Search

To reduce injuries to greyhounds caused by collisions with fixed racing track objects such as the outside fence or the catching pen structures, padding systems are widely adopted. However, there are currently neither recognised standards nor minimum performance thresholds for greyhound industry padding systems. This research is the first of its kind to investigate the impact attenuation characteristics of different padding systems for use within the greyhound racing industry for the enhanced safety and welfare of racing greyhounds. A standard head injury criterion (HIC) meter was used to examine padding impact attenuation performance based on the maximum g-force, HIC level and the HIC duration. Initially, greyhound racing speed was recorded and analysed with the IsoLynx system to understand the potential impact hazard to greyhounds during racing which indicates the necessity for injury prevention with padding. A laboratory test was subsequently conducted to compare the impact attenuation performance of different kinds of padding. Since padding impact attenuation characteristics are also affected by the installation and substrate, onsite testing was conducted to obtain the padding system impact attenuation performance in actual greyhound racing track applications. The test results confirm that the padding currently used within the greyhound industry is adequate for the fence but inadequate when used for rigid structural members such as the catching pen gate supports. Thus, increasing the padding thickness is strongly recommended if it is used at such locations. More importantly, it is also recommended that, after the installation of padding on the track, its impact attenuation characteristics be tested according to the methodology developed herein to verify the suitability for protecting greyhounds from injury.

Urban logistics holds the lifeline of global business and consumption demand. The amount of transport vehicles rises gradually but also leads to graver emission problem. Therefore, electrified vehicles are considered as better options to substitute traditional logistics vehicles. Extended range electric logistics van (ERELV) provides a solution by providing satisfactory driving range and lower production cost than battery electric logistics van (BELV). This work aims to present a thorough energy consumption and total cost of ownership (TCO) analysis for an extended range electric van to present its energy potential. Both the ERELV and BELV mathematical models are constructed and compared, and their long-term battery degradation comparison is studied for the first time. Dynamic programming (DP) is adopted in the energy management strategy for energy consumption optimization, and the global optimization result reveals the optimal energy consumption of the ERELV. Comparative results demonstrate that the ERELV has a relatively longer drive distance, slower battery aging trend, and cheaper TCO (6.6%) when comparing to the BELV. The adoption of ERELV will promisingly reduce operating cost as the alternative transportation solution for urban logistics.

In rec ent years, Sb-based composites, as a kind of electrode alloy mechanism, have attracted more and more researchers’ attention owing to high theoretical specific capacity and reliable safety performance. However, the volume expansion of Sb-based electrode materials during charge/discharge in the process of (de)lithium leading to unstable cycling performance severely limits the progress of Sb-based electrode materials as electrode materials for commercialization. Therefore, we prepared N-doped 3D porous carbon to wrap Sb-Mo nanoparticles in a comprehensible way. By this method, the volume expansion problem of Sb-Mo nanoparticles during the (de)lithiation process can be effectively prevented, and the rate of capacity decay can be effectively mitigated. The obtained Sb-Mo@3DNC samples displayed superior electrochemical performance, especially that the Sb-Mo@3DNC700 exhibits more outstanding rate stability and long cycle performance than Sb-Mo@3DNC-600 and Sb-Mo@3DNC-800. It is worth that the Sb-Mo@3DNC-700 still possesses the reversible capacity of 352.5 mA h g−1 at the current density of 5 A g−1 and maintains the reversible capacity of 661.7 mA h g−1 after 1200 cycles at the current density of 1 A g−1.

The denitrification performance of immobilized mixed aerobic denitrifying bacteria (IMADB) was investigated. IMADB displayed strong temperature adaptability under low Carbon/Nitrogen conditions. At 5, 15, and 25 °C, the nitrate removal efficiencies of volcanic rock and polyester fiber sponge immobilized system reached 83.95%-98.25% and 89.71%-98.14%, respectively. The nitrate content removed by the carrier accounted for 41.18%-82.47% of the nitrate content removed by the immobilized system at different temperature, and played a major role in nitrate removal. The lower the temperature, the greater the role of the carrier. At the same temperature, carrier had a relatively higher richness, diversity, and evenness. Network analysis revealed that carrier species, which were positively correlated with nitrate removal efficiency, had the largest OTUs and abundance. Meanwhile, carrier had the widest niche. The total nitrogen removal efficiency of IMADB reached 56.10%-62.31% in the natural water system, highlighting a promising application prospect.

The term knuckleball in sporting jargon is used to describe a ball that has been launched with minimal spin, resulting in a trajectory that is erratic and unpredictable. This phenomenon was first observed in baseball (where the term originated) and has since been observed in other sports. While knuckleball has long fascinated the scientific community, the bulk of research has primarily focused on knuckleball as it occurs in baseball. Following the changes in the design of the soccer ball after the 2006 World Cup, knuckleball and ball aerodynamics were exploited by soccer players. This research examined the properties of a knuckleball in the sport of soccer. We designed and evaluated a system that could reproduce the knuckleball effect on soccer balls based on previous theories and characteristics outlined in our literature review. Our system is comprised of the Adidas miCoach Smart Ball, a companion smart phone app for data collection, a ball-launching machine with programmable functions, and a video-based tracking system and Tracker motion analysis software. The results from the testing showed that our system was successfully able to produce knuckleball behaviour on the football in a highly consistent manner. This verified the dynamic models of knuckleball that we outline. While a small portion of the data showed some lateral deviations (zig-zag trajectory), this erratic and unpredictable trajectory was much smaller in magnitude when compared to examples seen in professional games. The sensor data from the miCoach app and trajectory data from the Tracker motion analysis software, showed that the knuckleballs were consistently reproduced in-line with theoretical dynamics.

© 1967-2012 IEEE. In this paper, the vibration characteristics of a parallel hydraulic hybrid vehicle (PHHV) powertrain are investigated. A powertrain model is built to capture the natural frequencies and mode shapes before model reduction is conducted to simplify the system complexity. The natural frequencies and the mode shapes of the PHHV are compared with the original vehicle. Results show that with a hydraulic pump/motor (HPM) added on the powertrain, the dynamic response to engine excitation is increased only at the first natural frequency. Due to the minimum engine excitation frequency being higher than the first natural frequency of the system, resonance is avoided. The HPM also introduces excitation to the PHHV powertrain due to its instantaneous torque fluctuations. As HPM excitation is much smaller than the engine excitation, it does not produce excessive vibrations even though the powertrain frequency response is near its lowest resonant frequency. These results indicate that the NVH characteristics of the powertrain are not significantly influenced by the significant changes to the system architecture resulting from the addition of the HPM. Additionally, the HPM is not exposed to significant sources of vibration from the forced responses of the engine. Consequently, the need for substantive vibration isolation for the HPM is reduced.

Large variations load-to-curb weight ratios are linked to significant changes in parameters critical to control design for vehicle stability control system. Unique and highly customised vehicles, such as the lightweight solar car in this paper, are more susceptible to the impact of such variations when developing control methods. The purpose of this study is to study the influence of variation in loading conditions, the effect of ignoring changes in inertial parameters, and develop and compare a number of alternative vehicle stability control methods that can be applied to rear-wheel driven vehicles via in-wheel motors. In this paper a Sliding Mode Control (SMC) both nominal and when including uncertainty, Dynamic Curvature Control (DCC) and a Proportional–Integral Control (PI) strategies are compared to the baseline open-loop control case. Each controller is implemented through co-simulation via MATLAB® Simulink® and Siemens Amesim™ using a 15-DOF non-linear vehicle model. The results show that SMC achieves the best performance, whilst DCC tends to overshoot target conditions prior to settling, indicating that SMC is the preferred control strategy. It is also demonstrated that by ignoring the change in the inertial parameters in simulation environments can produce an incorrect translation of the control performance.

This study illustrates the application of a tri-axial accelerometer and gyroscope sensor device on a trampolinist performing the walking-the-wall manoeuvre on a high-performance trampoline to determine the performer dynamic conditions. This research found that rigid vertical walls would allow the trampolinist to obtain greater control and retain spatial awareness at greater levels than what is achievable on non-rigid vertical walls. With a non-rigid padded wall, the reaction force from the wall can be considered a variable force that is not constrained, and would not always provide the feedback that the trampolinist needs to maintain the balance with each climb up the wall and fall from height. This research postulates that unattenuated vertical walls are safer than attenuated vertical walls for walking-the-wall manoeuvres within trampoline park facilities. This is because non-rigid walls would provide higher g-force reaction feedback from the wall, which would reduce the trampolinist’s control and stability. This was verified by measuring g-force on a horizontal rigid surface versus a non-rigid surface, where the g-force feedback was 27% higher for the non-rigid surface. Control and stability are both critical while performing the complex walking-the-wall manoeuvre. The trampolinist experienced a very high peak g-force, with a maximum g-force of approximately 11.5 g at the bottom of the jump cycle. It was concluded that applying impact attenuation padding to vertical walls used for walking-the-wall and similar activities would increase the likelihood of injury, therefore, padding of these vertical surfaces is not recommended.

Many soft-switching techniques have been introduced for non-isolated DC-DC converters in the literature. However, most of them show the results at the low power level. In this paper, an experimental comparison of soft-switching interleaved boost DC-DC converters with auxiliary switches for high-power applications is presented. Two zero voltage transition (ZVT) boost converter prototypes with and without the third diode in the active snubber circuit are built and evaluated. Analysis, operating principles, and parameter design for the ZVT boost converter without using the third diode in the snubber circuit are provided. The experimental verifications from laboratory tests of equivalent 10-kW/50-kHz interleaved boost converters based on discrete SiC MOSFETs and diodes are given. The results are obtained for the input voltage of 200 V and the output voltage range from 320 V to 530 V. The efficiency and power loss distribution of the converters are compared.

This study investigates and compares the acoustic signatures of a traditional wire-cable-pulled lure system and two alternative battery-operated lure systems jointly developed by Covey Associates Pty. Ltd. and Steriline Pty. Ltd. to eliminate the hazardous steel-wire cable and make the sport of greyhound racing safer for greyhounds, participants and spectators. The acoustical measurements of these three lure systems were conducted at the Murray Bridge greyhound racing track. The lure sounds were measured by the high-frequency Brüel &amp, Kjær (B&amp, K) Type 4191 microphones for the 395 m and 455 m starts at two positions: within the starting box and on the track adjacent to the starting boxes. The measurements capture the sounds that the greyhounds hear before and after the opening of the starting box gate. The frequency-domain analysis and sound quality analysis were conducted to compare the lure sounds. It was found when the battery-lure was installed with all nylon rollers, it presented less sound energy and lower frequency than the traditional wire-cable-pulled lure. When two of the nylon rollers were replaced with steel rollers, the battery-operated lure emitted a louder and higher frequency sound than the traditional wire-cable-pulled lure. The different acoustic characteristics of these lure systems suggest future research is warranted on the reaction of greyhounds to different lure sounds, particularly their excitement level within the starting box as the lure approaches. This initial research also suggests some greyhounds may not clearly hear the battery-operated lure with all nylon rollers approaching the starting boxes and the timing of these greyhounds to jump may be delayed, particularly during high wind conditions.

The power on gear shift control of a parallel hydraulic hybrid vehicle (PHHV) is researched in this paper. A multibody dynamic model is built to capture the main vibration characteristics of PHHV powertrain, based on which the power on gear shift control strategy is designed and verified. To avoid the vehicle driving torque interruption during gear shift, power on gear shift control strategy is designed. In the control strategy, hydraulic pump/motor (HPM) compensates the engine torque when the engine clutch is disengaged for gear shift. The engine clutch engagement process is carefully controlled by LQR control strategy to mitigate the vehicle powertrain vibration and improve the vehicle driving comfort. Extended Kalman filter (EKF) is adopted to estimate the PHHV parameters required by LQR control. The available HPM torque depends on its working pressure which varies a lot with different accumulator state of charge. So the HPM torque compensation capability is investigated by analysing the traction force requirement during gear shift. To obtain the gear shift traction force demand, a gear shift schedule considering both vehicle fuel economy and dynamic performance is designed. The simulation results show that the HPM could satisfy most of the torque compensation requirements during gear shifts with the designed gear shift schedule in typical driving cycles.

This paper investigates the application of adaptive tuned vibration absorbers (ATVAs) to lightly damped automotive powertrains. To achieve this, a vibration characteristic analysis of a dual lay-shaft dual clutch transmission (DCT)-equipped powertrain system was performed, including a natural frequency evaluation and sensitivity studies. Transient responses due to gear changes and variations of both the gear ratio and engine speed were also evaluated. The results demonstrate that the impact of ATVAs on transient responses during gear changes is minimal, suggesting that these short-duration transients are outside the scope of application for ATVAs. However, as excitation forces originate from the engine, speed has a significant impact on excitation frequency. Furthermore, the gear ratios significantly influence the engine operating range and natural frequency in any particular gear. Therefore, variations of engine speeds and gear ratios are the main influencing factors affecting the dominant excitation frequency. Consequently, the relationships among the system natural frequencies, the dominant external excitation frequency and the inherent frequency of the ATVA are comprehensively studied. By investigating the relationships among the dominant external excitation frequency and system natural frequencies and the system sensitivity analysis results, the installation position, stiffness range and optimal frequency tuning scheme of the ATVA can be determined. The results were applied to a DCT powertrain with continuously changing engine speeds and an ATVA with corresponding variable stiffness, and a frequency tuning scheme is installed on the powertrain. By comparing the simulation results, the effectiveness and reliability of the presented method can be verified.

This paper compares the energy economy and vertical vibration characteristics of in-wheel drive electric vehicles (IEVs), in-wheel drive electric hydraulic hybrid vehicles (IHVs) and centralized drive electric vehicles (CEVs). The dynamic programming (DP) algorithm is used to explore the optimal energy consumption of each vehicle. The energy economy analysis shows that the IEV consumes more energy than the CEV due to its relatively lower electric motor efficiency, even with fewer driveline components. The IHV consumes much more energy than the IEV and CEV because of the energy loss in the hydraulic driveline. The vertical vibration analysis demonstrates that both IEV and IHV degrade the vehicle driving comfort due to increased unsprung mass. Taking the advantage of high power density of the hydraulic motor, IHV have less unsprung mass when compared with the IEV, which helps to mitigate the vibration problems caused by increased unsprung mass.

© 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group. Parallel hydraulic hybrid vehicles (PHHVs) integrate conventional engines with a hydraulic pump/motor (HPM) to drive the vehicle independently or in combination. To improve the comfortability and drivability during mode switching from hydraulic driving mode to engine driving mode, this paper proposes a coordinated control strategy for the engine, clutch and HPM. To capture the transient behaviour of the powertrain, a medium-duty PHHV dynamic model is established. Based on a typical PHHV powertrain layout, the mode switching process is analysed and divided into five phases. Control strategies are designed for each phase, respectively.LQR-based closed-loop control strategy is adopted to analyse the effect of clutch engaging speed on vehicle jerk, clutch frictional work and energy consumption. HPM output torque is adjusted to compensate the engine clutch drag torque, with the aim maintaining good drivability. To do this, constant vehicle acceleration is selected as the indicator of stable output torque. The simulation results demonstrate that by using the HPM to compensate the engine clutch drag torque, vehicle drivability is guaranteed during mode switching. From the comparison between different LQR weighting matrices, multiple options are available to drivers on drivability and comfortability during mode switching.

Parallel hydraulic hybrid vehicles have the benefit of reduced fuel consumption and emissions. However, the hydraulic driving system changes the vibration characteristics of the vehicle powertrain. To study the influence that the hydraulic driving system has on the vehicle powertrain, a multibody dynamic model is built by the lumped mass method in this chapter. The model considers the dual functional swashplate hydraulic pump/motor inertia and its clutch stiffness. Through the eigenvalue method, the natural frequencies and mode shapes of the vehicle powertrain are attained and compared with the conventional vehicle. The results show that the hydraulic driving system mainly changes the lower-order natural frequencies and mode shapes, whilst the higher-order natural frequencies and mode shapes are not affected. A new natural frequency and its corresponding mode shape are generated by the hydraulic driving system, to which further attention should be paid because the hydraulic motor/pump is the node with the biggest vibration in this mode shape.

Double bounce is an unusual and potentially very hazardous phenomenon that most trampoline users may have experienced, yet few would have really understood how and why it occurs. This paper provides an in-depth investigation into the double bounce. Firstly, the static and dynamic characteristics of a recreational trampoline are analysed theoretically and verified through experiments. Then, based on the developed trampoline dynamic model, double bounce simulation is conducted with two medicine balls released with different time delays. Through simulation, the process of double bounce is presented in detail, which comprehensively reveals how energy is transferred between users during double bounce. Furthermore, the effect of release time delay on double bounce is also presented. Finally, we conducted an experiment which produced similar results to the simulation and validated the reliability of the trampoline dynamic model and double bounce theoretical analysis.

Hydraulic hybrid technologies improve the fuel economy of city-use medium duty vehicles by recovering braking energy and reusing it for driving, most notably vehicle launching. In this paper, a parametric design of hydraulic driving system for a medium duty truck is conducted based on its power demand in typical urban driving cycles. The braking control strategy is designed considering both the safety regulations and braking energy recovery rate. The proportional relationship of hydraulic pump/motor output torque and its working pressure is considered when designing the braking control strategy. The influence of the high pressure accumulator minimum working pressure and the corresponding gas volume at the minimum pressure on the braking energy recovery rate is analyzed. The simulation results show that the proposed hydraulic driving system and braking control strategy helps greatly increase the braking energy recovery rate. Besides, different vehicle mass and load distributions are investigated to analyze the regenerative braking effect on various loading conditions.

An octanuclear copper complex, [Cu8(L)10(OH)4Cl2·(DMF)2]·2DMF ( HL= 4-(2-bromophenyl)-2H-1,2,3-triazole) has been synthesized. Single crystal diffraction reveals that it crystallizes in the triclinic space group P − 1. The complex shows fluorescent quenching compared with the free ligand. The {Cu8} displays overall strong antiferromagnetic (AF) coupling via hydroxyl groups, κ2-N,N-trizaoles and κ3-N,N,N-trizaoles, and the complex exhibits AF ordering under low temperature with TN = 8.5 K.

Field research on the performance of pollutant removal and the structure of the microbial community was carried out on a drinking water reservoir. After one month of operation of a water-lifting aeration system, the water temperature difference between the bottom and the surface decreased from 9.9 to 3.1 &deg, C, and the concentration of the dissolved oxygen (DO) in the bottom layer increased from 0 to 4.2 mg/L. The existing stratification in the reservoir was successfully eliminated. Total nitrogen (TN), total phosphorus (TP), and total organic carbon (TOC) concentrations were reduced by 47.8%, 66.7%, and 22.9%, respectively. High-throughput sequencing showed that Proteobacteria, Bacteroides, and Actinomycetes accounted for 67.52% to 78.74% of the total bacterial population. Differences in the bacterial changes were observed between the enhanced area and the control area. With the operation of the water-lifting aeration system, the populations of bacteria of the main genera varied temporally and spatially. Principal component analysis pointed out a clear evolution in the vertical distribution of the microbial structure controlled by the operation of the aeration system. Permutational analysis of variance showed a significant difference in the microbial community (p &lt, 0.01). Redundancy analysis showed that physical (water temperature, DO) and chemical environmental factors (Chl-a, TOC, TN) were the key factors affecting the changes in the microbial communities in the reservoir water. In addition, a hierarchical partitioning analysis indicated that T, Chl-a, ORP, TOC, pH, and DO accounted for 24.1%, 8.7%, 6.7%, 6.2%, 5.8%, and 5.1% of such changes, respectively. These results are consistent with the ABT (aggregated boosted tree) analysis for the variations in the functional bacterial community, and provide a theoretical basis for the development and application of biotechnology.

© 2019 IEEE. Electric vehicles with stepped automatic transmissions provide benefits for improve drive performance and lower energy consumption. To deliver the desired operational functionality of power-on shifting for all driving states, this paper presents a novel methodology for the achievement of power-on gear shifts during regenerative braking events in electric vehicles equipped with multi-speed transmissions. Separate algorithms are developed for upshift and downshift events, where the control of clutches is considered for both torque and inertia phases of these events. Consideration is given primarily to the delivery of negative friction torque through the clutches during the inertia phase of gear change. A multi-body dynamic model of a dual clutch transmission equipped powertrain is then developed, including a DC equivalent motor model and piecewise clutch models, to evaluate the performance of these clutch control algorithms. Results of these simulations demonstrate the effectiveness of these shift control strategies and the capacity to maintain brake torque to the road during shift events.

© 2019 SAE International. All Rights Reserved. In this paper, hydraulic driving system parameters of a parallel hydraulic hybrid vehicle are designed based on the regenerative braking requirement. Torque, speed and power demands during typical driving cycles are analyzed. The braking control strategy is designed considering both the braking safety and braking energy recovery efficiency. The hydraulic braking torque is determined by the braking control strategy. The proportional relationship of hydraulic pump/ motor output torque and its working pressure is considered. Through simulation with typical city driving cycles, most braking energy can be recovered by the proposed hydraulic driving system and braking control strategy.

A novel adsorbent Sn-MOF synthesized through hydrothermal method at 170 ℃, was used in the removal of Acid Red 3R (AR3R) from the aqueous solution. The physicochemical properties of the Sn-MOF were determined. The adsorption kinetics, mechanism and regeneration were further investigated in the adsorption process. It showed an effective adsorption for AR3R with the capacity of 141.88 mg·g−1. The chemisorption is significant in the process and the adsorption of AR3R is limited by both the intraparticle diffusion and the film diffusion. The adsorption capacity of Sn-MOF that treated by photocatalytic regeneration does not decrease obviously after six cycles.

Integrating a multispeed transmission into the electric drive system provides the potential of ulteriorly improving the overall efficiency of battery electric vehicles (BEVs). In this paper, we propose a novel two-speed planetary automated manual transmission (PAMT) which features a more compact mechanical structure than clutchless automated manual transmission (CLAMT) and easier gear shifting control than power-on transmissions. To present the transient behaviours during the gear shifting, a detailed and original dynamical model of the electrified powertrain is developed, including an electric machine (EM), a two-speed PAMT, synchronizer mechanisms, driveline and vehicle, etc. Afterwards, the gear shifting control system is devised, and the gearshift process is orderly divided into five stages based on the proposed control strategy. Next, three alternative planning torque trajectories, i.e., the third-degree polynomial (TDP), the fifth-degree polynomial (FDP) and the seventh-degree polynomial (SDP), are proposed to control the EM torque at the first and the fifth stages of the gear shifting respectively. Subsequently, a series of simulations are performed to validate which candidate torque trajectory is capable of achieving the optimal gear shifting quality in term of reducing the longitudinal vehicle jerk and shift durations. This study provides a beneficial reference for the development of BEVs’ transmission system.

With the sustained technology advancement in the power battery, battery electric vehicles (BEVs) are considered as the most advisable alternatives of their internal combustion engine (ICE) counterparts. Research reveals that the implementation of multispeed transmissions for BEVs can reduce the vehicle energy consumption, improve the vehicle dynamic performance and downsize the battery package and the driving motor volume. Considering the potential advantages of multispeed transmissions equipped BEVs, this paper presents an investigation into the optimal coordinating gearshift control of a seamless two-speed transmission for BEVs. Firstly, to achieve the gearshift transient behaviour, the mathematical model of the powertrain system is established. Next, model-based gearshift tactics are proposed for the torque phase and the inertia phase respectively. Subsequently, the proposed control tactics based optimal controllers are developed to achieve high-quality gearshift in the whole gear shifting process. To be more specific, in the torque phase, the controller aims at optimising dual objectives together, namely the vehicle jerk and friction work, and the control objective of the inertia phase only focuses on decreasing the friction work due to the coordinating gear shifting tactic. Finally, based on available sensor signals, sliding mode observers are employed to estimate unmeasurable torque as feedback information for the optimal controllers in different gear states. Simulation results demonstrate that the devised control approaches can promote gear change performance comprehensively.

Aeration and mixing have been proven as effective in situ water quality improvement methods, particularly for deep drinking water reservoirs. While there is some research on the mechanism of water quality improvement during artificial mixing, the changes to water quality and the microbial community during the subsequent continuous mixing process is little understood. In this study, we investigate the mechanism of water quality improvement during the continuous mixing process in a drinking water reservoir. During this period, we found a reduction in total nitrogen (TN), total phosphorus (TP), ammonium-nitrogen (NH4-N), iron (Fe), manganese (Mn), and total organic carbon (TOC) of 12.5%&ndash, 30.8%. We also measured reductions of 8.6% and 6.2% in TN and organic carbon (OC), respectively, in surface sediment. Microbial metabolic activity, abundance, and carbon source utilization were also improved. Redundancy analysis indicated that temperature and dissolved oxygen (DO) were key factors affecting changes in the microbial community. With intervention, the water temperature during continuous mixing was 15 &deg, C, and the mixing temperature in the reservoir increased by 5 &deg, C compared with natural mixing. Our research shows that integrating and optimizing the artificial and continuous mixing processes influences energy savings. This research provides a theoretical basis for further advancing treatment optimizations for a drinking water supply.

A field scale experiment was performed to explore the nitrogen removal performance of the water and surface sediment in a deep canyon-shaped drinking water reservoir by operating WLAs (water-lifting aerators). Nitrogen removal performance was achieved by increasing the densities and N-removal genes (nirK and nirS) of indigenous aerobic denitrifiers. After the operation of WLAs, the total nitrogen removal rate reached 29.1 &plusmn, 0.8% in the enhanced area. Ammonia and nitrate concentrations were reduced by 72.5 &plusmn, 2.5% and 40.5 &plusmn, 2.1%, respectively. No nitrite accumulation was observed. Biolog results showed improvement of carbon metabolism and carbon source utilization of microbes in the enhanced area. Miseq high-throughput sequencing indicated that the denitrifying bacteria percentage was also higher in the enhanced area than that in the control area. Microbial communities had changed between the enhanced and control areas. Thus, nitrogen removal through enhanced indigenous aerobic denitrifiers by the operation of WLAs was feasible and successful at the field scale.

We studied the influences of water pressure and temperature on denitrification, and detected its nitrogen removal characteristics for providing evidence to remediate the micro-polluted reservoir source water.Mixed oligotrophic aerobic denitrification bacteria was obtained through enrichment, domestication, and screening processes, which was isolated from sediment in the source water reservoir; and the nitrogen removal characteristics was detected by an in-situ biological inoculation experiment (DO at 3–8 mg/L).Nitrate of the hard flask system (with water pressure influence) was removed completely, however, at 0.5, 5 m water layer, the nitrate removal rate of the soft flask reached 90.66%, 100%, other layers reached 99.61%, 80.55%, 67.01%, 64.73%. No nitrite accumulated. Because of bacteria death, ammonia had a slight increase. At the end of the experiment, in the 0.5, 5.0, 7.5, 10.0, 12.5 and 15.0 m water layer, the total nitrogen removal rates of hard flask reached 50.11%, 61.49%, 56.24%, 44.50%, 36.80% and 38.73%, however, that of soft system reached 33.47%, 60.61%, 43.98%, 36.28%, 27.52% and 28.57%. OD600 and pH first rose and then dropped. The mixed bacteria had prominent nitrogen removal ability between 11 °C and 30 °C.The mixed bacteria have a strong adaptability to temperature and the water pressure has a disadvantage to the nitrogen removal.

Four new Zn(II) and Cu(II) coordinated polymers ([ZnL2N3]ClO4 (1), [Cu2L2(CH3CN)]Cl4 (2) [CuL](NO3)2 (3), [Cu(H2O)L](SO4) (4) L = 2-((4-phenyl-2H-1,2,3-triazol-2-yl)methyl) pyridine (ptmp)) have been reported. All the compounds have been characterized by IR spectrum, elemental analyses and X-ray crystallography diffraction. Single-crystal X-ray diffraction analyses show that one-dimensional polymers are formed in these four complexes. Chain-like structures are formed in complex 1, 2 and 3, which are connected by azide, chloride and nitrate anions, respectively. In complex 4, one-dimensional left-handed polymer is formed by a μ2-SO4 bridge. The fluorescent and electrochemical properties of these four complexes were investigated. It was found that these three Cu(II) complexes displayed a quenching of fluorescence, while Zn(II) complex exhibited a clear enhanced fluorescence.

Frequency offset estimation for binary continuous phase modulation (CPM) signals is investigated in this paper and a feedforward non-data-aided (NDA) and non-timing-aided frequency offset estimation algorithm is proposed. In the algorithm a new autocorrelation function is used for frequency estimation. The delay value in the function is carefully selected depending on the parameters of the CPM signal. And then the frequency offset is estimated based on the integration of the autocorrelation function which is independent of the timing delay. Simulation results show that the proposed algorithm performs well for CPM signals with higher modulation index and has better performance than the existing feedforward NDA and non-timing-aided frequency estimation algorithm. Additionally, the performance gain is more significant when the signal-to-noise ratio gets higher.