Hydro-mechanical modeling of two-phase fluid flow in deforming, partially saturated porous media with propagating cohesive cracks using the extended finite element method

In the present paper, a fully coupled numerical model is developed for the hydromechanical analysis of deforming, progressively fracturing porous media interacting with the flow of two immiscible, compressible wetting and non-wetting pore fluids. The governing equations involving the coupled two-phase fluid flow and deformation processes in partially saturated porous media containing cohesive cracks are derived within the framework of the generalized Biot theory. The displacement of the solid phase, the pressure of the wetting phase and the capillary pressure are taken as the primary unknowns of the three-phase formulation. A softening cohesive law is employed to describe the nonlinear behavior of the material in the fracture process zone. In order to account for the flux of the two fluid phases through the fracture faces, the mass balance equation for each flowing fluid inside the fully damaged zone and the cohesive zone is averaged over its cross section. The resulting equations provide mass couplings to the standard equations of the multiphase system. The effect of cracking and therefore change of porosity on the permeability of the damaged zone is also taken into account. To arrive at the discrete equations, the extended finite element method (XFEM) is utilized to discretize the weak form of the balance equations of mass and linear momentum in spatial domain along with the Generalized Newmark scheme for time domain discretization. By exploiting the partition of unity property of finite element shape functions, the evolving cohesive crack is simulated independently of the underlying finite element mesh and without continuous remeshing of the domain as the crack grows by adding enriched degrees of freedom to nodes whose support is bisected by the crack. For the numerical solution, the unconditionally stable direct time-stepping procedure is applied to solve the resulting system of strongly coupled non-linear algebraic equations using a Newton-Raphson iterative procedure. Finally, numerical simulations are presented to demonstrate the capability of the proposed method and the significant influence of the hydro-mechanical coupling between the continuum porous medium and the discontinuity on the results

Order Processing in Supply Chain Management with Developing an Information System Model An Automotive Manufacturing Case Study

Nowadays, high competitive market needs fast, effective, high responsiveness, online interactive, 24 hours 7 days availability and easy to follow up order processing. Consequently, there is a need for a model in which interdisciplinary approaches for understanding the range of Supply Chain Management (SCM) Information System (IS) capabilities are provided. In this study, an integrated model of SCM IS was developed that is supported by empirical evidence specific to SCM IS implementations. The developed model integrates and enriches theories of competitive strategy, supply chain management and inter-organizational information systems. Then, a case study of an automotive manufacturing industry was conducted to demonstrate the proficiency of the proposed model. As a result, better understanding of capabilities of implemented supply chain management information systems and expected future capabilities could be identified by practitioners and decision makers. Finally, findings of this study are listed together with some future works

Order Processing in Supply Chain Management with Developing an Information System Model An Automotive Manufacturing Case Study

Nowadays, high competitive market needs fast, effective, high responsiveness, online interactive, 24 hours 7 days availability and easy to follow up order processing. Consequently, there is a need for a model in which interdisciplinary approaches for understanding the range of Supply Chain Management (SCM) Information System (IS) capabilities are provided. In this study, an integrated model of SCM IS was developed that is supported by empirical evidence specific to SCM IS implementations. The developed model integrates and enriches theories of competitive strategy, supply chain management and inter-organizational information systems. Then, a case study of an automotive manufacturing industry was conducted to demonstrate the proficiency of the proposed model. As a result, better understanding of capabilities of implemented supply chain management information systems and expected future capabilities could be identified by practitioners and decision makers. Finally, findings of this study are listed together with some future works

Hydro-mechanical modeling of two-phase fluid flow in deforming, partially saturated porous media with propagating cohesive cracks using the extended finite element method

In the present paper, a fully coupled numerical model is developed for the hydromechanical analysis of deforming, progressively fracturing porous media interacting with the flow of two immiscible, compressible wetting and non-wetting pore fluids. The governing equations involving the coupled two-phase fluid flow and deformation processes in partially saturated porous media containing cohesive cracks are derived within the framework of the generalized Biot theory. The displacement of the solid phase, the pressure of the wetting phase and the capillary pressure are taken as the primary unknowns of the three-phase formulation. A softening cohesive law is employed to describe the nonlinear behavior of the material in the fracture process zone. In order to account for the flux of the two fluid phases through the fracture faces, the mass balance equation for each flowing fluid inside the fully damaged zone and the cohesive zone is averaged over its cross section. The resulting equations provide mass couplings to the standard equations of the multiphase system. The effect of cracking and therefore change of porosity on the permeability of the damaged zone is also taken into account. To arrive at the discrete equations, the extended finite element method (XFEM) is utilized to discretize the weak form of the balance equations of mass and linear momentum in spatial domain along with the Generalized Newmark scheme for time domain discretization. By exploiting the partition of unity property of finite element shape functions, the evolving cohesive crack is simulated independently of the underlying finite element mesh and without continuous remeshing of the domain as the crack grows by adding enriched degrees of freedom to nodes whose support is bisected by the crack. For the numerical solution, the unconditionally stable direct time-stepping procedure is applied to solve the resulting system of strongly coupled non-linear algebraic equations using a Newton-Raphson iterative procedure. Finally, numerical simulations are presented to demonstrate the capability of the proposed method and the significant influence of the hydro-mechanical coupling between the continuum porous medium and the discontinuity on the results

Assessment of Design and Retrofitting Solutions on the Progressive Collapse of Hongqi Bridge

In 2009, the Hongqi Bridge, a multispan reinforced concrete bridge located in Zhuzhou, Hunan Province, China, collapsed progressively in the form of domino, due to extreme effect of deck to pier, during demolition process of the bridge. In this study, progressive collapse of Hongqi Bridge was investigated using nonlinear dynamic analysis in the Applied Element Method, which has been proven as one of the best methods that can follow the collapse behavior of structures. Good agreements were obtained between numerical results and field observations as well as previously reported results. After verifying the bridge collapse procedure, the effects of different alternatives for superstructure and substructure systems on the progressive collapse procedure were investigated. In addition, application of restrainers at the connection of deck to abutment was studied as an effective solution in order to prevent collapse propagation and to minimize associated damages. The results of the study showed that all chosen methods and factors could be helpful and effective in the procedure of collapse propagation for this kind of bridge

Order Processing in Supply Chain Management with Developing an Information System Model An Automotive Manufacturing Case Study

Nowadays, high competitive market needs fast, effective, high responsiveness, online interactive, 24 hours 7 days availability and easy to follow up order processing. Consequently, there is a need for a model in which interdisciplinary approaches for understanding the range of Supply Chain Management (SCM) Information System (IS) capabilities are provided. In this study, an integrated model of SCM IS was developed that is supported by empirical evidence specific to SCM IS implementations. The developed model integrates and enriches theories of competitive strategy, supply chain management and inter-organizational information systems. Then, a case study of an automotive manufacturing industry was conducted to demonstrate the proficiency of the proposed model. As a result, better understanding of capabilities of implemented supply chain management information systems and expected future capabilities could be identified by practitioners and decision makers. Finally, findings of this study are listed together with some future works

Protective effects of hydroalcoholic extract of Stachys pilifera on paracetamol-induced nephrotoxicity in female rats

Background and purpose: Stachys pilifera is used in traditional medicine due to its antioxidant, anti-inflammatory, and antimicrobial effects. The goal of this study was to examine the renoprotective activity of the hydroalcoholic extract of aerial parts of S. pilifera on paracetamol (PCM)-induced nephrotoxicity. Experimental approach: The Wistar female rats were randomly divided into four groups including control, PCM, S. pilifera hydroalcoholic extract (SPE), and PCM + SPE. The animals received SPE (500 mg/kg) for one week and PCM (3 g/kg) on the 6th day orally. Kidney function tests and oxidant/antioxidant markers were determined in serum and tissue homogenate, respectively. Protein and mRNA levels of TNF-alpha, as well as hematoxylin and eosin staining, were assessed in the kidney tissue. Findings/Results: Treatment with SPE in the PCM group significantly decreased blood urea nitrogen and creatinine against the merely PCM rats (P < 0.05). The amount of nitric oxide metabolite and superoxide dismutase activity in the group receiving SPE showed a significant increase compared to PCM rats (P < 0.05). A significant difference in TNF-alpha levels between the groups was not observed. Histological changes were improved in the rats treated with SPE. Conclusion and implications: Totally, our findings showed that SPE can inhibit PCM nephrotoxicity by enhancing kidney function markers, antioxidant status, and histological changes. Though, more researches are required to estimate the possible mechanism of SPE. </p

Order Processing in Supply Chain Management with Developing an Information System Model An Automotive Manufacturing Case Study

Nowadays, high competitive market needs fast, effective, high responsiveness, online interactive, 24 hours 7 days availability and easy to follow up order processing. Consequently, there is a need for a model in which interdisciplinary approaches for understanding the range of Supply Chain Management (SCM) Information System (IS) capabilities are provided. In this study, an integrated model of SCM IS was developed that is supported by empirical evidence specific to SCM IS implementations. The developed model integrates and enriches theories of competitive strategy, supply chain management and inter-organizational information systems. Then, a case study of an automotive manufacturing industry was conducted to demonstrate the proficiency of the proposed model. As a result, better understanding of capabilities of implemented supply chain management information systems and expected future capabilities could be identified by practitioners and decision makers. Finally, findings of this study are listed together with some future works

Order Processing in Supply Chain Management with Developing an Information System Model An Automotive Manufacturing Case Study

Nowadays, high competitive market needs fast, effective, high responsiveness, online interactive, 24 hours 7 days availability and easy to follow up order processing. Consequently, there is a need for a model in which interdisciplinary approaches for understanding the range of Supply Chain Management (SCM) Information System (IS) capabilities are provided. In this study, an integrated model of SCM IS was developed that is supported by empirical evidence specific to SCM IS implementations. The developed model integrates and enriches theories of competitive strategy, supply chain management and inter-organizational information systems. Then, a case study of an automotive manufacturing industry was conducted to demonstrate the proficiency of the proposed model. As a result, better understanding of capabilities of implemented supply chain management information systems and expected future capabilities could be identified by practitioners and decision makers. Finally, findings of this study are listed together with some future works

Neuroprotective and Anti-inflammatory Role of Atorvastatin and Its Interaction with Nitric Oxide (NO) in Chronic Constriction Injury-induced Neuropathic Pain

Prevention and treatment of neuropathic pain (NP) is one of the most difficult problems in clinical practice since the underlying mechanism of NP is unclear. In previous studies, the increased production of nitric oxide (NO) has been closely linked to the induced NP. In this study, we assessed the effect of atorvastatin through NO mechanism, on inflammation, thermal hyperalgesia, thermal allodynia, and mechanical allodynia as well as sciatic nerve histological score in rat with chronic constriction injury (CCI) model. Finally, we specified the role of cytokines such as TNF-alpha and IL-6 in the spinal cord. Treatment with atorvastatin and L-NAME (NO inhibitor) attenuated the thermal hyperalgesia, thermal allodynia and mechanical allodynia induced by CCI. The antinociceptive consequence was better elevated with a combination of atorvastatin and L-NAME in comparison with the other groups. In addition, the treatment with these drugs also attenuated the CCI-induced TNF-alpha and IL-6 level in the spinal cord. Furthermore, the histological analysis showed a low level of inflammation in the sciatic nerve in the CCI rats co treated with atorvastatin and L-NAME. Findings of our study in NP-induced CCI in the rat model demonstrate that inhibition of NO displays antinociceptive and anti-neuroinflammatory effects of atorvastatin in peripheral and central nervous system. In addition, we found that inhibition of the NO by atorvastatin could be one of the most important anti-inflammatory pathways of atorvastatin effect