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1
Daryasafar, Amin, Arash Ahadi, and Riyaz Kharrat. "Modeling of Steam Distillation Mechanism during Steam Injection Process Using Artificial Intelligence." Scientific World Journal 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/246589.
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Steam distillation as one of the important mechanisms has a great role in oil recovery in thermal methods and so it is important to simulate this process experimentally and theoretically. In this work, the simulation of steam distillation is performed on sixteen sets of crude oil data found in the literature. Artificial intelligence (AI) tools such as artificial neural network (ANN) and also adaptive neurofuzzy interference system (ANFIS) are used in this study as effective methods to simulate the distillate recoveries of these sets of data. Thirteen sets of data were used to train the models and three sets were used to test the models. The developed models are highly compatible with respect to input oil properties and can predict the distillate yield with minimum entry. For showing the performance of the proposed models, simulation of steam distillation is also done using modified Peng-Robinson equation of state. Comparison between the calculated distillates by ANFIS and neural network models and also equation of state-based method indicates that the errors of the ANFIS model for training data and test data sets are lower than those of other methods.
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Milojevic, Svetomir, Dragana Radosavljevic, Vladimir Pavicevic, Srdjan Pejanovic, and Vlada Veljkovic. "Modeling the kinetics of essential oil hydrodistillation from plant materials." Chemical Industry 67, no. 5 (2013): 843–59. http://dx.doi.org/10.2298/hemind121026009m.
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The present work deals with modeling the kinetics of essential oils extraction from plant materials by water and steam distillation. The experimental data were obtained by studying the hydrodistillation kinetics of essential oil from juniper berries. The literature data on the kinetics of essential oils hydrodistillation from different plant materials were also included into the modeling. A physical model based on simultaneous washing and diffusion of essential oil from plant materials were developed to describe the kinetics of essential oils hydrodistillation, and two other simpler models were derived from this physical model assuming either instantaneous washing followed by diffusion or diffusion with no washing (i.e. the first-order kinetics). The main goal was to compare these models and suggest the optimum ones for water and steam distillation and for different plant materials. All three models described well the experimental kinetic data on water distillation irrespective of the type of distillation equipment and its scale, the type of plant materials and the operational conditions. The most applicable one is the model involving simultaneous washing and diffusion of the essential oil. However, this model was generally inapplicable for steam distillation of essential oils, except for juniper berries. For this hydrodistillation technique, the pseudo first-order model was shown to be the best one. In a few cases, a variation of the essential oil yield with time was observed to be sigmoidal and was modeled by the Boltzmann sigmoid function.
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Richardson, W. C., M. K. Beladi, and C. H. Wu. "Steam Distillation Studies for the Kern River Field." SPE Reservoir Evaluation & Engineering 3, no. 01 (February 1, 2000): 13–22. http://dx.doi.org/10.2118/60909-pa.
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Summary The interactions of heavy oil and injected steam in the mature steamflood at the Kern River Field have been extensively studied to gain insight into the effect of steam on compositional changes of oil during the recovery process and to provide input for compositional thermal simulation. Steam distillation behavior of this 13°API California oil between 300 and 467°F under a variety of process conditions, along with extensive analysis of distilled hydrocarbons were incorporated to give a more in-depth description of what is happening to the oil and what changes are occurring in the distillates or produced oil. This information was further integrated with analysis of the field distillate, "casing blow," to infer what is happening in the field. The results show that steam distillation is temperature dependent and more important than originally thought. The data developed in this study are a basis for improvement of numerical thermal models with potential for better designed steamfloods and reservoir management. The results may also impact certain logging techniques used in steamfloods and possible heavy oil upgrading techniques. Kern River oil is more than 10% distillable at 300°F and 15% distillable at 400°F in dynamic laboratory steam distillation tests at steam throughputs of four times the initial volume of oil. Distillate physical properties of density, viscosity, molecular weight, and hydrocarbon composition of the distillates changed significantly. Distillate properties increased in value with increasing steam throughput, and at higher temperatures. This information is important in the tuning of equations of state, including hydrocarbon-water interaction parameters for compositional thermal simulation. Analysis of the field distillate, "casing blow," showed properties similar to laboratory distillates at low steam throughputs. The observation of a light field distillate production in a mature steamflood compared to laboratory measurements implies that the casing system temperature is a major controlling factor in "casing blow" composition and quantity. Background The phase equilibrium behavior of reservoir fluids is an important phenomenon in petroleum production, particularly in enhanced oil recovery processes. However, phase behavior for heavy oils (<15°API) under steamflood has generally been felt to be unimportant or a minimal effect to be neglected.1 A major question exists about whether the phases and fluids in a steamflood are in equilibrium or not. Proper modeling of a reservoir production process would be expected to include knowledge of the phases and their equilibrium compositions. In heavy oil, devoid of significant C1 to C6 composition, it has been sufficient to treat the oil as a dead oil or a nonvolatile phase for steamflood modeling purposes. A history match numerical study2 of steamflood performance in the Kern River Field treated the oil as nonvolatile, and was conducted without the inclusion of hydrocarbon compositional effects. Through the classic works of Willman et al.,3 Volek and Pryor,4 and Closmann and Seba,5 steam distillation has been shown to be an important component mechanism in the overall steamflooding process.6–10 The practical limit of how much of a reservoir fluid can be distilled, is obtained in dynamic steam distillation experiments developed by Brown and Wu,11,12 extended by Hseuh, Hong, and Duerksen,13,14 and refined by Wu and co-workers.15,16 This body of work demonstrates that steam distillation is an operative mechanism in laboratory models, but it has been difficult to translate this to a quantitative contribution to the field recovery process of steamflooding. Laboratory steam distillation experiments have generally been conducted as dynamic tests, that may or may not be near equilibrium. Experiments near equilibrium with extensive analysis of the phases will yield values for the vapor-liquid equilibrium (VLE) ratios (K values), another way of assessing the importance of compositional changes in steamflooding. A major recent steam distillation study by Northrup and Venkatesan17 has been completed on the South Belridge oil. Compositional data from simple distillation and laboratory steamfloods of oils in the range 13 to 33°API, including Kern River oil, has recently been reported.18 The current report is an extension of that work to include analyses of produced field samples for the Kern River steamflood. Compositional reservoir simulators demand greater emphasis on obtaining more crude oil compositional data, which would be used as input into an equation of state (EOS) or to calculate equilibrium ratios, K values. An appreciable amount of incremental oil19,20 could be recovered by steamflooding due to steam distillation depending on the composition of the crude oil. The present work establishes laboratory data to facilitate such efforts. The EOS approach and table look-up for two-phase K values are applied in thermal numerical simulation models, even though they do not fully represent three-phase separation (steam distillation). A three-component system approximation was used by Coats and Smart21 to incorporate steam distillation effects by adding water as a component in the vapor phase. The compositional variations due to steam distillation cannot be fully described by Coats' model. A difficulty in this model is the lack of three-phase laboratory steam distillation data for high-temperature and high-pressure conditions. A future goal of this research is to obtain three-phase laboratory steam distillation data to better understand the effects of water and its vapor on the hydrocarbon separation processes at high-temperature and high-pressure conditions. This includes the investigation on both the pure hydrocarbon component/water systems and crude oil/water systems. The three-phase equilibrium ratios or K values determined from these laboratory investigations are necessary to accurately describe the effects of steam distillation in mathematical reservoir simulation. Experiment Steam Distillation Cell and Procedures. In order to describe the existing laboratory procedures, Fig. 1 is presented. This experimental setup is used to perform three different types of tests:Static system pressure test (SPT).Dynamic distillation test (DDT).Stagewise isochoric distillation test (SWID). The experimental apparatus is composed of the injection assembly (Ruska pumps and the gas bottles), the distillation cell assembly, the withdrawal assembly (condenser, separator) and the automation/data acquisition assembly. The steam distillation apparatus has been extensively described elsewhere.22
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Zlatev, Zlatin, and Galya Shivacheva. "YIELD ANALYSIS OF ESSENTIAL OILS EXTRACTED BY STEAM DISTILLATION." Applied Researches in Technics, Technologies and Education 6, no. 4 (2018): 300–305. http://dx.doi.org/10.15547/artte.2018.04.003.
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A comparative analysis of models describing the change in yield of essential oil over time is presented in the article. Nonlinear models, third-order polynomial and second exponential model describe with sufficient precision the change of experimental data over time. These models can be used to predict the extraction time of essential oils. The results can be useful in planning and managing the production of essential oils. For this purpose, further research is needed to determine the diffusion coefficient and to analyze the impact of the individual elements of the process on the production of essential oils.
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Northrop, Paul S., and Venkat N. Venkatesan. "Analytical steam distillation model for thermal enhanced oil recovery processes." Industrial & Engineering Chemistry Research 32, no. 9 (September 1993): 2039–46. http://dx.doi.org/10.1021/ie00021a027.
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Binh Thanh, Nguyen Dang. "KINETICS AND MODELING OF OIL EXTRACTION FROM VIETNAM LEMONGRASS BY STEAM DISTILLATION." Vietnam Journal of Science and Technology 55, no. 5A (March 24, 2018): 58. http://dx.doi.org/10.15625/2525-2518/55/5a/12179.
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Essential oils from parts of plants such as stump, flower, kernel, and seed are usually produced by extraction, distillation and mechanical press. In practice, steam distillation is commonly used for the extraction of crude essential oils since it is not only a simple process but also applicable at various scales. Furthermore, the method makes it possible for a keeping of precious components of the oils unchanged. Therefore, studies on kinetics and modeling of the essential oil steam distillation are needed for the optimization of the operating conditions, energy requirement, and the process scale-up.In this work, experiments of lemongrass (Cymbopogon Citratus) steam distillation were carried out and a kinetics model was developed for the extraction of lemongrass essential oil. Raw materials were pretreated by natural drying, primarily crushing and chopping prior to the distillation. The oil yield obtained is in the range of 2.1 – 2.9 ml/kg of raw materials. Composition of the crude oil extracted was measured by GC-MS. Measurements showing that the oil product contains 70.5 % of precious component–Citral in which Neral is 29.8 % and Geranial 40.7 %. The kinetics parameters were estimated from experimental data conducted at various operating conditions for different preparation of the raw materials. The process rate constant (extraction rate constant) describing the extraction efficiency obtained from this study is varied from 0.02 to 0.027 min-1 using first-order kinetic model.
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Maharaj, Sharad, and David McGaw. "Mathematical Model for the Removal of Essential Oil Constituents during Steam Distillation Extraction." Processes 8, no. 4 (March 29, 2020): 400. http://dx.doi.org/10.3390/pr8040400.
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Steam distillation is the conventional means by which oils are extracted in the flavour and fragrance industry. A mathematical model for the steam distillation extraction (SDE) of air-dried Ocimum basilicum (basil) leaves has been developed and tested using a small-scale pilot plant. The model predicts the removal of oil components from the plant matrix and subsequent transfer to the steam. It also accounts for the diffusional transfer of components within the leaf and the simultaneous convective transfer into the vapour phase while also respecting the individual components’ volatilities. It has been applied vertically on an element-by-element basis through the bed for a mixture of major and minor components. The proposed SDE model appears to be a good match between predicted values and the experimental data. The model predicts a faster initial extraction rate for components such as α-pinene and α-terpinene, possibly due to preferential extraction of light, volatile components present in larger quantities.
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Li, Hongshen, and Shizhong Li. "Optimization of Continuous Solid-State Distillation Process for Cost-Effective Bioethanol Production." Energies 13, no. 4 (February 15, 2020): 854. http://dx.doi.org/10.3390/en13040854.
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To improve the efficiency of bioethanol production, an advanced process was required to extract ethanol from solid-state fermented feedstock. With regard to the characteristics of no fluidity of solid biomass, a continuous solid-state distillation (CSSD) column was designed with a proprietary rotary baffle structure and discharging system. To optimize the operation condition, fermented sweet sorghum bagasse was prepared as feedstock for a batch distillation experiment. The whole distillation time was divided into heating and extracting period which was influenced by loading height and steam flow rate simultaneously. A total of 16 experiments at four loading height and four steam flow rate levels were conducted, respectively. Referring to packing, rectifying column, mass, and heat transfer models of the solid-state distillation heating process were established on the basis of analyzing the size distribution of sweet sorghum bagasse. The specific heat capacity and thermal conductivity value of fermented sweet sorghum bagasse were tested and served to calculate the ethanol yielding point and concentration distribution in the packing. The extracting process is described as the ethanol desorption from porous media absorbent and the pseudo-first-order desorption dynamic model was verified by an experiment. Benefit (profit/time) was applied as objective function and solved by successive quadratic programming. The optimal solution of 398 mm loading height and 8.47 m3/h steam flow rate were obtained to guide a 4 m in diameter column design. One heating and two extracting trays with 400 mm effective height were stacked up in an industrial CSSD column. The steam mass flow rate of 0.5 t/h was determined in each tray and further optimized to half the amount on the third tray based on desorption equation.
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Dung, Nguyen Trung. "EXPERIMENTAL AND MODELING STUDIES OF VIETNAM LEMONGRASS ESSENTIAL OIL EXTRACTION PROCESS USING RESPONSE SURFACE METHODOLOGY." Vietnam Journal of Science and Technology 56, no. 2A (June 21, 2018): 11–16. http://dx.doi.org/10.15625/2525-2518/56/2a/12622.
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Natural precious products such as aroma compounds, essential oils, and bio-activated materials are usually extracted from about 30,000 botanical species. These extracts are often high competitive market due to their small content (less than 1 %) in plants and high purification cost. Thus, development of a modeling for the optimization of the crude oil extraction is highly paid attention. In this work, a modeling of Vietnam lemongrass oil extraction using steam distillation is developed and the optimization of the process parameters is performed using response surface methodology (RSM). The operating parameters considered for the modeling and optimization are specific area of raw materials, moisture content of feedstock, and steam rate. Experimental data show that the oil yield from steam distillation of Vietnam lemongrass is significantly affected by the three mentioned factors. Box-Behnken design (BBD) and analysis of variance (ANOVA) are used to examine the effects of operating parameters on the extraction efficiency. On the basis of the measurements and RSM, a quadric regression model as a function of steam rate, specific area and moisture content of materials is estimated. The optimized operating conditions of the lemongrass hydrodistillation are also obtained by applying the proposed modeling.
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Fawwaz Alrebei, Odi, Ali Al-Doboon, Philip Bowen, and Agustin Valera Medina. "CO2-Argon-Steam Oxy-Fuel Production for (CARSOXY) Gas Turbines." Energies 12, no. 18 (September 19, 2019): 3580. http://dx.doi.org/10.3390/en12183580.
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Due to growing concerns about carbon emissions, Carbon Capture and Storage (CCS) techniques have become an interesting alternative to overcome this problem. CO2-Argon-Steam-Oxy (CARSOXY)-fuel gas turbines are an innovative example that integrates CCS with gas turbine powergen improvement. Replacing air-fuel combustion by CARSOXY combustion has been theoretically proven to increase gas turbine efficiency. Therefore, this paper provides a novel approach to continuously supply a gas turbine with a CARSOXY blend within required molar fractions. The approach involves H2 and N2 production, therefore having the potential of also producing ammonia. Thus, the concept allows CARSOXY cycles to be used to support production of ammonia whilst increasing power efficiency. An ASPEN PLUS model has been developed to demonstrate the approach. The model involves the integrations of an air separation unit (ASU), a steam methane reformer (SMR), water gas shift (WGS) reactors, pressure swing adsorption (PSA) units and heat exchanged gas turbines (HXGT) with a CCS unit. Sensitivity analyses were conducted on the ASU-SMR-WGS-PSA-CCS-HXGT model. The results provide a baseline to calibrate the model in order to produce the required CARSOXY molar fraction. A MATLAB code has also been developed to study CO2 compression effects on the CARSOXY gas turbine compressor. Thus, this paper provides a detailed flowsheet of the WGS-PSA-CCS-HXGT model. The paper provides the conditions in which the sensitivity analyses have been conducted to determine the best operable regime for CARSOXY production with other high valuable gases (i.e., hydrogen). Under these specifications, the sensitivity analyses on the (SMR) sub-model spots the H2O mass flow rates, which provides the maximum hydrogen level, the threshold which produces significant CO2 levels. Moreover, splitting the main CH4 supply to sub-supply a SMR reactor and a furnace reactor correlates to best practices for CARSOXY. The sensitivity analysis has also been performed on the (ASU) sub-model to characterise its response with respect to the variation of air flow rate, distillation/boiling rates, product/feed stage locations and the number of stages of the distillation columns. The sensitivity analyses have featured the response of the ASU-SMR-WGS-PSA-CCS-HXGT model. In return, the model has been qualified to be calibrated to produce CARSOXY within two operability modes, with hydrogen and nitrogen or with ammonia as by-products.
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Dao, Tan Phat, Hoang Thang Do, Quang Khoi Le, Nguyen Van Gia Phap, Long Giang Bach, Nguyen Van Muoi, and Mai Huyng Cang. "Kinetic Studies on Extraction of Essential Oil from Lemongrass Leaves (Cymbopogon citratus) by Steam Distillation Industrial Scale." Asian Journal of Chemistry 32, no. 6 (2020): 1399–403. http://dx.doi.org/10.14233/ajchem.2020.22227.
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Study on kinetics and modeling of the essential oil steam distillation are required for the optimization of the energy requirement, parameters and the process scale-up. In this study, hydrodistillation for extraction of essential oils from lemongrass (Cymbopogon citratus) steam distillation was investigated. The recovery of essential oils was carried out on an industrial scale instrument and with with different material quantities. The experimental results are determined by the integral method of analysis. The kinetic parameters were evaluated from experimental data, which were generated at the different weights of the lemongrass. The extraction rate constant explaining the extraction efficiency achieved from this study is found to be k2 of 0.0661 min-1 in 710 kg using a second-order kinetic model. The GC/MS results revealed that 14 components were identified in Cymbopogon citratusoils. The oil is extremely rich in citral (69.775%), which obtained in 180 min.
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Hasinah Binti Johari, Siti Nur, Mohd Hezri Fazalul Rahiman, Najidah Hambali, Ramli Adnan, and Mazidah Tajjudin. "Design of IMC-PID controller with fractional-order filter for steam distillation essential oil extraction process." Indonesian Journal of Electrical Engineering and Computer Science 21, no. 2 (February 1, 2021): 801. http://dx.doi.org/10.11591/ijeecs.v21.i2.pp801-810.
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<p>Essential oils are one of the industry's major compounds, particularly in the pharmaceutical, perfume and food sectors. They were acquired using several methods such as steam distillation. In this method, heat from the steam will release the aromatic molecule at their specific boiling points. Thus, it is important to regulate the steam temperature at the correct level to get the perfect composition of the yield. Many studies have shown that essential oil is volatile and sensitive to excess heat. In order to maintain the desired steam temperature, this study proposed an internal model control (IMC) based PID with fractional-order filter as a controller for this system. IMC is a model-based control structure that can handle parameter variations and load disturbance very well. With the inverse model imposed in the loop, IMC can gain a perfect tracking control as well. The implementation of a fractional-order filter cascaded to the PID controller may enhance the system robustness to process gain with its iso-damping properties. This study was conducted by simulation using MATLAB R2018. The step response of the closed-loop system has been evaluated with varying filter parameters depending on the desired phase margin of the open-loop reference model. <em></em></p>
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Zekovic, Zoran, Zika Lepojevic, Svetlana Milosevic, and Aleksandar Tolic. "Modeling of the thyme: Liquid carbon dioxide extraction system." Acta Periodica Technologica, no. 34 (2003): 125–33. http://dx.doi.org/10.2298/apt0334125z.
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The extraction of thyme (Thymus vulgaris L) by liquid carbon dioxide was investigated. The obtained extracts were analyzed by HPLC and GC-MS methods, and their composition was compared with that of the essential oil obtained by steam distillation and by supercritical carbon dioxide at 100 bar and 40?C. To model extraction of the thyme - liquid carbon dioxide system, we used the Reverchon - Sesti Osseo equation, as well as our modified equation.
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de Albuquerque, André Ribeiro Lins, Cecília Sosa Arias Peixoto, Luiz Teruo Kawamoto Júnior, Georgea Duarte, Jones Erni Schmitz, and Cesar Xavier. "Software to Improve Control System in an Ethanol Distillation Process." Advanced Materials Research 827 (October 2013): 169–75. http://dx.doi.org/10.4028/www.scientific.net/amr.827.169.
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This work has developed a predictive control solution based on specific models for the process of ethanol distillation. The advantages of such control are relative to the prediction of the consequences of the disturbances by the model, thus enabling the control action to be done in a previous manner, resulting in the minimization of the variables fluctuation controlled by the process. This results in, among other advantages, energy economy, in the improvement of the ethanol produced and in the increasing production capacity. Another desirable characteristic in this control mode is its capacity to act in non-linear systems as is the case of the distillation columns. Finally, it must be noted that with the application of an advanced control solution, as proposed in this study, it becomes viable, in a second moment, for the ethanol plants to operate in multiple operational conditions, such as: 1) maximum energy economy (scarcity of raw material, for example) and: 2) maximum production condition (for situations with excess of materials to be distilled). The models developed in this project will consist of purely empirical models. Several tests will be done in the different types of models to measure the precision and robustness. The proposed control strategy demonstrated be able to control selected control loops adequately. Steam savings and reduction of product losses were observed.
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Roth, Thorsten, Lukas Uhlenbrock, and Jochen Strube. "Distinct and Quantitative Validation for Predictive Process Modelling in Steam Distillation of Caraway Fruits and Lavender Flower Following a Quality-By-Design (QbD) Approach." Processes 8, no. 5 (May 16, 2020): 594. http://dx.doi.org/10.3390/pr8050594.
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A quality by design (QbD) approach as part of process development in the regulated, pharmaceutical industry requires many experiments. Due to the large number, process development is time consuming and cost intensive. A key to modern process development to reduce the number of required experiments is a predictive simulation with a validated physico-chemical model. In order to expand the process expertise of steam distillation through maximum information, a model development workflow is used in this paper, which focuses on implementation, verification, parametrization and validation of a physico-chemical model. Process robustness and sensitivity of target values can be determined from the developed general model and design of experiments with statistical evaluations. The model validation is exemplified by two different types of plant systems, caraway fruits (Carum Carvi) and lavender flowers (Lavandula).
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Xue, Jianliang, Qinqin Cui, Jie Ming, Yu Bai, and Lin Li. "Analysis of Thermal Properties on Backward Feed Multieffect Distillation Dealing with High-Salinity Wastewater." Journal of Nanotechnology 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/518015.
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Theoretical investigations on thermal properties of multieffect distillation (MED) are presented to approach lower capital costs and more distillated products. A mathematical model, based on the energy and mass balance, is developed to (i) evaluate the influences of variations in key parameters (effect numbers, evaporation temperature in last effect, and feed salinity) on steam consumption, gained output ratio (GOR), and total heat transfer areas of MED and (ii) compare two operation modes (backward feed (BF) and forward feed (FF) systems). The result in the first part indicated that GOR and total heat transfer areas increased with the effect numbers. Also, higher effect numbers result in the fact that the evaporation temperature in last effect has slight influence on GOR, while it influences the total heat transfer areas remarkably. In addition, an increase of feed salinity promotes the total heat transfer areas but reduces GOR. The analyses in the second part indicate that GOR and total heat transfer areas of BF system are higher than those in FF system. One thing to be aware of is that the changes of steam consumption can be omitted, considering that it shows an opposite trend to GOR.
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Igbagara, Princewill. "DESIGN ADAPTATION OF BATCH CRUDE OIL BOILER FOR CONTINUOUS DISTILLATION OPERATIONS." European Journal of Physical Sciences 4, no. 1 (August 1, 2021): 49–62. http://dx.doi.org/10.47672/ejps.754.
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Purpose: Boilers are some of the most critical equipment in many production process especially in refinery operations, as it is used in generating steam for different applications. Different types of boilers are available commercially and have comparative advantages over one another. The pot or kettle boiler is the foremost of these equipment and consists of an empty vessel with a secure lid and a burner that is the source of heating. Though overtaken in industrial applications by more modern designs, these simple boilers which are often batch process equipment are still useful for small production processes at low pressures. The work here developed design adaptation of these batch boilers for continuous vaporization of crude oil for artesian refining of the oil.
Methodology: Physical and assay data of Bonnylight Crude Oil (BLCO) was used for the work from the library of ASPEN Technologies. Simple mathematical models were developed from interpretation of implicit phenomena of the boiler transformation process. The models were validated using ASPEN HYSYS process simulation software Version 10.
Findings: Computational results of the models and simulation results gave good convergence except for the heat transfer parameter of the model which had almost 100% of the simulation value. Nevertheless, the models have good predictive capabilities
Recommendation: The design adaption models herein developed can be deployed with reasonable accuracy for the heating of crude oil especially for small artesian operations. However, the study space of the subject matter can be expanded for better accuracy and reliability.
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Nguyen Dang Binh, Thanh, Dung Nguyen Trung, and Duc Hong Ta. "MODELING OF ESSENTIAL OIL EXTRACTION PROCESS: APPLICATION FOR ORANGE, POMELO, AND LEMONGRASS." Vietnam Journal of Science and Technology 56, no. 4A (October 19, 2018): 182. http://dx.doi.org/10.15625/2525-2518/56/4a/12811.
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ABSTRACT - HCTN - 44In this study, the kinetic models of steam distillation of orange (Citrus Sinensis (L.) Osbeck), pomelo (Citrus grandis L.), and lemongrass (Cymbopogon Citratus) for the recovery of essential oils were developed. The model parameters were estimated based on experimental data and comprehensive kinetic mechanisms of the solid-liquid extraction process. Numerical results showed that, the extraction mechanism of the three materials were best fit to the Patricelli two-stage model in which the diffusion of the oil was followed by the washing step. Moreover, the model parameters obtained from the measured data reflected clearly the nature of the two-stage extraction at which the kinetic rate of the washing step (surface extraction) was higher than that of in-tissue diffusion step. Thus, the kinetics of the extraction processes obtained from the present work could be used for the scale-up of the extraction process operating at a large scale and for the purpose of process control as well.
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Joshi, R. K. "In vitro antimicrobial and antioxidant activities of the essential oil of Craniotome furcata." Journal of Applied and Natural Science 2, no. 1 (June 1, 2010): 57–62. http://dx.doi.org/10.31018/jans.v2i1.95.
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The aim of present study was, to investigate the essential oil of Craniotome furcata for its antimicrobial and antioxidant activities. The essential oil was obtained by steam distillation of the flowering aerial parts of C. furcata. The oil was tested for its antimicrobial activity in vitro against four Gram-positive, four Gram-negative bacteria and three fungi, by using disk diffusion and tube dilution methods. The antioxidant potential of the essential oil was investigated by two different models DPPH free radical and ABTS free radical cation scavenging. The essential oil was effective against all the tested microorganisms, with minimum inhibitory concentrations (MICs) ranged from 4.11±1.44 to 0.30±0.10 mg/ml. The oil showed antioxidant activity in DPPH free radical and ABTS free radical cation scavenging model. The results of this study revealed that the essential oil of C. furcata possesses antimicrobial and antioxidant activities.
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Jordan, Kieran N., and Timothy M. Cogan. "Production of acetolactate byStreptococcus diacetylactisandLeuconostocspp." Journal of Dairy Research 55, no. 2 (May 1988): 227–38. http://dx.doi.org/10.1017/s0022029900026054.
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SummaryThe effect of several parameters on the decarboxylation of α-acetolactic acid (ALA) to diacetyl and acetoin was studied in model experiments. At temperatures > 50 °C, relatively more diacety1 than acetoin was produced. Regardless of temperature, HC1 increased the production of acetoin (58 mol% conversion at max.) and prevented the production of diacetyl. Steam distillation of ALA caused ~ 55 mol%/h conversion to acetoin and 7 mol%/h to diacetyl. Production of acetoin was proportional to the ALA concentration. Based on these results two methods for the quantitative measurement of ALA were developed. Only one of 17 strains ofStreptococcus diacetylactis (Lactococcus lactissubsp.lactisbiovar.diacetilactis, new nomenclature) and three of three strains ofLeuconostocspp. produced ALA. The implications of these findings are discussed.
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Efremov, Aleksandr Alekseyevich, and Irina Dement'yevna Zykova. "ANTIRADICAL ACTIVITY OF EXTRACTIVES FROM THE ACHILLEA MILLEFOLIUM L. OF THE SIBERIAN REGION." chemistry of plant raw material, no. 2 (June 10, 2021): 129–35. http://dx.doi.org/10.14258/jcprm.2021028888.
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In model reactions with a free stable 2,2-diphenyl-1-picrylhydrazyl radical, the antiradical properties of extractives of common yarrow (Achillea millefolium L.) growing in the Krasnoyarsk Territory were studied: water-alcohol extracts with an alcohol content of 20, 40 and 70% and essential oil. Whole essential oil is obtained by exhaustive hydro-steam distillation for 11 hours. In addition, separate oil fractions were obtained: the first after 20 minutes from the start of distillation, the second after the next 50 minutes, the third after the next 180 minutes, and the fourth after the next 360 minutes.
The results of the DPPH test showed that ARA is minimal for alcohol-soluble substances and increases for aqueous-alcoholic extracts from 20.3% in the case of a 20% extract to 21.8% for a 70% aqueous-alcoholic extract. ARA of the obtained samples of essential oil surpasses the ARA values of aqueous, alcoholic and aqueous-alcoholic extracts. It was found that the APA value for 1 fraction of oil is 29.7% and increases with the transition to subsequent fractions to 54.3%. Whole Yarrow essential oil has an ARA value of 52.8%.
According to the ARA value, the extractives of yarrow can be arranged in the following row: whole essential oils> 70% aqueous-alcoholic extract> 40% extract> 20% extract> aqueous extract> 96% alcoholic extract.
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Benali, Nejib, Daoud Ben, Manel Farhati, Chedly Tizaoui, and Mehrez Romdhane. "Study of essential oils adsorption on three phosphate fertilizers." Chemical Industry and Chemical Engineering Quarterly 24, no. 3 (2018): 251–66. http://dx.doi.org/10.2298/ciceq170207037b.
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In this paper, we report the study of essential oils adsorption on three phosphate fertilizers: monoammonium phosphate (MAP), diammonium phosphate (DAP) and triple superphosphate (TSP), with the aim to prepare a bifunctional product which can be used as a fertilizer and biopesticide. Essential oils were isolated by steam distillation from Eucalyptus salubris and Artemisia herbaalba and analysed by GC-MS and GC-FID. About 12 and 22 constituents were identified and quantified in these oils, respectively. The kinetic adsorption study of essential oils showed that DAP and TSP exhibited high adsorption capacities compared with MAP (DAP (0.143 g/g) and TSP (0.139 g/g) for E. salubris essential oil and (DAP (0.135 g/g) and TSP (0.134 g/g) for A. herba- -alba essential oil). The adsorption isotherms of all identified components in the E. salubris essential oil were determined and the Langmuir and Freundlich models were used to describe the experimental data. Langmuir model fitted well the isotherms of the majority of the essential oil components (1,8-cineole, ?-pinene, ?-pinene, isopinocarveol, ?-eudesmol, ?-phellandrene, pinocarvone, p-cymene and spathulenol) and only terpineol and globulol isotherm data followed the Freundlich model. The selectivity was affected by the abundance of each component in the crude essential oil and the polarity of terpenic components.
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Huang, Weihuan, Xiaobin Yu, Ning Liang, Wei Ge, Hin Fai Kwok, Clara Bik-San Lau, Yaolan Li, and Hau Yin Chung. "Anti-angiogenic Activity and Mechanism of Sesquiterpene Lactones from Centipeda minima." Natural Product Communications 11, no. 4 (April 2016): 1934578X1601100. http://dx.doi.org/10.1177/1934578x1601100402.
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Centipeda minima is a Chinese herbal medicine used in the treatment of various diseases including cancer. An ethanol extract of the herb, its four fractions with different polarities, and two volatile oils prepared by steam distillation (SD) and supercritical fluid extraction (SFE) were investigated for their anti-angiogenic activity in a wild-type zebrafish model using a quantitative endogenous alkaline phosphatase (EAP) assay. The SFE oil displayed potent anti-angiogenic activity. Fifteen sesquiterpene lactones (SLs; compounds 1–15) isolated from the SFE oil were evaluated for their anti-angiogenic effect. Results revealed that pseudoguaianolide type SLs (1–8) inhibited vessel formation in the zebrafish embryos while guaianolide type SLs (9–15) showed little effect. Among the active ones, 6- O-angeloylenolin (1), a major component of SFE oil, possessed the strongest effect by reducing vessel formation in zebrafish embryos to 40% of the control value at 29.7 μM. Further study using the Tg ( fli1a:EGFP) y1-type zebrafish model revealed that it blocked both intersegmental blood vessels (ISVs) and subintestinal vessels plexus (SIVs) formation in zebrafish embryos. Real-time polymerase chain reaction assay on the wild-type zebrafish embryos suggested that 6- O-angeloylenolin affected multiple molecular targets related to angiogenesis including VEGF receptor, angiopoietin, and its receptors. Taken together, our findings demonstrate that C. minima possesses anti-angiogenic activity, and 6- O-angeloylenolin is a promising candidate for the development of an anti-angiogenic agent.
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SANTORO, G. F., M. G. CARDOSO, L. G. L. GUIMARÃES, J. M. FREIRE, and M. J. SOARES. "Anti-proliferative effect of the essential oil ofCymbopogon citratus(DC) Stapf (lemongrass) on intracellular amastigotes, bloodstream trypomastigotes and culture epimastigotes ofTrypanosoma cruzi(Protozoa: Kinetoplastida)." Parasitology 134, no. 11 (August 9, 2007): 1649–56. http://dx.doi.org/10.1017/s0031182007002958.
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SUMMARYThis study analyses the anti-proliferative effect of lemongrass essential oil and its main constituent (citral) on all 3 evolutive forms ofTrypanosoma cruzi. Steam distillation was used to obtain lemongrass essential oil, with chemical composition determined by gas chromatography (GC) and GC coupled to mass spectrometry (GC-MS). The IC50/24 h (concentration that reduced the parasite population by 50%) of the oil and of citral uponT. cruziwas determined by cell counting in a Neubauer chamber, while morphological alterations were visualized by scanning and transmission electron microscopy. Treatment with the essential oil resulted in epimastigote growth inhibition with IC50=126·5 μg/ml, while the IC50for trypomastigote lysis was 15·5 μg/ml. The IC50/48 h for the Association Index (% macrophage infection×number of amastigotes per cell) was 5·1 μg/ml, with a strong inhibition of intracellular amastigote proliferation. Ultrastructural analysis demonstrated cytoplasmic and nuclear extraction, while the plasma membrane remained morphologically preserved. Our data show that lemongrass essential oil is effective againstT. cruzitrypomastigotes and amastigotes, and that its main component, citral, is responsible for the trypanocidal activity. These results indicate that essential oils can be promising anti-parasitic agents, opening perspectives to the discovery of more effective drugs of vegetal origin for treatment of parasitic diseases. However, additional cytotoxicity experiments on different cell lines and tests in aT. cruzi-mouse model are needed to support these data.
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Lin, Ying Cheng, Wei-Kai Wu, Suraphan Panyod, Ming-Shiang Wu, and Lee-Yan Sheen. "The Protective Effect of Garlic Essential Oil in Carnitine-Induced Cardiovascular Disease apoE-/- Mice Model." Current Developments in Nutrition 4, Supplement_2 (May 29, 2020): 1572. http://dx.doi.org/10.1093/cdn/nzaa062_029.
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Abstract Objectives High consumption of red meat can lead to cardiovascular disease. L-carnitine is rich in red meat can be metabolized by gut microbiota and hepatic enzyme to produce trimethylamine N-oxide (TMAO), which is the risk factor for cardiovascular disease. Garlic is a traditional food, exhibiting a medicinal effect against many diseases as well as garlic essential oil (GEO) possess anti-oxidation, anti-inflammation, and anti-hyperlipidemic effects to prevent cardiovascular disease. The purpose of this study is to investigate the protective effects of GEO on cardiovascular disease as well as explore the mechanism via modulation of gut microbiota composition and ameliorating lipid profiles. Methods GEO was extracted by steam distillation and its chemical constituents were analyzed by gas chromatography. The eight-week-old female apoE−/− mice were randomly divided into 5 groups: (1) chow diet, (2) 1.3% carnitine in water-fed group (negative control), (3) 1.3% carnitine + GEO (25 mg/kg bw), (4) 1.3% carnitine + GEO (50 mg/kg bw), and (5) 1.3% carnitine + 1% 3,3-dimethyl-1-butanol in water-fed (positive control). The mice were gavaged with GEO or soybean oil daily after 15 weeks the mice were sacrificed. The whole aorta was collected for observing the aortic plaque formation via oil red staining. The serum cholesterol, triglyceride, HDL, AST, and ALT were measured by an automatic blood analyzer. The bacterial metabolite trimethylamine (TMA) and TMAO were examined by using LC-MS. Illumina Miseq platform was used for 16S rDNA sequencing to analyze the feces microbiota composition. Results GEO significantly reduced the atherosclerotic lesion area in aorta compared to the carnitine-fed group (P < 0.01) and the effect is better than positive control. The serum HDL was improved by GEO (P < 0.01), but no change in serum total cholesterol level. The principal coordinate analysis of feces microbial composition revealed the differences in the gut microbiota composition. The carnitine and GEO shaped the feces microbiota alpha diversity. However, there are no significant findings in bacterial metabolites. Thus, the mechanistic effect of GEO against cardiovascular disease is mainly through the modulation of serum lipidomic. Conclusions GEO can serve as a functional food to prevent cardiovascular disease risk from high intake of red meat. Funding Sources MOST 108-2321-B-002 -035.
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Mitropoulou, Gregoria, Marianthi Sidira, Myria Skitsa, Ilias Tsochantaridis, Aglaia Pappa, Christos Dimtsoudis, Charalampos Proestos, and Yiannis Kourkoutas. "Assessment of the Antimicrobial, Antioxidant, and Antiproliferative Potential of Sideritis raeseri subps. raeseri Essential Oil." Foods 9, no. 7 (July 1, 2020): 860. http://dx.doi.org/10.3390/foods9070860.
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The aim of the present study was to investigate the antimicrobial potential of Sideritis raeseri subps. raeseri essential oil (EO) against common food spoilage and pathogenic microorganisms and evaluate its antioxidant and antiproliferative activity. The EO was isolated by steam distillation and analyzed by GC/MS. The main constituents identified were geranyl-p-cymene (25.08%), geranyl-γ-terpinene (15.17%), and geranyl-linalool (14.04%). Initially, its activity against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Listeria monocytogenes, Salmonella Enteritidis, Salmonella Typhimurium, Pseudomonas fragi, Saccharomyces cerevisiae, and Aspergillus niger was screened by the disk diffusion method. Subsequently, minimum inhibitory concentration (MIC), non-inhibitory concentration (NIC), and minimum lethal concentration (MLC) values were determined. Growth inhibition of all microorganisms tested was documented, although it was significantly lower compared to gentamycin, ciproxin, and voriconazole, which were used as positive controls. In a next step, its direct antioxidant properties were examined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, and the IC50 values were determined. The potential cytoprotective activity of the oil against H2O2–induced oxidative stress and DNA damage was studied in human immortalized keratinocyte (HaCaT) cells using the comet assay. Finally, the antiproliferative activity of the oil was evaluated against a panel of cancer cell lines including A375, Caco2, PC3, and DU145 and the non-cancerous HaCaT cell line using the sulforhodamine B (SRB) assay, and the EC50 values were determined. The oil demonstrated weak radical scavenging activity, noteworthy cytoprotective activity against H2O2–induced oxidative stress and DNA damage in HaCaT cells, and antiproliferative activity against all cell lines tested, being more sensitive against the in vitro model of skin melanoma.
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Boukhatem, Mohamed Nadjib, Thangirala Sudha, Noureldien H. E. Darwish, Henni Chader, Asma Belkadi, Mehdi Rajabi, Aicha Houche, Fatma Benkebailli, Faiza Oudjida, and Shaker A. Mousa. "A New Eucalyptol-Rich Lavender (Lavandula stoechas L.) Essential Oil: Emerging Potential for Therapy against Inflammation and Cancer." Molecules 25, no. 16 (August 12, 2020): 3671. http://dx.doi.org/10.3390/molecules25163671.
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Background/Aim: natural products are a potential source for drug discovery and development of cancer chemoprevention. Considering that drugs currently available for the treatment of inflammatory and cancer conditions show undesirable side effects, this research was designed to evaluate, for the first time, the in vitro anticancer activity of Algerian Lavandula stoechas essential oil (LSEO) against different cancer cell lines, as well as its in vitro and in vivo topical and acute anti-inflammatory properties. Materials and Methods: the LSEO was extracted by steam distillation, and chemical composition analysis was performed using gas chromatography. The main compounds identified in LSEO were oxygenated monoterpenes, such as 1,8-Cineole (61.36%). LSEO exhibited a potent anti-inflammatory activity using the xylene-induced mouse ear edema model. Results: LSEO (200 and 20 mg/kg) was able to significantly reduce (p < 0.05) the carrageenan-induced paw edema with a similar effect to that observed for the positive control. Topical application of LSEO at doses of 82 and 410 mg/kg significantly reduced acute ear edema in 51.4% and 80.1% of the mice, respectively. Histological analysis confirmed that LSEO inhibited the skin inflammatory response. Moreover, LSEO was tested for its antitumor activity against different cancer cell lines. LSEO was found to be significantly active against human gastric adenocarcinoma (AGS), Melanoma MV3, and breast carcinoma MDA-MB-231 cells, with median inhibitory concentration (IC50) values of 0.035 ± 0.018, 0.06 ± 0.022 and 0.259 ± 0.089 µL/mL, respectively. Altogether, these results open a new field of investigation into the characterization of the molecules involved in anti-proliferative processes. Conclusion: We suggest that LSEO, with 1,8-Cineole as the major active component, is a promising candidate for use in skin care products with anti-inflammatory and anticancer properties. The results of this study may provide an experimental basis for further systematic research, rational development, and clinical utilization of lavender resources.
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Mektrirat, Raktham, Terdsak Yano, Siriporn Okonogi, Wasan Katip, and Surachai Pikulkaew. "Phytochemical and Safety Evaluations of Volatile Terpenoids from Zingiber cassumunar Roxb. on Mature Carp Peripheral Blood Mononuclear Cells and Embryonic Zebrafish." Molecules 25, no. 3 (January 30, 2020): 613. http://dx.doi.org/10.3390/molecules25030613.
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Pharmaceutical products of essential oil from Zingiber cassumunar Roxb. are extensively being developed, while the research on their safety is seldom documented. The aim of the present study was to evaluate the phytochemical profile and the effect of cassumunar ginger oil on cell-based assay and the zebrafish model. The essential oil was isolated from fresh rhizomes of Z. cassumunar using simultaneous steam-distillation. Chemical composition was analyzed using gas chromatograph coupled to a mass spectrometer (GC-MS). Effect of cassumunar ginger oil on adult carp fish peripheral blood mononuclear cells (PBMCs) was investigated using MTT assay. The embryotoxic and teratogenic effects of cassumunar ginger oil were studied in zebrafish embryos. GC-MS results showed that the essential oil was composed of sabinene (43.54%) and terpinen-4-ol (29.52%) as the major phytoconstituents. No fish PBMC cytotoxic effect was observed with the concentration less than 50 µg/mL of cassumunar ginger oil. Our results showed for the first time the embryotoxic and teratogenic effects of cassumunar ginger oil in zebrafish embryos. The result indicated that the cassumunar ginger oil induced zebrafish embryotoxicity in a concentration-dependent manner. At 500 µg/mL of cassumunar ginger oil demonstrated significantly moderated embryotoxicity within 24 h (p < 0.05). The survival rate of 100 µg/mL of cassumunar ginger group was markedly declined to zero at 96-h post-fertilization (log-rank test, p = 0.001). However, survival rates of zebrafish embryo in the 1 and 10 µg/mL cassumunar ginger groups were more than 90% throughout the trial period. Moreover, very low teratogenicity to the zebrafish embryo was also observed in 1 and 10 µg/mL of cassumunar ginger groups. Our findings suggest that there is hardly any cytotoxicity, embryotoxicity and teratogenicity at concentrations less than 10 µg/mL of cassumunar ginger oil. However, the toxicity assessment of its pharmaceutical product should prove for further consumer protection.
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Macías-Hernández, José J., Plamen Angelov, and Xiao Wei Zhou. "Using Evolving Fuzzy Models to Predict Crude Oil Distillation Side Streams." Applied Mechanics and Materials 88-89 (August 2011): 432–37. http://dx.doi.org/10.4028/www.scientific.net/amm.88-89.432.
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Prediction of the properties of the crude oil distillation side streams based on statistical methods and laboratory-based analysis has been around for decades. However, it is difficult to identify, control or compensate the dynamic process behavior and the errors from instrumentation for an online model prediction. The objective of this work is to report an application and a study of a novel technique for real-time modelling, namely eXtended Evolving Fuzzy Takagi-Sugeno models (xTS) for prediction and online monitoring of these properties of the refinery distillation process. The results include the online prediction of Soft Sensors for distillation of Naptha and Gasoil Side Streams. The application predicts the quality of the side stream evolving its fuzzy structure and cluster parameters.
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Ferreira, Newton Libanio, Ingrid Ramos Alegre Chic, Juliana Mazarin Aguiar, Rodrigo Seiji Ota, and Thais Ribeiro Costa. "ESTUDO DA SEPARAÇÃO ISOBUTANO HEXENO: UM CASO REAL DE INDÚSTRIA PETROQUÍMICA." Journal of Engineering and Exact Sciences 4, no. 1 (March 2, 2018): 0109–16. http://dx.doi.org/10.18540/jcecvl4iss1pp0109-0116.
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Este trabalho visou o estudo e otimização do método de recuperação de isobutano e hexeno em uma coluna de destilação. Essa coluna faz parte do processo de obtenção de polietileno de alta densidade em uma indústria petroquímica. Para realizar a simulação do processo foram utilizados os softwares ASPEN PLUS, ASPEN DYNAMICS e também os dados do processo, o que possibilitou uma simulação com as condições esperadas para assim analisar as causas dos problemas apresentados e propor melhorias no seu funcionamento. Para o estudo do comportamento da coluna em regime estacionário foi necessário definir o modelo termodinâmico mediante análises de composição das correntes de alimentação e dados da pressão de operação. Com base no novo ponto de operação e na restrição do vapor do refervedor, projetou-se um novo refervedor, com o intuito de aumentar a área de troca térmica, suprindo a deficiência energética do processo. Outra opção, visando a minimização de custo, foi o projeto de um refervedor idêntico ao existente para operar em paralelo com o mesmo. Por fim avalia-se o controle existente e propõe-se um controle de nível de fundo da coluna através da vazão de fundo, controle de temperatura de fundo da coluna manipulando a carga térmica do refervedor e controle da retirada lateral, alterando-se o set point do estágio 24 para o estágio 31, obtendo-se uma resposta mais rápida frente a distúrbio na corrente de alimentação e garantindo uma composição de hexeno elevada na retirada lateral.This work aimed the study and optimization the recovery method of isobutane and hexene in a distillation column. This column is part of the process to obtain high density polyethylene in a petrochemical industry. To carry out the simulation of the process, the software ASPEN PLUSÒ, ASPEN DYNAMICSÒ and the process data were used, which enabled a simulation with the expected conditions to analyze the causes of the presented problems and propose improvements in its operation. For study the behavior of the column in steady state, it was necessary to define the thermodynamic model by analyzing the composition of the feed currents and the operating pressure data. Based on the new operating point and the steam restriction of the referent, a new reboiler was designed with the purpose of increasing the area of thermal exchange, supplying the energy deficit of the process. Another option, aiming the cost minimization, was the design of an identical reboiler to the existing to operate in parallel with it. Finally, the existing control is evaluated, and it is proposed a background level control of the column through the bottom flow, control of the bottom temperature of the column manipulating the thermal load of the reboiler and control of lateral withdrawal, changing the set point from stage 24 to stage 31, resulting in a better response to the disturbance in the feed stream and ensuring a high hexene composition in lateral withdrawal.
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Liu, Yu, Chun Hai Yi, Jia Yang Hu, and Bo Lun Yang. "Gasoline Desulfurization with Two Catalytic Distillation Columns." Advanced Materials Research 550-553 (July 2012): 550–53. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.550.
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A new approach was proposed to remove sulfuric compounds from fluid catalytic cracking (FCC) gasoline by combining an alkylation desulfurization catalytic distillation (ADCD) column with a hydrodesulfurization catalytic distillation (HDS-CD) column. In the ADCD column, isobutylene (IB) and 3-methylthiophene (3MT) were designated as the model compounds for olefin and sulfide, respectively; NKC-9 cation exchange resin was used as the catalyst. In the HDS-CD column, dibenzothiophene (DBT) was chosen as the model sulfides; Nickel phosphide supported on the TiO2-Al2O3 composite oxide prepared by our laboratory were designated as the HDS catalyst. Simulations for these two CD columns were carried out by RADFRAC module of Aspen Plus. The optimization results revealed that the ADCD column had an alkylation selectivity of 96%, and the sulfur content in the overhead stream was less than 8 μg/g. The simulation results of the HDS-CD process showed that the sulfide in the bottom stream of ADCD column can be removed practically by 100% and the clean oil stream from the bottom of HDS-CD column has hardly any sulfur.
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Piao, Yongri, Zhengkun Rong, Miao Zhang, and Huchuan Lu. "Exploit and Replace: An Asymmetrical Two-Stream Architecture for Versatile Light Field Saliency Detection." Proceedings of the AAAI Conference on Artificial Intelligence 34, no. 07 (April 3, 2020): 11865–73. http://dx.doi.org/10.1609/aaai.v34i07.6860.
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Light field saliency detection is becoming of increasing interest in recent years due to the significant improvements in challenging scenes by using abundant light field cues. However, high dimension of light field data poses computation-intensive and memory-intensive challenges, and light field data access is far less ubiquitous as RGB data. These may severely impede practical applications of light field saliency detection. In this paper, we introduce an asymmetrical two-stream architecture inspired by knowledge distillation to confront these challenges. First, we design a teacher network to learn to exploit focal slices for higher requirements on desktop computers and meanwhile transfer comprehensive focusness knowledge to the student network. Our teacher network is achieved relying on two tailor-made modules, namely multi-focusness recruiting module (MFRM) and multi-focusness screening module (MFSM), respectively. Second, we propose two distillation schemes to train a student network towards memory and computation efficiency while ensuring the performance. The proposed distillation schemes ensure better absorption of focusness knowledge and enable the student to replace the focal slices with a single RGB image in an user-friendly way. We conduct the experiments on three benchmark datasets and demonstrate that our teacher network achieves state-of-the-arts performance and student network (ResNet18) achieves Top-1 accuracies on HFUT-LFSD dataset and Top-4 on DUT-LFSD, which tremendously minimizes the model size by 56% and boosts the Frame Per Second (FPS) by 159%, compared with the best performing method.
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Ma, Zhao Qin, Shu Hao Huo, and Min Su. "Simulation with Aspen Plus and Performance Analysis of LT-MED Seawater Desalination System." Applied Mechanics and Materials 397-400 (September 2013): 948–56. http://dx.doi.org/10.4028/www.scientific.net/amm.397-400.948.
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With Aspen Plus, three simulation models for Low-Temperature Multi-Effect Distillation (LT-MED) seawater desalination system are established in this work, which includes the parallel flow, forward flow and backward flow processes. Performance analysis including the motive steam flow, Gained Output Ratio (GOR) and heat transfer area are conducted as a function of the process type, number of effects, heating steam temperature and the effect NO. for Thermal Vapor Compression (TVC) ejection. Results indicate that the established simulation models are accurate and reliable; the process type, the number of effects and the effect NO. for TVC ejection have a great impact on the performance, while the effect of heating steam temperature on the performance is relatively weaker.
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Ge, Yu Lin, Ping Wang, Sheng Qiang Shen, and Jun Liang Xu. "Synthesis Method of Heat Exchanger Network for Distillation Device." Advanced Materials Research 199-200 (February 2011): 1509–12. http://dx.doi.org/10.4028/www.scientific.net/amr.199-200.1509.
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Mathematical programming model for synthesis of heat exchanger network for distillation unit is established. MINLP problem for heat exchanger network is solved by branch-bound method. Two kinds of heat exchanger network with splitting stream and without splitting stream are obtained. 142 heat exchangers, 8 coolers and 4 heaters are needed in the heat exchanger network without splitting stream. 34 heat exchangers, 8 coolers, 4 heaters, 11 splitters and 11 mixers are needed in the heat exchanger network with splitting stream. The matching situation including heat load, heat exchange area, duty of utilities, flow fraction of splitting, temperature of inlet and outlet, etc. for cold and hot streams in the heat exchanger network with splitting stream is presented in detail, Analysis the relationship between total heat exchange area, total heat load, total capital cost and annual operation cost of the heat exchanger network. Taking the number of heat exchangers and operational flexibility of heat exchange network into consideration, the heat exchanger network with splitting stream is suggested to be selected.
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Golovanchikov, A. B., and N. A. Prokhorenko. "Modeling of the Structure of Flows in a Nozzle Rectification Column by the Velocity Profile of the Steam Phase." Oil and Gas Technologies 135, no. 4 (2021): 46–49. http://dx.doi.org/10.32935/1815-2600-2021-135-4-46-49.
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An algorithm has been developed for calculating the main parameters of the flow structure by the velocity profile of the boiling liquid phase in a packed distillation column: differential and integral response and dispersion functions without determining the response curves by the indicator method. An example of the calculation of the above parameters and modeling according to standard and combined models is given: cell, one-parameter diffusion and with a series connection of zones of displacement and mixing.
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Zheljazkov, Valtcho D., Tess Astatkie, Santosh Shiwakoti, Shital Poudyal, Thomas Horgan, Natasha Kovatcheva, and Anna Dobreva. "Essential Oil Yield and Composition of Garden Sage as a Function of Different Steam Distillation Times." HortScience 49, no. 6 (June 2014): 785–90. http://dx.doi.org/10.21273/hortsci.49.6.785.
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Garden sage (Salvia officinalis L.) is a medicinal, culinary, ornamental, and essential oil plant with a wide range of ecological adaptation. Garden sage essential oil traditionally is extracted by steam distillation from the above-ground biomass and has widespread applications as an aromatic agent in the food and pharmaceutical industries as well as in perfumery and cosmetics. The hypothesis of this study was that the steam distillation time (DT) may significantly affect essential oil yield and composition of garden sage and, therefore, DT could be used as a tool to obtain oil with different composition. Therefore, the objective was to evaluate the effect of various steam DTs (1.25, 2.5, 5, 10, 20, 40, 80, and 160 minutes) on garden sage oil yield and composition. Most of the oil in the garden sage dry herbage was extracted in 10-minute DT; extending DT up to 160 minutes did not significantly increase oil yields. Overall, 39 oil constituents were identified in the garden sage essential oil. Fourteen oil constituents with the highest concentration in the oil were selected for statistical analyses. Monoterpenes represented the major percentage (58.2% to 84.1%) of oil composition followed by sesquiterpenes (4.0% to 16.1%) and diterpenes (0.3% to 7.6%). Overall, the monoterpene hydrocarbons (α-pinene, camphene, β-pinene, myrcene, and limonene) were eluted early in the steam distillation process, which resulted in their high concentration in the oil at 5- to 10-minute DT and relatively low concentrations in the oil obtained at 160-minute DT. In general, the concentration of sesquiterpenes (β-caryophyllene, α-humulene, and verdifloral) increased with increasing duration of the DT and reached their respective maximum concentrations in the oil at 160-minute DT. The relative concentrations of major constituents, camphor and cis-thujone, in the oil obtained at 2.5-minute DT were higher than in the oils obtained at longer DT. Therefore, if oil with high concentrations of camphor and cis-thujone is desirable, garden sage dried biomass ought to be steam distilled for 2.5 to 5 minutes and the oil collected. If oil with a high concentration of monoterpene hydrocarbons and a high concentration of oxygenated monoterpenes is desirable, then garden sage should be distilled for 20 minutes. If oil with a high concentration of the diterpene manool is desirable, then garden sage should be steam-distilled for 80 minutes. If oil with a high concentration of sesquiterpenes is desirable, then garden sage should be steam-distilled for 160 minutes. The duration of steam distillation can be used as an economical method to obtain garden sage oil with a different chemical composition. The regression models developed in this study can be used to predict garden sage oil yield and composition distilled for various amounts of time and to compare literature reports in which different durations of DT were used.
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Šulgan, Branislav, Juraj Labovský, and Zuzana Labovská. "Multi-Aspect Comparison of Ethyl Acetate Production Pathways: Reactive Distillation Process Integration and Intensification via Mechanical and Chemical Approach." Processes 8, no. 12 (December 8, 2020): 1618. http://dx.doi.org/10.3390/pr8121618.
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This paper provides a multi-aspect comparison of selected methods of ethyl acetate production and shows the possibility of further reactive distillation process integration and sophisticated intensification including process stream regeneration. The production pathways were selected with respect to their practical applicability and sufficient experimental and feasibility studies already published. A total of four case studies were designed and compared: conventional process set-up (ethyl acetate is produced in a chemical reactor) is designed as a base case study; reactive distillation with a separation unit is derived from the conventional process set-up. The mechanical and chemical approach to reactive distillation process intensification and integration were assumed: reactive distillation column with a stripper and reactive distillation column with an auxiliary chemical reaction (ethylene oxide hydration). Process models were compiled in the Aspen Plus software. Complex process flowsheets of selected case studies including separation and regeneration were designed and optimized. Three different points of view were applied to evaluate the selected process benefits and drawbacks. Process energy, economy, and safety were assessed. As a result, a reactive distillation column with an auxiliary chemical reaction has been proven to be the most suitable pathway for ethyl acetate production assuming all three evaluated aspects.
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Ting, K. E., H. T. Ng, and H. C. Li. "Reducing Energy Consumption for Seawater Desalination through the Application of Reflux-Recycle Concepts from Oil Refining." Applied Mechanics and Materials 295-298 (February 2013): 1456–62. http://dx.doi.org/10.4028/www.scientific.net/amm.295-298.1456.
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The application of the concepts in oil and gas distillation to membrane desalination process to lower the energy cost for seawater desalination was studied in this paper. Drawing on the close analogy between multistage RO and conventional distillation separation processes, a hybrid membrane processes employing reflux and recycle concepts was developed. Reflux in membrane processes involves taking a portion of the effluent stream on the high pressure side and sending it to the low pressure side of the membrane, while recycle involves taking a portion of the permeate stream on the low pressure side and sending it to the high pressure side of the membrane. A predictive model was developed to study the effect of reflux and recycle on the specific energy consumption (SEC) and permeate quality when compared to conventional systems. In this study, the water permeability coefficients of membranes and brine recycle ratios were investigated. The results show that the SEC for a hybrid membrane processes comprising of RO and NF membrane was lower than conventional methods with the same recovery and feed concentration, suggesting that it is feasible to apply reflux and recycle concepts of distillation on desalination. Through the careful selection of RO membranes and NF membranes, benefits of reflux and recycle can be enjoyed for seawater desalination.
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Jorge, Luiz Mario de Matos, Patrícia Aparecida Polli, Douglas Junior Nicolin, Regina Maria Matos Jorge, Paulo Roberto Paraíso, and Rubens Maciel Filho. "SIMULATION AND ANALYSIS OF AN INDUSTRIAL COLUMN SYSTEM OF BIOETHANOL DISTILLATION HEATED BY VAPOR DIRECT INJECTION." Engevista 17, no. 2 (January 1, 2015): 254. http://dx.doi.org/10.22409/engevista.v17i2.657.
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Most commercial process simulators have its origin at the petrochemical industry and their use in other sectors depends on testing. In this context a model of an industrial column system of bioethanol distillation heated by direct injection of vapor was developed and implemented using the simulator Aspen HYSYS, which was compared with experimental data obtained in the industrial plant. The system basically consists of four columns heated by direct vapor injection and the model of the system was developed using this approach together with the simulation blocks for columns heated by reboilers available on Aspen HYSYS. For such a task it was admitted a null termal load for the reboiler and a direct vapor stream was added in the side of the column. Overall deviations between simulated values and those measured in the distillery were 2.3 % for temperatures, 12.95 % for concentrations, and 1.07 % for bioethanol production in the industrial distillation system (IDS). The low values of the deviations obtained when comparing the data of the real process with simulated data indicate that IDS is well sized and the model implemented as well as the process simulator adopted can be used in the sugar-ethanol industry with distillation columns heated by direct injection of vapor.
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Min, Shaobo, Xuejin Chen, Zheng-Jun Zha, Feng Wu, and Yongdong Zhang. "A Two-Stream Mutual Attention Network for Semi-Supervised Biomedical Segmentation with Noisy Labels." Proceedings of the AAAI Conference on Artificial Intelligence 33 (July 17, 2019): 4578–85. http://dx.doi.org/10.1609/aaai.v33i01.33014578.
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Learning-based methods suffer from a deficiency of clean annotations, especially in biomedical segmentation. Although many semi-supervised methods have been proposed to provide extra training data, automatically generated labels are usually too noisy to retrain models effectively. In this paper, we propose a Two-Stream Mutual Attention Network (TSMAN) that weakens the influence of back-propagated gradients caused by incorrect labels, thereby rendering the network robust to unclean data. The proposed TSMAN consists of two sub-networks that are connected by three types of attention models in different layers. The target of each attention model is to indicate potentially incorrect gradients in a certain layer for both sub-networks by analyzing their inferred features using the same input. In order to achieve this purpose, the attention models are designed based on the propagation analysis of noisy gradients at different layers. This allows the attention models to effectively discover incorrect labels and weaken their influence during parameter updating process. By exchanging multi-level features within two-stream architecture, the effects of noisy labels in each sub-network are reduced by decreasing the noisy gradients. Furthermore, a hierarchical distillation is developed to provide reliable pseudo labels for unlabelded data, which further boosts the performance of TSMAN. The experiments using both HVSMR 2016 and BRATS 2015 benchmarks demonstrate that our semi-supervised learning framework surpasses the state-of-the-art fully-supervised results.
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Gawde, Archana, Charles L. Cantrell, Valtcho D. Zheljazkov, Tess Astatkie, and Vicki Schlegel. "Steam distillation extraction kinetics regression models to predict essential oil yield, composition, and bioactivity of chamomile oil." Industrial Crops and Products 58 (July 2014): 61–67. http://dx.doi.org/10.1016/j.indcrop.2014.04.001.
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Bogdan, Claudia, Catalin Brill, Oleksandr Sirosh, Mihai Vijulie, and Alin Lazar. "PRELIMINARY DEVELOPMENT OF A CONCEPTUAL MODEL OF MATRIX HEAT EXCHANGER." SMART ENERGY AND SUSTAINABLE ENVIRONMENT 24, no. 1 (April 16, 2021): 29–40. http://dx.doi.org/10.46390/j.smensuen.24121.435.
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While the basic principles of thermodynamics have remained the same, the necessity for heat exchangers to have good effectiveness in a small volume is constantly growing. Heat exchangers type Matrix Heat Exchanger (MHE), which can meet these requirements, does not have an optimal design variant for its use. These heat exchangers have been approached for 60 years, by many researchers, currently offering only an overview of the process. The mechanism of heat transfer in a matrix heat exchanger is complex, having three different thermal convection paths as well as thermal conduction through two different surfaces. This paper presents the simulations performed in ANSYS Workbench, combining all these heat transfer modes, for developing an optimal model of a perforated plate matrix heat exchanger, used for the pre-cooling of a hydrogen isotopes stream mixture, for purification purposes, as well as, for preparing the inlet temperature in cryogenic distillation columns of hydrogen isotopes.
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Idris, R., N. Harun, and Mohamad Rizza Othman. "A port-stream based equation oriented modelling of complex distillation column: A dividing wall column case study." Applied Chemical Engineering 3, no. 2 (December 9, 2020): 68. http://dx.doi.org/10.24294/ace.v3i2.588.
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Dividing wall column (DWC) offers higher degree of freedom in comparison with the conventional column. Furthermore, the different sections configurations within the column are highly interacting with several recycle loops. Facing with such complex unit operation, describing its behaviour encourages the focal point on the resolution of ideal modelling approaches. Equation oriented (EO) modelling of DWC has been studied by several researchers involving complex algorithm and methodology. In this work, a new approach for modelling of DWC is presented. The modelling methodology involves variables connectivity based on ports and streams that is admissible to equation-oriented flow sheet. To verify the functionality of the proposed method, the modelled DWC is validated with two case studies depicted from experimental literature data to separate alcohol mixture and fatty acid fractionation. The model development was performed in MOSAIC, a web-based modelling tool and run in gPROMS. The model shows good convergence and has less than 10% error when compared to the above mentioned case studies. To furthermore extend the model capability, relative gain array (RGA) analysis was conducted for the fatty acid fractionation to determine the best control configuration in DWC. Result shows that L-S-V and L-S-B configurations are the best control configurations. Our analysis also shows that reflux flowrate, side flowrate and vapor boilup are best to control distillate product, side product and bottom product, respectively.
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Zheljazkov, Valtcho D., Tess Astatkie, Barry O'Brocki, and Ekaterina Jeliazkova. "Essential Oil Composition and Yield of Anise from Different Distillation Times." HortScience 48, no. 11 (November 2013): 1393–96. http://dx.doi.org/10.21273/hortsci.48.11.1393.
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Anise (Pimpinella anisum L.) is a spice, an essential oil crop, and a medicinal plant with a long history of use. Anise seed oil is extracted from anise seed through steam distillation. There is no experimentally established optimal time for distillation of anise seed. We hypothesized that the distillation time (DT) can be customized for optimum yield and composition of anise essential oil. In this study, we determined the effect of nine steam DTs (5, 15, 30, 60, 120, 180, 240, 360, and 480 minutes) on essential oil yield and essential oil composition of anise seed. We developed regression models to predict essential oil yield, the concentration of individual constituents, and the yield of these constituents as a function of DT. Highest essential oil yield (2.0 g/100 g seed, 2%) was obtained at 360-minute DT. The concentration of transanethole, the major anise oil constituent, varied from 93.5% to 96.2% (as a percent of the total oil) and generally was high at 15- to 60-minute DT and low at 240- to 480-minute DT. However, the yield of transanethole (calculated from the essential oil yield and the concentration of transanethole in the oil) increased with increasing DT to reach maximum at 360-minute DT. The concentration of the other oil constituents varied significantly depending on the DT, and some of them were higher at the shorter DT than at the longer DT. However, the yields of these constituents were highest at longer DT (either 360 or 480 minutes). DT can be used to obtain anise essential oil with different composition that would benefit the essential oil industry. This study demonstrated the need for providing DT in reports where anise seed essential oil yield and composition are discussed. This article can also be used as a reference point for comparing studies in which different DTs were used to extract essential oil from anise seed.
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Et. al., M. Shanmuganathan,. "ROBUST K-NEAREST NEIGHBOR CLASSIFIER AND NEAREST MEAN CLASSIFIER BASED INFORMATIVE KNOWLEDGE DISTILLATION FACE RECOGNITION." INFORMATION TECHNOLOGY IN INDUSTRY 9, no. 2 (March 25, 2021): 418–24. http://dx.doi.org/10.17762/itii.v9i2.365.
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Human Face identification procedures have made tremendous progress in the last decade. Nevertheless, identifying faces with incomplete impediment is as yet challenging for the present face identifiers, and is very much required within certifiable application programs regarding reconnaissance and protection. Though great examination exertion has been dedicated to creating face de-impediment techniques, the greater part of them can just function admirably under obliged conditions. In this manuscript is proposed a Robust K-NNC (K-Nearest Neighbor Classifier) and NMC(Nearest Mean Classifier ) (RKNNC-NMC) prototype to efficiently reestablish incompletely occluded faces even in nature. This model comprises of two-stream, first introduced to perceive high-resolution faces and goal corrupted appearances with a student stream and a teacher stream, separately. A Teacher stream is signified by a Complex RKNNC-NMC for the sake of high-exactness recognition, and the student stream is signified by an a lot more straightforward RKNNC-NMC for low-unpredictability recognition. Broad examinations on synthetic and real datasets datasets of countenances with impediment plainly show the viability of RKNNC-NMC in eliminating various kinds of impediment in one’s face at different locations. The suggested technique additionally gives better behaviour gain than other de-occlusion strategies in advancing recognition execution through partially-occluded faces.
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Berdowska, Sylwia, and Anna Skorek-Osikowska. "Technology of oxygen production in the membranecryogenic air separation system for a 600 MW oxy-type pulverized bed boiler." Archives of Thermodynamics 33, no. 3 (September 1, 2012): 61–72. http://dx.doi.org/10.2478/v10173-012-0018-8.
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Abstract In this paper the results of the thermodynamic analysis of the oxy-combustion type pulverized bed boiler integrated with a hybrid, membrane- cryogenic oxygen separation installation are presented. For the calculations a 600 MW boiler with live steam parameters at 31.1 MPa /654.9 oC and reheated steam at 6.15 MPa/672.4 oC was chosen. In this paper the hybrid membrane-cryogenic technology as oxygen production unit for pulverized bed boiler was proposed. Such an installation consists of a membrane module and two cryogenic distillation columns. Models of these installations were built in the Aspen software. The energy intensity of the oxygen production process in the hybrid system was compared with the cryogenic technology. The analysis of the influence of membrane surface area on the energy intensity of the process of air separation as well as the influence of oxygen concentration at the inlet to the cryogenic installation on the energy intensity of a hybrid unit was performed.
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Yakhyaev, M. A., V. S. Gutenkov, C. A. Cardona, and Yu A. Pisarenko. "Development of Reaction-Rectification Process of Obtaining Mesityl Oxide. II. Analysis of Statics and Modeling of the Process." Fine Chemical Technologies 14, no. 2 (May 20, 2019): 23–32. http://dx.doi.org/10.32362/2410-6593-2019-14-2-23-32.
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Using the results of an earlier study of the physicochemical properties of the reaction system of the process of producing mesityl oxide, an analysis of the statics of the combined variant of the organization of this process was carried out. It is shown that of practical interest are the modes of the process corresponding to the first specified separation. In this case, the limiting stationary states, characterized by the maximum acetone conversion, selectivity, and the yield of the target product — mesityl oxide, are distinguished. The possibility of practical implementation of the limiting stationary state of the reactive distillation process for producing mesityl oxide, which provides almost complete conversion of acetone with a yield of mesityl oxide approaching 100%, has been proved. The limit stationary state corresponds to the reaction-distillation process with the selection of a single product stream. For the mode of carrying out the combined process that corresponds to the selected limiting stationary state, a schematic flow chart for the production of the target product has been proposed. By means of computational research, it has been established that the most rational option for organizing a reaction hub is to use a single apparatus in it — the reaction-distillation column. In the Aspen Plus® software package, a process model was constructed that corresponded to the proposed technological scheme and through a computational experiment, its structural and parametric optimization was carried out. As a result, the static parameters of the technological system were established, as well as the characteristics of the apparatuses, allowing to obtain the required quality product in the reactiondistillation column. output, approaching 100%. It has been shown that when modeling a chemicaltechnological system, it is necessary to use different sets of parameters of the basic equation used to describe phase equilibrium. Thus, for calculating reactive distillation and distillation columns, the liquid – vapor phase equilibrium parameters for the mesityl oxide–water system should be used, and when calculating the Florentine vessel for this mixture, it is necessary to use the parameters corresponding to the liquid – liquid equilibrium. The use of a single set of parameters of the basic equation leads to significant errors and inadequate description of the process of producing mesityl oxide by condensation of acetone.
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Zheljazkov, Valtcho D., Tess Astatkie, and Vicki Schlegel. "Distillation Time Changes Oregano Essential Oil Yields and Composition but Not the Antioxidant or Antimicrobial Activities." HortScience 47, no. 6 (June 2012): 777–84. http://dx.doi.org/10.21273/hortsci.47.6.777.
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Oregano (Origanum vulgare L.) is an important medicinal, culinary, and essential oil plant. Oregano essential oil is extracted from either leaves or shoots through steam distillation. Researchers and industry in various countries reported different distillation times (DTs) for oregano; however, there are no reports on optimum DT. This study evaluated the effect of DT (1.25, 2.5, 5, 10, 20, 40, 80, 160, 240, 360 min) on essential oil yield, composition, and antioxidant activity of the oregano essential oil. In general, the concentration of the low boiling essential oil constituents (alpha-thujene, alpha-pinene, camphene, l-octen-3-ol, myrcene, alpha-terpinene, paracymene, beta-phellandrene/limonene, gamma-terpinene, cis-sabinene hydrate, terpinolene) were highest at the shortest DT (1.25 or 2.5 min), reduced with increasing DT up to 40 min, and then stayed the same. However, the concentration of the major oil constituent, carvacrol, was lowest at the shortest DT of 1.25 min (18%) and increased steadily with increasing DT up to 40 min, where it leveled at 80% to 82%. The concentration of other higher boiling constituents (borneol, 4-terpineol, beta-bisabolene, beta-caryophylenne) was maximum at 5 to 20 min DT. Maximum yield of the low boiling constituents was achieved at relatively short DT, at ≈20 min DT, and peaked again at 240 min DT. Maximum yields of alpha-terpinene, beta-phellandrene/limonene, and gamma-terpinene were reached at 240 min DT. Maximum yields of paracymene cis-sabinene hydrate, terpinolene, and transsabinene hydrate were also achieved at 240 min DT, but yields at 20 min DT were not different. Yields of borneol, 4-terpinenol, carvacrol, beta-caryophyllene, and beta-bisabolene also were highest at 240 min DT. Distillation time at 20, 80, or 360 min did not alter antioxidant or antimicrobial activity of oregano oil. The relationship between the concentration and yield of the constituents with DT was adequately modeled by the asymptotic and Michaelis-Menten nonlinear regression models, respectively. Results demonstrated that 1) DT can be used to obtain oregano essential oil with differential composition; 2) maximum essential oil yield of steam-distilled oregano leaves could be obtained at 240 min DT; and 3) reports on oregano essential oil yield and composition using different DTs may not be comparable. Results from this study will aid in comparing published reports on oregano essential oil that used different lengths of DT.
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Ge, Shiming, Kangkai Zhang, Haolin Liu, Yingying Hua, Shengwei Zhao, Xin Jin, and Hao Wen. "Look One and More: Distilling Hybrid Order Relational Knowledge for Cross-Resolution Image Recognition." Proceedings of the AAAI Conference on Artificial Intelligence 34, no. 07 (April 3, 2020): 10845–52. http://dx.doi.org/10.1609/aaai.v34i07.6715.
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In spite of great success in many image recognition tasks achieved by recent deep models, directly applying them to recognize low-resolution images may suffer from low accuracy due to the missing of informative details during resolution degradation. However, these images are still recognizable for subjects who are familiar with the corresponding high-resolution ones. Inspired by that, we propose a teacher-student learning approach to facilitate low-resolution image recognition via hybrid order relational knowledge distillation. The approach refers to three streams: the teacher stream is pretrained to recognize high-resolution images in high accuracy, the student stream is learned to identify low-resolution images by mimicking the teacher's behaviors, and the extra assistant stream is introduced as bridge to help knowledge transfer across the teacher to the student. To extract sufficient knowledge for reducing the loss in accuracy, the learning of student is supervised with multiple losses, which preserves the similarities in various order relational structures. In this way, the capability of recovering missing details of familiar low-resolution images can be effectively enhanced, leading to a better knowledge transfer. Extensive experiments on metric learning, low-resolution image classification and low-resolution face recognition tasks show the effectiveness of our approach, while taking reduced models.
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Ebadi, M., M. R. Mozdianfard, and M. Aliabadi. "Employing full factorial design and response surface methodology for optimizing direct contact membrane distillation operational conditions in desalinating the rejected stream of a reverse osmosis unit at Esfahan refinery–Iran." Water Supply 19, no. 2 (May 10, 2018): 492–501. http://dx.doi.org/10.2166/ws.2018.094.
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Abstract Optimized condition for desalination of the reverse osmosis (RO) rejected stream from Esfahan Oil Refining Company (EORC) using direct contact membrane distillation (DCMD) with polytetrafluoroethylene (PTFE) membrane was investigated here, having designed a set of 34 experiments using response surface methodology (RSM) and full factorial design (FFD) modelling, carried out in a laboratory scale set-up built for this purpose. Statistical criteria for validation, significance, accuracy and adequacy confirmed the suitability of the quadratic polynomial model employed. Response plots and regression equations suggested that the permeate flux response improved with increased feed temperature, reduced permeate temperature and enhanced feed flow rate. Optimizing DCMD process showed that maximum permeate flux of 60.76 L/m2·h could be achieved at the following optimum operational conditions: feed temperature and flow rate of 70 °C and 2 L/min, respectively, as well as the permeate temperature of 15 °C. At this point, the mean annual energy required for 90% water recovery (36 m3/h off the RO brackish rejected stream) at EORC refinery was found to be 96 GJ, which could be supplied using solar or conventional energy systems at Isfahan, facing a very critical water shortage at present.