3,518 research outputs found
Forming peculiarities and manifestation of tectonic faults in soft rocks
Features of distribution of tectonic structures in soft rocks confirm the presence of horizontal tectonic forces in the formation of faults and are based on the manifestation of their morphological features. Linear dependences of the amplitude on the length of tectonic dislocation in the area of wedging were obtained as a result of mathematical processing of the experimental data. Actual position of the crossing lines of fault plane with the seam were considered while studying the distribution of co-fault fracturing. Analysis of the data confirms that the distribution of faulting has an undulating character. Analysis of observations showed that the deviation of the crossing line of fault plane with the seam from the middle line is subject to the normal law of random variable distribution. Thus, the studies and the obtained results allow planning mining operations assessing the utility while developing fault areas
Queue-length synchronization in a communication networks
We study synchronization in the context of network traffic on a
communication network with local clustering and geographic separations. The
network consists of nodes and randomly distributed hubs where the top five hubs
ranked according to their coefficient of betweenness centrality (CBC) are
connected by random assortative and gradient mechanisms. For multiple message
traffic, messages can trap at the high CBC hubs, and congestion can build up on
the network with long queues at the congested hubs. The queue lengths are seen
to synchronize in the congested phase. Both complete and phase synchronization
is seen, between pairs of hubs. In the decongested phase, the pairs start
clearing, and synchronization is lost. A cascading master-slave relation is
seen between the hubs, with the slower hubs (which are slow to decongest)
driving the faster ones. These are usually the hubs of high CBC. Similar
results are seen for traffic of constant density. Total synchronization between
the hubs of high CBC is also seen in the congested regime. Similar behavior is
seen for traffic on a network constructed using the Waxman random topology
generator. We also demonstrate the existence of phase synchronization in real
Internet traffic data.Comment: 13 Pages, 15 figure
Identifying Collective Modes via Impurities in the Cuprate Superconductors
We show that the pinning of collective charge and spin modes by impurities in
the cuprate superconductors leads to qualitatively different fingerprints in
the local density of states (LDOS). In particular, in a pinned (static) spin
droplet, the creation of a resonant impurity state is suppressed, the
spin-resolved LDOS exhibits a characteristic spatial pattern, and the LDOS
undergoes significant changes with increasing magnetic field. Since all of
these fingerprints are absent in a charge droplet, impurities are a new probe
for identifying the nature and relative strength of collective modes.Comment: 4 pages, 4 figure
Surveillance of Ruminant Diseases in the Nordic Countries
<p/> <p>All the Nordic countries have a basis for their surveillance and disease control in ruminants in national legislation and regulations listing notifiable diseases of concern to the countries. The Nordic countries are a disease-free zone comparing to other parts of the world and the aim of the surveillance is to keep that status and be able to document it. Following is a short summary from each country.</p
The effect of Fisher information matrix approximation methods in population optimal design calculations
Pandemic Pressure: Race, Job Insecurity, and Stress during the COVID-19 Pandemic
With the ongoing pressure of the COVID-19 pandemic, the working world has been drastically altered. Additionally, pandemic related pressures are not evenly distributed across racial groups–with negative outcomes being exacerbated as a byproduct of structural inequities for people of color (Seldan & Berdahl, 2020). Using the Perceived Stress Scale (Cohen et al., 1983), and Job Insecurity Scale (Ashford et al., 1989), we aimed to determine how various work-related factors such as job insecurity, essential worker status, and race relate to overall perceived stress in daily life. Participants (n = 266; Mage = 50.56 years, SD = 7.83; age range: 18-76 years; 49% white, 51% Black) completed a variety of measures through an online survey collected between mid-April and late May 2021. The results indicated that for white workers who identified as non-essential, and Black workers who identified as essential, increased job insecurity predicted an increase in perceived stress. The results of the study provide a launching point for identifying which demographic groups may need more support in the working world. Black essential workers and white non-essential workers likely would greatly benefit from support, resources, and interventions aiming to reduce workplace stress and improve wellbeing
Apollo Lightcraft project
The detailed design of a beam-powered transatmospheric vehicle, the Apollo Lightcraft, was selected as the project for the design course. The principal goal is to reduce the LEO payload delivery cost by at least three orders of magnitude below the Space Shuttle Orbiter in the post 2020 era. The completely reusable, single-stage-to-orbit shuttlecraft will take off and land vertically, and have a reentry heat shield integrated with its lower surface. At appropriate points along the launch trajectory, the combined cycle propulsion system will transition through three or four airbreathing modes, and finally use a pure rocket mode for orbital insertion. The objective for the Spring semester propulsion source was to design and perform a detailed theoretical analysis on an advanced combined-cycle engine suitable for the Apollo Lightcraft. The preliminary theoretical analysis of this combined-cycle engine is now completed, and the acceleration performance along representative orbital trajectories was simulated. The total round trip cost is 686 per person. This represents a payload delivery cost of $3.11/lb, which is a factor of 1000 below the STS. The Apollo Lightcraft concept is now ready for a more detailed investigation during the Fall semester Transatmosphere Vehicle Design course
Cognitive and neural plasticity in aging: General and task-specific limitations
There is evidence for cognitive as well as neural plasticity across the adult life span, although aging is associated with certain constraints on plasticity. In the current paper, we argue that the age-related reduction in cognitive plasticity may be due to (a) deficits in general processing resources, and (b) failure to engage in task-relevant cognitive operations. Memory-training research suggests that age-related processing deficits (e.g., executive functions, speed) hinder older adults from utilizing mnemonic techniques as efficiently as the young, and that this age difference is reflected by diminished frontal activity during mnemonic use. Additional constraints on memory plasticity in old age are related to difficulties that are specific to the task, such as creating visual images, as well as in binding together the information to be remembered. These deficiencies are paralleled by reduced activity in occipito-parietal and medial–temporal regions, respectively. Future attempts to optimize intervention-related gains in old age should consider targeting both general processing and task-specific origins of age-associated reductions in cognitive plasticity
- …