Background: Recent advances in enamel and dentine adhesive technology have resulted in the emergence of many new adhesive systems. Self-etching bonding systems do not require a separate etching step and the newest systems are the "all-in-one" systems which combine etching, priming and bonding into a single application. This study reports laboratory enamel microshear bond strengths of a self-etching priming and three all-in-one systems and also evaluates two different microshear bond test methods. Methods: One hundred and nineteen enamel specimens were bonded (0.8mm diameter) with either Clearfil Protect Bond (Kuraray), Xeno III (Dentsply), G Bond (GC) or One-Up Bond F (Tokuyama) using Palfique Estelite resin composite and stored in 37ºC water for seven days. The microshear bond test method used either a blade or wire to apply the shear stress. Results were analysed with one-way ANOVA and post hoc (Tukey) multiple comparison analysis. Results: Clearfil Protect Bond demonstrated higher and more consistent bond strengths than Xeno III, G Bond or One-Up Bond F. The wire method showed much greater reliability in results, with a coefficient of variation half that of the blade method. Conclusions: All-in-one adhesives seem to be less reliable than the two-step self-etching priming adhesive when bonding to enamel. Test method can significantly affect results in the microshear bond test method. Key words:Microshear bond test, all-in-one adhesives, self-etching priming adhesive, enamel, enamel bonding.Abbreviations and acronyms: ANOVA = analysis of variance; CEJ = cemento-enamel junction; DEJ = dentinoenamel junction; SEM = scanning electron micrograph.

Direct methods are often deployed to solve nonlinear model predictive control problems where the optimal control problem is first transcribed into a nonlinear program and then solved to obtain the control input. This makes the computational cost of direct methods nontrivial; however, efficiencies can be gained by utilizing adaptation methods during transcription. Goal-oriented a priori error estimation is used as an adaptation strategy. Unlike other strategies, the refinement is directly related to the cost function. Therefore, refinement only occurs where it is needed with respect to the cost function. Two examples are presented and an improvement of up to 50% in the computational time is observed with no degradation in the closed-loop performance. KEYWORDSadaptive mesh generation, direct collocation, nonlinear model predictive control 4624 Assumption 1. The following assumptions are placed on the dynamic system.

In future all-optical packet networks, optical label switching technology is expected to be a promising candidate for fast and accurate data packet transmission [1,2]. To implement such networks, a simple yet low cost optical label swapping technique should be realized at the intermediate nodes. Many research efforts have been developed, based on the promising technique of orthogonal label modulation [3] due to its simple design in optical label swapping [4]. In recent years, the nonlinear phenomenon in semiconductor optical amplifiers has been widely utilized for applications in optical label erasure [5]. Recent advances in the fabrication of reflective semiconductor optical amplifiers (RSOAs) have enabled high small-signal gain, medium saturation power, and direct data modulation to be achieved [6]. In this work, we present the first demonstration of optical label swapping using an RSOA. Specifically, we exploit the high pass filter (HPF) behavior [7] originating from self-gain modulation (SGM) of the saturated RSOA to achieve simultaneous erasure and rewriting of an amplitude-shift-keying (ASK) label. We demonstrate the feasibility of a 1.25 Gb/s amplitude-shift-keying (ASK) label erasure with new label rewrite through direct modulation of the RSOA. Fig. 1 illustrates the concept of optical label switching at an intermediate network node. Initially, a fraction of the optical packets entering the network node are tapped with the tapped signals used to perform a number of time critical functions such as packet label (in the case of label switching)/header (in the case of packet switching) recognition, generation of new label for forwarding, and generation of gating pump signal to perform timing or wavelength conversion or switching functions. The other portions of the incoming optical packet with a ASK label and a differential-phase-shiftkeying (DPSK) payload is directed to an optical buffer for time adjustment. The new label rewriting process is performed at the label erasure and rewriting module, where the old ASK label is simultaneously being erased whilst a new label is inserted on top of the payload. Shown in Fig. 2 is our proof-of-concept experiment. An optical label switched signal with a 1.25 Gb/s 2 31 -1 PRBS ASK label and a 10 Gb/s 2 31 -1 PRBS DPSK payload is generated by externally modulating a continuous light from a DFB laser diode. The extinction ratio of the label is initially set at 2 dB. In order to evaluate the performance of label swapping under different power levels, the optical label switched signal is amplified by an EDFA and is ASE filtered. The signal power is controlled by an attenuator, before launching into the RSOA via the circulator. The input signal saturates the RSOA and experiences a HPF effect under the presence of SGM. Consequently, the low frequency ASK label is suppressed, whilst the highspeed DPSK payload remains unaffected. Meanwhile, the new 1.25 Gb/s ASK label can be rewritten on top of the payload by directly-modulating the carrier density of the RSOA. As a result, simu...

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