694 research outputs found
RAST, SMRTNOST I PRODUKCIJA POTOČNE PASTRVE I DUŽIČASTE PASTRVE U VODOTOCIMA DRŽAVE NEW MEXICO
Thirty-two representative trout sites in 15 high elevation New Mexico streams (1,661 - 2560 m above sea level) were sampled in 1988 and 1989. Fish was captured by consecutive removal via electrofishing in net-blocked segments from 65 to 160 m long. Maximum estimated trout length (Lm.ax) was related inversely to yield (r2 = 0.351; p = 0.055). Instantaneous rate of mortality was also marginally related to yield (r2 = 0.294). The production index ranged from 1,38 to 32.02 g/m2/year. Variation in production was highly correlated to trout biomass (r2 = 0.910). Trout growth and production were best defined by the relationships where: cover, stream width, water temperature, yield by anglers, LMAX, and nitrate-nitrogen concentration were included.Tijekom godina 1988. I 1989. uzorkovanje riba provedeno je na 32 reprezentativne postaje smještene na 15 visokoplaninskih vodotoka (nadmorska visina 1.661 do 2.560 m). Pastrve su lovljene uzastopnim izlovima elektroagregatom unutar mrežama blokiranih segmenata u dužini od 65 do 160 m. Maksimalno procijenjena dužina pastrva (LMAX) bila je u negativnom odnosu prema ulovu (r2 = 0,351; p = 0,055). Marginalna pozitivna veza dokazana je između trenutačne stope smrtnosti i sportskog ribolova (r2 = 0,294). Indeks produkcije procijenjen je između 1,38 i 31,02 g/m2/godinu. Promjene u produkciji u najvećoj mjeri ovise o biomasi pastrva (r2 = 0,910). Prirast i produkcija najbolje su objašnjeni višestrukom regresijskom analizom sa slijedećim atributima sredine: sklonište, širina vodotoka, temperatura vode, sportski ribolov, LMAX, i koncentracija spojeva dušika
The Whole Heliosphere Interval in the Context of a Long and Structured Solar Minimum: An Overview from Sun to Earth
Throughout months of extremely low solar activity during the recent extended solar-cycle minimum, structural evolution continued to be observed from the Sun through the solar wind and to the Earth. In 2008, the presence of long-lived and large low-latitude coronal holes meant that geospace was periodically impacted by high-speed streams, even though solar irradiance, activity, and interplanetary magnetic fields had reached levels as low as, or lower than, observed in past minima. This time period, which includes the first Whole Heliosphere Interval (WHI 1: Carrington Rotation (CR) 2068), illustrates the effects of fast solar-wind streams on the Earth in an otherwise quiet heliosphere. By the end of 2008, sunspots and solar irradiance had reached their lowest levels for this minimum (e.g., WHI 2: CR 2078), and continued solar magnetic-flux evolution had led to a flattening of the heliospheric current sheet and the decay of the low-latitude coronal holes and associated Earth-intersecting high-speed solar-wind streams. As the new solar cycle slowly began, solar-wind and geospace observables stayed low or continued to decline, reaching very low levels by June – July 2009. At this point (e.g., WHI 3: CR 2085) the Sun–Earth system, taken as a whole, was at its quietest. In this article we present an overview of observations that span the period 2008 – 2009, with highlighted discussion of CRs 2068, 2078, and 2085. We show side-by-side observables from the Sun’s interior through its surface and atmosphere, through the solar wind and heliosphere and to the Earth’s space environment and upper atmosphere, and reference detailed studies of these various regimes within this topical issue and elsewhere
Magnetic excitations of the Cu quantum spin chain in SrCuPtO
We report the magnetic excitation spectrum as measured by inelastic neutron
scattering for a polycrystalline sample of SrCuPtO. Modeling the data
by the 2+4 spinon contributions to the dynamical susceptibility within the
chains, and with interchain coupling treated in the random phase approximation,
accounts for the major features of the powder-averaged structure factor. The
magnetic excitations broaden considerably as temperature is raised, persisting
up to above 100 K and displaying a broad transition as previously seen in the
susceptibility data. No spin gap is observed in the dispersive spin excitations
at low momentum transfer, which is consistent with the gapless spinon continuum
expected from the coordinate Bethe ansatz. However, the temperature dependence
of the excitation spectrum gives evidence of some very weak interchain
coupling.Comment: 9 pages, 5 figure
Correlation between bulk thermodynamic measurements and the low temperature resistance plateau in SmB6
Topological insulators are materials characterized by dissipationless,
spin-polarized surface states resulting from non-trivial band topologies.
Recent theoretical models and experiments suggest that SmB6 is the first
topological Kondo insulator, in which the topologically non-trivial band
structure results from electron-electron interactions via Kondo hybridization.
Here, we report that the surface conductivity of SmB6 increases systematically
with bulk carbon content. Further, addition of carbon is linked to an increase
in n-type carriers, larger low temperature electronic contributions to the
specific heat with a characteristic temperature scale of T* = 17 K, and a
broadening of the crossover to the insulating state. Additionally, X-ray
absorption spectroscopy shows a change in Sm valence at the surface. Our
results highlight the importance of phonon dynamics in producing a Kondo
insulating state and demonstrate a correlation between the bulk thermodynamic
state and low temperature resistance of SmB6
Real-time measurement and analysis of audience response
© ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2020. How do you harness a “level” of emotional connectivity from audience/participants? Questionnaires, focus group discussions, interviews and other qualitative methods gather retrospective thoughts of the participant and may miss important insights or connections that could be discovered if a real-time response is recorded. The aspiration for real-time audience data recording is problematic in many areas of research, in particular performing arts where the work/research presented is time bound. In addressing this problem within research into the design of novel musical controllers, custom “sliders” were used to measure and examine real-time audience response to short musical performances. The audience moved their sliders in response to the performance, producing continuous data that was recorded into music software and timestamped. The initial test results have shown promising insights and usefulness for real-time data collection and examination. These results and possible methods of data analysis are presented along with discussion on how this approach may be applied in other research contexts
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