Measuring and modelling towline responses using GPS aided inertial navigation

The offshore towage of large floating structures has been the broad subject of research since the 1960’s. The selection of a tug to engage in a tow is based on rules laid down by class and marine warranty surveyors derived from years of experience but a rigorous assessment of these rules based on a comprehensive real world datasets has not been possible. This is principally due to the nature of these tows, usually employing tugs chartered at short notice from the spot market, the long towline lengths when under tow and the high value of the tow itself. Given the commercial implications in being able to better match a suitable tug to any given tow, this research lays down the requirements of an ideal dataset, i.e. one that has a record of towline tensions, complete 6DOF of both the tug and tow all recorded to a universal timeline, along with the seastate experienced by the tow at any given point. It then reviews the historical restrictions in gathering this data and that the key issue has been gathering the motions of the unpowered tow and recording the towline tensions.A methodology is then developed which requires no interference with the towline and draws upon Kalman filters for optimal state estimation of the tug and tow’s position and attitude in 3D space driving a lumped mass simulation of the towline coded in MatLab. The stiffness properties of key elements of the towline are assessed by FEA and observations made on areas where normal industry practice’s may be lacking. Observations on advances in sensor technology as well as other areas for development are then made that provide fertile areas for further research. Finally the full code base for a MatLab, lumped mass simulator is presented in an appendix for future use.The offshore towage of large floating structures has been the broad subject of research since the 1960’s. The selection of a tug to engage in a tow is based on rules laid down by class and marine warranty surveyors derived from years of experience but a rigorous assessment of these rules based on a comprehensive real world datasets has not been possible. This is principally due to the nature of these tows, usually employing tugs chartered at short notice from the spot market, the long towline lengths when under tow and the high value of the tow itself. Given the commercial implications in being able to better match a suitable tug to any given tow, this research lays down the requirements of an ideal dataset, i.e. one that has a record of towline tensions, complete 6DOF of both the tug and tow all recorded to a universal timeline, along with the seastate experienced by the tow at any given point. It then reviews the historical restrictions in gathering this data and that the key issue has been gathering the motions of the unpowered tow and recording the towline tensions.A methodology is then developed which requires no interference with the towline and draws upon Kalman filters for optimal state estimation of the tug and tow’s position and attitude in 3D space driving a lumped mass simulation of the towline coded in MatLab. The stiffness properties of key elements of the towline are assessed by FEA and observations made on areas where normal industry practice’s may be lacking. Observations on advances in sensor technology as well as other areas for development are then made that provide fertile areas for further research. Finally the full code base for a MatLab, lumped mass simulator is presented in an appendix for future use

A randomised crossover trial comparing Thai and Swedish massage for fatigue and depleted energy

Background: The aim of this study was to compare the efficacy and social constructions of Thai massage (TM) and Swedish massage (SM) for patients experiencing fatigue or depleted energy. Method: Twenty participants were randomised to receive three once-weekly TM treatments and three once-weekly SM treatments, with crossover after three massages. Symptom checklists were administered at three time points and included Activation-Deactivation Adjective Check List and VAS Scale. Qualitative data were collected through semi-structured interviews and participants’ diary entries. Results: Both massage types enhanced physical, emotional and mental wellbeing through improved sleep, relaxation, relief of stress and relief of muscular tension. TM alone showed specific energising and psychological stimulation results, along with carry-over effect and longer lasting benefits. Ninety-five percent of participants found relief from their initial reason presenting symptoms. Conclusion: TM or SM can relieve symptoms of fatigue or low energy by releasing stress, promoting relaxation, relieving muscular aches and pains and improving energy. SM results in a larger effect in relaxation and improved sleep whereas TM results in a larger effect in energising, rejuvenating and mentally stimulating effects

Isolation and primary cultures of human intrahepatic bile ductular epithelium

A technique for the isolation of human intrahepatic bile ductular epithelium, and the establishment of primary cultures using a serum- and growth-factor-supplemented medium combined with a connective tissue substrata is described. Initial cell isolates and monolayer cultures display phenotypic characteristics of biliary epithelial cells (low molecular weight prekeratin positive; albumin, alphafetoprotein, and Factor VIII-related antigen negative). Ultrastructural features of the cultured cells show cell polarization with surface microvilli, numerous interepithelial junctional complexes and cytoplasmic intermediate prekeratin filaments. © 1988 Tissue Culture Association, Inc