There are several methods for analysing the behaviour of underground structures under different loading conditions. Most of these methods have many simplifications; therefore, in some cases, the results are too conservative and a very high safety factor, usually of more than 2 is needed. On the other hand, for stability analysis and the designing of support systems, these methods consider segme...

Brake fluid is a mixture of different Glycol derivatives which are poisoning and their ingestion triggers significant CNS symptoms, severe metabolic acidosis, cardiac, pulmonary, and renal failure. Here in this study, a case is reported who had been ingested 150mL of brake fluid for suicidal attempt.

The induced cracks on the concrete lining of the intake pressure tunnels may cause the water seep into the surrounding media leading to develop a hydro pressure on the external surface of the lining. In the common design practice, the lining can be designed to tolerate with this pressure using the Schleiss method. However, when the tunnel is constructed above the underground water, the seepage ...

According to the wide application of segmental lining in mechanized tunneling, recognizing the behavior of segmental lining joints is important in tunnels designing. In the structural analysis of the tunnel segmental lining, segmental joints can be considered as elastic joints, and their stiffness characteristics are affected by the rotational, shear, and axial stiffness. The purpose of this wo...

Passive haptic displays have several advantages when compared to active devices. Safety elements associated with active haptic displays may make them undesirable for certain applications. One method of actuation for passive haptic robots is through the use of brakes and clutches. Traditionally, friction brakes have undesirable behavior, such as stiction and delay in response time due to mechani...

the hydraulic pressure is one of the most important factors in the design of pressure intake tunnels. since the surrounding media cannot usually resist the high internal pressure of these tunnels, they are usually finished with an adequate lining mostly of reinforced concrete, which is an interaction problem between water, soil or rock and concrete lining. although reinforcing the concrete lini...

A tabletop waterwheel, designed and built by Prof. Willem Malkus (Math. Dept., MIT), is used to demonstrate chaos in a mechanical analog of the Lorenz equations. The waterwheel’s rotational damping rate can be adjusted by tightening or loosening a brake. When the brake is not too tight, the wheel settles into a steady rotation. Either direction of rotation is possible. When the brake was tighte...

The aim of the study was to create a model, describing the run of tribological processes in the surface layer of grey cast iron automotive brake discs. Grey cast iron discs mating with non-asbestos organic brake pads were chosen for the investigations, as the most widely used materials in car brakes. Samples for surface analysis were prepared from disc operating in stand and road conditions. St...