Pengaruh Panjang Rantai Karbon dan Derajat Ketidakjenuhan terhadap Karakteristik Pembakaran Droplet Asam Lemak Tunggal

2021 ◽  
Vol 12 (2) ◽  
pp. 331-347
Author(s):  
Ibrahim Ahmad Ibadurrohman ◽  
◽  
Nurkholis Hamidi ◽  
Lilis Yuliati
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Burning Rate ◽  
Power Output ◽  
Ignition Delay ◽  
Carbon Chain ◽  
Specific Power ◽  
Carbon Chain Length ◽  
Degree Of Unsaturation ◽  
Specific Power Output

This study aimed to investigate the effect of the different carbon chain lengths and the degree of unsaturation of six fatty acids as the constituent of vegetable oils. The droplet combustion was carried out at an ambient temperature and atmospheric pressure. The variation in the carbon chain length and the degree of unsaturation resulted in different physical and chemical properties of the fuel, which affect the droplet combustion characteristics. The increase of the carbon chain length results in longer ignition delay times and shorter burning durations, as well as higher droplet temperatures, burning rate constant, and specific power output. Conversely, an increase in the degree of unsaturation with the presence of double bond results in shorter ignition delay and longer burning duration, as well as higher droplet temperatures, but lower burning rate constant and specific power output. The droplet diameter evolution divides the combustion period into unsteady burning zones and quasi-linear burning zones. The flame dimension of unsaturated fatty acid is higher due to the soot formation at the top of the flame. A bluish flame related to the higher oxygen content in the molecule can be observed in saturated fatty acids. The short-chain saturated fatty acid has a large non-luminous zone because they are rich in oxygen. In contrast, the long-chain saturated fatty acid has a narrow non-luminous zone with high flame radiation.

scholarly journals SELECTIVITY OF CANDIDA RUGOSA LIPASE IMMOBILIZED ONTO LAYERED DOUBLE HYDROXIDES AS CATALYST IN SYNTHESIS OF FATTY ACID ESTERS

2016 ◽  
Vol 78 (5-6) ◽  
Author(s):  
Mohd Basyaruddin Abdul Rahman ◽  
Siti Salhah Othman ◽  
Noor Mona Md Yunus
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chain Length ◽  
Candida Rugosa ◽  
Candida Rugosa Lipase ◽  
Carbon Chain ◽  
Fatty Acid Esters ◽  
Carbon Chain Length ◽  
Chain Lengths ◽  
Acid Esters

The enzymatic selectivity of Lipase from Candida rugosa immobilized onto a calcined layered double hydroxide (CLDHs-CRL) towards the chain-length of fatty acids and alcohols in the synthesis of fatty acid esters was investigated.  The results showed that CMAN-CRL catalyzed the esterification process with fatty acids of medium chain lengths (C10-C14) effectively while, CNAN-CRL and CZAN-CRL exhibited high percentage conversion in fatty acids with carbon chain lengths of C8-C12 and C10-C18, respectively. In the alcohol selectivity study, CMAN-CRL showed high selectivity toward alcohols with carbon chain lengths of C4, C6 and C10.  On the other hand, both CNAN-CRL and CZAN-CRL exhibited rather low selectivity towards longer carbon chain length of alcohols. 

scholarly journals Polyenoic very-long-chain fatty acids mobilize intracellular calcium from a thapsigargin-insensitive pool in human neutrophils. The relationship between Ca2+ mobilization and superoxide production induced by long- and very-long-chain fatty acids

1995 ◽  
Vol 311 (2) ◽  
pp. 689-697 ◽  
Author(s):  
S J Hardy ◽  
B S Robinson ◽  
A Ferrante ◽  
C S T Hii ◽  
D W Johnson ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chain Length ◽  
Carbon Chain ◽  
Superoxide Production ◽  
Human Neutrophils ◽  
Carbon Chain Length ◽  
Long Chain Fatty Acids ◽  
Long Chain ◽  
Chain Fatty Acids

Fatty acids with more than 22 carbon atoms (very-long-chain fatty acids; VLCFAs) are normal cellular components that have been implicated in the pathophysiology of a number of peroxisomal disorders. To date, however, essentially nothing is known regarding their biological activities. Ca2+ mobilization is an important intracellular signalling system for a variety of agonists and cell types. Given that several polyunsaturated long-chain fatty acids mobilize intracellular Ca2+ and that we have postulated that the VLCFAs may be involved in signal transduction, we examined whether the tetraenoic VLCFA induced Ca2+ mobilization in human neutrophils. We report that fatty acid-induced intracellular Ca2+ mobilization declined for fatty acid species of more than 20 carbon atoms, but increased again as the carbon chain length approached 30. This Ca2+ mobilization occurred independently of inositol 1,4,5-triphosphate production and protein kinase C translocation and involved both the release of Ca2+ from the intracellular stores and changes to the influx or efflux of the ion. We further observed that triacontatetraenoic acid [30:4(n-6)] mobilized Ca2+ from a thapsigargin-insensitive intracellular pool distinct from the thapsigargin-sensitive pools affected by arachidonic acid [20:4(n - 6)] or N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP). 20:4 (n - 6) induced strong superoxide production (chemiluminescence) which was inhibited by thapsigargin pretreatment. In contrast, fatty acid-induced superoxide production progressively declined as the carbon chain length increased beyond 20-22 carbon atoms. Further studies suggested that the thapsigargin-insensitive Ca2+ mobilization elicited by 30:4 (n - 6) was not related to oxyradical formation, while the thapsigargin-sensitive Ca2+ mobilization induced by 20:4 (n - 6) may be involved in the initiation but not necessarily the maintenance of superoxide production. In conclusion, this is the first report to demonstrate a biological activity for the VLCFA and indicates that 30:4 (n - 6) influences second messenger systems in intact cells that differ from those affected by long-chain fatty acids such as 20:4 (n - 6).

METABOLIC PATTERNS OF THE FATTY ACIDS OF PERIPLANTETA AMERICANA (L.) DURING ITS EMBRYONIC DEVELOPMENT

1966 ◽  
Vol 44 (2) ◽  
pp. 247-258 ◽  
Author(s):  
John E. Kinsella
Keyword(s):  
Fatty Acids ◽  
Life Cycle ◽  
Fatty Acid ◽  
Fatty Acid Content ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Gas Liquid Chromatography ◽  
Total Fatty Acids ◽  
Fatty Acid Patterns ◽  
Oleic And Linoleic Acids

The fatty acid composition of the various lipid fractions of Periplanteta americana was analyzed by gas–liquid chromatography at successive stages during embryogenesis. Qualitative analysis revealed the presence of at least 30 fatty acids during all stages of the life cycle ranging in carbon chain length from C6 through C24. Palmitic, stearic, oleic, and linoleic acids composed over 95% of the total fatty acids. The percentage distribution of major fatty acids remained constant throughout the life cycle. Total fatty acid content decreased by 28% during development mainly because of the catabolism of palmitic, oleic, and linoleic acids. Fatty acid patterns suggest that partially hydrolyzed triglyceride molecules are converted to phospholipid molecules during development.

Fatty Acid Composition of Eggs during Development of the Cotton Leaf-Worm, Spodoptera littoralis Boisduval

1981 ◽  
Vol 36 (7-8) ◽  
pp. 562-563 ◽  
Author(s):  
I. Z. Boctor
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Spodoptera Littoralis ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Cotton Leaf ◽  
Total Fatty Acids ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic ◽  
Oleic And Linoleic Acids

Abstract Fatty Acids, Spodoptera littoralis, Eggs Gas-liquid chromatographic analysis of egg lipids during development of Spodoptera littoralis showed the presence of 13 fatty acids ranging in carbon chain length from caproic (C6:0) to linolenic acid (C 18:3). Palmitic, palmitoleic, stearic, oleic and linoleic acids composed over 90% of the total fatty acids. Palmitic acid was always the predominant fatty acid and oleic acid was the second most abundant.

Reutilization of fatty acid carbons for lung lipid synthesis

1981 ◽  
Vol 240 (4) ◽  
pp. E435-E440
Author(s):  
J. L. Rabinowitz ◽  
T. Cardwell ◽  
D. J. Bassett
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Degradation Products ◽  
Lipid Synthesis ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Bicarbonate Buffer ◽  
Glucose Carbon ◽  
Degradation Analysis ◽  
Lung Lipid

The utilization of glucose, palmitate, and oleate for the synthesis of lung lipids was studied in isolated rat lungs. Lungs were ventilated with 5% CO2 in air and perfused for 100 min with a Krebs-Ringer bicarbonate buffer (pH 7.4), containing 3% fatty acid-free albumin and either 5.6 mM [U-14C]glucose or 0.25 mM [1-14C]palmitate, or 0.25 mM [1-14C]-oleate. At the end of 100 min of perfusion with these precursors, between 73 and 85% of total lipid 14C was recovered as phospholipid. Glucose carbon was mainly incorporated into triglyceride fatty acids (TG-FA) and phosphatidylcholine fatty acids (PC-FA) of 16- and 18-carbon chain length. After perfusion with [14C]palmitate and [14C]oleate, only 65 and 20% of 14C was recovered as PC 16-carbon and 18-carbon FA, respectively. The remaining 14C was mainly recovered as FA shorter than the 14C precursors. Schmidt degradation analysis of lipid FA demonstrated considerable labeling of alkyl carbons on perfusion with the carboxyl-labeled precursors, indicating that FA degradation products were used for synthesis of lipid FA. This process was enhanced on addition of glucose to the perfusate.

scholarly journals Effects of Perfluorinated Fatty Acids with Different Carbon Chain Length on Fatty Acid Profiles of Hepatic Lipids in Mice

2011 ◽  
Vol 34 (6) ◽  
pp. 856-864 ◽  
Author(s):  
Naomi Kudo ◽  
Tohru Yamazaki ◽  
Takeshi Sakamoto ◽  
Katsuyoshi Sunaga ◽  
Tadashi Tsuda ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chain Length ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Fatty Acid Profiles ◽  
Hepatic Lipids

scholarly journals Effect of Carbon Chain Length, Ionic Strength, and pH on the In Vitro Release Kinetics of Cationic Drugs from Fatty-Acid-Loaded Contact Lenses

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1060
Author(s):  
Cesar Torres-Luna ◽  
Naiping Hu ◽  
Roman Domszy ◽  
Xin Fan ◽  
Jeff Yang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Ionic Strength ◽  
Chain Length ◽  
Contact Lenses ◽  
Release Kinetics ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Cationic Drugs ◽  
Kinetics Of

This paper explores the use of fatty acids in silicone hydrogel contact lenses for extending the release duration of cationic drugs. Drug release kinetics was dependent on the carbon chain length of the fatty acid loaded in the lens, with 12-, 14- and 18-carbon chain length fatty acids increasing the uptake and the release duration of ketotifen fumarate (KTF) and tetracaine hydrochloride (THCL). Drug release kinetics from oleic acid-loaded lenses was evaluated in phosphate buffer saline (PBS) at different ionic strengths (I = 167, 500, 1665 mM); the release duration of KTF and THCL was decreased with increasing ionic strength of the release medium. Furthermore, the release of KTF and THCL in deionized water did not show a burst and was significantly slower compared to that in PBS. The release kinetics of KTF and THCL was significantly faster when the pH of the release medium was decreased from 7.4 towards 5.5 because of the decrease in the relative amounts of oleate anions in the lens mostly populated at the polymer–pore interfaces. The use of boundary charges at the polymer–pore interfaces of a contact lens to enhance drug partition and extend its release is further confirmed by loading cationic phytosphingosine in contact lenses to attract an anionic drug.

Evaluation of an Improved Sublimation Apparatus Utilizing Carbon-14 Labeled Methyl Esters of Fatty Acids

1963 ◽  
Vol 46 (6) ◽  
pp. 947-949
Author(s):  
A J Sheppard ◽  
L A Ford
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chain Length ◽  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Mixed Fatty Acid ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Carbon 14 ◽  
Acid Methyl

Abstract An improved sublimation appparatus has been designed and tested. The unit was tested with carbon-14 labeled methyl esters of fatty acids up through 22 carbon chain length. Samples of 40 mg or less of mixed fatty acid methyl esters can be sublimed routinely with recoveries of approximately 100%.

Performance Comparison and Parametric Analysis of sCO2 Power Cycles Configurations

2018 ◽  
Author(s):  
Ali S. Alsagri ◽  
Andrew Chiasson ◽  
Ahmad Aljabr
Keyword(s):  
Power Output ◽  
Thermal Efficiency ◽  
Performance Comparison ◽  
Specific Power ◽  
Brayton Cycle ◽  
Computationally Efficient ◽  
Power Cycles ◽  
Optimization Study ◽  
Specific Power Output ◽  
Improve Calculation

A thermodynamic analysis and optimization of four supercritical CO2 Brayton cycles were conducted in this study in order to improve calculation accuracy; the feasibility of the cycles; and compare the cycles’ design points. In particular, the overall thermal efficiency and the power output are the main targets in the optimization study. With respect to improving the accuracy of the analytical model, a computationally efficient technique using constant conductance (UA) to represent heat exchanger performances is executed. Four Brayton cycles involved in this compression analysis, simple recaptured, recompression, pre-compression, and split expansion. The four cycle configurations were thermodynamically modeled and optimized based on a genetic algorithm (GA) using an Engineering Equation Solver (EES) software. Results show that at any operating condition under 600 °C inlet turbine temperature, the recompression sCO2 Brayton cycle achieves the highest thermal efficiency. Also, the findings show that the simple recuperated cycle has the highest specific power output in spite of its simplicity.

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