The response of a combined dynamic system consisting of a Spar, a mooring line system, and top tension risers is presented. The top tension of a riser is provided by a buoyancy can that is laterally supported by a preloaded compliant guide. The overall system is nonlinear due to the mooring line restoring force, the friction between the buoyancy cans and the compliant guides, and the friction between the risers and the guides at the Spar keel. The friction between the Spar and the riser system is captured by a Coulomb model, whereas the stiffness of the mooring line system is accounted for by using a regression analysis of pertinent load versus displacement data. The combined model is numerically integrated using input time histories of force and moment that are compatible with a random representation (Jonswap spectrum) of a typical extreme environmental loading in the Gulf of Mexico. The input time histories of the force and the moment for the combined model are obtained at the center of gravity of the Spar by using a standard motion analysis program (MLTSIM). The numerical results of the time domain analysis of the combined model, in conjunction with ergodicity, are used for an associated Monte Carlo study. The Monte Carlo study provides useful information regarding the probability densities and the power spectra of various response components of the combined system. These results serve as a benchmark for additional analytical studies that use the technique of statistical linearization to derive equivalent linear stiffness and damping coefficients for the combined system.
The COVID-19 pandemic originated from Wuhan, China, spread around the world with horror and dramatic loss of human life. The economic and social catastrophe has made it even more irresistible. An attempt has been made to find out what kind of psychological and livelihood-related impacts Covid-19 has had on our daily lives. Data had been collected through convenient online surveys where 344 respondents were interviewed. Most of the respondents reported the reduction of movement, income and working hours. The majority reported a noticeable decrease in sleep, health condition and body weight due to the increase of tension where some tensed more. Corona can be avoided by drinking hot water and tea, this idea had increased the amount of hot water and tea consumed by the common people. Many of those who lost their jobs were distressed and others also were distressed at the thought of how long they would stay. The most frightening thing was that the addiction to the virtual world had increased dramatically.
BackgroundRehabilitation has been an integral part of management of COPD. Since the implementation of the standard rehabilitation protocol is hardly possible in the rural developing world, aiming to make a feasible alternate effort may be worthwhile.MethodsCOPD patients diagnosed through spirometry were first stabilized with 6 weeks of uniform pharmacotherapy. Subsequently, they were subjected to a curriculum-based intensive single-session intervention with education, bronchial hygiene, and exercise training. The latter involved whole body exercise, pursed lip breathing, and diaphragmatic exercise. The participants continued to practice the exercises under real-world encouragement and supervision from trained volunteers. The impact was appraised in terms of change in health status through COPD assessment test (CAT) score measurements at stabilization, and after 6 weeks and 1 year of the intensive training and education.ResultsAt stabilization, 70 out of 96 selected COPD subjects (73%) turned up (with mean age 62±9 years and mean FEV1 as 1.16±0.39 L) showing improvement as per CAT score (p=0.0001) from pharmacotherapy. After practicing the imparted education and training for 6 weeks, all these 70 participants had further significant improvement in the health status (n=70, p=0.00001). This improvement, been reinforced and supervised, continued to last even at 1 year (n=54, p=0.0001).ConclusionThe self-managed practice of a single-session education and training under real-world supervision can bring forth significant long-term improvement in the health status of COPD sufferers. Such simple and feasible intervention may substitute formal COPD rehabilitation programs in resource constraint situations.
The response of a combined dynamic system consisting of a Spar, a mooring line system, and top tension risers is presented. The top tension of a riser is provided by a buoyancy-can that is laterally supported by a preloaded compliant guide. The overall system is nonlinear due to the mooring line restoring force, the friction between the buoyancy-cans and the compliant guides, and the friction between the risers and the guides at the Spar keel. The friction between the Spar and the riser system is captured by a Coulomb model, whereas the stiffness of the mooring line system is accounted for by using a nonlinear regression analysis of pertinent load versus displacement data. The combined model is numerically integrated using input time histories of force and moment that are compatible with a random representation (Jonswap spectrum) of a typical extreme environmental loading in the Gulf of Mexico. The input time histories of the force and the moment for the combined model are obtained at the center of gravity of the Spar by using a standard motion analysis program (MLTSIM). The numerical results of the time domain analysis of the combined model, in conjunction with ergodicity, are used for an associated Monte Carlo study. The Monte Carlo study provides useful information regarding the probability densities and the power spectra of various response components of the combined system. These results serve as a benchmark for additional analytical studies that call attention to the potential usefulness of the technique of statistical linearization for efficient dynamic analyses of preliminary design decisions regarding the combined Spar–Risers–Mooring lines system.
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