Barium Chloride Solution Research Articles

Preparation of Lanthanum by the Lithium-thermic Method

Purification of unwanted impurities from rare earth products was carried out using inorganic and organic precipitating reagents. A 1 M solution of 8-hydroxycholine was used as organic precipitants. The use of organic precipitants forms stable intracomplex compounds with metal cations. Solutions of barium chloride and ammonia solution were used as inorganic precipitants. For the precipitant, specific and highly volatile precipitant reagents were chosen when heated. Iron, aluminum, sodium and sulfate ions were extracted from the product under study, because the chemical composition of the slag contains more of them. Enriched concentrated lanthanum chloride powder was reduced with lithium to lanthanum metal. Lanthanum is obtained in the form of large crystals with a purity of 99.6% by weight.

Surface modification of NF membrane via an environmentally friendly and rapid approach for desalination Process: Performance and stability evaluation

In this study, an environmentally friendly and rapid surface modification method known as surface mineralization was adopted to alter the polyamide (PA) layer of commercial NF270 thin film composite (TFC) membrane, aiming to improve its characteristics for enhanced desalination process. An alternate soaking process was applied on the membrane surface by using barium chloride solution and sodium sulfate solution at varying concentrations (0.01 M, 0.05 M and 0.1 M). The reaction of these two salts can form a layer of barium sulfate (BaSO4) minerals atop the PA layer via an ionic interaction. Our result revealed that the best-performing membrane could be developed using salt solutions at 0.05 M with its water contact angle descended to 33.5° compared to the pristine membrane of 46.4°. Furthermore, the surface roughness of the BaSO4-mineralized membrane was reported to be higher than the pristine membrane. The increase in surface roughness together with improved surface hydrophilicity yielded the BaSO4-mineralized membrane to exhibit 12% higher water flux than the pristine membrane. Nonetheless, the difference in Na2SO4 rejection before and after surface mineralization was not found to be statistically significant owing to the high Na2SO4 rejection of the control membrane. The BaSO4-mineralized membrane also achieved excellent performance in filtering solutions containing sodium alginate and showed very stable salt rejection for multiple cycle of combined chemical cleaning and water filtration process. These results highlighted the potential of the surface mineralization process in overcoming the trade-off effect between water flux and selectivity of TFC membrane.

Systemical investigation on the determination of sulfate in cement-based materials based on a promoted conductometric titrator

The concentration of sulfate ion in cement-based materials is the basic data for the design and evaluation of concrete structures exposed to sulfate lakes and saline soil areas. In this study, a conductivity titrator was developed and used to test the sulfate concentration in concrete corroded by sulfate attack based on the Internet of Things. The theories of conductivity measurement and conductivity titration were described; The main hardware composition and software design of conductometric titrator were introduced; Then, the effects of temperature, concentration, hydroxyl ion and hydrogen ion on the conductivity of solution of sodium sulfate and barium chloride were explored by the titrator; The titration parameters, the influence of hydroxyl and hydrogen ion on sodium sulfate titration were determined by test of sulfate ion titrated by barium chloride with known concentration; Finally, the titrator was used to test the sulfate concentration in cement-based materials after sulfate attack. The results show that the titrator can measure the conductivity of solution with 0.4% accuracy and the concentration of sulfate ion with 0.8% accuracy; During the titration of sulfate ion, the concentration of barium chloride should be twice that of sulfate ion, the titration rate should be less than 0.828 mL/s, and the titration volume should be at least 10 mL; It is found that the influence of hydroxyl ion can be effectively eliminated by adding nitric acid or hydrochloric acid, and the influence of hydrogen ion can be effectively eliminated by adding sodium carbonate. This conductivity meter can accurately test the sulfate concentration in the concrete after corrosion.

Effects of compost from urban solid household waste on the respiration of soil microbial flora and the yield of tomato (Lycopersicon esculentum) at the agronomic experimental station of Lome in Togo

The objective of the study is to evaluate the respiration of the microbial flora of soils amended with household waste compost under tomato cultivation. The experimental device adopted was that of complete random blocks with three repetitions. The compost was applied in doses of 10 t.ha-1, 20 t.ha-1, 30 t.ha-1 and 40 t.ha-1. To these treatments are added those of absolute control, mineral fertilization (0.2 t.ha-1 of NPK 15-15-15 and 0.1 t.ha-1 of Urea 46% N) and organo fertilization -mineral (10 t.ha-1 of compost combined with 0.1 t.ha-1 of NPK 15-15-15 and 0.05 t.ha-1 of Urea 46% N). Soil samples were taken from the plots at a depth of 0 - 20 cm and incubated in the laboratory for the evaluation of the respiration of the microbial flora. Soil CO2 emission was measured daily for 28 days of incubation using NaOH and 0.1 N HCl as titrant after precipitating the carbonate with barium chloride (BaCl2) solution by alkaline back titration in the presence of the colored indicator (phenolphthalein). The results showed that the application of compost from household waste induced an increase in CO2 emission from the soil (60.67-215.4 mg.kg-1 of soil) and fruit yield of tomato (8.61-36.43 t.ha-1). Thus the application of compost at the dose of 30 t.ha-1 improves soil biological activity and tomato fruit yield.

Comparative study of pregnancy diagnosis in ewes (Ovis aries) using barium chloride and progesterone-kit

One hundred and twenty sheep were used to test a low-cost technique for early diagnosis of pregnancy in sheep from July 2017 to June 2018. Different age groups were randomly categorized under four groups (15 to 30 days, 31 to 45 days, 46 to 60 days & 61 to 75 days). One mL barium chloride (1, 1.5 & 2%) was mixed with one mL of urine and kept for 5 to 10 minutes at room temperature: precipitation indicated non-pregnant. Three to five drops of serum were added to Bovipreg kit (progesterone-based kit) and left at room temperature for 5 minutes. One red line was interpreted as negative and two red lines positive for pregnancy. Barium chloride solution gave 67 - 70.5% accuracy. The accuracy for progesterone-based early pregnancy diagnostic kit was 80 - 85%. Progesterone-based early pregnancy diagnostic kit is much more accurate. The Bangladesh Veterinarian (2020) 37(1 - 2): 36-41

Sr2+ and Ba2+ salts induced conformational structure of sodium polyacrylate PAA investigated by molecular dynamics simulations

The shrinkage of sodium-poly(acrylate) PAA in divalent salt (strontium chloride (SrCl2) and barium chloride (BaCl2) solutions is investigated by atomistic molecular dynamics (MD) simulations to study the salt effect on PAA structure. The salt concentration (Cs) was varied in the range of 0 < Cs < 1 M for fully charged PAA. The PAA radius-of-gyration (Rg) decreases with Cs in the presence of both the divalent salts in qualitative agreement with experiments. The PAA chain stiffness calculated in persistence length (Lp) decreases over the entire range of Cs. At lower Cs, the PAA chains don't form aggregate, while at higher salt concentrations, PAA chains undergo self-association in both the divalent salts. The PAA-Water H-bonds decreases with Cs significantly in the presence of BaCl2 as compared to SrCl2. The PAA-Na+ radial distribution function (RDF) shows a decrease in its coordination number with Cs. The distribution of salt-ions around PAA shows that the Ba2+ condensation onto PAA is more significant than Sr2+ because of a greater coordination number for the former than the latter. Overall, the present study significantly advanced the molecular-level understanding of PAA microstructure in the dilute divalent metal salt solution.

Synthesis of a novel monofilament bioabsorbable suture for biomedical applications.

In this research, a novel bioabsorbable suture that is, monofilament and capable of localized drug delivery, was developed from a combination of natural biopolymers that where not previously applied for this purpose. The optimized suture formulation comprised of sodium alginate (6% wt/vol), pectin (0.1% wt/vol), and gelatin (3% wt/vol), in the presence of glycerol (4% vol/vol) which served as a plasticizer. The monofilament bioabsorbable sutures where synthesized via in situ ionic crosslinking in a barium chloride solution (2% wt/vol). The resulting suture was characterized in terms of mechanical properties, morphology, swelling, degradation, drug release, and biocompatibility, in addition to Fourier‐transform infrared (FTIR) spectroscopy, Powder X‐ray Diffraction (PXRD) and Differential Scanning Calorimetry (DSC) analysis. The drug loaded and non‐drug loaded sutures had a maximum breaking strength of 4.18 and 4.08 N, in the straight configuration and 2.44 N and 2.59 N in the knot configuration, respectively. FTIR spectrum of crosslinked sutures depicted Δ9 cm−1 downward shift for the carboxyl stretching band which was indicative of ionic interactions between barium ions and sodium alginate. In vitro analysis revealed continued drug release for 7 days and gradual degradation by means of surface erosion, which was completed by day 28. Biocompatibility studies revealed excellent hemocompatibility and no cytotoxicity. These results suggest that the newly developed bioabsorbable suture meets the basic requirements of a suture material and provides a viable alternative to the synthetic polymer sutures that are currently on the market.

Pregnancy diagnosis in goats (Capra hircus) using barium chloride and progesterone-based kit in Bangladesh

The study was conducted to develop a technique for early diagnosis of pregnancy in goats from July 2016 to June 2017. About 100 goats of different age groups were randomly selected for the trial and goats were categorized under four groups according to their gestation lengths (0.5 to 1 month, &gt;1 to 1.5 months, &gt;1.5 to 2 months and &gt;2 to 2.5 months). Blood from jugular vein and morning urine samples were collected from four groups and brought to the laboratory, and serum was separated from the clotted blood. Then 1%, 1.5% and 2% barium chloride solution were prepared and test was done by using 1 ml barium chloride of each concentration mixing with 1 ml of urine sample, and allowed for 5 and 10 minutes for interpretation. Presence of precipitation was interpreted as negative for pregnancy and absence of precipitation was interpreted as positive for pregnancy. For each blood sample, 3-5 drops of serum was added in each sample insertion hole of the Bovipreg kit and 5 minutes was allowed to observe the presence of one or two red line in the kit. One red line was interpreted as negative pregnancy and two red lines were interpreted as positive pregnancy. In our study 1% barium chloride, showed 93.5% accuracy, whereas 1.5% barium chloride provided 92% accuracy for the goats having 0.5 to 1 month of gestation. In case of 2% barium chloride, the highest accuracy was 91.5% for the goats having &gt;1 to 1.5 month of gestation. Conversely, the accuracy for progesterone-based early pregnancy diagnostic kit was 96.5%. Therefore, 1% barium chloride can be utilized for the diagnosis of pregnancy in goats. Asian J. Med. Biol. Res. 2022, 8 (1), 42-46

Safe, accurate, and precise sulfur isotope analyses of arsenides, sulfarsenides, and arsenic and mercury sulfides by conversion to barium sulfate before EA/IRMS

The stable isotope ratios of sulfur (δ34S relative to Vienna Cañon Diablo Troilite) in sulfates and sulfides determined by elemental analysis and isotope ratio mass spectrometry (EA/IRMS) have been proven to be a remarkable tool for studies of the (bio)geochemical sulfur cycles in modern and ancient environments. However, the use of EA/IRMS to measure δ34S in arsenides and sulfarsenides may not be straightforward. This difficulty can lead to potential health and environmental hazards in the workplace and analytical problems such as instrument contamination, memory effects, and a non-matrix-matched standardization of δ34S measurements with suitable reference materials. To overcome these practical and analytical challenges, we developed a procedure for sulfur isotope analysis of arsenides, which can also be safely used for EA/IRMS analysis of arsenic sulfides (i.e., realgar, orpiment, arsenopyrite, and arsenian pyrite), and mercury sulfides (cinnabar). The sulfur dioxide produced from off-line EA combustion was trapped in an aqueous barium chloride solution in a leak-free system and precipitated as barium sulfate after quantitative oxidation of hydrogen sulfite by hydrogen peroxide. The derived barium sulfate was analyzed by conventional EA/IRMS, which bracketed the δ34S values of the samples with three international sulfate reference materials. The protocol (BaSO4-EA/IRMS) was validated by analyses of reference materials and laboratory standards of sulfate and sulfides and achieved accuracy and precision comparable with those of direct EA/IRMS. The δ34S values determined by BaSO4-EA/IRMS in sulfides (arsenopyrite, arsenic, and mercury sulfides) samples from different origins were comparable to those obtained by EA/IRMS, and no sulfur isotope fractionations were introduced during sample preparation. We report the first sulfur isotope data of arsenides obtained by BaSO4-EA/IRMS.Graphical abstract

Radium removal from mine waters with the application of barium chloride and zeolite: comparison of efficiency

In several coal mines in the Upper Silesian Coal Basin (USCB), in Poland, radium removal from mine water was necessary in order to mitigate the negative results of radium release with mine effluents. The most efficient method of radium removal was based on the application of barium chloride, implemented in full technical scale in two Polish collieries. Removal efficiency exceeding 95% of the initial activity was achieved. The technology was implemented in full technical scale in two collieries. The problem was that barium chloride is dangerous to health and moreover continuous use of the powdered chemical was required to achieve good results. Therefore, the possible application of zeolite for radium removal was tested in laboratory experiments. This passive technique would be less hazardous for miners and would not require full-time supervision meaning it would enable a reduction in workload. The main goal of the investigations described in this paper was to check the capability of zeolites to remove natural radionuclides from mine waters and compare the removal efficiency of radium isotopes with the results obtained from the application of barium chloride solution for the same purpose.

Stability and Biocompatibility Tests of Alginate as Cochlear Implant Coating Material

Abstract Inner ear trauma caused by cochlear implantation is a severe clinical problem. It was shown that an electrode alginate coating can reduce the insertion forces in vitro. The grade of the alginate viscosity can be adjusted by using different metal ions for cross-linking the salts of the alginic acid. The aim was to investigate the stability and inner ear biocompatibility of alginate using different in vitro established cross-linkers. Alginate beads were cross-linked in either calcium chloride (CaCl2) or barium chloride (BaCl2) solution. The beads were cultivated in artificial perilymph and stability and swelling were observed for 13 months. Ototoxicity was tested on cochlear whole mount explants from neonatal rats. Neomycin served as positive control to induce hair cell damage and explants without any addition served as negative control. The beads and explants were co-cultured for 48 hours and the hair cell survival was analysed microscopically. Neomycin treatment induced an extensive inner and outer hair cell loss. Neither CaCl2 nor BaCl2 cross-linked alginate beads caused any damage to the hair cells. Even though the same volume of alginate and cross-linkers were used, in CaCl2 cross-linked beads were initially almost double the size of in BaCl2 cross-linked beads. None of the cross-linked alginate beads had a significant volume change within 3 months being cultured in artificial perilymph. After 3 months the CaCl2 cross-linked beads swelled massively and dissolved within one week whereas BaCl2 cross-linked alginate beads remained unchanged until month 13 after culture start. Alginate beads gelled with both cross-linkers are biocompatible with the inner ear sensory epithelium. Both cross-linkers ensure a stable gelation of alginate but a swelling followed by degradation of the in CaCl2 cross-linked beads occurred after 3 months. For coatings, which need to be long term stable, BaCl2 should be chosen whereas CaCl2 may be more suitable for applications where limited stability is needed and the swelling is not affecting the surrounding tissue. Therefore, BaCl2 cross-linking of alginate may be the best choice for cochlear implant coating.

ELECTROCHEMICAL SYNTHESIS OF DISPERSED BARIUM FERRITE USING ANODIC DISSOLUTION OF METAL

The process of anodic dissolution of iron (purity not less than 99%) in aqueous solutions of barium chloride, barium nitrate and binary electrolytes under galvanostatic conditions and by registration of potentiodynamic polarization curves was investigated. The influence of solution composition and concentration and the value of applied direct current on the intensity of anodic oxidation of iron was shown. It was revealed that the oxidation rate of metal in binary electrolytes containing barium chloride and barium nitrate is comparable with the intensity of anodic dissolution in a solution based on barium chloride. It was found that anodic polarization curve in solutions containing BaCl2 and Ba(NO3)2 has a complex form typical of passivated metals. There is a clear maximum of anodic oxidation current on this curve, as well as in barium nitrate solution, however the peak height is much higher (50-150 times). A method for the synthesis of dispersed barium ferrite, based on the anodic oxidation of iron in aqueous barium chloride and barium nitrate solutions with subsequent thermal treatment of the product of electrochemical dissolution was suggested. The phase and elemental composition and structural characteristics of obtained precursor and ferrite samples were examined using X-ray phase analysis. The influence of the heat treatment mode on the phase composition of the synthesized samples is shown. It is found that electrolysis with a soluble iron electrode using direct anode current in 0.05M BaCl2 + 0.5M Ba(NO3)2 solution and subsequent thermal treatment of the dissolution product at 1200 ° C provide the formation of dispersed system, whose phase composition is predominantly Ba0.87Fe11.08O17.15 (74%) and BaFe2O4 (17%).

Adsorption and Separation of Carbon Dioxide/Methane in Landfill Gas with Barium Ion–Modified Silica Gel

Environmental issues caused by greenhouse gases are becoming more and more severe. The main components of landfill gas, carbon dioxide (CO2) and methane (CH4), are greenhouse gases, and the separation and recovery of them are a popular research topic. In order to improve the adsorption capacity of the silica gel adsorbent for landfill gas, a method such as modify silica gel with alkali metal ions is often used. It is to improve the selective adsorption capacity of CO2 by adjusting the polarizability and charge distribution of the silica gel surface while improving the separation effect of the mixed gas. In this study, the adsorption performance of a silica gel adsorbent modified or not with alkali metal ions was measured in terms of the adsorption and separation of a CO2/CH4 mixture (simulating landfill gas). The N2 adsorption and desorption curve of the silica gel adsorbent at 77 K was plotted by determining the specific surface area and pore-size distribution. The results indicated that the unmodified silica gel adsorbent had a large micropore volume and specific surface area and exhibited a high capacity to adsorb gas. After potassium chloride, calcium chloride, magnesium chloride, or barium chloride solution was used to modify the silica gel adsorbent, the adsorption performance of the modified silica gels was ranked as barium chloride > potassium chloride > calcium chloride > magnesium chloride. The best-performing concentration of barium chloride solution was 0.1 mol/L. The research results will provide certain reference for the fields of chemistry and environmental science.

Application of Phosphate Precipitation for Removing Strontium and Barium from Alkali Chloride Based Melts

Alkali chloride based melts can be used as working electrolytes in prospective technologies of pyrochemical reprocessing of spent nuclear fuels. After extracting fissile materials the melts contain ions fission product elements having more negative electrode potentials than uranium and plutonium. These include rare earth, alkaline earth and alkali metals. One of possible methods for removing rare earths from alkali chloride based melts is phosphate precipitation. Alkaline earth metals also form sparingly phosphates and therefore phosphate precipitation can be potentially used for removing strontium and barium from molten electrolytes.The present work was aimed at studying the reaction of solutions of strontium or barium chloride in alkali chloride based melts with sodium orthophosphate. The experiments were conducted in LiCl–KCl and NaCl–KCl–CsCl eutectic based melts at 550 oC, and in NaCl–KCl equimolar mixture at 750 oC.To determine the conditions required for complete removal of strontium and barium, the initial phosphate-to-barium molar ratio in the melt was set at 0.5; 1; 2; 4; 6 and 8. Residual alkaline earth content in the melt was determined by chemical analysis. Precipitated strontium and barium phosphates were subjected to X-ray powder diffraction analysis.Selecting a possible method of separating solid precipitate from molten salt requires information on size of particles forming the solid phase. Particle size was determined by laser diffraction and examples of particle size distribution curves for precipitates formed in LiCl–KCl–BaCl2 melts are shown in Fig. The precipitates consisted of particles ranging from 0.5 to 100 microns. Increasing the initial PO4 3– : Ba2+ molar ratio resulted in increasing particle size but even at the molar ratio of six over 50 % particles were less than 10 μm.Fig. Particle size distribution curves for barium phosphate precipitated from LiCl–KCl eutectic based melts at 550 oC. Initial PO4 3– : Ba2+ mole ratio was 0.5 (line 1); 1.0 (2); 2.0 (3); 4.0 (4) and 6.0 (5). Figure 1

Barium blockade of the KcsA channel in open and closed conformation datasets.

Barium is a potent blocker of the KcsA potassium channel. A strategy using x-ray crystallography and molecular dynamics (MD) simulation has been used to understand this phenomenon as described in Rohaim et al. [1]. Wild type KcsA is purified to homogeneity and crystallized in low and high K+ conditions. Crystals are grown using the hanging drop vapor diffusion method. To examine barium binding in the selectivity filter of KcsA, the crystals are systemically soaked in various concentrations of barium chloride solution. X-ray crystallography datasets are collected at the Advanced Photon Source. A total of 10 datasets are collected for various barium ion concentrations. Diffraction data are processed using the crystallography pipeline software RAPID. The crystal structures are solved by molecular replacement methods. The structure models are visualized using COOT and refined using REFMAC. Anomalous map coefficients are calculated using the phenix.maps tool in the PHENIX software suite. The datasets are deposited in the Protein Data Bank. The data provides a detailed picture of barium ion interaction with potassium channels. Structural analysis of the KcsA channel reveals two distinct configurations, open- and closed- state. Further MD simulation analysis suggests an energetically favorable binding mechanism for barium ion in the selectivity filter. The data could be used to interpret functional experiments related to barium blockade for potassium channels. Also, it is valuable for comparison and cross validation with other relevant potassium channel structures.

Corrección de la acidez del suelo : alteraciones químicas del suelo

La alternativa más común para corregir la acidez del suelo consiste en el empleo de enmiendas calcáreas. El objetivo de esta investigación fue determinar el efecto del encalamiento en la fertilidad de algunos suelos representativos de la zona cafetera de Colombia. Se evaluaron las propiedades químicas de cinco suelos luego de un mes de incubación con cinco dosis de cal (0; 1,25; 2,50; 5,00 y 10,00 g dm-3). Los tratamientos afectaron diferencialmente a los suelos en su pH, Ca2+, Mg2+, CIC, Al3+, Fe2+, Mn2+, NO3-, saturación de bases y relación de bases intercambiables. El pH del suelo logró explicar con mayor ajuste las variaciones de Al3+ que el porcentaje de saturación de Al3+. La CIC, determinada mediante el acetato de amonio 1 M y con pH=7,0, no fue un método adecuado para determinar el efecto del encalamiento; caso contrario ocurrió con la solución no-tamponada de cloruro de bario. Se presentó una alta correlación entre el porcentaje de saturación de bases y el pH para cada suelo; sin embargo, no se encontró una tendencia que pudiera explicar las variaciones de todos los suelos de manera conjunta. Los cambios de la CIC, generados por el incremento del pH que ocasionó el encalamiento, estuvieron en función de los contenidos de la materia orgánica. Una parte de los contenidos de Ca y Mg determinados en el análisis del suelo correspondió a la fracción no intercambiable, resultado que se relacionó con la baja solubilidad de la cal y soporta su efecto residual.

Visual Colorimetric Determination of Sulfate Ion in Water Using Coprecipitation Phenomenon of Potassium Permanganate and Barium Sulfate

An on-site analytical technique for the colorimetric determination of sulfate ion in a water sample was developed based on the formation of purple precipitates as mixed crystals composed of barium sulfate with permanganate. Potassium permanganate solution and acidic barium chloride solution with hydrochloric acid were added in sequence into 1.5 mL of the sample, then the mixed crystals precipitated and suspended. The residual excess of permanganate ion remaining in the mother solution was reduced with ascorbic acid to turn it colorless. At that time, colors of the suspended precipitates became observable. The intensity of purple color tone of the suspension varied depending on the concentration of sulfate ion. The concentration was determined semi-quantitatively by visual comparison of the intensity with standard color charts. The proposed colorimetry permitted us to determine sulfate ion at the range of 50 to 2000 mg L−1. The time required for the on-site analysis was less than one minute. We applied the colorimetry to the real drainage samples taken from biological desulfurization systems and obtained good results useful for maintenance of them.

Study of Barium Sulfate Scale Dissolution into Ethylenediaminetetraacetic acid (EDTA)

Barium sulfate (barite) scale deposition may cause the problem in surface and subsurface production equipment resulting in reduced production, decrease in pressure, and premature failure of down holes equipment. One of the barite scale management is by using dissolver. There are many chelating agents that can be used to dissolve this scale including ethylenediaminetetraacetic acid (EDTA). In this work, EDTA is used to dissolve the laboratory-reproduced barium sulfate scale. Barite scale was reproduced in the laboratory by mixing barium chloride (BaCl2) solution and sodium sulfate (Na2SO4) solution at 25°C. The sensitivity analysis was performed to determine the optimum parameters/conditions in which EDTA dissolution is optimum through Inductively Coupled Plasma Optical Emission Spectrometry (ICP-EOS) analysis and characterization study using Field Emission Scanning Electron Microscope (FESEM). This includes the effect of agitation, temperature, pH, catalyst used, and the presence of oxalate ion. These laboratory tests showed that the solubility of barite increased as it was agitated; at high pH of 11 to 13; and at elevated temperature of 95°C. Potassium chloride (KCl) at high elevated temperature was used as synergy/activator to improve the dissolution of barium sulfate with EDTA. As a conclusion, this project sets a framework to identify the best EDTA formulation and estimate its dissolution profile to ensure a more informed treatment design for barite scale removal.

Microcirculation changes of three yin-meridians of hand in the forearm in rabbits with arrhythmia: a comparative study

To observe the microcirculation changes of three yin-meridians of hand in the forearm in rabbits with arrhythmia, and to compare the differences of responses among the three yin-meridians of hand. A total of 20 New Zealand rabbits were randomly divided into a saline group and a model group, 10 rabbits in each one. The rabbits were anesthetized with intravenous injection of 20% ethyl carbamate (3.3 mL/kg) at ear vein; the saline group was injected with 0.9% sodium chloride solution (1 mL/kg), while the model group was injected with 0.4% barium chloride solution (1 mL/kg) to establish the arrhythmia model. The microcirculation changes of the three yin-meridians of hand were observed and analyzed by laser speckle blood flow imaging technique before and after the intervention. Compared before modeling, the microcirculation perfusion of the three yin-meridians of hand in the model group was significantly reduced (P<0.01), and the reduction in the jueyin meridian was more significant than that in the shaoyin meridian (P<0.05), but there was no significant difference between the taiyin meridian and shaoyin meridian (P>0.05). There was a negative correlation between microcirculation perfusion and position (P<0.001), indicating the closer to the elbow, the more the microcirculation perfusion decreased. During arrhythmia in rabbits, the dysfunction of qi and blood existes in the three yin-meridians of hand in the forearm, particularly the jueyin meridian. In addition, the closer to the elbow, the more obvious the reaction of the three yin-meridians of hand is.

Microfluidic flow-through reactor and 3D Raman imaging for in situ assessment of mineral reactivity in porous and fractured porous media.

An in-depth understanding of dissolution and precipitation of minerals in porous and fractured porous media and the complex feedback on the transport of fluids is essential for various subsurface applications. In this context, we developed a novel non-destructive "lab-on-chip" approach for quantitative in situ assessments of mineralogical changes in porous media. Our experimental approach involves a microfluidic flow-through reactor of reactive homogeneous and heterogeneous (fractured) porous media coupled with high-resolution imaging. Here, the reactive medium consists of compacted celestine grains seeded in a reservoir within the microfluidic chip. This medium reacts with a barium chloride solution injected into the microreactor at a constant flow rate, leading to the dissolution of celestine and growth of barite. Various seeding processes of the mineral grains allow the creation of homogeneous reactive porous media or the introduction of large heterogeneities such as fractures. Hence, our approach enables high-resolution investigations of reactive transport in fractured porous media. The use of confocal Raman spectroscopic techniques enables the spatio-temporal visualization of the mineral transformation at the pore-scale in two- and three-dimensions. Moreover, advanced pore-scale modelling correlates the hydrological heterogeneities to the geochemical observations in the micro-reactor, which explains the observed discrepancies between homogeneous and heterogeneous reactive media. Eventually, the proposed methodology can be applied to other chemical systems to provide new insights into hydro-geochemical coupling in porous and fractured porous media as well as high-fidelity datasets to benchmark reactive transport codes that are currently under development.