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2.
Sci Rep ; 13(1): 16087, 2023 Sep 26.
Article in English | MEDLINE | ID: mdl-37752170

ABSTRACT

We present experimental results of the trace argon impurity puffing in the ohmic plasmas of Aditya-U tokamak performed to study the argon transport behaviour. Argon line emissions in visible and Vacuum Ultra Violet (VUV) spectral ranges arising from the plasma edge and core respectively are measured simultaneously. During the experiments, space resolved brightness profile of Ar1+ line emissions at 472.69 nm (3p44s 2P3/2-3p44p 2D3/2), 473.59 nm (3p44s 4P5/2-3p44p 4P3/2), 476.49 nm (3p44s 2P1/2-3p44p 2P3/2), 480.60 nm (3p44s 4P5/2-3p44p 4P5/2) are recorded using a high resolution visible spectrometer. Also, a VUV spectrometer has been used to simultaneously observe Ar13+ line emission at 18.79 nm (2s22p 2P3/2-2s2p2 2P3/2) and Ar14+ line emission at 22.11 nm (2s2 1S0-2s2p 1P1). The diffusivity and convective velocity of Ar are obtained by comparing the measured radial emissivity profile of Ar1+ emission and the line intensity ratio of Ar13+ and Ar14+ ions, with those simulated using the impurity transport code, STRAHL. Argon diffusivities ~ 12 m2/s and ~ 0.3 m2/s have been observed in the edge (ρ > 0.85) and core region of the Aditya-U, respectively. The diffusivity values both in the edge and core region are found to be higher than the neo-classical values suggesting that the argon impurity transport is mainly anomalous in the Aditya-U tokamak. Also, an inward pinch of ~ 10 m/s mainly driven by Ware pinch is required to match the measured and simulated data. The measured peaked profile of Ar density suggests impurity accumulation in these discharges.

3.
Mar Pollut Bull ; 186: 114488, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36563603

ABSTRACT

In this novel study, an attempt has been made to prepare porous crosslinked poly(ethylene-co-vinyl acetate) polymer (C-EVA). The porous C-EVA was prepared by grafting of maleic anhydride and cetyl alcohol onto the polymer backbone with addition of NaCl as porogen in the brabender mixture at 120 °C and 80 rpm. This was followed by leaching of NaCl with water extraction to generate a highly porous polymer structure which was evident from its SEM micrographs. The polymer was found to have excellent swelling capacity in various oils and organic solvents and showed good selective absorption capacity. The reusability of the synthesized polymer was studied and it was found that it could be reused for more than 30 absorption desorption cycles without undergoing much change in its absorption capacity. The cross-linked polymeric composite was further characterized by FTIR, TGA, XRD, and SEM.


Subject(s)
Sodium Chloride , Wastewater , Porosity , Solvents/chemistry , Oils/chemistry , Polymers
4.
AJNR Am J Neuroradiol ; 40(8): 1291-1298, 2019 08.
Article in English | MEDLINE | ID: mdl-31345946

ABSTRACT

BACKGROUND AND PURPOSE: White matter lesions are 1 age-related manifestation of cerebrovascular disease, but subthreshold abnormalities have been identified in nonlesional WM. We hypothesized that structural and physiologic MR imaging findings of early cerebrovascular disease can be measured in middle-aged subjects in tissue adjacent to WM lesions, termed "penumbra." MATERIALS AND METHODS: WM lesions were defined using automated segmentation in 463 subjects, 43-56 years of age, from the Coronary Artery Risk Development in Young Adults (CARDIA) longitudinal observational cohort study. We described 0- to 2-mm and 2- to 4-mm-thick spatially defined penumbral WM tissue ROIs as rings surrounding WM lesions. The remaining WM was defined as distant normal-appearing WM. Mean signal intensities were measured for FLAIR, T1-, and T2-weighted images, and from fractional anisotropy, mean diffusivity, CBF, and vascular reactivity maps. Group comparisons were made using Kruskal-Wallis and pair-wise t tests. RESULTS: Lesion volumes averaged 0.738 ± 0.842 cm3 (range, 0.005-7.27 cm3). Mean signal intensity for FLAIR, T2, and mean diffusivity was increased, while T1, fractional anisotropy, and CBF were decreased in white matter lesions versus distant normal-appearing WM, with penumbral tissues showing graded intermediate values (corrected P < .001 for all group/parameter comparisons). Vascular reactivity was significantly elevated in white matter lesions and penumbral tissue compared with distant normal-appearing white matter (corrected P ≤ .001). CONCLUSIONS: Even in relatively healthy 43- to 56-year-old subjects with small white matter lesion burden, structural and functional MR imaging in penumbral tissue reveals significant signal abnormalities versus white matter lesions and other normal WM. Findings suggest that the onset of WM injury starts by middle age and involves substantially more tissue than evident from focal white matter lesions visualized on structural imaging.


Subject(s)
Brain/pathology , Cerebrovascular Disorders/pathology , Diffusion Magnetic Resonance Imaging/methods , Neuroimaging/methods , White Matter/pathology , Adult , Brain/diagnostic imaging , Cerebrovascular Disorders/diagnostic imaging , Cohort Studies , Female , Humans , Longitudinal Studies , Male , Middle Aged , White Matter/diagnostic imaging
5.
Biotechnol Lett ; 35(4): 607-11, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23264266

ABSTRACT

Using a new isolate of Pseudomonas aeruginosa, we obtained 7 g cell dry wt (CDW/l) using 5 % (w/v) glucose. Crude polyhydroxyalkanoates were obtained at 14.6 % of CDW. FTIR and NMR analysis confirmed that this was a new co-polymer: 3-hydroxyvalerate-co-5-hydroxydecenoate. Differential scanning calorimetry analysis showed two different melting temperatures of the copolymer and also indicated the glass transition temperature to be 4 °C. The polydispersity index of the polymer was 1.059.


Subject(s)
Biopolymers/chemistry , Biopolymers/metabolism , Decanoic Acids/analysis , Hydroxy Acids/analysis , Polyesters/analysis , Pseudomonas aeruginosa/metabolism , Valerates/analysis , Calorimetry , Glucose/metabolism , Magnetic Resonance Spectroscopy , Pseudomonas aeruginosa/isolation & purification , Spectroscopy, Fourier Transform Infrared , Transition Temperature
6.
Nepal J Ophthalmol ; 3(2): 191-2, 2011.
Article in English | MEDLINE | ID: mdl-21876596

ABSTRACT

BACKGROUND: ITP can give rise to bleeding episodes in different parts of the body including the central nervous system with various systemic manifestations. CASE: An eight-year old female child, diagnosed as a case of chronic ITP for last two years, developed intense headache and vomiting for a few days before admission. This was associated with right sided mid dilated pupil with brisk reaction to light. MRI-angiography showed a bleeding aneurysm of posterior communicating artery. The features of raised intra cranial tension subsided with conservative management but the anisocoria persisted. CONCLUSION: A bleeding aneurysm can manifest with anisocoria as a sign of partial third cranial nerve palsy.


Subject(s)
Anisocoria/etiology , Cerebral Hemorrhage/etiology , Intracranial Aneurysm/complications , Oculomotor Nerve Diseases/etiology , Purpura, Thrombocytopenic, Idiopathic/complications , Anisocoria/diagnosis , Cerebral Hemorrhage/diagnosis , Child , Female , Humans , Intracranial Aneurysm/diagnosis , Oculomotor Nerve Diseases/diagnosis
8.
Bioresour Technol ; 97(13): 1529-35, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16099647

ABSTRACT

Methyl methacrylate (MMA) was graft copolymerized onto Bombyx mori fibre (natural silk). The graft copolymerization was carried out by photopolymerization of MMA using semiconductor particles (CdS) as photocatalyst in the presence of visible light. The effect of additives like triethylamine (Et(3)N) and ethylene glycol on graft copolymerization was studied. We have achieved 2-10% graft conversion with 10-20% homopolymer formation. After removal of the homopolymer, the graft copolymer (grafted fibre) was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC). The chemical resistance of grafted fibre was compared with virgin one.


Subject(s)
Bombyx/chemistry , Cadmium Compounds/chemistry , Methylmethacrylate/chemistry , Photochemistry/methods , Silk/chemistry , Silk/ultrastructure , Sulfides/chemistry , Textiles/analysis , Animals , Cadmium Compounds/radiation effects , Catalysis , Dose-Response Relationship, Radiation , Light , Materials Testing , Methylmethacrylate/radiation effects , Particle Size , Polymers/chemistry , Polymers/radiation effects , Radiation Dosage , Semiconductors , Sulfides/radiation effects , Surface Properties
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