Test Site Research Articles

Minimal effect of scanning parameters on ultrasound shear wave elastography variability in tendons.

Ultrasound shear wave elastography has potential use in assessing tendon tissue; however, reducing measurement variability remains challenging. The primary purpose of this study was to identify the amount of variability accounted for by ultrasound parameter (frequency, harmonics and CrossXBeam) settings on shear wave speed at two testing sites. Shear wave elastography images of the Achilles tendon were obtained from individuals with healthy tendons (n = 28) at two testing sites with standardised image acquisition/postprocessing protocols. Images were acquired at a range of frequencies (7-15 MHz) with CrossXBeam (a filtering technique) and harmonics settings toggled on and off. Variance decomposition analysis was performed to identify the amount of variability in shear wave speed accounted for by scan acquisition settings and testing sites. Shear wave speed variance was primarily attributed to participants (56.87% of variance; residual error: 35%). All scanning parameters, testing site and interaction terms each accounted for less than 2.5% of the variance. A statistically significant, negative relationship was observed between shear wave speed and image quality (p = 0.001) suggesting poor image quality yields higher shear wave speed estimates. The findings of this study suggest that natural variation in Achilles tendon mechanics between individuals without tendon pathology accounts for most of the shear wave speed variability. Optimising image quality, which may be observed in higher frequencies, should be considered to improve shear wave speed estimation. Clinically, this study highlights the need to take multiple images, maintain consistent ultrasound settings when tracking patient progress over time and use caution when comparing raw values from tendon scans performed in different clinics with shear wave elastography. Level III.

Efficacy of Locally Delivered Herbal Chip Containing (8% Mimusops elengi) as an Adjunct to Scaling and Root Planing in Chronic Periodontitis: A Randomised Split-mouth Clinical Study

Introduction: Conventional mechanical debridement does not remove all pathogenic bacteria from the subgingival environment. To overcome these limitations, local drug delivery systems enhance the curative effect by combining with drugs, which promote bone and tissue regeneration. Thus, this study aims to evaluate the efficacy of locally delivered herbal chips containing (8% Mimusops elengi) as an adjunct to scaling and root planing (SRP) and compared to SRP alone for the treatment of chronic periodontitis. Materials and Methods: A randomised split-mouth clinical study was conducted among chronic periodontitis patients undergoing periodontal therapy. Thirty subjects with 60 sites were divided into test and control groups. The control sites were treated with SRP alone, whereas the test sites were treated with SRP followed by placement of an 8% M. elengi herbal chip within the pockets. Patients were recalled on the 21st and 45th day, and clinical parameters were measured. Results: An inter-group comparison of all the clinical parameters between the control and test sides was statistically analysed. At all periods of the study, the mean difference was observed to be highly significant (P < 0.001). Conclusion: The 8% M. elengi chip is effective as an adjunct to non-surgical periodontal therapy in chronic periodontitis probing depth. Further clinical studies are needed to evaluate the long-term efficacy of M. elengi.

The Demands of the Disabled: Masculinity, Disability, and Citizenship in the Late Imperial Russian Military

AbstractIn the years after 1905, catastrophic war, widespread political and social unrest, and rising demands from across all segments of the empire’s population forced the Russian imperial state to develop a rudimentary social contract with military personnel and implement a series of reforms to prevent the reoccurrence of military disaster and mass social unrest. These reforms entitled disabled veterans to some forms of state support that were denied to their civilian counterparts, including assistance finding work, pensions, and free prosthetic devices. These entitlements were part of a broader shift away from paternalistic approaches to social welfare provision toward the early germinations of a gendered and selective welfare state. Disability support was dependent on proximity to the military, which cemented the idea that civic inclusion—and by extension, Russian manhood—was something achieved only through military service. This article examines interactions between veterans with disabilities and representatives of the Russian imperial state to explore shifting conceptions of masculinity and the development of new political subjectivities in the aftermath of war. The Russian imperial military can be regarded as a test site within which masculine identities were negotiated and reconfigured amid the social, economic, and political transformations of the late imperial period.

Exploring land use dynamics in rural areas. An analysis of eight cases in the Global North

Rural areas are pivotal in the global economy, hence rural development planners and decision makers face significant technical and information management challenges, hindering their ability to assess sustainable development and formulate strategies. These challenges, coupled with shifts in traditional rural activities, aging populations, and climate change impacts, create inequalities and threaten rural communities. Therefore, developing approaches for the assessment of changes in rural areas are required. In recent years, remote sensing has emerged as a useful tool for monitoring the complex dynamics of rural regions, with a notable increase in the accessibility and use of freely available satellite data and platforms for tracking changes in land use and land cover (LULC). In light of this trend, this article analyzes the spatio-temporal trends in eight different development regions in Japan, Germany, Poland and Spain and integrates them with population data. This research relied on the utilization of openly available datasets - satellite imagery from Landsat and WorldPop population data, processed in Google Earth Engine (GEE). The time series of Landsat imagery were employed to analyze changes in LULC over a 20-year period from 2000 to 2020 in each test site. Unique combinations (i.e. each pixel history) were systematically examined and categorized based on established rules, with improbable scenarios marked as "uncertain." The comparison demonstrates that all eight regions have unique spatial, temporal and thematic characteristics. The most significant changes observed include the transformation of tree-covered areas into built-up areas in the case of Tsukuba and into agricultural lands in Shibushi. In the Bodzentyn and Połaniec communes in Poland, agricultural lands have transitioned into forested areas. In Spain, there is an increase in built-up areas, particularly at the outskirts of established towns. In Germany, the results indicate an expansion of built-up and agricultural areas in the Fürth region, while the Regen region experienced an increase in agricultural land. Incorporating population data reveals relationships between different types of LULC conversions and population trends, showing clear positive trends in areas transformed from agricultural and tree-covered land to built-up areas, with the most profound changes observed in Spanish cases and Tsukuba. The findings from automatic LULC classification highlight the usefulness of this tool in identifying socio-economic changes, especially when it is integrated with and compared to statistical data. Policy makers and planners at local levels should consider these specific values as a foundational reference point for shaping their plans related to sustainable development, land use, environmental preservation, and resource management.

Medium-Scale Soil Moisture Retrievals Using an ELBARA L-Band Radiometer Using Time-Dependent Parameters for Wetland-Meadow-Cropland Site

The soil moisture at the medium spatial scale is strongly desired in the context of satellite remote sensing data validation. The use of a ground-installed passive L-band radiometer ELBARA at the Bubnów-Sęków test site in the east of Poland gave a possibility to provide reference soil moisture data from the area with a radius of 100 m. In addition, the test site comprised three different land cover types that could be investigated continuously with one day resolution. The studies were focused on the evaluation of the ω-τ model coefficients for three types of land cover, including meadow, wetland, and cropland, to allow for the assessment of the soil moisture retrievals at a medium scale. Consequently, a set of reference time-dependent coefficients of effective scattering albedo, optical depth, and constant-in-time roughness parameters were estimated. The mean annual values of the effective scattering albedo including two polarisations were 0.45, 0.26, 0.14, and 0.54 for the meadow with lower organic matter, the meadow with higher organic matter, the wetland, and the cropland, respectively. The values of optical depth were in the range from 0.30 to 0.80 for the cropland, from 0.40 to 0.52 for the meadows (including the two investigated meadows), and from 0.60 to 0.70 for the wetland. Time-constant values of roughness parameters at the level of 0.45 were obtained.

The use of fixed shelling percentage biases genotype selection in hybrid maize multi-environment yield trials

Context or problemPhenotyping is an integral part of plant breeding operations. In many cases the trait measured is not identical to the target trait for reasons of speed and or cost. This is a form of indirect selection, where correlation between the trait measured and the target phenotype influences the rate of genetic gain. Low correlations lead to slow rates of genetic gain. In sub-Saharan African maize breeding programs, maize grain yield in breeding experimental plots is measured as a field weight (FW), which includes the grain and cob. The weight of grain from each plot is estimated as a standard proportion of grain to total ear weight using a shelling percentage of 80 %. This approach assumes that there is no genetic, environment or genetic by environment interaction in shelling percentage which, if present, would contribute to slower rates of genetic gain for grain yield. Objective or research questionThis study investigated the magnitude of genetic and environmental variation in shelling percentage and its impact on selection in six hybrid maize multi-environment yield trials in Ethiopia over two seasons. MethodsThe data of shelled grain weight (SW) and cob weight (CW) from the trials were analyzed using a bivariate linear mixed model. ResultsGenetic variances for both traits varied across the six testing sites ranging from 0.199 to 2.975 for SW and from 0.029 to 0.245 for CW. The genetic correlations between pairs of sites for SW and CW also varied, indicating the existence of genotype by environment interaction for these traits. Additionally, the bivariate regressions between FW and SW indicated there was substantial genetic deviation around the 80 % shelling response, and this relationship was impacted by environmental influences. ConclusionThe use of a constant relationship of 80 % shelling biases grain yield prediction in multi-environment hybrid maize yield trials and thus reduces the rate of genetic gain in maize breeding programs. Implications or significanceTaking into account the variations in the shelling percentage of the genotypes across sites in predicting grain yield from field weight improves the accuracy of genotype selection and the rate of genetic gain in maize breeding programs.

Undrained shear strength estimation through instrumented free-fall penetration tests using spherical and conical penetrometers

This paper presents (i) results from a series of instrumented free-fall penetration (FFP) tests performed, under laboratory-controlled conditions, in a large-scale testing facility and (ii) a simple methodology to predict undrained shear strength su from FFP test data without resorting to assumptions on the values of different parameters. Comparison of soil resistance derived from acceleration data recorded during FFP tests with soil resistance recorded during constant rate penetration (CRP) tests using a ball penetrometer reveals unique relationships between dynamic and constant-rate penetration resistances for different shapes of FFP tools. Based on regression analysis, expressions are proposed for calculation of resistance ratio ξr for three different shapes of FFP tool. The proposed expressions for ξr further facilitate the prediction of undrained shear strength su employing acceleration data recorded during FFP tests. FFP-based predictions of su show excellent agreement with CRP-based su prediction in three different laboratory testbeds. Furthermore, the proposed methodology successfully predicts su profile at a field test site using FFP test data reported in the literature.

From simple labels to semantic image segmentation: leveraging citizen science plant photographs for tree species mapping in drone imagery

Abstract. Knowledge of plant species distributions is essential for various application fields, such as nature conservation, agriculture, and forestry. Remote sensing data, especially high-resolution orthoimages from unoccupied aerial vehicles (UAVs), paired with novel pattern-recognition methods, such as convolutional neural networks (CNNs), enable accurate mapping (segmentation) of plant species. Training transferable pattern-recognition models for species segmentation across diverse landscapes and data characteristics typically requires extensive training data. Training data are usually derived from labor-intensive field surveys or visual interpretation of remote sensing images. Alternatively, pattern-recognition models could be trained more efficiently with plant photos and labels from citizen science platforms, which include millions of crowd-sourced smartphone photos and the corresponding species labels. However, these pairs of citizen-science-based photographs and simple species labels (one label for the entire image) cannot be used directly for training state-of-the-art segmentation models used for UAV image analysis, which require per-pixel labels for training (also called masks). Here, we overcome the limitation of simple labels of citizen science plant observations with a two-step approach. In the first step, we train CNN-based image classification models using the simple labels and apply them in a moving-window approach over UAV orthoimagery to create segmentation masks. In the second phase, these segmentation masks are used to train state-of-the-art CNN-based image segmentation models with an encoder–decoder structure. We tested the approach on UAV orthoimages acquired in summer and autumn at a test site comprising 10 temperate deciduous tree species in varying mixtures. Several tree species could be mapped with surprising accuracy (mean F1 score =0.47). In homogenous species assemblages, the accuracy increased considerably (mean F1 score =0.55). The results indicate that several tree species can be mapped without generating new training data and by only using preexisting knowledge from citizen science. Moreover, our analysis revealed that the variability in citizen science photographs, with respect to acquisition data and context, facilitates the generation of models that are transferable through the vegetation season. Thus, citizen science data may greatly advance our capacity to monitor hundreds of plant species and, thus, Earth's biodiversity across space and time.

Determination of Constrained Modulus of Granular Soil from In Situ Tests—Part 2 Application

The paper demonstrates how the concepts presented in the companion paper: “Determination of Constrained Modulus of Granular Soil from In Situ Tests—Part 1 Analyses” can be applied in practice. A settlement design based on the tangent modulus method is described. Extensive in situ tests were performed on a well-documented test site consisting of sand with silt and clay layers. The field tests comprised different types of penetration tests, such as the cone penetration test, the flat dilatometer, and the seismic down-hole test. The modulus number and the constrained tangent modulus were derived from the cone penetration test with pore water pressure measurement and the flat dilatometer test. In addition, the shear wave speed was determined from two seismic down-hole tests, from which the small-strain shear modulus could be evaluated. The constrained modulus obtained from the cone penetration test with pore water pressure measurement (CPTU) and the flat dilatometer (DMT) was compared with that from the seismic down-hole tests. The importance of the stress history on the constrained modulus was demonstrated. The range of modulus numbers, derived from different in situ tests, compares favorably with empirical values reported in the literature.

Evaluation of a Rapid Drug Test Device for Urine Fentanyl Compared to Mass Spectrometry and 2 Urine Fentanyl Assays.

A new Rapid Drug Test Device (RDTD) is available for analysis of urine fentanyl. With the rise in fentanyl abuse in the United States, we evaluated the analytical performance of the RDTD test strip compared to mass spectrometry and 2 urine fentanyl immunoassays. Leftover, deidentified urine samples collected from inpatients and outpatients from our psychiatric hospital and other clinics were frozen at <-70°C, thawed at room temperature, and centrifuged. Aliquots were tested with the RDTD (CLIA Waived, Inc.) test strips and 2 urine fentanyl immunoassays: the ARK Fentanyl II assay (ARK Diagnostics Inc.) and the Immunalysis SEFRIA Fentanyl assay (Immunalysis Corporation). Both assays were conducted on the Abbott Alinity c chemistry analyzer (Abbott Laboratories). Mass spectrometry analysis was performed at ARUP Laboratories. All assays had a 1 ng/mL positive cutoff. A total of 142 urine samples included 70 positive and 72 negative samples. The RDTD strips had lower sensitivity (84.3%) and efficiency (85.9%) and showed a specificity of 87.5% compared to the other assays. The ARK Fentanyl II assay showed identical sensitivity (95.7%) to the Immunalysis SEFRIA Fentanyl assay but had higher specificity (94.4% vs 81.9%) and overall efficiency (95.1% vs 88.7%). Differences were noted in the number of false negatives and positives among the assays. The RDTD demonstrated acceptable performance in detecting urine fentanyl in our patient population and would provide faster test results at point-of-care testing sites in our healthcare enterprise.

Metagenome-assembled genomes provide insight into the metabolic potential during early production of Hydraulic Fracturing Test Site 2 in the Delaware Basin.

Demand for natural gas continues to climb in the United States, having reached a record monthly high of 104.9 billion cubic feet per day (Bcf/d) in November 2023. Hydraulic fracturing, a technique used to extract natural gas and oil from deep underground reservoirs, involves injecting large volumes of fluid, proppant, and chemical additives into shale units. This is followed by a "shut-in" period, during which the fracture fluid remains pressurized in the well for several weeks. The microbial processes that occur within the reservoir during this shut-in period are not well understood; yet, these reactions may significantly impact the structural integrity and overall recovery of oil and gas from the well. To shed light on this critical phase, we conducted an analysis of both pre-shut-in material alongside production fluid collected throughout the initial production phase at the Hydraulic Fracturing Test Site 2 (HFTS 2) located in the prolific Wolfcamp formation within the Permian Delaware Basin of west Texas, USA. Specifically, we aimed to assess the microbial ecology and functional potential of the microbial community during this crucial time frame. Prior analysis of 16S rRNA sequencing data through the first 35 days of production revealed a strong selection for a Clostridia species corresponding to a significant decrease in microbial diversity. Here, we performed a metagenomic analysis of produced water sampled on Day 33 of production. This analysis yielded three high-quality metagenome-assembled genomes (MAGs), one of which was a Clostridia draft genome closely related to the recently classified Petromonas tenebris. This draft genome likely represents the dominant Clostridia species observed in our 16S rRNA profile. Annotation of the MAGs revealed the presence of genes involved in critical metabolic processes, including thiosulfate reduction, mixed acid fermentation, and biofilm formation. These findings suggest that this microbial community has the potential to contribute to well souring, biocorrosion, and biofouling within the reservoir. Our research provides unique insights into the early stages of production in one of the most prolific unconventional plays in the United States, with important implications for well management and energy recovery.

Under and Through Water Datasets for Geospatial Studies: the 2023 ISPRS Scientific Initiative “NAUTILUS”

Abstract. Benchmark datasets have become increasingly widespread in the scientific community as a method of comparison, validation, and improvement of theories and techniques thanks to more affordable means for sharing. While this especially holds for test sites and data collected above the water, publicly accessible benchmark activities for geospatial analyses in the underwater environment are not very common. Applying geomatic techniques underwater is challenging and expensive, especially when dealing with deep water and offshore operations. Moreover, benchmarking requires ground truth data for which, in water, several open issues exist concerning geometry and radiometry. Recognizing this scientific and technological challenge, the NAUTILUS (uNder And throUgh waTer datasets for geospatIaL stUdieS) project aims to create guidelines for new multi-sensor/cross-modality benchmark datasets. The project focuses on (i) surveying the actual needs and gaps in through and under-the-water geospatial applications through a questionnaire and interviews, (ii) launching a unique publicly available database collecting already existing datasets scattered across the web and literature, (iii) designing and identifying proper test site(s) and methodologies to deliver to the extended underwater community a brand-new multi-sensor/cross-modality benchmark dataset. The project outputs are available to researchers and practitioners in underwater measurements-related domains, as they can now access a comprehensive tool providing a synthesis of open questions and data already available. In doing so, past research efforts to collect and publish datasets have received additional credit and visibility.

Factors Influencing the Uptake of HIV Testing Services among Youths living at Lake Katwe Landing Site, Kasese District

HIV remains one of the most serious global health threats. Globally, 38 million people are living with HIV, 68% of these in Sub-Saharan Africa. The main objective was to assess the factors influencing the uptake of HIV testing services among youths living at the Lake Katwe landing site, Kasese district. A health facility-based descriptive cross-sectional study design among 50 youths living at Lake Katwe landing site, Kasese district. Participants were chosen using a snowball sampling method. The data was collected by using a pretested interviewer semi-structured questionnaire. The collected data was analyzed at two levels (univariate and bivariate) using SPSS version 22.0. Out of 50 participants, it was found that; 40 (80.0%) of the participants had ever tested for HIV, 10(20.0%) had never tested for HIV 34(68.0%) had less than twice tests, 6(12.0%) tested more than twice in a year. Several factors were significantly associated with the uptake of HIV testing services and these include; the participant’s age (Pvalue=0.001*), marital status (P-value=0.003*), participant’s occupation (0.009*), Participant’s preferred site for HIV testing (P-value=0.013*), Participants’ trust towards health workers (P-value=0.000*), Types of services wanted by the participants and Waiting hours when getting the HIV testing services (P-value=0.043*) respectively and Quality of the services provided (P-value=0.033*).Conclusively, the uptake of HIV testing services was low at 20.0% among youth and this low uptake was among youths who were singles and unemployed, however, participants who preferred private clinics and self-testing, lack of trust towards health workers and the quality of the services provided by health facilities were significantly associated with the uptake of HIV testing services. Keywords: Influencing Factors, HIV Testing Services, Youths, Health Care Services

Environmental Impact of Petroleum Refinery Effluent on Groundwater Pollution: A Case Study of Maysan Refinery, Iraq

The study aimed to investigate the environmental impact of the refinery's wastewater on groundwater within the refinery and the surrounding area. Six different testing sites were chosen to measure the concentrations of groundwater pollutants according to their distance from the untreated oil effluent discharge lagoon. The study period lasted for six months, as the testing work began in April and ended in September 2023. The results showed a clear effect of untreated petroleum effluent on the properties of groundwater, as the concentrations of petroleum effluent (oil and grease, TOC, phenol) and heavy metals (Ni, Cd, Pb) exceeded the permissible limits, as well as related parameters (TDS, EC, Cl, SO4) according to WHO specifications. As for the concentrations of the parameters (BOD, COD), there was no clear effect of the effluent on them, and on the contrary, their values began to increase at the testing sites far from the refinery. The groundwater was greatly affected by a distance of 5 km from the effluent collection lagoon (testing sites:GW1, GW2, GW3, and GW4), and it was not suitable for human use until after it was treated. As for the remaining of the distance (testing sites:GW5, GW6) to the nearest residential area (from 5 km to 9 km), the groundwater was limited to use for irrigation according to WQI guidelines. The study recommends that, in order to reduce pollution of refinery effluent, the responsible administration should use regular wastewater networks, construct a treatment plant for this effluent, and discharge the treated effluent to the nearest water source

Pre-trained regional models for extracting buildings from high resolution satellite imagery to support public health initiatives

Up-to-date building locations provide a pivotal layer of information for public health initiatives and emergency responses to identify and reach a target population. Using pre-trained deep learning models to extract buildings from high-resolution imagery reduces the time and resources required but often under-perform in new locations with landscapes and building types different from that used for training the models. This study aims to develop and evaluate deep learning models for extracting buildings from high-resolution satellite imagery for a region of interest. The main objectives are to use openly available codebase, base models, and training datasets from a region to build models, to use the pre-trained regional models to extract buildings from other locations in the region, and to assess the accuracies of the models. The regional models are also fine-tuned with data from a new location to build and evaluate local models. Two regional models for Bangladesh outperformed a baseline model for low- and middle-income countries, with a 30% increase in mean accuracy (F1-scores), in three test sites. Among the regional models, a model trained with data exclusively from the region performed better (mean F1-score: 0.57) than a model built by fine-tuning the baseline model with regional training data (mean F1-score: 0.45). Local models based on the regional models also outperformed other local models. This study demonstrates the potential of pre-trained regional models in expediting building extraction, but points out the challenges associated with limited training data.

The factor structure of the Hopkins Symptom Checklist 25 among persons seeking HIV testing

ABSTRACT Rates of anxiety and depression are high among individuals living with HIV. The Hopkins Symptom Checklist (HSCL) is a screening tool to identify symptoms of depression and anxiety. The objective of this study was to determine the factor structure of the 25-item HSCL in a population-based sample of individuals seeking HIV testing in the Western Cape in South Africa. Participants volunteered for HIV testing at two non-medical HIV testing sites in the Western Cape. We used convenience sampling to administer the scale prior to their undergoing HIV testing. Data were analysed using exploratory factor analysis, using an extraction method of principal components with Promax (oblique) rotation. The Cronbach's alpha reliability indices were calculated for each of the independent factors to determine internal consistency. Factor analysis revealed a three-factor structure that explained 56.86% of the total variance. These factors included depression (14 items), anxiety (7 items) and somatic symptoms (4 items). Alpha levels ranged from 0.67 to 0.94. We found that the HSCL is a reliable measure for depression and anxiety, and consists of 3 distinguishable factors depression, anxiety, and somatic symptoms.

Effective stewardship strategies to enhance appropriateness of refer-out test requests in a Canadian tertiary centre laboratory

ObjectivesSpecialized testing conducted in reference laboratories is costly and often not optimally directed. Since 2016, our institution has worked to ensure the appropriateness of refer-out (RO) tests. We examine the impact of utilization initiatives on the patterns of requests and completed tests. Design and methodsIn 2016, 81 RO tests were selected for a more rigorous approval process. Physicians not pre-approved for testing received a prompt to consult with laboratory subject matter experts (SMEs) for further detail. After review, SMEs provided responses, approving or rejecting requests based on clinical relevance. Stewardship activities also included: repatriating tests locally, preferring Canadian over foreign institutions, unbundling tests, distributing educational memos, and introducing staged testing. We collected data on the number of requested (NoR) and number of completed (NoC) tests in 2015, before the implementation of the new vetting procedures, and for the post-implementation phase from 2016−2022. ResultsFor 62 targeted RO tests (including trace metals, vitamins, antibodies, and endocrine-related tests), there was a 33% reduction in NoR and a 51% reduction in NoC in 2022 compared to 2015. The total savings for the study period based on NoC was $807,736. The NoC rate for Neuronal antibody tests decreased to 48.6% in 2022, with cost savings of $17,123, and an additional $50,000 saved by changing the testing site. Insourcing apolipoprotein B and fecal calprotectin tests resulted in cost savings of $3,380 and $3,371, respectively, in 2022. ConclusionsAutomated messaging followed by a formal review of RO test requests is an effective utilization strategy that prevents redundant or clinically unjustified testing. This approach leads to significant economic savings and is expected to improve the efficiency of patient care.

Robust CO2 plume imaging by joint tomographic inversion using distributed pressure and temperature measurements

The scientific community has become increasingly interested in geological CO2 sequestration and CO2 enhanced oil recovery (EOR). The tracking of the CO2 propagation in both space and time during geologic sequestration is necessary to ensure the secure and effective handling of a site for CO2 injection. Our objective is to develop efficient and novel models and monitoring techniques for visualizing CO2 plumes using field measurements. As a first step, the streamline-based data integration approach is extended to include data from distributed temperature sensors (DTS). The DTS and pressure data are then jointly history matched using a hierarchical workflow combining evolutionary and streamline methods. As a final step, we will create maps that visualize CO2 propagation during the sequestration process based on saturation and streamline maps. We validate the extended streamline-based inversion method using a synthetic model. An application of the hierarchical workflow is then made to the CO2 geologic storage test site in Michigan, USA. Monitoring data includes bottom-hole pressure of the injection well, DTS data at the monitoring well, and distributed pressure measurements from several downhole sensors along the monitoring well. Based on the history matching results, the CO2 movement is largely limited to the zones intended for injection, which is in agreement with an independent warmback analysis of the temperature data. The novelty of this work is the extension of the streamline-based inversion algorithm for the DTS data, its field application to the Department of Energy regional carbon sequestration project, and potential extensions to other CO2-EOR and/or associated geological storage projects.

3D spatial distribution of soil pollutants based on geo-shadowing anisotropic RBF-PCA

Research on soil contamination has become increasingly important, but there is limited information about where to sample for pollutants. Thus, the use of three-dimensional (3D) spatial interpolation techniques has been promoted in this area of study. However, the application of traditional interpolation methods is limited in geography, especially in the expression of anisotropy, and it is not associated with geographical properties. To address this issue, we used a test site (a factory in Nanjing) to develop a new research method based on the geographical shading radial basis function (RBF) interpolation method, which considers 3D anisotropy and geographical attribute expression. Drilling and uniform sampling were used to sample the contaminated area at this test site. This approach included two steps: i) An ellipsoid with anisotropic properties was constructed. Thus, the first step was to determine the shape of the ellipsoid using principal component analysis (PCA) to determine the main orientations and construct a rotational and stretched matrix. The second step was determining the ellipsoid size by computing the range using the variogram method for orientations. ii) During field measurement, the geospatial direction influences soil attribute values, so a shadowing calculation method was derived for quadratic weight determination. Then, the weight of the attribute value of known points can be assigned to meet the field conditions. Lastly, the model was evaluated using the root mean square error (RMSE). For the 2D space, the RMSE values of Kriging, RBF, and the proposed method are 6.09, 7.12, and 5.02, respectively. The R2 values of Kriging, RBF, and the proposed method are 0.871, 0.832, and 0.946, respectively. For the 3D space, the RMSE values of Kriging, RBF, and the proposed method are 2.65, 2.23, and 2.58, respectively. The R2 values of Kriging, RBF, and the proposed method are 0.934, 0.912, and 0.953, respectively. The resulting fitted model was relatively smooth and met experimental needs. Thus, we believe that the interpolation method can be applied as a new method to predict the distribution of soil pollutants.

Development of a speargun projectile penetrometer in soil

This study investigates the applicability of a speargun projectile penetrometer (SPP) for offshore site investigation purposes using experimental testing. The SPP can shoot penetrometers using an elastic/pneumatic force. The speargun is easy to handle, can generate significant kinetic energy, and requires a single operator to perform the test. A laboratory test platform was utilised to hold the SPP and ensure vertical launch, while a laser displacement sensor was employed to monitor the penetration depth and record the corresponding time history. The result demonstrated that the speargun-launched method achieves significantly higher embedment depth compared to an equivalent free-falling penetrometer. In particular, the new method produces sufficiently deep penetration in dense sand, thus overcoming the typical penetrometer tilting issue caused by shallow penetration. These findings provide a preliminary insight into the SPP, allowing for exploration beyond the boundaries of traditional penetrometers in laboratory testing and offshore site investigation.