Laboratory Performance Evaluation Research Articles

Evaluating laboratory performance in Dengue virus detection by using RT-qPCR: Analysis of a Brazilian external quality assessment program results

Evaluating laboratory performance in Dengue virus detection by using RT-qPCR: Analysis of a Brazilian external quality assessment program results

Evaluation of quality indicators in microbiology and infectious disease serology laboratory: A study from a tertiary cancer care centre in Gujarat, India

Introduction: Quality indicators (QIs) are important for the monitoring and evaluation of laboratory performance at pre-analytical, analytical, and post-analytical phases. Errors in the laboratory arise more frequently before and after the analysis of samples. The total testing process (TTP) therefore needs to be evaluated for good laboratory performance. A good quality indicator should give information about the performance of a process, thereby governing the quality of services.Objective: To analyse TTP and QIs for a period of six years of screening of laboratory performance.Methods: This retrospective analysis was conducted for the period 2017 to 2022. QIs at pre-analytical (12), analytical (04) and post-analytical (03) phases were defined and analysed on a monthly basis. The laboratory followed the guidelines of the International Organization for Standardization (ISO) 15189:2012 to identify errors in all sections.Results: A total of 259,694 samples were received during the study period. A total of 628,817 tests were performed. The overall error rate was 1.25/1000 tests. Error in the pre-analytic phase was 0.96/1000 tests, the commonest being haemolysed samples. Error in the analytical phase was 0.33/1000 tests. The error of postanalytical phase was 0.48/1000 tests with turn round time (TAT) outliers being the commonest.Conclusion: Amongst all phases of QIs, errors were minimum in the analytical phase. Continuous monitoring and analysis of QIs helps in identification of common errors in the laboratory. Corrective measures will help to improve quality of the laboratory services, and hence the patient outcome. Regular training, evaluation of technical staff, regular preventive maintenance and calibration of all analytical instruments helps in reducing the errors.

Evaluate laboratory performance pre- and post-COVID pandemic at Major Hospital in Sri Lanka- A case study

Evaluate laboratory performance pre- and post-COVID pandemic at Major Hospital in Sri Lanka- A case study

Laboratory and Field Performance Evaluation of Cracking of Airfield Warm Mix Asphalt with Reclaimed Asphalt Pavement at the National Airport Pavement and Materials Research Center

The U.S. Federal Aviation Administration is exploring initiatives to decrease transportation greenhouse gas emissions by developing carbon reduction strategies, including using low-embodied carbon materials, such as reclaimed asphalt pavement (RAP), in airport pavement construction. However, verifying RAP’s viability for airfield pavements with laboratory and field performance measures is essential. This study compared the cracking susceptibility of a P-401 hot mix asphalt and warm mix asphalt (WMA)+RAP airfield mixes using laboratory performance tests and conducted a preliminary evaluation of pavement responses from accelerated pavement testing (APT) fatigue tests. The observations and outcomes presented in this paper found that adding 20% of recycled materials with WMA additives had a decreasing impact in mix performance but did not overly affect the asphalt mix properties, as cracking properties from the different test procedures were found with comparable outcomes. Additional observations from strain gauges and temperature probes in the National Airport Pavement and Materials Research Center test cycle 2 APT fatigue test sections showed that the maximum tensile strains in the WMA surface lane 5 south section were consistently higher than those in the WMA+RAP lane 6 south section, which may be because of the higher load level that it was exposed. Additionally, the hardened or aged RAP binder in the entire lane 6 south section may have increased its stiffness, resulting in lower strain levels than in the lane 5 south section. Notably, both sections showed an increase in tensile strains with an increase in asphalt concrete temperature, which confirmed the temperature dependency behavior of asphalt concrete.

Efficiency assessment of variable speed air source heat pump heating systems: A hybrid data-driven and theoretical approach

The laboratory performance evaluations of variable speed air source heat pumps typically adhere to standard steady-state test methods, which neglect the dynamic characteristics associated with actual operation. The evaluation of energy efficiency influencing factors in the actual installed project is crucial for guiding improvements in energy efficiency. The aim of this paper is to identify any loss of dynamic operation, a hybrid approach combining data-driven and theoretical methodologies for modeling and assessing the efficiency of variable speed air source heat pump heating systems based on operation state decomposition. The innovation of this study lies in the abandonment of the previous method for constructing performance maps based on compressor speeds, and instead adopting the concept of thermodynamic perfectibility is introduced to characterize the steady-state performance, serving as a benchmark for identifying operational losses including unsteady-state operation loss, stand-by loss, and defrosting loss based on the actual operating state of the variable speed air source heat pumps. The findings from six monitoring projects indicate that the failure to consider crucial dynamic characteristics can lead to deviations of 4.7%–36.5% from actual performance. These deviations can be attributed to various factors, including a loss of up to 27.2% due to unsteady operation, a standby loss of up to 7.9%, and an unnecessary defrosting operation resulting in a defrosting loss of up to 8.9%.

Monitoring SARS-CoV-2 genetic variability: A post-market surveillance workflow for combined bioinformatic and laboratory evaluation of commercial RT-PCR assay performance.

The speed at which Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is mutating has made it necessary to frequently assess how these genomic changes impact the performance of diagnostic real-time polymerase chain reaction (RT-PCR) assays. Herein, we describe a generic three-step workflow to assess the effect of genomic mutations on inclusivity and sensitivity of RT-PCR assays. Sequences collected from the Global Initiative on Sharing All Influenza Data (GISAID) were mapped to a SARS-CoV-2 reference genome to evaluate the position and prevalence of mismatches in the oligonucleotide-binding sites of the QIAstat-Dx, an RT-PCR panel designed to detect SARS-CoV-2. The frequency of mutations and their impact on melting temperature were assessed, and sequences flagged by risk-based criteria were examined in vitro. Out of 8,900,393 SARS-CoV-2 genome sequences analyzed, only 173 (0.0019%) genomes contained potentially critical mutations for the QIAstat-Dx; follow-up in-vitro testing confirmed no impact on the assays' performance. The current study demonstrates that SARS-CoV-2 genetic variants do not affect the performance of the QIAstat-Dx device. It is recommended that manufacturers incorporate this workflow into obligatory post-marketing surveillance activities, as this approach could potentially enhance genetic monitoring of their product.

Study on the preparation and mechanical and fatigue properties of alkali excited recycled concrete

This study aims to explore the preparation process of alkali excited recycled concrete, and evaluate its performance in terms of mechanical and fatigue properties, so as to provide theoretical and practical support for the application of sustainable development and environmental protection building materials. Laboratory test and performance evaluation were used to prepare alkali-stimulated recycled concrete specimens with different proportions by adjusting fly ash, alkali activator and water solid ratio in recycled concrete. Then, the mechanical properties of the specimen were tested, including the influence of the cementing material on its compressive strength and the influence of the aggregate quality on its compressive strength. Finally, the fatigue life test is used to analyze the fatigue performance of alkali stimulated recycled concrete, and the influence of different ages and different stress levels on fatigue damage performance of alkali stimulated recycled concrete specimens is studied. The experimental results show that the mechanical properties of recycled concrete can be significantly improved by using alkali excited recycled concrete preparation technology. It is found that under the same stress ratio, with the increase of age, the corresponding fatigue life will increase, the flexural tensile strength will increase, and the fatigue resistance will improve. At the same age, the fatigue life of specimens decreases with the increase of stress ratio, and the flexural tensile strength and fatigue resistance remain unchanged. This study proves the effectiveness of alkali excited recycled concrete preparation technology in improving the mechanical properties and fatigue properties of recycled concrete. Alkali stimulated recycled concrete is not only conducive to resource reuse, reduce the impact of waste on the environment, but also provides a new choice for the sustainable development of building materials. However, further research and application are needed to promote the widespread application of alkali excited recycled concrete in engineering practice.

Laboratory performance evaluation of porous asphalt mixture containing recycled concrete aggregate and fly ash

This study performed laboratory experiments to evaluate the performance of porous asphalt mixtures (PAMs) containing recycled concrete aggregate (RCA). One open aggregate gradation with Class C fly ash as the filler, granite aggregate, two binder types (PG 67–22 and PG 76–22), and four RCA contents (0%, 10%, 20%, and 30% by mass of aggregates in the sieve size range of 4.75 to 9.5 mm) were included in the experiments. The mixture properties evaluated include permeability and air-void content, Marshall stability and flow, indirect tensile strength, moisture susceptibility, Cantabro abrasion loss, macrotexture, and sound absorption coefficient. The study found that using a blend of granite and RCA in a PAM led to better performance in terms of indirect tensile strength, stiffness, moisture resistance, and resistance to raveling. This was particularly confirmed for PAMs with an unmodified PG 67–22 binder. The mixture that contained 30% RCA performed the most satisfactorily, with an indirect tensile strength of 0.81 MPa and a Marshall stability of 23 kN at 25 °C. These values were 37.5% and 15%, respectively, higher than the control mixture. Based on these results, the study recommends the use of 30% RCA in PAMs for the friction course of a highway pavement or the porous surface of a porous pavement.

Laboratory Characteristics, Performance Evaluation, and Agency Cost Analysis of Cold-Recycled Asphalt Mixtures

Laboratory Characteristics, Performance Evaluation, and Agency Cost Analysis of Cold-Recycled Asphalt Mixtures

Preanalitik Hataların Altı Sigma Metodu ve Pareto Prensibi Analizi ile Değerlendirilmesi

Aim: In this study, we aimed to evaluate the preanalytical errors over a five year period using the Six Sigma methodology and Pareto Principle in the clinical biochemistry laboratory. Methods: Five-year sample rejection data between January 2015 and December 2019 in the clinical biochemistry laboratory were analyzed and classified according to the reasons for rejection. Six Sigma levels for the total and each preanalytical error were calculated with Westgard online formula. Preanalytical errors were evaluated according to their frequencies ranks and percentages with Pareto's principle. Results: The overall rate of five-year total critical preanalytical errors was 1.91% and the sigma level was 3.6. According to Pareto's chart, the three most common errors among the five-year preanalytical rejections were clotted sample (42.49%, sigma value:4), insufficient sample (23.53%, sigma value:4.2), and wrong container (8.01%, sigma value:4.5). Conclusion: Six Sigma is a quality management methodology used to evaluate laboratory performance processes according to universal quality criteria. Calculated sigma values of preanalytical errors in our laboratory were within the acceptable range. However, planned regulatory activities for frequently observed preanalytical errors should be a laboratory management strategy to reduce these error rates and improve our laboratory performance.

Chinese expert consensus on D-dimer laboratory testing and clinical application

D-dimer is a degradation product deriving from the plasmin-mediated degradation of cross-linked fibrin. It serves as a biomarker for the activation of coagulation and fibrinolysis, and has been extensively utilized in the diagnosis and treatment of various diseases. However, in recent years, issues related to D-dimer laboratory testing and its clinical application have become increasingly prominent. The lack of standardization in reports has led to confusion in both laboratory testing and clinical application. To address this, the Chinese Society on Thrombosis and Hemostasis brought together experts in the field of thrombosis and hemostasis in China to discuss and develop the 'Chinese Expert Consensus on D-Dimer Laboratory Testing and Clinical Application'. This consensus focuses on laboratory testing methods, quality requirements, performance evaluation, sample processing, analysis interference, result reports, and clinical application of D-dimer. Its aim is to optimize the key issues related to D-dimer testing in laboratories and provide guidance for the appropriate use and accurate interpretation of D-dimer in clinical settings.

Laboratory proportion design and performance evaluation of Fiber-Reinforced rubber asphalt chip seal based on multiple properties enhancement

Chip seal is an effective preventive maintenance technology for the pavement distress repair and pavement service life extension. Adding fiber or rubber powder alone has been shown to improve chip seal performance. However, the full potential of chip seal could not be attained by utilizing only fiber or rubber powder singularly. In this study, a fiber-reinforced rubber asphalt chip seal was prepared and evaluated based on multiple properties enhancement. Analysis of Variance (ANOVA) was conducted to assess the level of significant influence of rubber powder content and shearing time on the results of the penetration, softening point, ductility, and elastic recovery tests. The optimal process parameters for rubber asphalt were further analyzed and determined based on the ANOVA results. Bending beam rheometer (BBR) and rotational viscosity tests were executed to evaluate the low-temperature crack resistance and workability of the rubber asphalt. Cover, sweep, 45-degree skew shear and texture depth tests were performed to identify the optimum proportion of fiber-reinforced rubber asphalt chip seal. Tensile, temperature stability, water stability and three-point bending tests were conducted to evaluate chip seal performance. Cost analysis for mature preventive maintenance technology was carried out to evaluate equivalent annual costs. The results show that essential parameters for preparing rubber asphalt were the rubber powder content of 22.5% and the shearing time of 60 min. Moreover, the optimum proportion of fiber-reinforced rubber asphalt chip seal was determined to be 9.55 kg/m2 of aggregates, 2.3 kg/m2 of rubber asphalt, and 80 g/m2 of fiber. This study also confirmed that the fiber-reinforced rubber asphalt chip seal outperformed the rubber asphalt chip seal in terms of crack resistance, skid resistance, bonding performance, temperature stability, water stability and fatigue resistance. Combined with cost analysis, it was found that the fiber-reinforced rubber asphalt chip seal was a type of cost-effective preventive maintenance technology.

PRELIMINARY RESULTS FROM GLASGOW INTERNATIONAL RADIOCARBON INTERCOMPARISON

ABSTRACT GIRI (Glasgow International Radiocarbon Intercomparison) was designed to meet a number of objectives, including to provide an independent assessment of the analytical quality of the laboratory/measurement and an opportunity for a laboratory to participate and improve (if needed). The principles in the design of GIRI were to provide the following: (a) a series of unrelated individual samples, spanning the dating age range, (b) linked samples to earlier intercomparisons to allow traceability, (c) known age samples, to allow independent accuracy checks, (d) a small number of duplicates, to allow independent estimation of laboratory uncertainty, and (e) two categories of samples—bulk and individual—to support laboratory investigation of variability. All of the GIRI samples are natural (wood, peat, and grain), some are known age, and overall their age spans approx. >40,000 years BP to modern. The complete list of sample materials includes humic acid, whalebone, grain, single ring dendro-dated samples, dendro-dated wood samples spanning a number of rings (e.g., 10 rings), background and near background samples of bone and wood. We present an overview of the results received and preliminary consensus values for the samples supporting a more in-depth evaluation of laboratory performance and variability.

Laboratory performance evaluation of waste tire rubber (WTR) and ethylene-vinyl acetate (EVA)-modified asphalt mixtures

ABSTRACT This paper aims to explore the performance and economy of asphalt mixture with waste tire rubber (WTR)/ethylene-vinyl acetate (EVA) compound-modified asphalt. In this paper, five kinds of WTR/EVA asphalt mixture were selected as research targets, 70# base asphalt mixture and 5% styrene–butadiene–styrene (SBS) asphalt mixture were compared. Laboratory test results showed that WTR and EVA could significantly improve the performance of the asphalt mixture. The rutting resistance and anti-ageing ability of 15%WTR + 4%EVA asphalt mixture were superior to the 5% SBS asphalt mixture, and the anti-cracking ability and water stability were extremely close between them. Furthermore, the analysis of variance results revealed that WTR and EVA had a significant effect on asphalt mixture performance, the effect of EVA was more obvious than WTR. According to the economy analysis, the application of WTR/EVA-modified asphalt could significantly reduce construction costs, the material cost of 15%WTR + 4%EVA asphalt mixture was about 9.3% lower than 5% SBS asphalt mixture. As summarised above, WTR/EVA compound-modified asphalt mixture was an economical and environmentally pavement construction material due to its superior performance and lower cost, and 15%WTR + 4%EVA was the optimal combination dosage for asphalt mixture.

Infrared Thermographs- Methods for Evaluating Laboratory Performance

Infrared Thermographs- Methods for Evaluating Laboratory Performance

Structure, Process and Outcome Evaluation of Central Public Health Laboratory Performance About Neonatal Screening Program in Karbala in 2022

Background: Neonatal screening is a preventive medical act aims to early detecting neonates affected by specific disorders that endanger their lives or cause long-term health problems and require prompt intervention. This can result in significant reductions in morbidity, death, and related costs and disabilities. The panel of neonatal screened disorders has been gradually expanded. Expansion has been empowered with the introduction of tandem mass spectrometry, which allowed for the screening of up to 40

Laboratory Performance Evaluation of Alternative Approaches to Incorporate Recycled Binder Availability into Mixture Design Procedures

There is currently uncertainty in how to properly account for partial recycled binder availability within asphalt mixture design procedures so that content of recycled asphalt materials (RAM) can be maximized while still achieving good performance. This study evaluates and compares two alternative approaches to consider partial availability in mixture design: availability adjusted mix design (AAMD) and corrected optimum asphalt content (COAC). The AAMD method revises the calculation of volumetric properties by considering unavailable binder as part of the bulk aggregate volume and uses the RAM gradation to design the aggregate structure. In the COAC method, a mixture is first designed following the conventional Superpave procedures and then a specified increase to the virgin asphalt content is made. Two “control” mixtures containing RAM are evaluated that were originally designed according to the standard Superpave method. Alternative designs were prepared according to the COAC and AAMD methods while maintaining the RAM content in the respective control mixture. Baseline virgin mixtures and one mixture designed following the AAMD method with higher reclaimed asphalt pavement (RAP) content were also prepared. The cracking and rutting performance of the resultant mixtures was evaluated. The results show that the AAMD and COAC approaches lead to an improved cracking performance compared with the control mixtures even for the mixture designed with AAMD at a higher RAP content. However, the mixture designs prepared according to the COAC method presented increased rutting whereas the AAMD mixtures remained at the same level as their respective control mixture.

Laboratory Performance and Compositional Evaluation of Bio-Based Recycling Agents

This study sought to evaluate the chemical composition of bio-based recycling agents (RAs) as indicated by fatty acids content and their impacts on the rheological properties of virgin and recycled asphalt binders. The study consisted of two phases: Phase 1 evaluated five bio-based RAs using gas chromatography/mass spectrometry (GC/MS) and measured binder properties at low temperatures with a bending beam rheometer (BBR). Based on the collected results, two bio-based RAs were selected for evaluation in Phase 2. Phase 2 verified through rheological (BBR and dynamic shear rheometer) and chemical (gel permeation chromatography and Fourier transform infrared spectroscopy) characterization of the effectiveness of the two selected RAs in improving the performance properties of recycled asphalt binders’ blends. Considering that the overall stability of the fatty acids of a recycling agent blended with an asphalt binder is governed by physicochemical factors related to the state of dispersion of the molecular microstructure rather than the inherent reactivity of the molecular components with oxygen, a fatty acid index (i.e., Δfatty acids) was proposed. Based on the results of this research, the Δfatty acids index was found effective in evaluating the oxidation stability of RAs with different chemical compositions and in screening their impacts on the rheological and chemical properties of recycled asphalt binders.

Examination of discordant external quality assessment scheme results

An external quality assessment scheme (EQAS) is a form of external quality assurance that provides evaluation of laboratory performance based on the analysis of a collection of samples supplied by an external agency. EQAS performance has been shown to reflect the quality of patient specimen testing in a clinical laboratory.

Laboratory Performance Evaluation of Asphalt-Treated Cold Recycled Mixtures Using Existing Practical Tests

Agencies currently utilize several proxy tests, related to level of compaction (density) and moisture content, to assess the quality of a recycled pavement during construction. These proxy tests are not completely able to indicate sufficient quality or stability of recycled pavements under trafficking or surfacing, especially at early ages. The lack of sound and rapid tests for use in process control and acceptance during construction limits the use of the recycling techniques by agencies, therefore they do not fully benefit from the advantages that pavement recycling offers. This study evaluates the viability of currently available simple and practical stiffness tests (i.e., soil stiffness gauge and light weight deflectometer tests), deformation resistance tests (i.e., Marshall hammer test), and penetration resistance tests (i.e., dynamic cone penetration test) to characterize the properties of asphalt-treated cold recycled mixtures. The scope of the work included laboratory testing of 18 different cold recycled mixtures, prepared through different processes combining different binding agents and filler types, at different curing times via the selected tests. The collected data were analyzed to evaluate these tests in relation to their repeatability characteristics and versatility to capture the performance of recycled materials with respect to changes in curing time, type of stabilizing/recycling agent, and presence of active filler. The data obtained showed the ability of these tests to capture the effect of curing. Moreover, these tests were found to be sensitive to changes in the recycling agent type, recycling agent content, and presence of active filler.