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Introduction. Current studies support the implication of metabolic changes associated with type 2 diabetes in altering bone metabolism, structure and resistance.

For a ship, both synchronous and parametric roll motions can be modelled by nonlinear second-order differential equations with the roll angle as dependent variable and the nonlinearities coming from the damping and restoring moments. In the absence of exact solution techniques, approximate solutions for such equations can be obtained, in principle, analytically or numerically. In this paper, we focused on a fast and accurate recursive scheme based on the segmentation of the time domain into a fine grid of intervals of equal lengths. Due to the smallness of each time subinterval, a reset of the terms of the initial nonlinear equation of motion allows replacing it with a linear one in which the constant coefficients represent approximate values of the former variable coefficients in the middle of each subinterval. The linear equation is solved via the Laplace transform and the resulting solution together with its first derivatives is used to generate the iterative algorithm. This technique was applied to the case of two typical roll equations. The first describes the synchronous roll of a vehicle ferry model equipped or not with bilge keels while the second estimates the parametric roll of a container ship model. In both cases, the analyzed recursive algorithm not only generated results in full agreement with those provided by the ode45 solver in Matlab but also lead to a gain in computation time and offered more flexibility in imposing some restrictive conditions associated, for example, with exceeding some oscillation amplitudes or to the ship capsizing. [ABSTRACT FROM AUTHOR]

Turbine is a hydraulic engine where energy transfer occurs both based on the kinetic energy and potential (pressure) of the water. In this article we have designed the Spiral Turbine Casing - Impeller assembly with dimensions, geometry from technical documentation forms and the articles of other authors. CAD design of this assembly is a challenge and was done using. NX SIEMENS. The study of the fluid flow was done with ANSYS CFX by importing this assembly, some conclusions were drawn regarding the fluid velocities and the pressure field. The cavitation phenomenon that may occur in the operation of the turbine was also taken into account and some conclusions were drawn regarding the effects of this phenomenon. If the presence of vapours in the hydraulic circuit is found, then the cavitation can develop and this fact can be highlighted with Vapour Volume Fraction. [ABSTRACT FROM AUTHOR]

The reduction of ship roll motion is important in order to prevent damage to cargo, to allow the crew to work efficiently and to provide comfort for the passengers. There are passive devices like bilge keels or anti - roll tanks and active devices like gyrostabilizer and stabilizing fins which are commonly used to generate an opposed moment to the wave and wind excitation roll moments in response to the command of a control system. The paper presents numerical results of using a Proportional - Integral - Derivative (PID) controller for damping the roll motion of a fishing boat equipped with a fin stabilizer system and sailing in regular waves. The nonlinear roll equation, which includes B1 type damping and quantic restoring, besides the wave excitation moment and moment generated by fins, was linearized for relative small roll angles. The role of PID controller was to generate the corrective roll moment through the controlled fins in order to stabilize the roll motion. The thresholds for the controller's gains were determined using the Laplace transform and Routh - Hurwitz criterion. A simple but precise iterative scheme was used for the rapid integration of the system equations of motion in three cases: only proportional (P) component, proportional and derivative (PD) components and full PID controller. The numerical simulations have showed that all the analysed variants achieved roll reduction satisfactorily. [ABSTRACT FROM AUTHOR]

Parametric roll on ships is an auto-parametric resonance phenomenon whose onset causes a sudden rise in roll oscillations leading to dangerous situations for the ship, the cargo and the crew. In the paper, we have numerically investigated the effect of modifying the heading angle on the roll amplitudes. We followed three strategies. In the first, we allowed the heading angle to decrease with a constant angular acceleration so that the encounter frequency has left the dangerous region of the resonance. However, this option involves changing the course of the ship in the long run, which is of course a shortcoming. In the second strategy, we changed the heading angle up and down around an average value that generates large roll amplitudes, by using different periodic sinusoidal or triangular profiles. The beneficial effect of this action is to keep the course, even if at the cost of a momentary delay. We noticed that both control techniques listed above generally managed to significantly reduce the roll amplitudes if certain thresholds have been exceeded. As a last idea for decreasing the parametric roll amplitudes, we used the combined effect of ship forward speed and heading angle change. [ABSTRACT FROM AUTHOR]

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Copyright of Internal Medicine / Medicină Internă is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of this paper is to present the stages of designing a water in-line ejector used for ballast tanks stripping operation. The design operation was performed using NX Siemens CAD and ANSYS 15 for computer fluid dynamic analysis CFD. This ejector' design was based on descriptive drawings of component parts, all dimensions being chosen from a worldwide supplier of high quality marine products. Computer Fluid Dynamic analysis is based on the finite element method (FEM), meshing, boundary condition and loads. Finally, we reached important conclusions regarding velocities, pressure and temperature of the fluid. [ABSTRACT FROM AUTHOR]

Copyright of Internal Medicine / Medicină Internă is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)