Transverse Cross Section Research Articles

Sanitary Gravity Sewer Design using Sewer GEMS Software Connect Edition for Utsav Vihar, Karala

The paper presents modeling, design and analysis of sewage network of Utsav Vihar by means of Sewer GEMS software which helps in the achievement of project results in a shorter period of time in an effective way and at reasonable prices. In the present study the sewerage was designed for Utsav Vihar area in North – West Delhi District. Sewer GEMS software eases the designing for engineers because of unique features to offer a fully dynamic and multi-platform sanitary and combined sewer modeling solution which otherwise tends to consume a lot of time and energy. The software uses derived equations and theorems for calculating the hydraulic model. It enables engineers to analyze all sanitary and combined sewer networks in a single package. The hydraulic design section includes the calculation and determination of the transit, total flow and hydraulic modeling for network pipes diameters or slopes. The application generates reports, layouts, longitudinal or transverse cross section.

Glacial overdeepenings in the Swiss Alps and foreland: Spatial distribution and morphometrics

Overdeepenings (ODs) are erosional features that have been excavated below the regional sea/fluvial base level to produce closed topographic basins. Accessing bedrock topography and OD volume is often challenging. Hence, despite constituting major landscape features and being widespread in (paleo-)glaciated regions, ODs have been overlooked and the subglacial processes involved in their evolution have remained debated. In the Swiss Alpine foreland and valleys, ODs are commonly found filled with water or large volumes of sediment. Using a GIS-Matlab approach based on topographic datasets and bedrock contour-curves, we mapped the spatial distribution of ODs in Switzerland and adjacent areas in the ice-free Alpine areas. The majority of the mapped ODs occurs in very-low bedrock erosional resistance, where ODs are larger, wider and shallower than in medium to high bedrock erosional resistance domains, evidencing a strong lithological control on OD geometry. Longitudinal asymmetry and hypsometric integral suggest a dominance of quarrying during OD evolution and, for selected glacial catchments, headward erosion propagation or high sediment evacuation efficiency. OD surface data (surface and length) can be tentatively used for extracting OD subsurface metrics (depths, nested valleys and first-order volume estimates). Our data seem to indicate that ODs may initiate as multiple small nested valleys and progress to a single and connected depression. Transversal cross-sections also suggest a negative feedback between the erosion potential for deep carving and the presence of low-resistance bedrock, where subglacial meltwater infiltration could have played a key role in OD evolution. Although insightful relationships have been evidenced for ODs in the Swiss Alps and foreland, we have also observed a high spatial variability in key OD metrics such as surface area and depth. This results in general (first-order) interpretations at regional scale, but currently prevent to quantitatively constrain physical subglacial processes at their origin. Comparisons with existing OD datasets under present-day ice (Greenland, Antarctica and modern Swiss glaciers) place our results in a broader context and allow a step forward in our understanding of the complex patterns and mechanisms of (sub-)glacial erosion and resulting landforms.

Rotor blades as curved, twisted and tapered beam-like structures subjected to large deflections

Non-prismatic beam-like structures are widespread in many engineering and science applications. Important examples include the rotor blades of wind turbines and helicopters. Their mechanical behaviour can be simulated using 3D beam models, which are computationally efficient, accurate and explicitly consider such structures’ main geometric features, the large deflection of their reference centre-line and 3D warping of their transverse cross-sections. This paper proposes a mathematical model for such structures. A variational approach and the smallness of the warping and strain fields are exploited to obtain the model. Analytical and numerical results obtained with the proposed modelling approach are presented and compared to those from nonlinear 3D-FEM simulations.

Reproducibility of radiomics features derived from intravoxel incoherent motion diffusion-weighted MRI of cervical cancer.

The reproducibility of intravoxel incoherent motion (IVIM)-based radiomics studies in humans has not been reported. To determine the inter- and intra-observer variability on the reproducibility of IVIM-based radiomics features in cervical cancer (CC). The IVIM images of 25 patients with CC were retrospectively collected. Based on the high-resolution T2-weighted images, the regions of interest (ROIs) were independently delineated twice in diffusion-weighted images at a b value of 1000 s/mm2 (interval time was one month) by two radiologists. This was done at the largest transversal cross-sections of the tumors. The ROI was subsequently used in apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) maps derived from IVIM images. In total, 105 radiomics features were then finally extracted from the IVIM-derived maps. The inter- and intra-observer reproducibility of IVIM-derived features was then evaluated using the intraclass correlation coefficient. Inter- and intra-observer variability affected the reproducibility of radiomics features. D* map had 100% and 95% reproducible features, ADC map had 89% and 93%, D map had 97% and 86%, while f map had 54% and 62% reproducible features with good to excellent reliability in the intra-observer analysis. Similarly, D* map had 90% and 94%, ADC map had 85% and 70%, D map had 81% and 78%, while f map had 41% and 93% reproducible features with good to excellent reliability in the inter-observer analysis. Inter- and intra-observer variability can affect radiomics analysis. Cognizant to this, multicenter studies should pay more attention to intra- and inter-observer variability.

Ultrasound computed tomography on standing trees: accounting for wood anisotropy permits a more accurate detection of defects

Context: Ultrasound computed tomography is a suitable tool for nondestructive evaluation of standing trees. Until now, to simplify the image reconstruction process, the transverse cross-section of trees has been considered as quasi-isotropic and therefore limiting the defect identification capability. Aims: An approach to solve the inverse problem for tree imaging is presented, using an ultrasound-based method (travel-time computed tomography) suited to the anisotropy of wood material and validated experimentally. Methods: The proposed iterative method focused on finding a polynomial approximation of the slowness in each pixel of the image depending on the angle of propagation, modifying the curved trajectories by means of a raytracing method. This method allowed a mapping of specific elastic constants using nonlinear regression. Experimental validation was performed using sections of green wood from a pine tree (Pinus pinea L.), with configurations that include a healthy case, a centered, and an off-centered defect. Results: Images obtained using the proposed method led to a more accurate location of the defects compared to the filtered backprojection algorithm (isotropic hypothesis), considered as reference. Conclusion: The performed experiments demonstrated that considering the wood anisotropy in the imaging process led to a better defect detection compared to the use of a common imaging technique

A dynamic cutting force model for transverse orthogonal cutting of unidirectional carbon/carbon composites considering fiber distribution

Many unwanted defects such as burr and delamination can be induced due to the high cutting forces in the machining process of carbon/carbon (C/C) composites due to their brittle property. In this regard, it is necessary to predict the cutting force accurately in the machining of C/C composites. In this paper, a prediction model of dynamic cutting force in time domain is proposed for transverse orthogonal cutting of unidirectional C/C (UD-C/C) composites based on the energy method considering the random distribution of fibers and voids. Firstly, a microscopic representative volume element (MRVE) consisting of a single carbon fiber and its surrounding carbon matrix is introduced into this model, and its size varies with the distribution of fibers and voids. Then, the cutting force model of a MRVE is established considering the fiber orientation angle. Second, the representative volume element (RVE) of transverse cross section of UD-C/C composites is simulated mathematically with the random distribution of fibers and voids. The instantaneous resultant cutting force model in time domain is developed by integrating the cutting force of the in-cut MRVEs. The comparison of the predicted and experimental cutting forces shows a good agreement.

CHARACTERIZATION OF TITANIUM LASER WELDS

Butt welding of commercially pure titanium Grade 1 and Ti6Al4V alloy sheets using a pulsed Nd:YAG laser KLS 246 - 102 LASAG were carried out to determine optimal values of pulse energy and pulse length to create completely penetrated weld. Surface peak power density of about 3.105 W.cm−2 was found as an optimal value. Weld dimensions, both face width and penetration depth, are found to be proportional to increasing energy and decreasing pulse length. Gentle sagging and root penetration were revealed by means of contact surface profilometry. The nanohardness tests on transverse cross-sections detected approximately 50% higher hardness in the fusion zone than in the base material.

Shaping ion beams into hollow profiles using sextupole magnets

It is essential to properly shape the intensity distribution or irradiation field of high-energy charged-particle beams to improve their utilization, e.g., high energy density physics and heavy-ion fusion. Recently, unique beam profile shaping that cannot be realized through conventional linear focusing (i.e., the formation of hollow transverse profiles) was achieved through nonlinear focusing using octupole magnets. In this paper, we experimentally demonstrate hollow profile shaping using sextupole magnets, and numerically and analytically verify the beam dynamics of second-order sextupole focusing. We found that both triangular and elliptical-shaped hollow beams can be formed despite the three-fold symmetry of transverse beam cross-sections and asymmetric phase-space evolution. The characteristics of the sextupole-focused beams are compared with those of octupole-focused beams.

Investigation of electroproduction of ϕ mesons off protons

We investigate $\phi$-meson electroproduction off the proton target, i.e., $\gamma^* p \to \phi p$, by employing a tree-level effective Lagrangian approach in the kinematical ranges of $Q^2$ = (0$-$4) $\mathrm{GeV}^2$, $W$ = (2$-$5) GeV, and $|t| \leq 2\,\mathrm{GeV}^2$. In addition to the universally accepted Pomeron exchange, we consider various meson exchanges in the $t$ channel with the Regge method. Direct $\phi$-meson radiations in the $s$- and $u$-channels are also taken into account. We find that the $Q^2$ dependence of the transverse ($\sigma_{\mathrm{T}}$) and longitudinal ($\sigma_{\mathrm{L}}$) cross sections are governed by Pomeron and $(a_0,f_0)$ scalar meson exchanges, respectively. Meanwhile, the contributions of $(\pi,\eta)$ pseudoscalar- and $f_1(1285)$ axial-vector-meson exchanges are much more suppressed. The results of the interference cross sections ($\sigma_{\mathrm{LT}}, \sigma_{\mathrm{LT}}$) and the spin-density matrix elements indicate that $s$-channel helicity conservation holds at $Q^2$ = (1$-$4) $\mathrm{GeV}^2$. The result of the parity asymmetry yield $P \simeq 0.95$ at $W$ = 2.5 GeV, meaning that natural-parity exchange dominates the reaction process. Our numerical results are in fair agreement with the experimental data and thus the use of our effective Reggeized model is justified over the considered kinematical ranges of $Q^2$, $W$, and $t$.

Recombination effects in the ionization chambers dose delivery monitor of the TOP-IMPLART proton beam

The Intensity Modulated Proton Linear Accelerator for Cancer Therapy (TOP-IMPLART) is under development and construction by ENEA in collaboration with the Italian Institute of Health (ISS) and the Oncological Hospital Regina Elena-IFO with financial support of Regione Lazio.Its peculiar time structure (few microseconds pulse width) and very high peak intensity (≍ 109 proton/pulse) demand for ad hoc dose delivery monitors (DDM). The TOP-IMPLART DDM is based on ionization gas chambers. One segmented chamber prototype uses Micro Pattern Gaseous Detector technology for the 2-dimensional simultaneous x/y readout; the charge collected from each active segment (strips with pad-like shape) is readout by a dedicated gain-adaptable electronics. Two small, highly sensitive, integral ionization chambers, using the same electronics, complement the 2D chamber for the monitor of the single pulse beam charge, down to 1 pC/pulse.While under development and deployment of its accelerating modular cavities, the linear TOP-IMPLART beam is improved thanks also to the continuous monitoring and characterization by these devices, whose responses are periodically compared to calibrated dosimetric detectors such as real-time active microDiamond sensor, passive Alanine pellets, intrinsically stable integral Faraday Cup.Different calibration campaigns have been recently conducted to measure the recombination and dose-rate effects on the above ionization chambers. The outcome of these measurements shows clear electron-ion recombination in the chamber active volume, largely related to the high beam intensity and its small transverse cross section. Those effects can be taken into account and used to correct the actual measurement of the DDM.In this paper, the TOP-IMPLART project and the DDM devices are shortly presented and details of the above experimental studies are discussed.

Electron Acceleration by the E0n Wave in a Circular Waveguide in the Cyclotron Resonance Mode

A method for acceleration of electrons in a smooth cylindrical waveguide in the presence of the magnetic field of a solenoid is proposed. Electrons move in the waveguide along a helical trajectory that is shifted relative to the waveguide axis. Electrons are accelerated at the frequency of the cyclotron resonance along the waveguide axis by wave E01 or E02. It is shown that the acceleration results from synchronous rotation of particles in the transverse cross section of the waveguide and propagation of the wave along the waveguide axis. When the electric field reaches a maximum level and provides acceleration, electrons are located at the center of the waveguide. With a delay of one half of the period, the electric field provides deceleration and electrons are rotated by the magnetic field toward the wall of the waveguide to the region of lower deceleration. Acceleration is the total effect of the electron–field interaction over the period of electron rotation. Parameters of an accelerator are estimated for an energy of 10 MeV.

Quasi-3D Discretization of Thermal Hot-Spot Propagation in Superconducting Models

To deal with the multi-scale nature of the quench propagation problem in superconducting magnets, this work presents a quasi-three-dimensional (Q3D) approach combining a two-dimensional finite-element method (FEM) in the transversal cross-section of the magnet for resolving the geometrical details, with a one-dimensional spectral-element method based on orthogonal polynomials in longitudinal direction for accurately and efficiently representing the quench phenomena. The Q3D formulation is elaborated and the idea is illustrated on a thermal benchmark problem. Finally, the method is validated against a conventional 3D simulation carried out by a commercial software. In terms of computational efficiency, it is shown that the proposed Q3D approach is superior to the conventional 3D FEM.

Mixed-mode fracture response of anti-symmetric laminates: Experiments and modelling

Multidirectional laminates are very often used in advanced structures. However, the existing data in the literature regarding their fracture response is not conclusive. In this work, the fracture response of a +45∘//−45∘ interface is investigated under remote mixed mode loading and compared to a 0∘//0∘ layout. Several experiments were conducted under three mode mixities φ=0.15, 0.35 and 0.65 as well as pure modes I (φ=0) and II (φ=1.0) following the established standard procedures. Energy release rates were calculated using an appropriate reduced form of the J integral. Fracture toughness was independent of the interface at initiation but increased with mode mixity. Subsequent fracture resistance was negligible for the 0∘//0∘ layout, but increased significantly for the +45∘//−45∘ interface. Mechanistic investigations were carried out using X-ray computer tomography at 5 different load levels as well as transverse cross sections. The results showed lack of bridging in the case of 0∘//0∘ layout for all values of φ. For the +45∘//−45∘ interface, fracture was dominated by delamination, ply splitting and crack migration with their extent dependent upon φ. Numerical analyses based on the virtual crack closure technique demonstrated that the antisymmetric local fracture modes, interlaminar longitudinal shear vs. transverse shear, are responsible for delamination and crack migration, respectively. Based on the experimental observations, a mesoscale FE model was able to reproduce not only the failure mechanisms, i.e. delamination, transverse cracking and crack migration resulting in the zig-zag fracture pattern, but also give a reasonable approximation of the energy release rate obtained for each of the different mode mixities considered in this study.

An Asymptotic Approach to the Calculation of Wave Fields in a Layer with a Defect with a Small Characteristic Size

Problems about vibrations of an orthotropic layer with a cylindrical cavity with an arbitrary transverse cross section under the action of a load applied on its surface are considered. In the case of cavities with a small relative size, an asymptotic approach to the calculation of fields is proposed. An estimate of the applicability area of the asymptotic approach in comparison with the method of boundary integral equations, as well as a comparison with the solution obtained based on the Born approximation are presented.

Predicting Tensile Behaviour of Bulk Bamboo using Weibull Statistics for Progressive Failure

Bamboo is a natural composite material consisting of unidirectional fibre bundles, oriented along axial direction, embedded in soft parenchymatous matrix. The bundles are arranged such that the fibre density (or fibre volume fraction) varies from outer to inner periphery of bamboo shoot. The gradation in volume fraction of unidirectional fibre bundles qualifies bamboo as a typical radially graded transversely isotropic material. Being largely a cellulosic material, the fibre bundles have high tensile strength. However, there is great dispersion of these properties. In this work, an attempt is made to model the progressive failure of fibre bundles to predict the failure strength of bulk bamboo in uniaxial tension. A two-parameter Weibull distribution is proposed to analyse the strengths of fibre bundles having different cross-section areas. Tension tests are performed on fibre bundles, selected from different fibre density regions in the transverse cross-section of bamboo, for determining statistical parameters. The results highlight the close resemblance between the Weibull probability distribution of the experimental results on fibre bundles and overall mechanical behaviour of the bulk bamboo. Thus, the use of Weibull parameters is established for predicting the strength of bulk bamboo from fibre bundle testing of different cross-section areas.

Density Distribution in Wood of European Birch (Betula pendula Roth.)

The aim of the presented research is to perform a comprehensive analysis of wood density variability on the longitudinal and transverse cross-section of log trees at the age of 70 to 72 years of Betula pendula Roth. and the creation of density distribution maps. Furthermore, the determination proportion of juvenile and mature wood was done. Wood density was determined with a non-destructive method using an isotopic densimeter. It was found that the wood location, both in cross-section and longitudinal section of the trunk, had a statistically significant effect on the average density of birch wood. The average density of whole logs was significantly higher than the average density at the breast height. On the cross-section, the distribution of average densities determined at the breast height, as well as on ¼ of the log height, properly depicted the distribution of average densities on the cross-section determined for the whole logs. The geographical direction (north–south) did not have a statistically significant effect on the distribution of average densities on the cross-section of the tested birch logs.

FE Analyses of Hyperelastic Solids under Large Bending: The Role of the Searle Parameter and Eulerian Slenderness.

A theoretical model concerning the finite bending of a prismatic hyperelastic solid has been recently proposed. Such a model provides the 3D kinematics and the stress field, taking into account the anticlastic effects arising in the transverse cross sections also. That model has been used later to extend the Elastica in the framework of finite elasticity. In the present work, Finite Element (FE) analyses of some basic structural systems subjected to finite bending have been carried out and the results have been compared with those provided by the theoretical model performed previously. In the theoretical formulation, the governing equation is the nonlinear local relationship between the bending moment and the curvature of the longitudinal axis of the bent beam. Such a relation has been provided in dimensionless form as a function of the Mooney–Rivlin constitutive constants and two kinematic dimensionless parameters termed Eulerian slenderness and compactness index of the cross section. Such parameters take relevance as they are involved in the well-known Searle parameter for bent solids. Two significant study cases have been investigated in detail. The results point out that the theoretical model leads to reliable results provided that the Eulerian slenderness and the compactness index of the cross sections do not exceed fixed threshold values.

Computation of the Cutoff Wavenumbers of Metallic Waveguides with Symmetries by Using a Nonlinear Eigenproblem Formulation: A Group Theoretical Approach

The evaluation of the cutoff wavenumbers of metallic waveguides can be related to the numerical resolution of a suitable nonlinear eigenproblem defined on the domain C described by the contour of its transverse cross section. In this work, we show that the symmetries of C can be exploited to obtain a block diagonal matrix representation of the nonlinear eigenproblem, which enables a remarkable reduction in the computational effort involved in its resolution.

Exclusive production of ϕ meson in the γ*p→ϕp reaction at large photon virtualities within kT -factorization approach

We apply the $k_T$-factorization approach to the production of $\phi$ meson in deep-inelastic scattering. The helicity-conserving $\gamma^*(T,L) \to \phi$ impact factor is calculated for longitudinal and transverse photon polarization using $\phi$ meson distribution amplitudes. Different unintegrated gluon distributions are used in the calculations. The formalism for massless quarks/antiquarks gives too large transverse and longitudinal cross sections for photon virtualities below $Q^2\sim 8 \, \rm{GeV}^2$. We suggest how to improve the description of the HERA data by introducing effective strange quark masses into the formalism. We derive the corresponding massive impact factor by comparing to the light-cone wave function representation used in previous $k_T$-factorization calculations and the color-dipole approaches. As a byproduct we present expressions for higher twist-amplitudes as weighted integrals over the light-cone wave function. The quark mass $m_q \approx 0.5$ GeV allows to improve the description of both longitudinal and transverse cross section down to $Q^2 \sim$ 4 GeV$^2$. We present also the polarized cross section ratio $\sigma_L/\sigma_T$ and the behavior of the total cross section $\sigma_{tot} = \sigma_{L} + \sigma_{T}$ as a function of photon virtuality.

Modal Analysis of 2-D Material-Based Plasmonic Waveguides by Mixed Spectral Element Method With Equivalent Boundary Condition

Recently, atomically thin two-dimensional (2-D) materials have attracted significant attention due to their promising applications in optoelectronic devices. Among them, surface plasmon-polaritons (SPPs) stimulated by 2-D material-based waveguide provide a new mechanism to propagate and enhance lightwaves in the deep subwavelength. However, the modeling and simulation of the 2-D material-based structures are still a challenge due to the mismatch between their electrically small in thickness and electrically large in transversal cross-section. In order to obtain a high-efficiency modal analysis of 2-D material-based plasmonic waveguides, the mixed spectral element method (mixed-SEM) with surface current boundary condition (SCBC) is proposed in this paper. The new method introduces a variational formulation that combines the transversal vectorial Helmholtz equation with the Gauss' law, and a SCBC that is implemented as the equivalent boundary condition to eliminate 2-D nanoscale thin sheets from the computational domain. It thus avoids an enormous number of unknowns and significantly reduces the computational costs. To verify the proposed method, some typical 2-D material-based plasmonic waveguides including those composed of anisotropic black phosphorus are analyzed and numerical results are compared in various ways. Excellent agreements are obtained for all the cases which clearly suggest that the proposed method can efficiently and accurately simulate 2-D materials-based plasmonic waveguides.