162,056 research outputs found
Low-Temperature Thermal-Energy Storage and Transmission Systems Employing Hydrophilic Polymeric Materials
No full textThe wide fluctuations that occur in the aggregate electrical demand of a generating
utility are punitive with respect to total system efficiency. Demand side management
techniques have been applied to reduce such fluctuations including the conversion of
electrical energy to thermal energy during periods of low demand for use during peak
demand periods. For thermal processes requiring energy above ambient temperature it
is feasible to use sensible heat due to the existence of stable storage mediums and
efficient methods of heating at the high temperatures required. However where energy
is required below ambient temperatures, efficiency of cooling limits the use of sensible
heat, hence latent heat storage has been adopted. Conventional cold storage systems use
ice banks to store cooling energy at 0°C in order to capture the high latent heat of
fusion of water. The rate of discharge for such stores is limited by thermal resistance in
the store and the thermal capacity of secondary coolants (such as glycol solutions).
This investigated the use of hydrophilic materials to overcome the limitations of
current cold-storage technology. Such materials have the capacity to absorb and retain
up to 95% by mass of water (or other aqueous solutions) regardless of how the
materials is subdivided. Furthermore the thermal properties of the polymers in their
hydrated state resemble those of the free hydration fluid, including any phase
transitions. By supporting the hydrated materials in a non-freeing, non-aqueous fluid
the resultant mixture provides a medium for cold storage that can be pumped and used
at the point of load, and is not limited by the thermal resistance of an encapsulating
material.
Three aspects concerning the utilisation of hydrophilic materials for thermal
engineering applications have been investigated; (i) the physical properties of the
materials
in their hydrated state, (ii) methods of fluidising material in a high density
store, and (iii) the heat transfer properties of hydrophilic based slurries while
undergoing phase transition.
Material tests have shown that currently available hydrophilic materials have thermo-
physical properties that depend principally upon the hydrating fluid, regardless of
particle size, and are stable over long periods (>3years). Suitable hydration fluids can
lower the temperature of the phase transition thus extending their potential as storage
mediums beyond those of ice-based technologies. Novel materials, of very high water
content (95%) have been produced and investigated. These appear to be very suitable
for thermal storage because they increase the maximum achievable energy densities of
a fluidised storage system and potentially reduce cost.
A number of thermal storage devices to utilise hydrophilic based slurries have been
designed and evaluated. The resultant devices has been shown to provide a means of
taking hydrophilic materials to, and from, a packed bed and feeding them at a
controlled rate into a fluid stream. The thermal charge/discharge rates of such a device
are limited only by the choice of external heat exchange systems. An experimental apparatus has been designed to investigate the effects of phase change
particles on the heat transfer properties of flowing mixtures. The results have shown
that (i) at temperatures above the phase transition temperature the presence of the
particles causes an increase in the measured heat transfer coefficient for concentrations
above 10% by volume, (ii) there is a significant interaction of particles at the heat
transfer surface, and (iii) that under high flow rate conditions, with phase change
occurring, heat transfer coefficients are considerably enhanced (ie 80%) above those of
the support fluid when used alone or with non-active particles.
Further work is recommended to extend this study to produce an engineering prototype
storage system for trial evaluation
Novel hydrophilic polymer couplant for application in ultrasonic non destructive testing
No full textUltrasonic Non Destructive Testing (NDT) is used to inspect materials and
structures for defects. Water is commonly used in NDT as a couplant to
improve ultrasonic transfer between an interrogating probe and test piece.
Unfortunately, the presence of water can cause corrosion and/or degradation
of the test piece material. The aim of this investigation was to evaluate
hydrated cross-linked hydrophilic polymers as candidate solid contact
ultrasonic couplant for use in the field of ultrasonic NDT.
The fact that hydrophilic polymers can absorb and retain large quantities of
water suggested that they might demonstrate the desirable ultrasonic
properties of water without the risks associated with conventional water
coupling. To test this, the ultrasonic properties of a range of hydrophilic
polymers were assessed. Excellent results were achieved, attenuation as low
as 0.36 and 0.71dB mm-1 at 5 and 1OMHz respectively being measured.
Great potential for efficient coupling was established due to acoustic
impedance in the region of 1.81VIN S M-3.
A polymer dependant coupling pressure of less that 1kg CM-2 was required to
achieve optimum coupling to a smooth steel block. Mechanical longevity,
evaluated by life testing, showed that polymers of up to 70% equilibrium water
content were best suited for dynamic testing applications. Temperature was
shown to effect ultrasonic properties; a drop from 5 to
-120C caused an
increase in attenuation of 3dB mm-1 and velocity of 350m s-1. Pressure
demonstrated no influence on attenuation but affected an increase in velocity
of 44m s-1 per kg CM-2
.
Further investigation into the unique ultrasonic
properties of hydrophilic polymers showed that the water sorption process
caused an increase in attenuation prior to saturation being reached. This was
attributed to the absorption of sound during the polymer transformation from
the glassy to rubbery condition observed during hydration. Dehydration from
100 to 37% saturation in a 60% equilibrium water content polymer caused an
increase in attenuation of 1.8dB mm-1 at 5MHz.
The research concluded with the design and development of a prototype
wheel probe employing hydrophilic polymer as the tyre. Operation at 5MHz in
pulse echo mode demonstrated results competitive to conventional immersion
testing. An MMA-VP cross-linked hydrophilic polymer of approximately 60%
equilibrium water content was found most suitable to this application.
This thesis suggests that there is a clear role for hydrophilic polymers in
ultrasonic NDT. The success of the wheel probe design developed as a result
of this research has resulted in patent application in both the UK and USA
[Report to Chief J. E. Curry, by an unknown author #1]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
[Report to Chief J. E. Curry, by an unknown author #2]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
Refrigeration appliances : Performance enchancements via novel thermal-energy storage
No full textIn recent
*
years there has been increasing concern for the environmental impacts
of economic and technological development. This (principally socio-political) con-
cern has led to the well-known series of environmentall
,y
motivated (global and
local) conventions, agreements and legislation put forward in a bid to manage these
environmental impacts, which in turn has led to research and commercial activ-
ity on environmental issues. One of the major activities identified as adversely
impacting the environment is the manner in which energy is currently harnessed,
inter-converted and utilised. Cont/d
Murder on the mountain: author talk with Peter J. Wosh
No full textAuthor talk by Peter J. Wosh on May 5th, 2022, on his book, "Murder on the Mountain: crime, passion, and punishment in gilded age New Jersey.
Mr. Melvin J. Collier, RWWL AUC, June 2011
No full textThis video is a conversation with Mr. Melvin J. Collier. Mr. Collier talks about his book, "From Mississippi to Africa: A Journey of Discovery". Daniel Le, AUC Woodruff Library, is the interviewer
A Tripartite Post-Recession Rebalancing
No full textIn this latest Advance & Rutgers Report, entitled “A Tripartite Post-Recession Rebalancing,” Dean James W. Hughes and Professor Joseph J. Seneca deliver an incisive assessment of the current market conditions and obstacles in the path of our economic recovery. They offer a statistical cautionary tale that the private and public sector need to hear and acknowledge in order for the economy to make continued progress.This report was published as Issue Paper Number 7, November 2011, in Advance & Rutgers Report
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
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