Gas Turbine Emissions Improvements by Advances in Design, Analysis, Materials, Manufacturing, and Control Technology

TutorialThis tutorial provides a general overview of the state of gas turbine combustion technology. Fundamental considerations for key pollutants are discussed along with techniques to control them. Since the commercial introduction of lean combustion in the early 1990s, it has become the preferred technology to minimize NOx emissions from a gas turbine, while Selective Catalytic Reduction (SCR) has remained a necessary technique to further reduce NOx emissions in some regulated areas with poor air quality. Improved designs have been enabled by more capable analysis, manufacturing techniques, and materials. All of this is leading to lower emissions engines with greater fuel flexibility and durability. Traditional diffusion flame combustion systems generate NOx between 100 and 400 ppm on natural gas, while early DLE systems started at 42 ppm and are now capable of single digit NOx

The Effect of Spacing and Time of Thinning on the Yield, Growth, and Fruiting Characteristics of the Cotton Plant in 1925.

38 p

Gas Turbine Emissions Improvements by Advances in Design, Analysis, Materials, Manufacturing, and Control Technology

TutorialThis tutorial provides a general overview of the state of gas turbine combustion technology. Fundamental considerations for key pollutants are discussed along with techniques to control them. Since the commercial introduction of lean combustion in the early 1990s, it has become the preferred technology to minimize NOx emissions from a gas turbine, while Selective Catalytic Reduction (SCR) has remained a necessary technique to further reduce NOx emissions in some regulated areas with poor air quality. Improved designs have been enabled by more capable analysis, manufacturing techniques, and materials. All of this is leading to lower emissions engines with greater fuel flexibility and durability. Traditional diffusion flame combustion systems generate NOx between 100 and 400 ppm on natural gas, while early DLE systems started at 42 ppm and are now capable of single digit NOx

Peanut Growing in the Gulf Coast Prairie of Texas.

16 p

The Effect of Spacing and Time of Thinning on the Yield, Growth, and Fruiting Characteristics of the Cotton Plant in 1925.

38 p

Management by objectives at a research development, test and evaluation activity

NAVMAT Instruction 5200.37 of 24 September 1973 required a Management by Objectives (MBO) program to be initiated throughout the Naval Material establishment. The Pacific Missile Range (PMR) at Point Mugu , California requested assistance from the Naval Postgraduate School in establishing their MBO program. A pilot MBO program was established at PMR to determine MBO • s feasibility in a research and development (R§D) organization. Due to time constraints, the program was limited to the implementation of short range goals and objectives. Although R§D objectives for work of an innovative nature were often difficult to define and measure, preliminary results indicate that the concept of MBO can be effectively applied to an R&D activity.http://archive.org/details/managementbyobje00blosApproved for public release; distribution is unlimited

Tumor suppressor p53 binds with high affinity to CTG-CAG trinucleotide repeats and induces topological alterations in mismatched duplexes

DNA binding is central to the ability of p53 to function as a tumor suppressor. In line with the remarkable functional versatility of p53, which can act on DNA as a transcription, repair, recombination, replication, and chromatin accessibility factor, the modes of p53 interaction with DNA are also versatile. One feature common to all modes of p53-DNA interaction is the extraordinary sensitivity of p53 to the topology of its target DNA. Whereas the strong impact of DNA topology has been demonstrated for p53 binding to sequence-specific sites or to DNA lesions, the possibility that DNA structure-dependent recognition may underlie p53 interaction with other types of DNA has not been addressed until now. We demonstrate for the first time that conformationally flexible CTG·CAG trinucleotide repeats comprise a novel class of p53-binding sites targeted by p53 in a DNA structure-dependent mode in vitro and in vivo. Our major finding is that p53 binds to CTG·CAG tracts by different modes depending on the conformation of DNA. Although p53 binds preferentially to hairpins formed by either CTG or CAG strands, it can also bind to linear forms of CTG·CAG tracts such as canonic B DNA or mismatched duplex. Intriguingly, by binding to a mismatched duplex p53 can induce further topological alterations in DNA, indicating that p53 may act as a DNA topology-modulating factor

Exploring mortgage interest deduction reforms: An equilibrium sorting model with endogenous tenure choice

In most equilibrium sorting models (ESMs) of residential choice across neighborhoods, the question of whether households rent or buy their home is either ignored or else tenure status is treated as exogenous. Of course, tenure status is not exogenous and households' tenure choices may have important public policy implications, particularly since higher levels of homeownership have been shown to correlate strongly with various indicators of improved neighborhood quality. Indeed, numerous policies including that of mortgage interest deduction (MID) have been implemented with the express purpose of promoting homeownership. This paper presents an ESM with simultaneous rental and purchase markets in which tenure choice is endogenized and neighborhood quality is partly determined by neighborhood composition. The public policy relevance of the model is shown through a calibration exercise for Boston, Massachusetts, which explores the impacts of various reforms to the MID policy. The simulations confirm some of the arguments made about reforming MID but also demonstrate how the complex patterns of behavioral change induced by policy reform can lead to unanticipated effects. The results suggest that it may be possible to reform MID while maintaining the prevailing rates of homeownership and reducing the federal budget deficit

Pasture Improvement in the Gulf Coast Prairie of Texas.

43 p