Application Of Shock Waves Research Articles

Enhancing photocatalytic dye degradation efficiency through the utilization of shock wave effects on neodymium oxide (Nd2O3)

This article delves into the impact of shockwaves on neodymium oxide (Nd2O3) nanoparticles, aiming to evaluate their physical and chemical stability. Nd2O3 nanoparticles were subjected to varying sets of shock pulses (100, 200, and 300) in photocatalytic dye degradation. The nanoparticles crystallinity and unit cell volume after shockwave exposure were examined using powder X-ray diffraction (PXRD) analysis with unit-cell software. PXRD data revealed no alterations in the crystalline structure, lattice parameter and unit cell volume. Comparisons between pre- and post-shockwave field emission scanning electron microscopy (FE-SEM) portraying data demonstrate that repeated shockwave application causes a decrease in particle size. Raman spectroscopy, under ambient conditions, shows a high intensity after shock conditions intensity will decrease. Furthermore, FTIR spectroscopy revealed the characteristic strong and broad absorption band associated with metal-oxygen (Nd-O) groups in the Nd2O3 nanoparticles. UV–Vis diffuse reflectance spectroscopy (DRS) was used to investigate the bandgap of the Nd2O3 nanoparticles. Initially, the bandgap was measured at 5.96 eV under ambient conditions, but following the shockwave exposure, it was decreased to approximately 5.91 eV. Interestingly, the surface area of the shockwave-treated Nd2O3 nanoparticles is increased and exhibited an increased efficiency in photocatalytic dye degradation. This finding holds promising implications for environmental remediation applications.

Design of a New Supersonic Shock Wave Generator and Application in Power Generation

Wind energy is a kind of renewable energy with great potential for development. This study mainly investigated the application of shock waves generated by high-pressure gases (wind energy) for generating energy. In this study, we designed a new supersonic shock wave generator that can be reused without disassembling and assembling bolts and developed a shock wave monitoring system. It could measure the velocity of the generated shock waves at about Mach 3–5, and the output pressure exceeded 900 kg/cm2 (more than 100 times the input pressure). Then, we developed a power generation system driven by supersonic shock waves based on the characteristics of the new shock wave generator, which could generate high-pressure and high-speed blast waves and could be reused. The shock wave generator can repeatedly generate high-pressure waves to drive the Tesla turbine and then rotate the magnetic energy generator for power generation. This paper used tank pressure, output pressure, gas flow, rotation speed, voltage, and current detected by the system to conduct power generation performance analysis. When the minimum rotation speed was set to 1500 rpm and three bulbs were turned on as loads, the system could generate an average voltage of 36.64 V and an average current of 211.01 mA as output (power about 7731.41 mW).

Overtaking Effects on Spherical Shock Wave Propagation in Metallic Mediums

The propagation of spherical shock waves through metallic mediums have been considered in this paper. The effect of overtaking disturbances in the propagation of spherical shock waves through solids, especially metals such as Aluminium and Copper, has been analysed by employing Chisnell-Chester-Whitham method. Under the influence of spherical shock waves flow variables have been obtained analytically as well as estimated numerically. Expressions for the pressure and the particle velocity behind the shock wave have also been obtained. It is found that shock strength in both the metals decreases as shock propagates through them. Shock velocity and modified shock velocity depict a decreasing pattern with increasing propagation distance. These observations suggest many industrial and medical applications of shock waves.

Is Shock Wave Application Effective on Various Chronic Wounds in the Geriatric Population? Preliminary Clinical Study.

Extracorporeal shock wave therapy (ESWT) is a beneficial adjunct modality for chronic wounds. Limited research has been conducted on pressure ulcers (PUs), while the majority of studies have focused on diabetic foot ulcers (DFUs) and venous leg ulcers (VLUs). This study aimed to evaluate the short-term effects of radial ESWT in older adults with chronic wounds. This study involved a total of 31 wounds: PUs (n=22), VLUs (n=7), and DFUs (n=2). A single radial ESWT was performed with 300 + 100 shocks per cm2, pressure of 2.5 bar, energy of 0.15 mJ/mm2, and frequency of 5 Hz. Assessments using digital planimetry and clinical methods, utilizing the Wound Bed Score (WBS) and the Bates-Jansen Wound Assessment Tool (BWAT) were performed before the radial ESWT application (M0) and one week after (M1). A significant wound decrease in planimetry was noted (pre-ESWT vs post-ESWT), with wound area from 9.4 cm2 to 6.2 cm2, length from 6.4 cm to 3.9 cm, and width from 2.8 cm to 2.1 cm (p<0.001). Additionally, a substantial clinical improvement was noted in both the WBS with a 31.25% increase and the BWAT with a 20.00% increase (p<0.001). It was also found a significant correlation between the planimetric and clinical outcomes for both tools: WBS (r=-0.446, p=0.012) and BWAT (r=0.327, p=0.073). The ESWT application yields substantial immediate clinical effects that support the healing of chronic wounds in older adults. Even a single ESWT session can prove to be clinically effective and beneficial in the management of chronic wounds.

Research Application of Laser-induced Shock Wave for Studying Blast-induced Cochlear Injury

Research Application of Laser-induced Shock Wave for Studying Blast-induced Cochlear Injury

Shock-wave-induced variation in structural, optical and third-order nonlinear properties of an L-ascorbic acid single crystal

The utilization of shock waves plays a pivotal role in the advancement of multiple scientific domains like aerospace, defense, geology, environment, medicine and many more. They serve as essential tools in scientific investigations, enabling the exploration of material behavior under extreme conditions, viz. elevated pressure and temperature. The present study is specifically dedicated to scrutinizing the repercussions of shock waves on an L-ascorbic acid single crystal, to which they were intentionally applied to assess their influence on structural, optical and third-order nonlinearity properties. Powder X-ray diffraction analysis unveiled a discernible overall enhancement in the crystalline quality of the grown crystal following exposure to shock waves. This observation was consistently corroborated by high-resolution X-ray diffraction data, particularly on the (200) crystallographic planes. Furthermore, the optical transmittance of the crystal exhibited a notable increase upon the application of shock waves, while the material's band gap remained unaffected. In parallel, the third-order nonlinearity of the crystal was found to undergo a significant augmentation as a consequence of the shock treatment, as confirmed through Z-scan measurements. These empirical findings unequivocally demonstrate the substantial enhancement in the structural, optical and nonlinear properties of the grown crystal when subjected to shock waves, rendering it well suited for nonlinear optical applications.

Shock Wave-Activated Silver-Loaded Biopolymer Implant Coating Eliminates Staphylococcus epidermidis on the Surface and in the Surrounding of Implants.

Bacterial biofilms on foreign surfaces are considered a primary cause of implant-related infections, which are challenging to treat. A new implant coating was developed, containing anti-infective silver within a biocompatible polymer carrier substance. In addition to its passive effect on the implant surface, highly concentrated anti-infective silver can be released as needed via the application of high-energy shock waves. This intervention could be applied transcutaneously in a clinical setting without the need for additional surgery. We investigated the inhibition of biofilm formation and the effectiveness of eradication after activation of the coating via shock waves in an in vitro biofilm model using Staphylococcus epidermidis RP62A. This was performed via scanning electron microscopy and quantitative microbiology. Additionally, we examined the cytotoxicity of the new coating on normal human fibroblasts and Saos-2 osteoblast-like cells, depending on the silver concentration. All studies were compared to uncoated titanium surfaces Ti6Al4V and a conventional electroplated silver coating. Cytotoxicity toward normal human fibroblasts and Saos-2 osteoblast-like cells increased with higher silver content but remained tolerable at 6%. Compared to uncoated Ti6Al4V and the electroplated silver coating, the new coating with a silver content of 4% and 6% exhibited a significant reduction in adherent bacteria by a factor of approximately 1000. This was also evident via microscopic examination of the surface morphology of the biofilms. Furthermore, following shock wave activation, no bacteria were detectable on either the implant or in the surrounding fluid after a 24 h period.

Effects of single and repeated shock wave application on the osteogenic differentiation potential of human primary mesenchymal stromal cells and the osteoblastic cell line MG63 in vitro.

Introduction: Extracorporeal shock wave therapy is a non-invasive and effective option for treating various musculoskeletal disorders. Recent literature indicates that the parameters for extracorporeal shock wave therapy, such as the optimal intensity, treatment frequency, and localization, are yet to be determined. Studies reporting on the effects of shock wave application on primary mesenchymal stromal cells (MSCs) as well as osteoblastic cell lines in vitro are barely available and not standardized. Methods: In this study, we designed a special setup to precisely expose primary MSCs and the osteoblastic cell line MG63 to shock waves and subsequently analyzed the resulting cellular responses using standardized protocols to investigate their viability, proliferation behavior, cytokine secretion, and osteogenic differentiation potential in vitro. The shock wave transducer was coupled to a specifically designed water bath containing a 5mL tube holder. Primary human MSCs and MG63 cells were trypsinated and centrifuged in a 5mL tube and exposed to single and repeated shock wave application using different intensities and numbers of pulses. Results: Single treatment of MSCs using intensities 5, 10, 15, and 20 and pulse numbers 100, 250, 500, 750, and 1,000 at a constant pulse repetition frequency of 1Hz resulted in a decreased viability and proliferation of both cell types with an increase in the intensity and number of pulses compared to controls. No significant difference in the osteogenic differentiation was observed at different time intervals in both cell types when a single shock wave application was performed. However, repeated shock wave sessions over three consecutive days of primary MSCs using low intensity levels 0.1 and 1 showed significant osteogenic differentiation 4-fold higher than that of the extracted Alizarin Red S at day 14, whereas MG63 cells showed no significant osteogenic differentiation compared to their corresponding controls. More specifically, repeated shock wave application triggered a significant downregulation of COL1A1, upregulation of RUNX2, and sustained increase of OCN in primary MSCs but not in the cell line MG63 when induced toward the osteogenic differentiation. Discussion: The effects of shock wave application on MSCs make it an effective therapy in regenerative medicine. We established a protocol to analyze a standardized shock wave application on MSCs and were able to determine conditions that enhance the osteogenic differentiation of MSCs in vitro.

Structure, morphology, and magnetic properties of Fe microparticles as impact on shock waves

To analyze the stability of the physical and chemical properties of Fe, samples were investigated by subjecting them to shockwaves. The magnetic response of Fe to the external magnetic field mainly depends on the degree of magnetic ordering and the temperature of the sample. Powder X-ray diffraction (PXRD) characterization techniques were employed to analyze the crystallinity and cell volume of the structure obtained from Rietveld refinement. The sample was exposed to a shockwave ∼ 2.2 Mach with a different set of repetitions (such as 50, 100, 150, and 200). Refined data from PXRD shows no structural change in the crystallinity of the system. Williamson-Hall analysis demonstrates that the stress and strain between Fe change during the application of shocks. Thus, a noticeable change in the volume of the unit cell is observed. By subjecting the particles to repetitive shockwaves, their size was reduced. This was confirmed through imaging with a scanning electron microscope (SEM), which compared the particle images before and after the application of shockwaves from different sets. The magnetic field and temperature dependencies were applied to measure the ambient and shocked conditions. The magnetization results indicate an increase in magnetic moment due to the influence of the shockwave conditions. Also, 100 shocks show a transition behavior from ferromagnetic to paramagnetic. Based on its convincing reversible magnetic phase transition behavior, Fe is a potential material for applications in magnetic sensors and spintronics.

Influence of the skull bone and brain tissue on the sound field in transcranial extracorporeal shock wave therapy: an exvivo study.

Focused ultrasound is mainly known for focal ablation and localized hyperthermia of tissue. During the last decade new treatment options were developed for neurological indications based on blood-brain-barrier opening or neuromodulation. Recently, the transcranial application of shock waves has been a subject of research. However, the mechanisms of action are not yet understood. Hence, it is necessary to know the energy that reaches the brain during the treatment and the focusing characteristics within the tissue. The sound field of a therapeutic extracorporeal shock wave transducer was investigated after passing human skull bone (n=5) or skull bone with brain tissue (n=2) in this ex vivo study. The maximum and minimum pressure distribution and the focal pressure curves were measured at different intensity levels and penetration depths, and compared to measurements in water. Mean peak negative pressures of up to -4.97 MPa were reached behind the brain tissue. The positive peak pressure was attenuated by between 20.85 and 25.38 dB/cm by the skull bone. Additional damping by the brain tissue corresponded to between 0.29 and 0.83 dB/cm. Compared to the measurements in water, the pulse intensity integral in the focal spot was reduced by 84 % by the skull bone and by additional 2 % due to the brain tissue, resulting in a total damping of up to 86 %. The focal position was shifted up to 8 mm, whereas the basic shape of the pressure curves was preserved. Positive effects may be stimulated by transcranial shock wave therapy but damage cannot be excluded.

Experimental and numerical investigation of the laser shock-based paint stripping process on CFRP substrates

Various laser shock wave applications have been proposed for metals; the most popular is the laser shock peening. In composites, the use of the laser shock wave technology is still at an early stage. Laser shock paint stripping (LSPS) is a method where a laser-induced shock wave is used to remove a paint from a substrate. In this study, a combined experimental–numerical study was performed on the LSPS on Carbon Fiber Reinforced Polymers (CFRP) substrates. Two types of specimens were investigated: specimens with an epoxy structural primer covered by a polyurethane base and a clear coat and specimens with the above layers plus an epoxy exterior primer between the epoxy structural primer and the polyurethane layer. The specimens were shot using various laser intensities aiming to obtain the stripping threshold and the stripping percentage as functions of the laser intensity. The diameter of the stripped area was measured by a profilometer. An electron microscope was used to evaluate the stripping efficiency. In parallel, a numerical model was developed using the LS-DYNA explicit Finite Element (FE) software. For the modeling of the CFRP, a progressive damage model with strain rate parameters was used while for the epoxy an elastic–plastic-hydrodynamic material model combined with the Gruneisen equation of state. The interface between these two materials was modeled using cohesive zone elements of zero thickness, which follow a bi-linear traction-separation law. Calibration of the modeling of the shock wave propagation inside the composite material was achieved through the comparison of the back-face velocity profiles, measured by a velocity interferometer system for any reflector system. The results from the multiple tests conducted revealed the repeatability of the process and the significant effect of the laser intensity. On the other hand, the model managed to predict well the back face velocity–time profile but in most cases, it failed to predict the stripping pattern. This is mainly due to lack of crucial material properties and the assumptions made in the modeling of the applied pressure profile.

On-Demand Release of Anti-Infective Silver from a Novel Implant Coating Using High-Energy Focused Shock Waves.

Implant-related infections are a significant concern in orthopedic surgery. A novel anti-infective implant coating made of bioresorbable polymer with silver nitrate was developed. A controlled release of silver ions into the vicinity of the prosthesis can be triggered on-demand by extracorporeal shock waves to effectively combat all clinically relevant microorganisms. Microscopy techniques were used to examine the effects of shock wave application on coated titanium discs. Cytotoxicity was measured using a fibroblast proliferation assay. The anti-infective effect was assessed by monitoring the growth curves of three bacterial strains and by conventional culture. Microscopic analysis confirmed surface disruption of the coatings, with a complete release of silver in the focus area after shock wave application. Spectrometry detected an increase in silver concentration in the surrounding of the discs that surpassed the minimum inhibitory concentration (MIC) for both S. epidermidis RP62A and E. coli ATCC 25922. The released silver demonstrated an anti-infective effect, significantly inhibiting bacterial growth, especially at 6% and 8% silver concentrations. Cytotoxicity testing showed decreasing fibroblast viability with increasing silver concentration in the coating, with 6% silver maintaining viability above 25%. Compared to a commonly used electroplated silver coating on the market, the new coating demonstrated superior antimicrobial efficacy and lower cytotoxicity.

Retracted: Clinical Application of Shock Wave in the Treatment of Avascular Necrosis of the Femoral Head in the Early and Middle Stages.

[This retracts the article DOI: 10.1155/2022/3832670.].

Nano-composite semi-flexible polyurethane foams containing montmorillonite intercalated/exfoliated in situ during the synthesis of the intermediate polyester-polyols obtained from PET wastes

Low-cost nano-composite semi-flexible polyurethane foams with improved thermal and mechanical features were obtained using a cost-saving and environmentally friendly preparation process of an intermediate composite, obtained from polyethyleneterephthalate (PET) wastes, depolymerization/chemical modification agents from renewable resources and unmodified natural montmorillonite. The process implies tailoring the polyester-polyols chemical structure/ composition and using specific catalysts, aiming to intercalate the montmorillonite layers during the synthesis reactions, while maintaining the appropriate properties of the products required for the preparation of polyurethane semi-flexible foams, thus avoiding conventional treatments of the nanofiller, involving the use of solvents, additional energy consumption by heating and stirring, as well as longer processing time. The polyester-polyols composites and the polyurethane semi-flexible foams obtained therefrom were investigated by specific analytical methods. In this regard, the foams showed an improvement of the thermal stability, and values of Young’s moduli and compression strengths about double or higher, compared to conventional semi-flexible polyurethane foams of same density. The potential applications of such foams target shock wave damping sandwich systems for marine structures.

Application of Laser Shock Waves in Additive Technology

Application of Laser Shock Waves in Additive Technology

Diffraction and microscopic studies on lithium sulfate doped l-Threonine under dynamic shock wave exposed conditions

Scientists of shock wave research have been continuously contributing with a great deal of significant effort so as to carry forward the tempo in achieving much more applications of shock waves in the branch of solid state sciences. In the present framework, the evaluation of the structural phase-stability and morphological stability of lithium sulfate doped l-Threonine powder samples have been performed under shock wave exposed conditions and the results have been evaluated by diffraction and microscopic techniques. Based on the observed crystallographical results, it is authenticated that the title specimen retains the original crystal system (P212121) with a few internal changes such as new peak appearance and disappearance of existing peaks that are observed due to the occurrence of micro-distortions and re-organization of hydrogen bond networks as well as rotational order-disorder of the lithium sulfate under shock loaded conditions. SEM micrographs clearly demonstrate the formation of cracks and breaking of particlesundershocked conditions.

A Comprehensive Review of the Effects of Extracorporeal Shock Wave Therapy on Stroke Patients: Balance, Pain, Spasticity.

Stroke remains a leading cause of disability worldwide, with survivors often experiencing impairments in balance, pain, spasticity, and control that limit their ability to perform daily living activities. Extracorporeal shock wave therapy (ESWT) has emerged as a potential treatment modality to improve these outcomes in stroke patients. This review aims to provide a comprehensive examination of the effects of ESWT on stroke patients, focusing on the theoretical background, balance, pain reduction, muscle spasticity and control, and upper and lower extremities. This study reviewed the use of ESWT in treating balance, pain, and spasticity in stroke patients, focusing on articles published in PubMed between January 2003 and January 2023. Systematic reviews related to stroke were used to provide an overview of stroke, and a total of 33 articles related to balance, pain, and spasticity were selected. ESWT has several shock wave generation methods and application methods, and it has been shown to have positive therapeutic effects on various aspects of rehabilitation for stroke patients, such as improving balance, reducing pain, decreasing muscle spasticity and increasing control, and enhancing functional activities of the upper and lower extremities. The efficacy of ESWT may vary depending on the patient's condition, application method, and treatment area. Therefore, it is important to apply ESWT according to the individual characteristics of each patient in clinical practice to maximize its potential benefits.

Effect of laser shock peening on austempered ductile iron

In this study, laser shock peening (LSP) has been applied on austempered ductile iron (ADI) to determine the optimum laser power and spot overlapping rate required for automotive gear applications. The surface roughness and phases present were studied to understand the effect of the laser shock wave application on the material. An increase in the mean surface roughness was achieved when the laser spot overlap increased from 20% to 60%. A significant increase in the microhardness was obtained in the surface and sub-surface, indicating an increased dislocation density of the material. Compressive residual stress depth and magnitude characterized by X-ray Diffraction (XRD) and Incremental Hole Drilling (IHD) were found to increase with laser power density. This work significantly identifies the pathway toward the engineering manufacture of austempered ductile iron and the application of LSP for the automotive drive-train industries.

Cardiac Shock Wave Therapy in Cardiovascular Diseases

Cardiovascular disease is one of the leading causes of death worldwide, placing a huge burden on patients and healthcare systems. Cardiac shock wave (CSW) technology is a non-invasive treatment method. In recent years, some scholars have discovered that extracorporeal shock wave can improve cardiovascular ischemic lesions. This article reviews the latest progress in basic research and clinical application of cardiac shock wave technology in cardiovascular medicine and reviews its efficacy and potential mechanisms in different diseases. First, the principle of shock waves and their application potential in cardiovascular medicine are introduced. Then, from the aspects of basic research and clinical application, the mechanism and clinical efficacy of shock waves in cardiovascular diseases such as coronary heart disease, myocardial ischemia-reperfusion injury, atrial fibrillation, atherosclerosis, and coronary artery calcification are discussed, as well as its advantages and limitations. Animal experiments and clinical studies have found that low-energy extracorporeal shock waves can upregulate the expression of vascular endothelial growth factors, promote angiogenesis, promote nitric oxide production, increase local blood perfusion, significantly reduce angina symptoms, and improve left ventricular function and remodeling. Finally, the future development trend of shock wave technology is prospected. This review provides an introduction to the properties, biomechanical effects, treatment mechanisms of cardiovascular diseases, research status and development prospects of extracorporeal shock waves. Keywords: Cardiac shock Wave Therapy, Cardiovascular diseases, ESWT

Electroencephalographic Response of Brain Stimulation by Shock Waves from Laser Generated Carbon Nanotube Transducer.

Neuromodulation is used to treat neurological disorders. Focused ultrasound can deliver acoustic energy to local regions of the brain, including deep brain structures. In addition, it is possible to induce the activation or inhibition of nerves through parameter adjustments of focused ultrasound. Laser-generated focused ultrasound (LGFUS) has demonstrated a potential use in precise therapeutic ultrasound applications owing to the ability to produce high-pressure, broadband frequency of shock waves with a tight focal spot, resulting in confined acoustic exposure of a small area. However, there have been few studies of neurostimulation using shock waves with pulse durations of several nanoseconds. The purpose of this study is to investigate the possibility of neurostimulation by shock waves generated from a focused Carbon Nanotube (fCNT) transducer. We measured electroencephalographic (EEG) signals in three rat brains before and after shock wave stimulation and compared them in the time and frequency domains. In the time domain, the number of peaks of EEG signals was measured significantly higher after shock wave stimulation than before stimulation in all three rats. The three rats showed differences in three frequency bands: theta(4-7 Hz), alpha(8-12), and 1-30 Hz, before and after shock wave stimulation (p < 0.001). These differences in EEG signals after shock wave stimulation of three rats were confirmed mainly because of shock waves. The stimulation of a rat brain was feasible using shock waves generated by the fCNT transducer. This study provides a basis for the applications of shock waves to brain stimulation for precise targeting.