Controlling surface plasmon polaritons in transformed coordinates

Transformational optics allows for a markedly enhanced control of the electromagnetic wave trajectories within metamaterials, with interesting applications ranging from perfect lenses to invisibility cloaks, carpets, concentrators and rotators. Here we present a review of curved anisotropic heterogeneous meta-surfaces designed using the tool of transformational plasmonics, in order to achieve a similar control for surface plasmon polaritons in cylindrical and conical carpets (for the latter we provide some analytical insight), as well as cylindrical cloaks, concentrators and rotators of a non-convex cross-section. Finally, we provide an asymptotic form of the geometric potential for surface plasmon polaritons on such surfaces in the limit of a small curvature.     

Safety assessment of the conversion of toll plazas to all-electronic toll collection system

Traditional mainline toll plaza (TMTP) is considered the most high-risk location on the toll roads. Conversion from TMTP or hybrid mainline toll plaza (HMTP) to an all-electronic toll collection (AETC) system has demonstrated measured improvement in traffic operations and environmental issues. However, there is a lack of research that quantifies the safety impacts of these new tolling systems. This study evaluated the safety effectiveness of the conversion from TMTP or HMTP to AETC system. An extensive data collection was conducted that included hundred mainline toll plazas located on more than 750 miles of toll roads in Florida. Various observational before-after studies including the empirical Bayes method were applied.     

Novel Amperometric Xanthine Biosensors Based on REGO-NP (Pt,Pd, and Au) Bionanocomposite Film

Amperometric biosensor was fabricated using nanocomposite film which is constructed by separate embedding of reduced expanded graphene oxide (REGO), REGO-gold, REGO-palladium, and REGO-platinum into poly(glycidyl methacrylate-co-vinylferrocene) (P(Vfc_0.4-GMA)), and by covalent immobilization of xanthine oxidase (XOD) on the surface of nanocomposite-coated electrode. Using these tailored nanocomposites and surface binding of XOD, it has been systematically studied to obtain optimum and most ideal system for xanthine detection in real samples. The best performance in xanthine detection was REGO-platinum-based nanocomposite electrode which is able to detect xanthine with sensitivity of 21.98 μA/μM it has linear range of 1 to 40 μM, low detection limit of 0.003 μM, and excellent response time of 2 s. At the end, fabricated electrode was subjected to real sample testing by measuring xanthine concentration in chicken and meat. Biosensor was found to be very reliable and with minimum interference applicable in meat freshness control as well.     

New Twists of 3D Chiral Metamaterials

Rationally designed artificial materials, called metamaterials, allow for tailoring effective material properties beyond (“meta”) the properties of their bulk ingredient materials. This statement is especially true for chiral metamaterials, as unlocking certain degrees of freedom necessarily requires broken centrosymmetry. While the field of chiral electromagnetic/optical metamaterials has become rather mature, the field of elastic/mechanical metamaterials is just emerging and wide open. This research news reviews recent theoretical and experimental progress concerning 3D chiral mechanical and optical metamaterials, with special emphasis on work performed at KIT.     

Hybrid soft computing approach for determining water quality indicator: Euphrates River

Neural Computing and Applications - Recent approaches toward solving the regression problems which are characterized by dynamic and nonlinear pattern such as machine learning modeling (including...     

Parrot Beak-Inspired Metamaterials with Friction and Interlocking Mechanisms 3D/4D Printed in Micro and Macro Scales for Supreme Energy Absorption/Dissipation

Energy absorption and dissipation features of mechanical metamaterials have widespread applications in everyday life, ranging from absorbing shock impacts to mechanical vibrations. This article proposes novel bioinspired friction-based mechanical metamaterials with a zero Poisson's ratio behavior inspired from parrot's beaks and manufactured additively. The mechanical performances of the corresponding metamaterials are studied at both macro and micro scales by experiments and finite element analysis (FEA). An excellent agreement is observed between the FEA and both microscopic and macroscopic scale experiments, showing the accuracy of the developed digital tool. Performances are compared to traditional triangular lattice metamaterials. Both experimental tests and FEA results demonstrate the following advantages: 1) absorbing and dissipating energy per unit of mass (SEA) at large compressive strains without global buckling; 2) bistable deformation patterns including friction-based and interlocking mechanisms; 3) reversible deformation patterns after unloading; 4) shape recovery behavior after a heating–cooling process; and 5) the higher elastic modulus of micro metamaterials compared with their macro counterparts. This is the first demonstration of a bioinspired friction-based design of 3D-printed mechanical metamaterials that feature absorbing/dissipating energy, stability, and reversibility properties to cater to a wide range of sustainable meta-cylinders in micro and macro scales.