Tara Pacific Expedition’s Atmospheric Measurements of Marine Aerosols across the Atlantic and Pacific Oceans: Overview and Preliminary Results

Abstract Marine aerosols play a significant role in the global radiative budget, in clouds’ processes, and in the chemistry of the marine atmosphere. There is a critical need to better understand their production mechanisms, composition, chemical properties, and the contribution of ocean-derived biogenic matter to their mass and number concentration. Here we present an overview of a new dataset of in situ measurements of marine aerosols conducted over the 2.5-yr Tara Pacific Expedition over 110,000 km across the Atlantic and Pacific Oceans. Preliminary results are presented here to describe the new dataset that will be built using this novel set of measurements. It will characterize marine aerosols properties in detail and will open a new window to study the marine aerosol link to the water properties and environmental conditions.

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Measuring Radon and Thoron Levels in Sri Lanka

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.718-720.721 ◽

2013 ◽

Vol 718-720 ◽

pp. 721-724

Author(s):

Deepal Subasinghe Nalaka ◽

Mahakumara Prasad ◽

Thusitha B. Nimalsiri ◽

Nuwan B. Suriyaarchchi ◽

Takeshi Iimoto ◽

...

Keyword(s):

Sri Lanka ◽

Environmental Conditions ◽

In Situ Measurements ◽

Physical Factors ◽

Preliminary Results ◽

Radon Measurements ◽

First Time

For the first time in Sri Lanka, an attempt was made to measure the outdoor radon levels using CR 39 type passive radon detectors. Preliminary results indicate that in Sri Lanka, 220Rn isotope is more abundance than 222Rn isotope. These results were also confirmed by in-situ measurements. Sri Lanka has one of the highest 220Rn values in the region. It was also noted that environmental conditions and other physical factors have a significant effect on the outdoor radon measurements using passive discriminative detectors.

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Evaluation of the global oceanic isoprene source and its impacts on marine organic carbon aerosol

Atmospheric Chemistry and Physics ◽

10.5194/acp-9-1253-2009 ◽

2009 ◽

Vol 9 (4) ◽

pp. 1253-1262 ◽

Cited By ~ 129

Author(s):

S. R. Arnold ◽

D. V. Spracklen ◽

J. Williams ◽

N. Yassaa ◽

J. Sciare ◽

...

Keyword(s):

Organic Carbon ◽

Scale Up ◽

Organic Aerosol ◽

Marine Atmosphere ◽

Aerosol Mass ◽

Phytoplankton Communities ◽

The Mean ◽

Global Oceans ◽

Production Mechanisms

Abstract. We have combined the first satellite maps of the global distribution of phytoplankton functional type and new measurements of phytoplankton-specific isoprene productivities, with available remote marine isoprene observations and a global model, to evaluate our understanding of the marine isoprene source and its impacts on organic aerosol abundances. Using satellite products to scale up data on phytoplankton-specific isoprene productivity to the global oceans, we infer a mean "bottom-up" oceanic isoprene emission of 0.31±0.08 (1σ) Tg/yr. By minimising the mean bias between the model and isoprene observations in the marine atmosphere remote from the continents, we produce a "top-down" oceanic isoprene source estimate of 1.9 Tg/yr. We suggest our reliance on limited atmospheric isoprene data, difficulties in simulating in-situ isoprene production rates in laboratory phytoplankton cultures, and limited knowledge of isoprene production mechanisms across the broad range of phytoplankton communities in the oceans under different environmental conditions as contributors to this difference between the two estimates. Inclusion of secondary organic aerosol (SOA) production from oceanic isoprene in the model with a 2% yield produces small contributions (0.01–1.4%) to observed organic carbon (OC) aerosol mass at three remote marine sites in the Northern and Southern Hemispheres. Based on these findings we suggest an insignificant role for isoprene in modulating remote marine aerosol abundances, giving further support to a recently postulated primary OC source in the remote marine atmosphere.

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Cathodoluminescence of Catalyst Crystallites

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100055667 ◽

1982 ◽

Vol 40 ◽

pp. 664-665

Author(s):

E.D. Boyes ◽

P.L. Gai ◽

D.B. Darby ◽

C. Warwick

Keyword(s):

Defect Density ◽

Chemical Properties ◽

Operating Conditions ◽

Semiconductor Materials ◽

Environmental Cell ◽

High Resolution Structure ◽

Commercially Important ◽

Crystallographic Defects ◽

Resolution Structure

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.

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Enhanced Tensile Strength of Monolithic Epoxy with Highly Dispersed TiO2-Graphene Nanocomposites

Journal of Composites Science ◽

10.3390/jcs5070191 ◽

2021 ◽

Vol 5 (7) ◽

pp. 191

Author(s):

Yanshuai Wang ◽

Siyao Guo ◽

Biqin Dong ◽

Feng Xing

Keyword(s):

Tensile Strength ◽

Epoxy Resin ◽

Mechanical Performance ◽

Chemical Properties ◽

High Mechanical Property ◽

Graphene Nanocomposites ◽

Highly Dispersed ◽

Dispersion State ◽

Physical And Chemical

The functionalization of graphene has been reported widely, showing special physical and chemical properties. However, due to the lack of surface functional groups, the poor dispersibility of graphene in solvents strongly limits its engineering applications. This paper develops a novel green “in-situ titania intercalation” method to prepare a highly dispersed graphene, which is enabled by the generation of the titania precursor between the layer of graphene at room temperature to yield titania-graphene nanocomposites (TiO2-RGO). The precursor of titania will produce amounts of nano titania between the graphene interlayers, which can effectively resist the interfacial van der Waals force of the interlamination in graphene for improved dispersion state. Such highly dispersed TiO2-RGO nanocomposites were used to modify epoxy resin. Surprisingly, significant enhancement of the mechanical performance of epoxy resin was observed when incorporating the titania-graphene nanocomposites, especially the improvements in tensile strength and elongation at break, with 75.54% and 176.61% increases at optimal usage compared to the pure epoxy, respectively. The approach presented herein is easy and economical for industry production, which can be potentially applied to the research of high mechanical property graphene/epoxy composite system.

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In situ dual crosslinking strategy to improve the physico-chemical properties of thermoplastic starch

Carbohydrate Polymers ◽

10.1016/j.carbpol.2021.118250 ◽

2021 ◽

pp. 118250

Author(s):

Hamed Peidayesh ◽

Abolfazl Heydari ◽

Katarína Mosnáčková ◽

Ivan Chodák

Keyword(s):

Chemical Properties ◽

Thermoplastic Starch ◽

Physico Chemical

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MixAR

Journal of Information Technology Research ◽

10.4018/jitr.2019100101 ◽

2019 ◽

Vol 12 (4) ◽

pp. 1-33 ◽

Cited By ~ 1

Author(s):

Telmo Adão ◽

Luís Pádua ◽

David Narciso ◽

Joaquim João Sousa ◽

Luís Agrellos ◽

...

Keyword(s):

Environmental Conditions ◽

Mixed Reality ◽

The Real ◽

Points Of Interest ◽

Real Scene ◽

The Future

MixAR, a full-stack system capable of providing visualization of virtual reconstructions seamlessly integrated in the real scene (e.g. upon ruins), with the possibility of being freely explored by visitors, in situ, is presented in this article. In addition to its ability to operate with several tracking approaches to be able to deal with a wide variety of environmental conditions, MixAR system also implements an extended environment feature that provides visitors with an insight on surrounding points-of-interest for visitation during mixed reality experiences (positional rough tracking). A procedural modelling tool mainstreams augmentation models production. Tests carried out with participants to ascertain comfort, satisfaction and presence/immersion based on an in-field MR experience and respective results are also presented. Ease to adapt to the experience, desire to see the system in museums and a raised curiosity and motivation contributed as positive points for evaluation. In what regards to sickness and comfort, the lowest number of complaints seems to be satisfactory. Models' illumination/re-lightning must be addressed in the future to improve the user's engagement with the experiences provided by the MixAR system.

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In-Situ Cosmogenic 14C: Production and Examples of its Unique Applications in Studies of Terrestrial and Extraterrestrial Processes

Radiocarbon ◽

10.1017/s0033822200041394 ◽

2001 ◽

Vol 43 (2B) ◽

pp. 731-742 ◽

Cited By ~ 8

Author(s):

D Lal ◽

A J T Jull

Keyword(s):

Half Life ◽

Earth Science ◽

Chemical Properties ◽

Radioactive Isotopes ◽

Earth’S Atmosphere ◽

The Earth ◽

Wide Range ◽

History Of ◽

Earth's Atmosphere

Nuclear interactions of cosmic rays produce a number of stable and radioactive isotopes on the earth (Lai and Peters 1967). Two of these, 14C and 10Be, find applications as tracers in a wide variety of earth science problems by virtue of their special combination of attributes: 1) their source functions, 2) their half-lives, and 3) their chemical properties. The radioisotope, 14C (half-life = 5730 yr) produced in the earth's atmosphere was the first to be discovered (Anderson et al. 1947; Libby 1952). The next longer-lived isotope, also produced in the earth's atmosphere, 10Be (half-life = 1.5 myr) was discovered independently by two groups within a decade (Arnold 1956; Goel et al. 1957; Lal 1991a). Both the isotopes are produced efficiently in the earth's atmosphere, and also in solids on the earth's surface. Independently and jointly they serve as useful tracers for characterizing the evolutionary history of a wide range of materials and artifacts. Here, we specifically focus on the production of 14C in terrestrial solids, designated as in-situ-produced 14C (to differentiate it from atmospheric 14C, initially produced in the atmosphere). We also illustrate the application to several earth science problems. This is a relatively new area of investigations, using 14C as a tracer, which was made possible by the development of accelerator mass spectrometry (AMS). The availability of the in-situ 14C variety has enormously enhanced the overall scope of 14C as a tracer (singly or together with in-situ-produced 10Be), which eminently qualifies it as a unique tracer for studying earth sciences.

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Accurate dating of stalagmites from low seasonal contrast tropical Pacific climate using Sr 2D maps, fabrics and annual hydrological cycles

Scientific Reports ◽

10.1038/s41598-021-81941-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Mohammadali Faraji ◽

Andrea Borsato ◽

Silvia Frisia ◽

John C. Hellstrom ◽

Andrew Lorrey ◽

...

Keyword(s):

Principal Component ◽

Tropical Pacific ◽

In Situ Monitoring ◽

Marine Aerosols ◽

Icp Ms ◽

Optical Maps ◽

Hydrological Cycles ◽

Climate Proxies ◽

Dimensional Mapping

AbstractTropical Pacific stalagmites are commonly affected by dating uncertainties because of their low U concentration and/or elevated initial 230Th content. This poses problems in establishing reliable trends and periodicities for droughts and pluvial episodes in a region vulnerable to climate change. Here we constrain the chronology of a Cook Islands stalagmite using synchrotron µXRF two-dimensional mapping of Sr concentrations coupled with growth laminae optical imaging constrained by in situ monitoring. Unidimensional LA-ICP-MS-generated Mg, Sr, Ba and Na variability series were anchored to the 2D Sr and optical maps. The annual hydrological significance of Mg, Sr, Ba and Na was tested by principal component analysis, which revealed that Mg and Na are related to dry-season, wind-transported marine aerosols, similar to the host-rock derived Sr and Ba signatures. Trace element annual banding was then used to generate a calendar-year master chronology with a dating uncertainty maximum of ± 15 years over 336 years. Our approach demonstrates that accurate chronologies and coupled hydroclimate proxies can be obtained from speleothems formed in tropical settings where low seasonality and problematic U–Th dating would discourage the use of high-resolution climate proxies datasets.

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