Search results for "Drill"

A method for rapid implantation of multielectrode systems.

1991

The implantation of several chronic electrodes at the same time was needed for the studies in which both evoked slow potential and multiple unit neural activity of different brain sites were recorded during classical conditioning in freely moving cats. The recording electrodes were made of 25-75 microns insulated stainless steel or nichrome wires which were inserted into a thin hypodermic needle of a fixed, calibrated length. The fast implantation system described here is based on the use of a stereotaxic frame as a stand for a drill and as a support for an electrode holder with which the electrodes were implanted through precision holes drilled directly according to the coordinates of the …

Cine, deporte y propaganda. De "Olympia" al simulacro.

2016

RESUMEN TESIS Este trabajo rastrea y analiza las continuidades entre las herramientas propagandísticas del fascismo y los recursos comunicativos del capitalismo. Se aborda desde la perspectiva del deporte y en el caso concreto del cine olímpico, con una perspectiva histórica de 80 años que trata de elegir los mejores ejemplos del género y los momentos puntuales de cambio. El deporte se considera aquí punto de encuentro entre la política, la historia, la sociedad y la economía y se aborda desde la comunicación, considerando el cine olímpico como ejemplo cerrado, internacional y referencial. Se analiza el relato cinematográfico de los Juegos Olímpicos de Los Ángeles de 1984 (“16 days of glory…

Identifying sedimentary structures and spatial distribution of tsunami deposits with GPR - examples from Spain and Greece

2011

Shallow drilling in coastal areas like southern Spain and different parts of Greece (Corinth region and Argolis Gulf) proved evidence for tsunamis. Sedimentary analyses were conducted to identify tsunamigenic deposits, but did not reveal sedimentary structures or spatial distribution of tsunamites in a regional scale. Since drilling is time-intensive and expensive (depending on extend), this method can by far not cover an entire coastal area. On the other hand, distribution and preservation of tsunamigenic deposits seems to be highly variable. We used ground penetrating radar (GPR) in combination with electrical resistivity tomography (ERT) measurements and sedimentological research methods…

Considerations on sand control in natural gas wells

2017

Mechanism of sand production in gas wells is complex and influenced by every operation performed into the well, starting from the opening of the production interval by drilling, and continuing with completion and putting into production as well as with the exploitation regime. Sand production along with fluids from gas reservoirs creates a series of potentially dangerous and costly problems. For selecting the most appropriate methods of sand-control all the data and information related to properties of reservoir rock, the history of sand production, the potential well flow rates as well as HSE and costs need to be evaluated. The conclusion of the authors is that the best results in sand con…

A Recent Advancement: Casing while Drilling – A Viable Alternative to Conventional Drilling

2021

Mankind’s increased requirement for and dependence on energy resources, including the resources resulting from discovery and development of new hydrocarbon commercial reservoirs involves the use of new technologies such as optimization of the drilling process by reducing the non-productive time, the costs and the risks. Casing while drilling involves elimination of classical drilling string by using the casing string both for transmission to the bit of the mechanical energy and for circulation of drilling fluid into the well. Casing while drilling, constantly improving over time, has proven an efficient method to reduce risks, especially those related to the presence of a conventional…

Casing while Drilling – a Viable Alternative to Conventional Drilling

2019

Mankind’s increased requirement for and dependence on energy resources, including the resources resulting from discovery and development of new hydrocarbon commercial reservoirs involves the use of new technologies such as optimization of the drilling process by reducing the non-productive time, the costs and the risks. Casing while drilling involves elimination of classical drilling string by using the casing string both for transmission to the bit of the mechanical energy and for circulation of drilling fluid into the well. Although there is a number of technical or perception barriers related to the use of casing drilling, the important benefits of this technology related to reduced dril…

Analysis of factors determining thermal changes at osteotomy site in dental implant placement - An in-vitro study

2021

Background Heat generation during osteotomy site preparation is a crucial factor that determines the success of dental implant placement. Among the factors that affect the heat generation, drilling speed, hand pressure and coolant temperature are independent variables. However, a relation between these three parameters and their optimal values required for the maximum outcome has not been studied so far. This study aims at finding out a relation between these factors in order to derive the optimum balance required, using an in vitro study. Material and methods This in vitro experiment was performed on bovine femur. A total of 72 drillings were undertaken with the aid of a physiodispenser mo…

RODRÍGUEZ ESTEBAN, María Ascensión. "La arquitectura de ladrillo y su construcción en la ciudad de Zamora (1888-1931)"

2016

Dependence between aging treatments and residual stresses on composite laminate

2006

International audience; The objective of this paper is to study the influence of residual stresses due to fabrication conditions on the thermomechanical behavior of carbon/epoxy laminate structures (cross ply). These studied laminates have undergone various cycles of thermal aging. The addition of a post-cure cycle after the end of the initial cycle makes it possible to reduce the residual stresses level. The incremental hole-drilling method is used to measure the residual strain in the laminates. These measured strains and the numerical calibration coefficients obtained by the finite element method allow to calculating the residual stress distribution in composite depth. The obtained resul…

Optimization of depth increment distribution in the ring-core method

1996

The integral equation method is the most suitable calculation procedure for the determination of non-uniform residual stresses by semi-destructive mechanical methods such as hole and ring-core drilling. However, the high sensitivity to strain measurement errors due to the ill-conditioning of the equation sets has prevented its practical use. Examination of the influence of the strain measurement error on the calculated stresses and its propagation has shown that, for given maximum groove depth and total steps number, the error sensitivity depends on the particular depth increment distribution used. By means of an alternative matrix formulation of the equation sets the depth increment distr…