Study of Intelligent Approaches to Identify Impact of Environmental Temperature on Ultrasonic GWs Based SHM:A Review

Structural health monitoring(SHM)is considered an effective approach to analyze the efficient working of several mechanical components.For this purpose,ultrasonic guided waves can cover long-distance and assess large infrastructures in just a single test using a small number of transducers.However,the working of the SHM mechanism can be affected by some sources of variations(i.e.,environmental).To improve the final results of ultrasonic guided wave inspections,it is necessary to highlight and attenuate these environmental variations.The loading parameters,temperature and humidity have been recognized as the core environmental sources of variations that affect the SHM sensing mechanism.Environmental temperature has the most significant influence on SHM results.There is still a need for extensive research to develop such a damage inspection approach that should be insensitive to environmental temperature variations.In this framework,the current research study will not only illuminate the effect of environmental temperature through different intelligent approaches but also suggest the standard mechanism to attenuate it in actual ultrasonic guided wave based SHM.Hence,the work presented in this article addresses one of the open research challenges that are the identification of the effect of environmental and operating conditions in practical applications of ultrasonic guided waves and impedance-based SHM.

Core-Excited Molecules by Resonant Intense X-Ray Pulses Involving Electron-Rotation Coupling

It has been reported that electron-rotation coupling plays a significant role in diatomic nuclear dynamics induced by intense VUV pulses [Phys. Rev. A 102(2020) 033114;Phys. Rev. Res. 2(2020) 043348]. As a further step, we present here investigations of the electron-rotation coupling effect in the presence of Auger decay channel for core-excited molecules, based on theoretical modeling of the total electron yield(TEY), resonant Auger scattering(RAS) and x-ray absorption spectra(XAS) for two showcases of CO and CH^(+) molecules excited by resonant intense x-ray pulses. The Wigner D-functions and the universal transition dipole operators are introduced to include the electron-rotation coupling for the core-excitation process. It is shown that with the pulse intensity up to 10^(16) W/cm^(2), no sufficient influence of the electron-rotation coupling on the TEY and RAS spectra can be observed. This can be explained by a suppression of the induced electron-rotation dynamics due to the fast Auger decay channel, which does not allow for effective Rabi cycling even at extreme field intensities,contrary to transitions in optical or VUV range. For the case of XAS, however, relative errors of about 10% and 30% are observed for the case of CO and CH^(+), respectively, when the electron-rotation coupling is neglected.It is concluded that conventional treatment of the photoexcitation, neglecting the electron-rotation coupling,can be safely and efficiently employed to study dynamics at the x-ray transitions by means of electron emission spectroscopy, yet the approximation breaks down for nonlinear processes as stimulated emission, especially for systems with light atoms.

Experimental Investigation of Performance Characteristics of PZT-5A with Application to Fault Diagnosis

In the previous couple of decades,techniques to reap energy and empower low voltage electronic devices have received outstanding attention.Most of the methods based on the piezoelectric effect to harvest the energy from ambient vibrations have been revolutionized.There’s an absence of experiment-based investigation which incorporates the microstructure analysis and crystal morphology of those energy harvest home materials.Moreover,the impact of variable mechanical and thermal load conditions has seldom been studied within the previous literature to utilize the effectiveness of those materials in several practical applications like structural health monitoring(SHM),etc.In the proposed research work,scanning electron microscope(SEM)and energy dispersive x-ray(EDX)analysis are performed to examine the inside crystal morphology of PZT-5A and ensure the quality of the piezoelectric ceramic.Further,the performance of piezoelectric vibration-based energy harvester has been investigated in the second phase of current research work under the variable mechanical and thermal load conditions through a regular series of experiments.It’s been found that the output voltage of piezoelectric sensors will increase by increasing the applied load,whereas a decreasing trend in output voltage is noticed by increasing the applied temperature,resistance and frequency.Within the third part,a measuring setup is developed in the laboratory to further investigate the effectiveness of PZT-5A in practical applications such as electromechanical impedance(EMI)based structural health monitoring under the controlled heating environment.Therefore,this analysis not only evaluates the performance of PZT sensors under the variable operating conditions but also encourages developing a temperature compensation approach in EMI-based SHM.

A Study on Technological Dynamics in Structural Health Monitoring Using Intelligent Fault Diagnosis Techniques:A Patent-Based Approach

The performance and reliability of structural components are greatly influenced by the presence of any abnormality in them.To this purpose,structural health monitoring(SHM)is recognized as a necessary tool to ensure the safety precautions and efficiency of both mechanical and civil infrastructures.Till now,most of the previous work has emphasized the functioning of several SHM techniques and systematic changes in SHM execution.However,there exist insufficient data in the literature regarding the patent-based technological developments in the SHM research domain which might be a useful source of detailed information for worldwide research institutes.To address this research gap,a method based on the Co-Operative Patent Classification(CPC)codes is proposed in the current study.The proposed method includes the patent analysis of SHM in terms of its global publication trend and technology-based applications.This analysis is performed using patent database search tools,namely,IncoPat and Espacenet.The period ranging from 2005 to 2019 is selected to retrieve the required patent documents.A new approach termed as Patents’value is utilized to investigate the technological impact of a patent in the form of forward citations,technical stability,and scope of protection.The identification of emerging SHM techniques and forecasting of vacant technology is also part of current research work.The research results have revealed the increasing trend in the number of published patents each year related to various SHM technologies.In this regard,China,the United States,and South Korea are notified as to the major depositor countries,respectively.Hence,mapping of patent data in this research is an effort to illustrate the effectiveness of the proposed method to demonstrate the development trends and dynamic inventions over the time in SHM research domain to achieve the optimal damage inspections of various mechanical components.

TiO_2/Schwertmannite nanocomposites as superior co-catalysts in heterogeneous photo-Fenton process

The heterogeneous photo-Fenton reaction is an effective technique in combating organic contaminants for both soil and water remediation,and extensive studies have focused on enhancing its efficiency and reducing its costs.In this work,we developed novel photoFenton catalysts by simply milling commercially available TiO_2(P25)with Schwertmannite(Sh),a natural iron-oxyhydroxysulfate nanomineral.We expect that the photo-generated electrons from TiO_2could continuously migrate to Sh,which then could enhance the separation of electron-hole pairs on TiO_2and accelerate the reduction of Fe(III)to Fe(II)on Sh,leading to high degradation efficiency of the target organic contaminants.SEM and TEM results showed the distribution of TiO_2on Sh surface for the nanocomposites(TiO_2/Sh).Under simulated sunlight irradiation,the much higher content of Fe(II)was determined on TiO_2/Sh than on Sh via a common method in the iron ore,and the consumption of H_2O_2and the production of·OH were more significant in the TiO_2/Sh system than those in the TiO_2and Sh systems.These results well support our hypothesis that the photo-generated electrons could migrate from TiO_2to Sh on the composites,and can also explain the much higher degradation efficiency of Rhodamine B(RhB)in the TiO_2/Sh system.Besides,TiO_2/Sh had lower Fe dissolution as compared with Sh,and retained high catalytic stability after four repeated cycles.Above merits of the TiO_2/Sh composites,in combining with their simple synthesis method and low-cost property,indicated that they should have promising applications as heterogeneous photo-Fenton catalysts.

The emerging roles of the DDX41 protein in immunity and diseases

RNA helicases are involved in almost every aspect of RNA, from transcription to RNA decay. DExD/H-box hell- cases compdse the largest SF2 helicase superfamily, which are characterized by two conserved RecA-like domains. In recent years, an increasing number of unexpected functions of these proteins have been discovered. They play important roles not only in innate immune response but also in diseases like cancers and chronic hepatitis C. In this review, we summarize the recant literatures on one member of the SF2 superfamily, the DEAD- box protein DDX41. After bacterial or viral infection, DNA or cyclic-di-GMP is released to cells. After phosphorylation of Tyr414 by BTK kinase, DDX41 will act as a sensor to recognize the invaders, followed by induction of type I interferons （IFN）. After the immune response, DDX41 is degraded by the E3 ligase TRIM21, using Lys9 and Lys115 of DDX41 as the ubiquitination sites. Besides the roles in Innate immunity, DDX41 is also related to diseases. An increasing number of both inherited and acquired mutetions in DDX41 gane are identified from myelodysplastic syndrome and/or acute myeloid leukemia （MDS/AML） patients. The review focuses on DDX41, as well as its homolog Abstrakt in Drosophila, which is important for survlval at all stages throughout the life cycle of the fly.

Interaction of polyhydroxy fullerenes with ferrihydrite：adsorption and aggregation

The rapid development of nanoscience and nanotechnology, with thousands types of nanomaterials being produced, will lead to various environmental impacts. Thus,understanding the behaviors and fate of these nanomaterials is essential. This study focused on the interaction between polyhydroxy fullerenes（PHF） and ferrihydrite（Fh）, a widespread iron（oxyhydr）oxide nanomineral and geosorbent. Our results showed that PHF were effectively adsorbed by Fh. The adsorption isotherm fitted the D-R model well, with an adsorption capacity of 67.1 mg/g. The adsorption mean free energy of 10.72 k J/mol suggested that PHF were chemisorbed on Fh. An increase in the solution p H and a decrease of the Fh surface zeta potential were observed after the adsorption of PHF on Fh; moreover, increasing initial solution p H led to a reduction of adsorption. The Fourier transform infrared spectra detected a red shift of C–O stretching from 1075 to 1062 cm-1 and a decrease of Fe–O bending, implying the interaction between PHF oxygenic functional groups and Fh surface hydroxyls. On the other hand, PHF affected the aggregation and reactivity of Fh by changing its surface physicochemical properties. Aggregation of PHF and Fh with individual particle sizes increasing from 2 nm to larger than 5 nm was measured by atomic force microscopy. The uniform distribution of C and Fe suggested that the aggregates of Fh were possibly bridged by PHF. Our results indicated that the interaction between PHF and Fh could evidently influence the migration of PHF, as well as the aggregation and reactivity of Fh.

Ferritin nanoparticle-based SARS-CoV-2 RBD vaccine induces a persistent antibody response and long-term memory in mice

To date,the global coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has resulted in more than 90 million people infected and over 2 million deaths.A safe and effective vaccine is in high demand.For an effective vaccine,antibody persistence and longterm memory are favorable features.

Synthesis of novel substituted N-aryl benzamides as hA3G stabilizers and their inhibitory activities against hepatitis C virus replication

A series of novel amino-substituted N-aryl benzamide analogs were synthesized and evaluated for their ability to inhibit hepatitis C virus(HCV)replication in acutely infected Huh7.5 cells.Most of the substituted N-aryl benzamide compounds showed convincing anti-HCV activities.Compounds 1f,1g and 4c exhibited potent anti-replicative activity at low micromolar levels(IC_(50)=1.0–2.0μM)with selective indices(SI)greater than 40.Mechanistic analysis indicated that the active compounds increased intracellular hA3G protein levels and inhibited HCV replication in a dose-dependent manner.The results demonstrate that this series of substituted Naryl benzamide compounds warrant further investigation as inhibitors of HCV replication.

Recent advances in the diversification of chromones and flavones by direct C-H bond activation or functionalization

Chromone and flavone are both central backbones of natural products and clinical medicines.Synthesis of diversely functionalized chromones and flavones constitutes significant research contents of the modern synthetic science because abundant molecular libraries of such types are crucial in providing candidate compounds for the discovery of new pharmaceuticals and functional materials.The direct C—H bond activation or functionalization on these heterocyclic backbones provides highly powerful tools for the rapid accesses to densely functionalized chromone and flavone derivatives.Considering the importance of the functionalized chromone and flavone compounds as well as the notable advances in the synthesis of such products by direct C—H activation or functionalization,we review herein the research advances in the C—H bond activation and functionalization reactions of chro mone and flavones,in hope of showing the current states and promise of the research domain.

Post-translational O-GlcNAcylation is essential for nuclear pore integrity and maintenance of the pore selectivity filter

O-glycosylation of the nuclear pore complex(NPC)by O-linked N-acetylglucosamine(O-GlcNAc)is conserved within metazoans.Many nucleoporins(Nups)comprising the NPC are constitutively O-GlcNAcylated,but the functional role of this modification remains enigmatic.Weshowthat loss ofO-GlcNAc,induced by either inhibition ofO-GlcNAc transferase(OGT)or deletion of the gene encoding OGT,leads to decreased cellular levels of a number of natively O-GlcNAcylated Nups.Loss of O-GlcNAc enables increased ubiquitination of these Nups and their increased proteasomal degradation.The decreased half-life of these deglycosylated Nups manifests in their gradual loss from the NPC and a downstream malfunction of the nuclear pore selective permeability barrier in both dividing and post-mitotic cells.These findings define a critical role of O-GlcNAc modification of the NPC in maintaining its composition and the function of the selectivity filter.The results implicate NPC glycosylation as a regulator of NPC function and reveal the role of conserved glycosylation of the NPC among metazoans.

Field validation of UHPC layer in negative moment region of steel-concrete composite continuous girder bridge

Improving the cracking resistance of steel-normal concrete(NC)composite beams in the negative moment region is one of the main tasks in designing continuous composite beam(CCB)bridges due to the low tensile strength of the NC deck at pier supports.This study proposed an innovative structural configuration for the negative bending moment region in a steel-concrete CCB bridge with the aid of ultrahigh performance concrete(UHPC)layer.In order to investigate the feasibility and effectiveness of this new UHPC jointed structure in the negative bending moment region,field load testing was conducted on a newly built full-scale bridge.The newly designed structural configuration was described in detail regarding the structural characteristics(cracking resistance,economy,durability,and constructability).In the field investigation,strains on the surface of the concrete bridge deck,rebar,and steel beam in the negative bending moment region,as well as mid-span deflection,were measured under different load cases.Also,a finite element model for the four-span superstructure of the full-scale bridge was established and validated by the field test results.The simulated results in terms of strains and mid-span deflection showed moderate consistency with the test results.This field test and the finite element model results demonstrated that the new configuration with the UHPC layer provided an effective alternative for the negative bending moment region of the composite beam.

Structural and functional analyses of human DDX41 DEAD domain

Dear Editor, DEAD-box proteins, which are named after the strictly con- served amino acid sequence Asp-Glu-Ala-Asp, were first identified as a distinct family in the late 1980s when alignments based on eight homologues of the yeast elF4A highlighted the presence of several conserved motifs （Linder et al., 1989）.