Development of a Radio Telescope for Very Low Frequency Observations

Sudden ionospheric disturbances are transient changes in the ionosphere caused by enhancement in X-ray and EUV fluxes during solar flare events. The Solar Storm Radio Telescope is developed to detect Very Low Frequency (VLF) signals with frequency between 3-30 kHz transmitted from various VLF stations around the Globe. We will also be investigating different methods to reduce the background noise in the data collection. This will help to ensure an accurate hit when there is a sudden ionospheric disturbance

Development of a Radio Telescope for Very Low Frequency Observations

Sudden ionospheric disturbances are transient changes in the ionosphere caused by enhancement in X-ray and EUV fluxes during solar flare events. The Solar Storm Radio Telescope is developed to detect Very Low Frequency (VLF) signals with frequency between 3-30 kHz transmitted from various VLF stations around the Globe. We will also be investigating different methods to reduce the background noise in the data collection. This will help to ensure an accurate hit when there is a sudden ionospheric disturbance

Research on Casing Deformation Prevention Technology of a Deep Shale Gas Well Based on Cementing Slurry System Optimization

In the complex fracturing process of shale gas wells, casing is subjected to serious deformation, which can easily to the failure of wellbore integrity and the reduction of well construction productivity. It is particularly important to clarify the casing deformation mechanism and carry out effective control. Based on the logging data of casing deformation from well and full-scale indoor tests, the casing deformation mechanism is mainly considered to be shear and non-uniform extrusion deformation caused by formation slip and displacement control, i.e., the ultimate working conditions. The slip displacement boundary (<40 mm) under complex fracturing conditions is quantified to provide the design and optimization basis. Then, the influence laws of steel grade and wall thickness on the shear and non-uniform extrusion bearing characteristics are studied, using unconventional oil and gas well casing simulation test systems for 110 ksi (φ139.7 × 10.54 mm) and 125 ksi (φ139.7 × 12.7 mm) casings. Furthermore, combined with the full-scale simulation tests and finite-element simulation, the effects of elastic and modified cement slurry with hollow glass beads on casing deformation are compared and studied. The results show that the deformation capacity mitigation of casing is limited by reducing the cement elastic modulus and increasing the elastic cement thickness. By reasonably adding hollow glass beads of modified cement slurry, the maximum geological movement absorption of cement slurry is up to 27 mm. This new method can obviously decrease casing deformation and have an excellent control effect. Combined with the cementing technology of Luzhou blocks, the formula of modified cement slurry is optimized, and the optimization window of the casing deformation control process is formed, which can ensure the smooth progress of engineering fracturing

Carbon nanoparticle-assisted natural orifice specimen extraction surgery with left colic artery preservation: a retrospective study

INTRODUCTION: Natural orifice specimen extraction surgery (NOSES) has been widely regarded as a new technology in minimally invasive surgery. Meanwhile, carbon nanoparticles have been increasingly used for lymph node tracing in colorectal cancer surgery. AIM: To evaluate the effectiveness and feasibility of carbon nanoparticle-assisted natural orifice specimen extraction surgery with left colic artery preservation for total laparoscopic colorectal resection. MATERIAL AND METHODS: We retrospectively reviewed the medical records of 83 patients diagnosed with sigmoid colon cancer or mid- and upper-rectal cancer from October 2017 to June 2020. These patients were divided into the NOSES group who underwent left colic artery preservation NOSES, being injected with a carbon nanoparticle suspension under colonoscopy the day before surgery, and the LA group, who underwent left colic artery preservation laparoscopic surgery. Surgical outcomes were retrospectively analyzed. RESULTS: The mean number of harvested lymph nodes (p < 0.001) in the NOSES group was higher than in the LA group. Conversely, as regards pain score (p < 0.001) and postoperative hospital stay (p = 0.035), the LA group has higher mean values. The incidence of perioperative complications (p = 0.385) was 5.3% for the NOSES group compared to 13.3% for the LA group. CONCLUSIONS: Preoperative colonoscopic injection of a carbon nanoparticle suspension is a feasible and practical solution to dissect lymph nodes surrounding the inferior mesenteric artery without affecting the left colic artery in patients with colorectal cancer and about to receive NOSES. Moreover, NOSES combined with this approach leads to less postoperative pain and shorter hospital stays

<b>Pathogen-Specific Alterations in Intestinal Microbiota Precede Urinary Tract Infections in Preterm Infants: A Longitudinal Case-Control Study</b>

Supplementary profiles of manuscript entitled "Pathogen-Specific Alterations in Intestinal Microbiota Precede Urinary Tract Infections in Preterm Infants: A Longitudinal Case-Control Study"</p

Fabrication and characteristics of Cu@Ag composite solder preform by electromagnetic compaction for power electronics

Cu@Ag core-shell particles not only have advantages of Cu and Ag elements but also inhibit Ag migration and Cu oxidation issues. These particles can be potential die attach materials for power electronics. However, micro/nano particles sintering normally form residuals and voids due to binder. Electromagnetic compaction (EMC) can fabricate Cu@Ag solder preforms with low porosity and high internal stress, which can be a trigger to successfully decrease the bonding temperature and pressure during die attach process in previous work. In this work, Cu@Ag solder preform was fabricated by electroless plating and EMC. Effects of EMC parameters on microstructure, property and formation mechanism of Cu@Ag powders were systematically investigated. As the input voltage increased from 2800V to 4400V, the compaction pressure rose to nearly 2700N. The compactness and density of Cu@Ag solder preform increased linearly, while their roughness and resistivity dropped significantly. Besides, thermal stability, oxidation resistance and 2 corrosion resistance of Cu@Ag solder preforms also increased with higher compactness