Laser ultrasonic detection for defects of LAM components based on variable time window intensity mapping with adaptive 2σ thresholds.

Metallurgical defects in metal laser additive manufacturing (LAM) are inevitable due to complex non-equilibrium thermodynamics. A laser ultrasonic system was designed for detecting surface/near-surface defects in the layer-by-layer LAM process. An approach was proposed for ultrasonic imaging of defects based on variable time window intensity mapping with adaptive 2σ threshold denoising.

Application of chelate GLDA for remediating Cd-contaminated farmlands using Tagetes patula L.

In the present study, via a 180-day field trial, the indicators of soil total cadmium, DTPA-Cd, organic matter, and plant cadmium extraction were tested after the application of chelate tetrasodium glutamate diacetate (GLDA) to investigate the potential of GLDA combined with Tagetes patula L. to remediate cadmium-contaminated soil. To do so, five GLDA treatments (e.

A Review of Research on Mechanical Properties and Durability of Concrete Mixed with Wastewater from Ready-Mixed Concrete Plant.

The wastewater from ready-mixed concrete plants is currently being recycled as concrete mixing water. It has attracted significant attention from the construction industry and researchers since it promotes sustainable development through environmental protection, energy-saving, and emissions reduction. This article review first introduces the nature of wastewater in ready-mixed concrete plants in different regions.

Nonfragile State Estimation of Quantized Complex Networks With Switching Topologies.

This paper considers the nonfragile $H_\infty $ estimation problem for a class of complex networks with switching topologies and quantization effects. The network architecture is assumed to be dynamic and evolves with time according to a random process subject to a sojourn probability. The coupled signal is to be quantized before transmission due to power and bandwidth constraints, and the quantization errors are transformed into sector-bounded uncertainties.

Global Pinning Synchronization of Complex Networks With Sampled-Data Communications.

This paper investigates the global pinning synchronization problem for a class of complex networks with aperiodic samplings. Combined with the Writinger-based integral inequality, a new less conservative criterion is presented to guarantee the global pinning synchronization of the complex network. Furthermore, a novel condition is proposed under which the complex network is globally pinning synchronized with a given performance index.

Reachable Set Estimation for Markovian Jump Neural Networks With Time-Varying Delays.

In this paper, the reachable set estimation problem is investigated for Markovian jump neural networks (NNs) with time-varying delays and bounded peak disturbances. Our goal is to find a set as small as possible which bounds all the state trajectories of the NNs under zero initial conditions. In the framework of Lyapunov-Krasovskii theorem, a newly-found summation inequality combined with the reciprocally convex approach is used to bound the difference of the proposed Lyapunov functional.

Improving performance of channel equalization in RSOA-based WDM-PON by QR decomposition.

In reflective semiconductor optical amplifier (RSOA)-based wavelength division multiplexed passive optical network (WDM-PON), the bit rate is limited by low modulation bandwidth of RSOAs. To overcome the limitation, we apply QR decomposition in channel equalizer (QR-CE) to achieve successive interference cancellation (SIC) for discrete Fourier transform spreading orthogonal frequency division multiplexing (DFT-S OFDM) signal. Using an RSOA with a 3-dB modulation bandwidth of only ~800 MHz, we experimentally demonstrate a 15.

Large-scale WDM passive optical network based on cyclical AWG.

A large scale wavelength division multiplexed passive optical network is proposed and experimentally demonstrated. 124 bidirectional optical channels with 10-Gb/s downstream and 1.25-Gb/s upstream transmission are simultaneously distributed by a single 32*32 cyclic AWG.

All-optical modulation-transparent wavelength multicasting in a highly nonlinear fiber Sagnac loop mirror.

An all-optical wavelength multicasting scheme using four-wave mixing (FWM) in a highly nonlinear fiber (HNLF) Sagnac loop mirror has been demonstrated. This proposed scheme has the advantage that even when the wavelength of a multicast channel overlaps with the pump-pump generated idler, clear eye diagram can still be observed. Six and ten 10-Gb/s multicast channels, compliant with the ITU grid, are successfully obtained by using two- and three-pump lasers, respectively.

Simultaneous erasure and rewriting of a subcarrier-multiplexed label in an all-optical label swapping scheme.

A simplified all-optical label swapping scheme is proposed and experimentally demonstrated for all-optical packet switching. This scheme is based on the sub-carrier label multiplexing technique but it significantly reduces the cost and complexity of the label erasure and rewriting process at the intermediate nodes. This is accomplished using a shared interferometric filter for all wavelength channels to separate the payloads and labels as well as using gain-saturated RSOAs for label erasure and rewriting.

High-speed optical switch fabrics with large port count.

We report a novel architecture that can be used to construct optical switch fabrics with very high port count and nanoseconds switching speed. It is well known that optical switch fabrics with very fast switching time and high port count are challenging to realize. Currently, one of the most promising solutions is based on a combination of wavelength-tunable lasers and the arrayed waveguide grating router (AWGR).

Light beam coupling between standard single mode fibers and highly nonlinear photonic crystal fibers based on the fused biconical tapering technique.

We propose and experimentally demonstrate light beam coupling between a single-mode fiber (SMF) and a highly nonlinear photonic crystal fiber (HN-PCF) based on the fused biconical tapering (FBT) technique. In our experiment, a standard SMF is pre-tapered to match its propagation constant to that of a HN-PCF. In order to remove the condensation in the air holes, the temperature is increased gradually to preheat the fibers.

High-speed WDM-PON using CW injection-locked Fabry-Pérot laser diodes.

We propose a new WDM-PON architecture using Fabry-Pérot laser diodes (FP-LDs) that are injection-locked by continuous wave (CW) seed light. The modulation characteristics of the CW light injection-locked FP-LD are first investigated. Both uplink and downlink transmissions at 10 Gb/s are experimentally demonstrated using the proposed CW injection-locked FP-LDs.