Dominant controls on organic-rich shale deposition: Geochemical evidences from the Marcellus Shale in the Appalachian basin

This dissertation presents new results of the linkages between primary productivity, bottom water redox conditions and clastic input associated with the Acadian orogeny of the Marcellus Shale.;Chapter 1 compares the isotopic and geochemical characteristics of sediments of a liquids-prone well (WV-7) in Wetzel County with a gas-prone well (WV-6) in Monongalia County, northern West Virginia. The difference in organic carbon isotopes indicates that the dominant organic matter preserved in each core is different: delta13Corg values are lighter on average in WV-6 compared with WV-7. A possible explanation is that a larger fraction of terrestrial organic matter was preserved in the WV-6 core, whereas WV-7 may contain a greater percentage of marine organic matter. Clastic-influx proxies (e.g. Ti/Al, Ca/Al and Mg/Al) also suggest that the WV-6 core site received a higher sediment input compared to WV-7, consistent with a more proximal location to dry land and the delivery of greater amounts of terrestrial organic matter. Depleted delta13C carb values, low concentrations of redox sensitive elements (e.g. V, Cr, Ni and U), and high variability delta15N values in the WV-6 core all suggest the presence of higher dissolved oxygen concentration and short term shifts in an oxic/anoxic boundary near the sediment-water interface during deposition. This indicates that the depositional conditions were favorable for the accumulation of predominantly gas-prone Type III kerogen in the Marcellus Shale at the WV-6 site. In contrast, the Marcellus Shale at the WV-7 site was deposited in a more distal area that received a low terrestrial sediment supply, organic matter primarily derived from marine algae, and bottom water conditions that were dominantly anoxic. Such conditions were favorable for the accumulation of Type II kerogen that has a greater capacity to generate liquid hydrocarbons.;Chapter 2 employs geochemical, isotopic in combination with petrographic analyses from a core of the Marcellus Shale obtained from Greene County, Pennsylvania, to understand the dominant controls on organic matter deposition in the black shale study units. This study suggests that the regeneration of nutrients, such as nitrogen (N) and phosphorous (P), may have played a key role in the formation of organic carbon (OC)-rich intervals in the Marcellus Shale. The ratios of Corg/Nbulk and Corg/P tot are significantly higher in the OC-rich zone of the core (i.e., defined as TOC \u3e 4% and located between 2393 and 2406.5 m depth). The high Corg/Ptot and Corg/Nbulk ratios of the preserved organic matter may reflect the release of N and P by microbial processes, indicating the recycling of nutrients during deposition of the OC-rich interval. In addition, our data show a positive relationships between the Corg/Ptot and Corg/Nbulk ratios and the organic carbon content, which indicate that the recycled nutrients may have promoted primary productivity, resulting in higher OC accumulation in some intervals. The geochemical and stable isotopic results also suggest that the alternating redox conditions in the water mass were favorable for nutrient regeneration. Highly variable trace metal concentrations (e.g., U, Mo, V) in the OC-rich zone and a wide range of delta15N and delta 34Spyr values towards the top of the OC-rich zone suggest fluctuations between anoxic and suboxic water conditions. Finally, sedimentary features and agglutinated benthic foraminifera in the OC-rich zone support the existence of short-term fluctuations between suboxic and anoxic conditions near the sediment-water interface.;Chapter 3 reports trace and rare earth elements (REE) of the samples collected from a 30-m core of the Marcellus Shale obtained from Greene County, southwestern Pennsylvania. This study provides the direct links between organic matter enrichment trends in the Marcellus Shale with the Acadian orogeny. The Acadian orogen has been recognized as a main sediment source for the Marcellus Shale. Synthesis of tectonic history and recent ash bed geochronology, reveals that deposition of the organic carbon-rich (OR) zone (characterized by TOC \u3e4%; located between 2393 m and 2406.5 m core depth) in the studied Marcellus Shale core was coincident with tectonically active and magmatic quiescent period of the Acadian orogeny (ca. 395--380 Ma). This time also corresponds to the period when mountain building in the Acadian orogen was at its highest rates. The light rare earth (LREE) and selected trace elemental (e.g., Ta, Cs) composition of the OR zone sediments is similar to that of the bulk continental crust, supporting the lack of magmatic activity in the source area (i.e. Acadian orogen). In contrast, subsequent deposition of the organic carbon-poor (OP) sediments (characterized by TOC \u3c4%; located between 2376 m and 2393 m core depth) in the upper Marcellus Shale occurred synchronously with a magmatic active phase (ca. 380--370 Ma) during the Acadian orogeny. The OP zone sediments have LREE and trace elements composition similar to that of the upper continental crust. (Abstract shortened by UMI.)

Omni-Line-of-Sight Imaging for Holistic Shape Reconstruction

We introduce Omni-LOS, a neural computational imaging method for conducting holistic shape reconstruction (HSR) of complex objects utilizing a Single-Photon Avalanche Diode (SPAD)-based time-of-flight sensor. As illustrated in Fig. 1, our method enables new capabilities to reconstruct near-$360^\circ$ surrounding geometry of an object from a single scan spot. In such a scenario, traditional line-of-sight (LOS) imaging methods only see the front part of the object and typically fail to recover the occluded back regions. Inspired by recent advances of non-line-of-sight (NLOS) imaging techniques which have demonstrated great power to reconstruct occluded objects, Omni-LOS marries LOS and NLOS together, leveraging their complementary advantages to jointly recover the holistic shape of the object from a single scan position. The core of our method is to put the object nearby diffuse walls and augment the LOS scan in the front view with the NLOS scans from the surrounding walls, which serve as virtual ``mirrors'' to trap lights toward the object. Instead of separately recovering the LOS and NLOS signals, we adopt an implicit neural network to represent the object, analogous to NeRF and NeTF. While transients are measured along straight rays in LOS but over the spherical wavefronts in NLOS, we derive differentiable ray propagation models to simultaneously model both types of transient measurements so that the NLOS reconstruction also takes into account the direct LOS measurements and vice versa. We further develop a proof-of-concept Omni-LOS hardware prototype for real-world validation. Comprehensive experiments on various wall settings demonstrate that Omni-LOS successfully resolves shape ambiguities caused by occlusions, achieves high-fidelity 3D scan quality, and manages to recover objects of various scales and complexity

Application and Development Progress of Cr-Based Surface Coatings in Nuclear Fuel Element: I. Selection, Preparation, and Characteristics of Coating Materials

To cope with the shortcomings of nuclear fuel design exposed during the Fukushima Nuclear Accident, researchers around the world have been directing their studies towards accident-tolerant fuel (ATF), which can improve the safety of fuel elements. Among the several ATF cladding concepts, surface coatings comprise the most promising strategy to be specifically applied in engineering applications in a short period. This review presents a comprehensive introduction to the latest progress in the development of Cr-based surface coatings based on zirconium alloys. Part I of the review is a retrospective look at the application status of zirconium alloy cladding, as well as the development of ATF cladding. Following this, the review focuses on the selection process of ATF coating materials, along with the advantages and disadvantages of the current mainstream preparation methods of Cr-based coatings worldwide. Finally, the characteristics of the coatings obtained through each method are summarized according to some conventional performance evaluations or investigations of the claddings. Overall, this review can help assist readers in getting a thorough understanding of the selection principle of ATF coating materials and their preparation processes

Recent Advances in Applications of Carbon Nanotubes for Desalination: A Review

As a sustainable, cost-effective and energy-efficient method, membranes are becoming a progressively vital technique to solve the problem of the scarcity of freshwater resources. With these critical advantages, carbon nanotubes (CNTs) have great potential for membrane desalination given their high aspect ratio, large surface area, high mechanical strength and chemical robustness. In recent years, the CNT membrane field has progressed enormously with applications in water desalination. The latest theoretical and experimental developments on the desalination of CNT membranes, including vertically aligned CNT (VACNT) membranes, composited CNT membranes, and their applications are timely and comprehensively reviewed in this manuscript. The mechanisms and effects of CNT membranes used in water desalination where they offer the advantages are also examined. Finally, a summary and outlook are further put forward on the scientific opportunities and major technological challenges in this field

Granulosa tumor: two spontaneous pregnancies after combined medico-surgical treatment: case report and review of the literature

Abstract Background Granulosa tumor is a rare tumor that arises from the mesenchyme and the sexual cord of the ovary. The prognosis is generally excellent, and treatment is mainly based on surgery, followed by chemotherapy depending on the extension of the disease. However, “the obstetrical prognosis” is compromised. Case presentation We report the case of a 32-year-old Caucasian patient who was diagnosed during a primary infertility assessment with an ultrasound image of a 39 mm organic left ovarian cyst confirmed on pelvic magnetic resonance imaging with infiltration of the uterosacral space. Tumor markers, including cancer antigen 125, alpha fetoprotein, and β-human chorionic gonadotropin, were normal. Histological study of biopsies of the ovarian lesion taken during exploratory laparoscopy confirmed the diagnosis of adult granulosa tumor. After a normal extension assessment including a thoracoabdominopelvic computed tomography scan and a positron emission tomography scan, the patient underwent complete conservative surgery and the disease was classified as stage Ic. Three cycles of adjuvant chemotherapy according to the “BEP” protocol combining bleomycin, etoposide, and cisplatin were performed after oocyte cryopreservation. After a 5-year follow-up period, the patient had no sign of tumor progression and had two spontaneous pregnancies, the first occurring 3 months after the end of chemotherapy and the second 14 months later. Conclusion Granulosa cell tumor remains a rare tumor whose management considerably compromises fertility and reduces the chances of having a spontaneous pregnancy. The particularity of our observation is that the diagnosis of the granulosa tumor was made following a primary infertility assessment and that the patient had two spontaneous pregnancies 3 months after the end of a medico-surgical treatment known to be very gonadotoxic

Influence of Cyclodextrins on Thermosensitive and Fluorescent Properties of Pyrenyl-Containing PDMAA

A series of pyrenyl-containing PDMAA copolymers were prepared by free radical copolymerization of dimethylacrylamide (DMAA) with pyrenebutanoyloxy ethyl methacrylate (PyBEMA). The structure of as-prepared copolymers was characterized by UV, FT-IR and 1H NMR spectroscopy. The effect of cyclodextrins (α-CD, β-CD and γ-CD) on the thermosensitivity and fluorescence of the copolymers in aqueous solutions were investigated. It was found that the as-prepared copolymers exhibit lower critical solution temperature (LCST)-type thermosensitivity. Cloud point (Tcp) decreases with the increasing molar content of PyBEMA unit in the copolymers. Tcp of the copolymers increases after the CD is added from half molar to equivalent amount relative to pyrenyl moiety, and that further adding twice equivalent CD results in a slight decrease in Tcp. The copolymers exhibit a pyrene emission located at 377 nm and a broad excimer emission centered at 470 nm. The copolymers in water present a stronger excimer emission (Intensity IE) relative to monomer emission (Intensity IM) than that in ethanol. The IE/IM values decrease after the addition of equivalent α-CD, β-CD and γ-CD into the copolymers in aqueous solution, respectively. The IE/IM values abruptly increase as the copolymers’ concentration is over 0.2 mg/L whether in ethanol solution or aqueous solution with or without CD, from which can probably be inferred that intra-polymeric pyrene aggregates dominate for solution concentration below 0.2 mg/L and inter-polymeric pyrene aggregates dominate over 0.2 mg/L. Furthermore, the formation of the CD pseudopolyrotaxanes makes it possible to form pyrene aggregates. For high concentration of 5 g/L, the copolymers and their inclusion complexes completely exhibit an excimer emission. The IE values abruptly increased as the temperature went up to Tcp, which indicates that the IE values can be used to research phase separation of polymers