32 research outputs found
Status and New Data of the Geochemical Determination of the pp-Neutrino Flux by LOREX
LOREX LORandite EXperiment addresses the determination of the solar pp neutrino flux during the last four million years by exploiting the reaction 205 Tl Ī½ e ā 205 Pb e ā with an incomparably low-energy threshold of 50 keV for the capture of solar neutrinos. The ratio of 205 Pb/ 205 Tl atoms in the Tl-bearing mineral lorandite provides, if corrected for the cosmic-ray induced background, the product of the flux of solar neutrinos and their capture probability by 205 Tl, averaged over the age of lorandite. To get the mean solar neutrino flux itself, four problems have to be addressed: 1 the geological age of lorandite, 2 the amount of background cosmicray-induced 205 Pb atoms which strongly depends on the erosion rate of the lorandite-bearing rocks, 3 the capture probability of solar neutrinos by 205 Tl and 4 the extraction of lorandite and the appropriate technique to "count" the small number of 205 Pb atoms in relation to the number of 205 Tl atoms. This paper summarizes the status of items 1 age and 3 neutrino capture probability and presents in detail the progress achieved most recently concerning the items 2 background/erosion and 4 "counting" of 205 Pb atoms in lorandite
Corrigendum to "European contribution to the study of ROS:A summary of the findings and prospects for the future from the COST action BM1203 (EU-ROS)" [Redox Biol. 13 (2017) 94-162]
The European Cooperation in Science and Technology (COST) provides an ideal framework to establish multi-disciplinary research networks. COST Action BM1203 (EU-ROS) represents a consortium of researchers from different disciplines who are dedicated to providing new insights and tools for better understanding redox biology and medicine and, in the long run, to finding new therapeutic strategies to target dysregulated redox processes in various diseases. This report highlights the major achievements of EU-ROS as well as research updates and new perspectives arising from its members. The EU-ROS consortium comprised more than 140 active members who worked together for four years on the topics briefly described below. The formation of reactive oxygen and nitrogen species (RONS) is an established hallmark of our aerobic environment and metabolism but RONS also act as messengers via redox regulation of essential cellular processes. The fact that many diseases have been found to be associated with oxidative stress established the theory of oxidative stress as a trigger of diseases that can be corrected by antioxidant therapy. However, while experimental studies support this thesis, clinical studies still generate controversial results, due to complex pathophysiology of oxidative stress in humans. For future improvement of antioxidant therapy and better understanding of redox-associated disease progression detailed knowledge on the sources and targets of RONS formation and discrimination of their detrimental or beneficial roles is required. In order to advance this important area of biology and medicine, highly synergistic approaches combining a variety of diverse and contrasting disciplines are needed
Conversion of Parameters Among Variants ofĀ Scatchardās Neutral-Electrolyte Model for Electrolyte Mixtures that Have Different Numbers of Mixing Terms
Arsenic removal from water by adsorption ā a short review
Bosnjakovic, J., PaviÄeviÄ V., RadojeviÄ V., SokoloviÄ J., Arsenic removal from water by adsorption ā a short review, XIV International Mineral Processing and Recycling Conference, 12-14 May 2021, Belgrade, Serbie, 381-388
Erosion rate study at the Allchar deposit (Macedonia) based on radioactive and stable cosmogenic nuclides (26Al, 36Cl, 3He, and 21Ne)
This paper focuses on constraining the erosion rate in the area of the Allchar Sb-As-Tl-Au deposit (Macedonia). It contains the largest known reserves of lorandite (TlAsS2), which is essential for the LORanditeEXperiment (LOREX), aimed at determining the long-term solar neutrino flux. Because the erosion history of the Allchar area is crucial for the success of LOREX, we applied terrestrial in situ cosmogenic nuclides including both radioactive (26Al and 36Cl) and stable (3He and 21Ne) nuclides in quartz, dolomite/calcite, sanidine, and diopside. The obtained results suggest that there is accordance in the values obtained by applying 26Al, 36Cl, and 21Ne for around 85% of the entire sample collection, with resulting erosion rates varying from several tens of m/Ma to ā¼165 m/Ma. The samples from four locations (L-8 CD, L1b/R, L1c/R, and L-4/ADR) give erosion rates between 300 and 400 m/Ma. Although these localities reveal remarkably higher values, which may be explained by burial events that occurred in part of Allchar, the erosion rate estimates mostly in the range between 50 and 100 m/Ma. This range further enables us to estimate the vertical erosion rate values for the two main ore bodies Crven Dol and Centralni Deo. We also estimate that the lower and upper limits of average paleo-depths for the ore body Centralni Deo from 4.3 Ma to the present are 250ā290 and 750ā790 m, respectively, whereas the upper limit of paleo-depth for the ore body Crven Dol over the same geological age is 860 m. The estimated paleo-depth values allow estimating the relative contributions of 205Pb derived from pp-neutrino and fast cosmic-ray muons, respectively, which is an important prerequisite for the LOREX experiment
The interlaminar strength of the glass fiber polyester composite
The paper outlines the method and the results of the experimental investigation of interlaminar strength of glass fibre reinforced polyester composites, with the aim of determining the influence that the structure, a reinforcement type and a sort of resin exert upon the interlaminar strength. The tested specimens were fabricated under different formation conditions, namely in eight composition patterns and with three sorts of resin used for polymerization
Osmotic and activity coefficients of {yNa(2)So(4)+ (1-y)ZnSO4}(aq) T=298.15 K
The osmotic coefficients of the mixed electrolyte solution {y Na2SO4 + (1 - y)ZnSO4} (aq) have been measured by the isopiestic method, at T = 298.5 K. The experimental results were treated by Scatchard's, Pitzer-Kim's and Clegg-Pitzer-Brimblecombe's methods for mixed-electrolyte solutions. By these methods, the activity coefficients for Na2SO4 and ZnSO4 were calculated and compared. The Scatchard interaction parameters are used for calculation of the excess Gibbs free energy as a function of ionic strength and ionic-strength fraction of Na2SO4. Also, the Zdanovskii's rule of linearity is tested
Comparison of temporal and stride characteristics in myotonic dystrophies type 1 and 2 during dual-task walking
Objective: We analyzed temporal and stride characteristics in patients with myotonic dystrophy type 1 (DM1) and type 2 (DM2) while performing dual mental and motor tasks, and investigated correlations between gait parameters and cognitive impairments. Method: Dual-task walking was performed by 37 patients (20 DM1 and 17 DM2) and 48 healthy subjects divided into two groups, age-and gender-matched control group for DM1 (HC1) and age-and gender-matched control group for DM2 (HC2). The subjects performed a basic walking task, dual-motor task, dual-mental task, and combined motor and mental task. Results: DM1 and DM2 patients differed significantly in temporal and stride characteristics compared to HC. Main differences in DM1 were slower gait and shorter stride length, while both DM1 and DM2 patients had a higher degree of variation of the swing time during dual-task gait, a parameter that reflects posture and balance. Impact of the cognitive dual task on gait pattern changes was also observed. Visuospatial ability correlated with gait changes in DM1, while executive functions had stronger influence in DM2 (p lt 0.01). Both patient groups had leg muscle weakness. Conclusion: Gait pattern was impaired in both patient groups concerning temporal and stride characteristics. Dual-task walking paradigm may discover mild initial gait changes and could provide early identification of fall risks and predict possible falls in DM patients
On the Diversity of Semiochemicals of the Pygidial Gland Secretions of Subterranean Ground Beetles (Coleoptera: Carabidae)
Pygidial glands are of great importance to ground beetles for defense against predators, especially for the species that live in subterranean habitats. The purpose of our study is to better understand the chemistry of the pygidial gland secretions of subterranean ground beetles, as well as the function and structure of the glands. We studied both the chemical composition of the pygidial gland secretion and morphology of the glands in adults of the troglophilic ground beetle species Laemostenus (Antisphodrus) cavicola (Schaum, 1858). The chemical composition of its defensive secretion was revealed using gas chromatography-mass spectrometry (GC-MS), while pygidial gland morphology of the beetle was investigated using bright-field microcopy. In total, seven chemical compounds were detected in the secretion mixture. Formic acid was the most dominant compound, followed by dodecyl acetate and undecane. Other chemicals were present in minor amounts. The morphological structure of the pygidial glands of L. (A.) cavicola was compared with the structure of the glands of the related congeneric troglophilic species Laemostenus (Pristonychus) punctatus (Dejean, 1828). Summary data on the semiochemicals that have been recorded so far in subterranean ground beetle species are presented, and the differences in the chemical composition of the secretions between and among troglobitic and troglophilic species are discussed. So far, forty-four compounds have been detected in four subterranean ground beetle species (two troglobites belonging to the tribe Trechini and two troglophiles belonging to the tribe Sphodrini). The results of this study indicate the great diversity of chemicals in the pygidial gland secretions of subterranean ground beetles. Ā© 2023 by the authors