Objective: To investigate the FRICTION of rabbit’s knee joint with designed pendulum FRICTION tester to diagnose and evaluate different pathological and therapeutic conditions following haemarthrosis, osteoarthritis, and other joint disorders. Materials and Methods: FRICTION coefficient of 10 adult male Albino rabbit’s joint (5 right and 5 left knees) weighted 1.59 ± 0.27 Kg, after designing and compiling the instrument and its processing software in the Physiotherapy department of Tarbiat Modares University were measured. Maximaum pendulum rotation, number of oscillations to reach equilibrium, coefficient of FRICTION with Stanton’s equation, exponential and linear curve fitting, average logarithmic and linear decrement methods were measured. Results: Maximum rotation after pendulum releasing in the left joints were higher than the right ones, P<0.001. Number of oscillations to reach equilibrium in the left knees were also greater than the right knees, P=0.005. All different FRICTION estimation methods had the same results and showed greater FRICTION in the right in comparison to the left side. Conclusion: The pattern of the joints amplitude decay did not have a linear behaviour and the rabbit’s knee joint coefficient of FRICTION with nonlinear estimations was less than linear ones. The findings revealed that selecting a separate control group in such investigation is essential and the contralateral limb could not be considered as control group. Pendulum FRICTION tester has the capability of evaluating changes in coefficient of FRICTION after application of different therapeutic methods. These changes have important role in diagnosis, evaluation of joint diseases and developing techniques for treating those pathologies.

When velocities in the piping systems change rapidly, spectacular accidents occur, due to transient-state pressures where the elastic properties of the pipe and liquid must be considered. This hydraulic transient is commonly known as water hammer. A conventional widely-used technique for analyzing this phenomenon is the Method Of Characteristic (MOC), in which, by introducing the characteristic lines, two ordinary differential equations, in lieu of the governing partial differential equations, are produced. In the undisturbed form of the equations, the energy dissipation is evaluated by the steady or quasi-steady approximation. But, there is experimental and theoretical evidence which shows that the velocity profiles in unsteady-flow conditions have greater gradients and, thus, greater shear stresses, than corresponding values in steady-flow. Moreover, the numerical integration of the FRICTION-loss is based on the values at the previous time step. This paper employs the External Energy Dissipator, Karney's method, to apply the boundary conditions in a network. To investigate the effect of the unsteady FRICTION formula, the cross characteristic mesh, based on the Vitkovsky formulation, is completely derived and incorporated in the network. At last, the effect of the weighting term in the integration of the FRICTION-loss term is examined. The paper shows that if the maximum head rise were to be practically considered, it would not need the unsteady FRICTION term to be taken into account. Moreover, the weighting integration constant has the slightest effect on the text network.

Double Concave FRICTION Pendulum (DCFP) bearing is a new generation of FRICTION isolator that contains two separate concave sliding surfaces with different properties. Accommodating enhanced performance, compared to the FRICTION Pendulum System (FPS), is one of the most important benefits of DCFP. Herein, the seismic behavior of structures isolated by DCFP bearings is compared with the response of the same buildings using the FPS bearing. Accordingly, a series of nonlinear dynamic analyses are carried out under ensembles of ground motions at three different hazard levels (SLE, DBE and MCE). Moreover, the adaptive behavior of DCFP and its advantages in protecting secondary systems is investigated. The probability of exceedance curves of peak roof acceleration, peak inter-story drift and peak isolator displacement is compared for two types of isolation system. The result supports the advantages of DCFP isolation systems.

Background & Aim: Increasing economic role of medicinal herbs in recent society and complexity of modern technologies in production (planting and harvesting), transportation, storage, processing, quality evaluation, distribution, marketing and consumption of these products require a thorough understanding of their physical properties. Coefficient of FRICTION of plant on the various surfaces is needed in designing of silos, storage of agricultural products and handling equipment, such as conveyors, and design of other equipment used in post harvest processing.Experimental: In this study, static coefficient of FRICTION for two values of water content (wet basis) 58% and 53% for rosemary and, 65% and 63% for lavender on three surfaces, galvanized steel, glass and wood was investigate. For this purpose an apparatus made that includes an electrical motor and an optical sensor for precise measurement of the slipping moment of the product and its coefficient of FRICTION.Results & discussion: Average values of maximum and minimum of static coefficient of FRICTION that obtained for rosemary at 58 percent of water content were 0.87 on the wood surface and 0.46 on the glass, respectively. While at 53 percent water content, the maximum and minimum average values of coefficient of static FRICTION obtained for rosemary were on wood, 0.66 and glass 0.38, respectively. The minimum average value of coefficient of FRICTION for the lavender at 65 percent water content was 0.66 and on the glass however after the reduction of water content, at 63 percent water content, obtained 0.56 on the glass, too.Industrial and practical recommendations: The understanding of the engineering properties of herbal drugs for creating appropriate industrial procreation methods is of great importance.