Pressure Extractor Research Articles

Analysis of influence of air-entry values to unsaturated soil properties

Soil slope instability is a grave concern in regions with high annual precipitation, especially in tropical countries. The impact of soil instability on the economies of these countries is severe since it usually causes fatalities and property loss. The research and development of the systems to reduce the impact of soil slope failures by predicting slope failure, monitoring the slope, and early failure warning has made it possible to implement safety measures. Despite the considerable effort to implement these measures, the factors contributing to soil slope instability are complex and have not been explored extensively. The air-entry value (AEV), which is the matric suction, is a critical factor in predicting the risk of slope instability. This paper will analyze the interaction of the basic soil properties and the soil hydraulic properties, also known as AEV. The researchers collected natural undisturbed soil samples from several locations to determine their AEVs which obtained by plate pressure extractor apparatus. The basic soil properties, namely the natural moisture content, particle size distribution and bulk density were determined in the laboratory, and the values were used to determine the correlation between the basic soil properties and the soil AEV. The results show that the soil with higher coefficient of curvature and percentage of sand have lower air-entry values, which mean they could experience disastrous slope failure during heavy rainfalls. This strong correlation underscores the significance of soil hydraulic properties as the critical factor in soil slope instability.

Optimization of Automated Sample Preparation for Vitamin D Determination on a Biomek i7 Workstation

Vitamin D belongs to the fat-soluble vitamins and is an integral part of bone metabolism. In the human body, a decreased vitamin D level can be an additional risk factor for diseases like cancer, diabetes, and mental diseases. As a result, an enormous increase in the demand for vitamin D testing has been observed in recent years, increasing the demand for powerful methods for vitamin D determination at the same time.Automation is the key factor in increasing sample throughput. This study compares three fully automated sample preparation methods for the determination of 25(OH)D2 and 25(OH)D3 in plasma and serum samples. Starting from a semiautomated reference method, the method is tested manually and subsequently fully automated on the Biomek i7 Workstation by integrating a centrifuge and a positive pressure extractor into the workstation. Alternatively, the centrifugation for the separation of protein aggregates and supernatant is replaced by a filter plate. Finally, the sample throughput is further increased by using phospholipid removal cartridges. The results show that phospholipid removal significantly increases the recovery rates in liquid chromatography-mass spectrometry. With the phospholipid removal cartridges, recovery rates of 97.36% for 25(OH)D2 and 102.5% for 25(OH)D3 were achieved, whereas with the automated classic automated preparation method, the recovery rates were 83.31% for 25(OH)D2 and 86.54% for 25(OH)D3. In addition to the technical evaluation, the different methods were also examined with regard to their economic efficiency. Finally, the qualitative and quantitative performance of the developed methods is benchmarked with a selected semiautomatic reference method.

DETERMINATION OF HYDRODYNAMIC PARAMETERS OF THE SEALED PRESSURE EXTRACTOR

The subject matter of the article: Sealed extractor with pressure. The goal of the work: Determination of hydrodynamic parameters of the sealed extractor with pressure. The following tasks were solved in the article: Theoretical research on the creation of a sealed extractor with pressure. It is need to development of ways of implementation and practical recommendations for the given technical solutions in the experimental sample. The following methods are used: Mathematical modeling, differential and integral calculus, experimental research methods. The following results were obtained: The processes occurring in sealed extractors are described mathematically. Parameters that affect the performance of aggregates are determined. Conclusions: As a result of the analysis of the technological process and equipment used in the factories for primary processing of wool, shortcomings and problems are identified and means for their elimination are proposed. It is proposed to use small-sized equipment to work on waste-free technology based on a hydrodynamic pressure extractor. Extraction as an efficient mass transfer process for removing organic components from aqueous solutions has the advantages of low operating temperatures and efficiency. The design features of the sealed pressure extractor are as follows: high angular velocities, the moment of inertia of rotating details, powerful pressure, the presence of nodes that provide a supply and discharge of liquids, tightness. The kinematic and geometric parameters of the rotor affect the sealed extractors’ performance). In sealed extractors, the heavy fraction in the field of centrifugal forces will accumulate on a large radius of the inner side of the rotor and for its movement it is necessary to create an excess pressure at the extractor inlet.

Artemisia annua organic solvent extract, processed by supercritical CO2

AbstractBACKGROUNDArtemisia annua L. extraction is traditionally performed using hexane; the process is simple, but not selective. In this work, a strategy to concentrate artemisinin and the other similar active principles in the final extract is proposed, combining cheapness of maceration and selectivity of SC‐CO2 processing.RESULTSHexane extraction produced a solid, waxy extract with a yield of 3.3% w/w with respect to the starting vegetable material. Then, SC‐CO2 processing of this solid extract was performed operating at 0.8 kg h−1 SC‐CO2 flow rate and at different operative parameters. Very selective conditions were found operating at 90 bar and 50°C, obtaining a final product containing more than 71% w/w of active compounds (artemisinin, artemisin and dehydroartemisinin).CONCLUSIONUsing this approach, a product more than 2.6 times richer in artemisinin than the one obtained by conventional techniques and about 2 times richer than direct CO2 extraction, was obtained. Another relevant result is that the overall process scheme is cheaper than direct CO2 extraction, since a high pressure extractor about 20 times smaller can be used, to process the waxy product obtained by hexane extraction. © 2018 Society of Chemical Industry

Effect of temperature on crude oil extraction by SC-CO2 at 40–70 °C and 40–60 MPa

The extraction process of crude oil by supercritical CO2 was simulated in a high pressure extractor at 40, 50, 60 and 70 °C, and at 20, 40 and 60 MPa in order to investigate the effect of temperature on oil recovery. The total recovery of oil increased by 30–40% at the pressure increase from 20 MPa to 60 MPa. The temperature effect on the total recovery at 40, 50 and 60 °C was insignificant while the total recovery increased by 10% as the temperature rose from 40 °C to 70 °C. The vapor recovery did not change substantially with the temperature and pressure increase at temperatures higher than 40 °C. The isotherms of liquid recovery formed a concave surface because of higher extraction results at 40 °C and 70 °C indicating a crossover pressure phenomenon. The fingerprints of the extracted oil fractions obtained by GCMS chromatography at various pressures and temperatures exhibited a variety of shapes. A correlation was obtained between liquid oil recovery and sums of selective specific single carbon number groups. Lighter hydrocarbons of C7-C10 group were representative at 20 MPa, intermediate hydrocarbons of C15-C19 group at 40 MPa, and heavier hydrocarbons of C23-C31 group at 60 MPa.

Design and Analysis of High Pressure Extractor with Supercritical Fluid

Design and Analysis of High Pressure Extractor with Supercritical Fluid

A reliable model to predict thermal conductivity of unsaturated weathered granite soils

The aim of this study is to present a new empirical model to predict thermal conductivity, based on experimental databases that might be particularly applicable to unsaturated weathered granite soils. To establish the experimental databases, a number of thermal conductivity tests were conducted using a new probe system combined with a volumetric pressure extractor. Thereby, 162 data were collected and applied to the prediction model. The prediction model has two empirical coefficients that determine the shape of a graph, and it is not easy to determine these coefficients unless experiments are conducted. Thus, in this paper, we propose using an artificial neural network model to obtain these empirical coefficients without experiments, given only information on the soil properties. Moreover, to evaluate the applicability of the trained network model, it was tested for data sets that had not been introduced during the training stage. According to the verification results, the trained network model presents reasonable prediction results (R2=0.9046), even for the new testing data. In addition, the model traces the measured data curve with fairly good agreement, depending on a sample's porosity, regional characteristics, and degree of saturation.

The bitumen extraction from Nigerian tar sand using dense carbon dioxide

The need for alternative sources of energy has become even more acute in light of the recognition of the dwindling conventional world oil reserves. The interest in exploring other avenues of complimenting and/or eventually replacing this resource is growing quite rapidly. A ready alternative to conventional crude oil is oil sands which are abundant and vastly unexplored. The huge deposits of tar sand found in SouthWestern Nigeria remain untapped due to concerns about the environmental impact. The consequences of the methods in processing tar sand, ranging from water pollution to emission of greenhouse gases, especially in Canada bring in to sharp focus the urgent need for an alternative means of extracting oil from tar sand. A more effective and less environmentally damaging procedure could be the break through needed to open a new chapter in the exploitation of oil sands. The alternative recovery procedure is supercritical carbon dioxide extraction. Recent supercritical extractions use high temperatures and pressures. The upgrade in this research involves using high pressures and lower temperatures which saves energy and improves the process. The experimental study of the bitumen extraction from Nigerian tar sand by dense CO2 was carried out by high pressure extractor. The samples of tar sand were first heated in an oven at 120 °C to melt. A 50 g sample of melted tar sand with addition of 3 g of ethanol was placed into an extractor and heated to 80 °C to initiate the experiment. Carbon dioxide was injected in to the extractor to create 50 MPa of pressure in static mode for 20 min after which the extract was collected. In the presence of ethanol, the extract had a lighter colour than the usual black. Nigerian tar sand is known to be composed of 84 % sand, 17 % bitumen, 4 % water and 2 % mineral clay. Using this data, an extract of 19.47 % was calculated which makes the recovery achieved very encouraging. The experiment shows that recovery of bitumen from tar sand is possible under relatively low temperatures and can be possibly economically profitable.

Using Two Pedotransfer Functions to Estimate Soil Moisture Retention Curves From One Experimental Site of South Moravia

The soil moisture retention curves (SMRCs) were measured in laboratory conditions. The sand table and pressure extractor method were used to obtain a 9-point SMRCs for undisturbed soil samples taken from 20 cm depth. The data points of the individual retention curves were parameterized using the RETC computer program. For the same soil, the SMRCs were estimated by two models of pedotransfer functions (PTFs). In the first part of the study the Rosetta program with the model of artificial neural network (Schaap et al., 1998) was used. The PTFs derived by Wösten et al. (1998) were used in the second part of the study. The reliability of selected PTFs models were tested on local soils from one site of the South Moravia. The quality of estimated retention curves was evaluated using the coefficient for correlation R between the measured and the estimated soil water content at several pF values and the root mean squared error RMSE. Of the two models of PTFs, which have been tested in the study, Wösten’s model showed better agreement with the measured retention curves (RMSESch = 0.0383 (cm3.cm−3), RMSEW = 0.0264 (cm3.cm−3)).

Experimental Evaluation of the Pore-Access Size Distribution of Sands

A simple experimental method is presented for evaluation of the pore-access size distribution of sands and, more generally, of cohesionless granular materials. The water-retention curve of a sand specimen is evaluated using a technique similar to the hanging column method (ASTM 2008) [ASTM D6836: Standard Test Methods for Determination of the Soil Water Chararcteristic Curve for Desorption Using a Hanging Column, Pressure Extractor, Chilled Mirror Hygrometer, and/or Centrifuge, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA, 2008] by application of a step-by-step variation of suction and measure of the corresponding changes in water content. The pore-access size distribution is then evaluated from the water-retention curve using the Young-Laplace law, which links the suction to the pore-access radius. The efficiency of this experimental method is demonstrated by studying the influence of various parameters such as the shape and the size of the grains, the spreading of the grain-size distribution, and also the relative density of the specimen on the pore-size distribution.

전탕장비 및 전탕시간 변화에 의한 평위산(平胃散) 전탕액 비교

ABSTRACT Objectives : Decoction, in Korean Medicine, is a pharmacological method of e xtraction, by boiling, of dissolved chemicals, or herbal prescriptions, which may include stems, ro ots, bark and rhizomes. Decoctions differ from most teas, infusions, in that they are usually boiled. This study was performed to compare the difference of water decoctions extracted by different decoction extractor and extraction time and to analyze the reason of decoctions extracted by each decoction extractor have different taste.Methods : With water decoction samples by Pressure extractor, Non-pressure extractor and Ultrasonic waves merge extractor for 1 hr, 2 hr and 3 hr were investigated the y ield and the concentration of hesperidin and glycyrrhizin by HPLC/DAD system in Pyungwi-san decoction.Results : The samples of each extractor were gradually increased the yield and the concentration of hesperidin and glycyrrhizin. The HPLC pattern of samples is similar. The y ield and the concentration of hesperidin and glycyrrhizin of Ultrasonic waves merge extractor was most highe st of the three. The rate of increase of the yield and the hesperidin concentration of between 1 hr and 2 hr in Pressure extractor was the most highest of the three. But the concentration of glycyrrhizin in Pressure ex tractor was relatively similar to Non-pressure extractor.Conclusions : The yield and the concentration of reference compounds in Pyungwi-san water decoction was influenced by extracting method and extracting time. For scient ific movement and standardization of extracting medicinal herbs method need to study of extractor validation an d to study in vitro and in vivo.Key words : Decoction; Pyungwi-san; hesperidin; glycyrrhizin; extractor; extraction time

Water Characteristic Curves of Recycled Materials

Abstract Water characteristic curves (WCCs) of recycled materials are not well researched. In this study, the WCCs of three specimens from recycled concrete aggregate, three specimens from reclaimed asphalt pavement, and one specimen from spent copper slag are studied. The objective of this study is to obtain WCCs of the recycled materials by using the Tempe cell pressure extractor for standard soil-water characteristic curve determination. Properties of drying WCC of the recycled materials were determined by using a best fit WCC equation. The results showed air-entry value of the recycled materials with high gravel content that occurred at low matric suction below 1.0 kPa and a steep WCC. The results from the WCC and saturated coefficient of permeability tests were incorporated into a statistical model to indirectly predict the permeability function of the recycled materials. The permeability functions of the recycled materials are also presented.

Retention curves of soil from the liz experimental catchment obtained by three methods

The retention curves were measured in the soil from the Liz experimental catchment (Šumava). The sand table and pressure extractor methods were used to obtain a 13-point retention curve for undisturbed soil samples taken from 6 depths. The data points of the individual retention curves were fitted in with the analytical expression of and the reference retention curves were calculated for each depth by scaling. For the same soil, the retention curves were estimated by the artificial neural network method by and the use of the empirical Pedotransfer function. The numerical experiment, which represented the infiltration and redistribution processes, was conducted using of all three sets of retention curves. Simulated water storages and pressure fields obtained using two sets of estimated parameters produced similar results, however they did not approximate well the modelling results obtained with the use of the measured reference parameter set. Of the two sets of pedotransfer functions (PTFs), which have been tested in this study, the empirical PTF of showed a slightly better agreement with the measured retention curves. The results give a guideline for the application of the retention curves estimation by the pedotransfer function for the soil from the Liz catchment.

장염비브리오 항균활성을 위한 탱자와 매실의 추출조건 최적화

비브리오식중독의 피해를 저감시키는 기능성 식품소재를 개발하기 위하여, 예비실험에서 V. parahaemolyticus균에 항균활성이 우수한 것으로 밝혀진 탱자와 매실의 최적 추출조건을 조사하였다. 먼저, 열수로 추출한 실험에서 탱자의 최적 조건은 <TEX>$80{\sim}100^{\circ}C$</TEX>에서 30분간, 매실의 경우 <TEX>$100^{\circ}C$</TEX>에서 30분간 가열 추출한 시험액의 저지환이 각각 14.8 및 16.6 mm로써, 최대의 항균활성을 나타내었다. 또한 NaOH, <TEX>$K_2CO_3$</TEX> 및 <TEX>$NaHCO_3$</TEX>의 알칼리 식품첨가물을 첨가하여 추출한 실험에서, NaOH를 첨가한 경우 탱자의 항균활성은 증진되지 않았으나 매실의 항균활성은 다소 증진되었으며, NaOH 이외 알칼리들은 공시 식물체들의 항균활성을 감소시켰다. NaOH의 첨가농도를 단계적으로 달리하고 80, 100 및 <TEX>$120^{\circ}C$</TEX>에서 추출한 결과, 탱자의 경우 앞서의 열수추출 결과와 별다른 차이가 없었으나, 매실은 NaOH를 0.05N 농도로 첨가하고 <TEX>$120^{\circ}C$</TEX> 에서 추출한 조건에서 저지환 직경 19.9 mm의 최대 항균활성을 나타내었다. 탱자와 매실을 주정으로 진탕추출하고 주정을 제거하여 주정추출물을 얻었다. 이 추출물에 NaOH를 단계적으로 첨가하고 <TEX>$100^{\circ}C$</TEX>에서 30분간 물로 재추출한 결과, 주정추출물의 항균활성은 전반적으로 물추출한 결과보다 낮고 NaOH의 첨가량이 많을수록 활성의 감소를 나내었다. 따라서 본 실험에서, 탱자의 최적추출조건은 <TEX>$80{\sim}100^{\circ}C$</TEX>의 열수로 30분간, 매실은 NaOH를 0.05N 농도로 첨가한 <TEX>$120^{\circ}C$</TEX>의 열수로 30분간 추출하는 것이 가장 효율적이라는 결론을 얻었다. The present investigation was carried out particularly to optimize the extraction process of Poncirus trifoliata and Prunus mume to develop a functional foodstuff having antibacterial activity against Vibrio parahaemolyticus. The extracts were prepared from the fruits under various conditions, and then optimum extraction conditions were decided in case maximal antibacterial activity was obtained. In extraction process by using hot water, the best antibacterial activity of Poncirus trifoliata was achieved at <TEX>$80{\sim}100^{\circ}C$</TEX> for 30 min, while that of Prunus mume was achieved at <TEX>$100^{\circ}C$</TEX> for 30 min, as showing 14.8 and 16.6 mm of inhibition diameter, respectively. The extraction process with addition of NaOH increased the activity of Prunus mume, but addition of <TEX>$K_2CO_3$</TEX> and <TEX>$NaHCO_3$</TEX> drastically decreased the activity. In the processes at high temperature up to <TEX>$120^{\circ}C$</TEX> by using pressure extractor and with various concentrations of NaOH, the maximum activity was observed in the extract of Prunus mume at <TEX>$120^{\circ}C$</TEX> for 30 min with 0.05 N NaOH. The fermented ethanol extract of the fruits showed less activity than those of the extracts with water and NaOH solution.

A Small‐Scale Matric Potential Sensor Based on Time Domain Reflectometry

Measurements of soil matric potential (ψ) are needed in many soil science applications. In the present study, a small matric potential sensor having a length of 30 mm and a diameter of 9.6 mm was developed. The sensor consists of two coils made of lacquer‐coated copper wires embedded in gypsum. The dielectric constant of the gypsum (Kgypsum) was measured with time domain reflectometry (TDR). The gypsum probes were tested in a sandy loam soil using a pressure extractor to obtain the relationship between Kgypsum and ψ, allowing inference of the soil ψ in equilibrium with the sensor. It was shown that the gypsum probe could give ψ estimates with a root mean square error (RMSE) of around 50 kPa in the range of −20 to −1500 kPa. Most of the sensitivity of the sensor was in the −50‐ to −1000‐kPa range.

Hydraulic Properties of Soil-Straw Mixtures

Crop residue management at the soil surface controls C sequestration and soil erosion. The size and distribution of crop residues incorporated into the topsoil affect soil physical properties. The objective of this work was to analyze the immediate effect of straw incorporation on the hydraulic properties of soil. Laboratory experiments were performed to determine the retention and the hydraulic conductivity curves of soil and wheat (Triticum aestivum L.) straw mixtures. The samples consisted of 1-cm straw pieces mixed with loamy soil aggregates of 2 to 3 mm in diameter. Volumetric straw contents were 0, 0.1, 0.2, and 0.3 cm3 cm−3 Suction table and pressure extractor methods were used to measure the water retention curve. Hydraulic conductivity curves were obtained using Wind's evaporation method. At a constant water pressure head, gravimetric water content increased with increasing straw content. The relationship between water pressure and volumetric water content did not differ significantly between the treatments. An additive model based on the sum of the water retention of straw and soil measured separately gave a good estimation of the water retention measured in the mixture. Hydraulic conductivity decreased with increasing straw content for the same water pressure head. Tomographic images showed that mixing straw into the soil created new pores in the samples. Results from simulations of straw decomposition indicated that (i) the uptake of water by straw has to be taken into account when calculating how much water should be added gravimetrically in an incubation experiment and (ii) changes in hydraulic conductivity due to the presence of straw can have an impact on water and C dynamics.

Hydraulic Properties of Soil–Straw Mixtures

Crop residue management at the soil surface controls C sequestration and soil erosion. The size and distribution of crop residues incorporated into the topsoil affect soil physical properties. The objective of this work was to analyze the immediate effect of straw incorporation on the hydraulic properties of soil. Laboratory experiments were performed to determine the retention and the hydraulic conductivity curves of soil and wheat (Triticum aestivum L.) straw mixtures. The samples consisted of 1‐cm straw pieces mixed with loamy soil aggregates of 2 to 3 mm in diameter. Volumetric straw contents were 0, 0.1, 0.2, and 0.3 cm3 cm−3 Suction table and pressure extractor methods were used to measure the water retention curve. Hydraulic conductivity curves were obtained using Wind's evaporation method. At a constant water pressure head, gravimetric water content increased with increasing straw content. The relationship between water pressure and volumetric water content did not differ significantly between the treatments. An additive model based on the sum of the water retention of straw and soil measured separately gave a good estimation of the water retention measured in the mixture. Hydraulic conductivity decreased with increasing straw content for the same water pressure head. Tomographic images showed that mixing straw into the soil created new pores in the samples. Results from simulations of straw decomposition indicated that (i) the uptake of water by straw has to be taken into account when calculating how much water should be added gravimetrically in an incubation experiment and (ii) changes in hydraulic conductivity due to the presence of straw can have an impact on water and C dynamics.

A Technique for Producing Soil Water Retention Curves

SYNOPSIS Water retention curves compiled for specific soil types are an essential management and research tool in evaluating plant stress. The method of producing water retention curves by means of the 1500 kPa pressure extractor is described.

EXPERIENCES WITH THE NEGATIVE PRESSURE EXTRACTOR.

EXPERIENCES WITH THE NEGATIVE PRESSURE EXTRACTOR.