2,257 research outputs found
A preliminary examination of differential decomposition patterns in mass graves
This study represents a preliminary, quantitative approach to the examination of differential decomposition patterns in mass graves. Five pairs of mass graves, each containing the carcasses of 21 rabbits, were used to examine decomposition rates at four fixed positions within the burial. A pair of graves was exhumed at approximately 100 accumulated degree day (ADD) intervals. At exhumation the total body score (TBS) and internal carcass temperature of each rabbit were recorded. Although there was no significant difference between decomposition rates for core and deep-positioned carcasses (p = 0.13), all other position differences were significant (p < 0.001). Decomposition occurred fastest in shallow carcasses, followed by mid-outer carcasses; both deep and core carcasses exhibited a slower rate. Internal carcass temperature was significantly influenced by carcass location
within the mass grave; there was a mean internal temperature difference of ca. 1 oC between deep and
shallow carcasses (30 cm apart). Adipocere formation was minimal and confined, with the exception of a single individual in the mid- periphery, to the deepest level. Decomposition rate may be as affected by the compactness of a mass as by interment depth and/or peripheral substrate contact, and further investigation into the role of oxygenation and pH are required
A scanning drift tube apparatus for spatio-temporal mapping of electron swarms
A "scanning" drift tube apparatus, capable of mapping of the spatio-temporal
evolution of electron swarms, developing between two plane electrodes under the
effect of a homogeneous electric field, is presented. The electron swarms are
initiated by photoelectron pulses and the temporal distributions of the
electron flux are recorded while the electrode gap length (at a fixed electric
field strength) is varied. Operation of the system is tested and verified with
argon gas, the measured data are used for the evaluation of the electron bulk
drift velocity. The experimental results for the space-time maps of the
electron swarms - presented here for the first time - also allow clear
observation of deviations from hydrodynamic transport. The swarm maps are also
reproduced by particle simulations
dc readout experiment at the Caltech 40m prototype interferometer
The Laser Interferometer Gravitational Wave Observatory (LIGO) operates a 40m prototype interferometer on the Caltech campus. The primary mission of the prototype is to serve as an experimental testbed for upgrades to the LIGO interferometers and for gaining experience with advanced interferometric techniques, including detuned resonant sideband extraction (i.e. signal recycling) and dc readout (optical homodyne detection). The former technique will be employed in Advanced LIGO, and the latter in both Enhanced and Advanced LIGO. Using dc readout for gravitational wave signal extraction has several technical advantages, including reduced laser and oscillator noise couplings as well as reduced shot noise, when compared to the traditional rf readout technique (optical heterodyne detection) currently in use in large-scale ground-based interferometric gravitational wave detectors. The Caltech 40m laboratory is currently prototyping a dc readout system for a fully suspended interferometric gravitational wave detector. The system includes an optical filter cavity at the interferometer's output port, and the associated controls and optics to ensure that the filter cavity is optimally coupled to the interferometer. We present the results of measurements to characterize noise couplings in rf and dc readout using this system
Probing the Astrophysics of Cluster Outskirts
In galaxy clusters the entropy distribution of the IntraCluster Plasma
modulates the latter's equilibrium within the Dark Matter gravitational wells,
as rendered by our Supermodel. We argue the entropy production at the boundary
shocks to be reduced or terminated as the accretion rates of DM and
intergalactic gas peter out; this behavior is enforced by the slowdown in the
outskirt development at late times, when the Dark Energy dominates the
cosmology while the outer wings of the initial perturbation drive the growth.
In such conditions, we predict the ICP temperature profiles to steepen into the
cluster outskirts. The detailed expectations from our simple formalism agree
with the X-ray data concerning five clusters whose temperature profiles have
been recently measured out to the virial radius. We predict steep temperature
declines to prevail in clusters at low redshift, tempered only by rich environs
including adjacent filamentary structures.Comment: 4 pages, 3 figures, uses aa.cls. Typos corrected. Accepted by A&A
On Passion and Sports Fans:A Look at Football
The purpose of the present research was to test the applicability of the Dualistic Model of Passion (Vallerand et al., 2003) to being a sport (football) fan. The model posits that passion is a strong inclination toward an activity that individuals like (or even love), that they value, and in which they invest time and energy. Furthermore, two types of passion are proposed: harmonious and obsessive passion. While obsessive passion entails an uncontrollable urge to engage in the passionate activity, harmonious passion entails a sense of volition while engaging in the activity. Finally, the model posits that harmonious passion leads to more adaptive outcomes than obsessive passion. Three studies provided support for this dualistic conceptualization of passion. Study 1 showed that harmonious passion was positively associated with adaptive behaviours (e.g., celebrate the team’s victory), while obsessive passion was rather positively associated with maladaptive behaviours (e.g., to risk losing one’s employment to go to the team’s game). Study 2 used a short Passion Scale and showed that harmonious passion was positively related to the positive affective life of fans during the 2006 FIFA World Cup, psychological health (self-esteem and life satisfaction), and public displays of adaptive behaviours (e.g., celebrating one’s team victory in the streets), while obsessive passion was predictive of maladaptive affective life (e.g., hating opposing team’s fans) and behaviours (e.g., mocking the opposing team’s fans). Finally, Study 3 examined the role of obsessive passion as a predictor of partner’s conflict that in turn undermined partner’s relationship satisfaction. Overall, the present results provided support for the Dualistic Model of Passion. The conceptual and applied implications of the findings are discussed
Phase-space structures II: Hierarchical Structure Finder
A new multi-dimensional Hierarchical Structure Finder (HSF) to study the
phase-space structure of dark matter in N-body cosmological simulations is
presented. The algorithm depends mainly on two parameters, which control the
level of connectivity of the detected structures and their significance
compared to Poisson noise. By working in 6D phase-space, where contrasts are
much more pronounced than in 3D position space, our HSF algorithm is capable of
detecting subhaloes including their tidal tails, and can recognise other
phase-space structures such as pure streams and candidate caustics. If an
additional unbinding criterion is added, the algorithm can be used as a
self-consistent halo and subhalo finder. As a test, we apply it to a large halo
of the Millennium Simulation, where 19 % of the halo mass are found to belong
to bound substructures, which is more than what is detected with conventional
3D substructure finders, and an additional 23-36 % of the total mass belongs to
unbound HSF structures. The distribution of identified phase-space density
peaks is clearly bimodal: high peaks are dominated by the bound structures and
low peaks belong mostly to tidal streams. In order to better understand what
HSF provides, we examine the time evolution of structures, based on the merger
tree history. Bound structures typically make only up to 6 orbits inside the
main halo. Still, HSF can identify at the present time at least 80 % of the
original content of structures with a redshift of infall as high as z <= 0.3,
which illustrates the significant power of this tool to perform dynamical
analyses in phase-space.Comment: Submitted to MNRAS, 24 pages, 18 figure
Summary of the 3rd ENER Forum: How to promote renewable energy systems successfully and effectively
Control sideband generation for dual-recycled laser interferometric gravitational wave detectors
We present a discussion of the problems associated with generation of multiple control sidebands for length sensing and control of dual-recycled, cavity-enhanced Michelson interferometers and the motivation behind more complicated sideband generation methods. We focus on the Mach–Zehnder interferometer as a topological solution to the problem and present results from tests carried out at the Caltech 40 m prototype gravitational wave detector. The consequences for sensing and control for advanced interferometry are discussed, as are the implications for future interferometers such as Advanced LIGO
A Feasibility Study for the Automated Monitoring and Control of Mine Water Discharges
The chemical treatment of mine-influenced waters is a longstanding environmental challenge for many coal operators, particularly in Central Appalachia. Mining conditions in this region present several unique obstacles to meeting NPDES effluent limits. Outlets that discharge effluent are often located in remote areas with challenging terrain where conditions do not facilitate the implementation of large-scale commercial treatment systems. Furthermore, maintenance of these systems is often laborious, expensive, and time consuming. Many large mining complexes discharge water from numerous outlets, while using environmental technicians to assess the water quality and treatment process multiple times per day. Unfortunately, this treatment method when combined with the lower limits associated with increased regulatory scrutiny can lead to the discharge of non-compliant water off of the mine permit. As an alternative solution, this thesis describes the ongoing research and development of automated protocols for the treatment and monitoring of mine water discharges. In particular, the current work highlights machine learning algorithms as a potential solution for pH control.;In this research, a bench-scale treatment system was constructed. This system simulates a series of ponds such as those found in use by Central Appalachian coal companies to treat acid mine drainage. The bench-scale system was first characterized to determine the volumetric flow rates and resident time distributions at varying flow rates and reactor configurations. Next, data collection was conducted using the bench scale system to generate training data by introducing multilevel random perturbations to the alkaline and acidic water flow rates. A fuzzy controller was then implemented in this system to administer alkaline material with the goal of automating the chemical treatment process. Finally, the performance of machine learning algorithms in predicting future water quality was evaluated to identify the critical input variables required to build these algorithms. Results indicate the machine learning controllers are viable alternatives to the manual control used by many Appalachian coal producers
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