Three-Dimensional Security Barrier Impact Response Modeling

The occurrence of terrorist vehicular bomb attacks has been frequently reported. Perimeter security barriers are designed and guilt to defeat vehicle penetration. Due to the complexity of designing a security barrier, the current practice is to physically crash test the barrier head-on with a threat vehicle, at a certain velocity as a validation of the design. As full-scale vehicular crash tests are costly, facility designers are often forced to use existing barriers without the benefit of designing new, innovative and cost-effective systems for a specific threat. With the present-day computing capability, conducting three-dimensional simulations of vehicular crash dynamics on a personal computer has become very feasible. Vehicular crash simulations are traditionally conducted using finite element (FE) programs, which require extensive computer runtime. A first-principle approach based on the physics of crash dynamics has been developed to reduce computer runtime. Nonlinear structural responses due to the inelastic material effect and large deformation during the vehicular impact are taken into account. An explicit, step-by-step solution scheme is used for solving the transient dynamic problem. No inversions of large matrices are necessary at each time step in this algorithm. Validation examples using crash test data and data from the literature are presented to demonstrate the accuracy and efficiency of the developed algorithm

Fokker-Planck Kinetic description of small-scale fluid turbulence for classical incompressible fluids

Extending the statistical approach proposed in a parallel paper \cite% {Tessarotto2008-aa}, purpose of this work is to propose a stochastic inverse kinetic theory for small-scale hydrodynamic turbulence based on the introduction of a suitable \textit{local phase-space probability density function} (pdf). In particular, we pose the problem of the construction of Fokker-Planck kinetic models of hydrodynamic turbulence. The approach here adopted is based on the so-called IKT approach (inverse kinetic theory), developed by Ellero et al. (2004-2008) which permits an exact phase-space description of incompressible fluids based on the adoption of a local pdf. We intend to show that for prescribed models of stochasticity the present approach permits to determine uniquely the time evolution of the stochastic fluid fields. The stochastic-averaged local pdf is shown to obey a kinetic equation which, although generally non-Markovian, locally in velocity-space can be approximated by means of a suitable Fokker-planck kinetic equation. As a side result, the same pdf is proven to have generally a non-Gaussian behavior.Comment: Contributed paper at RGD26 (Kyoto, Japan, July 2008

Seroprevalence of canine dirofilariosis, granulocytic anaplasmosis and lyme borreliosis of public health importance in dogs from India’s North East

Aim: Vector-borne infections namely dirofilariosis, ehrlichiosis, anaplasmosis and lyme borreliosis are being recognized as emerging and/or re-emerging problems in dogs and man due to rapid extension of zoogeographical ranges of many causative agents through international tourism and increase mobility of dogs at national and international level towards meeting the demand for companion animals in the present day society. Anticipating such situation, a serological study was conducted in dogs from North East India to estimate the prevalence of zoonotically important Dirofilaria immitis, Anaplasma phagocytophilum and Borrelia burgdorferi along with Ehrlichia canis. Materials and Methods: Serological study was carried out using enzyme immunoassay in commercial SNAP 4DX® test kit (Idexx Laboratories, USA). The study was conducted in 191 dogs comprising 82 pets, 57 stray and 52 working dogs owned by defence organizations. Results: The study revealed seroprevalence of mosquito-borne D. immitis (17.80%), tick-borne E. canis (22.51%) and A. phagocytophilum (4.71%) with an overall 41.88% prevalence of pathogens in single or co-infection. Serological evidence of tick-borne lyme borreliosis due to B. burgdorferi could not be established in dogs in the present study. Of the zoonotic species, highest prevalence of D. immitis was found in the stray dogs (22.80%) and that of A. phagocytophilum in pet dogs (6.09%). Conclusion: The results of the present serological study serve as baseline information on the prevalence of A. phagocytophilum in dogs reported for the first time in India and reaffirmation on the high prevalence of D. immitis and E. canis in the North East India

Non-linear charge reduction effect in strongly-coupled plasmas

The charge reduction effect, produced by the nonlinear Debye screening of high-Z charges occuring in strongly-coupled plasmas, is investigated. An analytic asymptotic expression is obtained for the charge reduction factor which determines the Debye-Hueckel potential generated by a charged test particle. Its relevant parametric dependencies are analyzed and shown to predict a strong charge reduction effect in strongly-coupled plasmas.Comment: 4 figure

Transformer Oil Quality Diagnostic Using Spectroscopy Techniques - a Review

Transformer serves as a vital component in the electrical energy supply system. In order to have an uninterrupted power supply, it is essential to timely monitor the condition of the transformer. A transformer has many components, out of which the transformer oil is one of the most crucial. It provides insulation and keeps the transformer cool. With ageing, the quality of the transformer oil degrades, and it loses its insulation properties that become a threat to the supply system. Optical Spectroscopy has gained a lot of attention in monitoring the quality of transformer oil in the past few years for various advantages. This paper reviews some of the commonly applied Spectroscopy techniques to monitor the various components of transformer oil by which we can predict the quality of the oil