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...

Fluoroscopy is currently the standard approach for image guidance of surgical drilling procedures. In addition to the harmful radiation dose to the patient and surgeon, fluoroscopy fails to visualize critical structures such as blood vessels and nerves within the drill path. Photoacoustic imaging is a well-suited imaging method to visualize these structures and it does not require harmful ioniz...

OBJECTIVES To investigate whether a surgeon can drill accurately a specified angle and whether surgeon experience, task repetition, drill bit size and perceived difficulty influence drilling angle accuracy. METHODS The sample population consisted of final-year students (n=25), non-specialist veterinarians (n=22) and board-certified orthopaedic surgeons (n=8). Each participant drilled a hole t...

Abstract Accurate pressure drop estimation is important for drill string and bit nozzles design optimized fluid circulations as well identifying the drilling problems such nozzle(s) washout or plugging. In this study, Bingham Plastic model has been modified by applying a coefficient to its turbulent loss calculations. This encompasses effects of pipe tool joints other in losses. The range was d...

Jajarm Alumina Plant, the only Alumina powder producer in Iran, generates 500,000 tons of red mud annually. The commonest method for final disposal of red mud in Iran is Tailing dam which is neither cost-effective nor environmentally-friendly. The main objective of this study is to evaluate the possibility of red mud recovery to be used for stabilization of loose soils. Red mud samples have bee...

Jajarm Alumina Plant, the only Alumina powder producer in Iran, generates 500,000 tons of red mud annually. The commonest method for final disposal of red mud in Iran is Tailing dam which is neither cost-effective nor environmentally-friendly. The main objective of this study is to evaluate the possibility of red mud recovery to be used for stabilization of loose soils. Red mud samples have bee...

Formation temperature is an important parameter in geothermal drilling since it affects drilling fluid, operations and equipment, through mud temperatures. In this study formation temperatures of the five geothermal wells in Germencik-Omerbeyli field were estimated by using mud inlet and outlet temperatures obtained during drilling. GTEMP wellbore thermal simulation model was used to estimate t...

the increasing needs for energy, its high price and its environmental impact on greenhouse gases emission and limited energy resources due to increased research on energy balance in crop production systems. the objective of this research was to compare seedbed preparation and sowing methods in wheat production in kordkoy region with respect to energy use and efficiency. fifteen wheat fields wer...

The present paper offers a numerical model which can be applied for the simulation of wave height distribution on a 2-D horizontal soft mud layer. The model is based on mild slope equations and it includes combined wave refraction, diffraction, reflection and breaking. The high energy dissipation of wave height due to the presence of fluid mud layer has also been simulated. Wave height attenuat...

BACKGROUND Heat therapy is one of the most popular non-pharmacological treatments for osteoarthritis of the hand. OBJECTIVES To investigate the therapeutic and chemical effects of Hévíz mud on patients with hand osteoarthritis. METHODS We randomly assigned 47 patients with mild-to-moderate hand osteoarthritis to two groups. Patients in group 1 (n=23) received Hévíz mud applied directly to b...