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1.
The tape stripping technique is an experimental method frequently used for reconstruction of the in-depth distribution of various topically administered substances within the horny layer of human skin, e.g., compounds contained in sunscreens. Titanium dioxide (TiO2) nanoparticles (25–200 nm in diameter) are one such compound. Optical techniques which apply blue light are found to be suitable for reconstruction. However, the presence of particles affects the light propagation within the skin and therefore causes incorrect determination of strip thickness, leading to an improper reconstructed distribution of nanoparticle concentration revealed from the experimental data. This study evaluates the errors emerging from the use of blue (400 nm) and NIR (800 nm) radiation and finds the use of longer wavelength light more advantageous. Particles of different diameters are considered, and it is revealed that the application of small particles (25–60 nm) results in the lowest rate of error. 相似文献
2.
The Kα to Lα and Kβ to Lβ intensity ratios of seven elements have been measured following photoionization at 59.5 keV by using a Si (Li) detector
(FWHM=155 eV at 5.96 keV). The intensity ratios were determined by measuring K and L x-rays emitted from a standard target of a given element. The theoretical values of the Kα to Lα and Kβ to Lβ intensity ratios were calculated using theoretically tabulated values of shell/subshell photoionization cross sections,
fluorescence yields, Coster-Kronig transition probabilities, and radiative decay rates for ηKLi≠ and ηKLi=0. The measured values are in good agreement with theoretical results.
From Optika i Spektroskopiya, Vol. 97, No. 2, 2004, pp. 186–189.
Original English Text Copyright ? 2004 by A. Kü?ük?nder, S?ğüt, E. Kü?ük?nder, Büyükkasap.
This article was submitted by the authors in English. 相似文献
3.
?. Cerjan -Stefanovi? M. Ka?telan -Macan 《Fresenius' Journal of Analytical Chemistry》1988,331(8):811-813
Summary The relationship between the ion-exchange reaction in a column and temperature was examined in the system lead-ion exchanger resin Lewatit S 1080. Lead binding was performed with 0.01 mol/l HNO3 and elution with 4.0 mol/l HCl. The working temperature was gradually increased from 273 to 333 K. Thermostat columns were of own construction. The results were statistically analysed and graphically presented and the parameters obtained for elution curves were related to temperature. The elution curves were found to be temperature specific. The parameters such as elution band width, distribution factor, maximal volume of the eluate, maximal lead concentration in the eluate, confirmed this fact. At higher temperatures, larger volumes of elution solution were required for the elution of the same quantity of lead.
Ionenaustausch im System Blei-Kationischer Austauscher bei verschiedenen Temperaturen相似文献
4.
?. ?upi? S. Anic A. Terlecki-Bari?evi? Lj. Kolar-Ani? 《Reaction Kinetics and Catalysis Letters》1995,54(1):43-49
Behavior of the Bray-Liebhafsky oscillatory reaction in the presence of acid-base polymers with and without ferric ions is analyzed. The influence of hydrogen ions on the overall reaction is shown. 相似文献
5.
?. Cerjan-Stefanovi? F. Bri?ki M. Ka?telan-Macan 《Fresenius' Journal of Analytical Chemistry》1991,339(9):636-639
Summary Waste waters of film processing plants are rich with silver. Part of the silver is regenerated electrochemically, but the rest (0.5 g) remains in waste waters and is sent to sewers. This is a bad politic from both the environmental (toxic waste waters) and the economical point of view (a waste of silver). In this work, the silver was isolated by ion-exchange resins and then concentrated by microorganisms. For exchange of silver, Ionenaustauscher I, II and IV were used. The batch method was used to obtain a static equilibrium. Silver elution from exchangers is based on silver transformation to a stable cation or anion complex. By varying the ligands, pH and eluent concentrations, optimum elution is found at 1 mol/l Na2S2O3, 1 mol/l NH3, 2 mol/l HNO3 and 1 mol/l (NH2)2CO. The concentration of silver in the eluent is about 50 mg/l. The silver ion uptake from solutions after ion exchange by mixed bacterial culture isolated from photographic waste water drain and pure bacterial cultures Escherichia coli 3009 and Bacillus subtilis 3053. was studied. Experiments were carried out in submerse culture at pH 7 with different Ag+ concentrations (4, 8 and 40 mg/l) on a rotary shaker (100 rpm) at 37°C. At the lower Ag+ concentrations a good growth and simultaneous removal of Ag+ from the solutions was achieved. At Ag+ concentration of 40 mg/l growth and removal of Ag+ by mixed and pure culture differed significantly. Thus mixed bacterial culture grew well and at the same time removed efficiently Ag+ (approximately 90%) from medium. Pure bacterial cultures on the contrary were unable to grow at 40 mg/l Ag+, though their biomass showed to be an effective biosorbent for Ag+ (approximately 80% of Ag+ removal). 相似文献
6.
Novikov V. S. Kuznetsov S. M. Kuzmin V. V. Prokhorov K. A. Sagitova E. A. Darvin M. E. Lademann J. Ustynyuk L. Yu. Nikolaeva G. Yu. 《Doklady Physics》2021,66(9):257-263
Doklady Physics - The dependence of Raman spectra of the molecules containing polyene chains on the conjugation length, structure of side and end groups, and isomer type is analyzed theoretically. 相似文献
7.
Yanina I. Yu. Schleusener J. Lademann J. Tuchin V. V. Darvin M. E. 《Optics and Spectroscopy》2020,128(6):759-765
Optics and Spectroscopy - The effect of glycerol solutions of different concentrations and exposure times on the optical clearing efficiency in intact pig skin has been studied in the analysis of... 相似文献
8.
?. Hammer 《The European physical journal. Special topics》2009,178(1):5-12
This article provides an overview of current and prospected climate changes, their causes and implied threats, and of a possible
route to keep the changes within a tolerable level. The global mean temperature has up to 2005 risen by almost 0.8°C, and
the change expected by 2100 is as large as glacial-interglacial changes in the past, which were commonly spread out over 10000
years. As is well known, the principle actor is man-made CO2, which, together with other anthropogenic gases, enhances the atmosphere’s greenhouse effect. The only man-made cooling agent
appears to be atmospheric aerosols. Atmospheric CO2 has now reached levels unprecedented during the past several million years. Principal threats are a greatly reduced biodiversity
(species extinction), changes in the atmospheric precipitation pattern, more frequent weather extremes, and not the least,
sea level rise. The expected precipitation pattern will enhance water scarcity in and around regions that suffer from water
shortage already, affecting many countries. Sea level rise will act on a longer time scale. It is expected to amount to more
than 50 cm by 2100, and over the coming centuries the potential rise is of the order of 10 m. A global-mean temperature increase
of 2°C is often quoted as a safe limit, beyond which irreversible effects must be expected. To achieve that limit, a major,
rapid, and coordinated international effort will be needed. Up to the year 2050, the man-made CO2 releases must be reduced by at least 50%. This must be accompanied by a complete overhaul of the global energy supply toward
depending increasingly on the Sun’s supply of energy, both directly and in converted form, such as wind energy. Much of the
information and insight available today has been generated by the Intergovernmental Panel on Climate Change (IPCC), in particular
its Fourth Assessment Report of 2007, which greatly advanced both public attention and political action. 相似文献
9.
?. ?liwczyński 《Opto-Electronics Review》2009,17(4):318-324
In the paper, the factors affecting the accuracy of calculating the optical filter group delay basing on the measured power
transmission characteristic are analyzed. Having the phase characteristic of the filter recovered from its transmission, the
group delay is usually calculated via differentiation. The new, direct formula is proposed giving more accurate results when
the characteristic of the filter is available in the limited frequency range. Also the limitations arising from the noise
of the optical spectrum analyzer are examined. 相似文献
10.
Photonic crystal behavior of a rotating Bose-Einstein condensate with a triangular vortex lattice is reviewed and a scheme for getting much wider band gaps is proposed. It is shown that photonic band gaps can be widened an order of magnitude more by using a Raman scheme of index enhancement, in comparison to previously considered upper level microwave scheme. 相似文献