We consider the problem of a rigid surface moving over a flat plane. The surfaces are separated by a small gap filled by a lubricant fluid. The relative position of the surfaces is unknown except for the initial time t = 0. The total load applied over the upper surface is a know constant for t > 0. The mathematical model consists in a coupled system formed by Reynolds variational inequality for...

Gas flow heating using radio frequency plasmas offers the possibility of depositing power in the center of the flow rather than on the outside, as is the case with electro-thermal systems where thermal wall losses lower efficiency. Improved systems for space propulsion are one possible application and we have tested a prototype micro-thruster on a thrust balance in vacuum. For these initial tes...

The ability of gecko lizards to adhere to a vertical solid surface comes from their remarkable feet with aligned microscopic elastic hairs. By using carbon nanotube arrays that are dominated by a straight body segment but with curly entangled top, we have created gecko-foot-mimetic dry adhesives that show macroscopic adhesive forces of approximately 100 newtons per square centimeter, almost 10 ...

Studies were conducted to test the effect of age and food sources on wear of the mandibular teeth of the phytophagous pentatomid, Euschistus heros (F.). The total length (µm) of the area bearing the mandibular teeth, the length of the 1st tooth, and the height of the 2nd tooth for teneral (< 1 day-old) adults were significantly greater than that of adults fed on natural [green bean, Phaseolus v...

Manipulation of microorganisms with intrinsic motility is a challenging yet important task for many biological and biomedical applications. Currently, such a task has only been accomplished using optical tweezers, while at the risk of averse heating and photodamage of the biological samples. Here, we proposed a new micro-robotic approach for fluidic trapping and two-dimensional transportation o...

OBJECTIVE To determine whether there was any discrepancy in elbow flexion strength among patients with and without evident clinical deformity resulting from arthroscopic tenotomy on the long head of the biceps. METHOD A group of 120 patients who underwent this procedure were evaluated. After applying the exclusion criteria, 89 patients remained in the analysis. Eighteen months after the opera...

This paper presents results of a study conducted to estimate lower back loadings in cart pushing and pulling. Experiments were conducted in the laboratory using a cart. Six subjects with different weights (ranging from 50 to 80 kg) were tested for three different pushing and pulling forces (98, 196 and 294 newtons), three different heights of exertion (660, 1090 and 1520 mm high) and two differ...

Axial forces were applied between the shoulders and the skull of eight male Macaca mulatta monkeys. Forces from 556 to 1444 Newtons produced marked changes in blood pressure, heart rate and distraction of the cervical spinal column with minimal ligamentous disruption. Somatosensory evoked potentials recorded at the cortical and thalamic levels following dorsal column or peripheral nerve stimula...

Newton’s laws consist of “the law of inertia”, “the law of motion”, and “the law of action and reaction.” The first law depicts that if there is no external effect, an object must be still or moving at a constant velocity, which leads to a concept of the net force. The second law quantifies the force in terms of acceleration and mass of the object. The third law illustrates the existence of the...

Motivated by existing models used for soft body simulation which are rather complex to implement, we present a novel technique which is based on simple laws of physics and gives high quality results in real-time. We base the implementation on simple thermodynamics laws and use the Clausius-Clapeyron state equation for pressure calculation. In addition, this provides us with a pressure force tha...