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排序方式: 共有193条查询结果,搜索用时 15 毫秒
11.
Aradhya Dev Srivastav Vireshwar Singh Deepak Singh Sunita Singh Suresh Kumar Patel Dilip Kumar Sudeep Yadav Balendu Shekher Giri Dhananjay Singh 《印度化学会志》2022,99(8):100632
Nelumbo nucifera leaves are rich source of natural wax possessing super-hydrophobic properties. It provides protection to them from ecological turbulences and climatic wear and tear. In this study, various experiments have been conducted to observe the yield of extraction and the determination of various functional groups, which are present in natural wax, derived from Nelumbo nucifera leaves. The natural wax has been extracted from lotus leaves through non-polar (hexane) and polar (ethanol) solvent via different extraction methods. The superhydrophobic wax has been successfully extracted with hexane. Whereas, ethanol did not extract the water-repellent wax of lotus leaf. Considering the cumulative amount, i.e. (desired + undesired), the maceration shows the extraction of 2.9% (%w/w, through hexane) and 10.2% (%w/w, through ethanol), while it was found 2.5% (%w/w, cycle period 15 min) and 9.0% (%w/w, cycle period 26 min) respectively, in case of Soxhlet extraction technique. For this specific case of natural wax recovery from biomass (lotus leaf), the maceration (traditional method) resulted a little bit superior extraction yield in comparison to the Soxhlet extraction method for extraction of crude wax. In the case of non-polar solvent (hexane), an extraction yield of 1.97% (%w/w) through maceration method was observed while in the case of non-polar solvent (ethanol), an extraction yield of 1.62% (%w/w) through Soxhlet extraction was observed. The TLC analysis on both types of extracts was performed. For the detection of various hydrocarbon chains in the crude wax extracts, FTIR was also performed. Topography of wax surface and wax-coated waterproof fabric was compared through SEM. 相似文献
12.
Darolia Poonam Jangra Malik Sunita Sharma Dimple Kumar Manish Garg Sapana Sharma V. K. 《Journal of solution chemistry》2021,50(11-12):1391-1431
Journal of Solution Chemistry - Excess molar volumes, $$V_{{}}^{{\text{E}}}$$ , excess isentropic compressibilities, $$\kappa_{{\text{S}}}^{{\text{E}}}$$ of binary 1-butyl-2,3-dimethylimidazolium... 相似文献
13.
Shailajan Sunita Hande Harshada Joshi Harshvardhan Tiwari Bhavesh Menon Sasikumar 《平面色谱法杂志一现代薄层色谱法》2014,27(1):23-28
JPC – Journal of Planar Chromatography – Modern TLC - Marmelosin is one of the major phytochemical constituents of Aegle marmelos (L.) Corr. (Rutaceae). Till date, there are no methods... 相似文献
14.
K. Kasi Amarnath Reddy Smriti Moi Ashwini Dolle Basavaprabhu Hosamani Kiran Krishnamurthy Sunita Prakash Srinivasarao Raghothama Konkallu Hanumae Gowd 《Helvetica chimica acta》2020,103(7):e2000062
Dimedone is the most widely used chemical probe for detection of cysteine sulfenic acid in peptides and proteins. The reaction of dimedone with cysteine sulfenic acid results in the formation of unique cysteine dimedone motif containing thioether bridge. Based on the structure of cysteine dimedone residue in polypeptide, a new building block of Fmoc-Cys(Dmd)-OH was developed for solid phase synthesis of peptide cysteine dimedone. Mass spectrometric sequencing of synthetic peptides have confirmed successful incorporation of cysteine dimedone in peptide chain using HBTU/HOBt as a coupling agent. The new method permits synthesis of peptides containing both cysteine thiol and cysteine dimedone in the same sequence which was difficult to achieve by conventional methods. The synthetic peptide of glutathione cysteine dimedone was used as a standard in probing the air-mediated oxidation of thiol to disulfide form of glutathione. The co-elution of standard peptide and reaction mixture of oxidation of glutathione in presence of dimedone using RP-HPLC have confirmed the formation of glutathione cysteine sulfenic as an intermediate in the air-mediated oxidation of glutathione. The synthetic peptides of cysteine dimedone may find application in the field of redox proteomics and generation of antibodies against modified cysteine residue. 相似文献
15.
Khongsit Ansar Rajput Yudhishthir Singh Meena Sunita Sharma Rajan 《Journal of Analytical Chemistry》2022,77(3):295-300
Journal of Analytical Chemistry - Methods for the determination of mercury are described using gold nanoparticles functionalized with nitrogen containing cyclic molecules. Detection methods are... 相似文献
16.
The thermal lensing effect of the Copper Vapor Laser (CVL) was studied by considering both its windows and the active medium. The equivalent combined focal length of the active medium and windows was measured to be 52 mts under operating conditions for a 35W CVL. The variation of focal length with the operating parameters was studied. 相似文献
17.
Sunita Hooda 《Journal of Molecular Structure》2010,963(1):27-738
Terpolymers of methyl acrylate/vinyl acetate/N-vinyl carbazole (M/A/C) with different compositions were synthesized by solution polymerization using AIBN as an initiator. Composition of terpolymers was determined from quantitative 13C{1H} NMR spectrum. Two-dimensional heteronuclear single quantum correlation (HSQC) and total correlated spectroscopy (TOCSY) were used to assign the methylene and methine carbon resonances by analyzing two and three bond order couplings. Various resonance signals were assigned to different compositional and configurational sequences with the help of one- and two-dimensional NMR spectra. Three and four bond order coupling between carbonyl carbon and other neighboring protons have been investigated with the help of 2D heteronuclear multiple bond correlation (HMBC) spectra. The complex and overlapped 1H NMR spectrum of terpolymer was analyzed completely with the help of 2D HSQC and TOCSY spectra. 相似文献
18.
This paper presents the modeling and characterization of an optical fiber grating for maximum reflectivity. Grating length and change in refractive index are the critical parameters in contributing to the performance of fiber Bragg grating. The wavelength chosen for analysis is from the third window to minimize the attenuation. The reflection spectra, bandwidth and side lobes strength were analyzed with different lengths and change in refractive index. The simulations are based on solving coupled mode equations by transfer matrix method that describes the interaction of guided modes. 相似文献
19.
Gold,silver, and palladium nanoparticle/nano-agglomerate generation,collection, and characterization
Sunita R. Boddu Veera R. Gutti Tushar K. Ghosh Robert V. Tompson Sudarshan K. Loyalka 《Journal of nanoparticle research》2011,13(12):6591-6601
Generation, collection, and characterization of gold, silver, and palladium nanoparticles and nano-agglomerates (collectively
“nanoparticles”) have been explored. The nanoparticles were generated with a spark aerosol generator (Palas GFG-1000). They
were collected using a deposition cell under diffusion and thermophoresis. The shapes and sizes of the deposited particles
were measured using transmission electron microscopy (TEM). TEM images showed that the particles were in the range of 8–100 nm
in diameter, and their shapes varied from nearly spherical to highly non-spherical. Thermophoresis enhanced the deposition
of nanoparticles (over the diffusive or the isothermal deposition) in all cases. Further, the size distributions of the nanoparticles
generated in the gas phase (aerosol) were measured using a scanning mobility particle sizer (SMPS 3080, TSI) spectrometer.
The SMPS results show that an increase in the spark frequency of the generator shifted the size distributions of the nanoparticles
to larger diameters, and the total particle mass production rate increased linearly with increase in the spark frequency.
The computational fluid dynamics code Fluent (Ansys) was used to model the flow in the deposition cell, and the computed results
conform to the observations. 相似文献
20.
This study reports the use of quartz crystal nanobalance (QCN) to study the adsorption of two model molecules namely albumin and doxycycline by hydroxyapatite (HA). The work focuses on the deposition of a stable coating of HA on the quartz crystal, modification of the coating using doxycycline and its subsequent effects on albumin adsorption. The uniformity and thickness of the HA coating has been studied using atomic force microscopy (AFM). The functional groups to ascertain the presence of the selected moieties have been characterized by Raman spectroscopy. The results indicate that the mass of albumin deposited on the surface of the HA coated quartz crystal functionalized with doxycycline shows a substantial increase when compared to the standard HA coated quartz crystal. The adsorbed albumin has also been found to be retained for an enhanced period of time. This surface immobilization of doxycycline and subsequent albumin adsorption seem to be a promising approach to confer biomaterials with antithrombogenic and antibacterial surfaces. 相似文献