Investigating the Mixing Efficiencies of Liquid-to-Liquid Chemical Injection Manifolds for Aquatic Invasive Species Management

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Thomas J. Zolper ◽  
Aaron R. Cupp ◽  
David L. Smith

Aquatic invasive species (AIS) have spread throughout the United States via major rivers and tributaries. Locks and dams positioned along affected waterways, specifically lock chambers, are being evaluated as potential management sites to prevent further expansion into new areas. Recent research has shown that infusion of chemicals (e.g., carbon dioxide) into water can block or kill several invasive organisms and could be a viable option at navigational structures such as lock chambers because chemical infusion would not interfere with vessel passage or lock operation. Chemical treatments near lock structures will require large-scale fluid-mechanic systems and significant energy. Mixing must extend to all stagnation regions within a lock structure to prevent the passage of an invasive fish. This work describes the performance of both wall- and floor-based CO2-infused-water to water injection manifolds targeted for lock structures in terms of mixing time, mixing homogeneity, injection efficiency, and operational power requirements. Both systems have strengths and weaknesses so selection recommendations are given for applications such as open systems and closed systems.

2006 ◽  
Vol 35 (1) ◽  
pp. 195-208 ◽  
Author(s):  
Sabrina J. Lovell ◽  
Susan F. Stone ◽  
Linda Fernandez

Invasive species are a growing threat in the United States, causing losses in biodiversity, changes in ecosystems, and impacts on economic enterprises such as agriculture, fisheries, and international trade. The costs of preventing and controlling invasive species are not well understood or documented, but estimates indicate that the costs are quite high. The costs of aquatic invasive species are even less well understood than those for terrestrial species. A systematic approach is needed to develop a consistent method to estimate the national costs of aquatic invasives. This review of the economic literature on aquatic invasive species is the first stage in the development of that estimate. We reviewed over sixty sources and include both empirical papers that present cost estimates as well as theoretical papers on preventing and mitigating the impacts of aquatic invasive species. Species-specific estimates are included for both animals and plants.


2012 ◽  
Vol 48 (2) ◽  
Author(s):  
Stephen Fuller ◽  
Frank Millerd ◽  
Francisco Fraire ◽  
Maria do Carmo Alfonso

The St. Lawrence Seaway links central regions of North America to the Atlantic Ocean via the Great Lakes navigation system. Harmful non-indigenous aquatic invasive species have increasingly been introduced into the Great Lakes largely through the ballast water of inbound ships involved in international commerce. A variety of solutions have been proposed, with some advocating closure of the St. Lawrence Seaway to international shipping. Historically, it was an important artery linking grain surplus regions in Canada and the United States with international markets. However, during the past two decades the Seaway's role has diminished as a grain transport artery. The objective of this paper is to develop an increased understanding of this decline and to offer thoughts regarding the likely reversal of the forces that may have caused it. Analysis indicates declining imports by selected world regions and domestic transportation legislation is central to the decline.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4581 ◽  
Author(s):  
Carlee A. Resh ◽  
Matthew P. Galaska ◽  
Andrew R. Mahon

Background The introduction of northern snakehead (Channa argus; Anabantiformes: Channidae) and their subsequent expansion is one of many problematic biological invasions in the United States. This harmful aquatic invasive species has become established in various parts of the eastern United States, including the Potomac River basin, and has recently become established in the Mississippi River basin in Arkansas. Effective management of C. argus and prevention of its further spread depends upon knowledge of current population structure in the United States. Methods Novel methods for invasive species using whole genomic scans provide unprecedented levels of data, which are able to investigate fine scale differences between and within populations of organisms. In this study, we utilize 2b-RAD genomic sequencing to recover 1,007 single-nucleotide polymorphism (SNP) loci from genomic DNA extracted from 165 C. argus individuals: 147 individuals sampled along the East Coast of the United States and 18 individuals sampled throughout Arkansas. Results Analysis of those SNP loci help to resolve existing population structure and recover five genetically distinct populations of C. argus in the United States. Additionally, information from the SNP loci enable us to begin to calculate the long-term effective population size ranges of this harmful aquatic invasive species. We estimate long-term Ne to be 1,840,000–18,400,000 for the Upper Hudson River basin, 4,537,500–45,375,000 for the Lower Hudson River basin, 3,422,500–34,225,000 for the Potomac River basin, 2,715,000–7,150,000 for Philadelphia, and 2,580,000–25,800,000 for Arkansas populations. Discussion and Conclusions This work provides evidence for the presence of more genetic populations than previously estimated and estimates population size, showing the invasive potential of C. argus in the United States. The valuable information gained from this study will allow effective management of the existing populations to avoid expansion and possibly enable future eradication efforts.


1966 ◽  
Vol 05 (02) ◽  
pp. 67-74 ◽  
Author(s):  
W. I. Lourie ◽  
W. Haenszeland

Quality control of data collected in the United States by the Cancer End Results Program utilizing punchcards prepared by participating registries in accordance with a Uniform Punchcard Code is discussed. Existing arrangements decentralize responsibility for editing and related data processing to the local registries with centralization of tabulating and statistical services in the End Results Section, National Cancer Institute. The most recent deck of punchcards represented over 600,000 cancer patients; approximately 50,000 newly diagnosed cases are added annually.Mechanical editing and inspection of punchcards and field audits are the principal tools for quality control. Mechanical editing of the punchcards includes testing for blank entries and detection of in-admissable or inconsistent codes. Highly improbable codes are subjected to special scrutiny. Field audits include the drawing of a 1-10 percent random sample of punchcards submitted by a registry; the charts are .then reabstracted and recoded by a NCI staff member and differences between the punchcard and the results of independent review are noted.


Author(s):  
Joshua Kotin

This book is a new account of utopian writing. It examines how eight writers—Henry David Thoreau, W. E. B. Du Bois, Osip and Nadezhda Mandel'shtam, Anna Akhmatova, Wallace Stevens, Ezra Pound, and J. H. Prynne—construct utopias of one within and against modernity's two large-scale attempts to harmonize individual and collective interests: liberalism and communism. The book begins in the United States between the buildup to the Civil War and the end of Jim Crow; continues in the Soviet Union between Stalinism and the late Soviet period; and concludes in England and the United States between World War I and the end of the Cold War. In this way it captures how writers from disparate geopolitical contexts resist state and normative power to construct perfect worlds—for themselves alone. The book contributes to debates about literature and politics, presenting innovative arguments about aesthetic difficulty, personal autonomy, and complicity and dissent. It models a new approach to transnational and comparative scholarship, combining original research in English and Russian to illuminate more than a century and a half of literary and political history.


2008 ◽  
Vol 6 (1) ◽  
pp. 31-42 ◽  
Author(s):  
Robyn Matloff ◽  
Angela Lee ◽  
Roland Tang ◽  
Doug Brugge

Despite nearly 12 million Asian Americans living in the United States and continued immigration, this increasingly substantial subpopulation has consistently been left out of national obesity studies. When included in national studies, Chinese-American children have been grouped together with other Asian Americans, Pacific Islanders or simply as “other,” yielding significantly lower rates of overweight and obesity compared to non-Asians. There is a failure to recognize the ethnic diversity of Asian Americans as well as the effect of acculturation. Results from smaller studies of Chinese American youth suggest that they are adopting lifestyles less Chinese and more Americans and that their share of disease burden is growing. We screened 142 children from the waiting room of a community health center that serves primarily recent Chinese immigrants for height, weight and demographic profile. Body Mass Index was calculated and evaluated using CDC growth charts. Overall, 30.1 percent of children were above the 85th we found being male and being born in the U .S. to be statistically significant for BMI > 85th percentile (p=0.039, p=0.001, respectively). Our results suggest that being overweight in this Chinese American immigrant population is associated with being born in the U.S. A change in public policy and framework for research are required to accurately assess the extent of overweight and obesity in Chinese American children. In particular, large scale data should be stratified by age, sex, birthplace and measure of acculturation to identify those at risk and construct tailored interventions.


Author(s):  
Anne Nassauer

This book provides an account of how and why routine interactions break down and how such situational breakdowns lead to protest violence and other types of surprising social outcomes. It takes a close-up look at the dynamic processes of how situations unfold and compares their role to that of motivations, strategies, and other contextual factors. The book discusses factors that can draw us into violent situations and describes how and why we make uncommon individual and collective decisions. Covering different types of surprise outcomes from protest marches and uprisings turning violent to robbers failing to rob a store at gunpoint, it shows how unfolding situations can override our motivations and strategies and how emotions and culture, as well as rational thinking, still play a part in these events. The first chapters study protest violence in Germany and the United States from 1960 until 2010, taking a detailed look at what happens between the start of a protest and the eruption of violence or its peaceful conclusion. They compare the impact of such dynamics to the role of police strategies and culture, protesters’ claims and violent motivations, the black bloc and agents provocateurs. The analysis shows how violence is triggered, what determines its intensity, and which measures can avoid its outbreak. The book explores whether we find similar situational patterns leading to surprising outcomes in other types of small- and large-scale events: uprisings turning violent, such as Ferguson in 2014 and Baltimore in 2015, and failed armed store robberies.


Author(s):  
Geoffrey Jones

This chapter examines the scaling and diffusion of green entrepreneurship between 1980 and the present. It explores how entrepreneurs and business leaders promoted the idea that business and sustainability were compatible. It then examines the rapid growth of organic foods, natural beauty, ecological architecture, and eco-tourism. Green firms sometimes grew to a large scale, such as the retailer Whole Foods Market in the United States. The chapter explores how greater mainstreaming of these businesses resulted in a new set of challenges arising from scaling. Organic food was now transported across large distances causing a negative impact on carbon emissions. More eco-tourism resulted in more air travel and bigger airports. In other industries scaling had a more positive impact. Towns were major polluters, so more ecological buildings had a positive impact.


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