Plane Thickness Research Articles

Zygomatic-maxillary cortical bone thickness in hyper, normo and hypodivergent patients

ABSTRACTObjective: The aim of this study was to evaluate the thickness of the zygomatic-maxillary cortical bone using computed tomography in different skeletal patterns. Methods: A total of 54 patients of both sexes, divided into three groups according to the vertical skeletal pattern, were evaluated for cortical bone thickness of the anterior slope of the zygomatic process of the maxilla, using cone beam computed tomography. Measurements were made at 2mm, 4mm, 6mm, 8mm and 10mm above from first molar mesial root apex. Vertical skeletal pattern was determined by Frankfurt mandibular angle (FMA).Results: The hyperdivergent pattern had the lowest cortical thickness value, nevertheless, no patient in the hyperdivergent group presented cortical thickness exceeding 2mm, and no patient in the hypodivergent group presented cortical thickness less than 1mm. However, the correlation between cortical thickness and mandibular plane angle was weak and not significant. Conclusion: Although higher prevalence of thick cortical was observed in the hypodivergent patients, and thin cortical groups in the hyperdivergent group, the vertical skeletal pattern could not be used as determinant of the zygomatic-maxillary cortical thickness.

Effect of rake surface textures spacing and width on the cutting performance of inserts in dry machining of titanium alloy

One of the crucial parameters that can be altered to improve machining efficiency in metal cutting is reducing the friction between tool and chip, especially along the rake surface of the tool. Studies have shown that many parameters of the micro or nanoscale texturing on the tool surface may influence its competence in reducing friction. However, the influence of texture parameters like width, spacing, etc. is not well understood, especially in the dry machining of hard alloys. In this experimental investigation, uncoated single point cutting tool inserts with different texture geometries on their rake surface were tested for adequacy in the typical turning operation of titanium alloy. The novelty of the study involves identifying the influence of texture spacing and width on the cutting parameters at different feeds in the dry machining of the Ti-6Al-4V alloy. The surface characterisation of the inserts shows how the textured surface was damaged under the machining regime. Chip morphology analysis was conducted to study the effect on chip thickness and shear plane angle. Inferences were made on the effect of texture dimensions on the frictional forces during machining.

Fascial Plane Blocks: More Questions Than Answers?

Fascial Plane Blocks: More Questions Than Answers?

Histological Validation of MRI: A Review of Challenges in Registration of Imaging and Whole-Mount Histopathology.

Rigorous validation with ground truth information such as histology is needed to reliably assess the current and potential value of MRI techniques to characterize tissue and identify disease-related tissue alterations. Commonly used methods that aim to directly correlate histology and MRI data generally fall short of this goal due to spatial errors that preclude direct matching. Errors result from tissue deformation, differences in spatial resolution and slice thickness, non-coplanar and/or nonintersecting plane orientations, and different image contrast mechanisms. Some of these problems arise from limitations in standard protocols for clinical tissue processing and histology-based pathology reporting, and to some extent can be addressed by modifications to standard protocols without compromising the clinical process. Typical modifications include ex vivo specimen MRI, block-face photography, addition of fiducial markers, and 3D printed molds to constrain tissue deformation and guide sectioning. This review summarizes the advantages and limitations of MRI validation techniques based on coregistration of MRI with whole-mount histology of tissue specimens. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY STAGE: 1.

Right Ventricular Dimensions and Tricuspid Annular Plane Systolic Excursion among Medical Students of Tertiary Care Hospital: A Descriptive Cross-sectional Study.

The change in morphology and functions of the right ventricle is an important predictor of heart and lung disease. There is limited data on the normal dimension of the right ventricle. The study aimed to find the right ventricular diameter, its thickness, and tricuspid annular plane systolic excursion in healthy male medical students of a tertiary care hospital. It is a descriptive cross-sectional study conducted in healthy medical students of Kathmandu Medical College and Teaching Hospital, from February-April, 2019. Ethical approval was taken from the institutional review committee (reference number 120720193). Convenient sampling method was used. We measured various dimensions of the right ventricle in different views. The data was analyzed in the Statistical Package for the Social Sciences. In the 96 male students included in the study, the mean right ventricular basal diameter was 36.45±3.49 mm, right ventricular mid cavity diameter was 29±3.63 mm, right ventricular longitudinal dimension was 65.72±7.52 mm, right ventricular outflow tract in parasternal long-axis view was 27.07±2.12 mm, proximal and distal right ventricular outflow in parasternal short-axis view was 25.33±2.57 mm and 20.08±1.99 mm, right ventricular thickness was 4.20±0.54 mm, and tricuspid annular plane systolic excursion was 23.02±3.54 mm. The study found that the values of right ventricular dimensions and the right ventricle's tricuspid annular plane systolic excursion among male medical students of a tertiary care hospital to be in accordance with the guidelines by the American Society of Echocardiography. The upper limits of the normal values of the right ventricle could be very helpful in clinical practice in determining the right ventricle dimension.

Theoretical and experimental studies on tapered plate-rubber isolator

Earthquake is one of the biggest threats for multi-story buildings in the developing countries. Thus, a cost-effective base isolation bearing is designed to overcome the challenge. Tapered plate-rubber isolator consists of a set of cover plates and a detached rubber interlayer, which can balance seismic isolation and economic expenditure. Theoretical and experimental studies will focus on the hysteretic behaviors. Energy consumption of three design parameters is discussed, including the slope of the tapered plane surface, elasticity and thickness of the rubber sheet. Effective stiffness and damping ratio are derived by the hysteretic energy dissipation curves, and finally shaking table test is set up to evaluate the structural reaction. Results indicate that tapered plate-rubber isolator can dissipate seismic energy efficiently, which will minimize the dynamic responses of the superstructure. Low-cost, easy manufacture and high earthquake energy dissipation will support it to be an efficient isolation bearing for the multi-story buildings.

Effects of bedding structures on the propagation characteristics of acoustic waves in shales at operating frequencies of acoustic logging

Acoustic characteristics measured by acoustic logging are usually used to estimate the structures and mechanical properties of rock materials. However, it is problematic to measure acoustic characteristics of shales because of their structural anisotropy caused by the bedding structures. This study focused on the effects of bedding structures on the acoustic characteristics of shales at operating frequencies of acoustic logging. A numerical model was first established to estimate the acoustic characteristics of shales based on the viscoelastic theory. Then, acoustic transmission experiments were conducted to examine the acoustic characteristics of shales with different bedding angles. The model calculations were compared with experimental results, showing good agreement. Based on the model, the effects of the angle, density, and thickness of bedding planes on the acoustic characteristics of shales at operating frequencies of acoustic logging were analyzed in detail. The results indicate that the wave velocity and main amplitude increased with increasing bedding angle whereas the attenuation coefficient decreased. The wave velocity monotonically decreased with an increase in the bedding density and thickness when the acoustic waves were transmitted through the shale model, but the attenuation of acoustic waves exhibited an opposite trend with the slope. In comparison, the dominant frequency was relatively stable with variations in the bedding structures. In general, the effect of bedding thickness on the acoustic characteristics of shales was smaller than those of the bedding angle and bedding density. The findings of this study can be beneficial for the accurate measurement of shale acoustic characteristics in acoustic logging.

The quirk trajectory

We for the first time obtain the analytical solution for the quirk equation of motion in an approximate way. Based on it, we study several features of quirk trajectory in a more precise way, including quirk oscillation amplitude, number of periods, as well as the thickness of quirk pair plane. Moreover, we find an exceptional case where the quirk crosses at least one of the tracking layers repeatedly. Finally, we consider the effects of ionization energy loss and fixed direction of infracolor string for a few existing searches.

A Robust HDG Method for Reissner-Mindlin Plate Problem

We propose and analyze a hybridizable discontinuous Galerkin (HDG) method for Reissner-Mindlin plate problems. The method uses piecewise-polynomials of degree k(≥ 1) to approximate the transverse displacement and the displacement trace on inter-element boundaries, uses piecewise-polynomial vectors of degrees k and ‘, max(1; k - 1) ≤ ‘ ≤ k, to approximate respectively the rotation and the rotation trace on inter-element boundaries, and uses piecewise-polynomial vectors of degree k and piecewise-polynomial tensors of degree m, k - 1 ≤ m ≤ ‘, to approximate respectively the shear stress and the bending moment. We show that the HDG method is robust in the sense that the derived a priori error estimates are optimal and uniform with respect to the plane thickness t. Numerical experiments are performed to confirm our theoretical results.

Proposing a Minimal Data Set of Musculoskeletal Ultrasound Imaging Biomarkers to Inform Clinical Practice: An Analysis Founded on the Achilles Tendon

Tendon integrity can be described using a wide range of biomarkers via specialized analysis software for images recorded by musculoskeletal ultrasonography. This study proposes a minimal biomarker data set to characterize Achilles tendon ultrasound images and to differentiate between symptomatic and asymptomatic Achilles tendon images. Forty-one individuals with unilateral Achilles tendinopathy and 35 healthy controls had their Achilles tendon images recorded bilaterally by ultrasonography in the longitudinal and transverse planes. A set of 22 biomarkers, organized around three dimensions (geometric, composition and texture), were computed in each plane. A symmetry index, reflecting relative side differences, was compared between groups and analyzed through principal component analysis to isolate biomarkers that best explained data variance. A specific minimal data set was identified by linear regression in the longitudinal (mean thickness, echogenicity, variance and homogeneity at 90°) and transverse (mean thickness, echogenicity and mean homogeneity) planes to characterize and differentiate Achilles tendon integrity.

Optimizing Simulation Parameters for Weak Lensing Analyses Involving Non-Gaussian Observables

Abstract We performed a series of numerical experiments to quantify the sensitivity of the predictions for weak lensing statistics obtained in ray-tracing dark matter (DM)-only simulations, to two hyper-parameters that influence the accuracy as well as the computational cost of the predictions: the thickness of the lens planes used to build past light cones and the mass resolution of the underlying DM simulation. The statistics considered are the power spectrum (PS) and a series of non-Gaussian observables, including the one-point probability density function, lensing peaks, and Minkowski functionals. Counterintuitively, we find that using thin lens planes (< 60 h −1 Mpc on a 240 h −1 Mpc simulation box) suppresses the PS over a broad range of scales beyond what would be acceptable for a survey comparable to the Large Synoptic Survey Telescope (LSST). A mass resolution of 7.2 × 1011 h −1 M ⊙ per DM particle (or 2563 particles in a (240 h −1 Mpc)3 box) is sufficient to extract information using the PS and non-Gaussian statistics from weak lensing data at angular scales down to 1′ with LSST-like levels of shape noise.

Design of Circular Waveguide Annular Slot-Coupled Two-Layer DRA for Linear and Circular Polarizations

The design of a circular-waveguide coupled two-layer dielectric resonator antenna (DRA) configuration is presented. It is observed that besides a reduction in the number of layers compared to a rectangular waveguide coupled multilayer-DRA structure to achieve coupling and enhanced bandwidth, the current configuration significantly enhances the functionality of the design in the realization of dual band and right-hand/left-hand circularly polarized (RHCP/LHCP) configurations without the use of additional coupling or matching elements, which, to the best of our knowledge, has not been reported earlier. Radiation characteristics with low cross-pol are achieved for the linearly polarized dual-band antenna structure. For the circularly polarized configurations, a good axial-ratio performance and a high isolation between the RHCP and LHCP fields are achieved. The computed results are obtained through a full-wave Green's function analysis of the structure, with the thickness of the ground plane modeled as an annular cavity.

Wave-transmitting material to optimize impedance matching and enhance microwave absorption properties of flaky carbonyl iron coating

Flaky carbonyl iron particles/nano silicon dioxide/Polyurethane (FCIP/SiO2/PU) composites coatings were fabricated. And FCIP were fabricated from sphere carbonyl iron particles (SCIP) by ball milling. The electromagnetic parameters of absorbers (SCIP, FCIP and SiO2) and the reflection loss (RL) of coatings were measured in the frequency range of 2–18 GHz. The results showed that the complex permeability and absorbing properties of FCIP are significantly enhanced compared with SCIP because of its smaller thickness and easy magnetization plane. In addition, as a low dielectric material, SiO2 can build more wave-transmission channels and optimize the impedance matching, making more electromagnetic wave transmitting into the coatings and being attenuated. Due to the addition of SiO2, the absorbing properties and effective absorption bandwidth of coatings are further enhanced. The reflection loss values exceeding − 10 dB can be obtained in the frequency range of 8.5–18 GHz with a thickness of 1 mm.

Maxillary molar enamel thickness of Plio-Pleistocene hominins

Enamel thickness remains an important morphological character in hominin systematics and is regularly incorporated into dietary reconstructions in hominin species. We expand upon a previous study of enamel thickness in mandibular molars by examining a large maxillary molar sample of Plio-Pleistocene hominins (n = 62) and a comparative sample of extant nonhuman apes (n = 48) and modern humans (n = 29). 2D mesial planes of section were generated through microtomography, and standard dental tissue variables were measured to calculate average enamel thickness (AET) and relative enamel thickness (RET). AET was also examined across the lingual, occlusal, and buccal regions of the crown. This study confirms previous findings of increasing enamel thickness throughout the Plio-Pleistocene, being thinnest in Australopithecus anamensis and peaking in Australopithecus boisei, with early Homo specimens, exhibiting intermediate enamel thickness. Agreeing with previous findings, 2D plane of section enamel thickness is found to be a poor taxonomic discriminator, with no statistically significant differences observed between fossil hominins. For fossil hominins, modern humans, and Pongo, the occlusal region of enamel was the thickest, and the lingual enamel thickness was greater than buccal. Pan and Gorilla present the opposite pattern with enamel being thinnest occlusally. Comparison at each molar position between the maxilla and mandible revealed very few significant differences in fossil hominins but some evidence of significantly thicker maxillary enamel (AET) in modern humans and thinner maxillary enamel in Pan (RET).

3-D magnetohydrodynamic AA7072-AA7075/methanol hybrid nanofluid flow above an uneven thickness surface with slip effect

A 3-D magnetohydrodynamic flow of hybrid nanofluid across a stretched plane of non-uniform thickness with slip effects is studied. We pondered aluminum alloys of AA7072 and AA7072 + AA7075 in methanol liquid. The aluminum alloys amalgamated in this study are uniquely manufactured materials, possessing enhanced heat transfer features. AA7072 alloy is a composite mixture of Aluminum & Zinc in the ratio 98 & 1 respectively with added metals Silicon, ferrous and Copper. Equally, AA7075 is a mixture of Aluminum, Zinc, Magnesium, and Copper in the ratio of ~90, ~6, ~3 and ~1 respectively with added metals Silicon ferrous and Magnesium. Numerical solutions are attained using R-K based shooting scheme. Role of physical factors on the flow phenomenon are analyzed and reflected by plots and numerical interpretations. Results ascertain that heat transfer rate of the hybrid nanoliquid is considerably large as matched by the nanofluid. The impact of Lorentz force is less on hybrid nanofluid when equated with nanofluid. Also, the wall thickness parameter tends to improve the Nusselt number of both the solutions.

External transcutaneous ultrasound technique in the equine cricoarytenoideus dorsalis muscle: Assessment of muscle size and echogenicity with resting endoscopy.

Recent studies have assessed the cricoarytenoideus dorsalis muscle (CAD) using transoesophageal ultrasonography in equine recurrent laryngeal neuropathy (RLN). We assessed the CAD using the external transcutaneous ultrasound technique, which may constitute an easier method in horses. To evaluate ultrasonographic imaging of the left cricoarytenoideus dorsalis muscle (LCAD) and right cricoarytenoideus dorsalis muscle (RCAD) as a diagnostic tool for RLN using the transcutaneous ultrasound technique. Cross-sectional study. The axial plane thickness, cross-sectional area and echogenicity of the LCAD and RCAD were measured using transcutaneous ultrasonography in 164 horses. Assessments of LCAD were compared with those of RCAD. The LCAD:RCAD ratios in thickness and area were compared between control horses (resting grades 1 and 2) and horses with resting laryngeal grades 3 and 4 using the Havemeyer 4-point grading system with subgrades. The LCAD:RCAD ratios for thickness and area were 0.69 and 0.66 in horses with resting grades 3 and 4 respectively; LCAD was more hyperechogenic than RCAD in resting grades 3 and 4. LCAD:RCAD ratios for thickness and area in grades 3.II, 3.III and 4 were significantly lower than those in control horses. Thickness and area of the LCAD were negatively correlated with resting laryngeal grade MAIN LIMITATIONS: Overground endoscopy was not performed in this study. There were some differences in methodology: measurement of the physical thickness of the LCAD and clipping of hair at the laryngeal region were only performed in horses that underwent laryngoplasty. Results of ultrasonographic assessments of the CAD using transcutaneous ultrasonography were similar to those obtained by transoesophageal ultrasonography. This technique enables a simple, noninvasive, direct and easy examination. Assessment of the CAD using transcutaneous ultrasonography may be a useful technique and a potential option for determining whether to perform nerve graft or laryngoplasty.

Ultrasonographic findings associated with normal pregnancy and fetal well-being in the bottlenose dolphin (Tursiops truncatus).

Reproductive success is vital in sustaining free‐ranging and managed bottlenose dolphin (Tursiops truncatus) populations. Ultrasonography is an invaluable, non‐invasive tool in assessing the fetomaternal unit in humans and animals, including dolphins and horses. The purpose of this prospective longitudinal cohort study was to develop a protocol for fetomaternal ultrasonographic monitoring in dolphins and to report normal measurements and descriptive findings correlated with a positive outcome. From 2010 to 2017, serial ultrasonographic evaluations of 12 healthy dolphins were performed over the course of 16 pregnancies. A total of 203 ultrasound examinations were included in the study. Several metrics were accurate in predicting fetal age. Fetal biparietal diameter (BPD), thoracic width in dorsal and transverse planes, thoracic height in a sagittal plane, aortic diameter, and blubber thickness all demonstrated high correlation with gestational age (r > 0.94, P < .00001). Regional uteroplacental thickness significantly increased with each trimester (range 0.22–0.40 cm; P < .00011 cranial uterus, P < .00057 mid, and P < .000011 caudal). Lung:liver mean pixel intensity was 2.57 ± 0.46 (95% confidence interval 2.47‐2.67). Ultrasonographic characteristics of normal pregnancy in dolphins are described and an equation for prediction of parturition date in Tursiops is reported: days to parturition = 348.16 − (26.03 × BPD(cm)) (R 2 = 0.99). Future applications of these normal data will help identify in utero abnormalities indicative of fetal morbidity, and improve understanding of reproductive failure in wild and managed populations.

Digital Objects in Rhombic Dodecahedron Grid

Abstract Rhombic dodecahedron is a space filling polyhedron which represents the close packing of spheres in 3D space and the Voronoi structures of the face centered cubic (FCC) lattice. In this paper, we describe a new coordinate system where every 3-integer coordinates grid point corresponds to a rhombic dodecahedron centroid. In order to illustrate the interest of the new coordinate system, we propose the characterization of 3D digital plane with its topological features, such as the interrelation between the thickness of the digital plane and the separability constraint we aim to obtain. We also present the characterization of 3D digital lines and study it as the intersection of multiple digital planes. Characterization of 3D digital sphere with relevant topological features is proposed as well along with the 48-symmetry appearing in the new coordinate system.

Parametric study of integrity on the mechanical properties of transversely isotropic rock mass using DEM

The evaluation of the mechanical properties of a transversely isotropic rock mass is a challenging task in practical engineering. This paper aims to study the relationships between the integrity parameters and mechanical properties of a transversely isotropic rock mass. The rock mass quality designation (RQD) is an important index and reference for rock mass quality evaluation that was introduced to establish the numerical models of a jointed rock mass with different integrities. The numerical models of a transversely isotropic rock mass were established using the bonded particle model (BPM) and smooth joint model (SJM) embedded into the Particle Flow Code software (PFC2D). After calibrating the microscopic parameters of the intact rock and structural planes, a series of compression tests of a transversely isotropic rock mass was carried out to determine compressive strength and deformation modulus, and main factors were considered including the RQD, inclined angle of structural planes, structural plane thickness, structural plane properties, intact rock properties, and confining pressure. The experimental results showed that the mechanical parameters and failure modes of a transversely isotropic rock mass were controlled by the integrity parameters. By comparing the value of σcm/σc (ratio of the compressive strength of rock mass to rock mass) and Em/Er (ratio of the deformation modulus of rock mass to rock mass) with field test results, the results obtained from the discrete element method were demonstrated to be reasonable.

Accuracy of Presurgical Limited Field of View Cone-beam Computed Tomography in Predicting Intraoperative Buccal Cortical Bone

IntroductionLimited field of view cone-beam computed tomography (LFOV CBCT) is the primary imaging modality recommended for treatment planning before endodontic microsurgery (EMS). Persistent apical periodontitis, often treated with EMS, results in changes in the buccal cortical plate that may detrimentally impact prognosis. The accuracy of a preoperative LFOV CBCT to predict intraoperative findings is unclear. MethodsElectronic health records (EHRs) of EMS performed at 2 endodontic offices between 2016 and 2018 were reviewed retrospectively. EHR data extracted were documented for surgical findings of intact buccal cortical plate, fenestration, dehiscence, and height of remaining buccal collar of bone. Two calibrated, independent reviewers evaluated presurgical LFOV CBCTs in the multiplanar paraxial and parasagittal planes at 2 different reconstructed viewing plane thicknesses. Reviewer findings were compared with EHR documentation. Data were analyzed by using χ2, logistic regression, and multivariable analysis. Significance was set at P < .05. ResultsWithin the 125 EMS cases included in the study, the EHR prevalence of intact buccal cortical plate was 49%, dehiscence 7%, and fenestration 44%. The imaging predictive value, whether it was negative (NPV) or positive (PPV), was higher when predicting presence of buccal bone (PPV of intact buccal cortical plate = 86.5%; NPV of dehiscence = 96%; NPV of fenestration = 89%). Sensitivity and specificity ranged from 80%–90%. Accuracy in prediction was high for all variables, exceeding 80%. Accuracy was not significantly influenced by reconstructed viewing slice thickness, viewing plane, or reviewer. ConclusionPreoperative LFOV CBCT was highly discriminatory and accurately predicted intraoperative buccal cortical bone status, especially intact buccal cortical plate and fenestration.