6,456 research outputs found
Hydro-mechanical analysis of low enriched uranium fuel plates for University of Missouri Research Reactor
Title from PDF of title page (University of Missouri--Columbia, viewed on September 12, 2012).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Thesis advisor: Dr. Gary L. SolbrekkenIncludes bibliographical references.M. S. University of Missouri--Columbia 2012."May 2012"As part of the Global Threat Reduction Initiative (GTRI) Reactor Conversion program, work is underway to analyze and validate a new fuel assembly for the University of Missouri Research Reactor (MURR). The Low Enriched Uranium (LEU) design currently under investigation is a significant departure from the current High Enriched Uranium (HEU) design. Changes in the fuel design include a significant thinning of the fuel plates, as well as a change to a monolithic foil based fuel. These changes increase the potential for coolant flow induced deflection of the fuel plates which could lead to fuel plate failure. With the continued advancement of computational codes, new options are emerging to assess structural stability. This research explores using explicitly coupled fluid-structure interaction (FSI) numeric modeling. Work was completed to evaluate a method for coupling a computational fluid dynamics (CFD) code with a finite element analysis (FEA) code. Additionally, research was completed on methods to improve the stability and efficiency of coupled simulations. This research has successfully provided a way to analyze the complex interactions of fluid and structural systems. These techniques will be invaluable in evaluating the proposed LEU fuel plate structure for MURR
Fast-field cycling NMR is sensitive to the method of cross-linking in BSA gels
This work was supported by ARUK (grant number 19689).Non peer reviewedPublisher PD
Herschel Observations of Debris Discs Orbiting Planet-hosting Subgiants
Debris discs are commonly detected orbiting main-sequence stars, yet little
is known regarding their fate as the star evolves to become a giant. Recent
observations of radial velocity detected planets orbiting giant stars highlight
this population and its importance for probing, for example, the population of
planetary systems orbiting intermediate mass stars. Our Herschel survey
observed a subset of the Johnson et al program subgiants, finding that 4/36
exhibit excess emission thought to indicate debris, of which 3/19 are
planet-hosting stars and 1/17 are stars with no current planet detections.
Given the small numbers involved, there is no evidence that the disc detection
rate around stars with planets is different to that around stars without
planets. Our detections provide a clear indication that large quantities of
dusty material can survive the stars' main-sequence lifetime and be detected on
the subgiant branch, with important implications for the evolution of planetary
systems and observations of polluted or dusty white dwarfs. Our detection rates
also provide an important constraint that can be included in models of debris
disc evolution.Comment: 12 pages, MNRAS, accepte
Twisted [(R3P)PdX] groups above dicarbaborane ligands: 4-dimethylsulfido-3-iodo-3-triphenylphosphine-closo-3-pallada-1,2-dicarbadodecaborane and 3-dimethylphenylphosphine-3-chloro-4-dimethylsulfido-closo-3-pallada-1,2-dicarbadodecaborane
The structural analyses of [3-(PPh₃)-3-I-4-(SMe₂)-closo-3,1,2-PdC₂B₉H₁₀] or [Pd(C₄H₁₆B₉S)I(C₁₈H₁₅P)], (I), and [3-(PPhMe₂)-3-Cl-4-(SMe₂)-closo-3,1,2-PdC₂B₉H₁₀] or [Pd(C₄H₁₆B₉S)Cl(C₈H₁₁P)], (II), show that in comparison with [3-(PR₃)2-closo-3,1,2-PdC₂B₉H₁₁] the presence of the 4-SMe₂ group causes the [PdX(PR₃)] unit (X = halogen) to twist about an axis passing through the Pd atom and the directly opposite B atom of the carbaborane ligand. The halogen atoms are located almost directly above a C atom in the C₂B₃ face, and the conformations of the [PdX(PR₃)] units above the C₂B₃ faces are not those predicted from molecular orbital calculations of the closo-3,1,2-PdC₂B₉ system. The fact that the variation from the predicted conformation is greater in the case of (I) than in (II) may be ascribed to the greater steric interactions induced by the I atom in (I) compared with the Cl atom in (II)
The relation between the frequency distributions of sieve diameters and fall velocities of sediment particles
A relation between the frequency distributions of sieve diameters and fall velocities is developed. The relation shows that if the sieve diameters of a sediment are log-normally distributed, the fall velocities will also have this distribution, but with a different standard deviation which can be calculated. The results of detailed measurements of the fall velocities of two different natural sands are presented, and the distributions of fall velocities are found to be in good agreement with the predicted distributions. The sedimentation diameters determined from the measured fall velocities agree very well with those predicted from the sieve diameters by the Inter-Agency Committee on Water Resources [1957]
Exploring heritage through time and space : Supporting community reflection on the highland clearances
On the two hundredth anniversary of the Kildonan clearances, when people were forcibly removed from their homes, the Timespan Heritage centre has created a program of community centred work aimed at challenging pre conceptions and encouraging reflection on this important historical process. This paper explores the innovative ways in which virtual world technology has facilitated community engagement, enhanced visualisation and encouraged reflection as part of this program. An installation where users navigate through a reconstruction of pre clearance Caen township is controlled through natural gestures and presented on a 300 inch six megapixel screen. This environment allows users to experience the past in new ways. The platform has value as an effective way for an educator, artist or hobbyist to create large scale virtual environments using off the shelf hardware and open source software. The result is an exhibit that also serves as a platform for experimentation into innovative ways of community co-creation and co-curation.Postprin
Spatially Resolved Images of Dust Belt(s) Around the Planet-hosting Subgiant Kappa CrB
We present Herschel spatially resolved images of the debris disc orbiting the
subgiant Kappa CrB. Not only are these the first resolved images of a debris
disc orbiting a subgiant, but Kappa CrB is a rare example of an intermediate
mass star where a detailed study of the structure of the planetary system can
be made, including both planets and planetesimal belt(s). The only way to
discover planets around such stars using the radial velocity technique is to
observe 'retired' A stars, which are cooler and slower rotators compared to
their main-sequence counterparts. A planetary companion has already been
detected orbiting the subgiant Kappa CrB, with revised parameters of m sin i =
2.1MJ and apl = 2.8AU (Johnson et al. 2008a). We present additional Keck I
HIRES radial velocity measurements that provide evidence for a second planetary
companion, alongside Keck II AO imaging that places an upper limit on the mass
of this companion. Modelling of our Herschel images shows that the dust is
broadly distributed, but cannot distinguish between a single wide belt (from 20
to 220AU) or two narrow dust belts (at around 40 and 165AU). Given the
existence of a second planetary companion beyond approximately 3AU it is
possible that the absence of dust within approximately 20AU is caused by
dynamical depletion, although the observations are not inconsistent with
depletion of these regions by collisional erosion, which occurs at higher rates
closer to the star.Comment: Updated abstrac
REALTIME FRAUD DETECTION IN THE BANKING SECTOR USING DATA MINING TECHNIQUES/ALGORITHM
Abstract—The banking sector is a very important sector in
our present day generation where almost every human has to
deal with the bank either physically or online. In dealing with
the banks, the customers and the banks face the chances of
been trapped by fraudsters. Examples of fraud include
insurance fraud, credit card fraud, accounting fraud, etc.
Detection of fraudulent activity is thus critical to control these
costs. This paper hereby addresses bank fraud detection via
the use of data-mining techniques; association, clustering,
forecasting, and classification to analyze the customer data in
order to identify the patterns that can lead to frauds. Upon
identification of the patterns, adding a higher level of
verification/authentication to banking processes can be added
Keywords: Data mining techniques, banking sector, fraud, and
authentication
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