Oil Vapor Research Articles

Black Cumin Essential Oil Vapor Delays Postharvest Chlorophyll Loss in Garden Cress (Lepidium sativum L.)

Purpose: In this study, the effect of different concentrations of black cumin oil vapor on the quality of garden cress leaves during postharvest storage was investigated.Research Method: Three different doses of black cumin oil vapor including 11.4 ppm (CO1); 22.7 ppm (CO2) and 45.5 ppm (CO3) were used to treat garden cress leaf. The samples only water vapor-treated were taken as control (C). After the treatments, the samples were stored in a cold room set at 2±1°C temperature and 85-90% RH for 15 days. Color values, chlorophyll content, chlorophyll SPAD, electrolyte leakage, and weight loss were determined at three days intervals during storage.Findings: The results of the study have shown that the black cumin oil vapor treatment maintained the green color and increased chlorophyll content of the garden cress leaves. According to these results, it was also found that 22.7 ppm and 45.5 ppm concentrations were more effective than an 11.4 ppm dose.Originality/Value: According to the results, the black cumin oil treatments, especially high doses, have been successful in preventing chlorophyll losses. It is concluded that spraying the black cumin vapor to garden cress before marketing will extend the storage life of garden cress leaves.

Photo-triggered on-demand carvacrol vapor release from nano-generators for non-contact bacterial inactivation between nanomaterials and bacteria

Foodborne illness outbreaks have significantly impacted public health. The contact antibacterial nanomaterials may have potential migration of nanomaterials and thus bring safety concerns. In this work, we develop photo-triggered nano-generators for on-demand release of antibacterial essential oil vapor to achieve a non-contact antibacterial strategy between nanomaterials and target bacteria. This photo-triggered nano-generator (Fe3O4@[email protected]/carvacrol, FPZC) is composed of photothermal Fe3O4@PDA-COOH cores in a zeolitic imidazolate framework-67 (ZIF-67) shell with loaded antibacterial carvacrol. Briefly, these nano-generators have magnetic transfer and immobilization, photo-thermal conversion, and controlled carvacrol vapor release capacities. Under laser irradiation at wavelength of 808 nm for 60 s, 80 mg FPZC can rapidly release carvacrol vapor to 171.0 μg/L in the air to completely inactivate Staphylococcus aureus and Escherichia coli at initial amount of 5 log CFU. Photo-triggered nano-generators exhibit flexible carvacrol release property, high photo-triggered killing rate (100%), and good recyclability (5 cycles). Compared to conventional contact antibacterial strategy, nano-generators cannot bring safety concerns with potential nanomaterial migration into sterilized material, and therefore provides promise in practical applications especially in food-related sterilization.

Combined effects of tangerine oil vapour mixed with banana flavour to enhance the quality and flavour of 'Hom Thong' bananas and evaluating consumer acceptance and responses using electroencephalography (EEG).

The objectives of this study were to investigate the effect of tangerine oil (TO) at 25, 50 and 75µL mixed with banana flavour (BF) at 25, 50 and 75µL to protect the quality and enhance the flavour of bananas. Then, 25µL TO + BF 50µL were selected for studying the quality of bananas stored at 13°C ± 2°C for 7days, and was used to test consumer brain responses using an electroencephalography (EEG). Results showed that mould grew and decomposition occurred in 10 and 50% of the 25µL TO + 50µL BF mixture and control, respectively, after 7days. Furthermore, this ratio increased ripening by having higher L*, b*, firmness and total soluble solid than the control (p < 0.05), whereas titratable acidity and pH were maintained (p > 0.05). The EEG demonstrated that consumption of TO-treated banana could increase brain alertness using stimulating the beta wave activity on banana stimulations for human brain. Limonene, one of the main components of TO, was found in the flesh of treated banana after storage for 4weeks and possibly interacted with other components to improve antifungal activity and brain response.

Features and Structure of Diaphragm Type Vacuum Pump

The diaphragm type vacuum pump is a vacuum pump that exhausts gas using the reciprocating motion of the diaphragm. Especially, it is not contaminated by oil vapor. This pump is ideal for applications that require a clean atmosphere. With the recent rapid development of the semiconductor manufacturing industry and the electronics equipment industry, demand for the diaphragm type vacuum pump has also been increasing.

Power Generation Using SOFC and VOC treatment

VOC (Volatile Organic Compounds) are organic compounds that can easily evaporate at room temperatures. Many VOCs are hazardous to human health and environment. The primary operation of an oil shuttle tanker is the loading and unloading of oil cargo at ports. During this process, a large quantity of lighter components evaporates from the oil. These oil vapours are technically called Volatile Organic Compounds (VOC), which are explosive in nature. VOC is also generated when the oil inside the tanks splashes while the ship is at sea. Here we propose the idea where rather than using these VOCs directly, we concentrate the VOC and steam reforms them which produce carbon monoxide, carbon dioxide and hydrogen. These products are then fed into Solid Oxide Fuel Cells (SOFCs) which uses these products to produce electrical energy for the ships. These SOFCs produce electrical energy with zero emissions and produce water and heat as by product which cause zero harm to the environment and reduce the pollution in the environment that the VOC would have caused. The power generated by Solid Oxide Fuel Cells is used for the electrical requirements on the ship which otherwise would have led to emissions which would have harmed the environment. The energy from the SOFC is produced with zero harmful emissions and caters to the requirements of the vessel.

Photothermal Fabrics for Efficient Oil-Spill Remediation via Solar-Driven Evaporation Combined with Adsorption.

Oil spill rapidly destroys aquatic system and threatens humans, requiring fast and efficient remedy for removal of oil. The conventional remedy employs water-floating oil adsorbents whose volume should be large enough to accommodate all oil ingredients. Here, we suggest a new concept for efficient oil-spill remediation, which combines solar-driven evaporation of light oil components and simultaneous adsorption of heavy oil components, namely, solar-driven evaporation of oil combined with adsorption (SEOA). To design photothermal oil absorbents for the efficient SEOA, we designed carbonaceous fabrics with high photothermal heating performance and oil-adsorption capacity by carbonizing nonwoven cotton fabrics. For three model organic solvents of octane, decane, and dodecane floating on water, the fabrics, respectively, accelerated the evaporation in factors of 2.0, 4.4, and 2.3 through photothermal heating under simulated sunlight condition. For the 1.18 mm thick crude oil floating on water, 70 and 77 wt % of crude oil were evaporated within 2 and 16 h, respectively, with the photothermal fabrics, whereas only 22 and 34 wt % was evaporated in the absence of the fabrics, indicating the dramatic enhancement of oil removal by solar-driven evaporation. The remaining heavy oil components were accommodated in the pores of the fabrics, removal of which showed an additional 18 wt % reduction; that is, a total 95 wt % of the crude oil was removed. The oil-treatment capacity is as high as 110 g g-1, which has never been achieved with conventional oil adsorbents to the best of our knowledge. We believe that our combinatorial SEOA approach potentially contributes to minimizing the environmental disaster through a fast and efficient oil-spill remediation.

Experimental study on flame propagation through stratified crude oil vapor in a horizontal duct

Stratified vapor–air mixtures are formed owing to evaporation after crude oil leaks in confined spaces. The concentration distribution, ignitability of the stratified vapor, flame propagation in it, and pressure buildup owing to combustion must be investigated to obtain knowledge for explosion protection and mitigation. In this study, the concentration distribution of the vapor above a 1.0-mm-thick crude oil layer in a horizontal duct was measured, and the effects of the ignition delay (tig) on the ignitability, flame behavior, and combustion overpressure were investigated. The experimental results revealed that the average concentration gradient of vapor decreased with the evaporation of the crude oil layer. The stratified vapor could be ignited from 10 to 50 min, after fuel supply, by an electric spark 150 mm above the oil surface. A two-zone flame structure including a blue premixed flame and yellow diffusion flame was observed, and the flame was farther from the oil surface as tig increased. The maximum horizontal speed of the blue flame tip and overpressure owing to combustion initially increased and then decreased as tig increased from 10 to 50 min. The yellow diffusion flame had an important function in the maximum explosion overpressure. A maximum overpressure of 530 kPa was measured at tig = 25 min, which was 80 kPa higher than that of stratified gasoline vapor obtained under nearly identical conditions in previous research.

Highly Efficient Deacidification Process for Camelina sativa Crude Oil by Molecular Distillation

Recovery and reuse of high-acidity vegetable oil waste (higher content of free fatty acids) is a major concern for reducing their effect on the environment. Moreover, the conventional deacidification processes are known to show drawbacks, such as oil losses or higher costs of wastewater treatment, for which it requires great attention, especially at the industrial scale. This work presents the design of a highly efficient and sustainable process for Camelina sativa oil deacidification by using an ecofriendly method, namely molecular distillation. Experimental studies were performed to identify operating conditions for removing of free fatty acids (FFA) by molecular distillation which involves the oil evaporation in high vacuum conditions. The experimental studies were supported by statistical analysis and technical-economic analysis. Response surface methodology (RSM) was employed to formulate and validate second-order models to predict deacidification efficiency, FFA concentration, and triacylglyceride (TAG) concentration in deodorized oil based on three parameters effects, validated by statistical p-value &lt; 0.05. For a desirability function value of 0.9826, the optimal parameters of evaporator temperature at 173.5 °C, wiper speed at 350 rpm, and feed flowrate at 2 mL/min were selected. The results for process design at optimal conditions (using conventional and molecular distillation methods) showed an efficiency over 92%, a significant reduction in FFA (up to 1%), and an increase in TAG (up to 93%) in refined oil for both methods. From an economical point of view, the deacidification by molecular distillation of Camelina sativa oil is a sustainable process: no wastewater generation, no solvents and water consumption, and lower production costs, obtaining a valuable by-product (FFA).

Surging Phenomenon in Gas Engine Crankcase

An internal combustion engine is an engine whose combustion process is inside a closed room or often referred to as the combustion chamber. The Wartsila W20V34SG engine is one of the internal combustion engines used to turn generators to generate electricity, over time some new problems arise that cause engine trip. One cause of a sudden increase in crankcase pressure is the occurrence of the phenomenon of surging in the crankcase. The causes of surging originating from the phenomenon of bursts of engine exhaust gas leaks to the surface of the oil mist pipe. Where the average temperature of the exhaust gas is approximately 530 °C so that the hot gas burst increases the temperature of the oil mist pipe and result in lower gas density and oil vapor. This phenomenon causes the air to become lighter and rise to the top and make the room in the crankcase more vacuum up to -6.29 mBar at which point the pressure will rise significantly up to ± 25 mBar. This value has exceeded the limit of the crankcase pressure protection setting which is 5.57 mBar causing the engine to trip.

Investigation Method for Carpet Fires by Analyzing Carbonation Patterns and Oil Vapor

We present a fire investigation method for carpets by analyzing the carbide pattern and oil vapor. The combustion of carpets is dominated by laminar and turbulent flow, and the combustion pattern on the floor surface is shaped like a halo pattern. The combustion pattern on flooring material sprayed with an flammable liquid takes a donut-shaped and a circular pattern in which the core is burned. Surface analysis by substance microscopy showed that the boundary surface was melting and recombining, regardless of whether or not the carpet was treated with flame retardant. In the analysis of the capture of oil vapor using a gas detector tube after combustion was completed, the general carpet was discolored to dark green with one to two divisions, and combustion of ordinary carpets and gasoline exhibited two to three divisions. It was found that one to two divisions of flameproof carpets were discolored to dark green, and combustion of flameproof carpets and gasoline produces five to six divisions. The differences in combustion products could not be clearly distinguished using gas chromatography and mass spectrometry (GC &amp; MS), but the strengths of their response patterns were found to be different.

The Application of Essential Oil Vapors at the End of Vacuum Cooling of Fresh Culinary Herbs Promotes Aromatic Recovery.

Aroma is an important quality parameter of fresh culinary herbs that may be highly affected after postharvest treatments. The innovative technology of vapor essential oil (EO) application under vacuum conditions may recover aroma lost during the postharvest processing of plant products like aromatic herbs. Hence, this study assessed the aroma recovery effect of vapor EOs applied during vacuum cooling on curly parsley and dill. The volatile organic compounds (VOCs) profiles of these aromatic herbs were studied by static headspace solid-phase microextraction (SPME), and the VOCs sorption kinetics onto the SPME stir-bar coating were modeled by the Baranyi model. At the pilot plant scale, the total VOCs contents of parsley and dill (whose extractability was increased by 10–20% after a single vacuum process) were enhanced by 4.5- and 2-fold, respectively, when vapor EOs were applied. In particular, 1,3,8-p-menthatriene and carvone (parsley) increased by 18.7- and 7.3-fold, respectively, while dill ether (the characteristic VOC of dill) augmented by 2.4-fold after vapor EOs were applied under vacuum conditions. The aroma recovery of culinary herbs was successfully validated at an industrial level in an installation developed by our group to apply vapor EOs within a vacuum cooling system, reaching total VOC recoveries of 4.9- and 2.3-fold in parsley and dill, respectively.

The character of residential cooktop fires

A series of experiments was conducted to investigate the global preignition and combustion characteristics of corn oil heated in 9.7 to 26 cm diameter pans by a residential electric-coil element cooktop. For comparison, torch-ignited gasoline, heptane, and corn oil experiments were conducted in the same configuration except without the heating element energized. Heating oil on a typical electric cooktop leads to vaporization and generation of an aerosol cloud followed by autoignition. The evolution of the light-extinction coefficient before autoignition is measured and shown to be related to the pan diameter and initial fuel mass. Continued heating leads to enhanced vaporization of the burning oil and growing fires with the peak heat release rate, radiative heat flux, radiative fraction, and peak flame height larger than the gasoline fires regardless of pan diameter. CO and soot yields, and the CO/CO2 ratio are measured to decrease with pan diameter.

Soil evaporation and its impact on salt accumulation in different landscapes under freeze–thaw conditions in an arid seasonal frozen region

AbstractSoil evaporation and its associated processes are vital for agricultural production and ecosystems in seasonal frozen regions. However, soil evaporation and its impact on salt accumulation in different landscapes during freeze–thaw periods have not been well elucidated. In this study, field experiments were carried out to investigate soil evaporation and salt accumulation patterns in three typical landscapes—namely, cropland, woodland, and natural land—in an arid seasonal frozen region located in the upper reaches of the Yellow River basin from November 2018 to April 2019. The results indicated the highest soil evaporation occurred on natural land with a total amount of 148.5 mm during the freeze–thaw period from 2018 to 2019, whereas woodland had the smallest soil evaporation of 56.9 mm. Over 75% of soil evaporation occurred during the thawing stage for all three landscapes. The average daily evaporation was below 1 mm d–1 for the whole freeze–thaw period and was 0.1 mm d–1 for the stable freezing stage. Compared with humidity and wind speed, temperature and soil water content had a greater impact on soil evaporation. At the end of the thawing stage, the salt content in the topsoil (0–10 cm) layer increased significantly with an increasing rate of 70–225%. Salt concentrations in the topsoil were significantly and linearly related to the cumulative soil evaporation during the freeze–thaw period. The current research is expected to provide implications for water management and salinity control in the upper reaches of the Yellow River basin and in other arid regions with similar conditions.

Backstreaming of pump oil vapors in vacuum systems

SummaryBackstreaming, or back‐migration, of vacuum pump oils can prevent a vacuum system from reaching its lowest possible pressure and may contaminate vacuum‐enable processes, such as thin film deposition. There are several circumstances which may lead to backstreaming, methods to measure the rate of oils reaching a vacuum chamber, and techniques to reduce or eliminate the problem. This article serves as an introduction to these issues and provides support on causes, measurement and mitigation.

Two-dimensional spreading properties and sealing characteristics of fluorocarbon surfactants on several typical hydrocarbon fuels

A new method for studying the two-dimensional spreading properties and sealing characteristics of surfactant solution on oil surface was provided. The actual spreading situation of the C4-Br/oil systems in axisymmetric geometry was observed directly using HD camera for the first time and the results showed that the aqueous film expanded outwards in a circle with the guiding device as the center. Meanwhile, the relation between spreading radius and time was investigated and evaluated using the model for surface-tension-viscous regime. The root-mean-square deviation (RMSD) values obtained from the correlation for all of the systems we studied below 1.64, indicating a good agreement between the experimental and theoretical values. The results of sealing experiments showed that the aqueous film could absolutely seal the oil surface for 27–65 s and the sealing effect would be lost after 216–742 s for different systems. The stronger the volatility was, the shorter the sealing time was. Additionally, the volume percentage of oil vapor with film was always lower than that without film even when the evaporation was saturated. These findings were of great significance to guide the preparation of efficient AFFF.

Идентификация релаксационных максимумов внутреннего трения в сплаве Zr – Nb после азотирования, окисления на воздухе и науглероживания in situ

The internal friction method was used to study the behavior of the Zr – 1 wt. % Nb alloy after oxidation in air, nitriding in an atmosphere of technical nitrogen, and in situ carburization during measurements. In this case, carbon was deposited on the samples during measurements due to thermal decomposition of vapors of diffusion oil. The pressure in the system was about 10–2 Pa. The temperature dependence of the logarithmic decrement of damped bending vibrations with a frequency of 2.2 – 2.4 Hz was measured on specimens in the form of a rectangular plate 22 × 8 × 0.3 mm in size. The measurements were carried out at a constant heating rate of about 4 K/min from room temperature to 700 – 750 °C. The obtained temperature dependences of internal friction were divided into partial maxima using a special program. The program determines the temperatures of the relaxation maxima and calculates the effective activation energy using the Werth — Marx formula. The internal friction spectra in successive measurements on one sample changed due to the diffusion redistribution of the alloy components. The parameters of the relaxation maxima for carbon (153 – 159 kJ/mol), oxygen (203 – 207 kJ/mol) and nitrogen (235 – 238 kJ/mol) in the alloy under study, depending on the experimental conditions, have been established. Grain-boundary (Gb) impurity maxima due to these impurities were also found. The following activation energies were obtained: 173 – 179 kJ/mol for C-Gb, 216 – 219 kJ/mol for O-Gb and 222 – 229 kJ/mol for N-Gb. Impurity grain-boundary maxima associated with carbon, oxygen, and nitrogen were observed in each series of measurements. The activation energy of the grain-boundary maxima proper decreases monotonically from 202.4 to 194.5 kJ/mol in a series with oxidation in air (experiments 711 – 715), and remains about 200 kJ/mol in nitrided samples.

In-vitro Antibacterial and Antibiofilm Activity of Cinnamomum verum Leaf Oil against Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumoniae.

Phytomedicines are becoming more popular in treatment of infectious diseases worldwide. Cinnamomum verum essential oil (EO) has been used as a therapeutic alternative for various diseases. This study aimed to evaluate the antibacterial and antibiofilm activity of the C. verum leaf EO against Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumoniae. Effect of EO vapor on planktonic cells was determined using microatmosphere technique. CLSI M7-A10 method was employed in Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) experiments. Effect of EO on established biofilms was quantified and visualized using XTT and Scanning Electron Microscope (SEM). In-vitro toxicity was evaluated using Human Keratinocytes (HaCaT). Chemical analysis of EO was done using Gas Chromatography- Mass Spectrometry (GC-MS). All tested strains were sensitive to cinnamon oil vapor. EO exhibited 0.5 and 1.0 mg/mL MIC and MBC against all test strains. Minimum Biofilm Inhibitory and Biofilm Eradication Concentrations (MBIC50 and MBEC) were 1.0 and 4.0 mg/mL. SEM indicated cellular shrinkages, cell wall damages, and decreased biofilm densities. Cinnamon oil didn't show any toxicity on HaCaT cell at any concentration tested. Eugenol was the most abundant compound in C. verum oil. C. verum EO shows an antibacterial and antibiofilm activity with minimal toxicity on host.

Influence of Engine Oil Evaporation Characteristics on Oil Consumption of Internal Combustion Engines.

Influence of Engine Oil Evaporation Characteristics on Oil Consumption of Internal Combustion Engines.

Organic pigment particle-stabilized Pickering emulsions

Pickering emulsions sometimes dry to obtain macro-porous or sheet-like structural materials. However, the process through which these materials form is unknown. This work uncovers the processes through which sheet-like structural materials form in an evaporating water-in-oil Pickering emulsion. Small samples of water-in-heptane Pickering emulsions, stabilized by colored organic pigment particles, were diluted with n-heptane and allowed to evaporate quiescently on a hydrophilic glass slide under an optical microscope. The colored nature of the particles enabled direct visualization of the behavior of the particle-coated water droplets as evaporation of oil progresses without the need for added dye. Optical microscopy revealed that a sheet-like material is formed from complete coalescence of particle-coated water droplets which locks the enwrapping particle layers. Initially, the water droplets become flattened and then change from spherical to a polyhedral shape, coalescing in areas defunct of particles and locking the particle layers into a sheet-like material.

PROMOTION OF ORGANIC AND SUSTAINABLE AGRICULTURE THROUGH THE USE OF BIO-FERTILIZERS

Tamarind (Tamarindus indica) belongs to the family Leguminosae. It is commonly growing in tropical and subtropical regions now and is one of the most important plant resources as cuisine materials. Antioxidative activity of tamarind seeds was investigated. An ethanol extract prepared from the seed coat contained antioxidative activity as measured by the thiocyanate and thiobarbituric acid (TBA) method. Essential oils are highly odorous droplets found in minimal quantities in the flowers, stems, leaves, roots and barks of aromatic plants. They are not recognized as true oils as the vegetable oils, but highly fluid and volatile. Experts recognize an essential oil by its aroma and test the oil characteristics such as vaporization and crystallization point using Differential Scanning Calorimetry (DSC). DSC has emerged as a powerful experimental technique for determining thermodynamic properties of biomacromolecules. Volatile components of tamarind leaves and seed locally grown will be isolated by Microwave Assisted Extraction (MAE). The presence of essential oil as the volatile components will be investigated to determine whether this method is effective or not to extract the oil from tamarind leaves and seed. The parameters that will be measured are the time for the oil droplets formation and the optimum temperature for the extraction of oil. At the end of the extraction, amber color oil was obtained. Results showed that the time for the oil droplets formation increasing with the increasing weight of sample for both tamarind leaves and seed samples. The optimum temperature for the extraction obtained was 125ºC with the yield of 1.2 mL of seed oil. The vaporization and crystallization point of oil are presented in the DSC curve and the specific heat capacity of the oil are calculated.