Casing collapse is one of the major problems in oil fields, imposing a lot of costs on oil companies. This problem occurs not only at drilling times in some formations but also after the completion and production can lead to many problems. Analysis of the behavior of casing collapse in terms of geo-mechanics and solid mechanics could significantly meet the needs of the oil industry of Iran. In ...

Classical mechanics is formulated in Hilbert space with the introduction of a commutative product of operators, an antisymmetric bracket, and a quasidensity operator. These are analogues of the star product, the Moyal bracket, and the Wigner function in the phase space formulation of quantum mechanics. Classical mechanics can now be viewed as a deformation of quantum mechanics. The forms of sem...

background extraperitoneal laparoscopy has become a common technique for many surgical procedures, especially for inguinal hernia surgery. investigations of physiological changes occurring during extraperitoneal carbon dioxide (co2) insufflation mostly focused on blood gas changes. to date, the impact of extraperitoneal co2 insufflation on respiratory mechanics remains unknown, whereas changes ...

background & aim : low back pain (lbp) has developed as a major public health problem in the western industrialized societies, and the socio-economic burden of this problem has a huge dimension. the aim of this study was to investigate the effect of body mechanics behavior on lbp of workers.| methods & materials : descriptive study includes convenience sample of 290 workers who work at car prod...