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All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Schmid factor crack propagation and tracking crystallographic texture markers of microstructural condition in direct energy deposition additive manufacturing of Ti-6Al-4V

Metallic additive manufacturing (AM) provides a customizable and tailorable manufacturing process for new engineering designs and technologies. The greatest challenge currently facing metallic AM is maintaining control of microstructural evolution during solidification and any solid state phase transformations during the build process. Ti-6Al-4V has been extensively surveyed in this regard, with the potential solid state and solidification microstructures explored at length. In this study, we evaluate the applicability of previously determined crystallo- graphic markers of microstructural condition observed in electron beam melting powder bed fusion (PBF-EB) builds of Ti-6Al-4V in a directed energy deposition (DED) build process. The aim of this effort is to elucidate whether or not these specific crystallographic textures are useful tools for indicating microstructural conditions in AM variants beyond PBF-EB. Parent β-Ti grain size was determined to be directly related to α-Ti textures in the DED build process, and the solid state microstructural condition could be inferred from the intensity of specific α-Ti orientations. Qualitative trends on the as-solidified β-Ti grain size were also determined to be related to the presence of a fiber texture, and proposed as a marker for as-solidified grain size in any cubic metal melted by AM. Analysis of the DED Ti-6Al-4V build also demonstrated a near complete fracture of the build volume, suspected to originate from accumulated thermal stresses in the solid state. Crack propagation was found to only appreciably occur in regions of slow cooling with large α +β colonies. Schmid factors for the basal and prismatic α-Ti systems explained the observed crack pathway, including slower bifurcation in colonies with lower Schmid factors of both slip systems. Colony morphologies and localized equiaxed β-Ti solidification were also found to originate from build pauses during production and uneven heating of the build edges during deposition. Tailoring of DED Ti-6Al-4V microstructures with the insight gained here is proposed, along with cautionary insight on preventing unplanned build pauses to maintain an informed and controlled thermal environment for microstructural control.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Numerical investigations to identify environmental factors for field-scale reactive transport of pathogens at riverbank filtration sites

While induced bank filtration is a proven method for facilitating sustainable drinking water production, it is at risk from surface water contaminations (e.g., pathogens). Induced bank filtration and pathogen transport in groundwater have been studied extensively. However, long-term studies that consider real-world conditions are missing. These conditions include seasonal changes to environmental conditions and waterworks operations. Therefore, to analyze the effect of seasonal changes on the transport of human pathogenic viruses and their indicators in induced bank filtration, concentrations of adenoviruses and pathogen indicators were monitored over 16 months at an active bank filtration plant at the Rhine River, in Düsseldorf (Germany). Based on this data, a 2D groundwater model was created in PFLOTRAN that simulated flow, heat transport, conservative transport of chloride and the resulting electrical conductivity, reactive transport of oxygen and nitrate, and colloid-based transport of coliforms, somatic coliphages, and adenoviruses. The results show that reduced travel time was the key factor determining periods with a low removal of coliforms and somatic coliphages in the aquifer. Travel time was controlled by river level variations during rainy seasons, and the waterworks extraction rates during dry seasons. Further, for adenovirus transport, travel distance in the subsurface appeared to be the key factor, while travel time had no significant impact. Coliform removal increased when the colmation layer permeability decreased, while coliphage and adenovirus removal was unaffected by the colmation layer permeability. Seasonal changes in temperature and oxygen content did not significantly impact the removal of coliphages and adenoviruses in groundwater. Denitrifying conditions correlated with a lowered coliform removal, but the modelling could not establish a connection between denitrifying conditions and coliform removal. Our study showed that removal of pathogens and pathogen indicators at induced bank filtration plants varies greatly in time and space (e.g., for coliforms from 1 to 4 log-levels at 20m travel distance), and that adenovirus transport differs considerably from transport of coliforms and somatic coliphages.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

Analyzing the impact of design factors on solar module thermomechanical durability using interpretable machine learning techniques

Solar modules in utility-scale systems are expected to maintain decades of lifetime to rival conventional energy sources. However, cyclic thermomechanical loading often degrades their long-term performance, highlighting the importance of effective design to mitigate thermal expansion mismatches between module materials. Given the complex composition of solar modules, isolating the impact of individual components on overall durability remains a challenging task. In this work, we analyze a comprehensive data set that comprises bill-of-materials (BOM) and thermal cycling power loss from 251 distinct module designs to identify the predominant design factors and their impacts on the thermomechanical durability of modules. The methodology of our analysis combines machine learning modeling (random forest) and Shapley additive explanation (SHAP) to correlate design factors with power loss and interpret the model’s decision-making. The interpretation reveals that silicon type (monocrystalline or polycrystalline), encapsulant thickness, busbar numbers, and wafer thickness predominantly influence the degradation. With lower power loss of around 0.6% on average in the SHAP analysis, monocrystalline cells present better durability than polycrystalline cells. This finding is further substantiated by statistical testing on our raw data set. The SHAP analysis also demonstrates that while thicker encapsulants lead to reduced power loss, further increasing their thickness over around 0.6 to 0.7 mm does not yield additional benefits, particularly for the front side one. In addition, other important BOM features such as the number of busbars are analyzed. This study provides a blueprint for utilizing explainable machine learning techniques in a complex material system and can potentially guide future research on optimizing the design of solar modules.

14 SOLAR ENERGY↗
DOE OSTI2018

Factors affecting relative humidity and its relationship with the long-term variation of fog-haze events in the Yangtze River Delta

Relative humidity (RH) is one of the most important parameters in the study of fog-haze. This paper first estimates the contributions of the key quantities (temperature, water vapor, air pollutant) and their combinations to the relative change of RH, and then investigates the relationships of RH with the long-term variation of haze and fog days based on the meteorological data in the Yangtze River Delta over the period 1970-2010.The main conclusions are as follows. (1) Temperature is the foremost factor influencing RH, with the effect of specific humidity and direct contribution of air pollutant being second and third. (2) RH shows a prominent descending trend in the Yangtze River Delta, due to global warming and the ‘analogous heat island effect’ (AHIE). (3) Decreasing RH was responsible for the reduction of fog days. The AHIE can explain the phenomenon in which fog days in metropolises are less than in small cities. (4) Granger causality analysis of inter-annual variation further shows that increasing aerosol loading Ganger-causes the increasing haze days, rather than meteorological parameters such as RH. High RH would enhance hygroscopic growth of particle and then suppress the planet boundary layer height (PBLH) and lead to more haze days, lower PBLH further increases aerosols and RH, this positive feedback mechanism can be established under the condition of aerosol loading being relatively stable and beyond the threshold for haze formation. (5) If aerosol emissions maintain the status quo, climate cooling would result in serious fog-haze events occurring more frequently in Yangtze River Delta. The research provide a scientific basis for understanding the influence of meteorological factors on RH and the connection between the variation of long term fog-haze days and RH under the background of climate change.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Identification of cathepsin B as a novel target of hypoxia-inducible factor-1-alpha in HepG2 cells

Highlights: • Cathepsin B (CTSB) is a novel target gene of hypoxia-inducible factor-1-alpha (HIF-1α). • CTSB mRNA and protein levels can be up-regulated in a HIF-1α-dependent manner. • CTSB promoter activity can be elevated by the HIF-1α protein. • HIF-1α protein binds the CTSB promoter directly. Hypoxia-inducible factor-1-alpha (HIF-1α) activates the transcription of many genes that code for proteins involved in angiogenesis, glucose metabolism, cell proliferation/survival, and invasion/metastasis. However, the mechanisms between HIF-1 and its downstream target genes are still poorly understood. Our experimental results had shown that nuclear HIF-1α proteins were significantly induced after HepG2 cells treatment with 1% O{sub 2} for 6 h and reached the peak expression level in 24 h. Meanwhile, the results of RT-qPCR and Western-blotting showed that HIF-1α and cathepsin B (CTSB) expressions increased with a similar pattern in response to hypoxia in the HepG2 cells. Additionally, based on bioinformatics analysis, we identified a hypoxia response element in the CTSB promoter, indicating a possible association between HIF-1α and CTSB. Moreover, luciferase assay was performed to reflect the transcriptional activity mediated through the HIF-1α binding HRE within the CTSB promoter. Furthermore, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (CHIP) revealed a specific HIF-1α binding activity to the CTSB gene promoter. For the first time, we demonstrated that CTSB is a new HIF-1α-target gene. We believe these findings will contribute to the research and development of neoplasm-targeted therapies.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

A negative feedback loop between nuclear factor 90 (NF90) and an anti-oncogenic microRNA, miR-7

Highlights: • miR-7, an anti-oncogenic miRNA, represses NF90 at the mRNA level. • The coding region of the NF90 mRNA is directly targeted by miR-7. • A rise in NF90 is attributed to negative feedback between NF90 and miR-7 in tumors. Alterations in microRNAs (miRNAs) levels deeply correlate with tumorigenesis. However, the molecular mechanism for the regulation of the miRNA production in tumors is not fully understood. We previously reported that downregulation of miR-7, which is an anti-oncogenic miRNA, was caused by overexpression of the nuclear factor 90 (NF90)-nuclear factor 45 (NF45) complex through the binding of double-stranded (ds) RNA-binding proteins to primary miR-7, resulting in promotion of tumorigenesis (Higuchi et al 2016). During this study, we found that the level of NF90 protein was dramatically decreased by overexpression of miR-7. Interestingly, the miR-7-mediated reduction in NF90 family proteins was only observed in NF90 protein, but not in NF110 protein, which is a longer form of the NF90 gene. Luciferase reporter analysis indicated that the overexpression of miR-7 significantly repressed the luciferase activity in the coding region of NF90 mRNA harboring a predicted target sequence of miR-7. The luciferase activity of the reporter vector, which has a mutated miR-7 target site in the coding region, was the same in the control and miR-7 overexpressed cells. Furthermore, the translation of TARGET-tagged NF90 mRNA without the 3′UTR of the NF90 mRNA was inhibited by the overexpression of miR-7. These results imply that miR-7 suppresses NF90 at the protein level through the binding of miR-7 to the complementary site of the seed sequence in the coding region of the NF90 mRNA. We further confirmed increased endogenous NF90 protein levels in SK-N-SH cells transfected with antisense oligonucleotides targeting miR-7, indicating that miR-7-mediated translational repression of NF90 is a physiological event. Taken together with our previous findings (Higuchi et al 2016), it suggests that the level of NF90 is increased by a negative feedback loop between NF90 and miR-7 in tumor tissues under physiological conditions.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Effect of growth differentiation factor-15 secreted by human umbilical cord blood-derived mesenchymal stem cells on amyloid beta levels in in vitro and in vivo models of Alzheimer's disease

Highlights: • Paracrine action of hUCB-MSCs enhances Aβ clearance through microglial modulation. • GDF-15 secreted from hUCB-MSCs promotes the decrease of Aβ levels via enhancing IDE expression in microglia. • TGFβRII is involved in GDF-15-enhanced IDE expression in microglia. Alzheimer's disease (AD), which is the most common progressive neurodegenerative disease, causes learning and memory impairment. The pathological progress of AD can derive from imbalanced homeostasis of amyloid beta (Aβ) in the brain. In such cases, microglia play important roles in regulating the brain Aβ levels. In the present study, we found that human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) can increase, through paracrine action, the ability of microglial cells to clear Aβ. In order to identify the associated paracrine factors, a secretome of hUCB-MSCs co-cultured with Aβ-treated BV2 microglial cells was analyzed using a human cytokine protein array. As a result, growth differentiation factor-15 (GDF-15) was identified as a predominant candidate, and its association with Aβ clearance by microglial cells was investigated in vitro and in a 5XFAD mouse model. When Aβ-treated BV2 cells were treated with exogenous recombinant GDF-15, the Aβ levels in the culture medium decreased. Moreover, GDF-15 injection in the brain parenchyma of 5XFAD mice also led to decrease in Aβ plaques. In contrast, co-culture of BV2 cells and hUCB-MSCs treated with GDF-15-specific siRNA did not influence the Aβ levels in the culture medium. To elucidate how these phenomena are related, we confirmed that GDF-15 specifically increases insulin-degrading enzyme (IDE) expression in microglial cells through TGFβ receptor type II (TGFβRII), both in vitro and in vivo. These findings suggest that hUCB-MSCs promote the Aβ clearance ability of microglial cells through regulation of GDF-15 secretion, thus elucidating a therapeutic mechanism for AD.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors

Suicide is a leading cause of death worldwide, and non-fatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods: We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium. The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via mtCOJO, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders and other known risk factors. Results: Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with non-psychiatric traits remained largely unchanged. Conclusions: Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Understanding of the factors slowing down metakaolin reaction in limestone calcined clay cement (LC3) at late ages

Factors which could explain the slowing down of the metakaolin reaction in LC{sup 3} blends are investigated. Portlandite availability and the presence of aluminium ions in the pore solution are shown not to be limiting factors. Hydrates can only precipitate in solution filled pores. Internal relative humidity measurements indicate that at 28 days solution is present only in pores with radii below 13 nm. An enhancement of metakaolin reaction was obtained at late ages when the larger capillaries are filled with solution. The lower limit of the water filled pores was more difficult to analyse since there is a lack of precision in determining interfacial energies of hydrates and pore solution of the system. However, this study gives an indication of order of magnitude where the growth of hydrates could be slowed down.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Relationships between physical–geographical factors and soil degradation on agricultural land

Highlights: • Connection of soil degradation to seven physical-geographical variables was revealed. • New method of threshold data analysis was proposed. • Precise treshold values where soil degradation starts and ends were revealed. • Study area covered the entire area of Czech agricultural land – 13027 cadastres (78,866 km{sup 2}). It is a well-known fact that soil degradation is dramatically increasing and currently threatens agricultural soils all around the world. The objective of this study was to reveal the possible connection between soil degradation and seven physical-geographical factors - slope steepness, altitude, elevation differences, rainfall, temperature, soil texture and solar radiation – in the form of threshold values (if these exist), where soil degradation begins and ends. The analysis involved the whole area of the Czech Republic which consists of 13,027 cadasters (78,866 km{sup 2}). The greatest total degradation threat occurs in areas with slope steepness >7 degrees, average annual temperature 10.54, altitude >766 m a.s.l. Similarly, the results for water erosion, wind erosion, soil compaction, loss of organic matter, acidification and heavy metal contamination were processed. The results enable us to identify the relationships of different levels of threats which could consequently be used in various ways – for classification of threatened areas, for more effective implementation of anti-degradation measures, or purely for a better understanding of the role of physical geographical factors in soil degradation in the Czech Republic, and thus could increase the chances of reducing vulnerability to land degradation not only in the Czech Republic.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

National and subnational mortality and disability-adjusted life years (DALYs) attributable to 17 occupational risk factors in Iran, 1990–2015

Highlights: • Mortality and morbidity from 17 occupational risks in Iran, 1990–2015 were estimated. • During 1990–2015, national DALYs from occupational risks increased by 65%. • During 1990–2015, the share of women in the attributable DALYs rose from 13% to 20%. • Proportion of YLLs in national DALYs due to occupational risks in 2015 was 23%. • Spatial inequality in the attributable DALY rate decreased from 1990 to 2015. We estimated age-sex specific and cause-specific mortality, years of life lost due to premature mortality (YLLs), years lived with disability (YLDs) and disability-adjusted life years (DALYs) attributable to 17 individual occupational risks in Iran at the national and subnational levels in 1990–2015 based on the Global Burden of Disease Study 2015 (GBD 2015). The burden of disease attributable to occupational risk factors was calculated using the comparative risk assessment methodology based on 10 outcomes and 21 risk-outcome pairs. The temporal changes in the attributable burden of disease were decomposed into the contribution of population growth, population ageing, risk-deleted DALY rate, and risk exposure. National DALYs attributable to occupational risks at the national level in 1990, 2005, and 2015 were 138,210 (95% uncertainty interval 64,429–223,028), 193,243 (91,645–310,281), and 228,310 (106,782–371,709), respectively indicating a total increase of 65% (65–67) during the study period. Between 1990 and 2015, the share of the attributable DALYs for women rose by 55% (51–58) from 13% (12–14) to 20% (19–21). The proportion of YLLs in national DALYs attributable to occupational risks during the study period slightly decreased from 24% in 1990 to 23% in 2015. The five occupational risks with the highest contributions in the national attributable DALYs in 2015 were ergonomic factors (107,490), noise (52,122), exposure to particulate matter, gases, and fumes (26,847), asthmagens (19,347), and exposure to asbestos (7842). From 1990 to 2015, the increase in total DALYs attributable to occupational carcinogens (112%) was higher than that for other occupational risks. During the study period, changes in risk deleted DALY rate and risk exposure led to decreases in total DALYs attributable to occupational risks by 14% and 30%, respectively. Based on the Gini coefficient, spatial inequality in DALY rate attributable to occupational risks at the provincial level decreased during 1990–2015. A comprehensive plan for management of exposure to occupational risks, especially occupational carcinogens can cause an important effect for control of the increasing trend of occupational health losses.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Impact of meteorological factors on mumps and potential effect modifiers: An analysis of 10 cities in Guangxi, Southern China

Highlights: • A total of 183,341 cases from 10 cities, daily weather data and 10 socioeconomic factors were included in the analysis. • Mean temperature and wind velocity are associated with the elevated risks of mumps incidence. • Male and adolescent aged 5–14 y are the most sensitive population to extreme weather conditions. • Several socioeconomic indicators may have a certain degree of modification on the climate-related incidence of mumps. In the current context of global climate change, understanding the impact of climate on respiratory infectious diseases such as mumps and the potential modified factors is crucial, especially in developing countries. However, research on the climate-related incidence of mumps is rare, inconsistent and mainly limited to a single city or region.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Climatic factors and long-term trends of influenza-like illness rates in The Netherlands, 1970–2016

Highlights: • We studied the link between climatic factors and influenza-like illness (ILI) rate. • In the Netherlands, ILI rates dropped during 1970–2003, then started to rise again. • Weekly ILI count was inversely associated with humidity and temperature. • The early 2000s were a trend-reversal point for the climatic time series as well. • Seasonal average ILI rates and humidity (or temperature) were inversely correlated. Climatic factors affect the survival and transmissibility of respiratory viruses causing influenza-like illness (ILI), and we hypothesized that changes in absolute humidity and temperature may affect long-term trends of ILI incidence rate in temperate countries. We tested this hypothesis using ILI and meteorological time series in the Netherlands for the period 1970–2016.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Walking on the dark side: Anthropogenic factors limit suitable habitat for gray wolf ( Canis lupus ) in a large natural area covering Belarus and Ukraine

Due to successful conservation initiatives and legislations, the grey wolf (Canis lupus) is recolonising its historic range in Europe. However, wolves have never been extirpated across large areas in Eastern Europe but are often constrained to remote and inaccessible places due to centuries of persecution. This study aimed to identify the potentially suitable wolf habitats in Polesia, a massive cross-border lowland region extending over southern Belarus and northern Ukraine, which are often neglected in large carnivore studies at the continental scale. We hypothesized that anthropogenic rather than environmental factors govern wolf habitat suitability. We used a dataset of 4191 GPS locations obtained from radio-collared wolves (n = 26) and confirmed observations (n = 231) during 2014–2021 and applied maximum entropy method to estimate relative habitat suitability for wolves in Polesia. Artificial light at night (ALAN), proportion of cropland and tree cover were the most important factors affecting wolf habitat suitability. Road densities contributed poorly to predicting habitat suitability for wolves. Our models predicted a quarter of Polesia as suitable habitat and revealed priority areas connecting the important source populations in the Chornobyl Exclusion Zone in the east and the Bialowieza Forest in the west and thus essential for long-term wolf conservation. Our results provide the bases for effective, long-term wolf monitoring and management programs in both Belarus and Ukraine. However, national and transboundary wolf management in Polesia has been extremely challenging since 2022 due to the ongoing war and subsequent habitat degradation in this part of Europe.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Modeling and mitigating airborne pathogen risk factors in school buses

Computational fluid dynamics (CFD) models were developed to simulate the impact of different ventilation scenarios on airborne exposure risks in a 72-passenger school bus. Here, scenarios and factors that were investigated included a moving vs. stationary bus, impacts of a heating unit within the bus, and impacts of alternative ventilation scenarios with different combinations of openings (e.g., windows, door, emergency hatch). Results of the simulations showed that when the bus was stationary, use of the heater increased receptor concentrations unless there was another opening. When the bus was moving, simulations with at least two sets of openings separated from each other in the forward and aft directions produced a through-flow condition that reduced concentrations via dilution from outside air by a factor of ten or more. A single opening in a moving bus generally increased concentrations throughout the cabin due to increased mixing with minimal ventilation. The cumulative exposure risk (time-averaged concentrations) was found to be inversely correlated to the air exchange rate. Stationary and moving-bus scenarios that yielded above ~20 air changes per hour resulted in the lowest cumulative exposures. Recommendations from this study were implemented in new safety and operating procedures by the Albuquerque Public Schools Transportation Center.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Skin factor and potential formation damage from chemical and mechanical processes in a naturally fractured carbonate aquifer with implications to CO 2 sequestration

Here, in this study, we investigate formation damage due to acidization and water injection tests into the naturally fractured carbonate Middle Duperow Formation at Kevin Dome, Montana, potentially diminishing the chance of a future successful Geological Carbon Sequestration (GCS) project. Multiple well-test analytical models, correlated with core description and lithology data, are used to determine flow behavior and communication between the water injection interval and surrounding formations. An improved three-dimensional (3D) geologic model with dual-continuum matrix and fracture properties is constructed based on most recent seismic, core, and water sample measurements. Brine injection is simulated to verify the interpretation from the analytical models, followed by CO 2 injection simulation. Geochemical calculations are performed to understand the in-situ processes that led to formation damage. Our findings suggest: (1) there are two possible scenarios that could lead to a positive total effective skin factor and permeability decline: partial penetration and formation damage; (2) analytical models indicate a positive total skin factor, contradicting results of a previous study suggesting that the well was mildly stimulated; (3) numerical simulation supports the formation damage hypothesis by matching the pressure buildup observed during the latter two brine injection tests; (4) several mechanical and chemical processes may have occurred during injection to clog the matrix/fracture system: anhydrite fines migration and/or calcite precipitation. We then make preventative suggestions for future GCS projects into carbonate reservoirs and remediation recommendations for GCS operation at the Kevin Dome.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Clinical and Dosimetric Factors Predicting Grade ≥2 Radiation Pneumonitis After Postoperative Radiotherapy for Patients With Non-Small Cell Lung Carcinoma

To identify clinical and dosimetric factors that would predict grade ≥2 radiation pneumonitis (RP) for patients undergoing postoperative radiation therapy (PORT) for non-small cell lung cancer (NSCLC); and to use the factors identified to generate a predictive model to quantify risk of RP in such patients.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2021

Factors controlling pore network development of thermally mature Early Palaeozoic mudstones from the Baltic Basin (N Poland)

Understanding the formation of pore space, especially in low porosity shales (as source rocks and as unconventional resources), is critical to the oil and gas industry, since pores control the space available for hydrocarbon and participate in hydrocarbon transport. We examined 87 Ordovician and Silurian mudstone samples collected from four wells located in the Pomeranian part of the Baltic Basin (northern Poland), one of the primary Polish targets for hydrocarbon exploration. These samples represent the Pelplin, the Paslek, the Jantar, the Prabuty, and the Sasino Formations, which still requires more detailed porosity studies. Our study aimed to identify factors controlling porosity development, by applying bulk techniques (organic petrology and TOC analyses, quantitative mineralogy, and porosimetry) as well as nano- to microscale techniques (thin section petrography, electron microscopy). The studied samples are mainly argillaceous mudstones. The results of porosimetry measurements, combined with image analysis, indicate that the pores of all studied rocks are dominated by micropores (pores < 2 nm in diameter), mesopores (2-50 nm in diameter) and small macropores. The SEM images showed three main pore types: a) voids related to clay mineral aggregates, b) pores inside organic matter particles, and c) pores between other mineral grains. In the Jantar and Sasino mudstones, the organic matter content and its thermal maturity control porosity. The occurrence of solid bitumen in the rocks from these formations reduces samples’ mesoporosity because of the pore-clogging effect. In contrast, in the Paslek and Prabuty Formations, there is low organic matter content and specific surface area and the volume of mesopores increase with clay minerals content. In the Pelplin mudstones, there are no prevailing factors controlling porosity. As a result, we suggest that a combination of SEM image analysis and dual liquid porosity (DLP) measurements is a powerful method to assess porosity available for petroleum flow in mudstones.

03 NATURAL GAS↗