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Objective: There is concern that the coronavirus disease (COVID-19) vaccine may trigger or worsen autoimmune diseases. The objective of this study was to determine the impacts of COVID-19 vaccination on symptom severity in patients with myasthenia gravis (MG). Methods: A total of 106 enrolled patients with MG who were vaccinated against COVID-19 were followed up, and a questionnaire was used to document in detail the exacerbation of muscle weakness after vaccination and all other uncomfortable reactions after vaccination. Demographic, clinical characteristics, medication, and vaccination data were collected by follow-up interview. The main observation outcome was whether the MG symptoms of patients were exacerbated. The definition of exacerbation is according to the subjective feeling of the patient or a 2-point increase in daily life myasthenia gravis activity score relative to before vaccination, within 30 days after vaccination. Results: Of 106 enrolled patients [median age (SD) 41.0 years, 38 (35.8%) men, 53 (50.0%) with generalized MG, 74 (69.8%) positive for acetylcholine receptor antibody, and 21 (19.8%) with accompanying thymoma], muscle weakness symptoms were stable in 102 (96.2%) patients before vaccine inoculation. Muscle weakness worsened in 10 (9.4%) people after vaccination, of which 8 patients reported slight symptom worsening that resolved quickly (within a few days). Two (1.9%) of patients showed serious symptom aggravation that required hospitalization. Conclusion: Our results suggest that inactivated virus vaccines against COVID-19 may be safe for patients with MG whose condition is stable. Patients with generalized MG may be more likely to develop increased muscle weakness after vaccination. [ABSTRACT FROM AUTHOR]

Ni 25 Ti 25 Hf 25 Cu 25 medium entropy shape memory alloy (MESMA) exhibit reversible B2↔B19′ martensitic transformation. Martensitic morphology is represented by (011) type I twins with low density of inner (001) compound twins. In a bending test, Ni 25 Ti 25 Hf 25 Cu 25 exhibits reversible strain of 2.4% under stress of 300 MPa. [Display omitted] • Ni 25 Ti 25 Hf 25 Cu 25 exhibits B2↔B19′ MT. • Low density of (001) compound twins into martensitic variants. • Recoverable strain of 2.4% under stress of 300 MPa. [ABSTRACT FROM AUTHOR]

Fuzzy C-means (FCM) clustering algorithm is a widely used method in data mining. However, there is a big limitation that the predefined number of clustering must be given. So it is very important to find an optimal number of clusters. Therefore, a new validity function of FCM clustering algorithm is proposed to verify the validity of the clustering results. This function is defined based on the intra-class compactness and inter-class separation from the fuzzy membership matrix, the data similarity between classes and the geometric structure of the data set, whose minimum value represents the optimal clustering partition result. The proposed clustering validity function and seven traditional clustering validity functions are experimentally verified on four artificial data sets and six UCI data sets. The simulation results show that the proposed validity function can obtain the optimal clustering number of the data set more accurately, and can still find the more accurate clustering number under the condition of changing the fuzzy weighted index, which has strong adaptability and robustness. [ABSTRACT FROM AUTHOR]

Detrital peat (organic carbon-enriched deposit) with high arsenic (As) content is widely distributed in sediments where groundwater As contamination exists. Iron sulfides often persist in these sediments under anoxic conditions. However, the mechanisms and pathways of formation of iron sulfides and its potential contribution in controlling As mobility are still poorly understood. In this study, we examined three As-contaminated peat sediments from the Hetao Basin in China to gain better understanding of the complex interplay between iron sulfides formation and As mobility. We employed high-resolution spectroscopic techniques, including X-ray absorption spectroscopy and 57Fe Mössbauer spectroscopy, coupled with electron microscopy to determine the speciation of iron sulfides and the associated As in the peat sediments. Pyrite (FeS 2) and metastable greigite (Fe 3 S 4) persisted in peat as end-members of S and Fe diagenetic pathways. The Fe-rich phyllosilicates and decaying plant tissues provided the ideal micro-environments for pyrite and greigite nucleation. Pyrite formation most likely occurred via the polysulfides pathway in the surface water-sediments interface during early diagenetic process, while the relative enrichment of reactive Fe compared to sulfide possibly inhibited the transformation of greigite to pyrite in such Fe-rich sediments. Our results revealed that the peat sediments could act as a stable sink for As immobilization under steady groundwater anoxic conditions, with As content up to 250 mg/kg and large proportions (40 to 60 wt.% As) sequestered in pyrite and greigite. Pyrite crystallites had up to 1 wt.% As content through the replacement of the S-I sites. Greigite crystallites had a relatively constant As content ranging from ∼500 to ∼1400 mg/kg. Instead of being adsorbed or structurally incorporated, arsenic formed distinct arsenic sulfide phase in the greigite-enriched sediments, which was analogous to realgar. The transfer of As from iron sulfides to ferrihydrite temporarily retarded As release into groundwater under slightly oxic groundwater conditions. However, the reductive dissolution of ferrihydrite and potential subsequent As re-release could be a source of As in groundwater under disturbed redox conditions. [ABSTRACT FROM AUTHOR]

Decarburization means carbon in rail material lost in the hot rolled process. It changes the microstructure of rail materials and will influence their rolling contact fatigue (RCF) characteristic. The objective of this study is to explore the effect of decarburized layer on rolling contact fatigue and propagation mechanism of crack under the wet condition using a rolling-sliding wear testing machine. The results show that the crack growth rate on the decarburized rail roller is over 4 times than that on the non-decarburized rail. Small pitting presents on the non-decarburized rail roller, which is dominated by transgranular crack. While, long mouth surface crack dominates on the decarburized rail roller and the cracks mainly grow along the ferrite line or the grain boundary. With the cycles increasing, the surface cracks of decarburized rail roller gradually break and forms spalling damage, eventually expands to bulk spalling. Meanwhile, the crack growth mechanism changes back to the transgranular propagation and propagates in depth with a large angle when the decarburization is worn off. [ABSTRACT FROM AUTHOR]

• Mg doping enlarges temperature span and reduces hysteresis. • Impurity phase and the order of magnetic phase transition control hysteresis. • Covalent bond length adjust the Curie temperature. Magnetocaloric materials with wide working temperature span and reversible magnetic transition are beneficial for the magnetic refrigerator. Besides of giant magnetocaloric effect, (Mn,Fe) 2 (P,Si) alloys exhibit significant thermal/magnetic hysteresis and a narrow working temperature span. In this work, the impact of Mg doping on the phase structure and magnetocaloric effect of Mn 1.05 Fe 0.9 P 0.5 Si 0.5- x Mg x alloys has been studied. The results show that all samples crystallize into Fe 2 P-type main phase with little impurity phase. After Mg doping, the lattice parameter a of the main phase increases from 6.027(0) Å to 6.049(0) Å and c decreases from 3.488(6) Å to 3.480(6) Å, which leads to the increase of Curie temperature. Density functional theory calculation results confirm that the Mg atom located on the 2c site can increase the covalent bond length, and then enhance the ferromagnetic coupling between atoms leading to the increase of Curie temperature. Moreover, the first-order magnetic phase transition of Mn 1.05 Fe 0.9 P 0.5 Si 0.5- x Mg x alloys is inhibited with the increase of Mg content, which results in the decrease of thermal/magnetic hysteresis and the increase of the effective working temperature span. For Mn 1.05 Fe 0.9 P 0.5 Si 0.48 Mg 0.02 alloy, it has a Curie temperature of about room temperature, effective refrigeration capacity of 291.7 J·kg−1, working temperature window of 46 K and magnetic entropy change of 9.4 J·kg−1·K−1. The alloy can be an excellent candidate in room temperature magnetic refrigeration devices with a wide temperature span. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the nutrient composition and AME n content of corn distillers dried grains with solubles (DDGS) to develop prediction equations for AME n in laying hens. Ten samples of DDGS ranging in ether extract (EE) from 21.8 to 177.8 g/kg (DM basis) were selected and were subsequently fed to laying hens to determine AME n content. A total of 176 62-week-old laying hens (Lohmann-Pink) were placed in metabolic cages (2 hens/cage) and were allotted into 11 dietary treatments (8 cages per treatment) according to hen-day egg production. Dietary treatments included a corn-soybean meal reference diet and 10 test diets. Each test diet was created by mixing the reference diet with 200 g/kg one of 10 DDGS samples at the expense of the energy-yielding ingredients (139.6 g/kg corn, 59.0 g/kg soybean meal, and 1.4 g/kg rapeseed oil). Experimental diets were fed in the 7-day adaptation period, followed by the 4-day total excreta collection period. Gross energy (GE) and crude protein (CP) of the experimental diets and excreta were determined to calculate AME n for each DDGS sample. On the DM basis, AME n of the 10 corn DDGS samples ranged from 729 to 2535 kcal/kg. Analyses were conducted to determine the GE, CP, EE, DM, crude fiber, neutral detergent fiber (NDF), acid detergent fiber (ADF), and ash content of the DDGS samples. Stepwise regression resulted in the following best-fit equation for AME n (DM basis) based on the coefficient of determination, SE, and the Mallows’ statistic (Cp): AME n , kcal/kg = 0.777 × GE (kcal/kg) − 5.39 × NDF (g/kg) (R 2  = 0.99; SE = 172; C p  = −3.37). These results suggested that the composition of corn DDGS may be used to predict AME n in laying hens. [ABSTRACT FROM AUTHOR]

Elastic-plastic response is greatly involved in the failure of wire ropes. Based on the derivation of the local deformation parameters of individual wire, an analytical model characterizing the elastic-plastic behavior for both wire strands and multi-strand ropes is developed in this paper. Also, the contact status within a multilayered strand is carefully studied to achieve a full understanding of wire stresses. Details of the surface strain fields of ropes are captured by 3D digital image correlation (3D-DIC) technique and the results agree well with the prediction of the present model. Varying loading conditions are considered to analyze the yielding and failure behavior of wire strands. It is found that the rotation of ropes (no matter its positive or negative) will increase the overall stress level over the wire cross section, however, restraining the rope ends leads to higher contact stress. Increasing the helix angle moderately may be an effective method to reduce the contact pressure of strand wires. Our model provides straightforward prediction of the elastic-plastic response of wire ropes and proves an effective tool for rope design due to a great reduction of time consuming in numerical simulations. [ABSTRACT FROM AUTHOR]

Uniaxial stress-controlled ratcheting behaviors of expanded PTFE (ePTFE) under cyclic compressive loads were tested. The effects of temperature, stress rate and mean stress on the ratcheting behaviors of ePTFE considering multiple load paths were discussed in detail. Results present that the steady ratcheting strain is rate-independent when the stress rate is less than about 0.1 MPa/s, while it approximately linearly decreases with increasing the stress rate for greater stress rate. Additionally, the steady ratcheting is temperature-independent when the temperature is greater than about 150 °C, but it nearly linearly increases with enhancing the temperature for lower temperature. Especially, the stress rate almost has little effect on the ratcheting strain of ePTFE at 200 °C. Moreover, the accumulated ratcheting strain enhances rapidly in about the first 80 cycles, and subsequently tends to shakedown in the subsequent cycles for each load path. Furthermore, if a higher stress is used in the prior cycling, the greater ratcheting strain may be produced, and a negative ratcheting strain rate can be obtained in the subsequent cycling with lower mean stress due to the greater strain hardening and deformation resistance produced by the previous higher stress. [ABSTRACT FROM AUTHOR]

We propose a scheme of all-optical clock recovery (AOCR) based on ultrahigh-order mode locking by a semiconductor optical amplifier (SOA), which can directly extract the optical clock from non-return-to-zero (NRZ) pseudo-random-binary-sequence (PRBS) data. Firstly we demonstrate that the active mode locking system can generate stable high repetition frequency ultrashort pulse train, and adjusting the modulator's bias voltage and polarization states one can realize doubling the repetition frequency. Due to robust mode locking configuration, we successfully realize the AOCR up to 40 Gbits/s from the PRBS (231-1) NRZ optical signals without NRZ to RZ conversion, while the signal to noise ratio of the recovered optical clock is more than 20 dB with high stability, and the pulse width is short as 1.85 ps. Owing to the ultrafast nonlinear polarization rotation in the SOA, our scheme can execute AOCR for data rate of 100 Gbits/s and more. • Propose and demonstrate a novel scheme of all-optical clock recovery (AOCR) based on ultrahigh-order (>2000th) mode-locked laser. • Using actively mode-locking technology we generate high-stable high-frequency (11 GHz) optical pulse train. • Successfully carry out the all-optical clock recovery from 40 Gbits/s PRBS NRZ optical signals. • The scheme has the ability to recover optical clock signals from 100 Gbits/s data. [ABSTRACT FROM AUTHOR]

A contact trajectory model of ball bearings under the dynamic condition was developed by the means of the development of the integrated multi-body dynamics and multi-freedom kinematics with the multi-interfacial contact mechanics. Subsequently, the general methodology was employed to investigate the dynamic contact performance of ball bearings, particularly for the contact trajectory along the raceways due to each ball against the inner and outer raceways. It was found that the radial loading and inner ring misalignment could lead to the deviation of the contact trajectory on the raceways. The variation of contact angle could bring into the correspondence with the deviation of the contact trajectory on the raceways. The oscillation frequency of the contact trajectory on the outer raceway was higher than one on the inner raceway either under the axial and radial loading or misalignment condition. [ABSTRACT FROM AUTHOR]

By using the high-pressure melt infiltration technique, a syntactic foam is fabricated with bulk metallic glass and alumina cenospheres. Compared to pure metallic glass foams, the new foam possesses a greatly enhanced energy absorbing capacity of 113.6 MJ m − 3 due to the combination of high strength, stability and ductility. It is shown that the high strength of the foam primarily results from alumina cenospheres, which enhance its stability and induce a stable stress platform. Both the collapse of struts and multiple shear bands in metallic glass matrix accommodate large deformation. [ABSTRACT FROM AUTHOR]

When the thicknesses of the outer layers are different in sandwich rolling, based on the different kinds of arrangements with the hard and soft materials the thickness ratio of two outer layers is changed differently during the rolling process. After the first analysis of the different outer thicknesses sandwich rolling, the rules for final thickness ratio of the two outer layers are proposed. In soft–hard–soft sheets (s–h–s) the thickness ratio of outer layers is remained in the final bonded sandwich sheet however in hard–soft–hard sheets (h–s–h) the thickness ratio is alleviated by sandwich rolling itself. A model based on slab method is proposed to analyze this phenomenon and 4 groups of experiments with Al and Cu as well as steel are conducted. The results calculated by the model well agree with those measured in the experiments. Then the accuracy and worthy of the model are verified. [ABSTRACT FROM AUTHOR]

The study aimed to determine the ileal phosphorus (P) digestibility (iPD) and the excreta P retention (ePR) of 5 monodicalcium phosphate (MCP) samples and 3 dicalcium phosphate (DCP) samples in broiler chickens and in Pekin ducks using the substitution method. A total of 720, 21-d-old Arbor Acres broiler chickens in experiment 1 and 720, 15-d-old Pekin ducks in experiment 2 were randomly allocated to 9 dietary treatments with 8 replicate cages (10 birds/cage) based on the similar mean body weight, respectively. The collection of excreta (for 72 h after a 3-d acclimation) and ileal digesta (after 6 d of feeding experimental diets) was done. The results showed the average iPD/ePR of MCP and DCP for broilers were 83.11%/74.52% and 75.34%/69.46% and for ducks were 79.37%/80.02% and 75.74%/76.44%, respectively. The iPD/ePR of MCP in broilers and the ePR of MCP in ducks were markedly higher (P < 0.05) than those of DCP. Our data suggest that using the substitution method to evaluate the bioavailability of feed phosphates has its own advantages; MCP has higher biological availability than DCP for broilers and ducks. [ABSTRACT FROM AUTHOR]

A new model characterizing the response of a multi-strand wire rope subjected to axial tension and axial torque is presented in this paper. Apart from most of previous approaches which deal with a straight wire strand, the present model fully considers the double-helix structure in multi-strand configuration. To be further, a new method to compute local deformation parameters (two curvatures and a twist defined by Love, 1944) of each wire is introduced. The proposed model well predicts the global stiffness of the rope. It is found that different friction states between adjacent wires can lead to quite a different distribution of local bending and torsion deformation of double-helix wire. The variations of stresses in double-helix wires along the rope axis are analyzed and the results show that torsion stress of a double-helix wire can be neglected when the rope is subjected to axial tension (axial torsion is restrained). The present model provides a new way to estimate the local deformation and stresses at the wire level, which sheds new insight into the understanding of the fatigue and failure behavior of the wire rope. [ABSTRACT FROM AUTHOR]

Light aroma style liquor is one of the basic types of Chinese liquor and is produced with a special technique of using a combination of three types of Daqu as starter culture. The succession of incubation temperature, a main operating parameter, and microbial composition in Daqu were investigated during the manufacturing process. The most significant difference in temperature occurred during the middle stage at which the highest and the lowest temperatures were detected in Houhuo (HH) and Qingcha ( QC), respectively. It was shown that for the counting data, the population of fungi was identical and that of bacteria was different between three types of Daqu. According to analysis results of microbial community structure using PCR-denaturing gradient gel electrophoresis ( PCR- DGGE), lactic acid bacteria were one of the dominant bacterial groups in all of Daqu and fungal diversity in QC was higher than that in HH and Hongxin (HX). The difference in incubation temperature led to the accumulation of different heat-tolerant and heat-sensitive fungi in the completed Daqu. PCA of DGGE profiles revealed that microbial community structure was distinct between three types of Daqu. It was presumed that temperature might play a decisive role in the formation of micro-organism composition in starter cultures. Significance and Impact of the Study The usage of a combination of three types of Daqu including Qingcha, Hongxin and Houhuo as starter culture is an important characteristic of production technology of Chinese light aroma style liquor. Micro-organisms from the environment naturally inoculated in Daqu are propagated to form the special microbial community under the control of several operating parameters, especially temperature, and finally play various roles in the fermentation process of liquor. An in-depth study of the relationship between incubation temperature and microbiota in Daqu during the manufacturing is fundamental to understand this complicated process and to prepare high-quality starter culture for fermentation. [ABSTRACT FROM AUTHOR]

Highlights: [•] A micro-sensor is developed to measure the internal temperature of a fuel cell. [•] A 3D CFD analysis is performed to analyze the fuel cell temperature. [•] In-plane temperature distribution is compared with experimental and numerical results. [Copyright &y& Elsevier]

Abstract: Laser weld bonding (LWB) is a hybrid welding technology that combines laser welding and adhesive bonding. In the hybrid welding process, the adhesive significantly affects the welding process and the property of the LWB joint. Results show that the adhesive partially decomposes in the heat-affected zone, the impaired size of which is mainly attributed to laser beam power. The property of the LWB joint is influenced by the thermal impaired area and adhesive thickness. To control the adhesive thickness and reduce the weld porosities in the fusion zone, a metallic interlayer is added in the welding process of LWB. [Copyright &y& Elsevier]

We put forward a novel scheme based on open-loop polarization control (OLPC) to retrieve and preserve arbitrary polarization states endlessly at uniform high speed, with average error of ~ 0.035 rad and time cost less than 300 μ s, which breaks through the limitation of those depend on close-loop polarization control (CLPC). Utilizing perfect modules we build an experimental OLPC system and establish its matrix model with control programme. Results show that the two-unit PC always has blind zone which can not be suppressed to zero, and the blind area centres exactly on the principal state of polarization (PSP) of the second unit. Then we start the third unit to retrieve the SOP from the blind area thus we achieve arbitrary SOPs on the Poincaré sphere endlessly. Subsequently, we demonstrate the great capacity of the OLPC scheme by successfully carrying on retrieving and preserving arbitrary SOPs disturbed by a polarization scrambler, while for sudden and huge disturbance it still shows quite robust and extremely strong. As a result, we fulfill the scheme in practical case of polarization encoded communication system with various environmental disturbance, and further reveal its prominent performance on improvement of signal quality and preservation of reliable communications, which manifests that it is suitable for field applications where exists much disturbance. [ABSTRACT FROM AUTHOR]

The formation of iron-sulfur-arsenic (Fe–S–As) minerals during biogeochemical processes in As contaminated aquifers remains poorly understood despite their importance to understanding As release and transport in such systems. In this study, X-ray absorption and Mössbauer spectroscopies complemented by electron microscopy, and chemical extractions were used to examine vertical changes of As, Fe and S speciation for the example of sediments in the Hetao Basin. Reduction of Fe(III), As(V) and SO 4 2- species were shown to co-occur in the aquifers. Iron oxides were observed to be predominantly goethite and hematite (36 – 12%) and appeared to decrease in abundance with depth. Furthermore, reduced As (including arsenite and As sulfides) and sulfur species (including S(-II), S(-I) and S0) increased from 16% to 76% and from 13% to 44%, respectively. Iron oxides were the major As carrier in the sediments, and the lower groundwater As concentration consists with less desorbable and reducible As in the sediments. The formation of As-Fe sulfides (e.g., As containing pyrite and greigite) induced by redox heterogeneities likely contribute to localized lower groundwater As concentrations. These results help to further elucidate the complex relationship between biogeochemical processes and minerals formation in As contaminated aquifers. ga1 • Speciation of As, S and Fe is mainly characterized by XAS. • Fe(III) oxides mainly include goethite and hematite, and the content decrease with depth. • The reduced As (As(III) species and As sulfides) species generally increases with depth. • Heterogenous Fe sulfides formation contributes to lower groundwater As concentration. [ABSTRACT FROM AUTHOR]

The magnetic properties, phase evolution, microstructure, and magnetic domain structure of melt-spun PrCo 5- x C x and PrCo 5 C y (x = 0–0.4 and y = 0–0.4) flakes are compared. Binary PrCo 5 flakes exhibit low intrinsic coercivity (i H c) of 3.2 kOe and thus a low magnetic energy product ((BH) max) of 4.4 MGOe, which is attributed to the coarse grains. By doping with proper amounts of C, the well-modified phase composition and uniformly refined microstructure and magnetic domains enhance the magnetic properties remarkably. Different phase compositions found for two approaches for doping PrCo 5 with C dominate the magnetic properties in addition to the fine microstructure. In PrCo 5- x C x (x = 0–0.4) flakes, the 2:17 phase suppressed by doping with C contributes to coercivity increase, and the largest i H c of 13.5 kOe with (BH) max = 8.8 MGOe is obtained for PrCo 4.9 C 0.1 flakes. For higher x , the formation of the 5:19 phase slightly reduces i H c to 7.2–8.8 kOe and (BH) max to 7.2–8.0 MGOe. In contrast, in the PrCo 5 C y (y = 0–0.4) series flakes, the increased amount of the 2:17 phase and the strengthened exchange coupling effect resulting from the refined microstructure caused by doping with a proper amount of C result in large (BH) max of 11.8 MGOe with i H c of 5.0 kOe for PrCo 5 C 0.3 flakes. • C doping significantly improves the magnetic properties of melt-spun PrCo 5 flakes. • C doping refines the sizes of the grains and magnetic domains. • Different phase compositions for two approaches for C doping dominate the magnetic properties. • In PrCo 5- x C x , the suppressed 2:17 phase resulting from doping with C contributes to high intrinsic coercivity. • In PrCo 5 C y flakes, the 2:17 phase well coupled with the 1:5 phase results in high (BH) max. [ABSTRACT FROM AUTHOR]

The limited slip systems of magnesium (Mg) and its alloys hamper their widespread applications in key areas. Rational design of such lightweight alloys requires fundamental knowledge of their microscopic plasticity mechanisms which, however, remain partially unresolved. Here, to obtain a better understanding of the plastic deformation mechanisms of Mg alloys, we performed tensile straining over a wide range of strain rates from 10−5 s−1 up to 2000 s−1, revealing for the first time the occurrence of a rate-dependent transition of the dislocation mechanisms. Such a shift of plasticity mechanisms is identified by two distinct activation volumes. Systematic experimental characterizations, such as transmission electron microscopy under two-beam conditions and synchrotron X-ray diffraction analysis, were employed to analyze both qualitatively and quantitatively the characteristics of dislocations at changing strain rates, revealing that the rate-dependent dislocation mechanisms are accompanied by the change of dislocation activities from easy-glide 〈 a 〉 dislocations to glissile 〈 c + a 〉 dislocations with increasing strain rates. Specifically, temporarily glissile 〈 c + a 〉 dislocations, enabled by a thermally activated transformation of dislocation cores from the dissociated configuration to the compact one, govern the plasticity at high strain rates. This is in stark contrast to the dominance of the easy-glide 〈 a 〉 dislocations at low strain rates. Meanwhile, it is found that abundant 〈 c + a 〉 dislocations do not necessarily lead to enhanced ductility, contrary to the common belief. We expect that these results will contribute to a further understanding of the plasticity mechanisms of Mg alloys. [Display omitted] [ABSTRACT FROM AUTHOR]

The materials combining high-entropy alloys with good mechanical properties and magnetic materials with a significant magnetocaloric effect are among the best candidates for magnetic refrigeration. For this purpose, the high-entropy alloys (MnNiSi) 1- x (FeCoGe) x (x = 0.4, 0.42, 0.45, and 0.47) were designed in this study. The effects of the Si/Ge ratio on the magnetocaloric effect and mechanical properties were also investigated. The results show that high-entropy alloy (MnNi) 0.6 Si 0.62 (FeCo) 0.4 Ge 0.38 possesses a Vickers hardness value of 580.6HV2 and compressive strength of 267 MPa with respect to a significant entropy change of 48.5 J·kg−1K−1 under a magnetic field of 5 T near the Curie temperature of 308.8 K. In order to clearly understand the origin of this excellent comprehensive performance, the influence mechanism of crystal structure and configurational entropy were explored. Furthermore, the first-principles calculations indicated that the magnetic properties mainly originate from Mn atoms located in 3 d sites and are influenced by the interaction between the Mn and Fe atoms. Additionally, the total magnetic moment and electron density are taken into account to reveal their influence on magnetocaloric properties. [Display omitted] • An MnNiSi-based magnetocaloric high-entropy alloys with excellent comprehensive properties were obtained. • The MnNiSi-based alloys have good mechanical properties (the Vickers hardness of 580.6 HV2 and compressive strength of 267 MPa). • The magnetocaloric effects of the MnNiSi-based alloys is 48.5 J·kg−1K−1 under 0–5 T at T C = 309 K. • The physical mechanism about good mechanical properties and magnetocaloric effects is revealed from the crystal structure, configurational entropy and electronic structure. [ABSTRACT FROM AUTHOR]

The present work, for the first time, quantitatively studies the evolution of both dislocations and deformation twins with various strain rates in an ATZ311 Mg alloy. Interrupted tensile tests were performed at the strain rates of 0.001, 1 and 600 s−1. Deformation twins were characterized by microscopy techniques and evaluated using the fractions of twin boundaries and twinned area. The average dislocation density and the relative fractions of dislocations with different Burgers vectors were determined from neutron diffraction data. It was found that the twin fraction increases remarkably and becomes saturated at lower strain rates (0.001-1 s−1), while the dislocation density only obtains an obvious enhancement at a much higher strain rate (600 s−1). Besides, the distinctively high flow stress at high strain rate leads to a substantial increase in the density of the hard-to-activate 〈 c + a 〉 -type dislocations, after the 〈 a 〉 -type dislocation density reaches rapidly its saturated value at a small strain level. The twinning modes with opposite polarities are able to coexist in the same grains because of the high local stress concentration at strain rates above 1 s−1. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Objectives Rapid and accurate identification of the causative pathogens of bloodstream infections (BSIs) is crucial for initiating appropriate antimicrobial therapy, which decreases the related morbidity and mortality rates. The aim of this study was to evaluate the usefulness of a newly developed multiplexed, bead-based bioassay system, the Quantamatrix Multiplexed Assay Platform (QMAP) system, obtained directly from blood culture bottles, to simultaneously detect the presence of bacteria and identify the genes for antibiotic resistance. Methods The QMAP system was used to evaluate 619 blood culture bottles from patients with BSIs and to compare the results of conventional culture methods. Results Using conventional bacterial cultures as the reference standard, the sensitivity, specificity, positive predictive value, and negative predictive value of the QMAP system for detection of bacterial pathogens in positive blood culture (PBC) samples were 99.8% ( n = 592, 95% CI 0.9852-1.000, p <0.001), 100% (95% CI 0.983-1.000, p <0.001), 100% (95% CI 0.9922-1.000, p <0.001), and 99.5% (95% CI 0.9695-1.000, p <0.001), respectively. In addition, sensitivity and specificity of the QMAP system for identification of the genes for antibiotic resistance were 99.4% ( n = 158, 95% CI 0.9617-0.9999, p <0.009) and 99.6% (95% CI 0.9763-0.9999, p <0.0001), respectively. Conclusions Obtaining results using the QMAP system takes about 3 hr, while culture methods can take 48–72 hr. Therefore, analysis using the QMAP system is rapid and reliable for characterizing causative pathogens in BSIs. [ABSTRACT FROM AUTHOR]

An approach to integrate InAs/GaAs quantum dots (QDs) active layer on SiO 2 /Si chip for single photon emitter is demonstrated. The QDs are embedded in GaAs/SiO 2 hybrid whispering gallery mode microdisks with the diameters of 10 and 5 μ m, corresponding to the quality factors (Q) of 2287 ± 167 and 4366 ± 208, respectively. Temperature tuning QD-cavity resonance is observed. The cavity-enhanced exciton spontaneous emission and single photon emission characteristics are studied. [ABSTRACT FROM AUTHOR]

• A custom built device to directly measure Δ T was designed, and its running frequency is up to 9 Hz and temperature span between about 235 K and 313 K. • The relationship between the temperature change of Gadolinium and alternating frequency of magnetic field under the near working condition can be directly obtained. • The theoretical model was built to investigate the effects of different influencing factors on the temperature change for MCE materials. In magnetic refrigerator, the magnetic induction and its alternating frequency have great influence on the magnetocaloric effects of materials. In order to relationship between the magnetocaloric effect and alternating frequency of magnetic field, the direct measurements of temperature change for Gadolinium near working conditions in alternating magnetic fields up to 9 Hz are carried out. In this device, the magnetic field is alternately changed by rotating the magnet while sample holder keeps stationary to defend the measurement signal interference. Results shows that the temperature change of Gd decreases from 1.5 K to 0.7 K with increasing field alternating frequency from 2.2 Hz to 9 Hz under magnetic field of 0.72T. Furthermore, based on the heat transfer process between sample, thermocouple and environment, we have established a theoretical model to investigate the effects of different influencing factors on the temperature change of Gadolinium. It reveals that near work conditions, there are lots of influencing factors to affect the temperature change, such as sample mass, applied magnetic field mode, adiabatic conditions, cycle frequency, and so on. The experimental and simulation results provide the guidance for screening the best candidate of magnetocaloric materials and developing the magnetic refrigerator. [ABSTRACT FROM AUTHOR]

Decarburization can remain on the surfaces of rail head steels and affect their wear and damage processes. The current research explored the influence of a decarburized layer on wear resistance and damage behavior of rail materials using a rolling–sliding wear testing machine. A decarburized layer decreases the hardness and wear resistance of rail steels, and the wear rate of a decarburized rail is over twice that of the same steel without decarburization. Multi-layer peeling appears on rail rollers without decarburization, but a decarburized layer changes the damage mechanism of the rail steel. With an increase in the depth of decarburization, the damage of rail roller turns from major spalling to pitting and peeling. In addition, surface fatigue cracks become more serious as depth increases. By contrast, shallow decarburization has little effect on rolling contact fatigue (RCF) of the rail material. Only when the depth of the decarburization exceeds a certain thickness (i.e., about 0.5 mm based on the present results), RCF damage sharply worsens as decarburization depth increases. Furthermore, adhesive wear features are obvious on the rail roller only when a decarburized zone remains at the wear surface. [ABSTRACT FROM AUTHOR]

• Flower-ball shaped Ag/Bi 2 WO 6 material was synthesized by hydrothermal method. • The gas sensing performance of Ag/Bi 2 WO 6 for ethanol was investigated for the first time. • Ag/Bi 2 WO 6 -based gas sensor has a fast response speed of up to 7 s for ethanol. • The sensor based on Ag/Bi 2 WO 6 showed low operating temperature of 240℃ to ethanol. Although Bi 2 WO 6 has been applied in various field, there are few reports on the application of gas sensing. In this work, Ag loaded flower-ball shaped Bi 2 WO 6 composite nanomaterials were synthesised by hydrothermal method. The Ag content was optimized for the first time. It was found that when 2 % Ag was added, Ag/Bi 2 WO 6 material possessed high sensitivity and low optimal working temperature (240℃). Compared with pure Bi 2 WO 6 (11 s and 32 s), Ag/Bi 2 WO 6 possessed ultrashort response and recovery time of 7 s and 25 s. It exhibited better ethanol gas selectivity and stability. Unique crystal structure and Ag catalysis may lead to the improvement of gas sensing performance. [ABSTRACT FROM AUTHOR]

Silver-doped diamond-like carbon (Ag-DLC) films are considered as promising materials for the surface modification of mechanical components and biological implants. The long-term stability of Ag-DLC films is essential for their commercial use and requires intensive investigation. In this study, DLC and 10.0 at.% Ag-DLC films were prepared using a hybrid deposition technique, and the existence and evolution of Ag atoms over time were systematically studied. The results show that Ag atoms with a lower Ehrlich–Schwoebel barrier than that of C atoms are more prone to interlaminar diffusion, refining the columnar structure of DLC films and thereby creating a compact structure. In the as-deposited Ag-DLC film, Ag atoms mainly existed as fine nanocrystals with sizes ranging from 3 to 5 nm. Ag elements diffused with time during its long-time service, and fine Ag nanocrystals agglomerated to form large nanocrystals. The calculation results by density functional theory confirmed that the proximity of Ag atoms can lower the system energy, rendering agglomeration thermodynamically stable. Molecular dynamics simulations verified the spontaneous migration and agglomeration behaviors of Ag atoms over time. This study was focused on the evolution of Ag-DLC films over time and would provide guidance for their use in long-term applications. [Display omitted] • Ag atoms are more prone to interlaminar diffusion than C atoms. • Ag nanocrystals in Ag-DLC film agglomerate during its long-time service. • Proximity of Ag atoms in Ag-DLC film is thermodynamically stable. • Ag atoms in Ag-DLC film spontaneously agglomerate over time. [ABSTRACT FROM AUTHOR]

Some important developments of adhesion strength research for thermal spray coating systems have been reviewed in the present paper. The following topics were included: the influence of spraying pre-treatment on adhesion strength, sources and mechanisms of adhesion strength in coatings, some algorithms and calculation of numerical models based on the energy release rate in fracture mechanics, and the effects and relative discussions of residual stress in thermal spray coatings on the adhesion strength. These topics would provide some important insights into life prediction of thermal spray systems based on the adhesion strength. [ABSTRACT FROM AUTHOR]

Flexible dye-sensitised solar cells (DSSCs) have been attracting considerable attention because of its flexibility and lightweight. In this study, TiO2 nano arrays with different morphologies were successfully synthesised on Ti foil via hydrothermal process. The effects of preparing conditions such as concentration of NaOH solution, hydrothermal temperature, reaction time and the additive NaCl on the formation of TiO2 nano arrays were systematically investigated by X-ray diffraction, scanning electron microscopy and photovoltaic tests. The growth mechanisms of nano arrays with different morphologies were also discussed. Moreover, the as-prepared TiO2 nanosheets array film was used as a photoanode of the flexible DSSC, a power conversion efficiency of 1.88% was obtained. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this study is to investigate the influence of friction modifiers on improving adhesion and surface damage of wheel/rail under low adhesion conditions. The results indicate that water, oil and leaves are very easy to bring low adhesion phenomena. Sand, alumina particle and abrasive block can improve adhesion coefficient under various low adhesion conditions. Sanding significantly aggravates wear and surface damage of wheel/rail materials. It is proposed that alumina particles are more suitable for improving adhesion of wheel/rail interface based on a comprehensive analysis of experimental results. [Copyright &y& Elsevier]

Due to its explosive, colorless and volatile nature, detection of ethanol is critical in daily life, industrial production and medical treatment. Metal oxide semiconductors (MOS) gas sensors have caught the attention of researchers due to their low cost and convenient detection. Indium oxide (In 2 O 3) is a typical wide band gap n-type semiconductor metal oxide widely used in detecting H 2 S, NO 2 , H 2 , and ethanol. This paper summarizes the strategies used in the last decade to improve the performance of gas sensors based on In 2 O 3 sensitive materials for ethanol detection. These strategies include modifying the morphology of indium oxide sensitive materials, doping and loading, building heterojunctions, and using composite new materials. In addition, the sensing mechanism for ethanol detection by gas sensors is presented. [ABSTRACT FROM AUTHOR]

In this paper, the mechanical properties of a cold-drawn wire (ε = 2.43) are modulated by simple annealing and the variation of its microstructure is characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and molecular dynamics (MD) simulation. The tensile ductility of the wire can be improved for about three times without compromising its strength when being annealed at 325 °C for 10–30 min. It is convinced that solid solution of carbon atoms from decomposed cementite lamellae improve the wire strength at low temperature annealing (up to 250 °C) and make the wire strength basically equal the as-drawn state even though cementite lamellae are weakened by cementite recrystallization at 325 °C. And reversely the weakening cementite layers lead to the great improvement of wire ductility at this time since it relaxes the restriction to the moving of dislocations. At higher annealing temperature, the wire strength decreases with the growth of cementite and ferrite grains. The appearance of nano-recrystallized cementite grains at a medium annealing temperature may be a critical factor governing the enhanced wire mechanical properties. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Thermodynamic properties of selected asymmetric methyl ethers are obtained. • Rate constants for hydrogen abstraction reactions by NO 2 on asymmetric methyl ethers are calculated. • The effects of ether bond and size of alkyl are investigated. • Bell-Evans-Polanyi correlation is observed in asymmetric methyl ethers and NO 2 systems. Abstract Hydrogen abstraction by NO 2 from asymmetric methyl ethers by NO 2 is theoretically investigated based on first-principles calculations in order to constrain their combustion models, including methyl ethyl ether(MEE), methyl n -propyl ether (MNPE), methyl i -propyl ether (MIPE), methyl n -butyl ether (MNBE), and methyl t -butyl ether (MTBE). We obtain the rate constants and branching ratios at 500–2000 K, and the dependence of reactivity on ether sizes and the reaction sites on the ethers. The cis -HONO channel is the most important one, followed by the HNO 2 and trans -HONO channels. On the hand, the size of alkyl and the reaction site significantly affect the reactivity. Hydrogen abstraction mainly occurs at the C site (adjacent to the ether bond) of the long-chain alkyl. Moreover, the linear Bell-Evans-Polanyi correlation is observed for the hydrogen abstraction reactions between the asymmetric methyl ether and NO 2. [ABSTRACT FROM AUTHOR]

Abstract Background A variety of complex drug regimens are offered to kidney transplant recipients after transplantation. This study aimed to evaluate the behavioral and physiological outcomes of pharmaceutical care in this population. Methods A cross-sectional prospective study was conducted, which collected and categorized kidney transplant recipients according to pharmaceutical care. In the IR group, patients had received irregular pharmaceutical care after transplantation, and in the RE group, patients had received regular intervention. Intervention included face-to-face interview, checkup for laboratory examinations, discovery of drug-related problems, and pharmaceutical consultation. Baseline knowledge for self-care was tested for patients in both groups. Correct concepts and medication guidance were consistently provided to enable patients to understand the importance of rejection prevention and knowledge for medication and renal care after transplantation. After 12 months, the same test was used to evaluate the outcomes for pharmaceutical care and a satisfaction questionnaire was used to assess for pharmacy service. Results The study results revealed that patients in the RE group possessed better knowledge for self-care (P <.001); however, the differences at 12 months became insignificant (P =.72) after patients in the IR group had also received routine pharmaceutical care. Besides, serum creatinine level of the RE patients was stable without significant variation (P =.93), but it demonstrated a rising trend in IR patients (P <.01). Patients were greatly satisfactory with the intervention. Conclusions A consistent post-transplantation pharmaceutical care service is effective to substantially improve knowledge of post-transplantation self-care. Pharmaceutical care should be started as early as possible during the pre-transplant period and continue in a long-term follow-up. Highlights • A consistent pharmaceutical care service is effective to improve self-care knowledge. • Allograft function might be impaired in the beginning of the post-transplantation period. • Pharmaceutical care should be started as early as possible after transplantation. • Pharmaceutical care should continue in a long-term follow-up. [ABSTRACT FROM AUTHOR]

• Effects of the initial microstructure of the railway wheel steel on adiabatic shearing behavior is examined. • The localized deformation of proeutectoid ferrite is preferent to that of pearlite. • The localized deformation is more serious in the wide lamellar structure than in the narrow lamellar structure. • The rim is more prone to adiabatic shearing compared with the web. Adiabatic shearing behavior in the web and the rim of high-speed train railway wheel steel was investigated using a split Hopkinson pressure bar (SHPB) with hat-shaped punch shear technique. Different initial microstructure characteristics were observed in the web and the rim specimens experiencing different heat treatment. For the first time we show that the pre-eutectoid ferrite deforms at first and pearlite interlamellar spacing has a significant influence on structural softening sequence during shear band evolution in the railway wheel steel, and shear bands are more prone to emerge in the rim. [ABSTRACT FROM AUTHOR]

1. Paired box (Pax7) gene is a member of the paired box family and plays a critical role in animal growth and muscle development. However, the molecular characterisation of the goosePax7gene is unknown. 2. The open-reading frame of goosePax7is composed of 1509 bp, which encodes a protein of 503 amino acids and shares high homology with Pax7 of other birds. 3. Ten single-nucleotide polymorphisms were identified in the genomic DNA sequence, 8 located in the intron region and two located in the exon region. 4. Association analysis showed the C122T locus was significantly associated with the body weight of Zhedong-White geese in week 4, 6, 8, 10 and 12. 5. It was concluded that the goosePax7gene may be an important candidate gene for goose growth traits and marker-assisted selection. [ABSTRACT FROM AUTHOR]

Agouti signalling protein (ASIP) is an endogenous antagonist of melanocortin-1 receptor (MC1R) and is involved in the regulation of pigmentation in mammals. The objective of this study was to identify and characterise the ASIP gene in domestic goose.The goose ASIP cDNA consisted of a 44-nucleotide 5ʹ-terminal untranslated region (UTR), a 390-nucleotide open-reading frame (ORF) and a 45-nucleotide 3ʹ-UTR. The length of goose ASIP genomic DNA was 6176 bp, including three coding exons and two introns.Bioinformatic analysis indicated that the ORF encodes a protein of 130 amino-acid residues with a molecular weight of 14.88 kDa and an isoelectric point of 9.73.Multiple sequence alignments and phylogenetic analysis showed that the amino-acid sequence of ASIP was conserved in vertebrates, especially in the avian species.RT-qPCR showed that the goose ASIP mRNA was differentially expressed in the pigment deposition tissues, including eye, foot, feather follicle, skin of the back, as well as in skin of the abdomen. The expression level of the ASIP gene in skin of the abdomen was higher than that in skin of the back.Those findings will contribute to further understanding the functions of the ASIP gene in geese plumage colouring. [ABSTRACT FROM AUTHOR]

The grinding process for maintaining the railroad rails can affect their performance. A rail grinding friction testing apparatus was developed to investigate the effects of rotational speed of grinding stone on removal behavior of rail material. The rail-grinding stone contact consists of a round, flat grinding stone and two test specimens made from Mn–steel rails that are pressed against the face of the stone. The effects of grinding wheel rotational speed on the abrasive removal mechanism of rail material are explored in detail. The results indicate that as the grinding wheel rotational speed increases, the friction coefficient, the surface roughness of rail specimens and the width of the wear grooves decrease. The grinding wear volume, the microindentation hardness of the rail specimens and the surface temperature-rise all increase as the number of grinding cycles increase. Wear debris collected during the test is composed of round particles and curled cutting chips. The debris is mainly composed of Fe 3 O 4 , FeO and Fe. As grinding rotational speed increases, the content of Fe 3 O 4 and FeO increases but the width of the cutting chips decreases. [ABSTRACT FROM AUTHOR]

The objective of this study is to investigate the braking tribological characteristics of two kinds of metro brake shoe materials using a sub-scale frictional braking machine. The results indicate that the friction coefficient of braking interface has a close relationship with the velocity and pressure. The increase of velocity and pressure raises the temperature-rise of braking interface. The increasing velocity and pressure aggravate the wear of brake shoe rings. However, the wear loss of wheel rings decreases with increasing pressure. The braking surface of brake shoe rings exhibits adhesive wear and spalling, while obvious plowing and abrasive wear are dominant on the braking surface of wheel rings. According to the experimental results, it is concluded that brake shoe B material can be used to prevent and alleviate the occurrence and evolution of groove wear on wheel tread. This might be attributed to the higher percentage of FeC 3 versus FeS 2 in its composition compared with brake material A. Field testing, completed to 100,000 km thus far, has to be completed on these materials and further work should be performed for evaluating the effect of different brake shoe materials on the groove wear of wheel tread in the field. [ABSTRACT FROM AUTHOR]

Large-strain extrusion machining (LSEM) has been emerged as a promising severe plastic deformation methodology for the creation of nano or ultra-fined grained materials. To realize deformation control, the key issue involved is the strain estimation in LSEM. In order to characterize the deformation field in LSEM, the experiments of LSEM oxygen-free high-conductivity copper were conducted by using a specially designed LSEM device. Based upon the deformation field measured by high speed imaging and digital image correlation (DIC), a new strain estimation model considering the extrusion process of constraint is proposed in this paper. The theoretical predicted strain agrees well with the measurements. [ABSTRACT FROM AUTHOR]

The microstructure and corrosion fatigue behavior under artificial seawater environment of 100-mm-thick Ti–6Al–4V alloy joint via vacuum electron beam welding (EBW) was systematically characterized. Obvious microstructural heterogeneity along the transverse direction of as-welded joint was observed. Bimodal-phases microstructure of granular α colonies and β strips compose the microstructure of the base metal (BM). While the microstructure of fusion zone (FZ) comprises single-phase acicular α/α′ martensite. Under corrosive environment of artificial seawater, FZ shows a lower growth rate of corrosion fatigue cracking (CFC) than that in the BM. Increasing content of residual gas contamination worsens the resistance against corrosion fatigue of the FZ of Ti–6Al–4V alloy joint. Results of local electrochemical characterization indicates that the FZ shows a better resistance against electrochemical corrosion than that of the BM. It is deduced that the slower growth rate of CFC observed in the FZ originates from the combined effects of the excellent corrosion resistance of martensite microstructure and the obstructions of interfaces of fine α/α′ laths against growth of CFC. Moreover, the growth mechanisms of CFC in the BM and FZ were discussed involving the microstructural heterogeneity of the EBW joint. Image 1 • Elucidating the correlation between the microstructure and corrosion fatigue behavior of thick Ti–6Al–4V EBW joint. • Microstructure heterogeneity between base metal (BM) and fusion zone (FZ) affects obviously the corrosion fatigue behavior. • Subtle change of welding vacuum shows significant influence on the welding quality. • Growth rate of corrosion fatigue cracking (CFC) in BM is higher than that in FZ. • CFC prefers to traverse β phase grains in BM, while penetrates the acicular α/α′ lath in FZ. [ABSTRACT FROM AUTHOR]

Interfaces in complex oxide heterostructures provide a new platform for creating novel functionalities. Up to now, the investigation on manipulating vertical interface in vertically aligned nanocomposite films is very limited. By manipulating vertical interface, a significantly reduction of leakage current and Ohmic conduction behavior were achieved in BaTiO 3 :Sm 2 O 3 films, which may enable the design of advanced nanostructures with emergent functionalities. • Ohmic conduction behavior was realized up to 1000 kV/cm. • Leakage current of BaTiO 3 is reduced by the formation of sharp vertical interface. • Enhanced ferroelectric polarization in BaTiO 3. Interface in complex oxide heterostructures provides a new platform for uncovering emergent physical phenomena and engineering novel functionalities. Compared to the control of lateral interface in bilayer or multilayer complex oxide films, the investigation on manipulating the vertical interface in vertically aligned nanocomposite films is rarely studied so far. Here, the vertical interface effect on the leakage behavior of vertically aligned nanocomposite BaTiO 3 :Sm 2 O 3 films grown on (1 1 1) Nb-SrTiO 3 (Nb-STO) substrates is reported. We found that the vertical interface without visible misfit dislocations is formed between BaTiO 3 and Sm 2 O 3. Consequently, the leakage mechanism is determined to be Ohmic conduction up to an electric field of 1000 kV/cm. Also, the leakage current is reduced to be around 3 × 10−7 A/cm2, which is almost two and three orders of magnitude lower than that of BaTiO 3 :Sm 2 O 3 /(0 0 1) Nb-STO and pure BaTiO 3 /(1 1 1) Nb-STO films, respectively. This work demonstrates the ability to realize Ohmic conductive mechanism at high electric field and further provides a new pathway to reduce leakage current and improve ferroelectric polarization of ferroelectric oxide films by manipulating the vertical interface, which opens the door to the design of advanced nanostructures with the emergent functionalities. [ABSTRACT FROM AUTHOR]

In this study, the mechanisms for solids breakthrough in upflow anaerobic sludge blanket (UASB) configured anaerobic membrane bioreactors (AnMBRs) have been described to establish design parameters to limit membrane fouling. As the sludge blanket develops, two periods can be identified: (i) an initial progressive enhancement in solids separation provided through sludge blanket clarification, via depth filtration, which sustains downstream membrane permeability; and (ii) sludge blanket destabilisation, which imposed solids breakthrough resulting in a loss in membrane permeability. The onset of sludge blanket destabilisation was identified earlier in the flocculent AnMBR, which was ascribed to an increased gas production, caused by hydrolysis within the sludge blanket at extended solids residence time. Whilst hydrolysis also induced higher gas productivity within the granular AnMBR, solids breakthrough was not evidently observed during this period, and was instead only observed as the sludge blanket approached the UASB overflow. However, solids breakthrough was observed earlier for both reactors when treating wastewater with lower temperatures. This was explained through characterisation of the settling velocity of discrete particles from the sludge blanket of both MBRs; solids washout was evidenced to be induced by the increase in fluid viscosity with a reduction in temperature, which lowered terminal particle settling velocity. Nevertheless, particle settling velocity was comparable for particles from both sludge blankets. We therefore propose that the enhanced stability imparted by the granular AnMBR is due to the higher inertial force of the dense granular sludge. From this study, we suggest that similarly low levels of membrane fouling can be achieved within flocculent AnMBR by managing solids retention time to constrain sludge bed height and excess hydrolysis, together with adopting an upflow velocity based on particle buoyancy at the lowest expected operating temperature. Image 1 • Sludge blanket development enhances solids separation via depth filtration. • Entrapped solids hydrolysis promotes excess gas production and solids breakthrough. • Lower temperature leads to easier solids washout due to increase in fluid viscosity. • Granular is better than flocculent inoculum sludge for sludge blanket stablisation • Design and operation interventions are proposed to limit solids breakthrough. [ABSTRACT FROM AUTHOR]

• Biocarrier addition can effectively reduce membrane fouling even at low C/N ratio. • Bulk sludge is significantly improved with biocarrier to achieve low fouling. • Denitrification bacteria accumulates in biocarrier and improves nitrogen removal. • Biocarrier addition can partially overcome drawbacks of low C/N ratio. The polyvinyl formal (PVFM) biocarrier addition in a membrane bioreactor (MBR) was evaluated at high and low carbon/nitrogen (C/N) ratio of 20.0 and 6.7. Results indicated that static biocarrier addition could enrich nitrification and denitrification bacteria, dominating by Tauera, Amaricoccus and Nitrosospira at the genus level and slightly improved the total nitrogen removal even at a low C/N ratio. The bulk sludge characteristics (such as bigger particle size, lower SMP, lower SMP P/C) were also significantly changed in the hybrid MBR (HMBR), leading to a more sustainable membrane operation. The biocarrier addition also reduced the relative abundance of Sphingobacterials_unclassified, Ohtaekwangia and Rhodocyclaceae_unclassified at the genus level, indicating less membrane fouling in the HMBR. Consequently, HMBR with static PVFM addition could partially overcome the drawback of low C/N ratio for total nitrogen removal and membrane fouling control, providing a more resilient MBR to the undesirable environment such as low C/N ratio. [ABSTRACT FROM AUTHOR]