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This paper aims to study the effect of ultrasonic aluminum (Al) bonding and lamination processes on the electrical performance of copper indium gallium (di)selenide (CIGS) thin film photovoltaic (TFPV) solar panels. Ultrasonic Al bonding on the MoSe2 layer of the CIGS TFPV solar panel was performed in three configurations: eight bonds, 16 bonds, and parallel configurations. The lamination process was performed on the Al bonds with MoSe2 layers of the CIGS TFPV solar panel. Ultrasonic bonding and lamination processes significantly affect the electrical performance of CIGS TFPV solar panels. Open circuit voltage, Voc is the least affected electrical characteristic with the application of ultrasonic bonding and lamination processes as compared to short circuit current (Isc), current density (Jsc), maximum power (Pmpp), fill factor (FF), and efficiency. 8-bonds configuration has the highest efficiency, ranging from 11.45% to 13.86% throughout unique connections of I-V measurement, compared to 16-bonds ranging from 7.99% to 10.77%, and parallel configurations, ranging from 9.14% to 11.92%. The notable variations in electrical properties with the processes used to create laminated CIGS TPFV solar panels with ultrasonic Al bonding can be explained by physical examination and lock-in infrared (IR) thermography. The ultrasonic Al bond is best suited to be used as the interconnection mean in the CIGS TFPV solar panel compared to that of conductive adhesive that has been widely applied nowadays. [ABSTRACT FROM AUTHOR]

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]

Electronic applications are now driving packaging technology that is equivalent to primary computer packages for the past 25 years. The electronic application currently shows an ascending market demand due to rapid development of smart and wireless component with mixed technologies that include digital microprocessors. In ensuring the quality of the devices, the reliability of the solder joint is very vital. Attributable to their common uses, radiation particles including gamma ray is considered as one of the primary factors that could degrade the performance of the electronic devices. Thus, in this study, both mechanical and microstructure properties of lead-free solder joints radiated with gamma were investigated. Prior to the evaluation, the solder pastes of tin–silver–copper (SnAg3Cu0.5; SAC305) was manually deposited on the printed circuit board using a stencil printing method and reflow soldering process. Subsequently, the solder was exposed to low doses of gamma radiation. The current finding showed that as the radiation dose increased, the solder sample became softer and more plastic. FESEM and EDS analysis signified that intermetallic layer in the tin (Sn) matrix was dominated by Cu6Sn5 and Ag2Sn compound. According to micromechanical investigation, both hardness and reduced modulus of the solder decreased with increasing the radiation dose that was due to microstructure change and the formation of voids. [ABSTRACT FROM AUTHOR]