662 research outputs found
Teaching machines : examining and re-imagining the use of film in the classroom
This thesis investigates the use of film (both celluloid and video) in the classroom from 1920 to the present day in an effort to locate the gaps in our teaching approaches and to reinitiate dialogue among art educators regarding a unique tool for fostering cognitive and social development. Historically, films have been used as instructional aids that were relied upon to explicate everything from manners to Communism, in some cases, doing the teaching for teachers. Teaching machines were mechanical devices used for presenting a program of instructional material, ostensibly designed to lighten the teacher's load. Playing with the idea of the 'teacher-less' classroom, the installation presented here utilizes these (arguably) obsolete celluloid, slide, and filmstrip projectors to show a collection of instructional films and slides in continuous loops. In showcasing these machines and the absence of teachers, I aim to re-initiate a dialogue regarding the current lack of critical attention paid to the moving image. I believe it is imperative in an age of informal interaction with our tools of communication, that art educators consider the historical place of film in the classroom and reconsider the ways we teach with, and often underestimate film. This thesis concludes with strategies to aid our students in becoming truly critical with regards to new medi
Experimental simulation of long term weathering in alkaline bauxite residue tailings
Bauxite residue is an alkaline, saline tailings material generated as a byproduct of the Bayer process used for alumina refining. Developing effective plans for the long term management of potential environmental impacts associated with storage of these tailings is dependent on understanding how the chemical and mineralogical properties of the tailings will change during weathering and transformation into a soil-like material. Hydrothermal treatment of bauxite residue was used to compress geological weathering timescales and examine potential mineral transformations during weathering. Gibbsite was rapidly converted to boehmite; this transformation was examined with in situ synchrotron XRD. Goethite, hematite, and calcite all precipitated over longer weathering timeframes, while tricalcium aluminate dissolved. pH, total alkalinity, and salinity (electrical conductivity) all decreased during weathering despite these experiments being performed under “closed” conditions (i.e., no leaching). This indicates the potential for auto-attenuation of the high alkalinity and salinity that presents challenges for long term environmental management, and suggests that management requirements will decrease during weathering as a result of these mineral transformations
Managing hostile subsoils in the high rainfall zone of south-western Australia
This report is designed to complement existing information on the management of crops in the High Rainfall Zone of south-western Australia and to identify limitations for crop production arising from the soil properties in this area
Universal Behavior of Lyapunov Exponents in Unstable Systems
We calculate the Lyapunov exponents in a classical molecular dynamics
framework. The system is composed of few hundreds particles interacting either
through Yukawa (Nuclear) or Slater-Kirkwood (Atomic) forces. The forces are
chosen to give an Equation of State that resembles the nuclear and the atomic
Equation Of State respectively near the critical point for liquid-gas
phase transition. We find the largest fluctuations for an initial "critical
temperature". The largest Lyapunov exponents are always positive and
can be very well fitted near this "critical temperature" with a functional form
, where the exponent is
independent of the system and mass number. At smaller temperatures we find that
, a universal behavior characteristic of an order
to chaos transition.Comment: 11 pages, RevTeX, 3 figures not included available upon reques
Quantum gate algorithm for reference-guided DNA sequence alignment
Reference-guided DNA sequencing and alignment is an important process in
computational molecular biology. The amount of DNA data grows very fast, and
many new genomes are waiting to be sequenced while millions of private genomes
need to be re-sequenced. Each human genome has 3.2 B base pairs, and each one
could be stored with 2 bits of information, so one human genome would take 6.4
B bits or about 760 MB of storage (National Institute of General Medical
Sciences). Today most powerful tensor processing units cannot handle the volume
of DNA data necessitating a major leap in computing power. It is, therefore,
important to investigate the usefulness of quantum computers in genomic data
analysis, especially in DNA sequence alignment. Quantum computers are expected
to be involved in DNA sequencing, initially as parts of classical systems,
acting as quantum accelerators. The number of available qubits is increasing
annually, and future quantum computers could conduct DNA sequencing, taking the
place of classical computing systems. We present a novel quantum algorithm for
reference-guided DNA sequence alignment modeled with gate-based quantum
computing. The algorithm is scalable, can be integrated into existing classical
DNA sequencing systems and is intentionally structured to limit computational
errors. The quantum algorithm has been tested using the quantum processing
units and simulators provided by IBM Quantum, and its correctness has been
confirmed.Comment: 19 pages, 13 figure
An investigation of standard thermodynamic quantities as determined via models of nuclear multifragmentation
Both simple and sophisticated models are frequently used in an attempt to
understand how real nuclei breakup when subjected to large excitation energies,
a process known as nuclear multifragmentation. Many of these models assume
equilibriumthermodynamics and produce results often interpreted as evidence of
a phase transition. This work examines one class of models and employs standard
thermodynamical procedure to explore the possible existence and nature of a
phase transition. The role of various terms, e.g. Coulomb and surface energy,
is discussed.Comment: 19 two-column format pages with 24 figure
Event-by-Event Fluctuations in Heavy Ion Collisions and the QCD Critical Point
The event-by-event fluctuations of suitably chosen observables in heavy ion
collisions at SPS, RHIC and LHC can tell us about the thermodynamic properties
of the hadronic system at freeze-out. By studying these fluctuations as a
function of varying control parameters, it is possible to learn much about the
phase diagram of QCD. As a timely example, we stress the methods by which
present experiments at the CERN SPS can locate the second-order critical
endpoint of the first-order transition between quark-gluon plasma and hadron
matter. Those event-by-event signatures which are characteristic of freeze-out
in the vicinity of the critical point will exhibit nonmonotonic dependence on
control parameters. We focus on observables constructed from the multiplicity
and transverse momenta of charged pions. We first consider how the
event-by-event fluctuations of such observables are affected by Bose-Einstein
correlations, by resonances which decay after freeze-out and by fluctuations in
the transverse flow velocity. We compare our thermodynamic predictions for such
noncritical event-by-event fluctuations with NA49 data, finding broad
agreement. We then focus on effects due to thermal contact between the observed
pions and a heat bath with a given (possibly singular) specific heat, and due
to the direct coupling between the critical fluctuations of the sigma field and
the observed pions. We also discuss the effect of the pions produced in the
decay of sigma particles just above threshold after freeze-out on the inclusive
pion spectrum and on multiplicity fluctuations. We estimate the size of these
nonmonotonic effects which appear near the critical point, including
restrictions imposed by finite size and finite time, and conclude that they
should be easily observable.Comment: 58 pages, 2 figures; to appear in Phys. Rev.
Randomly Broken Nuclei and Disordered Systems
Similarities between models of fragmenting nuclei and disordered systems in
condensed matter suggest corresponding methods. Several theoretical models of
fragmentation investigated in this fashion show marked differences, indicating
possible new methods for distinguishing models using yield data. Applying
nuclear methods to disordered systems also yields interesting results.Comment: 10 pages, 4 figure
Studies in the statistical and thermal properties of hadronic matter under some extreme conditions
The thermal and statistical properties of hadronic matter under some extreme
conditions are investigated using an exactly solvable canonical ensemble model.
A unified model describing both the fragmentation of nuclei and the thermal
properties of hadronic matter is developed. Simple expressions are obtained for
quantities such as the hadronic equation of state, specific heat,
compressibility, entropy, and excitation energy as a function of temperature
and density. These expressions encompass the fermionic aspect of nucleons, such
as degeneracy pressure and Fermi energy at low temperatures and the ideal gas
laws at high temperatures and low density. Expressions are developed which
connect these two extremes with behavior that resembles an ideal Bose gas with
its associated Bose condensation. In the thermodynamic limit, an infinite
cluster exists below a certain critical condition in a manner similar to the
sudden appearance of the infinite cluster in percolation theory. The importance
of multiplicity fluctuations is discussed and some recent data from the EOS
collaboration on critical point behavior of nuclei can be accounted for using
simple expressions obtained from the model.Comment: 22 pages, revtex, includes 6 figures, submitted to Phys. Rev.
Contemporary presence of dynamical and statistical production of intermediate mass fragments in midperipheral Ni+Ni collisions at 30 MeV/nucleon
The reaction at 30 MeV/nucleon has been experimentally
investigated at the Superconducting Cyclotron of the INFN Laboratori Nazionali
del Sud. In midperipheral collisions the production of massive fragments
(4Z12), consistent with the statistical fragmentation of the
projectile-like residue and the dynamical formation of a neck, joining
projectile-like and target-like residues, has been observed. The fragments
coming from these different processes differ both in charge distribution and
isotopic composition. In particular it is shown that these mechanisms leading
to fragment production act contemporarily inside the same event.Comment: 9 pages, minor correction
- …