113 research outputs found

    Impact of Inorganically Bound Sulfur on Late Shale Gas Generation

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    Nonisothermal, confined pyrolysis was applied to a mature shale sample from the Ordovician Salgan Formation in Tarim Basin, northwest China. Experiments were conducted using gold-tubes with added water at a very slow heating rate (2 °C/h) and end temperatures between 336 and 600 °C. To investigate the influence of inorganically bound sulfur on the generation of gases and to consider the geological occurrence of sulfur-containing minerals, such as prevalent pyrite in shales, the experiments were carried out with and without admixtures of MgSO<sub>4</sub>, CaSO<sub>4</sub>, and pyrite. High amounts of methane along with lower amounts of wet gases were formed from highly mature shale without minerals added, demonstrating a huge late gas generation potential at post peak-oil window maturities. In the experiments with added sulfates and pyrite, all organic gases were consumed in varying proportions, resulting in different chemical and stable carbon isotopic compositions. Pyrite treatment affects wet gas (C<sub>2</sub>–C<sub>5</sub>) evolution directly, but it affects methane (C<sub>1</sub>) evolution indirectly. In contrast, sulfate treatments affect C<sub>1</sub>–C<sub>5</sub> evolution directly. The cumulative yield ratio of CO<sub>2</sub>/H<sub>2</sub>S indicates that pyrite impacts on the hydrocarbon gas generation through low valence sulfur such as S<sup>0</sup> or others, which are associated with H<sub>2</sub>S generation. In the pyrite series, the smooth increase in ethane yield at temperatures exceeding 504 °C, together with a concomitant stable carbon isotope reversal, demonstrates a new origin for ethane at high temperatures. The isotopic reversal may come from reactions between water and solid kerogen/coke/pyrobitumen. Isotopic reversal of ethane occurs only in the control and pyrite series but not in the sulfate treatments. This provides evidence that anoxic conditions are required. Thus, one can expect to encounter isotopic reversals in high maturity, unconventional gas shale environments in the presence of pyrite

    Exploring Open-Vocabulary Semantic Segmentation without Human Labels

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    Semantic segmentation is a crucial task in computer vision that involves segmenting images into semantically meaningful regions at the pixel level. However, existing approaches often rely on expensive human annotations as supervision for model training, limiting their scalability to large, unlabeled datasets. To address this challenge, we present ZeroSeg, a novel method that leverages the existing pretrained vision-language (VL) model (e.g. CLIP) to train open-vocabulary zero-shot semantic segmentation models. Although acquired extensive knowledge of visual concepts, it is non-trivial to exploit knowledge from these VL models to the task of semantic segmentation, as they are usually trained at an image level. ZeroSeg overcomes this by distilling the visual concepts learned by VL models into a set of segment tokens, each summarizing a localized region of the target image. We evaluate ZeroSeg on multiple popular segmentation benchmarks, including PASCAL VOC 2012, PASCAL Context, and COCO, in a zero-shot manner (i.e., no training or adaption on target segmentation datasets). Our approach achieves state-of-the-art performance when compared to other zero-shot segmentation methods under the same training data, while also performing competitively compared to strongly supervised methods. Finally, we also demonstrated the effectiveness of ZeroSeg on open-vocabulary segmentation, through both human studies and qualitative visualizations

    EgoObjects: A Large-Scale Egocentric Dataset for Fine-Grained Object Understanding

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    Object understanding in egocentric visual data is arguably a fundamental research topic in egocentric vision. However, existing object datasets are either non-egocentric or have limitations in object categories, visual content, and annotation granularities. In this work, we introduce EgoObjects, a large-scale egocentric dataset for fine-grained object understanding. Its Pilot version contains over 9K videos collected by 250 participants from 50+ countries using 4 wearable devices, and over 650K object annotations from 368 object categories. Unlike prior datasets containing only object category labels, EgoObjects also annotates each object with an instance-level identifier, and includes over 14K unique object instances. EgoObjects was designed to capture the same object under diverse background complexities, surrounding objects, distance, lighting and camera motion. In parallel to the data collection, we conducted data annotation by developing a multi-stage federated annotation process to accommodate the growing nature of the dataset. To bootstrap the research on EgoObjects, we present a suite of 4 benchmark tasks around the egocentric object understanding, including a novel instance level- and the classical category level object detection. Moreover, we also introduce 2 novel continual learning object detection tasks. The dataset and API are available at https://github.com/facebookresearch/EgoObjects.Comment: ICCV 2023 final version and supplement. See more details in project page: https://github.com/facebookresearch/EgoObject

    Influence of paste thickness on the coated aggregates on properties of high-density sulphoaluminate cement concrete

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    An improved method for the densified mixture design algorithm and Fuller curve were used to design high-density sulphoaluminate cement concrete (HDSC). The performance of HDSC is significantly influenced by the paste thickness on the coated aggregates. Sulphoaluminate cement concrete mixtures containing aggregates coated with 3 different paste thickness of t=10μm, 20μm, and 30μm and water-binder ratios (W/B) of 0.25, 0.30 and 0.35 were prepared. The results of experiments show that paste thickness on the coated aggregates significantly influences the mechanical properties and durability of HDSC. With the increase of paste thickness, the compressive strength is increased, but the electrical resistivity is decreased, particularly at the early ages of 1 and 3 days. The sulfate corrosion resistance coefficients of HDSC are larger than 1.0, the total porosity can be less than 7%, and the micropore (i.e. with pore size less than 20nm) can be larger than 70%

    A Radiomics Approach Based on Follow-Up CT for Pathological Subtypes Classification of Pulmonary Ground Glass Nodules

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    Preoperative, non-invasive, and accurate identification of the pathological subtypes of pulmonary ground glass nodules (GGNs) play an important role in the precise selection of clinical surgical operations and individualized treatment plans. Efforts have been made for the classification of pathological subtypes of GGNs, but most existing methods focus on benign or malignant diagnosis of GGNs by means of a one-time computed tomography image (CTI), which fails to capture the nodule development based on follow-up CTI. In this paper, a novel method for subtype classification based on follow-up CTIs is presented as a viable option to the existing one-time CTI-based approach. A total of 383 follow-up CTIs with GGNs from 146 patients was collected and retrospectively labeled via posterior surgical pathology. Feature extraction is performed individually to the follow-up CTIs. The extracted feature differences were represented as a vector, which was then used to construct a set of vectors for all the patients. Finally, a subspace K-nearest neighbor classifier was built to predict the pathological subtypes of GGNs. Experimental validation confirmed the efficacy of the new method over the existing method. Results showed that the accuracy of the new method could reach 72.5%, while the existing methods had an upper bound of 67.5% accuracy. Subsequent three-category comparison experiments were also performed to demonstrate that the new method could increase the accuracy up to 21.33% compared to the existing methods that use one-time CTI

    Dehydration kinetics of antibiotic fermentation residues by dehydration agents at room temperature

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    Harmless disposal of antibiotics fermentation residues (AFRs) is required due to the risk of inducing drug-resistant via the residual antibiotics. AFRs are rich in colloidal water to be hardly removed by mechanical methods, leading to the energy-intensive dewatering. Dehydration agents (DAs) can be used to treat the wet AFRs, in which colloidal water was transferred into the hydrate of DA and formed solid AFRs-DA mixture at room temperature. In this article, the dehydration kinetics of AFRs was investigated systematically. The results show that the dehydration followed the first-order kinetic equation and the main influences were temperature, feed ratio, and the particle size of DA. In addition, the quantitative relationship of kinetic parameters with the feed ratio and temperature were established, providing the basic data for further reducing the energy consumption of AFRs disposal

    Effects of Heavy Metal Pollution in Soil of Coal Gangue Area on Germination and Seedlings of Typical Remediation Plants

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    The problem of soil heavy metal pollution caused by coal gangue accumulation areas is becoming more and more serious. In situ plant remediation technology has become one of the most promising methods to solve heavy metal soil pollution due to its advantages of the green economy. In this experiment, the characteristics of heavy metal pollution in the shallow soil (vertical depth 0~20 cm) 300 m outside the square circle of a typical coal gangue accumulation area in the Fengfeng Mining Area of Hebei Province, China were used as the prototype. Alfalfa and ryegrass were selected as the test plants. Pot experiments were carried out at different heavy metal concentrations (Cu:14/64/100 mg/kg, Pb:15/38/170 mg/kg, Cd:1/4/8 mg/kg) levels to study and reveal the effects of single and compound soil heavy metal pollution on seed germination and seedling growth characteristics of alfalfa and ryegrass. The results showed that: (1) Under the condition of single Cd pollution, the germination index of alfalfa seeds and the germination potential of ryegrass seeds show a trend of “low concentration promotion and high concentration inhibition”. Under the condition of single Pb and Cu pollution in soil, the germination indices show obvious inhibition and damage effect; that is, with an increase in concentration, the germination rate, germination potential, germination potential, and vigor index show a decreasing trend. When Pb is 170 mg/kg or Cu is 100 mg/kg or Cd is 8 mg/kg, the inhibitory effect on seed germination and seedling growth of the two plants is the most harmful. (2) Due to the different concentrations of heavy metal combined pollution, there are synergistic or antagonistic effects between Cu, Pb and Cd in soil on alfalfa and ryegrass. That is to say, under low concentrations of heavy metal pollution, the inhibitory effect of combined stress is greater than that of single stress, and under high concentration of heavy metal pollution, the inhibitory effect of combined stress is less than that of single stress. (3) Whether in the single pollution or combined pollution of soil, ryegrass is always more tolerant than alfalfa, indicating that ryegrass has more potential for remediation

    The Identification of APOBEC3G as a Potential Prognostic Biomarker in Acute Myeloid Leukemia and a Possible Drug Target for Crotonoside

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    The apolipoprotein B mRNA editing enzyme catalytic subunit 3G (APOBEC3G) converts cytosine to uracil in DNA/RNA. Its role in resisting viral invasion has been well documented. However, its expression pattern and potential function in AML remain unclear. In this study, we carried out a bioinformatics analysis and revealed that the expression of APOBEC3G was significantly upregulated in AML, and high expression of APOBEC3G was significantly associated with short overall survival (OS). APOBEC3G expression was especially increased in non-M3AML, and correlated with the unfavorable cytogenetic risks. Additionally, Cox regression analyses indicated APOBEC3G is a hazard factor that cannot be ignored for OS of AML patients. In molecular docking simulations, the natural product crotonoside was found to interact well with APOBEC3G. The expression of APOBEC3G is the highest in KG-1 cells, and the treatment with crotonoside can reduce the expression of APOBEC3G. Crotonoside can inhibit the viability of different AML cells in vitro, arrest KG-1 and MV-4-11 cells in the S phase of the cell cycle and affect the expression of cycle-related proteins, and induce cell apoptosis. Therefore, APOBEC3G could be a potential drug target of crotonoside, and crotonoside can be considered as a lead compound for APOBEC3G inhibition in non-M3 AML
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