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Biomass chemical looping gasification (BCLG) is a promising technology for producing high-quality syngas. In this study, the BCLG of corn cob using inexpensive industrial waste red mud (RM) as an oxygen carrier was carried out in a fixed bed reactor, focusing on enhancing syngas quality and tar reduction. The gasification performance of BCLG was investigated under different conditions, including O/C ratio, steam flow rate, and reaction temperature. RM improved gas yield and quality with a maximum H2/CO ratio of 2.39 while reducing tar yield by 38.75%. High temperature led to the polymerization of polyaromatic hydrocarbons (PAHs) in tar, but steam effectively reduced PAHs by 33.25% via the tar homogeneous conversion. The degree of tar cracking and conversion to gases in the presence of steam was more than the thermal decomposition in the pure N2 atmosphere. Additionally, metal oxides within RM participated in reactions with steam. The limitation of intensive reduction of RM through iron-steam reactions enhanced H2 yield and prevented RM sintering. XRD analyses revealed the evolution of iron compounds in RM during BCLG: Fe2O3—Fe3O4—FeO/Fe—Fe3O4. Under the optimal conditions of BCLG, the carbon conversion efficiency, gasification efficiency, and gas yield reached 70.74%, 92.95%, and 1.24 m3/kg, respectively. Meanwhile, the H2/CO ratio reached 1.82 while the tar yield was reduced to 0.196 g/gfuel. This study highlighted the potential of using RM as an effective oxygen carrier in the BCLG, which would contribute to the advancement of sustainable biomass gasification. [ABSTRACT FROM AUTHOR]

Aims: To investigate the impact of baseline characteristics on the efficacy of once‐weekly subcutaneous semaglutide 0.5 and 1.0 mg in participants with type 2 diabetes (T2D) from the SUSTAIN China trial. Methods: In this post hoc analysis, data for semaglutide 0.5 and 1.0 mg versus sitagliptin 100 mg were analysed in the total (n = 868) and Chinese‐only (n = 605) populations. Changes from baseline to end of treatment (EOT) in glycated haemoglobin (HbA1c) and body weight were analysed by baseline age, sex, body mass index, HbA1c, diabetes duration, and homeostatic model assessment of β‐cell function (HOMA‐β) tertile. Proportions of participants achieving HbA1c <7.0% (53 mmol/mol) by baseline HbA1c, change from baseline to EOT in standard deviation of seven‐point self‐monitored plasma glucose (SMPG), derived time‐in‐range (dTIR) of seven‐point SMPG at Week 30, and HOMA‐β ratio to baseline at Week 30 were assessed for both populations. Results: In both populations the efficacy of once‐weekly subcutaneous semaglutide 0.5 and 1.0 mg versus sitagliptin was not significantly affected by most of the baseline characteristics studied. The proportion of participants achieving the target HbA1c <7% was not affected by baseline HbA1c (pinteraction > 0.05). SMPG fluctuation and dTIR indicated less glucose variability in participants treated with semaglutide 0.5 and 1.0 mg versus sitagliptin, and the HOMA‐β ratios to baseline at EOT were greater with semaglutide 0.5 and 1.0 mg versus sitagliptin (p < 0.05). Conclusions: These results support the effectiveness of once‐weekly subcutaneous semaglutide 0.5 and 1.0 mg across a broad range of baseline characteristics, in participants with T2D from SUSTAIN China. [ABSTRACT FROM AUTHOR]

Aim: Efficient primary prevention of diabetic kidney disease (DKD) is currently lacking. The identification of people at high DKD risk and timely intervention are key to preventing DKD. Therefore, a model to classify people according to their risk for developing DKD was developed previously and used in the current analysis to assess the effect of semaglutide versus placebo on primary DKD prevention. Methods: Participants with type 2 diabetes from the randomized, double‐blind, placebo‐controlled SUSTAIN 6 trial without DKD at baseline who received 0.5/1.0 mg semaglutide or placebo were grouped by baseline DKD risk, calculated using a validated model. The main post hoc outcome was the effect of semaglutide versus placebo on the proportion of participants who developed DKD [urinary albumin/creatinine ratio (UACR) ≥30 mg/g and/or estimated glomerular filtration rate <60 mL/min/1.73 m2]. Additional post hoc outcomes included changes in DKD risk score, UACR and estimated glomerular filtration rate over time. Results: Of the total 1139 participants included in the analysis, 28.7% developed DKD; more participants with a high DKD risk (952/1139) developed DKD. Semaglutide significantly reduced the risk of developing DKD in both the total [odds ratio 0.56 (95% confidence interval: 0.42; 0.74; p < 0.0001)], and high DKD risk population [odds ratio 0.51 (95% confidence interval: 0.38; 0.69; p < 0.0001)] and significantly delayed DKD development versus placebo. The beneficial effects of semaglutide were largely driven by UACR changes. The number needed to treat for semaglutide in the high DKD risk population was 7. Conclusions: This post hoc study indicates that semaglutide may have beneficial effects on primary DKD prevention in people with T2D. [ABSTRACT FROM AUTHOR]

In order to achieve the targets of Paris Agreement and carbon neutrality, developing CO2 negative emission technologies such as biomass energy with carbon capture and storage (BECCS) is of great significance. Biomass integrated calcium looping gasification combined cycle (CL-BIGCC) with in situ carbon capture during gasification is an attractive option among various options. In this work, Aspen Plus software was used to establish the thermodynamic model of CL-BIGCC system based on "gasification-combustion" dual reactors and traditional biomass integrated gasification combined cycle (BIGCC) system with carbon capture. The reliability of both models was first verified, and then, energy analysis and exergy analysis were used to examine the loss of key units and overall performance for the two systems. The results showed that comparing with the BIGCC system, the CL-BIGCC system significantly promoted the overall exergy efficiency. The largest two sources of exergy loss for the CL-BIGCC system were the "gasification-combustion" dual reactors and the gas turbine. Under a typical case with CO2 capture efficiency larger than 90%, the energy efficiency, exergy efficiency, and CO2 specific emission of the CL-BIGCC system were 42.42%, 38.77%, and 58.45 g kWh−1, respectively. Moreover, the effects of key parameters such as gasification temperature, steam to carbon molar ratio, and gas turbine compression ratio on the exergy loss and overall performance of the CL-BIGCC system were discussed. Finally, the calculated results of a typical case of CL-BIGCC system were compared with those of other reported BIGCC systems with carbon capture in literature, which verified the advantages of CL-BIGCC system over other BIGCC systems with negative carbon emission. [ABSTRACT FROM AUTHOR]

Aims: To identify perceptions, attitudes, behaviours and barriers to effective obesity care among people living with obesity (PLwO) and healthcare professionals (HCPs) across mainland China. Materials and Methods: ACTION‐China (ClinicalTrials.gov: NCT05428501) was a cross‐sectional, observational, descriptive, online survey‐based study of 7000 PLwO and 1000 HCPs (conducted between August and November 2022). Results: The majority of PLwO (76.8% [5374/7000]) and HCPs (94.6% [946/1000]) agreed that obesity is a chronic disease. Only 40.8% of PLwO (2853/7000) had discussed their weight or talked about losing weight with an HCP in the past 5 years. The most frequent reason given by PLwO for not discussing weight management with an HCP was believing it was their responsibility to manage their weight (34.7% [2430/7000]), whereas the most frequent reason HCPs gave for not discussing obesity with their patients with obesity was having more important health issues to discuss (72.1% [721/1000]). A smaller proportion of PLwO (19.1%) than HCPs (53.6%) felt that weight management discussions with an HCP would be very or extremely helpful for the patient, and 30.7% of PLwO experienced negative feelings after their most recent discussion. Overall, 34.8% (2438/7000) of PLwO had been diagnosed with obesity by an HCP, while 30.0% (2101/7000) of PLwO did not recognize that they had obesity. Conclusions: This large, national survey conducted among PLwO and HCPs highlights key barriers to effective obesity care in China, including underestimation of weight status by PLwO and the need for increased communication between HCPs and PLwO regarding weight management. [ABSTRACT FROM AUTHOR]

Background: Despite its relevance for healthcare settings, social and behavioral risk screening is not systematically performed by clinicians or healthcare systems. Objective: To address clinician concerns, such as social and behavioral risk screening disrupting the clinician-patient relationship and lack of resources to respond, we interviewed primary care patients at an academic medical center regarding their perceptions and preferences on social and behavioral risk screening. Participants: Between September and December 2020, we recruited a convenience sample of 14 English-speaking primary care patients 18 years + from three clinics affiliated with an academic medical center. Approach: Using a semi-structured interview guide, we asked about the importance of social and behavioral risk screening, whether or not and how to share social and behavioral risk factors, and how social and behavioral risk factors are addressed. We used a multi-step analytic process to identify the range and commonality of participants' responses thematically. Key Results: Participants recognized that social and behavioral risk factor domains were relevant to primary care and important for treating the patient as a whole person. Participants preferred a conversation regarding social and behavioral risk factor with their primary care providers (PCPs), and suggested that, if surveys are used, they be followed with an open-ended, in-person discussion. Participants also suggested framing the discussion as something that is done routinely with all patients so that patients do not feel judged. Participants felt comfortable sharing social and behavioral risk factors when they trusted their PCPs, and felt that discussing social and behavioral risk factors with their PCPs built trust. Participants recognized that resources exist outside of the clinic, and suggested that PCPs distribute lists of relevant community resources to patients. Conclusion: In our study of primary care patients on perceptions and preferences about screening and addressing social and behavioral risk factors, we found that patients were willing to share social and behavioral risk factors with their PCP, preferred an in-person discussions with or without a survey, and wanted a list of community resources to address their needs. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the prevalence of overweight/obesity and associated complications from a large, cross‐sectional, nationwide database in China. Materials and Methods: Data were obtained from 519 Meinian health check‐up centres across 243 cities. Eligible participants were aged ≥18 years, with a routine check‐up in 2019 (N = 21 771 683) and complete height, weight, sex and region data. The unadjusted prevalence rates of overweight/obesity were calculated by age, sex and region. In addition, the nationwide prevalence rates of overweight and obesity were standardized according to the 2010 China census by age group and sex. The prevalence of obesity‐related complications by body mass index (BMI) groups was calculated using logistic regression. Results: There were 15 770 094 eligible participants (median age 40 years; mean BMI 24.1 kg/m2; 52.8% male). By Chinese BMI classification, 34.8% were overweight and 14.1% were obese. Overweight and obesity were more prevalent in male than female participants (standardized: overweight 40.2% vs. 27.4%; obesity 17.6% vs. 9.6%, respectively). The prevalence of assessed complications was higher in participants with overweight/obesity versus those with normal BMI (P < 0.001 for trends). The most prevalent complications in participants with overweight/obesity were fatty liver disease, prediabetes, dyslipidaemia and hypertension. The number of complications increased with higher BMI. Conclusions: Overweight/obesity and related complications are highly prevalent in this population. These data may better inform management and prevention public health strategies in China. [ABSTRACT FROM AUTHOR]

Electrocatalytic conversion of soluble lithium polysulfides (LiPSs) has been proposed as a crucial approach to address the drawbacks of lithium–sulfur (Li–S) batteries. However, it still remains a great challenge to realize the integration of strong adsorption and high catalytic activity within a single electrocatalyst. Herein, we conceptually demonstrate the rational design and synthesis of a crystalline Bi2Se3 and amorphous BiOx heterostructure (denoted as c-Bi2Se3/a-BiOx) as an advanced separator modifier for Li–S batteries. In such a heterostructure, a-BiOx has strong chemical adsorption ability toward LiPSs and c-Bi2Se3 possesses high catalytic activity for LiPS conversion. Meanwhile, the heterointerface enables rapid diffusion of LiPSs from a-BiOx to c-Bi2Se3, thus synergistically contributing to the highly efficient adsorption–diffusion–conversion process of LiPSs. Benefiting from these advantages, Li–S batteries using a c-Bi2Se3/a-BiOx heterostructure modified separator exhibit excellent electrochemical performance in terms of high discharge capacity (1517.9 mA h g−1 at 0.1C), outstanding rate capacity (873.1 mA h g−1 at 4C) and long-term cycling stability with a low capacity decay rate of 0.041% per cycle over 1000 cycles at 1C. Furthermore, a remarkable areal capacity of 3.85 mA h cm−2 can be achieved at a high sulfur loading of 5.5 mg cm−2. This work provides valuable insight into the development of crystalline/amorphous heterostructures as robust and highly active electrocatalysts for high-performance Li–S batteries. [ABSTRACT FROM AUTHOR]

The two-level voltage source inverter fed dual three-phase motor (DTPM) induces the high-frequency common-mode voltage (CMV) and generates the unwanted adverse effects. As one of the effective common-mode suppression methods, the conventional CMV elimination (CMVE) pulsewidth modulation (PWM) schemes are generally based on the voltage-balance mode for DTPM systems which suffer from the parameter asymmetry induced phase current imbalance. This article proposes two current-balance mode unified CMVE PWM schemes which has no restriction on the reference voltages and angle displacement between the two sets of three-phase windings. Thus, the proposed methods can be utilized in different types of DTPMs with different angle displacements between the two winding sets, and the CMVE effect can be retained both in the conditions of symmetrical and asymmetrical system parameters which is more practical than conventional CMVE schemes in real application. The function and performance of the proposal is proved by simulations and experiments. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries are growing in popularity by virtue of their high energy density, low cost and environmental friendliness. However, the commercialization of Li–S batteries is severely hindered by low sulfur utilization, sluggish sulfur redox chemistry, and the severe shuttle effect of lithium polysulfides (LiPSs). In this work, a hierarchical composite composed of VN and nitrogen-doped carbon nanotubes encapsulated with Co3ZnC nanoparticles (denoted as VN/Co3ZnC@NCNTs) is conceptually designed through a space-confined melamine-assisted nitridation strategy. As a multifunctional integrated sulfur host, the hierarchical VN/Co3ZnC@NCNT composite has a variety of advantages including high electrical conductivity, good physical confinement and chemical adsorption to LiPSs, and superior electrocatalytic activity, which can effectively facilitate the immobilization–diffusion–conversion process of soluble LiPSs. As a result, the Li–S batteries based on the VN/Co3ZnC@NCNT host exhibit a high discharge capacity of 1399.4 mA h g−1 at 0.1C, as well as excellent rate capability (566.4 mA h g−1 at 5C) and long-term cycling stability (557.6 mA h g−1 at 1C after 500 cycles with a low decay rate of 0.064% per cycle). More encouragingly, even at a high sulfur loading of 4.5 mg cm−2, the S@VN/Co3ZnC@NCNT cathode still delivers a high reversible capacity of 639.2 mA h g−1 at 0.2C after 100 cycles. Furthermore, experimental results and theoretical calculations demonstrate that strengthening adsorption is not responsible for the improvement of catalytic activity. This work could provide a novel insight into the rational development of multifunctional integrated sulfur host materials for high-performance Li–S batteries. [ABSTRACT FROM AUTHOR]

Leakage current issues are worthy of attention for nonisolated grid-connected systems. This article introduces the method of eliminating common-mode (CM) voltage and reducing the leakage current based on modulation, and analyzes the correlation between actual effects of the method and the flying capacitor (FC) voltage balance in three-phase three-level FC grid-connected inverter. The proposed carrier-based modulation can balance the FC voltage by changing the transmission sequences of pulses and theoretically achieve zero CM voltage. In order to deal with the low frequency fluctuation and bias voltage of FC caused by asymmetry of actual hardware, the control method is introduced, which controls FC voltage by changing the action times’ distribution of switches, while still eliminating the CM voltage. Simulation and experimental results are provided to validate that the proposed method can control FC voltage and achieve good performance in suppressions of CM voltage, leakage, current and CM electromagnetic interference noise. [ABSTRACT FROM AUTHOR]

The increased phase number of multiphase systems enables us to exploit more degrees of freedom, such as the shape of phase carriers in pulsewidth modulation (PWM). The sawtooth carrier-based PWM (SCPWM) techniques are proposed in this article to reduce common-mode voltage (CMV) in both the peak-to-peak amplitude and the changing frequency, and it can be easily extended to symmetrical multiphase two-level inverters with any odd phase number. Theoretical analysis reveals that the switching between mirror-symmetrical carriers within one phase narrows the range of the sum of switching states in all phases, which leads to the reduction of CMV amplitude. Meanwhile, the overlapping of sawtooth carriers’ straight edges among different phases slows down the change of the sum of switching states, which results in the decrease of CMV changing frequency. Moreover, the effects of voltage harmonics injection and switches’ dead-time settings on the CMV reduction performance under the proposed SCPWM techniques are investigated. Finally, the experiment results in a five-phase induction machine and multiphase RL loads verify the improved CMV performance and the extensibility of the proposed SCPWM methods. [ABSTRACT FROM AUTHOR]

Spread-spectrum modulation strategy is recognized as an effective solution to reduce conducted electromagnetic interference (EMI). This article proposes a family of spread-spectrum modulation strategies that can effectively reduce the conducted EMI for power electronics converters. The introduced modulation strategies eliminate the noise spikes in conducted EMI spectrum, reducing the harsh requirements for designing EMI filters. The proposed spread-spectrum methods are based on the distribution characteristic of switching frequency, which determine the waveform function of switching frequency. In addition, the design principles take reduced switching losses and fixed variation range of switching frequency into consideration. The differential equation that makes the switching frequency subject to arbitrary statistical distribution is derived in detail together with the corresponding solutions. Three typical statistical distributions represented by uniform distribution, exponential distribution and normal distribution are performed. Relevant experiments have verified that the proposed spread-spectrum modulation schemes can reduce the conducted EMI about 20 dB. Finally, several other typical spread-spectrum modulation schemes such as random pulsewidth modulation (PWM), periodic PWM, and programmed PWM are implemented in converters for comprehensive comparison to evaluate the proposed spread-spectrum modulation schemes. [ABSTRACT FROM AUTHOR]

It is necessary to suppress the emission level of conducted electromagnetic interference (EMI) for the power electronics converters, and the variable switching frequency pulsewidth modulation (VSFPWM) is an alternative approach to reduce conducted EMI without adding bulky passive components. However, the experimental results indicate that many obvious EMI spikes in spectrum remain so that the conducted EMI reduction for VSFPWM is limited. In order to eliminate the EMI spikes in spectrum, this article first investigates the cause of the EMI spikes for VSFPWM, and the analysis results show that the nonuniform distribution of switching frequency is the primary reason. Then, a novel PWM strategy called uniform distribution PWM (UDPWM) is proposed to eliminate the EMI spikes and to further reduce conducted EMI. The design of a UDPWM is based on the uniform distribution of switching frequency and the principle of less switching loss. Moreover, the analytical formula of switching frequency is also deduced in detail, which adopts fixed variation range of switching frequency whatever the modulation index is. Finally, the experiments are carried out to validate the effectiveness of the UDPWM in reducing conducted EMI and switching loss. The UDPWM can approximately reduce conducted EMI by 20 dB compared with the conventional constant switching frequency PWM, and all obvious spikes in the spectrum are eliminated compared with VSFPWM. [ABSTRACT FROM AUTHOR]

Determination of high-frequency circulating current is important for coupled inductor design of paralleled voltage source inverters (VSIs). A time-domain model describing the circulating current of coupled inductor within a switching period is presented in this article. Using this model, the peak or rms values of circulating current can be calculated for different pulsewidth modulation (PWM) methods. Both the conventional 180° interleaved PWM and zero-common-mode voltage PWM algorithms are studied here. Considering the saturation nature of the magnetic cores in determining the effective inductance of coupled inductors, the variable switching frequency PWM (VSFPWM) is proposed to better utilize the coupled inductor's saturation limit, which is determined by high-frequency circulating current peak value. With the proposed strategy, both switching losses and electromagnetic interference are improved with respect to the constant switching frequency PWM. Moreover, the detailed power losses analysis of paralleled VSIs has been presented and the dynamic performance of the proposed VSFPWM has been well investigated. Finally, the proposed method has been extended to the system with 2N paralleled inverters. Detailed simulation and experimental results are provided to validate the proposed method. [ABSTRACT FROM AUTHOR]

Summary: In a Chinese population from both urban and rural areas, weight loss of ≥ 5 kg from early adulthood to midlife was associated with a higher risk of hip fracture and lower BMD in later life. Introduction: This study investigates the association of the long-term weight loss from young adulthood through the middle ages with the subsequent 10-year risk of hospitalized fracture and calcaneus bone mineral density (BMD). Methods: China Kadoorie Biobank (CKB) was established during 2004–2008 in ten areas across China. Weight at age 25 years was self-reported at baseline, and weight at baseline and resurvey was measured by the calibrated equipment. Outcomes were hospitalized fracture during follow-up and calcaneus BMD measured at resurvey. Analysis for fracture risk included 411,812 participants who were free of fracture in the last 5 years before baseline, cancer, or stroke at any time before baseline. Analysis for BMD included 21,453 participants who participated in the resurvey of 2013–2014 with the same exclusion criteria as above. Results: The mean age was 50.8 at baseline and 58.4 at resurvey. Median weight change from age 25 to baseline was 4.4 kg, with 20.7% losing weight and 58.5% gaining weight. During a median follow-up of 10.1 years, we documented 13,065 cases of first diagnosed fracture hospitalizations, including 1222 hip fracture. Compared with participants whose weight was stable (± 2.4 kg), the adjusted hazard ratios (95% CIs) for those with weight loss of ≥ 5.0 kg from age 25 to baseline was 1.39 (1.17 to 1.66) for hip fracture. Weight loss was not associated with fracture risk at other sites. Those with weight loss from age 25 to resurvey had the lowest BMD measures, with β (95% CIs) of − 4.52 (− 5.08 to − 3.96) for broadband ultrasound attenuation (BUA), − 4.83 (− 6.98, − 2.67) for speed of sound (SOS), and − 4.36 (− 5.22, − 3.49) for stiffness index (SI). Conclusions: Weight loss from early adulthood to midlife was associated with a higher risk of hip fracture and lower BMD in later life. [ABSTRACT FROM AUTHOR]

The voltage-source inverter with pulsewidth modulation (PWM) is widely used in motor drive applications owing to the technical maturity and simplicity. However, the inverter operating in the discrete and impulse state generates the high-frequency common-mode voltage (CMV) in the neutral point terminal of stator winding, which induces the negative effects. This article proposes a CMV elimination modulation scheme for the dual two-level inverter-fed asymmetrical six-phase permanent magnet synchronous motor, which has two sets of three-phase windings spatially shifted by 30° electrical degrees. The modulation algorithm shifts the PWM signals with the designed end-to-end cyclic sequence, which can retain the zero-voltage vectors for each sub-CMV of dual three-phase windings and theoretically eliminate the total CMV for the motor drive system. The validation of the proposal is verified by simulations and experiments. [ABSTRACT FROM AUTHOR]

This paper introduces a novel pulsewidth modulation (PWM) scheme for an open-winding permanent magnet synchronous machine (OW-PMSM) driven by dual two-level three-phase inverter with common dc bus, which can effectively deal with the inherent zero-sequence current (ZSC) problem. Based on the conventional symmetrical unipolar double-frequency sinusoidal PWM scheme with an appropriate phase shift, the common mode voltage (CMV) of two inverters remains same and cancel out each other to eliminate the modulated zero-sequence voltage (ZSV) disturbance source. In this case, the double-frequency effect can be retained to reduce the ac side current ripple and suppress both corresponding motor vibration and acoustic noise, which is advantageous to improve the synthetic performance of motor. The dc-bus voltage utilization of the novel PWM scheme is proved to reach the same maximum value comparing to the conventional modulated ZSV elimination scheme. Meanwhile, a zero-sequence controller is designed to suppress ZSC by further adjusting the two CMVs to counteract other zero-sequence disturbance sources. To verify the analysis, the proposed PWM technique associated with the control method is implemented in an OW-PMSM experimental setup to validate the superiority of the proposed method. [ABSTRACT FROM AUTHOR]

Current experimental and epidemiological studies provide inconsistent evidence toward the association between tea consumption and cancer incidence. We investigated whether tea consumption was associated with the incidence of all cancers and six leading types of cancer (lung cancer, stomach cancer, colorectal cancer, liver cancer, female breast cancer and cervix uteri cancer) among 455,981 participants aged 30–79 years in the prospective cohort China Kadoorie Biobank. Tea consumption was assessed at baseline (2004–2008) with an interviewer-administered questionnaire. Cancer cases were identified by linkage to the national health insurance system. Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). In the present population, daily tea consumers were more likely to be current smokers and daily alcohol consumers. 22,652 incident cancers occurred during 10.1 years follow-up (5.04 cases/1000 person-years). When we restricted analyses to non-smokers and non-excessive alcohol consumers to minimize confounding, tea consumption was not associated with all cancers (daily consumers who added tea leaves > 4.0 g/day vs. less-than-weekly consumers: HR, 1.03; 95%CI, 0.93–1.13), lung cancer (HR, 1.08; CI, 0.84–1.40), colorectal cancer (HR, 1.08; CI, 0.81–1.45) and liver cancer (HR, 1.08; CI, 0.75–1.55), yet might be associated with increased risk of stomach cancer (HR, 1.46; CI, 1.07–1.99). In both less-than-daily and daily tea consumers, all cancer risk increased with the amount of tobacco smoked or alcohol consumed. Our findings suggest tea consumption may not provide preventive effect against cancer incidence. [ABSTRACT FROM AUTHOR]

In a motor drive system, the inverter working in discrete and impulse states generates a common-mode voltage (CMV) at the terminal of the stator winding neutral point. The high-frequency CMV can induce a leakage current and a common-mode (CM) electromagnetic interference (EMI), which are potential threats to personal safety and system stability. The conventional single three-phase inverter is found to be powerless in eliminating the CMV, while the two paralleled inverters can effectively eliminate the CMV theoretically, but the three coupled inductors (CIs) should be added to the motor drive system which reduces the power density and efficiency of the system. A novel method, which associates a specially designed dual-segment three-phase motor with the CMV elimination modulation algorithm, can be utilized to cancel the extra CIs without degrading the function of the leakage current and the CM EMI suppression. The design of the dual-segment three-phase permanent magnet synchronous machine is introduced, with identical back electromotive forces for two groups of windings but with little magnetic coupling between them. Simulation and experimental results are provided to verify the validity of the proposed method in CM-related reduction and CI cancellation. Compared with the zero-CM pulsewidth modulation for paralleled inverters proposed in a previous work, the proposed dual-segment three-phase motor drive can achieve a better power density by removing the CIs. [ABSTRACT FROM AUTHOR]

Chemical looping gasification (CLG) is an efficient and economical solution to convert organic solid waste into hydrogen-rich syngas for fossil fuel substitution. In this work, chemical looping co-gasification (CLCG) of sewage sludge (SS) and bituminous coal (BC) with hematite as the oxygen carrier was examined in a fluidized bed. The SS-BC CLCG exhibited significant fuel synergy compared to the SS/BC CLG, enhancing the gasification efficiency and carbon conversion. The effects of several key operating variables including SS blending ratio, reaction temperature, and steam mass flow rate on CLCG performance were investigated and the optimum conditions were 20 wt% SS, 900 °C with a steam mass flow rate of 0.6 g/min. Moreover, a cyclic CLCG test was also performed to evaluate the stability of oxygen carrier reactivity and gasification performance at optimized operating conditions. After 13 cycles, the hematite still presented good or even improved performance with gasification efficiency of 80.94 %, syngas yield of 2.10 Nm3/kg fuel , and carbon conversion of 93.73 %. The improved porous structure and the ash catalyst effect were responsible for the promoted performance of the natural hematite oxygen carrier with increasing cycles. It is concluded that CLG is a promising technology to provide high-quality hydrogen-rich syngas from SS and BC mixtures. [Display omitted] • Chemical looping co-gasification of coal and sewage sludge was studied in fluidized bed. • Synergy between sewage sludge and coal were evaluated for H 2 rich syngas production. • Effects of operating variables were examined. • Hematite presented good or even improved performance during cyclic tests. [ABSTRACT FROM AUTHOR]

In voltage-source inverters (VSIs), dead time is used to prevent shoot-through over switching devices. However, the existence of the dead time will distort the output phase current, which degrades the performance of the inverter as well as influences the common-mode voltage (CMV), particularly in CMV elimination relevant modulation schemes, such as zero-common-mode (CM) pulsewidth modulation (PWM)-based paralleled inverters. In the light of the situation that the normal sampling-based dead-time compensation (DTC) methods are often disturbed by the current ripple, this paper introduces a novel DTC method for the VSI, which can mitigate the impact of the current ripple and improve the accuracy of DTC. The proposed method deduces the real-time current ripple, which can reconstruct the actual trajectory of phase-leg currents, and the peak values corresponding to rising and falling edges for PWM signals can be predicted. In this way, DTC can be implemented based on the direction of relevant instantaneous switching currents and finally improves the accuracy. Especially, the current-ripple-prediction-based DTC can help to improve the CMV distortion caused by the dead time for paralleled inverters with zero-CM PWM. Simulation and experimental results are provided to validate that the proposed method can be applied to different topologies and modulation schemes with good performance. [ABSTRACT FROM AUTHOR]

Paralleled inverters are not only a suitable approach to increase the power capacity, but also have the capability of common mode voltage (CMV) reduction, or even elimination. The original zero CMV modulation scheme for paralleled inverters suffers from the current jump problem in phase-leg currents. This current jump phenomenon amplifies the peak values of differential-mode circulating current (DMCC) and zero-sequence circulating current (ZSCC), which is adverse for the design of coupled inductor and common-mode inductor. This paper introduces the modified modulation scheme, which can keep volt-seconds balance in whole fundamental period and mitigate the current jump in phase-leg currents. In addition, the reduction effect of the DMCC and ZSCC can be achieved. To verify the analysis, both the simulation and experimental results are presented, which validates the proposed methods and show that they are beneficial for DMCC and ZSCC reduction. [ABSTRACT FROM AUTHOR]

This paper introduces series work of common-mode (CM) voltage reduction for the paralleled inverters. The paralleled inverters’ phase-legs are connected through coupling inductors and the combined three-phase currents are provided to the load. Interleaving is an approach to reduce the CM voltage for the paralleled inverters but it cannot eliminate CM voltage. A novel pulse-width-modulation (PWM) method for paralleled inverters which can theoretically achieve zero CM voltage is developed. Considering the basic voltage vectors in each inverter, novel paralleled voltage vectors which have zero CM voltage are proposed to combine the reference voltage vector. The action time's distribution and voltage vectors’ sending sequence for each inverter are also introduced. The proposed PWM method can make sure the voltage of the two inverters are balanced in each switching cycle and limits the circulating current through small coupling inductors. Similar to interleaving space vector PWM, the proposed zero CM PWM also has the ability to reduce the output current ripple and electromagnetic interference (EMI). Simulation and experimental results are provided to show the advantage of paralleled inverters in CM voltage reduction and validate the proposed method has good performance to reduce CM current and CM EMI noise. [ABSTRACT FROM PUBLISHER]

This study is for model predictive pulse‐width modulation (PWM) for power electronics converters as AC motor drives. Compared with conventional PWM, model predictive PWM (MPP) employs the prediction model of PWM effect, and utilises the pulse arrangement freedoms to improve the performance of switching losses, current ripple and electromagnetic interference for the converter system. This study contains five parts including introduction, current ripple prediction method, variable switching frequency PWM, MPP for multi‐level inverters and conclusions. The methods introduced in this study have been and can be applied in traction and industry motor drives. [ABSTRACT FROM AUTHOR]