This paper investigates the repair of polymer matrix composites and validates the repair by static testing. Scarf repair is carried out on the laminates and cured under vacuum. It is observed that 80% of tensile strength is recovered due to this process. Therefore, this investigation highlights the significance of atmospheric pressure plasma treatment on repair of graphite epoxy laminate. It is observed that the surface energy of graphite epoxy laminate has improved significantly due to atmospheric pressure plasma treatment. Atmospheric pressure plasma treatment results in noteworthy increase in oxygen functionalities as detected by X-ray photoelectron spectroscopy, as well as surface roughness as detected by atomic force microscopy. The improvement in adhesion properties is correlated with lap shear strength of adhesive bonded joints and mode of failure has been analyzed by scanning electron microscopy. The plasma-treated laminates, when used for repair, provided an additional 12% in the tensile strength and thereby retaining a strength increase up to 92%.

COVID 19 (SARS-CoV-2) has emerged as one of the worst pandemics that have tormented the globe due to its highly contagious nature. Even if the disease manifests fever-like symptoms mostly, the disease may progress to the pulmonary-hyper inflammatory phase, with severe pneumonia, hypoxia and subsequent multiple organ infection. This subsequently creates a huge burden to the health care systems across the globe for an immediate arrangement of ventilator facilities, oxygen supply and advanced health care. We evaluated the pathological similarity of COVID-19 with other airway obstructive disorders such as COPD and asthma and found typical mucus hypersecretion and mucus plugging in COVID-19 subjects. From several bronchoscopy and clinical autopsy carried out in COVID 19 patients, the overexpression of mucin gene was evident which play a significant role in mucus hypersecretion and accumulation, leading to airway obstruction and further to respiratory distress. In the present work, we highlight the need for intense research inputs to elucidate the exact role the mucus plays in worsening COVID-19 symptoms. This will further help to find a proper approach to quantify the airway mucus plugging in each patient and to develop an appropriate therapy either to inhibit mucus secretion or to improve mucus clearance through well-designed clinical trials.

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