Extraction Behavior Research Articles

Oscillatory extraction behaviour suggests functional attributes of crows' hooked-stick tools.

New Caledonian crows are the only nonhuman animals known to craft hooked-sticks for use in foraging. Since their first description over 25years ago, researchers have been unable to provide a detailed account of how these complex tools function in natural probe sites. Using close-up video footage, we document how a New Caledonian crow operated a hooked-stick to extract a large tree weta from a chamber in a tree trunk. The extraction technique had two distinct, separate components: (1) simultaneous oscillating head rotation and reciprocating bill action, and (2) measured pulling with the tool. Analysis of this first detailed field observation of hooked-stick use suggests a link between hooked-stick tool characteristics, functionality and skilled manipulation in natural prey extraction by these technological birds. Our findings also provide a rare, if not novel, example of tool-associated oscillatory manipulation in nonhuman animals.

Solubilities and metal extraction behaviors for calix[4]arene acetic-acid derivatives in various organic solvents

Solubilities and metal extraction behaviors for calix[4]arene acetic-acid derivatives in various organic solvents

Ionic liquid as hydrogen bond acceptor in the extraction of nutritional natural products

In-depth studies of the extraction mechanism using deep eutectic solvents (DES), especially extraction through the formation of a deep eutectic system (DESys), revealed commonalities between the DES- and ionic liquids (IL)-based extraction systems. New applications of ILs and DES for extraction of nutritional natural products were presented. In this study, the extraction behavior of choline chloride (ChCl) and 1-(2-hydroxyethyl)-3-methylimidazolium chloride ([HMIm][Cl]) in DES and IL, respectively, in mechanochemical extraction of target compounds from Moringa oleifera leaves was systematically studied. The results suggested that both extraction methods were based on the formation of a DESys, either a normal DESys or an IL DESys. Considering the DESys-based one-step extraction improves the extraction efficiency and reduces the preparation time, the same idea can be used in IL for performance improvement. By formation of a new IL deep eutectic system based on hydrogen bond interaction in extraction, similar improvement was obtained.

Deuterated Malonamide Synthesis for Fundamental Research on Solvent Extraction Systems

ABSTRACT Malonamide derivatives, which are the most extensively investigated extractants for solvent extraction of lanthanides, actinides, and platinum group metal ions, were deuterated by using Pd/C and Rh/C catalysts in a D2O/2-propanol mixture. This method replaces 1H atoms in the malonamides with 2H atoms at a controllable deuteration rate. The maximum rate reached about 75%, determined by nuclear magnetic resonance and electrospray ionization – mass spectrometry. The extraction behavior of metal ions by the malonamides was unchanged by the deuteration. Deuterated malonamides are a powerful tool for fundamental research on solvent extraction systems and for structural analysis of organic phases. The large difference in the cross section of coherent neutron scattering between 1H and 2H leads to a large difference in neutron scattering length density of malonamide derivatives before and after the deuteration. Therefore, using deuterated malonamides in small-angle neutron scattering and neutron reflectivity studies may help to reveal the microscopic structure of the specific solute species in the bulk organic phase and at the liquid–liquid interface, respectively. In this paper, we report the advantage of the deuterated malonamides for a contrast-matching method in the SANS experiment. This deuteration method could be generalized and extended to a wide variety of extractant molecules.

Bio-coloration and ultraviolet protection finishing of tussah silk using chestnut leaf extract and its thermodynamic study

This study investigates the dyeing effects of chestnut leaf extract on tussah silk and aspires to create bio-colored and ultraviolet-resistant textiles. The results proved that post-mordanting with aluminum potassium sulfate and ferrous sulfate yielded better results than direct dyeing, the color strength value with ferrous sulfate mordant reached 10.9, and the color fastness of tussah silk with post-mordanting was rated above 4. Furthermore, the ultraviolet protection factor values reached 17, 39, 45, and 53 with control, direct dyeing, and post-mordanting with aluminum potassium sulfate and ferrous sulfate, respectively, revealing that the chestnut leaf extract could be a potential ultraviolet protection agent to increase the ultraviolet protection performance on tussah silk. In addition, the adsorption process and thermodynamic characteristics of chestnut leaf extract on tussah silk were examined. The results suggested that the Langmuir isotherm model adequately described the thermodynamic behavior of chestnut leaf extract on tussah silk. The positive enthalpy change indicated that the adsorption process was an endothermic process.

Preparation of a Flow Single-drop Extraction System for Educational Use Capable of the Simultaneous and Continuous Observation of Extraction Behavior and Absorbance Change

A portable flow single-drop extraction system was prepared as an educational tool for facilitating the connection between actual extraction behavior and theory. In this system, an aqueous dye solution is circulated through a ring-shaped extraction cell equipped with a droplet introduction unit and a flow cell for absorbance detection. The dye is extracted into a droplet in the extraction cell. This system enables simultaneous and continuous observation of the image of the droplet in the extraction cell and changes in absorption spectrum or absorbance over time on the same screen by using a USB camera. It was suggested that the material balance in the extraction can be calculated from the decrease in absorbance of the circulating dye solution and the absorbance of the droplet after the extraction.

Data analysis of the corrosion protection behavior of ginger, tea tree and grapefruit essential oil extracts on low carbon steel in H2SO4 solution

Application of corrosion inhibitors are the most versatile corrosion prevention methods of carbon steels in corrosive environments. Research on non-toxic chemical compounds are ongoing and results from previous study have proven the effectiveness of the compounds. Data on corrosion inhibition of ginger (GG), tea tree (TR) and grapefruit (GF) oil extracts on low carbon steel in 0.5 M H2SO4 are presented. The extracts performed effectively with optimal values of 99.56 %, 98.17 % and 98.32 % at 2.5 % GG, 3.5 % TR and 3 % GF concentrations. Corresponding corrosion rate values are 0.28 mm/y, 1.16 mm/y and 1.49 mm/y. Corrosion rate at 0 % extract concentration is 63.33 mm/y. Performance of TR extract significantly varies with time and concentration with statistical value of 48.21 % and 23.02 %. GG and GF concentration where the only statistically relevant factors for GG and GF performance with statistical values of 68.42 % and 73.20 %. Standard deviation data for GG extracts varied minimally from mean values compared to TR and GF extracts. Results shows 92 %, 18 % and 63 % of GG, TR and GF extracts inhibition data are above 95 % inhibition value at margin of error of 6.99 %, 10 % and 12.19 %.

Understanding the correlation between extraction and luminescence behavior of Eu(iii) in a biphasic system in the presence of Co-extracting metal ions

The presence of co-extracting metal ions significantly impacts the extraction as well as the luminescence behavior of Eu(iii) in a biphasic extraction system. Correlating both behaviors unveils some of the fundamental facts of Eu(iii) coordination.

Computer Vision-Based Assessment of Autistic Children: Analyzing Interactions, Emotions, Human Pose, and Life Skills

In this paper, the proposed work tests the computer vision application to perform the skill and emotion assessment of children with Autism Spectrum Disorder (ASD) by extracting various bio-behaviors, human activities, child-therapist interactions, and joint pose estimations from the video-recorded interactive single-or two-person play-based intervention sessions. A comprehensive data set of 300 videos are amassed from ASD children engaged in social interaction and developed three novel deep learning-based computer vision models which are explained as follows: 1) activity comprehension to analyze child-play partner interactions (Activity Comprehension model); 2) an automatic joint attention recognition framework using pose, and 3) emotion and facial expression recognition. We tested models on children’s real-world unseen 68 videos captured from the clinic and public datasets. The activity comprehension model has an overall accuracy of 72.32%, the joint attention models have an accuracy of 97% for following eye gaze and 93.4% for hand pointing and the facial expression recognition model has an overall accuracy of 95.1%. The proposed models could extract activities and behaviors of interest from free-play and intervention session videos, empowering clinicians with data useful in diagnosis, assessment, treatment formulation, and monitoring of ASD children with limited supervision.

Extraction of Metal Ions Using a Calix[4]arene Carboxylic Acid Derivative in Aromatic Ethers

If calixarenes can be dissolved in a relatively safe non-halogen solvent, they can be used in a liquid-liquid extraction process suitable for mass processing. In the present study, extraction behavior of metal ions using a calix[4]arene carboxylic acid derivative (tOct[4]CH2COOH) dissolved in aromatic ethers was investigated. The solubility of tOct[4]CH2COOH in aromatic ethers decreases with increase of the length of aliphatic side chain of the ethers. The solubility of tOct[4]CH2COOH in 1-butoxybenzene (BB) was 28.0 mmol/L, which is smaller than that in chloroform but is higher than those in hexane and toluene. Divalent metal ions Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Pb(II) were extracted using tOct[4]CH2COOH in BB through proton exchange reaction at similar pH range in toluene, which is higher than that in chloroform. The extraction reaction of Cu(II) using tOct[4]CH2COOH in BB was determined by slope analysis and loading test. The stoichiometry between tOct[4]CH2COOH and Cu(II) was 2:1.

Extraction of Au(III) Using Aromatic Ketones in Acidic Chloride Media

Recently, the extraction of Au(III) using the series of aliphatic ketones in hydrochloric acid media has been investigated in detail. The present study describes the extraction behaviors of Au(III) using a series of aromatic ketones, which has never been reported. Aromatic ketones with shorter alkyl side chains showed higher extractability. The rapid extraction and the extraction capacity using aromatic ketones were comparable to the industrial extractant dibutyl carbitol (DBC). Aromatic ketones, except acetophenone, are less soluble in water than DBC. The flash points of aromatic ketones are satisfactorily high for industrial operation, but their specific gravities comparable to that of water are unwelcome. Butyrophenone selectively extracted Au(III) from many other metals, except for high extraction of Fe(III) and Ga(III) at high concentrations. Au(III) extracted using butyrophenone recovered quantitatively as metallic gold by reduction using oxalic acid.

A COMPARATIVE STUDY ON THE OIL RECOVERY PERFORMANCE OF THE CO2 AND N2 HUFF-N-PUFF PROCESSES IN LOW PERMEABILITY CORES

The gas huff-n-puff process has been widely employed in low permeability reservoir development practices. At present, the understanding of synergistic effects of different injection fluids and rock permeability is still limited and is worthy of in-depth investigation. Therefore, laboratory studies on oil recovery performance of supercritical CO<sub>2</sub> (scCO<sub>2</sub>) and N<sub>2</sub> huff-n-puff processes in ultra-low (< 0.5 mD), extra-low (0.5-1 mD), and average-low permeability (1-10 mD) core samples were systematically investigated. More effective cycles could be achieved in the CO<sub>2</sub> huff-n-puff process than in the N<sub>2</sub> process. The CO<sub>2</sub> huff-n-puff operation could produce 29.9% oil in the ultralow permeability core, which is obviously higher than 20.2% for N<sub>2</sub>. With increasing core permeability, the oil recovery ratio for both the scCO<sub>2</sub> and N<sub>2</sub> huff-n-puff processes increases as well. Laboratory results show oil recovery ratios of 33.1% and 47.3% for the scCO<sub>2</sub> process in 0.5 mD and 10 mD cores and 36.3% and 49.1% for the N<sub>2</sub> process in 0.5 mD and 9.5 mD cores, respectively. Although the oil recovery rates for the N<sub>2</sub> and CO<sub>2</sub> huff-n-puff processes are close in the 0.5 mD and 10 mD cores, the effective oil extraction pressure for the scCO<sub>2</sub> puff process is found to be 5~10 MPa, which is much higher than 0~2 MPa for the N<sub>2</sub> puff process. The study's findings can help provide a better understanding of the oil extraction behaviors in the huff-n-puff process with different injection fluids as well as in different low permeability cores.

Extraction Behavior of Lanthanoids(III) with Bis(2-ethylhexyl)phosphoric Acid into Ionic Liquid 1-Butyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)imide

The extraction behavior of 14 trivalent lanthanoids (Lns) with bis(2-ethylhexyl)phosphoric acid (HR) into a typical hydrophobic ionic liquid (IL), 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, was investigated. The extraction is so slow that a shaking time of more than 36 hours is needed to reach extraction equilibrium. Compared to the extraction system using toluene as an extraction solvent, the IL extraction system has higher extraction ability for all Lns and higher selectivity for some couples of Lns (e.g., Ce/La and Tb/Gd). The dependences of the distribution ratio on the aqueous pH and the HR concentration suggest that the main extracted species are neutral LnR3(HR)3 for light and middle Lns and Tb, but anionic LnR4(HR)2– and LnR5(HR)2– for heavy Lns (except for Tb). The addition of 1-octanol as a phase stabilizer decreases the extractability of Lns, which can be explained in terms of interaction between 1-octanol and HR dimer.

Extraction Properties of Trivalent Rare Earth Ions from Nitric Acid Using a Triamide–Amine Extractant

The extraction of trivalent rare earth ions (RE3+) from HNO3 solution using a triamide amine, tris(N,N-di-2-ethylhexyl-ethylamide)amine (DEHTAA), was conducted, and the extraction mechanism was estimated from extraction behavior of HNO3 and RE3+. A DEHTAA molecule dominantly formed a DEHTAA⸱HNO3 at 1.0 M HNO3 and a DEHTAA⸱(HNO3)2 at 6.0 M HNO3 in the acid-equilibrated organic phase. This would provide the unique dependence of E% for the light RE3+ on the HNO3 concentration, in which the E% value had a minimum and maximum at ~0.5 M and ~2 M HNO3, respectively. The results of the slope analyses for the distribution ratios for RE3+ suggested that the dominant RE3+ complex was RE(NO3)3DEHTAA(DEHTAA⸱HNO3) at 1.0 M HNO3. The E% for RE3+ decreased from La3+ to Lu3+ at 1.0 M HNO3; however, those increased from La3+ to Nd3+ at 0.25 M HNO3 and from La3+ to Sm3+ at 6.0 M HNO3.

Royalty Tax Rate and the Under-reporting Dilemma in Tanzania’s Mining Sector

The paper investigates whether an increase in royalty tax rates reduces or eliminates under-reporting by firms in Tanzania’s mining sector. It uses a theoretical approach to dynamic optimisation techniques. The findings suggest that an increase in the royalty tax rate does not necessarily lower the possibility of under-reporting. Our approach is to look at the royalty tax that is levied based on the gross value. Its impact on the firm’s extraction behaviour depends mostly on the prices of minerals. More importantly, the price movements counteract the impact of a given royalty tax. We also suggest that when a country wishes to reduce or eliminate under-reporting practices, it should strengthen the regulatory body that oversees the operations of firms in the sector.

Experimental and theoretical studies on the extraction behavior of Cf(iii) by NTAamide(C8) ligand and the separation of Cf(iii)/Cm(iii).

In this work we studied the extraction behaviors of Cf(iii) by NTAamide (N,N,N',N',N'',N''-hexaocactyl-nitrilotriacetamide, C8) in nitric acid medium. Influencing factors such as contact time, concentration of NTAamide(C8), HNO3 and NO3 - as well as temperature were considered. The slope analysis showed that Cf(iii) should be coordinated in the form of neutral molecules, and the extraction complex should be Cf(NO3)3·2L (L = NTAamide(C8)), which can achieve better extraction effect under the low acidity condition. When the concentration of HNO3 was 0.1 mol L-1, the separation factor (SFCf/Cm) was 3.34. The extractant has application prospect to differentiate the trivalent Cf(iii) and Cm(iii) when the concentration of nitric acid is low. On the other hand, density functional theory (DFT) calculations were conducted to explore the coordination mechanism of NTAamide(C8) ligands with Cf/Cm cations. The NTAamide(C8) complexes of Cf(iii)/Cm(iii) have similar geometric structures, and An(iii) is more likely to form a complex with 1 : 2 stoichiometry (metal ion/ligands). In addition, bonding property and thermodynamics analyses showed that NTAamide(C8) ligands had stronger coordination ability with Cf(iii) over Cm(iii). Our work provides meaningful information with regard to the in-group separation of An(iii) in practical systems.

Yttrium separation by phosphorylcarboxylic acid and the underlying tetrad effect along lanthanide unveiled from different microscopic interactions

Due to similar physical and chemical properties, separating and purifying rare earth elements is challenging. Considering the environmental issue, the design and synthesis of efficient and green extractants are significant for this purpose. To this end, the underlying complexation between rare earth and the extractant should be clarified, and the long-historically existing tetrad effect along with the lanthanide family from La to Lu due to the different 4f orbital occupations should be figured out. Thus, within this study, taking our newly experimentally synthesized extractant, phosphorylcarboxylic acid, as an example and utilizing accurate quantum mechanical calculation, we comprehensively investigated the complexation behavior between rare earth and the extractant via the quantum theory of atoms in molecules (QTAIM), Mayer bond order (MBO), molecular orbital (MO) energy level, natural bond orbital (NBO), charge decomposition analysis (CDA), electron localization function (ELF) and extended transition state-natural orbitals for chemical valence (ETS-NOCV). It has been found that yttrium can be separated from the lanthanide series by the phosphorylcarboxylic acid, attributed to the poor ability of Y3+ to accept electrons and the weak orbital interactions compared to other rare earth cations. This paper also reveals the tetrad effect caused by the different occupations of 4f orbital electrons, providing a theoretical approach to comprehending the diverse extraction behaviors in the rare earth extraction process.

Extraction of Se(iv) and Se(vi) from aqueous HCl solution by using a diamide-containing tertiary amine.

Here, we investigated the mechanism underlying the extraction of Se(iv) and Se(vi) from aqueous HCl solutions by N-2-ethylhexyl-bis(N-di-2-ethylhexyl-ethylamide)amine (EHBAA). In addition to examining extraction behavior, we also elucidated structural properties of the dominant Se species in solution. Two types of aqueous HCl solutions were prepared by dissolving a SeIV oxide or a SeVI salt. X-ray absorption near edge structure analyses revealed that Se(vi) was reduced to Se(iv) in 8 M HCl. Using 0.5 M EHBAA, ∼50% of Se(vi) was extracted from 0.5 M HCl. In contrast, Se(iv) was hardly extracted from 0.5 to 5 M HCl; however, at molar concentrations above 5 M, the extraction efficiency of Se(iv) increased drastically, reaching ∼85%. Slope analyses for the distribution ratios of Se(iv) in 8 M HCl and Se(vi) in 0.5 M HCl showed that apparent stoichiometries of Se(iv) or Se(vi) to EHBAA were 1 : 1 and 1 : 2, respectively. Extended X-ray absorption fine structure measurements revealed that the inner-sphere of the Se(iv) and Se(vi) complexes extracted with EHBAA was [SeOCl2] and [SeO4]2-, respectively. Together, these results indicate that Se(iv) is extracted from 8 M HCl with EHBAA via a solvation-type reaction, whereas Se(vi) is extracted from 0.5 M HCl via an anion-exchange-type reaction.

Study of irradiation decomposition products of PUREX solvents on zirconium metal retention behavior

The metal retention behaviors of several simulated radiolysis products on zirconium metal were investigated, and it was found that acid phosphate radiolysis product HDEHP has the greatest effect. The effects of extraction nitric acid concentration, simulated radiolysis product concentration, metal concentration, and temperature on the zirconium metal retention behavior were also investigated. The results showed that zirconium metal forms complexes with HDEHP resulting in retention in the organic phase. Nitric acid concentration and metal concentration change the morphology of the metal thus affecting the extraction and metal retention behavior. The temperature has almost no effect on metal retention.

Extraction Behavior of Some Elements from Leaching Solution of Simulated Nuclear Fuel

The crush-leach process was investigated as a method to treat GEN IV simulated ceramic-coated reactor fuel. Simulated ceramic-coated fuel was prepared using fine carbon as a coating and surrogate elements for fuel, the method retained the bulk of the carbon components in elemental form, which is favorable for achieving waste reduction goals. Simulated ceramic-coated fuel was crushed and nitric acid was added to the fines as slurry that led to rapid and effective leaching of the heavy metal. The leaching process of simulated crushed ceramic-coated fuel and extraction behavior of the separated leaching solution was tested at the laboratory scale. Results showed that carbon used in the preparation of stimulated fuel was difficult to be separated by filtered, indicating the need to carefully control particle size and/or use alternative solid-liquid separation methods. Foams or emulsions was not observed during the solvent extraction step, which indicated that measurement of the distribution ratios for actinides elements were slightly larger than predicted by previous models. This increase may be due to small concentrations of organics; however the experimental results are not conclusive. Although the results do not strongly indicate effects by a contaminating organic agent, the organic species may exist in small concentrations. Such an organic species could affect the extraction behavior of the solvent if it accumulates over time.