Analytical Procedure For Evaluation Research Articles

Recommendations on Describing the Requirements for Microbiological Quality and Sterility of Medicinal Products

The paper presents recommendations on describing analytical procedures for evaluation of medicinal products in terms of sterility and microbiological quality in accordance with the State Pharmacopoeia of the Russian Federation and the Pharmacopoeia of the EAEU. These quality attributes should be covered in Product specification files for any medicinal product. The paper describes specific considerations for preparation of the corresponding sections of the Russian or EAEU Product specification files. It is necessary to provide and justify quality requirements, refer to or describe the recommended analytical procedure and indicate differences, if any, from the standard one. Standardisation of the approach to microbiological quality control of medicinal products will allow analysts to accurately perform the tests, get reliable results and ensure the safety of medicinal products.

Sigma and Risk in the Quality Control Routine: Analysis in Chilean Clinical Laboratories.

The Six Sigma methodology is focused toward improvement, based on the Total Quality Management. It has been implemented in analytical procedures for clinical laboratories in the form of Sigma Metrics. This method is used in the evaluation of analytical procedures, providing evidence for risk-based management. A descriptive study was carried using data from 18 Chilean clinical laboratories. The information of their performance and quality specifications used in their routine work was obtained from UNITY, an internal quality comparison program. A total of 3461 sigma evaluations was gathered, mostly from biyearly controls. The general distribution shows a median of 5.5 with positive asymmetry similar to other publications. The reported quality specifications are based in CLIA for 51.2% of the cases, 30.2% from biological variation, and 10.7% from other programs for the external quality evaluation. Significant differences (P < 0.05) were found between medians against their specification source. In the studied series, it would be feasible to implement a risk-based quality control system with simple rules and minimal control materials for 55.5% of the evaluated sigmas. 19.6% of the sigmas require improvement mainly in precision. The variety in specifications reveals a lack of harmonization in the specification's selections.

Quick Evaluation Method for Defect Exceeding the Allowable Flaw Size in Pressure Vessel of Nuclear Reactor for Power Plant and Space Heating

Nuclear power can be used for power generation, space heating, and other fields, producing a limited level of greenhouse gases and no atmospheric pollutants. However, the safety of nuclear reactors is always a public concern. The reactor pressure vessels (RPVs) play an important role in the safe operation of a nuclear power plant. When a defect is inspected in the RPV, complex analytical evaluation procedures, including fatigue analysis and fracture assessment, are necessary to ensure the structural integrity of the defective component. Based on the RSE-M, a quick evaluation approach for RPVs with defects exceeding acceptance standards is proposed in this work to reduce the computational complexity and analysis time. The flaw evaluation is simplified by adjusting the inspection period based on the analysis of fatigue crack growth. The new method was applied to the RPVs with embedded defects and underclad semi-elliptical defects, respectively. The proposed evaluation approach was verified by the case of a typical RPV cylinder containing an embedded crack, where all possible transients during the operation of nuclear power plants are considered. During the allowable residual life obtained of 5-years, failure would not occur in the defective component via the conventional method, which gives confidence to the availability of the new approach. Consequently, the proposed method can be a valid reference for the structural integrity assessment of nuclear reactor components with defects exceeding acceptance standards.

Occurrence, distribution, and risk of organochlorine pesticides in food and greenness assessment of method.

Organochlorine pesticides (OCPs) have been used globally to boost food production. Although banned, due to their prolonged toxic effects but their residue still impacts the quality of primary and processed agricultural products. This study assesses the levels of residual OCPs (α,β,δ-HCH, heptachlor, heptachlor epoxide, chlordane, methoxychlor, aldrin, dieldrin, endrin, endrin aldehyde, endrin ketone, endosulfan, endosulfan sulfate, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), and 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT)) in food commonly consumed in Lagos and Ibadan, Southwest, Nigeria. Health risk associated with human exposure via food intake was evaluated with a statistical predictive model. About 248 composite food samples from 8 categories were analyzed in Lagos and Ibadan. Sampleextraction and clean-up were by QueChERS method andextracts injected into GC-μECD. ƩDDT concentration was highest in meat products, aquatic foods, dairy products, edible oils, fruits, and cereals, while ƩHCHs were highest in chicken eggs and vegetables. ƩOCP concentrations (ng/g) in food categories were 6.09±1.6-6.85±0.9 (meat), 5.29±2.0-12.3±14 (aquatic foods), 4.86±1.7-5.89±0.8 (dairy products), 4.53±0.8-6.32±1.1 (edible oils), 3.32±1.3 (eggs), 3.54±1.0-4.80±1.5 (fruits), 4.16±2.7-4.40±0.8 (vegetables), and 6.12±2.0-6.62±0.9 (cereals). The estimated average daily intake of OCPs was 5.91, 12.5, 4.41, 6.40, 1.53, 5.14, 3.95, and 16.7 ng/kg bw/day through the consumption of meat products, aquatic foods, dairy products, edible oils, chicken eggs, fruits, vegetables, and cereals, respectively. The health risk of residual OCPs via ingestion of foods considered in this study was <1, which implied no potential health risk at the current consumption rate. However, regular monitoring of OCPs residues in food is highly recommended. Finally, the method scaled the analytical Eco-Scale evaluation and Green Analytical Chemical Procedure Index as "an acceptable green analysis method."

Experimental and Calculation Studies of Main Line Oil Pumps Efficiency Change Due to Smooth Coatings

The study is dedicated to investigation of impact made by smooth coatings applied on the flow part surfaces of main line oil pumps with reference to energy efficiency performance of the said pumps. Loctite 7227 and Belzona 1341 were used as coatings which allowed to significantly reduce the roughness of the coated surfaces. Distinctive features of the abovementioned coatings are low cost and easy application (by spraying or using a brush) which is, despite lack of hydrophobic behavior, makes them applicable for use in operating conditions at oil pumping stations. Experimental studies have been carried out including coatings testing on full-scale pumps MOL 1250-60 and MOL 10000-210. The results of the experimental studies have been compared with the results of analytic calculations. Based on the results of the studies the applicability of smooth non-hydrophobic coatings was confirmed on condition of their application on the surfaces of volute flow parts of mainline oil pumps. Besides, the suggested analytical procedure for coatings efficiency evaluation was validated.

ASSESSING THE QUALITY OF HOMOGENEITY OF PET FOOD USING FERROMAGNETIC MICROTRACERS

Obtaining highly homogeneous mixtures is an urgent task in many areas of feed production, as it is associated with the need for even distribution of particularly important and valuable components. Manufacturers of animal feed are using several different methods for performing homogeneity studies to check their mixer performance. This paper is devoted to the use of nontraditional markers such as ferromagnetic Microtracers to evaluate the homogeneity of the final feed. Microtracers have successfully been used in a mixer testing program in the USA since 1985 and in Europe since 2006. They represent a major improvement over traditional analytical procedures for evaluation of mixer performance involving the use of cobalt or manganese salts. The authors described the quantitative results of determination and identification of Microtracers in two sets of 20 samples of pet food manufactured by Kormotech LLC with using a proprietary Rotary Detector procedure developed by Micro-Tracers Inc (San Francisco, California). It was shown that analysis of 150 g samples at level of Microtracer addition of 20 g per metric ton of pet food allowed a magnetic retrieval of the number of ferromagnetic particles from 61 to 101 which was sufficient for application of Poisson and Chi-squared statistics. The obtained results from two tests performed with different time of mixing were interpreted in accordance with the requirements of the GMP + BA2 standard. It was determined that mixing within 3 min leads to the marginal mixing with the calculated probability value of 1.12%. The prolonged mixing within 4 min leads to complete mixing with the calculated probability value of 5.93%. The use of ferromagnetic Microtracers in a mixer testing program is justified for such tasks as comparison of mixers with each other, as well as identifying the changes in the technical characteristics of the mixers and their performance occurring during their exploitation. In addition, using microtracers can quickly determine the quality of the mixing equipment when it is purchased.

Levels of polybrominated diphenyl ethers (PBDEs) in indoor dusts in Lagos and Ibadan, Nigeria

Polybrominated diphenyl ethers (PBDEs) were analysed in dust samples collected from 10 homes, 10 cars, 10 offices and 10 schools in 2 different cities, Lagos and Ibadan, Nigeria. The daily dust ingestion was calculated for all the indoor microenvironment studied. Extraction of PBDEs was by ultrasonication and was analysed on a gas chromatography microelectron capture detector. This represents the first PBDE study in school dust on the African continent and also first PBDE study in Ibadan. Lagos is Africa’s most populated city and Ibadan is the third largest city in West Africa and of historical significance. The concentrations of ΣPBDEs (BDE 28, 47, 99,100,153,154,183 and 209) in homes, cars, offices and schools was 2.24–11500 ng/g; 1.20–258 ng/g; 3.76–687 ng/g and 0–471 ng/g, respectively. Generally, dust samples from Lagos had higher median concentration as compared to Ibadan. BDE-47, BDE-99 and BDE-183 were the most prominent congeners recorded. Interestingly, BDE-209 which is prevalent in dust samples in temperate region had a low concentration in this study (especially in car dust). This may be attributed to the photodegradation of BDE-209 due to Nigeria being a tropical country. samples in Lagos, very high median concentration levels of PBDE was present in-house dusts, with slightly lower PBDE levels recorded in office dust. BDE-100 and BDE-183 were the most prevalent congeners in school dust samples. The median concentration obtained was lower when compared to Australian schools. The concentrations of PBDE in house and office dusts in Nigeria was less than studies in the UK and US but similar to values from South Africa and Egypt. The daily intake of PBDEs from all indoor dust samples were below USEPA reference dose (RfD) for oral exposure for all BDE congeners. For all indoor dust categories, toddlers had the possibility for the highest ingestion rate, and this is of serious concern. Lastly, the method scaled analytical Eco-Scale evaluation and Green Analytical Chemical Procedure Index as “an acceptable green analysis method”.

Optimization of Methods for Determination of the Encapsulation Efficiency of Doxorubicin in the Nanoparticles Based on Poly(lactic-co-glycolic acid) (PLGA)

Introduction . Drug encapsulation efficiency (EE) is the important parameter of the nanoparticle-based drug formulations. Generally, the methods for evaluation of the EE are based on separation of the free and NP-bound fractions of the drug; however, applicability of these methods for a particulate formulation needs careful consideration. Aim. The purpose of the study was to optimize the procedure for evaluation of the EE for a nanoparticle-based drug formulation taking doxorubicin loaded in the PLGA nanoparticles (PLGA-Dox NP) as a model formulation. Materials and methods. The PLGA-Dox NP were prepared by a “double emulsion” method at pH of the external aqueous phase of 7.4 or 6.4. The NP size and size distribution (PDI) were determined by photon correlation spectroscopy (PCS) and transmission electron microscopy (TEM). For the EE evaluation of doxorubicin, the NP were separated by centrifugation (CF), ultrafiltration (UF), or gel filtration. The efficiency of NP separation by the CF method was evaluated by the PLGA content in the supernatant by capillary electrophoresis (CZE). Results and discussion. The average hydrodynamic diameter of the PLGA-Dox/7.4 and PLGA-Dox/6.4 NP (FCS) was 103 ± 10 nm and 141 ± 8 nm, respectively. According to the TEM data, the main fraction of the NP averaged 50 ± 16 nm. The EE of doxorubicin, determined after the NP separation by centrifugation at 48254.g, was 78.9 ± 1.8 % for the PLGA-Dox/6.4 and 91.5 ± 0.9 % for the PLGA-Dox/7.4 NP with the residual PLGA content in the supernatant of ~5 %. At lower acceleration the NP separation was incomplete leading to underestimation of the EE. Also, the ultrafiltration method using the filters with the NMWL of 50 and 100 kDa enabled the reliable NP separation with the minimal doxorubicin adsorption on the filter (<4 %). Separation of the NP by gel filtration led to the underestimation of the EE due to considerable desorption of doxorubicin from the NP surface. Conclusion. The optimal analytical procedures for evaluation of the EE of doxorubicin in the PLGA NP are based on the NP separation by CF at 48254×g and UF using filters with NMWL of 50 and 100 kDa.

Reliability of standard methods for evaluating the early-age cracking risk of thermal-shrinkage origin in concrete walls

The paper is focused on the reliability of existing guidelines for both the design and evaluation of early-age cracking risk in concrete structures. The study considers the recommendations for reinforced concrete tank walls and bridge abutments, which are especially prone to early-age cracking. A thorough review and discussion of the American, European and Japanese guidelines are supplemented by the analytical procedure for simple evaluation of thermal loads and more precisely considering shrinkage strains. The results obtained using the guidelines were compared with actual observations of crack width in tank walls and bridge abutments. An example of using standards in wall design is also presented. Finally, the usefulness of the presented methods is highlighted with suggestions for a possible path for considering early-age thermal and shrinkage effects in reinforced concrete wall structures.

Investigation of analytical evaluation procedure for fracture of steel containment vessel subjected to internal pressure using damage mechanics model

Investigation of analytical evaluation procedure for fracture of steel containment vessel subjected to internal pressure using damage mechanics model

A simplified non-linear structural analysis of reinforced concrete frames with masonry infill subjected to seismic loading

Structural performance of both new and existing building structures under seismic actions can be assessed with a wide range of nonlinear static procedures and time history dynamic analysis available in literature. Most of these procedures, such as time history dynamic analysis, are complex as they require sophisticated finite element modelling. Reinforced concrete (RC) frames with masonry infill, for example, pose great challenge in modelling both the composite material behaviour and their interactions. With significant effort directed towards sustainable infrastructure development, a simplified nonlinear analytical procedure for evaluation of RC infill frames subjected to incremental horizontal loading is developed that can be used easily in integrated structural performance and sustainability evaluation. The method, developed on the premise of truss analogy and utilising the pushover analysis, assumes that all structural members of the RC frame are truss elements with homogeneous material properties derived on the basis of a pure axially loaded system and the infill masonry is converted into strut elements. Stiffness modification through evaluation of nonlinear stress-strain states is employed to generate the overall force-deformation behaviour of the structural system. Experimental data available in literature is used to validate the procedure.

Harmonização de metodologias de análise da própolis

Propolis (bee glue) is a resinous bee hive product used by man since ancient times due to its pharmaceutical properties. The variability of its chemical composition, linked with the floral origin, requires the analysis of several quality parameters. Nevertheless, at the European level, in addition to the inexistence of legal requirements for quality control, there is also a lack of analytical procedures, despite the presence in the literature of several methodologies, which are often not comparable. The International Honey Commission, an worldwide network aiming to implement and develop new analytical methods for the control bee products and the establishment of quality standards, defined as a priority, within the propolis working group, the harmonization of analytical procedures for propolis quality evaluation, particularly in respect to ash, wax (using two alternative methods), balsamic content after extraction with ultrasonic or mechanical agitation as well as the analysis of its phenolic composition through the assessment of total phenolics, flavones/flavonols and flavanones/di-hydroflavonols. This collaborative study was engaged by 15 entities, including 14 laboratories and an international company working with propolis. According to the results obtained in our laboratory it is possible to draw a first evaluation on the applied methods, in particular the simplicity on the protocol implementation, with exception for the wax content, which proved to be laborious and non-adapted for routine analysis. Nevertheless, the wax values from both methodologies seems to agree, independently of its level in the samples. For the extraction procedure (balsamic content), the samples showed values between 43% and 70%, independent of the use of mechanical stirring or sonication, which shows the advantage of this second method, which enables a significant reduction in labor time, regardless of the absolute value. Overall, the results found for the tested protocols, for the different parameters, revealed a constant performance, besides de natural oscillation associated with the floral origin.

The co-feature ratio, a novel method for the measurement of chromatographic and signal selectivity in LC-MS-based metabolomics

Evaluation of analytical procedures, especially in regards to measuring chromatographic and signal selectivity, is highly challenging in untargeted metabolomics. The aim of this study was to suggest a new straightforward approach for a systematic examination of chromatographic and signal selectivity in LC-MS-based metabolomics.By calculating the ratio between each feature and its co-eluting features (the co-features), a measurement of the chromatographic selectivity (i.e. extent of co-elution) as well as the signal selectivity (e.g. amount of adduct formation) of each feature could be acquired, the co-feature ratio. This approach was used to examine possible differences in chromatographic and signal selectivity present in samples exposed to three different sample preparation procedures. The capability of the co-feature ratio was evaluated both in a classical targeted setting using isotope labelled standards as well as without standards in an untargeted setting.For the targeted analysis, several metabolites showed a skewed quantitative signal due to poor chromatographic selectivity and/or poor signal selectivity. Moreover, evaluation of the untargeted approach through multivariate analysis of the co-feature ratios demonstrated the possibility to screen for metabolites displaying poor chromatographic and/or signal selectivity characteristics. We conclude that the co-feature ratio can be a useful tool in the development and evaluation of analytical procedures in LC-MS-based metabolomics investigations. Increased selectivity through proper choice of analytical procedures may decrease the false positive and false negative discovery rate and thereby increase the validity of any metabolomic investigation.

Improvements in Article A-3000 of Appendix A for Calculation of Stress Intensity Factor in Section XI of the 2015 Edition of ASME Boiler and Pressure Vessel Code

Analytical evaluation procedures for determining the acceptability of flaws detected during in-service inspection of nuclear power plant components are provided in Section XI of the ASME Boiler and Pressure Vessel Code. Linear elastic fracture mechanics based evaluation procedures in ASME Section XI require calculation of the stress intensity factor. Article A-3000 of Appendix A in ASME Section XI prescribes a method to calculate the stress intensity factor for a surface or subsurface flaw by making use of the flaw location stress distribution obtained in the absence of the flaw. The 2015 Edition of ASME Section XI implements a number of significant improvements in Article A-3000. Major improvements include the implementation of an alternate method for calculation of the stress intensity factor for a surface flaw that makes explicit use of the Universal Weight Function Method and does not require a polynomial fit to the actual stress distribution and the inclusion of closed-form equations for stress intensity factor influence coefficients for cylinder geometries. With the inclusion of the explicit weight function approach and the closed-form relations for influence coefficients, the procedures of Appendix A for the calculation of stress intensity factors can be used more efficiently. A review of improvements that have been implemented in Article A-3000 of Appendix A in the 2015 Edition of ASME Section XI is provided in this paper. Example calculations are provided for illustration purpose.

Evaluation of Analytical Procedures in the Determination of Trace Metals in Heavy Crude Oils by Flame Atomic Absorption Spectrophotometry

In the present work, four trace metals, V, Ni, Cu and Fe, have been determined in five crude oil samples of Eastern Baghdad area, Iraq by flame atomic absorption spectrophotometry. The crude oils are characterized with API gravity values in the range, 25 - 15. The V/Ni ratios for the studied crudes were in the range 3.7 to 5.4 and indicated a typical of the sapropelic-type organic matter. The Ni and V contents were correlated with API gravity where an increase of metal contents with the decrease in the API values could be observed. The plots of V and Ni versus sulfur indicated linear correlation. This is attributed to the increase of porphyrinic structures of the metals. The method of direct dilution (DD) with organic solvent and the standard addition (SA) were evaluated as compared with standard dry ashing-acid dissolution (DA). In most cases the DD method gave V and Ni concentrations that are higher than DA and for the heavier crude oil (API = 15) the DD results were significantly smaller than those of the DA method. The SA method can be a good solution to determine the trace metals in heavy crude oils provided that the addition must not exceed the levels of the metal concentration in the diluted samples.

Effect of Rotation and Initial Magnetic Field in Fibre-Reinforced Anisotropic Elastic Media

In this work, we study an analytical procedure for evaluation of the displacement and stresses in fibre-reinforced anisotropic elastic media under effects of rotation and initial magnetic field, and due to the application of the rotation and initial magnetic field. Effects of rotation and initial magnetic field are analyzed theoretically and computed numerically. Numerical results have been given and illustrated graphically. Comparison was made with the results obtained in the presence of rotation and initial magnetic field in fibre-reinforced anisotropic and isotropic elastic media. The results indicate the effect of rotation and initial magnetic field.

Application of the Probabilistic Fatigue Evaluation of Flow-Induced Vibration for Hot-Leg Piping in Japan Sodium-Cooled Fast Reactor

The primary hot-leg piping system of the advanced sodium-cooled fast reactor under conceptual study in Japan (named Japan sodium-cooled fast reactor: JSFR) utilizes large-diameter and thin-walled pipes to ensure high coolant velocity, which inevitably leads to the occurrence of flow-induced vibration. Usually, the structural integrity of a piping system under flow-induced vibration is defined to be the maximum stress amplitude below the design fatigue limit. The present study tries to establish a reasonable methodology to estimate the high-cycle fatigue damage due to flow-induced vibration depending on its frequencies and the corresponding stress levels. An analytical procedure for probabilistic fatigue evaluation is developed and applied to the hot-leg piping system. The reasonability of the newly proposed methodology is confirmed from a test simulation.

Discussion on "Characterization of 1-3 piezoelectric polymer composites - a numerical and analytical evaluation procedure for thickness mode vibrations'' by C.V. Madhusudhana Rao, G. Prasad, Condensed Matter Physics, 2010, Vol. 13, No. 1, 13703

In the paper entitled "Characterization of 1-3 piezoelectric polymer composites - a numerical and analytical evaluation procedure for thickness mode vibrations", the dependence of the thickness electromechanical coupling coefficient on the aspect ratio of piezoceramic fibers is studied by finite element simulation for various volume fractions of piezoceramic fibers in a 1-3 composite. The accuracy of the results is questionable because the boundary condition claiming that `predefined displacements are applied perpendicularly on $C^+$ plane on all nodes' is not suitable for the analysis of 1-3 composite with comparatively large aspect ratio from 0.2 to 1. A discussion regarding this problem and the suggested corrections are presented in this paper.

Technical Basis for Application of Weight Function Method for Calculation of Stress Intensity Factor for Surface Flaws Proposed for ASME Section XI Appendix A

Analytical evaluation procedures for determining the acceptability of flaws detected during in-service inspection of nuclear power plant components are provided in Section XI of the ASME Boiler and Pressure Vessel Code. Linear elastic fracture mechanics based evaluation procedures in ASME Section XI require calculation of the stress intensity factor. A method for calculating the stress intensity factor is provided in Appendix A of ASME Section XI. This method consists of a two-step process. In the first step, the stress distribution, as calculated in the absence of the flaw, is obtained at the flaw location. For a surface flaw, the stress distribution at the flaw location is then fitted to a third-order polynomial equation. In the second step, the fitted polynomial representation of the stress distribution is used with standardized influence coefficients to calculate the stress intensity factor. An alternate method for calculation of the stress intensity factor for a surface flaw that makes explicit use of the universal weight function method and does not require a polynomial fit to the actual stress distribution is proposed in this paper for implementation into Appendix A of ASME Section XI. Universal weight function coefficients are determined from standardized influence coefficients through closed-form equations. Closed-form equations for calculation of the stress intensity factor are provided. The technical basis and verification for this alternate method for calculation of the stress intensity factor are described in this paper.

Real‐time Reliability Evaluation with a General Wiener Process‐based Degradation Model

The aim of this paper is to investigate the issue of real‐time reliability evaluation based on a general Wiener process‐based degradation model. With its mathematical tractability, the Wiener process with a linear drift has been widely used in the literature, to characterize the dynamics of the degradation process or its transformation. However, the nonlinear degradation process, which can't be properly linearized, exists in practice. The dynamics of such a degradation process can't be accurately captured by linear models. Here, a general Wiener process‐based degradation model is proposed, which covers a variety of Wiener process‐based models as its limiting cases. A two‐stage method is presented to estimate the unknown parameters. Two real‐time reliability evaluation procedures are presented for different conditions: one is the analytical evaluation procedure, and the other is the simulated evaluation procedure. It is shown that when new degradation information is available, the evaluation results can be adaptively updated. Moreover, to check out the proposed degradation model, a graphical method is provided. Finally, the validity of the proposed evaluation method is illustrated by a numerical example and two real‐world examples. Copyright © 2013 John Wiley &amp; Sons, Ltd.