Nearly uniform distribution of edges among k-subgraphs of a graph

We investigate the behavior of the function f = f(n, k, e) defined as the smallest integer with the following property: If in a graph on n vertices, the numbers of edges in any two induced subgraphs on k vertices differ by at most e, then the graph or its complement has at most f edges. One of the results states that . © 1929 John Wiley & Sons, Inc.     

The application of radiochronometry during the 4th collaborative materials exercise of the nuclear forensics international technical working group (ITWG)

Journal of Radioanalytical and Nuclear Chemistry - In a recent international exercise, 10 international nuclear forensics laboratories successfully performed radiochronometry on three low enriched...     

Ba2(VO2)(PO4)(HPO4)·H2O, a New Barium Vanadium(V) Phosphate Hydrate Containing Trigonal Bipyramidal VO5Groups

The hydrothermal synthesis, single crystal structure, and some physical properties of Ba₂(VO₂)(PO₄)(HPO₄)·H₂O, a new barium vanadium(V) phosphate hydrate, are reported. This phase is built up from one-dimensional chains of unusual VO₅trigonal bipyramids and (H)PO₄tetrahedra, fused together via V–O–P linkages. These anionic chains propagate along the polar [010] direction. 11-Coordinate barium cations and water molecules occupy the interchain regions and link the chains together. Structural data for this phase and other known barium vanadium phosphates are briefly compared. Crystal data: Ba₂(VO₂)(PO₄)(HPO₄)·H₂O,M_r=566.57, monoclinic, space groupP2₁(No. 4),a=5.0772(5) Å,b=8.724(2) Å,c=10.806(1) Å,β=90.795(8)°,V=478.6(1) ų,Z=2,R=2.65%,R_w=2.89% [147 parameters, 1893 observed reflections withI>3σ(I)].     

Determination of Total Selenium Content in Cereals and Bakery Products by Flow Injection Hydride Generation Graphite Furnace Atomic Absorption Spectrometry Applying in-situ Trapping on Iridium-Treated Graphite Platforms

A flow injection hydride generation graphite furnace atomic absorption spectrometric (FI-HG-GFAAS) method was applied to the determination of Se in Se-doped and undoped cereals and bakery products. For the purpose of doping, the soils used for the cultivation of the cereals were dosed with Se-doped foliar fertilizers. The samples were dissolved in a mixture of HNO₃ and H₂O₂ solutions using microwave-assisted digestion. The decomposition of H₂Se generated from the sample solutions and the trapping of elemental Se were performed at a temperature of 300°C on an Ir-pretreated integrated graphite platform of a transversally heated graphite atomizer (THGA). For release of the trapped Se within a fairly short atomization time (5s), an atomization temperature of 2200°C was observed to be optimal. The overall efficiency of hydride generation, transport and trapping was 86%.The upper limit of the linear dynamic range of calibration was 10µgL^–1, which corresponds to 0.5µgg^–1 for solid samples. Recovery of the samples spiked with Se^VI solutions was found to be 93±6% on average. The relative standard deviation of the determinations was less than 8%. The limit of detection was found to be 0.06µgL^–1, corresponding to 3ngg^–1 for solid samples. The accuracy of the method was verified with the use of IAEA-155 (whey powder) certified reference material. End-capped THGA tubes resulted in an extension of the linear calibration range compared to that of standard THGAs.The Se content in bakery products made of undoped cereals ranged from 7.7 to 68ngg^–1 (wet weight) in 18 samples, whereas the Se content of the corresponding cereals was found to be below 100ngg^–1 (wet weight). The Se level of cereals grown on soils treated with Se-doped fertilizers ranged from 128 to 1046ngg^–1 (wet weight), and it depended linearly on the Se concentration of the corresponding foliar fertilizer.     

trans-Parinaric acid as a versatile spectroscopic label to study ligand binding properties of bovine beta-lactoglobulin

Advantageous spectroscopic properties of the plant derived polyunsaturated trans-parinaric acid (tPnA) was demonstrated in obtaining valuable data on the ligand binding characteristics of the lipocalin member bovine beta-lactoglobulin A (BLG-A). Titration of the protein with tPnA resulted in the appearance of an intense negative induced circular dichroism (CD) band and bathochromic shift of the ultraviolet (UV) peak of the ligand. The extrinsic optical activity was interpreted by the chiral contribution of the allylic axial CH bonds of tPnA to the pi-pi(*) transition of the planar tetraene chromophore. Analysis of the series of induced CD curves obtained by CD titration experiment indicated the complexation of a single ligand molecule to a uniform protein binding site. Additionally, the dramatic increase of fluorescence intensity of the lactoglobulin bound ligand suggested the hydrophobic nature of the binding site. CD and fluorescence titration data were utilized to calculate the binding constant (K(a)) of which high value ( approximately 10(6)M(-1)) refers to strong protein association of tPnA. pH dependent reversible dis- and reappearance of the induced CD signal unambigously proved the inclusion of tPnA into the central hydrophobic cavity of the lactoglobulin governed by the protonation induced conformational movement of the EF loop at the opening of the calyx. This conclusion was supported and complemented by molecular docking calculations.     

Analysis of the probability distribution method for spectrum decomposition

The probability distribution method provides a new way for spectrum deconvolution, that is especially applicable in the case of poor counting statistics. Here it has been compared with the conventional least-squares curve-fitting method. A large number of spectrum regions of a few channels were generated to simulate a spectrum containing a low intensity peak on low background, and were evaluated by both methods, to establish which method provides an unbiased estimate of the peak area in the cases examined, and on what conditions.     

Influence of fadA G203R and ΔflbA mutations on morphology and physiology of submerged Aspergillus nidulans cultures

Morphologic and physiologic changes taking place in carbon-limited submerged cultures of Aspergillus nidulans ΔflbA and fadA ^G203R strains were studied. Loss-of-function mutation of the flbA gene resulted in an altered germination with unusually thick germination tubes, “fluffy” pellet morphology, as well as a reduced fragmentation rate of hyphae during autolysis. In the fadA ^G203R mutant strain, conidiophores formed in the stationary phase of growth, and the size of pellets shrank considerably. There were no significant differences in the generation of reactive oxygen species (ROS) and in the specific catalase and superoxide dismutase activities by the tested mutants and the appropriate parental strains. Therefore, the participation of ROS or antioxidative enzymes in FadA/FlbA signaling pathways seems to be unlikely in submerged cultures. On the other hand, earlier increases in the extracellular protease and ammonia production were recorded with the ΔflbA strain, whereas the protease and ammonia production of the fadA ^G203R mutant lagged behind those of the wild-type strains. Similar changes in the time courses of the induction of γ-glutamyltranspeptidase and the degradation of glutathione were observed. These results suggest that FadA/FlbA signaling may be involved in the mobilization of protein and peptide reserves as energy sources during carbon starvation.     

Adsorption of fission products on stainless steel and zirconium

Contamination of the structural materials of nuclear reactors is a crucial question in view of radiation protection, especially, if due to some leakage, uranium and its fission products appear in the cooling water. Since it is rather difficult to obtain in situ experimental data on the actual amount of adsorbed radioactive species, the surface contamination may be quantified by measuring bulk activity concentrations of the cooling water and by calculating the amount of adsorbed material on the surfaces by using a partition coefficient. To do this, the knowledge of an appropriate adsorption isotherm is needed. Thus, our paper presents results, based on electrochemical measurements, about the extent and effect of the adsorption of certain fission products—caesium and iodide—in their ionic forms on the surface of some alloys used in the nuclear industry. Our findings allow the conclusion that the adsorption of these ions can be described by a Langmuir-type isotherm, where the saturation values correspond to surface monolayers.     

Kinetics of fission products accumulation on structural materials

The aim of the present work was to reveal the kinetics of the accumulation of some possible contaminant on the surfaces of structural materials (zirconium alloys and 08H18N10T stainless steel) in the primary circuit of Paks NPP. The kinetics of adsorption and desorption of iodide, caesium and cerium ions were investigated by quartz crystal microbalance (QCM) installed into a flow cell. The results on thin layers were confirmed by immersing experiments, using radiotracer technique and ??-spectrometry to detect the traced ions on the surfaces. Experiments were carried out in electrolyte solution which was similar to the cooling water. All measurements were carried out at room temperature. Both adsorption and desorption were found to be fast, taking only several seconds; time constants were also evaluated.