Quality Assurance And Quality Control Research Articles

Automated Detection and Classification of Pavement Distresses using 3D Pavement Surface Images and Deep Learning

Pavement distresses lead to pavement deterioration and failure. Accurate identification and classification of distresses helps agencies evaluate the condition of their pavement infrastructure and assists in decision-making processes on pavement maintenance and rehabilitation. The state of the art is automated pavement distress detection using vision-based methods. This study implements two deep learning techniques, Faster Region-based Convolutional Neural Networks (R-CNN) and You Only Look Once (YOLO) v3, for automated distress detection and classification of high resolution (1,800 × 1,200) three-dimensional (3D) asphalt and concrete pavement images. The training and validation dataset contained 625 images that included distresses manually annotated with bounding boxes representing the location and types of distresses and 798 no-distress images. Data augmentation was performed to enable more balanced representation of class labels and prevent overfitting. YOLO and Faster R-CNN achieved 89.8% and 89.6% accuracy respectively. Precision-recall curves were used to determine the average precision (AP), which is the area under the precision-recall curve. The AP values for YOLO and Faster R-CNN were 90.2% and 89.2% respectively, indicating strong performance for both models. Receiver operating characteristic (ROC) curves were also developed to determine the area under the curve, and the resulting area under the curve values of 0.96 for YOLO and 0.95 for Faster R-CNN also indicate robust performance. Finally, the models were evaluated by developing confusion matrices comparing our proposed model with manual quality assurance and quality control (QA/QC) results performed on automated pavement data. A very high level of match to manual QA/QC, namely 97.6% for YOLO and 96.9% for Faster R-CNN, suggest the proposed methodology has potential as a replacement for manual QA/QC.

Growing pains: An overview of cannabis quality control and quality assurance in Canada.

In the past decade, the predominant prohibition model for cannabis use has shifted towards a regulated legal model, most widely in the context of medical purposes. In 2018, Canada became the first G7 country to legalize cannabis for adult use, implementing a two-phase roll-out of cannabis regulations. A stated goal of the new legal framework is to minimize harms by providing a safe supply of cannabis to Canadian consumers. One way that this can be achieved is through appropriate Quality Control and Quality Assurance (QC/QA) measures. Canada has implemented stringent QC/QA measures for all classes of cannabis, which include requirements such as labelling THC and CBD content per product and limiting THC doses. This paper will provide an overview of the current QC/QA measures in Canada, highlighting differences based on class of cannabis and consider the strengths and weaknesses of the current standards. QC/QA standards represent a key safety feature that can enable informed purchasing and provide consumers with necessary information about various cannabis products. As Canada continues to progress its cannabis policies, QC/QA measures provide a key consideration for ensuring Canada meets its objective of providing a safe supply of cannabis to Canadian consumers.

Workshop report: Toward the development of a human whole stool reference material for metabolomic and metagenomic gut microbiome measurements

IntroductionTo date, there has been little effort to develop standards for metabolome-based gut microbiome measurements despite the significant efforts toward standard development for DNA-based microbiome measurements.ObjectivesThe National Institute of Standards and Technology (NIST), The BioCollective (TBC), and the North America Branch of the International Life Sciences Institute (ILSI North America) are collaborating to extend NIST’s efforts to develop a Human Whole Stool Reference Material for the purpose of method harmonization and eventual quality control.MethodsThe reference material will be rationally designed for adequate quality assurance and quality control (QA/QC) for underlying measurements in the study of the impact of diet and nutrition on functional aspects of the host gut microbiome and relationships of those functions to health. To identify which metabolites deserve priority in their value assignment, NIST, TBC, and ILSI North America jointly conducted a workshop on September 12, 2019 at the NIST campus in Gaithersburg, Maryland. The objective of the workshop was to identify metabolites for which evidence indicates relevance to health and disease and to decide on the appropriate course of action to develop a fit-for-purpose reference material.ResultsThis document represents the consensus opinions of workshop participants and co-authors of this manuscript, and provides additional supporting information. In addition to developing general criteria for metabolite selection and a preliminary list of proposed metabolites, this paper describes some of the strengths and limitations of this initiative given the current state of microbiome research.ConclusionsGiven the rapidly evolving nature of gut microbiome science and the current state of knowledge, an RM (as opposed to a CRM) measured for multiple metabolites is appropriate at this stage. As the science evolves, the RM can evolve to match the needs of the research community. Ultimately, the stool RM may exist in sequential versions. Beneficial to this evolution will be a clear line of communication between NIST and the stakeholder community to ensure alignment with current scientific understanding and community needs.

GO-SHIP Repeat Hydrography Nutrient Manual: The Precise and Accurate Determination of Dissolved Inorganic Nutrients in Seawater, Using Continuous Flow Analysis Methods

The GO-SHIP nutrient manual covers all aspects of nutrient analysis from basic sample collection and storage, specifically for Continuous Flow analysis using an Auto-Analyzer, and describes some specific nutrient methods for Nitrate, Nitrite, Silicate, Phosphate and Ammonium that are in use by many laboratories carrying out at-sea analysis and repeat hydrography sections across the world. The focus is on segmented flow analyzers not flow injection analyzers. It also covers laboratory best practices including quality control and quality assurance (QC/QA) procedures to obtain the best results, and suggests protocols for the use of reference materials (RM) and certified reference materials (CRMs).

GO-SHIP Repeat Hydrography Nutrient Manual: The Precise and Accurate Determination of Dissolved Inorganic Nutrients in Seawater, Using Continuous Flow Analysis Methods

The GO-SHIP nutrient manual covers all aspects of nutrient analysis from basic sample collection and storage, specifically for Continuous Flow analysis using an Auto-Analyzer, and describes some specific nutrient methods for Nitrate, Nitrite, Silicate, Phosphate and Ammonium that are in use by many laboratories carrying out at-sea analysis and repeat hydrography sections across the world. The focus is on segmented flow analyzers not flow injection analyzers. It also covers laboratory best practices including quality control and quality assurance (QC/QA) procedures to obtain the best results, and suggests protocols for the use of reference materials (RM) and certified reference materials (CRMs).

Methods Matter: Methods for Sampling Microplastic and Other Anthropogenic Particles and Their Implications for Monitoring and Ecological Risk Assessment

To inform mitigation strategies and understand how microplastics affect wildlife, research is focused on understanding the sources, pathways, and occurrence of microplastics in the environment and in wildlife. Microplastics research entails counting and characterizing microplastics in nature, which is a labor-intensive process, particularly given the range of particle sizes and morphologies present within this diverse class of contaminants. Thus, it is crucial to determine appropriate sampling methods that best capture the types and quantities of microplastics relevant to inform the questions and objectives at hand. It is also critical to follow protocols with strict quality assurance and quality control (QA/QC) measures so that results reflect accurate estimates of microplastic contamination. Here, we assess different sampling procedures and QA/QC strategies to inform best practices for future environmental monitoring and assessments of exposure. We compare microplastic abundance and characteristics in surface-water samples collected using different methods (i.e., manta and bulk water) at the same sites, as well as duplicate samples for each method taken at the same site and approximate time. Samples were collected from 9 sampling sites within San Francisco Bay, California, USA, using 3 different sampling methods: 1) manta trawl (manta), 2) 1-L grab (grab), and 3) 10-L bulk water filtered in situ (pump). Bulk water sampling methods (both grab and pump) captured more microplastics within the smaller size range (<335 µm), most of which were fibers. Manta samples captured a greater diversity of morphologies but underestimated smaller-sized particles. Inspection of pump samples revealed high numbers of particles from procedural contamination, stressing the need for robust QA/QC, including sampling and analyzing laboratory blanks, field blanks, and duplicates. Choosing the appropriate sampling method, combined with rigorous, standardized QA/QC practices, is essential for the future of microplastics research in marine and freshwater ecosystems. Integr Environ Assess Manag 2021;17:282-291. © 2020 SETAC.

QA/QC PLAN AND EVALUATION OF FIELD STRENGTH AND PERMEABILITY VALUE FOR DEEP CEMENT MIXING

Deep Cement Mixing (DCM) is widely used to improve the strength and stiffness of soil by mixing it with cement. When DCM is used as a low permeability barrier for water cut off, permeability must be tested in addition to the usual strength values. One concern in DCM construction is the quality assurance and quality control (QA/QC) of this technique to ensure uniformity along the DCM column. It is even more crucial when low permeability is required for the DCM column to be used as a seepage cut-off in an earth bund, in addition to its strength requirement. In this application, the DCM columns require low permeability and adequate strength. In this paper, two QA/QC aspects will be evaluated: the operational control and the evaluation of the treated DCM column. The operational control in terms of mixing time, cement content, rotation speed and mixing energy will be studied to gain an understanding of how strength and permeability changes with the variability of the soil with depth. A rational QA/QC plan will be briefly proposed to ensure a consistent and rational method is developed for the evaluation of the strength and permeability variation of the treated soils over the area and the depth. These will help in the development of acceptable characteristic value for the geotechnical parameters of soils treated with DCM (in line with Eurocode 7).

Error-Proofing Diamond Drilling and Drill Core Measurements

Editor’s note: The Geology and Mining series, edited by Dan Wood and Jeffrey Hedenquist, is designed to introduce early-career professionals and students to a variety of topics in mineral exploration, development, and mining, in order to provide insight into the many ways in which geoscientists contribute to the mineral industry. Abstract The diamond drill is the most productive tool available for the earth scientist to explore and map the subsurface. However, the quality of the information obtained for analysis and modeling depends on how well the processes involved are understood so as to eliminate systematic and human error and effectively minimize the variables causing random error. This overview of the quality assurance and quality control (QA/QC) procedures required to manage these errors starts with the planning phase of a drilling program and goes through drill rig setup, borehole depth measurement, core recovery measurement, core depth registration, core orientation, borehole survey, and borehole path reconstruction. An outline follows of the methods used in the logging process to accurately depth reference the data recorded from both core and bore, as well as to ensure that the angles measured for structures are verified and correctly rotated to derive their in situ dip and dip direction or plunge and trend. To conclude, the provisions required for effective audits of the drilling and logging QA/QC processes are discussed: testing for inconsistencies, certifying that standards have been achieved, reporting on weaknesses, and making recommendations for improved performance.

Concrete strength gain monitoring with non-destructive methods for potential adoption in quality assurance

During concrete production, simple and quick testing methods are desired for assessing concrete properties. Non-destructive testing methods, NDT, are particularly valuable in the Quality Assurance and Quality Control (QA/QC) process since do not interfere with production of concrete and reduce testing time and cost. Concrete hardening, and thus strength gain, is one of the most important parameters in concrete production since it can immediately identify potential issues in concrete proportioning, curing conditions, and use of questionable ingredients that affect strength and stiffness. NDTs can provide early warnings in meeting strength requirements at early ages as well as long term strength. NDTs are also valuable in providing strength gain predictions so that follow-up construction can continue once the minimum critical strength is achieved. This research was developed based on the recommendations of a recent national study undertaken by the authors for Federal Highway Administration in developing an NDT based QA process for highway materials. Thus, it was the objective of this research to identify and assess alternative NDT methods that can be used in monitoring and/or estimating strength gain in concrete, and thus for potential adoption an NDT based QA plan. These NDTs should be fast, accurate, reliable and simple to run. The NDT methods explored in this study included: infrared thermography, ultrasonic pulse velocity, and fundamental resonance frequency. The results from such testing methods were coupled with maturity modeling for monitoring and predicting concrete strength at early ages. The results provided good relationships with the maturity index. Even though the relationships of these NDT outputs with the maturity index were based on limited set of experimental data, it is expected that their accuracy will improve with complementary testing on additional concrete mixtures. The methodology of this study is applicable elsewhere where similar materials and construction methods are used.

Development of Quality Assurance and Quality Control Guidelines for Respiratory Oscillometry in Clinic Studies

The guidelines to conduct and interpret conventional pulmonary function (PFT) tests are frequently reviewed and updated. However, the quality assurance and quality control (QA/QC) guidelines for respiratory oscillometry testing remain limited. QA/QC guidelines are essential for oscillometry to be used as a diagnostic pulmonary function test (PFT) in a clinical setting. We developed a QA/QC protocol shortly after oscillometry was introduced in our laboratory as part of a clinical study. The first clinical study began after the research personnel completed 3 h of combined didactic and hands-on training and establishment of a standard operating protocol (SOP) for oscillometry testing. All oscillometry tests were conducted using the initial SOP protocol from October 17, 2017, to April 6, 2018. At this time, the first QA/QC audit took place, followed by revisions to the SOP, the addition of a QA/QC checklist, and the development of a 12-h training program. A second audit of oscillometry tests was conducted from April 9, 2018, to June 30, 2019. Both audits were completed by a registered cardiopulmonary technologist from the Toronto General Pulmonary Function Lab. The first audit evaluated 197 paired oscillometry-PFT tests and found 10 tests (5.08%) to be invalid, with a coefficient of variation > 15%. The second audit examined 1,930 paired oscillometry-PFT tests; only 3 tests (0.16%) were unacceptable, with a coefficient of variation > 15%. Improvement in QA/QC was significantly better compared to the first audit (P < .001). Although oscillometry requires minimal subject cooperation, application of the principles that govern the conduct and application of a PFT are important for ensuring that oscillometry testing is performed according to acceptability and reproducibility. Specifically, the inclusion of a SOP, a proper training program, a QA/QC checklist, and regular audits with feedback are vital to ensure that oscillometry is conducted accurately and precisely.

Property changes of SBS modified asphalt binders during short-term aging and implications on quality management

Styrene-butadiene block copolymer (SBS) is a widely used as a modifier for improving asphalt binder properties. However, due to the lack of understanding on binder property changes during aging and sample preparation, quality control and quality assurance (QC/QA) measures are seldom applied to SBS modified asphalt binders in pavement mixtures. In this study, neat and SBS modified binders were aged at different conditions and durations, and solvent extraction and recovery (E&R) were performed on a portion of binder samples. The process of aging and E&R is to simulate asphalt mixture aging in production and construction and the retrieval of asphalt binders for QC/QA, respectively. The effects of binder aging and solvent E&R on binder quality characteristics were systematically examined, including infrared spectrum, rutting parameter, and phase angle obtained from oscillation shear, and non-recoverable creep compliance (Jnr) and percent recovery from multiple stress creep recovery (MSCR) tests. The results reveal the trends of changes in those binder characteristics in response to aging time, aging condition, and the E&R process. The mechanisms behind the trends and their implications on QC/QA are also discussed. It is anticipated that the findings of this paper contribute to the development of reasonable QC/QA measures for SBS modified asphalt in construction.

Effect of Faulty Design on Construction and Maintenance of Buildings in Asaba, Delta State, Nigeria

Aim: The aim of this study is to evaluate how faulty design affects construction and maintenance of building projects in Asaba, Delta state with a view to establishing their level of occurrence and providing ways of mitigating them.&#x0D; Study Design: It was a survey research, the study was effected via literature review and a well-structured questionnaire. Likewise, interviews were carried out to substantiate the findings of the questionnaire survey.&#x0D; Place and Duration of the Study: The study was conducted in Asaba, Delta State, Nigeria for a period of 2 years.&#x0D; Methodology: Being a survey research, 80 questionnaires were administered to the respondents and only 67 were returned which represents 84% response rate. The data collected was presented and analysed using tables, frequency, mean score and relative importance index. The analysis was aided by a computer-based software, named Statistical Package of Social Sciences (SPSS) version 22.&#x0D; Results: The study found out that; inadequate structural design, lack of details, lack of inspection, inaccurate measurement, not complying with specification, use of expired materials, wrong use of equipment, inadequate performance of equipment, unclear specification were rated as the most severe defects in each of the groups. Also, the findings showed that defects found in the study are categorized as design deficiencies, material deficiencies, construction deficiencies and subsurface deficiencies.&#x0D; Conclusion: The study concluded recommending that the designers must take into account maintenance issues during design and construction stages. Also, proper sensitization of building contractors with respect to durable materials which are suitable to the immediate environmental condition should be purse as well as the construction techniques and competence of workforce. Likewise, strict quality assurance and quality control (QA/QC) program should be encouraged during project design and construction.

Correlation Study of Planetary-Boundary-Layer-Height Retrievals from CL51 and CHM15K Ceilometers with Application To PM2.5 Dynamics in New York City

Planetary-boundary-layer-height (PBLH) plays a critical role in the study of urban air quality, weather and climate. Continuous observation is critical in understanding air pollution processes and evaluation of air quality/ weather models in the complex urban environment. In this study, we observe the PBLH variation using multiple ceilometers and lidar in New York City (NYC) during both the summer and winter time and explore the potential correlation with ground PM2.5. An automated quality control and quality assurance (QC/QA) method is developed to optimize the PBLH determination from the ceilometers (Vaisala CL51 and Lufft CHM15k) product. The PBLHs from the two ceilometers and lidar show good consistency (R2=0.68~0.88) during the convective PBL period at 15:00-21:00 UTC (10:00-16:00 EST). We also investigate the seasonal variation and diurnal evolution of PBLH and demonstrate an inverse relation between the PBLH and PM2.5 during the morning transient period of PBLH growth. Further, the correlation between the ceilometer-attenuated backscatter and ground PM2.5 and its dependences on the vertical altitude are analyzed, showing that the aerosols in the PBL are more deeply mixed while also being influenced by the relatively high humidity variability during the summer.

Application of Ground Penetration Radar and Light Weight Deflectometer for Pavement Quality Control and Quality Assessment

Pavement evaluation requires the frequent assessment of structural and functional condition. Earlier functional assessment of pavement were rapid and non destructive whereas structural evaluation required destructive testing. With growth in technology the light weight deflectometer (LWD) and ground penetrating radar (GPR) replaced the destructive testing in most part of the world. This paper highlights the use of LWD and GPR as non destructive testing tool in pavement evaluation. LWD and GPR test were conducted on the granular material to investigate the composite modulus of layer for their quality assessment. LWD test results were found to be significantly affected by the base plate diameter, contact between plate and surface layer, whereas drop height does not show significant difference on composite modulus. GPR technology has showed its versatility in pavement layer thickness evaluation, void and crack detection, and sub surface exploration. Ground coupled GPR has been used for subsurface exploration. At project level pavement management system, the combined use of GPR and deflection testing device has resulted in effective monitoring of pavement structural capacity. Hence LWD and GPR had showed its effectiveness for quality control and quality assurance (QC/QA) in PMS.

Factors Affecting Defects Occurrence in Structural Design Stage of Residential Buildings in Gaza Strip

Background: Residential buildings are an essential and significant satisfaction pillar for the human’s life to ensure a safe and durable residence. In addition, due to the rapid development and population growth in the Gaza Strip, many residential buildings and housing projects are being implemented in a short period of time especially after Gaza conflict during the year 2014. Therefore, various errors and defects are anticipated to rise during the design stage. Objectives: The aim of this paper is to identify and rank the factors affecting the occurrence of the defects in the structural design stage of residential buildings in the Gaza Strip. Methods: A survey was conducted for 134 respondents randomly selected as engineers, working for engineering consultant offices as designers, supervisors and projects managers in Gaza Strip. Results: The study reveals that the three most effective groups of factors are; the consultant administration and staff group, the drawings preparation group and the structural design group respectively. The most important factors were; ignoring soil investigation or poor soil investigation, poor or lack of engineering supervision or unqualified supervision and conflicts between architectural and structural drawings. These are the most common issues overlooked by the engineers and the contractors in the Gaza Strip. Conclusion: The study recommends to apply a strict quality assurance and quality control (QA/QC) program during design phases, providing simple and readable drawings with sufficient details for contractors, raising the awareness of owners towards conducting soil inspections prior to the design process and paying more attention to the informal buildings sector from the related authorities.

Abstract 4707: Quantifying cellular composition using laser microdissection regions of interest via automated digital image analysis of co-registered tissue thin sections

Abstract Low purity tumors often portend poor disease outcome. Understanding the compositional heterogeneity of complex tumors, such as high-grade serous ovarian cancers (HGSOC) is an area of intense study. Laser microdissection affords decoupled molecular profiling analyses of tumor and non-tumor cells not otherwise possible using routine methods. Automated documentation of LMD collection activities are needed to support the development of high stringency quality control and quality assurance (QA/QC) procedures. This study was conducted to demonstrate that histology combined with digital image analysis can be utilized to quantify tumor and stroma cell content within LMD regions of interest (ROI). A single frozen high grade serous ovarian cancer tissue specimen was acquired under an IRB-approved protocol and thin sectioned onto charged glass or polyethylene naphthalate (PEN) membrane slides followed by staining with hematoxylin and eosin H&amp;E. Tumor and stromal cell populations were harvested from membrane slides in a locoregional manner by LMD (LMD7, Leica) at ~150 µm intervals. Digital whole slide images (WSI) (Aperio ScanScope XT slide scanner, Leica) of HGSOC tissue were provided for analysis consisting of matched reference H&amp;E sections and serial sections following enrichment of tumor (n=15) or stromal cell populations (n=3). Image analysis was performed by OracleBio using the Indica Labs HALO™ platform. Classification algorithms were developed and applied to each LMD image to identify the ‘Dissection Area’ and ‘All Remaining Tissue’ as two separate ROIs. A separate cytonuclear algorithm was developed using the H&amp;E stained sections to detect cell nuclei. Each LMD image was co-registered with their respective H&amp;E image to overlay classified ROI before analysis for nuclei detection. Dissected ROIs revealed median tumor cell areas were 27.5% and median stroma cell areas were ~50% of the total tissue area observable across sections. These were consistent with histopathological estimates of tumor (~36%, R2=0.91) and stromal (~52%, R2=0.96) cellularity across sections. Data generated from co-registered post-LMD dissected Area ROI within H&amp;E sections serial to the LMD tissues highlighted that the median number of nuclei per sample within tumor (n=15) and stroma (n=3) ROI was 7,527 ± 665 and 3,470 ± 476 per mm2 respectively. The average size of nuclei detected within tumor and stroma ROI was 24.2 ± 1 and 21.4 ± 0.5µm2 respectively; a difference of ~12% between these cell types. This study highlights the successful use of histology combined with digital image analysis to quantify tumor and stroma cell numbers within HGSOC tissue subjected to LMD. Furthermore, proteogenomic analyses of LMD-recovered tumor and stromal cells will support further understanding of potential correlations between these cell types within the tumor microenvironment of HGSOC. Citation Format: Lorcan Sherry, Mark Anderson, Allison Hunt, Dave Mitchell, Julie Oliver, Thomas Conrads, Nicholas Bateman. Quantifying cellular composition using laser microdissection regions of interest via automated digital image analysis of co-registered tissue thin sections [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4707.

Toward Core-Free Pavement Compaction Evaluation: An Innovative Method Relating Asphalt Permittivity to Density

Asphalt pavement compaction quality control and quality assurance (QC/QA) are traditionally based on destructive drilled cores and/or nuclear gauge results, which both are spot measurements representing significantly less than 1 percent of the in-service pavement. Ground penetrating radar (GPR) is emerging as a tool that can be used for nondestructive continuous assessment of asphalt pavement compaction quality through measuring the pavement dielectric constant. Previous studies have established that asphalt pavement dielectric constant measurements are inversely proportional to the air void content for a given asphalt mixture. However, field cores are currently required to calibrate the measured dielectric constant to the pavement density. In this paper, a method is proposed to eliminate the need for field calibration cores by measuring the dielectric constant of asphalt specimens compacted to various air void contents. This can be accomplished with a superpave gyratory compactor (SGC), which is routinely used in the pavement industry to fabricate 6 in. (15.2 cm.) diameter specimens. However, this poses difficulties with the GPR antenna height, direct coupling, and the Fresnel zone in relation to the asphalt specimen dimension limitation. These challenges are overcome by employing a plastic spacer with a known dielectric constant between the SGC specimen and the antenna. The purpose of the spacer is to reduce GPR wave speed so that the signal reflected from the specimen is separated from the direct coupling effects at an antenna height where the Fresnel zone of the GPR is not affected by the specimen dimension. The specimen dielectric constant can then be measured using the reflection coefficient-based surface reflection method (SR) or the pulse velocity-based time-of-flight method (TOF). Also, The Hoegh–Dai model (HD model) is demonstrated to reasonably predict pavement density based on the results of field measurements and corresponding core validation, especially as compared to the conventional exponential model. Results are presented from multiple days of paving on one project, as well as a single paving day on a project with significantly different mix properties. The agreement between the HD model, coreless prediction, and field cores shows the promise for implementation of dielectric-based asphalt compaction evaluation without the need for destructive field core calibration.

ATLAS LAr calorimeter performance in LHC run 2 and electronics upgrades for next runs

Liquid argon (LAr) sampling calorimeters are employed by ATLAS for all electromagnetic calorimetry in the pseudo-rapidity region |η|<3.2, and for hadronic and forward calorimetry in the region from |η|=1.5 to |η|=4.9. In the LHC Run 2 about 150 fb−1 of data at a center-of-mass energy of 13 TeV have been recorded. The well calibrated and highly granular LAr Calorimeter reached its design values both in energy measurement as well as in direction resolution. Electronics developments are pursued for the trigger readout of the ATLAS LAr Calorimeter towards the Phase-I upgrade scheduled in the LHC shut-down period between December 2018 and early 2021. Trigger signals with finer spatial granularity and higher precision are needed in order to improve the identification efficiencies of electrons, photons, taus, jets and missing energy, at high background rejection rates, already at the Level-1 trigger. Following new TDAQ buffering requirements and high expected radiation doses in the pileup conditions of the high-luminosity LHC, the LAr Calorimeter electronics will be further upgraded (Phase-II) to readout the full 182,500 calorimeter cells at 40 MHz with 16 bit dynamic range. Developments of low-power preamplifiers and shapers to meet these requirements are ongoing in 130 nm CMOS. In order to digitize the analogue signals on two gains after shaping, radiation-hard, low-power 40 MHz 14-bit ADCs are developed using a SAR architecture in 65 nm CMOS. This contribution gives an overview of the detector operation, changes in the monitoring and data quality procedures, to cope with increased pileup, as well as the achieved performance. Results of ASIC developments including quality assurance and quality control (QA/QC) and radiation hardness evaluations, performances of the pre-production boards and results of the system integration tests, progress of QA/QC of final production boards are presented along with the overall system design for the Phase-I upgrade. Results of tests of the first prototypes of front-end components are presented, along with design studies on the performance of the off-detector readout system for the Phase-II upgrade.

Microplastics in Freshwater Biota: A Critical Review of Isolation, Characterization, and Assessment Methods.

Freshwater systems provide key pathways for microplastic (MP) pollution, and although existing studies have demonstrated the susceptibility of freshwater biota to ingestion, translocation, and trophic transfer, specific challenges pertaining to methodological standardization remain largely unresolved, particularly with respect to isolating, characterizing, and assessing MPs. Here, a critical review is performed outlining the challenges and limitations currently faced by freshwater MP researchers, which may well apply across the MP research spectrum. Recommendations are provided for methodological standardization, particularly in MP characterization, quality assurance, and quality control (QA/QC) procedures as well as reporting. Considerations for the assessment of MPs in freshwater biota as a means of improving comparisons between studies are discussed. Technological advancements, including the improvement of laboratory infrastructure for identifying MPs within the smaller size range as well as methodological standardization are essential in providing policy makers with tools and measures necessary to determine the distribution of MPs within freshwater ecosystems, while also allowing for comparability and providing compliance for future monitoring requirements.

Passive sampling capabilities for ultra-trace quantitation of atmospheric nitric acid (HNO3) in remote environments

Custom-built HNO3(g) passive diffusion-based samplers employing nylon filters were comprehensively quality assurance and quality control (QA/QC) tested, including analysis of the PTFE protective filters for potential bias. The passive samplers routinely quantified HNO3(g) mixing ratios in the Canadian boreal up to a factor of 20 lower compared to previous passive sampling dose-response determination and measurements. The use of appropriate blanks alongside field collections resulted in the detection of time-weighted mixing ratios as low as 5 parts per trillion by volume (pptv) over a monthly sampling period or 121 pptv over a 24-h sampling period. The nylon filters were tested for a single reuse to reduce resources required and no statistical difference between the measured mean value of reused and new filters between five replicates across four intercomparisons was found. This showed that a single nylon filter reuse in remote regions is sound as long as replicates are employed. The custom-built passive samplers were installed along the Newfoundland and Labrador – Boreal Ecosystem Latitudinal Transect (NL-BELT) to quantify mixing ratios of HNO3(g) in these forests. Samples generated monthly time-weighted average mixing ratios at the NL-BELT field regions. Samples were collected monthly across 15 months from the summer of 2015 through to the fall of 2016 on the order of tens to a hundred pptv. Across this time period the HNO3(g) mixing ratios ranged from 9 to 200 pptv – after incorporation of comprehensive field QA/QC – with seasonal maxima occurring during the early summer months. No consistent latitudinal trends were observed along the transect, except that the most northern region always corresponded to the lowest mixing ratios of HNO3(g) for a given observation period. Extracts of the protective PTFE filter and collocated measurements of temperature and humidity determined that previously uncertain effects on sampling accuracy likely result in a negative sampling bias of 10–30%. These unpowered devices are now demonstrated to be sensitive, affordable, simple, and redeployable for the continuous ultra-trace detection of HNO3(g) in regions such as the remote Canadian boreal forest.