Influence of organic particle addition on nitrification rates and ammonium oxidiser abundances in Baltic seawater

2021 ◽  
Author(s):  
S Kache ◽  
I Bartl ◽  
J Wäge-Recchioni ◽  
M Voss
Keyword(s):  
Particle Addition ◽  
Organic Particle

Effect of TiB2 particle addition on the mechanical properties of Al/TiB2 in situ formed metal matrix composites

2018 ◽  
Vol 60 (12) ◽  
pp. 1221-1224 ◽  
Author(s):  
Balachandran Gobalakrishnan ◽  
P. Ramadoss Lakshminarayanan ◽  
Raju Varahamoorthi
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Tib2 Particle ◽  
Matrix Composites ◽  
Particle Addition

scholarly journals Zooplankton grazing of microplastic can accelerate global loss of ocean oxygen

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
K. Kvale ◽  
A. E. F. Prowe ◽  
C.-T. Chien ◽  
A. Landolfi ◽  
A. Oschlies
Keyword(s):  
North Pacific ◽  
Grazing Pressure ◽  
System Model ◽  
Earth System ◽  
Primary Producers ◽  
Climate Research ◽  
The North ◽  
Zooplankton Consumption ◽  
The North Pacific ◽  
Organic Particle

AbstractGlobal warming has driven a loss of dissolved oxygen in the ocean in recent decades. We demonstrate the potential for an additional anthropogenic driver of deoxygenation, in which zooplankton consumption of microplastic reduces the grazing on primary producers. In regions where primary production is not limited by macronutrient availability, the reduction of grazing pressure on primary producers causes export production to increase. Consequently, organic particle remineralisation in these regions increases. Employing a comprehensive Earth system model of intermediate complexity, we estimate this additional remineralisation could decrease water column oxygen inventory by as much as 10% in the North Pacific and accelerate global oxygen inventory loss by an extra 0.2–0.5% relative to 1960 values by the year 2020. Although significant uncertainty accompanies these estimates, the potential for physical pollution to have a globally significant biogeochemical signal that exacerbates the consequences of climate warming is a novel feedback not yet considered in climate research.

scholarly journals Determining Functional Relations in Multivariate Oceanographic Systems: Model II Multiple Linear Regression

2014 ◽  
Vol 31 (7) ◽  
pp. 1663-1672 ◽  
Author(s):  
Scott J. Richter ◽  
Robert H. Stavn
Keyword(s):  
Cross Section ◽  
Particle Concentration ◽  
Scattering Coefficient ◽  
Mineral Particle ◽  
Particle Scattering ◽  
Multivariate System ◽  
Functional Relationships ◽  
Scattering Cross ◽  
Model Ii Regression ◽  
Organic Particle

Abstract A method for estimating multivariate functional relationships between sets of measured oceanographic, meteorological, and other field data is presented. Model II regression is well known for describing functional relationships between two variables. However, there is little accessible guidance for the researcher wishing to apply model II methods to a multivariate system consisting of three or more variables. This paper describes a straightforward method to extend model II regression to the case of three or more variables. The multiple model II procedure is applied to an analysis of the optical spectral scattering coefficient measured in the coastal ocean. The spectral scattering coefficient is regressed against both suspended mineral particle concentration and suspended organic particle concentration. The regression coefficients from this analysis provide adjusted estimates of the mineral particle scattering cross section and the organic particle scattering cross section. Greater accuracy and efficiency of the coefficients from this analysis, compared to semiempirical coefficients, is demonstrated. Examples of multivariate data are presented that have been analyzed by partitioning the variables into arbitrary bivariate models. However, in a true multivariate system with correlated predictors, such as a coupled biogeochemical cycle, these bivariate analyses yield incorrect coefficient estimates and may result in large unexplained variance. Employing instead a multivariate model II analysis can alleviate these problems and may be a better choice in these situations.

scholarly journals Temperature-dependent accumulation mode particle and cloud nuclei concentrations from biogenic sources during WACS 2010

2012 ◽  
Vol 12 (10) ◽  
pp. 27989-28031 ◽  
Author(s):  
L. Ahlm ◽  
K. M. Shakya ◽  
L. M. Russel ◽  
J. C. Schroder ◽  
J. P. S. Wong ◽  
...  
Keyword(s):  
Cloud Condensation Nuclei ◽  
Number Concentration ◽  
Particle Mass ◽  
Strongly Correlated ◽  
Submicron Particle ◽  
Temperature Dependent ◽  
Volatile Organic ◽  
Mountain Site ◽  
Condensational Growth ◽  
Organic Particle

Abstract. Submicron aerosol particles collected simultaneously at the mountain peak (2182 m a.s.l.) and at a forested mid-mountain site (1300 m a.s.l.) on Whistler Mountain, British Columbia, Canada, during June and July 2010 were analyzed by Fourier transform infrared (FTIR) spectroscopy for quantification of organic functional groups. Positive matrix factorization (PMF) was applied to the FTIR spectra. Three PMF factors associated with (1) combustion, (2) biogenics, and (3) vegetative detritus, were identified at both sites. The biogenic factor was correlated with both temperature and several volatile organic compounds (VOCs). The combustion factor dominated the submicron particle mass during the beginning of the campaign when the temperature was lower and advection was from the Vancouver area, but as the temperature started to rise in early July the biogenic factor came to dominate as a result of increased emissions of biogenic VOCs and thereby increased formation of secondary organic aerosol (SOA). On average, the biogenic factor represented 69% and 49% of the submicron organic particle mass at Whistler Peak and at the mid-mountain site, respectively. The lower fraction at the mid-mountain site was a result of more vegetative detritus there, and also higher influence from local combustion sources. The biogenic factor was strongly correlated (r ~ 0.9) to number concentration of particles with diameter (Dp)> 100 nm, whereas the combustion factor was better correlated to number concentration of particles with Dp < 100 nm (r~ 0.4). The number concentration of cloud condensation nuclei (CCN) was correlated (r ~ 0.7) to the biogenic factor for supersaturations (S) of 0.2% or higher, which indicates that particle condensational growth from biogenic vapors was an important factor in controlling the CCN concentration for clouds where S≥0.2%. Both the number concentration of particles with Dp > 100 nm and numbers of CCN for S≥0.2% were correlated to temperature. Considering the biogenic influence, these results indicate that temperature was a primary factor controlling these CCN concentrations at 0.2% supersaturation.

Nano- Al2O3 particle addition effects on Y Ba2Cu3Oy superconducting properties

2006 ◽  
Vol 140 (6) ◽  
pp. 318-323 ◽  
Author(s):  
A. Mellekh ◽  
M. Zouaoui ◽  
F. Ben Azzouz ◽  
M. Annabi ◽  
M. Ben Salem
Keyword(s):  
Al2o3 Particle ◽  
Superconducting Properties ◽  
Particle Addition

Composition and Sources of the Organic Particle Emissions from Aircraft Engines

2013 ◽  
Vol 48 (1) ◽  
pp. 61-73 ◽  
Author(s):  
Michael T. Timko ◽  
Simon E. Albo ◽  
Timothy B. Onasch ◽  
Edward C. Fortner ◽  
Zhenhong Yu ◽  
...  
Keyword(s):  
Aircraft Engines ◽  
Particle Emissions ◽  
Organic Particle

Effect of Water Temperature on Interfacial Shear Strength of Resin Particles Added CFRTP

2018 ◽  
Vol 774 ◽  
pp. 7-12
Author(s):  
Hideaki Katogi ◽  
Kenichi Takemura ◽  
Mao Mochizuki
Keyword(s):  
Shear Strength ◽  
Carbon Fiber ◽  
Water Temperature ◽  
Room Temperature ◽  
Interfacial Shear Strength ◽  
Water Immersion ◽  
Interfacial Shear ◽  
Water Penetration ◽  
Resin Particle ◽  
Particle Addition

In this study, interfacial shear strength of resin particles added carbon fiber/maleic acid anhydride grafted polypropylene under water temperature was investigated. Water temperature range was from room temperature to 80 oC. The maximum immersion time was 24 hours. Micro debonding tests of non and resin particles added composites were conducted. Fracture surface of resin particles added composite were observed by Scanning Electron Microscope (SEM). As a result, interfacial shear strengths of non particles added composite monotonously decreased with an increase of water temperature. Interfacial shear strength of resin particles added composite was higher than that of non resin particles added composite under all water temperatures except for 50 oC. From SEM observation, large resin particles on surface of carbon fiber after water immersion at 50 oC were found. And, many matrices and large resin particles on surface of carbon fiber after water immersion at 80 oC were found. Therefore, interfacial shear strength of composite was improved because resin particle addition prevented water penetration into the interface between fiber and matrix under water immersion less than 50 oC. And, interfacial shear strength of composite was probably improved by anchor effect of resin particle under water immersion at 80 oC.

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