Acute Angle-Closure—A Rare but Vision-Threatening Ocular Adverse Effect of Selective Serotonin Reuptake Inhibitors

Acute angle closure (AAC) is a relatively rare but serious ophthalmological condition in which early diagnosis and intraocular pressure (IOP) -lowering treatment play a key role in prognosis. The aim of this review is to present current understanding of the pathophysiology, symptoms, diagnosis, potential mechanisms as well as management of AAC associated with the use of selective serotonin reuptake inhibitors (SSRIs). In most cases, AAC in individuals receiving SSRIs occurs in the pupillary block mechanism, secondary to SSRI-induced mydriasis. However, SSRIs may also cause uveal effusion and, consequently, iridocorneal angle closure. Other factors such as impaired metabolism and elimination of SSRIs, individual genetic conditions, as well as inhibition of SSRIs metabolism due to the effects of other drugs used may also promote AAC.

STUDY OF THE DYNAMICS OF THE TRAVELING BLOCK-CROWN BLOCK MECHANISM OF THE DRILLING RIG WITH TWO ACTIVE DRAWWORKS

"In the hoisting equipment, the hoisting or lowering of the load at the hook is done with the drilling cable that connects the sheaves from the crown-block and those from the travelling-block. Failure of the drilling line can have catastrophic effects, hence it is very important to evaluate as accurately as possible the values of the lines tensions, so that during the drilling operations they do not exceed their tensile limits. The present paper deals with the study regarding the dynamics of the of the travelling block- crown block mechanism with two active drawworks and is establishing the expressions for calculation of the tensions from the drilling lines, depending on the load applied at the hook during both hoisting and lowering operations. The calculation is performed for the case of the travelling block-crown block mechanism provided with 3 respectively 4 sheaves and the values of the lines tensions for a hoisting equipment with two active drawworks are compared with the values for the conventional hoisting equipment. "

Block Mechanism of Microclearance Block Liquid and Lifting Height Calculating

Mechanical seal mechanism was applied to study block mechanism of gaswell microclearance block liquid for the first time, which explained block mechanism of microclearance block liquid. The paper has built a block physical model of microclearance block liquid and has got calculation formulas of the block liquid lifting height. Then the block liquid lifting heights were calculated and analyzed in different microclearance widths and pressures. The sealing effect of the block liquid was discussed. The analyzed results showed that sealing effect of the block liquid was very obvious when microclearance width was lesser than 12μm. The paper not only enriched the study on block mechanism of gaswell microclearance block liquid but also proposed theoretical guidance to solve radically gas migration problem of micro-annulus.