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81.
Kathryn M. L. Taylor-Pashow Thomas B. Peters Fernando F. Fondeur Aaron L. Washington II David T. Hobbs 《分离科学与技术》2015,50(18):2853-2865
The Defense Waste Processing Facility (DWPF), responsible for vitrifying high-level waste (HLW) at the Savannah River Site (SRS), is planning to introduce glycolic acid as a reductant during chemical conditioning of the waste prior to vitrification. A portion of this glycolic acid may be recycled back to the tank farm as sodium glycolate. Since glycolate can serve as a complexing agent for a variety of metallic ions, recent studies were performed to examine the effect of glycolate on the removal of Sr and actinides by monosodium titanate (MST) and modified MST (mMST) and the separation of Cs by the caustic-side solvent extraction (CSSX) process. 相似文献
82.
John M. Davis Ian A. Gravagne Robert J. Marks II 《Circuits, Systems, and Signal Processing》2010,29(6):1141-1165
The convergence of Laplace transforms on time scales is generalized to the bilateral case. The bilateral Laplace transform
of a signal on a time scale subsumes the continuous time bilateral Laplace transform, and the discrete time bilateral z-transform as special cases. As in the unilateral case, the regions of convergence (ROCs) time scale Laplace transforms are
determined by the time scale’s graininess. ROCs for the bilateral Laplace transforms of double sided time scale exponentials
are determined by two modified Hilger circles. The ROC is the intersection of points external to modified Hilger circle determined
by behavior for positive time and the points internal to the second modified Hilger circle determined by negative time. Since
graininess lies between zero and infinity, there can exist conservative ROCs applicable for all time scales. For continuous
time (ℝ) bilateral transforms, the circle radii become infinite and results in the familiar ROC between two lines parallel
to the imaginary z axis. Likewise, on ℤ, the ROC is an annulus. For signals on time scales bounded by double sided exponentials, the ROCs are
at least that of the double sided exponential. The Laplace transform is used to define the box minus shift through which time scale convolution can be defined. Generalizations of familiar properties of signals on ℝ and ℤ include
identification of the identity convolution operator, the derivative theorem, and characterizations of wide sense stationary
stochastic processes for an arbitrary time scales including autocorrelation and power spectral density expressions. 相似文献
83.
Phosphorous Levels in Peeled and Deveined Shrimp Treated with Sodium Tripolyphosphate 总被引:1,自引:0,他引:1
VICKIE TENHET GUNNAR FINNE RANZELL NICKELSON II DON TOLODAY 《Journal of food science》1981,46(2):350-352
Using volumetric and spectrophotometric methods for the determination of phosphorous, untreated shrimp were shown to have high and variable phosphorous content. When peeled and deveined shrimp were treated with 0.5% and 1.0% sodium tripolyphosphate (STP) solutions, the STP uptake was shown to be low. At these low treatment concentrations the phosphorous content in the treated shrimp did not exceed the range of natural phosphorous found in untreated shrimp. When higher treatment concentrations were used, treated thrimp could be identified. The stability of STP in treated shrimp during frozen storage was investigated using a P32 STP isotope. After 2 wk of frozen storage at –26°C only 12% of the total activity could be attributed to STP. At the same time, pyrophosphate was present at a level of 25% and orthophosphate at 27%. During further frozen storage, the STP concentration remained at approxinately 12%, pyrophosphate dropped down to as low as 2% while orthophosphate gradually increased reaching 45% of total activity at the end of 10 wk storage period. 相似文献
84.
Alvin C. Bach II David W. Cochran 《Journal of The Association for Laboratory Automation》2002,7(6):103-107
We have designed and implemented an automated walkup NMR computer application for use by synthetic chemists. The Wyeth Walkup NMR (WWNMR) application is a TCL/TK graphical user interface front-end to Varian's NMR automation routines. The key feature of WWNMR is that the chemists are isolated from the spectrometer's control program (VNMR) and only enter information to WWNMR windows for a sample to be run. The resulting data can be printed out on paper, or stored on disk for easy access by all users at their desktops. Proton and carbon NMR experiments are available. An overview of the WWNMR application will be presented. 相似文献
85.
Satyendra K. Tripathi Khushboo Kesharwani Grace Kaul Abdul Akhir Deepanshi Saxena Dr. Ramesh Singh Dr. Narendra K. Mishra Prof. Archna Pandey Dr. Sidharth Chopra Dr. Khashti B. Joshi 《ChemMedChem》2022,17(15):e202200251
An amyloid-β inspired biocompatible short peptide amphiphile (sPA) molecule was used for controlled and targeted delivery of bioactive silver nanoparticles via transforming sPA nanostructures. Such sPA-AgNPs hybrid structures can be further used to develop antibacterial materials to combat emerging bacterial resistance. Due to the excellent antibacterial activity of silver, the growth of clinically relevant bacteria was inhibited in the presence of AgNPs-sPA hybrids. Bacterial tests demonstrated that the high biocompatibility and low cytotoxicity of the designed sPA allow it to work as a model drug delivery agent. It therefore shows great potential in locally addressing bacterial infections. The results of our study suggest that these nanodevices have the potential to trap and then engage in the facile delivery of their chemical payload at the target site, thereby working as potential delivery materials. This system has potential therapeutic value for the treatment of microbiota triggered progression of neurodegenerative diseases. 相似文献
86.
Kavalloor Murali Lakshmi Jose V. Rival Pakath Sreeraj Sindhu R. Nambiar Chinnaiah Jeyabharathi Nonappa Edakkattuparambil Sidharth Shibu 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(15):2207119
Atomically precise nanoclusters (NCs) have recently emerged as ideal building blocks for constructing self-assembled multifunctional superstructures. The existing structures are based on various non-covalent interactions of the ligands on the NC surface, resulting in inter-NC interactions. Despite recent demonstrations on light-induced reversible self-assembly, long-range reversible self-assembly based on dynamic covalent chemistry on the NC surface has yet to be investigated. Here, it is shown that Au25 NCs containing thiolated umbelliferone (7-hydroxycoumarin) ligands allow [2+2] photocycloaddition reaction-induced self-assembly into colloidal-level toroids. The toroids upon further irradiation undergo inter-toroidal reaction resulting in macroscopic supertoroidal honey-comb frameworks. Systematic investigation using electron microscopy, atomic force microscopy (AFM), and electron tomography (ET) suggest that the NCs initially form spherical aggregates. The spherical structures further undergo fusion resulting in toroid formation. Finally, the toroids fuse into macroscopic honeycomb frameworks. As a proof-of-concept, a cross-photocycloaddition reaction between coumarin-tethered NCs and an anticancer drug (5-fluorouracil) is demonstrated as a model photo-controlled drug release system. The model system allows systematic loading and unloading of the drug during the assembly and disassembly under two different wavelengths. The results suggest that the dynamic covalent chemistry on the NC surface offers a facile route for hierarchical multifunctional frameworks and photocontrolled drug release. 相似文献
87.
Sidharth Kumar Sethi Rupesh Raina Shyam Bihari Bansal Anvitha Soundararajan Maninder Dhaliwal Veena Raghunathan Meenal Kalra Kritika Soni Samit Kumar Mahato Ananya Vadhera Dinesh Kumar Yadav Timothy Bunchman 《Hemodialysis international. International Symposium on Home Hemodialysis》2023,27(3):308-317
88.
89.
The failure characteristic of graphite polyetheretherketone (Gr/PEEK) under compression with a centrally located circular discontinuity was investigated through experimentation and a nonlinear ply-by-ply finite element technique. The stacking sequence of the laminates investigated were: [0 °16], [90 °16], [±45 °]4S [0 °/90 °]4S, and [0 °/ ± 45 0°/90 °]2S. In the experimentation, [90 °]16, [0 °/90 °]4S, and [0 °/ ±45 °/90 °]2S laminates, as well as three of the [0 °]16, failed due to a crack that was normal to the loading direction and initiated from the edge of the hole progressing to the outer edges of the specimen. The [±45 °]4S specimens failed to support the load due to an internal crack that originated from the hole's edge and then traveled at an angle of about 42% to the direction of loading. The finite element method used to analytically model the failure of Gr/PEEK accurately modeled the response of the specimens tested experimentally. 相似文献
90.
Hawkins R.T. II Jones M.D. Pepper S.H. Goll J.H. Ravel M.K. 《IEEE transactions on instrumentation and measurement》1992,41(4):467-475
Deconvolution of measurement system effects from pulse response measurements is demonstrated to yield reproducible, accurate characterization of the impulse response (and vector frequency response) of a photodetector or photoreceiver, as well as the intensity waveform of an optical pulse. Calibration is based on a <3-ps FWHM (full width at half maximum) optical pulse and a 50-GHz 3-dB bandwidth electrical sampling system. Vector characterization of a photodetector/photoreceiver to >40 GHz and an optical pulse source to >30 GHz are demonstrated. Calibration and effects of noise are discussed 相似文献