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Alcubierre's warp-drive was the first to introduce superluminal travel from different approaches. Instead of creating a shortcut through spacetime via a wormhole, geometrodynamics of simultaneously contracting and expanding spacetime were conjectured. However, both methods require exotic matter that violates energy conditions. In this paper, we employ the concept of braneworld that naturally influences spacetime geometrodynamics. Starting from defining and developing the spacetime metric of the braneworld warp bubble, the expression for energy densities as a function of relevant parameters which contributes to the braneworld approach of superluminal travel by hyperspace-drive was derived. [ABSTRACT FROM AUTHOR]

The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) infections that were first detected in Wuhan, China, at the end of 2019 led to the state of the global COVID-19 pandemic declared by the World Health Organization in March 2020. Thus, the world faces a new challenge to control the spread of the virus. The pandemic highlighted the need for rapid detection of infections that would be able to accurately screen the population much more rapidly and economically than the gold standard molecular biology-based tools such as quantitative real-time reverse transcription polymerase chain reaction. Such screening measures would be able to isolate infected individuals, including those showing no symptoms, and provide early treatments before more serious complications develop, thus allowing for the spread of infections to be better controlled without the implementation of socioeconomically crippling lockdowns. In this review, we present a comprehensive overview of the major advances in the use of electrolyte-gated field effect transistor-based biosensors for the detection of viruses, including their use for SARS-CoV-2 detection. We describe the main types of bioreceptors used for the detection of viruses in general and those used for COVID-19 in detail. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to investigate the effect of physical vapor deposition (PVD)-coated stencil wall aperture on the life span of fine-pitch stencil printing. Design/methodology/approach: The fine-pitch stencil used in this work is fabricated by electroform process and subsequently nano-coated using the PVD process. Stencil printing process was then performed to print the solder paste onto the printed circuit board (PCB) pad. The solder paste release was observed by solder paste inspection (SPI) and analyzed qualitatively and quantitatively. The printing cycle of up to 80,000 cycles was used to investigate the life span of stencil printing. Findings: The finding shows that the performance of stencil printing in terms of solder printing quality is highly dependent on the surface roughness of the stencil aperture. PVD-coated stencil aperture can prolong the life span of stencil printing with an acceptable performance rate of about 60%. Originality/value: Stencil printing is one of the important processes in surface mount technology to apply solder paste on the PCB. The stencil's life span greatly depends on the type of solder paste, stencil printing cycles involved and stencil conditions such as the shape of the aperture, size and thickness of the stencil. This study will provide valuable insight into the relationship between the coated stencil wall aperture via PVD process on the life span of fine-pitch stencil printing. [ABSTRACT FROM AUTHOR]