Elimination of membrane compliance in undrained triaxial testing.II. Mitigation by injection compensation

1993 ◽  
Vol 30 (5) ◽  
pp. 739-746 ◽  
Author(s):  
P.G. Nicholson ◽  
R.B. Seed ◽  
H.A. Anwar
Keyword(s):  
Large Scale ◽  
Closed Loop ◽  
Injection System ◽  
Triaxial Testing ◽  
Granular Soils ◽  
Confining Stress ◽  
Controlled System ◽  
Computer Controlled ◽  
Large Scale Tests ◽  
Correction System

A computer-controlled injection-correction system has been developed to continuously and completely mitigate the adverse effects of membrane compliance for undrained testing of granular soils. The system was developed with the explicit idea that it could be quickly and easily adapted to most any up to date triaxial testing apparatus. A relationship between effective confining stress and volumetric compliance can be predetermined, as volumetric-compliance errors have been shown to be a direct and repeatable function of effective confining stresses for a given material. The predetermination of volumetric-compliance errors represents a suitable basis for control of injection–removal compensation for membrane compliance during undrained testing. A closed-loop computer-controlled system continuously monitors changes in sample effective confining stresses such that precalculated volumetric-compliance errors can be continuously offset by injecting or removing volumes of water equal to those errors throughout the duration of each test. The validity of the injection system was verified by comparison of the compensated tests to results of large-scale (300 mm diameter) tests of the same materials, as compliance effects for large-scale tests of this material were negligible. Key words : membrane, penetration, compliance, undrained testing, triaxial, compensation, liquefaction.

scholarly journals Consumption of Cisatracurium in different age groups, using a closed loop computer controlled system

2014 ◽  
Vol 14 (1) ◽  
Author(s):  
Shehzaad Joomye ◽  
Donglai Yan ◽  
Haiyun Wang ◽  
Guoqiang Zhou ◽  
Guolin Wang
Keyword(s):  
Closed Loop ◽  
Age Groups ◽  
Controlled System ◽  
Computer Controlled

scholarly journals Efficacy of the anterior and middle superior alveolar nerve block in achieving pulpal anesthesia of maxillary teeth

2019 ◽  
Vol 147 (7-8) ◽  
pp. 400-404
Author(s):  
Slavoljub Tomic ◽  
Lado Davidovic ◽  
Djordje Bozovic ◽  
Mihael Stanojevic ◽  
Smiljka Cicmil ◽  
...  
Keyword(s):  
Local Anesthesia ◽  
Nerve Block ◽  
Local Anesthetic ◽  
Injection System ◽  
Alternative Technique ◽  
Controlled System ◽  
Computer Controlled ◽  
Pulpal Anesthesia ◽  
Slow Onset

Introduction. The anterior and middle superior alveolar (AMSA) nerve block is an alternative technique of local anesthesia in the maxilla, unpredictably efficient for pulpal anesthesia. The aim of this study was to determine the anesthetic efficacy of the AMSA injection for pulpal anesthesia, using computer-controlled injection system or conventional syringe, and two local anesthetic solutions with or without adrenaline. Methods. The authors administered two AMSA injections during two separate appointments, utilizing the computer-controlled system and conventional syringe to 40 subjects, divided into two groups of 20 subjects each depending on the local anesthetic used. A pulp tester was used to test the achieved anesthesia of the central and lateral incisors, canine, first and second premolars, and the first molar in 10-minute cycles over a period of 60 minutes. Duration of anesthesia for all the mentioned teeth was also determined for both the anesthetic solutions and ways of application. Results. The AMSA injection with both types of equipment was successful, showing slow onset, satisfying intensity, and declining duration of pulpal anesthesia at the last two measurements. Local anesthetic with vasoconstrictor exhibited a significantly longer pulpal anesthesia. Conclusion. The AMSA nerve block could be recommended for achieving pulpal anesthesia of maxillary teeth from the region of the first incisor to the second premolar.

Reliability of nonlinear stochastic controlled systems considering the dynamics of sensors and actuators

2021 ◽  
pp. 107754632110037
Author(s):  
Sun Jiaojiao ◽  
Xia Lei ◽  
Ying Zuguang ◽  
Huan Ronghua ◽  
Zhu Weiqiu
Keyword(s):  
Closed Loop ◽  
First Passage Time ◽  
Hamiltonian Function ◽  
Small Time ◽  
Kolmogorov Equation ◽  
Sensors And Actuators ◽  
First Passage ◽  
Controlled System ◽  
Main Structure ◽  
Controlled Systems

A closed-loop controlled system usually consists of the main structure, sensors, and actuators. The dynamics of sensors and actuators may influence the motion of the main structure. This article presents an analytical study on the first-passage reliability of a nonlinear stochastic controlled system under the consideration of the dynamics of sensors and actuators. The coupled dynamic equations of the controlled systems with sensors and actuators are first given, which are further integrated into a controlled, randomly excited, dissipated Hamiltonian system. By applying the stochastic averaging method for quasi-Hamiltonian systems, a one-dimensional averaged differential equation for the Hamiltonian function is obtained. The backward Kolmogorov equation associated with the averaged equation is then derived for the first-passage reliability analysis, from which the approximate reliability function and probability density of first-passage time are obtained. The accuracy of the proposed procedure is demonstrated by an example. A comparative analysis of the reliability of the system with/without sensors and actuators is carried out, which indicates that ignoring sensors and actuators will make underestimation of the reliability of the closed-loop system with small time. However, when time increases, there appears the opposite trend. Our findings provide a reference for control strategy design.

The Design of Firing Mechanism Controlling Research of Natural Gas Vehicle Cylinder

2013 ◽  
Vol 333-335 ◽  
pp. 2044-2051
Author(s):  
Wei Pu Xu ◽  
Yi Ting Liu
Keyword(s):  
Natural Gas ◽  
Data Acquisition ◽  
Wireless Network ◽  
Fire Test ◽  
General Idea ◽  
Security Risks ◽  
Controlled System ◽  
Video Systems ◽  
Computer Controlled ◽  
Natural Gas Vehicle

This article described the current situation and the security risks of the natural gas vehicle cylinders, which introduced the principle of the fire test, proposed the general idea of the fire test equipment. Wireless network, video systems, data acquisition systems and computer-controlled system of the equipment researching are also introduced.

scholarly journals Implantable computer-controlled adaptive multielectrode positioning system

2018 ◽  
Vol 119 (4) ◽  
pp. 1471-1484 ◽  
Author(s):  
E. Ferrea ◽  
L. Suriya-Arunroj ◽  
D. Hoehl ◽  
U. Thomas ◽  
A. Gail
Keyword(s):  
Cerebral Cortex ◽  
Large Scale ◽  
Nonhuman Primates ◽  
Tissue Response ◽  
High Signal ◽  
Signal Quality ◽  
Positioning System ◽  
Multielectrode Arrays ◽  
User Friendliness ◽  
Computer Controlled

Acute neuronal recordings performed with metal microelectrodes in nonhuman primates allow investigating the neural substrate of complex cognitive behaviors. Yet the daily reinsertion and positioning of the electrodes prevents recording from many neurons simultaneously, limiting the suitability of these types of recordings for brain-computer interface applications or for large-scale population statistical methods on a trial-by-trial basis. In contrast, chronically implanted multielectrode arrays offer the opportunity to record from many neurons simultaneously, but immovable electrodes prevent optimization of the signal during and after implantation and cause the tissue response to progressively impair the transduced signal quality, thereby limiting the number of different neurons that can be recorded over the lifetime of the implant. Semichronically implanted matrices of electrodes, instead, allow individually movable electrodes in depth and achieve higher channel count compared with acute methods, hence partially overcoming these limitations. Existing semichronic systems with higher channel count lack computerized control of electrode movements, leading to limited user-friendliness and uncertainty in depth positioning. Here we demonstrate a chronically implantable adaptive multielectrode positioning system with detachable drive for computerized depth adjustment of individual electrodes over several millimeters. This semichronic 16-channel system is designed to optimize the simultaneous yield of units in an extended period following implantation since the electrodes can be independently depth adjusted with minimal effort and their signal quality continuously assessed. Importantly, the electrode array is designed to remain within a chronic recording chamber for a prolonged time or can be used for acute recordings with high signal-to-noise ratio in the cerebral cortex of nonhuman primates. NEW & NOTEWORTHY We present a 16-channel motorized, semichronic multielectrode array with individually depth-adjustable electrodes to record in the cerebral cortex of nonhuman primates. Compared with fixed-geometry arrays, this system allows repeated reestablishing of single neuron isolation. Compared with manually adjustable arrays it benefits from computer-controlled positioning. Compared with motorized semichronic systems it allows higher channel counts due to a robotic single actuator approach. Overall the system is designed to optimize the simultaneous yield of units over the course of implantation.

Sign in / Sign up

Export Citation Format

Share Document