269 research outputs found

    Nomogram for the settling velocity of spheres

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    Of primary importance to many professions is a knowledge of the rate at which a body will fall through a fluid medium. This problem plays an obvious role in the laboratory analysis of sediment, but it is also encountered in such varied fields as meteorology, mining engineering, sanitary engineering, and river hydraulics. The basic problem differs little in these several fields; indeed, many of the latest advances in the subject have resulted from research in still another science -- fluid mechanics

    An Analysis of Sediment Transportation in the Light of Fluid Turbulence

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    Sediment transportation, like many another engineering problem, has long been studied in a purely empirical manner in the attempt to develop useful working rules from a limited supply of measured data. Since formulas for predicting the sediment load of a stream are generally based upon past records for similar types of flow, they can be depended upon to yield satisfactory results only within this range of flow conditions. Nevertheless, any empirical formula is almost certain to be extrapolated far beyond its limit of validity--a procedure leading sooner or later to serious error, for it is practically impossible to obtain and evaluate enough field measurements to establish empirically a truly general transport law

    Highlights in the History of Hydraulics

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    Cavitation and pressure distribution: head forms at zero angle of yaw

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    https://ir.uiowa.edu/uisie/1032/thumbnail.jp

    The distribution of hydraulic energy in weir flow with relation to spillway design

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    Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil and Sanitary Engineering, 1932.MICROFICHE COPY AVAILABLE IN ENGINEERING.Includes bibliographical references (leaves [68]-[69]).by Hunter Rouse.M.S

    Recent Developments and Future Trends in Volunteered Geographic Information Research: The Case of OpenStreetMap

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    User-generated content (UGC) platforms on the Internet have experienced a steep increase in data contributions in recent years. The ubiquitous usage of location-enabled devices, such as smartphones, allows contributors to share their geographic information on a number of selected online portals. The collected information is oftentimes referred to as volunteered geographic information (VGI). One of the most utilized, analyzed and cited VGI-platforms, with an increasing popularity over the past few years, is OpenStreetMap (OSM), whose main goal it is to create a freely available geographic database of the world. This paper presents a comprehensive overview of the latest developments in VGI research, focusing on its collaboratively collected geodata and corresponding contributor patterns. Additionally, trends in the realm of OSM research are discussed, highlighting which aspects need to be investigated more closely in the near future

    A Mendelian Trait for Olfactory Sensitivity Affects Odor Experience and Food Selection

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    SummaryHumans vary in acuity to many odors [1–4], with variation within olfactory receptor (OR) genes contributing to these differences [5–9]. How such variation also affects odor experience and food selection remains uncertain [10], given that such effects occur for taste [11–15]. Here we investigate β-ionone, which shows extreme sensitivity differences [4, 16, 17]. β-ionone is a key aroma in foods and beverages [18–21] and is added to products in order to give a pleasant floral note [22, 23]. Genome-wide and in vitro assays demonstrate rs6591536 as the causal variant for β-ionone odor sensitivity. rs6591536 encodes a N183D substitution in the second extracellular loop of OR5A1 and explains >96% of the observed phenotypic variation, resembling a monogenic Mendelian trait. Individuals carrying genotypes for β-ionone sensitivity can more easily differentiate between food and beverage stimuli with and without added β-ionone. Sensitive individuals typically describe β-ionone in foods and beverages as “fragrant” and “floral,” whereas less-sensitive individuals describe these stimuli differently. rs6591536 genotype also influences emotional associations and explains differences in food and product choices. These studies demonstrate that an OR variant that influences olfactory sensitivity can affect how people experience and respond to foods, beverages, and other products

    Trajan Places: Establishing Identity and Context for the Bosham and Hawkshaw Heads

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    Two damaged, weathered marble portraits, both discovered in the 1780s at opposite ends of Roman Britain, one at Bosham in West Sussex, the other at Hawkshaw in Peeblesshire, are here re-examined and identified as portraits of the emperor Trajan. The Bosham head is interpreted as a post-mortem image of the deified Trajan set up at the margins of Chichester Harbour, probably during the visit to Britain by the emperor Hadrian in the early a.d. 120s. The Hawkshaw portrait of Trajan appears to have been refashioned from a likeness of Domitian and may originally have been part of a monument created to celebrate and commemorate the total conquest of Britain, in the early a.d. 80s, which was decapitated and buried during a period of unrest on the northern frontier

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
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