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Power Screws, Fasteners, and Connections
Published in Ansel C. Ugural, Mechanical Engineering Design, 2022
The spring constant of clamped parts is seldom easy to ascertain and frequently approximated by employing an empirical procedure. Accordingly, the stress induced in the joint is assumed to be uniform throughout a region surrounding the bolt hole [8]. The region is often represented by a double-cone-shaped barrel geometry of a half-apex angle 30°, as depicted in Figure 15.14. The stress is taken to be 0 outside the region. The effective cross-sectional area Ap is equal to about the average area of the shaded section shown in the figure: Ap=π4[(dw−d22)2−d2]
Power Screws, Fasteners, and Connections
Published in Ansel C. Ugural, Youngjin Chung, Errol A. Ugural, Mechanical Engineering Design, 2020
Ansel C. Ugural, Youngjin Chung, Errol A. Ugural
The spring constant of clamped parts is seldom easy to ascertain and frequently approximated by employing an empirical procedure. Accordingly, the stress induced in the joint is assumed to be uniform throughout a region surrounding the bolt hole [8]. The region is often represented by a double-cone-shaped barrel geometry of a half-apex angle 30°, as depicted in Figure 15.14. The stress is taken to be 0 outside the region. The effective cross-sectional area Ap is equal to about the average area of the shaded section shown in the figure: Ap=π4[(dw−d22)2−d2]
Power Screws, Fasteners, and Connections
Published in Ansel C. Ugural, Youngjin Chung, Errol A. Ugural, MECHANICAL DESIGN of Machine Components, 2018
Ansel C. Ugural, Youngjin Chung, Errol A. Ugural
The spring constant of clamped parts is seldom easy to ascertain and frequently approximated by employing an empirical procedure. Accordingly, the stress induced in the joint is assumed to be uniform throughout a region surrounding the bolt hole [11,12]. The region is often represented by a double-cone-shaped barrel geometry of a half-apex angle 30°, as depicted in Figure 15.14. The stress is taken to be 0 outside the region. The effective cross-sectional area Ap is equal to about the average area of the shaded section shown in the figure: Ap =π4[(dw+d22)2−d2]
Non-equivalent notions of the eccentricity of the conics: an exploratory study with high school teachers
Published in International Journal of Mathematical Education in Science and Technology, 2023
Antonio Rivera-Figueroa, Ernesto Bravo-Díaz
In this third approach, the conics are the curves in the three-dimensional space obtained by slicing a fixed infinite right circular double cone with a variable inclined plane that does not pass through the cone's vertex. In this definition, elements of the curves such as centre, foci, or directrix are not involved. Every plane perpendicular to the axis of the double cone will be called a horizontal plane. The name of conics (or conic sections) comes precisely from the conception of these curves in three-dimensional space. For a given double cone, these curves are classified by the inclined plane's inclination and position (Figure 3). If the inclined plane is horizontal, the curve obtained is a circle. If the inclined plane is parallel to a cone's generatrix, the plane will intersect only one nappe of the cone, and the curve is called a parabola. Suppose the inclined plane is neither horizontal nor parallel to a generatrix. Then an ellipse or a hyperbola is obtained, depending on whether the plane intersects only one nappe of the cone or intersects both nappes. The hyperbola is a curve that consists of two branches, one on each nappe. The eccentricity is not involved in these definitions of the curves but appears in the context of a proposition, established and proven by Germinal Pierre Dandelin (see, e.g. Brannan et al., 2012, p. 22; Simmons, 1996, pp. 551–552) in this proposition the concept of directrix is introduced.
Evaluation of laboratory accuracy of forehead radiation thermometers using blackbody sources for tympanic thermometers defined by international standards with adaptors
Published in Journal of Medical Engineering & Technology, 2023
Two reference blackbody sources are used for the test. One is an ear thermometer calibration blackbody source manufactured by Chino Corporation (Chino) following Japanese standard JIS T 4207:2005 [4]. The source has a double cone shape of cavity with an opening of 12 mm. The cavity is immersed in a temperature-controlled water bath. The source has an indicated temperature of the water bath but we use an additional standard platinum thermometer (SPRT) to measure the bath temperature independently. The second reference blackbody source (NMC made) is similar to the first one but with difference cavity design [5]. The cavity is cone ended with 350 mm in depth and an opening of 45 mm. Similarly to the first one, the cavity is immersed in a temperature-controlled bath and the bath temperature is measured by a SPRT. The emissivity of both cavities is higher than 0.999. We have evaluated the two reference blackbody sources and confirmed that they are equivalent in calibration of ear thermometers.
Corticospinal and intracortical excitability is modulated in the knee extensors after acute strength training
Published in Journal of Sports Sciences, 2022
Razie J Alibazi, Ashlyn K Frazer, Alan J Pearce, Jamie Tallent, Janne Avela, Dawson J Kidgell
Single- and paired-pulse TMS was delivered over the M1 via a concave double-cone coil using a Magstim 2002 magnetic stimulator (Magstim Co., Ltd, Whitland, UK). The junction of the double-cone coil was placed 1–2 cm left of the vertex and oriented to induce posterior-to-anterior cortical current flow. Sites near the estimated centre of the rectus femoris area (motor hotspot) were explored to determine the sites at which the largest MEP amplitude was evoked and active motor threshold (AMT) was established as the intensity at which at least 5 of 10 stimuli produced MEP amplitudes of greater than 200 µV (Kidgell et al., 2010) during a low-level isometric contraction. After the single session of strength training, AMT was retested and adjusted if required. To ensure all stimuli were delivered to the optimal motor hotspot throughout testing, the position of the coil was marked.