1,720,961 research outputs found
Dataset for research article: New capability in autonomous ocean carbon observations using the Autosub Long-Range AUV equipped with novel pH and Total Alkalinity sensors
No full textDataset supports: Hammermeister et al. New capability in autonomous ocean carbon observations using the Autosub Long-Range AUV equipped with novel pH and Total Alkalinity sensors Environmental Science & Technology 2025</span
Evaluation of linear displacement technologies suitable for monitoring the position of the pumps in sensors
No full textHet National Oceanography Centre in Southampton (Verenigd Koninkrijk) ontwikkelt sensoren voor oceaanonderzoek. Eén van hun sensoren is de 'wet chemical sensor', een sensor met een chemisch lab. De sensor gebruikt meerdere cilinders om het gesampelde water op te nemen en te mixen met een chemisch reagens in microkanalen. Dit mengsel wordt achteraf gemeten. In het huidige ontwerp van de pomp kunnen de zuigers van de cilinders niet afzonderlijk bewegen, wat er voor zorgt dat de pomp niet efficiënt is. Een beter design zou afzonderlijke pompen moeten bevatten. Dat levert ook het voordeel dat de verhouding van het mengsel gewijzigd kan worden.
Het probleem bij het gebruik van afzonderlijke pompsystemen is dat de verhouding van de verplaatsing kan variëren. Daarom is het noodzakelijk om de positie van iedere zuiger nauwkeurig te meten zodat dit gemonitord kan worden door de software. Daarom zijn verschillende meetmethoden onderzocht om achteraf de pompen te synchroniseren.
Deze mogelijke methoden rusten op capacitieve, inductieve, optische en mechanische theorieën. De capacitieve methode is gebaseerd op de werking van de digitale schuifmaat. Om de werking hiervan te achterhalen, is deze gebackengineerd. De andere methoden vereisten geen backengineering omdat die beter gedocumenteerd of minder complex waren. De eerste methoden ondergingen een cyclus van testen en verbeteren met behulp van een praktische opstelling of een Matlab-model.
Enkel de inductieve meetmethode voldoet aan de vereisten en kan de precisie van 3.1 µm bereiken
New capability in autonomous ocean carbon observations using the Autosub Long-Range AUV equipped with novel pH and total alkalinity sensors
Full text linkThe development of marine autonomous platforms has improved our capability to gather ocean observations at fine spatial scales and high temporal frequency, which can be used to better measure, characterize, and model ocean carbon. As part of the OCEANIDS program, novel carbonate sensors were integrated into the Autosub Long-Range (ALR) autonomous underwater vehicle (AUV) and deployed in the Celtic Sea. Autonomous Lab-On-Chip (LOC) sensors measured pH and total alkalinity (TA) while onboard the ALR. Using interpolation, the ALR-sensor data set is compared against CTD co-samples. The average differences between the LOC sensor and co-sample pH range from −0.011 to −0.015. The TA sensor data agrees with co-samples within 1–2 μmol kg–1 on average. Biogeochemical water properties differing between CTD and ALR observations reveal correlations to carbonate parameter variations. The LOC sensors enabled the characterization of the marine carbonate system from autonomous subsurface measurements for the first time. Sensor pH and TA data were used to calculate dissolved inorganic carbon (DIC), partial pressure of CO2 (pCO2), and aragonite saturation state (ΩAr) and are compared with CTD co-samples with mean residuals of 4–7 μmol kg–1, 10–17 μatm, and −0.03 to −0.06, respectively. Future perspectives on sensor deployment and analysis are discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dataset for research article: Metabolic Dynamics of an Offshore Coral Reef in the Red Sea: Observations from Autonomous Sensors
No full textDataset supports: Hammermeister et al. Metabolic Dynamics of an Offshore Coral Reef in the Red Sea: Observations from Autonomous Sensors</span
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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