[6] are extended. In addition, We also showed an error of S. Owa[8].
文摘Sand production is an undesired phenomenon occurring in unconsolidated formations due to shear failure and hydrodynamic forces. There have been many approaches developed to predict sand production and prevent it by changing drilling or production strategies. However, assumptions involved in these approaches have limited their applications to very specific scenarios. In this paper, an elliptical model based on the borehole shape is presented to predict the volume of sand produced during the drilling and depletion stages of oil and gas reservoirs. A shape factor parameter is introduced to estimate the changes in the geometry of the borehole as a result of shear failure. A carbonate reservoir from the south of Iran with a solid production history is used to show the application of the developed methodology. Deriving mathematical equations for determination of the shape factor based on different failure criteria indicate that the effect of the intermediate principal stress should be taken into account to achieve an accurate result. However, it should be noticed that the methodology presented can only be used when geomechanical parameters are accurately estimated prior to the production stage when using wells and field data.
文摘DNA translesion synthesis(TLS)is a DNA damage tolerance mechanism that relies on a series of specialized DNA polymerases able to bypass a lesion on a DNA template strand during replication or post-repair synthesis.TLS DNA polymerases pursue replication by inserting a base opposite this lesion,correctly or incorrectly
文摘Herbal medicines have been used since ancient times for thetreatment of many diseases and illnesses.Modern chromatographic and spectroscopic techniques have had a tremendous impact on the analysis of herbal medicine to facilitate research as well as enhancement of safety and efficacy of commercial products.Today,with the
