Hydrogen is the lightest element in nature, and so, its detection and quantitative analysis is difficult by the conventional
methods utilized for other elements. In the recent years the technique of elastic recoil detection analysis (ERD) using 1–2
MeV He+ beam has been developed to quantitatively and simultaneously analyze hydrogen and its isotopes in solids. Such a facility
has been set up using the 2 MeV Van-de-Graaff accelerator at IIT Kanpur. It facilitates H and D analysis in a material up
to a depth of ∼ 1μm with a detection sensitivity of 0·1 at.% and depth resolution of about 300 ?. The application potential of this setup is
illustrated by presenting the results of measurements performed on Al:H:D systems prepared by plasma source ion implantation
and highTc YBCO pellets exposed to humid atmosphere. 相似文献
In the medical field, image segmentation is a paramount and challenging task. The head and vertebral column make up the central nervous system (CNS), which control all the paramount functions. These include thinking, speaking, and gestures. The uncontrolled growth in the CNS can affect a person’s thinking of communication or movement. The tumor is known as the uncontrolled growth of cells in brain. The tumor can be recognized by MRI image. Brain tumor detection is mostly affected with inaccurate classification. This proposed work designed a novel classification and segmentation algorithm for the brain tumor detection. The proposed system uses the Adaptive fuzzy deep neural network with frog leap optimization to detect normality and abnormality of the image. Accurate classification is achieved with error minimization strategy through our proposed method. Then, the abnormal image is segmented using adaptive flying squirrel algorithm and the size of the tumor is detected, which is used to find out the severity of the tumor. The proposed work is implemented in the MATLAB simulation platform. The proposed work Accuracy, sensitivity, specificity, false positive rate and false negative rate are 99.6%, 99.9%, 99.8%, 0.0043 and 0.543, respectively. The detection accuracy is better in our proposed system than the existing teaching and learning based algorithm, social group algorithm and deep neural network.
Research Summary Nanostructured ceramics and their composites possess improved properties such as tensile strength, fatigue
strength, hardness, and wear resistance. Freestanding, near-net shape, nanostructured Al2O3 components can be synthesized via plasma-spray forming. In this study, plasma-spray parameters were optimized and an innovative
substrate cooling technique was developed to retain nanosize Al2O3 in the spray deposit. Nanosize Al2O3 particles were partially melted and trapped between the fully melted coarser, micrometersize Al2O3grains. Densification of the spray-deposited Al2O3occurred via solidification and sintering. A similar processing approach can be adopted for fabrication of near-net shapes
of a variety of nanostructured materials (metals, ceramics, and intermetallics) and their combinations by selecting suitable
powder-treatment and plasmaspray parameters. 相似文献
In this paper, a novel pyramid coding based rate control scheme is proposed for video streaming applications constrained by a constant channel bandwidth. To achieve the target bit rate with the best quality, the initial quantization parameter (QP) is determined by the average spatio-temporal complexity of the sequence, its resolution and the target bit rate. Simple linear estimation models are then used to predict the number of bits that would be necessary to encode a frame for a given complexity and QP. The experimental results demonstrate that the proposed rate control scheme significantly outperforms the existing rate control scheme in the Joint Model (JM) reference software in terms of Peak Signal to Noise Ratio (PSNR) and consistent perceptual visual quality while achieving the target bit rate. Finally, the proposed scheme is validated through experimental evaluation over a miniature test-bed.
Experimental validation of numerical models developed by the authors to predict the static behaviour of microelectrostatic
actuators is described. Cantilever microbeams, currently used in connection with RF-MEMS and micro-scale material testing
were analysed. A set of microcantilevers, bending in the plane of the wafer, i.e. in the same plane as the profiling system’s
target, was tested. This differs from the popular case of out-of-plane microbeams, usually studied in the literature. Geometry
nonlinearity caused by large deflection of the microbeam was investigated and nonlinear coupled formulation of electromechanical
equilibrium was performed. Coupled-field analysis was implemented using the Finite Element Method (FEM), to predict displacements
and pull-in voltage measured by Fogale Zoomsurf 3D, subsequently plotting the displacement-versus-voltage curve to complete
model validation. FEM nonlinear analysis, based on iterative approach with mesh morphing, and FEM non-incremental approach,
including a special element proposed by the authors, are compared to the linear solution and to experimental results. Geometry
nonlinearity appears relevant in microbeam modelling and requires a nonlinear solution of the coupled problem. Investigative
work, which compared the results of 2D and 3D models to experimental data, revealed that some three dimensional effects are
significant in model validation, but the 2D approach may be effective in predicting static behaviour provided that at least
a microbeam thickness equivalent is adopted. 相似文献
We investigate the role of interfacial slip on evaporation of a thin liquid film in a microfluidic channel. The effective
slip mechanism is attributed to the formation of a depleted layer adhering to the substrate–fluid interface, either in a continuum
or in a rarefied gas regime, as a consequence of intricate hydrophobic interactions in the narrow confinement. We appeal to
the fundamental principles of conservation in relating the evaporation mechanisms with fluid flow and heat transfer over interfacial
scales. We obtain semi-analytical solutions of the pertinent governing equations, with coupled heat and mass transfer boundary
conditions at the liquid–vapor interface. We observe that a general consequence of interfacial slip is to elongate the liquid
film, thereby leading to a film thickening effect. Thicker liquid films, in turn, result in lower heat transfer rates from
the wall to liquid film, and consequently lower mass transfer rates from the liquid film to the vapor phase. Nevertheless,
the total mass of evaporation (or equivalently, the net heat transfer) turns out to be higher in case of interfacial slip
due to the longer film length. We also develop significant physical insights on the implications of the relative thickness
of the depleted layer with reference to characteristic length scales of the microfluidic channel on the evaporation process,
under combined influences of the capillary pressure, disjoining pressure, and the driving temperature differential for the
interfacial transport. 相似文献
This paper describes novel implementations of the KLT feature tracking and SIFT feature extraction algorithms that run on
the graphics processing unit (GPU) and is suitable for video analysis in real-time vision systems. While significant acceleration
over standard CPU implementations is obtained by exploiting parallelism provided by modern programmable graphics hardware,
the CPU is freed up to run other computations in parallel. Our GPU-based KLT implementation tracks about a thousand features
in real-time at 30 Hz on 1,024 × 768 resolution video which is a 20 times improvement over the CPU. The GPU-based SIFT implementation
extracts about 800 features from 640 × 480 video at 10 Hz which is approximately 10 times faster than an optimized CPU implementation. 相似文献
Summary Theoretical and experimental analyses have been carried out for determining the injection condition below which the formation of air core does not take place in the course of flow of a time-independent power-law fluid through a swirl nozzle. Analytical solution lends one distinct value of generalized Reynolds number at the inlet to a nozzle below which the air core is not formed. Experiments reveal that there exist two limiting values of such generalized Reynolds number regarding the formation of air core in a nozzle. One value being the upper limit below which steady flow occurs without air core, the other one is the lower limit above which steady flow with fully developed air core persists. In between these two limiting values, there prevails a transition zone through which fully developed air core is set up within the nozzle. For all the nozzles, theoretical results are in fair agreement with the experimental values of upper limit of generalized Reynolds numbers with respect to steady flow without air core. Amongst all the pertinent independent geometrical parameters of a nozzle, the orifice-to-swirl chamber-diameter ratio has the remarkable influence on generalized Reynolds number describing the initiation of air core.Nomenclature
D1
Swirl chamber diameter
-
D2
Orifice diameter
-
Ds
Diameter of tangential entry ports
-
E
A non-dimensional parameter defined by Eq. (9)
-
ER
A non-dimensional parameter defined by Eq. (25)
-
K
Flow consistency index
-
L1
Length of the swirl chamber
-
n
Flow behaviour index
-
P
Static pressure inside the nozzle
-
Pb
Back-pressure of the nozzle
-
Q
Volume flow rate
-
R
Radius vector or longitudinal coordinate with respect to spherical coordinate system (Fig. 3)
-
R1
Radius of the swirl chamber
-
R2
Radius of the orifice
-
Generalized Reynolds number at the inlet to the nozzle
-
Limiting value of generalized Reynolds number describing initiation of air core
-
Rz
Radius at any section
-
r
Radial distance from the nozzle axis
-
ra
Air core radius
-
u
Longitudinal component of velocity with respect to spherical coordinate system (Fig. 3)
-
Vr
Radial velocity component
-
Vz
Axial velocity component
-
V
Tangential velocity component
-
Tangential velocity at inlet to the nozzle
-
v
Component of velocity in the axial plane perpendicular toR (Fig. 3)
-
w
Component of velocity perpendicular to axial plane with respect to the spherical coordinate system (Fig. 3)
-
z
Distance along the nozzle axis from its inlet plane
-
Half of the spin chamber angle
-
Boundary layer thickness measured perpendicularly from the nozzle wall
- 2
Boundary layer thickness at the orifice
-
Angle, which a radius vector makes with the nozzle axis, in spherical coordinate system (Fig. 3)
-
Density of the fluid
-
Running coordinate in the azimuthal direction with respect to the cylindrical polar coordinate system as shown in Fig. 3
-
Circulation constant
With 8 Figures 相似文献