Mapping Instrument Research Articles

Decade‐Long Ozone Profile Record From Suomi NPP OMPS Limb Profiler: Assessment of Version 2.6 Data

AbstractWe evaluate a decadal ozone profile record derived from the Suomi National Polar‐orbiting Partnership (SNPP) Ozone Mapping and Profiler Suite (OMPS) Limb Profiler (LP) satellite instrument. In 2023, the OMPS LP data were re‐processed with the new version 2.6 retrieval algorithm that combines measurements from the ultraviolet (UV) and visible (VIS) parts of the spectra. It employs the second order Tikhonov regularization to retrieve a single vertical ozone profile between 12.5 km (or cloud tops) and 57.5 km with a vertical resolution of about 1.9–2.5 km between 20 and 55 km. The algorithm uses radiances measured at six UV ozone‐sensitive wavelengths (295, 302, 306, 312, 317, and 322 nm) paired with 353 nm, and one VIS wavelength at 606 nm combined with 510 and 675 nm to form a triplet. Each wavelength pair or triplet is used over a limited range of tangent altitudes where the sensitivity to ozone change is strongest. A new aerosol correction scheme was implemented based on a gamma‐function particle size distribution. In addition, numerous calibration changes that affected ozone retrievals were applied to measured LP radiances, including updates in altitude registration, radiometric calibration, stray light, and spectral registration. The key version 2.6 enhancement is the improved stability of the LP ozone record confirmed by the reduction in relative drifts between LP ozone and correlative measurements, linked previously to a drift in the version 2.5 LP altitude registration.

Mapping and Characterizing Instruments for Assessing Family Nurses' Workload: Scoping Review.

The importance of knowing the workload of family nurses lies essentially in the possibility of improving health outcomes, care processes and the nurse's professional life. There is a lack of studies that fully describe the nursing workload in primary care, particularly, in the context of family health nursing, and the ideal metrics to be used remain unknown, making it impossible to characterize and therefore provide the necessary insight to acknowledge the different contributions of several aspects that embody the global workload of family nurses. The objective of this scoping review was to map the known evidence and characterize the instruments used to assess the workload of family nurses. Scoping review, according to the Joanna Briggs Institute, proposed a methodology for scoping reviews, consisting of three research stages: (1) an initial research in Medline and CINHAL; (2) an extended search, using keywords and search terms, in the following databases: JBI, CINAHL Complete, MEDLINE, Cochrane and Scopus; and (3) a search of the reference lists of the selected articles. No time limit was defined. Fourteen studies referring to ten assessment instruments were included. Nine of them analyze workload as a dimension of a broader instrument, and two studies refer to an instrument that focuses exclusively on workload. The diversity of professional competencies and contexts, the conceptual complexity of workload and the absence of a theoretical framework make it difficult to identify consensual instruments to assess the workload of family nurses. This study was prospectively registered with the Open Science Framework® on 6 September 2023, with the registration number: 3k6vr.

Abstract 2337: Accelerated optical genome mapping analysis with Stratys Compute and Guided Assembly

Abstract Background Optical genome maps (OGM) from Bionano enable the detection of genomic structural and copy number variants that cannot be detected by next-generation sequencing (NGS) technologies and are often missed by conventional cytogenetic techniques. Bionano has developed bioinformatics pipelines for calling structural and copy number variants including the Bionano Solve de novo assembly pipeline for constitutional analysis and the Rare Variant Analysis (RVA) pipeline for low-allele-fraction cancer applications. Both pipelines are computationally intensive and currently take 5-10 hours on the latest generation of the Bionano Saphyr® Compute which is deployed as a four-node compute cluster and requires significant IT resources. Methods To increase throughput and simplify the deployment of the compute resources needed to support the Stratys™ optical genome mapping instrument, Bionano has developed Stratys™ Compute. Stratys Compute improves both compute and analytical performance by adapting compute-intensive stages in the Solve pipeline to run on GPUs and by developing the Guided Assembly pipeline. Stratys Compute is powered by state-of-the-art NVIDIA RTX 6000 Ada generation cards and CUDA-optimized refinement, alignment, and structural variation detection kernels to accelerate OGM analysis. Stratys Compute is a standalone workstation placed adjacent to Stratys instrument. This will minimize the IT footprint and bypass the integration with the customer site’s data center. We have incorporated these optimizations into the new Guided Assembly pipeline, which aims to combine the low-allele fraction detection capability of the RVA pipeline with the whole genome coverage and ability to detect smaller structural variants enabled by the de novo assembly pipeline. The Guided Assembly pipeline uses the reference genome as an initial seed followed by extension, refinement, and structural variant calling. This new analysis method has been evaluated through comparison to previous results from both existing pipelines and standard benchmarking datasets used to estimate structural variant calling performance and is deployed on Stratys Compute for both constitutional and low allele-fraction applications. Results Guided Assembly has been adapted to run on GPU hardware in a simplified compute tower that can be deployed to a lab along with the Stratys instrument without the need for a dedicated server room. We found concordance between the guided assembly results and our previous de novo and RVA pipeline results. We also found increased sensitivity at low allele fractions for detecting insertion variants smaller than 5 kb and larger than 200 kb while finding equivalent performance for other variant types with the updated methods. The accelerated Guided Assembly for constitutional and low-allele-fraction applications will be available to early access customers in Q4 2023 with full commercial release in Q2 2024. Citation Format: Damla Senol Cali, Thomas Anantharaman, Martin Muggli, Samer Al-Saffar, Charles Schoonover, Neil Miller. Accelerated optical genome mapping analysis with Stratys Compute and Guided Assembly [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2337.

Implementasi Sistem Penjaminan Mutu Internal (Spmi) Dalam Meningkatkan Mutu Layanan Pendidikan

Improving the quality of education, it is important to build a culture of quality in schools through the implementation of the Internal Quality Assurance System (SPMI) as ordered by the government. This research focuses on the implementation of SPMI at SMP Lab School FIP UMJ Cirendeu Ciputat Tangerang Banten. The aim is to analyze how the implementation of SPMI improves the quality of educational services at the school. Data is collected through observation, interviews and documentation, then analyzed to draw conclusions. The research results show several aspects: 1) quality mapping instruments that are not fully in accordance with the quality indicators of the 8 National Education Standards (SNP), 2) quality fulfillment targets that are not yet optimal, 3) fulfillment of the 8 SNP fulfillment targets, 4) improving the quality of the learning process and school management, 5) improving the quality of learning outcomes, establishing a quality culture, and continuing quality improvement. Thus, the implementation of SPMI at SMP Lab School FIP UMJ Cirendeu Ciputat Tangerang Banten has a positive impact in improving the quality of educational services.

High‐resolution strain mapping in a thermionic LaB6 scanning electron microscope

AbstractThe high source stability and brightness of field emission gun equipped scanning electron microscopes (SEM) makes them ideal for high‐resolution digital image correlation (HRDIC). However, their high initial capital cost can be prohibitive for research organisations and groups. Conventional thermionic SEMs using either a tungsten hairpin or LaB6 filament are far more widespread due to their lower cost. Whilst it is understood that overall performance and ultimate resolution are lower than field emission SEMs, we propose that there is no fundamental reason why these instruments are unsuitable for HRDIC. We investigate the use of a LaB6 SEM as a viable tool for HRDIC. We detail the subtleties of performing HRDIC using a LaB6 thermionic source SEM, providing technical recommendations for best practices in using these instruments for strain mapping. The effects of instrument parameters on strain measurement noise are examined, with a focus on parameters of key relevance to in situ and ex situ mechanical testing. Errors in focus and image pixel size are found to be the primary contributors to the strain noise floor values, with stage accuracy being of secondary importance. We present a case study in oxygen‐free high‐conductivity copper, OFHC‐Cu, which is used in the designs of nuclear fusion components as a heat sink interlayer. Heterogeneous strain patterns are observed in this material, with high levels of strain localisation at grain boundaries. Active slip systems are identified using the relative displacement ratio method, demonstrating the quality of these data and the suitability of LaB6 instruments for HRDIC strain mapping, achieving performance approaching that expected of a field emission SEM.

The Effects of the Local Environment on a Compact Radio Interferometer I: Cross-Coupling in the Tianlai Dish Pathfinder Array

The visibilities measured by radio astronomical interferometers include non-astronomical correlated signals that arise from the local environment of the array. These correlated signals are especially important in compact arrays such as those under development for 21[Formula: see text]cm intensity mapping. The amplitudes of the contaminated visibilities can exceed the expected 21[Formula: see text]cm signal and represent a significant systematic effect. We study the receiver noise radiated by antennas in compact arrays and develop a model for how it couples to other antennas. We apply the model to the Tianlai Dish Pathfinder Array (TDPA), a compact array of 16, 6-m dish antennas. The coupling model includes electromagnetic simulations, measurements with a network analyzer, and measurements of the noise of the receivers. We compare the model to drift-scan observations with the array and set requirements on the level of antenna cross-coupling for 21[Formula: see text]cm intensity mapping instruments. We find that for the TDPA, cross-coupling would have to be reduced by three orders of magnitude in order to contribute negligibly to the visibilities.

Using Structured Observations to Evaluate the Effects of a Personalized Music Intervention on Agitated Behaviors and Mood in Nursing Home Residents With Dementia: Results From an Embedded, Pragmatic Randomized Controlled Trial

ObjectiveThe objective of this research was to determine if a personalized music intervention reduced the frequency of agitated behaviors as measured by structured observations of nursing home (NH) residents with dementia. DesignThe design was a parallel, cluster-randomized, controlled trial. SettingThe setting was 54 NH (27 intervention, 27 control) from four geographically-diverse, multifacility NH corporations. ParticipantsThe participants were 976 NH residents (483 intervention, 493 control) with Alzheimer's disease or related dementias (66% with moderate to severe symptoms); average age 80.3 years (SD: 12.3) and 25.1% were Black. InterventionThe intervention was individuals’ preferred music delivered via a personalized music device. MeasurementThe measurement tool was the Agitated Behavior Mapping Instrument, which captures the frequency of 13 agitated behaviors and five mood states during 3-minute observations. ResultsThe results show that no verbally agitated behaviors were reported in a higher proportion of observations among residents in NHs randomized to receive the intervention compared to similar residents in NHs randomized to usual care (marginal interaction effect (MIE): 0.061, 95% CI: 0.028–0.061). Residents in NHs randomized to receive the intervention were also more likely to be observed experiencing pleasure compared to residents in usual care NHs (MIE: 0.038; 95% CI: 0.008–0.073)). There was no significant effect of the intervention on physically agitated behaviors, anger, fear, alertness, or sadness. ConclusionsThe conclusions are that personalized music may be effective at reducing verbally-agitated behaviors. Using structured observations to measure behaviors may avoid biases of staff-reported measures.

DESIGN AND MANUFACTURE OF MEASURING INSTRUMENTS FOR INSIDE POCKET CONTOUR MAPPING USING ULTRASONIC SENSORS

In this's era, the measuring instruments used in the machining process still use a lot of mechanical principles and there are only a few that are combined with electrical components. Most of the measuring instruments that exist now are only linear and there are still few that can measure the shape of the contour. One of the tools that can be used to measure contours is CMM, but the price of this tool is very expensive. The need for tools for this contour measurement process is very much needed in the industrial world because some parts of the industry have various contour shapes and are difficult if measured without using a CMM machine. Therefore, the purpose of this study is to make a measuring instrument for contour mapping using electronic sensors. The manufacture and design of measuring instruments start with designing electricity and hardware, then continues with microcontroller programming and Matlab. This measuring instrument is then tested for linear distance measurement accuracy, accuracy per angle, and accuracy of contour shapes. The results showed that the size results had a maximum deviation of 10 millimeters with a maximum distance of 500 millimeters. The 0° angle is the worst reading angle with a deviation of 8.67 millimeters, while the 90° and 180° angles are the best reading angles with a deviation of 1 millimeter. Square and rectangular shapes can be represented quite well, while triangular shapes are less well represented due to their angles being far from perpendicular to the sensor.

Global Formaldehyde Products From the Ozone Mapping and Profiler Suite (OMPS) Nadir Mappers on Suomi NPP and NOAA‐20

AbstractWe describe new publicly available, multi‐year formaldehyde (HCHO) data records from the Ozone Mapping and Profiler Suite (OMPS) nadir mapper (NM) instruments on the Suomi NPP and NOAA‐20 satellites. The OMPS‐NM instruments measure backscattered UV light over the globe once per day, with spatial resolutions close to nadir of 50 × 50 km2 (OMPS/Suomi‐NPP) and 17 × 17 km2 or 12 × 17 km2 (OMPS/NOAA‐20). After a preliminary instrument line shape and wavelength calibration using on‐orbit observations, we use the backscatter measurements in a direct spectral fit of radiances, in combination with a nadir reference spectrum collected over a clean area, to determine slant columns of HCHO. The slant columns are converted to vertical columns using air mass factors (AMFs) derived through scene‐by‐scene radiative transfer calculations. Finally, a correction is applied to account for background HCHO in the reference spectrum, as well as any remaining high‐latitude biases. We investigate the consistency of the OMPS products from Suomi NPP and NOAA‐20 using long‐term monthly means over 12 geographic regions, and also compare the products with publicly available TROPOMI HCHO observations. OMPS/Suomi‐NPP and OMPS/NOAA‐20 monthly mean HCHO vertical columns are highly consistent (r = 0.98), with low proportional (2%) and offset (2 × 1014 molecules cm−2) biases. OMPS HCHO monthly means are also well‐correlated with those from TROPOMI (r = 0.92), although they are consistently 10% ± 16% larger in polluted regions (columns >8 × 1015 molecules cm−2). These differences result primarily from differences in AMFs.

Mesospheric and Upper Stratospheric Temperatures From OMPS‐LP

AbstractWe report the development of a temperature profile data set from the Ozone Mapping and Profiler Suite Limb Profiler (OMPS‐LP) instrument on the Suomi NPP satellite. The data set covers a roughly 10 year period from 2012 to 2022, and temperatures are provided in the altitude range between 35 and 70 km. The algorithm uses daytime Rayleigh scattered radiation near 350 nm to estimate atmospheric density profiles, which are vertically integrated using the hydrostatic equation to estimate atmospheric pressure. Temperature profiles are then derived using the ideal gas law. Spectral structures in the OMPS‐LP radiances are a source of systematic errors that limit the absolute accuracy to ±2 K. However, since the systematic errors do not change significantly over time, the relative accuracy is better than ±1 K. Our temperature data set has been designed to supplement global temperature maps produced by assimilation of data from traditional meteorological sensors, including GNSS radio occultation sensors, that provide high quality atmospheric temperature profiles up to 40–55 km. We show comparisons to other co‐located temperature datasets to validate our product.

Validation of OMPS Suomi NPP and OMPS NOAA‐20 Formaldehyde Total Columns With NDACC FTIR Observations

AbstractWe validate formaldehyde (HCHO) vertical column densities (VCDs) from Ozone Mapping and Profiler Suite Nadir Mapper (OMPS‐NM) instruments onboard the Suomi National Polar‐orbiting Partnership (Suomi NPP) satellite for 2012–2020 and National Oceanic and Atmospheric Administration‐20 (NOAA‐20) satellite for 2018–2020, hereafter referred to as OMPS‐NPP and OMPS‐N20, with ground‐based Fourier‐Transform Infrared (FTIR) observations of the Network for the Detection of Atmospheric Composition Change (NDACC). OMPS‐NPP/N20 HCHO products reproduce seasonal variability at 24 FTIR sites. Monthly variability of OMPS‐NPP/N20 has a very good agreement with FTIR, showing correlation coefficients of 0.83 and 0.88, respectively. OMPS‐NPP (N20) biases averaged over all sites are −0.9 (4) ± 3 (6)%. However, at clean sites (with VCDs < 4.0 × 1015 molecules cm−2), positive biases of 20 (32) ± 6 (18)% occur for OMPS‐NPP (N20). At sites with HCHO VCDs > 4.0 × 1015 molecules cm−2, negative biases of −15% ± 4% appear for OMPS‐NPP, but OMPS‐N20 shows smaller bias of 0.5% ± 6% due to its smaller ground pixel footprints. Therefore, smaller satellite footprint sizes are important in distinguishing small‐scale plumes. In addition, we discuss a bias correction and provide lower limit for the monthly uncertainty of OMPS‐NPP/N20 HCHO products. The total uncertainty for OMPS‐NPP (N20) at clean sites is 0.7 (0.8) × 1015 molecules cm−2, corresponding to a relative uncertainty of 32 (30)%. In the case of HCHO VCDs > 4.0 × 1015 molecules cm−2, however, the relative uncertainty in HCHO VCDs for OMPS‐NPP (N20) decreases to 31 (18)%.

Implementing an Internal Quality Assurance System to Enhance Elementary School Education Quality

An education quality assurance system is intended to enhance education quality and establish a quality culture in schools; however, some elementary schools in Indonesia still struggle with its implementation. Hence, this research aimed to suggest action steps as an option to enhance the implementation of the education quality assurance system in elementary schools. This research employed an action research design to investigate this issue and identify alternative solutions. The data were collected using a survey and semi-structured interviews with staff at one private elementary school in East Kalimantan province, namely a school principal, 31 teachers and two school foundation administrators. The findings produced nine action steps: 1) Building management commitment, 2) Setting up a quality improvement team, 3) Engaging in communication and socialization, 4) Building quality awareness, 5) Forming a quality control circle, 6) Mapping quality education, 7) Preparing a mapping instrument, 8) Collecting mapping data, and 9) Processing and analyzing mapping data. This research concludes that new school quality standards improved every year on being compared with eight points on the national education standards, and the national examination results exceeded the average national examination score at the provincial level. The increase in the average values of Standard 1–8 ranged from 0.6 to 1.5. In other words, these nine steps had an impact on obtaining school accreditation with a superior rating.

Temporal and operation-induced instability of apparent soil electrical conductivity measurements

Measuring apparent soil electrical conductivity (ECa), using galvanic contact resistivity (GCR) and electromagnetic induction (EMI) techniques, is frequently conducted to reveal spatial soil heterogeneity. Various studies have demonstrated the possibilities for significant changes in the measured quantities over time with relatively stable spatial structure representations. The objective of this study was to quantify the effects of temporal drift and operational noise for three popular ECa mapping instruments. They were placed in stationary positions approximately 8 m apart in an area with relatively low ECa. Temporal drift was assessed using a series of 4.5-h data logs recorded under different weather conditions (from extremely hot to near freezing temperatures). The two EMI instruments were also used to quantify the effect of minor changes in the height, pitch and roll of the sensor with respect to the ground. These operational noise tests were replicated over several days. Our results reveal the GCR measurements of ECa, along with perpendicular coplanar EMI measurements, have shown relatively strong stability over time. Each operational effect introduced measurement uncertainties comparable to the impact of a change in temperature and soil water content.

Instrumentation Electrode Configuration Signal Processing and Applications of Brain Computer Interfacing: A Review

Brain-Computer Interface (BCI) is a fast-emerging technology in which researchers aims to build a direct channel between the human brain and external electronic device. The methods used for this may be invasive (ECoG), or non-invasive (EEG, MEG, fMRI, etc.). EEG-based Brain Computer Interface (BCI) is used to scale the brain movement and convert them into control signals for monitoring and control. These systems are used to develop several applications like Limb Replacements for paralyzed or disabled people, Military Enhancement, Driving Safety, Games and Entertainment, Emotion Classification, etc. Though non-invasive systems have limitations in terms of ability to detect and measure electrical activity of small groups of neurons. However, they can be used for monitoring general cognitive state and brain activity for diagnosis of brain disorders and mental health issues. The review of brain activity mapping techniques, instrumentation, signal processing, and applications of BCI is presented in this paper.

Indicators of the ozone recovery for selected sites in the Northern Hemisphere mid-latitudes derived from various total column ozone datasets (1980–2020)

Abstract. We propose a method to examine the current status of the ozone recovery attributed to changes of ozone-depleting substances (ODS) in the stratosphere. The total column ozone (TCO3) datasets used are based on the ground-based (by the Dobson and/or Brewer spectrophotometer) measurements, satellite observations (from the Solar Backscatter Ultraviolet (SBUV) and Ozone Mapping and Profiler Suite (OMPS) instruments), and output of reanalyses (Multi-Sensor Reanalysis version 2 (MSR2) and Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA2)). The TCO3 time series are calculated for selected sites in the mid-latitudes of the Northern Hemisphere (NH, 35–60∘ N), which are station locations with long-term TCO3 observations archived at the World Ozone and Ultraviolet Radiation Data Centre (WOUDC). The TCO3 monthly means (1980–2020) are averaged over the April–September period to obtain TCO3 time series for the warm sub-period of the year. Two types of the averaged TCO3 time series are considered: the original one and non-proxy time series with removed natural variability by a standard multiple regression model. The TCO3 time series were smoothed by the locally weighted scatterplot smoother (LOWESS) and the super smoother (SS). The smoothed TCO3 values in 1980, 1988, 1997, and 2020 were used to build ozone recovery indices (ORIs) in 2020. These are key years in the equivalent effective stratospheric chlorine (EESC) time series for the period 1980–2020, i.e., the stratosphere was only slightly contaminated by ODS in 1980, 1988 is the year in which the EESC value is equal to its value at the end (2020), and in 1997, the EESC maximum was in mid-latitude stratosphere. The first proposed ORI, ORI1, is the normalized difference between the TCO3 values in 2020 and 1988. The second one, ORI2, is the percentage of the recovered TCO3 in 2020 since the ODS maximum. Following these definitions, the corresponding reference ranges (from −0.5 % to 1 % for ORI1 and from 40 % to 60 % for ORI2) are obtained by analyzing a set of possible EESC time series simulated via the Goddard automailer. The ozone recovery phases are classified comparing the current ORI values and their uncertainty ranges (by the bootstrapping) with these reference ranges. In the analyzed TCO3 time series, for specific combinations of datasets, data types, and the smoother used, we find faster (for ORI1 or ORI2 above the reference range) and slower (for ORI1 or ORI2 below the reference range) recovery in 2020 than that inferred from the EESC change, and a continuation of the TCO3 decline after the EESC peak (ORI2<0 %). Strong signal of the slower TCO3 recovery is found in Toronto, Hohenpeissenberg, Hradec Kralove, and Belsk. A continuation of ozone decline after the turnaround in ODS concentration is found in both the original and non-proxy time series from WOUDC (Toronto), SBUV and OMPS (Toronto, Arosa, Hohenpeissenberg, Uccle, Hradec Kralove, and Belsk), and MERRA2 data (Arosa, Hohenpeissenberg, Hradec Kralove, and Belsk).

Tomographic Retrievals of Hunga Tonga‐Hunga Ha'apai Volcanic Aerosol

AbstractThe 2022 eruption of the Hunga Tonga‐Hunga Ha'apai volcano caused substantial impacts on the atmosphere, including a massive injection of water vapor, and the largest increase in stratospheric aerosol for 30 years. The Ozone Mapping and Profiler Suite (OMPS) Limb Profiler instrument has been critical in monitoring the amount and spread of the volcanic aerosol in the stratosphere. We show that the rapid imagery from the OMPS instrument enables a tomographic retrieval of the aerosol extinction that reduces a critical bias of up to a factor of two, and improves vertical structure and agreement with coincident lidar and occultation observations. Due to the vertically thin and heterogeneous nature of the volcanic aerosol, this impacts integrated values of aerosol across latitude, altitude, and time for several months. We also investigate the systematic impact of uncertainty in assumed particle size that result in an underestimation of the aerosol extinction at the peak of the volcanic aerosol layer.

Reconstruction algorithms for grain mapping by laboratory X-ray diffraction contrast tomography.

X-ray-based non-destructive 3D grain mapping techniques are well established at synchrotron facilities. To facilitate everyday access to grain mapping instruments, laboratory diffraction contrast tomography (LabDCT), using a laboratory-based conical polychromatic X-ray beam, has been developed and commercialized. Yet the currently available LabDCT grain reconstruction methods are either ill-suited for handling a large number of grains or require a commercial licence bound to a specific instrument. To promote the availability of LabDCT, grain reconstruction methods have been developed with multiple reconstruction algorithms based on both forward and back calculations. The different algorithms are presented in detail and their efficient implementation using parallel computing is described. The performance of different reconstruction methods is assessed on synthetic data. The code to implement all the described algorithms has been made publicly accessible with the intention of fostering the development of grain mapping techniques on widely available laboratory instruments.

Quantitative laser-induced breakdown spectroscopy mapping of centerline segregation via optical emissions of Mn and Cr in steel wire rod products

A steel wire rod is one of the cast steel products used for springs to absorb repeated shocks, particularly in harsh conditions. Quality assessment of steel wire rods is critically important to prevent unwanted breakage during their lifetime. However, centerline segregation is the most common cause of weakened steel wire rods. Currently, centerline segregation is monitored using an optical microscope and an electron probe microanalyzer (EPMA). Herein, we demonstrate quantitative concentration mapping of Mn and Cr, the representative alloying elements, in steel wire rods using laser-induced breakdown spectroscopy (LIBS) as an alternative centerline segregation monitoring methodology. Sensitivity, detection limit, precision, and spatial resolution were found to be enough to observe centerline segregation. Concentration maps obtained by LIBS were very similar to those from EPMA. Microscopic matrix changes due to segregation were also identified. The resulting decrease in plasma temperatures was rationalized by formation of metal carbides that hardened local segregated areas. Considering the rapid multi-elemental mapping capability of LIBS in open air, LIBS is suggested as a practical alternative to optical microscope limited to carbon mapping and EPMA that needs high-vacuum equipment for screening faulty steel wire rod products. The centerline segregation of Mn and Cr in steel wire rods are rapidly monitored by laser-induced breakdown spectroscopy mapping. • A LIBS instrument for rapid elemental mapping for steel wire rods was developed • Centerline segregation of Mn and Cr was well observed by the LIBS instrument • Microscopic matrix changes due to the centerline segregation were identified and rationalized • LIBS outperforms optical microscopy in terms of simplicity in sample preparation and multiple element mapping for monitoring centerline segregation • LIBS is faster and more cost-effective than EPMA for monitoring centerline segregation

NO2 retrievals from NOAA-20 OMPS: Algorithm, evaluation, and observations of drastic changes during COVID-19

We present the first NO2 measurements from the Nadir Mapper of Ozone Mapping and Profiler Suite (OMPS) instrument aboard the NOAA-20 satellite. NOAA-20 OMPS was launched in November 2017, with a nadir resolution of 17 × 13 km2 similar to the Ozone Monitoring Instrument (OMI). The retrieval of NOAA-20 NO2 vertical columns were achieved through the Direct Vertical Column Fitting (DVCF) algorithm, which was uniquely designed and successfully used to retrieve NO2 from OMPS aboard Suomi National Polar-orbiting Partnership (SNPP) spacecraft, predecessor to NOAA-20. Observations from NOAA-20 reveal a 20–40% decline in regional tropospheric NO2 in January–April 2020 due to COVID-19 lockdown, consistent with the findings from other satellite observations. The NO2 retrievals are preliminarily validated against ground-based Pandora spectrometer measurements over the New York City area as well as other U.S. Pandora locations. It shows OMPS total columns tend to be lower in polluted urban regions and higher in clean areas/episodes associated with relatively small NO2 total columns, but generally the agreement is within ±2.5 × 1015 molecules/cm2. Comparisons of stratospheric NO2 columns exhibit the excellent agreement between OMPS and OMI, validating OMPS capability in capturing the stratospheric background accurately. These results demonstrate the high sensitivity of OMPS to tropospheric NO2 and highlight its potential use for extending the long-term global NO2 record.

Erythemal UV radiation across Nigeria: where do we stand?

The deleterious effects of solar ultraviolet (UV) radiation on humans are of public health concern which demands constant global monitoring and intervention. This study analysed the latitudinal variations in mean daily and multi-year erythemal ultraviolet radiation (EUVR) across 7 states in Nigeria using satellite data from the Total Ozone Mapping Spectrophotometer (TOMS) and Ozone Mapping Instrument (OMI). The latitudes studied were 13° N, 8° N, 6° N and 4° N respectively, using 37 years of data obtained from phases: 1979–1988, 1989–1998, 1999–2008 and 2009–2020. The data obtained were statistically analysed using Ms Excel and MATLAB. The results of this study show that the mean daily EUVR at the selected latitudes ranges from 32.97 to 390 (mW/m2). The results show that Borno State located at latitude 13° N had the highest EUVR, while Rivers State recorded the least EUVR at latitude 4° N. Comparative analysis of all the locations studied indicates latitudinal and longitudinal variations because the eastern axis recorded higher values than its western counterpart on the same latitude. Box and whisker plots in this study summarized the latitudinal variance in the mean multi-year EUVR in each phase. Box and whisker plots from 2009–2020 showed that there was a drastic reduction in mean multi-year EUVR in this phase unlike in the other phases. The findings of this study when compared to the UV index show that the 37 years mean EUVR obtained across Nigeria ranged from 8–10 which is on the “very high” category. This study recommends the implementation of WHO suggestions in preventing the biological effects of solar UV radiation. Furthermore, the Nigerian government should curb ignorance among its citizens by heightening public awareness of the effects of EUVR.