Phenol-formaldehyde resin is an inevitable polymer material because of their excellent properties like heat resistance, chemical resistance, creep resistance, and low water sorption. But the drawback associated with PF matrix is buckling and brittleness. The incorporation of nanofillers can effectively reduce these problems. Carbon nanotubes is one among the nanofiller which is widely used to enhance the mechanical, thermal, electrical properties of the host matrix.The present study deals with the synthesis and comparison of two Phenol-formaldehyde nanocomposites incorporated with pristine multiwalled carbon nanotubes and carboxylated multiwalled carbon nanotubes via in-situ polymerisation technique. The effect of filler loading (MWCNT, MWCNT-COOH) with different weight percentages (0.05 wt%, 0.08 wt%, 0.12 wt%, 0.15 wt%) has been investigated in this study. Pristine MWCNT was functionalised with carboxyl groups and confirmed by XRD, FT-IR, CHN analysis, X-ray photoelectron spectroscopy, AFM and Raman spectra. All these analysis showed successful funtionalisation of pure MWCNT. The prepared nanocomposites were compared by mechanical, thermal and morphological analysis. The effect of both fillers on tensile strength, stress-strain, young’s modulus and elongation at break were also analysed. The addition of MWCNT and MWCNT-COOH have enhanced the mechanical and thermal properties of the prepared nanocomposite. The mechanical properties of PF-MWCNT nanocomposite showed a maxima for 0.12 wt% and for PF-MWCNTCOOH nanocomposite it was 0.08 wt%. Higher thermal stability was exhibited for 0.15 wt% MWCNT loading. The thermal stability enhanced by the addition of MWCNT COOH upto 0.12 wt% and then declined. Moreover the prepared nanocomposites were morphologically characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM) and from the fracture analysis it is clear that the reinforcements brought plastic deformation of phenol-formaldehyde nanocomposite from brittle to more ductile material. From the TEM image it was clear that the presence of carboxyl groups attached on MWCNT reduced agglomeration in PF matrix. Halpin-Tsai modelling was done for comparing experimental and theoretical values of tensile modulus and it illustrates good correlation.
Extra-nasopharyngeal lymphoepithelioma-like carcinomas (LELC) are uncommon epithelial tumors. A few isolated case reports and series are available in literature involving the larynx, pharynx, salivary gland, lung etc., but involvement in the parapharyngeal space has not yet been reported. We aim to highlight one such case that has a clinical and radiological characteristic of a benign lesion whilst the histopathology reveals an infiltrating neoplasm. The typical clinical aggressiveness of a classical LELC of extra-nasopharyngeal lesion as described in literature is not present in our case. Also seen is an uncommon finding of abnormal branching of left external carotid artery. There is no standard treatment protocol for such a tumor; however, wide excision of this tumor in the parapharyngeal space via trans-cervical, trans-mandibular, trans-palatal approach has shown good and satisfactory tumor control of the primary site so far.
Agada Tantra is one among the eight branches of Ayurveda. Apart from samhitas (classical texts), there are many text books dealing with agada tantra (toxicology) written in various regional Indian languages. Some of them have been translated to English, but many are yet to see light. Kerala which is rich in its Ayurveda legacy has made much contribution to the subject. Vishavaidya Jyotsnika is one such textbook which gives immense knowledge about the practice of vishachikitsa. Dhootha lakshanas in cases of visha (poison) and the concept of amritakala and vishakala has been explained only in this book. Pashu chikitsa in cases of poisoning has also been explained here. This text contributes largely to the practice as well research in agada tantra. This article is based on the text Vishavaidya Jyotsnika an English Translation published by Department of Agada Tantra, Vaidyaratnam P.S Varier Ayurveda College, Kottakkal, Kerala.
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