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11.
M. M. Charyulu V. Ramachandhran Rajendra Swarup V. V. Ramakrishna M. S. Hanra V. Venugopal B. M. Mishra 《Journal of Radioanalytical and Nuclear Chemistry》2000,243(3):697-700
Donnan dialysis and diffusion dialysis techniques are investigated for deacidification and possible concentration of actinide bearing acidic streams. Cation and anion exchange membranes are used in a two compartment dialysis cell to selectively remove acid from americium solutions. Acid concentrations, as high as 8.0M HNO3 are used and the stability of membranes are ascertained. Possibility of simultaneous deacidification and concentration of acidic americium solutions are indicated by combining simple osmosis with diffusion dialysis. All the experiments are carried out under non stirring conditions at room temperature. 相似文献
12.
Kamakshaiah S. Rau R. S. N. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1977,5(1):1-6
Arc voltage - current characteristics and threshold current densities occuring during the formation of anode spots in triggered vacuum gaps are reported. Single pulses of 1.65 ms arcing time, which correspond to switching surge currents, are used in the study with copper and aluminum anodes. The threshold values are 1.75 times the values reported earlier using the longer, 8 mis, arcing time. They are found to depend upon the duration of arcing time as well as upon electrode material, surface conditions, electrode size and contact separation. Lateral inhomogenity in the electrode geometry appears to reduce the threshold value by promoting early formation of anode spots. 相似文献
13.
I. C. Pius M. M. Charyulu C. K. Sivaramakrishnan S. K. Patil 《Journal of Radioanalytical and Nuclear Chemistry》1994,186(5):385-392
The extraction of Pu(IV) from oxalic acid-nitric acid mixtures has been investigated using a liquid anion exchanger, Aliquat-336, in xylene. The presence of oxalic acid is known to have adverse effects on the extraction of Pu(IV) by Aliquat-336. The use of cations, Al(III), Fe(III) or Zr(IV) was explored to overcome the effect of oxalic acid on Pu(IV) extraction. The data obtained reveal that Pu(IV) is quantitatively extracted by Aliquat-336, even in the presence of oxalic acid, when Al(III), Fe(III) or Zr(IV) is added. The extracted Pu(IV) can be back-extracted using aqueous ammonium carbonate. 相似文献
14.
G. V. Rathaiah J. Krishnama Charyulu M. C. Eshwar 《Journal of Radioanalytical and Nuclear Chemistry》1986,99(2):337-344
Uranium(VI) reacts with 1-(2-thiazolylazo)-2-naphthol to form a red-coloured chelate in the pH range 5.3–7.2, maintained by 0.04 M acetate buffer. Absorbance of the sparingly soluble complex, solubilized and stabilized by Triton X-100, is measured after 30 min and it is stable for at least 16 hours. The complex exhibits maximum absorbance at 575 and 625–630 nm, but absorbance at longer wavelengths is not stable. The 12 complex obeys Beer's law over the concentration range 0.4–6.4 g of uranium(VI) per cm3, has molar absorptivity 3.36·104 dm3·mol–1·cm–1, Sandell sensitivity 7.0 ng·cm–2, formation constant (log K) 9.32 and coefficient of variation ±0.77%. Effect of 60 ions has been studied and selectivity improved considerably in presence of CDTA. The method has been applied for determination of uranium content in a rock sample. 相似文献
15.
I. C. Pius M. M. Charyulu C. K. Sivaramakrishnan S. K. Patil 《Journal of Radioanalytical and Nuclear Chemistry》1994,187(1):57-65
Distribution ratios of Pu(IV) between 7.5M HNO3+0.75M H3PO4+0.3M H2SO4 media and a macroporous anion-exchange resin Amberlyst A-26 (MP) increased from 40 to 250 when 1M aluminium nitrate was added to the aqueous medium. When 1M ferric nitrate was used in place of aluminium nitrate the distribution ratio further increased to 850. The 10% Pu(IV) breakthrough capacities with a 5 ml bed resin column, using synthetic feed solutions containing 1M aluminium nitrate, were 1.4 g l–1, 3.2 g l–1 at flow rates of 30 ml per hour and 10 ml per hour, respectively. The corresponding 10% Pu(IV) breakthrough capacities in the presence of 1M ferric nitrate were 8.5 g l–1 and 12.8 g l–1. More than 97% of plutonium could be recovered from actual analytical phosphate waste solutions. 相似文献
16.
Ramaraghavulu Rajavaram Rao V. Koteswara Devarayapalli K. C. Yoo Kisoo Nagajyothi P. C. Shim Jaesool 《Research on Chemical Intermediates》2021,47(2):637-648
Research on Chemical Intermediates - The green synthesis of nanoparticles using plant-based materials as an alternative to chemical and physical routes provides economic and environmental benefits.... 相似文献
17.
Pack SP Heo TH Devarayapalli KC Makino K 《Analytical and bioanalytical chemistry》2011,401(2):667-676
Although a DNA-immobilized packed-column (DNA-packed column), which relies on sequence-dependent interactions of target DNA
or mRNA (in the mobile phase) with DNA probes (on the silica particle) in a continuous flow process, could be considered as
an alternative platform for quantitative analysis of specific DNA to DNA chip methodology, the performance in practice has
not been satisfactory. In this study, we set up a more efficient quantitative analysis system based on a DNA-packed column
by employing a temperature-gradient strategy and DMSO-containing mobile phase. Using a temperature-gradient strategy based
on T
m values of probe/target DNA hybridizations and DMSO (5%)-containing mobile phase, we succeeded in the quantitative analysis
of a specific complementary target distinguishable from non-complementary DNA oligomers or other similar DNA samples. In addition,
two different target DNA oligomers even with similar T
m values were separated and detected quantitatively by using a packed column carrying two different DNA probes. 相似文献
18.
Devarayapalli KC Pack SP Kamisetty NK Nonogawa M Watanabe S Kodaki T Makino K 《Analytical and bioanalytical chemistry》2007,388(4):919-928
DNA chips prepared on a flat glass surface have unavoidable drawbacks when used for quantitative analysis. In an attempt to
overcome this problem, we constructed an HPLC-type system suitable for quantitative analysis that enables base sequence- and
T
m-dependent DNA oligomer separation in a flow system. A small open tubular capillary column (300-mm × 100-μm I.D.) was used.
The DNA oligomers used as probes had an amino group at the 5′-end and were immobilized on the inner silica surface of the
capillary column which had been sequentially treated with 3-aminopropyltriethoxysilane, butyltrimethoxysilane, and disuccinimidylglutarate.
Using the combination of probe-immobilized column placed in a column oven equipped with temperature gradient function, a nano-flow-controllable
pump, a small sample-loading injector, and a capillary-fitted UV detector, we succeeded in separating complementary and non-complementary
DNA oligomers in specific and quantitative modes. We also designed a temperature gradient strategy for efficient separation
of target DNA oligomers in DNA mixture samples. Using a column carrying two different probes with similar T
m values, their complementary target DNA oligomers were also separated and detected. The developed DNA open tubular capillary
column system investigated in the present study could be further improved as an alternative tool to DNA chips to be used for
the quantitative analysis of DNA or mRNA samples.
Kamakshaiah Charyulu Devarayapalli and Seung Pil Pack contributed equally to this paper. 相似文献
19.
M. M. Charyulu C. V. Karekar V. K. Rao P. R. Natarajan 《Journal of Radioanalytical and Nuclear Chemistry》1991,148(2):339-347
The dissolution of carbide fuels was tried with the aid of various oxidants like H2O2, NaBiO3, (NH4)2Ce(NO3)6, (NH4)2S2O8, and AgO in nitric acid medium. During the dissolution, the carbon dioxide liberated has been measured. Among the oxidants studied, H2O2 and NaBiO3 appeared to be more effective for dissolution of carbides. 200–300 mg of sintered uranium carbide sample dissolved within 15 minutes in the presence of oxidants H2O2 or NaBiO3. Mixed carbide sample (70%) was dissolved within 30 min, whereas plutonium carbide required more than one hour. From the resulting solutions uranium and plutonium could be determined by conventional redox methods. More than 97% of plutonium could be recovered and purified from the resulting carbide solutions by conventionally used anion exchange method. 相似文献
20.
G. R. Mahajan M. M. Charyulu V. K. Rao P. R. Natarajan 《Journal of Radioanalytical and Nuclear Chemistry》1985,96(1):1-12
An improved method for the determination of plutonium in an aliquot using cerium/IV/ as an oxidant is reported. Plutonium is oxidized quantitatively to plutonium/VI/ in nitric acid medium by cerium/IV/, the excess of which is chemically destroyed in a single step by hydrochloric acid. Plutonium/VI/ is then reduced to plutonium/IV/ with a known amount of Fe/II/, the excess of which is back titrated potentiometrically with standard dichromate. Results of analysis of 3–5 mg amounts of plutonium in aliquots containing standard plutonium nitrate solution are reliable within 0.2%. Effect of the presence of some relevant foreign ions has been studied. The application of the method for the analysis of mixtures containing various amounts of uranium and plutonium has been examined. 相似文献