Improved Understanding of Acid Wormholing in Carbonate Reservoirs Through Laboratory Experiments and Field Measurements

2018 ◽  
Author(s):  
Robert C. Burton ◽  
Manabu Nozaki ◽  
Nola R. Zwarich ◽  
Kenji Furui
Keyword(s):  
Laboratory Experiments ◽  
Field Measurements ◽  
Carbonate Reservoirs

scholarly journals A biogenic secondary organic aerosol source of cirrus ice nucleating particles

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Martin J. Wolf ◽  
Yue Zhang ◽  
Maria A. Zawadowicz ◽  
Megan Goodell ◽  
Karl Froyd ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Secondary Organic Aerosol ◽  
Global Climate ◽  
Compositional Analysis ◽  
Field Measurements ◽  
Organic Aerosol ◽  
Cloud Formation ◽  
Ambient Atmosphere ◽  
Atmospheric Conditions ◽  
Mass Fractions

Abstract Atmospheric ice nucleating particles (INPs) influence global climate by altering cloud formation, lifetime, and precipitation efficiency. The role of secondary organic aerosol (SOA) material as a source of INPs in the ambient atmosphere has not been well defined. Here, we demonstrate the potential for biogenic SOA to activate as depositional INPs in the upper troposphere by combining field measurements with laboratory experiments. Ambient INPs were measured in a remote mountaintop location at –46 °C and an ice supersaturation of 30% with concentrations ranging from 0.1 to 70 L–1. Concentrations of depositional INPs were positively correlated with the mass fractions and loadings of isoprene-derived secondary organic aerosols. Compositional analysis of ice residuals showed that ambient particles with isoprene-derived SOA material can act as depositional ice nuclei. Laboratory experiments further demonstrated the ability of isoprene-derived SOA to nucleate ice under a range of atmospheric conditions. We further show that ambient concentrations of isoprene-derived SOA can be competitive with other INP sources. This demonstrates that isoprene and potentially other biogenically-derived SOA materials could influence cirrus formation and properties.

A Scaling Law for the Urban Heat Island Phenomenon: Deductions From Field Measurements and Comparisons With Existing Results From Laboratory Experiments

2014 ◽  
Author(s):  
Marina K.-A. Neophytou ◽  
Harindra J. S. Fernando ◽  
Ekaterina Batchvarova ◽  
Mats Sandberg ◽  
Jos Lelieveld ◽  
...  
Keyword(s):  
Urban Heat Island ◽  
Laboratory Experiments ◽  
Scaling Law ◽  
Field Measurements ◽  
Capital City ◽  
Mitigation Measures ◽  
Heat Island ◽  
Multi Scale ◽  
Urban Heat ◽  
The Impact

We report results from a multi-scale field experiment conducted in Cyprus in July 2010 in order to investigate the Urban Heat Island (UHI) in Nicosia capital city and its interaction with multi-scale meteorological phenomena taking place in the broader region. Specifically, the results are analysed and interpreted in terms of a non-dimensional/scaling parameter dictating the urban heat island circulation reported from laboratory experiments (Fernando et al, 2010). We find that the field measurements obey the same scaling law during the day, in the absence of any other flow phenomena apart from the urban heating. During the night we find that the deduced non-dimensional value reduces to half (compared to that during the day); this is due to the presence of katabatic winds from Troodos mountains into the urban center of Nicosia and their cooling effect superimposed on diurnal urban heating. Based on this deduction, the impact of various proposed heat island mitigation measures in urban planning can be evaluated.

Leaves as “crackers”, biofilm as “peanut butter”: Exploratory use of stable isotopes as evidence for microbial pathways in detrital food webs

2011 ◽  
Vol 40 (4) ◽  
Author(s):  
Robert France
Keyword(s):  
Energy Source ◽  
Stable Isotopes ◽  
Food Webs ◽  
Laboratory Experiments ◽  
Peanut Butter ◽  
Field Measurements ◽  
Nitrogen Isotope ◽  
Allochthonous Organic Matter ◽  
Stable Nitrogen Isotope ◽  
Microbial Biofilms

AbstractLaboratory experiments have shown benthic macroinvertebrates to be capable of consuming heterotrophic organisms which develop on decomposing terrestrial leaves. Questions remain, however, as to whether these microbial biofilms represent a significant energy source to macroinvertebrates within the natural environment compared to that supplied by leaf substrates themselves. A compilation of literature data on field measurements of stable nitrogen isotope ratios for herbivorous macroinvertebrates suggests that assimilation of microbial biofilms may be the principle means by which allochthonous organic matter enters freshwater detrital food webs.

scholarly journals Measuring variations of δ<sup>18</sup>O and δ<sup>2</sup>H in atmospheric water vapour using laser spectroscopy: an instrument characterisation study

2012 ◽  
Vol 5 (1) ◽  
pp. 1597-1655 ◽  
Author(s):  
F. Aemisegger ◽  
P. Sturm ◽  
P. Graf ◽  
H. Sodemann ◽  
S. Pfahl ◽  
...  
Keyword(s):  
Water Vapour ◽  
Laboratory Experiments ◽  
Water Cycle ◽  
Field Measurements ◽  
Detailed Knowledge ◽  
Spectroscopic Techniques ◽  
Mixing Ratio ◽  
Atmospheric Water ◽  
Uncertainty Estimates ◽  
Laser Spectroscopic

Abstract. Variations of stable water isotopes in water vapour have become measurable at a measurement frequency of about 1 Hz in recent years using novel laser spectroscopic techniques. This enables us to perform continuous measurements for process-based investigations of the atmospheric water cycle at the time scales relevant for synoptic meteorology. An important prerequisite for the interpretation of data from automated field measurements lasting for several weeks or months is a detailed knowledge about instrument properties and the sources of measurement uncertainty. We present here a comprehensive characterisation and comparison study of two commercial laser spectroscopic systems based on cavity ring-down spectroscopy (Picarro) and off-axis integrated cavity output spectroscopy (Los Gatos Research). The uncertainty components of the measurements were first assessed in laboratory experiments, focussing on the effects of (i) water vapour mixing ratio, (ii) measurement stability, (iii) uncertainties due to calibration and (iv) response times of the isotope measurements due to adsorption-desorption processes on the tubing and measurement cavity walls. Based on the experience from our laboratory experiments we set up a one-week field campaign for comparing measurements of the ambient isotope signals of the two laser spectroscopic systems. The optimal calibration strategy determined for both instruments was applied as well as the correction functions for water vapour mixing ratio effects. The root mean square difference between the isotope signals from the two instruments during the field deployment was 2.3‰ for δ2H, 0.5‰ for δ18O and 3.1‰ for deuterium excess. These uncertainty estimates from field measurements compare well to those found in the laboratory experiments. The present quality of measurements from laser spectroscopic instruments combined with a calibration system opens new possibilities for investigating the atmospheric water cycle and the land-atmosphere moisture fluxes.

scholarly journals A NONLINEAR MODEL OF IRREGULAR WAVE RUN-UP HEIGHT A D PERIOD DISTRIBUTIONS ON GENTLE SLOPES

1984 ◽  
Vol 1 (19) ◽  
pp. 29 ◽  
Author(s):  
Toru Sawaragi ◽  
Koichiro Iwata
Keyword(s):  
Nonlinear Model ◽  
Laboratory Experiments ◽  
Sandy Beach ◽  
Probability Distributions ◽  
Field Measurements ◽  
Wave Period ◽  
Irregular Wave ◽  
Long Period ◽  
Proposed Model ◽  
Run Up

This paper discusses the probability distributions of irregular wave run-up height and period on gentle slopes. Assuming that the long period component appeared on the run-up oscillation corresponds to the incident envelope wave period, a nonlinear model to estimate the probability distributions of run-up heights and periods is proposed. Laboratory experiments on gentle slopes of 1/15,1/30 and 1/40, and field measurements on a natural sandy beach with swash slopes of 1/6 to 1/14 were performed to examine the proposed model. The proposed model is shown to agree with the experiments.

scholarly journals Laboratory measurements of stomatal NO<sub>2</sub> deposition to native California trees and the role of forests in the NO<sub><i>x</i></sub> cycle

2020 ◽  
Author(s):  
Erin R. Delaria ◽  
Bryan K. Place ◽  
Amy X. Liu ◽  
Ronald C. Cohen
Keyword(s):  
Laboratory Experiments ◽  
Field Measurements ◽  
Large Degree ◽  
Laboratory Studies ◽  
Laboratory Measurements ◽  
Deposition Fluxes ◽  
Deposition Velocities ◽  
Direct Laser ◽  
Leaf Level

Abstract. Both canopy-level field measurements and laboratory studies suggest that absorption of NO2 through the leaf stomata of vegetation is a significant sink of atmospheric NOx. However, the mechanisms of this foliar NO2 uptake and their impact on NOx lifetimes remains incompletely understood. To understand the leaf-level processes affecting ecosystem scale atmosphere-biosphere NOx exchange, we have conducted laboratory experiments of branch-level NO2 deposition fluxes to six coniferous and four broadleaf native California trees using a branch enclosure system with direct Laser Induced Fluorescence (LIF) detection of NO2. We report NO2 foliar deposition that demonstrates a large degree of inter-species variability, with maximum observed deposition velocities ranging from 0.15–0.51 cm/s during the daytime, as well as significant stomatal opening during the night. We also find that the contribution of mesophyllic processing to the overall deposition rate of NO2 varies by tree species, but has an ultimately inconsequential impact on NOx budgets and lifetimes. Additionally, we find no evidence of any emission of NO2 from leaves, suggesting an effective uni-directional exchange of NOx between the atmosphere and vegetation.

Algae concentrated by frazil ice: evidence from laboratory experiments and field measurements

1989 ◽  
Vol 1 (4) ◽  
pp. 313-316 ◽  
Author(s):  
D.L. Garrison ◽  
A.R. Close ◽  
E. Reimnitz
Keyword(s):  
Laboratory Experiments ◽  
Spatial Scales ◽  
Field Measurements ◽  
Small Scale ◽  
Natural Setting ◽  
Langmuir Circulation ◽  
Frazil Ice ◽  
Laboratory Results ◽  
Temporal And Spatial ◽  
High Concentrations

A number of studies have suggested that high concentrations of organisms in sea ice may be the result of harvesting and concentration by frazil ice. Laboratory experiments have shown that frazil ice can concentrate organisms from two to four times above levels in the underlying water. The concentrations in nature, however, can be considerably higher. The apparent discrepancy between laboratory results and field observations can be explained by the longer temporal and spatial scales that allow more contact of ice crystals with particles and with one another in the sea. It is also likely that small-scale circulation features, such as Langmuir circulation, enhance the ability of frazil ice to concentrate organisms in a natural setting.

Sulphide Metabolism in Thalassinidean Crustacea

1997 ◽  
Vol 77 (1) ◽  
pp. 127-144 ◽  
Author(s):  
A.R. Johns ◽  
A.C. Taylor ◽  
R.J.A. Atkinson ◽  
M.K. Grieshaber
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Laboratory Experiments ◽  
Natural Habitat ◽  
Field Measurements ◽  
Poisoning Effect ◽  
Low Concentrations ◽  
Detoxification Mechanism ◽  
Muddy Sediments ◽  
Callianassa Subterranea

Sulphide occurs widely in marine sediments and is highly toxic to most organisms. Its principal poisoning effect occurs at extremely low concentrations and is the result of inhibition of mitochondrial cytochrome c oxidase. Mud-shrimps (Crustacea: Thalassinidea), construct burrows in sublittoral muddy sediments. The sediment in which they burrow is markedly reduced and conditions within the burrow are usually hypoxic and hypercapnic. Field measurements indicate that the shrimps may be exposed to potentially toxic levels of sulphide in the burrow water (range 0–206 μM, N=37). Laboratory experiments carried out onCalocaris macandreae, Callianassa subterraneaandJaxea nocturnahave shown that these species have a high tolerance of sulphide. An oxygen dependent detoxification mechanism exists to defend cytochrome c oxidase from sulphide poisoning. The main detoxification product of this mechanism is thiosulphate which accumulates rapidly even during brief exposures to low concentrations of sulphide. Sulphite also appears as a secondary detoxification product. Aerobic metabolism can be maintained even under severe hypoxia and toxic sulphide conditions. The mud-shrimps switch to anaerobiosis when the detoxification mechanism is saturated. These data indicate that mud-shrimps are physiologically adapted to tolerate elevated levels of sulphide that they may encounter in their natural habitat.

INDUCED POLARIZATION: A METHOD OF GEOPHYSICAL PROSPECTING

Geophysics ◽  
1953 ◽  
Vol 18 (3) ◽  
pp. 636-661 ◽  
Author(s):  
D. F. Bleil
Keyword(s):  
Laboratory Experiments ◽  
Field Measurements ◽  
Potential Drop ◽  
Induced Polarization ◽  
Polarization Potential ◽  
The Body ◽  
Chemical Action ◽  
Electrically Conducting ◽  
Point Electrode ◽  
Metallic Body

Laboratory experiments have shown certain fundamental relationships concerning the induction of a polarization potential on a metallic body in an electrolyte. The potential induced is a linear function of the potential drop across the body in the energizing field up to a saturation potential of 1.2 volts. Diffusion of ions and chemical action are the predominant factors which determine the rate of growth or decay of the polarization potential. Polarization occurs only at the boundaries of electrically conducting minerals. The results of the laboratory experiments provide an explanation of the induced polarization potential of a homogeneous, uniformly mineralized earth. This potential falls off as 1/r from a point electrode. Induced polarization susceptibility is defined and a method of analyzing field data is described. Field measurements over two mineralized zones (pyrrhotite and magnetite) substantiate the theory as developed.

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