Correlation Parameters for Eliminating the Effect of Pulse Shape on Dynamic Plastic Deformation

1970 ◽  
Vol 37 (3) ◽  
pp. 744-752 ◽  
Author(s):  
C. K. Youngdahl
Keyword(s):  
Plastic Deformation ◽  
Cylindrical Shell ◽  
Pulse Shape ◽  
Circular Cylindrical Shell ◽  
Strong Dependence ◽  
Uniform Pressure ◽  
Concentrated Force ◽  
Total Impulse ◽  
The Mean ◽  
Mean Time

The solutions to four classical problems in dynamic plasticity—the circular plate under uniform pressure, the reinforced circular cylindrical shell under uniform pressure, the free-free beam with a central concentrated force, and the circular cylindrical shell with a ring load—are examined to determine the effect of pulse shape on final plastic deformation. It is found that there is a strong dependence on pulse shape for pulses which have the same total impulse and maximum load; however, the effect of the pulse shape is virtually eliminated if the pulses have the same total impulse and “effective load.” The “effective load” is defined as the impulse divided by twice the mean time of the pulse, where the mean time is the interval between the onset of plastic deformation and the centroid of the pulse.

The Dynamics of Impulsively and Randomly Varying Systems

1963 ◽  
Vol 30 (1) ◽  
pp. 25-30 ◽  
Author(s):  
J. C. Samuels
Keyword(s):  
Cylindrical Shell ◽  
Integral Equations ◽  
Multiple Scattering ◽  
Critical Level ◽  
Circular Cylindrical Shell ◽  
Mean Square ◽  
The Mean ◽  
Light Integral ◽  
Multiple Scattering Of Light ◽  
Mean Square Solution

By a method, related somewhat to a technique used in the theory of he multiple scattering of light, integral equations are derived for the mean and mean-square solution of systems undergoing random changes. These equations are in essential agreement with similar equations derived elsewhere in the literature by completely different methods. The theory developed herein is applied to the analysis of a circular cylindrical shell under random end thrusts. It is found that the shell buckles when the mean-square value of the fluctuation of the end thrusts exceeds a certain critical level determined by damping.

scholarly journals Shaping a Middle Surface of Dished Head of a Circular Cylindrical Pressure Vessel

2010 ◽  
Author(s):  
J. Lewinski ◽  
K. Magnucki
Keyword(s):  
Cylindrical Shell ◽  
Numerical Calculation ◽  
Optimal Design ◽  
Pressure Vessel ◽  
Circular Cylindrical Shell ◽  
Middle Surface ◽  
Uniform Pressure ◽  
Optimal Shapes ◽  
Cylindrical Pressure Vessel ◽  
Shaping Process

The paper is devoted to a dished head of a pressure vessel subject to internal uniform pressure. A short survey of optimal design of a pressure vessel and its head is presented. The problem of shaping of middle surface of a dished head with the use of trigonometric series is depicted. As a criterion of the shaping process the continuity of curvatures of the surfaces in the joint of the circular cylindrical shell and the dished head is assumed. Results of the numerical calculation for optimal shapes of head are presented in figures.

Predicting Daily Maintenance Dose of Fluindione, an Oral Anticoagulant Drug

1996 ◽  
Vol 75 (05) ◽  
pp. 731-733 ◽  
Author(s):  
V Cazaux ◽  
B Gauthier ◽  
A Elias ◽  
D Lefebvre ◽  
J Tredez ◽  
...  
Keyword(s):  
Effective Dose ◽  
Maintenance Dose ◽  
Successive Approximations ◽  
Hemorrhagic Complication ◽  
Simple Method ◽  
Individual Variations ◽  
Anticoagulant Drug ◽  
The Mean ◽  
Mean Time ◽  
Daily Maintenance Dose

SummaryDue to large inter-individual variations, the dose of vitamin K antagonist required to target the desired hypocoagulability is hardly predictible for a given patient, and the time needed to reach therapeutic equilibrium may be excessively long. This work reports on a simple method for predicting the daily maintenance dose of fluindione after the third intake. In a first step, 37 patients were delivered 20 mg of fluindione once a day, at 6 p.m. for 3 consecutive days. On the morning of the 4th day an INR was performed. During the following days the dose was adjusted to target an INR between 2 and 3. There was a good correlation (r = 0.83, p<0.001) between the INR performed on the morning of day 4 and the daily maintenance dose determined later by successive approximations. This allowed us to write a decisional algorithm to predict the effective maintenance dose of fluindione from the INR performed on day 4. The usefulness and the safety of this approach was tested in a second prospective study on 46 patients receiving fluindione according to the same initial scheme. The predicted dose was compared to the effective dose soon after having reached the equilibrium, then 30 and 90 days after. To within 5 mg (one quarter of a tablet), the predicted dose was the effective dose in 98%, 86% and 81% of the patients at the 3 times respectively. The mean time needed to reach the therapeutic equilibrium was reduced from 13 days in the first study to 6 days in the second study. No hemorrhagic complication occurred. Thus the strategy formerly developed to predict the daily maintenance dose of warfarin from the prothrombin time ratio or the thrombotest performed 3 days after starting the treatment may also be applied to fluindione and the INR measurement.

Retrospective analysis of mortality within 30 days of systemic anticancer therapy and comparison with a previous audit at an Australian Regional Cancer Centre

2021 ◽  
pp. 107815522110160
Author(s):  
Bernadatte Zimbwa ◽  
Peter J Gilbar ◽  
Mark R Davis ◽  
Srinivas Kondalsamy-Chennakesavan
Keyword(s):  
Checkpoint Inhibitors ◽  
Anticancer Therapy ◽  
Mortality Rates ◽  
Feedback Process ◽  
Time To Death ◽  
Cancer Centre ◽  
Haematology Patients ◽  
The Mean ◽  
Regional Cancer Centre ◽  
Mean Time

Purpose To retrospectively determine the rate of death occurring within 14 and 30 days of systemic anticancer therapy (SACT), compare this against a previous audit and benchmark results against other cancer centres. Secondly, to determine if the introduction of immune checkpoint inhibitors (ICI), not available at the time of the initial audit, impacted mortality rates. Method All adult solid tumour and haematology patients receiving SACT at an Australian Regional Cancer Centre (RCC) between January 2016 and July 2020 were included. Results Over a 55-month period, 1709 patients received SACT. Patients dying within 14 and 30 days of SACT were 3.3% and 7.0% respectively and is slightly higher than our previous study which was 1.89% and 5.6%. Mean time to death was 15.5 days. Males accounted for 63.9% of patients and the mean age was 66.8 years. 46.2% of the 119 patients dying in the 30 days post SACT started a new line of treatment during that time. Of 98 patients receiving ICI, 22.5% died within 30 days of commencement. Disease progression was the most common cause of death (79%). The most common place of death was the RCC (38.7%). Conclusion The rate of death observed in our re-audit compares favourably with our previous audit and is still at the lower end of that seen in published studies in Australia and internationally. Cases of patients dying within 30 days of SACT should be regularly reviewed to maintain awareness of this benchmark of quality assurance and provide a feedback process for clinicians.

Vitamin D Level Stability in Dystrophinopathy Patients on Vitamin D Supplementation

2021 ◽  
pp. 1-7
Author(s):  
Naomi Vather-Wu ◽  
Matthew D. Krasowski ◽  
Katherine D. Mathews ◽  
Amal Shibli-Rahhal
Keyword(s):  
Vitamin D ◽  
Retrospective Cohort ◽  
Vitamin D Supplementation ◽  
Hydroxyvitamin D ◽  
Frequent Monitoring ◽  
25 Hydroxyvitamin D ◽  
The Mean ◽  
Stable Maintenance ◽  
Mean Time

Background: Expert guidelines recommend annual monitoring of 25-hydroxyvitamin D (25-OHD) and maintaining 25-OHD ≥30 ng/ml in patients with dystrophinopathies. Objective: We hypothesized that 25-OHD remains stable and requires less frequent monitoring in patients taking stable maintenance doses of vitamin D. Methods: We performed a retrospective cohort study, using the electronic health record to identify 26 patients with dystrophinopathies with a baseline 25-OHD ≥30 ng/mL and at least one additional 25-OHD measurement. These patients had received a stable dose of vitamin D for ≥3 months prior to their baseline 25-OHD measurement and throughout follow-up. The main outcome measured was the mean duration time the subjects spent with a 25-OHD ≥30 ng/mL. Results: Only 19% of patients dropped their 25-OHD to <  30 ng/ml, with a mean time to drop of 33 months and a median nadir 25-OHD of 28 ng/mL. Conclusions: These results suggest that measurement of 25-OHD every 2–2.5 years may be sufficient in patients with a baseline 25-OHD ≥30 ng/mL and who are on a stable maintenance dose of vitamin D. Other patients may require more frequent assessments.

scholarly journals Surveillance System in Smart Cities: A Dependability Evaluation Based on Stochastic Models

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 876
Author(s):  
Igor Gonçalves ◽  
Laécio Rodrigues ◽  
Francisco Airton Silva ◽  
Tuan Anh Nguyen ◽  
Dugki Min ◽  
...  
Keyword(s):  
Surveillance System ◽  
Smart Cities ◽  
Heterogeneous Data ◽  
Time To Failure ◽  
Video Streams ◽  
Dependability Evaluation ◽  
The Mean ◽  
Mean Time ◽  
The Internet Of Things

Surveillance monitoring systems are highly necessary, aiming to prevent many social problems in smart cities. The internet of things (IoT) nowadays offers a variety of technologies to capture and process massive and heterogeneous data. Due to the fact that (i) advanced analyses of video streams are performed on powerful recording devices; while (ii) surveillance monitoring services require high availability levels in the way that the service must remain connected, for example, to a connection network that offers higher speed than conventional connections; and that (iii) the trust-worthy dependability of a surveillance system depends on various factors, it is not easy to identify which components/devices in a system architecture have the most impact on the dependability for a specific surveillance system in smart cities. In this paper, we developed stochastic Petri net models for a surveillance monitoring system with regard to varying several parameters to obtain the highest dependability. Two main metrics of interest in the dependability of a surveillance system including reliability and availability were analyzed in a comprehensive manner. The analysis results show that the variation in the number of long-term evolution (LTE)-based stations contributes to a number of nines (#9s) increase in availability. The obtained results show that the variation of the mean time to failure (MTTF) of surveillance cameras exposes a high impact on the reliability of the system. The findings of this work have the potential of assisting system architects in planning more optimized systems in this field based on the proposed models.

scholarly journals The impact of COVID-19 infection on hip fracture 30-day mortality

Trauma ◽  
2021 ◽  
pp. 146040862094972
Author(s):  
Ahmed Fadulelmola ◽  
Rob Gregory ◽  
Gavin Gordon ◽  
Fiona Smith ◽  
Andrew Jennings
Keyword(s):  
Hip Fracture ◽  
Hip Fractures ◽  
Hospital Admissions ◽  
The Elderly ◽  
Primary Outcome Measure ◽  
Time To Death ◽  
Significant Difference ◽  
The Mean ◽  
The Impact ◽  
Mean Time

Introduction: A novel virus, SARS-CoV-2, has caused a fatal global pandemic which particularly affects the elderly and those with comorbidities. Hip fractures affect elderly populations, necessitate hospital admissions and place this group at particular risk from COVID-19 infection. This study investigates the effect of COVID-19 infection on 30-day hip fracture mortality. Method: Data related to 75 adult hip fractures admitted to two units during March and April 2020 were reviewed. The mean age was 83.5 years (range 65–98 years), and most (53, 70.7%) were women. The primary outcome measure was 30-day mortality associated with COVID-19 infection. Results: The COVID-19 infection rate was 26.7% (20 patients), with a significant difference in the 30-day mortality rate in the COVID-19-positive group (10/20, 50%) compared to the COVID-19-negative group (4/55, 7.3%), with mean time to death of 19.8 days (95% confidence interval: 17.0–22.5). The mean time from admission to surgery was 43.1 h and 38.3 h, in COVID-19-positive and COVID-19-negative groups, respectively. All COVID-19-positive patients had shown symptoms of fever and cough, and all 10 cases who died were hypoxic. Seven (35%) cases had radiological lung findings consistent of viral pneumonitis which resulted in mortality (70% of mortality). 30% ( n = 6) contracted the COVID-19 infection in the community, and 70% ( n = 14) developed symptoms after hospital admission. Conclusion: Hip fractures associated with COVID-19 infection have a high 30-day mortality. COVID-19 testing and chest X-ray for patients presenting with hip fractures help in early planning of high-risk surgeries and allow counselling of the patients and family using realistic prognosis.

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