The substitution of traditional copper power transmission cables with lightweight copper–carbon nanotube (Cu–CNT) composite fibers is critical for reducing the weight, fuel consumption, and CO₂ emissions of automobiles and aircrafts. Such a replacement will also allow for lowering the transmission power loss in copper cables resulting in a decrease in coal and gas consumption, and ultimately diminishing the carbon footprint. In this work, we created a lightweight Cu–CNT composite fiber through a multistep scalable process, including spinning, densification, functionalization, and double-layer copper deposition. The characterization and testing of the fabricated fiber included surface morphology, electrical conductivity, mechanical strength, crystallinity, and ampacity (current density). The electrical conductivity of the resultant composite fiber was measured to be 0.5 × 10⁶ S/m with an ampacity of 0.18 × 10⁵ A/cm². The copper-coated CNT fibers were 16 times lighter and 2.7 times stronger than copper wire, as they revealed a gravimetric density of 0.4 g/cm³ and a mechanical strength of 0.68 GPa, suggesting a great potential in future applications as lightweight power transmission cables.

Previously, we reported 3D Shaped 3D Graphene (3D2G) with controlled structural pores. In this work, we introduce cold rolling as a post-processing technique to obtain compressed 3D2G referred to as C3D2G. The gravimetric density, electrical conductivity, and tensile strength of C3D2G were higher than 3D2G by 37.3, 53.4, and 24.9 times, respectively. The performed comprehensive materials characterization of C3D2G revealed the micro-motion of the graphene flakes from their random orientations into a stacked and aligned structure along with the extrusion of bulk material into the structural pores which acted as stress-relief spaces. Further, a new process was demonstrated enabling the welding of multiple pieces into one structure via cold rolling, thus showing potential for dimensional scaling up. The conducted tensile and electrical conductivity studies across the welded region revealed the presence of a mechanical bond within the joined area with a higher strength than the initial pieces involved in welding. Due to the enhanced properties of C3D2G, a unique application of this material was explored as a reusable, etch-resistant hard mask for patterning silicon wafers, and as a protective barrier against fluorine plasma environment. The etch rate measurements showed a higher etching resistance of C3D2G compared to Si and SiO2 when exposed to a fluorine plasma Reactive Ion Etching (RIE).

Healthcare workers have experienced increased occupational health risks caused by COVID-19 disease. The purpose of this project was to examine the relationships between reporting COVID-19 symptoms by employees in a healthcare institution in the United States and employees’ demographics, vaccination status, co-morbid conditions, and body mass index (BMI). This project employed a cross-sectional design. It involved the analysis of data on COVID-19 exposure and infection incidents among employees in the healthcare institution. The dataset contained more than 20,000 entries. The results indicate that being female, African American, between 20 and 30 years old, diagnosed with diabetes, diagnosed with chronic obstructive pulmonary disease (COPD), or on immunosuppressive medicines is associated with greater reporting of COVID-19 symptoms by the employees. Furthermore, BMI is associated with reporting COVID-19 symptoms; the higher the BMI, the greater the likelihood of reporting a symptomatic infection. Moreover, having COPD, being 20–30 years old, being 40–50 years old, BMI, and vaccination status were significantly associated with employees reporting symptoms while controlling for other variables associated with reporting the symptoms among the employees. These findings may be applicable to other infectious disease outbreaks or pandemics.