In the oil industry, the issue of controlling paraffin deposits remains relevant today. The most common way in the Perm Krai to remove paraffin is to lower the scrapers into the well.  This method is the main in the fight against paraffin deposits, but does not provide absolute protection. The least costly way to control paraffin is to use flushing with hot oil or water, but it does not always ...

Abstract. Given a doubling measure μ on R, it is a classical result of harmonic analysis that Calderón-Zygmund operators which are bounded in L(μ) are also of weak type (1, 1). Recently it has been shown that the same result holds if one substitutes the doubling condition on μ by a mild growth condition on μ. In this paper another proof of this result is given. The proof is very close in spirit...

A change in subtask order in the psychological refractory period (PRP) paradigm increases the effect of stimulus onset asynchrony (SOA) on the second response. We used a paradigm with cued, randomly determined subtask order to test the hypothesis that this SOA by order switch overadditivity reflects order control, via "copying" stimulus order. In Experiments 1a and 1b, overadditivity was eviden...

The artificial disc is a mobile implant for degenerative disc replacement that attempts to lessen the degeneration of the adjacent elements. However, inconsistent biomechanical results for the neighboring elements have been reported in a number of studies. The present study used finite element (FE) analysis to explore the biomechanical differences at the surgical and both adjacent levels follow...

Mitral valve replacement in the presence of extensive calcification of the mitral annulus is a technical challenge. Dense calcification of the annulus can cause a great difficulty in the insertion of a prosthetic valve and later periprosthetic leakage. A radical calcium debridement may cause left circumflex coronary artery injury, atrioventricular rupture, and thromboembolic events. We report a...

The Ross procedure is an alternative technique to mechanical prosthesis and recent evidence suggests that it is associated with improved long-term survival and quality of life. However, late pulmonary autograft failure can occur more frequently in patients with significant dilation of the aortic annulus. Here, we present a technical modification of the Ross procedure--a case report of a patient...

OBJECTIVE To assess the influence of the pulmonary annulus diameter after reconstruction of the right ventricular (RV) outflow tract at repair of tetralogy of Fallot on pulmonary regurgitation and RV pressure load; and to evaluate the impact of pulmonary regurgitation on RV size and function. SETTING Paediatric cardiology and diagnostic radiology departments of a tertiary referral centre. P...