Search

The data incest problem causes inter-estimate correlation during data fusion processes, which yields inconsistent data fusion results. Especially in the multi-sensor multi-vehicle (MSMV) system, the data incest problem is serious due to multiple relative position estimations, which not only lead to pessimistic estimation but also cause additional computational overhead. In order to address the data incest problem, we propose a new data fusion method termed the interval split covariance intersection filter (ISCIF). The general consistency of the ISCIF is proven, serving as supplementary proof for the split covariance intersection filter (SCIF). Moreover, a decentralized MSMV localization system including absolute and relative positioning stages is designed. In the absolute positioning stage, each vehicle uses the ISCIF algorithm to update its own position based on absolute measurements. In the relative position stage, the interval constraint propagation (ICP) method is implemented to preprocess multiple relative position estimates and initially prepare input data for ISCIF. Then, the proposed ISCIF algorithm is employed to realize relative positioning. In addition, comparative simulations demonstrate that the proposed method can achieve both accurate and consistent results compared with the state-of-the-art methods. [ABSTRACT FROM AUTHOR]

Metal migration and precipitation in hydrothermal fluids are important topics in economic geology. The Hongling polymetallic deposit comprises one of the most important parts of the Huanggangliang–Ganzhuermiao polymetallic metallogenic belt, which is in eastern Inner Mongolia. Except for lead–zinc skarn, minor cassiterite in the skarn and disseminated W–Sn mineralization in granitic rocks have also been found. The dominant Sn–W mineralization is in the northern part of the deposit, occurring as disseminated wolframite and cassiterite in aplite hosted in Mesozoic granite porphyry. The aplite together with pegmatite K-feldspar–quartz comprises vein dikes hosted in the granite porphyry, providing evidence for the transition from melt to fluid. The veins, dikes, and Sn–W mineralization in the aplite provide an opportunity to investigate fluid exsolution and the mechanics of metal precipitation. Based on field observations, the micrographic and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) results of the vein dikes, chronology, and the whole-rock geochemistry of the host rock, together with the fluid inclusion results, this paper discusses the characteristics of the causative magma, the mechanics of fluid exsolution and W–Sn precipitation. Our results show that the causative magma is of highly fractionated A-type granite affinity and has an intrusive age of late Mesozoic (133.3 ± 0.86 Ma). The magmatic evolution during shallow emplacement led to immiscibility between highly volatile, high-silica, and W- and Sn-enriched melts from the parent magma, followed by fluid exsolution from the water-rich melt. The alkaline-rich fluid exsolution led to a change in the redox state of the magma and the chilling of the melt. Fluid boiling occurred soon after the fluid exsolution and was accompanied by the degassing of CO2. The boiling and escape of CO2 from the fluid led to changes in fluid redox and W and Sn precipitation; thus, the W and Sn mineralization are mostly hosted in causative intrusions or peripheral wall rocks, which can be used as indicators for Sn–W exploration in the area. [ABSTRACT FROM AUTHOR]

—In this paper, a class-F 23 VCO using nonlinear-capacitance transforming technique to simultaneously achieve low phase noise and a wide tuning range is proposed. The phase noise degradation due to the nonlinearity of the switched capacitor in the class-F 23 oscillator is analyzed and quantitatively derived. The phase noise contributed by the nonlinear capacitance can be suppressed by using the proposed nonlinear-capacitance transformation technique. In order to achieve low phase noise over a wide bandwidth, the asymmetric-toggling method is utilized to achieve optimal capacitance ratios across the entire frequency range. Implemented in a 40-nm CMOS process, the proposed oscillator exhibits 41.2 % tuning range from 2.58 GHz to 3.92 GHz while consuming 13.8 mW–14.9 mW power dissipation. The phase noises at 2.58 GHz and 3.92 GHz oscillation frequencies are −136.4 dBc/Hz and −129.6 dBc/Hz at 1-MHz offset. The minimum phase noise is −157.2 dBc/Hz at 10 MHz offset, corresponding to an FoM of 194.1 dBc/Hz and FoM T of 206.4 dBc/Hz. [ABSTRACT FROM AUTHOR]

Chemical oxygen demand (COD) is widely used as an organic pollution indicator in wastewater treatment plants. Large amounts of organic matter are removed during treatment processes to meet environmental standards, and consequently, substantial greenhouse gases (GHGs) such as methane (CH4) are released. However, the COD indicator covers a great amount of refractory organic matter that is not a pollutant and could be a potential carbon sink. Here, we collected and analysed COD data from 86 worldwide municipal wastewater treatment plants (WWTPs) and applied a model published by the Intergovernmental Panel on Climate Change to estimate the emission of CH4 due to recalcitrant organic compound processing in China's municipal wastewater treatment systems Our results showed that the average contribution of refractory COD to total COD removal was 55% in 86 WWTPs. The amount of CH4 released from the treatment of recalcitrant organic matter in 2018 could have been as high as 38.22 million tons of carbon dioxide equivalent, which amounts to the annual carbon sequestered by China's wetlands. This suggests that the use of COD as an indicator for organic pollution is undue and needs to be revised to reduce the emission of GHG. In fact, leaving nontoxic recalcitrant organic matter in the wastewater may create a significant carbon sink and will save energy during the treatment process, aiming at carbon neutrality in the wastewater treatment industry. [ABSTRACT FROM AUTHOR]

A Digital-to-Time Converter based (DTC-based) fractional- N digital phase-locked loop (DPLL) using probability-density-shaping (PDS) spur immunity and quantization phase (Q-noise) reduction techniques is presented. PDS-DSM is used to generate a loop spur immunity control code for DTC. A diff type dither is proposed to further suppress the fractional spur. The loop nonlinearity will not cause fractional spurs if certain conditions are obeyed. Moreover, to reduce the quantization noise, a configurable Phase Interpolator (PI) with 0.125/0.25/0.5/1.0 division step is integrated with a multi-module divider (MMDIV), leading to an 18-dB Q-noise suppression. A reference doubler with duty-cycle correction is adopted to further reduce phase noise. The fractional spurs are greatly mitigated by combining the PDS-DSM and phase interpolator. A DPLL prototype using the aforementioned techniques was designed in a 40-nm standard CMOS process, occupying a 0.99 mm2 silicon area. At a near-integer- N frequency, i.e., near 2.23 GHz, with PDS turned on and off, the post-layout simulated fractional spur is −59 dBc and −20 dBc, respectively. The RMS jitter of the whole chip is 4.218 ps, corresponding to a figure of merit (FOM) of −220.5 dB. [ABSTRACT FROM AUTHOR]

Monoterpenes are among the important natural plant terpenes. Monoterpenes usually have the characteristics of volatility and strong aroma. β-Myrcene and its isomer (E)-β-ocimene are typical acyclic monoterpenes. They are high-value monoterpenes that have been widely applied in foods, cosmetics, and medicines. However, large-scale commercial production of β-myrcene and (E)-β-ocimene is restricted by their production method that mainly involves extraction from plant essential oils. Currently, an alternative synthetic route utilizing an engineered microbial platform was proposed for effective production. This study used a Saccharomyces cerevisiae strain previously constructed for squalene production as the starting strain. Farnesyl diphosphate synthase (Erg20) expression was weakened by promoter replacement and screened for optimal myrcene synthase (MS) and ocimene synthase (OS) activities. In the resulting S. cerevisiae engineered for β-myrcene and (E)-β-ocimene synthesis, titers of β-myrcene and (E)-β-ocimene were enhanced by a fusion expressing a mutant Erg20* with the obtained monoterpene synthase and optimizing the added solvent in a two-phase fermentation system. Finally, by scaling up in a 5-L fermenter, 8.12 mg/L of β-myrcene was obtained, which was first reported in yeast, and 34.56 mg/L of (E)-β-ocimene was obtained, which is the highest reported to date. This study provides a new synthesis route for β-myrcene and (E)-β-ocimene. [ABSTRACT FROM AUTHOR]

Monoterpenes are among the important natural plant terpenes. Monoterpenes usually have the characteristics of volatility and strong aroma. β-Myrcene and its isomer (E)-β-ocimene are typical acyclic monoterpenes. They are high-value monoterpenes that have been widely applied in foods, cosmetics, and medicines. However, large-scale commercial production of β-myrcene and (E)-β-ocimene is restricted by their production method that mainly involves extraction from plant essential oils. Currently, an alternative synthetic route utilizing an engineered microbial platform was proposed for effective production. This study used a Saccharomyces cerevisiae strain previously constructed for squalene production as the starting strain. Farnesyl diphosphate synthase (Erg20) expression was weakened by promoter replacement and screened for optimal myrcene synthase (MS) and ocimene synthase (OS) activities. In the resulting S. cerevisiae engineered for β-myrcene and (E)-β-ocimene synthesis, titers of β-myrcene and (E)-β-ocimene were enhanced by a fusion expressing a mutant Erg20* with the obtained monoterpene synthase and optimizing the added solvent in a two-phase fermentation system. Finally, by scaling up in a 5-L fermenter, 8.12 mg/L of β-myrcene was obtained, which was first reported in yeast, and 34.56 mg/L of (E)-β-ocimene was obtained, which is the highest reported to date. This study provides a new synthesis route for β-myrcene and (E)-β-ocimene. [ABSTRACT FROM AUTHOR]

The organic matter together with ammonium has become a major concern in the applications of ANaerobic AMMonium OXidation (ANAMMOX) process because of its possible adverse influences. The robustness of ANAMMOX against organic matter interference was found by accident in the ANAMMOX Granule Sludge Bed (GSB) reactor. Under inorganic conditions, Autotrophic ANAMMOX Granular Sludge (AGS) was cultivated, in which ANAMMOX accounted for 89.7% of the total nitrite removal. The bioreactor based on AGS showed an intriguing resistance to organic matter interference, with a stable volumetric nitrogen removal rate (NRR) for a surprisingly long time (|ΔNRR| ≤ 10% for 33 days). Under organic conditions, however, AGS gradually shifted to mixotrophic ANAMMOX granular sludge (MGS), in which ANAMMOX accounted for 51.9% of the total nitrite removal. The bioreactor based on MGS was sensitive to organic matter interference, with a decrease by 20.9% in NRR when the volumetric organic loading rate was 7.5 kg COD/(m 3 d). Beneath the threshold COD/NO 2 − -N ratio of 1.71, ANAMMOX played its dominant role in MGS (contributed to 68.9% of the total nitrite removal). While above the threshold ratio, ANAMMOX was dramatically inhibited (contributed to less than 34.1% of the total nitrite removal), but it did not disappear completely as expected. The discovery of ANAMMOX robustness in AGS is significant for the development of new ANAMMOX process suitable for the treatment of ammonium-containing wastewaters with coexistence of organic matter. [ABSTRACT FROM AUTHOR]

2-Keto- L -gulonic acid (2-KLG), the direct precursor of vitamin C, can be synthesized from L -sorbose by many microorganisms via "sorbose dehydrogenase" and "sorbosone dehydrogenase (SNDH)". However, only a few studies were carried out on the catalytic properties of sorbose dehydrogenase in Gluconobacter oxydans. In this study, sorbose dehydrogenase of G. oxydans WSH-004 was identified. Different from previous findings, this enzyme turned out to be a sorbose oxidase (SOX) rather than a sorbose dehydrogenase·H 2 O 2 was determined in the oxidization of L -sorbose to L -sorbosone and it also showed inhibition on the activity of SOX. Phenazine methosulfate (PMS) was the best electron acceptor of SOX and the K m of SOX for L -sorbose was 117 mM when dichlorophenolindophenol (DCIP) was used as the electron acceptor. Finally, the enzymatic catalysis of SOX and SNDH was conducted in vitro. 2-KLG could be produced from L -sorbose by SOX and SNDH with nicotinamide adenine dinucleotide phosphate (NADP+) as a cofactor. These results were useful in the reconstruction of G. oxydans to synthesize 2-KLG in a one-step fermentation process. [Display omitted] • The sorbose oxidase (SOX) of G. oxydans WSH-004 was expressed and identified. • H 2 O 2 was determined in the oxidization of L -sorbose to L -sorbosone. • H 2 O 2 showed inhibition on the activity of SOX. • Phenazine methosulfate (PMS) was the best electron acceptor of SOX. • The enzymatic catalysis of SOX and SNDH was conducted to produce 2-KLG in vitro. [ABSTRACT FROM AUTHOR]

This paper presents a fractional- N all-digital phase-locked loop (ADPLL). A 4-bit multi-delay line time-to-digital converter (MDL-TDC) using path selection technique is proposed to achieve a 4-ps resolution with 0.24-mW power consumption at 52 MS/s. A TDC offset calibration method is used to eliminate TDC metastability. An isolated constant-slope digital-to-time converter (ICS-DTC) is utilized to cancel the quantization noise (Q-noise) and achieve true-fractional delay. By tuning DTC compensation, spur and Q-noise are suppressed by 14 dB. To speed up the locking process of the ADPLL, a counter-based coarse PLL is integrated to monitor and compensate for large frequency and phase jump while consuming almost zero power. The proposed ADPLL is implemented in a 40-nm standard CMOS process, occupying a silicon area of 0.36 mm2. When TDC offset calibration is turned on, the in-band noise is suppressed by 20 dB. The measured results show 0.78-ps rms jitter and −40-dBc in-band fractional spur are achieved, corresponding to a figure of merit (FOM) of −235 dB. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • ANAMMOX could tolerate a high salinity of 500 mmol/L NaCl with NRR of 9.72 kg/(m3·d). • Unclassified Brocadiaceae was supposed to be more salt-tolerant than Ca. Kuenenia. • 160 mmol/L NaCl was the threshold value for the succession of salt-tolerant AnAOB. • Up/down regulations of PS/ζ potential in EPS were positive strategies for ANAMMOX. • 240 mmol/L NaCl was the threshold value for PS and ζ potential regulations in EPS. Abstract The application of anaerobic ammonium oxidation (ANAMMOX) process to industrial wastewater treatment usually faces the challenge of high salinity. However, most of the current ANAMMOX sludge was enriched from low-salinity water, resulting in the critical gap between the inoculum and saline wastewater. In this work, an ANAMMOX reactor fed with inoculum enriched from low-salinity water successfully adapted to saline wastewater (500 mmol/L NaCl, 2.92%) after a long-term stepwise acclimatization. The nitrogen removal rate and total nitrogen removal efficiency reached 9.72 kg·m−3·d−1 and 80.90%, respectively. However, further salinity increase to 600 mmol/L caused a collapse of reactor performance. The proportion of inorganic matters improved along with the increase of salinity, which might be attributed to the compact particles observed in the microstructure of ANAMMOX sludge. A microbial community succession occurred in response to the increase of salinity. When the salinity increased to 160 mmol/L, the dominant functional bacteria shifted from Candidatus Kuenenia to unclassified Brocadiaceae , which was supposed to be salt-tolerant. The up and down regulations of polysaccharides and ζ potential in EPS were positive strategies for salinity adaptation of ANAMMOX bacteria. However, the barrier of seawater salinity (3–5%) could not be overcome. The present work would provide a holistic view for the enrichment of salt-tolerant ANAMMOX bacteria and help in the selection of seeding sludge for the treatment of saline wastewater by ANAMMOX process. [ABSTRACT FROM AUTHOR]

This article proposes a fractional- N charge pump phase-locked loop (C P-PLL) with fast two-point modulation calibration using Duty-Cycle and Polarity Tracking technique. The proposed calibration method can perform delay and gain calibration within 15 μs, respectively. A DTC-assisted Polarity Detector is used to track and countervail the propagation delay of two modulation paths. A TDC-based Duty-Cycle Detector is used to monitor and compensate the two paths gain mismatch. By comparing the code with the threshold set in the look-up table (LUT), a quick calibration can be achieved. To maintain high out-band phase noise performance and stronger robustness, a Class-C oscillator using Capacitance Desensitization technique and Cross-Bias technique is adopted in the design. The proposed C P-PLL is implemented in a standard 110-nm CMOS technology, occupying 2.7 mm2 silicon area. The post-simulation results show the proposed calibration method can calibrate the delay/gain mismatch within 30 μs. Fast calibration mode supports calibration time within 62.5 ns. The phase noise performance is −91-dBc/Hz@100 kHz, −119-dBc/Hz@1 MHz. The entire C P-PLL dissipates 20.9-mW and achieves an RMS jitter of 6.2 ps, corresponding to a figure of merit (FOM) of −211-dB. [ABSTRACT FROM AUTHOR]

Background: Hand-foot syndrome (HFS) is a side effect of skin related to pegylated liposomal doxorubicin (PLD) application. Moderate to severe hand-foot syndrome (MSHFS) might have a serious impact on patients' quality of life and treatment. However, information on risk factors for the development of MSHFS is still limited. To analyze the risk factors for PLD-induced MSHFS in breast cancer patients and constructed a logistic regression prediction model.Methods: We conducted a retrospective analysis of breast cancer patients who were treated with a PLD regimen in the Tumor Hospital of Harbin Medical University from January 2017 to August 2019. A total of 26 factors were collected from electronic medical records. Patients were divided into MSHFS (HFS > grade 1) and NMHFS (HFS ≤ grade 1) groups according to the NCI classification. Statistical analysis of these factors and the construction of a logistic regression prediction model based on risk factors.Results: A total of 44.7% (206/461) of patients developed MSHFS. The BMI, dose intensity, and baseline Alanine aminotransferase (ALT) and Aspartate aminotransferase (AST) levels in the MSHFS group, as well as good peripheral blood circulation, excessive sweat excretion, history of gallstones, and tumour- and HER2-positive percentages, were all higher than those in the NMHFS group (P < 0.05). The model for predicting the occurrence of MSHFS was P = 1/1 + exp. (11.138-0.110*BMI-0.234*dose intensity-0.018*baseline ALT+ 0.025*baseline AST-1.225*gallstone history-0.681* peripheral blood circulation-1.073*sweat excretion-0.364*with or without tumor-0.680*HER-2). The accuracy of the model was 72.5%, AUC = 0.791, and Hosmer-Lemeshow fit test P = 0.114 > 0.05.Conclusions: Nearly half of the patients developed MSHFS. The constructed prediction model may be valuable for predicting the occurrence of MSHFS in patients. [ABSTRACT FROM AUTHOR]

The Kengdenongshe Au–Ag–Pb–Zn polymetallic deposit, a newly discovered large-scale polymetallic deposit in the southeastern section of the East Kunlun Orogen (EKO), contains an Au resource of 40 t, Ag resource of 690 t and Pb–Zn resource of 10.5 × 105 t. The ore-bearing rocks are mainly composed of laminar barite and rhyolitic tuff. In this study, LA-ICP-MS zircon U–Pb dating and whole rock major and trace elements analyses have been conducted on the ore-bearing rhyolitic tuff. LA-ICP-MS zircon U–Pb dating data show that these rhyolitic tuffs were emplaced at ca. 243.3 ± 1.6 Ma. The samples show similar features to those of S-type granites, including high contents of SiO2 (76.4–82.6 wt. %) and Al2O3 (11.0–12.7 wt. %) and relatively low concentrations of Na2O (0.35–2.43 wt. %) and CaO (0.095–0.124 wt. %), with high A/CNK (molar [Al2O3/(CaO + Na2O + K2O)]) (1.72–2.03) and K2O/Na2O ratios (1.41–17.1). Further, they exhibit depletion in HFSEs (High Field Strength Elements) and enrichment in LREEs (Light Rare Earth Element) with negative Eu anomalies (Eu/Eu* = 0.51–0.64). These geochemical characteristics indicate that the Kengdenongcuo rhyolitic tuff originated from the fluid-absent melting of a plagioclase-poor, clay-rich metapelitic source and experienced minor fractional crystallization. In combination with arc-type magmatism and contemporaneous syn-collision granitoids in the region, the Kengdenongcuo tuff formed in a continental collision setting, implying that the Bayan Har–Songpan Ganzi Terrane collided with the East Kunlun Terrane and the Paleo-Tethys Ocean was closed at the period of ~243 Ma. The Kengdenongcuo polymetallic deposit formed at about the same time. [ABSTRACT FROM AUTHOR]

Anaerobic ammonium oxidation (anammox) has been widely applied in the treatment of high-strength nitrogen wastewaters. However, few engineering practices were reported to treat low-strength nitrogen wastewaters. In this study, three types of anammox granular sludge (GS) were separately collected from the expanded granular sludge bed (EGSB) reactors treating nitrogen wastewaters at high (H-), moderate (M-) and low (L-) nitrogen loading rates (NLRs), and employed for the treatment of low-strength nitrogen wastewater in sequencing batch advanced nitrogen removal (ANR) systems. The ANR system with M-GS (namely M-ANR system) was most useful. At the initial biomass concentration of 2.43 g-VSS·L−1, cycle length of 8 h and influent total nitrogen (TN) concentration of less than 15 mg·L−1, the performance data were as follows: effluent TN of less than 1 mg·L−1, TN removal efficiency of more than 92.8%, the nitrogen removal rate (NRR) of 0.039 kg-N·m−3·d−1. The efficient performance lasted as long as 46 cycles, indicating the sustainability of the M-ANR system. The advanced microscopic analysis and metagenomic analysis were applied to reveal the successful but non-permanent treatment by the M-ANR system. The long-time lag between biomass decay and sludge activity decay provided a window period for the good performance of M-ANR system. However, the weak support of oligotrophic habitat for anaerobic ammonium oxidizing bacteria community was doomed to the degradation of anammox GS, resulting in gradual loss of their activities. A periodic addition of fresh M-GS or a periodic rejuvenation cultivation in the eutrophic habitat is necessary to achieve a permanent performance. Image 1 • Three types of anammox sludge were evaluated for advanced nitrogen removal. • The sludge in moderate nitrogen loading rate reactor was most useful and sustainable. • The mechanism was revealed for the successful while non-permanent treatment. • Two strategies were proposed to achieve a successful and permanent performance. [ABSTRACT FROM AUTHOR]

The nitrate-dependent anaerobic ferrous oxidizing (NAFO) is a newly discovered bioprocess, which is valuable to develop autotrophic denitrifying technology. In this work, the physicochemical characteristics and microbial community of the cultivated sludge (NAFO sludge) from a lab-scale reactor operating for over 200 days were investigated. A comparison between the seeding sludge and NAFO sludge was also carried out. The results showed that the NAFO sludge possessed distinctly high settleability, and the average settling velocity was 390.1 ± 161.3 m/h. The increasing particle size and density, with average values of 1469 ± 65 μm (surface area-weighed mean diameter, SMD)/2389 ± 132 μm (volumetric-weighed mean diameter, VMD) and 1580 ± 80 kg/m 3 , were revealed to the main factors causing the profile of excellent settleability. High content of iron with peak value of 87.5% (wt) was detected in NAFO sludge, which was mainly in the form of oxide compounds, such as hematite and magnetite, endowing unique morphology characteristics of NAFO sludge. After the long-term operation, a microbial succession was supposed to occur in the granular sludge, and the dominant bacterial communities in the NAFO sludge were Gamma-proteobacteria , Thermoleophilia , Clostridia and Alpha-proteobacteria classes. The present work will benefit the development of NAFO technology, and also the separation and iron-recycling processes of the NAFO sludge. [ABSTRACT FROM AUTHOR]

Highlights: [•] The addition of CO2 remarkably affected the reaction rate and product selectivity. [•] The decreased reaction rate is due to the formation of solid carbamate in the presence of CO2. [•] The yield of benzylamine was increased to >94.4% in the presence of CO2. [•] The presence of CO2 could prohibit the formation of dibenzylamine in organic solvents. [•] The acidic nature of H2O–CO2 benefited the elimination of NH3. [Copyright &y& Elsevier]

[Display omitted] • Woumbou-Colomine-Kette Granitoids were generated from Paleoproterozoic crustal rocks during two magmatic events at ca. 650–635 and ca. 620 Ma. • The Lom Belt of the Bétaré Oya gold district marked the suture zone between the Central and Southern Cameroon domains with an early rifting at ca. 784 Ma. • Lom Belt schist were metamorphosed and deformed at ca. 655–585 Ma. • Three main deformational phases at ca. 660–635 Ma (D1), 630–610 Ma (D2), and 600–580 Ma (D3) are defined in the Woumbou-Colomine-Kette and Bétaré Oya gold distrits, with D3 marked by the gold mineralization. The Bétaré Oya and Woumbou–Colomine–Kette gold districts, located in the East Metallogenic Province of Cameroon, are characterized by a complex Neoproterozoic history of metamorphism, polyphase deformation, and widespread crustal anatexis and magmatism. Controversy exists on the timing of the metamorphic and magmatic events, particularly within the area of the Lom Belt, and accurate absolute ages and even geodynamic chronology pertaining to the tectono-magmatism are yet to be well constrained. New LA-ICP-MS U–Pb zircon ages, Lu-Hf isotope data, and whole-rock geochemistry of granitoids and metavolcanic-metasedimentary rocks from the Woumbou–Colomine–Kette and Bétaré Oya districts better constrain the tectonic evolution of eastern Cameroon. The U–Pb age data of 646.5 ± 2.0 Ma, 643.7 ± 1.8 Ma, 641.3 ± 4.4 Ma, 641.4 ± 3.5 Ma, and 620.9 ± 2.6 Ma revealed that the granitoids from the Woumbou–Colomine–Kette district were emplaced during two main magmatic events at ca. 650–635 Ma and ca. 620 Ma. The zircon Hf(t) values between −13.80 and −6.20 with Hf TDM model ages of 1.9–2.4 Ga, coupled with geochemical signatures show that granitoids were generated by partial melting of Paleoproterozoic supracrustal metasedimentary units and meta-igneous rocks during subduction and orogenic convergence. Metamorphic zircons from the actinolite-chlorite schist of the Lom Belt gave ages between ca. 655 and 585 Ma, implying that the metavolcanic-metasedimentary rocks of the belt were deposited prior to 655 Ma, then metamorphosed and deformed between ca. 655 and 585 Ma. Two age peaks of detrital zircons were measured at ca. 1035 Ma and ca. 784 Ma with the εHf (t) values of –14.60 and –18.37 and +2.97 and +8.60, respectively. These data, coupled with those from previous studies, suggest that the Lom Belt may represent a suture zone between the Central and Southern Cameroon domains with an early rifting at ca. 784 Ma. In general, our U–Pb ages indicate compressional to transpressional deformational phases in the two districts at ca. 660–635 Ma (D1), 630–610 Ma (D2), and 600–580 Ma (D3). The latter D3 transpressional event was also associated with the formation of the widespread occurrences of orogenic gold, although the precise timing of gold deposition needs to be constrained. [ABSTRACT FROM AUTHOR]

This paper presents an accurate ISF-based phase noise analysis method for LC/Ring oscillators. The proposed method can simultaneously quantify the effect of flicker noise and thermal noise on phase noise. The impulse sensitivity function (ISF) tool is used to evaluate the effect of flicker noise sources. An equivalent thermal noise resistor is utilized to assess the thermal noise contribution and simplify the analysis process. Based on the proposed method, the phase noise performance of a voltage-controlled oscillator (VCO) with source damping resistors is discussed. Simulated in 180-nm TSMC and 110-nm HHGRACE CMOS processes, the accuracy of the proposed method is verified. The predicted phase noise performance is consistent with the simulation results in 1/ f 3 and 1/ f 2 region, achieving 1-dB accuracy in diverse oscillator topologies. [ABSTRACT FROM AUTHOR]

Anammox process has been widely applied in the wastewater nitrogen removal for its high rate and low cost. However, few researches reported the process potential in treating low-strength nitrogen wastewater. In this study, a sequencing batch reactor (SBR) was taken to explore the feasibility of low-strength nitrogen wastewater treatment by anammox process in theory and practice. The practical operation indicated that the effluent with satisfactory quality (1.90 ± 0.70 mg-TN·L−1) could be achieved, when the SBR was fed with low-strength nitrogen influent (6.20 ± 0.45 mg-NH 4 +-N·L−1 and 7.96 ± 0.59 mg-NO 2 --N·L−1). The hydraulic retention time (HRT), nitrogen removal efficiency, nitrogen removal rate (NRR) and hydraulic loading rate of SBR were 5.42 h, 86.5%, 0.054 kg-N·m−3·d−1 and 4.43 m3·m−3·d−1 during the 79-day operation, respectively. The theoretical analysis revealed the potential of anammox SBR. When SBR is stably operated, the maximum NRR would be 0.062 kg-N·m−3·d−1 if the effluent nitrogen was required to be as low as 3 mg·L−1. The NRR value is feasible for engineering. However, considering the lower specific substrates utilization rate in practice, the maximum stable NRR was calibrated and found inefficient afterwards. In order to improve the potential of anammox process, the reactors without back mixing and with periodic bioaugmentation should be taken in priority for the engineering applications. In particular, the bioaugmentation frequency and single addition amount were calculated as 7 d and 0.3 g-VSS·L−1, respectively. The results may provide guidance for the development of high-efficient and stable nitrogen removal process under low-strength condition. • Potential of anammox for high-efficiency nitrogen removal was analyzed. • High-quality effluent was achieved by anammox-SBR with extremely low-strength inflow. • Stable efficiency of SBR can be improved by optimizing reactor type and operation. [ABSTRACT FROM AUTHOR]