Method for Removing CO\u3csub\u3e2\u3c/sub\u3e from Coal-Fired Power Plant Flue Gas Using Ammonia as the Scrubbing Solution, with a Chemical Additive for Reducing NH\u3csub\u3e3\u3c/sub\u3e Losses, Coupled with a Membrane for Concentrating the CO\u3csub\u3e2\u3c/sub\u3e Stream to the Gas Stripper

A method for removing and capturing carbon dioxide from a fluid stream includes the steps of exposing the fluid stream to an aqueous scrubbing solution that removes and holds carbon dioxide from the fluid stream, passing the aqueous scrubbing solution through a membrane in order to separate excess water from the scrubbing solution and increase the concentration of carbon dioxide in the scrubbing solution, heating the scrubbing solution having an increased concentration of carbon dioxide so as to release carbon dioxide gas and recycling the scrubbing solution. A carbon dioxide capture apparatus includes a carbon dioxide scrubber, a membrane downstream from the scrubber for separating water and concentrating carbon dioxide in a scrubbing solution and a stripper vessel

Zeolite Y adsorbents with high vapor uptake capacity and robust cycling stability for potential applications in advanced adsorption heat pumps

Modular and compact adsorption heat pumps (AHPs) promise an energy-efficient alternative to conventional vapor compression based heating, ventilation and air conditioning systems. A key element in the advancement of AHPs is the development of adsorbents with high uptake capacity, fast intracrystalline diffusivity and durable hydrothermal stability. Herein, the ion exchange of NaY zeolites with ingoing Mg[superscript 2+] ions is systematically studied to maximize the ion exchange degree (IED) for improved sorption performance. It is found that beyond an ion exchange threshold of 64.1%, deeper ion exchange does not benefit water uptake capacity or characteristic adsorption energy, but does enhance the vapor diffusivity. In addition to using water as an adsorbate, the uptake properties of Mg, Na-Y zeolites were investigated using 20 wt.% MeOH aqueous solution as a novel anti-freeze adsorbate, revealing that the MeOH additive has an insignificant influence on the overall sorption performance. We also demonstrated that the lab-scale synthetic scalability is robust, and that the tailored zeolites scarcely suffer from hydrothermal stability even after successive 108-fold adsorption/desorption cycles. The samples were analyzed using N[superscript 2] sorption, [superscript 27]Al/[superscript 29]Si MAS NMR spectroscopy, ICP-AES, dynamic vapor sorption, SEM, Fick’s 2nd law and D–R equation regressions. Among these, close examination of sorption isotherms for H[subscript 2]O and N[subscript 2] adsorbates allows us to decouple and extract some insightful information underlying the complex water uptake phenomena. This work shows the promising performance of our modified zeolites that can be integrated into various AHP designs for buildings, electronics, and transportation applications.United States. Advanced Research Projects Agency-Energy (0471-1627)National Institute for Biomedical Imaging and Bioengineering (U.S.) (Awards EB-001960 and EB-002026)Natural Sciences and Engineering Research Council of Canada (Postgraduate Fellowship

Mesostructure and strength characteristics of granite under freeze-thaw cycles based on CT scanning

Objective  With the rapid increase in construction projects in the western regions in recent years, the impact of seasonal freeze-thaw cycles in the high-altitude areas of western China has become more pronounced. Conducting research on the microscopic characteristics and strength degradation properties of rocks under freeze-thaw cycles is crucial for guiding engineering construction in these cold, high-altitude regions.   Methods  To study the influence of freeze-thaw cycles on rock structure and mechanical properties, we collected diorite samples from a tunnel in the Kangding area and examined the effects of freeze-thaw cycles on their microstructure and mechanical characteristics. Firstly, thin rock sections were observed under a polarizing microscope to obtain mineral compositions and microstructures. Then, CT scanning technology was used to scan the granite samples after freeze-thaw cycles, and the scanned layers were binarized using threshold segmentation. The scanning images of different layers were binarized using threshold segmentation, and high-resolution 3D data and images of the internal and external structures of the samples were obtained by stacking the binary image layers. Fractal theory was applied to calculate the box-counting dimension of the images and quantitatively assess their complexity. This analysis allowed us to examine the evolution and distribution characteristics of the internal structure of granite under freeze-thaw cycles.  Results  Under a polarizing microscope, the rock exhibits a block-like structure with a patchy, coarse-grained, and unequal-grained granite texture, with locally visible metasomatic worm structures. The main phenocryst minerals are alkaline feldspar. Other minerals range in size from 0.25 to 4.0 mm and primarily include quartz, plagioclase, and alkaline feldspar. Secondary minerals include biotite and epidote, while accessory minerals comprise apatite, zircon, and pyrite. Microscopically, the rock is identified as porphyritic, coarse-grained, and unequal-grained biotite diorite granite. Freeze-thaw cycles were applied to the granite samples in the laboratory to study the strength evolution and explore the relationship between structural evolution and strength. The results indicate that the freeze-thaw cycle effect leads to an overall increase in the internal porosity of the granite's microstructure, though the rock's permeability changes minimally, with an increase of only 0.003×10−3 μm2. The internal pore development is uneven, primarily due to the emergence of new micropores, causing changes in the overall structure of the sample. After freeze-thaw cycles, the complexity of the internal structure of the rock decreases, but the overall integrity remains good, with the fractal dimension staying at a high level. Fractal analysis shows that 20 freeze-thaw cycles do not cause significant changes in the structural complexity of granite. However, the overall mechanical properties of the sample decline, viscosity increases, and long-term strength shows significant attenuation, raising the strain threshold for entering the creep test stage.   Conclusion  When evaluating the safety of rocks with dense primary structures, considering only their structure may lead to deviations from the actual situation. It is essential to combine necessary strength indicators for a comprehensive evaluation. After undergoing freeze-thaw cycles, rocks tend to exhibit more significant deformation while maintaining lower strength. Therefore, appropriate treatments are required for construction in high-altitude areas. [ Significance ] This study provides a reference for applying fractal theory to the evolution of rock microstructure and the relationship between rock microstructure and strength evolution. It also offers valuable guidance for engineering construction in high-altitude and cold regions

Designed Single-Step Synthesis, Structure, and Derivative Textural Properties of Well-Ordered Layered Penta-coordinate Silicon Alcoholate Complexes

The controllable synthesis of well-ordered layered materials with specific nanoarchitecture poses a grand challenge in materials chemistry. Here the solvothermal synthesis of two structurally analogous 5-coordinate organosilicate complexes through a novel transesterification mechanism is reported. Since the polycrystalline nature of the intrinsic hypervalent Si complex thwarts the endeavor in determining its structure, a novel strategy concerning the elegant addition of a small fraction of B species as an effective crystal growth mediator and a sacrificial agent is proposed to directly prepare diffraction-quality single crystals without disrupting the intrinsic elemental type. In the determined crystal structure, two monomeric primary building units (PBUs) self-assemble into a dimeric asymmetric secondary BU via strong Na+[BOND]O2− ionic bonds. The designed one-pot synthesis is straightforward, robust, and efficient, leading to a well-ordered (10ī)-parallel layered Si complex with its principal interlayers intercalated with extensive van der Waals gaps in spite of the presence of substantial Na+ counter-ions as a result of unique atomic arrangement in its structure. However, upon fast pyrolysis, followed by acid leaching, both complexes are converted into two SiO2 composites bearing BET surface areas of 163.3 and 254.7 m2 g−1 for the pyrolyzed intrinsic and B-assisted Si complexes, respectively. The transesterification methodology merely involving alcoholysis but without any hydrolysis side reaction is designed to have generalized applicability for use in synthesizing new layered metal–organic compounds with tailored PBUs and corresponding metal oxide particles with hierarchical porosity.United States. Defense Advanced Research Projects Agency (control No. 0471-1627)National Institute for Biomedical Imaging and Bioengineering (U.S.) (award No. EB-001960)National Institutes of Health (U.S.) (NIBIB award No. EB-002026)National Science Foundation (U.S.) (Grant No. CHE-0946721

Design and Optimization of High Performance Adsorption-Based Thermal Battery

Electric vehicle (EV) technology faces a substantial challenge in terms of driving range, especially when the vehicle's climate control system relies entirely on the onboard electric battery. Therefore, we are developing an advanced adsorption-based thermal battery (ATB) capable of delivering both heating and cooling for electric vehicles with minimal use of the electric battery bank. While adsorption based climate control systems offer the advantage of direct usage of primary thermal energy sources for operation, they typically have low COP values, and are often bulky and heavy. A compact and lightweight ATB is necessary to replace existing climate control systems in EVs that use electric battery for operation. In this paper, we present a detailed computational analysis of adsorption kinetics taking place within an adsorption bed that is capable of delivering large cooling and heating capacities by making use of novel adsorbents. The overall design of the adsorption bed, which is a critical element in achieving a high performance thermal battery, is also discussed. To make performance predictions, we characterized the adsorbents to obtain their thermophysical and transport properties as well as adsorption characteristics. The model consequently incorporates these measured properties to predict the performance variation as a function of time. This work provides the critical parameters affecting heating and cooling rates, and identifies avenues for further improvement in the overall performance of the thermal battery

SPRR3 Contributes to Aggressiveness of Pancreatic Cancer Cells via NF-κB Signaling Pathway

Pancreatic cancer remains a deadly solid tumor with worst survival, and a better understanding of the mechanisms of carcinogenesis of pancreatic cancer is critical to promote the survival of patients with pancreatic cancer. qPCR and western blot assay were used to determine the expression of SPRR3 in pancreatic cancer. Anchorage-independent growth ability, BrdU labeling, Transwell assay, and in vivo experiment were used to examine the functions of SPRR3 in aggressiveness of pancreatic cancer. Luciferase reporter assay, nucleoplasmic-separation technique, qPCR, and western blot assay were used to investigate the mechanism of SPRR3 regulating aggressiveness of pancreatic cancer. Our results showed that SPRR3 was significantly increased in pancreatic cancer, which resulted in poor survival for patients with pancreatic cancer. Further analysis showed that overexpression of SPRR3 contributed to anchorage-independent growth ability, growth rate, and invasion ability of pancreatic cancer cells. While, knockdown of SPRR3 showed the reverse results. Mechanistically, overexpression of SPRR3 can promote the transcription of NF-κB pathway, nuclear accumulation of p65, and mRNA levels of NF-κB pathway downstream genes. But, knockdown of SPRR3 induced the reverse results. The above findings clarified the important roles of SPRR3 in the progression of pancreatic cancer through NF-κB pathway. And targeting SPRR3 might be an effective strategy to therapy pancreatic cancer

One-pot solvothermal synthesis of a well-ordered layered sodium aluminoalcoholate complex: a useful precursor for the preparation of porous Al[subscript 2]O[subscript 3] particles

One-pot solvothermal synthesis of a robust tetranuclear sodium hexakis(glycolato)tris(methanolato)aluminate complex Na[subscript 3][Al[subscript 4](OCH[subscript 3])[subscript 3](OCH[subscript 2]CH[subscript 2]O)[subscript 6]] via a modified yet rigorous base-catalyzed transesterification mechanism is presented here. Single crystal X-ray diffraction (SCXRD) studies indicate that this unique Al complex contains three pentacoordinate Al[superscript 3+] ions, each bound to two bidentate ethylene glycolate chelators and one monodentate methanolate ligand. The remaining fourth Al[superscript 3+] ion is octahedrally coordinated to one oxygen atom from each of the six surrounding glycolate chelators, effectively stitching the three pentacoordinate Al moieties together into a novel tetranuclear Al complex. This aluminate complex is periodically self-assembled into well-ordered layers normal to the [110] axis with the intra-/inter-layer bonding involving extensive ionic bonds from the three charge-counterbalancing Na[superscript +] cations rather than the more typical hydrogen bonding interactions as a result of fewer free hydroxyl groups present in its structure. It can also serve as a valuable precursor toward the facile synthesis of high-surface-area alumina powders using a very efficient rapid pyrolysis technique.United States. Advanced Research Projects Agency-Energy (0471-1627)National Institutes of Health (U.S.) (Grant EB-001960)National Institutes of Health (U.S.) (Grant EB-002026)National Science Foundation (U.S.) (Grant CHE-0946721)Natural Sciences and Engineering Research Council of Canada (Postdoctoral Fellowship

Characterization of Adsorption Enthalpy of Novel Water-Stable Zeolites and Metal-Organic Frameworks.

Water adsorption is becoming increasingly important for many applications including thermal energy storage, desalination, and water harvesting. To develop such applications, it is essential to understand both adsorbent-adsorbate and adsorbate-adsorbate interactions, and also the energy required for adsorption/desorption processes of porous material-adsorbate systems, such as zeolites and metal-organic frameworks (MOFs). In this study, we present a technique to characterize the enthalpy of adsorption/desorption of zeolites and MOF-801 with water as an adsorbate by conducting desorption experiments with conventional differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA). With this method, the enthalpies of adsorption of previously uncharacterized adsorbents were estimated as a function of both uptake and temperature. Our characterizations indicate that the adsorption enthalpies of type I zeolites can increase to greater than twice the latent heat whereas adsorption enthalpies of MOF-801 are nearly constant for a wide range of vapor uptakes