Search

Non-uniform deformation of the dielectric subjected to external forces can induce the flexoelectric effect, a phenomenon that couples electrical polarization to strain gradients. However, limited by the size effects, flexoelectricity is not significant at the macroscale and only becomes catchable at the microscale and nanoscale. In recent work, we obtained a considerable flexoelectric-like response by crumpling the dielectric embedded with charges, i.e., the electret, which significantly improved the flexoelectric effect at the macroscale. In this work, we further optimize the macroscopic performance of the flexoelectric response by applying gradient treatment to the electret films. Specifically, we analytically derive the electromechanical coupling of crumpled electret films with gradients of different thicknesses, charge densities, and Young's moduli as key design variables. It is shown that the gradient-oriented electret film can be tuned to nearly five times that of a uniform electret film. [ABSTRACT FROM AUTHOR]

The present study aims to describe the role of the grain size on the properties of submicron- and nano-structured Ba 0·8 Sr 0·2 TiO 3 (BST) ceramics. Dense (1 − 2% porosity) ceramics with average grain sizes in the range of (77 − 234) nm were consolidated under different spark plasma sintering conditions starting from nanopowders with a mean particle size of 70 nm, synthesized via the acetate variant of the sol-gel method. The structural analysis based on XRD data revealed a mixture of cubic and tetragonal modifications at room temperature for the precursor powders and for all the investigated ceramics. The structural heterogeneity of the individual ceramic grains with coexistence of cubic and tetragonal polymorphs was confirmed by HR-TEM investigations. Accordingly, a "brick-wall" model with cubic grain boundary regions and tetragonal grain cores is proposed. By increasing the grain size, from 77 to 234 nm, a decrease of the phase transitions diffuseness accompanied by an increase of the permittivity maxima (from 650 to 4500) and dielectric losses (from 5 to 7.5%, at 100 Hz), was detected by broadband dielectric spectroscopy. No variation of the Curie temperature in the investigated Ba 0·8 Sr 0·2 TiO 3 ceramics was detected, unlike typically reported for BaTiO 3 ceramics with similar grain sizes. The Curie-Weiss temperature and the Curie constant decrease when grain size is diminished, indicating an overall reduction of the ferroelectric active volume, as a scaling effect. The ferroelectric switching was demonstrated for all the selected fine-grained BST ceramics, either at nanoscale or macroscopically, with an increased ferroelectric character for the coarser submicron-structured ceramics, with respect to the nanocrystalline one. The observed properties of the fine-grained Ba 0·8 Sr 0·2 TiO 3 ceramics are explained in the frame of multiphase coexistence and ferroelectricity "dilution" due to the increasing role of non-ferroelectric grain boundaries when reducing grain size and complete the knowledge on the scale-dependent properties of dense fine-grained BaTiO 3 -based ceramics. [Display omitted] • Ultra dense fine-grain Ba 0·8 Sr 0·2 TiO 3 (BST) ceramics with low losses are obtained by Spark Plasma Sintering (SPS). • The multiphase coexistence broadens with reducing grain size from 234 to 77 nm. • "Brick-wall"-like grains with cubic non-ferroelectric grain boundaries and tetragonal ferroelectric cores were found. • As decreases, the thermal stability of the dielectric response increases, while the Curie temperature is invariant. • Ferroelectric switching is found even in the nanocrystalline ( = 77 nm) BST ceramic. • All the functional properties of the fine-grained BST ceramics are influenced by . [ABSTRACT FROM AUTHOR]

Location quotients (LQ) are a transformation of raw data stored in contingency tables. This transformation has been used frequently in studies involving international trade (under the name 'revealed comparative advantage') and in multiple other settings where a total can be disaggregated under at least two independent criteria and thus arranged in a cross sectional table: eg. employment by industry and city, etc. The spread of LQ values is influenced by row, column and table totals, which prevents us from comparing LQ levels safely across entities, over time or between datasets. This issue dramatically undermines the usefulness of the location quotient transformation. In this paper I offer viable paths for characterizing these so-called size distortions in location quotients. [ABSTRACT FROM AUTHOR]

Abstract Free-form surfaces and micro features are finish machined by a micro ball end mill by removing steps left behind by flat end mill in the previous operation. For effective machining, off-centre ball end milling is employed in such a way that rubbing zone near ball tip is avoided. After confirming the limits of angular immersion from full-slot experimental results, both down and up off-centre milling experiments are conducted on edges of steps created on a test piece. The micro milling forces in off-centre mode are also investigated theoretically using a mechanistic model that considers the geometry of micro ball end mill and basic mechanics of cutting. The amplitudes of predicted forces match well with experimental values and the deviations in the experimental values arise out of micro level unevenness in the step edge. The up milling with lower transverse force is found to be more suitable for machining of thin features. [ABSTRACT FROM AUTHOR]

In this article, an analytical solution to the moderately large amplitude transverse vibration of thin Functionally Graded Micro-Plates (FGMPs) is presented based on a practical approach. The size-dependent nonlinear governing equation is obtained in conjunction with the Kirchhoff's plate and modified couple stress theories. The material properties of Functionally Graded (FG) micro-plates vary according to the Reddy's model. The employed non-classical theory contains one material length-scale parameter to capture the size effects. The highly nonlinear governing equation is solved by means of homotopy analysis method so as to obtain accurate analytic approximations. Both of simply supported and clamped micro-plates with immovable edges are considered. The comparison made between the present results and those of earlier studies confirms the reliability and effectiveness of the present formulation for the design purpose. Furthermore, the effects of different parameters, such as material gradient index, length-scale parameter, and aspect ratio, on the nonlinear frequency ratio are investigated. [ABSTRACT FROM AUTHOR]

Micro hydroforming is promising for fabricating complex micro components with a high aspect ratio. The aim of this study is to deepen the understanding of the size effects in micro hydroforming. Experimental work and FEM simulations of micro hydro-mechanical deep drawing (MHDD) were conducted. Voronoi model and real microstructure model were established. Real grain morphology can be considered in the real microstructure model. Local thinning in critical area of the drawn cups due to size effects can be predicted by the models. The simulation results agree with the MHDD test results. [ABSTRACT FROM AUTHOR]

Although it was recently determined that silicon can alleviate cadmium (Cd) toxicity in rice, the effects of silicon properties and the molecular mechanisms are still unclear. Here, the effect of silica nanoparticles (SiNPs) on Cd toxicity in rice was examined using cells cultured in suspension in the presence or absence of SiNPs (19 nm, 48 nm and 202 nm). The results showed that the presence of SiNPs substantially enhanced the proportion of live cells to 95.4%, 78.6% and 66.2%, respectively, suggesting that the extent of alleviation of Cd toxicity decreased gradually with size of SiNPs. The morphological results showed that dramatic damage and severe structural changes in the organelle integrity of cells occurred in the absence of SiNPs, whereas the cells exposed to the SiNPs remained nearly intact even in the presence of high concentrations of Cd. Furthermore, the SiNPs accumulated on the surface of the rice cells. Using inductively coupled plasma mass spectroscopy, Cd accumulated preferentially in plant cells with cell walls. In addition, noninvasive microtest technology showed that the average Cd 2+ influx in those treated with SiNPs (19 nm, 48 nm and 202 nm) decreased by 15.7-, 11.1- and 4.6-fold, respectively. The gene expression of Cd uptake and transport ( OsLCT1 and OsNramp5 ) was inhibited by SiNPs, but the gene expression of Cd transport into vacuole ( OsHMA3 ) and Si uptake ( OsLsi1 ) was enhanced by the SiNPs. These results indicate that the presence of SiNPs increased at least 1.87-fold the Si uptake capacity and inhibited the Cd uptake capacity, which together resulted in the alleviation of the toxicity of Cd in rice. This study provided a molecular-scale insight into the understanding of the SiNPs-induced alleviation of the toxicity of Cd in rice. [ABSTRACT FROM AUTHOR]

Ultrasonic Pulse Velocity (UPV) method is a very popular technique used in Non-Destructive Testing (NDT) in Civil Engineering. Major benefit of the method is its simplicity. UPV uses the concept of measuring time of a first arrival of ultrasonic wave from one side of the specimen to another. Moreover, UPV is an ASTM standard test method for concrete specimens. The standard specifies the applications of UPV as: assessment of relative quality of concrete, presence of imperfections (i.e. voids, cracks, and the effectiveness of its repairs). UPV can be also applied to monitoring changes in the condition of a specimen. In spite of an easiness of the method the obtained results highly depend on the transducers used, the coupling quality, and the specimen dimensions. In this article the authors focus on the sensor and the dimensions effects. The results for UPV tests on 9 mortar specimens of different heights and diameters are presented. The specimens are tested with 54 kHz and 850 kHz resonant frequency (fc) transducers and the state-of-the-art laser vibrometer (response measurements). The authors discuss the laser vibrometer readings and the influence of specimens’ dimensions on the measured pulse velocities. Practical recommendations for the minimal dimensions of the test object in order to minimize the error in the UPV tests are proposed. [ABSTRACT FROM AUTHOR]

Carbon nanotubes are a new class of microtubule-stabilizing agents since they interact with protein microtubules in living cells, interfering with cell division and inducing apoptosis. In the present work, a modified beam model is developed to investigate the effect of carbon nanotubes on the buckling of microtubule bundles in living cell. A realistic interaction model is employed using recent experimental data on the carbon nanotube-stabilized microtubules. Small scale and surface effects are taken into account applying the nonlocal strain gradient theory and surface elasticity theory. Pasternak model is used to describe the normal and shearing effects of enclosing filament matrix on the buckling behavior of the system. An exact solution is obtained for the buckling growth rates of the mixed bundle in viscoelastic surrounding cytoplasm. The present results are compared with those reported in the open literature for single microtubules and an excellent agreement is found. Finally, the effects of different parameters such as the size, chirality, position and surface energy of carbon nanotubes on the buckling growth rates of microtubule bundles are studied. It is found that the buckling growth rate may increase or decrease by adding carbon nanotubes, depending on the diameter and chirality of carbon nanotubes. [ABSTRACT FROM AUTHOR]

This paper presents a three-dimensional finite element approach to incorporate microstructure into micro cutting simulation based on the concept of a representative volume element (RVE) and constitutive material modeling as well as using the Lagrangian formulation proposed in the implicit FE code Deform 3D TM . Finish broaching, micro milling and micro drilling tests using solid carbide tools with different cutting parameters are performed on ferrite-pearlite two-phase steel AISI 1045 for the verification of the developed 3D multiphase FE computation model regarding chip formation and cutting forces. The developed 3D multiphase FE model is successfully used to predict size effects in micro cutting. [ABSTRACT FROM AUTHOR]

Compare with TiO 2 , Cu 2 O has higher conduction and valence bands. Combined with TiO 2 they may form p–n heterojunction structure so as to improve the photocatalytic efficiency. In this paper Cu 2 O-loaded TiO 2 nanoparticles (Cu 2 O/TiO 2 ) were prepared by ultrasonication-assisted penetrate precipitation method. The catalysts were characterized by TEM, SEM, XRD, XPS, PL etc., The photocatalytic degradation kinetics of Cu 2 O-loaded TiO 2 nanoparticles on methylene blue were systematically investigated. Experiment show that high loading Cu 2 O in Cu 2 O/TiO 2 material by penetrate precipitation process result in the appearance of large Cu 2 O nanoparticles size in the TiO 2 surface, and consequently decreased the photocatalysis performance. The Cu 2 O particle size effects on the absorption band edge and photo induced catalytic performance were also investigated. [ABSTRACT FROM AUTHOR]

• This paper investigated the size effect of silicon-based AlGaInP red micro-LEDs. • Smaller micro-LEDs can alleviate the high-current efficiency droop. • Sidewall passivation can suppress the size effect of the micro-LED. • This research provides important data for designing and fabricating red micro-LEDs. To study the size effect of AlGaInP red micro-LEDs on the silicon substrate, we fabricated five AlGaInP red micro-LEDs with different pixel sizes (160 × 160, 80 × 80, 40 × 40, 20 × 20, and 10 × 10 µm2) and studied their electrical and optical properties. Smaller micro-LEDs have smaller leakage current and larger series resistance and can withstand higher current density without the current crowding effect. Due to the larger perimeter-to-area ratio of small-sized micro-LEDs, non-radiative recombination increases, which leads to a lower EQE. But smaller micro-LEDs can alleviate the problem of the high-current efficiency droop. In addition, because of a better heat dissipation under a high injection current, smaller micro-LEDs (>80 µm) have a smaller center wavelength shift. These experimental results provide important data for designing and fabricating red micro-LEDs with different pixel sizes for diverse future applications. [ABSTRACT FROM AUTHOR]

Friction at the workpiece-die interface significantly affects material flow behaviours in micro metal-forming processes. The purpose of this study was to estimate the friction factor at the workpiece-die interface in the combined forward and backward hollow extrusion of brass at micro scale. The effects of grain size and lubricating conditions on the friction were investigated. The brass (JIS C2700) tubes with 1·1 mm outer diameter and 0·5 mm inner diameter were annealed at 400, 500 and 600°C, and resulted in various microstructures with grain sizes of 20, 34 and 80 μm, respectively. The tubes were fabricated as 0·6 mm length specimens for the experiments of the hollow extrusion under dry, full and punch lubricated conditions. By comparing the ratios of the cup height to the rod length of the extruded specimens with the calibration curves established by finite element simulations, it is possible to estimate the friction factors in the processes. The results show that dry conditions lead to stronger friction effects and thus larger friction factors. The friction factor increased with grain size and stroke for all conditions. The estimated friction factors were in a range from 0·1 to 0·35. [ABSTRACT FROM AUTHOR]

The deformation behavior of metal sheets is strongly influenced by the extent of miniaturization due to the size effects (specimen size and grain size). In this paper, the effect of thickness and grain size on the flow stress of very thin brass sheets has been investigated by conducting microstructural studies and uni axial tensile tests on annealed specimens of thickness in the range 50 μm-200 μm.To obtain a large variation in thickness to grain size (t/d) ratio, different combinations of annealing temperature and time have been chosen. The effect of t/d ratio on yield stress and flow stress has been analysed using the tensile test data. For larger values of t/d ratio (6 -18), yield strength and flow stress at different strain levels increased with increase in t/d ratio. But flow stress decreases with increasing t/d when the values of t/d ratio are less than 3 due to the size effects. [ABSTRACT FROM AUTHOR]

Friction at the workpiece-die interface significantly affects material flow behaviours in micro metalforming processes. The purpose of this study was to estimate the friction factor at the workpiece-die interface in the combined forward and backward hollow extrusion of brass at micro scale. The effects of grain size and lubricating conditions on the friction were investigated. The brass (JIS C2700) tubes with 1·1mm outer diameter and 0·5mm inner diameter were annealed at 400, 500 and 600°C, and resulted in various microstructures with grain sizes of 20, 34 and 80 μm, respectively. The tubes were fabricated as 0·6mm length specimens for the experiments of the hollow extrusion under dry, full and punch lubricated conditions. By comparing the ratios of the cup height to the rod length of the extruded specimens with the calibration curves established by finite element simulations, it is possible to estimate the friction factors in the processes. The results show that dry conditions lead to stronger friction effects and thus larger friction factors. The friction factor increased with grain size and stroke for all conditions. The estimated friction factors were in a range from 0·1 to 0·35. [ABSTRACT FROM AUTHOR]

Hydrothermally synthesized one-dimensional and two-dimensional nanocrystals of VO2 undergo phase transition around 65°C, where temperature and mechanism of phase transition are dependent on dimensionality of nanocrystals. Both nanocrystalline samples exhibit depression of phase transition temperature compared to the bulk material, the magnitude of which depends on the dimensionality of the nanocrystal. One-dimensional nanoribbons exhibit lower phase transition temperature and higher values of apparent activation energy than two-dimensional nanosheets. The phase transition exhibits as a complex process with somewhat lower value of enthalpy than the phase transition in the bulk, probably due to higher proportion of surface atoms in the nanocrystals. High values of apparent activation energy indicate that individual steps of the phase transition involve simultaneous movement of large groups of atoms, as expected for single-domain nanocrystalline materials. [ABSTRACT FROM AUTHOR]

Abstract: Nano-sized (nO-Co3O4, 387nm) and micron-sized (mO-Co3O4, 6.65μm) Co3O4 octahedra enclosed by {111} facets have been both synthesized through a wet chemical method followed by thermal treatment, and served as anode material of lithium ion batteries (LIBs). Electrochemical results demonstrate that the nO-Co3O4 shows excellent long cyclability and rate capability. The nO-Co3O4 can deliver a stable charge capacity as high as 955.5mAhg−1 up to 200 cycles without noticeable capacity fading at a charge/discharge current density of 0.1Ag−1 (ca. 0.11C). The excellent electrochemical performance is ascribed to the nano-size and the {111} facets that enclose the octahedra. While the mO-Co3O4 could only maintain 288.5mAhg−1 after 200 cycles, illustrating very poor cycling performance, which is ascribed to the large particle size that may cause huge volume change during repeated charging/discharging process. The results reveal that the Co3O4 nano-octahedra would be a promising anode material for the next-generation of LIBs. [Copyright &y& Elsevier]

Abstract: Micro-manufacturing has received good attention globally in terms of its manufacturing methods/processes. One of the most popular micro-manufacturing processes is micro-forming. Many efforts have been focused on micro-forming, mainly on the micro-stamping process due to the process itself contributing numerous products, especially in its conventional macro-process. Most every-day products are made by this process. Although there were efforts made to realize micro-forming for industrial application, the technology itself was seen as being insufficiently mature. Much development work needed to be done, specifically to develop a fully-automated high-volume production micro-forming machine, which is reliable and at all times ready for operation in terms of it processes, tooling, and material-handling to ensure the successful production of micro-products. The paper addresses key issues encountered by researchers worldwide on both micro-manufacturing, specifically micro-forming. [Copyright &y& Elsevier]

Abstract: A dynamic analysis of an elastic gradient-dependent polymeric fiber subjected to a periodic excitation is considered. A nonlinear gradient elasticity constitutive equation with strain–dependent gradient coefficients is first derived and the dispersive wave propagation properties for its linearized counterpart are briefly discussed. For the linearized problem a variational formulation is also developed to obtain related boundary conditions of both classical (standard) and non-classical (gradient) type. Analytical solutions in the form of Fourier series for the fiber''s displacement and strain fields are provided. The solutions depend on a dimensionless scale parameter (the diameter to length radio d = D/L) and, therefore, size effects are captured. [Copyright &y& Elsevier]

Abstract: The geometry and stability of the Au m Pd n bimetallic cluster have been studied using density functional theory with the GGA-PW91 exchange–correlation functional. A series of Au m Pd n (N =38, 55, 79, N = m + n, m/n ≈2:1 and 5:1) bimetallic clusters with truncated octahedral shape was used to model such bimetallic nanosystems. The excess energy of two ratios configurations demonstrates that the m/n ≈2:1 ratio of Au m Pd n clusters is more stable than the m/n ≈5:1 ratio. The excess energy order of Au m Pd n clusters with the m/n ≈2:1 ratio is Au24Pd14 >Au52Pd27 >Au36Pd19, which shows a complicated size dependency. The Au24Pd14 cluster for N =38 is the most stable bimetallic geometry. Hirshfeld charges and electron density difference show that the charge transfers from the Pd atoms to the Au atoms associated with the ionic feature of Au–Pd bonds. The PDOS, IP and EA show the sensitivity to Au:Pd ratio and cluster size N of AumPdn clusters. Such nanocrystallites are expected to exhibit peculiar catalytic properties and should be prone to retaining their initial shape under catalytic conditions due to the thermodynamically stability. [Copyright &y& Elsevier]

The article focuses on the study of school performance in Thailand by using data envelopment analysis which is a non-parametric technique. The important factors that affect student achievement include shared vision between principals and teachers and sizes like class size and school size. A model derived from substantial literature was proposed.

Abstract: The main objective of this research work is to investigate size effects by down scaling the twist drilling process into the micro range (drill diameter: d = 50μm – 1mm). Therefore, experimental micro drilling tests in ferritic-pearlitic carbon steel C45 are performed with different cutting parameters and compared with data obtained from conventional drilling. Based on the concept of a representative volume element (RVE) and constitutive material modelling, as well as using the Lagrangian formulation proposed in the implicit FE code Deform 3DTM, a 3D multiphase FE computational model was successfully applied to predict size effects in micro drilling. [Copyright &y& Elsevier]

Abstract: Deep drawing provides a great application potential for the manufacturing of parts with complex shapes, even in very small dimensions. The friction between blank and forming tool is one of the decisive affecting factors for this process, since it affects the punch force as well as the surface quality of drawn workpieces essentially. Using scaled deep drawing it was found in our previous works, that the friction coefficients increase significantly with decreasing process dimension. This is called tribological size effect, which must be taken into account during the development of micro deep drawing. In this work, the tribological size effect is further investigated in deep drawing of work pieces with more complicated geometry, i.e. rectangular cups. In this investigation, scaled experiments are carried out with different rectangular punches (from 1.5×0.75mm2 to 20×10mm2) and the blank material Al99.5 with different thicknesses (from 0.015mm to 0.2mm). Size dependent FEM-simulation for this process is performed, at which the friction functions from scaled deep drawing of circular parts in previous work are applied. The comparison of both the simulated and experimental punch force-stroke-curves shows that the friction functions from deep drawing of circular parts is also valid for the deep drawing of rectangular work pieces. The size-dependent FEM-simulation with application of friction functions can be used to determine an optimum blank shape for a flange free rectangular micro workpiece (punch 2×1mm2), which is later validated in experimental investigation. [Copyright &y& Elsevier]

Abstract: In the current investigation, the effect of specimen size in a Kolsky Bar experiment has been analyzed. By a series of experiments, it has been shown that while determining the dynamic stress-strain relationship of a material using a non-cylindrical specimen, a judicious choice of specimen dimensions helps overcome size effects and estimates the flow stress of the material with reasonable accuracy. Similarly a dependence of the strength of the joint on the overlap area has been observed while finding the dynamic strength of an adhesive-bonded single-lap joint. [Copyright &y& Elsevier]

Abstract: In the current investigation, the effect of specimen size in a Kolsky Bar experiment has been analyzed. By a series of experiments, it has been shown that while determining the dynamic stress-strain relationship of a material using a non-cylindrical specimen, a judicious choice of specimen dimensions helps overcome size effects and estimates the flow stress of the material with reasonable accuracy. Similarly a dependence of the strength of the joint on the overlap area has been observed while finding the dynamic strength of an adhesive-bonded single-lap joint. [Copyright &y& Elsevier]

Abstract: Nacre, the iridescent material found in Abalone shells, exhibits remarkable strength and toughness despite its composition of over 95% brittle ceramic. Its hierarchical structure over multiple length scales gives rise to its increase in toughness despite its material composition. In this work we develop a computational model of composites incorporating key morphological features of nacre’s microstructure. By conducting a parametric analysis we are able to determine an optimal geometry that increases energy dissipation over 70 times. We discuss the contribution of varying ceramic strengths and size effect to see how this affects the overall performance of the composite. We then compare our simulations to experiments performed on a material possessing the same microstructure investigated computationally. For both simulations and experiments we show that our optimal geometry corresponds to that of natural nacre indicating the importance of specifically incorporating nacre’s key morphological and constituent features. This combination of simulations and experiments gives great insight to the delicate interplay between material parameters and microstructure showing that if we optimally combine all aspects, we can develop novel synthetic materials with superior performance. [ABSTRACT FROM AUTHOR]

Abstract: Lasers offer a reproducible and controllable energy input into a highly localized area. This enables lasers as flexible forming tools. Although mechanisms of laser forming are known in principle, the application of laser forming is limited due to a lack of understanding of the quantitative process analysis. The presented article shows how laser forming processes can overcome the limits of conventional thermal forming by means of laser shock forming and laser assisted free head forming. Furthermore a concept is presented how to optimize a thermal forming process with the help of scaling rules. [Copyright &y& Elsevier]

Abstract: Finite element simulations of continuous chip formation have been carried out over a range of uncut chip thicknesses from 0.002 to 0.25mm and for tools with cutting edge radii from 5 to 160μm, using material models for annealed or normalised medium carbon steels. Expressions are derived for the dependence of ploughing forces on edge radius, uncut chip thickness and chip shear plane angle and flow stress. Non-linearity of force variation with uncut chip thickness is demonstrated, in addition to what might result from ploughing, caused by variations of temperature and strain-rate and hence of work material shear flow stress. These ploughing and non-linearity effects quantitatively account for the well-known size effects associated with machining, certainly for the machining of steels. There is no need to include ductile fracture energy from forming fresh surfaces in models of continuous chip formation in order to account for the size effect. [ABSTRACT FROM AUTHOR]

Large developing economies demonstrate an upward trend in many aspects of their macroeconomic performance in recent decades. This developmental surge is attributed to 'size effects' whereby economies of scale and scope, and agglomeration impact, create productivity improvements. The transmission channels from finance to growth are discussed to show how size effects can affect this transmission channels in terms of specific features in four typical developing countries. The empirical estimation concentrates on econometric regressions for these specific large developing countries -- Brazil, India, China and South Africa, involving analyzing dynamic shocks from investment, trade and financial growth, together with several variables of indicating sire -- effect: education investment, government spending, and military expenditures. [ABSTRACT FROM AUTHOR]

Abstract: Size matters in banking. In this paper, we explore whether shocks originating at large banks affect the probability of distress of smaller banks and thus the stability of the banking system. Our analysis proceeds in two steps. In a first step, we follow Gabaix [Gabaix, X., 2008a. The Granular Origins of Aggregate Fluctuations. Available at SSRN: http://ssrn.com/abstract=1111765] and construct a measure of idiosyncratic shocks at large banks, the so-called Banking Granular Residual. This measure documents the importance of size effects for the German banking system. In a second step, we incorporate this measure of idiosyncratic shocks at large banks into an integrated stress-testing model for the German banking system following De Graeve et al. (2008). We find that positive shocks at large banks reduce the probability of distress of small banks. [Copyright &y& Elsevier]

Abstract: In manufacturing of metallic components, the size of the part plays an important role for the process behaviour. This is due to so called size effects, which lead to changes in the process behaviour even if the relationship between the main geometrical features is kept constant. The aim of this paper is to give a systematic review on such effects and their potential use or remedy. First, the typology of size effects will be explained, followed by a description of size effects on strength and tribology. The last three sections describe size effects on formability, forming processes and cutting processes. [Copyright &y& Elsevier]

Copyright of BMS: Bulletin de Méthodologie Sociologique (l'Association Internationale de Méthodologie Sociologique (AIMS)) is the property of l'Association Internationale de Methodologie Sociologique (AIMS) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An experimental and numerical research was conducted to gain a deeper insight on the structural behaviour of deep-beams with indirect supports and to assess the size effects in the ultimate state behaviour. The experimental campaign focused on the influence of the reinforcement tie distribution height on the compression check of the support region and on the benefits of using unbonded prestressing steel. Three reduced scale specimens were tested and used to validate the results obtained with a nonlinear finite element model. As a good agreement could be found between the numerical and the experimental results, the numerical model was then further used to perform simulations in large scale deep-beams, with dimensions similar to the ones to be adopted in a practical case. Two sources of size effects were identified from the simulation results. Both sources are related to the concrete quasi-brittle behaviour and are responsible for increasing failure brittleness with increasing structural size. While in the laboratory models failure occurred both in the experimental tests as well as iii the numerical simulations after reinforcement yielding, the numerically analysed large scale models exhibited shear failures with reinforcement still operating in the elastic range. [ABSTRACT FROM AUTHOR]

The enhanced gradient plasticity theories formulate a constitutive framework on the continuum level that is used to bridge the gap between the micromechanical plasticity and the classical continuum plasticity. The later cannot predict the size effects since it does not posses an intrinsic length scale. To assess the size effects, it is indispensable to incorporate an intrinsic material length parameter ... into the constitutive equations. However, the full utility of gradient-type theories hinges on one's ability to determine the constitutive length-scale parameter ... that scales the gradient effects. Thus, the definition and magnitude of the intrinsic length scale are keys to the development of the new theory of plasticity that incorporates size effects. The classical continuum plasticity is also unable to predict properly the evolution of the material flow stress since the local deformation gradients at a given material point are not accounted for. The gradient-based flow stress is commonly assumed to rely on a mixed type of dislocations: those that are initially randomly or statistically distributed, which are referred to as statistically stored dislocations (SSDs). and those formed to account for the additional strengthening mechanism associated with the deformation gradients, which are referred to as geometrically necessary dislocations (CNDs). In this work two micromechanical models to assess the coupling between SSDs and CNDs are discussed. One in which the SSDs and CNDs are simply summed (model-I) and one in which, implicitly, their accompanying strength are added (model-II). These two dislocation interaction models, which are based on Taylor's hardening law, are then used to identify the deformation-gradient-related intrinsic length-scale parameter in terms of measurable microstructural physical parameters. The paper also presents a method for identifying the material intrinsic length parameter from micro hardness results obtained by conical or... [ABSTRACT FROM AUTHOR]

Composite materials show significant variability in strength, which means that statistical effects need to be considered when predicting failure. Experimental results are presented which show decreasing strength with increasing stressed volume of material. Approaches accounting for this in predicting strength using Weibull statistics are discussed. [ABSTRACT FROM AUTHOR]

An abstract of the article "Effect of Sample Size and Testing Temperature on the Fracture Toughness of Ti3SiC2" by Yi-Wang Baa and Yan-Chun Zhou is presented.