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21.
Adwait K. Pradhan Gadadhar Panda Nrusingha C. Patl Padma L. Nayak 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(2):501-512
The graft copolymerization of methyl methacrylate onto silk fibers initiated by the ferric chloride-eysteine redox system has been investigated in aqueous medium. The rate of grafting was calculated by varying the concentrations of monomer, initiator, acidity of the medium, cysteine, and temperature. The percentage of grafting increases with an increase of Fe3+ concentration up to 2,5 × 10?3 mol/L and thereafter it decreases. The graft yield increases steadily upon increasing the monomer concentration. The graft yield also increases with increasing cysteine concentration up to 0.5 × 10?3 mol/L and then decreases. The effect of the perchloric acid concentration, temperature, solvents, and certain neutral salts on graft yield has also been investigated and a suitable reaction scheme has been proposed. 相似文献
22.
A series of 4-arylidenamino-5-phenyl-4H-1,2,4-triazole-3-thiols have been synthesised and their inclusion complexes have been prepared with β-cyclodextrin. The compounds and their inclusion complexes have been characterised by studying their physical and spectral properties. The thermodynamic stability constant and free energy of activation have been determined to know the stability of inclusion complexes. Finally, the compounds and their inclusion complexes are screened for antibacterial, antioxidant and anthelmintic activities. It is found that inclusion complexes of the newly synthesised compounds have appreciable stability and inclusion complex formation increases the antibacterial, antioxidant and anthelmintic activities significantly as compared to naked compound. 相似文献
23.
D. P. Maurya M. Aqil B. P. Panda A. Ali 《Journal of Dispersion Science and Technology》2013,34(3):424-432
The main objective of the present work was to formulate and optimize a microparticulate sustained release drug delivery system of isoniazid by using a novel, alkaline extracted ispaghula husk as a polymer. Isoniazid microspheres of alkaline extracted ispaghula husk were prepared by emulsification internal ionic gelation method. Results of preliminary trials indicated that the polymer concentration, cross-linking agent and stirring speed had a noticeable effect on size and surface morphology. A four-factor three-level Box-Behnken design was employed to study the effect of independent variables on dependent variables. The particle size and entrapment efficiency varied from 30.75 to 61.78 µm and 62.27% to 85.80% respectively, depending on the polymer concentration, concentration of cross-linker and stirring speed. Optimized microspheres batch based on point prediction tool of design software exhibited 83.43% drug entrapment and 51.53 µm particle size with 97.80% and 96.37% validity, respectively at the following conditions: sodium alginate (3.55% w/v), alkaline extracted ispaghula husk (3.60% w/v), cross-linker concentration (7.82% w/v), and stirring speed (1200 rpm). The optimized formulation showed controlled drug release for more than 12 hours. The drug release followed Higuchi kinetics via a non-Fickian diffusion. 相似文献
24.
Jena Sudipta Ray Asit Sahoo Ambika Kamila Pradeep Kumar Nayak Sanghamitra Panda Pratap Chandra 《Chemistry of Natural Compounds》2021,57(6):1147-1149
Chemistry of Natural Compounds - 相似文献
25.
Ramesh Kumar Banjare Manoj Kumar Banjare Sandhyarani Panda 《Journal of solution chemistry》2020,49(1):34-51
A comprehensive study the effect of acetonitrile (ACN) with four cationic surfactants, viz. tetradecyltrimethylammonium bromide (TTAB), cetyltrimethylammonium bromide (CTAB), cetylpyridinium chloride (CPC) and cetylpyridinium bromide (CPB) was made by using the conductivity, surface tension, fluorescence and FTIR techniques. Significant micellar, interfacial and thermodynamic properties were studied by the tensiometeric and conductivity methods. The critical micelle concentration (CMC), aggregation number (Nagg), and Stern–Volmer constants (Ksv) have also been studied by the steady state fluorescence method using pyrene as probe. The fluorescence study also supports the CMC results obtained from conductivity and surface tension. FTIR was used to ascertain that the strength of intermolecular interactions such as hydrogen bonding, ion–ion pair interactions and induced dipole interactions between the surfactants and ACN depend upon the head-group of the surfactants. The interaction of surfactants with ACN is energetically favorable and occurs via direct interactions between the surfactants and ACN. The results further revealed that the strength of interactions between the surfactants and ACN follows the order: TTAB > CTAB > CPC > CPB. 相似文献
26.
Kesiya George Bishnu P Panda Manoranjan Biswal Smita Mohanty Sanjay K Nayak 《先进技术聚合物》2020,31(6):1280-1290
This work scrutinizes the utilization of ethylene propylene diene monomer rubber matrix (EPDM) with an embodiment of aramid fiber for the heat shielding applications in solid rocket motor (SRM). Aramid fibers are aromatic poly‐paraphenylene terephthalamide, here deployed are Kevlar fibers (KF). However, the literature that encompasses the thermal and mechanical behavior with the fiber loading is reported nowhere else. The effect of fiber addition on the surface morphology and density was thoroughly studied, and it revealed that the EHSMs were of lower density to act as an efficient payload for the SRM. In this regard, the thermal conductivity, heat capacity, thermal diffusivity, fire behavior, and mechanical properties of the EPDM/KF‐based EHSMs were explored. The results revealed that the EHSMs are thermally insulating and thermally stable material with balanced mechanical properties that can engender the thermal and mechanical strains of the rocket motor. Furthermore, other analytical techniques such as scanning electron microscopy and energy dispersive X‐ray spectroscopy have been exploited to monitor the performance of the char residues of the EHSM to delineate its performance in the fire atmosphere. 相似文献
27.
Joshua Lee Yuheng Bu Prasanna Sattigeri Rameswar Panda Gregory W. Wornell Leonid Karlinsky Rogerio Schmidt Feris 《Entropy (Basel, Switzerland)》2022,24(4)
As machine learning algorithms grow in popularity and diversify to many industries, ethical and legal concerns regarding their fairness have become increasingly relevant. We explore the problem of algorithmic fairness, taking an information–theoretic view. The maximal correlation framework is introduced for expressing fairness constraints and is shown to be capable of being used to derive regularizers that enforce independence and separation-based fairness criteria, which admit optimization algorithms for both discrete and continuous variables that are more computationally efficient than existing algorithms. We show that these algorithms provide smooth performance–fairness tradeoff curves and perform competitively with state-of-the-art methods on both discrete datasets (COMPAS, Adult) and continuous datasets (Communities and Crimes). 相似文献
28.
29.
Calculated 13C NMR chemical shifts were key to assigning the structures of the conformational forms of complexed and uncomplexed bispidine derivatives. 相似文献
30.
A Kerr metric describing a rotating black hole is obtained on the three brane in a five-dimensional Randall-Sundrum brane
world by considering a rotating five-dimensional black string in the bulk. We examine the causal structure of this space-time
through the geodesic equations. 相似文献