Optimal locations and orientations of piezoelectric transducers on cylindrical shell based on gramians of contributed and undesired Rayleigh-Ritz modes using genetic algorithm

NASA Astrophysics Data System (ADS)

Biglar, Mojtaba; Mirdamadi, Hamid Reza; Danesh, Mohammad

2014-02-01

In this study, the active vibration control and configurational optimization of a cylindrical shell are analyzed by using piezoelectric transducers. The piezoelectric patches are attached to the surface of the cylindrical shell. The Rayleigh-Ritz method is used for deriving dynamic modeling of cylindrical shell and piezoelectric sensors and actuators based on the Donnel-Mushtari shell theory. The major goal of this study is to find the optimal locations and orientations of piezoelectric sensors and actuators on the cylindrical shell. The optimization procedure is designed based on desired controllability and observability of each contributed and undesired mode. Further, in order to limit spillover effects, the residual modes are taken into consideration. The optimization variables are the positions and orientations of piezoelectric patches. Genetic algorithm is utilized to evaluate the optimal configurations. In this article, for improving the maximum power and capacity of actuators for amplitude depreciation of negative velocity feedback strategy, we have proposed a new control strategy, called "Saturated Negative Velocity Feedback Rule (SNVF)". The numerical results show that the optimization procedure is effective for vibration reduction, and specifically, by locating actuators and sensors in their optimal locations and orientations, the vibrations of cylindrical shell are suppressed more quickly.

PANDA2: Program for Minimum Weight Design of Stiffened, Composite, Locally Buckled Panels

DTIC Science & Technology

1986-09-01

a flat panel or a panel that spans less than about 45 degrees of circumference. However, in PANDA2 complete cylindrical shells can be treated by the...compression and that corresponding to maximum in-plane shear. It is usually best to treat complete cylindrical shells in this way rather than try to set up a...to treat panels, not complete cylindrical shells. Therefore, it is best applied to panels. In PANDA2 the curved edges of a cylindrical panel lie in

Stability of cylindrical thin shell wormholes supported by MGCG in f(R) gravity

NASA Astrophysics Data System (ADS)

Eid, A.

2018-02-01

In the framework of f(R) modified theory of gravity, the dynamical equations of motion of a cylindrical thin shell wormholes supported by a modified generalized Chaplygin gas are constructed, using the cut and paste scheme (Darmois Israel formalism). The mechanical stability analysis of a cylindrical thin shell wormhole is discussed using a linearized radial perturbation around static solutions at the wormhole throat. The presence of stable static solutions depends on the suitable values of some parameters of dynamical shell.

On sound transmission into a stiffened cylindrical shell with rings and stringers treated as discrete elements

NASA Technical Reports Server (NTRS)

Koval, L. R.

1980-01-01

In the context of the transmission of airborne noise into an aircraft fuselage, a mathematical model is presented for the transmission of an oblique plane sound wave into a finite cylindrical shell stiffened by stringers and ring frames. The rings and stringers are modeled as discrete structural elements. The numerical case studied was typical of a narrow-bodied jet transport fuselage. The numerical results show that the ring-frequency dip in the transmission loss curve that is present for a monocoque shell is still present in the case of a stiffened shell. The ring frequency effect is a result of the cylindrical geometry of the shell. Below the ring frequency, stiffening does not appear to have any significant effect on transmission loss, but above the ring frequency, stiffeners can enhance the transmission loss of a cylindrical shell.

Free and Forced Vibrations of Thick-Walled Anisotropic Cylindrical Shells

NASA Astrophysics Data System (ADS)

Marchuk, A. V.; Gnedash, S. V.; Levkovskii, S. A.

2017-03-01

Two approaches to studying the free and forced axisymmetric vibrations of cylindrical shell are proposed. They are based on the three-dimensional theory of elasticity and division of the original cylindrical shell with concentric cross-sectional circles into several coaxial cylindrical shells. One approach uses linear polynomials to approximate functions defined in plan and across the thickness. The other approach also uses linear polynomials to approximate functions defined in plan, but their variation with thickness is described by the analytical solution of a system of differential equations. Both approaches have approximation and arithmetic errors. When determining the natural frequencies by the semi-analytical finite-element method in combination with the divide and conqure method, it is convenient to find the initial frequencies by the finite-element method. The behavior of the shell during free and forced vibrations is analyzed in the case where the loading area is half the shell thickness

Stress concentration factors for circular, reinforced penetrations in pressurized cylindrical shells. Ph.D. Thesis - Virginia Univ.

NASA Technical Reports Server (NTRS)

Ramsey, J. W., Jr.

1975-01-01

The effect on stresses in a cylindrical shell with a circular penetration subject to internal pressure was investigated in thin, shallow linearly, elastic cylindrical shells. Results provide numerical predictions of peak stress concentration factors around nonreinforced and reinforced penetrations in pressurized cylindrical shells. Analytical results were correlated with published formulas, as well as theoretical and experimental results. An accuracy study was made of the finite element program for each of the configurations considered important in pressure vessel technology. A formula is developed to predict the peak stress concentration factor for analysis and/or design in conjunction with the ASME Boiler and Pressure Vessel Code.

A circumferential crack in a cylindrical shell under tension.

NASA Technical Reports Server (NTRS)

Duncan-Fama, M. E.; Sanders, J. L., Jr.

1972-01-01

A closed cylindrical shell under uniform internal pressure has a slit around a portion of its circumference. Linear shallow shell theory predicts inverse square-root-type singularities in certain of the stresses at the crack tips. This paper reports the computed strength of these singularities for different values of a dimensionless parameter based on crack length, shell radius and shell thickness.

Buckling of Cracked Laminated Composite Cylindrical Shells Subjected to Combined Loading

NASA Astrophysics Data System (ADS)

Allahbakhsh, Hamidreza; Shariati, Mahmoud

2013-10-01

A series of finite element analysis on the cracked composite cylindrical shells under combined loading is carried out to study the effect of loading condition, crack size and orientation on the buckling behavior of laminated composite cylindrical shells. The interaction buckling curves of cracked laminated composite cylinders subject to different combinations of axial compression, bending, internal pressure and external pressure are obtained, using the finite element method. Results show that the internal pressure increases the critical buckling load of the CFRP cylindrical shells and bending and external pressure decrease it. Numerical analysis show that axial crack has the most detrimental effect on the buckling load of a cylindrical shell and results show that for lower values of the axial compressive load and higher values of the external pressure, the buckling is usually in the global mode and for higher values of axial compressive load and lower levels of external pressure the buckling mode is mostly in the local mode.

Calculation of load distribution in stiffened cylindrical shells

NASA Technical Reports Server (NTRS)

Ebner, H; Koller, H

1938-01-01

Thin-walled shells with strong longitudinal and transverse stiffening (for example, stressed-skin fuselages and wings) may, under certain simplifying assumptions, be treated as static systems with finite redundancies. In this report the underlying basis for this method of treatment of the problem is presented and a computation procedure for stiffened cylindrical shells with curved sheet panels indicated. A detailed discussion of the force distribution due to applied concentrated forces is given, and the discussion illustrated by numerical examples which refer to an experimentally determined circular cylindrical shell.

Sound Transmission through a Cylindrical Sandwich Shell with Honeycomb Core

NASA Technical Reports Server (NTRS)

Tang, Yvette Y.; Robinson, Jay H.; Silcox, Richard J.

1996-01-01

Sound transmission through an infinite cylindrical sandwich shell is studied in the context of the transmission of airborne sound into aircraft interiors. The cylindrical shell is immersed in fluid media and excited by an oblique incident plane sound wave. The internal and external fluids are different and there is uniform airflow in the external fluid medium. An explicit expression of transmission loss is derived in terms of modal impedance of the fluids and the shell. The results show the effects of (a) the incident angles of the plane wave; (b) the flight conditions of Mach number and altitude of the aircraft; (c) the ratios between the core thickness and the total thickness of the shell; and (d) the structural loss factors on the transmission loss. Comparisons of the transmission loss are made among different shell constructions and different shell theories.

Integrated reactor and centrifugal separator and uses thereof

DOEpatents

Birdwell, Jr., Joseph F; Jennings, Harold L [Clinton, TN; McFarlane, Joanna [Oak Ridge, TN; Tsouris, Constantino [Oak Ridge, TN

2012-01-17

An apparatus for providing reaction of fluids and separation of products with increased residence time. The apparatus includes a stationary shell, a rotating hollow cylindrical component disposed in the stationary shell, a residence-time increasing device external to the stationary shell, a standpipe for introducing fluid into an interior cavity of the hollow cylindrical component from the residence-time increasing device, a first outlet in fluid flow communication with the interior cavity of the hollow cylindrical component for a less dense phase fluid, and a second outlet in fluid flow communication with the interior cavity of the hollow cylindrical component for a more dense phase fluid.

Propagation of flexural and membrane waves with fluid loaded NASTRAN plate and shell elements

NASA Technical Reports Server (NTRS)

Kalinowski, A. J.; Wagner, C. A.

1983-01-01

Modeling of flexural and membrane type waves existing in various submerged (or in vacuo) plate and/or shell finite element models that are excited with steady state type harmonic loadings proportioned to e(i omega t) is discussed. Only thin walled plates and shells are treated wherein rotary inertia and shear correction factors are not included. More specifically, the issue of determining the shell or plate mesh size needed to represent the spatial distribution of the plate or shell response is of prime importance towards successfully representing the solution to the problem at hand. To this end, a procedure is presented for establishing guide lines for determining the mesh size based on a simple test model that can be used for a variety of plate and shell configurations such as, cylindrical shells with water loading, cylindrical shells in vacuo, plates with water loading, and plates in vacuo. The procedure for doing these four cases is given, with specific numerical examples present only for the cylindrical shell case.

Fractal dimension study of polaron effects in cylindrical GaAs/Al x Ga1- x As core-shell nanowires

NASA Astrophysics Data System (ADS)

Sun, Hui; Li, Hua; Tian, Qiang

2018-04-01

Polaron effects in cylindrical GaAs/Al x Ga1- x As core-shell nanowires are studied by applying the fractal dimension method. In this paper, the polaron properties of GaAs/Al x Ga1- x As core-shell nanowires with different core radii and aluminum concentrations are discussed. The polaron binding energy, polaron mass shift, and fractal dimension parameter are numerically determined as functions of shell width. The calculation results reveal that the binding energy and mass shift of the polaron first increase and then decrease as the shell width increases. A maximum value appears at a certain shell width for different aluminum concentrations and a given core radius. By using the fractal dimension method, polaron problems in cylindrical GaAs/Al x Ga1- x As core-shell nanowires are solved in a simple manner that avoids complex and lengthy calculations.

Effects of Shell-Buckling Knockdown Factors in Large Cylindrical Shells

NASA Technical Reports Server (NTRS)

Hrinda, Glenn A.

2012-01-01

Shell-buckling knockdown factors (SBKF) have been used in large cylindrical shell structures to account for uncertainty in buckling loads. As the diameter of the cylinder increases, achieving the manufacturing tolerances becomes increasingly more difficult. Knockdown factors account for manufacturing imperfections in the shell geometry by decreasing the allowable buckling load of the cylinder. In this paper, large-diameter (33 ft) cylinders are investigated by using various SBKF's. An investigation that is based on finite-element analysis (FEA) is used to develop design sensitivity relationships. Different manufacturing imperfections are modeled into a perfect cylinder to investigate the effects of these imperfections on buckling. The analysis results may be applicable to large- diameter rockets, cylindrical tower structures, bulk storage tanks, and silos.

Vibration suppression of a piezo-equipped cylindrical shell in a broad-band frequency domain

NASA Astrophysics Data System (ADS)

Loghmani, Ali; Danesh, Mohammad; Kwak, Moon K.; Keshmiri, Mehdi

2017-12-01

This paper focuses on the dynamic modeling of a cylindrical shell equipped with piezoceramic sensors and actuators, as well as the design of a broad band multi-input and multi-output linear quadratic Gaussian controller for the suppression of vibrations. The optimal locations of actuators are derived by Genetic Algorithm (GA) to effectively control the specific structural modes of the cylinder. The dynamic model is derived based on the Sanders shell theory and the energy approach for both the cylinder and the piezoelectric transducers, all of which reflect the piezoelectric effect. The natural vibration characteristics of the cylindrical shell are investigated both theoretically and experimentally. The theoretical predictions are in good agreement with the experimental results. Then, the broad band multi-input and multi-output linear quadratic Gaussian controller was designed and applied to the test article. An active vibration control experiment is carried out on the cylindrical shell and the digital control system is used to implement the proposed control algorithm. The experimental results show that vibrations of the cylindrical shell can be suppressed by the piezoceramic sensors and actuators along with the proposed controller. The optimal location of the actuators makes the proposed control system more efficient than other configurations.

46 CFR 52.01-3 - Definitions of terms used in this part.

Code of Federal Regulations, 2010 CFR

2010-10-01

... shells, attached by riveting, bolting, or welding. They generally consist of a cylindrical shell with one... plain furnace is a cylindrical shell usually made in sections joined by means of riveting or welding... longitudinal joint, the ends being attached by riveting or welding. Their purpose is to provide additional...

46 CFR 52.01-3 - Definitions of terms used in this part.

Code of Federal Regulations, 2011 CFR

2011-10-01

... shells, attached by riveting, bolting, or welding. They generally consist of a cylindrical shell with one... plain furnace is a cylindrical shell usually made in sections joined by means of riveting or welding... longitudinal joint, the ends being attached by riveting or welding. Their purpose is to provide additional...

Stress concentration in a cylindrical shell containing a circular hole.

NASA Technical Reports Server (NTRS)

Adams, N. J. I.

1971-01-01

The state of stress in a cylindrical shell containing a circular cutout was determined for axial tension, torsion, and internal pressure loading. The solution was obtained for the shallow shell equations by a variational method. The results were expressed in terms of a nondimensional curvature parameter which was a function of shell radius, shell thickness, and hole radius. The function chosen for the solution was such that when the radius of the cylindrical shell approaches infinity, the flat-plate solution was obtained. The results are compared with solutions obtained by more rigorous analytical methods, and with some experimental results. For small values of the curvature parameter, the agreement is good. For higher values of the curvature parameter, the present solutions indicate a limiting value of stress concentration, which is in contrast to previous results.

Dynamics of Inhomogeneous Shell Systems Under Non-Stationary Loading (Survey)

NASA Astrophysics Data System (ADS)

Lugovoi, P. Z.; Meish, V. F.

2017-09-01

Experimental works on the determination of dynamics of smooth and stiffened cylindrical shells contacting with a soil medium under various non-stationary loading are reviewed. The results of studying three-layer shells of revolution whose motion equations are obtained within the framework of the hypotheses of the Timoshenko geometrically nonlinear theory are stated. The numerical results for shells with a piecewise or discrete filler enable the analysis of estimation of the influence of geometrical and physical-mechanical parameters of structures on their dynamics and reveal new mechanical effects. Basing on the classical theory of shells and rods, the effect of the discrete arrangement of ribs and coefficients of the Winkler or Pasternak elastic foundation on the normal frequencies and modes of rectangular planar cylindrical and spherical shells is studied. The number and shape of dispersion curves for longitudinal harmonic waves in a stiffened cylindrical shell are determined. The equations of vibrations of ribbed shells of revolution on Winkler or Pasternak elastic foundation are obtained using the geometrically nonlinear theory and the Timoshenko hypotheses. On applying the integral-interpolational method, numerical algorithms are developed and the corresponding non-stationary problems are solved. The special attention is paid to the statement and solution of coupled problems on the dynamical interaction of cylindrical or spherical shells with the soil water-saturated medium of different structure.

Explosive shock damage potential in space structures

NASA Technical Reports Server (NTRS)

Mortimer, R. W.

1972-01-01

The effects of a pulse shape on the transient response of a cylindrical shell are presented. Uniaxial, membrane, and bending theories for isotropic shells were used in this study. In addition to the results of the analytical study, the preliminary results of an experimental study into the generation and measurement of shear waves in a cylindrical shell are included.

Numerical Simulation of the Layer-Bylayer Destruction of Cylindrical Shells Under Explosive Loading

NASA Astrophysics Data System (ADS)

Abrosimov, N. A.; Novoseltseva, N. A.

2015-09-01

A technique of numerical analysis of the influence of reinforcement structure on the nature of the dynamic response and the process of layer-by-layer destruction of layered fiberglass cylindrical shells under an axisymmetric internal explosive loading is elaborated. The kinematic model of deformation of the laminate package is based on a nonclassical theory of shells. The geometric dependences are based on simple quadratic relations of the nonlinear theory of elasticity. The relationship between the stress and strain tensors are established by using Hooke's law for orthotropic bodies with account of degradation of stiffness characteristics of the multilayer composite due to the local destruction of some its elementary layers. An energetically consistent system of dynamic equations for composite cylindrical shells is obtained by minimizing the functional of total energy of the shell as a three-dimensional body. The numerical method for solving the formulated initial boundary-value problem is based on an explicit variational-difference scheme. Results confirming the reliability of the method used to analyze the influence of reinforcement structure on the character of destruction and the bearing capacity of pulse-loaded cylindrical shells are presented.

A technique for generating shear waves in cylindrical shells under radial impact

NASA Technical Reports Server (NTRS)

Blum, A.; Mortimer, R. W.; Rose, J. L.

1974-01-01

Experimental techniques are developed to study and measure the shear-wave velocity in an aluminum cylindrical shell subjected to a radial impact. The radial impact is obtained by exploding an electrical detonator inserted in plastic plugs mounted on the end of the shell. Strain gages, mounted on the outside surface of the shell at various axial locations, are used to obtain oscilloscope traces from which the shear-wave velocity can be calculated.

Subwavelength core/shell cylindrical nanostructures for novel plasmonic and metamaterial devices

NASA Astrophysics Data System (ADS)

Kim, Kyoung-Ho; No, You-Shin

2017-12-01

In this review, we introduce novel plasmonic and metamaterial devices based on one-dimensional subwavelength nanostructures with cylindrical symmetry. Individual single devices with semiconductor/metal core/shell or dielectric/metal core/multi-shell structures experience strong light-matter interaction and yield unique optical properties with a variety of functions, e.g., invisibility cloaking, super-scattering/super-absorption, enhanced luminescence and nonlinear optical activities, and deep subwavelength-scale optical waveguiding. We describe the rational design of core/shell cylindrical nanostructures and the proper choice of appropriate constituent materials, which allow the efficient manipulation of electromagnetic waves and help to overcome the limitations of conventional homogeneous nanostructures. The recent developments of bottom-up synthesis combined with the top-down fabrication technologies for the practical applications and the experimental realizations of 1D subwavelength core/shell nanostructure devices are briefly discussed.

Analysis of shear buckling of cylindrical shells. II - Effects of combined loadings

NASA Astrophysics Data System (ADS)

Kokubo, Kunio; Nagashima, Hideaki; Takayanagi, Masaaki; Madokoro, Manabu; Mochizuki, Akira; Ikeuchi, Hisaaki

1992-03-01

Cylindrical shells subjected to lateral loads buckle in shear or bending buckling modes. The effects of combined loadings are investigated by developing a special-purpose FEM program using the 8-node isoparametric shell element. Three types of loading, lateral and axial loads, and pure bending moments are considered. For short cylindrical shells, shear buckling modes are dominant, but elephant-foot bulges take place with an increase in bending moments. Effects of axial loads on shear buckling and the elephant-foot bulge are investigated. In the case of shear buckling the axial load affects the buckling mode as well as the buckling load. For bending bucklings, the axial loads have a great effect on the buckling load.

Analysis of thin-walled cylindrical composite shell structures subject to axial and bending loads: Concept development, analytical modeling and experimental verification

NASA Astrophysics Data System (ADS)

Mahadev, Sthanu

Continued research and development efforts devoted in recent years have generated novel avenues towards the advancement of efficient and effective, slender laminated fiber-reinforced composite members. Numerous studies have focused on the modeling and response characterization of composite structures with particular relevance to thin-walled cylindrical composite shells. This class of shell configurations is being actively explored to fully determine their mechanical efficacy as primary aerospace structural members. The proposed research is targeted towards formulating a composite shell theory based prognosis methodology that entails an elaborate analysis and investigation of thin-walled cylindrical shell type laminated composite configurations that are highly desirable in increasing number of mechanical and aerospace applications. The prime motivation to adopt this theory arises from its superior ability to generate simple yet viable closed-form analytical solution procedure to numerous geometrically intense, inherent curvature possessing composite structures. This analytical evaluative routine offers to acquire a first-hand insight on the primary mechanical characteristics that essentially govern the behavior of slender composite shells under typical static loading conditions. Current work exposes the robustness of this mathematical framework via demonstrating its potential towards the prediction of structural properties such as axial stiffness and bending stiffness respectively. Longitudinal ply-stress computations are investigated upon deriving the global stiffness matrix model for composite cylindrical tubes with circular cross-sections. Additionally, this work employs a finite element based numerical technique to substantiate the analytical results reported for cylindrically shaped circular composite tubes. Furthermore, this concept development is extended to the study of thin-walled, open cross-sectioned, curved laminated shells that are geometrically distinguished with respect to the circumferential arc angle, thickness-to-mean radius ratio and total laminate thickness. The potential of this methodology is challenged to analytically determine the location of the centroid. This precise location dictates the decoupling of extension-bending type deformational response in tension loaded composite structures. Upon the cross-validation of the centroidal point through the implementation of an ANSYS based finite element routine, influence of centroid is analytically examined under the application of a concentrated longitudinal tension and bending type loadings on a series of cylindrical shells characterized by three different symmetric-balanced stacking sequences. In-plane ply-stresses are computed and analyzed across the circumferential contour. An experimental investigation has been incorporated via designing an ad-hoc apparatus and test-up that accommodates the quantification of in-plane strains, computation of ply-stresses and addresses the physical characteristics for a set of auto-clave fabricated cylindrical shell articles. Consequently, this work is shown to essentially capture the mechanical aspects of cylindrical shells, thus facilitating structural engineers to design and manufacture viable structures.

Dynamic strength of cylindrical fiber-glass shells and basalt plastic shells under multiple explosive loading

NASA Astrophysics Data System (ADS)

Syrunin, M. A.; Fedorenko, A. G.

2006-08-01

We have shown experimentally that, for cylindrical shells made of oriented fiberglass platic and basalt plastic there exists a critical level of deformations, at which a structure sustains a given number of explosions from the inside. The magnitude of critical deformation for cylindrical fiberglass shells depends linearly on the logarithm of the number of loads that cause failure. For a given type of fiberglass, there is a limiting level of explosive action, at which the number of loads that do not lead to failure can be sufficiently large (more than ˜ 102). This level is attained under loads, which are an order of magnitude lower than the limiting loads under a single explosive action. Basalt plastic shells can be repeatedly used even at the loads, which cause deformation by ˜ 30-50% lower than the safe value ˜ 3.3.5% at single loading.

Research on soundproof properties of cylindrical shells of generalized phononic crystals

NASA Astrophysics Data System (ADS)

Liu, Ru; Shu, Haisheng; Wang, Xingguo

2017-04-01

Based on the previous studies, the concept of generalized phononic crystals (GPCs) is further introduced into the cylindrical shell structures in this paper. And a type of cylindrical shells of generalized phononic crystals (CS-GPCs) is constructed, the structural field and acoustic-structural coupled field of the composite cylindrical shells are examined respectively. For the structural field, the transfer matrix method of mechanical state vector is adopted to build the transfer matrix of radial waves propagating from inside to outside. For the acoustic-structural coupled field, the expressions of the acoustic transmission/reflection coefficients and the sound insulation of acoustic waves with the excitation of center line sound source are set up. And the acoustic transmission coefficient and the frequency response of sound insulation in this mode were numerical calculated. Furthermore, the theoretical analysis results are verified by using the method of combining the numerical calculation and finite element simulation. Finally, the effects of inner and outer fluid parameters on the transmission/reflection coefficients of CS-GPCs are analyzed in detail.

Acoustic radiation from the submerged circular cylindrical shell treated with active constrained layer damping

NASA Astrophysics Data System (ADS)

Yuan, Li-Yun; Xiang, Yu; Lu, Jing; Jiang, Hong-Hua

2015-12-01

Based on the transfer matrix method of exploring the circular cylindrical shell treated with active constrained layer damping (i.e., ACLD), combined with the analytical solution of the Helmholtz equation for a point source, a multi-point multipole virtual source simulation method is for the first time proposed for solving the acoustic radiation problem of a submerged ACLD shell. This approach, wherein some virtual point sources are assumed to be evenly distributed on the axial line of the cylindrical shell, and the sound pressure could be written in the form of the sum of the wave functions series with the undetermined coefficients, is demonstrated to be accurate to achieve the radiation acoustic pressure of the pulsating and oscillating spheres respectively. Meanwhile, this approach is proved to be accurate to obtain the radiation acoustic pressure for a stiffened cylindrical shell. Then, the chosen number of the virtual distributed point sources and truncated number of the wave functions series are discussed to achieve the approximate radiation acoustic pressure of an ACLD cylindrical shell. Applying this method, different radiation acoustic pressures of a submerged ACLD cylindrical shell with different boundary conditions, different thickness values of viscoelastic and piezoelectric layer, different feedback gains for the piezoelectric layer and coverage of ACLD are discussed in detail. Results show that a thicker thickness and larger velocity gain for the piezoelectric layer and larger coverage of the ACLD layer can obtain a better damping effect for the whole structure in general. Whereas, laying a thicker viscoelastic layer is not always a better treatment to achieve a better acoustic characteristic. Project supported by the National Natural Science Foundation of China (Grant Nos. 11162001, 11502056, and 51105083), the Natural Science Foundation of Guangxi Zhuang Autonomous Region, China (Grant No. 2012GXNSFAA053207), the Doctor Foundation of Guangxi University of Science and Technology, China (Grant No. 12Z09), and the Development Project of the Key Laboratory of Guangxi Zhuang Autonomous Region, China (Grant No. 1404544).

Computer Modeling of the Dynamic Strength of Metal-Plastic Cylindrical Shells Under Explosive Loading

NASA Astrophysics Data System (ADS)

Abrosimov, N. A.; Novosel'tseva, N. A.

2017-05-01

A technique for numerically analyzing the dynamic strength of two-layer metal-plastic cylindrical shells under an axisymmetric internal explosive loading is developed. The kinematic deformation model of the layered package is based on a nonclassical theory of shells. The geometric relations are constructed using relations of the simplest quadratic version of the nonlinear elasticity theory. The stress and strain tensors in the composite macrolayer are related by Hooke's law for an orthotropic body with account of degradation of the stiffness characteristics of the multilayer package due to local failure of some its elementary layers. The physical relations in the metal layer are formulated in terms of a differential theory of plasticity. An energy-correlated resolving system of dynamic equations for the metal-plastic cylindrical shells is derived by minimizing the functional of total energy of the shells as three-dimensional bodies. The numerical method for solving the initial boundary-value problem formulated is based on an explicit variational-difference scheme. The reliability of the technique considered is verified by comparing numerical results with experimental data. An analysis of the ultimate strains and strength of one-layer basalt-and glass-fiber-reinforced plastic and two-layer metalplastic cylindrical shells is carried out.

Visualization of the energy flow for guided forward and backward waves in and around a fluid-loaded elastic cylindrical shell via the Poynting vector field

NASA Astrophysics Data System (ADS)

Dean, Cleon E.; Braselton, James P.

2004-05-01

Color-coded and vector-arrow grid representations of the Poynting vector field are used to show the energy flow in and around a fluid-loaded elastic cylindrical shell for both forward- and backward-propagating waves. The present work uses a method adapted from a simpler technique due to Kaduchak and Marston [G. Kaduchak and P. L. Marston, ``Traveling-wave decomposition of surface displacements associated with scattering by a cylindrical shell: Numerical evaluation displaying guided forward and backward wave properties,'' J. Acoust. Soc. Am. 98, 3501-3507 (1995)] to isolate unidirectional energy flows.

Elastoplastic State of an Elliptical Cylindrical Shell with a Circular Hole

NASA Astrophysics Data System (ADS)

Storozhuk, E. A.; Chernyshenko, I. S.; Pigol', O. V.

2017-11-01

Static problems for an elastoplastic elliptical cylindrical shell with a circular hole are formulated and a numerical method for solving it is developed. The basic equations are derived using the Kirchhoff-Love theory of deep shells and the theory of small elastoplastic strains. The method employs the method of additional stresses and the finite-element method. The influence of plastic strains and geometrical parameters of the shell subject to internal pressure on the distributions of stresses, strains, and displacements in the zone of their concentration is studied.

Nonlinear Deformation and Stability of a Noncircular Cylindrical Shell Under Combined Loading with Bending and Twisting Moments

NASA Astrophysics Data System (ADS)

Belov, V. K.; Zheleznov, L. P.; Ognyanova, T. S.

2018-03-01

A previously developed technique is used to solve problems of strength and stability of discretely reinforced noncircular cylindrical shells made of a composite material with allowance for the moments and nonlinearity of their subcritical stress-strain state. Stability of a reinforced bay of the aircraft fuselage made of a composite material under combined loading with bending and twisting moments is studied. The effects of straining nonlinearity, stiffness of longitudinal ribs, and shell thickness on the critical loads that induce shell buckling are analyzed.

Vibrations of a thin cylindrical shell stiffened by rings with various stiffness

NASA Astrophysics Data System (ADS)

Nesterchuk, G. A.

2018-05-01

The problem of vibrations of a thin-walled elastic cylindrical shell reinforced by frames of different rigidity is investigated. The solution for the case of the clamped shell edges was obtained by asymptotic methods and refined by the finite element method. Rings with zero eccentricity and stiffness varying along the generatrix of the shell cylinder are considered. Varying the optimal coefficients of the distribution functions of the rigidity of the frames and finding more precise parameters makes it possible to find correction factors for analytical formulas of approximate calculation.

An Accurate Theory and Simple Fourth Order Governing Equations for Orthotropic and Composite Cylindrical Shells.

DTIC Science & Technology

1983-10-01

following basic equations can be deduced for orthotropic circular cylindrical shells. Let a be the radius of the midsurface of the shell, x, y, z the...axial, circumferential and radial coordinates and a, a the dimensionless midsurface coordinates along lines of curvatures (a - , a - . The threea a...8217The components of strain at an arbitrary point of the shell are related to the midsurface displacements by [8,15,16] e ( 1 v , 3 2w e a a a ,2)- 0 a

Free vibrations of a multilayered non-circular cylindrical shell

NASA Astrophysics Data System (ADS)

Zelinskaya, Anna V.

2018-05-01

Free vibrations of an elastic non-circular cylindrical shell of intermediate length are considered. The shell is assumed heterogeneous in the thickness direction, in its part it may be multilayered. In order to derive the equations of stability, we use the Timoshenko-Reissner model. According to it, a shell that is heterogeneous can be replaced by a homogeneous shell with the equivalent bending and transversal shear stiffness. We obtain the approximate asymptotic formula for a frequency that takes into account an influence of a transversal shear and a variability of a directrix curvature. As an example, a three-layer elliptical shell with hinged edges and a soft middle layer is analyzed.

Finite Element Analysis of Geodesically Stiffened Cylindrical Composite Shells Using a Layerwise Theory

NASA Technical Reports Server (NTRS)

Gerhard, Craig Steven; Gurdal, Zafer; Kapania, Rakesh K.

1996-01-01

Layerwise finite element analyses of geodesically stiffened cylindrical shells are presented. The layerwise laminate theory of Reddy (LWTR) is developed and adapted to circular cylindrical shells. The Ritz variational method is used to develop an analytical approach for studying the buckling of simply supported geodesically stiffened shells with discrete stiffeners. This method utilizes a Lagrange multiplier technique to attach the stiffeners to the shell. The development of the layerwise shells couples a one-dimensional finite element through the thickness with a Navier solution that satisfies the boundary conditions. The buckling results from the Ritz discrete analytical method are compared with smeared buckling results and with NASA Testbed finite element results. The development of layerwise shell and beam finite elements is presented and these elements are used to perform the displacement field, stress, and first-ply failure analyses. The layerwise shell elements are used to model the shell skin and the layerwise beam elements are used to model the stiffeners. This arrangement allows the beam stiffeners to be assembled directly into the global stiffness matrix. A series of analytical studies are made to compare the response of geodesically stiffened shells as a function of loading, shell geometry, shell radii, shell laminate thickness, stiffener height, and geometric nonlinearity. Comparisons of the structural response of geodesically stiffened shells, axial and ring stiffened shells, and unstiffened shells are provided. In addition, interlaminar stress results near the stiffener intersection are presented. First-ply failure analyses for geodesically stiffened shells utilizing the Tsai-Wu failure criterion are presented for a few selected cases.

Free Vibrations of Nonthin Elliptic Cylindrical Shells of Variable Thickness

NASA Astrophysics Data System (ADS)

Grigorenko, A. Ya.; Efimova, T. L.; Korotkikh, Yu. A.

2017-11-01

The problem of the free vibrations of nonthin elliptic cylindrical shells of variable thickness under various boundary conditions is solved using the refined Timoshenko-Mindlin theory. To solve the problem, an effective numerical approach based on the spline-approximation and discrete-orthogonalization methods is used. The effect of the cross-sectional shape, thickness variation law, material properties, and boundary conditions on the natural frequency spectrum of the shells is analyzed.

Periodic buckling of constrained cylindrical elastic shells

NASA Astrophysics Data System (ADS)

Marthelot, Joel; Brun, Pierre-Thomas; Lopez Jimenez, Francisco; Reis, Pedro M.

We revisit the classic problem of buckling of a thin cylindrical elastic shell loaded either by pneumatic depressurization or axial compression. The control of the resulting dimpled pattern is achieved by using a concentric inner rigid mandrel that constrains and stabilizes the post-buckling response. Under axial compression, a regular lattice of diamond-like dimples appears sequentially on the surface of the shell to form a robust spatially extended periodic pattern. Under pressure loading, a periodic array of ridges facets the surface of the elastic cylindrical shell. The sharpness of these ridges can be readily varied and controlled through a single scalar parameter, the applied pressure. A combination of experiments, simulations and scaling analyses is used to rationalize the combined role of geometry and mechanics in the nucleation and evolution of the diamond-like dimples and ridges networks.

Frequency dependence of the acoustic radiation force acting on absorbing cylindrical shells.

PubMed

Mitri, Farid G

2005-02-01

The frequency dependence of the radiation force function Y(p) for absorbing cylindrical shells suspended in an inviscid fluid in a plane incident sound field is analysed, in relation to the thickness and the content of their interior hollow region. The theory is modified to include the effect of hysteresis type absorption of compressional and shear waves in the material. The results of numerical calculations are presented for two viscoelastic (lucite and phenolic polymer) materials, with the hollow region filled with water or air indicating how damping and change of the interior fluid inside the shell's hollow region affect the acoustic radiation force. The acoustic radiation force acting on cylindrical lucite shells immersed in a high density fluid (in this case mercury) and filled with water in their hollow region, is also studied.

Modelling of Folding Patterns in Flat Membranes and Cylinders by Origami

NASA Astrophysics Data System (ADS)

Nojima, Taketoshi

This paper describes folding methods of thin flat sheets as well as cylindrical shells by modelling folding patterns through Japanese traditional Origami technique. New folding patterns have been devised in thin flat squared or circular membrane by modifying so called Miura-Ori in Japan (one node with 4 folding lines). Some folding patterns in cylindrical shells have newly been developed including spiral configurations. Devised foldable cylindrical shells were made by using polymer sheets, and it has been assured that they can be folded quite well. The devised models will make it possible to construct foldable/deployable space structures as well as to manufacture foldable industrial products and living goods, e. g., bottles for soft drinks.

Photoionization cross section and binding energy of single dopant in hollow cylindrical core/shell quantum dot

NASA Astrophysics Data System (ADS)

Feddi, E.; El-Yadri, M.; Dujardin, F.; Restrepo, R. L.; Duque, C. A.

2017-02-01

In this study, we have investigated the confined donor impurity in a hollow cylindrical-shell quantum dot. The charges are assumed to be completely confined to the interior of the shell with rigid walls. Within the framework of the effective-mass approximation and by using a simple variational approach, we have computed the donor binding energy as a function of the shell sizes in order to study the behavior of the electron-impurity attraction for a very small thickness. Our results show that the binding energy of a donor impurity placed at the center of cylindrical core/shell dots depends strongly on the shell size. The binding energy increases when the shell-wideness becomes smaller and shows the same behavior as in a simple cylindrical quantum dot. A special case has been studied, which corresponds to the ratio between the inner and outer radii near to one (a/b → 1) for which our model gives a non-significant behavior of the impurity binding energy. This fact implies the existence of a critical value (a/b) for which the binding energy of the donor impurity tends to the limit value of 4 effective Rydbergs as in a 2D quantum well. We also analyse the photoionization cross section considering only the in-plane incident radiation polarization. We determine its behavior as a function of photon energy, shell size, and donor position. The measurement of photoionization in such systems would be of great interest to understand the optical properties of carriers in quantum dots.

Obstetric outcomes for women with female genital mutilation at an Australian hospital, 2006-2012: a descriptive study.

PubMed

Varol, Nesrin; Dawson, Angela; Turkmani, Sabera; Hall, John J; Nanayakkara, Susie; Jenkins, Greg; Homer, Caroline S E; McGeechan, Kevin

2016-10-28

Women, who have been subjected to female genital mutilation (FGM), can suffer serious and irreversible physical, psychological and psychosexual complications. They have more adverse obstetric outcomes as compared to women without FGM. Exploratory studies suggest radical change to abandonment of FGM by communities after migration to countries where FGM is not prevalent. Women who had been subjected to FGM as a child in their countries of origin, require specialised healthcare to reduce complications and further suffering. Our study compared obstetric outcomes in women with FGM to women without FGM who gave birth in a metropolitan Australian hospital with expertise in holistic FGM management. The obstetric outcomes of one hundred and ninety-six women with FGM who gave birth between 2006 and 2012 at a metropolitan Australian hospital were analysed. Comparison was made with 8852 women without FGM who gave birth during the same time period. Data were extracted from a database specifically designed for women with FGM and managed by midwives specialised in care of these women, and a routine obstetric database, ObstetriX. The accuracy of data collection on FGM was determined by comparing these two databases. All women with FGM type 3 were deinfibulated antenatally or during labour. The outcome measures were (1) maternal: accuracy and grade of FGM classification, caesarean section, instrumental birth, episiotomy, genital tract trauma, postpartum blood loss of more than 500 ml; and (2) neonatal: low birth weight, admission to a special care nursery, stillbirth. The prevalence of FGM in women who gave birth at the metropolitan hospital was 2 to 3 %. Women with FGM had similar obstetric outcomes to women without FGM, except for statistically significant higher risk of first and second degree perineal tears, and caesarean section. However, none of the caesarean sections were performed for FGM indications. The ObstetriX database was only 35 % accurate in recording the correct FGM type. Women with FGM had similar obstetric outcomes to women without FGM in an Australian metropolitan hospital with expertise in FGM management. Specialised FGM services with clinical practice guideline and education of healthcare professionals may increase the detection rate of FGM and improve obstetric management of women with FGM.

Design and Fabrication of a Ring-Stiffened Graphite-Epoxy Corrugated Cylindrical Shell

NASA Technical Reports Server (NTRS)

Johnson, R., Jr.

1978-01-01

Design and fabrication of supplement test panels that represent key portions of the cylinder are described, as are supporting tests of coupons, sample joints, and stiffening ring elements. The cylindrical shell is a ring-stiffened, open corrugation design that uses T300/5208 graphite-epoxy tape as the basic material for the shell wall and stiffening rings. The test cylinder is designed to withstand bending loads producing the relatively low maximum load intensity in the shell wall of 1,576 N/cm. The resulting shell wall weight, including stiffening rings and fasteners, is 0.0156 kg/m. The shell weight achieved in the graphite-epoxy cylinder represents a weight saving of approximately 23 percent, compared to a comparable aluminum shell. A unique fabrication approach was used in which the cylinder wall was built in three flat segments, which were then wrapped to the cylindrical shape. Such an approach, made possible by the flexibility of the thin corrugated wall in a radial direction, proved to be a simple approach to building the test cylinder. Based on tooling and fabrication methods in this program, the projected costs of a production run of 100 units are reported.

Multi-parameter optimization of piezoelectric actuators for multi-mode active vibration control of cylindrical shells

NASA Astrophysics Data System (ADS)

Hu, K. M.; Li, Hua

2018-07-01

A novel technique for the multi-parameter optimization of distributed piezoelectric actuators is presented in this paper. The proposed method is designed to improve the performance of multi-mode vibration control in cylindrical shells. The optimization parameters of actuator patch configuration include position, size, and tilt angle. The modal control force of tilted orthotropic piezoelectric actuators is derived and the multi-parameter cylindrical shell optimization model is established. The linear quadratic energy index is employed as the optimization criterion. A geometric constraint is proposed to prevent overlap between tilted actuators, which is plugged into a genetic algorithm to search the optimal configuration parameters. A simply-supported closed cylindrical shell with two actuators serves as a case study. The vibration control efficiencies of various parameter sets are evaluated via frequency response and transient response simulations. The results show that the linear quadratic energy indexes of position and size optimization decreased by 14.0% compared to position optimization; those of position and tilt angle optimization decreased by 16.8%; and those of position, size, and tilt angle optimization decreased by 25.9%. It indicates that, adding configuration optimization parameters is an efficient approach to improving the vibration control performance of piezoelectric actuators on shells.

Asymptotic approximations for pure bending of thin cylindrical shells

NASA Astrophysics Data System (ADS)

Coman, Ciprian D.

2017-08-01

A simplified partial wrinkling scenario for in-plane bending of thin cylindrical shells is explored by using several asymptotic strategies. The eighth-order boundary eigenvalue problem investigated here originates in the Donnel-Mushtari-Vlasov shallow shell theory coupled with a linear membrane pre-bifurcation state. It is shown that the corresponding neutral stability curve is amenable to a detailed asymptotic analysis based on the method of multiple scales. This is further complemented by an alternative WKB approximation that provides comparable information with significantly less effort.

Analysis of thermal stresses and metal movement during welding

NASA Technical Reports Server (NTRS)

Muraki, T.; Pattee, F. M.; Masubuchi, K.

1974-01-01

Finite element computer programs were developed to determine thermal stresses and metal movement during butt welding of flat plates and bead-on-plate welding along the girth of a cylindrical shell. Circular cylindrical shells of 6061 aluminum alloy were used for the tests. Measurements were made of changes in temperature and thermal strains during the welding process.

Hole size, location optimization in a plate and cylindrical shell for minimum stress points interfacing ANSYS and MATLAB

NASA Astrophysics Data System (ADS)

Thangavel, Soundararaj

Discontinuities in Structures are inevitable. One such discontinuity in a plate and cylindrical shell is presence of a hole / holes. In Plates they are used for mounting bolts where as in Cylinder / Pressure Vessel, they provide provision for mounting Nozzles / Instruments. Location of these holes plays a primary role in minimizing the stress acting with out any external reinforcement. In this Thesis work, Location Parameters are optimized for the presence of one or more holes in a plate and cylindrical shell interfacing ANSYS and MATLAB with boundary constraints based on the geometry. Contour plots are generated for understanding stress distribution and analytical solutions are also discussed for some of the classical problems.

Response of moderately thick laminated cross-ply composite shells subjected to random excitation

NASA Technical Reports Server (NTRS)

Elishakoff, Isaak; Cederbaum, Gabriel; Librescu, Liviu

1989-01-01

This study deals with the dynamic response of transverse shear deformable laminated shells subjected to random excitation. The analysis encompasses the following problems: (1) the dynamic response of circular cylindrical shells of finite length excited by an axisymmetric uniform ring loading, stationary in time, and (2) the response of spherical and cylindrical panels subjected to stationary random loadings with uniform spatial distribution. The associated equations governing the structural theory of shells are derived upon discarding the classical Love-Kirchhoff (L-K) assumptions. In this sense, the theory is formulated in the framework of the first-order transverse shear deformation theory (FSDT).

Buckling of pressure-loaded, long, shear deformable, cylindrical laminated shells

NASA Astrophysics Data System (ADS)

Anastasiadis, John S.; Simitses, George J.

A higher-order shell theory was developed (kinematic relations, constitutive relations, equilibrium equations and boundary conditions), which includes initial geometric imperfections and transverse shear effects for a laminated cylindrical shell under the action of pressure, axial compression and in-plane shear. Through the perturbation technique, buckling equations are derived for the corresponding 'perfect geometry' symmetric laminated configuration. Critical pressures are computed for very long cylinders for several stacking sequences, several radius-to-total-thickness ratios, three lamina materials (boron/epoxy, graphite/epoxy, and Kevlar/epoxy), and three shell theories: classical, first-order shear deformable and higher- (third-)order shear deformable. The results provide valuable information concerning the applicability (accurate prediction of buckling pressures) of the various shell theories.

Buckling and Failure of Compression-loaded Composite Cylindrical Shells with Reinforced Cutouts

NASA Technical Reports Server (NTRS)

Hilburger, Mark W.; Nemeth, Michael P.

2005-01-01

Results from a numerical and experimental study that illustrate the effects of selected cutout reinforcement configurations on the buckling and failure response of compression-loaded composite cylindrical shells with a cutout are presented. The effects of reinforcement size, thickness, and orthotropy on the overall response of compression-loaded shells are described. In general, reinforcement around a cutout in a compression-loaded shell can retard or eliminate the local buckling response and material failure near the cutout and increase the buckling load of the shell. However, some results show that certain reinforcement configurations can cause a significant increase in the local interlaminar failures that can accumulate near the free edges of a cutout during a local buckling event.

Eigenvalue computations with the QUAD4 consistent-mass matrix

NASA Technical Reports Server (NTRS)

Butler, Thomas A.

1990-01-01

The NASTRAN user has the option of using either a lumped-mass matrix or a consistent- (coupled-) mass matrix with the QUAD4 shell finite element. At the Sixteenth NASTRAN Users' Colloquium (1988), Melvyn Marcus and associates of the David Taylor Research Center summarized a study comparing the results of the QUAD4 element with results of other NASTRAN shell elements for a cylindrical-shell modal analysis. Results of this study, in which both the lumped-and consistent-mass matrix formulations were used, implied that the consistent-mass matrix yielded poor results. In an effort to further evaluate the consistent-mass matrix, a study was performed using both a cylindrical-shell geometry and a flat-plate geometry. Modal parameters were extracted for several modes for both geometries leading to some significant conclusions. First, there do not appear to be any fundamental errors associated with the consistent-mass matrix. However, its accuracy is quite different for the two different geometries studied. The consistent-mass matrix yields better results for the flat-plate geometry and the lumped-mass matrix seems to be the better choice for cylindrical-shell geometries.

Female genital mutilation/cutting: will it continue?

PubMed

Mohammed, Ghada F; Hassan, Magdy M; Eyada, Moustafa M

2014-11-01

Female genital mutilation/cutting (FGM/C) is a prevalent, deeply rooted traditional practice in Egypt. Specification of the motives behind the continuation of FGM/C in Egyptian community and evaluation of the sexual function in women with FGM/C. This cross-sectional study, involved 2,106 sexually active female participants with FGM/C. Full history-taking and general examination to evaluate the type of FGM/C were conducted. Sexual function was assessed by using the Female Sexual Function Index (FSFI) questionnaire. Enumerate and specify the motivational factors and its percent among the participants. The correlation between FGM/C and FSFI domain scores was done with Pearson's correlation. Tradition, cleanliness, and virginity were the most common motives empowering the continuation of FGM/C (100%), followed by men's wish, esthetic factors, marriage, and religion factors (45.2-100%). Type I FGM/C was the most common, followed by type II. There was only negative correlation between the type II FGM/C and sexual satisfaction. No statistically significant difference between type I and non-FGM/C was found. FGM/C remains high. A variety of socio-cultural myths, religious misbelievers, and hygienic and esthetic concerns were behind the FGM/C. Overall, a large proportion of the participants supported the continuation of FGM/C in spite of adverse effect and sexual dysfunction associated with FGM/C. © 2014 International Society for Sexual Medicine.

Vibration Power Flow In A Constrained Layer Damping Cylindrical Shell

NASA Astrophysics Data System (ADS)

Wang, Yun; Zheng, Gangtie

2012-07-01

In this paper, the vibration power flow in a constrained layer damping (CLD) cylindrical shell using wave propagation approach is investigated. The dynamic equations of the shell are derived with the Hamilton principle in conjunction with the Donnell shell assumption. With these equations, the dynamic responses of the system under a line circumferential cosine harmonic exciting force is obtained by employing the Fourier transform and the residue theorem. The vibration power flows inputted to the system and transmitted along the shell axial direction are both studied. The results show that input power flow varies with driving frequency and circumferential mode order, and the constrained damping layer can obviously restrict the exciting force from inputting power flow into the base shell especially for a thicker viscoelastic layer, a thicker or stiffer constraining layer (CL), and a higher circumferential mode order, can rapidly attenuate the vibration power flow transmitted along the base shell axial direction.

Female Genital Mutilation in Sierra Leone: Forms, Reliability of Reported Status, and Accuracy of Related Demographic and Health Survey Questions

PubMed Central

Grant, Donald S.; Berggren, Vanja

2013-01-01

Objective. To determine forms of female genital mutilation (FGM), assess consistency between self-reported and observed FGM status, and assess the accuracy of Demographic and Health Surveys (DHS) FGM questions in Sierra Leone. Methods. This cross-sectional study, conducted between October 2010 and April 2012, enrolled 558 females aged 12–47 from eleven antenatal clinics in northeast Sierra Leone. Data on demography, FGM status, and self-reported anatomical descriptions were collected. Genital inspection confirmed the occurrence and extent of cutting. Results. All participants reported FGM status; 4 refused genital inspection. Using the WHO classification of FGM, 31.7% had type Ib; 64.1% type IIb; and 4.2% type IIc. There was a high level of agreement between reported and observed FGM prevalence (81.2% and 81.4%, resp.). There was no correlation between DHS FGM responses and anatomic extent of cutting, as 2.7% reported pricking; 87.1% flesh removal; and 1.1% that genitalia was sewn closed. Conclusion. Types I and II are the main forms of FGM, with labia majora alterations in almost 5% of cases. Self-reports on FGM status could serve as a proxy measurement for FGM prevalence but not for FGM type. The DHS FGM questions are inaccurate for determining cutting extent. PMID:24204384

Observation of Compressible Plasma Mix in Cylindrically Convergent Implosions

NASA Astrophysics Data System (ADS)

Barnes, Cris W.; Batha, Steven H.; Lanier, Nicholas E.; Magelssen, Glenn R.; Tubbs, David L.; Dunne, A. M.; Rothman, Steven R.; Youngs, David L.

2000-10-01

An understanding of hydrodynamic mix in convergent geometry will be of key importance in the development of a robust ignition/burn capability on NIF, LMJ and future pulsed power machines. We have made use of the OMEGA laser facility at the University of Rochester to investigate directly the mix evolution in a convergent geometry, compressible plasma regime. The experiments comprise a plastic cylindrical shell imploded by direct laser irradiation. The cylindrical shell surrounds a lower density plastic foam which provides sufficient back pressure to allow the implosion to stagnate at a sufficiently high radius to permit quantitative radiographic diagnosis of the interface evolution near turnaround. The susceptibility to mix of the shell-foam interface is varied by choosing different density material for the inner shell surface (thus varying the Atwood number). This allows the study of shock-induced Richtmyer-Meshkov growth during the coasting phase, and Rayleigh-Taylor growth during the stagnation phase. The experimental results will be described along with calculational predictions using various radiation hydrodynamics codes and turbulent mix models.

Buckling of circular cylindrical shells under dynamically applied axial loads

NASA Technical Reports Server (NTRS)

Tulk, J. D.

1972-01-01

A theoretical and experimental study was made of the buckling characteristics of perfect and imperfect circular cylindrical shells subjected to dynamic axial loading. Experimental data included dynamic buckling loads (124 data points), high speed photographs of buckling mode shapes and observations of the dynamic stability of shells subjected to rapidly applied sub-critical loads. A mathematical model was developed to describe the dynamic behavior of perfect and imperfect shells. This model was based on the Donnell-Von Karman compatibility and equilibrium equations and had a wall deflection function incorporating five separate modes of deflection. Close agreement between theory and experiment was found for both dynamic buckling strength and buckling mode shapes.

Influence of an asymmetric ring on the modeling of an orthogonally stiffened cylindrical shell

NASA Technical Reports Server (NTRS)

Rastogi, Naveen; Johnson, Eric R.

1994-01-01

Structural models are examined for the influence of a ring with an asymmetrical cross section on the linear elastic response of an orthogonally stiffened cylindrical shell subjected to internal pressure. The first structural model employs classical theory for the shell and stiffeners. The second model employs transverse shear deformation theories for the shell and stringer and classical theory for the ring. Closed-end pressure vessel effects are included. Interacting line load intensities are computed in the stiffener-to-skin joints for an example problem having the dimensions of the fuselage of a large transport aircraft. Classical structural theory is found to exaggerate the asymmetric response compared to the transverse shear deformation theory.

Coupled mixed-field laminate theory and finite element for smart piezoelectric composite shell structures

NASA Technical Reports Server (NTRS)

Saravanos, Dimitris A.

1996-01-01

Mechanics for the analysis of laminated composite shells with piezoelectric actuators and sensors are presented. A new mixed-field laminate theory for piezoelectric shells is formulated in curvilinear coordinates which combines single-layer assumptions for the displacements and a layerwise representation for the electric potential. The resultant coupled governing equations for curvilinear piezoelectric laminates are described. Structural mechanics are subsequently developed and an 8-node finite-element is formulated for the static and dynamic analysis of adaptive composite structures of general laminations containing piezoelectric layers. Evaluations of the method and comparisons with reported results are presented for laminated piezoelectric-composite plates, a closed cylindrical shell with a continuous piezoceramic layer and a laminated composite semi-circular cantilever shell with discrete cylindrical piezoelectric actuators and/or sensors.

Analysis of transient, linear wave propagation in shells by the finite difference method

NASA Technical Reports Server (NTRS)

Geers, T. L.; Sobel, L. H.

1971-01-01

The applicability of the finite difference method to propagation problems in shells, and the response of a cylindrical shell with cutouts to both longitudinal and radial transient excitations are investigated. It is found that the only inherent limitation of the finite difference method is its inability to reproduce accurately response discontinuities. The short wave length limitations of thin shell theory create significant convergence difficulties may often be overcome through proper selection of finite difference mesh dimensions and temporal or spatial smoothing of the excitation. Cutouts produce moderate changes in early and intermediate time response of a cylindrical shell to axisymmetric pulse loads applied at one end. The cutouts may facilitate the undesirable late-time transfer of load-injected extensional energy into nonaxisymmetric flexural response.

An exploration of attitudes towards female genital mutilation (FGM) in men and women accessing FGM clinical services in London: a pilot study.

PubMed

Larsson, Martina; Cohen, Pollyanna; Hann, Gayle; Creighton, Sarah M; Hodes, Deborah

2018-03-21

This pilot study researched the attitudes towards and the knowledge of female genital mutilation (FGM) in adult women with FGM and their partners. The participant population consisted of English-speaking women and men over 18 years old attending specialist FGM clinics in two London hospitals. The participants completed a questionnaire on the attitudes and the knowledge of FGM, which were adapted with permission from the United Nations Children's Fund and the United States Agency for International Development household surveys. 54 participants (51 women, 3 men) took part in the surveys. 89% of participants thought that FGM should be stopped (95%CI: 0.81-0.97) and 72% said they knew FGM is illegal in the United Kingdom (UK). 15% reported that FGM caused no danger, or were unaware of any danger to women's health. This study demonstrates the opposition to FGM by participants, but some lack of knowledge regarding the legal and health implications. The exploration of attitudes in diaspora community groups is often cited as key to safeguarding girls from FGM. This is one of the first UK studies of individuals from FGM-practising communities, and we recommend use of the study questionnaires for a multicentre, cross-community study. Impact statement What is already known about this subject? Women and children are affected by female genital mutilation (FGM) globally and in the United Kingdom (UK). The majority of knowledge on practices and the attitudes towards FGM comes from UNICEF and USAID research in Africa and there is scant data on FGM practices in diaspora communities in the UK. What do the results of this study add? This study provides an appropriate questionnaire and protocol for use in community-based national research to improve healthcare for women by collecting up-to-date data on the attitudes towards FGM among the members of FGM-practising communities in the UK. What are the implications of these findings for clinical practice and further research? The implications of the results of this study are that health professionals need to understand that patients do not always know the law on FGM, even after a consultation. Health and social care professionals are placed in a unique position to work with community members to educate men and women to end FGM.

Geographic Variation and Factors Associated with Female Genital Mutilation among Reproductive Age Women in Ethiopia: A National Population Based Survey

PubMed Central

Setegn, Tesfaye; Lakew, Yihunie; Deribe, Kebede

2016-01-01

Background Female genital mutilation (FGM) is a common traditional practice in developing nations including Ethiopia. It poses complex and serious long-term health risks for women and girls and can lead to death. In Ethiopia, the geographic distribution and factors associated with FGM practices are poorly understood. Therefore, we assessed the spatial distribution and factors associated with FGM among reproductive age women in the country. Method We used population based national representative surveys. Data from two (2000 and 2005) Ethiopian demographic and health surveys (EDHS) were used in this analysis. Briefly, EDHS used a stratified, two-stage cluster sampling design. A total of 15,367 (from EDHS 2000) and 14,070 (from EDHS 2005) women of reproductive age (15–49 years) were included in the analysis. Three outcome variables were used (prevalence of FGM among women, prevalence of FGM among daughters and support for the continuation of FGM). The data were weighted and descriptive statistics (percentage change), bivariate and multivariable logistic regression analyses were carried out. Multicollinearity of variables was assessed using variance inflation factors (VIF) with a reference value of 10 before interpreting the final output. The geographic variation and clustering of weighted FGM prevalence were analyzed and visualized on maps using ArcGIS. Z-scores were used to assess the statistical difference of geographic clustering of FGM prevalence spots. Result The trend of FGM weighted prevalence has been decreasing. Being wealthy, Muslim and in higher age categories are associated with increased odds of FGM among women. Similarly, daughters from Muslim women have increased odds of experiencing FGM. Women in the higher age categories have increased odds of having daughters who experience FGM. The odds of FGM among daughters decrease with increased maternal education. Mass media exposure, being wealthy and higher paternal and maternal education are associated with decreased odds of women’s support of FGM continuation. FGM prevalence and geographic clustering showed variation across regions in Ethiopia. Conclusion Individual, economic, socio-demographic, religious and cultural factors played major roles in the existing practice and continuation of FGM. The significant geographic clustering of FGM was observed across regions in Ethiopia. Therefore, targeted and integrated interventions involving religious leaders in high FGM prevalence spot clusters and addressing the socio-economic and geographic inequalities are recommended to eliminate FGM. PMID:26741488

Geographic Variation and Factors Associated with Female Genital Mutilation among Reproductive Age Women in Ethiopia: A National Population Based Survey.

PubMed

Setegn, Tesfaye; Lakew, Yihunie; Deribe, Kebede

2016-01-01

Female genital mutilation (FGM) is a common traditional practice in developing nations including Ethiopia. It poses complex and serious long-term health risks for women and girls and can lead to death. In Ethiopia, the geographic distribution and factors associated with FGM practices are poorly understood. Therefore, we assessed the spatial distribution and factors associated with FGM among reproductive age women in the country. We used population based national representative surveys. Data from two (2000 and 2005) Ethiopian demographic and health surveys (EDHS) were used in this analysis. Briefly, EDHS used a stratified, two-stage cluster sampling design. A total of 15,367 (from EDHS 2000) and 14,070 (from EDHS 2005) women of reproductive age (15-49 years) were included in the analysis. Three outcome variables were used (prevalence of FGM among women, prevalence of FGM among daughters and support for the continuation of FGM). The data were weighted and descriptive statistics (percentage change), bivariate and multivariable logistic regression analyses were carried out. Multicollinearity of variables was assessed using variance inflation factors (VIF) with a reference value of 10 before interpreting the final output. The geographic variation and clustering of weighted FGM prevalence were analyzed and visualized on maps using ArcGIS. Z-scores were used to assess the statistical difference of geographic clustering of FGM prevalence spots. The trend of FGM weighted prevalence has been decreasing. Being wealthy, Muslim and in higher age categories are associated with increased odds of FGM among women. Similarly, daughters from Muslim women have increased odds of experiencing FGM. Women in the higher age categories have increased odds of having daughters who experience FGM. The odds of FGM among daughters decrease with increased maternal education. Mass media exposure, being wealthy and higher paternal and maternal education are associated with decreased odds of women's support of FGM continuation. FGM prevalence and geographic clustering showed variation across regions in Ethiopia. Individual, economic, socio-demographic, religious and cultural factors played major roles in the existing practice and continuation of FGM. The significant geographic clustering of FGM was observed across regions in Ethiopia. Therefore, targeted and integrated interventions involving religious leaders in high FGM prevalence spot clusters and addressing the socio-economic and geographic inequalities are recommended to eliminate FGM.

A robust approach for analysing dispersion of elastic waves in an orthotropic cylindrical shell

NASA Astrophysics Data System (ADS)

Kaplunov, J.; Nobili, A.

2017-08-01

Dispersion of elastic waves in a thin orthotropic cylindrical shell is considered, within the framework of classical 2D Kirchhoff-Love theory. In contrast to direct multi-parametric analysis of the lowest propagating modes, an alternative robust approach is proposed that simply requires evaluation of the evanescent modes (quasi-static edge effect), which, at leading order, do not depend on vibration frequency. A shortened dispersion relation for the propagating modes is then derived by polynomial division and its accuracy is numerically tested against the full Kirchhoff-Love dispersion relation. It is shown that the same shortened relation may be also obtained from a refined dynamic version of the semi-membrane theory for cylindrical shells. The presented results may be relevant for modelling various types of nanotubes which, according to the latest experimental findings, possess strong material anisotropy.

A cylindrical shell with an arbitrarily oriented crack

NASA Technical Reports Server (NTRS)

Yahsi, O. S.; Erdogan, F.

1982-01-01

The general problem of a shallow shell with constant curvatures is considered. It is assumed that the shell contains an arbitrarily oriented through crack and the material is specially orthotropic. The nonsymmetric problem is solved for arbitrary self equilibrating crack surface tractions, which, added to an appropriate solution for an uncracked shell, would give the result for a cracked shell under most general loading conditions. The problem is reduced to a system of five singular integral equations in a set of unknown functions representing relative displacements and rotations on the crack surfaces. The stress state around the crack tip is asymptotically analyzed and it is shown that the results are identical to those obtained from the two dimensional in plane and antiplane elasticity solutions. The numerical results are given for a cylindrical shell containing an arbitrarily oriented through crack. Some sample results showing the effect of the Poisson's ratio and the material orthotropy are also presented.

Numerical Determination of Natural Frequencies and Modes of the Vibrations of a Thick-Walled Cylindrical Shell

NASA Astrophysics Data System (ADS)

Grigorenko, A. Ya.; Borisenko, M. Yu.; Boichuk, E. V.; Prigoda, A. P.

2018-01-01

The dynamic characteristics of a thick-walled cylindrical shell are determined numerically using the finite-element method implemented with licensed FEMAR software. The natural frequencies and modes are compared with those obtained earlier experimentally by the method of stroboscopic holographic interferometry. Frequency coefficients demonstrating how the natural frequency depends on the physical and mechanical parameters of the material are determined.

A Variational Method for Calculating the Natural Frequencies and Mode Shapes of a Cantilevered Open Cylindrical Shell.

DTIC Science & Technology

1983-12-01

A + f( (n xNxx Nx)6u + (nxNx 9 Nee)Sv )ds (19) s w1 where n are defined as the direction cosines between the normal and the y direction. To integrate...of a specific shell shape. Thus far, Eq (27) applies to all cylindrical shells with the only assumption being the thickness, h, is small as com - pared...results. For instance, after solving Eq (32) for its eight roots, one of them must be established as X1. While this choice is com - pletely arbitrary at

Female Genital Mutilation/Cutting among Women of Somali and Kurdish Origin in Finland.

PubMed

Koukkula, Mimmi; Keskimäki, Ilmo; Koponen, Päivikki; Mölsä, Mulki; Klemetti, Reija

2016-09-01

The tradition of female genital mutilation/cutting (FGM/C) has spread in Europe as a result of immigration. Although it is known to have negative health impacts, the exact prevalence of FGM/C and its health effects in Finland are unknown. This study explores the prevalence of FGM/C, the sociodemographic characteristics associated with it, and its health effects among women of Somali and Kurdish origin in Finland. Data were obtained from the Migrant Health and Well Being Study carried out in 2010-2012. This study uses data from interviews with Somali (N = 165) and Kurdish origin (N = 224) women. The participation rate was 37 percent for Somali and 54 percent for Kurdish origin women. The prevalence of FGM/C was 69 percent among those of Somali origin and 32 percent among those of Kurdish origin. Having no education and older age were significantly associated with FGM/C, as was marriage amongst women of Somali origin, and the practice of Islam among women of Kurdish origin. Reporting good self-perceived health was more common among women without FGM/C. Outpatient visits to medical doctors were less common among women of Somali origin with FGM/C, compared with women without FGM/C. About 26 percent of Somali origin and 39 percent of Kurdish origin women with FGM/C reported reproductive or other health problems because of FGM/C. FGM/C is more common in Finland than previously assumed, particularly among women of Kurdish origin. Women with FGM/C need improved access to culturally competent health services to address the health impacts of FGM/C. Education and outreach to immigrant communities to prevent future FGM/C are also urgently needed. © 2016 Wiley Periodicals, Inc.

Female genital mutilation reversal: a general approach.

PubMed

Anand, Mallika; Stanhope, Todd J; Occhino, John A

2014-07-01

Female genital mutilation (FGM) is a violation of human rights; yet, more than 100 million females are estimated to have undergone the procedure worldwide. There is an increased need for physician education in treating FGM. Female pelvic surgeons have a unique opportunity to treat this population of patients. Here, we depict the classification of FGM and a general approach to FGM reversal. We specifically address the procedure of type III FGM reversal, or defibulation. In this video, we first highlight the importance of the problem of FGM. Next, we present the classification of FGM using an original, simple, schematic diagram highlighting they key anatomic structures involved in the four types of FGM. We then present a simple case of reversal of type III FGM, a procedure also known as defibulation. After depicting the surgical procedure, we discuss clinical results and summarize key principles of the defibulation procedure. Our patient was a 25-year-old woman who had undergone type III FGM as a child in Somalia. She desired restoration of vaginal function. We performed a reversal, and her postoperative course was uncomplicated. By 6 weeks postoperatively, she was able to engage in sexual intercourse without dyspareunia. FGM is a problem at the doorsteps of female pelvic medicine and reconstructive surgery. Our video demonstrates a basic surgical approach that can be applied to simple cases of type III FGM presenting to the female pelvic surgeon.

46 CFR 59.15-10 - Bagged or blistered shell plates.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Bagged or blistered shell plates. 59.15-10 Section 59.15... shell plates. (a) When the shell plates of cylindrical boilers which are exposed to the radiant heat of... boiler. (b) Where the shell plate is bagged due to overheating, the Officer in Charge, Marine Inspection...

46 CFR 59.15-10 - Bagged or blistered shell plates.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Bagged or blistered shell plates. 59.15-10 Section 59.15... shell plates. (a) When the shell plates of cylindrical boilers which are exposed to the radiant heat of... boiler. (b) Where the shell plate is bagged due to overheating, the Officer in Charge, Marine Inspection...

Application of the line-spring model to a cylindrical shell containing a circumferential or axial part-through crack

NASA Technical Reports Server (NTRS)

Delale, F.; Erdogan, F.

1982-01-01

The line-spring model developed by Rice and Levy (1972) is used to obtain an approximate solution for a cylindrical shell containing a part-through surface crack. A Reissner type theory is used to account for the effects of the transverse shear deformations, and the stress intensity factor at the deepest penetration point of the crack is tabulated for bending and membrane loading by varying three-dimensionless length parameters of the problem formed from the shell radius, the shell thickness, the crack length, and the crack depth. The upper bounds of the stress intensity factors are provided, and qualitatively the line-spring model gives the expected results in comparison with elasticity solutions.

Deformation and stress response of composite laminated shells under internal pressure

NASA Technical Reports Server (NTRS)

Yuan, F. G.

1991-01-01

This paper presents a theoretical study of the response of filament wound composite shells under internal pressure. Each layer of the material is generally cylindrically anisotropic. By using cylindrically anisotropic elasticity field equations and Lekhnitskii's stress functions, a system of sixth-order ordinary differential equations is obtained. The general expressions for the stresses and displacements in the laminated composite shells under internal pressure are discussed. Two composite systems, graphite/epoxy and glass/epoxy, are selected to demonstrate the influence of degree of material anisotropy and fiber orientations on the axial and induced twisting deformation. Stress distributions of (45/-45)s symmetric angle-ply fiber-reinforced laminated shells are shown to illustrate the effect of radius-to-thickness ratio.

Contra-rotating homopolar motor-generator for energy storage and return

DOEpatents

Kustom, Robert L.; Wehrle, Robert B.

1978-01-01

An apparatus for receiving electrical energy in amounts of the order of hundreds of megajoules, converting the electrical energy to mechanical energy for storage, and delivering the stored energy as electrical energy in times of the order of a second comprises a sequence of stacked electrically conducting cylindrical shells having a common axis. The conducting shells are free to rotate and are separated by stationary insulating cylindrical shells. Adjacent conducting shells are connected electrically by brushes at the edges and a radial magnetic field is caused to pass through the conductors. The apparatus permits the reversal in a plasma heating coil of electric currents of amplitudes up to 100,000 amperes in a time of the order of a second.

Health care-seeking patterns for female genital mutilation/cutting among young Somalis in Norway.

PubMed

Mbanya, Vivian N; Gele, Abdi A; Diaz, Esperanza; Kumar, Bernadette

2018-04-18

Female genital mutilation/cutting (FGM/C) is a great concern, considering all the potential health implications. Use of health care services related to FGM/C by women who have been subjected to FGM/C in Norway remains to be understood. This study aims to explore the health care-seeking patterns for FGM/C-related health care problems, among young Somalis in Norway. A cross-sectional study involving 325 young Somalis in Oslo was conducted in 2014 using respondent-driven sampling (RDS) technique. The RDS was initiated by a small number of recruited seeds, who were given coded coupons to recruit their peers to participate in the study. Eligible recruiters who participated in the study and redeemed their coupons created the first wave of respondents. The first wave further recruited their peers, the second wave. The cycle continued to attain the needed samples. Using interviews and structured questionnaires, data on socio-demographic, FGM/C status and FGM/C-related use of health care were obtained. Logistic regressions were used to compute the odds ratio (OR) and the confidence interval (CI) for the associations between demographic variables, to circumcision status and health care-seeking for FGM/C. This study will focus on the 159 female participants of the total 325. While 51.6% of the 159 women were subjected to FGM/C, only 20.3% of them used health care services for FGM/C-related problems. Women's FGM/C status was associated with age ≥ 12 years at migration, experience of stigma regarding FGM/C practice (p <  0.05), support of FGM/C practice, and place of birth of women (p <  0.05). Only one-fifth of the women with FGM/C sought care for FGM/C-related health problems. Our study does not provide the answers to why only a few of them sought care for FGM/C. However, as a large proportion of women did not seek care, it is important to investigate the reasons for this. For, we propose to conduct further research targeting girls and women who have undergone FGM/C to assess challenges in accessing health care services for proper intervention.

A semi-analytical solution for elastic analysis of rotating thick cylindrical shells with variable thickness using disk form multilayers.

PubMed

Zamani Nejad, Mohammad; Jabbari, Mehdi; Ghannad, Mehdi

2014-01-01

Using disk form multilayers, a semi-analytical solution has been derived for determination of displacements and stresses in a rotating cylindrical shell with variable thickness under uniform pressure. The thick cylinder is divided into disk form layers form with their thickness corresponding to the thickness of the cylinder. Due to the existence of shear stress in the thick cylindrical shell with variable thickness, the equations governing disk layers are obtained based on first-order shear deformation theory (FSDT). These equations are in the form of a set of general differential equations. Given that the cylinder is divided into n disks, n sets of differential equations are obtained. The solution of this set of equations, applying the boundary conditions and continuity conditions between the layers, yields displacements and stresses. A numerical solution using finite element method (FEM) is also presented and good agreement was found.

A Semi-Analytical Solution for Elastic Analysis of Rotating Thick Cylindrical Shells with Variable Thickness Using Disk Form Multilayers

PubMed Central

Zamani Nejad, Mohammad; Jabbari, Mehdi; Ghannad, Mehdi

2014-01-01

Using disk form multilayers, a semi-analytical solution has been derived for determination of displacements and stresses in a rotating cylindrical shell with variable thickness under uniform pressure. The thick cylinder is divided into disk form layers form with their thickness corresponding to the thickness of the cylinder. Due to the existence of shear stress in the thick cylindrical shell with variable thickness, the equations governing disk layers are obtained based on first-order shear deformation theory (FSDT). These equations are in the form of a set of general differential equations. Given that the cylinder is divided into n disks, n sets of differential equations are obtained. The solution of this set of equations, applying the boundary conditions and continuity conditions between the layers, yields displacements and stresses. A numerical solution using finite element method (FEM) is also presented and good agreement was found. PMID:24719582

Female genital mutilation: Australian law, policy and practical challenges for doctors.

PubMed

Mathews, Ben

2011-02-07

The issue of whether medical practitioners should perform "ritual nicks" as a method of meeting demand for female genital mutilation (FGM) has recently been debated in the United States and Australia. Due to increasing numbers of people arriving and settling in Australia from African nations in which FGM is customary, demand for FGM in Australia is present and may be increasing. Australian law clearly prohibits performance of any type of FGM. FGM is also prohibited by the most recent policy of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG). For legal, medical and social reasons, the RANZCOG policy is sound, and medical practitioners should not administer FGM in any form. Development of an evidence base regarding incidence of and attitudes towards FGM, and the need for post-FGM treatment, would help inform sound policy and practical responses. Strategies adopted in African nations to abolish FGM may assist in refining educational and supportive efforts.

Evidence-based policy responses to strengthen health, community and legislative systems that care for women in Australia with female genital mutilation / cutting.

PubMed

Varol, Nesrin; Hall, John J; Black, Kirsten; Turkmani, Sabera; Dawson, Angela

2017-05-18

The physical and psychological impact of female genital mutilation / cutting (FGM/C) can be substantial, long term, and irreversible. Parts of the health sector in Australia have developed guidelines in the management of FGM/C, but large gaps exist in community and professional knowledge of the consequences and treatment of FGM/C. The prevalence of FGM/C amongst Australian women is unknown. Our article reviews the literature on research on FGM/C in Australia, which focuses on health system response to women and girls with FGM/C. Recommendations are made for policy reform in health, legislation, and community programs to provide the best healthcare, protect children, and help communities abandon this harmful practice. Midwives and doctors in Australia acknowledged a lack of knowledge on FGM/C, clinical guidelines and consequences for maternity care. In a metropolitan Australian hospital with specialised FGM/C care, women with FGM/C had similar obstetric outcomes as women without FGM/C, underlining the importance of holistic FGM/C clinics. Greater focus on integration of refugee and migrant populations into their new cultures may be an important way of facilitating the abandonment of this practice, as is education of communities that practise FGM/C, and experts involved in the care and protection of children. Men could be important advocates for protecting women and girls from violence and FGM/C through a man-to-man strategy with programs focussing on men's health and other personal issues, education, and communication. The Australian Government has identified gender-based violence as an area of priority and has been implementing a National plan to reduce violence against women and their children 2010-2022. A multidisciplinary network of experts on FGM/C could be established within this taskforce to develop well-defined and rapid referral pathways to care for and protect these children, as well as coordinate education and prevention programs to help communities abandon this harmful practice. Countries of migration can be part of the solution for abandonment of FGM/C through community interventions and implementation of national and coordinated training in FGM/C of experts involved in the care and protection of children and women. The global focus on collaboration on research, training and prevention programs should be fostered between countries of FGM/C prevalence and migration.

Knowledge, attitude, and experience of health professionals of female genital mutilation (FGM): A qualitative study in Iraqi Kurdistan Region.

PubMed

Shabila, Nazar P; Ahmed, Hamdia M; Safari, Kolsoom

2017-11-01

We aimed to assess the knowledge, attitude, and experience of health professionals of female genital mutilation (FGM). The study involved content analysis of semistructured interviews with 21 health professionals. The participants had poor knowledge regarding different aspects of FGM including its types, prevalence, and complications as well as the existing legislation that prohibits FGM. They believed that FGM is mainly practiced for religious reasons and to reduce sexual desire/arousal. Health professionals are apparently not involved in performing FGM, and they do not support its continuation. Health professionals can take a leading role in raising the awareness of women and combating FGM.

Experimental investigation of the influence of internal frames on the vibroacoustic behavior of a stiffened cylindrical shell using wavenumber analysis

NASA Astrophysics Data System (ADS)

Meyer, V.; Maxit, L.; Renou, Y.; Audoly, C.

2017-09-01

The understanding of the influence of non-axisymmetric internal frames on the vibroacoustic behavior of a stiffened cylindrical shell is of high interest for the naval or aeronautic industries. Several numerical studies have shown that the non-axisymmetric internal frame can increase the radiation efficiency significantly in the case of a mechanical point force. However, less attention has been paid to the experimental verification of this statement. That is why this paper proposes to compare the radiation efficiency estimated experimentally for a stiffened cylindrical shell with and without internal frames. The experimental process is based on scanning laser vibrometer measurements of the vibrations on the surface of the shell. A transform of the vibratory field in the wavenumber domain is then performed. It allows estimating the far-field radiated pressure with the stationary phase theorem. An increase of the radiation efficiency is observed in the low frequencies. Analysis of the velocity field in the physical and wavenumber spaces allows highlighting the coupling of the circumferential orders at the origin of the increase in the radiation efficiency.

Missed opportunities for diagnosis of female genital mutilation.

PubMed

Abdulcadir, Jasmine; Dugerdil, Adeline; Boulvain, Michel; Yaron, Michal; Margairaz, Christiane; Irion, Olivier; Petignat, Patrick

2014-06-01

To investigate missed opportunities for diagnosing female genital mutilation (FGM) at an obstetrics and gynecology (OB/GYN) department in Switzerland. In a retrospective study, we included 129 consecutive women with FGM who attended the FGM outpatient clinic at the Department of Gynecology and Obstetrics at the University Hospitals of Geneva between 2010 and 2012. The medical files of all women who had undergone at least 1 previous gynecologic exam performed by an OB/GYN doctor or a midwife at the study institution were reviewed. The type of FGM reported in the files was considered correct if it corresponded to that reported by the specialized gynecologist at the FGM clinic, according to WHO classification. In 48 (37.2%) cases, FGM was not mentioned in the medical file. In 34 (26.4%) women, the diagnosis was correct. FGM was identified but erroneously classified in 28 (21.7%) cases. There were no factors (women's characteristics or FGM type) associated with missed diagnosis. Opportunities to identify FGM are frequently missed. Measures should be taken to improve FGM diagnosis and care. Copyright © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Comparisons of Backscattering from Cylindrical Shells Described by Thin Shell and Elasticity Theories.

DTIC Science & Technology

1991-03-04

term that describes inextensional motion. The first equation represents the normal stress at the midsurface of the shell, which is equal to the...that the normal velocity at the midsurface of the shell is proportional to the normal derivative of the total pressw e. The scattered pressure ps can

Developments in Cylindrical Shell Stability Analysis

NASA Technical Reports Server (NTRS)

Knight, Norman F., Jr.; Starnes, James H., Jr.

1998-01-01

Today high-performance computing systems and new analytical and numerical techniques enable engineers to explore the use of advanced materials for shell design. This paper reviews some of the historical developments of shell buckling analysis and design. The paper concludes by identifying key research directions for reliable and robust methods development in shell stability analysis and design.

Sound Transmission through Cylindrical Shell Structures Excited by Boundary Layer Pressure Fluctuations

NASA Technical Reports Server (NTRS)

Tang, Yvette Y.; Silcox, Richard J.; Robinson, Jay H.

1996-01-01

This paper examines sound transmission into two concentric cylindrical sandwich shells subject to turbulent flow on the exterior surface of the outer shell. The interior of the shells is filled with fluid medium and there is an airgap between the shells in the annular space. The description of the pressure field is based on the cross-spectral density formulation of Corcos, Maestrello, and Efimtsov models of the turbulent boundary layer. The classical thin shell theory and the first-order shear deformation theory are applied for the inner and outer shells, respectively. Modal expansion and the Galerkin approach are used to obtain closed-form solutions for the shell displacements and the radiation and transmission pressures in the cavities including both the annular space and the interior. The average spectral density of the structural responses and the transmitted interior pressures are expressed explicitly in terms of the summation of the cross-spectral density of generalized force induced by the boundary layer turbulence. The effects of acoustic and hydrodynamic coincidences on the spectral density are observed. Numerical examples are presented to illustrate the method for both subsonic and supersonic flows.

Nonlinear Response of Thin Cylindrical Shells with Longitudinal Cracks and Subjected to Internal Pressure and Axial compression Loads

NASA Technical Reports Server (NTRS)

Starnes, James H.; Rose, Cheryl A.

1998-01-01

The results of an analytical study of the nonlinear response of a thin unstiffened aluminum cylindrical shell with a longitudinal crack are presented. The shell is analyzed with a nonlinear shell analysis code that maintains the shell in a nonlinear equilibrium state while the crack is grown. The analysis accurately accounts for global and local structural response phenomena. Results are presented for internal pressure, axial compression, and combined internal pressure and axial compression loads. The effects of varying crack length on the nonlinear response of the shell subjected to internal pressure are described. The effects of varying crack length on the prebuckling, buckling and postbuckling responses of the shell subjected to axial compression, and subjected to combined internal pressure and axial compression are also described. The results indicate that the nonlinear interaction between the in-plane stress resultants and the out-of-plane displacements near a crack can significantly affect the structural response of the shell. The results also indicate that crack growth instabilities and shell buckling instabilities can both affect the response of the shell as the crack length is increased.

Buckling Behavior of Compression-Loaded Composite Cylindrical Shells With Reinforced Cutouts

NASA Technical Reports Server (NTRS)

Hilburger, Mark W.; Sarnes, James H., Jr.

2004-01-01

Results from a numerical study of the response of thin-walled compression-loaded quasi-isotropic laminated composite cylindrical shells with unreinforced and reinforced square cutouts are presented. The effects of cutout reinforcement orthotropy, size, and thickness on the nonlinear response of the shells are described. A nonlinear analysis procedure has been used to predict the nonlinear response of the shells. The results indicate that a local buckling response occurs in the shell near the cutout when subjected to load and is caused by a nonlinear coupling between local shell-wall deformations and in-plane destabilizing compression stresses near the cutout. In general, reinforcement around a cutout in a compression-loaded shell is shown to retard or eliminate the local buckling response near the cutout and increase the buckling load of the shell. However, some results show that certain reinforcement configurations can cause an unexpected increase in the magnitude of local deformations and stresses in the shell and cause a reduction in the buckling load. Specific cases are presented that suggest that the orthotropy, thickness, and size of a cutout reinforcement in a shell can be tailored to achieve improved buckling response characteristics.

Socioeconomic and Reproductive Health Outcomes of Female Genital Mutilation.

PubMed

Refaei, Mansoureh; Aghababaei, Soodabeh; Pourreza, Abolghasem; Masoumi, Seyedeh Zahra

2016-11-01

Female genital mutilation (FGM) is one of the important aspects of reproductive health. The economic, social and health consequences of FGM threaten the achievement of sustainable development goals. The purpose of this study was to assess the economic, social and reproductive health consequences of FGM from the perspective of individual, family, community and health system. In this study, we reviewed 1536 articles from 1979 to 2015. Fifty-one studies were directly related to our goal. Research papers, review articles, case studies and books on the research topic were used. The results of this review showed that most studies on FGM, have investigated health complications of FGM, and few studies have addressed its socioeconomic aspects. The complications from the FGM can impose a significant economic burden on individuals, society and health system. Social consequences of FGM are more irritating than health consequences, so to tackle this practice; its social aspects should be more emphasized. Significant short and long term consequences of FGM threaten women's reproductive health; Reproductive health is one of the essential prerequisites of sustainable development. Sustainable development will be achieved if women are healthy. This practice can threaten achieving sustainable development. In Iran, FGM is performed in some areas, but there are no official statistics about it and there has yet been no plan to deal with FGM. FGM is a form of social injustice which women suffer. Ending FGM requires a deep and long-term commitment. Knowing its consequences and its effects on individual, families, the health system and community will help supporters to continue fighting this practice. Any money spent on eliminating this harmful practice, compared with the costs of complications, would not be wasteful.  It seems that further studies are needed to assess socioeconomic effects of FGM and the relationship between type of FGM and induced complications. Such studies will help policymakers to tackle this practice.

Female genital mutilation among mothers and daughters in Harar, eastern Ethiopia.

PubMed

Oljira, Teshome; Assefa, Nega; Dessie, Yadeta

2016-12-01

To assess the practice of female genital mutilation (FGM) among mothers and daughters, and to investigate sociodemographic factors influencing the practice of FGM in Harar, Ethiopia. A community-based cross-sectional study was conducted among women aged 15 years or older who had at least one living daughter younger than 12 years via the Harar Health and Demographic Surveillance System 2013. Data were collected through face-to-face interviews. The practice of FGM was compared between mothers and their daughters. Whether the daughter had undergone FGM was included as an outcome variable in bivariate and multivariate analyses. Among 842 mothers, 669 (79.5%) reported that they had undergone FGM themselves, and 160 (19.0%) that their daughter had undergone FGM. Traditional practitioners were said to be the major performers of FGM by 151 (94.4%) mothers. Mothers whose daughter was mutilated mentioned social acceptance (144 [90.0%] women) and better marriage prospects (96 [60.0%]) as the major benefits. Genital mutilation of daughters was significantly associated with maternal age, education to grade 1-4, and FGM experience. Amhara ethnic origin was significantly associated with a reduced likelihood of FGM among daughters. Over one generation, the incidence of FGM has reduced. Increasing advocacy against FGM and enforcement of law should be emphasized. Copyright © 2016 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Sound Transmission through Two Concentric Cylindrical Sandwich Shells

NASA Technical Reports Server (NTRS)

Tang, Yvette Y.; Silcox, Richard J.; Robinson, Jay H.

1996-01-01

This paper solves the problem of sound transmission through a system of two infinite concentric cylindrical sandwich shells. The shells are surrounded by external and internal fluid media and there is fluid (air) in the annular space between them. An oblique plane sound wave is incident upon the surface of the outer shell. A uniform flow is moving with a constant velocity in the external fluid medium. Classical thin shell theory is applied to the inner shell and first-order shear deformation theory is applied to the outer shell. A closed form for transmission loss is derived based on modal analysis. Investigations have been made for the impedance of both shells and the transmission loss through the shells from the exterior into the interior. Results are compared for double sandwich shells and single sandwich shells. This study shows that: (1) the impedance of the inner shell is much smaller than that of the outer shell so that the transmission loss is almost the same in both the annular space and the interior cavity of the shells; (2) the two concentric sandwich shells can produce an appreciable increase of transmission loss over single sandwich shells especially in the high frequency range; and (3) design guidelines may be derived with respect to the noise reduction requirement and the pressure in the annular space at a mid-frequency range.

Radially Symmetric Motions of Nonlinearly Viscoelastic Bodies Under Live Loads

NASA Astrophysics Data System (ADS)

Stepanov, Alexey B.; Antman, Stuart S.

2017-12-01

This paper treats radially symmetric motions of nonlinearly viscoelastic circular-cylindrical and spherical shells subjected to the live loads of centrifugal force and (time-dependent) hydrostatic pressures. The governing equations are exact versions of those for 3-dimensional continuum mechanics (so shell does not connote an approximate via some shell theory). These motions are governed by quasilinear third-order parabolic-hyperbolic equations having but one independent spatial variable. The principal part of such a partial differential equation is determined by a general family of nonlinear constitutive equations. The presence of strains in two orthogonal directions requires a careful treatment of constitutive restrictions that are physically natural and support the analysis. The interaction of geometrically exact formulations, the compatible use of general constitutive equations for material response, and the presence of live loads show how these factors play crucial roles in the behavior of solutions. In particular, for different kinds of live loads there are thresholds separating materials that produce qualitatively different dynamical behavior. The analysis (using classical methods) covers infinite-time blowup for cylindrical shells subject to centrifugal forces, infinite-time blowup for cylindrical shells subject to steady and time-dependent hydrostatic pressures, finite-time blowup for spherical shells subject to steady and time-dependent hydrostatic pressures, and the preclusion of total compression. This paper concludes with a sketch (using some modern methods) of the existence of regular solutions until the time of blowup.

Female Genital Mutilation/Cutting: Innovative Training Approach for Nurse-Midwives in High Prevalent Settings.

PubMed

Kimani, Samuel; Esho, Tammary; Kimani, Violet; Muniu, Samuel; Kamau, Jane; Kigondu, Christine; Karanja, Joseph; Guyo, Jaldesa

2018-01-01

Female genital mutilation/cutting (FGM/C) has no medical benefits and is associated with serious health complications. FGM/C including medicalization is illegal in Kenya. Capacity building for nurse-midwives to manage and prevent FGM/C is therefore critical. Determine the current FGM/C knowledge and effect of training among nurse-midwives using an electronic tool derived from a paper-based quiz on FGM/C among nurse-midwives. Nurse-midwives ( n =26) were assessed pre- and post-FGM/C training using a quiz comprising 12 questions. The quiz assessed the following factors: definition, classification, determining factors, epidemiology, medicalization, prevention, health consequences, and nurse-midwives' roles in FGM/C prevention themes. The scores for individuals and all the questions were computed and compared using SPSS V22. The mean scores for the quiz were 64.8%, improving to 96.2% p < 0.05 after training. Before the training, the following proportions of participants correctly answered questions demonstrating their knowledge of types of cutting (84.6%), link with health problems (96.2%), FGM/C-related complications (96.2%), communities that practice FGM/C (61.5%), medicalization (43.6%), reinfibulation (46.2%), dissociation from religion (46.2%), and the law as it relates to FGM/C (46.2%). The participants demonstrated knowledge of FGM/C-related complications with the proportion of nurse-midwives correctly answering questions relating to physical impact (69.2%), psychological impact (69.2%), sexual impact (57.7%), and social impact (38.5%). Additionally, participant awareness of NM roles in managing FGM/C included the following: knowledge of the nurse-midwife as counselor (69.2%), advocate (80.8%), leader (26.9%), role model (42.3%), and caregiver (34.6%). These scores improved significantly after training. Substantial FGM/C-related knowledge was demonstrated by nurse-midwives. They, however, showed challenges in preventing/rejecting medicalization of FGM/C, and there were knowledge gaps concerning sexual and social complications, as well as the specific roles of NM. This underscores the need to implement innovative FGM/C training interventions to empower health professionals to better respond to its management and prevention.

Female Genital Mutilation/Cutting: Innovative Training Approach for Nurse-Midwives in High Prevalent Settings

PubMed Central

Esho, Tammary; Kimani, Violet; Kamau, Jane; Kigondu, Christine; Karanja, Joseph; Guyo, Jaldesa

2018-01-01

Background Female genital mutilation/cutting (FGM/C) has no medical benefits and is associated with serious health complications. FGM/C including medicalization is illegal in Kenya. Capacity building for nurse-midwives to manage and prevent FGM/C is therefore critical. Objective Determine the current FGM/C knowledge and effect of training among nurse-midwives using an electronic tool derived from a paper-based quiz on FGM/C among nurse-midwives. Methods Nurse-midwives (n=26) were assessed pre- and post-FGM/C training using a quiz comprising 12 questions. The quiz assessed the following factors: definition, classification, determining factors, epidemiology, medicalization, prevention, health consequences, and nurse-midwives' roles in FGM/C prevention themes. The scores for individuals and all the questions were computed and compared using SPSS V22. Results The mean scores for the quiz were 64.8%, improving to 96.2% p < 0.05 after training. Before the training, the following proportions of participants correctly answered questions demonstrating their knowledge of types of cutting (84.6%), link with health problems (96.2%), FGM/C-related complications (96.2%), communities that practice FGM/C (61.5%), medicalization (43.6%), reinfibulation (46.2%), dissociation from religion (46.2%), and the law as it relates to FGM/C (46.2%). The participants demonstrated knowledge of FGM/C-related complications with the proportion of nurse-midwives correctly answering questions relating to physical impact (69.2%), psychological impact (69.2%), sexual impact (57.7%), and social impact (38.5%). Additionally, participant awareness of NM roles in managing FGM/C included the following: knowledge of the nurse-midwife as counselor (69.2%), advocate (80.8%), leader (26.9%), role model (42.3%), and caregiver (34.6%). These scores improved significantly after training. Conclusion Substantial FGM/C-related knowledge was demonstrated by nurse-midwives. They, however, showed challenges in preventing/rejecting medicalization of FGM/C, and there were knowledge gaps concerning sexual and social complications, as well as the specific roles of NM. This underscores the need to implement innovative FGM/C training interventions to empower health professionals to better respond to its management and prevention. PMID:29736171

Development of X-Ray Laser Media: Measurement of Gain and Development of Cavity Resonators for Wavelengths Near 130 Angstroms.

DTIC Science & Technology

1985-09-30

El recombination inversion, is much more effective. Furthermore, we have studied extensively a more advanced geometry which we predict theoretically ...to be even more effective: that of laser-imploded thin cylindrical shells. We report here on theoretical and Codes or. - .. I-. - experimental progress... theoretical analysis, as well as the actual demonstration on OMEGA of the compression of cylindrical shell targets were described in a paper entitled

Immunomodulating and anti-allergic effects of Negroamaro and Koshu Vitis vinifera fermented grape marc (FGM).

PubMed

Marzulli, Giuseppe; Magrone, Thea; Vonghia, Luisa; Kaneko, Masahiro; Takimoto, Hiroaki; Kumazawa, Yoshio; Jirillo, Emilio

2014-01-01

Polyphenols contained in FGM from Negroamaro (N) and Koshu (K) Vitis vinifera have been shown to exhibit several immunomodulating activities. For instance, mice affected by experimental colitis when administered with K-FGM showed an attenuation of the inflammatory process. In murine asthma, K-FGM reduced IgE production and eosinophil number in bronchial alveolar lavage fluid. In vitro, both N- and K-FGM were able to induce T regulatory cells in terms of Foxp-3 molecule expression and release of interleukin-10. In another set of experiments both N- and K-FGM were able to balance rate of proliferation/apoptosis/necrosis of normal human peripheral lymphocytes, thus indicating the property of these compounds to maintain immune homeostatic mechanisms in the host. On the other hand, N- and K-FGM inhibited human basophil degranulation, thus, confirming our previous results obtained with rat basophilic leukemia cells. Finally, N- and K-FGM also decreased oxidative burst of human polymorphonuclear cells and monocytes.Taken together, these findings imply the potential clinical usefulness of FGM administration in inflammatory/allergic conditions, such as chronic asthma.

Passively Damped Laminated Piezoelectric Shell Structures with Integrated Electric Networks

NASA Technical Reports Server (NTRS)

Saravanos, Dimitris A.

1999-01-01

Multi-field mechanics are presented for curvilinear piezoelectric laminates interfaced with distributed passive electric components. The equations of motion for laminated piezoelectric shell structures with embedded passive electric networks are directly formulated and solved using a finite element methodology. The modal damping and frequencies of the piezoelectric shell are calculated from the poles of the system. Experimental and numerical results are presented for the modal damping and frequency of composite beams with a resistively shunted piezoceramic patch. The modal damping and frequency of plates, cylindrical shells and cylindrical composite blades with piezoelectric-resistor layers are predicted. Both analytical and experimental studies illustrate a unique dependence of modal damping and frequencies on the shunting resistance and show the effect of structural shape and curvature on piezoelectric damping.

Cryogenic line insulation made from prefabricated polyurethane shells

NASA Technical Reports Server (NTRS)

Lerma, G.

1975-01-01

Prefabricated polyurethane foam insulation is inexpensive and easily installed on cryogenic lines. Insulation sections are semicircular half shells. Pair of half shells is placed to surround cryogenic line. Cylindrically-shaped knit sock is pulled over insulation then covered with polyurethane resin to seal system.

A cylindrical shell with an arbitrarily oriented crack

NASA Technical Reports Server (NTRS)

Yahsi, O. S.; Erdogan, F.

1983-01-01

The general problem of a shallow shell with constant curvatures is considered. It is assumed that the shell contains an arbitrarily oriented through crack and the material is specially orthotropic. The nonsymmetric problem is solved for arbitrary self equilibrating crack surface tractions, which, added to an appropriate solution for an uncracked shell, would give the result for a cracked shell under most general loading conditions. The problem is reduced to a system to five singular integral equations in a set of unknown functions representing relative displacements and rotations on the crack surfaces. The stress state around the crack tip is asymptotically analyzed and it is shown that the results are identical to those obtained from the two dimensional in plane and antiplane elasticity solutions. The numerical results are given for a cylindrical shell containing an arbitrarily oriented through crack. Some sample results showing the effect of the Poisson's ratio and the material orthotropy are also presented. Previously annunced in STAR as N83-16783

Sound transmission through double cylindrical shells lined with porous material under turbulent boundary layer excitation

NASA Astrophysics Data System (ADS)

Zhou, Jie; Bhaskar, Atul; Zhang, Xin

2015-11-01

This paper investigates sound transmission through double-walled cylindrical shell lined with poroelastic material in the core, excited by pressure fluctuations due to the exterior turbulent boundary layer (TBL). Biot's model is used to describe the sound wave propagating in the porous material. Three types of constructions, bonded-bonded, bonded-unbonded and unbonded-unbonded, are considered in this study. The power spectral density (PSD) of the inner shell kinetic energy is predicted for two turbulent boundary layer models, different air gap depths and three types of polyimide foams, respectively. The peaks of the inner shell kinetic energy due to shell resonance, hydrodynamic coincidence and acoustic coincidence are discussed. The results show that if the frequency band over the ring frequency is of interest, an air gap, even if very thin, should exist between the two elastic shells for better sound insulation. And if small density foam has a high flow resistance, a superior sound insulation can still be maintained.

Female genital mutilation: knowledge, attitude and practices of Flemish midwives.

PubMed

Cappon, Sien; L'Ecluse, Charlotte; Clays, Els; Tency, Inge; Leye, Els

2015-03-01

health professionals in Belgium are confronted with female genital mutilation (FGM). To date, no survey to assess knowledge, attitudes and practices on FGM was conducted among midwives in the Northern region of Belgium. the objective of this study was to assess the knowledge, attitude and practices of Flemish midwives regarding female genital mutilation (FGM). we used a quantitative design, using KAP study (semi-structured questionnaire). labour wards, maternity wards and maternal intensive care units (MIC) in 56 hospitals in Flemish region of Belgium. 820 midwives, actively working in labour wards, maternity wards and maternal intensive care units (MIC). 820 valid questionnaires (40.9%) were returned. More than 15% of the respondents were recently confronted with FGM. They were mostly faced with the psychological and sexual complications caused by FGM. Few respondents were aware of existing guidelines regarding FGM in their hospitals (3.5%). The results also showed that only 20.2% was aware of the exact content of the law. The majority of midwives condemned the harmful traditional practice: FGM was experienced as a form of violence against women or a violation of human rights. Only 25.9% declared that FGM forms a part of their midwifery program. The vast majority of respondents (92.5%) indicated a need for more information on the subject. this study indicated that midwives in Flanders are confronted with FGM and its complications and highlighted the gaps in the knowledge of Flemish midwives regarding FGM. This may interfere with the provision of adequate care and prevention of FGM for the new-born daughter. there is an important need for appropriate training of (student)midwives concerning FGM as well as for the development and dissemination of clear guidelines in Flemish hospitals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of female genital mutilation/cutting; types I and II on sexual function: case-controlled study.

PubMed

Ismail, Sahar A; Abbas, Ahmad M; Habib, Dina; Morsy, Hanan; Saleh, Medhat A; Bahloul, Mustafa

2017-08-30

The existing literature is contradictory regarding effects of female genital mutilation/cutting (FGM/C) on sexual functions. The aim of this study was to explore the impact of type I and II FGM/C on sexual function of Egyptian women. We recruited 197 cut women and 197 control women from those visiting Assiut University hospitals for different reasons. We asked each woman to fill the Arabic female sexual function index (FSFI) (a self reported 19-item questionnaire assessing the main domains of female sexual function). Genital Examination was done to confirm the type of FGM. Female sexual dysfunction (FSD) was found in 83.8% of FGM/C cases in contrast to 64.5% of the control. The total FSFI score in the FGM/C group (19.82 ± 7.1) was significantly lower than in the control group (23.34 ± 8.1). Concerning the types of FGM/C, type 73.6% of cases had type I and 26.4% had type II. Type I FGM/C was performed mainly by physicians (62.1%) while type II was performed mainly by midwives (44.4%). FSD was found in 83.4% of FGM/C I cases and in 84.6% of FGM/C II cases. There was no statistically significant difference between the two types of FGM/C as regards total and individual domain scores except for the pain domain. There were significantly lower total and individual domain scores in both FGM/C types except for the desire domain compared to control. In this study, FGM/C was associated with reduced scores of FSFI on all domains scores, and among both types I and II, both were associated with sexual dysfunction.

The history and role of the criminal law in anti-FGM campaigns: Is the criminal law what is needed, at least in countries like Great Britain?

PubMed

Berer, Marge

2015-11-01

The history of campaigns against female genital mutilation (FGM) began in the 1920s. From the beginning, it was recognised that FGM was considered an important rite of passage between childhood and adulthood for girls, based on the importance of controlling female sexuality to maintain chastity and family honour, and to make girls marriageable. How to separate the "cut" from these deeply held norms is a question not yet adequately answered, yet I believe the answer is key to stopping the practice. Since the 1994 ICPD, national and international action against FGM has grown and resolutions have been passed in global forums which define FGM as a form of violence and a violation of children's human rights. These resolutions have contributed to building consensus against FGM and developing national legislation criminalising FGM. Prosecutions or arrests involving FGM have been reported in several African countries and Great Britain, but apart from France, there have been very few. This paper summarises this history and how FGM has been criminalised. It argues that criminalisation may not be the best means of stopping FGM, but can have serious harmful effects itself. It calls for community-led educational information and more support for dialogue within FGM-practising communities, and argues that what is important is addressing the sexual and reproductive health consequences of FGM and gaining the understanding of women who have experienced it and their families as to why they should not make their daughters and grand-daughters go through it too. Copyright © 2015 Elsevier Inc. All rights reserved.

Nonlinear Local Bending Response and Bulging Factors for Longitudinal and Circumferential Cracks in Pressurized Cylindrical Shells

NASA Technical Reports Server (NTRS)

Young, Richard D.; Rose, Cheryl A.; Starnes, James H., Jr.

2000-01-01

Results of a geometrically nonlinear finite element parametric study to determine curvature correction factors or bulging factors that account for increased stresses due to curvature for longitudinal and circumferential cracks in unstiffened pressurized cylindrical shells are presented. Geometric parameters varied in the study include the shell radius, the shell wall thickness, and the crack length. The major results are presented in the form of contour plots of the bulging factor as a function of two nondimensional parameters: the shell curvature parameter, lambda, which is a function of the shell geometry, Poisson's ratio, and the crack length; and a loading parameter, eta, which is a function of the shell geometry, material properties, and the applied internal pressure. These plots identify the ranges of the shell curvature and loading parameters for which the effects of geometric nonlinearity are significant. Simple empirical expressions for the bulging factor are then derived from the numerical results and shown to predict accurately the nonlinear response of shells with longitudinal and circumferential cracks. The numerical results are also compared with analytical solutions based on linear shallow shell theory for thin shells, and with some other semi-empirical solutions from the literature, and limitations on the use of these other expressions are suggested.

MHD Waves in Coronal Loops with a Shell

NASA Astrophysics Data System (ADS)

Mikhalyaev, B. B.; Solov'ev, A. A.

2004-04-01

We consider a model of a coronal loop in the form of a cord surrounded by a coaxial shell. Two slow magnetosonic waves longitudinally propagate within a thin flux tube on the m = 0 cylindrical mode with velocities close to the tube velocities in the cord and the shell. One wave propagates inside the cord, while the other propagates inside the shell. A peculiar feature of the second wave is that the plasma in the cord and the shell oscillates with opposite phases. There are two fast magnetosonic waves on each of the cylindrical modes with m > 0. If the plasma density in the shell is lower than that in the surrounding corona, then one of the waves is radiated into the corona, which causes the loop oscillations to be damped, while the other wave is trapped by the cord, but can also be radiated out under certain conditions. If the plasma density in the shell is higher than that in the cord, then one of the waves is trapped by the shell, while the other wave can also be trapped by the shell under certain conditions. In the wave trapped by the shell and the wave radiated by the tube, the plasma in the cord and the shell oscillates with opposite phases.

Preliminary analysis techniques for ring and stringer stiffened cylindrical shells

NASA Technical Reports Server (NTRS)

Graham, J.

1993-01-01

This report outlines methods of analysis for the buckling of thin-walled circumferentially and longitudinally stiffened cylindrical shells. Methods of analysis for the various failure modes are presented in one cohesive package. Where applicable, more than one method of analysis for a failure mode is presented along with standard practices. The results of this report are primarily intended for use in launch vehicle design in the elastic range. A Microsoft Excel worksheet with accompanying macros has been developed to automate the analysis procedures.

Optical trapping of core-shell magnetic microparticles by cylindrical vector beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Min-Cheng; Gong, Lei; Li, Di

2014-11-03

Optical trapping of core-shell magnetic microparticles is experimentally demonstrated by using cylindrical vector beams. Second, we investigate the optical trapping efficiencies. The results show that radially and azimuthally polarized beams exhibit higher axial trapping efficiencies than the Gaussian beam. Finally, a trapped particle is manipulated to kill a cancer cell. The results make possible utilizing magnetic particles for optical manipulation, which is an important advantage for magnetic particles as labeling agent in targeted medicine and biological analysis.

Chemically Doped Double-Walled Carbon Nanotubes: Cylindrical Molecular Capacitors

NASA Astrophysics Data System (ADS)

Chen, Gugang; Bandow, S.; Margine, E. R.; Nisoli, C.; Kolmogorov, A. N.; Crespi, Vincent H.; Gupta, R.; Sumanasekera, G. U.; Iijima, S.; Eklund, P. C.

2003-06-01

A double-walled carbon nanotube is used to study the radial charge distribution on the positive inner electrode of a cylindrical molecular capacitor. The outer electrode is a shell of bromine anions. Resonant Raman scattering from phonons on each carbon shell reveals the radial charge distribution. A self-consistent tight-binding model confirms the observed molecular Faraday cage effect, i.e., most of the charge resides on the outer wall, even when this wall was originally semiconducting and the inner wall was metallic.

Chemically doped double-walled carbon nanotubes: cylindrical molecular capacitors.

PubMed

Chen, Gugang; Bandow, S; Margine, E R; Nisoli, C; Kolmogorov, A N; Crespi, Vincent H; Gupta, R; Sumanasekera, G U; Iijima, S; Eklund, P C

2003-06-27

A double-walled carbon nanotube is used to study the radial charge distribution on the positive inner electrode of a cylindrical molecular capacitor. The outer electrode is a shell of bromine anions. Resonant Raman scattering from phonons on each carbon shell reveals the radial charge distribution. A self-consistent tight-binding model confirms the observed molecular Faraday cage effect, i.e., most of the charge resides on the outer wall, even when this wall was originally semiconducting and the inner wall was metallic.

Spatial modelling and mapping of female genital mutilation in Kenya.

PubMed

Achia, Thomas N O

2014-03-25

Female genital mutilation/cutting (FGM/C) is still prevalent in several communities in Kenya and other areas in Africa, as well as being practiced by some migrants from African countries living in other parts of the world. This study aimed at detecting clustering of FGM/C in Kenya, and identifying those areas within the country where women still intend to continue the practice. A broader goal of the study was to identify geographical areas where the practice continues unabated and where broad intervention strategies need to be introduced. The prevalence of FGM/C was investigated using the 2008 Kenya Demographic and Health Survey (KDHS) data. The 2008 KDHS used a multistage stratified random sampling plan to select women of reproductive age (15-49 years) and asked questions concerning their FGM/C status and their support for the continuation of FGM/C. A spatial scan statistical analysis was carried out using SaTScan™ to test for statistically significant clustering of the practice of FGM/C in the country. The risk of FGM/C was also modelled and mapped using a hierarchical spatial model under the Integrated Nested Laplace approximation approach using the INLA library in R. The prevalence of FGM/C stood at 28.2% and an estimated 10.3% of the women interviewed indicated that they supported the continuation of FGM. On the basis of the Deviance Information Criterion (DIC), hierarchical spatial models with spatially structured random effects were found to best fit the data for both response variables considered. Age, region, rural-urban classification, education, marital status, religion, socioeconomic status and media exposure were found to be significantly associated with FGM/C. The current FGM/C status of a woman was also a significant predictor of support for the continuation of FGM/C. Spatial scan statistics confirm FGM clusters in the North-Eastern and South-Western regions of Kenya (p<0.001). This suggests that the fight against FGM/C in Kenya is not yet over. There are still deep cultural and religious beliefs to be addressed in a bid to eradicate the practice. Interventions by government and other stakeholders must address these challenges and target the identified clusters.

Experiments on shells under base excitation

NASA Astrophysics Data System (ADS)

Pellicano, Francesco; Barbieri, Marco; Zippo, Antonio; Strozzi, Matteo

2016-05-01

The aim of the present paper is a deep experimental investigation of the nonlinear dynamics of circular cylindrical shells. The specific problem regards the response of circular cylindrical shells subjected to base excitation. The shells are mounted on a shaking table that furnishes a vertical vibration parallel to the cylinder axis; a heavy rigid disk is mounted on the top of the shells. The base vibration induces a rigid body motion, which mainly causes huge inertia forces exerted by the top disk to the shell. In-plane stresses due to the aforementioned inertias give rise to impressively large vibration on the shell. An extremely violent dynamic phenomenon suddenly appears as the excitation frequency varies up and down close to the linear resonant frequency of the first axisymmetric mode. The dynamics are deeply investigated by varying excitation level and frequency. Moreover, in order to generalise the investigation, two different geometries are analysed. The paper furnishes a complete dynamic scenario by means of: (i) amplitude frequency diagrams, (ii) bifurcation diagrams, (iii) time histories and spectra, (iv) phase portraits and Poincaré maps. It is to be stressed that all the results presented here are experimental.

Psychological impact of female genital mutilation among adolescent Egyptian girls: a cross-sectional study.

PubMed

Ahmed, Magdy R; Shaaban, Mohamed M; Meky, Heba K; Amin Arafa, Mohamed E; Mohamed, Tamer Y; Gharib, Waleed F; Ahmed, Abeer B

2017-08-01

Worldwide, at least 200 million women and girls have undergone female genital mutilation (FGM). The medical and sexual consequences have been documented, but the psychological impact has not been studied to the same extent. The aim of this study was to explore the relationship between FGM and psychiatric problems among adolescent girls. A total of 204 girls, aged 14-19 years, were included in a cross-sectional study conducted at Suez Canal University Hospitals. All participants completed an Arabic-validated, structured questionnaire covering nine symptom scales. Sociodemographic data were also collected. Main outcome measures were the prevalence of psychiatric problems among adolescent girls who had undergone FGM. Overall, 66.2% of girls had undergone FGM. The percentage in rural areas was 91.8%, compared with 43.0% in urban areas. There were no significant differences between the FGM and non-FGM groups as regards religion, educational and socioeconomic levels. FGM girls had a significantly higher level of psychological problems with regard to somatisation, depression, anxiety, phobic anxiety and hostility compared with non-FGM girls (p < .0001). FGM is a traumatic experience that may leave a lasting psychological mark and a negative impact on the psychological status of affected girls.

Mapping the lack of public initiative against female genital mutilation in Denmark.

PubMed

Christoffersen, Gro Møller; Bruhn, Peter James; de Neergaard, Rosanna; Engel, Susanne; Naeser, Vibeke

2018-04-07

Female genital mutilation (FGM) is a harmful practice prevalent in 35 countries, mainly in Africa, as well as in some Middle Eastern countries and a few Asian countries. FGM comprises all procedures that involve partial or complete resection of, or other injury to, external female genitalia for non-medical reasons. The practice of FGM has spread to Western countries due to migration. The European Institute for Gender Equality recommend that FGM be combatted by nationally coordinated efforts through implementation of national action plans, guidelines for professionals as well as comprehensive research in the field. FGM was outlawed in Denmark 2003, but no national actions plan has been implemented. Instead, the task of combatting FGM is currently under the responsibility of local governments in the form of the 98 municipalities. The aim of this study is to investigate the Danish municipalities' efforts to prevent FGM on the local level, and whether these initiatives are in accordance with international recommendations and standards. All 98 Danish municipalities were invited to respond to a questionnaire regarding FGM in their respective municipalities. The inclusion process and questionnaire was designed after a pilot study, which included 29 municipalities. The questionnaire consisted of four overall areas of focus: "action plan", "registration", "information material" and "preventive initiatives". Demographic data were gathered from the 2017 census by Statistics Denmark. Risk countries were defined as countries with a tradition for FGM, identified from the 2016 UNICEF definition. A total of 67 municipalities participated in the study. At the time of census, 1.8% of the Danish population was immigrants with origins in risk countries. A total of 10.4% of the responding municipalities indicated to have implemented a specific action plan against FGM. A total of 7,5% had implemented specific preventive initiatives against FGM. Registration of reported FGM cases were indicated to be performed in 73.1% of the responding municipalities; however, only 17.9% stated to perform registration of FGM specifically as such, and not as general child abuse. Our study shows that the current situation of FGM registration and prevention being under local administrative responsibility in the 98 Danish municipalities has led to a severe lack of coordinated public initiative against FGM.

[Excision: the new prohibition that divides the society. Press review: Senegal].

PubMed

1999-12-01

Approximately 700,000 women in Senegal have suffered female genital mutilation (FGM). Now, following a vote upon legislation banning FGM, public opinion in the country over the practice is more divided than ever. The practitioners of FGM are not taking the law seriously, while politicians hesitate to openly condemn the practice, which still occurs widely in rural zones. Most of the 140 parliamentarians do not believe that laws alone can successfully end FGM in Senegal. Some deputies and feminists believe that several years of sensitization on the issue will be needed to effectively reduce the frequency with which FGM is practiced. Only optimists believe FGM will disappear on its own. The debate threatens to resurface in some areas during the year 2000 presidential election. One deputy from the governing party, originally from southern Senegal, states that he dares not tell his constituency that the president himself created the anti-FGM legislation, especially when locally elected leaders finance villages¿ FGM-related celebrations. According to a scholar of the Koran, FGM is an Islamic practice, but it is not taught in the Koran. FGM is therefore a cultural practice borne from individual choice. In Kolda, 650 km south of Dakar, the practitioners of such mutilation argue that they would rather be imprisoned than abandon the practice they consider to be an immutable component of their cultural history.

Are obstetric outcomes affected by female genital mutilation?

PubMed

Balachandran, Aswini A; Duvalla, Swapna; Sultan, Abdul H; Thakar, Ranee

2018-03-01

Female genital mutilation (FGM) has been associated with adverse obstetric and neonatal outcomes, such as postpartum haemorrhage (PPH), perineal trauma, genital fistulae, obstructed labour and stillbirth. The prevalence of FGM has increased in the UK over the last decade. There are currently no studies available that have explored the obstetric impact of FGM in the UK. The aim of our study was to investigate the obstetric and neonatal outcomes of women with FGM when compared with the general population. We conducted a retrospective case-control study of consecutive pregnant women with FGM over a 5-year period between 1 January 2009 and 31 December 2013. Each woman with FGM was matched for age, ethnicity, parity and gestation with subsequent patients without FGM (control cohort) over the same 5-year period. Outcomes assessed were mode of delivery, duration of labour, estimated blood loss, analgaesia, perineal trauma and foetal outcomes. A total of 242 eligible women (121 FGM, 121 control) were identified for the study. There was a significant increase in the use of episiotomy in the FGM group (p = 0.009) and a significant increase in minor PPH in the control group during caesarean sections (p = 0.0001). There were no differences in all other obstetric and neonatal parameters. In our unit, FGM was not associated with an increased incidence of adverse obstetric and foetal morbidity or mortality.

Attitudes and awareness of female genital mutilation: a questionnaire-based study in a Kenyan hospital.

PubMed

Livermore, L; Monteiro, R; Rymer, J

2007-11-01

There are considerable efforts in Kenya to increase awareness of the issues and health risks associated with female genital mutilation (FGM) through educational programmes. The Kenyan government formally outlawed FGM in 2001. This questionnaire-based study aimed to explore attitudes and awareness of FGM in Kenya with particular reference to the law, health complications and educational programmes. A significant decline in the prevalence of FGM was demonstrated and awareness of health complications of FGM shown to be the main factor causing this trend. The need for further efforts to eradicate the practice and the importance of religion and culture in shaping social attitudes was evident. The outlawing of FGM was considered a positive advance but may have the detrimental effect of deterring women from seeking medical assistance for complications relating to FGM.

Multidisciplinary approach to the management of children with female genital mutilation (FGM) or suspected FGM: service description and case series.

PubMed

Creighton, Sarah M; Dear, Joanna; de Campos, Claudia; Williams, Louise; Hodes, Deborah

2016-02-29

To describe the first dedicated clinic in the UK for children with suspected or confirmed female genital mutilation (FGM) including referral patterns, clinical findings and subsequent management. A prospective study of all children seen in a dedicated multidisciplinary FGM clinic for children over a 1-year period. Patients aged under 18 years referred for clinical assessment or for a second opinion on Digital Versatile Disc (DVD) images. Data were collected on reasons for referral, demography, genital examination findings including FGM type, and clinical recommendations. 38 children were referred of whom 18 (47%) had confirmed FGM; most frequently type 4 (61%). Social care and police referred 78% of cases. According to UK law FGM had been performed illegally in three cases. Anonymous information given to the police led to the referral of six children, none of whom had had FGM. Mandatory reporting and increased media attention may increase the numbers of referrals of children with suspected FGM. This patient group have complex needs and management in a dedicated multidisciplinary service is essential. Paediatricians and gynaecologists should have the skills to carry out the consultation and detect all types of FGM including type 4 which was the most common type seen in this series. This is the first dedicated FGM service for children in the UK and similar clinics in high-prevalence areas should be established. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Female genital mutilation and pregnancy: associated risks.

PubMed

Gayle, Claudine; Rymer, Janice

2016-09-22

Female genital mutilation (FGM) is a traditional practice that has no medical benefit and severe health consequences for girls and women. This article discusses the risks to patients who are pregnant and have had FGM. It will describe urinary tract infections caused by FGM, and how this condition increases the risk of preterm labour and delivery. It will also address the difficulty in vaginal examinations that can be caused by FGM and instances when this can delay diagnosis and treatment. In addition, it will explore a number of intrapartum risks caused by FGM and the role of deinfibulation in pregnancy. Finally, it will look at the link between maternal and fetal morbidity and mortality, and FGM.

Geography and correlates of attitude toward Female Genital Mutilation (FGM) in Sudan: What can we learn from successive Sudan opinion poll data?

PubMed

Hamilton, Alexander; Kandala, Ngianga-Bakwin

2016-02-01

In Sudan, prevalence of FGM is declining; likely as a result of changing attitude surrounding FGM, as more women believe the practice should be discontinued amid growing awareness about its health dangers. DFID Sudan opinion poll data collected from 2012 to 2014 was used. Bayesian geo-additive mixed models were used to map the spatial distribution of the likelihood of pro-FGM attitude at the state-level accounting for associated risk factors. During 2012 to 2014, the overall proportion of pro-FGM was 27.5% and 18.3% respectively with striking variations within states. People with pro-FGM attitude were more likely to be un-educated, living in rural settings with strong tribal identity. Individuals from Darfur were more likely to be pro-FGM when compared to the North state. The decrease in the practice of cutting observed between the 2006 and 2010 Sudanese Household Surveys and the resulting shift in attitude make a compelling case for public health policy to eradicate the FGM practice. Copyright © 2015. Published by Elsevier Ltd.

Female genital mutilation and efforts to achieve Millennium Development Goals 3, 4, and 5 in southeast Nigeria.

PubMed

Lawani, Lucky O; Onyebuchi, Azubuike K; Iyoke, Chukwuemeka A; Okeke, Nwabunike E

2014-05-01

To determine the prevalence of female genital mutilation (FGM), the common forms of FGM, reasons for the practice, associated obstetric outcomes, and how these have affected efforts to achieve Millennium Development Goals (MDGs) 3, 4, and 5 in southeast Nigeria. A prospective descriptive study of parturients in southeast Nigeria was conducted from January to December 2012. All primigravid women attending delivery services at 2 health institutions during the study period were recruited, examined, and classified using the 2008 WHO classification for FGM. The mean age of the 516 participants was 27.24±4.80 years and most (66.3%) had undergone FGM. Type II FGM was the most common form, accounting for 59.6% of cases. Most FGM procedures were performed in infancy (97.1%) and for cultural reasons (60.8%). Women who had undergone FGM had significantly higher risk for episiotomy, perineal tear, hemorrhage, cesarean delivery, neonatal resuscitation, fresh stillbirth/early neonatal death, and longer hospitalization, with higher risk ratios associated with higher degrees of FGM. FGM is still a common practice in southeast Nigeria, where its association with adverse reproductive outcomes militates against efforts to achieve MDGs 3, 4, and 5. Copyright © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Female Genital Mutilation in Kenya: are young men allies in social change programmes?

PubMed

Brown, Eleanor; Mwangi-Powell, Faith; Jerotich, Miriam; le May, Victoria

2016-05-01

The Girl Summit held in 2014 aimed to mobilise greater effort to end Female Genital Mutilation (FGM) within a generation, building on a global movement which viewed the practice as a severe form of violence against women and girls and a violation of their rights. The UN, among others, endorse "comprehensive" strategies to end FGM, including legalistic measures, social protection and social communications. FGM is a sensitive issue and difficult to research, and rapid ethnographic methods can use existing relations of trust within social networks to explore attitudes towards predominant social norms which posit FGM as a social necessity. This study used Participatory Ethnographic Evaluation Research (PEER) to understand young men's (18-25 years) perceptions of FGM, demand for FGM among future spouses, and perceptions of efforts to end FGM in a small town in West Pokot, Kenya, where FGM is reported to be high (between 85% to 96%). Twelve PEER researchers were recruited, who conducted two interviews with their friends, generating a total of 72 narrative interviews. The majority of young men who viewed themselves as having a "modern" outlook and with aspirations to marry "educated" women were more likely not to support FGM. Our findings show that young men viewed themselves as valuable allies in ending FGM, but that voicing their opposition to the practice was often difficult. More efforts are needed by multi-stakeholders - campaigners, government and local leaders - to create an enabling environment to voice that opposition. Copyright © 2016 Elsevier Inc. All rights reserved.

Female genital mutilation in children presenting to Australian paediatricians

PubMed Central

Zurynski, Yvonne; Sureshkumar, Premala; Cherian, Sarah; Deverell, Marie; Elliott, Elizabeth J

2017-01-01

Objective The WHO reports that female genital mutilation/cutting (FGM/C) is an ancient cultural practice prevalent in many countries. FGM/C has been reported among women resident in Australia. Our paper provides the first description of FGM/C in Australian children. Design Cross-sectional survey conducted in April–June 2014. Setting Paediatricians and other child health specialists recruited through the Australian Paediatric Surveillance Unit were asked to report children aged <18 years with FGM/C seen in the last 5 years, and to provide data for demographics, FGM/C type, complications and referral for each case. Participants Of 1311 eligible paediatricians/child health specialists, 1003 (76.5%) responded. Results Twenty-three (2.3%) respondents had seen 59 children with FGM/C and provided detailed data for 31. Most (89.7%) were identified during refugee screening and were born in Africa. Three (10.3%) were born in Australia: two had FGM/C in Australia and one in Indonesia. All parents were born overseas, mainly Africa (98.1%). Ten children had WHO FGM/C type I, five type II, five type III and six type IV. Complications in eight children included recurrent genitourinary infections, menstrual, sexual, fertility and psychological problems. Nineteen children (82.6%) were referred to obstetrics/gynaecology: 16 (69.9%) to social work and 13 (56.5%) to child protection. Conclusions This study confirms that FGM/C is seen in paediatric clinical practice within Australia. Paediatricians need cultural awareness, education and resources to help them identify children with FGM/C and/or at risk of FGM/C, to enable appropriate referral and counselling of children, families and communities to assist in the prevention of this practice. PMID:28082321

Female Genital Mutilation/Cutting in the United States: Updated Estimates of Women and Girls at Risk, 2012

PubMed Central

Stupp, Paul; Okoroh, Ekwutosi; Besera, Ghenet; Goodman, David; Danel, Isabella

2016-01-01

Objectives In 1996, the U.S. Congress passed legislation making female genital mutilation/cutting (FGM/C) illegal in the United States. CDC published the first estimates of the number of women and girls at risk for FGM/C in 1997. Since 2012, various constituencies have again raised concerns about the practice in the United States. We updated an earlier estimate of the number of women and girls in the United States who were at risk for FGM/C or its consequences. Methods We estimated the number of women and girls who were at risk for undergoing FGM/C or its consequences in 2012 by applying country-specific prevalence of FGM/C to the estimated number of women and girls living in the United States who were born in that country or who lived with a parent born in that country. Results Approximately 513,000 women and girls in the United States were at risk for FGM/C or its consequences in 2012, which was more than three times higher than the earlier estimate, based on 1990 data. The increase in the number of women and girls younger than 18 years of age at risk for FGM/C was more than four times that of previous estimates. Conclusion The estimated increase was wholly a result of rapid growth in the number of immigrants from FGM/C-practicing countries living in the United States and not from increases in FGM/C prevalence in those countries. Scientifically valid information regarding whether women or their daughters have actually undergone FGM/C and related information that can contribute to efforts to prevent the practice in the United States and provide needed health services to women who have undergone FGM/C are needed. PMID:26957669

Female Genital Mutilation/Cutting in the United States: Updated Estimates of Women and Girls at Risk, 2012.

PubMed

Goldberg, Howard; Stupp, Paul; Okoroh, Ekwutosi; Besera, Ghenet; Goodman, David; Danel, Isabella

2016-01-01

In 1996, the U.S. Congress passed legislation making female genital mutilation/cutting (FGM/C) illegal in the United States. CDC published the first estimates of the number of women and girls at risk for FGM/C in 1997. Since 2012, various constituencies have again raised concerns about the practice in the United States. We updated an earlier estimate of the number of women and girls in the United States who were at risk for FGM/C or its consequences. We estimated the number of women and girls who were at risk for undergoing FGM/C or its consequences in 2012 by applying country-specific prevalence of FGM/C to the estimated number of women and girls living in the United States who were born in that country or who lived with a parent born in that country. Approximately 513,000 women and girls in the United States were at risk for FGM/C or its consequences in 2012, which was more than three times higher than the earlier estimate, based on 1990 data. The increase in the number of women and girls younger than 18 years of age at risk for FGM/C was more than four times that of previous estimates. The estimated increase was wholly a result of rapid growth in the number of immigrants from FGM/C-practicing countries living in the United States and not from increases in FGM/C prevalence in those countries. Scientifically valid information regarding whether women or their daughters have actually undergone FGM/C and related information that can contribute to efforts to prevent the practice in the United States and provide needed health services to women who have undergone FGM/C are needed.

Decline of Supportive Attitudes among Husbands toward Female Genital Mutilation and Its Association to Those Practices in Yemen

PubMed Central

Al-Khulaidi, Ghadah Abdulmajid; Nakamura, Keiko; Seino, Kaoruko; Kizuki, Masashi

2013-01-01

Objectives To elucidate the attitudes of women and their husband’s towards female genital mutilation (FGM) and their associations with the continuation of FGM upon their daughters. Methods Subjects were 10,345 (in 1997) and 11,252 (in 2003) ever married women aged 15 to 49 years from the Yemen Demographic Health Surveys. Performances of FGM on the most-recently-born daughters were investigated. Attitudes of women and their husbands were assessed by their opinions on the continuation of FGM. The association between the attitudes of women and their husbands and performance of FGM on the most-recently-born daughters were investigated after adjusting for age and education of the women. Findings The percentage among the most-recently-born daughters who received FGM of women who had undergone FGM declined from 61.9% in 1997 to 56.5% in 2003 (p<0.001). The percentages of women who had undergone FGM and who supported the continuation of FGM and of husbands who also supported its continuation decreased from 78.2% and 60.1% in 1997 to 70.9% and 49.5% in 2003, respectively (both p<0.001). When the women or the husbands did not agree with FGM, it was less likely to be performed on their daughter than when the women or the husbands agreed in 1997 (odds ratio=0.11, 95% confidence interval 0.07-0.16 and odds ratio=0.07, 95% confidence interval 0.04-0.12, respectively) and in 2003 (odds ratio=0.12, 95% confidence interval 0.09-0.16 and odds ratio=0.11, 95% confidence interval 0.07-0.16, respectively). Conclusion Non-supportive attitudes of women and their husbands towards the continuation of FGM have become common and were associated with their decision not to perform FGM upon their daughters. PMID:24367582

Daughters at Risk of Female Genital Mutilation: Examining the Determinants of Mothers’ Intentions to Allow Their Daughters to Undergo Female Genital Mutilation

PubMed Central

Pashaei, Tahereh; Ponnet, Koen; Moeeni, Maryam; Khazaee-pool, Maryam; Majlessi, Fereshteh

2016-01-01

Female genital mutilation (FGM) is still a common practice in many countries in Africa and the Middle East. Understanding the determinants of FGM can lead to more active interventions to prevent this harmful practice. The goal of this study is to explore factors associated with FGM behavior among Iranian mothers and their daughters. Based on Ajzen’s theory of planned behavior, we examined the predictive value of attitudes, subjective norms, perceived behavioral control and several socio-demographic variables in relation to mothers’ intentions to mutilate their daughters. A paper-and-pencil survey was conducted among 300 mothers (mean age = 33.20, SD = 9.09) who had at least one daughter and who lived in Ravansar, a county in Kermanshah Province in Iran. Structural equation modeling was used to investigate the relationships among the study variables. Our results indicate that attitude is the strongest predictor of mothers’ intentions to allow their daughters to undergo FGM, followed by subjective norms. Compared to younger mothers, older mothers have more positive attitudes toward FGM, perceive themselves as having more control over their behavior and demonstrate a greater intention to allow their daughter to undergo FGM. Furthermore, we found that less educated mothers and mothers living in rural areas had more positive attitudes toward FGM and feel more social pressure to allow FGM. The model accounts for 93 percent of the variance in the mothers’ intentions to allow their daughters to undergo FGM. Intervention programs that want to decrease FGM might focus primarily on converting mothers’ neutral or positive feelings toward FGM into negative attitudes and on alleviating the perceived social pressure to mutilate one’s daughter. Based on our findings, we provide recommendations about how to curtail mothers’ intentions to allow their daughters to undergo FGM. PMID:27031613

Decline of supportive attitudes among husbands toward female genital mutilation and its association to those practices in Yemen.

PubMed

Al-Khulaidi, Ghadah Abdulmajid; Nakamura, Keiko; Seino, Kaoruko; Kizuki, Masashi

2013-01-01

To elucidate the attitudes of women and their husband's towards female genital mutilation (FGM) and their associations with the continuation of FGM upon their daughters. Subjects were 10,345 (in 1997) and 11,252 (in 2003) ever married women aged 15 to 49 years from the Yemen Demographic Health Surveys. Performances of FGM on the most-recently-born daughters were investigated. Attitudes of women and their husbands were assessed by their opinions on the continuation of FGM. The association between the attitudes of women and their husbands and performance of FGM on the most-recently-born daughters were investigated after adjusting for age and education of the women. The percentage among the most-recently-born daughters who received FGM of women who had undergone FGM declined from 61.9% in 1997 to 56.5% in 2003 (p<0.001). The percentages of women who had undergone FGM and who supported the continuation of FGM and of husbands who also supported its continuation decreased from 78.2% and 60.1% in 1997 to 70.9% and 49.5% in 2003, respectively (both p<0.001). When the women or the husbands did not agree with FGM, it was less likely to be performed on their daughter than when the women or the husbands agreed in 1997 (odds ratio=0.11, 95% confidence interval 0.07-0.16 and odds ratio=0.07, 95% confidence interval 0.04-0.12, respectively) and in 2003 (odds ratio=0.12, 95% confidence interval 0.09-0.16 and odds ratio=0.11, 95% confidence interval 0.07-0.16, respectively). Non-supportive attitudes of women and their husbands towards the continuation of FGM have become common and were associated with their decision not to perform FGM upon their daughters.

Female genital mutilation: an injury, physical and mental harm.

PubMed

Utz-Billing, I; Kentenich, H

2008-12-01

This article gives an overview over the huge topic of 'female genital mutilation' (FGM). FGM means non-therapeutic, partial or complete removal or injury of each of the external female genitals. It concerns about 130 million women around the world. FGM is performed in about 30 countries, most of which are located in Africa. Four types of FGM are distinguished: type I stands for the removal of the clitoral foreskin, type II means the removal of the clitoris with partial or total excision of the labia minora. Type III is the extreme type of FGM. Not only the clitoris but also the labia minora and majora were removed. The orificium vaginae is sewn up, leaving only a small opening for urine or menstruation blood. Other types like pricking, piercing of clitoris or vulva, scraping of the vagina, etc. were defined as type IV of FGM. The mentioned reasons for FGM are: encouragement of the patriarchal family system, method for birth control, guarantee of moral behaviour and faithfulness to the husband, protection of women from suspicions and disgrace, initiation ritual, symbol of feminity and beauty, hygienic, health and economic advantages. Acute physical consequences of FGM include bleeding, wound infections, sepsis, shock, micturition problems and fractures. Chronic physical problems like anemia, infections of the urinary tract, incontinence, infertility, pain, menstruation problems and dyspareunia are frequent. Women also have a higher risk for HIV infections. During pregnancy and delivery, examinations and vaginal application of medicine are more difficult. Women have a higher risk for a prolonged delivery, wound infections, a postpartum blood loss of more than 500 mL, perineal tears, a resuscitation of the infant and an inpatient perinatal death. Mental consequences after FGM include the feelings of incompleteness, fear, inferiority and suppression. Women report chronic irritability and nightmares. They have a higher risk for psychiatric and psychosomatic diseases. FGM carried out by doctors, nurses or midwives is also called medicalisation of FGM and is definitely unacceptable. Regarding human rights, FGM refuses women the right of freedom from bodily harm. Specific laws that ban FGM exist in many countries in Europe, Africa, USA, Canada, New Zealand and Australia.

Spatial modelling and mapping of female genital mutilation in Kenya

PubMed Central

2014-01-01

Background Female genital mutilation/cutting (FGM/C) is still prevalent in several communities in Kenya and other areas in Africa, as well as being practiced by some migrants from African countries living in other parts of the world. This study aimed at detecting clustering of FGM/C in Kenya, and identifying those areas within the country where women still intend to continue the practice. A broader goal of the study was to identify geographical areas where the practice continues unabated and where broad intervention strategies need to be introduced. Methods The prevalence of FGM/C was investigated using the 2008 Kenya Demographic and Health Survey (KDHS) data. The 2008 KDHS used a multistage stratified random sampling plan to select women of reproductive age (15–49 years) and asked questions concerning their FGM/C status and their support for the continuation of FGM/C. A spatial scan statistical analysis was carried out using SaTScan™ to test for statistically significant clustering of the practice of FGM/C in the country. The risk of FGM/C was also modelled and mapped using a hierarchical spatial model under the Integrated Nested Laplace approximation approach using the INLA library in R. Results The prevalence of FGM/C stood at 28.2% and an estimated 10.3% of the women interviewed indicated that they supported the continuation of FGM. On the basis of the Deviance Information Criterion (DIC), hierarchical spatial models with spatially structured random effects were found to best fit the data for both response variables considered. Age, region, rural–urban classification, education, marital status, religion, socioeconomic status and media exposure were found to be significantly associated with FGM/C. The current FGM/C status of a woman was also a significant predictor of support for the continuation of FGM/C. Spatial scan statistics confirm FGM clusters in the North-Eastern and South-Western regions of Kenya (p < 0.001). Conclusion This suggests that the fight against FGM/C in Kenya is not yet over. There are still deep cultural and religious beliefs to be addressed in a bid to eradicate the practice. Interventions by government and other stakeholders must address these challenges and target the identified clusters. PMID:24661558

78 FR 60763 - Clarification on Fireworks Policy Regarding Approvals or Certifications for Firework Series

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-02

... Fountain Cylindrical Fountain Illuminating Torch Mine and Shell Missile with Fin-type Rocket Roman Candle Sky Rocket/Bottle Rocket Toy Smoke Device Wire Sparkler/Dipped Sparkler Display Aerial Shell...

A Tradition in Transition: Factors Perpetuating and Hindering the Continuance of Female Genital Mutilation/Cutting (FGM/C) Summarized in a Systematic Review

PubMed Central

Berg, Rigmor C.; Denison, Eva

2013-01-01

Understanding the forces underpinning female genital mutilation/cutting (FGM/C) is a necessary first step to prevent the continuation of a practice that is associated with health complications and human rights violations. To this end, a systematic review of 21 studies was conducted. Based on this review, the authors reveal six key factors that underpin FGM/C: cultural tradition, sexual morals, marriageability, religion, health benefits, and male sexual enjoyment. There were four key factors perceived to hinder FGM/C: health consequences, it is not a religious requirement, it is illegal, and the host society discourse rejects FGM/C. The results show that FGM/C appears to be a tradition in transition. PMID:23489149

Transverse shear effect in a circumferentially cracked cylindrical shell

NASA Technical Reports Server (NTRS)

Delale, F.; Erdogan, F.

1979-01-01

The objectives of the paper are to solve the problem of a circumferentially-cracked cylindrical shell by taking into account the effect of transverse shear, and to obtain the stress intensity factors for the bending moment as well as the membrane force as the external load. The formulation of the problem is given for a specially orthotropic material within the framework of a linearized shallow shell theory. The particular theory used permits the consideration of all five boundary conditions as to moment and stress resultants on the crack surface. The effect of Poisson's ratio on the stress intensity factors and the nature of the out-of-plane displacement along the edges of the crack, i.e., bulging, are also studied.

A survey of Australian midwives' knowledge, experience, and training needs in relation to female genital mutilation.

PubMed

Turkmani, Sabera; Homer, Caroline; Varol, Nesrin; Dawson, Angela

2018-02-01

Female genital mutilation (FGM) involves partial or total removal of the external female genitalia or any other injury for non-medical reasons. Due to international migration patterns, health professionals in high income countries are increasingly caring for women with FGM. Few studies explored the knowledge and skills of midwives in high income countries. To explore the knowledge, experience and needs of midwives in relation to the care of women with FGM. An online self-administered descriptive survey was designed and advertised through the Australian College of Midwives' website. Of the 198 midwives (24%) did not know the correct classification of FGM. Almost half of the respondents (48%) reported they had not received FGM training during their midwifery education. Midwives (8%) had been asked, or knew of others who had been asked to perform FGM in Australia. Many midwives were not clear about the law or health data related to FGM and were not aware of referral paths for affected women. As frontline providers, midwives must have appropriate up-to-date clinical skills and knowledge to ensure they are able to provide women with FGM the care they need and deserve. Midwives have a critical role to play in the collection of FGM related data to assist with health service planning and to prevent FGM by working closely with women and communities they serve to educate and advocate for its abandonment. Therefore, addressing educational gaps and training needs are key strategies to deliver optimal quality of care. Copyright © 2017 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

Obstetric care of women with female genital mutilation attending a specialized clinic in a tertiary center.

PubMed

Abdulcadir, Jasmine; Dugerdil, Adeline; Yaron, Michal; Irion, Olivier; Boulvain, Michel

2016-02-01

To study the obstetric outcomes of women attending a specialized clinic for women with female genital mutilation (FGM). The medical charts of women with FGM who consecutively attended a specialized clinic between 2010 and 2012 were reviewed retrospectively. The present study focused on women attending for obstetric reasons. The outcome measures were type of delivery, reason for cesarean delivery or assisted delivery, blood loss, episiotomy, perineal tear, duration of the second stage of labor, postpartum complications, weight of the neonate, and Apgar score. Outcomes were compared between women with FGM type III who underwent defibulation, and patients with FGM type I and II. The clinic was attended by 129 women, 84 perinatally. Obstetric outcomes were similar to average outcomes for women without FGM presenting at the same department and in Switzerland generally. Specifically, 20 women had a cesarean delivery. An assisted delivery was performed for 18 patients; among these, only eight had experienced obstructed labor. No statistically significant differences were found for the outcome measures when women with FGM type III were compared to FGM type I and II. Routine obstetric follow-up combined with specialized care for women with FGM, including defibulation, can avoid inappropriate obstetric practices and reduce obstetric complications known to be associated with FGM. Copyright © 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Photoelastic investigations of stress concentration in perforated cylindrical shells with internal pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dranchenko, B.N.; Portnov, B.B.; Seleznev, A.V.

1994-06-01

Cylindrical shells with regular perforation are widely used in power generating equipment and in particular in collectors 1 of the circuit of steam generators of power generating installations with water-water reactors (WWPR) The state of stress of collectors is determined by a broad spectrum of technological and operational loads, it is therefore difficult to analyze it theoretically. The aim of the present work is the experimental investigation of stresses in the cylindrical shells of collectors subjected to internal pressure, the generalization and systematization of empirical data in the form of engineering formulas and nomographs. The investigations were carried out withmore » photoelastic three-dimensional models with the use of {open_quotes}freezing{close_quotes}. The basic characteristics of the state of stress of perforated shells (in particular those used in calculations of the strength and life of collectors) are the values of the stress intensity factor K and of the stress intensification factor {gamma}{sub {bar {sigma}}}{sub me} of the mean integral stress level in the neck between neighboring holes. The presented data make it possible to establish quantitatively the regularities of change of K and {gamma}{sub {bar {sigma}}}{sub me} in dependence on the geometry of the perforated shells. These data were systematized according to a special program of multifactor regression analysis. It follows from the presented formulas and nomographs in particular that in the ranges of the geometry of the perforated shells K may change from 2.5 to 4.0, and {gamma}{sub {bar {sigma}}}{sub me} from 1.1 to 2.3. Therefore varied geometric parameters have a substantial effect on the load intensity of perforated shells, and that once again confirms how topical it is to obtain new experimental data, to generalize and systematize them.« less

Dynamic Stability of a Cylindrical Shell Stiffened with a Cylinder and Longitudinal Diaphragms at External Pressure

NASA Astrophysics Data System (ADS)

Bakulin, V. N.; Danilkin, E. V.; Nedbai, A. Ya.

2018-05-01

A study has been made of the dynamic stability of a cylindrical orthotropic shell stiffened with a hollow cylinder and inhomogeneous longitudinal diaphragms under the action of axial forces and pulsating external pressure. The influence of the cylinder and diaphragms on the stability of the shell was taken account of in the form of elastic foundations whose moduli of subgrade reaction are determined from the equations of a three-dimensional theory of elasticity and the Timoshenko model respectively. A solution to the equation of motion of the shell has been found in the form of a trigonometric circumferential-coordinate series. To construct the principal region of instability of the shell, a binomial approximation was used in the obtained Mathieu-Hill equations. As a result, the problem was reduced to a system of two algebraic equations for normal displacement of the shell at diaphragm installation sites. For uniformly spaced identical diaphragms, a solution has been obtained in explicit form. The dependences of the principal region of instability of the shell on the number and rigidity of the diaphragms have been determined at different radii of the cylinder channel.

A retrospective analysis of 34 potentially missed cases of female genital mutilation in the emergency department.

PubMed

Fawcett, Richard John; Kernohan, George

2017-09-12

To discover if healthcare professionals working within an ED are able to make a diagnosis of female genital mutilation (FGM) in those patients who have previously undergone the procedure and report it as per UK law. A retrospective analysis of patients' notes who were assigned an FGM code during the period of May 2015 to August 2016. Single-centre, large UK major trauma centre offering a tertiary FGM clinic. Any woman coded during the study period as having undergone FGM. Number of FGM cases identified by the ED. Mean age, presenting complaint, discharge diagnosis, genitourinary exam and defibulation status. 34 patients were identified as having undergone FGM, 19 had previously attended ED and none had their FGM identified during their ED attendance. The age range of those identified was 23 to 40 years. None had undergone defibulation. This study demonstrates that the identification of FGM victims by an ED is very poor, and more work needs to be done to increase awareness of the subject by front-line staff. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Interventions for healthcare providers to improve treatment and prevention of female genital mutilation: a systematic review.

PubMed

Balfour, Julie; Abdulcadir, Jasmine; Say, Lale; Hindin, Michelle J

2016-08-19

Studies on healthcare providers' awareness, knowledge and attitudes regarding female genital mutilation (FGM) have shown a lack of awareness of the prevalence, diagnosis, and management of FGM. Our objective was to systematically review the literature on interventions improving healthcare providers' capacities of prevention and treatment of FGM. Systematic review of the published and grey literature on interventions aimed at improving healthcare providers' capacities of prevention and treatment of FGM (1995-2015). Outcomes observed were knowledge and attitudes about FGM, medicalization, and prevention. Only two studies met our inclusion criteria. They reported on educational interventions aimed at increasing caregivers' knowledge on FGM. One was conducted with 59 providers, in Mali; the other one with 11 certified nurse-midwives in the United States. The studies report basic statistics regarding the improvement of healthcare professionals' knowledge, attitude on FGM and medicalization of the practice. Neither conducted multivariable analysis nor evaluated the training effects on the quality of the care offered, the clinical outcomes and the satisfaction of women attended, and prevention. As health care providers are essential in prevention and treatment of FGM, developing effective interventions is crucial.

Fluidized bed calciner apparatus

DOEpatents

Owen, Thomas J.; Klem, Jr., Michael J.; Cash, Robert J.

1988-01-01

An apparatus for remotely calcining a slurry or solution feed stream of toxic or hazardous material, such as ammonium diurante slurry or uranyl nitrate solution, is disclosed. The calcining apparatus includes a vertical substantially cylindrical inner shell disposed in a vertical substantially cylindrical outer shell, in which inner shell is disposed a fluidized bed comprising the feed stream material to be calcined and spherical beads to aid in heat transfer. Extending through the outer and inner shells is a feed nozzle for delivering feed material or a cleaning chemical to the beads. Disposed in and extending across the lower portion of the inner shell and upstream of the fluidized bed is a support member for supporting the fluidized bed, the support member having uniform slots for directing uniform gas flow to the fluidized bed from a fluidizing gas orifice disposed upstream of the support member. Disposed in the lower portion of the inner shell are a plurality of internal electric resistance heaters for heating the fluidized bed. Disposed circumferentially about the outside length of the inner shell are a plurality of external heaters for heating the inner shell thereby heating the fluidized bed. Further, connected to the internal and external heaters is a means for maintaining the fluidized bed temperature to within plus or minus approximately 25.degree. C. of a predetermined bed temperature. Disposed about the external heaters is the outer shell for providing radiative heat reflection back to the inner shell.

Deformation of compound shells under action of internal shock wave loading

NASA Astrophysics Data System (ADS)

Chernobryvko, Marina; Kruszka, Leopold; Avramov, Konstantin

2015-09-01

The compound shells under the action of internal shock wave loading are considered. The compound shell consists of a thin cylindrical shell and two thin parabolic shells at the edges. The boundary conditions in the shells joints satisfy the equality of displacements. The internal shock wave loading is modelled as the surplus pressure surface. This pressure is a function of the shell coordinates and time. The strain rate deformation of compound shell takes place in both the elastic and in plastic stages. In the elastic stage the equations of the structure motions are obtained by the assumed-modes method, which uses the kinetic and potential energies of the cylindrical and two parabolic shells. The dynamic behaviour of compound shells is treated. In local plastic zones the 3-D thermo-elastic-plastic model is used. The deformations are described by nonlinear model. The stress tensor elements are determined using dynamic deformation theory. The deformation properties of materials are influenced by the strain rate behaviour, the influence of temperature parameters, and the elastic-plastic properties of materials. The dynamic yield point of materials and Pisarenko-Lebedev's criterion of destruction are used. The modified adaptive finite differences method of numerical analysis is suggested for those simulations. The accuracy of the numerical simulation is verified on each temporal step of calculation and in the case of large deformation gradients.

Magnetic field gradients inferred from multi-point measurements of Cluster FGM and EDI

NASA Astrophysics Data System (ADS)

Teubenbacher, Robert; Nakamura, Rumi; Giner, Lukas; Plaschke, Ferdinand; Baumjohann, Wolfgang; Magnes, Werner; Eichelberger, Hans; Steller, Manfred; Torbert, Roy

2013-04-01

We use Cluster data from fluxgate magnetometer (FGM) and electron drift instrument (EDI) to determine the magnetic field gradients in the near-Earth magnetotail. Here we use the magnetic field data from FGM measurements as well as the gyro-time data of electrons determined from the time of flight measurements of EDI. The results are compared with the values estimated from empirical magnetic field models for different magnetospheric conditions. We also estimated the spin axis offset of FGM based on comparison between EDI and FGM data and discuss the possible effect in determining the current sheet characteristics.

Facts and controversies on female genital mutilation and Islam.

PubMed

Rouzi, Abdulrahim A

2013-02-01

Female genital mutilation (FGM) is a very ancient traditional and cultural ritual. Strategies and policies have been implemented to abandon this practice. However, despite commendable work, it is still prevalent, mainly in Muslim countries. FGM predates Islam. It is not mentioned in the Qur'an (the verbatim word of God in Islam). Muslim religious authorities agree that all types of mutilation, including FGM, are condemned. 'Sensitivity' to cultural traditions that erroneously associate FGM with Islam is misplaced. The principle of 'do no harm', endorsed by Islam, supersedes cultural practices, logically eliminating FGM from receiving any Islamic religious endorsement.

Buckling Behavior of Compression-Loaded Composite Cylindrical Shells with Reinforced Cutouts

NASA Technical Reports Server (NTRS)

Hilburger, Mark W.; Starnes, James H., Jr.

2002-01-01

Results from a numerical study of the response of thin-wall compression-loaded quasi-isotropic laminated composite cylindrical shells with reinforced and unreinforced square cutouts are presented. The effects of cutout reinforcement orthotropy, size, and thickness on the nonlinear response of the shells are described. A high-fidelity nonlinear analysis procedure has been used to predict the nonlinear response of the shells. The analysis procedure includes a nonlinear static analysis that predicts stable response characteristics of the shells and a nonlinear transient analysis that predicts unstable dynamic buckling response characteristics. The results illustrate how a compression-loaded shell with an unreinforced cutout can exhibit a complex nonlinear response. In particular, a local buckling response occurs in the shell near the cutout and is caused by a complex nonlinear coupling between local shell-wall deformations and in-plane destabilizing compression stresses near the cutout. In general, the addition of reinforcement around a cutout in a compression-loaded shell can retard or eliminate the local buckling response near the cutout and increase the buckling load of the shell, as expected. However, results are presented that show how certain reinforcement configurations can actually cause an unexpected increase in the magnitude of local deformations and stresses in the shell and cause a reduction in the buckling load. Specific cases are presented that suggest that the orthotropy, thickness, and size of a cutout reinforcement in a shell can be tailored to achieve improved response characteristics.

Understanding the motivations of health-care providers in performing female genital mutilation: an integrative review of the literature.

PubMed

Doucet, Marie-Hélène; Pallitto, Christina; Groleau, Danielle

2017-03-23

Female genital mutilation (FGM) is a traditional harmful practice that can cause severe physical and psychological damages to girls and women. Increasingly, trained health-care providers carry out the practice at the request of families. It is important to understand the motivations of providers in order to reduce the medicalization of FGM. This integrative review identifies, appraises and summarizes qualitative and quantitative literature exploring the factors that are associated with the medicalization of FGM and/or re-infibulation. Literature searches were conducted in PubMed, CINAHL and grey literature databases. Hand searches of identified studies were also examined. The "CASP Qualitative Research Checklist" and the "STROBE Statement" were used to assess the methodological quality of the qualitative and quantitative studies respectively. A total of 354 articles were reviewed for inclusion. Fourteen (14) studies, conducted in countries where FGM is largely practiced as well as in countries hosting migrants from these regions, were included. The main findings about the motivations of health-care providers to practice FGM were: (1) the belief that performing FGM would be less harmful for girls or women than the procedure being performed by a traditional practitioner (the so-called "harm reduction" perspective); (2) the belief that the practice was justified for cultural reasons; (3) the financial gains of performing the procedure; (4) responding to requests of the community or feeling pressured by the community to perform FGM. The main reasons given by health-care providers for not performing FGM were that they (1) are concerned about the risks that FGM can cause for girls' and women's health; (2) are preoccupied by the legal sanctions that might result from performing FGM; and (3) consider FGM to be a "bad practice". The findings of this review can inform public health program planners, policy makers and researchers to adapt or create strategies to end medicalization of FGM in countries with high prevalence of this practice, as well as in countries hosting immigrants from these regions. Given the methodological limitations in the included studies, it is clear that more robust in-depth qualitative studies are needed, in order to better tackle the complexity of this phenomenon and contribute to eradicating FGM throughout the world.

Preparation and Ablating Behavior of FGM used in a Heat Flux Rocket Engine

NASA Astrophysics Data System (ADS)

He, Xiaodong; Han, Jiecai; Zhang, Xinghong

2002-01-01

Functionally Graded Material (FGM) is a new kind of nonhomogeneous materials, which composition varies gradually and continuously from metals to ceramics, thus excellence of both ceramic and metal is brought fully into play. The impetus for the development of FGM was to make thermal barrier materials for space shuttles and structure such as combustion chamber, gas vane, air vane, nose cone, fuel valve sheets and piston crown. There are several main techniques for making FGMs including chemical vapor deposition (CVD), powder metallurgy, plasma spraying and self-propagating high temperate synthesis (SHS). SHS Technology is the process by which condensed phases are produced by self - sustaining exothermic chemical reaction. Demonstrated advantages of SHS as a method for the preparation of materials include higher purity of the products, low energy requirements, and the relative simplicity of the process. SHS is particularly well suited to fabricating FGM. Due to the rapidity of the combustion reaction, the initial arrangement of the constituent in the green body is unchanged during combustion. In this paper, TiB2-Cu FGM and homogeneous cermets have been prepared by combing forced compaction with SHS. The experimental results show that process parameters significantly influence the combustion synthesis procedure of Ti-B-Cu system. Optimal process parameters have been gained for preparing TiB2-Cu FGM and cermets. TiB2-Cu FGM by SHS has a continuous distribution in microstructure along its thickness. The macroscopic interface of ceramic/metal joint is elemented. Mechanical properties of TiB2-Cu cermets were investigated at room and high temperature. The thermal stress of TiC-Ni FGM prepared by SHS are simulated at working condition, as well as comparing with a layered TiB2-Cu Non- FGM. Obviously, the TiB2-Cu FGM has the function of distortion and thermal stress relation. TiB2-Cu FGM was tested in the limited wind tunnel simulating the real condition of the heat flux rocket engine. As a result, TiB2-Cu FGM showed excellent resistant ablating properties. There is only a little loss of the mass after heated for 40 seconds in the wind tunnel. Meanwhile no cracks and breakup appeared in the FGM under the sharp thermal shock condition. Key words: functionally graded materials, combustion synthesis, ablation, thermal shock, thermal stress

The mothering experience of women with FGM/C raising 'uncut' daughters, in Ivory Coast and in Canada.

PubMed

Koukoui, Sophia; Hassan, Ghayda; Guzder, Jaswant

2017-04-05

While Female Genital Cutting (FGM/C) is a deeply entrenched cultural practice, there is now mounting evidence for a gradual decline in prevalence in a number of geographical areas in Africa and following migration to non-practicing countries. Consequently, there is now a growing number of women with FGM/C who are raising 'uncut' daughters. This study used a qualitative methodology to investigate the experience of women with FGM/C raising daughters who have not been subjected to the ritual. The aim of this study was to shed light on mothers' perception of the meaning and cultural significance of the practice and to gain insight into their mothering experience of 'uncut' girls. To this end, in-depth interviews were conducted with fifteen mothers living in Abidjan, Ivory Coast and in Montreal, Canada (8 and 7, respectively). Thirteen mothers intrinsically refused to perpetuate FGM/C onto their daughters and two diasporic mothers were in favour of FGM/C but forewent the practice for fear of legal repercussions. Whether the eschewing of FGM/C was deliberate or legally imposed, raising 'uncut' daughters had significant consequences in terms of women's mothering experiences. Mothers faced specific challenges pertaining to community and family pressure to have daughters undergo FGM/C, and expressed concerns regarding their daughters' sexuality. Conversely, women's narratives were also infused with pride and hope for their daughters, and revealed an accrued dialogue between the mother-daughter dyad about cultural norms and sexuality. Interestingly, women's mothering experience was also bolstered by the existence of informal networks of support between mothers with FGM/C whose daughters were 'uncut'. These communities of mothers engaged in open dialogue about the consequences of FGM/C and offered reciprocal solidarity and support in their decision to forego FGM/C for their children. Women with FGM/C who are raising 'uncut' daughters in their homeland and in their country of immigration vastly report a positive experience. However, they also face specific challenges related to immigration, psychosocial, and psychosexual considerations, which must be tackled from a multidisciplinary perspective.

Bending Boundary Layers in Laminated-Composite Circular Cylindrical Shells

NASA Technical Reports Server (NTRS)

Nemeth, Michael P.; Smeltzer, Stanley S., III

2000-01-01

A study of the attenuation of bending boundary layers in balanced and unbalanced, symmetrically and unsymmetrically laminated cylindrical shells is presented for nine contemporary material systems. The analysis is based on the linear Sanders-Koiter shell equations and specializations to the Love-Kirchhoff shell equations and Donnell's equations are included. Two nondimensional parameters are identified that characterize the effects of laminate orthotropy and anisotropy on the bending boundary-layer decay length in a very general manner. A substantial number of structural design technology results are presented for a wide range of laminated-composite cylinders. For all laminates considered, the results show that the differences between results obtained with the Sanders-Koiter shell equations, the Love-Kirchhoff shell equations, and Donnell's equations are negligible. The results also show that the effect of anisotropy in the form of coupling between pure bending and twisting has a negligible effect on the size of the bending boundary-layer decay length of the balanced, symmetrically laminated cylinders considered. Moreover, the results show that coupling between the various types of shell anisotropies has a negligible effect on the calculation of the bending boundary-layer decay length in most cases. The results also show that, in some cases, neglecting the shell anisotropy results in underestimating the bending boundary-layer decay length and, in other cases, results in an overestimation.

Characterization and prediction of the backscattered form function of an immersed cylindrical shell using hybrid fuzzy clustering and bio-inspired algorithms.

PubMed

Agounad, Said; Aassif, El Houcein; Khandouch, Younes; Maze, Gérard; Décultot, Dominique

2018-02-01

The acoustic scattering of a plane wave by an elastic cylindrical shell is studied. A new approach is developed to predict the form function of an immersed cylindrical shell of the radius ratio b/a ('b' is the inner radius and 'a' is the outer radius). The prediction of the backscattered form function is investigated by a combined approach between fuzzy clustering algorithms and bio-inspired algorithms. Four famous fuzzy clustering algorithms: the fuzzy c-means (FCM), the Gustafson-Kessel algorithm (GK), the fuzzy c-regression model (FCRM) and the Gath-Geva algorithm (GG) are combined with particle swarm optimization and genetic algorithm. The symmetric and antisymmetric circumferential waves A, S 0 , A 1 , S 1 and S 2 are investigated in a reduced frequency (k 1 a) range extends over 0.1

Psychopathological sequelae of female genital mutilation and their neuroendocrinological associations.

PubMed

Köbach, Anke; Ruf-Leuschner, Martina; Elbert, Thomas

2018-06-13

Anecdotal evidence suggests the frequently traumatic nature of female genital mutilation (FGM). At present, systematic research on the psychological sequelae of this tradition has remained limited. The study provides preliminary, high-quality psychodiagnostic data on potential psychopathological consequences of FGM, with a focus on posttraumatic stress disorder (PTSD), shutdown dissociation and other stress-related variables. We investigated a convenience sample of N = 167 women, supported by the women's affairs headquarters in Jijiga (capital of the Ethiopian Somali Region) and a local Ethiopian non-governmental organization. Our main outcome measures were PTSD (PSS-I) and shutdown dissociation (ShuD). We also assessed depression and anxiety (HSCL-25), major depression, substance abuse and dependence, suicidality and psychotic disorders (M.I.N.I.; sub-scales A., B., K., and L.). In addition, we collected hair samples to assess hair cortisol concentrations (HCC) as a neuroendocrinological measure. The majority of women endured FGM (FGM I: 36%, FGM II/III: 52%) and, regardless of the level of the physical invasiveness, almost all women reported having felt intense fear and/or helplessness. FGM II/III, the more invasive form, was associated with a greater vulnerability to PTSD symptoms (p < .001) and shutdown dissociation (p < .001). Symptoms of depression (p < .05) and anxiety (p < .01) were also elevated. Random forest regression with conditional inference trees revealed evidence of an alteration of the cortisol levels in relation to the age when FGM was experienced (< 1 year) and the invasiveness of the procedure. More extensive forms of FGM are associated with more severe psychopathological symptoms - particularly with an increased vulnerability to PTSD. Higher hair cortisol levels in women who experienced FGM before their first year of age or had more severe forms of FGM indicate long-term neuroendocrinological consequences of FGM and trauma in general on the stress system.

Female genital mutilation in children presenting to Australian paediatricians.

PubMed

Zurynski, Yvonne; Phu, Amy; Sureshkumar, Premala; Cherian, Sarah; Deverell, Marie; Elliott, Elizabeth J

2017-06-01

The WHO reports that female genital mutilation/cutting (FGM/C) is an ancient cultural practice prevalent in many countries. FGM/C has been reported among women resident in Australia. Our paper provides the first description of FGM/C in Australian children. Cross-sectional survey conducted in April-June 2014. Paediatricians and other child health specialists recruited through the Australian Paediatric Surveillance Unit were asked to report children aged <18 years with FGM/C seen in the last 5 years, and to provide data for demographics, FGM/C type, complications and referral for each case. Of 1311 eligible paediatricians/child health specialists, 1003 (76.5%) responded. Twenty-three (2.3%) respondents had seen 59 children with FGM/C and provided detailed data for 31. Most (89.7%) were identified during refugee screening and were born in Africa. Three (10.3%) were born in Australia: two had FGM/C in Australia and one in Indonesia. All parents were born overseas, mainly Africa (98.1%). Ten children had WHO FGM/C type I, five type II, five type III and six type IV. Complications in eight children included recurrent genitourinary infections, menstrual, sexual, fertility and psychological problems. Nineteen children (82.6%) were referred to obstetrics/gynaecology: 16 (69.9%) to social work and 13 (56.5%) to child protection. This study confirms that FGM/C is seen in paediatric clinical practice within Australia. Paediatricians need cultural awareness, education and resources to help them identify children with FGM/C and/or at risk of FGM/C, to enable appropriate referral and counselling of children, families and communities to assist in the prevention of this practice. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Estimating the prevalence of female genital mutilation in Portugal.

PubMed

Teixeira, A L; Lisboa, M

2016-10-01

Due to globalized migratory processes, female genital mutilation/cutting (FGM/C) has spread to other countries, including countries in Europe, where, with a few exceptions, it remains a concealed problem. To the authors' knowledge, this is the first national extensive study to estimate the prevalence of FGM/C in Portugal. Prevalence estimation. Using extrapolation of country-of-origin prevalence data and the 2011 Census data, this study estimated: the prevalence of FGM/C in Portugal among women of reproductive age (15-49 years) and among all women aged ≥15 years; and the number of girls aged <15 years living in Portugal who have undergone or will probably undergo FGM/C. It is estimated that 6576 women aged ≥15 years living in Portugal have undergone FGM/C, with cases distributed unevenly throughout the national territory. In addition, it is estimated that 1830 girls aged <15 years living in Portugal have undergone or are likely to undergo FGM/C. This study estimated that more than 6000 women living in Portugal have undergone FGM/C, and many girls remain at risk. These two groups need different types of interventions. Awareness of the number and geographical dispersion of cases of FGM/C will enable more informed and targeted definition of public health policies for protection of females who have undergone or are at risk of undergoing FGM/C. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Midwives' experiences of caring for women with female genital mutilation: Insights and ways forward for practice in Australia.

PubMed

Dawson, A J; Turkmani, S; Varol, N; Nanayakkara, S; Sullivan, E; Homer, C S E

2015-09-01

Female genital mutilation (FGM) has serious health consequences, including adverse obstetric outcomes and significant physical, sexual and psychosocial complications for girls and women. Migration to Australia of women with FGM from high-prevalence countries requires relevant expertise to provide women and girls with FGM with specialised health care. Midwives, as the primary providers of women during pregnancy and childbirth, are critical to the provision of this high quality care. To provide insight into midwives' views of, and experiences working with, women affected by FGM. A descriptive qualitative study was undertaken using focus group discussions with midwives from four purposively selected antenatal clinics and birthing units in three hospitals in urban New South Wales. The transcripts were analysed thematically. Midwives demonstrated knowledge and recalled skills in caring for women with FGM. However, many lacked confidence in these areas. Participants expressed fear and a lack of experience caring for women with FGM. Midwives described practice issues, including the development of rapport with women, working with interpreters, misunderstandings about the culture of women, inexperience with associated clinical procedures and a lack of knowledge about FGM types and data collection. Midwives require education, training and supportive supervision to improve their skills and confidence when caring for women with FGM. Community outreach through improved antenatal and postnatal home visitation can improve the continuity of care provided to women with FGM. Copyright © 2015 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

Contact interaction of thin-walled elements with an elastic layer and an infinite circular cylinder under torsion

NASA Astrophysics Data System (ADS)

Kanetsyan, E. G.; Mkrtchyan, M. S.; Mkhitaryan, S. M.

2018-04-01

We consider a class of contact torsion problems on interaction of thin-walled elements shaped as an elastic thin washer – a flat circular plate of small height – with an elastic layer, in particular, with a half-space, and on interaction of thin cylindrical shells with a solid elastic cylinder, infinite in both directions. The governing equations of the physical models of elastic thin washers and thin circular cylindrical shells under torsion are derived from the exact equations of mathematical theory of elasticity using the Hankel and Fourier transforms. Within the framework of the accepted physical models, the solution of the contact problem between an elastic washer and an elastic layer is reduced to solving the Fredholm integral equation of the first kind with a kernel representable as a sum of the Weber–Sonin integral and some integral regular kernel, while solving the contact problem between a cylindrical shell and solid cylinder is reduced to a singular integral equation (SIE). An effective method for solving the governing integral equations of these problems are specified.

Investigation of Collapse Characteristics of Cylindrical Composite Panels with Large Cutouts

DTIC Science & Technology

1989-12-01

COLLAPSE CHARACTERISTICS OF CYLINDRICAL COMPOSITE PANELS WITH LARGE CUTOUTS THESIS Scott A. Schimmels Captain, USAF AFIT/GAE/ENY/89D-33 Approved for...public release, distribution unlimited AFIT/GAE/ENY/89D-33 INVESTIGATION OF COLLAPSE * CHARACTERISTICS OF CYLINDRICAL COMPOSITE PANELS WITH LARGE...you would not be reading this. * This thesis research is part of an overall effort in composite nonlinear shell analysis sponsored by AFOSR, Dr

The Obstetric Consequences of Female Genital Mutilation/Cutting: A Systematic Review and Meta-Analysis

PubMed Central

Berg, Rigmor C.; Underland, Vigdis

2013-01-01

Various forms of female genital mutilation/cutting (FGM/C) have been performed for millennia and continue to be prevalent in parts of Africa. Although the health consequences following FGM/C have been broadly investigated, divergent study results have called into question whether FGM/C is associated with obstetric consequences. To clarify the present state of empirical research, we conducted a systematic review of the scientific literature and quantitative meta-analyses of the obstetric consequences of FGM/C. We included 44 primary studies, of which 28 were comparative, involving almost 3 million participants. The methodological study quality was generally low, but several studies reported the same outcome and were sufficiently similar to warrant pooling of effect sizes in meta-analyses. The meta-analyses results showed that prolonged labor, obstetric lacerations, instrumental delivery, obstetric hemorrhage, and difficult delivery are markedly associated with FGM/C, indicating that FGM/C is a factor in their occurrence and significantly increases the risk of delivery complications. There was no significant difference in risk with respect to cesarean section and episiotomy. These results can make up the background documentation for health promotion and health care decisions that inform work to reduce the prevalence of FGM/C and improve the quality of services related to the consequences of FGM/C. PMID:23878544

Female genital mutilation in Greece.

PubMed

Vrachnis, N; Salakos, N; Iavazzo, C; Iliodromiti, Z; Bakalianou, K; Kouiroukidou, P; Creatsas, G

2012-01-01

The number of migrants and refugees with a female genital mutilation (FGM) living in Greece is rising. This study explores the characteristics and psychosexual issues of women with FGM who were examined in the 2nd Department of Obstetrics and Gynecology, University of Athens Medical School, Greece during the year 2009. The women were asked to fill out an anonymous questionnaire asking for demographic data, obstetric history, current complaints, and psychosexual problems. The results are presented and discussed, as FGM is a new reality for Greece. Healthcare providers have to familiarize themselves with issues related to FGM and improve their skills in transcultural care, so as to manage and support women with FGM adequately.

Elasto-plastic impact of hemispherical shell impacting on hard rigid sphere

NASA Technical Reports Server (NTRS)

Raftopoulos, D. D.; Spicer, A. L.

1976-01-01

An analysis of plastic stress waves for cylindrical metallic projectile in impact is extended to an analysis of a hemispherical shell suffereing plastic deformation during the process of impact. It is assumed that the hemispherical shell with a prescribed launch velocity impinges a fixed rigid sphere of diameter equal to the internal diameter of the shell. The dynamic biaxial state of stress present in the shell during deformation is investigated. The analysis is valuable for studying the state of stress during large plastic deformation of a hemispherical shell.

Magnetization processes in core/shell exchange-spring structures.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, J. S.

2015-03-27

The magnetization reversal processes in cylindrical and spherical soft core/hard shell exchange-spring structures are investigated via the analytical nucleation theory, and are verified with numerical micromagnetic simulations. At small core sizes, the nucleation of magnetic reversal proceeds via the modified bulging mode, where the transverse component of the magnetization is only semi-coherent in direction and the nucleation field contains a contribution from self-demagnetization. For large core sizes, the modified curling mode, where the magnetization configuration is vortex-like, is favored at nucleation. The preference for the modified curling mode is beneficial in that the fluxclosure allows cylindrical and spherical core/shell exchange-springmore » elements to be densely packed into bulk permanent magnets without affecting the nucleation field, thereby offering the potential for high energy product.« less

A numerical comparison with an exact solution for the transient response of a cylinder immersed in a fluid. [computer simulated underwater tests to determine transient response of a submerged cylindrical shell

NASA Technical Reports Server (NTRS)

Giltrud, M. E.; Lucas, D. S.

1979-01-01

The transient response of an elastic cylindrical shell immersed in an acoustic media that is engulfed by a plane wave is determined numerically. The method applies to the USA-STAGS code which utilizes the finite element method for the structural analysis and the doubly asymptotic approximation for the fluid-structure interaction. The calculations are compared to an exact analysis for two separate loading cases: a plane step wave and an exponentially decaying plane wave.

The relationship between female genital mutilation and HIV transmission in sub-Saharan Africa.

PubMed

Olaniran, Abimbola A

2013-12-01

Female genital mutilation (FGM) is an age-old practice that has since been linked with many health problems. This review aims to highlight some of the controversies trailing the relationship between FGM and HIV transmission in sub-Saharan Africa. A literature search was conducted on the subject matter. This was done using articles published in English while limiting the geographical coverage to sub-Saharan Africa. Three themes were noted. These themes include: Direct causal link between FGM and HIV transmission; indirect causal link between FGM and HIV transmission and a negative or no association between FGM and HIV transmission. While many of the arguments are within scientific reasoning, the researches supporting the views seem to lack the necessary objectivity. This study underscored the need for a more objective lens in viewing and conducting research on the relationship between FGM and HIV transmission in sub-Saharan Africa.

Female genital mutilation/cutting: risk management and strategies for social workers and health care professionals

PubMed Central

Costello, Susan

2015-01-01

Female genital mutilation/cutting (FGM/C) is a traditional practice originating in Africa. Its worst forms cause irreparable harm to girls and women and have no medical justification. Based on a literature review of global responses to FGM/C and conversations with Australian women who migrated from FGM/C practicing countries, this paper provides some background on FGM/C and its epidemiology, outlining its prevalence, types, and health risks and complications for women and girls. It discusses risk-prevention strategies, first, for health practitioners in identifying, screening, and supporting women affected by FGM/C and, second, for welfare and social workers and health care professionals to identify, work with, and prevent girls from being cut. Consistent with international trends in addressing the risks of FGM/C, the paper suggests practice responses for coordinated responses between professionals, communities from practicing countries, and governments of different countries. PMID:26719732

Functionally gradient material of the system Ni-MgO, Ni-NiO, Ni-Si3N4 or Al-AlN, by pressureless sintering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Atarashiya, Koji; Kurokawa, Kazuya; Nagai, Tadao

1992-08-01

Generally speaking, the preparation of FGM-blocks, especially in the metal-nitride systems, by the method of powder metallurgy needs an extremely high temperature and high pressure. But, in this work using a ductile nickel metal powder or an ultrafine particle, the FGM-blocks were easily prepared using a powder metallurgy at a lower temperature. A mixture of a metallic powder and a non-metallic powder whose contents were gradually changed was pressed in a steel die under pressure of 20-32 MPa. These green compacts were heated at 900-1573 K in controlled atmosphere under null pressure. The FGM-blocks prepared by this method were characterizedmore » by their properties and were used in joinings. The joinings of metal/FGM/ceramics, metal/FGM and ceramics/FGM were completely accomplished at 900-1573 K. 6 refs.« less

Multi-parameter actuation of a neutrally stable shell: a flexible gear-less motor.

PubMed

Hamouche, W; Maurini, C; Vidoli, S; Vincenti, A

2017-08-01

We have designed and tested experimentally a morphing structure consisting of a neutrally stable thin cylindrical shell driven by a multi-parameter piezoelectric actuation. The shell is obtained by plastically deforming an initially flat copper disc, so as to induce large isotropic and almost uniform inelastic curvatures. Following the plastic deformation, in a perfectly isotropic system, the shell is theoretically neutrally stable, having a continuous set of stable cylindrical shapes corresponding to the rotation of the axis of maximal curvature. Small imperfections render the actual structure bistable, giving preferred orientations. A three-parameter piezoelectric actuation, exerted through micro-fibre-composite actuators, allows us to add a small perturbation to the plastic inelastic curvature and to control the direction of maximal curvature. This actuation law is designed through a geometrical analogy based on a fully nonlinear inextensible uniform-curvature shell model. We report on the fabrication, identification and experimental testing of a prototype and demonstrate the effectiveness of the piezoelectric actuators in controlling its shape. The resulting motion is an apparent rotation of the shell, controlled by the voltages as in a 'gear-less motor', which is, in reality, a precession of the axis of principal curvature.

Multi-parameter actuation of a neutrally stable shell: a flexible gear-less motor

NASA Astrophysics Data System (ADS)

Hamouche, W.; Maurini, C.; Vidoli, S.; Vincenti, A.

2017-08-01

We have designed and tested experimentally a morphing structure consisting of a neutrally stable thin cylindrical shell driven by a multi-parameter piezoelectric actuation. The shell is obtained by plastically deforming an initially flat copper disc, so as to induce large isotropic and almost uniform inelastic curvatures. Following the plastic deformation, in a perfectly isotropic system, the shell is theoretically neutrally stable, having a continuous set of stable cylindrical shapes corresponding to the rotation of the axis of maximal curvature. Small imperfections render the actual structure bistable, giving preferred orientations. A three-parameter piezoelectric actuation, exerted through micro-fibre-composite actuators, allows us to add a small perturbation to the plastic inelastic curvature and to control the direction of maximal curvature. This actuation law is designed through a geometrical analogy based on a fully nonlinear inextensible uniform-curvature shell model. We report on the fabrication, identification and experimental testing of a prototype and demonstrate the effectiveness of the piezoelectric actuators in controlling its shape. The resulting motion is an apparent rotation of the shell, controlled by the voltages as in a `gear-less motor', which is, in reality, a precession of the axis of principal curvature.

Estimates of first-generation women and girls with female genital mutilation in the European Union, Norway and Switzerland.

PubMed

Van Baelen, Luk; Ortensi, Livia; Leye, Els

2016-12-01

Female genital mutilation (FGM) is the practice of partial or total removal of female genitalia for non-medical reasons. The procedure has no known health benefits but can cause serious immediate and long-term obstetric, gynaecological and sexual health problems. Health workers in Europe are often unaware of the consequences of FGM and lack the knowledge to treat women adequately. Our goal was to estimate the number of first-generation girls and women in the European Union, Norway and Switzerland who have undergone FGM. Before migration from FGM-practicing countries began, FGM was an unknown phenomenon in Europe. Secondary analysis of data from the 2011 EU census and extrapolation from age-specific FGM prevalence rates in the immigrants' home countries to these data were used to provide our estimates. Estimates based on census and other demographic data were compared to our results for Belgium. In 2011 over half a million first-generation women and girls in the EU, Norway and Switzerland had undergone FGM before immigration. One in two was living in the UK or France, one in two was born in East-Africa. For the first time, scientific evidence gives a reliable estimate of the number of first-generation women and girls in Europe coming from countries where FGM is practiced. The use of census data proves reliable for policy makers to guide their actions, e.g., regarding training needs for health workers who might be confronted with women who have undergone FGM, or the need for reconstructive surgery.

Female genital mutilation and cutting: a systematic literature review of health professionals' knowledge, attitudes and clinical practice.

PubMed

Zurynski, Yvonne; Sureshkumar, Premala; Phu, Amy; Elliott, Elizabeth

2015-12-10

The World Health Organisation (WHO) estimates that 100-140 million girls and women have undergone female genital mutilation or cutting (FGM/C). FGM/C is an ancient cultural practice prevalent in 26 countries in Africa, the Middle East and Asia. With increased immigration, health professionals in high income countries including UK, Europe, North America and Australia care for women and girls with FGM/C. FGM/C is relevant to paediatric practice as it is usually performed in children, however, health professionals' knowledge, clinical practice, and attitudes to FGM/C have not been systematically described. We aimed to conduct a systematic review of the literature to address this gap. The review was conducted according to guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and registered with the PROSPERO International Prospective Register of Systematic Reviews (CRD42015015540, http://www.crd.york.ac.uk/PROSPERO/). Articles published in English 2000-2014 which used quantitative methods were reviewed. Of 159 unique articles, 18 met inclusion criteria. The methodological quality was poor - six studies met seven of the eight quality criteria. Study participants included mainly obstetricians, gynaecologists and midwives (15 studies). We found no papers that studied paediatricians specifically, but two papers reported on subgroups of paediatricians within a mixed sample of health professionals. The 18 articles covered 13 different countries: eight from Africa and 10 from high income countries. Most health professionals were aware of the practice of FGM/C, but few correctly identified the four FGM/C categories defined by WHO. Knowledge about FGM/C legislation varied: 25% of professionals in a Sudanese study, 46 % of Belgian labour ward staff and 94 % of health professionals from the UK knew that FGM/C was illegal in their country. Health professionals from high income countries had cared for women or girls with FGM/C. The need to report children with FGM/C, or at risk of FGM/C, to child protection authorities was mentioned by only two studies. Further research is needed to determine health professionals' attitudes, knowledge and practice to support the development of educational materials and policy to raise awareness and to prevent this harmful practice.

Bibliometric analysis of literature on female genital mutilation: (1930 - 2015).

PubMed

Sweileh, Waleed M

2016-10-10

Female genital mutilation/cutting (FGM/C) is a common harmful traditional practice in many communities in Africa and to a lesser extent in Middle East and other regions in the world. In order to better understand publishing on this topic, we conducted a bibliometric study on FGM/C. Bibliometric analyses can be used as an indicator of the extent of interaction of researchers, health authorities, and communities with a particular health issue. Scopus database was used to retrieve data on FGM/C. Keywords used were "female genital mutilation", "female genital circumcision", "female genital cutting" and "female circumcision". Specifically, the number of publications, top productive countries and institutions, highly cited articles, citation analysis, co-authorships, international collaboration, role of African countries, top active authors, and journals involved in publishing articles on FGM/C were reviewed and analyzed. We indirectly assessed the impact of publications using total number of citations received, average number of citations per article, Hirsch-index, percentage of highly cited articles, and journal's impact factor. One thousand and thirty-five publications on FGM/C were retrieved. The h-index of retrieved articles was 37. A steep rise in number of publications was noticed in mid-1990s and again in 2012. More than half of retrieved articles were published from 2006 - 2015. A total of 65 countries contributed. The top ten productive countries included ones from Northern America, Europe and Africa. Nigeria and Egypt were the most active African countries in FGM/C publications. At least nine African academic institutions were actively involved on FGM/C publications. Articles on FGM/C that received the highest number of citations were those that focused on negative physical and psychosexual consequences of FGM/C. Journal topic areas were obstetrics/gynecology, public health, and psychological sociology. Collaboration between African and European countries on FGM/C research was evident. Bibliometric analysis reveals that research publications on FGM/C have been increasing since the l970s, with collaboration between African and Western countries, and articles are being published in higher impact journals, not only obstetrics, but also public health and social sciences. FGM/C research can be helpful to international health agencies and governments not only to document negative outcomes, but also to identify best practices, and to note gaps in implementation and practice.

What do we know about assessing healthcare students and professionals' knowledge, attitude and practice regarding female genital mutilation? A systematic review.

PubMed

Abdulcadir, Jasmine; Say, Lale; Pallitto, Christina

2017-05-22

Improving healthcare providers' capacities of prevention and treatment of female genital mutilation (FGM) is important given the fact that 200 million women and girls globally are living with FGM. However, training programs are lacking and often not evaluated. Validated and standardized tools to assess providers' knowledge, attitude and practice (KAP) regarding FGM are lacking. Therefore, little evidence exists on the impact of training efforts on healthcare providers' KAP on FGM. The aim of our paper is to systematically review the available published and grey literature on the existing quantitative tools (e.g. scales, questionnaires) measuring healthcare students' and providers' KAP on FGM. We systematically reviewed the published and grey literature on any quantitative assessment/measurement/evaluation of KAP of healthcare students and providers about FGM from January 1 st , 1995 to July 12 th , 2016. Twenty-nine papers met our inclusion criteria. We reviewed 18 full text questionnaires implemented and administered to healthcare professionals (students, nurses, midwives and physicians) in high and low income countries. The questionnaires assessed basic KAP on FGM. Some included personal and cultural beliefs, past clinical experiences, personal awareness of available clinical guidelines and laws, previous training on FGM, training needs, caregiver's confidence in management of women with FGM, communication and personal perceptions. Identified gaps included the medical, psychological or surgical treatments indicated to improve girls and women's health; correct diagnosis, recording ad reporting capacities; clitoral reconstruction and psychosexual care of circumcised women. Cultural and personal beliefs on FGM were investigated only in high prevalence countries. Few questionnaires addressed care of children, child protection strategies, treatment of short-term complications, and prevention. There is a need for implementation and testing of interventions aimed at improving healthcare professionals' and students' capacities of diagnosis, care and prevention of FGM. Designing tools for measuring the outcomes of such interventions is a critical aspect. A unique, reproducible and standardized questionnaire could be created to measure the effect of a particular training program. Such a tool would also allow comparisons between settings, countries and interventions. An ideal tool would test the clinical capacities of providers in managing complications and communicating with clients with FGM as well as changes in KAP.

Scattering of plane evanescent waves by cylindrical shells and wave vector coupling conditions for exciting flexural waves

NASA Astrophysics Data System (ADS)

Marston, Philip L.

2002-05-01

The coupling of sound to buried targets can be associated with acoustic evanescent waves when the sea bottom is smooth. To understand the excitation of flexural waves on buried shells by acoustic evanescent waves, the partial wave series for the scattering is found for cylindrical shells at normal incidence in an unbounded medium. The formulation uses the simplifications of thin-shell dynamics. In the case of ordinary waves incident on a shell, a ray formulation is available to describe the coupling to subsonic flexural waves [P. L. Marston and N. H. Sun, J. Acoust. Soc. Am. 97, 777-783 (1995)]. When the incident wave is evanescent, the distance between propagating plane wavefronts is smaller than the ordinary acoustical wavelength at the same frequency and the coupling condition for the excitation of flexural waves on shells or plates is modified. Instead of matching the flexural wave number with the propagating part of the acoustic wave number only at the coincidence frequency, a second low-frequency wave number matching condition is found for highly evanescent waves. Numerical evaluation of the modified partial-wave-series appropriate for an evanescent wave is used to investigate the low-frequency coupling of evanescent waves with flexural wave resonances of shells.

Female Genital Mutilation as a Concern for Special Operations and Tactical Emergency Medical Support Medics.

PubMed

Wittich, Arthur C

Female genital mutilation (FGM), frequently called female genital cutting or female circumcision, is the intentional disfigurement of the external genitalia in young girls and women for the purpose of reducing libido and ensuring premarital virginity. This traditional, nontherapeutic procedure to suppress libido and prevent sexual intercourse before marriage has been pervasive in Northern Africa, the Middle East, and the Arabian peninsula for over 2,500 years. FGM permanently destroys the genital anatomy while frequently causing multiple and serious complications. The International Federation of Gynecology and Obstetrics proposed a classification system of FGM according to the specific genital anatomy removed and the extensiveness of genital disfigurement. Although it has been ruled illegal in most countries, FGM continues to be performed worldwide. With African, Asian, and Middle Eastern immigration to the United States and Europe, western countries are experiencing FGM in regions where these immigrants have concentrated. As deployments of Special Operations Forces (SOF) increase to regions in which FGM is pervasive, and as African, Asian, and Middle Eastern immigration to the United States increases, SOF and Tactical Emergency Medical Support (TEMS) medics will necessarily be called upon to evaluate and treat complications resulting from FGM. The purpose of this article is to educate SOF/TEMS medical personnel about the history, geographic regions, classification of procedures, complications, and medical treatment of patients with FGM. 2017.

African, male attitudes on female genital mutilation: an Australian survey.

PubMed

Shahid, Usama; Rane, Ajay

2017-11-01

Female genital mutilation (FGM) is a traditional practice where female genital organs are altered for non-medical reasons. The custom is outlawed in Australia and associated with an array of medical consequences. Due to the recent influx of migrants from regions endemic to FGM, the practice is becoming a growing concern locally. This federal government funded study aimed to elicit the poorly understood perceptions that young, Sub-Saharan African, migrant males residing in Townsville, Australia have on FGM. Through piloted questionnaires we found that amongst the 67 participants, 23.9% believed that FGM should be allowed under Australian Law. The independent predictors of supportive attitudes in favour of FGM were having resided in Australia for five or less years (p = .016, 95% CI 0.99-8.09) and coming from a basic educational background (high school or TAFE) (p = .003, 95% CI 1.3-12.4). This study also found that participant perceptions on FGM were amenable to change through educational interventional strategies. Impact statement Female genital mutilation (FGM) is a traditional practice where female genital organs are altered for non-medical reasons. The role that males play in the continuation of this outlawed practice remains poorly understood. No research has ever been conducted in Australia looking at the perception that young, migrant males have on FGM. Several European-based studies have examined the perceptions of older, poorly educated, migrant male cohorts. Generally, these studies show that the attitudinal support for FGM and intention to practice remains relatively high amongst these cohorts. This study examined the attitudes of a young, Sub-Saharan African, migrant, male cohort residing in Australia. This adds to the literature base by establishing the perceptions and associated socio-demographic variables of this unique and influential subset of the migrant population. This directly facilitates the development of interventional strategies against FGM by highlighting those most likely to have an attitudinal support in favour of FGM. Consequentially, this 'at risk' group can be more effectively focussed on interventional programmes and be further investigated in larger scale studies.

Non-invasive assessment of adrenocortical activity as a measure of stress in giraffe (Giraffa camelopardalis).

PubMed

Bashaw, Meredith J; Sicks, Florian; Palme, Rupert; Schwarzenberger, Franz; Tordiffe, Adrian S W; Ganswindt, Andre

2016-10-18

Numbers of giraffes are declining rapidly in their native habitat. As giraffe research and conservation efforts increase, the demand for more complete measures of the impact of conservation interventions and the effects of captive environments on animal health and welfare have risen. We compared the ability of six different enzyme immunoassays to quantify changes in fecal glucocorticoid metabolites (FGM) resulting from three sources: adrenocorticotropic hormone stimulation test, transport, and time of day that samples were collected. Two male giraffes underwent ACTH injections; all six assays detected FGM increases following injection for Giraffe 1, while only three assays detected FGM increases following injection for Giraffe 2. Consistent with other ruminant species, the two 11-oxoetiocholanolone assays (one for 11,17-dioxoandrostanes and the other for 3α,11-oxo metabolites) measured the most pronounced and prolonged elevation of FGM, while an assay for 3β,11β-diol detected peaks of smaller magnitude and duration. Both of the 11-oxoetiocholanolone assays detected significant FGM increases after transport in Giraffes 3-7, and preliminary data suggest FGM detected by the assay for 11,17-dioxoandrostanes may differ across time of day. We conclude the assay for 11,17-dioxoandrostanes is the most sensitive assay tested for FGM in giraffes and the assay for FGM with a 5β-3α-ol-11-one structure is also effective. 11-oxoetiocholanolone enzyme immunoassays have now been demonstrated to be successful in a wide variety of ruminant species, providing indirect evidence that 5β-reduction may be a common metabolic pathway for glucocorticoids in ruminants. As FGM peaks were detected in at least some giraffes using all assays tested, giraffes appear to excrete a wide variety of different FGM. The assays validated here will provide a valuable tool for research on the health, welfare, and conservation of giraffes.

Real-Time Intracellular Measurements of ROS and RNS in Living Cells with Single Core-Shell Nanowire Electrodes.

PubMed

Zhang, Xin-Wei; Qiu, Quan-Fa; Jiang, Hong; Zhang, Fu-Li; Liu, Yan-Lin; Amatore, Christian; Huang, Wei-Hua

2017-10-09

Nanoelectrodes allow precise and quantitative measurements of important biological processes at the single living-cell level in real time. Cylindrical nanowire electrodes (NWEs) required for intracellular measurements create a great challenge for achieving excellent electrochemical and mechanical performances. Herein, we present a facile and robust solution to this problem based on a unique SiC-core-shell design to produce cylindrical NWEs with superior mechanical toughness provided by the SiC nano-core and an excellent electrochemical performance provided by the ultrathin carbon shell that can be used as such or platinized. The use of such NWEs for biological applications is illustrated by the first quantitative measurements of ROS/RNS in individual phagolysosomes of living macrophages. As the shell material can be varied to meet any specific detection purpose, this work opens up new opportunities to monitor quantitatively biological functions occurring inside cells and their organelles. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Vibrations and structureborne noise in space station

NASA Technical Reports Server (NTRS)

Vaicaitis, R.; Lyrintzis, C. S.; Bofilios, D. A.

1987-01-01

Analytical models were developed to predict vibrations and structureborne noise generation of cylindrical and rectangular acoustic enclosures. These models are then used to determine structural vibration levels and interior noise to random point input forces. The guidelines developed could provide preliminary information on acoustical and vibrational environments in space station habitability modules under orbital operations. The structural models include single wall monocoque shell, double wall shell, stiffened orthotropic shell, descretely stiffened flat panels, and a coupled system composed of a cantilever beam structure and a stiffened sidewall. Aluminum and fiber reinforced composite materials are considered for single and double wall shells. The end caps of the cylindrical enclosures are modeled either as single or double wall circular plates. Sound generation in the interior space is calculated by coupling the structural vibrations to the acoustic field in the enclosure. Modal methods and transfer matrix techniques are used to obtain structural vibrations. Parametric studies are performed to determine the sensitivity of interior noise environment to changes in input, geometric and structural conditions.

Bending Boundary Layers in Laminated-Composite Circular Cylindrical Shells

NASA Technical Reports Server (NTRS)

Nemeth, Michael P.; Smeltzer, Stanley S., III

2000-01-01

An analytical, parametric study of the attenuation of bending boundary layers or edge effects in balanced and unbalanced, symmetrically and unsymmetrically laminated thin cylindrical shells is presented for nine contemporary material systems. The analysis is based on the linear Sanders-Koiter shell equations and specializations to the Love-Kirchhoff shell equations and Donnell's equations are included. Two nondimensional parameters are identified that characterize and quantify the effects of laminate orthotropy and laminate anisotropy on the bending boundary-layer decay length in a very general and encompassing manner. A substantial number of structural design technology results are presented for a wide range of laminated-composite cylinders. For all the laminate constructions considered, the results show that the differences between results that were obtained with the Sanders-Koiter shell equations, the Love-Kirchhoff shell equations, and Donnell's equations are negligible. The results also show that the effect of anisotropy in the form of coupling between pure bending and twisting has a negligible effect on the size of the bending boundary-layer decay length of the balanced, symmetrically laminated cylinders considered. Moreover, the results show that coupling between the various types of shell anisotropies has a negligible effect on the calculation of the bending boundary-layer decay length in most cases. The results also show that in some cases neglecting the shell anisotropy results in underestimating the bending boundary-layer decay length and in other cases it results in an overestimation.

Stop female genital mutilation: appeal to the international dermatologic community.

PubMed

Morrone, Aldo; Hercogova, Jana; Lotti, Torello

2002-05-01

Female genital mutilation (FGM) is a traditional cultural practice, but also a form of violence against girls, which affects their lives as adult women. FGM comprises a wide range of procedures: the excision of the prepuce; the partial or total excision of the clitoris (clitoridectomy) and labia; or the stitching and narrowing of the vaginal orifice (infibulation). The number of girls and women who have been subjected to FGM is estimated at around 137 million worldwide and 2 million girls per year are considered at risk. Most females who have undergone mutilation live in 28 African countries. Globalization and international migration have brought an increased presence of circumcised women in Europe and developed countries. Healthcare specialists need to be made aware and trained in the physical, psychosexual, and cultural aspects and effects of FGM and in the response to the needs of genitally mutilated women. Health education programs targeted at immigrant communities should include information on sexuality, FGM, and reproduction. Moreover, healthcare workers should both discourage women from performing FGM on their daughters and receive information on codes of conduct and existing laws. The aim is the total eradication of all forms of FGM.

Surgical reconstruction in female genital mutilation

PubMed Central

Gültekin, İsmail Burak; Altınboğa, Orhan; Dur, Rıza; Kara, Osman Fadıl; Küçüközkan, Tuncay

2016-01-01

Female genital mutilation (FGM) is an unusual condition for our country. However, an increase in FGM in future days can be predicted with the increasing numbers of exchange students coming from African countries, migration of refugees and socioeconomic relations with the African countries. We want to share our experience of two FGM victims admitted to our clinic with the request of reconstructive vulvar surgery before their marriage. Both women had WHO Type III FGM. Physical examination findings and surgical reconstruction techniques were presented. PMID:27274899

Explosion-Induced Implosions of Cylindrical Shell Structures

NASA Astrophysics Data System (ADS)

Ikeda, C. M.; Duncan, J. H.

2010-11-01

An experimental study of the explosion-induced implosion of cylindrical shell structures in a high-pressure water environment was performed. The shell structures are filled with air at atmospheric pressure and are placed in a large water-filled pressure vessel. The vessel is then pressurized to various levels P∞=αPc, where Pc is the natural implosion pressure of the model and α is a factor that ranges from 0.1 to 0.9. An explosive is then set off at various standoff distances, d, from the model center line, where d varies from R to 10R and R is the maximum radius of the explosion bubble. High-speed photography (27,000 fps) was used to observe the explosion and resulting shell structure implosion. High-frequency underwater blast sensors recorded dynamic pressure waves at 6 positions. The cylindrical models were made from aluminum (diameter D = 39.1 mm, wall thickness t = 0.89 mm, length L = 240 mm) and brass (D = 16.7 mm, t = 0.36 mm, L=152 mm) tubes. The pressure records are interpreted in light of the high-speed movies. It is found that the implosion is induced by two mechanisms: the shockwave generated by the explosion and the jet formed during the explosion-bubble collapse. Whether an implosion is caused by the shockwave or the jet depends on the maximum bubble diameter and the standoff distance.

Electroelastic fields in a layered piezoelectric cylindrical shell under dynamic load

NASA Astrophysics Data System (ADS)

Saviz, M. R.; Shakeri, M.; Yas, M. H.

2007-10-01

The objective of this paper is to demonstrate layerwise theory for the analysis of thick laminated piezoelectric shell structures. A general finite element formulation using the layerwise theory is developed for a laminated cylindrical shell with piezoelectric layers, subjected to dynamic loads. The quadratic approximation of the displacement and electric potential in the thickness direction is considered. The governing equations are reduced to two-dimensional (2D) differential equations. The three-dimensional (3D) elasticity solution is also presented. The resulting equations are solved by a proper finite element method. The numerical results for static loading are compared with exact solutions of benchmark problems. Numerical examples of the dynamic problem are presented. The convergence is studied, as is the influence of the electromechanical coupling on the axisymmetric free-vibration characteristics of a thick cylinder.

Transverse shear effects on the stress-intensity factor for a circumferentially cracked, specially orthotropic cylindrical shell

NASA Technical Reports Server (NTRS)

Delale, F.; Erdogan, F.

1977-01-01

The problem of a cylindrical shell containing a circumferential through crack is considered by taking into account the effect of transverse shear deformations. The formulation is given for a specially orthotropic material within the confines of a linearized shallow shell theory. The particular theory used permits the consideration of all five boundary conditions regarding moment and stress resultants on the crack surface. Consequently, aside from multiplicative constants representing the stress intensity factors, the membrane and bending components of the asymptotic stress fields near the crack tip are found to be identical. The stress intensity factors are calculated separately for a cylinder under a uniform membrane load, and that under a uniform bending moment. Sample results showing the nature of the out-of-plane crack surface displacement and the effect of the Poisson's ratio are presented.

Effects of female genital mutilation/cutting on the sexual function of Sudanese women: a cross-sectional study.

PubMed

Rouzi, Abdulrahim A; Berg, Rigmor C; Sahly, Nora; Alkafy, Susan; Alzaban, Faten; Abduljabbar, Hassan

2017-07-01

Female genital mutilation/cutting (FGM/C) is a cultural practice that involves several types of removal or other injury to the external female genitalia for nonmedical reasons. Although much international research has focused on the health consequences of the practice, little is known about sexual functioning among women with various types of FGM/C. To assess the impact of FGM/C on the sexual functioning of Sudanese women. This is a cross-sectional study conducted at Doctor Erfan and Bagedo Hospital, Jeddah, Saudi Arabia. Eligible women completed a survey and a clinical examination, which documented and verified women's type of FGM/C. The main outcome measure was female sexual function, as assessed by the Arabic Female Sexual Function Index. A total of 107 eligible women completed the survey and the gynecological examination, which revealed that 39% of the women had FGM/C Type I, 25% had Type II, and 36% had Type III. Reliability of self-report of the type of FGM/C was low, with underreporting of the extent of the procedure. The results showed that 92.5% of the women scored lower than the Arabic Female Sexual Function Index cut-off point for sexual dysfunction. The multivariable regression analyses showed that sexual dysfunction was significantly greater with more extensive type of FGM/C, across all sexual function domains (desire, arousal, lubrication, orgasm, satisfaction, and pain) and overall. The study documents that a substantial proportion of women subjected to FGM/C experience sexual dysfunction. It shows that the anatomical extent of FGM/C is related to the severity of sexual dysfunction. Copyright © 2017 Elsevier Inc. All rights reserved.

Implosion dynamics of a megampere wire-array Z-pinch with an inner low-density foam shell at the Angara-5-1 facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aleksandrov, V. V.; Bolkhovitinov, E. A.; Volkov, G. S., E-mail: volkov@triniti.ru

The implosion dynamics of a pinch with a highly inhomogeneous initial axial distribution of the load mass was studied experimentally. A cascade array consisting of a double nested tungsten wire array and a coaxial inner cylindrical shell located symmetrically with respect to the high-voltage electrodes was used as a load of the Angara-5-1 high-current generator. The cylindrical foam shell was half as long as the cathode− anode gap, and its diameter was equal to the diameter of the inner wire array. It is shown experimentally that two stages are typical of the implosion dynamics of such a load: the formationmore » of two separate pinches formed as a result of implosion of the wire array near the cathode and anode and the subsequent implosion of the central part of the load containing the cylindrical foam shell. The conditions are determined at which the implosion of the central part of the pinch with the foam cylinder is preceded by intense irradiation of the foam with the soft X-ray (SXR) emission generated by the near-electrode pinches and converting it into the plasma state. Using such a load, which models the main elements of the scheme of a dynamic hohlraum for inertial confinement fusion, it is possible to increase the efficiency of interaction between the outer accelerated plasma sheath and the inner foam shell by preionizing the foam with the SXR emission of the near-electrode pinches.« less

Type I female genital mutilation: a cause of completely closed vagina.

PubMed

Rouzi, Abdulrahim A; Sahly, Nora; Alhachim, Estabraq; Abduljabbar, Hassan

2014-09-01

Female genital mutilation (FGM) ranges in severity from a nick of the clitoris to partial or total removal of the external genitalia. Sexual complications after FGM include sexual dysfunction, difficult intercourse, and dyspareunia. We report a case of Type I FGM presenting as complete vaginal closure and urinary retention. A 16-year-old adolescent was referred for obliterated vagina and urinary retention. She had recurrent urinary tract infections, difficulty in voiding, and cyclic hematuria. At the age of 1 year she had been taken by her mother to a pediatric surgeon to have a Type I FGM procedure. On examination, the urethral meatus and vaginal orifices were completely closed by the FGM scar. She underwent uneventful surgical opening of the vagina. A normal vaginal orifice was created and normal flow of urine and menses occurred. Type I FGM can present as complete vaginal closure and urinary retention. Proper diagnosis and treatment are of paramount importance. © 2014 International Society for Sexual Medicine.

Aeroelastic analysis of circular cylindrical and truncated conical shells subjected to a supersonic flow

NASA Astrophysics Data System (ADS)

Sabri, Farhad

Shells of revolution, particularly cylindrical and conical shells, are one of the basic structural elements in the aerospace structures. With the advent of high speed aircrafts, these shells can show dynamic instabilities when they are exposed to a supersonic flow. Therefore, aeroelastic analysis of these elements is one of the primary design criteria which aeronautical engineers are dealing with. This analysis can be done with the help of finite element method (FEM) coupled with the computational fluid dynamic (CFD) or by experimental methods but it is time consuming and very expensive. The purpose of this dissertation is to develop such a numerical tool to do aeroelastic analysis in a fast and precise way. Meanwhile during the design stage, where the different configurations, loading and boundary conditions may need to be analyzed, this numerical method can be used very easily with the high order of reliability. In this study structural modeling is a combination of linear Sanders thin shell theory and classical finite element method. Based on this hybrid finite element method, the shell displacements are found from the exact solutions of shell theory rather than approximating by polynomial function done in traditional finite element method. This leads to a precise and fast convergence. Supersonic aerodynamic modeling is done based on the piston theory and modified piston theory with the shell curvature term. The stress stiffening due to lateral pressure and axial compression are also taken into accounts. Fluid-structure interaction in the presence of inside quiescent fluid is modeled based on the potential theory. In this method, fluid is considered as a velocity potential variable at each node of the shell element where its motion is expressed in terms of nodal elastic displacements at the fluid-structure interface. This proposed hybrid finite element has capabilities to do following analysis: (i) Buckling and vibration of an empty or partially fluid filled circular cylindrical shell or truncated conical shell subjected to internal/external pressure and axial compression loading. This is a typical example of external liquid propellant tanks of space shuttles and re-entry vehicles where they may experience this kind of loading during the flight. In the current work, different end boundary conditions of a circular cylindrical shell with different filling ratios were analyzed. To the best author' knowledge this is the first study where this kind of complex loading and boundary conditions are treated together during such an analysis. Only static instability, divergence, was observed where it showed that the fluid filling ratio does not have any effect on the critical buckling pressure and axial compression. It only reduces the vibration frequencies. It also revealed that the pressurized shell loses its stability at a higher critical axial load. (ii) Aeroelastic analysis of empty or partially liquid filled circular cylindrical and conical shells. Different boundary conditions with different geometries of shells subjected to supersonic air flow are studied here. In all of cases shell loses its stability though the coupled mode flutter. The results showed that internal pressure has a stabilizing effect and increases the critical flutter speed. It is seen that the value of critical dynamic pressure changes rapidly and widely as the filling ratio increases from a low value. In addition, by increasing the length ratio the decrement of flutter speed is decreased and vanishes. This rapid change in critical dynamic pressure at low filling ratios and its almost steady behaviour at large filling ratios indicate that the fluid near the bottom of the shell is largely influenced by elastic deformation when a shell is subjected to external subsonic flow. Based on comparison with the existing numerical, analytical and experimental data and the power of capabilities of this hybrid finite element method to model different boundary conditions and complex loadings, this FEM package can be used effectively for the design of advanced aerospace structures. It provides the results at less computational cost compare to the commercial FEM software, which imposes some restrictions when such an analysis is done.

Broadband Monopole Antenna

DTIC Science & Technology

2017-09-14

surrounded by a series of shells 14, 16 and 18 of anisotropic dielectric material. In this embodiment, each of the shells 14, 16, or 18 is cylindrical in...static polarizability of approximately 10 Attorney Docket No. 300161 7 of 13 times that of free space, satisfying the definition of an anisotropic

Route towards cylindrical cloaking at visible frequencies using an optimization algorithm

NASA Astrophysics Data System (ADS)

Rottler, Andreas; Krüger, Benjamin; Heitmann, Detlef; Pfannkuche, Daniela; Mendach, Stefan

2012-12-01

We derive a model based on the Maxwell-Garnett effective-medium theory that describes a cylindrical cloaking shell composed of metal rods which are radially aligned in a dielectric host medium. We propose and demonstrate a minimization algorithm that calculates for given material parameters the optimal geometrical parameters of the cloaking shell such that its effective optical parameters fit the best to the required permittivity distribution for cylindrical cloaking. By means of sophisticated full-wave simulations we find that a cylindrical cloak with good performance using silver as the metal can be designed with our algorithm for wavelengths in the red part of the visible spectrum (623nm <λ<773nm). We also present a full-wave simulation of such a cloak at an exemplary wavelength of λ=729nm (ℏω=1.7eV) which indicates that our model is useful to find design rules of cloaks with good cloaking performance. Our calculations investigate a structure that is easy to fabricate using standard preparation techniques and therefore pave the way to a realization of guiding light around an object at visible frequencies, thus rendering it invisible.

Non-invasive monitoring of glucocorticoid metabolites in banded mongooses (Mungos mungo) in response to physiological and biological challenges.

PubMed

Laver, Peter N; Ganswindt, André; Ganswindt, Stefanie B; Alexander, Kathleen A

2012-11-01

Free-ranging banded mongooses are infected by the novel pathogen, Mycobacterium mungi in northern Botswana. A reliable method for determining stress-related physiological responses in banded mongooses will increase our understanding of the stress response in M. mungi infection. Therefore, our aim was to examine the suitability of four enzyme immunoassays (EIAs) for monitoring adrenocortical endocrine function in captive and free-ranging banded mongooses based on fecal glucocorticoid metabolite (FGM) analysis. A conducted adrenocorticotropic hormone challenge revealed suitability of a valid measurement of FGM levels in banded mongoose feces for all four tested EIAs, with an 11-oxoetiocholanolone assay detecting 11,17-dioxoandrostanes (11,17-DOA) performing best. Subsequent analyses using only this EIA showed the expected decrease in FGM concentrations 48 h after administering dexamethasone sodium phosphate. Furthermore, captive mongooses showed higher FGM concentrations during reproductive activity, agonistic encounters and depredation events. Finally, a late-stage, tuberculosis-infected moribund mongoose in a free-ranging troop had a 54-fold elevation in FGM levels relative to the rest of the troop. Measurements of gastrointestinal transit times and FGM metabolism post-defecation indicate that the time delay of FGM excretion approximately corresponded with food transit time and that FGM metabolism is minimal up to 8h post-defecation. The ability to reliably assess adrenocortical endocrine function in banded mongoose now provides a solid basis for advancing our understanding of infectious disease and endocrinology in this species. Copyright © 2012 Elsevier Inc. All rights reserved.

Deinfibulation for preventing or treating complications in women living with type III female genital mutilation: A systematic review and meta-analysis.

PubMed

Okusanya, Babasola O; Oduwole, Olabisi; Nwachuku, Nuria; Meremikwu, Martin M

2017-02-01

Deinfibulation is a surgical procedure carried out to re-open the vaginal introitus of women living with type III female genital mutilation (FGM). To assess the impact of deinfibulation on gynecologic or obstetric outcomes by comparing women who were deinfibulated with women with type III FGM or women without FGM. Major databases including CENTRAL, MEDLINE, and Scopus were searched until August 2015. We included nonrandomized studies that compared obstetric outcomes of women with deinfibulation, type III FGM (not deinfibulated during labor), and no FGM. Quality of evidence was determined following the GRADE methodology. Summary measures were calculated using odds ratios at 95% confidence intervals. We found no randomized controlled trials. We included four case-control studies. The quality of evidence was very low. Compared with women with type III FGM at delivery, deinfibulated women had a significant reduction in the risk of having a cesarean delivery or postpartum hemorrhage. Compared with women without FGM, deinfibulated women had a similar risk of episiotomy, cesarean delivery, vaginal lacerations, postpartum hemorrhage, and blood loss at vaginal delivery. The length of second stage of labor, mean maternal hospital stay, and Apgar scores less than 7 were also comparable. Low-quality evidence suggests deinfibulation improves birth outcomes for women with type III FGM. CRD42015024466. © 2017 International Federation of Gynecology and Obstetrics. The World Health Organization retains copyright and all other rights in the manuscript of this article as submitted for publication.

Load Tests on a Stiffened Circular Cylindrical Shell

NASA Technical Reports Server (NTRS)

Schapitz, E; Krumling, G

1938-01-01

The present report describes tests in which the stress distribution may be determined in a stiffened circular cylindrical shell loaded longitudinally at four symmetrically situated points. As being of particular importance are the cases investigated of groups of bending and arching or convexing forces, respectively. From the stress measurements on the longitudinal stiffeners, the shear stresses and the bulkhead ring stresses in the skin could be evaluated. These measurements showed that the "simple shear field" used in theoretical computations in which all normal stresses in the skin are neglected, must be extended by the addition of the transverse or circumferential stresses if the bulkhead rings are not riveted to the skin.

Evaluation of radiation loading on finite cylindrical shells using the fast Fourier transform: A comparison with direct numerical integration.

PubMed

Liu, S X; Zou, M S

2018-03-01

The radiation loading on a vibratory finite cylindrical shell is conventionally evaluated through the direct numerical integration (DNI) method. An alternative strategy via the fast Fourier transform algorithm is put forward in this work based on the general expression of radiation impedance. To check the feasibility and efficiency of the proposed method, a comparison with DNI is presented through numerical cases. The results obtained using the present method agree well with those calculated by DNI. More importantly, the proposed calculating strategy can significantly save the time cost compared with the conventional approach of straightforward numerical integration.

Feasibility and Practical Limits for the Use of Lightweight Prestressed Concrete (LWPC) as a Shipbuilding Material.

DTIC Science & Technology

1982-10-01

centerline by stanchions. A concrete beam is provided at the ship centerline to transfer unbalanced stanchion loads longitudinally along the shell . The 01...Place Cast-in-Place Concrete Connections -- Connections betw. an precast shell elements are made using cast-in-place concrete closure pours. See Figure...buckling using the column provi sions of the ACI code. For shells , the critical radius to thickness ratio is about 200 for cylindrical shells loaded in

For the sake of purity (and control). Female genital mutilation.

PubMed

Gilbert, D

1993-01-01

In 1973 approximately 1 million girls will be victimized by female genital mutilation (FGM), widely practiced in more than 20 African nations from Mauritania to the Ivory Coast in the west, to Egypt and North Tanzania in the east, as well as in Oman, Bahrain, North and South Yemen, and the United Arab Emirates. FGM takes place among the Moslem populations of the Philippines, Indonesia, and Malaysia and the Jewish Falashas in Ethiopia. FGM is practiced on babies just a few days old to girls right before marriage or young women pregnant with their first child. The most extreme mutilation is called infibulation. In Somalia, almost 100% of the women are infibulated, and so are more than 80% of the women in north and central Sudan. In Ethiopia/Eritrea, Mali, and Sierra Leone, 90% of the women have undergone some form of genital mutilation. The rate reaches 70% in Burkina Faso; 60% in Kenya, Gambia, and the Ivory Coast; and 50% in Senegal, Egypt, Guinea Bissau, and Nigeria. The mutilation often results in accumulation of menstrual blood and pelvic inflammatory disease often leading to infertility. Between 20% and 25% of infertility in Sudan has been attributed to female genital mutilation. The practice of FGM has existed for centuries, and some claim it originated in the Nile Valley during the Pharaonic era. On the other hand, Muslim countries like Iraq, Syria, and Tunisia do not practice FGM. The London Black Women's Health Action Project set up an educational network to prevent mutilations and to dispel the myth of religion about FGM. FORWARD convened the First Study Conference on Genital Mutilation of Girls in Europe in 1992 and deemed FGM a form of child abuse. Local campaigns in Africa, Asia, and the Arab world educate against FGM. The Inter-Africa Committee on Traditional Practices Affecting the Health of Women and Children, based in Addis Ababa, Ethiopia, has offices in more than 20 African nations to sensitize the public about the harmful effects of FGM. In Nigeria, the National Association of Nigerian Nurses and Midwives presents plays in the local markets about the complications of FGM.

Health sector involvement in the management of female genital mutilation/cutting in 30 countries.

PubMed

Johansen, R Elise B; Ziyada, Mai Mahgoub; Shell-Duncan, Bettina; Kaplan, Adriana Marcusàn; Leye, Els

2018-04-04

For the last decades, the international community has emphasised the importance of a multisectoral approach to tackle female genital mutilation (FGM/C). While considerable improvement concerning legislations and community involvement is reported, little is known about the involvement of the health sector. A mixed methods approach was employed to map the involvement of the health sector in the management of FGM/C both in countries where FGM/C is a traditional practice (countries of origin), and countries where FGM/C is practiced mainly by migrant populations (countries of migration). Data was collected in 2016 using a pilot-tested questionnaire from 30 countries (11 countries of origin and 19 countries of migration). In 2017, interviews were conducted to check for data accuracy and to request relevant explanations. Qualitative data was used to elucidate the quantitative data. A total of 24 countries had a policy on FGM/C, of which 19 had assigned coordination bodies and 20 had partially or fully implemented the plans. Nevertheless, allocation of funding and incorporation of monitoring and evaluation systems was lacking in 11 and 13 of these countries respectively. The level of the health sectors' involvement varied considerably across and within countries. Systematic training of healthcare providers (HCP) was more prevalent in countries of origin, whereas involvement of HCP in the prevention of FGM/C was more prevalent in countries of migration. Most countries reported to forbid HCP from conducting FGM/C on both minors and adults, but not consistently forbidding re-infibulation. Availability of healthcare services for girls and women with FGM/C related complications also varied between countries dependent on the type of services. Deinfibulation was available in almost all countries, while clitoral reconstruction and psychological and sexual counselling were available predominantly in countries of migration and then in less than half the countries. Finally, systematic recording of FGM/C in medical records was completely lacking in countries of origin and very limited in countries of migration. Substantial progress has been made in the involvement of the health sector in both the treatment and prevention of FGM/C. Still, there are several areas in need for improvement, particularly monitoring and evaluation.

Application of the line-spring model to a cylindrical shell containing a circumferential or axial part-through crack

NASA Technical Reports Server (NTRS)

Delale, F.; Erdogan, F.

1981-01-01

An approximate solution was obtained for a cylindrical shell containing a part-through surface crack. It was assumed that the shell contains a circumferential or axial semi-elliptic internal or external surface crack and was subjected to a uniform membrane loading or a uniform bending moment away from the crack region. A Reissner type theory was used to account for the effects of the transverse shear deformations. The stress intensity factor at the deepest penetration point of the crack was tabulated for bending and membrane loading by varying three dimensionless length parameters of the problem formed from the shell radius, the shell thickness, the crack length, and the crack depth. The upper bounds of the stress intensity factors are provided by the results of the elasticity solution obtained from the axisymmetric crack problem for the circumferential crack, and that found from the plane strain problem for a circular ring having a radial crack for the axial crack. The line-spring model gives the expected results in comparison with the elasticity solutions. Results also compare well with the existing finite element solution of the pressurized cylinder containing an internal semi-elliptic surface crack.

Bell-Plesset effects in Rayleigh-Taylor instability of finite-thickness spherical and cylindrical shells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Velikovich, A. L.; Schmit, P. F.

Bell-Plesset (BP) effects account for the influence of global convergence or divergence of the fluid flow on the evolution of the interfacial perturbations embedded in the flow. The development of the Rayleigh-Taylor instability in radiation-driven spherical capsules and magnetically-driven cylindrical liners necessarily includes a significant contribution from BP effects due to the time dependence of the radius, velocity, and acceleration of the unstable surfaces or interfaces. An analytical model is presented that, for an ideal incompressible fluid and small perturbation amplitudes, exactly evaluates the BP effects in finite-thickness shells through acceleration and deceleration phases. The time-dependent dispersion equations determining themore » “instantaneous growth rate” are derived. It is demonstrated that by integrating this approximate growth rate over time, one can accurately evaluate the number of perturbation e-foldings during the inward acceleration phase of the implosion. In the limit of small shell thickness, exact thin-shell perturbation equations and approximate thin-shell dispersion equations are obtained, generalizing the earlier results [E. G. Harris, Phys. Fluids 5, 1057 (1962); E. Ott, Phys. Rev. Lett. 29, 1429 (1972); A. B. Bud'ko et al., Phys. Fluids B 2, 1159 (1990)].« less

Bell-Plesset effects in Rayleigh-Taylor instability of finite-thickness spherical and cylindrical shells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Velikovich, A. L.; Schmit, P. F.

Bell-Plesset (BP) effects account for the influence of global convergence or divergence of the fluid flow on the evolution of the interfacial perturbations embedded in the flow. The development of the Rayleigh-Taylor instability in radiation-driven spherical capsules and magnetically-driven cylindrical liners necessarily includes a significant contribution from BP effects due to the time dependence of the radius, velocity, and acceleration of the unstable surfaces or interfaces. An analytical model is presented that, for an ideal incompressible fluid and small perturbation amplitudes, exactly evaluates the BP effects in finite-thickness shells through acceleration and deceleration phases. The time-dependent dispersion equations determining themore » “instantaneous growth rate” are derived. It is demonstrated that by integrating this approximate growth rate over time, one can accurately evaluate the number of perturbation e-foldings during the inward acceleration phase of the implosion. As a result, in the limit of small shell thickness, exact thin-shell perturbationequations and approximate thin-shell dispersion equations are obtained, generalizing the earlier results [E. G. Harris, Phys. Fluids 5, 1057 (1962); E. Ott, Phys. Rev. Lett. 29, 1429 (1972); A. B. Bud'ko et al., Phys. Fluids B 2, 1159 (1990)].« less

Bell-Plesset effects in Rayleigh-Taylor instability of finite-thickness spherical and cylindrical shells

DOE PAGES

Velikovich, A. L.; Schmit, P. F.

2015-12-28

Bell-Plesset (BP) effects account for the influence of global convergence or divergence of the fluid flow on the evolution of the interfacial perturbations embedded in the flow. The development of the Rayleigh-Taylor instability in radiation-driven spherical capsules and magnetically-driven cylindrical liners necessarily includes a significant contribution from BP effects due to the time dependence of the radius, velocity, and acceleration of the unstable surfaces or interfaces. An analytical model is presented that, for an ideal incompressible fluid and small perturbation amplitudes, exactly evaluates the BP effects in finite-thickness shells through acceleration and deceleration phases. The time-dependent dispersion equations determining themore » “instantaneous growth rate” are derived. It is demonstrated that by integrating this approximate growth rate over time, one can accurately evaluate the number of perturbation e-foldings during the inward acceleration phase of the implosion. As a result, in the limit of small shell thickness, exact thin-shell perturbationequations and approximate thin-shell dispersion equations are obtained, generalizing the earlier results [E. G. Harris, Phys. Fluids 5, 1057 (1962); E. Ott, Phys. Rev. Lett. 29, 1429 (1972); A. B. Bud'ko et al., Phys. Fluids B 2, 1159 (1990)].« less

Bell-Plesset effects in Rayleigh-Taylor instability of finite-thickness spherical and cylindrical shells

NASA Astrophysics Data System (ADS)

Velikovich, A. L.; Schmit, P. F.

2015-12-01

Bell-Plesset (BP) effects account for the influence of global convergence or divergence of the fluid flow on the evolution of the interfacial perturbations embedded in the flow. The development of the Rayleigh-Taylor instability in radiation-driven spherical capsules and magnetically-driven cylindrical liners necessarily includes a significant contribution from BP effects due to the time dependence of the radius, velocity, and acceleration of the unstable surfaces or interfaces. An analytical model is presented that, for an ideal incompressible fluid and small perturbation amplitudes, exactly evaluates the BP effects in finite-thickness shells through acceleration and deceleration phases. The time-dependent dispersion equations determining the "instantaneous growth rate" are derived. It is demonstrated that by integrating this approximate growth rate over time, one can accurately evaluate the number of perturbation e-foldings during the inward acceleration phase of the implosion. In the limit of small shell thickness, exact thin-shell perturbation equations and approximate thin-shell dispersion equations are obtained, generalizing the earlier results [E. G. Harris, Phys. Fluids 5, 1057 (1962); E. Ott, Phys. Rev. Lett. 29, 1429 (1972); A. B. Bud'ko et al., Phys. Fluids B 2, 1159 (1990)].

Experimental demonstration of invisible electromagnetic impedance matching cylindrical transformation optics cloak shell

NASA Astrophysics Data System (ADS)

Chen, Mingji; Wang, Changxian; Cheng, Xiaodong; Gong, Congcheng; Song, Weili; Yuan, Xujin; Fang, Daining

2018-04-01

The realization of an ideal invisible cloak implementing transformation optics is still missing. An impedance matching concept is implanted into transformation optics cloak to generate an impedance matching cloak (IMC) shell. In this work, it is proved that impedance matching structure reduces the cloaking structure’s disturbance to a propagating electromagnetic field and improves its invisibility measured by scattering field intensity. Such a cylindrical IMC shell is designed, fabricated with proposed rounded rectangular split-ring-resonators (RR-SRRs), and experimental measurements show the total scattering field of a perfect electric conductor (PEC) cylinder surrounded by an IMC shell is improved greatly compared to the PEC cylinder showing electromagnetic wave front ripple suppression and a considerable scattering shrinking effect. IMC shell backward scattering field is suppressed down to 7.29%, compared to the previous value of 86.7% due to its impedance matching character, and overall scattering field intensity shrinking is down to 19.3% compared to the previously realized value of 56.4%. Sideward scattering field recorded in the experiment also has a remarkable improvement compared to the PEC cylinder. The impedance matching concept might enlighten the realization of an ideal cloak and other novel electromagnetic cloaking and shielding structures.

Fully localized post-buckling states of cylindrical shells under axial compression

NASA Astrophysics Data System (ADS)

Kreilos, Tobias; Schneider, Tobias M.

2017-09-01

We compute nonlinear force equilibrium solutions for a clamped thin cylindrical shell under axial compression. The equilibrium solutions are dynamically unstable and located on the stability boundary of the unbuckled state. A fully localized single dimple deformation is identified as the edge state-the attractor for the dynamics restricted to the stability boundary. Under variation of the axial load, the single dimple undergoes homoclinic snaking in the azimuthal direction, creating states with multiple dimples arranged around the central circumference. Once the circumference is completely filled with a ring of dimples, snaking in the axial direction leads to further growth of the dimple pattern. These fully nonlinear solutions embedded in the stability boundary of the unbuckled state constitute critical shape deformations. The solutions may thus be a step towards explaining when the buckling and subsequent collapse of an axially loaded cylinder shell is triggered.

Analysis, Design and Optimization of Non-Cylindrical Fuselage for Blended-Wing-Body (BWB) Vehicle

NASA Technical Reports Server (NTRS)

Mukhopadhyay, V.; Sobieszczanski-Sobieski, J.; Kosaka, I.; Quinn, G.; Charpentier, C.

2002-01-01

Initial results of an investigation towards finding an efficient non-cylindrical fuselage configuration for a conceptual blended-wing-body flight vehicle were presented. A simplified 2-D beam column analysis and optimization was performed first. Then a set of detailed finite element models of deep sandwich panel and ribbed shell construction concepts were analyzed and optimized. Generally these concepts with flat surfaces were found to be structurally inefficient to withstand internal pressure and resultant compressive loads simultaneously. Alternatively, a set of multi-bubble fuselage configuration concepts were developed for balancing internal cabin pressure load efficiently, through membrane stress in inner-stiffened shell and inter-cabin walls. An outer-ribbed shell was designed to prevent buckling due to external resultant compressive loads. Initial results from finite element analysis appear to be promising. These concepts should be developed further to exploit their inherent structurally efficiency.

On sound transmission through double-walled cylindrical shells lined with poroelastic material: Comparison with Zhou's results and further effect of external mean flow

NASA Astrophysics Data System (ADS)

Liu, Yu; He, Chuanbo

2015-12-01

In this discussion, the corrections to the errors found in the derivations and the numerical code of a recent analytical study (Zhou et al. Journal of Sound and Vibration 333 (7) (2014) 1972-1990) on sound transmission through double-walled cylindrical shells lined with poroelastic material are presented and discussed, as well as the further effect of the external mean flow on the transmission loss. After applying the corrections, the locations of the characteristic frequencies of thin shells remain unchanged, as well as the TL results above the ring frequency where BU and UU remain the best configurations in sound insulation performance. In the low-frequency region below the ring frequency, however, the corrections attenuate the TL amplitude significantly for BU and UU, and hence the BB configuration exhibits the best performance which is consistent with previous observations for flat sandwich panels.

Acoustically excited surface waves on empty or fluid-filled cylindrical and spherical shells

NASA Astrophysics Data System (ADS)

Ahyi, A. Claude; Cao, H.; Raju, P. K.; Werby, M. F.; Bao, X. L.; Überall, H.

2002-05-01

A comparative study is presented of the acoustical excitation of circumferential (surface) waves on fluid-immersed cylindrical or spherical metal shells, which may be either evacuated, or filled with the same or a different fluid. The excited surface waves can manifest themselves by the resonances apparent in the sound scattering amplitude, which they cause upon phase matching following repeated circumnavigations of the target object, or by their re-radiation into the external fluid in the manner of head waves. We plot dispersion curves versus frequency of the surface waves, which for evacuated shells have a generally rising character, while the fluid filling adds an additional set of circumferential waves that descend with frequency. The resonances of these latter waves may also be interpreted as being due to phase matching, but they may alternately be interpreted as constituting the eigenfrequencies of the internal fluid contained in an elastic enclosure.

Acoustic scattering from a finite cylindrical shell with evenly spaced stiffeners: Experimental investigation

NASA Astrophysics Data System (ADS)

Liétard, R.; Décultot, D.; Maze, G.; Tran-van-Nhieu, M.

2005-10-01

The influence of evenly spaced ribs (internal rings) on the acoustic scattering from a finite cylindrical shell is examined over the dimensionless frequency range 1

Methodology for Selection of Optimum Light Stringers in Functionally Graded Panels Designed for Prescribed Fundamental Frequency or Buckling Load

NASA Astrophysics Data System (ADS)

Birman, Victor; Byrd, Larry W.

2008-02-01

The interest to functionally graded materials (FGM) and structures has been generated by their potential advantages, including enhanced thermal properties, reduced or eliminated delamination concerns, a potential for an improved stress distribution, etc. Various aspects of the processing, design, micromechanics and analysis of FGM have been outlined in a number of reviews, mentioned here are [1-3]. In particular, functionally graded panels may be advantageous compared to their conventional counterparts in numerous applications. However, a typical FGM panel is asymmetric about its middle plane resulting in lower buckling loads and fundamental frequencies as well as higher stresses and deformations than the counterpart with a symmetric distribution of the same constituents. The reduced stiffness of FGM panels can be compensated by reinforcing them with stringers. For example, metallic stringers at the metal-rich surface of a FGM ceramic-metal panel may provide an efficient solution enabling a designer to increase both buckling loads as well as natural frequencies. The list of studies on optimization of FGM is extensive as could be anticipated for such tailored structural elements. For example, recent papers by Batra and his collaborators present optimization of the natural frequencies of a FGM plate through material grading [4] and through the graded fiber orientation [5]. The present paper is concerned with an optimum design of the system of stringers for a specified FGM panel. The task is to design the lightest system of stringers enabling the panel to achieve prescribed buckling loads or fundamental frequency.

Management of female genital mutilation in Djibouti: the Peltier General hospital experience.

PubMed

Collinet, P; Stien, L; Vinatier, D; Leroy, J L

2002-11-01

Female genital mutilation (FGM) is still performed on 98% of Djiboutian women. Infibulation (FGM type 3) is the most widely used method of FGM in Djibouti. Even though this operation is mutilating, illegal and sometimes results in death, it is still practiced at approximately the same rate as in the past. Mass immigration of African women to Europe, Canada, Australia and the United States in the past decade has brought the problems of FGM to these countries. Female genital mutilation is a problem unfamiliar to most Western obstetrician-gynecologists. A tight infibulation can be a high risk for the mother and fetus if not handled by a skilled operator. It can lead to an unnecessary cesarean section as a result of the fear of handling infibulated women. Therefore, Western physicians need to be informed. The aim of this article was to share our experience of FGM. It will focus on FGM in Djibouti, its types, epidemiology and health consequences. It will present the management of obstetric and gynecologic complications and discuss medico-legal and health service measures to combat these dangerous and unnecessary practices

A novel method for characterizing the impact response of functionally graded plates

NASA Astrophysics Data System (ADS)

Larson, Reid A.

Functionally graded material (FGM) plates are advanced composites with properties that vary continuously through the thickness of the plate. Metal-ceramic FGM plates have been proposed for use in thermal protection systems where a metal-rich interior surface of the plate gradually transitions to a ceramic-rich exterior surface of the plate. The ability of FGMs to resist impact loads must be demonstrated before using them in high-temperature environments in service. This dissertation presents a novel technique by which the impact response of FGM plates is characterized for low-velocity, low- to medium-energy impact loads. An experiment was designed where strain histories in FGM plates were collected during impact events. These strain histories were used to validate a finite element simulation of the test. A parameter estimation technique was developed to estimate local material properties in the anisotropic, non-homogenous FGM plates to optimize the finite element simulations. The optimized simulations captured the physics of the impact events. The method allows research & design engineers to make informed decisions necessary to implement FGM plates in aerospace platforms.

Sexual Anatomy and Function in Women With and Without Genital Mutilation: A Cross-Sectional Study.

PubMed

Abdulcadir, Jasmine; Botsikas, Diomidis; Bolmont, Mylène; Bilancioni, Aline; Djema, Dahila Amal; Bianchi Demicheli, Francesco; Yaron, Michal; Petignat, Patrick

2016-02-01

Female genital mutilation (FGM), the partial or total removal of the external genitalia for non-medical reasons, can affect female sexuality. However, only few studies are available, and these have significant methodologic limitations. To understand the impact of FGM on the anatomy of the clitoris and bulbs using magnetic resonance imaging and on sexuality using psychometric instruments and to study whether differences in anatomy after FGM correlate with differences in sexual function, desire, and body image. A cross-sectional study on sexual function and sexual anatomy was performed in women with and without FGM. Fifteen women with FGM involving cutting of the clitoris and 15 uncut women as a control group matched by age and parity were prospectively recruited. Participants underwent pelvic magnetic resonance imaging with vaginal opacification by ultrasound gel and completed validated questionnaires on desire (Sexual Desire Inventory), body image (Questionnaire d'Image Corporelle [Body Image Satisfaction Scale]), and sexual function (Female Sexual Function Index). Primary outcomes were clitoral and bulbar measurements on magnetic resonance images. Secondary outcomes were sexual function, desire, and body image scores. Women with FGM did not have significantly decreased clitoral glans width and body length but did have significantly smaller volume of the clitoris plus bulbs. They scored significantly lower on sexual function and desire than women without FGM. They did not score lower on Female Sexual Function Index sub-scores for orgasm, desire, and satisfaction and on the Questionnaire d'Image Corporelle but did report significantly more dyspareunia. A larger total volume of clitoris and bulbs did not correlate with higher Female Sexual Function Index and Sexual Desire Inventory scores in women with FGM compared with uncut women who had larger total volume that correlated with higher scores. Women with FGM have sexual erectile tissues for sexual arousal, orgasm, and pleasure. Women with sexual dysfunction should be appropriately counseled and treated. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

Health complications of female genital mutilation in Sierra Leone

PubMed Central

Bjälkander, Owolabi; Bangura, Laurel; Leigh, Bailah; Berggren, Vanja; Bergström, Staffan; Almroth, Lars

2012-01-01

Sierra Leone has one of the highest rates of female genital mutilation (FGM) in the world, and yet little is known about the health consequences of the practice. Purpose To explore whether and what kind of FGM-related health complications girls and women in Sierra Leone experience, and to elucidate their health care-seeking behaviors. Patients and methods A feasibility study was conducted to test and refine questionnaires and methods used for this study. Thereafter, a cross-section of girls and women (n = 258) attending antenatal care and Well Women Clinics in Bo Town, Bo District, in the southern region and in Makeni Town, Bombali District, in the northern region of Sierra Leone were randomly selected. Participants answered interview-administrated pretested structured questionnaires with open- ended-questions, administrated by trained female personnel. Results All respondents had undergone FGM, most between 10 and 14 years of age. Complications were reported by 218 respondents (84.5%), the most common ones being excessive bleeding, delay in or incomplete healing, and tenderness. Fever was significantly more often reported by girls who had undergone FGM before 10 years of age compared with those who had undergone the procedure later. Out of those who reported complications, 187 (85.8%) sought treatment, with 89 of them visiting a traditional healer, 75 a Sowei (traditional circumciser), and 16 a health professional. Conclusion The high prevalence rate of FGM and the proportion of medical complications show that FGM is a matter for public health concern in Sierra Leone. Girls who undergo FGM before 10 years of age seem to be more vulnerable to serious complications than those who are older at the time of FGM. It is important that health care personnel are aware of, and look for possible complications from FGM, and encourage girls and women to seek medical care for their problems. PMID:22870046

Prevalence and predictors of female genital mutilation among infants in a semi urban community in northern Nigeria.

PubMed

Ashimi, Adewale O; Amole, Taiwo G; Iliyasu, Zubairu

2015-12-01

To determine the prevalence, predictors, of female genital mutilation (FGM) among infants and ascertain if their mothers knew what was done to them in Birnin Kudu northern Nigeria. Cross sectional study which utilised a pretested interviewer administered semi-structured questionnaire to assess occurrence of FGM with physical examination of the infants. Logistic regression analysis was used to assess the relative effect of determinants, after adjusting for other predictor variables. Of the 450 infants, 215(47.8%) (95% Confidence Interval [CI]: 43.1%-52.5%) had experienced one form of FGM. The ages at genital mutilation ranged from 1 to 50 days with a median of 4 days and interquartile range of 7 days. Maternal occupation, education and religion and type of facility accessed were significantly associated with occurrence of FGM in infants (p ≤ 0.05). After controlling for confounders, having a mother without formal education [AOR = 6.39 and 95% CI = 3.99-10.23] (p = 0.001) and one who was employed [Adjusted odds ratio (AOR) = 2.89 and 95% CI = 1.66-5.03] (p = 0.001) increased the likelihood of infant FGM remarkably while utilising tertiary institution for health care reduced the risk by about half [AOR = 0.49 and 95% CI = 0.26-0.92] (p = 0.03). Of the 215 infants that had undergone FGM, there was correlation between the reported and the observed forms of FGM in 16 (7.4%) of the cases. The prevalence of FGM is high with mothers' educational status, type of health facility utilised and occupational status being predictors of FGM among infants in Birnin Kudu. Majority of the mothers are not aware of what was done. Strategies aimed at discouraging this dangerous practice in the community should include female education, involvement of the men as husbands, fathers, traditional and religious leaders. Copyright © 2015 Elsevier B.V. All rights reserved.

Epidemiology, Regional Characteristics, Knowledge, and Attitude Toward Female Genital Mutilation/Cutting in Southern Iran.

PubMed

Dehghankhalili, Maryam; Fallahi, Soghra; Mahmudi, Forugh; Ghaffarpasand, Fariborz; Shahrzad, Mohammad Esmaeil; Taghavi, Mohsen; Fereydooni Asl, Marjan

2015-07-01

Female genital mutilation/cutting (FGM/C), also known as female circumcision, is an ancient traditional procedure that involves partial or total removal of the female external genitalia for nonmedical reasons. Although it is well described in African and some Arabic countries, data from Iran are scarce. To describe the epidemiology, regional characteristics, knowledge, and attitude toward FGM/C in Southern Iran. This cross-sectional study was conducted during a 36-month period from 2010 to 2013 in Hormozgan, a southern province of Iran near the Persian Gulf. We included 780 women in six major rural areas of the province who referred to healthcare centers for vaccination, midwifery, or family planning services. All participants underwent complete pelvic examination to determine the type of FGM. The questionnaire consisted of several sections such as demographic and baseline characteristics, and two self-report sections addressing the knowledge and attitude toward FGM/C and its complications. Baseline sociodemographic characteristics including age, educational level, marital status, religion, and nationality were the independent variables. Among the participants, 535 (68.5%) had undergone FGM/C. FGM/C was associated with higher age (P = 0.002), Afghan nationality (P = 0.003), Sunni Islam as religion (P = 0.019), illiteracy (P < 0.001), and family history of FGM/C in mother (P < 0.001), sister (P < 0.001), and grandmother (P < 0.001). Ancient traditions in the area (57.1%) were mentioned as the most important factor leading to FMG/C. Urinary tract infection was the most common reported complication (60.4%). FGM/C is a common practice in rural areas of Southern Iran. It is associated with increased age, illiteracy, Sunni Islam religion, Afghan nationality, and positive family history. Lack of knowledge toward FGM/C is the main cause of its high prevalence and continuation in the area. © 2015 International Society for Sexual Medicine.

Effect of female genital mutilation/cutting on sexual functions.

PubMed

Biglu, Mohammad-Hossein; Farnam, Alireza; Abotalebi, Parvaneh; Biglu, Sahar; Ghavami, Mostafa

2016-12-01

Female Genital Mutilation/Cutting (FGM/C) or female circumcision is the procedure of eliminating some or all parts of the external female genitalia. FGM/C is carried out by traditional circumcisers. They usually use cutting tools like a blade or straight-razor. Although FGM/C is well described in the African continent and some Arabic countries, data from Iran are scarce. The major objective of this current study was to investigate the effects of FGM/C on the female sexual function of married women compared to the non-circumcised women in the Kurdistan province of Iran. A case-control study was conducted in a sample of 280 married women (140 circumcised-women and 140 non-circumcised-women) who referred to the healthcare centers for vaccination, midwifery, or family planning services. Participants were requested to complete the Persian-translated version of the Female Sexual Function Index. The total score of the FSFI and its individual domains. Of the circumcised women, 51.4% reported circumcision procedures before the age of 3 years. Religion motivation (53.6%) was mentioned as the most important factor for the family leading to FGM/C. Almost all operations were performed by traditional circumcisers. Non-circumcised women had significantly higher Persian-FSFI total score (25.3 ± 4.34) compared to the circumcised women (17.9 ± 5.39). Sexual function in women with FGM/C is adversely altered. In Kurdistan province women, FGM/C is associated with reduction of scores of Persian-FSFI on all domain scores. Education in general and informing the people that FGM/C is not a religious Hadith certainly would have a great impact on the suffering of the women from FGM/C as well as the level of "desire, arousal, lubrication, orgasm, satisfaction, and pain in the sexual function of women". Copyright © 2016 Elsevier B.V. All rights reserved.

The role of men in abandonment of female genital mutilation: a systematic review.

PubMed

Varol, Nesrin; Turkmani, Sabera; Black, Kirsten; Hall, John; Dawson, Angela

2015-10-08

Men in their roles as fathers, husbands, community and religious leaders may play a pivotal part in the continuation of female genital mutilation (FGM). However, the research on their views of FGM and their potential role in its abandonment are not well described. We undertook a systematic review of all publications between 2004 and 2014 that explored men's attitudes, beliefs, and behaviours in regards to FGM, as well as their ideas about FGM prevention and abandonment. We included twenty peer-reviewed articles from 15 countries in the analysis. Analysis revealed ambiguity of men's wishes in regards to the continuation of FGM. Many men wished to abandon this practice because of the physical and psychosexual complications to both women and men. Social obligation and the silent culture between the sexes were posited as major obstacles for change. Support for abandonment was influenced by notions of social obligation, religion, education, ethnicity, urban living, migration, and understanding of the negative sequelae of FGM. The strongest influence was education. The level of education of men was one of the most important indicators for men's support for abandonment of FGM. Social obligation and the lack of dialogue between men and women were two key issues that men acknowledged as barriers to abandonment. Advocacy by men and collaboration between men and women's health and community programs may be important steps forward in the abandonment process.

Thermoviscoelastoplastic Deformation of Compound Shells of Revolution Made of a Damageable Material

NASA Astrophysics Data System (ADS)

Shevchenko, Yu. N.; Galishin, A. Z.; Babeshko, M. E.

2015-11-01

A technique for numerical analysis of the thermoviscoelastoplastic deformation of thin compound shells made of a damageable material in which a fracture front propagates is described. A procedure for automatic variation in the step of integration of the kinetic damage equation is developed. A two-layer cylindrical shell cooling by convection and subjected to internal pressure and tensile force is analyzed as an example. The numerical data are presented and analyzed

High-pressure structure made of rings with peripheral weldments of reduced thickness

DOEpatents

Leventry, Samuel C.

1988-01-01

A high-pressure structure having a circular cylindrical metal shell made of metal rings joined together by weldments and which have peripheral areas of reduced shell thickness at the weldments which permit a reduction in the amount of weld metal deposited while still maintaining sufficient circumferential or hoop stress strength.

A pressurized cylindrical shell with a fixed end which contains an axial part-through or through crack

NASA Technical Reports Server (NTRS)

Yahsi, O. S.; Erdogan, F.

1983-01-01

A cylindrical shell having a very stiff and plate or a flange is considered. It is assumed that near the end the cylinder contains an axial flaw which may be modeled as a part through surface crack or a through crack. The effect of the end constraining on the stress intensity factor which is the main fracture mechanics parameter is studied. The applied loads acting on the cylinder are assumed to be axisymmetric. Thus the crack problem under consideration is symmetric with respect to the plane of the crack and consequently only the Mode 1 stress intensity factors are nonzero. With this limitation, the general perturbation problem for a cylinder with a built in end containing an axial crack is considered. Reissner's shell theory is used to formulate the problem. The part through crack problem is treated by using a line spring model. In the case of a crack tip terminating at the fixed end it is shown that the integral equations of the shell problem has the same generalized Cauchy kernel as the corresponding plane stress elasticity problem.

Analysis of different techniques to improve sound transmission loss in cylindrical shells

NASA Astrophysics Data System (ADS)

Oliazadeh, Pouria; Farshidianfar, Anooshiravan

2017-02-01

In this study, sound transmission through double- and triple-walled shells is investigated. The structure-acoustic equations based on Donnell's shell theory are presented and transmission losses calculated by this approach are compared with the transmission losses obtained according to Love's theory. An experimental set-up is also constructed to compare natural frequencies obtained from Donnell and Love's theories with experimental results in the high frequency region. Both comparisons show that Donnell's theory predicts the sound transmission characteristics and vibrational behavior better than Love's theory in the high frequency region. The transmission losses of the double- and triple-walled construction are then presented for various radii and thicknesses. Then the effects of air gap size as an important design parameter are studied. Sound transmission characteristics through a circular cylindrical shell are also computed along with consideration of the effects of material damping. Modest absorption is shown to greatly reduce the sound transmission at ring frequency and coincidence frequency. Also the effects of five common gases that are used for filling the gap are investigated.

Processing and Testing of Thermoplastic Composite Cylindrical Shells Fabricated by Automated Fiber Placement

NASA Technical Reports Server (NTRS)

Hulcher, Anthony Bruce; McGowan, David M.; Grimsley, Brian W.; Johnston, Norman J.; Gordon, Gail H. (Technical Monitor)

2001-01-01

Two 61-cm-diameter eight-ply quasi-isotropic IM7/PEEK cylindrical shells were fabricated by automated fiber placement the NASA Langley Research Center using only infrared radiant heat to preheat the substrate and incoming composite uni-tape. The shells were characterized by ultrasonic c-scans for overall consolidation quality, and by optical microscopy and acid digestion for void content. Compression tests were also performed. Although the material used in the study was of generally poor quality due to numerous splits and dry fiber regions, the process was able to achieve a net reduction in void content in the as-placed component. Microscopy of the composite shells revealed well-consolidated, void-free interfaces. The two cylinders were then tested in uni-axial compression in a 1334 kN-capacity hydraulic test machine until buckling occurred. A geometrically nonlinear finite element analysis was conducted, and the differences between the predicted and measured values were 18.0 and 25.8%, respectively. Inclusion of measured imperfections of the cylinder into the analysis is expected to reduce these differences.

Injured bodies, damaged lives: experiences and narratives of Kenyan women with obstetric fistula and Female Genital Mutilation/Cutting.

PubMed

Mwanri, Lillian; Gatwiri, Glory Joy

2017-03-14

It is well acknowledged that Female Genital Mutilation/Cutting (FGM/C/C) leads to medical, psychological and sociocultural sequels. Over 200 million cases of FGM/C exist globally, and in Kenya alone, a total of 12,418,000 (28%) of women have undergone FGM/C, making the practice not only a significant national, but also a global health catastrophe. FGM/C is rooted in patriarchal and traditional cultures as a communal experience signifying a transition from girlhood to womanhood. The conversations surrounding FGM/C have been complicated by the involvement of women themselves in perpetuating the practice. A qualitative inquiry employing face-to-face, one-on-one, in-depth semi-structured interviews was used in a study that included 30 women living with obstetric fistulas in Kenya. Using the Social Network Framework and a feminist analysis we present stories of Kenyan women who had developed obstetric fistulas following prolonged and obstructed childbirth. Of the 30 participants, three women reported that health care workers informed them that FGM/C was one of the contributing factors to their prolonged and obstructed childbirth. They reported serious obstetric complications including: the development of obstetric fistulas, lowered libido, poor quality of life and maternal and child health outcomes, including death. Fistula and subsequent loss of bodily functionalities such as uncontrollable leakage of body wastes, was reported by the women to result in rejection by spouses, families, friends and communities. Rejection further led to depression, loss of work, increased sense of apathy, lowered self-esteem and image, as well as loss of identity and communal sociocultural cohesion. FGM/C is practised in traditional, patriarchal communities across Africa. Although the practice aims to bind community members and to celebrate a rite of passage; it may lead to harmful health and social consequences. Some women with fistula report their fistula was caused by FGM/C. Concerted efforts which embrace feminist understandings of society, as well as multi-sectoral, multidisciplinary and community development approaches need to be employed to address FGM/C, and to possibly reduce cases of obstetric fistulas in Kenya and beyond. Both government and non-government organisations need to be involved in making legislative, gender sensitive policies that protect women from FGM/C. In addition, the policy makers need to be in the front line to improve the lives of women who endured the consequences of FGM/C.

Prevalence of female genital mutilation among female infants in Kano, Northern Nigeria.

PubMed

Garba, I D; Muhammed, Z; Abubakar, I S; Yakasai, I A

2012-08-01

To determine the prevalence and type of female genital mutilation (FGM) among female infants, reasons and attitude of the mothers to the practice. A cross sectional descriptive study. Tertiary centre in Kano Northern Nigeria. A Pretested questionnaire was administered for mothers of female infants presenting for routine immunization in Aminu Kano Teaching Hospital (AKTH). A total of 250 questionnaires were administered, but only 200 were properly filled and this was used for the analysis. Prevalence and type of FGM, reason for and attitude of mothers towards FGM. Twenty-six infants had FGM during the period of study, giving a prevalence rate of 13 %. The mean age at cutting was 8 days ± 7.3. The commonest type of FGM was type I accounting for 96.2 % of the cases. Tradition/culture was the commonest reason for mutilation accounting for 73.1 %, other reasons included; religious in 11.5 %, hygienic in 11.5 % and to preserve virginity in 3.8 %. Traditional barbers were the commonest operators in 80.8 % of cases, followed by the nurse/midwife in 15.4 % of cases. The fathers were the main decision makers in 46.2 %, followed by both parents in 26.9 % and grandparents in 15.4 % of the cases. 84 % of mothers were not in support of the practice. Thirteen percent of the clients would circumcise all their daughters. Forty-eight percent of the clients were of the opinion that FGM cause harm to the victims. Four percent of those whose daughters were yet to be circumcised will do so later. Female genital cutting is still practiced in our environment. Educational enlightenment is fundamental in changing public opinion as well as in offering reasonable alternative to FGM. Campaign against the practice of FGM should be encouraged to eradicate its practice.

Medicalized Female Genital Mutilation/Cutting: Contentious Practices and Persistent Debates.

PubMed

Kimani, Samuel; Shell-Duncan, Bettina

2018-01-01

Female genital cutting/mutilation (FGM/C) performed by health care professionals (medicalization) and reduced severity of cutting have been advanced as strategies for minimizing health risks, sparking acrimonious ongoing debates. This study summarizes key debates and critically assesses supporting evidence. While medicalization is concentrated in Africa, health professionals worldwide have faced requests to perform FGM/C. Whether medicalization is hindering the decline of FGM/C is unclear. Factors motivating medicalization include, but are not limited to, safety concerns. Involvement of health professionals in advocacy to end FGM/C can address both the supply and demand side of medicalization, but raises ethical concerns regarding dual loyalty. Ongoing debates need to address competing rights claims. Polarizing debates have brought little resolution. We call for a focus on common goals of protecting the health and welfare of girls living in communities where FGM/C is upheld and encourage more informed and open dialog.

Folding to Curved Surfaces: A Generalized Design Method and Mechanics of Origami-based Cylindrical Structures.

PubMed

Wang, Fei; Gong, Haoran; Chen, Xi; Chen, C Q

2016-09-14

Origami structures enrich the field of mechanical metamaterials with the ability to convert morphologically and systematically between two-dimensional (2D) thin sheets and three-dimensional (3D) spatial structures. In this study, an in-plane design method is proposed to approximate curved surfaces of interest with generalized Miura-ori units. Using this method, two combination types of crease lines are unified in one reprogrammable procedure, generating multiple types of cylindrical structures. Structural completeness conditions of the finite-thickness counterparts to the two types are also proposed. As an example of the design method, the kinematics and elastic properties of an origami-based circular cylindrical shell are analysed. The concept of Poisson's ratio is extended to the cylindrical structures, demonstrating their auxetic property. An analytical model of rigid plates linked by elastic hinges, consistent with numerical simulations, is employed to describe the mechanical response of the structures. Under particular load patterns, the circular shells display novel mechanical behaviour such as snap-through and limiting folding positions. By analysing the geometry and mechanics of the origami structures, we extend the design space of mechanical metamaterials and provide a basis for their practical applications in science and engineering.

Folding to Curved Surfaces: A Generalized Design Method and Mechanics of Origami-based Cylindrical Structures

NASA Astrophysics Data System (ADS)

Wang, Fei; Gong, Haoran; Chen, Xi; Chen, C. Q.

2016-09-01

Origami structures enrich the field of mechanical metamaterials with the ability to convert morphologically and systematically between two-dimensional (2D) thin sheets and three-dimensional (3D) spatial structures. In this study, an in-plane design method is proposed to approximate curved surfaces of interest with generalized Miura-ori units. Using this method, two combination types of crease lines are unified in one reprogrammable procedure, generating multiple types of cylindrical structures. Structural completeness conditions of the finite-thickness counterparts to the two types are also proposed. As an example of the design method, the kinematics and elastic properties of an origami-based circular cylindrical shell are analysed. The concept of Poisson’s ratio is extended to the cylindrical structures, demonstrating their auxetic property. An analytical model of rigid plates linked by elastic hinges, consistent with numerical simulations, is employed to describe the mechanical response of the structures. Under particular load patterns, the circular shells display novel mechanical behaviour such as snap-through and limiting folding positions. By analysing the geometry and mechanics of the origami structures, we extend the design space of mechanical metamaterials and provide a basis for their practical applications in science and engineering.

Folding to Curved Surfaces: A Generalized Design Method and Mechanics of Origami-based Cylindrical Structures

PubMed Central

Wang, Fei; Gong, Haoran; Chen, Xi; Chen, C. Q.

2016-01-01

Origami structures enrich the field of mechanical metamaterials with the ability to convert morphologically and systematically between two-dimensional (2D) thin sheets and three-dimensional (3D) spatial structures. In this study, an in-plane design method is proposed to approximate curved surfaces of interest with generalized Miura-ori units. Using this method, two combination types of crease lines are unified in one reprogrammable procedure, generating multiple types of cylindrical structures. Structural completeness conditions of the finite-thickness counterparts to the two types are also proposed. As an example of the design method, the kinematics and elastic properties of an origami-based circular cylindrical shell are analysed. The concept of Poisson’s ratio is extended to the cylindrical structures, demonstrating their auxetic property. An analytical model of rigid plates linked by elastic hinges, consistent with numerical simulations, is employed to describe the mechanical response of the structures. Under particular load patterns, the circular shells display novel mechanical behaviour such as snap-through and limiting folding positions. By analysing the geometry and mechanics of the origami structures, we extend the design space of mechanical metamaterials and provide a basis for their practical applications in science and engineering. PMID:27624892

Modeling of composite coupling technology for oil-gas pipeline section resource-saving repair

NASA Astrophysics Data System (ADS)

Donkova, Irina; Yakubovskiy, Yuriy; Kruglov, Mikhail

2017-10-01

The article presents a variant of modeling and calculation of a main pipeline repair section with a composite coupling installation. This section is presented in a shape of a composite cylindrical shell. The aim of this work is mathematical modeling and study of main pipeline reconstruction section stress-strain state (SSS). There has been given a description of a structure deformation mathematical model. Based on physical relations of elasticity, integral characteristics of rigidity for each layer of a two-layer pipe section have been obtained. With the help of the systems of forces and moments which affect the layers differential equations for the first and second layer (pipeline and coupling) have been obtained. The study of the SSS has been conducted using the statements and hypotheses of the composite structures deformation theory with consideration of interlayer joint stresses. The relations to describe the work of the joint have been stated. Boundary conditions for each layer have been formulated. To describe the deformation of the composite coupling with consideration of the composite cylindrical shells theory a mathematical model in the form of a system of differential equations in displacements and boundary conditions has been obtained. Calculation of a two-layer cylindrical shell under the action of an axisymmetric load has been accomplished.

Analysis of dry friction damping characteristics for short cylindrical shell structures

NASA Astrophysics Data System (ADS)

Wang, Nengmao; Wang, Yanrong

2018-05-01

An efficient mathematical model to describe the friction of short cylindrical shell structures with a dry friction damping sleeve is proposed. The frictional force in the circumference and axial direction is caused by the opposing bending strains at the interface. Slipping will occur at part region of the interface and the mathematic model of the slipping region is established. Ignoring the effect of contact stiffness on the vibration analysis, the friction energy dissipation capability of damping sleeve would be calculated. Structural vibration mode, positive pressure at the interface and vibration stress of the short cylindrical shell structures is analyzed as influence factors to the critical damping ratio. The results show that the circumferential friction energy dissipation is more sensitive to the number of nodal diameter, and the circumferential friction damping ratio increases rapidly with the number of nodal diameter. The slipping frictional force would increase along with the positive pressure, but the slipping region would decrease with it. The peak damping ratio keeps nearly constant. But the vibration stress corresponding to peak damping ratio would increases with the positive pressure. The dry friction damping ratio of damping sleeve contains the effect of frictional force in the circumference and axial direction, and the axial friction plays a major role.

Modelling the structure and kinematics of the Firework nebula: The nature of the GK Persei nova shell and its jet-like feature

NASA Astrophysics Data System (ADS)

Harvey, E.; Redman, M. P.; Boumis, P.; Akras, S.

2016-10-01

Aims: The shaping mechanisms of old nova remnants are probes for several important and unexplained processes, such as dust formation and the structure of evolved star nebulae. To gain a more complete understanding of the dynamics of the GK Per (1901) remnant, an examination of symmetry of the nova shell is explored, followed by a kinematical analysis of the previously detected jet-like feature in the context of the surrounding fossil planetary nebula. Methods: Faint-object high-resolution echelle spectroscopic observations and imaging were undertaken covering the knots which comprise the nova shell and the surrounding nebulosity. New imaging from the Aristarchos telescope in Greece and long-slit spectra from the Manchester Echelle Spectrometer instrument at the San Pedro Mártir observatory in Mexico were obtained, supplemented with archival observations from several other optical telescopes. Position-velocity arrays are produced of the shell, and also individual knots, and are then used for morpho-kinematic modelling with the shape code. The overall structure of the old knotty nova shell of GK Per and the planetary nebula in which it is embedded is then analysed. Results: Evidence is found for the interaction of knots with each other and with a wind component, most likely the periodic fast wind emanating from the central binary system. We find that a cylindrical shell with a lower velocity polar structure gives the best model fit to the spectroscopy and imaging. We show in this work that the previously seen jet-like feature is of low velocity. Conclusions: The individual knots have irregular tail shapes; we propose here that they emanate from episodic winds from ongoing dwarf nova outbursts by the central system. The nova shell is cylindrical, not spherical, and the symmetry axis relates to the inclination of the central binary system. Furthermore, the cylinder axis is aligned with the long axis of the bipolar planetary nebula in which it is embedded. Thus, the central binary system is responsible for the bipolarity of the planetary nebula and the cylindrical nova shell. The gradual planetary nebula ejecta versus sudden nova ejecta is the reason for the different degrees of bipolarity. We propose that the "jet" feature is an illuminated lobe of the fossil planetary nebula that surrounds the nova shell.

Female genital mutilation: a urology focus.

PubMed

Clarke, Elinor

2016-10-13

Female genital mutilation (FGM) is a collective term for the deliberate alteration, removal and cutting of the female genitalia. It has no known health benefits and can have negative physical and psychological consequences. The number of women and girls in the UK that are affected by FGM is unknown. Recent NHS data suggested that FGM has been evident (declared or observed) in women who have accessed health care; however, there are gaps in knowledge and a limited evidence base on the health consequences of FGM. This article explores the urological complications experienced by women who have undergone this practice, and the effects this can have on their health and wellbeing.

Egyptian government broadens ban on female genital mutilation.

PubMed

1996-01-01

An estimated 70-90% of girls in Egypt are subjected to female genital mutilation (FGM) before reaching puberty. Many Egyptians believe the practice to be ordained by Islam. Whether this is true, however, remains an issue of debate among Muslim scholars. Some Egyptian Christians also secure FGM for their girls. Egyptian law prohibits anyone without medical training from performing FGM, and any physician or health worker who causes permanent damage to a girl may face 3-10 years of hard labor. However, the law is frequently ignored, especially in rural areas, where village barbers and midwives perform the operations. In October 1995, Egyptian state hospitals were banned from performing FGM. Egypt has since broadened its ban to bar all health care workers in both state-run hospitals and private clinics from performing the procedure. No health care worker affiliated with the Ministry of Health is therefore allowed to perform FGM. Almost all Egyptian doctors are affiliated with the Ministry. While this recent move by the Health Minister is laudable, it remains to be seen whether he can enforce it. The secretary-general of the Egyptian Organization for Human Rights has urged parliament to enact legislation criminalizing FGM.

Composite laminated shells under internal pressure

NASA Technical Reports Server (NTRS)

Yuan, F. G.

1992-01-01

A theoretical study is conducted of the response of filament-wound composite shells under internal pressure; a system of sixth-order ordinary differential equations is obtained by means of the cylindrically anisotropic elasticity field equations and Lekhnitskii's (1963) stress functions. The general expressions for the stresses and displacements in the laminated composite shells under internal pressure are discussed. Attention is given to the influence of the degree of material anisotropy and fiber orientation on the axial and induced twisting deformation.

A description of female genital mutilation and force-feeding practices in Mauritania: implications for the protection of child rights and health.

PubMed

Ouldzeidoune, Nacerdine; Keating, Joseph; Bertrand, Jane; Rice, Janet

2013-01-01

To establish the prevalence of female genital mutilation (FGM) and force feeding (gavage) practices among children in Mauritania; to investigate factors related to FGM and gavage practices and attitude in Mauritania; and to explore implications related to the protection of children's rights and welfare. Data from the Mauritania 2000-2001 DHS were used in this analysis. Data were collected from men and women about their attitude toward the continuation of FGM and gavage; women only were asked if they ever experienced one of these practices. Chi-square statistics were used to investigate differences in attitude and practice of FGM and gavage by demographic characteristics. Binary logistic regression was used to identify socio-demographic factors related to FGM and gavage outcomes. The overall prevalence of FGM was 77% but varied depending on ethnicity. The majority of both female and male respondents favored the continuation of the practice (64% and 70%, respectively). Almost a quarter (23%) of women reported being force fed as a child and 32% of women and 29% of men approved the continuation of the practice. Gavage is almost exclusively practiced among Arabs. The practice of both FGM and gavage is ongoing, although the prevalence and attitude towards both appears to vary as a function of ethnicity, wealth, education, marital status, and age. Contextually relevant intervention and enforcement strategies are needed to challenge these cultural norms and protect the rights and welfare of children in Mauritania.

Synthesis and microwave absorbing characteristics of functionally graded carbonyl iron/polyurethane composites

NASA Astrophysics Data System (ADS)

Yang, R. B.; Liang, W. F.; Wu, C. H.; Chen, C. C.

2016-05-01

Radar absorbing materials (RAMs) also known as microwave absorbers, which can absorb and dissipate incident electromagnetic wave, are widely used in the fields of radar-cross section reduction, electromagnetic interference (EMI) reduction and human health protection. In this study, the synthesis of functionally graded material (FGM) (CI/Polyurethane composites), which is fabricated with semi-sequentially varied composition along the thickness, is implemented with a genetic algorithm (GA) to optimize the microwave absorption efficiency and bandwidth of FGM. For impedance matching and broad-band design, the original 8-layered FGM was obtained by the GA method to calculate the thickness of each layer for a sequential stacking of FGM from 20, 30, 40, 50, 60, 65, 70 and 75 wt% of CI fillers. The reflection loss of the original 8-layered FGM below -10 dB can be obtained in the frequency range of 5.12˜18 GHz with a total thickness of 9.66 mm. Further optimization reduces the number of the layers and the stacking sequence of the optimized 4-layered FGM is 20, 30, 65, 75 wt% with thickness of 0.8, 1.6, 0.6 and 1.0 mm, respectively. The synthesis and measurement of the optimized 4-layered FGM with a thickness of 4 mm reveal a minimum reflection loss of -25.2 dB at 6.64 GHz and its bandwidth below - 10 dB is larger than 12.8 GHz.

Experimental Approach on the Behavior of Composite Laminated Shell under Transverse Impact Loading

NASA Astrophysics Data System (ADS)

Kim, Y. N.; Im, K. H.; Lee, K. S.; Cho, Y. J.; Kim, S. H.; Yang, I. Y.

2005-04-01

Composites are to be considered for many structural applications structural weight. These materials have high strength-to-weight and stiffness-to-weight ratios. However, they are susceptible to impact loading because they are laminar systems with weak interfaces. Matrix cracking and delamination are the most common damage mechanisms of low velocity impact and are dependent on each other. This paper is to study the behavior of composite shell under transverse impact loading. In this study, carbon-epoxy composite laminates with various curvatures was used. Low velocity impact tests were performed using a drop weight testing machine. The 100mm×100mm shells were clamped in order to produce a central circular area (φ=80mm). An hemispherical impactor (m=0.1kg and φ=10mm) was used and the tests were done with velocities ranging from 2.8 to 4.8 m/s. The real curve force/time was registered in order to obtain the maximum contact force and contact time. And then, we know that contact force and delamination area of flat-plate is higher than cylindrical shell panel in the same kinetic energy level, and flat-plate is easily penetrated than cylindrical shell panel. And contact force, deflection and delamination area decrease as the curvature increase.

Revision of the genus Cuvierina Boas, 1886 based on integrative taxonomic data, including the description of a new species from the Pacific Ocean (Gastropoda, Thecosomata)

PubMed Central

Burridge, Alice K.; Janssen, Arie W.; Peijnenburg, Katja T.C.A.

2016-01-01

Abstract Shelled pteropods (Gastropoda, Thecosomata, Euthecosomata) are a group of holoplanktonic gastropods that occur predominantly in the surface layers of the world’s oceans. Accurate species identifications are essential for tracking changes in species assemblages of planktonic gastropods, because different species are expected to have different sensitivities to ocean changes. The genus Cuvierina has a worldwide warm water distribution pattern between ~36°N and ~39°S. Based on an integrative taxonomic approach combining morphometric, genetic, and biogeographic information, the two subgenera of Cuvierina, Cuvierina s. str. and Urceolarica, are rejected. A new species is introduced: Cuvierina tsudai sp. n., which has to date been considered the same species as Cuvierina pacifica. Cuvierina tsudai sp. n. is endemic to the Pacific Ocean and is characterised by a shell height of 7.2-8.0 mm, a moderately cylindrical shell shape, the absence of micro-ornamentation and a triangular aperture. Cuvierina pacifica is restricted to the centre of the oligotrophic southern Pacific gyre, has a shell height of 6.6-8.5 mm, a more cylindrical shell shape, no micro-ornamentation and a less triangular aperture than Cuvierina tsudai sp. n. PMID:27829786

Temperature and hydrostatic pressure effects on single dopant states in hollow cylindrical core-shell quantum dot

NASA Astrophysics Data System (ADS)

El-Yadri, M.; Aghoutane, N.; El Aouami, A.; Feddi, E.; Dujardin, F.; Duque, C. A.

2018-05-01

This work reports on theoretical investigation of the temperature and hydrostatic pressure effects on the confined donor impurity in a AlGaAs-GaAs hollow cylindrical core-shell quantum dot. The charges are assumed to be completely confined to the interior of the shell with approximately rigid walls. Within the framework of the effective-mass approximation and by using a variational approach, we have computed the donor binding energies as a function of the shell size in order to study the behavior of the electron-impurity attraction for a very small thickness under the influence of both temperature and hydrostatic pressure. Our results show that the temperature and hydrostatic pressure have a significant influence on the impurity binding energy for large shell quantum dots. It will be shown that the binding energy is more pronounced with increasing pressure and decreasing temperature for any impurity position and quantum dot size. The photoionization cross section is also analyzed by considering only the in-plane incident radiation polarization. Its behavior is investigated as a function of photon energy for different values of pressure and temperature. The opposite effects caused by temperature and hydrostatic pressure reveal a big practical interest and offer an alternative way to tuning of correlated electron-impurity transitions in optoelectronic devices.

The Effects of Geometric and Loading Imperfections on the Response and Lower-Bound Buckling Load of a Compression-Loaded Cylindrical Shell

NASA Technical Reports Server (NTRS)

Kriegesmann, Benedikt; Hilburger, Mark W.; Rolfes, Raimund

2012-01-01

Results from a numerical study of the buckling response of a thin-walled compressionloaded isotropic circular cylindrical shell with initial geometric and loading imperfections are used to determine a lower bound buckling load estimate suitable for preliminary design. The lower bound prediction techniques presented herein include an imperfection caused by a lateral perturbation load, an imperfection in the shape of a single stress-free dimple (similar to the lateral pertubation imperfection), and a distributed load imperfection that induces a nonuniform load in the shell. The ABAQUS finite element code is used for the analyses. Responses of the cylinders for selected imperfection amplitudes and imperfection types are considered, and the effect of each imperfection is compared to the response of a geometrically perfect cylinder. The results indicate that compression-loaded shells subjected to a lateral perturbation load or a single dimple imperfection, and a nonuniform load imperfection, exhibit similar buckling behavior and lower bound trends and the predicted lower bounds are much less conservative than the corresponding design recommendation NASA SP-8007 for the design of buckling-critical shells. In addition, the lateral perturbation technique and the distributed load imperfection produce response characteristics that are physically meaningful and can be validated via laboratory testing.

Female genital mutilation: prevalence, perceptions and effect on women’s health in Kersa district of Ethiopia

PubMed Central

Yirga, Wondimu Shanko; Kassa, Nega Assefa; Gebremichael, Mengistu Welday; Aro, Arja R

2012-01-01

Background Female genital mutilation (FGM) is nontherapeutic surgical modification of the female genitalia. It is an ancient tradition in large parts of Africa, including Ethiopia, especially in the eastern part of the country. This study aimed to identify the prevalence, perceptions, perpetuators, reasons for conducting FGM, and factors associated with this practice with regard to women’s health. Methods Community-based cross-sectional house-to-house interviews were conducted during 2008 among 858 females of reproductive age (15–49 years), in Kersa district, East Hararge, Oromia region, Ethiopia. Proportions and Chi-square tests were used to describe the data and logistic regression was used to describe statistical associations. Statistical significance was set at P < 0.05. Results FGM was reported to be known by 327 (38.5%) of the interviewees. The majority (n = 249, 76.1%) reported that local healers were the main performers of FGM, and 258 (78.9%) respondents stated that the clitoris was the part removed during circumcision. The main reason for the practice of FGM was reduction of female sexual hyperactivity (reported by 198 women [60.3%]). Circumcision of daughters was reported by 288 (88.1%) respondents, and this showed a statistically significant association with the Christian religion (P = 0.003), illiteracy (P = 0.01), and Amhara ethnicity (P = 0.012). The majority of the respondents (792, 92.3%) were themselves circumcised and 68.8% did not know of any health-related problems associated with FGM. Conclusion In spite of FGM being a common practice in the study area, only one third of the respondents stated that they knew about it. Local healers were the main performers of FGM. Some of the women knew about the negative reproductive health effects of FGM and some had also experienced these themselves. However, only a few had tried to stop the practice and the majority had taken no steps to do so. This may be attributable to the fear of becoming alienated from the cultural system and fear of isolation. PMID:22371659

Dispelling the myths and beliefs toward female genital cutting of woman: assessing general outpatient services at a tertiary health institution in Enugu state, Nigeria.

PubMed

Ekwueme, O C; Ezegwui, H U; Ezeoke, U

2010-03-01

The practice of female genital mutilation (FGM) has continued because it is deeply entrenched in tradition and culture especially in developing countries where the victims are often its strongest proponents. This study aimed at using accurate information to dispel the traditional myths and beliefs about FGM among woman. Using a before and after intervention evaluation research design, interviewer administered questionnaires were administered to a sample of 100 women drawn by systematic sampling from the General Outpatient Department of University of Nigeria Teaching Hospital. Information's on their knowledge, attitude and behaviour towards FGM were elicited pre-and-post intervention. Pre-intervention, knowledge of the respondents on the true meaning of FGM was 54% and that of the 6 complications enlisted on average was 22.2%. Seventy (70.0%) believed that FCM is good and should be continued based mainly on culture and tradition (85.7%). Among the 29(29.0%) respondents against FGM, 26(89.7%) and 24(82.8%) said it increases risk of HIV/AIDS and pregnancy complications respectively. Respondents displayed a high negative and stigmatizing attitude toward the uncircumcised women. Seventy-four (74.0%) said they are promiscuous. Additionally, 49% said they are shameful, 14% cursed/outcast while 66% would not recommend them for marriage. Post-intervention, 85% of the respondents now understood full meaning of FGM and 71.3% on the average knew the complications. While only 11% now support FGM, 83% were against the practice. The stigmatizing attitudes held against uncircumcised women decreased significantly from baseline to post-intervention as follows: promiscuous 74% to 22%, shameful 49% to 12%, outcast/cursed 14% to 2%, and not good for marriage from 66% to 19%. The differences in the baseline and post-intervention data on knowledge, beliefs and attitudes of the respondents toward FGM were statistically significant (p < 0.001). Educational intervention programme has been successful used to impact knowledge, change beliefs and negative attitudes of women toward FGM.

Scattering of Cylindrical Electric Field Waves from an Elliptical Dielectric Cylindrical Shell.

DTIC Science & Technology

1982-12-01

account for the cyber is immeasurable.. Thanks are due to my advisor, Captain Thomas W. Johnson, who was personally excited and motivated by the...DCADRE( PS4 , NU1, NU2,0. 0, 1.0r.3, ERR, IER) VXNf~(!I) - CMfPLX(V?!NR,VMrI) RMIAC - SQRT(VM M%**2 + VIINI**2) PHASE - ATAN(VffN.I/VINT) * (180.0/PI

Granular Silo collapse: an experimental study

NASA Astrophysics Data System (ADS)

Clement, Eric; Gutierriez, Gustavo; Boltenhagen, Philippe; Lanuza, Jose

2008-03-01

We present an experimental work that develop some basic insight into the pre-buckling behavior and the buckling transition toward plastic collapse of a granular silo. We study different patterns of deformation generated on thin paper cylindrical shells during granular discharge. We study the collapse threshold for different bed height, flow rates and grain sizes. We compare the patterns that appear during the discharge of spherical beads, with those obtained in the axially compressed cylindrical shells. When the height of the granular column is close to the collapse threshold, we describe a ladder like pattern that rises around the cylinder surface in a spiral path of diamond shaped localizations, and develops into a plastic collapsing fold that grows around the collapsing silo.

Research gaps in the care of women with female genital mutilation: an analysis.

PubMed

Abdulcadir, J; Rodriguez, M I; Say, L

2015-02-01

Female genital mutilation (FGM) includes procedures involving the partial or total removal of the external female genitals for non-therapeutic reasons. They can have negative psychosexual and health consequences that need specific care. In this paper, we review some key knowledge gaps in the clinical care of women with FGM, focusing on obstetric outcomes, surgical interventions (defibulation and clitoral reconstruction), and the skills and training of healthcare professionals involved in the prevention and management of FGM. We identify research priorities to improve the evidence necessary to establish guidelines for the best multidisciplinary care, communication, and prevention, and to improve health-promotion measures for women with FGM. © 2014 Royal College of Obstetricians and Gynaecologists.

Effect of gradient dielectric coefficient in a functionally graded material (FGM) substrate on the propagation behavior of love waves in an FGM-piezoelectric layered structure.

PubMed

Cao, Xiaoshan; Shi, Junping; Jin, Feng

2012-06-01

The propagation behavior of Love waves in a layered structure that includes a functionally graded material (FGM) substrate carrying a piezoelectric thin film is investigated. Analytical solutions are obtained for both constant and gradient dielectric coefficients in the FGM substrate. Numerical results show that the gradient dielectric coefficient decreases phase velocity in any mode, and the electromechanical coupling factor significantly increases in the first- and secondorder modes. In some modes, the difference in Love waves' phase velocity between these two types of structure might be more than 1%, resulting in significant differences in frequency of the surface acoustic wave devices.

Closure system

DOEpatents

Hertelendy, N.A.

1987-04-22

A pressure resistant seal for a metallic container is formed between a cylindrical portion having one end open and a cap which seals the open end of the shell. The cap is in the form of a frusto-conical flange which is inserted narrow end first into the open end of the shell and the container is sealed by means of a capping tool which pulls the flange against a die, deforming the flange and forcing the edge of the flange into the wall of the shell. 6 figs.

Closure system

DOEpatents

Hertelendy, Nicholas A [Kennewick, WA

1989-01-01

A pressure resistant seal for a metallic container is formed between a cylindrical portion having one end open and a cap which seals the open end of the shell. The cap is in the form of a frusto-conical flange which is inserted narrow end first into the open end of the shell and the container is sealed by means of a capping tool which pulls the flange against a die, deforming the flange and forcing the edge of the flange into the wall of the shell.

Closure system

DOEpatents

Hertelendy, Nicholas A.

1989-04-04

A pressure resistant seal for a metallic container is formed between a cylindrical portion having one end open and a cap which seals the open end of the shell. The cap is in the form of a frusto-conical flange which is inserted narrow end first into the open end of the shell and the container is sealed by means of a capping tool which pulls the flange against a die, deforming the flange and forcing the edge of the flange into the wall of the shell.

Optimum Material Composition for Minimizing the Stress Intensity Factor of Edge Crack in Thick-Walled FGM Circular Pipes Under Thermomechanical Loading

NASA Astrophysics Data System (ADS)

Sekine, Hideki; Yoshida, Kimiaki

This paper deals with the optimization problem of material composition for minimizing the stress intensity factor of radial edge crack in thick-walled functionally graded material (FGM) circular pipes under steady-state thermomechanical loading. Homogenizing the FGM circular pipes by simulating the inhomogeneity of thermal conductivity by a distribution of equivalent eigentemperature gradient and the inhomogeneity of Young's modulus and Poisson's ratio by a distribution of equivalent eigenstrain, we present an approximation method to obtain the stress intensity factor of radial edge crack in the FGM circular pipes. The optimum material composition for minimizing the stress intensity factor of radial edge crack is determined using a nonlinear mathematical programming method. Numerical results obtained for a thick-walled TiC/Al2O3 FGM circular pipe reveal that it is possible to decrease remarkably the stress intensity factor of radial edge crack by setting the optimum material composition profile.

Parametric Study on the Response of Compression-Loaded Composite Shells With Geometric and Material Imperfections

NASA Technical Reports Server (NTRS)

Hilburger, Mark W.; Starnes, James H., Jr.

2004-01-01

The results of a parametric study of the effects of initial imperfections on the buckling and postbuckling response of three unstiffened thinwalled compression-loaded graphite-epoxy cylindrical shells with different orthotropic and quasi-isotropic shell-wall laminates are presented. The imperfections considered include initial geometric shell-wall midsurface imperfections, shell-wall thickness variations, local shell-wall ply-gaps associated with the fabrication process, shell-end geometric imperfections, nonuniform applied end loads, and variations in the boundary conditions including the effects of elastic boundary conditions. A high-fidelity nonlinear shell analysis procedure that accurately accounts for the effects of these imperfections on the nonlinear responses and buckling loads of the shells is described. The analysis procedure includes a nonlinear static analysis that predicts stable response characteristics of the shells and a nonlinear transient analysis that predicts unstable response characteristics.

Review of high convergence implosion experiments with single and double shell targets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delamater, N. D.; Watt, R. G.; Varnum, W. S.

2002-01-01

Experiments have been been performed in recent years at the Omega laser studying double shell capsules as an a1 teinative, 11011 cryogenic, path towards ignition at NTF. Double shell capsules designed to mitigate the Au M-band radiation asymmetries, were experimentally found to perform well in both spherical and cylindrical hohlraums, achieving near 1-D (-90 %) clean calculated yield at convergence comparable to that required for NIF ignition. Near-term plans include directly driven double shell experiments at Omega, which eliminates Au M-band radiation as a yield degradation m ec h an i s in.

Stress Analysis of Composite Cylindrical Shells with an Elliptical Cutout

NASA Technical Reports Server (NTRS)

Oterkus, E.; Madenci, E.; Nemeth, M. P.

2007-01-01

A special-purpose, semi-analytical solution method for determining the stress and deformation fields in a thin laminated-composite cylindrical shell with an elliptical cutout is presented. The analysis includes the effects of cutout size, shape, and orientation; non-uniform wall thickness; oval-cross-section eccentricity; and loading conditions. The loading conditions include uniform tension, uniform torsion, and pure bending. The analysis approach is based on the principle of stationary potential energy and uses Lagrange multipliers to relax the kinematic admissibility requirements on the displacement representations through the use of idealized elastic edge restraints. Specifying appropriate stiffness values for the elastic extensional and rotational edge restraints (springs) allows the imposition of the kinematic boundary conditions in an indirect manner, which enables the use of a broader set of functions for representing the displacement fields. Selected results of parametric studies are presented for several geometric parameters that demonstrate that analysis approach is a powerful means for developing design criteria for laminated-composite shells.

Stress Analysis of Composite Cylindrical Shells With an Elliptical Cutout

NASA Technical Reports Server (NTRS)

Nemeth, M. P.; Oterkus, E.; Madenci, E.

2005-01-01

A special-purpose, semi-analytical solution method for determining the stress and deformation fields in a thin laminated-composite cylindrical shell with an elliptical cutout is presented. The analysis includes the effects of cutout size, shape, and orientation; nonuniform wall thickness; oval-cross-section eccentricity; and loading conditions. The loading conditions include uniform tension, uniform torsion, and pure bending. The analysis approach is based on the principle of stationary potential energy and uses Lagrange multipliers to relax the kinematic admissibility requirements on the displacement representations through the use of idealized elastic edge restraints. Specifying appropriate stiffness values for the elastic extensional and rotational edge restraints (springs) allows the imposition of the kinematic boundary conditions in an indirect manner, which enables the use of a broader set of functions for representing the displacement fields. Selected results of parametric studies are presented for several geometric parameters that demonstrate that analysis approach is a powerful means for developing design criteria for laminated-composite shells.

Bi-orthogonality relations for fluid-filled elastic cylindrical shells: Theory, generalisations and application to construct tailored Green's matrices

NASA Astrophysics Data System (ADS)

Ledet, Lasse S.; Sorokin, Sergey V.

2018-03-01

The paper addresses the classical problem of time-harmonic forced vibrations of a fluid-filled cylindrical shell considered as a multi-modal waveguide carrying infinitely many waves. The forced vibration problem is solved using tailored Green's matrices formulated in terms of eigenfunction expansions. The formulation of Green's matrix is based on special (bi-)orthogonality relations between the eigenfunctions, which are derived here for the fluid-filled shell. Further, the relations are generalised to any multi-modal symmetric waveguide. Using the orthogonality relations the transcendental equation system is converted into algebraic modal equations that can be solved analytically. Upon formulation of Green's matrices the solution space is studied in terms of completeness and convergence (uniformity and rate). Special features and findings exposed only through this modal decomposition method are elaborated and the physical interpretation of the bi-orthogonality relation is discussed in relation to the total energy flow which leads to derivation of simplified equations for the energy flow components.

The Applicability of Behaviour Change in Intervention Programmes Targeted at Ending Female Genital Mutilation in the EU: Integrating Social Cognitive and Community Level Approaches

PubMed Central

Brown, Katherine; Barrett, Hazel

2013-01-01

With increased migration, female genital mutilation (FGM) also referred to as female circumcision or female genital cutting is no longer restricted to Africa, the Middle East, and Asia. The European Parliament estimates that up to half a million women living in the EU have been subjected to FGM, with a further 180,000 at risk. Aware of the limited success of campaigns addressing FGM, the World Health Organization recommended a behavioural change approach be implemented in order to end FGM. To date, however, little progress has been made in adopting a behaviour change approach in strategies aimed at ending FGM. Based on research undertaken as part of the EU's Daphne III programme, which researched FGM intervention programmes linked to African communities in the EU (REPLACE), this paper argues that behaviour change has not been implemented due to a lack of understanding relating to the application of the two broad categories of behaviour change approach: individualistic decision-theoretic and community-change game-theoretic approaches, and how they may be integrated to aid our understanding and the development of future intervention strategies. We therefore discuss how these can be integrated and implemented using community-based participatory action research methods with affected communities. PMID:23983698

A Description of Female Genital Mutilation and Force-Feeding Practices in Mauritania: Implications for the Protection of Child Rights and Health

PubMed Central

Ouldzeidoune, Nacerdine; Keating, Joseph; Bertrand, Jane; Rice, Janet

2013-01-01

Objectives To establish the prevalence of female genital mutilation (FGM) and force feeding (gavage) practices among children in Mauritania; to investigate factors related to FGM and gavage practices and attitude in Mauritania; and to explore implications related to the protection of children’s rights and welfare. Methods Data from the Mauritania 2000–2001 DHS were used in this analysis. Data were collected from men and women about their attitude toward the continuation of FGM and gavage; women only were asked if they ever experienced one of these practices. Chi-square statistics were used to investigate differences in attitude and practice of FGM and gavage by demographic characteristics. Binary logistic regression was used to identify socio-demographic factors related to FGM and gavage outcomes. Findings The overall prevalence of FGM was 77% but varied depending on ethnicity. The majority of both female and male respondents favored the continuation of the practice (64% and 70%, respectively). Almost a quarter (23%) of women reported being force fed as a child and 32% of women and 29% of men approved the continuation of the practice. Gavage is almost exclusively practiced among Arabs. Conclusion The practice of both FGM and gavage is ongoing, although the prevalence and attitude towards both appears to vary as a function of ethnicity, wealth, education, marital status, and age. Contextually relevant intervention and enforcement strategies are needed to challenge these cultural norms and protect the rights and welfare of children in Mauritania. PMID:23593257

Clinical indications for cesarean delivery among women living with female genital mutilation.

PubMed

Rodriguez, Maria I; Say, Lale; Abdulcadir, Jasmine; Hindin, Michelle J

2017-10-01

To compare primary indications for cesarean delivery among patients with different female genital mutilation (FGM) status. The present secondary analysis included data from women who underwent trial of labor resulting in cesarean delivery at 28 obstetric centers in six African countries between November 1, 2001, and March 31, 2003. Associations between cesarean delivery indications and FGM status were assessed using descriptive statistics and multivariable multinomial logistic regression. Data from 1659 women (480 patients with no type of FGM and 1179 patients with FGM [any type]) were included; cesarean delivery indications were collapsed into five categories (fetal indications, maternal factors, stage 1 arrest, stage 2 arrest, and other). The incidence of a clear medical indication for cesarean delivery did not differ between the groups (P=0.320). Among patients without a clear indication for cesarean delivery, women with FGM were more likely to have undergone cesarean delivery for maternal factors (adjusted relative risk ratio [aRRR] 3.92, 95% confidence interval [CI] 1.3-11.71), stage 1 arrest (aRRR 7.74, 95% CI 1.33-45.07), stage 2 arrest (aRRR 6.63, 95% CI 3.74-11.73), or other factors (aRRR 2.41, 95% CI 1.04-5.60) rather than fetal factors compared with women who had no type of FGM. Among women with unclear medical indications, FGM was associated with cesarean delivery being performed for maternal factors or arrest disorders. © 2017 World Health Organization; licensed by John Wiley & Sons Ltd on behalf of International Federation of Gynecology and Obstetrics.

Coping and chronic psychosocial consequences of female genital mutilation in The Netherlands.

PubMed

Vloeberghs, Erick; van der Kwaak, Anke; Knipscheer, Jeroen; van den Muijsenbergh, Maria

2012-01-01

The study presented in this article explored psychosocial and relational problems of African immigrant women in The Netherlands who underwent female genital mutilation/cutting (FGM/C), the causes they attribute to these problems--in particular, their opinions about the relationship between these problems and their circumcision--and the way they cope with these health complaints. This mixed-methods study used standardised questionnaires as well as in-depth interviews among a purposive sample of 66 women who had migrated from Somalia, Sudan, Eritrea, Ethiopia or Sierra Leone to The Netherlands. Data were collected by ethnically similar female interviewers; interviews were coded and analysed by two independent researchers. One in six respondents suffered from post-traumatic stress disorder (PTSD), and one-third reported symptoms related to depression or anxiety. The negative feelings caused by FGM/C became more prominent during childbirth or when suffering from physical problems. Migration to the Netherlands led to a shift in how women perceive FGM, making them more aware of the negative consequences of FGM. Many women felt ashamed to be examined by a physician and avoided visiting doctors who did not conceal their astonishment about the FGM. FGM/C had a lifelong impact on the majority of the women participating in the study, causing chronic mental and psychosocial problems. Migration made women who underwent FGM/C more aware of their condition. Three types of women could be distinguished according to their coping style: the adaptives, the disempowered and the traumatised. Health care providers should become more aware of their problems and more sensitive in addressing them.

Conservation outside protected areas and the effect of human-dominated landscapes on stress hormones in Savannah elephants.

PubMed

Ahlering, M A; Maldonado, J E; Eggert, L S; Fleischer, R C; Western, D; Brown, J L

2013-06-01

Biodiversity conservation strategies are increasingly focused on regions outside national protected areas, where animals face numerous anthropogenic threats and must coexist with human settlements, livestock, and agriculture. The effects of these potential threats are not always clear, but they could have profound implications for population viability. We used savannah elephants (Loxodonta africana) as a case study to assess the physiological stress associated with living in a human-livestock-dominated landscape. We collected samples over two 3-month periods in 2007 and 2008. We used fecal DNA to identify 96 individual elephants in a community conservation area (CCA) and measured fecal glucocorticoid metabolite (FGM) concentrations as a proxy for stress. The CCA is community Maasai land managed for livestock and wildlife. We compared the FGM concentrations from the CCA to FGM concentrations of 40 elephants in Amboseli National Park and 32 elephants in the Maasai Mara National Reserve, where human settlements and intense livestock grazing were absent. In the CCA, we found no significant individual differences in FGM concentrations among the elephants in 2007 (p = 0.312) or 2008 (p = 0.412) and no difference between years (p = 0.616). The elephants in the CCA had similar FGM concentrations to the Maasai Mara population, but Amboseli elephants had significantly lower FGM concentrations than those in either Maasai Mara or the CCA (Tukey pairwise test, p < 0.001), due primarily to females excreting significantly lower FGM relative to males (p = 0.025). In the CCA, there was no relation among female group size, average pairwise group relatedness, and average group FGM concentration. We found no clear evidence of chronic stress in elephants living on CCA communal land, which is encouraging for conservation strategies promoting the protection of animals living outside protected areas. Conservation Biology © 2013 Society for Conservation Biology No claim to original US government works.

Attitude toward female genital mutilation among Somali and Harari people, Eastern Ethiopia

PubMed Central

Abathun, Asresash Demissie; Sundby, Johanne; Gele, Abdi A

2016-01-01

Background Female genital mutilation (FGM) is a worldwide problem, and it is practiced by many communities in Africa and Asia as well as immigrants from those areas. This practice results in short- and long-term health consequences on women’s health. Like many other developing countries, FGM is widely practiced in Ethiopia, especially among Somali and Harari ethnic groups. Despite intensive campaigns against FGM in Ethiopia, since 2011, it has been practiced in the aforementioned communities. There is no recent information as to whether these campaigns have an impact on the attitude and practice of the community regarding FGM. This qualitative research was aimed at exploring the attitudes of Somali and Harari people between 18 and 65 years toward FGM. Methods A purposive sampling technique was used to recruit 64 (32 in each region) participants. Data were collected from October to December 2015 in Somali and Harari Regions. Results The findings showed that there was a strong support for the continuation of the practice among female discussants in Somali region, whereas male discussants from the same region and the majority of the participants from Harari region had a positive attitude toward the discontinuation of the practice. Marriageability was the major reason for practicing FGM in Somali region, whereas making girls calm, sexually inactive, and faithful for their husbands were mentioned in Harari region. Although young men in both the regions prefer to marry uncircumcised girls, the study showed that there are some differences in the attitude toward the FGM practice between the people in the two regions. Conclusion The findings show that there is an attitudinal difference between the people in the two regions, which calls for behavioral change communication using women-centered approach and culturally appropriate strategies. As young people in both the regions had the intention to marry uncircumcised girls, there has to be a strong advocacy and multisectoral collaboration to stop FGM in both the regions. PMID:27785105

Pleasure and orgasm in women with Female Genital Mutilation/Cutting (FGM/C).

PubMed

Catania, Lucrezia; Abdulcadir, Omar; Puppo, Vincenzo; Verde, Jole Baldaro; Abdulcadir, Jasmine; Abdulcadir, Dalmar

2007-11-01

Female genital mutilation/cutting (FGM/C) violates human rights. FGM/C women's sexuality is not well known and often it is neglected by gynecologists, urologists, and sexologists. In mutilated/cut women, some fundamental structures for orgasm have not been excised. The aim of this report is to describe and analyze the results of four investigations on sexual functioning in different groups of cut women. semistructured interviews and the Female Sexual Function Index (FSFI). 137 adult women affected by different types of FGM/C; 58 young FGM/C ladies living in the West; 57 infibulated women; 15 infibulated women after the operation of defibulation. The group of 137 women, affected by different types of FGM/C, reported orgasm in almost 86%, always 69.23%; 58 mutilated young women reported orgasm in 91.43%, always 8.57%; after defibulation 14 out of 15 infibulated women reported orgasm; the group of 57 infibulated women investigated with the FSFI questionnaire showed significant differences between group of study and an equivalent group of control in desire, arousal, orgasm, and satisfaction with mean scores higher in the group of mutilated women. No significant differences were observed between the two groups in lubrication and pain. Embryology, anatomy, and physiology of female erectile organs are neglected in specialist textbooks. In infibulated women, some erectile structures fundamental for orgasm have not been excised. Cultural influence can change the perception of pleasure, as well as social acceptance. Every woman has the right to have sexual health and to feel sexual pleasure for full psychophysical well-being of the person. In accordance with other research, the present study reports that FGM/C women can also have the possibility of reaching an orgasm. Therefore, FGM/C women with sexual dysfunctions can and must be cured; they have the right to have an appropriate sexual therapy.

Timoshenko-Type Theory in the Stability Analysis of Corrugated Cylindrical Shells

NASA Astrophysics Data System (ADS)

Semenyuk, N. P.; Neskhodovskaya, N. A.

2002-06-01

A technique is proposed for stability analysis of longitudinally corrugated shells under axial compression. The technique employs the equations of the Timoshenko-type nonlinear theory of shells. The geometrical parameters of shells are specified on discrete set of points and are approximated by segments of Fourier series. Infinite systems of homogeneous algebraic equations are derived from a variational equation written in displacements to determine the critical loads and buckling modes. Specific types of corrugated isotropic metal and fiberglass shells are considered. The calculated results are compared with those obtained within the framework of the classical theory of shells. It is shown that the Timoshenko-type theory extends significantly the possibility of exact allowance for the geometrical parameters and material properties of corrugated shells compared with Kirchhoff-Love theory.

Buckling and Failure of Compression-Loaded Composite Laminated Shells With Cutouts

NASA Technical Reports Server (NTRS)

Hilburger, Mark W.

2007-01-01

Results from a numerical and experimental study that illustrate the effects of laminate orthotropy on the buckling and failure response of compression-loaded composite cylindrical shells with a cutout are presented. The effects of orthotropy on the overall response of compression-loaded shells is described. In general, preliminary numerical results appear to accurately predict the buckling and failure characteristics of the shell considered herein. In particular, some of the shells exhibit stable post-local-buckling behavior accompanied by interlaminar material failures near the free edges of the cutout. In contrast another shell with a different laminate stacking sequence appears to exhibit catastrophic interlaminar material failure at the onset of local buckling near the cutout and this behavior correlates well with corresponding experimental results.

HOTCFGM-2D: A Coupled Higher-Order Theory for Cylindrical Structural Components with Bi-Directionally Components with Bi-Directionally Graded Microstructures

NASA Technical Reports Server (NTRS)

Pindera, Marek-Jerzy; Aboudi, Jacob

2000-01-01

The objective of this two-year project was to develop and deliver to the NASA-Glenn Research Center a two-dimensional higher-order theory, and related computer codes, for the analysis and design of cylindrical functionally graded materials/structural components for use in advanced aircraft engines (e.g., combustor linings, rotor disks, heat shields, brisk blades). To satisfy this objective, two-dimensional version of the higher-order theory, HOTCFGM-2D, and four computer codes based on this theory, for the analysis and design of structural components functionally graded in the radial and circumferential directions were developed in the cylindrical coordinate system r-Theta-z. This version of the higher-order theory is a significant generalization of the one-dimensional theory, HOTCFGM-1D, developed during the FY97 for the analysis and design of cylindrical structural components with radially graded microstructures. The generalized theory is applicable to thin multi-phased composite shells/cylinders subjected to steady-state thermomechanical, transient thermal and inertial loading applied uniformly along the axial direction such that the overall deformation is characterized by a constant average axial strain. The reinforcement phases are uniformly distributed in the axial direction, and arbitrarily distributed in the radial and circumferential direction, thereby allowing functional grading of the internal reinforcement in the r-Theta plane. The four computer codes fgmc3dq.cylindrical.f, fgmp3dq.cylindrical.f, fgmgvips3dq.cylindrical.f, and fgmc3dq.cylindrical.transient.f are research-oriented codes for investigating the effect of functionally graded architectures, as well as the properties of the multi-phase reinforcement, in thin shells subjected to thermomechanical and inertial loading, on the internal temperature, stress and (inelastic) strain fields. The reinforcement distribution in the radial and circumferential directions is specified by the user. The thermal and inelastic properties of the individual phases can vary with temperature. The inelastic phases are presently modeled by the power-law creep model generalized to multi-directional loading (within fgmc3dq.cylindrical.f and fgmc3dq.cylindrical.transient.f for steady-state and transient thermal loading, respectively), and incremental plasticity and GVIPS unified viscoplasticity theories (within the steady-state loading versions fgmp3dq.cylindrical.f and fgmgvips3dq.cylindrical.f).

Analysis of thermoelastic characteristics in a thick walled FGM cylinder

NASA Astrophysics Data System (ADS)

Tanvir, A. N. M.; Islam, Md. Didarul; Ahmed, Faisal

2017-12-01

This study is concerned with the behavior of stress and strain in a thick walled functionally graded material (FGM) cylinder under internal pressure. The incompatible eigenstrain and equivalent eigenstrain developed in the cylinder, are taken into account. As a demonstration, a TiC/Al2O3 FGM cylinder is considered and different components of stress and strain are presented in order to study the effects of internal pressure, temperature difference (between room and sintering temperature), cylinder wall thickness and material distribution. The numerical result presented here shows that the thermoelastic characteristic like stress and strain of an FGM cylinder is significantly influenced by some of the above-mentioned parameters and can be controlled by properly controlling these parameters.

Resonant responses and chaotic dynamics of composite laminated circular cylindrical shell with membranes

NASA Astrophysics Data System (ADS)

Zhang, W.; Liu, T.; Xi, A.; Wang, Y. N.

2018-06-01

This paper is focused on the resonant responses and chaotic dynamics of a composite laminated circular cylindrical shell with radially pre-stretched membranes at both ends and clamped along a generatrix. Based on the two-degree-of-freedom non-autonomous nonlinear equations of this system, the method of multiple scales is employed to obtain the four-dimensional nonlinear averaged equation. The resonant case considered here is the primary parametric resonance-1/2 subharmonic resonance and 1:1 internal resonance. Corresponding to several selected parameters, the frequency-response curves are obtained. From the numerical results, we find that the hardening-spring-type behaviors and jump phenomena are exhibited. The jump phenomena also occur in the amplitude curves of the temperature parameter excitation. Moreover, it is found that the temperature parameter excitation, the coupling degree of two order modes and the detuning parameters can effect the nonlinear oscillations of this system. The periodic and chaotic motions of the composite laminated circular cylindrical shell clamped along a generatrix are demonstrated by the bifurcation diagrams, the maximum Lyapunov exponents, the phase portraits, the waveforms, the power spectrums and the Poincaré map. The temperature parameter excitation shows that the Pomeau-Manneville type intermittent chaos occur under the certain initial conditions. It is also found that there exist the twin phenomena between the Pomeau-Manneville type intermittent chaos and the period-doubling bifurcation.

Acoustic resonance scattering from a multilayered cylindrical shell with imperfect bonding.

PubMed

Rajabi, M; Hasheminejad, Seyyed M

2009-12-01

The method of wave function expansion is adopted to study the three dimensional scattering of a time-harmonic plane progressive sound field obliquely incident upon a multi-layered hollow cylinder with interlaminar bonding imperfection. For the generality of solution, each layer is assumed to be cylindrically orthotropic. An approximate laminate model in the context of the modal state equations with variable coefficients along with the classical T-matrix solution technique is set up for each layer to solve for the unknown modal scattering and transmission coefficients. A linear spring model is used to describe the interlaminar adhesive bonding whose effects are incorporated into the global transfer matrix by introduction of proper interfacial transfer matrices. Following the classic acoustic resonance scattering theory (RST), the scattered field and response to surface waves are determined by constructing the partial waves and obtaining the non-resonance (backgrounds) and resonance components. The solution is first used to investigate the effect of interlayer imperfection of an air-filled and water submerged bilaminate aluminium cylindrical shell on the resonances associated with various modes of wave propagation (i.e., symmetric/asymmetric Lamb waves, fluid-borne A-type waves, Rayleigh and Whispering Gallery waves) appearing in the backscattered spectrum, according to their polarization and state of stress. An illustrative numerical example is also given for a multi-layered (five-layered) cylindrical shell for which the stiffness of the adhesive interlayers is artificially varied. The sensitivity of resonance frequencies associated with higher mode numbers to the stiffness coefficients is demonstrated to be a good measure of the bonding strength. Limiting cases are considered and fair agreements with solutions available in the literature are established.

Pathologies of van Stockum dust/Tipler's time machine

NASA Astrophysics Data System (ADS)

Lindsay, David S.

2016-09-01

We study the internal solution, and external vacuum solution for radial cutoff, of "van Stockum dust", an infinitely long rotating pressureless dust column; its density increases with radius. This interesting but poorly explored spacetime turns out to have a number of exotic properties, especially in the external vacuum region. These solutions have been known for decades, but it seems that they have never been investigated in detail. In this paper we analyze them and describe their peculiar properties. There are three regimes of radial cutoff that are of interest: (1) If the dust column is thick enough that closed timelike loops (CTLs or "time machines") exist inside the column, then the radius of the entire "universe" is finite, and in fact does not extend much beyond the edge of the matter, even though the metric's radial parameter is unbounded. This interesting finite proper radius seems to have been missed by earlier investigators. Other exotic properties of the external vacuum in this regime: CTLs exist in cylindrical shells, alternating with shells having no circular CTLs; there are infinitely many such shells, getting closer and closer together as one gets farther from the rotation axis. Also, a separate set of infinitely many cylindrical shells exists, having what might be termed "extreme frame-dragging", within which motion is possible only in one direction; they alternate with "normal" shells allowing motion in either direction. Gravitational attraction and tides increase with distance from the matter column, and diverge at the "edge of the universe". In addition, though the radius of the universe is finite, its circumference is infinite; and its boundary is a circle, not a cylinder (the z-axis has shrunk to nothing at the edge). (2) For smaller radial cutoff, but still large enough to produce CTLs, the radius of the universe is infinite; but there are still infinitely many cylindrical shells of CTLs alternating with non-CTL shells. However, the innermost shell begins substantially outside the dust, making this solution even stranger—you have to back away from the matter to find a CTL! And, regardless of how far away you are, there are still infinitely many CTL shells beyond you, the closest only a finite distance away. (3) For radial cutoff too close to produce CTLs, the external solution is more benign; nearby it perhaps approximates that of a finite rotating rod. But "planes" of constant z approach each other at large radii, so that any two enclose a shape somewhat like two pie-pans facing each other and glued together at their edges.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Xiangfeng; Tanihata, Kimiaki; Miyamoto, Yoshinari

A TiC/Ni functionally gradient material (FGM) fabricated via gas-pressure combustion sintering is presently investigated to establish its mechanical and thermal properties. Attention is given to the FGM's specific thermal conductivities with different thermal cycling conditions; these are found to decrease with thermal cycling in all samples tested, implying that the lateral cracks are generated in the FGM and then propagated by the thermal cycle. High compressive stresses are induced at the TiC surface when this is constrained by a Cu block. 6 refs.

Female Genital Mutilation Reconstruction: A Preliminary Report.

PubMed

Chang, Catherine S; Low, David W; Percec, Ivona

2017-09-01

Female genital mutilation (FGM) is internationally recognized as a violation of human rights. Though rarely discussed, FGM is prevalent, affecting hundreds of millions of females worldwide. We believe that is important for plastic surgeons to be informed and prepared to address the surgical and emotional needs of these women. We present our experience on treatment of women subjected to FGM. Three consecutive patients were treated by our clitoral restoration procedure. The procedure involves conscious sedation and involves wide release of scar tissue around the labia majora and clitoris. Labial flaps are elevated and secured down to the periosteum and the clitoris is allowed to remucosalize. Three females with grade II mutilation were treated. The average age was 32.3-years-old and the average follow up was 305 days. All patients self-reported improved sexual function and decreased embarrassment with their partners. And all recommended the treatment to other women subjected to FGM. FGM is a violation of the basic rights of women and children. Plastic surgeons can help these women restore their physical and psychological sense of well-being by providing effective reconstructive options. Our goal is to raise awareness of this problem and describe a simple yet effective treatment for women that have been subject to FGM. 5. © 2017 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com

Cognitive behavioral therapy for post-traumatic stress disorder, depression, or anxiety disorders in women and girls living with female genital mutilation: A systematic review.

PubMed

Adelufosi, Adegoke; Edet, Bassey; Arikpo, Dachi; Aquaisua, Ememobong; Meremikwu, Martin M

2017-02-01

Female genital mutilation (FGM) is associated with psychological consequences such as post-traumatic stress disorder (PSTD), depression, and anxiety disorders. Cognitive behavioral therapy (CBT), an empirically supported form of psychotherapy, may be an effective treatment for these psychological sequelae of FGM. To assess the effectiveness of CBT among individuals living with any type of FGM and diagnosed to have PTSD, depression, or anxiety disorders. CENTRAL, Medline, African Index Medicus, SCOPUS, PILOTS, POPLINE, PsycINFO, WHOLIS, LILACS, ERIC, NYAM Library, CINAHL, Web of Science were searched from inception up to August 10, 2015. Both randomized and nonrandomized studies comparing the efficacy of CBT to other forms of interventions for PTSD, depression, or anxiety disorders in individuals with FGM, were systematically reviewed. We did not identify any studies with eligible design that addressed the objective of the review. There are no included studies. Future studies need to look beyond establishing the prevalence and correlates of FGM to conducting well-designed, randomized controlled studies or well-designed interventional observational studies for the management of the psychological consequences of women and girls living with FGM. CRD42015024458. © 2017 International Federation of Gynecology and Obstetrics. The World Health Organization retains copyright and all other rights in the manuscript of this article as submitted for publication.

Providing information to improve body image and care-seeking behavior of women and girls living with female genital mutilation: A systematic review and meta-analysis.

PubMed

Esu, Ekpereonne; Okoye, Ifeyinwa; Arikpo, Iwara; Ejemot-Nwadiaro, Regina; Meremikwu, Martin M

2017-02-01

Female genital mutilation (FGM) has become recognized worldwide as an extreme form of violation of the human rights of girls and women. Strategies have been employed to curb the practice. To conduct a systematic review of randomized and nonrandomized studies of the effects of providing educational interventions on the body image and care-seeking behavior of girls and women living with FGM with the view to ending the practice. CENTRAL, MEDLINE, and other databases were searched up to August 10, 2015 without any language restrictions. Studies that provided education to women and/or girls living with any type of FGM or residing in countries where FGM is predominantly practiced were included. Two authors independently screened and collected data. We summarized dichotomous outcomes using odds ratios and evidence was assessed using the GRADE system (Grading of Recommendations Assessment, Development, and Evaluation). Educational interventions resulted in fewer women recommending FGM for their daughters and also reduced the incidence of FGM cases among daughters of women who received the educational interventions. These findings need to be validated with large randomized trials. 42015024637. © 2017 International Federation of Gynecology and Obstetrics. The World Health Organization retains copyright and all other rights in the manuscript of this article as submitted for publication.

Health information interventions for female genital mutilation.

PubMed

Smith, Helen; Stein, Karin

2017-02-01

Providing information and education to women and girls living with female genital mutilation (FGM) could be an important influence on their healthcare-seeking behavior. Healthcare providers also need adequate knowledge and skills to provide good quality care to this population. Recent WHO guidelines on managing health complications from FGM contain best practice statements for health education and information interventions for women and providers. This qualitative evidence synthesis summarizes the values and preferences of girls and women living with FGM, and healthcare providers, together with other evidence on the context and conditions of these interventions. The synthesis highlights that healthcare providers lack skills and training to manage women, and women are concerned about the lack of discussion about FGM with providers. There is a need for more training for providers, and further research to understand how health information interventions may be perceived or experienced by women living with FGM in different contexts. © 2017 International Federation of Gynecology and Obstetrics. The World Health Organization retains copyright and all other rights in the manuscript of this article as submitted for publication.

Supportive psychotherapy or client education alongside surgical procedures to correct complications of female genital mutilation: A systematic review.

PubMed

Abayomi, Olukayode; Chibuzor, Moriam T; Okusanya, Babasola O; Esu, Ekpereonne; Odey, Edward; Meremikwu, Martin M

2017-02-01

Supportive psychotherapy, in individual or group settings, may help improve surgical outcomes for women and girls living with female genital mutilation (FGM). To assess whether supportive psychotherapy given alongside surgical procedures to correct complications of FGM improves clinical outcomes. We searched major databases including CENTRAL, Medline, African Index Medicus, SCOPUS, PsycINFO, and others. There were no language restrictions. We checked the reference lists of retrieved studies for additional reports of relevant studies. We included studies of girls and women living with any type of FGM who received supportive psychotherapy or client education sessions alongside any surgical procedure to correct health complications from FGM. Two team members independently screened studies for eligibility. There were no eligible studies identified. There is no direct evidence for the benefits or harms of supportive psychotherapy alongside surgical procedures for women and girls living with FGM. Research evidence is urgently needed to guide clinical practice. 42015024639. © 2017 International Federation of Gynecology and Obstetrics. The World Health Organization retains copyright and all other rights in the manuscript of this article as submitted for publication.

Female Genital Mutilation Is a Violation of Reproductive Rights of Women: Implications for Health Workers.

PubMed

Jungari, Suresh Banayya

2016-02-01

Female genital mutilation (FGM) comprises all procedures that involve partial or total removal of the external female genitalia or other injury to the female genital organs for nonmedical reasons. This coercive practice is still prevalent in many parts of the world, in both developed and developing countries. However, FGM is more prevalent in African countries and some Asian countries. In this study, an attempt has been made to understand the prevalence and practice of FGM worldwide and its adverse effects on women's reproductive health. To fulfill the study objectives, the author collected evidence from various studies conducted by international agencies. Many studies found that FGM has no health benefits; is mostly carried out on girls before they reach the age of 15 years; can cause severe bleeding, infections, psychological illness, and infertility; and, most important, can have serious consequences during childbirth. The practice is mainly governed by the traditions and cultures of the communities without having any scientific or medical benefit. In conclusion, FGM is a practice that violates the human and reproductive rights of women.

Design Optimization and Residual Strength Assessment of a Cylindrical Composite Shell Structure

NASA Technical Reports Server (NTRS)

Rais-Rohani, Masoud

2000-01-01

A summary of research conducted during the specified period is presented. The research objectives included the investigation of an efficient technique for the design optimization and residual strength assessment of a semi-monocoque cylindrical shell structure made of composite materials. The response surface methodology is used in modeling the buckling response of individual skin panels under the combined axial compression and shear loading. These models are inserted into the MSC/NASTRAN code for design optimization of the cylindrical structure under a combined bending-torsion loading condition. The comparison between the monolithic and sandwich skin design cases indicated a 35% weight saving in using sandwich skin panels. In addition, the residual strength of the optimum design was obtained by identifying the most critical region of the structure and introducing a damage in the form of skin-stringer and skin-stringer-frame detachment. The comparison between the two skin design concepts indicated that the sandwich skin design is capable of retaining a higher residual strength than its monolithic counterpart. The results of this investigation are presented and discussed in this report.

Thermocryogenic buckling and stress analyses of a partially filled cryogenic tank subjected to cylindrical strip heating

NASA Technical Reports Server (NTRS)

Ko, William L.

1994-01-01

Thermocryogenic buckling and stress analyses were conducted on a horizontally oriented cryogenic tank using the finite element method. The tank is a finite-length circular cylindrical shell with its two ends capped with hemispherical shells. The tank is subjected to cylindrical strip heating in the region above the liquid-cryogen fill level and to cryogenic cooling below the fill level (i.e., under thermocryogenic loading). The effects of cryogen fill level on the buckling temperature and thermocryogenic stress field were investigated in detail. Both the buckling temperature and stress magnitudes were relatively insensitive to the cryogen fill level. The buckling temperature, however, was quite sensitive to the radius-to-thickness ratio. A mechanical stress analysis of the tank also was conducted when the tank was under: (1) cryogen liquid pressure loading; (2) internal pressure loading; and (3) tank-wall inertia loading. Deformed shapes of the cryogenic tanks under different loading conditions were shown, and high-stress domains were mapped on the tank wall for the strain-gage installations. The accuracies of solutions from different finite element models were compared.

Sonar Imaging of Elastic Fluid-Filled Cylindrical Shells.

NASA Astrophysics Data System (ADS)

Dodd, Stirling Scott

1995-01-01

Previously a method of describing spherical acoustic waves in cylindrical coordinates was applied to the problem of point source scattering by an elastic infinite fluid -filled cylindrical shell (S. Dodd and C. Loeffler, J. Acoust. Soc. Am. 97, 3284(A) (1995)). This method is applied to numerically model monostatic oblique incidence scattering from a truncated cylinder by a narrow-beam high-frequency imaging sonar. The narrow beam solution results from integrating the point source solution over the spatial extent of a line source and line receiver. The cylinder truncation is treated by the method of images, and assumes that the reflection coefficient at the truncation is unity. The scattering form functions, calculated using this method, are applied as filters to a narrow bandwidth, high ka pulse to find the time domain scattering response. The time domain pulses are further processed and displayed in the form of a sonar image. These images compare favorably to experimentally obtained images (G. Kaduchak and C. Loeffler, J. Acoust. Soc. Am. 97, 3289(A) (1995)). The impact of the s_{ rm o} and a_{rm o} Lamb waves is vividly apparent in the images.

Fracture mechanics analyses of partial crack closure in shell structures

NASA Astrophysics Data System (ADS)

Zhao, Jun

2007-12-01

This thesis presents the theoretical and finite element analyses of crack-face closure behavior in shells and its effect on the stress intensity factor under a bending load condition. Various shell geometries, such as spherical shell, cylindrical shell containing an axial crack, cylindrical shell containing a circumferential crack and shell with double curvatures, are all studied. In addition, the influence of material orthotropy on the crack closure effect in shells is also considered. The theoretical formulation is developed based on the shallow shell theory of Delale and Erdogan, incorporating the effect of crack-face closure at the compressive edges. The line-contact assumption, simulating the crack-face closure at the compressive edges, is employed so that the contact force at the closure edges is introduced, which can be translated to the mid-plane of the shell, accompanied by an additional distributed bending moment. The unknown contact force is computed by solving a mixed-boundary value problem iteratively, that is, along the crack length, either the normal displacement of the crack face at the compressive edges is equal to zero or the contact pressure is equal to zero. It is found that due to the curvature effects crack closure may not always occur on the entire length of the crack, depending on the direction of the bending load and the geometry of the shell. The crack-face closure influences significantly the magnitude of the stress intensity factors; it increases the membrane component but decreases the bending component. The maximum stress intensity factor is reduced by the crack-face closure. The significant influence of geometry and material orthotropy on rack closure behavior in shells is also predicted based on the analytical solutions. Three-dimensional FEA is performed to validate the theoretical solutions. It demonstrates that the crack face closure occurs actually over an area, not on a line, but the theoretical solutions of the stress intensity factor and the FEA solutions are in good agreement, because the contact area is very small compared with the shell thickness.

Protecting girls and women from harmful practices affecting their health: Are we making progress?

PubMed

Cottingham, Jane; Kismodi, Eszter

2009-08-01

Since female genital mutilation (FGM) was first recognized internationally in 1958, it has now become widely accepted and anchored in international law that FGM is a violation of girls' and women's human rights. Declines in the practice, however, are slow overall, and continued work for its elimination requires action and investment at many levels. Where the practice has diminished, community action has been widespread and sustained. Governments, who are ultimately responsible for the eradication of FGM, must take many measures to outlaw the practice and protect girls' and women's rights, through legislation, policy, education, and resource allocation. Among the other key actors, health care professionals have a particularly important role in treating women and in preventing FGM by actively opposing any medicalization of the practice.

Suction muffler for refrigeration compressor

DOEpatents

Nelson, R.T.; Middleton, M.G.

1983-01-25

A hermetic refrigeration compressor includes a suction muffler formed from two pieces of plastic material mounted on the cylinder housing. One piece is cylindrical in shape with an end wall having an aperture for receiving a suction tube connected to the cylinder head. The other piece fits over and covers the other end of the cylindrical piece, and includes a flaring entrance horn which extends toward the return line on the sidewall of the compressor shell. 5 figs.

Suction muffler for refrigeration compressor

DOEpatents

Nelson, Richard T.; Middleton, Marc G.

1983-01-01

A hermetic refrigeration compressor includes a suction muffler formed from two pieces of plastic material mounted on the cylinder housing. One piece is cylindrical in shape with an end wall having an aperture for receiving a suction tube connected to the cylinder head. The other piece fits over and covers the other end of the cylindrical piece, and includes a flaring entrance horn which extends toward the return line on the sidewall of the compressor shell.

A collection of edge-based elements

NASA Technical Reports Server (NTRS)

Kempel, Leo C.; Volakis, John L.

1992-01-01

Edge-based elements have proved useful in solving electromagnetic problems since they are nondivergent. Previous authors have presented several two and three dimensional elements. Herein, we present four types of elements which are suitable for modeling several types of three dimensional geometries. Distorted brick and triangular prism elements are given in cartesian coordinates as well as the specialized cylindrical shell and pie-shaped prism elements which are suitable for problems best described in polar cylindrical coordinates.

GRIPPING DEVICE FOR CYLINDRICAL OBJECTS

DOEpatents

Pilger, J.P.

1964-01-21

A gripping device is designed for fragile cylindrical objects such as for drawing thin-walled tubes. The gripping is done by multiple jaw members held in position by two sets of slots, one defined by keystone-shaped extensions of the outer shell of the device and the other in a movable sleeve held slidably by the extensions. Forward movement oi the sleeve advances the jaws, thereby exerting a controlled, radial pressure on the object being gripped. (AEC)

Female Genital Mutilation

MedlinePlus

... of being rejected by the community, are strong motivations to perpetuate the practice. In some communities, FGM ... of being rejected by the community, are strong motivations to perpetuate the practice. In some communities, FGM ...

Female genital mutilation: when a cultural practice generates clinical and ethical dilemmas.

PubMed

Gibeau, A M

1998-01-01

Female genital mutilation (FGM) is of growing concern to health care providers in the United States and Canada as more women from countries where the procedure is practiced emigrate to North America. An introduction to the demographics of FGM, including prevalence rates, is a necessary antecedent for understanding the cultural rationales for this widespread practice. Considering the health consequences of this practice promotes questions about legal and ethical aspects of care as North Americans approach FGM from their own individual cultural frameworks.

Female Genital Mutilation: perceptions of healthcare professionals and the perspective of the migrant families

PubMed Central

2010-01-01

Background Female Genital Mutilation (FGM) is a traditional practice which is harmful to health and is profoundly rooted in many Sub-Saharan African countries. It is estimated that between 100 and 140 million women around the world have been victims of some form of FGM and that each year 3 million girls are at risk of being submitted to these practices. As a consequence of the migratory phenomena, the problems associated with FGM have extended to the Western countries receiving the immigrants. The practice of FGM has repercussions on the physical, psychic, sexual and reproductive health of women, severely deteriorating their current and future quality of life. Primary healthcare professionals are in a privileged position to detect and prevent these situations of risk which will be increasingly more present in Spain. Methods/Design The objective of the study is to describe the knowledge, attitudes and practices of the primary healthcare professionals, working in 25 health care centres in Barcelona and Girona regions, regarding FGM, as well as to investigate the perception of this subject among the migrant communities from countries with strong roots in these practices. A transversal descriptive study will be performed with a questionnaire to primary healthcare professionals and migrant healthcare users. Using a questionnaire specifically designed for this study, we will evaluate the knowledge, attitudes and skills of the healthcare professionals to approach this problem. In a sub-study, performed with a similar methodology but with the participation of cultural mediators, the perceptions of the migrant families in relation to their position and expectancies in view of the result of preventive interventions will be determined. Variables related to the socio-demographic aspects, knowledge of FGM (types, cultural origin, geographic distribution and ethnicity), evaluation of attitudes and beliefs towards FGM and previous contact or experience with cases or risk situations will be obtained. Discussion Knowledge of these harmful practices and a preventive approach from a transcultural perspective may represent a positive intervention model for integrative care of immigrants, respecting their values and culture while also being effective in eliminating the physical and psychic consequences of FGM. PMID:20388216

Knowledge, attitudes and practices of female genital mutilation/cutting among health care professionals in The Gambia: a multiethnic study.

PubMed

Kaplan, Adriana; Hechavarría, Suiberto; Bernal, Mariola; Bonhoure, Isabelle

2013-09-16

Female genital mutilation/cutting (FGM/C) is a harmful traditional practice with severe consequences for the health and well-being of girls and women. Health care professionals (HCPs) are therefore expected to be aware of how to identify and manage these consequences in order to ensure that those affected by the practice receive quality health care. Moreover, their integration and legitimacy within the communities allow them to play a key role in the prevention of the practice. Nevertheless, the perception of HCPs on FGM/C has been barely explored in African contexts. This study seeks to contribute to this field of knowledge by examining the knowledge, attitudes, and practices regarding FGM/C among HCPs working in rural settings in The Gambia. A cross-sectional descriptive study was designed through a quantitative methodology, following a multiethnic approach. A pre-tested questionnaire with open and closed-ended questions was created. Forty medical students from the Community-based Medical Programme were trained to administer the questionnaire, face to face, at village health facilities in rural areas of The Gambia. A final sample of 468 HCPs included all nurse cadres and midwives. A significant proportion of Gambian HCPs working in rural areas embraced the continuation of FGM/C (42.5%), intended to subject their own daughters to it (47.2%), and reported having already performed it during their medical practice (7.6%). However, their knowledge, attitudes, and practices were shaped by sex and ethnic identity. Women showed less approval for continuation of FGM/C and higher endorsement of the proposed strategies to prevent it than men. However, it was among ethnic groups that differences were more substantial. HCPs belonging to traditionally practicing groups were more favourable to the perpetuation and medicalisation of FGM/C, suggesting that ethnicity prevails over professional identity. These findings demonstrate an urgent need to build HCP's capacities for FGM/C-related complications, through strategies adapted to their specific characteristics in terms of sex and ethnicity. A culturally and gender sensitive training programme might contribute to social change, promoting the abandonment of FGM/C, avoiding medicalisation, and ensuring accurate management of its health consequences.

Sound radiation from an infinite elastic cylinder with dual-wave propagation-intensity distributions

NASA Technical Reports Server (NTRS)

Fuller, C. R.

1988-01-01

The radiation of sound from an elastic cylindrical shell filled with fluid and supporting multiwave propagation is studied analytically. Combinations of supersonic and subsonic shell waves are considered. The radiated field is mapped by using acoustic intensity vectors evaluated at various locations. Both time averaged and instantaneous intensity are investigated. The acoustic intensity is seen to vary markedly with axial distance down the cylinder. The effect is shown to be associated with cross terms in the intensity relations, and its magnitude and location to depend upon the relative phase and amplitudes of individual waves. Subsonic shell waves are demonstrated to interact strongly with supersonic shell waves to cause a large modification in the radiated intensity distributions near the shell surface.

Motion through a non-homogeneous porous medium: Hydrodynamic permeability of a membrane composed of cylindrical particles

NASA Astrophysics Data System (ADS)

Yadav, Pramod Kumar

2018-01-01

The present problem is concerned with the flow of a viscous steady incompressible fluid through a non-homogeneous porous medium. Here, the non-homogeneous porous medium is a membrane built up by cylindrical particles. The flow outside the membrane is governed by the Stokes equation and the flow through the non-homogeneous porous membrane composed by cylindrical particles is governed by Darcy's law. In this work, we discussed the effect of various fluid parameters like permeability parameter k0, discontinuity coefficient at fluid-non homogeneous porous interface, viscosity ratio of viscous incompressible fluid region and non-homogeneous porous region, etc. on hydrodynamic permeability of a membrane, stress and on velocity profile. The comparative study for hydrodynamic permeability of membrane built up by non-homogeneous porous cylindrical particles and porous cylindrical shell enclosing a cylindrical cavity has been studied. The effects of various fluid parameters on the streamlines flow patterns are also discussed.

Bottom head to shell junction assembly for a boiling water nuclear reactor

DOEpatents

Fife, Alex Blair; Ballas, Gary J.

1998-01-01

A bottom head to shell junction assembly which, in one embodiment, includes an annular forging having an integrally formed pump deck and shroud support is described. In the one embodiment, the annular forging also includes a top, cylindrical shaped end configured to be welded to one end of the pressure vessel cylindrical shell and a bottom, conical shaped end configured to be welded to the disk shaped bottom head. Reactor internal pump nozzles also are integrally formed in the annular forging. The nozzles do not include any internal or external projections. Stubs are formed in each nozzle opening to facilitate welding a pump housing to the forging. Also, an upper portion of each nozzle opening is configured to receive a portion of a diffuser coupled to a pump shaft which extends through the nozzle opening. Diffuser openings are formed in the integral pump deck to provide additional support for the pump impellers. The diffuser opening is sized so that a pump impeller can extend at least partially therethrough. The pump impeller is connected to the pump shaft which extends through the nozzle opening.

Bottom head to shell junction assembly for a boiling water nuclear reactor

DOEpatents

Fife, A.B.; Ballas, G.J.

1998-02-24

A bottom head to shell junction assembly which, in one embodiment, includes an annular forging having an integrally formed pump deck and shroud support is described. In the one embodiment, the annular forging also includes a top, cylindrical shaped end configured to be welded to one end of the pressure vessel cylindrical shell and a bottom, conical shaped end configured to be welded to the disk shaped bottom head. Reactor internal pump nozzles also are integrally formed in the annular forging. The nozzles do not include any internal or external projections. Stubs are formed in each nozzle opening to facilitate welding a pump housing to the forging. Also, an upper portion of each nozzle opening is configured to receive a portion of a diffuser coupled to a pump shaft which extends through the nozzle opening. Diffuser openings are formed in the integral pump deck to provide additional support for the pump impellers. The diffuser opening is sized so that a pump impeller can extend at least partially therethrough. The pump impeller is connected to the pump shaft which extends through the nozzle opening. 5 figs.

Resonant Vibrations and Vibrational Heating of Physically Nonlinear Viscoelastic Shells and Their Damping Using Piezoelectric Sensor and Actuator

NASA Astrophysics Data System (ADS)

Kirichok, I. F.

2017-09-01

Forced axisymmetric resonant vibrations and vibrational heating of viscoelastic, physically nonlinear, closed, spherical, and infinitely long cylindrical shells and ring with piezoelectric sensor and actuator are considered. The effect of physical nonlinearity of passive material on the vibration amplitude and vibrational heating temperature is studied. The possibility of active damping of vibrations by piezoelectric sensors and actuators is demonstrated.

Approximate method for calculating a thickwalled cylinder with rigidly clamped ends

NASA Astrophysics Data System (ADS)

Andreev, Vladimir

2018-03-01

Numerous papers dealing with the calculations of cylindrical bodies [1 -8 and others] have shown that analytic and numerical-analytical solutions in both homogeneous and inhomogeneous thick-walled shells can be obtained quite simply, using expansions in Fourier series on trigonometric functions, if the ends are hinged movable (sliding support). It is much more difficult to solve the problem of calculating shells with builtin ends.

Ring stability of underground toroidal tanks

NASA Astrophysics Data System (ADS)

Lubis, Asnawi; Su'udi, Ahmad

2017-06-01

The design of pressure vessels subjected to internal pressure is governed by its strength, while the design of pressure vessels subjected to external pressure is governed by its stability, which is for circular cross-section is called the ring stability. This paper presented the results of finite element study of ring stability of circular toroidal tank without stiffener under external pressure. The tank was placed underground and external pressure load from soil was simulated as pressure at the top of the vessel along 30° circumferentially. One might ask the reason for choosing toroidal rather than cylindrical tank. Preliminary finite element studies showed that toroidal shells can withstand higher external pressure than cylindrical shells. In this study, the volume of the tank was fixed for 15,000 litters. The buckling external pressure (pL) was calculated for radius ratio (R/r) of 2, 3, and 4. The corresponding cross-section radiuses were 724.3 mm, 632.7 mm, and 574.9 mm, respectively. The selected element type was SHELL 281 from the ANSYS element library. To obtain the buckling load, the arc-length method was used in the nonlinear analysis. Both material and geometric nonlinearities were activated during the analysis. The conclusion of this study is that short-radius and thin-walled toroidal shell produces higher buckling load.

Compensation behaviors and magnetic properties in a cylindrical ferrimagnetic nanotube with core-shell structure: A Monte Carlo study

NASA Astrophysics Data System (ADS)

Wang, Wei; Liu, Ying; Gao, Zhong-yue; Zhao, Xue-ru; Yang, Yi; Yang, Sen

2018-07-01

Compensation temperature Tcomp and transition temperature TC have significant applications for the experimental realization of magnetic nanotube structure in the field of thermal magnetic recording. In this work, we use the Monte Carlo simulation to investigate the phase diagrams, magnetizations, susceptibilities, internal energies, specific heats and hysteresis behaviors of a cylindrical ferrimagnetic nanotube with core-shell structure. The effects of the single-ion anisotropies (DC, DS) and the exchange couplings (Jint, JS) on the magnetic and thermodynamic properties of the system are examined. A number of characteristic behaviors are discovered in the thermal variations, depending on different physical parameters. In particular, the triple hysteresis loops behavior has been found for appropriate physical parameters. These findings are qualitatively in good agreement with related experimental and the other theoretical results.

Random crystal field effect on the magnetic and hysteresis behaviors of a spin-1 cylindrical nanowire

NASA Astrophysics Data System (ADS)

Zaim, N.; Zaim, A.; Kerouad, M.

2017-02-01

In this work, the magnetic behavior of the cylindrical nanowire, consisting of a ferromagnetic core of spin-1 atoms surrounded by a ferromagnetic shell of spin-1 atoms is studied in the presence of a random crystal field interaction. Based on Metropolis algorithm, the Monte Carlo simulation has been used to investigate the effects of the concentration of the random crystal field p, the crystal field D and the shell exchange interaction Js on the phase diagrams and the hysteresis behavior of the system. Some characteristic behaviors have been found, such as the first and second-order phase transitions joined by tricritical point for appropriate values of the system parameters, triple and isolated critical points can be also found. Depending on the Hamiltonian parameters, single, double and para hysteresis regions are explicitly determined.

Small bending and stretching of sandwich-type shells

NASA Technical Reports Server (NTRS)

Reissner, Eric

1950-01-01

A theory has been developed for small bending and stretching of sandwich-type shells. This theory is an extension of the known theory of homogeneous thin elastic shells. It was found that two effects are important in the present problem, which are not normally of importance in the theory of curved shells: (1) the effect of transverse shear deformation and (2) the effect of transverse normal stress deformation. The first of these two effects has been known to be of importance in the theory of plates and beams. The second effect was found to occur in a manner which is typical for shells and has no counterpart in flat-plate theory. The general results of this report have been applied to the solution of problems concerning flat plates, circular rings, circular cylindrical shells, and spherical shells. In each case numerical examples have been given, illustrating the magnitude of the effects of transverse shear and normal stress deformation.

Nonlinear theory for laminated and thick plates and shells including the effects of transverse shearing

NASA Technical Reports Server (NTRS)

Stein, M.

1985-01-01

Nonlinear strain displacement relations for three-dimensional elasticity are determined in orthogonal curvilinear coordinates. To develop a two-dimensional theory, the displacements are expressed by trigonometric series representation through-the-thickness. The nonlinear strain-displacement relations are expanded into series which contain all first and second degree terms. In the series for the displacements only the first few terms are retained. Insertion of the expansions into the three-dimensional virtual work expression leads to nonlinear equations of equilibrium for laminated and thick plates and shells that include the effects of transverse shearing. Equations of equilibrium and buckling equations are derived for flat plates and cylindrical shells. The shell equations reduce to conventional transverse shearing shell equations when the effects of the trigonometric terms are omitted and to classical shell equations when the trigonometric terms are omitted and the shell is assumed to be thin.

Shell Buckling Design Criteria Based on Manufacturing Imperfection Signatures

NASA Technical Reports Server (NTRS)

Hilburger, Mark W.; Nemeth, Michael P.; Starnes, James H., Jr.

2004-01-01

An analysis-based approach .for developing shell-buckling design criteria for laminated-composite cylindrical shells that accurately accounts for the effects of initial geometric imperfections is presented. With this approach, measured initial geometric imperfection data from six graphite-epoxy shells are used to determine a manufacturing-process-specific imperfection signature for these shells. This imperfection signature is then used as input into nonlinear finite-element analyses. The imperfection signature represents a "first-approximation" mean imperfection shape that is suitable for developing preliminary-design data. Comparisons of test data and analytical results obtained by using several different imperfection shapes are presented for selected shells. Overall, the results indicate that the analysis-based approach presented for developing reliable preliminary-design criteria has the potential to provide improved, less conservative buckling-load estimates, and to reduce the weight and cost of developing buckling-resistant shell structures.

A systematic review of doctors' experiences and needs to support the care of women with female genital mutilation.

PubMed

Dawson, Angela; Homer, Caroline S E; Turkmani, Sabera; Black, Kirsten; Varol, Nesrin

2015-10-01

Female genital mutilation (FGM) involves partial or complete removal of the external female genitalia or other injury for non-therapeutic reasons. Little is known about the knowledge and skills of doctors who care for affected women and their practice in relation to FGM. To examine the FGM experiences and educational needs of doctors. A structured search of five bibliographic databases was undertaken to identify peer-reviewed research literature published in English between 2004 and 2014 using the keywords "female genital mutilation," "medical," "doctors," "education," and "training." Observational, quasi-experimental, and non-experimental descriptive studies were suitable for inclusion. A narrative synthesis of the study findings was undertaken and themes were identified. Ten papers were included in the review, three of which were from low-income countries. The analysis identified three themes: knowledge and attitudes, FGM-related medical practices, and education and training. There is a need for improved education and training to build knowledge and skills, and to change attitudes concerning the medicalization of FGM and reinfibulation. Copyright © 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Female genital mutilation/cutting in Africa.

PubMed

Odukogbe, Akin-Tunde A; Afolabi, Bosede B; Bello, Oluwasomidoyin O; Adeyanju, Ayodeji S

2017-04-01

Female genital mutilation/cutting (FGM/C) is a traditional practice in which the external female genitalia is partially or totally incised or excised for a non-therapeutic reason, usually without the consent of the individual. FGM/C is common in Africa with varying prevalence in different countries, though the incidence is reducing because it is considered a human rights issue with tremendous advocacy for its elimination by mainly nongovernmental organizations. It is mainly underreported in many countries in Africa especially where it has been declared illegal. FGM/C is often performed by a nonmedical practitioner with the aim of fulfilling religious or cultural rites and sometimes for economic benefits with the resultant acute, intermediate and late complications. It is sometimes performed by medical practitioners when it is speciously believed that its medicalization reduces the complications associated with the practice. The sensitivity of FGM/C is amplified when compared to male circumcision and voluntary alterations of the female external genitalia like piercing and tattooing as similar practices. The magnitude of the physical and psychosocial consequences of FGM/C outweighs the presumed benefits of the procedures highlighting the need for improvement of the multiple preventive measures by all the stakeholders and in all the sectors.

Female genital mutilation/cutting in Africa

PubMed Central

Afolabi, Bosede B.; Bello, Oluwasomidoyin O.; Adeyanju, Ayodeji S.

2017-01-01

Female genital mutilation/cutting (FGM/C) is a traditional practice in which the external female genitalia is partially or totally incised or excised for a non-therapeutic reason, usually without the consent of the individual. FGM/C is common in Africa with varying prevalence in different countries, though the incidence is reducing because it is considered a human rights issue with tremendous advocacy for its elimination by mainly nongovernmental organizations. It is mainly underreported in many countries in Africa especially where it has been declared illegal. FGM/C is often performed by a nonmedical practitioner with the aim of fulfilling religious or cultural rites and sometimes for economic benefits with the resultant acute, intermediate and late complications. It is sometimes performed by medical practitioners when it is speciously believed that its medicalization reduces the complications associated with the practice. The sensitivity of FGM/C is amplified when compared to male circumcision and voluntary alterations of the female external genitalia like piercing and tattooing as similar practices. The magnitude of the physical and psychosocial consequences of FGM/C outweighs the presumed benefits of the procedures highlighting the need for improvement of the multiple preventive measures by all the stakeholders and in all the sectors. PMID:28540220

Maternal Behavior and Physiological Stress Levels in Wild Chimpanzees (Pan troglodytes schweinfurthii).

PubMed

Stanton, Margaret A; Heintz, Matthew R; Lonsdorf, Elizabeth V; Santymire, Rachel M; Lipende, Iddi; Murray, Carson M

2015-06-01

Individual differences in maternal behavior toward, and investment in, offspring can have lasting consequences, particularly among primate taxa characterized by prolonged periods of development over which mothers can exert substantial influence. Given the role of the neuroendocrine system in the expression of behavior, researchers are increasingly interested in understanding the hormonal correlates of maternal behavior. Here, we examined the relationship between maternal behavior and physiological stress levels, as quantified by fecal glucocorticoid metabolite (FGM) concentrations, in lactating chimpanzees, Pan troglodytes schweinfurthii , at Gombe National Park, Tanzania. After accounting for temporal variation in FGM concentrations, we found that mothers interacted socially (groomed and played) with and nursed their infants more on days when FGM concentrations were elevated compared to days when FGM concentrations were within the range expected given the time of year. However, the proportion of time mothers and infants spent in contact did not differ based on FGM concentrations. These results generally agree with the suggestion that elevated GC concentrations are related to maternal motivation and responsivity to infant cues and are the first evidence of a hormonal correlate of maternal behavior in a wild great ape.

Female genital mutilation/cutting: changes and trends in knowledge, attitudes, and practices among health care professionals in The Gambia

PubMed Central

Kaplan Marcusán, Adriana; Riba Singla, Laura; Laye, Mass; Secka, Dodou M; Utzet, Mireia; Le Charles, Marie-Alix

2016-01-01

Background Female genital mutilation/cutting (FGM/C) is a harmful traditional practice that affects two out of three girls in The Gambia, seriously threatening their life and well-being with severe health consequences. By tracking the reference values established in former research conducted between 2009 and 2011, the objectives of this study are to explore trends and to measure and assess changes in knowledge, attitudes, and practices regarding FGM/C among health care professionals (HCPs) in The Gambia. Methods A cross-sectional descriptive study was designed to collect and analyze data from an overall stratified sample consisting of 1,288 HCPs including health professionals and students throughout the six regions of The Gambia. Data were collected by the implementation of a self-administered written knowledge, attitudes, and practices questionnaire between 2012 and 2014. Results The results of this study showed that 76.4% of HCPs are eager to abandon FGM/C, and 71.6% of them regard it as a harmful practice with negative consequences on life and health. HCPs reported more knowledge and favorable attitudes towards FGM/C abandonment, being better able to identify the practice, more aware of its health complications, and more concerned in their essential role as social agents of change. However, 25.4% of HCPs still embraced the continuation of the practice, 24.4% expressed intention of subjecting their own daughters to it, and 10.5% declared to have performed it within their professional praxis. Conclusion Findings confirm progress in knowledge and attitudes regarding FGM/C among HCPs, who are better skilled to understand and manage the consequences. Nevertheless, discrepancies between information, intention, and behavior unveil resistance in practice and proves that FGM/C medicalization is increasing. Thus, there is an urgent need to support HCPs in the integration of FGM/C preventive interventions within the public health system, to address arguments favoring medicalization, and to use data to design appropriate strategies. PMID:27110140

Violence against women.

PubMed

Nelson, T

1996-01-01

This essay opens its discussion of violence against women by referring to the 1994 television broadcast of a 10-year-old Egyptian girl undergoing female genital mutilation (FGM) without benefit of infection control measures or anesthesia at the hands of a local barber. After presenting a brief description of FGM, its various justifications, and its impacts on its victims, the official Egyptian policy is described as ambiguous, and the broadcast is shown to have caused influential religious leaders and medical personnel to defend FGM and, thus, led to postponement of a bill to outlaw FGM. The next section of the essay shows that Egypt's response to FGM reflects the international debate on all forms of violence against women emerging from and reinforcing the social relationships that give men power over women. These forms of violence include domestic violence in almost all societies; the dowry-related, bride-burning homicides that claim 5000-12,000 lives each year in India; son preference that leads to abortion of female fetuses and female infanticide; and crimes such as rape, sexual abuse, and forced prostitution. The essay continues with a look at the costs of violence hidden in the damage to women that increases health care costs substantially and reduces economic productivity. Violence towards women, which occurs throughout the world and can prevent women from participating in public life or from controlling their fertility, is a male tool to inhibit women from gaining autonomy outside the home. The essay concludes that victims of violence are beginning to break the silence that surrounded these deeds and are seeking legislative protection. Laws may not result in real-life changes, but the movement to eliminate FGM may prove to be the first success in women's efforts to achieve human rights. An example is the important precedent being set in the US by a woman seeking asylum to avoid facing an arranged marriage and FGM in her native Togo.

Effects of female genital cutting on physical health outcomes: a systematic review and meta-analysis

PubMed Central

Berg, Rigmor C; Underland, Vigdis; Odgaard-Jensen, Jan; Fretheim, Atle; Vist, Gunn E

2014-01-01

Objective Worldwide, an estimated 125 million girls and women live with female genital mutilation/cutting (FGM/C). We aimed to systematically review the evidence for physical health risks associated with FGM/C. Design We searched 15 databases to identify studies (up to January 2012). Selection criteria were empirical studies reporting physical health outcomes from FGM/C, affecting females with any type of FGM/C, irrespective of ethnicity, nationality and age. Two review authors independently screened titles and abstracts, applied eligibility criteria, assessed methodological study quality and extracted full-text data. To derive overall risk estimates, we combined data from included studies using the Mantel-Haenszel method for unadjusted dichotomous data and the generic inverse-variance method for adjusted data. Outcomes that were sufficiently similar across studies and reasonably resistant to biases were aggregated in meta-analyses. We applied the instrument Grading of Recommendations Assessment, Development and Evaluation to assess the extent to which we have confidence in the effect estimates. Results Our search returned 5109 results, of which 185 studies (3.17 million women) satisfied the inclusion criteria. The risks of systematic and random errors were variable and we focused on key outcomes from the 57 studies with the best available evidence. The most common immediate complications were excessive bleeding, urine retention and genital tissue swelling. The most valid and statistically significant associations for the physical health sequelae of FGM/C were seen on urinary tract infections (unadjusted RR=3.01), bacterial vaginosis (adjusted OR (AOR)=1.68), dyspareunia (RR=1.53), prolonged labour (AOR=1.49), caesarean section (AOR=1.60), and difficult delivery (AOR=1.88). Conclusions While the precise estimation of the frequency and risk of immediate, gynaecological, sexual and obstetric complications is not possible, the results weigh against the continuation of FGM/C and support the diagnosis and management of girls and women suffering the physical risks of FGM/C. Trial registration number This study is registered with PROSPERO, number CRD42012003321. PMID:25416059

Female genital mutilation: the role of medical professional organizations.

PubMed

Bazi, Tony

2017-04-01

Female genital mutilation (FGM) refers to alteration of the external genitalia of girls without medical benefit. It is estimated by United Nations agencies that 200 million living girls and women have been subjected to different forms of FGM worldwide. Despite the criminalization of the procedure in the vast majority of countries where it is practiced, the decline in the incidence of this ritual is far from satisfactory. Immediate and long-term ill effects are well documented. Most publications of relevance originate from countries outside the map of FGM. In addition, there are major gaps in research related to this issue, considering the magnitude of the problem. International medical organizations and societies should assume their responsibility by providing a platform to professionals engaged in the prevention and treatment of the consequences of FGM, especially those living in the communities where the practice is endemic.

Buckling Imperfection Sensitivity of Axially Compressed Orthotropic Cylinders

NASA Technical Reports Server (NTRS)

Schultz, Marc R.; Nemeth, Michael P.

2010-01-01

Structural stability is a major consideration in the design of lightweight shell structures. However, the theoretical predictions of geometrically perfect structures often considerably over predict the buckling loads of inherently imperfect real structures. It is reasonably well understood how the shell geometry affects the imperfection sensitivity of axially compressed cylindrical shells; however, the effects of shell anisotropy on the imperfection sensitivity is less well understood. In the present paper, the development of an analytical model for assessing the imperfection sensitivity of axially compressed orthotropic cylinders is discussed. Results from the analytical model for four shell designs are compared with those from a general-purpose finite-element code, and good qualitative agreement is found. Reasons for discrepancies are discussed, and potential design implications of this line of research are discussed.

LQR Control of Shell Vibrations Via Piezoceramic Actuators

NASA Technical Reports Server (NTRS)

delRosario, R. C. H.; Smith, R. C.

1997-01-01

A model-based Linear Quadratic Regulator (LQR) method for controlling vibrations in cylindrical shells is presented. Surface-mounted piezo-ceramic patches are employed as actuators which leads to unbounded control input operators. Modified Donnell-Mushtari shell equations incorporating strong or Kelvin-Voigt damping are used to model the system. The model is then abstractly formulated in terms of sesquilinear forms. This provides a framework amenable for proving model well-posedness and convergence of LQR gains using analytic semigroup results combined with LQR theory for unbounded input operators. Finally, numerical examples demonstrating the effectiveness of the method are presented.

Female genital mutilation in the Sudan: survey of the attitude of Khartoum university students towards this practice.

PubMed

Herieka, E; Dhar, J

2003-06-01

Female genital mutilation (FGM) or female circumcision is the removal of variable amounts of tissue from the female external genitalia. It is practised all over the world on very young girls. This study was conducted in Sudan where FGM is a criminal offence and not a religious dictate. We assessed the knowledge, attitudes, and perceptions of this practice among Khartoum university students and compared the differences between male and female student responses. An anonymised detailed questionnaire was distributed among the university students. In addition to the participant's age, marital status, course studying, details regarding their attitude, knowledge of the practice of FGM, and their own experiences were collected. Of the 500 questionnaires distributed, 414 (82.8%) were returned from 192 (46%) females and 222 (54%) males. 109 (56.8%) of the female respondents were themselves circumcised.18.8% of the male students and 9.4% of the female students thought FGM was recommended by their religion. Only 90 (46.9%) female students compared with 133 (59.9%) male students thought FGM was illegal. Though 16 (8.3%) female respondents thought FGM would increase their chances of marriage, the majority, 166 (74.8%), of the male students would prefer a non-circumcised female. This study shows that 109 (56.8%) female university students who responded were circumcised. Confusing religious messages and ambiguous laws seem to be responsible for the continuation of this practice. The study highlights the partnership that needs to be established between religious leaders and educationalists to end this medieval practice.

Maternal effects on offspring stress physiology in wild chimpanzees.

PubMed

Murray, Carson M; Stanton, Margaret A; Wellens, Kaitlin R; Santymire, Rachel M; Heintz, Matthew R; Lonsdorf, Elizabeth V

2018-01-01

Early life experiences are known to influence hypothalamic-pituitary-adrenal (HPA) axis development, which can impact health outcomes through the individual's ability to mount appropriate physiological reactions to stressors. In primates, these early experiences are most often mediated through the mother and can include the physiological environment experienced during gestation. Here, we investigate stress physiology of dependent offspring in wild chimpanzees for the first time and examine whether differences in maternal stress physiology are related to differences in offspring stress physiology. Specifically, we explore the relationship between maternal rank and maternal fecal glucocorticoid metabolite (FGM) concentration during pregnancy and early lactation (first 6 months post-partum) and examine whether differences based on maternal rank are associated with dependent offspring FGM concentrations. We found that low-ranking females exhibited significantly higher FGM concentrations during pregnancy than during the first 6 months of lactation. Furthermore, during pregnancy, low-ranking females experienced significantly higher FGM concentrations than high-ranking females. As for dependent offspring, we found that male offspring of low-ranking mothers experienced stronger decreases in FGM concentrations as they aged compared to males with high-ranking mothers or their dependent female counterparts. Together, these results suggest that maternal rank and FGM concentrations experienced during gestation are related to offspring stress physiology and that this relationship is particularly pronounced in males compared to females. Importantly, this study provides the first evidence for maternal effects on the development of offspring HPA function in wild chimpanzees, which likely relates to subsequent health and fitness outcomes. Am. J. Primatol. 80:e22525, 2018. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Gender equality and human rights approaches to female genital mutilation: a review of international human rights norms and standards.

PubMed

Khosla, Rajat; Banerjee, Joya; Chou, Doris; Say, Lale; Fried, Susana T

2017-05-12

Two hundred million girls and women in the world are estimated to have undergone female genital mutilation (FGM), and another 15 million girls are at risk of experiencing it by 2020 in high prevalence countries (UNICEF, 2016. Female genital mutilation/cutting: a global concern. 2016). Despite decades of concerted efforts to eradicate or abandon the practice, and the increased need for clear guidance on the treatment and care of women who have undergone FGM, present efforts have not yet been able to effectively curb the number of women and girls subjected to this practice (UNICEF. Female genital mutilation/cutting: a statistical overview and exploration of the dynamics of change. 2013), nor are they sufficient to respond to health needs of millions of women and girls living with FGM. International efforts to address FGM have thus far focused primarily on preventing the practice, with less attention to treating associated health complications, caring for survivors, and engaging health care providers as key stakeholders. Recognizing this imperative, WHO developed guidelines on management of health complications of FGM. In this paper, based on foundational research for the development of WHO's guidelines, we situate the practice of FGM as a rights violation in the context of international and national policy and efforts, and explore the role of health providers in upholding health-related human rights of women at girls who are survivors, or who are at risk. Findings are based on a literature review of relevant international human rights treaties and UN Treaty Monitoring Bodies.

Effects of management strategies on glucocorticoids and behavior in Indian rhinoceros (Rhinoceros unicornis): translocation and operant conditioning.

PubMed

Capiro, Jonnie M; Stoops, Monica A; Freeman, Elizabeth W; Clawson, Dave; Schook, Mandi W

2014-01-01

The ex situ Indian rhino population experienced a decrease in genetic diversity indicating that the breeding program could possibly benefit from novel reproductive management strategies to ensure population sustainability. We sought to determine how management tools used for reproductive management, specifically translocation and operant conditioning, impact physiological and behavioral measures of welfare in Indian rhinos. First, an adrenocorticotropic hormone challenge performed in an adult male resulted in a 38-fold increase in urinary and a 3.5-fold increase in fecal glucocorticoid metabolites (FGM). Mean and peak FGM differed among three females, but all demonstrated elevated (P < 0.0001) concentrations for variable durations after translocation that lasted up to 9 weeks. Lastly, behavioral and adrenal responses of two females to operant conditioning to stand during transrectal ultrasound exams were monitored and rhinos differed in their mean and peak FGM concentrations. However, FGM were not different before versus during training or on pasture versus in the barn. One female exhibited more stereotypic behavior during training in the barn than on pasture (P < 0.05); although, stereotypies (1.73% of time) were relatively uncommon overall. In summary, individual variation exists in FGM both at baseline levels and in response to a stressor. In addition, while a transient rise in glucocorticoid activity post-translocation indicated that Indian rhinos have a physiological response to changes in their environment, minor alterations in daily routines using operant conditioning only resulted in minimal changes in behaviors and FGM. © 2014 Wiley Periodicals Inc.

Female Genital Cutting

MedlinePlus

... in which FGM/C is regularly practiced. Recent research shows that these efforts may be working. In some regions, education is changing attitudes and influencing a family's choice to have FGM/C performed. For example, in Egypt, 96% of women 45 to 49 ...

Knowledge, attitudes and practices of female genital mutilation/cutting among health care professionals in The Gambia: a multiethnic study

PubMed Central

2013-01-01

Background Female genital mutilation/cutting (FGM/C) is a harmful traditional practice with severe consequences for the health and well-being of girls and women. Health care professionals (HCPs) are therefore expected to be aware of how to identify and manage these consequences in order to ensure that those affected by the practice receive quality health care. Moreover, their integration and legitimacy within the communities allow them to play a key role in the prevention of the practice. Nevertheless, the perception of HCPs on FGM/C has been barely explored in African contexts. This study seeks to contribute to this field of knowledge by examining the knowledge, attitudes, and practices regarding FGM/C among HCPs working in rural settings in The Gambia. Methods A cross-sectional descriptive study was designed through a quantitative methodology, following a multiethnic approach. A pre-tested questionnaire with open and closed-ended questions was created. Forty medical students from the Community-based Medical Programme were trained to administer the questionnaire, face to face, at village health facilities in rural areas of The Gambia. A final sample of 468 HCPs included all nurse cadres and midwives. Results A significant proportion of Gambian HCPs working in rural areas embraced the continuation of FGM/C (42.5%), intended to subject their own daughters to it (47.2%), and reported having already performed it during their medical practice (7.6%). However, their knowledge, attitudes, and practices were shaped by sex and ethnic identity. Women showed less approval for continuation of FGM/C and higher endorsement of the proposed strategies to prevent it than men. However, it was among ethnic groups that differences were more substantial. HCPs belonging to traditionally practicing groups were more favourable to the perpetuation and medicalisation of FGM/C, suggesting that ethnicity prevails over professional identity. Conclusions These findings demonstrate an urgent need to build HCP’s capacities for FGM/C-related complications, through strategies adapted to their specific characteristics in terms of sex and ethnicity. A culturally and gender sensitive training programme might contribute to social change, promoting the abandonment of FGM/C, avoiding medicalisation, and ensuring accurate management of its health consequences. PMID:24040762

Symposium on Numerical and Physical Aspects of Aerodynamic Flows (2nd), 17-20 January 1983,

DTIC Science & Technology

1983-01-01

Speeds, S.S. Stahara ,,- Navier-Stokes Computational Study of the Influence of Shell Geometry on the Magnus Effect at Supersonic Speeds, W.B. Sturek...pressure over cylindrical forebody is also depicted here for distributions with data are presented. The pitot reference purposes. This particular cross... cylindrical fuselage. juncture (y/r>0, z/r=l) than the lower juncture The conclusion is consistent to the experimental (y/rrO, z/r-l). A rapid expansion

Long duration ash probe

DOEpatents

Hurley, J.P.; McCollor, D.P.; Selle, S.J.

1994-07-26

A long duration ash probe includes a pressure shell connected to a port in a combustor with a sample coupon mounted on a retractable carriage so as to retract the sample coupon within the pressure shell during soot blowing operation of the combustor. A valve mounted at the forward end of the pressure shell is selectively closeable to seal the sample coupon within the shell, and a heating element in the shell is operable to maintain the desired temperature of the sample coupon while retracted within the shell. The carriage is operably mounted on a pair of rails within the shell for longitudinal movement within the shell. A hollow carrier tube connects the hollow cylindrical sample coupon to the carriage, and extends through the carriage and out the rearward end thereof. Air lines are connected to the rearward end of the carrier tube and are operable to permit coolant to pass through the air lines and thence through the carrier tube to the sample coupon so as to cool the sample coupon. 8 figs.

Long duration ash probe

DOEpatents

Hurley, John P.; McCollor, Don P.; Selle, Stanley J.

1994-01-01

A long duration ash probe includes a pressure shell connected to a port in a combustor with a sample coupon mounted on a retractable carriage so as to retract the sample coupon within the pressure shell during sootblowing operation of the combustor. A valve mounted at the forward end of the pressure shell is selectively closeable to seal the sample coupon within the shell, and a heating element in the shell is operable to maintain the desired temperature of the sample coupon while retracted within the shell. The carriage is operably mounted on a pair of rails within the shell for longitudinal movement within the shell. A hollow carrier tube connects the hollow cylindrical sample coupon to the carriage, and extends through the carriage and out the rearward end thereof. Air lines are connected to the rearward end of the carrier tube and are operable to permit coolant to pass through the air lines and thence through the carrier tube to the sample coupon so as to cool the sample coupon.

A novel method for the photographic recovery of fingermark impressions from ammunition cases using digital imaging.

PubMed

Porter, Glenn; Ebeyan, Robert; Crumlish, Charles; Renshaw, Adrian

2015-03-01

The photographic preservation of fingermark impression evidence found on ammunition cases remains problematic due to the cylindrical shape of the deposition substrate preventing complete capture of the impression in a single image. A novel method was developed for the photographic recovery of fingermarks from curved surfaces using digital imaging. The process involves the digital construction of a complete impression image made from several different images captured from multiple camera perspectives. Fingermark impressions deposited onto 9-mm and 0.22-caliber brass cartridge cases and a plastic 12-gauge shotgun shell were tested using various image parameters, including digital stitching method, number of images per 360° rotation of shell, image cropping, and overlap. The results suggest that this method may be successfully used to recover fingermark impression evidence from the surfaces of ammunition cases or other similar cylindrical surfaces. © 2014 American Academy of Forensic Sciences.

A theoretical investigation of noise reduction through the cylindrical fuselage of a twin-engine, propeller-driven aircraft

NASA Technical Reports Server (NTRS)

Bhat, R. B.; Mixson, J. S.

1978-01-01

Interior noise in the fuselage of a twin-engine, propeller-driven aircraft with two propellers rotating in opposite directions is studied analytically. The fuselage was modeled as a stiffened cylindrical shell with simply supported ends, and the effects of stringers and frames were averaged over the shell surface. An approximate mathematical model of the propeller noise excitation was formulated which includes some of the propeller noise characteristics such as sweeping pressure waves around the sidewalls due to propeller rotation and the localized nature of the excitation with the highest levels near the propeller plane. Results are presented in the form of noise reduction, which is the difference between the levels of external and interior noise. The influence of propeller noise characteristics on the noise reduction was studied. The results indicate that the sweep velocity of the excitation around the fuselage sidewalls is critical to noise reduction.

Use of principle velocity patterns in the analysis of structural acoustic optimization.

PubMed

Johnson, Wayne M; Cunefare, Kenneth A

2007-02-01

This work presents an application of principle velocity patterns in the analysis of the structural acoustic design optimization of an eight ply composite cylindrical shell. The approach consists of performing structural acoustic optimizations of a composite cylindrical shell subject to external harmonic monopole excitation. The ply angles are used as the design variables in the optimization. The results of the ply angle design variable formulation are interpreted using the singular value decomposition of the interior acoustic potential energy. The decomposition of the acoustic potential energy provides surface velocity patterns associated with lower levels of interior noise. These surface velocity patterns are shown to correspond to those from the structural acoustic optimization results. Thus, it is demonstrated that the capacity to design multi-ply composite cylinders for quiet interiors is determined by how well the cylinder be can designed to exhibit particular surface velocity patterns associated with lower noise levels.

Formation of a quasi-hollow beam of high-energy heavy ions using a multicell resonance RF deflector

NASA Astrophysics Data System (ADS)

Minaev, S. A.; Sitnikov, A. L.; Golubev, A. A.; Kulevoy, T. V.

2012-09-01

The generation of matter in an extreme state with precisely measurable parameters is of great interest for contemporary physics. One way of obtaining such a state is to irradiate the end of a hollow cylindrical shell at the center of which a test material is kept at a temperature of several Kelvin by an annular beam of high-energy heavy ions. Under the action of the beam, the shell starts explosively expanding both outwards and inwards, compressing the material to an extremely high pressure without subjecting it to direct heating. A method of producing a hollow cylindrical beam of high-energy heavy ions using a resonance rf deflector is described. The deflection of the beam in two transverse directions by means of an rf electric field allows it to rotate about the longitudinal axis and irradiate an annular domain on the end face of the target.

Educating about female genital mutilation.

PubMed

Holmes, Victoria; Farrington, Rebecca; Mulongo, Peggy

2017-01-01

Female genital mutilation (FGM) is illegal in the UK but nevertheless practised in some immigrant communities. Effective educational approaches are required to inform policy and to direct resources, often in the voluntary sector. The opinions in this article arise from discussions with professionals and members of FGM-practising communities. We highlight the importance of sharing experiences and expertise across health and social care professionals as well as working in partnership with culturally sensitive Non-Governmental Organisations. Enlisting the support of men and religious leaders is crucial to breaking down barriers in male-dominated communities and dispelling myths about FGM being a 'requirement' of faith.

Fisher's geometric model predicts the effects of random mutations when tested in the wild.

PubMed

Stearns, Frank W; Fenster, Charles B

2016-02-01

Fisher's geometric model of adaptation (FGM) has been the conceptual foundation for studies investigating the genetic basis of adaptation since the onset of the neo Darwinian synthesis. FGM describes adaptation as the movement of a genotype toward a fitness optimum due to beneficial mutations. To date, one prediction of FGM, the probability of improvement is related to the distance from the optimum, has only been tested in microorganisms under laboratory conditions. There is reason to believe that results might differ under natural conditions where more mutations likely affect fitness, and where environmental variance may obscure the expected pattern. We chemically induced mutations into a set of 19 Arabidopsis thaliana accessions from across the native range of A. thaliana and planted them alongside the premutated founder lines in two habitats in the mid-Atlantic region of the United States under field conditions. We show that FGM is able to predict the outcome of a set of random induced mutations on fitness in a set of A. thaliana accessions grown in the wild: mutations are more likely to be beneficial in relatively less fit genotypes. This finding suggests that FGM is an accurate approximation of the process of adaptation under more realistic ecological conditions. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

[Male perceptions of sequelae associated with female genital mutilation].

PubMed

Jiménez-Ruiz, Ismael; Almansa Martínez, Pilar; Pastor Bravo, María Del Mar

2016-01-01

To explore men's knowledge of the negative consequences of female genital mutilation (FGM) to women's health in countries where this practice is performed. A qualitative methodology was used with an ethnomethodological approach. Both individual and group semi-structured interviews concerning FGM were conducted with 25 men, selected by triple sampling. A study presentation letter was provided to participants, together with an informed consent declaration. Permission was also procured to record the interviews in audio format. Data analysis was performed using the Atlas Ti7 software. Those participants against FGM are aware of the range of complications this practice can cause, being able to identify physical, obstetric, psychological, sexuality and social consequences in women subjected to FGM. However, those men who are in favour display a general ignorance of the problems resulting from this practice. Participants from countries where FGM is performed who are against this practice are more aware of the negative consequences than those who claim to be in favour. The design of awareness-raising programmes and other tools to combat female genital mutilation must highlight the implications for women's and girls' health, and include family-targeted campaigns which involve men in the process of eradicating this practice. Copyright © 2016 SESPAS. Published by Elsevier Espana. All rights reserved.

Crossing borders: Discussing the evidence relating to the mental health needs of women exposed to female genital mutilation

PubMed Central

Mulongo, Peggy; McAndrew, Sue; Hollins Martin, Caroline

2014-01-01

The terms ‘Female Circumcision’ (FC), ‘FG Cutting’ (FGC) and ‘FG Mutilation’ (FGM) refer to procedures involving the partial or total removal of the external female genitalia for non-medical reasons. In practicing countries, FGC/FC is more widely used, as it is believed to be inoffensive, providing more impartial ways of discussing the practice. Positive beliefs about FC/FGC include virginity, marriage prospects, family reputation, or passage to adulthood. Regardless of terminology, the practice exists in at least 28 African counties, and a few Asian and Middle Eastern countries. In Western society, FGM is considered a breach of human rights, being outlawed in a number of countries. With immigration trends, FGC is now prominent in Western society among practicing communities. While the past decade has seen an increase in studies and recommendations for health-care support related to the physical health consequences of FGM, little is known about the psychological impact and its management. For many girls and women, FGC is a traumatic practice, transforming it to FGM and affecting their mental health. This discussion paper focuses on evidence relating to the mental health consequences of FGM, therapeutic interventions, and the mental health nurse's role in addressing the needs of this group of women. PMID:24548699

The ongoing violence against women: Female Genital Mutilation/Cutting.

PubMed

Muteshi, Jacinta K; Miller, Suellen; Belizán, José M

2016-04-18

Female Genital Mutilation/Cutting (FGM/C) comprises different practices involving cutting, pricking, removing and sometimes sewing up external female genitalia for non-medical reasons. The practice of FGM/C is highly concentrated in a band of African countries from the Atlantic coast to the Horn of Africa, in areas of the Middle East such as Iraq and Yemen, and in some countries in Asia like Indonesia. Girls exposed to FGM/C are at risk of immediate physical consequences such as severe pain, bleeding, and shock, difficulty in passing urine and faeces, and sepsis. Long-term consequences can include chronic pain and infections. FGM/C is a deeply entrenched social norm, perpetrated by families for a variety of reasons, but the results are harmful. FGM/C is a human rights issue that affects girls and women worldwide. The practice is decreasing, due to intensive advocacy activities of international, national, and grassroots agencies. An adolescent girl today is about a third less likely to be cut than 30 years ago. However, the rates of abandonment are not high enough, and change is not happening as rapidly as necessary. Multiple interventions have been implemented, but the evidence base on what works is lacking. We in reproductive health must work harder to find strategies to help communities and families abandon these harmful practices.

Between Moral Relativism and Moral Hypocrisy: Reframing the Debate on "FGM".

PubMed

Earp, Brian D

2016-06-01

The spectrum of practices termed "Female Genital Mutilation" (or FGM) by the World Health Organization is sometimes held up as a counterexample to moral relativism. Those who advance this line of thought suggest the practices are so harmful in terms of their physical and emotional consequences, as well as so problematic in terms of their sexist or oppressive implications, that they provide sufficient, rational grounds for the assertion of a universal moral claim--namely, that all forms of FGM are wrong, regardless of the cultural context. However, others point to cultural bias and moral double standards on the part of those who espouse this argument, and have begun to question the received interpretation of the relevant empirical data on FGM as well. In this article I assess the merits of these competing perspectives. I argue that each of them involves valid moral concerns that should be taken seriously in order to move the discussion forward. In doing so, I draw on the biomedical "enhancement" literature in order to develop a novel ethical framework for evaluating FGM (and related interventions--such as female genital "cosmetic" surgery and nontherapeutic male circumcision) that takes into account the genuine harms that are at stake in these procedures, but which does not suffer from being based on cultural or moral double standards.

Reasons for and Experiences With Surgical Interventions for Female Genital Mutilation/Cutting (FGM/C): A Systematic Review.

PubMed

Berg, Rigmor C; Taraldsen, Sølvi; Said, Maryan A; Sørbye, Ingvil Krarup; Vangen, Siri

2017-08-01

Because female genital mutilation/cutting (FGM/C) leads to changes in normal genital anatomy and functionality, women are increasingly seeking surgical interventions for their FGM/C-related concerns. To conduct a systematic review of empirical quantitative and qualitative research on interventions for women with FGM/C-related complications. We conducted systematic searches up to May 2016 in 16 databases to obtain references from different disciplines. We accepted all study designs consisting of girls and women who had been subjected to FGM/C and that examined a reparative intervention for a FGM/C-related concern. We screened the titles, abstracts, and full texts of retrieved records for relevance. Then, we assessed the methodologic quality of the included studies and extracted and synthesized the study data. All outcomes were included. Of 3,726 retrieved references, 71 studies including 7,291 women were eligible for inclusion. We identified three different types of surgical intervention: defibulation or surgical separation of fused labia, excision of a cyst with or without some form of reconstruction, and clitoral or clitoral-labial reconstruction. Reasons for seeking surgical interventions consisted of functional complaints, sexual aspirations, esthetic aspirations, and identity recovery. The most common reasons for defibulation were a desire for improved sexual pleasure, vaginal appearance, and functioning. For cyst excision, cystic swelling was the main reason for seeking excision; for reconstruction, the main reason was to recover identity. Data on women's experiences with a surgical intervention are sparse, but we found that women reported easier births after defibulation. Our findings also suggested that most women were satisfied with defibulation (overall satisfaction = 50-100%), typically because of improvements in their sexual lives. Conversely, the results suggested that defibulation had low social acceptance and that the procedure created distress in some women who disliked the new appearance of their genitalia. Most women were satisfied with clitoral reconstruction, but approximately one third were dissatisfied with or perceived a worsening in the esthetic look. The information health care professionals give to women who seek surgical interventions for FGM/C should detail the intervention options available and what women can realistically expect from such interventions. The systematic review was conducted in accordance with guidelines, but there is a slight possibility that studies were missed. There are some data on women's motivations for surgery for FGM/C-related concerns, but little is known about whether women are satisfied with the surgery, and experiences appear mixed. Berg RC, Taraldsen S, Said MA, et al. Reasons for and Experiences With Surgical Interventions for Female Genital Mutilation/Cutting (FGM/C): A Systematic Review. J Sex Med 2017;14:977-990. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Load transfer in the stiffener-to-skin joints of a pressurized fuselage

NASA Technical Reports Server (NTRS)

Johnson, Eric R.; Rastogi, Naveen

1995-01-01

Structural analyses are developed to determine the linear elastic and the geometrically nonlinear elastic response of an internally pressurized, orthogonally stiffened, composite material cylindrical shell. The configuration is a long circular cylindrical shell stiffened on the inside by a regular arrangement of identical stringers and identical rings. Periodicity permits the analysis of a unit cell model consisting of a portion of the shell wall centered over one stringer-ring joint. The stringer-ring-shell joint is modeled in an idealized manner; the stiffeners are mathematically permitted to pass through one another without contact, but do interact indirectly through their mutual contact with the shell at the joint. Discrete beams models of the stiffeners include a stringer with a symmetrical cross section and a ring with either a symmetrical or an asymmetrical open section. Mathematical formulations presented for the linear response include the effect of transverse shear deformations and the effect of warping of the ring's cross section due to torsion. These effects are important when the ring has an asymmetrical cross section because the loss of symmetry in the problem results in torsion and out-of-plane bending of the ring, and a concomitant rotation of the joint at the stiffener intersection about the circumferential axis. Data from a composite material crown panel typical of a large transport fuselage structure are used for two numerical examples. Although the inclusion of geometric nonlinearity reduces the 'pillowing' of the shell, it is found that bending is localized to a narrow region near the stiffener. Including warping deformation of the ring into the analysis changes the sense of the joint rotation. Transverse shear deformation models result in increased joint flexibility.

Redirection and Splitting of Sound Waves by a Periodic Chain of Thin Perforated Cylindrical Shells

NASA Astrophysics Data System (ADS)

Bozhko, Andrey; Sánchez-Dehesa, José; Cervera, Francisco; Krokhin, Arkadii

2017-06-01

The scattering of sound by finite and infinite chains of equally spaced perforated metallic cylindrical shells in an ideal (inviscid) and viscous fluid is theoretically studied using rigorous analytical and numerical approaches. Because of perforations, a chain of thin shells is practically transparent for sound within a wide range of frequencies. It is shown that strong scattering and redirection of sound by 90° may occur only for a discrete set of frequencies (Wood's anomalies) where the leaky eigenmodes are excited. The spectrum of eigenmodes consists of antisymmetric and symmetric branches with normal and anomalous dispersion, respectively. The antisymmetric eigenmode turns out to be a deaf mode, since it cannot be excited at normal incidence. However, at slightly oblique incidence, both modes can be resonantly excited at different but close frequencies. The symmetric mode, due to its anomalous dispersion, scatters sound in the "wrong" direction. This property may find an application for the splitting of the two resonant harmonics of the incoming signal into two beams propagating along the chain in the opposite directions. A chain of perforated cylinders may also be used as a passive antenna that detects the direction to the incoming signal by measuring the frequencies of the waves excited in the chain. Calculations are presented for aluminum shells in viscous air where the effects of anomalous scattering, redirection, and signal splitting are well manifested.

Effectiveness of health education as an intervention designed to prevent female genital mutilation/cutting (FGM/C): a systematic review.

PubMed

Waigwa, Susan; Doos, Lucy; Bradbury-Jones, Caroline; Taylor, Julie

2018-04-12

Female Genital Mutilation/Cutting (FGM/C) is a harmful practice that violates the human rights of women and girls. Despite global efforts to restrict the practice, there have been few reports on major positive changes to the problem. Health education interventions have been successful in preventing various health conditions and promoting service use. They have also been regarded as promising interventions for preventing FGM/C. The objective of this systematic review is to synthesise findings of studies about effectiveness of health education as an intervention to prevent FGM/C. The electronic databases searched were MEDLINE, EMBASE, Cochrane library, Web of Science, Psych INFO, CINAHL and ASSIA. Our search included papers published in the English language without date limits. Study quality was assessed using the Mixed Methods Appraisal Tool (MMAT). A predesigned data recording form was used to extract data from the included studies which were summarised by comparing similar themes. Twelve out of 359 individual studies met our inclusion criteria. Seven studies were quantitative, three were qualitative and two used mixed methods. Six studies tested before and after the interventions, four studies assessed the effectiveness of previous interventions used by different research teams and two studies endorsed the intervention. Four main factors emerged and were associated with facilitating or hindering the effectiveness of health education interventions: sociodemographic factors; socioeconomic factors; traditions and beliefs; and intervention strategy, structure and delivery. It is vital to target factors associated with facilitating or hindering the effectiveness of health education for FGM/C. This increases the possibility of effective, collective change in behaviour and attitude which leads to the sustainable prevention of FGM/C and ultimately the improved reproductive health and well-being of individuals and communities.

Thirty-year trends in the prevalence and severity of female genital mutilation: a comparison of 22 countries

PubMed Central

Heymann, Jody

2017-01-01

Introduction Female genital mutilation (FGM) harms women’s health and well-being and is widely considered a violation of human rights. The United Nations has called for elimination of the practice by 2030. Methods We used household survey data to measure trends in the prevalence of FGM in 22 countries. We also examined trends in the severity of the practice by measuring changes in the prevalence of flesh removal, infibulation and symbolic ‘nicking’ of the genitals. We evaluated the extent to which measurement error may have influenced our estimates by observing the consistency of reports for the same birth cohorts over successive survey waves. Results The prevalence of all types of FGM fell in 17 of 22 countries we examined. The vast majority of women who undergo FGM have flesh removed from their genitals, likely corresponding to the partial or total removal of the clitoris and labia. Infibulation is still practised throughout much of sub-Saharan Africa. Its prevalence has declined in most countries, but in Chad, Mali and Sierra Leone the prevalence has increased by 2–8 percentage points over 30 years. Symbolic nicking of the genitals is relatively rare but becoming more common in Burkina Faso, Chad, Guinea and Mali. Conclusion FGM is becoming less common over time, but it remains a pervasive practice in some countries: more than half of women in 7 of the 22 countries we examined still experience FGM. The severity of the procedures has not changed substantially over time. Rigorous evaluation of interventions aimed at eliminating or reducing the harms associated with the practice is needed. PMID:29225952

Multicanister overpack topical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lorenz, B.D., Fluor Daniel Hanford

1997-03-25

The Spent Nuclear Fuel MCO is a single-use container that consists of a cylindrical shell, five to six fuel baskets, a shield plug, and features necessary for maintaining the structural integrity of the MCO while providing criticality control and fuel processing capability.

Investigation of mechanical properties and deformation behavior of single-crystal Al-Cu core-shell nanowire generated using non-equilibrium molecular dynamics simulation

NASA Astrophysics Data System (ADS)

Sarkar, Jit

2018-06-01

Molecular dynamics (MD) simulation studies were carried out to generate a cylindrical single-crystal Al-Cu core-shell nanowire and its mechanical properties like yield strength and Young's modulus were evaluated in comparison to a solid aluminum nanowire and hollow copper nanowire which combines to constitute the core-shell structure respectively. The deformation behavior due to changes in the number of Wigner-Seitz defects and dislocations during the entire tensile deformation process was thoroughly studied for the Al-Cu core-shell nanowire. The single-crystal Al-Cu core-shell nanowire shows much higher yield strength and Young's modulus in comparison to the solid aluminum core and hollow copper shell nanowire due to tangling of dislocations caused by lattice mismatch between aluminum and copper. Thus, the Al-Cu core-shell nanowire can be reinforced in different bulk matrix to develop new type of light-weight nanocomposite materials with greatly enhanced material properties.

Controversial issues: female genital mutilation.

PubMed

Richards, D

2000-01-01

As immigrant women from African countries enter the U.S., Canada, Australia, and Western Europe, western health care providers are beginning to see patients affected by the cultural practice of Female Genital Mutilation (FGM). Unfamiliar with the practice, either medically or culturally, these providers are turning to medical librarians for information. Complicating the issue are the strong negative feelings most western health care workers have about FGM, which appears to them to be both barbaric and cruel. These feelings may conflict strongly with those of their immigrant patients, who regard the practice as normal and desirable. Both medical and cultural information are needed for the professional to provide treatment of medical conditions, while also establishing a good relationship with the FGM affected patient. This article identifies and describes the most important refereed journal article databases, available now over the Internet, providing both medical and cultural information on FGM, and the most useful Web sites for health professionals, librarians, and interested laypersons who need information about this difficult multicultural issue.

Optimum gradient material for a functionally graded dental implant using metaheuristic algorithms.

PubMed

Sadollah, Ali; Bahreininejad, Ardeshir

2011-10-01

Despite dental implantation being a great success, one of the key issues facing it is a mismatch of mechanical properties between engineered and native biomaterials, which makes osseointegration and bone remodeling problematical. Functionally graded material (FGM) has been proposed as a potential upgrade to some conventional implant materials such as titanium for selection in prosthetic dentistry. The idea of an FGM dental implant is that the property would vary in a certain pattern to match the biomechanical characteristics required at different regions in the hosting bone. However, matching the properties does not necessarily guarantee the best osseointegration and bone remodeling. Little existing research has been reported on developing an optimal design of an FGM dental implant for promoting long-term success. Based upon remodeling results, metaheuristic algorithms such as the genetic algorithms (GAs) and simulated annealing (SA) have been adopted to develop a multi-objective optimal design for FGM implantation design. The results are compared with those in literature. Copyright © 2011 Elsevier Ltd. All rights reserved.

Dismantling the man-made myths upholding female genital mutilation.

PubMed

Jiménez Ruiz, Ismael; Almansa Martínez, Pilar; Alcón Belchí, Carolina

2017-05-01

Female genital mutilation (FGM) is internationally considered an affront to human rights and an act of violence against women and young girls. Furthermore, it hierarchizes and perpetuates inequality and denies women and girls the right to physical and psychosexual integrity. The aim of this study is to detect the weak points and false premises underlying male justification of FGM and to present demythologization as a health education tool. We used a qualitative methodology with an ethonursing focus via semistructured individual and group interviews in 25 men associated with FGM. Our results found that nine myths and their mythologization are presented through the masculine voices of those associated with this tradition. These myths are used as justification by men and women in order to uphold the practice of FGM. Demythologization as a nursing intervention based on reorienting or restructuring models of cultural care allows us to work against the false premises making up the myths which act to protect this tradition.

Compression strength of composite primary structural components

NASA Technical Reports Server (NTRS)

Johnson, Eric R.

1994-01-01

The linear elastic response is determined for an internally pressurized, long circular cylindrical shell stiffened on the inside by a regular arrangement of identical stringers and identical rings. Periodicity of this configuration permits the analysis of a portion of the shell wall centered over a generic stringer-ring joint; i.e., a unit cell model. The stiffeners are modeled as discrete beams, and the stringer is assumed to have a symmetrical cross section and the ring an asymmetrical section. Asymmetery causes out-of-plane bending and torsion of the ring. Displacements are assumed as truncated double Fourier series plus simple terms in the axial coordinate to account for the closed and pressure vessel effect (a non-periodic effect). The interacting line loads between the stiffeners and the inside shell wall are Lagrange multipliers in the formulation, and they are also assumed as truncated Fourier series. Displacement continuity constraints between the stiffeners and shell along the contact lines are satisfied point-wise. Equilibrium is imposed by the principle of virtual work. A composite material crown panel from the fuselage of a large transport aircraft is the numerical example. The distributions of the interacting line loads, and the out-of-plane bending moment and torque in the ring, are strongly dependent on modeling the deformations due to transverse shear and cross-sectional warping of the ring in torsion. This paper contains the results from the semiannual report on research on 'Pressure Pillowing of an Orthogonally Stiffened Cylindrical Shell'. The results of the new work are illustrated in the included appendix.

The effect of consignment to broodmare sales on physiological stress measured by faecal glucocorticoid metabolites in pregnant Thoroughbred mares.

PubMed

Schulman, Martin; Becker, Annet; Ganswindt, Stefanie; Guthrie, Alan; Stout, Tom; Ganswindt, Andre

2014-01-17

Validation of a method for the minimally-invasive measurement of physiological stress will help understanding of risk factors that may contribute to stress-associated events including recrudescence of Equid herpesvirus (EHV), which is anecdotally associated with sales consignment of pregnant Thoroughbred mares. In this study we compared two similar groups of late-gestation Thoroughbred broodmares on the same farm: a consigned Sales group (N = 8) and a non-consigned Control group (N = 6). The Sales mares were separated from their paddock companions and grouped prior to their preparation for, transport to, and return from the sales venue. Both groups were monitored by sampling at regular intervals from 5 days prior to until 14 days after the sales date (D0) to measure physiological stress in terms of changes in faecal glucocorticoid metabolite (FGM) concentrations, and for event-related viral recrudescence via daily body temperature measurements and periodic nasal swabs for PCR analysis for EHV-1 and -4 DNA. In both groups, FGM levels increased post-sales before returning to pre-sales levels. Specifically, FGM concentrations in the Sales mares were significantly higher on D + 3 and D + 10 than on D-4 and D-3 (F = 12.03, P < 0.0001, Post hoc: P = 0.0003-0.0008) and in the Control group FGM concentrations were higher on D + 10 than D-4 (F = 5.52, P = 0.004, Post hoc: P = 0.005). Interestingly, mean FGM levels in Control mares were significantly higher at 4 of the 5 sampling points (t = 5.64-2.25, p = 0.0001-0.044). Only one (Sales) mare showed PCR evidence of EHV-1 shedding. Using FGM to measure physiological stress was supported by the increases observed in all mares after Sales consignment, including those not consigned to the sale. Monitoring FGM levels therefore represents an appropriate, minimally-invasive method for future studies to assess the contribution of physiological stress to EHV recrudescence in horses transported to sales or equestrian events.

Prevalence of female genital mutilation and its effect on women's health in Bale zone, Ethiopia: a cross-sectional study.

PubMed

Bogale, Daniel; Markos, Desalegn; Kaso, Muhammedawel

2014-10-16

Females' genital mutilation (FGM) is one of the harmful traditional practices affecting the health of women and children. It has a long-term physiological, sexual and psychological effect on women. It remains still a serious problem for large proportion of women in most sub-Saharan Africa countries including Ethiopia. A community based cross sectional study design which is supplemented by qualitative method was conducted in 2014. A total of 634 reproductive age women were involved in the quantitative part of the study. The respondents were drawn from five randomly selected districts of Bale zone. The total sample was allocated proportionally to each district based on the number of reproductive age women it has. Purposive sampling method was used for qualitative study. Then, data were collected using pre-tested and structured questionnaire. The collected data were analyzed by SPSS for windows version 16.0. Multiple logistic regressions were carried out to examine the existence of relationship between FGM and selected determinant factors. Variables significant in the bivariate analysis were then entered into a multiple logistic regression analysis. In this study, 486 (78.5%) of women had undergone some form of FGM with 75% lower and 82% upper confidence interval. To get married, to get social acceptance, to safeguard virginity, to suppress sexual desire and religious recommendations were the main reasons of FGM. The reported immediate complications were excessive bleeding at the time of the procedure, infection, urine retention and swelling of genital organ. Muslim women and women from rural areas were significantly more likely to have undergone the procedure. In addition to these, compared to women 15-20 years old older women were more likely to report themselves having undergone FGM. Although younger women, those from urban residence and some religions are less likely to have had FGM it is still extremely common in this zone. Deep cultural issues and strongly personally held beliefs which are not simple to predict or quantify are likely to be involved in the perpetuation of FGM. Efforts to eradicate the practice should incorporate a human rights approach rather than rely solely on the damaging health consequences.

Non-invasive monitoring of adrenocortical activity in captive African Penguin (Spheniscus demersus) by measuring faecal glucocorticoid metabolites.

PubMed

Ozella, L; Anfossi, L; Di Nardo, F; Pessani, D

2015-12-01

Measurement of faecal glucocorticoid metabolites (FGMs) has become a useful and widely-accepted method for the non-invasive evaluation of stress in vertebrates. In this study we assessed the adrenocortical activity of five captive African Penguins (Spheniscus demersus) by means of FGM evaluation following a biological stressor, i.e. capture and immobilization. In addition, we detected individual differences in secretion of FGMs during a stage of the normal biological cycle of penguins, namely the breeding period, without any external or induced causes of stress. Our results showed that FGM concentrations peaked 5.5-8h after the induced stress in all birds, and significantly decreased within 30 h. As predictable, the highest peak of FGMs (6591 ng/g) was reached by the youngest penguin, which was at its first experience with the stressor. This peak was 1.8-2.7-fold higher compared to those of the other animals habituated to the stimulus. For the breeding period, our results revealed that the increase in FGMs compared to ordinary levels, and the peaks of FGMs, varied widely depending on the age and mainly on the reproductive state of the animal. The bird which showed the lowest peak (2518 ng/g) was an old male that was not in a reproductive state at the time of the study. Higher FGM increases and peaks were reached by the two birds which were brooding (male: 5552%, 96,631 ng/g; female: 1438%, 22,846 ng/g) and by the youngest bird (1582%, 39,700 ng/g). The impact of the reproductive state on FGM levels was unexpected compared to that produced by the induced stress. The EIA used in this study to measure FGM levels proved to be a reliable tool for assessing individual and biologically-relevant changes in FGM concentrations in African Penguin. Moreover, this method allowed detection of physiological stress during the breeding period, and identification of individual differences in relation to the reproductive status. The increase in FGM levels as a response to capture and immobilization suggests that the measured metabolites are appropriate indicators of adrenal activity in these birds. Copyright © 2015 Elsevier Inc. All rights reserved.

The effect of consignment to broodmare Sales on physiological stress measured by faecal glucocorticoid metabolites in pregnant Thoroughbred mares

PubMed Central

2014-01-01

Background Validation of a method for the minimally-invasive measurement of physiological stress will help understanding of risk factors that may contribute to stress-associated events including recrudescence of Equid herpesvirus (EHV), which is anecdotally associated with sales consignment of pregnant Thoroughbred mares. In this study we compared two similar groups of late-gestation Thoroughbred broodmares on the same farm: a consigned Sales group (N = 8) and a non-consigned Control group (N = 6). The Sales mares were separated from their paddock companions and grouped prior to their preparation for, transport to, and return from the sales venue. Both groups were monitored by sampling at regular intervals from 5 days prior to until 14 days after the sales date (D0) to measure physiological stress in terms of changes in faecal glucocorticoid metabolite (FGM) concentrations, and for event-related viral recrudescence via daily body temperature measurements and periodic nasal swabs for PCR analysis for EHV-1 and -4 DNA. Results In both groups, FGM levels increased post-sales before returning to pre-sales levels. Specifically, FGM concentrations in the Sales mares were significantly higher on D + 3 and D + 10 than on D-4 and D-3 (F = 12.03, P < 0.0001, Post hoc: P = 0.0003 – 0.0008) and in the Control group FGM concentrations were higher on D + 10 than D-4 (F = 5.52, P = 0.004, Post hoc: P = 0.005). Interestingly, mean FGM levels in Control mares were significantly higher at 4 of the 5 sampling points (t = 5.64 – 2.25, p = 0.0001 – 0.044). Only one (Sales) mare showed PCR evidence of EHV-1 shedding. Conclusions Using FGM to measure physiological stress was supported by the increases observed in all mares after Sales consignment, including those not consigned to the sale. Monitoring FGM levels therefore represents an appropriate, minimally-invasive method for future studies to assess the contribution of physiological stress to EHV recrudescence in horses transported to sales or equestrian events. PMID:24433380

Analytical Investigation of Elastic Thin-Walled Cylinder and Truncated Cone Shell Intersection Under Internal Pressure.

PubMed

Zamani, J; Soltani, B; Aghaei, M

2014-10-01

An elastic solution of cylinder-truncated cone shell intersection under internal pressure is presented. The edge solution theory that has been used in this study takes bending moments and shearing forces into account in the thin-walled shell of revolution element. The general solution of the cone equations is based on power series method. The effect of cone apex angle on the stress distribution in conical and cylindrical parts of structure is investigated. In addition, the effect of the intersection and boundary locations on the circumferential and longitudinal stresses is evaluated and it is shown that how quantitatively they are essential.

Line spring model and its applications to part-through crack problems in plates and shells

NASA Technical Reports Server (NTRS)

Erdogan, Fazil; Aksel, Bulent

1988-01-01

The line spring model is described and extended to cover the problem of interaction of multiple internal and surface cracks in plates and shells. The shape functions for various related crack geometries obtained from the plane strain solution and the results of some multiple crack problems are presented. The problems considered include coplanar surface cracks on the same or opposite sides of a plate, nonsymmetrically located coplanar internal elliptic cracks, and in a very limited way the surface and corner cracks in a plate of finite width and a surface crack in a cylindrical shell with fixed end.

Line Spring Model and Its Applications to Part-Through Crack Problems in Plates and Shells

NASA Technical Reports Server (NTRS)

Erdogan, F.; Aksel, B.

1986-01-01

The line spring model is described and extended to cover the problem of interaction of multiple internal and surface cracks in plates and shells. The shape functions for various related crack geometries obtained from the plane strain solution and the results of some multiple crack problems are presented. The problems considered include coplanar surface cracks on the same or opposite sides of a plate, nonsymmetrically located coplanar internal elliptic cracks, and in a very limited way the surface and corner cracks in a plate of finite width and a surface crack in a cylindrical shell with fixed end.

Dynamical Analysis of a Cylindrical Piezoelectric Transducer

NASA Astrophysics Data System (ADS)

LU, P.; LEE, K. H.; LIM, S. P.

2003-01-01

In the present paper, the vibration of a cylindrical piezoelectric transducer induced by applied voltage, which can be used as the stator transducer of a cylindrical micromotor, is studied based on shell theory. The transducer is modelled as a thin elastic cylinder. The properties of the vibration modes of the transducer, such as mode frequencies and amplitude ratios of the mode shapes, are determined following Galerkin method. The response of the transducer under the four electric sources with 90° phase difference is then obtained by the modal summation method. With the results, the performance of the transducer under the electric sources can be estimated. The present work provides a general and precise theoretical modelling on the dynamical movement of the transducer.

A study of methods of prediction and measurement of the transmission of sound through the walls of light aircraft

NASA Technical Reports Server (NTRS)

Forssen, B.; Wang, Y. S.; Raju, P. K.; Crocker, M. J.

1981-01-01

The acoustic intensity technique was applied to the sound transmission loss of panel structures (single, composite, and stiffened). A theoretical model of sound transmission through a cylindrical shell is presented.

A study of methods of prediction and measurement of the transmission of sound through the walls of light aircraft

NASA Astrophysics Data System (ADS)

Forssen, B.; Wang, Y. S.; Raju, P. K.; Crocker, M. J.

1981-08-01

The acoustic intensity technique was applied to the sound transmission loss of panel structures (single, composite, and stiffened). A theoretical model of sound transmission through a cylindrical shell is presented.

Evidence to inform education, training and supportive work environments for midwives involved in the care of women with female genital mutilation: a review of global experience.

PubMed

Dawson, Angela; Turkmani, Sabera; Fray, Shairon; Nanayakkara, Susie; Varol, Nesrin; Homer, Caroline

2015-01-01

to identify how midwives in low and middle income countries (LMIC) and high income countries (HIC) care for women with female genital mutilation (FGM), their perceived challenges and what professional development and workplace strategies might better support midwives to provide appropriate quality care. an integrative review involving a narrative synthesis of the literature was undertaken to include peer reviewed research literature published between 2004 and 2014. 10 papers were included in the review, two from LMIC and eight from HIC. A lack of technical knowledge and limited cultural competency was identified, as well as socio-cultural challenges in the abandonment process of the practice, particularly in LMIC settings. Training in the area of FGM was limited. One study reported the outcomes of an education initiative that was found to be beneficial. professional education and training, a working environment supported by guidelines and responsive policy and community education, are necessary to enable midwives to improve the care of women with FGM and advocate against the practice. improved opportunities for midwives to learn about FGM and receive advice and support, alongside opportunities for collaborative practice in contexts that enable the effective reporting of FGM to authorities, may be beneficial and require further investigation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Surgical and nonsurgical interventions for vulvar and clitoral pain in girls and women living with female genital mutilation: A systematic review.

PubMed

Ezebialu, Ifeanyichukwu; Okafo, Obiamaka; Oringanje, Chukwudi; Ogbonna, Udoezuo; Udoh, Ekong; Odey, Friday; Meremikwu, Martin M

2017-02-01

Vulvar and clitoral pain are known complications of female genital mutilation (FGM). Several interventions have been used to treat these conditions. This review focuses on surgical and nonsurgical interventions to improve vulvar and clitoral pain in women living with FGM. To evaluate the impact of nonsurgical and surgical interventions for alleviating vulvar and clitoral pain in women living with any type of FGM and to assess the associated adverse events. The search included the following major databases: Cochrane Central Register for Controlled Trials (CENTRAL), MEDLINE, Scopus, Web of Science, and ClinicalTrials.gov. These were searched from inception until August 10, 2015 without any language restrictions. Study designs included randomized controlled trials, cluster randomized trials, nonrandomized trials, cohort studies, case-control studies, controlled before-and-after studies, historical control studies, and interrupted time series with reported data comparing outcomes among women with FGM who were treated for clitoral or vulvar pain with either surgical or nonsurgical interventions. Two team members independently screened studies for eligibility. No studies were included. Limited information exists on management of vulvar and clitoral pain in women living with FGM. This constitutes an important area for further research. CRD42015024521. © 2017 International Federation of Gynecology and Obstetrics.The World Health Organization retains copyright and all other rights in the manuscript of this article as submitted for publication.

Female sexual dysfunction in female genital mutilation.

PubMed

Elneil, Sohier

2016-01-01

Female genital mutilation (FGM), otherwise known as female genital cutting (FGC), is currently very topical and has become a significant global political issue. The impact of FGM on the lives of women and girls is enormous, as it often affects both their psychology and physical being. Among the complications that are often under-reported and not always acknowledged is female sexual dysfunction (FSD). FSD presents with a complex of symptoms including lack of libido, arousability and orgasm. This often occurs in tandem with chronic urogenital pain and anatomical disruption due to perineal scarring.To treat FSD in FGM each woman needs specifically directed holistic care, geared to her individual case. This may include psychological support, physiotherapy and, on occasion, reconstructive surgery. In many cases the situation is complicated by symptoms of chronic pelvic pain, which can make treatment increasingly difficult as this issue needs a defined multidisciplinary approach for its effective management in its own right. The problems suffered by women with FGM are wholly preventable, as the practice need not happen. The current global momentum to address the social, cultural, economic and medical issues of FGM is being supported by communities, governments, non-governmental agencies (NGOs) and healthcare providers. It is only by working together that the practice can be abolished and women and girls may be free from this practice and its associated consequences. © The Author(s) 2016.

Microsatellite Digital Magnetometer SMILE - Present State and Future Trends

NASA Astrophysics Data System (ADS)

Belyayev, Serhiy; Ivchenko, Nickolay

2010-05-01

The fluxgate magnetometers (FGM) are probably the most widespread instruments used onboard spacecrafts for both scientific and service purposes. The recent trend to decrease the weight and size of the spacecrafts requires creating as small as possible but enough sensitive FGM. A joint Swedish-Ukrainian team made the development of such a magnetometer and as the result the Small Magnetometer In Low mass Experiment (SMILE) - a digital fluxgate microsatellite magnetometer - was created [1]. Majority of electronic units of this FGM were combined in a digital integrated circuit - a Field Programmable Gate Array (FPGA). The FPGA provides full processing (determined by a digital correlation algorithm) of amplified and digitized fluxgate sensor output signals and provides both FGM output data and feedback signals. Such digital design makes the instrument very flexible, reduces power consumption and opens possibilities for customization of the operation modes. It allows miniaturizing the electronic unit and, together with the smallest in the world low noise three-component fluxgate sensor with the side dimension of 20 mm and weight about 20 grams only, the small but enough sensitive space qualified FGM is created. SMILE magnetometer was successfully flown onboard the NASA Cascades-2 sounding rocket, and is to fly in the LAPLander package onboard the ESA REXUS-8 student sounding rocket [2]. Unfortunately, such a design of electronic circuit does not allow us to realize all possibilities of the miniature sensor. The separate tests of the sensor with highest-class analog electronics showed that its noise level may be reduced to as low value as 10…15 picoTesla at 1 Hz. Also the use of volume compensation in the sensor provides high geometrical stability of the axes and improved performance compared to component compensated sensors. The measured parameters appear to be comparable or even better than these of best stationary FGM and, if realized in small enough volume and weight, such a sensitive but small FGM could be a good candidate for planned Lunar missions where the weight is the major restriction factor. This stimulated further research in the direction of the analysis and elimination of noise sources of digital design, as well as of the optimization of FGM electronic circuit structure. The description of the obtained results of the electronic unit upgrade and recent FGM model tests are given and future improvement directions are discussed. These works are partially supported by NSAU contract No. 1499. References: 1. Åke Forslund, Serhiy Belyayev, Nickolay Ivchenko, Göran Olsson, Terry Edberg and Andriy Marusenkov, Miniaturized digital fluxgate magnetometer for small spacecraft applications 2008 Meas. Sci. Technol. 19 2. T. Sundberg, N. Ivchenko, D. Borglund, P. Ahlen, M. Gustavsson, C. Jonsson, J. Juhlen, O. Neunet, J. Sandstrom, E. Sund, M. Wartelski, C. Westlund, L. Xin, Small Recoverable Payload for Deployable Sounding Rocket Experiments. ESA Special Publication SP671

Lossless acoustic half-bipolar cylindrical cloak with negative-index metamaterial

NASA Astrophysics Data System (ADS)

Lee, Yong Y.; Ahn, Doyeol

2018-05-01

A lossless acoustic half-bipolar cylindrical cloak that has an exposed bottom is considered. Here, we show that a cloak that includes a complementary region including a negative-index medium inside of the cloaking shell works in the illumination direction independently even in the presence of the exposed bottom of the structure. This is due to the fact that the phase velocity of the wave in the normal direction can be cancelled in the presence of a boundary containing a negative-index medium that reduces scattering significantly.

Mothers' Perceptions of Female Genital Mutilation

ERIC Educational Resources Information Center

Ahanonu, E. L.; Victor, O.

2014-01-01

The practice of female genital mutilation (FGM) is widespread in Nigeria. This study was conducted to assess the perceptions of FGM among mothers at a primary healthcare centre in Lagos, Nigeria. A convenience sample of 95 mothers completed the pre-tested, semi-structured questionnaires. Data analysis was carried out using descriptive statistics…

PREFACE: 12th International Symposium on Multiscale, Multifunctional and Functionally Graded Materials (FGM 2012)

NASA Astrophysics Data System (ADS)

Zhou, Zhangjian; Li, Jingfeng; Zhang, Lianmeng; Ge, Changchun

2013-03-01

The 12th International Symposium on Multiscale, Multifunctional and Functionally Graded Materials (FGM-2012) was held in Beijing, China, from 22-36 October 2012. This was part of a series of conferences organized every two years endorsed by International Advisory Committee for FGM's, which serves as a forum for scientists, educators, engineers and young students interested in the development of functionally graded materials (FGM). The series continues from the previous international symposium on FGM held in Sendai, Japan (1990), San Francisco, USA (1992), Lausanne, Switzerland (1994), Tsukuba, Japan (1996), Dresden, Germany (1998), Estes Park, USA (2000), Beijing, China (2002), Leuven, Belgium (2004), Hawaii, USA (2006), Sendai, Japan (2008) and Guimaraes, Portugal (2010). Functionally graded materials are non-uniform materials which are designed with embodied continuous spatial variations in composition and microstructure for the specific purpose of adjusting their thermal, structural, mechanical, biological or functional response to specific application conditions. Such multi-phase materials cover a range of space and time scales, and are best understood by means of a comprehensive multiscale, multiphysics approach. These kinds of materials are presently in the forefront of materials research, receiving worldwide attention. They have a broad range of applications including for example, biomedical, biomechanical, automotive, aerospace, mechanical, civil, nuclear, and naval engineering. New applications are continuously being discovered and developed. The objective of the FGM-2012 intends to provide opportunities for exchanging ideas and discussing state-of-the-art theories, techniques and applications in the fields of multiscale, multifunctional and FGM, through invited lectures, oral and poster presentations. FGM-2012 was organized and hosted by University of Science and Technology Beijing, China, together with Tsing-hua University and Wuhan University of Technology, and was supported by National Natural Science Foundation of China. On behalf of the organizing committee of FGM-2012, I express my great appreciation to their support of the symposium. Nearly 100 scholars and students from Japan, Brazil, Germany, Russia, United States of America, Portugal, France, Switzerland, Turkey, Singapore, China, and so on, attended FGM-2012, and 57 of the presented papers were collected and selected for publication. The subjects of these papers cover simulation and characterization, advanced fabrication technology, novel application of FGM and layer materials. I cordially thank all of the authors and attendees for their support, and my appreciation is also given to the advisory committee, organizing committee, and the conference volunteers for their hard work. Professor Zhangjian Zhou Proceedings Editor Beijing, December 2012 Committees International Advisory Committee Professor Glaucio H Paulino, USA Professor Marek-Jerzy Pindera, USA Professor Jeong-Ho Kim, USA Professor Emer Fazil Erdogan, USA Professor Dr Monika Willert-Porada, Germany Professor Emer Wolfgang G J Bunk, Germany Professor Omer Van Der Biest, Belgium Professor Michael M Gasik, Finland Professor Evgeny Levashov, Russia Professor Lianmeng Zhang, China Professor Qingjie Zhang, China Professor Wei Pan, China Professor Chang-Chun Ge, China Professor Jing-Feng Li, China Professor Zhangjian Zhou, China Associate Professor Serkan Dag, Turkey Professor Fernando A Rochinha, Brazil Professor Emilio C N Silva, Brazil Professor Luis August Rocha, Portugal Dr Sasa Novak, Slovenia Dr Masayuki Niino, Japan Professor Akira Kawasaki, Japan Professor Ichiro Shiota, Japan Dr Akinaga Kumakawa, Japan Dr Yoshikazu Shinohara, Japan Professor Kiyotaka Matsuura, Japan Professor Yoshinari Miyamoto, Japan Professor Takashi Goto, Japan Professor Yoshimi Watanabe, Japan Professor Kazuhiro Hasezaki, Japan Professor Soshu Kirihara, Japan Professor Emer Toshio Hirai, Japan Mr Choji Endou, Japan Dr Seiichi Uemura, Japan Local Organizing Committee Professor Changchun Ge (Chairman) Professor Xuanhui Qu Professor Jingfeng Li Professor Wei Pan Professor Lianmeng Zhang; Professor Qingjie Zhang Professor Qiang Shen Professor Jianghong Gong Dr Xianhui Li Dr Min Xia

Three-Dimensional Solution of the Free Vibration Problem for Metal-Ceramic Shells Using the Method of Sampling Surfaces

NASA Astrophysics Data System (ADS)

Kulikov, G. M.; Plotnikova, S. V.

2017-03-01

The possibility of using the method of sampling surfaces (SaS) for solving the free vibration problem of threedimensional elasticity for metal-ceramic shells is studied. According to this method, in the shell body, an arbitrary number of SaS parallel to its middle surface are selected in order to take displacements of these surfaces as unknowns. The SaS pass through the nodes of a Chebyshev polynomial, which improves the convergence of the SaS method significantly. As a result, the SaS method can be used to obtain analytical solutions of the vibration problem for metal-ceramic plates and cylindrical shells that asymptotically approach the exact solutions of elasticity as the number of SaS tends to infinity.

Pre-Test Analysis Predictions for the Shell Buckling Knockdown Factor Checkout Tests - TA01 and TA02

NASA Technical Reports Server (NTRS)

Thornburgh, Robert P.; Hilburger, Mark W.

2011-01-01

This report summarizes the pre-test analysis predictions for the SBKF-P2-CYL-TA01 and SBKF-P2-CYL-TA02 shell buckling tests conducted at the Marshall Space Flight Center (MSFC) in support of the Shell Buckling Knockdown Factor (SBKF) Project, NASA Engineering and Safety Center (NESC) Assessment. The test article (TA) is an 8-foot-diameter aluminum-lithium (Al-Li) orthogrid cylindrical shell with similar design features as that of the proposed Ares-I and Ares-V barrel structures. In support of the testing effort, detailed structural analyses were conducted and the results were used to monitor the behavior of the TA during the testing. A summary of predicted results for each of the five load sequences is presented herein.

Implosion of Cylindrical Cavities via Short Duration Impulsive Loading

NASA Astrophysics Data System (ADS)

Huneault, Justin; Higgins, Andrew

2014-11-01

An apparatus has been developed to study the collapse of a cylindrical cavity in gelatin subjected to a symmetric impact-driven impulsive loading. A gas-driven annular projectile is accelerated to approximately 50 m/s, at which point it impacts a gelatin casting confined by curved steel surfaces that allow a transition from an annular geometry to a cylindrically imploding motion. The implosion is visualized by a high-speed camera through a window which forms the top confining wall of the implosion cavity. The initial size of the cavity is such that the gelatin wall is two to five times thicker than the impacting projectile. Thus, during impact the compression wave which travels towards the cavity is closely followed by a rarefaction resulting from the free surface reflection of the compression wave in the projectile. As the compression wave in the gelatin reaches the inner surface, it will also reflect as a rarefaction wave. The interaction between the rarefaction waves from the gelatin and projectile free surfaces leads to large tensile stresses resulting in the spallation of a relatively thin shell. The study focuses on the effect of impact parameters on the thickness and uniformity of the imploding shell formed by the cavitation in the imploding gelatin cylinder.

The use of COD and plastic instability in crack propagation and arrest in shells

NASA Technical Reports Server (NTRS)

Erdogan, F.; Ratwani, M.

1974-01-01

The initiation, growth, and possible arrest of fracture in cylindrical shells containing initial defects are dealt with. For those defects which may be approximated by a part-through semi-elliptic surface crack which is sufficiently shallow so that part of the net ligament in the plane of the crack is still elastic, the existing flat plate solution is modified to take into account the shell curvature effect as well as the effect of the thickness and the small scale plastic deformations. The problem of large defects is then considered under the assumptions that the defect may be approximated by a relatively deep meridional part-through surface crack and the net ligament through the shell wall is fully yielded. The results given are based on an 8th order bending theory of shallow shells using a conventional plastic strip model to account for the plastic deformations around the crack border.

Testing and recommended practices to improve nurse tank safety, phase I : [research brief].

DOT National Transportation Integrated Search

2013-10-01

This study focuses on determining causes and possible inspection remediation strategies to reduce the occurrence of anhydrous ammonia (NH3) nurse tank failures. Nurse tanks are cylindrical steel tank shells with hemispherical or elliptical end caps r...

Deployment of Large-Size Shell Constructions by Internal Pressure

NASA Astrophysics Data System (ADS)

Pestrenin, V. M.; Pestrenina, I. V.; Rusakov, S. V.; Kondyurin, A. V.

2015-11-01

A numerical study on the deployment pressure (the minimum internal pressure bringing a construction from the packed state to the operational one) of large laminated CFRP shell structures is performed using the ANSYS engineering package. The shell resists both membrane and bending deformations. Structures composed of shell elements whose median surface has an involute are considered. In the packed (natural) states of constituent elements, the median surfaces coincide with their involutes. Criteria for the termination of stepwise solution of the geometrically nonlinear problem on determination of the deployment pressure are formulated, and the deployment of cylindrical, conical (full and truncated cones), and large-size composite shells is studied. The results obtained are shown by graphs illustrating the deployment pressure in relation to the geometric and material parameters of the structure. These studies show that large pneumatic composite shells can be used as space and building structures, because the deployment pressure in them only slightly differs from the excess pressure in pneumatic articles made from films and soft materials.

A Mixed Multi-Field Finite Element Formulation for Thermopiezoelectric Composite Shells

NASA Technical Reports Server (NTRS)

Lee, Ho-Jun; Saravanos, Dimitris A.

1999-01-01

Analytical formulations are presented which account for the coupled mechanical, electrical, and thermal response of piezoelectric composite shell structures. A new mixed multi-field laminate theory is developed which combines "single layer" assumptions for the displacements along with layerwise fields for the electric potential and temperature. This laminate theory is formulated using curvilinear coordinates and is based on the principles of linear thermopiezoelectricity. The mechanics have the inherent capability to explicitly model both the active and sensory responses of piezoelectric composite shells in thermal environment. Finite element equations are derived and implemented for an eight-noded shell element. Numerical studies are conducted to investigate both the sensory and active responses of piezoelectric composite shell structures subjected to thermal loads. Results for a cantilevered plate with an attached piezoelectric layer are com- pared with corresponding results from a commercial finite element code and a previously developed program. Additional studies are conducted on a cylindrical shell with an attached piezoelectric layer to demonstrate capabilities to achieve thermal shape control on curved piezoelectric structures.

Computer-Controlled Cylindrical Polishing Process for Large X-Ray Mirror Mandrels

NASA Technical Reports Server (NTRS)

Khan, Gufran S.; Gubarev, Mikhail; Speegle, Chet; Ramsey, Brian

2010-01-01

We are developing high-energy grazing incidence shell optics for hard-x-ray telescopes. The resolution of a mirror shells depends on the quality of cylindrical mandrel from which they are being replicated. Mid-spatial-frequency axial figure error is a dominant contributor in the error budget of the mandrel. This paper presents our efforts to develop a deterministic cylindrical polishing process in order to keep the mid-spatial-frequency axial figure errors to a minimum. Simulation software is developed to model the residual surface figure errors of a mandrel due to the polishing process parameters and the tools used, as well as to compute the optical performance of the optics. The study carried out using the developed software was focused on establishing a relationship between the polishing process parameters and the mid-spatial-frequency error generation. The process parameters modeled are the speeds of the lap and the mandrel, the tool s influence function, the contour path (dwell) of the tools, their shape and the distribution of the tools on the polishing lap. Using the inputs from the mathematical model, a mandrel having conical approximated Wolter-1 geometry, has been polished on a newly developed computer-controlled cylindrical polishing machine. The preliminary results of a series of polishing experiments demonstrate a qualitative agreement with the developed model. We report our first experimental results and discuss plans for further improvements in the polishing process. The ability to simulate the polishing process is critical to optimize the polishing process, improve the mandrel quality and significantly reduce the cost of mandrel production

An initial investigation of the long-term trends in the fluxgate magnetometer (FGM) calibration parameters on the four Cluster spacecraft

NASA Astrophysics Data System (ADS)

Alconcel, L. N. S.; Fox, P.; Brown, P.; Oddy, T. M.; Lucek, E. L.; Carr, C. M.

2014-07-01

Over the course of more than 10 years in operation, the calibration parameters of the outboard fluxgate magnetometer (FGM) sensors on the four Cluster spacecraft are shown to be remarkably stable. The parameters are refined on the ground during the rigorous FGM calibration process performed for the Cluster Active Archive (CAA). Fluctuations in some parameters show some correlation with trends in the sensor temperature (orbit position). The parameters, particularly the offsets, of the spacecraft 1 (C1) sensor have undergone more long-term drift than those of the other spacecraft (C2, C3 and C4) sensors. Some potentially anomalous calibration parameters have been identified and will require further investigation in future. However, the observed long-term stability demonstrated in this initial study gives confidence in the accuracy of the Cluster magnetic field data. For the most sensitive ranges of the FGM instrument, the offset drift is typically 0.2 nT per year in each sensor on C1 and negligible on C2, C3 and C4.

An initial investigation of the long-term trends in the fluxgate magnetometer (FGM) calibration parameters on the four Cluster spacecraft

NASA Astrophysics Data System (ADS)

Alconcel, L. N. S.; Fox, P.; Brown, P.; Oddy, T. M.; Lucek, E. L.; Carr, C. M.

2014-01-01

Over the course of more than ten years in operation, the calibration parameters of the outboard fluxgate magnetometer (FGM) sensors on the four Cluster spacecraft are shown to be remarkably stable. The parameters are refined on the ground during the rigorous FGM calibration process performed for the Cluster Active Archive (CAA). Fluctuations in some parameters show some correlation with trends in the sensor temperature (orbit position). The parameters, particularly the offsets, of the Spacecraft1 (C1) sensor have undergone more long-term drift than those of the other spacecraft (C2, C3 and C4) sensors. Some potentially anomalous calibration parameters have been identified and will require further investigation in future. However, the observed long-term stability demonstrated in this initial study gives confidence in the relative accuracy of the Cluster magnetic field data. For the most sensitive ranges of the FGM instrument, the offset drift is typically 0.2 nT yr-1 in each sensor on C1 and negligible on C2, C3 and C4.

Recyclable fluorescent gold nanocluster membrane for visual sensing of copper(II) ion in aqueous solution.

PubMed

Lin, Zhijin; Luo, Fenqiang; Dong, Tongqing; Zheng, Liyan; Wang, Yaxian; Chi, Yuwu; Chen, Guonan

2012-05-21

Recently, metal-selective fluorescent chemosensors have attracted intense attention for their simple and real-time tracking of metal ions in environmental samples. However, most of the existing fluorescent sensors are one-off sensors and thus suffer from large amount of reagent consumption, significant experimental cost and raising the risk of environmental pollution. In this paper, we developed a green (low reagent consumption, low-toxicity reagent use), recyclable, and visual sensor for Cu(2+) in aqueous solution by using a fluorescent gold nanoclusters membrane (FGM) as the sensing unit, basing on our findings on gold nanoclusters (Au NCs) that the bovine serum albumin (BSA)-coated Au NCs exhibit excellent membrane-forming ability under the isoelectric point of BSA, and thus enable us to obtain a new type of sensing membrane (i.e. FGM) by denaturing Au NCs; the fluorescence of FGM can be significantly quenched by Cu(2+) ion, and the quenched fluorescence can be totally recovered by histidine; the as-prepared FGM is very stable and recyclable, which makes it an ideal sensing material.

Improved porous silicon (P-Si) microarray based PSA (prostate specific antigen) immunoassay by optimized surface density of the capture antibody

PubMed Central

Lee, SangWook; Kim, Soyoun; Malm, Johan; Jeong, Ok Chan; Lilja, Hans; Laurell, Thomas

2014-01-01

Enriching the surface density of immobilized capture antibodies enhances the detection signal of antibody sandwich microarrays. In this study, we improved the detection sensitivity of our previously developed P-Si (porous silicon) antibody microarray by optimizing concentrations of the capturing antibody. We investigated immunoassays using a P-Si microarray at three different capture antibody (PSA - prostate specific antigen) concentrations, analyzing the influence of the antibody density on the assay detection sensitivity. The LOD (limit of detection) for PSA was 2.5ngmL−1, 80pgmL−1, and 800fgmL−1 when arraying the PSA antibody, H117 at the concentration 15µgmL−1, 35µgmL−1 and 154µgmL−1, respectively. We further investigated PSA spiked into human female serum in the range of 800fgmL−1 to 500ngmL−1. The microarray showed a LOD of 800fgmL−1 and a dynamic range of 800 fgmL−1 to 80ngmL−1 in serum spiked samples. PMID:24016590

Reconstructive surgery for female genital mutilation starts sexual functioning in Sudanese woman: a case report.

PubMed

Fazari, Atif B E; Berg, Rigmor C; Mohammed, Wafaa A; Gailii, Enas B; Elmusharaf, Khalifa

2013-11-01

Female genital mutilation (FGM) involves the partial or complete removal of the external female genitalia and/or other injury to the female genital organs whether for cultural or other nontherapeutic reasons. The study aims to describe the method of and findings from reconstructive surgery for FGM victims. We present a case of a 24-year-old Sudanese female, who had undergone ritual FGM type III as a young girl. She had suffered from a large, vulval mass for the last 6 years and came to the clinic because of apareunia. We performed mass excision and reconstructive surgery of the mutilated genital tissue. The giant mass was successfully removed. Remaining genital tissues were approximated and sutured, with hemostasis assured for the reconstructed organs on each side. Reconstructive surgery for women who suffer sexual consequences from FGM is feasible, with a high degree of client acceptance and satisfaction. It restores some of women's natural genital anatomy, and offers the potential for improved female sexuality. © 2013 International Society for Sexual Medicine.

LQR Control of Thin Shell Dynamics: Formulation and Numerical Implementation

NASA Technical Reports Server (NTRS)

delRosario, R. C. H.; Smith, R. C.

1997-01-01

A PDE-based feedback control method for thin cylindrical shells with surface-mounted piezoceramic actuators is presented. Donnell-Mushtari equations modified to incorporate both passive and active piezoceramic patch contributions are used to model the system dynamics. The well-posedness of this model and the associated LQR problem with an unbounded input operator are established through analytic semigroup theory. The model is discretized using a Galerkin expansion with basis functions constructed from Fourier polynomials tensored with cubic splines, and convergence criteria for the associated approximate LQR problem are established. The effectiveness of the method for attenuating the coupled longitudinal, circumferential and transverse shell displacements is illustrated through a set of numerical examples.

Determination of Flux-Gate Magnetometer Spin Axis Offsets with the Electron Drift Instrument

NASA Astrophysics Data System (ADS)

Plaschke, Ferdinand; Nakamura, Rumi; Giner, Lukas; Teubenbacher, Robert; Chutter, Mark; Leinweber, Hannes K.; Magnes, Werner

2014-05-01

Spin-stabilization of spacecraft enormously supports the in-flight calibration of onboard flux-gate magnetometers (FGMs): eight out of twelve calibration parameters can be determined by minimization of spin tone and harmonics in the calibrated magnetic field measurements. From the remaining four parameters, the spin axis offset is usually obtained by analyzing observations of Alfvénic fluctuations in the solar wind. If solar wind measurements are unavailable, other methods for spin axis offset determination need to be used. We present two alternative methods that are based on the comparison of FGM and electron drift instrument (EDI) data: (1) EDI measures the gyration periods of instrument-emitted electrons in the ambient magnetic field. They are inversely proportional to the magnetic field strength. Differences between FGM and EDI measured field strengths can be attributed to inaccuracies in spin axis offset, if the other calibration parameters are accurately known. (2) For EDI electrons to return to the spacecraft, they have to be sent out in perpendicular direction to the ambient magnetic field. Minimization of the variance of electron beam directions with respect to the FGM-determined magnetic field direction also yields an estimate of the spin axis offset. Prior to spin axis offset determination, systematic inaccuracies in EDI gyration period measurements and in the transformation of EDI beam directions into the FGM spin-aligned reference coordinate system have to be corrected. We show how this can be done by FGM/EDI data comparison, as well.

Inter-instrument calibration using magnetic field data from Flux Gate Magnetometer (FGM) and Electron Drift Instrument (EDI) onboard Cluster

NASA Astrophysics Data System (ADS)

Nakamura, R.; Plaschke, F.; Teubenbacher, R.; Giner, L.; Baumjohann, W.; Magnes, W.; Steller, M.; Torbert, R. B.; Vaith, H.; Chutter, M.; Fornaçon, K.-H.; Glassmeier, K.-H.; Carr, C.

2013-07-01

We compare the magnetic field data obtained from the Flux-Gate Magnetometer (FGM) and the magnetic field data deduced from the gyration time of electrons measured by the Electron Drift Instrument (EDI) onboard Cluster to determine the spin axis offset of the FGM measurements. Data are used from orbits with their apogees in the magnetotail, when the magnetic field magnitude was between about 20 nT and 500 nT. Offset determination with the EDI-FGM comparison method is of particular interest for these orbits, because no data from solar wind are available in such orbits to apply the usual calibration methods using the Alfvén waves. In this paper, we examine the effects of the different measurement conditions, such as direction of the magnetic field relative to the spin plane and field magnitude in determining the FGM spin-axis offset, and also take into account the time-of-flight offset of the EDI measurements. It is shown that the method works best when the magnetic field magnitude is less than about 128 nT and when the magnetic field is aligned near the spin-axis direction. A remaining spin-axis offset of about 0.4 ~ 0.6 nT was observed between July and October 2003. Using multi-point multi-instrument measurements by Cluster we further demonstrate the importance of the accurate determination of the spin-axis offset when estimating the magnetic field gradient.

Interinstrument calibration using magnetic field data from the flux-gate magnetometer (FGM) and electron drift instrument (EDI) onboard Cluster

NASA Astrophysics Data System (ADS)

Nakamura, R.; Plaschke, F.; Teubenbacher, R.; Giner, L.; Baumjohann, W.; Magnes, W.; Steller, M.; Torbert, R. B.; Vaith, H.; Chutter, M.; Fornaçon, K.-H.; Glassmeier, K.-H.; Carr, C.

2014-01-01

We compare the magnetic field data obtained from the flux-gate magnetometer (FGM) and the magnetic field data deduced from the gyration time of electrons measured by the electron drift instrument (EDI) onboard Cluster to determine the spin-axis offset of the FGM measurements. Data are used from orbits with their apogees in the magnetotail, when the magnetic field magnitude was between about 20 and 500 nT. Offset determination with the EDI-FGM comparison method is of particular interest for these orbits, because no data from solar wind are available in such orbits to apply the usual calibration methods using the Alfvén waves. In this paper, we examine the effects of the different measurement conditions, such as direction of the magnetic field relative to the spin plane and field magnitude in determining the FGM spin-axis offset, and also take into account the time-of-flight offset of the EDI measurements. It is shown that the method works best when the magnetic field magnitude is less than about 128 nT and when the magnetic field is aligned near the spin-axis direction. A remaining spin-axis offset of about 0.4 ∼ 0.6 nT was observed for Cluster 1 between July and October 2003. Using multipoint multi-instrument measurements by Cluster we further demonstrate the importance of the accurate determination of the spin-axis offset when estimating the magnetic field gradient.

An analytical method for free vibration analysis of functionally graded beams with edge cracks

NASA Astrophysics Data System (ADS)

Wei, Dong; Liu, Yinghua; Xiang, Zhihai

2012-03-01

In this paper, an analytical method is proposed for solving the free vibration of cracked functionally graded material (FGM) beams with axial loading, rotary inertia and shear deformation. The governing differential equations of motion for an FGM beam are established and the corresponding solutions are found first. The discontinuity of rotation caused by the cracks is simulated by means of the rotational spring model. Based on the transfer matrix method, then the recurrence formula is developed to get the eigenvalue equations of free vibration of FGM beams. The main advantage of the proposed method is that the eigenvalue equation for vibrating beams with an arbitrary number of cracks can be conveniently determined from a third-order determinant. Due to the decrease in the determinant order as compared with previous methods, the developed method is simpler and more convenient to analytically solve the free vibration problem of cracked FGM beams. Moreover, free vibration analyses of the Euler-Bernoulli and Timoshenko beams with any number of cracks can be conducted using the unified procedure based on the developed method. These advantages of the proposed procedure would be more remarkable as the increase of the number of cracks. A comprehensive analysis is conducted to investigate the influences of the location and total number of cracks, material properties, axial load, inertia and end supports on the natural frequencies and vibration mode shapes of FGM beams. The present work may be useful for the design and control of damaged structures.

FEMALE GENITAL MUTILATION: ARE WE WINNING?

PubMed

Makinde, O N; Elusiyan, J B E; Adeyemi, A B; Taiwo, O T

2012-06-01

For more than 25 years, efforts have been geared towards curtailing the practice of female genital mutilation (FGM) in countries like Nigeria. This study was designed to see if all these efforts have made any impact in reducing the prevalence of FGM appreciably in the south-West of Nigeria. To determine the prevalence of female genital mutilation and profiling the trends of FGM affected patients. A prospective study based on direct observation of the external genitalia by health-care workers . Five hundred and sixty five females less than 15 years of age. The children emergency and gynaecological wards of the Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria from 1st of January to December 31s 2007. Forty one point nine percent of the patients examined had female genital mutilation, 93.2% of these had the procedure before attaining the age of one year. Type 2 FGM predominated (58.22%). The procedure was performed predominantly (64.6%) by traditional birth attendants. The decision to have the procedure done was influenced in 78% of cases by mothers and grandmothers. In 35.4% of cases, there were immediate and short term complications. Demands of tradition predominated (59.1%) as the most important reason for the practice of female genital mutilation. The practice of FGM appears to be still highly prevalent and resistant to change probably due to deep rooted socio-cultural factors. Strategies such as public education campaigns highlighting its negative impact on health and disregard for human rights should be evolved.

GOJJAM ZONE, WESTERN AMHARA, ETHIOPIA.

PubMed

Andualem, Mulusew

2016-07-01

Female genital mutilation is one of the harmful traditional practices among women and girls. More than 130 million girls and women live today who have undergone female genital mutilation. In Ethiopia, a high prevalence (74.3% national and 68.5% in Amhara region) has been reported. This study was aimed to identify determinant factors of female genital mutilation practices in East Gojjam Zone, Western Amhara, Ethiopia community based cross sectional study was conducted among 730 women aged 15-49 years and having children < 5 years old in September, 2014. Data were collected using a pretested interviewer administered questionnaire. Descriptive statistics were used to describe study objectives, and bivariate and multivariate analysis to identify determinant factors to female genital mutilation. 718 women and 805 daughters participated in the study. FGM prevalence was 689 (96%) and 403 (49%) among women and daughters< 5 years of age, respectively. Type1 and type 2 FGMs were common and daughters <1 years of age exhibited 91% female genital mutilation. Daughters' age, parent education level, residence, women circumcision history, culture, health education, frequent health extension workers follow up and participation in anti FGM interventions were risk factors to female genital mutilation practice. Female genital mutilation practices continues to be a major problem to women and daughter <5 years of age in the study area. A number of factors were associated with FGM practices including daughters’ age, parent education level, residence, health education, culture, mothers circumcision history, frequent health extensions workers follow up and participation in anti FGM interventions were determinants to higher FGM practices.

Crossing borders: discussing the evidence relating to the mental health needs of women exposed to female genital mutilation.

PubMed

Mulongo, Peggy; McAndrew, Sue; Hollins Martin, Caroline

2014-08-01

The terms 'Female Circumcision' (FC), 'FG Cutting' (FGC) and 'FG Mutilation' (FGM) refer to procedures involving the partial or total removal of the external female genitalia for non-medical reasons. In practicing countries, FGC/FC is more widely used, as it is believed to be inoffensive, providing more impartial ways of discussing the practice. Positive beliefs about FC/FGC include virginity, marriage prospects, family reputation, or passage to adulthood. Regardless of terminology, the practice exists in at least 28 African counties, and a few Asian and Middle Eastern countries. In Western society, FGM is considered a breach of human rights, being outlawed in a number of countries. With immigration trends, FGC is now prominent in Western society among practicing communities. While the past decade has seen an increase in studies and recommendations for health-care support related to the physical health consequences of FGM, little is known about the psychological impact and its management. For many girls and women, FGC is a traumatic practice, transforming it to FGM and affecting their mental health. This discussion paper focuses on evidence relating to the mental health consequences of FGM, therapeutic interventions, and the mental health nurse's role in addressing the needs of this group of women. © 2014 The Authors. International Journal of Mental Health Nursing published by Wiley Publishing Asia Pty Ltd on behalf of Australian College of Mental Health Nurses Inc.

Fluid-structure interaction for nonlinear response of shells conveying pulsatile flow

NASA Astrophysics Data System (ADS)

Tubaldi, Eleonora; Amabili, Marco; Païdoussis, Michael P.

2016-06-01

Circular cylindrical shells with flexible boundary conditions conveying pulsatile flow and subjected to pulsatile pressure are investigated. The equations of motion are obtained based on the nonlinear Novozhilov shell theory via Lagrangian approach. The flow is set in motion by a pulsatile pressure gradient. The fluid is modeled as a Newtonian pulsatile flow and it is formulated using a hybrid model that contains the unsteady effects obtained from the linear potential flow theory and the pulsatile viscous effects obtained from the unsteady time-averaged Navier-Stokes equations. A numerical bifurcation analysis employs a refined reduced order model to investigate the dynamic behavior. The case of shells containing quiescent fluid subjected to the action of a pulsatile transmural pressure is also addressed. Geometrically nonlinear vibration response to pulsatile flow and transmural pressure are here presented via frequency-response curves and time histories. The vibrations involving both a driven mode and a companion mode, which appear due to the axial symmetry, are also investigated. This theoretical framework represents a pioneering study that could be of great interest for biomedical applications. In particular, in the future, a more refined model of the one here presented will possibly be applied to reproduce the dynamic behavior of vascular prostheses used for repairing and replacing damaged and diseased thoracic aorta in cases of aneurysm, dissection or coarctation. For this purpose, a pulsatile time-dependent blood flow model is here considered by applying physiological waveforms of velocity and pressure during the heart beating period. This study provides, for the first time in literature, a fully coupled fluid-structure interaction model with deep insights in the nonlinear vibrations of circular cylindrical shells subjected to pulsatile pressure and pulsatile flow.

Buckligami: Actuation of soft structures through mechanical instabilities

NASA Astrophysics Data System (ADS)

Lazarus, Arnaud; Reis, Pedro

2013-03-01

We present a novel mechanism for actuating soft structures, that is triggered through buckling. Our elastomeric samples are rapid-prototyped using digital fabrication and comprise of a cylindrical shell patterned with an array of voids, each of which is covered by a thin membrane. Decreasing the internal pressure of the structure induces local buckling of the ligaments of the pattern, resulting in controllable folding of the global structure. Using rigid inclusions to plug the voids in specific geometric arrangements allows us to excite a variety of different fundamental motions of the cylindrical shell, including flexure and twist. We refer to this new mechanism of buckling-induced folding as ``buckligami.'' Given that geometry, elasticity and buckling are the underlying ingredients of this local folding mechanism, the global actuation is scalable, reversible and repeatable. Characterization and rationalization of our experiments provide crucial fundamental understanding to aid the design of new scale-independent actuators, with potential implications in the field of soft robotics.

Awareness and predictors of female genital mutilation/cutting among young health advocates

PubMed Central

Abolfotouh, Sherif M; Ebrahim, Ahmed Z; Abolfotouh, Mostafa A

2015-01-01

The act of female genital mutilation/cutting (FGM/C) is considered internationally as a violent act against girls and women and a violation of their human rights. This study sought to assess the awareness and predictors of FGM/C in young Egyptian health advocates. A cross-sectional study of 600 medical students from a total of 2,500 members of the International Federation of Medical Students’ Associations (IFMSA)-Egypt, across all Egyptian medical schools, was conducted using a previously validated online Google survey. The overall prevalence of circumcision was 14.7/100 female students, with a significantly higher prevalence in students from rural areas (25%) than in non-rural areas (10.8%, P=0.001), and in those residing in Upper (southern) Egypt (20.6%) than in Lower (northern) Egypt (8.7%, P=0.003). The students’ mean percentage score for knowledge about the negative health consequences of FGM/C was 53.50±29.07, reflecting a modest level of knowledge; only 30.5% had a good level of knowledge. The mean percentage score for the overall attitude toward discontinuation of the practice of FGM/C was 76.29±17.93, reflecting a neutral attitude; 58.7% had a favorable attitude/norms toward discontinuation of the practice. Of circumcised students, approximately one-half (46.8%) were unwilling to have their daughters circumcised, and 60% reported no harm from being circumcised. After controlling for confounders, a negative attitude toward FGM/C was significantly (P<0.001 in all cases) associated with male sex, residency in Upper Egypt, rural origin, previous circumcision, and the preclinical medical phase of education. The low level of knowledge among even future health professions in our study suggests that communication, rather than passive learning, is needed to convey the potentially negative consequences of FGM/C and to drive a change in attitude toward discontinuation of this harmful practice. PMID:25759602

Advanced Vacuum Plasma Spray (VPS) for a Robust, Longlife and Safe Space Shuttle Main Engine (SSME)

NASA Technical Reports Server (NTRS)

Holmes, Richard R.; Elam, Sandra K.; McKechnie, Timothy N.; Power, Christopher A.

2010-01-01

In 1984, the Vacuum Plasma Spray Lab was built at NASA/Marshall Space Flight Center for applying durable, protective coatings to turbine blades for the space shuttle main engine (SSME) high pressure fuel turbopump. Existing turbine blades were cracking and breaking off after five hot fire tests while VPS coated turbine blades showed no wear or cracking after 40 hot fire tests. Following that, a major manufacturing problem of copper coatings peeling off the SSME Titanium Main Fuel Valve Housing was corrected with a tenacious VPS copper coating. A patented VPS process utilizing Functional Gradient Material (FGM) application was developed to build ceramic lined metallic cartridges for space furnace experiments, safely containing gallium arsenide at 1260 degrees centigrade. The VPS/FGM process was then translated to build robust, long life, liquid rocket combustion chambers for the space shuttle main engine. A 5K (5,000 Lb. thrust) thruster with the VPS/FGM protective coating experienced 220 hot firing tests in pristine condition with no wear compared to the SSME which showed blanching (surface pulverization) and cooling channel cracks in less than 30 of the same hot firing tests. After 35 of the hot firing tests, the injector face plates disintegrated. The VPS/FGM process was then applied to spraying protective thermal barrier coatings on the face plates which showed 50% cooler operating temperature, with no wear after 50 hot fire tests. Cooling channels were closed out in two weeks, compared to one year for the SSME. Working up the TRL (Technology Readiness Level) to establish the VPS/FGM process as viable technology, a 40K thruster was built and is currently being tested. Proposed is to build a J-2X size liquid rocket engine as the final step in establishing the VPS/FGM process TRL for space flight.

Chemical, Physiochemical, and Microstructural Properties, and Probiotic Survivability of Fermented Goat Milk Using Polymerized Whey Protein and Starter Culture Kefir Mild 01.

PubMed

Wang, Hao; Wang, Cuina; Wang, Mu; Guo, Mingruo

2017-11-01

A set-type fermented goat milk (FGM) using polymerized whey protein (PWP) as main thickening agent and Kefir Mild 01 as starter culture was developed. The FGM with PWP (0.3%, w/v) and pectin (0.2%, w/v) had low syneresis (5.44 ± 0.92%), desirable viscosity (952.86 ± 61.52 mPa⋅s), and hardness (112.57 ± 3.23 g), which were comparable to a fermented cow milk. Sensory evaluation data showed that the FGM with PWP and pectin had higher scores of both flavor (4.41 ± 0.39) and taste (3.72 ± 0.34) than the sample without PWP. Chemical composition of both fermented goat and cow milk were analyzed. The protein content of goat and cow milk samples were 3.50% ± 0.12% and 3.28% ± 0.09% (w/w), respectively. Lactobacillus acidophilus population in both FGM samples remained above 10 6 CFU/g during the 1st 4-wk storage. There was a slight but no significant (P > 0.05) decrease in pH and TA during storage. Scanning electron microscopy micrographs displayed a compact and homogeneous protein network of the FGM with PWP and pectin. Polymerized whey protein may be a novel protein-based thickening agent for formulation of a set-type FGM with starter culture Kefir Mild 01. Fermented goat milk is an increasingly popular dairy product in the world. However, it is difficult to make set type fermented goat milk due to the smaller size and lower content of casein micelles in goat milk. A fermented goat milk with PWP (0.3%, w/v) and pectin (0.2%, w/v) was successfully developed in this study. The product fermented by Kefir Mild 01 starter culture had a similar taste with Kefir but no yeast or alcoholic exists. The new product would be a promising food in the market. © 2017 Institute of Food Technologists®.

Free Vibration of Fiber Composite Thin Shells in a Hot Environment

NASA Technical Reports Server (NTRS)

Gotsis, Pascal K.; Guptill, James D.

1995-01-01

Results are presented of parametric studies to assess the effects of various parameters on the free vibration behavior (natural frequencies) of (plus or minus theta)2, angle-ply fiber composite thin shells in a hot environment. These results were obtained by using a three-dimensional finite element structural analysis computer code. The fiber composite shell is assumed to be cylindrical and made from T-300 graphite fibers embedded in an intermediate-modulus high-strength matrix (IMHS). The residual stresses induced into the laminated structure during curing are taken into account. The following parameters are investigated: the length and the thickness of the shell, the fiber orientations, the fiber volume fraction, the temperature profile through the thickness of the laminate and the different ply thicknesses. Results obtained indicate that: the fiber orientations and the length of the laminated shell had significant effect on the natural frequencies. The fiber volume fraction, the laminate thickness and the temperature profile through the shell thickness had a weak effect on the natural frequencies. Finally, the laminates with different ply thicknesses had insignificant influence on the behavior of the vibrated laminated shell.

High-Fidelity Buckling Analysis of Composite Cylinders Using the STAGS Finite Element Code

NASA Technical Reports Server (NTRS)

Hilburger, Mark W.

2014-01-01

Results from previous shell buckling studies are presented that illustrate some of the unique and powerful capabilities in the STAGS finite element analysis code that have made it an indispensable tool in structures research at NASA over the past few decades. In particular, prototypical results from the development and validation of high-fidelity buckling simulations are presented for several unstiffened thin-walled compression-loaded graphite-epoxy cylindrical shells along with a discussion on the specific methods and user-defined subroutines in STAGS that are used to carry out the high-fidelity simulations. These simulations accurately account for the effects of geometric shell-wall imperfections, shell-wall thickness variations, local shell-wall ply-gaps associated with the fabrication process, shell-end geometric imperfections, nonuniform applied end loads, and elastic boundary conditions. The analysis procedure uses a combination of nonlinear quasi-static and transient dynamic solution algorithms to predict the prebuckling and unstable collapse response characteristics of the cylinders. Finally, the use of high-fidelity models in the development of analysis-based shell-buckling knockdown (design) factors is demonstrated.

Buckling test of a 3-meter-diameter corrugated graphite-epoxy ring-stiffened cylinder

NASA Technical Reports Server (NTRS)

Davis, R. C.

1982-01-01

A three m diameter by three m long corrugated cylindrical shell with external stiffening rings was tested to failure by buckling. The corrugation geometry for the graphite epoxy composite cylinder wall was optimized to withstand a compressive load producing an ultimate load intensity of 157.6 kN/m without buckling. The test method used to produce the design load intensity was to mount the specimen as a cantilevered cylinder and apply a pure bending moment to the end. A load introduction problem with the specimen was solved by using the BOSOR 4 shell of revolution computer code to analyze the shell and attached loading fixtures. The cylinder test loading achieved was 101 percent of design ultimate, and the resulting mass per unit of shell wall area was 1.96 kg/sq m.

Buckling Analysis for Stiffened Anisotropic Circular Cylinders Based on Sanders Nonlinear Shell Theory

NASA Technical Reports Server (NTRS)

Nemeth, Michael P.

2014-01-01

Nonlinear and bifurcation buckling equations for elastic, stiffened, geometrically perfect, right-circular cylindrical, anisotropic shells subjected to combined loads are presented that are based on Sanders' shell theory. Based on these equations, a three-parameter approximate Rayleigh-Ritz solution and a classical solution to the buckling problem are presented for cylinders with simply supported edges. Extensive comparisons of results obtained from these solutions with published results are also presented for a wide range of cylinder constructions. These comparisons include laminated-composite cylinders with a wide variety of shell-wall orthotropies and anisotropies. Numerous results are also given that show the discrepancies between the results obtained by using Donnell's equations and variants of Sanders' equations. For some cases, nondimensional parameters are identified and "master" curves are presented that facilitate the concise representation of results.

Setting up a clinic to assess children and young people for female genital mutilation.

PubMed

Hodes, Deborah; Creighton, Sarah M

2017-02-01

It is now mandatory for health, social care professionals and teachers to report to the police all under-18s where female genital mutilation (FGM) has been disclosed by the child or where physical signs of FGM are seen. Such referrals are likely to result in a request for medical examination. New multiagency statutory guidance sets out instructions for physical examination but provides no details how services should be set-up. This review gives practical guidance learnt from the first year of the UK's only dedicated children's FGM service. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

A generic double-curvature piezoelectric shell energy harvester: Linear/nonlinear theory and applications

NASA Astrophysics Data System (ADS)

Zhang, X. F.; Hu, S. D.; Tzou, H. S.

2014-12-01

Converting vibration energy to useful electric energy has attracted much attention in recent years. Based on the electromechanical coupling of piezoelectricity, distributed piezoelectric zero-curvature type (e.g., beams and plates) energy harvesters have been proposed and evaluated. The objective of this study is to develop a generic linear and nonlinear piezoelectric shell energy harvesting theory based on a double-curvature shell. The generic piezoelectric shell energy harvester consists of an elastic double-curvature shell and piezoelectric patches laminated on its surface(s). With a current model in the closed-circuit condition, output voltages and energies across a resistive load are evaluated when the shell is subjected to harmonic excitations. Steady-state voltage and power outputs across the resistive load are calculated at resonance for each shell mode. The piezoelectric shell energy harvesting mechanism can be simplified to shell (e.g., cylindrical, conical, spherical, paraboloidal, etc.) and non-shell (beam, plate, ring, arch, etc.) distributed harvesters using two Lamé parameters and two curvature radii of the selected harvester geometry. To demonstrate the utility and simplification procedures, the generic linear/nonlinear shell energy harvester mechanism is simplified to three specific structures, i.e., a cantilever beam case, a circular ring case and a conical shell case. Results show the versatility of the generic linear/nonlinear shell energy harvesting mechanism and the validity of the simplification procedures.

Three-dimensional spherical models of convection in the earth's mantle

NASA Technical Reports Server (NTRS)

Bercovici, Dave; Schubert, Gerald; Glatzmaier, Gary A.

1989-01-01

Three-dimensional spherical models of mantle convection in the earth reveal that upwelling cylindrical plumes and downwelling planar sheets are the primary features of mantle circulation. Thus subduction zones and descending sheetlike slabs in the mantle are fundamental characteristics of thermal convection in a spherical shell and are not merely the consequences of the rigidity of the slabs, which are cooler than the surrounding mantle. Cylindrical mantle plumes that cause hot spots such as Hawaii are probably the only form of active upwelling and are therefore not just secondary convective currents separate from the large-scale mantle circulation.

APPLICATION OF STATISTICAL ENERGY ANALYSIS TO VIBRATIONS OF MULTI-PANEL STRUCTURES.

DTIC Science & Technology

cylindrical shell are compared with predictions obtained from statistical energy analysis . Generally good agreement is observed. The flow of mechanical...the coefficients of proportionality between power flow and average modal energy difference, which one must know in order to apply statistical energy analysis . No

Nonlinear control of magnetic signatures

NASA Astrophysics Data System (ADS)

Niemoczynski, Bogdan

Magnetic properties of ferrite structures are known to cause fluctuations in Earth's magnetic field around the object. These fluctuations are known as the object's magnetic signature and are unique based on the object's geometry and material. It is a common practice to neutralize magnetic signatures periodically after certain time intervals, however there is a growing interest to develop real time degaussing systems for various applications. Development of real time degaussing system is a challenging problem because of magnetic hysteresis and difficulties in measurement or estimation of near-field flux data. The goal of this research is to develop a real time feedback control system that can be used to minimize magnetic signatures for ferrite structures. Experimental work on controlling the magnetic signature of a cylindrical steel shell structure with a magnetic disturbance provided evidence that the control process substantially increased the interior magnetic flux. This means near field estimation using interior sensor data is likely to be inaccurate. Follow up numerical work for rectangular and cylindrical cross sections investigated variations in shell wall flux density under a variety of ambient excitation and applied disturbances. Results showed magnetic disturbances could corrupt interior sensor data and magnetic shielding due to the shell walls makes the interior very sensitive to noise. The magnetic flux inside the shell wall showed little variation due to inner disturbances and its high base value makes it less susceptible to noise. This research proceeds to describe a nonlinear controller to use the shell wall data as an input. A nonlinear plant model of magnetics is developed using a constant tau to represent domain rotation lag and a gain function k to describe the magnetic hysteresis curve for the shell wall. The model is justified by producing hysteresis curves for multiple materials, matching experimental data using a particle swarm algorithm, and observing frequency effects. The plant model is used in a feedback controller and simulated for different materials as a proof of concept.

Efficient system for wavenumber-frequency analysis of underwater structures

NASA Astrophysics Data System (ADS)

Boober, Walter H.; Morton, David; Gedney, Charles; Abbot, Philip

1998-06-01

A watertight housing was developed to a low a scanning laser vibrometer (SLV) system to work underwater. Compared to other underwater optical measurement systems, this system offers distinct advantages, including ease of adaptation to a variety of teste, no requirement to be near tank windows, and a simplified rigging system. The system was recently sued to successfully conduct a wavenumber frequency evaluation of the vibratory response of a submerged cylindrical shell. The technical issues in developing the housing and assuring the integrity of the SLV accuracy during transition to underwater use will be discussed. Also, problems encountered in maximizing return signal strength, preparation of the shell, and the process of on-sight data transfer for quick-look wavenumber-frequency analysis while data are being acquired will be presented. The cylindrical shell was excited with 100 to 5000 Hz chirp signals by a 44 N shaker that was attached axially at the center of a bulkhead. A scan consisted of 3 columns with 64 measurement points per column. The shell was rotated 11.25 degrees and the scan repeated to collect an array of 32 by 64 equally spaced points totalling 6144 measurements. The time of data acquisition was about 11 hours. This underwater housing permitted the type of measurements that are not readily available with other systems. With most other techniques the collection time would have been significantly longer. The transfer functions between the velocities measured at each scan location and the shaker force signal were computed as functions of frequency. The transfer functions computed for the center scan columns were then transformed into the wavevector domain using a 2D FFT program. Preliminary results show that the shell response is concentrated near zero circumferential wavenumber, due to the axial symmetry of the driving force. Further, the maximum shell response is also concentrated near the ring frequency of the cylinder, at an axial wavenumber of about -20 rad/m.

Design and Manufacturing of Tow-Steered Composite Shells Using Fiber Placement

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey; Tatting, Brian F.; Smith, Brett H.; Stevens, Randy S.; Occhipiniti, Gina P.; Swift, Jonathan B.; Achary, David C.; Thornburgh, Robert P.

2009-01-01

Advanced composite shells that may offer the potential to improve the structural performance of future aircraft fuselage structures were developed under this joint NASA-industry collaborative effort. Two cylindrical shells with tailored, tow-steered layups and continuously varying fiber angle orientations were designed and built at the National Center for Advanced Manufacturing - Louisiana Partnership. The shells were fabricated from unidirectional IM7/8552 graphite-epoxy pre-preg slit tape material fiber-placed on a constant-diameter mandrel. Each shell had the same nominal 8-ply [plus or minus 45/plus or minus Theta]s layup, where the nominal fiber angle in the tow-steered plies varied continuously from 10 degrees along the crown to 45 degrees on each side, then back to 10 degrees on the keel. One shell was fabricated with all 24 tows placed during each pass of the fiber placement machine, resulting in many tow overlaps on the shell surface. The fiber placement machine's individual tow cut/restart capability was also used to manufacture a second shell with tow drops and a more uniform laminate thickness. This paper presents an overview of the detailed design and manufacturing processes for these shells, and discusses issues encountered during their fabrication and post-cure evaluation. Future plans for structural testing and analyses of the shells are also discussed.

On the mechanics of elastic lines in thin shells

NASA Astrophysics Data System (ADS)

Benet, Eduard; Vernerey, Franck

The deformation of soft shells in nature and engineering is often conditioned by the presence of lines whose mechanical properties are different from the shell. For instance, the deformation of tree leaves is conditioned by the presence of harder stems, and cell mitosis is driven by a stiffening line along its membrane. From an experimental standpoint, many groups have taken advantage of this feature to develop self-actuated shells with prescribed deformations. Examples include the polymerization of gels along certain lines, or the inclusion of stiffer lines via 3D printing. However, there is not yet a general continuum theory that accounts for this type of discontinuity within the membrane. Hence, we extend the general shell theory to account for the inclusion of a line that potentially induces jumps in stresses, couple stresses and moments, across its thickness. This is achieved via coupling the rod and the membrane deformations, and ensuring continuity of displacements. The model is then applied to three important problems: a constriction disc inside a shell of revolution, the induced twisting of a shell via the torsion of an embedded line, and the effect of an helicoidal line on the uni-axial deformation of a cylindrical shell. National Science Foundation CAREER award 1350090.

Forest genetic monitoring: an overview of concepts and definitions.

PubMed

Fussi, Barbara; Westergren, Marjana; Aravanopoulos, Filippos; Baier, Roland; Kavaliauskas, Darius; Finzgar, Domen; Alizoti, Paraskevi; Bozic, Gregor; Avramidou, Evangelia; Konnert, Monika; Kraigher, Hojka

2016-08-01

Safeguarding sustainability of forest ecosystems with their habitat variability and all their functions is of highest priority. Therefore, the long-term adaptability of forest ecosystems to a changing environment must be secured, e.g., through sustainable forest management. High adaptability is based on biological variation starting at the genetic level. Thus, the ultimate goal of the Convention on Biological Diversity (CBD) to halt the ongoing erosion of biological variation is of utmost importance for forest ecosystem functioning and sustainability. Monitoring of biological diversity over time is needed to detect changes that threaten these biological resources. Genetic variation, as an integral part of biological diversity, needs special attention, and its monitoring can ensure its effective conservation. We compare forest genetic monitoring to other biodiversity monitoring concepts. Forest genetic monitoring (FGM) enables early detection of potentially harmful changes of forest adaptability before these appear at higher biodiversity levels (e.g., species or ecosystem diversity) and can improve the sustainability of applied forest management practices and direct further research. Theoretical genetic monitoring concepts developed up to now need to be evaluated before being implemented on a national and international scale. This article provides an overview of FGM concepts and definitions, discusses their advantages and disadvantages, and provides a flow chart of the steps needed for the optimization and implementation of FGM. FGM is an important module of biodiversity monitoring, and we define an effective FGM scheme as consisting of an assessment of a forest population's capacity to survive, reproduce, and persist under rapid environmental changes on a long-term scale.

Foveolar gastric metaplasia of the duodenum: a frequent, so far neglected type of duodenal polyp.

PubMed

Sarbia, M; Sauer, G; Karimi, D; Berndt, R

2014-04-01

Foveolar gastric metaplasia of the duodenum (FGM) is considered as imperfect mucosal healing in the context of H. pylori gastritis and intake of NSAIDs or ASS.  Typical endoscopic findings are redness of the mucosa, erosion/ulcer and loss of mucosal folds. During diagnostic histological examinations we observed a frequent so far not described association of FGM with endoscopically observed duodenal polyps. The archives of two institutes of pathology with high gastroenterological workload (approximately 100 000 patients per year) were investigated for an association between "duodenal polyp" and "foveolar gastric metaplasia". In Institute 1, of 481 duodenal polyps 41 % were classified as FGM, 9 % as adenoma and 2 % as heterotopic gastric mucosa. In 48 % no histological correlate was present. In Institute 2, 217 cases of FGM were diagnosed. Of these, in 69 cases the endoscopic finding was "polyp" (32 %). In the other cases, the endoscopic findings were mucosal defect (18 %), redness/inflammation (16 %), suspicion for gastric heterotopia (5 %) and scar (3 %). In 26 % of cases no pathologic endoscopic finding was reported. Both groups of patients with FGM showed a similar distribution of age ranges (24 - 83 years and 16 - 88 years), median age (62 years and 61 years, respectively) and a dominance of male sex (both 1.5:1). In conclusion, foveolar gastric metaplasia is a frequent, so far neglected correlate of endoscopically detected duodenal polyps. © Georg Thieme Verlag KG Stuttgart · New York.

A multidisciplinary approach to clitoral reconstruction after female genital mutilation: the crucial role of counselling.

PubMed

De Schrijver, Lotte; Leye, Els; Merckx, Mireille

2016-08-01

Female genital mutilation (FGM) is becoming more widely seen in the West, due to immigration and population movement. Health services are being confronted with the need to provide care for women with FGM. One of the more recent trends is the provision of clitoral reconstruction. It remains unclear, however, what constitutes good practice with regard to this type of surgery. Based on a keynote presentation about reconstructive clitoral surgery, we briefly discuss the possible consequences of FGM and the findings from recent publications on clitoral reconstruction. Recognising individual differences in women, we suggest a multidisciplinary counselling model to provide appropriate care for women requesting clitoral reconstruction. The literature shows that FGM influences physical, mental and sexual health. Clitoral reconstructive surgery can lead to an increase in sexual satisfaction and orgasm in some, but not all, women. A multidisciplinary approach would enable a more satisfactory and individually tailored approach to care. The multidisciplinary team should consist of a midwife, a gynaecological surgeon, a psychologist-psychotherapist, a sexologist and a social worker. Comprehensive health counselling should be the common thread in this model of care. Our proposed care pathway starts with taking a thorough history, followed by medical, psychological and sexological consultations. Women with FGM requesting clitoral reconstruction might primarily be looking to improve their sexual life, to recover their identity and to reduce pain. Surgery may not always be the right answer. Thorough counselling that includes medical, psychological and sexual advice is therefore necessary as part of a multidisciplinary approach.

Nanowire Optoelectronics

NASA Astrophysics Data System (ADS)

Wang, Zhihuan; Nabet, Bahram

2015-12-01

Semiconductor nanowires have been used in a variety of passive and active optoelectronic devices including waveguides, photodetectors, solar cells, light-emitting diodes (LEDs), lasers, sensors, and optical antennas. We review the optical properties of these nanowires in terms of absorption, guiding, and radiation of light, which may be termed light management. Analysis of the interaction of light with long cylindrical/hexagonal structures with subwavelength diameters identifies radial resonant modes, such as Leaky Mode Resonances, or Whispering Gallery modes. The two-dimensional treatment should incorporate axial variations in "volumetric modes,"which have so far been presented in terms of Fabry-Perot (FP), and helical resonance modes. We report on finite-difference timedomain (FDTD) simulations with the aim of identifying the dependence of these modes on geometry (length, width), tapering, shape (cylindrical, hexagonal), core-shell versus core-only, and dielectric cores with semiconductor shells. This demonstrates how nanowires (NWs) form excellent optical cavities without the need for top and bottommirrors. However, optically equivalent structures such as hexagonal and cylindrical wires can have very different optoelectronic properties meaning that light management alone does not sufficiently describe the observed enhancement in upward (absorption) and downward transitions (emission) of light inNWs; rather, the electronic transition rates should be considered. We discuss this "rate management" scheme showing its strong dimensional dependence, making a case for photonic integrated circuits (PICs) that can take advantage of the confluence of the desirable optical and electronic properties of these nanostructures.

76 FR 78698 - Proposed Revocation of Permanent Variances

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-19

... cylindrical steel tanks. Construction of these tanks involves attaching curved steel plates together to form the outer surface of a tank. After attaching a horizontal layer (ring) of steel plates around the circumference of the existing shell, employees raise the scaffolds to attach the next ring of steel plates onto...

49 CFR 179.220-11 - Postweld heat treatment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Postweld heat treatment. 179.220-11 Section 179... Postweld heat treatment. (a) Postweld heat treatment of the inner container is not a specification requirement. (b) Postweld heat treatment of the cylindrical portions of the outer shell to which the anchorage...

Addressing female genital mutilation in Europe: a scoping review of approaches to participation, prevention, protection, and provision of services.

PubMed

Baillot, Helen; Murray, Nina; Connelly, Elaine; Howard, Natasha

2018-02-08

Public and policy attention to female genital mutilation (FGM) in diaspora communities has increased in Europe, but research remains limited and misinformation abounds. As a first step to addressing these issues, this study explored FGM prevention and response interventions in Europe, using a scoping literature review and key informant interviews. A scoping study design was selected, using Arksey and O'Malley's six-stage scoping framework to review identified sources. Key informant interviews were used to inform and add depth to literature findings. Findings were summarised thematically, guided by the Scottish Government's '4Ps' framework for tackling violence against women (i.e. participation, prevention, protection, providing services). Seventy literature sources, of 1095 screened, plus 16 individual and 3 group interview sources were included. Several countries have developed promising interventions supporting FGM resistance and recovery. However, gaps remain including community participation, professional knowledge and linkages, and evaluation of approaches. This scoping review is an initial attempt to describe available primary evidence on European initiatives responding to FGM. Further research is required to determine whether interventions are effective, while policy and practice development must be shaped and driven by the experiences, needs, and views of affected communities.

Plastic buckling. [post-bifurcation and imperfection sensitivity

NASA Technical Reports Server (NTRS)

Hutchinson, J. W.

1974-01-01

The present article is concerned mainly with the post-bifurcation and imperfection-sensitivity aspects of plastic buckling. A simple two-degree-of-freedom model is used to introduce post-bifurcation behavior and a second model illustrates features of the behavior of continuous solids and structures. Hill's bifurcation criterion for a class of three-dimensional solids is applied to the Donnell-Mushtari-Vlasov (DMV) theory of plates and shells. A general treatment of the initial post-bifurcation behavior of plates and shells is given within the context of the DMV theory. This is illustrated by problems involving columns and circular plates under radial compression. Numerical results are given for a column under axial compression, a circular plate under radial compression, and spherical and cylindrical shells.

Large-scale thermal energy storage using sodium hydroxide /NaOH/

NASA Technical Reports Server (NTRS)

Turner, R. H.; Truscello, V. C.

1977-01-01

A technique employing NaOH phase change material for large-scale thermal energy storage to 900 F (482 C) is described; the concept consists of 12-foot diameter by 60-foot long cylindrical steel shell with closely spaced internal tubes similar to a shell and tube heat exchanger. The NaOH heat storage medium fills the space between the tubes and outer shell. To charge the system, superheated steam flowing through the tubes melts and raises the temperature of NaOH; for discharge, pressurized water flows through the same tube bundle. A technique for system design and cost estimation is shown. General technical and economic properties of the storage unit integrated into a solar power plant are discussed.

Hierarchically assembled theranostic nanostructures for siRNA delivery and imaging applications.

PubMed

Shrestha, Ritu; Elsabahy, Mahmoud; Luehmann, Hannah; Samarajeewa, Sandani; Florez-Malaver, Stephanie; Lee, Nam S; Welch, Michael J; Liu, Yongjian; Wooley, Karen L

2012-10-24

Dual functional hierarchically assembled nanostructures, with two unique functions of carrying therapeutic cargo electrostatically and maintaining radiolabeled imaging agents covalently within separate component building blocks, have been developed via the supramolecular assembly of several spherical cationic shell cross-linked nanoparticles clustered around a central anionic shell cross-linked cylinder. The shells of the cationic nanoparticles and the hydrophobic core domain of the anionic central cylindrical nanostructure of the assemblies were utilized to complex negatively charged nucleic acids (siRNA) and to undergo radiolabeling, respectively, for potential theranostic applications. The assemblies exhibited exceptional cell transfection and radiolabeling efficiencies, providing an overall advantage over the individual components, which could each facilitate only one or the other of the functions.

Observation of hole accumulation in Ge/Si core/shell nanowires using off-axis electron holography.

PubMed

Li, Luying; Smith, David J; Dailey, Eric; Madras, Prashanth; Drucker, Jeff; McCartney, Martha R

2011-02-09

Hole accumulation in Ge/Si core/shell nanowires (NWs) has been observed and quantified using off-axis electron holography and other electron microscopy techniques. The epitaxial [110]-oriented Ge/Si core/shell NWs were grown on Si (111) substrates by chemical vapor deposition through the vapor-liquid-solid growth mechanism. High-angle annular-dark-field scanning transmission electron microscopy images and off-axis electron holograms were obtained from specific NWs. The excess phase shifts measured by electron holography across the NWs indicated the presence of holes inside the Ge cores. Calculations based on a simplified coaxial cylindrical model gave hole densities of (0.4 ± 0.2) /nm(3) in the core regions.

Blended-Wing-Body (BWB) Fuselage Structural Design for Weight Reduction

NASA Technical Reports Server (NTRS)

Mukhopadhyay, V.

2005-01-01

Structural analysis and design of efficient pressurized fuselage configurations for the advanced Blended-Wing-Body (BWB) flight vehicle is a challenging problem. Unlike a conventional cylindrical pressurized fuselage, stress level in a box type BWB fuselage is an order of magnitude higher, because internal pressure primarily results in bending stress instead of skin-membrane stress. In addition, resulting deformation of aerodynamic surface could significantly affect performance advantages provided by lifting body. The pressurized composite conformal multi-lobe tanks of X-33 type space vehicle also suffered from similar problem. In the earlier BWB design studies, Vaulted Ribbed Shell (VLRS), Flat Ribbed Shell (FRS); Vaulted shell Honeycomb Core (VLHC) and Flat sandwich shell Honeycomb Core (FLHC) concepts were studied. The flat and vaulted ribbed shell concepts were found most efficient. In a recent study, a set of composite sandwich panel and cross-ribbed panel were analyzed. Optimal values of rib and skin thickness, rib spacing, and panel depth were obtained for minimal weight under stress and buckling constraints. In addition, a set of efficient multi-bubble fuselage (MBF) configuration concept was developed. The special geometric configuration of this concept allows for balancing internal cabin pressure load efficiently, through membrane stress in inner-stiffened shell and inter-cabin walls, while the outer-ribbed shell prevents buckling due to external resultant compressive loads. The initial results from these approximate finite element analyses indicate progressively lower maximum stresses and deflections compared to the earlier study. However, a relative comparison of the FEM weight per unit floor area of the segment unit indicates that the unit weights are still relatively higher that the conventional B777 type cylindrical or A380 type elliptic fuselage design. Due to the manufacturing concern associated with multi-bubble fuselage, a Y braced box-type fuselage alternative with special resin-film injected (RFI) stitched carbon composite with foam-core was designed by Boeing under a NASA research contract for the 480 passenger version. It is shown that this configuration can be improved to a modified multi-bubble fuselage which has better stress distribution, for same material and dimension.

Acoustic and elastic waves in metamaterials for underwater applications

NASA Astrophysics Data System (ADS)

Titovich, Alexey S.

Elastic effects in acoustic metamaterials are investigated. Water-based periodic arrays of elastic scatterers, sonic crystals, suffer from low transmission due to the impedance and index mismatch of typical engineering materials with water. A new type of acoustic metamaterial element is proposed that can be tuned to match the acoustic properties of water in the quasi-static regime. The element comprises a hollow elastic cylindrical shell fitted with an optimized internal substructure consisting of a central mass supported by an axisymmetric distribution of elastic stiffeners, which dictate the shell's effective bulk modulus and density. The derived closed form scattering solution for this system shows that the subsonic flexural waves excited in the shell by the attachment of stiffeners are suppressed by including a sufficiently large number of such stiffeners. As an example of refraction-based wave steering, a cylindrical-to-plane wave lens is designed by varying the bulk modulus in the array according to the conformal mapping of a unit circle to a square. Elastic shells provide rich scattering properties, mainly due to their ability to support highly dispersive flexural waves. Analysis of flexural-borne waves on a pair of shells yields an analytical expression for the width of a flexural resonance, which is then used with the theory of multiple scattering to accurately predict the splitting of the resonance frequency. This analysis leads to the discovery of the acoustic Poisson-like effect in a periodic wave medium. This effect redirects an incident acoustic wave by 90° in an otherwise acoustically transparent sonic crystal. An unresponsive "deaf" antisymmetric mode locked to band gap boundaries is unlocked by matching Bragg scattering with a quadrupole flexural resonance of the shell. The dynamic effect causes normal unidirectional wave motion to strongly couple to perpendicular motion, analogous to the quasi-static Poisson effect in solids. The Poisson-like effect is demonstrated using the first flexural resonance of an acrylic shell. This represent a new type of material which cannot be accurately described as an effective acoustic medium. The study concludes with an analysis of a non-zero shear modulus in a pentamode cloak via the two-scale method with the shear modulus as the perturbation parameter.

Female genital mutilation in Djibouti.

PubMed

Martinelli, M; Ollé-Goig, J E

2012-12-01

The practice of female genital mutilation (we will use the latest definition adopted by WHO/UNFP: female genital mutilation/cutting or FGM/C) is still widespread in 28 African countries. The World Health Organisation (WHO) estimates that more than two million females undergo some form of genital mutilation every year. Its negative health impact and its ethical and human rights aspects have been discussed and attempts to eliminate it have been the objectives of several meetings promoted by national and international organisations thanks to an increased awareness related to FGM/C in those countries practicing it and also, maybe due to the number of Africans migrating to industrialized countries. We review the present situation in Djibouti, a small country in the Horn of Africa, where 98 % of the female population has suffered different forms of FGM/C.

A pressurized cylindrical shell with a fixed end which contains an axial part-through or through crack

NASA Technical Reports Server (NTRS)

Yahsi, O. S.; Erdogan, F.

1985-01-01

In this paper a cylindrical shell having a very stiff end plate or a flange is considered. It is assumed that near the end the cylinder contains an axial flow which may be modeled as a part-through surface crack or through crack. The primary objective is to study the effect of the end constraining on the stress intensity factor which is the main fracture mechanics parameter. The applied loads acting on the cylinder are assumed to be axisymmetric. Thus the crack problem under consideration is symmetric with respect to the plane of the crack and consequently only the mode I stress intensity factors are nonzero. With this limitation, the general perturbation problem for a cylinder with a built-in end containing an axial crack is considered. Reissner's shell theory is used to formulate the problem. The part-through crack problem is treated by using a line-spring model. In the case of a crack tip terminating at the fixed end it is shown that the integral equation of the shell problem has the same generalized Cauchy kernel as the corresponding plane stress elasticity problem. Even though the problem is formulated for a general surface crack profile and arbitrary crack surface tractions, the numerical results are obtained only for a semielliptic part-through axial crack located at the inside or outside surface of the cylinder and for internal pressure acting on the cylinder. The stress intensity factors are calculated and presented for a relatively wide range of dimensionless length parameters of the problem.

FASOR - A second generation shell of revolution code

NASA Technical Reports Server (NTRS)

Cohen, G. A.

1978-01-01

An integrated computer program entitled Field Analysis of Shells of Revolution (FASOR) currently under development for NASA is described. When completed, this code will treat prebuckling, buckling, initial postbuckling and vibrations under axisymmetric static loads as well as linear response and bifurcation under asymmetric static loads. Although these modes of response are treated by existing programs, FASOR extends the class of problems treated to include general anisotropy and transverse shear deformations of stiffened laminated shells. At the same time, a primary goal is to develop a program which is free of the usual problems of modeling, numerical convergence and ill-conditioning, laborious problem setup, limitations on problem size and interpretation of output. The field method is briefly described, the shell differential equations are cast in a suitable form for solution by this method and essential aspects of the input format are presented. Numerical results are given for both unstiffened and stiffened anisotropic cylindrical shells and compared with previously published analytical solutions.

Optimal design of geodesically stiffened composite cylindrical shells

NASA Technical Reports Server (NTRS)

Gendron, G.; Guerdal, Z.

1992-01-01

An optimization system based on the finite element code Computations Structural Mechanics (CSM) Testbed and the optimization program, Automated Design Synthesis (ADS), is described. The optimization system can be used to obtain minimum-weight designs of composite stiffened structures. Ply thickness, ply orientations, and stiffener heights can be used as design variables. Buckling, displacement, and material failure constraints can be imposed on the design. The system is used to conduct a design study of geodesically stiffened shells. For comparison purposes, optimal designs of unstiffened shells and shells stiffened by rings and stingers are also obtained. Trends in the design of geodesically stiffened shells are identified. An approach to include local stress concentrations during the design optimization process is then presented. The method is based on a global/local analysis technique. It employs spline interpolation functions to determine displacements and rotations from a global model which are used as 'boundary conditions' for the local model. The organization of the strategy in the context of an optimization process is described. The method is validated with an example.

Diffusion of external magnetic fields into the cone-in-shell target in the fast ignition

NASA Astrophysics Data System (ADS)

Sunahara, Atsushi; Morita, Hiroki; Johzaki, Tomoyuki; Nagatomo, Hideo; Fujioka, Shinsuke; Hassanein, Ahmed; Firex Project Team

2017-10-01

We simulated the diffusion of externally applied magnetic fields into cone-in-shell target in the fast ignition. Recently, in the fast ignition scheme, the externally magnetic fields up to kilo-Tesla is used to guide fast electrons to the high-dense imploded core. In order to study the profile of the magnetic field, we have developed 2D cylindrical Maxwell equation solver with Ohm's law, and carried out simulations of diffusion of externally applied magnetic fields into a cone-in-shell target. We estimated the conductivity of the cone and shell target based on the assumption of Saha-ionization equilibrium. Also, we calculated the temporal evolution of the target temperature heated by the eddy current driven by temporal variation of magnetic fields, based on the accurate equation of state. Both, the diffusion of magnetic field and the increase of target temperature interact with each other. We present our results of temporal evolution of the magnetic field and its diffusion into the cone and shell target.

Towards a Probabilistic Preliminary Design Criterion for Buckling Critical Composite Shells

NASA Technical Reports Server (NTRS)

Arbocz, Johann; Hilburger, Mark W.

2003-01-01

A probability-based analysis method for predicting buckling loads of compression-loaded laminated-composite shells is presented, and its potential as a basis for a new shell-stability design criterion is demonstrated and discussed. In particular, a database containing information about specimen geometry, material properties, and measured initial geometric imperfections for a selected group of laminated-composite cylindrical shells is used to calculate new buckling-load "knockdown factors". These knockdown factors are shown to be substantially improved, and hence much less conservative than the corresponding deterministic knockdown factors that are presently used by industry. The probability integral associated with the analysis is evaluated by using two methods; that is, by using the exact Monte Carlo method and by using an approximate First-Order Second- Moment method. A comparison of the results from these two methods indicates that the First-Order Second-Moment method yields results that are conservative for the shells considered. Furthermore, the results show that the improved, reliability-based knockdown factor presented always yields a safe estimate of the buckling load for the shells examined.

The crack problem in a specially orthotropic shell with double curvature

NASA Technical Reports Server (NTRS)

Delale, F.; Erdogan, F.

1983-01-01

The crack problem of a shallow shell with two nonzero curvatures is considered. It is assumed that the crack lies in one of the principal planes of curvature and the shell is under Mode I loading condition. The material is assumed to be specially orthotropic. After giving the general formulation of the problem the asymptotic behavior of the stress state around the crack tip is examined. The analysis is based on Reissner's transverse shear theory. Thus, as in the bending of cracked plates, the asymptotic results are shown to be consistent with that obtained from the plane elasticity solution of crack problems. Rather extensive numerical results are obtained which show the effect of material orthotropy on the stress intensity factors in cylindrical and spherical shells and in shells with double curvature. Other results include the stress intensity factors in isotropic toroidal shells with positive or negative curvature ratio, the distribution of the membrane stress resultant outside the crack, and the influence of the material orthotropy on the angular distribution of the stresses around the crack tip. Previously announced in STAR as N83-16782

The crack problem in a specially orthotropic shell with double curvature

NASA Technical Reports Server (NTRS)

Delale, F.; Erdogan, F.

1982-01-01

The crack problem of a shallow shell with two nonzero curvatures is considered. It is assumed that the crack lies in one of the principal planes of curvature and the shell is under Mode I loading condition. The material is assumed to be specially orthotropic. After giving the general formulation of the problem the asymptotic behavior of the stress state around the crack tip is examined. The analysis is based on Reissner's transverse shear theory. Thus, as in the bending of cracked plates, the asymptotic results are shown to be consistent with that obtained from the plane elasticity solution of crack problems. Rather extensive numerical results are obtained which show the effect of material orthotropy on the stress intensity factors in cylindrical and spherical shells and in shells with double curvature. Other results include the stress intensity factors in isotropic toroidal shells with positive or negative curvature ratio, the distribution of the membrane stress resultant outside the crack, and the influence of the material orthotropy on the angular distribution of the stresses around the crack tip.

The crack problem in a reinforced cylindrical shell

NASA Technical Reports Server (NTRS)

Yahsi, O. S.; Erdogan, F.

1986-01-01

In this paper a partially reinforced cylinder containing an axial through crack is considered. The reinforcement is assumed to be fully bonded to the main cylinder. The composite cylinder is thus modelled by a nonhomogeneous shell having a step change in the elastic properties at the z=0 plane, z being the axial coordinate. Using a Reissner type transverse shear theory the problem is reduced to a pair of singular integral equations. In the special case of a crack tip touching the bimaterial interface it is shown that the dominant parts of the kernels of the integral equations associated with both membrane loading and bending of the shell reduce to the generalized Cauchy kernel obtained for the corresponding plane stress case. The integral equations are solved and the stress intensity factors are given for various crack and shell dimensions. A bonded fiberglass reinforcement which may serve as a crack arrestor is used as an example.

The crack problem in a reinforced cylindrical shell

NASA Technical Reports Server (NTRS)

Yahsi, O. S.; Erdogan, F.

1986-01-01

A partially reinforced cylinder containing an axial through crack is considered. The reinforcement is assumed to be fully bonded to the main cylinder. The composite cylinder is thus modelled by a nonhomogeneous shell having a step change in the elastic properties at the z = 0 plane, z being the axial coordinate. Using a Reissner type transverse shear theory the problem is reduced to a pair of singular integral equations. In the special case of a crack tip touching the bimaterial interface it is shown that the dominant parts of the kernels of the integral equations associated with both membrane loading and bending of the shell reduce to the generalized Cauchy kernel obtained for the corresponding plane stress case. The integral equations are solved and the stress intensity factors are given for various crack and shell dimensions. A bonded fiberglass reinforcement which may serve as a crack arrestor is used as an example.

Crime in Nigeria: An Exploratory Analysis

DTIC Science & Technology

2012-11-02

and actual practice of Female Genital Mutilation and Cutting (FGM/C), early marriage, a substantial age gap between spouses (usually an older husband...prevention among 15-24 years-old, 2007 FGM: occurrence of Female Genital Mutilation /Cutting among daughters 15-49 yr old, 2007 Gender Parity... genital mutilation /cutting among 15-49 year old adults, 2007 AIDS Knowledge: Percentage with "comprehensive knowledge" of HIV/AIDS

What are the experiences of seeking, receiving and providing FGM-related healthcare? Perspectives of health professionals and women/girls who have undergone FGM: protocol for a systematic review of qualitative evidence.

PubMed

Evans, Catrin; Tweheyo, Ritah; McGarry, Julie; Eldridge, Jeanette; McCormick, Carol; Nkoyo, Valentine; Higginbottom, Gina Marie Awoko

2017-12-14

Female genital mutilation (FGM) is an issue of global concern. High levels of migration mean that healthcare systems in higher-income western countries are increasingly being challenged to respond to the care needs of affected communities. Research has identified significant challenges in the provision of, and access to, FGM-related healthcare. There is a lack of confidence and competence among health professionals in providing appropriate care, suggesting an urgent need for evidence-based service development in this area. This study will involve two systematic reviews of qualitative evidence to explore the experiences, needs, barriers and facilitators to seeking and providing FGM-related healthcare in high-income (Organisation for Economic Cooperation and Development) countries, from the perspectives of: (1) women and girls who have undergone FGM and (2) health professionals. Twelve databases including MEDLINE, EMBASE, PsycINFO, ASSIA, Web of Science, ERIC, CINAHL, and POPLINE will be searched with no limits on publication year. Relevant grey literature will be identified from digital sources and professional networks.Two reviewers will independently screen, select and critically appraise the studies. Study quality will be assessed using the Joanna Briggs Institute Qualitative Assessment and Review Instrument appraisal tool. Findings will be extracted into NVivo software. Synthesis will involve inductive thematic analysis, including in-depth reading, line by line coding of the findings, development of descriptive themes and re-coding to higher level analytical themes. Confidence in the review findings will be assessed using the CERQual approach. Findings will be integrated into a comprehensive set of recommendations for research, policy and practice. The syntheses will be reported as per the Enhancing Transparency in Reporting the Synthesis of Qualitative Research (ENTREQ) statement. Two reviews will be published in peer-reviewed journals and an integrated report disseminated at stakeholder engagement events. CRD42015030001: 2015 and CRD42015030004: 2015. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Holographic measurement of wave propagation in axi-symmetric shells

NASA Technical Reports Server (NTRS)

Evensen, D. A.; Aprahamian, R.; Jacoby, J. L.

1972-01-01

The report deals with the use of pulsed, double-exposure holographic interferometry to record the propagation of transverse waves in thin-walled axi-symmetric shells. The report is subdivided into sections dealing with: (1) wave propagation in circular cylindrical shells, (2) wave propagation past cut-outs and stiffeners, and (3) wave propagation in conical shells. Several interferograms are presented herein which show the waves reflecting from the shell boundaries, from cut-outs, and from stiffening rings. The initial response of the shell was nearly axi-symmetric in all cases, but nonsymmetric modes soon appeared in the radial response. This result suggests that the axi-symmetric response of the shell may be dynamically unstable, and thus may preferentially excite certain circumferential harmonics through parametric excitation. Attempts were made throughout to correlate the experimental data with analysis. For the most part, good agreement between theory and experiment was obtained. Occasional differences were attributed primarily to simplifying assumptions used in the analysis. From the standpoint of engineering applications, it is clear that pulsed laser holography can be used to obtain quantitative engineering data. Areas of dynamic stress concentration, stress concentration factors, local anomalies, etc., can be readily determined by holography.

Re-radiation of acoustic waves from the A0 wave on a submerged elastic shell

NASA Astrophysics Data System (ADS)

Ahyi, A. C.; Cao, Hui; Raju, P. K.; Überall, Herbert

2005-07-01

We consider evacuated thin semi-infinite shells immersed in a fluid, which may be either of cylindrical shape with a hemispherical shell endcap, or formed two-dimensionally by semi-infinite parallel plates joined together by a semi-cylinder. The connected shell portions are joined in a manner to satisfy continuity but with a discontinuous radius of curvature. Acoustic waves are considered incident along the axis of symmetry (say the z axis) onto the curved portion of the shell, where they, at the critical angle of coincidence, generate Lamb and Stoneley-type waves in the shell. Computations were carried out using a code developed by Cao et al. [Chinese J. Acoust. 14, 317 (1995)] and was used in order to computationally visualize the waves in the fluid that have been re-radiated by the shell waves a the critical angle. The frequency range was below that of the lowest Lamb wave, and only the A0 wave (and partly the S0 wave) was observed to re-radiate into the fluid under our assumptions. The results will be compared to experimental results in which the re-radiated waves are optically visualized by the Schardin-Cranz schlieren method. .

Dynamic acoustic radiation force acting on cylindrical shells: theory and simulations.

PubMed

Mitri, F G; Fatemi, M

2005-05-01

An object placed in an acoustic field is known to experience a force due to the transfer of momentum from the wave to the object itself. This force is known to be steady when the incident field is considered to be continuous with constant amplitude. One may define the dynamic (oscillatory) radiation force for a continuous wave-field whose intensity varies slowly with time. This paper extends the theory of the dynamic acoustic radiation force resulting from an amplitude-modulated progressive plane wave-field incident on solid cylinders to the case of solid cylindrical shells with particular emphasis on their thickness and contents of their hollow regions. A new factor corresponding to the dynamic radiation force is defined as Y(d) and stands for the dynamic radiation force per unit energy density and unit cross sectional surface. The results of numerical calculations are presented, indicating the ways in which the form of the dynamic radiation force function curves are affected by variations in the material mechanical parameters and by changes in the interior fluid inside the shell's hollow region. It was shown that the dynamic radiation force function Y(d) deviates from the static radiation force function for progressive waves Y(p) when the modulation frequency increases. These results indicate that the theory presented here is broader than the existing theory on cylinders.

Bell-Plesset effects in Rayleigh-Taylor instability of finite-thickness spherical and cylindrical shells

NASA Astrophysics Data System (ADS)

Velikovich, A. L.; Schmit, P. F.

2015-11-01

Bell-Plesset effects accounting for the time dependence of the radius, velocity and acceleration of the Rayleigh-Taylor-unstable surface are ubiquitous in the instability of spherical laser targets and magnetically driven cylindrical liners. We present an analytical model that, for an ideal incompressible fluid and small perturbation amplitudes, exactly accounts for the Bell-Plesset effects in finite-thickness targets and liners through acceleration and deceleration phases. We derive the time-dependent dispersion equations determining the ``instantaneous growth rate'' and demonstrate that by integrating this growth rate over time (the WKB approximation) we accurately evaluate the number of perturbation e-foldings during the acceleration phase. In the limit of the small target/liner thickness, we obtain the exact thin-shell perturbation equations and approximate thin-shell dispersion relations, generalizing the earlier results of Harris (1962), Ott (1972) and Bud'ko et al. (1989). This research was supported by the US DOE/NNSA (A.L.V.), and in part by appointment to the Sandia National Laboratories Truman Fellowship in National Security Science and Engineering (P.F.S.), which is part of the Laboratory Directed Research and Development (LDRD) Program, Project No. 165746, and sponsored by Sandia Corporation (a wholly owned subsidiary of Lockheed Martin Corporation) as Operator of Sandia National Laboratories under its U.S. Department of Energy Contract No. DE-AC04-94AL85000.

Eddy current heating in magnetic refrigerators

NASA Technical Reports Server (NTRS)

Kittel, Peter

1990-01-01

Eddy current heating can be a significant source of parasitic heating in low temperature magnetic refrigerators. To study this problem a technique to approximate the heating due to eddy currents has been developed. A formula is presented for estimating the heating within a variety of shapes commonly found in magnetic refrigerators. These shapes include circular, square, and rectangular rods; cylindrical and split cylindrical shells; wire loops; and 'coil foil. One set of components evaluated are different types of thermal radiation shields. This comparison shows that a simple split shield is almost as effective (only 23 percent more heating) as using a shield, with the same axial thermal conductivity, made of 'coil foil'.

Nonlinear analysis of thermally and electrically actuated functionally graded material microbeam.

PubMed

Li, Yingli; Meguid, S A; Fu, Yiming; Xu, Daolin

2014-02-08

In this paper, we provide a unified and self-consistent treatment of a functionally graded material (FGM) microbeam with varying thermal conductivity subjected to non-uniform or uniform temperature field. Specifically, it is our objective to determine the effect of the microscopic size of the beam, the electrostatic gap, the temperature field and material property on the pull-in voltage of the microbeam under different boundary conditions. The non-uniform temperature field is obtained by integrating the steady-state heat conduction equation. The governing equations account for the microbeam size by introducing an internal material length-scale parameter that is based on the modified couple stress theory. Furthermore, it takes into account Casimir and van der Waals forces, and the associated electrostatic force with the first-order fringing field effects. The resulting nonlinear differential equations were converted to a coupled system of algebraic equations using the differential quadrature method. The outcome of our work shows the dramatic effect and dependence of the pull-in voltage of the FGM microbeam upon the temperature field, its gradient for a given boundary condition. Specifically, both uniform and non-uniform thermal loading can actuate the FGM microbeam even without an applied voltage. Our work also reveals that the non-uniform temperature field is more effective than the uniform temperature field in actuating a FGM cantilever-type microbeam. For the clamped-clamped case, care must be taken to account for the effective use of thermal loading in the design of microbeams. It is also observed that uniform thermal loading will lead to a reduction in the pull-in voltage of a FGM microbeam for all the three boundary conditions considered.

Hepatitis B birth dose vaccination rates among children in Beijing: A comparison of local residents and first and second generation migrants

PubMed Central

Chen, Ruohan; Li, Youwei; Wangen, Knut Reidar; Nicholas, Stephen; Maitland, Elizabeth; Wang, Jian

2016-01-01

ABSTRACT Providing hepatitis B vaccine to all neonates within 24 hours of birth (Timely Birth Dose, TBD) is the key preventative measure to control perinatal hepatitis B virus infection. Previous Chinese studies of TBD only differentiated between migrant and non-migrant (local-born generation-LG) children. Our study is the first to stratify migrants in Beijing into first generation migrants (FGM) and second generation migrants (SGM). Based on a questionnaire survey of 2682 people in 3 Beijing villages, we identified 283 children aged 0–15 years, from 246 households, who were eligible for a TBD. Multinomial logistic regression and statistical analyses were used to examine factors explaining TBD rates for LG, FGM and SGM children. Surprisingly, the TBD for LG Beijing children was not significantly different from migrant children. But after stratifying migrant children into FGM and SGM, revealed significant TBD differences were revealed across LG, FGM and SGM according to domicile (p-value < 0.001, OR = 3.24), first vaccination covered by government policy (p-value < 0.05, OR = 3.24), mother's knowledge of hepatitis B (p-value < 0.05, OR = 1.01) and the government's HBV policy environment (p-value < 0.05, OR = 2.338). Birthplace (p-value = 0.002, OR = 6.21) and better policy environments (p-value = 0.01, OR = 2.80) were associated with higher TBD rate for LG and SGM children. Compared with FGM children, SGM had a significantly poorer TBD rate (Fisher exact test of chi-square = 0.013). We identified SGM as a special risk group; proposed Hukou reform to improve SGM TBD; and called for Beijing health authorities to match TBD rates in other provinces, especially by improving practices by health authorities and knowledge of parents. PMID:27043864

Hepatitis B birth dose vaccination rates among children in Beijing: A comparison of local residents and first and second generation migrants.

PubMed

Chen, Ruohan; Li, Youwei; Wangen, Knut Reidar; Nicholas, Stephen; Maitland, Elizabeth; Wang, Jian

2016-05-03

Providing hepatitis B vaccine to all neonates within 24 hours of birth (Timely Birth Dose, TBD) is the key preventative measure to control perinatal hepatitis B virus infection. Previous Chinese studies of TBD only differentiated between migrant and non-migrant (local-born generation-LG) children. Our study is the first to stratify migrants in Beijing into first generation migrants (FGM) and second generation migrants (SGM). Based on a questionnaire survey of 2682 people in 3 Beijing villages, we identified 283 children aged 0-15 years, from 246 households, who were eligible for a TBD. Multinomial logistic regression and statistical analyses were used to examine factors explaining TBD rates for LG, FGM and SGM children. Surprisingly, the TBD for LG Beijing children was not significantly different from migrant children. But after stratifying migrant children into FGM and SGM, revealed significant TBD differences were revealed across LG, FGM and SGM according to domicile (p-value < 0.001, OR = 3.24), first vaccination covered by government policy (p-value < 0.05, OR = 3.24), mother's knowledge of hepatitis B (p-value < 0.05, OR = 1.01) and the government's HBV policy environment (p-value < 0.05, OR = 2.338). Birthplace (p-value = 0.002, OR = 6.21) and better policy environments (p-value = 0.01, OR = 2.80) were associated with higher TBD rate for LG and SGM children. Compared with FGM children, SGM had a significantly poorer TBD rate (Fisher exact test of chi-square = 0.013). We identified SGM as a special risk group; proposed Hukou reform to improve SGM TBD; and called for Beijing health authorities to match TBD rates in other provinces, especially by improving practices by health authorities and knowledge of parents.

-dimensional thin shell wormhole with deformed throat can be supported by normal matter

NASA Astrophysics Data System (ADS)

Mazharimousavi, S. Habib; Halilsoy, M.

2015-06-01

From the physics standpoint the exotic matter problem is a major difficulty in thin shell wormholes (TSWs) with spherical/cylindrical throat topologies. We aim to circumvent this handicap by considering angle dependent throats in dimensions. By considering the throat of the TSW to be deformed spherical, i.e., a function of and , we present general conditions which are to be satisfied by the shape of the throat in order to have the wormhole supported by matter with positive density in the static reference frame. We provide particular solutions/examples to the constraint conditions.

Effect of Technological Tensioning on the Efficiency of Reinforcement of Pipelines with Composite Bands

NASA Astrophysics Data System (ADS)

Barkanov, E.; Beschetnikov, D.; Lvov, G.

2015-01-01

A mathematical model for the contact interaction of a cylindrical pipe with a composite band during its repair is constructed. A system of governing equations of the contact problem is formulated by using the Timoshenko theory of shells. An analysis of possible solutions is carried out for various combinations of geometric and elastic properties of shells. The possibility of pretension of a prepreg in order to improve the efficiency of repair is considered. The numerical results obtained allow one to establish the desired level of pretension for various repair situations.

Apparatus and method for aerodynamic levitation

NASA Technical Reports Server (NTRS)

Williamson, John W. (Inventor); al-Darwish, Mohamad M. (Inventor); Cashen, Grant E. (Inventor)

1993-01-01

An apparatus for the levitation of a liquid drop by a fluid flow comprising a profile generator, a fluid flow supply means operatively connected to the profile generator. The profile generator includes an elongate cylindrical shell in which is contained a profiling means for configuring the velocity profile of the fluid flow exiting the profile generator.

Implementation of the Graduated Cylindrical Shell Model for the Three-dimensional Reconstruction of Coronal Mass Ejections

NASA Astrophysics Data System (ADS)

Thernisien, A.

2011-06-01

The graduated cylindrical shell (GCS) model developed by Thernisien et al. has been used with the goal of studying the three-dimensional morphology, position, and kinematics of coronal mass ejections observed by coronagraphs. These studies focused more on the results rather than the details of the model itself. As more researchers begin to use the model, it becomes necessary to provide a deeper discussion on how it is derived, which is the purpose of this paper. The model is built using the following features and constraints: (1) the legs are conical, (2) the front is pseudo-circular, (3) the cross section is circular, and (4) it expands in a self-similar way. We derive the equation of the model from these constraints. We also show that the ice-cream cone model is a limit of the GCS when the two legs overlap completely. Finally, we provide formulae for the calculation of various geometrical dimensions, such as angular width and aspect ratio, as well as the pseudo-code that is used for its computer implementation.

A cylindrical shell with a stress-free end which contains an axial part-through or through crack

NASA Technical Reports Server (NTRS)

Erdogan, F.; Yahsi, O. S.

1985-01-01

The interaction problem of a through or a part through crack with a stress free boundary in a semi-infinite cylindrical shell is considered. It is assumed that the crack lies in a meridional plane which is a plane of symmetry with respect to the external loads as well as the geometry. The circular boundary of the semi-infinite cylinder is assumed to be stress free. By using a transverse shear theory the problem is formulated in terms of a system of singular integral equations. The line spring model is used to treat the part through crack problem. In the case of a through crack the interaction between the perturbed stress fields due to the crack and the free boundary is quite strong and there is a considerable increase in the stress intensity factors caused by the interaction. On the other hand in the problem of a surface crack the interaction appears to be much weaker and consequently the magnification in the stress intensity factors is much less significant.

A cylindrical shell with a stress-free end which contains an axial part-through or through crack

NASA Technical Reports Server (NTRS)

Erdogan, F.; Yahsi, O. S.

1983-01-01

The interaction problem of a through or a part through crack with a stress free boundary in a semi-infinite cylindrical shell is considered. It is assumed that the crack lies in a meridional plane which is a plane of symmetry with respect to the external loads as well as the geometry. The circular boundary of the semi-infinite cylinder is assumed to be stress free. By using a transverse shear theory the problem is formulated in terms of a system of singular integral equations. The line spring model is used to treat the part through crack problem. In the case of a through crack the interaction between the perturbed stress fields due to the crack and the free boundary is quite strong and there is a considerable increase in the stress intensity factors caused by the interaction. On the other hand in the problem of a surface crack the interaction appears to be much weaker and consequently the magnification in the stress intensity factors is much less significant.

Contamination control device

DOEpatents

Clark, Robert M.; Cronin, John C.

1977-01-01

A contamination control device for use in a gas-insulated transmission bus consisting of a cylindrical center conductor coaxially mounted within a grounded cylindrical enclosure. The contamination control device is electrically connected to the interior surface of the grounded outer shell and positioned along an axial line at the lowest vertical position thereon. The contamination control device comprises an elongated metallic member having a generally curved cross-section in a first plane perpendicular to the axis of the bus and having an arcuate cross-section in a second plane lying along the axis of the bus. Each opposed end of the metallic member and its opposing sides are tapered to form a pair of generally converging and downward sloping surfaces to trap randomly moving conductive particles in the relatively field-free region between the metallic member and the interior surface of the grounded outer shell. The device may have projecting legs to enable the device to be spot welded to the interior of the grounded housing. The control device provides a high capture probability and prevents subsequent release of the charged particles after the capture thereof.

A study of fluid-structure problems

NASA Astrophysics Data System (ADS)

Lam, Dennis Kang-Por

The stability of structures with and without fluid load is investigated. A method is developed for determining the fluid load in terms of added structural mass. Finite element methods are employed to study the buckling of a cylindrical shell under axial compression and liquid storage tanks under hydrodynamic load. Both linear and nonlinear analyses are performed. Diamond modes are found to be the possible postbuckling shapes of the cylindrical shell. Local buckling including elephant-foot buckle and diamond buckle are found for the liquid storage tank models. Comparison between the linear and nonlinear results indicates a substantial difference in buckling mode shapes, though the buckling loads are close to each other. The method for determining the hydrodynamic mass is applied to the impeller stage of a centrifugal pump. The method is based on a linear perturbation technique which assumes that the disturbance in the flow boundaries and velocities caused by the motion of the structure is small. A potential method is used to estimate the velocity flow field. The hydrodynamic mass is then obtained by calculating the total force which results from the pressure induced by a perturbation of the structure.

Acoustical imaging of high-frequency elastic responses of targets

NASA Astrophysics Data System (ADS)

Morse, Scot F.; Hefner, Brian T.; Marston, Philip L.

2002-05-01

Acoustical imaging was used to investigate high-frequency elastic responses to sound of two targets in water. The backscattering of broadband bipolar acoustic pulses by a truncated cylindrical shell was recorded over a wide range of tilt angles [S. F. Morse and P. L. Marston, ``Backscattering of transients by tilted truncated cylindrical shells: time-frequency identification of ray contributions from measurements,'' J. Acoust. Soc. Am. (in press)]. This data set was used to form synthetic aperture images of the target based on the data within different angular apertures. Over a range of viewing angles, the visibility of the cylinder's closest rear corner was significantly enhanced by the meridional flexural wave contribution to the backscattering. In another experiment, the time evolution of acoustic holographic images was used to explore the response of tilted elastic circular disks to tone bursts having frequencies of 250 and 300 kHz. For different tilt angles, specific responses that enhance the backscattering were identified from the time evolution of the images [B. T. Hefner and P. L. Marston, Acoust. Res. Lett. Online 2, 55-60 (2001)]. [Work supported by ONR.

Scattering of cylindrical electric field waves from an elliptical dielectric cylindrical shell

NASA Astrophysics Data System (ADS)

Urbanik, E. A.

1982-12-01

This thesis examines the scattering of cylindrical waves by large dielectric scatterers of elliptic cross section. The solution method was the method of moments using a Galerkin approach. Sinusoidal basis and testing functions were used resulting in a higher convergence rate. The higher rate of convergence made it possible for the program to run on the Aeronautical Systems Division's CYBER computers without any special storage methods. This report includes discussion on moment methods, solution of integral equations, and the relationship between the electric field and the source region or self cell singularity. Since the program produced unacceptable run times, no results are contained herein. The importance of this work is the evaluation of the practicality of moment methods using standard techniques. The long run times for a mid-sized scatterer demonstrate the impracticality of moment methods for dielectrics using standard techniques.

Development of an event-specific hydrolysis probe quantitative real-time polymerase chain reaction assay for Embrapa 5.1 genetically modified common bean (Phaseolus vulgaris).

PubMed

Treml, Diana; Venturelli, Gustavo L; Brod, Fábio C A; Faria, Josias C; Arisi, Ana C M

2014-12-10

A genetically modified (GM) common bean event, namely Embrapa 5.1, resistant to the bean golden mosaic virus (BGMV), was approved for commercialization in Brazil. Brazilian regulation for genetically modified organism (GMO) labeling requires that any food containing more than 1% GMO be labeled. The event-specific polymerase chain reaction (PCR) method has been the primary trend for GMO identification and quantitation because of its high specificity based on the flanking sequence. This work reports the development of an event-specific assay, named FGM, for Embrapa 5.1 detection and quantitation by use of SYBR Green or hydrolysis probe. The FGM assay specificity was tested for Embrapa 2.3 event (a noncommercial GM common bean also resistant to BGMV), 46 non-GM common bean varieties, and other crop species including maize, GM maize, soybean, and GM soybean. The FGM assay showed high specificity to detect the Embrapa 5.1 event. Standard curves for the FGM assay presented a mean efficiency of 95% and a limit of detection (LOD) of 100 genome copies in the presence of background DNA. The primers and probe developed are suitable for the detection and quantitation of Embrapa 5.1.

The use of functionally graded dental crowns to improve biocompatibility: a finite element analysis.

PubMed

Mahmoudi, Mojtaba; Saidi, Ali Reza; Hashemipour, Maryam Alsadat; Amini, Parviz

2018-02-01

In post-core crown restorations, the significant mismatch between stiffness of artificial crowns and dental tissues leads to stress concentration at the interfaces. The aim of the present study was to reduce the destructive stresses by using a class of inhomogeneous materials called functionally graded materials (FGMs). For the purpose of the study, a 3-dimentional computer model of a premolar tooth and its surrounding tissues were generated. A post-core crown restoration with various crown materials, homogenous and FGM materials, were simulated and analyzed by finite element method. Finite element and statistical analysis showed that, in case of oblique loading, a significant difference (p < 0.05) was found at the maximum von Mises stresses of the crown margin between FGM and homogeneous crowns. The maximum von Mises stresses of the crown margin generated by FGM crowns were lower than those generated by homogenous crowns (70.8 vs. 46.3 MPa) and alumina crown resulted in the highest von Mises stress at the crown margin (77.7 MPa). Crown materials of high modulus of elasticity produced high stresses at the cervical region. FGM crowns may reduce the stress concentration at the cervical margins and consequently reduce the possibility of fracture.

Environmental enrichment affects adrenocortical stress responses in the endangered black-footed ferret

USGS Publications Warehouse

Poessel, S.A.; Biggins, D.E.; Santymire, R.M.; Livieri, T.M.; Crooks, K.R.; Angeloni, L.

2011-01-01

Potential stressors of wildlife living in captivity, such as artificial living conditions and frequent human contact, may lead to a higher occurrence of disease and reduced reproductive function. One successful method used by wildlife managers to improve general well-being is the provision of environmental enrichment, which is the practice of providing animals under managed care with environmental stimuli. The black-footed ferret (Mustela nigripes) is a highly-endangered carnivore species that was rescued from extinction by removal of the last remaining individuals from the wild to begin an ex situ breeding program. Our goal was to examine the effect of environmental enrichment on adrenocortical activity in ferrets by monitoring fecal glucocorticoid metabolites (FGM). Results demonstrated that enrichment lowered FGM in juvenile male ferrets, while increasing it in adult females; enrichment had no effect on FGM in juvenile females and adult males. These results correspond with our findings that juvenile males interacted more with the enrichment items than did adult females. However, we did not detect an impact of FGM on the incidence of disease or on the ability of ferrets to become reproductive during the following breeding season. We conclude that an environmental enrichment program could benefit captive juvenile male ferrets by reducing adrenocortical activity. ?? 2011 Elsevier Inc.

Deinfibulation for treating urologic complications of type III female genital mutilation: A systematic review.

PubMed

Effa, Emmanuel; Ojo, Olumuyiwa; Ihesie, Austin; Meremikwu, Martin M

2017-02-01

Women and girls who have undergone type III female genital mutilation (FGM) may suffer urologic complications such as recurrent urinary tract infections, obstruction, stones, and incontinence. To assess the effectiveness of deinfibulation for preventing and treating urologic complications in women and girls living with FGM. The following major databases were searched from inception to August 2015: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, SCOPUS, Web of Science, and ClinicalTrials.gov without language restrictions. Randomized controlled studies (RCTs) or observational studies with controls were considered. We screened the results of the search independently for potentially relevant studies and applied inclusion and exclusion criteria for the full texts of the relevant studies. No RCTs were found. We found three case reports and a retrospective case review, all of which were excluded. There is no evidence on the use of deinfibulation to improve urologic complications among women with type III FGM. Current clinical practice may be informed by anecdotal evidence from case reports. Appropriate RCTs and observational studies with comparison groups in countries where FGM is common are needed. PROSPERO registration: CRD42015024901. © 2017 International Federation of Gynecology and Obstetrics. The World Health Organization retains copyright and all other rights in the manuscript of this article as submitted for publication.

The timing of female genital mutilation and the role of contralateral palpal insertions in the spider Cyclosa argenteoalba.

PubMed

Nakata, Kensuke

2017-11-01

Some male spiders exhibit female genital mutilation behaviour (FGM) by removing the female genital appendage (scape) to control the mating frequency of females. Female spiders have two, i.e. right and left, genital openings connected with separate spermathecae into which males transfer sperm successively using one pedipalp (secondary genitalia) at a time. Thus, males must complete at least two palpal insertions to fill both spermathecae, before FGM. The present study examined whether (i) scape removal is only associated with the second palpal insertion (one-action hypothesis) or (ii) two contralateral palpal insertions facilitate FGM, with each insertion cutting the basal part of the scape halfway (two-actions hypothesis). Experiments in which females were replaced after a male had made the first insertion did not support the one-action hypothesis, because scapes remained intact after the newly introduced virgin females received their first palpal insertion, which was the second insertion by the males. In comparison, mating experiments using two half-eunuchs (i.e. one of the palps of each male had been manually removed, forcing them to fill female spermatheca on one side only) supported the two-actions hypothesis. FGM was more frequent in females that received two contralateral palpal insertions than in females that received ipsilateral insertions.

The timing of female genital mutilation and the role of contralateral palpal insertions in the spider Cyclosa argenteoalba

PubMed Central

2017-01-01

Some male spiders exhibit female genital mutilation behaviour (FGM) by removing the female genital appendage (scape) to control the mating frequency of females. Female spiders have two, i.e. right and left, genital openings connected with separate spermathecae into which males transfer sperm successively using one pedipalp (secondary genitalia) at a time. Thus, males must complete at least two palpal insertions to fill both spermathecae, before FGM. The present study examined whether (i) scape removal is only associated with the second palpal insertion (one-action hypothesis) or (ii) two contralateral palpal insertions facilitate FGM, with each insertion cutting the basal part of the scape halfway (two-actions hypothesis). Experiments in which females were replaced after a male had made the first insertion did not support the one-action hypothesis, because scapes remained intact after the newly introduced virgin females received their first palpal insertion, which was the second insertion by the males. In comparison, mating experiments using two half-eunuchs (i.e. one of the palps of each male had been manually removed, forcing them to fill female spermatheca on one side only) supported the two-actions hypothesis. FGM was more frequent in females that received two contralateral palpal insertions than in females that received ipsilateral insertions. PMID:29291078

Behavioural and faecal glucocorticoid metabolite responses of single caging in six cats over 30 days

PubMed Central

Ellis, J. J.; Protopapadaki, V.; Stryhn, H.; Spears, J.; Cockram, M. S.

2014-01-01

Objectives The aim was to characterize the behaviour and faecal glucocorticoid metabolite (FGM) responses of six cats (Felis catus) to single caging for 30 days. Design In this observational study, changes in outcome measures were monitored with habituation to caging. Continuous focal observations of the activity, location in the cage, and posture were conducted from video recordings for one 24-hour period/week/cat. Cat-Stress-Scores were recorded daily. All faecal samples were collected for analysis of FGM. Results The percentage time spent eating increased, while percentage time spent grooming decreased, from week 1 to week 2. Cat-Stress-Score declined significantly from week 1 to week 2. FGM concentrations were significantly greater in week 1 than in week 5. A posthabituation time budget of the behaviour of the cats in the single cages showed that inactivity dominated the time budget and the cats were located on the shelf almost half of the time. Conclusions Results suggests that a shelf was a resource of value to the cats, and that its inclusion in enclosure design is important. Quantitative and qualitative behavioural data indicated that there was an initial stress response to caging that stabilised after the first week, while FGM concentration took longer to stabilise. PMID:26392880

Environmental enrichment affects adrenocortical stress responses in the endangered black-footed ferret.

PubMed

Poessel, Sharon A; Biggins, Dean E; Santymire, Rachel M; Livieri, Travis M; Crooks, Kevin R; Angeloni, Lisa

2011-07-01

Potential stressors of wildlife living in captivity, such as artificial living conditions and frequent human contact, may lead to a higher occurrence of disease and reduced reproductive function. One successful method used by wildlife managers to improve general well-being is the provision of environmental enrichment, which is the practice of providing animals under managed care with environmental stimuli. The black-footed ferret (Mustela nigripes) is a highly-endangered carnivore species that was rescued from extinction by removal of the last remaining individuals from the wild to begin an ex situ breeding program. Our goal was to examine the effect of environmental enrichment on adrenocortical activity in ferrets by monitoring fecal glucocorticoid metabolites (FGM). Results demonstrated that enrichment lowered FGM in juvenile male ferrets, while increasing it in adult females; enrichment had no effect on FGM in juvenile females and adult males. These results correspond with our findings that juvenile males interacted more with the enrichment items than did adult females. However, we did not detect an impact of FGM on the incidence of disease or on the ability of ferrets to become reproductive during the following breeding season. We conclude that an environmental enrichment program could benefit captive juvenile male ferrets by reducing adrenocortical activity. Copyright © 2011 Elsevier Inc. All rights reserved.

Investigation into the bistatic evolution of the acoustic scattering from a cylindrical shell using time-frequency analysis

NASA Astrophysics Data System (ADS)

Agounad, Said; Aassif, El Houcein; Khandouch, Younes; Maze, Gérard; Décultot, Dominique

2018-01-01

The time and frequency analyses of the acoustic scattering by an elastic cylindrical shell in bistatic method show that the arrival times of the echoes and the resonance frequencies of the elastic waves propagating in and around the cylindrical shell are a function of the bistatic angle, β, between the emitter and receiver transducers. The aim of this work is to explain the observed results in time and frequency domains using time-frequency analysis and graphical interpretations. The performance of four widely used time-frequency representations, the Smoothed Pseudo Wigner-Ville (SPWV), the Spectrogram (SP), the reassignment SPWV, and the reassignment SP, are studied. The investigation into the evolution of the time-frequency plane as a function of the bistatic angle β shows that there are the waves propagating in counter-clockwise direction (labeled wave+) and the waves which propagate in clockwise direction (labeled waves-). In this paper the A, S0, and A1 circumferential waves are investigated. The graphical interpretations are used to explain the formation mechanism of these waves and the acoustic scattering in monostatic and bistatic configurations. The delay between the echoes of the waves+ and those of the waves- is expressed in the case of the circumnavigating wave (Scholte-Stoneley wave). This study shows that the observed waves at β = 0 ° and β = 18 0 ° are the result of the constructive interferences between the waves+ and the waves-. A comparative study of the physical properties (group velocity dispersion and cut-off frequency) of the waves+, the waves- and the waves observed in monostatic configuration is conducted. Furthermore, it is shown that the ability of the time-frequency representation to highlight the waves+ and the waves- is very useful, for example, for the detection and the localization of defaults, the classification purposes, etc.

Method and apparatus for making superconductive magnet coils

DOEpatents

Borden, A.R.

1983-11-07

A curved, shell-type magnet coil, adapted to be used in a superconducting magnet, is wound by providing a mandrel having a tubular cylindrical mid-portion terminating at both ends in tapered end portions formed with longitudinal slots having flexible fingers therebetween. An elongated electrical conductor is wound around an elongated oval-shaped pole island engaged with the outside of the cylindrical mid-portion, to form a multiplicity of oval-shaped turns engaged with a 180-degree segment of the mandrel. The coil turns have longitudinal portions with curved portions therebetween, engaging the tapered end portions of the mandrel. Upon completion of the winding, tapered expansion members are fully inserted into the tapered end portions, to displace the flexible fingers outwardly into a cylindrical form and to displace the curved portions of the turns into a shape conforming to such cylindrical form while also exerting increased tension upon the turns to minimize draping of the turns and to enhance the mechanical integrity of the coil. A half cylinder clamp may then be employed to clamp the coil, whereupon the coil may be solidified by the use of an epoxy adhesive.

Design Considerations of Polishing Lap for Computer-Controlled Cylindrical Polishing Process

NASA Technical Reports Server (NTRS)

Khan, Gufran S.; Gubarev, Mikhail; Speegle, Chet; Ramsey, Brian

2010-01-01

The future X-ray observatory missions, such as International X-ray Observatory, require grazing incidence replicated optics of extremely large collecting area (3 m2) in combination with angular resolution of less than 5 arcsec half-power diameter. The resolution of a mirror shell depends ultimately on the quality of the cylindrical mandrels from which they are being replicated. Mid-spatial-frequency axial figure error is a dominant contributor in the error budget of the mandrel. This paper presents our efforts to develop a deterministic cylindrical polishing process in order to keep the mid-spatial-frequency axial figure errors to a minimum. Simulation studies have been performed to optimize the operational parameters as well as the polishing lap configuration. Furthermore, depending upon the surface error profile, a model for localized polishing based on dwell time approach is developed. Using the inputs from the mathematical model, a mandrel, having conical approximated Wolter-1 geometry, has been polished on a newly developed computer-controlled cylindrical polishing machine. We report our first experimental results and discuss plans for further improvements in the polishing process.

Method and apparatus for making superconductive magnet coils

DOEpatents

Borden, Albert R.

1985-01-01

A curved, shell-type magnet coil, adapted to be used in a superconducting magnet, is wound by providing a mandrel having a tubular cylindrical mid-portion terminating at both ends in tapered end portions formed with longitudinal slots having flexible fingers therebetween. An elongated electrical conductor is wound around an elongated oval-shaped pole island engaged with the outside of the cylindrical mid-portion, to form a multiplicity of oval-shaped turns engaged with a 180-degree segment of the mandrel. The coil turns have longitudinal portions with curved portions therebetween, engaging the tapered end portions of the mandrel. Upon completion of the winding, tapered expansion members are fully inserted into the tapered end portions, to displace the flexible fingers outwardly into a cylindrical form and to displace the curved portions of the turns into a shape conforming to such cylindrical form while also exerting increased tension upon the turns to minimize draping of the turns and to enhance the mechanical integrity of the coil. A half cylinder clamp may then be employed to clamp the coil, whereupon the coil may be solified by the use of an epoxy adhesive.

Asymptotic analysis of the shear strain effect on the wave characteristics of a multilayered cylindrical shell filled with fluid

NASA Astrophysics Data System (ADS)

Amenzade, R. Yu.; Kiiko, I. A.

2007-06-01

It is commonly assumed that the theory based on the Kirchhoff hypotheses describes the properties inherent in the wave processes occurring in shells filled with fluids. But there are several new effects that cannot be described by this theory (in particular, the appearance of new types of waves). In this paper, we present a linearized description of axisymmetric wave motion of a perfect incompressible fluid in a multilayered cylindrical shell with allowance for shear strain; the shell is assumed to be infinite and simply supported. This description is aimed at finding new mechanical effects and hence at estimating the influence of the multiple layers and the shear strain on the wave characteristics. In a sense, it generalizes and develops well-known studies of this type. Practice necessitates deriving equations constructed under the assumption that the physical and mechanical properties of the shell material are inhomogeneous along the thickness direction or the shell is multilayered; the development of refined theories (compared with the classical theory based on the Kirchhoff—Love straight normal hypothesis) is also inspired by practice. This is primarily related to the fact that multilayered thin-walled shells made of composite materials are used in various fields of technology. It is of interest to note that, as a result of long evolution, the phenomenon of being multilayered also predominates in living organisms. For example, this is typical of big blood vessels [1] (arteries and veins). In [2], on the basis of a three-dimensional variational principle of mixed type, the equations of motion and physical relations for elastic anisotropic shells rigidly inhomogeneous in the thickness direction are derived under the assumptions of the theory of thin shells and with shear strains taken into account. It is also noted that the case of multilayered shells can be modeled by introducing functions with integrable singularities. When studying wave propagation in deformable shells containing fluid, hydroelasticity problems arise; the solution of such problems is of both theoretical and practical importance. Of topical problems in this field, problems related to pulsating blood flow in big blood vessels [3] (the theory of pulse waves) are worth mentioning. The incentive for such studies is that they can help to understand the normal operation of the blood circulatory system, predict its reaction to variations, and propose methods for artificial intervention. Thus, diagnostics, surgery, and prosthesis are closely related to biomechanics. But the applied value of such problems is not bounded by their applications in hemodynamics. They are also very important in technology because of the wide use of systems of fluid and gas transportation through pipelines with corrosion-resistant coating.

Buckling of Thin Cylindrical Shell Subject to Uniform External Pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forasassi, G.; Lo Frano, R.

2006-07-01

The buckling of cylindrical shells under uniform external pressure loading has been widely investigated. In general, when tubes are subjected to external pressure, collapse is initiated by yielding, but interaction with instability is significant, in that imperfections associated with fabrication of shells reduce the load bearing capacity by a significant amount even when thickness is considerable. A specific buckling analysis is used to predict collapse failure of long pressure vessels and pipelines when they are subjected to external over-pressure. The problem of buckling for variable load conditions is relevant for the optimisation of several Nuclear Power Plant applications as, formore » instance, the IRIS (International Reactor Innovative and Secure) LWR integrated Steam Generator (SG) tubes. In this paper, we consider in addition to the usual assumptions of thin shell, homogeneous and isotropic material, also the tube geometric imperfections and plastic deformations that may affect the limit load. When all those conditions are considered at present, a complete theoretical analysis was not founding the literature. At Pisa University a research activity is being carried out on the buckling of thin walled metal specimen, with reference to several geometries and two different stainless steel materials. A test equipment (with the necessary data acquisition facility), suitable for carrying out many test on this issue, as well as numerical models implemented on the MARC FEM code, were set up. In this report, the results of the performed analyses of critical pressure load determination with different numerical and experimental approaches are presented. The numerical results obtained are compared with the experimental results, for the same geometry and loading conditions, showing a good agreement between these two approaches. (authors)« less

Properties of Concrete partially replaced with Coconut Shell as Coarse aggregate and Steel fibres in addition to its Concrete volume

NASA Astrophysics Data System (ADS)

Kalyana Chakravarthy, P. R.; Janani, R.; Ilango, T.; Dharani, K.

2017-03-01

Cement is a binder material with various composition of Concrete but instantly it posses low tensile strength. The study deals with mechanical properties of that optimized fiber in comparison with conventional and coconut shell concrete. The accumulation of fibers arbitrarily dispersed in the composition increases the resistance to cracking, deflection and other serviceability conditions substantially. The steel fiber in extra is one of the revision in coconut shell concrete and the outcome of steel fiber in coconut shell concrete was to investigate and compare with the conventional concrete. For the given range of steel fibe from 0.5 to 2.0%, 12 beams and 36 cylindrical specimens were cast and tested to find the mechanical properties like flexural strength, split tensile, impact resistance and the modulus of elasticity of both conventional and coconut shell concrete has been studied and the test consequences are compared with the control concrete and coconut shell concrete for M25 Grade. It is fulfilled that, the steel fibers used in this venture has shown significant development in all the properties of conventional and coconut shell concrete while compared to controlled conventional and coconut shell concrete like, Flexural strength by 6.67 % for 1.0 % of steel fiber in conventional concrete and by 5.87 % for 1.5 % of steel fiber in coconut shell concrete.

Mechanical and microstructural characterization of W–Cu FGM fabricated by one-step sintering method through PM route

NASA Astrophysics Data System (ADS)

Gupta, Rajat; Kumar, Rohit; Chaubey, A. K.; Kanpara, Shailesh; Khirwadkar, S. S.

2018-03-01

Five layer W-Cu functionally graded material (FGM) for components in nuclear fusion application was fabricated by a one-step resistance sintering process, known as spark plasma sintering (SPS). In this study effect of sintering temperature (Ts) on physical, mechanical and surface property was investigated. Detailed microstructural study revealed that the graded structure of the composite layers with varying composition from 0 to 100 wt% W and Cu in opposite directions could be well densified after the SPS process. It also indicates that the fine microstructure within functionally graded layers can be maintained because of short sintering time. The sample sintered at 1050°C shows more than 90% theoretical density, hardness greater than 239±5 Hv and excellent surface scratch resistance. The result demonstrates that SPS is promising and more suitable process for fabrication of W-Cu FGM.

Fashion garment manufacturing - FGM and cyclability theory

NASA Astrophysics Data System (ADS)

Mendes, F. D.; Dos Santos, M. C. L.

2017-10-01

This article, derived from an ongoing research, presents the possibilities of reducing the inappropriate disposal of textile residues generated by the fabric cutting sector of the Fashion Garment Manufacturing (FGM). The raw material used is very varied, resulting in a large number of productive processes. FGM produces clothing that has as its main features a short life cycle, a high rate of diversification and differentiation, and small production batches, resulting in few similar parts. The production process is differentiated according to the characteristics of the fabric and the look of the garment. During the production process, at least 10% of textile waste is generated during the cutting process, which is constantly discarded in an inadequate way. The Cyclability theory is researched aiming at the possibility of reduction in the generation of waste and elimination of inappropriate disposal. The case study presents the action research carried out in three small Brazilian companies to study the applicability of the Cyclability theory.

Moisture Determination of Nuts and Dry Fruits using a Capacitance Sensor

USDA-ARS?s Scientific Manuscript database

Impedance (Z), and phase angle (') of a cylindrical parallel-plate capacitor with in-shell peanuts between the plates was measured earlier, using a CI meter (Chari’s Impedance meter), at 1 and 5 MHz . Capacitance C, was derived from Z and ', and using the C, ', and Z values of a set of peanuts whos...

Analytical model for vibration prediction of two parallel tunnels in a full-space

NASA Astrophysics Data System (ADS)

He, Chao; Zhou, Shunhua; Guo, Peijun; Di, Honggui; Zhang, Xiaohui

2018-06-01

This paper presents a three-dimensional analytical model for the prediction of ground vibrations from two parallel tunnels embedded in a full-space. The two tunnels are modelled as cylindrical shells of infinite length, and the surrounding soil is modelled as a full-space with two cylindrical cavities. A virtual interface is introduced to divide the soil into the right layer and the left layer. By transforming the cylindrical waves into the plane waves, the solution of wave propagation in the full-space with two cylindrical cavities is obtained. The transformations from the plane waves to cylindrical waves are then used to satisfy the boundary conditions on the tunnel-soil interfaces. The proposed model provides a highly efficient tool to predict the ground vibration induced by the underground railway, which accounts for the dynamic interaction between neighbouring tunnels. Analysis of the vibration fields produced over a range of frequencies and soil properties is conducted. When the distance between the two tunnels is smaller than three times the tunnel diameter, the interaction between neighbouring tunnels is highly significant, at times in the order of 20 dB. It is necessary to consider the interaction between neighbouring tunnels for the prediction of ground vibrations induced underground railways.

Problems in understanding the structure and assembly of viruses

DOE Office of Scientific and Technical Information (OSTI.GOV)

King, J.

1997-12-01

Though viruses infect the cells of all groups of animals, plants, and microorganisms, their structures follow a limited number of general themes; spherical or cylindrical shells built of hundreds of repeated protein subunits enclosing a nucleic acid - DNA or RNA - genome. Since the 1960s it has been known that the protein shells of spherical viruses in fact conform to icosahedral symmetry or to subtle deviations from icosahedral symmetry. The construction of the shell lattices and the transformations they go through in the different stages of the viral life cycle are not fully understood. The shells contain the nucleicmore » in a highly condensed state, of unknown coiling/organization. Features of the well studied bacterial viruses will be reviewed, with examples from adenoviruses, herpesviruses, poliovirus, and HIV. The emergence of new viral disease has led to increased interest in the development of agents which interfere with virus reproduction at the level of the assembly or function of the organized particle. Recently computational approaches to the problem of virus assembly have made important contributions to clarifying shell assembly processes. 1 ref.« less

Facet-selective nucleation and conformal epitaxy of Ge shells on Si nanowires

DOE PAGES

Nguyen, Binh -Minh; Swartzentruber, Brian; Ro, Yun Goo; ...

2015-10-08

Knowledge of nanoscale heteroepitaxy is continually evolving as advances in material synthesis reveal new mechanisms that have not been theoretically predicted and are different than what is known about planar structures. In addition to a wide range of potential applications, core/shell nanowire structures offer a useful template to investigate heteroepitaxy at the atomistic scale. We show that the growth of a Ge shell on a Si core can be tuned from the theoretically predicted island growth mode to a conformal, crystalline, and smooth shell by careful adjustment of growth parameters in a narrow growth window that has not been exploredmore » before. In the latter growth mode, Ge adatoms preferentially nucleate islands on the {113} facets of the Si core, which outgrow over the {220} facets. Islands on the low-energy {111} facets appear to have a nucleation delay compared to the {113} islands; however, they eventually coalesce to form a crystalline conformal shell. As a result, synthesis of epitaxial and conformal Si/Ge/Si core/multishell structures enables us to fabricate unique cylindrical ring nanowire field-effect transistors, which we demonstrate to have steeper on/off characteristics than conventional core/shell nanowire transistors.« less

Theoretical and experimental design studies for the Atmospheric General Circulation Experiment

NASA Technical Reports Server (NTRS)

Fowlis, W. W.; Hathaway, D. H.; Miller, T. L.; Roberts, G. O.; Kopecky, K. J.

1985-01-01

The major criterion for the Atmospheric General Circulation Experiment (AGCE) design is that it be possible to realize strong baroclinic instability in the spherical configuration chosen. A configuration was selected in which a hemispherical shell of fluid is subjected to latitudinal temperature gradients on its spherical boundaries and the latitudinal boundaries are insulators. Work in the laboratory with a cylindrical version of this configuration revealed more instabilities than baroclinic instability. Since researchers fully expect these additional instabilities to appear in the spherical configuration also, they decided to continue the laboratory cylindrical annulus studies. Four flow regimes were identified: an axisymmetric Hadley circulation, boundary layer convection, baroclinic waves and deep thermal convection. Regime diagrams were prepared.

Mixed finite-difference scheme for free vibration analysis of noncircular cylinders

NASA Technical Reports Server (NTRS)

Noor, A. K.; Stephens, W. B.

1973-01-01

A mixed finite-difference scheme is presented for the free-vibration analysis of simply supported closed noncircular cylindrical shells. The problem is formulated in terms of eight first-order differential equations in the circumferential coordinate which possess a symmetric coefficient matrix and are free of the derivatives of the elastic and geometric characteristics of the shell. In the finite-difference discretization, two interlacing grids are used for the different fundamental unknowns in such a way as to avoid averaging in the difference-quotient expressions used for the first derivative. The resulting finite-difference equations are symmetric. The inverse-power method is used for obtaining the eigenvalues and eigenvectors.

Compression strength of composite primary structural components

NASA Technical Reports Server (NTRS)

Johnson, Eric R.

1992-01-01

A status report of work performed during the period May 1, 1992 to October 31, 1992 is presented. Research was conducted in three areas: delamination initiation in postbuckled dropped-ply laminates; stiffener crippling initiated by delamination; and pressure pillowing of an orthogonally stiffened cylindrical shell. The geometrically nonlinear response and delamination initiation of compression-loaded dropped-ply laminates is analyzed. A computational model of the stiffener specimens that includes the capability to predict the interlaminar response at the flange free edge in postbuckling is developed. The distribution of the interacting loads between the stiffeners and the shell wall, particularly at the load transfer at the stiffener crossing point, is determined.

On the Buckling of Imperfect Anisotropic Shells with Elastic Edge Supports Under Combined Loading Part I:. Pt. 1; Theory and Numerical Analysis

NASA Technical Reports Server (NTRS)

Arbocz, Johann; Hol, J. M. A. M.; deVries, J.

1998-01-01

A rigorous solution is presented for the case of stiffened anisotropic cylindrical shells with general imperfections under combined loading, where the edge supports are provided by symmetrical or unsymmetrical elastic rings. The circumferential dependence is eliminated by a truncated Fourier series. The resulting nonlinear 2-point boundary value problem is solved numerically via the "Parallel Shooting Method". The changing deformation patterns resulting from the different degrees of interaction between the given initial imperfections and the specified end rings are displayed. Recommendations are made as to the minimum ring stiffnesses required for optimal load carrying configurations.

Antepartum or intrapartum deinfibulation for childbirth in women with type III female genital mutilation: A systematic review and meta-analysis.

PubMed

Esu, Ekpereonne; Udo, Atim; Okusanya, Babasola O; Agamse, David; Meremikwu, Martin M

2017-02-01

There remains no consensus on the best timing of deinfibulation in women with type III female genital mutilation (FGM). To conduct a systematic review of the effects of antepartum or intrapartum deinfibulation on childbirth outcomes in women with type III FGM. The following major databases were searched: Cochrane Central Register for Controlled Trials (CENTRAL), MEDLINE, Scopus, Web of Science, and ClinicalTrials.gov, from inception until August 2015 without any language restrictions. Studies of pregnant women or girls with type III FGM who were deinfibulated antepartum or intrapartum were included. Two team members independently screened and collected data. Quality of evidence was assessed using GRADE. Summary odds ratios and proportions were calculated when possible. There is no evidence of a significant difference between antepartum and intrapartum deinfibulation for obstetric outcomes such as duration of labor, perineal lacerations, episiotomies, postpartum hemorrhage, and cesarean deliveries. Outcomes in women living with type III FGM and those who have undergone deinfibulation were not statistically different; however, trends show a benefit for deinfibulation. All studies were underpowered to detect statistical differences. Larger studies are required to have full confidence in these findings. CRD42015024464. © 2017 International Federation of Gynecology and Obstetrics. The World Health Organization retains copyright and all other rights in the manuscript of this article as submitted for publication.

Providing information about the consequences of female genital mutilation to healthcare providers caring for women and girls living with female genital mutilation: A systematic review.

PubMed

Oringanje, Chioma M; Okoro, Anthony; Nwankwo, Ogonna N; Meremikwu, Martin M

2017-02-01

The persistence of female genital mutilation (FGM) in some countries, despite an overall decline in the prevalence of the practice, calls for improvement in the capacity of healthcare workers and institutions to provide optimal care for this population. To determine the impact of providing information on FGM and its consequences to healthcare providers on their attitudes toward FGM, and quality of care and patient satisfaction. The following major databases were searched from inception to August 2015: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, SCOPUS, Web of Science, and ClinicalTrials.gov, without language restrictions. Controlled studies were included based on use of objective measures. Two team members independently screened and collected data. Relative risks and proportions were calculated and evidence assessed using the GRADE (Grade of Recommendation, Assessment, Development and Evaluation) approach. One study was identified. Based on this study there was no evidence to suggest change in healthcare provider outcomes after the intervention. Despite a comprehensive search, only one study of low methodological quality was included. This precludes a definitive conclusion regarding the impact of providing information on FGM to healthcare providers. More research is needed. CRD42015024570. © 2017 International Federation of Gynecology and Obstetrics. The World Health Organization retains copyright and all other rights in the manuscript of this article as submitted for publication.

Sexual counselling for treating or preventing sexual dysfunction in women living with female genital mutilation: A systematic review.

PubMed

Okomo, Uduak; Ogugbue, Miriam; Inyang, Elizabeth; Meremikwu, Martin M

2017-02-01

Female sexual dysfunction is the persistent or recurring decrease in sexual desire or arousal, the difficulty or inability to achieve an orgasm, and/or the feeling of pain during sexual intercourse. Impaired sexual function can occur with all types of female genital mutilation (FGM) owing to the structural changes, pain, or traumatic memories associated with the procedure. To conduct a systematic review of randomized and nonrandomized studies into the effects of sexual counseling with or without genital lubricants on the sexual function of women living with FGM. Cochrane Central Register of Controlled Trials, MEDLINE, African Index Medicus, SCOPUS, LILACS, CINAHL, ClinicalTrials.gov, Pan African Clinical Trials Registry, and other databases were searched to August 2015. The reference lists of retrieved studies were checked for reports of additional studies, and lead authors contacted for additional data. Studies of girls and women living with any type of FGM who received counselling interventions for sexual dysfunction were included. No relevant studies that addressed the objective of the review were identified. Despite a comprehensive search, the authors could not find evidence of the effects of sexual counseling on the sexual function of women living with FGM. Studies assessing this intervention are needed. CRD42015024593. © 2017 International Federation of Gynecology and Obstetrics. The World Health Organization retains copyright and all other rights in the manuscript of this article as submitted for publication.

Higher-Order Theory for Functionally Graded Materials

NASA Technical Reports Server (NTRS)

Aboudi, J.; Pindera, M. J.; Arnold, Steven M.

2001-01-01

Functionally graded materials (FGM's) are a new generation of engineered materials wherein the microstructural details are spatially varied through nonuniform distribution of the reinforcement phase(s). Engineers accomplish this by using reinforcements with different properties, sizes, and shapes, as well as by interchanging the roles of the reinforcement and matrix phases in a continuous manner (ref. 1). The result is a microstructure that produces continuously or discretely changing thermal and mechanical properties at the macroscopic or continuum scale. This new concept of engineering the material's microstructure marks the beginning of a revolution both in the materials science and mechanics of materials areas since it allows one, for the first time, to fully integrate the material and structural considerations into the final design of structural components. Functionally graded materials are ideal candidates for applications involving severe thermal gradients, ranging from thermal structures in advanced aircraft and aerospace engines to computer circuit boards. Owing to the many variables that control the design of functionally graded microstructures, full exploitation of the FGM's potential requires the development of appropriate modeling strategies for their response to combined thermomechanical loads. Previously, most computational strategies for the response of FGM's did not explicitly couple the material's heterogeneous microstructure with the structural global analysis. Rather, local effective or macroscopic properties at a given point within the FGM were first obtained through homogenization based on a chosen micromechanics scheme and then subsequently used in a global thermomechanical analysis.

Non-Deterministic Dynamic Instability of Composite Shells

NASA Technical Reports Server (NTRS)

Chamis, Christos C.; Abumeri, Galib H.

2004-01-01

A computationally effective method is described to evaluate the non-deterministic dynamic instability (probabilistic dynamic buckling) of thin composite shells. The method is a judicious combination of available computer codes for finite element, composite mechanics, and probabilistic structural analysis. The solution method is incrementally updated Lagrangian. It is illustrated by applying it to thin composite cylindrical shell subjected to dynamic loads. Both deterministic and probabilistic buckling loads are evaluated to demonstrate the effectiveness of the method. A universal plot is obtained for the specific shell that can be used to approximate buckling loads for different load rates and different probability levels. Results from this plot show that the faster the rate, the higher the buckling load and the shorter the time. The lower the probability, the lower is the buckling load for a specific time. Probabilistic sensitivity results show that the ply thickness, the fiber volume ratio and the fiber longitudinal modulus, dynamic load and loading rate are the dominant uncertainties, in that order.

Large deflection elastic-plastic dynamic response of stiffened shells of revolution

NASA Technical Reports Server (NTRS)

Stricklin, J. A.; Haisler, W. E.; Vonriesemann, W. A.; Leick, R. D.; Hunsaker, B.; Saczalski, K. J.

1972-01-01

The formulation and check out porblems for a computer code DYNAPLAS, which analyzes the large deflection elastic-plastic dynamic response of stiffened shells of revolution, are presented. The formulation for special discretization is by the finite element method with finite differences being used for the evaluation of the pseudo forces due to material and geometric nonlinearities. Time integration is by the Houbolt method. The stiffeners may be due to concentrated or distributed eccentric rings and spring supports at arbitrary angles around the circumference of the elements. Check out porblems include the comparison of solutions from DYNAPLAS with experimental and other computer solutions for rings, conical and cylindrical shells and a curved panel. A hypothetical submarine including stiffeners and missile tube is studied under a combination of hydrostatic and dynamically applied asymmetrical pressure loadings.

The electronic structure and effective excitonic g factors of GaAs/GaMnAs core-shell nanowires

NASA Astrophysics Data System (ADS)

Li, Dong-Xiao; Xiong, Wen

2017-12-01

We calculate the electronic structures of cylindrical GaAs/GaMnAs core-shell nanowires in the magnetic field based on the eight-band effective-mass kṡp theory, and it is found that the hole states can present strong band-crossings. The probability densities of several lowest electron states and highest hole states at the Γ point are analyzed, and strangely, the distribution of the electron states are more complex than that of the hole states. Furthermore, the components of the electron states will change substantially as the increase of the radius R, which are almost unchanged for the hole states. A very interesting phenomenon is that the effective excitonic g factors gex can be tuned from a large positive value for GaMnAs nanowires to a small negative value for GaAs nanowires, and gex of GaAs nanowires and GaMnAs nanowires will vary slightly and greatly, respectively as the increase of the magnetic field. Meanwhile, we can obtain large gex in cylindrical GaAs/GaMnAs core-shell nanowires when the small magnetic field, the large concentration of manganese ions, the small core radius and the small radius are chosen. Another important result is also found that the radiative intensities of two σ polarized lights can be separated gradually by decreasing the core radius Rc , which can be used to detect two σ polarized lights in the experiment.

Analysis of nematode mechanics by piezoresistive displacement clamp

PubMed Central

Park, Sung-Jin; Goodman, Miriam B.; Pruitt, Beth L.

2007-01-01

Studying animal mechanics is critical for understanding how signals in the neuromuscular system give rise to behavior and how force-sensing organs and sensory neurons work. Few techniques exist to provide forces and displacements appropriate for such studies. To address this technological gap, we developed a metrology using piezoresistive cantilevers as force–displacement sensors coupled to a feedback system to apply and maintain defined load profiles to micrometer-scale animals. We show that this system can deliver forces between 10−8 and 10−3 N across distances of up to 100 μm with a resolution of 12 nN between 0.1 Hz and 100 kHz. We use this new metrology to show that force–displacement curves of wild-type nematodes (Caenorhabditis elegans) are linear. Because nematodes have approximately cylindrical bodies, this finding demonstrates that nematode body mechanics can be modeled as a cylindrical shell under pressure. Little is known about the relative importance of hydrostatic pressure and shell mechanics, however. We show that dissipating pressure by cuticle puncture or decreasing it by hyperosmotic shock has only a modest effect on stiffness, whereas defects in the dpy-5 and lon-2 genes, which alter body shape and cuticle proteins, decrease and increase stiffness by 25% and 50%, respectively. This initial analysis of C. elegans body mechanics suggests that shell mechanics dominates stiffness and is a first step in understanding how body mechanics affect locomotion and force sensing. PMID:17962419

Primates Living Outside Protected Habitats Are More Stressed: The Case of Black Howler Monkeys in the Yucatán Peninsula

PubMed Central

Rangel-Negrín, Ariadna; Coyohua-Fuentes, Alejandro; Chavira, Roberto; Canales-Espinosa, Domingo; Dias, Pedro Américo D.

2014-01-01

The non-invasive monitoring of glucocorticoid hormones allows for the assessment of the physiological effects of anthropogenic disturbances on wildlife. Variation in glucocorticoid levels of the same species between protected and unprotect areas seldom has been measured, and the available evidence suggests that this relationship may depend on species-specific habitat requirements and biology. In the present study we focused on black howler monkeys (Alouatta pigra), a canopy-dwelling primate species, as a case study to evaluate the physiological consequences of living in unprotected areas, and relate them with intragroup competition and competition with extragroup individuals. From February 2006 to September 2007 we collected 371 fecal samples from 21 adults belonging to five groups (two from protected and three from unprotected areas) in Campeche, Mexico. We recorded agonistic interactions within groups and encounters with other groups (1,200 h of behavioral observations), and determined fecal glucocorticoid metabolite (FGM) concentrations with radioimmunoassays. We used linear mixed models and Akaike's information criterion to choose the best model explaining variation in FGM concentrations between protected and unprotected areas calculated from five categorical variables: habitat type (protected vs. unprotected), participation in agonistic interactions, intergroup encounters, sex and female reproductive state, and season. The best model included habitat type, the interaction between habitat type and agonism, and the interaction between habitat type and season. FGM concentrations were higher in unprotected habitats, particularly when individuals were involved in agonistic interactions; seasonal variation in FGM concentrations was only detected in protected habitats. High FGM concentrations in black howler monkeys living in unprotected habitats are associated with increased within-group food competition and probably associated with exposure to anthropogenic stressors and overall food scarcity. Because persistent high GC levels can be detrimental to health and fitness, populations living in disturbed unprotected areas may not be viable in the long-term. PMID:25375243

Primates living outside protected habitats are more stressed: the case of black howler monkeys in the Yucatán Peninsula.

PubMed

Rangel-Negrín, Ariadna; Coyohua-Fuentes, Alejandro; Chavira, Roberto; Canales-Espinosa, Domingo; Dias, Pedro Américo D

2014-01-01

The non-invasive monitoring of glucocorticoid hormones allows for the assessment of the physiological effects of anthropogenic disturbances on wildlife. Variation in glucocorticoid levels of the same species between protected and unprotect areas seldom has been measured, and the available evidence suggests that this relationship may depend on species-specific habitat requirements and biology. In the present study we focused on black howler monkeys (Alouatta pigra), a canopy-dwelling primate species, as a case study to evaluate the physiological consequences of living in unprotected areas, and relate them with intragroup competition and competition with extragroup individuals. From February 2006 to September 2007 we collected 371 fecal samples from 21 adults belonging to five groups (two from protected and three from unprotected areas) in Campeche, Mexico. We recorded agonistic interactions within groups and encounters with other groups (1,200 h of behavioral observations), and determined fecal glucocorticoid metabolite (FGM) concentrations with radioimmunoassays. We used linear mixed models and Akaike's information criterion to choose the best model explaining variation in FGM concentrations between protected and unprotected areas calculated from five categorical variables: habitat type (protected vs. unprotected), participation in agonistic interactions, intergroup encounters, sex and female reproductive state, and season. The best model included habitat type, the interaction between habitat type and agonism, and the interaction between habitat type and season. FGM concentrations were higher in unprotected habitats, particularly when individuals were involved in agonistic interactions; seasonal variation in FGM concentrations was only detected in protected habitats. High FGM concentrations in black howler monkeys living in unprotected habitats are associated with increased within-group food competition and probably associated with exposure to anthropogenic stressors and overall food scarcity. Because persistent high GC levels can be detrimental to health and fitness, populations living in disturbed unprotected areas may not be viable in the long-term.

Using the Female Sexual Function Index (FSFI) to evaluate sexual function in women with genital mutilation undergoing surgical reconstruction: a pilot prospective study.

PubMed

Vital, Mathilde; de Visme, Sophie; Hanf, Matthieu; Philippe, Henri-Jean; Winer, Norbert; Wylomanski, Sophie

2016-07-01

Few prospective studies have evaluated sexual function in women with female genital mutilation by cutting (FGM/C) before and after clitoral reconstructive surgery, and none used a validated questionnaire. A validated questionnaire, the Female Sexual Function Index (FSFI) was used for the first time, to assess the impact of reconstructive surgery on sexual function in women with female genital mutilation/cutting (FGM/C) before and after clitoral reconstructive surgery. Women with FGM/C consulting at the Nantes University Hospital for clitoral reconstruction between 2013 and 2014 were prospectively included. All patients completed a questionnaire at inclusion, describing their social, demographic, and FGM/C characteristics. They were also asked to complete the FSFI as well as a questionnaire about clitoral sensations, symptoms of depression or anxiety, and self-esteem before and 3 and 6 months after the surgery. Paired Wilcoxon and McNemar tests were used to compare data. Of the 12 women included, 9 (75%) had type II mutilations. Results showed a global sexual dysfunction (median FSFI summary score=17) before surgery. Clitoral sensations were absent in 8 women (67%). Six months after surgery, all FSFI dimensions except lubrication had improved significantly (median FSFI summary score=29, P=0.009). Ten women had clitoral sensations, and 11 (92%) were satisfied with their surgery. This study shows that 6 months after clitoral reconstructive surgery, women reported a multidimensional positive improvement in their sexual function. The FSFI is a promising tool for routine standardized assessment of the sexual function of women with FGM/C for determining appropriate management and assessing it. Larger studies with validated questionnaires assessing self-esteem, depression, and body image are also needed to develop an integrative approach and to provide evidence-based recommendations about management of these women. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Management of painful clitoral neuroma after female genital mutilation/cutting.

PubMed

Abdulcadir, Jasmine; Tille, Jean-Christophe; Petignat, Patrick

2017-02-08

Traumatic neuromas are the result of regenerative disorganized proliferation of the proximal portion of lesioned nerves. They can exist in any anatomical site and are responsible for neuropathic pain. Post-traumatic neuromas of the clitoris have been described as an uncommon consequence of female genital mutilation/cutting (FGM/C). FGM/C involves partial or total removal of the female genital organs for non-therapeutic reasons. It can involve cutting of the clitoris and can cause psychological, sexual, and physical complications. We aimed to evaluate the symptoms and management of women presenting with a clitoral neuroma after female genital mutilation/cutting (FGM/C). We identified women who attended our specialized clinic for women with FGM/C who were diagnosed with a traumatic neuroma of the clitoris between April 1, 2010 and June 30, 2016. We reviewed their medical files and collected socio-demographic, clinical, surgical, and histopathological information. Seven women were diagnosed with clitoral neuroma. Six attended our clinic to undergo clitoral reconstruction, and three of these suffered from clitoral pain. The peri-clitoral fibrosis was removed during clitoral reconstruction, which revealed neuroma of the clitoris in all six subjects. Pain was ameliorated after surgery. The seventh woman presented with a visible and palpable painful clitoral mass diagnosed as a neuroma. Excision of the mass ameliorated the pain. Sexual function improved in five women. One was not sexually active, and one had not yet resumed sex. Post-traumatic clitoral neuroma can be a consequence of FGM/C. It can cause clitoral pain or be asymptomatic. In the case of pain symptoms, effective treatment is neuroma surgical excision, which can be performed during clitoral reconstruction. Surgery should be considered as part of multidisciplinary care. The efficacy of neuroma excision alone or during clitoral reconstruction to treat clitoral pain should be further assessed among symptomatic women.

Compression strength of composite primary structural components

NASA Technical Reports Server (NTRS)

Johnson, Eric R.

1993-01-01

Two projects are summarized. The first project is entitled 'Stiffener Crippling Inititated by Delaminations' and its objective is to develop a computational model of the stiffener specimens that includes the capability to predict the interlaminar stress response at the flange free edge in postbuckling. The second is entitled 'Pressure Pillowing of an Orthogonally Stiffened Cylindrical Shell'. A paper written on this project is included.

Drilling side holes from a borehole

NASA Technical Reports Server (NTRS)

Collins, E. R., Jr.

1980-01-01

Machine takes long horizontal stratum samples from confines of 21 cm bore hole. Stacked interlocking half cylindrical shells mate to form rigid thrust tube. Drive shaft and core storage device is flexible and retractable. Entire machine fits in 10 meter length of steel tube. Machine could drill drainage or ventilation holes in coal mines, or provide important information for geological, oil, and geothermal surveys.

The physics of sliding cylinders and curling rocks

NASA Astrophysics Data System (ADS)

Penner, A. Raymond

2001-03-01

The lateral deflection of a rotating cylindrical shell sliding on one of its ends is considered and both theoretical and experimental results are presented. The coefficient of kinetic friction between a curling rock and an ice surface is then derived and compared with experiment. Current models of the motion of a curling rock are discussed and an alternate hypothesis is presented.

HL-20 structural design comparison - Conformal shell versus cylindrical crew compartment

NASA Technical Reports Server (NTRS)

Bush, Lance B.; Wahls, Deborah M.; Robinson, James C.

1993-01-01

Extensive studies have been performed at NASA Langley Research Center (LaRC) on personnel launch systems (PLS) concepts. The primary mission of a PLS is the transport of Space Station crew members from Earth to the Space Station and return. The NASA LaRC PLS studies have led to the design of a lifting body configuration named the HL-20. In this study, two different HL-20 structural configurations are evaluated. The two configurations are deemed the conformal shell and the cylindrical crew compartment. The configurations are based on two different concerns for maintenance and operations. One configuration allows for access to subsystems while on-orbit from the interior, while the other allows for easy access to the subsystems during ground maintenance and operations. For each concept, the total structural weight required to sustain the applied loads is quantified through a structural evaluation. Structural weight for both configurations is compared along with the particular attributes of each. Analyses of both configurations indicate no appreciable weight or load relief advantage of one concept over the other. Maintainability and operability, therefore become the primary discriminator, leading to a choice of a crew compartment configuration.

Investigation on imperfection sensitivity of composite cylindrical shells using the nonlinearity reduction technique and the polynomial chaos method

NASA Astrophysics Data System (ADS)

Liang, Ke; Sun, Qin; Liu, Xiaoran

2018-05-01

The theoretical buckling load of a perfect cylinder must be reduced by a knock-down factor to account for structural imperfections. The EU project DESICOS proposed a new robust design for imperfection-sensitive composite cylindrical shells using the combination of deterministic and stochastic simulations, however the high computational complexity seriously affects its wider application in aerospace structures design. In this paper, the nonlinearity reduction technique and the polynomial chaos method are implemented into the robust design process, to significantly lower computational costs. The modified Newton-type Koiter-Newton approach which largely reduces the number of degrees of freedom in the nonlinear finite element model, serves as the nonlinear buckling solver to trace the equilibrium paths of geometrically nonlinear structures efficiently. The non-intrusive polynomial chaos method provides the buckling load with an approximate chaos response surface with respect to imperfections and uses buckling solver codes as black boxes. A fast large-sample study can be applied using the approximate chaos response surface to achieve probability characteristics of buckling loads. The performance of the method in terms of reliability, accuracy and computational effort is demonstrated with an unstiffened CFRP cylinder.

Soft lubrication: The elastohydrodynamics of nonconforming and conforming contacts

NASA Astrophysics Data System (ADS)

Skotheim, J. M.; Mahadevan, L.

2005-09-01

We study the lubrication of fluid-immersed soft interfaces and show that elastic deformation couples tangential and normal forces and thus generates lift. We consider materials that deform easily, due to either geometry (e.g., a shell) or constitutive properties (e.g., a gel or a rubber), so that the effects of pressure and temperature on the fluid properties may be neglected. Four different system geometries are considered: a rigid cylinder moving parallel to a soft layer coating a rigid substrate; a soft cylinder moving parallel to a rigid substrate; a cylindrical shell moving parallel to a rigid substrate; and finally a cylindrical conforming journal bearing coated with a thin soft layer. In addition, for the particular case of a soft layer coating a rigid substrate, we consider both elastic and poroelastic material responses. For all these cases, we find the same generic behavior: there is an optimal combination of geometric and material parameters that maximizes the dimensionless normal force as a function of the softness parameter η =hydrodynamicpressure/elasticstiffness=surfacedeflection/gapthickness, which characterizes the fluid-induced deformation of the interface. The corresponding cases for a spherical slider are treated using scaling concepts.

Shell morphology and Raman spectra of epitaxial Ge-SixGe1-x and Si-SixGe1-x core-shell nanowires

NASA Astrophysics Data System (ADS)

Wen, Feng; Dillen, David C.; Kim, Kyounghwan; Tutuc, Emanuel

2017-06-01

We investigate the shell morphology and Raman spectra of epitaxial Ge-SixGe1-x and Si-SixGe1-x core-shell nanowire heterostructures grown using a combination of a vapor-liquid-solid (VLS) growth mechanism for the core, followed by in-situ epitaxial shell growth using ultra-high vacuum chemical vapor deposition. Cross-sectional transmission electron microscopy reveals that the VLS growth yields cylindrical Ge, and Si nanowire cores grown along the ⟨111⟩, and ⟨110⟩ or ⟨112⟩ directions, respectively. A hexagonal cross-sectional morphology is observed for Ge-SixGe1-x core-shell nanowires terminated by six {112} facets. Two distinct morphologies are observed for Si-SixGe1-x core-shell nanowires that are either terminated by four {111} and two {100} planes associated with the ⟨110⟩ growth direction or four {113} and two {111} planes associated with the ⟨112⟩ growth direction. We show that the Raman spectra of Si- SixGe1-x are correlated with the shell morphology thanks to epitaxial growth-induced strain, with the core Si-Si mode showing a larger red shift in ⟨112⟩ core-shell nanowires compared to their ⟨110⟩ counterparts. We compare the Si-Si Raman mode value with calculations based on a continuum elasticity model coupled with the lattice dynamic theory.

Gravitational radiation from a cylindrical naked singularity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakao, Ken-ichi; Morisawa, Yoshiyuki

We construct an approximate solution which describes the gravitational emission from a naked singularity formed by the gravitational collapse of a cylindrical thick shell composed of dust. The assumed situation is that the collapsing speed of the dust is very large. In this situation, the metric variables are obtained approximately by a kind of linear perturbation analysis in the background Morgan solution which describes the motion of cylindrical null dust. The most important problem in this study is what boundary conditions for metric and matter variables should be imposed at the naked singularity. We find a boundary condition that allmore » the metric and matter variables are everywhere finite at least up to the first order approximation. This implies that the spacetime singularity formed by this high-speed dust collapse is very similar to that formed by the null dust and the final singularity will be a conical one. Weyl curvature is completely released from the collapsed dust.« less

Stable Tearing and Buckling Responses of Unstiffened Aluminum Shells with Long Cracks

NASA Technical Reports Server (NTRS)

Starnes, James H., Jr.; Rose, Cheryl A.

1999-01-01

The results of an analytical and experimental study of the nonlinear response of thin, unstiffened, aluminum cylindrical shells with a long longitudinal crack are presented. The shells are analyzed with a nonlinear shell analysis code that accurately accounts for global and local structural response phenomena. Results are presented for internal pressure and for axial compression loads. The effect of initial crack length on the initiation of stable crack growth and unstable crack growth in typical shells subjected to internal pressure loads is predicted using geometrically nonlinear elastic-plastic finite element analyses and the crack-tip-opening angle (CTOA) fracture criterion. The results of these analyses and of the experiments indicate that the pressure required to initiate stable crack growth and unstable crack growth in a shell subjected to internal pressure loads decreases as the initial crack length increases. The effects of crack length on the prebuckling, buckling and postbuckling responses of typical shells subjected to axial compression loads are also described. For this loading condition, the crack length was not allowed to increase as the load was increased. The results of the analyses and of the experiments indicate that the initial buckling load and collapse load for a shell subjected to axial compression loads decrease as the initial crack length increases. Initial buckling causes general instability or collapse of a shell for shorter initial crack lengths. Initial buckling is a stable local response mode for longer initial crack lengths. This stable local buckling response is followed by a stable postbuckling response, which is followed by general or overall instability of the shell.

Stable Tearing and Buckling Responses of Unstiffened Aluminum Shells with Long Cracks

NASA Technical Reports Server (NTRS)

Starnes, James H., Jr.; Rose, Cheryl A.

1998-01-01

The results of an analytical and experimental study of the nonlinear response of thin, unstiffened, aluminum cylindrical shells with a long longitudinal crack are presented. The shells are analyzed with a nonlinear shell analysis code that accurately accounts for global and local structural response phenomena. Results are presented for internal pressure and for axial compression loads. The effect of initial crack length on the initiation of stable crack growth and unstable crack growth in typical shells subjected to internal pressure loads is predicted using geometrically nonlinear elastic-plastic finite element analyses and the crack-tip-opening angle (CTOA) fracture criterion. The results of these analyses and of the experiments indicate that the pressure required to initiate stable crack growth and unstable crack growth in a shell subjected to internal pressure loads decreases as the initial crack length increases. The effects of crack length on the prebuckling, buckling and postbuckling responses of typical shells subjected to axial compression loads are also described. For this loading condition, the crack length was not allowed to increase as the load was increased. The results of the analyses and of the experiments indicate that the initial buckling load and collapse load for a shell subjected to axial compression loads decrease as the initial crack length increases. Initial buckling causes general instability or collapse of a shell for shorter initial crack lengths. Initial buckling is a stable local response mode for longer initial crack lengths. This stable local buckling response is followed by a stable postbuckling response, which is followed by general or overall instability of the shell.