Sonic Waves Research Articles

ULTRA SONIC RANGE FINDING FOR DISTANCE MEASURING IN COAL MINING

Measuring distances has always been a challenge in coal mines as it involves a lot of risks and disturbances. One method to measure the distances without any hindrances in sensitive places like coal mines is via Ultra Sonic waves which generates 40 KHz sound pulse that travels with the speed of sound to the object and returns it echo that helps in calculating the distance, which further display on the LCD display. The medium required here is air medium. This project performs the distance measuring techniques, required in coal mines. This technique is proven to be very helpful in places where human reach is not possible or difficult.

Combining digital speckle pattern interferometry with shearography in a new instrument to characterize surface delamination in museum artefacts

Abstract Digital speckle-shearing-pattern interferometry (DSSPI) combined with digital speckle pattern interferometry (DSPI) were used to document the state of preservation of 8th to 14th century wall paintings of Christian Nubia. The original plasters of the paintings were multilayer inhomogeneous structures cracked in some parts. They were removed from the cathedral in Faras, Sudan, between 1961 and 1964 as part of efforts to rescue archaeological works threatened by flooding and are now held in the collection of the National Museum in Warsaw. Delaminated areas in surfaces of the paintings were detected by inducing surface vibrations with a sonic wave of varying frequency emitted from a loudspeaker. DSPI allowed the size of the areas and vibration resonant frequencies to be characterized, whereas DSSPI was successful in obtaining the spatial distribution of the vibration amplitude with sub-micrometre accuracy as a function of the sound frequency used. The procedure provided precise, detailed and reproducible information on the character of each damaged area in spite of the considerable size of the paintings and the unstable out-of-lab conditions of a conservation studio in which the measurements were carried out. The obtained results will be used as a reference for future surveys of the paintings in order to trace the possible development of surface detachments, even at an incipient stage, which cannot be easily detected by the naked eye or manual inspection.

Estimation of uncertainty in sonic porosity using microcomputerized tomography images

Abstract Acoustic log uses sonic wave characteristics and transit time for the determination of porosity, lithology, and mechanical properties. Pearson correlation coefficients show velocity to be strongly dependent on porosity, mean pore size and its sphericity. Wyllie equation is widely used for relating compressional velocity and porosity. The equation does not consider effect of pore, grain morphology which makes it simple, but results in significant uncertainties. It underestimates velocity of Berea sandstone compared to computed velocities from microcomputerized tomography simulation. An increase in accuracy of Wyllie equation has been observed when correction related to effect of average pore size is incorporated.

Biophysical properties of Striae Distensae evaluated in vivo using non-invasive assays.

Striae Distensae (SD) or stretch marks are manifestations of epidermal atrophy that occurs after tissue tearing due to rapid growth or over-stretching and are characterized by distinct microstructural features. The objective of this in vivo study was to investigate the biophysical properties of SD lesions, including skin barrier function, skin surface hydration, mechanical properties, and chromophore concentrations, compared to normal adjacent skin. Non-invasive methods were used on 29 volunteers with SD to characterize: (i) visual appearance (visual assessment and clinical imaging), (ii) skin barrier function by measuring transepidermal water loss, (iii) skin surface hydration using corneometry (skin capacitance), (iv) mechanical properties measuring skin elasticity under vacuum and surface propagation of a sonic wave, (v) the presence of erythema and pigmentation using diffuse reflectance spectroscopy, and (vi) the levels of interleukin-1α on the skin surface. No difference was observed in skin barrier function and a slight difference in skin hydration between the striae and adjacent uninvolved skin. Viscoelasticity measurements showed that SD lesions were significantly less firm, less elastic, and less deformable than normal skin (P < 0.05). Mechanical anisotropy was increased in SD compared to normal skin, reflecting the skin surface anisotropy reported previously. Diffuse reflectance spectroscopy showed no differences in the apparent hemoglobin concentrations between SD and control. Skin pigmentation and light scattering values were significantly lower in SD (P < 0.001) compared to adjacent skin and there was no correlation between them indicating independent causes: lower melanin production for pigmentation and altered collagen fiber structure in the dermis for light scattering. Based on these results, the distinct microstructural features characterizing SD lesions are accompanied by changes in the mechanical and optical properties. These changes however do not seem to affect the skin barrier and moisturization properties.

Tests of new in-situ seabed acoustic measurement system in Qingdao

A new in-situ seabed acoustic measurement system is developed for direct in-situ measurement of sediment geoacoustic properties (compressional wave velocity and attenuation). The new in-situ system consists of two parts: the deck control unit and the underwater measurement unit. The underwater measurement unit emits sonic waves that propagate through the seafloor sediment, receives the returning signals, and transmits them to the deck control unit for waveform display and analysis. The entire operation is controlled and monitored in real time by the deck control unit on the research vessel and can provide recording of full waveforms to determine the sound velocity and attenuation. This paper outlines the design of the system, the measurement process, and demonstrates its application in tests carried out on seabed sediment off the Qingdao coast, China. The test results show that the system performed well and rapidly provided accurate in-situ acoustic velocity and attenuation estimates of the seafloor sediment.

Synthesis and characterization of bioactive glass particles using an ultrasound-assisted sol–gel process: Engineering the morphology and size of sonogels via a poly(ethylene glycol) dispersing agent

Sonochemical engineering is a relatively novel field involving the application of sonic and ultrasonic waves to chemical processing. Sonochemistry significantly enhances chemical reactions and mass transfer. Specifically, the application of ultrasound catalysis (sonocatalysis) to the sol–gel method gives rise to materials with new properties, known as sonogels. The effects of ultrasonic cavitation create a unique environment for sol–gel reactions, leading to the following particular features in the resulting gels: fine texture and more homogeneous structure. This study focused on obtaining Spherical Bioactive Glass Particles (SBGs) by the co-precipitation method in a diluted system using polyethylene glycol (PEG) as a dispersing agent that is assisted by ultrasonic catalysis. By this approach, it was possible to considerably reduce the solvent use and the gelation time and to engineer SBG particles with a well-defined morphology and narrow size distribution by adjusting the PEG chain length to modify the surface activity in the sol–gel reaction.

Reliability of sonic tomography to detect agarwood in Aquilaria microcarpa Baill.

Gaharu, or agarwood, is a valuable nontimber forest product. Due to its economic value, agarwood has been subjected to overexploitation in Indonesia’s natural forests. The traditional practice for harvesting agarwood is to fell trees without any reliable techniques for predicting that agarwood is present. Sonic tomography may represent a technique to detect agarwood in a tree before felling it. A study was conducted to evaluate the reliability of sonic tomography (Picus® sonic tomography) to detect agarwood within Aquilaria microcarpa trees. Thirty-five A. microcarpa trees (diameter ≥ 15 cm) at an experimental forest area in Carita, Banten Province, were selected as sample trees. Four to six transducers were placed at measuring points around the trunks of sample trees at 20, 130, and 200 cm from the ground. The transducers were connected to a software system that could record sonic wave velocities within each sample tree and then convert the data into colored images. The results showed that sound wave velocities within sample trees ranged from 400 to 900 m/s with average value 700 m/s. There were no significant differences of sonic wave velocities among measuring points. Sample trees with high sonic velocity tended to have dark-colored tomographic images (dark brown), while the lower sonic velocities were denoted by light colors (green, violet, blue). These results respectively corresponded to healthy and deteriorated conditions of the sample trees. In conclusion, sonic tomography shows sufficient reliability to detect the presence of agarwood in trees.

Underwater Sonar Signals Recognition by Incremental Data Stream Mining with Conflict Analysis

Sonar signals recognition is an important task in detecting the presence of some significant objects under the sea. In military, sonar signals are used in lieu of visuals to navigate underwater and/or locate enemy submarines in proximity. In particular, classification algorithm in data mining has been applied in sonar signal recognition for recognizing the type of surfaces from which the sonar waves are bounced. Classification algorithms in traditional data mining approach offer fair accuracy by training a classification model with the full dataset, in batches. It is well known that sonar signals are continuous and they are collected as data streams. Although the earlier classification algorithms are effective in traditional batch training, it may not be practical for incremental classifier learning. Since sonar signal data streams can amount to infinity, the data preprocessing time must be kept to a minimum to fulfill the need for high speed. This paper presents an alternative data mining strategy suitable for the progressive purging of noisy data via fast conflict analysis from the data stream without the need to learn from the whole dataset at one time. Simulation experiments are conducted and superior results are observed in supporting the efficacy of the methodology.

Research of low boom and low drag supersonic aircraft design

Sonic boom reduction will be an issue of utmost importance in future supersonic transport, due to strong regulations on acoustic nuisance. The paper describes a new multi-objective optimization method for supersonic aircraft design. The method is developed by coupling Seebass–George–Darden (SGD) inverse design method and multi-objective genetic algorithm. Based on the method, different codes are developed. Using a computational architecture, a conceptual supersonic aircraft design environment (CSADE) is constructed. The architecture of CSADE includes inner optimization level and out optimization level. The low boom configuration is generated in inner optimization level by matching the target equivalent area distribution and actual equivalent area distribution. And low boom/low drag configuration is generated in outer optimization level by using NSGA-II multi-objective genetic algorithm to optimize the control parameters of SGD method and aircraft shape. Two objective functions, low sonic boom and low wave drag, are considered in CSADE. Physically reasonable Pareto solutions are obtained from the present optimization. Some supersonic aircraft configurations are selected from Pareto front and the optimization results indicate that the swept forward wing configuration has benefits in both sonic boom reduction and wave drag reduction. The results are validated by using computational fluid dynamics (CFD) analysis.

High definition ultrasound of the breast

We propose to develop high definition ultrasound (HD-US) based on a hemispherical synthetic aperture and backscattered sonic waves. This configuration will produce direct three-dimensional maps of ultrasound reflectivity of breast tissues and will display higher signal-to-noise, reduced speckle, and greater spatial resolution compared to ultrasound arrays based on linear or curved planar sampling apertures. Our prototype hemispherical array consists of four interdigitated sub-arrays, each having 128 discrete elements. Currently, this array is used to capture 3D photoacoustic images of the whole breast using a spiral scanning strategy to increase the field of view sufficiently to perform whole-breast screening—photoacoustic mammography (PAM). We will add a multiplexed pulser, pulse sequencer, and T/R switches to capture ultrasound reflectivity data sufficient to form a 3D ultrasound image using the same reconstruction strategy used in PAM. Full 3D image acquisition will take 1.7 min, the same as currently used for PAM data collection. HD-US will be combined with PAM to produce 3D images of soft tissue and microcalcifications. The 3D images will be co-registered with the PAM images of hemoglobin distribution in the breast using a single hemispherical transducer array.

Intrinsic Resonance Between Localized Oscillations in a Piezoelectric Crystal

Coupled sonic waves localized on dislocations in a piezoelectric crystal are investigated. The frequencies of in-phase and counter-phase oscillations in a system of two dislocations are found out. It is shown that due to the intrinsic resonance the oscillation energy is alternately concentrated near one dislocation or the other. The complete or partial energy exchange occurs, provided there is an arbitrary weak coupling in the system. As the interaction is decreased, the energy exchange between the dislocations is only slowed down.

Sonic Wave Band Gaps in Two-Dimensional Phononic Crystals Consisting of Hollow Mercury Columns Immersed in a Water Host, and Arranged in Simple Lattices

In this paper, band gaps for two-dimensional phononic crystals consisting of hollow square water columns immersed in a mercury host are investigated by plane-wave-expansion (PWE) method, in which cross sections of the scattering objects are hollow-square and hollow water columns are arranged in simple lattices (square, and triangular lattices). In order to regulate band gaps, we alter inner side lengths of hollow-square column, and change the filling ratio at the same time. From the results, It can be found that the band gap width and the number of the bad gaps can be changed by lattice shapes and corresponding filling fraction. This could be very useful in the design of phononic crystals band gaps and frequency filtering.

Experiment and Technical Research on Underwater Sonic Device Emitted by Electric Sparks with High Energy and Large Bandwidth

Combined with practical research project, a novel discharge method using high voltage pulsed power technology was put into practice for a special kind of underground sonic source device. The sonic source guaranteed large power as well as broad and thick sonic wave. Simulation as well as field test confirmed the correctness and effectiveness of the design method.

励磁音響効果に関する基礎的研究

励磁音響効果に関する基礎的研究

HRT 변화에 따른 미세입자 분리 특성

Fluid generated within the sonic or ultrasonic waves are reflected by the wall, while the opposite direction forming a predetermined sound wave to the acoustic standing wave is referred to. In this study, the frequency of 1.0 MHz and 2.0 MHz acoustic standing wave generation module is installed in a continuous particle separation device, the laminar flow of influent, taking into account the hydraulic retention time (HRT) in accordance with changes in particle separation characteristics investigated. Operation of a standing wave in the particle separation device about temperature is increased, but did not significantly affect the formation of standing waves. During operation, the HRT 1 hr frequency 1.0 MHz 2 hr, 4 hr longer as the particle separation efficiency (turbidity) were 64.1%, 70.0%, 74.3% and, 2.0 MHz has 58.0%, respectively, depending on HRT, 61.8%, 70.7% in the respectively. That is, the same frequency, the HRT treatment efficiency is 10% or more, depending on differences in generation and, 1.0 MHz frequency, 2 hr, 2.0 MHz 4 hr at about 70% or more of the processing efficiency can be maintained. Frequency of 1.0 MHz and 2.0 MHz operation at the same time, as a result, HRT 1 hr, 2 hr, 4 hr particle separation efficiency of 63.8%, respectively, 70.6%, 77.6%, rather than the generation of standing waves appear continuous HRT is affecting a lot of particles to separate could know.

A Fuzzy Logic Model for Predicting Dipole Shear Sonic Imager Parameters From Conventional Well Logs

Sonic wave velocities, including compressional, shear, and Stoneley, are functional and practical parameters for various branches of reservoir characterization. In the last few years, several tools such as the dipole shear sonic imager (DSI) were introduced for measuring sonic wave velocities. Most of these instruments are expensive and drilling companies do not run them in all wells of a field because of economical restrictions. In this study, an accurate, intelligent, and indirect method was presented for prediction of sonic wave velocities, which are directly obtained from dipole shear sonic log, utilizing conventional well log data and fuzzy logic technique. Furthermore, the proposed methodology was applied on a carbonate reservoir of Iran. The results of the case study demonstrated the capabilities of fuzzy logic for estimation of sonic wave velocities, where DSI may not be run. The MSEs of the predicted Vp, Vs , and Vst in the test data calculated 1.47 (US/F), 4.96 (US/F), and 2.219 (US/F), respectively, which correspond to the R 2 values of 91.8%, 89.3%, and 90.4%, respectively.

Nonlinear electron acoustic waves in presence of shear magnetic field

Nonlinear electron acoustic waves are studied in a quasineutral plasma in the presence of a variable magnetic field. The fluid model is used to describe the dynamics of two temperature electron species in a stationary positively charged ion background. Linear analysis of the governing equations manifests dispersion relation of electron magneto sonic wave. Whereas, nonlinear wave dynamics is being investigated by introducing Lagrangian variable method in long wavelength limit. It is shown from finite amplitude analysis that the nonlinear wave characteristics are well depicted by KdV equation. The wave dispersion arising in quasineutral plasma is induced by transverse magnetic field component. The results are discussed in the context of plasma of Earth's magnetosphere.

English

Uterine leiomyomas are the most common benign tumors in women of child bearing age. They can cause symptoms including dysmenorrhoea, menorrhagia urinary symptoms and infertility. MR guided focused ultrasound is a non-invasive treatment approach for symptomatic uterine fibroids. We present a case of uterine fibroids treated with MRgFUS showing good symptomatic relief and lesion regression at six months follow up. INTRODUCTION: Uterine leiomyomas are common benign gynecological disorders that affect women in reproductive age group causing a significant impact on a woman’s health and quality of life. Hysterectomy which eliminates the source of underlying symptoms is a common approach to treating leiomyomas. Less invasive approaches such as myomectomy, uterine artery embolization and hormonal therapy have been shown to alleviate symptoms. MRgFUS is the only truly noninvasive technique for treatment of these conditions. In clinical trials MRgFUS resulted in significant relief of symptoms due to fibroids and focal adenomyosis. Our case report demonstrates the successful use of MRgFUS to treat symptomatic uterine fibroids. CASE: This patient was a 49 year old multiparous woman with complaints of menorrhagia and metrorrhagia. Her symptom severity score (on the score of 0-100 Scale of the UFS – QoL, questionnaire1 was 48 points. .MRI showed an anterior wall and fundal intramural fibroid measuring 5.6x5.1x5.7cms (volume 76cc). The fibroid was hypointense to myometrium on T2W images (fig. 1 A&B). Post-gadolinium contrast images showed moderate heterogenous enhancement (fig. 1C). After obtaining written consent from the patient, treatment was performed using the ExAblate 2000 system (Insightec, Hafia, Israel) and SIGNA HDxt 1.5T MRI (GE Healthcare, Milwaukee, U.S.A) On the day of treatment patient was administered conscious sedation (one ampoule of Fentanyl) to reduce motion during the procedure. A urinary catheter was inserted and bowels were mitigated using a rectal balloon (fig. 1 D). The fibroid was treated using a total number of 28 sonication spots and treatment duration was 50 minutes (from first to last sonication) (fig. 1 E-H) Mean energy was 2045 joules and frequency of sonication waves was 1.15 M. Temperature achieved was in the range of 60-85°C. Post treatment contrast enhanced SPGR sequences were acquired which showed a non-perfused volume of 72cc (fig. 1I &J) achieving an NPV ratio of 95%. Immediate post treatment period was uneventful and patient was discharged after removal of urinary catheter and rectal balloon. The patient was comfortable and returned to her daily routine the next day. On follow up after 6months there was significant alleviation of symptoms and her symptom severity score was reduced to 20. Follow up MRI showed a decrease in dimensions of the fibroid in all three planes. It measured 4.5x4.2x4.7cms (fig.1K&L).

ChemInform Abstract: On the Mechanochemical Activation by Ultrasound

AbstractReview: 60 refs.

Proximal tibial strain in medial unicompartmental knee replacements

As many as 25% to 40% of unicompartmental knee replacement (UKR) revisions are performed for pain, a possible cause of which is proximal tibial strain. The aim of this study was to examine the effect of UKR implant design and material on cortical and cancellous proximal tibial strain in a synthetic bone model. Composite Sawbone tibiae were implanted with cemented UKR components of different designs, either all-polyethylene or metal-backed. The tibiae were subsequently loaded in 500 N increments to 2500 N, unloading between increments. Cortical surface strain was measured using a digital image correlation technique. Cancellous damage was measured using acoustic emission, an engineering technique that detects sonic waves ('hits') produced when damage occurs in material. Anteromedial cortical surface strain showed significant differences between implants at 1500 N and 2500 N in the proximal 10 mm only (p < 0.001), with relative strain shielding in metal-backed implants. Acoustic emission showed significant differences in cancellous bone damage between implants at all loads (p = 0.001). All-polyethylene implants displayed 16.6 times the total number of cumulative acoustic emission hits as controls. All-polyethylene implants also displayed more hits than controls at all loads (p < 0.001), more than metal-backed implants at loads ≥ 1500 N (p < 0.001), and greater acoustic emission activity on unloading than controls (p = 0.01), reflecting a lack of implant stiffness. All-polyethylene implants were associated with a significant increase in damage at the microscopic level compared with metal-backed implants, even at low loads. All-polyethylene implants should be used with caution in patients who are likely to impose large loads across their knee joint.