Influence of stearic acid coating of the NaCl surface on the reactivity with NO2 under humidity

2015 ◽  
Vol 17 (16) ◽  
pp. 10963-10977 ◽  
Author(s):  
S. Sobanska ◽  
J. Barbillat ◽  
M. Moreau ◽  
N. Nuns ◽  
I. De Waele ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Nitrogen Oxides ◽  
Stearic Acid ◽  
Sea Salt ◽  
Heterogeneous Chemistry ◽  
Atmospheric Nitrogen ◽  
Sea Salt Aerosols ◽  
Acid Coating

In the atmosphere, sea salt aerosols, containing mainly NaCl, can accumulate fatty acids on surface and undergo spatially heterogeneous chemistry with atmospheric nitrogen oxides.

scholarly journals The effect of low solublility organic acids on the hygroscopicity of sodium halide aerosols

2014 ◽  
Vol 14 (4) ◽  
pp. 4383-4419
Author(s):  
L. Miñambres ◽  
E. Méndez ◽  
M. N. Sánchez ◽  
F. Castaño ◽  
F. J. Basterretxea
Keyword(s):  
Organic Acids ◽  
Lauric Acid ◽  
Flow Cell ◽  
Sea Salt ◽  
Sem Images ◽  
Sea Salt Aerosols ◽  
Hygroscopic Properties ◽  
Small Clusters ◽  
Halide Salts ◽  
Acid Coating

Abstract. In order to accurately assess the influence of fatty acids on the hygroscopic and other physicochemical properties of sea salt aerosols, hexanoic, octanoic or lauric acid together with sodium halide salts (NaCl, NaBr and NaI) have been chosen to be performed in this study. The hygroscopic properties of sodium halide submicrometer particles covered with organic acids have been examined by Fourier-transform infrared spectroscopy in an aerosol flow cell. Covered particles were generated by flowing atomized sodium halide particles (either dry or aqueous) through a heated oven containing the gaseous acid. The obtained results indicate that gaseous organic acids easily nucleate onto dry and aqueous sodium halide particles. On the other hand, Scanning Electron Microscopy (SEM) images indicate that lauric acid coating on NaCl particles makes them to aggregate in small clusters. The hygroscopic behaviour of covered sodium halide particles in deliquescence mode shows different features with the exchange of the halide ion: whereas the organic covering has little effect in NaBr particles, NaCl and NaI covered particles change their deliquescence relative humidities, with different trends observed for each of the acids studied. In efflorescence mode, the overall effect of the organic covering is to retard the loss of water in the particles. It has been observed that the presence of gaseous water in heterogeneously nucleated particles tends to displace the cover of hexanoic acid to energetically stabilize the system.

scholarly journals Impact of the particle mixing state on the hygroscopicity of internally mixed sodium chloride-ammonium sulfate single droplets: A theoretical and experimental study

2021 ◽  
Author(s):  
Yeny A. Tobon ◽  
Danielle El Hajj ◽  
Samantha Seng ◽  
Ferdaous Bengrad ◽  
Myriam Moreau ◽  
...  
Keyword(s):  
Experimental Study ◽  
Sodium Chloride ◽  
Ammonium Sulfate ◽  
Atmospheric Transport ◽  
Sea Salt ◽  
Main Constituent ◽  
Sea Salt Aerosols ◽  
Particle Mixing ◽  
Secondary Aerosols ◽  
Single Droplets

Sodium chloride (NaCl) is the main constituent of sea-salt aerosols. During atmospheric transport, sea-salt aerosols can interact with gases and other particles including secondary aerosols containing ammonium sulfate ((NH4)2SO4). This...

Depot fatty acids of Aberdeen Angus and Friesian cattle reared on hay and barley diets

1977 ◽  
Vol 89 (3) ◽  
pp. 575-582 ◽  
Author(s):  
W. M. F. Leat
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Stearic Acid ◽  
Acid Composition ◽  
Visual Inspection ◽  
Subcutaneous Fat ◽  
Octadecenoic Acid ◽  
Hexadecenoic Acid ◽  
Friesian Cattle

SummaryAberdeen Angus and Friesian cattle were reared from 4 months of age to slaughter weight at 18–24 months on either high-barley or high-hay diets. Samples of subcutaneous fat were taken by biopsy at 3 monthly intervals, and the degree of fatness of each animal was estimated ultrasonically prior to slaughter, and by visual inspection of the carcasses.The barley-fed animals gained weight more rapidly, and fattened more quickly than the hay-fed animals with the Angus being fatter than the Friesian at the same age. The percentage stearic acid (C18:0) in subcutaneous fat decreased with age and was replaced by octadecenoic acid (C18:l) and hexadecenoic acid (C16:l), these changes being more rapid in barley-fed than in hay-fed animals. At the same degree of fatness the depot fats of the Friesians were more unsaturated than those of the Angus, and in both breeds the fatter the animal the more unsaturated was its depot fat.In the hay-fed cattle the percentage C16:0 in subcutaneous fat increased during the last half of the experiment and at slaughter the percentage C16:0 was significantly higher, and C18:l significantly lower, in all depot fats compared with those of the barley-fed animals.It is concluded that the fatty acid composition of bovine depot fats is modulated by the degree of fattening, and can be affected by diet.

scholarly journals The absorption of stearic acid from triacylglycerols: an inquiry and analysis

2000 ◽  
Vol 13 (2) ◽  
pp. 185-214 ◽  
Author(s):  
Geoffrey Livesey
Keyword(s):  
Fatty Acids ◽  
Body Weight ◽  
Melting Point ◽  
Cocoa Butter ◽  
Stearic Acid ◽  
Short Chain ◽  
Apparent Digestibility ◽  
Long Chain Fatty Acids ◽  
Long Chain ◽  
Chain Fatty Acids

AbstractAlthough stearic acid is a saturated fatty acid, its influence on plasma cholesterol acid other health variables is neutral; possibly owing in part to poor absorption. Reduced absorption of stearic acid from particular triacylglycerols, cocoa butter and novel fats formulated with short- and long-chain acid triacylglycerol molecules (Salatrims) has been attributed to high intakes. However, the circumstances and causes of poor stearic acid digestion from triacylglycerols are unclear; published data were therefore collected and analysed, with emphasis on human studies. Of twenty-eight studies conducted in adults, most are in men (>90%). The assertion that reduced absorption is due to a high intake of stearoyl groups is not supported: dietary intakes of stearoyl of 0·05–0·65 g stearic acid equivalent/kg body weight (cf typical intake of 0·2 g stearic acid equivalent/kg body weight in the Western diet) indicate that the ‘true’ digestibility of stearoyl is 0·98 (SE 0·01) g/g, with apparent digestibility less than this value at low intakes owing to endogenous stearic acid excretion and to inter-publication variation of unidentified cause. The neutral health impact of stearic acid must be due to factors other than availability. Exceptions include cocoa butter, Salatrims and tristearin, for which digestibility is an additional factor. The efficiency with which human subjects digest stearoyl from cocoa butter still remains uncertain, while the digestion of total long-chain fat from this source is 0·89–0·95 g/g, high in comparison with 0·33 g/g for Salatrim 23CA and 0·15 g/g for tristearin in their prepared states. Salatrims contain the highest proportion of long-chain fatty acids that are stearic acid-rich other than tristearin, which is the main component of fully-hydrogenated soyabean and rapeseed oil. Analysis shows that apparent digestibility of stearic acid is associated with stearoyl density within the triacylglycerol molecule and that, in Salatrims, the occurrence of short-chain fatty acids in place of long-chain fatty acids increases this density. Soap formation appears not to be a major factor in the reduced digestion of stearic acid from tristearin under regular dietary circumstances, but both microcrystallinity and reduced digestibility of tri-, di- and monostearoylglycerols appears to be important. Solubilisation of high-melting-point tristearin in low-melting-point oils improves the digestibility of its stearic acid, particularly when emulsified or liquidized at above melting point. However, without such artificial aids, the digestive tracts of the rat, dog and man have a low capacity for emulsifying and digesting stearic acid from tristearin. Reduced digestibility of stearic acid from Salatrim 23CA also appears to be attributable to reduced digestibility of di- and monostearoylglycerols and is particularly due to remnants with the 1- or 3-stearoylglycerol intact after initial hydrolytic cleavage. Short-chain organic acid in Salatrim 23CA, which is readily hydrolysed, leaves such remnants. Unlike tristearin, Salatrim 23CA melts at body temperature and mixing it with low-melting-point oils is not expected to cause further disruption of microcrystalline structures to aid digestibility of its stearoyl groups. The low digestibility of stearoyl in Salatrim 23CA, together with the occurrence of short-chain organic acids in this product, account for its relatively low nutritional energy value (about 20 kJ (5 kcal)/g) compared with traditional fats (37 kJ (9 kcal)/g) and low fat value (<20:37 kJ/kJ; <5:9 kcal/kcal) relative to traditional fats. In part these differences are because of minor effects of Salatrim 23CA on the excretion of other fat and protein, due to the bulking properties of this poorly-digestible fat.

The Inhomogeneity Effect of Sea Salt Aerosols on the TOA Polarized Radiance at the Scattering Angles Ranging From 170° to 175°

2021 ◽  
pp. 1-12
Author(s):  
Meng Li ◽  
Lei Bi ◽  
Wushao Lin ◽  
Fuzhong Weng ◽  
Shuangyan He ◽  
...  
Keyword(s):  
Sea Salt ◽  
Sea Salt Aerosols

scholarly journals Aerosol distribution around Svalbard during intense easterly winds

2010 ◽  
Vol 10 (4) ◽  
pp. 1473-1490 ◽  
Author(s):  
A. Dörnbrack ◽  
I. S. Stachlewska ◽  
C. Ritter ◽  
R. Neuber
Keyword(s):  
Sea Salt ◽  
Airborne Lidar ◽  
The Arctic ◽  
Aerosol Layer ◽  
Atmospheric Conditions ◽  
Sea Salt Aerosols ◽  
Aerosol Distribution ◽  
Weather Situation ◽  
Low Level Jet ◽  
Aerosol Plume

Abstract. This paper reports on backscatter and depolarization measurements by an airborne lidar in the Arctic during the ASTAR 2004 campaign. A unique weather situation facilitated the observation of the aerosol concentration under strongly forced atmospheric conditions. The vigorous easterly winds distorted the flow past Svalbard in such a way that mesoscale features were visible in the remote-sensing observations: The formation of a well-mixed aerosol layer inside the Adventdalen and the subsequent thinning of the aerosol plume were observed over the Isfjorden. Additionally, mobilization of sea salt aerosols due to a coastal low-level jet at the northern tip of Svalbard resulted in a sloped boundary layer toward north. Mesoscale numerical modelling was applied to identify the sources of the aerosol particles and to explain the observed patterns.

THE APPLICATION OF THE ARNDT–EISTERT REACTION TO THE SYNTHESIS OF FATTY ACIDS OF HIGH MOLECULAR WEIGHT

1950 ◽  
Vol 28b (9) ◽  
pp. 556-560 ◽  
Author(s):  
F. A. Vandenheuvel ◽  
P. Yates
Keyword(s):  
Fatty Acids ◽  
Molecular Weight ◽  
Carboxylic Acid ◽  
Stearic Acid ◽  
High Molecular Weight ◽  
Efficient Method ◽  
Convenient Method ◽  
Ultraviolet Absorption ◽  
Aliphatic Carboxylic Acid ◽  
Eicosanoic Acid

The Arndt–Eistert reaction offers a convenient method for the synthesis of the higher members of the aliphatic carboxylic acid series. Nonadecanoic acid, eicosanoic acid, and heneicosanoic acid have been prepared successively from stearic acid in good yields. An efficient method of purification of the synthetic products is described. The ultraviolet absorption maxima for some diazoketones derived from the higher members of the aliphatic carboxylic acid series are recorded.

scholarly journals Fatty acid chemistry of Atrichum undulatum and Hypnum andoi

2012 ◽  
Vol 66 (2) ◽  
pp. 207-209 ◽  
Author(s):  
Boris Pejin ◽  
Ljubodrag Vujisic ◽  
Marko Sabovljevic ◽  
Vele Tesevic ◽  
Vlatka Vajs
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Linolenic Acid ◽  
Essential Fatty Acids ◽  
Behenic Acid ◽  
Moss Species

The fatty acid composition of the moss species Atrichum undulatum (Hedw.) P. Beauv. (Polytrichaceae) and Hypnum andoi A.J.E. Sm. (Hypnaceae) collected in winter time were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) as a contribution to their chemistry. Eight fatty acids were identified in the chloroform/methanol extract 1:1 of A. undulatum (linoleic acid 26.80%, palmitic acid 22.17%, ?-linolenic acid 20.50%, oleic acid 18.49%, arachidonic acid 6.21%, stearic acid 3.34%, cis-5,8,11,14,17-eicosapentaenoic acid 1.52% and behenic acid 1.01%), while six fatty acids were found in the same type of extract of H. andoi (palmitic acid 63.48%, erucic acid 12.38%, stearic acid 8.08%, behenic acid 6.26%, lignoceric acid 5.16% and arachidic acid 4.64%). According to this study, the moss A. undulatum can be considered as a good source of both essential fatty acids for humans (linoleic acid and ?-linolenic acid) during the winter.

scholarly journals Nutritional components of the sea cucumber Holothuria scabra

2017 ◽  
Vol 7 (3) ◽  
pp. 168 ◽  
Author(s):  
Morakot Sroyraya ◽  
Peter J. Hanna ◽  
Tanapan Siangcham ◽  
Ruchanok Tinikul ◽  
Prapaporn Jattujan ◽  
...  
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Stearic Acid ◽  
Sea Cucumber ◽  
Body Wall ◽  
Essential Fatty Acids ◽  
Essential Amino Acids ◽  
Whole Body ◽  
Holothuria Scabra ◽  
Arachidonic Acids

Background: Holothuria scabra is one of the most commercially important species found in the Pacific region. The sea cucumber extracts have been widely reported to have beneficial health effects. The aim of this study was to determine the nutritional compositions of H. scabra, and compare its important nutritional contents with that of other species.Methods: The sea cucumbers were dissected, sliced into small pieces, and then freeze-dried. The nutritional compositions, including proximate composition, amino acids, fatty acids, collagen, GABA, Vitamin A, C, and E of the whole body and body wall of H. scabra, were analyzed.Results: H. scabra contained a high quantity of protein (22.50% in whole body and 55.18% in body wall) and very low lipids (1.55% in whole body and 1.02% in body wall). The three most abundant amino acids found in both the whole body and body wall were glycine, glutamic acid, and proline. The main fatty acids found in the whole body were stearic acid and nervonic acid, and in the body wall were arachidonic acid and stearic acid. The whole body and body wall also contained high levels of essential amino acids, essential fatty acids, and collagen, in addition to moderate amounts of vitamin E and low amounts of GABA and vitamin C.Conclusions: The sea cucumber, H. scabra, contained high quantity of protein and very low lipid. It contained high essential amino acids, essential fatty acids, nervonic and arachidonic acids, and collagen, which also contained GABA, vitamin C, and vitamin E.Keywords: sea cucumber; Holothuria scabra; nutrition components; functional food            

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