Southeastern U.S. Deepwater Reef Fish Assemblages, Habitat Characteristics, Catches, and Life History Summaries

There are 19 economically important reef fish species in the deepwater (l00-300 m) fishery of the southeastern United States. Five species make up the majority (over 97% by weight) of the catch. In descending order of total landings for 1995, they are: tilefish, Lopholatilus chamaeleonticeps, snowy grouper, Epinephelus niveatus, blueline tilefish, Caulolatilus microps, warsaw grouper, Epinephelus nigritus, and yellowedge grouper, E. flavolimbatus. Life history summaries and estimates of catches from 1972 through 1995 for 14 species are described. (PDF file contains 45 pages.

Oxide-dispersion-strengthened turbine blades, volume 1

The objective of Project 4 was to develop a high-temperature, uncooled gas turbine blade using MA6000 alloy. The program objectives were achieved. Production scale up of the MA6000 alloy was achieved with a fair degree of tolerance to nonoptimum processing. The blade manufacturing process was also optimized. The mechanical, environmental, and physical property evaluations of MA6000 were conducted. The ultimate tensile strength, to about 704 C (130 F), is higher than DS MAR-M 247 but with a corresponding lower tensile elongation. Also, above 982 C (180 F) MA6000 tensile strength does not decrease as rapidly as MAR-M 247 because the ODS mechanism still remains active. Based on oxidation resistance and diffusional stability considerations, NiCrAlY coatings are recommended. CoCrAly coating should be applied on top of a thin NiCrAlY coating. Vibration tests, whirlpit tests, and a high-rotor-rig test were conducted to ensure successful completion of the engine test of the MA6000 TFE731 high pressure turbine blades. The results of these tests were acceptable. In production quantities, the cost of the Project 4 MA6000 blade is estimated to be about twice that of a cast DS MAR-M 247 blade

Advanced methodologies for design of storm sewer systems

This report describes the development of a series of computer models capable of determining the diameter, slope and crown elevations of each sewer in a storm drainage system in which the layout and manhole locations are predetermined. The criterion for design decisions is the generation of a least-cost system. The basis for all of the models is the application of discrete differential dynamic programing (DDDP) as the optimization tool. Two important concepts are introduced as optimal model components: hydrograph routing and risks and uncertainties in designs. Three routing procedures are adopted, each with its own advantages. Expected flood damage costs are evaluated through the analysis of numerous risks and uncertainties associated with the design. This analysis permits the estimation of the probability of exceeding the capacity and the corresponding expected assessed damage of any sewer in the system. The expected damage cost is added to the installation cost to obtain the total cost which is then minimized in the DDDP procedure. Two example sewer systems are used as a basis for illustrating different aspects of the various least-cost design models and developing user guidelines.U.S. Department of the InteriorU.S. Geological SurveyOpe

Illinois least-cost sewer system design model: ILSD-1 & 2 user’s guide

ILSD models are sewer system models for least-cost optimal design of the entire system. ILSD-1 designs for a specified layout the size and slope of the sewers with or without detention storages with user supplied rainfall and/or inlet hydrographs. ILSD-2 is similar to ILSD-1 but also with risk consideration; i.e., with the risk damage cost included in the optimization procedure and a risk equation supplied by the user. The user may choose either ILSD-1 or 2 as he (she) wishes and according to the available data. This user's guide provides the necessary information to use the computer program. Data preparation for various options to fit different engineering situations is presented.U.S. Department of the InteriorU.S. Geological SurveyOpe

Diversity of Flowering Responses in Wild Arabidopsis thaliana Strains

Although multiple environmental cues regulate the transition to flowering in Arabidopsis thaliana, previous studies have suggested that wild A. thaliana accessions fall primarily into two classes, distinguished by their requirement for vernalization (extended winter-like temperatures), which enables rapid flowering under long days. Much of the difference in vernalization response is apparently due to variation at two epistatically acting loci, FRI and FLC. We present the response of over 150 wild accessions to three different environmental variables. In long days, FLC is among those genes whose expression is most highly correlated with flowering. In short days, FRI and FLC are less important, although their contribution is still significant. In addition, there is considerable variation not only in vernalization response, but also in the response to differences in day length or ambient growth temperature. The identification of accessions that flower relatively early or late in specific environments suggests that many of the flowering-time pathways identified by mutagenesis, such as those that respond to day length, contribute to flowering-time variation in the wild. In contrast to differences in vernalization requirement, which are mainly mediated by FRI and FLC, it seems that variation in these other pathways is due to allelic effects at several different loci