1,033 research outputs found

    Reliability Analysis of a Series and Parallel Network using Triangular Intuitionistic Fuzzy Sets

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    This paper describes a novel approach, based on intuitionistic fuzzy set theory for reliability analysis of series and parallel network. The triangular intuitionistic fuzzy sets are used to represent the failure possibility of each basic (terminal) event to get more comprehensive results for the failure possibility of the top event. The proposed technique is demonstrated on a web server LOG data used to illustrate HTTP (Hyper Text Transfer Protocol) failur

    Triplication of Deciduous Teeth: A Rare Dental Anomaly

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    Fusion of teeth is the union of two or more tooth germs, which are usually separated. Depending upon the stage of odontogenesis, it can be complete or incomplete. The present case describes fusion between the maxillary  primary right central and lateral incisor with a supernumerary tooth. Clinical and radiographic examination revealed the presence of fused triple teeth. The fused teeth were extracted, sectioned and were visualized under  stereomicroscope at three levels and the diagnosis of fusion of three teeth was confirmed histologically.Keywords: Fusion, primary teeth, supernumerary tooth, triple teet

    Ultrasonographic Examination of the Rumen in Healthy Cows

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    10 healthy Indian Jersey/Red Sindhi crossbred nonpregnant cows were subjected to transabdominal ultrasonography to develop baseline topographical data of the rumen. The wall of the rumen could be identified as a thick echogenic line adjacent to the left abdominal wall from left flank to 8th intercostal space. The motility pattern of rumen was characterized by approximately 1 contraction every minute. The mean amplitude of the ruminal contraction was 3.2 cm. Ultrasonography of the rumen in healthy cows is a useful adjunct to the noninvasive diagnostic investigation of the rumen

    Ultrasonographic Imaging of Normal and Impacted Omasum in Indian Crossbred Cows

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    Omasal impaction is a serious disease problem in cattle in India, but it is difficult to diagnose clinically. Ultrasonography has been proposed for the noninvasive evaluation of omasal disease. The objectives of this study were to compare the in vitro and in vivo ultrasonographic appearance of the omasum and to compare omasal appearance, limits, and size in clinically healthy cows with those in cows having confirmed omasal impaction. A 3.5 MHz curvilinear transducer was used to image and record the appearance of the omasum in vitro in a water bath, and its appearance, dorsal and ventral limits, and size in 10 healthy Indian Jersey/Red Sindhi crossbred cows. The results were compared with the ultrasonographic data collected from 5 cows with omasal impaction, as confirmed at necropsy. On moving the transducer dorsoventrally in each intercostal space and below the costal arch, the wall of omasum could be seen as an echogenic arc-like structure. The difference between mean dorsoventral extents of the normal and impacted omasums was statistically insignificant. These results suggest that ultrasonographic imaging may not be useful in the diagnosis of omasal impaction in Indian crossbred cows, however, additional studies may be warranted

    Study of dimensionless quantities to analyse front and rear wall of keyhole formed during laser beam welding

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    Fluid flow mechanisms present in Keyhole (KH) during Laser Beam Welding (LBW) process influence the associated heat and mass transfer. In an attempt to describe these complexities for eventual optimization of LBW parameters, a dimensionless analysis using Mach (Ma), Raleigh (Ra), Reynolds (Re) and Marangoni (Mg) numbers have been carried out. This analysis describes hydrodynamics of melt and vapour phase appearing in the front and rear wall of KH. The non-dimensional hydrodynamic quantities describe the mechanism behind flow pattern present in melt-vapour in terms of ratio of convection–conduction heat transfer occurring within KH. The analysis shows that the higher Marangoni number indicates stronger Marangoni convection in the KH causing relatively higher capillary flow in the melt pool. The laminar-turbulent flow of melt-vapour in KH medium is described in terms of ratio of Reynolds and Mach numbers (Re/Ma). The pressure distribution in the KH accounts for the melt-vapour ejection rate. A relationship between depth and radius of KH has been obtained as a function of delivered laser power

    Dynamics of plasma expansion in the pulsed laser material interaction

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    A pulse Nd: YAG laser with pulse duration 5-10 ns, beam radius at focal point 0.2-0.4 mm, wavelengths 1064 nm, 532 nm and 238 nm with linearly polarized radiation and Gaussian beam profile, was impacted on a thin foil of titanium metal for generating plasma plume. Numerically, the above parameters were linked with average kinetic energy of the electrons and ions in the laser-induced plasma. In the present model, electrons having higher velocities are assumed to escape from plasma, that forms a negatively charged sheath around the plasma. It is seen from present computations that the forward directed nature of the laser evaporation process results from the anisotropic expansion velocities associated with different species. These velocities are mainly controlled by the initial dimension of the expanding plasma. An attempt was undertaken to estimate the length of the plume at different ambient gas pressures using an adiabatic expansion model. The rate of the plasma expansion for various Ar ion energies was derived from numerical calculations. A numerical definition of this plasma includes events like collisional/radiative, excitation/de-excitation and ionization/recombination processes involving multiples of energy levels with several ionization stages. Finally, based on a kinetic model, the plasma expansion rate across the laser beam axis was investigated

    Melt pool vorticity in deep penetration laser material welding

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    In the present study, the vorticity of melt motion in the keyhole and weld pool has been evaluated in case of high power CO2 laser beam welding. The circulation of vorticity is obtained as a function of Reynolds number for a given keyhole volume which is linked to Mach number variation. The shear stress and thermal fluxes present in the turbulent pool are linked to diffusivity and Prandtl number variation. It was shown that below a critical value of Rayleigh number, the conduction mode of melt transfer signifying beam absorption becomes dominant. Above this value, convective heat transfer indicates melting and evaporation occurring in the weld pool during laser welding. The evaporative recoil pressure expels the liquid while surface tension and hydrostatic pressure help to retain the melt in the keyhole cavity in this high power laser beam welding. The understanding of several hydrodynamic phenomena occuring in the weld pool is valuable not only for understanding basic mechanistic aspects but also for process optimization involved in laser beam welding

    Thermal dynamics-based mechanism for intense laser-induced material surface vaporization

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    Laser material processing involving welding, ablation and cutting involves interaction of intense laser pulses of nanosecond duration with a condensed phase. Such interaction involving high brightness radiative flux causes multitude of non-linear events involving thermal phase transition at soild-liquid-gas interfaces. A theoretical perspective involving thermal dynamics of the vaporization process and consequent non-linear multiple thermal phase transitions under the action of laser plasma is the subject matter of the present work. The computational calculations were carried out where titanium (Ti) was treated as a condensed medium. The solution to the partial differential equations governing the thermal dynamics and the underlying phase transition event in the multiphase system is based on non-stationary Eulerian variables. The Mach number M depicts significant fluctuations due to thermal instabilities associated with the laser beam flux and intensity. A conclusive amalgamation has been established which relates material surface temperature profile to laser intensity, laser flux and the pressure in the plasma cloud

    Diagnostic Imaging of Canine Hepatobiliary Affections: A Review

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    Hepatic disease is often treatable and has a predictable prognosis when a definitive diagnosis is made. The aim of clinicopathological evaluation of hepatobiliary affections is to identify and characterize hepatic damage and dysfunction, identify possible primary causes of secondary liver disease, differentiate causes of icterus, evaluate potential anaesthetic risks, assess prognosis and response to xenobiotics, and monitor response to therapy. This paper describes the different diagnostic methods and imaging techniques employed in diagnosis of hepatobiliary affections in dogs. Besides reviewing the significant clinical manifestations and imaging structural abnormalities in diagnostic approach to different hepatic affections, it also depicts radiographic, ultrasonographic, and wherever applicable, the laparoscopic characterization of different hepatic affections and target lesions encountered in clinical cases presented in the Teaching Veterinary Clinical Complex, COVAS, Palampur in the year 2007-2008

    Usefulness and Limitation of Ultrasonography in the Diagnosis of Intestinal Intussusception in Cows

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    The present study was conducted on 6 chronically ill Jersey/Red Sindhi cross-bred cows, which were suspected for intestinal obstruction on the basis of history and clinical signs. These cows were ultimately diagnosed with intestinal intussusception based on a combination of clinical, ultrasonographic and surgical examinations. “Bull's eye lesion” was the most prominent ultrasonographic finding, diagnostic for intussusception either trans-abdominally or transrectally. Dilated intestinal loops greater than 3.1 cm (mean ± SE, 4.41 ± 0.25) were imaged in the lower flank and the 12th intercostal space on the right side. Ultrasonography proved to be a useful tool in supplementing and substantiating the transrectal findings in cases of the bovine intestinal intussusception. However, ultrasonography was not significantly helpful where transrectal examination of the cows did not reveal any suspected intestinal mass
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