A Computer Program for the Prediction of Ducted Fan Performance

Manual for computer program for predicting performance of ducted fan

Calibration of a fission gas monitor

Calibration of argon gas neutron activation sampling devic

In the Margins: Reconsidering the Range and Contribution of Diazotrophs in Nearshore Environments

Dinitrogen (N2) fixation enables primary production and, consequently, carbon dioxide drawdown in nitrogen (N) limited marine systems, exerting a powerful influence over the coupled carbon and N cycles. Our understanding of the environmental factors regulating its distribution and magnitude are largely based on the range and sensitivity of one genus, Trichodesmium. However, recent work suggests that the niche preferences of distinct diazotrophic (N2 fixing) clades differ due to their metabolic and ecological diversity, hampering efforts to close the N budget and model N2 fixation accurately. Here, I explore the range of N2 fixation across physico-chemical gradients (e.g., light, nutrients, oxygen) in nearshore environments of significance in global biogeochemical cycling: the major pelagic oxygen deficient zones (ODZs) in the Eastern Tropical South (ETSP) and North (ETNP) Pacific Ocean, and the broad continental shelf of the Western North Atlantic Ocean (WNA). The ODZs are hypothesized to play an important role in N cycle homeostasis by generating conditions thought to promote diazotrophy; recent work suggests that broad continental shelf environments may contribute substantially to new reactive N inputs globally. N2 fixation rates were measured using a robust 15N tracer method that accounts for the slow dissolution of N2 gas. To explore niche partitioning and better characterize spatial heterogeneity on the WNA shelf, I built an empirical model of N2 fixation and investigated diazotroph identity using amplicon sequencing and qPCR. In the ETSP, N2 fixation was only detected in a subset of low-oxygen samples. N2 fixation within the ETNP ODZ was patchy and driven by organic carbon availability; however, significant rates were observed at coastal stations near the Gulf of California. Frontal mixing on the WNA shelf resulted in exceptionally high rates of N2 fixation, associated with high UCYN-A activity. My findings suggest that (1) diazotrophy is more energetically favorable (relative to dissolved inorganic N) in low-oxygen waters but may be carbon-limited, and (2) continental inputs and dynamic conditions at coastal margins can favor significant N inputs via diazotrophy

Adhesion of Ice in Its Relation to the De-icing of Airplanes

The various possible means of preventing ice adhesion on airplane surfaces are critically reviewed. Results are presented of tests of the adhesives forces between ice and various solid and liquid forces. It is concluded that the de-icing of airplane wings by heat from engine exhaust shows sufficient promise to warrant full-scale tests. For propellers, at least, and possibly for certain small areas such as windshields, radio masts, etc. the use of de-icing or adhesion-preventing liquids will provide the best means of protection

On Two Models of the Light Pulse Delay in a Saturable Absorber

A comparative analysis of two approaches to description of the light modulation pulse delay in a saturable absorber is presented. According to the simplest model, the delay of the optical pulse is a result of distortion of its shape due to absorption self-modulation in the nonlinear medium. The second model of the effect, proposed at the beginning of our century, connects the pulse delay with the so-called "slow light" resulting from the group velocity reduction under conditions of the coherent population oscillations. It is shown that all the known experimental data on the light pulse delay in saturable absorbers can be comprehensively described in the framework of the simplest model of saturable absorber and do not require invoking the effect of coherent population oscillations with spectral hole-burning and anomalous modifications of the light group velocity. It is concluded that the effect of group velocity reduction under conditions of coherent population oscillations has not received so far any experimental confirmation, and the assertions about real observation of the "slow light" based on this mechanism are groundless.Comment: Regretfully, the journal version of the paper (in Optics and Spectroscopy) appeared to be strongly corrupted due to ignorant editing. In particular, "coherent population oscillations" (CPO) was replaced by "population coherent oscillations" (PCO), "bleaching" - by "clearing", and "bleachable absorber " - by "clearable absorber". Here we present original version of the pape

The Impact of Social Media on the Sales Cycle and Prospecting

Sharing information and networking with business contacts are the crux of social media in sales. The use of social media platforms (e.g., LinkedIn, Facebook and Twitter) for all phases of the sales cycle is a relatively new technique, about 20 years since the arrival of the internet and associated technologies. Research to measure the impact of social media on the sales cycle time is not adequately addressed in the current literature. Our research highlights the impacts of social media on this important business function and examines individual performance aspects associated with the use of social media

Report on a collecting trip of the British Myriapod Group to Hungary in 1994

During a collecting trip participated jointly by the members of the British Myriapod Group and by Hungarian experts in 1994, 34 species of millipedes, 14 of centipedes, 8 of woodlice and 73 of spiders were recorded from Hungary. Two records of the millipede species Boreoiulus tenuis (Bigler, 1913) and Styrioiulus styricus (Verhoeff, 1896) were new to the fauna of Hungary

Toward Resolving Disparate Accounts of the Extent and Magnitude of Nitrogen Fixation in the Eastern Tropical South Pacific Oxygen Deficient Zone

Examination of dinitrogen (N2) fixation in the Eastern Tropical South Pacific oxygen deficient zone has raised questions about the range of diazotrophs in the deep sea and their quantitative importance as a source of new nitrogen globally. However, technical considerations in the deployment of stable isotopes in quantifying N2 fixation rates have complicated interpretation of this research. Here, we report the findings of a comprehensive survey of N2 fixation within, above and below the Eastern Tropical South Pacific oxygen deficient zone. N2 fixation rates were measured using a robust 15N tracer method (bubble removal) that accounts for the slow dissolution of N2 gas and calculated using a conservative approach. N2 fixation was only detected in a subset of samples (8 of 125 replicated measurements) collected within suboxic waters (\u3c 20 μmol O2 kg−1) or at the oxycline. Most of these detectable rates were measured at nearshore stations, or where surface productivity was high. These findings support the hypothesis that low oxygen/high organic carbon conditions favor non-cyanobacterial diazotrophs. Nevertheless, this study indicates that N2 fixation is neither widespread nor quantitatively important throughout this region

Fighting Fraud on Faith: Federal Securities Regulation and the Limits of Disclosure

In the past ten years, Congress passed three major reform acts to address two diametrically opposed concerns: It first restrained what it believed was an excess of securities fraud litigation, then responded to an explosion of securities fraud. This Article contends that despite the competing provocations and ambitions of the reforms, they share an unwarranted adherence to the principle of disclosure as the best means to attack market malfeasance: The Article examines the basis for and consequences of that undeserved legislative fidelity. Applying behavioral economics and cultural theory to the recent legislation and its underpinnings, the Article concludes that a resilient faith in the integrity and possibilities of markets has displaced critical examination of market practices. Because Congress resists the more complex and irregular descriptions of markets that behavioral economists provide and instead relies ever more heavily on disclosure, legal models remain far too simple to capture much real world behavior – including the many possible permutations of fraud. This misplaced faith in the preventive power of disclosure impedes efforts to deter, detect and punish securities malfeasance. This Article suggests an alternative. Drawing on skeptical philosophy, it proposes a conceptual framework and practical reforms that avoid extremes and accommodate change. The skeptical approach advocated here acknowledges the benefits of disclosure, but contends that securities regulations also must recognize its limitations. The Article suggests that by questioning its assumptions, broadening its approach, and redirecting its resources toward a more diverse range of regulatory mechanisms, Congress could craft securities regulations that recognize the market’s imperfections and better protect its participants from fraud

Analysis of the Ceramic Sherds from Area C at the Ware Acres Site (41GG31), Gregg County, Texas

The Ware Acres site (41GG31) was discovered by Buddy Calvin Jones in 1951 on an alluvial terrace of Grace Creek, a southern-flowing tributary to the Sabine River in the southwestern part of the city of Longview, Texas. The site is best known for Jones’ discovery and excavation of an eighteenthcentury Caddo burial with an abundance of European trade goods (Jones 1968:21-24). However, Jones also investigated other parts of the site, which contained extensive Caddo habitation deposits, especially one area at the southern part of the site that had Late Caddo Titus phase midden deposits and remnants of house structures. A large assemblage of ceramic sherds were collected from this area, and although Jones (1968:17) indicated that “a complete analysis of them will be given in a later report,” this was never done. This article presents an analysis of these ceramic sherds, primarily to put the ceramic assemblages from from this important East Texas site on record. The stylistic attributes and known ceramic types in the Ware Acres assemblage are also compared to the ceramic assemblage from the Pine Tree Mound site (Fields and Gadus 2012), as the Ware Acres site may be a component of the Pine Tree Mound Titus phase community found in the middle reaches of the Sabine River basin