scholarly journals A Laser-Based Noncontact Vibration Technique for Health Monitoring of Structural Cables: Background, Success, and New Developments

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Armin B. Mehrabi ◽  
Saman Farhangdoust
Keyword(s):  
Health Monitoring ◽  
High Stress ◽  
Well Being ◽  
Laser Vibrometer ◽  
Stress Concentrations ◽  
Vibration Data ◽  
Stay Cables ◽  
Vibration Technique ◽  
Cable Force ◽  
Structural Cables

Structural cables are susceptible to the effects of high stress concentrations, corrosion, and wind-induced and other vibrations. Cables are normally the most critical elements in a cable-supported structure and their well-being is very important in the health of the structure. The laser-based vibration technique discussed in this paper is a means for health monitoring of cables and therefore the entire cable-supported structure. This technique uses a noncontact remote sensing laser vibrometer for collecting cable vibration data from distances of up to several hundreds of feet and determines its dynamic characteristics including vibration frequencies and damping ratios. A formulation specifically developed for structural cables capable of accounting for important cable parameters is then used to calculate the cable force. Estimated forces in the cables are compared to previously measured forces or designer’s prediction to detect patterns associated with damage to the cable itself and/or changes to the structure elsewhere. The estimated damping ratios are also compared against predefined criteria to infer about susceptibility against wind-induced vibrations and other vibrations. The technique provides rapid, effective, and accurate means for health monitoring of cable-supported structures. It determines the locations and elements with potential damage and the need for detailed and hands on inspection. To date, the technique has been used successfully for evaluation of twenty-five major bridges in the US and abroad. Though originally devised for condition assessment of stay cables, it has been developed further to include a variety of systems and conditions among them structural hanger ropes in suspension, truss, and arch supported bridges, ungrouted stay cables, cables with cross-ties, and external posttensioning tendons in segmental bridge construction. It has also found a valuable place in construction-phase activities for verification of forces in tension elements with minimal efforts. Future endeavors for automation and aerial delivery are being considered for this technique.

scholarly journals Long-Term IoT-Based Maternal Monitoring: System Design and Evaluation

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2281
Author(s):  
Fatemeh Sarhaddi ◽  
Iman Azimi ◽  
Sina Labbaf ◽  
Hannakaisa Niela-Vilén ◽  
Nikil Dutt ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Maternal Health ◽  
Pregnant Women ◽  
Health Monitoring ◽  
Quality Care ◽  
Well Being ◽  
Pregnancy And Postpartum ◽  
Comprehensive Framework ◽  
Specific Health

Pregnancy is a unique time when many mothers gain awareness of their lifestyle and its impacts on the fetus. High-quality care during pregnancy is needed to identify possible complications early and ensure the mother’s and her unborn baby’s health and well-being. Different studies have thus far proposed maternal health monitoring systems. However, they are designed for a specific health problem or are limited to questionnaires and short-term data collection methods. Moreover, the requirements and challenges have not been evaluated in long-term studies. Maternal health necessitates a comprehensive framework enabling continuous monitoring of pregnant women. In this paper, we present an Internet-of-Things (IoT)-based system to provide ubiquitous maternal health monitoring during pregnancy and postpartum. The system consists of various data collectors to track the mother’s condition, including stress, sleep, and physical activity. We carried out the full system implementation and conducted a real human subject study on pregnant women in Southwestern Finland. We then evaluated the system’s feasibility, energy efficiency, and data reliability. Our results show that the implemented system is feasible in terms of system usage during nine months. We also indicate the smartwatch, used in our study, has acceptable energy efficiency in long-term monitoring and is able to collect reliable photoplethysmography data. Finally, we discuss the integration of the presented system with the current healthcare system.

The Effect of the EHD Pressure Spike on Rolling Bearing Fatigue

1987 ◽  
Vol 109 (3) ◽  
pp. 444-450 ◽  
Author(s):  
L. Houpert ◽  
E. Ioannides ◽  
J. C. Kuypers ◽  
J. Tripp
Keyword(s):  
Pressure Distribution ◽  
High Stress ◽  
Surface Damage ◽  
Rolling Bearing ◽  
Shear Stresses ◽  
Stress Concentrations ◽  
Surface Layers ◽  
Rolling Bearings ◽  
Life Model ◽  
Pressure Spike

A recently proposed fatigue life model for rolling bearings has been applied to the study of lifetime reduction under conditions conducive to microspalling. The presence of a spike in the EHD pressure distribution produces large shear stresses localized very close to the surface which may account for early failure. This paper describes a parametric study of the effect of such spikes. Accurate stress fields in the volume are calculated for simulated pressure spikes of different height, width and position relative to a Hertzian pressure distribution, as well as for different lubricant traction coefficients and film thicknesses. Despite the high stress concentrations in the surface layers, reductions in life predicted by the model are modest. Typically, the pressure spike may halve the life, with the implication that subsurface fatigue still dominates. In corroboration of this prediction, preliminary experimental work designed to reproduce microspalling conditions shows that microindents due to overrolling particles are a much more common form of surface damage than microspalling.

A New Shaft Coupling Design for a High-Speed Rotor Wheel

1995 ◽  
Author(s):  
Tibor Kiss ◽  
Wing-Fai Ng ◽  
Larry D. Mitchell
Keyword(s):  
High Speed ◽  
High Stress ◽  
Critical Issue ◽  
Working Environment ◽  
Outer Diameter ◽  
Stress Concentrations ◽  
Coupling Region ◽  
Rotor Wheel ◽  
High Stress Concentration ◽  
Safety Margins

Abstract A high-speed rotor wheel for a wind-tunnel experiment has been designed. The rotor wheel was similar to one in an axial turbine, except that slender bars replaced the blades. The main parameters of the rotor wheel were an outer diameter of 10“, a maximum rotational speed of 24,000 RPM and a maximum transferred torque of 64 lb-ft. Due to the working environment, the rotor had to be designed with high safety margins. The coupling of the rotor wheel with the shaft was found to be the most critical issue, because of the high stress concentration factors associated with the conventional coupling methods. The efforts to reduce the stress concentrations resulted in an advanced coupling design which is the main subject of the present paper. This new design was a special key coupling in which six dowel pins were used for keys. The key slots, now pin-grooves, were placed in bosses on the inner surface of the hub. The hub of the rotor wheel was relatively long, which allowed for applying the coupling near the end faces of the hub, that is, away from the highly loaded centerplane. The long hub resulted in low radial expansion in the coupling region. Therefore, solid contact between the shaft and the hub could be maintained for all working conditions. To develop and verify the design ideas, stress and deformation analyses were carried out using quasi-two-dimensional finite element models. An overall safety factor of 3.7 resulted. The rotor has been built and successfully accelerated over the design speed in a spin test pit.

scholarly journals Predicting Stress in Teens from Wearable Device Data Using Machine Learning Methods

2020 ◽  
Author(s):  
Claire W. Jin ◽  
Ame Osotsi ◽  
Zita Oravecz
Keyword(s):  
High Stress ◽  
Well Being ◽  
Physiological Signals ◽  
Support Vector ◽  
Stressful Event ◽  
Emotional States ◽  
Machine Model ◽  
Daily Lives ◽  
Physiological Indicators ◽  
Physiological Markers

AbstractStress management is a pervasive issue in the modern high schooler’s life. Despite many efforts to support adolescents’ mental well-being, teenagers often fail to recognize signs of high stress and anxiety until their emotions have escalated. Being able to identify early signs of these intense emotional states and predict their onset using physiological signals collected passively in real-time could help teenagers improve their awareness of their emotional well-being and take a more proactive approach to managing their emotions. To evaluate the potential of this approach, we collected data from high schoolers with Empatica E4 wearable health monitors (wristband) while they were living their daily lives. The data consisted of stressful event reports and physiological markers over the course of 4 weeks. We developed a random forest model and a support vector machine model and systematically assessed their performance in terms of predicting the onset of stress events and identifying physiological signals of stress. The models showed strong performance in terms of these measures and provided insights on physiological indicators of adolescent stress.

scholarly journals Is stress an important co morbid factor for hypertension among legal professionals

2018 ◽  
Vol 5 (5) ◽  
pp. 1899
Author(s):  
L. Kannan ◽  
Praveena P.
Keyword(s):  
High Stress ◽  
Simple Random Sampling ◽  
Well Being ◽  
Cross Sectional Study ◽  
District Court ◽  
Cross Sectional ◽  
Legal Professionals ◽  
The Difference ◽  
The Right ◽  
Study Participants

Background: Stress is a mental, physical and emotional response to life demands. Long hours of work, client demands, changing laws- creates stress and eventually hypertension among advocates. Well-being of the advocates are being questioned. Hence the main objective of the study is to evaluate the relationship between stress and hypertension among practising advocates.Methods: A cross-sectional study was conducted in a sample of 300 practising advocates at Madurai district court for a period of 1 year by simple random sampling method.Results: Around 133 (44.33%) and 167 (55.66%) of study participants were in level of high stress and low stress respectively. Among high stressed participants, a majority of 113 (84.96%) were found to be hypertensives and among the low stressed participants only 10 (5.98%) were hypertensives. The difference of observation was found to be statistically significant (p=0.0000).Conclusions: In conclusion the study explains that practising advocates with high perceived stress 113 (84.96%) were found to be hypertensives. Stress has a significant association with hypertension. The right way to manage stress is to implement coping strategies.

scholarly journals Well Being and Occupational Stress of Women Teachers of Primary Schools

2015 ◽  
Vol 2 (3) ◽  
Author(s):  
Dr. Utpal Kalita
Keyword(s):  
Elementary School Teachers ◽  
Occupational Stress ◽  
Primary Schools ◽  
High Stress ◽  
Well Being ◽  
Women Teachers ◽  
School Teachers ◽  
Stress Scale ◽  
High Stress Level

The elementary school teachers and especially women teachers are facing new challenges and need to be supported by the educational administrators and the state. In order to strengthen the role of women teachers, there is needed to look at well-being and occupation stress of women teachers‟. The present paper is justified to study the well being and occupational stress of women teachers of primary schools. For this, Well Being Scale and Occupational Stress Scale for are used as tools of data collection. Main findings of this study are: (i) very few women teachers fall in low well being level category while majority of the women teachers fall in the category of high well being, (ii) few women teachers fall in high stress level category while majority of the women teachers fall in the category of average as well as less stress well being category and (iii) there exists significant relationship between well being and occupational stress of women teachers of primary schools.

scholarly journals Prevalence of somatic symptoms amongst undergraduate medical students of Marathwada region of Maharashtra, India

2020 ◽  
Vol 7 (12) ◽  
pp. 5106
Author(s):  
Shaikh Arshiya Kaiser Husain ◽  
Anwaya R. Magare ◽  
Purushottam A. Giri ◽  
Vijaykumar S. Jadhav
Keyword(s):  
Medical Education ◽  
Medical Students ◽  
Medical Curriculum ◽  
High Stress ◽  
Well Being ◽  
Undergraduate Medical Students ◽  
Future Health ◽  
Cross Sectional ◽  
Significant Difference ◽  
Negative Effect

Background: The aim of medical education is to produce competent, physically and mentally strong health professionals, as they are going to be the pillars of the future health care system. Stress is one of the most common and process-oriented obstacles in medical education. It often exerts a negative effect on the academic performance, physical health, and psychological well-being of the students. Dealing with overloaded medical curriculum, competing with peers, being away from home and meeting high expectations imposed by parents and society to excel is among the common stressful transitions at this stage.Methods: A cross-sectional descriptive study was carried out amongst 352 undergraduate medical students of a private medical college in a rural area of Maharashtra during April to October 2019. The structured questionnaire was used to record the data. Collected data was used to assess the severity of mental health issues among medical students.Results: Majority 194 (55.11%) students were in the age of 18 to 20 years followed by 141 (40.06%) were in 21 to 23 years. There were 196 (55.68%) girl students and 156 (44.32%) boys. According to the various categories, 80 (22.73%) of the students had low stress scores, followed by 76 (21.59%) in minimal. A highly significant difference in stress scores was seen between boys and girls, which was more in boys.Conclusions: Study concluded that undergraduate medical students perceive minimal to very high stress presented as various systems that vary with the year of study and gender wise too. There is a further need to look into the various causes of stress.

Prevalence of problematic social media use among residents and teaching assistants in Ain Shams University Hospitals and faculty of medicine and its relationship to emotional distress

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
H Allam ◽  
G ELNahas ◽  
M El-Habiby ◽  
H Elkholy
Keyword(s):  
Social Media ◽  
Media Use ◽  
High Stress ◽  
Well Being ◽  
World Health ◽  
University Hospitals ◽  
Social Media Use ◽  
Cross Sectional ◽  
Stress Levels ◽  
Problematic Social Media Use

Abstract Background Social media use becomes pervasive and universal among young adults including medical personnel. Furthermore, it become established that more frequent use of the social media is associated with negative psychological well-being, anxiety which represents the second leading cause of disability among all psychiatric disorders and depression which represents the single largest contributor to global disability according to the World Health Organization. The Aim of this study To analyze the relationship between the use of social media, stress level, anxiety and depression among residents in Ain Shams University Hospitals (ASUH) and academic demonstrators in faculty of medicine. Patients and Methods This is an observational cross-sectional study, Conducted in Ain Shams University hospitals (ASUH), we included 200 of staff and medical school academics in faculty of medicine, starting from February 2018 till August 2019. Results 33 participants showed average social media use representing 16.5% while 167 participants showed problematic social media use representing 83.5%. 11 participants showed low stress levels representing 5.5%, 127 participants showed moderate stress levels representing 63.5% while 62 participants showed high stress levels representing 31%. Conclusion Social media use by clinicians is widespread, especially by younger clinicians for personal and reference purposes. Use of multiple SM platforms is independently associated with symptoms of depression and anxiety, even when controlling for overall time spent in their use.

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