BACKGROUND Various techniques for quadriceps tendon repair have been described with biomechanical studies suggesting greater failure threshold with longitudinally placed drill holes. 1 The current gold standard for repair uses 3–4 sutures 2 passed through parallel longitudinal transpatel-lar bone tunnels. We describe a simple and reproducible technique Figure 1 Acufex ® Director™ Drill Guide po...

We present a data exploration system equipped with smart drill-down, a novel operator for interactively exploring a relational table to discover and summarize "interesting" groups of tuples. Each such group of tuples is represented by a rule. For instance, the rule (a, b, ★, 1000) tells us that there are a thousand tuples with value a in the first column and b in the second column (and any valu...

OBJECTIVE Postoperative headache is an undesirable consequence of retrosigmoid vestibular schwannoma (VS) removal. An ultrasonic bone aspirator (UBA) may reduce headache by minimizing subarachnoid bone dust dispersion. The feasibility of removing internal auditory canal (IAC) bone with a UBA is unknown. This study assessed volume and duration of IAC bone removal in clinical and laboratory setti...

Severe environment in deep ocean affects operating reliability and security of coring drill. Adopting heave motion signal measured by accelerometer to confirm heave compensation of coring drill, the compensation control method is proposed using disturbance observer to restrain the disturbance. Then, the disturbance observer is designed. The heave motion simulation for coring drill is done with ...

All structures have modal properties such as natural frequencies and damping. In engineering it is often of interest to estimate these modal properties for certain structures, to be used when modelling for example fatigue. This is done by computing them from nite element models, by using experimental measurements or both. In the case of doing both, a nite element model is usually established rs...

Due to the lower tool as the research object to analyze the vibration of the drill string, causes the loss of the low order natural frequency of the drill string and the inherent vibration mode, give rise to the distortion and error of the result from the transient analysis of the drill string. For this purpose, the whole drill string of the deep wells is studied in the article, build the mecha...

In rotary drilling operation, the hydraulic circuit typically consists of stand pipe, rotary hose, swivel, Kelly, drill pipe, drill collar, drill bit, and the annulus between the drillstring and the open hole or the casing. Stand Pipe Pressure, abbreviated as SPP, is defined as the total frictional pressure drop in the hydraulic circuit. SPP, an important drilling parameter in selecting proper ...

In automation flexible manufacturing systems, tool wear detection during the cutting process is one of the most important considerations. This study presents an intelligent system for online tool condition monitoring in drilling process .In this paper, analytical and empirical models have been used to predict the thrust and cutting forces on the lip and chisel edges of a new drill. Also an empi...

A key element to verify the drill-bit signal processing is the estimation of the time delay of the guided waves transmitted through the drill string from the bit to the surface. This delay can be measured from drill-bit vibrations or calculated using the mechanical properties of the drill string. The calculation of the complete solution and the exact dispersion relations requires expensive nume...