129 research outputs found
Ruthenium Oxidation in High Temperature Air and Release of Gaseous Ruthenium KFKI-3/2008
The RUSET experimental programme was launched in order to study Ru oxidation and
release from fuel in high temperature air. More than forty small scale tests have been
performed with mixed powder components of inactive materials and with short fuel rods.
The influence of temperature, air flow rate and the presence of other fission products on the
gaseous Ru release and the retention role of fuel pellets and cladding have been
investigated. The test series indicated that if an air ingress type severe accident occurs most
of the initial Ru mass can be released from the reactor core to the containment or
environment. Some part of the released gaseous Ru undergoes precipitation and deposits on
the cold surfaces, another part is released in gaseous form. The deposited Ru oxides can
serve as a secondary source for further gaseous Ru releas
CODEX-B4C Experiment: Cored Degradation Test With Boron Carbide Control Rod KFKI-2003-01/G (2003)
The CODEX-B4C bundle test has been successfully performed on 25th May 2001 in the
framework of the COLOSS project of the EU 5th FWP. The high temperature degradation
of a VVER-1000 type bundle with B4C control rod was investigated with electrically
heated fuel rods. The experiment was carried out according to a scenario selected in
favour of methane formation. Degradation of control rod and fuel bundle took place at
temperatures ~2000 oC, cooling down of the bundle was performed in steam atmosphere.
The gas composition measurement indicated no methane production during the
experiment. High release of aerosols was detected in the high temperature oxidation
phase. The on-line measured data are collected into a database and are available for code
validation and development
Change of composition and diversity of species and grassland management between different grazing intensity in Pannonian dry and wet grasslands
Investigations were carried out in wet and dry pasture. Coenological recordings were taken in
three zones. The first zone (“A”) located 0-50 m near the stable, second zone (“B”) located 50-150 m
from the stable, while the third zone (“C”) located farther than 150 m. We have carried out analyses of
ecological and environmental factors and life form types. Based on our results for both dry and wet
grasslands, quadrates of “A” zone were well isolated from the rest of the zones. Overgrazing, which
involves considerable trampling, vanishes differences among vegetations, thereby promotes weed and
disturbance tolerant rich vegetation. The lowest species number and diversity could be found here. Due to
the nitrogen enrichment due to the constant presence of livestock, drier and less heat demanding habitat
developed in the “A” zones, according to the environmental indicators. Because of the change in
management, conservation and diversity values of “C” zone increased, however, according to nature
protection values it underperformed compared to “B” zone. According to the sample area, wet grasslands
from the sandy areas of Kiskunság, preserve nature protection values and grass composition better
moving away from stables, due to less grazing pressure. Drier backgrounds tolerate stronger grazing
pressure
Development of a large-scale pathogen screening test for the biosafety evaluation of canine mesenchymal stem cells
Background
The action of mesenchymal stem cells (MSCs) is the subject of intense research in the field of regenerative medicine, including their potential use in companion animals, such as dogs. To ensure the safety of canine MSC batches for their application in regenerative medicine, a quality control test must be conducted in accordance with Good Manufacturing Practices (GMP). Based on guidance provided by the European Medicines Agency, this study aimed to develop and validate a highly sensitive and robust, nucleic acid-based test panel for the detection of various canine pathogens. Analytical sensitivity, specificity, amplification efficiency, and linearity were evaluated to ensure robust assessment. Additionally, viable spike-in controls were used to control for optimal nucleic acid extraction. The conventional PCR-based and real-time PCR-based pathogen assays were evaluated in a real-life setting, by direct testing MSC batches.
Results
The established nucleic acid-based assays displayed remarkable sensitivity, detecting 100–1 copies/reaction of template DNA. They also exhibited high specificity and efficiency. Moreover, highly effective nucleic acid isolation was confirmed by the sensitive detection of spike-in controls. The detection capacity of our optimized and validated methods was determined by direct pathogen testing of nine MSC batches that displayed unusual phenotypes, such as reduced cell division or other deviating characteristics. Among these MCS batches of uncertain purity, only one tested negative for all pathogens. The direct testing of these samples yielded positive results for important canine pathogens, including tick-borne disease-associated species and viral members of the canine infectious respiratory disease complex (CIRDC). Notably, samples positive for the etiological agents responsible for enteritis (CPV), leptospirosis (Leptospira interrogans), and neosporosis (Neospora caninum) were also identified. Furthermore, we conducted biosafety evaluation of 12 MSC batches intended for therapeutic application. Eleven MSC batches were found to be free of extraneous agents, and only one tested positive for a specific pathogen, namely, canine parvovirus.
Conclusion
In this study, we established and validated reliable, highly sensitive, and accurate nucleic acid-based testing methods for a broad spectrum of canine pathogens
Measurement of the mass difference and the binding energy of the hypertriton and antihypertriton
According to the CPT theorem, which states that the combined operation of
charge conjugation, parity transformation and time reversal must be conserved,
particles and their antiparticles should have the same mass and lifetime but
opposite charge and magnetic moment. Here, we test CPT symmetry in a nucleus
containing a strange quark, more specifically in the hypertriton. This
hypernucleus is the lightest one yet discovered and consists of a proton, a
neutron, and a hyperon. With data recorded by the STAR
detector{\cite{TPC,HFT,TOF}} at the Relativistic Heavy Ion Collider, we measure
the hyperon binding energy for the hypertriton, and
find that it differs from the widely used value{\cite{B_1973}} and from
predictions{\cite{2019_weak, 1995_weak, 2002_weak, 2014_weak}}, where the
hypertriton is treated as a weakly bound system. Our results place stringent
constraints on the hyperon-nucleon interaction{\cite{Hammer2002,
STAR-antiH3L}}, and have implications for understanding neutron star interiors,
where strange matter may be present{\cite{Chatterjee2016}}. A precise
comparison of the masses of the hypertriton and the antihypertriton allows us
to test CPT symmetry in a nucleus with strangeness for the first time, and we
observe no deviation from the expected exact symmetry
On the selection of subdivision directions in interval branch-and-bound methods for global optimization
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