Preliminary Report on the Fishes of the Upper Saline River, Polk and Howard Counties, Arkansas, and Observations on Their Relationships with Land Use and Physiochemical Conditions

The Saline River of southwest Arkansas was impounded by Dierks Lake in 1975. Intensive collecting efforts were made in the river system above Dierks Lake during March, April, and May 1980. Collected specimens were compared with ichthyofaunal lists prior to impoundment. Historic occurrants which were not collected include Notropis amnis, Notropis ortenburgeri, Moxostoma duquesnei, Ammocrypta vivax, and Percina copelandi. Additions to the ichthyofaunal list for the drainage include Fundulus notatus, Etheostoma spectabile, and Percina caprodes. The evidence indicates that 33 species representing six families inhabit the system from the headwaters in Polk County, Arkansas, to Dierks Lake, Howard County, Arkansas. Erosion within the basin ranges from 956 kilograms per hectare per year on grassland to 158,263 kilograms per kilometer per year on roadbanks. Excessive levels of fecal coliform bacteria, cadmium, copper, lead, zinc, and sulfates were noted within the system. The relationship of these factors to the ichthyofauna is discussed

Age and Growth of the Bluegill Lepomis macrochrius Rafinesque From an Unmanaged Watershed Lake in Northeast Arkansas with Observations on Lake Ecology

Age and growth data were compiled on 114 bluegill, Lepomis macrochirus Rafinesque, taken from floodwater retarding structure #15 of the Big Creek Watershed project in Craighead and Greene counties of northeast Arkansas. This project was completed in the early 1960\u27s by USDA-SCS. The 73 surface acre lake has not been managed for fish production and has been subjected to unscheduled water level manipulations during dry weather periods. These manipulations have maintained the bluegill population in healthy condition. The oldest bluegill collected were age class IV+. Average condition coefficient K(TL)declined from oldest to youngest individuals (2.96 in age class IV+ - 2.20 in age class I+ ), while numbers in age class declined from the youngest to the oldest within the sample (age class IV+ = 1[0.8%]; age class I+ = 74 [64.9%]). The length-scale radius relationship was L = 9.51 + 46.92S, with a correlation coefficient (r) of 0.96. The length (60-178 mm)-weight (4.7-1 55. 9g) relationship (Log W = 1 .4 Log L- 1.37) indicates that weight has not increased as the cube of length. The utility of drawdown as a fishery management technique is discussed

Continued DDT Persistence in Mississippi River Delta Streams: A Case Study

Fish samples representative of several trophic levels were taken from the Wolf and Loosahatchie Rivers of western Tennessee during the early 1980s. Results indicate that DDT, with metabolites DDD and DDE, remains common in fish tissues in these areas and approaches the levels recommended as maxima for human consumption by the U.S. Food and Drug Administration. Samples of top carnivores and forage fishes, particularly the gizzard shad, Dorosoma cepedlanum, commonly exceeded 500 ppb DDE. The results are discussed in light of sediment disturbing activities

Note on the Relativistic Thermodynamics of Moving Bodies

We employ a novel thermodynamical argument to show that, at the macroscopic level,there is no intrinsic law of temperature transformation under Lorentz boosts. This result extends the corresponding microstatistical one of earlier works to the purely macroscopic regime and signifies that the concept of temperature as an objective entity is restricted to the description of bodies in their rest frames. The argument on which this result is based is centred on the thermal transactions between a body that moves with uniform velocity relative to a certain inertial frame and a thermometer, designed to measure its temperature, that is held at rest in that frame.Comment: To be published in J. Phys. A. A few minor corrections have been made to the earlier version of this articl

Variational approach to transport in quantum dots

We have derived a variational principle that defines the nonequilibrium steady-state transport across a correlated impurity mimicking, e.g., a quantum dot coupled to biased leads. This variational principle has been specialized to a Gutzwiller's variational space, and applied to the study of the simple single-orbital Anderson impurity model at half filling, finding a good qualitative accord with the observed behavior in quantum dots for the expected regime of values of the bias. Beyond the purely theoretical interest in the formal definition of a variational principle in a nonequilibrium problem, the particular methods proposed have the important advantage to be simple and flexible enough to deal with more complicated systems and variational spaces.Comment: 15 pages, 4 figure

A describing function for resonantly commutated H-bridge inverters

Abstract—The paper presents the derivation of a describing function to model the dynamic behavior of a metal oxide semiconductor field effect transistor-based, capacitively commutated H-bridge, including a comprehensive explanation of the various stages in the switching cycle. Expressions to model the resulting input current, are also given. The derived model allows the inverter to be accurately modeled within a control system simulation over a number of utility input voltage cycles, without resorting to computationally intensive switching-cycle level, time-domain SPICE simulations. Experimental measurements from a prototype H-bridge inverter employed in an induction heating application, are used to demonstrate a high degree of prediction accuracy over a large variation of load conditions is possible using the simplified model

An investigation of the effects of radiation on silicon nitride insulated gate /MNS/ transistors Final report

Radiation effects on silicon nitride insulated gate field effect transistor