The dual throat nozzle (DTN) technique is capable to achieve higher thrust-vectoring efficiencies than other fluidic techniques, without compromising thrust efficiency significantly during vectoring operation. The excellent performance of the DTN is mainly due to the concaved cavity. In this paper, two DTNs of different scales have been investigated by unsteady numerical simulations to compare the parameter variations and study the effects of cavity during the vector starting process. The results remind us that during the vector starting process, dynamic loads may be generated, which is a potentially challenging problem for the aircraft trim and control.
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http://dx.doi.org/10.1115/1.4025243 | DOI Listing |
J Orthop Trauma
December 2024
Section of Acute Care Surgery, Department of General Surgery, Stanford University, Stanford, CA.
Thoracic injuries are common, occurring in up to 60% of polytrauma patients and represent 25% of trauma deaths. Thoracic trauma frequently involves injury to the pleural space resulting in hemothorax and pneumothorax-effective management of the pleural space is essential. Reviewed in this article is management of the pleural space in chest wall trauma (including pneumothorax and hemothorax), and chest tube placement, indications for video-assisted thoracoscopic surgery, management, and complications.
View Article and Find Full Text PDFJ Dent Sci
December 2024
Faculty of Dentistry, The University of Hong Kong, Hong Kong, S.A.R., China.
The World Health Organization (WHO) has added glass ionomer cement (GIC) to the WHO Model List of Essential Medicines since 2021, which represents the most efficacious, safe and cost-effective medicines for priority conditions. With the potential increase in the use of GIC, this review aims to provide an overview of the clinical application of GIC with updated evidence in restorative and preventive dentistry. GIC is a versatile dental material that has a wide range of clinical applications, particularly in restorative and preventive dentistry.
View Article and Find Full Text PDFNanoscale
January 2025
Department of Chemistry, Faculty of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
We report photodissociation processes and spectral measurements upon photoabsorption of size-selected cationic silver clusters, Ag, stored in an ion trap. The experiment shows that small clusters ( ≲ 15) dissociate upon one-photon absorption, whereas larger ones require multiple photons up to five in the present study. The emergence of multi-photon processes is attributed to collisional cooling in the presence of a buffer helium gas in the trap, which competes with size-dependent dissociation rates.
View Article and Find Full Text PDFChemphyschem
January 2025
Changchun University of Technology, No. 3000, Beiyuanda Street, Gaoxinbei District, Changchun, Jilin, China, CHINA.
With the rapid advancement of information technology, the need to achieve ultra-high-density data storage has become a pressing necessity. This study synthesized three hyperbranched polyimides (HBPI-TAPP, HBPI-(Zn)TAPP, and HBPI-(Cu)TAPP) by polymerizing 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAPP), which features a cavity for metal ion coordination, with 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), to systematically investigate the effect of metal ion species on storage performance. According to the results, memory devices based on HBPI-(Zn)TAPP exhibit volatile SRAM (static random-access memory) characteristics, whereas devices employing HBPI-TAPP and HBPI-(Cu)TAPP demonstrate non-volatile WORM (write-once, read-many) characteristics.
View Article and Find Full Text PDFSmall
January 2025
National Engineering Lab for Textile Fiber Materials & Processing Technology, Zhejiang Sci-Tech University, Hangzhou, 310018, P. R. China.
2D materials feature large specific surface areas and abundant active sites, showing great potential in energy storage and conversion. However, the dense, stacked structure severely restricts its practical application. Inspired by the structure of bamboo in nature, hollow interior and porous exterior wall, hollow MXene aerogel fiber (HA-TiCT fiber) is proposed.
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