Gas Sensing Ionic Liquids on Quartz Crystal Microbalance

Recent advances in “designer solvents” have facilitated the development of ultrasensitive gas sensing ionic liquids (SILs) based on quartz crystal microbalance (QCM) that can real‐time detect and discriminate volatile molecules. The amalgamation of tailored‐made SILs and label‐free QCM resulted in a new class of qualitative and semi‐quantitative gas sensing device, which represents a model system of electronic nose. Because a myriad of human‐made or naturally occurring volatile organic compounds (VOCs) are of great interest in many areas, several functional SILs have been designed to detect gaseous aldehyde, ketone, amine and azide molecules chemoselectively in our laboratory. The versatility of this platform lies in the selective capture of volatile compounds by thin‐coated reactive SILs on QCM at room temperature. Notably, the detection limit of the prototype system can be as low as single‐digit parts‐per‐billion. This chapter briefly introduces some conventional gas sensing approaches and collates recent research results in the integration of SILs and QCM and finally gives an account of the state‐of‐the‐art gas sensing technology

Scalar Gravitational Waves Can Be Generated Even Without Direct Coupling Between Dark Energy and Ordinary Matter

We point out, the scalar sector of gravitational perturbations may be excited by an isolated astrophysical system immersed in a universe whose accelerated expansion is not due to the cosmological constant, but due to extra field degrees of freedom. This is true even if the source of gravitational radiation did not couple directly to these additional fields. We illustrate this by considering a universe driven by a single canonical scalar field. By working within the gauge-invariant formalism, we solve for the electric components of the linearised Weyl tensor to demonstrate that both the gravitational massless spin-2 (transverse-traceless) tensor and the (Bardeen) scalar modes are generated by a generic astrophysical source. For concreteness, the Dark Energy scalar field is either released from rest, or allowed to asymptote to the minimum in a certain class of potentials; and we compute the traceless tidal forces induced by gravitational radiation from a hypothetical compact binary system residing in such a universe. Though their magnitudes are very small compared to the tensors', spin zero gravitational waves in such a canonical scalar driven universe are directly sensitive to both the Dark Energy equation of state and the eccentricity of the binary's orbit.Comment: 28 pages, 2 figure

A Flow-based Method to Measure Traffic Statistics in Software Defined Network

Since software defined network became a revolution of network, many new developments and deployments are put forward. Device operating in software defined network environment will need a controller to store control policy. As a result of flow is one of traffic presentation units in software defined network, hence, this paper proposed a prototype of flow-based method to measure traffic statistics which can be used in OpenFlow network. By analysis of flow table, active flows which managed by controller can be listed, and information of each flow can be presented with developed module on the controller. After gathered port statistics from OpenFlow switch and entries in flow table, information of each flow can be presented on a developed graphic interface. By using this method, Traffic statistics of each flow may be more adaptive and realizable for measurement for observation