BACKGROUND Background: Patch tests are an efficient method to confirm the etiological diagnosis of allergic contact dermatitis. OBJECTIVES 1) To determine the permanence of results between two tests performed with an interval of at least one year, in patients with allergic contact dermatitis; 2) To compare the positive results according to rates of intensity; 3) To evaluate the permanence of ...

BACKGROUND Cosmetic products contribute considerably to the incidence of contact dermatitis. In response to a resolution of the Council of Europe, the National Institute for Public Health and the Environment (RIVM) in The Netherlands set up a pilot project to report undesirable effects attributed to cosmetic products. OBJECTIVES To provide an overview of undesirable effects attributed to cosm...

This paper illustrates the use of the envelope theorem for the geometric design of a cycloidal speed reducer. Specifically, it proposes two designs for a mathematical model with tooth differences: a pin wheel epitrochoid meshing which is a cycloidal wheel (internal rotor) profile equidistant to an epitrochoid (or extended epicycloid) curve and a cycloida! wheel is generated by a pin wheel (exte...

This paper presents a comprehensive wheel model that can quantitatively evaluate traction performance of flexible/rigid wheels driving on deformable terrain. The proposed model exploits a terramechanics-based approach with taking account of pressures generated by wheel elasticity as well as terrain stiffness. Deflection of a flexible wheel typically depends on a relative pressure between the wh...

The article presents the methodologies based on multi-body systems used to analyze the dynamics of rail vehicle in motion in a straight line. Study of the railway vehicles dynamics requires the creation of three mutually independent models: the model of the vehicle, the track model and a model of the wheel – rail contact. A railway vehicle model developed in the multi-body systems convention w ...

Wheels are very important for the safety of a train. The diameter of the wheel is a significant parameter that needs regular inspection. Traditional methods only use the contact points of the wheel tread to fit the rolling round. However, the wheel tread is easily influenced by peeling or scraping. Meanwhile, the circle fitting algorithm is sensitive to noise when only three points are used. Th...

Future robotic vehicles will perform challenging tasks in rough terrain, such as planetary exploration and military missions. Rovers with actively articulated suspensions can improve rough-terrain mobility by repositioning their center of mass. This paper presents a method to control actively articulated suspensions to enhance rover tipover stability. A stability metric is defined using a quasi...

The effect of the discontinuity of the rail ends and the presence of lower modulus insulation material at the gap to the variations of stresses in the insulated rail joint (IRJ) is presented. A three-dimensional wheel – rail contact model in the finite element framework is used for the analysis. It is shown that the maximum stress occurs in the subsurface of the railhead when the wheel contact ...