3,767 research outputs found
Toughened uni-piece fibrous insulation
A porous body of fibrous, low density silica-based insulation material is at least in part impregnated with a reactive boron oxide containing borosilicate glass frit, a silicon tetraboride fluxing agent and a molybdenum silicide emittance agent. The glass frit, fluxing agent and emittance agent are separately milled to reduce their particle size, then mixed together to produce a slurry in ethanol. The slurry is then applied to the insulation material and sintered to produce the porous body
Global Projections of Household Numbers Using Age Determined Ratios
A new method based upon age determined population ratios is described and used to estimate household population intensities (households per person). Using an additive and a bounded model household projections are given to 2050 for the world and to 2030 for seven fertility transition subgroups (cohorts) of the countries of the world. Based upon United Nations 2002 Revision data, from an estimated 1.56 billion households at 2000, household growth to 2030 is projected to be an additional 1.1 billion households, whether population increase is 1.3 billion persons under the United Nations low fertility variant or 2.7 billion persons under the high fertility variant. At that date over one third of all households are projected to be Chinese or Indian. By 2050 it is projected that there will be 3.3 billion households with a 95 per cent confidence interval on modelling error only of ± 0.5 billion. This compares with 3.2 billion in the Habitat: Global Report on Human Settlements 1996. The apparent similarity of total household growth under various scenarios conceals a wide range in the growth of household intensities across fertility transition cohorts. It is suggested that models, projections and error be reviewed biennially and that household and population projections be produced jointly.Household projections, world, age ratios, fertility
The 230 V CBEMA curve - Preliminary studies
The ITI, formerly CBEMA, curve was developed by the Information Technology Industry Council of the United States of America. The curve describes an AC input voltage envelope which typically can be tolerated by most Information Technology (IT) Equipment. Although the curve ostensibly applies only to IT equipment it is often used throughout the electricity supply industry to provide an indication of the input voltage tolerance of a wide range of equipment. In spite of the fact that the curve was designed to apply to equipment supplied at 120 V 60 Hz nominal voltages it is widely used in Australia which has a 230 V 50 Hz system. This paper details a preliminary study aimed at developing a CBEMA style curve to suit Australian conditions. A range of domestic equipment has been tested to determine sag susceptibility. The types of equipment tested are not limited to IT equipment and represent a cross section of appliances likely to be found in most homes. Overall, results for domestic appliances show that equipment connected to the Australian 230 V network has sag immunity considerably greater than that defined by the ITI Curve. As such, the applicability of the curve for individual pieces of equipment connected to Australian 230 V electricity networks is highly questionable and the need for further work in this area is apparent
Three-Omega Thermal-Conductivity Measurements with Curved Heater Geometries
The three-omega method, a powerful technique to measure the thermal
conductivity of nanometer-thick films and the interfaces between them, has
historically employed straight conductive wires to act as both heaters and
thermometers. When investigating stochastically prepared samples such as
two-dimensional materials and nanomembranes, residue and excess material can
make it difficult to fit the required millimeter-long straight wire on the
sample surface. There are currently no available criteria for how diverting
three-omega heater wires around obstacles affects the validity of the thermal
measurement. In this Letter, we quantify the effect of wire curvature by
performing three-omega experiments with a wide range of frequencies using both
curved and straight heater geometries on SiO/Si samples. When the heating
wire is curved, we find that the measured Si substrate thermal conductivity
changes by only 0.2%. Similarly, we find that wire curvature has no significant
effect on the determination of the thermal resistance of a 65 nm SiO
layer, even for the sharpest corners considered here, for which the largest
measured ratio of the thermal penetration depth of the applied thermal wave to
radius of curvature of the heating wire is 4.3. This result provides useful
design criteria for three-omega experiments by setting a lower bound for the
maximum ratio of thermal penetration depth to wire radius of curvature.Comment: 4 pages, 3 figure
Should the Surety Stand on Its Equitable Subrogation Rights or File Its Indemnity Agreement under the Uniform Commercial Code?
I. Introduction
II. The Hypothetical Case
III. The U.C.C. and Equitable Subrogation ... A. The Bank Has Superior Claims to the Contractor\u27s Assets under the U.C.C. ... B. The Doctrine of Equitable Subrogation ... C. The Tension between the U.C.C. and Equitable Subrogation ... 1. Equitable Subrogation Was Not Replaced by the U .C.C ... 2. Weaknesses of Equitable Subrogation ... 3. Potential Uses of the U.C.C. by Sureties
IV. Analysis of the Hypothetical ... A. Who Gets the Contract Balance? ... 1. Rights under the U.C.C. ... 2. Completion of Performance ... 3. Governing Law ... 4. Conclusions as to Contract Balances ... B. Who Gets the Materials? ... 1. The Bank Has a Perfected Security Interest in the Materials ... 2. The Owner May Have Rights Superior to the Bank\u27s Interest ... 3. The Surety Has No Enforceable Claims to Materials under Equitable Subrogation ... 4. The Surety Has Problems Even If It Filed Its Indemnity Agreement under the U.C.C. ... 5. Conclusion—Materials ... C. Who Gets the Equipment? ... 1. The Bank Has Superior Rights to the Equipment … 2. Equitable Subrogation Does Not Give the Surety Any Rights to Contractor\u27s Equipment ... 3. Filing under the U.C.C. Would Have Given the Surety Rights in the Equipment ... 4. Conclusion—Equipment
V. What Are the Advantages and Disadvantages of Recording the Indemnity Agreement under the U.C.C.? … A. Advantages of Filing under the U.C.C. ... B. Disadvantages of Filing under the U.C.C. ... C. Filing after Default ... D. Filing When Necessary under the Circumstances May Be the Best Solution
VI. Conclusio
Large Scale Proactive Power-Quality Monitoring: An Example from Australia
In Australia and many other countries, distribution network service providers (DNSPs) have an obligation to their customers to provide electrical power that is reliable and of high quality. Failure to do so may have significant implications ranging from financial penalties theoretically through to the loss of a license to distribute electricity. In order to ensure the reliability and quality of supply are met, DNSPs engage in monitoring and reporting practice. This paper provides an overview of a large long-running power-quality monitoring project that has involved most of Australia\u27s DNSPs at one time or another. This paper describes the challenges associated with conducting the project as well as some of the important outcomes and lessons learned. A number of novel reporting techniques that have been developed as part of the monitoring project are also presented. A discussion about large-volume data management, and issues related to reporting requirements in future distribution networks is included
Evolution of an ancient protein function involved in organized multicellularity in animals.
To form and maintain organized tissues, multicellular organisms orient their mitotic spindles relative to neighboring cells. A molecular complex scaffolded by the GK protein-interaction domain (GKPID) mediates spindle orientation in diverse animal taxa by linking microtubule motor proteins to a marker protein on the cell cortex localized by external cues. Here we illuminate how this complex evolved and commandeered control of spindle orientation from a more ancient mechanism. The complex was assembled through a series of molecular exploitation events, one of which - the evolution of GKPID's capacity to bind the cortical marker protein - can be recapitulated by reintroducing a single historical substitution into the reconstructed ancestral GKPID. This change revealed and repurposed an ancient molecular surface that previously had a radically different function. We show how the physical simplicity of this binding interface enabled the evolution of a new protein function now essential to the biological complexity of many animals
Silicon nanoparticles and interstellar extinction
To examine a recently proposed hypothesis that silicon nanoparticles are the
source of extended red emission (ERE) in the interstellar medium, we performed
a detailed modeling of the mean Galactic extinction in the presence of silicon
nanoparticles. For this goal we used the appropriate optical constants of
nanosized Si, essentially different from those of bulk Si due to quantum
confinement. It was found that a dust mixture of silicon nanoparticles, bare
graphite grains, silicate core-organic refractory mantle grains and three-layer
silicate-water ice-organic refractory grains works well in explaining the
extinction and, in addition, results in the acceptable fractions of UV/visible
photons absorbed by silicon nanoparticles: 0.071-0.081. Since these fractions
barely agree with the fraction of UV/visible photons needed to excite the
observed ERE, we conclude that the intrinsic photon conversion efficiency of
the photoluminescence by silicon nanoparticles must be near 100%, if they are
the source of the ERE.Comment: Latex2e, uses emulateapj.sty (included), multicol.sty, epsf.sty, 6
pages, 3 figures (8 Postscript files), accepted for publication in ApJ
Letters, complete Postscript file is also available at
http://physics.technion.ac.il/~zubko/eb.html#SNP
Agricultural intensification and efficiency in the West African savannahs: Evidence from northern Nigeria
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