scholarly journals Effect of Temperature on the Composition of a Synthetic Hydrocarbon Aviation Lubricating Oil

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1606 ◽  
Author(s):  
Zhuoting Gan ◽  
Ting Yao ◽  
Meng Zhang ◽  
Jianqiang Hu ◽  
Xiaoxiao Liao ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Pour Point ◽  
Kinematic Viscosity ◽  
Molecular Level ◽  
Acid Number ◽  
Lubricating Oil ◽  
Effect Of Temperature ◽  
Gas Chromatography Mass Spectrometry ◽  
Chemical Compositions ◽  
Synthetic Hydrocarbon

Synthetic hydrocarbon aviation lubricating oils (SHALOs) gradually degrade over time when subjected to high temperatures, resulting in their composition and properties varying over the operation lifetime. Therefore, understanding the SHALO degradation properties by elucidating the mechanism on a molecular level, as a function of high temperature, is of interest. A SHALO was subjected to thermal treatment (TT) at 180, 200, 230, 250, 270, or 300 °C for 2 h. The chemical compositions of six TT samples and one fresh oil were analyzed by fourier transform infrared F spectroscopy, advanced polymer chromatography, and gas chromatography/mass spectrometry. Furthermore, the physicochemical properties, such as kinematic viscosity, pour point, and acid number, of seven samples were determined. The oil samples were grouped by cluster analysis (CA) using a statistical method. The SHALO was identified to comprise 20 functional groups, including comb-like alkanes, long-chain diesters, amines, phenols, and other compounds. TT at <230 °C caused partial cracking of the SHALO base oils, with a concomitant change in the antioxidant content and type, and the polycondensation reactions were dominant. The observed antioxidant changes were not obvious from TT at >230 °C. A large number of small-molecule compounds were detected, including n-alkanes and olefins. TT at 250 °C was shown to be an important threshold for the kinematic viscosity, pour point, and acid number of the samples. Below 250 °C, the sample properties were relatively stable; but at elevated TT temperatures (>250 °C), the properties were observed to dramatically degrade. As the sample color was highly sensitive to temperature, the TT temperature induced rapid and significant color changes. The CA analysis results for the oil compounds at the molecular level were in good agreement with observed changes in the physicochemical properties at the macro level.

scholarly journals Effect of Temperature on the Chemical Composition and Physicochemical Properties of Diester Aviation Lubrication Oil

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Ting Yao ◽  
Na Zhang ◽  
Jianqiang Hu ◽  
Xiaoxiao Liao ◽  
Yongli Shen ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Physicochemical Properties ◽  
Degradation Mechanism ◽  
Oxidation Stability ◽  
Lubricating Oil ◽  
Effect Of Temperature ◽  
Gas Chromatography Mass Spectrometry ◽  
Low Molecular Weight ◽  
Chemical Compositions ◽  
Main Process

High temperature is the main factor responsible for degrading the lubrication and antiwear properties of aero-lubricating oils. Accordingly, this study assessed the effects of thermal treatment of diester aviation lubricating oil and the associated mechanism. Fourier-transform infrared spectroscopy and gas chromatography/mass spectrometry analyses showed that low-molecular-weight compounds, such as monoesters, diesters, alcohols, and olefins, were the primary degradation products. An assessment of the degradation mechanism of bis(2-ethylhexyl)decanedioate showed that pyrolysis, resulting in the cleavage of β-C–H and C–C bonds, was the main process involved. Additional investigation using advanced polymer chromatography showed that the molecular weights of oil samples changed slightly at high temperatures, while the viscosity and viscosity-temperature index values were relatively stable. High-pressure differential scanning calorimetry established that the thermal oxidation stability of these oils decreased above 250°C. Finally, variations in the chemical compositions of the oil samples were found to be highly correlated with changes in physicochemical properties during thermal processing, with the formation of low-molecular-weight polar compounds greatly increasing the acid numbers of the oils.

scholarly journals THE PHYSICOCHEMICAL ANALYSIS OF BIODIESEL PRODUCED FROM AFRICAN SWEET ORANGE (Citrus Sinensis) SEEDS OIL

2020 ◽  
Vol 6 (6) ◽  
pp. 82-91
Author(s):  
M.H.Ibrahim ◽  
D. Y. Dasin ◽  
I.Yahuza
Keyword(s):  
Physicochemical Properties ◽  
Extraction Method ◽  
Pour Point ◽  
Kinematic Viscosity ◽  
Sweet Orange ◽  
Acid Value ◽  
Physicochemical Analysis ◽  
Chemical Extraction ◽  
Fire Point ◽  
Percentage Yield

The research presents experimental study and investigation on the production of biodiesel from African sweet orange seeds oil. The seeds were obtained, sundried, crushed and weighed. Chemical extraction method was used to extract oil from the crushed seeds using soxhlet extractor with n-hexane as a solvent. The physicochemical properties of the oil determined were; flash 1510C, fire point 1730C, acid value 82%, product percentage yield 40% and specific gravity 0.920 at 150C. The production of Biodiesel was carried out through transesterification process from the extracted oil using methanol as catalyst. The results of the physicochemical properties of the produced biodiesel are; Cloud point 60C, Pour point 20C, Flash point 1400C, Density 0.86g/cm and Kinematic viscosity 1.938 mm2/s. The effect of methanol on the yielding of biodiesel at constant ratios of oil and catalyst was determined to be 68% at 10ml, 77% at 9ml and 72% at 7ml. The results obtained are in conformity when compared with ASTM standard D6571 and imply that the African sweet orange seeds oil can be used to produce biodiesel

scholarly journals P PERBANDINGAN KUALITAS PELUMAS MOTOR 4T DI PALEMBANG DENGAN PARAMETER UJI SPECIFIC GRAVITY, KINEMATIC VISCOSITY, FLASH POINT, POUR POINT, TOTAL ACID NUMBER (TAN) DAN VACUUM DISTILLATION

2018 ◽  
Vol 9 (01) ◽  
pp. 39-45
Author(s):  
Dian Kurnia Sari ◽  
Nopitasari Nopitasari
Keyword(s):  
Solvent Extraction ◽  
Specific Gravity ◽  
Pour Point ◽  
Kinematic Viscosity ◽  
Vacuum Distillation ◽  
Mineral Oil ◽  
Acid Number ◽  
Total Acid ◽  
Total Acid Number ◽  
Point Total

Pelumas baik yang berasal dari minyak bumi (mineral oil) atau pelumas sintetik umumnya berupa cairan, yang berfungsi untuk mengurangi gesekan diantara dua benda yang bergerak. Pelumas merupakan bagian yang tak terpisahkan dari mesin. Pelumas dibutuhkan mesin untuk melindungi komponen-komponen mesin dari keausan. Proses pembuatan minyak pelumas adalah distilasi atmosfir, distilasi hampa, deasphalting, solvent extraction, dewaxing, blending dan packaging. Untuk mendapatkan pelumas yang baik perlu ditambahkannya aditif yang sesuai dengan kebutuhan. Aditif adalah senyawa kimia yang bila ditambahkan ke dalam pelumas akan menaikkan unjuk kerja pelumas seperti yang diharapkan. Aditif dapat menentukan mutu pelumas yang digunakan karena dapat merubah sifat kimia maupun sifat fisik dari pelumas. Untuk mengetahui kualitas minyak pelumas diperlukan adanya pengujian sifat fisika dan sifat kimia dari pelumas dengan membandingkan hasil uji dari sampel.

scholarly journals COMPOSITION AND PROPERTIES OF ESSENTIAL OIL OF SIBERIAN FIR ABIES SIBIRICA LDB., GROWING IN DIF-FERENT AREAS OF THE KIROV REGION

2020 ◽  
pp. 291-297
Author(s):  
Evgeniya Sergeyevna Solovyova ◽  
Tat'yana Anatol'yevna Adamovich
Keyword(s):  
Essential Oil ◽  
Physicochemical Properties ◽  
Acid Number ◽  
Raw Material ◽  
Gas Chromatography Mass Spectrometry ◽  
Bornyl Acetate ◽  
Siberian Fir ◽  
Abies Sibirica ◽  
The Village ◽  
Derivatives Of

Siberian fir (Abies sibirica Ldb.) Is a raw material for obtaining valuable essential oil. A change in the composition of the plant's essential oil can serve as a sign of the ecological disadvantage of the territory. The aim of the work was to study the composition and physicochemical properties of Siberian fir essential oil, which grows in different regions of the Kirov region. Sampling sites were distinguished by their location, climate and level of anthropogenic load. Essential oil was obtained by steam distillation. Samples were studied by organoleptic and physicochemical properties, their composition was determined by gas chromatography-mass spectrometry. It was established that the acid number was increased in the obtained oil samples, and oxygen-containing derivatives of terpenes (bornyl acetate) prevailed in their composition. Especially a lot of oxygen-containing substances was found in fir essential oil, which grows in large industrial centers of the region (the cities of Kirov and Kirovo-Chepetsk). The predominance of monoterpene hydrocarbons (camphene, limonene) was found in the composition of fir essential oil from the village of Ilyinskoye. Sesquiterpenoids in the samples were contained in a small amount, and camphor was noted only in the sample of fir oil from the village of Loino. The study confirms the data that with increasing pollution of the territory in the composition of the essential oil of Siberian fir, the share of bornyl acetate and other oxygen-containing compounds begins to increase.

scholarly journals Secondary Metabolic Profile as a Tool for Distinction and Characterization of Cultivars of Black Pepper (Piper nigrum L.) Cultivated in Pará State, Brazil

2021 ◽  
Vol 22 (2) ◽  
pp. 890
Author(s):  
Luccas M. Barata ◽  
Eloísa H. Andrade ◽  
Alessandra R. Ramos ◽  
Oriel F. de Lemos ◽  
William N. Setzer ◽  
...  
Keyword(s):  
Black Pepper ◽  
Plant Diseases ◽  
Gas Chromatography Mass Spectrometry ◽  
Piper Nigrum ◽  
Volatile Components ◽  
Chemical Compositions ◽  
Multivariate Statistical ◽  
Protein Targets ◽  
Fruit Samples ◽  
Sesquiterpene Hydrocarbons

This study evaluated the chemical compositions of the leaves and fruits of eight black pepper cultivars cultivated in Pará State (Amazon, Brazil). Hydrodistillation and gas chromatography–mass spectrometry were employed to extract and analyze the volatile compounds, respectively. Sesquiterpene hydrocarbons were predominant (58.5–90.9%) in the cultivars “Cingapura”, “Equador”, “Guajarina”, “Iaçará”, and “Kottanadan”, and “Bragantina”, “Clonada”, and “Uthirankota” displayed oxygenated sesquiterpenoids (50.6–75.0%). The multivariate statistical analysis applied using volatile composition grouped the samples into four groups: γ-Elemene, curzerene, and δ-elemene (“Equador”/“Guajarina”, I); δ-elemene (“Iaçará”/“Kottanadan”/“Cingapura”, II); elemol (“Clonada”/“Uthirankota”, III) and α-muurolol, bicyclogermacrene, and cubebol (“Bragantina”, IV). The major compounds in all fruit samples were monoterpene hydrocarbons such as α-pinene, β-pinene, and limonene. Among the cultivar leaves, phenolics content (44.75–140.53 mg GAE·g−1 FW), the enzymatic activity of phenylalanine-ammonia lyase (20.19–57.22 µU·mL−1), and carotenoids (0.21–2.31 µg·mL−1) displayed significant variations. Due to black pepper’s susceptibility to Fusarium infection, a molecular docking analysis was carried out on Fusarium protein targets using each cultivar’s volatile components. F. oxysporum endoglucanase was identified as the preferential protein target of the compounds. These results can be used to identify chemical markers related to the susceptibility degree of black pepper cultivars to plant diseases prevalent in Pará State.

scholarly journals The Composition, Physicochemical Properties, Antioxidant Activity, and Sensory Properties of Estonian Honeys

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 511
Author(s):  
Evelin Kivima ◽  
Kristel Tanilas ◽  
Kaie Martverk ◽  
Sirli Rosenvald ◽  
Loreida Timberg ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Invertase Activity ◽  
Water Soluble ◽  
Sensory Characteristics ◽  
Chemical Compositions ◽  
Coumaric Acid ◽  
Total Polyphenol ◽  
Northern Climate ◽  
Sensory Parameters ◽  
Major Amino Acid

Thirty honey samples from different regions of Estonia were investigated to determine the chemical compositions, physicochemical properties, bioactive compounds, and sensory characteristics of typical honeys from a northern climate. The physicochemical parameters, such as electrical conductivity, moisture content, free acidity, hydroxymethylfurfural, diastase, and invertase activity were measured. The color was measured and expressed by L*-, a*-, and b*-coordinates. Sensory parameters were determined by using “fruity”, “floral”, “berry-like”, “herbal”, “woody”, “spicy”, “sweet”, and “animal-like” as the main odor and flavor attributes. The total polyphenol and flavonoid contents were in the range of 26.2–88.7 mg gallic acid equivalents (GAE) per 100 g and 1.9–6.4 mg quercetin equivalents (QE) per 100 g, respectively. The identified polyphenols showed the highest intensities of caffeic acid, coumaric acid, and abscisic acid and its derivatives. The protocatechuic acid intensity was highest in honeys containing traces of honeydew elements and of cinnamic acid and myricetin in heather honey. The water-soluble antioxidant values were 37.8–311.2 mg ascorbic acid equivalents (AAE) per 100 g and the lipid soluble antioxidant values were 14.4–60.7 mg Trolox equivalents (TE) per 100 g. The major amino acid in the analyzed honeys was proline, with variable values depending on the honey’s botanical source. Correlations were calculated based on the results obtained. It was revealed that the typical Estonian honey has floral, berry-like, sweet, and rather mild sensory characteristics. Most of the honeys lacked stronger spicy, woody, and animal-like attributes. The typical color of Estonian honey is quite light.

scholarly journals Phytochemical Analysis and Potential Biological Activities of Essential Oil from Rice Leaf

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 546 ◽  
Author(s):  
Truong Minh ◽  
Tran Xuan ◽  
Truong Van ◽  
Yusuf Andriana ◽  
Tran Viet ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Essential Oil ◽  
Atmospheric Pressure Chemical Ionization ◽  
Biological Activities ◽  
Methyl Ricinoleate ◽  
Gas Chromatography Mass Spectrometry ◽  
Phytochemical Analysis ◽  
Chemical Compositions ◽  
Rice Leaf ◽  
Rice Leaves

Although many investigations on phytochemicals in rice plant parts and root exudates have been conducted, information on the chemical profile of essential oil (EO) and potent biological activities has been limited. In this study, chemical compositions of rice leaf EO and in vitro biological activities were investigated. From 1.5 kg of fresh rice leaves, an amount of 20 mg EO was obtained by distillation and analyzed by gas chromatography-mass spectrometry (GC-MS), electrospray ionization (ESI), and atmospheric pressure chemical ionization (APCI) to reveal the presence of twelve volatile constituents, of which methyl ricinoleate (27.86%) was the principal compound, followed by palmitic acid (17.34%), and linolenic acid (11.16%), while 2-pentadecanone was the least (2.13%). Two phytoalexin momilactones A and B were first time identified in EO using ultra-performance liquid chromatography coupled with electrospray mass spectrometry (UPLC/ESI-MS) (9.80 and 4.93 ng/g fresh weight, respectively), which accounted for 7.35% and 3.70% of the EO, respectively. The assays of DPPH (IC50 = 73.1 µg/mL), ABTS (IC50 = 198.3 µg/mL), FRAP (IC50 = 700.8 µg/mL) and β-carotene oxidation (LPI = 79%) revealed that EO possessed an excellent antioxidant activity. The xanthine oxidase assay indicated that the anti-hyperuricemia potential was in a moderate level (IC50 = 526 µg/mL) as compared with the standard allopurinol. The EO exerted potent inhibition on growth of Raphanus sativus, Lactuca sativa, and two noxious weeds Echinochloa crus-galli, and Bidens pilosa, but in contrast, the growth of rice seedlings was promoted. Among the examined plants, the growth of the E. crus-galli root was the most inhibited, proposing that constituents found in EO may have potential for the control of the problematic paddy weed E. crus-galli. It was found that the EO of rice leaves contained rich phytochemicals, which were potent in antioxidants and gout treatment, as well as weed management. Findings of this study highlighted the potential value of rice leaves, which may provide extra benefits for rice farmers.

Effects of age and food source on secondary chemistry of larvae of Lymantria species (Lepidoptera: Lymantriidae)

2004 ◽  
Vol 94 (2) ◽  
pp. 137-143 ◽  
Author(s):  
R. Deml
Keyword(s):  
Secondary Metabolites ◽  
Developmental Stages ◽  
Secondary Compounds ◽  
Food Plants ◽  
Gas Chromatography Mass Spectrometry ◽  
Chemical Compositions ◽  
Clustering Methods ◽  
Single Linkage ◽  
Secondary Chemistry ◽  
Dissimilarity Coefficients

AbstractHaemolymph and osmeterial secretions of caterpillars of Lymantria monacha (Linnaeus) and L. concolor Walker were analysed by gas chromatography/mass spectrometry for low molecular weight secondary metabolites. The similarities of their chemical compositions were determined by means of cluster analysis techniques in order to characterize possible chemical variations related to developmental stage or food of the larvae. For this purpose, two dissimilarity coefficients (Euclidean distances, Canberra metrics) and four clustering methods (UPGMA, WPGMA, WPGMC, single linkage) were combined. The patterns of secondary compounds obtained from the haemolymph and osmeterial secretions studied did not differ statistically significantly between two groups of L. monacha larvae fed with either larch, Larix decidua Mil., or Norway spruce, Picea abies (L.), indicating no relevant influence of plant chemistry. However, haemolymph of penultimate instar larvae of L. concolor fed on Rhododendroncontained a mixture of compounds differing statistically significantly from that of last instar caterpillars. The total compositions of the corresponding gland secretions were statistically identical though the presence/amounts of individual compounds varied. This suggested that the haemolymph composition reflected changing physiological requirements of the successive instars, whereas the composition of the defensive mixtures remained comparatively constant, possibly due to a constant spectrum of potential enemies. A more pronounced age-dependence of larval chemistry was shown by a similar analysis of data from various developmental stages of L. dispar (Linnaeus) and one of its food plants. This analysis suggested plant composition affected the secondary chemistry of early larval instars of L. dispar. The results are discussed in terms of the roles of secondary metabolites in defence against natural enemies.

scholarly journals Investigation on the Mass Distribution and Chemical Compositions of Various Ionic Liquids-Extracted Coal Fragments and Their Effects on the Electrochemical Performance of Coal-Derived Carbon Nanofibers (CCNFs)

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 664
Author(s):  
Shuai Tan ◽  
Theodore John Kraus ◽  
Mitchell Ross Helling ◽  
Rudolph Kurtzer Mignon ◽  
Franco Basile ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Electrochemical Performance ◽  
Carbon Nanofibers ◽  
Mass Distribution ◽  
Electrode Materials ◽  
Gas Chromatography Mass Spectrometry ◽  
Electrochemical Performances ◽  
Diffusion Resistance ◽  
Chemical Compositions ◽  
Holistic Understanding

Coal-derived carbon nanofibers (CCNFs) have been recently found to be a promising and low-cost electrode material for high-performance supercapacitors. However, the knowledge gap still exists between holistic understanding of coal precursors derived from different solvents and resulting CCNFs’ properties, prohibiting further optimization of their electrochemical performance. In this paper, assisted by laser desorption/ionization (LDI) and gas chromatography–mass spectrometry (GC–MS) technologies, a systematic study was performed to holistically characterize mass distribution and chemical composition of coal precursors derived from various ionic liquids (ILs) as extractants. Sequentially, X-ray photoelectron spectroscopy (XPS) revealed that the differences in chemical properties of various coal products significantly affected the surface oxygen concentrations and certain species distributions on the CCNFs, which, in turn, determined the electrochemical performances of CCNFs as electrode materials. We report that the CCNF that was produced by an oxygen-rich coal fragment from C6mimCl ionic liquid extraction showed the highest concentrations of quinone and ester groups on the surface. Consequentially, C6mimCl-CCNF achieved the highest specific capacitance and lowest ion diffusion resistance. Finally, a symmetric carbon/carbon supercapacitor fabricated with such CCNF as electrode delivered an energy density of 21.1 Wh/kg at the power density of 0.6 kW/kg, which is comparable to commercial active carbon supercapacitors.

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