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11.
Ten sorts of charcoals were studied regarding their use as amplifier in the design of a personal dosimeter. It consists of a combination of a Makrofol detector and activated charcoal. The calibration factor for the Makrofol using the charcoals as an amplifier is about ten times higher comparing with an exposure without charcoal. The best results were obtained with Carboxen 563. The background radioactivity of charcoals must also be considered in the dosimeter's design. 相似文献
12.
Fini P Loseto R Catucci L Cosma P Agostiano A 《Bioelectrochemistry (Amsterdam, Netherlands)》2007,70(1):44-49
The interactions of Rose Bengal (RB) with alpha-cyclodextrin (alpha-CD), hydroxypropyl-beta-cyclodextrin (HP-beta-CD), hydroxypropyl-gamma-cyclodextrin (HP-gamma-CD), heptakis(2,3,6-tri-O-methyll)-beta-cyclodextrin (TM-beta-CD) were studied in aqueous solutions of 0.1 M KClO(4) and 0.1 M LiClO(4) by vis absorption, fluorescence spectroscopy as well as electrochemical measurements at 298 K. The spectrophometric results indicate that RB is included in all beta- and gamma-CDs forming complexes with a stoichiometry 1:1 whose stability is slightly higher in KClO(4) than in LiClO(4) solutions. The complex stability constants determined for salt-containing CD solutions are lower than those for water solutions. The complexation of RB with beta- and gamma-CD and the differences between the complexes obtained in the presence of the two salts were confirmed by an electrochemical study. 相似文献
13.
Fini P. Castagnolo M. Catucci L. Cosma P. Agostiano A. 《Journal of Thermal Analysis and Calorimetry》2003,73(2):653-659
Equilibrium constants and standard molar enthalpies of reaction were determined by titration calorimetry for the reaction
of 1-butanol with 2-hydroxypropyl-b-cyclodextrin (HP-b-CD) in aqueous solution at different concentrations of NaCl (0-1.9
M). The standard molar free energy and entropy changes associated to the complexation were calculated from the corresponding
equilibrium constants, K, and standard enthalpies determined experimentally. In NaCl solutions the inclusion complexes ButOH/HP-b-CD are more stable
than in water and their stability increases at increasing NaCl concentration; otherwise, the standard molar enthalpy associated
to the formation of the complexes does not change with the increasing of salt concentration. The dependence of K on NaCl concentration were used to evaluate the number of water molecules displaced from the hydration shells of HP-b-CD
and ButOH in forming complexes.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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16.
Sunil Rohilla Sushil KumarP. Aghamkar S. SunderA. Agarwal 《Journal of magnetism and magnetic materials》2011,323(7):897-902
Magnetic nanocomposites consisting of cobalt ferrite nanoparticles embedded in silica matrix were prepared by the coprecipitation method using metallic chlorides as precursors for ferrite. Subsequently composites were annealed at 100, 200 and 300 °C for 2 h. The samples were structurally characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The magnetic properties were measured in the temperature range of 10-300 K using vibrating sample magnetometer (VSM). The effects of thermal treatment on structural and magnetic properties of nanocomposites were investigated. When the samples were annealed, CoFe2O4 nanocrystallites were observed in the SiO2 matrix, whose size increases with increase in annealing temperature. The coercivity and saturation magnetization of nanocomposite (annealed at 300 °C for 2 h) are much higher than that of bulk cobalt ferrite. The realization of adjustable particle sizes and controllable magnetic properties makes the applicability of the CoFe2O4 nanocomposite more versatile. 相似文献
17.
R. Verrone L. Catucci P. Cosma P. Fini A. Agostiano V. Lippolis M. Pascale 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):475-479
Ochratoxin A (OTA) is a nephrotoxic mycotoxin produced by several fungal species, mainly Aspergillus ochraceus, A. carbonarius and Penicillium verrucosum. It contaminates many foodstuffs, particularly cereals and their derivatives, coffee, beer, wine and cocoa, and represents
a serious health threat both to humans and animals. Spectroscopic properties of OTA solutions depend on the pH, solvent polarity
and can be influenced by the presence of cyclodextrins (CDs). In this work, the effect of β-CD on spectroscopic properties
of OTA in aqueous solutions has been investigated by means of absorption and steady-state fluorescence at different pHs (range
3.5–9.5). Binding constants of OTA/β-CD inclusion complexes have been determined by applying modified Benesi-Hildebrand equation.
A 1:1 stoichiometry of OTA/β-CD complexes has been observed at all tested pHs. 相似文献
18.
T. Néda A. Szakács I. Mócsy C. Cosma 《Journal of Radioanalytical and Nuclear Chemistry》2008,277(3):685-691
The aim of this work is to study the exposure due to the radon of the patients from the dry carbon dioxide baths (mofettas)
from Harghita Băi, Romania. These mofettas consist of emanated gas with high carbon dioxide content, and proved curative effects.
The vertical and horizontal distribution of the radon activity concentration was monitored indoor, the seasonal variation,
as well as the soil radon and thoron activity concentration outdoor, in the vicinity of the bath to determine the origin of
the radon and the location of the fault through which it propagates. The equilibrium factor of the baths and the effective
dose received by the patients was also calculated. 相似文献
19.
The paper presents the main characteristics of transverse mode HCE glow discharges in spectral pure helium and neon and in a He/Ne mixture in a long perforated cylindrical cathode with an external coaxial anode. At optimum values of gas pressure, when HCE gets its climatic stage, the compact negative glow evenly “fills” the cathode cavity with maximum amplifications of current and radiation. 相似文献
20.
Roberto Grisorio Pinalysa Cosma Piero Mastrorilli Gian Paolo Suranna Cosimo Francesco Nobile 《Tetrahedron》2008,64(37):8738-8745
The preparation and properties of the first spirocyclohexane-functionalized bifluorene-based monodispersed molecular materials is described. The obtained compounds were characterized by 1H NMR, 13C{1H} NMR, IR, DSC, UV-vis and photoluminescence both in solution and in the solid state. The molecules show emissions ranging from the blue to the blue-green region, and higher glass transition temperatures and spectral stability with respect to the analogous compounds containing 9,9,9′,9′-tetrahexyl-[2,2′]-bifluorene core. The materials were used as active layers in electroluminescent devices with ITO/PEDOT-PSS/SB1-4/Ca/Al and ITO/PEDOT-PSS/SB1-4/BCP/Ca/Al configurations. 相似文献