Various Angles Of Inclination Research Articles

Proximal humeral anatomy in shoulder arthroplasty: Implications for prosthetic design and surgical technique

Resurfacing arthroplasty of the glenohumeral joint has been established for several decades as a means to restore comfort and function of the shoulder for many afflictions that derange the normal anatomy. Rigorous study of shoulder anatomy in terms relevant to prosthetic geometry, however, did not begin until the 1990s. It has become apparent that normal anatomy is highly variable from individual to individual and that it is aligned somewhat differently than the early modular prosthetic devices. Multiple studies have shown that retroversion is markedly variable, not only between individuals but also between the left and right sides of the same individual, ranging from 0 degrees to 55 degrees . The inclination of the proximal humeral articular surface relative to the shaft (head shaft angle) is also variable, ranging from 30 degrees to 55 degrees. The center of rotation is variably offset in 3 dimensions. The radius of curvature ranges from 20 to 30 mm and is smaller in women than in men. The thickness of the articular surface, head height, is equally variable but shows a striking proportionality to the radius of curvature. The last decade has seen a proliferation of humeral implants aiming to serve a better understanding of shoulder anatomy and function. A modern understanding of shoulder anatomy and contemporary design features is paramount for surgeons performing shoulder arthroplasty. Head size selection is dependent on multiple factors, the most important of these, other than the patient's original head size, are the osteotomy performed by the surgeon and the inclination angle(s) of the prosthetic system. Systems with variable inclination angles instruct the surgeon to resect the humeral head along the anatomic neck as best possible and then provide either adjustable or variable prosthetic geometries to match the resultant inclination angle. Other prosthetic systems have a fixed inclination angle somewhere within the normal range and instruct the surgeon to make an osteotomy at this inclination, adjusting the fit with additional preparation of the canal and revising the osteotomy as necessary. Over the last decade, most systems have offered heads that are offset by 3 to 4 mm, allowing the surgeon to dial in the most suitable position for the head on the stem. Component design and surgical technique are inextricably intertwined. Most surgeons with experience using modern systems feel a greater sense of predictability in achieving their surgical goals when using these systems as compared with earlier ones. How these developments impact implant longevity will only be known with time and further follow-up.

The Rotation Curves of Dwarf Galaxies: A Problem for Cold Dark Matter?

We address the issue of accuracy in recovering density profiles from observations of rotation curves of galaxies. We observe and analyze our models in much the same way as observers do the real galaxies. Our models include stellar disks, disks with bars, and small bulges. We find that the tilted-ring model analysis produces an underestimate of the central rotational velocity. In some cases the galaxy halo density profile seems to have a flat core, while in reality it does not. We identify three effects that explain the systematic biases: inclination, small bulge, and bar. Inclination effects are due to the finite thickness of the disk, bar, or bulge. Admixture of a nonrotating bulge component reduces the rotational velocity. A small (200-500 pc) bulge may be overlooked, leading to systematic bias even on relatively large (~1 kpc) distances. In the case of a disk with a bar, the underestimate of the circular velocity is larger because of a combination of noncircular motions and random velocities. The effect of the bar depends on the angle that the bar makes with the line of sight. Signatures of bars can be difficult to detect in the surface brightness profiles of the model galaxies. The variations of inclination angle and isophote position angle with radius are more reliable indicators of bar presence than the surface brightness profiles. The systematic biases in the central ~1 kpc of galaxies are not large. Each effect separately gives typically a few km s-1 error, but the effects add up. In some cases the error in circular velocity was a factor of 2, but typically we get about a 20% effect. The result is the false inference that the density profile of the halo flattens in the central parts. Our observations of real galaxies show that for a large fraction of galaxies the velocity of gas rotation (as measured by emission lines) is very close to the rotation of the stellar component (as measured by absorption lines). This implies that the systematic effects discussed in this paper are also applicable both for the stars and emission-line gas.

NUMERICAL STUDY OF LAMINAR NATURAL CONVECTION IN INCLINED RECTANGULAR ENCLOSURES OF VARIOUS ASPECT RATIOS

Numerical investigations are conducted for free convective laminar flow of a fluid with or without internal heat generation in rectangular enclosures of different aspect ratios and at various angles of inclination. Two principal parameters for this problem are the external Rayleigh number, Ra E , which represents the effect due to the differential heating of the side walls, and the internal Rayleigh number, Ra I , which represents the strength of the internal heat generation. Results are obtained for a fixed external Rayleigh number, Ra E =2 2 10 5 , with internal Rayleigh number, Ra I =0 (without internal heat generation), and also with Ra I =2 2 10 5 (with internal heat generation). Flow patterns and isotherms do not show any significant difference between the cases with and without internal heat generation other than slight shift and changes in stream function and isotherm values as long as the internal Rayleigh number Ra I is less than or equal to the external Rayleigh number Ra E . Local heat flux ratios along the hot and the cold walls decrease monotonically in the flow direction for a major downstream portion. At certain inclinations the local heat flux ratios increase initially and then decrease. The variation of average heat flux ratio is similar for cases with and without internal heat generation, but the corresponding amount of heat transfer is higher through the hot wall and lower through the cold wall with internal heat generation. On the other hand, the convection strength increases as the enclosure shape changes from slender through square to shallow at any particular inclination, but varies mildly with inclination at a particular aspect ratio.

NUMERICAL STUDY OF TURBULENT NATURAL CONVECTION IN A SIDE-HEATED SQUARE CAVITYAT VARIOUS ANGLES OF INCLINATION

Turbulent natural convection at a moderately high Rayleigh number (4.9 2 10 10 ) in a two-dimensional side-heated square cavity at various angles of inclination is studied numerically. Initially, the performance of the low Reynolds number k - y model of Wilcox (1994) and the low Reynolds number k m l turbulence model of Lam and Bremhorst (1981), in predicting buoyancy-driven flow in a noninclined enclosure, is evaluated against experimental measurements. The evaluation is focused on the prediction of the flow patterns and convective heat transfer in the boundary layer and corner regions. The performance of the Wilcox k m y model is found to be superior in capturing the flow physics such as the strong streamline curvature in the corner regions. The Lam and Bremhorst k m l model is not capable of predicting these features but provides reasonable predictions away from the corners. None of these models, however, is capable of predicting the boundary-layer transition from laminar to turbulent. In order to study the effect of the inclination of the square cavity on the heat transfer and flow patterns, computations are then performed using the Wilcox k m y model for a range of inclination angles from 0° through 90°, keeping other parameters fixed. The computed flow patterns, isotherms, convection strengths, variation of the local Nusselt numbers along the heated walls, and the average Nusselt number for various inclination angles of the square cavity are reported. It is noticed that the flow fields and heat transfer characteristics become significantly different for inclinations greater than45°. The computational procedure is based on finite-volume collocated mesh. The pressure-velocity coupling in the governing equations is achieved using the well-known SIMPLE method for numerical computation. The linear algebraic system of equations is solved sequentially using the strongly implicit procedure (SIP).

ボールエンドミル切削における切りくず生成状態と切削抵抗の予測 第１報 球体部の切れ刃形状と切削模型

Cutting edge of a sphere portion (end cutting edge) of the ball end mills is treated as the intersection of a spherical surface and a rake face approximated by a plane surface. The cutting edge configuration is geometrically analyzed, and variation of inclination angle and normal rake angle along the cutting edge is discussed. In addition, it is assumed that the line elements along the curved cutting edge of the sphere portion do not undergo extension or contraction, and the modified condition of side-curl of the chip is introduced. Then a cutting model and energy method developed for the drilling process is extended to the milling process. Expressions such as area of the shear plane and projected area of the cutting cross-section on the rake face are derived for slot milling. From the analytical results obtained through energy method, it is found that the center of side-curl of the chip is fixed near the top of the sphere portion of ball end mills and the chip is produced under this restricted condition. Furthermore, predicted result shows that Stabler's chip flow rule does not hold for the milling with ball end mills.

Lapping of Single Crystal Diamond Tools

Lapping is the key technology used in manufacturing process of diamond tools and diamond Jewels. Because of the strong anisotropism and super hardness of diamond, the material removal rate is very small in its lapping process. The Influence of the crystal anisotropism on removal rate in diamond lapping is discussed in this paper. A new diamond crystal orientation method by using laser diffraction is presented, which can not only be used for the crystal orientation, but also for the indication of ‘soft’ directions on crystal planes in lapping. The mechanism of removal rate anisotropism in diamond lapping is investigated, and a new explanation for the reasons is proposed. It is pointed out that the variation of inclination angle between Inside (111) plane (cleavage plane) and lapping surface causes the difference of friction coefficient and removal rate in diamond lapping. Furthermore, a new method using ultrasonic vibration for diamond lapping was developed to improve the removal rate.

Orientation Effects on Critical Heat Flux due to Flooding in Thin Rectangular Channel

Forced convective critical heat flux (CHF) in a rectangular channel that depended on an inclination angle was investigated. The experiment has been performed with a one side-heated thin rectangular channel under the atmospheric pressure with the inclination angle varying from 10° to 90° and mass flux from 0 to 400 kg/m2·s. The CHF was found to decrease with the inclination angle remarkably at low mass flux. Flooding CHF analysis was carried out based on the result of flow visualization in the channel, and the incorporation of inclination angle into a model was proposed. A comparison of the model prediction with experimental results showed good agreement between the measured and predicted CHF with varying inclination angle. The model was combined with a conventional CHF correlation for evaluation of mass flux, and finally a forced convective CHF correlation for an inclined thin rectangular channel was proposed.

A methodology for investigating the effect of a south oriented surface on natural illuminance received on north oriented glazing of a top lighting system under clear sky conditions

A methodology for investigating the effect of a south oriented surface with varying inclination angle in reflecting natural light towards a north oriented glazing of a top lighting system is proposed for use under clear sky conditions. This was done based on mathematical simulation for a top lighting system. Results have shown the importance of the reflective surface in increasing the illuminance received on the glazing of the top lighting system.

Orientation Effects on Critical Heat Flux due to Flooding in Thin Rectangular Channel.

Forced convective critical heat flux (CHF) in a rectangular channel that depended on an inclination angle was investigated. The experiment has been performed with a one side-heated thin rectangular channel under the atmospheric pressure with the inclination angle varying from 10° to 90° and mass flux from 0 to 400 kg/m2·s. The CHF was found to decrease with the inclination angle remarkably at low mass flux. Flooding CHF analysis was carried out based on the result of flow visualization in the channel, and the incorporation of inclination angle into a model was proposed. A comparison of the model prediction with experimental results showed good agreement between the measured and predicted CHF with varying inclination angle. The model was combined with a conventional CHF correlation for evaluation of mass flux, and finally a forced convective CHF correlation for an inclined thin rectangular channel was proposed.

Influence of experimental parameters on the erosive–corrosive wear of Al–SiC particle composite

The performance of an Al-alloy-based composite reinforced with 10 wt.% SiC particle in erosive–corrosive slurry environment was examined. The slurry consists of equiaxed sand particles of varying proportion (20, 40 and 60 wt.%) of size approximately 100 μm and solution of water, sulphuric acid and hydrochloric acid. The specimens were placed at various angles of inclination (0°, 45° and 90°) with respect to the direction of rotation of the specimens and at different radial distances (35, 55 and 75 mm) in order to assess the effect of these parameters on erosion–corrosion characteristics of composite. It was observed that wear rates increase drastically with increasing angle of inclination, sand concentration in the slurry, and radial distance. However, it was noticed that the wear rate remains unchanged when the specimen tested in a slurry containing more than 40 wt.% sand and the same become significantly less when the specimen is placed at a radial distance less than 55 mm. Scanning electron microscopic (SEM) study confirms that wear of composite is mainly governed by the synergic effect of the two simultaneous processes: (i) erosion, corrosion and abrasion of the matrix by the slurry; and (ii) fracture and removal of the dispersoid due to particle impingement at high speed. This study also revealed that wear rate at any condition increases to a maximum and then is reduced with the distance traversed. This might be due to work hardening of the specimen surface.

Effects of gas slugs and inclination angle on the ultrafiltration flux in tubular membrane module

The permeate fluxes of an inclined gas-slugs ultrafiltration system were measured and discussed under various gas–liquid flow ratios and inclination angles. The experiments were carried out in a tubular ceramic membrane module by using dextran T500 aqueous solution as the tested solution. In the single liquid-phase ultrafiltration system or the gas–liquid two-phase ultrafiltration system with turbulent liquid flow, the variation of inclination angle affects the permeate flux slightly. In the gas–liquid two-phase ultrafiltration system with laminar liquid flow, the permeate flux is enhanced significantly as the inclination of the ultrafiltration column increases up to a certain angle. The optimal inclination angle of the ultrafiltration column is about 53° in present experimental system. The enhancement in flux is due to the combination effects of natural convection and forced convection induced by the slug flow in the inclined tubular membrane.

Spiral Incremental Forging Process for Preforming of Turbine Blades with Axis Bending Control by Varying Inclination Angle of Tool.

For suppression of remarkable bending of a blade axis caused in preforming of the turbine blades with complicated shapes using incremental forging, an effective method is proposed in which metal flow during forging is controlled by varying inclination angles of tools to a billet axis. The effect of the inclination angle of tool and the specific twisting angle on the bending of the blade axis is mainly investigated by carrying out forming tests of plasticine blades with inclined flat tools. The bending of the blade axis is reduced with an increase in the specific twisting angle. The optimum inclination angle of tool, at which the bending of the blade axis is minimized, exists and depends on the specific twisting angle. The complexly curved surface of the blade can be roughly generated using the proposed method.

Diffraction of low-energy electrons at a rippled surface

An analysis is made of a kinematic model of the scattering of low-energy electrons at a onedimensional periodic toothed structure simulating a rippled surface. Calculations of the intensity profiles of the diffraction peaks are made for periodic systems of identical symmetrical triangular teeth with a variable number of atoms on each generatrix of the tooth and various angles of inclination of the generatrices to the horizontal. The main effect observed as a result of scattering at a periodic toothed structure involves broadening or splitting of the diffraction peaks compared with the diffraction patterns from a smooth chain of atoms.

EFFECTS OF BOND NUMBERS ON INTERNAL FLOW PATTERNS OF AN INCLINED, CLOSED, TWO-PHASE THERMOSYPHON AT NORMAL OPERATING CONDITIONS

A visual study of internal flow patterns inside an inclined, closed, two-phase thermosyphon at normal operating conditions for several Bond numbers has been conducted. This article describes the effects of varying inclination angles and Bond numbers (Bo) onflow patterns, A copper thermosyphon was used. R123 was selected as the working fluid, with a vapor temperature of 30°C and a filling ratio of 50%. Flow phenomena were observed at selected inclination angles of 90° and 30° from the horizontal axis, with aspect ratios of 30 and 5. The selected external diameters were 12.0 and 28.5 mm. Flow phenomena were also recorded with a standard video camera and a still camera, and the corresponding heat transfer rates were also monitored. It was observed that the basic internal flow patterns could be classified according to the aspect ratios and the Bo as follows: At an aspect ratio of 10 and higher, the annular flow at vertical changes to slug flow in inclined positions for all values of Bo. A thin liquid film always exists in the upper part, promoting heat transfer. In this case, the ratio of heat transfer rates at peak position and those of the vertical (Q / Q90) are almost the same for all Bo. At an aspect ratio of less than 10 and a low Bo, bubbly flow at vertical changes to stratified flow at an inclined position, with bubbly flow in the lower part. Vapor slug is sometimes seen. At an aspect ratio of less than 10 and a high Bo, bubbly flow with a coagulation of bubbles at the vertical position changes to stratified flow with bubbly flow in the upper part, without any vapor slugs. Q / Q90 is comparatively higher than at lower Bo. This result may be attributed to two main factors: (1) there was an area undisturbed by bubbles in the lower part; and (2) no upward vapor slug movement was observed.

The heart muscle’s putative ‘secondary structure’. Functional implications of a band-like anisotropy

Opinions are divided as to whether the rope-like secondary structure, which Torrent-Guasp dissected out of the myocardial body by the blunt unwinding technique (BUT) reveals some kind of functional compartmentation of the heart muscle. The myocardial fibres are aligned parallel to the fibre disruption (cleavage) plane, along which the band has been prepared but they are not necessarily aligned parallel to the long axis of the band. Inconsistencies in the myocardial rope model arise from the obligatory zones of transmural inflection, which are obvious in the base and the apex of both ventricles. They are, however, merely discernible in the midzone of the left ventricular cone. The investigator experienced in BUT knows that the cleavage plane is not unique. We doubt the assumption that the rope structure is the predominant stress transmission pathway, because the fibre strand peel-off technique (SPOT) delivers irregular fibre disruption planes which are definitely different from those which Torrent-Guasp prepares. The rope-like fibre arrangement could be just a redundant structure, a remnant of past developmental steps without, however, any functional implication to the human heart. On the other hand, peeling-off fibre strands from the ventricular wall produces deeply perforating, i.e., oblique transmurally grooved surfaces. Putative functions of force transmission in an oblique transmural direction are (1) ventricular dilation as a function of the variable inclination angle with respect to the epicardial surface, (2) monitoring of ventricular wall stress and ventricular size and (3) segmental stiffening which could serve other dependent segments as a punctum fixum.

Stress Intensity Factors of Double and Multiple Edge Cracks

In this paper stress intensity factors of double and multiple edge cracks in a semi-infinite plate is considered. The problem is considered by solving a system of hypersingular integral equations based on the body force method. First, two edge cracks A and B having different crack lengths and inclination angles are analyzed and the effect of crack B upon crack A is investigated. Then, stress intensity factor(SIF) of crack A is found to be almost constant independent of the wide variation of inclination angle B if the crack tip B is fixed. Second, periodic edge cracks are systematically analyzed with varying the number, distance and angle of cracks. Then the interaction effect is found to appear mostly from the distances of crack tip independent of the angle. Numerical results are also shown when crack parameters are slightly changed from average values in almost equally spaced multiple edge cracks.

Experimental Study on Aerodynamic Noise Generated from Two-Dimensional Models. 2nd Report. Effect of the Angle of Inclination of Circular Cylinders and the Angle of Attack of Square Cylinders to Aerodynamic Noise.

Control of the aerodynamic noise generated from two-dimensional circular and square cylinders are studied experimentally in a low noise wind tunnel. The circular cylinder of 1cm diameter is inclined against the mean flow, whereas the square cylinder of 1cm2 cross section is placed normal to the mean flow, with various angles of attack. Mean velocity of the flow is between 20.6m/s and 41.6m/s. Powere spectra of the radiated noise in various angles of inclination or angles of attack are measured in order to examine the changes in peak levels and the Strouhal numbers of the so-called Aeolian tones. For the circular cylinder, it is found that the Strouhal number based on the frequency of the Aeolian tone and the normal component of the mean velocity to the axis of the circular cylinder stays nearly constant for the angle between 0° and 45°. The peak level of the radiated noise decreases rapidly from the inclined angle from 0° to 15°. but it stays nearly constant for the angle over 15°. For the square cylinder, the Strouhal number is smallest and the peak level is highest at the angle of attack of 0°. The peak level decreases and the Strouhal number increases rapidly with increase of angle of attack up to 13°. For the angle above 15°, both the Strouhal number and the peak level stay almost constant. It is concluded that a circular cylinder should be inclined more than 15°. and a square cylinder should have an angle of attack well over 15° in order to reduce aerodynamic noise generation.

An Analytical Model for Fluted Sunspots and a New Interpretation of Evershed Flow and X-Ray Anemones

view Abstract Citations (19) References (33) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS An Analytical Model for Fluted Sunspots and a New Interpretation of Evershed Flow and X-Ray Anemones Martens, Petrus C. H. ; Hurlburt, Neal E. ; Title, Alan M. ; Acton, Loren W. Abstract We present a force-free constant-α model for the magnetic field in and above so-called "fluted" sunspots. This model is motivated by recent high-resolution observations of Title et al. at the Swedish Solar Observatory in La Palma. They observed that the inclination angle of the magnetic field in the penumbra of sunspots oscillates rapidly with azimuth, with a period of about 60 and an amplitude of about 18°. They further find that there is little variation in the radial direction and in absolute field strength. The resulting phenomenon of interlocking high- and low-inclination field lines was called "flutedness. In our model, the parameters are chosen to reproduce the La Palma magnetograms, and an analytical expression is obtained for the three-dimensional magnetic field emanating from the sunspot's umbra and penumbra. The model correctly reproduces the azimuthal variation in inclination angle, as well as the mean constancy of the magnetic field strength, and the appearance of a highly corrugated neutral line on the limb side of off-center sunspots. We find that the "flutedness" results in a highly complex topology in a boundary layer extending from the photo sphere into the chromosphere, while the coronal field is uniform. Title et al. demonstrated that the Evershed flow occurs in regions of nearly horizontal magnetic field, and tacitly assumed, as is done in most of the literature, that the dark filaments in which the flow is observed form individual magnetic flux tubes. Our magnetic field solution suggests that the regions of nearly horizontal field at the photo spheric boundary may not form individual magnetic flux tubes, but rather a series of short horizontal loops bridging a neutral line that is stretched in the radial direction along the penumbra, up to the outer penumbral boundary. Hence, the Evershed flow could not be a simple siphon flow in the radial direction, but would consist of phase-coordinated flows along the many short loops bridging the neutral line. However, the assumption of a force-free field breaks down in this region of the atmosphere, and the topology suggested by it may not materialize in reality. We further demonstrate that there are large variations in the photospheric cross sections of coronal loops, due to the complexity of the field near their photospheric footpoints. Under the assumption of constant energy input per unit surface area into these loops, the variation in cross section is qualitatively consistent with the variation in X-ray brightness of loops in penumbral "anemones" observed by Yohkoh. Publication: The Astrophysical Journal Pub Date: May 1996 DOI: 10.1086/177251 Bibcode: 1996ApJ...463..372M Keywords: MAGNETOHYDRODYNAMICS: MHD; SUN: MAGNETIC FIELDS; SUN: X-RAYS; GAMMA RAYS; SUN: SUNSPOTS full text sources ADS |

The viscous resuspension of particles in an inclined rectangular fracture

It has recently been observed that in laminar shear flows settled particles within a suspension can be resuspended. This phenomena, known as “viscous resuspension”, if properly exploited can have a beneficial effect on the process of proppant placement within a hydraulic fracture. By taking advantage of viscous resuspension effects it is possible to entrain particles from a settled bed back into the bulk shear flow which will enable them to be convected deep into the fracture channel and thus avoid the possibility of fracture closure. In practice the sedimentation/resuspension processes usually consist of rigid spherical negatively buoyant particles, which are of approximately equal size and density and do not aggregate, settling at very small particle Reynolds numbers from a suspension comprised of an incompressible Newtonian fluid. In this paper the particle concentration equation is solved initially for a fully developed steady one-dimensional gravity-driven flow down an inclined channel. The problem is then developed by adding a pressure-driven flow across the inclined channel. The concentration, momentum and conservation of mass equations have been solved numerically under a wide variety of operating conditions and initial feed particle concentrations, and typical concentration and velocity profiles at various angles of inclination of the channel and strengths of cross flow are presented.

Analysis of an arbitrarily inclined slot on the ground plane of a microstrip line

The analysis of an arbitrarily inclined slot on the ground plane of a microstrip line is presented using the spectral domain approach and reciprocity theorem. Comparison of numerical results for the special case of a perpendicular slot with other available computed and measured data shows a good agreement. It is found that the impedance level can be controlled over a wide range by varying inclination angle. Results should be useful in antenna and multilayer circuit integration applications.