Abstract
Damage mechanism identification has scientific and practical ramifications for the structural health monitoring, design, and application of composite systems. Recent advances in machine ...learning uncover pathways to identify the waveform-damage mechanism relationship in higher-dimensional spaces for a comprehensive understanding of damage evolution. This review evaluates the state of the field, beginning with a physics-based understanding of acoustic emission waveform feature extraction, followed by a detailed overview of waveform clustering, labeling, and error analysis strategies. Fundamental requirements for damage mechanism identification in any machine learning framework, including those currently in use, under development, and yet to be explored, are discussed.
Copper is essential for the stability and activity of cytochrome
oxidase (CcO), the terminal enzyme of the mitochondrial respiratory chain. Copper is bound to COX1 and COX2, two core subunits of CcO, ...forming the Cu
and Cu
sites, respectively. Biogenesis of these two copper sites of CcO occurs separately and requires a number of evolutionarily conserved proteins that form the mitochondrial copper delivery pathway. Pathogenic mutations in some of the proteins of the copper delivery pathway, such as SCO1, SCO2, and COA6, have been shown to cause fatal infantile human disorders, highlighting the biomedical significance of understanding copper delivery mechanisms to CcO. While two decades of studies have provided a clearer picture regarding the biochemical roles of SCO1 and SCO2 proteins, some discrepancy exists regarding the function of COA6, the new member of this pathway. Initial genetic and biochemical studies have linked COA6 with copper delivery to COX2 and follow-up structural and functional studies have shown that it is specifically required for the biogenesis of the Cu
site by acting as a disulfide reductase of SCO and COX2 proteins. Its role as a copper metallochaperone has also been proposed. Here, we critically review the recent literature regarding the molecular function of COA6 in Cu
biogenesis.
•High temperature uniaxial loading of un-notched and notched Hastelloy X samples.•High temperature digital image correlation (DIC) measurements of strains fields in both cases.•Identification of PLC ...effect from macroscale load–displacement measurements.•Observation of PLC band strain fields by microscale DIC experiments.•Investigation of PLC strain band origination from notch tips.
The plastic behavior of Hastelloy X subjected to thermo-mechanical loading was investigated in this work, and the phenomenon of dynamic strain aging was studied under isothermal conditions, using digital image correlation (DIC). The material of interest, Hastelloy X a Ni-based superalloy, is widely used in high temperature applications. It was seen that Hastelloy X exhibits serrated plastic flow behavior between temperatures of 300°C and 700°C, as a consequence of the dynamic strain aging effect, which, depending on temperature, manifests as type A/B or A and B oscillations on the uniaxial tension stress–strain curve, and is characterized by strain concentration bands propagating along the length of the specimen. The characteristics of Portevin-Le Chatelier (PLC) band internal strain distribution in uniaxial tension experiments were also investigated. The bands themselves were seen to have internal (sub)bands of two or three smaller strain jumps. An analysis of the strain increments induced by these bands was performed and clearly illustrates the inhomogeneous nature of the deformation – both spatially and temporally. In addition to the uniaxial behavior, biaxial stress states were investigated by studying PLC band formation near a notch in a double notched tensile geometry. Similar macroscopic results to the uniaxial case were seen while the strain bands themselves were seen to initiate in the notch region and travel away from the notches.
This work considers nonsmooth and nonconvex optimization problems whose objective and constraint functions are defined by
difference-of-convex
(DC) functions. We consider an infeasible bundle method ...based on the so-called improvement functions to compute critical points for problems of this class. Our algorithm neither employs penalization techniques nor solves subproblems with linearized constraints. The approach, which encompasses bundle methods for nonlinearly-constrained convex programs, defines trial points as solutions of strongly convex quadratic programs. Different stationarity definitions are investigated, depending on the functions’ structures. The approach is assessed in a class of nonsmooth DC-constrained optimization problems modeling chance-constrained programs.
In the current age of technology, various diseases in the body are also on the rise. Tumours that cause more discomfort in the body are set to increase the discomfort of most patients. Patients ...experience different effects depending on the tumour size and type. Future developments in the medical field are moving towards the development of tools based on IoT devices. These advances will in the future follow special features designed based on multiple machine learning developed by artificial intelligence. In that order, an improved algorithm named Internet of Things-based enhanced machine learning is proposed in this paper. What makes it special is that it involves separate functions to diagnose each type of tumour. It analyzes and calculates things like the size, shape, and location of the tumour. Cure from cancer is determined by the stage at which we find cancer. Early detection of cancer has the potential to cure quickly. At a saturation point, the proposed Internet of Things-based enhanced machine learning model achieved 94.56% of accuracy, 94.12% of precision, 94.98% of recall, 95.12% of F1-score, and 1856 ms of execution time. The simulation is conducted to test the efficacy of the model, and the results of the simulation show that the proposed Internet of Things-based enhanced machine learning obtains a higher rate of intelligence than other methods.
Standardized rapid pulsed-field gel electrophoresis (PFGE) protocols for the subtyping of Escherichia coli O157:H7, Salmonella serotypes, and Shigella species are described. These protocols are used ...by laboratories in PulseNet, a network of state and local health departments, and other public health laboratories that perform real-time PFGE subtyping of these bacterial foodborne pathogens for surveillance and outbreak investigations. Development and standardization of these protocols consisted of a thorough optimization of reagents and reaction conditions to ensure that the protocols yielded consistent results and high-quality PFGE pattern data in all the PulseNet participating laboratories. These rapid PFGE protocols are based on the original 3-4-day standardized procedure developed at Centers for Disease Control and Prevention that was validated in 1996 and 1997 by eight independent laboratories. By using these rapid standardized PFGE protocols, PulseNet laboratories are able to subtype foodborne pathogens in approximately 24 h, allowing for the early detection of foodborne disease case clusters and often aiding in the identification of the source responsible for the infections.
We provide data on daily social contact intensity of clusters of people at different types of Points of Interest (POI) by zip code in Florida and California. This data is obtained by aggregating ...fine-scaled details of interactions of people at the spatial resolution of 10 m, which is then normalized as a social contact index. We also provide the distribution of cluster sizes and average time spent in a cluster by POI type. This data will help researchers perform fine-scaled, privacy-preserving analysis of human interaction patterns to understand the drivers of the COVID-19 epidemic spread and mitigation. Current mobility datasets either provide coarse-level metrics of social distancing, such as radius of gyration at the county or province level, or traffic at a finer scale, neither of which is a direct measure of contacts between people. We use anonymized, de-identified, and privacy-enhanced location-based services (LBS) data from opted-in cell phone apps, suitably reweighted to correct for geographic heterogeneities, and identify clusters of people at non-sensitive public areas to estimate fine-scaled contacts.
Abstract
In this work, we demonstrate that damage mechanism identification from acoustic emission (AE) signals generated in minicomposites with elastically similar constituents is possible. AE ...waveforms were generated by SiC/SiC ceramic matrix minicomposites (CMCs) loaded under uniaxial tension and recorded by four sensors (two models with each model placed at two ends). Signals were encoded with a modified partial power scheme and subsequently partitioned through spectral clustering. Matrix cracking and fiber failure were identified based on the frequency information contained in the AE event they produced, despite the similar constituent elastic properties of the matrix and fiber. Importantly, the resultant identification of AE events closely followed CMC damage chronology, wherein early matrix cracking is later followed by fiber breaks, even though the approach is fully domain-knowledge agnostic. Additionally, the partitions were highly precise across both the model and location of the sensors, and the partitioning was repeatable. The presented approach is promising for CMCs and other composite systems with elastically similar constituents.
Polycondensation of boric acid and vinyltriethoxysilane in 1:2, 1:1.5 and 1:1 mole ratio in diglyme at 83–87 °C for 3 h using hydrochloric acid as catalyst afforded vinylfunctionalized borosiloxane ...oligomers soluble in the reaction medium. Complete removal of ethanol, the by-product, and diglyme rendered the oligomers intractable due to the advancement of polycondensation. They were characterized by FTIR and TGA and converted to ceramics by heat treatment at 900 °C, 1500 °C and 1650 °C in argon atmosphere. The ceramics obtained were characterized by IR, Raman,
13
C-and
29
Si-solid state NMR spectroscopy and XRD. These studies infer the formation of SiOC/SiBOC glass on pyrolysis of these oligomers at 900 °C and onset of formation of β-SiC at 1500 °C. On further heat treatment at 1650 °C, complete conversion of the ceramic to a mixture of α and β-SiC was observed along with the presence of diamond like carbon phases.
Salmonella nomenclature Brenner, F W; Villar, R G; Angulo, F J ...
Journal of clinical microbiology,
07/2000, Letnik:
38, Številka:
7
Journal Article
Recenzirano
Odprti dostop
Salmonella nomenclature is complex, and scientists use different systems to refer to and communicate about this genus. However, uniformity in Salmonella nomenclature is necessary for communication ...between scientists, health officials, and the public. Unfortunately, current usage often combines several nomenclatural systems that inconsistently divide the genus into species, subspecies, subgenera, groups, subgroups, and serotypes (serovars), and this causes confusion. CDC receives many inquiries concerning the appropriate Salmonella nomenclature for the reporting of results and for use in scientific publications. The defining development in Salmonella taxonomy occurred in 1973 when Crosa et al. demonstrated by DNA-DNA hybridization that all serotypes and subgenera I, II, and IV of Salmonella and all serotypes of 'Arizona' were related at the species level; thus, they belonged in a single specie. In 1986 the Subcommittee of Enterobacteriaceae of the International Committee on Systematic Bacteriology at the XIV International Congress of Microbiology unanimously recommended that the type species for Salmonella be changed to S. enterica, a name coined by Kauffmann and Edwards in 1952, because no serotype shares this name. Nonetheless, the request was denied by the Judicial Commission. Although the Judicial Commission was generally in favor of S. enterica as the type species of Salmonella, its members believed that the status of Salmonella serotype Typhi, the causative agent of typhoid fever, was not adequately addressed in this request for an opinion.
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