Dynamic Analysis of a 1T3R Parallel Stable Platform

2013 ◽  
Vol 850-851 ◽  
pp. 616-619
Author(s):  
Li Feng Fang ◽  
An Xing Liu ◽  
Xiao Nan Zhang ◽  
Xing Long Zhang
Keyword(s):  
Theoretical Analysis ◽  
Dynamic Analysis ◽  
Set Theory ◽  
Euler Method ◽  
Ball Screw ◽  
Spherical Joint ◽  
Force Analysis ◽  
The Moment ◽  
Full Consideration

Based on POC set theory and SOC unit, a 1T3R parallel stable platform is proposed. The Single cylinder force analysis is studied. Then uses Newton-Euler method, gives full consideration to these various factors: without neglecting the ball screw rotation, friction between the spherical joint, the mass and the moment of inertia of electric cylinders, based above the dynamic theoretical Analysis of the stable platform is researched. The paper makes the guide sense for the follow-up research and the application of the 1T3R mechanism.

Ferric sulfate as pulpotomy agent in primary teeth: twenty month clinical follow-up

2000 ◽  
Vol 24 (4) ◽  
pp. 269-272 ◽  
Author(s):  
Hamijeta Ibricevic ◽  
Qumasha Al-Jame
Keyword(s):  
Success Rate ◽  
Primary Teeth ◽  
Root Resorption ◽  
Clinical Success ◽  
Clinical Success Rate ◽  
Ferric Sulfate ◽  
Primary Molar ◽  
Molar Teeth ◽  
The Moment

Seventy primary molar teeth, carious exposed, symptom free, without any sign of root resorption in children aged from 3 to 6 years (main age 4.3yr) were treated with conventional pulpotomy procedures. Ferric sulfate 15.5% solution (applied for 15 second for 35 teeth) and formocresol solution (five minute procedure of Buckley's formula for next 35 teeth) have been used as pulpotomy agents. In both groups, pulp stumps were covered with zinc-oxide eugenol paste. Permanent restorations were stainless steel crowns. Clinical check up was every three-months and radiographic follow-up time was six and twenty months after treatment. Our results within this period revealed 100% clinical success rate in both groups. Radiographic success rate was in both groups 97.2%, while in 2.8% cases has shown internal root resorption. On the basis of these results, we can recommend ferric sulfate as a pulpotomy agent in primary teeth in substitution for formocresol at the moment.

scholarly journals Time and Frequency Domain Dynamic Analysis of Offshore Mooring

2021 ◽  
Vol 9 (7) ◽  
pp. 781
Author(s):  
Shi He ◽  
Aijun Wang
Keyword(s):  
Dynamic Analysis ◽  
Frequency Domain ◽  
Time Domain ◽  
Linearization Method ◽  
Euler Method ◽  
Single Component ◽  
Hydrodynamic Drag ◽  
Lumped Mass ◽  
Mooring Lines ◽  
The Time Domain

The numerical procedures for dynamic analysis of mooring lines in the time domain and frequency domain were developed in this work. The lumped mass method was used to model the mooring lines. In the time domain dynamic analysis, the modified Euler method was used to solve the motion equation of mooring lines. The dynamic analyses of mooring lines under horizontal, vertical, and combined harmonic excitations were carried out. The cases of single-component and multicomponent mooring lines under these excitations were studied, respectively. The case considering the seabed contact was also included. The program was validated by comparing with the results from commercial software, Orcaflex. For the frequency domain dynamic analysis, an improved frame invariant stochastic linearization method was applied to the nonlinear hydrodynamic drag term. The cases of single-component and multicomponent mooring lines were studied. The comparison of results shows that frequency domain results agree well with nonlinear time domain results.

scholarly journals Progressive Scoliosis and Syringomyelia - Questions of Surgical Approach

Folia Medica ◽  
2018 ◽  
Vol 60 (2) ◽  
pp. 261-269 ◽  
Author(s):  
Mikhail Mikhaylovskiy ◽  
Vyacheslav Stupak ◽  
Vadim Belozerov ◽  
Nikolay Fomichev ◽  
Anatoliy Lutsik ◽  
...  
Keyword(s):  
Surgical Intervention ◽  
Surgical Correction ◽  
Neurological Deficits ◽  
Spinal Deformities ◽  
Loss Of Correction ◽  
Scoliotic Deformity ◽  
Scoliosis Correction ◽  
The Moment ◽  
Comparison Of The Results

Abstract Background: The rate of scoliosis in syringomyelia patients ranges from 25 to 74.4%. In turn, syringomyelia occurs in 1.2% to 9.7% of scoliosis patients. Aim: To evaluate outcomes of surgical correction of the scoliotic deformity in syringomyelia patients. Materials and methods: Between 1996 and 2015, 3120 patients with scoliosis of various etiologies were treated at the Clinic for Child and Adolescent Vertebrology of the Novosibirsk Research Institute of Traumatology and Orthopedics. We conducted a retrospective analysis of syringomyelia-associated scoliosis cases that required surgical correction. Results: Syringomyelia was found in 33 patients (1.05%) out of 3120 patients with spinal deformities of various etiologies; in 21 patients (0.9%) with idiopathic scoliosis of 2334 patients. In identifying the neurological deficit, the recommended first step is to perform neurosurgery. Nineteen patients were operated using the CDI, 4 patients underwent correction VEPTR, in 1 case instrumentation could not be established, 9 patients are undergoing treatment in the department of neurosurgery at the moment. Worsening of neurological deficits was not observed in any patient. Conclusion: A comparison of the results of syringomyelia-associated scoliosis correction with the data of other authors was done. The choice of surgery tactics is strictly individual and depends on the size of the cavity. The result of surgical intervention is generally positive and the loss of correction by the end of follow-up is negligible.

scholarly journals RETROSPECTIVE ANALYSIS OF EVENTS OF DEATH AT HOME AMONG PATIENTS UNDER FOLLOW-UP OBSERVATION

2018 ◽  
Vol 35 (1) ◽  
pp. 68-74
Author(s):  
Ya P Sandakov
Keyword(s):  
Cardiovascular Diseases ◽  
Medical Records ◽  
Emergency Calls ◽  
Significant Difference ◽  
Duration Of Disease ◽  
The Moment ◽  
Age Of Death ◽  
At Home

Aim. To study the peculiarities of asking for medical care by patients from among those dead at home, who had been under follow-up observation. Materials and methods. The data, received from ambulatory medical records of 100 dead at home patients with follow-up, were analyzed using the methods of descriptive and inductive statistics. Results. A mean age of death was 74.9 ± 13.4 years, men - 65.8 ± 14.1 years, women - 79.2 ± 10.9 years. Cardiovascular diseases were the cause of follow-up observation in 78 % of cases and the cause of death in 85 %; in 30 % of patients the disease was detected while carrying out prophylactic medical examination. A mean duration of disease by the moment of death was 13.0 ± 8.0 years, among pensioners 13.7 ± 8.5 years, in able-bodied persons 9.6 ± 4.3 years. A mean duration of follow-up observation was 9.2 ± 5.8 years. An average number of planned visits was 2.8 ± 0.89, but the number of real visits during the last year of follow-up observation was 2.4 ± 1.2. Disability was registered in 77.6 % of patients, concomitant diseases - in all patients. For the last year, exacerbations were recorded in 92 % of patients, emergency calls - in 80 %, hospitalization events - 52 %, including 55.8 % - urgent ones. Conclusions. The absence of significant difference regarding the duration of disease between pensioners and able-bodied patients (т = 0.16, р = 1.43) as well as the absence of correlation between the age and duration of disease (χ2 = 0.19, p = 0.2) indirectly prove the influence of duration of disease on its outcome, but not the age. Attendance, characterizing clinical loyalty to treatment, does not depend on age (χ2 = -0.19, р = 0.18), sex (т = 1.0, р = 0.32), way of detecting disease (f = 0.9, p = 0.4), class of main disease (f = 0.91, p = 0.44), duration of disease (χ2 = -0.13, р = 0.49), exacerbations (χ2 = -0.17, р = 0.24), concomitant diseases (χ2 = 0.006, р = 0.9). The number of emergency calls, hospitalizations, urgent hospitalizations does not depend on duration of follow-up observation, regularity and number of real visits to a doctor (p > 0.05) that indicates unsatisfactory quality of follow-up observation.

scholarly journals Procedure of complex braided wrapping of ascending aorta in her poststenotic dilation while doing correction of aortal stenosis

2020 ◽  
Vol 87 (9-10) ◽  
pp. 18-21
Author(s):  
V. V. Popov ◽  
A. A. Bolshak
Keyword(s):  
Ascending Aorta ◽  
Main Group ◽  
Surgical Correction ◽  
Control Group ◽  
Valve Prosthesis ◽  
Original Procedure ◽  
Aortal Valve ◽  
The Moment ◽  
Aorta Diameter

Objective. To study clinical possibilities of original procedure of the ascending aorta braid-like bandage for her poststenotic dilation while performance of the aortal stenosis surgical correction. Materials and methods. To the main Group 196 patients were included those, who were operated on for prevailing aortal stenosis, conjoined with poststenotic dilation of ascending aorta. In accordance to the echocardiographic investigation data the ascending aorta diameter preoperatively have constituted (47.7 ± 1.7) mm. In all the patients the aortal valve prosthesis was performed together with complex braided wrapping of ascending aorta. Into the control group 121 patients were included, in whom Bentall intervention was accomplished with vascular prosthesis of ascending aorta. Results. Hospital lethality in the main group have constituted 0.5%. Diameter of ascending aorta in the moment of hospital discharge have constituted (39.1 ± 1.5) mm, and in late follow-up period - (40.3 ± 1.1) mm. Conclusion. Basing on clinical experience gained, it is expedient to recommend the original procedure of braided wrapping of ascending aorta in presence of her poststenotic dilation while performing surgical correction of prevailing aortal stenosis.

Dynamic Modeling of a Multi-Legged Robotic Vehicle: Part 2 — Dynamic Analysis

1987 ◽  
Author(s):  
R. A. Hart ◽  
N. D. Ebrahimi
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Model ◽  
Dynamic Modeling ◽  
Kinetic Equations ◽  
Euler Method ◽  
Degree Of Freedom ◽  
Time Response ◽  
Robotic Vehicle

Abstract In Part 1 of this report, we described the overall objective of the investigation; that is, the formulation of a dynamic model for determining the time response of a multi-legged robotic vehicle traveling on a variable-topographic terrain. Specifically, we developed expressions for the joint variables, and their rates, which are essential for describing the system’s links orientations, velocities, and accelerations. This procedure enabled us to determine the kinematic quantities associated with the entire vehicular system in accordance with the Newton-Euler method. In the present paper, we formulate the kinetic equations for the multi-degree-of-freedom leg assemblies, the rigid wheels, and the platform of the vehicle to achieve the prescribed motion and corresponding configuration of the system.

scholarly journals Intrauterine Device Insertion during Cesarean Section in Women without Prenatal Contraception Counseling: Lessons from a Country with High Cesarean Rates

2019 ◽  
Vol 41 (08) ◽  
pp. 485-492
Author(s):  
Alberto Moreno Zaconeta ◽  
Ana Carolina Oliveira ◽  
Flavielly Souza Estrela ◽  
Thalia Maia Vasconcelos ◽  
Paulo Sergio França ◽  
...  
Keyword(s):  
Cohort Study ◽  
Cesarean Section ◽  
Removal Rate ◽  
Intrauterine Device ◽  
Uterine Perforation ◽  
Cesarean Sections ◽  
Trial Of Labor ◽  
The Moment ◽  
Contraception Counseling

Objective The moment of admission for delivery may be inappropriate for offering an intrauterine device (IUD) to women without prenatal contraception counseling. However, in countries with high cesarean rates and deficient prenatal contraception counseling, this strategy may reduce unexpected pregnancies and repeated cesarean sections. Methods This was a prospective cohort study involving 100 women without prenatal contraception counseling. Postplacental IUD was offered after admission for delivery and placed during cesarean. The rates of IUD continuation, uterine perforation, and endometritis were assessed at 6 weeks and 6 months, and the proportion of women continuing with IUD at 6 months was assessed with respect to the number of previous cesareans. Results Ninety-seven women completed the follow-up. The rate of IUD continuation was 91% at 6 weeks and 83.5% at 6 months. The expulsion/removal rate in the first 6 weeks was not different from that between 6 weeks and 6 months (9 vs 9.1%, respectively). There were 2 cases of endometritis (2.1%), and no case of uterine perforation. Among 81 women continuing with intrauterine device after 6-months, 31% had undergone only the cesarean section in which the IUD was inserted, 44% had undergone 2 and 25% had undergone 3 or more cesarean sections. Conclusion Two thirds of the women who continued with IUD at 6 months had undergone 2 or more cesarean sections. Since offering trial of labor is unusual after 2 or more previous cesareans, we believe that offering IUD after admission for delivery may reduce the risk of repeated cesarean sections and its inherent risks.

Moment formulas for the Markov renewal branching process

1976 ◽  
Vol 8 (4) ◽  
pp. 690-711 ◽  
Author(s):  
Marcel F. Neuts
Keyword(s):  
Steady State ◽  
Numerical Computation ◽  
Busy Period ◽  
Branching Process ◽  
Queueing Models ◽  
Absorption Time ◽  
The Mean ◽  
The Moment

There are many queueing models in which there appears a semi-Markov matrix G(·), whose entries are absorption-time distributions in a Markov renewal branching process. The role of G(·) is similar to that of the busy period in the simple M/G/1 model. The computation of various quantities associated with G(·) is however much more complicated. The moment matrices, and particularly the mean matrix of G(·), are essential in the construction of general and mathematically well-justified algorithms for the steady-state distributions of such queues.This paper discusses the moment matrices of G(·) and algorithms for their numerical computation. Its contents are basic to the algorithmic solutions to several queueing models, which are to be presented in follow-up papers.

Study on Plane Magnetic Abrasive Finishing Process - Experimental and Theoretical Analysis on Polishing Trajectory -

2010 ◽  
Vol 126-128 ◽  
pp. 1023-1028 ◽  
Author(s):  
Yan Hua Zou ◽  
An Yuan Jiao ◽  
Toshio Aizawa
Keyword(s):  
Theoretical Analysis ◽  
Influence Factor ◽  
Polishing Process ◽  
Magnetic Abrasive Finishing ◽  
Abrasive Finishing ◽  
Designed Experiment ◽  
Linear Movement ◽  
Magnetic Abrasive Polishing ◽  
The Moment ◽  
Surface Precision

This research studies an effective polishing process to elevate the surface precision and homogeneity by improving the polishing trajectory of magnetic brush. The moment of magnetic brush is a key influence factor on finishing characteristics, but in conventional plane magnetic abrasive Polishing process, the movements of magnetic brush is relatively simple. In this paper a polishing process using the complex polishing trajectory of magnetic brush has been modified and studied by use of newly designed experiment device. The linear movement of workpiece, the rotation and revolution or movement in XY coordinate plane of magnetic brush can be realized by this device. In comparison with conventional method, variation regularity about surface roughness and the material removal are been studied. According to experimental results for polishing trajectory of magnetic brush, finishing characteristics was clarified. The results show that studies on polishing trajectory of magnetic brush are more valuable and the experimental researches are consistent with theoretical analysis. In addition, the accuracy of plane magnetic abrasive finishing can be elevated in terms of the reasonable planning for polishing trajectory of magnetic brush.

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