scholarly journals Temperature-Dependent Thermal Conductivity Measurement System for Various Heat Transfer Fluids

2021 ◽  
Vol 20 (4) ◽  
pp. 195-202
Author(s):  
Yunita Anggraini ◽  
Alfriska O. Silalahi ◽  
Inge Magdalena Sutjahja ◽  
Daniel Kurnia ◽  
Sparisoma Viridi ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Stearic Acid ◽  
Lauric Acid ◽  
Fatty Acid Content ◽  
Coconut Oil ◽  
Conductivity Measurement ◽  
Heat Conducting

Accurate measurement of the thermal conductivity of a heat transfer fluid (HTF) is important for optimizing the performance of a thermal energy storage system. Herein, we develop a system to measure the thermal conductivity of an HTF during temperature variation, and the system was checked to measure several samples comprising water, lauric acid, stearic acid, oleic acid, and coconut oil. The thermal conductivity was measured using a KS-1 sensor of a KD2 Pro analyzer. In the study, a static heat conducting medium was used to control the temperature of the fluid, instead of the commonly used flowing water bath. The measured thermal conductivities of water (298 to 318 K) and lauric acid (323 to 373 K), stearic acid (358 to 372 K), oleic acid (334 to 372 K), and coconut oil (298 to 363 K) were compared to data from previous studies and fitted to available models. The accuracy of the data is further analyzed by relating the number of C and H atoms in the fatty acid, and the fatty acid content in coconut oil.

scholarly journals Physicochemical characterization of resistant starch type V (RS5) from manggu cassava starch (Manihot esculenta)

Food Research ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 228-234
Author(s):  
D.N. Faridah ◽  
I. Andriani ◽  
Z.A. Talitha ◽  
F.S. Budi
Keyword(s):  
Fatty Acid ◽  
Stearic Acid ◽  
Lauric Acid ◽  
Resistant Starch ◽  
Physicochemical Characterization ◽  
Coconut Oil ◽  
Lipid Complex ◽  
Tapioca Starch ◽  
Modified Tapioca Starch ◽  
Type V

Resistant starch has been well known to have beneficial health effects, mainly for digestive tracts. Starch isolated from cassava showed characteristics required to produce resistant starch type 5 (RS5). In this study, we modified tapioca starch through the gelatinization process with the addition of palm oil, coconut oil, stearic acid and lauric acid with 3 treatments, i.e. concentration (1) 10%, (2) 20% and (3) 30%. The result of study showed that modification of starch can decrease starch digestibility, increase levels of resistant starch and lower amylose levels. The analysis using X-Ray diffraction, strearic acid 30% had the peak at 7.5°, 22° and 24°. Peak 7.5° was a amylose-lipid complex as RS5. The profile of starch gelatinization using Rapid Visco Analyzer (RVA) showed that the addition of fatty acid can decrease the value of breakdown, setback, and peak viscosity. These results indicates modification of tapioca starch with fatty acid (stearic acid or lauric acid) can form amylose-lipid complex (RS5).

Determination of fatty acid content in some edible insects of Mexico

2016 ◽  
Vol 2 (1) ◽  
pp. 37-42 ◽  
Author(s):  
J.M. Pino Moreno ◽  
A. Ganguly
Keyword(s):  
Oleic Acid ◽  
Fatty Acid ◽  
Acid Content ◽  
Periplaneta Americana ◽  
Fatty Acid Content ◽  
Capric Acid ◽  
Caproic Acid ◽  
Insect Species ◽  
Edible Insects

In the present paper we have determined the fatty acid content of some edible insects of Mexico. A comparative analysis of the insect species studied in this research showed that caproic acid was present in a minimal proportion which ranged between 0.01 for Periplaneta americana (nymphs) and 0.06 (g/100 g, dry basis) for Euschistus strenuus. The highest proportion of caprilic acid (0.09) was found in Tenebrio molitor (adults). Atta sp. had the highest amount of capric acid (0.26). Polistes sp. was found to be rich in lauric acid (0.77) and for myristic acid it had the highest content (5.64). Dactylopius sp. and E. strenuus were rich in palmitic acid (14.89). Euschistus taxcoensis had the highest quantity of palmitoleic acid (12.06). Llaveia axin exhibited the highest quantity of stearic acid (22.75). Polistes sp. was found to be rich in oleic acid (38.28). The highest quantity of linoleic acid was observed in T. molitor (larvae) (10.89), and in L. axin the highest content of linolenic acid (7.82) was obtained. A comparison between the species under the present investigation revealed that, in general, the insects are poor in caproic, caprilic, capric, lauric, myristic, palmitoleic and linolenic acids, because the quantities were either minimal or could not be detected at all. They had moderate quantities of stearic, palmitic and linoleic acids and had high quantities of oleic acid. Finally it was concluded that although a particular insect species is unable to fulfil the total fatty acid need for a human, if consumed in combination they could definitely be able to supply a good amount of this highly valued nutrient.

scholarly journals Profile Analysis of Fatty Acids of Tengkawang (Shorea Sumatrana) Oil Using GC-MS and Antibacterial Activity

2020 ◽  
Vol 8 (2) ◽  
pp. 114-119
Author(s):  
Diah Gusti Riski ◽  
Rico Gewana Resdy Maulana ◽  
Edwin Permana ◽  
Intan Lestari ◽  
Indra Lasmana Tarigan
Keyword(s):  
Antibacterial Activity ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Stearic Acid ◽  
Acid Chloride ◽  
Salmonella Enteritidis ◽  
Profile Analysis ◽  
Negative Control ◽  
Chemical Diversity ◽  
Diffusion Method

The Shorea sumatrana (tengkawang) plant is endemic to Indonesia, especially in Kalimantan and Sumatera regions, which produces chemical diversity especially as a natural drugs. Specific aims to investigate both the profile analysis of fatty acid and antibacterial potential of tengkawang oil. The extract of tengkawang oil was carried out using the soxhlet extraction method. The profile analysis of fatty acid was verified by GC-MS and the antibacterial activity was evaluated using disc-diffusion method. The profile analysis of fatty acid of tengkawang oil indicated the presence of palmitic acid (17.26%), stearic acid (60.68%), oleic acid (11.98%), oleic acid chloride (1.80%), stearic acid chloride (1.86%), glycidyl stearate (1.92%), diethyl phthalate (4%), and 2-monopalmitin (0.5%). We determined the antibacterial activity by the diameter of inhibition of growth zone against Salmonella enteritidis, Escherichia coli, Staphylococcus aureus, and Bacillus cereus at a concentration of 12.5%, 25%, 50%. These were compared with standard tetracycline as positive control and DMSO was assigned negative control. It was found that the highest percentage of fatty acid in tengkawang oil is stearic acid, at 60.68%, and that tengkawang oil is an antibacterial agent with a concentration optimum at 25% with more susceptibility to Gram-positive than Gram-negative bacteria.

scholarly journals KOMPOSISI ASAM LEMAK CACING LAUT SIASIA (SIPUNCULUS, SP) DARI PERAIRAN PANTAI PULAU NUSALAUT

2017 ◽  
Vol 4 (1) ◽  
pp. 10-16
Author(s):  
Bernita Silaban
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Stearic Acid ◽  
Eicosapentaenoic Acid ◽  
Lauric Acid ◽  
Coastal Waters ◽  
Myristic Acid ◽  
Palmitoleic Acid ◽  
Fat Content ◽  
Coastal Communities

Background: "Siasia" is a seaworm species in the phylum that includes Sipuncula Sipunculidea class. This animal has been consumed for generations by coastal communities Nusalaut Island, central mollucas but not yet universally known. Until now there has been obtained gisi complete composition. This study aimed to identify the composition of fatty acids contained in vain fresh seaworms. Methods: Seaworms vain taken from coastal waters of Negeri Titawaai and Nalahia Nusalaut Island, Central Moluccas in March 2014. The parameters analyzed include methods is sokhlet fat content and fatty acid by GC method. Results: The results showed fresh siasia fat content 1.12% of coastal waters Titawaai while 1.91% of coastal waters Nalahia. Fatty acids seaworms were identified from coastal waters Titawai  is  kaparat acid (C10: 0), lauric acid (C12: 0), myristic acid (C14: 0), palmitoleic acid (C16: 1), stearic acid (C18: 0), linolenic acid (C18: 3) acid and eicosapentaenoic (C20: 5) while the fatty acids of  seaworm vain of coastal waters Nalahia include is lauric acid (C12: 0), myristic acid (C14: 0), palmitoleic acid ( C16: 1), stearic acid (C18: 0) and eicosapentaenoic acid (C20: 3). Conclusion: The fat content of fresh siasia sea worms is 1.12% from the waters of Titawaai beach, while 1.91% of the waters of the coast of Nalahia.

Effect of Resin Components on the Reversion Process of Sulfur-Vulcanized Guayule Rubber

1986 ◽  
Vol 59 (5) ◽  
pp. 800-808 ◽  
Author(s):  
James M. Sloan ◽  
Michael J. Maghochetti ◽  
Walter X. Zukas
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Stearic Acid ◽  
Naturally Occurring

Abstract An effort to characterize the reversion process of guayule rubber when naturally-occurring guayule resin components are present has shown that these components act as a reversion-retarding material. The amount of reversion resistance varies as a function of temperature, concentration, and type of fatty acid. Of the three fatty acids used, linoleic acid, stearic acid, and oleic acid, linoleic acid performed the best for reversion resistance, followed by stearic acid, then oleic acid. When the temperature was increased 10°C, an increase of 15% reversion was observed. This held true for the three temperatures studied. In addition, the amount of reversion improvement upon addition was 20% reversion. In the case of curing at 150°C, this resulted in 0% reversion. The 20% resistance improvment was consistent for the 3 temperatures studied.

Optimization of Virgin Coconut Oil (VCO) Production with Diffuser Type Aeration Method

2021 ◽  
Vol 6 (4) ◽  
pp. 139-143
Author(s):  
Nyoman Sri Widari ◽  
Rahaju Saraswati ◽  
Bambang Sutejo
Keyword(s):  
Fatty Acid ◽  
Flow Rate ◽  
Acid Content ◽  
Air Flow ◽  
Fatty Acid Content ◽  
Maximum Yield ◽  
Coconut Oil ◽  
Efficient Production ◽  
Air Flow Rate ◽  
Virgin Coconut Oil

Virgin coconut oil (VCO) is pure coconut oil with low free fatty acid content and high lauric acid content. VCO has been produced in many home industries where the yield obtained is still very small. So, the researchers tried to find a more efficient production process so that they could obtain high process yields. Researchers made VCO using the aeration method with a diffuser type aerator. The experimental variables were air flow rate (L / min): 0.6; 1.8; 4.0; 4,5 and the duration of the aeration process (hours): 2; 3; 4; 5, by using coconut milk from 1 kg of grated coconut in 1 liter of water, the maximum yield is 33.5% at an air flow rate of 4.0 L / min with an aeration time of 4 hours. The quality of VCO obtained were: water content of 0.02%; iodine number 5,54%; peroxidation number 1.36 g.iod / 100 g; 0.19% free fatty acids; saturated fatty acid content of 93.71% and unsaturated fatty acid 6.24% and the color is very clear. The quality test results obtained are in accordance with the quality standards required by SNI 7381-2008.

Effect of increasing stearoyl coenzyme A desaturase mRNA concentrations using forage and concentrate diets on the fatty acid composition of ovine adipose tissue

2002 ◽  
Vol 2002 ◽  
pp. 206-206 ◽  
Author(s):  
Z.C.T.R. Daniel ◽  
R.J. Wynn ◽  
A.M. Salter ◽  
P.J. Buttery
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid Composition ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Stearic Acid ◽  
Acid Composition ◽  
Coenzyme A ◽  
Saturated Fatty Acids ◽  
Mrna Levels

Compared to meat from other animals lamb contains high levels of saturated fat, particularly stearic acid which comprises 18% of the total fatty acids (Enser et al, 1996). This stearic acid can be desaturated in the tissue by stearoyl coenzyme A desaturase (SCD) to produce oleic acid. In sheep SCD is produced from a single gene and the levels of SCD mRNA in the tissue correlate well with oleic acid (Ward et al, 1998, Barber et al, 2000) suggesting that an upregulation of SCD activity may increase the relative proportions of unsaturated and saturated fatty acids and so significantly improve the nutritional quality of sheep meat. Our recent studies have shown that insulin increases SCD mRNA levels and monounsaturated fatty acid synthesis in cultured ovine adipose tissue explants (Daniel et al, 2001). The present study was designed to investigate whether feeding a diet believed to manipulate SCD mRNA concentrations would significantly alter the fatty acid composition of lamb.

In vitro ruminal methane suppression by lauric acid as influenced by dietary calcium

2002 ◽  
Vol 82 (2) ◽  
pp. 233-239 ◽  
Author(s):  
A. Machmüller ◽  
C. R. Soliva ◽  
M. Kreuzer
Keyword(s):  
Organic Matter ◽  
Fatty Acid ◽  
Lauric Acid ◽  
Rumen Fluid ◽  
Fatty Acid Pattern ◽  
Coconut Oil ◽  
Bacterial Count ◽  
Ammonia Concentration ◽  
Fiber Fermentation

The effect of Ca supplementation on the methane-suppressing effect of lauric acid was investigated in an experiment based on a 2 × 2-factorial arrangement using the in vitro system Rusitec. Additional Ca was supplemented at 1 g kg-1 diet in the form of compounds of relatively low solubility in rumen fluid. Lauric acid (C12:0), the predominant effective medium-chain fatty acid in coconut oil, was added at a level of 50 g kg-1. Adding C12:0 did not affect bacterial count, but eliminated ciliate protozoa from fermenters. Ammonia concentration in fermentation mixture declined and volatile fatty acid pattern changed with C12:0. The apparent degradation rate of total organic matter was not altered by C12:0, but fiber fermentation was depressed (P < 0.001). Effects of Ca on microbial counts and fermentation characteristics remained low. Without additional Ca, C12:0 reduced the average daily methane release (mmol g-1 organic matter degraded) by 76%. In comparison, C12:0 only reduced methane production by 47% when additional Ca was included in the diet (interaction of C12:0 and Ca, P < 0.05). The present results suggest that the dietary content of soap-forming Ca has to be kept low in order to achieve a high methane-suppressing effect of lauric acid. Key words: Methane, lauric acid, lipids, calcium, Rusitec, ruminants

scholarly journals Composition of Oil from the Seeds of Cassia Sophera Linn.

1970 ◽  
Vol 42 (1) ◽  
pp. 75-78 ◽  
Author(s):  
M Mostafa ◽  
Momtaz Ahmed ◽  
Ismet Ara Jahan ◽  
Jasim Uddin Choudhury
Keyword(s):  
Oleic Acid ◽  
Linoleic Acid ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Elaidic Acid ◽  
Lauric Acid ◽  
Arachidic Acid

The oil obtained from the seeds of Cassia sophera Linn was analyzed by GC-MS and a total of 42 compounds have been identified. The major constituents are palmitic acid (22.82 %), linoleic acid (8.32 %), elaidic acid (19.16 %), stearic acid (9.86 %), 5-isopropyl -6-methyl-3-heptyne-2,5-diol (6.44 %), undecyl lauric acid (6.61 %), oleic acid (2.1 %), arachidic acid (3.57 %) and 3α, 7β-dihyodxy -5β, 6β-epoxycholestane (5.9 %). Bangladesh J. Sci. Ind. Res. 42(1), 75-78, 2007

scholarly journals Improved Thermophysical Properties and Energy Efficiency of Aqueous Ionic Liquid/MXene Nanofluid in a Hybrid PV/T Solar System

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1372 ◽  
Author(s):  
Likhan Das ◽  
Khairul Habib ◽  
R. Saidur ◽  
Navid Aslfattahi ◽  
Syed Mohd Yahya ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Ionic Liquid ◽  
Palm Oil ◽  
Thermophysical Properties ◽  
Conductivity Measurement ◽  
Optimum Concentration ◽  
Heat Transfer Fluid ◽  
Solar Pv ◽  
T System

In recent years, solar energy technologies have developed an emerging edge. The incessant research to develop a power source alternative to fossil fuel because of its scarcity and detrimental effects on the environment is the main driving force. In addition, nanofluids have gained immense interest as superior heat transfer fluid in solar technologies for the last decades. In this research, a binary solution of ionic liquid (IL) + water based ionanofluids is formulated successfully with two dimensional MXene (Ti3C2) nano additives at three distinct concentrations of 0.05, 0.10, and 0.20 wt % and the optimum concentration is used to check the performance of a hybrid solar PV/T system. The layered structure of MXene and high absorbance of prepared nanofluids have been perceived by SEM and UV–vis respectively. Rheometer and DSC are used to assess the viscosity and heat capacity respectively while transient hot wire technique is engaged for thermal conductivity measurement. A maximum improvement of 47% in thermal conductivity is observed for 0.20 wt % loading of MXene. Furthermore, the viscosity is found to rise insignificantly with addition of Ti3C2 by different concentrations. Conversely, viscosity decreases substantially as the temperature increases from 20 °C to 60 °C. However, based on their thermophysical properties, 0.20 wt % is found to be the optimum concentration. A comparative analysis in terms of heat transfer performance with three different nanofluids in PV/T system shows that, IL+ water/MXene ionanofluid exhibits highest thermal, electrical, and overall heat transfer efficiency compared to water/alumina, palm oil/MXene, and water alone. Maximum electrical efficiency and thermal efficiency are recorded as 13.95% and 81.15% respectively using IL + water/MXene, besides that, heat transfer coefficients are also noticed to increase by 12.6% and 2% when compared to water/alumina and palm oil/MXene respectively. In conclusion, it can be demonstrated that MXene dispersed ionanofluid might be great a prospect in the field of heat transfer applications since they can augment the heat transfer rate considerably which improves system efficiency.

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