in this paper, a rectangular sandwich plate with a constrained layer and an electrorheological (er) fluid core is investigated. the rectangular plate is covered an er fluid core and a constraining layer to improve the stability of the system. the two outer layers of the sandwich structure are elastic. the viscoelastic materials express the middle layer behavior under electric field and small st...

cementing is an essential part of every drilling operation. protection of the wellbore from formation fluid invasion is one of the primary tasks of a cement job. failure in this task results in catastrophic events, such as blow outs. hence, in order to save the well and avoid risky and operationally difficult remedial cementing, slurry must be optimized to be resistant against gas migration phe...

This paper presents the results of experimental investigations of a precision sensor for an automatic weapons stabilizer system. It also describes the experimental equipment used and the structure of the developed sensor. A weapons stabilizer is designed for automatic guidance of an armament unit in the horizontal and vertical planes when firing at ground and air targets that are quickly maneuv...

This paper considers the stabilization of planar switched linear control systems. First, a structure property of not completely controllable pair (A, b) is revealed. Based on it, a simply verifiable, necessary and sufficient condition for the planar switched linear control system to be feedback stabilizable, is presented under the assumption that the switching law is designable. The proof provi...

Multiple-factor analysis and optimization play a critical role in the the ability to maximizethe stimulated reservoir volume (SRV) and the success of economic shale gas production. In this paper, taking the typical continental naturally fractured silty laminae shale in China as anexample, response surface methodology (RSM) was employed to optimize multiple hydraulic fracturing parameters to max...

Clifford codes are a class of quantum error control codes that form a natural generalization of stabilizer codes. These codes were introduced in 1996 by Knill, but only a single Clifford code was known, which is not already a stabilizer code. We derive a necessary and sufficient condition that allows to decide when a Clifford code is a stabilizer code, and compile a table of all true Clifford c...

This article is focused on the implementation of Fuzzy Logic Controller based Power system Stabilizer to enhanced transient stability of the multi machine system. Power system is very complex as well as highly nonlinear system. At present, there are different control mechanism used to control excitation system of the generator to enhance stability of system. Power system stabilizer (PSS) instal...

In shale, liquid hydrocarbons are accumulated mainly in nanometer-scale pores or fractures, so the pore types and PSDs (pore size distributions) play a major role in the shale oil occurrence (free or absorbed state), amount of oil, and flow features. The pore types and PSDs of marine shale have been well studied; however, research on lacustrine shale is rare, especially for shale in the oil gen...

In the process of exploitation deep oil and gas resources, shale wellbore stability control faces great challenges under complex temperature pressure conditions. It is difficult to reflect micro mechanism action inorganic salt on hydration with traditional experimental evaluation technology macro effect restraining hydration. Aiming at characteristics clay minerals shale, molecular dynamics mod...

Reservoir shale has the characteristics of bedding planes, strong anisotropy, and imbibition ability under ultralow water saturation, which an important impact on wellbore stability horizontal wells. Therefore, physical chemical properties reservoir were analyzed, a mechanics model was established considering elasticity strength anisotropy. The analyzed anisotropy parameters formation condition...