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Curvilinear components made from solid wood bending not only enhance the use value of wood but also add a unique aesthetic to solid wood products, in line with the concept of green and sustainable development. In this study, we focused on the influence of the direction of the wood growth rings on the bending performance of teakwood and its bending mechanism, and radial and tangential bending experiments were conducted on teakwood using the synergistic softening method of a triethanolamine compounding solution and steaming. The results showed that the radial bending coefficient of the teakwood after softening treatment was 1/9.26, 41.39% higher than that for chordwise bending, 1/15.8. Through a macroscopic analysis, the stress distribution of the teakwood during radial bending was found to be uniform, while during tangential bending, the stress was mainly borne by many longitudinal growth rings, which are prone to the bending "destabilization" phenomenon. From SEM and AFM observations, it was found that the earlywood zone and latewood zone on the outermost tensile surface of the tangential bending are longitudinal; the stress redistribution problem still exists in the bending process; and ray parenchyma are the most vulnerable part, gradually extending to the earlywood zone and causing more serious bending tearing. It can be seen that the bending performance of teakwood is not only affected by the softening process but also obviously constrained by the direction of the growth rings, which is of great significance for the optimization of hardwood bending processing technology and product design. [ABSTRACT FROM AUTHOR]

Wood constitutes a unique and valuable material that has been used from ancient times until nowadays in a wide variety of applications, in which the surface quality of wood often constitutes a critical factor. In this study, the influence of different wood areas and therefore, of different anatomical characteristic areas of chestnut wood (Castanea sativa Mill.) on the surface quality, was thoroughly studied, in terms of surface roughness. Five different chestnut tree trunks were harvested, from which five different disks were obtained corresponding to five different trunk heights. Surface roughness was measured on these disks on the transverse, radial, and tangential planes, on the areas of sapwood and heartwood, measuring the roughness in each point both vertically and in parallel to the wood grain. The results revealed that the examined roughness indexes (Ra, Rz, Rq) follow a parallel path to one another. In the case of all surfaces (transverse, radial, tangential) of the disks examined, when the measurement was implemented perpendicularly to the wood grain, a significantly higher roughness was recorded, compared to the wood grain measurements being implemented in parallel with the wood grain. Significant differences between heartwood and sapwood roughness were not demonstrated, although sapwood often appeared to exhibit a higher surface roughness than heartwood sites. Among the roughness values of the three different surfaces, the highest roughness in the vertical-to-wood-grain measurements was recorded by tangential surfaces, with slightly lower values on the transverse surfaces and the lowest roughness on radial surfaces. Meanwhile, for the measurements in parallel with the wood grain, the transverse surfaces presented significantly higher roughness values compared to the tangential and radial surfaces. Significant roughness differences were not detected among the surfaces at different trunk heights. Although, significant differences in roughness were recorded among different trees, it was observed that all the studied trees align with the identified and described within-tree trends. [ABSTRACT FROM AUTHOR]

The cubic structure, a captivating geometric structure, finds applications across various areas of geometry through different models. In this paper, we explore the significant characteristics of tangentials in cubic structures of ranks 0, 1, and 2. Specifically, in the cubic structure of rank 2, we derive the Hessian configuration (12 3 , 16 4) of points and lines. Finally, we introduce and investigate the de Vries configuration of points and lines in a cubic structure. [ABSTRACT FROM AUTHOR]

Purpose: Peak tibial acceleration (PTA) is defined as the peak acceleration occurring shortly after initial contact, often used as an indirect measure of tibial load. As the tibia is a rotating segment around the ankle, angular velocity and angular acceleration should be included in PTA. This study aimed to quantify three-dimensional tibial acceleration components over two different sensor locations and three running speeds, to get a better understanding of the influence of centripetal and tangential accelerations on PTA typically measured in running. Furthermore, it explores tibial impulse as an alternative surrogatemeasure for tibial load. Methods: Fifteen participants ran 90 s on a treadmill at 2.8, 3.3, and 3.9m·s--1,with inertialmeasurement units (IMUs) located distally and proximally on the tibia. Results: Without the inclusion of rotational accelerations and gravity, no significant difference was found between axial PTA between both IMU locations, whereas in the tangential sagittal plane axis, there was a significant difference. Inclusion of rotational accelerations and gravity resulted in similar PTA estimates at the ankle for both IMU locations and caused a significant difference between PTA based on the distal IMU and PTA at the ankle. The impulse showed more consistent results between the proximal and distal IMU locations compared with axial PTA. Conclusions: Rotational acceleration of the tibia during stance differently impacted PTA measured proximally and distally at the tibia, indicating that rotational acceleration and gravity should be included in PTA estimates. Furthermore, peak acceleration values (such as PTA) are not always reliable when using IMUs because of inconsistent PTA proximally compared with distally on an individual level. Instead, impulse seems to be a more consistent surrogate measure for the tibial load. [ABSTRACT FROM AUTHOR]

In this research, we have investigated the interaction of two identical, very long, and parallel rod particles with planar and homeotropic anchorings in a two-dimensional nematic liquid crystal. The parallel axis of the rods is perpendicular to the nematic field at far distances. The planar and homeotropic anchorings on the surface of particles are perpendicular to the axis of the rods. This nematic field behavior leads to the two-dimensional director around the particles. To this end, we have approximated the study of the interaction of two identical rods in three dimensions to the study of the circular sections of these particles in two-dimensions. The nematic equilibrium field around the circular sections is obtained from the numerical minimization of the Landaude Genns free energy and the surface energy anchorings. The created particles and defects cause short-range and long-range interactions between particles. At far distances, the interaction between particles shows a quadrupole behavior compared to electrostatics. The interaction energy between particles at close contact has a symmetrical behavior around the spatial configuration of 45 degrees, which includes two equilibrium arrangements of the equilibrium configuration at zero and 90 degrees.

Few studies analysed the impact of different venous resection techniques on recurrence in patients with pancreatic ductal adenocarcinoma (PDAC). Primary aim was to compare local recurrence rate and disease-free survival (DFS) between patients who underwent pancreatectomy with tangential versus segmental resection of portal vein/superior mesenteric vein. All consecutive patients who underwent pancreatectomy with venous resection for PDAC between 2009 and 2019 were included. A propensity score matching (PSM) was used to reduce the effect of treatment selection bias. Overall, 120 patients (68%) underwent pancreatectomy with tangential venous resection and 57 patients (32%) were submitted to pancreatectomy with segmental venous resection. After a median follow-up of 24 months, local recurrence was comparable between the two groups (tangential: n = 32/120, 26.7% versus segmental: n = 10/57, 17.5%; p = 0.58). The median DFS was 17 months (IQR 9–31) in patients who underwent tangential resection, as compared to 12 months (IQR 5–21) in those who underwent segmental resection (p = 0.049). After PSM (n = 106), the median DFS was 18 months (IQR 9–26) in the tangential resection group, and 12 months (IQR 5–21) in the segmental resection group (p = 0.17). In the PSM population, lymph node ratio (HR 4.83; p = 0.028) and tumor size >25 mm (HR 3.26; p = 0.007) were identified as determinants of local recurrence. Tangential venous resections are not associated with a higher rate of local recurrence. Long-term outcomes are more related to tumors characteristics than to venous resection techniques. A step-up approach to vein resection, with tangential resection being performed whenever technically feasible, should be strongly encouraged. • Tangential vein resections are not associated with higher rates of local recurrence • Long-term outcomes are similar between tangential versus segmental venous resection • Tumor features rather than vein resection techniques affect survival outcomes • Tangential vein resections are associated with lower postoperative complications • Tangential vein resections should be preferred, whenever technically feasible [ABSTRACT FROM AUTHOR]

Computer Numerical Control (CNC) machines are increasingly popular in the production of furniture and wood products, because they combine high processing quality with short production time. The effective use of CNC machines depends on the processing parameters, which also affects the quality of the processed surface. The aim of this study was to determine the effect of feed rate, cutting direction, and grain direction on the surface roughness of various types of wood. Three European wood species (oak, beech, fir) were cut with a spindle speed of 16,000 rpm and two different feed rates (5,000 and 10,000 mm/min) using end mill tools on the CNC machine. The milling was performed in two cutting directions (radial and tangential) and two grain orientations (0° and 90°). An analysis of variance (ANOVA) was performed to evaluate the impact of the cutting parameters. The surface roughness measurements were taken, and two surface roughness parameters (Ra and Rz) were measured to determine the surface quality of the wood. According to the results of this study, the lowest surface roughness values, milling with the same processing parameters, occurred for oak wood, while the highest values occurred for fir. [ABSTRACT FROM AUTHOR]

Purpose: Scapholunate dissociation is a common and significant injury to the wrist. Radiographs are important in the diagnosis of this injury and in the planning of treatment. The tangential radiograph view was described almost 40 years ago as a method for accurately measuring scapholunate gaps. The hand is positioned on a 20° foam rubber block and the thumb on the cassette, which positions the scaphoid and lunate articular surfaces parallel, without patient discomfort or effort. The goal of this study was to review this method with more recent data and in a larger group of patients. Methods: Radiographs of 31 patients who had scapholunate interosseous ligament tears and surgical repair over a 9 year period were retrospectively evaluated. Each of the four authors independently measured scapholunate gaps for posteroanterior and tangential views. Results: The tangential view gaps were significantly greater than the posteroanterior gaps overall. Similar results were found for borderline cases where the posteroanterior gap was less than 3 mm. Every tangential view gap measurement was greater than its respective posteroanterior gap with good inter-rater reliability. Conclusion: The tangential view is a reliable radiographic method to identify scapholunate gaps. It should be obtained when there is clinical concern for scapholunate dissociation, especially in patients with borderline posteroanterior gaps. [ABSTRACT FROM AUTHOR]

Microsurgical resection of medial temporal brain arteriovenous malformations (AVMs) is typically conducted through 2 approaches: the orbitozygomatic-tangential and subtemporal-transcortical. Relative indications and outcomes for these techniques have not been formally compared. The cerebrovascular database of a quaternary center was reviewed for patients with medial temporal AVMs treated between January 1, 1997, and July 31, 2021. Demographic characteristics, lesion characteristics, surgical approaches, and outcomes were retrospectively analyzed and compared. Postoperative outcome testing was performed using the Montreal Cognitive Assessment and Global Quality of Life Scale. Fifty-nine patients were assessed. Mean (standard deviation) age was 31 (18) years; 30 (51%) patients were male. Of the AVMs, 29 (49%) were left-sided and 30 (51%) were right-sided. The tangential approach was selected in 20 (34%) cases, whereas the transcortical technique was preferred in 39 (66%). Improved modified Rankin Scale status was significantly associated with the tangential resection technique both in the early postoperative period (P = 0.02) and at last follow-up (P = 0.01). Differences between the tangential and transcortical approaches were not significant with respect to new postoperative deficits (5/20 [25%] vs. 12/39 [31%], P = 0.87) or the presence of residual AVM on follow-up angiography (1/20 [6%] vs. 5/39 [14%], P = 0.65). The orbitozygomatic-tangential strategy was associated with favorable functional and quality-of-life outcomes after medial temporal AVM resection. These benefits are likely to be attributable to minimization of temporal retraction, avoidance of brain transgression, and avoidance of traction on the vein of Labbé, rendering the orbitozygomatic-tangential approach the preferred option for cases that are anatomically amenable to either strategy. [ABSTRACT FROM AUTHOR]

Background: To provide improved treatment for hallux valgus (HV), we sought to understand more about the pathophysiologic connection between flatfoot deformity and HV by comparing coronal plane alignment of the medial column of the foot for patients with isolated HV, isolated flatfoot, and combined HV-flatfoot vs controls., Methods: This study retrospectively assessed a consecutive series of 33 patients with combined symptomatic and radiographic HV and flatfoot, 33 isolated symptomatic HV, 33 isolated symptomatic flatfoot, and 33 controls. The medial column alignment was assessed in the coronal plane using 3-dimensional weightbearing computed tomography (WBCT); rotation was measured for the navicular, medial cuneiform, and first metatarsal (M1). The position of the first naviculocuneiform (NC) and tarsometatarsal (TMT) joints were determined., Results: M1 intrinsic pronation was significantly greater in patients with combined HV-flatfoot (-12.0 ± 7.0 degrees; P  < .001), isolated HV (-12.1 ± 6.6 degrees; P  < .001), and isolated flatfoot (-11.8 ± 8.5 degrees; P  < .001), compared with control patients (-19.4 ± 6.7 degrees). TMT was significantly more pronated in patients with combined HV-flatfoot (30.9 ± 6.2 degrees) compared with isolated flatfoot (25.3 ± 9.3 degrees; P  = .007), and control (25.9 ± 5.2 degrees; P  = .005), as it was in patients with isolated HV (33.2 ± 8.2 degrees) compared with isolated flatfoot ( P  < .001), and control ( P  < .001). NC was significantly more supinated in patients with combined HV-flatfoot (-23.7 ± 3.9 degrees) compared to isolated flatfoot (-18.0 ± 9.8 degrees; P  = .001), and control (-18.0 ± 4.5 degrees; P  < .001), as it was for patients with isolated HV (-24.8 ± 7.1 degrees) compared with isolated flatfoot ( P  = .003), and control ( P  < .001)., Conclusion: In our study, we found that patients with isolated HV, isolated flatfoot, or combined HV-flatfoot presented a similar increase in M1 intrinsic pronation of approximately 7.5 degrees, compared with controls. Moreover, patients with isolated HV or combined HV-flatfoot had greater TMT pronation and NC supination, compared with patients with isolated flatfoot and controls., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Cesar de Cesar Netto, MD, PhD, reports general disclosures of personal fees from CurveBeam and Ossio. All other authors declare no competing interests. Disclosure forms for all authors are available online.

We consider here the problem of constructing a general recursive algorithm to interpolate a given set of data with a rational function. While many algorithms of this kind already exist, they are either providing non-minimal degree solutions (like the Schur algorithm) or exhibit jumps in the degree of the interpolants (or of the partial realization, as the problem is called when the interpolation is at infinity, see Rissanen (SIAM J Control 9(3):420–430, 1971) and Gragg and Lindquist (in: Linear systems and control (special issue), linear algebra and its applications, vol 50. pp 277–319, 1983)). By imbedding the solution into a larger set of interpolants, we show that the increase in the degree of this representation is proportional to the increase in the length of the data. We provide an algorithm to interpolate multivariable tangential sets of data with arbitrary nodes, generalizing in a fundamental manner the results of Kuijper (Syst Control Lett 31:225–233, 1997). We use this new approach to discuss a special scalar case in detail. When the interpolation data are obtained from the Taylor-series expansion of a given function, then the Euclidean-type algorithm plays an important role. [ABSTRACT FROM AUTHOR]

• ViTAT mimics the dose distribution of tangential fields (TF) plans. • Using 20° sectors of four arcs is needed to mimic the delivery of TF. • Better PTV homogeneity and lower dose to contralateral OARs are obtained. • Mean dose to ipsilateral OARs are unchanged; body integral dose reduced. • ViTAT may translate KB-models based on TF data into efficient automatic planning. To test the performances of a volumetric arc technique named ViTAT (Virtual Tangential-fields Arc Therapy) mimicking tangential field irradiation for whole breast radiotherapy. ViTAT plans consisted in 4 arcs whose starting/ending position were established based on gantry angle distribution of clinical plans for right and left-breast. The arcs were completely blocked excluding the first and last 20°. Different virtual bolus densities and thicknesses were preliminarily evaluated to obtain the best plan performances. For 40 patients with tumor laterality equally divided between right and left sides, ViTAT plans were optimized considering the clinical DVHs for OARs (resulting from tangential field manual planning) to constrain them: ViTAT plans were compared with the clinical tangential-fields in terms of DVH parameters for both PTV and OARs. Distal angle values were suggested in the ranges [220°,240°] for the right-breast and [115°,135°] for the left-breast cases; medial angles were [60°,40°] for the right side and [295°,315°] for the left side, limiting the risk of collision. The optimal virtual bolus had −500 HU density and 1.5 cm thickness. ViTAT plans generated dose distributions very similar to the tangential-field plans, with significantly improved PTV homogeneity. The mean doses of ipsilateral OARs were comparable between the two techniques with minor increase of the low-dose spread in the range 2–15 Gy (few % volume); contralateral OARs were slightly better spared with ViTAT. ViTAT dose distributions were similar to tangential-fields. ViTAT should allow automatic plan optimization by developing knowledge-based DVH prediction models of patients treated with tangential-fields. [ABSTRACT FROM AUTHOR]

The effects of cross-sectional geometry and force direction on bending strength (MOR) and modulus of elasticity (MOE) were investigated in selected softwoods. The specimens were constructed of Scots pine (Pinus sylvestris), Black pine (Pinus nigra), Siberian pine (Pinus sibirica), Stone pine (Pinus pinea), Nordmann fir (Abies nordmanniana), Oriental spruce (Picea orientalis), and Lebanon cedar (Cedrus libani). A total of 280 specimens were prepared from these seven species in two different cross-sectional geometries (circular and square, equal in area) and tested in two characteristic force directions (tangential and radial) by 10 replications. They were subjected to three-point bending tests according to TS 2474 (2005) and TS 2478 (2005) to obtain the MOR and MOE. The results showed that the type of cross-sectional area and direction of applied force, individually or together, had considerable effects on the MOR and MOE. The MOR values of the circular-sectioned specimens were 5% greater than those of the square-sectioned specimens. The MOE values of the circular-sectioned specimens were on average 19% greater than those of the square-sectioned specimens. The MOR and MOE values were on average 7% and 17% greater, respectively, for the force applied in the tangential direction. [ABSTRACT FROM AUTHOR]

Novel relations are developed for the tangential and normal derivatives of the pressure, density, and velocity components just downstream of a regular point on a curved shock wave. The perfect gas flow is three dimensional with a nonuniform freestream and the flow may be unsteady. The analysis starts with data in a fixed, laboratory-frame Cartesian coordinate system. By means of an orthogonal transformation, a coordinate system is introduced via a solid-body translation and two solid-body rotations. This Cartesian system is shock based and limits the analysis to a selected shock point at a given instant of time when the flow is unsteady. The analysis is a local one in that Taylor series expansions are utilized for the configuration of the shock and the upstream gradients of the velocity, pressure, and density. The coefficients in the last three expansions must satisfy Euler equation constraints. These expansions are performed in both Cartesian systems, with occasional preference given to the laboratory-frame expansions where there are known data. The derivatives are in terms of a third coordinate system that is shock based and utilizes the flow plane at the selected shock point. Exact, explicit results are provided for the tangential and normal derivatives in as simple a form as possible. In the Taylor series expansion version for the tangential derivatives, the relative importance of various factors can be assessed. These are the upstream velocity, pressure, and density gradients, curvatures, and shock-shape terms not associated with curvatures. A different type of discussion is provided for the more involved normal derivatives. [ABSTRACT FROM AUTHOR]

Due to the complicated wheel–rail contact relation of railway turnouts, it is necessary to select a reasonable rolling contact model to simulate the vehicle–turnout dynamics and wheel–rail damages. This paper mainly aims to evaluate the calculation accuracy and efficiency of different non-Hertzian modeling approaches in solving normal and tangential wheel–rail contact problems of railway turnouts. Four different non-Hertzian approaches, namely CONTACT, Kik–Piotrowski, Ayasse–Chollet, and Sichani methods are compared and analyzed. The above four models are built considering the relative motion of stock/switch rails. A wheel profile called LMA contacting with stock/switch rails (head width 35 mm) of CN60-1100-1:18 turnouts is selected as the object of analysis. The normal contact problems are evaluated by the wheel–rail contact areas, shapes, and normal contact pressures. The assessment of tangential contact problems is based on the creep curves, tangential contact stresses, and distribution of the stick/slip region. In addition, a contrast analysis is performed on the calculation efficiencies of the four approaches. It is found that the normal and tangential contact results calculated based on the Sichani method coincide well with those obtained according to CONTACT, and the calculation efficiency is about 262 times that of CONTACT. The conclusions can provide some guidance to the selection of wheel–rail rolling contact approach in the simulation of vehicle–turnout dynamics and wheel–rail damages. [ABSTRACT FROM AUTHOR]

Wood shrinks anisotropically as it loses hygroscopic moisture. While longitudinal shrinkage (parallel to the grain) is nearly negligible in normal wood, transverse shrinkage (across the grain) is significant and characterized as tangential and radial shrinkage. The application of average tangential shrinkage values to a rectangular cross section results in errors, especially for boards cut from near the center of the log. In addition, using a Cartesian coordinate system to calculate shrinkage cannot provide an estimate of cup. Calculating shrinkage and cup deformation using a previously developed model, this Excel model can provide a more realistic image of the final cross section and a more accurate estimate of shrinkage. The model is dependent on wood species, initial and final moisture contents, and location of the board within the log. This paper describes and illustrates uses of the model.

The nano calcium carbonate with a smaller particle size is prepared by carbide slag in the improved tangential jet-reactor, and is characterized by means of SEM, XRD, and the specifics surface area. The results show that the particle agglomeration is mainly positively related to the calcium hydroxide saturation and liquid flow rate. And the particle size is correlated with liquid flow rate and carbon dioxide flow rate and concentration. And the sample obtained in the improved tangential jet-reactor has a smaller particle size than the bottom jet-reactor under the same conditions. Moreover, the specific area of calcium carbonate prepared under the optimal condition has increased from 8.3065 m ^2 g ^−1 to 11.3829 m ^2 g ^−1 , and the particle size reduces from 266 nm to 199 nm by 27%.

Volumetric modulated arc therapy (VMAT) has been implemented for left breast irradiation to reduce prescription dose to the heart and improve dose homogeneity across the targeted breast. Our in‐house method requires application of a bolus during the optimization process with a target outside of the body, then removing the bolus during the final calculation in order to incorporate skin flash in VMAT plans. To quantify the dosimetric trade‐offs between traditional 3D field‐in‐field tangents and VMAT with integrated skin flash for these patients, we compared nine consecutive patients who recently received radiation to their entire left breast but not their regional lymphatics. Tangent plans used non‐divergent tangents of mixed energies and VMAT plans utilized four 6 MV arcs of roughly 260°. Mean dose to the heart, contralateral lung, and contralateral breast and their volume receiving 5%, 10%, and 20% of the prescription dose were higher in all nine VMAT plans than in the static tangential beam plans. For all critical structures, the mean VMAT DVH was higher in the low‐dose region and crossed the 3D field‐in‐field DVH between 23.13% and 34.18% of the prescription dose (984.75‐1454.70 cGy). However, the volume of the contralateral breast and heart receiving the prescription dose was slightly lower in the VMAT plans, but not statistically significant. VMAT provided superior homogeneity, with a mean homogeneity index of 9.41 ± 1.64 compared to 11.05 ± 1.82 for 3D tangents. Results indicate that VMAT spares the heart, contralateral lung, and contralateral breast from prescription dose at the cost of increasing their mean and low‐dose volume and delivers a more homogenous dose distribution to the breast. For these reasons, VMAT is selectively applied at the request of the physician for left breast radiation without respiratory gating to spare the heart from prescription dose in cases of poor anatomical geometry. [ABSTRACT FROM AUTHOR]

Abstract: Radiotherapy to the breast after surgery sometimes requires adjoining nodes to be included in the treatment volume. In these cases, the traditional approach has been a complex 3‐Dimensional Conformal Radiotherapy (3DCRT) beam arrangement which can result in significant dose heterogeneity at the beam junctions. A Volumetric Modulated Arc Therapy (VMAT) beam arrangement has previously been proposed for breast cases, where the chest wall/breast is treated with a limited angle (partial arc) tangential VMAT technique (Virén et al. [2015] Radiat Oncol. 10:79). In our study, this approach is extended to breast and chest wall cases with adjoining nodes by adding a separate conventional VMAT arc field specifically limited to the superior nodes. This VMAT method was implemented using a semiautomated approach on 27 patients, and the resultant plan compared to a monoisocentric 3DCRT plan. Plan statistics, Dose‐Volume Histogram (DVH) analysis and Radiation Oncologist (RO) preference were assessed. When compared to the 3DCRT technique, the VMAT planning method was found to result in better target volume coverage, high doses to organs at risk (OAR) were reduced but greater OAR volumes received low doses. Having said that, the volume receiving low doses with this tangential VMAT technique was less than that of other VMAT planning methods described in the literature, and the integral dose was less than the 3DCRT method. The VMAT technique also resulted in more robust junction doses that the 3DCRT method. RO review found that the VMAT technique was preferred in 81% of cases. Specifically, the VMAT plans were preferred in all categories of patients except left chest wall cases where the intermammary nodes were also treated. The VMAT technique described here is a useful addition to the treatment options available for breast/chest wall and nodal patients. [ABSTRACT FROM AUTHOR]

To clarify or interpret the measurement results of double-flank gear measurement (DFGM), the mathematical model of radial and tangential error analysis of double-flank gear measurement is established. Using differential method, the mathematical model of surface-to-surface contact stage is concerned, and also the tip-to-surface interference stage is involved. The error sources including the base radius error (or profile slope deviation) and the tooth space angle error (or single pitch deviation) of the gear to be measured are concerned. A case study of the gear parameter with the gear contact ratio 1.77 is discussed to explain the tooth contact process, in which the critical contact points are listed for determining the rotation angle. The radial and tangential composite deviations are simulated under different sign combination or different value of the error sources to cover as many results as possible. The simulation results are compared with the measurement results on a gear measuring device (GMD) using double flank rack probe (DFRP), whereby the simulation parameters are determined through the gear profile slope deviation and the single pitch deviation of the gear measured on a Gear Measuring Center Klingelnberg P26. The curves of the simulation results and the measurement results on GMD are consistent to each other. For gear grade 6 according to ISO 1328-1:2013, the allowable value of the total profile deviation is 11.5 μm. The simulation results are compared with the measurement results on a gear measuring device (GMD) based on double flank rack probe (DFRP). The difference between the peak to peak value of the simulation results and the mean line of the measurement results within the evaluation range is 1 μm in radial direction and 1.3 μm in tangential direction, which means the simulation results has better consistency with the measurement results. The radial and tangential error analysis of DFGM can not only be used in simulation of the results, but also in interpreting the DFGM measurement results, which is helpful for gear measurement and quality control. [ABSTRACT FROM AUTHOR]

Tornadoes are generally defined as rotating columns of air characterized by small size, axisymmetry and short duration. Thus, the nature of tornadic wind load is basically different from that of synoptic wind. As direct measurements of velocities are very difficult and limited, lots of empirical and theoretical expressions of tornadic wind have been proposed. In the present study, characteristics of several numerical expressions were investigated, and it was found that the characteristics of velocity fields vary widely from model to model, making it difficult to choose one that is generally applicable. [ABSTRACT FROM AUTHOR]

Modeling fracture with a cohesive zone model requires an appropriate cohesive law for correlating interfacial tractions and crack face separation, especially in mixed-mode loading scenarios. Various approaches have been employed in order to develop such a law which can be characterized into potential-based and non-potential-based formulations. A critical re-examination of these methods is presented here, followed by a novel mixed-mode formulation which satisfies a physical criterion for crack propagation. Specifically, as the crack propagates, the trailing current crack tip is defined through the vanishing of normal and tangential components of the interfacial tractions simultaneously. A general formulation for mixed-mode conditions is proposed in this paper. In particular, given normal and tangential traction separation laws for pure normal and tangential modes as being material properties, the normal and tangential traction separation laws in mixed-mode loading are formulated so that all traction components disappear at the same effective separation when the crack advances. The new mixed-mode law is used to analyze three standard fracture problems in laminated composites, including double cantilever beam (DCB), end-notch flexure (ENF), and mixed-mode bending (MMB). A comparison with predictions from some selected mixed-mode cohesive laws and experimental data available in the literature is also included to further validate the proposed mixed-mode law. [ABSTRACT FROM AUTHOR]

This study proposes a new dynamic model of a brake system that combines pad tangential motion and disk torsional motion to reduce the vibration and noise of the brake system. The stability analysis of this system with a smoothed Stribeck friction model verified its instability, which is caused by Hopf bifurcation. Moreover, numerical simulation showed several phenomena of the system vibration changing with angular velocity: (1) the system vibration maintains in the stable limit cycle after Hopf bifurcation within a relatively wide range of low angular velocity and (2) period-doubling bifurcation and chaos will occur only by decreasing the angular velocity. This study further discusses the effects of friction parameter on stick–slip vibration within a common range of brake pressure under “low” and “lower” angular velocities; the result shows that a decrease of both μ s − μ k and decay factor can effectively reduce the range of chaotic vibration region. [ABSTRACT FROM AUTHOR]

Wood shrinks anisotropically as it loses hygroscopic moisture. While longitudinal shrinkage (parallel to the grain) is nearly negligible in normal wood, transverse shrinkage (across the grain) is significant and characterized as tangential and radial shrinkage. The application of average tangential shrinkage values to a rectangular cross section results in errors, especially for boards cut from near the center of the log. In addition, using a Cartesian coordinate system to calculate shrinkage cannot provide an estimate of cup. Calculating shrinkage and cup deformation using a previously developed model, this Excel model can provide a more realistic image of the final cross section and a more accurate estimate of shrinkage. The model is dependent on wood species, initial and final moisture contents, and location of the board within the log. This paper describes and illustrates uses of the model. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to evaluate the accompanied cervical injuries of the patients presenting to the emergency department (ED) because of penetrating, perforating or tangential cranial gunshot injuries (CGI). Material and Methods: The retrospective study included 137 patients that presented to the EDs at Mustafa Kemal and Ataturk University due to penetrating, perforating or tangential CGI between 2014 and 2018. Patients younger than 12 years old and had insufficient radiological records were excluded from the study and thus 115 patients were included in the study. Results: 115 patients included 105 (91%) men and 10 (9%) women with a mean age of 27 (range, 12-65) years. Of the 115 injuries, 84 (73%) were high-velocity and 31 (27%) were low-velocity gunshot injuries. The injuries included 92 (80%) penetrating or perforating and 23 (20%) tangential injuries. No cervical dislocation injury was accompanied by CGI in any patient. Unilateral lamina fracture of the cervical vertebra was observed in one patient. Conclusion: Our results support the opinion that isolated penetrating, perforating or tangential CGI did not cause to cervical spinal injuries, the intubation or tracheostomy procedures should not be postponed after radiological evaluation of cervical spinal stability. [ABSTRACT FROM AUTHOR]

In the present paper three dimensional cutter deflections and the corresponding profile errors during end milling are predicted by finite element and bond graph modeling approach. The deflections have been modeled considering the cutter as a cantilever beam fixed at the collet end. Rayleigh beam model is used for modeling to consider the shear force effect, and Castigliano's theorem of strain energy is used to predict the deflections due to radial, tangential, and axial cutting forces. The tool-workpiece contact region is sliced into small elements to apply the forces on the entire contact region and predict deflections more accurately. The predicted deflections at different parametric settings are compared with experimental measurements by measuring the geometric accuracy of the cut profiles. The depth of cut has the most significant influence on profile deviations, while feed and speed have marginal effects. The results reveal that the predictions by finite elements and the bond graph closely matches with the experimental results, and errors of the machined profile are significantly influenced by the radial and tangential deflections. The axial deflection is negligible and leads to insignificant deviation in depth of the cut profile. The proposed model shows that the bond graph simulation takes significantly less computational time and space as compared to the finite element technique. [ABSTRACT FROM PUBLISHER]

Background: Military neurosurgeons have long known that tangential cranial gunshot wounds can be associated with intracranial complications out of proportion to the external appearance of the injury. This phenomenon seems not to have been described in infancy., Observations: An infant suffered a massive, acute subdural hemorrhage from a contralateral tangential gunshot wound that did not facture the skull., Lessons: Similar to adults, infants are subject to catastrophic intracranial injury from gunshots that do not penetrate the skull. The nature of the injury in this case reflected distinctive aspects of the tissue characteristics and proportions of the infant head.

• The nozzle axes were tangential to a horizontal cylinder to form staggered vortexes. • The flow perpendicular to central-plane between two sidewalls was strengthened. • The best performance was achieved when θ = 22.1° and d/D = 0.34. • Flashlight frequency and CO 2 fixation rate increased by 90.9% and by 30%. A novel three-dimensional tangential swirl plate (TTSP) photobioreactor was proposed to strengthen flow perpendicular to central cross-section between two side walls, resulting in more widespread turbulence for improving microalgal CO 2 fixation. The axes of four center-symmetrically arranged nozzles were tangential to a horizontal cylinder to form two staggered vortexes. When angle θ between nozzle axis and central cross-section increased from 0° to 22.1° and then to 40.0°, mixing time and average bubble diameter first decreased to the minimum (16.55 s and 0.57 mm) and then increased. When relative diameter of tangential cylinder d/D increased from 0.11 to 0.34 and then to 0.56, flashlight frequency and light time ratio first increased to the maximum (0.21 Hz and 42.8%) and then decreased. Accordingly, flashlight frequency was 90.9% higher in TTSP photobioreactor than that in two-dimensional jet-aerated tangential swirl plate (JTSP) photobioreactor, leading to an increase in microalgal CO 2 fixation rate by 30%. [ABSTRACT FROM AUTHOR]

One process to improve wood quality is densification or wood surface compression. Our study analyzed the changes in some basic properties of pine wood, including its anatomical structure, density, modulus of elasticity (MOE), and dimensions of cellulose crystallites, after densification following soaking pretreatment in CH3COOH and H2O2 at a concentration of 20%. Samples were sawn in radial and tangential directions for analysis of the wood. The results showed a change in the shape of tracheid cells from hexagonal to oval, as well as damage to the ray cell constituents on the tangential surface. The thickness decrease of the samples was in accordance with the target, which meant that spring-back was short. In general, the tangential boards had a higher density than the radial boards, with a lower MOE and crystallite dimensions. Our findings showed that the densified tangential board was stronger than the radial board. [ABSTRACT FROM AUTHOR]