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  • Author: R.K. Bhatt x
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Abstract

Failure of a high pressure (HP) turbine blade in a military turbofan engine is investigated to determine the root cause of failure. Forensic and metallurgical investigations are carried out on the affected blades. The loss of coating and the presence of heavily oxidized intergranular fracture features including substrate material aging and airfoil curling in the trailing edge of a representative blade indicate that the coating is not providing adequate oxidation protection and the blade material substrate is not suitable for the application at hand. Coating spallation followed by substrate oxidation and aging leading to intergranular cracking and localized trailing edge curling is the root cause of the blade failure. The remaining portion of the blade fracture surface showed ductile overload features in the final failure. The damage observed in downstream components is due to secondary effects.

Abstract

Among Human immunodeficiency virus (HIV) infected individuals, around two-thirds of patients present with neuroAIDS, where HIV-associated neurocognitive disorders (HAND), and HIV-associated dementia (HAD) are the most prevailing neurological complications. The neuropathology of neuroAIDS can be characterized by the presence of HIV infected macrophages and microglia in the brain, with the formation of multinucleated giant cells. Global predominant subtypes of HIV-1 clade B and C infections influence the differential effect of immune and neuronal dysfunctions, leading to clade-specific clinical variation in neuroAIDS patient cohorts. Highly active antiretroviral therapy (HAART) enhances the survival rate among AIDS patients, but due to the inability to cross the Blood-Brain-Barrier (BBB), incidence of neuroAIDS during disease progression may be envisaged. The complex structure of blood-brain-barrier, and poor pharmacokinetic profile coupled with weak bio-distribution of antiretroviral drugs, are the principle barriers for the treatment of neuroAIDS. In the combined antiretroviral therapy (cART) era, the frequency of HAD has decreased; however the incidence of asymptomatic neurocognitive impairment (ANI) and minor neurocognitive disorder (MND) remains consistent. Therefore, several effective novel nanotechnology based therapeutic approaches have been developed to improve the availability of antiretroviral drugs in the brain for the management of neuroAIDS.

Summary

Despite its high prevalence and pathogenicity, Stilesia globipunctata is a neglected cestode infection of ruminants in the tropics and sub-tropics. The present study reports the effect of sex, age, year and month on the prevalence of S. globipunctata in the goat. A total of 5208 eviscerated intestines of the goat carcasses were screened for a period of seven years, from January 2001 to December 2007. The overall prevalence of 36.6 % was significantly affected by the factors studied (P<0.05). Male goats were more susceptible to the S. globipunctata infection than that of female (P<0.05). Goat aged between 6 months and 1 year were found to be significantly more susceptible (P<0.05) which was followed by animals between 1 and 4 years of age and then more than 4 years of age. Morbidity was high (59 to 86 %) in animals of less than one year of age. The striking observation was that the prevalence peaked during monsoon and at nadir in May.