Stripping Extraction Research Articles

Lorentz dissociation of hydrogen ions in a cyclotron

Stripping extraction of hydrogen molecular ions has gained interest in the cyclotron industry due to its high extraction efficiency. However, the magnetic field could result in undesired Lorentz dissociation of the hydrogen anion/molecular ions during acceleration. Studies of dissociation under electric fields comparable to that of a Lorentz-transformed magnetic field in a typical cyclotron (a few MV/cm) are sparse. Hence, in order to fill in the missing yet crucial information when designing a cyclotron, this work compiles and summarizes the study of Lorentz dissociation of H-, H+ 2 and H+ 3 for stripping extraction in a cyclotron.

Purification and Characterization of High Purity Nano Zirconia by Liquid-Liquid Extraction Using D2EHPA/p-Xylenes

In this paper, Zr(IV) nitrate solution decomposed from Viet Nam zircon concentrate was the source of zirconium extraction by liquid-liquid extraction (L.L.E). The FT-IR and UV-Vis spectra confirmed the extraction of Zr(IV) by D2EHPA/p-xylenes. There were four stages for the purification of impurities from the Zr matrix. First, the extraction of elements in 3.0 M HNO3 by 50% D2EHPA/p-xylenes was conducted. Second, two scrubbing cycles of impurities using 6.0 M HNO3, 76.5% of the total amount of Zr(IV) were retained in the organic phase, and 23.5% remained in the aqueous phase. Third, the stripping of a macro amount of zirconium from loaded D2EHPA has been effectively carried out using 1.5 M H2SO4 with a stripping efficiency of 99.6%. Fourth, concentrated ammonia was added to the solution Zr(IV) after stripping extraction to form precipitate for calcination at 550 °C for the final products. The refined products were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), EDS, XRF, and diffuse reflectance spectroscopy. The ZrO2 has high purity, is nanospherical, and has a uniform sphere-like morphology with small grain size of less than 30 nm and a bandgap value of about 3.30 eV.

Effects of process factors on performances of liquid membrane-based transfer of indole-3-acetic acid

The paper has aimed at studying the transfer of indole 3-acetic acid (IAA) from a feed aqueous solution to a stripping aqueous solution of NaOH using a chloroform bulk liquid membrane and trioctylamine (TOA) as a ligand (L). Initial molar concentrations of IAA in the feed phase, cIAA,F0 (10–4–10–3 kmol/m3), of TOA in the membrane phase, cL,M0 (10–2 and 10–1 kmol/m3), and of NaOH in the stripping phase, cNaOH,S0 (10–2 and 1 kmol/m3), were selected as process factors. Their effects on the final values of IAA concentration in the feed phase (cIAA,Ff) and stripping solution (cIAA,Sf), extraction efficiency (EF), distribution coefficient (KD), and recovery efficiency (ER) were quantified using multiple regression equations. Regression coefficients were determined from experimental data, i.e., cIAA,Ff,ex = 0.02–1 × 10–4 kmol/m3, cIAA,Sf,ex = 0.22–2.58 × 10–3 kmol/m3, EF,ex = 90.0–97.9%, KD,ex = 9.0–46.6, and ER,ex = 66.5–94.2%. It was found that cIAA,F0 had the most significant positive effect on cIAA,Ff and cIAA,Sf, whereas cNaOH,S0 had a major positive effect on EF, KD, and ER. A deterministic model based on mass transfer of IAA was developed and its parameters, i.e., mass transfer coefficient of IAA-L complex in the liquid membrane (0.82–11.5 × 10–7 m/s) and extraction constant (1033.9–1779.7 m3/kmol), were regressed from experimental data. The effect of cL,M0 on both parameters was significant.

Extraction and separation of Pd(II) by N, N'-diethyl-N, N'-dicyclohexylmalonamide in a nitric acid system

This study indicated the extraction and separation of Pd(II) by N, N'-diethyl-N, N' -dicyclohexylmalonamide (DEDCHMA) from the aqueous nitric acid solution. The effects of extraction time, nitric acid concentration, diluent, extraction temperature, and extractant concentration on extraction distribution ratio were investigated. The extraction mechanism and the composition of the complex were further discussed based on FT-IR and slope analysis. Compared with N, N, N', N'-tetraoctyl diglycolamide (TODGA) and N, N, N', N'-tetracyclohexylmalonamide (TCHMA), the DEDCHMA showed higher extraction capacity for Pd(II), which is 46 and 15 times higher than that of TCHMA and TODGA, respectively. The stripping extraction ratio obtained in Pd(II)-loaded organic phase using thiourea or oxalic acid reached 99%. The extraction selectivity to Pd(II) and noble metals such as Ru(III), Rh(III), and some common base metals, such as Al(III), Fe(III), Ni(II), Cu(II), Zn(II), Ca(II), Mg(II), Pb(II), Sr(II), Cr(III) and CO(II), was also investigated. The results demonstrate that DEDCHMA can be used to treat and recover Pd(II) from nitrate-based wastes containing associated precious metals, such as Pd(II), Ru(III), Rh(III), and common base metal, as well as from the spent fuel reprocessing.

Real-Time Compact Environment Representation for UAV Navigation.

Recently, unmanned aerial vehicles (UAVs) have attracted much attention due to their on-demand deployment, high mobility, and low cost. For UAVs navigating in an unknown environment, efficient environment representation is needed due to the storage limitation of the UAVs. Nonetheless, building an accurate and compact environment representation model is highly non-trivial because of the unknown shape of the obstacles and the time-consuming operations such as finding and eliminating the environmental details. To overcome these challenges, a novel vertical strip extraction algorithm is proposed to analyze the probability density function characteristics of the normalized disparity value and segment the obstacles through an adaptive size sliding window. In addition, a plane adjustment algorithm is proposed to represent the obstacle surfaces as polygonal prism profiles while minimizing the redundant obstacle information. By combining these two proposed algorithms, the depth sensor data can be converted into the multi-layer polygonal prism models in real time. Besides, a drone platform equipped with a depth sensor is developed to build the compact environment representation models in the real world. Experimental results demonstrate that the proposed scheme achieves better performance in terms of precision and storage as compared to the baseline.

Using Sesame Seed Oil to Preserve and Preconcentrate Cannabinoids for Paper Spray Mass Spectrometry.

Cannabinoids present a unique set of analytical challenges. An increasing number of states have voted to decriminalize recreational marijuana use, creating a need for new kinds of rapid testing. At the same time, synthetic compounds with activity similar to THC, termed synthetic cannabinoids, have become more prevalent and pose significant health risks. A rapid method capable of detecting both natural and synthetic cannabinoids would be useful in cases of driving under the influence of drugs, where it might not be obvious whether the suspect consumed marijuana, a synthetic cannabinoid, or both. Paper spray mass spectrometry is an ambient ionization technique which allows for the direct ionization of analyte from a biofluid spot on a piece of paper. Natural cannabinoids like THC, however, are labile and rapidly disappear from dried sample spots, making it difficult to detect them at clinically relevant levels. Presented here is a method to concentrate and preserve THC and synthetic cannabinoids in urine and oral fluid on paper for analysis by paper spray mass spectrometry. Sesame seed oil was investigated both as a means of preserving THC and as part of a technique, termed paper strip extraction, wherein urine or oral fluid is flowed through an oil spot on a strip of paper to preconcentrate cannabinoids. This technique preserved THC in dried biofluid samples for at least 27 days at room temperature; paper spray MS/MS analysis of these preserved dried spots was capable of detecting THC and synthetic cannabinoids at low ng/mL concentrations, making it suitable as a rapid screening technique. The technique was adapted to be used with a commercially available autosampler.

Research on 3D measurement model by line structure light vision

For serious radial distortion and high precision measurement, 3D measurement model is studied in the paper. Based on the two-step calibration algorithm, a round initialization window is proposed to calculate the initial value of the camera parameters for nonlinear optimization. In order to solve the problem that the Supersonic Transport Evaluation Group algorithm of light stripe center extraction has a large amount of computation, a method is presented by normalized correlation coefficient (NCC) method and principal component analysis (PCA). Finally, the coordinates of the central stripe could be obtained based on the bilinear interpolation and parabolic fitting. With the parameters of the structured light plane that could be obtained by the coordinates of the central stripe, the height of block gauge is measured by the 3D measurement model. The experiment results showed that the average measurement error is 0.0191 mm, and the strip extraction speed is improved.

Inhaled nitrous oxide can reduce the pain perception in post Caldwell-Luc operation patients\u2013a randomised trial

To assess the efficiency of inhaled nitrous oxide (N2O) for the reduce the perception pain in extraction of iodoform gauze packing strips in post Caldwell-Luc operation patients. This randomized single blind trial included a total of 47 patients, aged between 14–82 years, in which undergoing radical maxillary sinusotomy. Based on the randomization procedure, patients were treated with (experimental) or without (control) inhaled N2O. The visual analogue scale scores (VAS scores) of the pain perception and the headache duration time were comparatively studied. The average VAS score for pain perception was 3.92 in the N2O group and 7.87 in the control group. The average headache duration time was 0.12 hour in the N2O group and 13.09 hours in the control group. Both VAS scores for pain perception during the treatment and the average headache duration time were significantly reduced in the inhaled N2O group (P < 0.01). Reduced pain perception and headache duration time indicated that, the inhaled N2O method might be viable in extraction of iodoform gauze packing strips in post Caldwell-Luc operation patients.

Molecularly imprinted polymer based on magnetic ionic liquid for solid-phase extraction of phenolic acids

ABSTRACTIn this study, 1-allyl-3-octylimidazolium tetrachloroferrate ionic liquid was first synthesized. Molecularly imprinted polymer was prepared by suspension polymerization using 1-allyl-3-octylimidazolium tetrachloroferrate as functional monomer and chlorogenic acid as template molecule. The polymer was characterized by Fourier transformed infrared spectroscopy and scanning electron microscopy. Thermal stability of the polymer was investigated. The solid-phase extraction method based on magnetic molecularly imprinted polymer was developed for gallic acid, protocatechuic acid, caffeic acid, chlorogenic acid, p-coumaric acid, and ferulic acid. The sample pH, the type and volume of stripping solution, sorbent amount, and extraction time were optimized for phenolic acids. The analysis of phenolic acids after extraction was carried out using high-performance liquid chromatography with UV detection. Limit of detection, limit of quantification, linear range, correlation coefficient, and reproducibilities of within-day and between-day for phenolic acids were determined. The residues of phenolic acids in apple samples were successfully detected by the developed method. Recovery of standard spiked apple samples was ≥81 for all the phenolic acids.

Design of a Combined Function Magnet With Individually Adjustable Functions

Design of combined function magnets for accelerators is often limited to minor modifications of the existing components, maintaining the high quality of the main harmonic field component, but restricting the range of operation. We investigate the possibility to achieve a wide range of both steering magnetic flux density and focusing field gradients, by utilizing two individually powered magnet parts. A general design methodology is presented, enabling fully customized design and optimization of magnets for different applications. The design procedure is illustrated via a detailed design of a magnet proposed for application in the stripping extraction system of a multipurpose cyclotron.

Band pattern analysis of mutations in rifampicin resistance strain of Mycobacterium tuberculosis by Line Probe assay in patients from Delhi, India

BackgroundThe GenoType MTBDRplus, a commercial Line Probe Assay (LPA) kit from Hain Lifescience, Germany, is endorsed by India's RNTCP Program for diagnosis of DRTB cases among smear-positive sputum samples. Although the LPA has been studied in several laboratories, there is a wide variation in existing M. tuberculosis strains across the globe, and false results can occur due to the presence of unique genetic mutations in different settings. Aim and objectiveAn attempt was made to carry out band pattern analysis using LPA and also to observe uncommon mutations in MDR strains. Materials and methodsSputum samples were collected from MDR suspects and transported to intermediate reference laboratory (IRL) at New Delhi Tuberculosis Centre in Delhi. Sputum decontamination, DNA extraction, amplification, hybridization, and band pattern analysis of Line Probe assay strips was performed as per manufacturer's instructions. ResultsAmong the 3000 samples with interpretable LPA strips, rifampicin drug resistance with or without isoniazid was observed in 600 samples. The most common mutation detected by LPA in the rpoB gene was Ser516Leu (29.0%). Novel mutations reported in this study include mutation from CAG (Gin) to CAT (His) at codon 517, AGC (Ser)-AGG (Arg) at codon 512, ACA (Thr) to GCA (Ala) at codon 526, TTG (Leu)-CTG (Leu)s at codon 524. ConclusionHigh frequencies of uncommon mutations in rpoB gene by LPA were observed, highlighting possibility of those in-silico detected mutations that may not impart phenotypic resistance further.

A Comprehensive Study of Extraction of L-Lysine with Sec-Octylphenoxy Acetic Acid in Sulfonated Kerosene

Extraction of L-lysine with sec-octylphenoxy acetic acid (CA-12) in sulfonated kerosene was investigated under different pH and CA-12 concentrations, and optimized conditions were determined. Half-saturation fluorometric analysis and atomic force microscopy showed that the electrovalent bond between L-lysine and CA-12 acted as the main force to partition L-lysine into organic phase. Moreover, the mathematically analyzed extraction process indicated that the extractive complex was a 1:2 L-lysine • CA-12 structure. The initial extraction efficiency could reach 78.9 ± 1.2% and the total strip extraction efficiency after three strip extractions could reach 95.7 ± 1.8% by using a dilute KCl solution.

Magnet with Uncoupled Combined Functions

Efficient extraction by ion stripping of a number of ion beams from a multipurpose cyclotron through the same transport line could be achieved with a combined function magnet. Characteristics of a combined magnet used for this purpose are significantly different from those of commonly used combined function magnets. For example, bending and focusing functions must be independently adjustable, beam paths are not centered to the device's axis, only one device is needed per cyclotron, and requirements regarding maximal achievable quadrupole and dipole fields as well as field linearity are not as demanding as for combined function magnets used for other applications. Using two analytical models as well as a simple numerical model, it is shown that two independently powered slanted dipoles, off-centered and arranged symmetrically with respect to the beam area, could efficiently serve as a combined function magnet in the stripping extraction system of a multipurpose cyclotron.

Cyclotrons with fast variable and/or multiple energy extraction

We discuss the principle possibility of stripping extraction in combination with reverse bends in isochronous separate sector cyclotrons (and/or FFAGs). If one uses reverse bends between the sectors (instead of drifts) and places stripper foils at the sector exit edges, the stripped beam has a reduced bending radius and it should be able to leave the cyclotron within the range of the reverse bend - even if the beam is stripped at less than full energy. We are especially interested in $H_2^+$-cyclotrons, which allow to double the charge to mass ratio by stripping. However the principle could be applied to other ions or ionized molecules as well. For the production of proton beams by stripping extraction of an $H_2^+$-beam, we discuss possible designs for three types of machines: First a low-energy cyclotron for the simultaneous production of several beams at multiple energies - for instance 15 MeV, 30 MeV and 70 MeV - thus allowing to have beam on several isotope production targets. In this case it is desired to have a strong energy dependence of the direction of the extracted beam thus allowing to run multiple target stations simultaneously. Second we consider a fast variable energy proton machine for cancer therapy that should allow extraction (of the complete beam) at all energies in the range of about 70 MeV to about 250 MeV into the same beam line. And third, we consider a high intensity high energy machine, where the main design goals are extraction with low losses, low activation of components and high reliability. The price that has to be paid for these advantages is an increase in size and/or in field strength compared to proton machines with standard extraction at the final energy.

Comparison of ATR–FTIR spectra of porcine vaginal and buccal mucosa with ear skin and penetration analysis of drug and vehicle components into pig ear

In the present study, porcine buccal and vaginal mucosae were successfully characterised by ATR–FTIR for the first time and compared to porcine ear skin. By analysing typical bands of the spectra, the structure of proteins and the lipid matrix were elucidated. According to the body site, differences in membrane permeability were detected when analysing the CH2-stretching and -scissoring vibrations. The results indicated a higher permeability for porcine vaginal and buccal tissue compared to skin. Furthermore, the influence of a lecithin-based microemulsion on the barrier properties of the above mentioned tissues was investigated by ATR–FTIR; the results revealed structural changes in all tissues. In addition, the ATR–FTIR technique was employed to semi-quantitatively analyse compounds directly on skin. To this end, tape stripping experiments were performed with a deuterated liposomal drug delivery system containing the model drug flufenamic acid. While the amount of penetrated deuterated liposomes was determined directly on skin samples by ATR–FTIR, the drug amount was analysed by HPLC after extraction of the tape strips since higher sensitivity was achieved in this fashion. Thus, it was possible to monitor the skin penetration of drug and vehicle simultaneously. Interestingly, the results indicated an independent drug penetration after release from the liposomal carrier system.

Analytical Prediction of Ion Stripping Extraction From Isochronous Cyclotrons

Accelerated ion beams are often extracted from a cyclotron by stripping some of ion's electrons at the end of the acceleration process. Stripping extraction system is commonly designed and optimized using computer simulations of beam dynamics at a later stage of a cyclotron project. However, minor changes in the distance between the magnet poles are proven to cause large displacements of the optimal position of high-energy transport line. It is shown that simple analytical formulas give good prediction of the position and direction of beam exit after stripping extraction and are useful tool for preliminary facility layout planning.

Analysis on Ground Subsidence in Underground Mining

Analysis on the characters of ground subsidence of Yangjiaping mining area, with same excavation depth and recovery coefficient, the numerical simulations to nonlinear large deformation using finite-difference method(FLAC) are achieved on the different strip extraction schemes that adopted different mining and reservation width. The result indicates that the subsidence values and horizontal deformation increases with the increasing of the strip extraction width on condition of the same recovery rate. Based on probability density function (PDF) method, the relationship of the coal pillar width, the mining width and ground deformation is acquired, which is some useful reference for using the strip extraction method to control the surface movement and deformation.

Influence of Cyclotron Magnet Gap Size on Stripping Extraction

The stripping extraction system of a cyclotron is prized by the range and quality of beams it delivers. The gap size of a cyclotron magnet is one of the parameters which significantly influence the design as well as the output characteristics of the stripping extraction system. The vertical dimension of the beam as well as of the extraction system elements placed inside a vacuum chamber is limited by the magnet gap size. Beside this direct influence, the indirect effect of the magnet gap size on stripping extraction occurs through the magnetic field and its impact on the beam dynamics in the extraction region. The performance of the extraction system is optimized by the proper placement of the point of beam exit from the cyclotron. It is shown that the optimal position of the exit point strongly depends on the magnet gap size. The performance of the optimized stripping extraction system for a smaller gap size is found to be somewhat better.

Overall design of CYCIAE-14, a 14 MeV PET cyclotron

Based on a 10 MeV CRM cyclotron developed at China Institute of Atomic Energy (CIAE) with an achieved beam intensity of up to 430 μA, a 14 MeV high intensity compact cyclotron, CYCIAE-14, was designed and being built at CIAE. It is planned that the first machine would be in place with a span of 2 years. CYCIAE-14 is delicately designed to realize strong vertical focusing by adopting a 4-sector, variable hill-gap structure with an external ion source to achieve high intensity. A special design applied to the stripping extraction gives access to dual extraction with four beams. The adoption of sophisticated industrial technology will give the cyclotron advantages, e.g. low power consumption and high reliability. This paper is aimed to present the overall design of the machine, including the basic technical specifications, main magnet and coils, RF, ion source and axial injection, and stripping extraction, etc. It will also give an introduction to its construction schedule as well as the up-to-date progress.

Comprehensive test stand for high-intensity cyclotron development

A comprehensive test stand for high-intensity cyclotron development, a 10 MeV 430 μA cyclotron, has been successfully constructed at China Institute of Atomic Energy (CIAE) for the experimental verification of the viability of a 100 MeV high-intensity cyclotron (CYCIAE-100) being constructed at CIAE. The verification includes the overall design technology, detail design and engineering technology for the crucial parts of the machine, e.g. main magnet and beam diagnostics. It will also pave the way for future enhancement of the beam intensity. The test stand consists of a H− ion source, axial injection system, central region, main magnet and coil, RF resonator, stripping extraction, and auxiliary systems, which include the RF power amplifier, high voltage and DC power supplies, electric apparatus, beam diagnostics, control, vacuum, water cooling, pneumatic system, and safety interlock. This paper presents the work regarding the design and sub-system development of the test sand, and the results of the beam commissioning of the machine.