752 research outputs found
Bringing the Entrepreneurial Mindset into Mining Engineering Education
There has been an ongoing debate on how to transform engineering education to better prepare students for today`s professional world that is characterized by increasingly complex problems and challenges that engineers are tasked with upon entering the industry. Within the conceive–design–implement–operate (CDIO) framework, entrepreneurship education presents a valuable pedagogical approach to foster the necessary skills of the students through integrated, hands-on, active learning experiences. While numerous publications have addressed possibilities of how experiential, problem-based, project-based and active learning can be integrated into engineering curriculum, there has been hardly any attention on mining engineering with respect to adopting this approach. This paper will address the possibilities of integrating entrepreneurship education into mining engineering programs in particular. This paper will enhance and foster discussion among academics from mining engineering on how to integrate elements of entrepreneurship education on a course, program and departmental level to infuse value creation experiences across the curriculum
Optical Properties of Deep Ice at the South Pole - Absorption
We discuss recent measurements of the wavelength-dependent absorption
coefficients in deep South Pole ice. The method uses transit time distributions
of pulses from a variable-frequency laser sent between emitters and receivers
embedded in the ice. At depths of 800 to 1000 m scattering is dominated by
residual air bubbles, whereas absorption occurs both in ice itself and in
insoluble impurities. The absorption coefficient increases approximately
exponentially with wavelength in the measured interval 410 to 610 nm. At the
shortest wavelength our value is about a factor 20 below previous values
obtained for laboratory ice and lake ice; with increasing wavelength the
discrepancy with previous measurements decreases. At around 415 to 500 nm the
experimental uncertainties are small enough for us to resolve an extrinsic
contribution to absorption in ice: submicron dust particles contribute by an
amount that increases with depth and corresponds well with the expected
increase seen near the Last Glacial Maximum in Vostok and Dome C ice cores. The
laser pulse method allows remote mapping of gross structure in dust
concentration as a function of depth in glacial ice.Comment: 26 pages, LaTex, Accepted for publication in Applied Optics. 9
figures, not included, available on request from [email protected]
Diversity of habitats and bacterial communities support landscape-scale multifunctionality differently across seasons
Abstract In this study, we demonstrate how changes in the diversity of habitat and bacterial communities affect landscape multifunctionality. Habitat diversity may beget species diversity by increasing niche availability and resource complementarity. Species diversity, in turn, generally promotes multifunctionality, i.e. the simultaneous performance of multiple ecosystem functions. However, the relationship between habitat diversity and functioning remains to be explicitly explored. In order to test the relationship between habitat diversity and multifunctionality we constructed experimental landscapes of four different habitats common in shallow-water sediment ecosystems: cyanobacterial mats, Ruppia maritima meadows, silty mud and sandy beach. We manipulated the diversity of these habitats over three consecutive seasons and measured bacterial diversity, benthic microalgal diversity and four functions related to marine nitrogen cycling (gross primary production, nitrogen fixation, denitrification and uptake of dissolved inorganic nitrogen). Our results showed that higher habitat and bacterial diversity, but not benthic microalgal diversity, increased landscape multifunctionality. However, the relative importance of habitat and bacterial diversity varied with season. Habitat diversity was generally the strongest driver, affecting multifunctionality directly in summer and indirectly via bacterial diversity in autumn. In spring, neither of the two aspects of diversity was important. Our study demonstrates the importance of considering temporal differences in both habitat and species diversity for landscape multifunctionality, and the importance of direct and indirect effects in mediating ecosystem functions. Habitat homogenization in concert with loss in biodiversity can thus be a driving force of declining ecosystem functioning and the services they underpin
Quark--antiquark states and their radiative transitions in terms of the spectral integral equation. {\Huge II.} Charmonia
In the precedent paper of the authors (hep-ph/0510410), the states
were treated in the framework of the spectral integral equation, together with
simultaneous calculations of radiative decays of the considered bottomonia. In
the present paper, such a study is carried out for the charmonium
states. We reconstruct the interaction in the -sector on the basis of
data for the charmonium levels with , , ,
, , and radiative transitions
, , ,
and , ,
. The levels and their wave functions
are calculated for the radial excitations with . Also, we determine the
component of the photon wave function using the annihilation
data: , , , , , and perform the calculations of the partial widths of
the two-photon decays for the states: , ,
, and states:
, , . We discuss the status of the recently observed states
X(3872) and Y(3941): according to our results, the X(3872) can be either
or , while Y(3941) is .Comment: 24 pages, 9 figure
Quark--antiquark states and their radiative transitions in terms of the spectral integral equation. {\Huge III.} Light mesons
We continue the investigation of mesons in terms of the spectral integral
equation initiated before [hep-ph/0510410, hep-ph/0511005] for the
and systems: in this paper we consider the light-quark ()
mesons with masses GeV. The calculations have been performed for the
mesons lying on linear trajectories in the -planes, where is the
radial quantum number. Our consideration relates to the states with
one component in the flavor space, with the quark and antiquark masses equal to
each other, such as , , ,
, , , , ,
, , , ,
, at . We obtained the wave functions
and mass values of mesons lying on these trajectories. The corresponding
trajectories are linear, in agreement with data. We have calculated the
two-photon decays , ,
, , and radiative transitions ,
, that agree qualitatively with the experiment. On this
basis, we extract the singular part of the interaction amplitude, which
corresponds to the so-called "confinement interaction". The description of the
data requires the presence of the strong -channel singularities for both
scalar and vector exchanges.Comment: 48 pages, 24 figure
Charmed quark component of the photon wave function
We determine the c-anti-c component of the photon wave function on the basis
of (i) the data on the transitions e+ e- -> J/psi(3096), psi(3686), psi(4040),
psi(4415), (ii) partial widths of the two-photon decays eta_{c0}(2979),
chi_{c0}(3415), chi_{c2}(3556) -> gamma-gamma, and (iii) wave functions of the
charmonium states obtained by solving the Bethe-Salpeter equation for the
c-anti-c system. Using the obtained c-anti-c component of the photon wave
function we calculate the gamma-gamma decay partial widths for radial
excitation 2S state, eta_{c0}(3594) -> gamma-gamma, and 2P states
chi_{c0}(3849), chi_{c2}(3950) -> gamma-gamma.Comment: 20 pages, 8 figure
The AMANDA Neutrino Telescope and the Indirect Search for Dark Matter
With an effective telescope area of order 10^4 m^2, a threshold of ~50 GeV
and a pointing accuracy of 2.5 degrees, the AMANDA detector represents the
first of a new generation of high energy neutrino telescopes, reaching a scale
envisaged over 25 years ago. We describe its performance, focussing on the
capability to detect halo dark matter particles via their annihilation into
neutrinos.Comment: Latex2.09, 16 pages, uses epsf.sty to place 15 postscript figures.
Talk presented at the 3rd International Symposium on Sources and Detection of
Dark Matter in the Universe (DM98), Santa Monica, California, Feb. 199
Inheritance patterns in citation networks reveal scientific memes
Memes are the cultural equivalent of genes that spread across human culture
by means of imitation. What makes a meme and what distinguishes it from other
forms of information, however, is still poorly understood. Our analysis of
memes in the scientific literature reveals that they are governed by a
surprisingly simple relationship between frequency of occurrence and the degree
to which they propagate along the citation graph. We propose a simple
formalization of this pattern and we validate it with data from close to 50
million publication records from the Web of Science, PubMed Central, and the
American Physical Society. Evaluations relying on human annotators, citation
network randomizations, and comparisons with several alternative approaches
confirm that our formula is accurate and effective, without a dependence on
linguistic or ontological knowledge and without the application of arbitrary
thresholds or filters.Comment: 8 two-column pages, 5 figures; accepted for publication in Physical
Review
The AMANDA Neutrino Telescope: Principle of Operation and First Results
AMANDA is a high-energy neutrino telescope presently under construction at
the geographical South Pole. In the Antarctic summer 1995/96, an array of 80
optical modules (OMs) arranged on 4 strings (AMANDA-B4) was deployed at depths
between 1.5 and 2 km. In this paper we describe the design and performance of
the AMANDA-B4 prototype, based on data collected between February and November
1996. Monte Carlo simulations of the detector response to down-going
atmospheric muon tracks show that the global behavior of the detector is
understood. We describe the data analysis method and present first results on
atmospheric muon reconstruction and separation of neutrino candidates. The
AMANDA array was upgraded with 216 OMs on 6 new strings in 1996/97
(AMANDA-B10), and 122 additional OMs on 3 strings in 1997/98.Comment: 36 pages, 23 figures, submitted to Astroparticle Physic
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