Dissolution Procedure Research Articles

Characterization and utilization of apple peel and grape stems extract constituents as green restraints for aluminum dissolution

Different flavone extracts from apple peel and aldehydes from grape stems were investigated as restraints of the anodic aluminum dissolution procedure in 60% H3PO4:40% H2SO4. The potential-limiting current correlation for Al anode was assessed and associated with regularly improving apple peel and grape stems extract concentration (100 to 1000 ppm range). The limiting current reduces whereas retardation effectiveness (%) increases as the concentrations of apple peel and grape stems extract rise. Apple peel/grape stems mixture extract is pondered to have the most retardation impact. Apple peel and grape stems extract retardation mechanism depends on the adsorption manner at the aluminum metal, which was confirmed via scanning electron microscopy (SEM) and UV-VIS-NIR spectra which reflect that elevated extract concentration (1000 ppm) have a hopeful and positive impact on the Al surface quality. The activation energy and activation constraints (changes in enthalpy, entropy, and Gibbs free energy) were established, and suggestions for powerful interaction between the additives and the aluminum surface were conveyed. The extract items were inspected via Fourier transform infrared spectroscopy and Gc-mass. The apple peel and grape stems extract establish perspective as a natural electro-polishing green restraint. The weight loss data obtained is in excellent conformity with the result obtained by electrochemical measurements. The synergistic influence between apple peel/grape stems (S = 1.64–1.83 ) is noticeable. The lowest Ra and PV estimates are recorded via an apple peel /grape stems mixture, which achieves the greatest reflectance estimate and retardation effectiveness. This is recognized high active site number for apple peel /grape stems mixture extract.

О скрытых процессуальных правилах рассмотрения дел о расторжении брака (часть первая)

The Family Code of the Russian Federation contains a lot of procedural provisions related to the process of dissolution of marriage between spouses. However, there are almost no such special provisions in the structure of provisions of civil procedure laws. It turns out that the marriage dissolution procedure does not differ from other civil case review and resolution procedures from the procedural standpoint. However, this is not the case from the objective legal standpoint. In this article, the author shows hidden but actually existing procedural rules for review of marriage dissolution cases that need to be taken into account and observed at resolution of respective civil cases.

Experimental measurement, thermodynamic analysis, and mathematical modeling for budesonide solubility in 1-propanol + water mixtures at T = (293.2 to 313.2) K.

Budesonide (BDS) a steroid-based anti-inflammatory drug widely prescribed for various diseases, has a low aqueous solubility. In this study, we investigated cosolvency approach to study the thermodynamic specifications related to the solubility of BDS at the temperature range of 293.2-313.2K in (1-propanol + water) mixtures applying the shaking flask method. The predictive power of different mathematical models for experimental data in the cosolvency systems was evaluated. For this purpose, the linear and nonlinear mathematical equations such as van't Hoff model (as a linear model), Buchowski-Ksiazczak equation (as a non-linear), CNIBS/R-K and MRS models (as a linear model for solvent composition at an isothermal condition), modified Wilson model (as a non-linear model for isothermal condition), the Jouyban-Acree model (as a model that considers temperature and solvent composition), and Jouyban-Acree-van't Hoff model (as a model with no further input data) were studied. Also, the Williams-Amidon excess Gibbs energy model was investigated. In addition, the related apparent thermodynamics of the BDS dissolution process in the desired temperature such as Gibbs free energy, enthalpy, and entropy, were computed by the corresponding equations. Moreover, based on the inverse Kirkwood-Buff integrals, it is demonstrated that BDS is preferentially solvated by water in water-rich mixtures. The accuracy of the fitness was evaluated with mean relative deviations (MRDs%) for back-calculated molar BDS solubility data. The result showed that the maximum solubility of BDS was obtained at 0.7 mass fraction of 1-propanol at all temperatures. Thermodynamic studies demonstrated that BDS dissolution procedures were obtained as endothermic and entropy-driven in almost all cases. The overall MRDs% values for the back-computed BDS solubility in the aqueous mixture of 1-propanol based on van't Hoff model, Buchowski-Ksiazczak equation, CNIBS/R-K model, modified Wilson model, Jouyban-Acree model, Jouyban-Acree-van't Hoff model, MRS model, and Williams-Amidon excess Gibbs energy model were found 1.93%, 1.80%, 11.68%, 33.32%, 12.30%, 9.24%, 10.70%, and 6.57%, respectively.

Determination of rare earth elements in ferrocarbonatite using ICP-AES and ICP-MS

AbstractA method has been developed for the determination of Rare Earth Elements (REEs) in ferrocarbonatite using Inductively Coupled Plasma—Atomic Emission Spectrometer (ICP-AES) and Inductively Coupled Plasma—Mass Spectrometer (ICP-MS). The conventional dissolution procedures are tedious, with large measurement uncertainty and are thus not suitable for certified reference material (CRM) production and exploration of REEs. The described method involves leaching of sample using 3 M HCl followed by dissolution of residue (silica and REEs) by HF then determined REEs using ICP-AES and ICP-MS. The leaching step prevents formation of fluoride precipitates of matrix (Ca, Mg, Ba and Al). The method has been validated using CRMs.

An Analytical Method for Quantification of Sn Isotope Variations in Geological Materials Using MC‐ICP‐MS

A robust analytical method is presented here, for measurements of Sn isotope variations with high precision using a multi‐collector inductively coupled plasma‐mass spectrometer (MC‐ICP‐MS). A silicate rock dissolution procedure was used, together with means to remove organic matter introduced by the resin during ion‐exchange chromatography. The two‐stage ion exchange chromatography efficiently isolates Sn from the matrix and isobarically interfering elements, from samples with variable Sn mass fractions (~ 0.03 to 7 μg g−1). A double spike technique was also implemented to correct any secondary mass bias induced during sample processing and isotope ratio measurements. An intermediate precision (2s) of ± 0.47 was obtained for ε122/118Sn (using internal normalisation; n = 70 over a period of 29 months), ± 0.021‰ for δ122/118Sn (using double spike; n = 176 over a period of 29 months) and ± 0.059‰ for δ122/118Sn (using Sb doping; n = 34 over a period of 4.5 months) for the Sn standard solution, NIST SRM 3161a (Lot# 140917). The δ122/118SnNIST SRM 3161a of eleven geological reference materials are reported for the first time (BIR‐1a, BRP‐1, DTS‐2b, ECRM 782‐1, JP‐1, OKUM, QLO‐1a, RGM‐2, SGR‐1b, STM‐2 and UB‐N), with five others (AGV‐2, BCR‐2, BHVO‐2, GSP‐2 and W‐2a) showing similar results to previous studies, generally with improved precision. The intermediate precision (2s) of replicate dissolutions of ten RMs (AGV‐2, BCR‐2, BHVO‐2, BIR‐1a, DTS‐2b, GSP‐2, OKUM, SGR‐1b, STM‐2 and W‐2a) varied from 0.003 to 0.054‰. Typical repeatability precision (2SE) of individual measurements of these ten RMs over multiple measurement sessions varied from 0.031 to 0.297‰ (with 120Sn+ beam intensity < 2.37 V) and 0.017 to 0.025‰ (with 120Sn+ beam intensity > 2.37 V).

In-situ monitoring of in vitro drug release processes in tablets using optical coherence tomography

Film-coated modified-release tablets are an important dosage form amenable to targeted, controlled, or delayed drug release in the specific region of the gastrointestinal (GI) tract. Depending on the film composition and interaction with the GI fluid, such coated products can modulate the local bioavailability, systemic absorption, protection as an enteric barrier, etc. Although the interaction of a dosage form with the surrounding dissolution medium is vital for the resulting release behavior, the underlying physicochemical phenomena at the film and core levels occurring during the drug release process have not yet been well described. In this work, we attempted to tackle this limitation by introducing a novel in vitro test based on optical coherence tomography (OCT) that allows an in-situ investigation of the sub-surface processes occurring during the drug release. Using a commercially available tablet based on osmotic-controlled release oral delivery systems (OROS), we demonstrated the performance of the presented prototype in terms of monitoring the membrane thickness and thickness variability, the surface roughness, the core swelling behavior, and the porosity of the core matrix throughout the in vitro drug release process from OROS. The superior spatial (micron scale) and temporal (less than 10 ms between the subsequent tomograms) resolution achieved in the proposed setup provides an improved understanding of the dynamics inside the microstructure at any given time during the dissolution procedure with the previously unattainable resolution, offering new opportunities for the design and testing of patient-centric dosage forms.

Hydrophobin-Coated Perfluorocarbon Microbubbles with Strong Non-Linear Acoustic Response

Gas-filled microbubbles are well-established contrast agents for ultrasound imaging and widely studied as delivery systems for theranostics. Herein, we have demonstrated the promising potential of the hydrophobin HFBII—a fungal amphiphilic protein—in stabilizing microbubbles with various fluorinated core gases. A thorough screening of several experimental parameters was performed to find the optimized conditions regarding the preparation technique, type of core gas, HFBII initial concentration, and protein dissolution procedure. The best results were obtained by combining perfluorobutane (C4F10) gas with 1 mg/mL of aqueous HFBII, which afforded a total bubble concentration higher than 109 bubbles/mL, with long-term stability in solution (at least 3 h). Acoustic characterization of such microbubbles in the typical ultrasound frequency range used for diagnostic imaging showed the lower pressure resistance of HFBII microbubbles, if compared to conventional ones stabilized by phospholipid shells, but, at the same time, revealed strong non-linear behavior, with a significant harmonic response already at low acoustic pressures. These findings suggest the possibility of further improving the performance of HFBII-coated perfluorinated gas microbubbles, for instance by mixing the protein with other stabilizing agents, e.g., phospholipids, in order to tune the viscoelastic properties of the outer shell.

Application of the variability budget approach to the Dissolution test

The aim. This study aimed to evaluate the completeness of our knowledge about the sources of variation in the Dissolution test with 100 % release by compiling a variability budget.
 Materials and methods. The study was performed on 500 mg metformin tablets, using pharmacopoeial quality reagents, State Pharmacopoeia of Ukraine (SPhU) Metformin HCl reference standard, Pharmatest DT70 Dissolution apparatus, Perkin Elmer Lambda 35 spectrophotometer, Mettler Toledo XP 204 analytical balance, and ISO class A volumetric glassware. The SPhU metrological approach was employed.
 Results and discussion. The variability budget was compiled based on the comparison of uncertainty estimates obtained from the requirements for maximum permissible variation in normal analytical practice (UNAP, bottom-up estimation) and experimental data (Uexp). This involved characterizing Metformin content in tablets using the Uniformity of Dosage Units (UDU) test as an independent method. The 100 % release of Metformin in the Dissolution test (infinity point) was proved by increasing the dissolution time. Having optimized Dissolution and UDU analytical procedures for variability budget compiling, we achieved insignificance of Uexp compared to the target uncertainty (Utg) for the Dissolution test in compliance testing. The differences in UDU and Dissolution mean results did not exceed UNAP for the release time of 45 and 60 min, i.e. uncertainty budget was proven. Uexp for the Dissolution test indicated the presence of an unknown statistically significant source of random variation, which, however, was less than Utg; therefore, the procedure is suitable for compliance testing.
 Conclusion. Experimental results confirmed the completeness of our knowledge about sources of variation (absence of bias) for the Dissolution test with 100 % release. An essential condition for compiling the budget was the optimization of uncertainty of analytical procedures. For UDU, all significant sources of variation were within the expected range. Yet, there is a need for additional research to identify and manage an unknown source of practically significant random variation for the Dissolution test

Dissolution behavior of stone wool fibers in synthetic lung fluids: Impact of iron oxidation state changes induced by heat treatment for binder removal

Stone wool fiber materials are commonly used for thermal and acoustic insulation, horticulture and filler purposes. Biosolubility of the stone wool fiber (SWF) materials accessed through acellular in vitro dissolution tests can potentially be used in future as an indicator of fiber biopersistence in vivo. To correlate acellular in vitro studies with in vivo and epidemiological investigations, not only a robust dissolution procedure is needed, but fundamental understanding of fiber behavior during sample preparation and dissolution is required. We investigated the influence of heat treatment procedure for binder removal on the SWF iron oxidation state as well as on the SWF dissolution behavior in simulant lung fluids (with and without complexing agents). We used heat treatments at 450 °C for 5 min and 590 °C for 1 h. Both procedures resulted in complete binder removal from the SWF. Changes of iron oxidation state were moderate if binder was removed at 450 °C for 5 min, and there were no substantial changes of SWF’s dissolution behavior in all investigated fluids after this heat treatment. In contrast, if binder was removed at 590 °C for 1 h, complete Fe(II) oxidation to Fe(III) was observed and significant increase of dissolution was shown in fluids without complexing agent (citrate). PHREEQC solution speciation modeling showed that in this case, released Fe(III) may form ferrihydrite precipitate in the solution. Precipitation of ferrihydrite solid phase leads to removal of iron cations from the solution, thus shifting reaction towards the dissolution products and increasing total mass loss of fiber samples. This effect is not observed for heat treated fibers if citrate is present in the fluid, because Fe(III) binds with citrate and remains mobile in the solution. Therefore, for developing the most accurate SWF in vitro acellular biosolubility test, SWF heat treatment for binder removal is not recommended in combination with dissolution testing in fluids without citrate as a complexing agent.

CCQM-K160: platinum group elements in automotive catalyst

Main textThe platinum group elements (PGEs) play an important role in reducing emissions from automotive vehicles through their use in catalytic convertors but also for catalysis in the pharmaceutical industry. The immense economic value of platinum (Pt), palladium (Pd) and rhodium (Rh) highlights the importance of highly accurate measurements. Therefore, there is a need for National Metrology Institutes (NMIs) and Designated Institutes (DIs) to demonstrate measurement capability in this space.A pilot comparison (CCQM-P63) for precious metals in automotive catalyst took place in 2006, but with a limited number of institutes participating. Furthermore, this study was performed over 17 years ago. Therefore, there was a need to maintain existing capability and demonstrate new capability in a key comparison, in order to claim calibration and measurement capability claims (CMCs). With the core capability matrix, this study falls into the "Difficult to dissolve metals/metal oxides" which will support CMC categories 8 (Metal and metal alloys), 9 (Advanced materials) and 14 (Other materials).Eleven NMIs and DIs participated in the Key Comparison CCQM-K160 Platinum Group Elements in Automotive Catalyst. Participants were requested to evaluate the mass fractions of Pt, Pd and Rh in mg/kg in an unused autocatalyst material (cordierite ceramic base). The Key Comparison Reference Values (KCRVs) and Degrees of Equivalence (DoEs) were calculated utilising the NIST Decision Tree for the measurands. The participants utilised a number of sample preparation and analytical methods including hot plate digestion, microwave digestion and sodium fusion, followed by either atomic absorption spectroscopy (AAS), inductively coupled plasma optical emission spectroscopy (ICP-OES) or inductively coupled plasma mass spectrometry (ICP-MS) detection. Several calibration techniques were used, namely external calibration, standard addition, isotope dilution mass spectrometry (IDMS) and an exact matching procedure. Additionally, one participant employed instrumental neutron activation analysis (INAA) with k0 standardisation which is a direct solid analysis method. The majority of participants claimed traceability to NIST primary calibrants or their own CRMs. Furthermore, several matrix CRMs were included or spiked samples for quality control. All institutes were required to determine the dry mass fraction using the stipulated protocol.The NIST decision tree was implemented for the calculation of the KCRVs and DoEs. The participant results overall showed good agreement with the KCRV, despite the variety of dissolution procedures and measurement techniques for this highly complex matrix and challenging measurands. Successful participation in CCQM-K160 demonstrated measurement capabilities for the determination of mass fraction of Pt, Pd and Rh in the mg/kg range and will support broad scope CMC claims for a wide range of challenging matrices.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Energy saving Chemical Beneficiation Method of Improving Low Grade Nigeria Chromite Ore for Use in Steel Industries

This study detailed how direct acid leaching can be used to extract high grade chromite from low grade chromite ore for utilization in the steel industry. The suggested method, which makes use of nitric acid, avoids using traditional pyrometallurgical processes because they use a lot of energy. The leaching procedure is adjusted in accordance with the circumstances that will maximize chromium recovery. In this context, the independent variables are the nitric acid concentration (0.5–4 M), temperature (28–80°C), liquid to solid ratio (L/S) (3–10 mL g–1), and leaching period (10–120 min). The three parameters that affect the leaching process most effectively are, in order, acid concentrations, temperature, and particle sizes. By doing this, 86.7% of the chromite in the lean chromite ore was recovered. Shirking core model examination of the kinetics of leaching reveals that internal diffusion reaction controls the rate of leaching, and the apparent activation energy calculated is 24.8 kJ.mol-1. This approach is successful and relatively inexpensive for chromite beneficiation. The gap is thus filled by the use of all-known inefficient acid dissolution procedures, which are less expensive and could serve as an alternate way of chromite beneficiation for use in iron and steel.

Impacts of chemical pre-treatments on the hydrogen isotope composition of clay minerals: Determining potential effects in the absence of impurities

The structural hydroxyl hydrogen (H)-isotope compositions of clay minerals are frequently used as tracers of alteration or change in paleoenvironmental and material science studies. Dissolution pre-treatments are commonly used to remove cements and H-bearing impurities prior to isotopic analysis. These pre-treatments commonly include reactions respectively with: HCl or acetic-acetate buffer, H2O2 or NaClO, and a Na-dithionite-Na-citrate-bicarbonate (DCB) solution in order to remove carbonates, organic matter, and iron (oxy)hydroxides. However, there has been inconsistent data regarding to what extent the structural hydroxyl H-isotope composition of a clay mineral is altered during exposure to these chemical pre-treatments.This study examined the “most extreme” impacts of each pre-treatment on the structural H-isotope composition of reference nontronite, montmorillonite, saponite, and kaolinite samples obtained from the Clay Minerals Society Source Clay Repository. All chemical reagents were isotopically labeled to a δ2H value ≈ +200 or +570‰, to sharply contrast the average clay starting material δ2H value ≈ –120‰. H-isotope compositions were measured before and after pre-treatments by High Temperature Elemental Conversion (TCEA) coupled with an Isotope Ratio Mass Spectrometer (IRMS). TCEA-IRMS measurements were done on potassium (K)-exchanged samples pre-dried under active vacuum at 220 °C to mitigate isotopic contamination by adsorbed water vapor.The results showed that only the H-isotope composition of kaolinite was unaffected by all pre-treatments. NaClO and DCB treatments affected the H-isotope compositions of saponite and nontronite, respectively, with the remaining pre-treatments not causing measurable changes for these two clay minerals. The HCl and H2O2 pre-treatments caused massive alteration to the H-isotope compositions for montmorillonite and are considered unadvisable for use with this clay mineral, with respect to H-isotope analysis. The study confirms the possibility of altering the H-isotope composition of clays when using common selective dissolution procedures. The choice of applied pre-treatments before H-isotope measurements for clay-bearing materials should be based on the specific properties and mineralogy of the investigated samples and the amount and type of impurities they contain.

A Review on Dissolution Method Development for Drug Products: Current Regulations and Prospects

Dissolution (in vitro release) testing has been the subject of intense scientific and regulatory interest over the past several decades. As an analytical methodology, in vitro dissolution testing measures drug release into the dissolution media. The U. S. Food and Drug Administration (USFDA) Dissolution Database was reviewed and screened regarding the type of dosage forms, apparatus type, agitation speed, media volume, and recommended time points for the dissolution profile. The dissolution method requires special laboratory equipment, following a well-defined protocol. Basic information is available in the United States Pharmacopeia general chapters<711> Dissolution, <724> Drug Release, and <1092> The Dissolution Procedure – Development and Validation and these chapters were used as a starting point for this revision. The article describes current regulatory expectations for establishing a suitable dissolution method for implementing quality control tools, a way to maintain lot quality and consistency between development batches and post-approval commercial batches. Dissolution methods draw offers some advantages as a possible surrogate for extensive clinical studies in certain cases required after scale-up and post-approval changes in the product's life cycle and serves as an essential tool for establishing waivers for filing of lower strengths of the drug product. The step-by-step dissolution method development plan as per current regulatory perspectives and the factors to be considered are explained with examples. Scientist requires detailed insights on the selection of media and volumes, physicochemical properties of active substance, sink condition, type of enzymes, selection of apparatus, deaeration, sinkers, agitation speed, and time point’s measures. The advanced dissolution method is evaluated against its discriminatory power by intentionally varying formulation and process variables

A sequentially coupled chemical-mechanical damage constitutive model for carbonate rocks

Modelling the constitutive relations of chemically corroded carbonate rocks is important for the design and stability evaluation of engineering constructions in karst areas (e.g., mines, tunnels and dams, etc.) [1-4]. This paper presents a sequentially coupled chemical-mechanical (C-M) damage constitutive model for engineering rocks in karst areas. First, the chemical damage caused by carbonate dissolution and the mechanical damage caused by external loads are investigated based on experimental results. After that, the chemical damage is expressed by the degradation ratio of Young's modulus under the effect of the chemically induced secondary pores compaction. The chemically induced secondary pore is quantified by reactive transport behavior considering the geochemical procedure of free-face dissolution and precipitation under different H+ concentrations, temperature and corrosion periods [5]. The mechanical damage is formulated based on a statistical theory [6,7], which underlines the strength of the mesoscopic element and considers the damage initiation threshold. To capture the nonlinear strength responses of the mesoscopic element at various chemical damage and confining pressures, a modified Mohr-Coulomb (M-C) criterion is introduced, in which the instantaneous friction angle and cohesion are expressed as functions of the confining pressure and chemical damage. The proposed model is validated and shows good agreement with experimental data.
 Result of this research shows that: (1) the porosity increases with increasing corrosion period and the increase rate (i.e., the slope of the porosity curve) is steep initially and then decreases gradually (see Fig. 1 (a)). (2) As shown in Fig. 1 (b), Young's modulus decrease with porosity growth. (3) The C-M coupled damage evolution curve is S-shaped and consists of four stages (see Fig. 1(c)), i.e., a linear elastic stage, a stable damage stage, a damage acceleration stage and a post-peak stage. In damage stage 1, stress is lower than the mechanical damage initiation threshold and the stress-strain curve is in a linear elastic state. At this stage, mechanical damage doesn’t initiate (i.e., ). Therefore, the total damage (Dcm) evolution curve is horizontal and only contains chemical damage (Dc=0.165) caused by carbonate dissolution. Once the axial strain exceeds the mechanical damage initiation threshold, the damage enters stage 2. In this stage, total damage (Dcm) begins to slightly rise and steadily increases with the increasing load. In damage stage 3, the damage-strain curve rises concave upward. After the peak strength point, damage development comes to stage 4, i.e., the post-peak stage.

Assessment of the Water Sorption Capacity of Rifaximin using Dynamic Vapor Sorption Technique for Optimization of the Choice of Excipients and Manufacturing Environment of Rifaximin Tablets.

Rifaximin, a medication of the rifamycin family with two distinct strengths of 200 mg and 550 mg in tablet form, is useful for the treatment of travelers' diarrhea. It has a solid yellow hue and is very hygroscopic in nature. It exhibits a variety of polymorphic forms such as α, β, γ, δ and ε depending on bonded moisture. These polymorphs' varying chemical and physical characteristics, such as solubility and water content, may have a big impact on in vivo absorption, which in turn affects efficacy and safety. Therefore, understanding the polymorphic stability of Rifaximin is crucial for formulating Rifaximin tablets. The current effort focuses on the understanding of water vapor sorption properties to control the polymorphic stability of rifaximin in the tablet formulation using the appropriate selection of excipients and manufacturing process. The dynamic vapor sorption method in the range of 0-90% relative humidity at 25 °C is used for understanding the sorption properties of drug substances and drug excipient mixtures; the state-of-the-art techniques of the X-ray diffraction method are used to identify polymorph conversions; and dissolution procedures are used for in-vitro correlation studies. The sorption study data reveals that Rifaximin is highly unstable at relative humidity conditions above 36%. When using excipients that have a low tendency to adsorb water in the formulation, the polymorphic results don't show any change in their intended form, and the in vitro dissolution data show an equivalency with the reference drug product. The study prompted a successful outcome-oriented development of the formulation processing environment conditions design to develop a test formulation that has adequate in vitro dissolution profiles, with the reference product showing the highest similarity and stability. The overall study explained here is useful for swiftly gaining insight into the sorption characteristics of Rifaximin, and it contributed to the widespread acceptance of Rifaximin Tablets as a treatment option.

Assay data of spent nuclear fuel: the lab-work behind the numbers

Computational modelling for spent nuclear fuel (SNF) characterization is already widely used and continuously further developed for a plethora of safety related applications and licensing issues in SNF management. An essential step in the development of these methodologies is the validation: the demonstration that the SNF elemental and isotopic composition is sufficiently accurately predicted by the code calculations. This validation step requires experimentally measured nuclide concentrations in SNF, together with an estimation of related uncertainties. The SFCOMPO 2.0 database of OECD/NEA is a database of such publicly available assay data of SNF. A basic understanding of all analytical steps that finally result in assay data of SNF is important for modelers when assessing the “fit-for-validation” requirement of an experimental dataset. The aim of this article is to explain users of such datasets the complex analytical pathway towards assay data. Points of attention, challenges and pitfalls all along the analytical pathway will be discussed, from sampling, dissolution procedures, necessary dilutions and separations, available analytical techniques, some related uncertainties, up to reporting of the results.

Study on phase transformation and reaction behavior of alumina extraction process by calcification of aluminum dross

The aluminum dross generated during the aluminum alloy processing and regeneration process contains a large amount of harmful highly reactive aluminum nitride and salts, which can cause environmental pollution. A novel method for preparing calcium aluminate by dry calcification of aluminum dross is proposed in this paper to extract valuable aluminum resources while achieving efficient detoxification. Detection methods such as XRD, XRF, and standard dissolution procedures have been applied to characterize the phase transition and reaction behavior of the aluminum extraction process. The results indicate that calcium additives can react with aluminum components in aluminum dross to generate 12CaO·7Al2O3 (C12A7), which is soluble in sodium carbonate solution, thereby separating it from other impurities. Under the optimal roasting conditions, the leaching rate of alumina is 87.89%, and the removal rate of nitrogen, chlorine, and soluble fluorine elements exceeds 99%.Excessive sodium carbonate is required to ensure that the hydrolysis product of C12A7 is calcium carbonate, avoiding the formation of hydrated calcium aluminate precipitates. The optimal leaching conditions are sodium carbonate concentration of 80 g L−1, caustic soda concentration of 5 g L−1, liquid-solid ratio of 8 mL g−1, and leaching time of 30 min. The leaching reaction of calcium aluminate conforms to the unreacted core model controlled by internal diffusion, and the apparent activation energy of the reaction is 18.05 kJ mol−1.

Implementation of Limited Liability Company Dissolution Reviewed from Law Number 40 of 2007 (Case Study At PT Sumber Berkat Jaya Hidup Baru- Batam City) ".

To anticipate the possibility of dissolving a PT, the legislators also include a number of provisions regarding conditions that must be met if a PT wants to be dissolved, must follow the dissolution procedure based on statutory provisions. The research method used is normative juridical, normative legal research which consists of a method based on the steps of discovering legal principles, legal systematics, and the level of legal synchronization that is being faced. The implementation of the dissolution of the Limited Liability Company is reviewed from Law Number 40 of 2007 concerning Limited Liability Companies. The dissolution of a Limited Liability Company requires stages according to the provisions of Law Number 40 of 2007 concerning Limited Liability Companies.

Dissolution of Ruthenium Metal by Combined Oxidizing and Reducing Action of Sodium Hypochlorite and HCl Solution

ABSTRACT Ruthenium (Ru) is an important platinum group metal for the manufacture of advanced materials owing to its chemical and physical properties. Generally, it is extremely difficult to dissolve Ru metal by using acidic solutions containing strong oxidizing agents. Therefore, pretreatments like alkali fusion roasting at high temperature are practiced to render the Ru metal soluble in aqueous solution. In this work, a simple procedure was proposed to dissolve Ru metal at room temperature without any pretreatments. The dissolution procedure consisted of two steps: (i) oxidation of Ru metal to RuO4 – by using pure NaClO solution; (ii) reduction of RuO4 – to stable Ru2OCl10 4– by using HCl as a reducing agent. The role of NaClO and HCl in the dissolution of Ru metal was discussed on the basis of the potential-pH diagram and the corresponding oxidation and reduction reactions. The effect of several parameters like the concentration of NaClO and HCl, temperature, time, and pulp density was investigated. Optimum conditions were obtained to completely dissolve Ru metal by using NaClO and HCl solution without alkali fusion.

Thoughts and Concepts in Ultrasonography-guided Hyaluronidase Injection Technique.

INTRODUCTION The number of people receiving facial filler injections for aesthetic purpose has been increasing in recent years. Simultaneously, the number of patients dissolving fillers due to unsatisfactory outcomes or adverse effects, such as granuloma and allergy, is also increasing. Hyaluronidase has various uses, including dissolving hyaluronic acid fillers and treating granulomatous foreign body reactions and necrosis associated with filler injections.1 Here, I will discuss why ultrasonography should be performed before a filler dissolving injection and why the filler should be dissolved while viewing ultrasonographic images.2 Hyaluronidase is an endoglycosidase that breaks down hyaluronic acid into monosaccharides by cleaving its glycosidic bonds.3,4 Safe performance of this method requires sufficient understanding of the anatomy of the face, because of the heavy distribution of vital blood vessels, nerves, retaining ligaments, and muscles.5 The author performed filler removal using ultrasonography on more than 500 patients. First, palpation was performed, and after confirming the exact location and depth with ultrasound, it was marked with a pen. The filler was removed by injection of hyaluronidase. Some people had swelling and heat due to allergy to hyaluronidase, but they improved within 2–3 days and did not experience any other side effects (Fig. 1). This ultrasonography-guided hyaluronidase injection technique offers several advantages, as follows:Fig 1.: Pre- and post-procedure ultrasonic images. A, Filler in the anterior cheek shown before hyaluronidase injection. B, Anterior cheek after the filler has been completely dissolved. Ultrasonography is rapid and simple, with no risk of radiation exposure. This technique involves no additional discomfort for patients and can be more comfortable. This method does not require injection into a wide area around the injected filler, indicating that a smaller amount of hyaluronidase can be used. Vital blood vessels and nerves can be avoided using ultrasonographic images. When catastrophic adverse effects (such as blindness or necrosis) occur, exacerbation of such adverse effects can be quickly and accurately prevented. This method can effectively dissolve the filler, as the target is accurately set beforehand. In cases wherein undissolved fillers are still present despite several dissolution procedures, ultrasonography-guided hyaluronidase injection before removing the filler by incision is a feasible approach for both the patient and the physician. A limitation is that it is very difficult to completely remove granuloma or filler if it remains in a very small size, or if the filler is broken into very small sizes by melting it. In addition, there are cases in which the filler cannot be confirmed by ultrasound. The use of more precise ultrasound is necessary. This study is a conceptual thought and represents the author’s opinion based on experience, and a more scientific study with 500 patients will be conducted in the future. DISCLOSURE The author has no financial interest to declare in relation to the content of this article.