The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform

Masamichi Kohno - One of the best experts on this subject based on the ideXlab platform.

  • thermal conductivity enhancement of lauric acid phase change nanocomposite in solid and liquid state with single walled carbon nanohorn inclusions
    Thermochimica Acta, 2015
    Co-Authors: Sivasankaran Harish, Daniel Orejon, Yasuyuki Takata, Masamichi Kohno
    Abstract:

    Abstract We prepared lauric acid based phase change nanocomposite embedded with chemically functionalized single-walled carbon nanohorns and measured its thermal properties. We report contrasting enhancements in thermal conductivity of such nanocomposites in the solid and liquid phase for the same loading of nanohorn inclusions. Maximum thermal conductivity enhancement in solid and liquid phase at 2 vol% is found to be ∼37 and ∼11%, respectively. The nanocomposites’ thermal conductivity enhancement is compared with calculations of effective medium theory considering the role of interfacial thermal transport. Model calculations show that Kapitza resistance is an order of magnitude lower at the solid–solid Interface compared to the solid–liquid Interface. Differential scanning calorimetry study of the nanocomposites shows that the phase change temperature and enthalpy marginally increases to that of pristine material. Such a nanocomposite with enhanced thermal transport and phase change enthalpy makes it a promising candidate for thermal energy storage applications.

Jian Jun Chen - One of the best experts on this subject based on the ideXlab platform.

  • A Reflective Nonlinear Acoustic Microscope to Contour the Quantitative Adhesion at a Bonded Solid-Solid Interface
    Chinese Physics Letters, 2014
    Co-Authors: Jian Jun Chen, De Zhang
    Abstract:

    We set up a reflective nonlinear acoustic microscope to contour the quantitative adhesion at a bonded Solid-Solid Interface by a contact acoustic nonlinearity (CAN) method. The principle of the reflective nonlinear acoustic microscope is described. After the vibration amplitude of the incident, focusing wave at the bonded Interface is calculated, the standard adhesion with a complete bonding state is established by the tension test, the reflective CAN parameter is calibrated, and the quantitative contour of the adhesion at the Interface can be obtained. The experimental contours of two samples are also presented. Compared with the transmitted microscope, the reflective one is more convenient and more suitable for practical applications.

  • A can method to image the quantitative bonding strength at the bonded Solid-Solid Interface
    Piezoelectricity, Acoustic Waves and Device Applications (SPAWDA), 2012 Symposium on, 2012
    Co-Authors: Jian Jun Chen, De Zhang, Yi-wei Mao
    Abstract:

    As well known, when a longitudinal wave propagates through an Interface with micro-cracks and micro-defects between solids, the contact acoustic nonlinearity (CAN) will be generated dramatically and the nonlinear parameter can be used to contour the bonding state of the Interface. However the contour can only show the relative state of bonding strength and can not be used to judge weather the multilayered composite materials in use is safe because the safe judgment is not by the relative state while by the absolute value of the bonding strength. Therefore characterization of quantitative bonding strength at the Interface is very important for judging a multilayered material in safe use. In this paper, how to get the quantitative bonding strength from the CAN parameter is studied. After the vibration amplitude of incident focusing wave at the bonded Interface was calculated, the standard bonding strength with complete bonding state was established by tension test and CAN parameter is calibrated, the quantitative imaging of the bonding strength is obtained by CAN microscope in experiments. From the imaging, the positions with weak bonding strength could be easily located, which can be used to decide whether the material could be employed continuously.

  • contact acoustic nonlinearity in a bonded solid solid Interface
    Ultrasonics, 2006
    Co-Authors: Jian Jun Chen, De Zhang, Jianchun Cheng
    Abstract:

    Abstract We have conducted research on the contact acoustic nonlinearity (CAN) produced by a bonded solid–solid Interface in order to find a nondestructive and quantitative method to evaluate the bonding strength of the Interface. A CAN model is used to depict a bonded state from the relationship between the CAN parameter and the bonding strength and the crack width in the Interface. According to this model, a nondestructive evaluation of the bonding strength can be established. When the CAN parameter and the crack width are measured, the bonding strength can be calculated from the model. In this paper, the bonding strengths of some samples are evaluated based on the CAN method. The results well agree with the bonding strengths measured by hanging clogs (weights) to destroy their Interfaces.

  • Contact acoustic nonlinearity in a bonded solid–solid Interface
    Ultrasonics, 2006
    Co-Authors: Jian Jun Chen, De Zhang, Jianchun Cheng
    Abstract:

    Abstract We have conducted research on the contact acoustic nonlinearity (CAN) produced by a bonded solid–solid Interface in order to find a nondestructive and quantitative method to evaluate the bonding strength of the Interface. A CAN model is used to depict a bonded state from the relationship between the CAN parameter and the bonding strength and the crack width in the Interface. According to this model, a nondestructive evaluation of the bonding strength can be established. When the CAN parameter and the crack width are measured, the bonding strength can be calculated from the model. In this paper, the bonding strengths of some samples are evaluated based on the CAN method. The results well agree with the bonding strengths measured by hanging clogs (weights) to destroy their Interfaces.

  • An evaluation method of bonding strength at a bonded Solid-Solid Interface by contact acoustic nonlinearity
    IEEE Ultrasonics Symposium 2005., 2005
    Co-Authors: De Zhang, Jian Jun Chen
    Abstract:

    This paper presents a nondestructive method to evaluate the bonding strength of the Interface of bonded Solid-Solid. It is based on a contact acoustic nonlinearity (CAN) phenomenon produced by a bonded Solid-Solid Interface when a longitudinal wave propagates through the Interface. The CAN model is set up to depict a bonded state by the relationship between the bonding strength and the crack width in the Interface and the CAN parameter described by the ratio, 2 21 / AA , between the amplitudes of the second harmonic and fundamental waves. According to this model, a nondestructive evaluation of the bonding strength can be established. When the CAN parameter and the crack width are measured, the bonding strength can be evaluated from the model. In this paper, experiments have been done to demonstrate the model and the bonding strengths of some samples are evaluated based on the CAN method, The results (the example of 10.2kg/cm 2 by CAN model) are well agree with the bonding strengths (9.9 kg/cm 2 ) measured by hanging clogs to destroy their Interfaces.

Boo Cheong Khoo - One of the best experts on this subject based on the ideXlab platform.

  • The ghost solid methods for the elastic-plastic Solid-Solid Interface and the θ-criterion
    Journal of Computational Physics, 2015
    Co-Authors: A Kaboudian, P. Tavallali, Boo Cheong Khoo
    Abstract:

    Two variants of the Ghost Solid Method (GSM), namely the Original GSM (OGSM) and Modified GSM (MGSM), are proposed for the elastic-plastic Solid-Solid interactions in a Lagrangian framework. It is shown that the OGSM is highly problem related and can lead to large numerical errors under certain material combinations or in the presence of the wave propagation through the Solid-Solid Interface. The ?-criterion, previously developed for the elastic-elastic Solid-Solid interactions 1, has been applied to the OGSM for the elastic-plastic interactions. It is shown that this criterion can successfully detect the onset of these large errors. Moreover, it is shown that it can be used to determine the reliability of the results obtained using the OGSM. The MGSM has been shown to be able to remove the large numerical errors that would normally arise due to the OGSM. Next, the extension of the two variants of the GSM, to two-dimensional settings, is presented for two idealized Interface conditions, namely the no-slip condition, and the perfect-slip conditions. Numerous numerical experiments are provided attesting to the effectiveness and viability of the GSMs, for simulating wave propagation at the elastic-plastic Solid-Solid Interface. The applicability of the ?-criterion is also studied in the numerical experiments.

  • the ghost solid method for the elastic solid solid Interface
    Journal of Computational Physics, 2014
    Co-Authors: A Kaboudian, Boo Cheong Khoo
    Abstract:

    In this work, three variants of Ghost Solid Method (GSM) are proposed for application to the boundary conditions at the Solid-Solid Interface of isotropic linearly elastic materials, in a Lagrangian framework. It is shown that, in the presence of the wave propagation through the Solid-Solid mediums, the original GSM [1] can lead to non-physical oscillations in the solution, even for first-order solvers. It is discussed and numerically shown that these oscillations will be more severe if a higher order solver is employed using the original GSM. A scheme for prediction of these non-physical oscillations at the Interface is also introduced. The other two variants of GSM proposed, however, can remove the non-physical oscillations that may rise at the Interface. Next, the extension to two-dimensional settings with slip and no-slip conditions at the Interface is carried out. Numerous numerical examples in one- and two-dimensional settings are provided attesting to the viability and effectiveness of the GSM for treating wave propagation at the Solid-Solid Interface.

Nicholas Blagden - One of the best experts on this subject based on the ideXlab platform.

  • stabilizing a solid solid Interface with a molecular scale adhesive
    Nature, 1999
    Co-Authors: Roger J. Davey, H. F. Lieberman, L Williamsseton, Nicholas Blagden
    Abstract:

    The industrial importance of molecular materials chemistry has promoted great interest in areas such as self-assembled surface coatings1, multi-layer formation on solid substrates2, crystallization from solutions3, crystal morphology4 and structure prediction5, solving structures from powders6 and control of polymorphism7. Improvements in our understanding of the role of intermolecular interactions in driving molecular self-assembly and interfacial processes have led to technological advances—both in controlling the assembly of molecules at the nanometre scale, and in manipulating processes and products in which crystal nucleation and growth are key elements8. But there has been relatively little work on molecular-scale engineering at solid–solid Interfaces, despite their importance in polymeric composites for structured and electronic applications, in adhesives and in formulated pharmaceutical and agrochemical products. Here we report the use of molecules as tailored adhesives—a molecular ‘glue’ is selected to bond across an interfacial region and hence stabilize a solid–solid Interface. We consider a simple Interface occurring in a twinned crystal of saccharin; additive molecules with predictable dimensions and hydrogen-bonding functionality can span the Interface. The stabilization is reflected in an enhanced frequency of twin-crystal formation.

  • Stabilizing a solid–solid Interface with a molecular-scale adhesive
    Nature, 1999
    Co-Authors: Roger J. Davey, H. F. Lieberman, L. Williams-seton, Nicholas Blagden
    Abstract:

    The industrial importance of molecular materials chemistry has promoted great interest in areas such as self-assembled surface coatings1, multi-layer formation on solid substrates2, crystallization from solutions3, crystal morphology4 and structure prediction5, solving structures from powders6 and control of polymorphism7. Improvements in our understanding of the role of intermolecular interactions in driving molecular self-assembly and interfacial processes have led to technological advances—both in controlling the assembly of molecules at the nanometre scale, and in manipulating processes and products in which crystal nucleation and growth are key elements8. But there has been relatively little work on molecular-scale engineering at solid–solid Interfaces, despite their importance in polymeric composites for structured and electronic applications, in adhesives and in formulated pharmaceutical and agrochemical products. Here we report the use of molecules as tailored adhesives—a molecular ‘glue’ is selected to bond across an interfacial region and hence stabilize a solid–solid Interface. We consider a simple Interface occurring in a twinned crystal of saccharin; additive molecules with predictable dimensions and hydrogen-bonding functionality can span the Interface. The stabilization is reflected in an enhanced frequency of twin-crystal formation.

De Zhang - One of the best experts on this subject based on the ideXlab platform.

  • A Reflective Nonlinear Acoustic Microscope to Contour the Quantitative Adhesion at a Bonded Solid-Solid Interface
    Chinese Physics Letters, 2014
    Co-Authors: Jian Jun Chen, De Zhang
    Abstract:

    We set up a reflective nonlinear acoustic microscope to contour the quantitative adhesion at a bonded Solid-Solid Interface by a contact acoustic nonlinearity (CAN) method. The principle of the reflective nonlinear acoustic microscope is described. After the vibration amplitude of the incident, focusing wave at the bonded Interface is calculated, the standard adhesion with a complete bonding state is established by the tension test, the reflective CAN parameter is calibrated, and the quantitative contour of the adhesion at the Interface can be obtained. The experimental contours of two samples are also presented. Compared with the transmitted microscope, the reflective one is more convenient and more suitable for practical applications.

  • A can method to image the quantitative bonding strength at the bonded Solid-Solid Interface
    Piezoelectricity, Acoustic Waves and Device Applications (SPAWDA), 2012 Symposium on, 2012
    Co-Authors: Jian Jun Chen, De Zhang, Yi-wei Mao
    Abstract:

    As well known, when a longitudinal wave propagates through an Interface with micro-cracks and micro-defects between solids, the contact acoustic nonlinearity (CAN) will be generated dramatically and the nonlinear parameter can be used to contour the bonding state of the Interface. However the contour can only show the relative state of bonding strength and can not be used to judge weather the multilayered composite materials in use is safe because the safe judgment is not by the relative state while by the absolute value of the bonding strength. Therefore characterization of quantitative bonding strength at the Interface is very important for judging a multilayered material in safe use. In this paper, how to get the quantitative bonding strength from the CAN parameter is studied. After the vibration amplitude of incident focusing wave at the bonded Interface was calculated, the standard bonding strength with complete bonding state was established by tension test and CAN parameter is calibrated, the quantitative imaging of the bonding strength is obtained by CAN microscope in experiments. From the imaging, the positions with weak bonding strength could be easily located, which can be used to decide whether the material could be employed continuously.

  • contact acoustic nonlinearity in a bonded solid solid Interface
    Ultrasonics, 2006
    Co-Authors: Jian Jun Chen, De Zhang, Jianchun Cheng
    Abstract:

    Abstract We have conducted research on the contact acoustic nonlinearity (CAN) produced by a bonded solid–solid Interface in order to find a nondestructive and quantitative method to evaluate the bonding strength of the Interface. A CAN model is used to depict a bonded state from the relationship between the CAN parameter and the bonding strength and the crack width in the Interface. According to this model, a nondestructive evaluation of the bonding strength can be established. When the CAN parameter and the crack width are measured, the bonding strength can be calculated from the model. In this paper, the bonding strengths of some samples are evaluated based on the CAN method. The results well agree with the bonding strengths measured by hanging clogs (weights) to destroy their Interfaces.

  • Contact acoustic nonlinearity in a bonded solid–solid Interface
    Ultrasonics, 2006
    Co-Authors: Jian Jun Chen, De Zhang, Jianchun Cheng
    Abstract:

    Abstract We have conducted research on the contact acoustic nonlinearity (CAN) produced by a bonded solid–solid Interface in order to find a nondestructive and quantitative method to evaluate the bonding strength of the Interface. A CAN model is used to depict a bonded state from the relationship between the CAN parameter and the bonding strength and the crack width in the Interface. According to this model, a nondestructive evaluation of the bonding strength can be established. When the CAN parameter and the crack width are measured, the bonding strength can be calculated from the model. In this paper, the bonding strengths of some samples are evaluated based on the CAN method. The results well agree with the bonding strengths measured by hanging clogs (weights) to destroy their Interfaces.

  • An evaluation method of bonding strength at a bonded Solid-Solid Interface by contact acoustic nonlinearity
    IEEE Ultrasonics Symposium 2005., 2005
    Co-Authors: De Zhang, Jian Jun Chen
    Abstract:

    This paper presents a nondestructive method to evaluate the bonding strength of the Interface of bonded Solid-Solid. It is based on a contact acoustic nonlinearity (CAN) phenomenon produced by a bonded Solid-Solid Interface when a longitudinal wave propagates through the Interface. The CAN model is set up to depict a bonded state by the relationship between the bonding strength and the crack width in the Interface and the CAN parameter described by the ratio, 2 21 / AA , between the amplitudes of the second harmonic and fundamental waves. According to this model, a nondestructive evaluation of the bonding strength can be established. When the CAN parameter and the crack width are measured, the bonding strength can be evaluated from the model. In this paper, experiments have been done to demonstrate the model and the bonding strengths of some samples are evaluated based on the CAN method, The results (the example of 10.2kg/cm 2 by CAN model) are well agree with the bonding strengths (9.9 kg/cm 2 ) measured by hanging clogs to destroy their Interfaces.