Combination of double and single cyclic pressure alternation technique to increase CO2 sequestration with heat mining in enhanced geothermal reservoirs by thermo-hydro-mechanical coupling method

The rise in global temperature due to an unceasingly increase in non-condensable gases (NCG) prompts more development of safe and economical CCUS (Carbon Capture Utilization and Storage) technologies. Carbon dioxide (CO₂) sequestration with heat mining in deep enhanced geothermal systems (EGSs) is one of the promising methods to reduce CO₂ emitted to the atmosphere. In this study, a cyclic alternation of pressures at the injection and production wells is applied in an EGS for heat mining together with CO₂ deposit. Simultaneous alternation of the injection and production pressures can significantly increase the amount of CO₂ sequestrated compared to applying a fixed pumping or withdrawing pressures at the injector and producer respectively. At the injection well, alternation in pumping pressures at high frequency (small interval of days) increased CO₂ sequestration rate. Reducing the pumping frequency resulted in the lowering of the total amount of CO₂ sequestrated, lesser than using a fixed pumping pressure. The alternation in pumping frequency has a direct relationship to the CO₂ sequestration rate. The frequency of the injection and production pressures refers to the interval in days of the interchange in pressure between high to a low value and vice-versa. Furthermore, simultaneous alternation of pressures at the injection and production wells respectively (double cyclic method) improved geothermal heat extraction efficiency, thus higher performance for both geothermal and CO₂ sequestration projects.     

Addressing amorphization and transgranular fracture of B4C through Si doping and TiB2 microparticle reinforcing

Over the last two decades, many studies have contributed to improving our understanding of the brittle failure mechanisms of boron carbide and provided a road map for inhibiting the underlying mechanisms and improving the mechanical response of boron carbide. This paper provides a review of the design and processing approaches utilized to address the amorphization and transgranular fracture of boron carbide, which are mainly based on what we have found through 9 years of work in the field of boron carbides as armor ceramics.     

In Situ Disinfection through Photoinspired Radical Oxygen Species Storage and Thermal‐Triggered Release from Black Phosphorous with Strengthened Chemical Stability

Photodynamic therapy (PDT) utilizing light‐induced reactive oxygen species (ROS) is a promising alternative to combat antibiotic‐resistant bacteria and biofilm. However, the photosensitizer (PS)‐modified surface only exhibits antibacterial properties in the presence of light. It is known that extended photoirradiation may lead to phototoxicity and tissue hypoxia, which greatly limits PDT efficiency, while ambient pathogens also have the opportunity to attach to biorelevant surfaces in medical facilities without light. Here, an antimicrobial film composed of black phosphorus nanosheets (BPSs) and poly (4‐pyridonemethylstyrene) endoperoxide (PPMS‐EPO) to control the storage and release of ROS reversibly is introduced. BPS, as a biocompatible PS, can produce high singlet oxygen under the irradiation of visible light of 660 nm, which can be stably stored in PPMS‐EPO. The ROS can be gradually thermally released in the dark. In vitro antibacterial studies demonstrate that the PPMS‐EPO/BPS film exhibits a rapid disinfection ability with antibacterial rate of 99.3% against Escherichia coli and 99.2% against Staphylococcus aureus after 10 min of irradiation. Even without light, the corresponding antibacterial rate reaches 76.5% and 69.7%, respectively. In addition, incorporating PPMS significantly improves the chemical stability of the BPS.     

Embedding ZnSe nanodots in nitrogen-doped hollow carbon architectures for superior lithium storage

Nano Research - Transition metal chalcogenides represent a class of the most promising alternative electrode materials for high-performance lithium-ion batteries (LIBs) owing to their high...     

Pulmonary actinomycosis with "balls-in-a hole" appearance diagnosed by examination of bronchial lavage fluid

A 49-year-old man was referred to our hospital because of abnormal chest X-ray findings. Chest X-ray films showed infiltrative opacities in the right lung, and histological findings of a transbronchial biopsy specimen showed non-specific inflammation. The patient was treated with Ofloxacin for one month. After the treatment, chest X-ray films showed that the infiltrative opacities in the right upper lobe had decreased, but that opacities in the right lower lobe had increased, with an air meniscus sign. A chest computed tomography scan at the same time revealed that the remaining opacities contained multiple mass-like lesions within a cavity in the right S6, appearing as "balls in a hole". One year after the first visit, the patient visited the hospital again because of cough and sputum. A chest X-ray film showed that the size of the cavity in the right lower lobe had increased. The histological findings from a fresh transbronchial biopsy specimen revealed a non-specific inflammation again; however, black clots obtained from bronchial lavage fluid after biopsy were histologically identified as sulfur granules, a classic pathological indication of actinomycosis. This confirmed the diagnosis of pulmonary actinomycosis. The patient was treated with penicillin, and the opacities in the right lower lobe subsided.     

Formation of metastable wurtzite phase boron nitride by emulsion detonation synthesis

Emulsion detonation synthesis (EDS) is a newly developed process to synthesize nano‐sized ceramic powders based on the detonation of 2 water‐in‐oil emulsions. The process provides high pressure and temperature along with rapid quenching. In this work, we report the formation of wurtzite phase BN (w‐BN) for the first time by EDS process, using hexagonal BN (h‐BN) as the precursor. Characterization studies demonstrated the formation of w‐BN with sizes varying from nanometer to micrometer scale either embedded in or grown from h‐BN matrix. These findings provide a new avenue to synthesize metastable and superhard BN phases.     

Multimedia Services for Highway Infrastructure Management

Photographic logging systems used by highway agencies provide engineers with information in the analysis of traffic accidents, design improvements, and highway pavement management. However, there exist limitations for such systems in the areas of accessibility, search capability of the image library, and synchronization video data with traditional engineering site data. More important, there are situations in which multiple users may need to examine the video footage at the same time. This capability cannot be provided by current systems. The analog nature of the video signals also presents difficulties in integrating the visual information with other types of data. This paper introduces a type of multimedia service that can be applied in a state highway department environment for highway infrastructure management. This multimedia‐based information system utilizes state‐of‐the‐art technologies in digital video, high‐speed networking, and video server. This paper discusses the requirements of high‐speed networking systems and presents a new computer network that has the potential to become a dominant technology for the transmission of multimedia data. In addition, design concerns regarding the video server and its structure are also discussed. A data‐synchronization algorithm is also presented on how to dynamically display digital video frames with traditional engineering data sets that contain information such as as‐built data, pavement condition and performance, traffic safety, geometric features, and other infrastructure data.     

Nanocarrier‐Mediated Codelivery of Small Molecular Drugs and siRNA to Enhance Chondrogenic Differentiation and Suppress Hypertrophy of Human Mesenchymal Stem Cells

Cartilage loss is a leading cause of disability among adults, and effective therapy remains elusive. Human mesenchymal stem cells (hMSCs), which have demonstrated self‐renewal and multipotential differentiation, are a promising cell source for cartilage repair. However, the hypertrophic differentiation of the chondrogenically induced MSCs and resulting tissue calcification hinders the clinical translation of MSCs for cartilage repair. Here, a multifunctional nanocarrier based on quantum dots (QDs) is developed to enhance chondrogenic differentiation and suppress hypertrophy of hMSCs simultaneously. Briefly, the QDs are modified with β‐cyclodextrin (β‐CD) and RGD peptide. The resulting nanocarrier is capable of carrying hydrophobic small molecules such as kartogenin in the hydrophobic pockets of conjugated β‐CD to induce chondrogenic differentiation of hMSCs. Meanwhile, via electrostatic interaction the conjugated RGD peptides bind the cargo siRNA targeting Runx2, which is a key regulator of hMSC hypertrophy. Furthermore, due to the excellent photostability of QDs, hMSCs labeled with the nanocarrier can be tracked for up to 14 d after implantation in nude mice. Overall, this work demonstrates the potential of our nanocarrier for inducing and maintaining the chondrogenic phenotype and tracking hMSCs in vivo.     

Efficient characterization for protein crystals using confocal Raman spectroscopy

Confocal Raman spectroscopy was applied to the characterization of various states emerging in the screening of protein crystallization. Four main characterized states, namely single crystals, microcrystals, precipitates, and clear drops without solid materials, appear in a droplet for crystallization; the first three states should be critically distinguished and characterized because of the limitations of visual observation under an optical microscope. Using lysozyme and other proteins, crystallization was performed by the hanging drop vapor diffusion technique and was monitored through an automated confocal Raman system. Prior to the spectroscopic analysis, an optical microscope with a charge-coupled device (CCD) camera and associated image processing software were used to rapidly identify the XY locations to be measured spectroscopically by focusing the laser beam on a test sample. Instead of the current image analysis by optical microscopy, confocal Raman spectroscopy with a high spatial resolution was used to identify the state of protein crystallization. Such real-time Raman monitoring also distinguished real protein crystals from pseudo-protein crystals emerging in a crystallization droplet.     

Improvement in heat transfer performance by employing unique screen inserts in a horizontal heat pipe under small heat flux conditions

Two kinds of screen mesh inserts were produced with unique cross-sectional shapes (NW2 and NW3) to improve heat transfer in a horizontal evaporating tube under small heat flux conditions. These inserts were expected to supply liquid from the thick bottom layer to the upper (top) part of a heated horizontal round tube, which is the most difficult part to wet. In the present work, heat transfer performances were investigated experimentally by using a horizontal heat pipe with a visual observation capability. The experimental results showed that NW2 and NW3 worked well if the heat flux was less than 8 kW/m². This improvement was confirmed by comparison with both the data for an ordinary screen-mesh wick and calculated results based on an analytical model. © 1998 Scripta Technica, Heat Trans Jpn Res, 26(8): 529–540, 1997