38 research outputs found
Silver-palladium braze alloy recovered from masking materials
Method for recovering powdered silver-palladium braze alloy from an acrylic spray binder and rubber masking adhesive used in spray brazing is devised. The process involves agitation and dissolution of masking materials and recovery of suspended precious metal particles on a filter
Thermodynamics of quark matter with multiquark clusters in an effective Beth-Uhlenbeck type approach
We describe multiquark clusters in quark matter within a Beth-Uhlenbeck
approach in a background gluon field coupled to the underlying chiral quark
dynamics using the Polyakov gauge which establishes the center symmetry of
color SU(3) that suppresses colored states as an aspect of confinement. Quark
confinement is modeled by a large quark mass in vacuum motivated by a confining
density functional approach. A multiquark cluster containing quarks and
antiquarks is described as a binary composite of smaller subclusters and
(). It has a spectrum consisting of a bound state and a
scattering state continuum. For the corresponding cluster-cluster phase shifts
we discuss simple ans\"atze that capture the Mott dissociation of clusters as a
function of temperature and chemical potential. We go beyond the simple
"step-up-step-down" model that ignores continuum correlations and introduce an
improved model that includes them in a generic form. In order to explain the
model, we restrict ourselves here to the cases where the cluster size is . A striking result is the suppression of the abundance of colored
multiquark clusters at low temperatures by the coupling to the Polyakov loop
and their importance for a quantitative description of lattice QCD
thermodynamics at non-vanishing baryochemical potentials. An important
ingredient are Polyakov-loop generalized distribution functions of -quark
clusters which are derived here for the first time. Within our approach we
calculate thermodynamic properties such as baryon density and entropy. We
demonstrate that the limits of a hadron resonance gas at low temperatures and
perturbative QCD at high temperatures are correctly
reproduced. A comparison with lattice calculations shows that our model is able
to give a unified, systematic approach to describe properties of the
quark-gluon-hadron system.Comment: 20 pages, 11 figures, 6 table
The Evolution of Cognitive Load Theory and the Measurement of Its Intrinsic, Extraneous and Germane Loads: A Review
Cognitive Load Theory has been conceived for supporting instructional design through the use of the construct of cognitive load. This is believed to be built upon three types of load: intrinsic, extraneous and germane. Although Cognitive Load Theory and its assumptions are clear and well-known, its three types of load have been going through a continuous investigation and re-definition. Additionally, it is still not clear whether these are independent and can be added to each other towards an overall measure of load. The purpose of this research is to inform the reader about the theoretical evolution of Cognitive Load Theory as well as the measurement techniques and measures emerged for its cognitive load types. It also synthesises the main critiques of scholars and the scientific value of the theory from a rationalist and structuralist perspective
The protective ability of the Mediterranean plant extracts against the oxidative DNA damage. The role of the radical oxygen species and the polyphenol content.
The polyphenol plant extracts content seems to be responsible for the scavenging activity of the reactive oxygen species (ROS), resulting in protection against DNA damage induced by the oxidative stress. This assumption was verified analyzing the effect of six Mediterranean plant extracts (Crepis vesicaria L, Origanum heracleoticum, Scandix australis L, Amaranthus sp., Scolymus hispanicus L, Thymus piperella L) on the oxidative DNA damage induced in lymphocytes by H 2O 2 in relation to the polyphenolic content and the lymphocyte scavenging ability of ROS. The comet assay was used to evaluate oxidative DNA damage and the polyphenol content was analyzed by the Folin-Ciocalteu method. The fluorescence resulting from oxidation of ROS-sensitive dye, dihydrorofluorescein (DHF), was utilized as indicator of the ROS level. Pretreatment with all plant extracts produced the dose-dependent increase in the DNA protection up to the 0.2 \u3bcg/ml polyphenol content and the decrease above that dose. Only the Thymus piperella, similarly to quercetin, showed a strong positive correlation between the DNA protection and the polyphenol content, but negative correlation with ROS formation. In conclusion, the DNA protective ability of plant extracts seems to be related to the low polyphenol concentration and only to certain extent depends on the polyphenol ROS scavenging activity
Co-Circulation of Different Hepatitis E Virus Genotype 3 Subtypes in Pigs and Wild Boar in North-East Germany, 2019
Hepatitis E is a major cause of acute liver disease in humans worldwide. The infection is caused by hepatitis E virus (HEV) which is transmitted in Europe to humans primarily through zoonotic foodborne transmission from domestic pigs, wild boar, rabbits, and deer. HEV belongs to the family Hepeviridae, and possesses a positive-sense, single stranded RNA genome. This agent usually causes an acute self-limited infection in humans, but in people with low immunity, e.g., immunosuppressive therapy or underlying liver diseases, the infection can evolve to chronicity and is able to induce a variety of extrahepatic manifestations. Pig and wild boar have been identified as the primary animal reservoir in Europe, and consumption of raw and undercooked pork is known to pose a potential risk of foodborne HEV infection. In this study, we analysed pig and wild boar liver, faeces, and muscle samples collected in 2019 in Mecklenburg-Western Pomerania, north-east Germany. A total of 393 animals of both species were investigated using quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR), conventional nested RT-PCR and sequence analysis of amplification products. In 33 animals, HEV RNA was detected in liver and/or faeces. In one individual, viral RNA was detected in muscle tissue. Sequence analysis of a partial open reading frame 1 region demonstrated a broad variety of genotype 3 (HEV-3) subtypes. In conclusion, the study demonstrates a high, but varying prevalence of HEV RNA in swine populations in Mecklenburg-Western Pomerania. The associated risk of foodborne HEV infection needs the establishment of sustainable surveillance and treatment strategies at the interface between humans, animals, and the environment within a One Health framework
A Putative Novel Hepatitis E Virus Genotype 3 Subtype Identified in Rabbit, Germany 2016
Hepatitis E is an emerging viral disease that is the leading cause of viral hepatitis in the world. The vast majority of hepatitis E cases in developed countries are caused by zoonotic genotypes 3 and 4 of hepatitis E virus (HEV) for which pig and wild boar and to lesser extent rabbits are the main reservoir. According to recent reports rabbits are a source of human HEV infection and highlight the risk of zoonotic foodborne transmission. Here we report the molecular analysis of a novel HEV strain identified in a rabbit during a countrywide surveillance of rabbits and hares in Germany, 2016. The analysis of the complete genome reveals characteristics of a putative novel recombinant subtype of the species Orthohepevirus A within the clade of genotype 3 but not closely related to any known subtypes. Importantly, the genome of this strain possesses a nucleotide exchange in the overlapping region of open reading frames ORF2/ORF3 interfering with a broadly applied diagnostic real-time RT-PCR. In conclusion, a new type of HEV strain was identified in a German rabbit with atypical and novel sequence characteristics
Cognitive Load Based Adaptive Assistive Technology Design for Reconfigured Mobile Android Phone
In assistive technology design, it is indispensible to consider the sensory, physical and cognitive level of target users. Cognitive load is an important indicator of cognitive feedback during interaction and became the critical research issue in designing assistive user interfaces, incorporated with smartphone based assistive technology like in the android platform. In this paper, we proposed a cognitive load based user interface integrated with reconfigured mobile android phone (R-MAP) based on user\u27s cognitive load level. We performed some cognitive tasks within a small group of sighted but blindfolded people and blind people or visually impaired using R-MAP. Based on task performance and cognitive load levels we manually annotated some data of 24 participants and finally applied some machine learning algorithms to automate the mobile interface. Based on our novel design and experimental finding, we recommended that cognitive load enabled feedbacks based assistive user interface would be a useful assistive tool for the people who use mobile phone for their daily operations. © 2012 ICST Institute for Computer Science, Social Informatics and Telecommunications Engineering