3,390 research outputs found

    Sedimentation in an artificial lake -Lake Matahina, Bay of Plenty

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    Lake Matahina, an 8 km long hydroelectric storage reservoir, is a small (2.5 km2), 50 m deep, warm monomictic, gorge-type lake whose internal circulation is controlled by the inflowing Rangitaiki River which drains a greywacke and acid volcanic catchment. Three major proximal to distal subenvironments are defined for the lake on the basis of surficial sediment character and dominant depositional process: (a) fluvial-glassy, quartzofeld-spathic, and lithic gravel-sand mixtures deposited from contact and saltation loads in less than 3 m depth; (b) (pro-)deltaic-quartzofeldspathic and glassy sand-silt mixtures deposited from graded and uniform suspension loads in 3-20 m depth; and (c) basinal-diatomaceous, argillaceous, and glassy silt-clay mixtures deposited from uniform and pelagic suspension loads in 20-50 m depth. The delta face has been prograding into the lake at a rate of 35-40 m/year and vertical accretion rates in pro-delta areas are 15-20 cm/year. Basinal deposits are fed mainly from river plume dispersion involving overflows, interflows, and underflows, and by pelagic settling, and sedimentation rates behind the dam have averaged about 2 cm/year. Occasional fine sand layers in muds of basinal cores attest to density currents or underflows generated during river flooding flowing the length of the lake along a sublacustrine channel marking the position of the now submerged channel of the Rangitaiki River

    C*-Algebras with the Approximate Positive Factorization Property

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    We say that a unital C*-algrebra A has the approximate positive factorization property (APFP) if every element of A is a norm limit of products of positive elements of A. (There is also a definition for the nonunital case.) T. Quinn has recently shown that a unital AF algebra has the APFP if and only if it has no finite dimensional quotients. This paper is a more systematic investigation of C*-algebras with the APFP. We prove various properties of such algebras. For example: They have connected invertible group, trivial K_1, and stable rank 1. In the unital case, the K_0 group separates the tracial states. The APFP passes to matrix algebras. and if I is an ideal in A such that I and A/I have the APFP, then so does A. We also give some new examples of C*-algebras with the APFP, including type II_1 factors and infinite-dimensional simple unital direct limits with slow dimension growth, real rank zero, and trivial K_1 group. An infinite- dimensional simple unital direct limit with slow dimension growth and with the APFP must have real rank zero, but we also give examples of unital algebras with the APFP which do not have real rank zero. Our analysis also leads to the introduction of a new concept of rank for a C*-algebra that may be of interest in the future.Comment: plain TeX; 19 page

    Pricing Excess-of-loss Reinsurance Contracts Against Catastrophic Loss

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    This paper develops a pricing methodology and pricing estimates for the proposed Federal excess-of- loss (XOL) catastrophe reinsurance contracts. The contracts, proposed by the Clinton Administration, would provide per-occurrence excess-of-loss reinsurance coverage to private insurers and reinsurers, where both the coverage layer and the fixed payout of the contract are based on insurance industry losses, not company losses. In financial terms, the Federal government would be selling earthquake and hurricane catastrophe call options to the insurance industry to cover catastrophic losses in a loss layer above that currently available in the private reinsurance market. The contracts would be sold annually at auction, with a reservation price designed to avoid a government subsidy and ensure that the program would be self supporting in expected value. If a loss were to occur that resulted in payouts in excess of the premiums collected under the policies, the Federal government would use its ability to borrow at the risk-free rate to fund the losses. During periods when the accumulated premiums paid into the program exceed the losses paid, the buyers of the contracts implicitly would be lending money to the Treasury, reducing the costs of government debt. The expected interest on these "loans" offsets the expected financing (borrowing) costs of the program as long as the contracts are priced appropriately. By accessing the Federal government's superior ability to diversify risk inter-temporally, the contracts could be sold at a rate lower than would be required in conventional reinsurance markets, which would potentially require a high cost of capital due to the possibility that a major catastrophe could bankrupt some reinsurers. By pricing the contacts at least to break even, the program would provide for eventual private-market "crowding out" through catastrophe derivatives and other innovative catastrophic risk financing mechanisms. We develop prices for the contracts using two samples of catastrophe losses: (1) historical catastrophic loss experience over the period 1949-1994 as reported by Property Claim Services; and (2) simulated catastrophe losses based on an engineering simulation analysis conducted by Risk Management Solutions. We used maximum likelihood estimation techniques to fit frequency and severity probability distributions to the catastrophic loss data, and then used the distributions to estimate expected losses under the contracts. The reservation price would be determined by adding an administrative expense charge and a risk premium to the expected losses for the specified layer of coverage. We estimate the expected loss component of the government's reservation price for proposed XOL contracts covering the entire U.S., California, Florida, and the Southeast. We used a loss layer of $25-50 billion for illustrative purposes.

    SUPPLY AND DEMAND RISKS IN LABORATORY FORWARD AND SPOT MARKETS: IMPLICATIONS FOR AGRICULTURE

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    Laboratory experimental methods are used to investigate the impacts of supply and/or demand risks on prices, quantities traded, and earnings within forward and spot market institutions. Random demand and/or supply shifts can be as much as 25 percent of the expected equilibrium outcome. Nevertheless, results suggest that the spot or forward trading institution itself has a greater influence on market outcomes than the presence of risk within the trading institutions. Sellers tend to have relatively higher earnings in a spot market than buyers, regardless of the risk. Total surplus, however, generally is greater in a forward market.laboratory markets, forward market, spot market, supply and/or demand risks, Demand and Price Analysis, Marketing,

    SUPPLY AND DEMAND RISKS IN FORWARD AND SPOT MARKETS: IMPLICATIONS FOR AGRICULTURE

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    Laboratory methods are used to investigate the impacts of supply and/or demand risks on prices, quantities traded, and earnings within forward and spot market institutions. Results suggest that the spot or forward trading institution itself has a greater influence on market outcomes than supply/demand risks within the institution.Marketing,

    Freshwater mollusk sampling along the southern I-294 corridor.

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    Sampled 8 sites at 6 stream crossings• Spent 13.5 person-hours surveying (average of 2.3 mussels collected/hr)• Encountered 31 live individuals of 3 mussel species• Only 2 of the 8 sites had mussels• Recorded the following species:▷Giant Floater, Pyganodon grandis (n=29, 94%), most common▷Paper Pondshell, Utterbackia imbecillus (n=1, 3%)▷Lilliput, Toxolasma parvum (n=1, 3%)▷One native snail, Liver Elimia, Elimia livescens, was abundant in Salt Creek• Invasive Asian Clams, Corbicula fluminea, were common at sites▷Upstream reach of I-294 to Bemis Woods littered with relict shells of native unionidsIllinois State Toll Highway Authorityunpublishednot peer reviewe

    Biotic Integrity of macroinvertebrate communities along the I-294 corridor

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    Sampled macroinvertebrates following ILEPA protocol at 7 sites in August–September 2015 in the I-294 corridor and calculated biotic integrity metrics • Assessed sites based on the Qualitative Stream Habitat Assessment Procedure (SHAP) • Measured physical (width, depth, velocity) and chemical (pH, conductivity, salinity, total dissolved solids) characteristics • Habitat assessment showed impairment compared to Illinois reference conditions at all sites • Macroinvertebrate Index of Biotic Integrity rated 6 sites as “Poor” and one as “Fair” ▷▷ Total taxa richness ranged from 10 to 19 across sites ▷▷ 4 of the 7 sites had no EPT (Ephemeroptera, Plecoptera, Trichoptera) taxa ▷▷ No Plecoptera (stoneflies) were collected at any siteIllinois State Toll Highway Authorityunpublishednot peer reviewe

    Impact abrasion resistance quantification of protective motorcycle gloves

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    The hands are often the first contact point with the road surface in a motorcycle crash. Wearing well designed protective gloves has been proven to significantly reduce the occurrence and severity of injuries to the hand. The European Standard for motorcycle protective gloves requires testing of component materials separately and does not consider the impact of abrasive surfaces on seems. This work aimed to develop a new method of testing of fully constructed gloves as worn by a rider in impact abrasion situations. It used previously published fall mechanics to understand the areas that may undergo impact abrasion. It defines the important zones for abrasion resistance and details ideal impact/measurement geometry for measurement on a Cambridge type abrasion tester. It proposes a method for the impact abrasion resistance of the palm, knuckles, wrist, outer side of the little finger and the tops of fingers. This information may be used for the quantification of fully manufactured gloves for standard certification or use in a rating system

    Measuring Motivation and Reward-Related Decision Making in the Rodent Operant Touchscreen System.

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    This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1002/0471142301.ns0834s74This unit is designed to facilitate implementation of the fixed and progressive ratio paradigms and the effort-related choice task in the rodent touchscreen apparatus to permit direct measurement of motivation and reward-related decision making in this equipment. These protocols have been optimized for use in the mouse and reliably yield stable performance levels that can be enhanced or suppressed by systemic pharmacological manipulation. Instructions are also provided for the adjustment of task parameters to permit use in mouse models of neurodegenerative disease. These tasks expand the utility of the rodent touchscreen apparatus beyond the currently available battery of cognitive assessment paradigms.The protocols presented in this Unit were developed and optimized as part of a research program funded by Wellcome Trust grant 089703/Z/09/Z awarded to TJB and LMS. TJB and LMS also received funding from the Innovative Medicine Initiative Joint Undertaking under grant agreement n° 115008 of which resources are composed of EFPIA in-kind contribution and financial contribution from the European Union’s Seventh Framework Programme (FP7/2007- 2013). TJB and LMS consult for Campden Instruments Ltd
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