background: in general, measurements of solar ultraviolet (uv) radiation are related to horizontal surfaces. while the hu­mans walking and standing outdoors expose to the natural solar uv radiation, their eyes, cheeks, extremities, trunks, or many other anatomical sites are close to vertical plane and random orient to different directions. in this study, we character­ized the diurnal variations...

To better understand the effects of low-level fluorine in graphene-based sensors, first-principles density functional theory (DFT) with van der Waals dispersion interactions has been employed to investigate the structure and impact of fluorine defects on the electrical properties of single-layer graphene films. The results show that both graphite-2 H and graphene have zero band gaps. When fluor...

Carbon nanotubes are a new allotrope of carbon which emerged from the fullerene family [1]. Carbon nanotubes have been discovered by high resolution transmission electron microscopy (HRTEM) in 1991 by Iijima [2]. A single wall carbon nanotube is constituted of one atomic plane with a graphite-like arrangement of C atoms – called a graphene sheet – which is perfectly rolled into a cylinder (Fig....

Electroanalytical parameters of different graphitic carbon-based electrode materials were compared to select the best one for the pantoprazole electroanalysis. Such parameters include sensitivity, repeatability, residual background current, and signal-tobackground current ratio of the analytical response and such electrodes include conventional carbon-based electrodes such as glassy carbon (GC)...

This work describes an on-chip integrated micro-actuator device for slack-free carbon nanotube (CNT) resonators, improving frequency tunability and Q factor and to study non-linear mode interaction. The device fabricated on SOI wafer with low thermal budget (<600 K) encompasses a restricted symmetrical out-of-plane vibration and a stiff in-plane electro-thermal actuator with a displacement of ~...

In order to engineer a band gap into graphene, covalent bond-forming reactions can be used to change the hybridization of the graphitic atoms from sp(2) to sp(3), thereby modifying the conjugation length of the delocalized carbon lattice; similar side-wall chemistry has been shown to introduce a band gap into metallic single-walled carbon nanotubes. Here we demonstrate that the application of s...

The direct electrochemical oxidation of sodium sulfide has been examined at five different carbon-based electrode substrates (glassy carbon (GC), boron-doped diamond (BDD), edge-plane pyrollytic graphite (EPPG), basal-plane pyrollytic graphite (BPPG) and carbon nanotubes (CNT)). An electrocatalytic response is observed at both the EPPG and CNT electrode compared to that of the other three subst...

A maximum of 91% recovery of interfacial shear strength (IFSS) is achieved for carbon fiber/epoxy interfaces functionalized with capsules containing reactive epoxy resin and ethyl phenyl acetate (EPA). We find a binder is necessary to improve the retention of capsules on the carbon fiber surface. Two different methods for applying the binder to the carbon fiber surface are investigated. Healing...