DETERMINATION OF CRITICAL ROTATIONAL SPEED OF CIRCULAR SAWS FROM NATURAL FREQUENCIES OF ANNULAR PLATE WITH ANALOGOUS DIMENSIONS

Directory of Open Access Journals (Sweden)

Ante Skoblar

2016-03-01

Full Text Available It is suitable to reduce thickness of circular saw when trying to enhance usability of wood raw material, but reducing thickness also causes reduction of permissible rotational speed which reduces sawing speed. If one increase circular saw rotational speed over permissible one the quality of machined surfaces will reduce because of enhanced vibrations. Permissible rotational speed can be calculated from critical rotational speed which can be defined from natural frequencies of the saw. In this article critical rotational speeds of standard clamped saws (with flat disk surface and without slots are calculated by using finite element method and classical theory of thin plates on annular plates. Mode shapes and natural frequencies of annular plates are determined by using Bessel functions and by using polynomial functions. Obtained results suggest that standard clamped circular saws without slots and with relatively small teeth can be determined from classical theory of thin plates for annular plates with accuracy depending on clamping ratio.

FINITE ELEMENT MODELING OF THIN CIRCULAR SANDWICH PLATES DEFLECTION

Directory of Open Access Journals (Sweden)

K. S. Kurachka

2014-01-01

Full Text Available A mathematical model of a thin circular sandwich plate being under the vertical load is proposed. The model employs the finite element method and takes advantage of an axisymmetric finite element that leads to the small dimension of the resulting stiffness matrix and sufficient accuracy for practical calculations. The analytical expressions for computing local stiffness matrices are found, which can significantly speed up the process of forming the global stiffness matrix and increase the accuracy of calculations. A software is under development and verification. The discrepancy between the results of the mathematical model and those of analytical formulas for homogeneous thin circularsandwich plates does not exceed 7%.

Stresses in Circular Plates with Rigid Elements

Science.gov (United States)

Velikanov, N. L.; Koryagin, S. I.; Sharkov, O. V.

2018-05-01

Calculations of residual stress fields are carried out by numerical and static methods, using the flat cross-section hypothesis. The failure of metal when exposed to residual stresses is, in most cases, brittle. The presence in the engineering structures of rigid elements often leads to the crack initiation and structure failure. This is due to the fact that rigid elements under the influence of external stresses are stress concentrators. In addition, if these elements are fixed by welding, the residual welding stresses can lead to an increase in stress concentration and, ultimately, to failure. The development of design schemes for such structures is a very urgent task for complex technical systems. To determine the stresses in a circular plate with a welded circular rigid insert under the influence of an external load, one can use the solution of the plane stress problem for annular plates in polar coordinates. The polar coordinates of the points are the polar radius and the polar angle, and the stress state is determined by normal radial stresses, tangential and shearing stresses. The use of the above mentioned design schemes, formulas, will allow more accurate determination of residual stresses in annular welded structures. This will help to establish the most likely directions of failure and take measures at the stages of designing, manufacturing and repairing engineering structures to prevent these failures. However, it must be taken into account that the external load, the presence of insulation can lead to a change in the residual stress field.

Capacity of the circular plate condenser: analytical solutions for large gaps between the plates

International Nuclear Information System (INIS)

Rao, T V

2005-01-01

A solution of Love's integral equation (Love E R 1949 Q. J. Mech. Appl. Math. 2 428), which forms the basis for the analysis of the electrostatic field due to two equal circular co-axial parallel conducting plates, is considered for the case when the ratio, τ, of distance of separation to radius of the plates is greater than 2. The kernel of the integral equation is expanded into an infinite series in odd powers of 1/τ and an approximate kernel accurate to O(τ -(2N+1) ) is deduced therefrom by terminating the series after an arbitrary but finite number of terms, N. The approximate kernel is rearranged into a degenerate form and the integral equation with this kernel is reduced to a system of N linear equations. An explicit analytical solution is obtained for N = 4 and the resulting analytical expression for the capacity of the circular plate condenser is shown to be accurate to O(τ -9 ). Analytical expressions of lower orders of accuracy with respect to 1/τ are deduced from the four-term (i.e., N 4) solution and predictions (of capacity) from the expressions of different orders of accuracy (with respect to 1/τ) are compared with very accurate numerical solutions obtained by solving the linear system for large enough N. It is shown that the O(τ -9 ) approximation predicts the capacity extremely well for any τ ≥ 2 and an O(τ -3 ) approximation gives, for all practical purposes, results of adequate accuracy for τ ≥ 4. It is further shown that an approximate solution, applicable for the case of large distances of separation between the plates, due to Sneddon (Sneddon I N 1966 Mixed Boundary Value Problems in Potential Theory (Amsterdam: North-Holland) pp 230-46) is accurate to O(τ -6 ) for τ ≥ 2

Circular arc fuel plate stability experiments and analyses for the advanced neutron source

International Nuclear Information System (INIS)

Swinson, W.F.; Battiste, R.L.; Yahr, G.T.

1995-08-01

The thin fuel plates planned for the Advanced Neutron Source are to be cooled by forcing heavy water at high velocity, 25 m/s, through thin cooling channels on each side of each plate. Because the potential for structural failure of the plates is a design concern, considerable effort has been expended in assessing this potential. As part of this effort, experimental flow tests and analyses to evaluate the structural response of circular arc plates have been conducted, and the results are given in this report

The Influence of Flexibility Coefficient on the Size of Internal Forces and Deformations in Circular Plates on Elastic Medium

Directory of Open Access Journals (Sweden)

Şandru Mirela

2016-09-01

Full Text Available This paper presents an analytical study which deals with the behavior of the circular plates in bending theory, considering the soil-structure interaction under Winkler's hypothesis. It was intended to illustrate the variation of internal forces and deformations according to the flexibility coefficient of plates considering three models: a fixed solid circular plate subjected to a uniformly distributed load, a fixed solid circular plate acted by a displacement applied on the exterior contour and a solid plate subjected to a temperature gradient. For this study the computation relations were written as a product between a dimensional and a non-dimensional factor, the last one indicating the variation of internal forces and deformations. For each type of action there are presented results obtained using the finite element method to illustrate the differences between this method and the analytical computation.

The Automated Threaded Fastening Based on On-line Identification

Directory of Open Access Journals (Sweden)

Nicolas Ivan Giannoccaro

2008-11-01

Full Text Available The principle of the thread fastenings have been known and used for decades with the purpose of joining one component to another. Threaded fastenings are popular because they permit easy disassembly for maintenance, repair, relocation and recycling. Screw insertions are typically carried out manually. It is a difficult problem to automat. As a result there is very little published research on automating threaded fastenings, and most research on automated assembly focus on the peg-in-hole assembly problem. This paper investigates the problem of automated monitoring of the screw insertion process. The monitoring problem deals with predicting integrity of a threaded insertion, based on the torque vs. insertion depth curve generated during the insertions. The authors have developed an analytical model to predict the torque signature signals during self-tapping screw insertions. However, the model requires parameters on the screw dimensions and plate material properties are difficult to measure. This paper presents a study on on-line identification during screw fastenings. An identification methodology for two unknown parameter estimation during a self-tapping screw insertion process is presented. It is shown that friction and screw properties required by the model can be reliably estimated on-line. Experimental results are presented to validate the identification procedure.

Size-dependent axisymmetric vibration of functionally graded circular plates in bifurcation/limit point instability

Science.gov (United States)

Ashoori, A. R.; Vanini, S. A. Sadough; Salari, E.

2017-04-01

In the present paper, vibration behavior of size-dependent functionally graded (FG) circular microplates subjected to thermal loading are carried out in pre/post-buckling of bifurcation/limit-load instability for the first time. Two kinds of frequently used thermal loading, i.e., uniform temperature rise and heat conduction across the thickness direction are considered. Thermo-mechanical material properties of FG plate are supposed to vary smoothly and continuously throughout the thickness based on power law model. Modified couple stress theory is exploited to describe the size dependency of microplate. The nonlinear governing equations of motion and associated boundary conditions are extracted through generalized form of Hamilton's principle and von-Karman geometric nonlinearity for the vibration analysis of circular FG plates including size effects. Ritz finite element method is then employed to construct the matrix representation of governing equations which are solved by two different strategies including Newton-Raphson scheme and cylindrical arc-length method. Moreover, in the following a parametric study is accompanied to examine the effects of the several parameters such as material length scale parameter, temperature distributions, type of buckling, thickness to radius ratio, boundary conditions and power law index on the dimensionless frequency of post-buckled/snapped size-dependent FG plates in detail. It is found that the material length scale parameter and thermal loading have a significant effect on vibration characteristics of size-dependent circular FG plates.

Vibration analysis of orthotropic circular and elliptical nano-plates embedded in elastic medium based on nonlocal Mindlin plate theory and using Galerkin method

International Nuclear Information System (INIS)

Anjomshoa, Amin; Tahani, Masoud

2016-01-01

In the present study a continuum model based on the nonlocal elasticity theory is developed for free vibration analysis of embedded ortho tropic thick circular and elliptical nano-plates rested on an elastic foundation. The elastic foundation is considered to behave like a Pasternak type of foundations. Governing equations for vibrating nano-plate are derived according to the Mindlin plate theory in which the effects of shear deformations of nano-plate are also included. The Galerkin method is then employed to obtain the size dependent natural frequencies of nano-plate. The solution procedure considers the entire nano-plate as a single super-continuum element. Effect of nonlocal parameter, lengths of nano-plate, aspect ratio, mode number, material properties, thickness and foundation on circular frequencies are investigated. It is seen that the nonlocal frequencies of the nano-plate are smaller in comparison to those from the classical theory and this is more pronounced for small lengths and higher vibration modes. It is also found that as the aspect ratio increases or the nanoplate becomes more elliptical, the small scale effect on natural frequencies increases. Further, it is observed that the elastic foundation decreases the influence of nonlocal parameter on the results. Since the effect of shear deformations plays an important role in vibration analysis and design of nano-plates, by predicting smaller values for fundamental frequencies, the study of these nano-structures using thick plate theories such as Mindlin plate theory is essential.

Research on Radial Vibration of a Circular Plate

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Wei Liu

2016-01-01

Full Text Available Radial vibration of the circular plate is presented using wave propagation approach and classical method containing Bessel solution and Hankel solution for calculating the natural frequency theoretically. In cylindrical coordinate system, in order to obtain natural frequency, propagation and reflection matrices are deduced at the boundaries of free-free, fixed-fixed, and fixed-free using wave propagation approach. Furthermore, radial phononic crystal is constructed by connecting two materials periodically for the analysis of band phenomenon. Also, Finite Element Simulation (FEM is adopted to verify the theoretical results. Finally, the radial and piezoelectric effects on the band are also discussed.

Asymmetric Vibrations of a Circular Elastic Plate on an Elastic Half Space

DEFF Research Database (Denmark)

Schmidt, H.; Krenk, Steen

1982-01-01

The asymmetric problem of a vibrating circular elastic plate in frictionless contact with an elastic half space is solved by an integral equation method, where the contact stress appears as the unknown function. By a trigonometric expansion, the problem is reduced to a number of uncoupled two...

Numerical simulation of droplet evaporation between two circular plates

International Nuclear Information System (INIS)

Bam, Hang Jin; Son, Gi Hun

2015-01-01

Numerical simulation is performed for droplet evaporation between two circular plates. The flow and thermal characteristics of the droplet evaporation are numerically investigated by solving the conservation equations of mass, momentum, energy and mass fraction in the liquid and gas phases. The liquid-gas interface is tracked by a sharp-interface level-set method which is modified to include the effects of evaporation at the liquid-gas interface and contact angle hysteresis at the liquid-gas-solid contact line. An analytical model to predict the droplet evaporation is also developed by simplifying the mass and vapor fraction equations in the gas phase. The numerical results demonstrate that the 1-D analytical prediction is not applicable to the high rate evaporation process. The effects of plate gap and receding contact angle on the droplet evaporation are also quantified.

Automation of calculation of fastening of non-standard freights on sea vessels

Directory of Open Access Journals (Sweden)

Андрій Валерійович Пархотько

2015-11-01

Full Text Available Correct positioning and fastening of freights are important safety conditions of navigation. Unreliable positioning and fastening of freights results in shipwreck and is the reason for injuries and losses of human lives both in the sea and during loading and unloading. To solve the above-mentioned problems, the International Maritime Organization publishes manuals in the form of either the Assembly resolutions, or the circulars approved by Maritime Safety Committee. The correct definition of necessary quantity of lashings and their positioning has the greatest impact on safe fastening of freights. The sea being rough, the vessel is accelerated both in longitudinal, and vertical and prevailing cross directions. The forces created by these accelerations generate the majority of the problems in fastening. The order of calculations of the force moments and forces acting upon the freights being shipped by sea vessels has been shown in the article. To know the proper number of lashings the calculations of the forces acting upon the freights being shipped as compared with the forces holding the freights and taking into account the strength, the number and the fastening angle of the lashings must be made. Оption of realization of algorithm of calculation with use of the а computer program to make these calculations has been offered. Some recommendations so that the program could be used by the management of the vessel, the surveyor companies and technologists of the port have been given as well as an example of such a calculation

Titanium fasteners. [for aircraft industry

Science.gov (United States)

Phillips, J. L.

1972-01-01

Titanium fasteners are used in large quantities throughout the aircraft industry. Most of this usage is in aluminum structure; where titanium structure exists, titanium fasteners are logically used as well. Titanium fasteners offer potential weight savings to the designer at a cost of approximately $30 per pound of weight saved. Proper and least cost usage must take into consideration type of fastener per application, galvanic couples and installation characteristics of protective coatings, cosmetic appearance, paint adhesion, installation forces and methods available and fatigue performance required.

Optimal design of sandwich ribbed flat baffle plates of a circular cylindrical tank

International Nuclear Information System (INIS)

Malinowski, Marek; Magnucki, Krzysztof

2005-01-01

The subject of this paper is a sandwich ribbed flat baffle plate of a circular cylindrical tank. The paper deals with a problem of optimal thickness of this construction with a soft core. The construction is distinguished by a local axisymmetric pre-springing. The mathematical description is based on the theory of shells with analysis of disturbance of the stress membrane state. The sandwich ribbed flat baffle plate divides the tank into two chambers. One of them is loaded by uniform pressure, while the other is empty and unloaded. Dimensions of ribs, faces and the entire baffle plate have been determined with a view to minimize the mass under strength constraints. The effect of optimal thickness of this sandwich plate has been examined by means of the finite element method

A real-time visual inspection method of fastening bolts in freight car operation

Science.gov (United States)

Nan, Guo; Yao, JunEn

2015-10-01

A real-time inspection of the key components is necessary for ensuring safe operation of freight car. While traditional inspection depends on the trained human inspectors, which is time-consuming and lower efficient. With the development of machine vision, vision-based inspection methods get more railway on-spot applications. The cross rod end fastening bolts are important components on both sides of the train body that fixing locking plates together with the freight car main structure. In our experiment, we get the images containing fastening bolt components, and accurately locate the locking plate position using a linear Support Vector Machine (SVM) locating model trained with Histograms of Oriented Gradients (HOG) features. Then we extract the straight line segment using the Line Segment Detector (LSD) and encoding them in a range, which constitute a straight line segment dataset. Lastly we determine the locking plate's working state by the linear pattern. The experiment result shows that the localization accurate rate is over 99%, the fault detection rate is over 95%, and the module implementation time is 2f/s. The overall performance can completely meet the practical railway safety assurance application.

Welding, Bonding and Fastening, 1984

Science.gov (United States)

Buckley, J. D. (Editor); Stein, B. A. (Editor)

1985-01-01

A compilation of papers presented in a joint NASA, American Society for Metals, The George Washington University, American Welding Soceity, and Society of Manufacturing Engineers conference on Welding, Bonding, and Fastening at Langley Research Center, Hampton, VA, on October 23 to 25, 1984 is given. Papers were presented on technology developed in current research programs relevant to welding, bonding, and fastening of structural materials required in fabricating structures and mechanical systems used in the aerospace, hydrospace, and automotive industries. Topics covered in the conference included equipment, hardware and materials used when welding, brazing, and soldering, mechanical fastening, explosive welding, use of unique selected joining techniques, adhesives bonding, and nondestructive evaluation. A concept of the factory of the future was presented, followed by advanced welding techniques, automated equipment for welding, welding in a cryogenic atmosphere, blind fastening, stress corrosion resistant fasteners, fastening equipment, explosive welding of different configurations and materials, solid-state bonding, electron beam welding, new adhesives, effects of cryogenics on adhesives, and new techniques and equipment for adhesive bonding.

A Study of the use of a Crystal as a `Quarter-Wave Plate' to Produce High Energy Circularly Polarized Photons

CERN Multimedia

Kononets, I

2002-01-01

%NA59 %title\\\\ \\\\We present a proposal to study the use of a crystal as a `quarter-wave plate' to produce high energy circularly polarized photons, starting from unpolarized electrons. The intention is to generate linearly polarized photons by letting electrons pass a crystalline target, where they interact coherently with the lattice nuclei. The photon polarization is subsequently turned into circular polarization after passing another crystal, which acts as a `quarter-wave plate'.

Detection of fastener loosening in simple lap joint based on ultrasonic wavefield imaging

Science.gov (United States)

Gooda Sahib, M. I.; Leong, S. J.; Chia, C. C.; Mustapha, F.

2017-12-01

Joints in aero-mechanical structures are critical elements that ensure the structural integrity but they are prone to damages. Inspection of such joints that have no prior baseline data is really challenging but it can be possibly done using the Ultrasonic Propagation Imager (UPI). The feasibility of applying UPI for detection of loosened fastener is investigated in this study. A simple lap joint specimen made by connecting two pieces of 2.5mm thick SAE304 stainless steel plates using five M6 screws and nuts has been used in this study. All fasteners are tightened to 10Nm but one of them is completely loosened to simulate the damage. The wavefield data is processed into ultrasonic wavefield propagation video and a series of spectral amplitude images. The spectral images showed noticeable amplitude difference at the loosened fastener, hence confirmed the feasibility of using UPI for structural joints inspection. A simple contrast maximization method is also introduced to improve the result.

Inactivation of Heterosigma akashiwo in ballast water by circular orifice plate-generated hydrodynamic cavitation.

Science.gov (United States)

Feng, Daolun; Zhao, Jie; Liu, Tian

2016-01-01

The discharge of alien ballast water is a well-known, major reason for marine species invasion. Here, circular orifice plate-generated hydrodynamic cavitation was used to inactivate Heterosigma akashiwo in ballast water. In comparison with single- and multihole orifice plates, the conical-hole orifice plate yielded the highest inactivation percentage, 51.12%, and consumed only 6.84% energy (based on a 50% inactivation percentage). Repeating treatment, either using double series-connection or circling inactivation, elevated the inactivation percentage, yet consumed much more energy. The results indicate that conical-hole-generated hydrodynamic cavitation shows great potential as a pre-inactivation method for ballast water treatment.

Dynamics of a Circular Mindlin Plate under Mechanical Loading and Elevated Temperature

Directory of Open Access Journals (Sweden)

Warminska Anna

2016-01-01

Full Text Available Dynamics of a nonlinear circular Midlin plate is studied in the paper. The mathematical model represented by partial differential equations includes nonlinear geometrical terms resulted from large displacements. The plate is subjected to mechanical and thermal loadings. The dynamics of a coupled thermo-mechanical problem is reduced from partial to ordinary differential equations. Considering the first mode reduction and uniformly distributed temperature just a single nonlinear differential equation is obtained. The bifurcation analysis shows that elevated temperature shifts the rezonanse curve and new solutions arise. Depending on initial conditions this may lead to buckling phenomenon and then relatively small oscillations around this state, symmetric periodic oscillations of large amplitude, or irregular oscillations.

RFID Torque Sensing Tag System for Fasteners

Science.gov (United States)

Fink, Patrick W. (Inventor); Lin, Gregory Y. (Inventor); Ngo, Phong H. (Inventor); Kennedy, Timothy F. (Inventor)

2016-01-01

The present invention provides an RFID-based torque sensor that can be used to quickly monitor off the shelf fasteners including fasteners that are used in expensive satellites or other uses where fastener failure can be very costly. In one embodiment, an antenna, RFID ring and spring comprise a sensor tag that can be interrogated with an interrogation signal produced by an interrogator device. When sufficient torque is applied to the fastener, an RFID circuit is connected, and produces a radio frequency (RF) signal that can be read by the interrogator. In one embodiment, the RFID circuit does not transmit when the spring member is not compressed, thereby indicating insufficient tensioning of the fastener. The present invention offers the ability to remotely, quickly, and inexpensively verify that any number of fasteners are torqued properly upon initial installation. Where applicable, the present invention allows low cost monitoring over the life of the fastener.

Free vibration analysis of multi directional functionally graded circular and annular plates

Energy Technology Data Exchange (ETDEWEB)

Kermani, Iman Davoodi; Ghayour, Mostafa; Mirdamadi, Hamid Reza [Isfahan Univ. of Technology, Isfahan (Iran, Islamic Republic of)

2012-11-15

This paper addresses the free vibration of multi directional functionally graded circular and annular plates using a semianalytical/numerical method, called state space based differential quadrature method. Three-dimensional elasticity equations are derived for multi directional functionally graded plates and a solution is given by the semi-analytical/numerical method. This method gives an analytical solution along the thickness direction, using a state space method and a numerical solution using differential quadrature method. Some numerical examples are presented to show the accuracy and convergence of the method. The most of simulations of the present study have been validated by the existing literature. The non dimensional frequencies and corresponding displacements mode shapes are obtained. Then the influences of thickness ratio and graded indexes are demonstrated on the non dimensional natural frequencies.

Carbon nanotube plane fastener

Directory of Open Access Journals (Sweden)

Kaori Hirahara

2011-12-01

Full Text Available We report a feature of carbon nanotubes (CNTs that arises when the surfaces of two vertically-aligned CNT brushes are pressed together. Adhesion between the CNTs creates a plane fastener-like device. Observations from scanning electron microscopy and measurements of adhesion properties indicate a device-dependence on CNT density and shape near the tip region. Among other applications, such fasteners have the potential to attach small components onto micron-sized electronic devices.

Multiple scattering and stop band characteristics of flexural waves on a thin plate with circular holes

Science.gov (United States)

Wang, Zuowei; Biwa, Shiro

2018-03-01

A numerical procedure is proposed for the multiple scattering analysis of flexural waves on a thin plate with circular holes based on the Kirchhoff plate theory. The numerical procedure utilizes the wave function expansion of the exciting as well as scattered fields, and the boundary conditions at the periphery of holes are incorporated as the relations between the expansion coefficients of exciting and scattered fields. A set of linear algebraic equations with respect to the wave expansion coefficients of the exciting field alone is established by the numerical collocation method. To demonstrate the applicability of the procedure, the stop band characteristics of flexural waves are analyzed for different arrangements and concentrations of circular holes on a steel plate. The energy transmission spectra of flexural waves are shown to capture the detailed features of the stop band formation of regular and random arrangements of holes. The increase of the concentration of holes is found to shift the dips of the energy transmission spectra toward higher frequencies as well as deepen them. The hexagonal hole arrangement can form a much broader stop band than the square hole arrangement for flexural wave transmission. It is also demonstrated that random arrangements of holes make the transmission spectrum more complicated.

Dynamics of a flexible splitter plate in the wake of a circular cylinder

Science.gov (United States)

Shukla, S.; Govardhan, R. N.; Arakeri, J. H.

2013-08-01

Rigid splitter plates in the wake of bluff bodies are known to suppress the primary vortex shedding. In the present work, we experimentally study the problem of a flexible splitter plate in the wake of a circular cylinder. In this case, the splitter plate is free to continuously deform along its length due to the fluid forces acting on it; the flexural rigidity (EI) of the plate being an important parameter. Direct visualizations of the splitter plate motions, for very low values of flexural rigidity (EI), indicate periodic traveling wave type deformations of the splitter plate with maximum tip amplitudes of the order of 1 cylinder diameter. As the Reynolds number based on cylinder diameter is varied, two regimes of periodic splitter plate motions are found that are referred to as mode I and mode II, with a regime of aperiodic motions between them. The frequency of plate motions in both periodic modes is found to be close to the plane cylinder Strouhal number of about 0.2, while the average frequencies in the non-periodic regime are substantially lower. The measured normalized phase speed of the traveling wave for both periodic modes is also close to the convection speed of vortices in the plane cylinder wake. As the flexural rigidity of the plate (EI) is increased, the response of the plate was found to shift to the right when plotted with flow speed or Re. To better capture the effect of varying EI, we define and use a non-dimensional bending stiffness, K*, similar to the ones used in the flag flutter problem, K=EI/(0.5ρUL), where U is the free-stream velocity and L is the splitter plate length. Amplitude data for different EI cases when plotted against this parameter appear to collapse on to a single curve for a given splitter plate length. Measurements of the splitter plate motions for varying splitter plate lengths indicate that plates that are substantially larger than the formation length of the plane cylinder wake have similar responses, while shorter

Modification of parabolic dish antenna pattern using two symmetrically placed circular flat plates

Science.gov (United States)

Thorpe, Glen C.

1987-12-01

This study aims to formulate a method of predicting the far field pattern of a parabolic dish antenna with two moveable flat plates mounted symmetrically on either side of the feed horn. The approach taken has been to first analyze the radiation pattern of the antenna with the disks at certain heights out from the surface of the dish. To do this the near-field radiation in amplitude and phase was measured over a plane surface in the near-field and the values were then transformed into the far field using a Fast Fourier Transform. Far field pattern values of the antenna were directly measured for each setting of the plates. The results obtained from the Fast Fourier Transform of the near field data were in good agreement with the values obtained by measurement. Finally, an approximate model of the antenna was developed and implemented as a computer program. This model, while relatively unsophisticated, provided some insights into the changes in the near field phase distribution caused by the moveable circular flat plates.

Sound Power Minimization of Circular Plates Through Damping Layer Placement

Science.gov (United States)

Wodtke, H.-W.; Lamancusa, J. S.

1998-09-01

Damping layers, widely used for noise and vibration control of thin-walled structures, can be designed to provide an optimal trade-off between performance and weight which is of particular importance in the automotive and aircraft industry. The goal of the presented work is the minimization of sound power radiated from plates under broadband excitation by redistribution of unconstrained damping layers. The total radiated sound power is assumed to be represented by the sound power radiated at the structural resonances. Resonance tracking is performed by means of single-degree-of-freedom (SDOF)-approximations based on near-resonance responses and their frequency derivatives. Axisymmetric vibrations of circular plates under several boundary and forcing conditions are considered. Frequency dependent Young's modulus and loss factor of the damping material are taken into account. Vibration analysis is based on the finite element method (FEM) while acoustic radiation is treated by means of Rayleigh's integral formula. It is shown that, starting from a uniform damping layer distribution, substantial reduction in radiated sound power can be achieved through redistribution of the damping layers. Depending on the given situation, these reductions are not only due to amplitude reductions but also to changes in vibration shapes and frequencies.

Flow Characteristics of Multi-circular Jet Plate in Premix Chamber of Air-Assist Atomizer for Burner System

Directory of Open Access Journals (Sweden)

Amirnordin Shahrin Hisham

2016-01-01

Full Text Available The flow characteristics of multi-circular jet (MCJ plate in the premix chamber of an atomizer were investigated using Computational Fluid Dynamics. Multiphase volume of fluid behavior inside the chamber was determined via steady simulations. The Eulerian–Eulerian two-fluid approach was used for execution mixing of diesel fuel and air. Spray simulation using the discrete phase with injection was generated from the nozzle hole into the ambient atmosphere. The behavior of three MCJ plates in the premix chamber was studied numerically. Results illustrated that plate open area, Ae, influenced the turbulence inside the chamber. MCJ 3, which had the lowest open area, generated the highest flow velocity and turbulence kinetic energy compared with MCJ 1 and 2. The MCJ plates could increase the turbulence in the premix chamber and contribute to the combustion efficiency.

Improvements in remote equipment torquing and fastening

International Nuclear Information System (INIS)

Garin, J.

1978-01-01

Remote torquing and fastening is a requirement of generic interest for application in an environment not readily accessible to man. The developments over the last 30 years in torque-controlled equipment above 200 nm (150 ft/lb) have not been emphasized. The development of specialized subassemblies to torque and fasten equipment in a remotely controlled environment is an integral part of the Advanced Fuel Recycle Program at Oak Ridge National Laboratory. Commercially available subassemblies have been adapted into a system that would provide remote torquing and fastening in the range of 200 to 750 nm (150 to 550 ft/lb). 9 figures

Stress-intensity factors for cracks emanating from the loaded fastener hole

Science.gov (United States)

Shivakumar, V.; Hsu, Y. C.

1977-01-01

Using a series approach and the Muskhelishvili formulation in the two-dimensional theory of elasticity, stress-intensity factors K are derived for problems in which cracks emanate radially from the boundary of an arbitrarily loaded internal circular hole in an infinite plate. Numerical values are obtained for K(I) and K(II) for radial cracks from a hole containing a loose-fitted pin or rivet that is pulled perpendicular to the crack direction in the plane of the plate. The method is a general one for determining K for a set of symmetrically emanating radial cracks for a variety of concentrated or distributed tractions on the circular hole.

Removal of T-fasteners 2 days after gastrostomy is feasible.

LENUS (Irish Health Repository)

Foster, A

2009-03-01

T-fastener gastropexy is widely performed as part of gastrostomy insertion. The current literature recommends removal of T-fasteners at 2 weeks. We present a series of patients in whom T-fasteners were removed at 2 days with no major complications. We removed T-fasteners in 109 patients (male-to-female ratio 59:50, age range 18 to 88 years, mean age 62 years) at 2 days after gastrostomy insertion. Indications for gastrostomy included amytrophic lateral sclerosis, cerebrovascular accidents, head and neck carcinoma, multiple sclerosis, and others, including brain tumours and chronic inflammatory demyelinating polyneuropathy. No peritubal leaks or other major complications were seen in the study population. In the study group, 15 minor complications were recorded (14%), including localised infection and pain, both of which resolved on removal of T-fasteners. We conclude that it is feasible and safe to remove T-fasteners at 2 days.

Moment Capacity of Timber Reinforced with Punched Metal Plate Fasteners

DEFF Research Database (Denmark)

Nielsen, Jacob; Ellegaard, Peter

When designing timber trusses it is often found that the cross section controlling the dimensions of the top chord is located at a joint with a moment peak. However, the timber volume affected by the moment peak is rather limited and by embedding a punched metal plate in this area a reinforcement...... of the section is obtained, resulting in a more economic truss design. In order to develop design methods for sections with plate reinforcement, bending tests have been made. The timber is Swedish spruce of strength class K-18(S8) and K-24(S10) with a thickness of 45 mm. The punched metal plate is from Gang...

Removal of bound metal fasteners

Science.gov (United States)

Kramer, R. F.

1981-04-01

This project explored the removal of bound metal fasteners through the use of ultrasonically assisted wrenches. Two wrenches were designed, fabricated and tested. Previous studies had indicated an increase in thread tension for a given torque application under the influence of ultrasonics. Based on this, the loosening of seized and corroded fasteners with the aid of ultrasonics was explored. Experimental data confirmed our prior analysis of the torque-tension relationship under the influence of ultrasonics; however, our progress did not satisfy the requirements necessary to loosen seized studs in a shipyard environment.

Cadmium plating replacements

Energy Technology Data Exchange (ETDEWEB)

Nelson, M.J.; Groshart, E.C.

1995-03-01

The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

Degradation of fastener in reactor internal of PWR

Energy Technology Data Exchange (ETDEWEB)

Kim, D. W.; Ryu, W. S.; Jang, J. S.; Kim, S. H.; Kim, W. G.; Chung, M. K.; Han, C. H

2000-03-01

Main component degraded in reactor internal structure of PWR is fastener such as bolts, stud, cap screw, and pins. The failure of these components may damage nuclear fuel and limits the operation of nuclear reactor. In foreign reactors operated more than 10 years, an increasing number of incidents of degraded thread fasteners have been reported. The degradation of these components impair the integrity of reactor internal structure and limit the life extension of nuclear power plant. To solve the problem of fastener failure, the incidents of failure and main mechanisms should be investigated. the purpose of this state-of-the -art report is to investigate the failure incidents and mechanisms of fastener in foreign and domestic PWR and make a guide to select a proper materials. There is no intent to describe each event in detail in this report. This report covers the failures of fastener and damage mechanisms reported by the licensees of operating nuclear power plants and the applications of plants constructed after 1964. This information is derived from pertinent licensee event report, reportable occurrence reports, operating reactor event memoranda, failure analysis reports, and other relevant documents. (author)

Development of high temperature fasteners using directionally solidified eutectic alloys

Science.gov (United States)

George, F. D.

1972-01-01

The suitability of the eutectics for high temperature fasteners was investigated. Material properties were determined as a function of temperature, and included shear parallel and perpendicular to the growth direction and torsion parallel to it. Techniques for fabricating typical fastener shapes included grinding, creep forming, and direct casting. Both lamellar Ni3Al-Ni3Nb and fibrous (Co,Cr,Al)-(Cr,Co)7C3 alloys showed promise as candidate materials for high temperature fastener applications. A brief evaluation of the performance of the best fabricated fastener design was made.

Elevated-temperature tests of simply-supported beams and circular plates subjected to time-varying loadings

International Nuclear Information System (INIS)

Corum, J.M.; Richardson, M.

1975-01-01

The measured elastic-plastic and elastic-plastic-creep responses of a number of simply-supported type 304 stainless steel beams and circular plates are presented. Beams and plates exhibit the essential features of inelastic structural behavior; yet they are relatively simple. In beams, the stress fields are largely uniaxial, while multiaxial effects are introduced in plates. The specimens were laterally loaded at the center, and the tests were performed by subjecting the specimens to either a prescribed load or center-deflection history. The specimens were machined from a common, well-characterized heat of material, and all of the tests were performed at a temperature of 1100 F. The elastic-plastic tests consisted of short-time cycling of the center load, or deflection, between fixed limits. In the elastic-plastic-creep tests the center load, or deflection, was held constant for periods of time, but was periodically subjected to a step increase or decrease, including reversals. The test results are presented in terms of the load and center-deflection behaviors, which typify the overall structural behavior. (U.S.)

Spray and Combustion Characteristics of a Novel Multi-circular Jet Plate in Air-assisted Atomizer

Directory of Open Access Journals (Sweden)

Hisham Amirnordin Shahrin

2017-01-01

Full Text Available Atomization of liquid fuel in air-assisted atomizer is highly dependent on air mixing, which can be enhanced using turbulent generators, such as multi-circular jet (MCJ plates and swirler. This study aims to determine the effects of novel MCJ plates on the spray and combustion characteristics of an air-assisted atomizer by evaluating spray and flame parameters, such as penetration length, cone angle, and cone area. MCJ 30 and MCJ 45, with inclined jets at 30° and 45°, respectively, were used in the experiment. A swirler was also used for comparison. The spray and flame images were recorded at different equivalence ratios through direct photography and analyzed using image J software. Flame temperature was determined using a thermal infrared camera, and burning chamber and flue gas temperatures were measured using thermocouples. The spray and flame characteristics of MCJ 30 exhibited performance comparable with those of the MCJ 45 and swirler. The integration of turbulence and swirling motion concept into the novel MCJ plates can enhance the mixing formation and thus improve the performance of burner combustion.

Asymmetric Vibration of Polar Orthotropic Annular Circular Plates of Quadratically Varying Thickness with Same Boundary Conditions

Directory of Open Access Journals (Sweden)

N. Bhardwaj

2008-01-01

Full Text Available In the present paper, asymmetric vibration of polar orthotropic annular circular plates of quadratically varying thickness resting on Winkler elastic foundation is studied by using boundary characteristic orthonormal polynomials in Rayleigh-Ritz method. Convergence of the results is tested and comparison is made with results already available in the existing literature. Numerical results for the first ten frequencies for various values of parameters describing width of annular plate, thickness profile, material orthotropy and foundation constant for all three possible combinations of clamped, simply supported and free edge conditions are shown and discussed. It is found that (a higher elastic property in circumferential direction leads to higher stiffness against lateral vibration; (b Lateral vibration characteristics of F-Fplates is more sensitive towards parametric changes in material orthotropy and foundation stiffness than C-C and S-Splates; (c Effect of quadratical thickness variation on fundamental frequency is more significant in cases of C-C and S-S plates than that of F-Fplates. Thickness profile which is convex relative to plate center-line tends to result in higher stiffness of annular plates against lateral vibration than the one which is concave and (d Fundamental mode of vibration of C-C and S-Splates is axisymmetrical while that of F-Fplates is asymmetrical.

Alternate model of Chladni figures for the circular homogenous thin plate case with open boundaries

International Nuclear Information System (INIS)

Trejo-Mandujano, H A; Mijares-Bernal, G; Ordoñez-Casanova, E G

2015-01-01

The wave equation is a direct but a complex approach to solve analytically for the Chladni figures, mainly because of the complications that non-smooth and open boundary conditions impose. In this paper, we present an alternate solution model based on the principle of Huygens-Fresnel and on the ideas of Bohr for the hydrogen atom. The proposed model has been implemented numerically and compared, with good agreement, to our own experimental results for the case of a thin homogenous circular plate with open boundaries

Cylinder head fastening structure for internal combustion engines

Energy Technology Data Exchange (ETDEWEB)

Futakuchi, Y.; Oshiro, N.

1988-01-26

In a construction for an overhead cam internal combustion engine comprising a cylinder head adapted to be affixed to another component of the engine by at least one fastener having a tool receiving portion for tightening thereof and having a bearing cap affixed to the cylinder head and rotatably journaling the overhead camshaft, the improvement is described comprising the bearing cap having a portion overlying the fastener tool receiving portion, and means defining an access opening passing through the bearing cap and adapted to pass a tool for tightening of the fastener without removal of the bearing cap.

Hydraulic screw fastening devices - design, maintenance, operational experience

International Nuclear Information System (INIS)

Lachner.

1976-01-01

With hydraulic screw fastening devices, pretension values with a maximum deviation of +-2.5% from the rated value can be achieved. This high degree of pretension accuracy is of considerable importance with regard to the safety factor required for the screw connection between reactor vessel head and reactor vessel. The operating rhythm of a nuclear power station with its refuelling art regular intervals makes further demands on the screw fastening device, in particular in connection with the transport of screws and for nuts. The necessary installations extend the screw fastening device into a combination of a high-pressure hydraulic cylinder system with an electrical or pneumoelectrical driving unit and an electrical control unit. Maintenance work is complicated by the large number of identical, highly stressed structural elements in connection with an unfavourable relation operating time/outage time. The problems have been perpetually reduced by close cooperation between the manufacturers and users of screw fastening devices. (orig./AK) [de

Elevated-temperature benchmark tests of simply supported beams and circular plates subjected to time-varying loadings

International Nuclear Information System (INIS)

Corum, J.M.; Richardson, M.; Clinard, J.A.

1977-01-01

This report presents the measured elastic-plastic-creep responses of eight simply supported type 304 stainless steel beams and circular plates that were subjected to time-varying loadings at elevated temperature. The tests were performed to provide experimental benchmark problem data suitable for assessing inelastic analysis methods and for validating computer programs. Beams and plates exhibit the essential features of inelastic structural behavior; yet they are relatively simple and the experimental results are generally easy to interpret. The stress fields are largely uniaxial in beams, while multiaxial effects are introduced in plates. The specimens tested were laterally loaded at the center and subjected to either a prescribed load or a center deflection history. The specimens were machined from a common well-characterized heat of material, and all the tests were performed at a temperature of 593 0 C (1100 0 F). Test results are presented in terms of the load and center deflection behaviors, which typify the overall structural behavior. Additional deflection data, as well as strain gage results and mechanical properties data for the beam and plate material, are provided in the appendices

Combined Effect of Surface Roughness and Wake Splitter Plate on the Aerodynamic Characteristics of a Circular Cylinder

Science.gov (United States)

Saisanthosh, Iyer; Arunkumar, K.; Ajithkumar, R.; Srikrishnan, A. R.

2017-09-01

This paper is focussed on numerical investigation of flow around a stationary circular cylinder (diameter, D) with selectively applied surface roughness (roughness strips with thickness ‘k’) in the presence of a wake splitter plate (length, L). The plate leading edge is at a distance of ‘G’ from the cylinder base. For this study, the commercial software ANSYS Fluent is used. Fluid considered is water. Study was conducted the following cases (a) plain cylinder (b) cylinder with surface roughness (without splitter plate) (c) Cylinder with splitter plate (without surface roughness) and (d) cylinder with both roughness and splitter plate employed. The study Reynolds number (based on D) is 17,000 and k/δ = 1.25 (in all cases). Results indicate that, for cylinder with splitter plate (no roughness), lift coefficient gradually drops till G/D=1.5 further to which it sharply increases. Whereas, drag coefficient and Strouhal number undergoes slight reduction till G/D=1.0 and thereafter, gradually increase. Circumferential location of strip (α) does not influence the aerodynamic parameters significantly. With roughness alone, drag is magnified by about 1.5 times and lift, by about 2.7 times that of the respective values of the smooth cylinder. With splitter plate, for roughness applied at all ‘α’ values, drag and lift undergoes substantial reduction with the lowest value attained at G/D=1.0.

Effects of Velocity-Slip and Viscosity Variation in Squeeze Film Lubrication of Two Circular Plates

Directory of Open Access Journals (Sweden)

R.R. Rao

2013-03-01

Full Text Available A generalized form of Reynolds equation for two symmetrical surfaces is taken by considering velocity-slip at the bearing surfaces. This equation is applied to study the effects of velocity-slip and viscosity variation for the lubrication of squeeze films between two circular plates. Expressions for the load capacity and squeezing time obtained are also studied theoretically for various parameters. The load capacity and squeezing time decreases due to slip. They increase due to the presence of high viscous layer near the surface and decrease due to low viscous layer.

On three phase lags thermodi¤usion theory in micropolar porous circular plate

Directory of Open Access Journals (Sweden)

Rajneesh Kumar

2017-09-01

Full Text Available The present work examines a two dimensional axisymmetric problem of micropolar porous thermodi¤usion circular plate due to thermal and chemical potential sources. The governing equations are solved by using the potential function. The expressions of displacements, microrotation, volume fraction field, temperature distribution, concentration and stresses are obtained in the transformed domain by using Laplace and Hankel transforms. The inversion of transforms using Fourier expansion techniques has been applied to obtain the results in the physical domain. The numerical results for resulting quantities are obtained and depicted graphically to show the influence of porosity, relaxation time, phase lags, with and without energy dissipation on the resulting quantities. Some particular cases are also deduced.

Threaded-fastener experience in nuclear power plants

International Nuclear Information System (INIS)

Koo, W.H.

1983-01-01

This report identifies 44 incidents of threaded-fastener degradation and failure in nuclear power plants from October 1964 to March 1982. It provides an overview of some of the threaded-fastener problems that have occurred since 1964. Safety implications of these incidents are discussed, and short-term regulatory actions and ongoing long-term regulatory actions are described. Information included in this report represents the current NRC staff understanding of each issue

Development of an anti-loosening fastener and comparing its ...

Indian Academy of Sciences (India)

Bikash Panja

2017-09-08

Sep 8, 2017 ... MS received 13 November 2013; revised 20 June 2016; accepted 30 April ... However, threaded fasteners may have the problem of loosening under vibrating ..... [7] Junker G H 1969 New criteria for self-loosening of fasteners.

Fastener tightening in a radioactive (hot) cell

International Nuclear Information System (INIS)

Kalk, J.J.

1986-01-01

Accurate remote tightening of fasteners in a radioactive (Hot) cell can be a very exasperating experience. Viewing can be difficult (in many places) and work sometimes must be done using mirrors and/or cameras. If electro mechanical manipulators are used, the operator has no ''feel,'' which often can result in cross threading, or improper torquing of fasteners. At the Interim Examination and Maintenance (IEM) Cell, where reactor components from the Fast Flux Test Facility (FFTF) are disassembled, these problems are prevalent because three of the IEM Cell walls have no windows. Electric impact wrenches were first proposed and tested for the IEM Cell, but the combined effects of radiation, dry argon atmosphere and poor visibility radically altered the cell tool development philosophy. This change in philosophy is reflected in the development of several simple fastener tightening devices

Fastener tightening in a radioactive (hot) cell

International Nuclear Information System (INIS)

Kalk, J.J.

1987-01-01

Accurate remote tightening of fasteners in a radioactive (hot) cell can be a very exasperating experience. Viewing can be difficult (in many places) and work sometimes must be done using mirrors and/or cameras. If electro mechanical manipulators are used, the operator has no feel, which often can result in cross threading, or improper torquing of fasteners. At the Interim Examination and Maintenance (IEM) Cell, where reactor components from the Fast Flux Testing Facility (FFTF) are disassembled, these problems are prevalent because three of the IEM Cell walls have no windows. Electric impact wrenches were first proposed and tested for the IEM Cell, but the combined effects of radiation, dry argon atmosphere and poor visibility radically altered the cell tool development philosophy. This change in philosophy is reflected in the development of several simple fastener tightening devices

A study of the vortex structures around circular cylinder mounted on vertical heated plate

Science.gov (United States)

Malah, Hamid; Chumakov, Yurii S.; Levchenya, Alexander M.

2018-05-01

In recent years, studies of natural convection boundary layer interacting with obstacles draw much of attention, because of its practical applications. Pressure gradient resulting from this interaction leads to separation of the boundary layer. The formation of vortex structure around obstacle is characteristic to any kind of convection flow. In this paper, we describe the formation of three-dimensional vortex structure for the case of natural convection flow around the circular cylinder mounted on vertical heated plate. Navier-Stokes equations were used for numerical computations. The results proved the presence of a horseshoe vortex system in the case of natural convection flow as in the forced convection flow.

Inflation of polymer melts into elliptic and circular cylinders

DEFF Research Database (Denmark)

Rasmussen, Henrik Koblitz; Christensen, Jens Horslund; Gøttsche, Søren

2000-01-01

A thin sheet (membrane) of the polymeric material is clamped between a Teflon-coated thermostated plate and a thermostated aluminium cylinder. By applying thermostated air through the plate, the polymer membrane deforms into an elliptic or a circular cylinder. The position of the top of the infla......A thin sheet (membrane) of the polymeric material is clamped between a Teflon-coated thermostated plate and a thermostated aluminium cylinder. By applying thermostated air through the plate, the polymer membrane deforms into an elliptic or a circular cylinder. The position of the top...

Theory of timber connections with slender dowel type fasteners

DEFF Research Database (Denmark)

Svensson, Staffan; Munch-Andersen, Jørgen

2018-01-01

A theory on the lateral load-carrying capacity of timber connections with slender fasteners is presented. The base of the theory is the coupled mechanical phenomena acting in the connection, while the wood and the slender fastener deform and yield prior to failure. The objective is to derive...... a sufficient description of actions and responses which have determining influence on the load-carrying capacity of timber connections with slender fasteners. Model assumptions are discussed and made, but simplifications are left out. Even so, simple mathematical equations describing the lateral capacity......-carrying capacity of the tested connections....

Elastic stability of thick auxetic plates

International Nuclear Information System (INIS)

Lim, Teik-Cheng

2014-01-01

Auxetic materials and structures exhibit a negative Poisson’s ratio while thick plates encounter shear deformation, which is not accounted for in classical plate theory. This paper investigates the effect of a negative Poisson’s ratio on thick plates that are subjected to buckling loads, taking into consideration the shear deformation using Mindlin plate theory. Using a highly accurate shear correction factor that allows for the effect of Poisson’s ratio, the elastic stability of circular and square plates are evaluated in terms of dimensionless parameters, namely the Mindlin-to-Kirchhoff critical buckling load ratio and Mindlin critical buckling load factors. Results for thick square plates reveal that both parameters increase as the Poisson’s ratio becomes more negative. In the case of thick circular plates, the Mindlin-to-Kirchhoff critical buckling load ratios and the Mindlin critical buckling load factors increase and decrease, respectively, as the Poisson’s ratio becomes more negative. The results obtained herein show that thick auxetic plates behave as thin conventional plates, and therefore suggest that the classical plate theory can be used to evaluate the elastic stability of thick plates if the Poisson’s ratio of the plate material is sufficiently negative. The results also suggest that materials with highly negative Poisson’s ratios are recommended for square plates, but not circular plates, that are subjected to buckling loads. (paper)

Double fastener-type contamination protective cloth

International Nuclear Information System (INIS)

Nomura, Norio.

1996-01-01

In the cloth of the present invention, a hood portion covering the entire of a head and a suit portion having an upper half body portion and a lower half body portion connected to the upper half portion for covering from a neck to ankles are made integrated. The suit portion has long sleeves at the upper half body portion, and has strait leg portions at the lower half body portion. Two linear sliding fasteners are disposed from the neck portion on the front surface of the suit portion to the lower edges of both ankle portions. The sliding fasteners have a double structure having a folded portion at the inner side. Slits are formed on the outer side surfaces of each of the ankle portions and openable/closable face fasteners are attached. A rubber is incorporated in the wrist portions at the top ends of the long sleeves to be in close contact with the wrists. An operator can easily put on and off the cloth without withdrawing legs. Accordingly, radioactive contamination can be prevented upon putting on and off the cloth. (I.N.)

Corrosion rates of fasteners in treated wood exposed to 100% relative humidity

Science.gov (United States)

Samuel L. Zelinka; Douglas R. Rammer

2009-01-01

In the past, gravimetric corrosion data for fasteners exposed to treated wood has been reported as a percent weight loss. Although percent weight loss is a valid measure of corrosion for comparing identical fasteners, it can distort the corrosion performance of fasteners with different geometries and densities. This report reevaluates a key report on the corrosiveness...

A novel method for detecting second harmonic ultrasonic components generated from fastened bolts

Science.gov (United States)

Fukuda, Makoto; Imano, Kazuhiko

2012-09-01

This study examines the use of ultrasonic second harmonic components in the quality control of bolt-fastened structures. An improved method for detecting the second harmonic components, from a bolt fastened with a nut, using the transmission method is constructed. A hexagon head iron bolt (12-mm diameter and 25-mm long) was used in the experiments. The bolt was fastened using a digital torque wrench. The second harmonic component increased by approximately 20 dB before and after the bolt was fastened. The sources of second harmonic components were contact acoustic nonlinearity in the screw thread interfaces of the bolt-nut and were the plastic deformation in the bolt with fastening bolt. This result was improved by approximately 10 dB compared with previous our method. Consequently, usefulness of the novel method for detecting second harmonic ultrasonic components generated from fastened bolt was confirmed.

Investigation of Fastening Performance of Subminiature Serrated Bolt

Energy Technology Data Exchange (ETDEWEB)

Jang, Myung Guen; Jeong, Jin Hwan; Jang, Yeon Hui; Kim, Hee Cheol; Kim, Jong-Bong [Seoul Nat’l Univ. of Science & Tech, Seoul (Korea, Republic of)

2017-04-15

As the size of electric products such as mobile phones and smart watches decrease, the bolts used to assemble these products should also be miniaturized. A miniature-sized bolt has to provide sufficient joining torque and anti-releasing torque to keep the components together. We studied a serrated bolt as a candidate for a miniature-sized fastener to increase the anti-releasing torque. In a serrated bolt, a serrated shape is formed on the bottom surface of the bolt head to create an obstacle to releasing. In this study, finite element analyses for the joining and releasing of bolts were carried out, and the anti-releasing performance was predicted. Based on the results of analyses using various numbers of serrations and fastening depths, the effects of the number of serrations and fastening depth on the anti-releasing performance were investigated.

Investigation of Fastening Performance of Subminiature Serrated Bolt

International Nuclear Information System (INIS)

Jang, Myung Guen; Jeong, Jin Hwan; Jang, Yeon Hui; Kim, Hee Cheol; Kim, Jong-Bong

2017-01-01

As the size of electric products such as mobile phones and smart watches decrease, the bolts used to assemble these products should also be miniaturized. A miniature-sized bolt has to provide sufficient joining torque and anti-releasing torque to keep the components together. We studied a serrated bolt as a candidate for a miniature-sized fastener to increase the anti-releasing torque. In a serrated bolt, a serrated shape is formed on the bottom surface of the bolt head to create an obstacle to releasing. In this study, finite element analyses for the joining and releasing of bolts were carried out, and the anti-releasing performance was predicted. Based on the results of analyses using various numbers of serrations and fastening depths, the effects of the number of serrations and fastening depth on the anti-releasing performance were investigated.

Vortex Shedding Characteristics of the Wake of a Thin Flat Plate with a Circular Trailing Edge

Science.gov (United States)

Rai, Man Mohan

2018-01-01

The near and very near wake of a thin flat plate with a circular trailing edge are investigated with direct numerical simulations (DNS). Data obtained for two different Reynolds numbers (based on plate thickness, D) are the main focus of this study. The separating boundary layers are turbulent in both cases. An earlier investigation of one of the cases (Case F) showed shed vortices in the wake that were about 1.0 D to 4.0 D in spanwise length. Considerable variation in both the strength and frequency of these shed vortices was observed. One objective of the present investigation is to determine the important contributors to this variability in strength and frequency of shed vortices and their finite spanwise extent. Analysis of the data shows that streamwise vortices in the separating boundary layer play an important role in strengthening/weakening of the shed vortices and that high/low-speed streaks in the boundary layer are important contributors to variability in shedding frequency. Both these features of the boundary layer contribute to the finite extent of the vortices in the spanwise direction. The second plate DNS (Case G, with 40 percent of the plate thickness of Case F) shows that while shedding intensity is weaker than obtained in Case F, many of the wake features are similar to that of Case F. This is important in understanding the path to the wake of the thin plate with a sharp trailing edge where shedding is absent. Here we also test the efficacy of a functional relationship between the shedding frequency and the Reynolds numbers based on the boundary layer momentum thickness (Re (sub theta) and D (Re (sub D)); data for developing this behavioral model is from Cases F & G and five earlier DNSs of the flat plate wake.

Asymmetric free vibrations of laminated annular cross-ply circular plates including the effects of shear deformation and rotary inertia. Spline method

Energy Technology Data Exchange (ETDEWEB)

Viswanathan, K.K.; Kim, Kyung Su; Lee, Jang Hyun [Inha Univ., Incheon (Korea). Dept. of Naval Architecture and Ocean Engineering

2009-12-15

Asymmetric free vibrations of annular cross-ply circular plates are studied using spline function approximation. The governing equations are formulated including the effects of shear deformation and rotary inertia. Assumptions are made to study the cross-ply layered plates. A system of coupled differential equations are obtained in terms of displacement functions and rotational functions. These functions are approximated using Bickley- type spline functions of suitable order. Then the system is converted into the eigenvalue problem by applying the point collocation technique and suitable boundary conditions. Parametric studies have been made to investigate the effect of transverse shear deformation and rotary inertia on frequency parameter with respect to the circumferential node number, radii ratio and thickness to radius ratio for both symmetric and anti-symmetric cross-ply plates using various types of material properties. (orig.)

Factors influencing power hand tool fastening accuracy and reaction forces.

Science.gov (United States)

Radwin, Robert G; Chourasia, Amrish O; Howery, Robert S; Fronczak, Frank J; Yen, Thomas Y; Subedi, Yashpal; Sesto, Mary E

2014-06-01

A laboratory study investigated the relationship between power hand tool and task-related factors affecting threaded fastener torque accuracy and associated handle reaction force. We previously developed a biodynamic model to predict handle reaction forces. We hypothesized that torque accuracy was related to the same factors that affect operator capacity to react against impulsive tool forces, as predicted by the model. The independent variables included tool (pistol grip on a vertical surface, right angle on a horizontal surface), fastener torque rate (hard, soft), horizontal distance (30 cm and 60 cm), and vertical distance (80 cm, 110 cm, and 140 cm). Ten participants (five male and five female) fastened 12 similar bolts for each experimental condition. Average torque error (audited - target torque) was affected by fastener torque rate and operator position. Torque error decreased 33% for soft torque rates, whereas handle forces greatly increased (170%). Torque error also decreased for the far horizontal distance 7% to 14%, when vertical distance was in the middle or high, but handle force decreased slightly 3% to 5%. The evidence suggests that although both tool and task factors affect fastening accuracy, they each influence handle reaction forces differently. We conclude that these differences are attributed to different parameters each factor influences affecting the dynamics of threaded faster tool operation. Fastener torque rate affects the tool dynamics, whereas posture affects the spring-mass-damping biodynamic properties of the human operator. The prediction of handle reaction force using an operator biodynamic model may be useful for codifying complex and unobvious relationships between tool and task factors for minimizing torque error while controlling handle force.

Effect of plate shapes in orifice plate type flowmeters

International Nuclear Information System (INIS)

Moeller, S.V.

1984-01-01

The study of unusual plate shapes in orifice plate type flowmeters is presented, with a view to providing data for the substitution of the plate with one centered circular orifice in those applications where its use is not possible. For this purpose, six pairs of plates with different forms, with and without chamfered edges, were made and tested in a closed water loop. Results show that, generally, the use of chamfers improves the results and, in the case of perforated and slotlike orificed plates, the narrow-ness of the fluid passage tends to make unnecessary its use. (Author) [pt

Velcro-like fasteners based on NiTi micro-hook arrays

International Nuclear Information System (INIS)

Vokoun, D; Pilch, J; Majtás, D; Šittner, P; Sedlák, P; Frost, M

2011-01-01

A recently developed Velcro-like fastener utilizes superelastic deformation of two interlocked NiTi hooks when pulled apart. This work focuses on experimental analysis (evaluation of normal detachment force at different temperatures) and modeling (simulation by a finite element implemented SMA model) of the unhooking process. It is claimed that nonlinear superelastic deformation of NiTi leads to unique properties of the NiTi hook fasteners such as high strength (∼15 000 kg m −2 ), a significant increase of strength with increasing temperature, absorption of impact loads, damping of mechanical vibrations, forceless contact or silent release and better functioning in dirty environments compared to conventional Velcro fasteners

Heat/mass transfer on effusion plate with circular pin fins for impingement/effusion cooling system with initial crossflow

International Nuclear Information System (INIS)

Hong, Sung Kook; Rhee, Dong Ho; Cho, Hyung Hee

2005-01-01

Impingement/effusion cooling technique is used for combustor liner or turbine parts cooling in gas turbine engine. In the impingement/effusion cooling system, the crossflow generated in the cooling channel induces an adverse effect on the cooling performance, which consequently affects the durability of the cooling system. In the present study, to reduce the adverse effect of the crossflow and improve the cooling performance, circular pin fins are installed in impingement/effusion cooling system and the heat transfer characteristics are investigated. The pin fins are installed between two perforated plates and the crossflow passes between these two plates. A blowing ratio is changed from 0.5 to 1.5 for the fixed jet Reynolds number of 10,000 and five circular pin fin arrangements are considered in this study. The local heat/mass transfer coefficients on the effusion plate are measured using a naphthalene sublimation method. The results show that local distributions of heat/mass transfer coefficient are changed due to the installation of pin fins. Due to the generation of vortex and wake by the pin fin, locally low heat/mass transfer regions are reduced. Moreover, the pin fin prevents the wall jet from being swept away, resulting in the increase of heat/mass transfer. When the pin fin is installed in front of the impinging jet, the blockage effect on the crossflow enhances the heat/mass transfer. However, the pin fin installed just behind the impinging jet blocks up the wall jet, decreasing the heat/mass transfer. As the blowing ratio increases, the pin fins lead to the higher Sh value compared to the case without pin fins, inducing 16%∼22% enhancement of overall Sh value at high blowing ratio of M=1.5

Fastening, coupling and joining technique between diaspora and irredenta

Science.gov (United States)

Bauer, C.-O.

1980-06-01

The problem of eliminating the present divergence and shattering (diaspora) in the treatment of problems of the fastening, coupling, and joining technique on different technical branches is examined. It is shown that by an appropriate independence the fastening, coupling and joining techniques can recognize and consequently utilize the numerous performance reserves which are concealed by the present organization and action due to the lack of systematically tended works.

Compilation of fastener testing data received in response to NRC Compliance Bulletin 87-02

International Nuclear Information System (INIS)

Cwalina, G.C.; Conway, J.T.; Parker, L.B.

1989-06-01

On November 6, 1987, the Nuclear Regulatory Commission (NRC) issued Bulletin 87-02, ''Fastener Testing to Determine Conformance With Applicable Material Specifications,'' to all holders of operating licenses or construction permits for nuclear power reactors (licensees). The bulletin was issued so that the NRC staff could gather data to determine whether counterfeit fasteners are a problem in the nuclear power industry. The bulletin requested nuclear power plant owners to determine whether fasteners obtained from suppliers and/or manufacturers for use in their facilities meet the mechanical and chemical specifications stipulated in the procurement documents. The licensees were requested to sample a minimum of 10 safety-related and 10 non-safety-related fasteners (studs, bolts, and/or cap screws) and a sample of typical nuts that would be used with each fastener and to report the testing results to the NRC. The results of this study did not indicate a safety concern relating to the use of mismarked or counterfeit fasteners in the nuclear industry, but they did indicate a nonconformance rate of 8 to 12 percent for fasteners. The NRC staff is considering taking action to improve the effectiveness of receipt inspection and testing programs for all materials at nuclear power plants

Localization of CO2 Leakage from a Circular Hole on a Flat-Surface Structure Using a Circular Acoustic Emission Sensor Array

Directory of Open Access Journals (Sweden)

Xiwang Cui

2016-11-01

Full Text Available Leak localization is essential for the safety and maintenance of storage vessels. This study proposes a novel circular acoustic emission sensor array to realize the continuous CO2 leak localization from a circular hole on the surface of a large storage vessel in a carbon capture and storage system. Advantages of the proposed array are analyzed and compared with the common sparse arrays. Experiments were carried out on a laboratory-scale stainless steel plate and leak signals were obtained from a circular hole in the center of this flat-surface structure. In order to reduce the influence of the ambient noise and dispersion of the acoustic wave on the localization accuracy, ensemble empirical mode decomposition is deployed to extract the useful leak signal. The time differences between the signals from the adjacent sensors in the array are calculated through correlation signal processing before estimating the corresponding distance differences between the sensors. A hyperbolic positioning algorithm is used to identify the location of the circular leak hole. Results show that the circular sensor array has very good directivity toward the circular leak hole. Furthermore, an optimized method is proposed by changing the position of the circular sensor array on the flat-surface structure or adding another circular sensor array to identify the direction of the circular leak hole. Experiential results obtained on a 100 cm × 100 cm stainless steel plate demonstrate that the full-scale error in the leak localization is within 0.6%.

Prevailing Torque Locking Feature in Threaded Fasteners Using Anaerobic Adhesive

Science.gov (United States)

Hernandez, Alan; Hess, Daniel P.

2016-01-01

This paper presents results from tests to assess the use of anaerobic adhesive for providing a prevailing torque locking feature in threaded fasteners. Test procedures are developed and tests are performed on three fastener materials, four anaerobic adhesives, and both unseated assembly conditions. Five to ten samples are tested for each combination. Tests for initial use, reuse without additional adhesive, and reuse with additional adhesive are performed for all samples. A 48-hour cure time was used for all initial use and reuse tests. Test data are presented as removal torque versus removal angle with the specification required prevailing torque range added for performance assessment. Percent specification pass rates for the all combinations of fastener material, adhesive, and assembly condition are tabulated and reveal use of anaerobic adhesive as a prevailing torque locking feature is viable. Although not every possible fastener material and anaerobic adhesive combination provides prevailing torque values within specification, any combination can be assessed using the test procedures presented. Reuse without additional anaerobic adhesive generally provides some prevailing torque, and in some cases within specification. Reuse with additional adhesive often provides comparable removal torque data as in initial use.

Component assembly with shape memory polymer fastener for microrobots

Science.gov (United States)

Kim, Ji-Suk; Lee, Dae-Young; Koh, Je-Sung; Jung, Gwang-Pil; Cho, Kyu-Jin

2014-01-01

Adhesives are generally used for the assembly of microrobots, whereas bolts, screws, or rivets are used for larger robots. Although adhesives are easy to apply, lightweight, and small, they cannot be used for repeated assembly and disassembly of parts. In this paper, we present a novel microfastener composed of a polyurethane-based shape memory polymer (SMP) that is lightweight and small but that is easily detached for disassembly. This was achieved by using the shape recovery and modulus change of the SMP. A sheet of macromolded SMP was laser machined into an I-beam-shaped rivet, and notches were added to the structure to prevent stress concentration. Pull-off tests showed that, as the notch radius increased, the disengagement strength of the rivet fastener decreased and the reusability increased. Through the elastoplastic model, a single SMP rivet was calculated to have maximum disengagement strength of 150 N cm-2 in the elastic range, depending on the notch radius. The fasteners were applied to a jumping microrobot. The legs and body were assembled with ten fasteners, which showed no permanent deformation after impact during jumping movements. The legs were easily replaced with ones of different stiffness by heating the engaged sites to make the fasteners compliant and detachable. The proposed detachable SMP microfasteners are particularly useful for testing the isolated performance of microrobot components to determine the optimal designs for these components.

Bottom nozzle for nuclear reactor fuel assembly having an adaptor plate and a coupled filtration plate

International Nuclear Information System (INIS)

Verdier, M.; Mortgat, R.

1992-01-01

The bottom nozzle includes an adaptor plate with openings to allow the passage of water and a filtration plate with small holes. The openings in the adaptor plate are symmetrical with regard to medians and diagonals. Within each zone, some of the openings are rectangular and some may be circular. The small holes in the filtration plate coincide with the rectangular openings in the adaptor plate

Effects of surface roughness, MHD and couple stress on squeeze film characteristics between curved circular plates

Science.gov (United States)

Hanumagowda, B. N.; Salma, A.; Nagarajappa, C. S.

2018-04-01

The theoretical discussion is carried out for understanding the combined study of MHD, rough surface and couple-stress in the presence of applied magnetic field between two curved circular plates is present analysis. Modified Reynolds Equations accounting for rough surface using stochastic model of Christensen are mathematically formulated. The close form derivations for pressure, load-supporting capacity and response-film time are obtained. Our results shows that, there is an significant increase (decrease) for pressure, load-supporting capacity and squeeze film time due to the effect of azimuthal (radial) roughness parameter when compared to the Hanumagowda.et.al [14] and numerical data of load supporting capacity and response time are given in Table for engineering applications.

Wear plates control rod guide tubes top internal reactor vessel C. N. VANDELLOS II

International Nuclear Information System (INIS)

2010-01-01

The guide tubes for control rods forming part of the upper internals of the reactor vessel, its function is to guide the control rod to permit its insertion in the reactor core. These guide tubes are suspended from the upper support plate which are fixed by bolts and extending to the upper core plate which is fastened by clamping bolts (split pin) to prevent lateral displacement of the guide tubes, while allowing axial expansion.

Fastener investigation in JET

Energy Technology Data Exchange (ETDEWEB)

Bunting, P., E-mail: patrick.bunting@ccfe.ac.uk; Thompson, V.; Riccardo, V.

2016-11-15

Highlights: • Experimental work to identify the cause of a bolt seizure inside the JET vessel. • Taguchi method used to reduce tests to 16 while covering 5 parameters. • Experimental work was unable to reproduce bolt seizure. • Thread contamination had little effect on the bolt performance. - Abstract: JET is an experimental fusion reactor consisting of magnetically confined, high temperature plasma inside a large ultra-high vacuum chamber. The inside of the chamber is protected from the hot plasma with tiles made from beryllium, tungsten, carbon composites and other materials bolted to the vessel wall. The study was carried out in response to a JET fastener seizing inside the vacuum vessel. The following study looks at characterising the magnitude of the individual factors affecting the fastener break away torque. This was carried out using a statistical approach, the Taguchi method: isolating the net effect of individual factors present in a series of tests [1](Grove and Davis, 1992). Given the severe environment within the JET vessel due to the combination of heat, ultra-high vacuum and the high contact pressure in bolt threads, the contributions of localised diffusion bonding is assessed in conjunction with various combinations of bolt and insert material.

Fastener Corrosion: A Result of Moisture Problems in the Building Envelope

Science.gov (United States)

Samuel L. Zelinka

2013-01-01

This paper reviews recent literature on the corrosion of metals embedded in wood and highlights the link be-tween moisture accumulation in wood and fastener cor-rosion. Mechanisms of fastener corrosion are described including dependence upon wood moisture content. These fundamental concepts are applied to practical examples by explaining how hygrothermal models can be...

Numerical Analysis of Thermal Stresses around Fasteners in Composite Metal Foils

Science.gov (United States)

Nammi, S. K.; Butt, J.; –L Mauricette, J.; Shirvani, H.

2017-12-01

The process of composite metal foil manufacturing (CMFM) has reduced a number of limitations associated with commercial additive manufacturing (AM) methods. The existing metal AM machines are restricted by their build envelope and there is a growing market for the manufacture of large parts using AM. These parts are subsequently manufactured in fragments and are fastened together. This paper analyses the thermal stresses around cylindrical fasteners for three layered metal composite parts consisting of aluminium foil, brazing paste and copper foil layers. The investigation aims to examine the mechanical integrity of the metallurgically bonded aluminium/copper foils of 100 micron thickness manufactured in a disc shape. A cylindrical fastener set at an elevated temperature of 100 °C is fitted in the middle of the disc which results in a steady-state thermal distribution. Radial and shear stresses are computed using finite element method which shows that non-zero shear stresses developed by the copper layer inhibit the axial slippage of the fastener and thereby establishing the suitability of rivet joints for CMFM parts.

Heat and fluid flow properties of circular impinging jet with a low nozzle to plate spacing. Improvement by nothched nozzle; Nozzle heibankan kyori ga chiisai baai no enkei shototsu funryu no ryudo dennetsu tokusei. Kirikaki nozzle ni yoru kaizen kojo

Energy Technology Data Exchange (ETDEWEB)

Shakouchih, T. [Mie University, Mie (Japan). Faculty of Engineering; Matsumoto, A.; Watanabe, A.

2000-10-25

It is well known that as decreasing the nozzle to plate spacing considerably the heat transfer coefficient of circular impinging jet, which impinges to the plate normally, increases remarkably. At that time, the flow resistance of nozzle-plate system also increases rapidly. In this study, in order to reduce the flow resistance and to enhance the heat transfer coefficient of the circular impinging jet with a considerably low nozzle to plate spacing, a special nozzle with notches is proposed, and considerable improvement of the flow and heat transfer properties are shown. The mechanism of enhancement of the heat transfer properties is also discussed. (author)

Component assembly with shape memory polymer fastener for microrobots

International Nuclear Information System (INIS)

Kim, Ji-Suk; Lee, Dae-Young; Koh, Je-Sung; Jung, Gwang-Pil; Cho, Kyu-Jin

2014-01-01

Adhesives are generally used for the assembly of microrobots, whereas bolts, screws, or rivets are used for larger robots. Although adhesives are easy to apply, lightweight, and small, they cannot be used for repeated assembly and disassembly of parts. In this paper, we present a novel microfastener composed of a polyurethane-based shape memory polymer (SMP) that is lightweight and small but that is easily detached for disassembly. This was achieved by using the shape recovery and modulus change of the SMP. A sheet of macromolded SMP was laser machined into an I-beam-shaped rivet, and notches were added to the structure to prevent stress concentration. Pull-off tests showed that, as the notch radius increased, the disengagement strength of the rivet fastener decreased and the reusability increased. Through the elastoplastic model, a single SMP rivet was calculated to have maximum disengagement strength of 150 N cm −2 in the elastic range, depending on the notch radius. The fasteners were applied to a jumping microrobot. The legs and body were assembled with ten fasteners, which showed no permanent deformation after impact during jumping movements. The legs were easily replaced with ones of different stiffness by heating the engaged sites to make the fasteners compliant and detachable. The proposed detachable SMP microfasteners are particularly useful for testing the isolated performance of microrobot components to determine the optimal designs for these components. (paper)

A structural health monitoring fastener for tracking fatigue crack growth in bolted metallic joints

Science.gov (United States)

Rakow, Alexi Schroder

Fatigue cracks initiating at fastener hole locations in metallic components are among the most common form of airframe damage. The fastener hole site has been surveyed as the second leading initiation site for fatigue related accidents of fixed wing aircraft. Current methods for inspecting airframes for these cracks are manual, whereby inspectors rely on non-destructive inspection equipment or hand-held probes to scan over areas of a structure. Use of this equipment often demands disassembly of the vehicle to search appropriate hole locations for cracks, which elevates the complexity and cost of these maintenance inspections. Improved reliability, safety, and reduced cost of such maintenance can be realized by the permanent integration of sensors with a structure to detect this damage. Such an integrated system of sensors would form a structural health monitoring (SHM) system. In this study, an Additive, Interleaved, Multi-layer Electromagnetic (AIME) sensor was developed and integrated with the shank of a fastener to form a SHM Fastener, a new SHM technology targeted at detection of fastener hole cracks. The major advantages of the SHM Fastener are its installation, which does not require joint layer disassembly, its capability to detect inner layer cracks, and its capability to operate in a continuous autonomous mode. Two methods for fabricating the proposed SHM Fastener were studied. The first option consisted of a thin flexible printed circuit film that was bonded around a thin metallic sleeve placed around the fastener shank. The second option consisted of coating sensor materials directly to the shank of a part in an effort to increase the durability of the sensor under severe loading conditions. Both analytical and numerical models were developed to characterize the capability of the sensors and provide a design tool for the sensor layout. A diagnostic technique for crack growth monitoring was developed to complete the SHM system, which consists of the

Array elements for a DBS flat-plate antenna

Science.gov (United States)

Maddocks, M. C. D.

1988-07-01

The introduction of a direct broadcast by satellite (DBS) television service requires suitable receiving antennas to be available. An alternative to the parabolic dish antenna is a flat-plate antenna. The overall design of a circularly-polarized flat-plate antenna which can be mounted flat on the wall of a building has been considered in a companion Report. In this Report various types of elements are investigated and their advantages and disadvantages discussed. The most suitable element for use in a flat-plate array is identified as a linearly-polarized folded-dipole element; its performance is reported here. Linearly-polarized elements are found to perform better than circularly-polarized elements and could be used with a polarization converter to receive the circularly-polarized radiation that would be transmitted by DBS.

Reversible fastener clamp load monitor with continuous visual or remote readout

Science.gov (United States)

Hodge, Malcolm H.; Kausel, Theodore C., Jr.; Begley, Matthew R.

1998-03-01

SIMS has developed a simple means for detecting and monitoring both absolute and relative clamp load, or bolt tension, in fastener systems. More than twenty-five percent of automotive failures are known to be due to undetected loss of fastener clamp load. While the equivalent aerospace maintenance statistics are not known, the average automobile has 3,500 fasteners while a Boeing 747 has closer to one million. It is therefore anticipated that the new SensaBolt clamp load tracking system could find wide applications in the aerospace arena. We describe a visually-evident and retrofitted clamp load monitoring design which is based on the differential joint substrate compression at, and immediately adjacent to, the fastener location. This intrinsically-accurate indicator does not necessarily require alteration in either the bolt or nut geometries, thereby facilitating product introduction and retrofit in aging aircraft applications. In addition, SensaBolt's sole reliance on substrate compression renders it more accurate then torque wrench or turn-of-nut techniques. Readout may be accomplished by any of three principal methods: for those applications with ease of access to the sensor, loss of tension can be determined by direct visual inspection. Application of a standard wrench can then be made to restore the fastener's proper tightness, per the SensaBolt indicators. In those instances where line-of-sight is unimpeded and more formal inspection is desired, the SensaBolt may be interrogated by a laser scanner bar code reader. Finally, SensaBolt may be addressed by the SIMS fiber optic harness for those instances where full-time remote interrogation is desired.

Advantages of DVW reinforced moment transmitting timber joints with steel flitch plates for colum-beam application

NARCIS (Netherlands)

Leijten, A.J.M.; Brandon, D.; Haddad, Y.M.

2013-01-01

This paper presents a study into the moment-rotation aspects of dvw (densified veneer wood) reinforced timber connections with an inter-connecting flitch plate used as middle member. Previous studies showed that reinforcing dowel-type timber connections with dvw and using expanded tube fasteners

A novel model of photothermal diffusion (PTD) for polymer nano-composite semiconducting of thin circular plate

Science.gov (United States)

Lotfy, Kh.

2018-05-01

In this article, theoretical discussions for a novel mathematical-physical Photothermal diffusion (PTD) model in the generalized thermoelasticity theory with photothermal processes and chemical action are introduced. The mean idea of this model depends on the interaction between quasi-particles (plasma waves) that depends on the kind of the used materials, the mechanical forces acting on the surface, the generalized thermo and mass diffusion (due to coupling of temperature fields with thermal waves and chemical potential) and the elastic waves. The one dimensional Laplace transforms is used to obtain the exact solution for some physical and chemical quantities for a thin circular plate of a semiconducting polymer nanocomposite such as silicon (Si). New variables are deduced and discussed. The obtained results of the physical quantities are presented analytically and illustrated graphically with some important applications.

Review of Bolt Preload and Torque for Assembling Threaded Fasteners in Nuclear Power Plant

International Nuclear Information System (INIS)

Lee, Yong-Sung; Lee, Jae-Gon; Kang, Yong-Chul; Shin, Ki-Jong

2007-01-01

There are numerous threaded fasteners such as bolts, studs, nuts, cap screws and anchor bolts used in nuclear power plants(NPPs). The major applications of threaded fasteners are reactor coolant pressure boundary components, their internals and supports. With the increase of commercial operation period of NPPs, the incidents caused by degradation of threaded fasteners have been occurred. A large number of reported incidents are involved in the pressure boundary and major component supports. The degradation and failure of threaded fasteners is affected by material, preload and torque value at assembly, bolting practice, etc. It is very important to select appropriate bolt preload and decide assembly torque value because torque control using a torque wrench is the most common method in a power plant to assemble a bolted flange connection. Many researches have been studied to define the proper bolt preload and desired torque value with regard to the integrity of bolted connections including pressure boundary joints by EPRI and other plant industry. But in domestic NPPs, considerably few works are done on the bolted joint assembly in spite of increasing events related with threaded faster. Therefore we investigated degradation or failure of the threaded fasteners used in NPPs, also examined the codes, standards and technical trends concerning bolt preload and assembly torque in NPPs. It is the purpose of this study to provide proper technical information for assuring integrity of the threaded fasteners

Wave structure in the radial film flow with a circular hydraulic jump

Science.gov (United States)

Rao, A.; Arakeri, J. H.

A circular hydraulic jump is commonly seen when a circular liquid jet impinges on a horizontal plate. Measurements of the film thickness, jump radius and the wave structure for various jet Reynolds numbers are reported. Film thickness measurements are made using an electrical contact method for regions both upstream and downstream of the jump over circular plates without a barrier at the edge. The jump radius and the separation bubble length are measured for various flow rates, plate edge conditions, and radii. Flow visualization using high-speed photography is used to study wave structure and transition. Waves on the jet amplify in the film region upstream of the jump. At high flow rates, the waves amplify enough to cause three-dimensional breakdown and what seems like transition to turbulence. This surface wave induced transition is different from the traditional route and can be exploited to enhance heat and mass transfer rates.

Alloy and composition dependence of hydrogen embrittlement susceptibility in high-strength steel fasteners

Science.gov (United States)

Brahimi, S. V.; Yue, S.; Sriraman, K. R.

2017-06-01

High-strength steel fasteners characterized by tensile strengths above 1100 MPa are often used in critical applications where a failure can have catastrophic consequences. Preventing hydrogen embrittlement (HE) failure is a fundamental concern implicating the entire fastener supply chain. Research is typically conducted under idealized conditions that cannot be translated into know-how prescribed in fastener industry standards and practices. Additionally, inconsistencies and even contradictions in fastener industry standards have led to much confusion and many preventable or misdiagnosed fastener failures. HE susceptibility is a function of the material condition, which is comprehensively described by the metallurgical and mechanical properties. Material strength has a first-order effect on HE susceptibility, which increases significantly above 1200 MPa and is characterized by a ductile-brittle transition. For a given concentration of hydrogen and at equal strength, the critical strength above which the ductile-brittle transition begins can vary due to second-order effects of chemistry, tempering temperature and sub-microstructure. Additionally, non-homogeneity of the metallurgical structure resulting from poorly controlled heat treatment, impurities and non-metallic inclusions can increase HE susceptibility of steel in ways that are measurable but unpredictable. Below 1200 MPa, non-conforming quality is often the root cause of real-life failures. This article is part of the themed issue 'The challenges of hydrogen and metals'.

Three-Dimensional Heat Transfer Analysis of Metal Fasteners in Roofing Assemblies

Directory of Open Access Journals (Sweden)

Manan Singh

2016-11-01

Full Text Available Heat transfer analysis was performed on typical roofing assemblies using HEAT3, a three-dimensional heat transfer analysis software. The difference in heat transferred through the roofing assemblies considered is compared between two cases—without any steel fasteners and with steel fasteners. In the latter case, the metal roofing fasteners were arranged as per Factor Mutual Global (FMG approvals, in the field, perimeter, and corner zones of the roof. The temperature conditions used for the analysis represented summer and winter conditions for three separate Climate Zones (CZ namely Climate Zone 2 or CZ2 represented by Orlando, FL; CZ3 represented by Atlanta, GA; and CZ6 zone represented by St. Paul, MN. In all the climatic conditions, higher energy transfer was observed with increase in the number of metal fasteners attributed to high thermal conductivity of metals as compared to the insulation and other materials used in the roofing assembly. This difference in heat loss was also quantified in the form of percentage change in the overall or effective insulation of the roofing assembly for better understanding of the practical aspects. Besides, a comparison of 2D heat transfer analysis (using THERM software and 3D analysis using HEAT3 is also discussed proving the relevance of 3D over 2D heat transfer analysis.

Effects of long-term exposure on LDEF fastener assemblies

Science.gov (United States)

Spear, Steve; Dursch, Harry

1992-09-01

This presentation summarizes the Systems Special Investigations Group (SIG) findings from testing and analysis of fastener assemblies used on the Long Duration Exposure Facility (LDEF) structure, the tray mounting clamps, and by the various experimenters. The LDEF deintegration team and several experimenters noted severe fastener damage and hardware removal difficulties during post-flight activities. The System SIG has investigated all reported instances, and in all cases examined to date, the difficulties were attributed to galling during installation or post-flight removal. To date, no evidence of coldwelding was found. Correct selection of materials and lubricants as well as proper mechanical procedures is essential to ensure successful on-orbit or post-flight installation and removal of hardware.

Wave structure in the radial film flow with a circular hydraulic jump

Energy Technology Data Exchange (ETDEWEB)

Rao, A.; Arakeri, J.H. [Indian Inst. of Science, Bangalore (India). Dept. of Mechanical Engineering

2001-11-01

A circular hydraulic jump is commonly seen when a circular liquid jet impinges on a horizontal plate. Measurements of the film thickness, jump radius and the wave structure for various jet Reynolds numbers are reported. Film thickness measurements are made using an electrical contact method for regions both upstream and downstream of the jump over circular plates without a barrier at the edge. The jump radius and the separation bubble length are measured for various flow rates, plate edge conditions, and radii. Flow visualization using high-speed photography is used to study wave structure and transition. Waves on the jet amplify in the film region upstream of the jump. At high flow rates, the waves amplify enough to cause three-dimensional breakdown and what seems like transition to turbulence. This surface wave induced transition is different from the traditional route and can be exploited to enhance heat and mass transfer rates. (orig.)

Tempering of martensitic steel for fasteners: Effects of micro-alloying on microstructure and mechanical property evolution

OpenAIRE

Öhlund, C.E.I.C.

2015-01-01

The research presented in this thesis aims to deepen our understanding of the effect of micro-alloying on the microstructure and mechanical property evolution during tempering of martensitic steel for fasteners. The ongoing trend of engine down-sizing has led to the need for stronger and more temperature resistant fasteners than currently available according to international standards. A new martensitic fastener steel called KNDS4 has been developed, that combines higher strength with improve...

Torque Tension Testing of Fasteners used for NASA Flight Hardware Applications

Science.gov (United States)

Hemminger, Edgar G.; Posey, Alan J.; Dube, Michael J.

2014-01-01

The effect of various lubricants and other compounds on fastener torque-tension relationships is evaluated. Testing was performed using a unique test apparatus developed by Posey at the NASA Goddard Space Flight Center. A description of the test methodology, including associated data collection and analysis will be presented. Test results for 300 series CRES and A286 heat resistant fasteners, torqued into various types of inserts will be presented. The primary objective of this testing was to obtain torque-tension data for use on NASA flight projects.

Finite element analysis of inclined nozzle-plate junctions

International Nuclear Information System (INIS)

Dixit, K.B.; Seth, V.K.; Krishnan, A.; Ramamurthy, T.S.; Dattaguru, B.; Rao, A.K.

1979-01-01

Estimation of stress concentration at nozzle to plate or shell junctions is a significant problem in the stress analysis of nuclear reactors. The topic is a subject matter of extensive investigations and earlier considerable success has been reported on analysis for the cases when the nozzle is perpendicular to the plate or is radial to the shell. Analytical methods for the estimation of stress concentrations for the practical situations when the intersecting nozzle is inclined to the plate or is non-radial to the shell is rather scanty. Specific complications arise in dealing with the junction region when the nozzle with circular cross-section meets the non-circular cut-out on the plate or shell. In this paper a finite element analysis is developed for inclined nozzles and results are presented for nozzle-plate junctions. A method of analysis is developed with a view to achieving simultaneously accuracy of results and simplicity in the choice of elements and their connectivity. The circular nozzle is treated by axisymmetric conical shell elements. The nozzle portion in the region around the junction and the flat plate is dealt with by triangular flat shell elements. Special transition elements are developed for joining the flat shell elements with the axisymmetric elements under non-axisymmetric loading. A substructure method of analysis is adopted which achieves considerable economy in handling the structure and also conveniently combines the different types of elements in the structure. (orig.)

Aperture-based antihydrogen gravity experiment: Parallel plate geometry

Science.gov (United States)

Rocha, J. R.; Hedlof, R. M.; Ordonez, C. A.

2013-10-01

An analytical model and a Monte Carlo simulation are presented of an experiment that could be used to determine the direction of the acceleration of antihydrogen due to gravity. The experiment would rely on methods developed by existing antihydrogen research collaborations. The configuration consists of two circular, parallel plates that have an axis of symmetry directed away from the center of the earth. The plates are separated by a small vertical distance, and include one or more pairs of circular barriers that protrude from the upper and lower plates, thereby forming an aperture between the plates. Antihydrogen annihilations that occur just beyond each barrier, within a "shadow" region, are asymmetric on the upper plate relative to the lower plate. The probability for such annihilations is determined for a point, line and spheroidal source of antihydrogen. The production of 100,000 antiatoms is predicted to be necessary for the aperture-based experiment to indicate the direction of free fall acceleration of antimatter, provided that antihydrogen is produced within a sufficiently small antiproton plasma at a temperature of 4 K.

Aperture-based antihydrogen gravity experiment: Parallel plate geometry

Energy Technology Data Exchange (ETDEWEB)

Rocha, J. R.; Hedlof, R. M.; Ordonez, C. A. [Department of Physics, University of North Texas, Denton, Texas 76203 (United States)

2013-10-15

An analytical model and a Monte Carlo simulation are presented of an experiment that could be used to determine the direction of the acceleration of antihydrogen due to gravity. The experiment would rely on methods developed by existing antihydrogen research collaborations. The configuration consists of two circular, parallel plates that have an axis of symmetry directed away from the center of the earth. The plates are separated by a small vertical distance, and include one or more pairs of circular barriers that protrude from the upper and lower plates, thereby forming an aperture between the plates. Antihydrogen annihilations that occur just beyond each barrier, within a “shadow” region, are asymmetric on the upper plate relative to the lower plate. The probability for such annihilations is determined for a point, line and spheroidal source of antihydrogen. The production of 100,000 antiatoms is predicted to be necessary for the aperture-based experiment to indicate the direction of free fall acceleration of antimatter, provided that antihydrogen is produced within a sufficiently small antiproton plasma at a temperature of 4 K.

Aperture-based antihydrogen gravity experiment: Parallel plate geometry

Directory of Open Access Journals (Sweden)

J. R. Rocha

2013-10-01

Full Text Available An analytical model and a Monte Carlo simulation are presented of an experiment that could be used to determine the direction of the acceleration of antihydrogen due to gravity. The experiment would rely on methods developed by existing antihydrogen research collaborations. The configuration consists of two circular, parallel plates that have an axis of symmetry directed away from the center of the earth. The plates are separated by a small vertical distance, and include one or more pairs of circular barriers that protrude from the upper and lower plates, thereby forming an aperture between the plates. Antihydrogen annihilations that occur just beyond each barrier, within a “shadow” region, are asymmetric on the upper plate relative to the lower plate. The probability for such annihilations is determined for a point, line and spheroidal source of antihydrogen. The production of 100,000 antiatoms is predicted to be necessary for the aperture-based experiment to indicate the direction of free fall acceleration of antimatter, provided that antihydrogen is produced within a sufficiently small antiproton plasma at a temperature of 4 K.

Mounting Systems for Structural Members, Fastening Assemblies Thereof, and Vibration Isolation Systems Including the Same

Science.gov (United States)

Young, Ken (Inventor); Hindle, Timothy (Inventor); Barber, Tim Daniel (Inventor)

2016-01-01

Mounting systems for structural members, fastening assemblies thereof, and vibration isolation systems including the same are provided. Mounting systems comprise a pair of mounting brackets, each clamped against a fastening assembly forming a mounting assembly. Fastening assemblies comprise a spherical rod end comprising a spherical member having a through opening and an integrally threaded shaft, first and second seating members on opposite sides of the spherical member and each having a through opening that is substantially coaxial with the spherical member through opening, and a partially threaded fastener that threadably engages each mounting bracket forming the mounting assembly. Structural members have axial end portions, each releasably coupled to a mounting bracket by the integrally threaded shaft. Axial end portions are threaded in opposite directions for permitting structural member rotation to adjust a length thereof to a substantially zero strain position. Structural members may be vibration isolator struts in vibration isolation systems.

The impact force acting on a flat plate exposed normally to a rarefied plasma plume issuing from an annular or circular nozzle

Energy Technology Data Exchange (ETDEWEB)

Chen Xi, E-mail: cx-dem@mail.tsinghua.edu.c [Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China)

2010-08-11

With the indirect thrust measurement of electric thrusters working at a low vacuum chamber pressure as the research background, this paper analyses the impact force acting on a flat plate exposed normally to a rarefied plasma plume issuing from a thruster with an annular or circular exit section for the free-molecule flow regime (at large Knudsen numbers). The constraint relation proposed by Cai and Boyd (2007 J. Spacecr. Rockets 44 619, 1326) about the velocity components of gas particles leaving a location on the nozzle exit section and arriving at a given spatial point outside the nozzle has been employed here to derive the analytical expressions for calculating the impact force. Sample calculation results show that if the flat plate is sufficiently large, the impact force acting on the flat plate calculated for the case without accounting for gas particle reflection at the plate surface agrees well with the axial momentum flux calculated at the thruster exit or the theoretical thrust force of the studied thruster, while accounting for the contribution of gas particles reflected from the plate surface to the impact force production may significantly increase the calculated impact force acting on the flat plate. For a Hall-effect thruster in which the thrust force is dominantly produced by the ions with high directional kinetic energy and the ions are not directly reflected from the plate surface, the contribution to the impact force production of atom species and of gas particles reflected from the plate surface is negligibly small and thus the measured axial impact force acting on a sufficiently large plate can well represent the thrust force of the thruster. On the other hand, if the contribution of the gas particles reflected from the plate surface to the impact force production cannot be neglected (e.g. for the electric thrusters with comparatively low thruster exit temperatures), appreciable error would appear in the indirect thrust measurement.

Comparing the performances of circular ponds with different impellers by CFD simulation and microalgae culture experiments.

Science.gov (United States)

Meng, Chen; Huang, Jianke; Ye, Chunyu; Cheng, Wenchao; Chen, Jianpei; Li, Yuanguang

2015-07-01

In this study, a numerical simulation using computational fluid dynamics (CFD) was used to investigate the hydrodynamic characteristics of circular ponds with three different impellers (hydrofoil, four-pitched-blade turbine, and grid plate). The reliability of the CFD model was validated by particle image velocimetry (PIV). Hydrodynamic analyses were conducted to evaluate the average velocity magnitude along the light direction (Uz), turbulence properties, average shear stress, pressure loss and the volume percentage of dead zone inside circular ponds. The simulation results showed that Uz value of hydrofoil was 58.9, 40.3, and 28.8% higher than those of grid plate with single arm, grid plate with double arms and four-pitched blade turbines in small-scale circular ponds, respectively. In addition, hydrofoil impeller with down-flow operation had outstanding mixing characteristics. Lastly, the results of Chlorella pyrenoidosa cultivation experiments indicated that the biomass concentration of hydrofoil impeller with down-flow operation was 65.2 and 88.8% higher than those of grid plate with double arms and four-pitched-blade turbine, respectively. Therefore, the optimal circular pond mixing system for microalgae cultivation involved a hydrofoil impeller with down-flow operation.

Finite element analysis of adanced composite structures containing mechanically fastened joints

International Nuclear Information System (INIS)

Baumann, E.

1982-01-01

Although the usual engineering practice is to ignore joint effects in finite element models of overall structures, there are times when the inclusion of fastener effects in a model is necessary for accurate analysis. This paper describes some simple but accurate methods for accommodating this modeling requirement. The approach involves correlation of test results from a few composite mechanically fastened joints with finite element analyses of joints. It is assumed that if the fastener actions in the test articles can be properly predicted by simple finite element techniques, then these same techniques can be applied to large overall structure models. During the course of this test-analysis effort it was determined that it is possible to obtain correct results for overall structure-joint analyses by using simple modeling concepts provided special care is employed. Also, some emphasis is given in this paper to the importance of properly reducing test data in order to obtain meaningful correlations with finite element analysis. Finally, for those interested, the appendix contains brief descriptions of the test results and failure modes explored in the test program. (orig.)

NRC Bulletin No. 87-02, Supplement 1: Fastener testing to determine conformance with applicable material specifications

International Nuclear Information System (INIS)

Rossi, C.E.

1992-01-01

Item 5 of NRC Compliance Bulletin 87-02 requested that all holders of operating licenses or construction permits for nuclear power reactors information regarding the identity of the suppliers and manufacturers of the safety-related and non-safety-related fasteners selected for testing. After further consideration, the NRC has determined that it needs information regarding the identity of all vendors from which safety-related and non-safety-related fasteners have been obtained within the past 10 years, a reasonable period which will not put undue burden on addressees. This information will assist the NRC in determining whether nuclear facility fasteners in use have been supplied in accordance with their intended use. In addition, this information is needed so that the NRC can properly coordinate information with other government agencies concerned with problems identified in the quality of fasteners

Smart fastener for KC-135 structural integrity monitoring

Science.gov (United States)

Schoess, Jeffrey N.; Seifert, Greg

1997-06-01

Hidden and inaccessible corrosion in aircraft structures is the number-one logistics problem for the U.S. Air Force, with an estimated maintenance cost in excess of $DOL1.0 billion per year in 1990-equivalent dollars. The Smart Aircraft Fastener Evaluation (SAFE) system is being developed to provide early warning detection of corrosion- related symptoms in hidden locations of aircraft structures. The SAFE incorporates an in situ measurement approach that measures and autonomously records several environmental conditions (i.e., pH, temperature, chloride, free potential, time-of-wetness) within a Hi-Lok aircraft fastener that could cause corrosion to occur. The SAFE system integrates a miniature electrochemical microsensor array and a time-of- wetness sensor with an ultra-low-power 8-bit microcontroller and 5-Mbyte solid-state FLASH archival memory to measure the evidence of active corrosion. A summary of the technical approach, system design definition, software architecture, and future field test plans will be presented.

EFFECT OF VARIOUS POROUS STRUCTURES ON THE SHLIOMIS MODEL BASED FERROFLUID LUBRICATION OF THE FILM SQUEEZED BETWEEN ROTATING ROUGH CURVED CIRCULAR PLATES

Directory of Open Access Journals (Sweden)

Jimit R Patel

2014-12-01

Full Text Available Efforts have been made to analyze the Shliomis model based ferrofluid lubrication of a squeeze film between rotating rough curved circular plates where the upper plate has a porous facing. Different models of porosity are treated. The stochastic modeling of Christensen and Tonder has been employed to evaluate the effect of surface roughness. The related stochastically averaged Reynolds type equation is numerically solved to obtain the pressure distribution, leading to the calculation of load carrying capacity. The results presented in graphical form establish that the Kozeny-Carman model is more favorable as compared to the Irmay one from the design point of view. It is observed that the Shliomis model based ferrofluid lubrication performs relatively better than the Neuringer-Rosensweig one. Although the bearing suffers due to transverse surface roughness, with a suitable choice of curvature parameters and rotational ratio, the negative effect of porosity and standard deviation can be minimized by the ferrofluid lubrication at least in the case of negatively skewed roughness.

Initial experience with percutaneous endoscopic gastrostomy with T-fastener fixation in pediatric patients

Science.gov (United States)

Kvello, Morten; Knatten, Charlotte Kristensen; Perminow, Gøri; Skari, Hans; Engebretsen, Anders; Schistad, Ole; Emblem, Ragnhild; Bjørnland, Kristin

2018-01-01

Background and study aims  Insertion of a percutaneous endoscopic gastrostomy (PEG) with push-through technique and T-fastener fixation (PEG-T) has recently been introduced in pediatric patients. The T-fasteners allow a primary insertion of a balloon gastrostomy. Due to limited data on the results of this technique in children, we have investigated peri- and postoperative outcomes after implementation of PEG-T in our department. Patients and methods  This retrospective chart review included all patients below 18 years who underwent PEG-T placement from 2010 to 2014. Main outcomes were 30-day postoperative complications and late gastrostomy-related complications. Results  In total, 87 patients were included, and median follow-up time was 2.4 years (1 month – 4.9 years). Median age and weight at PEG-T insertion were 1.9 years (9.4 months – 16.4 years) and 10.4 kg (5.4 – 33.0 kg), respectively. Median operation time was 28 minutes (10 – 65 minutes), and 6 surgeons and 3 endoscopists performed the procedures. During the first 30 days, 54 complications occurred in 41 patients (47 %). Most common were peristomal infections treated with either local antibiotics in 11 patients (13 %) or systemic antibiotics in 11 other patients (13 %). 9 patients (10 %) experienced tube dislodgment. Late gastrostomy-related complications occurred in 33 patients (38 %). The T-fasteners caused early and late complications in 9 (10 %) and 11 patients (13 %), respectively. Of these, 4 patients (5 %) had subcutaneously migrated T-fasteners which were removed under general anesthesia. Conclusion  We found a high rate of complications after PEG-T. In particular, problems with the T-fasteners and tube dislodgment occurred frequently after PEG-T insertion. PMID:29399615

Instantaneous mechanical fastening of quasi-isotropic CFRP laminates by a self-piercing rivet

OpenAIRE

上田, 政人; 三宅, 崇太郎; 長谷川, 寛幸; 平野, 義鎭; Ueda, Masahito; Miyake, Sotaro; Hasegawa, Hiroyuki; Hirano, Yoshiyasu

2012-01-01

A modified self-piercing rivet (SPR) has been proposed to mechanically fasten CFRP laminates. The modified SPR consists of a rivet body and two flat washers. The two flat washers were used to suppress delamination in the CFRP laminates at the point of piercing. The advantages of the modified SPR for fastening CFRP laminates are instantaneous process time and low cost. Any pretreatments such as surface treatments or hole drilling are not required. In this study, the viability of the modified S...

Nanomechanical testing of circular freestanding polymer films with sub-micron thickness

International Nuclear Information System (INIS)

Maner, Kyle C.; Begley, Matthew R.; Oliver, Warren C.

2004-01-01

This paper describes techniques to create freestanding films over perfectly circular spans (windows) and measure their mechanical properties using instrumented nanoindentation. Test samples were created by spin-casting polymer films over glass plates with embedded fibers, which were subsequently etched using a relatively weak acid to leave freestanding circular spans. The freestanding spans were tested using an instrumented nanoindenter over a wide range of applied loads and displacements. Material properties can be extracted from measured load-deflection responses using straightforward models for point-loads on circular plates or membranes. Results are presented for poly(methyl methacrylate) and poly(2,6,dimethyl,1,4,phenylene ether) films with thickness ranging from 350 to 750 nm. The properties derived from freestanding tests are compared with traditional nanoindentation of films on intact substrates. The freestanding approach has key advantages for characterizing micron-scale behavior of compliant materials, notably greater ease and applicability of sample preparation over other micro-fabrication techniques and straightforward analytical or numerical models

What foods are US supermarkets promoting? A content analysis of supermarket sales circulars.

Science.gov (United States)

Martin-Biggers, Jennifer; Yorkin, Meredith; Aljallad, Carena; Ciecierski, Caroline; Akhabue, Ivbaria; McKinley, Jessica; Hernandez, Katherine; Yablonsky, Courtney; Jackson, Rachel; Quick, Virginia; Byrd-Bredbenner, Carol

2013-03-01

This study compared the types of foods advertised in supermarket newspaper circulars across geographic region (US Census regions: northeast [n=9], midwest [n=15], south [n=14], and west [n=13]), obesity-rate region (i.e., states with CDC adult obesity rates of advertisements on the first page of each circular were measured (±0.12-in.) to determine the proportion of space occupied and categorized according to food group. Overall, ≥ 50% of the front page of supermarket sales circulars was devoted to protein foods and grains; fruits, vegetables, and dairy, combined, were allocated only about 25% of the front page. The southern geographic region and the highest obesity-rate region both devoted significantly more advertising space to sweets, particularly sugar-sweetened beverages. The lowest obesity-rate region and western geographic region allocated the most space to fruits. Vegetables were allocated the least space in the western geographic region. Grains were the only food group represented in ads in proportions approximately equal to amounts depicted in the MyPlate icon. Protein foods exceeded and fruits, dairy, and vegetables fell below comparable MyPlate proportional areas. Findings suggest supermarket ads do not consistently emphasize foods that support healthy weight and MyPlate recommendations. More research is needed to determine how supermarket newspaper circulars can be used to promote healthy dietary patterns. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nonlinear Coupled Dynamics of a Rod Fastening Rotor under Rub-Impact and Initial Permanent Deflection

Directory of Open Access Journals (Sweden)

Liang Hu

2016-10-01

Full Text Available A nonlinear coupled dynamic model of a rod fastening rotor under rub-impact and initial permanent deflection was developed in this paper. The governing motion equation was derived by the D’Alembert principle considering the contact characteristic between disks, nonlinear oil-film force, rub-impact force, unbalance mass, etc. The contact effects between disks was modeled as a flexural spring with cubical nonlinear stiffness. The coupled nonlinear dynamic phenomena of the rub-impact rod fastening rotor bearing system with initial permanent deflection were investigated by the fourth-order Runge-Kutta method. Bifurcation diagram, vibration waveform, frequency spectrum, shaft orbit and Poincaré map are used to illustrate the rich diversity of the system response with complicated dynamics. The studies indicate that the coupled dynamic responses of the rod fastening rotor bearing system under rub-impact and initial permanent deflection exhibit a rich nonlinear dynamic diversity, synchronous periodic-1 motion, multiple periodic motion, quasi-periodic motion and chaotic motion can be observed under certain conditions. Larger radial stiffness of the stator will simplify the system motion and make the oil whirl weaker or even disappear at a certain rotating speed. With the increase of initial permanent deflection length, the instability speed of the system gradually rises, and the chaotic motion region gets smaller and smaller. The corresponding results can provide guidance for the fault diagnosis of a rub-impact rod fastening rotor with initial permanent deflection and contribute to the further understanding of the nonlinear dynamic characteristics of the rod fastening rotor bearing system.

Stresses and strains in thick perforated orthotropic plates

Science.gov (United States)

A. Alshaya; John Hunt; R. Rowlands

2016-01-01

Stress and strain concentrations and in-plane and out-of-plane stress constraint factors associated with a circular hole in thick, loaded orthotropic composite plates are determined by three-dimensional finite element method. The plate has essentially infinite in-plane geometry but finite thickness. Results for Sitka Spruce wood are emphasized, although some for carbon...

Performance of Rail Fastening Systems on an Open-Deck Bridge

Science.gov (United States)

2018-02-01

Transportation Technology Center, Inc. (TTCI) monitored the performance of rail fasteners on an open-deck bridge and its approaches, located at Norfolk Southern Corporations (NS's) eastern mega site. The project was co-sponsored by the Federal Rai...

Deep Defect Detection within Thick Multilayer Aircraft Structures Containing Steel Fasteners Using a Giant-Magneto Resistive (GMR) Sensor (Preprint)

National Research Council Canada - National Science Library

Ko, Ray T; Steffes, Gary J

2007-01-01

Defect detection within thick multilayer structures containing steel fasteners is a challenging task in eddy current testing due to the magnetic permeability of the fasteners and overall thickness of the structure...

Evaluation of the seat fastening in the frame of a road bus submitted to frontal impact

Directory of Open Access Journals (Sweden)

Márcio Walber

Full Text Available The collective intercity transportation by bus is currently a mean of locomotion much sought after by people. Security in accidents is a very important factor that must be taken into account in design of bus body structure, being the evaluation of passenger safety of this type of vehicle is an important subject that should be checked, because in many accidents occur disconnection between seats and fastening members causing serious passengers injury, often fatal. This work aims at evaluation the behavior of frame fixing of seats of intercity bus bodies, submitted to the frontal impact situation in a rigid wall of 100% offset, through evaluation by finite element method (FEM. This study uses a numerical model corresponding to the body structure and chassis, developed through flexible beam elements, combining with shell elements for the structure of the seats and its fastening members, with the objective of not missing the essential aspects of the problem, allowing the solution with a reduced computational time. The numerical model of bus body and seat was impacted against a rigid wall at a speed of 8.89 m/s, being its validation according to the deceleration curve established by Regulation 80. Then it was gotten the Von Mises stress in fastening members of the seat structure in bus body. It is also presented a proposal to improve the fastening of the seat structure, comparing the results of the stress gotten in the two types fastening submitted to the frontal impact.

Discrimination between Fatigue Cracking and Mechanical Damage in Aircraft Fastener Holes by Eddy-Current Phase Rotation

Science.gov (United States)

2016-08-01

Science and Technology Organisation) EDM Electrodischarge machining FSH Full Screen Height on an eddy - current instrument IVD Ion Vapour...electromagnetic skin depth δ is 0.15 mm in the fastener holes3. 4.1 Bolt Hole Eddy Current Inspection Procedure 4.1.1 Calibration on Machined ...UNCLASSIFIED UNCLASSIFIED Discrimination between Fatigue Cracking and Mechanical Damage in Aircraft Fastener Holes by Eddy - Current Phase

Vibration of an Elastic Circular Plate on an Elastic Half Space

DEFF Research Database (Denmark)

Krenk, Steen; Schmidt, H.

1981-01-01

The axisymmetric problem of a vibrating elastic plate on an elastic half space is solved by a direct method, in which the contact stresses and the normal displacements of the plate are taken as the unknown functions. First, the influence functions that give the displacements in terms...

Characterization of a microfocused circularly polarized x-ray probe

International Nuclear Information System (INIS)

Pollmann, J.; Srajer, G.; Maser, J.; Lang, J. C.; Nelson, C. S.; Venkataraman, C. T.; Isaacs, E. D.

2000-01-01

We report on the development of a circularly polarized x-ray microprobe in the intermediate energy range from 5 to 10 keV. In this experiment linearly polarized synchrotron radiation was circularly polarized by means of a Bragg-diffracting diamond phase retarder and subsequently focused down to a spot size of about 4x2 μm 2 by a Fresnel zone plate. The properties of the microprobe were characterized, and the technique was applied to the two-dimensional mapping of magnetic domains in HoFe 2 . (c) 2000 American Institute of Physics

Fatigue of anchors for the fastening of wind turbines to reinforced concrete foundations. Vermoeiing van ankers voor de bevestiging van windmolens aan fundaties van gewapend beton

Energy Technology Data Exchange (ETDEWEB)

Liemberg, B J; Bouwman, L P

1983-01-01

Nowadays slender and slack masts are preferred for wind turbines, fastened to a concrete foundation with anchor bolts. This concept leads to strongly fluctuating forces. Tests are described to investigate this aspect of wind turbine design. Test specimens were designed and loaded in such a way that the real situation was simulated as close as possible. They were subjected to fatigue tests and duration tests. Some important conclusions are: foot plates with two contact surfaces are significantly better than those with only one contact surface; a good filling of the seam, especially in a direct line with the mast is essential.

Pull-in instability tuning in imperfect nonlinear circular microplates under electrostatic actuation

Energy Technology Data Exchange (ETDEWEB)

Jallouli, A.; Kacem, N., E-mail: najib.kacem@univ-fcomte.fr; Bourbon, G.; Le Moal, P.; Walter, V.; Lardies, J.

2016-12-01

Highlights: • Dynamic range improvement of electrostatically actuated circular microplates. • Pull-in instability tuning based on geometric nonlinearity and imperfections. • Predictive computational model for the nonlinear behavior of circular microplates. - Abstract: Dynamic range improvement based on geometric nonlinearity and initial deflection is demonstrated with imperfect circular microplates under electrostatic actuation. Depending on design parameters, we prove how the von Kármán nonlinearity and the plate imperfections lead to a significant delay in pull-in occurrence. These promising results open the way towards an accurate identification of static parameters of circular microplates and the development of a predictive model for the nonlinear dynamics of imperfect capacitive micromachined ultrasonic transducers.

Buckling and postbuckling behavior of square compression-loaded graphite-epoxy plates with circular cutouts

Science.gov (United States)

Nemeth, Michael P.

1990-01-01

Results are presented for unidirectional (0, 10)(sub s) and (90,10)(sub s) plates, ((0/90)(sub 5)(sub s)) plates, and for aluminum plates. Results are also presented for ((+/- theta)(sub 6)(sub s)) angle-ply plates for values of theta = 30, 45, and 60 degrees. The results indicate that the change in axial stiffness of a plate at buckling is strongly dependent upon cutout size and plate orthotropy. The presence of a cutout gives rise to an internal load distribution that changes, sometimes dramatically, as a function of cutout size coupled with the plate orthotropy. In the buckled state, the role of orthotropy becomes more significant since bending in addition to membrane orthotropy is present. Most of the plates with cutouts exhibited less postbuckling stiffness than the corresponding plate without a cutout, and the postbuckling stiffness decreased with increasing cutout size. However, some of the highly orthotropic plates with cutouts exhibited more postbuckling stiffness than the corresponding plate without a cutout. These results suggest the possibility of tailoring the cutout size and the stacking sequence of a composite plate to optimize postbuckling stiffness. It was found that plates with large radius cutouts do exhibit some postbuckling strength. The results also indicate that a cutout can influence modal interaction in a plate. Specifically, results are presented that show a plate with a relatively small cutout buckling at a higher load than the corresponding plate without a cutout, due to modal interaction. Other results are presented that indicate the presence of nonlinear prebuckling deformations, due to material nonlinearity, in the angle-ply plates with theta = 45 and 60 degrees. The nonlinear prebuckling deformations are more pronounced in the plates with theta = 45 degrees and become even more pronounced as the cutout size increases. Results are also presented that show how load-path eccentricity due to improper machining of the test specimens

Experiments of flow-induced in-line oscillation of a circular cylinder in a water tunnel. 2. Influence of the aspect ratio of a cantilevered circular cylinder

International Nuclear Information System (INIS)

Nakamura, Akira; Okajima, Atsushi; Kosugi, Takashi

2001-01-01

The flow-induced in-line oscillation of a cantilevered circular cylinder was experimentally studied through free-oscillation tests in a water tunnel. The response displacement amplitude at a circular cylinder tip was measured at reduced velocity from 1.0 to 4.0. A cantilevered cylinder was supported by a plate spring mounted on the water tunnel wall. The cylinder aspect ratio was varied from 5 to 21 to investigate the effect of aspect ratio on the response displacement. It is found that cylinders with aspect ratios of 5 and 10 have one excitation region, while cylinders with aspect ratios of 14 and 21 have two excitation regions. The aspect ratio, therefore, affects the amplitude of the excitation regions. The influence of end-effect was also investigated using cylinders with an end plate attached to the free end. Since the cylinders with an end plate show two excitation regions, even at an aspect ratio of 5, the flow around the free end of a cantilevered cylinder causes the end-effect. The mechanism of vibration was investigated using a cylinder with a splitter plate in wake to prevent alternate vortices. The amplitude is greater than those of a normal cylinder without a splitter plate, especially at V r =2.3 to 3.0, where a cylinder with an end plate shows the second excitation region. In order words, the alternate vortices suppress the amplitude in this range. The maximum amplitude of each excitation region decreases in proportion to C n and the amplitude of the first excitation is more sensitive to C n . (author)

Theroretical modelling of the plate-tubes coupling in the hydroelasticity of the perforated plates

International Nuclear Information System (INIS)

Dzhupanov, V.A.; Manoach, E.S.

1983-01-01

In the previous investigations on the perforated plate hydroelasticity the problem of the plates-tubes-liquid interaction in the process of the general structural vibration is stated. But the interaction of the vibrating plates with the tubes, passing through them, is taken into account considering the tubes only as absolutely rigid supports. This is one of the possible technical realizations. In the present article the case when the tubes are taking part in the plate motion (vibration) is studied. Two circular perforated plates are supported by the absolutely rigid wall of the modelled roundcircular reactor barrel. The distance between the plates is given. They are connected by tubes, passing through, and clamped into the perforation holes. The plates and the tubes are made by any elastic HOOKIAN material. The volume between the two plates and outwardly to the tubes, but intrinsically of the barrel is filled by ideal, compressible and heavy liquid. Evidently the liquid volume is multiconnected one. The free vibration of the whole system is considered with the purposes: i) to give a theoretical model of the plates-tubes-liquid interaction including governing equations and boundary conditions; ii) to trace the solution of the eigen-value problem for the modelled structure; iii) to underline the engineering sides of the modelling process. (orig./GL)

Performance of wickless heat pipe flat plate solar collectors having different pipes cross sections geometries and filling ratios

International Nuclear Information System (INIS)

Hussein, H.M.S.; El-Ghetany, H.H.; Nada, S.A.

2006-01-01

In the present study, the effect of wickless heat pipe cross section geometry and its working fluid filling ratio on the performance of flat plate solar collectors has been investigated experimentally. Three groups of wickless heat pipes having three different cross section geometries (namely, circular, elliptical and semi-circular cross sections) were designed and manufactured. Each group of three wickless heat pipes was charged with three different distilled water filling ratios of 10%, 20% and 35%. Each wickless heat pipe was then incorporated into a prototype flat plate solar collector developed for the purpose of the present study. The prototypes wickless heat pipe flat plate solar collectors have been investigated experimentally at different inlet cooling water temperatures, two different cooling water mass flow rates and under the meteorological conditions of Cairo, Egypt. The experimental results indicate that the elliptical cross section wickless heat pipe flat plate solar collectors have better performance than the circular cross section ones at low water filling ratios. The optimum water filling ratio of the elliptical cross section wickless heat pipe solar collector is about 10%, while it is very close to 20% for the circular cross section one. Also, the water filling ratio corresponding to the flooding limit of the elliptical wickless heat pipe solar collector is lower than that of the circular one. At 20% water filling ratio, the semi-circular cross section wickless heat pipe solar collector has bad performance compared with that of the other cross sections

Wear plates control rod guide tubes top internal reactor vessel C. N. VANDELLOS II; Desgaste placas tubos guia barras de control interno superior vasija del reactor C.N. Vandellos II

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

The guide tubes for control rods forming part of the upper internals of the reactor vessel, its function is to guide the control rod to permit its insertion in the reactor core. These guide tubes are suspended from the upper support plate which are fixed by bolts and extending to the upper core plate which is fastened by clamping bolts (split pin) to prevent lateral displacement of the guide tubes, while allowing axial expansion.

Test results of smart aircraft fastener for KC-135 structural integrity

Science.gov (United States)

Schoess, Jeffrey N.; Seifert, Greg

1998-07-01

Hidden and inaccessible corrosion in aircraft structures is the number one logistics problem for the US Air Force, with an estimated maintenance cost in excess of $LR 1.0B per year in 1990-equivalent dollars. The Smart Aircraft Fastener Evaluation (SAFE) system was developed to provide early warning detection of corrosion-related symptoms in hidden locations of aircraft structures. The SAFE system incorporates an in situ measurement approach that measures and autonomously records several environmental conditions within a Hi-Lok aircraft fastener that could cause corrosion. The SAFE system integrates a miniature electrochemical microsensor array and a time-of-wetness sensor with an ultra low power 8-bit microcontroller and 4- Mbyte solid-state FLASH archival memory to measure evidence of active corrosion. A summary of the technical approach and a detailed analysis of the KC-135 lap joint test coupon results are presented.

Thermal effects on the stability of circular graphene sheets via nonlocal continuum mechanics

Directory of Open Access Journals (Sweden)

Saeid Reza Asemi

Full Text Available Recently, graphene sheets have shown significant potential for environmental engineering applications such as wastewater treatment. Different non-classical theories have been used for modeling of such nano-sized systems to take account of the effect of small length scale. Among all size-dependent theories, the nonlocal elasticity theory has been commonly used to examine the stability of nano-sized structures. Some research works have been reported about the mechanical behavior of rectangular nanoplates with the consideration of thermal effects. However, in comparison with the rectangular graphene sheets, research works about the nanoplates of circular shape are very limited, especially for the buckling properties with thermal effects. Hence, in this paper, an axisymmetric buckling analysis of circular single-layered graphene sheets (SLGS is presented by decoupling the nonlocal equations of Eringen theory. Constitutive relations are modified to describe the nonlocal effects. The governing equations are derived using equilibrium equations of the circular plate in polar coordinates. Numerical solutions for buckling loads are computed using Galerkin method. It is shown that nonlocal effects play an important role in the buckling of circular nanoplates. The effects of the small scale on the buckling loads considering various parameters such as the radius of the plate, radius-to-thickness ratio, temperature change and mode numbers are investigated.

Flow Phenomena in the Very Near Wake of a Flat Plate with a Circular Trailing Edge

Science.gov (United States)

Rai, Man Mohan

2014-01-01

The very near wake of a flat plate with a circular trailing edge, exhibiting pronounced shedding of wake vortices, is investigated with data from a direct numerical simulation. The separating boundary layers are turbulent and statistically identical thus resulting in a wake that is symmetric in the mean. The focus here is on the instability of the detached shear layers, the evolution of rib-vortex induced localized regions of reverse flow that detach from the main body of reverse flow in the trailing edge region and convect downstream, and phaseaveraged velocity statistics in the very near wake. The detached shear layers are found to exhibit unstable behavior intermittently, including the development of shear layer vortices as in earlier cylinder flow investigations with laminar separating boundary layers. Only a small fraction of the separated turbulent boundary layers undergo this instability, and form the initial shed vortices. Pressure spectra within the shear layers show a broadband peak at a multiple of shedding frequency. Phase-averaged intensity and shear stress distributions of the randomly fluctuating component of velocity are compared with those obtained in the near wake. The distributions of the production terms in the transport equations for the turbulent stresses are also provided.

A New Limit on CMB Circular Polarization from SPIDER

Science.gov (United States)

Nagy, J. M.; Ade, P. A. R.; Amiri, M.; Benton, S. J.; Bergman, A. S.; Bihary, R.; Bock, J. J.; Bond, J. R.; Bryan, S. A.; Chiang, H. C.; Contaldi, C. R.; Doré, O.; Duivenvoorden, A. J.; Eriksen, H. K.; Farhang, M.; Filippini, J. P.; Fissel, L. M.; Fraisse, A. A.; Freese, K.; Galloway, M.; Gambrel, A. E.; Gandilo, N. N.; Ganga, K.; Gudmundsson, J. E.; Halpern, M.; Hartley, J.; Hasselfield, M.; Hilton, G.; Holmes, W.; Hristov, V. V.; Huang, Z.; Irwin, K. D.; Jones, W. C.; Kuo, C. L.; Kermish, Z. D.; Li, S.; Mason, P. V.; Megerian, K.; Moncelsi, L.; Morford, T. A.; Netterfield, C. B.; Nolta, M.; Padilla, I. L.; Racine, B.; Rahlin, A. S.; Reintsema, C.; Ruhl, J. E.; Runyan, M. C.; Ruud, T. M.; Shariff, J. A.; Soler, J. D.; Song, X.; Trangsrud, A.; Tucker, C.; Tucker, R. S.; Turner, A. D.; Van Der List, J. F.; Weber, A. C.; Wehus, I. K.; Wiebe, D. V.; Young, E. Y.

2017-08-01

We present a new upper limit on cosmic microwave background (CMB) circular polarization from the 2015 flight of Spider, a balloon-borne telescope designed to search for B-mode linear polarization from cosmic inflation. Although the level of circular polarization in the CMB is predicted to be very small, experimental limits provide a valuable test of the underlying models. By exploiting the nonzero circular-to-linear polarization coupling of the half-wave plate polarization modulators, data from Spider's 2015 Antarctic flight provide a constraint on Stokes V at 95 and 150 GHz in the range 33< {\\ell }< 307. No other limits exist over this full range of angular scales, and Spider improves on the previous limit by several orders of magnitude, providing 95% C.L. constraints on {\\ell }({\\ell }+1){C}{\\ell }{VV}/(2π ) ranging from 141 to 255 μK2 at 150 GHz for a thermal CMB spectrum. As linear CMB polarization experiments become increasingly sensitive, the techniques described in this paper can be applied to obtain even stronger constraints on circular polarization.

Mechanical fasteners used in historical Siberian shipbuilding: perspectives for metallurgical analysis

Science.gov (United States)

Goncharov, A. E.; Mednikov, D. M.; Karelin, N. M.; Nasyrov, I. R.

2017-10-01

Recent discoveries of shipwrecked vessels in the northern reaches of the river Yenisei led to a number of questions concerning the history of shipbuilding in Siberia and the technical features of the first vessels of the industrial era to navigate the Northern Sea Route and the Yenisei. One of these questions addresses the features of mechanical fasteners used in the construction of the Siberian vessels. The answer to this question may provide information on how the first vessels, constructed in Siberia during the 1870’s, were able to sail the high seas of the Arctic Ocean and reach European ports. In this paper, we provide a description of iron mechanical fasteners obtained from one shipwrecked vessel and discuss on the perspectives of a metallurgical analysis This research has been funded by a grant of the Russian Fund of Humanities Research (Russian Fund of Fundamental Research) and the Krasnoyarsk Regional Science Fund under Grant number 16-11-24010.

Advances and Trends in Plate Buckling Research.

Science.gov (United States)

1982-12-01

Hydrostatic State of In- Plane Stress. Instituto de Mecanica Aplicada No. 79-21 (Puerto Belgrano, Argentina), June 1979, 10 pp. (to be published). 38. Leissa...and Elastic Stability of Circular Plates With Thickness Varying in a Bilinear Fashion. Instituto de Mecanica Aplicada No. 81-23 (Puerto Belgrano

Stress state in perforated plates

International Nuclear Information System (INIS)

Visner, J.

1977-01-01

The method is described of photoelastic measurement of stress concentration factors (s.c.f) in plates perforated by a square, triangular and diagonal grid of circular holes and loaded by uniaxial or biaxial tensile stress. A loading equipment which was developed and its modifications are described. Stress concentration factors found are compared with theoretical and experimental results given in references. (author)

Bolt and nut evaluator

Science.gov (United States)

Kerley, James J.; Burkhardt, Raymond; White, Steven

1994-02-01

A device for testing fasteners such as nuts and bolts is described which consists of a fixed base plate having a number of threaded and unthreaded holes of varying size for receiving the fasteners to be tested, a torque marking paper taped on top the fixed base plate for marking torque-angle indicia, a torque wrench for applying torque to the fasteners being tested, and an indicator for showing the torque applied to the fastener. These elements provide a low cost, nondestructive device for verifying the strength of bolts and nuts.

Free vibration analysis of a rotary smart two directional functionally graded piezoelectric material in axial symmetry circular nanoplate

Science.gov (United States)

Mahinzare, Mohammad; Ranjbarpur, Hosein; Ghadiri, Majid

2018-02-01

In this article, free vibration of a rotating circular nanoplate made of two directional functionally graded piezo materials (two directional FGPM) is modeled based on the first shear deformation theory (FSDT). Based on the power-law model, electro-elastic properties of two directional FGP rotating circular nanoplates are supposed to change continuously along the thickness and radius. Employing the modified couple stress theory, the small size effect of the equations of the plate is considered. The governing equations of the first shear deformation theory (FSDT) for the studied plate are obtained based on Hamilton's principle; these equations are solved using differential quadrature method (DQM). It is shown that the vibration behavior of the plate is significantly affected by angular velocity, external electric voltage, size dependency and power-law index (thickness and radial directions).

Dowel-type fastener connections in timber structures subjected to short-term loading

DEFF Research Database (Denmark)

Lauritzen Jensen, J.

Design of dowel-type fastener connections in framed timber structures usually involves a two-step analysis: determination of the distribution of the sectional forces, and design of the eccentrically loaded connections. This report presents an integrated model for design of framed timber structures...

Testing of Compact Bolted Fasteners with Insulation and Friction-Enhanced Shims for NCSX

International Nuclear Information System (INIS)

Dudek, L.E.; Chrzanowski, J.H.; Gettelfinger, G.; Heitzenroeder, P.; Jurczynski, S.; Viola, M.; Freudenberg, K.

2009-01-01

The fastening of the National Compact Stellarator Experiment's (NCSX) modular coils presented a number of engineering and manufacturing challenges due to the high magnetic forces, need to control induced currents, tight tolerances and restrictive space envelope. A fastening method using high strength studs, jack nuts, insulating spacers, bushings and alumina coated shims was developed which met the requirements. A test program was conducted to verify the design. The tests included measurements of flatness of the spacers, determination of contact area, torque vs. tension of the studs and jack nuts, friction coefficient tests on the alumina and G-10 insulators, electrical tests, and tension relaxation tests due to temperature excursions from room temperature to liquid nitrogen temperatures. This paper will describe the design and the results of the test program.

Exposure testing of fasteners in preservative treated wood: Gravimetric corrosion rates and corrosion product analyses

Energy Technology Data Exchange (ETDEWEB)

Zelinka, Samuel L., E-mail: szelinka@fs.fed.u [USDA Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI 53726 (United States); Sichel, Rebecca J. [College of Engineering, University of Wisconsin, Madison, WI 53706 (United States); Stone, Donald S. [Department of Materials Science and Engineering, College of Engineering, University of Wisconsin, Madison, WI 53706 (United States)

2010-12-15

Research highlights: {yields} The composition of the corrosion products was similar for the nail head and shank. {yields} Reduced copper was not detected on any of the fasteners. {yields} Measured corrosion rates were between 1 and 35 {mu}m year{sup -1}. - Abstract: Research was conducted to determine the corrosion rates of metals in preservative treated wood and also understand the mechanism of metal corrosion in treated wood. Steel and hot-dip galvanized steel fasteners were embedded in wood treated with one of six preservative treatments and exposed to 27 {sup o}C at 100% relative humidity for 1 year. The corrosion rate was determined gravimetrically and the corrosion products were analyzed with scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. Although the accepted mechanism of corrosion in treated wood involves the reduction of cupric ions from the wood preservative, no reduced copper was found on the corrosion surfaces. The galvanized corrosion products contained sulfates, whereas the steel corrosion products consisted of iron oxides and hydroxides. The possible implications and limitations of this research on fasteners used in building applications are discussed.

Administrative Circulars

CERN Document Server

Département des Ressources humaines

2004-01-01

Administrative Circular N° 2 (Rev. 2) - May 2004 Guidelines and procedures concerning recruitment and probation period of staff members This circular has been revised. It cancels and replaces Administrative Circular N° 2 (Rev. 1) - March 2000. Administrative Circular N° 9 (Rev. 3) - May 2004 Staff members contracts This circular has been revised. It cancels and replaces Administrative Circular N° 9 (Rev. 2) - March 2000. Administrative Circular N° 26 (Rev. 4) - May 2004 Procedure governing the career evolution of staff members This circular has also been revised. It Administrative Circulars Administrative Circular N° 26 (Rev. 3) - December 2001 and brings up to date the French version (Rev. 4) published on the HR Department Web site in January 2004. Operational Circular N° 7 - May 2004 Work from home This circular has been drawn up. Operational Circular N° 8 - May 2004 Dealing with alcohol-related problems...

Eddy current heating of irregularly shaped plates by slow ramped fields

International Nuclear Information System (INIS)

Dresner, L.

1979-01-01

Theorems are presented for estimating eddy current heating of irregularly shaped plates by a perpendicular ramped field. The theorems, which are derived from two complementary variational principles, give upper and lower bounds to the eddy current heating. Illustrative results are given for rectangles, isosceles triangles, sectors of circular annuli, rhombuses, and L-shaped plates. A comparison is made with earlier work

Velcro-like fasteners based on NiTi micro-hook arrays

Czech Academy of Sciences Publication Activity Database

Vokoun, David; Sedlák, Petr; Frost, Miroslav; Pilch, Jan; Majtás, Dušan; Šittner, Petr

2011-01-01

Roč. 20, č. 8 (2011), 085027/1-085027/13 ISSN 0964-1726 R&D Projects: GA ČR GAP108/10/1296; GA ČR GA106/09/1573 Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z20760514 Keywords : Nitinol * martensitic transformation * Finite Element Method * Velcro-like fastener Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.089, year: 2011

Linear to Circular Polarisation Conversion using Birefringent Properties of Aligned Crystals for Multi-GeV Photons

CERN Document Server

Apyan, A.; Badelek, B.; Ballestrero, S.; Biino, C.; Birol, I.; Cenci, P.; Connell, S.H.; Eichblatt, S.; Fonseca, T.; Freund, A.; Gorini, B.; Groess, R.; Ispirian, K.; Ketel, T.J.; Kononets, Yu.V.; Lopez, A.; Mangiarotti, A.; van Rens, B.; Sellschop, J.P.F.; Shieh, M.; Sona, P.; Strakhovenko, V.; Uggerhoj, E.; Uggerhj, Ulrik Ingerslev; Unel, G.; Velasco, M.; Vilakazi, Z.Z.; Wessely, O.; Kononets, Yu.V.

2003-01-01

We present the first experimental results on the use of a thick aligned Si crystal acting as a quarter wave plate to induce a degree of circular polarisation in a high energy linearly polarised photon beam. The linearly polarised photon beam is produced from coherent bremsstrahlung radiation by 178 GeV unpolarised electrons incident on an aligned Si crystal, acting as a radiator. The linear polarisation of the photon beam is characterised by measuring the asymmetry in electron-positron pair production in a Ge crystal, for different crystal orientations. The Ge crystal therefore acts as an analyser. The birefringence phenomenon, which converts the linear polarisation to circular polarisation, is observed by letting the linearly polarised photons beam pass through a thick Si quarter wave plate crystal, and then measuring the asymmetry in electron-positron pair production again for a selection of relative angles between the crystallographic planes of the radiator, analyser and quarter wave plate. The systematics...

Natural convection heat transfer from a vertical circular tube sheet

International Nuclear Information System (INIS)

Dharne, S.P.; Gaitonde, U.N.

1996-01-01

Experiments were conducted to determine natural convection heat transfer coefficients (a) on a plain vertical circular plate, and (b) on a similar plate with a square array of non-conducting tubes fixed in it. The experiments were carried out using air as the heat transfer medium. The diameter of the brass plates used was 350 mm. The diameter of the bakelite tubes used was 19.2 mm. The range of Rayleigh numbers was from 1.06x10 8 to 1.66x10 8 . The results show that the heat transfer coefficients in case (a) are very close to those obtained using standard correlations for vertical flat plates, whereas for case (b) the heat transfer coefficients are at least 50 percent higher than those predicted by the Churchill-Chu correlation. It is hence concluded that the disturbance to boundary layer caused by the presence of tubes enhances the heat transfer coefficient significantly. (author). 4 refs., 3 figs

Plate forming and break down pizza box

Science.gov (United States)

Pantisano, Frank; Devine, Scott M.

1992-01-01

A standard corrugated paper pizza box is provided with slit cuts cut through the top panel of the pizza box in a shape to form four circular serving plates with a beveled raised edge and cross slit cuts through the bottom panel of the pizza box separating the box into four essentially equal portions for easy disposal.

Comparison of the corrosion of fasteners embedded in wood measured in outdoor exposure with the predictions from a combined hygrothermal-corrosion model

Science.gov (United States)

Samuel L. Zelinka; Samuel V. Glass; Charles R. Boardman; Dominique Derome

2016-01-01

This paper examines the accuracy of a recently developed hygrothermal-corrosion model which predictsthe corrosion of fasteners embedded in wood by comparing the results of the model to a one year fieldtest. Steel and galvanized steel fasteners were embedded into untreated and preservative treated woodand exposed outdoors while weather data were collected. Qualitatively...

Modeling of plates with multiple anisotropic layers and residual stress

DEFF Research Database (Denmark)

Engholm, Mathias; Pedersen, Thomas; Thomsen, Erik Vilain

2016-01-01

Usually the analytical approach for modeling of plates uses the single layer plate equation to obtain the deflection and does not take anisotropy and residual stress into account. Based on the stress–strain relation of each layer and balancing stress resultants and bending moments, a general...... multilayered anisotropic plate equation is developed for plates with an arbitrary number of layers. The exact deflection profile is calculated for a circular clamped plate of anisotropic materials with residual bi-axial stress.From the deflection shape the critical stress for buckling is calculated......, and an excellent agreement between the two models is seen with a relative difference of less than 2% for all calculations. The model was also used to extract the cell capacitance, the parasitic capacitance and the residual stress of a pressure sensor composed of a multilayered plate of silicon and silicon oxide...

Cross-linkable liposomes stabilize a magnetic resonance contrast-enhancing polymeric fastener.

Science.gov (United States)

Smith, Cartney E; Kong, Hyunjoon

2014-04-08

Liposomes are commonly used to deliver drugs and contrast agents to their target site in a controlled manner. One of the greatest obstacles in the performance of such delivery vehicles is their stability in the presence of serum. Here, we demonstrate a method to stabilize a class of liposomes that load gadolinium, a magnetic resonance (MR) contrast agent, as a model cargo on their surfaces. We hypothesized that the sequential adsorption of a gadolinium-binding chitosan fastener on the liposome surface followed by covalent cross-linking of the lipid bilayer would provide enhanced stability and improved MR signal in the presence of human serum. To investigate this hypothesis, liposomes composed of diyne-containing lipids were assembled and functionalized via chitosan conjugated with a hydrophobic anchor and diethylenetriaminepentaacetic acid (DTPA). This postadsorption cross-linking strategy served to stabilize the thermodynamically favorable association between liposome and polymeric fastener. Furthermore, the chitosan-coated, cross-linked liposomes proved more effective as delivery vehicles of gadolinium than uncross-linked liposomes due to the reduced liposome degradation and chitosan desorption. Overall, this study demonstrates a useful method to stabilize a broad class of particles used for systemic delivery of various molecular payloads.

Temperature-field measurements of a premixed butane/air circular impinging-flame using reference-beam interferometry

International Nuclear Information System (INIS)

Qi, J.A.; Leung, C.W.; Wong, W.O.; Probert, S.D.

2006-01-01

Reference-beam interferometry (RBI) was applied to study the axisymmetric temperature fields of a small-scale, low Reynolds-number, low-pressure and fuel-rich premixed butane/air circular-flame jet, when it was impinging vertically upwards onto a horizontal copper plate. By maintaining a Reynolds number, Re, of 500 and an equivalence ratio, φ, of 1.8, interferograms of the impinging-flame jet were obtained for various nozzle-to-plate-distances. Temperature fields of the flame were then determined using the inverse Abel transformation from the obtained interferograms. Temperatures at several locations were measured experimentally with a T-type thermocouple: they were used as a reference to help in the determination as well as the validation. In the present study, a non-contact method has been successfully developed to measure the temperature fields of a circular impinging gas-fired flame jet

Development technique for deep drawing without blank holder to produce circular cup of brass alloy

OpenAIRE

Ali Hassan Saleh; Ammer Khalaf Ali

2015-01-01

Of this technique compared to the conventional deep drawing is that the circular cup can be carried out in single action press with limit In this paper a new mechanism for deep drawing was proposed to produce circular cup from thin plate without blank holder. In this technique the die assembly includes punch, die and die-punch. A 2D axisymmetric finite element model was built using DEFORM software. Effect of die geometry (half- cone angle) on maximum load, thickness distribution, strain distr...

Foods advertised in US weekly supermarket sales circulars over one year: a content analysis.

Science.gov (United States)

Jahns, Lisa; Payne, Collin R; Whigham, Leah D; Johnson, LuAnn K; Scheett, Angela J; Hoverson, Bonita S; Kranz, Sibylle

2014-09-23

The nutritional content of Americans' shopping carts is suboptimal despite federal dietary guidance, in this case, the MyPlate consumer icon which displays desired proportions of vegetables, fruits, dairy, grains and protein foods for consumption. Consumers mention print advertising-such as weekly sales circulars-frequently as influencing their grocery shopping decisions. To examine and describe the relative proportions of advertised foods aggregated into the MyPlate food grouping system, a content analysis of 9 209 foods advertised in 52 weekly supermarket newspaper sales inserts in 2009 from a local grocery chain was conducted in a Midwestern community. Overall, the protein foods group was most often represented in sales circulars (25% of total items), followed by grains (18%); dairy (10%); vegetables (8%) and fruits (7%). Less than 3% of sales advertisements were for dark green and red & orange vegetables. Over twice as much whole fruit versus 100% fruit juice was advertised (70% vs. 30%, respectively; P advertised in the fall, and slightly more dark green vegetables were advertised in winter and spring than in summer and fall (P = 0.05). The average American diet, including underconsumption of fruits and vegetables but overconsumption of protein foods, was reflected in the relative frequency of food groups advertised in weekly sales circulars. Modifying sales circulars to represent healthier food groups may preserve retail profits (considering these groups' higher profit margin) while promoting adherence to federal dietary guidance.

The effect of moisture content on the corrosion of fasteners embedded in wood subjected to alkaline copper quaternary treatment

International Nuclear Information System (INIS)

Zelinka, Samuel L.; Glass, Samuel V.; Derome, Dominique

2014-01-01

Highlights: • We examine the dependence of metal corrosion on wood moisture content. • Corrosion of steel and galvanized steel in treated wood were measured. • Corrosion products were analyzed across moisture contents using X-ray diffraction. • The corrosion rate has a sigmoidal dependence on moisture content. • The data herein can be used to improve combined hygrothermal–corrosion models. - Abstract: This paper characterizes the corrosion rate of embedded fasteners as a function of wood moisture content using gravimetric and electrochemical measurements. The results indicated that the corrosion rate increased with moisture content before reaching a plateau. The phases present in the corrosion products, as analyzed using X-ray diffraction, are generally consistent with previous work. Uniform corrosion was observed for all fasteners and all conditions except steel fasteners embedded in water-saturated wood. Data of dependence of corrosion rate on moisture content, presented herein, are necessary to ensure the accuracy of combined hygrothermal/corrosion models used to predict durability of wood structures

Fabrication procedures for HFIR control plates

Energy Technology Data Exchange (ETDEWEB)

Bowden, G.A.; Hicks, G.R.; Knight, R.W.

1984-10-01

The HFIR control system uses Alclad cylindrically shaped components, which have regions containing 31 vol % Eu/sub 2/O/sub 3/ and 38 vol % Ta, respectively. Exacting control of the water passage between these components and adjacent reactor parts is mandatory, and precise dimensional control of the finished products is required. This report describes the procedures developed for manufacturing outer control plates and inner control cylinders. Results are cited which demonstrate that circular-shaped outer control plates can be produced with less than 0.025-in. variation from the specified 9.300-in. radius in any region of the plate. Other results show that, by the exercise of careful control, inner control, inner control plates can be welded into cylindrical geometry with diametrical variations held to less than +- 0.010 in. of the intended 17.846-in. average diam. The cylinders can then be explosively sized, while under compression, with diametric variations of less than 0.005 in. while controlling roundness variations to less than 0.030 in. from the specified 17.842-in. finished diam.

Fabrication procedures for HFIR control plates

International Nuclear Information System (INIS)

Bowden, G.A.; Hicks, G.R.; Knight, R.W.

1984-10-01

The HFIR control system uses Alclad cylindrically shaped components, which have regions containing 31 vol % Eu 2 O 3 and 38 vol % Ta, respectively. Exacting control of the water passage between these components and adjacent reactor parts is mandatory, and precise dimensional control of the finished products is required. This report describes the procedures developed for manufacturing outer control plates and inner control cylinders. Results are cited which demonstrate that circular-shaped outer control plates can be produced with less than 0.025-in. variation from the specified 9.300-in. radius in any region of the plate. Other results show that, by the exercise of careful control, inner control, inner control plates can be welded into cylindrical geometry with diametrical variations held to less than +- 0.010 in. of the intended 17.846-in. average diam. The cylinders can then be explosively sized, while under compression, with diametric variations of less than 0.005 in. while controlling roundness variations to less than 0.030 in. from the specified 17.842-in. finished diam

"Service Recovery: The Effects of Complaint Handling on Post-complaint Relationship Intention and Customer Switching Behaviour in the Taiwan Fastener Industry"

OpenAIRE

Hwang, Jui-Chin

2005-01-01

Abstract In recent decades, many industries have started to realize the importance of relationship marketing and effective complaint handling as part of their customer retention strategies. This includes the traditional Taiwan fastener industry, which used to be considered as more technically focused rather than service-oriented. One of the main reasons for this industry to move toward a service orientation is that Taiwanese fastener trading companies have become highly customer-focused, ...

Experimental Research on the Elastic Deformation Mode of S235JR Rolled Steel Fastened between the Centers of a Universal Lathe

Science.gov (United States)

Tabacaru, LL; Axinte, E.; Musca, G.

2016-11-01

Elastic deformations of the technological system occur during the mechanical treatment of a blank, regardless of the manner in which it is fastened. The elastic deformation of the blank is significant especially when machining shaft-like parts. The purpose of our research is to compare the mathematical model of blank deformation to the experimental model when the blank, which is a part belonging to the shaft class, is fastened between centers.

Comparison study of multistep forging and injection forging of automobile fasteners

OpenAIRE

Chen Senyong; Qin Yi

2015-01-01

In order to improve production efficiency, injection forging as a feasible approach was introduced to automobile fasteners production. In the study reported in this paper, two forging approaches, traditional multistep forging and injection forging, were analysed by using a finite element method. Using ABAQUS and DEFORM, some significant factors, namely, forging force, energy consumption, component accuracy and stress distribution in the die, were compared to explore the potential and challeng...

Thin-plate spline quadrature of geodetic integrals

Science.gov (United States)

Vangysen, Herman

1989-01-01

Thin-plate spline functions (known for their flexibility and fidelity in representing experimental data) are especially well-suited for the numerical integration of geodetic integrals in the area where the integration is most sensitive to the data, i.e., in the immediate vicinity of the evaluation point. Spline quadrature rules are derived for the contribution of a circular innermost zone to Stoke's formula, to the formulae of Vening Meinesz, and to the recursively evaluated operator L(n) in the analytical continuation solution of Molodensky's problem. These rules are exact for interpolating thin-plate splines. In cases where the integration data are distributed irregularly, a system of linear equations needs to be solved for the quadrature coefficients. Formulae are given for the terms appearing in these equations. In case the data are regularly distributed, the coefficients may be determined once-and-for-all. Examples are given of some fixed-point rules. With such rules successive evaluation, within a circular disk, of the terms in Molodensky's series becomes relatively easy. The spline quadrature technique presented complements other techniques such as ring integration for intermediate integration zones.

CFD Analysis to Study Effect of Circular Vortex Generator Placed in Inlet Section to Investigate Heat Transfer Aspects of Solar Air Heater

Directory of Open Access Journals (Sweden)

Vipin B. Gawande

2014-01-01

Full Text Available CFD analysis of 2-dimensional artificially roughened solar air heater duct with additional circular vortex generator, inserted in inlet section is carried out. Circular transverse ribs on the absorber plate are placed as usual. The analysis is done to investigate the effect of inserting additional vortex generator on the heat transfer and flow friction characteristics inside the solar air heater duct. This investigation covers relative roughness pitch in the range of 10 ≤ P/e ≤ 25 and relevant Reynolds numbers in the range of 3800 ≤ Re ≤ 18000. Relative roughness height (e/D is kept constant as 0.03 for analysis. The turbulence created due to additional circular vortex generator increases the heat transfer rate and at the same time there is also increase in friction factor values. For combined arrangement of ribs and vortex generator, maximum Nusselt number is found to be 2.05 times that of the smooth duct. The enhancement in Nusselt number with ribs and additional vortex generator is found to be 1.06 times that of duct using ribs alone. The maximum increase in friction factor with ribs and circular vortex generator is found to be 2.91 times that of the smooth duct. Friction factor in a combined arrangement is 1.114 times that in a duct with ribs alone on the absorber plate. The augmentation in Thermal Enhancement Factor (TEF with vortex generator in inlet section is found to be 1.06 times more than with circular ribs alone on the absorber plate.

CFD analysis to study effect of circular vortex generator placed in inlet section to investigate heat transfer aspects of solar air heater.

Science.gov (United States)

Gawande, Vipin B; Dhoble, A S; Zodpe, D B

2014-01-01

CFD analysis of 2-dimensional artificially roughened solar air heater duct with additional circular vortex generator, inserted in inlet section is carried out. Circular transverse ribs on the absorber plate are placed as usual. The analysis is done to investigate the effect of inserting additional vortex generator on the heat transfer and flow friction characteristics inside the solar air heater duct. This investigation covers relative roughness pitch in the range of 10 ≤ P/e ≤ 25 and relevant Reynolds numbers in the range of 3800 ≤ Re ≤ 18000. Relative roughness height (e/D) is kept constant as 0.03 for analysis. The turbulence created due to additional circular vortex generator increases the heat transfer rate and at the same time there is also increase in friction factor values. For combined arrangement of ribs and vortex generator, maximum Nusselt number is found to be 2.05 times that of the smooth duct. The enhancement in Nusselt number with ribs and additional vortex generator is found to be 1.06 times that of duct using ribs alone. The maximum increase in friction factor with ribs and circular vortex generator is found to be 2.91 times that of the smooth duct. Friction factor in a combined arrangement is 1.114 times that in a duct with ribs alone on the absorber plate. The augmentation in Thermal Enhancement Factor (TEF) with vortex generator in inlet section is found to be 1.06 times more than with circular ribs alone on the absorber plate.

IMPLEMENTATION OF THE LEAN-KAIZEN APPROACH IN FASTENER INDUSTRIES USING THE DATA ENVELOPMENT ANALYSIS

Directory of Open Access Journals (Sweden)

Sunil Kumar

2017-04-01

Full Text Available This research paper is an attempt to improve the quality system of ten small scale fastener manufacturing industries through the implementation of the Lean-Kaizen approach using the Data Envelopment Analysis (DEA Charnes Cooper & Rhodes (CCR model with constant returns to scale (CRS. Output maximization is taken as the objective function to identify the percentage scope of improvements. The data is collected by paying personal visits to the selected industries for three inputs (manpower, maintenance, and training of employees and two outputs (quality, on-time delivery of their quality system. The DEA CCR model is applied to identify efficiency scores of the quality system by taking the most efficient industry as a benchmark for the rest of the organizations. The Lean-Kaizen approach is applied to identify waste / non-value added activities in outputs of the selected industries. Four Kaizen events are proposed to eliminate waste / non-value added activities in their quality system. The data collected after the Kaizen events are further analyzed by the DEA CCR model. The improvements in efficiency scores of the selected industries are presented as findings in this research paper. Two fastener industries became 100% efficient while the rest of the organizations reported 8% to 49% improvements in their efficiency scores of the quality system. The conclusions are made as the Lean-Kaizen using DEA is found to be an effective approach to improve the quality system of fastener industries. This study will be beneficial for researchers, practitioners and academicians for tackling the inefficiencies in the organization.

Full-Field Stress Determination Around Circular Discontinuity in a Tensile-Loaded Plate using x-displacements Only

Science.gov (United States)

Baek, Tae Hyun; Chung, Tae Jin; Panganiban, Henry

The significant effects of stress raisers demand well-defined evaluation techniques to accurately determine the stress along the geometric boundary. A simple and accurate method for the determination of stress concentration around circular geometric discontinuity in a tensile-loaded plate is illustrated. The method is based on the least-squares technique, mapping functions, and a complex power series representation (Laurent series) of the stress functions for the calculation of tangential stress around the hole. Traction-free conditions were satisfied at the geometric discontinuity using conformal mapping and analytic continuation. In this study, we use only a relatively small amount of x-component displacement data of points away from the discontinuity of concern with their respective coordinates. Having this information we can easily obtain full-field stresses at the edge of the geometric discontinuity. Excellent results were obtained when the number of terms of the power series expansions, m=1. The maximum stress concentration calculation results using the present method and FEM using ANSYS agree well by less than one per cent difference. Experimental advantage of the method underscores the use of relatively small amount of data which are conveniently determined being away from the edge. Moreover, the small amount of measured input data needed affords the approach suitable for applications such as the multi-parameter concept used to obtain stress intensity factors from measured data. The use of laser speckle interferometry and moiré interferometry are also potential future related fields since the optical system for one-directional measurement is much simple.

Circular Coinduction

Science.gov (United States)

Rosu, Grigore; Goguen, Joseph; Norvig, Peter (Technical Monitor)

2001-01-01

Circular coinduction is a technique for behavioral reasoning that extends cobasis coinduction to specifications with circularities. Because behavioral satisfaction is not recursively enumerable, no algorithm can work for every behavioral statement. However. algorithms using circular coinduction can prove every practical behavioral result that we know. This paper proves the correctness of circular coinduction and some consequences.

Modified Vertical Bearing Capacity for Circular Foundations in Sand Using Reduced Friction Angle

DEFF Research Database (Denmark)

Ibsen, Lars Bo; Barari, Amin; Larsen, Kim André

2012-01-01

Recently Bucket foundation as a large cylindrical structure that is open as the base and closed at the top, has attracted much attention in offshore projects. In order to present relationship between vertical bearing capacity of a bucket foundation relative to the corresponding capacity of a circ......Recently Bucket foundation as a large cylindrical structure that is open as the base and closed at the top, has attracted much attention in offshore projects. In order to present relationship between vertical bearing capacity of a bucket foundation relative to the corresponding capacity...... of a circular plate, several loading tests on small scale bucket foundations including the circular surface footings are performed at Aalborg University. In current research, the vertical bearing capacity of circular surface footings is investigated using reduced friction angle. It is also presented a linear...

Three Dimensional Parametric Analyses on Effect of Fibre Orientation for Stress Concentration Factor in Fibrous Composite Cantilever Plate with Central Circular Hole under Transverse Loading

Directory of Open Access Journals (Sweden)

Nitin Jain

2012-10-01

Full Text Available Normal 0 false false false EN-IN X-NONE X-NONE ABSTRACT: A number of analytical and numerical techniques are available for the two dimensional study of stress concentration around the hole(s in isotropic and composite plates subjected to in-plane or transverse loading conditions. The information on the techniques for three dimensional analyses of stress concentration factor (SCF around the hole in isotropic and composite plates subjected to transverse loading conditions is, however, limited. The present work emphasizes on the effect of fibre orientation (q on the stress concentration factor in fibrous composite plates with central circular hole under transverse static loading condition. The work is carried out for cantilever fibrous composite plates. The effects of thickness -to- width (T/A and diameter-to-width (D/A ratios upon SCF at different fibre orientation are studied. Plates of four different composite materials were considered for hole analysis in order to determine the sensitivity of SCF with elastic constants. Deflections in transverse direction were calculated and analysed. All results are presented in graphical form and discussed. The finite element formulation and its analysis were carried out using ANSYS package.ABSTRAK: Terdapat pelbagai teknik analitikal dan numerical untuk kajian tumpuan tegasan dua dimensi di sekeliling lubang-lubang dalam komposit isotropik dan plat pada satah atau keadaan bebanan melintang. Bagaimanapun, maklumat mengenai kaedah analisis tiga dimensi untuk faktor ketumpatan tegasan (SCF sekitar lubang dalam komposit isotropik dan plat pada keadaan bebanan melintang adalah terhad. Kertas ini menekankan kesan orientasi gentian (q pada faktor tumpuan tegasan dalam komposit plat bergentian dengan lubang berpusat di bawah keadaan bebanan melintang. Kajian ini dilkukan untuk cantilever plat komposit bergentian. Kesan ketebalan terhadap kelebaran plat (T/A dan diameter terhadap kelebaran komposit (D/A dengan SCF

Automatic Defect Detection of Fasteners on the Catenary Support Device Using Deep Convolutional Neural Network

NARCIS (Netherlands)

Chen, Junwen; Liu, Zhigang; Wang, H.; Nunez Vicencio, Alfredo; Han, Zhiwei

2018-01-01

The excitation and vibration triggered by the long-term operation of railway vehicles inevitably result in defective states of catenary support devices. With the massive construction of high-speed electrified railways, automatic defect detection of diverse and plentiful fasteners on the catenary

Circular Solutions

NARCIS (Netherlands)

Annevelink, E.; Bos, H.L.; Meesters, K.P.H.; Oever, van den M.J.A.; Haas, de W.; Kuikman, P.J.; Rietra, R.P.J.J.; Sikirica, N.

2016-01-01

The fifth part of this report on Circular Solutions is about the circular principle From Waste to Resource. The purpose of this study is to select promising options for the implementation of this circular principle and to elaborate these options further.

Experimental study of bolted connections using light gauge channel sections and packing plates at the joints

Science.gov (United States)

Kulkarni, Ravindra B.; Vaghe, Vishal M.

2014-12-01

Cold-formed structural members are being used more widely in routine structural design as the world steel industry moves from the production of hot-rolled section and plate to coil and strip, often with galvanized and/or painted coatings. Steel in this form is more easily delivered from the steel mill to the manufacturing plant where it is usually cold-rolled into open and closed section members. In the present experimental study, the use of packing plate at the joints in cold-formed channel sections may increase the load carrying capacity and also reduce the buckling of unconnected cold form channel steel plate at joints. The present study focuses on examining the experimental investigation to use mild steel as a packing plate with cold-formed channel sections by bolted connection at the joints and the connection subjected to axial tension. Series of tests are carried out with increase in the thickness of packing plate and results are observed and analyzed. Total Twelve experimental tests have been carried out on cold-formed channel tension members fastened with single as well as three numbers of bolts at the connection and from the observations the strength of the joint is increased by increasing the various thicknesses of packing plates and also the buckling of unconnected leg of channel specimen is reduced. It is analyzed by plotting the entire load versus elongation path, so that the behavior of the connection is examined.

Operational circular No. 1 (Rev. 1) – Operational circulars

CERN Multimedia

HR Department

2011-01-01

Operational Circular No. 1 (Rev. 1) is applicable to members of the personnel and other persons concerned. Operational Circular No. 1 (Rev. 1) entitled "Operational circulars", approved following discussion at the Standing Concertation Committee meeting on 4 May 2011, is available on the intranet site of the Human Resources Department: https://hr-docs.web.cern.ch/hr-docs/opcirc/opcirc.asp It cancels and replaces Operational Circular No. 1 entitled "Operational Circulars” of December 1996. This new version clarifies, in particular, that operational circulars do not necessarily arise from the Staff Rules and Regulations, and the functional titles have been updated to bring them into line with the current CERN organigram. Department Head Office  

An Integrated Approach to Assess Exposure and Health-Risk from Polycyclic Aromatic Hydrocarbons (PAHs in a Fastener Manufacturing Industry

Directory of Open Access Journals (Sweden)

Hsin-I Hsu

2014-09-01

Full Text Available An integrated approach was developed to assess exposure and health-risk from polycyclic aromatic hydrocarbons (PAHs contained in oil mists in a fastener manufacturing industry. One previously developed model and one new model were adopted for predicting oil mist exposure concentrations emitted from metal work fluid (MWF and PAHs contained in MWF by using the fastener production rate (Pr and cumulative fastener production rate (CPr as predictors, respectively. By applying the annual Pr and CPr records to the above two models, long-term workplace PAH exposure concentrations were predicted. In addition, true exposure data was also collected from the field. The predicted and measured concentrations respectively served as the prior and likelihood distributions in the Bayesian decision analysis (BDA, and the resultant posterior distributions were used to determine the long-term exposure and health-risks posed on workers. Results show that long term exposures to PAHs would result in a 3.1%, 96.7%, and 73.4% chance of exceeding the PEL-TWA (0.2 mg/m3, action level (0.1 mg/m3, and acceptable health risk (10−3, respectively. In conclusion, preventive measures should be taken immediately to reduce workers’ PAH exposures.

Simplified description of out-of-plane waves in thin annular elastic plates

DEFF Research Database (Denmark)

Zadeh, Maziyar Nesari; Sorokin, Sergey

2013-01-01

Dispersion relations are derived for the out-of-plane wave propagation in planar elastic plates with constant curvature using the classical Kirchhoff thin plate theory. The dispersion diagrams and the mode shapes are compared with their counterparts for a straight plate strip and the role...... of curvature is assessed for plates with unconstrained edges. Elementary Bernoulli–Euler theory for a beam of rectangular cross-section with the circular shape of its axis is also employed to analyze the wave guide properties of this structure in its out-of-plane deformation. The applicability range...... of the elementary beam theory is validated. The wave finite element method in the formulation of the three-dimensional elasticity theory is used to ensure that the comparison of dispersion diagrams is performed in the frequency range, where the classical thin plate theory is valid. Thus, the paper summarizes...

Smart aircraft fastener evaluation (SAFE) system: a condition-based corrosion detection system for aging aircraft

Science.gov (United States)

Schoess, Jeffrey N.; Seifert, Greg; Paul, Clare A.

1996-05-01

The smart aircraft fastener evaluation (SAFE) system is an advanced structural health monitoring effort to detect and characterize corrosion in hidden and inaccessible locations of aircraft structures. Hidden corrosion is the number one logistics problem for the U.S. Air Force, with an estimated maintenance cost of $700M per year in 1990 dollars. The SAFE system incorporates a solid-state electrochemical microsensor and smart sensor electronics in the body of a Hi-Lok aircraft fastener to process and autonomously report corrosion status to aircraft maintenance personnel. The long-term payoff for using SAFE technology will be in predictive maintenance for aging aircraft and rotorcraft systems, fugitive emissions applications such as control valves, chemical pipeline vessels, and industrial boilers. Predictive maintenance capability, service, and repair will replace the current practice of scheduled maintenance to substantially reduce operational costs. A summary of the SAFE concept, laboratory test results, and future field test plans is presented.

Estimation for bolt fastening conditions of thin aluminum structure using PZT sensors

International Nuclear Information System (INIS)

Hong, Yong; Han, Byeong Hee; Kim, Byung Jin; Hong, Dong Pyo; Kim, Young Moon

2007-01-01

This work presents a study on PZT impedance-based method, it is one of the NDT(Non-Destructive Technique). We study about assessment of the square-structure health condition by impedance-based technique using PZT patches, associated with longitudinal wave propagation. Health conditions of the square-structure controlled by bolt fastening condition is adjusted by torque wrench. In order to estimate the damage condition numerically, we suggest the evaluation method of impedance peak frequency shift

Decarburisation Effect on Hardened Strip Steel Fastening Components

Directory of Open Access Journals (Sweden)

Karli JAASON

2016-05-01

Full Text Available Heat treatment is widely used for high reliability fastening components such as buckles and brackets. The current study focuses on mass production of safety components which are fineblanked from sheet metal, austempered and chromium electroplated. Electroplating together with stamping defects may lead to unexpected brittle failure of the component. It is widely known that during austenitisation, decarburisation could avoid brittle failure and, therefore, slight decarburisation is recommended. There is little information how much mass production is influenced by decarburisation and where the limits are. The current study has two goals. The first one focuses on the extent of decarburisation effect on the part properties, and the second aims to find the optimum furnace setting for the product type used in the study. Also, it is necessary to choose a reliable decarburisation control method for austempered components. The effect on material grades was analyzed by using three steel alloys with carbon content of 0.37 wt.%, 0.47 wt.% and 0.62 wt.%. The specimens were austempered to hardness 45 – 51 HRC under endothermic protective atmosphere. To gain different decarburisation levels, two gas set-ups were used. Infrared gas analyzer was used to measure CO and CO2 content in the furnace gas. Three characteristics of the specimens were evaluated: hardness, rupture strength and brittleness. The depth of the decarburisation was determined by three different approaches according to standard EN ISO 3887. Based on the results, the spectrographic method is the most reliable for determining the depth of decarburisation. This study reveals that higher surface decarburisation has a positive effect on the ductility and no effect on the rupture strength of the component. The material with carbon content of 0.62 wt.% is the most sensitive to decarburisation. During mass production, the inaccuracy of hardness measuring raises which results in the inaccuracy of

From laboratory corrosion tests to a corrosion lifetime for wood fasteners : progress and challenges

Science.gov (United States)

Samuel L. Zelinka; Dominique Derome; Samuel V. Glass

2010-01-01

Determining a “corrosion-lifetime” for fasteners embedded in wood treated with recently adopted preservative systems depends upon successfully relating results of laboratory tests to in-service conditions. In contrast to laboratory tests where metal is embedded in wood at constant temperature and moisture content, the in-service temperature and moisture content of wood...

Administrative circular

CERN Multimedia

2003-01-01

• N° 21 - August 2003 Special leave This circular has been amended. Copies of this circular are available in the Divisional Secretariats. In addition, administrative and operational circulars, as well as the lists of those in force, are available for consultation on the Web at: http://cern.ch/hr-div/internal/admin_services/admincirc/listadmincirc.asp Human Resources Division Tel. 74128

Influence of panel fastening on the acoustic performance of light-weight building elements: Study by sound transmission and laser scanning vibrometry

Science.gov (United States)

Roozen, N. B.; Muellner, H.; Labelle, L.; Rychtáriková, M.; Glorieux, C.

2015-06-01

Structural details and workmanship can cause considerable differences in sound insulation properties of timber frame partitions. In this study, the influence of panel fastening is investigated experimentally by means of standardized sound reduction index measurements, supported by detailed scanning laser Doppler vibrometry. In particular the effect of the number of screws used to fasten the panels to the studs, and the tightness of the screws, is studied using seven different configurations of lightweight timber frame building elements. In the frequency range from 300 to 4000 Hz, differences in the weighted sound reduction index RW as large as 10 dB were measured, suggesting that the method of fastening can have a large impact on the acoustic performance of building elements. Using the measured vibrational responses of the element, its acoustic radiation efficiency was computed numerically by means of a Rayleigh integral. The increased radiation efficiency partly explains the reduced sound reduction index. Loosening the screws, or reducing the number of screws, lowers the radiation efficiency, and significantly increases the sound reduction index of the partition.

Comprehensive and Highly Accurate Measurements of Crane Runways, Profiles and Fastenings.

Science.gov (United States)

Dennig, Dirk; Bureick, Johannes; Link, Johannes; Diener, Dmitri; Hesse, Christian; Neumann, Ingo

2017-05-13

The process of surveying crane runways has been continually refined due to the competitive situation, modern surveying instruments, additional sensors, accessories and evaluation procedures. Guidelines, such as the International Organization for Standardization (ISO) 12488-1, define target values that must be determined by survey. For a crane runway these are for example the span, the position and height of the rails. The process has to be objective and reproducible. However, common processes of surveying crane runways do not meet these requirements sufficiently. The evaluation of the protocols, ideally by an expert, requires many years of experience. Additionally, the recording of crucial parameters, e.g., the wear of the rail, or the condition of the rail fastening and rail joints, is not regulated and for that reason are often not considered during the measurement. To solve this deficit the Advanced Rail Track Inspection System (ARTIS) was developed. ARTIS is used to measure the 3D position of crane rails, the cross-section of the crane rails, joints and, for the first time, the (crane-rail) fastenings. The system consists of a monitoring vehicle and an external tracking sensor. It makes kinematic observations with the tracking sensor from outside the rail run, e.g., the floor of an overhead crane runway, possible. In this paper we present stages of the development process of ARTIS, new target values, calibration of sensors and results of a test measurement.

Sound Scattering by a Flexible Plate Embedded on Free Surface

Directory of Open Access Journals (Sweden)

Eldad J. Avital

2012-01-01

Full Text Available Sound wave scattering by a flexible plate embedded on water surface is considered. Linear acoustics and plate elasticity are assumed. The aim is to assess the effect of the plate’s flexibility on sound scattering and the potential in using that flexibility for this purpose. A combined sound-structure solution is used, which is based on a Fourier transform of the sound field and a finite-difference numerical-solution of the plate’s dynamics. The solution is implemented for a circular plate subject to a perpendicular incoming monochromatic sound wave. A very good agreement is achieved with a finite-difference solution of the sound field. It is shown that the flexibility of the plate dampens its scattered sound wave regardless of the type of the plate’s edge support. A hole in the plate is shown to further scatter the sound wave to form maxima in the near sound field. It is suggested that applying an external oscillatory pressure on the plate can reduce significantly and even eliminate its scattered wave, thus making the plate close to acoustically invisible. A uniformly distributed external pressure is found capable of achieving that aim as long as the plate is free edged or is not highly acoustically noncompact.

Administrative Circulars Rev.

CERN Multimedia

2003-01-01

Administrative Circular N° 19 (Rev. 3) - April 2003 Subsistence indemnity - Other expenses necessarily incurred in the course of duty travelAdministrative Circular N° 25 (Rev. 2) - April 2003 Shift work - Special provisions for the Fire and Rescue Service - These circulars have been revised. Human Resources Division Tel. 74128Copies of these circulars are available in the Divisional Secretariats. In addition, administrative and operational circulars, as well as the lists of those in force, are available for consultation on the Web at: http://humanresources.web.cern.ch/humanresources/internal/admin_services/admincirc/listadmincirc.asp

Fuel assembly

International Nuclear Information System (INIS)

Fujibayashi, Toru.

1970-01-01

Herein disclosed is a fuel assembly in which a fuel rod bundle is easily detachable by rotating a fuel rod fastener rotatably mounted to the upper surface of an upper tie-plate supporting a fuel bundle therebelow. A locking portion at the leading end of each fuel rod protrudes through the upper tie-plate and is engaged with or separated from the tie-plate by the rotation of the fastener. The removal of a desired fuel rod can therefore be remotely accomplished without the necessity of handling pawls, locking washers and nuts. (Owens, K.J.)

78 FR 20888 - Foreign-Trade Zone (FTZ) 161-Sedgwick County, Kansas; Notification of Proposed Production...

Science.gov (United States)

2013-04-08

...- corrosion coatings; plastic tubes/washers/hoses/seals/sheets/tape/bags/ containers; bushings; funnels...; covers; gaskets; labels; fasteners; bolt extenders; springs; rings; bushings; flanges; hatches; supports...; filters; copper pipes/adapters/fasteners/reducers; aluminum plates/ flanges/covers; locks and locksets...

Transmission type Sc/Cr multilayers as a quarter-wave plate for 398.6 eV

International Nuclear Information System (INIS)

Kimura, H.; Hirono, T.; Tamenori, Y.; Saitoh, Y.; Salashchenko, N.N.; Ishikawa, T.

2004-01-01

Full text: Full polarization measurement using a phase shifter and a polarizer is needed to determine the degree of circular polarization. A quarter-wave plate, which is a phase shifter having retardation of 90 deg., is especially desired for accurate determination of the full polarization measurement for highly circularly polarized light. In the soft x-ray region, a self-standing multilayer with high reflectance can be used as a phase shifter having large retardation angle under transmission geometry. In this region, Mo/Si multilayer has been reported as a quarter-wave plate for photon energy of 97 eV. To perform the full polarization measurement in higher photon energy, we newly developed a quarter-wave plate by transmission type Sc/Cr multilayer. Polarization characteristics of the multilayer were measured by mean of rotating analyzer ellipsometry method using a linearly polarized SR of 398.6 eV. Figure 1 shows the retardation of the multilayer (Sc/Cr, d = 3.15 nm, 300 pairs). As is shown the phase shifter can be used as a quarter-wave plate at the incident angle of 59.7 deg. At this angle its transmittance for p-component and the ratio of those for p- and s-component were 0.4 % and 1.47, respectively

Damage of plates due to impact, dynamic pressure and explosive loads

Directory of Open Access Journals (Sweden)

Norman Jones

Full Text Available It is the purpose of this article to present design equations which can be used to predict the damage of ductile plating when subjected to mass impact, dynamic pressure or impulsive loadings. The external loadings are sufficiently severe to produce inelastic material behaviour and produce finite transverse displacement, or geometry change, effects. The damage is characterised as the final or permanent transverse displacement of a plate. The theoretical method predicts values for the maximum permanent transverse displacements which agree reasonably well with the corresponding experimental results generated on aluminium alloy circular, square and rectangular plates. Thus, the equations presented in this article are valuable for preliminary design purposes and for forensic studies, while the experimental data can be used for validating numerical schemes.

Operational Circulars

CERN Multimedia

2003-01-01

Operational Circular N° 4 - April 2003 Conditions for use by members of the CERN personnel of vehicles belonging to or rented by CERN - This circular has been drawn up. Operational Circular N° 5 - October 2000 Use of CERN computing facilities - Further details on the personal use of CERN computing facilities Operational Circular N° 5 and its Subsidiary Rules http://cern.ch/ComputingRules defines the rules for the use of CERN computing facilities. One of the basic principles governing such use is that it must come within the professional duties of the user concerned, as defined by the user's divisional hierarchy. However, personal use of the computing facilities is tolerated or allowed provided : a) It is in compliance with Operational Circular N° 5 and not detrimental to official duties, including those of other users; b) the frequency and duration is limited and there is a negligible use of CERN resources; c) it does not constitute a political, commercial and/or profit-making activity; d) it is not...

Information Circulars

International Nuclear Information System (INIS)

1969-01-01

Information circulars are published from time to time under the symbol INFCIRC/. . . . for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars which were of current interest on 15 January 1969 is given below, followed by an index to their subject matter. Other circulars can be traced by reference to earlier issues of the present document.

Information Circulars

Energy Technology Data Exchange (ETDEWEB)

NONE

1969-01-24

Information circulars are published from time to time under the symbol INFCIRC/. . . . for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars which were of current interest on 15 January 1969 is given below, followed by an index to their subject matter. Other circulars can be traced by reference to earlier issues of the present document.

Tempering of martensitic steel for fasteners : Effects of micro-alloying on microstructure and mechanical property evolution

NARCIS (Netherlands)

Öhlund, C.E.I.C.

2015-01-01

The research presented in this thesis aims to deepen our understanding of the effect of micro-alloying on the microstructure and mechanical property evolution during tempering of martensitic steel for fasteners. The ongoing trend of engine down-sizing has led to the need for stronger and more

Structural analysis of hatch cover plates on Fuels and Materials Examination Facility high bay mezzanine

International Nuclear Information System (INIS)

Dixson, G.E.

1997-01-01

In order to move the Idaho National Engineering Laboratory (INEL) Light Duty Utility Arm (LDUA) trailer into position for testing on the Fuels and Materials Examination Facility (FMEF) 42 ft level mezzanine one of the trailer's wheels will have to sit on a circular hatch cover fabricated from one-inch thick steel plate. The attached calculations verify that the hatch cover plate is strong enough to support the weight of the INEL LDUA trailer's wheel

Rapid Strengthening of Full-Sized Concrete Beams with Powder-Actuated fastening Systems and Fiber-Reinforced Polymer (FRP) Composite Materials

National Research Council Canada - National Science Library

Bank, Lawrence

2002-01-01

A research study was conducted to determine if the method of retrofitting reinforced concrete beams with powder-actuated fasteners and composite materials was applicable to full-scale flexural members...

A polymeric fastener can easily functionalize liposome surfaces with gadolinium for enhanced magnetic resonance imaging.

Science.gov (United States)

Smith, Cartney E; Shkumatov, Artem; Withers, Sarah G; Yang, Binxia; Glockner, James F; Misra, Sanjay; Roy, Edward J; Wong, Chun-Ho; Zimmerman, Steven C; Kong, Hyunjoon

2013-11-26

Common methods of loading magnetic resonance imaging (MRI) contrast agents into nanoparticles often suffer from challenges related to particle formation, complex chemical modification/purification steps, and reduced contrast efficiency. This study presents a simple, yet advanced process to address these issues by loading gadolinium, an MRI contrast agent, exclusively on a liposome surface using a polymeric fastener. The fastener, so named for its ability to physically link the two functional components together, consisted of chitosan substituted with diethylenetriaminepentaacetic acid (DTPA) to chelate gadolinium, as well as octadecyl chains to stabilize the modified chitosan on the liposome surface. The assembly strategy, mimicking the mechanisms by which viruses and proteins naturally anchor to a cell, provided greater T1 relaxivity than liposomes loaded with gadolinium in both the interior and outer leaflet. Gadolinium-coated liposomes were ultimately evaluated in vivo using murine ischemia models to highlight the diagnostic capability of the system. Taken together, this process decouples particle assembly and functionalization and, therefore, has considerable potential to enhance imaging quality while alleviating many of the difficulties associated with multifunctional particle fabrication.

Reactor cavity seal ring

International Nuclear Information System (INIS)

Hankinson, M.F.

1986-01-01

A hydrostatic seal is described for sealing an annular gap between two flat substantially horizontal coplanar surfaces comprising, in combination: a generally flat annular plate of a width sufficient to span a gap between two surfaces: compressible annular sealing means disposed on the bottom surface of the flat annular plate for sealingly engaging the two flat surfaces in response to a downward force exerted on the plate; and fastening means, distributed along the center line of the plate, for releasably fastening the plate in a position to span the gap to be sealed and exert a downward force on the plate, each fastening means including a pair of elongated members of a size to fit into the gap to be sealed, means for mounting the members on the bottom surface of the plate so that at least a portion of each member is radially moveable in a direction toward a respective one of the vertical side surfaces defining the gap to be sealed to engage same and so that the plate is moveable relative to the members in a downward direction in response to hydrostatic pressure applied to the upper surface of the plate when the members are engaging the vertical side surfaces of an annular gap, and an actuating means, mounted on the plate for movement therewith in response to hydrostatic pressure, for radially moving the members, the actuating means extending through a bore in the plate to the upper surface of the plate

Design for Circular Behaviour: Considering Users in a Circular Economy

Directory of Open Access Journals (Sweden)

Thomas Wastling

2018-05-01

Full Text Available In a linear economy, a product is manufactured and sold to a customer. Then, little concern is given to what the user actually does with it when they have it. However, in a circular economy where the aim is to circulate products at their highest level of value, the customer’s behaviour can become an important part of the system. Circular design strategies have tended to focus on the physical aspects of a product (e.g., disassembly, material selection, but the design of products and services can also have an influence on user behaviour and, to date, this aspect of circular design has not been fully explored. This project aims to define what key user behaviours are required for circular business models to work and to outline how design can enable these ‘circular behaviours’. This research project consists of a literature review, case study analysis and expert interviews with practitioners. A theoretical framework for designing products and services to encourage circular behaviour is developed. This work provides an initial step towards a better understanding of the user’s role in the transition to a circular economy as well as a preliminary model for how design for behaviour change strategies could be implemented in this context.

Parametric study of guided ultrasonic wave propagation in carbon-fiber composite plates

Science.gov (United States)

Ibrahim, N. A.; Kamarudin, M. A.; Jurimi, M. H. F. M.; Murat, B. I. S.

2018-03-01

The aim of this work is to study the guided ultrasonic wave (GUW) behaviour in composite plates using 3D Finite Element Analysis (FEA). Two types of composite models are chosen: plates with and without damage. The damage is modelled as a circular-shaped delamination inside the plate, representing one kind of low-velocity impact damage. Parameters such as excitation frequency, monitoring directivity, plate thickness, delamination size and shape were used to investigate the influence of these parameters on the GUW propagation and scattering behaviour. The models were constructed and coded in Matlab platform, while the simulations were performed in ABAQUS Explicit. From the results, the received signals have shown a strong dependency on the parameters. Significant scattering from the models with delamination were also observed, which indicates the possibility of using GUW for rapid non-destructive monitoring of composite panels and structures.

Temporary percutaneous T-fastener gastropexy and continuous decompressive gastrostomy in dogs with experimentally induced gastric dilatation.

Science.gov (United States)

Fox-Alvarez, W Alexander; Case, J Brad; Cooke, Kirsten L; Garcia-Pereira, Fernando L; Buckley, Gareth J; Monnet, Eric; Toskich, Beau B

2016-07-01

OBJECTIVE To evaluate a percutaneous, continuous gastric decompression technique for dogs involving a temporary T-fastener gastropexy and self-retaining decompression catheter. ANIMALS 6 healthy male large-breed dogs. PROCEDURES Dogs were anesthetized and positioned in dorsal recumbency with slight left-lateral obliquity. The gastric lumen was insufflated endoscopically until tympany was evident. Three T-fasteners were placed percutaneously into the gastric lumen via the right lateral aspect of the abdomen, caudal to the 13th rib and lateral to the rectus abdominis muscle. Through the center of the T-fasteners, a 5F locking pigtail catheter was inserted into the gastric lumen and attached to a device measuring gas outflow and intragastric pressure. The stomach was insufflated to 23 mm Hg, air was allowed to passively drain from the catheter until intraluminal pressure reached 5 mm Hg for 3 cycles, and the catheter was removed. Dogs were hospitalized and monitored for 72 hours. RESULTS Mean ± SD catheter placement time was 3.3 ± 0.5 minutes. Mean intervals from catheter placement to a ≥ 50% decrease in intragastric pressure and to ≤ 6 mm Hg were 2.1 ± 1.3 minutes and 8.4 ± 5.1 minutes, respectively. After catheter removal, no gas or fluid leakage at the catheter site was visible laparoscopically or endoscopically. All dogs were clinically normal 72 hours after surgery. CONCLUSIONS AND CLINICAL RELEVANCE The described technique was performed rapidly and provided continuous gastric decompression with no evidence of postoperative leakage in healthy dogs. Investigation is warranted to evaluate its effectiveness in dogs with gastric dilatation-volvulus.

Analysis of stress wave propagation in an elasto-viscoplastic plate

International Nuclear Information System (INIS)

Nakagawa, Noritoshi; Kawai, Ryoji; Urushi, Norio.

1986-01-01

Stress waves which propagate in the body are reflected at the boundary, and due to the interaction of the reflected stress waves, the focussing of stress waves will take place and a high stress level can be caused. The focussing of stress waves due to the reflection from the boundary may bring about fracture of the body, so that this is an important problem from a viewpoint of dynamic strength of structures. In this paper the process of stress wave focussing and the strain-rate dependence of constitutive equation in elastic and plastic regions are investigated. In the case where an in-plane step load uniformly acts on the straight edge of the plate with a semi-circular boundary, the propagation of stress waves in the plate was numerically analyzed by the finite element method, applying viscoelastic, elasto-plastic and elasto-viscoplastic constitutive equations. As the result, the process of focussing of stress waves due to reflection from the semi-circular boundary was observed and the difference in propagation behaviour of stress waves was discussed in materials represented by some kinds of constitutive equations. (author)

Exposure testing of fasteners in preservative treated wood : gravimetric corrosion rates and corrosion product analyses

Science.gov (United States)

Samuel L. Zelinka; Rebecca J. Sichel; Donald S. Stone

2010-01-01

Research was conducted to determine the corrosion rates of metals in preservative treated wood and also understand the mechanism of metal corrosion in treated wood. Steel and hot-dip galvanized steel fasteners were embedded in wood treated with one of six preservative treatments and exposed to 27oC at 100% relative humidity for 1 year. The...

Circular defects detection in welded joints using circular hough transform

International Nuclear Information System (INIS)

Hafizal Yazid; Mohd Harun; Shukri Mohd; Abdul Aziz Mohamed; Shaharudin Sayuti; Muhamad Daud

2007-01-01

Conventional radiography is one of the common non-destructive testing which employs manual image interpretation. The interpretation is very subjective and depends much on the inspector experience and working conditions. It is therefore useful to have pattern recognition system in order to assist human interpreter in evaluating the quality of the radiograph sample, especially radiographic image of welded joint. This paper describes a system to detect circular discontinuities that is present in the joints. The system utilizes together 2 different algorithms, which is separability filter to identify the best object candidate and Circular Hough Transform to detect the present of circular shape. The result of the experiment shows a promising output in recognition of circular discontinuities in a radiographic image. This is based on 81.82-100% of radiography film with successful circular detection by using template movement of 10 pixels. (author)

Stress and displacement analysis of a core plate, i.e. grid-perforated plate compound, modelled as an equivalent beam system

International Nuclear Information System (INIS)

Frank, R.; Engel, R.

1979-01-01

The core support plate is a very important component of the reactor pressure vessel internals. Therefore, an exact stress analysis is desired. This analysis will cause high computer costs with a detailed FEM-model because of the complexity of this compound system. In this paper, a method is suggested to solve the problem with a much cheaper beam element model. The main problem is to establish an equivalent beam system with nearly the same stiffness property as the perforated circular plate stiffened by a grid. Furthermore, the system must allow to determine the maximum stresses with sufficient accuracy. The calculation of the equivalent beam stiffness is based on the analysis of perforated plates by T. SLOT and W.J. O'DONNELL. This analysis method utilizes the concept of the equivalent solid plate. In this method, the perforated plate is replaced by a solid one which is geometrically similar to the perforated plate but has modified values of the elastic constants. The simple equivalent beam system of one half of the core support plate (symmetry) was loaded with a pressure difference and stresses and displacements were analysed. After that, these results were compared with the stress and displacement analysis of a part of the real structure. This substructure was discretized by three-dimensional 20-node brick-elements. The comparison of the results of the two models shows that the stresses and displacements, calculated with the simple beam model, are in good agreement with those of the real structure. (orig.)

An equivalent network representation of a clamped bimorph piezoelectric micromachined ultrasonic transducer with circular and annular electrodes using matrix manipulation techniques.

Science.gov (United States)

Sammoura, Firas; Smyth, Katherine; Kim, Sang-Gook

2013-09-01

An electric circuit model for a clamped circular bimorph piezoelectric micromachined ultrasonic transducer (pMUT) was developed for the first time. The pMUT consisted of two piezoelectric layers sandwiched between three thin electrodes. The top and bottom electrodes were separated into central and annular electrodes by a small gap. While the middle electrode was grounded, the central and annular electrodes were biased with two independent voltage sources. The strain mismatch between the piezoelectric layers caused the plate to vibrate and transmit a pressure wave, whereas the received echo generated electric charges resulting from plate deformation. The clamped pMUT plate was separated into a circular and an annular plate, and the respective electromechanical transformation matrices were derived. The force and velocity vectors were properly selected using Hamilton's principle and the necessary boundary conditions were invoked. The electromechanical transformation matrix for the clamped circular pMUT was deduced using simple matrix manipulation techniques. The pMUT performance under three biasing schemes was elaborated: 1) central electrode only, 2) central and annular electrodes with voltages of the same magnitude and polarity, and 3) central and annular electrodes with voltages of the same magnitude and opposite polarity. The circuit parameters of the pMUT were extracted for each biasing scheme, including the transformer ratio, the clamped electric impedance, and the open-circuit mechanical impedance. Each pMUT scheme was characterized under different acoustic loadings using the theoretically developed model, which was verified with finite element modeling (FEM) simulation. The electrode size was optimized to maximize the electromechanical transformer ratio. As such, the developed model could provide more insight into the design, optimization, and characterization of pMUTs and allow for performance comparison with their cMUT counterparts.

Vortex Airy beams directly generated via liquid crystal q-Airy-plates

Science.gov (United States)

Wei, Bing-Yan; Liu, Sheng; Chen, Peng; Qi, Shu-Xia; Zhang, Yi; Hu, Wei; Lu, Yan-Qing; Zhao, Jian-Lin

2018-03-01

Liquid crystal q-Airy-plates with director distributions integrated by q-plates and polarization Airy masks are proposed and demonstrated via the photoalignment technique. Single/dual vortex Airy beams of opposite topological charges and orthogonal circular polarizations are directly generated with polarization-controllable characteristic. The singular phase of the vortex part is verified by both astigmatic transformation and digital holography. The trajectory of vortex Airy beams is investigated, manifesting separate propagation dynamics of optical vortices and Airy beams. Meanwhile, Airy beams still keep their intrinsic transverse acceleration, self-healing, and nondiffraction features. This work provides a versatile candidate for generating high-quality vortex Airy beams.

Information Circulars

Energy Technology Data Exchange (ETDEWEB)

NONE

1973-09-10

Information circulars are published from time to time under the symbol INFCIRC/.. for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A subject index to the circulars is presented overleaf. It covers all those published in the last five years (that is, since the beginning of 1968 and ending with INFCIRC/192), as well as others which, for one reason or another, are still considered to be of current rather than merely historical interest. Such circulars can be traced by reference to the indexes that were included in earlier revisions of the present document.

Information Circulars

International Nuclear Information System (INIS)

1973-01-01

Information circulars are published from time to time under the symbol INFCIRC/.. for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A subject index to the circulars is presented overleaf. It covers all those published in the last five years (that is, since the beginning of 1968 and ending with INFCIRC/192), as well as others which, for one reason or another, are still considered to be of current rather than merely historical interest. Such circulars can be traced by reference to the indexes that were included in earlier revisions of the present document.

Oscillations of a spring-magnet system damped by a conductive plate

Science.gov (United States)

Ladera, C. L.; Donoso, G.

2013-09-01

We study the motion of a spring-magnet system that oscillates with very low frequencies above a circular horizontal non-magnetizable conductive plate. The magnet oscillations couple with the plate via the Foucault currents induced therein. We develop a simple theoretical model for this magneto-mechanical oscillator, a model that leads to the equation of a damped harmonic oscillator, whose weak attenuation constant depends upon the system parameters, e.g. the electrical conductivity of the constituent material of the plate and its thickness. We present a set of validating experiments, the results of which are predicted with good accuracy by our analytical model. Additional experiments can be performed with this oscillating system or its variants. This oscillator is simple and low-cost, easy to assemble, and can be used in experiments or project works in physics teaching laboratories at the undergraduate level.

Oscillations of a spring–magnet system damped by a conductive plate

International Nuclear Information System (INIS)

Ladera, C L; Donoso, G

2013-01-01

We study the motion of a spring–magnet system that oscillates with very low frequencies above a circular horizontal non-magnetizable conductive plate. The magnet oscillations couple with the plate via the Foucault currents induced therein. We develop a simple theoretical model for this magneto-mechanical oscillator, a model that leads to the equation of a damped harmonic oscillator, whose weak attenuation constant depends upon the system parameters, e.g. the electrical conductivity of the constituent material of the plate and its thickness. We present a set of validating experiments, the results of which are predicted with good accuracy by our analytical model. Additional experiments can be performed with this oscillating system or its variants. This oscillator is simple and low-cost, easy to assemble, and can be used in experiments or project works in physics teaching laboratories at the undergraduate level. (paper)

Corrosion fatigue of high strength fastener materials in seawater

Science.gov (United States)

Tipton, D. G.

1983-12-01

Environmental effects which significantly reduce the fatigue life of metals are discussed. Corrosion fatigue is a major concern in the engineering application of high strength fasteners in marine environments. The corrosion fatigue failure of an AISI 41L4O high strength steel blade to hub attachment bolt at the MOD-OA 200 kW wind turbine generator was investigated. The reduction of fatigue strength of AISI 41L4O in marine environments and to obtain similar corrosion fatigue data for candidate replacement materials was studied. The AISI 4140, PH 13-8Mo stainless steel, alloy 718 and alloy MP-35N were tested in axial fatigue at a frequency of 20 Hz in dry air and natural seawater. The fatigue data are fitted by regression equations to allow determination of fatigue strength for a given number of cycles to failure.

Information Circulars

International Nuclear Information System (INIS)

1965-01-01

Information circulars are published from time to time under the symbol INFCIRC/. for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars that were current on 31 December 1964 is given, followed by an index to their subject matter.

Information circulars

International Nuclear Information System (INIS)

1992-08-01

The document summarizes the Information Circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Members of the Agency. This revision contains INFCIRCs published up to mid-August 1992. A complete numerical lift of Information Circulars with their titles is reproduced in an Annex

Information Circulars

Energy Technology Data Exchange (ETDEWEB)

NONE

1965-01-18

Information circulars are published from time to time under the symbol INFCIRC/. for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars that were current on 31 December 1964 is given, followed by an index to their subject matter.

[Functional load distribution in cases of different types of removable dentures fastening].

Science.gov (United States)

Zhulev, E N; Klokov, A A

2007-01-01

Questions of studying of a biomechanics of system prosthesis - prosthetic region using of mathematical modelling are surveyed. The original way of definition of physical parameters of a mucosa of an edentulous alveolar process is offered. Modelling of a leaky adhering of prosthesis basis to a mucosa as free saddle situation shows, that a abutment teeth and an edentulous alveolar part of a jaw are in an optimum situation at sliding resilient fastening of a removable partial denture. Rigid bond in the given situation on the contrary promotes development of an overload of abutment teeth and their inclination distally.

Compact Low Frequency Radio Antenna

Science.gov (United States)

Punnoose, Ratish J.

2008-11-11

An antenna is disclosed that comprises a pair of conductive, orthogonal arches and a pair of conductive annular sector plates, wherein adjacent legs of each arch are fastened to one of the annular sector plates and the opposite adjacent pair of legs is fastened to the remaining annular sector plate. The entire antenna structure is spaced apart from a conductive ground plane by a thin dielectric medium. The antenna is driven by a feed conduit passing through the conductive ground plane and dielectric medium and attached to one of the annular sector plates, wherein the two orthogonal arched act as a pair of crossed dipole elements. This arrangement of elements provides a radiation pattern that is largely omni-directional above the horizon.

Manipulation robot system based on visual guidance for sealing blocking plate of steam generator

International Nuclear Information System (INIS)

Duan Xingguang; Wang Yonggui; Li Meng; Kong Xiangzhan; Liu Qingsong

2016-01-01

To reduce labor intensity and irradiation exposure time inside the steam generator during the maintenance period of the nuclear power plant, a blocking plate manipulation robot system, including manipulation robot and pneumatic control console, is developed as an automatic remote-control tool to help staff to complete sealing steam generator primary pipes. The manipulation robot for fastening/loosening bolts utilizes visual guidance for target position, and the recognition algorithm is exerted to extract the bolt center coordinate values from image captured by camera in the procedure. The control strategy based on the position and current feedback is proposed for single bolt operation and whole bolts automatic operation. Meanwhile, the virtual interactive interface and remote monitoring are designed to improve the operability and safety. Finally, the relative experiments have verified the work effectiveness and the future work would be discussed. (author)

Information circulars

International Nuclear Information System (INIS)

1997-02-01

The document summarizes the Information Circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Member States. This revision contains INFCIRCs published up to February 1997, grouped by field of activity. A complete list of information circulars in numerical order is given in an annex

Notched Strength of Woven Fabric Kenaf Composite Plates with Different Stacking Sequences and Hole Sizes

Directory of Open Access Journals (Sweden)

Hans Romayne Anders

2016-01-01

Full Text Available Advantages of using kenaf fibres over synthetic fibres in composites manufacturing are relatively cheap, less abrasive and hazardous during handling, and renewable materials. Current work investigates parametric effects on notched strength of woven fabric kenaf polymer composites plates with variation of lay-up types, notch sizes and plate thickness. Testing coupons are prepared using hand lay-up technique and circular notch were drilled prior to mechanical testing. Stress concentration at the notch edge promotes micro-damage event as tensile loading was applied leading to crack initiation and propagations across the plate width. It is suggested that woven fabric kenaf polymer composites are potentially used in low and medium load bearing applications.

Resonant frequency function of thickness-shear vibrations of rectangular crystal plates.

Science.gov (United States)

Wang, Ji; Yang, Lijun; Pan, Qiaoqiao; Chao, Min-Chiang; Du, Jianke

2011-05-01

The resonant frequencies of thickness-shear vibrations of quartz crystal plates in rectangular and circular shapes are always required in the design and manufacturing of quartz crystal resonators. As the size of quartz crystal resonators shrinks, for rectangular plates we must consider effects of both length and width for the precise calculation of resonant frequency. Starting from the three-dimensional equations of wave propagation in finite crystal plates and the general expression of vibration modes, we obtained the relations between frequency and wavenumbers. By satisfying the major boundary conditions of the dominant thickness-shear mode, three wavenumber solutions are obtained and the frequency equation is constructed. It is shown the resonant frequency of thickness-shear mode is a second-order polynomial of aspect ratios. This conforms to known results in the simplest form and is applicable to further analytical and experimental studies of the frequency equation of quartz crystal resonators.

Information circulars

International Nuclear Information System (INIS)

1994-08-01

Information circulars are published from time to time under the symbol INFCIRC/... for the purpose of bringing matters of general interest to the attention of all Members of the Agency. The present revision contains INFCIRCs published up to mid-August 1994. A complete numerical list of information circulars is reproduced with their titles in the Annex

Information circulars

International Nuclear Information System (INIS)

2002-05-01

Information circulars are published from time to time under the symbol INFCIRC/... for the purpose of bringing matters of general interest to the attention of all Members of the Agency. The present revision contains INFCIRCs published up to the end of April 2002. A complete numerical list of information circulars is reproduced with their titles in the Annex

Information circulars

International Nuclear Information System (INIS)

1999-06-01

The document summarizes the Information Circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Member States. This revision contains INFCIRCs published up to the end of May 1999, grouped by field of activity. A complete list of information circulars in numerical order is given in an annex

Information Circulars

International Nuclear Information System (INIS)

1966-01-01

Information circulars are published from time to time under the symbol INFCIRC/. . . . for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars that were current or on the press on 15 May 1966 is given, followed by an index to their subject matter.

Information Circulars

Energy Technology Data Exchange (ETDEWEB)

NONE

1966-06-10

Information circulars are published from time to time under the symbol INFCIRC/. . . . for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars that were current or on the press on 15 May 1966 is given, followed by an index to their subject matter.

Transposable elements and circular DNAs

KAUST Repository

Mourier, Tobias

2016-09-26

Circular DNAs are extra-chromosomal fragments that become circularized by genomic recombination events. We have recently shown that yeast LTR elements generate circular DNAs through recombination events between their flanking long terminal repeats (LTRs). Similarly, circular DNAs can be generated by recombination between LTRs residing at different genomic loci, in which case the circular DNA will contain the intervening sequence. In yeast, this can result in gene copy number variations when circles contain genes and origins of replication. Here, I speculate on the potential and implications of circular DNAs generated through recombination between human transposable elements.

Transposable elements and circular DNAs

KAUST Repository

Mourier, Tobias

2016-01-01

Circular DNAs are extra-chromosomal fragments that become circularized by genomic recombination events. We have recently shown that yeast LTR elements generate circular DNAs through recombination events between their flanking long terminal repeats (LTRs). Similarly, circular DNAs can be generated by recombination between LTRs residing at different genomic loci, in which case the circular DNA will contain the intervening sequence. In yeast, this can result in gene copy number variations when circles contain genes and origins of replication. Here, I speculate on the potential and implications of circular DNAs generated through recombination between human transposable elements.

A Squeeze-film Damping Model for the Circular Torsion Micro-resonators

Science.gov (United States)

Yang, Fan; Li, Pu

2017-07-01

In recent years, MEMS devices are widely used in many industries. The prediction of squeeze-film damping is very important for the research of high quality factor resonators. In the past, there have been many analytical models predicting the squeeze-film damping of the torsion micro-resonators. However, for the circular torsion micro-plate, the works over it is very rare. The only model presented by Xia et al[7] using the method of eigenfunction expansions. In this paper, The Bessel series solution is used to solve the Reynolds equation under the assumption of the incompressible gas of the gap, the pressure distribution of the gas between two micro-plates is obtained. Then the analytical expression for the damping constant of the device is derived. The result of the present model matches very well with the finite element method (FEM) solutions and the result of Xia’s model, so the present models’ accuracy is able to be validated.

Contribution of radon daughters plated-out in a cylindrical device by track-technique

Energy Technology Data Exchange (ETDEWEB)

Hafez, A.F. (Alexandria Univ. (Egypt). Dept. of Physics); Kotb, M.A. (Alexandria Univ. (Egypt). Biophysics Dept.); Toth-Szilagyi, M. (Magyar Tudomanyos Akademia, Debrecen (Hungary). Atommag Kutato Intezete)

1991-01-01

CR-39 plastic nuclear track detector is used to measure the fraction of alpha-particle tracks due to radon daughters activities plated-out on the internal walls of a cylindrical-shaped plastic can. Radium chloride solution is used as a radon source, the exposure time is ranged from 4 hours to 3 days. To assess the percentage of plate-out effect on CR-39 nuclear track detector, two different methods were used. In one experiment, a few circular parallel pairs of CR-39 sheets were hanged in the can device. In the other experiment, the estimation of the plate-out effect has been performed, after exposure to the radon source, by detecting tracks with a second unexposed sheet placed in close contact to the exposed wall and detectors. In the two methods, it was found that the chemically etched tracks related to plated-out activities contribute about 50% of the measured alpha-particles tracks. (orig.).

Experimental observations and modelling of thermal history within a steel plate during water jet impingement

International Nuclear Information System (INIS)

Liu, Z.D.; Fraser, D.; Samarasekera, I.V.; Lockhart, G.T.

2002-01-01

In order to investigate heat transfer of steel plates under a water jet impingement and to further simulate runout table operation in a hot strip mill, a full-scale pilot runout table facility was designed and constructed at the University of British Columbia (UBC). This paper describes the experimental details, data acquisition and data handling techniques for steel plates during water jet impingement by one circular water jet from an industrial header. Recorded visual observations at the impinging surface were obtained. The effects of cooling water temperature and impingement velocity on the heat transfer from a steel plate were studied. A two-dimensional finite element method-based transient inverse heat conduction model was developed. With the help of the model, heat fluxes and heat transfer coefficients along the impinging surface under various cooling conditions were calculated. The microstructural evolution of the steel plate was also investigated for the varying cooling conditions. Samples were obtained from each plate, polished, etched and then photographed. (author)

Korn inequalities for elastic junctions of massive bodies, thin plates, and rods

International Nuclear Information System (INIS)

Nazarov, S A

2008-01-01

Korn inequalities have been obtained for junctions of massive elastic bodies, thin plates, and rods in many different combinations. These inequalities are asymptotically sharp thanks to the introduction of various weight factors in the L 2 -norms of the displacements and their derivatives. Since thin bodies display different reactions to stretching and bending, such Korn inequalities are necessarily anisotropic. Junctions of elastic bodies with contrasting stiffness are allowed, but the constants in the inequalities obtained are independent of both the relative thickness h element of (0,1] and the relative rigidity μ element of (0,+∞). The norms corresponding to rigidly clamped elements of a structure are essentially different from the norms corresponding to hard-movable or movable elements that are not fastened directly, but only by means of neighbouring elements; therefore, an adequate structure of the weighted anisotropic norms is determined by the geometry of the whole junction. Each variant of Korn inequality is supplied with an example confirming the optimal choice of the weight factors

Information circulars

International Nuclear Information System (INIS)

1987-06-01

The document summarizes the information circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Members of the Agency. In the main body of the document only those documents which are regarded as likely to be of current interest are listed. A complete numerical list of information circulars with their titles is reproduced in the Annex

Analysis of interlocking performances on non-oriented electrical steels

Science.gov (United States)

Liu, Li-Hsiang; Liu, Lee-Cheng

2018-05-01

In order to reduce energy loss in motor, applications of high-efficiency non-oriented electrical steel sheets and optimal laminating process are both important elements. The motor core loss deterioration is influenced by a number of factors, such as flux distribution, stress and strain, space harmonics, temperature, and short circuits between lamination. In conventional clamping method, steel sheets are laminated via interlocking or welding in general manner. The measured energy loss by welding was much larger than that by interlocking. Therefore, interlocking is well known and usually employed with benefit of easy conducting. The protuberance shapes affected the fastening strength. Generally, the intensity of rectangular type is stronger than the circular counterparts. However, the circular interlocking has better magnetic characteristics. To clarify the method effectiveness, interlocking performances regarding fastened strength and magnetic deterioration by lamination were investigated. The key parameters of protuberance shape and forming depth were designed. Precisely manufacturing operation was applied to avoid interlocking failure. Magnetic properties largely influenced by clamping method are crucial to minimizing the magnetic deterioration during laminating procedure. Several experiments for various processing conditions were undertaken, and the quantification results showed the rectangular interlocking had better fastened strength but worsened iron loss comparing with the circular arrangement. To acquire the comprehensive mechanical and electrical identities for electrical steel lamination, deliberate producing conditions regarding minimizing the magnetic deterioration should be adopted prudently.

Electrochemical impedance spectroscopy (EIS) as a tool for measuring corrosion of polymer-coated fasteners used in treated wood

Science.gov (United States)

Samuel L. Zelinka; Lorraine Ortiz-Candelaria; Donald S. Stone; Douglas R. Rammer

2009-01-01

Currently, many of the polymer-coated fasteners on the market are designed for improved corrosion performance in treated wood; yet, there is no way to evaluate their corrosion performance. In this study, a common technique for measuring the corrosion performance of polymer-coated metals, electrochemical impedance spectroscopy (EIS), was used to evaluate commercial...

Flat plate approximation in the three-dimensional slamming; Heiban kinji ni yoru sanjigen suimen shogeki keisanho ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Toyama, Y. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

1996-12-31

A slamming load generated by interactive motions between a ship body and water face is an important load in ensuring safety of the ship. A flat plate approximation developed by Wagner is used as a two-dimensional slamming theory, but it has a drawback in handling edges of a flat plate. Therefore, an attempt was made to expand the two-dimensional Wagner`s theory to three dimensions. This paper first shows a method to calculate water face slamming of an arbitrary axisymmetric body by using circular plate approximation. The paper then proposes a method to calculate slamming pressure distribution and slamming force for the case when shape of the water contacting surface may be approximated by an elliptic shape. Expansion to the three dimensions made clear to some extent the characteristics of the three-dimensional slamming. In the case of two dimensions or a circular column for example, the water contacting area increases rapidly in the initial stage generating large slamming force. However, in the case of three dimensions, since the water contacting area expands longitudinally and laterally, the slamming force tends to increase gradually. Maximum slamming pressure was found proportional to square of moving velocity in a water contacting boundary in the case of three dimensions, and similar to stagnation pressure on a gliding plate. 12 refs., 17 figs., 1 tab.

Flat plate approximation in the three-dimensional slamming; Heiban kinji ni yoru sanjigen suimen shogeki keisanho ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Toyama, Y [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

1997-12-31

A slamming load generated by interactive motions between a ship body and water face is an important load in ensuring safety of the ship. A flat plate approximation developed by Wagner is used as a two-dimensional slamming theory, but it has a drawback in handling edges of a flat plate. Therefore, an attempt was made to expand the two-dimensional Wagner`s theory to three dimensions. This paper first shows a method to calculate water face slamming of an arbitrary axisymmetric body by using circular plate approximation. The paper then proposes a method to calculate slamming pressure distribution and slamming force for the case when shape of the water contacting surface may be approximated by an elliptic shape. Expansion to the three dimensions made clear to some extent the characteristics of the three-dimensional slamming. In the case of two dimensions or a circular column for example, the water contacting area increases rapidly in the initial stage generating large slamming force. However, in the case of three dimensions, since the water contacting area expands longitudinally and laterally, the slamming force tends to increase gradually. Maximum slamming pressure was found proportional to square of moving velocity in a water contacting boundary in the case of three dimensions, and similar to stagnation pressure on a gliding plate. 12 refs., 17 figs., 1 tab.

Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism.

Science.gov (United States)

Fan, Tingting; Grychtol, Patrik; Knut, Ronny; Hernández-García, Carlos; Hickstein, Daniel D; Zusin, Dmitriy; Gentry, Christian; Dollar, Franklin J; Mancuso, Christopher A; Hogle, Craig W; Kfir, Ofer; Legut, Dominik; Carva, Karel; Ellis, Jennifer L; Dorney, Kevin M; Chen, Cong; Shpyrko, Oleg G; Fullerton, Eric E; Cohen, Oren; Oppeneer, Peter M; Milošević, Dejan B; Becker, Andreas; Jaroń-Becker, Agnieszka A; Popmintchev, Tenio; Murnane, Margaret M; Kapteyn, Henry C

2015-11-17

We demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantum trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform.

Use of an Automated Suture Fastening Device in Minimally Invasive Aortic Valve Replacement.

Science.gov (United States)

Beute, Tyler J; Orem, Matthew D; Schiller, Timothy M; Goehler, Matthew; Parker, Jessica; Willekes, Charles L; Timek, Tomasz

2018-03-01

Minimally invasive aortic valve replacement (mAVR) is gaining clinical acceptance, however, it is associated with increased operative times due to limited surgical field and access. The Cor-Knot is an automated fastening device designed to facilitate suture fastening, but clinical data in mAVR are lacking. From May 2014 to February 2017, 92 patients underwent mAVR at our center with 39 valves secured with manually-tied (MT) sutures and 53 valves entirely secured with the Cor-Knot (CK). Pre-operative characteristics and 30-day outcomes data were extracted from our local Society of Thoracic Surgeons database and the electronic medical record. Survival data were obtained from the Michigan State Social Security Death Index. No significant difference in pre-operative characteristics were noted between the two groups. Aortic cross-clamp time (72±12 min vs 82±15 min, p=0.001) was significantly shorter with CK. There was no difference in post-operative mortality (0% vs 0%), stroke (0% vs 1.9%), atrial fibrillation (28% vs 33%), renal failure (0% vs 3.8%), or pacemaker implantation (5.1% vs 5.7%) between MT and CK. Valve function on post-operative echocardiography and 1-year patient survival were similar. In minimally invasive aortic valve replacement, the Cor-Knot device was associated with reduced aortic cross-clamp time while providing equivalent clinical outcomes. Larger studies are needed to confirm efficacy, safety, and cost-effectiveness of the Cor-Knot device in minimally invasive aortic valve surgery. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Transfer coefficients for plate fin and elliptical tube heat exchangers

International Nuclear Information System (INIS)

Saboya, S.M.; Saboya, F.E.M.

1981-01-01

In order to determine transfer coefficients for plate fin and elliptical tube exchangers, mass transfer experiments have been performed using the naphthalene sublimation technique. By means of the heat-mass transfer analogy, the results can be converted to heat transfer results. The transfer coefficients were compared with those for circular tube exchangers and the comparison revealed no major differences. This is a positive outcome, since the use of elliptical tubes may reduce substantially the pressure drop, without affecting the transfer characteristics.(Author) [pt

Simulation of a conductive shield plate for the focalization of transcranial magnetic stimulation in the rat.

Science.gov (United States)

Gasca, Fernando; Richter, Lars; Schweikard, Achim

2010-01-01

Transcranial Magnetic Stimulation (TMS) in the rat is a powerful tool for investigating brain function. However, the state-of-the-art experiments are considerably limited because the stimulation usually affects undesired anatomical structures. A simulation of a conductive shield plate placed between the coil stimulator and the rat brain during TMS is presented. The Finite Element (FE) method is used to obtain the 3D electric field distribution on a four-layer rat head model. The simulations show that the shield plate with a circular window can improve the focalization of stimulation, as quantitatively seen by computing the three-dimensional half power region (HPR). Focalization with the shield plate showed a clear compromise with the attenuation of the induced field. The results suggest that the shield plate can work as a helpful tool for conducting TMS rat experiments on specific targets.

Publication of administrative circular

CERN Multimedia

HR Department

2009-01-01

ADMINISTRATIVE CIRCULAR NO. 23 (REV. 2) – SPECIAL WORKING HOURS Administrative Circular No. 23 (Rev. 2) entitled "Special working hours", approved following discussion in the Standing Concertation Committee on 9 December 2008, will be available on the intranet site of the Human Resources Department as from 19 December 2008: http://cern.ch/hr-docs/admincirc/admincirc.asp It cancels and replaces Administrative Circular No. 23 (Rev. 1) entitled "Stand-by duty" of April 1988. A "Frequently Asked Questions" information document on special working hours will also be available on this site. Paper copies of this circular will shortly be available in Departmental Secretariats. Human Resources Department Tel. 78003

PUBLICATION OF ADMINISTRATIVE CIRCULAR

CERN Multimedia

HR Department

2008-01-01

ADMINISTRATIVE CIRCULAR NO. 23 (REV. 2) – SPECIAL WORKING HOURS Administrative Circular No. 23 (Rev. 2) entitled "Special working hours", approved following discussion in the Standing Concertation Committee meeting of 9 December 2008, will be available on the intranet site of the Human Resources Department as from 19 December 2008: http://cern.ch/hr-docs/admincirc/admincirc.asp It cancels and replaces Administrative Circular No. 23 (Rev. 1) entitled "Stand-by duty" of April 1988. A "Frequently Asked Questions" information document on special working hours will also be available on this site. Paper copies of this circular will shortly be available in departmental secretariats. Human Resources Department Tel. 78003

A numerical investigation of laminar forced convection in a solar collector with non-circular duct

Directory of Open Access Journals (Sweden)

Teleszewski Tomasz Janusz

2017-01-01

Full Text Available This paper presents a two-dimensional numerical study to investigate laminar flow in a flat plate solar collector with non-circular duct (regular polygonal, elliptical, and Cassini oval shape featuring forced convection with constant axial wall heat flux and constant peripheral wall temperature (H1 condition. Applying the velocity profile obtained for the duct laminar flow, the energy equation was solved exactly for the constant wall heat flux using the Boundary Element Method (BEM. Poiseuille and Nusselt numbers were obtained for flows having a different number of geometrical factors. The results are presented and discussed in the form of tables and graphs. The area goodness factor and volume goodness factor are calculated. The predicted correlations for Poiseuille and Nusselt numbers may be a very useful resource for the design and optimization of solar collectors with non-circular ducts.

A numerical investigation of laminar forced convection in a solar collector with non-circular duct

Science.gov (United States)

Janusz Teleszewski, Tomasz

2017-11-01

This paper presents a two-dimensional numerical study to investigate laminar flow in a flat plate solar collector with non-circular duct (regular polygonal, elliptical, and Cassini oval shape) featuring forced convection with constant axial wall heat flux and constant peripheral wall temperature (H1 condition). Applying the velocity profile obtained for the duct laminar flow, the energy equation was solved exactly for the constant wall heat flux using the Boundary Element Method (BEM). Poiseuille and Nusselt numbers were obtained for flows having a different number of geometrical factors. The results are presented and discussed in the form of tables and graphs. The area goodness factor and volume goodness factor are calculated. The predicted correlations for Poiseuille and Nusselt numbers may be a very useful resource for the design and optimization of solar collectors with non-circular ducts.

Comparison of measured and Monte Carlo calculated dose distributions from circular collimators for radiosurgical beams

International Nuclear Information System (INIS)

Esnaashari, K. N.; Allahverdi, M.; Gharaati, H.; Shahriari, M.

2007-01-01

Stereotactic radiosurgery is an important clinical tool for the treatment of small lesions in the brain, including benign conditions, malignant and localized metastatic tumors. A dosimetry study was performed for Elekta 'Synergy S' as a dedicated Stereotactic radiosurgery unit, capable of generating circular radiation fields with diameters of 1-5 cm at iso centre using the BEAM/EGS4 Monte Carlo code. Materials and Methods: The linear accelerator Elekta Synergy S equipped with a set of 5 circular collimators from 10 mm to 50 mm in diameter at iso centre distance was used. The cones were inserted in a base plate mounted on the collimator linac head. A PinPoint chamber and Wellhofer water tank chamber were selected for clinical dosimetry of 6 MV photon beams. The results of simulations using the Monte Carlo system BEAM/EGS4 to model the beam geometry were compared with dose measurements. Results: An excellent agreement was found between Monte Carlo calculated and measured percentage depth dose and lateral dose profiles which were performed in water phantom for circular cones with 1, 2, 3, 4 and 5 cm in diameter. The comparison between calculation and measurements showed up to 0.5 % or 1 m m difference for all field sizes. The penumbra (80-20%) results at 5 cm depth in water phantom and SSD=95 ranged from 1.5 to 2.1 mm for circular collimators with diameter 1 to 5 cm. Conclusion: This study showed that BEAMnrc code has been accurate in modeling Synergy S linear accelerator equipped with circular collimators

Nanowire surface fastener fabrication on flexible substrate

Science.gov (United States)

Toku, Yuhki; Uchida, Keita; Morita, Yasuyuki; Ju, Yang

2018-07-01

The market for wearable devices has increased considerably in recent years. In response to this demand, flexible electronic circuit technology has become more important. The conventional bonding technology in electronic assembly depends on high-temperature processes such as reflow soldering, which result in undesired thermal damages and residual stress at a bonding interface. In addition, it exhibits poor compatibility with bendable or stretchable device applications. Therefore, there is an urgent requirement to attach electronic parts on printed circuit boards with good mechanical and electrical properties at room temperature. Nanowire surface fasteners (NSFs) are candidates for resolving these problems. This paper describes the fabrication of an NSF on a flexible substrate, which can be used for room temperature conductive bonding. The template method is used for preparing high-density nanowire arrays. A Cu thin film is layered on the template as the flexible substrate. After etching the template, a Cu NSF is obtained on the Cu film substrate. In addition, the electrical and mechanical properties of the Cu NSF are studied under various fabrication conditions. The Cu NSF exhibits high shear adhesion strength (∼234 N cm‑2) and low contact resistivity (2.2 × 10‑4 Ω cm2).

Low velocity impact of 6082-T6 aluminum plates

Science.gov (United States)

Mocian, Oana Alexandra; Constantinescu, Dan Mihai; Sandu, Marin; Sorohan, Ştefan

2018-02-01

The low velocity domain covers vehicle impacts, ship collisions and even accidentally tool drops. Even though more and more research is needed into these fields, most of the papers concerning impact problems focus on impact at medium and high velocities. Understanding the behavior of structures subjected to low velocity impact is of major importance when referring to impact resistance and damage tolerance. The paper presents an experimental and numerical investigation on the low velocity behavior of 6082-T6 aluminum plates. Impact tests were performed using an Instron Ceast 9340 drop-weight testing machine. In the experimental procedure, square plates were mounted on a circular support, fixed with a pneumatic clamping system and impacted with a hemispherical steel projectile. Specimens were impacted at constant weight and different impact velocities. The effect of different impact energies was investigated. The impact event was then simulated using the nonlinear finite element code LS_DYNA in order to determine the effect of strain rate upon the mechanical behavior of the aluminum plates. Moreover, in order to capture the exact behavior of the material, a special attention has been given to the selection of the correct material model and its parameters, which, in large extent, depend on the observed behavior of the aluminum plate during the test and the actual response of the plate under simulation. The numerical predictions are compared with the experimental observations and the applicability of the numerical model for further researches is analyzed.

Development of a 3-D model for eddy current testing: application for fastened structures in aeronautics

International Nuclear Information System (INIS)

Paillard, S.

2007-12-01

One of the Eddy Current Testing issues in aeronautics is the inspection of fastened structures to detect flaws nearby rivets which can grow because of mechanical stress. EADS and the CEA LIST have started a collaborative work with the support of the Ile-de-France Region to develop a simulation tool of EC fastened structures testing, integrated to the CIVA platform, aimed at conceiving testing methods, optimizing and qualifying it. The volume integral method using the Green dyadics formalism has been chosen in order to get a fast resolution of Maxwell equations. A first milestone was to build a simulation model of multilayer structures testing, thanks to the use of the multilayer Green dyads. Because of the rivet volume, 60 times bigger than the one of a typical flaw, a large number of discretization cells are needed. Therefore an iterative method has been developed in order to numerically solve large calculation zones. Finally, the flaw response simulation mostly has to cope with a scale issue between the size of the rivet and the one of the flaw, the latter being much smaller in a direction than the former. The whole model has been experimentally validated and compared to other simulation models at the important development steps: multilayer configuration, iteration resolution, and flaw signature. (author)

Fast helicity switching of x-ray circular polarization at beamline P09 at PETRA III

Energy Technology Data Exchange (ETDEWEB)

Strempfer, J., E-mail: Joerg.Strempfer@desy.de; Mardegan, J. R. L.; Francoual, S.; Veiga, L. S. I.; Spitzbart, T.; Zink, H. [Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, 22603 Hamburg (Germany); Bouchenoire, L. [XMaS, ESRF, 6 rue Jules Horowitz, BP220, Grenoble 38043 (France); Department of Physics, University of Liverpool, Liverpool, L69 7ZE (United Kingdom)

2016-07-27

At the resonant scattering and diffraction beamline P09 at PETRA III/DESY, polarization manipulation in the X-ray energy range 3-13 keV is possible using wave-plates. Recently, fast flipping of circular polarization helicity using the Raspberry Pi controlled FPGA (PiLC) device developed at DESY and dedicated piezo-electric flippers has been commissioned. Functionality of the PiLC for XMCD and first XMCD measurements at the Fe K-and Dy-L{sub 3} absorption edges are presented.

Design of a Weighted-Rotor Energy Harvester Based on Dynamic Analysis and Optimization of Circular Halbach Array Magnetic Disk

Directory of Open Access Journals (Sweden)

Yu-Jen Wang

2015-03-01

Full Text Available This paper proposes the design of a weighted-rotor energy harvester (WREH in which the oscillation is caused by the periodic change of the tangential component of gravity, to harvest kinetic energy from a rotating wheel. When a WREH is designed with a suitable characteristic length, the rotor’s natural frequency changes according to the wheel rotation speed and the rotor oscillates at a wide angle and high angular velocity to generate a large amount of power. The magnetic disk is designed according to an optimized circular Halbach array. The optimized circular Halbach array magnetic disk provides the largest induced EMF for different sector-angle ratios for the same magnetic disk volume. This study examined the output voltage and power by considering the constant and accelerating plate-rotation speeds, respectively. This paper discusses the effects of the angular acceleration speed of a rotating wheel corresponding to the dynamic behaviors of a weighted rotor. The average output power is 399 to 535 microwatts at plate-rotation speeds from 300 to 500 rpm, enabling the WREH to be a suitable power source for a tire-pressure monitoring system.

Dependence of ion beam current on position of mobile plate tuner in multi-frequencies microwaves electron cyclotron resonance ion source

International Nuclear Information System (INIS)

Kurisu, Yosuke; Kiriyama, Ryutaro; Takenaka, Tomoya; Nozaki, Dai; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki

2012-01-01

We are constructing a tandem-type electron cyclotron resonance ion source (ECRIS). The first stage of this can supply 2.45 GHz and 11-13 GHz microwaves to plasma chamber individually and simultaneously. We optimize the beam current I FC by the mobile plate tuner. The I FC is affected by the position of the mobile plate tuner in the chamber as like a circular cavity resonator. We aim to clarify the relation between the I FC and the ion saturation current in the ECRIS against the position of the mobile plate tuner. We obtained the result that the variation of the plasma density contributes largely to the variation of the I FC when we change the position of the mobile plate tuner.

Thermo-aerodynamic efficiency of non-circular ducts with vortex enhancement of heat exchange in different types of compact heat exchangers

Science.gov (United States)

Vasilev, V. Ya; Nikiforova, S. A.

2018-03-01

Experimental studies of thermo-aerodynamic characteristics of non-circular ducts with discrete turbulators on walls and interrupted channels have confirmed the rational enhancement of convective heat transfer, in which the growth of heat transfer outstrips or equals the growth of aerodynamic losses. Determining the regularities of rational (energy-saving) enhancement of heat transfer and the proposed method for comparing the characteristics of smooth-channel (without enhancement) heat exchangers with effective analogs provide new results, confirming the high efficiency of vortex enhancement of convective heat transfer in non-circular ducts of plate-finned heat exchange surfaces. This allows creating heat exchangers with much smaller mass and volume for operation in energy-saving modes.

Circular states of atomic hydrogen

International Nuclear Information System (INIS)

Lutwak, R.; Holley, J.; Chang, P.P.; Paine, S.; Kleppner, D.; Ducas, T.

1997-01-01

We describe the creation of circular states of hydrogen by adiabatic transfer of a Rydberg state in crossed electric and magnetic fields, and also by adiabatic passage in a rotating microwave field. The latter method permits rapid switching between the two circular states of a given n manifold. The two methods are demonstrated experimentally, and results are presented of an analysis of the field ionization properties of the circular states. An application for the circular states is illustrated by millimeter-wave resonance in hydrogen of the n=29→n=30 transition. copyright 1997 The American Physical Society

Modeling guided wave excitation in plates with surface mounted piezoelectric elements: coupled physics and normal mode expansion

Science.gov (United States)

Ren, Baiyang; Lissenden, Cliff J.

2018-04-01

Guided waves have been extensively studied and widely used for structural health monitoring because of their large volumetric coverage and good sensitivity to defects. Effectively and preferentially exciting a desired wave mode having good sensitivity to a certain defect is of great practical importance. Piezoelectric discs and plates are the most common types of surface-mounted transducers for guided wave excitation and reception. Their geometry strongly influences the proportioning between excited modes as well as the total power of the excited modes. It is highly desirable to predominantly excite the selected mode while the total transduction power is maximized. In this work, a fully coupled multi-physics finite element analysis, which incorporates the driving circuit, the piezoelectric element and the wave guide, is combined with the normal mode expansion method to study both the mode tuning and total wave power. The excitation of circular crested waves in an aluminum plate with circular piezoelectric discs is numerically studied for different disc and adhesive thicknesses. Additionally, the excitation of plane waves in an aluminum plate, using a stripe piezoelectric element is studied both numerically and experimentally. It is difficult to achieve predominant single mode excitation as well as maximum power transmission simultaneously, especially for higher order modes. However, guidelines for designing the geometry of piezoelectric elements for optimal mode excitation are recommended.

Elasto-Plastic 3D Finite Element Contact Analysis of a Hole Containing a Circular Insert in a Fatigue Test Coupon

Science.gov (United States)

2015-08-01

Australian Air Force (RAAF) airframes. An aluminium - alloy fatigue test coupon (see Figure 1) has been designed and applied in support of the validation of...manufactured from aerospace aluminium alloy material (see Section 4 for further details). Unloaded close-fit fasteners of small diametric clearance were...Abaqus elasto–plastic input data requirements The aluminium and titanium alloys used in the coupon and fastener material display linear- elastic

Performance Characterization of Loctite (Registered Trademark) 242 and 271 Liquid Locking Compounds (LLCs) as a Secondary Locking Feature for International Space Station (ISS) Fasteners

Science.gov (United States)

Dube, Michael J.; Gamwell, Wayne R.

2011-01-01

Several International Space Station (ISS) hardware components use Loctite (and other polymer based liquid locking compounds (LLCs)) as a means of meeting the secondary (redundant) locking feature requirement for fasteners. The primary locking method is the fastener preload, with the application of the Loctite compound which when cured is intended to resist preload reduction. The reliability of these compounds has been questioned due to a number of failures during ground testing. The ISS Program Manager requested the NASA Engineering and Safety Center (NESC) to characterize and quantify sensitivities of Loctite being used as a secondary locking feature. The findings and recommendations provided in this investigation apply to the anaerobic LLCs Loctite 242 and 271. No other anaerobic LLCs were evaluated for this investigation. This document contains the findings and recommendations of the NESC investigation

Flow over a cylinder with a hinged-splitter plate

Science.gov (United States)

Shukla, S.; Govardhan, R. N.; Arakeri, J. H.

2009-05-01

Previous work on rigid splitter plates in the wake of a bluff body has shown that the primary vortex shedding can be suppressed for sufficiently long splitter plates. In the present work, we study the problem of a hinged-splitter plate in the wake of a circular cylinder. The splitter plate can rotate about the hinge at the base of the cylinder due to the unsteady fluid forces acting on it, and hence the communication between the two sides of the wake is not totally disrupted as in the rigid splitter plate case. In our study, we investigate this problem in the limit where the stiffness and internal damping associated with the hinge are negligible, and the mass ratio of the splitter plate is small. The experiments show that the splitter plate oscillations increase with Reynolds numbers at low values of Re, and are found to reach a saturation amplitude level at higher Re, Re>4000. This type of saturation amplitude level that appears to continue indefinitely with Re, appears to be related to the fact that there is no structural restoring force, and has been observed previously for transversely oscillating cylinders with no restoring force. In the present case, the saturation tip amplitude level can be up to 0.45D, where D is the cylinder diameter. For this hinged-rigid splitter plate case, it is found that the splitter plate length to cylinder diameter ratio (L/D) is crucial in determining the character and magnitude of the oscillations. For small splitter plate lengths (L/D⩽3.0), the oscillations appear to be nearly periodic with tip amplitudes of about 0.45D nearly independent of L/D. The nondimensional oscillation frequencies (fD/U) on the other hand are found to continuously vary with L/D from fD/U≈0.2 at L/D=1 to fD/U≈0.1 at L/D=3. As the splitter plate length is further increased beyond L/D⩾4.0, the character of the splitter plate oscillations suddenly changes. The oscillations become aperiodic with much smaller amplitudes. In this long splitter plate

Solid Angle Computations for a Circular Radiator and a Circular Detector

Energy Technology Data Exchange (ETDEWEB)

Konijn, J; Tollander, B

1963-02-15

The problem of particle detection, when using an isotropic neutron point source at different distances from a circular target or a radioactive source as seen by a circular detector, e. g. a solid state counter, is dealt with. Tables are given for different distances of the source when the reaction at the target has an isotropic or a cosine angular distribution in the laboratory system.

Optimization of a functionally graded circular plate with inner rigid thin obstacles. I. Continuous problems

Czech Academy of Sciences Publication Activity Database

Hlaváček, Ivan; Lovíšek, J.

2011-01-01

Roč. 91, č. 9 (2011), s. 711-723 ISSN 0044-2267 R&D Projects: GA AV ČR(CZ) IAA100190803 Institutional research plan: CEZ:AV0Z10190503 Keywords : functionally graded plate * optimal design Subject RIV: BA - General Mathematics Impact factor: 0.863, year: 2011 http://onlinelibrary.wiley.com/doi/10.1002/zamm.201000119/abstract

Antennas on circular cylinders

DEFF Research Database (Denmark)

Knudsen, H. L.

1959-01-01

On the basis of the results obtained by Silver and Saunders [4] for the field radiated from an arbitrary slot in a perfectly conducting circular cylinder, expressions have been derived for the field radiated by a narrow helical slot, with an arbitrary aperture field distribution, in a circular...... antenna in a circular cylinder. By a procedure similar to the one used by Silver and Saunders, expressions have been derived for the field radiated from an arbitrary surface current distribution on a cylinder surface coaxial with a perfectly conducting cylinder. The cases where the space between the two...

Requalification analysis of a circular composite slab for seismic load

International Nuclear Information System (INIS)

Srinivasan, M.G.; Kot, C.A.

1993-01-01

The circular roof slab of an existing facility was analyzed to requalify the structure for supporting a significant seismic load that it was not originally designed for. The slab has a clear span of 66 ft and consists of a 48 in. thick reinforced concrete member and a steel liner plate. Besides a number of smaller penetrations, the slab contains two significant cutouts. The dominant load for the slab came from seismic excitation. It was characterized by a response spectrum with a peak spectral acceleration of 0.72 g in the vertical direction. The first part of the analysis showed that the nature of attachment between the liner plate and the reinforced concrete (RC) slab would justify assuming composite action between the two. A finite clement analysis, with the ANSYS code, was made to investigate the region surrounding the openings. As the reinforcement in the slab was quite inhomogeneous, it was necessary to determine the stresses in other areas of the slab also. These were obtained with closed form expressions. Finally it is shown that the strength design provisions of the Code Requirements for Nuclear Safety Related Concrete Structures were met by the reinforced concrete slab and the allowable stress provisions of the American National Standard for safety related steel structures in nuclear facilities were met by the liner plate. The composite action between the RC slab and the liner plate provides for the additional strength required to support the enhanced seismic load. The issues that complicated the analysis of this nontypical structure, i.e., composite action and nonlinear stiffness of RC sections, are discussed. It was possible to circumvent the difficulties by making conservative and simplifying assumptions. If design codes incorporate guidelines on practical methods for dynamic analysis of RC structures, some of the unneeded conservatism could be eliminated in future designs

Energy Neutral Wireless Bolt for Safety Critical Fastening.

Science.gov (United States)

Seyoum, Biruk B; Rossi, Maurizio; Brunelli, Davide

2017-09-26

Thermoelectric generators (TEGs) are now capable of powering the abundant low power electronics from very small (just a few degrees Celsius) temperature gradients. This factor along with the continuously lowering cost and size of TEGs, has contributed to the growing number of miniaturized battery-free sensor modules powered by TEGs. In this article, we present the design of an ambient-powered wireless bolt for high-end electro-mechanical systems. The bolt is equipped with a temperature sensor and a low power RF chip powered from a TEG. A DC-DC converter interfacing the TEG with the RF chip is used to step-up the low TEG voltage. The work includes the characterizations of different TEGs and DC-DC converters to determine the optimal design based on the amount of power that can be generated from a TEG under different loads and at temperature gradients typical of industrial environments. A prototype system was implemented and the power consumption of this system under different conditions was also measured. Results demonstrate that the power generated by the TEG at very low temperature gradients is sufficient to guarantee continuous wireless monitoring of the critical fasteners in critical systems such as avionics, motorsport and aerospace.

Energy Neutral Wireless Bolt for Safety Critical Fastening

Directory of Open Access Journals (Sweden)

Biruk B. Seyoum

2017-09-01

Full Text Available Thermoelectric generators (TEGs are now capable of powering the abundant low power electronics from very small (just a few degrees Celsius temperature gradients. This factor along with the continuously lowering cost and size of TEGs, has contributed to the growing number of miniaturized battery-free sensor modules powered by TEGs. In this article, we present the design of an ambient-powered wireless bolt for high-end electro-mechanical systems. The bolt is equipped with a temperature sensor and a low power RF chip powered from a TEG. A DC-DC converter interfacing the TEG with the RF chip is used to step-up the low TEG voltage. The work includes the characterizations of different TEGs and DC-DC converters to determine the optimal design based on the amount of power that can be generated from a TEG under different loads and at temperature gradients typical of industrial environments. A prototype system was implemented and the power consumption of this system under different conditions was also measured. Results demonstrate that the power generated by the TEG at very low temperature gradients is sufficient to guarantee continuous wireless monitoring of the critical fasteners in critical systems such as avionics, motorsport and aerospace.

Towards Circular Business Models

DEFF Research Database (Denmark)

Guldmann, Eva; Remmen, Arne

The present report concerns the practical process of developing initiatives based on the circular economy in eight Danish companies. The report outlines how the process of integrating the circular economy was approached in each of the participating companies during 2014 and 2015 and what came out...

Circularity and Lambda Abstraction

DEFF Research Database (Denmark)

Danvy, Olivier; Thiemann, Peter; Zerny, Ian

2013-01-01

unknowns from what is done to them, which we lambda-abstract with functions. The circular unknowns then become dead variables, which we eliminate. The result is a strict circu- lar program a la Pettorossi. This transformation is reversible: given a strict circular program a la Pettorossi, we introduce...

The generalized circular model

NARCIS (Netherlands)

Webers, H.M.

1995-01-01

In this paper we present a generalization of the circular model. In this model there are two concentric circular markets, which enables us to study two types of markets simultaneously. There are switching costs involved for moving from one circle to the other circle, which can also be thought of as

Best Practice Examples of Circular Business Models

DEFF Research Database (Denmark)

Guldmann, Eva

Best practice examples of circular business models are presented in this report. The purpose is to inform and inspire interested readers, in particular companies that aspire to examine the potentials of the circular economy. Circular business models in two different sectors are examined, namely...... the textile and clothing sector as well as the durable goods sector. In order to appreciate the notion of circular business models, the basics of the circular economy are outlined along with three frameworks for categorizing the various types of circular business models. The frameworks take point of departure...... in resource loops, value bases and business model archetypes respectively, and they are applied for analysing and organizing the business models that are presented throughout the report. The investigations in the report show that circular business models are relevant to businesses because they hold...

The Transition from Thick to Thin Plate Wake Physics: Whither Vortex Shedding?

Science.gov (United States)

Rai, Man Mohan

2016-01-01

The near and very near wake of a flat plate with a circular trailing edge is investigated with data from direct numerical simulations. Computations were performed for six different combinations of the Reynolds numbers based on plate thickness (D) and boundary layer momentum thickness upstream of the trailing edge (theta). Unlike the case of the cylinder, these Reynolds numbers are independent parameters for the flat plate. The separating boundary layers are turbulent in all the cases investigated. One objective of the study is to understand the changes in the wake vortex shedding process as the plate thickness is reduced (increasing theta/D). The value of D varies by a factor of 16 and that of theta by approximately 5 in the computations. Vortex shedding is vigorous in the low theta/D cases with a substantial decrease in shedding intensity in the large theta/D cases. Other shedding characteristics are also significantly altered with increasing theta/D. A visualization of the shedding process in the different cases is provided and discussed. The basic shedding mechanism is explored in depth. The effect of changing theta/D on the time-averaged, near-wake velocity statistics is also discussed. A functional relationship between the shedding frequency and the Reynolds numbers mentioned above is obtained.

Circular arc structures

KAUST Repository

Bo, Pengbo

2011-07-01

The most important guiding principle in computational methods for freeform architecture is the balance between cost efficiency on the one hand, and adherence to the design intent on the other. Key issues are the simplicity of supporting and connecting elements as well as repetition of costly parts. This paper proposes so-called circular arc structures as a means to faithfully realize freeform designs without giving up smooth appearance. In contrast to non-smooth meshes with straight edges where geometric complexity is concentrated in the nodes, we stay with smooth surfaces and rather distribute complexity in a uniform way by allowing edges in the shape of circular arcs. We are able to achieve the simplest possible shape of nodes without interfering with known panel optimization algorithms. We study remarkable special cases of circular arc structures which possess simple supporting elements or repetitive edges, we present the first global approximation method for principal patches, and we show an extension to volumetric structures for truly threedimensional designs. © 2011 ACM.

A Conceptual Framework for Circular Design

Directory of Open Access Journals (Sweden)

Mariale Moreno

2016-09-01

Full Text Available Design has been recognised in the literature as a catalyst to move away from the traditional model of take-make-dispose to achieve a more restorative, regenerative and circular economy. As such, for a circular economy to thrive, products need to be designed for closed loops, as well as be adapted to generate revenues. This should not only be at the point of purchase, but also during use, and be supported by low-cost return chains and reprocessing structures, as well as effective policy and regulation. To date, most academic and grey literature on the circular economy has focused primarily on the development of new business models, with some of the latter studies addressing design strategies for a circular economy, specifically in the area of resource cycles and design for product life extension. However, these studies primarily consider a limited spectrum of the technical and biological cycles where materials are recovered and restored and nutrients (e.g., materials, energy, water are regenerated. This provides little guidance or clarity for designers wishing to design for new circular business models in practice. As such, this paper aims to address this gap by systematically analysing previous literature on Design for Sustainability (DfX (e.g., design for resource conservation, design for slowing resource loops and whole systems design and links these approaches to the current literature on circular business models. A conceptual framework is developed for circular economy design strategies. From this conceptual framework, recommendations are made to enable designers to fully consider the holistic implications for design within a circular economy.

Asymptotic theory of circular polarization memory.

Science.gov (United States)

Dark, Julia P; Kim, Arnold D

2017-09-01

We establish a quantitative theory of circular polarization memory, which is the unexpected persistence of the incident circular polarization state in a strongly scattering medium. Using an asymptotic analysis of the three-dimensional vector radiative transfer equation (VRTE) in the limit of strong scattering, we find that circular polarization memory must occur in a boundary layer near the portion of the boundary on which polarized light is incident. The boundary layer solution satisfies a one-dimensional conservative scattering VRTE. Through a spectral analysis of this boundary layer problem, we introduce the dominant mode, which is the slowest-decaying mode in the boundary layer. To observe circular polarization memory for a particular set of optical parameters, we find that this dominant mode must pass three tests: (1) this dominant mode is given by the largest, discrete eigenvalue of a reduced problem that corresponds to Fourier mode k=0 in the azimuthal angle, and depends only on Stokes parameters U and V; (2) the polarization state of this dominant mode is largely circular polarized so that |V|≫|U|; and (3) the circular polarization of this dominant mode is maintained for all directions so that V is sign-definite. By applying these three tests to numerical calculations for monodisperse distributions of Mie scatterers, we determine the values of the size and relative refractive index when circular polarization memory occurs. In addition, we identify a reduced, scalar-like problem that provides an accurate approximation for the dominant mode when circular polarization memory occurs.

Fastener locking device for attaching guide thimble to fuel assembly bottom nozzle

International Nuclear Information System (INIS)

Widener, W.H.

1987-01-01

This patent describes a nuclear reactor fuel assembly including an end nozzle and at least one longitudinally-extending guide thimble projecting away from the end nozzle. The end nozzle has at least one passageway defined therethrough and a ledge defined within the passageway so as to face away from the guide thimble and divide the passageway into a first portion extending from the ledge toward the guide thimble. A second portion extends from the ledge away from the guide thimble. The second passageway portion has a larger cross-sectional size than the first passageway portion, the end nozzle also having recess means defined thereon in the second portion of the passageway. The guide thimble has an end disposed adjacent to the first portion of the passageway with threaded means defined thereon and a fastener locking device

Effect of elliptic or circular holes on the stress distribution in plates of wood or plywood considered as orthotropic materials

Science.gov (United States)

C. B. Smith

1944-01-01

This is a mathematical analysis of the stress distribution existing near a hole in a wood or plywood plate subjected to tension, as, for example, near holes in the tension flanges of wood box beams. It is assumed that the strains are small and remain within the proportional limit. In this analysis a large, rectangular, orthotropic plate with a small elliptic hole at...

Rotating flux-focusing eddy current probe for flaw detection

Science.gov (United States)

Wincheski, Russell A. (Inventor); Fulton, James P. (Inventor); Nath, Shridhar C. (Inventor); Simpson, John W. (Inventor); Namkung, Min (Inventor)

1997-01-01

A flux-focusing electromagnetic sensor which uses a ferromagnetic flux-focusing lens simplifies inspections and increases detectability of fatigue cracks about circular fasteners and other circular inhomogeneities in high conductivity material. The unique feature of the device is the ferrous shield isolating a high-turn pick-up coil from an excitation coil, The use of the magnetic shield is shown to produce a null voltage output across the receiving coil in the presence of an unflawed sample. A redistribution of the current flow in the sample caused by the presence of flaws, however, eliminates the shielding condition and a large output voltage is produced, yielding a clear unambiguous flaw signal. By rotating the probe in a path around a circular fastener such as a rivet while maintaining a constant distance between the probe and the center of a rivet, the signal due to current flow about the rivet can be held constant. Any further changes in the current distribution, such as due to a fatigue crack at the rivet joint, can be detected as an increase in the output voltage above that due to the flow about the rivet head.

Flux-focusing eddy current probe and rotating probe method for flaw detection

Science.gov (United States)

Wincheski, Buzz A.; Fulton, James P.; Nath, Shridhar C.; Simpson, John W.; Namkung, Min

1994-11-01

A flux-focusing electromagnetic sensor which uses a ferromagnetic flux-focusing lens simplifies inspections and increases detectability of fatigue cracks about circular fasteners and other circular inhomogeneities in high conductivity material. The unique feature of the device is the ferrous shield isolating a high-turn pick-up coil from an excitation coil. The use of the magnetic shield is shown to produce a null voltage output across the receiving coil in the presence of an unflawed sample. A redistribution of the current flow in the sample caused by the presence of flaws, however, eliminates the shielding condition and a large output voltage is produced, yielding a clear unambiguous flaw signal. By rotating the probe in a path around a circular fastener such as a rivet while maintaining a constant distance between the probe and the center of a rivet, the signal due to current flow about the rivet can be held constant. Any further changes in the current distribution, such as due to a fatigue crack at the rivet joint, can be detected as an increase in the output voltage above that due to the flow about the rivet head.

How to Assess Product Performance in the Circular Economy? Proposed Requirements for the Design of a Circularity Measurement Framework

OpenAIRE

Saidani , Michael; YANNOU , Bernard; Leroy , Yann; Cluzel , François

2017-01-01

International audience; Assessing product circularity performance is not straightforward. Meanwhile, it gains increasingly importance for businesses and industrial practitioners who are willing to effectively take benefits from circular economy promises. Thus, providing methods and tools to evaluate then enhance product performance—in the light of circular economy—becomes a significant but still barely addressed topic. Following a joint agreement on the need to measure product circularity per...

Circularly polarized light to study linear magneto-optics for ferrofluids: θ-scan technique

Science.gov (United States)

Meng, Xiangshen; Huang, Yan; He, Zhenghong; Lin, Yueqiang; Liu, Xiaodong; Li, Decai; Li, Jian; Qiu, Xiaoyan

2018-06-01

Circularly polarized light can be divided into two vertically linearly polarized light beams with  ±π/2 phase differences. In the presence of an external magnetic field, when circularly polarized light travels through a ferrofluid film, whose thickness is no more than that of λ/4 plate, magneto-optical, magnetic birefringence and dichroism effects cause the transmitted light to behave as elliptically polarized light. Using angular scan by a continuously rotating polarizer as analyzer, the angular (θ) distribution curve of relative intensity (T) corresponding to elliptically polarized light can be measured. From the T  ‑  θ curve having ellipsometry, the parameters such as the ratio of short to long axis, and angular orientation of the long axis to the vertical field direction can be obtained. Thus, magnetic birefringence and dichroism can be probed simultaneously by measuring magneto-optical, positive or negative birefringence and dichroism features from the transmission mode. The proposed method is called θ-scan technique, and can accurately determine sample stability, magnetic field direction, and cancel intrinsic light source ellipticity. This study may be helpful to further research done to ferrofluids and other similar colloidal samples with anisotropic optics.

Modeling particulate removal in plate-plate and wire-plate electrostatic precipitators

Directory of Open Access Journals (Sweden)

S Ramechecandane

2016-09-01

Full Text Available The present study is concerned with the modeling of electrically charged particles in a model plate-plate and a single wire-plate electrostatic precipitator (ESP. The particle concentration distributions for both a plate-plate and a wire-plate ESP are calculated using a modified drift flux model. Numerical investigations are performed using the modified drift flux model for particle number concentration, in addition to the RNG k - ε model for the mean turbulent flow field and the Poisson equation for the electric field. The proposed model and the outlined methodology for coupling the flow field, electric field, charging kinetics and particle concentration is applied to two model precipitators that are truly representative of a wide class of commercialized ESPs. The present investigation is quite different from the earlier studies as it does not make assumptions like a homogeneous electric field or an infinite turbulent diffusivity. The electric field calculated is a strong function of position and controls the migration velocity of particles. Hence, the proposed model can be implemented in a flow solver to obtain a full-fledged solution for any kind of ESP with no limitations on the particle number concentration, as encountered in a Lagrangian approach. The effect of turbulent diffusivity on particle number concentration in a plate-plate ESP is investigated in detail and the results obtained are compared with available experimental data. Similarly, the effect of particle size/diameter and applied electric potential on the accumulative collection performance in the case of a wire-plate ESP is studied and the results obtained are compared with available numerical data. The numerical results obtained using the modified drift flux model for both the plate-plate and wire-plate ESP are in close agreement with available experimental and numerical data.

Computational simulations of hydrogen circular migration in protonated acetylene induced by circularly polarized light

Energy Technology Data Exchange (ETDEWEB)

Shi, Xuetao; Li, Wen; Schlegel, H. Bernhard, E-mail: hbs@chem.wayne.edu [Department of Chemistry, Wayne State University, Detroit, Michigan 48202 (United States)

2016-08-28

The hydrogens in protonated acetylene are very mobile and can easily migrate around the C{sub 2} core by moving between classical and non-classical structures of the cation. The lowest energy structure is the T-shaped, non-classical cation with a hydrogen bridging the two carbons. Conversion to the classical H{sub 2}CCH{sup +} ion requires only 4 kcal/mol. The effect of circularly polarized light on the migration of hydrogens in oriented C{sub 2}H{sub 3}{sup +} has been simulated by Born-Oppenheimer molecular dynamics. Classical trajectory calculations were carried out with the M062X/6-311+G(3df,2pd) level of theory using linearly and circularly polarized 32 cycle 7 μm cosine squared pulses with peak intensity of 5.6 × 10{sup 13} W/cm{sup 2} and 3.15 × 10{sup 13} W/cm{sup 2}, respectively. These linearly and circularly polarized pulses transfer similar amounts of energy and total angular momentum to C{sub 2}H{sub 3}{sup +}. The average angular momentum vectors of the three hydrogens show opposite directions of rotation for right and left circularly polarized light, but no directional preference for linearly polarized light. This difference results in an appreciable amount of angular displacement of the three hydrogens relative to the C{sub 2} core for circularly polarized light, but only an insignificant amount for linearly polarized light. Over the course of the simulation with circularly polarized light, this corresponds to a propeller-like motion of the three hydrogens around the C{sub 2} core of protonated acetylene.

Circular Updates

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Circular Updates are periodic sequentially numbered instructions to debriefing staff and observers informing them of changes or additions to scientific and specimen...

Oscillations of oblate drop between heterogeneous plates under uniform electric field

Science.gov (United States)

Kashina, M. A.; Alabuzhev, A. A.

2018-01-01

The forced oscillations of the incompressible fluid drop under the action of the uniform electric field are considered. In equilibrium, the drop has the form of a circular cylinder bounded axially by the parallel solid planes; the contact angle is right. An incompressible fluid of different density surrounds the drop. The external electric field acts as an external force that causes motion of the contact line. In order to describe this contact line motion, the modified Hocking boundary condition is applied: the velocity of the contact line is proportional to the deviation of the contact angle and the speed of the fast relaxation processes, whose frequency is proportional to twice the frequency of the electric field. The case of heterogeneous plates is investigated. We assume that the Hocking parameter depends on the polar angle in this case. The function describing the change in the coefficient of the interaction between the plate and the fluid (the contact line) is expanded in a series of the Laplace operator eigenfunctions.

Circular RNAs as Promising Biomarkers: A mini-review

Directory of Open Access Journals (Sweden)

Nadiah Abu

2016-08-01

Full Text Available The interest in circular RNAs has resurfaced in the past few years. What was considered as junk for nearly two decades is now one of the most interesting molecules. Circular RNAs are non-coding RNAs that are formed by back-splicing events and have covalently closed loops with no poly-adenylated tails. The regulation of circular RNAs is distinctive and they are selectively abundant in different types of tissues. Based on the current knowledge of circular RNAs, these molecules have the potential to be the next big thing especially as biomarkers for different diseases. This mini-review attempts to concisely look at the biology of circular RNAs, the putative functional activities, the prevalence of circular RNAs, and the possible role of circular RNA as biomarkers for diagnosis or measuring drug response.

Mikrospiegelanordnung

OpenAIRE

Hofmann, Ulrich; Senger, Frank

2015-01-01

The invention relates to a micro-mirror assembly, comprising a mirror plate (2) fastened to a substrate by means of spring elements, wherein a drive unit (9, 10) is associated with the mirror plate, which drive unit is designed to drive the mirror plate about at least one axis such that the mirror plate oscillates about said axis. The spring elements are designed as a plurality of spring ring frames (3) that surround the mirror plate (2) substantially in the mirror plate plane of the mirror p...

Broadband Circularly Polarized Slot Antenna Loaded by a Multiple-Circular-Sector Patch.

Science.gov (United States)

Trinh-Van, Son; Yang, Youngoo; Lee, Kang-Yoon; Hwang, Keum Cheol

2018-05-15

In this paper, a microstrip-fed broadband circularly polarized (CP) slot antenna is presented. CP operation can be attained simply by embedding an S-shaped strip. By loading with a multiple-circular-sector patch, which consists of 12 circular-sector patches with identical central angles of 30° and different radii, the 3 dB axial ratio (AR) bandwidth is significantly broadened. To validate the performance of the proposed antenna, an antenna prototype is fabricated and tested. The fabricated antenna is 54 mm × 54 mm × 0.8 mm in size. The measured -10 dB reflection and 3 dB AR bandwidths are 81.06% (1.68⁻3.97 GHz) and 70.55% (1.89⁻3.95 GHz), respectively. Within the 3 dB AR bandwidth, the measured peak gain is 3.81 dBic. Reasonable agreement is also obtained between the measured and simulated results.

Circular Business: Collaborate and Circulate : a bookreview

NARCIS (Netherlands)

Timmermans, Ratna W.; Witjes, S.|info:eu-repo/dai/nl/381088200

2016-01-01

With their book, “Circular Business: Collaborate and Circulate”, Circular Collaboration, Amersfoort, ISBN: 978-90-824902-0-6, €35, Kraaijenhagen et al. (2016) give companies practical guidance on their contribution to the development of a more circular economy by presenting a practical 10-step

METHOD OF COMPENSATING LOADS FOR SOLVING OF A PROBLEM OF UNSYMMETRIC BENDING OF INFINITE ICE SLAB WITH CIRCULAR OPENING

Directory of Open Access Journals (Sweden)

Elena B. Koreneva

2017-06-01

Full Text Available Unsymmetric flexure of an infinite ice slab with circular opening is under examination. The men-tioned construction is considered as an infinite plate of constant thickness resting on an elastic subgrade which properties are described by Winkler’s model. The plate’s thickness is variable in the area ajoining to the opening. Method of compensating loads is used. Basic and compensating solutions are received. The obtained solutions are produced in closed form in terms of Bessel functions.

Symplectic methods in circular accelerators

International Nuclear Information System (INIS)

Forest, E.

1994-01-01

By now symplectic integration has been applied to many problems in classical mechanics. It is my conviction that the field of particle simulation in circular rings is ideally suited for the application of symplectic integration. In this paper, I present a short description symplectic tools in circular storage rings

76 FR 60593 - Title VI; Proposed Circular

Science.gov (United States)

2011-09-29

..., several of them related to ambiguous language in the existing Circular. The proposed Circular reorganizes... regional entity, and inclusive of public and private entities. This term is used exclusively in Chapter IV... revisions to the Title VI Circular. The section that addresses the existing requirement for a Language...

Investigation Analysis of Crack Growth Arresting with Fasteners in Hybrid Laminated Skin-Stiffener Joint

Science.gov (United States)

Jeevan Kumar, N.; Ramesh Babu, P.

2018-02-01

In recent years carbon fibre-reinforced polymers (CFRP) emerged its increasing demand in aerospace engineering. Due to their high specific strength to weight ratio, these composites offer more characteristics and considerable advantages compared to metals. Metals, unlike composites, offer plasticity effects to evade high stress concentrations during postbuckling. Under compressive load, composite structures show a wide range of damage mechanisms where a set of damage modes combined together might lead to the eventual structural collapse. Crack is one of the most critical damages in fiber composites, which are being employed in primary aircraft structures. A parametric study is conducted to investigate the arrest mechanism of the delamination or crack growth with installation of multiple fasteners when the delamination is embedded in between the skin and stiffener interface.

Molecular photoionisation using synchrotron radiation. Photoelectron photoion coincidence and circular dichroism

International Nuclear Information System (INIS)

Garcia-Macias, Gustavo Adolfo

2002-01-01

The first ionisation potential of the CF 3 radical has been determined in this work from the appearance potential of the CF 3 + fragment, formed in the photofragmentation of CF 3 Br. In obtaining this value special care has been taken in removing the contributions from second order light and internal energy of the fragmenting parent ion. The resulting ionisation potential was found to be in very good agreement with a number of recent theoretical calculations. The valence photoelectron spectra of three monoterpenes such as limonene, carvone and camphor have been recorded along with their mass spectra taken in coincidence with energy selected photoelectrons, providing information about state selected parent ion fragmentation channels. A new photoelectron spectrometer based on the Alien box design has been studied by ray-tracing simulations. It will include a two dimensional position sensitive detector system consisting in two micro channel plates in a chevron stack and a delay-line anode to encode the impact position. It is currently under construction and it is expected to be commissioned by summer 2002. Continuum molecular scattering calculations have been performed in the optically active carvone. We have looked for circular dichroism in the angular distributions of core and valence photoelectron spectra. The values have been found to be of at least four orders of magnitude bigger than the normal circular dichroism in absorption. Experimental results have been obtained for the circular dichroism in the valence and inner shells of camphor and carvone as a function of photon energy. The experiments were performed in the BESSY II and SACO storage rings in Berlin and Orsay respectively. The core results on camphor show a definite difference between the partial cross-sections of the carbonyl carbon Is orbital when switching the helicity of either the light or the enantiomer. The core results on carvone have yet to be properly analysed and are noisier but the circular

Cygnus X-1: Discovery of variable circular polarization

International Nuclear Information System (INIS)

Michalsky, J.J.; Swedlund, J.B.; Stokes, R.A.

1975-01-01

HDE 226868, the optical counterpart of Cyg X-1, has been observed for circular polarization during 1974. Observations in five colors suggest that circular polarization results from an interstellar effect. Measurements of the blue polarization reveal circular polarization variations synchronous with the 5)./sub /6 orbital period. The circular polarization variation appears to be similar to the blue intensity variation

Development of Live-working Robot for Power Transmission Lines

Science.gov (United States)

Yan, Yu; Liu, Xiaqing; Ren, Chengxian; Li, Jinliang; Li, Hui

2017-07-01

Dream-I, the first reconfigurable live-working robot for power transmission lines successfully developed in China, has the functions of autonomous walking on lines and accurately positioning. This paper firstly described operation task and object of the robot; then designed a general platform, an insulator replacement end and a drainage plate bolt fastening end of the robot, presented a control system of the robot, and performed simulation analysis on operation plan of the robot; and finally completed electrical field withstand voltage tests in a high voltage hall as well as online test and trial on actual lines. Experimental results show that by replacing ends of manipulators, the robot can fulfill operation tasks of live replacement of suspension insulators and live drainage plate bolt fastening.

Assessment of Real Heat Transfer Coefficients through Shell and Tube and Plate Heat Exchangers

Directory of Open Access Journals (Sweden)

Dan CONSTANTINESCU

2011-07-01

Full Text Available The purpose of this paper is to present a procedure used in the assessment of the real heat transfer characteristic of shell and tube and plate heat exchangers. The theoretical fundamentals of the procedure are introduced as well as the measured data collection and processing. The theoretical analysis is focused on the adoption of criterial equations which, subjected to certain verification criteria presented in the paper, provide the most credible value of the convection heat transfer coefficients inside the circular and flat tubes. In the end two case studies are presented, one concerning a shell and tube heat exchanger operational at INCERC Thermal Substation and the other concerning a plate heat exchanger tested on the Laboratory Stand of the Department of Building Services and Efficient Use of Energy in Buildings of INCERC Bucharest.

The Use of Explosive Forming for Fastening and Joining Structural and Pressure Components

Science.gov (United States)

Schroeder, J. W.

1985-01-01

Explosive expansion of tubes into tubesheets has been used for over 20 years in the fabrication and repair of shell and tube heat exchangers. The use of explosives to perform these expansions has offered several distinct advantages over other methods. First, the process is fast and economical and can be performed with minimal training of personnel. Secondly, explosive forming does not cause the deleterious metallurgical effects which often result from other forming operations. In addition, the process can be performed remotely without the need for sophisticated handling equipment. The expansion of tubes into tubesheets is only one of many possible fastening and joining applications for which explosive forming can be used to achieve highly successful results. The explosive forming process and where it has been used are described. In addition, some possible adaptations to other joining applications are identified and discussed.

Comparison of turbulent flow through hexagram and hexagon orifices in circular pipes using large-eddy simulation

Energy Technology Data Exchange (ETDEWEB)

Wang, Wei; Nicolleau, Franck C G A; Qin, Ning, E-mail: n.qin@sheffield.ac.uk [Department of Mechanical Engineering, The University of Sheffield, Sheffield, S1 3JD (United Kingdom)

2016-04-15

Characteristics of turbulent flow through a circular, a hexagon and a hexagram orifice with the same flow area in circular pipes are investigated using wall-modelled large-eddy simulation. Good agreements to available experimental data were obtained in both the mean velocity and turbulent kinetic energy. The hexagram orifice with alternating convex and concave corners introduces outwards radial velocity around the concave corners downstream of the orifice plate stronger than the hexagon orifice. The stronger outwards radial velocity transfers high momentum from the pipe centre towards the pipe wall to energize the orifice-forced vortex sheet rolling-up and leads to a delayed vortex break-down. Correspondingly, the hexagram has a more gradual flow recovery to a pipe flow and a reduced pressure drop than the hexagon orifice. Both the hexagon and hexagram orifices show an axis-switching phenomenon, which is observed from both the streamwise velocity and turbulent kinetic energy contours. To the best knowledge of the authors, this is the first comparison of orifice-forced turbulence development, mixing and flow dynamics between a regular and a fractal-based polygonal orifice. (paper)

Hydrodynamics of a flexible plate between pitching rigid plates

Science.gov (United States)

Kim, Junyoung; Kim, Daegyoum

2017-11-01

The dynamics of a flexible plate have been studied as a model problem in swimming and flying of animals and fluid-structure interaction of plants and flags. Motivated by fish schooling and an array of sea grasses, we investigate the dynamics of a flexible plate closely placed between two pitching rigid plates. In most studies on passive deformation of the flexible plate, the plate is immersed in a uniform flow or a wavy flow. However, in this study, the flexible plate experiences periodic deformation by the oscillatory flow generated by the prescribed pitching motion of the rigid plates. In our model, the pitching axes of the rigid plates and the clamping position of the flexible plate are aligned on the same line. The flexible plate shows various responses depending on length and pitching frequency of rigid plates, thickness of a flexible plate, and free-stream velocity. To find the effect of each variable on the response of the flexible plate, amplitude of a trailing edge and modal contribution of a flapping motion are compared, and flow structure around the flexible plate is examined.

Galvanic corrosion study of aluminium alloy plates mounted to stainless and mild steel bolts by accelerated exposure test

OpenAIRE

MREMA, Emmanuel; ITOH, Yoshito; KANEKO, Akira; HIROHATA, Mikihito

2016-01-01

Despite the fact that aluminium alloy members have a proven durability over stainless steel members, their joint fasteners like bolts, nuts and washers are drawn from steel material due to aluminium alloy inferior mechanical properties. Bare contact between aluminium alloy members and stainless steel fasteners results to galvanic corrosion of aluminium alloy members. A corrosion behaviour study was carried out on different aluminium alloy types with different surface treatments mounted to sta...

Development pattern of circular economy in Jiangsu coastland

OpenAIRE

Wang, Liang

2009-01-01

Circular economy is an effective development pattern to balance economic growth, social development and environmental protection. Based on apprehending the connotation of circular economy, this paper fully considers and studies on the future trends in this area according to the theory of circular economy and the empirical circumstances of Jiangsu Coastland. This paper also discusses the circular economy development pattern adopted by Jiangsu coastland during economic and social development fr...

Total and Differential Efficiencies for a Circular Detector Viewing a Circular Radiator of Finite Thickness

Energy Technology Data Exchange (ETDEWEB)

Lauber, A; Tollander, B

1967-08-15

Total and differential detection efficiencies have been computed for a circular detector viewing a circular radiator of finite thickness. Isotropic, cosines and n-p scattering angular emission distributions of the radiated particles are considered. Tables are given for the total efficiencies as well as for the differential efficiencies in the n-p scattering case.

Development of time-of-flight RBS system using multi microchannel plates

International Nuclear Information System (INIS)

Nguyen, N.V.; Abo, S.; Lohner, T.; Sawaragi, H.; Wakaya, F.; Takai, M.

2007-01-01

A new time-of-flight Rutherford backscattering spectroscopy (TOF-RBS) system with two circular microchannel plates (MCPs) installed at a distance of 140 mm from a sample holder and a scattering angle of 125 o and a 100 kV focused ion beam column having a liquid metal ion source (LMIS) of AuSiBe alloy has been assembled to obtain high counting rate and enhanced mass resolution. The possible influence of the two MCPs by logical summation of the output signals on the time resolution was investigated by measuring dedicated thin deposited metallic samples. And, the time resolution was found in the range of 1.5-2 ns

Circular codes revisited: a statistical approach.

Science.gov (United States)

Gonzalez, D L; Giannerini, S; Rosa, R

2011-04-21

In 1996 Arquès and Michel [1996. A complementary circular code in the protein coding genes. J. Theor. Biol. 182, 45-58] discovered the existence of a common circular code in eukaryote and prokaryote genomes. Since then, circular code theory has provoked great interest and underwent a rapid development. In this paper we discuss some theoretical issues related to the synchronization properties of coding sequences and circular codes with particular emphasis on the problem of retrieval and maintenance of the reading frame. Motivated by the theoretical discussion, we adopt a rigorous statistical approach in order to try to answer different questions. First, we investigate the covering capability of the whole class of 216 self-complementary, C(3) maximal codes with respect to a large set of coding sequences. The results indicate that, on average, the code proposed by Arquès and Michel has the best covering capability but, still, there exists a great variability among sequences. Second, we focus on such code and explore the role played by the proportion of the bases by means of a hierarchy of permutation tests. The results show the existence of a sort of optimization mechanism such that coding sequences are tailored as to maximize or minimize the coverage of circular codes on specific reading frames. Such optimization clearly relates the function of circular codes with reading frame synchronization. Copyright © 2011 Elsevier Ltd. All rights reserved.

Building a Circular Future

DEFF Research Database (Denmark)

Merrild, Heidi

2016-01-01

Natural resources are scarce and construction accounts for 40 percent of the material and energy consumption in Europe. This means that a switch to a circular future is necessary. ’Building a Circular Future’ maps out where we are, where we are going, and what is needed for this conversion to take...... on the project’s strategies. The financial result is a profit of DKK 35 million on the structure alone in the demolition of a building built for the cost of DKK 860 million. The total potential for the whole building, calculated in projected material prices, is estimated to be up to 16% of the total construction...... of the circular strategies is not only in the future. Increased flexibility, optimized operation and maintenance, as well as a healthier building, is low-hanging fruit that can be harvested today. The project’s principles can be implemented in industrialized construction in a large scale today. That is proven...

ADMINISTRATIVE CIRCULARS

CERN Multimedia

Division des ressources humaines

2000-01-01

N° 2 (Rev. 1) - March 2000Guidelines and procedures concerning recruitment and probation period of staff membersN° 9 (Rev. 2) - March 2000Staff members contractsN° 16 (Rev. 2) - January 2000TrainingN° 30 (Rev. 1) - January 2000Indemnities and reimbursements upon taking up appointment and termination of contractN° 32 - February 2000Principles and procedures governing complaints of harassmentThese circular have been amended (No 2, N° 9, N° 16 and N° 30) or drawn up (N° 32).Copies are available in the Divisional Secretariats.Note:\tAdministrative and operational circulars, as well as the lists of those in force, are available for consultation in the server SRV4_Home in the Appletalk zone NOVELL (as GUEST or using your Novell username and password), volume PE Division Data Disk.The Word files are available in the folder COM, folder Public, folder ADM.CIRC.docHuman Resources DivisionTel. 74128

Stress Analysis of an Edge-Cracked Plate by using Photoelastic Fringe Phase Shifting Method

International Nuclear Information System (INIS)

Baek, Tae Hyun; Kim, Myung Soo; Cho, Sung Ho

2000-01-01

The method of photoelasticity allows one to obtain principal stress differences and principal stress directions in a photoelastic model. In the classical approach, the photoelastic parameters are measured manually point by point. The previous methods require much time and skill in the identification and measurement of photoelastic data. Fringe phase shifting method has been recently developed and widely used to measure and analyze fringe data in photo-mechanics. This paper presents the test results of photoelastic fringe phase shifting technique for the stress analysis of a circular disk under compression and an edge-cracked plate subjected to tensile load. The technique used here requires four phase stepped photoelastic images obtained from a circular polariscope by rotating the analyzer at 0 .deg. ,45 .deg. ,90 .deg. ,and 135 .deg. . Experimental results are compared with those or FEM. Good agreement between the results can be observed. However, some error may be included if the technique is used to general direction which is not parallel to isoclinic fringe

Experimental studies on the deformation and rupture of thin metal plates subject to underwater shock wave loading

Directory of Open Access Journals (Sweden)

Chen Pengwan

2015-01-01

Full Text Available In this paper, the dynamic deformation and rupture of thin metal plates subject to underwater shock wave loading are studied by using high-speed 3D digital image correlation (3D-DIC. An equivalent device consist of a gas gun and a water anvil tube was used to supplying an exponentially decaying pressure in lieu of explosive detonation which acted on the panel specimen. The thin metal plate is clamped on the end of the shock tube by a flange. The deformation and rupture process of the metal plates subject to underwater shock waves are recorded by two high-speed cameras. The shape, displacement fields and strain fields of the metal plates under dynamic loading are obtained by using VIC-3D digital image correlation software. The strain gauges also were used to monitor the structural response on the selected position for comparison. The DIC data and the strain gauges results show a high level of correlation, and 3D-DIC is proven to be an effective method to measure 3D full-field dynamic response of structures under underwater impact loading. The effects of pre-notches on the failure modes of thin circular plate were also discussed.

Perceptions of Circular Business Models in SMEs

Directory of Open Access Journals (Sweden)

Sebastian-Ion Ceptureanu

2018-05-01

Full Text Available Testing circular economy business models is crucial in understanding Circular Economy features across various industries. This paper analyses Circular Economy perceptions in Romanian SMEs by investigating entrepreneurs from PVC joinery industry. Using a multidimensional framework, ReSOLVE, as a conceptual model, and Lewandowski systematization, we measured 6 business actions and their relations with Value creation. The results of our survey can be described as mixed. Of the 6 business actions of ReSOLVE framework, for half of them (Regenerate, Optimize and Exchange we can definitely conclude that these are correlated with Circular Economy in terms of Value Creation, while for a fourth there are variables significantly correlated without being able to conclude its overall contribution in terms of Value creation. Our empirical investigation contributes to literature development on Circular Economy research in SMEs and a step forward to shape future research initiatives.

Beam propagation modeling of modified volume Fresnel zone plates fabricated by femtosecond laser direct writing.

Science.gov (United States)

Srisungsitthisunti, Pornsak; Ersoy, Okan K; Xu, Xianfan

2009-01-01

Light diffraction by volume Fresnel zone plates (VFZPs) is simulated by the Hankel transform beam propagation method (Hankel BPM). The method utilizes circularly symmetric geometry and small step propagation to calculate the diffracted wave fields by VFZP layers. It is shown that fast and accurate diffraction results can be obtained with the Hankel BPM. The results show an excellent agreement with the scalar diffraction theory and the experimental results. The numerical method allows more comprehensive studies of the VFZP parameters to achieve higher diffraction efficiency.

An Accurate Study on Capacitive Microphone with Circular Diaphragm Using a Higher Order Elasticity Theory

Directory of Open Access Journals (Sweden)

Shakiba Dowlati

Full Text Available Abstract This study has been undertaken to investigate the mechanical behavior of the capacitive microphone with clamped circular diaphragm using modified couple stress theory in comparison to the classical one. Presence of the length scale parameter in modified couple stress theory provides the means to evaluate the size effect on the microphone mechanical behavior. Investigating Pull-in phenomenon and dynamic behavior of the microphone are the matters provided due to the application of a step DC voltage. Also the effects of different air damping coefficients on dynamic pull-in voltage and pull-in time have been studied. The output level or sensitivity of the microphone has been studied by investigating the frequency response in term of magnitude for different length scale parameters to figure out how the length scale parameter affects on the sensitivity of the capacitive microphone. To achieve these ends, the nonlinear differential equation of the circular diaphragm has been extracted using Kirchhoff thin plate theory. Then, a Step-by-Step Linearization Method (SSLM has been used to escape from the nonlinearity of the differential equation. Afterwards, Galerkin-based reduced-order model has been applied to solve the obtained equation.

Photoinduced Circular Anisotropy in Side-Chain Azobenzene Polyesters

DEFF Research Database (Denmark)

Nikolova, L.; Todorov, T.; Ivanov, M.

1997-01-01

We report for the first time the inducing of large circular anisotropy in previously unoriented films of side-chain azobenzene polyesters on illumination with circularly polarized light at a wavelength of 488 nm. The circular dichroism and optical activity are measured simultaneously in real time...

A computational protocol for the study of circularly polarized phosphorescence and circular dichroism in spin-forbidden absorption

DEFF Research Database (Denmark)

Kaminski, Maciej; Cukras, Janusz; Pecul, Magdalena

2015-01-01

We present a computational methodology to calculate the intensity of circular dichroism (CD) in spinforbidden absorption and of circularly polarized phosphorescence (CPP) signals, a manifestation of the optical activity of the triplet–singlet transitions in chiral compounds. The protocol is based...

Effect of instability of vortex streets behind circular cylinder on lock-in oscillation

International Nuclear Information System (INIS)

Masaya Kondo

2005-01-01

Full text of publication follows: The effects of the instability of vortex streets formed in the wakes of a circular cylinder on lock-in oscillation was investigated using a splitter plate and a phase-estimation methodology. The lock-in oscillation at the reduced velocity of 2.5 ≤ Vr < ∼ 3.5 is a self excited oscillation with alternate vortices. The amplitude of the lock-in oscillation is changed with the reduced velocity, although the oscillation frequency and the external force frequency caused by vortices is insensitive to the reduced velocity. Author reported that the amplitude changed with the energy input, which changed with the relationship between the phase of the external force and the phase of the cylinder displacement. The report suggested that the timing of the vortices shedding would change with the reduced velocity. The reason of the timing change, however, has not been clarified yet. This paper presents an explanation of the timing change using the instability of the vortex streets formed in the wake. The distance with a next vortex in a vortex street behind a cylinder at the lock-in condition changes with reduced velocity. On the assumption that the distance between two vortex streets formed in a wake of the cylinder is a constant, only one reduced velocity satisfied the stable condition called 'Karman Vortex Street'. It means that two vortex streets formed at the lock-in condition would be instable essentially, and the vortices would interact each other to form the stable condition. The interaction among the vortices would affect not only for the shed vortices in the wake but also for the growing-up vortex on the cylinder surface. Therefore, the instability of the vortex streets would affect the timing of the vortices shedding. A flow-induced oscillation test using a circular cylinder with a splitter plate was performed to confirm such an instability. The splitter plate was installed in the far wake of the cylinder to terminate the interaction

Self-complementary circular codes in coding theory.

Science.gov (United States)

Fimmel, Elena; Michel, Christian J; Starman, Martin; Strüngmann, Lutz

2018-04-01

Self-complementary circular codes are involved in pairing genetic processes. A maximal [Formula: see text] self-complementary circular code X of trinucleotides was identified in genes of bacteria, archaea, eukaryotes, plasmids and viruses (Michel in Life 7(20):1-16 2017, J Theor Biol 380:156-177, 2015; Arquès and Michel in J Theor Biol 182:45-58 1996). In this paper, self-complementary circular codes are investigated using the graph theory approach recently formulated in Fimmel et al. (Philos Trans R Soc A 374:20150058, 2016). A directed graph [Formula: see text] associated with any code X mirrors the properties of the code. In the present paper, we demonstrate a necessary condition for the self-complementarity of an arbitrary code X in terms of the graph theory. The same condition has been proven to be sufficient for codes which are circular and of large size [Formula: see text] trinucleotides, in particular for maximal circular codes ([Formula: see text] trinucleotides). For codes of small-size [Formula: see text] trinucleotides, some very rare counterexamples have been constructed. Furthermore, the length and the structure of the longest paths in the graphs associated with the self-complementary circular codes are investigated. It has been proven that the longest paths in such graphs determine the reading frame for the self-complementary circular codes. By applying this result, the reading frame in any arbitrary sequence of trinucleotides is retrieved after at most 15 nucleotides, i.e., 5 consecutive trinucleotides, from the circular code X identified in genes. Thus, an X motif of a length of at least 15 nucleotides in an arbitrary sequence of trinucleotides (not necessarily all of them belonging to X) uniquely defines the reading (correct) frame, an important criterion for analyzing the X motifs in genes in the future.

A product design framework for a circular economy

NARCIS (Netherlands)

Van den Berg, M.R.; Bakker, C.A.

2015-01-01

The paper provides a circular economy framework from a product design perspective with tools to aid product designers in applying circular product design in practice. Design research for circular economy has so far mainly been limited to referring to existing fields of research such as design for

77 FR 36428 - Amendment to the International Traffic in Arms Regulations: Definition for “Specially Designed”

Science.gov (United States)

2012-06-19

... Commerce Control List, such as threaded fasteners (e.g., screws, bolts, nuts, nut plates, studs, inserts... excluding from control simple or multi-use parts such as springs, bolts, and rivets, and other types of...

Zernike vs. Bessel circular functions in visual optics.

Science.gov (United States)

Trevino, Juan P; Gómez-Correa, Jesus E; Iskander, D Robert; Chávez-Cerda, Sabino

2013-07-01

We propose the Bessel Circular Functions as alternatives of the Zernike Circle Polynomials to represent relevant circular ophthalmic surfaces. We assess the fitting capabilities of the orthogonal Bessel Circular Functions by comparing them to Zernike Circle Polynomials for approximating a variety of computationally generated surfaces which can represent ophthalmic surfaces. The Bessel Circular Functions showed better modelling capabilities for surfaces with abrupt variations such as the anterior eye surface at the limbus region, and influence functions. From our studies we find that the Bessel Circular Functions can be more suitable for studying particular features of post surgical corneal surfaces. We show that given their boundary conditions and free oscillating properties, the Bessel Circular Functions are an alternative for representing specific wavefronts and can be better than the Zernike Circle Polynomials for some important cases of corneal surfaces, influence functions and the complete anterior corneal surface. © 2013 The Authors Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

Information circulars

International Nuclear Information System (INIS)

1989-04-01

The document summarizes the Information Circulars published by the IAEA under the symbol INFCIRC/ for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A complete list of INFCIRCs in numerical order with their titles is given in the Annex

Photoexcitation circular dichroism in chiral molecules

Science.gov (United States)

Beaulieu, S.; Comby, A.; Descamps, D.; Fabre, B.; Garcia, G. A.; Géneaux, R.; Harvey, A. G.; Légaré, F.; Mašín, Z.; Nahon, L.; Ordonez, A. F.; Petit, S.; Pons, B.; Mairesse, Y.; Smirnova, O.; Blanchet, V.

2018-05-01

Chiral effects appear in a wide variety of natural phenomena and are of fundamental importance in science, from particle physics to metamaterials. The standard technique of chiral discrimination—photoabsorption circular dichroism—relies on the magnetic properties of a chiral medium and yields an extremely weak chiral response. Here, we propose and demonstrate an orders of magnitude more sensitive type of circular dichroism in neutral molecules: photoexcitation circular dichroism. This technique does not rely on weak magnetic effects, but takes advantage of the coherent helical motion of bound electrons excited by ultrashort circularly polarized light. It results in an ultrafast chiral response and the efficient excitation of a macroscopic chiral density in an initially isotropic ensemble of randomly oriented chiral molecules. We probe this excitation using linearly polarized laser pulses, without the aid of further chiral interactions. Our time-resolved study of vibronic chiral dynamics opens a way to the efficient initiation, control and monitoring of chiral chemical change in neutral molecules at the level of electrons.

The velocity measurement by LDV at the simulated plate fuel assembly

International Nuclear Information System (INIS)

Tae Sung Ha

2001-01-01

For a more accurate safety analysis for McMaster Nuclear Reactor (MNR), local velocity measurements in a mock-up of the 18-plate fuel assembly are conducted over the range of M=2.0kg/s to 5.0kg/s (u=0.59m/s to 1.48m/s). To enable the measurement of the mass flow distribution through the channels by Laser Doppler Velocimeter(LDV), the curved fuel plate assembly is modified to flat fuel plates. The experimental result shows that the velocity profile is fairly symmetric for the 1st channel to the 17th subchannel at its center. The velocity in the peripheral area is slightly decreased while that directly above the circular pipe is correspondingly increased due to the effect of blockage by the exit endfitting. The mass flow rate fraction is fairly well distributed from the 1st to the 9th channels; at the outmost channels (1st and 3rd subchannels) the flow is approximately 95-97% of the average channel flow and at the central channels (4th and 8th subchannels) the flow is about 102-105% of the average channel mass flow rate. It is shown that the measured mass flow distribution is consistent with the results of the numerical calculation except 1st and 17th channels. (author)

X-ray magnetic circular dichroism used to image magnetic domains

CERN Document Server

Fischer, P; Kalchgruber, R; Schütz, G M; Schmahl, G; Guttmann, P; Bayreuther, G

1999-01-01

A new technique to image magnetic domain structures has been established by the combination of the high resolution transmission X- ray microscope (TXM) at BESSY I based on the zone plate technique with the X-ray magnetic circular $9 dichroism (X-MCD) providing a huge magnetic contrast. A lateral spatial resolution down to 30 nm could be achieved. Basic features of X-MCD are the inherent element- specificity and the potential to gain information on the local spin $9 and orbital moments of the absorbing species applying magneto-optical sum rules. Key results at the Fe L/sub 3,2/ edges of Fe in a layered GdFe system and at the Co L/sub 3/ edge of a PtCo layered system demonstrate the potential of $9 this microscopy. The images can be recorded in varying magnetic fields which allows to study the evolution of magnetic domains within a complete hysteresis loop. (8 refs).

Limit load and fully plastic stress analysis for circular notched plates and bars using fully plastic analysis

International Nuclear Information System (INIS)

Oh, Chang Kyun; Myung, Man Sik; Kim, Yun Jae; Park, Jin Moo

2005-01-01

For the last four decades, tension test of notched bars has been performed to investigate the effect of stress triaxiality on ductile fracture. To quantify the effect of the notch radius on stress triaxiality, the Bridgman equation is typically used. However, recent works based on detailed finite element analysis have shown that the Bridgman equation is not correct, possibly due to his assumption that strain is constant in the necked ligament. Up to present, no systematic work has been performed on fully plastic stress fields for notched bars in tension. This paper presents fully plastic results for tension of notched bars and plates in plane strain, via finite element limit analysis. The notch radius is systematically varied, covering both un-cracked and cracked cases. Comparison of plastic limit loads with existing solutions shows that existing solutions are accurate for notched plates, but not for notched bars. Accordingly new limit load solutions are given for notched bars. Variations of stress triaxiality with the notch radius and depth are also given, which again indicates that the Bridgman solution for notched bars is not correct and inaccuracy depends on the notch radius and depth

Measurement of the topological charge and index of vortex vector optical fields with a space-variant half-wave plate.

Science.gov (United States)

Liu, Gui-Geng; Wang, Ke; Lee, Yun-Han; Wang, Dan; Li, Ping-Ping; Gou, Fangwang; Li, Yongnan; Tu, Chenghou; Wu, Shin-Tson; Wang, Hui-Tian

2018-02-15

Vortex vector optical fields (VVOFs) refer to a kind of vector optical field with an azimuth-variant polarization and a helical phase, simultaneously. Such a VVOF is defined by the topological index of the polarization singularity and the topological charge of the phase vortex. We present a simple method to measure the topological charge and index of VVOFs by using a space-variant half-wave plate (SV-HWP). The geometric phase grating of the SV-HWP diffracts a VVOF into ±1 orders with orthogonally left- and right-handed circular polarizations. By inserting a polarizer behind the SV-HWP, the two circular polarization states project into the linear polarization and then interfere with each other to form the interference pattern, which enables the direct measurement of the topological charge and index of VVOFs.

Ion beam alignment in the MSX-4 mass spectrometer

International Nuclear Information System (INIS)

Busygin, A.I.; Nevzorov, A.A.; Ul'masbaev, B.Sh.

1977-01-01

A method for electrically adjusting an ion beam in an MSKh-4 mass-spectrometer has been developed. The adjusting system consists of two deflecting plates fastened to the frame of the ion source. By adjusting the potential difference at the plates in the range 0-150 v, one can increase the intensity of the mass-spectrum by a factor of 3 to 5

Breaking the fault tree circular logic

International Nuclear Information System (INIS)

Lankin, M.

2000-01-01

Event tree - fault tree approach to model failures of nuclear plants as well as of other complex facilities is noticeably dominant now. This approach implies modeling an object in form of unidirectional logical graph - tree, i.e. graph without circular logic. However, genuine nuclear plants intrinsically demonstrate quite a few logical loops (circular logic), especially where electrical systems are involved. This paper shows the incorrectness of existing practice of circular logic breaking by elimination of part of logical dependencies and puts forward a formal algorithm, which enables the analyst to correctly model the failure of complex object, which involves logical dependencies between system and components, in form of fault tree. (author)

An experimental study on the impact collapse characteristics of CF/Epoxy circular tubes

International Nuclear Information System (INIS)

Kim, Y.N.; Im, K.H.; Park, J.W.; Yang, I.Y.

2003-01-01

This study is to investigate the energy absorption characteristics of CF/Epoxy (Carbon-Fiber/Epoxy Resin) circular tubes in static and impact tests. The experimental results varied significantly as a function of interlaminar number, orientation angle of outer and trigger. When a CFRP composite tube is crushed, static/impact energy is consumed by friction between the loading plate and the splayed fronds of the tube, by fracture of the fibers, matrix and their interface, and the response is complex and depends on the interaction among the different mechanisms, such as transverse shearing, laminar bending and local buckling. The collapse mode depended upon orientation angle of outer of CFRP tubes and loading status(static/impact). Typical collapse modes of CFRP tubes are wedge collapse mode, splaying collapse mode and fragmentation collapse mode

NUMERICAL MODELING OF STRESSES NEAR THE SURFACE IN THE INGOT OF CIRCULAR SECTION, CRYSTALLIZABLE AT CIRCULAR TORCH SECONDARY COOLING

Directory of Open Access Journals (Sweden)

A. N. Chichko

2004-01-01

Full Text Available The results of computer calculations of the stresses, generated in outside layer of ingot of steel 20 of circular section with diameter 300 mm, in application to one of the industrial technological schemas of RUP “BMZ”, are presented. The segments of compressive and tensile stresses formation along the length of ingot are determined and the principal possibility of production of continuously cast slug of circular section at circular-torch spray cooling is shown.

Three Dimensional Parametric Analyses of Stress Concentration Factor and Its Mitigation in Isotropic and Orthotropic Plate with Central Circular Hole Under Axial In-Plane Loading

Science.gov (United States)

Nagpal, Shubhrata; Jain, Nitin Kumar; Sanyal, Shubhashis

2016-01-01

The problem of finding the stress concentration factor of a loaded rectangular plate has offered considerably analytical difficulty. The present work focused on understanding of behavior of isotropic and orthotropic plate subjected to static in-plane loading using finite element method. The complete plate model configuration has been analyzed using finite element method based software ANSYS. In the present work two parameters: thickness to width of plate (T/A) and diameter of hole to width of plate (D/A) have been varied for analysis of stress concentration factor (SCF) and its mitigation. Plates of five different materials have been considered for complete analysis to find out the sensitivity of stress concentration factor. The D/A ratio varied from 0.1 to 0.7 for analysis of SCF and varied from 0.1 to 0.5 for analyzing the mitigation of SCF. 0.01, 0.05 and 0.1 are considered as T/A ratio for all the cases. The results are presented in graphical form and discussed. The mitigation in SCF reported is very encouraging. The SCF is more sensitive to D/A ratio as compared to T/A.

Cold plate

Energy Technology Data Exchange (ETDEWEB)

Marroquin, Christopher M.; O' Connell, Kevin M.; Schultz, Mark D.; Tian, Shurong

2018-02-13

A cold plate, an electronic assembly including a cold plate, and a method for forming a cold plate are provided. The cold plate includes an interface plate and an opposing plate that form a plenum. The cold plate includes a plurality of active areas arranged for alignment over respective heat generating portions of an electronic assembly, and non-active areas between the active areas. A cooling fluid flows through the plenum. The plenum, at the non-active areas, has a reduced width and/or reduced height relative to the plenum at the active areas. The reduced width and/or height of the plenum, and exterior dimensions of cold plate, at the non-active areas allow the non-active areas to flex to accommodate surface variations of the electronics assembly. The reduced width and/or height non-active areas can be specifically shaped to fit between physical features of the electronics assembly.

Analysis and Experiments on Sea Load and Fastened Mechanics on Pipe Clamps

Directory of Open Access Journals (Sweden)

Wang Zhuo

2017-08-01

Full Text Available When an offshore oil field completed and put into production, new subsea pipelines and the new cable need to be established. Cable protection pipe clamp is used to fix cable protection pipe on the jacket. In order to avoid the problem of traditional steel structure clamp splice, counterpoint, fastening difficulty when installed cable protection pipe under water, reduce the risk and workload of under water, This paper develop a new type of portable connecting riser clamp -“backpack clamp” which solve the riser cable protection pipe difficult underwater installation problem. The main structure of backpack clamp used three valves type structure. The load characteristic of a clamping device was determined by the Morison equation which was a classical theory. Clamp device underwater mechanics analysis model was established. The minimum tension pre-tightening force was determined. The results show that the strength of the base meets the requirements after strength analysis with finite element analysis method, stability and strength experiments, which means the clamp based on resin matrix composite is feasible.

Simplified computational methods for elastic and elastic-plastic fracture problems

Science.gov (United States)

Atluri, Satya N.

1992-01-01

An overview is given of some of the recent (1984-1991) developments in computational/analytical methods in the mechanics of fractures. Topics covered include analytical solutions for elliptical or circular cracks embedded in isotropic or transversely isotropic solids, with crack faces being subjected to arbitrary tractions; finite element or boundary element alternating methods for two or three dimensional crack problems; a 'direct stiffness' method for stiffened panels with flexible fasteners and with multiple cracks; multiple site damage near a row of fastener holes; an analysis of cracks with bonded repair patches; methods for the generation of weight functions for two and three dimensional crack problems; and domain-integral methods for elastic-plastic or inelastic crack mechanics.

Vibrational mode and sound radiation of electrostatic speakers using circular and annular diaphragms

Science.gov (United States)

Huang, Yu-Hsi; Chiang, Hsin-Yuan

2016-06-01

This study modeled two diaphragms comprising a pair of indium tin oxide (ITO) transparent plates sandwiching a vibrating diaphragm to create circular (30 mm radius) and annular (30 mm outer and 3 mm inner radius) push-pull electrostatic speakers. We then measured the displacement amplitudes and mode shapes produced by the devices. Vibration characteristics were used to predict sound pressure levels (SPLs) using the lumped parameter method (LPM) and distributed parameter method (DPM). The two measurement results obtained using a laser system were compared to the SPLs obtained using traditional acoustic measurement (AM) from 20 Hz to 20 kHz in order to verify our predictions. When using LPM and DPM, the SPL prediction results in the first three symmetric modes were in good agreement with the AM results. Under the assumption of linear operations, the DPM and amplitude-fluctuation electronic speckle pattern interferometry (ESPI) techniques proved effective in determining the visualization of mode shape (0,1)-(0,3). The use of ITO plates is a practical technique for the prediction of SPL, as well as measurement of mode shapes. The four evaluation methods, i.e. LPM, DPM, ESPI and AM, present a high degree of consistency with regard to vibrational mode and sound radiation characteristics.

The Baltics on Their Way towards a Circular Economy

Directory of Open Access Journals (Sweden)

Grigoryan A. A.

2017-10-01

Full Text Available Circular economy has been studied extensively both in Europe and worldwide. It is largely viewed as a potential strategy for societal development, aimed to increase prosperity while reducing dependence on raw materials and energy. Many businesses regard circular economy as a way to enhance economic growth and increase profits. Governments across the world actively engage in the discussion about the benefits of a transition to a circular economy and about its impact on employment, economic growth, and the environment. This paper aims to study the major issues of circular economy, to identify its advantages, and to offer an insight into the transition stage the Baltic States are undergoing today on their way to circular economy. It is stressed that the Baltic countries are not fully using the opportunities offered by a circular economy. For example, Latvia’s, Lithuania’s, and Estonia’s recycling rates are significantly below those of other European countries. The Baltics depend heavily on EU financial support. An increase in funding will contribute to the implementation of circular economy technologies.

University Students Alternative Conceptions On Circular Motion

Directory of Open Access Journals (Sweden)

Ian Phil Canlas

2015-08-01

Full Text Available This study attempted to find out university students alternative conceptions on circular motion. An 18-item researcher-compiled and content-validated questionnaire was administered to twenty-six 26 students taking up a program in Bachelor in Secondary Education-Physical Science in their second year enrolled in a course on mechanics. Results revealed that majority of the students possess alternative conceptions on circular motion specifically along velocity acceleration and force. Moreover results showed the inconsistencies in the students understanding of circular motion concepts.

Architectural Surfaces and Structures from Circular Arcs

KAUST Repository

Shi, Ling

2013-01-01

the most attention from geometry researchers. In this thesis, we aim to realize this process with simple geometric primitives, circular arcs. We investigate architectural surfaces and structures consisting of circular arcs. Our focus is lying on how

Environmental issues elimination through circular economy

Energy Technology Data Exchange (ETDEWEB)

Špirková, M., E-mail: marta.spirkova@stuba.sk; Pokorná, E.; Šujanová, J.; Samáková, J. [Paulínska 16, 917 24 Trnava, Slovakia, Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava (Slovakia)

2016-04-21

Environmental efforts of European Union are currently going towards circular economy. Tools like Extended Producer Responsibility and Eco-design were established. The circular economy deals with resources availability issue on one hand and waste management on the other hand. There are few pioneering companies all over the world with some kind of circular economy practice. Generally the concept is not very wide-spread. The paper aims to evaluate possibility of transition towards circular economy in Slovak industrial companies. They need to have an active approach to material treatment of their products after usage stage. Innovation is another important pre-condition for the transition. Main problem of current cradle to grave system is landfilling of valuable materials after one cycle of usage. Their potential value for next manufacturing cycles is lost. Companies may do not see connection between waste management and material resource prices and volatility of supplies. Municipalities are responsible for municipal waste collection and treatment in Slovakia. The circular economy operates by cradle to cradle principle. Company manages material flow until the material comes back to the beginning of manufacturing process by itself or by another partners. Stable material supplies with quite low costs are provided this way. It is necessary to deal with environmental problems in phase of product design. Questionnaire survey results show on one hand low involvement of industrial companies in waste management area, however on the other hand they are open to environmental innovations in future.

Environmental issues elimination through circular economy

International Nuclear Information System (INIS)

Špirková, M.; Pokorná, E.; Šujanová, J.; Samáková, J.

2016-01-01

Environmental efforts of European Union are currently going towards circular economy. Tools like Extended Producer Responsibility and Eco-design were established. The circular economy deals with resources availability issue on one hand and waste management on the other hand. There are few pioneering companies all over the world with some kind of circular economy practice. Generally the concept is not very wide-spread. The paper aims to evaluate possibility of transition towards circular economy in Slovak industrial companies. They need to have an active approach to material treatment of their products after usage stage. Innovation is another important pre-condition for the transition. Main problem of current cradle to grave system is landfilling of valuable materials after one cycle of usage. Their potential value for next manufacturing cycles is lost. Companies may do not see connection between waste management and material resource prices and volatility of supplies. Municipalities are responsible for municipal waste collection and treatment in Slovakia. The circular economy operates by cradle to cradle principle. Company manages material flow until the material comes back to the beginning of manufacturing process by itself or by another partners. Stable material supplies with quite low costs are provided this way. It is necessary to deal with environmental problems in phase of product design. Questionnaire survey results show on one hand low involvement of industrial companies in waste management area, however on the other hand they are open to environmental innovations in future.

Environmental issues elimination through circular economy

Science.gov (United States)

Špirková, M.; Pokorná, E.; Šujanová, J.; Samáková, J.

2016-04-01

Environmental efforts of European Union are currently going towards circular economy. Tools like Extended Producer Responsibility and Eco-design were established. The circular economy deals with resources availability issue on one hand and waste management on the other hand. There are few pioneering companies all over the world with some kind of circular economy practice. Generally the concept is not very wide-spread. The paper aims to evaluate possibility of transition towards circular economy in Slovak industrial companies. They need to have an active approach to material treatment of their products after usage stage. Innovation is another important pre-condition for the transition. Main problem of current cradle to grave system is landfilling of valuable materials after one cycle of usage. Their potential value for next manufacturing cycles is lost. Companies may do not see connection between waste management and material resource prices and volatility of supplies. Municipalities are responsible for municipal waste collection and treatment in Slovakia. The circular economy operates by cradle to cradle principle. Company manages material flow until the material comes back to the beginning of manufacturing process by itself or by another partners. Stable material supplies with quite low costs are provided this way. It is necessary to deal with environmental problems in phase of product design. Questionnaire survey results show on one hand low involvement of industrial companies in waste management area, however on the other hand they are open to environmental innovations in future.

The Circular Economy between Desiderates and Realities.

Directory of Open Access Journals (Sweden)

Tăchiciu Laurentiu

2018-05-01

Full Text Available The present issue of Amfiteatru Economic Journal addresses the subject of the circular economy, bringing together research contributions to a better understanding of the current state and perspectives of the adoption of economic and business models conceived to give resources’ highest utility and value in every stage by reducing waste, reusing and recycling. Contributors are approaching the circular economy from different perspectives. Some are concerned with the macroeconomic and social conditions accompanying a higher circularity in the economy, while others focus on businesses’ and individuals’ behaviours.

Non-linear finite element modelling and analysis of the effect of gasket creep-relaxation on circular bolted flange connections

International Nuclear Information System (INIS)

Luyt, P.C.B.; Theron, N.J.; Pietra, F.

2017-01-01

It is well known that gasket creep-relaxation results in a reduction of contact pressure between the surface of a gasket and the face of a flange over an extended period of time. This reduction may result in the subsequent failure of the circular bolted flange connection due to leakage. In this paper a pair of flat and raised face integral flanges, PN 10 DN 50 (in accordance with the European EN 1092-1 standard), with non-asbestos compressed fibre ring gaskets with aramid and a nitrile rubber binder were considered. Finite element modelling and analyses were done, for both the circular bolted flange configurations, during the seating condition. The results of the finite element analyses were experimentally validated. It was found that the number of bolt tightening increments as well as the time between the bolt tightening increments had a significant impact on the effect which gasket creep-relaxation had after the seating condition. An increase in either the number of bolting increments or the time between the bolting increments will reduce the effect which gasket creep-relaxation has once the bolts had been fastened. Based on these results it is possible to develop an optimisation scheme to minimize the effect which gasket creep-relaxation has on the contact pressure between the face of the flange and the gasket, after seating, by either increasing or decreasing the number of bolt tightening increments or the time between the bolt tightening increments. - Highlights: • Number of bolt tightening increments and time between bolt tightening increments had significant impact on effect of gasket creep-relaxation after the seating condition. • Impact of gasket creep-relaxation during seating and operating phases investigated by means of finite element analysis and experimentally verified. • Possible to develop optimisation scheme to minimize effect ofh gasket creep-relaxation on contact pressure between flange face and gasket. • Knowing the contact pressure is

The Circular Economy: In Practice-focused Undergraduate Engineering Education

DEFF Research Database (Denmark)

Knudby, Torben; Larsen, Samuel

2017-01-01

The growth of the planet’s population makes the traditional industrial model of “take, make and waste” unsustainable. The circular economy, in which resources are continuously reused, offers a solution. For manufacturers of durable goods the circular economy requires a well-functioning circular...

Flow-induced vibration of circular cylindrical structures

International Nuclear Information System (INIS)

Chen, S.S.

1985-06-01

This report summarizes the flow-induced vibration of circular cylinders in quiescent fluid, axial flow, and crossflow, and applications of the analytical methods and experimental data in design evaluation of various system components consisting of circular cylinders. 219 figs., 30 tabs

Eco-Innovation in Circular Agri-Business

Directory of Open Access Journals (Sweden)

Dong-Her Shih

2018-04-01

Full Text Available This study constructs a theory of eco-innovation in circular agri-business. Although previous studies have discussed eco-innovation in circular agri-business, they did not address eco-innovation from the perspective of a closed-loop sustainable supply chain. Hence, this study applied the fuzzy TOPSIS method to conduct the analysis and determine the interrelationship between eco-innovation and the closed-loop concept. The results are consistent with the theory and a significant improvement in terms of the decisive attributes. The findings suggest that improving water management, relationships with suppliers, knowledge sharing, environmental management systems, and new product and service development are the most effective and efficient ways to build eco-innovation in circular agri-business. The managerial and theoretical implications are discussed.

Optics modules for circular accelerator design

International Nuclear Information System (INIS)

Brown, K.L.; Servranckx, R.V.

1986-05-01

The first-order differential equations of motion for a single particle in a closed circular machine are solved, introducing the concepts of phase shift, beta functions, and the Courant-Snyder invariant. The transfer matrix between two points in the machine is derived as a function of the phase shift and the parameters contained in the Courant-Snyder invariant. Typical optical modules used in circular machine designs are introduced and related to their characteristic transfer matrix elements, the phase shift through them, and the Courant-Snyder-Twiss parameters. The systematics of some elementary phase ellipse matching problems between optical modules are discussed. Second-order optical modules are discussed, including how they are used to provide the momentum bandwidth needed for the design of a typical circular machine

Equatorial circular motion in Kerr spacetime

International Nuclear Information System (INIS)

Pugliese, Daniela; Quevedo, Hernando; Ruffini, Remo

2011-01-01

We analyze the properties of circular orbits of test particles on the equatorial plane of a rotating central mass whose gravitational field is described by the Kerr spacetime. For rotating black holes and naked singularities we explore all the spatial regions where circular orbits can exist and analyze the behavior of the energy and the angular momentum of the corresponding test particles. In particular, we find all the radii at which a test particle can have zero angular momentum due to the repulsive gravity effects generated by naked singularities. We classify all the stability zones of circular orbits. It is shown that the geometric structure of the stability zones of black holes is completely different from that of naked singularities.

Characteristics of a Circular Logic and Its Treatment

International Nuclear Information System (INIS)

Lim, Ho-Gon; Han, Sang-Hoon; Yang, Joon Eon

2007-01-01

A circular logic or a logical loop is defined as the infinite circulation of supporting relations due to their mutual dependencies among the systems in the Fault Tree Analysis (FTA). While many methods to break the circular logic have been developed and used in the fault tree quantification codes, the general solution for a circular logic and its breaking methods are not generally known as yet. This paper presents an analytic solution for circular logics in which the systems are linearly interrelated with each other. Then, a general treatment of circular logics is discussed. To formulate the analytic solution, the relations among systems in the fault tree structure are described by the Boolean equations. The solution is, then, obtained from the successive substitutions of the Boolean equations, which is equivalent to the attaching processes of interrelated system's fault tree to a given fault tree. The solution for three interrelated systems and their independent fault tree structures are given as an example

Circular arc structures

KAUST Repository

Bo, Pengbo; Pottmann, Helmut; Kilian, Martin; Wang, Wen Ping; Wallner, Johannes

2011-01-01

and connecting elements as well as repetition of costly parts. This paper proposes so-called circular arc structures as a means to faithfully realize freeform designs without giving up smooth appearance. In contrast to non-smooth meshes with straight edges where

21 CFR 888.3060 - Spinal intervertebral body fixation orthosis.

Science.gov (United States)

2010-04-01

... the plates. A braided cable is threaded through each eye-type screw. The cable is tightened with a tension device and it is fastened or crimped at each eye-type screw. The device is used to apply force to...

Development of background reduced Fresnel phase zone plate

International Nuclear Information System (INIS)

Tamari, Yohei; Azechi, Hiroshi

2004-01-01

In study of hot and dense plasma, a high spatial resolution (a few microns) x-ray imaging is very important to observe these plasmas. The Fresnel phase zone plate (FPZP) consists of alternately material and transparent circular annuli placed concentrically, which image x rays using diffraction x rays from all annuli. FPZP have imaged 4.7-4.77 keV x rays with 2.2 μm spatial resolution. However FPZP has a problem that background level is comparable to signal level. In subtraction of background, the error of 10% is caused. For the accurate background subtraction, we designed new FPZP, which consist of three β layers of a transparent zone and two material zones. The new design FPZP parameters (thickness of material zones, each zone width) have been optimized, and in that optimum design signal-to-background ratio is 4 times better than conventional two layers FPZP

The Corrosion Control of Fastening Systems for Aircraft Carrier Steam Catapults

Science.gov (United States)

1976-03-31

2, External Threaded Dolt or Stud. LML 2. 68 1NAEC-ENG 7868 PAGE 28 rf I MI 6 LL 4140 - PIAt -0, M1V 7 A) AEC-ENG 7868 PAGE 29 -- ---T-T- - -- 1 . ’a...corroded. comontarhare mat 0.6 Oil tmmncerbore black. senste be rest stained. stained. No. 6 Sm plating on hed, lead rusty with sae plating Som

The circular economy applied to local communities

NARCIS (Netherlands)

van der Blonk, Heico; van Spijk, Alex; van der Schoor, Tineke

2015-01-01

Based on a theoretical discussion the main difference between models of lineair economy and circular economy are elaborated; (1) Elimination of waste is essential the circulation of circular flows and reclamation of (raw) materials; this requires mechanisms for the return of obsolete materials. (2)

Radical Circular Economy

NARCIS (Netherlands)

Prins, M.; Mohammadi, S.; Slob, N.

2015-01-01

Recently the Circular Economy (CE) concept has gained momentum in the Netherlands, propounding that environmental impact reduction can provide a significant positive economical impulse. The government, larger parts of the industry as a whole, as well as the construction industry, has warmly received

METHOD OF CONJUGATED CIRCULAR ARCS TRACING

Directory of Open Access Journals (Sweden)

N. Ageyev Vladimir

2017-01-01

Full Text Available The geometric properties of conjugated circular arcs connecting two points on the plane with set directions of tan- gent vectors are studied in the work. It is shown that pairs of conjugated circular arcs with the same conditions in frontier points create one-parameter set of smooth curves tightly filling all the plane. One of the basic properties of this set is the fact that all coupling points of circular arcs are on the circular curve going through the initially given points. The circle radius depends on the direction of tangent vectors. Any point of the circle curve, named auxiliary in this work, determines a pair of conjugated arcs with given boundary conditions. One more condition of the auxiliary circle curve is that it divides the plane into two parts. The arcs going from the initial point are out of the circle limited by this circle curve and the arcs coming to the final point are inside it. These properties are the basis for the method of conjugated circular arcs tracing pro- posed in this article. The algorithm is rather simple and allows to fulfill all the needed plottings using only the divider and ruler. Two concrete examples are considered. The first one is related to the problem of tracing of a pair of conjugated arcs with the minimal curve jump when going through the coupling point. The second one demonstrates the possibility of trac- ing of the smooth curve going through any three points on the plane under condition that in the initial and final points the directions of tangent vectors are given. The proposed methods of conjugated circular arcs tracing can be applied in solving of a wide variety of problems connected with the tracing of cam contours, for example pattern curves in textile industry or in computer-aided-design systems when programming of looms with numeric control.

Culture as a Caveat Towards Circular Economy

DEFF Research Database (Denmark)

Guerrieri, Valeria

2015-01-01

Circular economy represents an economic and political challenge, as well as a cultural one, requiring a massive transformation on all levels of society. But why is cultural change so important to understanding today’s economy and how can the circular model be considered a truly cross-cultural...

Primal-dual path-following algorithms for circular programming

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Baha Alzalg

2017-06-01

Full Text Available Circular programming problems are a new class of convex optimization problems that include second-order cone programming problems as a special case‎. ‎Alizadeh and Goldfarb [Math‎. ‎Program‎. ‎Ser‎. ‎A 95 (2003 3--51] introduced primal-dual path-following algorithms for solving second-order cone programming problems‎. ‎In this paper‎, ‎we generalize their work by using the machinery of Euclidean Jordan algebras associated with the circular cones to derive primal-dual path-following interior point algorithms for circular programming problems‎. ‎We prove polynomial convergence of the proposed algorithms by showing that the circular logarithmic barrier is a strongly self-concordant barrier‎. ‎The numerical examples show the path-following algorithms are simple and efficient‎.

Research on the development and countermeasures for circular economy

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

Ecological economics and sustainable development economics are the basic theories to research on circular economy. Through the systemically research on the relationship of the three above, this paper thinks that the reuse and recycle of circular economy ts a way that the stall is mended after a sheep is lost. Although the reduction technically controls the production process, it cannot solve the waste caused by blind production and excess competition. We have experienced variety obstacles when implementing the circular economy, whose main reason ts the conflict between the individual ration and the social ration. Therefore, only when the individual ration and social ration incline to conformity,the cooperating Nash equilibrium will be appeared. In order to realize the harmony of ecology, economy and society, we have to explore effective evaluation theory. This paper cites the "five flows of wealth operation theory"from professor Ma Chuandong to search operation mechanism of circular economy, makes clear the developing thoughts of circular economy based on the realities, and brings forward some countermeasures to develop circular economy based on the above theoretical analysis.

Radiation shielding plate

International Nuclear Information System (INIS)

Kobayashi, Torakichi; Sugawara, Takeo.

1983-01-01

Purpose: To reduce the weight and stabilize the configuration of a radiation shielding plate which is used in close contact with an object to be irradiated with radiation rays. Constitution: The radiation shielding plate comprises a substrate made of lead glass and a metallic lead coating on the surface of the substrate by means of plating, vapor deposition or the like. Apertures for permeating radiation rays are formed to the radiation shielding plate. Since the shielding plate is based on a lead glass plate, a sufficient mechanical strength can be obtained with a thinner structure as compared with the conventional plate made of metallic lead. Accordingly, if the shielding plate is disposed on a soft object to be irradiated with radiation rays, the object and the plate itself less deform to obtain a radiation irradiation pattern with distinct edges. (Moriyama, K.)

Plating on difficult-to-plate metals: what's new

International Nuclear Information System (INIS)

Wiesner, H.J.

1980-01-01

Some of the changes since 1970 in procedures for plating on such materials as titanium, molybdenum, silicon, aluminum, and gallium arsenide are summarized. While basic procedures for plating some of these materials were developed as many as 30 to 40 years ago, changes in the end uses of the plated products have necessitated new plating processes. In some cases, vacuum techniques - such as ion bombardment, ion implantation, and vacuum metallization - have been introduced to improve the adhesion of electrodeposits. In other cases, these techniques have been used to deposit materials upon which electrodeposits are required

Modal approach for nonlinear vibrations of damped impacted plates: Application to sound synthesis of gongs and cymbals

Science.gov (United States)

Ducceschi, M.; Touzé, C.

2015-05-01

This paper presents a modal, time-domain scheme for the nonlinear vibrations of perfect and imperfect plates. The scheme can take into account a large number of degrees-of-freedom and is energy-conserving. The targeted application is the sound synthesis of cymbals and gong-like musical instruments, which are known for displaying a strongly nonlinear vibrating behaviour. This behaviour is typical of a wave turbulence regime, in which the wide-band spectrum of excited modes is observable in the form of an energy cascade. The modal method is selected for its versatility in handling complex damping laws that can be implemented easily by selecting appropriate damping values in each one of the modal equations. In the first part of the paper, the modal method is explained in its generality, and it will be seen that the method is valid for plates with arbitrary geometry and boundary conditions as long as the eigenmodes are known. Secondly, a time-integration, energy-conserving scheme for perfect and imperfect plates is presented, and implementation comments are given in order to treat efficiently the high-dimensionality of the resulting dynamical system. The scheme is run with appropriate parameters in order to produce sound samples. A simple impact law is considered for the excitation, whereas the flexibility of the method is highlighted by showing simulations for free-edge circular plates and simply-supported rectangular plates, together with various damping laws.

New Challenges to the automotive fasteners and cold formed parts in the chinese markets

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Chen Jin Guang

2015-01-01

Full Text Available Despite of substantial cold forming related R&D, innovations and new inventions have been achieved and reported by research institutes and famous industrial organisations, many small and medium size enterprises in the third world or developing countries considering this R&D activities is too luxury. Most of the third world cold forming factories still dependent on previously successful experiences by using trial an error methods. The author does not make attempt to write a scientific research paper on metal forming processes but, instead, to report the effect, application and impact of the previous and on-going metal forming related research work to the cold forming industry in China. This paper highlights the effect of 1 efficient manufacturing practices, 2 upgrading in process technology and 3improved machines capabilities in upgrading the cold forming operation. Three real-life cold forming examples from Ritai are illustrated showing the transformation from an automotive fasteners maker into a cold formed parts manufacturer.

Plating laboratory

International Nuclear Information System (INIS)

Seamster, A.G.; Weitkamp, W.G.

1984-01-01

The lead plating of the prototype resonator has been conducted entirely in the plating laboratory at SUNY Stony Brook. Because of the considerable cost and inconvenience in transporting personnel and materials to and from Stony Brook, it is clearly impractical to plate all the resonators there. Furthermore, the high-beta resonator cannot be accommodated at Stony Brook without modifying the set up there. Consequently the authors are constructing a plating lab in-house

Circular Bioassay Platforms for Applications in Microwave-Accelerated Techniques.

Science.gov (United States)

Mohammed, Muzaffer; Clement, Travis C; Aslan, Kadir

2014-12-02

In this paper, we present the design of four different circular bioassay platforms, which are suitable for homogeneous microwave heating, using theoretical calculations (i.e., COMSOL™ multiphysics software). Circular bioassay platforms are constructed from poly(methyl methacrylate) (PMMA) for optical transparency between 400-800 nm, has multiple sample capacity (12, 16, 19 and 21 wells) and modified with silver nanoparticle films (SNFs) to be used in microwave-accelerated bioassays (MABs). In addition, a small monomode microwave cavity, which can be operated with an external microwave generator (100 W), for use with the bioassay platforms in MABs is also developed. Our design parameters for the circular bioassay platforms and monomode microwave cavity during microwave heating were: (i) temperature profiles, (ii) electric field distributions, (iii) location of the circular bioassay platforms inside the microwave cavity, and (iv) design and number of wells on the circular bioassay platforms. We have also carried out additional simulations to assess the use of circular bioassay platforms in a conventional kitchen microwave oven (e.g., 900 W). Our results show that the location of the circular bioassay platforms in the microwave cavity was predicted to have a significant effect on the homogeneous heating of these platforms. The 21-well circular bioassay platform design in our monomode microwave cavity was predicted to offer a homogeneous heating pattern, where inter-well temperature was observed to be in between 23.72-24.13°C and intra-well temperature difference was less than 0.21°C for 60 seconds of microwave heating, which was also verified experimentally.

An integrated tunable isolator based on NiZn film fabricated by spin-spray plating

Science.gov (United States)

Guo, Rongdi; Lin, Hwaider; Shi, Wei; Gao, Yuan; Wang, Zhiguang; Sun, Nian Xiang; Yu, Zhong; Lan, Zhongwen

2018-05-01

An innovative type of tunable isolator with a planar comb-like microstrip transmission line, which generate circular polarization magnetic field, has been realized with polycrystalline NiZn ferrite thick films fabricated by spin-spray plating (SSP) process with thickness of 10μm. The phase compositions, microstructure, magnetic hysteresis loop, and ferromagnetic resonance (FMR) linewidth of NiZn ferrite thick films have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and electron spin resonance (ESR) spectrometer, respectively. The NiZn ferrite thick films possess 4800Gauss saturation magnetization and 190Oe FMR linewidth measured at X-band. With an in-plane dc magnetic bias perpendicular to the comb-like microstrip transmission line, the transmission direction of left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) were proved to be opposite. The non-reciprocal ferromagnetic resonance absorption leads to 11.6dB isolation and 5.78dB insertion loss at 17.57GHz with magnetic bias field of 3.5kOe. Furthermore, with external in-plane magnetic fields range from 0.5kOe to 3.5kOe, the central frequency was tuned from 5.63GHz to 17.57GHz. The state-of-the-art tunable isolator with a planar comb-like microstrip transmission line exhibit a great potential to be applied in different microwave components and radar system.

Designing the Business Models for Circular Economy—Towards the Conceptual Framework

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Mateusz Lewandowski

2016-01-01

Full Text Available Switching from the current linear model of economy to a circular one has recently attracted increased attention from major global companies e.g., Google, Unilever, Renault, and policymakers attending the World Economic Forum. The reasons for this are the huge financial, social and environmental benefits. However, the global shift from one model of economy to another also concerns smaller companies on a micro-level. Thus, comprehensive knowledge on designing circular business models is needed to stimulate and foster implementation of the circular economy. Existing business models for the circular economy have limited transferability and there is no comprehensive framework supporting every kind of company in designing a circular business model. This study employs a literature review to identify and classify the circular economy characteristics according to a business model structure. The investigation in the eight sub-domains of research on circular business models was used to redefine the components of the business model canvas in the context of the circular economy. Two new components—the take-back system and adoption factors—have been identified, thereby leading to the conceptualization of an extended framework for the circular business model canvas. Additionally, the triple fit challenge has been recognized as an enabler of the transition towards a circular business model. Some directions for further research have been outlined, as well.

Create Your Plate

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Full Text Available ... Plate Share Create Your Plate ! Share: Seven Simple Steps to Create Your Plate It's simple and effective ... foods within each food category. Try these seven steps to get started: Using your dinner plate, put ...

Safety catching device for pipe lines in missile shielding cylinders of nuclear power plants

International Nuclear Information System (INIS)

Hering, S.; Doll, B.

1975-01-01

The safety catching device for pipes in the missile shielding cylinders consists of a flexible steel cable surrounding the pipe in a distance in U-shape. The arrester cable - which works as a spring and is freely movable in all directions - is attached to the cylinder wall. For this, the ends of the cable are primarily fastened to anchor boxes which are then inserted in a stay tube with the same axis as the cable ends. The anchor boxes are fastened to the outer wall of the missile shielding cylinder by anchor bolts and holding plates. (DG/AK) [de

The protein circular dichroism data bank, a Web-based site for access to circular dichroism spectroscopic data.

Science.gov (United States)

Whitmore, Lee; Woollett, Benjamin; Miles, Andrew J; Janes, Robert W; Wallace, B A

2010-10-13

The Protein Circular Dichroism Data Bank (PCDDB) is a newly released resource for structural biology. It is a web-accessible (http://pcddb.cryst.bbk.ac.uk) data bank for circular dichroism (CD) and synchrotron radiation circular dichroism (SRCD) spectra and their associated experimental and secondary metadata, with links to protein sequence and structure data banks. It is designed to provide a public repository for CD spectroscopic data on macromolecules, to parallel the Protein Data Bank (PDB) for crystallographic, electron microscopic, and nuclear magnetic resonance spectroscopic data. Similarly to the PDB, it includes validation checking procedures to ensure good practice and the integrity of the deposited data. This paper reports on the first public release of the PCDDB, which provides access to spectral data that comprise standard reference datasets. Copyright © 2010 Elsevier Ltd. All rights reserved.

Lithospheric flexure under the Hawaiian volcanic load: Internal stresses and a broken plate revealed by earthquakes

Science.gov (United States)

Klein, Fred W.

2016-01-01

Several lines of earthquake evidence indicate that the lithospheric plate is broken under the load of the island of Hawai`i, where the geometry of the lithosphere is circular with a central depression. The plate bends concave downward surrounding a stress-free hole, rather than bending concave upward as with past assumptions. Earthquake focal mechanisms show that the center of load stress and the weak hole is between the summits of Mauna Loa and Mauna Kea where the load is greatest. The earthquake gap at 21 km depth coincides with the predicted neutral plane of flexure where horizontal stress changes sign. Focal mechanism P axes below the neutral plane display a striking radial pattern pointing to the stress center. Earthquakes above the neutral plane in the north part of the island have opposite stress patterns; T axes tend to be radial. The M6.2 Honomu and M6.7 Kiholo main shocks (both at 39 km depth) are below the neutral plane and show radial compression, and the M6.0 Kiholo aftershock above the neutral plane has tangential compression. Earthquakes deeper than 20 km define a donut of seismicity around the stress center where flexural bending is a maximum. The hole is interpreted as the soft center where the lithospheric plate is broken. Kilauea's deep conduit is seismically active because it is in the ring of maximum bending. A simplified two-dimensional stress model for a bending slab with a load at one end yields stress orientations that agree with earthquake stress axes and radial P axes below the neutral plane. A previous inversion of deep Hawaiian focal mechanisms found a circular solution around the stress center that agrees with the model. For horizontal faults, the shear stress within the bending slab matches the slip in the deep Kilauea seismic zone and enhances outward slip of active flanks.

Codon Distribution in Error-Detecting Circular Codes

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Elena Fimmel

2016-03-01

Full Text Available In 1957, Francis Crick et al. suggested an ingenious explanation for the process of frame maintenance. The idea was based on the notion of comma-free codes. Although Crick’s hypothesis proved to be wrong, in 1996, Arquès and Michel discovered the existence of a weaker version of such codes in eukaryote and prokaryote genomes, namely the so-called circular codes. Since then, circular code theory has invariably evoked great interest and made significant progress. In this article, the codon distributions in maximal comma-free, maximal self-complementary C3 and maximal self-complementary circular codes are discussed, i.e., we investigate in how many of such codes a given codon participates. As the main (and surprising result, it is shown that the codons can be separated into very few classes (three, or five, or six with respect to their frequency. Moreover, the distribution classes can be hierarchically ordered as refinements from maximal comma-free codes via maximal self-complementary C3 codes to maximal self-complementary circular codes.

Codon Distribution in Error-Detecting Circular Codes.

Science.gov (United States)

Fimmel, Elena; Strüngmann, Lutz

2016-03-15

In 1957, Francis Crick et al. suggested an ingenious explanation for the process of frame maintenance. The idea was based on the notion of comma-free codes. Although Crick's hypothesis proved to be wrong, in 1996, Arquès and Michel discovered the existence of a weaker version of such codes in eukaryote and prokaryote genomes, namely the so-called circular codes. Since then, circular code theory has invariably evoked great interest and made significant progress. In this article, the codon distributions in maximal comma-free, maximal self-complementary C³ and maximal self-complementary circular codes are discussed, i.e., we investigate in how many of such codes a given codon participates. As the main (and surprising) result, it is shown that the codons can be separated into very few classes (three, or five, or six) with respect to their frequency. Moreover, the distribution classes can be hierarchically ordered as refinements from maximal comma-free codes via maximal self-complementary C(3) codes to maximal self-complementary circular codes.

Microstructure and Properties of Ti-5553 Alloy for Aerospace Fasteners

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ZHAO Qing-yun

2017-10-01

Full Text Available The effect of heat treatment on microstructure and mechanical properties of Ti-5553 alloy was investigated by scanning electron microscopy (SEM and transmission electron microscopy (TEM. The results show that when the alloy is treated in α+β phase zone, tensile strength decreases with raising solution temperature due to decreasing the content of primary α-phase and increasing the size and volume fraction of β phase. A lot of secondary α-phase precipitates from grain boundary and intragranular with β phase transformation during aging treatment. The size of secondary α-phase has significant influence on tensile strength, secondary α-phase coarsens gradually with the increase of aging temperature, resulting in the decrease of tensile strength. It is suggested that for 1240MPa aerospace fasteners the solution temperature of Ti-5553 should be under Tβ, thus adequate β phase, where a lot of secondary α phase precipitates from, is good for the required high strength. Meanwhile, a certain percentage of primary α-phase is kept for acquiring good ductility and toughness. After solution treatment at 810-820℃ for 1.5h, water quenching plus aging at 510℃ for 10h, Ti-5553 shows a better mechanical property with tensile strength 1500MPa, elongation 14.8% and reduction of cross-section area 38.6%. Lots of dimples can be found in tensile fracture after solution treatment and solution+aging treatment, which demonstrate Ti-5553 with good ductility and toughness.

A novel x-ray circularly polarized ranging method

International Nuclear Information System (INIS)

Song Shi-Bin; Xu Lu-Ping; Zhang Hua; Shen Yang-He; Gao Na

2015-01-01

Range measurement has found multiple applications in deep space missions. With more and further deep space exploration activities happening now and in the future, the requirement for range measurement has risen. In view of the future ranging requirement, a novel x-ray polarized ranging method based on the circular polarization modulation is proposed, termed as x-ray circularly polarized ranging (XCPolR). XCPolR utilizes the circular polarization modulation to process x-ray signals and the ranging information is conveyed by the circular polarization states. As the circular polarization states present good stability in space propagation and x-ray detectors have light weight and low power consumption, XCPolR shows great potential in the long-distance range measurement and provides an option for future deep space ranging. In this paper, we present a detailed illustration of XCPolR. Firstly, the structure of the polarized ranging system is described and the signal models in the ranging process are established mathematically. Then, the main factors that affect the ranging accuracy, including the Doppler effect, the differential demodulation, and the correlation error, are analyzed theoretically. Finally, numerical simulation is carried out to evaluate the performance of XCPolR. (paper)

Circular relativistic motion of two identical bodies

International Nuclear Information System (INIS)

Shavokhina, N.S.

1983-01-01

Circular relativistic motion of two bodies as a solution of the earlier obtained equations with a deflecting argument where the self-deflection of the argument is an unknown function of time is considered. In case of circular motion the argument deflection is independent from time and it is the root of the transcendental equation obtained in the paper

Single particle dynamics in circular accelerators

International Nuclear Information System (INIS)

Ruth, R.D.

1986-10-01

The purpose of this paper is to introduce the reader to the theory associated with the transverse dynamics of single particle, in circular accelerators. The discussion begins with a review of Hamiltonian dynamics and canonical transformations. The case of a single particle in a circular accelerator is considered with a discussion of non-linear terms and chromaticity. The canonical perturbation theory is presented and nonlinear resonances are considered. Finally, the concept of renormalization and residue criterion are examined. (FI)

Loading Mode and Environment Effects on Surface Profile Characteristics of Martensite Plates in Cu-Based SMAs

Science.gov (United States)

Suru, Marius-Gabriel; Paraschiv, Adrian-Liviu; Lohan, Nicoleta Monica; Pricop, Bogdan; Ozkal, Burak; Bujoreanu, Leandru-Gheorghe

2014-07-01

The present work reports the influence of the loading mode provided during training under constant stress, in bending, applied to lamellar specimens of Cu-Zn-Al shape memory alloys (SMAs). During training, the specimens were bent by a load fastened at their free end, while being martensitic at room temperature and they lifted the load by one-way effect (1WE), during heating up to austenitic field. On cooling to martensite field, the lower concave surface of bent specimens was compressed, and during heating it was elongated, being subjected to a series of tension-compression cycles, during heating-cooling, respectively. Conversely, the upper convex surface of bent specimens was elongated during cooling and compressed during heating, being subjected to compression-tension cycles. Furthermore, 2WE-trained actuators were tested by means of a hydraulic installation where, this time heating-cooling cycles were performed in oil conditions. Considering that the lower concave surface of the specimens was kept in compressed state, while the upper convex surface was kept in elongated state, the study reveals the influence of the two loading modes and environments on the width of martensite plates of the specimens trained under various numbers of cycles. In this purpose, Cu-Zn-Al specimens, trained under 100-300-500 cycles, were prepared and analyzed by atomic force microscopy (AFM) as well as optical and scanning electron microscopy (OM and SEM, respectively). The analysis also included AFM micrographs corroborated with statistical evaluations in order to reveal the effects of loading mode (tension or compression) in different environmental conditions of the specimens, on the surface profile characteristics of martensite plates, revealed by electropolishing.

Visualization of the contact line during the water exit of flat plates

Science.gov (United States)

Tassin, A.; Breton, T.; Forest, B.; Ohana, J.; Chalony, S.; Le Roux, D.; Tancray, A.

2017-08-01

We investigate experimentally the time evolution of the wetted surface during the lifting of a body initially floating at the water surface. This phenomenon is referred to as the water exit problem. The water exit experiments were conducted with transparent (PMMA) mock-ups of two different shapes: a circular disc and a square flat plate. Two different lighting systems were used to diffuse light in the mock-up material: a central high-power LED light normal to the surface and an edge-lighting system featuring an array of LED lights. These setups make it possible to illuminate the contact line, which delimits the surface of contact between the mock-up and the water. The characteristic size of the mock-ups is about 20 cm and the acceleration of the mock-up oscillates between 0 and 25 m/s^2. We show that the central light setup gives satisfactory results for the circular disc and that the edge lighting technique makes it possible to follow a contact line with a time-evolving complex shape (strong changes of convexity) up to 1000 fps. The observations presented in the paper support the possibility of extending this promising technique to more general three-dimensional bodies with arbitrary motion (e.g., including pitch motion).

Ductile Tearing of Thin Aluminum Plates Under Blast Loading. Predictions with Fully Coupled Models and Biaxial Material Response Characterization

Energy Technology Data Exchange (ETDEWEB)

Corona, Edmundo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gullerud, Arne S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Haulenbeek, Kimberly K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Reu, Phillip L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-06-01

The work presented in this report concerns the response and failure of thin 2024- T3 aluminum alloy circular plates to a blast load produced by the detonation of a nearby spherical charge. The plates were fully clamped around the circumference and the explosive charge was located centrally with respect to the plate. The principal objective was to conduct a numerical model validation study by comparing the results of predictions to experimental measurements of plate deformation and failure for charges with masses in the vicinity of the threshold between no tearing and tearing of the plates. Stereo digital image correlation data was acquired for all tests to measure the deflection and strains in the plates. The size of the virtual strain gage in the measurements, however, was relatively large, so the strain measurements have to be interpreted accordingly as lower bounds of the actual strains in the plate and of the severity of the strain gradients. A fully coupled interaction model between the blast and the deflection of the structure was considered. The results of the validation exercise indicated that the model predicted the deflection of the plates reasonably accurately as well as the distribution of strain on the plate. The estimation of the threshold charge based on a critical value of equivalent plastic strain measured in a bulge test, however, was not accurate. This in spite of efforts to determine the failure strain of the aluminum sheet under biaxial stress conditions. Further work is needed to be able to predict plate tearing with some degree of confidence. Given the current technology, at least one test under the actual blast conditions where the plate tears is needed to calibrate the value of equivalent plastic strain when failure occurs in the numerical model. Once that has been determined, the question of the explosive mass value at the threshold could be addressed with more confidence.

Bistatic Radar Cross Section of a Perfectly Conducting Rhombus-Shaped Flat Plate

Science.gov (United States)

1990-05-02

Monostatic scattering from square and circular flate plates is treated thoroughly in [1-3]. A physical optics formulation for the bistatic scattering of...7ESP13900 2 12X1*4*0.’.. MAO, (O5/M**2) oss-1’ ESP13k10 3 SX,.-00se.’ PHASE (DEC) *.....’../ EPP13920 4 2X,’F(t0Z)’.4X,’STTV,4X,’SPPM’,4X,’ STPM ’,4X,’SPTM...SCSP,SCST,SPPM,SPTrI, STPM ,STTN,fltAGE.ICN,NDNPLT) ESP14780 CALL SORTUN(1AIB,11,?2.13,NWR,t4 ,A,CGD.SOD,F)I2.D, ESP14190 & IWR1, IIISCT,ZTF,ZT,!IPLICC

Nearest Neighbor Estimates of Entropy for Multivariate Circular Distributions

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Neeraj Misra

2010-05-01

Full Text Available In molecular sciences, the estimation of entropies of molecules is important for the understanding of many chemical and biological processes. Motivated by these applications, we consider the problem of estimating the entropies of circular random vectors and introduce non-parametric estimators based on circular distances between n sample points and their k th nearest neighbors (NN, where k (≤ n – 1 is a fixed positive integer. The proposed NN estimators are based on two different circular distances, and are proven to be asymptotically unbiased and consistent. The performance of one of the circular-distance estimators is investigated and compared with that of the already established Euclidean-distance NN estimator using Monte Carlo samples from an analytic distribution of six circular variables of an exactly known entropy and a large sample of seven internal-rotation angles in the molecule of tartaric acid, obtained by a realistic molecular-dynamics simulation.

Administrative Circular No. 26 (Rev.10) - Recognition of merit

CERN Multimedia

2014-01-01

Administrative Circular No. 26 (Rev. 10) entitled “Recognition of Merit”, approved by the Director-General following discussion at the Standing Concertation Committee meeting of 5 December 2013 and entering into force on 1 January 2014, is available on the intranet site of the Human Resources Department (see here).   This circular is applicable to staff members. It cancels and replaces Administrative Circular No. 26 (Rev. 9) entitled “Recognition of Merit” of December 2011. The circular was revised in order to take into account the work performed in the framework of an elective mandate during the exercise of merit recognition of staff members. In addition, the circular was revised to provide that, in the case of staff members on special leave for professional reasons for a period equal to or longer than half a year, it will no longer be possible to grant an exceptional advancement. Department Head Office HR Department

Global stability analysis of axisymmetric boundary layer over a circular cylinder

Science.gov (United States)

Bhoraniya, Ramesh; Vinod, Narayanan

2018-05-01

This paper presents a linear global stability analysis of the incompressible axisymmetric boundary layer on a circular cylinder. The base flow is parallel to the axis of the cylinder at inflow boundary. The pressure gradient is zero in the streamwise direction. The base flow velocity profile is fully non-parallel and non-similar in nature. The boundary layer grows continuously in the spatial directions. Linearized Navier-Stokes (LNS) equations are derived for the disturbance flow quantities in the cylindrical polar coordinates. The LNS equations along with homogeneous boundary conditions forms a generalized eigenvalues problem. Since the base flow is axisymmetric, the disturbances are periodic in azimuthal direction. Chebyshev spectral collocation method and Arnoldi's iterative algorithm is used for the solution of the general eigenvalues problem. The global temporal modes are computed for the range of Reynolds numbers and different azimuthal wave numbers. The largest imaginary part of the computed eigenmodes is negative, and hence, the flow is temporally stable. The spatial structure of the eigenmodes shows that the disturbance amplitudes grow in size and magnitude while they are moving towards downstream. The global modes of axisymmetric boundary layer are more stable than that of 2D flat-plate boundary layer at low Reynolds number. However, at higher Reynolds number they approach 2D flat-plate boundary layer. Thus, the damping effect of transverse curvature is significant at low Reynolds number. The wave-like nature of the disturbance amplitudes is found in the streamwise direction for the least stable eigenmodes.

Paper microzone plates.

Science.gov (United States)

Carrilho, Emanuel; Phillips, Scott T; Vella, Sarah J; Martinez, Andres W; Whitesides, George M

2009-08-01

This paper describes 96- and 384-microzone plates fabricated in paper as alternatives to conventional multiwell plates fabricated in molded polymers. Paper-based plates are functionally related to plastic well plates, but they offer new capabilities. For example, paper-microzone plates are thin (approximately 180 microm), require small volumes of sample (5 microL per zone), and can be manufactured from inexpensive materials ($0.05 per plate). The paper-based plates are fabricated by patterning sheets of paper, using photolithography, into hydrophilic zones surrounded by hydrophobic polymeric barriers. This photolithography used an inexpensive formulation photoresist that allows rapid (approximately 15 min) prototyping of paper-based plates. These plates are compatible with conventional microplate readers for quantitative absorbance and fluorescence measurements. The limit of detection per zone loaded for fluorescence was 125 fmol for fluorescein isothiocyanate-labeled bovine serum albumin, and this level corresponds to 0.02 the quantity of analyte per well used to achieve comparable signal-to-noise in a 96-well plastic plate (using a solution of 25 nM labeled protein). The limits of detection for absorbance on paper was approximately 50 pmol per zone for both Coomassie Brilliant Blue and Amaranth dyes; these values were 0.4 that required for the plastic plate. Demonstration of quantitative colorimetric correlations using a scanner or camera to image the zones and to measure the intensity of color, makes it possible to conduct assays without a microplate reader.

Crack displacement sensing and measurement in concrete using circular grating moire fringes and pattern matching

Science.gov (United States)

Chan, H. M.; Yen, K. S.; Ratnam, M. M.

2008-09-01

The moire method has been extensively studied in the past and applied in various engineering applications. Several techniques are available for generating the moire fringes in these applications, which include moire interferometry, projection moire, shadow moire, moire deflectometry etc. Most of these methods use the superposition of linear gratings to generate the moire patterns. The use of non-linear gratings, such as circular, radial and elongated gratings has received less attention from the research community. The potential of non-linear gratings in engineering measurement has been realized in a limited number of applications, such as rotation measurement, measurement of linear displacement, measurement of expansion coefficients of materials and measurement of strain distribution. In this work, circular gratings of different pitch were applied to the sensing and measurement of crack displacement in concrete structures. Gratings of pitch 0.50 mm and 0.55 mm were generated using computer software and attached to two overlapping acrylic plates that were bonded to either side of the crack. The resulting moire patterns were captured using a standard digital camera and compared with a set of reference patterns generated using a precision positioning stage. Using several image pre-processing stages, such as filtering and morphological operations, and pattern matching the magnitude displacements along two orthogonal axes can be detected with a resolution of 0.05 mm.

Propagation and radiation characteristics of the circular electric, circular magnetic and hybrid waveguide modes

International Nuclear Information System (INIS)

Crenn, J.P.

1996-06-01

The field distributions and propagation constants of the circular electric, circular magnetic and hybrid modes of oversized waveguides are expressed, taking the effects of walls into account. The near and far field patterns are derived in the case of real wall functions. It is shown that, for very oversized waveguides, the terms containing wall functions can be ignored in the calculations, and it results that the expressions of fields and propagation constants become independent of the types of waveguides. An application to corrugated waveguides for Electron Cyclotron Resonance Heating experiments shows the variations of the radiation characteristics versus geometric parameters of the corrugations and determines the ranges of interest for these parameters. (author)

Administrative Circular No. 23 (Rev. 4) - Special working hours

CERN Document Server

Department Head Office - HR Department

2016-01-01

Administrative Circular No. 23 (Rev. 4) entitled "Special working hours", approved by the Director-General following discussion in the Standing Concertation Committee meeting on 22 March 2016, will be available on 1st September 2016 via the following link: https://cds.cern.ch/record/2208539.   This revised circular cancels and replaces Administrative Circular No. 23 (Rev. 3) also entitled "Special working hours" of January 2013. This document contains modifications to reflect the new career structure and ensuring the provision consistent with practice that compensation or remuneration of special working hours performed remotely is possible only in case of emergency.   This circular will enter into force on 1st September 2016.

Shear strength of reinforced concrete circular cross-section beams

Directory of Open Access Journals (Sweden)

P. W. G. N. Teixeira

Full Text Available A proposed adequation of NBR 6118, Item 7.4, related to shear strength of reinforced concrete beams is presented with aims to application on circular cross-section. The actual expressions are most suitable to rectangular cross-section and some misleading occurs when applied to circular sections at determination of VRd2, Vc and Vsw, as consequence of bw (beam width and d (effective depth definitions as well as the real effectiveness of circular stirrups. The proposed adequation is based on extensive bibliographic review and practical experience with a great number of infrastructure elements, such as anchored retaining pile walls, where the use of circular reinforced concrete members is frequent.

An evaluation of ACI 349 code for design of the fastening system at nuclear power plant

International Nuclear Information System (INIS)

Jang, J.-B.; Suh, Y.-P.; Lee, J.-R.

2005-01-01

ACI 349 Code, revised on 2001, is only available for the anchor with diameter not exceeding 2 in. and tensile embedment not exceeding 25 in. in depth. So, ACI 349 Code can't be applied to the design of the large sized anchor with diameter exceeding 2 in. and tensile embedment exceeding 25 in. in depth which fastens the SG, RV, RCP, PZR, etc. at containment building. Therefore, an application of ACI 349 Code was investigated for the design of the small and large sized anchors under tensile load using the numerical analysis model which was developed on a basis of the various test data of cast-in-place anchor in this study. In conclusion, it is proved that ACI 349 Code is available for the design of the small and large sized cast-in-place anchor. (authors)

Advances in moment transfering dvw reinforced timber connections : analysis and experimental verification, Part 1

NARCIS (Netherlands)

Leijten, A.J.M.; Brandon, D.

2013-01-01

Considerable advances in the moment transferring capacity of timber connections are achieved by using densified veneer wood reinforcement and expanded tube fasteners. This study focuses on the rotational stiffness of two dvw reinforced connections joined in series by a steel plate in a splice and

Modeling of circular-grating surface-emitting lasers

Science.gov (United States)

Shams-Zadeh-Amiri, Ali M.

Grating-coupled surface-emitting lasers became an area of growing interest due to their salient features. Emission from a broad area normal to the wafer surface, makes them very well suited in high power applications and two- dimensional laser arrays. These new possibilities have caused an interest in different geometries to fully develop their potential. Among them, circular-grating lasers have the additional advantage of producing a narrow beam with a circular cross section. This special feature makes them ideal for coupling to optical fibers. All existing theoretical models dealing with circular- grating lasers only consider first-order gratings, or second-order gratings, neglecting surface emission. In this thesis, the emphasis is to develop accurate models describing the laser performance by considering the radiation field. Toward this aim, and due to the importance of the radiation modes in surface-emitting structures, a theoretical study of these modes in multilayer planar structures has been done in a rigorous and systematic fashion. Problems like orthogonality of the radiation modes have been treated very accurately. We have considered the inner product of radiation modes using the distribution theory. Orthogonality of degenerate radiation modes is an important issue. We have examined its validity using the transfer matrix method. It has been shown that orthogonality of degenerate radiation modes in a very special case leads to the Brewster theorem. In addition, simple analytical formulas for the normalization of radiation modes have been derived. We have shown that radiation modes can be handled in a much easier way than has been thought before. A closed-form spectral dyadic Green's function formulation of multilayer planar structures has been developed. In this formulation, both rectangular and cylindrical structures can be treated within the same mathematical framework. The Hankel transform of some auxiliary functions defined on a circular aperture has

Molecular photoelectron holography with circularly polarized laser pulses.

Science.gov (United States)

Yang, Weifeng; Sheng, Zhihao; Feng, Xingpan; Wu, Miaoli; Chen, Zhangjin; Song, Xiaohong

2014-02-10

We investigate the photoelectron momentum distribution of molecular-ion H2+driven by ultrashort intense circularly polarized laser pulses. Both numerical solutions of the time-dependent Schrödinger equation (TDSE) and a quasiclassical model indicate that the photoelectron holography (PH) with circularly polarized pulses can occur in molecule. It is demonstrated that the interference between the direct electron wave and rescattered electron wave from one core to its neighboring core induces the PH. Moreover, the results of the TDSE predict that there is a tilt angle between the interference pattern of the PH and the direction perpendicular to the molecular axis. Furthermore, the tilt angle is sensitively dependent on the wavelength of the driven circularly polarized pulse, which is confirmed by the quasiclassical calculations. The PH induced by circularly polarized laser pulses provides a tool to resolve the electron dynamics and explore the spatial information of molecular structures.

Low-Cost and High-Gain SIW Circularly Polarized Circular-Horn-Loaded Antenna for Broadband Millimeter-Wave Applications

Directory of Open Access Journals (Sweden)

Ming Du

2017-09-01

Full Text Available A wideband, low-cost and high-gain circularly polarized (CP circular-horn-loaded antenna based on substrate integrated waveguide (SIW technology operating at Ka band is presented. The proposed antenna, which is built on a single-layer substrate, consists of five parts: a short-ended SIW, a centro-symmetric wide slot, an L-shaped probe, a circular horn and a transition from SIW to air-filled rectangular waveguide for measurement. The slot is etched on the upper ground of the SIW, while the L-shaped probe for generating CP wave is printed inside the slot and connected to the SIW. A circular horn is also loaded on the surface of the SIW slot for high gain. Then, the proposed antenna with a dimension of 45×45×24.16 mm3 was fabricated and measured. The measured results show that the antenna has a wide impedance matching bandwidth of 28.6% from 30 to 40 GHz for |S11| ≤10 dB and a wide axial ratio (AR bandwidth of 22.8% from 31.5 to 39.6 GHz for AR ≤ 3 dB. The measured maximum gain is 15.6 dBi at 36 GHz with slight fluctuations over the 30–40-GHz frequency range. This kind of antenna merits low cost and easy integration with common differential circuits at the same time.

System for circular and complex tomography

International Nuclear Information System (INIS)

Hellstrom, M.J.

1979-01-01

This invention discloses a system for conducting circular as well as complex tomographic procedures utilizing apparatus which has no mechanical linkage between the X-ray source and the X-ray receptor. The path of travel of the X-ray source both circularly and linearly is sensed by electromagnetic radiation and more particularly by light radiation which is generated by a laser. The linear travel is sensed by means of reflected laser radiation directed to the X-ray source and fed to an interferometer. The circular travel, on the other hand, is sensed by means of a laser gyroscope also receiving light radiation from a laser. Optical energy sensing means is thus used to generate command signals which are coupled to respective drive motors which act to rotate and when desirable, translate the X-ray receptor so that its motion follows the motion, both orbital and linear, of the X-ray source for performing any desired type of tomographic procedure

Circular economy and waste to energy

Science.gov (United States)

Rada, E. C.; Ragazzi, M.; Torretta, V.; Castagna, G.; Adami, L.; Cioca, L. I.

2018-05-01

Waste management in European Union has long being regulated by the 4Rs principle, i.e. reduction, reuse, recycling, recovery, with landfill disposal as the last option. This vision recently led the European Union (especially since 2015) to the introduction of virtuous goals based on the rejection of linear economy in favour of circular economy strongly founded on materials recovery. In this scenario, landfill disposal option will disappear, while energy recovery may appear controversial when not applied to biogas production from anaerobic digestion. The present work aims to analyse the effects that circular economy principles introduced in the European Union context will have on the thermochemical waste treatment plants design. Results demonstrate that indirect combustion (gasification + combustion) along with integrated vitrification of the non-combustible fraction of treated waste will have a more relevant role in the field of waste treatment than in the past, thanks to the compliance of this option with the principles of circular economy.

Advisory Circular checklist and status of other FAA publications

Science.gov (United States)

1997-08-15

This 1997 circular transmits the revised checklist of the Federal Aviation : Administration's (FAA) Advisory Circulars (AC's). It also lists certain other : FAA publications sold by the Superintendent of Documents.

Flexible Multi-Body Spacecraft Simulator: Design, Construction, and Experiments

Science.gov (United States)

2017-12-01

required analysis. The first step in applying Pontryagin’s Principle is writing the control Hamiltonian: ( , , , ) ( , , ) ( , , )TH x u t F x u t f...of holes allows the adapter plate to be fastened to the MBSS top plate. 26 The base and link are designed to be modular and expandable. The link...https://www.quanser.com/products/2-dof-serial-flexible-joint/ 79 INITIAL DISTRIBUTION LIST 1. Defense Technical Information Center Ft. Belvoir

Circular RNAs

DEFF Research Database (Denmark)

Han, Yi-Neng; Xia, Shengqiang; Zhang, Yuan-Yuan

2017-01-01

Circular RNAs (circRNAs) are a novel type of universal and diverse endogenous noncoding RNAs (ncRNAs) and they form a covalently closed continuous loop without 5' or 3' tails unlike linear RNAs. Most circRNAs are presented with characteristics of abundance, stability, conservatism, and often exhi...... and expression regulators, RBP sponges in cancer as well as current research methods of circRNAs, providing evidence for the significance of circRNAs in cancer diagnosis and clinical treatment....

Circular fringe projection profilometry.

Science.gov (United States)

Zhao, Hong; Zhang, Chunwei; Zhou, Changquan; Jiang, Kejian; Fang, Meiqi

2016-11-01

In this Letter, a novel three-dimensional (3D) measurement method, called the circular fringe projection profilometry (CFPP), is proposed. Similar to the conventional fringe projection profilometry, CFPP also requires fringe pattern projection and capture, phase demodulation, and phase unwrapping. However, it works with a totally different mechanism. CFPP recovers the height of a point by calculating its distance to the optical center of a projector along the optical axis. This distance is calculated with the aid of the divergence angle of a projected light ray and the distance between the measured point and the optical axis. The distance between the measured point and the optical axis is detected by a camera with telecentric lenses, while the divergence angle can be calculated from the phase of a captured circular fringe pattern. The validity of CFPP is confirmed by a set of experiments.

Effect of length to thickness ratio on free vibration analysis of thick fiber reinforced plastic skew cross-ply laminate with circular cutout

Science.gov (United States)

Srividya, K.; Reddy, Ch. Kishore; Sumanth, Ch. Mohan; Krishnaiah, P. Gopala; Kishan, V. Mallikharjuna

2018-04-01

The present investigation deals with the free vibration analysis of a thick four-layered symmetric cross-ply skew laminated composite plate with a circular cutout. Three dimensional finite element models (FEM) which use the elasticity theory for the determination of stiffness matrices are modeled in ANSYS software to evaluate first five natural frequencies of the laminate. The variations of the first five natural frequencies with respect to length to thickness ratio (S) for different diameter to length ratios (d/l) are presented. It is observed that, the natural frequencies decreases with increase of thickness ratio(S).

Experimental investigation of complex circular Airy beam characteristics

Science.gov (United States)

Porfirev, A. P.; Fomchenkov, S. A.; Khonina, S. N.

2018-04-01

We demonstrate a new type of circular Airy beams, the so-called azimuthally modulated circular Airy beams, generated by utilizing a diffraction element, whose transmission function is the sum of the transmission function of the element generating a "petal" pattern and the transmission function of the element generating a circular Airy beam. We experimentally investigate the propagation dynamics of such beams and demonstrate that their autofocusing and selfhealing properties are strongly dependent on the number of generated petals. These beams are a combination of a conventional circular Airy beam and vortex laser beams (or their superpositions). Using a spatial light modulator, we demonstrate that these beams have unique properties such as autofocusing, "nondiffractive" propagation and self-healing after passing through an obstacle. The experimental results are in good agreement with the simulation. We believe that these results can be very useful for lensless laser fabrication and laser manipulation techniques, as well as for development of new filament plasma multi-channel formation methods.

12 CFR 563g.8 - Use of the offering circular.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Use of the offering circular. 563g.8 Section 563g.8 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY SECURITIES OFFERINGS § 563g.8 Use of the offering circular. (a) An offering circular or amendment declared effective by the...

Locking screw-plate interface stability in carbon-fibre reinforced polyetheretherketone proximal humerus plates.

Science.gov (United States)

Hak, David J; Fader, Ryan; Baldini, Todd; Chadayammuri, Vivek B S

2017-09-01

Carbon-fibre reinforced polyetheretherketone (CFR-PEEK) plates have recently been introduced for proximal humerus fracture treatment. The purpose of this study was to compare the locking screw-plate interface stability in CFR-PEEK versus stainless steel (SS) proximal humerus plates. Locking screw mechanical stability was evaluated independently in proximal and shaft plate holes. Stiffness and load to failure were tested for three conditions: (1) on-axis locking screw insertion in CFR-PEEK versus SS plates, (2) on-axis locking screw insertion, removal, and reinsertion in CFR-PEEK plates, and (3) 10-degree off-axis locking screw insertion in CFR-PEEK plates. Cantilever bending at a rate of 1 mm/minute was produced by an Instron machine and load-displacement data recorded. Shaft locking screw load to failure was significantly greater in CFR-PEEK plates compared to SS plates (746.4 ± 89.7 N versus 596.5 ± 32.6 N, p PEEK plates (p PEEK plates. The mechanical stability of locking screws in CFR-PEEK plates is comparable or superior to locking screws in SS plates.

Voltage-current characteristics of a pin-plate system with different plate configurations

International Nuclear Information System (INIS)

Feng, Zhuangbo; Long, Zhengwei

2013-01-01

In this paper, the voltage-current (V-I) characteristics of a pin-plate system with four types of collection plate configurations are studied experimentally. The collection plates consider a single metal plate, a metal plate with a fly ash cake layer, a metal plate with a clean filter media and a metal plate with a dirty filter media. The results show that the clean filter media has no obvious effect on the V-I characteristics. But the dirty filter media reduces the current density because of its high resistance. The thick fly ash cake layer increase current density because of the anti-corona effect but the increment is not very obvious.

RC Beams Strengthened with Mechanically Fastened Composites: Experimental Results and Numerical Modeling

Directory of Open Access Journals (Sweden)

Enzo Martinelli

2014-03-01

Full Text Available The use of mechanically-fastened fiber-reinforced polymer (MF-FRP systems has recently emerged as a competitive solution for the flexural strengthening of reinforced concrete (RC beams and slabs. An overview of the experimental research has proven the effectiveness and the potentiality of the MF-FRP technique which is particularly suitable for emergency repairs or when the speed of installation and immediacy of use are imperative. A finite-element (FE model has been recently developed by the authors with the aim to simulate the behavior of RC beams strengthened in bending by MF-FRP laminates; such a model has also been validated by using a wide experimental database collected from the literature. By following the previous study, the FE model and the assembled database are considered herein with the aim of better exploring the influence of some specific aspects on the structural response of MF-FRP strengthened members, such as the bearing stress-slip relationship assumed for the FRP-concrete interface, the stress-strain law considered for reinforcing steel rebars and the cracking process in RC members resulting in the well-known tension stiffening effect. The considerations drawn from this study will be useful to researchers for the calibration of criteria and design rules for strengthening RC beams through MF-FRP laminates.

Swarm Robotics with Circular Formation Motion Including Obstacles Avoidance

Directory of Open Access Journals (Sweden)

Nabil M. Hewahi

2017-07-01

Full Text Available The robots science has been developed over the past few years, where robots have become used to accomplish difficult, repetitive or accurate tasks, which are very hard for humans to carry out. In this paper, we propose an algorithm to control the motion of a swarm of robots and make them able to avoid obstacles. The proposed solution is based on forming the robots in circular fashion. A group set of robots consists of multiple groups of robots, each group of robots consists of robots forming a circular shape and each group set is a circular form of robots. The proposed algorithm is concerned with first locating the randomly generated robots in groups and secondly with the swarm robot motion and finally with the swarm obstacle avoidance and swarm reorganization after crossing the obstacle. The proposed algorithm has been simulated with five different obstacles with various numbers of randomly generated robots. The results show that the swarm in the circular form can deal with the obstacles very effectively by passing the obstacles smoothly. The proposed algorithm has been compared with flocking algorithm and it is shown that the circular formation algorithm does not need extensive computation after obstacle avoidance whereas the flocking algorithm needs extensive computation. In addition, the circular formation algorithm maintains every robot in its group after avoiding the obstacles whereas with flocking algorithm does not.

FUCHS—towards full circular RNA characterization using RNAseq

Directory of Open Access Journals (Sweden)

Franziska Metge

2017-02-01

Full Text Available Circular RNAs (circRNAs belong to a recently re-discovered species of RNA that emerge during RNA maturation through a process called back-splicing. A downstream 5′ splice site is linked to an upstream 3′ splice site to form a circular transcript instead of a canonical linear transcript. Recent advances in next-generation sequencing (NGS have brought circRNAs back into the focus of many scientists. Since then, several studies reported that circRNAs are differentially expressed across tissue types and developmental stages, implying that they are actively regulated and not merely a by-product of splicing. Though functional studies have shown that some circRNAs could act as miRNA-sponges, the function of most circRNAs remains unknown. To expand our understanding of possible roles of circular RNAs, we propose a new pipeline that could fully characterizes candidate circRNA structure from RNAseq data—FUCHS: FUll CHaracterization of circular RNA using RNA-Sequencing. Currently, most computational prediction pipelines use back-spliced reads to identify circular RNAs. FUCHS extends this concept by considering all RNA-seq information from long reads (typically >150 bp to learn more about the exon coverage, the number of double break point fragments, the different circular isoforms arising from one host-gene, and the alternatively spliced exons within the same circRNA boundaries. This new knowledge will enable the user to carry out differential motif enrichment and miRNA seed analysis to determine potential regulators during circRNA biogenesis. FUCHS is an easy-to-use Python based pipeline that contributes a new aspect to the circRNA research.

Finite Element Simulation of Mechanical and Moisture-Related Stresses in Laterally Loaded Multi-Dowel Timber Connections

DEFF Research Database (Denmark)

Ormarsson, Sigurdur; Dahlblom, O.; Nygaard, M. J.

2010-01-01

Numerical simulations of stress distribution within a moment stiff timber frame corner have been performed. The frame corner is a multi-dowel connection with two slotted-in steel plates. The interaction between the fasteners and the wood material is modelled as a full contact interaction based...

A modular scanning tunneling microscope with an interchangeable elastic closed cell and external actuators

International Nuclear Information System (INIS)

Bjarnason, Elias H.; Arnalds, Unnar B.; Olafsson, Sveinn

2006-01-01

We introduce a novel modular cell based scanning tunneling microscope with external piezoelectric actuators. A tip and a sample are contained in a closed interchangeable cell, consisting of a stiff top plate and a bottom part, fastened together by an elastic material. The bottom part, containing a scanning tip, is fastened to a base unit while the top plate, containing a sample, is capable of scanning motion by external piezoelectric actuators mounted in the same base unit. The actuators are pre-loaded by the deformation of the elastic material of the cell, giving an increased stability. This design is expected to simplify the scanning tunneling microscope (STM) operation in difficult environments greatly by enclosing only the tip and sample in a small cell-module, which is pluggable to a scanning mechanism and other supportive functionalities. A frequency characterization and an image scan showing atomic resolution of highly oriented graphite in air, at room temperature, is presented

On the Recognition of Fuzzy Circular Interval Graphs

OpenAIRE

Oriolo, Gianpaolo; Pietropaoli, Ugo; Stauffer, Gautier

2011-01-01

Fuzzy circular interval graphs are a generalization of proper circular arc graphs and have been recently introduced by Chudnovsky and Seymour as a fundamental subclass of claw-free graphs. In this paper, we provide a polynomial-time algorithm for recognizing such graphs, and more importantly for building a suitable representation.

5 CFR 1310.5 - List of current circulars.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false List of current circulars. 1310.5 Section 1310.5 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES OMB CIRCULARS § 1310.5... and Use of Voluntary Consensus Standards and in Conformity Assessment Activities” A-122—“Cost...

An analysis of near-circular lunar mapping orbits

Indian Academy of Sciences (India)

Numerical investigations have been carried out to analyse the evolution of lunar circular orbits and the influence of the higher order harmonics of the lunar gravity field. The aim is to select the appropriate near-circular orbit characteristics, which extend orbit life through passive orbit maintenance. The spherical harmonic ...

University Students Alternative Conceptions On Circular Motion

OpenAIRE

Ian Phil Canlas

2015-01-01

This study attempted to find out university students alternative conceptions on circular motion. An 18-item researcher-compiled and content-validated questionnaire was administered to twenty-six 26 students taking up a program in Bachelor in Secondary Education-Physical Science in their second year enrolled in a course on mechanics. Results revealed that majority of the students possess alternative conceptions on circular motion specifically along velocity acceleration and force. Moreover res...

The study of evaluation index system on construction enterprise’s circular economy

Science.gov (United States)

Yi, Lu; Liu, Zhigang

2017-06-01

The development of circular economy is an important way to judge quality of enterprise development and to realize the sustainable development of enterprises. This paper will combine the characteristics of the development of circular economy in construction enterprise to construct circular economy evaluation index system. Then it uses fuzzy mathematics theory and hierarchical analysis evaluation method for comprehensive evaluation of circular economy development level. Through the empirical analysis, the paper provides the reference basis for construction enterprises to further improve the level of circular economy.

Fabrication of circular microfluidic network in enzymatically-crosslinked gelatin hydrogel

Energy Technology Data Exchange (ETDEWEB)

He, Jiankang, E-mail: jiankanghe@mail.xjtu.edu.cn; Chen, Ruomeng; Lu, Yongjie; Zhan, Li; Liu, Yaxiong; Li, Dichen; Jin, Zhongmin

2016-02-01

It is a huge challenge to engineer vascular networks in vital organ tissue engineering. Although the incorporation of artificial microfluidic network into thick tissue-engineered constructs has shown great promise, most of the existing microfluidic strategies are limited to generate rectangle cross-sectional channels rather than circular vessels in soft hydrogels. Here we present a facile approach to fabricate branched microfluidic network with circular cross-sections in gelatin hydrogels by combining micromolding and enzymatically-crosslinking mechanism. Partially crosslinked hydrogel slides with predefined semi-circular channels were molded, assembled and in situ fully crosslinked to form a seamless and circular microfluidic network. The bonding strength of the resultant gelatin hydrogels was investigated. The morphology and the dimension of the resultant circular channels were characterized using scanning electron microscopy (SEM) and micro-computerized tomography (μCT). Computational fluid dynamic simulation shows that the fabrication error had little effect on the distribution of flow field but affected the maximum velocity in comparison with designed models. The microfluidic gelatin hydrogel facilitates the attachment and spreading of human umbilical endothelial cells (HUVECs) to form a uniform endothelialized layer around the circular channel surface, which successfully exhibited barrier functions. The presented method might provide a simple way to fabricate circular microfluidic networks in biologically-relevant hydrogels to advance various applications of in vitro tissue models, organ-on-a-chip systems and tissue engineering. - Highlights: • A facile method was proposed to build a circular fluidic network in gelatin hydrogel. • The fluidic network is mechanically robust and supports physiological flow. • HUVECs formed endothelialized layer around the channel to express barrier function.

Circular Business Models: Defining a Concept and Framing an Emerging Research Field

Directory of Open Access Journals (Sweden)

Julia L. K. Nußholz

2017-10-01

Full Text Available To aid companies in transitioning towards a circular economy and adopting strategies such as reuse, repair, and remanufacturing, the concept of circular business models has been developed. Although the concept draws on contributions from various academic disciplines, and despite its increasingly frequent use, few scholars clearly define what a circular business model is. Understanding about what makes a business model circular is diverse, hampering the theoretical development and practical application of circular business models. This study aims to help frame the field of circular business model research, by clarifying the fundamentals of the concept from the perspectives of resource efficiency and business model innovation. Expanding on these findings, a review of how the concept is used in recent academic literature is provided. It shows that a coherent view is lacking on which resource efficiency strategies classify a business model as circular. This study clarifies which resource efficiency strategies can be deemed as relevant key strategies for circular business models, and suggests a new definition of the concept. With the definition grounded in analysis of the fundamentals in terms of resource efficiency and business models, the study contributes to theoretical advancement and effective implementation of circular business models.

12 CFR 563g.2 - Offering circular requirement.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Offering circular requirement. 563g.2 Section 563g.2 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY SECURITIES OFFERINGS § 563g.2 Offering circular requirement. (a) General. No savings association shall offer or sell, directly...

Band vs. Circular Sawmills: Relative Labor & Maintenance Costs

Science.gov (United States)

Philip H. Steele; Philip A. Araman

1997-01-01

Substantial sawmill lumber yield increases from kerf and sawing variation reductions can be realized by employing band rather than circular headrigs. Softwood sawmills rapidly adopted bandsaw headrig technology to the extent that it is currently unusual to find circular saw headrigs in a softwood sawmill. Hardwood sawmills, faced with a different economic situation,...

How can design science contribute to a circular economy?

DEFF Research Database (Denmark)

Pigosso, Daniela Cristina Antelmi; McAloone, Tim C.

2017-01-01

Circular Economy is increasingly seen as a key approach to operationalising goals and supporting the transition to a sustainable society by enhancing competitiveness and economic growth. Creating a Circular Economy requires fundamental changes throughout the value chain, from innovation, product...... design and production processes all the way to end of life, new business models and consumption patterns. This paper explores how design science can support the transition from the traditional linear 'take-make-consume-dispose' approach, to a Circular Economy. By means of a systematic literature review...

Calibration of circular aperture area using vision probe at inmetro

Directory of Open Access Journals (Sweden)

Costa Pedro Bastos

2016-01-01

Full Text Available Circular aperture areas are standards of high importance for the realization of photometric and radiometric measurements, where the accuracy of these measures is related to the accuracy of the circular aperture area calibrations. In order to attend the requirement for traceability was developed in Brazilian metrology institute, a methodology for circular aperture area measurement as requirements from the radiometric and photometric measurements. In the developed methodology apertures are measured by non-contact measurement through images of the aperture edges captured by a camera. These images are processed using computer vision techniques and then the values of the circular aperture area are determined.

¿Son diferentes los migrantes circulares? La integración, el bienestar y la intención de quedarse de los que migran por primera vez y de los migrantes circulares (Are circular migrants different? Integration, wellbeing, and intention to stay of first-time and circular migrants

Directory of Open Access Journals (Sweden)

Michael Braun

2010-12-01

Full Text Available ResumenCon datos tomados del proyecto PIONEUR sobre la migración interna en la Unión Europea, definiremos (una forma débil de migrantes circulares como el colectivo de aquellos migrantes que ya habían experimentado una estancia prolongada en el país de residencia (en lo sucesivo abreviado a PDR antes de su traslado definitivo. A continuación, se ofrecerá una descripción de este colectivo junto con sus características sociodemográficas y se emplearán análisis de regresión (multinivel para determinar si la migración circular explica las diferencias en algunas variables dependientes (como el dominio del idioma, el apego al PDR que arrojan esos migrantes teniendo en cuenta las características sociodemográficas. De este modo, la migración circular estaría relacionada con un mayor contacto con la cultura del PDR y con una decisión consciente de regresar al país.AbstractUsing data from the PIONEUR project on intra-European migration, (a weak form of circular migrants will be defined by the group of migrants who experienced a prolonged sojourn in the country of residence (in the following abbreviated as CoR already before the final move. Then this group will be described along socio-demographic characteristics and (multilevel regression analysis will be used to determine whether circular migration explains differences in some outcome variables (such as language proficiency, attachment to the CoR, net of the socio-demographic characteristics these migrants have. Circular migration would then be related to additional exposure to the culture of the CoR and a conscious decision to re-enter the country.

Effect of Temperature on Topological States of Circular DNA

Science.gov (United States)

Fan, Yang-Tao; Li, Xiu-Yan; Liu, Yan-Hui; Chen, Hu

2017-07-01

The different topological states of circular double-stranded DNA can be defined by their linking number. The equilibrium distribution of linking number can be obtained by circularizing a linear DNA into a circle by ligase. Based on the recent experimental results that the DNA bending rigidity and twist rigidity strongly depend on temperature, the reduced bending rigidity can be approximated by g=(3.19× {10}-19-T\\cdot 4.14× {10}-22) {erg}\\cdot {cm} over the temperature interval (5 ∼ 53) °C, and the temperature dependence of twist rigidity can be fitted by C(T)=(4588.89{exp} (-T/117.04)-251.33) nm. The temperature dependence of the linking number distribution of circular DNAs can be predicted by using Monte Carlo simulation. The variance of linking number distribution on temperature is in accordance with the previous experimental results. Compared with the temperature dependence of bending rigidity, the temperature dependence of twist rigidity causes a noticeable fluctuation in linking number distribution and mainly contribute towards the variance change of linking number distribution of circular DNA. The variance of the writhe number and twist number in the equation = + depends on the length of circular DNA. When the length of circular DNA is less than 230 nm, the variance of twist number is dominant over the variance of writhe number ( ), whereas for the condition that the length of the circular DNA is larger than 370 nm. Supported by the National Natural Science Foundation of China under Grant Nos. 11047022, 11204045, and 11464004, Guizhou Provincial Tracking Key Program of Social Development (SY20123089, SZ20113069), the General Financial Grant from the China Postdoctoral Science Foundation (2014M562341), the Research Foundation for Young University Teachers from Guizhou University (201311), and College Innovation Talent Team of Guizhou Province (2014)32

Breaking the Barriers to the Circular Economy

OpenAIRE

Kirchherr, J.W.; Hekkert, M.P.; Bour, Ruben; Huijbrechtse-Truijens, Anne; Kostense-Smit, Erica; Muller, Jennifer

2017-01-01

The Copernicus Institute of Sustainable Development, Utrecht University, the Netherlands and Deloitte have jointly carried out research on barriers to the Circular Economy (CE) in the European Union. For this research, a survey with 153 businesses, 55 government officials and expert interviews with forty-seven thought leaders on the circular economy from businesses, governments, academia and NGOs have been carried out. Two types of barriers emerged as main barriers Firstly, there are the cult...

Performance limits of ion extraction systems with non-circular apertures

Energy Technology Data Exchange (ETDEWEB)

Shagayda, A., E-mail: shagayda@gmail.com; Madeev, S. [Keldysh Research Centre, Onezhskaya, 8, 125438 Moscow (Russian Federation)

2016-04-15

A three-dimensional computer simulation is used to determine the perveance limitations of ion extraction systems with non-circular apertures. The objective of the study is to analyze the possibilities to improve mechanical strength of the ion optics made of carbon-carbon composite materials. Non-circular grid apertures are better suited to the physical structure of carbon-carbon composite materials, than conventionally used circular holes in a hexagonal pattern, because they allow a fewer number of cut fibers. However, the slit-type accelerating systems, usually regarded as the main alternative to the conventional ion optics, have an intolerably narrow range of operating perveance values at which there is no direct ion impingement on the acceleration grid. This paper presents results of comparative analysis of a number of different ion optical systems with non-circular apertures and conventional ion optical systems with circular apertures. It has been revealed that a relatively wide perveance range without direct ion impingement may be obtained with apertures shaped as a square with rounded corners. Numerical simulations show that this geometry may have equivalent perveance range as the traditional geometry with circular apertures while being more mechanically robust. In addition, such important characteristics, as the effective transparency for both the ions and the neutral atoms, the height of the potential barrier reflecting the downstream plasma electrons and the angular divergence of the beamlet also can be very close to these parameters for the optics with circular apertures.

Performance limits of ion extraction systems with non-circular apertures.

Science.gov (United States)

Shagayda, A; Madeev, S

2016-04-01

A three-dimensional computer simulation is used to determine the perveance limitations of ion extraction systems with non-circular apertures. The objective of the study is to analyze the possibilities to improve mechanical strength of the ion optics made of carbon-carbon composite materials. Non-circular grid apertures are better suited to the physical structure of carbon-carbon composite materials, than conventionally used circular holes in a hexagonal pattern, because they allow a fewer number of cut fibers. However, the slit-type accelerating systems, usually regarded as the main alternative to the conventional ion optics, have an intolerably narrow range of operating perveance values at which there is no direct ion impingement on the acceleration grid. This paper presents results of comparative analysis of a number of different ion optical systems with non-circular apertures and conventional ion optical systems with circular apertures. It has been revealed that a relatively wide perveance range without direct ion impingement may be obtained with apertures shaped as a square with rounded corners. Numerical simulations show that this geometry may have equivalent perveance range as the traditional geometry with circular apertures while being more mechanically robust. In addition, such important characteristics, as the effective transparency for both the ions and the neutral atoms, the height of the potential barrier reflecting the downstream plasma electrons and the angular divergence of the beamlet also can be very close to these parameters for the optics with circular apertures.

Performance limits of ion extraction systems with non-circular apertures

Science.gov (United States)

Shagayda, A.; Madeev, S.

2016-04-01

A three-dimensional computer simulation is used to determine the perveance limitations of ion extraction systems with non-circular apertures. The objective of the study is to analyze the possibilities to improve mechanical strength of the ion optics made of carbon-carbon composite materials. Non-circular grid apertures are better suited to the physical structure of carbon-carbon composite materials, than conventionally used circular holes in a hexagonal pattern, because they allow a fewer number of cut fibers. However, the slit-type accelerating systems, usually regarded as the main alternative to the conventional ion optics, have an intolerably narrow range of operating perveance values at which there is no direct ion impingement on the acceleration grid. This paper presents results of comparative analysis of a number of different ion optical systems with non-circular apertures and conventional ion optical systems with circular apertures. It has been revealed that a relatively wide perveance range without direct ion impingement may be obtained with apertures shaped as a square with rounded corners. Numerical simulations show that this geometry may have equivalent perveance range as the traditional geometry with circular apertures while being more mechanically robust. In addition, such important characteristics, as the effective transparency for both the ions and the neutral atoms, the height of the potential barrier reflecting the downstream plasma electrons and the angular divergence of the beamlet also can be very close to these parameters for the optics with circular apertures.

Performance limits of ion extraction systems with non-circular apertures

International Nuclear Information System (INIS)

Shagayda, A.; Madeev, S.

2016-01-01

A three-dimensional computer simulation is used to determine the perveance limitations of ion extraction systems with non-circular apertures. The objective of the study is to analyze the possibilities to improve mechanical strength of the ion optics made of carbon-carbon composite materials. Non-circular grid apertures are better suited to the physical structure of carbon-carbon composite materials, than conventionally used circular holes in a hexagonal pattern, because they allow a fewer number of cut fibers. However, the slit-type accelerating systems, usually regarded as the main alternative to the conventional ion optics, have an intolerably narrow range of operating perveance values at which there is no direct ion impingement on the acceleration grid. This paper presents results of comparative analysis of a number of different ion optical systems with non-circular apertures and conventional ion optical systems with circular apertures. It has been revealed that a relatively wide perveance range without direct ion impingement may be obtained with apertures shaped as a square with rounded corners. Numerical simulations show that this geometry may have equivalent perveance range as the traditional geometry with circular apertures while being more mechanically robust. In addition, such important characteristics, as the effective transparency for both the ions and the neutral atoms, the height of the potential barrier reflecting the downstream plasma electrons and the angular divergence of the beamlet also can be very close to these parameters for the optics with circular apertures.

Influence of the Metal Volume Fraction on the maximum deflection and impact load of GLARE plates subjected to low velocity impact

Science.gov (United States)

Bikakis, GSE; Savaidis, A.; Zalimidis, P.; Tsitos, S.

2016-11-01

Fiber-metal laminates are hybrid composite materials, consisting of alternating metal layers bonded to fiber-reinforced prepreg layers. GLARE (GLAss REinforced) belongs to this new family of materials. GLARE is the most successful fiber-metal laminate up to now and is currently being used for the construction of primary aerospace structures, such as the fuselage of the Airbus A380 air plane. Impact properties are very important in aerospace structures, since impact damage is caused by various sources, such as maintenance damage from dropped tools, collision between service cars or cargo and the structure, bird strikes and hail. The principal objective of this article is to evaluate the influence of the Metal Volume Fraction (MVF) on the low velocity impact response of GLARE fiber-metal laminates. Previously published differential equations of motion are employed for this purpose. The low velocity impact behavior of various circular GLARE plates is predicted and characteristic values of impact variables, which represent the impact phenomenon, are evaluated versus the corresponding MVF of the examined GLARE material grades. The considered GLARE plates are subjected to low velocity impact under identical impact conditions. A strong effect of the MVF on the maximum impact load and a significant effect on the maximum plate deflection of GLARE plates has been found.

Circular polarimetry of the magnetic compact binary AM Herculis

Energy Technology Data Exchange (ETDEWEB)

Piirola, V; Vilhu, O; Tuominen, I

1982-01-01

Circular polarimetry in the red and simultaneous photometric observations in the UBVRI bands during the period June 1 to 3, 1981, of AM Herculis are discussed. Peak value of negative circular polarization (- 15 %) is stronger than observed in 1976 to 1979. Variations in the shape of the polarization and light curves occur from night to night. Positive crossover and reversal of the sign of the circular polarization are only marginal. Long term changes in polarization may be partly due to precession of the axis of rotation of the white dwarf about the binary axis. However, the duration of the phase interval where circular polarization remains close to zero changes on a time scale of days, casting doubt on precession models. The changing shape and position of the accretion columns with respect to the magnetic axis could explain short term variations. (ESA)

Soil and land management in a circular economy.

Science.gov (United States)

Breure, A M; Lijzen, J P A; Maring, L

2018-05-15

This article elaborates the role of soil and land management in a circular economy. The circular economy is highly dependent on the functioning of soils and land for the production of food and other biomass; the storage, filtration and transformation of many substances including water, carbon, and nitrogen; the provision of fresh mineral resources and fossil fuels; and the use of their functions as the platform for nature and human activities. Resource demand is increasing as a result of the growing human population. In addition to the shrinking availability of resources resulting from their unsustainable use in the past, our planet's diminishing potential for resource production, due to a range of reasons, is leading to resource scarcity, especially in the case of depletable resources. As an economic system that focuses on maximizing the reuse of resources and products and minimizing their depreciation, the circular economy greatly influences, and depends on, soil and land management. The concise management of the resources, land and soil is thus necessary, to make a circular economy successful. Copyright © 2017 Elsevier B.V. All rights reserved.

Second-harmonic generation circular dichroism spectroscopy from tripod-like chiral molecular films

International Nuclear Information System (INIS)

Wang Xiao-Ou; Chen Li-An; Chen Li-Xue; Sun Xiu-Dong; Li Jun-Qing; Li Chun-Fei

2010-01-01

The second-harmonic generation (SHG) circular dichroism in the light of reflection from chiral films of tripod-like chiral molecules is investigated. The expressions of the second-harmonic generation circular dichroism are derived from our presented three-coupled-oscillator model for the tripod-like chiral molecules. Spectral dependence of the circular dichroism of SHG from film surface composed of tripod-like chiral molecules is simulated numerically and analysed. Influence of chiral parameters on the second-harmonic generation circular dichroism spectrum in chiral films is studied. The result shows that the second-harmonic generation circular dichroism is a sensitive method of detecting chirality compared with the ordinary circular dichroism in linear optics. All of our work indicates that the classical molecular models are very effective to explain the second-harmonic generation circular dichroism of chiral molecular system. The classical molecular model theory can give us a clear physical picture and brings us very instructive information about the link between the molecular configuration and the nonlinear processes

Numerical Analysis of Stress Concentration in Isotropic and Laminated Plates with Inclined Elliptical Holes

Science.gov (United States)

Khechai, Abdelhak; Tati, Abdelouahab; Belarbi, Mohamed Ouejdi; Guettala, Abdelhamid

2018-03-01

The design of high-performance composite structures frequently includes discontinuities to reduce the weight and fastener holes for joining. Understanding the behavior of perforated laminates is necessary for structural design. In the current work, stress concentrations taking place in laminated and isotropic plates subjected to tensile load are investigated. The stress concentrations are obtained using a recent quadrilateral finite element of four nodes with 32 DOFs. The present finite element (PE) is a combination of two finite elements. The first finite element is a linear isoparametric membrane element and the second is a high precision Hermitian element. One of the essential objectives of the current investigation is to confirm the capability and efficiency of the PE for stress determination in perforated laminates. Different geometric parameters, such as the cutout form, sizes and cutout orientations, which have a considerable effect on the stress values, are studied. Using the present finite element formulation, the obtained results are found to be in good agreement with the analytical findings, which validates the capability and the efficiency of the proposed formulation. Finally, to understand the material parameters effect such as the orientation of fibers and degree of orthotropy ratio on the stress values, many figures are presented using different ellipse major to minor axis ratio. The stress concentration values are considerably affected by increasing the orientation angle of the fibers and degree of orthotropy.

Inkjet printed circularly polarized antennas for GPS applications

KAUST Repository

Farooqui, Muhammad Fahad

2014-07-01

Two novel, inkjet printed circularly polarized antenna designs are presented for GPS applications. First antenna design comprises a planar monopole which has been made circularly polarized by the introduction of an L-shaped slit. The antenna shows a gain of 0.2 dBi at 1.575 GHz with 3-dB axial ratio bandwidth of 3.8%. The second antenna design comprises a modified monopole in the form of an inverted L and has been termed as circularly polarized inverted L antenna (CILA). The antenna shows a gain of -2 dBi at 1.575 GHz with 3-dB axial ratio bandwidth of 4.1%. Both the antenna designs are attractive for mobile applications.

Administrative Circular No. 26 (Rev. 7) – May 2007

CERN Multimedia

HR Department

2007-01-01

Recognition of Merit of Staff Members Administrative Circular No. 26 (Rev. 7) is now available on the intranet site of the Human Resources Department. This circular cancels and replaces Administrative Circular No. 26 (Rev. 6) - Procedures governing the career development of staff members. Copies will shortly be available in Departmental secretariats. If you require any additional information on the new staff-member merit assessment and recognition system, you may consult the FAQ, which has been available on the Human Resources Department intranet site since February 2007. Human Resources Department Tel. 78003

Quantitative analysis of the flexibility effect of cisplatin on circular DNA

Science.gov (United States)

Ji, Chao; Zhang, Lingyun; Wang, Peng-Ye

2013-10-01

We study the effects of cisplatin on the circular configuration of DNA using atomic force microscopy (AFM) and observe that the DNA gradually transforms to a complex configuration with an intersection and interwound structures from a circlelike structure. An algorithm is developed to extract the configuration profiles of circular DNA from AFM images and the radius of gyration is used to describe the flexibility of circular DNA. The quantitative analysis of the circular DNA demonstrates that the radius of gyration gradually decreases and two processes on the change of flexibility of circular DNA are found as the cisplatin concentration increases. Furthermore, a model is proposed and discussed to explain the mechanism for understanding the complicated interaction between DNA and cisplatin.

A Possible Differentially Shortened Strike-slip Plate Boundary: the Okhotsk Plate Example.

Science.gov (United States)

Hindle, D.; Egorov, V.; Mackey, K. G.; Fujita, K.

2004-12-01

The Okhotsk plate has been postulated based on a combination of GPS geodetic inversions (REVEL1), seimsicity, geologic and lineament data. Lying between the North American and Eurasian plates, its northwestern corner would appear to be undergoing compression in a scissors motion between the two bounding plates. Extrusion tectonics along multiple, large strike-slip faults within the Okhotsk plate itself have been suggested to allow the escape of material away from the apex of Eurasia-North America. The plate boundary between Okhotsk and North America has been suggested to be diffuse, based on widely scattered minor seismicity. However, the large, left lateral, Ulakhan fault has also been suggested as a candidate plate boundary. We present field geological and geomorphological evidence of the partitioning of deformation between the Ulakhan fault, and several parallel and oblique, linked faults. The Ulakhan fault strand appears to have a maximum displacement of 24 km based on river valley offsets and closing large pull apart basins. Some of the displacement from the Ulakhan fault appears relayed into the plate margin along oblique trending, thrust/oblique slip faults. Estimated shortening over these faults is equivalent to the amount of shortening relayed into the plate margin from the plate boundary. There may be several thrust/oblique slip faults along the Ulakhan fault, which leads to the interesting situation of a segmented, strike-slip plate boundary being actively shortened in a margin parallel direction. This may be the result of postulated extrusion of the Okhotsk plate due to North America/Eurasia convergence. Such a situation would have important consequences for the interpretation of GPS data in a plate tectonic context.

Circularly polarized luminescence of syndiotactic polystyrene

Science.gov (United States)

Rizzo, Paola; Abbate, Sergio; Longhi, Giovanna; Guerra, Gaetano

2017-11-01

Syndiotactic polystyrene (s-PS) films, when crystallized from the amorphous state by temporary sorption of non-racemic guest molecules (like carvone) not only exhibit unusually high optical activity, both in the UV-Visible and Infrared ranges, but also present circularly polarized luminescence (CPL) with high dissymmetry ratios (g = ΔI/I values in the range 0.02-0.03). Experimental evidences provide support, rather than to the usual molecular circular dichroism, to a supramolecular chiral optical response being extrinsic to the site of photon absorption and emission, possibly associated with a helical morphology of s-PS crystallites.

Magnetic field generation by circularly polarized laser light and inertial plasma confinement in a miniature 'Magnetic Bottle' induced by circularly polarized laser light

International Nuclear Information System (INIS)

Kolka, E.

1993-07-01

A new concept of hot plasma confinement in a miniature magnetic bottle induced by circularly polarized laser light is suggested in this work. Magnetic fields generated by circularly polarized laser light may be of the order of megagauss. In this configuration the circularly polarized laser light is used to get confinement of a plasma contained in a good conductor vessel. The poloidal magnetic field induced by the circularly polarized laser and the efficiency of laser absorption by the plasma are calculated in this work. The confinement in this scheme is supported by the magnetic forces and the Lawson criterion for a DT plasma might be achieved for number density n=5*10 21 cm -3 and confinement time τ= 20 nsec. The laser and the plasma parameters required to get an energetic gain are calculated. (authors)

Modified circular velocity law

Science.gov (United States)

Djeghloul, Nazim

2018-05-01

A modified circular velocity law is presented for a test body orbiting around a spherically symmetric mass. This law exhibits a distance scale parameter and allows to recover both usual Newtonian behaviour for lower distances and a constant velocity limit at large scale. Application to the Galaxy predicts the known behaviour and also leads to a galactic mass in accordance with the measured visible stellar mass so that additional dark matter inside the Galaxy can be avoided. It is also shown that this circular velocity law can be embedded in a geometrical description of spacetime within the standard general relativity framework upon relaxing the usual asymptotic flatness condition. This formulation allows to redefine the introduced Newtonian scale limit in term of the central mass exclusively. Moreover, a satisfactory answer to the galactic escape speed problem can be provided indicating the possibility that one can also get rid of dark matter halo outside the Galaxy.

Lung Cancer-Specific Circular RNAs as Biomarkers

Science.gov (United States)

2017-08-01

determine whether differential expression of circular RNAs can also be detected in cell culture models. Third, we will determine whether circular RNAs can...four of them as representative differentially expressed circRNAs in Table 1. For example , hsa_circRNA_400633 and hsa_circRNA_101100 were upregulated...sequence for hsa_circRNA_400633 and hsa_circRNA_101100, as shown in Figs. 1 and 2 as an example . The top part is the actual sequence and the

Unleashing the Power of the Circular Economy

Energy Technology Data Exchange (ETDEWEB)

Kok, L.; Wurpel, G.; Ten Wolde, A. [IMSA Amsterdam, Amsterdam (Netherlands)

2013-04-15

The concept of circular economy is an economic and industrial system that focuses on the reusability of products and raw materials, reduces value destruction in the overall system and aims at value creation within each tier of the system. This report for Circle Economy (CE) outlines the general direction and concrete steps that must be taken to accomplish a breakthrough to a circular economy. It also provides a knowledge base behind the concept, connecting it to sustainability.

Molecular electron recollision dynamics in intense circularly polarized laser pulses

Science.gov (United States)

Bandrauk, André D.; Yuan, Kai-Jun

2018-04-01

Extreme UV and x-ray table top light sources based on high-order harmonic generation (HHG) are focused now on circular polarization for the generation of circularly polarized attosecond pulses as new tools for controlling electron dynamics, such as charge transfer and migration and the generation of attosecond quantum electron currents for ultrafast magneto-optics. A fundamental electron dynamical process in HHG is laser induced electron recollision with the parent ion, well established theoretically and experimentally for linear polarization. We discuss molecular electron recollision dynamics in circular polarization by theoretical analysis and numerical simulation. The control of the polarization of HHG with circularly polarized ionizing pulses is examined and it is shown that bichromatic circularly polarized pulses enhance recollision dynamics, rendering HHG more efficient, especially in molecules because of their nonspherical symmetry. The polarization of the harmonics is found to be dependent on the compatibility of the rotational symmetry of the net electric field created by combinations of bichromatic circularly polarized pulses with the dynamical symmetry of molecules. We show how the field and molecule symmetry influences the electron recollision trajectories by a time-frequency analysis of harmonics. The results, in principle, offer new unique controllable tools in the study of attosecond molecular electron dynamics.

Circular polarization observed in bioluminescence

NARCIS (Netherlands)

Wynberg, H.; Meijer, E.W.; Hummelen, J.C.; Dekkers, H.P.J.M.; Schippers, P.H.; Carlson, A.D.

1980-01-01

The left and right lanterns of live larvae of the fireflies Photuris lucicrescens and P. versicolor emitted circularly polarized light of opposite sense. A possible mechanism is discussed. [on SciFinder (R)

The potential of a circular economy in the Netherlands: summary report

NARCIS (Netherlands)

Bastein, T.; Roelofs, E.; Rietveld, E.; Hoogendoorn, A.

2013-01-01

For the Dutch Parliament, TNO has assessed the opportunities for a circular economy in The Netherlands. TNO estimates the value of a circular economy to be about 7.3 billion euro. The results and conclusions of the TNO-rapport ‘The potential of a circular economy in the Netherlands’ are sent to the

Circular braiding take-up speed generation using inverse kinematics

NARCIS (Netherlands)

van Ravenhorst, J.H.; Akkerman, Remko

2014-01-01

Circular overbraiding of composite preforms on complex mandrels currently lacks automatic generation of machine control data. To solve this limitation, an inverse kinematics-based procedure was designed and implemented for circular braiding machines with optional guide rings, resulting in a take-up

Generation of circular polarization of the cosmic microwave background

International Nuclear Information System (INIS)

Alexander, Stephon; Ochoa, Joseph; Kosowsky, Arthur

2009-01-01

The standard cosmological model, which includes only Compton scattering photon interactions at energy scales near recombination, results in zero primordial circular polarization of the cosmic microwave background. In this paper we consider a particular renormalizable and gauge-invariant standard model extension coupling photons to an external vector field via a Chern-Simons term, which arises as a radiative correction if gravitational torsion couples to fermions. We compute the transport equations for polarized photons from a Boltzmann-like equation, showing that such a coupling will source circular polarization of the microwave background. For the particular coupling considered here, the circular polarization effect is always negligible compared to the rotation of the linear polarization orientation, also derived using the same formalism. We note the possibility that limits on microwave background circular polarization may probe other photon interactions and related fundamental effects such as violations of Lorentz invariance.

A systematic review on drivers, barriers, and practices towards circular economy

DEFF Research Database (Denmark)

Govindan, Kannan; Hasanagic, Mia

2018-01-01

identified that emerge from the application of a circular economy, no concrete studies exist that investigate current state-of-the-art drivers, barriers and practices in this relevant field. An in-depth exploration of current practices would enhance the circular economy’s significance and would help...... understand its present level of implementation. With this concern, this study provides an analysis of the drivers, barriers and practices that influence the implementation of the circular economy in the context of supply chains through a systematic review. In order to analyse the circular economy’s level...... of implementation, we correlate stakeholders’ perspectives with drivers, barriers, and practices; thus, a multi-perspective framework is proposed. From the results, it is evident that among various stakeholders, the governmental perspective has the maximum positive impact on the implementation of the circular...

Effect of Plate Curvature on Blast Response of Structural Steel Plates

Science.gov (United States)

Veeredhi, Lakshmi Shireen Banu; Ramana Rao, N. V.; Veeredhi, Vasudeva Rao

2018-04-01

In the present work an attempt is made, through simulation studies, to determine the effect of plate curvature on the blast response of a door structure made of ASTM A515 grade 50 steel plates. A door structure with dimensions of 5.142 m × 2.56 m × 10 mm having six different radii of curvatures is analyzed which is subjected to blast load. The radii of curvature investigated are infinity (flat plate), 16.63, 10.81, 8.26, 6.61 and 5.56 m. In the present study, a stand-off distance of 11 m is considered for all the cases. Results showed that the door structure with smallest radius of curvature experienced least plastic deformation and yielding when compared to a door with larger radius of curvature with same projected area. From the present Investigation, it is observed that, as the radius of curvature of the plate increases, the deformation mode gradually shifts from indentation mode to flexural mode. The plates with infinity and 16.63 m radius of curvature have undergone flexural mode of deformation and plates with 6.61 and 5.56 m radius of curvature undergo indentation mode of deformation. Whereas, mixed mode of deformation that consists of both flexural and indentation mode of deformations are seen in the plates with radius of curvature 10.81 and 8.26 m. As the radius of curvature of the plate decreases the ability of the plate to mitigate the effect the blast loads increased. It is observed that the plate with smaller radius of curvature deflects most of the blast energy and results in least indentation mode of deformation. The most significant observation made in the present investigation is that the strain energy absorbed by the steel plate gets reduced to 1/3 rd when the radius of curvature is approximately equal to the stand-off distance which could be the critical radius of curvature.

The Okhotsk Plate and the Eurasia-North America plate boundary zone.

Science.gov (United States)

Hindle, David; Mackey, Kevin

2014-05-01

The Eurasia-North America plate boundary zone transitions from spreading at rates of ~ 25mm/yr in the North Atlantic, to compression at rates of ~ 5mm/yr in the region of the Okhotsk plate. Because the pole of rotation between Eurasia and North America lies more or less on their mutual boundary, there is a linear change in rate along the boundary, and regions near the euler pole are subject to extremely low deformation rates. The Okhotsk - Eurasia - North America triple junction lies slightly south of the rotation pole, placing the Okhotsk plate entirely in a weakly contractional setting. Regions near the triple junction absorb 1mm/yr contraction. Further south, towards the shoreline of the Okhotsk sea, up to 5 mm/yr contraction may be absorbed within the plate. How shortening is accommodated across the boundary remains an open question. One possibility is wholesale extrusion of the entire Okhotsk plate (or possibly its northwestern corner) along two plate boundary strike slip faults (Eurasia-Okhostk and North America Okhotsk). The problem with this model is that the seismic record does not presently clearly support it, with the largest events distributed both within the plate interior and on its boundaries. This may suggest that instead, the Okhotsk plate, and particularly its north-western end, consists of a series of smaller blocks which shuffle against each other, partially accommodating extrusion, but also permitting some internal deformation and change of shape of the Okhotsk plate itself. We present analyses of the very sparse seismic record from the region, as well as geometric-kinematic, tectonic models of the possible deformation of northwest Okhotsk to try to better understand the different probabilities of how this slowly deforming plate boundary zone is behaving.

Installation Torque Tables for Noncritical Applications

Science.gov (United States)

Rivera-Rosario, Hazel T.; Powell, Joseph S.

2017-01-01

The objective of this project is to define torque values for bolts and screws when loading is not a concern. Fasteners require a certain torque to fulfill its function and prevent failure. NASA Glenn Research Center did not have a set of fastener torque tables for non-critical applications without loads, usually referring to hand-tight or wrench-tight torqueing. The project is based on two formulas, torque and pullout load. Torque values are calculated giving way to preliminary data tables. Testing is done to various bolts and metal plates, torqueing them until the point of failure. Around 640 torque tables were developed for UNC, UNF, and M fasteners. Different lengths of thread engagement were analyzed for the 5 most common materials used at GRC. The tables were put together in an Excel spreadsheet and then formatted into a Word document. The plan is to later convert this to an official technical publication or memorandum.

Shed vortex structure and phase-averaged velocity statistics in symmetric/asymmetric turbulent flat plate wakes

Science.gov (United States)

Rai, Man Mohan

2018-05-01

The near wake of a flat plate is investigated via direct numerical simulations. Many earlier experimental investigations have used thin plates with sharp trailing edges and turbulent boundary layers to create the wake. This results in large θ/DTE values (θ is the boundary layer momentum thickness toward the end of the plate and DTE is the trailing edge thickness). In the present study, the emphasis is on relatively thick plates with circular trailing edges (CTEs) resulting in θ/D values less than one (D is the plate thickness and the diameter of the CTE) and vigorous vortex shedding. The Reynolds numbers based on the plate length and D are 1.255 × 106 and 10 000, respectively. Two cases are computed: one with turbulent boundary layers on both the upper and lower surfaces of the plate (statistically the same, symmetric wake, Case TT) and the other with turbulent and laminar boundary layers on the upper and lower surfaces, respectively (asymmetric case, Case TL). The data and understanding obtained are of considerable engineering interest, particularly in turbomachinery where the pressure side of an airfoil can remain laminar or transitional because of a favorable pressure gradient and the suction side is turbulent. Shed-vortex structure and phase-averaged velocity statistics obtained in the two cases are compared here. The upper negative shed vortices in Case TL (turbulent separating boundary layer) are weaker than the lower positive ones (laminar separating boundary layer) at inception (a factor of 1.27 weaker in terms of peak phase-averaged spanwise vorticity at the first appearance of a peak). The upper vortices weaken rapidly as they travel downstream. A second feature of interest in Case TL is a considerable increase in the peak phase-averaged, streamwise normal intensity (random component) with increasing streamwise distance (x/D) that occurs near the positive vortex cores. This behavior is observed for a few diameters in the near wake. This is counter to

Circular polarization memory in single Quantum Dots

International Nuclear Information System (INIS)

Khatsevich, S.; Poem, E.; Benny, Y.; Marderfeld, I.; Gershoni, D.; Badolato, A.; Petroff, P. M.

2010-01-01

Under quasi-resonant circularly polarized optical excitation, charged quantum dots may emit polarized light. We measured various transitions with either positive, negative or no circular-polarization memory. We explain these observations and quantitatively calculate the polarization spectrum. Our model use the full configuration-interaction method, including the electron-hole exchange interaction, for calculating the quantum dot's confined many-carrier states, along with one assumption regarding the spin relaxation of photoexcited carriers: Electrons maintain their initial spin polarization, while holes do not.

Influence of the Metal Volume Fraction on the permanent dent depth and energy absorption of GLARE plates subjected to low velocity impact

Science.gov (United States)

Bikakis, GSE; Savaidis, A.; Zalimidis, P.; Tsitos, S.

2016-11-01

Fiber-metal laminates are hybrid composite materials, consisting of alternating metal layers bonded to fiber-reinforced prepreg layers. GLARE (GLAss REinforced) belongs to this new family of materials. GLARE is the most successful fiber-metal laminate up to now and is currently being used for the construction of primary aerospace structures, such as the fuselage of the Airbus A380 air plane. Impact properties are very important in aerospace structures, since impact damage is caused by various sources, such as maintenance damage from dropped tools, collision between service cars or cargo and the structure, bird strikes and hail. The principal objective of this article is to evaluate the influence of the Metal Volume Fraction (MVF) on the low velocity impact response of GLARE fiber-metal laminates. Previously published differential equations of motion are employed for this purpose. The low velocity impact behavior of various circular GLARE plates is predicted and characteristic values of impact variables, which represent the impact phenomenon, are evaluated versus the corresponding MVF of the examined GLARE material grades. The considered GLARE plates are subjected to low velocity impact under identical impact conditions. A strong effect of the MVF on the maximum impact load and a significant effect on the maximum plate deflection of GLARE plates has been found.

Asphalt Mixture for the First Asphalt Concrete Directly Fastened Track in Korea

Directory of Open Access Journals (Sweden)

Seong-Hyeok Lee

2015-01-01

Full Text Available The research has been initiated to develop the asphalt mixtures which are suitable for the surface of asphalt concrete directly fastened track (ADFT system and evaluate the performance of the asphalt mixture. Three aggregate gradations which are upper (finer, medium, and below (coarser. The nominal maximum aggregate size of asphalt mixture was 10 mm. Asphalt mixture design was conducted at 3 percent air voids using Marshall mix design method. To make impermeable asphalt mixture surface, the laboratory permeability test was conducted for asphalt mixtures of three different aggregate gradations using asphalt mixture permeability tester. Moisture susceptibility test was conducted based on AASHTO T 283. The stripping percentage of asphalt mixtures was measured using a digital camera and analyzed based on image analysis techniques. Based on the limited research results, the finer aggregate gradation is the most suitable for asphalt mixture for ADFT system with the high TSR value and the low stripping percentage and permeable coefficient. Flow number and beam fatigue tests for finer aggregate asphalt mixture were conducted to characterize the performance of asphalt mixtures containing two modified asphalt binders: STE-10 which is styrene-butadiene-styrene (SBS polymer and ARMA which is Crum rubber modified asphalt. The performance tests indicate that the STE-10 shows the higher rutting life and fatigue life.

The optimum circular field size for dental radiography with intraoral films

International Nuclear Information System (INIS)

van Straaten, F.J.; van Aken, J.

1982-01-01

Intraoral radiographs are often made with circular fields to irradiate the film, and in many instances these fields are much larger than the film. The feasibility of reducing a circular radiation field without increasing the probability of excessive cone cutting was evaluated clinically, and an optimum field size was determined. A circular radiation field 4.5 cm. at the tube end was found to minimize cone cutting and reduce the area of tissue irradiated by at least 44 percent. Findings suggest that current I.C.R.P. recommendations for a 6 to 7.5 cm. diameter circular field may be too liberal

FROM CIRCULAR ECONOMY TO BLUE ECONOMY

Directory of Open Access Journals (Sweden)

Iustin-Emanuel, ALEXANDRU

2014-11-01

Full Text Available Addressing the subject of this essay is based on the background ideas generated by a new branch of science - Biomimicry. According to European Commissioner for the Environment, "Nature is the perfect model of circular economy". Therefore, by imitating nature, we are witnessing a process of cycle redesign: production-consumption-recycling. The authors present some reflections on the European Commission's decision to adopt after July 1, 2014 new measures concerning the development of more circular economies. Starting from the principles of Ecolonomy, which is based on the whole living paradigm, this paper argues for the development within each economy of entrepreneurial policies related to the Blue economy. In its turn, Blue economy is based on scientific analyses that identify the best solutions in a business. Thus, formation of social capital will lead to healthier and cheaper products, which will stimulate entrepreneurship. Blue economy is another way of thinking economic practice and is a new model of business design. It is a healthy, sustainable business, designed for people. In fact, it is the core of the whole living paradigm through which, towards 2020, circular economy will grow more and more.

Finite element analysis of a solar collector plate using two plate geometries

Directory of Open Access Journals (Sweden)

Diego Manuel Medina Carril

2016-09-01

Full Text Available The thermal behavior of an absorber plate in a solar collector is investigated using finite element analysis. The thermal behavior and efficiency of two absorber plate geometries are studied, using a typical solar collector with a rectangular profile as reference, and a proposed absorber plate with curved geometry. An analysis of the most important parameters involved in the design of the absorber plate was carried out, indicating that the curved geometry of the absorber plate yields an average efficiency ~25% higher than the conventional rectangular geometry. The results suggest that a curved profile made of materials such as aluminum with thermal conductivity higher than 200W/m°C, plate thickness of the order of 2-3mm and with a large density of tubes per unit area of the collector´s plate greatly benefits the thermal efficiency of the solar collector.

Chemical detection of cysteine-rich circular petides in selected ...

African Journals Online (AJOL)

Cysteine-rich circular peptides (CRCs) comprise a large family of gene encoded and low molecular weight polypeptides that has recently engaged the attention of scientists. This class of peptides exhibit a continuous circular configuration and a cystine knot backbone, which defines their resilient nature-directed structural ...

The Circular Economy and the Leading European Retailers: A Research Note

Directory of Open Access Journals (Sweden)

Peter Jones

2018-03-01

Full Text Available The concept of the circular economy is gaining momentum in political and business thinking about the transition to a more sustainable future. EuroCommerce and the European Retail Round Table, for example, have argued that leading retailers are keen to play a leading role in shaping the circular economy within Europe. This exploratory research note outlines the characteristic features of the concept of the circular economy, provides some illustrations of how Europe’s leading retailers are publicly addressing circular economy approaches and offers some general reflections on the application of the concept within the retail sector of the economy. The findings reveal that almost 50% of the leading European retailers signalled a commitment to the circular economy and to the principles underpinning it and a number of them looked to evidence their commitment within their retail operations. That said the authors suggest that If Europe’s leading retailers’ public commitments to a more circular economy are to become a reality then they will not only need to effect a radical change in their current business models and that this will need to be accompanied by radical changes in consumers consumption behaviour. More contentiously, there must be concerns that the leading European retailers might effectively capture the concept of the circular economy to justify continuing economic growth.

[Integrated evaluation of circular agriculture system: a life cycle perspective].

Science.gov (United States)

Liang, Long; Chen, Yuan-Quan; Gao, Wang-Sheng

2010-11-01

For the point of view that recycling economy system is one of ways to achieve the low-carbon economy, we have made an evaluation on a typical circular agriculture duck industry in Hunan Province, China, through improving the framework of life cycle assessment (LCA). The analysis indicated that the consumption of non-renewable resources, land and water were 48.629 MJ, 2.36 m2 and 1 321.41 kg, while the potential greenhouse gas (GHGs), acidification, eutrophication, human toxicity, freshwater ecotoxicity and terrestrial ecotoxicity were 11 543.26 g (CO2 eq), 52.36g (SO2eq), 25.83g (PO4eq), 1.26, 60.74 and 24.65 g (1,4-DCBeq), respectively. The potential damage of aquatic eutrophication, freshwater ecotoxicity and terrestrial ecotoxicity was more serious than that of GHGs. Main results were following: i. the circular agricultural chain promoted the principle of "moderate circulation", which based on the traditional production methods; ii. circular agriculture could not blindly pursue low carbon development. Instead, soil and biological carbon sequestration should be considered, in addition to reducing carbon emissions; iii. circular economy and circular agriculture should take other potential environmental impacts into account such as acidification, eutrophication and ecotoxicity,with the exception to carbon emissions,to developed integrated system assessment; iv. LCA could provide a comprehensive assessment of circular agriculture, and it was worth of further study.

PCDDB: the Protein Circular Dichroism Data Bank, a repository for circular dichroism spectral and metadata.

Science.gov (United States)

Whitmore, Lee; Woollett, Benjamin; Miles, Andrew John; Klose, D P; Janes, Robert W; Wallace, B A

2011-01-01

The Protein Circular Dichroism Data Bank (PCDDB) is a public repository that archives and freely distributes circular dichroism (CD) and synchrotron radiation CD (SRCD) spectral data and their associated experimental metadata. All entries undergo validation and curation procedures to ensure completeness, consistency and quality of the data included. A web-based interface enables users to browse and query sample types, sample conditions, experimental parameters and provides spectra in both graphical display format and as downloadable text files. The entries are linked, when appropriate, to primary sequence (UniProt) and structural (PDB) databases, as well as to secondary databases such as the Enzyme Commission functional classification database and the CATH fold classification database, as well as to literature citations. The PCDDB is available at: http://pcddb.cryst.bbk.ac.uk.

Plate removal following orthognathic surgery.

Science.gov (United States)

Little, Mhairi; Langford, Richard Julian; Bhanji, Adam; Farr, David

2015-11-01

The objectives of this study are to determine the removal rates of orthognathic plates used during orthognathic surgery at James Cook University Hospital and describe the reasons for plate removal. 202 consecutive orthognathic cases were identified between July 2004 and July 2012. Demographics and procedure details were collected for these patients. Patients from this group who returned to theatre for plate removal between July 2004 and November 2012 were identified and their notes were analysed for data including reason for plate removal, age, smoking status, sex and time to plate removal. 3.2% of plates were removed with proportionally more plates removed from the mandible than the maxilla. 10.4% of patients required removal of one or more plate. Most plates were removed within the first post-operative year. The commonest reasons for plate removal were plate exposure and infection. The plate removal rates in our study are comparable to those seen in the literature. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Role of Food Logistics Management in a circular economy

NARCIS (Netherlands)

Bloemhof-Ruwaard, J.M.; Groot, J.J.; Snels, J.C.M.A.

2016-01-01

In this paper we will discuss the role of food logistics management in a circular economy. Specific pillars in Circular Economy such as Closed Loop supply Chain management and Industrial Ecology will be discussed. Apart from a research agenda, we will provide exemplary cases in practice showing the

Bending and stretching of plates

CERN Document Server

Mansfield, E H; Hemp, W S

1964-01-01

The Bending and Stretching of Plates deals with elastic plate theory, particularly on small- and large-deflexion theory. Small-deflexion theory concerns derivation of basic equations, rectangular plates, plates of various shapes, plates whose boundaries are amenable to conformal transformation, plates with variable rigidity, and approximate methods. Large-deflexion theory includes general equations and some exact solutions, approximate methods in large-deflexion theory, asymptotic large-deflexion theories for very thin plates. Asymptotic theories covers membrane theory, tension field theory, a

Entropic derivation of F=ma for circular motion

International Nuclear Information System (INIS)

Duncan, Michael; Myrzakulov, Ratbay; Singleton, Douglas

2011-01-01

We examine the entropic picture of Newton's second law for the case of circular motion. It is shown that one must make modifications to the derivation of F=ma due to a change in the effective Unruh temperature for circular motion. These modifications present a challenge to the entropic derivation of Newton's second law, but also open up the possibility to experimentally test and constrain this model for large centripetal accelerations.

Removal and replacement of fuel rods in nuclear fuel assembly

International Nuclear Information System (INIS)

Shallenberger, J.M.; Ferlan, S.J.

1983-01-01

Apparatus for replacing components of a nuclear fuel assembly stored in a pit under about 10 m. of water. The fuel assembly is secured in a container which is rotatable from the upright position to an inverted position in which the bottom nozzle is upward. The bottom nozzle plate is disconnected from the control-rod thimbles by means of a cutter for severing the welds. To guide and provide lateral support for the cutter a fixture including bushings is provided, each encircling a screw fastener and sealing the region around a screw fastener to trap the chips from the severed weld. Chips adhering to the cutter are removed by a suction tube of an eductor. (author)

Circular RNA profiling reveals that circular RNAs from ANXA2 can be used as new biomarkers for multiple sclerosis.

Science.gov (United States)

Iparraguirre, Leire; Muñoz-Culla, Maider; Prada-Luengo, Iñigo; Castillo-Triviño, Tamara; Olascoaga, Javier; Otaegui, David

2017-09-15

Multiple sclerosis is an autoimmune disease, with higher prevalence in women, in whom the immune system is dysregulated. This dysregulation has been shown to correlate with changes in transcriptome expression as well as in gene-expression regulators, such as non-coding RNAs (e.g. microRNAs). Indeed, some of these have been suggested as biomarkers for multiple sclerosis even though few biomarkers have reached the clinical practice. Recently, a novel family of non-coding RNAs, circular RNAs, has emerged as a new player in the complex network of gene-expression regulation. MicroRNA regulation function through a 'sponge system' and a RNA splicing regulation function have been proposed for the circular RNAs. This regulating role together with their high stability in biofluids makes them seemingly good candidates as biomarkers. Given the dysregulation of both protein-coding and non-coding transcriptome that have been reported in multiple sclerosis patients, we hypothesised that circular RNA expression may also be altered. Therefore, we carried out expression profiling of 13.617 circular RNAs in peripheral blood leucocytes from multiple sclerosis patients and healthy controls finding 406 differentially expressed (P-value  1.5) and demonstrate after validation that, circ_0005402 and circ_0035560 are underexpressed in multiple sclerosis patients and could be used as biomarkers of the disease. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Success Factors of Sustainable Social Enterprises Through Circular Economy Perspective

Directory of Open Access Journals (Sweden)

Stratan Dumitru

2017-05-01

Full Text Available The scope of the research is to find out how social entrepreneurship operations can be modelled within existing business methods using circular economy principles. A literature review was undertaken in order to clarify and find out different opinions regarding circularity and social businesses models. Moreover, the author interviewed managers of different social mission organizations in order to find out the critical factors that determine the sustainability and performances of the organizations. Using the results of the field and desk research, the author suggests the following business model elements to be considered by social enterprises aiming to implement circular economy principles: Desired social and environment vision; Value proposition; Alignment of organizations to the strategy and acceleration of change through executive leadership implication; Financial sustainable perspective: a to increase financial resources and b to manage costs; Stakeholders perspective: a customers segments, b users, c employees, d community beneficiaries, e channels, f customer relationships, g Key partnerships; Internal process perspective: a processes necessary to use circular economy principles; b impact measurement and key activities; c internal and external communication; Resources perspective: a networks; b skills on circular principles and social impact; c information and technologies.`

Time can't be circular

CERN Multimedia

2003-01-01

"Delivering the Albert Einstein lecture at the Centre for Philosophy and Foundations of Science on Tuesday, Nobel Laureate Professor Gerard Hooft said that any notion of time can not be circular or have loops or multi dimensionality" (1/2 page).

Administrative circular No. 12

CERN Document Server

HR Department

2006-01-01

On the recommendation of the Standing Concertation Committee, the Director-General has approved the amounts used for the reimbursements mentioned in Administrative Circular No. 12 as follows: The figures, effective from 1 September 2006, are: Paragraph 8a: 17 Swiss francs Paragraph 9a: 682 Swiss francs Paragraph 9b: 34 Swiss francs Human Resources Department Tel. 79257/72862

Administrative Circular No. 26 (Rev. 9) – Recognition of Merit

CERN Multimedia

2012-01-01

Administrative Circular No. 26 (Rev. 9) entitled "Recognition of Merit”, approved by the Director-General following discussion in the Standing Concertation Committee meeting on 27 September 2011 is available on the intranet site of the Human Resources Department: https://cern.ch/hr-docs/admincirc/admincirc.asp The circular was above all revised in order to integrate the new CERN Competency Model into the annual procedure of performance appraisal. It cancels and replaces Administrative Circular No. 26 (Rev. 8) entitled "Recognition of merit” of September 2008. Department Head Office HR Department

Characteristics of circular features on comet 67P/Churyumov-Gerasimenko

Science.gov (United States)

Deller, J. F.; Güttler, C.; Tubiana, C.; Hofmann, M.; Sierks, H.

2017-09-01

Comet 67P/Churyumov-Gerasimenko shows a large variety of circular structures such as pits, elevated roundish features in Imhotep, and even a single occurrence of a plausible fresh impact crater. Imaging the pits in the Ma'at region, aiming to understand their structure and origin drove the design of the final descent trajectory of the Rosetta spacecraft. The high-resolution images obtained during the last mission phase allow us to study these pits as exemplary circular features. A complete catalogue of circular features gives us the possibility to compare and classify these structures systematically.

The Potential of Circular Economy in Sustainable Buildings

DEFF Research Database (Denmark)

Malabi Larsen, Leonora Charlotte; Birgisdottir, Harpa; Birkved, Morten

2018-01-01

benefits of designing the buildings concrete structure for disassembly, with the purpose of reuse, as well as to exemplify how circular economy can be applied in future building projects. Moreover, the paper aims at suggesting a more industry focused approach towards circular economy in order to seize...... the inherent potentials. As a result, it was found that recycling and energy recovery are the most common circular economy practices in the building industry, even though the economic and environmental benefits of reuse are believed to be much higher. This observation is supported by the findings of the case...... and glass, thereby enabling easier disassembly for both reuse and recycling. However, main challenges preventing the industry from seizing these potentials are identified as: focus on short term goals, complex supply chains, lack of collaboration between stakeholders and absence of a commonly agreed...

Slotted Circularly Polarized Microstrip Antenna for RFID Application

Directory of Open Access Journals (Sweden)

S. Kumar

2017-12-01

Full Text Available A single layer coaxial fed rectangular microstrip slotted antenna for circular polarization (CP is proposed for radio frequency identification (RFID application. Two triangular shaped slots and one rectangular slot along the diagonal axis of a square patch have been embedded. Due to slotted structure along the diagonal axis and less surface area, good quality of circular polarization has been obtained with the reduction in the size of microstrip antenna by 4.04 %. Circular polarization radiation performance has been studied by size and angle variation of diagonally slotted structures. The experimental result found for 10-dB return loss is 44 MHz with 10MHz of 3dB Axial Ratio (AR bandwidth respectively at the resonant frequency 910 MHz. The overall proposed antenna size including the ground plane is 80 mm x 80 mm x 4.572 mm.

A New Limit on CMB Circular Polarization from SPIDER

Energy Technology Data Exchange (ETDEWEB)

Nagy, J. M.; Ade, P. A. R.; Amiri, M.; Benton, S. J.; Bergman, A. S.; Bihary, R.; Bock, J. J.; Bond, J. R.; Bryan, S. A.; Chiang, H. C.; Contaldi, C. R.; Doré, O.; Duivenvoorden, A. J.; Eriksen, H. K.; Farhang, M.; Filippini, J. P.; Fissel, L. M.; Fraisse, A. A.; Freese, K.; Galloway, M.; Gambrel, A. E.; Gandilo, N. N.; Ganga, K.; Gudmundsson, J. E.; Halpern, M.; Hartley, J.; Hasselfield, M.; Hilton, G.; Holmes, W.; Hristov, V. V.; Huang, Z.; Irwin, K. D.; Jones, W. C.; Kuo, C. L.; Kermish, Z. D.; Li, S.; Mason, P. V.; Megerian, K.; Moncelsi, L.; Morford, T. A.; Netterfield, C. B.; Nolta, M.; Padilla, I. L.; Racine, B.; Rahlin, A. S.; Reintsema, C.; Ruhl, J. E.; Runyan, M. C.; Ruud, T. M.; Shariff, J. A.; Soler, J. D.; Song, X.; Trangsrud, A.; Tucker, C.; Tucker, R. S.; Turner, A. D.; List, J. F. Van Der; Weber, A. C.; Wehus, I. K.; Wiebe, D. V.; Young, E. Y.

2017-08-01

We present a new upper limit on CMB circular polarization from the 2015 flight of SPIDER, a balloon-borne telescope designed to search for $B$-mode linear polarization from cosmic inflation. Although the level of circular polarization in the CMB is predicted to be very small, experimental limits provide a valuable test of the underlying models. By exploiting the non-zero circular-to-linear polarization coupling of the HWP polarization modulators, data from SPIDER's 2015 Antarctic flight provides a constraint on Stokes $V$ at 95 and 150 GHz from $33<\\ell<307$. No other limits exist over this full range of angular scales, and SPIDER improves upon the previous limit by several orders of magnitude, providing 95% C.L. constraints on $\\ell (\\ell+1)C_{\\ell}^{VV}/(2\\pi)$ ranging from 141 $\\mu K ^2$ to 203 $\\mu K ^2$ at 150 GHz for a thermal CMB spectrum. As linear CMB polarization experiments become increasingly sensitive, the techniques described in this paper can be applied to obtain stronger constraints on circular polarization.

Frenkel-exciton decomposition analysis of circular dichroism and circularly polarized luminescence for multichromophoric systems.

Science.gov (United States)

Shiraogawa, Takafumi; Ehara, Masahiro; Jurinovich, Sandro; Cupellini, Lorenzo; Mennucci, Benedetta

2018-06-15

Recently, a method to calculate the absorption and circular dichroism (CD) spectra based on the exciton coupling has been developed. In this work, the method was utilized for the decomposition of the CD and circularly polarized luminescence (CPL) spectra of a multichromophoric system into chromophore contributions for recently developed through-space conjugated oligomers. The method which has been implemented using rotatory strength in the velocity form and therefore it is gauge-invariant, enables us to evaluate the contribution from each chromophoric unit and locally excited state to the CD and CPL spectra of the total system. The excitonic calculations suitably reproduce the full calculations of the system, as well as the experimental results. We demonstrate that the interactions between electric transition dipole moments of adjacent chromophoric units are crucial in the CD and CPL spectra of the multichromophoric systems, while the interactions between electric and magnetic transition dipole moments are not negligible. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Relationship between chromatin complexity and nuclear envelope circularity in hippocampal pyramidal neurons

International Nuclear Information System (INIS)

Pantic, Igor; Basailovic, Milos; Paunovic, Jovana; Pantic, Senka

2015-01-01

Highlights: •We analyzed chromatin structure and nuclear envelope of 200 hippocampal pyramidal neurons. •Fractal and GLCM mathematical parameters were calculated each chromatin structure. •Nuclear shape was quantified by calculating circularity of the nuclear envelope. •Circularity was in significant relationship with chromatin fractal dimension. •Strong correlation was detected between circularity and some GLCM parameters. -- Abstract: In this study we tested the existence and strength of the relationship between circularity of nuclear envelope and mathematical parameters of chromatin structure. Coronal sections of the brain were made in 10 male albino mice. The brain tissue was stained using a modification of Feulgen method for DNA visualization. A total of 200 hippocampal pyramidal neurons (20 per animal) were visualized using DEM 200 High-Speed Color CMOS Chip and Olympus CX21FS1 microscope. Circularity of the nuclear membrane was calculated in ImageJ (NIH, USA) after the nuclear segmentation, based on the freehand selection of the nuclear regions of interest. Circularity was determined from the values of area and perimeter. For each chromatin structure, using fractal and grey level co-occurrence matrix (GLCM) algorithms, we determined the values of fractal dimension, lacunarity, angular second moment, GLCM entropy, inverse difference moment, GLCM correlation, and GLCM contrast. It was found that circularity is in a significant correlation (p < 0.05) with fractal dimension as the main parameter of fractal complexity analysis. Also, circularity was in a very strong relationship (p < 0.001) with certain parameters of grey level co-occurrence matrix such as the angular second moment and GLCM correlation. This is the first study to indicate that nuclear shape is significantly related to mathematical parameters of higher chromatin organization. Also, it seems that circularity of the nuclear envelope is a good predictor of certain features of chromatin

Development of circular filters for active facilities

International Nuclear Information System (INIS)

Pratt, R.P.

1986-01-01

An assessment of problems associated with remote handling, changing and disposal of filters suggested that significant improvements to filtration systems could be made if circular geometries were adopted in place of conventional systems. Improved systems have been developed and are now available for a range of applications and air flow rates. Where primary filters are installed within the active cell or cave, circular filters incorporating a lip seal have been developed which enable the filters to be sealed into the facility without recourse to clamping. For smaller cells, a range of push-through filter change systems have been developed, the principal feature being that the filter is passed into the housing from the clean side, but transferred from the housing directly into the cell for subsequent disposal. For plant room applications, circular bag change canister systems have been developed which ease the sealing and bag change operation. Such systems have a rated air flow of up to 3000 m 3 /h whilst still allowing ultimate disposal via the 200 litre waste drum route without prior volume reduction of the filter inserts. (author)

Higgs measurement at $e^+e^-$ circular colliders

CERN Document Server

Ruan, Manqi

2016-01-01

Now that the mass of the Higgs boson is known, circular electron positron colliders, able to measure the properties of these particles with high accuracy, are receiving considerable attention. Design studies have been launched (i) at CERN with the Future Circular Colliders (FCC), of which an e+e- collider is a potential first step (FCC-ee, formerly caller TLEP) and (ii) in China with the Circular Electron Positron Collider (CEPC). Hosted in a tunnel of at least 50 km (CEPC) or 80-100 km (FCC), both projects can deliver very high luminosity from the Z peak to HZ threshold (CEPC) and even to the top pair threshold and above (FCC-ee). At the ZH production optimum, around 240 GeV, the FCC-ee (CEPC) will be able to deliver 10 (5) ab-1 integrated luminosity in 5 (10) years with 4 (2) interaction points: hence to produce millions of Higgs bosons through the Higgsstrahlung process and vector boson fusion processes. This sample opens the possibility of subper- cent precision absolute measurements of the Higgs boson co...

Higgs Measurement at e+e- Circular Colliders

CERN Document Server

Ruan, M

2014-01-01

Now that the mass of the Higgs boson is known, circular electron positron colliders, able to measure the properties of these particles with high accuracy, are receiving considerable attention. Design studies have been launched (i) at CERN with the Future Circular Colliders (FCC), of which an e+e- collider is a potential first step (FCC-ee, formerly caller TLEP) and (ii) in China with the Circular Electron Positron Collider (CEPC). Hosted in a tunnel of at least 50 km (CEPC) or 80-100 km (FCC), both projects can deliver very high luminosity from the Z peak to HZ threshold (CEPC) and even to the top pair threshold and above (FCC-ee). At the ZH production optimum, around 240 GeV, the FCC-ee (CEPC) will be able to deliver 10 (5) ab-1 integrated luminosity in 5 (10) years with 4 (2) interaction points: hence to produce millions of Higgs bosons through the Higgsstrahlung process and vector boson fusion processes. This sample opens the possibility of subper-cent precision absolute measurements of the Higgs boson cou...

Multi-band circular polarizer based on a twisted triple split-ring resonator

International Nuclear Information System (INIS)

Wu Song; Huang Xiao-Jun; Yang He-Lin; Xiao Bo-Xun; Jin Yan

2014-01-01

A multi-band circular polarizer using a twisted triple split-ring resonator (TSRR) is presented and studied numerically and experimentally. At four distinct resonant frequencies, the incident linearly polarized wave can be transformed into left/right-handed circularly polarized waves. Numerical simulation results show that a y-polarized wave can be converted into a right-handed circularly polarized wave at 5.738 GHz and 9.218 GHz, while a left-handed circularly polarized wave is produced at 7.292 GHz and 10.118 GHz. The experimental results are in agreement with the numerical results. The surface current distributions are investigated to illustrate the polarization transformation mechanism. Furthermore, the influences of the structure parameters of the circular polarizer on transmission spectra are discussed as well. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Circular polarization observed in bioluminescence

NARCIS (Netherlands)

Wijnberg, Hans; Meijer, E.W.; Hummelen, J.C.; Dekkers, H.P.J.M.; Schippers, P.H.; Carlson, A.D.

1980-01-01

While investigating circular polarization in luminescence, and having found it in chemiluminescence, we have studied bioluminescence because it is such a widespread and dramatic natural phenomenon. We report here that left and right lanterns of live larvae of the fireflies, Photuris lucicrescens and

History of internal fixation with plates (part 2): new developments after World War II; compressing plates and locked plates.

Science.gov (United States)

Hernigou, Philippe; Pariat, Jacques

2017-07-01

The first techniques of operative fracture with plates were developed in the 19th century. In fact, at the beginning these methods consisted of an open reduction of the fracture usually followed by a very unstable fixation. As a consequence, the fracture had to be opened with a real risk of (sometimes lethal) infection, and due to unstable fixation, protection with a cast was often necessary. During the period between World Wars I and II, plates for fracture fixation developed with great variety. It became increasingly recognised that, because a fracture of a long bone normally heals with minimal resorption at the bone ends, this may result in slight shortening and collapse, so a very rigid plate might prevent such collapse. However, as a consequence, delayed healing was observed unless the patient was lucky enough to have the plate break. One way of dealing with this was to use a slotted plate in which the screws could move axially, but the really important advance was recognition of the role of compression. After the first description of compression by Danis with a "coapteur", Bagby and Müller with the AO improved the technique of compression. The classic dynamic compression plates from the 1970s were the key to a very rigid fixation, leading to primary bone healing. Nevertheless, the use of strong plates resulted in delayed union and the osteoporosis, cancellous bone, comminution, and/or pathological bone resulted in some failures due to insufficient stability. Finally, new devices represented by locking plates increased the stability, contributing to the principles of a more biological osteosynthesis while giving enough stability to allow immediate full weight bearing in some patients.

Selection of parameters on laser cutting mild steel plates taking account of some manufacturing purposes