Full-Order Observer Design for a Class of Nonlinear Port-Hamiltonian Systems

In this paper, we present a simple method to design a full-order observer for a class of nonlinear port-Hamiltonian systems (PHSs). We provide a sufficient condition for the observer to be globally exponentially convergent. This condition exploits the natural damping of the system. The observer and its design are illustrated by means of an academic example system. Numerical simulations verify the convergence of the reconstructions towards the unknown system variables

Full-Order Observer Design for a Class of Nonlinear Port-Hamiltonian Systems

In this paper, we present a simple method to design a full-order observer for a class of nonlinear port-Hamiltonian systems (PHSs). We provide a sufficient condition for the observer to be globally exponentially convergent. This condition exploits the natural damping of the system. The observer and its design are illustrated by means of an academic example system. Numerical simulations verify the convergence of the reconstructions towards the unknown system variables

A study of imprint and etching behavior on fused silica of a new tailored resist mr-NIL213FC for soft UV-NIL

A new type of a specifically tailored resist for Soft Nanoimprint Lithography (Soft UV-NIL) namely mr-NIL213FC has been developed. It aims for a significant improvement of its etch-resistance with regard to underlying oxide substrates such as glass. This work demonstrates the first study of its imprint performance and etching behavior against fused silica wafers. First of all, the resist shows full compatibility with automated Soft UV-NIL using PDMS-based soft stamps and at ambient (oxygen containing) conditions for both step-and-repeat and full-wafer approaches. Moreover, the selectivity of the resist to the underlying fused silica substrate, in a high power and high etch rate condition, has reached to over 0.6, which is a significant step-up among most products in this context. The improved resistance of the resist facilitates direct etching processes for high resolution and high structure fidelity

Localized direct material removal and deposition by nanoscale field emission scanning probes

The manufactory of advanced micro- and nanoscale devices relies on capable patterning strategies. Focused electron beams, as for instance implemented since long in electron beam lithography and electron beam induced deposition, are in this regard key enabling tools especially at the early stages of device development and research. We show here that nanoscale field emission scanning probes can be potentially utilized as well for a prospective direct device fabrication by localized material deposition but notably, also by localized material removal. Field emission scanning probe processing was specifically realized on 10 nm chromium and 50 nm gold thin film stacks deposited on a (1 × 1) cm2 fused silica substrate. Localized material deposition and metal removal was studied in various atmospheres comprising high vacuum, nitrogen, ambient air, naphthalene and carbon-dioxide. Stable and reliable regimes were in particular obtained in a carbonaceous atmosphere. Hence, localized carbon deposits were obtained but also localized metal removal was realized. We demonstrate furthermore that the selected electron emission parameters (20 V - 80 V, 180 pA) and the overall operation environment are crucial aspects that determine the degree of material deposition and removal. Based on our findings, direct tip-based micro- to nanoscale material patterning appears possible. The applied energy regime is also enabling new insights into low energy (< 100 eV) electron interaction. However, the underlying mechanisms must be further elucidated

Highly anisotropic fluorine-based plasma etching of ultralow expansion glass

Deep etching of glass and glass ceramics is far more challenging than silicon etching. For thermally insensitive microelectromechanical and microoptical systems, zero-expansion materials such as Zerodur or ultralow expansion (ULE) glass are intriguing. In contrast to Zerodur that exhibits a complex glass network composition, ULE glass consists of only two components, namely, TiO2 and SiO2. This fact is highly beneficial for plasma etching. Herein, a deep fluorine-based etching process for ULE 7972 glass is shown for the first time that yields an etch rate of up to 425 nm min^-1 while still achieving vertical sidewall angles of 87°. The process offers a selectivity of almost 20 with respect to a nickel hard mask and is overall comparable with fused silica. The chemical surface composition is additionally investigated to elucidate the etching process and the impact of the tool configuration in comparison with previously published etching results achieved in Zerodur. Therefore, deep and narrow trenches can be etched in ULE glass with high anisotropy, which supports a prospective implementation of ULE glass microstructures, for instance, in metrology and miniaturized precision applications

The small noncoding RNAs (sncRNAs) of murine gammaherpesvirus 68 (MHV-68) are involved in regulating the latent-to-lytic switch in vivo

The human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi&#39;s sarcoma-associated herpesvirus (KSHV), which are associated with a variety of diseases including tumors, produce various small noncoding RNAs (sncRNAs) such as microRNAs (miRNAs). Like all herpesviruses, they show two stages in their life cycle: lytic replication and latency. During latency, hardly any viral proteins are expressed to avoid recognition by the immune system. Thus, sncRNAs might be exploited since they are less likely to be recognized. Specifically, it has been proposed that sncRNAs might contribute to the maintenance of latency. This has already been shown in vitro, but the respective evidence in vivo is very limited. A natural model system to explore this question in vivo is infection of mice with murine gammaherpesvirus 68 (MHV-68). We used this model to analyze a MHV-68 mutant lacking the expression of all miRNAs. In the absence of the miRNAs, we observed a higher viral genomic load during late latency in the spleens of mice. We propose that this is due to a disturbed regulation of the latent-to-lytic switch, altering the balance between latent and lytic infection. Hence, we provide for the first time evidence that gammaherpesvirus sncRNAs contribute to the maintenance of latency in vivo