Search

Due to the increase of the water content in the produced fluid from oilfield development and the limitation of space on offshore platforms, compact wastewater treatment equipment is urgently needed to treat oily wastewater. In this regard, a horizontal compact cyclone air flotation device was designed, and the flow field distribution and oil-water separation performance of the cyclone cylinder area of the device were systematically studied by the Fluent numerical simulation method. The effects of cyclone cylinder structure, inlet pipe diameter, oily sewage inlet velocity and inlet oil content on oil-water separation were explored. The results showed that when the inlet pipe diameter was 20 mm and the oily sewage inlet velocity was 2 m/s, the swirl tube structure using the guide vane could obtain a better flow field distribution. The larger the oily sewage inlet velocity, the more serious the attenuation of tangential velocity. When the height of the swirl cylinder was 100-300 mm, the tangential velocity attenuation was larger, and the attenuation was small within the height of 300-650 mm. Under the same oily sewage inlet velocity, increasing the inlet pipe diameter could increase the volume fraction of the oil phase in the cyclone tube. Increasing the oily sewage inlet velocity would lead to a decrease in the volume fraction of the oil phase. The volume fraction of oil phase in the cyclone tube was distributed in a “U” shape, and increased with the increase of inlet oil content, which was directly proportional to the inlet oil content.

In this paper, we introduce a novel two-degree-of-freedom piezoelectric stack hybrid energy harvester including a piezoelectric stack and a set of piezoelectric layers. By incorporating a mechanical stopper and bending leaf springs to achieve frequency up-conversion, we significantly enhance the voltage response of the system. We compare the output performance of prototypes with different spring stiffness. The experimental results show that, at a frequency of 7.8 Hz and an acceleration of 0.8 g, the piezoelectric layers on the lower beam of bending leaf springs generate a peak voltage of 18.92 V, and its instantaneous output power is 32 mW. Meanwhile, the piezoelectric stack produces a peak voltage of 28.56 V, with an instantaneous output power of 3.83 W. Moreover, an increase in the stiffness of the bending leaf spring leads to a decrease in voltage response and power output. This research can facilitate the development of hybrid piezoelectric self-powered applications.

The study presents a unifying methodology for characterizing micromixers, integrating both experimental and simulation techniques. Focusing on Dean mixer designs, it employs an optical evaluation for experiments and a modified Sobolev norm for simulations, yielding a unified dimensionless characteristic parameter for the whole mixer at a given Reynolds number. The results demonstrate consistent mixing performance trends across both methods for various operation points. This paper also proposes enhancements in the evaluation process to improve accuracy and reduce noise impact. This approach provides a valuable framework for optimizing micromixer designs, essential in advancing microfluidic technologies.

Shell–tube heat exchangers are commonly used equipment in large-scale industrial systems of wastewater heat exchange to reclaim the thermal energy generated during industrial processes. However, the internal surfaces of the heat exchanger tubes often accumulate fouling, which subsequently reduces their heat transfer efficiency. Therefore, regular cleaning is essential. We aim to detect circle holes on the end surface of the heat exchange tubes to further achieve automated positioning and cleaning tubes. Notably, these holes exhibit a regular distribution. To this end, we propose a circle-permutation-aware object detector for heat exchanger cleaning to sufficiently exploit prior information of the original inputs. Specifically, the interval prior to the extraction module extracts interval information among circle holes based on prior statistics, yielding prior interval context. The following interval prior fusion module slices original images into circle domain and background domain maps according to the prior interval context. For the circle domain map, prior-guided sparse attention using prior a circle–hole diameter as the step divides the circle domain map into patches and performs patch-wise self-attention. The background domain map is multiplied by a hyperparameter weak coefficient matrix. In this way, our method fully leverages prior information to selectively weigh the original inputs to achieve more effective hole detection. In addition, to adapt the hole shape, we adopt the circle representation instead of the rectangle one. Extensive experiments demonstrate that our method achieves state-of-the-art performance and significantly boosts the YOLOv8 baseline by 5.24% mAP50 and 5.25% mAP50:95.

Abstract Topoisomerase 3α (TOP3A) is an enzyme that removes torsional strain and interlinks between DNA molecules. TOP3A localises to both the nucleus and mitochondria, with the two isoforms playing specialised roles in DNA recombination and replication respectively. Pathogenic variants in TOP3A can cause a disorder similar to Bloom syndrome, which results from bi‐allelic pathogenic variants in BLM, encoding a nuclear‐binding partner of TOP3A. In this work, we describe 11 individuals from 9 families with an adult‐onset mitochondrial disease resulting from bi‐allelic TOP3A gene variants. The majority of patients have a consistent clinical phenotype characterised by bilateral ptosis, ophthalmoplegia, myopathy and axonal sensory‐motor neuropathy. We present a comprehensive characterisation of the effect of TOP3A variants, from individuals with mitochondrial disease and Bloom‐like syndrome, upon mtDNA maintenance and different aspects of enzyme function. Based on these results, we suggest a model whereby the overall severity of the TOP3A catalytic defect determines the clinical outcome, with milder variants causing adult‐onset mitochondrial disease and more severe variants causing a Bloom‐like syndrome with mitochondrial dysfunction in childhood.

Abstract The accomplishment of condition monitoring and intelligent maintenance for cantilever structure‐based energy harvesting devices remains a challenge. Here, to tackle the problems, a novel cantilever‐structure freestanding triboelectric nanogenerator (CSF‐TENG) is proposed, which can capture ambient energy or transmit sensory information. First, with and without a crack in cantilevers, the simulations are carried out. According to simulation results, the maximum change ratios of natural frequency and amplitude are 1.1% and 2.2%, causing difficulties in identifying defects by these variations. Thus, based on Gramian angular field and convolutional neural network, a defect detection model is established to achieve the condition monitoring of the CSF‐TENG, and the experimental result manifests that the accuracy of the model is 99.2%. Besides, the relation between the deflection of cantilevers and the output voltages of the CSF‐TENG is first built, and then the defect identification digital twin system is successfully created. Consequently, the system is capable of duplicating the operation of the CSF‐TENG in a real environment, and displaying defect recognition results, so the intelligent maintenance of the CSF‐TENG can be realized.

Abstract Background To determine an optimized treatment protocol during the COVID-19 epidemic for patients with closed fracture and delayed surgery. Methods The epidemic data of three hospitals, randomly selected from different administrative regions of Wuhan, were analyzed retrospectively from 23 January to 31 March 2020. Changes in the number of confirmed cases per day (cumulative and new) of each region were tracked as a reflection of changing epidemic risk levels. The risk level map was drawn. The epidemic status, treatment protocols, and treatment efficiencies for patients with closed fracture in the three hospitals were compared. Results Overall, 138 patients with closed fracture were admitted. Each hospital had established its own protocol, according to the initial perceived risk. Based on the risk level map, over the study period, the risk levels of the three regions changed independently and were not in sync. All patients recovered and were timely discharged. No staff member was detected with COVID-19. Conclusions The COVID-19 risk level of each area is dynamic. To optimize medical resources, avoid cross-infection, and improve efficiency, changes in epidemic risk should be monitored. For patients with closed fracture, treatment protocols should be adjusted according to changes in epidemic risk.

A fundamental understanding of fatigue-failure mechanisms is key to develop robust structural materials. Here the authors report a high entropy alloy with enhanced fatigue life by ductile transformable multicomponent B2 precipitates, as revealed by combined experimental and simulation methods.

Abstract Background Blood coagulation factor VIIa (FVIIa) plays its critical physiological role in the initiation of hemostasis. Even so, recombinant FVIIa is successfully used as a bypassing agent for factor VIII or IX in the treatment of bleeds in patients with severe hemophilia with inhibitors. To investigate the utility of more potent FVIIa variants with enhanced intrinsic activity, molecules such as V21D/E154V/M156Q‐FVIIa (FVIIaDVQ) were designed. Methods Surface plasmon resonance was used to characterize the binding of mAb4F5 to FVIIaDVQ and related variants. X‐ray crystallography was used to determine the structure of the Fab fragment of mAb4F5 (Fab4F5). Molecular docking and small angle X‐ray scattering led to a model of FVIIaDVQ:Fab4F5 complex. Results The binding experiments, functional effects on FVIIaDVQ and structure of mAb4F5 (originally intended for quantification of FVIIaDVQ in samples containing FVII(a)) pinpointed the epitope (crucial role for residue Asp21) and shed light on the role of the N‐terminus of the protease domain in FVIIa allostery. The potential antigen‐combining sites are composed of 1 hydrophobic and 1 negatively charged pocket formed by 6 complementarity‐determining region (CDR) loops. Structural analysis of Fab4F5 shows that the epitope interacts with the periphery of the hydrophobic pocket and provides insights into the molecular basis of mAb4F5 recognition and tight binding of FVIIaDVQ. Conclusion The binary complex explains and supports the selectivity and functional consequences of Fab4F5 association with FVIIaDVQ and illustrates the potentially unique antigenicity of this FVIIa variant. This will be useful in the design of less immunogenic variants.

Deletions and duplications in mitochondrial DNA (mtDNA) cause mitochondrial disease and accumulate in conditions such as cancer and age-related disorders, but validated high-throughput methodology that can readily detect and discriminate between these two types of events is lacking. Here we establish a computational method, MitoSAlt, for accurate identification, quantification and visualization of mtDNA deletions and duplications from genomic sequencing data. Our method was tested on simulated sequencing reads and human patient samples with single deletions and duplications to verify its accuracy. Application to mouse models of mtDNA maintenance disease demonstrated the ability to detect deletions and duplications even at low levels of heteroplasmy.

From a sketch image or text description, generating a semantic and photographic face image has always been an extremely important issue in computer vision. Sketch images generally contain only simple profile information but not the detail of the face. Therefore, it is difficult to generate facial attributes accurately. In this paper, we treat the sketch to face the problem as a face hallucination reconstruction problem. In order to solve this problem, we propose an image translation network by exploiting attributes with the generated adversarial network. And it can significantly contribute to the authenticity of the generated face by supplementing sketch image with the additional facial attribute feature. The generator network is composed of a feature extracting network and downsampling-upsampling network, both networks use skip-connection to reduce the number of layers without affecting network performance. The discriminator network is designed to examine whether the generated faces contain the desired attributes or not. In the underlying feature extraction phase, our network is different from most attribute-embedded networks, we fuse the sketch images and attributes perceptually. We set the network sub-Branch A and B, which receive a sketch image and attribute vector in order to extract low-level profile information and high-level semantic features. Compared with the state-of-the-art methods of image translation, the performance of the proposed network is excellent.

With the change of epoch, the standard of male attractiveness is also changing. Analyzing the trend of facial features changes over time in different environments can reveal the influence of social development on facial attractiveness. In this paper, we propose a method to analyze the trend of facial features of Chinese male. First, a face database with Chinese male of different times is established and rated by raters of different ages. Second, the machine learning method is used to rate face images of different times for verifying the change of male aesthetic. Then, the retrained Inception v3 model is used to realize facial shape classification. After that, the change trend of face shape is analyzed by using massive data. Finally, the change characteristics of the eyebrow are analyzed by calculating the geometric parameters of the eyebrow model, including the area, length, and average width of the eyebrow. Compared with other researches on facial attractiveness, the proposed method can deeply understand the guiding trend of popular culture on facial attractiveness in different times.

The Ti41Cu31Zr10Pd13 (at.%) metallic glasses are promising for bone-implantation applications due to their exceptional bio-compatibility. However, Pd, as a noble element, keeps the fabrication cost high and prevents the industrial sale production of these alloys. Searching for replacements with comparable glass-forming ability and ductility but lower cost turns out to be imperative. In this article, we used similar but less expensive elements to substitute Pd for such a goal. Specifically, 1–4 at.% Ni and Pt are incrementally used to replace Pd in the base alloy. Careful characterizations of the glass-forming ability and the compressive ductility suggest that the Ti41Cu36Zr10Pd10Ni3 metallic glass retains both the glass-forming ability and the ductility, but cuts down the alloy cost by ∼22.66%. The Ti41Cu36Zr10Pd12Pt1 metallic glass, despite no substantial trimming in the alloy cost, doubles the ductility and fairly maintains the glass-forming ability. The serrated flow is observed on the plastic flow of most metallic glasses investigated and is quantitatively studied in the framework of the self-organized criticality. Our work provides important insights on defining appropriate commercialization routes of Ti-based bulk metallic glasses. Keywords: Glass forming ability, Plasticity, Serrated flow, Self-organized criticality

High-entropy alloys: cluster-and-glue atoms behind exceptional properties A cluster-and-glue model of atomic arrangements explains the yield strength and mechanical response of high entropy alloys. Inspired by metallic glass, a team led by William Yi Wang at China’s Northwestern Polytechnical University and collaborators in the United States of America used molecular dynamics to build different atomic arrangements of refractory high entropy alloys consisting of four or more elements. Depending on atomic size and the periodic table group of each atom, some atoms organized into clusters while others glued the clusters together. Chemical bonds broke and formed with plastic deformation as the alloys went from one atomic arrangement to another via the glue atoms, causing defect avalanches explaining the serrated mechanical response of high entropy alloys. Taking into account atomic arrangement may thus help us predict the properties of high entropy alloys.

Intramembrane proteases hydrolyze peptide bonds within the cell membrane as the decision-making step of various signaling pathways. Sporulation factor IV B protease (SpoIVB) and C-terminal processing proteases B (CtpB) play central roles in cellular differentiation via regulated intramembrane proteolysis (RIP) process which activates pro-σK processing at the σK checkpoint during spore formation. SpoIVB joins CtpB in belonging to the widespread family of PDZ-proteases, but much remains unclear about the molecular mechanisms and structure of SpoIVB. In this study, we expressed inactive SpoIVB (SpoIVBS378A) fused with maltose binding protein (MBP)-tag and obtained the solution structure of SpoIVBS378A from its small angle X-ray scattering (SAXS) data. The fusion protein is more soluble, stable, and yields higher expression compared to SpoIVB without the tag. MBP-tag not only facilitates modeling of the structure in the SAXS envelope but also evaluates reliability of the model. The solution structure of SpoIVBS378A fits closely with the experimental scattering data (χ2= 1.76). Comparing the conformations of PDZ-proteases indicates that SpoIVB adopts a PDZ-protease pattern similar to the high temperature requirement A proteases (HtrAs) rather than CtpB. We not only propose that SpoIVB uses a more direct and simple way to cleave the substrates than that of CtpB, but also that they work together as signal amplifiers to activate downstream proteins in the RIP pathway.

High-entropy alloys (HEAs) are a novel class of alloys that have many desirable properties. The serrated flow that occurs in high-entropy alloys during mechanical deformation is an important phenomenon since it can lead to significant changes in the microstructure of the alloy. In this article, we review the recent findings on the serration behavior in a variety of high-entropy alloys. Relationships among the serrated flow behavior, composition, microstructure, and testing condition are explored. Importantly, the mechanical-testing type (compression/tension), testing temperature, applied strain rate, and serration type for certain high-entropy alloys are summarized. The literature reveals that the serrated flow can be affected by experimental conditions such as the strain rate and test temperature. Furthermore, this type of phenomenon has been successfully modeled and analyzed, using several different types of analytical methods, including the mean-field theory formalism and the complexity-analysis technique. Importantly, the results of the analyses show that the serrated flow in HEAs consists of complex dynamical behavior. It is anticipated that this review will provide some useful and clarifying information regarding the serrated-flow mechanisms in this material system. Finally, suggestions for future research directions in this field are proposed, such as the effects of irradiation, additives (such as C and Al), the presence of nanoparticles, and twinning on the serrated flow behavior in HEAs.

For this study, the effects of thermal annealing and compressive strain rate on the complexity of the serration behavior in a Zr-based bulk metallic glass (BMG) was investigated. Here, as-cast and thermally-annealed (300 °C, 1 week) Zr52.5Cu17.9Ni14.6Al10Ti5 BMG underwent room-temperature compression tests in the unconstrained condition at strain rates of 2 × 10−5 s−1 and 2 × 10−4 s−1. The complexity of the serrated flow was determined, using the refined composite multiscale entropy technique. Nanoindentation testing and X-ray diffraction characterization were performed to assess the changes in the microstructure and mechanical properties of the BMG that occurred during annealing. The results indicated that the BMG did not crystallize during annealing in the prescribed heating condition. Nanoindentation tests revealed that annealing led to a significant increase in the depth-dependent nanoindentation hardness and Young’s modulus, which were attributed to the structural relaxation in the glass. Furthermore, both annealing and an increased strain rate resulted in a marked enhancement in the complexity of the serrated flow during compression. It was concluded that the increase in the sample entropy with increasing strain rate is related to an increase in the number of defect interactions during the serrated flow.

This paper studies a single crane scheduling problem arising in the cold-rolling material warehouse in an iron and steel enterprise. A set of coils stored in two levels are needed to be picked up and transported to designated positions. If a required coil is at the upper level, it can be picked up right away and transported to its designated position (transportation operation). A required coil at the lower level cannot be picked up until all its blocking coils at the upper level are moved to other positions (shuffling operation). One overhead crane is used to perform all the transportation and shuffling operations. Our problem is to schedule the crane operations so as to all required coils retrieve to their designated positions in the shortest possible time (makespan). Since the problem is shown to be NP-hard, a genetic algorithm (GA) is proposed. We identify some analytical properties which enable us to develop an effective heuristic algorithm as initial solutions of the GA. We further analyze its performance from the worst-case point of view. To evaluate the average performances, a numerical test compared with some existing methods is carried out and its results show the good quality of the proposed algorithm.

The study presents a unifying methodology for characterizing micromixers, integrating both experimental and simulation techniques. Focusing on Dean mixer designs, it employs an optical evaluation for experiments and a modified Sobolev norm for simulations, yielding a unified dimensionless characteristic parameter for the whole mixer at a given Reynolds number. The results demonstrate consistent mixing performance trends across both methods for various operation points. This paper also proposes enhancements in the evaluation process to improve accuracy and reduce noise impact. This approach provides a valuable framework for optimizing micromixer designs, essential in advancing microfluidic technologies. [ABSTRACT FROM AUTHOR]

Shell–tube heat exchangers are commonly used equipment in large-scale industrial systems of wastewater heat exchange to reclaim the thermal energy generated during industrial processes. However, the internal surfaces of the heat exchanger tubes often accumulate fouling, which subsequently reduces their heat transfer efficiency. Therefore, regular cleaning is essential. We aim to detect circle holes on the end surface of the heat exchange tubes to further achieve automated positioning and cleaning tubes. Notably, these holes exhibit a regular distribution. To this end, we propose a circle-permutation-aware object detector for heat exchanger cleaning to sufficiently exploit prior information of the original inputs. Specifically, the interval prior to the extraction module extracts interval information among circle holes based on prior statistics, yielding prior interval context. The following interval prior fusion module slices original images into circle domain and background domain maps according to the prior interval context. For the circle domain map, prior-guided sparse attention using prior a circle–hole diameter as the step divides the circle domain map into patches and performs patch-wise self-attention. The background domain map is multiplied by a hyperparameter weak coefficient matrix. In this way, our method fully leverages prior information to selectively weigh the original inputs to achieve more effective hole detection. In addition, to adapt the hole shape, we adopt the circle representation instead of the rectangle one. Extensive experiments demonstrate that our method achieves state-of-the-art performance and significantly boosts the YOLOv8 baseline by 5.24% mAP50 and 5.25% mAP50:95. [ABSTRACT FROM AUTHOR]