Rapeseed(Brassica napus L.)harvesting method is critical since it significantly determines the seed yield,oil quality,and industrial efficiency.This study investigated the influences of harvesting methods on the quali...Rapeseed(Brassica napus L.)harvesting method is critical since it significantly determines the seed yield,oil quality,and industrial efficiency.This study investigated the influences of harvesting methods on the quality of cold-pressed rapeseed oil of two varieties.Oil color,peroxide value(POV),tocopherol content,fatty acid composition,and polarity of total polyphenols(PTP)contents of two rapeseed varieties in Huanggang and Xiangyang were compared through artificially simulated combined harvesting and two-stage harvesting.Results showed significant differences in the quality of rapeseed oil between the two harvesting methods.The red value(R-value),POV,total tocopherol contents,linoleic and linolenic acid content,and PTP content of the pressed rapeseed oil prepared by the combined harvesting method were about 27.6,5.7,15.8,2.0,0.5,and 28.6%lower than those of the oil produced from the two-stage harvesting method,respectively.Xiangyang and Huayouza62 performed better in the two regions and two varieties,respectively.To sum up,the rapeseed oil obtained 41–44 days after final flowering of combined harvesting,35 days after final flowering,and six days of post-ripening of the two-stage harvesting had the best quality.展开更多
The rapeseed oil extracted from the mature seeds was purified by refining processing,and the rheological characteristic analysis of the viscosity and dynamic shear rate at gradient temperatures was made.The result sho...The rapeseed oil extracted from the mature seeds was purified by refining processing,and the rheological characteristic analysis of the viscosity and dynamic shear rate at gradient temperatures was made.The result shows that at 20,40,60 and 80 ℃ respectively,when the shear rate gradually rises,the torque increases accordingly but its viscosity does not vary distinctly.The result suggests that when rapeseed oil is used as the raw of edible oils and industries,the working procedures at high temperature will not influence its rheological characteristic distinctly.展开更多
Oleic acid-capped lanthanum borate(abbreviated as OA/La BO_3·H_2O) nanosheets were prepared by the hydrothermal method. The microstructures of as-prepared OA/La BO_3·H_2O were characterized by means of SEM, ...Oleic acid-capped lanthanum borate(abbreviated as OA/La BO_3·H_2O) nanosheets were prepared by the hydrothermal method. The microstructures of as-prepared OA/La BO_3·H_2O were characterized by means of SEM, TEM, EDS, FTIR and XRD, respectively. Moreover, the friction and wear properties of OA/La BO_3·H_2O as a lubricant additive in rapeseed oil were evaluated on a four-ball tribotester. The tribochemical characteristics of worn surfaces were investigated by SEM and XPS. The results showed that the hydrophobic OA/La BO_3·H_2O nanosheets exhibited their morphology with a diameter in the range of 100 nm to 300 nm and a thickness of about 25 nm, and displayed excellent dispersing stability in rapeseed oil. In the meantime, the rapeseed oil doped with OA/La BO_3·H_2O nanosheets markedly decreased the friction and wear of steel balls, and the optimal friction-reducing and antiwear ability of rapeseed oil was obtained at an OA/La BO_3·H_2O content of 1.0%. The outstanding tribological performance of OA/La BO_3·H_2O in rapeseed oil was attributed to the formation of a composite boundary lubrication film mainly composed of lubricious tribochemical species of B_2O_3, La_2O_3 and Fe_2O_3, and deposits of OA/La BO_3·H_2O nanosheets as well as the adsorbates of rapeseed oil on rubbed surfaces.展开更多
A BN-containing additive,the boron and nitrogen modified rapeseed oil (abbreviated as BNR),was prepared by chemical modification of rapeseed oil with boric and nitrous compounds.The friction and wear performances of t...A BN-containing additive,the boron and nitrogen modified rapeseed oil (abbreviated as BNR),was prepared by chemical modification of rapeseed oil with boric and nitrous compounds.The friction and wear performances of the AZ91D magnesium alloy against the GCr15 bearing steel under lubrication of rapeseed oil containing BNR were evaluated on a SRV tribotester.The topography and chemical species of the worn surfaces of magnesium alloy were analyzed by a scanning electron microscope (SEM) and an X-ray photoelectron spectroscope (XPS),respectively.The test results indicated that the friction and wear of the magnesium alloy-steel tribomates could be effectively reduced by incorporating BNR into the rapeseed oil lubricant.The friction coefficients and the wear scars of magnesium alloy decreased with an increasing content of BNR.The surface lubricated with the BNR-doped rapeseed oil demonstrated less wear as compared with that lubricated with neat rapeseed oil.The enhanced anti-wear and friction-reducing abilities of rapeseed oil provided by BNR in the lubrication of magnesium alloy against steel were ascribed to the formation of a composite boundary lubrication film due to the strong adsorption of BNR and rapeseed oil onto the lubricated surfaces and their tribochemical reactions with magnesium alloy.展开更多
Early investigations of dielectric permittivity of rigid polyurethane foams at low frequencies were made on petrochemical-origin foams,mainly by means of parallel plate capacitors.In the present investigation biopolyo...Early investigations of dielectric permittivity of rigid polyurethane foams at low frequencies were made on petrochemical-origin foams,mainly by means of parallel plate capacitors.In the present investigation biopolyol was synthesized from Latvia-grown rapeseeds’oil by the transesterification method with triethanolamine,in an environmentally friendly process,without emission of harmful substances,at temperatures 175℃±5℃.Rigid,closed-cell rapeseed oil polyol polyurethane biofoams and petrochemical foams were made ensuring content of the renewable rapeseed oil polyol in ready foams 27 wt.%–29 wt.%.Dielectric permittivity of the polyurethane foams and the underlying monolithic petrochemical-origin polyurethane and biopolyurethane was measured with a non-destructive dielectric spectrometer equipped with a capacitive sensor of one-side access type at 16 discrete frequencies distributed geometrically over the band 10 Hz,…,330 kHz.Permittivity value of the gaseous phase in the closed-cells was estimated to beεg≈1.001 that corresponds to the values,characteristic for the most of gases.Dielectric permittivity of petrochemical polyurethane foams and the mentioned biofoams was compared with permittivity of polyurethane foams from industrial producers Sika JSC and General Plastics Manufacturing Co.Polyurethane foams of the developed formulation exhibit competitive,low dielectric permittivity,not exceeding that of the foams from industrial producers:petrochemical foams up to 550 kg/m^(3) and the mentioned biofoams,comprising the renewable rapeseed oil polyol,up to densities 230–250 kg/m^(3).Considering petrochemical-origin polyurethane foams as a heterogeneous media“Polymer—gaseous phase”,the applicability of the rule of mixture and Maxwell–Garnett equation to model mathematically the dependence of effective dielectric permittivity on the volume fraction of phases was showed.展开更多
A new type of environmentally friendly lube additive-amide type modified rapeseed oil was synthesized and characterized by infrared spectrum. Its effect on the friction and wear behavior of steel-steel and steel-alumi...A new type of environmentally friendly lube additive-amide type modified rapeseed oil was synthesized and characterized by infrared spectrum. Its effect on the friction and wear behavior of steel-steel and steel-aluminum alloy systems were investigated with a four-ball machine and an Optimol SRV friction and wear tester respectively.The morphographies of the worn surfaces were analyzed by means of scanning electron microscopy(SEM). The worn surfaces of the 2024Al alloy block were analyzed by means of X-ray photoelectron spectroscopy(XPS). The results show that the modified rapeseed oil as additives can obviously decrease the wear rate and friction coefficient of steel pair and steel-aluminum frictional pair. Its lubrication mechanism is inferred that a high strength complex protection films form on the worn surface of the Al alloy due to the adsorption or tribochemistry reaction of a long chain additive molecule and high reaction activity of N element.展开更多
Rapeseed is widely grown in China as an important oil crop. In this study, Shotgun lipidomic methodology based on tandem mass spectrometry but without liquid chromatography was established for simple lipids analysis s...Rapeseed is widely grown in China as an important oil crop. In this study, Shotgun lipidomic methodology based on tandem mass spectrometry but without liquid chromatography was established for simple lipids analysis such as mono-, di-and triacylglycerols(MAGs, DAGs and TAGs) and the derivatives such as free fatty acids(FFAs). Six varieties of rapeseeds belonging to 3 types(B. juncea, B. campestris and B. oleracea) from different areas of China were investigated, with 59 TAG species, 10 DAG species, 5 MAG species and 6 FFA species identified. It was found that erucic acid was mainly present in the form of TAG 62:4(22:1/18:2/22:1), TAG 62:3(22:1/18:1/22:1), and TAG 62:5(22:1/18:3/22:1) in high erucic acid rapeseed oils, while oleic acid was mainly present in the form of TAG 54:2(18:0/18:1/18:1), and TAG 54:4(18:1/18:2/18:1) in high oleic acid rapeseed oils. It was difficult for DAG, MAG and FFA quantification due to their low content with high background content of TAGs. Results showed that the main differences in lipids were not derived from the types of rapeseed, but directly related to varieties.展开更多
This study proposed a strategy based on simple chemical derivatization coupled with neutral loss scan tandem to electrospray ionization source of mass spectrometer (NLS-ESI-MS/MS) for rapid and sensitive detection of ...This study proposed a strategy based on simple chemical derivatization coupled with neutral loss scan tandem to electrospray ionization source of mass spectrometer (NLS-ESI-MS/MS) for rapid and sensitive detection of free fatty acids (FFAs) in coldpressed rapeseed oils without sample purification and enrichment. The method was applied to investigate contents of FFAs and their changes in cold-pressed rapeseed oil pretreated by microwave. Results showed that main FFAs in rapeseed oil control samples were myristic acid (C14:0), palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2) and linolenic acid (C18:3). The highest content of C18:1 was 7163.69 nmol/g and C18:2 was 5221.18 nmol/g among 8 oil samples. FFAs generally increased after microwave pretreatment except C14:0 in oil sample of ‘Xinyou 17’ and ‘Suyou 6’. C18:1 and C18:2 significantly changed (P<0.05) after microwave pretreatment. With this established simple,practical and reliable analysis approach, changes of FFAs would be monitored to ensure safety and quality of edible oils. A powerful tool is provided for thermal degradation mechanism research of edible oils.展开更多
Considering electromagnetic effect when investigating tribological properties of rapeseed oil is benefical not only to the improvement of green lubrication, but also to the development of tribology theories and practi...Considering electromagnetic effect when investigating tribological properties of rapeseed oil is benefical not only to the improvement of green lubrication, but also to the development of tribology theories and practices. In the present paper, the tribological properties of rapeseed oil under different intensity of electromagnetic field and normal loads were evaluated on a modified tribo-tester. The results indicated that the electromagnetic field could improve the anti-wear and friction-reducing property of the rapeseed oil. Furthermore, the influencing mechanisms were discussed from the perspective of electromagnetism according to the analytical results of SEM, EDS and XPS techniques.展开更多
The effects of sulfur type additives T321 and phosphorous type additives P120 on the EP and AW abilities of rapeseed oil were investigated by a four-ball testing machine using the rapeseed oil as base oil.The effect o...The effects of sulfur type additives T321 and phosphorous type additives P120 on the EP and AW abilities of rapeseed oil were investigated by a four-ball testing machine using the rapeseed oil as base oil.The effect of T321 mixed with P120 on the tribochemical performance of the rapeseed oil was studied.The result shows that the load carrying,extreme pressure and abrasion capacities of lubricant film can be improved by adding T321 and P120 as additives in rapeseed oil, respectively. The SEDX analysis on the surface of steel balls reveals that tribochemical reactions occur during the friction process, the barrier lubricating film is formed containing triglyceride and the additives can improve the anti-wear ability and load-carrying capacity.展开更多
The objective of the present study is to examine and compare the performance and emission characteristic of two biodiesel fuels produced from rapeseed oil via transesterification method.Tested biodiesel fuels(ROME(Rap...The objective of the present study is to examine and compare the performance and emission characteristic of two biodiesel fuels produced from rapeseed oil via transesterification method.Tested biodiesel fuels(ROME(Rapeseed Oil Methyl Ester)and ROEE(Rapeseed Oil Ethyl Ester))were selected based on their properties obtained from an optimization of transesterification conditions.A Yanmar diesel engine has led to evaluating their performance parameters such as fuel consumption rate,exhaust gas temperature and emission characteristic corresponding to nitrogen oxides(NOx),carbone monoxide(CO)and carbon dioxide(CO2).A comparative analysis was carried out using normal diesel fuel tested in same experimental conditions.Fuel consumption rate was measured by observing the volumetric rate from the fuel tank of the engine supported by stopwatch.The exhaust gas temperature and emission characteristic were measured simultaneously by using a testo 350 flue gas analyzer.According to the results,biodiesel fuels showed a higher fuel consumption rate and exhaust gas temperature under an increase of engine speed.They also exhibited lower NOx emission with a slight rise in CO and CO2 emission compared to mineral diesel fuel.ROME exhibited low emission gas compared to ROEE and mineral diesel.It can be evaluated as a promising alternative fuel for diesel engine.展开更多
A novel lubricating oil additive 3-((2-(2-hydroxyethyl)-1,3,2,6-dioxazaborocan-6-yloxy)methyl) benzo[d] thiazole-2(3H)-thione(BTD) was synthesized.The product was characterized by FTIR,elemental analysis,and thermogra...A novel lubricating oil additive 3-((2-(2-hydroxyethyl)-1,3,2,6-dioxazaborocan-6-yloxy)methyl) benzo[d] thiazole-2(3H)-thione(BTD) was synthesized.The product was characterized by FTIR,elemental analysis,and thermogravimetric analysis(TGA).Four-ball tribological tests showed that the addition of a definite concentration of this additive to rapeseed oil could effectively increase both the load-carrying capacity,resistance to wear,and friction-reducing abilities of the oil.Scanning electron microscopy(SEM) observations have confirmed that the additive could result in a reduced diameter of the wear scar.展开更多
In this study,biodiesel fuel was produced from rapeseed oil via transesterification method.The optimum reaction conditions were determined by varying alcohol type and its concentration considering their influence on t...In this study,biodiesel fuel was produced from rapeseed oil via transesterification method.The optimum reaction conditions were determined by varying alcohol type and its concentration considering their influence on the yield and properties of produced biodiesel.Methanol and ethanol were alcohol used in the transesterification process.The density of biodiesel was measured at 15℃according to EN ISO 12185 test method and its viscosity was determined at 40℃by using a Brookfield digital viscometer(DV-II+Pro).Shimadzu Auto-Calculating Bomb calorimeter CA-4AJ was used to measure the high heating value.The optimum transesterification conditions found were alcohol:oil ratio of 18:1,1%of potassium hydroxide as catalyst,60 min of reaction time,60℃of reaction temperature and stirring speed of 650 rpm.Biodiesel properties under these conditions satisfied the regulatory standards and are slightly similar to those of mineral diesel tested in same conditions.Using methanol gives better results compared to ethanol.展开更多
To investigate advantages of microwave pretreatment for oil storage, oxidative stability of pressed rapeseed oil with microwave pretreatment (M-RO) was evaluated, while pressed rapeseed oil (RO) and RO with 200 ppm te...To investigate advantages of microwave pretreatment for oil storage, oxidative stability of pressed rapeseed oil with microwave pretreatment (M-RO) was evaluated, while pressed rapeseed oil (RO) and RO with 200 ppm tertiary butylhydroquinone added (T-RO) were used for comparison. Oil samples were collected after accelerated storage at 60oC in dark for 0-32 d. A total of 37 oxidized volatile compounds were identified and 9 typical key compounds were quantified by solid-phase microextraction gas chromatography/mass spectrometry (HS-SPME-GC/MS). Correlation analysis showed that lipid oxidation parameters and induction time (IP) had significant association with typical indicators of volatile oxidized compounds. Hexanal and (E,E)-2,4-heptadienal were most suitable for differentiating RO sample at different storage times while 1-hexanol, 1-heptanal and (E)-2-octenal were suitable for T-RO sample. To M-RO sample, 5 substances described above together can provide a guide for monitoring lipid oxidation. M-RO has better oxidation resistance than RO, with advantage of 4 d in accelerated conditions both in sensory evaluation and PCA analysis. However, it still produces more volatile oxidized compounds and has higher peroxide value (PV) and p-anisidine value (p-AV) than T-RO sample at any sampling point. Anti-oxidation efficiency of rapeseed oil can be promoted via microwave pretreatment. This work provid new clues of benefits about microwave pretreatment in oil storage.展开更多
Nickel(Ni)nanoparticles can be enriched on the surface of iron-based frictional pairs,which provides the possibility to get rid of the competitive adsorption between the polar species of vegetable oil and the surface-...Nickel(Ni)nanoparticles can be enriched on the surface of iron-based frictional pairs,which provides the possibility to get rid of the competitive adsorption between the polar species of vegetable oil and the surface-active nano-additives thereon.In this paper,nickel acetylacetonate was used as a precursor to in-situ synthesize nickel nanoparticles with an average diameter of about 12 nm in rapeseed oil(RO)as the reducing agent,surface modifier,and solvent as well.The tribological properties of the as-synthesized Ni nanoparticles were evaluated with a four-ball tribometer,and their tribomechanism was investigated based on the characterizations of the tribofilm on rubbed steel surfaces by the scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).It was found that the Ni nanoparticles in-situ prepared in the RO with a mass fraction of 0.3%can reduce the wear scar diameter(WSD)of the steel ball by 36%.This is because,on the one hand,the Ni nanoparticles are adsorbed on the rubbed steel surfaces to repair or fill up the micro-pits and grooves thereon.On the other hand,Ni nanoparticles participate in tribochemical reactions with atmospheric O and steel substrate to form the tribochemical reaction film on the rubbed steel surfaces with the assistance of friction-induced heat and applied normal load.In addition,an amorphous carbon film is formed on the rubbed surface via the carbonization of base oil under the catalysis of Ni nanoparticles.The adsorbed Ni layer,the tribochemical reaction film,and the carbon layer comprise a composite tribofilm composed of amorphous carbon,polar fatty acid,metallic nickel,iron oxides,and nickel oxides on the rubbed steel surfaces,which contributes to significantly improving the antiwear ability and load-carrying capacity of the RO for the steel-steel sliding pair.展开更多
基金supported by the National Key R&D Program of China(2021YFD1600502).
文摘Rapeseed(Brassica napus L.)harvesting method is critical since it significantly determines the seed yield,oil quality,and industrial efficiency.This study investigated the influences of harvesting methods on the quality of cold-pressed rapeseed oil of two varieties.Oil color,peroxide value(POV),tocopherol content,fatty acid composition,and polarity of total polyphenols(PTP)contents of two rapeseed varieties in Huanggang and Xiangyang were compared through artificially simulated combined harvesting and two-stage harvesting.Results showed significant differences in the quality of rapeseed oil between the two harvesting methods.The red value(R-value),POV,total tocopherol contents,linoleic and linolenic acid content,and PTP content of the pressed rapeseed oil prepared by the combined harvesting method were about 27.6,5.7,15.8,2.0,0.5,and 28.6%lower than those of the oil produced from the two-stage harvesting method,respectively.Xiangyang and Huayouza62 performed better in the two regions and two varieties,respectively.To sum up,the rapeseed oil obtained 41–44 days after final flowering of combined harvesting,35 days after final flowering,and six days of post-ripening of the two-stage harvesting had the best quality.
基金Project(2007CB210201) supported by Major State Basic Research Development Program of ChinaProject(07JJ6053) supported by Hunan Provincial Natural Science Foundation of China
文摘The rapeseed oil extracted from the mature seeds was purified by refining processing,and the rheological characteristic analysis of the viscosity and dynamic shear rate at gradient temperatures was made.The result shows that at 20,40,60 and 80 ℃ respectively,when the shear rate gradually rises,the torque increases accordingly but its viscosity does not vary distinctly.The result suggests that when rapeseed oil is used as the raw of edible oils and industries,the working procedures at high temperature will not influence its rheological characteristic distinctly.
基金the financial support of the National Natural Science Foundation of China(Project 50975282)
文摘Oleic acid-capped lanthanum borate(abbreviated as OA/La BO_3·H_2O) nanosheets were prepared by the hydrothermal method. The microstructures of as-prepared OA/La BO_3·H_2O were characterized by means of SEM, TEM, EDS, FTIR and XRD, respectively. Moreover, the friction and wear properties of OA/La BO_3·H_2O as a lubricant additive in rapeseed oil were evaluated on a four-ball tribotester. The tribochemical characteristics of worn surfaces were investigated by SEM and XPS. The results showed that the hydrophobic OA/La BO_3·H_2O nanosheets exhibited their morphology with a diameter in the range of 100 nm to 300 nm and a thickness of about 25 nm, and displayed excellent dispersing stability in rapeseed oil. In the meantime, the rapeseed oil doped with OA/La BO_3·H_2O nanosheets markedly decreased the friction and wear of steel balls, and the optimal friction-reducing and antiwear ability of rapeseed oil was obtained at an OA/La BO_3·H_2O content of 1.0%. The outstanding tribological performance of OA/La BO_3·H_2O in rapeseed oil was attributed to the formation of a composite boundary lubrication film mainly composed of lubricious tribochemical species of B_2O_3, La_2O_3 and Fe_2O_3, and deposits of OA/La BO_3·H_2O nanosheets as well as the adsorbates of rapeseed oil on rubbed surfaces.
基金the financial support from the National Natural Science Foundation of China (project No. 50975282)
文摘A BN-containing additive,the boron and nitrogen modified rapeseed oil (abbreviated as BNR),was prepared by chemical modification of rapeseed oil with boric and nitrous compounds.The friction and wear performances of the AZ91D magnesium alloy against the GCr15 bearing steel under lubrication of rapeseed oil containing BNR were evaluated on a SRV tribotester.The topography and chemical species of the worn surfaces of magnesium alloy were analyzed by a scanning electron microscope (SEM) and an X-ray photoelectron spectroscope (XPS),respectively.The test results indicated that the friction and wear of the magnesium alloy-steel tribomates could be effectively reduced by incorporating BNR into the rapeseed oil lubricant.The friction coefficients and the wear scars of magnesium alloy decreased with an increasing content of BNR.The surface lubricated with the BNR-doped rapeseed oil demonstrated less wear as compared with that lubricated with neat rapeseed oil.The enhanced anti-wear and friction-reducing abilities of rapeseed oil provided by BNR in the lubrication of magnesium alloy against steel were ascribed to the formation of a composite boundary lubrication film due to the strong adsorption of BNR and rapeseed oil onto the lubricated surfaces and their tribochemical reactions with magnesium alloy.
文摘Early investigations of dielectric permittivity of rigid polyurethane foams at low frequencies were made on petrochemical-origin foams,mainly by means of parallel plate capacitors.In the present investigation biopolyol was synthesized from Latvia-grown rapeseeds’oil by the transesterification method with triethanolamine,in an environmentally friendly process,without emission of harmful substances,at temperatures 175℃±5℃.Rigid,closed-cell rapeseed oil polyol polyurethane biofoams and petrochemical foams were made ensuring content of the renewable rapeseed oil polyol in ready foams 27 wt.%–29 wt.%.Dielectric permittivity of the polyurethane foams and the underlying monolithic petrochemical-origin polyurethane and biopolyurethane was measured with a non-destructive dielectric spectrometer equipped with a capacitive sensor of one-side access type at 16 discrete frequencies distributed geometrically over the band 10 Hz,…,330 kHz.Permittivity value of the gaseous phase in the closed-cells was estimated to beεg≈1.001 that corresponds to the values,characteristic for the most of gases.Dielectric permittivity of petrochemical polyurethane foams and the mentioned biofoams was compared with permittivity of polyurethane foams from industrial producers Sika JSC and General Plastics Manufacturing Co.Polyurethane foams of the developed formulation exhibit competitive,low dielectric permittivity,not exceeding that of the foams from industrial producers:petrochemical foams up to 550 kg/m^(3) and the mentioned biofoams,comprising the renewable rapeseed oil polyol,up to densities 230–250 kg/m^(3).Considering petrochemical-origin polyurethane foams as a heterogeneous media“Polymer—gaseous phase”,the applicability of the rule of mixture and Maxwell–Garnett equation to model mathematically the dependence of effective dielectric permittivity on the volume fraction of phases was showed.
基金Project supported by the National Natural Science Foundation of China
文摘A new type of environmentally friendly lube additive-amide type modified rapeseed oil was synthesized and characterized by infrared spectrum. Its effect on the friction and wear behavior of steel-steel and steel-aluminum alloy systems were investigated with a four-ball machine and an Optimol SRV friction and wear tester respectively.The morphographies of the worn surfaces were analyzed by means of scanning electron microscopy(SEM). The worn surfaces of the 2024Al alloy block were analyzed by means of X-ray photoelectron spectroscopy(XPS). The results show that the modified rapeseed oil as additives can obviously decrease the wear rate and friction coefficient of steel pair and steel-aluminum frictional pair. Its lubrication mechanism is inferred that a high strength complex protection films form on the worn surface of the Al alloy due to the adsorption or tribochemistry reaction of a long chain additive molecule and high reaction activity of N element.
基金supported by National Natural Science Foundation of China(Grant No 21105119)Research Foundation of the Director General of Oil Crops Research Institute,Chinese Academy of Agricultural Sciences
文摘Rapeseed is widely grown in China as an important oil crop. In this study, Shotgun lipidomic methodology based on tandem mass spectrometry but without liquid chromatography was established for simple lipids analysis such as mono-, di-and triacylglycerols(MAGs, DAGs and TAGs) and the derivatives such as free fatty acids(FFAs). Six varieties of rapeseeds belonging to 3 types(B. juncea, B. campestris and B. oleracea) from different areas of China were investigated, with 59 TAG species, 10 DAG species, 5 MAG species and 6 FFA species identified. It was found that erucic acid was mainly present in the form of TAG 62:4(22:1/18:2/22:1), TAG 62:3(22:1/18:1/22:1), and TAG 62:5(22:1/18:3/22:1) in high erucic acid rapeseed oils, while oleic acid was mainly present in the form of TAG 54:2(18:0/18:1/18:1), and TAG 54:4(18:1/18:2/18:1) in high oleic acid rapeseed oils. It was difficult for DAG, MAG and FFA quantification due to their low content with high background content of TAGs. Results showed that the main differences in lipids were not derived from the types of rapeseed, but directly related to varieties.
文摘This study proposed a strategy based on simple chemical derivatization coupled with neutral loss scan tandem to electrospray ionization source of mass spectrometer (NLS-ESI-MS/MS) for rapid and sensitive detection of free fatty acids (FFAs) in coldpressed rapeseed oils without sample purification and enrichment. The method was applied to investigate contents of FFAs and their changes in cold-pressed rapeseed oil pretreated by microwave. Results showed that main FFAs in rapeseed oil control samples were myristic acid (C14:0), palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2) and linolenic acid (C18:3). The highest content of C18:1 was 7163.69 nmol/g and C18:2 was 5221.18 nmol/g among 8 oil samples. FFAs generally increased after microwave pretreatment except C14:0 in oil sample of ‘Xinyou 17’ and ‘Suyou 6’. C18:1 and C18:2 significantly changed (P<0.05) after microwave pretreatment. With this established simple,practical and reliable analysis approach, changes of FFAs would be monitored to ensure safety and quality of edible oils. A powerful tool is provided for thermal degradation mechanism research of edible oils.
基金financially supported by the National Natural Science Foundation of China (Project No. 51375491)the Natural Science Foundation of Chongqing(Project No. CSTC, 2014JCYJAA50021)the Youth Fund of Logistical Engineering University (No. YQ16-420801)
文摘Considering electromagnetic effect when investigating tribological properties of rapeseed oil is benefical not only to the improvement of green lubrication, but also to the development of tribology theories and practices. In the present paper, the tribological properties of rapeseed oil under different intensity of electromagnetic field and normal loads were evaluated on a modified tribo-tester. The results indicated that the electromagnetic field could improve the anti-wear and friction-reducing property of the rapeseed oil. Furthermore, the influencing mechanisms were discussed from the perspective of electromagnetism according to the analytical results of SEM, EDS and XPS techniques.
文摘The effects of sulfur type additives T321 and phosphorous type additives P120 on the EP and AW abilities of rapeseed oil were investigated by a four-ball testing machine using the rapeseed oil as base oil.The effect of T321 mixed with P120 on the tribochemical performance of the rapeseed oil was studied.The result shows that the load carrying,extreme pressure and abrasion capacities of lubricant film can be improved by adding T321 and P120 as additives in rapeseed oil, respectively. The SEDX analysis on the surface of steel balls reveals that tribochemical reactions occur during the friction process, the barrier lubricating film is formed containing triglyceride and the additives can improve the anti-wear ability and load-carrying capacity.
基金This work was supported by the JICA(Japan International Cooperation Agency)through the program of ABE Initiative(African Business Education Initiative for Youth)and the collaboration with Kumamoto University.
文摘The objective of the present study is to examine and compare the performance and emission characteristic of two biodiesel fuels produced from rapeseed oil via transesterification method.Tested biodiesel fuels(ROME(Rapeseed Oil Methyl Ester)and ROEE(Rapeseed Oil Ethyl Ester))were selected based on their properties obtained from an optimization of transesterification conditions.A Yanmar diesel engine has led to evaluating their performance parameters such as fuel consumption rate,exhaust gas temperature and emission characteristic corresponding to nitrogen oxides(NOx),carbone monoxide(CO)and carbon dioxide(CO2).A comparative analysis was carried out using normal diesel fuel tested in same experimental conditions.Fuel consumption rate was measured by observing the volumetric rate from the fuel tank of the engine supported by stopwatch.The exhaust gas temperature and emission characteristic were measured simultaneously by using a testo 350 flue gas analyzer.According to the results,biodiesel fuels showed a higher fuel consumption rate and exhaust gas temperature under an increase of engine speed.They also exhibited lower NOx emission with a slight rise in CO and CO2 emission compared to mineral diesel fuel.ROME exhibited low emission gas compared to ROEE and mineral diesel.It can be evaluated as a promising alternative fuel for diesel engine.
基金supported by the Ministry of Education of Hunan province (09C161,10C0464,and 09C162)
文摘A novel lubricating oil additive 3-((2-(2-hydroxyethyl)-1,3,2,6-dioxazaborocan-6-yloxy)methyl) benzo[d] thiazole-2(3H)-thione(BTD) was synthesized.The product was characterized by FTIR,elemental analysis,and thermogravimetric analysis(TGA).Four-ball tribological tests showed that the addition of a definite concentration of this additive to rapeseed oil could effectively increase both the load-carrying capacity,resistance to wear,and friction-reducing abilities of the oil.Scanning electron microscopy(SEM) observations have confirmed that the additive could result in a reduced diameter of the wear scar.
文摘In this study,biodiesel fuel was produced from rapeseed oil via transesterification method.The optimum reaction conditions were determined by varying alcohol type and its concentration considering their influence on the yield and properties of produced biodiesel.Methanol and ethanol were alcohol used in the transesterification process.The density of biodiesel was measured at 15℃according to EN ISO 12185 test method and its viscosity was determined at 40℃by using a Brookfield digital viscometer(DV-II+Pro).Shimadzu Auto-Calculating Bomb calorimeter CA-4AJ was used to measure the high heating value.The optimum transesterification conditions found were alcohol:oil ratio of 18:1,1%of potassium hydroxide as catalyst,60 min of reaction time,60℃of reaction temperature and stirring speed of 650 rpm.Biodiesel properties under these conditions satisfied the regulatory standards and are slightly similar to those of mineral diesel tested in same conditions.Using methanol gives better results compared to ethanol.
文摘To investigate advantages of microwave pretreatment for oil storage, oxidative stability of pressed rapeseed oil with microwave pretreatment (M-RO) was evaluated, while pressed rapeseed oil (RO) and RO with 200 ppm tertiary butylhydroquinone added (T-RO) were used for comparison. Oil samples were collected after accelerated storage at 60oC in dark for 0-32 d. A total of 37 oxidized volatile compounds were identified and 9 typical key compounds were quantified by solid-phase microextraction gas chromatography/mass spectrometry (HS-SPME-GC/MS). Correlation analysis showed that lipid oxidation parameters and induction time (IP) had significant association with typical indicators of volatile oxidized compounds. Hexanal and (E,E)-2,4-heptadienal were most suitable for differentiating RO sample at different storage times while 1-hexanol, 1-heptanal and (E)-2-octenal were suitable for T-RO sample. To M-RO sample, 5 substances described above together can provide a guide for monitoring lipid oxidation. M-RO has better oxidation resistance than RO, with advantage of 4 d in accelerated conditions both in sensory evaluation and PCA analysis. However, it still produces more volatile oxidized compounds and has higher peroxide value (PV) and p-anisidine value (p-AV) than T-RO sample at any sampling point. Anti-oxidation efficiency of rapeseed oil can be promoted via microwave pretreatment. This work provid new clues of benefits about microwave pretreatment in oil storage.
基金the financial support provided by the National Natural Science Foundation of China(Grant Nos.51875172 and 52105180)Zhongyuan Science and Technology Innovation Leadership Program(Grant No.214200510024)+1 种基金the Tribology Science Fund of State Key Laboratory of Tribology in Advanced Equipment(Grant No.SKLTKF21B06)Key Research and Development and Promotion Projects in Henan Province(Grant Nos.212102310410,232102230067,and 232102230081).
文摘Nickel(Ni)nanoparticles can be enriched on the surface of iron-based frictional pairs,which provides the possibility to get rid of the competitive adsorption between the polar species of vegetable oil and the surface-active nano-additives thereon.In this paper,nickel acetylacetonate was used as a precursor to in-situ synthesize nickel nanoparticles with an average diameter of about 12 nm in rapeseed oil(RO)as the reducing agent,surface modifier,and solvent as well.The tribological properties of the as-synthesized Ni nanoparticles were evaluated with a four-ball tribometer,and their tribomechanism was investigated based on the characterizations of the tribofilm on rubbed steel surfaces by the scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).It was found that the Ni nanoparticles in-situ prepared in the RO with a mass fraction of 0.3%can reduce the wear scar diameter(WSD)of the steel ball by 36%.This is because,on the one hand,the Ni nanoparticles are adsorbed on the rubbed steel surfaces to repair or fill up the micro-pits and grooves thereon.On the other hand,Ni nanoparticles participate in tribochemical reactions with atmospheric O and steel substrate to form the tribochemical reaction film on the rubbed steel surfaces with the assistance of friction-induced heat and applied normal load.In addition,an amorphous carbon film is formed on the rubbed surface via the carbonization of base oil under the catalysis of Ni nanoparticles.The adsorbed Ni layer,the tribochemical reaction film,and the carbon layer comprise a composite tribofilm composed of amorphous carbon,polar fatty acid,metallic nickel,iron oxides,and nickel oxides on the rubbed steel surfaces,which contributes to significantly improving the antiwear ability and load-carrying capacity of the RO for the steel-steel sliding pair.