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.

Hotspots Reduction for GALS NoC Using a Low-Latency Multistage Packet Reordering Approach.

Traffic splitting enabled by Globally Asynchronous Locally Synchronous (GALS) Network-on-chip (NoC) brings multipath routing capability, which significantly increases link bandwidth at the cost of out-of-order packet delivery. Solving the packet reordering problem is one of the keys to ensure the quality of service (QoS) for NoC. However, traditional packet reordering approaches rely on local reorder buffer, causing on-chip hotspots, which aggravates chip aging and even leads to interconnection failures. In this paper, we present a multistage packet reordering (MPR) approach, which cannot only reduce the transmission latency but also effectively reduces hotspots caused by local reordering. Specifically, we propose multistage reordering buffer (MRB) by reusing channel buffers for implementing MPR. Experimental results show that our proposed approach achieved improved thermal efficiency with reduced hardware resource consumption.

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.

A Study on the Decay Model of Multi-Block Taxi Travel Demand under the Influence of Major Urban Public Health Events.

A sudden major public health event is likely to have a negative impact on public transport travel for residents, with public travel modes such as the metro and conventional buses experiencing varying degrees of decline in patronage. As a complement to public transport, taxi travel will suffer the same impact. Land use and population density among various functional blocks in a city are different, and therefore their changing rates in taxi travel demand are varied. This paper reveals the taxi travel demand correlations between urban blocks and then constructs a taxi travel demand decay model based on the Dynamic Input-Output Inoperability Model (DIIM) to simulate the decay degree of taxi travel demand in each block. When a major public health event occurs, the residential panic levels in different functional blocks may vary. It results in variable changing speeds of residential travel demand in each block. Based on this assumption, we use the intensity of travel demand as a correlation strength factor between blocks, and equate it with the technical coefficient in the DIIM model. We also define other variables to serve in model construction. These variables include the decay degree of travel demand intensity, residential travel willingness, coefficient of travel demand decay, derivative coefficient of travel demand interdependency, and demand perturbation coefficient. Lastly, we select a central area of Ningbo as the study area, and use taxi travel data in Ningbo during the COVID-19 pandemic of 2020 as input, simulate taxi travel demand dynamics, and analyze the accuracy and sensitivity of the model parameters. The relative errors between the five types of blocks and the actual decay of travel demand intensity are 8.3%, 3.8%, 8.7%, 5.5%, and 5.3%, respectively, which can basically match the actual situation, proving the validity of the model. The results of the study reveal the pattern of taxi travel demand decay among various blocks after major public health events. It provides methodological reference for decision makers to understand the development trend of multi-block taxi travel demand, so as to help form effective emergency plans for different blocks.

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.

Plasmon enhanced photocatalytic and antimicrobial activities of Ag-TiO2 nanocomposites under visible light irradiation prepared by DBD cold plasma treatment.

Silver nanoparticles (Ag NPs) have been deposited on powder P25 by a novel two-step method involving a precipitation reaction and atmospheric pressure dielectric barrier discharge (DBD) cold plasma treatment without the use of any environmentally and biologically hazardous reducing agents. The silver precursor is formed in the processing of precipitation reaction and then completely reduced to the metallic state by atmospheric pressure DBD cold plasma treatment as proved by X-ray photoelectron spectroscopy, UV-Visible absorption spectra and HRTEM analyses. TEM images indicate that the Ag NPs with average diameter of 3.7 nm were deposited on powder P25 with high dispersion although no reducing agents, stabilizers or surfactants were used. The prepared products show remarkable improvement for methylene blue (MB) photodegradation and effective inhibition of bacterias against Escherichia coli and Staphylococcus aureus.

TiO2 surfaces self-doped with Ag nanoparticles exhibit efficient CO2 photoreduction under visible light.

Doping with intrinsic defects to enhance the photocatalytic performance of TiO2 has recently attracted attention from many researchers. In this report, we developed an original approach to realise stabilized surface doping using intrinsic defects with the loading of Ag nanoparticles (AgNPs) on the surface. Herein, atmospheric pressure dielectric barrier discharge (DBD) cold plasma was used to help load the AgNPs, and ethanol treatment was used to introduce intrinsic defects (oxygen vacancies and Ti3+) on the surface of materials. This method avoids environmentally hazardous reducing regents and is undertaken under atmospheric pressure, thus reducing energy-consuming and complex operation. We combine the advantages of noble metal nanoparticles and surface doping to enhance the photocatalytic performance under the visible light. The characterization of the materials indicates that the loading of AgNPs and introduction of intrinsic defects can change the electronic structure of the composite material and improve its efficiency. The samples show significant enhancement in CO2 photoreduction to obtain CO and CH4, with yields reaching 141 µmol m-2 and 11.7 µmol m-2, respectively. The formation mechanism of the method for TiO2 modification and CO2 reduction is also discussed.

A simulation study of the impact of the public-private partnership strategy on the performance of transport infrastructure.

The choice of investment strategy has a great impact on the performance of transport infrastructure. Positive projects such as the "Subway plus Property" model in Hong Kong have created sustainable financial profits for the public transport projects. Owing to a series of public debt and other constraints, public-private partnership (PPP) was introduced as an innovative investment model to address this issue and help develop transport infrastructure. Yet, few studies provide a deeper understanding of relationships between PPP strategy and the performance of such transport projects (particularly the whole transport system). This paper defines the research scope as a regional network of freeway. With a popular PPP model, travel demand prediction method, and relevant parameters as input, agents in a simulation framework can simulate the choice of PPP freeway over time. The simulation framework can be used to analyze the relationship between the PPP strategy and performance of the regional freeway network. This study uses the Freeway Network of Yangtze River Delta (FN-YRD) in China as the context. The results demonstrate the value of using simulation models of complex transportation systems to help decision makers choose the right PPP projects. Such a tool is viewed as particularly important given the ongoing transformation of functions of the Chinese transportation sector, including franchise rights of transport projects, and freeway charging mechanism.

The complete mitochondrial genome sequences of Chelodina rugosa and Chelus fimbriata (Pleurodira: Chelidae): implications of a common absence of initiation sites (O(L)) in pleurodiran turtles.

Within the order Testudines, while phylogenetic analyses have been performed on the suborder Cryptodira with complete mitochondrial genomes (mitogenomes), mitogenomic information from another important suborder Pleurodira has been inadequate. In the present study, complete mitochondrial DNA (mtDNA) sequences of two chelid turtles Chelodina rugosa and Chelus fimbriata were firstly determined, the lengths of which were 16,582 and 16,661 bp respectively. As the typical vertebrate mitogenome, both mtDNAs consist of 13 protein coding genes, 2 ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and a long noncoding region (control region, CR). However, the initiation sites for light-strand replication (O(L)), which has been identified in all reported Cryptodire mitogenomes, were not found in the putative position of the two chelid turtles and African helmeted turtle Pelomedusa subrufa. The results suggested that the absence of mitogenomic initiation sites (O(L)) could be a characteristic of Pleurodira. Phylogenetic relationships of chelid turtles and other turtles were reconstructed using the reported mitogenomes. Both maximum likelihood (ML) and Bayesian inference (BI) analyses suggested the monophyly of Pleurodira and Cryptodira as well as a sister group relationship between the two chelid turtles with strong statistical support. This phylogenetic framework was also utilized to estimate divergence dates among lineages using relaxed-clock methods combined with fossil evidence. Divergence estimates revealed that genus Chelodina diverged from genus Chelus in Late Cretaceous (~83 million years ago (mya)), and the time is consistent with the vicariance of the fragments which was caused by Gondwana split.