The stability and mobility of proppant packs in hydraulic fractures during hydrocarbon production are numerically investigated by the lattice Boltzmann-discrete element coupling method(LB-DEM).This study starts with a...The stability and mobility of proppant packs in hydraulic fractures during hydrocarbon production are numerically investigated by the lattice Boltzmann-discrete element coupling method(LB-DEM).This study starts with a preliminary proppant settling test,from which a solid volume fraction of 0.575 is calibrated for the proppant pack in the fracture.In the established workflow to investigate proppant flowback,a displacement is applied to the fracture surfaces to compact the generated proppant pack as well as further mimicking proppant embedment under closure stress.When a pressure gradient is applied to drive the fluid-particle flow,a critical aperture-to-diameter ratio of 4 is observed,above which the proppant pack would collapse.The results also show that the volumetric proppant flowback rate increases quadratically with the fracture aperture,while a linear variation between the particle flux and the pressure gradient is exhibited for a fixed fracture aperture.The research outcome contributes towards an improved understanding of proppant flowback in hydraulic fractures,which also supports an optimised proppant size selection for hydraulic fracturing operations.展开更多
This article explores the intricate relationship between attachment styles formed during early childhood and the subsequent responses to traumatic events, particularly the death of a parent. Drawing on the theoretical...This article explores the intricate relationship between attachment styles formed during early childhood and the subsequent responses to traumatic events, particularly the death of a parent. Drawing on the theoretical framework of attachment theory and incorporating contemporary research, the paper discusses how parental interactions shape the neural circuitry of infants and children, influencing their ability to form secure or insecure attachments. These attachment styles, in turn, play a critical role in determining the child’s coping mechanisms when faced with trauma. This paper focuses on trying to understand how attachment theory is connected to the reaction to trauma with a highlight on the four major styles of attachments which are secure, anxious, avoidant, and disorganized to mention but a few, and how they influence stress and adversity in children. Attachment theory holds that human beings’ ability to form affectional bonds in infancy determines their patterns of relatedness across the life cycle. The type of attachment that is secure usually supports healthy adaptation and good coping mechanisms regardless of the trauma in the childhood of the child. While secure attachment mostly facilitates favorable trauma-related outcomes, anxious or avoidant attachment can exacerbate or alter the responses. The caregiving system that is avoidant attachment has implications of autonomous self-functioning which has features of suppression of the emotional response and poor search for emotional support during stress. From the principles of developmental psychology and trauma theory, the paper also focuses on the major significance of the child’s early caregivers’ interactions that define the resilience and vulnerability factor. This knowledge is therefore critical in designing specific interventions based on the improvement of coping behaviors and emotional regulatory systems of children who have been exposed to trauma. Finally, we have the synthesis of new knowledge about the role of secure attachment relationships as its fundamental element in shaping adaptive traumatization and psychological development. The article also delves into the physiological processes involved in emotional regulation and the role of cortisol in disrupting attachment. Finally, the implications of these findings for therapeutic interventions and the challenges of addressing prolonged grief and traumatic responses in clinical settings are considered.展开更多
基金Funding support from Heilongjiang"Open Competition"project(Grant No.DQYT2022-JS-758)is greatly acknowledgedFinancial support from the National Natural Science Foundation of China(Grant Nos.52304025 and 52174025)is acknowledged+1 种基金supports from Northeast Petroleum University and Guangdong Basic and Applied Basic Research Foundationsupport from the Heilongjiang Touyan Innovation Team Program.
文摘The stability and mobility of proppant packs in hydraulic fractures during hydrocarbon production are numerically investigated by the lattice Boltzmann-discrete element coupling method(LB-DEM).This study starts with a preliminary proppant settling test,from which a solid volume fraction of 0.575 is calibrated for the proppant pack in the fracture.In the established workflow to investigate proppant flowback,a displacement is applied to the fracture surfaces to compact the generated proppant pack as well as further mimicking proppant embedment under closure stress.When a pressure gradient is applied to drive the fluid-particle flow,a critical aperture-to-diameter ratio of 4 is observed,above which the proppant pack would collapse.The results also show that the volumetric proppant flowback rate increases quadratically with the fracture aperture,while a linear variation between the particle flux and the pressure gradient is exhibited for a fixed fracture aperture.The research outcome contributes towards an improved understanding of proppant flowback in hydraulic fractures,which also supports an optimised proppant size selection for hydraulic fracturing operations.
文摘This article explores the intricate relationship between attachment styles formed during early childhood and the subsequent responses to traumatic events, particularly the death of a parent. Drawing on the theoretical framework of attachment theory and incorporating contemporary research, the paper discusses how parental interactions shape the neural circuitry of infants and children, influencing their ability to form secure or insecure attachments. These attachment styles, in turn, play a critical role in determining the child’s coping mechanisms when faced with trauma. This paper focuses on trying to understand how attachment theory is connected to the reaction to trauma with a highlight on the four major styles of attachments which are secure, anxious, avoidant, and disorganized to mention but a few, and how they influence stress and adversity in children. Attachment theory holds that human beings’ ability to form affectional bonds in infancy determines their patterns of relatedness across the life cycle. The type of attachment that is secure usually supports healthy adaptation and good coping mechanisms regardless of the trauma in the childhood of the child. While secure attachment mostly facilitates favorable trauma-related outcomes, anxious or avoidant attachment can exacerbate or alter the responses. The caregiving system that is avoidant attachment has implications of autonomous self-functioning which has features of suppression of the emotional response and poor search for emotional support during stress. From the principles of developmental psychology and trauma theory, the paper also focuses on the major significance of the child’s early caregivers’ interactions that define the resilience and vulnerability factor. This knowledge is therefore critical in designing specific interventions based on the improvement of coping behaviors and emotional regulatory systems of children who have been exposed to trauma. Finally, we have the synthesis of new knowledge about the role of secure attachment relationships as its fundamental element in shaping adaptive traumatization and psychological development. The article also delves into the physiological processes involved in emotional regulation and the role of cortisol in disrupting attachment. Finally, the implications of these findings for therapeutic interventions and the challenges of addressing prolonged grief and traumatic responses in clinical settings are considered.
