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Since the beginning of using liquid scintillators for gamma-neutron separation, there have been many articles dealing with long-term degradation especially due to oxygen presented during scintillator encapsulation. The effect of aging of liquid organic scintillators namely EJ301, EJ309 (both Eljen Technology), and new custom-made cocktails based on 1-Phenyl-3-(2,4,6-trimethylphenyl)-2-pyrazoline and 2,5-Bis(5-tert-butyl-benzoxazol-2-yl)thiophene fluors were investigated for more than half a year. The research was focused on the Compton edge shifting of gamma particles since the position is proportional to the light yield of the selected scintillator. Furthermore, the gamma-neutron separation was observed and quantified using FOM (Figure Of Merit) for samples prepared and filled under normal and nitrogen atmosphere during the mentioned period. All stated parameters of liquid scintillator NE213 manufactured by Nuclear Enterprises Limited opened more than three decades ago were measured and used for comparison.

The manuscript is focused on possible usage of a simple α – βγ discriminating circuit applying a mixture of inorganic scintillation powders and Li-6 as a converter as a substitution of handheld neutron detector based on the He-3 isotope. Various mixtures of scintillators and Li-6 were tested from which the zinc sulfide activated by silver and lanthanum bromide oxide doped by cerium seemed to be the most promising scintillator for thermal neutron detection due to the biggest difference in magnitude of pulses created by alpha/gamma radiation. Furthermore, the influence of PMMA (polymethyl methacrylate) optical carrier or additional scintillation matrix formed by polystyrene plastic scintillator on the signal under different types of radiation was investigated.

Rapid determination of selected gross alpha and beta emitters in environmental matrices by solid-state scintillation technique is discussed. This method is based on sample treatment using microwave reactor and direct measurement of digested products using powder scintillator and alkaline solution as a substitute for traditional liquid scintillation cocktail. The selected group of radionuclides was chosen with respect to their use in nuclear industry, high radiotoxicity, and the possibility of potential misuse. The work aimed at verifying the connection of microwave decomposition using alkaline solution with solid-state scintillation using a powder scintillator YAP:Ce together with an alkaline medium.

Observables on quantum structures can be seen as generalizations of random variables on a measurable space $$(\Omega , \mathcal {A})$$ for the case when $$\mathcal {A}$$ is not necessarily a Boolean algebra. The present paper investigates an extending of the usual pointwise sum of random variables onto the set of bounded observables on a $$\sigma $$ -distributive lattice effect algebra E. We describe conditions under which this operation, so-called sum $$x+y$$ of observables x, y, preserves continuity of spectral resolutions of x, y. We show how the spectrum $$\sigma (x+y)$$ depends on spectra $$\sigma (x)$$ , $$\sigma (y)$$ , and we provide a relation between the meager part $$x_m$$ and the dense part $$x_d$$ of an observable x.

In this article the properties of four new luminophores, from the group of bifluorenes and other substances with multiple aromatic rings, were measured and studied for possible use in liquid scintillation, namely 1-phenyl-3-(2,4,6-trimethyl-phenyl)-2-pyrazoline, 2,2′,7,7′-tetrakis(N,N-diphenyl-amino)-9,9′-spirobifluorene, 2-(4-biphenylyl)-6-phenylbenzoxazole and 9,9′-bifluorenyl. The measurement was also done for the most commonly used luminophore (2,5-diphenyloxazole (PPO)). To improve counting efficiency the wavelength shifters were added to scintillation cocktail in particular POPOP and bis-MSB. The main effort was focused on the determination of sample counting efficiency of experimental cocktails using radionuclides Am-241, Sr-90 and H-3, especially for acidic, alkaline and neutral water solutions. The results were compared with the commercially used Aqualight scintillation cocktail.

This paper deals with the study of 1-phenyl-3-(2,4,6-trimethyl-phenyl)-2-pyrazoline, 2,2´,7,7´-tetrakis(N,N-diphenyl-amino)-9,9´-spirobifluorene, 2-(4-biphenylyl)−6-phenylbenzoxazole and 9,9´-bifluorenyl as possible replacements of the existing and most widely used luminophore (2.5-diphenyloxazole (PPO)) in contemporary scintillators. The study is focused on the determination of emission wavelength, concentration optimization, the influence of the wavelength shifters POPOP and bis-MSB. In addition, the response to alpha and beta radiation were measured, in particular, the pulse length index (PLI) was determined. Finally, yet importantly, the effect of emulsifiers on the shape of the spectrum and the solubility of the aqueous phase was tested. The results obtained were compared with the commercially available Aqualight scintillation cocktail.

Group coextensions of monoids, which generalise Schreier-type extensions of groups, have originally been defined by P.A. Grillet and J. Leech. The present paper deals with pomonoids, that is, monoids that are endowed with a compatible partial order. Following the lines of the unordered case, we define pogroup coextensions of pomonoids. We furthermore generalise the construction to the case that pomonoids instead of pogroups are used as the extending structures. The intended application lies in fuzzy logic, where triangular norms are those binary operations that are commonly used to interpret the conjunction. We present conditions under which the coextension of a finite totally ordered monoid leads to a triangular norm. Triangular norms of a certain type can therefore be classified on the basis of the presented results. Mathematics Subject Classification (2010): 06F05, 03B52. Keywords: Partially ordered monoid, coextension of pomonoids, triangular norm

The natural question about the sum of observables on $$\sigma $$ -complete MV-effect algebras, which was recently defined by A. Dvurecenskij, is how it affects spectra of observables, particularly, their extremal points. We describe boundaries for extremal points of the spectrum of the sum of observables in a general case, and we give necessary and sufficient conditions under which the spectrum attains these boundary values. Moreover, we show that every bounded observable x on a complete MV-effect algebra E can be decomposed into the sum $$x=\tilde{x}+x'$$ , where $$\tilde{x}$$ is the greatest sharp observable less than x and $$x'$$ is a meager and extremally non-invertible observable.

Rapid bioassay methods have been mainly proposed for the sequential measurements of actinides in human blood, bone marrow and urine. The method involves sample treatment using microwave digestion techniques followed by direct measurement of digested products using powder scintillator and alkaline solution as a replacement for traditional liquid scintillation cocktail. The selected group of radionuclides was chosen due to their occurrence in the nuclear fuel cycle, nuclear accident, high radiotoxicity, and the possibility of potential misuses, such as dirty bombs. The work aimed at verifying the connection of microwave digestion using alkaline solution with solid-state scintillation using a powder scintillator YAP:Ce together with an alkaline medium.

Liquid organic scintillators are important materials for measurements of neutron radiation. This work aims to develop and optimize the composition of liquid organic scintillators so they can be used for fast neutron spectrometry . As neutron radiation is usually accompanied with γ ray radiation, this work is focused on γ /n discrimination. It is shown that Di-iso-propylnaphthalene Mixed Isomers and 1-Methylnaphthalene are capable of good γ /n discrimination. Afterwards, the concentration of luminophores is varied and it is shown that the PYR and THIO luminophores with concentrations above 3 g/l have Figure of Merit FOM > 1 . 27 above the energy threshold of 0 . 14 MeVee and 0 . 17 MeVee , respectively.

In (Riecanova and Zajac in Rep. Math. Phys. 70(2):283–290, 2012) it was shown that an effect algebra E with an ordering set $\mathcal{M}$ of states can by embedded into a Hilbert space effect algebra $\mathcal{E}(l_{2}(\mathcal{M}))$ . We consider the problem when its effect algebraic MacNeille completion $\hat{E}$ can be also embedded into the same Hilbert space effect algebra $\mathcal {E}(l_{2}(\mathcal{M}))$ . That is when the ordering set $\mathcal{M}$ of states on E can be extended to an ordering set of states on $\hat{E}$ . We give an answer for all Archimedean MV-effect algebras and Archimedean atomic lattice effect algebras.

The existence of a non-trivial singular positive bilinear form Simon (J. Funct. Analysis 28, 377-385 (1978)) yields that on an infinite-dimensional complex Hilbert space the set of bilinear forms is richer than the set of linear operators . We show that there exists an structure preserving embedding of partially ordered groups from the abelian po-group of symmetric bilinear forms with a fixed domain D on a Hilbert space into the po-group of linear symmetric operators on a dense linear subspace of an infinite dimensional complex Hilbert spacel (2)(M). Moreover, if we restrict ourselves to the positive parts of the above mentioned po-groups, we can embed positive bilinear forms into corresponding positive linear operators.

We study measures, finitely additive measures, regular measures, and $\sigma$-additive measures that can attain even infinite values on the quantum logic of a Hilbert space. We show when particular classes of non-negative measures can be studied in the frame of generalized effect algebras.

This paper describes a method for rapid determination of gross alpha and beta activity in seafood using liquid scintillation counting and microwave digestion for fast sample decomposition. The general group of seafood was divided into two groups based on its structure, whether it has shell or not. The selected group of radionuclides was chosen with respect to military significance, radiotoxicity, and possibility of potential misuse. 90Sr and 239Pu were selected as model radionuclides.

The paper describes the extraction characteristics of selected alpha radionuclides by means of extraction chromatography of the selected resins—TRU, TEVA, UTEVA, DN and DIPHONIX. The aim was to investigate the choice of mobile-phase and especially the effect on the percentage of extraction, the conditions leading to degradation of extraction sorbents and also to determine the synergistic effect of different cations added to mobile-phase.

Tense operators in effect algebras play a key role for the representation of the dynamics of formally described physical systems. For this, it is important to know how to construct them on a given effect algebra $$ E$$ and how to compute all possible pairs of tense operators on $$ E$$ . However, we firstly need to derive a time frame which enables these constructions and computations. Hence, we usually apply a suitable set of states of the effect algebra $$ E$$ in question. To approximate physical reality in quantum mechanics, we use only the so-called Jauch–Piron states on $$ E$$ in our paper. To realize our constructions, we are restricted on lattice effect algebras only.

We study the so-called pairwise summable generalized effect algebras and show some conditions under which they are generalized MV-effect algebras. Moreover, we give a necessary and sufficient condition for finite antichains of elements in pairwise summable generalized effect algebras under which they are sets of atoms of sub-generalized effect algebras, which are generalized MV-effect algebras in their own right. Simultaneously, we give counterexamples which show properties of those antichains which are not necessary or sufficient to be atoms of such generalized MV-effect algebras.

We study positive bilinear forms on a Hilbert space which are neither not necessarily bounded nor induced by some positive operator. We show when different families of bilinear forms can be described as a generalized effect algebra. In addition, we present families which are or are not monotone downwards (Dedekind upwards) $\sigma$-complete generalized effect algebras.

A significant property of a generalized effect algebra is that its every interval with inherited partial sum is an effect algebra. We show that in some sense the converse is also true. More precisely, we prove that a set with zero element is a generalized effect algebra if and only if all its intervals are effect algebras. We investigate inheritance of some properties from intervals to generalized effect algebras, e.g., the Riesz decomposition property, compatibility of every pair of elements, dense embedding into a complete effect algebra, to be a sub-(generalized) effect algebra, to be lattice ordered and others. The response to the Open Problem from Riea?anova and Zajac (2013) for generalized effect algebras and their sub-generalized effect algebras is given.

We continue in a direction of describing an algebraic structure of linear operators on infinite-dimensional complex Hilbert space ℋ. In [Paseka, J.- -Janda, J.: More on PT-symmetry in (generalized) effect algebras and partial groups, Acta Polytech. 51 (2011), 65-72] there is introduced the notion of a weakly ordered partial commutative group and showed that linear operators on H with restricted addition possess this structure. In our work, we are investigating the set of self-adjoint linear operators on H showing that with more restricted addition it also has the structure of a weakly ordered partial commutative group.

Analysis of alpha and beta emitters in aerosol filters and swabs of different materials by liquid scintillation counter is discussed. This method appears suitable for fast determination of activity of radionuclides due to direct alpha and beta separation, measurement in 4π geometry and without sample treatment. The selected group of radionuclides was chosen with respect to military significance, radiotoxicity, and possibility of potential misuse. 90Sr and 239Pu were selected as model radionuclides. Three types of filters were examined, and the attention was also focused on optimizing the type and volume of LSC cocktail. The efficiencies for 239Pu and 90Sr were 90% and 79%, respectively. This method was the most effective for the glass fiber filters measured with the MaxiLight cocktail.

This method describes electrodeposition of selected group of alpha-emitting radionuclides such as the method suitable for measurement by means of solid-state alpha spectrometry. The effect of volume and pH of electrolyte, distance of electrodes, current and plating time in presence of ammonium oxalate, hydroxyl ammonium sulfate, ammonium sulfate, and DTPA (diethyltriaminopentaacetic acid) versus different alpha-emitting radionuclides was observed in order to optimize the conditions and to obtain the maximum yield. The chemical yield of this method is approximately by 4% higher than for the Talvitie’s method and it corresponds with study of Lee MH et al. The group of isotopes that were studied includes 232U, 238Pu, 241Am, 243Am, and 244Cm.

We continue in the direction of our paper on PT-Symmetry in (Generalized) Effect Algebras and Partial Groups. Namely we extend our considerations to the setting of weakly ordered partial groups. In this setting, any operator weakly ordered partial group is a pasting of its partially ordered commutative subgroups of linear operators with a fixed dense domain over bounded operators. Moreover, applications of our approach for generalized effect algebras are mentioned.