WorldWideScience

Sample records for cosserat continua-based micro

  1. Experimental micro mechanics methods for conventional and negative Poisson's ratio cellular solids as Cosserat continua

    Science.gov (United States)

    Lakes, R.

    1991-01-01

    Continuum representations of micromechanical phenomena in structured materials are described, with emphasis on cellular solids. These phenomena are interpreted in light of Cosserat elasticity, a generalized continuum theory which admits degrees of freedom not present in classical elasticity. These are the rotation of points in the material, and a couple per unit area or couple stress. Experimental work in this area is reviewed, and other interpretation schemes are discussed. The applicability of Cosserat elasticity to cellular solids and fibrous composite materials is considered as is the application of related generalized continuum theories. New experimental results are presented for foam materials with negative Poisson's ratios.

  2. A version of Hill's lemma for Cosserat continuum

    Institute of Scientific and Technical Information of China (English)

    Xikui Li; Qipeng Liu

    2009-01-01

    On the basis of Hill's lemma for classical Cauchy continuum, a version of Hill's lemma for micro-macro homogenization modeling of heterogeneous Cosserat continuum is presented in the frame of average-field theory. The admissible boundary conditions required to prescribe on the representative volume element for the modeling are extracted and discussed to ensure the satisfaction of HillMandel energy condition and the first-order average field theory.

  3. The micro-directional model of Cosserat continuum description for granular materials%基于细观方向平均模型的颗粒材料宏观Cosserat连续体本构关系

    Institute of Scientific and Technical Information of China (English)

    刘其鹏; 李锡夔; 楚锡华

    2011-01-01

    提出了基于细观微-方向模型(Micro—Directional Model)的宏观Cosserat连续体本构关系。在细观尺度上考虑颗粒旋转自由度及接触力矩,微结构的影响通过接触分布函数体现。给出均质各向同性Cosserat连续体模型弹性常数的细观参数表达式,并建议了二维情况下内尺度参数的细观力学表达式。对颗粒材料宏观行为分别进行离散单元法数值模拟和基于本文所给表达式的理论预测,二者的一致性说明了所发展模型的有效性。%This paper develops the micro-directional model of Cosserat continuum, taking into account the particle rotation and contact couples on the micro level. The effects of micro structures on macro behavior are embodied with the contact distribution function. The specific formulae of macro elastic constants under homogeneous and isotropic assumption are derived. Micro-mechanically-based expressions of the intrinsic length scale are also suggested for two-dimensional case. The validity of the proposed model is verified through the comparisons of theoretical predictions from the developed model and numerical simulation by using discrete element method on overall behavior of a granular assembly with regular arrangement.

  4. Finite element analysis of 3D elastic-plastic frictional contact problem for Cosserat materials

    Science.gov (United States)

    Zhang, S.; Xie, Z. Q.; Chen, B. S.; Zhang, H. W.

    2013-06-01

    The objective of this paper is to develop a finite element model for 3D elastic-plastic frictional contact problem of Cosserat materials. Because 3D elastic-plastic frictional contact problems belong to the unspecified boundary problems with nonlinearities in both material and geometric forms, a large number of calculations are needed to obtain numerical results with high accuracy. Based on the parametric variational principle and the corresponding quadratic programming method for numerical simulation of frictional contact problems, a finite element model is developed for 3D elastic-plastic frictional contact analysis of Cosserat materials. The problems are finally reduced to linear complementarity problems (LCP). Numerical examples show the feasibility and importance of the developed model for analyzing the contact problems of structures with materials which have micro-polar characteristics.

  5. Statics and kinematics of discrete Cosserat-type granular materials

    NARCIS (Netherlands)

    Kruyt, N.P.

    2003-01-01

    A theoretical framework is presented for the statics and kinematics of discrete Cosserat-type granular materials. In analogy to the force and moment equilibrium equations for particles, compatibility equations for closed loops are formulated in the two-dimensional case for relative displacements and

  6. Finite Element Analysis Using a Cosserat Linear Elastic Continuum

    Directory of Open Access Journals (Sweden)

    Alfonso Mariano Ramos-Cañón

    2017-02-01

    Full Text Available Contexto: Los resultados experimentales en materiales granulares muestran que el comportamiento esfuerzo deformación tiene dependencia con la escala de análisis, sin embargo, debido a las supocisiones intrínsecas que tiene la mecánica del medio continuo, los análisis de elementos finitos basados en el continuo continuo de Boltzmann no permite tener en cuenta longitudes características en su formulación que refleje la escala. Método: En este trabajo se presenta la formulación especializada de los elementos finitos para un problema de deformación plana para el continuo de Cosserat. Se presentan los grados de libertad de un elemento finito cuadrilatero y se deduce el operador diferencial para obtener el vector de deformación, su función de forma, la matriz de interpolación, la matriz de rigidez y el vector de fuerza nodal. Finalmente se implementa el continuo de cosserat con el elemento descrito en un programa de elementos finitos codificado por los autores.  El programa se ejecuta para resolver el problema de esfuerzos y deformaciones en una capa homogenea de material con comportamiento lineal elástico. Resultados: Se obtiene las diferencias entre los componentes de esfuerzos y deformaciones de corte entre el continuo convencional y el de Cosserat junto con la aparición de momentos  a nivel de punto de Gauss. Conclusiones: La deducción e implementación del continuo de Cosserat permite un análisis de elementos finitos alternativo al del continuo Convencional con la posibilidad de introducir una longitud característica en su formulación para tener en cuenta los efectos de escala y rotaciones que se observan en materiales granulares.

  7. The dynamics of folding instability in a constrained Cosserat medium

    Science.gov (United States)

    Gourgiotis, Panos A.; Bigoni, Davide

    2017-04-01

    Different from Cauchy elastic materials, generalized continua, and in particular constrained Cosserat materials, can be designed to possess extreme (near a failure of ellipticity) orthotropy properties and in this way to model folding in a three-dimensional solid. Following this approach, folding, which is a narrow zone of highly localized bending, spontaneously emerges as a deformation pattern occurring in a strongly anisotropic solid. How this peculiar pattern interacts with wave propagation in the time-harmonic domain is revealed through the derivation of an antiplane, infinite-body Green's function, which opens the way to integral techniques for anisotropic constrained Cosserat continua. Viewed as a perturbing agent, the Green's function shows that folding, emerging near a steadily pulsating source in the limit of failure of ellipticity, is transformed into a disturbance with wavefronts parallel to the folding itself. The results of the presented study introduce the possibility of exploiting constrained Cosserat solids for propagating waves in materials displaying origami patterns of deformation. This article is part of the themed issue 'Patterning through instabilities in complex media: theory and applications.'

  8. PARAMETRIC VARIATIONAL PRINCIPLE BASED ELASTIC-PLASTIC ANALYSIS OF COSSERAT CONTINUUM

    Institute of Scientific and Technical Information of China (English)

    Zhang Hongwu; Wang Hui; Chen Biaosong; Xie Zhaoqian

    2007-01-01

    A new algorithm is developed based on the parametric variational principle for elastic-plastic analysis of Cosserat continuum. The governing equations of the classic elastic-plastic problem are regularized by adding rotational degrees of freedom to the conventional translational degrees of freedom in conventional continuum mechanics. The parametric potential energy principle of the Cosserat theory is developed, from which the finite element formulation of the Cosserat theory and the corresponding parametric quadratic programming model are constructed. Strain localization problems are computed and the mesh independent results are obtained.

  9. Detection of microrotational effects and Cosserat moduli reconstruction using wave propagation

    Science.gov (United States)

    Pasternak, Elena; Dyskin, Arcady

    2014-05-01

    We propose a method of detection of effects of internal rotation and reconstruction of the Cosserat elastic moduli using the measurements of velocities of the p-wave and the high frequency twist wave as well as the shear wave dispersion relationships. We consider the general isotropic, transverse isotropic and orthotropic Cosserat continua. A phase shift method and reconstruction algorithms are proposed that utilise the measurements of dispersion relationship. It is shown that in a general isotropic Cosserat continuum the information obtained from these wave measurements is insufficient for the complete moduli reconstruction. However the moduli that can be reconstructed provide sufficient information for detection of the presence of microrotational effects. The full moduli reconstruction is shown to be possible in the case of a 3D isotropic Cosserat continuum governed by at most 4 independent parameters. Such a continuum is suggested for a particulate material consisting of spherical particles connected by normal, shear and rotational links. Another case when the full reconstruction is possible consists of 2D orthotropic Cosserat continuum modelling particulate material with square packing of cylindrical particles and 2D isotropic Cosserat continuum modelling hexagonal packing of cylindrical particles. In the 2D materials the measurements of p-wave velocity and the shear wave dispersion relationship are sufficient for complete reconstruction of all moduli.

  10. On the General Analytical Solution of the Kinematic Cosserat Equations

    KAUST Repository

    Michels, Dominik L.

    2016-09-01

    Based on a Lie symmetry analysis, we construct a closed form solution to the kinematic part of the (partial differential) Cosserat equations describing the mechanical behavior of elastic rods. The solution depends on two arbitrary analytical vector functions and is analytical everywhere except a certain domain of the independent variables in which one of the arbitrary vector functions satisfies a simple explicitly given algebraic relation. As our main theoretical result, in addition to the construction of the solution, we proof its generality. Based on this observation, a hybrid semi-analytical solver for highly viscous two-way coupled fluid-rod problems is developed which allows for the interactive high-fidelity simulations of flagellated microswimmers as a result of a substantial reduction of the numerical stiffness.

  11. 梯度增强Cosserat连续体的广义Hill定理%A generalized Hill's lemma for gradient-enhanced Cosserat continuum

    Institute of Scientific and Technical Information of China (English)

    李锡夔; 张俊波; 张雪

    2011-01-01

    Based on the Hill's lemma for classical Cauchy continuum, a generalized Hill's lemma for micro-macro homogenization modeling of gradient-enhanced Cosserat continuum is presented in the frame of the average-field theory. In the gradient-enhanced Cosserat continuum modeling not only the strain and stress tensors defined in classical Cosserat continuum but also their gradients at the macroscopic sampling point are attributed to associated micro-structural representative volume element (RVE). The admissible boundary conditions required to prescribe on the RVE in strong and/or weak forms for the modeling are discussed and given to ensure the satisfaction of the enhanced Hill-Mandel energy condition and the average-field theory.%基于经典Cauchy连续体的Hill定理,在平均场理论的框架下导出了梯度增强Cosserat连续体细、宏观均匀化方法的广义Hill定理。在梯度增强Cosserat连续体中,不仅宏观样条点上的应变和应力张量,而且它们的梯度均作用于与该样条点相关联的细观表征元(RVE)。依据此广义Hill定理,对梯度增强Cosserat连续体表征元提出了满足Hill—Mandel能量等价条件和平均场理论的强形式及弱形式边界条件。

  12. Clausius/Cosserat/Maxwell/Weyl Equations: The Viral Theorem Revisited

    CERN Document Server

    Pommaret, Jean-François

    2015-01-01

    In 1870, R. Clausius found the virial theorem which amounts to introduce the trace of the stress tensor when studying the foundations of thermodynamics, as a way to relate the absolute temperature of an ideal gas to the mean kinetic energy of its molecules. In 1901, H. Poincar{\\'e} introduced a duality principle in analytical mechanics in order to study lagrangians invariant under the action of a Lie group of transformations. In 1909, the brothers E. and F. Cosserat discovered another approach for studying the same problem though using quite different equations. In 1916, H. Weyl considered again the same problem for the conformal group of transformations, obtaining at the same time the Maxwell equations and an additional specific equation also involving the trace of the impulsion-energy tensor. Finally, having in mind the space-time formulation of electromagnetism and the Maurer-Cartan equations for Lie groups, gauge theory has been created by C.N. Yang and R.L. Mills in 1954 as a way to introduce in physics ...

  13. A model of continuous granular medium. Waves in the reduced Cosserat continuum

    Directory of Open Access Journals (Sweden)

    V.V. Lalin

    2012-08-01

    Full Text Available In the description of vibrational properties of deformable bodies, it is usually assumed that the size of the oscillating particles is negligible in comparison with the average distance between them, so to describe the kinematics of such media only the displacement vector is used. In the majority of work is considered that when the independent rotational degrees of freedom are taken into account it become necessary to introduce the couple stress. Such models of continuous media are well known, for example, moment theory of elasticity or Cosserat media.A distinctive feature of the reduced Cosserat medium is that the stress tensor is asymmetric, and in static problems, this tensor becomes symmetric. Thus, in statics the reduced Cosserat media is indistinguishable from the the classical continuum in which the rotational degrees of freedom are not independent, as they are expressed in terms of displacement and the stress tensor is symmetric.In this paper we investigate the wave motion of a three-dimensional, isotropic, elastic reduced Cosserat medium, the characteristic velocities of wave propagation are finding, we also construct and analyze the dispersion curve for the dynamic equations.

  14. Modeling of the Propagation of Seismic Waves in Non-Classical Media: Reduced Cosserat Continuum

    Science.gov (United States)

    Grekova, E.; Kulesh, M.; Herman, G.; Shardakov, I.

    2006-12-01

    In rock mechanics, elastic wave propagation is usually modeled in terms of classical elasticity. There are situations, however, when rock behaviour is still elastic but cannot be described by the classical model. In particular, current effective medium theories, based on classical elasticity, do not properly describe strong dispersive or attenuative behaviour of wave propagation observed sometimes. The approach we have taken to address this problem is to introduce supplementary and independent degrees of freedom of material particles, in our case rotational ones. Various models of this kind are widely used in continuum mechanics: Cosserat theory, micropolar model of Eringen, Cosserat pseudocontinuum, reduced Cosserat continuum etc. We have considered the reduced Cosserat medium where the couple stress is zero, while the rotation vector is independent of the translational displacement. In this model, the stress depends on the rotation of a particle relatively to the background continuum of mass centers, but it does not depend on the relative rotation of two neighboring particles. This model seems to be adequate for the description of granular media, consolidated soils, and rocks with inhomogeneous microstructure. A real inhomogeneous medium is considered as effective homogeneous enriched continuum, where proper rotational dynamics of inhomogeneities are taken into account by means of rotation of a particle of the enriched continuum. We have obtained and analyzed theoretical solutions for this model describing the propagation of body waves and surface waves. We have shown both the dispersive character of these waves in elastic space and half space, and the existence of forbidden frequency zones. These results can be used for the preparation, execution, and interpretation of seismic experiments, which would allow one to determine whether (and in which situations) polar theories are important in rock mechanics, and to help with the identification of material parameters

  15. A COSSERAT-TYPE PLATE THEORY AND ITS APPLICATION TO CARBON NANOTUBE MICROSTRUCTURE

    Directory of Open Access Journals (Sweden)

    Abdellatif Selmi

    2014-01-01

    Full Text Available The predictive capabilities of plate and shell theories greatly depend on their underlying kinematic assumptions. In this study, we develop a Cosserat-type elastic plate theory which accounts for rotations around the normal to the mid-surface plane (so-called drilling rotations. Internal loads, equilibrium equations, boundary conditions and constitutive equations are derived. The case of a Single Walled carbon Nanotube (SWNT modelled as a Cosserat medium is taken here as a reference example. Material parameters are identified and the proposed theory is used to solve analytically the problem of a polymer-SWNT composite tube under torsion. Predictions such as an absolute size effect are compared to those of the classical Cauchy-de Saint-Venant results.

  16. Surface Waves Properties in Cosserat Continuum: Construction of Solution and Analysis Using Wavelet Transform

    Science.gov (United States)

    Kulesh, M.; Holschneider, M.; Shardakov, I.

    2005-12-01

    The problem of the surface elastic wave propagation in the half-space within the framework of the Cosserat continuum has been considered. Medium deformation in this model is described not only by the displacement vector, but also by kinematically independent rotation vector. This model can be used for the description of the media with microstructure, for example concrete, sand, sandy-gravel mixture etc. At the same time the applications of these models almost do not exist in praxis, since there are no reliable data about the material properties in nonsymmetrical elasticity theory and in fact there are no experiments which can demonstrate the effects of couple-stress behavior in solid under deformation. The main result of presented work consist in fact, that within the framework of the Cosserat continuum in half-space besides elliptical Rayleigh wave can be in existence the surface shear wave with only transversal component. Geometrically such wave is equal to Love wave, but in classical elasticity theory existence of the Love wave as surface elastic wave is defined by presence of a layer on a half-space, and while a layer thickness vanishing the Love wave proceeds to a plane wave. Thus, in Cosserat medium the new wave mode is found out, and there is no analogue of it in classical elasticity theory. As a second result of presented work the method of the displacement seismogram inversion has been proposed. This method is based on continues wavelet transform and allows to restore the wave number, phase and group velocities. These results can be effectively used in possible experiments which are aimed at the detection of couple-stress effects in medium and further at the identification of material constants of nonsymmetrical elasticity theory. This work was supported by Russian Foundation of Fundamental Research under project 03-01-00561 and by the Deutsche Forschungsgemeinschaft (DFG) within the framework of the priority program SPP 1114, Mathematical methods for time

  17. Thermomechanical theory of a Cosserat point with application to composite materials. (Reannouncement with new availability information)

    Energy Technology Data Exchange (ETDEWEB)

    Green, A.E.; Naghdi, P.M.

    1991-12-31

    After presenting a general thermomechanical theory of a Cosserat point with any number of directors in both Lagrangian and Eulerian forms, attention is confined to the development of a system of linearized equations for small deformation of elastic materials under isothermal conditions. With the help of the latter system of equations, several examples of elastic composite materials are discussed. These pertain to extension, torsion and flexure of a right cylinder of arbitrary uniform cross-section reinforced by any number of fillers with different elastic moduli.

  18. Bending of geometrically nonlinear cantilever beam. Results obtained by Cosserat – Timoshenko and Kirchhoff’s rod theories

    Directory of Open Access Journals (Sweden)

    V.V. Lalin

    2015-02-01

    Full Text Available The problem of verification of different program suites for structural analysis has recently become an important component of the construction science. One of the most extensively used benchmark problem is a classical geometrically nonlinear problem of deflection of the cantilever beam of linear elastic material, under the action of external vertical concentrated load at the free end. In fact, the solution for Kirchhoff’s rod is used as an analytical result. This rod is inextensible and Kirchhoff’s rod theory disregards flexibility of the rod in tension and shear. But in modern program suites Cosserat-Timoshenko rod is often used because Cosserat-Timoshenko rod theory is a geometrically exact theory. It considers not only bending strain but also shear and tensile strain. This means that it is necessary to get a model solution for Cosserat – Timoshenko rod, which can be used for verification of different software suites. This paper presents solutions of the geometrically nonlinear problem obtained by Cosserat – Timoshenko and Kirchhoff’s rod theory with comparison of those results. The findings can be used as a benchmark problem for verification of software suites.

  19. Non-classical continuum theory for solids incorporating internal rotations and rotations of Cosserat theories

    Science.gov (United States)

    Surana, K. S.; Joy, A. D.; Reddy, J. N.

    2017-03-01

    This paper presents a non-classical continuum theory in Lagrangian description for solids in which the conservation and the balance laws are derived by incorporating both the internal rotations arising from the Jacobian of deformation and the rotations of Cosserat theories at a material point. In particular, in this non-classical continuum theory, we have (i) the usual displacements ( ±b \\varvec{u}) and (ii) three internal rotations ({}_i ±b \\varvec{Θ}) about the axes of a triad whose axes are parallel to the x-frame arising from the Jacobian of deformation (which are completely defined by the skew-symmetric part of the Jacobian of deformation), and (iii) three additional rotations ({}_e ±b \\varvec{Θ}) about the axes of the same triad located at each material point as additional three degrees of freedom referred to as Cosserat rotations. This gives rise to ±b \\varvec{u} and {}_e ±b \\varvec{{Θ} as six degrees of freedom at a material point. The internal rotations ({}_i ±b \\varvec{Θ}), often neglected in classical continuum mechanics, exist in all deforming solid continua as these are due to Jacobian of deformation. When the internal rotations {}_i ±b \\varvec{Θ} are resisted by the deforming matter, conjugate moment tensor arises that together with {}_i ±b \\varvec{Θ} may result in energy storage and/or dissipation, which must be accounted for in the conservation and the balance laws. The Cosserat rotations {}_e ±b \\varvec{Θ} also result in conjugate moment tensor which, together with {}_e ±b \\varvec{Θ}, may also result in energy storage and/or dissipation. The main focus of the paper is a consistent derivation of conservation and balance laws that incorporate aforementioned physics and associated constitutive theories for thermoelastic solids. The mathematical model derived here has closure, and the constitutive theories derived using two alternate approaches are in agreement with each other as well as with the condition resulting from the

  20. The Armstrong-Frederick cyclic hardening plasticity model with Cosserat effects

    Science.gov (United States)

    Chełmiński, Krzysztof; Neff, Patrizio; Owczarek, Sebastian

    We propose an extension of the cyclic hardening plasticity model formulated by Armstrong and Frederick which includes micropolar effects. Our micropolar extension establishes coercivity of the model which is otherwise not present. We study then existence of solutions to the quasistatic, rate-independent Armstrong-Frederick model with Cosserat effects which is, however, still of non-monotone, non-associated type. In order to do this, we need to relax the pointwise definition of the flow rule into a suitable weak energy-type inequality. It is shown that the limit in the Yosida approximation process satisfies this new solution concept. The limit functions have a better regularity than previously known in the literature, where the original Armstrong-Frederick model has been studied.

  1. Poincaré's Equations for Cosserat Media: Application to Shells

    Science.gov (United States)

    Boyer, Frederic; Renda, Federico

    2017-02-01

    In 1901, Henri Poincaré discovered a new set of equations for mechanics. These equations are a generalization of Lagrange's equations for a system whose configuration space is a Lie group which is not necessarily commutative. Since then, this result has been extensively refined through the Lagrangian reduction theory. In the present contribution, we apply an extended version of these equations to continuous Cosserat media, i.e. media in which the usual point particles are replaced by small rigid bodies, called microstructures. In particular, we will see how the shell balance equations used in nonlinear structural dynamics can be easily deduced from this extension of the Poincaré's result. In future, these results will be used as foundations for the study of squid locomotion, which is an emerging topic relevant to soft robotics.

  2. Linear reduced cosserat medium with spherical tensor of inertia, where rotations are not observed in experiment

    Science.gov (United States)

    Grekova, E. F.

    2012-09-01

    We consider a linear reduced Cosserat medium: a linear elastic continuum, whose point bodies possess kinematically independent translational and rotational degrees of freedom, but the strain energy does not depend on the gradient of rotation of particles. In such a medium the force stress tensor is asymmetric, but the couple stress tensor is zero. This model can be applied for description of soils and granular media. Since for the time being the experimental technique for measurement of rotational deformations is not well developed, we investigate how the presence of rotational degrees of freedom affects the dynamics of translational displacements. We consider the case of the spherical tensor of inertia and isotropy with respect to the rotational degrees of freedom. Integration of the equation of balance of torques lets us in several cases to put in correspondence a linear reduced Cosserat continuum with the spherical tensor of inertia with a classical (non-polar elastic linear) medium with memory with the same equation for the balance of forces, written in terms of translational displacements. This is possible for the isotropic case and also if the anisotropy is present only in the tensor of elastic constants corresponding to the classical strain tensor. If the material is isotropic with respect to rotational deformations but the (anisotropic) coupling between rotational and classical translational strains is present, then the corresponding classical medium does not exist. If we ignore the rotational degrees of freedom when this coupling is present, this will lead us to the conclusion that the principle of material objectivity is violated.

  3. Analysis of Blood Flow Through a Viscoelastic Artery using the Cosserat Continuum with the Large-Amplitude Oscillatory Shear Deformation Model

    DEFF Research Database (Denmark)

    Sedaghatizadeh, N.; Atefi, G.; Fardad, A. A.

    2011-01-01

    In this investigation, semiempirical and numerical studies of blood flow in a viscoelastic artery were performed using the Cosserat continuum model. The large-amplitude oscillatory shear deformation model was used to quantify the nonlinear viscoelastic response of blood flow. The finite differenc...

  4. The relaxed-polar mechanism of locally optimal Cosserat rotations for an idealized nanoindentation and comparison with 3D-EBSD experiments

    Science.gov (United States)

    Fischle, Andreas; Neff, Patrizio; Raabe, Dierk

    2017-08-01

    The rotation {{polar}}(F) \\in {{SO}}(3) arises as the unique orthogonal factor of the right polar decomposition F = {{polar}}(F) U of a given invertible matrix F \\in {{GL}}^+(3). In the context of nonlinear elasticity Grioli (Boll Un Math Ital 2:252-255, 1940) discovered a geometric variational characterization of {{polar}}(F) as a unique energy-minimizing rotation. In preceding works, we have analyzed a generalization of Grioli's variational approach with weights (material parameters) μ > 0 and μ _c \\ge 0 (Grioli: μ = μ _c). The energy subject to minimization coincides with the Cosserat shear-stretch contribution arising in any geometrically nonlinear, isotropic and quadratic Cosserat continuum model formulated in the deformation gradient field F :=\

  5. Numerical treatment of cosserat based rate independent strain gradient plasticity theories Tratamiento numérico de una teoría de plasticidad por gradiente de deformación basada en un modelo de cosserat

    Directory of Open Access Journals (Sweden)

    Juan David Gómez C.

    2008-12-01

    Full Text Available The current trend towards miniaturization in the microelectronics industryhas pushed for the development of theories intended to explain the behaviorof materials at small scales. In the particular case of metals, a class ofavailable non–classical continuum mechanics theories has been recently employedin order to explain the wide range of observed behavior at the micronscale. The practical use of the proposed theories remains limited due to issuesin its numerical implementation. First, in displacement–based finite elementformulations the need appears for higher orders of continuity in the interpolationshape functions in order to maintain the convergence rate upon meshrefinement. This limitation places strong restrictions in the geometries of theavailable elements. Second, the available inelastic constitutive models for smallscale applications have been cast into deformation theory formulations limitingthe set of problems to those exhibiting proportional loading only. In thisarticle two contributions are made for the particular case of a Cosserat couplestress continuum. First it describes a numerical scheme based on a penaltyfunction/reduced integration approach that allows for the proper treatment ofthe higher order terms present in Cosserat like theories. This scheme results in a new finite element that can be directly implemented into commercial finiteelement codes. Second, a flow theory of plasticity incorporating size effects isproposed for the case of rate independent materials overcoming the limitationsin the deformation theory formulations. The constitutive model and its correspondingtime–integration algorithm are coupled to the new proposed finiteelement and implemented in the form of a user element subroutine into thecommercial code ABAQUS. The validity of the approach is shown via numericalsimulations of the microbending experiment on thin Nickel foils reportedin the literature.La tendencia actual hacia la miniaturización en la

  6. Analysis of blood flow through a viscoelastic artery using the Cosserat continuum with the large-amplitude oscillatory shear deformation model.

    Science.gov (United States)

    Sedaghatizadeh, N; Atefi, G; Fardad, A A; Barari, A; Soleimani, Soheil; Khani, S

    2011-10-01

    In this investigation, semiempirical and numerical studies of blood flow in a viscoelastic artery were performed using the Cosserat continuum model. The large-amplitude oscillatory shear deformation model was used to quantify the nonlinear viscoelastic response of blood flow. The finite difference method was used to solve the governing equations, and the particle swarm optimization algorithm was utilized to identify the non-Newtonian coefficients (k(υ) and γ(υ)). The numerical results agreed well with previous experimental results. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. PARAMETRIC VARIATIONAL PRINCIPLE BASED ELASTIC-PLASTIC ANALYSIS AND STRAIN LOCALIZATION SIMULATION OF 3D COSSERAT CONTINUUM MODEL%基于参变量变分原理的三维Cosserat体模型弹塑性分析与应变局部化模拟

    Institute of Scientific and Technical Information of China (English)

    解兆谦; 张洪武; 陈飙松

    2012-01-01

    Based on the parametric variational principle, a quadratic programming method is developed for the elastic-plastic finite element analysis of a 3D Cosserat continuum model. Since the classical continuum model which is lack of internal scale parameter suffers from pathological mesh dependence in the strain localization analysis, the governing equations of the Cosserat continuum model are regularized by adding a rotational degrees-of-freedom and internal scale parameters to the conventional continuum model. Numerical examples are calculated to demonstrate the efficiency of the 3D Cosserat finite element model and the stability of the proposed computational algorithm for numerical simulation of strain localization problems. Particularly, the mesh independent results are ensured.%基于参变量变分原理,该文发展了三维Cosserat连续体模型弹塑性有限元分析的二次规划算法。由于Cosserat连续体模型的本构方程中存在材料内尺度参数,该模型可以解决经典连续介质理论在分析应变软化问题时病态的有限元网格依赖性问题。数值结果表明所发展的三维Cosserat连续介质弹塑性有限元模型可以有效的模拟应变局部化现象并且该算法具有很好的数值稳定性,同时获得的数值结果具有良好的非网格依赖性。

  8. Micro Engineering

    DEFF Research Database (Denmark)

    Alting, Leo; Kimura, F.; Hansen, Hans Nørgaard

    2003-01-01

    The paper addresses the questions of how micro products are designed and how they are manufactured. Definitions of micro products and micro engineering are discussed and the presentation is aimed at describing typical issues, possibilities and tools regarding design of micro products. The implica......The paper addresses the questions of how micro products are designed and how they are manufactured. Definitions of micro products and micro engineering are discussed and the presentation is aimed at describing typical issues, possibilities and tools regarding design of micro products...

  9. 离散颗粒集合体-Cosserat连续体模型的连接尺度方法%Bridging scale method for discrete particle assembly-Cosserat continuum modeling

    Institute of Scientific and Technical Information of China (English)

    万柯; 李锡夔

    2012-01-01

    On the basis of the bridging scale method (BSM) initially proposed for molecular dynamics- Cauchy continuum modeling , a new version of the BSM that couples the discrete particle assembly model using the discrete element method (DEM) and the Cosserat continuum model using the finite ele- ment method (FEM) in fine and coarse scales respectively is presented. The present BSM applies the DEM only to limited local regions of the whole computational domain for the purpose of accurate simula- tion of material failure with discontinuous deformation characteristics in microscopic scale,and meantime applies the FEM that costs much less both computational time and storage space to the whole domain. In addition,different time step sizes are allowed to the time integration schemes used to the coarse and fine scales respectively,as a consequence, both computational accuracy and efficiency of the present BSM is greatly enhanced. With the coarse and fine scale decomposition of translational and rotational displace- ments,in light of the principle of virtual work applied to the FEM nodes of Cosserat continuum and the particle centers of discrete particle assembly respectively, two decoupling sets of equations of motion of the combined coarse-fine scale system are derived. The interfacial condition between coarse and fine do- mains in the case of quasi-static loading,and the non-reflecting boundary condition (NRBC), which is ca- pable of effectively eliminating spurious reflective waves at the interface between coarse and fine domains under dynamic loads are presented and discussed. The numerical results for 2D example problems illus- trate the applicability and advantages of the present BSM,as well as the availability of the proposed in- terfacial condition for dynamical response simulations of granular materials.%基于针对分子动力学-Cauchy连续体模型提出的连接尺度方法(BSM)[1,2],发展了耦合细尺度上基于离散颗粒集合体模型

  10. Micro Engineering

    DEFF Research Database (Denmark)

    Alting, Leo; Kimura, F.; Hansen, Hans Nørgaard

    2003-01-01

    The paper addresses the questions of how micro products are designed and how they are manufactured. Definitions of micro products and micro engineering are discussed and the presentation is aimed at describing typical issues, possibilities and tools regarding design of micro products. The implica...

  11. Micro Vision

    OpenAIRE

    Ohba, Kohtaro; OHARA, Kenichi

    2007-01-01

    In the field of the micro vision, there are few researches compared with macro environment. However, applying to the study result for macro computer vision technique, you can measure and observe the micro environment. Moreover, based on the effects of micro environment, it is possible to discovery the new theories and new techniques.

  12. Micro Manufacturing

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard

    2003-01-01

    . If a micro manufacturing system isn’t designed rationally and correctly, it will be high-cost, unreliable, and not robust. For micro products and systems it is a continuously increasing challenge to create the operational basis for an industrial production. As the products through product development...... processes are made applicable to a large number of customers, the pressure in regard to developing production technologies that make it possible to produce the products at a reasonable price and in large numbers is growing. The micro/nano manufacturing programme at the Department of Manufacturing...

  13. Micro Manufacturing

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard

    2003-01-01

    Manufacturing deals with systems that include products, processes, materials and production systems. These systems have functional requirements, constraints, design parameters and process variables. They must be decomposed in a systematic manner to achieve the best possible system performance....... If a micro manufacturing system isn’t designed rationally and correctly, it will be high-cost, unreliable, and not robust. For micro products and systems it is a continuously increasing challenge to create the operational basis for an industrial production. As the products through product development...... processes are made applicable to a large number of customers, the pressure in regard to developing production technologies that make it possible to produce the products at a reasonable price and in large numbers is growing. The micro/nano manufacturing programme at the Department of Manufacturing...

  14. Micro Marketing

    Institute of Scientific and Technical Information of China (English)

    Yu Yan

    2012-01-01

    In November the Chinese movie industry experienced a startling surprise.Love Is Not Blind,a low-budget movie with no prominent director or major star,hit 344.8million yuan ($54.5 million) in box office revenue,despite the film's budget was only 9 million yuan ($1.4 million).The film,which tells the 33-day experience of a girl named Huang Xiaoxian after she breaks up with her boyfriend,owes its unexpected blockbusting success to its innovative marketing strategy:micro-blog marketing.The number of followers of the official micro-blog for Love Is Not Blind hit nearly 100,000,attracted by rccommendations of related micro-blog messages,impressive box office lines,and positive word of mouth.By December 7,search queries for Love Is Not Blind had exceeded 8 million.Those for Wang Xiaojian,the lcading male,were close to 1.5 million.

  15. Micro club

    CERN Multimedia

    Micro club

    2014-01-01

    Opération NEMO   Pour finir en beauté les activités spéciales que le CMC a réalisé pendant cette année 2014, pour commémorer le 60ème anniversaire du CERN, et le 30ème du Micro Club, l’ Opération NEMO aura cette année un caractère très particulier. Nous allons proposer 6 fabricants de premier ordre qui offriront chacun deux ou trois produits à des prix exceptionnels. L’opération débute le lundi 17 novembre 2014. Elle se poursuivra  jusqu’au samedi 6 décembre inclus. Les délais de livraison seront de deux à trois semaines, selon les fabricants. Donc les commandes faites la dernière semaine, du 1 au 6 décembre, risquent d’arriver qu'au début du mois de janvier 2015. Liste de fabricants part...

  16. Micro club

    CERN Multimedia

    Micro Club

    2014-01-01

    Jeudi 18 septembre 2014 à 18h30 au Bât. 567 R-029 Le CERN MICRO CLUB organise un Atelier sur la sécurité informatique. La Cyber-sécurité : Ce qui se passe vraiment, comment ne pas en être victime ! Orateur : Sebastian Lopienski Adjoint au Computer Security Officer du Département IT. Sujet : Cet exposé vous présentera les modes de sécurité actuels et les problèmes touchants les applications logicielles des ordinateurs, les réseaux ainsi que leurs utilisateurs. Cela inclus des informations sur les nouveaux types de vulnérabilité, les vecteurs d'attaque récents et une vue d'ensemble sur le monde de la cyber-sécurité en 2014. Biographie : Sebastian Lopienski travaille au CERN depuis 2001. Il est actuellement adjoint au Computer Security Officer et s'occupe de la protection de...

  17. Micro-propulsion and micro-combustion; Micropropulsion microcombustion

    Energy Technology Data Exchange (ETDEWEB)

    Ribaud, Y.; Dessornes, O.

    2002-10-01

    The AAAF (french space and aeronautic association) organized at Paris a presentation on the micro-propulsion. The first part was devoted to the thermal micro-machines for micro drones, the second part to the micro-combustion applied to micro-turbines. (A.L.B.)

  18. Micro-Organ Device

    Science.gov (United States)

    Gonda, Steve R. (Inventor); Chang, Robert C. (Inventor); Starly, Binil (Inventor); Culbertson, Christopher (Inventor); Holtorf, Heidi L. (Inventor); Sun, Wei (Inventor); Leslie, Julia (Inventor)

    2013-01-01

    A method for fabricating a micro-organ device comprises providing a microscale support having one or more microfluidic channels and one or more micro-chambers for housing a micro-organ and printing a micro-organ on the microscale support using a cell suspension in a syringe controlled by a computer-aided tissue engineering system, wherein the cell suspension comprises cells suspended in a solution containing a material that functions as a three-dimensional scaffold. The printing is performed with the computer-aided tissue engineering system according to a particular pattern. The micro-organ device comprises at least one micro-chamber each housing a micro-organ; and at least one microfluidic channel connected to the micro-chamber, wherein the micro-organ comprises cells arranged in a configuration that includes microscale spacing between portions of the cells to facilitate diffusion exchange between the cells and a medium supplied from the at least one microfluidic channel.

  19. Search for Bs0 --> micro+ micro- and B0 --> micro+ micro- decays with 2 fb-1 of pp collisions.

    Science.gov (United States)

    Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Bednar, P; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'orso, M; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Genser, K; Gerberich, H; Gerdes, D; Giagu, S; Giakoumopolou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Koay, S A; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lu, R-S; Lucchesi, D; Lueck, J; Luci, C; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moed, S; Moggi, N; Moon, C S; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyria, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner-Kuhr, J; Wagner, W; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zheng, Y; Zucchelli, S

    2008-03-14

    We have performed a search for B(s)(0) --> micro(+) micro(-) and B(0) --> micro(+) micro(-) decays in pp collisions at square root s = 1.96 TeV using 2 fb(-1) of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron Collider. The observed number of B(s)(0) and B0 candidates is consistent with background expectations. The resulting upper limits on the branching fractions are B(B(s)0) --> micro(+) micro(-)) micro(+) micro(-))<1.8 x 10(-8) at 95% C.L.

  20. MicroRNAs

    DEFF Research Database (Denmark)

    Devaux, Yvan; Stammet, Pascal; Friberg, Hans

    2015-01-01

    cardiac arrest would allow subsequent health care delivery to be tailored to individual patients. However, currently available predictive methods and biomarkers lack sufficient accuracy and therefore cannot be generally recommended in clinical practice. MicroRNAs have recently emerged as potential...... biomarkers of cardiovascular diseases. While the biomarker value of microRNAs for myocardial infarction or heart failure has been extensively studied, less attention has been devoted to their prognostic value after cardiac arrest. This review highlights the recent discoveries suggesting that microRNAs may...

  1. microRNA

    OpenAIRE

    Xin, Xiong; Ning, Zhou

    2007-01-01

    MicroRNAs (miRNAs) are short, 20-22 nucleotide RNA molecules that function as negative regulators of gene expression in eukaryotic organisms. RNA mediated gene silencing pathways have essential roles in development, cell differentiation, proliferation, and cell death. It is becoming clear that microRNAs can play a very important role in regulation of gene expression. Understanding the basic mechanism of miRNA biogenesis is one of the central aims of molecular biologists in the future. MicroRN...

  2. Micro metal forming

    CERN Document Server

    2013-01-01

    Micro Metal Forming, i. e. forming of parts and features with dimensions below 1 mm, is a young area of research in the wide field of metal forming technologies, expanding the limits for applying metal forming towards micro technology. The essential challenges arise from the reduced geometrical size and the increased lot size. In order to enable potential users to apply micro metal forming in production, information about the following topics are given: tribological behavior: friction between tool and work piece as well as tool wear mechanical behavior: strength and formability of the work piece material, durability of the work pieces size effects: basic description of effects occurring due to the fact, that the quantitative relation between different features changes with decreasing size process windows and limits for forming processes tool making methods numerical modeling of processes and process chains quality assurance and metrology All topics are discussed with respect to the questions relevant to micro...

  3. Micro-surgical endodontics.

    Science.gov (United States)

    Eliyas, S; Vere, J; Ali, Z; Harris, I

    2014-02-01

    Non-surgical endodontic retreatment is the treatment of choice for endodontically treated teeth with recurrent or residual disease in the majority of cases. In some cases, surgical endodontic treatment is indicated. Successful micro-surgical endodontic treatment depends on the accuracy of diagnosis, appropriate case selection, the quality of the surgical skills, and the application of the most appropriate haemostatic agents and biomaterials. This article describes the armamentarium and technical procedures involved in performing micro-surgical endodontics to a high standard.

  4. Micro Calorimeter for Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Santhanagopalan, Shriram [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-01

    As battery technology forges ahead and consumer demand for safer, more affordable, high-performance batteries grows, the National Renewable Energy Laboratory (NREL) has added a patented Micro Calorimeter to its existing family of R&D 100 Award-winning Isothermal Battery Calorimeters (IBCs). The Micro Calorimeter examines the thermal signature of battery chemistries early on in the design cycle using popular coin cell and small pouch cell designs, which are simple to fabricate and study.

  5. Micro-Discharge Micro-Thruster

    Science.gov (United States)

    2005-06-01

    breakdown at the maximum applied voltage (900 V) in Argon. The back side of the Paschen curve for Ar occurs at a pressure-length (P·d) product of less than...significant capacitance to ground from either lead (~ 100 nF). As small as this is, it had a profound effect on the discharge (see next section). A more space... effect in most thrusters even in the 100 Watt class. For a micro-discharge, even a stray coupling capacitance 50 pF observed for the power leads

  6. Sustainable Micro-Manufacturing of Micro-Components via Micro Electrical Discharge Machining

    OpenAIRE

    Valeria Marrocco; Giacomo Copani; Irene Fassi; Francesco Modica

    2011-01-01

    Micro-manufacturing emerged in the last years as a new engineering area with the potential of increasing peoples’ quality of life through the production of innovative micro-devices to be used, for example, in the biomedical, micro-electronics or telecommunication sectors. The possibility to decrease the energy consumption makes the micro-manufacturing extremely appealing in terms of environmental protection. However, despite this common belief that the micro-scale implies a higher sustainabil...

  7. Micro-robotics; La microrobotique

    Energy Technology Data Exchange (ETDEWEB)

    Bourjault, A.; Chaillet, N.

    2002-07-01

    The aim of micro-robotics is to study, design, realize and control micro-robots. The underlying scientifical problems concern the miniaturization, the design and control of these micro-robots which requires a strongly pluri-disciplinary approach. In the micro-world, the classical laws of physics cannot be applied in the same way as in the macro-world: forces usually negligible, like the adhesion, electrostatic, Van der Waals forces etc.. have a considerable effect and influence at these scales and are not easily taken into consideration in models. Thus such models of micro-robots are difficult to build and are in general incomplete. The dynamical behaviour of all the components is strongly non-linear and requires adapted control laws. Thus the experimental approach is of prime importance in order to completely reanalyze the main functions of the robot: locomotion, gripping, manipulation. The scientifical problem comprises several aspects and refers to several scientific communities. Among these aspects, this book has retained the essential ones: the miniaturization, the design and the control. Content: 1 - the problems of micro-robotics; 2 - the state-of-the-art; 3 - micro-technologies; 4 - micro-actuators; 5 - micro-actuators in shape memory alloys for micro-robotics; 6 - piezoelectric micro-actuators; 7 - micro-gripping and micro-manipulation; 8 - distributed micro-robots based on silicon technology. (J.S.)

  8. Micro scanning probes

    CERN Document Server

    Niblock, T

    2001-01-01

    This thesis covers the design methodology, theory, modelling, fabrication and evaluation of a Micro-Scanning-Probe. The device is a thermally actuated bimorph quadrapod fabricated using Micro Electro Mechanical Systems technology. A quadrapod is a structure with four arms, in this case a planar structure with the four arms forming a cross which is dry etched out of a silicon diaphragm. Each arm has a layer of aluminium deposited on it forming a bimorph. Through heating each arm actuation is achieved in the plane of the quadrapod and the direction normal to it. Fabrication of the device has required the development of bulk micromachining techniques to handle post CMOS fabricated wafers and the patterning of thickly sputtered aluminium in bulk micro machined cavities. CMOS fabrication techniques were used to incorporate diodes onto the quadrapod arms for temperature measurement of the arms. Fine tungsten and silicon tips have also been fabricated to allow tunnelling between the tip and the platform at the centr...

  9. Monolithic MACS micro resonators

    Science.gov (United States)

    Lehmann-Horn, J. A.; Jacquinot, J.-F.; Ginefri, J. C.; Bonhomme, C.; Sakellariou, D.

    2016-10-01

    Magic Angle Coil Spinning (MACS) aids improving the intrinsically low NMR sensitivity of heterogeneous microscopic samples. We report on the design and testing of a new type of monolithic 2D MACS resonators to overcome known limitations of conventional micro coils. The resonators' conductors were printed on dielectric substrate and tuned without utilizing lumped element capacitors. Self-resonance conditions have been computed by a hybrid FEM-MoM technique. Preliminary results reported here indicate robust mechanical stability, reduced eddy currents heating and negligible susceptibility effects. The gain in B1 /√{ P } is in agreement with the NMR sensitivity enhancement according to the principle of reciprocity. A sensitivity enhancement larger than 3 has been achieved in a monolithic micro resonator inside a standard 4 mm rotor at 500 MHz. These 2D resonators could offer higher performance micro-detection and ease of use of heterogeneous microscopic substances such as biomedical samples, microscopic specimens and thin film materials.

  10. Silicon micro-mold

    Science.gov (United States)

    Morales, Alfredo M.

    2006-10-24

    The present invention describes a method for rapidly fabricating a robust 3-dimensional silicon-mold for use in preparing complex metal micro-components. The process begins by depositing a conductive metal layer onto one surface of a silicon wafer. A thin photoresist and a standard lithographic mask are then used to transfer a trace image pattern onto the opposite surface of the wafer by exposing and developing the resist. The exposed portion of the silicon substrate is anisotropically etched through the wafer thickness down to conductive metal layer to provide an etched pattern consisting of a series of rectilinear channels and recesses in the silicon which serve as the silicon micro-mold. Microcomponents are prepared with this mold by first filling the mold channels and recesses with a metal deposit, typically by electroplating, and then removing the silicon micro-mold by chemical etching.

  11. Micro-machining.

    Science.gov (United States)

    Brinksmeier, Ekkard; Preuss, Werner

    2012-08-28

    Manipulating bulk material at the atomic level is considered to be the domain of physics, chemistry and nanotechnology. However, precision engineering, especially micro-machining, has become a powerful tool for controlling the surface properties and sub-surface integrity of the optical, electronic and mechanical functional parts in a regime where continuum mechanics is left behind and the quantum nature of matter comes into play. The surprising subtlety of micro-machining results from the extraordinary precision of tools, machines and controls expanding into the nanometre range-a hundred times more precise than the wavelength of light. In this paper, we will outline the development of precision engineering, highlight modern achievements of ultra-precision machining and discuss the necessity of a deeper physical understanding of micro-machining.

  12. Tunable micro-optics

    CERN Document Server

    Duppé, Claudia

    2015-01-01

    Presenting state-of-the-art research into the dynamic field of tunable micro-optics, this is the first book to provide a comprehensive survey covering a varied range of topics including novel materials, actuation concepts and new imaging systems in optics. Internationally renowned researchers present a diverse range of chapters on cutting-edge materials, devices and subsystems, including soft matter, artificial muscles, tunable lenses and apertures, photonic crystals, and complete tunable imagers. Special contributions also provide in-depth treatment of micro-optical characterisation, scanners, and the use of natural eye models as inspiration for new concepts in advanced optics. With applications extending from medical diagnosis to fibre telecommunications, Tunable Micro-optics equips readers with a solid understanding of the broader technical context through its interdisciplinary approach to the realisation of new types of optical systems. This is an essential resource for engineers in industry and academia,...

  13. Methods and systems for micro machines

    Science.gov (United States)

    Stalford, Harold L.

    2017-04-11

    A micro machine may be in or less than the micrometer domain. The micro machine may include a micro actuator and a micro shaft coupled to the micro actuator. The micro shaft is operable to be driven by the micro actuator. A tool is coupled to the micro shaft and is operable to perform work in response to at least motion of the micro shaft.

  14. Method of fabricating a micro machine

    Science.gov (United States)

    Stalford, Harold L

    2014-11-11

    A micro machine may be in or less than the micrometer domain. The micro machine may include a micro actuator and a micro shaft coupled to the micro actuator. The micro shaft is operable to be driven by the micro actuator. A tool is coupled to the micro shaft and is operable to perform work in response to at least motion of the micro shaft.

  15. Micro-RNAs

    DEFF Research Database (Denmark)

    Taipaleenmäki, H.; Hokland, L. B.; Chen, Li

    2012-01-01

    Osteoblast differentiation and bone formation (osteogenesis) are regulated by transcriptional and post-transcriptional mechanisms. Recently, a novel class of regulatory factors termed microRNAs has been identified as playing an important role in the regulation of many aspects of osteoblast biology...... including proliferation, differentiation, metabolism and apoptosis. Also, preliminary data from animal disease models suggest that targeting miRNAs in bone can be a novel approach to increase bone mass. This review highlights the current knowledge of microRNA biology and their role in bone formation...

  16. Micro energy harvesting

    CERN Document Server

    Briand, Danick; Roundy, Shad

    2015-01-01

    With its inclusion of the fundamentals, systems and applications, this reference provides readers with the basics of micro energy conversion along with expert knowledge on system electronics and real-life microdevices. The authors address different aspects of energy harvesting at the micro scale with a focus on miniaturized and microfabricated devices. Along the way they provide an overview of the field by compiling knowledge on the design, materials development, device realization and aspects of system integration, covering emerging technologies, as well as applications in power management, e

  17. Lectures in Micro Meteorology

    DEFF Research Database (Denmark)

    Larsen, Søren Ejling

    This report contains the notes from my lectures on Micro scale meteorology at the Geophysics Department of the Niels Bohr Institute of Copenhagen University. In the period 1993-2012, I was responsible for this course at the University. At the start of the course, I decided that the text books...... available in meteorology at that time did not include enough of the special flavor of micro meteorology that characterized the work of the meteorology group at Risø (presently of the Institute of wind energy of the Danish Technical University). This work was focused on Boundary layer flows and turbulence...

  18. MicroCulture

    DEFF Research Database (Denmark)

    Marchetti, Emanuela

    2012-01-01

    This paper proposes a playful learning scenario, to enhance children’s museum experience, and the design of MicroCulture, a new learning platform. MicroCulture has been developed through a participatory design process, involving around 25 children. The perspective proposed in this paper is focused...... on enhancing existing storytelling practices, so to provide a more tangible grounding to the communication of historical processes and to elicit a lively dialogue between children and guides. In this perspective, it is proposed to turn storytelling, as a museum learning practice, into a more dialogic...

  19. Micro-Scale Thermoacoustics

    Science.gov (United States)

    Offner, Avshalom; Ramon, Guy Z.

    2016-11-01

    Thermoacoustic phenomena - conversion of heat to acoustic oscillations - may be harnessed for construction of reliable, practically maintenance-free engines and heat pumps. Specifically, miniaturization of thermoacoustic devices holds great promise for cooling of micro-electronic components. However, as devices size is pushed down to micro-meter scale it is expected that non-negligible slip effects will exist at the solid-fluid interface. Accordingly, new theoretical models for thermoacoustic engines and heat pumps were derived, accounting for a slip boundary condition. These models are essential for the design process of micro-scale thermoacoustic devices that will operate under ultrasonic frequencies. Stability curves for engines - representing the onset of self-sustained oscillations - were calculated with both no-slip and slip boundary conditions, revealing improvement in the performance of engines with slip at the resonance frequency range applicable for micro-scale devices. Maximum achievable temperature differences curves for thermoacoustic heat pumps were calculated, revealing the negative effect of slip on the ability to pump heat up a temperature gradient. The authors acknowledge the support from the Nancy and Stephen Grand Technion Energy Program (GTEP).

  20. Tolerances in micro manufacturing

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; Zhang, Yang; Islam, Aminul

    2017-01-01

    This paper describes a method for analysis of tolerances in micro manufacturing. It proposes a mapping oftolerances to dimensions and compares this with current available international standards. The analysisdocuments that tolerances are not scaled down as the absolute dimension. In practice...

  1. Programming the BBC micro

    CERN Document Server

    Ferguson, John D; Macari, Louie; Williams, Peter H

    1983-01-01

    Programming the BBC Micro is a 12-chapter book that begins with a description of the BBC microcomputer, its peripheral, and faults. Subsequent chapters focus on practice in programming, program development, graphics, words, numbers, sound, bits, bytes, and assembly language. The interfacing, file handling, and detailed description of BBC microcomputer are also shown.

  2. Phase separation micro molding

    NARCIS (Netherlands)

    Vogelaar, Laura

    2005-01-01

    The research described in this thesis concerns the development of a new microfabrication method, Phase Separation Micro Molding (PSμM). While microfabrication is still best known from semiconductor industry, where it is used to integrate electrical components on a chip, the scope has immensely expan

  3. Micro Mobility Marketing

    DEFF Research Database (Denmark)

    Hosbond, Jens Henrik; Skov, Mikael B.

    2008-01-01

    and differences between micro mobility marketing and the traditional mobile marketing in the large. Finally, we suggest areas for further study.Journal of Targeting, Measurement and Analysis for Marketing (2007) 16, 68-77. doi:10.1057/palgrave.jt.5750058; published online 24 December 2007...

  4. Micro-hydro power

    Energy Technology Data Exchange (ETDEWEB)

    Fraenkel, P.; Paish, O. (IT Power, Eversley (United Kingdom)); Harvey, A.; Brown, A.; Edwards, R. (Intermediate Technology Development Group Ltd., Rugby (GB)); Bokalders, V. (Stockholm Environment Inst. (SE))

    1991-01-01

    This guide is specifically addressed to the practical needs of development workers. An overview of micro-hydro is given, and preliminary studies are discussed. Hydrology and site surveys are considered and civil works, penstocks, turbines, governing, drive systems, electrical power, basic economics, commissioning and testing, and operation and maintenance are reviewed in detail. (U.K.).

  5. Micro- and Nanoengineering

    NARCIS (Netherlands)

    Schroen, C.G.P.H.

    2015-01-01

    There are two overall themes, micro- and nanotechnology, which are capable of changing the future of food considerably. In microtechnology, production of foods and food ingredients is investigated at small scale; the results are thus that larger scale production is considered through operating many

  6. Micro-PROUST.

    Science.gov (United States)

    Johnson, W. Lewis; Soloway, Elliot

    This detailed description of a microcomputer version of PROUST (Program Understander for Students), a knowledge-based system that finds nonsyntactic bugs in Pascal programs written by novice programmers, presents the inner workings of Micro-PROUST, which was written in Golden LISP for the IBM-PC (512K). The contents include: (1) a reprint of an…

  7. Cold Gas Micro Propulsion

    NARCIS (Netherlands)

    Louwerse, M.C.

    2009-01-01

    This thesis describes the development of a micro propulsion system. The trend of miniaturization of satellites requires small sized propulsion systems. For particular missions it is important to maintain an accurate distance between multiple satellites. Satellites drift apart due to differences in

  8. SCALE EFFECT ANALYSIS FOR THE VIBRO-ACOUSTIC PERFORMANCE OF A MICRO-PLATE%MEMS系统中微平板结构声振耦合性能研究

    Institute of Scientific and Technical Information of China (English)

    唐宇帆; 任树伟; 辛锋先; 卢天健

    2016-01-01

    Micro electromechanical system (MEMS) is an electromechanical device of microscale, in which micro-plate is the most typical structure. Its acoustical and mechanical properties influence the design of MEMS significantly. The vibroacoustic performance of simply supported micro-plate subjected to simultaneous stimulation of sound pressure and gas film (squeeze film) damping force is analyzed theoretically, the latter induced by the vibration of a micro-plate having similar size. By applying the Cosserat theory and the Hamilton principle, micro scale effects due to characteristic length and Knudsen number are taken into account. The governing equations are subsequently solved using the method of multiple Fourier transform to quantify sound transmission loss (STL) across the micro-plate. In the frequency domain, the effects of squeeze film under different circumstances (e.g., different characteristic lengths and Knudsen numbers, different vibration frequencies and amplitudes) on STL are investigated systematically. This work demonstrates the great influence of micro-scale effects, as well as vibration, on STL. Decreasing the vibration amplitude and increasing the distance between micro-plates lead to better performance of sound transmission. Results presented in this study provide useful theoretical guidance to the practical design of micro-plates in MEMS.%微机电系统(micro-electro-mechanical system,MEMS)是指内部微结构尺寸在微米甚至纳米量级的微电子机械装置,是一个独立的智能系统。长宽厚均处于微米量级的微平板为MEMS中的典型结构,其声学和力学特性直接影响MEMS的性能。针对同时受声压激励和气膜力(通过考虑相同尺寸微平板振动引入)作用的四边简支微平板结构,应用Cosserat理论和Hamilton原理,建立了考虑微尺度效应(本征长度和Knudsen数)影响的声振耦合理论模型,并通过多重Fourier展开法求解了耦合方程,得到了系统的

  9. Sparse Reconstruction for Micro Defect Detection in Acoustic Micro Imaging.

    Science.gov (United States)

    Zhang, Yichun; Shi, Tielin; Su, Lei; Wang, Xiao; Hong, Yuan; Chen, Kepeng; Liao, Guanglan

    2016-10-24

    Acoustic micro imaging has been proven to be sufficiently sensitive for micro defect detection. In this study, we propose a sparse reconstruction method for acoustic micro imaging. A finite element model with a micro defect is developed to emulate the physical scanning. Then we obtain the point spread function, a blur kernel for sparse reconstruction. We reconstruct deblurred images from the oversampled C-scan images based on l₁-norm regularization, which can enhance the signal-to-noise ratio and improve the accuracy of micro defect detection. The method is further verified by experimental data. The results demonstrate that the sparse reconstruction is effective for micro defect detection in acoustic micro imaging.

  10. Micro Embossing of Ceramic Green Substrates for Micro Devices

    CERN Document Server

    Shan, X -C; Maw, H P; Lu, C W; Lam, Y C

    2008-01-01

    Multilayered ceramic substrates with embedded micro patterns are becoming increasingly important, for example, in harsh environment electronics and microfluidic devices. Fabrication of these embedded micro patterns, such as micro channels, cavities and vias, is a challenge. This study focuses on the process of patterning micro features on ceramic green substrates using micro embossing. A ceramic green tape that possessed near-zero shrinkage in the x-y plane was used, six layers of which were laminated as the embossing substrate. The process parameters that impact on the pattern fidelity were investigated and optimized in this study. Micro features with line-width as small as several micrometers were formed on the ceramic green substrates. The dynamic thermo-mechanical analysis indicated that extending the holding time at certain temperature range would harden the green substrates with little effect on improving the embossing fidelity. Ceramic substrates with embossed micro patterns were obtain d after co-firi...

  11. Sparse Reconstruction for Micro Defect Detection in Acoustic Micro Imaging

    Directory of Open Access Journals (Sweden)

    Yichun Zhang

    2016-10-01

    Full Text Available Acoustic micro imaging has been proven to be sufficiently sensitive for micro defect detection. In this study, we propose a sparse reconstruction method for acoustic micro imaging. A finite element model with a micro defect is developed to emulate the physical scanning. Then we obtain the point spread function, a blur kernel for sparse reconstruction. We reconstruct deblurred images from the oversampled C-scan images based on l1-norm regularization, which can enhance the signal-to-noise ratio and improve the accuracy of micro defect detection. The method is further verified by experimental data. The results demonstrate that the sparse reconstruction is effective for micro defect detection in acoustic micro imaging.

  12. Micro Information Systems

    DEFF Research Database (Denmark)

    Ulslev Pedersen, Rasmus; Kühn Pedersen, Mogens

    2014-01-01

    such as medical and manufacturing. These new sensor applications have implications for information systems (IS) and, the authors visualize this new class of information systems as fractals growing from an established class of systems; namely that of information systems (IS). The identified applications...... and implications are used as an empirical basis for creating a model for these small new information systems. Such sensor systems are called embedded systems in the technical sciences, and the authors want to couple it with general IS. They call the merger of these two important research areas (IS and embedded...... systems) for micro information systems (micro-IS). It is intended as a new research field within IS research. An initial framework model is established, which seeks to capture both the possibilities and constraints of this new paradigm, while looking simultaneously at the fundamental IS and ICT aspects...

  13. CERN MicroClub

    CERN Multimedia

    CERN MicroClub

    2016-01-01

    Le CERN Micro Club (en partenariat avec Google Education et EU Code Week) organise un évènement éducatif exceptionnel autour de trois kits scientifiques basés sur le mini-ordinateur Raspberry Pi : Le Bras Robotique "Poppy Ergo Jr", conçu par l'équipe-projet Flowers (Centre de recherche Inria Bordeaux Sud-Ouest, ENSTA Paris Tech). Le kit de détection de rayons cosmiques "Muon Hunter", conçu en partenariat entre Mr Mihaly Vadai et les membres du CERN Micro Club. La voiture radio-commandée programmable Wifi "GianoPi", conçue en partenariat avec le campus "La Chataigneraie", pour l'Ecole Internationale de Genève.   Le vendredi 7 octobre (de 18h à 20h) : Une conférence gratuite et ouverte à tous (limitée à 100 personnes), pendant laquelle v...

  14. Micro pulse laser radar

    Science.gov (United States)

    Spinhirne, James D. (Inventor)

    1993-01-01

    An eye safe, compact, solid state lidar for profiling atmospheric cloud and aerosol scattering is disclosed. The transmitter of the micro pulse lidar is a diode pumped micro-J pulse energy, high repetition rate Nd:YLF laser. Eye safety is obtained through beam expansion. The receiver employs a photon counting solid state Geiger mode avalanche photodiode detector. Data acquisition is by a single card multichannel scaler. Daytime background induced quantum noise is controlled by a narrow receiver field-of-view and a narrow bandwidth temperature controlled interference filter. Dynamic range of the signal is limited to optical geometric signal compression. Signal simulations and initial atmospheric measurements indicate that micropulse lider systems are capable of detecting and profiling all significant cloud and aerosol scattering through the troposphere and into the stratosphere. The intended applications are scientific studies and environmental monitoring which require full time, unattended measurements of the cloud and aerosol height structure.

  15. Understanding Micro Plasmas

    CERN Document Server

    Winter, J; Böke, M; Ellerweg, D; Hemke, T; Knake, N; Mussenbrock, T; Niermann, B; Schröder, D; der Gathen, V Schulz-von; von Keudell, A

    2011-01-01

    Micro plasmas are operated around atmospheric pressure exhibiting pronounced non-equilibrium characteristics, i.e. they possess energetic electrons while ions and neutrals remain cold. They have gained significant interest due to their enormous application potential e.g. in the biomedical, surface modification and light source areas, just to name a few. Many different configurations are in use. Their understanding and quantification is mandatory for further progress in applications. We report on recent progress in the diagnostics and simulation of the entire micro plasma system from gas introduction, via the plasma discharge up to the samples at the example of a plasma jet operated in He/O2 in an ambient air environment.

  16. Scanning micro-sclerometer

    Science.gov (United States)

    Oliver, Warren C.; Blau, Peter J.

    1994-01-01

    A scanning micro-sclerometer measures changes in contact stiffness and correlates these changes to characteristics of a scratch. A known force is applied to a contact junction between two bodies and a technique employing an oscillating force is used to generate the contact stiffness between the two bodies. As the two bodies slide relative to each other, the contact stiffness changes. The change is measured to characterize the scratch.

  17. MicroRNA pharmacogenomics

    DEFF Research Database (Denmark)

    Rukov, Jakob Lewin; Shomron, Noam

    2011-01-01

    polymorphisms, copy number variations or differences in gene expression levels of drug metabolizing or transporting genes and drug targets. In this review paper, we focus instead on microRNAs (miRNAs): small noncoding RNAs, prevalent in metazoans, that negatively regulate gene expression in many cellular...... processes. We discuss how miRNAs, by regulating the expression of pharmacogenomic-related genes, can play a pivotal role in drug efficacy and toxicity and have potential clinical implications for personalized medicine....

  18. Wear of micro end mills

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Hansen, Hans Nørgaard; De Chiffre, Leonardo

    2005-01-01

    This paper addresses the important issue of wear on micro end mills considering relevant metrological tools for its characterization and quantification. Investigation of wear on micro end mills is particularly difficult and no data are available in the literature. Small worn volumes cause large...... deviations from the ideal micro tool shape, dramatically changing the cutting edge profile as well as rake and clearance angles. This critically affects the performance of the micro tool leading to increased cutting forces and micro tool deflections with detrimental effects on the accuracy of the machined...... part. For this investigation 200 microns end mills are considered. Visual inspection of the micro tools requires high magnification and depth of focus. 3D reconstruction based on scanning electron microscope (SEM) images and stereo-pair technique is foreseen as a possible method for quantification...

  19. micro strip gas chamber

    CERN Multimedia

    1998-01-01

    About 16 000 Micro Strip Gas Chambers like this one will be used in the CMS tracking detector. They will measure the tracks of charged particles to a hundredth of a millimetre precision in the region near the collision point where the density of particles is very high. Each chamber is filled with a gas mixture of argon and dimethyl ether. Charged particles passing through ionise the gas, knocking out electrons which are collected on the aluminium strips visible under the microscope. Such detectors are being used in radiography. They give higher resolution imaging and reduce the required dose of radiation.

  20. MicroCMOS design

    CERN Document Server

    Song, Bang-Sup

    2011-01-01

    MicroCMOS Design covers key analog design methodologies with an emphasis on analog systems that can be integrated into systems-on-chip (SoCs). Starting at the transistor level, this book introduces basic concepts in the design of system-level complementary metal-oxide semiconductors (CMOS). It uses practical examples to illustrate circuit construction so that readers can develop an intuitive understanding rather than just assimilate the usual conventional analytical knowledge. As SoCs become increasingly complex, analog/radio frequency (RF) system designers have to master both system- and tran

  1. Silica Micro Encapsulation

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, P.; Whitbread-Jordan, M. [KEECO (United Kingdom)

    2001-04-01

    The article explains how Silica Micro Encapsulation (SME) water treatment technology may be transferred from metal mining to coal mining operations. KEECO has been developing a unique solution for treating acid rock drainage in the metal sulphide mining sector and following trials in metal mining operations (described in the article), is preparing to transfer the technology to the coal industry. SME technology comprises metal precipitation and encapsulation accomplished with proprietary chemical, KB-1, and a group of patented chemical dosing systems, the K-series, to dose KB-1 into contaminated liquid wastes as a dry powder. 4 figs., 4 tabs.

  2. Micro manufacturing techniques and applications

    CERN Document Server

    Du, Ruxu; Li, Zifu

    2013-01-01

    Micro/meso-scale manufacturing has been developed in research fields of machining, forming, materials and others, but its potential to industries are yet to be fully realized. The theme of the current volume was to build a bridge joining academic research and industrial needs in micro manufacturing. Among the 12 papers selected for publication are three keynote addresses onmicro and desktop factories for micro/meso-scale manufacturing applicationsand future visions, tissue cutting mechanics and applications for needlecore biopsy and guidance, and micro-texturing onto amorphous carbonmaterials

  3. Micro-pattern gaseous detectors

    CERN Document Server

    Shekhtman, L I

    2002-01-01

    Introduced at the end of 1980s micro-pattern gas detectors perform much better than classic wire chambers. They allow to achieve both excellent localization accuracy and high rate capability that make this technology attractive for charged particle tracking at high luminosity colliders. During its evolution micro-pattern gas technology gave raise to many different types of devices such as micro-strip gas chambers, MicroMEGAS, CAT and gas electron multipliers. Essential improvements in the performance of the detectors were achieved especially in what concerned long-term performance: aging and resistance to accidental discharges.

  4. Nozzle fabrication for Micro Propulsion of a Micro-Satellite

    NARCIS (Netherlands)

    Louwerse, M.C.; Jansen, Henricus V.; Groenendijk, M.N.W.; Elwenspoek, Michael Curt

    2008-01-01

    To enable formation flying of micro satellites, small sized propulsion systems are required. Our research focuses on the miniaturization of a feeding and thruster system by means of micro system technology (MST). Three fabrication methods have been investigated to make a conical converging-diverging

  5. A micro-coupling for micro mechanical systems

    Science.gov (United States)

    Li, Wei; Zhou, Zhixiong; Zhang, Bi; Xiao, Yunya

    2016-05-01

    The error motions of micro mechanical systems, such as micro-spindles, increase with the increasing of the rotational speed, which not only decreases the rotational accuracy, but also promotes instability and limits the maximum operational speed. One effective way to deal with it is to use micro-flexible couplings between the drive and driven shafts so as to reduce error motions of the driven shaft. But the conventional couplings, such as diaphragm couplings, elastomeric couplings, bellows couplings, and grooved couplings, etc, cannot be directly used because of their large and complicated structures. This study presents a novel micro-coupling that consists of a flexible coupling and a shape memory alloy (SMA)-based clamp for micro mechanical systems. It is monolithic and can be directly machined from a shaft. The study performs design optimization and provides manufacturing considerations, including thermo-mechanical training of the SMA ring for the desired Two-Way-Shape-Memory effect (TWSMe). A prototype micro-coupling and a prototype micro-spindle using the proposed coupling are fabricated and tested. The testing results show that the prototype micro-coupling can bear a torque of above 5 N • mm and an axial force of 8.5 N and be fitted with an SMA ring for clamping action at room temperature (15 °C) and unclamping action below-5 °C. At the same time, the prototype micro-coupling can work at a rotational speed of above 200 kr/min with the application to a high-speed precision micro-spindle. Moreover, the radial runout error of the artifact, as a substitute for the micro-tool, is less than 3 μm while that of turbine shaft is above 7 μm. It can be concluded that the micro-coupling successfully accommodates misalignment errors of the prototype micro-spindle. This research proposes a micro-coupling which is featured with an SMA ring, and it is designed to clamp two shafts, and has smooth transmission, simple assembly, compact structure, zero-maintenance and

  6. Micro rotary machine and methods for using same

    Science.gov (United States)

    Stalford, Harold L [Norman, OK

    2012-04-17

    A micro rotary machine may include a micro actuator and a micro shaft coupled to the micro actuator. The micro shaft comprises a horizontal shaft and is operable to be rotated by the micro actuator. A micro tool is coupled to the micro shaft and is operable to perform work in response to motion of the micro shaft.

  7. Micro Factory Systems and Tooling

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard

    2003-01-01

    The presentation deals with the micro factory concept in general and with the issues related to manufacturing, handling/assembly and quality control in particular.......The presentation deals with the micro factory concept in general and with the issues related to manufacturing, handling/assembly and quality control in particular....

  8. Micro Factory Systems and Tooling

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard

    2003-01-01

    The presentation deals with the micro factory concept in general and with the issues related to manufacturing, handling/assembly and quality control in particular.......The presentation deals with the micro factory concept in general and with the issues related to manufacturing, handling/assembly and quality control in particular....

  9. Micro-channel plate detector

    Science.gov (United States)

    Elam, Jeffrey W.; Lee, Seon W.; Wang, Hsien -Hau; Pellin, Michael J.; Byrum, Karen; Frisch, Henry J.

    2015-09-22

    A method and system for providing a micro-channel plate detector. An anodized aluminum oxide membrane is provided and includes a plurality of nanopores which have an Al coating and a thin layer of an emissive oxide material responsive to incident radiation, thereby providing a plurality of radiation sensitive channels for the micro-channel plate detector.

  10. Micro mixer with fast diffusion

    NARCIS (Netherlands)

    Miyake, Ryo; Miyake, R.; Lammerink, Theodorus S.J.; Elwenspoek, Michael Curt; Fluitman, J.H.J.

    1993-01-01

    A new concept for micro-mixing of liquid is introduced and feasibility is demonstrated. The mixer allows fast mixing of small amounts of two liquids and it is application to micro-liquid handling systems [1]. The mixer has a channel for the liquid, an inlet port for the reagent, and a 2.2 mm × 2 mm

  11. Wear of micro end mills

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Hansen, Hans Nørgaard; De Chiffre, Leonardo

    2005-01-01

    This paper addresses the important issue of wear on micro end mills considering relevant metrological tools for its characterization and quantification. Investigation of wear on micro end mills is particularly difficult and no data are available in the literature. Small worn volumes cause large d...

  12. Micro Environmental Concrete

    Science.gov (United States)

    Lanez, M.; Oudjit, M. N.; Zenati, A.; Arroudj, K.; Bali, A.

    Reactive powder concretes (RPC) are characterized by a particle diameter not exceeding 600 μm and having very high compressive and tensile strengths. This paper describes a new generation of micro concrete, which has an initial as well as a final high physicomechanical performance. To achieve this, 15% by weight of the Portland cement have been substituted by materials rich in Silica (Slag and Dune Sand). The results obtained from the tests carried out on the RPC show that compressive and tensile strengths increase when incorporating the addition, thus improving the compactness of mixtures through filler and pozzolanic effects. With a reduction in the aggregate phase in the RPC and the abundance of the dune sand (southern of Algeria) and slag (industrial by-product of the blast furnace), the use of the RPC will allow Algeria to fulfil economical as well as ecological requirements.

  13. MicroProteins

    DEFF Research Database (Denmark)

    Eguen, Teinai Ebimienere; Straub, Daniel; Graeff, Moritz;

    2015-01-01

    MicroProteins (miPs) are short, usually single-domain proteins that, in analogy to miRNAs, heterodimerize with their targets and exert a dominant-negative effect. Recent bioinformatic attempts to identify miPs have resulted in a list of potential miPs, many of which lack the defining...... characteristics of a miP. In this opinion article, we clearly state the characteristics of a miP as evidenced by known proteins that fit the definition; we explain why modulatory proteins misrepresented as miPs do not qualify as true miPs. We also discuss the evolutionary history of miPs, and how the miP concept...

  14. Micro pulse lidar

    Science.gov (United States)

    Spinhirne, James D.

    1993-01-01

    An eye safe, compact, solid state lidar for profiling atmospheric cloud and aerosol scattering has been demonstrated. The transmitter of the micropulse lidar is a diode pumped micro-J pulse energy, high repetition rate Nd:YLF laser. Eye safety is obtained through beam expansion. The receiver employs a photon counting solid state Geiger mode avalanche photodiode detector. Data acquisition is by a single card multichannel scaler. Daytime background induced quantum noise is controlled by a narrow receiver field-of-view and a narrow bandwidth temperature controlled interference filter. Dynamic range of the signal is limited by optical geometric signal compression. Signal simulations and initial atmospheric measurements indicate that systems built on the micropulse lidar concept are capable of detecting and profiling all significant cloud and aerosol scattering through the troposphere and into the stratosphere. The intended applications are scientific studies and environmental monitoring which require full time, unattended measurements of the cloud and aerosol height structure.

  15. [MicroRNAs in neurobiology].

    Science.gov (United States)

    Kawahara, Yukio

    2008-12-01

    MicroRNAs have emerged as a new regulatory factor of gene expression. They mediate translational repression or degradation of their target mRNAs by RNA interference (RNAi). The expression of each microRNA is tightly regulated in a development- and cell-specific manner by various mechanisms such as blockade of let-7 family expression by Lin-28 or RNA editing. They also act as regulatory switches for development, organogenesis, and cellular differentiation or for controlling distinct functions that are required for the maintenance of each tissue and cell subtypes. The abundant expression of microRNAs as well as the exclusive expression of certain microRNAs in the central nervous system highlights their biological importance at all stages of neural development and in postmitotic and differentiated neurons. Further, some microRNAs, such as miRNA-134, and miRNA-132 are localized and are synthesized in part at synaptic sites in dendrites to regulate synaptic formation and plasticity. In addition to the imparting of basic knowledge about the biogenesis and mechanism of action of microRNAs, this review focuses on the recent advances in microRNA studies in neurobiology, including the expression pattern of microRNAs in the mammalian brain, the role of microRNAs in neural differentiation and maturation, formation and plasticity of synaptic connections, and maintenance of neural function such as the synthesis of the neurotransmitters in selected neurons. Finally, the possible connection between microRNA dysfunction and neurological diseases, and future implications for diagnosis, and treatment of defects in human brain development and neurodegenerative diseases are discussed.

  16. Sustainable Micro-Manufacturing of Micro-Components via Micro Electrical Discharge Machining

    Directory of Open Access Journals (Sweden)

    Valeria Marrocco

    2011-12-01

    Full Text Available Micro-manufacturing emerged in the last years as a new engineering area with the potential of increasing peoples’ quality of life through the production of innovative micro-devices to be used, for example, in the biomedical, micro-electronics or telecommunication sectors. The possibility to decrease the energy consumption makes the micro-manufacturing extremely appealing in terms of environmental protection. However, despite this common belief that the micro-scale implies a higher sustainability compared to traditional manufacturing processes, recent research shows that some factors can make micro-manufacturing processes not as sustainable as expected. In particular, the use of rare raw materials and the need of higher purity of processes, to preserve product quality and manufacturing equipment, can be a source for additional environmental burden and process costs. Consequently, research is needed to optimize micro-manufacturing processes in order to guarantee the minimum consumption of raw materials, consumables and energy. In this paper, the experimental results obtained by the micro-electrical discharge machining (micro-EDM of micro-channels made on Ni–Cr–Mo steel is reported. The aim of such investigation is to shed a light on the relation and dependence between the material removal process, identified in the evaluation of material removal rate (MRR and tool wear ratio (TWR, and some of the most important technological parameters (i.e., open voltage, discharge current, pulse width and frequency, in order to experimentally quantify the material waste produced and optimize the technological process in order to decrease it.

  17. Automated Micro Hall Effect measurements

    DEFF Research Database (Denmark)

    Petersen, Dirch Hjorth; Henrichsen, Henrik Hartmann; Lin, Rong

    2014-01-01

    With increasing complexity of processes and variety of materials used for semiconductor devices, stringent control of the electronic properties is becoming ever more relevant. Collinear micro four-point probe (M4PP) based measurement systems have become high-end metrology methods for characteriza......With increasing complexity of processes and variety of materials used for semiconductor devices, stringent control of the electronic properties is becoming ever more relevant. Collinear micro four-point probe (M4PP) based measurement systems have become high-end metrology methods...... for characterization and monitoring of sheet resistance as well as sheet carrier density and mobility via the Micro Hall Effect (MHE) method....

  18. Micro Injection Moulding of Polymeric Components

    Science.gov (United States)

    Trotta, G.; Surace, R.; Modica, F.; Spina, R.; Fassi, I.

    2011-01-01

    Micro components and micro devices are strongly used in several fields: IT components, biomedical and medical products, automotive industry, telecommunication area and aerospace. A micro component is characterized by small dimensions of the product itself or small dimensions of the functional features. The development of new micro parts is highly dependent on manufacturing systems that can reliably and economically produce micro components in large quantities. In this context, micro-electrical discharge machining (EDM) for mould production and micro-injection moulding of polymer materials are the key technologies for micro manufacturing. This paper will focus on the production and quality evaluation of polymeric micro components manufactured by micro injection moulding. In particular the authors want to investigate the process parameters on the overall quality of the product. The factors affecting micro flow behavior, components weights and dimension definition are experimentally studied basing on DoE approach and then discussed.

  19. Micro-mixer/combustor

    KAUST Repository

    Badra, Jihad Ahmad

    2014-09-18

    A micro-mixer/combustor to mix fuel and oxidant streams into combustible mixtures where flames resulting from combustion of the mixture can be sustained inside its combustion chamber is provided. The present design is particularly suitable for diffusion flames. In various aspects the present design mixes the fuel and oxidant streams prior to entering a combustion chamber. The combustion chamber is designed to prevent excess pressure to build up within the combustion chamber, which build up can cause instabilities in the flame. A restriction in the inlet to the combustion chamber from the mixing chamber forces the incoming streams to converge while introducing minor pressure drop. In one or more aspects, heat from combustion products exhausted from the combustion chamber may be used to provide heat to at least one of fuel passing through the fuel inlet channel, oxidant passing through the oxidant inlet channel, the mixing chamber, or the combustion chamber. In one or more aspects, an ignition strip may be positioned in the combustion chamber to sustain a flame without preheating.

  20. Levitated micro-accelerometer.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin; Schmidt, Carrie Frances; Peterson, Kenneth Allen; Kravitz, Stanley H.; Renn, Rosemarie A.; Peter, Frank J.; Kinney, Ragon D.; Gilkey, Jeffrey C.

    2004-06-01

    The objective is a significant advancement in the state-of-the-art of accelerometer design for tactical grade (or better) applications. The design goals are <1 milli-G bias stability across environments and $200 cost. This quantum leap in performance improvement and cost reduction can only be achieved by a radical new approach, not incremental improvements to existing concepts. This novel levitated closed-loop accelerometer is implemented as a hybrid micromachine. The hybrid approach frees the designer from the limitations of any given monolithic process and dramatically expands the available design space. The design can be tailored to the dynamic range, resolution, bandwidth, and environmental requirements of the application while still preserving all of the benefits of monolithic MEMS fabrication - extreme precision, small size, low cost, and low power. An accelerometer was designed and prototype hardware was built, driving the successful development and refinement of several 'never been done before' fabrication processes. Many of these process developments are commercially valuable and are key enablers for the realization of a wide variety of useful micro-devices. While controlled levitation of a proof mass has yet to be realized, the overall design concept remains sound. This was clearly demonstrated by the stable and reliable closed-loop control of a proof mass at the test structure level. Furthermore, the hybrid MEMS implementation is the most promising approach for achieving the ambitious cost and performance targets. It is strongly recommended that Sandia remain committed to the original goal.

  1. MicroRNA and cancer

    National Research Council Canada - National Science Library

    Jansson, Martin D; Lund, Anders H

    2012-01-01

    .... The best characterized non‐coding RNA family consists in humans of about 1400 microRNAs for which abundant evidence have demonstrated fundamental importance in normal development, differentiation, growth control and in human...

  2. Nitrous Oxide Micro Engines Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Nitrous Oxide Micro Engines (NOME) are a new type of nitrous oxide dissociation thruster designed to generate low levels of thrust that can be used for RCS control...

  3. Micro-gen metering solutions

    Energy Technology Data Exchange (ETDEWEB)

    Elland, J.; Dickson, J.; Cranfield, P.

    2003-07-01

    This report summarises the results of a project to investigate the regulation of domestic electricity metering work and identify the most economic options for micro-generator installers to undertake work on electricity meters. A micro-generation unit is defined as an energy conversion system converting non-electrical energy into electrical energy and can include technologies such as photovoltaic systems, small-scale wind turbines, micro-hydroelectric systems, and combined heat and power systems. Details of six tasks are given and cover examination of the existing framework and legal documentation for metering work, the existing technical requirements for meter operators, meter operator personnel accreditation, appraisal of options for meter changes and for micro-generation installation, document change procedures, industry consultation, and a review of the costs implications of the options.

  4. Highly Efficient Micro Cathode Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek Company, Inc. proposes to develop a micro thermionic cathode that requires extremely low power and provides long lifetime. The basis for the cathode is a...

  5. Fiber Sensing of Micro -Crack

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Optical fiber sensors are used for sensing micro-cracking in composite and metal materials in aerospace applications. The sensing mechanism is based on the detection of acoustic emission signals, which are known to emanate from micro-cracks when they grow under further loading. The sensor head consists of a fiber Bragg grating that is capable of detecting acoustic emission signals generated by pencil lead breaking, of frequencies up to 200 kHz.

  6. Low-drift micro flow sensors

    NARCIS (Netherlands)

    Dijkstra, Marcel

    2009-01-01

    The emerging fields of micro total-analysis systems (micro-TAS), micro-reactors and bio-MEMS drives the need for further miniaturisation of sensors measuring quantities such as pressure, temperature and flow. The research described in this thesis concerns the development of low-drift micro flow sens

  7. SMART micro-scissors based precise incision

    Science.gov (United States)

    Park, Hyun-Cheol; Yeo, Chaebeom; Song, Cheol

    2015-03-01

    Hand tremor reduction is important to achieve stable micro manipulation of the tool tip. A micro-scissors can be used for cutting delicate tissues safely. Here, we implement an OCT distance sensor guided SMART micro-scissors which could incise micro-surgical targets precisely and horizontally. Compared to freehand incision, it demonstrates enhanced incision performance on dry phantoms with great tremor suppression.

  8. Analysis of micro-forces between micro-parts and their influence factors in MEMS

    Institute of Scientific and Technical Information of China (English)

    LI Gui-xian; PENG Yun-feng; ZHANG Xin

    2008-01-01

    The research of micro-forces between micro-parts forms the base for micro-machine (MEMS) devel-opment. According to the characteristics of the interactions between micro-parts in MEMS, three models were simplified. Based on these models, micro-forces between micro-parts were analyzed, and the analytical formulas were formulated. Factors which may affect the micro-forces, such as surface condition, media and constitutive material of micro-parts were discussed. A coefficient of surface roughness on micro-forces was introduced,which facilitated the analysis of the influence of surface roughness.

  9. Micro-droplet formation via 3D printed micro channel

    Science.gov (United States)

    Jian, Zhen; Zhang, Jiaming; Li, Erqiang; Thoroddsen, Sigurdur T.

    2016-11-01

    Low cost, fast-designed and fast-fabricated 3D micro channel was used to create micro-droplets. Capillary with an outer diameter of 1.5 mm and an inner diameter of 150 μm was inserted into a 3D printed cylindrical channel with a diameter of 2 mm . Flow rate of the two inlets, insert depth, liquid (density, viscosity and surface tension) and solid (roughness, contact angle) properties all play a role in the droplet formation. Different regimes - dripping, jetting, unstable state - were observed in the micro-channel on varying these parameters. With certain parameter combinations, successive formation of micro-droplets with equal size was observed and its size can be much smaller than the smallest channel size. Based on our experimental results, the droplet formation via 3D printed micro T-junction was investigated through direct numerical simulations with a code called Gerris. Reynolds numbers Re = ρUL / μ and Weber numbers We = ρU2 L / σ of the two liquids were introduced to measure the liquid effect. The parameter regime where different physical dynamics occur was studied and the regime transition was observed with certain threshold values. Qualitative and quantitative analysis were performed as well between simulations and experiments.

  10. Micro-range micro-doppler for dismount classification

    Science.gov (United States)

    Tahmoush, Dave

    2013-05-01

    This paper presents a processing technique that can be used to detect and classify pedestrians group based on the micro- Doppler signature gathered with a millimeter wave radar. The evaluation of the number of pedestrians moving in a group can be a difficult task using a traditional micro-Doppler spectrogram because of a tendency for people to partially synchronize their steps when walking together. The new approach, based on multi-range variation as well as the micro-Doppler variations, provides promising results. The range-spectrogram processing technique was developed and tested using a database composed of hundreds of pedestrian and vehicle signatures gathered in an urban test site over a two year period in a variety of weather conditions. We associate image detections with radar detections through motion extracted from both radar and imagery. We also explain how radar and video together can produce an inexpensive alternative to 3-D imaging.

  11. Tunable Micro- and Nanomechanical Resonators

    Science.gov (United States)

    Zhang, Wen-Ming; Hu, Kai-Ming; Peng, Zhi-Ke; Meng, Guang

    2015-01-01

    Advances in micro- and nanofabrication technologies have enabled the development of novel micro- and nanomechanical resonators which have attracted significant attention due to their fascinating physical properties and growing potential applications. In this review, we have presented a brief overview of the resonance behavior and frequency tuning principles by varying either the mass or the stiffness of resonators. The progress in micro- and nanomechanical resonators using the tuning electrode, tuning fork, and suspended channel structures and made of graphene have been reviewed. We have also highlighted some major influencing factors such as large-amplitude effect, surface effect and fluid effect on the performances of resonators. More specifically, we have addressed the effects of axial stress/strain, residual surface stress and adsorption-induced surface stress on the sensing and detection applications and discussed the current challenges. We have significantly focused on the active and passive frequency tuning methods and techniques for micro- and nanomechanical resonator applications. On one hand, we have comprehensively evaluated the advantages and disadvantages of each strategy, including active methods such as electrothermal, electrostatic, piezoelectrical, dielectric, magnetomotive, photothermal, mode-coupling as well as tension-based tuning mechanisms, and passive techniques such as post-fabrication and post-packaging tuning processes. On the other hand, the tuning capability and challenges to integrate reliable and customizable frequency tuning methods have been addressed. We have additionally concluded with a discussion of important future directions for further tunable micro- and nanomechanical resonators. PMID:26501294

  12. Micro Machining Enhances Precision Fabrication

    Science.gov (United States)

    2007-01-01

    Advanced thermal systems developed for the Space Station Freedom project are now in use on the International Space Station. These thermal systems employ evaporative ammonia as their coolant, and though they employ the same series of chemical reactions as terrestrial refrigerators, the space-bound coolers are significantly smaller. Two Small Business Innovation Research (SBIR) contracts between Creare Inc. of Hanover, NH and Johnson Space Center developed an ammonia evaporator for thermal management systems aboard Freedom. The principal investigator for Creare Inc., formed Mikros Technologies Inc. to commercialize the work. Mikros Technologies then developed an advanced form of micro-electrical discharge machining (micro-EDM) to make tiny holes in the ammonia evaporator. Mikros Technologies has had great success applying this method to the fabrication of micro-nozzle array systems for industrial ink jet printing systems. The company is currently the world leader in fabrication of stainless steel micro-nozzles for this market, and in 2001 the company was awarded two SBIR research contracts from Goddard Space Flight Center to advance micro-fabrication and high-performance thermal management technologies.

  13. Tunable Micro- and Nanomechanical Resonators

    Directory of Open Access Journals (Sweden)

    Wen-Ming Zhang

    2015-10-01

    Full Text Available Advances in micro- and nanofabrication technologies have enabled the development of novel micro- and nanomechanical resonators which have attracted significant attention due to their fascinating physical properties and growing potential applications. In this review, we have presented a brief overview of the resonance behavior and frequency tuning principles by varying either the mass or the stiffness of resonators. The progress in micro- and nanomechanical resonators using the tuning electrode, tuning fork, and suspended channel structures and made of graphene have been reviewed. We have also highlighted some major influencing factors such as large-amplitude effect, surface effect and fluid effect on the performances of resonators. More specifically, we have addressed the effects of axial stress/strain, residual surface stress and adsorption-induced surface stress on the sensing and detection applications and discussed the current challenges. We have significantly focused on the active and passive frequency tuning methods and techniques for micro- and nanomechanical resonator applications. On one hand, we have comprehensively evaluated the advantages and disadvantages of each strategy, including active methods such as electrothermal, electrostatic, piezoelectrical, dielectric, magnetomotive, photothermal, mode-coupling as well as tension-based tuning mechanisms, and passive techniques such as post-fabrication and post-packaging tuning processes. On the other hand, the tuning capability and challenges to integrate reliable and customizable frequency tuning methods have been addressed. We have additionally concluded with a discussion of important future directions for further tunable micro- and nanomechanical resonators.

  14. [MicroRNAs and kidneys].

    Science.gov (United States)

    Stříteská, Jana; Nekvindová, Jana; Cerný, Vladimír; Palička, Vladimír

    2014-01-01

    MicroRNAs are short non-coding ribonucleic acid molecules that regulate gene expression at the post-transcriptional level thus affecting important physiological as well as pathophysiological processes in the organism, for example cell differentiation, proliferation, apoptosis, and metabolism. They are involved in pathogenesis of many diseases including cancer. Many microRNAs are tissue or organ-specific which implies their possible potential as biomarkers or maybe even therapeutical agents as documented by microRNA research interest rising exponentially during last years. Among all, microRNAs are important also for physiological function of the kidney and they are involved in various renal disorders. Today research is focused mainly on renal and urinary tract carcinogenesis, acute kidney injury, chronic renal diseases (polycystic kidney disease) or renal complications of systemic diseases such as diabetic or hypertension nephropathy and autoimmune kidney injury including acute allograft rejection after kidney transplantation. The review summarizes current information about microRNA effect on kidney development and function and also on the most common kidney diseases.

  15. Equivalent Simplification Method of Micro-Grid

    Directory of Open Access Journals (Sweden)

    Cai Changchun

    2013-09-01

    Full Text Available The paper concentrates on the equivalent simplification method for the micro-grid system connection into distributed network. The equivalent simplification method proposed for interaction study between micro-grid and distributed network. Micro-grid network, composite load, gas turbine synchronous generation, wind generation are equivalent simplification and parallel connect into the point of common coupling. A micro-grid system is built and three phase and single phase grounded faults are performed for the test of the equivalent model of micro-grid. The simulation results show that the equivalent model of micro-grid is effective, and the dynamic of equivalent model is similar with the detailed model of micro-grid. The equivalent simplification method for the micro-grid network and distributed components is suitable for the study of micro-grid.  

  16. Micro-Mechanical Temperature Sensors

    DEFF Research Database (Denmark)

    Larsen, Tom

    Temperature is the most frequently measured physical quantity in the world. The field of thermometry is therefore constantly evolving towards better temperature sensors and better temperature measurements. The aim of this Ph.D. project was to improve an existing type of micro-mechanical temperature...... sensor or to develop a new one. Two types of micro-mechanical temperature sensors have been studied: Bilayer cantilevers and string-like beam resonators. Both sensor types utilize thermally generated stress. Bilayer cantilevers are frequently used as temperature sensors at the micro-scale, and the goal....... The reduced sensitivity was due to initial bending of the cantilevers and poor adhesion between the two cantilever materials. No further attempts were made to improve the sensitivity of bilayer cantilevers. The concept of using string-like resonators as temperature sensors has, for the first time, been...

  17. Zeolite-dye micro lasers

    CERN Document Server

    Vietze, U; Laeri, F; Ihlein, G; Schüth, F; Limburg, B; Abraham, M

    1998-01-01

    We present a new class of micro lasers based on nanoporous molecular sieve host-guest systems. Organic dye guest molecules of 1-Ethyl-4-(4-(p-Dimethylaminophenyl)-1,3-butadienyl)-pyridinium Perchlorat were inserted into the 0.73-nm-wide channel pores of a zeolite AlPO$_4$-5 host. The zeolitic micro crystal compounds where hydrothermally synthesized according to a particular host-guest chemical process. The dye molecules are found not only to be aligned along the host channel axis, but to be oriented as well. Single mode laser emission at 687 nm was obtained from a whispering gallery mode oscillating in a 8-$\\mu$m-diameter monolithic micro resonator, in which the field is confined by total internal reflection at the natural hexagonal boundaries inside the zeolitic microcrystals.

  18. Dimensional micro and nano metrology

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; da Costa Carneiro, Kim; Haitjema, Han

    2006-01-01

    The need for dimensional micro and nano metrology is evident, and as critical dimensions are scaled down and geometrical complexity of objects is increased, the available technologies appear not sufficient. Major research and development efforts have to be undertaken in order to answer these chal......The need for dimensional micro and nano metrology is evident, and as critical dimensions are scaled down and geometrical complexity of objects is increased, the available technologies appear not sufficient. Major research and development efforts have to be undertaken in order to answer...... these challenges. The developments have to include new measuring principles and instrumentation, tolerancing rules and procedures as well as traceability and calibration. The current paper describes issues and challenges in dimensional micro and nano metrology by reviewing typical measurement tasks and available...

  19. MicroRNA and cancer

    DEFF Research Database (Denmark)

    Jansson, Martin D; Lund, Anders H

    2012-01-01

    biological phenomena and pathologies. The best characterized non-coding RNA family consists in humans of about 1400 microRNAs for which abundant evidence have demonstrated fundamental importance in normal development, differentiation, growth control and in human diseases such as cancer. In this review, we...... summarize the current knowledge and concepts concerning the involvement of microRNAs in cancer, which have emerged from the study of cell culture and animal model systems, including the regulation of key cancer-related pathways, such as cell cycle control and the DNA damage response. Importantly, microRNA......With the advent of next generation sequencing techniques a previously unknown world of non-coding RNA molecules have been discovered. Non-coding RNA transcripts likely outnumber the group of protein coding sequences and hold promise of many new discoveries and mechanistic explanations for essential...

  20. Development of Micro UAV Swarms

    Science.gov (United States)

    Bürkle, Axel; Leuchter, Sandro

    Some complex application scenarios for micro UAVs (Unmanned Aerial Vehicles) call for the formation of swarms of multiple drones. In this paper a platform for the creation of such swarms is presented. It consists of modified commercial quadrocopters and a self-made ground control station software architecture. Autonomy of individual drones is generated through a micro controller equipped video camera. Currently it is possible to fly basic maneuvers autonomously, such as take-off, fly to position, and landing. In the future the camera's image processing capabilities will be used to generate additional control information. Different co-operation strategies for teams of UAVs are currently evaluated with an agent based simulation tool. Finally complex application scenarios for multiple micro UAVs are presented.

  1. Novel Micro Fourier Transform Spectrometers

    Institute of Scientific and Technical Information of China (English)

    KONG Yan-mei; LIANG Jing-qiu; LIANG Zhong-zhu; WANG-Bo; ZHANG Jun

    2008-01-01

    The miniaturization of spectrometer opens a new application area with real-time and on-site measurements. The Fourier transform spectrometer(FTS) is much attractive considering its particular advantages among the approaches. This paper reviews the current status of micro FTS in worldwide and describes its developments; In addition, analyzed are the key problems in designing and fabricating FTS to be settled during the miniaturization. Finally, a novel model of micro FTS with no moving parts is proposed and analyzed, which may provide new concepts for the design of spectrometers.

  2. Phenotypic MicroRNA Microarrays

    OpenAIRE

    2013-01-01

    Microarray technology has become a very popular approach in cases where multiple experiments need to be conducted repeatedly or done with a variety of samples. In our lab, we are applying our high density spots microarray approach to microscopy visualization of the effects of transiently introduced siRNA or cDNA on cellular morphology or phenotype. In this publication, we are discussing the possibility of using this micro-scale high throughput process to study the role of microRNAs in the bio...

  3. Micro-machined calorimetric biosensors

    Science.gov (United States)

    Doktycz, Mitchel J.; Britton, Jr., Charles L.; Smith, Stephen F.; Oden, Patrick I.; Bryan, William L.; Moore, James A.; Thundat, Thomas G.; Warmack, Robert J.

    2002-01-01

    A method and apparatus are provided for detecting and monitoring micro-volumetric enthalpic changes caused by molecular reactions. Micro-machining techniques are used to create very small thermally isolated masses incorporating temperature-sensitive circuitry. The thermally isolated masses are provided with a molecular layer or coating, and the temperature-sensitive circuitry provides an indication when the molecules of the coating are involved in an enthalpic reaction. The thermally isolated masses may be provided singly or in arrays and, in the latter case, the molecular coatings may differ to provide qualitative and/or quantitative assays of a substance.

  4. Overview of MicroRNA Biology

    OpenAIRE

    2015-01-01

    In considering an overview of microRNA biology, it is useful to consider microRNAs as a part of cellular communication. At the simplest level, microRNAs act to decrease the expression of mRNAs that contain stretches of sequence complementary to the microRNA. This function can be likened to the function of endogenous or synthetic short interfering RNA (siRNA). However, microRNA function is more complicated and nuanced than this ‘on-off’ model would suggest. Further, many microRNA targets are t...

  5. Improvement of micro endmill geometry for micro hard milling application

    NARCIS (Netherlands)

    Li, P.; Oosterling, J.A.J.; Hoogstrate, A.M.; Langen, H.H.

    2008-01-01

    One of the applications of the micromilling technology is to machine micro features on moulds by direct machining of hardened tool steels. However at this moment, this process is not industrial applicable because of the encountered problems, such as the big tool deflection, severe tool wear, and

  6. Micro Gas Turbines (Micro turbines a gaz) (CD-ROM)

    Science.gov (United States)

    gasturbines , such as large heat fluxes, oil free bearings, high performance and compact heat exchangers, special combustion chamber designs and the use of...micro- gasturbines for propulsion of UAV and integration in fuel-cells are also presented. It is concluded that a lot of research is still required

  7. Improvement of micro endmill geometry for micro hard milling application

    NARCIS (Netherlands)

    Li, P.; Oosterling, J.A.J.; Hoogstrate, A.M.; Langen, H.H.

    2008-01-01

    One of the applications of the micromilling technology is to machine micro features on moulds by direct machining of hardened tool steels. However at this moment, this process is not industrial applicable because of the encountered problems, such as the big tool deflection, severe tool wear, and pre

  8. The collection of MicroED data for macromolecular crystallography.

    Science.gov (United States)

    Shi, Dan; Nannenga, Brent L; de la Cruz, M Jason; Liu, Jinyang; Sawtelle, Steven; Calero, Guillermo; Reyes, Francis E; Hattne, Johan; Gonen, Tamir

    2016-05-01

    The formation of large, well-ordered crystals for crystallographic experiments remains a crucial bottleneck to the structural understanding of many important biological systems. To help alleviate this problem in crystallography, we have developed the MicroED method for the collection of electron diffraction data from 3D microcrystals and nanocrystals of radiation-sensitive biological material. In this approach, liquid solutions containing protein microcrystals are deposited on carbon-coated electron microscopy grids and are vitrified by plunging them into liquid ethane. MicroED data are collected for each selected crystal using cryo-electron microscopy, in which the crystal is diffracted using very few electrons as the stage is continuously rotated. This protocol gives advice on how to identify microcrystals by light microscopy or by negative-stain electron microscopy in samples obtained from standard protein crystallization experiments. The protocol also includes information about custom-designed equipment for controlling crystal rotation and software for recording experimental parameters in diffraction image metadata. Identifying microcrystals, preparing samples and setting up the microscope for diffraction data collection take approximately half an hour for each step. Screening microcrystals for quality diffraction takes roughly an hour, and the collection of a single data set is ∼10 min in duration. Complete data sets and resulting high-resolution structures can be obtained from a single crystal or by merging data from multiple crystals.

  9. Micro RNAs in animal development.

    NARCIS (Netherlands)

    Plasterk, R.H.A.

    2006-01-01

    Micro RNAs (miRNAs) are approximately 22 nucleotide single-stranded noncoding RNA molecules that bind to target messenger RNAs (mRNAs) and silence their expression. This Essay explores the importance of miRNAs in animal development and their possible roles in disease and evolution.

  10. Micro-Based Genlocking Systems.

    Science.gov (United States)

    Hurly, Paul

    1986-01-01

    Presents a selective survey of micro-based genlocking systems currently on the market including those systems with open and closed architecture; examines the number and diversity of uses for this hybrid medium, which synchronizes video signals with computer-generated text and graphics; and discusses the role of cause and effect in innovation.

  11. Micro-machined resonator oscillator

    Science.gov (United States)

    Koehler, Dale R.; Sniegowski, Jeffry J.; Bivens, Hugh M.; Wessendorf, Kurt O.

    1994-01-01

    A micro-miniature resonator-oscillator is disclosed. Due to the miniaturization of the resonator-oscillator, oscillation frequencies of one MHz and higher are utilized. A thickness-mode quartz resonator housed in a micro-machined silicon package and operated as a "telemetered sensor beacon" that is, a digital, self-powered, remote, parameter measuring-transmitter in the FM-band. The resonator design uses trapped energy principles and temperature dependence methodology through crystal orientation control, with operation in the 20-100 MHz range. High volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Unique design features include squeeze-film damping for robust vibration and shock performance, capacitive coupling through micro-machined diaphragms allowing resonator excitation at the package exterior, circuit integration and extremely small (0.1 in. square) dimensioning. A family of micro-miniature sensor beacons is also disclosed with widespread applications as bio-medical sensors, vehicle status monitors and high-volume animal identification and health sensors. The sensor family allows measurement of temperatures, chemicals, acceleration and pressure. A microphone and clock realization is also available.

  12. Micro RNAs in animal development.

    NARCIS (Netherlands)

    Plasterk, R.H.A.

    2006-01-01

    Micro RNAs (miRNAs) are approximately 22 nucleotide single-stranded noncoding RNA molecules that bind to target messenger RNAs (mRNAs) and silence their expression. This Essay explores the importance of miRNAs in animal development and their possible roles in disease and evolution.

  13. Micro Evolutionary Processes and Adaptation

    Institute of Scientific and Technical Information of China (English)

    SHADMANOV; R; K; RUBAN; I; N; VOROPAEVA; N; L; SHADMANOVA; A; R

    2008-01-01

    It would be well to note that in the absence of clear data about the formation of adaptation systems,or mechanisms of their occurrence,all that is recognized is the realization of the micro evolutionary processes.There is no well-defined connection between information exchange and formation of

  14. Micro-Electro-Mechanical Systems

    NARCIS (Netherlands)

    Sarro, P.M.

    2008-01-01

    Micro-electro-mechanical systems (MEMS) or Microsystems technology (MST) is a fascinating and exciting field which significantly contributes to build a bridge between science and society. Physical properties and material characteristics are translated into structures and devices that can have a larg

  15. Micro-Electro-Mechanical Systems

    NARCIS (Netherlands)

    Sarro, P.M.

    2008-01-01

    Micro-electro-mechanical systems (MEMS) or Microsystems technology (MST) is a fascinating and exciting field which significantly contributes to build a bridge between science and society. Physical properties and material characteristics are translated into structures and devices that can have a

  16. Micro-Encapsulation of Probiotics

    Science.gov (United States)

    Meiners, Jean-Antoine

    Micro-encapsulation is defined as the technology for packaging with the help of protective membranes particles of finely ground solids, droplets of liquids or gaseous materials in small capsules that release their contents at controlled rates over prolonged periods of time under the influences of specific conditions (Boh, 2007). The material encapsulating the core is referred to as coating or shell.

  17. Equivalent Simplification Method of Micro-Grid

    OpenAIRE

    Cai Changchun; Cao Xiangqin

    2013-01-01

    The paper concentrates on the equivalent simplification method for the micro-grid system connection into distributed network. The equivalent simplification method proposed for interaction study between micro-grid and distributed network. Micro-grid network, composite load, gas turbine synchronous generation, wind generation are equivalent simplification and parallel connect into the point of common coupling. A micro-grid system is built and three phase and single phase grounded faults are per...

  18. Investigation of air entrapment and weld line defects in micro injection moulded thermoplastic elastomer micro rings

    DEFF Research Database (Denmark)

    Hasnaes, F.B.; Tosello, Guido; Calaon, Matteo;

    2015-01-01

    The micro injection moulding (μIM) process for the production of micro rings in thermoplastic elastomers (TPE) was investigated and optimized. The objective was to minimize the formation of air entrapments and the depth of micro weld line created on the surface of the TPE micro moulded rings...

  19. Micro tooling technologies for polymer micro replication: direct, indirect and hybrid process chains

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard

    2009-01-01

    and performance of the corresponding micro mould. Traditional methods of micro tooling, such as various machining processes (e.g. micro milling, micro electrical discharge machining) have already reached their limitations with decreasing dimensions of mould inserts and cavities. To this respect, tooling process...

  20. Spontaneous Calcium Changes in Micro Neuronal Networks

    Science.gov (United States)

    Saito, Aki; Moriguchi, Hiroyuki; Iwabuchi, Shin; Goto, Miho; Takayama, Yuzo; Kotani, Kiyoshi; Jimbo, Yasuhiko

    We have developed a practical experimental method to mass-produce and maintain a variation of minimal neuronal networks (“micro neuronal networks”) consisted of a single to several neurons in culture using spray-patterning technique. In this paper, we could maintain the micro-cultures for one month or more by adding conditioned medium and carried out optical recording of spontaneous activity in micro neuronal networks and considered the interactions between them. To determine the interactions between micro neuronal networks, fluorescence changes in several small networks were simultaneously measured using calcium indicator dye fluo-4 AM, and time-series analysis was carried out using surrogate arrangements. By using the spray-patterning method, a large number of cell-adhesive micro regions were formed. Neurons extended neurites along the edge of the cell-adhesive micro regions and form micro neuronal networks. In part of micro regions, some neurite was protruded from the region, and thus micro neuronal networks were connected with synapses. In these networks, a single neuron-induced network activity was observed. On the other hand, even in morphologically non-connected micro neuronal networks, synchronous oscillations between micro neuronal networks were observed. Our micro-patterning methods and results provide the possibility that synchronous activity is occurred between morphologically non-connected neuronal networks. This suggest that the humoral factor is also a important component for network-wide dynamics.

  1. A thermally self-sustained micro-power plant with integrated micro-solid oxide fuel cells, micro-reformer and functional micro-fluidic carrier

    NARCIS (Netherlands)

    Scherrer, B.; Evans, A.; Santis-Alvarez, A. J.; Jiang, B.; Martynczuk, J.; Galinski, H.; Nabavi, M.; Prestat, M.; Tölke, R.; Bieberle, A.; Poulikakos, D.; Muralt, P.; Niedermann, P.; Dommann, A.; Maeder, T.; Heeb, P.; Straessle, V.; Muller, C.; Gauckler, L. J.

    2014-01-01

    Low temperature micro-solid oxide fuel cell (micro-SOFC) systems are an attractive alternative power source for small-size portable electronic devices due to their high energy efficiency and density. Here, we report on a thermally self-sustainable reformer micro-SOFC assembly. The device consists of

  2. Development and design of micro products

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard

    2004-01-01

    Innovation within the field of micro and nano technology is characterized by cross-disciplinary skills The IT-sector driven development of materials/technologies related to semiconductors and silicon The more traditional materials polymers, metals, ceramics: well suited for mass production...... but not widespread in micro products today New possibilities with expensive materials in micro products....

  3. Micro-Doppler Analysis of Small UAVs

    NARCIS (Netherlands)

    Wit, J.J.M. de; Harmanny, R.I.A.; Prémel Cabic, G.

    2012-01-01

    Coherent radar measures micro-Doppler properties of moving objects. The micro-Doppler signature depends on parts of an object moving and rotating in addition to the main body motion (e.g. rotor blades) and is therefore characteristic for the type of object. In this study, the micro-Doppler signature

  4. Micro-Doppler Analysis of Small UAVs

    NARCIS (Netherlands)

    Wit, J.J.M. de; Harmanny, R.I.A.; Prémel Cabic, G.

    2012-01-01

    Coherent radar measures micro-Doppler properties of moving objects. The micro-Doppler signature depends on parts of an object moving and rotating in addition to the main body motion (e.g. rotor blades) and is therefore characteristic for the type of object. In this study, the micro-Doppler signature

  5. A thermally self-sustained micro-power plant with integrated micro-solid oxide fuel cells, micro-reformer and functional micro-fluidic carrier

    NARCIS (Netherlands)

    Scherrer, B.; Evans, A.; Santis-Alvarez, A. J.; Jiang, B.; Martynczuk, J.; Galinski, H.; Nabavi, M.; Prestat, M.; Tölke, R.; Bieberle, A.; Poulikakos, D.; Muralt, P.; Niedermann, P.; Dommann, A.; Maeder, T.; Heeb, P.; Straessle, V.; Muller, C.; Gauckler, L. J.

    2014-01-01

    Low temperature micro-solid oxide fuel cell (micro-SOFC) systems are an attractive alternative power source for small-size portable electronic devices due to their high energy efficiency and density. Here, we report on a thermally self-sustainable reformer micro-SOFC assembly. The device consists of

  6. Fabrication of micro DOE using micro tools shaped with focused ion beam.

    Science.gov (United States)

    Xu, Z W; Fang, F Z; Zhang, S J; Zhang, X D; Hu, X T; Fu, Y Q; Li, L

    2010-04-12

    A novel method is proposed to fabricate micro Diffractive Optical Elements (DOE) using micro cutting tools shaped with focused ion beam (FIB) milling. Micro tools with nanometric cutting edges and complicated shapes are fabricated by controlling the tool facet's orientation relative to the FIB. The tool edge radius of less than 30 nm is achieved for the nano removal of the work materials. Semi-circular micro tools and DOE-shaped micro tools are developed to fabricate micro-DOE and sinusoidal modulation templates. Experiments show that the proposed method can be a high efficient way in fabricating micro-DOE with nanoscale surface finishes.

  7. Micro system comprising 96 micro valves on a titer plate

    Science.gov (United States)

    Krabbe, S.; Flitsch, D.; Büchs, J.; Schomburg, W. K.

    2016-10-01

    A system of 96 micro valves has been developed and mounted on top of a 48-well micro titer plate providing two valves for each well controlling its air inlet and outlet. Testing of the valve system showed that all valves are working and are opened and closed reliably. A pneumatic system is switching inlet and outlet valves independently of each other. The geometry of the feed channels ensures an equal air flow through all wells, when the valves are open. Between the micro valves, one optical fibre was inserted through the lid of each well allowing measuring the oxygen partial pressure in the enclosed air volume by fluorescence sensor spots. Escherichia coli bacteria were grown inside the wells and their metabolism was observed by the oxygen partial pressure change due to respiration. In all 48 wells, the same oxygen transfer rate was observed within an averaged standard deviation of 1 mmol/L/h. The oxygen transfer rate differences compared to a macroscopic standard shake flask system were overall compatible within their uncertainties.

  8. The MicroObservatory Net

    Science.gov (United States)

    Brecher, K.; Sadler, P.

    1994-12-01

    A group of scientists, engineers and educators based at the Harvard-Smithsonian Center for Astrophysics (CfA) has developed a prototype of a small, inexpensive and fully integrated automated astronomical telescope and image processing system. The project team is now building five second generation instruments. The MicroObservatory has been designed to be used for classroom instruction by teachers as well as for original scientific research projects by students. Probably in no other area of frontier science is it possible for a broad spectrum of students (not just the gifted) to have access to state-of-the-art technologies that would allow for original research. The MicroObservatory combines the imaging power of a cooled CCD, with a self contained and weatherized reflecting optical telescope and mount. A microcomputer points the telescope and processes the captured images. The MicroObservatory has also been designed to be used as a valuable new capture and display device for real time astronomical imaging in planetariums and science museums. When the new instruments are completed in the next few months, they will be tried with high school students and teachers, as well as with museum groups. We are now planning to make the MicroObservatories available to students, teachers and other individual users over the Internet. We plan to allow the telescope to be controlled in real time or in batch mode, from a Macintosh or PC compatible computer. In the real-time mode, we hope to give individual access to all of the telescope control functions without the need for an "on-site" operator. Users would sign up for a specific period of time. In the batch mode, users would submit jobs for the telescope. After the MicroObservatory completed a specific job, the images would be e-mailed back to the user. At present, we are interested in gaining answers to the following questions: (1) What are the best approaches to scheduling real-time observations? (2) What criteria should be used

  9. Isolation of microRNA targets using biotinylated synthetic microRNAs

    DEFF Research Database (Denmark)

    Ørom, Ulf Andersson; Lund, Anders H

    2007-01-01

    MicroRNAs are small regulatory RNAs found in multicellular organisms where they post-transcriptionally regulate gene expression. In animals, microRNAs bind mRNAs via incomplete base pairings making the identification of microRNA targets inherently difficult. Here, we present a detailed method...... for experimental identification of microRNA targets based on affinity purification of tagged microRNAs associated with their targets. Udgivelsesdato: 2007-Oct...

  10. Integration of micro milling highspeed spindle on a microEDM-milling machine set-up

    DEFF Research Database (Denmark)

    De Grave, Arnaud; Hansen, Hans Nørgaard; Andolfatto, Loic

    2009-01-01

    In order to cope with repositioning errors and to combine the fast removal rate of micro milling with the precision and small feature size achievable with micro EDM milling, a hybrid micro-milling and micro-EDM milling centre was built and tested. The aim was to build an affordable set-up, easy...... by micro milling. Examples of test parts are shown and used as an experimental validation....

  11. Emotional context influences micro-expression recognition.

    Directory of Open Access Journals (Sweden)

    Ming Zhang

    Full Text Available Micro-expressions are often embedded in a flow of expressions including both neutral and other facial expressions. However, it remains unclear whether the types of facial expressions appearing before and after the micro-expression, i.e., the emotional context, influence micro-expression recognition. To address this question, the present study used a modified METT (Micro-Expression Training Tool paradigm that required participants to recognize the target micro-expressions presented briefly between two identical emotional faces. The results of Experiments 1 and 2 showed that negative context impaired the recognition of micro-expressions regardless of the duration of the target micro-expression. Stimulus-difference between the context and target micro-expression was accounted for in Experiment 3. Results showed that a context effect on micro-expression recognition persists even when the stimulus similarity between the context and target micro-expressions was controlled. Therefore, our results not only provided evidence for the context effect on micro-expression recognition but also suggested that the context effect might result from both the stimulus and valence differences.

  12. Introduction to micro- and nanooptics

    CERN Document Server

    Jahns, Jürgen

    2012-01-01

    This first textbook on both micro- and nanooptics introduces readers to the technological development, physical background and key areas.The opening chapters on the physics of light are complemented by chapters on refractive and diffractive optical elements. The internationally renowned authors present different methods of lithographic and nonlithographic fabrication of microoptics and introduce the characterization and testing of microoptics.The second part of the book is dedicated to optical microsystems and MEMS, optical waveguide structures and optical nanostructures, including pho

  13. Combinatorial microRNA target predictions

    DEFF Research Database (Denmark)

    Krek, Azra; Grün, Dominic; Poy, Matthew N.

    2005-01-01

    MicroRNAs are small noncoding RNAs that recognize and bind to partially complementary sites in the 3' untranslated regions of target genes in animals and, by unknown mechanisms, regulate protein production of the target transcript1, 2, 3. Different combinations of microRNAs are expressed...... in different cell types and may coordinately regulate cell-specific target genes. Here, we present PicTar, a computational method for identifying common targets of microRNAs. Statistical tests using genome-wide alignments of eight vertebrate genomes, PicTar's ability to specifically recover published micro......RNA targets, and experimental validation of seven predicted targets suggest that PicTar has an excellent success rate in predicting targets for single microRNAs and for combinations of microRNAs. We find that vertebrate microRNAs target, on average, roughly 200 transcripts each. Furthermore, our results...

  14. Micro-Kelvin cold molecules.

    Energy Technology Data Exchange (ETDEWEB)

    Strecker, Kevin E.; Chandler, David W.

    2009-10-01

    We have developed a novel experimental technique for direct production of cold molecules using a combination of techniques from atomic optical and molecular physics and physical chemistry. The ability to produce samples of cold molecules has application in a broad spectrum of technical fields high-resolution spectroscopy, remote sensing, quantum computing, materials simulation, and understanding fundamental chemical dynamics. Researchers around the world are currently exploring many techniques for producing samples of cold molecules, but to-date these attempts have offered only limited success achieving milli-Kelvin temperatures with low densities. This Laboratory Directed Research and Development project is to develops a new experimental technique for producing micro-Kelvin temperature molecules via collisions with laser cooled samples of trapped atoms. The technique relies on near mass degenerate collisions between the molecule of interest and a laser cooled (micro-Kelvin) atom. A subset of collisions will transfer all (nearly all) of the kinetic energy from the 'hot' molecule, cooling the molecule at the expense of heating the atom. Further collisions with the remaining laser cooled atoms will thermally equilibrate the molecules to the micro-Kelvin temperature of the laser-cooled atoms.

  15. Application of Flexible Micro Temperature Sensor in Oxidative Steam Reforming by a Methanol Micro Reformer

    Directory of Open Access Journals (Sweden)

    Yi-Man Lo

    2011-02-01

    Full Text Available Advances in fuel cell applications reflect the ability of reformers to produce hydrogen. This work presents a flexible micro temperature sensor that is fabricated based on micro-electro-mechanical systems (MEMS technology and integrated into a flat micro methanol reformer to observe the conditions inside that reformer. The micro temperature sensor has higher accuracy and sensitivity than a conventionally adopted thermocouple. Despite various micro temperature sensor applications, integrated micro reformers are still relatively new. This work proposes a novel method for integrating micro methanol reformers and micro temperature sensors, subsequently increasing the methanol conversion rate and the hydrogen production rate by varying the fuel supply rate and the water/methanol ratio. Importantly, the proposed micro temperature sensor adequately controls the interior temperature during oxidative steam reforming of methanol (OSRM, with the relevant parameters optimized as well.

  16. Sensitivity Jump of Micro Accelerometer Induced by Micro-fabrication Defects of Micro Folded Beams

    Directory of Open Access Journals (Sweden)

    Zhou Wu

    2016-08-01

    Full Text Available The abnormal phenomenon occurring in sensor calibration is an obstacle to product development but a useful guideline to product improvement. The sensitivity jump of micro accelerometers in the calibrating process is recognized as an important abnormal behavior and investigated in this paper. The characteristics of jumping output in the centrifuge test are theoretically and experimentally analyzed and their underlying mechanism is found to be related to the varied stiffness of supporting beam induced by the convex defect on it. The convex defect is normally formed by the lithography deviation and/or etching error and can result in a jumping stiffness of folded microbeams and further influence the sensitivity when a part of the bending beams is stopped from moving by two surfaces contacting. The jumping level depends on the location of convex and has nothing to do with the contacting properties of beam and defects. Then the location of defect is predicted by theoretical model and simulation and verified by the observation of micro structures under microscopy. The results indicate that the tested micro accelerometer has its defect on the beam with a distance of about 290μm from the border of proof mass block.

  17. microRNA Decay: Refining microRNA Regulatory Activity.

    Science.gov (United States)

    Pepin, Genevieve; Gantier, Michael P

    2016-01-01

    MicroRNAs (miRNAs) are short 19-25 nucleotide RNA molecules that impact on most biological processes by regulating the efficiency of messenger RNA (mRNA) translation. To date, most research activities have been focused on the control of miRNA expression and its functional consequences. Nonetheless, much remains unknown about the mechanisms affecting the level of specific miRNAs in the cell, a critical feature impacting their regulatory activity. This review focuses on the factors that regulate the abundance of miRNAs, including synthesis, post-transcriptional modifications, nucleases, target binding, and secretion.

  18. Micro

    African Journals Online (AJOL)

    2007-10-01

    Oct 1, 2007 ... Oduyebo, Department of Medical Microbiology and Parasitology, College of Medicine, .... bacteria were identified by standard laboratory methods ... Psychiatric ward in LUTH. ... RGH (theatre and the accident and emergency).

  19. Application of Ultra-Small Micro Grinding and Micro Milling Tools: Possibilities and Limitations

    Directory of Open Access Journals (Sweden)

    Benjamin Kirsch

    2017-08-01

    Full Text Available Current demands for flexible, individual microstructures in high quality result in high requirements for micro tools. As the tool size defines the minimum structure size, ultra-small tools are needed. To achieve tool diameters of 50 µm and lower, we investigate the complete manufacturing chain of micro machining. From the development of the machine tools and components needed to produce and apply the micro tools, the micro tools themselves, as well as the micro machining processes. Machine tools are developed with the possibility of producing the micro geometry (cutting edge design of micro tools as well as plating processes to produce super abrasive micro grinding tools. Applying these setups, we are able to produce ultra-small micro grinding and micro milling tools with typical diameters of 50 µm and down to 4 µm. However, the application of such tools is very challenging. The article presents possibilities and limitations in manufacturing the micro tools themselves as well as microstructures made with these tools. A special emphasis will be on the influence of the tool substrate in micro milling and grain sizes in micro grinding.

  20. Wafer integrated micro-scale concentrating photovoltaics

    Science.gov (United States)

    Gu, Tian; Li, Duanhui; Li, Lan; Jared, Bradley; Keeler, Gordon; Miller, Bill; Sweatt, William; Paap, Scott; Saavedra, Michael; Das, Ujjwal; Hegedus, Steve; Tauke-Pedretti, Anna; Hu, Juejun

    2017-09-01

    Recent development of a novel micro-scale PV/CPV technology is presented. The Wafer Integrated Micro-scale PV approach (WPV) seamlessly integrates multijunction micro-cells with a multi-functional silicon platform that provides optical micro-concentration, hybrid photovoltaic, and mechanical micro-assembly. The wafer-embedded micro-concentrating elements is shown to considerably improve the concentration-acceptance-angle product, potentially leading to dramatically reduced module materials and fabrication costs, sufficient angular tolerance for low-cost trackers, and an ultra-compact optical architecture, which makes the WPV module compatible with commercial flat panel infrastructures. The PV/CPV hybrid architecture further allows the collection of both direct and diffuse sunlight, thus extending the geographic and market domains for cost-effective PV system deployment. The WPV approach can potentially benefits from both the high performance of multijunction cells and the low cost of flat plate Si PV systems.

  1. Experimental identification of microRNA targets

    DEFF Research Database (Denmark)

    Ørom, Ulf Andersson; Lund, Anders H

    2009-01-01

    microRNAs are small RNAs that regulate protein synthesis post-transcriptionally. Animal microRNAs recognize their targets by incomplete base pairing to sequence motifs most often present in the 3' untranslated region of their target mRNAs. This partial complementarity vastly expands the repertoire...... of potential targets and constitutes a problem for computational target prediction. Although computational analyses have shed light on important aspects of microRNA target recognition, several questions remain regarding how microRNAs can recognize and regulate their targets. Forward experimental approaches...... allow for an unbiased study of microRNA target recognition and may unveil novel, rare or uncommon target binding patterns. In this review we focus on animal microRNAs and the experimental approaches that have been described for identification of their targets....

  2. Micro Evolutionary Processes and Adaptation

    Institute of Scientific and Technical Information of China (English)

    SHADMANOV R K; RUBAN I N; VOROPAEVA N L; SHADMANOVA A R

    2008-01-01

    @@ It would be well to note that in the absence of clear data about the formation of adaptation systems,or mechanisms of their occurrence,all that is recognized is the realization of the micro evolutionary processes.There is no well-defined connection between information exchange and formation of adaptation systems.Obviously,it occurs because mechanisms and systems reacting to any external actions are not considered from the point of view of "coexistence" of dynamic and static processes and structures.

  3. Micro-unmanned aerodynamic vehicle

    Science.gov (United States)

    Reuel, Nigel; Lionberger, Troy A.; Galambos, Paul C.; Okandan, Murat; Baker, Michael S.

    2008-03-11

    A MEMS-based micro-unmanned vehicle includes at least a pair of wings having leading wing beams and trailing wing beams, at least two actuators, a leading actuator beam coupled to the leading wing beams, a trailing actuator beam coupled to the trailing wing beams, a vehicle body having a plurality of fulcrums pivotally securing the leading wing beams, the trailing wing beams, the leading actuator beam and the trailing actuator beam and having at least one anisotropically etched recess to accommodate a lever-fulcrum motion of the coupled beams, and a power source.

  4. Contamination Study of Micro Pulsed Plasma Thruster

    Science.gov (United States)

    2008-03-01

    Micro propulsion vacuum facility ...................................................... 26 Figure 16. Oil Diffusion pump of the vacuum facility...increasing interest in the so-called micro - and nano -satellites, which are highly maneuverable and have lower cost. These small satellites are aimed to...option to create very small impulse bits for micro - and nano -satellites. Numerous researchers have studied PPTs but µPPTs are a new technology and need a

  5. CURRENT TRENDS OF MICRO- AND NANOMECHANICS

    Institute of Scientific and Technical Information of China (English)

    Wanlin Guo; Huiming Xie; Quanshui Zheng

    2009-01-01

    @@ Introduction Scaling down to the micro- and nanoscale is a strong current trend in the development of science and technology. 'Small is energy efficient and cost effective' has long been for the motto of the semiconductor industry, including micro- and nanoelectronics, micro-electro-mechanical systems (MEMS) and nano- electro-mechanical systems (NEMS). But shrinking to small scales brings big challenges to traditional disciplines, including mechanics.

  6. Fabrication of Micro Components by Electrochemical Deposition

    DEFF Research Database (Denmark)

    Tang, Peter Torben

    The main issue of this thesis is the combination of electrochemical deposition of metals and micro machining. Processes for electroplating and electroless plating of nickel and nickel alloys have been developed and optimised for compatibility with microelectronics and silicon based micromechanics...... of electrochemical machining and traditional machining is compared to micro machining techniques as performed in the field of microelectronics. Various practical solutions and equipment for electrochemical deposition of micro components are demonstrated, as well as the use and experience obtained utilising...

  7. Development of 3d micro-nano hybrid patterns using anodized aluminum and micro-indentation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hong Gue; Kwon, Jong Tae [Division of Mechanical Engineering and Mechatronics, Kangwon National University, 1 Kangwondaehakgil, Chunchon, Gangwon-do, 200-701 (Korea, Republic of); Seo, Young Ho [Division of Mechanical Engineering and Mechatronics, Kangwon National University, 1 Kangwondaehakgil, Chunchon, Gangwon-do, 200-701 (Korea, Republic of)], E-mail: mems@kangwon.ac.kr; Kim, Byeong Hee [Division of Mechanical Engineering and Mechatronics, Kangwon National University, 1 Kangwondaehakgil, Chunchon, Gangwon-do, 200-701 (Korea, Republic of)

    2008-07-31

    We developed a simple and cost-effective method of fabricating 3D micro-nano hybrid patterns in which micro-indentation is applied on the anodized aluminum substrate. Nano-patterns were formed first on the aluminum substrate, and then micro-patterns were fabricated by deforming the nano-patterned aluminum substrate. Hemispherical nano-patterns with a 150 nm-diameter on an aluminum substrate were fabricated by anodizing and alumina removing process. Then, micro-pyramid patterns with a side-length of 50 {mu}m were formed on the nano-patterns using micro-indentation. To verify 3D micro-nano hybrid patterns, we replicated 3D micro-nano hybrid patterns by a hot-embossing process. 3D micro-nano hybrid patterns may be used in nano-photonic devices and nano-biochips applications.

  8. Micro tube heat exchangers for Space Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mezzo fabricates micro tube heat exchangers for a variety of applications, including aerospace, automotive racing, Department of Defense ground vehicles, economizers...

  9. Photolithography and Micro-Fabrication/ Packaging Laboratories

    Data.gov (United States)

    Federal Laboratory Consortium — The Photolithography and Micro-Fabrication/Packaging laboratories provide research level semiconductor processing equipment and facilities that do not require a full...

  10. Modeling of a piezoelectric micro-scanner

    CERN Document Server

    Chaehoi, A; Cornez, D; Kirk, K

    2008-01-01

    Micro-scanners have been widely used in many optical applications. The micro-scanner presented in this paper uses multimorph-type bending actuators to tilt a square plate mirror. This paper presents a complete analytical model of the piezoelectric micro-scanner. This theoretical model based on strength of material equations calculates the force generated by the multimorphs on the mirror, the profile of the structure and the angular deflection of the mirror. The proposed model, used to optimize the design of the piezoelectric silicon micro-scanner, is intended for further HDL integration, allowing in this way system level simulation and optimization.

  11. Classification of assembly techniques for micro products

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; Tosello, Guido; Gegeckaite, Asta

    2005-01-01

    Industrial production of micro products to be introduced in the market has to be reliable, fast, carried out at a reasonable price and in an acceptable quantity. One of the crucial steps in the process chain related to micro product manufacture is the assembly phase. Here components are handled...... of components and level of integration are made. This paper describes a systematic characterization of micro assembly methods. This methodology offers the opportunity of a cross comparison among different techniques to gain a choosing principle of the favourable micro assembly technology in a specific case...

  12. Challenging the sustainability of micro products development

    DEFF Research Database (Denmark)

    De Grave, Arnaud; Olsen, Stig Irving

    2006-01-01

    Environmental aspects are one of the biggest concerns regarding the future of manufacturing and product development sustainability. Furthermore, micro products and micro technologies are often seen as the next big thing in terms of possible mass market trend and boom. Many questions are raised......) will be presented, together with some tools used in order to implement the concepts into design activities. Micro injection moulded components and MEMS are used as examples. Specificities of micro products will be investigated through a categorization in three levels: the end products, the whole production chain...

  13. Assembly planning at the micro scale

    Energy Technology Data Exchange (ETDEWEB)

    Feddema, J.T.; Xavier, P.; Brown, R.

    1998-05-14

    This paper investigates a new aspect of fine motion planning for the micro domain. As parts approach 1--10 {micro}m or less in outside dimensions, interactive forces such as van der Waals and electrostatic forces become major factors which greatly change the assembly sequence and path plans. It has been experimentally shown that assembly plans in the micro domain are not reversible, motions required to pick up a part are not the reverse of motions required to release a part. This paper develops the mathematics required to determine the goal regions for pick up, holding, and release of a micro-sphere being handled by a rectangular tool.

  14. Motion Control of Micro-/Nanomotors.

    Science.gov (United States)

    Teo, Wei Zhe; Pumera, Martin

    2016-10-10

    As we progress towards employing self-propelled micro-/nanomotors in envisioned applications such as cargo delivery, environmental remediation, and therapeutic treatments, precise control of the micro-/nanomotors direction and their speed is essential. In this Review, major emerging approaches utilized for the motion control of micro-/nanomotors have been discussed, together with the lastest publications describing these approaches. Future studies could incorporate investigations on micro-/nanomotors motion control in a real-world environment in which matrix complexity might disrupt successful manipulation of these small-scale devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Classification of assembly techniques for micro products

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; Tosello, Guido; Gegeckaite, Asta

    2005-01-01

    Industrial production of micro products to be introduced in the market has to be reliable, fast, carried out at a reasonable price and in an acceptable quantity. One of the crucial steps in the process chain related to micro product manufacture is the assembly phase. Here components are handled...... of components and level of integration are made. This paper describes a systematic characterization of micro assembly methods. This methodology offers the opportunity of a cross comparison among different techniques to gain a choosing principle of the favourable micro assembly technology in a specific case...

  16. Stretchable Micro-Electrode Array

    Energy Technology Data Exchange (ETDEWEB)

    Maghribi, M; Hamilton, J; Polla, D; Rose, K; Wilson, T; Krulevitch, P

    2002-03-08

    This paper focuses on the design consideration, fabrication processes and preliminary testing of the stretchable micro-electrode array. We are developing an implantable, stretchable micro-electrode array using polymer-based microfabrication techniques. The device will serve as the interface between an electronic imaging system and the human eye, directly stimulating retinal neurons via thin film conducting traces and electroplated electrodes. The metal features are embedded within a thin ({approx}50 micron) substrate fabricated using poly (dimethylsiloxane) (PDMS), a biocompatible elastomeric material that has very low water permeability. The conformable nature of PDMS is critical for ensuring uniform contact with the curved surface of the retina. To fabricate the device, we developed unique processes for metalizing PDMS to produce robust traces capable of maintaining conductivity when stretched (5%, SD 1.5), and for selectively passivating the conductive elements. An in situ measurement of residual strain in the PDMS during curing reveals a tensile strain of 10%, explaining the stretchable nature of the thin metalized devices.

  17. MicroRNAs in Metabolism

    DEFF Research Database (Denmark)

    Vienberg, Sara; Geiger, Julian; Madsen, Søren

    2017-01-01

    MicroRNAs (miRNAs) have within the past decade emerged as key regulators of metabolic homeostasis. Major tissues in intermediary metabolism important during development of the metabolic syndrome, such as β-cells, liver, skeletal and heart muscle as well as adipose tissue have all been shown to be...... diabetes and atherosclerosis stresses their potential as therapeutic targets. This review emphasizes current ideas and controversies within miRNA research in metabolism. This article is protected by copyright. All rights reserved.......MicroRNAs (miRNAs) have within the past decade emerged as key regulators of metabolic homeostasis. Major tissues in intermediary metabolism important during development of the metabolic syndrome, such as β-cells, liver, skeletal and heart muscle as well as adipose tissue have all been shown...... to be affected by miRNAs. In the pancreatic β-cell a number of miRNAs are important in maintaining the balance between differentiation and proliferation (miR-200 and miR-29 families) and insulin exocytosis in the differentiated state is controlled by miR-7, miR-375 and miR-335. MiR-33a and -33b play crucial...

  18. Laser surface micro-/nano-structuring by a simple transportable micro-sphere lens array

    NARCIS (Netherlands)

    Sedao, X.; Derrien, T.J.Y.; Romer, G.W.R.B.E.; Pathiraj, B.; Huis in 't Veld, A.J.

    2012-01-01

    A micro-sphere array optic was employed for laser surface micro-structuring. This array optic consists of a hexagonally close-packed monolayer of silica micro-spheres. It was organized through a self-assembly process and held together on a glass support, without using any adhesives. The array assemb

  19. Laser surface micro-/nano-structuring by a simple transportable micro-sphere lens array

    NARCIS (Netherlands)

    Sedao, X.; Derrien, T.J.Y.; Romer, G.W.R.B.E.; Pathiraj, B.; Huis in 't Veld, A.J.

    2012-01-01

    A micro-sphere array optic was employed for laser surface micro-structuring. This array optic consists of a hexagonally close-packed monolayer of silica micro-spheres. It was organized through a self-assembly process and held together on a glass support, without using any adhesives. The array

  20. Reference micro-objects and procedures to establish traceability in micro metrology

    DEFF Research Database (Denmark)

    Gasparin, Stefania; Tosello, Guido; Hansen, Hans Nørgaard

    2011-01-01

    The report presents methods and procedure to establish the traceability of measurements at both micro and sub-micro dimensional scales. Reference artefacts and new methodologies to ensure traceability of dimensional and geometrical 3D measurements (absolute dimensions below 3 mm, micro features w...

  1. Micro RNA and skin%Micro RNA与皮肤

    Institute of Scientific and Technical Information of China (English)

    许文嵘; 范卫新

    2010-01-01

    micro RNA(miRNA)是一种长约22 nt的非编码RNA,在众多生物体内已发现了许多种miRNA,它们大多数在进化上高度保守,在生物体的发育,细胞的增殖、分化、凋亡以及肿瘤的发生中起着重要的作用.皮肤作为人体最大的一个器官,miRNA在其中也起了许多重要作用.该文就近年来miRNA在皮肤病学中的研究进展作一综述.

  2. Micro-assembly of a Vascular-like Micro-channel with Railed Micro-robot Team-coordinated Manipulation

    Directory of Open Access Journals (Sweden)

    Huaping Wang

    2014-07-01

    strategies were evaluated based on the assembly of micro-donuts. Through the novel, designed, concentric movement of the multi-manipulators along the rail, arbitrary change of the approaching angle and the coordination posture was achieved to improve the micro-assembly’s flexibility. The operation range for every micromanipulator in different coordinated manipulation modes was analysed to avoid the breakdown of the assembled 3D structure. The image processing for the target location and end-effector identification was conducted to improve assembly efficiency in the micro-robot-team system. Finally, the assembly of the cellular vascular-like micro-channel was achieved with coordinated manipulation in the rail- guided micro-robot-team system.

  3. Integrated Micro Product and Technology Development

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard

    2003-01-01

    The paper addresses the issues of integrated micro product and technology development. The implications of the decisions in the design phase on the subsequent manufacturing processes are considered vital. A coherent process chain is a necessary prerequisite for the realisation of the industrial...... potential of micro technology....

  4. Characterization of Micro-arc Oxidized Titanium

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The observation of the sparkling discharges during the micro-arc oxidation process in KOH aqueous electrolyte was achieved. The change of surface morphology was progressively observed and a plausible pore formation mechanism is proposed. Cell proliferation and ALP activity of micro-arc oxidized titanium was evaluated by human body derived osteoblasts and slightly better than those of blasted surface.

  5. Report on tolerancing guidelines for micro manufacturing

    DEFF Research Database (Denmark)

    Gasparin, Stefania; Tosello, Guido; Hansen, Hans Nørgaard

    2011-01-01

    The present report underlines some problematic aspects of the micro manufacturing in order to develop tolerancing guidelines based on the industrial needs of the partners in the project. Some solutions were given through the investigation and characterization of three different micro-nano injection...

  6. Integrated Micro Product and Technology Development

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard

    2003-01-01

    The paper addresses the issues of integrated micro product and technology development. The implications of the decisions in the design phase on the subsequent manufacturing processes are considered vital. A coherent process chain is a necessary prerequisite for the realisation of the industrial...... potential of micro technology....

  7. The Aarhus Ion Micro-Trap Project

    DEFF Research Database (Denmark)

    Miroshnychenko, Yevhen; Nielsen, Otto; Poulsen, Gregers

    and installed in an ultra high vacuum chamber, which includes an ablation oven for all-optical loading of the trap [2]. The next steps on the project are to demonstrate the operation of the micro-trap and the cooling of ions using fiber delivered light. [1] D. Grant, Development of Micro-Scale Ion traps, Master...

  8. Micro-optics: manufacturing and characterization

    Science.gov (United States)

    Voelkel, R.; Eisner, M.; Weible, K. J.

    2005-10-01

    Wafer-based manufacturing of Micro-Optics is based on standard technologies from Semiconductor Industry, like resist coating, lithography, reactive ion etching, deposition, sputtering, and lift-off. These well-established technologies allow the manufacturing of almost any Micro-Optics' structure shape. The excellence of the Micro-Optics component depends much on the proper choice of the manufacturing equipment and the process control. As all processes are standard Semiconductor technology, the quality is merely a question of the budget and the optimization effort. For characterization and testing, the current situation is different. Neither the test equipment from Semiconductor industry nor the test equipment from classical optics manufacturing is suitable to for Micro-Optics. Most of test instruments Micro-Optics industry is using today have been developed by research institutes or by the manufacturing companies themselves. As Micro-Optics is still a niche market, all instruments are built in small series. This lack of suitable test equipment is a major problem for the Micro-Optics industry today. All process optimization in manufacturing is closely related to the capability to measure the quality of the products. We report on the state of the art in wafer-based manufacturing and summarize the standard characterization tools for Micro-Optics.

  9. Micro hydro-electric power stations

    Energy Technology Data Exchange (ETDEWEB)

    Monition, L.; Le Nir, M.; Roux, J.

    1984-01-01

    This book provides a discussion of all aspects of hydro-power exploitation using micro-power stations. It offers guidance to techniques for assessing the power available from a given stream, designing and building siteworks, selecting the appropriate turbine types for given conditions, and measuring and controlling environmental hazards associated with micro-hydro installations.

  10. Can micro-volunteering help in Africa?

    CSIR Research Space (South Africa)

    Butgereit, L

    2013-05-01

    Full Text Available is convenient to the micro-volunteer, and in small pieces of time (bitesized). This paper looks at a micro-volunteering project where participants can volunteer for five to ten minutes at a time using a smart phone and assist pupils with their mathematics....

  11. Report on tolerancing guidelines for micro manufacturing

    DEFF Research Database (Denmark)

    Gasparin, Stefania; Tosello, Guido; Hansen, Hans Nørgaard

    2011-01-01

    The present report underlines some problematic aspects of the micro manufacturing in order to develop tolerancing guidelines based on the industrial needs of the partners in the project. Some solutions were given through the investigation and characterization of three different micro-nano injecti...... moulded components: a toggle for hearing aid application, CD/DVD/HD-DVD and, finally, Fresnel lenses....

  12. RFP for CNES micro satellite program

    DEFF Research Database (Denmark)

    Jørgensen, John Leif; Jørgensen, Finn E; Betto, Maurizio

    1999-01-01

    This document descibes the ASC STAR TRACKER (performance, functionality, requirements etc.) to the Centre National d'Etudes Spatiales (CNES) for their micro Satellites.......This document descibes the ASC STAR TRACKER (performance, functionality, requirements etc.) to the Centre National d'Etudes Spatiales (CNES) for their micro Satellites....

  13. Micro/nanoscale continuous printing: direct-writing of wavy micro/nano structures via electrospinning

    Science.gov (United States)

    Fang, Feiyu; Du, Zefeng; Zeng, Jun; Zhu, Ziming; Chen, Xin; Chen, Xindu; Lv, Yuanjun; Wang, Han

    2015-07-01

    Micro/nanofibers that are created by direct-writing using an electrospinning (ES) technique have aroused much recent attention, owing to their intriguing physical properties and great potential as building blocks for micro/nanoscale devices. In this work, a wavy direct-writing (WDW) process was developed to directly write wavy micro/nanostructures suitable for the fabrication of micro/nanoscale devices. The low voltage WDW technique is anticipated to be useful for a broad range of applications including flexible/stretchable electronics, micro optoelectronics, nano-antennas, microelectromechanical systems (MEMS), and biomedical engineering.

  14. Micro powder injection molding——large scale production technology for micro-sized components

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Micro powder injection molding (μPIM),a miniaturized variant of powder injection molding,has advantages of shape complexity,applicability to many materials and good mechanical properties. Co-injection molding has been realized between met-als and ceramics on micro components,which become the first breakthrough within the PIM field. Combined with the prominent characteristics of high features/cost ratio,micro powder injection molding becomes a potential technique for large scale production of intricate and three-dimensional micro components or micro-structured components in microsystems technology (MST) field.

  15. Micro injection moulding process validation for high precision manufacture of thermoplastic elastomer micro suspension rings

    DEFF Research Database (Denmark)

    Calaon, M.; Tosello, G.; Elsborg Hansen, R.

    Micro injection moulding (μIM) is one of the most suitable micro manufacturing processes for flexible mass-production of multi-material functional micro components. The technology was employed in this research used to produce thermoplastic elastomer (TPE) micro suspension rings identified...... as critical component in micro acoustic applications (e.g. phono cartridges, see Figure 1a). The suspension ring holds in place the preassembled aluminium cantilever, magnet and diamond tip seen (see Figure 1b and 1c). The specific damping properties of the TPE material reduces vibrations differently depended...

  16. MicroRNAs in neurodegeneration.

    Science.gov (United States)

    Bushati, Natascha; Cohen, Stephen M

    2008-06-01

    microRNAs (miRNAs) act as post-transcriptional regulators of gene expression in diverse cellular and developmental processes. Many miRNAs are expressed specifically in the central nervous system, where they have roles in differentiation, neuronal survival, and potentially also in plasticity and learning. The absence of miRNAs in a variety of specific postmitotic neurons can lead to progressive loss of these neurons and behavioral defects reminiscent of the phenotypes seen in the pathologies of neurodegenerative diseases. Here, we review recent studies which provide a link between miRNA function and neurodegeneration. We also discuss evidence which might suggest involvement of miRNAs in the emergence or progression of neurodegenerative diseases.

  17. Trophoblasts, invasion and micro RNA

    Directory of Open Access Journals (Sweden)

    Ludivine eDoridot

    2013-11-01

    Full Text Available MicroRNAs (miRNAs have recently become essential actors in various fields of physiology and medicine, especially as easily accessible circulating biomarkers, or as modulators of cell differentiation. To this respect, terminal differentiation of trophoblasts (the characteristic cells of the placenta in Therian mammals into syncytiotrophoblast, villous trophoblast or extravillous trophoblast constitutes a good example of such a choice, where miRNAs have recently been shown to play an important role. The aim of this review is to provide a snapshot of what is known today in placentation mechanisms that are mediated by miRNA, under the angles of materno-foetal immune dialogue regulation, trophoblast differentiation and angiogenesis at the materno-foetal interface. Also, two aspects of regulation of these issues will be highlighted: the part played by oxygen concentration and the specific function of imprinted genes in the developing placenta.

  18. Micro-modulated luminescence tomography

    CERN Document Server

    Cong, Wenxiang; Wang, Chao; Wang, Ge

    2013-01-01

    Imaging depth of optical microscopy has been fundamentally limited to millimeter or sub-millimeter due to light scattering. X-ray microscopy can resolve spatial details of few microns deeply inside a sample but the contrast resolution is still inadequate to depict heterogeneous features at cellular or sub-cellular levels. To enhance and enrich biological contrast at large imaging depth, various nanoparticles are introduced and become essential to basic research and molecular medicine. Nanoparticles can be functionalized as imaging probes, similar to fluorescent and bioluminescent proteins. LiGa5O8:Cr3+ nanoparticles were recently synthesized to facilitate luminescence energy storage with x-ray pre-excitation and the subsequently stimulated luminescence emission by visible/near-infrared (NIR) light. In this paper, we suggest a micro-modulated luminescence tomography (MLT) approach to quantify a nanophosphor distribution in a thick biological sample with high resolution. Our numerical simulation studies demonst...

  19. MEMS Based Micro Aerial Vehicles

    Science.gov (United States)

    Joshi, Niranjan; Köhler, Elof; Enoksson, Peter

    2016-10-01

    Designing a flapping wing insect robot requires understanding of insect flight mechanisms, wing kinematics and aerodynamic forces. These subsystems are interconnected and their dependence on one another affects the overall performance. Additionally it requires an artificial muscle like actuator and transmission to power the wings. Several kinds of actuators and mechanisms are candidates for this application with their own strengths and weaknesses. This article provides an overview of the insect scaled flight mechanism along with discussion of various methods to achieve the Micro Aerial Vehicle (MAV) flight. Ongoing projects in Chalmers is aimed at developing a low cost and low manufacturing time MAV. The MAV design considerations and design specifications are mentioned. The wings are manufactured using 3D printed carbon fiber and are under experimental study.

  20. Dysregulated microRNAs in neurodegenerative disorders.

    Science.gov (United States)

    Lau, Pierre; de Strooper, Bart

    2010-09-01

    The complexity of the nervous system arises in part, from the large diversity of neural cell types that support the architecture of neuronal circuits. Recent studies have highlighted microRNAs as important players in regulating gene expression at the post-transcriptional level and therefore the phenotype of neural cells. A link between microRNAs and neurodegenerative diseases such as Alzheimer's disease, Huntington's disease and Parkinson's disease is becoming increasingly evident. Here, we discuss microRNAs in neurodegeneration, from the fruit fly and mouse utilized as experimental models to dysregulated microRNAs in human neurodegenerative disorders. We propose that studying microRNAs and their mRNA targets in the context of neurodegeneration will significantly contribute to the identification of proteins important for neuronal function and might reveal underlying molecular networks that drive these diseases.

  1. Biologically Inspired Micro-Flight Research

    Science.gov (United States)

    Raney, David L.; Waszak, Martin R.

    2003-01-01

    Natural fliers demonstrate a diverse array of flight capabilities, many of which are poorly understood. NASA has established a research project to explore and exploit flight technologies inspired by biological systems. One part of this project focuses on dynamic modeling and control of micro aerial vehicles that incorporate flexible wing structures inspired by natural fliers such as insects, hummingbirds and bats. With a vast number of potential civil and military applications, micro aerial vehicles represent an emerging sector of the aerospace market. This paper describes an ongoing research activity in which mechanization and control concepts for biologically inspired micro aerial vehicles are being explored. Research activities focusing on a flexible fixed- wing micro aerial vehicle design and a flapping-based micro aerial vehicle concept are presented.

  2. Challenging the sustainability of micro products development

    DEFF Research Database (Denmark)

    De Grave, Arnaud; Olsen, Stig Irving

    2006-01-01

    Environmental aspects are one of the biggest concerns regarding the future of manufacturing and product development sustainability. Furthermore, micro products and micro technologies are often seen as the next big thing in terms of possible mass market trend and boom. Many questions are raised...... regarding the impact of size for recycling or environment. Indeed micro production is often seen as environmental friendly thanks to the small amount of material used. Such a statement can be misleading. In this article EcoDesign or Design for Environment (DFE) and Life Cycle Assessment (LCA......) will be presented, together with some tools used in order to implement the concepts into design activities. Micro injection moulded components and MEMS are used as examples. Specificities of micro products will be investigated through a categorization in three levels: the end products, the whole production chain...

  3. Precision moulding of polymer micro components

    DEFF Research Database (Denmark)

    Tosello, Guido

    2008-01-01

    at micro scale, of machine’s dynamic behaviour implementation and of micro geometry modelling was shown in a quantitative study. Insert moulding and hot embossing processes were investigated for the manufacturing of multi-material miniaturized components. A mould was developed and validated......The present research work contains a study concerning polymer micro components manufacturing by means of the micro injection moulding (µIM) process. The overall process chain was considered and investigated during the project, including part design and simulation, tooling, process analysis, part...... optimization, quality control, multi-material solutions. A series of experimental investigations were carried out on the influence of the main µIM process factors on the polymer melt flow within micro cavities. These investigations were conducted on a conventional injection moulding machine adapted...

  4. Improving metrology for micro-optics manufacturing

    Science.gov (United States)

    Davies, Angela D.; Bergner, Brent C.; Gardner, Neil W.

    2003-11-01

    Metrology is one of the critical enabling technologies for realizing the full market potential for micro-optical systems. Measurement capabilities are currently far behind present and future needs. Much of today"s test equipment was developed for the micro-electronics industry and is not optimized for micro-optic materials and geometries. Metrology capabilities currently limit the components that can be realized, in many cases. Improved testing will be come increasingly important as the technology moves to integration where it will become important to "test early and test often" to achieve high yields. In this paper, we focus on micro-refractive components in particular, and describe measurement challenges for this class of components and current and future needs. We also describe a new micro-optics metrology research program at UNC Charlotte under the Center for Precision Metrology and the new Center for Optoelectronics and Optical Communications to address these needs.

  5. Laser beam micro-milling of micro-channels in aerospace alloys

    CERN Document Server

    Ahmed, Naveed; Al-Ahmari, Abdulrahman

    2017-01-01

    This volume is greatly helpful to micro-machining and laser engineers as it offers obliging guidelines about the micro-channel fabrications through Nd:YAG laser beam micro-milling. The book also demonstrates how the laser beam micro-milling behaves when operating under wet conditions (under water), and explores what are the pros and cons of this hybrid technique. From the predictive mathematical models, the readers can easily estimate the resulting micro-channel size against the desired laser parametric combinations. The book considers micro-channels in three highly important research materials commonly used in aerospace industry: titanium alloy Ti-6Al-4V, nickel alloy Inconel 718 and aluminum alloy AA 2024. Therefore, the book is highly practicable in the fields of micro-channel heat exchangers, micro-channel aerospace turbine blades, micro-channel heat pipes, micro-coolers and micro-channel pulsating heat plates. These are frequently used in various industries such as aerospace, automotive, biomedical and m...

  6. Toward the promise of microRNAs - Enhancing reproducibility and rigor in microRNA research.

    Science.gov (United States)

    Witwer, Kenneth W; Halushka, Marc K

    2016-11-01

    The fields of applied and translational microRNA research have exploded in recent years as microRNAs have been implicated across a spectrum of diseases. MicroRNA biomarkers, microRNA therapeutics, microRNA regulation of cellular physiology and even xenomiRs have stimulated great interest, which have brought many researchers into the field. Despite many successes in determining general mechanisms of microRNA generation and function, the application of microRNAs in translational areas has not had as much success. It has been a challenge to localize microRNAs to a given cell type within tissues and assay them reliably. At supraphysiologic levels, microRNAs may regulate hosts of genes that are not the physiologic biochemical targets. Thus the applied and translational microRNA literature is filled with pitfalls and claims that are neither scientifically rigorous nor reproducible. This review is focused on increasing awareness of the challenges of working with microRNAs in translational research and recommends better practices in this area of discovery.

  7. IUTAM-Symposium on The Generalized Cosserat Continuum and the Continuum Theory of Dislocations with Applications

    CERN Document Server

    1968-01-01

    5 The symposium was held in Freudenstadt from 28\\h to 31 \\ ofAugust st nd 1967 and in Stuttgart from 1 to 2 of September 1967. The proposal to hold this symposium originated with the German Society of Applied Mathematics and Mechanics (GAMM) late in 1964 and was examined by a committee of IUTAM especially appointed for this purpose. The basis of this examination was a report in which the present situation in the field and the possible aims of the symposium were surveyed. Briefly, the aims of the symposium were stated to be 1. the unification of the various approaches developed in recent years with the aim of penetrating into the microscopic world of matter by means of continuum theories; 2. the bridging of the gap between microscopic (or atomic) research on mechanics on one hand, and the phenomenological (or continuum mechanical) approach on the other hand; 3. the physical interpretation and the relation to actual material behaviour of the quantities and laws introduced into the new theories, together with ap...

  8. Micro computed tomography for vascular exploration

    Directory of Open Access Journals (Sweden)

    Zhuang Zhen W

    2010-03-01

    Full Text Available Abstract Vascular exploration of small animals requires imaging hardware with a very high spatial resolution, capable of differentiating large as well as small vessels, in both in vivo and ex vivo studies. Micro Computed Tomography (micro-CT has emerged in recent years as the preferred modality for this purpose, providing high resolution 3D volumetric data suitable for analysis, quantification, validation, and visualization of results. The usefulness of micro-CT, however, can be adversely affected by a range of factors including physical animal preparation, numerical quantification, visualization of results, and quantification software with limited possibilities. Exacerbating these inherent difficulties is the lack of a unified standard for micro-CT imaging. Most micro-CT today is aimed at particular applications and the software tools needed for quantification, developed mainly by imaging hardware manufacturers, lack the level of detail needed to address more specific aims. This review highlights the capabilities of micro-CT for vascular exploration, describes the current state of imaging protocols, and offers guidelines and suggestions aimed at making micro-CT more accurate, replicable, and robust.

  9. Fabrication of micro metallic valve and pump

    Science.gov (United States)

    Yang, Ming; Kabasawa, Yasunari; Ito, Kuniyoshi

    2010-03-01

    Fabrication of micro devices by using micro metal forming was proposed by the authors. We developed a desktop servo-press machine with precise tooling system. Precise press forming processes including micro forging and micro joining has been carried out in a progressive die. In this study, micro metallic valve and pump were fabricated by using the precise press forming. The components are made of sheet metals, and assembled in to a unit in the progressive die. A micro check-valve with a diameter of 3mm and a length of 3.2mm was fabricated, and the property of flow resistance was evaluated. The results show that the check valve has high property of leakage proof. Since the valve is a unit parts with dimensions of several millimeters, it has advantage to be adapted to various pump design. Here, two kinds of micro pumps with the check-valves were fabricated. One is diaphragm pump actuated by vibration of the diaphragm, and another is tube-shaped pump actuated by resonation. The flow quantities of the pumps were evaluated and the results show that both of the pumps have high pumping performance.

  10. Development of micro power generators - A review

    Energy Technology Data Exchange (ETDEWEB)

    Chou, S.K.; Yang, W.M.; Chua, K.J.; Li, J. [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Zhang, K.L. [Department of Manufacturing Engineering and Engineering Management, City University of Hong Kong, 83 Tat Chee Avenue (China)

    2011-01-15

    The demand for energy sources that are compact, lightweight and powerful has significantly increased in recent years. Traditional chemical batteries which are highly developed are unable to meet the demand for high energy intensity. This gap is expected to widen in the future as electronic devices need more power to support enhanced functionalities. Hydrocarbon fuels have energy densities much greater than the best batteries. Therefore, taking advantage of the high energy density of chemical fuels to generate power becomes an attractive technological alternative to batteries. To address the growing demand for smaller scale and higher energy density power sources, various combustion-based micro power generators are being developed around the world. This review paper provides an update on recent progresses and developments in micro-scale combustion and micro power generators. The paper, broadly divided into four main sections, begins with a review of various methods to enhance and stabilize the combustion at micro-scale, subsequently improving the efficiency. This is followed by a description of various micro-thermophotovoltaic power generators. The third section focuses on MEMS based solid propellant micro-propulsion system. Lastly, a brief review is made to other micro power generators. (author)

  11. Updating the Micro-Tom TILLING platform.

    Science.gov (United States)

    Okabe, Yoshihiro; Ariizumi, Tohru; Ezura, Hiroshi

    2013-03-01

    The dwarf tomato variety Micro-Tom is regarded as a model system for functional genomics studies in tomato. Various tomato genomic tools in the genetic background of Micro-Tom have been established, such as mutant collections, genome information and a metabolomic database. Recent advances in tomato genome sequencing have brought about a significant need for reverse genetics tools that are accessible to the larger community, because a great number of gene sequences have become available from public databases. To meet the requests from the tomato research community, we have developed the Micro-Tom Targeting-Induced Local Lesions IN Genomes (TILLING) platform, which is comprised of more than 5000 EMS-mutagenized lines. The platform serves as a reverse genetics tool for efficiently identifying mutant alleles in parallel with the development of Micro-Tom mutant collections. The combination of Micro-Tom mutant libraries and the TILLING approach enables researchers to accelerate the isolation of desirable mutants for unraveling gene function or breeding. To upgrade the genomic tool of Micro-Tom, the development of a new mutagenized population is underway. In this paper, the current status of the Micro-Tom TILLING platform and its future prospects are described.

  12. Dual-energy micro-CT imaging of pulmonary airway obstruction: correlation with micro-SPECT

    Science.gov (United States)

    Badea, C. T.; Befera, N.; Clark, D.; Qi, Y.; Johnson, G. A.

    2014-03-01

    To match recent clinical dual energy (DE) CT studies focusing on the lung, similar developments for DE micro-CT of the rodent lung are required. Our group has been actively engaged in designing pulmonary gating techniques for micro- CT, and has also introduced the first DE micro-CT imaging method of the rodent lung. The aim of this study was to assess the feasibility of DE micro-CT imaging for the evaluation of airway obstruction in mice, and to compare the method with micro single photon emission computed tomography (micro-SPECT) using technetium-99m labeled macroaggregated albumin (99mTc-MAA). The results suggest that the induced pulmonary airway obstruction causes either atelectasis, or air-trapping similar to asthma or chronic bronchitis. Atelectasis could only be detected at early time points in DE micro-CT images, and is associated with a large increase in blood fraction and decrease in air fraction. Air trapping had an opposite effect with larger air fraction and decreased blood fraction shown by DE micro-CT. The decrease in perfusion to the hypoventilated lung (hypoxic vasoconstriction) is also seen in micro-SPECT. The proposed DE micro-CT technique for imaging localized airway obstruction performed well in our evaluation, and provides a higher resolution compared to micro-SPECT. Both DE micro-CT and micro-SPECT provide critical, quantitative lung biomarkers for image-based anatomical and functional information in the small animal. The methods are readily linked to clinical methods allowing direct comparison of preclinical and clinical results.

  13. Micro Nano Replication Processes and Applications

    CERN Document Server

    Kang, Shinill

    2012-01-01

    This book is an introduction to the fundamentals and processes for micro and nano molding for plastic components. In addition to the basics, the book covers applications details and examples. The book helps both students and professionals to understand and work with the growing tools of molding and uses for micro and nano-sized plastic parts.Provides a comprehensive presentation on fundamentals and practices of manufacturing for micro / nano sized plastics partsCovers a relatively new but fast-growing field that is impacting any industry using plastic parts in their products (electronics, tele

  14. Micro-fuel cell power sources

    Energy Technology Data Exchange (ETDEWEB)

    Morse, Jeffrey D. [Center for Meso, Micro, and Nano Technology, Lawrence Livermore National Laboratory, 7000 East Avenue, L-222, Livermore, CA 94550, (United States)

    2007-01-19

    This paper presents a review and discussion of micro-fuel cell technologies, providing insight into the innovations that have been made to date. Discussion of concepts and results leading towards increased levels of integration and performance for micro-fuel cell systems will elucidate the potential of thin film and microfabrication methods in meeting the challenges and requirements necessary for consumer applications. While the amount of literature in this area is substantial, a representative sampling of key developments will be presented in this paper, in order to gain a sense of the design methodologies being implemented for micro-fuel cell power sources. (Author)

  15. Micro-transactions for concurrent data structures

    DEFF Research Database (Denmark)

    Meawad, Fadi; Iyer, Karthik; Schoeberl, Martin;

    2013-01-01

    Transactional memory is a promising technique for enforcing disciplined access to shared data in a multiprocessor system. Transactional memory simplifies the implementation of a variety of concurrent data structures. In this paper, we study the benefits of a modest, real-time aware, hardware...... implementation of transactional memory that we call micro-transactions. In particular, we argue that hardware support for micro-transactions allows us to efficiently implement certain data structures. Those data structures are difficult to realize with the atomic operations provided by stock hardware and provide......, atomic instructions, and micro-transactions. Our results suggest that transactional memory is an interesting alternative to traditional concurrency control mechanisms....

  16. Micro turbine engines for drones propulsion

    Science.gov (United States)

    Dutczak, J.

    2016-09-01

    Development of micro turbine engines began from attempts of application of that propulsion source by group of enthusiasts of aviation model making. Nowadays, the domain of micro turbojet engines is treated on a par with “full size” aviation constructions. The dynamic development of these engines is caused not only by aviation modellers, but also by use of micro turbojet engines by army to propulsion of contemporary drones, i.e. Unmanned Aerial Vehicles (UAV) or Unmanned Aerial Systems (UAS). On the base of selected examples the state of art in the mentioned group of engines has been presented in the article.

  17. Micro satellite mapping of plant genomes

    Directory of Open Access Journals (Sweden)

    Prodanović Slaven

    2001-01-01

    Full Text Available Micro satellites are DNA markers, based on the repeated nucleotide sequences number polymorphism. They belong to a group of PCR markers and are mainly used as an addition to other types of markers. Their characteristics and technical aspects of their application are discussed in the present study. Furthermore, some results obtained by the use of the micro satellite DNA in genetic mapping of plant genomes are also presented. Although micro satellites provide the identification of genotypes within a species, inadequacy of comparative mapping of different species is their serious blemish. .

  18. RESEARCH OF MICRO ELECTRO DISCHARGE MACHININGEQUIPMENT AND PROCESS TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Micro electro discharge machining (micro EDM) is a feasible way to manufacture micro structures and has potential application in advanced industrial fields. For the realization of micro EDM, it is necessary to pay careful attention to its equipment design and the development of process techniques. The present status of research and development of micro EDM equipment and process techniques is overviewed. A micro electro discharge machine incorporated with an inchworm type of micro feed mechanism is introduced, and a micro electro discharge machine for drilling micro holes suitable to industrial use is also introduced. Some of the machining experiments carried out on the micro EDM prototypes are shown and the feasibility of the micro EDM technology to practical use is discussed.

  19. Epigenetic microRNA Regulation

    DEFF Research Database (Denmark)

    Wiklund, Erik Digman

    2011-01-01

    MicroRNAs (miRNAs) are small non-coding RNAs (ncRNAs) that negatively regulate gene expression post-transcriptionally by binding to complementary sequences in the 3’UTR of target mRNAs in the cytoplasm. However, recent evidence suggests that certain miRNAs are enriched in the nucleus......, and their targets do not seem restricted to mRNA 3’UTRs. Therefore, miRNAs are predicted to have a variety functions throughout mammalian cells. MiRNA genes appear to be regulated in much the same way as coding genes, but current insight into transcriptional miRNA control lacks detail, as mapping miRNA promoters...... and confirming transcriptional start sites can be difficult. Epigenetics, gene regulatory and DNA modification mechanisms not involving a change to the primary sequence, have been implied in the regulation of a number of miRNA loci. Both epigenetic and miRNA signatures are broadly altered in cancer...

  20. MICRO AUTO GASIFICATION SYSTEM: EMISSIONS ...

    Science.gov (United States)

    A compact, CONEX-housed waste to energy unit, Micro Auto Gasification System (MAGS), was characterized for air emissions from burning of military waste types. The MAGS unit is a dual chamber gasifier with a secondary diesel-fired combustor. Eight tests were conducted with multiple waste types in a 7-day period at the Kilauea Military Camp in Hawai’i. The emissions characterized were chosen based on regulatory emissions limits as well as their ability to cause adverse health effects on humans: particulate matter (PM), mercury, heavy metals, volatile organic compounds (VOCs), polyaromatic hydrocarbons (PAHs), and polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Three military waste feedstock compositions reflecting the variety of wastes to be encountered in theatre were investigated: standard waste (SW), standard waste with increased plastic content (HP), standard waste without SW food components but added first strike ration (FSR) food and packaging material (termed FSR). A fourth waste was collected from the Kilauea dumpster that served the dining facility and room lodging (KMC). Limited scrubber water and solid ash residue samples were collected to obtain a preliminary characterization of these effluents/residues.Gasifying SW, HP, and KMC resulted in similar PCDD/PCDF stack concentrations, 0.26-0.27 ng TEQ/m3 at 7% O2, while FSR waste generated a notably higher stack concentration of 0.68 ng TEQ/m3 at 7% O2. The PM emission

  1. MicroRNAs and spermatogenesis.

    Science.gov (United States)

    Kotaja, Noora

    2014-06-01

    In mammals, male gametes are produced inside the testis by spermatogenesis, which has three phases: mitotic proliferation of spermatogonia, meiosis of spermatocytes, and haploid differentiation of spermatids. The genome of male germ cells is actively transcribed to produce phase-specific gene expression patterns. Male germ cells have a complex transcriptome. In addition to protein-coding messenger RNAs, many noncoding RNAs, including microRNAs (miRNAs), are produced. The miRNAs are important regulators of gene expression. They function mainly post-transcriptionally to control the stability or translation of their target messenger RNAs. The miRNAs are expressed in a cell-specific manner during spermatogenesis to participate in the control of each step of male germ cell differentiation. Genetically modified mouse models have demonstrated the importance of miRNA pathways for normal spermatogenesis, and functional studies have been designed to dissect the roles of specific miRNAs in distinct cell types. Clinical studies have exploited the well-defined expression profiles of miRNAs, and human spermatozoal or seminal plasma miRNAs have been explored as potential biomarkers for male factor infertility. This review article discusses the current findings that support the central role of miRNAs in the regulation of spermatogenesis and male fertility.

  2. Measuring In-Plane Micro-Motion of Micro-Structure Using Optical Flow

    Institute of Scientific and Technical Information of China (English)

    JIN Cuiyun; JIN Shijiu; LI Dachao; WANG Jianlin

    2009-01-01

    Optical flow method is one of the most important methods of analyzing motion images.Optical flow field is used to analyze characteristics of motion objects.According to motion features of micro-electronic mechanical system(MEMS)micro-structure,the optical algorithm based on label field and neighborhood optimization is presented to analyze the in-plane micro-motion of micro-structure.Firstly,high speed motion states for each frequency segment of micro-structure in cyclic motion are frozen based on stroboscopic principle.Thus a series of image sequences,and can obtain reliable and precise optical field and reduce computing time.As micro-resonator of urement precision of the presented algorithm is high,and measurement repeatability reaches 40 am under the same experiment condition.

  3. Design and testing of micro fluidic chemical analysis chip integrated with micro valveless pump

    Institute of Scientific and Technical Information of China (English)

    FU; Xin; XIE; Haibo; YANG; Huayong; JIA; Zhijian; FANG; Qun

    2005-01-01

    A new structure and working principle of the chip integrated with micro valveless pump for capillary electrophoresis was proposed in this paper. The micro valveless pump with plane structure has advantages of simple structure, and the process technology is compatible with existing micro chips for capillary electrophoresis. Based upon the mathematical model, simulation study of micro pump was carried out to investigate the influence of structural parameters on flow characteristics, and the performance of the integrated micro pump was also tested with different control parameters. The simulation results agree with the experimental results. Three samples, which are amino acid, fluorescein and buffer solution, have been examined with this chip. The results of the primary experiments showed that the micro valveless pump was promising in the integration and automatization of miniature integrated fluidic systems.

  4. Investigation on the micro injection molding process of an overmolded multi-material micro component

    DEFF Research Database (Denmark)

    Baruffi, Federico; Calaon, Matteo; Tosello, Guido

    2017-01-01

    Micro injection molding (μIM) is one of the few technologies capable of meeting the increasing demand of complex shaped micro plastic parts. This process, combined with the overmolding technique, allows a fast and cost-efficient production of multi-material micro components, saving numerous...... and difficult assembly steps, being the plastic molded directly on a metal substrate. In this scenario, an investigation on the fully automated micro overmolding manufacturing technology of a three-material micro component for acoustic applications has been carried out. Preliminary experiments allowed...... geometrical characteristics of the component. An optical CMM with sub-micrometric resolution has been employed for the measurements. Results show that the process parameters have a significant influence on some component features, while others mainly depend on the insert alignment inside the micro mold cavity....

  5. Challenges in high accuracy surface replication for micro optics and micro fluidics manufacture

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Calaon, Matteo;

    2014-01-01

    by replication technologies such as nickel electroplating. All replication steps are enabled by a high precision master and high reproduction fidelity to ensure that the functionalities associated with the design are transferred to the final component. Engineered surface micro structures can be either......Patterning the surface of polymer components with microstructured geometries is employed in optical and microfluidic applications. Mass fabrication of polymer micro structured products is enabled by replication technologies such as injection moulding. Micro structured tools are also produced...... distributed, e.g., to create an optical pattern, or discretised, e.g., as micro channels for fluids manipulation. Key aspects of two process chains based on replication technologies for both types of micro structures are investigated: lateral replication fidelity, dimensional control at micro scale, edge...

  6. Microenvironment Tracker (MicroTrac) Factsheet

    Science.gov (United States)

    MicroTrac is a model developed by EPA that uses GPS data to estimate time of day and duration that people spend in different microenvironments, such as indoors and outdoors at home, work, school, and inside vehicles.

  7. EO Scanned Micro-LADAR Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this phase II SBIR we will design, build, test, and deliver new scanning based micro-ladar sensors with unprecedented small size, weight, and power (SWaP),...

  8. Evaluation of the micro-carburetor

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, M.F.; Hall, R.A.; Mazor, S.D.

    1981-08-01

    A prototype sonic, variable-venturi automotive carburetor, developed by Micro Carburetor Corporation, was evaluated for its effects on vehicle performance, fuel economy, and exhaust emissions. A 350 CID Chevrolet Impala vehicle was tested on a chassis dynamometer over the 1975 Federal Test Procedure, urban driving cycle. The Micro-carburetor was tested and compared with stock and modified-stock engine configurations. Subsequently, the test vehicle's performance characteristics were examined with the stock carburetor and again with the Micro-carburetor in a series of on-road driveability tests. The test engine was then removed from the vehicle and installed on an engine dynamometer. Engine tests were conducted to compare the fuel economy, thermal efficiency, and cylinder-to-cylinder mixture distribution of the Micro-carburetor to that of the stock configuration. Test results show increases in thermal efficiency and improvements in fuel economy at all test conditions.

  9. Micro Learning: A Modernized Education System

    Directory of Open Access Journals (Sweden)

    Omer Jomah

    2016-03-01

    Full Text Available Learning is an understanding of how the human brain is wired to learning rather than to an approach or a system. It is one of the best and most frequent approaches for the 21st century learners. Micro learning is more interesting due to its way of teaching and learning the content in a small, very specific burst. Here the learners decide what and when to learn. Content, time, curriculum, form, process, mediality, and learning type are the dimensions of micro learning. Our paper will discuss about micro learning and about the micro-content management system. The study will reflect the views of different users, and will analyze the collected data. Finally, it will be concluded with its pros and cons. 

  10. EO Scanned Micro-LADAR Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this SBIR program we will develop, design and build new scanning based micro-ladar sensors with unprecedented small size, weight, and power (SWaP), thereby...

  11. Micro Resistojet for Small Satellites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Micro-resistojets offer the best combination of simplicity, performance, wet system mass and power consumption for small satellites (<100kg, <50Watts)...

  12. Micro Resistojet for Small Satellites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Micro-resistojets offer an excellent combination of simplicity, performance and wet system mass for small satellites (<100 kg, <50 watts) requiring mN level...

  13. GEOMETRICAL CHARACTERIZATION OF MICRO END MILLING TOOLS

    DEFF Research Database (Denmark)

    Borsetto, Francesca; Bariani, Paolo

    for the manufacturing of miniature parts by micro milling puts further challenges on to the manufacturing process. The whole geometry of the tools cannot be directly downscaled with the tool diameter. Besides the physical limit in the reduction of the cutting edge radius constituted by the grain size of sintered...... carbides the error motion during the grinding wheels do not allow using identical paths for tools having differences in diameter of more than one order of magnitude. Thus grinding paths for micro and mills are simplified in comparison to those for larger tools of similar shape. [1] The aim of the present...... report is to develop procedures for the geometrical characterization of micro end milling tools in order to define a method suitable for the quality assurance in the micro cutting field....

  14. Characterization system for resonant micro- and nanocantilevers

    DEFF Research Database (Denmark)

    Sandberg, Rasmus Kousholt; Boisen, Anja; Svendsen, Winnie Edith

    2005-01-01

    We present a system for characterization of the resonant properties of micro- and nanocantilever sensors. The system has been constructed as a vacuum chamber with capabilities for controlling environmental conditions such as pressure, temperature, and chemical constituents. Characterization can...

  15. Laser micro-impulse torsion pendulum

    Institute of Scientific and Technical Information of China (English)

    Jing Li; Zhiping Tang

    2005-01-01

    @@ In order to investigate the feasibility regarding micro-satellite posture steering by laser micro-propulsion, a laser torsion pendulum has been set up so as to get first-hand basic physical and mechanical parameters on laser micro-propulsion. The instrumentation consists of the optical, mechanical, and electrical sub-systems.The optical system includes the main beam optics, the measuring optics, and the observation optics. The mechanical system includes the gyration apparatus, transverse translation stage, vertical translator, focal lenses translator, calibration pendulum translator, and vacuum chamber. For the electrical system a computer is used to control stepping motors to drive the above moving apparatuses. With this instrument the calibration experiment and laser ablation experiment have been carried out. The experimental results about 10.4%, which can satisfy the requirement of micro-impulse measurement.

  16. High range resolution micro-Doppler analysis

    Science.gov (United States)

    Cammenga, Zachary A.; Smith, Graeme E.; Baker, Christopher J.

    2015-05-01

    This paper addresses use of the micro-Doppler effect and the use of high range-resolution profiles to observe complex targets in complex target scenes. The combination of micro-Doppler and high range-resolution provides the ability to separate the motion of complex targets from one another. This ability leads to the differentiation of targets based on their micro-Doppler signatures. Without the high-range resolution, this would not be possible because the individual signatures would not be separable. This paper also addresses the use of the micro-Doppler information and high range-resolution profiles to generate an approximation of the scattering properties of a complex target. This approximation gives insight into the structure of the complex target and, critically, is created without using a pre-determined target model.

  17. Small Antennas for Wireless Micro-Systems

    OpenAIRE

    Rainer Wansch

    2002-01-01

    This paper will describe the topology of wireless micro-systems networks and some of their key components. In particular we will deal with the antennas: loops, helices, F-antennas, patches and dielectrically loaded antennas.

  18. Micro Learning: A Modernized Education System

    Directory of Open Access Journals (Sweden)

    Omer Jomah

    2016-03-01

    Full Text Available Learning is an understanding of how the human brain is wired to learning rather than to an approach or a system. It is one of the best and most frequent approaches for the 21st century learners. Micro learning is more interesting due to its way of teaching and learning the content in a small, very specific burst. Here the learners decide what and when to learn. Content, time, curriculum, form, process, mediality, and learning type are the dimensions of micro learning. Our paper will discuss about micro learning and about the micro-content management system. The study will reflect the views of different users, and will analyze the collected data. Finally, it will be concluded with its pros and cons. 

  19. Micro-polymer Chemistry Experiment Teaching Research

    Institute of Scientific and Technical Information of China (English)

    李青山

    2009-01-01

    For nearly thirty years,there has been made great progress in micro-polymer chemistry experiment teaching which has these characteristics that using less reagents,less pollution and more portable in comparison with the conventional experiment.In China,Zhou Ninghuai and others began to go on micro-scale experiment research firstly and Professor Li Qingshan who brought this innovation to polymer organic synthesis experiment has done a lot of works in micro-polymer chemistry experiment teaching.To carry out the study ofmicro-polymer chemistry experiments not only accords with teaching methods and reform,but also conforms to the trend of the times of green chemistry.So the research and application of micro-polymer chemistry experiment have broad prospects.

  20. Passive ring resonator micro-optical gyroscopes

    Science.gov (United States)

    Venediktov, V. Yu; Filatov, Yu V.; Shalymov, E. V.

    2016-05-01

    This paper reviews recent advances in passive micro-optical gyroscopes. In the last decade, most research effort in the area of micro-optical gyros has been concentrated on a configuration that takes advantage of a single-mode passive ring resonator, which is usually fabricated using integrated optical technologies. The dimensions of such micro-optical gyros are comparable to those of micromechanical gyroscopes (area of 10 to 100 mm2) and their sensitivity is considerably better than the sensitivity of the latter, approaching that of fibre-optic and laser gyros. Moreover, microoptical gyros can be made as a single integrated circuit, like the micromechanical gyros, but they have no movable parts, in contrast to their micromechanical counterparts. We also describe the development and investigation of micro-optical gyros produced in our studies.

  1. Simple Signal Source based Micro Controller

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Using micro controller, DAC and Multi-periods syn-thesis, we can buildup a very simple signal source with precisefrequency, amplitude and waveform. Wave parameters can beprogrammed in advance. The circuit can satisfy some special re-quirements.

  2. Micro Mercury Ion Clock (MMIC) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Demonstrate micro clock based on trapped Hg ions with more than 10x size reduction and power; Fractional frequency stability at parts per 1014 level, adequate for...

  3. MicroCar 2003. Abstracts of papers

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    Mechatronics for automotive applications is an important trend, combining mechanics, electronics and information technology. Micro- and nanomechatronics, particularly innovative research disciplines, will help create, in combination with advanced solutions from microsystem technologies, e.g. the electronic packaging, a range of entirely new developments in automobiles. Under the umbrella of the Automotive Suppliers Fair Z2003, it is happening for the very first time now that a momentous scientific conference, such as the MicroCar 2003, brings together representatives from car manufacturers and the electronics industry, as well as a large number of experts from technical colleges, universities and research institutes to discuss the new potentials and possibilities presented by the use of micro and nanomaterials in Leipzig. With the presentation of 50 papers, speakers will inform about their latest research results as well as current trends in micro and nanotechnologies for automotives. This issue is publishing the abstracts of this scientific event.

  4. Fabrication of micro-lens array on convex surface by meaning of micro-milling

    Science.gov (United States)

    Zhang, Peng; Du, Yunlong; Wang, Bo; Shan, Debin

    2014-08-01

    In order to develop the application of the micro-milling technology, and to fabricate ultra-precision optical surface with complex microstructure, in this paper, the primary experimental research on micro-milling complex microstructure array is carried out. A complex microstructure array surface with vary parameters is designed, and the mathematic model of the surface is set up and simulated. For the fabrication of the designed microstructure array surface, a micro three-axis ultra-precision milling machine tool is developed, aerostatic guideway drove directly by linear motor is adopted in order to guarantee the enough stiffness of the machine, and novel numerical control strategy with linear encoders of 5nm resolution used as the feedback of the control system is employed to ensure the extremely high motion control accuracy. With the help of CAD/CAM technology, convex micro lens array on convex spherical surface with different scales on material of polyvinyl chloride (PVC) and pure copper is fabricated using micro tungsten carbide ball end milling tool based on the ultra-precision micro-milling machine. Excellent nanometer-level micro-movement performance of the axis is proved by motion control experiment. The fabrication is nearly as the same as the design, the characteristic scale of the microstructure is less than 200μm and the accuracy is better than 1μm. It prove that ultra-precision micro-milling technology based on micro ultra-precision machine tool is a suitable and optional method for micro manufacture of microstructure array surface on different kinds of materials, and with the development of micro milling cutter, ultraprecision micro-milling complex microstructure surface will be achieved in future.

  5. Concept Studies of Micro-Pump for Chemical Concentration in Handheld Micro Sensors

    Science.gov (United States)

    2007-11-02

    This report summarizes the preliminary results of a short-term innovative research project on the concept study of micro pumps for chemical...main objective of the work is to study the feasibility of certain micro pumping concepts and their potential integration with the sensing material and... micro pumps is demonstrated, although the quantitative assessment of the pumping system is still elusive, partly because of lack of specifications. The

  6. Micro Loudspeaker Behaviour versus 6½" Driver, Micro Loudspeaker Parameter Drift

    DEFF Research Database (Denmark)

    Pedersen, Bo Rohde

    2010-01-01

    This study tested micro loudspeaker behavior from the perspective of loudspeaker parameter drift. The main difference between traditional transducers and micro loudspeakers, apart from their size, is their suspension construction. The suspension generally is a loudspeaker's most unstable parameter......, and the study investigated temperature drift and signal dependency. There is investigated three different micro loudspeakers and compared their behavior to that of a typical bass mid-range loudspeaker unit. There is measured all linear loudspeaker parameters at different temperatures....

  7. Micro Loudspeaker Behaviour versus 6½" Driver, Micro Loudspeaker Parameter Drift

    DEFF Research Database (Denmark)

    Pedersen, Bo Rohde

    2010-01-01

    This study tested micro loudspeaker behavior from the perspective of loudspeaker parameter drift. The main difference between traditional transducers and micro loudspeakers, apart from their size, is their suspension construction. The suspension generally is a loudspeaker's most unstable parameter......, and the study investigated temperature drift and signal dependency. There is investigated three different micro loudspeakers and compared their behavior to that of a typical bass mid-range loudspeaker unit. There is measured all linear loudspeaker parameters at different temperatures....

  8. Micro Electro Mechanical Systems (MEMS) Micro-Switches for Use in DC, RF, and Optical Applications

    Science.gov (United States)

    Suzuki, Kenichiro

    2002-06-01

    Micromachined micro-switches have stimulated the development of the core infrastructure technology for the next generation communication systems because of their superior performance. They are fabricated by similar silicon micromachined processes, but the switch structure and its characteristics depend on each application. Micro electro mechanical systems (MEMS) technology has been applied to micro relays, RF switches, and optical switches; as a result, optical and mechanical performance has been improved.

  9. microRNA研究进展%Progresses on the microRNA study

    Institute of Scientific and Technical Information of China (English)

    华友佳; 肖华胜

    2005-01-01

    小分子RNA家族中的一员--microRNA,是一段非常短的非编码RNA序列,对多种生物学过程起调控作用.本文试从microRNA的结构特点、合成及作用机制和功能等方面对microRNA的研究进展作一个简单回顾.

  10. MicroEnterprise Americas: Premiere Issue, 2001

    OpenAIRE

    Inter-American Development Bank (IDB)

    2001-01-01

    This premiere issue of MicroEnterprise Americas concentrates on the microfinance industry, a thriving segment of the Latin American financial sector that has rapidly expanded in the past five years. This issue explores looks at how market leaders have developed technologies, attracted investments, and developed tools for mitigating risk in the difficult financial climate of the past two years. MicroEnterprise Americas is published by the Inter-American Forum on Microenterprise, an annual even...

  11. Alkaliphilic Micro-organisms and Habitats

    OpenAIRE

    Ulukanli, Zeynep

    2002-01-01

    Alkaline environments are typical extreme environments which include naturally occurring soda lakes, deserts, soils and artificially occurring industrial-derived waters. Micro-organisms that occupy extreme pH environments have resulted in the definition of an unusual group, termed alkaliphiles. In this review, the current status of the biodiversity of alkaliphilic micro-organisms in various environments and aspects of their biotechnological potential are summarised briefly.

  12. MicroEnterprise Americas: Premiere Issue, 2001

    OpenAIRE

    Inter-American Development Bank (IDB)

    2001-01-01

    This premiere issue of MicroEnterprise Americas concentrates on the microfinance industry, a thriving segment of the Latin American financial sector that has rapidly expanded in the past five years. This issue explores looks at how market leaders have developed technologies, attracted investments, and developed tools for mitigating risk in the difficult financial climate of the past two years. MicroEnterprise Americas is published by the Inter-American Forum on Microenterprise, an annual even...

  13. Method for obtaining solid micro -or nanoparticles

    OpenAIRE

    Ventosa Rull, Nora; Veciana Miró, Jaume; Cano-Sarabia, Mary; Sala Vergés, Santiago

    2008-01-01

    [EN] The invention provides a novel method for obtaining solid micro -or nanoparticIes with a homogeneous structure. A method is provided for obtaining solid micro -or nanoparticIes with a homogeneous structure having a particIe size of less than 10 /lm where the processed solid compound has the natural, crystalline, amorphous, polymorphic and other features associated with the starting compound. In accordance with the invention a method which also makes it possible to obtain solid m...

  14. Embedded Operating System for MicroBlaze

    OpenAIRE

    2006-01-01

    This paper presents a work in progress on experiments with embedded operating systems for the MicroBlaze processor. Modern embedded systems based on a configurable platform incorporating a similar processor core are gaining importance with the ongoing effort to minimize cost and development time. After an overview of the configurable platform based on this processor core, we devote our attention to uClinux OS. This OS has been successfully ported for the MicroBlaze processor, and we present o...

  15. Micro PEM Fuel Cells and Stacks

    Institute of Scientific and Technical Information of China (English)

    Shou-shing; Hsieh

    2007-01-01

    1 Results The effects of different operating parameters on micro proton exchange membrane (PEM) fuel cell performance were experimentally studied for three different flow field configurations (interdigitated,mesh,and serpentine).Experiments with different cell operating temperatures and different backpressures on the H2 flow channels,as well as various combinations of these parameters,have been conducted for three different flow geometries.The micro PEM fuel cells were designed and fabricated in-house t...

  16. Experimental Research on Micro-nozzle Applied on Micro-propulsion Systems based on MEMS

    Science.gov (United States)

    Bao-jun, Zhang; Xing-chen, Li; Yi-yong, Huang; Xiang-ming, Xu

    2017-03-01

    In order to study the influence of the structural parameters of micro thruster applied in micro satellite attitude adjustment and orbital maneuver on its propulsion performance, this paper considers the factors influencing the performance of the thruster, and utilizes the orthogonal test design to obtain nine groups of micro-nozzles with different structural parameters. We processed this series of micro nozzles through MEMS (Micro-Electro-Mechanical Systems) technology. The micro-nozzles are made of single crystal silicon and glass through the anode bonding, and the electric heating wire is creatively processed through MEMS in the thrust chamber to improve the performance of the micro thruster. Experiments were carried out in a vacuum chamber. Finally, we analyse the experimental results by analysis of variance and analysis of range. The experimental results show that the performance of the micro nozzle is optimal when the semi-shrinking angle is 30 degrees, the semi-expansion angle is 15 degrees and the area ratio is 6.22. Meantime, the experiment verifies that it is feasible to improve the propulsive performance of micro-propulsion system through electronic heater strip.

  17. Analysis of bistable inductive micro-switch based on surface micro size effect

    Science.gov (United States)

    Tian, Wenchao; Chen, Zhiqiang

    2015-04-01

    The inductive micro-switch can not only induce an external acceleration, but also be controlled by the external acceleration to realize a trigger action. It is an integrative device of a sensor and an actuator. However, little work has been done to develop a comprehensive model to accurately analyze the micro size effect during micro-switch contact process. So its malfunctions related to "fail-to-closure" and "transient-closure" result in low reliability and weak anti-jamming capability. A bistable inductive micro-switch is presented based on nano electro-mechanical system (NEMS) technology and micro size effect. And the sine-model is used to describe the rough contact surface of the micro-switch. Micro size forces such as the Casimir force and van der Waals (vdW) force are analyzed in detail using the principles of vacuum energy and the Wigner-Seitz micro-continuum media. The vdW force includes the repulsive force. The simulation results of the Casimir force varied with the gap are obtained, which is compared with the relative experimental result. The dynamic equation of the bistable inductive micro-switch is established. Dynamic simulation results are shown to be in agreement with experimental results. The threshold acceleration is 6.8 g, and the response time is 17.5 μs.

  18. Micro powder injection molding-large scale production technology for micro-sized components

    Institute of Scientific and Technical Information of China (English)

    YIN HaiQing; JIA ChengChang; QU XuanHui

    2008-01-01

    Micro powder injection molding (μPIM), a miniaturized variant of powder injection molding, has advantages of shape complexity, applicability to many materials and good mechanical properties. Co-injection molding has been realized between metals and ceramics on micro components, which become the first breakthrough within the PIM field. Combined with the prominent characteristics of high features/cost ratio, micro powder injection molding becomes a potential technique for large scale production of intricate and three-dimensional micro components or microstructured components in microsystems technology (MST) field.

  19. microRNA与肿瘤转移%MicroRNAs and neoplasm metastasis

    Institute of Scientific and Technical Information of China (English)

    田伊茗; 王爽; 丁彦青

    2009-01-01

    MicroRNA,known as micro-RNA or miRNA,is a cluster of endogenous non-coding small RNAs regulating protein-coding mRNAs at the post-transcriptional level. More and more studies confirm the important role of microRNA in tumor metastasis,and the research of tumor metastasis-related microRNA has be-come the focus of attention. MicroRNAs may bring breakthroughs on diagnosis and treatment of tumor metasta-sis.%微RNA(microRNA)又称微小RNA、miRNA,是在转录后水平对编码蛋白质的mRNA进行调控的一族内源性非编码小RNA.越来越多的研究结果证实microRNA在肿瘤转移过程中发挥重要作用,肿瘤转移相关microRNA的研究已成为关注的热点.microRNA可能给肿瘤转移的诊断与治疗带来新的突破.

  20. Advances in MicroRNAs Research%MicroRNAs研究进展

    Institute of Scientific and Technical Information of China (English)

    丁伟超; 陈永康; 王莹

    2012-01-01

    MicroRNAs(miRNAs) are small regulator.noncoding RNA molecules that are transcribed as primary microR-NAs (pri-microRNAs) from eukaryotic genomes,prokaryotic genomes and virus,involved in post-transcriptional and transla-tional control of gene expression,either via degradation or translational inhibition of target mRNAs. These microRNAs play central roles in a wide range of biological processes,including cell proliferation,differentiation and apoptosis. This review has outlined the characteristics,process of maturation,mechanism of action and their function.%MicroRNAs简称miRNAs(微小RNAs),是真核生物、原核生物以及病毒中由非编码蛋白基因转录成的初级前体microRNAs加工成的调控因子.在转录后水平和蛋白质翻译水平,microRNAs通过降解或翻译抑制调控靶mRNA.这些microRNAs在广泛的生物过程中发挥重要作用,包括细胞增殖,分化和凋亡.主要介绍microR-NAs的特征,加工与成熟过程,作用机制以及其功能.

  1. Modulation of microRNA activity by semi-microRNAs (smiRNAs

    Directory of Open Access Journals (Sweden)

    Isabelle ePlante

    2012-06-01

    Full Text Available The ribonuclease Dicer plays a central role in the microRNA pathway by catalyzing the formation of 19 to 24-nucleotide (nt long microRNAs. Subsequently incorporated into Ago2 effector complexes, microRNAs are known to regulate messenger RNA (mRNA translation. Whether shorter RNA species derived from microRNAs exist and play a role in mRNA regulation remains unknown. Here, we report the serendipitous discovery of a 12-nt long RNA species corresponding to the 5’ region of the microRNA let-7, and tentatively termed semi-microRNA, or smiRNA. Using a smiRNA derived from the precursor of miR-223 as a model, we show that 12-nt long smiRNA species are devoid of any direct mRNA regulatory activity, as assessed in a reporter gene activity assay in transfected cultured human cells. However, smiR-223 was found to modulate the ability of the microRNA from which it derives to mediate translational repression or cleavage of reporter mRNAs. Our findings suggest that smiRNAs may be generated along the microRNA pathway and participate to the control of gene expression by regulating the activity of the related full-length mature microRNA in vivo.

  2. MicroRNA Regulation in Renal Pathophysiology

    Directory of Open Access Journals (Sweden)

    Jianghui Hou

    2013-06-01

    Full Text Available MicroRNAs are small, noncoding RNA molecules that regulate a considerable amount of human genes on the post-transcriptional level, and participate in many key biological processes. MicroRNA deregulation has been found associated with major kidney diseases. Here, we summarize current knowledge on the role of microRNAs in renal glomerular and tubular pathologies, with emphasis on the mesangial cell and podocyte dysfunction in diabetic nephropathy, the proximal tubular cell survival in acute kidney injury, the transport function of the thick ascending limb in Ca++ imbalance diseases, and the regulation of salt, K+ and blood pressure in the distal tubules. Identification of microRNAs and their target genes provides novel therapeutic candidates for treating these diseases. Manipulation of microRNA function with its sense or antisense oligonucleotide enables coordinated regulation of the entire downstream gene network, which has effectively ameliorated several renal disease phenotypes. The therapeutic potentials of microRNA based treatments, though promising, are confounded by major safety issues related to its target specificity, which remain to be fully elucidated.

  3. Micro-Ramps for Hypersonic Flow Control

    Directory of Open Access Journals (Sweden)

    Konstantinos Kontis

    2012-04-01

    Full Text Available Shock/boundary layer interaction (SBLI is an undesirable phenomenon, occurring in high-speed propulsion systems. The conventional method to manipulate and control SBLI is using a bleed system that involves the removal of a certain amount of mass of the inlet flow to control boundary layer separation. However, the system requires a larger nacelle to compensate the mass loss, larger nacelles contribute to additional weight and drag and reduce the overall performance. This study investigates a novel type of flow control device called micro-ramps, a part of the micro vortex generators (VGs family that intends to replace the bleed technique. Micro-ramps produce pairs of counter-rotating streamwise vortices, which help to suppress SBLI and reduce the chances of flow separation. Experiments were done at Mach 5 with two micro-ramp models of different sizes. Schlieren photography, surface flow visualization and infrared thermography were used in this investigation. The results revealed the detailed flow characteristics of the micro-ramp, such as the primary and secondary vortices. This helps us to understand the overall flow physics of micro-ramps in hypersonic flow and their application for SBLI control.

  4. Laser 3D micro-manufacturing

    Science.gov (United States)

    Piqué, Alberto; Auyeung, Raymond C. Y.; Kim, Heungsoo; Charipar, Nicholas A.; Mathews, Scott A.

    2016-06-01

    Laser-based materials processing techniques are gaining widespread use in micro-manufacturing applications. The use of laser microfabrication techniques enables the processing of micro- and nanostructures from a wide range of materials and geometries without the need for masking and etching steps commonly associated with photolithography. This review aims to describe the broad applications space covered by laser-based micro- and nanoprocessing techniques and the benefits offered by the use of lasers in micro-manufacturing processes. Given their non-lithographic nature, these processes are also referred to as laser direct-write and constitute some of the earliest demonstrations of 3D printing or additive manufacturing at the microscale. As this review will show, the use of lasers enables precise control of the various types of processing steps—from subtractive to additive—over a wide range of scales with an extensive materials palette. Overall, laser-based direct-write techniques offer multiple modes of operation including the removal (via ablative processes) and addition (via photopolymerization or printing) of most classes of materials using the same equipment in many cases. The versatility provided by these multi-function, multi-material and multi-scale laser micro-manufacturing processes cannot be matched by photolithography nor with other direct-write microfabrication techniques and offer unique opportunities for current and future 3D micro-manufacturing applications.

  5. Homogenization in micro-magneto-mechanics

    Science.gov (United States)

    Sridhar, A.; Keip, M.-A.; Miehe, C.

    2016-07-01

    Ferromagnetic materials are characterized by a heterogeneous micro-structure that can be altered by external magnetic and mechanical stimuli. The understanding and the description of the micro-structure evolution is of particular importance for the design and the analysis of smart materials with magneto-mechanical coupling. The macroscopic response of the material results from complex magneto-mechanical interactions occurring on smaller length scales, which are driven by magnetization reorientation and associated magnetic domain wall motions. The aim of this work is to directly base the description of the macroscopic magneto-mechanical material behavior on the micro-magnetic domain evolution. This will be realized by the incorporation of a ferromagnetic phase-field formulation into a macroscopic Boltzmann continuum by the use of computational homogenization. The transition conditions between the two scales are obtained via rigorous exploitation of rate-type and incremental variational principles, which incorporate an extended version of the classical Hill-Mandel macro-homogeneity condition covering the phase field on the micro-scale. An efficient two-scale computational scenario is developed based on an operator splitting scheme that includes a predictor for the magnetization on the micro-scale. Two- and three-dimensional numerical simulations demonstrate the performance of the method. They investigate micro-magnetic domain evolution driven by macroscopic fields as well as the associated overall hysteretic response of ferromagnetic solids.

  6. Advanced Micro Turbine System (AMTS) -C200 Micro Turbine -Ultra-Low Emissions Micro Turbine

    Energy Technology Data Exchange (ETDEWEB)

    Capstone Turbine Corporation

    2007-12-31

    In September 2000 Capstone Turbine Corporation commenced work on a US Department of Energy contract to develop and improve advanced microturbines for power generation with high electrical efficiency and reduced pollutants. The Advanced MicroTurbine System (AMTS) program focused on: (1) The development and implementation of technology for a 200 kWe scale high efficiency microturbine system (2) The development and implementation of a 65 kWe microturbine which meets California Air Resources Board (CARB) emissions standards effective in 2007. Both of these objectives were achieved in the course of the AMTS program. At its conclusion prototype C200 Microturbines had been designed, assembled and successfully completed field demonstration. C65 Microturbines operating on natural, digester and landfill gas were also developed and successfully tested to demonstrate compliance with CARB 2007 Fossil Fuel Emissions Standards for NOx, CO and VOC emissions. The C65 Microturbine subsequently received approval from CARB under Executive Order DG-018 and was approved for sale in California. The United Technologies Research Center worked in parallel to successfully execute a RD&D program to demonstrate the viability of a low emissions AMS which integrated a high-performing microturbine with Organic Rankine Cycle systems. These results are documented in AMS Final Report DOE/CH/11060-1 dated March 26, 2007.

  7. Micro-Doppler classification of riders and riderless horses

    Science.gov (United States)

    Tahmoush, David

    2014-05-01

    Micro-range Micro-Doppler can be used to isolate particular parts of the radar signature, and in this case we demonstrate the differences in the signature between a walking horse versus a walking horse with a rider. Using micro-range micro-Doppler, we can distinguish the radar returns from the rider as separate from the radar returns of the horse.

  8. Development of Compressor for Ultra Micro Gas Turbine

    Institute of Scientific and Technical Information of China (English)

    Shimpei MIZUKI

    2007-01-01

    The major problems for the development of an ultra micro gas turbine system were discussed briefly from the stand point of the internal flow and the performance characteristics. Following to these, the development of ultra micro centrifugal compression systems for the ultra micro gas turbine is explained with the design and the manufacturing processes. The measured results of ultra micro centrifugal compressors are shown.

  9. Micro mechanical study of shales

    Science.gov (United States)

    Bonnelye, Audrey; Picard, David; Gharbi, Hakim; Dimanov, Alexandre; Bornert, Michel; Conil, Nathalie

    2017-04-01

    In the following years, the French nuclear wastes will be buried in the underground repository in shales, that will be excavated at 490 m in depth, within the Callovo Oxfordian (Cox) argillaceous formation. The hydro-mechanical behavior of the argillaceous rock is complex, like the multiphase and multi-scale structured material itself. The argilaceous matrix is composed of interstratified Illite-Smectite particles, it contains detritic quartz and calcite, accessory pyrite, and the rock porosity ranges from micrometre to nanometre scales. Besides the bedding anisotropy, structural variabilities exist at all scales, from the decametric-metric scales of the geological formation to the respectively millimetric and micrometric scales of the aggregates of particles and clay particles Our study aims at understanding the complex mechanisms which are activated at the micro-scale and are involved in the macroscopic inelastic deformation of such a complex material.An experimental protocol was developed in order to perform uniaxial deformation experiment at controlled displacement rate, inside an environmental scanning electron microscope (ESEM), under controlled relative humidity, in order to preserve as much as possible the natural state of saturation of shales. Three sample orientations (90°, 45° and 0°) were used in order to characterize the mechanical anisotropy and the mechanisms involved in the deformation. The observed smple surfaces were polished by broad ion beam in order to reveal the fine microstructures of the argillaceous matrix. Digital images were acquired at different loading stages during the deformation process and Digital Image Correlation Technique (DIC) was applied in order to retrieve full strain fields at various scales from sample scale to microstructure scale. The analysis allows for identification of the active mechanisms, their relationships to the microstructure and their interactions.

  10. Intraoral micro-identification discs.

    Science.gov (United States)

    Hansen, R W

    1991-12-01

    Intraoral micro-identification discs have recently been utilized to provide a more permanent method of personal identification. A wafer of plastic or metal with a surface area of 2.5 to 5 mm2 and carrying identifying numbers and/or letters (indicia) is bonded to the buccal enamel surface of the posterior teeth. Personal identification can occur after the I.D. disc is identified and the indicia is read. Reading of photoreduced indicia requires the aid of a microscope subsequent to the removal of the microdisc. In situ reading of disc indicia is possible using low power handheld magnifiers if the size of the indicia approximates 0.3 mm. Computerization is an integral part of non-custom alpha/numeric type designs, but a custom disc carries a name, address, and other specific information unique to the manufacturer. The use of a computer improves access to the database and it decreases the amount of data placed on the disc. Microdisc bases may be fabricated using a mylar type plastic or they may be manufactured from a stainless steel blank. Plastic discs are constructed with an internal sandwich containing the photo-reduced indicia. Metal discs are marked with a photochemical etch or engraved with a computer driven YAG laser. Attachment of the disc to the enamel surface is accomplished by conventional etching and bonding techniques and are typically bonded to the buccal surface of the maxillary first permanent molar or the second primary molar. Clear composite bonding material covers the disc so that salivary contamination does not result in degradation of the indicia. Orthodontic style discs with a mesh back carry laser written information that may be cemented with conventional orthodontic bonding cement. Standardization of the indicia and overall design is considered to be an important aspect of patient and professional acceptance.

  11. Micro-Layer Tomography System

    Directory of Open Access Journals (Sweden)

    M. Navabpour

    2005-08-01

    Full Text Available Introduction & Background: Tomography or plani-graphy is an x-ray imaging system for preserving a certain plane of a radiography object by diffusing the other planes; however, the desired plane does not obtain an optimum sharpness. Meanwhile, relatively nearer points to the rotating axes fixed point have lesser liner velocity than those lying further from the fixed point. Consequently, unwanted obscuring planes occur gradually, that then render the wanted plane somehow blurred, hence the phenomenon known as "tomographic blurring", which diminishes the clinical value of the image. Thus, computerized imaging is uncertain especially to medical authorities. Besides, there is a possibility of dismissing the lesion in some cases, because of the relatively undesirable deep resolution of the system. The present innovation could be an approach to improve current tomography systems by increasing image resolution, obtaining optimum deep resolution, rapid operation, and cost reduction. Material and Methods: Micro-layer tomography has been designed with the benefit of fast x-ray rotating velocity without tube movement, to make images with deep resolution of millimeter fraction, while there is no need of digital images reconstruction in-struments that allows statistical errors to fall to about zero. Furthermore, high-resolution images could be prepared in all planes, including coronal, sagittal, and transverse ones. Likewise, patient treatment and sys-tem maintenance costs are by far less than those in CT scan and MRI. Results & Conclusion: The system quick operation is highly exceptional; therefore, the tomographic slices could be prepared in about less than 0.02 second. The laboratory samples experienced by this system showed a unique result, suggesting the new device preference.

  12. MicroRNA与妇科肿瘤%MicroRNA and gynecological oncology

    Institute of Scientific and Technical Information of China (English)

    樊秦娥; 吴立兵

    2014-01-01

    小分子 RNA(microRNA)的发现是分子生物学史上的又一个里程碑。microRNA是一组单链非编码的RNA,由19~25个核苷酸(平均22个核苷酸)组成。研究证实microRNA在生理及病理状态下调节转录后的基因表达。其调节功能与细胞周期的调节,细胞增殖分化,炎症反应及凋亡相关。在许多病理状态下观察到 microRNA表达谱的改变,如糖尿病,类风湿性关节炎以及一些癌症。本综述对microRNA与妇科肿瘤的相关文献进行复习,总结microRNA在妇科肿瘤的发病机制中的可能作用,讨论microRNA作为妇科肿瘤早期诊断和治疗监控的肿瘤标记物的可能性,并对microRNAs在妇科肿瘤中作为治疗靶点和预后判断因素的可能性进行讨论。%The discovery of MicroRNA is another milestone in the history of molecular biology. MicroRNA is a group of single noncoding RNA that consists of 19-25 nucleotides (an average of 22 nucleotides). Study has verified that MicroRNA in physiological and pathological state regulates the transcription of gene expression. Its regulating function is related with regulation of cell cycle, cell proliferation differentiation, inflammation, and apoptosis. In many pathological conditions such as diabetes, rheumatoid arthritis and some cancers, MicroRNA expression changes. This abstract reviewed the pertinent literature of MicroRNA and gynecological tumor, summarized the possible role of MicroRNA in the pathogenesis of gynecological tumors, discussed the possibility of MicroRNA acting as tumor markers in early diagnosis and supervisory treatment and discussed the the possibility of MicroRNA acting as therapeutic targets and the prognostic factors in gynecological tumors .

  13. microPIR: an integrated database of microRNA target sites within human promoter sequences.

    Directory of Open Access Journals (Sweden)

    Jittima Piriyapongsa

    Full Text Available BACKGROUND: microRNAs are generally understood to regulate gene expression through binding to target sequences within 3'-UTRs of mRNAs. Therefore, computational prediction of target sites is usually restricted to these gene regions. Recent experimental studies though have suggested that microRNAs may alternatively modulate gene expression by interacting with promoters. A database of potential microRNA target sites in promoters would stimulate research in this field leading to more understanding of complex microRNA regulatory mechanism. METHODOLOGY: We developed a database hosting predicted microRNA target sites located within human promoter sequences and their associated genomic features, called microPIR (microRNA-Promoter Interaction Resource. microRNA seed sequences were used to identify perfect complementary matching sequences in the human promoters and the potential target sites were predicted using the RNAhybrid program. >15 million target sites were identified which are located within 5000 bp upstream of all human genes, on both sense and antisense strands. The experimentally confirmed argonaute (AGO binding sites and EST expression data including the sequence conservation across vertebrate species of each predicted target are presented for researchers to appraise the quality of predicted target sites. The microPIR database integrates various annotated genomic sequence databases, e.g. repetitive elements, transcription factor binding sites, CpG islands, and SNPs, offering users the facility to extensively explore relationships among target sites and other genomic features. Furthermore, functional information of target genes including gene ontologies, KEGG pathways, and OMIM associations are provided. The built-in genome browser of microPIR provides a comprehensive view of multidimensional genomic data. Finally, microPIR incorporates a PCR primer design module to facilitate experimental validation. CONCLUSIONS: The proposed micro

  14. Spatial inhomogeneity in spectra and exciton dynamics in porphyrin micro-rods and micro-brushes: Confocal microscopy

    Indian Academy of Sciences (India)

    SHYAMTANU CHATTORAJ; KANKAN BHATTACHARYYA

    2016-11-01

    In an aqueous acidic solution, the porphyrin meso-tetra(4-sulfonatophenyl) porphyrin tetrasodium salt (TPPS) forms different kinds of assembly (micro-rods and micro-brush) depending on condition of evaporation. The exciton dynamics and emission spectra of the micro-rods and micro-brushes depend on spatialinhomogeneity. This is elucidated by time-resolved confocal microscopy.

  15. Functional MicroRNA Involved in Endometriosis

    Science.gov (United States)

    Creighton, Chad J.; Han, Derek Y.; Zariff, Azam; Anderson, Matthew L.; Gunaratne, Preethi H.; Matzuk, Martin M.

    2011-01-01

    Endometriosis is a common disease seen by gynecologists. Clinical features involve pelvic pain and unexplained infertility. Although endometriosis is pathologically characterized by endometrial tissue outside the normal uterine location, endometriosis is otherwise not easily explained. Endometriomas, endometriotic cysts of the ovary, typically cause pain and distortion of pelvic anatomy. To begin to understand the pathogenesis of endometriomas, we describe the first transcriptome-microRNAome analysis of endometriomas and eutopic endometrium using next-generation sequencing technology. Using this approach, we generated a total of more than 54 million independent small RNA reads from our 19 clinical samples. At the microRNA level, we found 10 microRNA that were up-regulated (miR-202, 193a-3p, 29c, 708, 509-3-5p, 574-3p, 193a-5p, 485-3p, 100, and 720) and 12 microRNA that were down-regulated (miR-504, 141, 429, 203, 10a, 200b, 873, 200c, 200a, 449b, 375, and 34c-5p) in endometriomas compared with endometrium. Using in silico prediction algorithms, we correlated these microRNA with their corresponding differentially expressed mRNA targets. To validate the functional roles of microRNA, we manipulated levels of miR-29c in an in vitro system of primary cultures of human endometrial stromal fibroblasts. Extracellular matrix genes that were potential targets of miR-29c in silico were significantly down-regulated using this biological in vitro system. In vitro functional studies using luciferase reporter constructs further confirmed that miR-29c directly affects specific extracellular matrix genes that are dysregulated in endometriomas. Thus, miR-29c and other abnormally regulated microRNA appear to play important roles in the pathophysiology of uterine function and dysfunction. PMID:21436257

  16. MicroRNA与黑素瘤%MicroRNA and melanoma

    Institute of Scientific and Technical Information of China (English)

    于少硕; 苏铎

    2013-01-01

    MicroRNA(miRNA)是一种内源性非编码小RNA,在转录后水平负调节靶基因的表达,并参与多种细胞的生命活动,特别是在肿瘤的发生、发展和迁移过程中起重要作用.miRNA通过调控相关靶基因,影响黑素瘤相关蛋白的转录翻译,从而促进或抑制黑素瘤的发生、发展和转移.miR-137和miR-182可以负向调节小眼球相关转录因子(microphthalmia-associatedtranscription factor,MITF)表达,抑制黑素瘤增殖和侵袭;MITF也可以反向调控miR-137和miR-182,增强黑素瘤的迁移能力.miR-221和miR-222通过下调p27Kipl/CDKN1B和c-kit受体两条信号通路促进黑素细胞恶化,从而在黑素瘤中发挥癌基因样效应;而在早幼粒白血病锌指蛋白(promyelocytic leukemia Zinc-Finger,PLZF)结合miR-221和miR-222的调节区后,可以抑制黑素瘤细胞转化和侵袭.Let-7家族成员主要抑制黑素瘤发生、发展和迁移,一旦缺失或表达下降则促进黑素瘤增殖发展.miR-34通过下调原癌基因和相关细胞周期蛋白表达,在黑素瘤中主要发挥抑癌基因样作用.通过检测正常个体和黑素瘤患者外周血miRNA表达谱的差异,有助于诊断黑素瘤;监测分析相关miRNA变化有助于判断患者的疗效和预后情况.因此,深入探索相关miRNA在黑素瘤中的靶基因及调控作用机制有望为黑素瘤的诊断、治疗开辟新途径.

  17. Micro-Grooving and Micro-Threading Tools for Fabricating Curvilinear Features

    Energy Technology Data Exchange (ETDEWEB)

    ADAMS,DAVID P.; VASILE,MICHAEL J.; KRISHNAN,A.S.M.

    2000-07-24

    This paper presents techniques for fabricating microscopic, curvilinear features in a variety of workpiece materials. Micro-grooving and micro-threading tools having cutting widths as small as 13 {micro}m are made by focused ion beam sputtering and used for ultra-precision machining. Tool fabrication involves directing a 20 keV gallium beam at polished cylindrical punches made of cobalt M42 high-speed steel or C2 tungsten carbide to create a number of critically aligned facets. Sputtering produces rake facets of desired angle and cutting edges having radii of curvature equal to 0.4 {micro}m. Clearance for minimizing frictional drag of a tool results from a particular ion beam/target geometry that accounts for the sputter yield dependence on incidence angle. It is believed that geometrically specific cutting tools of this dimension have not been made previously. Numerically controlled, ultra-precision machining with micro-grooving tools results in a close match between tool width and feature size. Microtools are used to machine 13 {micro}m wide, 4 {micro}m deep, helical grooves in polymethyl methacrylate and 6061 Al cylindrical workplaces. Micro-grooving tools are also used to fabricate sinusoidal cross-section features in planar metal samples.

  18. Fabrication of Biochips with Micro Fluidic Channels by Micro End-milling and Powder Blasting

    Directory of Open Access Journals (Sweden)

    Dong Sam Park

    2008-02-01

    Full Text Available For microfabrications of biochips with micro fluidic channels, a large number of microfabrication techniques based on silicon or glass-based Micro-Electro-Mechanical System (MEMS technologies were proposed in the last decade. In recent years, for low cost and mass production, polymer-based microfabrication techniques by microinjection molding and micro hot embossing have been proposed. These techniques, which require a proper photoresist, mask, UV light exposure, developing, and electroplating as a preprocess, are considered to have some problems. In this study, we propose a new microfabrication technology which consists of micro end-milling and powder blasting. This technique could be directly applied to fabricate the metal mold without any preprocesses. The metal mold with micro-channels is machined by micro end-milling, and then, burrs generated in the end-milling process are removed by powder blasting. From the experimental results, micro end-milling combined with powder blasting could be applied effectively for fabrication of the injection mold of biochips with micro fluidic channels.

  19. MicroRNA in 2012: Biotherapeutic potential of microRNAs in rheumatic diseases.

    Science.gov (United States)

    Pers, Yves-Marie; Jorgensen, Christian

    2013-02-01

    A number of microRNAs have been implicated in the pathogenesis of various rheumatic diseases, and evidence in support of the therapeutic potential of microRNA-based strategies for these conditions is growing, as demonstrated by several new findings published in 2012.

  20. MicroRNA与心血管重构%MicroRNA and cardiovascular remodeling

    Institute of Scientific and Technical Information of China (English)

    邓璧

    2013-01-01

    MicroRNA is a short (18-25 nuucleotides) and single-stranded non-coding RNA which is involved in almost all pathological and physiological process of diseases.Cardiovascular remodeling is the pathological basis of development of multiple cardiovascular diseases,in which microRNA plays an important role.In cardiac diseases,microRNAs affect myocardial cell hypertrophy,apoptosis,and interstitial fibrosis through a variety of mechanisms.In vascular remodeling diseases,microRNAs regulate proliferation and secretion of vascular smooth muscle cells through multiple signaling pathways.%MicroRNA为短小(18~25个核苷酸组成)单链非编码RNAs,几乎参与所有疾病的病理生理过程.心血管重构是多种心血管疾病发生与发展的病理基础,而microRNA在心血管重构中起重要调控作用.在心肌性疾病中,microRNA通过多种机制影响心肌细胞肥大、凋亡和间质纤维化;在血管重构性疾病中,不同microRNA通过多条信号通路调节血管平滑肌细胞增殖和分泌.

  1. Micro Engineering: Experiments conducted on the use of polymeric materials in micro injection moulding

    DEFF Research Database (Denmark)

    Griffiths, Christian; Tosello, Guido; Nestler, Joerg

    2008-01-01

    To advance micro injection moulding it is necessary to study systematically the factors affecting process and tooling reliability. This paper reviews the main findings of Cardiff Universities 4M and SEMOFS research in this field. In particular, the factors affecting the manufacturability of micro...

  2. Concept of subsurface micro-sensing; Chika joho no micro sensing

    Energy Technology Data Exchange (ETDEWEB)

    Niitsuma, H. [Tohoku University, Sendai (Japan). Faculty of Engineering

    1997-05-27

    This paper describes concept of subsurface micro-sensing. It is intended to achieve an epoch-making development of subsurface engineerings by developing such technologies as micro measurement of well interior, micro measurement while drilling (MWD), and micro intelligent logging. These technologies are supported by development of micro sensors and micro drilling techniques using micro machine technologies. Micronizing the subsurface sensors makes mass production of sensors with equivalent performance possible, and the production cost can be reduced largely. The sensors can be embedded or used disposably, resulting in increased mobility in measurement and higher performance. Installing multiple number of sensors makes high-accuracy measurement possible, such as array measurement. The sensors can be linked easily with photo-electronics components, realizing remote measurement at low price and high accuracy. Control in micro-drilling and MWD also become possible. Such advantages may also be expected as installing the sensors on the outer side of wells in use and monitoring subsurface information during production. Expectation on them is large as a new paradigm of underground exploration and measurement. 1 fig.

  3. Role of microRNA in Lung Cancer%microRNA在肺癌中的作用

    Institute of Scientific and Technical Information of China (English)

    杨凡; 陈艳; 伍治平; 朱启顺

    2011-01-01

    microRNA是一类长约19~25个核苷酸的非编码小分子.研究表明microRNA 在肿瘤的病理生理过程中发挥着重要作用.全文就microRNA的特征、生物学功能、与 肺癌相关的microRNA及microRNA的检测方法等方面作一综述.

  4. Polymeric Micro-channel-based Functionalisation System for Micro-Cantilevers

    DEFF Research Database (Denmark)

    Nordström, Maria; Gomez, Montserrat; Boisen, Anja

    2005-01-01

    A micro-channel system intended for functionalising micro-cantilevers used for biochemical detection has been designed, realised and characterised. The chip is fabricated in the resist SU-8, which is a photosensitive polymer offering a fast, cost-efficient and easy processing. Cantilevers present...... a new platform for biochemical detection with a high sensitivity. This micro-channel system is used for treating such a cantilever array with probe molecules prior to detection and it can also be used as the analysis set-up. The design of the micro-channel system provides a simple way of coating...... separate sections of a cantilever array with different probe molecules. The use of this channel system eliminates the time-consuming step of addressing each cantilever individually to obtain an array functionalised with different probe molecules. Using this micro-channel system in combination...

  5. Fabrication of micro-alginate gel tubes utilizing micro-gelatin fibers

    Science.gov (United States)

    Sakaguchi, Katsuhisa; Arai, Takafumi; Shimizu, Tatsuya; Umezu, Shinjiro

    2017-05-01

    Tissues engineered utilizing biofabrication techniques have recently been the focus of much attention, because these bioengineered tissues have great potential to improve the quality of life of patients with various hard-to-treat diseases. Most tissues contain micro-tubular structures including blood vessels, lymphatic vessels, and bile canaliculus. Therefore, we bioengineered a micro diameter tube using alginate gel to coat the core gelatin gel. Micro-gelatin fibers were fabricated by the coacervation method and then coated with a very thin alginate gel layer by dipping. A micro diameter alginate tube was produced by dissolving the core gelatin gel. Consequently, these procedures led to the formation of micro-alginate gel tubes of various shapes and sizes. This biofabrication technique should contribute to tissue engineering research fields.

  6. A new micro scale FE model of crystalline materials in micro forming process

    Directory of Open Access Journals (Sweden)

    Luo Liang

    2016-01-01

    Full Text Available Micro forming of metals has drawn global attention due to the increasing requirement of micro metal products. However, the size effects become significant in micro forming processes and affect the application of finite element (FE simulation of micro forming processes. Dividing samples into small areas according to their microstructures and assigning individual properties to each small area are a possible access to micro forming simulation considering material size effects. In this study, a new model that includes both grains and their boundaries was developed based on the observed microstructures of samples. The divided subareas in the model have exact shapes and sizes with real crystals on the sample, and each grain and grain boundaries have their own properties. Moreover, two modelling methods using different information from the microstructural images were introduced in detail. The two modelling methods largely increase the availability of various microstructural images. The new model provides accurate results which present the size effects well.

  7. Micro Groove for Trapping of Flowing Cell

    Directory of Open Access Journals (Sweden)

    Yusuke Takahashi

    2015-06-01

    Full Text Available Micro grooves have been designed to trap a biological cell, which flows through a micro channel in vitro. Each micro groove of a rectangular shape (0.002 mm depth, 0.025 mm width and 0.2 mm length has been fabricated on the surface of the polydimethylsiloxane (PDMS disk with the photolithography technique. Variation has been made on the angle between the longitudinal direction of the groove and the flow direction: zero, 0.79, or 1.57 rad. A rectangular flow channel (0.1 mm depth x 5 mm width x 30 mm length has been constructed with a silicone film of 0.1 mm thick, which has been sandwiched by two transparent PDMS disks. Two types of biological cells were used in the test alternatively: C2C12 (mouse myoblast cell line originated with cross-striated muscle of C3H mouse, or 3T3-L1 (mouse fat precursor cells. A constant flow (2.8 x 10-11 m3/s of a suspension of cells was introduced with a syringe pump. The behavior of cells moving over the micro grooves was observed with an inverted phase contrast microscope. The results show that the cell is trapped with the micro grooves under the wall shear rate of 3 s-1 for a few seconds and that the trapped interval depends on the kind of cells.

  8. Micro-bubbles seeding for flow characterization

    Science.gov (United States)

    Aumelas, V.; Lecoffre, Y.; Maj, G.; Franc, J.-P.

    2016-11-01

    Micro-bubbles injection has long been used in hydrodynamic facilities for the control of dissolved and free air. In some cavitation tunnels [9], very large quantities of microbubbles (billions per second) are injected for rapid degassing and, in smaller quantities (millions per second), for cavitation nuclei seeding. Micro-bubbles can also be used as tracers for optical measurements including visualization, LDV or PIV. For these applications, bubbles must be sufficiently small to faithfully follow the flow. Depending on the quality and spatial characteristics of the micro-bubbles seeding, several optical methods can be applied: simple visualization gives access to semi-quantitative information on the behaviour of flows; LASER velocimetry provides information on the mean velocity and other temporal local characteristics of the flow. This paper presents some new micro-bubbles seeding devices recently developed by YLEC Consultants. These devices have been designed to fulfill specific requirements related to integration into cavitation tunnels and permit optical velocimetry measurement techniques such as Particle Image Velocimetry (PIV). The LEGI cavitation tunnel is the first tunnel which has been equipped with these microbubbles seeding systems dedicated to optical velocimetry. This paper presents the final integration schemes selected for micro-bubbles seeding into LEGI tunnel and discuss about practical concerns related to the use of the injection system for optical velocimetry.

  9. Wideband radar micro-doppler applications

    Science.gov (United States)

    Tahmoush, Dave

    2013-05-01

    Wideband radar provides a significant improvement over traditional narrowband radars for micro-Doppler analysis because the high bandwidth can be used to separate many of the signals in range, allowing a simpler decomposition of the micro-Doppler signals. Recent wideband radar work has focused on micro-Doppler, but there is a point where the narrowband approach used to analyze the micro-Doppler signals breaks down. The effect is shown to be independent of frequency, but the error relative to the bandwidth is shown to be inversely proportional to the frequency and proportional to the velocity of the subject. This error can create a smearing effect in the observed Doppler if it is not corrected, leading to reduced signal-to-noise and the appearance of more diffuse targets in Doppler space. In range-space, wideband data can also break the subject into several range bins, affecting the observed signal to noise ratio. The possible applications of wideband micro-Doppler radar are also shown, including the separation of arm movement from human motion which implies that the arms are not encumbered.

  10. Behavior of Cell on Vibrating Micro Ridges

    Directory of Open Access Journals (Sweden)

    Haruka Hino

    2015-06-01

    Full Text Available The effect of micro ridges on cells cultured at a vibrating scaffold has been studied in vitro. Several parallel lines of micro ridges have been made on a disk of transparent polydimethylsiloxane for a scaffold. To apply the vibration on the cultured cells, a piezoelectric element was attached on the outside surface of the bottom of the scaffold. The piezoelectric element was vibrated by the sinusoidal alternating voltage (Vp-p < 16 V at 1.0 MHz generated by a function generator. Four kinds of cells were used in the test: L929 (fibroblast connective tissue of C3H mouse, Hepa1-6 (mouse hepatoma, C2C12 (mouse myoblast, 3T3-L1 (mouse fat precursor cells. The cells were seeded on the micro pattern at the density of 2000 cells/cm2 in the medium containing 10% FBS (fetal bovine serum and 1% penicillin/ streptomycin. After the adhesion of cells in several hours, the cells are exposed to the ultrasonic vibration for several hours. The cells were observed with a phase contrast microscope. The experimental results show that the cells adhere, deform and migrate on the scaffold with micro patterns regardless of the ultrasonic vibration. The effects of the vibration and the micro pattern depend on the kind of cells.

  11. Advances in micro-perforated panel absorbers

    Institute of Scientific and Technical Information of China (English)

    LIU Ke; TIAN Jing; JIAO Fenglei; L(U) Yadong

    2006-01-01

    Theoretical and experimental investigations on the performance of micro-perforated-panel absorbers are reviewed in this paper. By reviewing recent research work, this paper reveals a relationship between the maximum absorption coefficient and the limit of the absorption frequency bandwidth. It has been demonstrated that the absorption frequency bandwidth can be extended up to 3 or 4 octaves as the diameters of the micro-holes decrease. This has become possible with the development of the technologies for manufacturing micro-perforated panels,such as laser drilling, powder metallurgy, welded meshing and electro-etching to form micrometer order holes. In this paper, absorption characteristics of such absorbers in random fields and in high sound intensity are discussed both theoretically and experimentally. A new absorbing structure based on micro-perforated-panel absorbers demonstrate experimentally high sound absorption capability. This review shows that the micro-perforated-panel absorber has potentials to be one of ideal absorbing materials in the 21st century.

  12. Micro-Expression Recognition Using Color Spaces.

    Science.gov (United States)

    Wang, Su-Jing; Yan, Wen-Jing; Li, Xiaobai; Zhao, Guoying; Zhou, Chun-Guang; Fu, Xiaolan; Yang, Minghao; Tao, Jianhua

    2015-12-01

    Micro-expressions are brief involuntary facial expressions that reveal genuine emotions and, thus, help detect lies. Because of their many promising applications, they have attracted the attention of researchers from various fields. Recent research reveals that two perceptual color spaces (CIELab and CIELuv) provide useful information for expression recognition. This paper is an extended version of our International Conference on Pattern Recognition paper, in which we propose a novel color space model, tensor independent color space (TICS), to help recognize micro-expressions. In this paper, we further show that CIELab and CIELuv are also helpful in recognizing micro-expressions, and we indicate why these three color spaces achieve better performance. A micro-expression color video clip is treated as a fourth-order tensor, i.e., a four-dimension array. The first two dimensions are the spatial information, the third is the temporal information, and the fourth is the color information. We transform the fourth dimension from RGB into TICS, in which the color components are as independent as possible. The combination of dynamic texture and independent color components achieves a higher accuracy than does that of RGB. In addition, we define a set of regions of interests (ROIs) based on the facial action coding system and calculated the dynamic texture histograms for each ROI. Experiments are conducted on two micro-expression databases, CASME and CASME 2, and the results show that the performances for TICS, CIELab, and CIELuv are better than those for RGB or gray.

  13. MICRO ELECTRICAL DISCHARGE MACHINING DEPOSITION IN AIR

    Institute of Scientific and Technical Information of China (English)

    JIN Baidong; ZHAO Wansheng; WANG Zhenlong; CAO Guohui

    2006-01-01

    A new deposition method is described using micro electrical discharge machining (EDM)to deposit tool electrode material on workpiece in air. The basic principles of micro electrical discharge deposition (EDD) are analyzed and the realized conditions are predicted. With an ordinary EDM shaping machine, brass as the electrode, high-speed steel as the workpiece, a lot of experiments are carried out on micro EDD systematically and thoroughly. The effects of major processing parameters, such as the discharge current, discharge duration, pulse interval and working medium, are obtained. As a result, a micro cylinder with 0.19 mm in diameter and 7.35 mm in height is deposited.By exchanging the polarities of the electrode and workpiece the micro cylinder can be removed selectively. So the reversible machining of deposition and removal is achieved, which breaks through the constraint of traditional EDM. Measurements show that the deposited material is compact and close to workpiece base, whose components depend on the tool electrode material.

  14. Micro-nanorobotic manipulation systems and their applications

    CERN Document Server

    Fukuda, Toshio; Nakajima, Masahiro

    2013-01-01

    Micro/Nano Robotics and Automation technologies have rapidly grown associated with the growth of Micro and Nanotechnologies. This book presents a summary of fundamentals in micro-nano scale engineering and the current state of the art of these technologies. “Micro-Nanorobotic Manipulation Systems and their Applications” introduces these advanced technologies from the basics and applications aspects of Micro/Nano-Robotics and Automation from the prospective micro/nano-scale manipulation. The book is organized in 9 chapters including an overview chapter of Micro/Nanorobotics and Automation technology from the historical view and important related research works. Further chapters are devoted to the physics of micro-nano fields as well as to material and science, microscopes, fabrication technology, importance of biological cell, and control techniques. Furthermore important examples, applications and a concise summary of Micro-Nanorobotics and Automation technologies are given.    

  15. Micro Products - Product Development and Design

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard

    2003-01-01

    -disciplinary competences. One example is sensors for chemical analysis of fluids, where chemistry, biology and flow mechanics all influence the design of the product and thereby the industrial fabrication of the product [1]. On the technological side the development has moved very fast, primarily driven by the need...... of the electronics industry to create still smaller chips with still larger capacity. Therefore the manufacturing technologies connected with micro/nano products in silicon are relatively highly developed compared to the technologies used for manufacturing micro products in metals, polymers and ceramics. For all...... technologies, however, it is a continuously increasing challenge to create the operational basis for an industrial production of micro products. As the products through product development processes are made applicable to a large number of customers, the pressure in regard to developing production technologies...

  16. Injection moulding for macro and micro products

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul

    The purpose of the literature survey is to investigate the injection moulding technology in the macro and micro areas from the basic to the state-of-the-art recent technology. Injection moulding is a versatile production process for the manufacturing of plastic parts and the process is extensively...... used for macro products but with the ages it is going deep into the micro areas having machine and process improvements. Extensive research work on injection moulding is going on all over the world. New ideas are flowing into the machines, materials and processes. The technology has made significant...... advancement in the area of micro injection moulding, multi-component and two component injection mounding. In near future it is likely to be the way of manufacturing moulded interconnects devices (MID) for a low cost integration of electrical and mechanical functionalities on a single device. This paper...

  17. Micro-CHP Systems for Residential Applications

    Energy Technology Data Exchange (ETDEWEB)

    Timothy DeValve; Benoit Olsommer

    2007-09-30

    Integrated micro-CHP (Cooling, Heating and Power) system solutions represent an opportunity to address all of the following requirements at once: conservation of scarce energy resources, moderation of pollutant release into our environment, and assured comfort for home-owners. The objective of this effort was to establish strategies for development, demonstration, and sustainable commercialization of cost-effective integrated CHP systems for residential applications. A unified approach to market and opportunity identification, technology assessment, specific system designs, adaptation to modular product platform component conceptual designs was employed. UTRC's recommendation to U.S. Department of Energy is to go ahead with the execution of the proposed product development and commercialization strategy plan under Phase II of this effort. Recent indicators show the emergence of micro-CHP. More than 12,000 micro-CHP systems have been sold worldwide so far, around 7,500 in 2004. Market projections predict a world-wide market growth over 35% per year. In 2004 the installations were mainly in Europe (73.5%) and in Japan (26.4%). The market in North-America is almost non-existent (0.1%). High energy consumption, high energy expenditure, large spark-spread (i.e., difference between electricity and fuel costs), big square footage, and high income are the key conditions for market acceptance. Today, these conditions are best found in the states of New York, Pennsylvania, New Jersey, Wisconsin, Illinois, Indiana, Michigan, Ohio, New England states. A multiple stage development plan is proposed to address risk mitigation. These stages include concept development and supplier engagement, component development, system integration, system demonstration, and field trials. A two stage commercialization strategy is suggested based on two product versions. The first version--a heat and power system named Micro-Cogen, provides the heat and essential electrical power to the

  18. MicroRNAs, epigenetics and disease

    DEFF Research Database (Denmark)

    Silahtaroglu, Asli; Stenvang, Jan

    2010-01-01

    Epigenetics is defined as the heritable chances that affect gene expression without changing the DNA sequence. Epigenetic regulation of gene expression can be through different mechanisms such as DNA methylation, histone modifications and nucleosome positioning. MicroRNAs are short RNA molecules...... which do not code for a protein but have a role in post-transcriptional silencing of multiple target genes by binding to their 3' UTRs (untranslated regions). Both epigenetic mechanisms, such as DNA methylation and histone modifications, and the microRNAs are crucial for normal differentiation...... diseases. In the present chapter we will mainly focus on microRNAs and methylation and their implications in human disease, mainly in cancer....

  19. [Surgical treatment of micro-ophthalmic syndromes].

    Science.gov (United States)

    Pellerin, P; Mouriaux, F; Dhellemmes-Defoort, S; Guilbert, F

    1997-10-01

    The complex embryology of the oculo-orbito-palpebral region is responsible for a number of heterogeneous clinicopathological situations, associating variable proportions of the three components of the malformation: micro-anophthalmia, microblepharism, micro-orbitism. Application of the double principle of skin expansion for the eyelids and distraction of the callus for the orbit, as early as possible (first year of life), is possible by means of a device which consists of a combination of an intraorbital expansion balloon, an antireflux valve to avoid effective pressure losses in the balloon, and an injection site for progressive filling of the expansion balloon. The response to these treatments is excellent for cases of simple microphthalmia and micro-orbitism; in complex craniofacial malformations, it generally only partially resolves the problem, but provides a precious complement to the quality of the final repair.

  20. The Aarhus Ion Micro-Trap Project

    DEFF Research Database (Denmark)

    Miroshnychenko, Yevhen; Nielsen, Otto; Poulsen, Gregers

    As part of our involvement in the EU MICROTRAP project, we have designed, manufactured and assembled a micro-scale ion trap with integrated optical fibers. These prealigned fibers will allow delivering cooling laser light to single ions. Therefore, such a trap will not require any direct optical...... access for laser cooling. All the parts for the trap have been made in our institute [1]. The electrodes and the spacers were laser cut in the collaboration with the group of P.  Balling. In our group we have developed a technique to manufacture lensed optical fibers. The trap is now assembled...... and installed in an ultra high vacuum chamber, which includes an ablation oven for all-optical loading of the trap [2]. The next steps on the project are to demonstrate the operation of the micro-trap and the cooling of ions using fiber delivered light. [1] D. Grant, Development of Micro-Scale Ion traps, Master...

  1. Laser based micro forming and assembly.

    Energy Technology Data Exchange (ETDEWEB)

    MacCallum, Danny O' Neill; Wong, Chung-Nin Channy; Knorovsky, Gerald Albert; Steyskal, Michele D.; Lehecka, Tom (Pennsylvania State University, Freeport, PA); Scherzinger, William Mark; Palmer, Jeremy Andrew

    2006-11-01

    It has been shown that thermal energy imparted to a metallic substrate by laser heating induces a transient temperature gradient through the thickness of the sample. In favorable conditions of laser fluence and absorptivity, the resulting inhomogeneous thermal strain leads to a measurable permanent deflection. This project established parameters for laser micro forming of thin materials that are relevant to MESA generation weapon system components and confirmed methods for producing micrometer displacements with repeatable bend direction and magnitude. Precise micro forming vectors were realized through computational finite element analysis (FEA) of laser-induced transient heating that indicated the optimal combination of laser heat input relative to the material being heated and its thermal mass. Precise laser micro forming was demonstrated in two practical manufacturing operations of importance to the DOE complex: micrometer gap adjustments of precious metal alloy contacts and forming of meso scale cones.

  2. MicroRNA and gynecological reproductive diseases.

    Science.gov (United States)

    Santamaria, Xavier; Taylor, Hugh

    2014-06-01

    MicroRNAs (miRNAs) are a class of small non-coding RNAs estimated to regulate the translation of mRNAs in 30% of all genes in animals by inhibiting translation. Aberrant miRNA expression is associated with many human diseases, including gynecological diseases, cancer, inflammatory diseases, and cardiovascular disorders. Abnormal expression of miRNAs has been observed in multiple human reproductive tract diseases including preeclampsia, endometrioid endometrial adenocarcinoma, uterine leiomyomata, ovarian carcinoma, endometriosis, and recurrent pregnancy loss. In the following review, an update of the role of microRNA and gynecological diseases is performed covering, not only impact of microRNA dysregulation in the origin of each disease, but also showing the potential useful diagnostic and therapeutic tool that miRNA may play in these gynecological pathologies.

  3. Micro Gas Turbine – A Review

    Directory of Open Access Journals (Sweden)

    Tushar Shukla

    2013-10-01

    Full Text Available Turbomachines is a class of machines which comprise of turbines and compressors. These machines are widely used for power generation, aircraft propulsion and in a wide range of heavy and medium industries. When we scale down these large turbines, we get micro turbines, which are compact and miniaturized form of these large turbines. The process of scaling down a turbine is not as simple as it looks like, it is a very tedious job and researches are going on in this area. These micro gas turbines are usually found with a power generating capacity of 250kW. They use any gas like natural gas, biogas, etc. as its input. The advantages of a micro gas turbine are that it has high expansion ratio and less moving components. The drawbacks of these turbines are that it requires high angular velocity as well as advanced electronics which can convert electricity of high frequency which gets produced into useful frequency of 50/60 Hz. This turbine is a very viable solution for distributed power generation which can be used for stationary energy applications. Also, micro gas turbine has found great use as cogeneration systems. These micro gas turbines can produce power between less than a kilowatt to hundreds of watts, which can be used for various purposes like electricity generation or head creation. These turbines are cost-effective, eco-friendly and pollution free as they can work by burning any gas like natural gas, land fill gas, etc. The manuscript presented gives an outlook on the past, present and future of these micro gas turbines. This paper will discuss the advantages and its uses. It will also discuss the drawbacks and the limitations of these turbines. This manuscript will prove to be a reference to all the researchers who want work in this field

  4. Machining Challenges: Macro to Micro Cutting

    Science.gov (United States)

    Shunmugam, M. S.

    2016-04-01

    Metal cutting is an important machining operation in the manufacture of almost all engineering components. Cutting technology has undergone several changes with the development of machine tools and cutting tools to meet challenges posed by newer materials, complex shapes, product miniaturization and competitive environments. In this paper, challenges in macro and micro cutting are brought out. Conventional and micro end-milling are included as illustrative examples and details are presented along with discussion. Lengthy equations are avoided to the extent possible, as the emphasis is on the basic concepts.

  5. Injection moulding for macro and micro products

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul

    used for macro products but with the ages it is going deep into the micro areas having machine and process improvements. Extensive research work on injection moulding is going on all over the world. New ideas are flowing into the machines, materials and processes. The technology has made significant......The purpose of the literature survey is to investigate the injection moulding technology in the macro and micro areas from the basic to the state-of-the-art recent technology. Injection moulding is a versatile production process for the manufacturing of plastic parts and the process is extensively...

  6. Online resources for microRNA analysis

    Directory of Open Access Journals (Sweden)

    Panagiotis Alexiou

    2011-02-01

    Full Text Available The use of online tools for bioinformatics analyses is becoming increasingly widespread. Resources specific to the field of microRNAs are available, varying in scope and usability. Online tools are the most useful for casual as well as power users since they need no installation, are hardware independent and are used mostly through graphic user interfaces and links to external sources. Here, we present an overview of useful online resources that have to do with microRNA genomics, gene finding, target prediction and functional analysis.

  7. Replication of micro and nano surface geometries

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; Hocken, R.J.; Tosello, Guido

    2011-01-01

    : manufacture of net-shape micro/nano surfaces, tooling (i.e. master making), and surface quality control (metrology, inspection). Replication processes and methods as well as the metrology of surfaces to determine the degree of replication are presented and classified. Examples from various application areas...... are given including replication for surface texture measurements, surface roughness standards, manufacture of micro and nano structured functional surfaces, replicated surfaces for optical applications (e.g. optical gratings), and process chains based on combinations of repeated surface replication steps....

  8. Advanced free-form micro tooling

    DEFF Research Database (Denmark)

    Tosello, Guido; Gavillet, J.

    2011-01-01

    The present deliverable contains the report of the work and results achieved within the framework of WP 2.2 in Tasks 2.2.4 “Advanced free-form micro tooling” in experimental research done regarding practical applications of methods of applying nano structures to tooling solutions. As part of Task 2...... of using chemical batch processes. The capability of different surface treatment methods of creating micro and nano structured adaptable mould inserts for subsequent polymer replication by injection moulding is investigated....

  9. Hollow micro string based calorimeter device

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a micron-scale calorimeter and a calorimetry method utilizing the micron-scale calorimeter. In accordance with the invention, there is provided a micron-scale calorimeter comprising a micro-channel string, being restrained at at least two longitudinally distanced...... positions so as to form a free released double clamped string in-between said two longitudinally distanced positions said micro-channel string comprising a microfluidic channel having a closed cross section and extending in the longitudinal direction of the hollow string, acoustical means adapted...

  10. Micro string resonators as temperature sensors

    DEFF Research Database (Denmark)

    Larsen, T.; Schmid, S.; Boisen, A.

    2013-01-01

    The resonance frequency of strings is highly sensitive to temperature. In this work we have investigated the applicability of micro string resonators as temperature sensors. The resonance frequency of strings is a function of the tensile stress which is coupled to temperature by the thermal...... was done with silicon rich silicon nitride (SiNx), nickel (Ni) and aluminum (Al) micro strings. Aluminum strings show a relative sensitivity of up to 15±1 %/°C, which is more than 100 times higher than values reported by other groups for similar devices. Sub-millisecond time constants can be achieved due...

  11. Cavity Pressure Behaviour in Micro Injection Moulding

    DEFF Research Database (Denmark)

    Griffiths, C.A.; Dimov, S.S.; Scholz, S.

    2010-01-01

    Process monitoring of micro injection moulding (µIM) is of crusial importance to analyse the effect of different parameter settings on the process and to assess its quality. Quality factors related to cavity pressure can provide useful information directly connected with the dyanmics of the process...... has been investigated by moulding a micro fluidic component on three different polymers (PP, ABS, PC) using the design of experiment approach. Similar trends such as the effects of a higher injection speed in decreasing the pressure work and of a lower temperature in decreasing pressure rate have been...

  12. The Surge of Micro-computers

    Science.gov (United States)

    Morita, Written By Ichiko; Matsumura, Translated By Tamiko

    Libraries in the United States are now experiencing another phase of rapid change brought by the sudden invasion of micro-computers. Their versatility has made available not only capabilities for word processing and producing spread sheets but also introduced new approaches to large research libraries’ information networks. OCLC’s microenhancers are one example of what is now available. They can be used for retrospective conversion, provide instruction for the use of and function as front end terminals for large online catalogs. Various new ideas for the application of micro-computers will bring interesting developments in library automation.

  13. Optical nano and micro actuator technology

    CERN Document Server

    Knopf, George K

    2012-01-01

    In Optical Nano and Micro Actuator Technology, leading engineers, material scientists, chemists, physicists, laser scientists, and manufacturing specialists offer an in-depth, wide-ranging look at the fundamental and unique characteristics of light-driven optical actuators. They discuss how light can initiate physical movement and control a variety of mechanisms that perform mechanical work at the micro- and nanoscale. The book begins with the scientific background necessary for understanding light-driven systems, discussing the nature of light and the interaction between light and NEMS/MEMS d

  14. Design and Prototyping of Micro Centrifugal Compressor

    Institute of Scientific and Technical Information of China (English)

    Shimpei Mizuki; Gaku Minorikawa; Toshiyuki Hirano; Yuichiro Asaga; Naoki Yamaguchi; Yutaka Ohta; Eisuke Outa

    2003-01-01

    In order to establish the design methodology of ultra micro centrifugal compressor, which is the most important component of ultra micro gas turbine unit, a 10 times of the final target size model was designed, prototyped and tested. The problems to be solved for downsizing were examined and 2-dimensional impeller was chosen as the first model due to its productivity. The conventional 1D prediction method, CFD and the inverse design were attempted. The prototyped compressor was driven by using a turbocharger and the performance characteristics were measured.

  15. Auto-communicating micro-orientalism

    DEFF Research Database (Denmark)

    Ren, Carina Bregnholm; Ooi, Can-Seng

    2013-01-01

    Using the concepts of auto-communication and micro-Orientalism, this article argues that nation branding at World Expos produces and propagates notions of difference and Otherness. We examine how Denmark presents itself in China, and how the message inevitably tells how the Danish authorities view...... exhibition is performed and regulated as sustainable and authentic and how in spite of its seemingly dialogical and interactive layout, a number of auto-communicative and micro-Orientalist practices are enacted. This study is based on field participation, observations and interviews. Public sources...

  16. Micro Learning: A Modernized Education System

    OpenAIRE

    Omer Jomah; Amamer Khalil Masoud; Xavier Patrick Kishore; Sagaya Aurelia

    2016-01-01

    Learning is an understanding of how the human brain is wired to learning rather than to an approach or a system. It is one of the best and most frequent approaches for the 21st century learners. Micro learning is more interesting due to its way of teaching and learning the content in a small, very specific burst. Here the learners decide what and when to learn. Content, time, curriculum, form, process, mediality, and learning type are the dimensions of micro learning. Our paper will discuss a...

  17. Micro Gas Turbine – A Review

    OpenAIRE

    2013-01-01

    Turbomachines is a class of machines which comprise of turbines and compressors. These machines are widely used for power generation, aircraft propulsion and in a wide range of heavy and medium industries. When we scale down these large turbines, we get micro turbines, which are compact and miniaturized form of these large turbines. The process of scaling down a turbine is not as simple as it looks like, it is a very tedious job and researches are going on in this area. These micro gas turbin...

  18. Micro-crystallography comes of age.

    Science.gov (United States)

    Smith, Janet L; Fischetti, Robert F; Yamamoto, Masaki

    2012-10-01

    The latest revolution in macromolecular crystallography was incited by the development of dedicated, user friendly, micro-crystallography beam lines. Brilliant X-ray beams of diameter 20 μm or less, now available at most synchrotron sources, enable structure determination from samples that previously were inaccessible. Relative to traditional crystallography, crystals with one or more small dimensions have diffraction patterns with vastly improved signal-to-noise when recorded with an appropriately matched beam size. Structures can be solved from isolated, well diffracting regions within inhomogeneous samples. This review summarizes the technological requirements and approaches to producing micro-beams and how they continue to change the practice of crystallography.

  19. Micro and nanoplatforms for biological cell analysis

    DEFF Research Database (Denmark)

    Svendsen, Winnie Edith; Castillo, Jaime; Moresco, Jacob Lange

    2010-01-01

    In this paper some of the technological platforms developed in our group for biological cell analysis will be highlighted. The paper first presents a short introduction pinpointing the advantages of using micro and nano technology in cellular studies. The issues of requiring transient analysis...... studies mimicking the in vivo situation is presented and an example of surface modification for cellular growth is described. Then novel electronic sensor platforms are discussed and an example of a nanosensor with electronic readout is given utilizing both micro- and nanotechnology. Finally an example...

  20. Micro- and nanoscale phenomena in tribology

    CERN Document Server

    Chung, Yip-Wah

    2011-01-01

    Drawn from presentations at a recent National Science Foundation Summer Institute on Nanomechanics, Nanomaterials, and Micro/Nanomanufacturing, Micro- and Nanoscale Phenomena in Tribology explores the convergence of the multiple science and engineering disciplines involved in tribology and the connection from the macro to nano world. Written by specialists from computation, materials science, mechanical engineering, surface physics, and chemistry, each chapter provides up-to-date coverage of both basic and advanced topics and includes extensive references for further study.After discussing the

  1. Rheological properties of polymer micro-gel dispersions

    Institute of Scientific and Technical Information of China (English)

    Dong Zhaoxia; Li Yahua; Lin Meiqin; Li Mingyuan

    2009-01-01

    The influence of swelling time, temperature, NaCI concentration and polymer micro-gel concentration on rheological properties of polymer micro-gel dispersions was studied by using a HAAKE rheometer. The results showed that with increasing swelling time and NaCI concentration, the polymer micro-gel dispersions changed from a shear-thickening fluid to a Newtonian fluid. The polymer micro- gel dispersion show shear-thinning in non-saline water. At higher swelling temperature, the time of the polymer micro-gel dispersion showing shear-thickening was shorter. With increasing polymer micro-gel concentration, the dispersion changed from shear-thickening to shear-thinning.

  2. Micro Flow Cytometer Chip Integrated with Micro-Pumps/Micro-Valves for Multi-Wavelength Cell Counting and Sorting

    Science.gov (United States)

    Chang, Chen-Min; Hsiung, Suz-Kai; Lee, Gwo-Bin

    2007-05-01

    Flow cytometry is a popular technique for counting and sorting of individual cells. This study presents a new chip-based flow cytometer capable of cell injection, counting and switching in an automatic format. The new microfluidic system is also capable of multi-wavelength detection of fluorescence-labeled cells by integrating multiple buried optical fibers within the chip. Instead of using large-scale syringe pumps, this study integrates micro-pumps and micro-valves to automate the entire cell injection and sorting process. By using pneumatic serpentine-shape (S-shape) micro-pumps to drive sample and sheath flows, the developed chip can generate hydrodynamic focusing to allow cells to pass detection regions in sequence. Two pairs of optical fibers are buried and aligned with the microchannels, which can transmit laser light sources with different wavelengths and can collect induced fluorescence signals. The cells labeled with different fluorescent dyes can be excited by the corresponding light source at different wavelengths. The fluorescence signals are then collected by avalanche photodiode (APD) sensors. Finally, a flow switching device composed of three pneumatic micro-valves is used for cell sorting function. Experimental data show that the developed flow cytometer can distinguish specific cells with different dye-labeling from mixed cell samples in one single process. The target cell samples can be also switched into appropriate outlet channels utilizing the proposed microvalve device. The developed microfluidic system is promising for miniature cell-based biomedical applications.

  3. Micro-masters of glioblastoma biology and therapy: increasingly recognized roles for microRNAs.

    Science.gov (United States)

    Floyd, Desiree; Purow, Benjamin

    2014-05-01

    MicroRNAs are small noncoding RNAs encoded in eukaryotic genomes that have been found to play critical roles in most biological processes, including cancer. This is true for glioblastoma, the most common and lethal primary brain tumor, for which microRNAs have been shown to strongly influence cell viability, stem cell characteristics, invasiveness, angiogenesis, metabolism, and immune evasion. Developing microRNAs as prognostic markers or as therapeutic agents is showing increasing promise and has potential to reach the clinic in the next several years. This succinct review summarizes current progress and future directions in this exciting and steadily expanding field.

  4. A CAMAC and FASTBUS engineering test environment supported by a MicroVAX/MicroVMS system

    Energy Technology Data Exchange (ETDEWEB)

    Logg, C.A.

    1987-10-01

    A flexible, multiuser engineering test environment has been established for the engineers in SLAC's Electronic Instrumentation Engineering group. The system hardware includes a standard MicroVAX II and MicroVAX I with multiple CAMAC, FASTBUS, and GPIB instrumentation buses. The system software components include MicroVMS licenses with DECNET/SLACNET, FORTRAN, PASCAL, FORTH, and a versatile graphical display package. In addition, there are several software utilities available to facilitate FASTBUS and CAMAC prototype hardware debugging. 16 refs., 7 figs.

  5. [The principle and analysis of micro-Fourier transform spectrometer based on MEMS micro-mirror].

    Science.gov (United States)

    Chen, Jian-Jun; Zhu, Yong; Liu, Bo; Wei, Wei; Zhang, Jie; Wang, Ning

    2012-11-01

    The present paper puts forward a novel micro-Fourier transform infrared spectrometer based on programmable MEMS micro-mirror. This design uses a MEMS micro-mirror and a slantwise reflector to replace the moving mirror system on traditional spectrometer. This paper analyzes the operating principle of this spectrometer and gives the simulation result to prove the feasibility of this method. The results show that the spectral resolution is less than 5 nm in near-infrared wave band, the wave-length accuracy is approximately 1 nm and the sampling period of this spectrometer is approximately 50 ms. This method can use Hadamard transform to improve the SNR.

  6. Design and fabrication of self-powered micro-harvesters rotating and vibrated micro-power systems

    CERN Document Server

    Pan, C T; Lin, Liwei; Chen, Ying-Chung

    2013-01-01

    Presents the latest methods for designing and fabricating self-powered micro-generators and energy harvester systems Design and Fabrication of Self-Powered Micro-Harvesters introduces the latest trends of self-powered generators and energy harvester systems, including the design, analysis and fabrication of micro power systems. Presented in four distinct parts, the authors explore the design and fabrication of: vibration-induced electromagnetic micro-generators; rotary electromagnetic micro-generators; flexible piezo-micro-generator with various widths; and PVDF electrospunpiezo-energy with

  7. AFM plough YBCO micro bridges: substrate effects

    CSIR Research Space (South Africa)

    Elkaseh, A

    2009-04-01

    Full Text Available AFM nanolithography was used as a novel cutting technique to define micro-size YBCO superconducting constrictions. Researchers studied the substrate effects on MgO and STO substrates and showed that the observed Shapiro steps from the bridges on STO...

  8. Deregulated microRNAs in multiple myeloma.

    Science.gov (United States)

    Benetatos, Leonidas; Vartholomatos, George

    2012-02-15

    MicroRNAs are short noncoding RNAS involved in gene expression regulation under physiological and pathological situations. They bind to mRNA of target genes and are potential regulators of gene expression at a post-transcription level through the RNA interference pathway. They are estimated to represent 1% to 2% of the known eukaryotic genome, and it has been demonstrated that they are involved in the pathogenesis of neurodegenerative diseases, cancer, metabolism disorders, and heart disease. MicroRNAs are known to act as tumor suppressors or oncogenes in cancer biology. The authors describe the current knowledge on microRNA involvement in regulatory pathways that characterize multiple myeloma pathogenesis gained from in vitro and in vivo studies. These small molecules interact with important factors such as p53, SOCS1, IGF-1, IGF-1R, vascular endothelial growth factor, NF-κB, and others. As such, microRNAs represent an attractive therapeutic target in the context of multiple myeloma interfering with the myeloma regulatory networks. Further studies are needed to better understand their role in myelomagenesis and their therapeutic potential.

  9. Manufacturing: 3D printed micro-optics

    Science.gov (United States)

    Juodkazis, Saulius

    2016-08-01

    Uncompromised performance of micro-optical compound lenses has been achieved by high-fidelity shape definition during two-photon absorption microfabrication. The lenses have been made directly onto image sensors and even onto the tip of an optic fibre.

  10. Micro-thermal analysis of polyester coatings

    NARCIS (Netherlands)

    Fischer, H.R.

    2010-01-01

    The application and suitability of micro-thermal analysis to detect changes in the chemical and physical properties of coating due to ageing and especially photo-degradation is demonstrated using a model polyester coating based on neopentyl glycol isophthalic acid. The changes in chemical structure

  11. Micro black holes in the laboratory

    CERN Document Server

    Bleicher, Marcus; Sprenger, Martin; Winstanley, Elizabeth

    2011-01-01

    The possibility of creating microscopic black holes is one of the most exciting predictions for the LHC, with potentially major consequences for our current understanding of physics. We briefly review the theoretical motivation for micro black hole production, and our understanding of their subsequent evolution. Recent work on modelling the radiation from quantum-gravity-corrected black holes is also discussed.

  12. Micro-Cavity Fluidic Dye Laser

    DEFF Research Database (Denmark)

    Helbo, Bjarne; Kristensen, Anders; Menon, Aric Kumaran

    2003-01-01

    We have successfully designed, fabricated and characterized a micro-cavity fluidic dye laser with metallic mirrors, which can be integrated with polymer based lab-on-a-chip microsystems without further processing steps. A simple rate-equation model is used to predict the average pumping power...

  13. Micro sphere with nanoporosity by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    He Jihuan [College of Science, Donghua University, 1882 Yan' an Xilu Road, Shanghai 200051 (China) and Modern Textile Institute, Donghua University, Shanghai (China)]. E-mail: jhhe@dhu.edu.cn; Liu Yong [College of Textile, Donghua University, Shanghai (China); Xu Lan [College of Science, Donghua University, 1882 Yan' an Xilu Road, Shanghai 200051 (China) and Modern Textile Institute, Donghua University, Shanghai (China); Yu Jianyong [Modern Textile Institute, Donghua University, Shanghai (China); College of Textile, Donghua University, Shanghai (China)

    2007-05-15

    Nanoporous structures are potentially of great technological interest for the development of electronic, catalytic and hydrogen-storage systems, invisibility device (e.g. stealth plane) and others. Here we describe a general strategy for the synthesis of micro sphere with nanoporosity by electrospinning, the porous sizes having uniform but tunable diameters can be controlled by voltage applied in the electrospinning process.

  14. Micro-fabricated all optical pressure sensors

    DEFF Research Database (Denmark)

    Havreland, Andreas Spandet; Petersen, Søren Dahl; Østergaard, Christian

    2017-01-01

    Optical pressure sensors can operate in certain harsh application areas where the electrical pressure sensors cannot. However, the sensitivity is often not as good for the optical sensors. This work presents an all optical pressure sensor, which is fabricated by micro fabrication techniques, wher...

  15. Micro Econometric Modelling of Household Energy Use

    DEFF Research Database (Denmark)

    Leth-Petersen, Søren

    2002-01-01

    Presents a micro econometric analysis of household electricity and natural gas demand for Danish households observed in 1996. Dependence between demand for gas and demand for electricity; Separability of demand for gas from demand for electricity; Relation between energy consumption and the age...

  16. MICRO AUTO GASIFICATION SYSTEM: EMISSIONS CHARACTERIZATION

    Science.gov (United States)

    A compact, CONEX-housed waste to energy unit, Micro Auto Gasification System (MAGS), was characterized for air emissions from burning of military waste types. The MAGS unit is a dual chamber gasifier with a secondary diesel-fired combustor. Eight tests were conducted with multipl...

  17. Surface micro topography replication in injection moulding

    DEFF Research Database (Denmark)

    Arlø, Uffe Rolf

    of the mechanisms controlling topography replication. Surface micro topography replication in injection moulding depends on the main elements of  Process conditions  Plastic material  Mould topography In this work, the process conditions is the main factor considered, but the impact of plastic material...

  18. Power Talk in DC Micro Grids

    DEFF Research Database (Denmark)

    Angjelichinoski, Marko; Stefanovic, Cedomir; Popovski, Petar

    2015-01-01

    Power talk is a novel concept for communication among units in a Micro Grid (MG), where information is sent by using power electronics as modems and the common bus of the MG as a communication medium. The technique is implemented by modifying the droop control parameters from the primary control...

  19. Surface Micro Topography Replication in Injection Moulding

    DEFF Research Database (Denmark)

    Arlø, Uffe Rolf; Hansen, Hans Nørgaard; Kjær, Erik Michael

    2005-01-01

    The surface micro topography of injection moulded plastic parts can be important for aesthetical and technical reasons. The quality of replication of mould surface topography onto the plastic surface depends among other factors on the process conditions. A study of this relationship has been...

  20. MICRO-COURSE OF CAVITATION EROSION

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhaoyun

    2008-01-01

    By cavitation tests and scanning electron microscope (SEM) microanalysis, the micro- appearance of cavitation samples is studied. It is the first time that the micro-appearance of metals is pursued successfully. According to the changing course of the micro-appearance of metals, the damaging course of cavitation erosion is determined. The destructive way of collapsing bubbles on the metal surface is known. Firstly cavitation pinholes appear on the metal surface, then cracks generate and grow under the action of collapsing bubbles. When cracks connect each other, small pieces are removed from pinhole wall and pinholes develop into cavitation pits. When the previous surface is removed completely, new pinholes are produced again on the new surface. A pinhole is the result of the powerful striking of a micro-liquid jet ejected by a large collapsed bubble near the surface. At some stages, cracks grow in the way of fatigue. The corrosion phenomenon is observed during the cavitation erosion. The cavitation pattern can be used to explain the cavitation pregnancy and the changing regulation of sample surface.

  1. Attaching substances to micro-organisms

    NARCIS (Netherlands)

    Buist, Girbe; Leenhouts, Cornelis Johannes; Venema, Gerard; Kok, Jan

    1999-01-01

    The invention relates to surface display of proteins on micro-organisms via the targeting and anchoring of heterologous proteins to the outer surface of cells such as yeast, fungi, mammalian and plant cells, and bacteria. The invention provides a proteinaceous substance comprising a reactive group a

  2. Demoulding force in micro-injection moulding

    DEFF Research Database (Denmark)

    Griffiths, C.A.; Dimov, S.S.; Scholz, S.

    2012-01-01

    The paper reports an experimental study that investigates part demoulding behavior in micro injection moulding (MIM) with a focus on the effects of pressure (P) and temperature (T) on the demoulding forces. Demoulding of a microfluidics part is conducted and the four processing parameters of melt...

  3. microRNA in Human Reproduction.

    Science.gov (United States)

    Eisenberg, Iris; Kotaja, Noora; Goldman-Wohl, Debra; Imbar, Tal

    2015-01-01

    microRNAs constitute a large family of approximately 21-nucleotide-long, noncoding RNAs. They emerged more than 20 years ago as key posttranscriptional regulators of gene expression. The regulatory role of these small RNA molecules has recently begun to be explored in the human reproductive system. microRNAs have been shown to play an important role in control of reproductive functions, especially in the processes of oocyte maturation, folliculogenesis, corpus luteum function, implantation, and early embryonic development. Knockout of Dicer, the cytoplasmic enzyme that cleaves the pre-miRNA to its mature form, results in postimplantation embryonic lethality in several animal models, attributing to these small RNA vital functions in reproduction and development. Another intriguing characteristic of microRNAs is their presence in body fluids in a remarkably stable form that is protected from endogenous RNase activity. In this chapter we will describe the current knowledge on microRNAs, specifically relating to human gonadal cells. We will focus on their role in the ovarian physiologic process and ovulation dysfunction, regulation of spermatogenesis and male fertility, and putative involvement in human normal and aberrant trophoblast differentiation and invasion through the process of placentation.

  4. Forming of Polymeric Tubular Micro-components

    DEFF Research Database (Denmark)

    Qin, Yi; Zhao, Jie; Anyasodor, Gerald;

    2015-01-01

    This chapter is intended to provide an overview of three nontraditional shaping technologies for the forming of polymeric micro-tubes, which are hot embossing, blow molding, and cross rolling, as well as realization of a process chain and the integration of a modular machine-based manufacturing...

  5. Micro-thermal analysis of polyester coatings

    NARCIS (Netherlands)

    Fischer, H.R.

    2010-01-01

    The application and suitability of micro-thermal analysis to detect changes in the chemical and physical properties of coating due to ageing and especially photo-degradation is demonstrated using a model polyester coating based on neopentyl glycol isophthalic acid. The changes in chemical structure

  6. Studying microRNAs in lymphoma

    NARCIS (Netherlands)

    Kluiver, Joost; Slezak-Prochazka, Izabella; van den Berg, Anke

    2013-01-01

    MicroRNAs (miRNAs) play important roles in development, differentiation, homeostasis, and also in diseases such as lymphoma. This chapter describes methods to study the role of miRNAs in lymphoma. First, we describe a multiplex RT reaction followed by qPCR that can be used to determine differential

  7. Recent advances in micro-vibration isolation

    Science.gov (United States)

    Liu, Chunchuan; Jing, Xingjian; Daley, Steve; Li, Fengming

    2015-05-01

    Micro-vibration caused by disturbance sources onboard spacecraft can severely degrade the working environment of sensitive payloads. Some notable vibration control methods have been developed particularly for the suppression or isolation of micro-vibration over recent decades. Usually, passive isolation techniques are deployed in aerospace engineering. Active isolators, however, are often proposed to deal with the low frequency vibration that is common in spacecraft. Active/passive hybrid isolation has also been effectively used in some spacecraft structures for a number of years. In semi-active isolation systems, the inherent structural performance can be adjusted to deal with variation in the aerospace environment. This latter approach is potentially one of the most practical isolation techniques for micro-vibration isolation tasks. Some emerging advanced vibration isolation methods that exploit the benefits of nonlinearity have also been reported in the literature. This represents an interesting and highly promising approach for solving some challenging problems in the area. This paper serves as a state-of-the-art review of the vibration isolation theory and/or methods which were developed, mainly over the last decade, specifically for or potentially could be used for, micro-vibration control.

  8. Micro hydro demo in the Philippines

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Philippine department of Energy (DOE) has signed a memorandum of agreement with the Japanese government for a P33.SM (US$0.67M) demonstration project. The 65kW micro hydro power system will benefit about 200 households in Leyte.

  9. MicroRNA mimicry blocks pulmonary fibrosis

    NARCIS (Netherlands)

    Montgomery, Rusty L; Yu, Guoying; Latimer, Paul A; Stack, Christianna; Robinson, Kathryn; Dalby, Christina M; Kaminski, Naftali; van Rooij, Eva

    2014-01-01

    Over the last decade, great enthusiasm has evolved for microRNA (miRNA) therapeutics. Part of the excitement stems from the fact that a miRNA often regulates numerous related mRNAs. As such, modulation of a single miRNA allows for parallel regulation of multiple genes involved in a particular diseas

  10. High precision laser forming for micro actuation

    NARCIS (Netherlands)

    Folkersma, Ger K.G.P.; Römer, G.R.B.E.; Brouwer, D.M.; Huis in 't Veld, A.J.; Nakata, Yoshiki; Xu, Xianfan; Roth, Stephan; Neuenschwander, Beat

    2014-01-01

    For assembly of micro-devices, such as photonic devices, the precision alignment of components is often critical for their performance. Laser forming, also known as laser-adjusting, can be used to create an integrated microactuator to align the components with sub-micron precision after bonding. In

  11. Micro Econometric Modelling of Household Energy Use

    DEFF Research Database (Denmark)

    Leth-Petersen, Søren

    2002-01-01

    Presents a micro econometric analysis of household electricity and natural gas demand for Danish households observed in 1996. Dependence between demand for gas and demand for electricity; Separability of demand for gas from demand for electricity; Relation between energy consumption and the age...

  12. Auto-communicating micro-orientalism

    DEFF Research Database (Denmark)

    Ren, Carina Bregnholm; Ooi, Can-Seng

    2013-01-01

    Using the concepts of auto-communication and micro-Orientalism, this article argues that nation branding at World Expos produces and propagates notions of difference and Otherness. We examine how Denmark presents itself in China, and how the message inevitably tells how the Danish authorities view...

  13. Beginning to understand microRNA function

    Institute of Scientific and Technical Information of China (English)

    Tingting Du; Phillip D Zamore

    2007-01-01

    @@ MicroRNAs (miRNAs) are -22 nt small RNAs expressed by plants, animals, viruses and at least one unicellular organism, the green alga, Chlamydomonas reinhardtii [1]. Most miRNAs are transcribed as primary miRNAs (pri-miRNAs) by RNA polymerase Ⅱ, although a few are transcribed by RNA polymerase Ⅲ.

  14. Characterization of cellulose nanofibrillation by micro grinding

    Science.gov (United States)

    Sandeep S. Nair; J.Y. Zhu; Yulin Deng; Arthur J. Ragauskas

    2014-01-01

    A fundamental understanding of the morphological development of cellulose fibers during fibrillation using micro grinder is very essential to develop effective strategies for process improvement and to reduce energy consumption. We demonstrated some simple measures for characterizing cellulose fibers fibrillated at different fibrillation times through the grinder. The...

  15. Sentences. MicroSIFT Courseware Evaluation.

    Science.gov (United States)

    Northwest Regional Educational Lab., Portland, OR.

    THE FOLLOWING IS THE FULL TEXT OF THIS DOCUMENT (Except for the Evaluation Summary Table): VERSION: Apple II. PRODUCER: Micro Power & Light Company, 12820 Hillcrest Rd., Suite 224, Dallas, Texas 75230. EVALUATION COMPLETED: June 1982 by the staff and constituents of the Portland Public Schools, Multnomah ESD, Portland, Oregon. COST: $24.95.…

  16. Circulation (Organs). MicroSIFT Courseware Evaluation.

    Science.gov (United States)

    Northwest Regional Educational Lab., Portland, OR.

    THE FOLLOWING IS THE FULL TEXT OF THIS DOCUMENT (Except for the Evaluation Summary Table): PRODUCER: Micro Power and Light Company, Keystone Park, Suite 1108, 13773 N. Central Expressway, Dallas, TX 75243. LOCAL DISTRIBUTORS: Contact producer for list. EVALUATION COMPLETED: Fall 1981. VERSION: Apple II. COST: $29.95. ABILITY LEVEL: Grades 5-12.…

  17. Self-assembly micro optical filter

    Science.gov (United States)

    Zhang, Ping (Cerina); Le, Kevin; Malalur-Nagaraja-Rao, Smitha; Hsu, Lun-Chen; Chiao, J.-C.

    2006-01-01

    Optical communication and sensor industry face critical challenges in manufacturing for system integration. Due to the assembly complexity and integration platform variety, micro optical components require costly alignment and assembly procedures, in which many required manual efforts. Consequently, self-assembly device architectures have become a great interest and could provide major advantages over the conventional optical devices. In this paper, we discussed a self-assembly integration platform for micro optical components. To demonstrate the adaptability and flexibility of the proposed optical device architectures, we chose a commercially available MEMS fabrication foundry service - MUMPs (Multi-User MEMS Process). In this work, polysilicon layers of MUMPS are used as the 3-D structural material for construction of micro component framework and actuators. However, because the polysilicon has high absorption in the visible and near infrared wavelength ranges, it is not suitable for optical interaction. To demonstrate the required optical performance, hybrid integration of materials was proposed and implemented. Organic compound materials were applied on the silicon-based framework to form the required optical interfaces. Organic compounds provide good optical transparency, flexibility to form filters or lens and inexpensive manufacturing procedures. In this paper, we have demonstrated a micro optical filter integrated with self-assembly structures. We will discuss the self-assembly mechanism, optical filter designs, fabrication issues and results.

  18. Cavity Pressure Behaviour in Micro Injection Moulding

    DEFF Research Database (Denmark)

    Griffiths, C.A.; Dimov, S.S.; Scholz, S.;

    2010-01-01

    has been investigated by moulding a micro fluidic component on three different polymers (PP, ABS, PC) using the design of experiment approach. Similar trends such as the effects of a higher injection speed in decreasing the pressure work and of a lower temperature in decreasing pressure rate have been...

  19. Micro- and nanotechnologies in plankton research

    Science.gov (United States)

    Mohammed, Javeed Shaikh

    2015-05-01

    A better understanding of the vast range of plankton and their interactions with the marine environment would allow prediction of their large-scale impact on the marine ecosystem, and provide in-depth knowledge on pollution and climate change. Numerous technologies, especially lab-on-a-chip microsystems, are being used to this end. Marine biofouling is a global issue with significant economic consequences. Ecofriendly polymer nanotechnologies are being developed to combat marine biofouling. Furthermore, nanomaterials hold great potential for bioremediation and biofuel production. Excellent reviews covering focused topics in plankton research exist, with only a handful discussing both micro- and nanotechnologies. This work reviews both micro- and nanotechnologies applied to broad-ranging plankton research topics including flow cytometry, chemotaxis/toxicity assays, biofilm formation, marine antifouling/fouling-release surfaces and coatings, green energy, green nanomaterials, microalgae immobilization, and bioremediation. It is anticipated that developments in plankton research will see engineered exploitation of micro- and nanotechnologies. The current review is therefore intended to promote micro-/nanotechnology researchers to team up with limnologists/oceanographers, and develop novel strategies for understanding and green exploitation of the complex marine ecosystem.

  20. Mechanics over micro and nano scales

    CERN Document Server

    Chakraborty, Suman

    2011-01-01

    Discusses the fundaments of mechanics over micro and nano scales in a level accessible to multi-disciplinary researchers, with a balance of mathematical details and physical principles Covers life sciences and chemistry for use in emerging applications related to mechanics over small scales Demonstrates the explicit interconnection between various scale issues and the mechanics of miniaturized systems

  1. A Micro-Grid Battery Storage Management

    DEFF Research Database (Denmark)

    Mahat, Pukar; Escribano Jiménez, Jorge; Moldes, Eloy Rodríguez

    2013-01-01

    systems under its administration. This paper presents an optimized scheduling of a micro-grid battery storage system that takes into account the next-day forecasted load and generation profiles and spot electricity prices. Simulation results show that the battery system can be scheduled close to optimal...

  2. Micro-Macro Paradoxes of Entrepreneurship

    DEFF Research Database (Denmark)

    Søgaard, Villy

    2008-01-01

    Artiklen tager afsæt i det såkaldte micro-macro paradox fra Aids-Efficiency litteraturen og argumenterer for, at en tilsvarende problemstilling bør inddrages i vurderingen af f.eks. de beskæftigelsesmæssige konsekvenser af entrepreneuriel virksomhed. Den påviser også i en gennemgang af litteraturen...

  3. Media selection for micro blasting medical parts.

    Science.gov (United States)

    Whelan, T

    2008-10-01

    Micro blasting is used in a range of applications including catheter, stent and pacemaker manufacturing. The correct media to use for the required surface is defined here together with some of the finer points of the process to ensure successful results.

  4. Micro GC's for Contaminant Monitoring in Spacecraft Air Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Based on the successful separation of 20 compounds using a 1 m coated microcolumn in Phase I, we propose to design a new micro-gas chromatograph (microGC) system to...

  5. Networks, Micro Small Enterprises (MSE'S) and Performance: the ...

    African Journals Online (AJOL)

    Networks, Micro Small Enterprises (MSE'S) and Performance: the Case of Kenya. ... Abstract. This paper examines the role of informal personal networks in determining. Micro Small Enterprises (MSE's) ... Article Metrics. Metrics Loading .

  6. Opportunities for Micro and Small Scale Businesses in the Tourism ...

    African Journals Online (AJOL)

    Opportunities for Micro and Small Scale Businesses in the Tourism Sector: The Case ... In the past, Kenya has concentrated on developing large scale tourism but this has ... to micro and small businesses (MSEs) in the hotel industry in Kenya.

  7. Thermal engineering and micro-technology; Thermique et microtechnologie

    Energy Technology Data Exchange (ETDEWEB)

    Kandlikar, S. [Rochester Inst. of Tech., NY (United States); Luo, L. [Institut National Polytechnique, 54 - Nancy (France); Gruss, A. [CEA Grenoble, GRETH, 38 (France); Wautelet, M. [Mons Univ. (Belgium); Gidon, S. [CEA Grenoble, Lab. d' Electronique et de Technologie de l' Informatique (LETI), 38 (France); Gillot, C. [Ecole Nationale Superieure d' Ingenieurs Electriciens de Grenoble, 38 - Saint Martin d' Heres (France)]|[CEA Grenoble, Lab. Electronique et de Technologie de l' Informatique (LETI), 38 (France); Therme, J.; Marvillet, Ch.; Vidil, R. [CEA Grenoble, 38 (France); Dutartre, D. [ST Microelectronique, France (France); Lefebvre, Ph. [SNECMA, 75 - Paris (France); Lallemand, M. [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France); Colin, S. [Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France); Joulin, K. [Ecole Nationale Superieure de Mecanique et d' Aerotechnique (ENSMA), 86 - Poitiers (France); Gad el Hak, M. [Virginia Univ., Charlottesville, VA (United States)

    2003-07-01

    This document gathers the abstracts and transparencies of 5 invited conferences of this congress of the SFT about heat transfers and micro-technologies: Flow boiling in microchannels: non-dimensional groups and heat transfer mechanisms (S. Kandlikar); Intensification and multi-scale process units (L. Luo and A. Gruss); Macro-, micro- and nano-systems: different physics? (M. Wautelet); micro-heat pipes (M. Lallemand); liquid and gas flows inside micro-ducts (S. Colin). The abstracts of the following presentations are also included: Electro-thermal writing of nano-scale memory points in a phase change material (S. Gidon); micro-technologies for cooling in micro-electronics (C. Gillot); the Minatec project (J. Therme); importance and trends of thermal engineering in micro-electronics (D. Dutartre); Radiant heat transfers at short length scales (K. Joulain); Momentum and heat transfer in micro-electromechanical systems (M. Gad-el-Hak). (J.S.)

  8. Micro Sourcing Strategic Framework for Low Income Group

    National Research Council Canada - National Science Library

    Noor Habibah Arshad; Siti Salwa Salleh; Syaripah Ruzaini Syed Aris; Norjansalika Janom; Norazam Mastuki

    2013-01-01

    .... These micro tasks are well-defined and then distributed to a group of workers. The objective of this study is to develop the strategic framework of micro sourcing to generate income for the low income group...

  9. Experiences with micro finance in improving rural livelihoods: a case ...

    African Journals Online (AJOL)

    Mo

    micro-finance institutions that address needs of different levels of recipients. ... micro-finance management and provides proposals for its out-scaling among smallholder farmers and the rural poor in .... borrowers should manage risk effectively!

  10. MicroRNAs as regulatory elements in psoriasis

    Directory of Open Access Journals (Sweden)

    Liu Yuan

    2016-01-01

    Full Text Available Psoriasis is a chronic, autoimmune, and complex genetic disorder that affects 23% of the European population. The symptoms of Psoriatic skin are inflammation, raised and scaly lesions. microRNA, which is short, nonprotein-coding, regulatory RNAs, plays critical roles in psoriasis. microRNA participates in nearly all biological processes, such as cell differentiation, development and metabolism. Recent researches reveal that multitudinous novel microRNAs have been identified in skin. Some of these substantial novel microRNAs play as a class of posttranscriptional gene regulator in skin disease, such as psoriasis. In order to insight into microRNAs biological functions and verify microRNAs biomarker, we review diverse references about characterization, profiling and subtype of microRNAs. Here we will share our opinions about how and which microRNAs are as regulatory in psoriasis.

  11. Micro-Combined Heat and Power Device Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — NIST has developed a test facility for micro-combined heat and power (micro-CHP) devices to measure their performance over a range of different operating strategies...

  12. Accounting Systems in Small and Micro Enterprises in Kenya ...

    African Journals Online (AJOL)

    Accounting Systems in Small and Micro Enterprises in Kenya. ... PROMOTING ACCESS TO AFRICAN RESEARCH ... means to small and micro traders in Kenya, by reviewing the practices and principles they use in running their businesses.

  13. The micro turbine: the MIT example; La micro turbine: l'exemple du MIT

    Energy Technology Data Exchange (ETDEWEB)

    Ribaud, Y. [Office National d' Etudes et de Recherches Aerospatiales (ONERA-DEFA), 92 - Chatillon (France)

    2001-10-01

    The micro turbine study began a few years ago at the MIT, with the participation of specialists from different fields. The purpose is the development of a MEMS (micro electro mechanical systems) based, 1 cm in diameter, micro gas turbine. Potential applications are devoted to micro drone propulsion, electric power generation for portable power sources in order to replace heavy Lithium batteries, satellite motorization, the surface distributed power for boundary suction on plane wings. The manufacturing constraints at such small scales lead to 2-D extruded shapes. The physical constraints stem from viscous effects and from limitations given by 2-D geometry. The time scales are generally shorter than for conventional machines. Otherwise the material properties are better at such length scales. Transposition from conventional turbomachinery laws is no more applicable and new design methods must be established. The present paper highlights the project progress and the technology breakthroughs. (author)

  14. Acoustic micro-Doppler radar for human gait imaging.

    Science.gov (United States)

    Zhang, Zhaonian; Pouliquen, Philippe O; Waxman, Allen; Andreou, Andreas G

    2007-03-01

    A portable acoustic micro-Doppler radar system for the acquisition of human gait signatures in indoor and outdoor environments is reported. Signals from an accelerometer attached to the leg support the identification of the components in the measured micro-Doppler signature. The acoustic micro-Doppler system described in this paper is simpler and offers advantages over the widely used electromagnetic wave micro-Doppler radars.

  15. Towards the first generation micro bulk forming system

    DEFF Research Database (Denmark)

    Arentoft, Mogens; Eriksen, Rasmus Solmer; Hansen, Hans Nørgaard

    2011-01-01

    The industrial demand for micro mechanical components has surged in the later years with the constant introduction of more integrated products. The micro bulk forming process holds a promising pledge of delivering high quality micro mechanical components at low cost and high production rates. Thi...... press. The system is demonstrated on an advanced micro forming case where a dental component is formed in medical grade Titanium....

  16. MicroRNA: Biogenesis, Function and Role in Cancer

    OpenAIRE

    2010-01-01

    MicroRNAs are small, highly conserved non-coding RNA molecules involved in the regulation of gene expression. MicroRNAs are transcribed by RNA polymerases II and III, generating precursors that undergo a series of cleavage events to form mature microRNA. The conventional biogenesis pathway consists of two cleavage events, one nuclear and one cytoplasmic. However, alternative biogenesis pathways exist that differ in the number of cleavage events and enzymes responsible. How microRNA precursors...

  17. Expression profiling identifies microRNA signature in pancreatic cancer

    OpenAIRE

    Lee, Eun Joo; Gusev, Yuriy; Jiang, Jinmai; Gerard J Nuovo; Lerner, Megan R; Frankel, Wendy L.; Morgan, Daniel L.; Postier, Russell G.; Brackett, Daniel J; Schmittgen, Thomas D.

    2007-01-01

    microRNAs are functional, 22 nt, noncoding RNAs that negatively regulate gene expression. Disturbance of microRNA expression may play a role in the initiation and progression of certain diseases. A microRNA expression signature has been identified that is associated with pancreatic cancer. This has been accomplished with the application of real-time PCR profiling of over 200 microRNA precursors on specimens of human pancreatic adenocarcinoma, paired benign tissue, normal pancreas, chronic pan...

  18. Role of MicroRNA in Aggressive Prostate Cancer

    Science.gov (United States)

    2014-07-01

    AD_________________ Award Number: W81XWH-11-1-0491 TITLE: Role of MicroRNA in Aggressive Prostate... MicroRNA in Aggressive Prostate Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-11-1-0491 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Jer...action is not fully characterized. Using microRNA microarray screening, we found microRNA -363 (miR363) is significantly down regulated in several

  19. The Model of Optimization of Micro Energy; HOMER: El Modelo de Optimizacin de Micro energa

    Energy Technology Data Exchange (ETDEWEB)

    2004-05-01

    HOMER, the model of optimization of micro energy, helps to disear systems out of the network and interconnected to the network. You can use HOMER to carry out the analysis to explore an extensive rank of questions of diseo. HOMER, el modelo de optimizacin de micro energa, le ayuda a disear sistemas fuera de la red e interconectados a la red. Usted puede usar HOMER para llevar a cabo el anlisis para explorar un amplio rango de preguntas de diseo.

  20. A Micro-PIV Study of the Pulsed Micro-Flows Driven by an Insulin Pump

    Science.gov (United States)

    Wang, Bing; Demuren, Ayodeji; Gyuricsko, Eric; Hu, Hui

    2009-11-01

    In recent years, there is a surge in the popularity of using insulin pump or continuous subcutaneous insulin infusion therapy, as opposed to multiple daily injections by insulin syringe or an insulin pen. Some case studies have suggested that insulin delivery failure may be caused by precipitation of insulin within the infusion set. Speculation also exists that the flow of insulin through an insulin infusion set may be reduced or inhibited by air bubbles entrained into the micro-sized tubing system since there are chances that air be introduced into the insulin reservoir during the filling process. In the present study, a microscopic Particle Image Velocimtry (micro-PIV) system was used to characterize the transient behavior of the pulsed micro-flows inside the micro-sized tubing system of an insulin infusion set with insulin pump operating in basal mode (i.e., pulsed insulin pumping). The effects of the air bubbles entrained into the micro-sized tubing system on the insulin delivery process were assessed based on the micro-PIV measurements.

  1. DIANA-microT web server: elucidating microRNA functions through target prediction.

    Science.gov (United States)

    Maragkakis, M; Reczko, M; Simossis, V A; Alexiou, P; Papadopoulos, G L; Dalamagas, T; Giannopoulos, G; Goumas, G; Koukis, E; Kourtis, K; Vergoulis, T; Koziris, N; Sellis, T; Tsanakas, P; Hatzigeorgiou, A G

    2009-07-01

    Computational microRNA (miRNA) target prediction is one of the key means for deciphering the role of miRNAs in development and disease. Here, we present the DIANA-microT web server as the user interface to the DIANA-microT 3.0 miRNA target prediction algorithm. The web server provides extensive information for predicted miRNA:target gene interactions with a user-friendly interface, providing extensive connectivity to online biological resources. Target gene and miRNA functions may be elucidated through automated bibliographic searches and functional information is accessible through Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The web server offers links to nomenclature, sequence and protein databases, and users are facilitated by being able to search for targeted genes using different nomenclatures or functional features, such as the genes possible involvement in biological pathways. The target prediction algorithm supports parameters calculated individually for each miRNA:target gene interaction and provides a signal-to-noise ratio and a precision score that helps in the evaluation of the significance of the predicted results. Using a set of miRNA targets recently identified through the pSILAC method, the performance of several computational target prediction programs was assessed. DIANA-microT 3.0 achieved there with 66% the highest ratio of correctly predicted targets over all predicted targets. The DIANA-microT web server is freely available at www.microrna.gr/microT.

  2. Micro-processus et macro-structures

    Directory of Open Access Journals (Sweden)

    Aaron Victor Cicourel

    2008-10-01

    Full Text Available Des approches sociologiques traditionnelles ont défini des macro-structures sociales comme un niveau particulier de la réalité sociale, à distinguer des micro-épisodes de l’action sociale. Cela les a conduits à concevoir ces macro-structures et à mener des recherches sur elles de manière plus ou moins indépendante des pratiques observables de la vie quotidienne. Cicourel soutient que les faits (macro-sociaux ne sont pas simplement donnés, mais émergent de pratiques routinières de la vie de tous les jours. Le macro, au sens de descriptions résumées, hors contexte, normalisées et typifiées, est un produit typique des procédures interactives et organisationnelles qui transforment les micro-événements en structures macro-sociales. Ainsi une précondition pour l’intégration des phénomènes micro- et macro-sociaux dans notre théorie et dans notre méthodologie renvoie à l’identification des processus contribuant à la création de macro-structures par des inférences routinières, des interprétations et des procédure de résumé. Le texte montre aussi que les différences entre approches micro-sociologiques apparaissent parallèles à celles existant entre approches micro et macro. On se centrant sur de petits fragments d’interactions conversationnelles, certains travaux micro-sociologiques tendent à ignorer ce qui informe ces interactions conversationnelles pour les participants eux-mêmes. Les comptes rendus décontextualisés produits par de telles méthodes ressemblent à la décontextualisation résultant des procédures macro-sociologiques d’agrégation. Contre cela, Cicourel défend la constitution de bases de données comparatives n’incluant pas seulement le contexte des interactions de face à face, mais étudiant aussi les phénomènes sociaux de manière systématique à travers différents contextes.Micro-processes and macro-structures. Notes on articulation between different levels of analysis

  3. Radar Micro-Doppler classification of Mini-UAVs

    NARCIS (Netherlands)

    Harmanny, R.L.A.; Prémel-Cabic, G.; Wit, J.J.M.

    2015-01-01

    The radar micro-Doppler signature of a target depends on its micro-motion, i.e., the motion of parts of a target relative to the motion of the target as a whole. These micro-motions are very characteristic considering different target classes, e.g., the slow pendulum-like motion of a bird’s wings ve

  4. A micromachined piezoelectric microgripper for manipulation of micro/nanomaterials

    Science.gov (United States)

    Shi, Huaduo; Shi, Weiliang; Zhang, Ran; Zhai, Junyi; Chu, Jinkui; Dong, Shuxiang

    2017-06-01

    Micro/nanomaterials and devices have attracted great interest in recent years because of their extensive application prospects in almost all kinds of fields. However, the manipulations of the material at the micro/nanoscale, such as the separation or transfer of a micro/nano-object in the process of assembling micro/nanodevices, are quite difficult. In this paper, we present a micromachined micro-gripper made of photoresist material (SU-8) and driven by piezoelectric Pb(Mg,Nb)O3-PbTiO3 single crystal pieces. In order to keep two grasping jaws of the micro-gripper operating in the same plane at the micro/nanometer scale, a fine circular flexure hinge was fabricated for elastically connecting them together. After introducing the interface effect, the relationship between the opening stroke of two jaws and the applied voltage was developed and then confirmed by finite element simulation. The micro-gripper was finally installed on a six degree of freedom stage for performing a pick-up, release, and transfer manipulation of a 2 μm ZnO micro-fiber. The presented piezoelectric micro-gripper shows a great potential for the precise manipulation of a single piece of micro/nanomaterial for micro/nanodevices' assembling.

  5. A micromachined piezoelectric microgripper for manipulation of micro/nanomaterials.

    Science.gov (United States)

    Shi, Huaduo; Shi, Weiliang; Zhang, Ran; Zhai, Junyi; Chu, Jinkui; Dong, Shuxiang

    2017-06-01

    Micro/nanomaterials and devices have attracted great interest in recent years because of their extensive application prospects in almost all kinds of fields. However, the manipulations of the material at the micro/nanoscale, such as the separation or transfer of a micro/nano-object in the process of assembling micro/nanodevices, are quite difficult. In this paper, we present a micromachined micro-gripper made of photoresist material (SU-8) and driven by piezoelectric Pb(Mg,Nb)O3-PbTiO3 single crystal pieces. In order to keep two grasping jaws of the micro-gripper operating in the same plane at the micro/nanometer scale, a fine circular flexure hinge was fabricated for elastically connecting them together. After introducing the interface effect, the relationship between the opening stroke of two jaws and the applied voltage was developed and then confirmed by finite element simulation. The micro-gripper was finally installed on a six degree of freedom stage for performing a pick-up, release, and transfer manipulation of a 2 μm ZnO micro-fiber. The presented piezoelectric micro-gripper shows a great potential for the precise manipulation of a single piece of micro/nanomaterial for micro/nanodevices' assembling.

  6. The repertoire and features of human platelet microRNAs.

    Directory of Open Access Journals (Sweden)

    Hélène Plé

    Full Text Available Playing a central role in the maintenance of hemostasis as well as in thrombotic disorders, platelets contain a relatively diverse messenger RNA (mRNA transcriptome as well as functional mRNA-regulatory microRNAs, suggesting that platelet mRNAs may be regulated by microRNAs. Here, we elucidated the complete repertoire and features of human platelet microRNAs by high-throughput sequencing. More than 492 different mature microRNAs were detected in human platelets, whereas the list of known human microRNAs was expanded further by the discovery of 40 novel microRNA sequences. As in nucleated cells, platelet microRNAs bear signs of post-transcriptional modifications, mainly terminal adenylation and uridylation. In vitro enzymatic assays demonstrated the ability of human platelets to uridylate microRNAs, which correlated with the presence of the uridyltransferase enzyme TUT4. We also detected numerous microRNA isoforms (isomiRs resulting from imprecise Drosha and/or Dicer processing, in some cases more frequently than the reference microRNA sequence, including 5' shifted isomiRs with redirected mRNA targeting abilities. This study unveils the existence of a relatively diverse and complex microRNA repertoire in human platelets, and represents a mandatory step towards elucidating the intraplatelet and extraplatelet role, function and importance of platelet microRNAs.

  7. Radar Micro-Doppler classification of Mini-UAVs

    NARCIS (Netherlands)

    Harmanny, R.L.A.; Prémel-Cabic, G.; Wit, J.J.M.

    2015-01-01

    The radar micro-Doppler signature of a target depends on its micro-motion, i.e., the motion of parts of a target relative to the motion of the target as a whole. These micro-motions are very characteristic considering different target classes, e.g., the slow pendulum-like motion of a bird’s wings

  8. Radar micro-doppler signatures processing and applications

    CERN Document Server

    Chen, Victor C; Miceli, William J

    2014-01-01

    Radar Micro-Doppler Signatures: Processing and applications concentrates on the processing and application of radar micro-Doppler signatures in real world situations, providing readers with a good working knowledge on a variety of applications of radar micro-Doppler signatures.

  9. Micro digital sun sensor: system in a package

    NARCIS (Netherlands)

    Boom, C.W. de; Leijtens, J.A.P.; Duivenbode, L.M.H. van; Heiden, N. van der

    2004-01-01

    A novel micro Digital Sun Sensor (μDSS) is under development in the frame of a micro systems technology (MST) development program (Microned) from the Dutch Ministry of Economic Affairs. Use of available micro system technologies in combination with the implementation of a dedicated solarcell for pow

  10. Thermal Actuation for Precision Micro Motion and Positioning

    NARCIS (Netherlands)

    Paalvast, S.L.

    2010-01-01

    The primary goal of this research was to study the feasibility of a thermal micro actuator for improved tracking performance of a Hard Disk Drive (HDD), and the feasibility of thermal actuation for precision micro motion and positioning in general. The fast dynamics of the micro actuator allows it t

  11. Thermal Actuation for Precision Micro Motion and Positioning

    NARCIS (Netherlands)

    Paalvast, S.L.

    2010-01-01

    The primary goal of this research was to study the feasibility of a thermal micro actuator for improved tracking performance of a Hard Disk Drive (HDD), and the feasibility of thermal actuation for precision micro motion and positioning in general. The fast dynamics of the micro actuator allows it t

  12. Tool Neck Geometry Design to Improve Stiffness of Micro Endmills

    NARCIS (Netherlands)

    Li, P.; Rozing, M.; Oosterling, J.A.J.; Hoogstrate, A.M.; Langen, H.H.

    2008-01-01

    Due to the scaling effect, micro endmills have low stiffness in nature, which will result in lose of form accuracy in workpiece and vibration of micro tools during micromilling process. Through analytical modeling, it is found that the neck geometry of the micro endmill has a big influence on the to

  13. A screwing device for handling and assembly of micro screws

    DEFF Research Database (Denmark)

    Gegeckaite, Asta; Hansen, Hans Nørgaard; Eriksson, Torbjörn Gerhard

    2007-01-01

    Nowadays, the application of specially designed handling devices in micro technology is an important topic and a necessity for the industry. Conventional methods for screwing can not be applied directly to micro screws. This is caused by the 3D micro object geometry and dimensions which inducing ...

  14. Micro digital sun sensor: system in a package

    NARCIS (Netherlands)

    Boom, C.W. de; Leijtens, J.A.P.; Duivenbode, L.M.H. van; Heiden, N. van der

    2004-01-01

    A novel micro Digital Sun Sensor (μDSS) is under development in the frame of a micro systems technology (MST) development program (Microned) from the Dutch Ministry of Economic Affairs. Use of available micro system technologies in combination with the implementation of a dedicated solarcell for pow

  15. Micro digital sun sensor: system in a package

    NARCIS (Netherlands)

    Boom, C.W. de; Leijtens, J.A.P.; Duivenbode, L.M.H. van; Heiden, N. van der

    2004-01-01

    A novel micro Digital Sun Sensor (μDSS) is under development in the frame of a micro systems technology (MST) development program (Microned) from the Dutch Ministry of Economic Affairs. Use of available micro system technologies in combination with the implementation of a dedicated solarcell for

  16. Micro-CHP Systems for Residential Applications

    Energy Technology Data Exchange (ETDEWEB)

    Timothy DeValve; Benoit Olsommer

    2007-09-30

    Integrated micro-CHP (Cooling, Heating and Power) system solutions represent an opportunity to address all of the following requirements at once: conservation of scarce energy resources, moderation of pollutant release into our environment, and assured comfort for home-owners. The objective of this effort was to establish strategies for development, demonstration, and sustainable commercialization of cost-effective integrated CHP systems for residential applications. A unified approach to market and opportunity identification, technology assessment, specific system designs, adaptation to modular product platform component conceptual designs was employed. UTRC's recommendation to U.S. Department of Energy is to go ahead with the execution of the proposed product development and commercialization strategy plan under Phase II of this effort. Recent indicators show the emergence of micro-CHP. More than 12,000 micro-CHP systems have been sold worldwide so far, around 7,500 in 2004. Market projections predict a world-wide market growth over 35% per year. In 2004 the installations were mainly in Europe (73.5%) and in Japan (26.4%). The market in North-America is almost non-existent (0.1%). High energy consumption, high energy expenditure, large spark-spread (i.e., difference between electricity and fuel costs), big square footage, and high income are the key conditions for market acceptance. Today, these conditions are best found in the states of New York, Pennsylvania, New Jersey, Wisconsin, Illinois, Indiana, Michigan, Ohio, New England states. A multiple stage development plan is proposed to address risk mitigation. These stages include concept development and supplier engagement, component development, system integration, system demonstration, and field trials. A two stage commercialization strategy is suggested based on two product versions. The first version--a heat and power system named Micro-Cogen, provides the heat and essential electrical power to the

  17. Effect of Saliva on Measurement of Chemiluminescence by a Micro-Reactor Incorporating a Micro-Channel

    OpenAIRE

    Tsukagoshi, Kazuhiko; Fukumoto, Kazuaki; Nakajima, Riichiro; Yamashita, Kenichi; Maeda, Hideaki

    2007-01-01

    Effect of saliva on measurement of chemiluminescence was examined by a micro-reactor incorporating a micro-channel. Sodium hypochlorite and hydrogen peroxide solutions were delivered into a micro-channel developed in a micro-reactor by a syringe pump, providing a laminar flow liquid-liquid interface in the channel and leading to chemiluminescence from singlet oxygen. It was found under certain conditions including saliva that ca. 5% chemiluminescence of the total chemiluminescence was lost in...

  18. High precision micro-scale Hall Effect characterization method using in-line micro four-point probes

    DEFF Research Database (Denmark)

    Petersen, Dirch Hjorth; Hansen, Ole; Lin, Rong

    2008-01-01

    and experimental measurements, that the repeatability of a micro-scale Hall effect measurement is better than 1 %. We demonstrate the ability to spatially resolve Hall effect on micro-scale by characterization of an USJ with a single laser stripe anneal. The micro sheet resistance variations resulting from...

  19. Integrated analysis of microRNA and mRNA expression: Adding biological significance to microRNA target predictions

    NARCIS (Netherlands)

    M. van Iterson (Mat); S. Bervoets (Sander); E.J. de Meijer (Emile); H.P. Buermans (Henk); P.A.C. 't Hoen (Peter); R.X. Menezes (Renée); J.M. Boer (Judith)

    2013-01-01

    textabstractCurrent microRNA target predictions are based on sequence information and empirically derived rules but do not make use of the expression of microRNAs and their targets. This study aimed to improve microRNA target predictions in a given biological context, using in silico predictions, mi

  20. MicroRNA expression profiling of the porcine developing brain

    DEFF Research Database (Denmark)

    Podolska, Agnieszka; Kaczkowski, Bogumil; Busk, Peter Kamp;

    2011-01-01

    MicroRNAs are small, non-coding RNA molecules that regulate gene expression at the post-transcriptional level and play an important role in the control of developmental and physiological processes. In particular, the developing brain contains an impressive diversity of microRNAs. Most micro...... and the growth curve when compared to humans. Considering these similarities, studies examining microRNA expression during porcine brain development could potentially be used to predict the expression profile and role of microRNAs in the human brain....

  1. MicroRNA Expression Profiling of the Porcine Developing Brain

    DEFF Research Database (Denmark)

    Podolska, Agnieszka; Kaczkowski, Bogumil; Busk, Peter Kamp

    2011-01-01

    MicroRNAs are small, non-coding RNA molecules that regulate gene expression at the post-transcriptional level and play an important role in the control of developmental and physiological processes. In particular, the developing brain contains an impressive diversity of microRNAs. Most microRNA...... and the growth curve when compared to humans. Considering these similarities, studies examining microRNA expression during porcine brain development could potentially be used to predict the expression profile and role of microRNAs in the human brain....

  2. Solid catalytic growth mechanism of micro-coiled carbon fibers

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Micro-coiled carbon fibers were prepared by catalytic pyrolysisof acetylene with nano-sized nickel powder catalyst using the substrate method. The morphology of micro-coiled carbon fibers was observed through field emission scanning electron microscopy. It was found that the fiber and coil diameter of the obtained micro-coiled carbon fibers is about 500—600 nm and 4—5 μm, respectively. Most of the micro-coiled carbon fibers obtained were regular double carbon coils, but a few irregular ones were also observed. On the basis of the experimental observation, a solid catalytic growth mechanism of micro-coiled carbon fibers was proposed.

  3. Micro-system inertial sensing technology overview.

    Energy Technology Data Exchange (ETDEWEB)

    Allen, James Joe

    2009-02-01

    The purpose of this report is to provide an overview of Micro-System technology as it applies to inertial sensing. Transduction methods are reviewed with capacitance and piezoresistive being the most often used in COTS Micro-electro-mechanical system (MEMS) inertial sensors. Optical transduction is the most recent transduction method having significant impact on improving sensor resolution. A few other methods are motioned which are in a R&D status to hopefully allow MEMS inertial sensors to become viable as a navigation grade sensor. The accelerometer, gyroscope and gravity gradiometer are the type of inertial sensors which are reviewed in this report. Their method of operation and a sampling of COTS sensors and grade are reviewed as well.

  4. Vision-guidance of micro- and nanorobots

    Science.gov (United States)

    Wortmann, T.; Dahmen, C.; Fatikow, S.

    2012-01-01

    This paper presents a selection of image processing methods and algorithms, which are needed to enable the reliable automation of robotic tasks at the micro and nanoscale. Application examples are automatic assembly of new nanoscale electronic elements or automatic testing of material properties. Due to the very small object dimensions targeted here, the scanning electron microscope is the appropriate image sensor. The methods described in this paper can be categorized into procedures of object recognition and object tracking. Object recognition deals with the problem of finding and labeling nanoscale objects in an image scene, whereas tracking is the process of continuously following the movement of a specific object. Both methods carried out subsequently enable fully automated robotic tasks at the micro- and nanoscale. A selection of algorithms is demonstrated and found suitable.

  5. Micro-separation toward systems biology.

    Science.gov (United States)

    Liu, Bi-Feng; Xu, Bo; Zhang, Guisen; Du, Wei; Luo, Qingming

    2006-02-17

    Current biology is experiencing transformation in logic or philosophy that forces us to reevaluate the concept of cell, tissue or entire organism as a collection of individual components. Systems biology that aims at understanding biological system at the systems level is an emerging research area, which involves interdisciplinary collaborations of life sciences, computational and mathematical sciences, systems engineering, and analytical technology, etc. For analytical chemistry, developing innovative methods to meet the requirement of systems biology represents new challenges as also opportunities and responsibility. In this review, systems biology-oriented micro-separation technologies are introduced for comprehensive profiling of genome, proteome and metabolome, characterization of biomolecules interaction and single cell analysis such as capillary electrophoresis, ultra-thin layer gel electrophoresis, micro-column liquid chromatography, and their multidimensional combinations, parallel integrations, microfabricated formats, and nano technology involvement. Future challenges and directions are also suggested.

  6. DROPWISE CONDENSATION ON MICRO- AND NANOSTRUCTURED SURFACES

    Energy Technology Data Exchange (ETDEWEB)

    Enright, R; Miljkovic, N; Alvarado, JL; Kim, K; Rose, JW

    2014-07-23

    In this review we cover recent developments in the area of surface-enhanced dropwise condensation against the background of earlier work. The development of fabrication techniques to create surface structures at the micro-and nanoscale using both bottom-up and top-down approaches has led to increased study of complex interfacial phenomena. In the heat transfer community, researchers have been extensively exploring the use of advanced surface structuring techniques to enhance phase-change heat transfer processes. In particular, the field of vapor-to-liquid condensation and especially that of water condensation has experienced a renaissance due to the promise of further optimizing this process at the micro-and nanoscale by exploiting advances in surface engineering developed over the last several decades.

  7. 3-D interactive physically based micro world

    Science.gov (United States)

    Waters, Keith; Wang, SerKuang

    1990-08-01

    This paper describes an approach to synthetic three-dimensional object manipulation using three different haptic I/O devices in a virtual workspace on a graphics superworkstation. The devices involve the operator in unique mode8 of interaction that require positioning a six degree-of-freedom sensor, applying torques to a static ball, or creating interpreted hand ge8tures. With these devices, the user can select, rotate and deposit synthetic virtual objects in the micro world. The micro world is an "artificial reality" in which elementary physical forces of gravity, volume preservation, collision, and external user input may be applied. The techniques developed overcome some of the difficulties experienced with two-dimensional input devices in a three-dimensional space. Furthermore, the ability of the user to continuous modify physical constraints while observing the results in real-time facilitates data interpretation tasks.

  8. MicroRNAs, epigenetics and disease

    DEFF Research Database (Denmark)

    Silahtaroglu, Asli; Stenvang, Jan

    2010-01-01

    Epigenetics is defined as the heritable chances that affect gene expression without changing the DNA sequence. Epigenetic regulation of gene expression can be through different mechanisms such as DNA methylation, histone modifications and nucleosome positioning. MicroRNAs are short RNA molecules...... which do not code for a protein but have a role in post-transcriptional silencing of multiple target genes by binding to their 3' UTRs (untranslated regions). Both epigenetic mechanisms, such as DNA methylation and histone modifications, and the microRNAs are crucial for normal differentiation......, development and maintenance of tissue-specific gene expression. These mechanisms also explain how cells with the same DNA content can differentiate into cells with different functions. Changes in epigenetic processes can lead to changes in gene function, cancer formation and progression, as well as other...

  9. Verification of Tolerance Chains in Micro Manufacturing

    DEFF Research Database (Denmark)

    Gasparin, Stefania

    The aim of this work is to define methodologies for the tolerance verification of injection moulded components with downscaled dimensions. In micro and nano metrology different challenges can be found: lack of calibration artefacts and available ISO standards, problematic uncertainty budget...... on a calibrated standard artefact and to measure both in order to assure an unbroken chain of comparisons. The replica technique reveals to be a fast, cost-effective and reliable method. Regarding the tolerance verification of micro parts and nano-structured surfaces, a systematic approach is discussed based...... on dimensional and geometrical metrology. If the measurements uncertainty is large compared to the tolerance interval, a small conformance zone is left for process variation. Therefore particular attention has to be paid to the instrument capabilities in order to reduce the measurement uncertainty. Different...

  10. MICRO-CHP System for Residential Applications

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Gerstmann

    2009-01-31

    This is the final report of progress under Phase I of a project to develop and commercialize a micro-CHP system for residential applications that provides electrical power, heating, and cooling for the home. This is the first phase of a three-phase effort in which the residential micro-CHP system will be designed (Phase I), developed and tested in the laboratory (Phase II); and further developed and field tested (Phase III). The project team consists of Advanced Mechanical Technology, Inc. (AMTI), responsible for system design and integration; Marathon Engine Systems, Inc. (MES), responsible for design of the engine-generator subsystem; AO Smith, responsible for design of the thermal storage and water heating subsystems; Trane, a business of American Standard Companies, responsible for design of the HVAC subsystem; and AirXchange, Inc., responsible for design of the mechanical ventilation and dehumidification subsystem.

  11. Varactor with integrated micro-discharge source

    Science.gov (United States)

    Elizondo-Decanini, Juan M.; Manginell, Ronald P.; Moorman, Matthew W.

    2016-10-18

    An apparatus that includes a varactor element and an integrated micro-discharge source is disclosed herein. In a general embodiment, the apparatus includes at least one np junction and at least one voltage source that is configured to apply voltage across the np junction. The apparatus further includes an aperture that extends through the np junction. When the voltage is applied across the np junction, gas in the aperture is ionized, forming a plasma, in turn causing a micro-discharge (of light, charge particles, and space charge) to occur. The light (charge particles, and space charge) impinges upon the surface of the np junction exposed in the aperture, thereby altering capacitance of the np junction. When used within an oscillator circuit, the effect of the plasma on the np-junction extends the capacitance changes of the np-junction and extends the oscillator frequency range in ways not possible by a conventional voltage controlled oscillator (VCO).

  12. Varactor with integrated micro-discharge source

    Energy Technology Data Exchange (ETDEWEB)

    Elizondo-Decanini, Juan M.; Manginell, Ronald P.; Moorman, Matthew W.

    2016-10-18

    An apparatus that includes a varactor element and an integrated micro-discharge source is disclosed herein. In a general embodiment, the apparatus includes at least one np junction and at least one voltage source that is configured to apply voltage across the np junction. The apparatus further includes an aperture that extends through the np junction. When the voltage is applied across the np junction, gas in the aperture is ionized, forming a plasma, in turn causing a micro-discharge (of light, charge particles, and space charge) to occur. The light (charge particles, and space charge) impinges upon the surface of the np junction exposed in the aperture, thereby altering capacitance of the np junction. When used within an oscillator circuit, the effect of the plasma on the np-junction extends the capacitance changes of the np-junction and extends the oscillator frequency range in ways not possible by a conventional voltage controlled oscillator (VCO).

  13. Micro electro mechanical system optical switching

    Science.gov (United States)

    Thorson, Kevin J; Stevens, Rick C; Kryzak, Charles J; Leininger, Brian S; Kornrumpf, William P; Forman, Glenn A; Iannotti, Joseph A; Spahn, Olga B; Cowan, William D; Dagel, Daryl J

    2013-12-17

    The present disclosure includes apparatus, system, and method embodiments that provide micro electo mechanical system optical switching and methods of manufacturing switches. For example, one optical switch embodiment includes at least one micro electro mechanical system type pivot mirror structure disposed along a path of an optical signal, the structure having a mirror and an actuator, and the mirror having a pivot axis along a first edge and having a second edge rotatable with respect to the pivot axis, the mirror being capable of and arranged to be actuated to pivot betweeen a position parallel to a plane of an optical signal and a position substantially normal to the plane of the optical signal.

  14. Mini and Micro Propulsion for Medical Swimmers

    Directory of Open Access Journals (Sweden)

    JianFeng

    2014-02-01

    Full Text Available Mini and micro robots, which can swim in an underwater environment, have drawn widespread research interests because of their potential applicability to the medical or biological fields, including delivery and transportation of bio-materials and drugs, bio-sensing, and bio-surgery. This paper reviews the recent ideas and developments of these types of self-propelling devices, ranging from the millimeter scale down to the micro and even the nano scale. Specifically, this review article makes an emphasis on various propulsion principles, including methods of utilizing smart actuators, external magnetic/electric/acoustic fields, bacteria, chemical reactions, etc. In addition, we compare the propelling speed range, directional control schemes, and advantages of the above principles.

  15. Sequential micro and ultrafiltration of distillery wastewater

    Directory of Open Access Journals (Sweden)

    Vasić Vesna M.

    2015-01-01

    Full Text Available Water reuse and recycling, wastewater treatment, drinking water production and environmental protection are the key challenges for the future of our planet. Membrane separation technologies for the removal of all suspended solids and a fraction of dissolved solids from wastewaters, are becoming more and more promising. Also, these processes are playing a major role in wastewater purification systems because of their high potential for recovery of water from many industrial wastewaters. The aim of this work was to evaluate the application of micro and ultrafiltration for distillery wastewater purification in order to produce water suitable for reuse in the bioethanol industry. The results of the analyses of the permeate obtained after micro and ultrafiltration showed that the content of pollutants in distillery wastewater was significantly reduced. The removal efficiency for chemical oxygen demand, dry matter and total nitrogen was 90%, 99.2% and 99.9%, respectively. Suspended solids were completely removed from the stillage.

  16. Green nanoparticle production using micro reactor technology

    Science.gov (United States)

    Kück, A.; Steinfeldt, M.; Prenzel, K.; Swiderek, P.; Gleich, A. v.; Thöming, J.

    2011-07-01

    The importance and potential of nanoparticles in daily life as well as in various industrial processes is becoming more predominant. Specifically, silver nanoparticles are increasingly applied, e.g. in clothes and wipes, due to their antibacterial properties. For applications in liquid phase it is advantageous to produce the nanoparticles directly in suspension. This article describes a green production of silver nanoparticles using micro reactor technology considering principles of green chemistry. The aim is to reveal the potential and constraints of this approach and to show, how economic and environmental costs vary depending on process conditions. For this purpose our research compares the proposed process with water-based batch synthesis and demonstrates improvements in terms of product quality. Because of the lower energy consumption and lower demand of cleaning agents, micro reactor is the best ecological choice.

  17. Micro electro mechanical system optical switching

    Energy Technology Data Exchange (ETDEWEB)

    Thorson, Kevin J; Stevens, Rick C; Kryzak, Charles J; Leininger, Brian S; Kornrumpf, William P; Forman, Glenn A; Iannotti, Joseph A; Spahn, Olga B; Cowan, William D; Dagel, Daryl J

    2013-12-17

    The present disclosure includes apparatus, system, and method embodiments that provide micro electo mechanical system optical switching and methods of manufacturing switches. For example, one optical switch embodiment includes at least one micro electro mechanical system type pivot mirror structure disposed along a path of an optical signal, the structure having a mirror and an actuator, and the mirror having a pivot axis along a first edge and having a second edge rotatable with respect to the pivot axis, the mirror being capable of and arranged to be actuated to pivot betweeen a position parallel to a plane of an optical signal and a position substantially normal to the plane of the optical signal.

  18. Payment mechanisms for micro-generation

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, W.; Andrews, S.

    2002-07-01

    The Department of Trade and Industry commissioned a study into payment options for the increasing number of micro-generators (in domestic dwellings and where the generating capacity is not more than 5kW i.e. essentially micro-CHP and photovoltaics) supplying power for the national distribution network. It is shown that small generators will impact on all aspects of industry and connection will need to be simplified. The network will call for a more actively managed regime. Metering will need to be more sophisticated and agreement reached on how costs should be allocated when demand is low and surplus electricity is exported to the system. Three options were considered to be viable.

  19. Biological stoichiometry in tumor micro-environments.

    Directory of Open Access Journals (Sweden)

    Irina Kareva

    Full Text Available Tumors can be viewed as evolving ecological systems, in which heterogeneous populations of cancer cells compete with each other and somatic cells for space and nutrients within the ecosystem of the human body. According to the growth rate hypothesis (GRH, increased phosphorus availability in an ecosystem, such as the tumor micro-environment, may promote selection within the tumor for a more proliferative and thus potentially more malignant phenotype. The applicability of the GRH to tumor growth is evaluated using a mathematical model, which suggests that limiting phosphorus availability might promote intercellular competition within a tumor, and thereby delay disease progression. It is also shown that a tumor can respond differently to changes in its micro-environment depending on the initial distribution of clones within the tumor, regardless of its initial size. This suggests that composition of the tumor as a whole needs to be evaluated in order to maximize the efficacy of therapy.

  20. Biological stoichiometry in tumor micro-environments.

    Science.gov (United States)

    Kareva, Irina

    2013-01-01

    Tumors can be viewed as evolving ecological systems, in which heterogeneous populations of cancer cells compete with each other and somatic cells for space and nutrients within the ecosystem of the human body. According to the growth rate hypothesis (GRH), increased phosphorus availability in an ecosystem, such as the tumor micro-environment, may promote selection within the tumor for a more proliferative and thus potentially more malignant phenotype. The applicability of the GRH to tumor growth is evaluated using a mathematical model, which suggests that limiting phosphorus availability might promote intercellular competition within a tumor, and thereby delay disease progression. It is also shown that a tumor can respond differently to changes in its micro-environment depending on the initial distribution of clones within the tumor, regardless of its initial size. This suggests that composition of the tumor as a whole needs to be evaluated in order to maximize the efficacy of therapy.

  1. Research of micro-EDM and its applications

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A Micro Electrical Discharge Machining (MEDM) equipment was developed in this paper, on which the CNC interpolation for 3-axis linkage movement could be realized easily. By this micro-EDM equipment, the fabrication process of microelectrode, micro hole, silicon wafer and complex microstructure was discussed. The process rules of machining efficiency and the relative electrode wear rate as well as the machining mechanism and performance of silicon micro-EDM were also researched. Machining experiments showed that the microelectrode diameter as small as 6 μm and the micro hole with minimum size of 10 μm could be obtained steadily,and the maximum aspect ratios of microelectrode and micro hole were over 25 and 10 respectively. And silicon micro-EDM experiments showed that the micro beam with the aspect ratios over 15 could be obtained easily.And a micro beam with minimum size of 23 μm width on a silicon wafer with 420 μm thickness was achieved.At last, the microstructure machining technology for micro-EDM was also discussed. And a micro-facial sculpture with free space curved surface and size of 1 mm ×0.3 mm ×0.18 mm was also machined successfully.

  2. High-speed micro-electro-discharge machining.

    Energy Technology Data Exchange (ETDEWEB)

    Chandrasekar, Srinivasan Dr. (.School of Industrial Engineering, West Lafayette, IN); Moylan, Shawn P. (School of Industrial Engineering, West Lafayette, IN); Benavides, Gilbert Lawrence

    2005-09-01

    When two electrodes are in close proximity in a dielectric liquid, application of a voltage pulse can produce a spark discharge between them, resulting in a small amount of material removal from both electrodes. Pulsed application of the voltage at discharge energies in the range of micro-Joules results in the continuous material removal process known as micro-electro-discharge machining (micro-EDM). Spark erosion by micro-EDM provides significant opportunities for producing small features and micro-components such as nozzle holes, slots, shafts and gears in virtually any conductive material. If the speed and precision of micro-EDM processes can be significantly enhanced, then they have the potential to be used for a wide variety of micro-machining applications including fabrication of microelectromechanical system (MEMS) components. Toward this end, a better understanding of the impacts the various machining parameters have on material removal has been established through a single discharge study of micro-EDM and a parametric study of small hole making by micro-EDM. The main avenues for improving the speed and efficiency of the micro-EDM process are in the areas of more controlled pulse generation in the power supply and more controlled positioning of the tool electrode during the machining process. Further investigation of the micro-EDM process in three dimensions leads to important design rules, specifically the smallest feature size attainable by the process.

  3. MicroRNA expression profiling and DNA methylation signature for deregulated microRNA in cutaneous T-cell lymphoma.

    Science.gov (United States)

    Sandoval, Juan; Díaz-Lagares, Angel; Salgado, Rocío; Servitje, Octavio; Climent, Fina; Ortiz-Romero, Pablo L; Pérez-Ferriols, Amparo; Garcia-Muret, Maria P; Estrach, Teresa; Garcia, Mar; Nonell, Lara; Esteller, Manel; Pujol, Ramon M; Espinet, Blanca; Gallardo, Fernando

    2015-04-01

    MicroRNAs usually regulate gene expression negatively, and aberrant expression has been involved in the development of several types of cancers. Microarray profiling of microRNA expression was performed to define a microRNA signature in a series of mycosis fungoides tumor stage (MFt, n=21) and CD30+ primary cutaneous anaplastic large cell lymphoma (CD30+ cALCL, n=11) samples in comparison with inflammatory dermatoses (ID, n=5). Supervised clustering confirmed a distinctive microRNA profile for cutaneous T-cell lymphoma (CTCL) with respect to ID. A 40 microRNA signature was found in MFt including upregulated onco-microRNAs (miR-146a, miR-142-3p/5p, miR-21, miR-181a/b, and miR-155) and downregulated tumor-suppressor microRNAs (miR-200ab/429 cluster, miR-10b, miR-193b, miR-141/200c, and miR-23b/27b). Regarding CD30+ cALCL, 39 differentially expressed microRNAs were identified. Particularly, overexpression of miR-155, miR-21, or miR-142-3p/5p and downregulation of the miR-141/200c clusters were observed. DNA methylation in microRNA gene promoters, as expression regulatory mechanism for deregulated microRNAs, was analyzed using Infinium 450K array and approximately one-third of the differentially expressed microRNAs showed significant DNA methylation differences. Two different microRNA methylation signatures for MFt and CD30+ cALCL were found. Correlation analysis showed an inverse relationship for microRNA promoter methylation and microRNA expression. These results reveal a subgroup-specific epigenetically regulated microRNA signatures for MFt and CD30+ cALCL patients.

  4. Notes on matrix and micro strings

    Science.gov (United States)

    Dijkgraaf, Robbert; Verlinde, E.; Verlinde, H.

    1998-11-01

    We review some recent developments in the study of M-theory compactifications via Matrix theory. In particular we highlight the appearance of IIA strings and their interactions, and explain the unifying role of the M-theory five-brane for describing the spectrum of the T5 compactification and its duality symmetries. The 5+1-dimensional micro-string theory that lives on the fivebrane world-volume takes a central place in this presentation.

  5. Notes on Matrix and Micro Strings

    CERN Document Server

    Dijkgraaf, R; Verlinde, Herman L

    1998-01-01

    We review some recent developments in the study of M-theory compactifications via Matrix theory. In particular we highlight the appearance of IIA strings and their interactions, and explain the unifying role of the M-theory five-brane for describing the spectrum of the T^5 compactification and its duality symmetries. The 5+1-dimensional micro-string theory that lives on the fivebrane world-volume takes a central place in this presentation.

  6. MicroRNA signatures in liver diseases

    OpenAIRE

    Chen, Xian-Ming

    2009-01-01

    MicroRNAs (miRNAs) are an emerging class of highly conserved non-coding small RNAs that regulate gene expression at the post-transcriptional level. It is now clear that miRNAs can potentially regulate every aspect of cellular activity, including differentiation and development, metabolism, proliferation, apoptotic cell death, viral infection and tumorigenesis. Recent studies provide clear evidence that miRNAs are abundant in the liver and modulate a diverse spectrum of liver functions. Deregu...

  7. Micro and smart devices and systems

    CERN Document Server

    Ananthasuresh, G; Pratap, Rudra; Krupanidhi, S

    2014-01-01

    The book presents cutting-edge research in the emerging fields of micro, nano, and smart devices and systems from experts working in these fields over the last decade. Most of the contributors have built devices or systems or developed processes or algorithms in these areas. The book is a unique collection of chapters from different areas with a common theme and is immensely useful to academic researchers and practitioners in the industry who work in this field.

  8. Geometrical characterization of micro end milling tools

    DEFF Research Database (Denmark)

    Borsetto, Francesca; Bariani, Paolo; Bissacco, Giuliano

    2005-01-01

    Performance of the milling process is directly affected by the accuracy of tool geometry. Development of methods suitable for dimensional characterization of such tools, with low measurement uncertainties is therefore of relevance. The present article focuses on the geometrical characterization o...... of a flat micro end milling tool with a nominal mill diameter of 200 microns. An experimental investigation was carried out involving two different non-contact systems...

  9. Geometrical characterization of micro end milling tools

    DEFF Research Database (Denmark)

    Borsetto, Francesca; Bariani, Paolo; Bissacco, Giuliano;

    2005-01-01

    Performance of the milling process is directly affected by the accuracy of tool geometry. Development of methods suitable for dimensional characterization of such tools, with low measurement uncertainties is therefore of relevance. The present article focuses on the geometrical characterization...... of a flat micro end milling tool with a nominal mill diameter of 200 microns. An experimental investigation was carried out involving two different non-contact systems...

  10. Mass Spectrometer for Airborne Micro-Organisms

    Science.gov (United States)

    Sinha, M. P.; Friedlander, S. K.

    1986-01-01

    Bacteria and other micro-organisms identified continously with aid of new technique for producing samples for mass spectrometer. Technique generates aerosol of organisms and feeds to spectrometer. Given species of organism produces characteristic set of peaks in mass spectrum and thereby identified. Technique useful for monitoring bacterial makeup in environmental studies and in places where cleanliness is essential, such as hospital operating rooms, breweries, and pharmaceutical plants.

  11. Space project IONOSAT- MICRO - goals and realization

    Science.gov (United States)

    Korepanov, Valery; Lizunov, Georgii; Fedorov, Oleg

    2013-04-01

    The IONOSAT-MICRO project is a first stage of IONOSAT program devoted to the multi-point global monitoring of dynamic processes in the ionosphere. The IONOSAT program is planned to be realized in 2015-2020 with the help of three satellites at coordinated low Earth orbits (LEO). IONOSAT-MICRO is the forerunner project scheduled for launch in 2014 at sun-synchronous orbit with the aim to test the IONOSAT mission scientific postulates and preliminary collection of related space data. The main goal of the IONOSAT-MICRO project is the systematic study of the dynamic response of the ionosphere to the influence "from above" (sun, geomagnetic activity) and "from below" (powerful meteorological, seismic and anthropogenic impacts). More in details, the study of following formations in the ionosphere is foreseen: - Space-temporal structure and global distribution of inhomogeneities in neutral atmosphere and ionosphere; - Global structure and dynamics of quasi-stationary electric currents, electric and magnetic fields; - Wave structures and turbulences at different spatial and temporal scales. To realize such a research, the scientific payload of the MICROSAT spacecraft will provide the measurements of following parameters: - Neutral gas and plasma parameters - concentration, temperature; - DC-ELF-VLF electromagnetic field vectors and ELF-VLF plasma current fluctuations; - Total electron content (TEC); - Spectral content of plasma oscillations. Synchronous experiments with ground support facilities - both active and passive ones - are also foreseen. The IONOSAT-MICRO project will be realized onboard of MICROSAT microsatellite platform, manufactured by Yuzhnoye Design Office with new experimental models of ammonia propulsion system, battery, solar arrays and panels with thermal control coating, the in-flight tests of which are also planned in frames of the project. The composition of the scientific equipment developed by the international team of participants and sensors

  12. Micro and macro factors affecting childbearing aspirations.

    Science.gov (United States)

    He, Y

    1992-01-01

    The conclusion of the discussion of factors affecting childbearing aspirations is that both a micro and a macro perspective must be included in an empirical analysis which would be useful for policy decisions. Micro factors tend to the economic function of the family, the economic value of children, cost of labor training, women's occupation, social security, household consumption, and education level. Attention to micro factors is important in the link between individual interests and state family planning (FP) policy. Macro factors tend to be ignored, but also impact on childbearing decisions. Macro factors are economic conditions, social and political factors, culture, and environmental factors such as ecology, natural resources, employment, economic development, and education. Macro factors affect the population as a whole and indirectly impact on individuals and the family. China's achievements in FP policy have been identified as a reduction of 200 million people, a shift in the population reproduction cycle downwards, increased standard of living, reduction in the burden of working people, and stabilization of macro factors. Successful policy should not rely on forced implementation. The past and present policies were successful not because of forced implementation, but because of awareness of macro and micro factors and voluntary use of FP. The voluntary nature of acceptance of FP suggests support for the FP policies. The current focus is on rural areas, and farmers in particular who are only aware of their needs and may feel state policy may interfere with their own interests. Implementation of FP among the rural population would be enhanced with an emphasis on their concerns such as social security in old age, the practical issues of having only daughters, and educational status. Educational campaigns promoting awareness of population pressure are needed and will benefit all the people. Social democratic doctrines can be introduced only from the outside

  13. Micro Products - Product Development and Design

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard

    2003-01-01

    Innovation within the field of micro and nano technology is to a great extent characterized by cross-disciplinary skills. The traditional disciplines like e.g. physics, biology, medicine and engineering are united in a common development process that can only take place in the presence of multi...... that make it possible to produce the products at a reasonable price and in large numbers is growing....

  14. Micro-Texture Synthesis by Phase Randomization

    Directory of Open Access Journals (Sweden)

    Bruno Galerne

    2011-09-01

    Full Text Available This contribution is concerned with texture synthesis by example, the process of generating new texture images from a given sample. The Random Phase Noise algorithm presented here synthesizes a texture from an original image by simply randomizing its Fourier phase. It is able to reproduce textures which are characterized by their Fourier modulus, namely the random phase textures (or micro-textures.

  15. Experimental and numerical study of micro deep drawing

    Directory of Open Access Journals (Sweden)

    Luo Liang

    2015-01-01

    Full Text Available Micro forming is a key technology for an industrial miniaturisation trend, and micro deep drawing (MDD is a typical micro forming method. It has great advantages comparing to other micro manufacturing methods, such as net forming ability, mass production potential, high product quality and complex 3D metal products fabrication capacity. Meanwhile, it is facing difficulties, for example the so-called size effects, once scaled down to micro scale. To investigate and to solve the problems in MDD, a combined micro blanking-drawing machine is employed and an explicit-implicit micro deep drawing model with a voronoi blank model is developed. Through heat treatment different grain sizes can be obtained, which affect material's properties and, consequently, the drawing process parameters, as well as produced cups' quality. Further, a voronoi model can provide detailed material information in simulation, and numerical simulation results are in accordance with experimental results.

  16. Dynamics of micro-bubble sonication inside a phantom vessel

    KAUST Repository

    Qamar, Adnan

    2013-01-10

    A model for sonicated micro-bubble oscillations inside a phantom vessel is proposed. The model is not a variant of conventional Rayleigh-Plesset equation and is obtained from reduced Navier-Stokes equations. The model relates the micro-bubble oscillation dynamics with geometric and acoustic parameters in a consistent manner. It predicts micro-bubble oscillation dynamics as well as micro-bubble fragmentation when compared to the experimental data. For large micro-bubble radius to vessel diameter ratios, predictions are damped, suggesting breakdown of inherent modeling assumptions for these cases. Micro-bubble response with acoustic parameters is consistent with experiments and provides physical insight to the micro-bubble oscillation dynamics.

  17. Control wetting state transition by micro-rod geometry

    Science.gov (United States)

    He, Yang; Jiang, Chengyu; Wang, Shengkun; Yin, Hengxu; Yuan, Weizheng

    2013-11-01

    Understanding the effect of micro-structure geometry on wetting state transition is important to design and control surface wettability. Micro-rod model was proposed and the relationship between micro-rod geometry and wetting state was investigated in the paper taking into account only the surface roughness and neglecting the chemistry interaction. Micro-rods with different geometric parameters were fabricated using micro-fabrication technology. Their contact angles were measured and compared with theoretical ones. The experimental results indicated that increasing the height and decreasing the space of micro-rod may result in Cassie wetting state, while decreasing the height and increasing the space may result in Wenzel wetting state. A suspended wetting state model due to scallops was proposed. The wetting state transition was interpreted by intruding height, de-pinning and sag mechanism. It may offer a facile way to control the surface wetting state transition by changing the geometry of micro-rod.

  18. Novel role of microRNAs in prostate cancer

    Institute of Scientific and Technical Information of China (English)

    YU Jun-jie; XIA Shu-jie

    2013-01-01

    Objective To discuss the novel biomarkers of microRNAs in prostate cancer.Data sources The literatures about microRNAs and prostate cancer cited in this review were obtained mainly from Pubmed published in English from 2004 to 2012.Study selection Original articles regarding the novel role of microRNAs in prostate cancer were selected.Results MicroRNAs play an important role in prostate cancer such as cell differentiation,proliferation,apoptosis,and invasion.Especially microRNAs correlate with prostate cancer cell epithelial-mesenchymal transition (EMT),cancer stem cells (CSCs),drug sensitivity,cancer microenvironment,energy metabolism,androgen independence transformation,and diagnosis prediction.Conclusions MicroRNAs are involved in various aspects of prostate cancer biology.The role of microRNA in the initiation and development of prostate cancer deserves further study.

  19. Application of micro-seismic monitoring technology in mining engineering

    Institute of Scientific and Technical Information of China (English)

    Sun Jian; Wang Lianguo; Hou Huaqiang

    2012-01-01

    Micro-seismic phenomena,occurring when rock masses are subjected to forces and failures,allow the determination of their unstable states and failure zones by analyzing micro-seismic signals.We first present the principles of micro-seismic monitoring and location,as well as an underground explosion-proof micro-seismic monitoring system.Given a practical engineering application,we describe the application of micro-seismic monitoring technology in determining the height of a "two-zone" overburden,i.e.,a caving zone and a fracture zone,the width of a coal-pillar section and the depth of failure of a floor.The workfaces monitored accomplished safe and highly efficient mining based on our micro-seismic monitoring results and provide direct proof of the reliability and validity of micro-seismic monitoring technology.

  20. The Intelligent Properties of Micro-reactors for Preparating Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Gang WEI; Hai Yan HUANG; Rong Chun XIONG

    2003-01-01

    TiO2 nanoparticles were synthesized by using micro-reactors. The shape and size of the nanoparticles produced from the original micro-reactors and the five times recycled micro-reactors mother liquor were investigated on transmission electron microscopy (TEM) by using the original sample, freeze prepared sample, and dyeing treated sample, respectively. UV-VIS spectrometry was used to study the growth process of TiO2 nanoparticles in main reactors. The results showed that micro-reactors with nanometer magnitude had spherical or oval structures, and could restore to their original structure after they were destroyed. The products prepared in the original micro-reactors were similar to that in the micro-reactors recycled for many times, suggesting that the micro-reactors had memory function.

  1. Gendering dynamic capabilities in micro firms

    Directory of Open Access Journals (Sweden)

    Yevgen Bogodistov

    2017-05-01

    Full Text Available Gender issues are well-researched in the general management literature, particular in studies on new ventures. Unfortunately, gender issues have been largely ignored in the dynamic capabilities litera­ture. We address this gap by analyzing the effects of gender diversity on dynamic capabilities among micro firms. We consider the gender of managers and personnel in 124 Ukrainian tourism micro firms. We examine how a manager’s gender affects the firm’s sensing capacities and investigate how it moderates team gender diversity’s impact on sensing capacities. We also investigate how person­nel composition impacts seizing and reconfiguration capacities. We find that female managers have several shortcomings concerning a firm’s sensing capacity but that personnel gender diversity increa­ses this capacity. Team gender diversity has positive effects on a firm’s seizing and reconfiguration abilities. Our study advances research on gender diversity and its impact on firm capabilities and illustrates its relevance for staffing practices in micro firms.

  2. Injection molding of micro patterned PMMA plate

    Institute of Scientific and Technical Information of China (English)

    Yeong-Eun YOO; Tae-Hoon KIM; Tae-Jin JE; Doo-Sun CHOI; Chang-Wan KIM; Sun-Kyung KIM

    2011-01-01

    A plastic plate with surface micro features was injection molded to investigate the effect of pressure rise of melt on the replication of the micro structures. Prism pattern, which is used in many optical applications, was selected as a model pattern. The prism pattern is 50 μm in pitch and 108° in the vertical angle. The overall size of the plate was 335 mm×213 mm and the thickness of the plate varied linearly from 2.6 mm to 0.7 mm. The prism pattern was firstly machined on the nickel plated core block using micro diamond tool and this machined pattern core was installed in a mold for injection molding of prism patterned plate. Polymethyl methacrylate (PMMA) was used as a molding material. The pressure and temperature of the melt in the cavity were measured at different positions in the cavity and the replication of the pattern was also measured at the same positions. The results show that the pressure or temperature profile through the process depends on the shape and the size of the plate. The replication is affected by the temperature and pressure profiles at the early stage of filling, which is right after the melt reaches the position to be measured.

  3. Hierarchical Design Method for Micro Device

    Directory of Open Access Journals (Sweden)

    Zheng Liu

    2013-05-01

    Full Text Available Traditional mask-beginning design flow of micro device is unintuitive and fussy for designers. A hierarchical design method and involved key technologies for features mapping procedure are presented. With the feature-based design framework, the model of micro device is organized by various features in different designing stages, which can be converted into each other based on the mapping rules. The feature technology is the foundation of the three-level design flow that provides a more efficient design way. In system level, functional features provide the top level of schematic and functional description. After the functional mapping procedure, on the other hand, parametric design features construct the 3D model of micro device in device level, which is based on Hybird Model representation. By means of constraint features, the corresponding revision rules are applied to the rough model to optimize the original structure. As a result, the model reconstruction algorithm makes benefit for the model revision and constraint features mapping process. Moreover, the formulating description of manufacturing features derivation provides the automatic way for model conversion.

  4. Investigation of impact materials from the Barringer Meteor Crater by micro-XANES and micro-PIXE techniques

    Energy Technology Data Exchange (ETDEWEB)

    Szikszai, Z. [Institute of Nuclear Research of the Hungarian Academy of Sciences, MTA ATOMKI, H-4001 Debrecen, P.O. Box 51 (Hungary)], E-mail: szikszai@atomki.hu; Uzonyi, I.; Kiss, A.Z.; Sziki, G.A. [Institute of Nuclear Research of the Hungarian Academy of Sciences, MTA ATOMKI, H-4001 Debrecen, P.O. Box 51 (Hungary); Vantelon, D. [Synchrotron SOLEIL, L' Orme des Merisiers, St. Aubin-BP 48, F-91192 Gif sur Yvette Cedex (France); Rozsa, P. [Department of Mineralogy and Geology, University of Debrecen, H-4010 Debrecen, Egyetem ter 1 (Hungary)

    2009-06-15

    Impact materials from the Barringer Meteor Crater were examined by combined micro-X-ray absorption near edge structure (micro-XANES) and micro-particle induced X-ray emission (micro-PIXE) methods. Efforts were focussed on the complex characterization of their iron-rich inclusions. The lateral distribution of elements as well as the oxidation state of iron was determined. The study demonstrates the capabilities of chemical speciation screening based on energy selective micro-XRF maps in geology. With the help of this method zero-valent (metallic) and three-valent iron were excluded in the studied specimens without performing XANES in every pixel.

  5. Micro PIXE and microNRA: associated tools for materials characterization

    Energy Technology Data Exchange (ETDEWEB)

    Boufleur, L.A.; Dias, J.F.; Amaral, L. [Universidade Federal do Rio Grande do Sul (UFRGS/IF/LLI), Porto Alegre, RS (Brazil). Inst. de Fisica. Lab. de Implantacao Ionica

    2013-07-01

    Full text: Ion beam based analytical techniques are widely used for modification, characterization and analysis of materials. One of the motivations for the continued development and application of these techniques part of its high sensitivity for determining and quantifying trace elements in the order of parts per million (ppm), and create images of their distributions and depth profiles. The elemental characterization of homogeneous samples is performed in, general, by combining two complementary techniques: PIXE (Particle Induced X-ray Emission) and RBS (Rutherford Backscattering) with stationary beams of the order of mm{sup 2}. However, when there are structures in the sample surface and differences in its elemental distribution, we should use the scanning microbeam system, where it reduces the size of the beam to the order μm2. The association between the techniques remain the same, Micro PIXE provides the spatial distribution of elements with Z> 12 and micro RBS allows the study of multilayer solids, with good selectivity for thin layers of heavy elements on light elements substrates. Despite having lower cross sections, the technique of nuclear reaction analysis (NRA- Nuclear Reaction Analysis) can also be used in the microbeam system. The positive point is that through NRA is possible to determine light elements and their isotopes on any substrate. This study shows the possibility of associating micro PIXE and micro RNA for elemental characterization of materials. As an example, we present the elemental characterization of a human hair. Through the micro RNA was possible to determine the presence of carbon, while micro PIXE showed the presence of elements such as: S, K, Ca and Zn in agreement with other studies reported [1]. Samples were irradiated at the Laboratorio de Implantacao Ionica (IF-UFRGS), utilizing the 3MV tandem accelerator. Proton beams with energy of 1,75 MeV were selected for analysis of particular micro regions of the hair sample with

  6. Advance research on microRNA-221,microRNA-222 and malignant tumor%microRNA-221和microRNA-222与恶性肿瘤的研究进展

    Institute of Scientific and Technical Information of China (English)

    张春智; 康春生; 浦佩玉

    2009-01-01

    It has become clear that particular microRNAs(miRNAs) function either as tumor suppres-sors or oncogenes, whose loss or overexpression, respectively, has diagnostic and prognostic significance.Mi-croRNA-221 and microRNA-222 are a cluster microRNAs of oncogenes.They are overexpressed in some malig-nant tumors, including glioblstoma, prostate carcinoma, papillary thyroid carcinoma, and so on.By regulating particular target mRNAs, microRNA-221 and microRNA-222 perform pro- oneogenie role.p27kip1 and p57kip2 are target genes of microRNA-221 and mieroRNA-222.MicroRNA-221 and microRNA-222 promote oncogensis and tumor grow by down-regulating p27kip1 and p57kip2 expression.%微RNA(micmRNA)-221和microRNA-222是成簇的microRNA,在恶性肿瘤中起促癌作用,在胶质母细胞瘤、前列腺癌、乳头状甲状腺癌等恶性肿瘤中高表达.microRNA-221和microRNA-222通过调控其特定的靶基因行使促癌作用.在所有预测的靶基因中,p27kip1和p57kip2是已被验证的靶基因,microRNA-221和microRNA-222通过下调p27kip1和p57kip2的表达来促进肿瘤的形成和生长.

  7. 甲状腺癌相关microRNA%Thyroid carcinoma related microRNA

    Institute of Scientific and Technical Information of China (English)

    杨靖; 钟警

    2012-01-01

    Carcinoma of the thyroid gland is the most frequent malignancy of the endocrine system, whereby papillary thyroid carcinoma and follicular thyroid carcinoma are the most common of the 4 pathological types. The mechanisms underlying the development of these neoplasias are still far from being completely elucidated. In recent years, several studies have found that microRNA expression differences exist in different pathological types of thyroid carcinoma, and that microRNAs may play an important role in the occurrence and development of thyroid carcinoma. Here we review the issue of microRNA as related to thyroid carcinoma.%甲状腺癌是内分泌系统最常见的恶性肿瘤,包括4种病理类型,其中以乳头状癌及滤泡状癌最为常见.甲状腺癌的发病机制目前尚未阐明.近年来,研究发现在不同甲状腺癌病理类型中存在microRNA表达差异,microRNA可能在甲状腺癌的发生、发展中具有重要作用.

  8. The role of micro-NRA and micro-PIXE in carbon mapping of organic tissues

    Energy Technology Data Exchange (ETDEWEB)

    Niekraszewicz, L.A.B. [Ion Implantation Laboratory, Institute of Physics, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, P.O. Box 15051, CEP 91501-970 Porto Alegre, RS (Brazil); Graduate Program on Materials Science, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CEP 91540-000 Porto Alegre, RS (Brazil); Souza, C.T. de; Stori, E.M.; Jobim, P.F.C. [Ion Implantation Laboratory, Institute of Physics, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, P.O. Box 15051, CEP 91501-970 Porto Alegre, RS (Brazil); Amaral, L. [Ion Implantation Laboratory, Institute of Physics, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, P.O. Box 15051, CEP 91501-970 Porto Alegre, RS (Brazil); Graduate Program on Materials Science, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CEP 91540-000 Porto Alegre, RS (Brazil); Dias, J.F., E-mail: jfdias@if.ufrgs.br [Ion Implantation Laboratory, Institute of Physics, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, P.O. Box 15051, CEP 91501-970 Porto Alegre, RS (Brazil); Graduate Program on Materials Science, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CEP 91540-000 Porto Alegre, RS (Brazil)

    2015-04-01

    This study reports the work developed in the Ion Implantation Laboratory (Porto Alegre, RS, Brazil) in order to implement the micro-NRA technique for the study of light elements in organic tissues. In particular, the work was focused on nuclear reactions employing protons and alphas with carbon. The (p,p) resonances at 0.475 and 1.734 were investigated. The (α,α) resonance at 4.265 MeV was studied as well. The results indicate that the yields for the 0.475 and 1.734 MeV resonances are similar. Elemental maps of different structures obtained with the micro-NRA technique using the 1.734 MeV resonance were compared with those obtained with micro-PIXE employing a SDD detector equipped with an ultra-thin window. The results show that the use of micro-NRA for carbon at 1.734 MeV resonance provides good results in some cases at the expense of longer beam times. On the other hand, micro-PIXE provides enhanced yields but is limited to surface analysis since soft X-rays are greatly attenuated by matter.

  9. microRNAs and psoriasis%microRNA与银屑病

    Institute of Scientific and Technical Information of China (English)

    郝勇; 李斌; 石继海

    2009-01-01

    miemRNA是近年来发现的一组非编码单链小分子RNA,其对基因表达进行转录后调控,在许多疾病中都有异常表达,是疾病发生的总"开关".与正常皮肤组织和其他炎症性皮肤病(如特应性皮炎)比较,银屑病皮损有特异性microRNA表达异常.研究这些特异性microRNA在银屑病中的作用,对银屑病发病机制的阐明具有一定意义.%microRNAs ale recently discovered,small,non-coding,single-strand RNAs,which can regulate gene expression posttranscriptionally.They are abnormally expressed in many diseases and act as the total"switch"of disease development.Psoriatic lesions have an abnormal microRNA expression profile when compared with normal skin and other chronic inflammatory skin diseases,such as atopic eczema.To investigate the role of specific microRNAs in psoriasis may benefit the elucidation of pathogenesis as well as the development of target gene therapy of psoriasis.

  10. Micro-IL and micro-PIXE studies of rich diamond meteorites at Legnaro nuclear microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Lo Giudice, A. E-mail: logiudice@ph.unito.it; Pratesi, G.; Olivero, P.; Paolini, C.; Vittone, E.; Manfredotti, C.; Sammiceli, F.; Rigato, V

    2003-09-01

    A combination of micro-ionoluminescence (micro-IL) and micro-PIXE was used to characterize diamond grains inside a type of meteorites known as ureilites. Ureilites are a group of achondrites unique in containing relatively large amounts of carbon occurring as diamond, graphite or lonsdaleite. A shock origin for ureilitic diamonds has been widely accepted though an exact knowledge of the conditions during high-pressure graphite conversion is not yet achieved. Micro-IL is a very powerful technique for material investigation and particularly for diamond analysis. Using this technique we were able to identify the occurrence of the diamond phase inside carbon meteoritic inclusions and to perform micro-PIXE analysis on single diamond grains. In fact, IL in low nitrogen content diamonds is dominated by A-band emission (centered at about 2.9 eV) and so, considering only IL monochromatic map at such a spectral band, it was possible to identify them. By making measurements directly on the meteorites, contamination during chemical extraction processes was avoided and it was possible to study not only the diamond phase, but also its distribution inside carbon inclusions.

  11. Prediction of viral microRNA precursors based on human microRNA precursor sequence and structural features.

    Science.gov (United States)

    Kumar, Shiva; Ansari, Faraz A; Scaria, Vinod

    2009-08-20

    MicroRNAs (small approximately 22 nucleotide long non-coding endogenous RNAs) have recently attracted immense attention as critical regulators of gene expression in multi-cellular eukaryotes, especially in humans. Recent studies have proved that viruses also express microRNAs, which are thought to contribute to the intricate mechanisms of host-pathogen interactions. Computational predictions have greatly accelerated the discovery of microRNAs. However, most of these widely used tools are dependent on structural features and sequence conservation which limits their use in discovering novel virus expressed microRNAs and non-conserved eukaryotic microRNAs. In this work an efficient prediction method is developed based on the hypothesis that sequence and structure features which discriminate between host microRNA precursor hairpins and pseudo microRNAs are shared by viral microRNA as they depend on host machinery for the processing of microRNA precursors. The proposed method has been found to be more efficient than recently reported ab-initio methods for predicting viral microRNAs and microRNAs expressed by mammals.

  12. Micro Climate Simulation in new Town 'Hashtgerd'

    Science.gov (United States)

    Sodoudi, S.; Langer, I.; Cubasch, U.

    2012-04-01

    One of the objectives of climatological part of project Young Cities 'Developing Energy-Efficient Urban Fabric in the Tehran-Karaj Region' is to simulate the micro climate (with 1m resolution) in 35ha of new town Hashtgerd, which is located 65 km far from mega city Tehran. The Project aims are developing, implementing and evaluating building and planning schemes and technologies which allow to plan and build sustainable, energy-efficient and climate sensible form mass housing settlements in arid and semi-arid regions ("energy-efficient fabric"). Climate sensitive form also means designing and planning for climate change and its related effects for Hashtgerd New Town. By configuration of buildings and open spaces according to solar radiation, wind and vegetation, climate sensitive urban form can create outdoor thermal comfort. To simulate the climate on small spatial scales, the micro climate model Envi-met has been used to simulate the micro climate in 35 ha. The Eulerian model ENVI-met is a micro-scale climate model which gives information about the influence of architecture and buildings as well as vegetation and green area on the micro climate up to 1 m resolution. Envi-met has been run with information from topography, downscaled climate data with neuro-fuzzy method, meteorological measurements, building height and different vegetation variants (low and high number of trees) Through the optimal Urban Design and Planning for the 35ha area the microclimate results shows, that with vegetation the microclimate in streets will be change: • 2 m temperature is decreased by about 2 K • relative humidity increase by about 10 % • soil temperature is decreased by about 3 K • wind speed is decreased by about 60% The style of buildings allows free movement of air, which is of high importance for fresh air supply. The increase of inbuilt areas in 35 ha reduces the heat island effect through cooling caused by vegetation and increase of air humidity which caused by

  13. Micro- and nanocrystals of organic semiconductors.

    Science.gov (United States)

    Li, Rongjin; Hu, Wenping; Liu, Yunqi; Zhu, Daoben

    2010-04-20

    Organic semiconductors have attracted wide attention in recent decades, resulting in the rapid development of organic electronics. For example, the solution processibility of organic semiconductors allows researchers to use unconventional deposition methods (such as inkjet printing and stamping) to fabricate large area devices at low cost. The mechanical properties of organic semiconductors also allow for flexible electronics. However, the most distinguishing feature of organic semiconductors is their chemical versatility, which permits the incorporation of functionalities through molecular design. However, key scientific challenges remain before organic electronics technology can advance further, including both the materials' low charge carrier mobility and researchers' limited knowledge of structure-property relationships in organic semiconductors. We expect that high-quality organic single crystals could overcome these challenges: their purity and long-range ordered molecular packing ensure high device performance and facilitate the study of structure-property relationships. Micro- and nanoscale organic crystals could offer practical advantages compared with their larger counterparts. First, growing small crystals conserves materials and saves time. Second, devices based on the smaller crystals could maintain the functional advantages of larger organic single crystals but would avoid the growth of large crystals, leading to the more efficient characterization of organic semiconductors. Third, the effective use of small crystals could allow researchers to integrate these materials into micro- and nanoelectronic devices using a "bottom-up" approach. Finally, unique properties of crystals at micro- and nanometer scale lead to new applications, such as flexible electronics. In this Account, we focus on organic micro- and nanocrystals, including their design, the controllable growth of crystals, and structure-property studies. We have also fabricated devices and

  14. Combined micro-PET/micro-CT imaging of lung tumours in SPC-raf and SPC-myc transgenic mice.

    Directory of Open Access Journals (Sweden)

    Thomas Rodt

    Full Text Available INTRODUCTION: SPC-raf and SPC-myc transgenic mice develop disseminated and circumscribed lung adenocarcinoma respectively, allowing for assessment of carcinogenesis and treatment strategies. The purpose of this study was to investigate the technical feasibility, the correlation of initial findings to histology and the administered radiation dose of combined micro-PET/micro-CT in these animal models. MATERIAL AND METHODS: 14 C57BL/6 mice (4 nontransgenic, 4 SPC-raf transgenic, 6 SPC-myc transgenic were examined using micro-CT and (18F-Fluoro-deoxyglucose micro-PET in-vivo. Micro-PET data was corrected for random events and scatter prior to reconstruction with a 3D-FORE/2D-OSEM iterative algorithm. Rigid micro-PET/micro-CT registration was performed. Tumour-to-non-tumour ratios were calculated for different lung regions and focal lesions. Diffuse tumour growth was quantified using a semiautomated micro-CT segmentation routine reported earlier. Regional histologic tumour load was assessed using a 4-point rating scale. Gamma radiation dose was determined using thermoluminescence dosimeters. RESULTS: Micro-CT allowed visualisation of diffuse and circumscribed tumours in SPC-raf and SPC-myc transgenic animals along with morphology, while micro-PET provided information on metabolism, but lacked morphologic detail. Mean tumour-to-non-tumour ratio was 2.47 for circumscribed lesions. No significant correlation could be shown between histological tumour load and tumour-to-nontumour ratio for diffuse tumours in SPC-raf transgenic animals. Calculation of the expected dose based on gamma dosimetry yielded approximately 140 mGy/micro-PET examination additional to approximately 200 mGy due to micro-CT. CONCLUSIONS: Combined micro-PET/micro-CT imaging allows for in-vivo assessment of lung tumours in SPC-raf and SPC-myc transgenic mice. The technique has potential for the evaluation of carcinogenesis and treatment strategies in circumscribed lung tumours.

  15. Pervasive microRNA Duplication in Chelicerates: Insights from the Embryonic microRNA Repertoire of the Spider Parasteatoda tepidariorum.

    Science.gov (United States)

    Leite, Daniel J; Ninova, Maria; Hilbrant, Maarten; Arif, Saad; Griffiths-Jones, Sam; Ronshaugen, Matthew; McGregor, Alistair P

    2016-08-03

    MicroRNAs are small (∼22 nt) noncoding RNAs that repress translation and therefore regulate the production of proteins from specific target mRNAs. microRNAs have been found to function in diverse aspects of gene regulation within animal development and many other processes. Among invertebrates, both conserved and novel, lineage specific, microRNAs have been extensively studied predominantly in holometabolous insects such as Drosophila melanogaster However little is known about microRNA repertoires in other arthropod lineages such as the chelicerates. To understand the evolution of microRNAs in this poorly sampled subphylum, we characterized the microRNA repertoire expressed during embryogenesis of the common house spider Parasteatoda tepidariorum We identified a total of 148 microRNAs in P. tepidariorum representing 66 families. Approximately half of these microRNA families are conserved in other metazoans, while the remainder are specific to this spider. Of the 35 conserved microRNAs families 15 had at least two copies in the P. tepidariorum genome. A BLAST-based approach revealed a similar pattern of duplication in other spiders and a scorpion, but not among other chelicerates and arthropods, with the exception of a horseshoe crab. Among the duplicated microRNAs we found examples of lineage-specific tandem duplications, and the duplication of entire microRNA clusters in three spiders, a scorpion, and in a horseshoe crab. Furthermore, we found that paralogs of many P. tepidariorum microRNA families exhibit arm switching, which suggests that duplication was often followed by sub- or neofunctionalization. Our work shows that understanding the evolution of microRNAs in the chelicerates has great potential to provide insights into the process of microRNA duplication and divergence and the evolution of animal development.

  16. Combined micro-PET/micro-CT imaging of lung tumours in SPC-raf and SPC-myc transgenic mice.

    Science.gov (United States)

    Rodt, Thomas; Luepke, Matthias; Boehm, Claudia; Hueper, Katja; Halter, Roman; Glage, Silke; Hoy, Ludwig; Wacker, Frank; Borlak, Juergen; von Falck, Christian

    2012-01-01

    SPC-raf and SPC-myc transgenic mice develop disseminated and circumscribed lung adenocarcinoma respectively, allowing for assessment of carcinogenesis and treatment strategies. The purpose of this study was to investigate the technical feasibility, the correlation of initial findings to histology and the administered radiation dose of combined micro-PET/micro-CT in these animal models. 14 C57BL/6 mice (4 nontransgenic, 4 SPC-raf transgenic, 6 SPC-myc transgenic) were examined using micro-CT and (18)F-Fluoro-deoxyglucose micro-PET in-vivo. Micro-PET data was corrected for random events and scatter prior to reconstruction with a 3D-FORE/2D-OSEM iterative algorithm. Rigid micro-PET/micro-CT registration was performed. Tumour-to-non-tumour ratios were calculated for different lung regions and focal lesions. Diffuse tumour growth was quantified using a semiautomated micro-CT segmentation routine reported earlier. Regional histologic tumour load was assessed using a 4-point rating scale. Gamma radiation dose was determined using thermoluminescence dosimeters. Micro-CT allowed visualisation of diffuse and circumscribed tumours in SPC-raf and SPC-myc transgenic animals along with morphology, while micro-PET provided information on metabolism, but lacked morphologic detail. Mean tumour-to-non-tumour ratio was 2.47 for circumscribed lesions. No significant correlation could be shown between histological tumour load and tumour-to-nontumour ratio for diffuse tumours in SPC-raf transgenic animals. Calculation of the expected dose based on gamma dosimetry yielded approximately 140 mGy/micro-PET examination additional to approximately 200 mGy due to micro-CT. Combined micro-PET/micro-CT imaging allows for in-vivo assessment of lung tumours in SPC-raf and SPC-myc transgenic mice. The technique has potential for the evaluation of carcinogenesis and treatment strategies in circumscribed lung tumours.

  17. Effect of periodic fluctuation of soil particle rotation resistance on interface shear behaviour

    Science.gov (United States)

    Ebrahimian, Babak; Noorzad, Asadollah

    2010-06-01

    The interface behaviour between infinite extended narrow granular layer and bounding structure is numerically investigated using finite element method. The micro-polar (Cosserat) continuum approach within the framework of elasto-plasticity is employed to remove the numerical difficulties caused by strain-softening of materials in classical continuum mechanics. Mechanical properties of cohesionless granular soil are described with Lade's model enhanced with polar terms including Cosserat rotations, curvatures and couple stresses via mean grain diameter as the internal length. The main attention of paper is laid on the influence of spatial periodic fluctuation of rotation resistance of soil particles interlocked with the surface of bounding structure on evolution and location of shear band developed inside granular body. The finite element results demonstrate that the location and evolution of shear localization in granular body is strongly affected by prescribed non-uniform micro-polar kinematic boundary conditions along the interface.

  18. A micro gas chromatography column with a micro thermal conductivity detector for volatile organic compound analysis.

    Science.gov (United States)

    Sun, J H; Cui, D F; Chen, X; Zhang, L L; Cai, H Y; Li, H

    2013-02-01

    In this paper, a micro gas chromatography (μGC) system contained a μGC column and a micro thermal conductivity detector (μTCD) was proposed. In order to reduce the volume of the system, some micro heaters were integrated on the surface and backside of the GC column, which could provide a robust temperature programming capability and rapidly increase the temperature of the μGC column. In addition, a silicon-glass μTCD with four-thermistor thermal conductivity cells that can offer significant advantages over previously reported designs including low dead volume, good thermal isolation, and elimination of the thermal noise was proposed in this paper. Experimental results have indicated that the μGC system with a detection limit of several ppm concentration levels separated and detected the benzene, toluene, and styrene in less than 3 min, and the μGC system also exhibited a good linear response in the test range.

  19. Micro precision casting based on investment casting for micro structures with high aspect ratio

    Institute of Scientific and Technical Information of China (English)

    YANG Chuang; LI Bang-sheng; REN Ming-xing; FU Heng-zhi

    2009-01-01

    Microcasting is one of the significant technologies for the production of metallic micro parts with high aspect ratio (ratio of flow length to diameter). A micro precision casting technology based on investment casting using centrifugal method was investigated. The micro parts of Zn-4%Al alloy with an aspect ratio up to 200 was produced at the centrifugal speed of 1 500 r/min and the mold temperature of 270 ℃. The investigations on the relationship between flow length and rotational speed were carried out. For microcasting, the flow length is not only dependent on the centrifugal speed under the constant centrifugal radius, but also on the preheating temperature of mold. The flow length increases as the rotational speed and the mold temperature increase, and is much higher at a mold temperature of 270 ℃ than at other mold temperatures.

  20. Model of Polysilicon Electro-thermal Micro Actuator and Research of Micro Scale Effect

    Institute of Scientific and Technical Information of China (English)

    ZHANGYong-yu; SHENXue-jin; CHENXiao-yang

    2004-01-01

    A type of crank beam electro-thermal mircro actuator was prescribed Mechanical model of the actuatar was estabilished,and the static characteristic was analzed Comparing the theoretical analzsis with experimental data,it is found that the thermodynamic character of material in micro actuator has a different variable regularity contrasted to that used in macro scale machines.it is the micro scale effect that results in the deriation between the simulating result and experimental results the thermodynamic expression of polysilicon which was fitted by means of the experimental data concerned was used to modify the mechanical model The modifiex model ,in which the mircro scale thermodynamic characteristic characteristic was considered,was more reasonable and could make the optimal design and control strategies analyzing the straight-line micro actuator more feasible.

  1. High accuracy and precision micro injection moulding of thermoplastic elastomers micro ring production

    DEFF Research Database (Denmark)

    Calaon, Matteo; Tosello, Guido; Elsborg, René

    2016-01-01

    of using tool geometries as reference calibrated artefacts to establish effective process technology development and control. The results allow identifying the correct process windows for optimal part quality reducing product dimensional variation in the micrometer dimensional range. The proposed......The mass-replication nature of the process calls for fast monitoring of process parameters and product geometrical characteristics. In this direction, the present study addresses the possibility to develop a micro manufacturing platform for micro assembly injection moulding with real-time process/product...... monitoring and metrology. The study represent a new concept yet to be developed with great potential for high precision mass-manufacturing of highly functional 3D multi-material (i.e. including metal/soft polymer) micro components. The activities related to HINMICO project objectives proves the importance...

  2. Micro Blog:un monde des rumeurs%Micro Blog : un monde des rumeurs

    Institute of Scientific and Technical Information of China (English)

    杨洁

    2012-01-01

    Quel est le divertissement le plus populaire sur Internet depuis ao(u)t 2009 en Chine ? Ce serait le Micro Blog du site web Sina.Avec 100 millions d'utilisateurs,ce Micro Blog est une plate-forme où l'on peut partager,diffuser et obtenir des informations immédiatement.En comparaison d'autres micro blogs tels que twitter et facebook,celui de Sina nous offre plus de services.Avec 140 mots,nous pouvons bien exprimer au moins une idée en chinois.De plus,en diffusant des critiques,des photos,des vidéos et des chansons,chacun devient jourr(n)aliste en observant et enregistrant les nouvelles de la vie.

  3. Micro Sourcing Strategic Framework for Low Income Group

    Directory of Open Access Journals (Sweden)

    Noor Habibah Arshad

    2013-07-01

    Full Text Available The role of ICTs among poor people and communities has increased tremendously. One of the ICT industries – the micro sourcing industry – has been identified as one of a potential industry to help increase income for the poor in Malaysia. Micro sourcing is an effective way to accomplish tedious tasks at a faster rate. It involves large projects that are broken down into micro tasks. These micro tasks are well-defined and then distributed to a group of workers. The objective of this study is to develop the strategic framework of micro sourcing to generate income for the low income group. Four methods were used to gather information for this study. The methods used were documentation and literature reviews, focus group meetings, workshops and interviews. Based on the analysis of the current scenario of local micro sourcing industry, strategic framework was developed based on the five Strategic Thrusts identified. The Strategic Thrusts are harnessing demand side (job providers of domestic and international market; platform capacity and capability building; leverage and utilise existing infrastructure; uplift and enhance capability of the supply side (micro workers; and instruments to expedite growth of local micro sourcing industry. The Strategic Framework is intended to provide strategic direction at national level to all stakeholders; to highlight key areas that need to be addressed in order to grow a sustainable micro sourcing industry in the country; and to serve as a guideline in the implementation of programs and plans related to micro sourcing industry development

  4. The study of double flank micro gear roll testing

    Science.gov (United States)

    Liu, Yen-Chih; An, Nai-Chun; Yang, Shu-Han; Yan, Sheng-Zhan; Chen, Shih-Lu

    2011-12-01

    The recent fast development of multifunctional portable electronic devices results in the obvious requirement of micro mechanical components. Due to the popular application of the micro actuators and the micro gearboxes, micro gears become the frequently used micro mechanical component in a small device such as small intelligent robots or dental surgical devices. Metal Industries Research & Development Centre (MIRDC) has successfully developed a small speed reducer that comprises several micro planetary gear trains. The module of this micro planetary gear train is 0.12mm. Since all gears are small, no commercial instrument is available for inspection. How to evaluate the manufacturing quality of micro gears becomes an important issue. This study focuses on the double flank gear rolling test and a specialized apparatus is built referring to the testing requirements in the international standards. The center distance variation during the rolling test is recorded and two indices, the total radial composite deviation and the maximum tooth-to-tooth radial composite deviation, are calculated to evaluate the accuracy grade of the micro gears. Experimental results show that the accuracy of the micro gear made by the cold forging process conforms to grade 7 defined in the ISO 1328-2 while grade 2 is achieved if the JGMA 116-02 is specified.

  5. Eye vision system using programmable micro-optics and micro-electronics

    Science.gov (United States)

    Riza, Nabeel A.; Amin, M. Junaid; Riza, Mehdi N.

    2014-02-01

    Proposed is a novel eye vision system that combines the use of advanced micro-optic and microelectronic technologies that includes programmable micro-optic devices, pico-projectors, Radio Frequency (RF) and optical wireless communication and control links, energy harvesting and storage devices and remote wireless energy transfer capabilities. This portable light weight system can measure eye refractive powers, optimize light conditions for the eye under test, conduct color-blindness tests, and implement eye strain relief and eye muscle exercises via time sequenced imaging. Described is the basic design of the proposed system and its first stage system experimental results for vision spherical lens refractive error correction.

  6. Micro-micro hierarchy replacing micro-nano hierarchy: a precisely controlled way to produce wear-resistant superhydrophobic polymer surfaces.

    Science.gov (United States)

    Huovinen, Eero; Hirvi, Janne; Suvanto, Mika; Pakkanen, Tapani A

    2012-10-16

    Superhydrophobic polymer surfaces are typically fabricated by combining hierarchical micro-nanostructures. The surfaces have a great technological potential because of their special water-repellent and self-cleaning properties. However, the poor mechanical robustness of such surfaces has severely limited their use in practical applications. This study presents a simple and swift mass production method for manufacturing hierarchically structured polymer surfaces at micrometer scale. Polypropylene surface structuring was done using injection molding, where the microstructured molds were made with a microworking robot. The effect of the micro-microstructuring on the polymer surface wettability and mechanical robustness was studied and compared to the corresponding properties of micro-nanostructured surfaces. The static contact angles of the micro-microstructured surfaces were greater than 150° and the contact angle hysteresis was low, showing that the effect of hierarchy on the surface wetting properties works equally well at micrometer scale. Hierarchically micro-microstructured polymer surfaces exhibited the same superhydrophobic wetting properties as did the hierarchically micro-nanostructured surfaces. Micro-microstructures had superior mechanical robustness in wear tests as compared to the micro-nanostructured surfaces. The new microstructuring technique offers a precisely controlled way to produce superhydrophobic wetting properties to injection moldable polymers with sufficiently high intrinsic hydrophobicity.

  7. MicroRNA signature of the human developing pancreas

    Directory of Open Access Journals (Sweden)

    Correa-Medina Mayrin

    2010-09-01

    Full Text Available Abstract Background MicroRNAs are non-coding RNAs that regulate gene expression including differentiation and development by either inhibiting translation or inducing target degradation. The aim of this study is to determine the microRNA expression signature during human pancreatic development and to identify potential microRNA gene targets calculating correlations between the signature microRNAs and their corresponding mRNA targets, predicted by bioinformatics, in genome-wide RNA microarray study. Results The microRNA signature of human fetal pancreatic samples 10-22 weeks of gestational age (wga, was obtained by PCR-based high throughput screening with Taqman Low Density Arrays. This method led to identification of 212 microRNAs. The microRNAs were classified in 3 groups: Group number I contains 4 microRNAs with the increasing profile; II, 35 microRNAs with decreasing profile and III with 173 microRNAs, which remain unchanged. We calculated Pearson correlations between the expression profile of microRNAs and target mRNAs, predicted by TargetScan 5.1 and miRBase altgorithms, using genome-wide mRNA expression data. Group I correlated with the decreasing expression of 142 target mRNAs and Group II with the increasing expression of 876 target mRNAs. Most microRNAs correlate with multiple targets, just as mRNAs are targeted by multiple microRNAs. Among the identified targets are the genes and transcription factors known to play an essential role in pancreatic development. Conclusions We have determined specific groups of microRNAs in human fetal pancreas that change the degree of their expression throughout the development. A negative correlative analysis suggests an intertwined network of microRNAs and mRNAs collaborating with each other. This study provides information leading to potential two-way level of combinatorial control regulating gene expression through microRNAs targeting multiple mRNAs and, conversely, target mRNAs regulated in

  8. Effects of hydrofluoric acid and anodised micro and micro/nano surface implants on early osseointegration in rats.

    Science.gov (United States)

    Li, Yongfeng; Gao, Yuan; Shao, Bo; Xiao, Jianrui; Hu, Kaijin; Kong, Liang

    2012-12-01

    Our aim was to evaluate the effects of hydrofluoric acid and anodised micro and micro/nano surface implants on bony ingrowth in the earliest stage of implantation in rats. Sixty cylindrical screwed titanium alloy implants with machined, micro, and hierarchical hybrid micro/nano surfaces (n=20 in each group) were inserted into the distal femurs of 30 female Sprague-Dawley rats. In vivo microcomputed tomography (micro CT) was used to assess microarchitectural changes in the bone around the implants 2 weeks after implantation. All the animals were then killed and the femurs with implants harvested for histological analysis and pull-out testing. Micro CT analysis showed that the trabecular thickness and the bone:volume ratio (bone volume:total volume) (BV:TV) increased significantly in the micro/nano group compared with the other two groups, while the trabecular separation decreased significantly in the micro/nano group compared with the machined group. The mean (SD) bone-implant contacts (%) were 38.94 (9.48), 41.67 (8.71), and 51.49 (12.49) in the machined, micro, and micro/nano groups, respectively. The maximum pull-out forces (N) were 64.95 (6.11), 71.45 (7.15), and 81.90 (13.1), respectively. Both bone-implant contacts and maximum pull-out forces were significantly higher in the micro/nano group, but there was no significant difference between the micro group and the machined group. These data indicate that the hierarchical hybrid micro/nano surface of the implant can promote osseointegration in the earliest stage of implantation, and may be a promising option for further clinical use.

  9. Clinical micro-CT for dental imaging

    Science.gov (United States)

    Youn, Hanbean; Cho, Min Kook; Shon, Cheol-Soon; Cho, Bong Hae; Kim, Chang Hyuk; Kim, Ho Kyung

    2009-02-01

    We exploit the development of a clinical computed microtomography (micro-CT) system for dental imaging. While the conventional dental CT simply serves implant treatment, the clinical dental micro-CT may provide clinicians with a histologic evaluation. To investigate the feasibility of the realization of a dental micro-CT, we have constructed an experimental test system which mainly consists of a microfocus x-ray source, a rotational subject holder, and a flat-panel detector. The flat-panel detector is based on a matrix-addressed photodiode array coupled to a CsI:Tl scintillator. The detective quantum efficiency (DQE) of the detector was measured as a function of magnification based on the measured modulation-transfer function (MTF) and noise-power spectrum (NPS). The best MTF and DQE performances were achieved at the magnification factor of 3. Similar tendency of the spatial resolving power in tomography was also observed with a wire phantom having a 25 μm diameter. From the investigation of tomographs reconstructed from a humanoid skull phantom, the application of magnification in the system largely reduced both signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) for a fixed dose at the entrance surface of the detector, 1.2 mGy, while this setup increased the dose at the object plane from 4.7 mGy to 19.1 mGy for the magnification factor from 2 to 4, respectively. Although the quantum mottles at the high magnification factor tackled the practical use in the clinic, the information contained in the magnified CT images was quite promising.

  10. Micro-financing of renewable energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Bunse, Maike; Wallbaum, Holger [triple innova (Germany); Dienst, Carmen [Wuppertal Inst. for Climate, Environment, Energy (Germany)

    2007-07-01

    While improved energy services have many quality of life benefits like lighting or television, the productive use of electricity can also help to reduce poverty, leading to increased profitability and productivity for micro, small and medium enterprises, and small industries. The remoteness of rural locations usually makes it difficult to expand electricity supply through a centralised grid system. Therefore people living in off-grid regions often rely on expensive fossil fuels like diesel and kerosene. People in remote areas often do not have the financial background to afford the initial costs for renewable energy applications. Micro-financing of renewable energy systems is a possible answer to provide financial services and support productive activities in a sustainable manner for low-income people. There are various types of microfinance institutions (MFIs), ranging from local cooperatives, NGOs, credit unions, private commercial banks and non-bank financial institutions as well as parts of state-owned banks.To underline the benefits of micro financing renewable energy systems, good practice projects of local microfinance activities are presented. These projects have been identified in the course of WISIONS, an initiative of the Wuppertal Inst. for Climate, Environment and Energy with support of ProEvolution, a Swiss-based foundation. The two different approaches of the project support on one side the realisation of new project ideas (SEPS - Sustainable Energy Project Support) and on the other spread successful examples (PREP - Promotion of Resource Efficiency Projects). Through the PREP field of action, good practices in energy and resource efficiency are spread worldwide through the Internet and brochures. In the 5th PREP-brochure of WISIONS on 'Microfinance and Renewable Energy' five good-practice examples are shown that link this promising financing system with modern and sustainable renewable energy technologies.

  11. MicroRNAs in renal fibrosis

    Directory of Open Access Journals (Sweden)

    Arthur Chi-Kong Chung

    2015-02-01

    Full Text Available MicroRNAs (miRNAs are endogenous short noncoding RNAs that regulate most of important cellular processes by inhibiting gene expression through the post-transcriptional repression of their target mRNAs. . In kidneys, miRNAs have been associated in renal development, homeostasis, and physiological functions. Results from clinical and experimental animal studies demonstrate that miRNAs play essential roles in the pathogenesis of various renal diseases. Chronic kidney diseases (CKD is characterized by renal fibrosis. Transforming growth factor beta (TGF-β is recognized as a major mediator of renal fibrosis because it is able to stimulate the accumulation of extracellular matrix proteins to impair normal kidney function. Recently, emerging evidence demonstrate the relationship between TGF-β signaling and miRNAs expression during renal diseases. TGF-β regulates expression of several microRNAs, such as miR-21, miR-192, miR-200, miR-433, and miR-29. MiR-21, miR-192, and miR-433 which are positively induced by TGF-β signaling play a pathological role in kidney diseases. In contrast, members in both miR-29 and miR-200 families which are inhibited by TGF-β signaling protect kidneys from renal fibrosis by suppressing the deposition of extracellular matrix and preventing epithelial-to-mesenchymal transition, respectively. Clinically, the presence of miRNAs in blood and urine has been examined to be early biomarkers for detecting renal diseases. From experimental animal studies of CKD, targeting microRNAs also provides evidence about therapeutic potential of miRNAs during renal diseases. Now, it comes to the stage to examine the exact mechanisms of miRNAs during the initiation and progression of renal diseases. Therefore, determining the function of miRNAs in renal fibrosis may facilitate the development of both early diagnosis and treatment of renal diseases.

  12. MicroRNAs in neural cell development and brain diseases.

    Science.gov (United States)

    Feng, Wei; Feng, Yue

    2011-12-01

    MicroRNAs play important roles in post-transcriptional regulation of gene expression by inhibiting protein translation and/or promoting mRNA degradation. Importantly, biogenesis of microRNAs displays specific temporal and spatial profiles in distinct cell and tissue types and hence affects a broad spectrum of biological functions in normal cell growth and tumor development. Recent discoveries have revealed sophisticated mechanisms that control microRNA production and homeostasis in response to developmental and extracellular signals. Moreover, a link between dysregulation of microRNAs and human brain disorders has become increasingly evident. In this review, we focus on recent advances in understanding the regulation of microRNA biogenesis and function in neuronal and glial development in the mammalian brain, and dysregulation of the microRNA pathway in neurodevelopmental and neurodegenerative diseases.

  13. Micro/nano-fabrication technologies for cell biology.

    Science.gov (United States)

    Qian, Tongcheng; Wang, Yingxiao

    2010-10-01

    Micro/nano-fabrication techniques, such as soft lithography and electrospinning, have been well-developed and widely applied in many research fields in the past decade. Due to the low costs and simple procedures, these techniques have become important and popular for biological studies. In this review, we focus on the studies integrating micro/nano-fabrication work to elucidate the molecular mechanism of signaling transduction in cell biology. We first describe different micro/nano-fabrication technologies, including techniques generating three-dimensional scaffolds for tissue engineering. We then introduce the application of these technologies in manipulating the physical or chemical micro/nano-environment to regulate the cellular behavior and response, such as cell life and death, differentiation, proliferation, and cell migration. Recent advancement in integrating the micro/nano-technologies and live cell imaging are also discussed. Finally, potential schemes in cell biology involving micro/nano-fabrication technologies are proposed to provide perspectives on the future research activities.

  14. SERS decoding of micro gold shells moving in microfluidic systems.

    Science.gov (United States)

    Lee, Saram; Joo, Segyeong; Park, Sejin; Kim, Soyoun; Kim, Hee Chan; Chung, Taek Dong

    2010-05-01

    In this study, in situ surface-enhanced Raman scattering (SERS) decoding was demonstrated in microfluidic chips using novel thin micro gold shells modified with Raman tags. The micro gold shells were fabricated using electroless gold plating on PMMA beads with diameter of 15 microm. These shells were sophisticatedly optimized to produce the maximum SERS intensity, which minimized the exposure time for quick and safe decoding. The shell surfaces produced well-defined SERS spectra even at an extremely short exposure time, 1 ms, for a single micro gold shell combined with Raman tags such as 2-naphthalenethiol and benzenethiol. The consecutive SERS spectra from a variety of combinations of Raman tags were successfully acquired from the micro gold shells moving in 25 microm deep and 75 microm wide channels on a glass microfluidic chip. The proposed functionalized micro gold shells exhibited the potential of an on-chip microfluidic SERS decoding strategy for micro suspension array.

  15. An Overview of Power Topologies for Micro-hydro Turbines

    DEFF Research Database (Denmark)

    Nababan, Sabar; Muljadi, E.; Blaabjerg, Frede

    2012-01-01

    This paper is an overview of different power topologies of micro-hydro turbines. The size of micro-hydro turbine is typically under 100kW. Conventional topologies of micro-hydro power are stand-alone operation used in rural electrical network in developing countries. Recently, many of micro-hydro...... power generations are connected to the distribution network through power electronics (PE). This turbines are operated in variable frequency operation to improve efficiency of micro-hydro power generation, improve the power quality, and ride through capability of the generation. In this paper our...... discussion is limited to the distributed generation. Like many other renewable energy sources, the objectives of micro-hydro power generation are to reduce the use of fossil fuel, to improve the reliability of the distribution system (grid), and to reduce the transmission losses. The overview described...

  16. Fabrication of punch and die of micro-blanking tool

    Science.gov (United States)

    Mahmudah, Aida; Kiswanto, Gandjar; Priadi, Dedi

    2017-06-01

    The difficulties of tool fabrication in micro level provide an enormous challenge due to the dimension limitation. Reducing the difficulty and tool cost fabrication should always be considered by determining the simplicity of tool geometry, precision tolerance, and an appropriate material selection. This paper study about the manufacturing of micro-blanking punch-die. The mechanical material removal method was chosen to fabricate punch-die since this is a single piece production and intended for small-scale production of micro parts. The manufacturing process consists of punch-die design and fabrication, tool assembly, and clearance measurement. The stress analysis is also conducted to ensure the strength of the punch-die. A micro-blanking experiment was held to observe the tool performance. The result showed that micro-blanking tool can be manufactured successfully and used well to conduct the micro-blanking experiment.

  17. Progress, challenges and new concepts in microRNAs

    Institute of Scientific and Technical Information of China (English)

    ZHANG YouYi

    2011-01-01

    MicroRNAs are a group of small noncoding RNAs.They have rapidly gained attention in the field as novel regulators of cellular morphology and function.Currently hundreds of microRNAs have been described in human genome.MicroRNAs play important roles in posttranscriptional regulation of gene expression by inhibiting protein translation and/or promoting mRNA degradation.MicroRNAs were initially thought to be subtle regulators of gene expression,but increasing evidence demonstrates that the regulatory functions of microRNAs are crucial for the cell.MicroRNAs have been found to be involved in the development,tissue homeostasis as well as diseases.

  18. Fabrication of curved micro structures on photoresist layer

    Institute of Scientific and Technical Information of China (English)

    Jae Sung YOON; Tae-Jin JE; Doo-Sun CHOI; Sung Hwan CHANG; Kyung-Hyun WHANG

    2011-01-01

    A novel fabrication process for micro patterns with curvature was introduced. The curved structures were made by compensating rectangular micro structures with liquid photoresist layer. Because of the surface tension of the liquid in micro scale,various shapes of meniscus can be made on the micro channels. The micro channels were made on the silicon substrate in advance,and then the liquid layer was coated on the micro channels. From the nature of liquid behavior, the curved patterns with smooth surface are obtained, which cannot be made easily with the conventional mechanical machining, as well as with the microfabrication processes, such as wet and dry etching. With this principle, it is expected that the smooth and curved surfaces can be made by simple processes and the results can be applied widely, such as optical patterns.

  19. A Novel Bio-mimetic Wireless Micro Robot for Endoscope

    Institute of Scientific and Technical Information of China (English)

    YE Dong-dong; YAN Guo-zheng; WANG Kua-dong; MA Guan-ying

    2008-01-01

    A novel bio-mimetic wireless micro robot for endoscope is developed. Its autonomous manner is earthworm-like and driven by linear actuators based on DC motor. It is different from the conventional micro robot endoscope that wireless module is used for communicating and power transfer. The fabricated micro robot system is detailedly described, including structure, micro robot locomotion principle, communication control module and wireless power transfer module. The experimental results show that the driving force of the lineaar actuator can reach to 2.55 N and supplying power is up to 480 mW DC power for receiving coil in the proposed system, which all fulfill the need of the micro robot system. The micro robot can creep reliably in the large intestine of pig and other contact environments.

  20. Novel drive mechanism for in-tube micro robots

    Institute of Scientific and Technical Information of China (English)

    CHEN Yangzhi; XING Guangquan; PENG Xuefei; LIU Wenguang; YAO Huaping

    2007-01-01

    The volume of an in-tube micro robot is small and its interior space is very limited. However, conventional transmission methods are unfit to drive in-tube micro robots. A novel micro drive mechanism called the micro-elastic- meshing-wheel is presented in this paper. It can be used for transmitting power and locomotion between two shafts, which are upright and cross in a micro space. The mechanical model of the novel drive mechanism is built, and the maximal trans- mission force is deduced. Then, sufficient experiments are carried out to test maximal transmission force produced by the novel drive mechanism. The calculation and experiment results show that the novel drive mechanism can transmit sufficient power to in-tube micro robots.

  1. Building micro and nanosystems with electrochemical discharges

    Energy Technology Data Exchange (ETDEWEB)

    Wuethrich, Rolf, E-mail: wuthrich@encs.concordia.c [Department of Mechanical and Industrial Engineering, Concordia University, 1455 de Maisonneuve Blvd. West, Montreal, QC (Canada); Allagui, Anis [Department of Mechanical and Industrial Engineering, Concordia University, 1455 de Maisonneuve Blvd. West, Montreal, QC (Canada)

    2010-11-30

    Since the discovery of the electrochemical discharge phenomenon by Fizeau and Foucault, several contributions have expanded the wide range of applications associated with this high current density electrochemical process. The complexity of the phenomenon, from the macroscopic to the microscopic scales, led since then to experimental and theoretical studies from different research fields. This contribution reviews the chemical and electrochemical perspectives where a mechanistic model based on results from radiation chemistry of aqueous solutions is proposed. In addition applications to micro-machining and fabrication of nanoparticles are discussed.

  2. Model Identification of a Micro Air Vehicle

    Institute of Scientific and Technical Information of China (English)

    Jorge Ni(n)o; Flavius Mitrache; Peter Cosyn; Robin De Keyser

    2007-01-01

    This paper is focused on the model identification of a Micro Air Vehicle (MAV) in straight steady flight condition. The identification is based on input-output data collected from flight tests using both frequency and time dontain techniques. The vehicle is an in-house 40 cm wingspan airplane. Because of the complex coupled, multivariable and nonlinear dynamics of the aircraft, linear SISO structures for both the lateral and longitudinal models around a reference state were derived. The aim of the identification is to provide models that can be used in future development of control techniques for the MAV.

  3. Fabrication of Micro Components by Electrochemical Deposition

    DEFF Research Database (Denmark)

    Tang, Peter Torben

    The main issue of this thesis is the combination of electrochemical deposition of metals and micro machining. Processes for electroplating and electroless plating of nickel and nickel alloys have been developed and optimised for compatibility with microelectronics and silicon based micromechanics....... The principles of general electrochemistry, electroplating, alloy plating, pulse plating and electroless plating are discussed, as well as measurement methods and improve-ment of important properties such as internal stress, material distribution, mechanical properties and magnetic properties. The use...... commercial processes for selective etching of copper and gold and for electroplating of gold and indium....

  4. Micro-combustor for gas turbine engine

    Science.gov (United States)

    Martin, Scott M.

    2010-11-30

    An improved gas turbine combustor (20) including a basket (26) and a multiplicity of micro openings (29) arrayed across an inlet wall (27) for passage of a fuel/air mixture for ignition within the combustor. The openings preferably have a diameter on the order of the quenching diameter; i.e. the port diameter for which the flame is self-extinguishing, which is a function of the fuel mixture, temperature and pressure. The basket may have a curved rectangular shape that approximates the shape of the curved rectangular shape of the intake manifolds of the turbine.

  5. Diversifying microRNA sequence and function.

    Science.gov (United States)

    Ameres, Stefan L; Zamore, Phillip D

    2013-08-01

    MicroRNAs (miRNAs) regulate the expression of most genes in animals, but we are only now beginning to understand how they are generated, assembled into functional complexes and destroyed. Various mechanisms have now been identified that regulate miRNA stability and that diversify miRNA sequences to create distinct isoforms. The production of different isoforms of individual miRNAs in specific cells and tissues may have broader implications for miRNA-mediated gene expression control. Rigorously testing the many discrepant models for how miRNAs function using quantitative biochemical measurements made in vivo and in vitro remains a major challenge for the future.

  6. Micro-Bioreactor Mimicking a Cellular Environment

    CERN Document Server

    Hase, M; Hamada, T; Yoshikawa, K; Hase, Masahiko; Yamada, Ayako; Hamada, Tsutomu; Yoshikawa, Kenichi

    2006-01-01

    We report that a cell-sized water droplet (CWD) with a diameter of several tens of microns can serve as a micro-biochemical reactor. Since the droplet inner surface is covered by a phospholipid layer, it provides an environment similar to that in living cells. The CWD is manipulated with laser tweezers and we monitor the time-development of biochemical reactions in a single CWD by fusing two droplets which contain a substrate and an enzyme, respectively. As actual examples of enzymatic reactions, we present results on the reaction of calcein with esterase and on the expression reaction of green fluorescent protein.

  7. Micro-Flying Robotics in Space Missions

    Science.gov (United States)

    Bardina, Jorge; Thirumalainambi, Rajkumar

    2005-01-01

    The Columbia Accident Investigation Board issued a major recommendation to NASA. Prior to return to flight, NASA should develop and implement a comprehensive inspection plan to determine the structural integrity of all Reinforced Carbon-Carbon (RCC) system components. This inspection plan should take advantage of advanced non-destructive inspection technology. This paper describes a non-intrusive technology with a micro-flying robot to continuously monitor inside a space vehicle for any stress related fissures, cracks and foreign material embedded in walls, tubes etc.

  8. Lead resistance in micro-organisms.

    Science.gov (United States)

    Jarosławiecka, Anna; Piotrowska-Seget, Zofia

    2014-01-01

    Lead (Pb) is an element present in the environment that negatively affects all living organisms. To diminish its high toxicity, micro-organisms have developed several mechanisms that allow them to survive exposure to Pb(II). The main mechanisms of lead resistance involve adsorption by extracellular polysaccharides, cell exclusion, sequestration as insoluble phosphates, and ion efflux to the cell exterior. This review describes the various lead resistance mechanisms, and the regulation of their expression by lead binding regulatory proteins. Special attention is given to the Pbr system from Cupriavidus metallidurans CH34, which involves a unique mechanism combining efflux and lead precipitation.

  9. Micro and Nanotechnologies Enhanced Biomolecular Sensing

    Directory of Open Access Journals (Sweden)

    Tza-Huei Wang

    2013-07-01

    Full Text Available This editorial summarizes some of the recent advances of micro and nanotechnology-based tools and devices for biomolecular detection. These include the incorporation of nanomaterials into a sensor surface or directly interfacing with molecular probes to enhance target detection via more rapid and sensitive responses, and the use of self-assembled organic/inorganic nanocomposites that inhibit exceptional spectroscopic properties to enable facile homogenous assays with efficient binding kinetics. Discussions also include some insight into microfluidic principles behind the development of an integrated sample preparation and biosensor platform toward a miniaturized and fully functional system for point of care applications.

  10. MicroRNAs: Potential biomarkers in cancer

    OpenAIRE

    George, G. P.; Mittal, Rama Devi

    2010-01-01

    microRNAs (miRNAs) are evolutionarily conserved small noncoding RNAs, also known as micromanagers of gene expression. Polymorphisms in the miRNA pathway (miR-polymorphisms) are emerging as powerful tools to study the biology of a disease and have the potential to be used in disease prognosis and diagnosis. Advancements in the miRNA field also indicate a clear involvement of deregulated miRNA gene signatures in cancers, and several polymorphisms in pre-miRNA, miRNA binding sites or targets hav...

  11. MicroRNA Delivery for Regenerative Medicine

    OpenAIRE

    Peng, Bo; Chen, Yongming; Leong, Kam W.

    2015-01-01

    MicroRNA (miRNA) directs post-transcriptional regulation of a network of genes by targeting mRNA. Although relatively recent in development, many miRNAs direct differentiation of various stem cells including induced pluripotent stem cells (iPSCs), a major player in regenerative medicine. An effective and safe delivery of miRNA holds the key to translating miRNA technologies. Both viral and nonviral delivery systems have seen success in miRNA delivery, and each approach possesses advantages an...

  12. Q-enhanced racetrack micro-resonators

    CERN Document Server

    Chamorro-Posada, Pedro

    2016-01-01

    A Q enhancement strategy for racetrack micro -resonators is put forward. The design is based on the modification of the resonator geometry in order to mitigate the two main sources of radiation loss in the presence of curved waveguides: the couplings from the straight waveguides to the bent sections and the continuous loss at the curved waveguide sectors. Numerical calculations show over $100\\%$ improvement of the Q factor in silicon nitride resonators. At the same time, the modifications of the geometry do not affect the coupling properties of the resonators in integrated optical circuits.

  13. Identification of plant microRNA homologs.

    Science.gov (United States)

    Dezulian, Tobias; Remmert, Michael; Palatnik, Javier F; Weigel, Detlef; Huson, Daniel H

    2006-02-01

    MicroRNAs (miRNAs) are a recently discovered class of non-coding RNAs that regulate gene and protein expression in plants and animals. MiRNAs have so far been identified mostly by specific cloning of small RNA molecules, complemented by computational methods. We present a computational identification approach that is able to identify candidate miRNA homologs in any set of sequences, given a query miRNA. The approach is based on a sequence similarity search step followed by a set of structural filters.

  14. In-membrane micro fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Omosebi, Ayokunle; Besser, Ronald

    2016-09-06

    An in-membrane micro fuel cell comprises an electrically-insulating membrane that is permissive to the flow of cations, such as protons, and a pair of electrodes deposited on channels formed in the membrane. The channels are arranged as conduits for fluids, and define a membrane ridge between the channels. The electrodes are porous and include catalysts for promoting the liberation of a proton and an electron from a chemical species and/or or the recombination of a proton and an electron with a chemical specie. The fuel cell may be provided a biosensor, an electrochemical sensor, a microfluidic device, or other microscale devices fabricated in the fuel cell membrane.

  15. Introducing Micro-finance in Sweden

    DEFF Research Database (Denmark)

    Barinaga, Ester

    2013-01-01

    The case describes the first year of efforts to introduce microfinance as a tool to work with vulnerable groups in Sweden, more particularly ex-convicts, former drug-addicts and longterm unemployed women of immigrant background. The teaching objective is to discuss whether micro-finance can be seen...... as a tool to catalyze social change in developed welfare states such as Sweden, or if it rather reinforces the very power structures it aims to subvert. The author uses the case to analyse the efforts to introduce a new concept to wellestablished economic and social actors, as well as to understand...

  16. Micro-facies of Dead Sea sediments

    Science.gov (United States)

    Neugebauer, Ina; Schwab, Markus J.; Brauer, Achim; Frank, Ute; Dulski, Peter; Kitagawa, Hiroyuki; Enzel, Yehouda; Waldmann, Nicolas; Ariztegui, Daniel; Drilling Party, Dsddp

    2013-04-01

    Lacustrine sediments infilling the Dead Sea basin (DSB) provide a rare opportunity to trace changing climates in the eastern Mediterranean-Levant region throughout the Pleistocene and Holocene. In this context, high-resolution investigation of changes in sediment micro- facies allow deciphering short-term climatic fluctuations and changing environmental conditions in the Levant. The Dead Sea is a terminal lake with one of the largest drainage areas in the Levant, located in the Mediterranean climate zone and influenced also by the Saharo-Arabian deserts. Due to drastic climatic changes in this region, an exceptionally large variety of lacustrine sediments has been deposited in the DSB. These sediments, partially the results of changing lake levels, primarily represent changes in precipitation (e.g. Enzel et al., 2008). Evaporites (halite and gypsum) reflect dry climatic conditions during interglacials, while alternated aragonite-detritus (AAD) is deposited during glacial lake level high-stands. Here we present the first micro-facies inventory of a ~450 m long sediment profile from the deepest part of the northern DSB (ICDP site 5017-1, ~300 m water depth). The sediment record comprises the last two glacial-interglacial cycles, with mainly AAD facies in the upper part of the Amora Formation (penultimate glacial) and the last glacial Lisan Formation. The last interglacial Samra and the Holocene Zeelim Formations are predominantly characterized by thick bedded halite deposits, intercalated by partly laminated detrital marl sequences. Representative sections of the different facies types have been analyzed for micro-facies on petrographic thin sections, supported by high-resolution µXRF element scanning, magnetic susceptibility measurements and microscopic fluorescence analysis. Furthermore, Holocene sediments retrieved at the deep basin core site have been compared to their shallow-water counterpart at the western margin of the lake (core DSEn; Migowski et al., 2004

  17. Micro-sensor thin-film anemometer

    Science.gov (United States)

    Sheplak, Mark (Inventor); McGinley, Catherine B. (Inventor); Spina, Eric F. (Inventor); Stephens, Ralph M. (Inventor); Hopson, Jr., Purnell (Inventor); Cruz, Vincent B. (Inventor)

    1996-01-01

    A device for measuring turbulence in high-speed flows is provided which includes a micro-sensor thin-film probe. The probe is formed from a single crystal of aluminum oxide having a 14.degree. half-wedge shaped portion. The tip of the half-wedge is rounded and has a thin-film sensor attached along the stagnation line. The bottom surface of the half-wedge is tilted upward to relieve shock induced disturbances created by the curved tip of the half-wedge. The sensor is applied using a microphotolithography technique.

  18. MicroRNAs in the Hypothalamus

    DEFF Research Database (Denmark)

    Meister, Björn; Herzer, Silke; Silahtaroglu, Asli

    2013-01-01

    MicroRNAs (miRNAs) are short (∼22 nucleotides) non-coding ribonucleic acid (RNA) molecules that negatively regulate the expression of protein-coding genes. Posttranscriptional silencing of target genes by miRNA is initiated by binding to the 3'-untranslated regions of target mRNAs, resulting in s...... of the hypothalamus and miRNAs have recently been shown to be important regulators of hypothalamic control functions. The aim of this review is to summarize some of the current knowledge regarding the expression and role of miRNAs in the hypothalamus....

  19. [Nonsurgical micro-endodontics and its outcome].

    Science.gov (United States)

    Ling, Jun-qi; Wei, Xi

    2006-02-01

    The introduction of dental operating microscope and microscopic instruments including ultrasonic tips has revealed the endodontic therapy. Dental operating microscope provides magnification and illumination for the operational area. Cases which should be treated by surgical approach in the past can be managed predictably by nonsurgical micro-endodontics. The use of dental operating microscope and ultrasonics in non-surgical endodontics includes location of missed canal, removal of intracanal post and separated instruments, negotiation of ledged canals, management of apical transportation and perforation repair.

  20. Development of Fundamental Technologies for Micro Bioreactors

    Science.gov (United States)

    Sato, Kiichi; Kitamori, Takehiko

    This chapter reviews the development of fundamental technologies required for microchip-based bioreactors utilizing living mammalian cells and pressure driven flow. The most important factor in the bioreactor is the cell culture. For proper cell culturing, continuous medium supply from a microfluidic channel and appropriate modification of the channel surface to accommodate cell attachment is required. Moreover, the medium flow rate should be chosen carefully, because shear stress affects cell activity. The techniques presented here could be applied to the development of micro bioreactors such as microlivers, pigment production by plant cells, and artificial insemination.