Effects Of Shock Waves Research Articles

INFLUENCE OF PULSED BEAM-PLASMA IMPACTS ON THE STRUCTURAL CHARACTERISTICS AND MECHANICAL PROPERTIES OF THE SURFACE LAYER IN INCONEL 718 ALLOY

The results of studying the effects of pulsed flows of helium ions (HI) and helium plasmas (HP) on the Inconel 718 alloy prepared by additive technology by selective laser melting followed by heat treatment are presented. The main structural changes in the irradiated surface layer (SL) are determined for two modes of irradiation - soft (with radiation power density q = 2 ∙108 W/cm2 at pulse duration τ = 50 ns) and hard (at q = 1.5 ∙109 W/cm2, τ = 25 ns). The number of pulsed actions in each mode was N = 10 and 20. It has been found that in the initial state and after irradiation, the alloy under study is a single-phase nickel-based solid solution with an fcc lattice. The impact on the alloy of pulsed HI and HP flows leads to a change in the initial texture in the 220 direction to texture 111. This change in the texture favored the occurrence of the plastic deformation (PD) process observed in the irradiated SL, during which in metals with an fcc lattice, under the action of applied thermal stresses, slip occurs predominantly along the {111} planes. The influence of the irradiation mode of the investigated alloy on the parameter of its crystal lattice is noted. In the soft mode of exposure to HI and HP flows, the lattice parameter a decreases compared to the initial value, which may be due to the action of residual macrostresses, as well as to the evaporation of atoms of impurity elements located in lattice interstices from the SL. In the hard irradiation regime, the parameter a increases, which is due to the dominant influence of the mechanism of implantation of helium ions into the alloy, which contributes to the increase in the value of a. It have been shown that the observed structural changes in the SL of the alloy lead to a decrease in microhardness and softening of the remelted layer. The role of thermal and shock-wave effects in the processes of PD and structural changes in SL under the implemented irradiation conditions was estimated by numerical simulation.

Effect of extracorporeal shock wave combined with pregabalin on patients with post-herpetic neuralgia.

Post-herpetic neuralgia (PHN) is a chronic pain that is difficult to treat and lasts a long time, which poses a threat to patients' physical and mental health (MH) and quality of life. To analyze the effectiveness of extracorporeal shock wave (ESW) combined with pregabalin on PHN and its impact on PHN patients' quality of life with the help of a random number table. Totally 164 PHN patients were assigned to a control group (n = 82) or an observation group (n = 82). The observation group was given pregabalin combined with ESW treatment, while the control group was only given pregabalin. In the 2 groups, the general clinical data of the patients were compared. The inflammation levels including erythrocyte sedimentation rate (ESR), CRP, lymphocyte count and albumin level in both groups were compared prior to and following therapy. In addition, the difference between pretreatment and post-treatment in the 2 groups was compared with respect to neuralgia and quality of life. After treatment, the observation group exhibited much lower ESR and CRP but quite higher lymphocyte count and albumin level relative to the control group (P < .05). Additionally, the improvement in visual analogue scale (VAS) scores and short form 36 (SF-36) scale scores including role-emotional (RE), MH, physical function (PF), general health (GH), bodily pain (BP), social function (SF), vitality (VT), and role-physical (RP) scores in the 2 groups were pronounced following treatment, which was more apparent in the observation group (P < .05). The combination of ESW with pregabalin can reduce the inflammation, improve the quality of life of PHN patients and effectively relieve their neuralgia.

Research on non-equilibrium condensation of supercritical carbon dioxide in sCO2 power systems

Based on the consideration of sustainable development and energy efficient transformation, people propose using renewable energy to upgrade traditional power generation systems. The supercritical carbon dioxide (sCO2) Brayton cycle has a great utilization potentiality in thermodynamic systems, such as solar thermal power generation systems. When the CO2 fluid flows into the compressors of sCO2 power systems, there is a risk of non-equilibrium condensation due to local expansion and acceleration, which seriously threatens the stability of the whole system. The convergent-divergent nozzle is usually used to study non-equilibrium condensation. In this paper, the wet steam model is used to simulate the non-equilibrium condensation of the CO2 fluid near its critical region in a convergent-divergent nozzle. The phase change model and the thermophysical equation of state are verified by experimental data. The non-equilibrium condensation process is analyzed, and the droplet nucleation process and droplet growth process are described. Non-equilibrium condensation releases the latent heat and forms a condensation shock wave. The influences of the shock wave effect on temperature, pressure, and other parameters are discussed. The initial condensation position and critical subcooled temperature under different inlet conditions are analyzed.

Оценка изменения безопасных расстояний при нарушениях регламента испытаний газопроводов

Accidents occurring during the process of gas pipelines testing are characterized by the impossibility of the occurrence of thermal radiation of jet flames and fire in the pit-damaging factors dominating the operation stage of the facility. In addition, what is happening cannot be accompanied by the baric effect of chemical explosions. However, taking into account the significant increase in pressure in the gas pipeline during pneumatic tests, such damaging factors of the accident as the scattering of fragments, the pressure effect of a high-speed jet and the baric effect of the primary shock wave are amplified. The issue of ensuring the safety of personnel present near the test site becomes relevant. As a result, the need occurs to determine precisely the safe distances to the gas pipeline. Protective zones for the population are also established based on the identified safe distances. Within the framework of the risk-oriented approach, the procedure for determining safe distances is reduced to calculating the distances at which damaging factors lose their damaging properties. When assigning protective zones, it is required to consider the possibility of changing the indicator under consideration, due to probable errors of personnel in the preparation and conduct of tests. Even non-critical miscalculations can significantly affect the determination of a safe distance. The article presents an assessment of the relative values of safe distances, taking into account possible violations of the regulations regarding backfilling and filling with water or air, during hydraulic or pneumatic tests of gas pipelines. Relative values of safe distances are also established in terms of the scattering of fragments and the impact of an air shock wave of a physical explosion on people and building objects.

Nanosecond volume discharge in the non-stationary high-speed profiled channel flow

The aim of the work is an experimental and numerical investigation of the interaction between the pulse volume discharge with a high-speed flow in the rectangular profiled channel (obstacle on the bottom wall). The special type of combined discharge—pulse volume discharge with preionization by an ultraviolet radiation from plasma sheets—is used. The flow around the obstacle influences the pulse discharge plasma distribution. The short-pulse initiation of a high power discharge leads to the effects observable in the time range up to millisecond. Ultrafast local heating of the medium with the formation of blast (shock) waves is carried out during the creation of a high nonequilibrium sub microsecond pulsed plasma. The duration of the shock-wave effect of the pulsed discharge is from 20 to 120 μs in supersonic and transonic flow. The spatially inhomogeneous distribution of energy input in a supersonic flow associates with the density lowest areas, which occur in a gas flow regime in a channel with an obstacle on the bottom. Discharge localization regions are sources of more intense wall surface local heating observed in the infrared range. A numerical calculation is carried out in order to match the calculated and experimental gas dynamical configurations.

Dynamic response analysis of spherical pressure hull implosion inside adjacent underwater structure

The implosion will occur when the pressure hulls have a geometric imperfection or are impacted from the outside, which could cause the collapse of submerged vessels. In this work, the open-source finite element solver OpenRadioss is used to analyze the implosion caused by the failure of the spherical pressure hull and the interference with the adjacent cylindrical shell in the double-hulled cabin of a submarine. Firstly, the implosions of the cylindrical tube and destruction of the spherical pressure hull are compared with experimental results. Secondly, the underwater implosion of the sphere is analyzed inside a cylinder with local impacts in different induced directions. The results found the flow field and structural deformation show obvious directivity, in which the deformations of the cylindrical shell are mainly caused by the absorption action instead of the shock wave effect when implosions occur in the direction closer to the cylinder. Finally, the dynamic responses of implosions are discussed under different triggering modes and hydrostatic pressures. We found that the structural deformation and energy evolution are similar when the sphere is subjected to a collapse load. However, the effect of triggering modes gradually becomes larger with the increase of hydrostatic pressure.

Investigation of the effect of friction force on the energy absorption characteristics of thin-walled structures loaded with axial impact force

In recent years, there has been a significant increase in studies aimed at enhancing the energy absorption capabilities of thin-walled structures used in vehicles. These studies aim to mitigate the adverse effects of shock waves released during crashes by incorporating recesses that trigger folding on the walls of crash boxes, thereby increasing energy absorption. This particular study investigates the energy absorption and crushing behaviors of interpenetrating thin-walled structures under axial crushing conditions. Two different configurations were modeled to determine the contribution of friction force in dampening impacts in thin-walled structures. One configuration exhibited classical folding, while the other initiated folding after interpenetration upon the application of an axial impact load. The interpenetrating structures generate friction forces through recesses and protrusions on the surface of the crash box to provide energy absorption. The simulations were conducted using the finite element method (FEM) in a non-linear explicit dynamic collision scenario. The crash scenarios for both configurations were analyzed under identical conditions using two different materials (DP-600 and DP-800) and three different thicknesses (1.2 mm, 1.4 mm, and 1.5 mm). The dynamic crash simulations were compared based on Specific Energy Absorption (SEA), Total Energy (ET), Peak Crush Force (PK), Crush Force Efficiency (CE), and Mean Crushing Force (FM) values to examine the effects of friction force on energy absorption capabilities and crushing behaviors of the crash boxes. The analysis results demonstrated that friction force and energy absorption play a positive role in the crashworthiness characteristics of thin-walled structures.

Simulation of Shockwave Effects on a Ship-like Structure due to Underwater Explosions

Simulation of Shockwave Effects on a Ship-like Structure due to Underwater Explosions

The effect of extracorporeal shock wave on joint capsule fibrosis in rats with knee extension contracture: a preliminary study

ABSTRACT The purpose of this study was to observe the therapeutic effect of extracorporeal shock wave (ESW) on extensional joint contracture of knee joint in rats and its mechanism on articular capsule fibrosis. Thirty-two SD rats were randomly divided into blank control, immobilization, natural recovery, and ESW intervention groups. Except for the control group, the left knee joints of other rats were fixed with external fixation brace for 4 weeks when they were fully extended to form joint contracture. The effect of intervention was assessed by evaluating joint contracture, total cell count and collagen deposition in joint capsule, and protein expression levels of TGF-β1, p-Smad2/3, Smad2/3, p-JNK, JNK, I and III collagen in joint capsule. ESW can effectively reduce arthrogenic contracture, improve the histopathological changes of anterior joint capsule, inhibit the high expression of target protein and the excessive activation of TGF-β1/Smad2/3/JNK signal pathway. Inhibition of excessive activation of TGF-β1/Smad2/3/JNK pathway may be one of the potential molecular mechanisms by which extracorporeal shock wave can play a role.

A preliminary investigation into the impact of shock wave therapy and sonotherapy on postural control of stepping tasks in patients with Achilles tendinopathy.

The outcomes of physical therapy are commonly assessed with subjective scales and questionnaires. Hence, a continuous search to identify diagnostic tests that would facilitate objective assessment of symptom reduction in those patients with Achilles tendinopathy who undergo mechanotherapy. The main aim of this study was to evaluate and compare the effectiveness of shock wave and ultrasound treatments, using objective posturographic assessment during step-up and step-down initiation. The patients with non-insertional Achilles tendinopathy and pain lasting for more than 3 months were randomly assigned to one of the experimental groups, i.e., radial shock wave therapy (RSWT), ultrasound therapy, or placebo ultrasound. All groups also received deep friction massage as the primary therapy. The transitional locomotor task was performed with the affected and unaffected limb in random order, on two force platforms under two conditions (step-up and step-down). The recording of center of foot pressure displacements was divided into three phases: quiet standing before step-up/step-down, transit, and quiet standing until measurement completion. Pre-intervention measurements were performed and then short-term follow-ups at weeks 1 and 6 post-therapy. The three-way repeated measures ANOVA showed few statistically significant two-factor interactions between therapy type, time point of measurement and the type of the locomotor task. Significant increases in postural sway were observed in the entire study population throughout the follow-up period. Three-way ANOVAs revealed a group effect (shock wave vs. ultrasound) on almost all variables of the quiet standing phase prior to step-up/step-down initiation. Overall, postural stability before the step-up and step-down tasks appeared to be more efficient in patients who had undergone RSWT compared to the ultrasound group. Objective posturographic assessment during step-up and step-down initiation did not demonstrate therapeutic superiority of any of the three therapeutic interventions used in patients with non-insertional Achilles tendinopathy.Clinical Trial Registration: The trial was prospectively registered in the Australian and New Zealand Clinical Trials Registry (no. ACTRN12617000860369; registration date: 9.06.2017).

Underwater Arc Discharge Treatment Using a High-Voltage Arc-Robust Supply

Underwater arc discharge is one of the most effective water treatment methods because of the effects of intense shockwaves and high ultraviolet radiations. In this paper, a high-voltage underwater arc discharge system is proposed to study the inactivation of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Escherichia coli</i> bacteria, which has an arc-robust feature. It consists of a high-voltage capacitor charger and a discharge circuit. The high-voltage capacitor charger is developed by an LCCL resonant converter to reach a current supply scheme that is inherently protected and robust against arc discharge. The detailed mathematical analysis and the design optimization of the resonant converter are presented. The discharge circuit is developed by a two-step spark gap scheme using an ultrafast highvoltage trigger circuit, providing a reliable system operation independent of the water conductivity. The proposed underwater arc discharge system is applied to 500ml of pollutant water to study the system’s performance on the inactivation of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E. Coli</i> bacteria. The proper microbiological tests are carried out, showing the effectiveness of the proposed underwater arc discharge system. The complete inactivation of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E. Coli</i> bacteria is achieved in an extremely short treatment time. Moreover, the experimental results are presented, which validate the desired performance of the proposed underwater arc discharge system.

Analysis of the Ultimate Load-Bearing Capacity of Steel-Clad Concrete-Filled Steel Tube Arched Protective Doors under Blast Shock Waves

The mechanism of blast damage to steel-clad concrete-filled steel tube (SCCFST) arched protective doors is studied using the dynamic response characteristics of such loads under the action of blast shock wave loads, and the ultimate blast load-bearing capacity formula is derived based on the “plastic hinge” damage mode of the doors using limit analysis, which explores the effect of the blast shock wave. The effect of the design parameters of each component of the protective door on the load-bearing capacity subjected to blast shock waves is discussed. Results show that the damage mechanism under a uniform radial load on the outer surface of the SCCFST arched protective door is characterized by the plastic hinge lines at the two arch feet, which results in a slip fracture and renders the protective door unstable. The load-bearing capacity of the SCCFST arched protective door depends on the coordinated functioning of the cross-sectional outer cladding steel plate and inner connecting partition, concrete-filled steel tube, and restraining concrete outside the steel tube. The load-bearing capacity of each of the three parts differs with the varying cross-sectional occupancies.

Comparison of Extracorporeal Shockwave and High-Intensity Laser in Treating Chronic Plantar Fasciitis

Background: Plantar fasciitis (PF), an inflammation of the plantar fascia. This study compared the effects of the extracorporeal shockwave and high-intensity laser in reducing pain and enhancing function in chronic plantar fasciitis patients, who have failed to achieve results by the conservative treatment. Aim: To explore the best non-invasive treatment option for chronic PF within the scope of physical therapy. Method: After registry of trial the data collection was started.A total of45 chronic PF patientswere divided, randomly into three groups. Group 1 received BTL-6000 Shockwave therapy (ESWT) , group 2 received Diowave 60W Class IV hot Laser (HILT) and group 3 (the control group) was not given any electrotherapy treatment. All groups were given some exercises for the home plan. The groups were assessed with the Visual Analogue scale (VAS) and foot functional index (FFI) at baseline, post-treatment, and follow-up of 2 months. Result: The mean age of participants was 39.66±10.05,38.06 ±12.64 and 37.40±13.18 for ESWT, HILT group and control groups respectively. There was significant difference in VAS and FFI score p=&lt;0.001 across the time. Pre-treatment and post-treatment scores were significantly different but post treatment and follow-up scores were not significantly different for both VAS and FFI score (p=1.00). Practical implication: This study will help us to find out chronic Plantar fasciitis treatment within physical therapy and electrotherapy domain. As both these modalities are non-invasive, cost effective and proved as effective treatment for reduction of pain and improvement of pain in chronic plantar fasciitis patients. Conclusion: Extracorporeal shockwave have been promising treatment for chronic plantar fasciitis but High intensity LASER therapy effectiveness was not explored a lot in previous literature. The study concluded that both ESWT and HILT are effective in reducing pain and improving function on VAS and FFI, though the ESWT group was found better than both groups in FFI score and VAS across time on the basis of the mean differences across time. Keywords: Exercise, Extra-corporeal shockwave therapy, heel pain, High-intensity Laser therapy, Plantar fasciitis

(359) Validation of Peripheral Endothelial Assessment and Central Arterial Tonometry as Tools in Arteriogenic Erectile Dysfunction and Can These Tools Aid in Better Selection of Patients for LI-ESWT Treatment Improving Success Rates?

Abstract Introduction An important mechanism of ED is vascular endothelial function injury or disorder and low-intensity extracorporeal shock wave therapy (LI-ESWT) can stimulate and promote vascular regeneration, especially in failed PDE5i. The present selection criteria used for EDSWT are subjective in the form of IIEF, EHS or SEP with no objective definition of the extent of vascular involvement. There is a need to comprehensively evaluate ED including the extent of local and systemic involvement. Objective To develop objective parameters of validated assessment of endothelium in men with organic erectile dysfunction and to evaluate if they could be used to plan accurate PDE5i, non-invasive modalities of treatment. Methods In a prospective study, patients who were earlier evaluated and had vasculogenic ED and failed PDE5i treatment were clinically re-evaluated with questionnaires and CDDU. Additionally endothelial function and large arterial stiffness was assessed with the Vendys (reactive hyperaemia) &amp; Sphygmocor (central arterial pressure waveform analysis). Categories identified were, endothelial dysfunction by Vendys, Aortic augmentation index abnormality by Sphygmocor (age corrected), combined abnormality with poor scores with or without metabolic comorbidity. All three groups underwent LI-ESWT with low dose PDE5 inhibitors with a revised protocol. Results Validation of diagnostic tools was done in thirty five patients aged 48.24 ± 4.6 years (mean ± SD) with a mean IIEF score of 8.4 were evaluated by the three techniques. Positive predictive value (PPV) of the three techniques was similar, in the range 89-91% and a negative predictive value (NPV) around 41-45%. CDDU had highest sensitivity at 85%, but low specificity of 55%, followed by Sphygmocor® at 77% and Vendys at 75% and the latter techniques had better specificity of 70%. Parameter Penile Doppler SphygmoCor® Vendys® Value 95% CI Value 95% CI Value 95% CI Sensitivity 85 % 70.1-94.3 77.5 % 61.5-89.1 75 % 58.8-87.3 Specificity 55.6 % 21.2-86.3 70.0 % 34.7-93.3 70 % 34.7-93.3 Positive likelihood Ratio 1.91 0.91-4.02 2.58 0.99-6.76 2.50 0.95-6.55 Negative likelihood Ratio 0.27 0.11-0.69 0.32 0.16-0.65 0.36 0.18-0.70 PSV (N) IIEF Class (N) % &amp;lt; 25 (22) Severe (18) 81.82 44.00 Mod (3) 13.64 Mild (1) 4.55 25-30 (17) Severe (0) 0.00 34.00 Mod (14) 82.35 Mild (3) 17.65 CDDU Vs IIEF score The patients were grouped into three arms Vendys abnormality, Sphygmocor and combined; for Li-ESWT treatment (15 each). Pre and Post questionnaire based assessment was done and maximum improvement of IIEF was in the Alx abnormality arm with poor results in combined abnormality. Conclusions The aortic strain index and distensibility index were impaired in patients with ED. Vendys® SphygmoCor® are new tools in diagnosis of ED and superior to penile Doppler or questionnaire assessment. Li-ESWT is most beneficial in patients with Aortic elastic abnormality probably due shock wave effect on sheer stress of vessels by altering vessel wall pulsatality and resistivity index. Disclosure No

Review on Anti-Fatigue Performance of Gradient Microstructures in Metallic Components by Laser Shock Peening

Laser-shock-peening technology is an international research hotspot in the surface-strengthening field, which utilizes the mechanical effects of laser-induced plasma shock waves to effectively improve the fatigue performance of metallic components by introducing the gradient microstructures and compressive residual stress into the surface layer of processed materials. The fatigue failure caused by high-frequency vibrations in aeroengines during service is the most important threat to flight safety, and this case is more prominent for military aeroengines because their service situation is harsher. The present paper focuses on components such as high-temperature components, fan/compressor blade, and thin-walled weldments, and it systematically introduces the researching findings about surface nanocrystallization and compressive residual stress formation mechanism in typical aeronautical metallic materials treated by laser shock peening. The contents mainly involve the characteristics, formation process, fatigue resistance mechanism, thermal stability of residual compressive stress, and nanocrystallization generated by laser shock peening.

Efficacy of Extracorporeal Shockwave Therapy on Pain and Function in Myofascial Pain Syndrome: A Systematic Review and Meta-analysis of Randomized Clinical Trials.

The aim of the study is to examine the effectiveness of extracorporeal shockwave therapy in reducing pain, improving functionality, joint range of motion, quality of life, fatigue, and health status self-perception in people with myofascial pain syndrome. PubMed, the Cochrane Library, CINAHL, the Physiotherapy Evidence Database, and SPORTDiscus were systematically searched for only randomized clinical trials published up to June 2, 2022. The main outcome variables were pain, as reported on the visual analog scale and pressure pain threshold, and functionality. A quantitative analysis was conducted using the inverse variance method and the random effects model. Twenty-seven studies were included ( N = 595 participants in the extracorporeal shockwave therapy group). The effectiveness of extracorporeal shockwave therapy for relieving pain was superior for the extracorporeal shockwave therapy group compared with the control group on the visual analog scale (MD = -1.7 cm; 95% confidence interval = -2.2 to -1.1) and pressure pain threshold (mean difference = 1.1 kg/cm 2 ; 95% confidence interval = 0.4 to 1.7) and functionality (standardized mean difference = -0.8; 95% confidence interval = -1.6 to -0.04) with high heterogeneity. However, no differences were found between extracorporeal shockwave therapy and other interventions as dry needling, exercises, infiltrations, and lasers interventions. Extracorporeal shockwave therapy is effective in relieving pain and improving functionality in patients with myofascial pain syndrome compared with control and ultrasound therapy. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME. Upon completion of this article, the reader should be able to: (1) Determine the effectiveness of radial and focal extracorporeal shockwaves on pain perception, the pressure pain threshold, and functionality in people with myofascial pain syndrome; (2) Describe the intervention protocol of extracorporeal shockwave therapy to improve pain perception in people with myofascial pain syndrome; and (3) Describe the advantages and disadvantages of extracorporeal shockwave therapy versus other intervention such as dry needling. Advanced. The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s) ™. Physicians should only claim credit commensurate with the extent of their participation in the activity. Advanced. The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s) ™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Effect of radial shock wave and ultrasound therapy combined with traditional physical therapy exercises on foot function and dorsiflexion range in plantar fasciitis: a prospective randomized clinical trial.

This study aimed to assess the effect of radial shock wave and ultrasound therapy combined with traditional physical therapy on foot function and range of motion in chronic plantar fasciitis. Sixty-nine participants with chronic plantar fasciitis (25-56 years) were allocated randomly into three groups. Group (A) received ultrasound (US) therapy plus conventional physical therapy exercises (in the form of stretching, strengthening exercise, and deep friction massage), Group (B) received a radial shock wave (RSW) therapy plus conventional physical therapy exercises, and Group (C) received a combination of both RSW and US therapy in addition to conventional physical therapy exercises, with 3 sessions per week for US therapy and one session for RSW therapy, in addition to 45 minutes of exercises for all groups for 4 consecutive weeks. Foot function was assessed using the foot function index (FFI), and ankle dorsiflexion range of motion was measured using the Baseline® bubble inclinometer at baseline and 4 weeks following treatment. ANOVA revealed significant differences (p<0.05) in the measured outcomes among the groups after treatment. Tukey's honest significant difference post-hoc test demonstrated a highly statistically significant (p<0.001) improvement in the assessed outcomes of group C in the post-intervention settings when compared to the other groups. After 4 weeks of intervention, the mean (SD) of FFI in groups A, B, and C were (64.54±4.91, 61.93±4.17, and 45.16±4.57) respectively, and the active range of motion (ROM) of the ankle dorsiflexion were (35.27±3.22, 36.59±2.91, and 41.85±3.04) respectively. The addition of RSW to US with the conventional physical therapy program improved foot function and ankle dorsiflexion range of motion significantly for patients with chronic plantar fasciitis.

Crack Damage Propagation and Morphology Distribution of Hydraulic Electric Pulse Fractured Coal.

This work discusses the damage and failure effect of a hydraulic electric pulse and the law of crack growth on coal. The impact and failure effect of a water shock wave and the mechanism of crack initiation, propagation, and arrest were studied by numerical simulation and the fracturing test of coal, combined with CT scanning, PCAS software, and Mimics 3D reconstruction technology. The results show that a high voltage electric pulse that increases permeability is an effective artificial crack making technology. The crack spreads radially along the borehole, and the damage degree, number, and complexity were positively correlated with the discharge voltage and discharge times. The crack area, volume, damage factor, and other parameters increased steadily. The cracks in the coal first start from two symmetrical angles, and finally distribute in a 360 deg circumferential direction, forming a multiangle crack spatial network structure. The fractal dimension of the crack group increases, the number of microcracks and the roughness of the crack group increases, the overall fractal dimension of the specimen decreases, and the roughness between cracks weakens. The cracks then form a smooth coal-bed methane migration channel. The research results can provide some theoretical guidance for the evaluation of crack damage propagation and the effect of electric pulse fracturing in water.

Effective combination of biocompatible zinc oxide nanocrystals and high-energy shock waves for the treatment of colorectal cancer

BackgroundColorectal cancer (CRC) is the third most diagnosed tumor worldwide, with a very high mortality rate, second only to lung cancer. Current treatments, such as surgery, chemotherapy or radiotherapy, are not effective enough and show several limitations. Among the emerging strategies, nanomedicine offers very powerful tools in cancer treatment. Recently, the combination of nanoparticle antitumor effect with a triggering external stimulation was formulated to boost up the cytotoxic activity.ResultsIn this work, we show the synergistic effect of oleic acid-capped zinc oxide nanocrystals (ZnO NCs) and mechanical high-energy shock waves (SW) in the treatment for CRC cells, in vitro. We tested two different types of ZnO NCs synthetized in our laboratory, the basal undoped ZnO NCs and the iron-doped ones (Fe:ZnO NCs). The presence of the oleic acid capping and the further amino-propyl functionalization guarantee a high colloidal stability to both NCs, while the iron doping confers to Fe:ZnO NCs interesting magnetic properties useful for imaging applications in a clinical perspective. Thus, the iron-doped ZnO NCs are very attractive as potentially theranostic nanoparticles, allowing both stimuli-responsive therapy and magnetic resonance imaging.Importantly, two colon adenocarcinoma cell lines, the HT-29 and the Dukes’ type C Colo 320DM cells were tested, both showing a good bio-tolerance and internalization rates of NCs. With the aim of eradicating the CRC cells, the possible synergism between the undoped/iron-doped ZnO NCs and an external physical stimulus, i.e., high-energy SW, was then here investigated in vitro. We demonstrated that the combined treatment resulted in an augmentation of the antitumor activity, especially for Colo 320DM cells, when compared to controls. Moreover, a repeated and sequenced SW treatment (three times/day, 3SW) after ZnO NCs exposure resulted in a further increased mortality of CRC cells.ConclusionOur work proposes the combination of the cytotoxic activity of ZnO NCs with the SW external stimulation to obtain a booster of the antitumor activity, which warrants further investigation in vivo on CRC as well as on other tumors.Graphical

Effect of shock wave on nucleation and droplet growth of CO2 in flue gas in supersonic separators

To reduce carbon emissions caused by fossil fuel combustion, this work evaluates a potential carbon capture method. Based on heat transfer theory, aerodynamics and condensation dynamics, a mathematical model is proposed to depict the nonequilibrium condensation of CO2 in flue gas (N2–CO2). The interaction between shock wave and non-equilibrium condensation is clarified. The results show that when the shock wave enters nucleation area, the nucleation process is rapidly terminated and droplet growth process disappears. After the shock wave, the supersaturation decreases rapidly from 2.26 to 0.19, the gas changes from supersaturated state to unsaturated state, and the system returns to the thermodynamic equilibrium state. When the shock wave appears in the droplet growth area, there is a complete nucleation process. The gas molecules in front of the shock wave form stable droplets and release latent heat, leading to the fluctuation of temperature and pressure. After the shock wave, the droplet growth environment is destroyed, resulting in droplet radius and liquid content drop to 0. Increasing CO2 content can not only reduce the impact of shock wave on flows, but also strengthen the heat and mass transfer, and obtain larger droplet radius and higher liquid content.