A Study of the Effects of Ionic Charge and Molecular Weight of Polymers on Wet-Web Strength

Improved machine speeds in the production of paper have increased the number of wet-end breaks due to wet-webs that are unable to withstand the increased stresses at increased rates of production. Lyne and Gallay layed the cornerstone on which most of today s knowledge of wet-web strength is built. This research attempted to expand on this knowledge by determining whether chemicals could be employed to improve wet-web strength. The results of this experiment indicates that cationic polymers do improve wet-web strength at levels of addition of 160 lbs/ton of pulp and 1600 lbs/ton of pulp. This indicates that cationic polymers are a potential means of improving wet-web strength

Exploratory Pollen Analysis of Hargrove Lake, Davy Crockett National Forest Houston County, Texas

The objectives of this exploratory pollen analysis of selected samples from a sediment core taken at Hargrove Lake, Davy Crockett National Forest, Houston County, Texas, are to ascertain the quality of pollen preservation in the lake bottom matrix and to evaluate the potential of the pollen spectra deposited in the lake for providing information about former environmental conditions on Davy Crockett National Forest. Hargrove Lake is a natural lake in the floodplain of the Neches River in Houston County, Texas. The Hargrove Lake site (41H0150) lies a short distance to the west. The lake is presently is surrounded by a 10m wide stand of buttonbush (Cephalanthus). These plants are three m tall and have two to ten em diameter trunks. A woodland dominated by water oaks (Quercus nigra) and sweetgum (Liquidambar styraciflua) lies beyond the button bush. These trees are 30 to 40 m tall, and the woodland canopy is 90 to 98 percent closed. The lake is normally about 50 m wide by 200 m long, giving it a normal surface area of approximately 2.5 hectares. The mean depth of the lake at high water is about 90 em. Bedrock marl underlies the area, and the lake retains water during even the most severe droughts. It should provide a continuous pollen deposition record

MANAGEMENT AND USE OF LAND AS A PUBLIC GOOD

Land Economics/Use,

Probing Exotic Physics With Supernova Neutrinos

Future galactic supernovae will provide an extremely long baseline for studying the properties and interactions of neutrinos. In this paper, we discuss the possibility of using such an event to constrain (or discover) the effects of exotic physics in scenarios that are not currently constrained and are not accessible with reactor or solar neutrino experiments. In particular, we focus on the cases of neutrino decay and quantum decoherence. We calculate the expected signal from a core-collapse supernova in both current and future water Cerenkov, scintillating, and liquid argon detectors, and find that such observations will be capable of distinguishing between many of these scenarios. Additionally, future detectors will be capable of making strong, model-independent conclusions by examining events associated with a galactic supernova's neutronization burst.Comment: 19 pages, 6 figure

Synchrotron Emission From Young And Nearby Pulsars

The rising cosmic ray positron fraction reported by the PAMELA collaboration has lead to a great deal of interest in astrophysical sources of energetic electrons and positrons, including pulsars. In this paper, we calculate the spectrum of synchrotron emission from electrons and positrons injected from 376 young pulsars (<10^6 years) contained in the ATNF catalog, and compare our results to observations. We find that if objects such as the Vela and Crab pulsars have injected ~10^48 erg or more in energetic electrons and/or positrons, they are expected to produce bright and distinctive features in the synchrotron sky. Intriguingly, we predict hard synchrotron emission from these regions of the sky which is qualitatively similar to that observed by WMAP.Comment: 11 pages, 4 figure

VALUES, BELIEFS AND MYTHS IN NATURAL RESOURCES POLICY MAKING

Resource /Energy Economics and Policy,

Three-dimensional structure of a low-Reynolds-number turbulent boundary layer

A low-Reynolds-number zero-pressure-gradient incompressible turbulent boundary layer was investigated using a volumetric imaging technique. The Reynolds number based on momentum thickness was 700. The flow was tagged with a passive scalar from two spanwise dye slots to distinguish between fluid motions originating in the inner and outer portions of the boundary layer. The resulting volumetric scalar field was interrogated using a laser sheet scanner developed for this study. Two- and three-dimensional time-dependent visualizations of a 50 volume time series are presented (equivalent to 17δ in length). In the outer portion of the boundary layer, scalar structures were observed to lie along lines in the (x, z)-plane, inclined to the streamwise (x-)direction in the range ±50°. The ejection of brightly dyed fluid packets from the near-wall region was observed to be spatially organized, and related to the passage of the large-scale scalar structures.Carl J Delo, Richard M Kelson and Alexander J Smit