Axial Surface Research Articles

Deformation Law of Cold Drawing Process of High Strength Bridge Cable Steel

High-strength cable-steel bridge is the “lifeline” of steel structure bridges, which requires high comprehensive mechanical properties, and cold-drawing is the most important process to produce high-strength cable-steel bridge. Therefore, through the ABAQUS platform, a bridge wire drawing model was established, and the simulation analysis on the process of stress strain law and strain path trends for high-strength bridge steel wire from Φ 12.65 mm by seven cold-drawing to Φ 6.90 mm was conducted. The simulation results show that the wire drawing the heart of the main axial deformation, surface and sub-surface of the main axial and radial deformation occurred, with the increase in the number of drawing the road, the overall deformation of the wire was also more obvious non-uniformity. In the single-pass drawing process, the change in the potential relationship of each layer of material was small, and multiple inflection points appeared in the strain path diagram; the change in the seven-pass potential relationship was more drastic, which can basically be regarded as a simple superposition of multiple single-pass pulls.

Anatomical Study of Some Species of the Brassicaceae Family

Study complete in postgraduate laboratories at the College of Science, Department of Biology, University of Kufa. The anatomical study revealed a variation in the formation of complex cells and epidermal cells, where they differed in their shapes and were irregular with wavy ridges and on the axial surfaces in R. sativusvar red L. and R. sativuslongipinntus L. Their walls were weak jagged in only R. raphenstrum. Also, the stomata were located on both sides of the leaf blade, and the upper epidermis contained fewer stomata compared to the lower epidermis.

Influence of weathering on surface roughness of thermally modified wood

Wood is one of the most important building materials. Thermally modified wood is entering the market and replacing wood preservatives and tropical wood species in some applications. Thermally modified wood is exposed to weathering similarly as other wood-based building materials. It has been reported that if thermally modified wood is exposed to weathering, its moisture performance might decrease fairly fast. Moisture performance reflects the material’s ability to remain dry and dry out fast when wet. The aim of this study was to determine whether this phenomenon is associated with crack formation or roughness. Norway spruce, thermally modified spruce, wax-treated thermally modified spruce, and European larch heartwood samples were exposed to artificial accelerated weathering and natural weathering for 9, 18, and 27 months. Samples were subsequently isolated, and their roughness was determined with a confocal laser scanning microscope on axial and longitudinal surfaces at 10× and 50× magnification. After weathering, roughness increased on both axial and longitudinal surfaces. This was evident from the profile 2D measurements (Ra) and surface 3D measurements (Sa). The effect of natural weathering on roughness was higher than artificial accelerated weathering, presumably due to synergistic effects of abiotic and biotic factors. This may be associated with Wenzel’s theory on the influence of roughness on the contact angles of water on the surface; namely, increased roughness will decrease the contact angle on hydrophilic surfaces.

Real-Time Geometric Glint Anti-Aliasing with Normal Map Filtering

Real-time geometric specular anti-aliasing is required when using a low number of pixel samples and high-frequency specular lobes. Several methods have been proposed for mono-lobe bidirectional reflection distribution functions (BRDFs), but none for multi-lobe BRDFs, e.g., a glinty BRDF. We present the first method for real-time geometric glint anti-aliasing (GGAA). It eliminates most of the inconsistent appearing and disappearing of glints on surfaces with significant curvatures during animations. The technique uses the glinty BRDF of Chermain et al. [2020] and leverages hardware GPU-filtering of textures to filter slope distributions on the fly. We also improve this glinty BRDF by adding a correlation factor of slope. This BRDF parameter allows convergence to normal distribution functions that are not aligned on the surface's axes. Above all, this parameter makes glint rendering compatible with normal map filtering using LEAN mapping. Using GGAA increases the rendering time from 0.6 % to 4.2 % and it requires 1/3 more memory due to MIP mapping of tabulated slope distributions. The results are compared with references using a thousand samples per pixel.

Ultrasonic-assisted friction drilling process of aerospace aluminum alloy (AA7075): FEA and experimental study

Joining sheets and plates in the industry is of high importance. In the automotive and aerospace industry, using friction drilling technique is developing. In order to improve this method, different techniques have been used. In this research, applying ultrasonic vibration on the tool will be investigated. In this regard, a special tool was designed. Axial force and surface hardness were measured in friction drilling and ultrasonic assisted friction drilling. Higher rotational speed and lower feed rate induce lower axial force and higher surface hardness. In addition, ultrasonic vibration causes the surface to be harder with lower axial force. The results show that increasing the rotational speed and decreasing the feed rate in lathe machine causes axial force reduction and surface hardness increase in heat affect zone and thermomechanical region. Moreover, finite element method was carried out which indicated lower axial force occurs in ultrasonic assisted friction drilling comparing to conventional condition. Equivalent plastic strain was used to examine hardness value numerically. The obtained numerical and experiment results were in good agreement.

Prediction of multiple origin overpressure in deep fold-thrust belt: A case study of Kuqa subbasin, Tarim Basin, northwestern China

The accurate prediction of overpressure before drilling is important for hydrocarbon exploration. It is almost impossible to directly predict the multiple origin overpressures via the existing methods that are related to anomalous porosity in a deep fold-thrust belt. Considering the Kelasu thrust belt (KTB) as an example, the compacting and loading curves in the KTB at the maximum burial period were restored. The measurements of fluid pressure obtained from drill-stem tests carried out at depth were then used to calculate the vertical effective stress offset (ΔVES) away from the restored loading curve. The unknown ΔVES was then predicted using the quantitative relationship between ΔVES, the distance from the axial surface of the fold forelimb or the distance to the thrust fault cutoff (FDIST), and the erosion thickness (ΔH). Finally, the vertical effective stress and overpressure were predicted using the predicted ΔVES, overburden stress, and loading curve. We found that mudstones formed at different rates of deposition would have different loading curves, which is a piecewise function that alternates between convex and concave functions. The convex function is more suitable for describing the loading and compaction behavior of strata with limited porosity strata ( 3.5%) can be better expressed by the concave function. The ΔVES induced by tectonic compression, transfer, and exhumation was found to present an inverse relationship with the FDIST but showed a positive relationship with the ΔH. Compared to Eaton’s method, the method developed in this study produces more accurate results and is, therefore, more appropriate for predicting the overpressure of intense tectonic compression, faulting, and exhumation fields in deep fold-thrust belts.

Structure of the Golets Vysochaishy gold deposit (Northern Transbaikalia)

The article describes the fold-thrust structure of the Golets Vysochaishy deposit located at the Baikal-Patom Upland in the Marakan-Tunguska megasyncline. The latter is composed of terrigenous-carbonate carbonaceous rocks metamorphosed in greenschist facies conditions. The deposit is detected in the hanging wing of the asymmetric Kamenskaya anticline. In a cross section, the anticline is an S-shaped structure extending in the latitudinal direction. The main feature of the Golets Vysochaishy deposit is the development of interlayer sulfidization zones (pyrite, pyrrhotite), including gold-bearing ones. Its gold-ore zones tend to occur in layered areas of interlayer sliding in the rocks of the Khomolkhinskaya suite.Four structural markers revealed within the deposit area are indicative of repeated deformation processes: (1) sublatitudinal folding, cleavage of the axial surface and its subsequent transformation into schistosity; (2) crenulation cleavage; (3) interlayer sliding and rock breakdown with interlayer drag folds, parallel microfractures and polished slickensides; (4) large quartz veins and veinlets that cross cut the main structural elements in plan.

Structural styles, deformation, and uplift of the Olympic Mountains, Washington: Implications for accretionary wedge deformation

Abstract The Olympic subduction complex is the exposed subaerial Cascadia accretionary wedge in the Olympic Mountains of Washington State. Uplift of the mountains has been attributed to two competing models: margin-normal deformation from frontal accretion and underplating, and margin-parallel deformation from the clockwise rotation and northward movement of the Oregon Coast Range block compressing the Olympic Mountains block against the Canadian Coast Range. East-northeast–oriented folds and Quaternary thrust faults and paleostress analysis of faults in the Coastal Olympic subduction complex, west of the subduction complex massif, provide new evidence for north-south shortening in the Coastal Olympic subduction complex that fills a large spatial gap in the north-south shortening documented in prior studies, substantially strengthening the block rotation model. These new data, together with previous studies that document north-south shortening in the subduction complex and at numerous locations in the Coast Range terrane peripheral to the complex, indicate that margin-parallel deformation of the Cascadia forearc has contributed significantly to uplift of the Olympic Mountains. Coastal Olympic subduction complex shallow-level fold structural style and deformation mechanisms provide a template for analyzing folding processes in other accretionary wedges. Similar-shaped folds in shallow-level Miocene turbidite sediments of the Coastal Olympic subduction complex formed in two shortening phases not previously recognized in accretionary wedges. Folds began forming by bed-parallel flow of sediment into developing hinges. When the strata could no longer accommodate shortening by flexural flow, further shortening was taken up by flexural slip. Similar-shaped folds in the deeper accretionary wedge rocks of the subduction complex massif have a well-developed axial-surface cleavage that facilitated shear folding with sediment moving parallel to the axial surface into the hinges, a structural style that is common to accretionary wedges. The pressure-temperature conditions and depth at which the formation of similar folds transitions from bed-parallel to axial-surface–parallel deformation are bracketed.

Accuracy of recording edentulous jaw relations by using an optical jaw tracking system: An in vitro study.

To establish a recording method for edentulous jaw relations and to perform quantitative accuracy evaluation in vitro. Maxillary and mandibular edentulous arch models and complete dentures were mounted on an articulator, simulating protrusion (A), left and right laterotrusion (B and C), and small opening jaw relations (D), aided by metal foil wax record. Using the tracking system, 3D trajectories of targets were recorded from intercuspation to A, B, C, and D, then used to rehabilitate digital arch relations of A, B, C, and D in the test group. Axial model surfaces were pasted with six pairs of positioning cylinders. The center points of the bottom surfaces of the cylinders in A, B, C, and D were measured to rehabilitate digital arch relations in the control group. With the maxilla as the common area, arch relations of the test group were registered in the control group; 3D deviations of the mandible were calculated, and displacements in horizontal left/right, horizontal anterior/posterior, and vertical directions were analyzed. 3D deviations of the mandible in A, B, C, and D were 131 ± 39 μm, 133 ± 44 μm, 120 ± 51 μm, and 112 ± 52 μm, respectively. Mean absolute values of displacements of the mandible were less than 200 μm. By using the optical jaw tracking system, the accuracy of jaw relation records as measured on an articulator was acceptable for clinical demand. Further investigations among patients are required to clinically verify the results of this study.

Analysis of acoustic, entropy and vorticity waves in a non-uniform annular combustor

Annular ducts with axial cross-sectional surface area gradient are typical elements in aero-engines and land-use gas turbines. Acoustic, entropy and vorticity waves propagating in these regions are generally coupled and may affect the thermoacoustic instabilities. However, due to the highly coupled mechanism, there has been no analytical solutions; the numerical solutions of typical linearized Euler equations (LEEs) cannot clearly identify the contributions from the coupled three waves. This work presents two asymptotic methods to isolate the acoustic, entropy and vorticity waves coupled in these kinds of annular ducts. These methods are validated by comparing their predicted results to those numerically resolving the LEEs. Further analyses are conducted in a model annular combustor. Results show that the interaction among the three waves cannot be neglected in the combustion with a large inlet Mach number flow. The interaction between acoustic and vorticity waves is stronger than that between acoustic and entropy waves. Also, this work shows that the entropy noise and the vortex noise have similar mechanisms.

Bond Strength and Microleakage of Different Designs of Occlusal Veeners

The purpose of this study was to investigate fracture strength of different lithium disilicate occlusal veneers designs with different tooth preparations. Material and method: Fifty-six extracted human mandibular molars were collected with relatively comparable size and standardization done by diamond saw and it will receive. 6mm lithium disilicate occlusal veneers. Specimens will be divided into two main groups, each of these groups contains 28 samples (group A&B), the first group represents occlusal veneers with 1.0 ml with radial shoulder finish line design includes axial surfaces for a2 ml length, while the second group represents occlusal veneers preparation without finish line. Each main group will be subdivided into 2 subtypes groups (A1, A2, B1, B2), each subtype group contains 14 samples, the first subtype group will receive a buccal groove, while the second subgroup will be without grooves. Each subgroup will be divided into 2 classes (7 samples) according to the type of test it will be subjected to: microleakage, bond strength. Results: The fracture strength is (mean value+ standard deviation) in plain occlusal reduction without vs with buccal groove(890.36±42.51N), (865.69±36.79N). The fracture strength is (mean value ± standard deviation) in occlusal reduction with radial shoulder, without or with buccal groove (835.36±42.51N), (820.69±36.79N), with nonsignificant difference p value <0.05. Conclusions: All tested occlusal veneer designs proved to withstand normal and parafunctional masticatory forces with non-significant statistical difference.

Development of an intra-carbonate detachment during thrusting: The variable influence of pressure solution on deformation style, Khao Khwang Fold and Thrust Belt, Thailand

Abstract Classic detachment zones in fold and thrust belts are generally defined by a weak lithology (typically salt or shale), often accompanied by high over-pressures. This study describes an atypical detachment that occurs entirely within a relatively strong Permian carbonate lithology, deformed during the Triassic Indosinian orogeny in Thailand under late diagenetic-anchimetamorphic conditions. The key differences between stratigraphic members that led to development of a detachment zone are bedding spacing and clay content. The lower, older, unit is the Khao Yai Member (KYM), which is a dark-gray to black, well-bedded, clay-rich limestone. The upper unit, the Na Phra Lan Member (NPM), comprises more massive, medium- to light-gray, commonly recrystallized limestones and marble. The KYM displays much tighter to even isoclinal, shorter-wavelength folds than the NPM. Pressure solution played a dominant role throughout the structural development—first forming early diagenetic bedding; later tectonic pressure solution preferentially followed this bedding instead of forming axial planar cleavage. The detachment zone between the two members is transitional over tens of meters. Moving up-section, tight to isoclinal folds with steeply inclined axial surfaces are replaced by folds with low-angle axial planes, thrusts, and thrust wedging, bed-parallel shearing, and by pressure solution along bedding-parallel seams (that reduce fold amplitude). In outcrops 100–300 m long, reduction of line-length shortening on folds from >50% to <10% shortening upwards indicates that deformation in the NPM is being accommodated differently from the KYM, probably predominantly by shortening on longer wavelength and/or spacing folds and thrusts, given the low amount of strain observed within the NPM, which excludes widespread layer-parallel thickening.

Research on surface segregation and overall segregation of particles in a rotating drum based on stacked image

At present, image recognition methods have been widely used in the research on measuring particle mixing and segregation in rotating drums. However, currently commonly used methods tend to study mixing and segregation from the perspective of the radial surface of the particles, but rarely from the perspective of the axial surface. Whether the data obtained from the particle surface (radial segregation or axial segregation) can reflect the degree of mixing and segregation of the entire particle system (overall segregation) is still a question worth studying. In this work, an image analysis method based on stacked images to measure the degree of surface segregation is proposed. The drum length to diameter ratio (L/D) and particle filling rate are used as operating parameters. And the discrete element method (DEM) verified by experiments has studied the difference between the surface segregation and the overall segregation of the binary particle groups (different particle sizes) in the rotating drum. This paper compares the qualitative characteristics (particle segregation characteristic patterns) and quantitative characteristics (particle segregation degree) of surface and overall mixing and segregation in detail. The results show that for short drums, radial segregation index can be used to quantify the overall degree of segregation. While for long drums, axial segregation index can be used to quantify the overall degree of segregation.

The geometric axial surface profiles of granular flows in rotating drums

SYNOPSIS A mechanistic description of axial segregation in rotating drum flows remains an open question. Consequently, optimal mixing of grinding balls and rocks for efficient breakage, maximum production of fines, and slurry transport is seldom achieved. Experimental and numerical studies of granular mixtures in rotating drums identify alternating axial bands that eventually coarsen in the long-term limit. Most models of axial segregation are limited to binary mixtures and cannot always predict the logarithmic coarsening effects observed experimentally. A key missing factor is a robust description of the axial free surface profile that is valid across a wide range of flow regimes. We present a practical model of the axial free surface profile by linking it to readily-derived geometric features of the cross-sectional S-shaped free surface profile. A parametric study shows good agreement with experimental measurements reported in the literature and heuristically valid trends. Keywords: rotating drum, granular flow, axial profile, comminution, mixing, segregation.

The Internal and Marginal Adaptation of Zirconia Based Fixed Dental Prostheses in the Posterior Region

Purpose:Long-term clinical success is closely related to the internal and marginal adaptation of the restorations. Thepurpose of this study was to evaluate the internal adaptation of zirconia-based fixed dental prostheses in the posteriorregion.Materials & Methods:Four-unit porcelain-fused to zirconia fixed dental prostheses were fabricated with CAD-CAMsystem in 20 patients. For the evaluation of the restorations’ internal fit, conventional silicone replicas were used withthe optical microscope. The obtained silicone impression was cut to obtain two cross-sections from buccolingual and 3from mesiodistal. Fifty different measurements were taken from every tooth by taking 10 from each cross- section; 2from the margin, 6 from the axial surfaces and 2 from the occlusal by the optical microscope.Results:There were statistically significant differences in internal discrepancy in terms of area and tooth type. Theaverage internal discrepancy on the axial surfaces of the molars was 142.39±47.42μm. In premolars, the mean was139.53±46.80μm. The average of the internal discrepancy values obtained from occlusal surfaces of the molar teeth was164.39±53.61μm, whereas the same average for the premolar teeth was 161.92±60.54μm.Conclusion:Within the limitations of this study, restorations fabricated by CAD/CAM and internal and marginaldiscrepancies were at clinically acceptable intervals

Moisture Influences of Some Physical and Gravimetric Properties of Ackee Apple Seeds (Blighia sapida

This research evaluated and determined some moisture-influenced physical and gravimetric properties of Blighia sapida seeds relevant to machine design at 11.9, 17.0, 22.0, 27.0 and 32.0% moisture levels (wet basis). These properties are vital in handling and seed process design. With increasing seed moisture (11.9 to 32.0%), there was no statistically significant effect on the seed axial dimensions, principal diameters, sphericity and surface area. This is because seed axial dimensions relatively determine other properties afore stated. However, there were significant and linear increases in thousand seed mass (189.3 – 230.3 g), bulk (377.0 - 418.3 kg m-3) and true (714.3 - 771.1 kg m-3) densities but decrease in porosity was not significant. Increase in bulk and true densities is due to the rate of increase in the seed mass being more rapid than the rate of increase in its volume, as the seed moisture increased. A non-linear decrease showed in seed volume (3.4-3.2 cm3). Behavioral patterns of ackee seeds and their investigated properties, under increasing moisture was expressed using regression models. Required primary data for the design of handling techniques and process machinery for ackee apple seeds were generated.

Effects of gas leakage from the dipleg on the pressure characteristics in a cyclone separator

AbstractGas leakage from the dipleg of a cyclone separator usually exists due to the the inlet and dipleg output being in a common space. To gain further insight into the pressure characteristics produced by such gas leakage, the pressure drops and instantaneous pressures in a cyclone separator were measured by a U‐tube and dynamic pressure sensors, respectively, under the conditions of different inlet velocities and gas leakage rates. The results showed that the pressure drop linearly decreased with increased gas leakage rate. And the instantaneous pressure fluctuation amplitudes of some regions were greatly affected by gas leakage variations. Instantaneous pressure data were processed in terms of SD, which revealed that the oscillation of the vortex core caused the pressure fluctuations. When the pressure of the upward gas leakage was equal to that of the axial wall surface, the end of the vortex core attached to the lateral wall and formed the larger pressure fluctuation. A power spectral density analysis was carried out for pressure time‐series data, and then the swing frequency (180 Hz) of the vortex core end was detected on the cyclone separator wall surface in the cone lower region (tapping 4). As a consequence, gas leakage could lead to separated particles being re‐entrained, which might heavily deteriorate separation performance of the cyclone separator.

Necking, beading, and bulging in soft elastic cylinders

Due to surface tension, a beading instability takes place in a long enough fluid column that results in the breakup of the column and the formation of smaller packets with the same overall volume but a smaller surface area. Similarly, a soft elastic cylinder under axial stretching can develop an instability if the surface tension is large enough. This instability occurs when the axial force reaches a maximum with fixed surface tension or the surface tension reaches a maximum with fixed axial force. However, unlike the situation in fluids where the instability develops with a finite wavelength, for a hyperelastic solid cylinder that is subjected to the combined action of surface tension and axial stretching, a linear bifurcation analysis predicts that the critical wavelength is infinite. We show, both theoretically and numerically, that a localized solution can bifurcate sub-critically from the uniform solution, but the character of the resulting bifurcation depends on the loading path. For fixed axial stretch and variable surface tension, the localized solution corresponds to a bulge or a depression, beading or necking, depending on whether the axial stretch is greater than a certain threshold value that is dependent on the material model and is equal to 23 when the material is neo-Hookean. At this single threshold value, localized solutions cease to exist and the bifurcation becomes exceptionally supercritical. For either fixed surface tension and variable axial force, or fixed axial force and variable surface tension, the localized solution corresponds to a depression or a bulge, respectively. We explain why the bifurcation diagrams in previous numerical and experimental studies look as if the bifurcation were supercritical although it was not meant to. Our analysis shows that beading in fluids and solids are fundamentally different. Fluid beading resulting from the Plateau–Rayleigh instability follows a supercritical linear instability whereas solid beading in general is a subcritical localized instability akin to phase transition.

Hindbrain and Spinal Cord Contributions to the Cutaneous Sensory Innervation of the Larval Zebrafish Pectoral Fin.

Vertebrate forelimbs contain arrays of sensory neuron fibers that transmit signals from the skin to the nervous system. We used the genetic toolkit and optical clarity of the larval zebrafish to conduct a live imaging study of the sensory neurons innervating the pectoral fin skin. Sensory neurons in both the hindbrain and the spinal cord innervate the fin, with most cells located in the hindbrain. The hindbrain somas are located in rhombomere seven/eight, laterally and dorsally displaced from the pectoral fin motor pool. The spinal cord somas are located in the most anterior part of the cord, aligned with myomere four. Single cell reconstructions were used to map afferent processes and compare the distributions of processes to soma locations. Reconstructions indicate that this sensory system breaks from the canonical somatotopic organization of sensory systems by lacking a clear organization with reference to fin region. Arborizations from a single cell branch widely over the skin, innervating the axial skin, lateral fin surface, and medial fin surface. The extensive branching over the fin and the surrounding axial surface suggests that these fin sensory neurons report on general conditions of the fin area rather than providing fine location specificity, as has been demonstrated in other vertebrate limbs. With neuron reconstructions that span the full primary afferent arborization from the soma to the peripheral cutaneous innervation, this neuroanatomical study describes a system of primary sensory neurons and lays the groundwork for future functional studies.

Effect of turning environments and parameters on surface integrity of AA6061-T6: experimental analysis, predictive modeling, and multi-criteria optimization

The present research investigates the effect of turning environments and parameters on surface integrity induced by turning of AA6061-T6. Specifically, the evolution of turning parameters of cutting speed, feed rate, and depth of cut was studied under dry, minimum quantity lubrication (MQL), and wet environments and their impact on surface roughness and residual stresses, as critical parameters for surface integrity, were quantified. Machining tests were carried out using a design of experiment (DoE) based on central composite design (CCD) under the three turning environments. The most effective turning parameters were identified for each environment using analysis of variance (ANOVA). Response surface method (RSM) was used to predict effective regression models for each turning environment for the average arithmetic surface roughness, the height peak from the valley, the axial surface residual stress, and the hoop surface residual stress. Then, using the predictive regression models, a multi-objective optimization study was performed to determine optimal turning parameters in each environment for improved surface integrity in low speed turning (LST) and high speed turning (HST) of AA6061-T6. The results showed that feed rate and cutting speed were the most effective parameters on surface integrity. It was also found that better surface integrity and higher material removal rate (MRR) were achieved using MQL mode, which is an environmental friendly and cost-saving turning environment.