Damage Process Research Articles

Debonding Fiber Damage Mechanism Modeling for Machining Damage Inhibition During Rotary Ultrasonic Face Grinding SiO2f/SiO2

Abstract The debonding fiber defects on the grinding surface of SiO2f/SiO2 ceramic matrix composites deteriorate the service performance of related components. The low-damage process window is the key information to suppress machining damage by controlling grinding parameters. A mechanism model for debonding fiber damage on SiO2f/SiO2 surface was first proposed in this paper by the large deformation analysis for SiO2 fibers during rotary ultrasonic face grinding (RUFG). The established mechanism model built a bridge between grinding parameters and damage inhibition by integrating the ultrasonic stress effect, grinding force calculation, and critical fracture curvature cutting-off criterion of SiO2 fibers. The modeling mechanism for fiber deformation and fracture in grinding was validated by in situ observation of single abrasive grit scratching experiments. Besides, the low debonding damage process window predicted by the model was verified by experimental results and could be adopted to suppress the debonding fiber damage in grinding. The affected mechanism of fiber orientation, ultrasonic amplitude, and fiber-matrix interface strength on the low debonding damage process window was analyzed based on the theoretical and experimental results. The damage inhibition effect of the RUFG process was limited by the low fiber-matrix interface strength and axial cutter-relieving movement component. The ultrasonic-assisted vibration exerted its auxiliary effects through the ultrasonic stress effect and force reduction effect. The prerequisite for exerting the damage inhibition effect of RUFG was that the fiber-matrix interface strength was sufficient to resist the negative influence of the ultrasonic stress effect.

Damage monitoring of glass/epoxy-curved laminates with different stacking sequences using acoustic emission

Delamination is a major concern in the curvature area of a composite laminate due to the flexural stresses occurring between the laminates. This research focuses on the respective merits of different stacking sequences obtained by layering the glass fiber reinforcement at various orientations in an epoxy resin to manufacture a curved laminate. In particular, laminates with stacking sequences, such as Unidirectional [0°]24, Cross-ply [0°/90°]6S, Angle ply [±45°]6S, and Quasi-isotropic laminates [0°/±45°/90°]3S, were tested by performing four-point bending tests. Acoustic emission (AE) monitoring and experimental analysis characterized damage modes, including delamination. AE parameters, such as amplitude, energy, duration, cumulative count, and peak frequency, were utilized to characterize the damage mechanisms of the various stacking sequences. Experimental AE data confirmed that fiber orientation influences delamination resistance and failure mechanisms. Furthermore, compared to other layup sequences, the peak load of cross-ply (Layup B) was found to be greater by 48.7%, 32.87%, and 50.14%. Cross-ply curved laminates also have higher interlaminar tensile strength and curved beam strength than other sequences. They also failed less often due to delamination than other sequences. Finally, scanning electron microscope characterization verified and validated all damage processes found in the AE data collection. As a result, these findings play a significant role in predicting the lifetime, delamination failure, and strength of curved composite laminates.

Cyclic seismic pushover testing of a multi-story underground station

The experimental approach is crucial for investigating the seismic performance and damage process of underground structures. Considering the shortcomings of the 1-g, centrifuge shaking table and monotonic displacement pushover tests, a large-scale cyclic displacement pushover test method is proposed based on the soil-underground structure dynamic interaction and seismic performance quantification system. Taking a two-story three-span subway station structure as the prototype, the cyclic displacement pushover test device was designed for a 1/7-scale multi-story subway station based on the seismic response characteristics of underground structures. The corresponding numerical simulations and experiments were conducted. Typical numerical results (including the seismic damage process, capacity curves of the structural columns, and strain response) and test results (the macroscopic phenomenon of structural damage development, strain response, and deformation response) are interpreted. The results show that the proposed cyclic displacement pushover test is better than the monotonic displacement pushover test, the damage process of the tested station structure conforms to the description of the inter-story drift ratio (IDR) quantification system of seismic performance. Meanwhile, the column has greater strain amplitudes than other components, and the column strain curves reach their peaks before other components. Furthermore, the tested station structure has a similar damage pattern to the Daikai subway station. The reliability and feasibility of the proposed cyclic displacement pushover test method are verified.

Numerical simulation of heat transfer properties of skin tissue acted on repetitive laser irradiation

Pulsed laser has been widely used in the clinical treatment of various diseases and injuries due to its unique advantages in the process of interaction with skin tissue. In order to ensure the therapeutic effect and patient safety, it is necessary to accurately monitor the time-space response of the whole-field temperature of the target tissue irradiated by pulsed laser. A research strategy to explore the thermal response and incidental thermal damage of skin tissue induced by repeated pulses laser has been proposed in present work. A theoretical model involved variable physical properties was first proposed, in which the dual-phase lag (DPL) equation and Henrique burn equation were employed to evaluate the tissue temperature and thermal damage induced by repeated pulse laser irradiation. With the help of finite difference method, the governing equation with variable physical properties was then numerical solved to obtain the time-space distribution of tissue temperature, and the evolution process of the thermal damage was further calculated. The effects of laser input parameters and variable physical parameters on the laser penetration depth, temperature distribution and burn degree of the irradiated tissue were analyzed.

A first step towards the detection of damage processes in endodontic Ni-Ti alloy files, using acoustic emission

Despite major instrumental developments over the last decade, endodontic files are still not infallible. It is well known that NiTi rotary files can break without any visible sign of deformation. Instrument breakage under combined flexion-torsion loading is still common in clinical practice. Unfortunately, breakage of this type of instrument mainly occurs in narrow canals, through pinching in the apical region. When such an incident occurs, the endodontist must adopt a debris retrieval strategy that is both stressful and not guaranteed success. This study proposes a new method for experimental damage detection leading to the fracture of Ni-Ti shape memory alloy endodontic files. It is based on the acoustic emission (AE) technique and mechanical parameters measured in real-time and image analysis. It has been shown that the AE results correlate with the damage observations and torque and force measurements recorded during the tests.Having carried out numerous root canal treatment on resin blocks, it appears that this new detection and analysis technique can be used to analyze and anticipate the first signs of damage leading to endodontic file failure. The technological development of such a method, at the level of the engine itself, associated with the act in service procedure, would constitute a revolution in the field of endodontics.

Combinatorial protection of cochlear hair cells: not too little but not too much.

A number of drugs are toxic to the cochlear sensory cells known as hair cells (HCs), resulting in hearing loss. Treatment with survival-promoting growth factors, antioxidants, and inhibitors of cell death pathways or proteinases have been shown to reduce HC damage in in vivo and/or in vitro animal models. Conversely, translation to humans has often been disappointing. This may be due to the complexity of intracellular damage processes. We hypothesized that combining treatments targeting different cellular processes would be more effective. Using an in vitro model of gentamicin ototoxicity for murine cochlear hair cells, we screened all 56 possible combinations of inhibitors targeting five different cell damage mechanisms, plus the activator of one cell survival pathway, each of which have been shown to be singly effective in preventing HC loss in experimental studies. A high dose of gentamicin (200 μM) was used over three days in culture. All compounds were added at a dosage below that required for significant protection in the assay, and only this single dose was then employed. This was done so that we could more easily detect interactive, as opposed to additive, effects. Increasing protection of hair cells was observed as combinations of compounds were increased from two to four factors, although not all combinations were equally protective. The optimal combination of four compounds consisted of an anti-oxidant, an apoptosis inhibitor, an autophagy inhibitor and a protective growth factor. Increasing the number of factors to five or six resulted in decreased protection. The results support the hypothesis that targeting multiple cellular damage or survival pathways provides more an effective hair cell protection approach. The results help to identify critical interactions among the cellular processes that operate in gentamicin ototoxicity. They also suggest that inhibiting too many biological processes impairs functions critical to HC survival, resulting in decreased protection.

A study of rock mass properties based on discrete fracture network modeling and compression damage process

A study of rock mass properties based on discrete fracture network modeling and compression damage process

Monitoring of damage evolution in carbon fiber reinforced polymer composites by electrical impedance tomography

Electrical impedance tomography (EIT) has been widely investigated as a nondestructive testing method for carbon fiber reinforced polymer (CFRP) composites. However, the performance of EIT method on the damage process monitoring of the composites is lack of investigation. Herein, quasi-static indentation tests were utilized to introduce damage on CFRP laminates. The damage evolution process was monitored by EIT, while the potential of distinguishing the elastic deformation stage from the plastic stage was analyzed with the aid of acoustic emission. It was found that the changes in conductivity first appeared in the non-central region. With the accumulation of damage, the conductivity changes gradually extended to the center region. The reconstructed damage images were in the crossover shape, which was consist with the micro-CT results that showed the fracture of fibers in ±45° direction. This work further promotes the application of EIT in damage process monitoring of CFRP components.

Abstract C028: Challenging PDAC adaptability: Uncovering therapeutic vulnerabilities in APE1 DNA repair mechanisms

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a therapeutically challenging malignancy notorious for its resilience to therapeutic strategies and ability to thrive under extreme conditions. The cancer's inherent ability to adaptively resist treatments underscores the need for novel and combinatorial therapeutic approaches. Our research focuses on elucidating the role of Apurinic-apyrimidinic endonuclease/Redox effector factor 1 (APE1/Ref-1), a critical multifunctional protein in PDAC pathobiology. APE1 serves two essential functions: as the principal endonuclease in the base excision repair (BER) pathway for DNA repair and as a redox regulator of transcription factors essential for cancer cell proliferation. While the therapeutic targeting of APE1’s redox function has been effective and continues to yield significant advances, the development of treatments aimed at its DNA repair function has proven more challenging with comparatively limited progress. Since standard PDAC treatment regimens involve DNA damaging agents potentially repaired via BER and APE1, we engineered three mutant cell lines with knock-in mutations resulting in a reduction of APE1’s BER activity while maintaining full redox activity. Biochemical evaluations confirmed the effects of the mutation, revealing a 30-fold reduction in DNA repair capacity. Surprisingly, with respect to growth and proliferation, the mutant and wild-type cell lines behaved similarly. Analyses of cytotoxic vulnerabilities revealed similar findings with the mutant lines exhibiting minimal phenotypic differences in sensitivity when challenged with cytotoxic and DNA damaging agents in proliferation-based assays. These findings led us to posit that the mutant cell lines were relying on compensatory DNA repair pathways which were providing sufficient compensation for the decrease in APE1 activity. We further hypothesized that the cell lines may still have hidden, long-term deficiencies in DNA damage processing which are not apparent during the initial stress response. Subsequent colony formation assays revealed that the mutant cell lines do exhibit poor long-term survival even after only short-term exposure to DNA damage. In vivo orthotopic mouse model experiments further corroborated these findings, showing a significant reduction in tumor size and decreased metastasis to the lungs and liver in mutant cell lines compared to wild-type controls. While APE1 is the primary endonuclease in the BER pathway, studies have demonstrated APE1-independent BER in rare, specific contexts. We are probing the hypothesis that these APE1-independent BER pathways function as the compensatory mechanism safeguarding these cells in short-term stress situations. Identifying and characterizing these backup pathways will not only offer a better understanding of APE1’s DNA repair capabilities within PDAC but will also provide a better understanding of how DNA repair mechanisms can be therapeutically targeted for novel therapeutic options or combinations. This opens the path to enhance standard of care treatments such as FOLFIRINOX. Citation Format: Eyram K Kpenu, Randall Wireman, Mahmut Mijiti, Silpa Gampala, Melissa L Fishel, Mark R Kelley. Challenging PDAC adaptability: Uncovering therapeutic vulnerabilities in APE1 DNA repair mechanisms [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C028.

Shrinkage cracking law and anti-crack inverse design in early-age concrete: A novel perspective on the development of crack resistance properties

Early-age cracking in massive concrete has long attracted research focus, essentially governed by the game between crack driving and resistance. However, cracking resistance aspect received inadequate attention. This study examines the impact of crack resistance properties development processes on shrinkage cracking law in early-age concrete, employing chemo-thermo-mechanical coupling phase-field model. Two quantitative evaluation indicators, namely the index of damage development and average growth rate of maximum damage, are introduced to characterize the process of damage and cracking. The findings demonstrate that the development processes of elastic modulus and tensile strength exert a considerable influence on shrinkage cracking process in early-age concrete, whereas the impact of fracture energy development process is insignificant. Multifactor analysis revealed substantial coupling effects among parameters. Additionally, an anti-crack reverse design method is proposed based on the global optimization analysis, which can guide the optimization design of shrinkage crack prevention and control in early-age concrete from both perspectives of crack driving and crack resistance.

Seismic Performance Analysis of the Internal Joint in the New Demountable Fabricated Concrete Frame with Prestressed Mortise–Tenon Connections

This paper proposed a novel demountable fabricated joint in frame, which is connected by the prestressed and mortise–tenon connection. The prefabricated components of the demountable structures are designed to be reused, and the joint presented in this paper will promote the sustainable application of prefabricated components in future. The damage process and damage pattern of the internal joints under the horizontal load were analyzed using the refined numerical analysis model based on ABAQUS 6.14. Parametric analyses were conducted simultaneously for five parameters: axial compression ratio, the area and effective initial stress of unbonded prestressed strands (UPSs), the local reinforcement ratio in the core zone of the demountable joint, and the friction coefficient between the interface of concrete. The results showed that the demountable joint exhibits excellent energy dissipation potential under horizontal loads, but the damage was concentrated in the core zone. The deformation of the joint mainly consisted of the self-deformation of the prefabricated components, including bending, bearing and shear, as well as the relative slip deformation between the prefabricated components. The axial compression ratio has a more significant effect on the hysteresis performance compared to the areas of the UPSs and the reinforcement ratio. The initial effective stress of the UPS and the friction coefficient have relatively minor influence on the hysteretic performance of the joint. Finally, this paper recommends the design parameter values (axial compression ratio should not exceed 0.4, area of unbonded prestressed reinforcement should be not lower than Asn=0.02 and not higher than Asn=0.1, the initial stress of the UPS takes the value of 0.75fpu) and outlines optimization measures.

Investigation into diffusion behaviours of moisture in asphalt film using Fourier transform infrared spectroscopy

ABSTRACT To reveal the moisture damage mechanism of asphalt pavement and clarify the process of moisture damage to asphalt films, the diffusion behaviours of moisture in asphalt films were analysed. The findings indicate that during the first stage of the water bath process, the moisture diffusion coefficient in asphalt films is considerable and the diffusion rate is rapid. As the moisture diffusion rate increases, the free moisture content in asphalt films tends to saturate. Subsequently, partial free moisture transitions into bound moisture results in a decline in the diffusion coefficient of asphalt films and a reduction in its moisture absorption rate. As the temperature rises, the moisture diffusion coefficient in asphalt film and the maximum saturation amount of moisture that can be absorbed by asphalt films increase. The moisture diffusion behaviour is not readily discernible at a low temperature. The diffusion coefficients of moisture in unmodified asphalt films in the two stages are higher than those in modified asphalt films. The first stage of moisture diffusion in unmodified asphalt films occurs at a faster rate than in modified asphalt films. It is further verified that unmodified asphalt is more subjected to moisture damage.

Analysis of dynamic disturbance and multistage shear creep damage evolution law of the weak intercalated layers in slope under the influence of coupled damage effect

Based on the damage characteristics of multistage shear creep in weak intercalated layers (carbonaceous mud shale) of slopes under the influence of dynamic disturbance, the effective bearing area method was used. A new coupled damage equation (dynamic disturbance damage, shear creep damage, and initial damage) was established through further derivation, and its applicability was demonstrated. The calculation method for the relevant coupled damage degrees was also provided. Furthermore, by targeting the three coupled damage factors and extending the Kachanov damage law, a time-dependent damage evolution equation for weak intercalated layers under the influence of the three coupled damage effects was established. The influence of different dynamic disturbance intensities on the evolution of multistage shear creep damage in weak intercalated layers of slopes under the influence of coupled damage effects was analysed. The results show that the damage to the rock mass caused by dynamic disturbance mainly occurs in the low-frequency stage (40–80 Hz). The instantaneous damage caused by dynamic disturbance to the shear plane of weak intercalated layers is not only affected by the intensity of the dynamic disturbance but also limited by the magnitude of the shear creep load. The influence of the dynamic disturbance intensity on the entire process of multistage shear creep damage of weak intercalated layers was analysed. With increasing of dynamic disturbance intensity, the cumulative coupled damage at the end of shear creep at all levels gradually exhibits linear evolution. The time-dependent coupling damage evolution process of weak intercalated layers was quantitatively characterized.

Mechanical behaviors of metakaolin-based foamed geopolymer (MKFG) under dynamics loading

In this study, metakaolin-based foam geopolymer (MKFG) with densities of 400 kg/m3, 600 kg/m3, and 800 kg/m3 were prepared. The effect of weak links on the dynamic mechanical behavior, damage morphology, and energy absorption capacity (SEAp) of the MKFG was studied by X-CT analysis, Split Hopkinson Pressure Bar (SHPB) test, and fractal analysis. The results show that the connected porosity of MKFG rises with decreasing density. The sensitivity of the damage level to strain rate decreases with elevated connected porosity, which is because the stress concentrations caused by weak links. The amplifying effect of strain rate on the dynamic compressive strength of MKFG diminishes as the connected porosity increases. The sensitivity of SEAp to the damage level rises with a decrease in the connected porosity. Finally, the simulation results corroborate that the distribution of connected pores has a significant influence on the damage process of the MKFG.

Seismic response and damage evolution process of a bedded slope‒tunnel system via the continuum‒discontinuum element method

To investigate the failure evolution process and failure mechanism of the bedded slope‒tunnel system under earthquakes, this work examines a specific layered slope at a tunnel portal in southeast China and conducts a 2D dynamic analysis with the continuum‒discontinuum element method (CDEM). It investigates the slope's dynamic behavior and potential for instability by evaluating the wave patterns, acceleration, displacement, Hilbert‒Huang transform (HHT) spectral analysis, and equivalent crack ratio. The research results indicate that the analysis of acceleration and displacement over time provides insights into wave propagation within a slope. During minor earthquakes (< 0.3 g), the slope experiences dynamic amplification at the surface and elevation-dependent effects, which are less evident during stronger seismic events. This work also revealed a positive correlation between the tunnel's dynamic amplification and elevation. A method leveraging HHT energy analysis, in conjunction with the slope's equivalent fracture ratio, is introduced to trace the progression of seismic damage across temporal and spatial dimensions. The progression of seismic intensity is characterized by stages of local failure initiation, expansion, and eventual holistic failure. Similarly, the temporal dynamics of instability are categorized into phases of initial instability, acceleration, and eventual sliding. Furthermore, this work explores the impact of tunnels on slope stability by comparing the equivalent fracture ratios and dynamic displacement patterns of slopes both with and without tunnels, revealing the evolution process of seismic damage to slope‒tunnel systems. This work provides a reference for the seismic design of complex slope‒tunnel systems.

Post-disaster damage and loss assessment in the Iranian healthcare sector: a qualitative interview study

BackgroundAccurate post-disaster damage and loss assessment is critical for the success of subsequent recovery programs. A comprehensive and systematic damage and loss assessment process involves evaluating the physical damage and financial impact of an event on individuals, communities, and assets. To ensure effective recovery, the various components and entities included in the program must be developed appropriately and efficiently. This study aimed to identify the components and entities of the Iranian healthcare sector’s post-disaster damage and loss assessment program.MethodsA qualitative study employing purposive sampling and semi-structured individual interviews was conducted with 18 participants between October 2022 and July 2023, with continuing until data saturation was achieved. Data collection involved semi-structured interviews and observational notes with experts, including representatives from the National Disaster Management Organization (NDMO), the Iranian Red Crescent Society, and the Disaster Risk Management Department of the Ministry of Health and Medical Sciences Universities. The interviews were conducted in the workplace of the participants. Thematic analysis, a conventional qualitative method, was employed for the analysis of the data. Following the transcription of the recorded interviews, the initial codes were extracted, reviewed for accuracy, and classified.ResultsThe results of this study are based on the insights and experiences of a diverse group of qualified experts in their respective fields. The findings were analysed and classification into ten main themes, 29 sub-themes, and 1,058 codes. The main themes were key concepts and principles of assessment; assessment stages; health system measures in assessment; roles and responsibilities; team composition; information and communication; coordination and collaboration; data collection and analysis; assessment tools and methods; and reporting, documentation, and recommendations.ConclusionAn understanding of key concepts and principles enables stakeholders to respond effectively to disasters, make informed decisions, and facilitate recovery and reconstruction efforts.

Effect of combined parametric impacts on collapsing the wall quality of WAAM Al5356 component

Even though Wire and Arc Additive Manufacturing (WAAM) of the Al5356 component has garnered attention for making affordable, large-scale components, problems with porosity, humping, and undercut still exist. Therefore, optimising process parameters is crucial to achieving flawless products with consistent layer deposition. Hence in this research, the most important WAAM parameters including travel speed (TS), wire feed speed (WFS), and torch angle (TA), were examined in order to determine how they affected structural integrity while taking into account key responses such as porosity, pore diameter, and tensile strength. The Significance of Criteria Weighted Aggregated Sum Product Assessment (WASPAS) in conjunction with Intercriteria Correlation (CRITIC) was used to investigate the favourable circumstances and confirm that the TA is the most important parameter in the nucleation of pores. The verification studies demonstrate that a 58.2 % reduction in pore diameter results in a 31.8 % increase in tensile strength. An ideal TS and WFS of 65 cm/min and 5 m/min, with a maximum TA of 90°, were found to be the favorable conditions for printing Al5356 wall with a minimum porosity of 0.037 %, enhanced ultimate tensile strength of 278 MPa, and minimum pore diameter of 93 µm, according to the CRITIC associated WASPAS approach. Additionally, using the fractography, the damage process based on the porosity creation was investigated. The optimal parameters for generating a defect-free multi-layer structure were identified, hence enhancing the structure’s suitability for industrial use.

TECHNOLOGICAL COMPLICATIONS (FORMATION DAMAGE) DURING CO2 INJECTION FOR ENHANCED OIL RECOVERY. Part 2. INTERACTION OF CO2 WITH FORMATION OIL: WETTABILITY CHANGE, ASPHALTENE PRECIPITATION AND DEPOSITION IN THE FORMATION

In the second part of the review (the first part was published in [1]) the processes of formation damage at CO2 injection due to the oil phase stability disturbance are considered. Changes in reservoir temperature, pressure or fluid composition due to CO2 dissolution can provoke asphaltene precipitation and deposition. Their adsorption on the reservoir pore surface leads to a change in decrease in rock permeability. The currently ac wettability and a cepted numerical models describe well the experimental results on colmatation of pore media by asphaltenes in the presence of CO2, with different equations for asphaltene adsorption and kinetics of their occurrence being used in the models. Asphaltenes precipitated in pore volumes migrate with formation fluids to production wells and can form deposits that complicate oil production.

Transcriptomic analysis reveals the mechanism of isorhamnetin in the treatment of diabetes mellitus erectile dysfunction

PurposeExploring the therapeutic effect and mechanism of isorhamnetin in the treatment of DMED. MethodsUsing a high glucose environment to induce endothelial cells damage in the corpus cavernosum, and combining with intervention agents such as ferroptosis inhibitors to observe the process of cell damage and repair, evaluating cell status through CCK-8 and DAPI; To establish the STZ-induced diabetes rat model and detect the erectile function and tissue changes; Perform transcriptomic sequencing on rat models and samples treated with isorhamnetin to analyze differentially expressed genes and their GO functions; Identify critical pathways by combining with the ferroptosis database; Flow cytometry was used to detect ROS and mitochondrial membrane potential, and RT-PCR was used to verify gene expression, Seahorse detects mitochondrial oxygen consumption rate, revealing the mechanism of action of isorhamnetin. ResultsFerroptosis inhibitors and isorhamnetin can effectively reverse the damage of corpus cavernosum endothelial cells induced by high glucose and ferroptosis agonists. Isorhamnetin has the ability to reinstate the erectile function of diabetic rats, while enhancing the quantity of endothelial cells and refining the morphology of collagen fibers. Immunohistochemistry revealed that ferroptosis existed in the penis tissue of diabetes rats. Transcriptomic analysis showed that isorhamnetin improves gene expression in DM rats by regulating genes such as GFER, IGHM, GPX4 and HMOX1, involving multiple pathways and biological processes. Flow cytometry and RT-PCR confirmed that isorhamnetin can reduce reactive oxygen species levels, restore essential gene expression, improve mitochondrial membrane potential, and alleviate oxidative stress and ferroptosis. Seahorse detection found that isorhamnetin can restore mitochondrial oxygen consumption rate. ConclusionIsorhamnetin attenuates high glucose damage to cavernous endothelial cells by inhibiting ferroptosis and oxidative stress, restores erectile function and improves tissue morphology in diabetic rats, and its multi-pathway and multi-targeting regulatory mechanism suggests that it is promising to be an effective drug for the treatment of DMED.

Properties of W–Ta Materials of the Neutron-Producing Target of the Subcritical Assembly at the National Scientific Centre ‘Kharkiv Institute of Physics and Technology’ of the National Academy of Sciences of Ukraine

The works in the field of radiation materials science of target materials of neutron sources based on the subcritical assemblies controlled by linear accelerators of electrons or protons, so-called accelerator driven systems (ADS), are reviewed. Now, electronuclear ADS systems are the prototype of safe nuclear reactors of the 5th generation. In connection with the physical start-up of the neutron source facility of the National Scientific Centre ‘Kharkiv Institute of Physics and Technology’ of the N.A.S. of Ukraine (NSC ‘KhIPT’ NASU), the target of which is fabricated from powdered tungsten covered with tantalum, the issues of preparation technology, construction, and physical and mechanical properties of W–Ta materials of targets in non-irradiated and irradiated states are considered. The nuclear-physical processes of radiation damage to the target during co-irradiation of it with both neutrons of a subcritical assembly and high-energy e- and γ-beams are analyzed. The target resources of ADS systems are estimated. As noted, the difficulty of predicting the ‘survivability’ of the W–Ta target also relates to the fact that, except for the works carried out at the NSC ‘KhIPT’ NASU in 70–90th of the last century, there are no experimental works in the world on the radiation damage of reactor materials by high-energy electrons with an energy of 100 MeV and above.