Complete long-term monitoring of greenhouse gas emissions from a full-scale industrial wastewater treatment plant with different cover configurations.

The greenhouse gas (GHG) emissions from wastewater treatment plants (WWTPs), consisting mainly of methane (CH4) and nitrous oxide (N2O), have been constantly increasing and become a non-negligible contributor towards carbon neutrality. The precise evaluation of plant-specific GHG emissions, however, remains challenging. The current assessment approach is based on the product of influent load and emission factor (EF), of which the latter is quite often a single value with huge uncertainty. In particular, the latest default Tier 1 value of N2O EF, 0.016 ± 0.012 kgN2O-N kgTN-1, is estimated based on the measurement of 30 municipal WWTPs only, without involving any industrial wastewater. Therefore, to resolve the pattern of GHG emissions from industrial WWTPs, this work conducted a 14-month monitoring campaign covering all the process units at a full-scale industrial WWTP in Shanghai, China. The total CH4 and N2O emissions from the whole plant were, on average, 447.7 ± 224.5 kgCO2-eq d-1 and 1605.3 ± 2491.0 kgCO2-eq d-1, respectively, exhibiting a 5.2- or 3.9-times more significant deviation than the influent loads of chemical oxygen demand (COD) or total nitrogen (TN). The resulting EFs, 0.00072 kgCH4 kgCOD-1 and 0.00211 kgN2O-N kgTN-1, were just 0.36% of the IPCC recommended value for CH4, and 13.2% for N2O. Besides, the parallel anoxic-oxic (A/O) lines of this industrial WWTP were covered in two configurations, allowing the comparison of GHG emissions from different odor control setup. Unit-specific analysis showed that the replacement of enclosed A/open O with enclosed A/O reduced the CH4 EF by three times, from 0.00159 to 0.00051 kgCH4 kgCOD-1, and dramatically decreased the N2O EF by an order of magnitude, from 0.00376 to 0.00032 kgN2O-N kgTN-1, which was among the lowest of all full-scale WWTPs.

Characterization on vermicular graphite rate and tensile strength in vermicular graphite cast iron based on nonlinear ultrasonic technique.

Ultrasonic techniques have been widely used to detect the percentage of vermicular graphite, defects, etc. in vermicular graphite cast iron. The linear ultrasonic velocity method is the main ultrasonic method for characterizing vermicular graphite rate and tensile strength in the current study, however, it is often easy to misjudge the vermicular graphite rate due to its insignificant variation. This study explores the feasibility of using the nonlinear ultrasonic technique (NUT) to characterize the vermicular graphite rate and tensile strength. Based on the longitudinal critically refracted (LCR) wave detection model, an experimental study to detect the vermicular graphite rate and tensile strength of vermicular graphite cast iron is carried out using the nonlinear ultrasonic harmonic method, and compared with the ultrasonic velocity method. The experiment results show that the relative nonlinear parameter of the LCR wave decreases along with the increase of vermicular graphite rate and increases along with the increase of tensile strength, and it has higher detection sensitivity and resolution than ultrasonic velocity by analyzing the obtained data. The increase in the acoustic nonlinearity parameter (ANP) is related to the increase in the number of grain boundaries in the microstructure. Therefore, the relationship among microstructure, ANP, and mechanical properties of vermicular graphite cast iron can be established, and it's promising that a new approach might be developed for quickly detecting the vermicular graphite rate and corresponding tensile strength with the NUT.

A ReRAM-Based Non-Volatile and Radiation-Hardened Latch Design.

In aerospace environments, high reliability and low power consumption of chips are essential. To greatly reduce power consumption, the latches of a chip need to enter the power down operation. In this operation, employing non-volatile (NV) latches can retain circuit states. Moreover, a latch can be hit by a radiative particle in the aerospace environment, which can cause a severe soft error in the worst case. This paper presents a NV-latch based on resistive random-access memories (ReRAMs) for NV and robust applications. The proposed NV-latch is radiation-hardened with low overhead and can restore values after power down operation. Simulation results demonstrate that the proposed NV-latch can completely provide radiation hardening capability against single-event upsets (SEUs) and can restore values after power down operation. The proposed NV-latch can reduce the number of transistors in the storage cells by 50% on average compared with the other similar solutions.

Rapid detection of trace Cu2+ using an l-cysteine based interdigitated electrode sensor integrated with AC electrokinetic enrichment.

Copper is an indispensable trace element for human health. Too much or too little intake of copper ion (Cu2+ ) can lead to its own adverse health conditions. Therefore, detection of Cu2+ is always of vital importance. In this work, a simple sensor was developed for rapid detection of trace Cu2+ in water, in which L-cysteine (Cys) as a molecular probe was self-assembled on a gold interdigital electrode to form a monolayer for specific capture of Cu2+ . The interfacial capacitance of interdigital electrode was detected to indicate the target adsorption level under an AC signal working as the excitation to induce directed movement and enrichment of Cu2+ to the electrode surface. This sensor reached a limit of detection of 4.14 fM and a satisfactory selectivity against eight other ions (Zn2+ , Hg2+ , Pb2+ , Cd2+ , Mg2+ , Fe2+ , As3+ , and As5+ ). Testing of spiked tap water was also performed, demonstrating the sensor's usability. This sensor as well as the detection method shows a great application potential in fields such as environmental monitoring and medical diagnosis.