Molecularly Capped Omniphobic Polydimethylsiloxane Brushes with Ultra-Fast Contact Line Dynamics

Droplet friction is common and significant in any field where liquids interact with solid surfaces. This study explores the molecular capping of surface-tethered, liquid-like polydimethylsiloxane (PDMS) brushes and its substantial effect on droplet friction and liquid repellency. By exchanging polymer chain terminal silanol groups for methyls using a single-step vapor phase reaction, the contact line relaxation time is decreased by three orders of magnitude–from seconds to milliseconds. This leads to a substantial reduction in the static and kinetic friction of both high- and low-surface tension fluids. Vertical droplet oscillatory imaging confirms the ultra-fast contact line dynamics of capped PDMS brushes, which is corroborated by live contact angle monitoring during fluid flow. This study proposes that truly omniphobic surfaces should not only have very small contact angle hysteresis, but their contact line relaxation time should be significantly shorter than the timescale of their useful application, i.e., a Deborah number less than unity. Capped PDMS brushes that meet these criteria demonstrate complete suppression of the coffee ring effect, excellent anti-fouling behavior, directional droplet transport, increased water harvesting performance, and transparency retention following the evaporation of non-Newtonian fluids.     

Development of asphalt cements for road pavement using sustainable nanomaterials: A review

In today's world, transportation infrastructure plays a vital role in global competitiveness and quality of life in societies. The pavement industry deals with tremendous amounts of construction materials. Thus, even a small improvement in the technology can lead to significant environmental benefits and a reduction in the life-cycle cost of road networks. Asphalt cement is an integral part of road pavement construction, and despite favorable properties at the processing temperature, some challenges need to be addressed to reduce cost and improve performance. This review discusses the nanocellulose modification of asphalt cement for pavement application. Three primary cellulose-based nanoparticles were studied, including bacterial cellulose, cellulose nanofibers, and cellulose nanocrystals, and their applications in asphalt cement modification. Various research results show significant improvement in pavement's rheological and performance properties with the help of cellulose-based nanoparticles. However, this review provides the reader with an objective evaluation of the benefits and practical challenges ahead of the industrial-scale application of nanocellulose in the pavement industry.     

Body landmark detection with an extremely small dataset using transfer learning

Pattern Analysis and Applications - We present a new landmark detection problem on the upper body of a clothed person for tailoring purposes. This is a landmark detection problem unknown in the...     

Investigation of mixing performance in a semi-active T-micromixer actuated by magnetic nanoparticles: Characterization via Villermaux–Dushman reaction

A semi-active T-type micromixer is designed to intensify micromixing by actuating magnetic nanoparticles (MNPs). Five permanent magnets in a zig-zag arrangement are located next to the mixing channel of the micromixer to apply the magnetic field to the fluid flow. Micromixing performance is considered in terms of the segregation index (X_S) by the Villermaux/Dushman reaction test. The effects of magnetic flux intensity (B = 380–500 mT), the concentration of MNPs (φ = 0.002–0.01 [w/v]), and flow rate ratios on X_S and pressure drop are investigated. By increasing MNPs concentration from φ = 0.002–0.008 (w/v), X_S decreased and the rise in φ up to 0.008 (w/v) has not been significant on X_S. Maximum mixing efficiency (i.e., minimum X_S = 0.0088) is achieved for B = 500 mT and φ = 0.01 (w/v). By applying the magnetic field, the mixing performance increased due to the motion of MNPs, but its negative effect is an increase in the pressure drop along the micromixer reactor. Generally, with the formation of MNPs barriers inside the mixing channel, the main fluid flows through these layers and creates the sinusoidal flow paths compared to no magnetic field conditions, and thus, a superior mixing efficiency could be attained.     

Application of smart packaging for seafood: A comprehensive review

Nowadays, due to the changes in lifestyle and great interest of consumers in a healthy life, people have started increasing their seafood consumption. But due to their short shelf life, experts are looking for a new packaging called smart packaging (SMP) for seafood. There are different indicators/sensors in SMP; one of the effective indices is time–temperature, which can show consumers the best time of using seafood based on their shelf life and experienced temperature. Another one is radio-frequency identification (RFID) that is a transmission device that represents a separate form of the electronic information-based SMP systems. RFID does not belong to any of the categories of markers or sensors; it is an auto recognition system that applies cordless sensors to indicate segments and collect real-time information without manual interposition. This review covers the use of SMP in all marine foods, including fish, due to its high consumption and high content of polyunsaturated fatty acids, eicosapentaenoic acid (C20:5n-3) and docosahexaenoic acid (C22:6n-3), which are the considerable factors of n-3 polyunsaturated fatty acids for human.     

Biomimetic Polycaprolactone-Graphene Oxide Composites for 3D Printing Bone Scaffolds

Bone shows a radial gradient architecture with the exterior densified cortical bone and the interior porous cancellous bone. However, previous studies presented uniform designs for bone scaffolds that do not mimic natural bone's gradient structure. Hence, mimicking native bone structures is still challenging in bone tissue engineering. In this study, a novel biomimetic bone scaffold with Haversian channels is designed, which approximates mimicking the native bone structure. Also, the influence of adding graphene oxide (GO) to polycaprolactone (PCL)-based scaffolds are investigated by preparing PCL/GO composite ink containing 0.25% and 0.75% GO and then 3D printing scaffolds by an extrusion-based machine. Scanning electron microscopy (SEM) is used for morphological analysis. SEM reveals good printability and interconnected pore structure. The contact angle test shows that wettability reinforces with the increase of GO content. The mechanical behavior of the scaffolds under compression is examined numerically and experimentally. The results indicate that incorporation of GO can affect bone scaffolds' Young's modulus and von Mises stress distribution. Moreover, the biodegradation rates accelerate in the PCL/GO scaffolds. Biological characterizations, such as cell growth, viability, and attachment, are performed utilizing osteoblast cells. Compared to pure PCL, an enhancement is observed in cell viability in the PCL/GO scaffolds.