The GPS errors can be separated into a frequency-dependent or dispersive component (e.g. the ionospheric delay) and a non-dispersive component (e.g. the tropospheric delay and orbit biases). Dispersive and nondispersive errors have different dynamic effects on the GPS network corrections. The former exhibit rapid changes with high variations due to the effect of free electrons in the ionosphere...

Shoulder arthroscopy offers a minimally invasive surgical approach to treat a variety of shoulder pathologies. The patient can be positioned in either the lateral decubitus or the beach chair position. This note and accompanying video describe the operating room setup for shoulder arthroscopy in the lateral decubitus position, including positioning of the arms, head, and sterile preparation and...

Introduction: The gamma cameras, based on scintillation crystal followed by an array of photomultiplier tubes (PMTs), play a crucial role in nuclear medicine. The use of square PMTs provides the minimum dead zones in the camera. The camera with square PMTs also reduces the number of PMTs relative to the detection area. Introduction of a positioning algorithm to improve the spat...

background and aims: to obtain maximum advantages from orthodontic fixed appliances and to achieve the desired final occlusion, correct bracket positioning is highly necessary. in order to measure and determine bracket’s height, diverse gauges have been used. the objective of the present study is to determine and compare bracket positioning accuracy by using height bracket positioning gauge (hb...