Maintenance Of Structure Research Articles

Dynamic Optimization Method of Knowledge Graph Entity Relations for Smart Maintenance of Cantilever Roadheaders

The fault maintenance scenario in coal-mine equipment intelligence is composed of videos, images, signals, and repair process records. Text data are not the primary data that reflect the fault phenomenon, but rather the secondary processing based on operation experience. Focusing on the difficulty of extracting fault knowledge from the limited textual maintenance process records, a forward static full-connected topology network modeling method based on domain knowledge from four dimensions of physical structure, internal association, condition monitoring, and fault maintenance, is proposed to increase the efficiency of constructing a fault-maintenance knowledge graph. Accurately identifying the intrinsic correlation between the equipment anomalies and the faults’ causes through only domain knowledge and loosely coupled data is difficult. Based on the static full-connected knowledge graph of the cantilever roadheader, the information entropy and density-based DBSCAN clustering algorithm is used to process and analyze many condition-monitoring historical datasets to optimize the entity relationships between the fault phenomena and causes. The improved DBSCAN algorithm consists of three stages: firstly, extracting entity data related to fault information from the static fully connected graph; secondly, calculating the information entropy based on the real dataset describing the fault information and the historical operating condition, respectively; and thirdly, comparing the entropy values of the entities and analyzing the intrinsic relationship between the fault phenomenon, the operating condition data, and the fault causes. Based on the static full-connected topology storage in the Neo4j database, the information entropy and density-based DBSCAN algorithm is computed by using Python to identify the relationship weights and dynamically display optimized knowledge graph topology. Finally, an example of EBZ200-type cantilever roadheader for smart maintenance is studied to analyze and evaluate the forward and four-mainlines knowledge graph modeling method and the dynamic entity relations optimization method for static full-connected knowledge graph.

Advances in transposable elements: from mechanisms to applications in mammalian genomics

It has been 70 years since Barbara McClintock discovered transposable elements (TE), and the mechanistic studies and functional applications of transposable elements have been at the forefront of life science research. As an essential part of the genome, TEs have been discovered in most species of prokaryotes and eukaryotes, and the relative proportion of the total genetic sequence they comprise gradually increases with the expansion of the genome. In humans, TEs account for about 40% of the genome and are deeply involved in gene regulation, chromosome structure maintenance, inflammatory response, and the etiology of genetic and non-genetic diseases. In-depth functional studies of TEs in mammalian cells and the human body have led to a greater understanding of these fundamental biological processes. At the same time, as a potent mutagen and efficient genome editing tool, TEs have been transformed into biological tools critical for developing new techniques. By controlling the random insertion of TEs into the genome to change the phenotype in cells and model organisms, critical proteins of many diseases have been systematically identified. Exploiting the TE’s highly efficient in vitro insertion activity has driven the development of cutting-edge sequencing technologies. Recently, a new technology combining CRISPR with TEs was reported, which provides a novel targeted insertion system to both academia and industry. We suggest that interrogating biological processes that generally depend on the actions of TEs with TEs-derived genetic tools is a very efficient strategy. For example, excessive activation of TEs is an essential factor in the occurrence of cancer in humans. As potent mutagens, TEs have also been used to unravel the key regulatory elements and mechanisms of carcinogenesis. Through this review, we aim to effectively combine the traditional views of TEs with recent research progress, systematically link the mechanistic discoveries of TEs with the technological developments of TE-based tools, and provide a comprehensive approach and understanding for researchers in different fields.

Soft Measurement of Rare Earth Multi-Element Component Content Based on Multi-LightVGG Modeling

The current hardware equipment used to detect the content of each element component in the rare earth extraction process has a complex structure and high maintenance cost. A modeling method for the soft measurement of rare earth multi-element component content is proposed to address this issue. This method uses the Multi-LightVGG multi-tasking learning model and the Multi Gradient Descent Algorithm based on Optimized Upper Bound (MGDA-OUB) to optimize the model for each prediction task and find the Pareto optimal solution. After conducting several experiments, the Multi-LightVGG model loaded with MGDA-OUB has lower MRE, RMSE for Pr, Nd prediction, and MAX(|error|) for Nd prediction than the Multi-LightVGG model without MGDA-OUB by 0.3778%, 0.5208%, 0.0015, 0.0015, and 0.1985%, respectively; and the MRE and RMSE of the Multi-LightVGG model for Pr and Nd prediction under the same optimization conditions are lower than those of Multi-ResNet18 by 0.3297%, 0.5423%, 0.0019, and 0.002, respectively, thus indicating that MGDA-OUB can effectively solve multiple task-specific Pareto solutions to avoid possible conflicts between specific tasks, while the Multi-LightVGG model, compared to the Multi-Resnet18 model, has a backbone network that can effectively capture the abstract representations in the images of the rare earth-extraction mixed solution, which in turn improves the prediction accuracy of the content of each elemental component.

NCAPD3 Prompts Diffuse Large B-Cell Lymphoma Progression through Modulating SIRT1 Expression in H3K9 Monomethylation-Dependent Manner

Chromosomal instability, including number and structure abnormality, is the critical molecular basis in lymphoid oncogenesis. Condensin, a family of structural maintenance of chromosome complexes, has been shown to regulate chromosome compaction and segregation during mitosis. NCAPD3, a HEAT-repeat subunit of condensin II, plays a dominant role in condensin-mediated chromosome dynamics, whose abnormalities are related to tumorigenesis and developmental disorders but remain unexplored in lymphoma. This study aims to unravel the expression, molecular function and mechanism of NCAPD3 in diffuse large B-cell lymphoma (DLBCL). We first elucidated the expression of NCAPD3 in DLBCL. Lymph node tissues from 70 DLBCL patients and 35 reactive hyperplasia cases were collected with informed consent approved by the Medical Ethical Committee of Shandong Provincial Hospital. Higher NCAPD3 expression was identified in DLBCL tissues and correlated with advanced Ann Arbor stage and higher IPI score. The survival analysis presented patients with higher NCAPD3 suffered shorter survival (P=0.045). Meanwhile, upregulation of NCAPD3 was validated in DLBCL cells compared with normal CD19+ B-cell. We further explored the biological functions of NCAPD3 in DLBCL and constructed NCAPD3-knockdown, knockout and overexpression models. Deficiency of NCAPD3 impeded cell proliferation, induced apoptosis and increased the sensitivity to doxorubicin and ibrutinib. Instead, NCAPD3 overexpression facilitated cell proliferation and therapeutic resistance. In vivo experiments further indicated that xenograft DLBCL mice with deficient NCAPD3 presented delayed tumor growth. These suggested NCAPD3 promoted DLBCL progression. Strikingly, we found knocking down NCAPD3 disturbed the mitosis, triggering the formation of aneuploidy, due to its function in chromatin structure and dynamics. Hence, we further portrayed the transformation of chromosome architecture under different NCAPD3 expression. Chromosome spreads exhibited chromosomes became slim and elongated upon NCAPD3 overexpression, instead, NCAPD3 knockout triggered short and highly-curled transformation with the global upregulation of H3K4me3, an indication of transcriptional activation and chromatin decompaction (Figure 1). This suggested NCAPD3 could modulate transcriptional activity. Therewith, we investigated how NCAPD3 regulated gene transcription. We examined the interacting proteins of NCAPD3 by mass spectrometry and Clusters of Orthologous Groups analysis revealed they were mainly enriched in RNA processing and modification, chromatin dynamics and cell cycle control. Of them, transcription factor, GTF2I, may be responsible for NCAPD3-mediated transcription regulation. Coimmunoprecipitation (co-IP) verified their interaction and chromatin immunoprecipitation (ChIP) presented they were both located on the promoter of target gene, SIRT1. We further examined SIRT1 expression after regulating NCAPD3 expression, showing a significantly positive correlation. This suggested NCAPD3 could support SIRT1 transcription via being anchored by GTF2I on the promoter of SIRT1. We further elucidated the potential mechanism how NCAPD3 regulated SIRT1 expression. Previous study found that NCAPD3 could interact with histone methylation markers in mammalian genome, thus, we explored whether NCAPD3 could modulate the SIRT1 expression via recognizing the histone methylation marker on SIRT1 promoter. Co-IP assay identified the interaction between NCAPD3 and monomethylation of lysine residue K9 of histone H3 (H3K9me1), an active promoter tag, in DLBCL and ChIP assay verified the location of H3k9me1 on SIRT1 promoter. When NCAPD3 downregulated, H3K9me1 on SIRT promoter diminished, ruining the transcription of SIRT. To clarify whether the oncogenic effects of NCAPD3 was mediated by SIRT1, we conducted functional reversion assays, showing regulating SIRT1 partially reversed the effects of NCAPD3. The above suggested NCAPD3 prompted DLBCL progression through modulating SIRT expression in H3k9me1-mediated manner. In conclusion, this study unraveled that dysregulation of NCAPD3 could disturb chromosome compaction and segregation, induce genome instability and alter the transcription of SIRT1 via modulating H3k9 monomethylation, which provided novel insights into NCAPD3-based targeting strategy for DLBCL.

SMC4 Loss of Function Is a New Cause of Inherited Bone Marrow Failure

Inherited bone marrow failure syndromes (IBMFS) are a rare, heterogenous group of syndromes that are characterized by cytopenias, bone marrow hypocellularity, and in many cases an increased risk of transformation to myeloid malignancy. Presentation with severe pancytopenias at birth is reported but occurs very rarely, and more often neonatal pancytopenia is attributed to congenital and acquired infections or other acquired causes. We present the case of a preterm neonate with pancytopenia from birth and bone marrow failure of no known infectious, other acquired, or genetic etiology. Antenatal findings were notable for non-immune hydrops fetalis at 30 weeks of gestation prompting delivery. The initial laboratory evaluation revealed a normocytic, reticulocytopenic, severe anemia; leukopenia with an absolute neutrophil count of 500; and severe thrombocytopenia. Viral testing, including parvovirus, rubella, herpes simplex virus, cytomegalovirus, adenovirus, and enterovirus, was negative. Additional testing, including a chromosomal microarray, mitochondrial genome sequencing, chromosome stress testing, neonatal alloimmune thrombocytopenia panel, and telomere length analysis, was non-diagnostic. Bone marrow biopsy showed a remarkably hypoplastic marrow without evidence of dysplasia or cytogenetic abnormalities. The proband underwent matched unrelated donor hematopoietic stem cell transplant, and died approximately one month later from post-transplantation complications including hepatic veno-occlusive disease, thrombotic microangiopathy, CNS and pulmonary hemorrhages, pseudomonal sepsis, and multi-organ dysfunction. Autopsy was significant for microscopic pancreatic atrophy with lipomatous hypertrophy and osteopenia. The proband and parents underwent clinical exome testing which was non-diagnostic and then consented to research reanalysis of the exome data. Research reanalysis identified the infant was compound heterozygous for predicted deleterious variants in the Structural Maintenance of Chromosomes 4 gene (SMC4), inherited in trans from each unaffected parent (c.2478_2479ins10 splice site variant predicted to alter splicing and c.T591G; p.Y197X). Germline variants in SMC4 have not been reported as a cause of human disease; however, somatic variants are observed in several cancers including in acute myeloid leukemia (AML). SMC4 is a highly conserved protein that forms a heterodimer with Structural Maintenance of Chromosomes 2 (SMC2) in the condensin II protein complex. This complex is important for chromosome condensation, cell division, and DNA repair. Within hematopoietic tissue, SMC4 expression is higher in hematopoietic stem and progenitor cells when compared with mature lineage cells. Given the predicted loss of function from both SMC4 variants, we performed RNAseq on proband and control fibroblasts. This showed a roughly 10-fold decrease in total SMC4 transcript levels (Figure 1A). A significant proportion of the transcript present was comprised of an aberrantly spliced transcript characterized by exon 15 skipping. We therefore hypothesized that loss of SMC4 expression leads to a cell intrinsic defect in hematopoiesis. To test this hypothesis, we used CRISPR-Cas9 gene editing to generate knockout of SMC4 in human cord blood CD34+ hematopoietic stem/progenitor cells (HSPCs) before culturing cells in an all-colony forming unit (CFU) assay. Using two independent small guide RNAs, we were able to achieve approximately 80% knock-down. After 14 days in culture, we observed a striking decrease in CFUs when compared with controls, though the composition of colony types was relatively unchanged (Figure 1B). Using next-generation sequencing, we observed a significant decrease in remaining SMC4 genome edits at the end of the culture period, suggesting a relative disadvantage of SMC4-edited cells for survival and/or proliferation. In summary, we describe a preterm infant with congenital bone marrow failure without an identifiable cause and link this phenotype to biallelic loss-of-function variants in SMC4. This is the first study identifying SMC4 as a novel gene that causes inherited bone marrow failure, and further experiments are underway to validate this finding.

Copper selenide - Porous carbon derived from metal-organic frameworks as an efficient electrocatalyst for methanol oxidation

In the present study, a metal-organic framework (Cu-MOF) was used as the precursor for synthesis of carbon-encapsulated copper selenides (namely, Cu2-xSe@PCs). After carbonization of Cu-MOF to Cu/Cu2O@PCs, the selenidation process was applied by selenium powder at 500 °C to form Cu2-xSe@PCs. Scanning electron microscopy showed the maintenance of the initial octahedral structure of Cu-MOF after carbonization and selenidation. Nickel foam (NF) was modified with the prepared composite and used as anode in electrochemical cells. Cyclic voltammetric study in alkaline solution (in the absence of methanol) showed highly increased peak currents (∼4 times) on Cu2-xSe@PCs/NF compared to that on Cu/Cu2O@PCs/NF. The electrocatalytic oxidation of methanol in alkaline solution showed lower overpotential and much higher catalytic currents (629.3 mA cm−2 in methanol 0.5 M) on Cu2-xSe@PCs/NF compared to that on Cu/Cu2O@PCs/NF (204.6 mA cm−2). The long-term stability of the proposed electrocatalyst was studied by chronopotentiometry and chronoamperometry. High potential stability was observed when a constant current (22.3 mA cm−2) was drawn from the cell (>4 h). Similar stability was observed for the catalytic current when a constant voltage (1.62 V vs. RHE) was imposed on the electrode in chronoamperometry. In addition, more than 88.5 % of the catalytic current remained after the application of 300 consecutive potential cycles to Cu2-xSe@ PCs/NF in the alkaline solution of methanol. The electrocatalyst was also used in a two-electrode system. Polarization and power density plots showed improved catalytic methanol oxidation by using Cu2-xSe@PCs/NF compared to Cu/Cu2O@PCs/NF. Excellent electrocatalytic properties of the proposed composite towards methanol, long-term stability and the simple synthetic route of the mono-metal electrocatalyst make it a good candidate as the anode of direct methanol fuel cells.

Technical Properties of Normal Concrete with Alum Additive

Concrete is a widely used construction material due to its numerous advantages in terms of structural performance, cost-effectiveness, implementation, and maintenance. Compressive strength is a critical property that must be considered for concrete used as a structural component. This property can be influenced by various factors, including the addition of chemical substances to the concrete mix. Alum is commonly employed as a water clarifying agent. In concrete mixtures, alum decomposes into aluminium and trioxide sulfate compounds found in cement. Incorporating alum into concrete is expected to enhance the aluminium and cement content. This research aims to investigate the technical properties of normal concrete when supplemented with alum. The technical properties under consideration include slump value and compressive strength, with a fixed mix proportion of cement: sand: gravel = 1:2:3. Alum is added in proportions of 2%, 4%, 6%, and 8% by weight of cement in the concrete mix. The findings of this present study indicate that the highest compressive strength is achieved in concrete specimens with 2% alum addition by weight of cement, reaching 35.629 MPa, while the corresponding slump value is 7.75 cm

Evaluation of Local Scour along the Base of Longitudinal Training Walls

This study proposes a new empirical model for estimating local scour along the base of longitudinal training walls for granular riverbeds. The model’s performance was rigorously assessed through experiments conducted in an open-channel flume, encompassing variations in granulometric characteristics, slope, and flow rates. The investigation involved a comparative analysis of six commonly employed equations for scour estimation. The results consistently demonstrated a tendency of the selected equations to overestimate scour depth within the longitudinal structures. In contrast, the new proposed equation considers factors such as the well-graded granular bedding represented by the Coefficient of uniformity (Cu) and the embedment of the longitudinal wall. This allows for a more robust identification of the scour behavior of longitudinal walls. This research enhances our comprehension of local scour in riverbeds. It provides engineers and researchers with a valuable tool for more accurate predictions, thereby contributing to the improved design and maintenance of river environment structures.

Suitability of tree Species for Forest Management in the Amazon

Theoretical framework: Phytosociology is the essential decision-making tool to ensure the maintenance of the forest structure after exploitation. Objective: The study aimed to evaluate the suitability of tree species for timber production based on phytosociological parameters, in order to assist exploration decisions in forest management plans. Method: Installation of six permanent plots of 2500m² to monitor tree species and obtain phytosociological relationships. Results and discussion: There was a low variation in the structure of species throughout the area, determining the establishment of different species in the varied conditions of the site, which denotes a forest suitable for management. Implications of the research: Phytosociological indicators for decision-making in logging in the Amazon. Originality/value: The relationships between tree species with metrics to define the remaining structure of the forest, maintaining viable economic production.

RecN spatially and temporally controls RecA-mediated repair of DNA double-strand breaks

RecN, a bacterial structural maintenance of chromosomes-like protein, plays an important role in maintaining genomic integrity by facilitating the repair of DNA double-strand breaks (DSBs). However, how RecN-dependent chromosome dynamics are integrated with DSB repair remains unclear. Here, we investigated the dynamics of RecN in response to DNA damage by inducing RecN from the PBAD promoter at different time points. We found that mitomycin C (MMC)-treated ΔrecN cells exhibited nucleoid fragmentation and reduced cell survival; however, when RecN was induced with arabinose in MMC-exposed ΔrecN cells, it increased a level of cell viability to similar extent as WT cells. Furthermore, in MMC-treated ΔrecN cells, arabinose-induced RecN colocalized with RecA in nucleoid gaps between fragmented nucleoids and restored normal nucleoid structures. These results suggest that the aberrant nucleoid structures observed in MMC-treated ΔrecN cells do not represent catastrophic chromosome disruption but rather an interruption of the RecA-mediated process. Thus, RecN can resume DSB repair by stimulating RecA-mediated homologous recombination, even when chromosome integrity is compromised. Our data demonstrate that RecA-mediated presynapsis and synapsis are spatiotemporally separable, wherein RecN is involved in facilitating both processes presumably by orchestrating the dynamics of both RecA and chromosomes, highlighting the essential role of RecN in the repair of DSBs.

Effects of fertilization practices and understory on soil health and oil palm performances in smallholdings: An Indonesian case study

CONTEXTSmallholders play a considerable role in oil palm production in Indonesia. Their specific constraints lead to contrasted plot management, especially for fertilization and understory vegetation. Studies disentangling the agro-environmental impacts of oil palm smallholders' management practices at the plot scale remain scarce. The extent to which smallholders' practices affect both agronomic and environmental performances is still to be investigated with robust in-field studies to provide improvement tracks. OBJECTIVEThis study aimed at investigating the effects of both fertilization and understory vegetation management on soil health and oil palm performances. It explored a gradient of management practices, within homogeneous soil and climate conditions and historical development. The objective was to isolate and decipher the specific effects of some key practices on the overall plantation performances. METHODSWe surveyed 16 ex-plasma oil palm smallholders' 25-year old plots, gathering detailed information on management and implementing field measurements (48 points). For soil health assessment, we applied Biofunctool® that consists of nine in-site indicators informing on the soil ability to transform carbon, recycle nutrient and maintain its structure. For the oil palm performances, we relied on conventional appraisal parameters, such as yields, leaf area and nutrient leaf analyses. RESULTS AND CONCLUSIONSOur results highlighted that fertilization, especially potassium, played a significant role in sustaining oil palm performances. Understory vegetation had a direct and positive effect on soil structure maintenance indicators. Soil structure improvement was correlated with enhanced oil palm performances. Those results highlighted that, besides nutritional aspects, increasing plot biodiversity through understory vegetation maintenance was associated with enhanced soil health hence potential greater ecosystem functions. SIGNIFICANCEThe findings have implications in terms of better understanding the effects of combined farming practices on the soil-oil palm continuum. It especially highlighted the key role of understory vegetation to improve soil structure maintenance without competing with oil palms in the studied context.

Self‐Powered Intelligent Damper Integrated Triboelectric‐Electromagnetic Hybrid Unit for Vibration In Situ Monitoring of Stay Cables

AbstractMonitoring and controlling the vibration of bridge cables can maintain the health of the bridge structure and prolong the service life. This work proposes a novel self‐powered intelligent damper (SID) integrated triboelectric‐electromagnetic hybrid unit for vibration in situ monitoring of stay cables. Among them, the sensing function of the SID is realized by an arched membrane triboelectric nanogenerator (AM‐TENG), and the energy harvesting is realized by a three‐phase electromagnetic generator (TP‐EMG). The working principle and performance are investigated. Rotating and linear experimental platforms are built to verify the SID's low‐frequency (0.25–1.50 Hz) performance, including sensing, power generation, and vibration reduction. The experimental result indicates that the fitting vibration speed coefficient of the bridge cable with the AM‐TENG signal frequency is 0.990. In addition, the TP‐EMG achieves a peak power of 1.21 W. At 0.1 A power supply, the SID can output a damping force of 50 N. Finally, an experimental system is constructed to verify the viability of the SID in bridge cable vibration monitoring and vibration reduction. This work provides a feasible solution for further optimizing the bridge structure health monitoring and maintenance system.

A novel quantile-based sequential optimization and reliability assessment method for safety life analysis

Safety life analysis under random uncertainty is an effective tool for guiding the maintenance and design of structures. However, existing methods for safety life analysis employ a nested solution strategy by dichotomy, with inner time-dependent reliability analysis, resulting in high computational costs. This paper proposes a quantile-based sequential optimization and reliability assessment (QSORA) method to overcome the shortcoming of nested solution strategy in safety life analysis. In QSORA, the probability constraint is first equivalently transformed into a quantile constraint corresponding to the target time-dependent failure probability (TDFP). Then, the coupling relationship between the search for safety life and the quantile estimation is then eliminated, and the safety life is solved iteratively through a series of cycles. Each cycle contains two independent executions: an equivalent deterministic optimization and quantile estimation of extreme performance function corresponding to the target TDFP. Finally, a sampling-based method combined with a double-loop Kriging model is proposed to efficiently estimate the quantile, and it is embedded into QSORA to improve the efficiency of safety life analysis. Two learning functions are adopted to ensure the accuracy of double-loop Kriging model. Numerical and engineering examples verify the efficiency and accuracy of the proposed method for safety life analysis.

Inner superhydrophobic materials based on waste fly ash: Microstructural morphology of microetching effects

Superhydrophobic technology in construction can effectively improve the barrier ability of the substrate to harmful water-based erosion media, among which the coating scheme is the most practical choice at present, but it may easily fail due to mechanical damage. Therefore, the current research focus has shifted to the development of internal superhydrophobic materials (ISMs) that maintain stable hydrophobicity even under harsh conditions of use and do not rely on expensive fluor-based surface modifications. In this study, the topological structure of waste denitrification fly ash (FA) was constructed using an innovative method, by precisely controlling the etching medium concentration and the form of FA, a one-step process was developed to create ISM with excellent matrix strength and strong waterproof properties. In this study, the alkaline environment generated by FA hydration was used to induce the silica-hydrogen bond dehydrogenation of polymethylhydrosiloxane (PMHS) and the free ammonium ion deamination to toughen the film; PMHS and liquid phase are used to produce the oil-water phase, and the oil film adheres to the surface of the generated NASH and sodium silicate crystals; The porous inner surface of ISM is formed with hydrogen- and ammonia-induced rough structure; The synthesized ISM retains superhydrophobicity and less compressive strength reduction value, and its superhydrophobicity even at damaged or friction interfaces. The material preparation method provides a good foundation and innovative design concept for the seepage prevention and maintenance of concrete structures, the construction of aerated FA bricks, the preparation of foam insulation materials, and the batch utilization of waste FA.

A digital twin framework for civil engineering structures

The digital twin concept represents an appealing opportunity to advance condition-based and predictive maintenance paradigms for civil engineering systems, thus allowing reduced lifecycle costs, increased system safety, and increased system availability. This work proposes a predictive digital twin approach to the health monitoring, maintenance, and management planning of civil engineering structures. The asset-twin coupled dynamical system is encoded employing a probabilistic graphical model, which allows all relevant sources of uncertainty to be taken into account. In particular, the time-repeating observations-to-decisions flow is modeled using a dynamic Bayesian network. Real-time structural health diagnostics are provided by assimilating sensed data with deep learning models. The digital twin state is continually updated in a sequential Bayesian inference fashion. This is then exploited to inform the optimal planning of maintenance and management actions within a dynamic decision-making framework. A preliminary offline phase involves the population of training datasets through a reduced-order numerical model and the computation of a health-dependent control policy. The strategy is assessed on two synthetic case studies, involving a cantilever beam and a railway bridge, demonstrating the dynamic decision-making capabilities of health-aware digital twins.

Hanger replacement and corrosion assessment in a suspension bridge

Due to repetitive harsh environments and ever-increasing traffic on long-span suspension bridges, damages such as corrosion may occur in hangers, eventually necessitating their replacement. This replacement task is challenging as it affects various adjacent components of the suspension bridge, namely, the main cable, the main girder, the cable clamp, and other hangers. This paper investigates damage induced by corrosion in a hanger of a suspension bridge and validates a multi-point lifting approach through numerical investigation and implementation. The numerical investigation takes into account three controlling factors, namely, (i) the tension of the temporary and adjacent hangers; (ii) the displacements of the main cable and the main girder; (iii) the anti-sliding coefficient of the cable clamp. Based on the finite element (FE) investigation, the replacement was successfully implemented using the five-point lifting approach. In addition, a corrosion distribution map is utilized to visualize the corrosion characteristics of the replaced hanger, leading to recommendations for enhancing the durability of hangers. In conclusion, this study sheds light on the design and replacement of long hangers in other suspension bridges and provides valuable insights for improving the durability and maintenance of such structures.

ANALYSIS OF INJURIES AND DEATH OF PEOPLE AS A RESULT OF VIOLATION REQUIREMENTS IN UKRAINE

Problem statement. The exploring reseach shaws that physical wear and tear of technological equipment, machines and mechanisms that fail to meet safety requirements causes the main number of injuries at coal, chemical, construction industry, etc. A large share of work- and non-workplace injuries with fatal consequences occur on the wear and tear of buildings and structures that are in an emergency state. The injuries are mostly common caused due to violation of fire safety rules, rules of labor protection, and unappropriate sanitary and hygienic working conditions. Thus, there are more than 50 thousand fires in Ukraine every year, in which people die, and material damage exceeds hundreds of millions of hryvnias, incidental losses are 20 times bigger. The reseach shows that a significant part of accidents happens to whokers who perform one-time jobs working under subcontract, without an employment. An average of 140−180 people in Ukraine are injured at work every day, 20 of them become disabled, 4−5 of those people die. The purpose of the article is to reseach the causes and consequences of violations’ requirements of regulatory and legislative acts, safety, which lead to injuries and deaths. And to analyse the statistics of industrial injuries in Ukraine. Conclusions. The analysis revealed that a significant part of the injuries and deaths of people is caused by the operations and maintenance of buildings and structures, violations by enterprise owners of regulatory and legislative acts on labor protection, safety, and sanitary and hygienic working conditions. Also, at the enterprises of Ukraine, work is carried out on worn-out technological equipment, which leads to serious consequences in the form of fatal injuries.

Determination of the limiting step in the biomineralization of calcium carbonate by Bacillus cereus

Cement is the most widely used material in the world. However, a lack of maintenance of concrete structures increases the collapse danger. Against this situation, studies to recover structures are developed using biomineralizing bacteria. The aim of this study was to determine the limiting step in a prototype Cascade System for Biomineralization in Cement (CSBC) comparing crystallization to biochemical reaction by Bacillus cereus. The similar conditions of crystallization and bioreaction indicated that crystallization is the limiting step, with a carbonate production rate of 0.19 mg/h. The results obtained indicated an eco-friendly option to reduce greenhouse gas emissions.

Contribution of the LAC Genes in Fruit Quality Attributes of the Fruit-Bearing Plants: A Comprehensive Review

Laccase genes produce laccase enzymes that play a crucial role in the production of lignin and oxidation reactions within plants. Lignin is a complex polymer that provides structure and toughness to the cell walls of numerous fruit plants. The LAC genes that encode laccase enzymes play vital roles in plant physiology, including the synthesis of pigments like PA that contribute to the colors of fruits, and in defending against pathogens and environmental stresses. They are crucial for fruit development, ripening, structural maintenance in plants, and adaptation to various environmental factors. As such, these genes and enzymes are essential for plant growth and development, as well as for various biotechnological applications in environmental remediation and industrial processes. This review article emphasizes the significance of genes encoding laccase enzymes during fruit growth, specifically pertaining to the strengthening of the endocarp through lignification. This process is crucial for ensuring fruit defense and optimizing seed scattering. The information gathered in this article will aid breeders in producing future fruit-bearing plants that are resistant to disease, cost-effective, and nutrient-rich.

Optimization of plastic polymers for shellfish aquaculture infrastructures: in situ antifouling performance assessment

Biofouling poses a significant challenge to bivalve aquaculture affecting both the target culture and/or the immersed infrastructure. In suspended bivalve cultures (e.g., oysters and scallops), biofouling accumulation leads to additional labor demands and increased costs for the maintenance of underwater structures. Given that the inherent properties of materials used in farming infrastructure influence the formation of fouling communities, evaluating how these materials perform under diverse environmental conditions can help the industry select the most effective materials for preventing or minimizing biofouling growth. This study evaluates the impact of aquaculture material and environmental conditions on biofouling, focusing on two commonly used plastic polymers in marine aquaculture: polyamide (PA) and high-density polyethylene (PE). Both untreated and color-additive treated polymers were tested for their response to fouling development. Performance was gauged by total fouling wet weight and the extent of fouling-induced mesh occlusion. Experimental panels were deployed for 4 months (from May to September 2021) in estuarine (oyster farm) and marine (port) environments on the northern coast of Portugal. The marine sites exhibited greater fouling species diversity, while higher biofouling loads were found in the subtidal estuarine area. Within 3 months, complete mesh occlusion occurred mainly due to colonial hydroids (Obelia dichotoma) in the subtidal site. In contrast, panels deployed in the intertidal estuarine area had lower fouling biomass and mesh occlusion. Notably, significant differences between polymer types and treatments were only evident in the estuarine intertidal area, with long air exposure during low tide. White panels outperformed orange ones in fouling biomass, and PA panels outperformed PE panels in mesh occlusion. These differences were attributed to the settlement and growth of the acorn barnacle Austrominius modestus, known to favor dark-colored and less hydrophilic surfaces. Considering that oyster production in intertidal areas is one of the most important aquaculture industries globally, these findings offer valuable insights into material selection and characteristics that can mitigate fouling loads and their associated impacts. These results could also be relevant for other forms of bivalve aquaculture where infrastructure-related biofouling presents a challenge.