The analytical technique for instrumental neutron activation analysis, when applied to geological materials, is improved by introducing an lectromagnetic field between sample and detector. This field lowers the bremsstrahlung background intensity in the gamma-spectrum, by reducing the number of beta-particles reaching the detector. Thus, precision, accuracy and lower detection limit are improved. In this work the technique has been used on an alkalisyenite and on meteoritic material, rocks containing high quantities of sodium and iron, respectively. After neutron irradiation, the induced nuclides24Na and59Fe are responsible for high bremsstrahlung interference, which under normal analytical conditions would mask any X-ray or gamma-ray peaks of interest. The technique is easily applied to multielement analysis of geological and biological material (although the latter is not treated in this paper). It can be combined with sophisticated spectrum-treating techniques such as spectrum stripping and spectrum smoothing, or coincidence-anticoincidence circuits.
The paper deals with the strategies of using the proper names, intertextuality and allegory in the genre of neolatin bucolic poetry with special regards to Boccaccio’s eclogue Faunus. The study examines the possibilities of using the ancient code as an intertextual necromancy, the position of ego and identity in the poem, the tension between acustic and visual elements. The meaning or association-basis of the given name (mask) has special effect on the enrichment of the poetical imaginary, while the name also influences the context and the global allegorical level of the poem. The poet often uses pseudoetimological, mitological or historical approaches in the levelling of the poem, which is the part of his selfcanonisation strategies, while the genre of eclogue seems to be the mouthpiece of power.
During his lifetime hundreds of portraits were made of Ferenc Liszt in a great diversity of genres by foreign and Hungarian artists alike. Medallists also commemorated Liszt on the centenary of his birth in 1911. Numerous one-sided medals and plaques were cast or struck but some of them, like that of Fülöp Ö. Beck, do have motives on the reverse as well. Beck had been working on a Liszt plaque for years. The starting inspiration was the Liszt mask he had personally received from the aging sculptor Alajos Stróbl. He prepared several designs for the reverse. The series of the reverse variations is significant because Beck’s aim was not to present an allegory about Liszt’s figure or create symbols for his compositions as was the custom in medal art, but to capture the essence and the infinity of music. Fülöp Ö. Beck’s Liszt plaque is an outstanding exponent not only of the Hungarian but the international medal art.
Poly-vinyl-chloride (PVC)-polyethylene (PE) alloys were prepared by melt blending using both low- and high-density polyethylene without applying a compatibilizer. The PVC and the PE are incompatible polymers; in spite of this fact stable microheterogeneous materials were obtained. Mechanical methods e.g. tensile tests generally (measured in the usual concentration range) do not support any compatibility. At higher concentrations, the incompatible parts mask the effect of molecular mixing, easily detected at low PE contents. Dynamic mechanical (DMA), differential scanning calorimetric tests were carried out. Glass transition temperatures were determined by both methods. DMA tests were made at four frequencies, and the energy of activation of PVC main transition was also calculated. The decrease of glass-transition temperatures and energy of activation show that there is a slight mixing of the polymers. Specimens were also investigated by infrared method. From the results of IR spectra, grafting reaction of PE can be assumed onto the PVC because of its dehydrochlorination.
A simple, rapid and selective separation procedure of gold based on its extraction with 1-phenyl-3-methyl-4-trifluoroacetylpyrazolone-5
has been developed. The dependence of the distribution ratio of gold on the pH of aqueous solutions, concentration of hydrochloric,
nitric and perchloric acids and the organic solvents has been investigated. Decontamination factors for a number of metal
ions with respect to gold are reported. Excellent separation of gold is obtained from many elements including noble metals.
Citrate, cyanide, iodide, thiosulfate and thiourea completely mask gold, whereas oxalate does not interfere. Solutions of
1 M HCl, 0.2 M KCN, and the buffer of pH 0.8 readily strip gold from the organic phase. Some useful analytical applications
of this procedure are discussed.
Extraction of mercury with 3-methyl-1-phenyl-4-trifluoroacetyl-pyrazolin-5-one /FAP/ in chloroform has been described. Maximum extraction /97.3%/ and a distribution coefficient /D/ of 36.5 have been achieved at pH 8. Among the anions tested, thiourea, thiosulphate and cyanide mask the extraction of mercury. Solution of O. 2M KCN was found most suitable stripping agent for mercury. Decontamination data show that mercury can be separated from toxic elements arsenic, cadmium, antimony and thallium; and from other metal ions i. e. Ga/III/, In/III/, Ge/IV/, Sn/II/, Fe/II/, Ir/IV/ and Pt/IV/. A few separations of analytical and radiochemical importance have been discussed.
A simple solvent extraction procedure is reported for the sequential separation of mercury(II), cadmium(II) and zinc(II). Mercury is separated first using 1,3-diphenyl-2-thiourea in chloroform at an overall acidity of 0.3M HCl. Then cadmium separated using the same reagent at pH 10 into dichloromethane. The zinc which is remaining in the aqueous phase is then quantitatively extracted into toluene-cyclohexanol mixture using 2-mercaptobenzoxazole. Suitable stripping solutions have been proposed for the re-extraction of these metal ions for their subsequent estimations. The method has been made highly selective by the use of appropriate masking agents and has been applied in conjunction with estimation procedures for the determination of these metal ions in city waste incineration ash (CRM 176), mercuric chloride (A. R. grade) and in magnesium alloy samples.
It is necessary in most radiochemical studies to check periodically the efficiency of the detector with a standard or reference
source to ensure its constancy. This can lead to a large number of readings which can best be analysed graphically by means
of cumulative summation. Minor abrupt changes in counter performance can often be determined by retrospective examination
of cusums. Alternatively in an on-going situation the reference source readings may be plotted as they are taken and a significant
change detected comparatively rapidly with a V-mask. The standard deviation used in tests of significant change has in practice
been found to be greater than that expected simply from the randomness of the disintegration process. The point of change
can often be located precisely so that it should be possible if necessary to correct other measurements with the detector.
A new and simple method for selective spectrophotometric determination of uranium(VI) with 4-(2-pyridylazo)resorcinol (PAR) and N-octylacetamide into benzene over pH 7.0–9.0 is described. The molar absorptivity of the complex with 9 different amides is in the range of (0.40–3.2)·104 1·mol–1·cm–1 at the absorption maximum. Out of these, the most sensitive compound N-octylacetamide (OAA) was chosen for detailed studies in the present investigation. The detection limit of the method is 0.008 g U·ml–1. The system obeys Beer's law in the range of 0–5 g U·ml–1. The method is free from interferences of most of the common metal ions except vanadium(V) and copper(II), which are masked by proper masking agents. The composition of the complex is determined by curve-fitting method. The method has been applied for the recovery of the metal from rock samples and synthetic mixtures.
Neutron Activation Analysis is a sensitive technique for the determination of more than seventy elements at the trace concentrations.
The NAA analysis of biological and environmental matrices suffers from interferences caused by the presence of high concentrations
of activated salts in these matrices. The high gamma-ray activities of these activated salts mask the low gamma-ray activities
of short half-lived isotopes (e.g.,66Cu,56Mn,28Al and52V) necessitating the rapid separation of trace metals from high concentrations of salts. Poly-5-vinyl-8-hydroxyquinoline has
been used to develop a new method to rapidly and quantitatively precipitate aluminum, copper, vanadium and manganese from
neutron-activated biological and environmental matrices.