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Sample records for ultrasonic microbubble destruction

  1. Ultrasonic destruction of albumin microbubbles enhances gene transfection and expression in cardiac myocytes.

    Science.gov (United States)

    Wang, Guo-zhong; Liu, Jing-hua; Lü, Shu-zheng; Lü, Yun; Guo, Cheng-jun; Zhao, Dong-hui; Fang, Dong-ping; He, Dong-fang; Zhou, Yuan; Ge, Chang-jiang

    2011-05-01

    It has been proven that ultrasonic destruction of microbubbles can enhance gene transfection efficiency into the noncardiac cells, but there are few reports about cardiac myocytes. Moreover, the exact mechanisms are not yet clear; whether the characteristic of microbubbles can affect the gene transfection efficiency or not is still controversial. This study was designed to investigate whether the ultrasound destruction of gene-loaded microbubbles could enhance the plasmids carried reporter gene transfection in primary cultured myocardial cell, and evaluate the effects of microbubbles characteristics on the transgene expression in cardiac myocytes. The β-galactosidase plasmids attached to the two types of microbubbles, air-contained sonicated dextrose albumin (ASDA) and perfluoropropane-exposed sonicated dextrose albumin (PESDA) were prepared. The gene transfection into cardiac myocytes was performed in vitro by naked plasmids, ultrasound exposure, ultrasonic destruction of gene-loaded microbubbles and calcium phosphate precipitation, and then the gene expression and cell viability were analyzed. The ultrasonic destruction of gene-loaded microbubbles enhanced gene expression in cardiac myocytes compared with naked plasmid transfection ((51.95 ± 2.41) U/g or (29.28 ± 3.65) U/g vs. (0.84 ± 0.21) U/g, P ASDA ((51.95 ± 2.41) U/g vs. (29.28 ± 3.65) U/g, P < 0.05). Ultrasonic destruction of microbubbles during calcium phosphate precipitation gene transfection enhanced β-galactosidase activity nearly 8-fold compared with calcium phosphate precipitation gene transfection alone ((111.35 ± 11.21) U/g protein vs. (14.13 ± 2.58) U/g protein, P < 0.01). Even 6 hours after calcium phosphate precipitation gene transfection, ultrasound-mediated microbubbles destruction resulted in more intense gene expression ((35.63 ± 7.65) U/g vs. (14.13 ± 2.58) U/g, P < 0.05). Ultrasonic destruction of microbubbles might be a promising method for the delivery of non-viral DNA into

  2. Association schemes perspective of microbubble cluster in ultrasonic fields.

    Science.gov (United States)

    Behnia, S; Yahyavi, M; Habibpourbisafar, R

    2018-06-01

    Dynamics of a cluster of chaotic oscillators on a network are studied using coupled maps. By introducing the association schemes, we obtain coupling strength in the adjacency matrices form, which satisfies Markov matrices property. We remark that in general, the stability region of the cluster of oscillators at the synchronization state is characterized by Lyapunov exponent which can be defined based on the N-coupled map. As a detailed physical example, dynamics of microbubble cluster in an ultrasonic field are studied using coupled maps. Microbubble cluster dynamics have an indicative highly active nonlinear phenomenon, were not easy to be explained. In this paper, a cluster of microbubbles with a thin elastic shell based on the modified Keller-Herring equation in an ultrasonic field is demonstrated in the framework of the globally coupled map. On the other hand, a relation between the microbubble elements is replaced by a relation between the vertices. Based on this method, the stability region of microbubbles pulsations at complete synchronization state has been obtained analytically. In this way, distances between microbubbles as coupling strength play the crucial role. In the stability region, we thus observe that the problem of study of dynamics of N-microbubble oscillators reduce to that of a single microbubble. Therefore, the important parameters of the isolated microbubble such as applied pressure, driving frequency and the initial radius have effective behavior on the synchronization state. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. [Destruction of synovial pannus of antigen-induced arthritis by ultrasonic cavitation in rabbits].

    Science.gov (United States)

    Zhang, Ling-yan; Qiu, Li; Wang, Lei; Lin, Ling; Wen, Xiao-rong

    2011-11-01

    To optimize the conditions of ultrasonic irradiation and microbubble of ultrasound cavitation on destruction of synovial pannus of antigen-induced arthritis (AIA) in rabbits. Antigen-induced arthritis was successfully induced on bilateral knee joints of 85 rabbits. Each 10 AIA rabbits were divided into two groups to compare various peak negative pressures, different ultrasonic pulse durations, various pulse repetition frequencies, different irradiance duration, different dosages of microbubble contrast agents, different ultrasonic irradiance times. With intravenous infusion of Sonovue to the rabbits, ultrasonic irradiance was performed on the right knee joint using the above condition of ultrasound cavitation. At the day 1 after ultrasonic irradiance, MRI and pathological examination were employed to evaluate the optimal conditions. The optimal parameters and conditions for ultrasonic irradiance included intermittent ultrasonic application (in 6 s intervals), 0.6 mL/kg of microbubble contrast agent, 4.6 MPa of ultrasonic peak negative pressure, 100 cycles of pulse duration, 50 Hz of pulse repetition frequency, 5 min of ultrasonic duration, 0.6 mL/kg of dosages of microbubble contrast agents and multi-sessional ultrasonic irradiance. After the ultrasonic irradiance, the thickness of right knee synovium measured by MRI was thinner than that of left knee and synovial necrosis was confirmed by the pathological finding. Under optimal ultrasonic irradiation and microbubble conditions, ultrasonic cavitation could destroy synovial pannus of AIA in rabbits.

  4. Ultrasound-targeted microbubble destruction enhances naked plasmid DNA transfection in rabbit Achilles tendons in vivo.

    Science.gov (United States)

    Qiu, L; Zhang, L; Wang, L; Jiang, Y; Luo, Y; Peng, Y; Lin, L

    2012-07-01

    The study was to investigate the probability of increasing the transfection of the gene in tendons by ultrasound-targeted microbubble destruction (UTMD), and to search for the most suitable transfection conditions. A mixture of microbubbles and enhanced green fluorescent protein (EGFP) plasmids was injected into rabbit Achilles tendons by different administration routes and the tendons were ultrasound pulse by different ultrasonic conditions in order to determine the most appropriate conditions. Then, the rabbits were divided into four groups: (1) ultrasound + microbubbles + plasmid; (2) ultrasound+ plasmid; (3) microbubble + plasmid; (4) plasmid only. EGFP expression in the tendons and other tissues, and the damage to tendon and paratenon were all observed. The results showed that EGFP expression in the tendon was higher by ultrasound pulse with 2 W cm(-2) of output intensity and a 20% duty cycle for 10 min. Local injection was determined to be the better administration route. Among the four groups, EGFP expression in Group 1 was higher than that in other groups. EGFP expression was highest on seventh day, then it gradually decrease over time, and lasted more than 56 days. EGFP expression was not found in other tissues. There was no obvious injury caused by UTMD. Under suitable conditions, it is feasible to use UTMD as a safe and effective gene transfection therapy for tendon injuries.

  5. Introduction to the ultrasound targeted microbubble destruction technique.

    Science.gov (United States)

    Walton, Chad B; Anderson, Cynthia D; Boulay, Rachel; Shohet, Ralph V

    2011-06-12

    In UTMD, bioactive molecules, such as negatively charged plasmid DNA vectors encoding a gene of interest, are added to the cationic shells of lipid microbubble contrast agents. In mice these vector-carrying microbubbles can be administered intravenously or directly to the left ventricle of the heart. In larger animals they can also be infused through an intracoronary catheter. The subsequent delivery from the circulation to a target organ occurs by acoustic cavitation at a resonant frequency of the microbubbles. It seems likely that the mechanical energy generated by the microbubble destruction results in transient pore formation in or between the endothelial cells of the microvasculature of the targeted region. As a result of this sonoporation effect, the transfection efficiency into and across the endothelial cells is enhanced, and transgene-encoding vectors are deposited into the surrounding tissue. Plasmid DNA remaining in the circulation is rapidly degraded by nucleases in the blood, which further reduces the likelihood of delivery to non-sonicated tissues and leads to highly specific target-organ transfection.

  6. Unilateral Opening of Rat Blood-Brain Barrier Assisted by Diagnostic Ultrasound Targeted Microbubbles Destruction.

    Science.gov (United States)

    Xu, Yali; Cui, Hai; Zhu, Qiong; Hua, Xing; Xia, Hongmei; Tan, Kaibin; Gao, Yunhua; Zhao, Jing; Liu, Zheng

    2016-01-01

    Objective. Blood-brain barrier (BBB) is a key obstacle that prevents the medication from blood to the brain. Microbubble-enhanced cavitation by focused ultrasound can open the BBB and proves to be valuable in the brain drug delivery. The study aimed to explore the feasibility, efficacy, and safety of unilateral opening of BBB using diagnostic ultrasound targeted microbubbles destruction in rats. Methods. A transtemporal bone irradiation of diagnostic ultrasound and intravenous injection of lipid-coated microbubbles were performed at unilateral hemisphere. Pathological changes were monitored. Evans Blue extravasation grades, extraction from brain tissue, and fluorescence optical density were quantified. Lanthanum nitrate was traced by transmission electron microscopy. Results. After diagnostic ultrasound mediated microbubbles destruction, Evans Blue extravasation and fluorescence integrated optical density were significantly higher in the irradiated hemisphere than the contralateral side (all p ultrasound-exposed hemisphere (4 ± 1, grade 2) while being invisible in the control side. Lanthanum nitrate tracers leaked through interendothelial cleft and spread to the nerve fiber existed in the irradiation side. Conclusions. Transtemporal bone irradiation under DUS mediated microbubble destruction provides us with a more accessible, safer, and higher selective BBB opening approach in rats, which is advantageous in brain targeted drugs delivery.

  7. Unilateral Opening of Rat Blood-Brain Barrier Assisted by Diagnostic Ultrasound Targeted Microbubbles Destruction

    Directory of Open Access Journals (Sweden)

    Yali Xu

    2016-01-01

    Full Text Available Objective. Blood-brain barrier (BBB is a key obstacle that prevents the medication from blood to the brain. Microbubble-enhanced cavitation by focused ultrasound can open the BBB and proves to be valuable in the brain drug delivery. The study aimed to explore the feasibility, efficacy, and safety of unilateral opening of BBB using diagnostic ultrasound targeted microbubbles destruction in rats. Methods. A transtemporal bone irradiation of diagnostic ultrasound and intravenous injection of lipid-coated microbubbles were performed at unilateral hemisphere. Pathological changes were monitored. Evans Blue extravasation grades, extraction from brain tissue, and fluorescence optical density were quantified. Lanthanum nitrate was traced by transmission electron microscopy. Results. After diagnostic ultrasound mediated microbubbles destruction, Evans Blue extravasation and fluorescence integrated optical density were significantly higher in the irradiated hemisphere than the contralateral side (all p<0.01. Erythrocytes extravasations were demonstrated in the ultrasound-exposed hemisphere (4±1, grade 2 while being invisible in the control side. Lanthanum nitrate tracers leaked through interendothelial cleft and spread to the nerve fiber existed in the irradiation side. Conclusions. Transtemporal bone irradiation under DUS mediated microbubble destruction provides us with a more accessible, safer, and higher selective BBB opening approach in rats, which is advantageous in brain targeted drugs delivery.

  8. Ultrasound Mediated Microbubbles Destruction Augmented Sonolysis: An In Vitro and In Vivo Study.

    Science.gov (United States)

    Cui, Hai; Zhu, Qiong; Gao, Yunhua; Xia, Hongmei; Tan, Kaibin; He, Ying; Liu, Zheng; Xu, Yali

    2017-01-01

    This study was aimed at exploring ultrasound mediated microbubbles destruction (UMMD) assisted sonolysis in both the in vitro and in vivo clots. Therapeutic ultrasound (TUS) and lipid microbubbles (MBs) were used in whole blood clots and divided into the control, TUS group, and TUS + MB group. Thrombolytic rates and microscopy were performed. Color Doppler flow imaging (CDFI) and angiography were performed to evaluate the recanalization rates and flow scores in femoral arterial thrombus (FAT) in rabbits. FAT were dyed with H&E. The average thrombolytic ratios of TUS + MB group were significantly higher than those of TUS group and the control group (both P cavitation via UMMD.

  9. Relaxation behavior of a microbubble under ultrasonic field

    International Nuclear Information System (INIS)

    Kang, Sarng Woo; Kwak, Ho Young

    2000-01-01

    Nonlinear oscillation of a microbubble under ultrasound was investigated theoretically. The bubble radius-time curves calculated by the Rayleigh-Plesset equation with a polytropic index and by the Keller-Miksis equation with the analytical solution for the Navier-Stokes equations of the gases were compared with the observed results by the light scattering method. This study has revealed that the bubble behavior such as the expansion ratio and the bouncing motion after the first collapse under ultrasound depends crucially on the retarded time of the bubble motion to the applied ultrasound

  10. Ablation of synovial pannus using microbubble-mediated ultrasonic cavitation in antigen-induced arthritis in rabbits.

    Science.gov (United States)

    Qiu, Li; Jiang, Yong; Zhang, Lingyan; Wang, Lei; Luo, Yan

    2012-12-01

    To investigate the ablative effectiveness of microbubble-mediated ultrasonic cavitation for treating synovial pannus and to determine a potential mechanism using the antigen-induced arthritis model (AIA). Ultrasonic ablation was performed on the knee joints of AIA rabbits using optimal ultrasonic ablative parameters. Rabbits with antigen-induced arthritis were randomly assigned to 4 groups: (1) the ultrasound (US) + microbubble group; (2) the US only group; (3) the microbubble only group, and (4) the control group. At 1 h and 14 days after the first ablation, contrast-enhanced ultrasonography (CEUS) monitoring and pathology synovitis score were used to evaluate the therapeutic effects. Synovial necrosis and microvascular changes were also measured. After the ablation treatment, the thickness of synovium and parameters of time intensity curve including derived peak intensity and area under curve were measured using CEUS, and the pathology synovitis score in the ultrasound + microbubble group was significantly lower than that found in the remaining groups. No damage was observed in the surrounding normal tissues. The mechanism underlying the ultrasonic ablation was related to microthrombosis and microvascular rupture that resulted in synovial necrosis. The results suggest that microbubble-mediated ultrasonic cavitation should be applied as a non-invasive strategy for the treatment of synovial pannus in arthritis under optimal conditions.

  11. Ultrasonic microbubble contrast agents and the transplant kidney

    Energy Technology Data Exchange (ETDEWEB)

    Kay, D.H., E-mail: davidhkay@doctors.org.u [Department of Radiology, Western Infirmary, Glasgow (United Kingdom); Mazonakis, M.; Geddes, C. [Department of Renal Medicine, Western Infirmary, Glasgow (United Kingdom); Baxter, G. [Department of Radiology, Western Infirmary, Glasgow (United Kingdom)

    2009-11-15

    Aim: To evaluate the potential application of microbubble agents in the immediate post-transplant period, by studying contrast uptake and washout, and to correlate these values with clinical indices, and thus, assess the potential prognostic value of this technique. Materials and methods: The study group comprised 20 consecutive renal transplant patients within 7 days of transplantation. Sonovue was administered as an intravenous bolus with continuous imaging of the transplant kidney at low mechanical index (MI) for 1 min post-injection. These data were analysed off-line by two observers, and time intensity curves (TIC) for the upper, mid, and lower poles constructed. Within each pole, a region of interest (5 mm square) was placed over the cortex, medullary pyramid, and interlobar artery, resulting in a total of nine TIC for each patient. TIC parameters included the arrival time (AT), time to peak (TTP), peak intensity (Max), gradient of the slope (M), and the area under curve (AUC). Results: For both observers there was good agreement for all values measured from the cortex and medulla, but poor interobserver correlation for the vascular values. In addition, there was only agreement for these values in the upper and mid-pole of the transplant with poor agreement for the lower pole values. The mid-pole of the transplant kidney was chosen as the point of measurement for subsequent studies. Mid-pole values were correlated with clinical data and outcome over the 3-month post-transplant period. Renal microbubble perfusion correlated with the transplant estimated glomerular filtration rate (eGFR) at 3 months post-transplantation (p = 0.016). Discussion: In conclusion, this is the first study to confirm reproducibility of the Sonovue TIC data in transplant patients and to quantify regional variation and perfusion. The statistically significant estimates of transplant perfusion may be of future benefit to transplant recipients and potentially utilized as a prognostic tool

  12. Ultrasound-targeted microbubble destruction improves the low density lipoprotein receptor gene expression in HepG2 cells

    International Nuclear Information System (INIS)

    Guo Dongping; Li Xiaoyu; Sun, Ping; Tang Yibo; Chen Xiuying; Chen Qi; Fan Leming; Zang Bin; Shao Lizheng; Li Xiaorong

    2006-01-01

    Ultrasound-targeted microbubble destruction had been employed in gene delivery and promised great potential. Liver has unique features that make it attractive for gene therapy. However, it poses formidable obstacles to hepatocyte-specific gene delivery. This study was designed to test the efficiency of therapeutic gene transfer and expression mediated by ultrasound/microbubble strategy in HepG 2 cell line. Air-filled albumin microbubbles were prepared and mixed with plasmid DNA encoding low density lipoprotein receptor (LDLR) and green fluorescent protein. The mixture of the DNA and microbubbles was administer to cultured HepG 2 cells under variable ultrasound conditions. Transfection rate of the transferred gene and cell viability were assessed by FACS analysis, confocal laser scanning microscopy, Western blot analysis and Trypan blue staining. The result demonstrated that microbubbles with ultrasound irradiation can significantly elevate exogenous LDLR gene expression and the expressed LDLRs were functional and active to uptake their ligands. We conclude that ultrasound-targeted microbubble destruction has the potential to promote safe and efficient LDLR gene transfer into hepatocytes. With further refinement, it may represent an effective nonviral avenue of gene therapy for liver-involved genetic diseases

  13. Ultrasound Mediated Microbubbles Destruction Augmented Sonolysis: An In Vitro and In Vivo Study

    Directory of Open Access Journals (Sweden)

    Hai Cui

    2017-01-01

    Full Text Available Objective. This study was aimed at exploring ultrasound mediated microbubbles destruction (UMMD assisted sonolysis in both the in vitro and in vivo clots. Methods. Therapeutic ultrasound (TUS and lipid microbubbles (MBs were used in whole blood clots and divided into the control, TUS group, and TUS + MB group. Thrombolytic rates and microscopy were performed. Color Doppler flow imaging (CDFI and angiography were performed to evaluate the recanalization rates and flow scores in femoral arterial thrombus (FAT in rabbits. FAT were dyed with H&E. Results. The average thrombolytic ratios of TUS + MB group were significantly higher than those of TUS group and the control group (both P<0.05. Clots had different pathological changes. Recanalization rates and flow scores in TUS + MB group were significantly higher than the control and TUS group. Flow scores and recanalization ratios were grade 0 in 0% of the control group, grade I in 25% of TUS group, and grade II or higher in 87.5% of TUS + MB group after 30 min sonolysis. Conclusions. Both the in vitro and in vivo sonolysis can be significantly augmented by the introduction of MBs without thrombolytic agents, which might be induced by the enhanced cavitation via UMMD.

  14. Mathematical modelling of ultrasonic non-destructive evaluation

    Directory of Open Access Journals (Sweden)

    Larissa Ju Fradkin

    2001-01-01

    Full Text Available High-frequency asymptotics have been used at our Centre to develop codes for modelling pulse propagation and scattering in the near-field of the ultrasonic transducers used in NDE (Non-Destructive Evaluation, particularly of walls of nuclear reactors. The codes are hundreds of times faster than the direct numerical codes but no less accurate.

  15. Ultrasound Targeted Microbubble Destruction Stimulates Cellular Endocytosis in Facilitation of Adeno-Associated Virus Delivery

    Directory of Open Access Journals (Sweden)

    Lian-Fang Du

    2013-05-01

    Full Text Available The generally accepted mechanism for ultrasound targeted microbubble destruction (UTMD to enhance drug and gene delivery is through sonoporation. However, passive uptake of adeno-associated virus (AAV into cells following sonoporation does not adequately explain observations of enhanced transduction by UTMD. This study investigated alternative mechanisms of UTMD enhancement in AAV delivery. UTMD significantly enhanced transduction efficiency of AAV in a dose-dependent manner. UTMD stimulated a persistent uptake of AAV into the cytoplasm and nucleus. This phenomenon occurred over several hours, suggesting that some viral particles are endocytosed by cells rather than exclusively passing through pores created by sonoporation. Additionally, UTMD enhanced clathrin expression and accumulation at the plasma membrane suggesting greater clathrin-mediated endocytosis following UTMD. Transmission electron microscopy (TEM revealed that UTMD stimulated formation of clathrin-coated pits (CPs and uncoated pits (nCPs. Furthermore, inhibition of clathrin-mediated endocytosis partially blocked the enhancement of AAV uptake following UTMD. The results of this study implicate endocytosis as a mechanism that contributes to UTMD-enhanced AAV delivery.

  16. Sonodynamically-induced cytotoxicity by rose bengal derivative and microbubbles in isolated sarcoma 180 cells

    Science.gov (United States)

    Sugita, Nami; Hosokawa, Mami; Sunaga, Naoki; Iwase, Yumiko; Yumita, Nagahiko; Ikeda, Toshihiko; Umemura, Shin-ichiro

    2015-07-01

    It is known that the combination of ultrasound and sonodynamic sensitizer (SDS) is effective in noninvasive tumor treatment, referred to as sonodynamic therapy (SDT). Microbubbles have been used in ultrasound therapy as well. The purpose of this paper is to clarify the effect of microbubbles on SDT. Sarcoma 180 cells were suspended in air-saturated phosphate-buffered saline and exposed to ultrasound with the SDS rose bengal derivative (RBD) in standing wave mode in the presence and absence of microbubbles [sonazoid (SZ)]. The ultrasonically induced cytotoxicity with RBD and SZ was about 20 times higher than without either, and about 80% of the SZ microbubbles were destructed by ultrasonic exposure in as short as five seconds. Since microbubbles induce significant cytotoxicity even with short duration, low intensity ultrasound, the application of microbubbles in SDT shows promise in anti-tumor treatment.

  17. Targeted gene delivery to the synovial pannus in antigen-induced arthritis by ultrasound-targeted microbubble destruction in vivo.

    Science.gov (United States)

    Xiang, Xi; Tang, Yuanjiao; Leng, Qianying; Zhang, Lingyan; Qiu, Li

    2016-02-01

    The purpose of this study was to optimize an ultrasound-targeted microbubble destruction (UTMD) technique to improve the in vivo transfection efficiency of the gene encoding enhanced green fluorescent protein (EGFP) in the synovial pannus in an antigen-induced arthritis rabbit model. A mixture of microbubbles and plasmids was locally injected into the knee joints of an antigen-induced arthritis (AIA) rabbits. The plasmid concentrations and ultrasound conditions were varied in the experiments. We also tested local articular and intravenous injections. The rabbits were divided into five groups: (1) ultrasound+microbubbles+plasmid; (2) ultrasound+plasmid; (3) microbubble+plasmid; (4) plasmid only; (5) untreated controls. EGFP expression was observed by fluorescent microscope and immunohistochemical staining in the synovial pannus of each group. The optimal plasmid dosage and ultrasound parameter were determined based on the results of EGFP expression and the present and absent of tissue damage under light microscopy. The irradiation procedure was performed to observe the duration of the EGFP expression in the synovial pannus and other tissues and organs, as well as the damage to the normal cells. The optimal condition was determined to be a 1-MHz ultrasound pulse applied for 5 min with a power output of 2 W/cm(2) and a 20% duty cycle along with 300 μg of plasmid. Under these conditions, the synovial pannus showed significant EGFP expression without significant damage to the surrounding normal tissue. The EGFP expression induced by the local intra-articular injection was significantly more increased than that induced by the intravenous injection. The EGFP expression in the synovial pannus of the ultrasound+microbubbles+plasmid group was significantly higher than that of the other four groups (Ppannus of an AIA model. Thus, this could become a safe and effective non-viral gene transfection procedure for arthritis therapy. Copyright © 2015 Elsevier B.V. All rights

  18. Myocardial regeneration in adriamycin cardiomyopathy by nuclear expression of GLP1 using ultrasound targeted microbubble destruction

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shuyuan [Baylor Research Institute, Baylor University Medical Center, 3812 Elm Street, Dallas, TX (United States); Chen, Jiaxi [The University of Texas Southwestern Medical Center at Dallas, Medical School, 5235 Harry Hine Blvd., Dallas, TX (United States); Huang, Pintong [Department of Ultrasonography, The 2nd Affiliated Hospital of Zhejiang University College of Medicine, Hangzhou, Zhejiang Province (China); Meng, Xing-Li; Clayton, Sandra; Shen, Jin-Song [Baylor Research Institute, Baylor University Medical Center, 3812 Elm Street, Dallas, TX (United States); Grayburn, Paul A., E-mail: paulgr@baylorhealth.edu [Baylor Research Institute, Baylor University Medical Center, 3812 Elm Street, Dallas, TX (United States); Department of Internal Medicine, Division of Cardiology, Baylor Heart and Vascular Institute, Baylor University Medical Center, 621 N. Hall St, Suite H030, Dallas, TX (United States)

    2015-03-20

    Recently GLP-1 was found to have cardioprotective effects independent of those attributable to tight glycemic control. Methods and results: We employed ultrasound targeted microbubble destruction (UTMD) to deliver piggybac transposon plasmids encoding the GLP-1 gene with a nuclear localizing signal to rat hearts with adriamycin cardiomyopathy. After a single UTMD treatment, overexpression of transgenic GLP-1 was found in nuclei of rat heart cells with evidence that transfected cardiac cells had undergone proliferation. UTMD-GLP-1 gene therapy restored LV mass, fractional shortening index, and LV posterior wall diameter to nearly normal. Nuclear overexpression of GLP-1 by inducing phosphorylation of FoxO1-S256 and translocation of FoxO1 from the nucleus to the cytoplasm significantly inactivated FoxO1 and activated the expression of cyclin D1 in nuclei of cardiac muscle cells. Reversal of adriamycin cardiomyopathy appeared to be mediated by dedifferentiation and proliferation of nuclear FoxO1-positive cardiac muscle cells with evidence of embryonic stem cell markers (OCT4, Nanog, SOX2 and c-kit), cardiac early differentiation markers (NKX2.5 and ISL-1) and cellular proliferation markers (BrdU and PHH3) after UTMD with GLP-1 gene therapy. Conclusions: Intranuclear myocardial delivery of the GLP-1gene can reverse established adriamycin cardiomyopathy by stimulating myocardial regeneration. - Highlights: • The activation of nuclear FoxO1 in cardiac muscle cells associated with adriamycin cardiomyopathy. • Myocardial nuclear GLP-1 stimulates myocardial regeneration and reverses adriamycin cardiomyopathy. • The process of myocardial regeneration associated with dedifferentiation and proliferation.

  19. Myocardial regeneration in adriamycin cardiomyopathy by nuclear expression of GLP1 using ultrasound targeted microbubble destruction

    International Nuclear Information System (INIS)

    Chen, Shuyuan; Chen, Jiaxi; Huang, Pintong; Meng, Xing-Li; Clayton, Sandra; Shen, Jin-Song; Grayburn, Paul A.

    2015-01-01

    Recently GLP-1 was found to have cardioprotective effects independent of those attributable to tight glycemic control. Methods and results: We employed ultrasound targeted microbubble destruction (UTMD) to deliver piggybac transposon plasmids encoding the GLP-1 gene with a nuclear localizing signal to rat hearts with adriamycin cardiomyopathy. After a single UTMD treatment, overexpression of transgenic GLP-1 was found in nuclei of rat heart cells with evidence that transfected cardiac cells had undergone proliferation. UTMD-GLP-1 gene therapy restored LV mass, fractional shortening index, and LV posterior wall diameter to nearly normal. Nuclear overexpression of GLP-1 by inducing phosphorylation of FoxO1-S256 and translocation of FoxO1 from the nucleus to the cytoplasm significantly inactivated FoxO1 and activated the expression of cyclin D1 in nuclei of cardiac muscle cells. Reversal of adriamycin cardiomyopathy appeared to be mediated by dedifferentiation and proliferation of nuclear FoxO1-positive cardiac muscle cells with evidence of embryonic stem cell markers (OCT4, Nanog, SOX2 and c-kit), cardiac early differentiation markers (NKX2.5 and ISL-1) and cellular proliferation markers (BrdU and PHH3) after UTMD with GLP-1 gene therapy. Conclusions: Intranuclear myocardial delivery of the GLP-1gene can reverse established adriamycin cardiomyopathy by stimulating myocardial regeneration. - Highlights: • The activation of nuclear FoxO1 in cardiac muscle cells associated with adriamycin cardiomyopathy. • Myocardial nuclear GLP-1 stimulates myocardial regeneration and reverses adriamycin cardiomyopathy. • The process of myocardial regeneration associated with dedifferentiation and proliferation

  20. Non-destructive evaluation of concrete using ultrasonic pulse velocity

    International Nuclear Information System (INIS)

    Lawson, I.

    2008-06-01

    Ultrasonic pulse velocity is one of the most popular non-destructive techniques used in the assessment of concrete properties. This thesis investigates the relationship between using ultrasonic pulse velocity (UPV) and the conventional compressive strength tests to determine concrete uniformity. The specimens used in the studies were made of concrete with a paste content of 18% and the constituents of the specimens varied in different water-cement ratios (w/c). The UPV measurement and compressive strength tests were carried out at the concrete age of 2, 7, 15 and 28 days. The UPV and the compressive strength of concrete increase with age, but the growth rate varies with mixture proportion. A relationship curve is drawn between UPV and compressive strength for concrete having different w/c from 0.35 to 0.7. Tests were also performed using Ultrasonic Pulse Velocity Method (UPVM) in detecting discontinuity and determining its depth during the early age of concrete. The test results indicate that the UPVM can be used to assess the in-situ properties of concrete or for quality control on site. The accuracy of the UPVM in detecting discontinuities ranges from 55.75 to 98.70% for ages 3 to 28 (full strength) respectively. (au)

  1. High-Frequency Fiber-Optic Ultrasonic Sensor Using Air Micro-Bubble for Imaging of Seismic Physical Models.

    Science.gov (United States)

    Gang, Tingting; Hu, Manli; Rong, Qiangzhou; Qiao, Xueguang; Liang, Lei; Liu, Nan; Tong, Rongxin; Liu, Xiaobo; Bian, Ce

    2016-12-14

    A micro-fiber-optic Fabry-Perot interferometer (FPI) is proposed and demonstrated experimentally for ultrasonic imaging of seismic physical models. The device consists of a micro-bubble followed by the end of a single-mode fiber (SMF). The micro-structure is formed by the discharging operation on a short segment of hollow-core fiber (HCF) that is spliced to the SMF. This micro FPI is sensitive to ultrasonic waves (UWs), especially to the high-frequency (up to 10 MHz) UW, thanks to its ultra-thin cavity wall and micro-diameter. A side-band filter technology is employed for the UW interrogation, and then the high signal-to-noise ratio (SNR) UW signal is achieved. Eventually the sensor is used for lateral imaging of the physical model by scanning UW detection and two-dimensional signal reconstruction.

  2. Parallelization of ultrasonic field simulations for non destructive testing

    International Nuclear Information System (INIS)

    Lambert, Jason

    2015-01-01

    The Non Destructive Testing field increasingly uses simulation. It is used at every step of the whole control process of an industrial part, from speeding up control development to helping experts understand results. During this thesis, a fast ultrasonic field simulation tool dedicated to the computation of an ultrasonic field radiated by a phase array probe in an isotropic specimen has been developed. During this thesis, a simulation tool dedicated to the fast computation of an ultrasonic field radiated by a phased array probe in an isotropic specimen has been developed. Its performance enables an interactive usage. To benefit from the commonly available parallel architectures, a regular model (aimed at removing divergent branching) derived from the generic CIVA model has been developed. First, a reference implementation was developed to validate this model against CIVA results, and to analyze its performance behaviour before optimization. The resulting code has been optimized for three kinds of parallel architectures commonly available in workstations: general purpose processors (GPP), many-core co-processors (Intel MIC) and graphics processing units (nVidia GPU). On the GPP and the MIC, the algorithm was reorganized and implemented to benefit from both parallelism levels, multithreading and vector instructions. On the GPU, the multiple steps of field computing have been divided in multiple successive CUDA kernels. Moreover, libraries dedicated to each architecture were used to speedup Fast Fourier Transforms, Intel MKL on GPP and MIC and nVidia cuFFT on GPU. Performance and hardware adequation of the produced codes were thoroughly studied for each architecture. On multiple realistic control configurations, interactive performance was reached. Perspectives to address more complex configurations were drawn. Finally, the integration and the industrialization of this code in the commercial NDT platform CIVA is discussed. (author) [fr

  3. Ultrasonically induced dynamics of a contrast agent microbubble between two parallel elastic walls

    International Nuclear Information System (INIS)

    Doinikov, Alexander A; Bouakaz, Ayache

    2013-01-01

    This work presents the derivation of a Rayleigh–Plesset-like equation that describes the radial oscillation of a contrast agent microbubble between two elastic walls, assuming that the bubble is attached to one of them. The obtained equation is then used in numerical simulations in order to establish how the presence of the second wall affects the resonance properties and the scattered echo of the contrast microbubble. The effect of encapsulation on the dynamics of the microbubble is simulated by the Marmottant shell model which is commonly used for the modeling of the dynamics of lipid-shelled contrast agents. Two cases are examined. In the first, the mechanical properties of the walls are set to correspond to OptiCell chambers which are widely used in experiments on microbubble contrast agents. In the second, the properties of the walls correspond to walls of blood vessels. It is shown that the presence of the second wall increases the resonance frequency of the contrast microbubble and decreases the amplitudes of the radial oscillation and the scattered echo of the microbubble as compared to the case that the second wall is absent. It is also shown that the presence of the second wall can change noticeably the intensity of the second harmonic in the spectrum of the scattered pressure. It is demonstrated that, depending on the value of the driving frequency, the presence of the second wall can either increase or decrease the intensity of the second harmonic as compared to its intensity in the case that the second wall is absent. (paper)

  4. Training methods in non-destructive examination with ultrasonic testing

    International Nuclear Information System (INIS)

    Walte, F.

    1986-01-01

    German concept for inspection of LWR, leak before break, basic safety; General inspection methods; Ultrasonic inspection - basic principle, generation of ultrasound, bulk and surface waves, piezo electric and electromagnetic transducers, energy balance, scattering and adsorption, divergence; Ultra techniques in compliance with KTA-rules - pulse-echo, tandem, throughtransmission; Valuation of ultrasonic indications; Pre- and in-service inspection; Practical part - ultrasonic equipment, ultrasonic piezo electric transducers, wall thickness measurement, crack depth measurement with potential drop technique. (orig.)

  5. Ultrasonic process for destruction of chlorinated organic compounds in aqueous solution

    International Nuclear Information System (INIS)

    Wu, Jiann M.; Huang, Hann S.

    1993-01-01

    Laboratory investigations of the ultrasonic process for destruction of low concentrations of carbon tetrachloride (CCl 4 ) into nonhazardous end products were carried out in a bench-scale batch reactor, equipped with a 600-W ultrasonic power supply. Process parameters studied included irradiation time, concentration, steady-state operating temperature, pH, and the intensity of applied ultrasonic-wave energy. High destruction efficiencies of greater than 99% were achieved through this process, and the irradiation time and the intensity of applied energy were identified to be the most important process parameters. The irradiation time required for a given degree of destruction decreased with increasing intensity of the applied ultrasonic energy. In addition, a detailed chemical reaction mechanism for the destruction of CCl 4 in water was formulated. The agreement between the model and experimental results is generally good

  6. Ultrasound-targeted microbubble destruction enhances delayed BMC delivery and attenuates post-infarction cardiac remodelling by inducing engraftment signals.

    Science.gov (United States)

    Chen, Yanmei; Zhang, Chuanxi; Shen, Shuxin; Guo, Shengcun; Zhong, Lintao; Li, Xinzhong; Chen, Guojun; Chen, Gangbin; He, Xiang; Huang, Chixiong; He, Nvqin; Liao, Wangjun; Liao, Yulin; Bin, Jianping

    2016-12-01

    Delayed administration of bone marrow cells (BMCs) at 2-4 weeks after successful reperfusion in patients with acute myocardial infarction (MI) does not improve cardiac function. The reduction in engraftment signals observed following this time interval might impair the effects of delayed BMC treatment. In the present study, we aimed to determine whether ultrasound-targeted microbubble destruction (UTMD) treatment could increase engraftment signals, enhance the delivery of delayed BMCs and subsequently attenuate post-infarction cardiac remodelling. A myocardial ischaemia/reperfusion (I/R) model was induced in Wistar rats via left coronary ligation for 45 min followed by reperfusion. Western blotting revealed that engraftment signals peaked at 7 days post-I/R and were dramatically lower at 14 days post-I/R. The lower engraftment signals at 14 days post-I/R could be triggered by UTMD treatment at a mechanical index of 1.0-1.9. The troponin I levels in the 1.9 mechanical index group were higher than in the other groups. Simultaneous haematoxylin and eosin staining and fluorescence revealed that the number of engrafted BMCs in the ischaemic zone was greater in the group treated with both UTMD and delayed BMC transplantation than in the control groups (PBMC transplantation improved cardiac function and decreased cardiac fibrosis at 4 weeks after treatment, as compared with control groups (both PBMC transplantation increased capillary density, myocardial cell proliferation and c-kit + cell proliferation. These findings indicated that UTMD treatment could induce engraftment signals and enhance homing of delayed BMCs to ischaemic myocardium, attenuating post-infarction cardiac remodelling by promoting neovascularization, cardiomyogenesis and expansion of cardiac c-kit + cells. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

  7. On the possible ultrasonic inspection of micro-bubbles generated by the optical fiber tip

    Directory of Open Access Journals (Sweden)

    V. V. Kazakov

    2016-09-01

    Full Text Available We demonstrate the possibility of detection and monitoring of bubbles emerging near the tip of an optical fiber by means of ultrasonic method. The excitation of bubbles at their resonant frequencies is performed using short ultrasonic pulses having a wide frequency range simultaneously with their modulation by means of a long pulse of a monochromatic frequency. This method allows detection of bubbles of various sizes. Used signal processing method, which allows increased bubble detection accuracy, is proposed for research in environments of biological-like medium which show continuous variations in structure and properties when exposed to optical emission. The method has been demonstrated on model objects: in a liquid and in a biological tissue phantom using various methods of bubble generation (hydrolysis and optical emission. We studied bubble formation by the tip of a fiber of the surgical laser LSP-007/10 “IRE Polus” with a wavelength of 0.97μm coated with a highly absorbing graphite layer.

  8. Ultrasound-targeted stromal cell-derived factor-1-loaded microbubble destruction promotes mesenchymal stem cell homing to kidneys in diabetic nephropathy rats

    Directory of Open Access Journals (Sweden)

    Wu S

    2014-12-01

    Full Text Available Shengzheng Wu,1 Lu Li,1 Gong Wang,1 Weiwei Shen,2 Yali Xu,1 Zheng Liu,1 Zhongxiong Zhuo,1 Hongmei Xia,1 Yunhua Gao,1 Kaibin Tan1 1Department of Ultrasound, 2Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing, People’s Republic of China Abstract: Mesenchymal stem cell (MSC therapy has been considered a promising strategy to cure diabetic nephropathy (DN. However, insufficient MSCs can settle in injured kidneys, which constitute one of the major barriers to the effective implementation of MSC therapy. Stromal cell-derived factor-1 (SDF-1 plays a vital role in MSC migration and involves activation, mobilization, homing, and retention, which are presumably related to the poor homing in DN therapy. Ultrasound-targeted microbubble destruction has become one of the most promising strategies for the targeted delivery of drugs and genes. To improve MSC homing to DN kidneys, we present a strategy to increase SDF-1 via ultrasound-targeted microbubble destruction. In this study, we developed SDF-1-loaded microbubbles (MBSDF-1 via covalent conjugation. The characterization and bioactivity of MBSDF-1 were assessed in vitro. Target release in the targeted kidneys was triggered with diagnostic ultrasound in combination with MBSDF-1. The related bioeffects were also elucidated. Early DN was induced in rats with streptozotocin. Green fluorescent protein-labeled MSCs were transplanted intravenously following the target release of SDF-1 in the kidneys of normal and DN rats. The homing efficacy was assessed by detecting the implanted exogenous MSCs at 24 hours. The in vitro results showed an impressive SDF-1 loading efficacy of 79% and a loading content of 15.8 µg/mL. MBSDF-1 remained bioactive as a chemoattractant. In the in vivo study, SDF-1 was successfully released in the targeted kidneys. The homing efficacy of MSCs to DN kidneys after the target release of SDF-1 was remarkably ameliorated at 24 hours compared with

  9. Destruction of Molecules or Nuclei of Hazardous Substances in Ultrasonic Activator

    International Nuclear Information System (INIS)

    Kladov, A.

    1999-01-01

    The acceleration of chemical reactions by means of ultrasonic stress-long ago known at peace effect, but few utilized in industry due to it high price and the complexity of control. Firm ROSLO created simple and exceedingly effective device, in which you may carry out differential chemical and nuclear reactions. In given work are described the experimental events only of reactions of destruction on chemical and nuclear layers, and also is given the short-form intended explanation of occurring appearances

  10. Interactive ultrasonic field simulations for complex non-destructive testing configurations

    International Nuclear Information System (INIS)

    Chouh, Hamza

    2016-01-01

    In order to fulfill increasing reliability and safety requirements, non-destructive testing techniques are constantly evolving and so does their complexity. Consequently, simulation is an essential part of their design. We developed a tool for the simulation of the ultrasonic field radiated by any planar probes into non-destructive testing configurations involving meshed geometries without prominent edges, isotropic and anisotropic, homogeneous and heterogeneous materials, and wave trajectories that can include reflections and transmissions. We approximate the ultrasonic wave fronts by using polynomial interpolators that are local to ultrasonic ray pencils. They are obtained using a surface research algorithm based on pencil tracing and successive subdivisions. Their interpolators enable the computation of the necessary quantities for the impulse responses on each point of a sampling of the transducer surface that fulfills the Shannon criterion. By doing so, we can compute a global impulse response which, when convolved with the excitation signal of the transducer, results in the ultrasonic field. The usage of task parallelism and of SIMD instructions on the most computationally expensive steps yields an important performance boost. Finally, we developed a tool for progressive visualization of field images. It benefits from an image reconstruction technique and schedules field computations in order to accelerate convergence towards the final image. (author) [fr

  11. Engineering brown fat into skeletal muscle using ultrasound-targeted microbubble destruction gene delivery in obese Zucker rats: Proof of concept design.

    Science.gov (United States)

    Bastarrachea, Raul A; Chen, Jiaxi; Kent, Jack W; Nava-Gonzalez, Edna J; Rodriguez-Ayala, Ernesto; Daadi, Marcel M; Jorge, Barbara; Laviada-Molina, Hugo; Comuzzie, Anthony G; Chen, Shuyuan; Grayburn, Paul A

    2017-09-01

    Ultrasound-targeted microbubble destruction (UTMD) is a novel means of tissue-specific gene delivery. This approach systemically infuses transgenes precoupled to gas-filled lipid microbubbles that are burst within the microvasculature of target tissues via an ultrasound signal resulting in release of DNA and transfection of neighboring cells within the tissue. Previous work has shown that adenovirus containing cDNA of UCP-1, injected into the epididymal fat pads in mice, induced localized fat depletion, improving glucose tolerance, and decreasing food intake in obese diabetic mice. Our group recently demonstrated that gene therapy by UTMD achieved beta cell regeneration in streptozotocin (STZ)-treated mice and baboons. We hypothesized that gene therapy with BMP7/PRDM16/PPARGC1A in skeletal muscle (SKM) of obese Zucker diabetic fatty (fa/fa) rats using UTMD technology would produce a brown adipose tissue (BAT) phenotype with UCP-1 overexpression. This study was designed as a proof of concept (POC) project. Obese Zucker rats were administered plasmid cDNA contructs encoding a gene cocktail with BMP7/PRDM16/PPARGC1A incorporated within microbubbles and intravenously delivered into their left thigh. Controls received UTMD with plasmids driving a DsRed reporter gene. An ultrasound transducer was directed to the thigh to disrupt the microbubbles within the microcirculation. Blood samples were drawn at baseline, and after treatment to measure glucose, insulin, and free fatty acids levels. SKM was harvested for immunohistochemistry (IHC). Our IHC results showed a reliable pattern of effective UTMD-based gene delivery in enhancing SKM overexpression of the UCP-1 gene. This clearly indicates that our plasmid DNA construct encoding the gene combination of PRDM16, PPARGC1A, and BMP7 reprogrammed adult SKM tissue into brown adipose cells in vivo. Our pilot established POC showing that the administration of the gene cocktail to SKM in this rat model of genetic obesity using UTMD

  12. A Monte Carlo approach applied to ultrasonic non-destructive testing

    Science.gov (United States)

    Mosca, I.; Bilgili, F.; Meier, T.; Sigloch, K.

    2012-04-01

    Non-destructive testing based on ultrasound allows us to detect, characterize and size discrete flaws in geotechnical and architectural structures and materials. This information is needed to determine whether such flaws can be tolerated in future service. In typical ultrasonic experiments, only the first-arriving P-wave is interpreted, and the remainder of the recorded waveform is neglected. Our work aims at understanding surface waves, which are strong signals in the later wave train, with the ultimate goal of full waveform tomography. At present, even the structural estimation of layered media is still challenging because material properties of the samples can vary widely, and good initial models for inversion do not often exist. The aim of the present study is to combine non-destructive testing with a theoretical data analysis and hence to contribute to conservation strategies of archaeological and architectural structures. We analyze ultrasonic waveforms measured at the surface of a variety of samples, and define the behaviour of surface waves in structures of increasing complexity. The tremendous potential of ultrasonic surface waves becomes an advantage only if numerical forward modelling tools are available to describe the waveforms accurately. We compute synthetic full seismograms as well as group and phase velocities for the data. We invert them for the elastic properties of the sample via a global search of the parameter space, using the Neighbourhood Algorithm. Such a Monte Carlo approach allows us to perform a complete uncertainty and resolution analysis, but the computational cost is high and increases quickly with the number of model parameters. Therefore it is practical only for defining the seismic properties of media with a limited number of degrees of freedom, such as layered structures. We have applied this approach to both synthetic layered structures and real samples. The former contributed to benchmark the propagation of ultrasonic surface

  13. Laser ultrasonics for civil engineering : some applications in development for concrete non destructive testing

    International Nuclear Information System (INIS)

    Abraham, O; Cottineau, L-M; Durand, O; Popovics, J S

    2011-01-01

    Non destructive testing of civil engineering infrastructures is becoming of primary importance for their diagnosis, residual time life estimation and/or structural health monitoring. A particularity of civil engineering application is the large size of the survey zones and the expected low cost of inspection. In this context non contact ultrasonics may offer the possibility to built robots that can automatically scan large areas (or eventually be integrated in moving vehicles) to recover mechanical properties of material or to perform imagery for geometrical information recovery. In this paper we present two possible applications of in situ laser ultrasonics : one is the detection of voids in tendon duct with the impact echo method, the other is the use of surface waves to recover mechanical properties of the first centimetres of concrete structures (here after called cover concrete).

  14. Metal composite as backing for ultrasonic transducers dedicated to non-destructive measurements in hostile

    International Nuclear Information System (INIS)

    Boubenia, R; Rosenkrantz, E; P, P; Ferrandis, J-Y; Despetis, F

    2016-01-01

    Our team is specialized in ultrasonic measurements in hostile environment especially under high temperatures. There is a need for acoustic transducers capable of continuous measurement at temperatures up to 700°C. To improve the performances of acoustic sensors we focus our works on the realisation and characterisation of transducer backings able to operate under very high temperature. Commercially, they are produced by the incorporation of tungsten powder in a plastic matrix, which limits the working temperature. The realisation of ultrasonic transducers for non-destructive measures at high temperatures requires adequate materials, manufacturing and assembly processes. To produce the backings, composites were made using very ductile metals such as tin and tungsten. These composites are manufactured by uniaxial hot pressing. First, we studied the influence of temperature and pressure on the densification of tin pellets. Then, several specimens made of tin/W were made and characterised by measuring the specific weight, speed and attenuation of sound. The acoustic measures were realised by ultrasonic spectroscopy. This test-bench was designed and tested on control samples of PMMA and on standard backings (epoxy / tungsten). (paper)

  15. Ultrasound-Targeted Microbubble Destruction Improves the Migration and Homing of Mesenchymal Stem Cells after Myocardial Infarction by Upregulating SDF-1/CXCR4: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Lu Li

    2015-01-01

    Full Text Available Mesenchymal stem cell (MSC therapy shows considerable promise for the treatment of myocardial infarction (MI. However, the inefficient migration and homing of MSCs after systemic infusion have limited their therapeutic applications. Ultrasound-targeted microbubble destruction (UTMD has proven to be promising to improve the homing of MSCs to the ischemic myocardium, but the concrete mechanism remains unclear. We hypothesize that UTMD promotes MSC homing by upregulating SDF-1/CXCR4, and this study was aimed at exploring this potential mechanism. We analyzed SDF-1/CXCR4 expression after UTMD treatment in vitro and in vivo and counted the number of homing MSCs in MI areas. The in vitro results demonstrated that UTMD not only led to elevated secretion of SDF-1 but also resulted in an increased proportion of MSCs that expressed surface CXCR4. The in vivo findings show an increase in the number of homing MSCs and higher expression of SDF-1/CXCR4 in the UTMD combined with MSCs infusion group compared to other groups. In conclusion, UTMD can increase SDF-1 expression in the ischemic myocardium and upregulate the expression of surface CXCR4 on MSCs, which provides a molecular mechanism for the homing of MSCs assisted by UTMD via SDF-1/CXCR4 axis.

  16. A robust approach to optimal matched filter design in ultrasonic non-destructive evaluation (NDE)

    Science.gov (United States)

    Li, Minghui; Hayward, Gordon

    2017-02-01

    The matched filter was demonstrated to be a powerful yet efficient technique to enhance defect detection and imaging in ultrasonic non-destructive evaluation (NDE) of coarse grain materials, provided that the filter was properly designed and optimized. In the literature, in order to accurately approximate the defect echoes, the design utilized the real excitation signals, which made it time consuming and less straightforward to implement in practice. In this paper, we present a more robust and flexible approach to optimal matched filter design using the simulated excitation signals, and the control parameters are chosen and optimized based on the real scenario of array transducer, transmitter-receiver system response, and the test sample, as a result, the filter response is optimized and depends on the material characteristics. Experiments on industrial samples are conducted and the results confirm the great benefits of the method.

  17. An ultrasonic methodology to non-destructively estimate the grain orientation in an anisotropic weld

    Directory of Open Access Journals (Sweden)

    Wirdelius Håkan

    2014-06-01

    Full Text Available The initial step towards a non-destructive technique that estimates grain orientation in an anisotropic weld is presented in this paper. The purpose is to aid future forward simulations of ultrasonic NDT of this kind of weld to achieve a better result. A forward model that consists of a weld model, a transmitter model, a receiver model and a 2D ray tracing algorithm is introduced. An inversion based on a multi-objective genetic algorithm is also presented. Experiments are conducted for both P and SV waves in order to collect enough data used in the inversion. Calculation is conducted to fulfil the estimation with both the synthetic data and the experimental data. Concluding remarks are presented at the end of the paper.

  18. Ultrasonic non-destructive testing of pieces of complex geometry with a flexible phased array transducer

    Science.gov (United States)

    Chatillon; Cattiaux; Serre; Roy

    2000-03-01

    Ultrasonic non-destructive testing of components of complex geometry in the nuclear industry faces several difficulties: sensitivity variations due to unmatched contact, inaccurate localization of defects due to variations of transducer orientation, and uncovered area of the component. To improve the performances of such testing and defect characterization, we propose a new concept of ultrasonic contact phased array transducer. The phased array transducer has a flexible radiating surface able to fit the actual surface of the piece to optimize the contact and thus the sensitivity of the test. To control the transmitted field, and therefore to improve the defect characterization, a delay law optimizing algorithm is developed. To assess the capability of such a transducer, the Champ-Sons model, developed at the French Atomic Energy Commission for predicting field radiated by arbitrary transducers into pieces, has to be extended to sources directly in contact with pieces of complex geometry. The good behavior of this new type of probe predicted by computations is experimentally validated with a jointed transducer positioned on pieces of various profiles.

  19. Functional and pathological improvements of the hearts in diabetes model by the combined therapy of bFGF-loaded nanoparticles with ultrasound-targeted microbubble destruction.

    Science.gov (United States)

    Zhao, Ying-Zheng; Tian, Xin-Qiao; Zhang, Ming; Cai, Lu; Ru, Ao; Shen, Xiao-Tong; Jiang, Xi; Jin, Rong-Rong; Zheng, Lei; Hawkins, Kyle; Charkrabarti, Subrata; Li, Xiao-Kun; Lin, Qian; Yu, Wen-Ze; Ge, Shuping; Lu, Cui-Tao; Wong, Ho Lun

    2014-07-28

    Diabetic cardiomyopathy (DCM) is the leading cause of morbidity and mortality among the diabetic patients and currently there is no effective means to reverse its pathological progress. Basic fibroblast growth factor (bFGF) has shown promise as a molecular therapy for DCM, but its delivery is inefficient and non-specific. In the present study, a therapy combining nanoparticle (NP) carrier and ultrasound-targeted microbubble destruction (UTMD) was reported the first time for bFGF delivery to the heart of diabetic rats. bFGF-loaded NP (bFGF-NP) were prepared with Poloxamer 188-grafted heparin copolymer using water-in-water technique, and the morphology, encapsulation efficiency, and bioactivity of bFGF-NP were studied. The cellular uptake and cytotoxicity of bFGF-NP were evaluated with primary cultures of the left ventricular (LV) cardiomyocytes in vitro. Therapeutic effects of bFGF-NP/UTMD on the heart of DCM rats were studied by measuring LV systolic and diastolic functions, hemodynamic characteristics and indicators of cardiac remodeling including myocardial collagen volume fraction and capillary density. Results demonstrated that bFGF-NP showed good round morphology, efficient bFGF encapsulation and stable bioactivity of bFGF in vitro. bFGF-NP/UTMD combined treatment significantly enhanced the efficiency of bFGF cellular uptake (Pfunctions and tissue morphology in the DCM rats were observed in bFGF-NP/UTMD group. These were not achievable using free bFGF, bFGF-NP or UTMD treatment alone. Our results show that combining a non-viral vector with UTMD technique is an effective strategy to deliver bFGF to the heart, and the resulting growth factor therapy has demonstrated potential to reverse the progress of DCM by restoring the cardiac functions and even the structure of damaged cardiac tissues. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Enhanced delivery of PEAL nanoparticles with ultrasound targeted microbubble destruction mediated siRNA transfection in human MCF-7/S and MCF-7/ADR cells in vitro

    Directory of Open Access Journals (Sweden)

    Teng Y

    2015-08-01

    Full Text Available Yanwei Teng,1,2,* Min Bai,3,* Ying Sun,2 Qi Wang,1,2 Fan Li,3 Jinfang Xing,3 Lianfang Du,3 Tao Gong,1 Yourong Duan2 1Key Laboratory of Drug Targeting and Novel Drug Delivery Systems, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, People’s Republic of China; 2State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, People’s Republic of China; 3Department of Ultrasound, Shanghai First People’s Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: The gene knockdown activity of small interfering RNA (siRNA has led to their use as potential therapeutics for a variety of diseases. However, successful gene therapy requires safe and efficient delivery systems. In this study, we choose mPEG-PLGA-PLL nanoparticles (PEAL NPs with ultrasound targeted microbubble destruction (UTMD to efficiently deliver siRNA into cells. An emulsification-solvent evaporation method was used to prepare siRNA-loaded PEAL NPs. The NPs possessed an average size of 132.6±10.3 nm (n=5, with a uniform spherical shape, and had an encapsulation efficiency (EE of more than 98%. As demonstrated by MTT assay, neither PEAL NPs nor siRNA-loaded PEAL NPs showed cytotoxicity even at high concentrations. The results of cellular uptake showed, with the assistance of UTMD, the siRNA-loaded PEAL NPs can be effectively internalized and can subsequently release siRNA in cells. Taken together, PEAL NPs with UTMD may be highly promising for siRNA delivery, making it possible to fully exploit the potential of siRNA-based therapeutics. Keywords: gene delivery, mPEG-PLGA-PLL, UTMD, emulsification-solvent evaporation method, orthogonal design

  1. Non-destructive Inspection of Top-Down Construction Joints of Column in SRC Structure using Ultrasonic Method

    International Nuclear Information System (INIS)

    Park, Seok Kyun; Baek, Un Chan; Lee, Han Bum; Kim, Myoung Mo

    2000-01-01

    The joint treatment of concrete is one of the technical problems in top down construction method. Joints created with the top down construction result in serious weakness from the aspects of both structural and water-barrier function. Ultrasonic method was used for the inspection of top down construction joints of a various column in SRC structure in this study. The advantages and limitations of this method for non-destructive inspection in top down construction joints are investigated. As a result, it has been verified that the semi-direct measurement method is more effective than the other methods for detecting the voids of construction joints using ultrasonic method

  2. Non destructive characterization of cracks in concrete by ultrasonic auscultation of civil engineering structures

    International Nuclear Information System (INIS)

    Quiviger, A.; Payan, C.; Chaix, J.F.; Zardan, J.P.; Garnier, V.; Salin, J.

    2011-01-01

    Concrete Non Destructive Characterisation is one of the important issues to evaluate the life duration in the present and future civil engineering structures. The damaging modes of the structures often imply the phases of the appearance and after growth of the cracks. We have to detect, identify and characterize them. The characterization result must lead to a diagnosis of the criticality of a crack regarding to the integrity of the structure and its ability to fulfill its function. The Non Destructive Evaluation techniques are numerous but the ultrasonic ones are able to give an answer to both the characterization and the follow-up of the defect on site. Yet if this method is potentially relevant to detect and identify the cracks in the concrete, we have today a certain amount of locks to remove in order to offer robust and reproducible industrial solutions. These locks range from research points like the description of the real propagation of linear or non linear ultrasonic waves in a heterogeneous material, to more industrial concepts such as the development of devices designed to be applied in the concrete control. For this purpose, we present our latest works on this topic. We develop an overview of the problem: first, to extract the most important theoretical solutions to analyse an unstopping and closed crack in concrete with an only one face access. Then we suggest a methodology to apply one of these solutions on site. A first step of this work after having chosen a solution is to check the ability of the technique to detect a crack, and its sensitivity to the length, depth and opening of the crack. We have developed an experimental plan based on theoretical concept to compare the linear and non linear survey on a set of specimens composed of concrete beams cracked to different depths. We describe the devices and give the latest results. The non linear technique is able to extract information on the size of the cracks. It is an important step to progress in

  3. Non destructive characterization of cracks in concrete by ultrasonic auscultation of civil engineering structures

    Energy Technology Data Exchange (ETDEWEB)

    Quiviger, A.; Payan, C.; Chaix, J.F.; Zardan, J.P.; Garnier, V. [EDF, LCND (France); Salin, J. [EDF Paris (France)

    2011-07-01

    Concrete Non Destructive Characterisation is one of the important issues to evaluate the life duration in the present and future civil engineering structures. The damaging modes of the structures often imply the phases of the appearance and after growth of the cracks. We have to detect, identify and characterize them. The characterization result must lead to a diagnosis of the criticality of a crack regarding to the integrity of the structure and its ability to fulfill its function. The Non Destructive Evaluation techniques are numerous but the ultrasonic ones are able to give an answer to both the characterization and the follow-up of the defect on site. Yet if this method is potentially relevant to detect and identify the cracks in the concrete, we have today a certain amount of locks to remove in order to offer robust and reproducible industrial solutions. These locks range from research points like the description of the real propagation of linear or non linear ultrasonic waves in a heterogeneous material, to more industrial concepts such as the development of devices designed to be applied in the concrete control. For this purpose, we present our latest works on this topic. We develop an overview of the problem: first, to extract the most important theoretical solutions to analyse an unstopping and closed crack in concrete with an only one face access. Then we suggest a methodology to apply one of these solutions on site. A first step of this work after having chosen a solution is to check the ability of the technique to detect a crack, and its sensitivity to the length, depth and opening of the crack. We have developed an experimental plan based on theoretical concept to compare the linear and non linear survey on a set of specimens composed of concrete beams cracked to different depths. We describe the devices and give the latest results. The non linear technique is able to extract information on the size of the cracks. It is an important step to progress in

  4. Resolution enhancement for ultrasonic echographic technique in non destructive testing with an adaptive deconvolution method

    International Nuclear Information System (INIS)

    Vivet, L.

    1989-01-01

    The ultrasonic echographic technique has specific advantages which makes it essential in a lot of Non Destructive Testing (NDT) investigations. However, the high acoustic power necessary to propagate through highly attenuating media can only be transmitted by resonant transducers, which induces severe limitations of the resolution on the received echograms. This resolution may be improved with deconvolution methods. But one-dimensional deconvolution methods come up against problems in non destructive testing when the investigated medium is highly anisotropic and inhomogeneous (i.e. austenitic steel). Numerous deconvolution techniques are well documented in the NDT literature. But they often come from other application fields (biomedical engineering, geophysics) and we show they do not apply well to specific NDT problems: frequency-dependent attenuation and non-minimum phase of the emitted wavelet. We therefore introduce a new time-domain approach which takes into account the wavelet features. Our method solves the deconvolution problem as an estimation one and is performed in two steps: (i) A phase correction step which takes into account the phase of the wavelet and estimates a phase-corrected echogram. The phase of the wavelet is only due to the transducer and is assumed time-invariant during the propagation. (ii) A band equalization step which restores the spectral content of the ideal reflectivity. The two steps of the method are performed using fast Kalman filters which allow a significant reduction of the computational effort. Synthetic and actual results are given to prove that this is a good approach for resolution improvement in attenuating media [fr

  5. Design and fabrication of liner-arroy ultrasonic transducer using KLM and FEM simulation for non-destructive testing

    International Nuclear Information System (INIS)

    Park, Chan Yuk; Sung, Jin Ho; Jeong, Jong Seob

    2015-01-01

    In this paper, a linear-array transducer capable of overcoming the faults of a single element and phased array transducers with convex shape for non-destructive ultrasonic testing was designed and fabricated. A 5.5 MHz linear-array transducer was designed using the PiezoCAD program based on the KLM analysis and the PZFlex program based on the FEM analysis. A 2-2 composite structure was employed to achieve broad-band characteristics. A 128 element linear-array transducer was fabricated and its performance was compared with the simulation results. The center frequency of the fabricated transducer was 5.5 Mhzand the -6 dB frequency bandwidth was 70 %. Thus, we expect that the designed transducer can provide an effective inner image of the test material during non-destructive ultrasonic testing.

  6. Design and fabrication of liner-arroy ultrasonic transducer using KLM and FEM simulation for non-destructive testing

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chan Yuk; Sung, Jin Ho; Jeong, Jong Seob [Dept. of Medical Biotechnology, Dongguk University Biomedi Campus, Goyang (Korea, Republic of)

    2015-04-15

    In this paper, a linear-array transducer capable of overcoming the faults of a single element and phased array transducers with convex shape for non-destructive ultrasonic testing was designed and fabricated. A 5.5 MHz linear-array transducer was designed using the PiezoCAD program based on the KLM analysis and the PZFlex program based on the FEM analysis. A 2-2 composite structure was employed to achieve broad-band characteristics. A 128 element linear-array transducer was fabricated and its performance was compared with the simulation results. The center frequency of the fabricated transducer was 5.5 Mhzand the -6 dB frequency bandwidth was 70 %. Thus, we expect that the designed transducer can provide an effective inner image of the test material during non-destructive ultrasonic testing.

  7. Non-destructive Inspection of Multi-layered Composite Using Ultrasonic Signal Processing

    International Nuclear Information System (INIS)

    Ng, S C; Ismail, N; Ali, Aidy; Sahari, Barkawi; Yusof, J M; Chu, B W

    2011-01-01

    Composites exhibit higher strength and stiffness, better design practice and greater corrosion resistance compare to metal material. However, composites are susceptible to impact damage and the typical damage behaviour in the laminated composites is fibre-breakage and delamination. Detection of failure in laminated composites is complicated compared with ordinary non-destructive testing for metal materials as they are sensitive to echoes drown in noise due to the properties of the constituent materials and the multi-layered structure of the composites. In the current study, the detection of failure in multi-layered composite materials is investigated. To obtain a high probability of defect detection in composite materials, signal processing algorithms were used to resolve echoes associated with defects in glass fibre-reinforced plastics (GRP) detected by using ultrasonic testing. Pulse-echo method with single transducer was used to transmit and receive ultrasound. The obtained signals were processed to reduce noise and to extract suitable features. Results were validated on GRP with and without defects in order to demonstrate the feasibility of the method on defect detection in composites.

  8. Ultrasonic non-destructive testing on CFC monoblock divertor mock-up

    International Nuclear Information System (INIS)

    Ezato, K.; Taniguchi, M.; Sato, K.; Araki, M.; Akiba, M.

    2001-01-01

    Non-destructive ultrasonic testing has been applied for the characterization of joints by means of a polymer transducer. One of the advantages of the polymer transducer is flexibility in its shape and the possibility to install multiple transducers in one probe, which can reduce the time for inspection. As a first step, the size effect of the transducer on the resolution and sensitivity was examined to detect the joint flaw. Transducers with circumferential angles of 5 , 10 and 30 were tested. For this test a small divertor element with a driller hole was prepared, which simulates a joint defect. The transducers with angles of 30 could not characterize the size of the artificial joint flaw. On the contrary, the size of the artificial defect was successfully detected with an accuracy of 90% by means of the transducers with angles of 5 and 10 . From the viewpoint of the sensitivity of the detection of the joint flaw, the transducer with the angle of 10 is appropriate because it could detect the largest intensity of the reflected signal caused by the same artificial defect of the joint interface. (orig.)

  9. Community survey on reference blocks and transducers for non-destructive ultrasonic testing

    International Nuclear Information System (INIS)

    Vinche, C.; Borloo, E.; Jehenson, P.

    1978-01-01

    In the frame of the European programmes 'Standards and Reference Substances' and 'Reference Materials and Methods' (BCR) the Commission of the European Communities, in conjunction with National experts launched in 1975 an inquiry on reference blocks and transducers for non-destructive ultrasonic testing. This inquiry which is complementary to a general survey made in 1971-1972 by the Commission on Reference Materials (Ref. EUR Report 1973. EUR 4886. d,f,i,n,e) was felt necessary and prepared by a specialists group from the Community Countries and the Joint Research Centre (JRC), Ispra Establishment (the list of these specialists is indicated on p. 2 of the questionnaire). The results of this survey, collated by the JRC Ispra Members have been discussed by the group of specialists and form the subject of this report. On bases of mailing lists submitted by national specialists, 215 organizations have been contacted; the fields of activity of these organizations are mainly: metallurgy, machine parts, technical assistance, aeronautics, power stations and research, 73 organizations have replied to the questionnaire. Most answers were obained from organizations dealing with metallurgy, machine parts manufacturers and technical consultants. The annexes supply a detailed analysis of the results given, on a national basis

  10. Quantification of the energy required for the destruction of Balanus Amphitrite larva by ultrasonic treatment

    Digital Repository Service at National Institute of Oceanography (India)

    Seth, N.; Chakravarty, P.; Khandeparker, L.; Anil, A.C.; Pandit, A.B.

    result of ultrasonic irradiation include free radicals like the hydroxyl radicals. One of the recent studies by Gavand et al. (2007) reported that a combination of sonication and advanced chemical oxidants could be more promising method to eradicate...

  11. Numeric ultrasonic image processing method: application to non-destructive testing of stainless austenitic steel welds

    International Nuclear Information System (INIS)

    Corneloup, G.

    1988-09-01

    A bibliographic research on the means used to improve the ultrasonic inspection of heterogeneous materials such as stainless austenitic steel welds has shown, taking into account the first analysis, a signal assembly in the form of an image (space, time) which carries an original solution to fault detection in highly noisy environments. A numeric grey-level ultrasonic image processing detection method is proposed based on the research of a certain determinism, in the way which the ultrasonic image evolves in space and time in the presence of a defect: the first criterion studies the horizontal stability of the gradients in the image and the second takes into account the time-transient nature of the defect echo. A very important rise in the signal-to-noise ratio obtained in welding inspections evidencing defects (real and artificial) is shown with the help of a computerized ultrasonic image processing/management system, developed for this application [fr

  12. Fatigue crack growth studies on a tee junction using ultrasonic non-destructive methods

    International Nuclear Information System (INIS)

    Subramanian, C.V.; Thavasimuthu, M.; Ramesh, A.S.; Jayakumar, T.; Kalyanasundaram, P.; Baldev Raj

    1996-01-01

    Fatigue cracks need to be detected and sized to maintain structural integrity. The significance of cracks detected in service must also be assessed. This paper describes the on-line ultrasonic testing carried out on a Tee joint subjected to fatigue loading. The initiation and growth of the cracks were monitored for every 5,000 cycles up to 40,000 cycles. The study demonstrated the use of ultrasonic testing for fatigue crack growth detection and sizing. (author)

  13. Babcock experience of automated ultrasonic non-destructive testing of PWR pressure vessels during manufacture

    International Nuclear Information System (INIS)

    Dikstra, B.J.; Farley, J.M.; Scruton, G.

    1990-01-01

    Major developments in ultrasonic techniques, equipment and systems for automated inspection have lead, over a period of about ten years, to the regular application of sophisticated computer-controlled systems during the manufacture of nuclear reactor pressure vessels. Ten years ago the use of procedures defined in a code such as ASME XI might have been considered sufficient, but it is now necessary, as was demonstrated by the results of the UKAEA defect detection trials and the PISC II trials, to apply more comprehensive arrays of probes and higher test sensitivities. The ultrasonic techniques selected are demonstrated to be adequate by modelling or test-block exercises, the automated systems applied are subject to stringent quality assurance testing, and very rigorous inspection procedures are used in conjunction with a high degree of automation to ensure reproducibility of inspection quality. The state-of-the-art in automated ultrasonic testing of pressure vessels by Babcock is described. Current developments by the company, including automated flaw recognition, integrated modelling of inspection capability, and the use of electronically scanned variable-angle probes are reviewed. Examples quoted include the automated ultrasonic inspections of the Sizewell B pressurized water reactor vessel. (author)

  14. Evaluation of Creep-Fatigue Damage in 304 Stainless Steel using Ultrasonic Non-Destructive Test

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Sik [Safetech Co. Ltd., Kimhae (Korea, Republic of); Oh, Yong Jun [Hanbat National Univ., Daejon (Korea, Republic of); Nam, Soo Woo [KISTI ReSEAT Program, Seoul (Korea, Republic of)

    2011-12-15

    It is well known that grain boundary cavitation is the main failure mechanism in austenitic stainless steel under tensile hold creep-fatigue interaction conditions. The cavities are nucleated at the grain boundary during cyclic loading and grow to become grain boundary cracks. The attenuation of ultrasound depends on scattering and absorption in polycrystalline materials. Scattering occurs when a propagation wave encounters microstructural discontinuities, such as internal voids or cavities. Since the density of the creepfatigue cavities increases with the fatigue cycles, the attenuation of ultrasound will also be increased with the fatigue cycles and this attenuation can be detected nondestructively. In this study, it is found that individual grain boundary cavities are formed and grow up to about 100 cycles and then, these cavities coalesce to become cracks. The measured ultrasonic attenuation increased with the cycles up to cycle 100, where it reached a maximum value and then decreased with further cycles. These experimental measurements strongly indicate that the open pores of cavities contribute to the attenuation of ultrasonic waves. However, when the cavities develop, at the grain boundary cracks whose crack surfaces are in contact with each other, there is no longer any open space and the ultrasonic wave may propagate across the cracks. Therefore, the attenuation of ultrasonic waves will be decreased. This phenomenon of maximum attenuation is very important to judge the stage of grain boundary crack development, which is the indication of the dangerous stage of the structures.

  15. Microwave Detection of Laser Ultrasonic for Non-Destructive Testing, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, we describe a program to develop a high-performance, cost-effective and robust microwave receiver prototype for multi-purpose Non-Destructive...

  16. Study of different ultrasonic focusing methods applied to non destructive testing

    International Nuclear Information System (INIS)

    El Amrani, M.

    1995-01-01

    The work presented in this thesis concerns the study of different ultrasonic focusing techniques applied to Nondestructive Testing (mechanical focusing and electronic focusing) and compares their capabilities. We have developed a model to predict the ultrasonic field radiated into a solid by water-coupled transducers. The model is based upon the Rayleigh integral formulation, modified to take account the refraction at the liquid-solid interface. The model has been validated by numerous experiments in various configurations. Running this model and the associated software, we have developed new methods to optimize focused transducers and studied the characteristics of the beam generated by transducers using various focusing techniques. (author). 120 refs., 95 figs., 4 appends

  17. Non-Destructive Inspection of Impact Damage in Composite Aircraft Panels by Ultrasonic Guided Waves and Statistical Processing

    Directory of Open Access Journals (Sweden)

    Margherita Capriotti

    2017-06-01

    Full Text Available This paper discusses a non-destructive evaluation (NDE technique for the detection of damage in composite aircraft structures following high energy wide area blunt impact (HEWABI from ground service equipment (GSE, such as heavy cargo loaders and other heavy equipment. The test structures typically include skin, co-cured stringers, and C-frames that are bolt-connected onto the skin with shear ties. The inspection exploits the waveguide geometry of these structures by utilizing ultrasonic guided waves and a line scan approach. Both a contact prototype and a non-contact prototype were developed and tested on realistic test panels subjected to impact in the laboratory. The results are presented in terms of receiver operating characteristic curves that show excellent probability of detection with low false alarm rates for defects located in the panel skin and stringers.

  18. Non-destructive evaluation of the cladding thickness in LEU fuel plates by accurate ultrasonic scanning technique

    Energy Technology Data Exchange (ETDEWEB)

    Borring, J.; Gundtoft, H.E.; Borum, K.K.; Toft, P. [Riso National Lab. (Denmark)

    1997-08-01

    In an effort to improve their ultrasonic scanning technique for accurate determination of the cladding thickness in LEU fuel plates, new equipment and modifications to the existing hardware and software have been tested and evaluated. The authors are now able to measure an aluminium thickness down to 0.25 mm instead of the previous 0.35 mm. Furthermore, they have shown how the measuring sensitivity can be improved from 0.03 mm to 0.01 mm. It has now become possible to check their standard fuel plates for DR3 against the minimum cladding thickness requirements non-destructively. Such measurements open the possibility for the acceptance of a thinner nominal cladding than normally used today.

  19. Non-Destructive Inspection of Impact Damage in Composite Aircraft Panels by Ultrasonic Guided Waves and Statistical Processing.

    Science.gov (United States)

    Capriotti, Margherita; Kim, Hyungsuk E; Scalea, Francesco Lanza di; Kim, Hyonny

    2017-06-04

    This paper discusses a non-destructive evaluation (NDE) technique for the detection of damage in composite aircraft structures following high energy wide area blunt impact (HEWABI) from ground service equipment (GSE), such as heavy cargo loaders and other heavy equipment. The test structures typically include skin, co-cured stringers, and C-frames that are bolt-connected onto the skin with shear ties. The inspection exploits the waveguide geometry of these structures by utilizing ultrasonic guided waves and a line scan approach. Both a contact prototype and a non-contact prototype were developed and tested on realistic test panels subjected to impact in the laboratory. The results are presented in terms of receiver operating characteristic curves that show excellent probability of detection with low false alarm rates for defects located in the panel skin and stringers.

  20. Non-destructive evaluation of the cladding thickness in LEU fuel plates by accurate ultrasonic scanning technique

    International Nuclear Information System (INIS)

    Borring, J.; Gundtoft, H.E.; Borum, K.K.; Toft, P.

    1997-01-01

    In an effort to improve their ultrasonic scanning technique for accurate determination of the cladding thickness in LEU fuel plates, new equipment and modifications to the existing hardware and software have been tested and evaluated. The authors are now able to measure an aluminium thickness down to 0.25 mm instead of the previous 0.35 mm. Furthermore, they have shown how the measuring sensitivity can be improved from 0.03 mm to 0.01 mm. It has now become possible to check their standard fuel plates for DR3 against the minimum cladding thickness requirements non-destructively. Such measurements open the possibility for the acceptance of a thinner nominal cladding than normally used today

  1. Identification of the Quality Spot Welding used Non Destructive Test-Ultrasonic Testing: (Effect of Welding Time)

    Science.gov (United States)

    Sifa, A.; Endramawan, T.; Badruzzaman

    2017-03-01

    Resistance Spot Welding (RSW) is frequently used as one way of welding is used in the manufacturing process, especially in the automotive industry [4][5][6][7]. Several parameters influence the process of welding points. To determine the quality of a welding job needs to be tested, either by damaging or testing without damage, in this study conducted experimental testing the quality of welding or identify quality of the nugget by using Non-Destructive Test (NDT) -Ultrasonic Testing (UT), in which the identification of the quality of the welding is done with parameter thickness of worksheet after welding using NDT-UT with use same material worksheet and have more thickness of worksheet, the thickness of the worksheet single plate 1mm, with the capability of propagation Ultrasonic Testing (UT) standard limited> 3 mm [1], welding process parameters such as the time difference between 1-10s and the welding current of 8 KV, visually Heat Affected Zone ( HAZ ) have different results due to the length of time of welding. UT uses a probe that is used with a frequency of 4 MHz, diameter 10 mm, range 100 and the couplant used is oil. Identification techniques using drop 6dB, with sound velocity 2267 m / s of Fe, with the result that the effect of the Welding time affect the size of the HAZ, identification with the lowest time 1s show results capable identified joined through NDT - UT.

  2. Laser ultrasonic receivers based on photorefractive materials in non-destructive testing

    International Nuclear Information System (INIS)

    Zamiri Hosseinzadeh, S.

    2014-01-01

    The field of laser ultrasonics is one of the most interesting topics in which laser light is used for the generation and the detection of ultrasound waves in materials. This contactless method is extremely useful for materials inspection being nondestructive and contactless, especially for hazardous environments. In this method a pulsed laser with a short pulse length of e.g. nano- or even picoseconds is focused on the surface of a specimen and then ultrasonic waves, nanometer vibrations, such as surface and bulk waves are generated and propagate in all directions on to the material. For contactless detection of ultrasonic waves several interferometers such as confocal Fabry-Perot, Michelson, and long path difference interferometers have been applied. Each of them has its individual advantages and disadvantages concerning, e.g., frequency responses and sensitivity. However, most of these interferometers work best on mirror-like surfaces and exhibit reduced sensitivity on rough surfaces. Also these kinds of interferometer are sensible to external noise as air fluctuations, sample vibrations or thermal deformations, thus requiring relatively complex stabilization techniques. This hinders their applicability in industrial applications with harsh environmental conditions. As an alternative to the before mentioned techniques interferometers based on photorefractive materials (PR) have been established. A typical two wave mixing interferometer (TWMI) configuration enables broadband ultrasonic measurements on rough surfaces. These types of interferometers have a good sensitivity up to 3e-7 nm(W/Hz) 1/2 spatially for samples with a high rough surface unlike the Michelson interferometer. By using ferroelectric photorefractive crystals such as LiNbO:Fe+2, sensitivity even is enhanced to 4e-8 nm(W/Hz) 1/2 but response time in these crystals is slower. In this work, contactless interferometer set ups based on photorefractive materials such as BSO (Bismuth Silicon Oxide: Bi 12

  3. Non-destructive ultrasonic techniques for classifying and reconstructing defects; ALOK, phased arrays, holography-SAFT

    International Nuclear Information System (INIS)

    Hoeller, P.; Schmitz, V.; Mueller, W.; Gebhardt, W.; Barbian, O.A.

    1983-01-01

    The only way to achieve ultrasonic testing methods capable of reconstructing defects or inhomogeneities is to measure those data that are related to the geometry of the reflector. These are phase and time-of-flight as a function of the locus of incidence. For this purpose several synthetic aperture methods have been developed in recent years by our institute: ALOK and phased arrays as searching and analysing systems, especially for in-service inspection of nuclear power plants; and holography and SAFT as analysing systems. Their ability to detect, localize, classify and reconstruct defects is discussed. (author)

  4. A Gaussian beam method for ultrasonic non-destructive evaluation modeling

    Science.gov (United States)

    Jacquet, O.; Leymarie, N.; Cassereau, D.

    2018-05-01

    The propagation of high-frequency ultrasonic body waves can be efficiently estimated with a semi-analytic Dynamic Ray Tracing approach using paraxial approximation. Although this asymptotic field estimation avoids the computational cost of numerical methods, it may encounter several limitations in reproducing identified highly interferential features. Nevertheless, some can be managed by allowing paraxial quantities to be complex-valued. This gives rise to localized solutions, known as paraxial Gaussian beams. Whereas their propagation and transmission/reflection laws are well-defined, the fact remains that the adopted complexification introduces additional initial conditions. While their choice is usually performed according to strategies specifically tailored to limited applications, a Gabor frame method has been implemented to indiscriminately initialize a reasonable number of paraxial Gaussian beams. Since this method can be applied for an usefully wide range of ultrasonic transducers, the typical case of the time-harmonic piston radiator is investigated. Compared to the commonly used Multi-Gaussian Beam model [1], a better agreement is obtained throughout the radiated field between the results of numerical integration (or analytical on-axis solution) and the resulting Gaussian beam superposition. Sparsity of the proposed solution is also discussed.

  5. Synthesis of strontium substituted barium titanate nanoparticles by mechanical alloying and high power ultrasonication destruction

    Energy Technology Data Exchange (ETDEWEB)

    Yustanti, Erlina, E-mail: erlina.yustanti@ui.ac.id [Graduate Program of Material Science, Faculty of Mathematics and Natural Sciences University of Indonesia Jl. Salemba Raya No. 04 Jakarta 10430 (Indonesia); Department of Metallurgy, Faculty of Engineering University of Sultan AgengTirtayasa Jl. Jenderal Sudirman KM 03 Cilegon-Banten 65134 (Indonesia); Hafizah, Mas Ayu Elita, E-mail: kemasayu@yahoo.com; Manaf, Azwar, E-mail: azwar@ui.ac.id [Graduate Program of Material Science, Faculty of Mathematics and Natural Sciences University of Indonesia Jl. Salemba Raya No. 04 Jakarta 10430 (Indonesia)

    2016-04-19

    This paper reports the particle and crystallite size characterizations of mechanically alloyed Ba{sub (1-x)}Sr{sub x}TiO{sub 3} (BST) with x = 0.3 and 0.7 prepared with the assistance of a high-power sonicator. Analytical grade BaCO{sub 3}, TiO{sub 2} and SrCO{sub 3} precursors with a purity of greater than 99 wt.% were mixed and milled using a planetary ball mill to a powder weight ratio of 10:1. Powders obtained after 20 hours of milling time were then sintered at 1200°C for 4 hours to form crystalline powders.These powders were further treated ultrasonically under a fixed 6.7 gr/l particle concentration in demineralized water for 1, 3, 5, 7 hours and a fixed ultrasonic irradiation time of 1 hour to the dispersion of 6.7; 20; 33.3 gr/l concentrations. As to the results of crystallite size characterization, it is demonstrated that the mean crystallite size of BST with x = 0.3 and 0.7 undergo a slight change after the first 1 hour irradiation time and then remain almost unchanged. This was in contrary to the particle size in which the mean particle size of BST with x = 0.3 increased from 765 nm to 1405 nm after 7 hours irradiation time, while that of x = 0.7 increased from 505 nm to 1298 nm after 3 hours and then reduced back to the initial size after 7 hours ultra sonication time. The increase in particle size was due to large of cohesive forces among fine particles. It is also demonstrated that the concentration of particles in a dispersion with anionic surfactant do not effective to reduce the particle sizes ultrasonically. Nanoparticles with the mean size respectively 40 and 10 times larger than their respective crystallite size were successfully obtained respectively in x = 0.3 and x = 0.7.

  6. Synthesis of strontium substituted barium titanate nanoparticles by mechanical alloying and high power ultrasonication destruction

    International Nuclear Information System (INIS)

    Yustanti, Erlina; Hafizah, Mas Ayu Elita; Manaf, Azwar

    2016-01-01

    This paper reports the particle and crystallite size characterizations of mechanically alloyed Ba (1-x) Sr x TiO 3 (BST) with x = 0.3 and 0.7 prepared with the assistance of a high-power sonicator. Analytical grade BaCO 3 , TiO 2 and SrCO 3 precursors with a purity of greater than 99 wt.% were mixed and milled using a planetary ball mill to a powder weight ratio of 10:1. Powders obtained after 20 hours of milling time were then sintered at 1200°C for 4 hours to form crystalline powders.These powders were further treated ultrasonically under a fixed 6.7 gr/l particle concentration in demineralized water for 1, 3, 5, 7 hours and a fixed ultrasonic irradiation time of 1 hour to the dispersion of 6.7; 20; 33.3 gr/l concentrations. As to the results of crystallite size characterization, it is demonstrated that the mean crystallite size of BST with x = 0.3 and 0.7 undergo a slight change after the first 1 hour irradiation time and then remain almost unchanged. This was in contrary to the particle size in which the mean particle size of BST with x = 0.3 increased from 765 nm to 1405 nm after 7 hours irradiation time, while that of x = 0.7 increased from 505 nm to 1298 nm after 3 hours and then reduced back to the initial size after 7 hours ultra sonication time. The increase in particle size was due to large of cohesive forces among fine particles. It is also demonstrated that the concentration of particles in a dispersion with anionic surfactant do not effective to reduce the particle sizes ultrasonically. Nanoparticles with the mean size respectively 40 and 10 times larger than their respective crystallite size were successfully obtained respectively in x = 0.3 and x = 0.7.

  7. Ultrasonic signature

    International Nuclear Information System (INIS)

    Borloo, E.; Crutzen, S.

    1974-12-01

    The unique and tamperproof identification technique developed at Ispra is based on ultrasonic Non-Destructive-Techniques. Reading fingerprints with ultrasonic requires high reproducibility of standard apparatus and transducers. The present report gives an exhaustive description of the ultrasonic technique developed for identification purposes. Different applications of the method are described

  8. Ultrasonic Analysis of Peptide- and Antibody-Targeted Microbubble Contrast Agents for Molecular Imaging of αvβ3-Expressing Cells

    Directory of Open Access Journals (Sweden)

    Paul A. Dayton

    2004-04-01

    Full Text Available The goal of targeted ultrasound contrast agents is to significantly and selectively enhance the detection of a targeted vascular site. In this manuscript, three distinct contrast agents targeted to the αvβ3 integrin are examined. The αvβ3 integrin has been shown to be highly expressed on metastatic tumors and endothelial cells during neovascularization, and its expression has been shown to correlate with tumor grade. Specific adhesion of these contrast agents to αvβ3-expressing cell monolayers is demonstrated in vitro, and compared with that of nontargeted agents. Acoustic studies illustrate a backscatter amplitude increase from monolayers exposed to the targeted contrast agents of up to 13-fold (22 dB relative to enhancement due to control bubbles. A linear dependence between the echo amplitude and bubble concentration was observed for bound agents. The decorrelation of the echo from adherent targeted agents is observed over successive pulses as a function of acoustic pressure and bubble density. Frequency–domain analysis demonstrates that adherent targeted bubbles exhibit high-amplitude narrowband echo components, in contrast to the primarily wideband response from free microbubbles. Results suggest that adherent targeted contrast agents are differentiable from free-floating microbubbles, that targeted contrast agents provide higher sensitivity in the detection of angiogenesis, and that conventional ultrasound imaging techniques such as signal subtraction or decorrelation detection can be used to detect integrin-expressing vasculature with sufficient signal-to-noise.

  9. Resolution improvement of ultrasonic echography methods in non destructive testing by adaptative deconvolution

    International Nuclear Information System (INIS)

    Vivet, L.

    1989-01-01

    The ultrasonic echography has a lot of advantages which make it attractive for nondestructive testing. But the important acoustic energy useful to go through very attenuating materials can be got only with resonant translators, that is a limit for the resolution on measured echograms. This resolution can be improved by deconvolution. But this method is a problem for austenitic steel. Here is developed a method of time deconvolution which allows to take in account the characteristics of the wave. A first step of phase correction and a second step of spectral equalization which gives back the spectral contents of ideal reflectivity. The two steps use fast Kalman filters which reduce the cost of the method

  10. Beginning of fish defrosting by using non-destructive ultrasonic technique

    International Nuclear Information System (INIS)

    Malainine, M; Faiz, B; Izbaim, D; Aboudaoud, I; Moudden, A; Maze, G

    2012-01-01

    During the experiments carried out on the monitoring and the study of fish defrosting by an ultrasonic technique, we have difficulties in detecting the beginning of the thawing which is an important criterion of fish quality control. To address this problem, we use the Singular Value Decomposition method (SVD) which is a mathematical tool that permits to separate the high and low energies of an histogram. The image representing low energy signals indicates the start of the thawing by showing an echo that was hidden in the original image for cod fish. Using transducers for central frequencies above 500 kHz the observed results are not very good. Therefore, this method is suitable for fish which fat content is medium or low.

  11. Universality of Nonclassical Nonlinearity Applications to Non-Destructive Evaluations and Ultrasonic

    CERN Document Server

    Delsanto, Pier Paolo

    2006-01-01

    This book comes as a result of the research work developed in the framework of two international projects: the European Science Foundation supported program NATEMIS (Nonlinear Acoustic Techniques for Micro-Scale Damage Diagnostics) and a Los Alamos-based international network. The main topics of both the programs and the book cover the phenomenology, theory and applications of Nonclassical Nonlinearity (NCNL). NCNL techniques have been found in recent years to be extremely powerful (up to 1000 times more than the corresponding linear techniques) in a wide range of applications, including Material Characterization, Ultrasonics, Geophysics and Maintenance and Restoration of artifacts. These techniques are being adopted as the main inspection and research tool in another European program: AERONEWS (Health monitoring of aircraft by nonlinear elastic wave propagation). In the future, the proposed Universality of NCNL is expected to extend the range of applications to numerous other fields and scientific discipline...

  12. Tone burst generator for a Non-Destructive Testing system based on ultrasonic guided waves

    OpenAIRE

    Jiménez Sánchez, Daniel

    2011-01-01

    English: This PFC provides a design of a tested and specific tone-burst generator circuit for a Non-Destructive System based on ultrasonid guided waves. This circuit includes a complementary protection circuit for the NDT system working in a pulse-echo configuration. In this paper, a brief state f art about different driving circuits employed in distinct NDE systems is presented. Castellano: El PFC proporciona un diseño electrónico específico y probado de un circuito excitador de salvas (C...

  13. Ultrasonic transverse velocity calibration of standard blocks for use in non-destructive testing

    International Nuclear Information System (INIS)

    Silva, C E R; Braz, D S; Maggi, L E; Felix, R P B Costa

    2015-01-01

    Standard blocks are employed in the verification of the equipment used in Ultrasound Non-Destructive Testing. To assure the metrology reliability of all the measurement process, it is necessary to calibrate or certify these Standard blocks. In this work, the transverse wave velocity and main dimensions were assessed according to the specifications ISO Standards. For transverse wave velocity measurement, a 5 MHz transverse wave transducer, a waveform generator, an oscilloscope and a computer with a program developed in LabVIEW TM were used. Concerning the transverse wave velocity calibration, only two Standard blocks of the 4 tested is in accordance with the standard

  14. Ultrasonic intensification of electrochemical destruction of 1,3-dinitrobenzene and 2,4-dinitrotoluene with ozone and electrocoagulation of azo-dyes

    Energy Technology Data Exchange (ETDEWEB)

    Abramov, V.O.; Abramov, O.V.; Kuznetsov, V.M. [Russian Academy of Sciences, Lab. of Ultrasonics, Moscow (Russian Federation). Kumakov Inst. of General and Inorganic Chemistry

    2002-07-01

    For the detoxification of waste and sewage, oxidation of toxic components using strong and environmentally-friendly oxidants such as hydrogen peroxide or ozone in combination with additional physicochemical processes such as ultraviolet radiation, electric discharge and ultrasonic irradiation (advanced oxidation processes) is considered to be promising. The presence of the electron-withdrawing nitro group substantially reduces the reactivity of nitroaromatics in oxidation reactions. Therefore, even when using ozone, an acceptable rate of destruction of some stable compounds such as 1,3-dinitrobenzene (DNB), 2,4-dinitrotoluene (DNT) or TNT, cannot be achieved. We have previously found that the oxidation of organic compounds by ozone or a combination of ozone with hydrogen peroxide in an ultrasonic field is enhanced in a low electric field. The objective of the present work is to study the possibility of the oxidation of DNB and DNT by ozone in an electrochemical cell under ultrasonic irradiation. (orig.)

  15. Development and improvement of synthetic imaging methods for non-destructive ultrasonic testing of complex industrial components

    International Nuclear Information System (INIS)

    Bannouf, S.

    2013-01-01

    The goal of this thesis was, initially, to evaluate phased array methods for ultrasonic Non Destructive Testing (NDT) in order to propose optimizations, or to develop new alternative methods. In particular, this works deals with the detection of defects in complex geometries and/or materials parts. The TFM (Total Focusing Method) algorithm provides high resolution images and several representations of a same defect thanks to different reconstruction modes. These properties have been exploited judiciously in order to propose an adaptive imaging method in immersion configuration. We showed that TFM imaging can be used to characterize more precisely the defects. However, this method presents two major drawbacks: the large amount of data to be processed and a low signal-to-noise ratio (SNR), especially in noisy materials. We developed solutions to these two problems. To overcome the limitation caused by the large number of signals to be processed, we propose an algorithm that defines the sparse array to activate. As for the low SNR, it can be now improved by use of virtual sources and a new filtering method based on the DORT method (Decomposition of the Time Reversal Operator). (author) [fr

  16. Fractal dimension analysis for robust ultrasonic non-destructive evaluation (NDE) of coarse grained materials

    Science.gov (United States)

    Li, Minghui; Hayward, Gordon

    2018-04-01

    Over the recent decades, there has been a growing demand on reliable and robust non-destructive evaluation (NDE) of structures and components made from coarse grained materials such as alloys, stainless steels, carbon-reinforced composites and concrete; however, when inspected using ultrasound, the flaw echoes are usually contaminated by high-level, time-invariant, and correlated grain noise originating from the microstructure and grain boundaries, leading to pretty low signal-to-noise ratio (SNR) and the flaw information being obscured or completely hidden by the grain noise. In this paper, the fractal dimension analysis of the A-scan echoes is investigated as a measure of complexity of the time series to distinguish the echoes originating from the real defects and the grain noise, and then the normalized fractal dimension coefficients are applied to the amplitudes as the weighting factor to enhance the SNR and defect detection. Experiments on industrial samples of the mild steel and the stainless steel are conducted and the results confirm the great benefits of the method.

  17. The role of ultrasonic velocity and Schmidt hammer hardness - The simple and economical non-destructive test for the evaluation of mechanical properties of weathered granite

    Science.gov (United States)

    Jobli, Ahmad Fadzil; Hampden, Ahmad Zaidi; Tawie, Rudy

    2017-08-01

    One of the most significant techniques for evaluation of rock strength is by using the simple and economical non-destructive test (NDT). Previous literatures confirm that there were good correlations between NDTs to the strength properties of granite rocks. The present work deals with the use of Ultrasonic Pulse Velocity and Schmidt Hammer Hardness test to predict the mechanical properties of weathered granite. Cylindrical specimens with the length to diameter ratio of two were prepared for this study and were characterized based on different weathering states. Each of the rock specimens was tested under non-destructive test and then followed by uniaxial compression test to assess the mechanical properties. It was found that good correlations established between the NDTs and the uniaxial compressive strength. The correlation between uniaxial compressive strength and rebound hardness number was demonstrated by exponential form; UCS = 6.31e0.057N, while linear correlations was obtained between the uniaxial compressive strength and the ultrasonic pulse velocity; UCS = 0.023Vp - 21.43. It was also noticed that the increase of uniaxial compression strength was parallel to the increase of elastic modulus and can be presented by a linear equation; UCS = 1.039Et50 + 4.252. Based on the reported results, it is clear that the mechanical properties or weathered granite can be estimated by means of non-destructive test.

  18. Design and development of an ultrasonic pulser-receiver unit for non-destructive testing of materials

    International Nuclear Information System (INIS)

    Patankar, V.H.; Joshi, V.M.

    2002-11-01

    The pulser/receiver constitutes the most vital part of an ultrasonic flaw detector or an ultrasonic imaging system used for inspection of materials. The ultrasonic properties of the material and resolution requirements govern the choice of the frequency of ultrasound that can be optimally used. The pulser/receiver in turn decides the efficiency of excitation of the transducer and the overall signal to noise ratio of the system for best sensitivity and resolution. A variety of pulsers are used in the ultrasonic instruments employed for materials inspection. This report describes a square wave type of an ultrasonic pulser-receiver unit developed at Ultrasonic Instrumentation Section, Electronics Division, BARC. It has been primarily designed for excitation of the transducer that is used with a multi-channel ultrasonic imaging system ULTIMA 100M targeted for inspection of SS403 billets, which are in turn used as the base material for fabrication of end fittings for coolant channels of pressurized heavy water nuclear reactors (PHWRs). The design of the pulser is based upon very fast MOSFETs, configured as electronic switches. The pulser is operated with a linear bipolar H.V. supply (+/- 500V max.). The receiver provides a 60 dB gain with a -3 dB BW of 40 MHz. This pulser/receiver unit has been successfully interfaced with a 4 channel ULTIMA 100 M4 multichannel ultrasonic C-scan imaging system, also designed and developed by the authors at Ultrasonic Instrumentation Section (Electronics Division, BARC) and supplied to Centre for Design and Manufacturer - CDM, BARC. This system is being regularly used in C-scan imaging mode for volumetric inspection of SS403 billets for end fittings of 500 MWe PHWRs. (author)

  19. Newly developed non-destructive testing method for evaluation of irradiation brittleness of structural materials using ultrasonic

    International Nuclear Information System (INIS)

    Ishii, Toshimitsu; Ooka, Norikazu; Kato, Yoshiaki; Saito, Junichi; Hoshiya, Taiji; Shibata, Saburo; Kobayashi, Hideo

    1999-01-01

    Surveillance testing is important to evaluate neutron irradiation embrittlement of reactor pressure vessel material for long life operation. An alternative test method for evaluating the irradiation embrittlement of the pressure vessel material will have to be proposed to support the limited number of surveillance test specimens in order to manage the plant life to be extended. In this study, ultrasonic testing for irradiated A533B-1 steel and weld metal was applied to examine material degradation nondestructively. With increasing the shift of Charpy 41 J transition temperature, ultrasonic velocity decreased and attenuation coefficient of ultrasonic wave increased. Especially, the difference of ultrasonic velocity for 5 MHz shear wave between as-received and irradiated material is corresponding to the shift of transition temperature showing material degradation. (author)

  20. Microbubbles for medical applications

    NARCIS (Netherlands)

    Segers, T.J.; de Jong, N.; Lohse, Detlef; Versluis, Michel; van den Berg, A.; Segerink, L.

    2015-01-01

    Ultrasound contrast agent (UCA) suspensions contain encapsulated microbubbles with radii ranging from 1 to 10 micrometers. The bubbles oscillate to the driving ultrasound pulse generating harmonics of the driving ultrasound frequency. This feature allows for the discrimination of non-linear bubble

  1. Building Of Training Program Of Non-Destructive Testing For Concrete Structures (Part 1: Radiographic testing; Ultrasonic pulse velocity measurement; Nuclear moisture-density gauge)

    International Nuclear Information System (INIS)

    Nguyen Le Son; Phan Chanh Vu; Pham The Hung; Vu Huy Thuc

    2007-01-01

    Non-destructive testing methods (NDT) have been identified as a strong candidate for remote sensing of concrete structures over recent years. This has accelerated the powerful development of the NDT techniques in Vietnam. Hence, there is an urgent need to promote the awareness of NDT methods which could give an improved estimate of the condition concrete. Building of training program of non-destructive testing for concrete structures is a necessary duty, in aiming to build a unified training program, possibly satisfying the requirements on training as well as researching. Under the framework of the basic VAEC project (CS/07/02-03), a training program for the first 03 NDT methods: 1. Radiographic testing; 2. Ultrasonic pulse velocity measurement; 3. Nuclear moisture- density gauge was prepared. The main products of this project include: 1. Set out 03 training notes for 03 methods; 2. Set out the practical exercises to train for 03 methods; 3. Editing a set of examination questions in aiming to familiarize with various questions in 03 trained methods; 4. Fabricating practical test specimens to demonstrate for 03 techniques. (author)

  2. Non-destructive Engineering

    International Nuclear Information System (INIS)

    Ko, Jin Hyeon; Ryu, Taek In; Ko, Jun Bin; Hwang, Yong Hwa

    2006-08-01

    This book gives descriptions of non-destructive engineering on outline of non-destructive test, weld defects, radiographic inspection radiography, ultrasonic inspection, magnetic particle testing, liquid penetrant testing, eddy current inspection method, strain measurement, acoustic emission inspection method, other non-destructive testing like leakage inspection method, and non-destructive mechanics for fault analysis such as Griffiths creaking theory, and stress analysis of creaking.

  3. Cardiac Gene Expression Knockdown Using Small Inhibitory RNA-Loaded Microbubbles and Ultrasound.

    Directory of Open Access Journals (Sweden)

    Jonathan A Kopechek

    Full Text Available RNA interference has potential therapeutic value for cardiac disease, but targeted delivery of interfering RNA is a challenge. Custom designed microbubbles, in conjunction with ultrasound, can deliver small inhibitory RNA to target tissues in vivo. The efficacy of cardiac RNA interference using a microbubble-ultrasound theranostic platform has not been demonstrated in vivo. Therefore, our objective was to test the hypothesis that custom designed microbubbles and ultrasound can mediate effective delivery of small inhibitory RNA to the heart. Microbubble and ultrasound mediated cardiac RNA interference was tested in transgenic mice displaying cardiac-restricted luciferase expression. Luciferase expression was assayed in select tissues of untreated mice (n = 14. Mice received intravenous infusion of cationic microbubbles bearing small inhibitory RNA directed against luciferase (n = 9 or control RNA (n = 8 during intermittent cardiac-directed ultrasound at mechanical index of 1.6. Simultaneous echocardiography in a separate group of mice (n = 3 confirmed microbubble destruction and replenishment during treatment. Three days post treatment, cardiac luciferase messenger RNA and protein levels were significantly lower in ultrasound-treated mice receiving microbubbles loaded with small inhibitory RNA directed against luciferase compared to mice receiving microbubbles bearing control RNA (23±7% and 33±7% of control mice, p<0.01 and p = 0.03, respectively. Passive cavitation detection focused on the heart confirmed that insonification resulted in inertial cavitation. In conclusion, small inhibitory RNA-loaded microbubbles and ultrasound directed at the heart significantly reduced the expression of a reporter gene. Ultrasound-targeted destruction of RNA-loaded microbubbles may be an effective image-guided strategy for therapeutic RNA interference in cardiac disease.

  4. Finite element simulation and experimental verification of ultrasonic non-destructive inspection of defects in additively manufactured materials

    Science.gov (United States)

    Taheri, H.; Koester, L.; Bigelow, T.; Bond, L. J.

    2018-04-01

    Industrial applications of additively manufactured components are increasing quickly. Adequate quality control of the parts is necessary in ensuring safety when using these materials. Base material properties, surface conditions, as well as location and size of defects are some of the main targets for nondestructive evaluation of additively manufactured parts, and the problem of adequate characterization is compounded given the challenges of complex part geometry. Numerical modeling can allow the interplay of the various factors to be studied, which can lead to improved measurement design. This paper presents a finite element simulation verified by experimental results of ultrasonic waves scattering from flat bottom holes (FBH) in additive manufacturing materials. A focused beam immersion ultrasound transducer was used for both the modeling and simulations in the additive manufactured samples. The samples were SS17 4 PH steel samples made by laser sintering in a powder bed.

  5. Microbubble Cavitation Imaging

    OpenAIRE

    Vignon, Francois; Shi, William T.; Powers, Jeffry E.; Everbach, E. Carr; Liu, Jinjin; Gao, Shunji; Xie, Feng; Porter, Thomas R.

    2013-01-01

    Ultrasound cavitation of microbubble contrast agents has a potential for therapeutic applications such as sonothrombolysis (STL) in acute ischemic stroke. For safety, efficacy, and reproducibility of treatment, it is critical to evaluate the cavitation state (moderate oscillations, stable cavitation, and inertial cavitation) and activity level in and around a treatment area. Acoustic passive cavitation detectors (PCDs) have been used to this end but do not provide spatial information.

  6. Microbubble Cavitation Imaging

    Science.gov (United States)

    Vignon, Francois; Shi, William T.; Powers, Jeffry E.; Everbach, E. Carr; Liu, Jinjin; Gao, Shunji; Xie, Feng; Porter, Thomas R.

    2014-01-01

    Ultrasound cavitation of microbubble contrast agents has a potential for therapeutic applications such as sonothrombolysis (STL) in acute ischemic stroke. For safety, efficacy, and reproducibility of treatment, it is critical to evaluate the cavitation state (moderate oscillations, stable cavitation, and inertial cavitation) and activity level in and around a treatment area. Acoustic passive cavitation detectors (PCDs) have been used to this end but do not provide spatial information. This paper presents a prototype of a 2-D cavitation imager capable of producing images of the dominant cavitation state and activity level in a region of interest. Similar to PCDs, the cavitation imaging described here is based on the spectral analysis of the acoustic signal radiated by the cavitating microbubbles: ultraharmonics of the excitation frequency indicate stable cavitation, whereas elevated noise bands indicate inertial cavitation; the absence of both indicates moderate oscillations. The prototype system is a modified commercially available ultrasound scanner with a sector imaging probe. The lateral resolution of the system is 1.5 mm at a focal depth of 3 cm, and the axial resolution is 3 cm for a therapy pulse length of 20 µs. The maximum frame rate of the prototype is 2 Hz. The system has been used for assessing and mapping the relative importance of the different cavitation states of a microbubble contrast agent. In vitro (tissue-mimicking flow phantom) and in vivo (heart, liver, and brain of two swine) results for cavitation states and their changes as a function of acoustic amplitude are presented. PMID:23549527

  7. Stabilization and fabrication of microbubbles: applications for medical purposes and functional materials.

    Science.gov (United States)

    Lee, Mina; Lee, Eun Yeol; Lee, Daeyeon; Park, Bum Jun

    2015-03-21

    Microbubbles with diameters ranging from a few micrometers to tens of micrometers have garnered significant attention in various applications including food processing, water treatment, enhanced oil recovery, surface cleaning, medical purposes, and material preparation fields with versatile functionalities. A variety of techniques have been developed to prepare microbubbles, such as ultrasonication, excimer laser ablation, high shear emulsification, membrane emulsification, an inkjet printing method, electrohydrodynamic atomization, template layer-by-layer deposition, and microfluidics. Generated bubbles should be immediately stabilized via the adsorption of stabilizing materials (e.g., surfactants, lipids, proteins, and solid particles) onto the gas-liquid interface to lower the interfacial tension. Such adsorption of stabilizers prevents coalescence between the microbubbles and also suppresses gas dissolution and resulting disproportionation caused by the presence of the Laplace overpressure across the gas-liquid interface. Herein, we comprehensively review three important topics of microbubbles: stabilization, fabrication, and applications.

  8. Methylene blue microbubbles as a model dual-modality contrast agent for ultrasound and activatable photoacoustic imaging

    Science.gov (United States)

    Jeon, Mansik; Song, Wentao; Huynh, Elizabeth; Kim, Jungho; Kim, Jeesu; Helfield, Brandon L.; Leung, Ben Y. C.; Goertz, David E.; Zheng, Gang; Oh, Jungtaek; Lovell, Jonathan F.; Kim, Chulhong

    2014-01-01

    Ultrasound and photoacoustic imaging are highly complementary modalities since both use ultrasonic detection for operation. Increasingly, photoacoustic and ultrasound have been integrated in terms of hardware instrumentation. To generate a broadly accessible dual-modality contrast agent, we generated microbubbles (a standard ultrasound contrast agent) in a solution of methylene blue (a standard photoacoustic dye). This MB2 solution was formed effectively and was optimized as a dual-modality contrast solution. As microbubble concentration increased (with methylene blue concentration constant), photoacoustic signal was attenuated in the MB2 solution. When methylene blue concentration increased (with microbubble concentration held constant), no ultrasonic interference was observed. Using an MB2 solution that strongly attenuated all photoacoustic signal, high powered ultrasound could be used to burst the microbubbles and dramatically enhance photoacoustic contrast (>800-fold increase), providing a new method for spatiotemporal control of photoacoustic signal generation.

  9. Ultrasonic Phased Array Assessment of the Interference Fit and Leak Path of the North Anna Unit 2 Control Rod Drive Mechanism Nozzle 63 with Destructive Validation

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Susan L.; Cinson, Anthony D.; MacFarlan, Paul J.; Hanson, Brady D.; Mathews, Royce

    2012-08-01

    The objective of this investigation was to evaluate the efficacy of ultrasonic testing (UT) for primary water leak path assessments of reactor pressure vessel (RPV) upper head penetrations. Operating reactors have experienced leakage when stress corrosion cracking of nickel-based alloy penetrations allowed primary water into the annulus of the interference fit between the penetration and the low-alloy steel RPV head. In this investigation, UT leak path data were acquired for an Alloy 600 control rod drive mechanism nozzle penetration, referred to as Nozzle 63, which was removed from the North Anna Unit 2 reactor when the RPV head was replaced in 2002. In-service inspection prior to the head replacement indicated that Nozzle 63 had a probable leakage path through the interference fit region. Nozzle 63 was examined using a phased-array UT probe with a 5.0-MHz, eight-element annular array. Immersion data were acquired from the nozzle inner diameter surface. The UT data were interpreted by comparing to responses measured on a mockup penetration with known features. Following acquisition of the UT data, Nozzle 63 was destructively examined to determine if the features identified in the UT examination, including leakage paths and crystalline boric acid deposits, could be visually confirmed. Additional measurements of boric acid deposit thickness and low-alloy steel wastage were made to assess how these factors affect the UT response. The implications of these findings for interpreting UT leak path data are described.

  10. Material characterization and non destructive testing by ultrasounds; modelling, simulation and experimental validation; Caracterisation des materiaux et controle non destructif par ultrasons; modelisation, simulation et validation experimentale

    Energy Technology Data Exchange (ETDEWEB)

    Noroy-Nadal, M H

    2002-06-15

    This memory presents the research concerning the characterization of materials and the Non Destructive Testing (N.D.T) by ultrasonics. The different topics include three steps: modeling, computations and experimental validation. The studied materials concern mainly metals. The memory is divided in four parts. The first one concerns the characterization of materials versus temperature. The determination of the shear modulus G(T) is especially studied for a large temperature range, and around the melting point. The second part is devoted to studies by photothermal devices essentially focused on the modeling of the mechanical displacement and the stress field in coated materials. In this particular field of interest, applications concern either the mechanical characterization of the coating, the defect detection in the structure and finally the evaluation of the coating adhesion. The third section is dedicated to microstructural characterization using acoustic microscopy. The evaluation of crystallographic texture is especially approached, for metallic objects obtained by forming. Before concluding and pointing out some perspectives to this work, the last section concerns the introduction of optimization techniques, applied to the material characterization by acoustic microscopy. (author)

  11. Ultrasonic testing of materials at level 2. Manual for the syllabi contained in IAEA-TECDOC-628, training guidelines in non-destructive testing techniques

    International Nuclear Information System (INIS)

    1999-01-01

    The International Atomic Energy Agency (IAEA) has been active in the promotion of non-destructive testing (NDT) technology for many years. The prime reason for this interest has been the need for stringent quality control standards for the safe operation of nuclear installations. The IAEA has successfully executed a number of regional projects of which NDT was an important part. These were the Regional Co-operative Arrangements for the Promotion of Nuclear Science and Technology in Latin America (ARCAL), the Regional Co-operative Agreement for Asia and the Pacific (RCA), the African Regional Co-operative Agreement (AFRA) and lately the NDT Regional Project in West Asia. Through these projects a large number of persons have been trained in Member States and a state of self-sufficiency in this area of technology has been achieved in many of them. There has long been a realization of the need to have well established training guidelines and related books in order, firstly, to guide IAEA experts who were involved in this training programme and, secondly, to achieve some level of international uniformity and harmonization of training materials and consequent competence of personnel. The syllabi for training courses have been published in the form of two publications, IAEA-TECDOC-407 and IAEA-TECDOC-628. IAEA-TECDOC-628, as well as most of the international standards on the subject of training and certification of NDT personnel includes ISO 9712. The next logical step is to compile the textbooks and training manuals. Work in this regard has been undertaken and a manual on radiographic testing was issued in 1992 in the Training Course Series. This publication is a continuation of that effort. Earlier training notes on this subject existed in the form of IAEA-TECDOC-462, which was compiled in accordance with the syllabus of IAEA-TECDOC-407. These fulfilled the training needs of the member countries of RCA for quite some time. The present book is in fact an expanded and

  12. Microbubble responses to a similar mechanical index with different real-time perfusion imaging techniques.

    Science.gov (United States)

    Porter, Thomas R; Oberdorfer, Joseph; Rafter, Patrick; Lof, John; Xie, Feng

    2003-08-01

    The purpose of this study was to determine differences in contrast enhancement and microbubble destruction rates with current commercially available low-mechanical index (MI) real-time perfusion imaging modalities. A tissue-mimicking phantom was developed that had vessels at 3 cm (near field) and 9 cm (far field) from a real-time transducer. Perfluorocarbon-exposed sonicated dextrose albumin microbubbles (PESDA) were injected proximal to a mixing chamber, and then passed through these vessels while the region was insonified with either pulses of alternating polarity with pulse inversion Doppler (PID) or pulses of alternating amplitude by power modulation (PM) at MIs of 0.1, 0.2 and 0.3. Effluent microbubble concentration, contrast intensity and the slope of digital contrast intensity vs. time were measured. Our results demonstrated that microbubble destruction already occurs with PID at an MI of 0.1. Contrast intensity seen with PID was less than with PM. Therefore, differences in contrast enhancement and microbubble destruction rates occur at a similar MI setting when using different real-time pulse sequence schemes.

  13. The state of the art in non destructive testing of nuclear fuel cladding tubes using ultrasonic rotary systems; on line computer and statistics

    International Nuclear Information System (INIS)

    Rauscher, Rudolf

    Nondestructive evaluation of nuclear fuel cladding by ultrasonic tests is described. Ultrasonic transducers for detection of flaws and dimensions are built in a rotary system with a speed of 8000 rpm. The testing system is adapted to a configuration consisting of two microcomputers connected to each other

  14. Ultrafast 2-dimensional image monitoring and array-based passive cavitation detection for ultrasound contrast agent destruction in a variably sized region.

    Science.gov (United States)

    Xu, Shanshan; Hu, Hong; Jiang, Hujie; Xu, Zhi'an; Wan, Mingxi

    2014-11-01

    A combined approach was proposed, based on programmable ultrasound equipment, to simultaneously monitor surviving microbubbles and detect cavitation activity during microbubble destruction in a variably sized region for use in ultrasound contrast agent (UCA)-enhanced therapeutic ultrasound applications. A variably sized focal region wherein the acoustic pressure was above the UCA fragmentation threshold was synthesized at frequencies of 3, 4, 5, and 6 MHz with a linear broadband imaging probe. The UCAs' temporal and spatial distribution during the microbubbles' destruction was monitored in a 2-dimensional imaging plane at 5 MHz and a frame rate of 400 Hz, and simultaneously, broadband noise emissions during the microbubbles' fragmentation were extracted by using the backscattered signals produced by the focused release bursts (ie, destruction pulses) themselves. Afterward, the temporal evolution of broadband noise emission, the surviving microbubbles in a region of interest (ROI), and the destruction area in a static UCA suspension were computed. Then the inertial cavitation dose, destruction rate of microbubbles in the ROI, and area of the destruction region were determined. It was found that an increasing pulse length and a decreasing transmit aperture and excitation frequency were correlated with an increased inertial cavitation dose, microbubble destruction rate, and destruction area. Furthermore, it was obvious that the microbubble destruction rate was significantly correlated with the inertial cavitation dose (P cavitation dose could be regulated by manipulating the transmission parameters. © 2014 by the American Institute of Ultrasound in Medicine.

  15. Spark channel propagation in a microbubble liquid

    Energy Technology Data Exchange (ETDEWEB)

    Panov, V. A.; Vasilyak, L. M., E-mail: vasilyak@ihed.ras.ru; Vetchinin, S. P.; Pecherkin, V. Ya.; Son, E. E. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2016-11-15

    Experimental study on the development of the spark channel from the anode needle under pulsed electrical breakdown of isopropyl alcohol solution in water with air microbubbles has been performed. The presence of the microbubbles increases the velocity of the spark channel propagation and increases the current in the discharge gap circuit. The observed rate of spark channel propagation in microbubble liquid ranges from 4 to 12 m/s, indicating the thermal mechanism of the spark channel development in a microbubble liquid.

  16. Effects of the microbubble shell physicochemical properties on ultrasound-mediated drug delivery to the brain.

    Science.gov (United States)

    Wu, Shih-Ying; Chen, Cherry C; Tung, Yao-Sheng; Olumolade, Oluyemi O; Konofagou, Elisa E

    2015-08-28

    Lipid-shelled microbubbles have been used in ultrasound-mediated drug delivery. The physicochemical properties of the microbubble shell could affect the delivery efficiency since they determine the microbubble mechanical properties, circulation persistence, and dissolution behavior during cavitation. Therefore, the aim of this study was to investigate the shell effects on drug delivery efficiency in the brain via blood-brain barrier (BBB) opening in vivo using monodisperse microbubbles with different phospholipid shell components. The physicochemical properties of the monolayer were varied by using phospholipids with different hydrophobic chain lengths (C16, C18, and C24). The dependence on the molecular size and acoustic energy (both pressure and pulse length) were investigated. Our results showed that a relatively small increase in the microbubble shell rigidity resulted in a significant increase in the delivery of 40-kDa dextran, especially at higher pressures. Smaller (3kDa) dextran did not show significant difference in the delivery amount, suggesting that the observed shell effect was molecular size-dependent. In studying the impact of acoustic energy on the shell effects, it was found that they occurred most significantly at pressures causing microbubble destruction (450kPa and 600kPa); by increasing the pulse length to deliver the 40-kDa dextran, the difference between C16 and C18 disappeared while C24 still achieved the highest delivery efficiency. These indicated that the acoustic energy could be used to modulate the shell effects. The acoustic cavitation emission revealed the physical mechanisms associated with different shells. Overall, lipid-shelled microbubbles with long hydrophobic chain length could achieve high delivery efficiency for larger molecules especially with high acoustic energy. Our study, for the first time, offered evidence directly linking the microbubble monolayer shell with their efficacy for drug delivery in vivo. Copyright © 2015

  17. On line ultrasonic integrated backscatter

    International Nuclear Information System (INIS)

    Landini, L.; Picano, E.; Mazzarisi, A.; Santarelli, F.; Benassi, A.; De Pieri, G.

    1988-01-01

    A new equipment for on-line evaluation of index based on two-dimensional integrated backscatter from ultrasonic images is described. The new equipment is fully integrated into a B-mode ultrasonic apparatus which provides a simultaneous display of conventional information together with parameters of tissue characterization. The system has been tested with a backscattering model of microbubbles in polysaccharide solution, characterized by a physiological exponential time decay. An exponential fitting to the experimental data was performed which yielded r=0.95

  18. Collective dissolution of microbubbles

    Science.gov (United States)

    Michelin, Sébastien; Guérin, Etienne; Lauga, Eric

    2018-04-01

    A microscopic bubble of soluble gas always dissolves in finite time in an undersaturated fluid. This diffusive process is driven by the difference between the gas concentration near the bubble, whose value is governed by the internal pressure through Henry's law, and the concentration in the far field. The presence of neighboring bubbles can significantly slow down this process by increasing the effective background concentration and reducing the diffusing flux of dissolved gas experienced by each bubble. We develop theoretical modeling of such diffusive shielding process in the case of small microbubbles whose internal pressure is dominated by Laplace pressure. We first use an exact semianalytical solution to capture the case of two bubbles and analyze in detail the shielding effect as a function of the distance between the bubbles and their size ratio. While we also solve exactly for the Stokes flow around the bubble, we show that hydrodynamic effects are mostly negligible except in the case of almost-touching bubbles. In order to tackle the case of multiple bubbles, we then derive and validate two analytical approximate yet generic frameworks, first using the method of reflections and then by proposing a self-consistent continuum description. Using both modeling frameworks, we examine the dissolution of regular one-, two-, and three-dimensional bubble lattices. Bubbles located at the edge of the lattices dissolve first, while innermost bubbles benefit from the diffusive shielding effect, leading to the inward propagation of a dissolution front within the lattice. We show that diffusive shielding leads to severalfold increases in the dissolution time, which grows logarithmically with the number of bubbles in one-dimensional lattices and algebraically in two and three dimensions, scaling respectively as its square root and 2 /3 power. We further illustrate the sensitivity of the dissolution patterns to initial fluctuations in bubble size or arrangement in the case

  19. Comparative testing of radiographic testing, ultrasonic testing and phased array advanced ultrasonic testing non destructive testing techniques in accordance with the AWS D1.5 bridge welding code.

    Science.gov (United States)

    2014-02-01

    A comprehensive body of non-destructive testing data was collected from steel bridge welds under real-world conditions in a fabricators shop. Three different non-destructive testing (NDT) techniques were used on each weld inspection, these being R...

  20. Microbubble acoustic signatures: bubble deflation

    NARCIS (Netherlands)

    ten Brinke, G.A.; Slump, Cornelis H.

    2006-01-01

    Ultrasound Contrast Agents (UCAs) are used in medical imaging to enhance the visibility of structures, especially blood vessels and the liver. An example application of UCAs is the detection and classification of tumors. The most common UCA consist of microbubbles, which have pronounced non-linear

  1. Ultrasound Contrast Agent Microbubble Dynamics

    NARCIS (Netherlands)

    Overvelde, M.L.J.; Vos, Henk; de Jong, N.; Versluis, Michel; Paradossi, Gaio; Pellegretti, Paolo; Trucco, Andrea

    2010-01-01

    Ultrasound contrast agents are traditionally used in ultrasound-assisted organ perfusion imaging. Recently the use of coated microbubbles has been proposed for molecular imaging applications where the bubbles are covered with a layer of targeting ligands to bind specifically to their target cells.

  2. [Molecular imaging of thrombus with microbubbles targeted to alphavbeta3-integrin using an agarose flow chamber model].

    Science.gov (United States)

    Hu, Guang-quan; Liu, Jian; Yang, Li; Yan, Yi; Wu, Jue-fei; Xie, Jia-jia; Cai, Jing-jing; Ji, Li-jing; Bin, Jian-ping

    2010-03-01

    To assess the binding ability of microbubbles targeted to alphavbeta3-integrin (MBp) for thrombus-targeted contrast-enhanced ultrasound. Targeted microbubbles were prepared by conjugating the monoclonal antibody against alphavbeta3-integrin to lipid shell of the microbubble via the avidin-biotin bridges. Equivalent isotype control microbubbles (MB) or targeted ultrasound microbubbles (MBp) were randomly added into the flow chamber. After a 30-min incubation with the thrombus fixed in an agarose flow chamber model, the thrombus was washed with a continuous flow of PBS solution (15 cm/s) for 2, 4, 6, 8 and 10 min, followed by thrombus imaging using contrast-enhanced ultrasound and measurement of the video intensity (VI) values of the images. The VI of the thrombus in MBp group was reduced by 28%-66%, while that in control MB group was decreased by 87%-94%, and the VI values of the thrombus group were significantly greater in former group at each of the time points (Pevaluation of the thrombus-binding capability of the targeted microbubble (MBp) by simulating the shear stress in vivo can be helpful for predicting the in vivo effects of ultrasonic molecular imaging using MBp.

  3. Study of different ultrasonic focusing methods applied to non destructive testing; Etude de differentes methodes de focalisation ultrasonore appliquees au controle non destructif

    Energy Technology Data Exchange (ETDEWEB)

    El Amrani, M.

    1995-11-17

    The work presented in this thesis concerns the study of different ultrasonic focusing techniques applied to Nondestructive Testing (mechanical focusing and electronic focusing) and compares their capabilities. We have developed a model to predict the ultrasonic field radiated into a solid by water-coupled transducers. The model is based upon the Rayleigh integral formulation, modified to take account the refraction at the liquid-solid interface. The model has been validated by numerous experiments in various configurations. Running this model and the associated software, we have developed new methods to optimize focused transducers and studied the characteristics of the beam generated by transducers using various focusing techniques. (author). 120 refs., 95 figs., 4 appends.

  4. Rapid Evaporation of microbubbles

    Science.gov (United States)

    Gautam, Jitendra; Esmaeeli, Asghar

    2008-11-01

    When a liquid is heated to a temperature far above its boiling point, it evaporates abruptly. Boiling of liquid at high temperatures can be explosive and destructive, and poses a potential hazard for a host of industrial processes. Explosive boiling may occur if a cold and volatile liquid is brought into contact with a hot and non-volatile liquid, or if a liquid is superheated or depressurized rapidly. Such possibilities are realized, for example, in the depressurization of low boiling point liquefied natural gas (LNG) in the pipelines or storage tanks as a result of a leak. While boiling of highly heated liquids can be destructive at macroscale, the (nearly) instantaneous pace of the process and the release of large amount of kinetic energy make the phenomena extremely attractive at microscale where it is possible to utilize the released energy to derive micromechanical systems. For instance, there is currently a growing interest in micro-explosion of liquid for generation of micro bubbles for actuation purposes. The aim of the current study is to gain a fundamental understanding of the subject using direct numerical simulations. In particular, we seek to investigate the boundary between stable and unstable nucleus growth in terms of the degree of liquid superheat and to compare the dynamics of unstable and stable growth.

  5. Microbubble smallness limited by conjunctions

    Czech Academy of Sciences Publication Activity Database

    Tesař, Václav

    Roč. 231, September (2013), s. 526-536 ISSN 1385-8947 R&D Projects: GA ČR GA13-23046S Institutional research plan: CEZ:AV0Z20760514 Institutional support: RVO:61388998 Keywords : bubbles * microbubbles * bubble coalescence Subject RIV: BK - Fluid Dynamics Impact factor: 4.058, year: 2013 http://dx.doi.org/10.1016/j.cej.2013.06.051

  6. Ultrasonic Testing

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeong Jun; Kuk, Jeong Han

    2002-02-15

    This book introduces ultrasonic testing, which tells of outline of ultrasonic testing, principle of ultrasonic testing, prosperities of ultrasonic waves, radiographic test and ultrasonic test, basic theory on ultrasonic testing, mode conversion, transmission and diffraction, ultrasonic flaw detection and probe, standard test piece and reference test piece, like KS(JIS) ASME and ASTM, classification and properties of ultrasonic testing, straight beam method, angle beam method, ASME SEC.V.Art.5 ASTMA 388 and KS B 0817 Korean industrial standard.

  7. Reversible and irreversible vascular bioeffects induced by ultrasound and microbubbles in chorioallantoic membrane model

    Science.gov (United States)

    Tarapacki, Christine; Kuebler, Wolfgang M.; Tabuchi, Arata; Karshafian, Raffi

    2017-03-01

    Background: The application of ultrasound and microbubbles at therapeutic conditions has been shown to improve delivery of molecules, cause vasoconstriction, modulate blood flow and induce a vascular shut down in in vivo cancerous tissues. The underlying mechanism has been associated with the interaction of ultrasonically-induced microbubble oscillation and cavitation with the blood vessel wall. In this study, the effect of ultrasound and microbubbles on blood flow and vascular architecture was studied using a fertilized chicken egg CAM (chorioallantoic membrane) model. Methods: CAM at day 12 of incubation (Hamburger-Hamilton stage 38-40) were exposed to ultrasound at varying acoustic pressures (160, 240 and 320 kPa peak negative pressure) in the presence of Definity microbubbles and 70 kDa FITC dextran fluorescent molecules. A volume of 50 µL Definity microbubbles were injected into a large anterior vein of the CAM prior to ultrasound exposure. The ultrasound treatment sequence consisted of 5 s exposure at 500 kHz frequency, 8 cycles and 1 kHz pulse repetition frequency with 5 s off for a total exposure of 2 minutes. Fluorescent videos and images of the CAM vasculature were acquired using intravital microscopy prior, during and following the ultrasound exposure. Perfusion was quantified by measuring the length of capillaries in a region of interest using Adobe Illustrator. Results and Discussion: The vascular bioeffects induced by USMB increased with acoustic peak negative pressure. At 160 kPa, no visible differences were observed compared to the control. At 240 kPa, a transient decrease in perfusion with subsequent recovery within 15 minutes was observed, whereas at 320 kPa, the fluorescent images showed an irreversible vascular damage. The study indicates that a potential mechanism for the transient decrease in perfusion may be related to blood coagulation. The results suggest that ultrasound and microbubbles can induce reversible and irreversible vascular

  8. Collapse dynamics of ultrasound contrast agent microbubbles

    Science.gov (United States)

    King, Daniel Alan

    Ultrasound contrast agents (UCAs) are micron-sized gas bubbles encapsulated with thin shells on the order of nanometers thick. The damping effects of these viscoelastic coatings are widely known to significantly alter the bubble dynamics for linear and low-amplitude behavior; however, their effects on strongly nonlinear and destruction responses are much less studied. This dissertation examines the behaviors of single collapsing shelled microbubbles using experimental and theoretical methods. The study of their dynamics is particularly relevant for emerging experimental uses of UCAs which seek to leverage localized mechanical forces to create or avoid specialized biomedical effects. The central component in this work is the study of postexcitation rebound and collapse, observed acoustically to identify shell rupture and transient inertial cavitation of single UCA microbubbles. This time-domain analysis of the acoustic response provides a unique method for characterization of UCA destruction dynamics. The research contains a systematic documentation of single bubble postexcitation collapse through experimental measurement with the double passive cavitation detection (PCD) system at frequencies ranging from 0.9 to 7.1 MHz and peak rarefactional pressure amplitudes (PRPA) ranging from 230 kPa to 6.37 MPa. The double PCD setup is shown to improve the quality of collected data over previous setups by allowing symmetric responses from a localized confocal region to be identified. Postexcitation signal percentages are shown to generally follow trends consistent with other similar cavitation metrics such as inertial cavitation, with greater destruction observed at both increased PRPA and lower frequency over the tested ranges. Two different types of commercially available UCAs are characterized and found to have very different collapse thresholds; lipid-shelled Definity exhibits greater postexcitation at lower PRPAs than albumin-shelled Optison. Furthermore, by altering

  9. Usage of CO2 microbubbles as flow-tracing contrast media in X-ray dynamic imaging of blood flows.

    Science.gov (United States)

    Lee, Sang Joon; Park, Han Wook; Jung, Sung Yong

    2014-09-01

    X-ray imaging techniques have been employed to visualize various biofluid flow phenomena in a non-destructive manner. X-ray particle image velocimetry (PIV) was developed to measure velocity fields of blood flows to obtain hemodynamic information. A time-resolved X-ray PIV technique that is capable of measuring the velocity fields of blood flows under real physiological conditions was recently developed. However, technical limitations still remained in the measurement of blood flows with high image contrast and sufficient biocapability. In this study, CO2 microbubbles as flow-tracing contrast media for X-ray PIV measurements of biofluid flows was developed. Human serum albumin and CO2 gas were mechanically agitated to fabricate CO2 microbubbles. The optimal fabricating conditions of CO2 microbubbles were found by comparing the size and amount of microbubbles fabricated under various operating conditions. The average size and quantity of CO2 microbubbles were measured by using a synchrotron X-ray imaging technique with a high spatial resolution. The quantity and size of the fabricated microbubbles decrease with increasing speed and operation time of the mechanical agitation. The feasibility of CO2 microbubbles as a flow-tracing contrast media was checked for a 40% hematocrit blood flow. Particle images of the blood flow were consecutively captured by the time-resolved X-ray PIV system to obtain velocity field information of the flow. The experimental results were compared with a theoretically amassed velocity profile. Results show that the CO2 microbubbles can be used as effective flow-tracing contrast media in X-ray PIV experiments.

  10. Particle migration and sorting in microbubble streaming flows

    Science.gov (United States)

    Thameem, Raqeeb; Hilgenfeldt, Sascha

    2016-01-01

    Ultrasonic driving of semicylindrical microbubbles generates strong streaming flows that are robust over a wide range of driving frequencies. We show that in microchannels, these streaming flow patterns can be combined with Poiseuille flows to achieve two distinctive, highly tunable methods for size-sensitive sorting and trapping of particles much smaller than the bubble itself. This method allows higher throughput than typical passive sorting techniques, since it does not require the inclusion of device features on the order of the particle size. We propose a simple mechanism, based on channel and flow geometry, which reliably describes and predicts the sorting behavior observed in experiment. It is also shown that an asymptotic theory that incorporates the device geometry and superimposed channel flow accurately models key flow features such as peak speeds and particle trajectories, provided it is appropriately modified to account for 3D effects caused by the axial confinement of the bubble. PMID:26958103

  11. Detection Of Cracks In Composite Materials Using Hybrid Non-Destructive Testing Method Based On Vibro-Thermography And Time-Frequency Analysis Of Ultrasonic Excitation Signal

    Directory of Open Access Journals (Sweden)

    Prokopowicz Wojciech

    2015-09-01

    Full Text Available The theme of the publication is to determine the possibility of diagnosing damage in composite materials using vibrio-thermography and frequency analysis and time-frequency of excitation signal. In order to verify the proposed method experiments were performed on a sample of the composite made in the technology of pressing prepregs. Analysis of the recorded signals and the thermograms were performed in MatLab environment. Hybrid non-destructive testing method based on thermogram and appropriate signal processing algorithm clearly showed damage in the sample composite material.

  12. A non-destructive, ultrasonic method for the determination of internal pressure and gas composition in an LWR fuel rod on-going and future programme

    International Nuclear Information System (INIS)

    Ferrandis, J.; Leveque, G.; Villard, J.

    2006-01-01

    Several possible non-destructive methods have been investigated in the past to measure the internal gas pressure e.g., measurement of 85 Kr directly, or after accumulation in the plenum by freezing with liquid nitrogen. However no satisfactory resolution to the problem has been found, so at present there is no rapid and accurate method of determining the fission gas pressure in a fuel rod without puncturing the cladding. This procedure is time-consuming and expensive and as a consequence a relatively small number of measurements are generally made compared with the number of fuel rods irradiated. In this paper it is proposed a new method for the measurement of pressure that is: Non-destructive; Non-invasive (i.e., allows re-irradiation of the measured rod); Easy to operate - directly in the reactor pool; Can be used on the critical path; Is inexpensive compared with the methods currently in use. This method is also being adapted to the on line measurement of fission gas release on fuel irradiation in research reactors. This method is based on the application of acoustic technology

  13. Are microbubbles free flowing tracers through the Myocardium? Comparison of indicator-dilution curves obtained from dye dilution and echo contrast using harmonic power Doppler imaging.

    Science.gov (United States)

    Tiemann, K; Schlosser, T; Pohl, C; Bimmel, D; Wietasch, G; Hoeft, A; Likungu, J; Vahlhaus, C; Kuntz, S; Nanda, N C; Becher, H; Lüderitz, B

    2000-01-01

    Harmonic power Doppler imaging (H-PDI) has been introduced into the field of contrast echocardiography as a contrast-specific imaging modality. However, there has been considerable skepticism as to whether H-PDI would be quantifiable, because it depends on the destruction of microbubbles and has more complex signal processing than gray scale imaging. The aim of the present study was to evaluate the relationship between the concentration of microbubbles and the resulting H-PDI signals even under conditions where bubble destruction is most likely. Furthermore, we evaluated whether microbubbles of Levovist freely pass the microcirculation, which is a prerequisite for the assessment of myocardial blood flow. A strong positive correlation was found between the H-PDI signals and the amount of microbubbles up to the onset of acoustic shadowing (r = 0. 968, Pgreen (ICG) in both a flow phantom and a working heart setup. The mean transit times (MTTs) through the myocardium of both agents were compared after a bolus injection into the left coronary artery. A close correlation was observed between 1/MTT and flow in both setups (r>0.98, Pgreen. We conclude that microbubbles fulfill the prerequisites of free flowing tracers through the myocardium. Furthermore, H-PDI technology allows a reliable assessment of time-concentration curves of air-filled microbubbles up to the onset of acoustic shadowing.

  14. Non Destructive Thermal Analysis and In Situ Investigation of Creep Mechanism of Graphite and Ceramic Composites using Phase-sensitive THz Imaging & Nonlinear Resonant Ultrasonic Spectroscopy

    International Nuclear Information System (INIS)

    Zhang, XI-Cheng; Redo-Scanchez, Albert

    2012-01-01

    In this project, we conducted a comprehensive study on nuclear graphite properties with terahertz (THz) imaging. Graphite samples from Idaho National Laboratory were carefully imaged by continuous wave (CW) THz. The CW THz imaging of graphite shows that the samples from different billet with different fabricating conditions have different pore size and structure. Based on this result, we then used a phase sensitive THz system to study the graphite properties. In this exploration, various graphite were studied. By imaging nuclear graphite samples in reflection mode at nine different incident polarization angles using THz time-domain spectroscopy, we find that different domain distributions and levels of porosity will introduce polarization dependence in THz reflectivity. Sample with higher density is less porous and has a smaller average domain distribution. As a consequence, it is less polarization-dependent and the polarization-dependent frequency is higher. The results also show that samples oxidized at higher temperatures tend to be more polarization dependent. The graphite from the external billet is more polarization dependent compared to that from the center billet. In addition, we performed laser-based ultrasonic measurements on these graphite samples. The denser, unoxidized samples allow surface acoustic waves to propagate more rapidly than in the samples that had already undergone oxidation. Therefore, for the oxidized samples, the denser samples show less polarization-dependence, higher polarization-dependent frequency, and allow the surface acoustic waves propagate faster.

  15. Experimental investigations of nonlinearities and destruction mechanisms of an experimental phospholipid-based ultrasound contrast agent.

    Science.gov (United States)

    Casciaro, Sergio; Palmizio Errico, Rosa; Errico, Rosa Palmizio; Conversano, Francesco; Demitri, Christian; Distante, Alessandro

    2007-02-01

    We sought to characterize the acoustical behavior of the experimental ultrasound contrast agent BR14 by determining the acoustic pressure threshold above which nonlinear oscillation becomes significant and investigating microbubble destruction mechanisms. We used a custom-designed in vitro setup to conduct broadband attenuation measurements at 3.5 MHz varying acoustic pressure (range, 50-190 kPa). We also performed granulometric analyses on contrast agent solutions to accurately measure microbubble size distribution and to evaluate insonification effects. Attenuation did not depend on acoustic pressure less than 100 kPa, indicating this pressure as the threshold for the appearance of microbubble nonlinear behavior. At the lowest excitation amplitude, attenuation increased during insonification, while, at higher excitation levels, the attenuation decreased over time, indicating microbubble destruction. The destruction rate changed with pressure amplitude suggesting different destruction mechanisms, as it was confirmed by granulometric analysis. Microbubbles showed a linear behavior until 100 kPa, whereas beyond this value significant nonlinearities occurred. Observed destruction phenomena seem to be mainly due to gas diffusion and bubble fragmentation mechanisms.

  16. Biosurfactants for Microbubble Preparation and Application

    OpenAIRE

    Takeo Shiina; Zengshe Liu; Mitsutoshi Nakajima; Qingyi Xu

    2011-01-01

    Biosurfactants can be classified by their chemical composition and their origin. This review briefly describes various classes of biosurfactants based on their origin and introduces a few of the most widely used biosurfactants. The current status and future trends in biosurfactant production are discussed, with an emphasis on those derived from plants. Following a brief introduction of the properties of microbubbles, recent progress in the application of microbubble technology to molecular im...

  17. Microbubble stability and applications in food

    OpenAIRE

    Rovers, T.A.M.

    2015-01-01

    Aeration of food is considered to be a good method to create a texture and mouthfeel of food products that is liked by the consumer. However, traditional foams are not stable for a prolonged time. Microbubbles are air bubbles covered with a shell that slows down disproportionation significantly and arrests coalescence. Protein stabilized microbubbles are seen as a promising new food ingredient for encapsulation, to replace fat, to create new textures, and to improve sensorial properties of fo...

  18. Measurement of real pulsatile blood flow using X-ray PIV technique with CO2 microbubbles.

    Science.gov (United States)

    Park, Hanwook; Yeom, Eunseop; Seo, Seung-Jun; Lim, Jae-Hong; Lee, Sang-Joon

    2015-03-06

    Synchrotron X-ray imaging technique has been used to investigate biofluid flows in a non-destructive manner. This study aims to investigate the feasibility of the X-ray PIV technique with CO2 microbubbles as flow tracer for measurement of pulsatile blood flows under in vivo conditions. The traceability of CO2 microbubbles in a pulsatile flow was demonstrated through in vitro experiment. A rat extracorporeal bypass loop was used by connecting a tube between the abdominal aorta and jugular vein of a rat to obtain hemodynamic information of actual pulsatile blood flows without changing the hemorheological properties. The decrease in image contrast of the surrounding tissue was also investigated for in vivo applications of the proposed technique. This technique could be used to accurately measure whole velocity field information of real pulsatile blood flows and has strong potential for hemodynamic diagnosis of cardiovascular diseases.

  19. Measurement of real pulsatile blood flow using X-ray PIV technique with CO2 microbubbles

    Science.gov (United States)

    Park, Hanwook; Yeom, Eunseop; Seo, Seung-Jun; Lim, Jae-Hong; Lee, Sang-Joon

    2015-01-01

    Synchrotron X-ray imaging technique has been used to investigate biofluid flows in a non-destructive manner. This study aims to investigate the feasibility of the X-ray PIV technique with CO2 microbubbles as flow tracer for measurement of pulsatile blood flows under in vivo conditions. The traceability of CO2 microbubbles in a pulsatile flow was demonstrated through in vitro experiment. A rat extracorporeal bypass loop was used by connecting a tube between the abdominal aorta and jugular vein of a rat to obtain hemodynamic information of actual pulsatile blood flows without changing the hemorheological properties. The decrease in image contrast of the surrounding tissue was also investigated for in vivo applications of the proposed technique. This technique could be used to accurately measure whole velocity field information of real pulsatile blood flows and has strong potential for hemodynamic diagnosis of cardiovascular diseases. PMID:25744850

  20. Microbubble Distillation for Ethanol-Water Separation

    Directory of Open Access Journals (Sweden)

    Atheer Al-yaqoobi

    2016-01-01

    Full Text Available In the current study, a novel approach for separating ethanol-water mixture by microbubble distillation technology was investigated. Traditional distillation processes require large amounts of energy to raise the liquid to its boiling point to effect removal of volatile components. The concept of microbubble distillation by comparison is to heat the gas phase rather than the liquid phase to achieve separation. The removal of ethanol from the thermally sensitive fermentation broths was taken as a case of study. Consequently the results were then compared with those which could be obtained under equilibrium conditions expected in an “ideal” distillation unit. Microbubble distillation has achieved vapour compositions higher than that which could be obtained under traditional equilibrium conditions. The separation was achieved at liquid temperature significantly less than the boiling point of the mixture. In addition, it was observed that the separation efficiency of the microbubble distillation could be increased by raising the injected air temperature, while the temperature of the liquid mixture increased only moderately. The separation efficiency of microbubble distillation was compared with that of pervaporation for the recovery of bioethanol from the thermally sensitive fermentation broths. The technology could be controlled to give high separation and energy efficiency. This could contribute to improving commercial viability of biofuel production and other coproducts of biorefinery processing.

  1. Lead-silicate glass optical microbubble resonator

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Pengfei, E-mail: pengfei.wang@dit.ie [Photonics Research Centre, Dublin Institute of Technology, Kevin Street, Dublin 8 (Ireland); Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ (United Kingdom); Ward, Jonathan; Yang, Yong; Chormaic, Síle Nic [Light-Matter Interactions Unit, OIST Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495 (Japan); Feng, Xian; Brambilla, Gilberto [Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ (United Kingdom); Farrell, Gerald [Photonics Research Centre, Dublin Institute of Technology, Kevin Street, Dublin 8 (Ireland)

    2015-02-09

    Microbubble whispering gallery resonators have the potential to become key components in a variety of active and passive photonic circuit devices by offering a range of significant functionalities. Here, we report on the fabrication, optical characterization, and theoretical analysis of lead-silicate glass and optical microbubble resonators. Evanescent field coupling to the microbubbles was achieved using a 1 μm diameter, silica microfiber at a wavelength of circa 775 nm. High Q-factor modes were efficiently excited in both single-stem and two-stem, lead-silicate glass, and microbubble resonators, with bubble diameters of 38 μm (single-stem) and 48 μm (two-stem). Whispering gallery mode resonances with Q-factors as high as 2.3 × 10{sup 5} (single-stem) and 7 × 10{sup 6} (two-stem) were observed. By exploiting the high-nonlinearity of the lead-silicate glass, this work will act as a catalyst for studying a range of nonlinear optical effects in microbubbles, such as Raman scattering and four-wave mixing, at low optical powers.

  2. Non-destructive controls

    International Nuclear Information System (INIS)

    Nouvet, A.

    1978-01-01

    The non-destructive controls permit, while respecting their integrity, the direct and individual examination of parts or complete objects as they are manufactured, as well as to follow the evolution of their eventual defects while in operation. The choice of control methods depends on the manufacturing process and shapes of parts, on the physical properties of their components as well as the nature, position and size of the defects which are likely to be detected. Whether it is a question of controls by means of ionizing radiation, flux of neutrons, ultrasons, acoustic source, sweating, magnetoscopy. Foucault currents, thermography, detection of leaks or non-destructive metallography, each has a limited field of application such that they are less competitive than complementary [fr

  3. Acoustically excited encapsulated microbubbles and mitigation of biofouling

    KAUST Repository

    Qamar, Adnan

    2017-08-31

    Provided herein is a universally applicable biofouling mitigation technology using acoustically excited encapsulated microbubbles that disrupt biofilm or biofilm formation. For example, a method of reducing biofilm formation or removing biofilm in a membrane filtration system is provided in which a feed solution comprising encapsulated microbubbles is provided to the membrane under conditions that allow the encapsulated microbubbles to embed in a biofilm. Sonication of the embedded, encapsulated microbubbles disrupts the biofilm. Thus, provided herein is a membrane filtration system for performing the methods and encapsulated microbubbles specifically selected for binding to extracellular polymeric substances (EFS) in a biofilm.

  4. Acoustic Studies on Nanodroplets, Microbubbles and Liposomes

    Science.gov (United States)

    Kumar, Krishna Nandan

    Microbubbles and droplets are nanometer to micron size biocompatible particles which are primarily used for drug delivery and contrast imaging. Our aim is to broaden the use of microbubbles from contrast imaging to other applications such as measuring blood pressure. The other goal is to develop in situ contrast agents (phase shift droplets) which can be used for applications such as cancer tumor imaging. Therefore, the focus is on developing and validating the concept using experimental and theoretical methods. Below is an overview of each of the projects performed on droplets and microbubbles. Phase shift droplets vaporizable by acoustic stimulation offer many advantages over microbubbles as contrast agents due to their higher stability and possibility of smaller sizes. In this study, the acoustic droplet vaporization (ADV) threshold of a suspension of PFP droplets (400-3000nm) was acoustically measured as a function of the excitation frequency by examining the scattered signals, fundamental, sub- and second-harmonic. This work presents the experimental methodology to determine ADV threshold. The threshold increases with frequency: 1.25 MPa at 2.25 MHz, 2.0 MPa at 5 MHz and 2.5 MPa at 10 MHz. The scattered response from droplets was also found to match well with that of independently prepared lipid-coated microbubble suspension in magnitude as well as trends above the threshold value. Additionally, we have employed classical nucleation theory (CNT) to investigate the ADV, specifically the threshold value of the peak negative pressure required for vaporization. The theoretical analysis predicts that the ADV threshold increases with increasing surface tension of the droplet core and frequency of excitation, while it decreases with increasing temperature and droplet size. The predictions are in qualitative agreement with experimental observations. A technique to measure the ambient pressure using microbubbles was developed. Here we are presenting the results of an

  5. Dynamics of micro-bubble sonication inside a phantom vessel

    KAUST Repository

    Qamar, Adnan; Samtaney, Ravi; Bull, Joseph L.

    2013-01-01

    A model for sonicated micro-bubble oscillations inside a phantom vessel is proposed. The model is not a variant of conventional Rayleigh-Plesset equation and is obtained from reduced Navier-Stokes equations. The model relates the micro-bubble oscillation dynamics with geometric and acoustic parameters in a consistent manner. It predicts micro-bubble oscillation dynamics as well as micro-bubble fragmentation when compared to the experimental data. For large micro-bubble radius to vessel diameter ratios, predictions are damped, suggesting breakdown of inherent modeling assumptions for these cases. Micro-bubble response with acoustic parameters is consistent with experiments and provides physical insight to the micro-bubble oscillation dynamics.

  6. Dynamics of micro-bubble sonication inside a phantom vessel

    KAUST Repository

    Qamar, Adnan

    2013-01-10

    A model for sonicated micro-bubble oscillations inside a phantom vessel is proposed. The model is not a variant of conventional Rayleigh-Plesset equation and is obtained from reduced Navier-Stokes equations. The model relates the micro-bubble oscillation dynamics with geometric and acoustic parameters in a consistent manner. It predicts micro-bubble oscillation dynamics as well as micro-bubble fragmentation when compared to the experimental data. For large micro-bubble radius to vessel diameter ratios, predictions are damped, suggesting breakdown of inherent modeling assumptions for these cases. Micro-bubble response with acoustic parameters is consistent with experiments and provides physical insight to the micro-bubble oscillation dynamics.

  7. Inertial cavitation threshold of nested microbubbles.

    Science.gov (United States)

    Wallace, N; Dicker, S; Lewin, Peter; Wrenn, S P

    2015-04-01

    Cavitation of ultrasound contrast agents (UCAs) promotes both beneficial and detrimental bioeffects in vivo (Radhakrishnan et al., 2013) [1]. The ability to determine the inertial cavitation threshold of UCA microbubbles has potential application in contrast imaging, development of therapeutic agents, and evaluation of localized effects on the body (Ammi et al., 2006) [2]. This study evaluates a novel UCA and its inertial cavitation behavior as determined by a home built cavitation detection system. Two 2.25 MHz transducers are placed at a 90° angle to one another where one transducer is driven by a high voltage pulser and the other transducer receives the signal from the oscillating microbubble. The sample chamber is placed in the overlap of the focal region of the two transducers where the microbubbles are exposed to a pulser signal consisting of 600 pulse trains per experiment at a pulse repetition frequency of 5 Hz where each train has four pulses of four cycles. The formulation being analyzed is comprised of an SF6 microbubble coated by a DSPC PEG-3000 monolayer nested within a poly-lactic acid (PLA) spherical shell. The effect of varying shell diameters and microbubble concentration on cavitation threshold profile for peak negative pressures ranging from 50 kPa to 2 MPa are presented and discussed in this paper. The nesting shell decreases inertial cavitation events from 97.96% for an un-nested microbubble to 19.09% for the same microbubbles nested within a 2.53 μm shell. As shell diameter decreases, the percentage of inertially cavitating microbubbles also decreases. For nesting formulations with average outer capsule diameters of 20.52, 14.95, 9.95, 5.55, 2.53, and 1.95 μm, the percentage of sample destroyed at 1 MPa was 51.02, 38.94, 33.25, 25.27, 19.09, and 5.37% respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Quality assurance of brazed copper plates through advanced ultrasonic NDE

    OpenAIRE

    Segreto, T.; Caggiano, A.; Teti, R.

    2016-01-01

    Ultrasonic non-destructive methods have demonstrated great potential for the detection of flaws in a material under examination. In particular, discontinuities produced by welding, brazing, and soldering are regularly inspected through ultrasonic techniques. In this paper, an advanced ultrasonic non-destructive evaluation technique is applied for the quality control of brazed copper cells in order to realize an accelerometer prototype for cancer proton therapy. The cells are composed of two h...

  9. Manufacturing technologies for ultrasonic transducers in a broad frequency range

    OpenAIRE

    Gebhardt, Sylvia; Hohlfeld, Kai; Günther, Paul; Neubert, Holger

    2018-01-01

    According to the application field, working frequency of ultrasonic transducers needs to be tailored to a certain value. Low frequency ultrasonic transducers with working frequencies of 1 kHz to 1 MHz are especially interesting for sonar applications, whereas high frequency ultrasonic transducers with working frequencies higher than 15 MHz are favorable for high-resolution imaging in biomedical and non-destructive evaluation. Conventional non-destructive testing devices and clinical ultrasoun...

  10. Ultrasonic guided wave for monitoring corrosion of steel bar

    Science.gov (United States)

    Liu, Xi; Qin, Lei; Huang, Bosheng

    2018-01-01

    Steel corrosion of reinforced concrete structures has become a serious problem all over the word. In this paper, the work aims at monitoring steel corrosion using ultrasonic guided wave (UGW). Ultrasonic guided wave monitoring is a dynamic and non-destructive testing technology. The advantages of ultrasonic guided wave monitoring for reinforcement corrosion are real-time, online and continuous. In addition, it can judge the different stages of steel bar corrosion, which achieved non-destructive detection.

  11. Ultrasonic testing

    Energy Technology Data Exchange (ETDEWEB)

    Song, Sung Jin [Sungkwunkwan Univ., Seoul (Korea, Republic of); Jeong, Hyun Jo [Wonkwang Univ., Iksan (Korea, Republic of)

    2004-02-15

    For the proper performance of ultrasonic testing of steel welded joints, and anisotropic material it is necessary to have sound understanding on the underlying physics. To provide such an understanding, it is beneficial to have simulation tools for ultrasonic testing. In order to address such a need, we develop effective approaches to simulate angle beam ultrasonic testing with a personal computer. The simulation is performed using ultrasonic measurement models based on the computationally efficient multi-Gaussian beams. This reach will describe the developed ultrasonic testing models together with the experimental verification of their accuracy.

  12. Microbubble stability and applications in food

    NARCIS (Netherlands)

    Rovers, T.A.M.

    2015-01-01

    Aeration of food is considered to be a good method to create a texture and mouthfeel of food products that is liked by the consumer. However, traditional foams are not stable for a prolonged time. Microbubbles are air bubbles covered with a shell that slows down disproportionation significantly

  13. Nonspherical oscilllations of ultrasound contrast agent microbubbles

    NARCIS (Netherlands)

    Dollet, B.; van der Meer, S.M.; Garbin, V.; Garbin, Valeria; de Jong, N.; Lohse, Detlef; Versluis, Michel

    2008-01-01

    The occurrence of nonspherical oscillations (or surface modes) of coated microbubbles, used as ultrasound contrast agents in medical imaging, is investigated using ultra–high-speed optical imaging. Optical tweezers designed to micromanipulate single bubbles in 3-D are used to trap the bubbles far

  14. Microbubble-Mediated Ultrasound Enhances the Lethal Effect of Gentamicin on Planktonic Escherichia coli

    Directory of Open Access Journals (Sweden)

    Han-Xiao Zhu

    2014-01-01

    Full Text Available Previous research has found that low-intensity ultrasound enhanced the lethal effect of gentamicin on planktonic E. coli. We aimed to further investigate whether microbubble-mediated low-intensity ultrasound could further enhance the antimicrobial efficacy of gentamicin. The planktonic E. coli (ATCC 25922 was distributed to four different interventions: control (GCON, microbubble only (GMB, ultrasound only (GUS, and microbubble-mediated ultrasound (GMUS. Ultrasound was applied with 100 mW/cm2 (average intensity and 46.5 KHz, which presented no bactericidal activity. After 12 h, plate counting was used to estimate the number of bacteria, and bacterial micromorphology was observed with transmission electron microscope. The results showed that the viable counts of E. coli in GMUS were decreased by 1.01 to 1.42 log10 CFU/mL compared with GUS (P<0.01. The minimal inhibitory concentration (MIC of gentamicin against E. coli was 1 μg/mL in the GMUS and GUS groups, lower than that in the GCON and GMB groups (2 μg/mL. Transmission electron microscopy (TEM images exhibited more destruction and higher thickness of bacterial cell membranes in the GMUS than those in other groups. The reason might be the increased permeability of cell membranes for gentamicin caused by acoustic cavitation.

  15. Aggregate formation affects ultrasonic disruption of microalgal cells.

    Science.gov (United States)

    Wang, Wei; Lee, Duu-Jong; Lai, Juin-Yih

    2015-12-01

    Ultrasonication is a cell disruption process of low energy efficiency. This study dosed K(+), Ca(2+) and Al(3+) to Chlorella vulgaris cultured in Bold's Basal Medium at 25°C and measured the degree of cell disruption under ultrasonication. Adding these metal ions yielded less negatively charged surfaces of cells, while with the latter two ions large and compact cell aggregates were formed. The degree of cell disruption followed: control=K(+)>Ca(2+)>Al(3+) samples. Surface charges of cells and microbubbles have minimal effects on the microbubble number in the proximity of the microalgal cells. Conversely, cell aggregates with large size and compact interior resist cell disruption under ultrasonication. Staining tests revealed high diffusional resistance of stains over the aggregate interior. Microbubbles may not be effective generated and collapsed inside the compact aggregates, hence leading to low cell disruption efficiencies. Effective coagulation/flocculation in cell harvesting may lead to adverse effect on subsequent cell disruption efficiency. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Case studies in ultrasonic testing

    International Nuclear Information System (INIS)

    Prasad, V.; Satheesh, C.; Varde, P.V.

    2015-01-01

    Ultrasonic testing is widely used Non Destructive Testing (NDT) method and forms the essential part of In-service inspection programme of nuclear reactors. Main application of ultrasonic testing is for volumetric scanning of weld joints followed by thickness gauging of pipelines and pressure vessels. Research reactor Dhruva has completed the first In Service Inspection programme in which about 325 weld joints have been volumetrically scanned, in addition to thickness gauging of 300 meters of pipe lines of various sizes and about 24 nos of pressure vessels. Ultrasonic testing is also used for level measurements, distance measurements and cleaning and decontamination of tools. Two case studies are brought out in this paper in which ultrasonic testing is used successfully for identification of butterfly valve opening status and extent of choking in pipe lines in Dhruva reactor systems

  17. Ultrasonic physics

    CERN Document Server

    Richardson, E G

    1962-01-01

    Ultrasonic Physics, Second Edition, provides an introduction to the fundamental principles of ultrasonic physics. The book opens with a discussion of the sources of ultrasound. This is followed by separate chapters on the properties and detection of ultrasonic radiation; measurement of propagation constants, i.e., the velocity and absorption, of ultrasound; ultrasound propagation in gases, liquids, and solids; and ultrasound propagation in aerosols, suspensions, and emulsions. The final chapter covers miscellaneous physical and physico-chemical actions, including dispersion and coagulation of

  18. An Ultrasonic Wireless Sensor Network for Data Communication and Structural Health Monitoring, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Typical Structural Health Monitoring (SHM) uses embedded ultrasonic transducers exclusively for non-destructive evaluation (NDE) purposes, whereas data transfer is...

  19. Tunable microbubble generator using electrolysis and ultrasound

    OpenAIRE

    Younes Achaoui; Khaled Metwally; Damien Fouan; Zoubida Hammadi; Roger Morin; Eric Debieu; Cédric Payan; Serge Mensah

    2017-01-01

    This letter reports on a method for producing on demand calibrated bubbles in a non-chemically controlled solution using localized micro-electrolysis and ultrasound. Implementing a feedback loop in the process leads to a point source of stable mono-dispersed microbubbles. This approach overcomes the inertial constraints encountered in microfluidics with the possibility to produce from a single to an array of calibrated bubbles. Moreover, this method avoids the use of additional surfactant tha...

  20. Destructive distillation

    Energy Technology Data Exchange (ETDEWEB)

    Allison, C A

    1906-05-22

    The invention relates to an apparatus in which the destructive distillation or coking of coal, peat, shale, etc., is carried out by means of a current of hot gases at a temperature of 700--800/sup 0/F., as described in Specification No. 11,925, A.D. 1906.

  1. Study of a system devoted for ultrasonic non destructive testing of complex geometry pieces using smart contacts transducers; Etude d'un systeme de controle par ultrasons des pieces de geometrie conplexe a l'aide de traducteurs contacts intelligents

    Energy Technology Data Exchange (ETDEWEB)

    Chatillon, S

    2000-07-01

    This work is devoted to the enhancement of the ultrasonic non destructive testing in contact of nuclear components with complex geometry. In service inspections of such components performed with conventional probes present limited performances: variations in sensitivity, due to unmatched contact, incorrect characterization of the defect, because of the disorientations of the transducer during its displacement, and uncovered scan area when the geometry of the components disturbs the displacement of the transducer. We propose a new concept of smart transducer to improve the performances of such inspections. The radiating surface is flexible to optimize the sensitivity of the testing. Using the measure of the radiating surface distortion, performed by a specific instrumentation, phased array techniques allow the control of the transmitted beam to optimize the defect localization and characterization. Thus, this system is self-contained. We present the different steps involved to develop this system and its experimental validation. A computing model is extended to predict the field transmitted by a flexible contact transducer. This model is used to optimize the radiating surface of a jointed transducer. A delay law optimizing algorithm is developed to ensure the control of the transmitted beam. At last, a method and the associated instrumentation designed to measure the radiating surface distortion are proposed. Experimental Measures in the through-transmission mode validate the ability of this system to control the field transmitted through complex interfaces. At last, inspections in the pulse-echo mode are performed on a specimen with an irregular profile, representative of a real component inspected on site, and artificial embedded reflectors. Two control configurations are used. In the first one, the transducer is displaced along the surface, in the second one, the transducer is fixed and the region of interest is scanned using beam steering. The results show that

  2. Local defect resonance for sensitive non-destructive testing

    Science.gov (United States)

    Adebahr, W.; Solodov, I.; Rahammer, M.; Gulnizkij, N.; Kreutzbruck, M.

    2016-02-01

    Ultrasonic wave-defect interaction is a background of ultrasound activated techniques for imaging and non-destructive testing (NDT) of materials and industrial components. The interaction, primarily, results in acoustic response of a defect which provides attenuation and scattering of ultrasound used as an indicator of defects in conventional ultrasonic NDT. The derivative ultrasonic-induced effects include e.g. nonlinear, thermal, acousto-optic, etc. responses also applied for NDT and defect imaging. These secondary effects are normally relatively inefficient so that the corresponding NDT techniques require an elevated acoustic power and stand out from conventional ultrasonic NDT counterparts for their specific instrumentation particularly adapted to high-power ultrasonic. In this paper, a consistent way to enhance ultrasonic, optical and thermal defect responses and thus to reduce an ultrasonic power required is suggested by using selective ultrasonic activation of defects based on the concept of local defect resonance (LDR). A strong increase in vibration amplitude at LDR enables to reliably detect and visualize the defect as soon as the driving ultrasonic frequency is matched to the LDR frequency. This also provides a high frequency selectivity of the LDR-based imaging, i.e. an opportunity of detecting a certain defect among a multitude of other defects in material. Some examples are shown how to use LDR in non-destructive testing techniques, like vibrometry, ultrasonic thermography and shearography in order to enhance the sensitivity of defect visualization.

  3. Facilitating Intracellular Drug Delivery by Ultrasound-Activated Microbubbles

    NARCIS (Netherlands)

    Lammertink, BHA

    2017-01-01

    The goal of this thesis was to investigate the combination of ultrasound and microbubbles (USMB) for intracellular delivery of (model) drugs in vitro. We have focused on clinically approved drugs, i.e. cisplatin, and microbubbles, i.e. SonoVue™, to facilitate clinical translation. In addition, model

  4. Destructive distillation

    Energy Technology Data Exchange (ETDEWEB)

    Cosden, S; Cosden, J S

    1937-09-08

    A means and process are described for the destructive distillation of solid carbonaceous materials in which the process comprises charging the material, in a finely divided condition into a stream of hot combustion gases, and allows the hot gases to act pyrolytically on the organic compounds contained in the material, separating the volatile liberated constituents from residuary constituents. Hot reaction gases are generated by fuel ignition means in a generator and are immediately intermingled with comminuted carbonaceous material from a hopper, in a narrow conduit. The mixture of material and reaction fluid is then passed through an elongated confined path, which is exteriorly heated by the combustion chamber of the furnace, where the destructive distillation is effected. Volatile and solid constituents are separated in the chamber, and the volatile constituents are fractionated and condensed.

  5. Ultrasound triggered drug delivery with liposomal nested microbubbles.

    Science.gov (United States)

    Wallace, N; Wrenn, S P

    2015-12-01

    When ultrasound contrast agent microbubbles are nested within a liposome, damage to the liposome membrane caused by both stable and inertial cavitation of the microbubble allows for release of the aqueous core of the liposome. Triggered release was not accomplished unless microbubbles were present within the liposome. Leakage was tested using fluorescence assays developed specifically for this drug delivery vehicle and qualitative measurements using an optical microscope. These studies were done using a 1 MHz focused ultrasound transducer while varying parameters including peak negative ultrasound pressure, average liposome diameter, and microbubble concentration. Two regimes exist for membrane disruption caused by cavitating microbubbles. A faster release rate, as well as permanent membrane damage are seen for samples exposed to high pressure (2.1-3.7 MPa). A slower release rate and dilation/temporary poration are characteristic of stable cavitation for low pressure studies (0.54-1.7 MPa). Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Destructive distillation

    Energy Technology Data Exchange (ETDEWEB)

    1938-07-05

    A process and apparatus for the destructive distillation at low temperature of mineral or organic material particularly oil shale, is given in which the process comprises distilling the material in a horizontal gaseous stream, subjecting the hot residues to the action of a gaseous stream containing a predetermined amount of oxygen so as to burn, at least partly, the carbon-containing substances, and the process uses the gases from this combustion for the indirect heating of the gases serving for the distillation.

  7. Real-time contrast ultrasound muscle perfusion imaging with intermediate-power imaging coupled with acoustically durable microbubbles.

    Science.gov (United States)

    Seol, Sang-Hoon; Davidson, Brian P; Belcik, J Todd; Mott, Brian H; Goodman, Reid M; Ammi, Azzdine; Lindner, Jonathan R

    2015-06-01

    There is growing interest in limb contrast-enhanced ultrasound (CEU) perfusion imaging for the evaluation of peripheral artery disease. Because of low resting microvascular blood flow in skeletal muscle, signal enhancement during limb CEU is prohibitively low for real-time imaging. The aim of this study was to test the hypothesis that this obstacle can be overcome by intermediate- rather than low-power CEU when performed with an acoustically resilient microbubble agent. Viscoelastic properties of Definity and Sonazoid were assessed by measuring bulk modulus during incremental increases in ambient pressure to 200 mm Hg. Comparison of in vivo microbubble destruction and signal enhancement at a mechanical index (MI) of 0.1 to 0.4 was performed by sequential reduction in pulsing interval from 10 to 0.05 sec during limb CEU at 7 MHz in mice and 1.8 MHz in dogs. Destruction was also assessed by broadband signal generation during passive cavitation detection. Real-time CEU perfusion imaging with destruction-replenishment was then performed at 1.8 MHz in dogs using an MI of 0.1, 0.2, or 0.3. Sonazoid had a higher bulk modulus than Definity (66 ± 12 vs 29 ± 2 kPa, P = .02) and exhibited less inertial cavitation (destruction) at MIs ≥ 0.2. On in vivo CEU, maximal signal intensity increased incrementally with MI for both agents and was equivalent between agents except at an MI of 0.1 (60% and 85% lower for Sonazoid at 7 and 1.8 MHz, respectively, P power imaging coupled with a durable microbubble contrast agent. Copyright © 2015 American Society of Echocardiography. All rights reserved.

  8. Ultrasonic inspection

    International Nuclear Information System (INIS)

    Satittada, Gannaga

    1984-01-01

    Ultrasonic inspection is one of the most widely used methods for nondestructive inspection. The beam of high-frequency sound wave, ultrasonic wave, is introduced into the material. It travels through the material with some attendant loss of energy and can be reflected at interfaces. The reflected beam is detected and analyzed. Ultrasonic inspection is used to detect flaws in metal parts as well as in welded, brazed and bonded joints during research work and developing production and service. It is also used to detect and locate porosity, pipe, and flakes. In addition, it can be used for the measurement of metal thickness. Ultrasonic inspection is therefore used for quality control and material inspection in all major industries

  9. Ultrasonic mammography

    International Nuclear Information System (INIS)

    Hueneke, B.

    1982-01-01

    608 women are examined by means of ultrasonic mammography during the period of 1 year. 432 patients were examined with the compound method with the U.I. Octoson, a water tank scanner, and 176 patients with the real time method with a directly connected linear-array-scanner. The following results were obtained at the end of the examination period: In the ultrasonic and also in the X-ray mammogram tumour diameters can be determined with an error rate of +- 30%. In the diagnosing of carcinomas, a significant dependence of the exactness on the sice of the tumour is found for the combination of the five methods tested (clinical examination, X-ray mammography, ultrasonic mammography, thermography, cytology). Classifying the individual methods with regard to their exactness, X-ray mammography ranks in front of ultrasonic mammography. Mastopathic changes in the breast can be screened by means of ultrasonic mammography. The structure of the changes can be determined more exactly than with an X-ray picture which is due to the possibility of differentiating solid and cystic structures. In diagnosing fibro-adenomas and establishing diagnoses on young women with dense gland bodies, ultrasonic mammography is superior to radiology both in the ability of screening a finding of a fibro-adenoma (US=88%, X-ray=75%) and in the possibility of classifying it as ''more benign than malignant''. (orig./MG) [de

  10. Minimising microbubble size through oscillation frequency control

    Czech Academy of Sciences Publication Activity Database

    Brittle, S.; Deasi, P.; Ng, W. Ch.; Dunbar, A.; Howell, R.; Tesař, Václav; Zimmerman, W. B.

    2015-01-01

    Roč. 104, December (2015), s. 357-366 ISSN 0263-8762 Institutional support: RVO:61388998 Keywords : microbubbles * process intensification * transfer phenomena Subject RIV: BK - Fluid Dynamics Impact factor: 2.525, year: 2015 http://ac.els-cdn.com/S0263876215002993/1-s2.0-S0263876215002993-main.pdf?_tid=4fca5bdc-9e5f-11e5-85c5-00000aab0f02&acdnat=1449656970_b6957d7afd64592d184a978b367e8e2a

  11. Tunable microbubble generator using electrolysis and ultrasound

    Science.gov (United States)

    Achaoui, Younes; Metwally, Khaled; Fouan, Damien; Hammadi, Zoubida; Morin, Roger; Debieu, Eric; Payan, Cédric; Mensah, Serge

    2017-01-01

    This letter reports on a method for producing on demand calibrated bubbles in a non-chemically controlled solution using localized micro-electrolysis and ultrasound. Implementing a feedback loop in the process leads to a point source of stable mono-dispersed microbubbles. This approach overcomes the inertial constraints encountered in microfluidics with the possibility to produce from a single to an array of calibrated bubbles. Moreover, this method avoids the use of additional surfactant that may modify the composition of the host fluid. It impacts across a broad range of scientific domains from bioengineering, sensing to environment.

  12. Tunable microbubble generator using electrolysis and ultrasound

    Directory of Open Access Journals (Sweden)

    Younes Achaoui

    2017-01-01

    Full Text Available This letter reports on a method for producing on demand calibrated bubbles in a non-chemically controlled solution using localized micro-electrolysis and ultrasound. Implementing a feedback loop in the process leads to a point source of stable mono-dispersed microbubbles. This approach overcomes the inertial constraints encountered in microfluidics with the possibility to produce from a single to an array of calibrated bubbles. Moreover, this method avoids the use of additional surfactant that may modify the composition of the host fluid. It impacts across a broad range of scientific domains from bioengineering, sensing to environment.

  13. Computer simulation of ultrasonic waves in solids

    International Nuclear Information System (INIS)

    Thibault, G.A.; Chaplin, K.

    1992-01-01

    A computer model that simulates the propagation of ultrasonic waves has been developed at AECL Research, Chalk River Laboratories. This program is called EWE, short for Elastic Wave Equations, the mathematics governing the propagation of ultrasonic waves. This report contains a brief summary of the use of ultrasonic waves in non-destructive testing techniques, a discussion of the EWE simulation code explaining the implementation of the equations and the types of output received from the model, and an example simulation showing the abilities of the model. (author). 2 refs., 2 figs

  14. Quality control of disinfection in ultrasonic baths

    Energy Technology Data Exchange (ETDEWEB)

    Schoene, H. [Technical University Dresden (Germany). Faculty of Mechanical Engineering; Jatzwauk, L. [University Hospital of the Technical University Dresden (Germany). Abt. Krankenhaushygiene

    2002-07-01

    Numerous investigations under laboratory conditions confirmed the microbicidal efficacy of ultrasonication. Morphological destruction was shown on bacteria and fungi as well as on different virus species. Ultrasonic treatment seems to increase the effect of different antibiotics and disinfectants. Reasons for this synergism are largely unknown and uninvestigated, but the active principle seems to bee the dispersing effect of ultrasonication in combination with the destruction of cell wall or cell membrane. Unfortunately no validation of test conditions exists for most of these investigations, regarding intensity and frequency of ultrasonic waves, temperature of liquid medium and measurement of cavitation which is an essential part of physical and chemical effects in ultrasonic baths. In contrast to most laboratory experiments sound density of ultrasound for treatment of medical instruments is below 1 W/cm{sup 2} because instruments will be destroyed under stronger ultrasonic conditions. The frequency is below 50 KHz. This paper describes bactericidal and fungicidal effects of low- intensity-ultrasonication and its synergistical support to chemical disinfection. (orig.)

  15. A Comparative Analysis of the Rebound Hammer and Ultrasonic ...

    African Journals Online (AJOL)

    This work presents a study on the comparison between some non-destructive testing tech-niques (Rebound Hammer and Ultrasonic Pulse Velocity). Tests were performed to com-pare the accuracy between the rebound hammer and the ultrasonic pulse velocity methodin estimating the strength of concrete. Eighty samples ...

  16. Study of ultrasonic non destructive testing methods adapted to the sizing and the characterization of defects located in low thickness materials: analysis of the corner effect; Etude de methodes ultrasonores adaptees au dimensionnement et a la caracterisation des defauts dans des structures de faibles epaisseurs: analyse de l`effet de coin

    Energy Technology Data Exchange (ETDEWEB)

    Roy, O.

    1994-12-14

    This work is devoted to the enhancement of non destructive testing using ultrasound. It concerns especially the inspection of steam generator tubes located in water pressure reactors. The study motivation is the sizing of defects such as surface breaking cracks. Because of the low thickness of tubes, at least two corner echoes result from an inspection: one comes from the reflection of the ultrasonic beam on the defect and on the inner surface, the other comes from the reflection on the defect and on the outer surface. In order to size the defect, we consider the corner echo related to the surface opposite to the defect. We present experimental results showing that this corner echo depends on the position and the size of the defect. Then we carry out a theoretical model in order to predict the corner effect echographic response. A simplified version of that model only considers the amplitude distribution in the ultrasonic beam. It allows to calculate the amplitude recorded by the transducer during its displacement, for different sizes of defect. The echo-dynamic curves we obtain are quite representative of the experimental curves. We explain how to size the ligament by minimizing the difference between experiment and simulation. A second version of the model is based on the impulse response formalism. It allows to understand and to predict changes on waveforms resulting from corner effect for different positions of the transducer. (Author). 41 refs., 76 figs., 8 tabs.

  17. Ambient pressure sensitivity of microbubbles investigated through a parameter study

    DEFF Research Database (Denmark)

    Andersen, Klaus Scheldrup; Jensen, Jørgen Arendt

    2009-01-01

    Measurements on microbubbles clearly indicate a relation between the ambient pressure and the acoustic behavior of the bubble. The purpose of this study was to optimize the sensitivity of ambient pressure measurements, using the subharmonic component, through microbubble response simulations....... The behavior of two microbubbles corresponding to two different contrast agents was investigated as a function of driving pulse and ambient overpressure, pov. Simulations of Levovist using a rectangular driving pulse show an almost linear reduction in the subharmonic component as pov is increased. For a 20...... found, although the reduction is not completely linear as a function of the ambient pressure....

  18. Destructive, distillation

    Energy Technology Data Exchange (ETDEWEB)

    Jameson, J

    1882-10-23

    The apparatus employed resembles a reverberatory furnace, having a brickwork chamber with pipes or passages leading from the bottom, through which gases and vapors, arising from destructive distillation or heating of the materials with which the chamber is charged to a certain depth, are drawn by suction produced by a fan or blower. The materials are heated from above by firegates admitted from a separate furnace or fireplace. When shale is thus treated, to obtain burning gas, oil, and ammonia, the suction may be so regulated as to give preponderance to whichever product is desired, the depth of material treated being also concerned in the result. The process is applicable also in the treatment of coal pit refuse, sawdust, peat, and other matters, to obtain volatile products; in burning limestone to obtain carbon dioxide; and in roasting ores. Reference is made to a former Specification for coking coal, No. 1947, A. D. 1882.

  19. Distillation, destructive

    Energy Technology Data Exchange (ETDEWEB)

    Walton, G

    1865-05-16

    A retort for the destructive distillation of coal, shale, whereby hydrocarbons are produced, is described. The vertical retort is provided with a charging door, a discharging door, an outlet leading to the condensing plant, an inclined bottom, and a perforated cage to facilitate the escape of the vapor and to regulate the amount of materials operated upon in the retort. The upper part of the cage is conical to deflect the materials fed in by the door and the lower part is also slightly conical to facilitate emptying the retort. The bottom may incline from both back and front, and also from the sides to the center. The apparatus is heated from below, and the flues pass all round the lower part of the retort.

  20. Ultrasonic neuromodulation

    Science.gov (United States)

    Naor, Omer; Krupa, Steve; Shoham, Shy

    2016-06-01

    Ultrasonic waves can be non-invasively steered and focused into mm-scale regions across the human body and brain, and their application in generating controlled artificial modulation of neuronal activity could therefore potentially have profound implications for neural science and engineering. Ultrasonic neuro-modulation phenomena were experimentally observed and studied for nearly a century, with recent discoveries on direct neural excitation and suppression sparking a new wave of investigations in models ranging from rodents to humans. In this paper we review the physics, engineering and scientific aspects of ultrasonic fields, their control in both space and time, and their effect on neuronal activity, including a survey of both the field’s foundational history and of recent findings. We describe key constraints encountered in this field, as well as key engineering systems developed to surmount them. In closing, the state of the art is discussed, with an emphasis on emerging research and clinical directions.

  1. Ultrasonic flowmeters

    International Nuclear Information System (INIS)

    Wittekind, W.D.

    1979-01-01

    A prototype ultrasonic flowmeter was assembled and tested. The theoretical basis of this prototype ultrasonic flowmeter is reviewed; the equipment requirements for a portable unit are discussed; the individual electronic modules contained in the prototype are described; the operating procedures and configuration are explained; and the data from preliminary calibrations are presented. The calibration data confirm that the prototype operates according to theoretical predictions and can indeed provide nonintrusive flow measurements to predicted accuracies for pipes larger than two inches, under single phase stable flow conditions

  2. Acoustically excited encapsulated microbubbles and mitigation of biofouling

    KAUST Repository

    Qamar, Adnan; Fortunato, Luca; Leiknes, TorOve

    2017-01-01

    Provided herein is a universally applicable biofouling mitigation technology using acoustically excited encapsulated microbubbles that disrupt biofilm or biofilm formation. For example, a method of reducing biofilm formation or removing biofilm in a

  3. Theragnostic ultrasound using microbubbles in the treatment of prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hak Jong; Yoon, Young Il; Bae, Yun Jung [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2016-08-15

    The use of gas-filled microbubbles in perfusion monitoring as intravascular ultrasound contrast agents has recently become more common. Additionally, microbubbles are employed as carriers of pharmaceutical substances or genes. Microbubbles have great potential to improve the delivery of therapeutic materials into cells and to modify vascular permeability, causing increased extravasation of drugs and drug carriers. Prostate cancer is the most common neoplasm in Europe and America, with an incidence twice to three times that of lung and colorectal cancer. Its incidence is still rising in Asian countries, including Japan and Korea. In this review, we present current strategies regarding the synthesis of microbubbles with targeted ligands on their surfaces, with a focus on prostate cancer.

  4. Real-Time Two-Dimensional Imaging of Microbubble Cavitation

    NARCIS (Netherlands)

    Vignon, F.; Shi, W.T.; Powers, J.E.; Liu, J.; Drvol, L.; Lof, J.; Everbach, C.; Gao, S.; Xie, F.; Porter, T.

    2011-01-01

    Ultrasound cavitation of microbubble contrast agents has a potentialfor therapeutic applications, including sonothrombolysis in acute ischemic stroke. For safety, efficacy, and reproducibility of treatment, it is critical to evaluate the cavitation state (e.g. stable versus inertial forms of

  5. Modeling photothermal and acoustical induced microbubble generation and growth.

    Science.gov (United States)

    Krasovitski, Boris; Kislev, Hanoch; Kimmel, Eitan

    2007-12-01

    Previous experimental studies showed that powerful heating of nanoparticles by a laser pulse using energy density greater than 100 mJ/cm(2), could induce vaporization and generate microbubbles. When ultrasound is introduced at the same time as the laser pulse, much less laser power is required. For therapeutic applications, generation of microbubbles on demand at target locations, e.g. cells or bacteria can be used to induce hyperthermia or to facilitate drug delivery. The objective of this work is to develop a method capable of predicting photothermal and acoustic parameters in terms of laser power and acoustic pressure amplitude that are needed to produce stable microbubbles; and investigate the influence of bubble coalescence on the thresholds when the microbubbles are generated around nanoparticles that appear in clusters. We develop and solve here a combined problem of momentum, heat and mass transfer which is associated with generation and growth of a microbubble, filled with a mixture of non-vaporized gas (air) and water vapor. The microbubble's size and gas content vary as a result of three mechanisms: gas expansion or compression, evaporation or condensation on the bubble boundary, and diffusion of dissolved air in the surrounding water. The simulations predict that when ultrasound is applied relatively low threshold values of laser and ultrasound power are required to obtain a stable microbubble from a single nanoparticle. Even lower power is required when microbubbles are formed by coalescence around a cluster of 10 nanoparticles. Laser pulse energy density of 21 mJ/cm(2) is predicted for instance together with acoustic pressure of 0.1 MPa for a cluster of 10 or 62 mJ/cm(2) for a single nanoparticle. Those values are well within the safety limits, and as such are most appealing for targeted therapeutic purposes.

  6. Destructive distillation

    Energy Technology Data Exchange (ETDEWEB)

    Young, W

    1881-04-12

    Destructive distillation of shale for the manufacture of mineral oil and ammonia is described. The retorts are arranged in benches, each retort being placed over its own combustion chamber into which the spent shale is discharged and consumed in heating the next charge as described in Specification No. 1578, A. D. 1880. Two forms of retorts are shown, each consisting of two retorts placed above and communicating with one another, the upper being employed to distill the oil at a low red heat, and the lower to eliminate the nitrogen in the form of ammonia at a much higher temperature. The retorts are divided by a sliding damper and have an outlet for the passage of the products placed at the junction. The retorts have an outlet at the top for the escape of the products. Each retort has an opening closed by a cover for charging and a door for discharging. The products of combustion from the combustion chambers pass through ports to a chamber surrounding the lower retorts and thence through ports in the division wall controlled by dampers into the chamber surrounding the upper retorts, whence they pass through flues to the chimney. Around the bottom of each retort are openings communicating with a chamber to which steam is admitted through a valve from a pipe preferably placed in a coil in the flue.

  7. Distillation, destructive

    Energy Technology Data Exchange (ETDEWEB)

    Young, W; Fyfe, J

    1897-06-03

    Improvements in retorts of the class described in Specification No. 1377, A. D. 1882, for the destructive distillation of shale are disclosed. The retorts are provided with enlarged multiple hoppers for the reception of the fresh shale, and with enlarged chambers for the reception of the exhausted shale. The hoppers are built up of steel plates, and are bolted at the bottom to flanges on the upper ends of the retorts so as to permit of differential expansion. The shale is fed continuously into the retorts by rods or chains carried by a rocking shaft, or by a slit tube attached to a rocking shaft, and in connection with the hydraulic main. The spent shale is discharged into the receiving chambers by means of a series of prongs extending through a grating and carried by a rocking shaft actuated by levers engaging with reciprocating bars. In an alternative arrangement, the pronged rocking shafts are replaced by worms or screws formed into one half with a right-hand thread and the other half with a left-hand thread.

  8. Distillation, destructive

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, J M

    1884-06-03

    The invention relates to retorts for the destructive distillation of shale, dross, and other carbonaceous or oleaginous materials, and for the distillation and carbonization of sawdust, shavings, tan bark, and the like. The material is fed from a trapped hopper on a series of trays or casings of cast iron or other material, separated by flue spaces and arranged in a tier round a vertical rotating shaft passing through tubular pieces cast on the casings. The shaft is fitted with arms which carry stirring-blades so disposed that the material is shifted from side to side and slowly fed towards the ducts through which it passes to the casing next below, and is finally withdrawn from the apparatus by a pipe, which may be trapped or otherwise. Furnace gases are admitted through openings in the enclosing brickwork having settings to support the casings, the lowermost of which may be fitted below the inlet for furnace gases and their contents cooled by the circulation of cold water round them. The gaseous or volatile products of distillation pass to a condenser by means of openings and the pipe, which may be formed in sections to obtain access to the casings, or doors may be provided for this purpose. The ducts may be arranged alternately at the edge and center of the casings, which may be jacketed, and heated air or steam may be employed instead of furnace gases. Means may also be provided for admitting superheated steam into one or more of the casings.

  9. Dynamics of microbubble oscillators with delay coupling

    Science.gov (United States)

    Heckman, C. R.; Sah, S. M.; Rand, R. H.

    2010-10-01

    We investigate the stability of the in-phase mode in a system of two delay-coupled bubble oscillators. The bubble oscillator model is based on a 1956 paper by Keller and Kolodner. Delay coupling is due to the time it takes for a signal to travel from one bubble to another through the liquid medium that surrounds them. Using techniques from the theory of differential-delay equations as well as perturbation theory, we show that the equilibrium of the in-phase mode can be made unstable if the delay is long enough and if the coupling strength is large enough, resulting in a Hopf bifurcation. We then employ Lindstedt's method to compute the amplitude of the limit cycle as a function of the time delay. This work is motivated by medical applications involving noninvasive localized drug delivery via microbubbles.

  10. Distillation, destructive

    Energy Technology Data Exchange (ETDEWEB)

    Young, W; Neilson, A; Young, A

    1876-10-09

    The invention relates to modifications of the retort apparatus, described in Specification No. 2487, A.D. 1872, for the destructive distillation of shale and other bituminous substances. The retorts instead of being worked continuously are completely filled and completely discharged in turn. They are made oblong in cross-section in order to present the material in thin layers and cause it to be acted upon more rapidly and economically. The retorts can thus be heated solely by the combustion of the carbonaceus matter contained in the discharged residues or with a small amount of coal in addition. Each retort is contracted at the bottom and is fitted with a box or chest having a hole in it corresponding to the opening in the retort and a sliding plate of iron, firebrick, or other suitable material, which can be operated by a rod passing through the front of the box, for opening or closing the retort. Underneath the box and over the combustion chamber are placed fireclay blocks leaving an opening, which can be closed by another plate of firebrick or the like. When distillation commences, the gases and vapors in the retort are drawn off through a pipe and a main by an exhauster. In order to prevent air from entering the retort or hydrocarbon vapor from being puffed back by the action of the wind, the gas which remains after the condensation of the oils is forced back into the box between the plates and part of it enters the retort and part the combustion chamber. In order to avoid the liability of the oil being carried past the condensers by the action of the gas, steam may be used as a substitute for the gas or mixed with it in large proportions, a steam jet being used to force the gas into the main supplying the boxes.

  11. Improvement of ore recovery efficiency in a flotation column cell using ultra-sonic enhanced bubbles

    Science.gov (United States)

    Filippov, L. O.; Royer, J. J.; Filippova, I. V.

    2017-07-01

    The ore process flotation technique is enhanced by using external ultra-sonic waves. Compared to the classical flotation method, the application of ultrasounds to flotation fluids generates micro-bubbles by hydrodynamic cavitation. Flotation performances increase was modelled as a result of increased probabilities of the particle-bubble attachment and reduced detachment probability under sonication. A simplified analytical Navier-Stokes model is used to predict the effect of ultrasonic waves on bubble behavior. If the theory is verified by experimentation, it predicts that the ultrasonic waves would create cavitation micro-bubbles, smaller than the flotation bubble added by the gas sparger. This effect leads to increasing the number of small bubbles in the liquid which promote particle-bubble attachment through coalescence between bubbles and micro-bubbles. The decrease in the radius of the flotation bubbles under external vibration forces has an additional effect by enhancing the bubble-particle collision. Preliminary results performed on a potash ore seem to confirm the theory.

  12. Ultrasonic treatment for microbiological control of water systems

    International Nuclear Information System (INIS)

    Broekman, S.; Pohlmann, O.; Beardwooden, E. S.; Cordemans de Meulenaer, E.

    2010-01-01

    A combination treatment of shear, micro-bubbles, and high-frequency low-power ultrasound introduced via side-stream treatment of industrial water systems has shown excellent results in controlling bacteria and algae; Through the physical, high-stress environment created by ultrasonic waves, sessile and planktonic biological populations, some of which may undergo programmed cell death (PCD), can be controlled. Additionally, the instability and reduction of biofilm have been observed in systems treated by ultrasound and may be attributed to starvation-stress and lack of available cross-linking cations in the biofilm. (authors)

  13. Ultrasonic treatment for microbiological control of water systems

    Energy Technology Data Exchange (ETDEWEB)

    Broekman, S.; Pohlmann, O.; Beardwooden, E. S.; Cordemans de Meulenaer, E. [Ashland Hercules Water Technologies, Krefeld (Germany)

    2010-08-15

    A combination treatment of shear, micro-bubbles, and high-frequency low-power ultrasound introduced via side-stream treatment of industrial water systems has shown excellent results in controlling bacteria and algae; Through the physical, high-stress environment created by ultrasonic waves, sessile and planktonic biological populations, some of which may undergo programmed cell death (PCD), can be controlled. Additionally, the instability and reduction of biofilm have been observed in systems treated by ultrasound and may be attributed to starvation-stress and lack of available cross-linking cations in the biofilm. (authors)

  14. Non-linear Response and Viscoelastic Properties of Lipid-Coated Microbubbles: DSPC versus DPPC

    NARCIS (Netherlands)

    van Rooij, T.; Luan, Y.; Renaud, G.; van der Steen, A.F.W.; Versluis, Michel; de Jong, N.; Kooiman, K.

    2015-01-01

    For successful in vivo contrast-enhanced ultrasound imaging (CEUS) and ultrasound molecular imaging, detailed knowledge of stability and acoustical properties of the microbubbles is essential. Here, we compare these aspects of lipid-coated microbubbles that have either

  15. Microbubble enhanced ozonation process for advanced treatment of wastewater produced in acrylic fiber manufacturing industry

    KAUST Repository

    Zheng, Tianlong; Wang, Qunhui; Zhang, Tao; Shi, Zhining; Tian, Yanli; Shi, Shanshan; Smale, Nicholas; Wang, Juan

    2015-01-01

    zeta potential of the bubbles were also observed in the microbubble ozonation process. The biodegradability of the wastewater was also significantly improved by microbubble-ozonation, which was ascribed to the enhanced degradation of alkanes, aromatic

  16. Design and Control of Functional Microbubbles for Medical Applications of Ultrasound

    Science.gov (United States)

    Takagi, Shu; Osaki, Taichi; Ariyoshi, Takuya; Azuma, Takashi; Ichiyanagi, Mitsuhisa; Kinefuchi, Ikuya

    2015-11-01

    Microbubbles are used as a contrast agent for ultrasound diagnosis. It is also expected to be use for the treatment. One of the possible applications is microbubble DDS. For that purpose, microbubbles need to be well-controlled for the generating process and manipulation. In this talk, for the design and control of the functional microbubbles, an experimental study on generation and surface modification of microbubbles are explained. Using a T-junction type microchannel, small bubbles about 5 μm size are successfully generated. For the surface modification, Biotin-coated microbubbles are tried to adhere the Avidin-coated wall. Furthermore, the manipulation of the microbubbles using ultrasound is also discussed. Plane-wave and focused ultrasound is used to manipulate a microbubble and bubble clusters. The experimental results are shown in the presentation. Supported by JSPS KAKENHI Grant Number 15K13865.

  17. Development of non-destructive testing. Turkey

    International Nuclear Information System (INIS)

    1991-01-01

    A National Scheme for the qualification and certification of Non-Destructive Testing (NDT) personnel in various methods has been established as the first stage of implementation. Systematic training in such methods as radiography (RT), ultrasonics (UT), magnetic particles (MT), liquid penetrant (PT) and eddy currents (ET) at levels I, II and some at III has been initiated and should be continued. Direct link with the industry and continuous effort to extend practical applications is strongly recommended

  18. Lung Surfactant Microbubbles Increase Lipophilic Drug Payload for Ultrasound-Targeted Delivery

    OpenAIRE

    Sirsi, Shashank R.; Fung, Chinpong; Garg, Sumit; Tianning, Mary Y.; Mountford, Paul A.; Borden, Mark A.

    2013-01-01

    The cavitation response of circulating microbubbles to targeted ultrasound can be used for noninvasive, site-specific delivery of shell-loaded materials. One challenge for microbubble-mediated delivery of lipophilic compounds is the limitation of drug loading into the microbubble shell, which is commonly a single phospholipid monolayer. In this study, we investigated the use of natural lung surfactant extract (Survanta?, Abbott Nutrition) as a microbubble shell material in order to improve dr...

  19. A novel technology: microfluidic devices for microbubble ultrasound contrast agent generation.

    Science.gov (United States)

    Lin, Hangyu; Chen, Junfang; Chen, Chuanpin

    2016-09-01

    Microbubbles are used as ultrasound contrast agents, which enhance ultrasound imaging techniques. In addition, microbubbles currently show promise in disease therapeutics. Microfluidic devices have increased the ability to produce microbubbles with precise size, and high monodispersity compared to microbubbles created using traditional methods. This paper will review several variations in microfluidic device structures used to produce microbubbles as ultrasound contrast agents. Microfluidic device structures include T-junction, and axisymmetric and asymmetric flow-focusing. These devices have made it possible to produce microbubbles that can enter the vascular space; these microbubbles must be less than 10 μm in diameter and have high monodispersity. For different demands of microbubbles production rate, asymmetric flow-focusing devices were divided into individual and integrated devices. In addition, asymmetric flow-focusing devices can produce double layer and multilayer microbubbles loaded with drug or biological components. Details on the mechanisms of both bubble formation and device structures are provided. Finally, microfluidically produced microbubble acoustic responses, microbubble stability, and microbubble use in ultrasound imaging are discussed.

  20. Computer simulation of ultrasonic testing for aerospace vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Yamawaki, H [National Institute for Materials Science, 1-2-1, Sengen, 305-0047 Tsukuba (Japan); Moriya, S; Masuoka, T [Japan Aerospace Exploration Agency, 1 Koganesawa, Kimigawa, 981-1525 Kakuda (Japan); Takatsubo, J, E-mail: yamawaki.hisashi@nims.go.jp [Advanced Industrial Science and Technology, AIST Tsukuba Central 2, 1-1-1 Umezono, 305-8568 Tsukuba (Japan)

    2011-01-01

    Non-destructive testing techniques are developed to secure reliability of aerospace vehicles used repetitively. In the case of cracks caused by thermal stress on walls in combustion chambers of liquid-fuel rockets, it is examined by ultrasonic waves visualization technique developed in AIST. The technique is composed with non-contact ultrasonic generation by pulsed-laser scanning, piezoelectric transducer for the ultrasonic detection, and image reconstruction processing. It enables detection of defects by visualization of ultrasonic waves scattered by the defects. In NIMS, the condition of the detection by the visualization is investigated using computer simulation for ultrasonic propagation that has capability of fast 3-D calculation. The simulation technique is based on finite-difference method and two-step elastic wave equations. It is reported about the investigation by the calculation, and shows availability of the simulation for the ultrasonic testing technique of the wall cracks.

  1. High-resolution ultrasonic spectroscopy

    Directory of Open Access Journals (Sweden)

    V. Buckin

    2018-03-01

    Full Text Available High-resolution ultrasonic spectroscopy (HR-US is an analytical technique for direct and non-destructive monitoring of molecular and micro-structural transformations in liquids and semi-solid materials. It is based on precision measurements of ultrasonic velocity and attenuation in analysed samples. The application areas of HR-US in research, product development, and quality and process control include analysis of conformational transitions of polymers, ligand binding, molecular self-assembly and aggregation, crystallisation, gelation, characterisation of phase transitions and phase diagrams, and monitoring of chemical and biochemical reactions. The technique does not require optical markers or optical transparency. The HR-US measurements can be performed in small sample volumes (down to droplet size, over broad temperature range, at ambient and elevated pressures, and in various measuring regimes such as automatic temperature ramps, titrations and measurements in flow.

  2. Advanced non-destructive methods for an efficient service performance

    International Nuclear Information System (INIS)

    Rauschenbach, H.; Clossen-von Lanken Schulz, M.; Oberlin, R.

    2015-01-01

    Due to the power generation industry's desire to decrease outage time and extend inspection intervals for highly stressed turbine parts, advanced and reliable Non-destructive methods were developed by Siemens Non-destructive laboratory. Effective outage performance requires the optimized planning of all outage activities as well as modern Non-destructive examination methods, in order to examine the highly stressed components (turbine rotor, casings, valves, generator rotor) reliably and in short periods of access. This paper describes the experience of Siemens Energy with an ultrasonic Phased Array inspection technique for the inspection of radial entry pinned turbine blade roots. The developed inspection technique allows the ultrasonic inspection of steam turbine blades without blade removal. Furthermore advanced Non-destructive examination methods for joint bolts will be described, which offer a significant reduction of outage duration in comparison to conventional inspection techniques. (authors)

  3. Controlling particle trajectories using oscillating microbubbles

    Science.gov (United States)

    Jalikop, Shreyas; Wang, Cheng; Hilgenfeldt, Sascha

    2010-11-01

    In many applications of microfluidics and biotechnology, such as cytometry and drug delivery, it is vital to manipulate the trajectories of microparticles such as vesicles or cells. On this small scale, inertial or gravitational effects are often too weak to exploit. We propose a mechanism to selectively trap and direct particles based on their size in creeping transport flows (Re1). We employ Rayleigh-Nyborg-Westervelt (RNW) streaming generated by an oscillating microbubble, which in turn generates a streaming flow component around the mobile particles. The result is an attractive interaction that draws the particle closer to the bubble. The impenetrability of the bubble interface destroys time-reversal symmetry and forces the particles onto either narrow trajectory bundles or well-defined closed trajectories, where they are trapped. The effect is dependent on particle size and thus allows for the passive focusing and sorting of selected sizes, on scales much smaller than the geometry of the microfluidic device. The device could eliminate the need for complicated microchannel designs with external magnetic or electric fields in applications such as particle focusing and size-based sorting.

  4. Manipulation of Microbubble Clusters Using Focused Ultrasound

    Science.gov (United States)

    Matsuzaki, Hironobu; Osaki, Taichi; Kawaguchi, Kei; Unga, Johan; Ichiyanagi, Mitsuhisa; Azuma, Takashi; Suzuki, Ryo; Maruyama, Kazuo; Takagi, Shu

    2017-11-01

    In recent years, microbubbles (MBs) are expected to be utilized for the ultrasound drug delivery system (DDS). For the MB-DDS, it is important to establish a method of controlling bubbles and bubble clusters using ultrasound field. The objective of this study is to clarify behaviors of bubble clusters with various physical conditions. MBs in the ultrasound field are subjected to the primary Bjerknes force. The force traps MBs at the focal region of the focused ultrasound field. The trapped MBs form a bubble cluster at the region. A bubble cluster continues growing with absorbing surrounding bubbles until it reaches a maximum size beyond which it disappears from the focal region. In the present study, two kinds of MBs are used for the experiment. One is Sonazoid with average diameter of 2.6 um and resonant frequency of 5 MHz. The other is developed by Teikyo Univ., with average diameter of 1.5 um and presumed resonant frequency of 4 MHz. The bubble cluster's behaviors are analyzed using the high-speed camera. Sonazoid clusters have larger critical size than the other in every frequency, and its cluster size is inversely proportional to the ultrasound frequency, while Teikyo-bubble clusters have different tendency. These results are discussed in the presentation.

  5. Robust microbubble tracking for super resolution imaging in ultrasound

    DEFF Research Database (Denmark)

    Hansen, Kristoffer B.; Villagómez Hoyos, Carlos Armando; Brasen, Jens Christian

    2016-01-01

    Currently ultrasound resolution is limited by diffraction to approximately half the wavelength of the sound wave employed. In recent years, super resolution imaging techniques have overcome the diffraction limit through the localization and tracking of a sparse set of microbubbles through...... the vasculature. However, this has only been performed on fixated tissue, limiting its clinical application. This paper proposes a technique for making super resolution images on non-fixated tissue by first compensating for tissue movement and then tracking the individual microbubbles. The experiment is performed...... on the kidney of a anesthetized Sprage-Dawley rat by infusing SonoVue at 0.1× original concentration. The algorithm demonstrated in vivo that the motion compensation was capable of removing the movement caused by the mechanical ventilator. The results shows that microbubbles were localized with a higher...

  6. Superparamagnetic nanoparticle-inclusion microbubbles for ultrasound contrast agents

    International Nuclear Information System (INIS)

    Yang Fang; Li Yixin; Chen Zhongping; Gu Ning; Li Ling; Wu Junru

    2008-01-01

    We have developed a new type of ultrasound (US) contrast agent, consisting of a gas core, a layer of superparamagnetic iron oxide Fe 3 O 4 nanoparticles (SPIO) and an oil in water outermost layer. The newly developed US contrast agent microbubbles have a mean diameter of 760 nm with a polydisperity index (PI) of 0.699. Our in vitro and in vivo experiments have shown that they have the following advantages compared to gas-encapsulated microbbubbles without SPIO inclusion: (1) they provide better contrast for US images; (2) the SPIO-inclusion microbubbles generate a higher backscattering signal; the mean grey scale is 97.9, which is 38.6 higher than that of microbubbles without SPIO; and (3) since SPIO can also serve as a contrast agent of magnetic resonance images (MRI) in vitro, they can be potentially used as contrast agents for double-modality (MRI and US) clinical studies.

  7. Modeling Encapsulated Microbubble Dynamics at High Pressure Amplitudes

    Science.gov (United States)

    Heyse, Jan F.; Bose, Sanjeeb; Iaccarino, Gianluca

    2017-11-01

    Encapsulated microbubbles are commonly used in ultrasound contrast imaging and are of growing interest in therapeutic applications where local cavitation creates temporary perforations in cell membranes allowing for enhanced drug delivery. Clinically used microbubbles are encapsulated by a shell commonly consisting of protein, polymer, or phospholipid; the response of these bubbles to externally imposed ultrasound waves is sensitive to the compressibility of the encapsulating shell. Existing models approximate the shell compressibility via an effective surface tension (Marmottant et al. 2005). We present simulations of microbubbles subjected to high amplitude ultrasound waves (on the order of 106 Pa) and compare the results with the experimental measurements of Helfield et al. (2016). Analysis of critical points (corresponding to maximum and minimum expansion) in the governing Rayleigh-Plesset equation is used to make estimates of the parameters used to characterize the effective surface tension of the encapsulating shell. Stanford Graduate Fellowship.

  8. Ultrasound imaging of the mouse pancreatic duct using lipid microbubbles

    Science.gov (United States)

    Banerjee, B.; McKeown, K. R.; Skovan, B.; Ogram, E.; Ingram, P.; Ignatenko, N.; Paine-Murrieta, G.; Witte, R.; Matsunaga, T. O.

    2012-03-01

    Research requiring the murine pancreatic duct to be imaged is often challenging due to the difficulty in selectively cannulating the pancreatic duct. We have successfully catheterized the pancreatic duct through the common bile duct in severe combined immune deficient (SCID) mice and imaged the pancreatic duct with gas filled lipid microbubbles that increase ultrasound imaging sensitivity due to exquisite scattering at the gas/liquid interface. A SCID mouse was euthanized by CO2, a midline abdominal incision made, the common bile duct cut at its midpoint, a 2 cm, 32 gauge tip catheter was inserted about 1 mm into the duct and tied with suture. The duodenum and pancreas were excised, removed in toto, embedded in agar and an infusion pump was used to instill normal saline or lipid-coated microbubbles (10 million / ml) into the duct. B-mode images before and after infusion of the duct with microbubbles imaged the entire pancreatic duct (~ 1 cm) with high contrast. The microbubbles were cavitated by high mechanical index (HMI) ultrasound for imaging to be repeated. Our technique of catheterization and using lipid microbubbles as a contrast agent may provide an effective, affordable technique of imaging the murine pancreatic duct; cavitation with HMI ultrasound would enable repeated imaging to be performed and clustering of targeted microbubbles to receptors on ductal cells would allow pathology to be localized accurately. This research was supported by the Experimental Mouse Shared Service of the AZ Cancer Center (Grant Number P30CA023074, NIH/NCI and the GI SPORE (NIH/NCI P50 CA95060).

  9. Effect of microbubble ligation to cells on ultrasound signal enhancement: implications for targeted imaging.

    Science.gov (United States)

    Lankford, Miles; Behm, Carolyn Z; Yeh, James; Klibanov, Alexander L; Robinson, Peter; Lindner, Jonathan R

    2006-10-01

    Molecular imaging with contrast-enhanced ultrasound (CEU) relies on the detection of microbubbles retained in regions of disease. The aim of this study was to determine whether microbubble attachment to cells influences their acoustic signal generation and stability. Biotinylated microbubbles were attached to streptavidin-coated plates to derive density versus intensity relations during low- and high-power imaging. To assess damping from microbubble attachment to solid or cell surfaces, in vitro imaging was performed for microbubbles charge-coupled to methacrylate spheres and for vascular cell adhesion molecule-1-targeted microbubbles attached to endothelial cells. Signal enhancement on plates increased according to acoustic power and microbubble site density up to 300 mm. Microbubble signal was reduced by attachment to solid spheres during high- and low-power imaging but was minimally reduced by attachment to endothelial cells and only at low power. Attachment of targeted microbubbles to rigid surfaces results in damping and a reduction of their acoustic signal, which is not seen when microbubbles are attached to cells. A reliable concentration versus intensity relationship can be expected from microbubble attachment to 2-dimensional surfaces until a very high site density is reached.

  10. Simulation of microbubble response to ambient pressure changes

    DEFF Research Database (Denmark)

    Andersen, Klaus Scheldrup; Jensen, Jørgen Arendt

    2008-01-01

    The theory on microbubbles clearly indicates a relation between the ambient pressure and the acoustic behavior of the bubble. The purpose of this study was to optimize the sensitivity of ambient pressure measurements, using the subharmonic component, through microbubble response simulations....... The behaviour of two different contrast agents was investigated as a function of driving pulse and ambient overpressure, pov. Simulations of Levovist using a rectangular driving pulse show an almost linear reduction in the subharmonic component as pov is increased. For a 20 cycles driving pulse, a reduction...... is not completely linear as a function of the ambient pressure....

  11. Radiation-Force Assisted Targeting Facilitates Ultrasonic Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Shukui Zhao

    2004-07-01

    Full Text Available Ultrasonic molecular imaging employs contrast agents, such as microbubbles, nanoparticles, or liposomes, coated with ligands specific for receptors expressed on cells at sites of angiogenesis, inflammation, or thrombus. Concentration of these highly echogenic contrast agents at a target site enhances the ultrasound signal received from that site, promoting ultrasonic detection and analysis of disease states. In this article, we show that acoustic radiation force can be used to displace targeted contrast agents to a vessel wall, greatly increasing the number of agents binding to available surface receptors. We provide a theoretical evaluation of the magnitude of acoustic radiation force and show that it is possible to displace micron-sized agents physiologically relevant distances. Following this, we show in a series of experiments that acoustic radiation force can enhance the binding of targeted agents: The number of biotinylated microbubbles adherent to a synthetic vessel coated with avidin increases as much as 20-fold when acoustic radiation force is applied; the adhesion of contrast agents targeted to αvβ3 expressed on human umbilical vein endothelial cells increases 27-fold within a mimetic vessel when radiation force is applied; and finally, the image signal-to-noise ratio in a phantom vessel increases up to 25 dB using a combination of radiation force and a targeted contrast agent, over use of a targeted contrast agent alone.

  12. Ultrasonic process for detoxification of groundwater

    International Nuclear Information System (INIS)

    Wu, Jiann M.; Huang, H.S.; Livengood, C.D.

    1991-01-01

    In this paper, we present the results of an investigation of the ultrasonic irradiation of carbon tetrachloride at various pH values, temperatures, and power intensities. Kinetic data and selected chemical mechanism are discussed and proposed. To study oxidant efficiency, chemical oxidants, such as hydrogen peroxide, are also considered. This work is part of a project entitled ''Ultrasonic Process for Detoxification of Groundwater and Soil,'' sponsored by the US Department of Energy, Office of Technology Development, to develop an innovative process for the effective destruction of chlorinated organics in soil and groundwater

  13. Ultrasonic hydrometer

    Science.gov (United States)

    Swoboda, Carl A.

    1984-01-01

    The disclosed ultrasonic hydrometer determines the specific gravity (density) of the electrolyte of a wet battery, such as a lead-acid battery. The hydrometer utilizes a transducer that when excited emits an ultrasonic impulse that traverses through the electrolyte back and forth between spaced sonic surfaces. The transducer detects the returning impulse, and means measures the time "t" between the initial and returning impulses. Considering the distance "d" between the spaced sonic surfaces and the measured time "t", the sonic velocity "V" is calculated with the equation "V=2d/t". The hydrometer also utilizes a thermocouple to measure the electrolyte temperature. A hydrometer database correlates three variable parameters including sonic velocity in and temperature and specific gravity of the electrolyte, for temperature values between 0.degree. and 40.degree. C. and for specific gravity values between 1.05 and 1.30. Upon knowing two parameters (the calculated sonic velocity and the measured temperature), the third parameter (specific gravity) can be uniquely found in the database. The hydrometer utilizes a microprocessor for data storage and manipulation. The disclosed modified battery has a hollow spacer nub on the battery side wall, the sonic surfaces being on the inside of the nub and the electrolyte filling between the surfaces to the exclusion of intervening structure. An accessible pad exposed on the nub wall opposite one sonic surface allows the reliable placement thereagainst of the transducer.

  14. Non-destructive controls in the steel tube industry

    International Nuclear Information System (INIS)

    Mondot, J.

    1978-01-01

    The main non-destructive control methods in the tube industry are reviewed: eddy currents, particularly well adapted to small tubes; magnetoscopic testing for weldless tubes; ultrasonic waves widely used for thick weldless tubes and weldings; radiography, to examine tube ends and the known questionable zones; measure of diameters by laser [fr

  15. NonDestructive Evaluation for Industrial & Development Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, James F. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-10-12

    Provide overview of weld inspection for Non-Destructive Testing at LANL. This includes radiography (RT/DR/CR/CT for x-ray & neutron sources), ultrasonic testing (UT/PAUT), dye penetrant inspection (PT), eddy current inspection (ET) and magnetic particle testing (MT). Facilities and capabilities for weld inspection will be summarized with examples.

  16. Non-destructive controls in the mechanical industry

    Energy Technology Data Exchange (ETDEWEB)

    Jarlan, L

    1978-12-01

    The sequence of operations implicating the mechanical industries from the suppliers to their customers is briefly recalled; a description of the field of application of non-destructive control methods in these industries is given. Follows a description of some recent typical applications of the principal methods: radiography, ultrasonic waves, magnetism, acoustic emission, sonic control, tracer techniques.

  17. Ultrasonic imaging in concrete

    International Nuclear Information System (INIS)

    Ribay, G.; Paris, O.; Rambach, J.M.

    2009-01-01

    The third and final protection barrier confining nuclear reactors is usually a concrete containment structure. Monitoring the structural integrity of these barriers is critical in ensuring the safety of nuclear power plants. The Institute for Radiological Protection and Nuclear Safety (IRSN) in France in collaboration with the French Atomic commission (CEA/LIST) has developed an ultrasonic phased-array technique capable of inspecting thick concrete walls. The non-destructive method is dedicated to detect cracks and bulk defects. Given the thickness of the structure (1.2 m) undergoing inspection and the heterogeneity of the concrete, the optimal frequency lies in the 50-300 kHz range. At these frequencies, the ultrasonic beam profiles are widespread (non-directive) with poor signal-to-noise ratio. Previous studies have shown the potential of using phased-array techniques (i.e., beam focusing and beam steering) in order to improve detection resolution and sizing accuracy. In this paper we present experimental studies performed with array up to 16 transducers working at 200 kHz. Experiments are carried out on representative concrete blocks containing artificial defects. One is a reinforced mock-up representative of the first reinforcing mesh of wall containment. Experimental results show that in spite of the reinforcement, artificial defects deep as half a meter can be detected. Reconstructed images resulting from phased array acquisitions on an artificial crack embedded in a concrete block are also presented and discussed. The presented method allows detecting oriented defects in concrete with improved signal to noise ratio and sensibility. A simulation model of the interaction of ultrasound with a heterogeneous medium like concrete is briefly commented. (authors)

  18. Biological in situ characterization of polymeric microbubble contrast agents

    NARCIS (Netherlands)

    Wan, Sha; Egri, Gabriella; Oddo, Letizia; Cerroni, Barbara; Dähne, Lars; Paradossi, Gaio; Salvati, Anna; Lynch, Iseult; Dawson, Kenneth A; Monopoli, Marco P

    Polymeric microbubbles (MBs) are gas filled particles composed of a thin stabilized polymer shell that have been recently developed as valid contrast agents for the combined use of ultrasonography (US), magnetic resonance imaging (MRI) and single photon emission computer tomography (SPECT) imaging.

  19. Lung surfactant microbubbles increase lipophilic drug payload for ultrasound-targeted delivery.

    Science.gov (United States)

    Sirsi, Shashank R; Fung, Chinpong; Garg, Sumit; Tianning, Mary Y; Mountford, Paul A; Borden, Mark A

    2013-01-01

    The cavitation response of circulating microbubbles to targeted ultrasound can be used for noninvasive, site-specific delivery of shell-loaded materials. One challenge for microbubble-mediated delivery of lipophilic compounds is the limitation of drug loading into the microbubble shell, which is commonly a single phospholipid monolayer. In this study, we investigated the use of natural lung surfactant extract (Survanta(®), Abbott Nutrition) as a microbubble shell material in order to improve drug payload and delivery. Pulmonary surfactant extracts such as Survanta contain hydrophobic surfactant proteins (SP-B and SP-C) that facilitate lipid folding and retention on lipid monolayers. Here, we show that Survanta-based microbubbles exhibit wrinkles in bright-field microscopy and increased lipid retention on the microbubble surface in the form of surface-associated aggregates observed with fluorescence microscopy. The payload of a model lipophilic drug (DiO), measured by flow cytometry, increased by over 2-fold compared to lipid-coated microbubbles lacking SP-B and SP-C. Lung surfactant microbubbles were highly echogenic to contrast enhanced ultrasound imaging at low acoustic intensities. At higher ultrasound intensity, excess lipid was observed to be acoustically cleaved for localized release. To demonstrate targeting, a biotinylated lipopolymer was incorporated into the shell, and the microbubbles were subjected to a sequence of radiation force and fragmentation pulses as they passed through an avidinated hollow fiber. Lung surfactant microbubbles showed a 3-fold increase in targeted deposition of the model fluorescent drug compared to lipid-only microbubbles. Our results demonstrate that lung surfactant microbubbles maintain the acoustic responsiveness of lipid-coated microbubbles with the added benefit of increased lipophilic drug payload.

  20. Development of microbubble contrast agents for high frequency ultrasound microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jun, Se Jung; Kim, Eun A; Park, Sung Hoon; Lee, Hye Jin; Jun, Hong Young; Byun, Seung Jae; Yoon, Kwon Ha [Wonkwang University School of Medicine, Iksan (Korea, Republic of)

    2007-05-15

    To develop optimal microbubble contrast agents (MBCAs) for performing ultrasound microscopy when examining small animals. We prepared three types of MBCAs. First, a mixture of three parts of 40% dextran and one part of 5% human serum albumin were sonicated with perfluorocarbon (PFC) (MB{sub 1}-D40A5P). Second, three parts of 40% dextran and one part of 1% human serum albumin were sonicated with PFC (MB{sub 2}-D40A1P). Third, all parts of 1% bovine serum albumin were sonicated with PFC (MB{sub 3}-A1P). We measured the microbubbles' sizes and concentrations with using image analysis software. The acoustic properties of the microbubbles were assessed both in vitro and in vivo. The majority of the MB{sub 1}-D40A5Ps had a diameter of 2-5 {mu} m, the mean diameter of the MB{sub 2}-D40A1Ps was 2.5 {mu} m, and the mean diameter of the MB{sub 3}-A1Ps was less than 2.0 {mu} m. Among the microbubbles, the MB{sub 1}-D40A5Ps and MB{sub 2}-D40A1Ps showed increased echogenicity in the abdominal vessels, but the duration of their contrast effect was less than 30 sec. On the contrary, the MB3-A1Ps exhibited strong enhancement in the vessels and their duration was greater than 120 sec. A microbubble contrast agent consisting of all parts of 1% serum albumin sonicated with PFC is an effective contrast agent for ultrasound microscopy.

  1. Introduction to non-destructive testing of materials: part II

    International Nuclear Information System (INIS)

    Ahmed, M.; Ahmed, B.

    2001-01-01

    Ultrasonic waves are mechanical vibrations that require a medium, which functions as carrier. Ultrasonics are widely used in non-destructive testing of materials in which high frequency sound waves are introduced into the material being inspected. If the frequency of sound waves in within the range 10 to 20,000 Hz, the sound is audible, i.e. the range of hearing, above 20,000 Hz, the sound waves are referred to as Ultrasound or Ultrasonics. Sound waves do not cause any permanent change in material although its transient presence is very noticeable. An energy transport through a sound wave is possible only when constituent particles are connected to each other by elastic forces. Liquids and Gases are also suitable media for the transmission of sound. In vacuum no matter exists and thus no sound transmission is possible. At the end of this article advantages and limitations of ultrasonic testing are also given. (A.B.)

  2. Signal analysis approach to ultrasonic evaluation of diffusion bond quality

    International Nuclear Information System (INIS)

    Thomas, Graham; Chinn, Diane

    1999-01-01

    Solid state bonds like the diffusion bond are attractive techniques for joining dissimilar materials since they are not prone to the defects that occur with fusion welding. Ultrasonic methods can detect the presence of totally unbonded regions but have difficulty sensing poor bonded areas where the substrates are in intimate contact. Standard ultrasonic imaging is based on amplitude changes in the signal reflected from the bond interface. Unfortunately, amplitude alone is not sensitive to bond quality. We demonstrated that there is additional information in the ultrasonic signal that correlates with bond quality. In our approach, we interrogated a set of dissimilar diffusion bonded samples with broad band ultrasonic signals. The signals were digitally processed and the characteristics of the signals that corresponded to bond quality were determined. These characteristics or features were processed with pattern recognition algorithms to produce predictions of bond quality. The predicted bond quality was then compared with the destructive measurement to assess the classification capability of the ultrasonic technique

  3. Ultrasonic evaluation of local human skin anisotropy

    Czech Academy of Sciences Publication Activity Database

    Tokar, Daniel; Převorovský, Zdeněk; Hradilová, Jana

    2014-01-01

    Roč. 19, č. 12 (2014) ISSN 1435-4934. [European Conference on Non-Destructive Testing (ECNDT 2014) /11./. Praha, 06.10.2014-10.10.2014] Institutional support: RVO:61388998 Keywords : anisotropy * ultrasonic testing * human skin in-vivo * fabric-fiber composite * signal processing Subject RIV: BI - Acoustics http://www.ndt.net/events/ECNDT2014/app/content/Paper/324_Tokar.pdf

  4. Ultrasonication and food technology: A review

    OpenAIRE

    Ishrat Majid; Gulzar Ahmad Nayik; Vikas Nanda

    2015-01-01

    With increasing consumers demand and tightening of food and environmental regulations, traditional food-processing techniques have lost their optimum performance which gave rise to new and powerful technologies. Ultrasonic is a one of the fast, versatile, emerging, and promising non-destructive green technology used in the food industry from last few years. The ultrasound is being carried out in various areas of food technology namely crystallization, freezing, bleaching, degassing, extractio...

  5. Sampling phased array a new technique for signal processing and ultrasonic imaging

    OpenAIRE

    Bulavinov, A.; Joneit, D.; Kröning, M.; Bernus, L.; Dalichow, M.H.; Reddy, K.M.

    2006-01-01

    Different signal processing and image reconstruction techniques are applied in ultrasonic non-destructive material evaluation. In recent years, rapid development in the fields of microelectronics and computer engineering lead to wide application of phased array systems. A new phased array technique, called "Sampling Phased Array" has been developed in Fraunhofer Institute for non-destructive testing. It realizes unique approach of measurement and processing of ultrasonic signals. The sampling...

  6. Sampling phased array - a new technique for ultrasonic signal processing and imaging

    OpenAIRE

    Verkooijen, J.; Boulavinov, A.

    2008-01-01

    Over the past 10 years, the improvement in the field of microelectronics and computer engineering has led to significant advances in ultrasonic signal processing and image construction techniques that are currently being applied to non-destructive material evaluation. A new phased array technique, called 'Sampling Phased Array', has been developed in the Fraunhofer Institute for Non-Destructive Testing([1]). It realises a unique approach of measurement and processing of ultrasonic signals. Th...

  7. Sampling phased array, a new technique for ultrasonic signal processing and imaging now available to industry

    OpenAIRE

    Verkooijen, J.; Bulavinov, A.

    2008-01-01

    Over the past 10 years the improvement in the field of microelectronics and computer engineering has led to significant advances in ultrasonic signal processing and image construction techniques that are currently being applied to non-destructive material evaluation. A new phased array technique, called "Sampling Phased Array" has been developed in the Fraunhofer Institute for non-destructive testing [1]. It realizes a unique approach of measurement and processing of ultrasonic signals. The s...

  8. PIV measurement of a contraction flow using micro-bubble tracer

    International Nuclear Information System (INIS)

    Ishikawa, Masaaki; Irabu, Kunio; Teruya, Isao; Nitta, Munehiro

    2009-01-01

    Recently, a technique using the micro-bubbles is focused. It was applied to many fields such as purification of rivers and lakes, washing the industrial parts, growth of plants and marine products. The characteristics of micro-bubbles are small size, wide surface area, low terminal velocity, and so on. If this micro-bubble is available as tracer of PIV (Particle Image Velocimetry), environment load would become lower because it doesn't need to discard particle. In this paper, we make a micro-bubble generator with Venturi type mechanism. The generated micro-bubbles are applied to a vertical channel flow with contraction. We validate about traceability of the micro-bubble tracer in comparison with the particle tracer.

  9. Aptamer-crosslinked microbubbles: smart contrast agents for thrombin-activated ultrasound imaging.

    Science.gov (United States)

    Nakatsuka, Matthew A; Mattrey, Robert F; Esener, Sadik C; Cha, Jennifer N; Goodwin, Andrew P

    2012-11-27

    Thrombosis, or malignant blood clotting, is associated with numerous cardiovascular diseases and cancers. A microbubble contrast agent is presented that produces ultrasound harmonic signal only when exposed to elevated thrombin levels. Initially silent microbubbles are activated in the presence of both thrombin-spiked and freshly clotting blood in three minutes with detection limits of 20 nM thrombin and 2 aM microbubbles. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Ultrasound in Biomedical Engineering: Ultrasound Microbubble Contrast Agents Promote Transdermal Permeation of Drugs

    OpenAIRE

    Ai-Ho Liao

    2016-01-01

    This report discusses a new development in the use of ultrasound microbubble contrast agents on transdermal drug delivery. The medium surrounding the microbubbles at the optimum concentration from liquid to gel can be modified and it can still achieve the same enhancement for transdermal drug permeation as liquid medium. It was also found that under the same ultrasound power density, microbubbles of larger particle sizes can extend the penetration depths of dye at the phantom surface.

  11. Phase contrast imaging of preclinical portal vein embolization with CO2 microbubbles.

    Science.gov (United States)

    Tang, Rongbiao; Yan, Fuhua; Yang, Guo Yuan; Chen, Ke Min

    2017-11-01

    Preoperative portal vein embolization (PVE) is employed clinically to avoid postoperative liver insufficiency. Animal models are usually used to study PVE in terms of mechanisms and pathophysiological changes. PVE is formerly monitored by conventional absorption contrast imaging (ACI) with iodine contrast agent. However, the side effects induced by iodine can give rise to animal damage and death. In this study, the feasibility of using phase contrast imaging (PCI) to show PVE using homemade CO 2 microbubbles in living rats has been investigated. CO 2 gas was first formed from the reaction between citric acid and sodium bicarbonate. The CO 2 gas was then encapsulated by egg white to fabricate CO 2 microbubbles. ACI and PCI of CO 2 microbubbles were performed and compared in vitro. An additional increase in contrast was detected in PCI. PCI showed that CO 2 microbubbles gradually dissolved over time, and the remaining CO 2 microbubbles became larger. By PCI, the CO 2 microbubbles were found to have certain stability, suggesting their potential use as embolic agents. CO 2 microbubbles were injected into the main portal trunk to perform PVE in living rats. PCI exploited the differences in the refractive index and facilitated clear visualization of the PVE after the injection of CO 2 microbubbles. Findings from this study suggest that homemade CO 2 microbubbles-based PCI is a novel modality for preclinical PVE research.

  12. Rest-Stress Limb Perfusion Imaging in Humans with Contrast Ultrasound Using Intermediate-Power Imaging and Microbubbles Resistant to Inertial Cavitation.

    Science.gov (United States)

    Davidson, Brian P; Hodovan, James; Belcik, J Todd; Moccetti, Federico; Xie, Aris; Ammi, Azzdine Y; Lindner, Jonathan R

    2017-05-01

    Contrast-enhanced ultrasound (CEU) limb perfusion imaging is a promising approach for evaluating peripheral artery disease (PAD). However, low signal enhancement in skeletal muscle has necessitated high-power intermittent imaging algorithms, which are not clinically feasible. We hypothesized that CEU using a combination of intermediate power and a contrast agent resistant to inertial cavitation would allow real-time limb stress perfusion imaging. In normal volunteers, CEU of the calf skeletal muscle was performed on separate days with Sonazoid, Optison, or Definity. Progressive reduction in the ultrasound pulsing interval was used to assess the balance between signal enhancement and agent destruction at escalating mechanical indices (MI, 0.1-0.4). Real-time perfusion imaging at MI 0.1-0.4 using postdestructive replenishment kinetics was performed at rest and during 25 W plantar flexion contractile exercise. For Optison, limb perfusion imaging was unreliable at rest due to very low signal enhancement generated at all MIs and was possible during exercise-induced hyperemia only at MI 0.1 due to agent destruction at higher MIs. For Definity, signal intensity progressively increased with MI but was offset by microbubble destruction, which resulted in modest signal enhancement during CEU perfusion imaging and distortion of replenishment curves at MI ≥ 0.2. For Sonazoid, there strong signal enhancement at MI ≥ 0.2, with little destruction detected only at MI 0.4. Accordingly, high signal intensity and nondistorted perfusion imaging was possible at MI 0.2-0.3 and detected an 8.0- ± 5.7-fold flow reserve. Rest-stress limb perfusion imaging in humans with real-time CEU, which requires only seconds to perform, is possible using microbubbles with viscoelastic properties that produce strong nonlinear signal generation without destruction at intermediate acoustic pressures. Copyright © 2016 American Society of Echocardiography. All rights reserved.

  13. Economic importance of non-destructive testing

    International Nuclear Information System (INIS)

    Loebert, P.

    1979-01-01

    On May 21 to 23, 1979, the annual meeting of the Deutsche Gesellschaft fuer Zerstoerungsfreie Pruefung took place in Lindau near the Bodensee lake. About 600 experts from Germany and abroad participated in the meeting, whose general subject was 'The Economic Importance of Non-Destructive Testing'. Theoretical problems and practical investigations were discussed in a number of papers on special subjects. Apart from the 33 papers, there was also a poster show with 53 stands with texts, drawings, diagrams, and figures where the authors informed those interested on the latest state of knowledge in testing. The short papers were read in six sessions under the headings of rentability of non-destructive testing, X-ray methods, electromagnetic methods, and ultrasonic methods 1 and 2. (orig.) [de

  14. Coupled dynamics of translation and collapse of acoustically driven microbubbles.

    Science.gov (United States)

    Reddy, Anil J; Szeri, Andrew J

    2002-10-01

    Pressure gradients drive the motion of microbubbles relative to liquids in which they are suspended. Examples include the hydrostatic pressure due to a gravitational field, and the pressure gradients in a sound field, useful for acoustic levitation. In this paper, the equations describing the coupled dynamics of radial oscillation and translation of a microbubble are given. The formulation is based on a recently derived expression for the hydrodynamic force on a bubble of changing size in an incompressible liquid [J. Magnaudet and D. Legendre, Phys. Fluids 10, 550-556 (1998)]. The complex interaction between radial and translation dynamics is best understood by examination of the added momentum associated with the liquid motion caused by the moving bubble. Translation is maximized when the bubble collapses violently. The new theory for coupled collapse and translation dynamics is compared to past experiments and to previous theories for decoupled translation dynamics. Special attention is paid to bubbles of relevance in biomedical applications.

  15. A co-flow-focusing monodisperse microbubble generator

    KAUST Repository

    Zhang, Jiaming; Li, Erqiang; Thoroddsen, Sigurdur T

    2014-01-01

    We use a simple and inexpensive microfluidic device, which is based on microscope glass slides and two tapered glass capillaries, to produce monodisperse microbubbles. The innermost capillary used for transporting the gas is inserted into the second capillary, with its 2 μm sharp tip aligned with the center of the converging-diverging throat of the second capillary. This configuration provides a small and smooth gas flow rate, and a high velocity gradient at the tube outlet. Highly monodisperse microbubbles with diameters ranging from 3.5 to 60 microns have been successfully produced at a rate of up to 40 kHz. A simple scaling law, which is based on the capillary number and liquid-to-gas flow rate ratio, successfully predicts the bubble size. © 2014 IOP Publishing Ltd.

  16. A co-flow-focusing monodisperse microbubble generator

    KAUST Repository

    Zhang, Jiaming

    2014-02-14

    We use a simple and inexpensive microfluidic device, which is based on microscope glass slides and two tapered glass capillaries, to produce monodisperse microbubbles. The innermost capillary used for transporting the gas is inserted into the second capillary, with its 2 μm sharp tip aligned with the center of the converging-diverging throat of the second capillary. This configuration provides a small and smooth gas flow rate, and a high velocity gradient at the tube outlet. Highly monodisperse microbubbles with diameters ranging from 3.5 to 60 microns have been successfully produced at a rate of up to 40 kHz. A simple scaling law, which is based on the capillary number and liquid-to-gas flow rate ratio, successfully predicts the bubble size. © 2014 IOP Publishing Ltd.

  17. Microbubbles as drug delivery systems in cerebrovascular diseases.

    Science.gov (United States)

    Spinelli, Mariacarmela; Demitri, Christian; Sannino, Alessandro; Peruzzotti-Jametti, Luca; Bacigaluppi, Marco; Comi, Giancarlo; Corea, Francesco

    2009-11-01

    The field of neurovascular ultrasound is growing rapidly with new applications. While ultrasound contrast agents were initially used to overcome poor transcranial bone windows for identification of cerebral arteries, newgeneration microbubbles in combination with innovative contrast-specific ultrasound techniques now enable potential therapeutic procedures. This article will provide a review of recent and emerging developments along with patents in ultrasound technology and contrast-specific therapeutic techniques for cerebrovascular patients.

  18. Microbubble generator excited by fluidic oscillator's third harmonic frequency

    Czech Academy of Sciences Publication Activity Database

    Tesař, Václav

    2014-01-01

    Roč. 92, č. 9 (2014), s. 1603-1615 ISSN 0263-8762 R&D Projects: GA ČR GA13-23046S Institutional support: RVO:61388998 Keywords : fluidic oscillator * microbubble generation * fluidic feedback loop Subject RIV: BK - Fluid Dynamics Impact factor: 2.348, year: 2014 http://dx.doi.org/10.1016/j.cherd.2013.12.004

  19. Microbubbles-Assisted Ultrasound Triggers the Release of Extracellular Vesicles

    Directory of Open Access Journals (Sweden)

    Yuana Yuana

    2017-07-01

    Full Text Available Microbubbles-assisted ultrasound (USMB has shown promise in improving local drug delivery. The formation of transient membrane pores and endocytosis are reported to be enhanced by USMB, and they contribute to cellular drug uptake. Exocytosis also seems to be linked to endocytosis upon USMB treatment. Based on this rationale, we investigated whether USMB triggers exocytosis resulting in the release of extracellular vesicles (EVs. USMB was performed on a monolayer of head-and-neck cancer cells (FaDu with clinically approved microbubbles and commonly used ultrasound parameters. At 2, 4, and 24 h, cells and EV-containing conditioned media from USMB and control conditions (untreated cells, cells treated with microbubbles and ultrasound only were harvested. EVs were measured using flow cytometric immuno-magnetic bead capture assay, immunogold electron microscopy, and western blotting. After USMB, levels of CD9 exposing-EVs significantly increased at 2 and 4 h, whereas levels of CD63 exposing-EVs increased at 2 h. At 24 h, EV levels were comparable to control levels. EVs released after USMB displayed a heterogeneous size distribution profile (30–1200 nm. Typical EV markers CD9, CD63, and alix were enriched in EVs released from USMB-treated FaDu cells. In conclusion, USMB treatment triggers exocytosis leading to the release of EVs from FaDu cells.

  20. Cavitation microstreaming and stress fields created by microbubbles.

    Science.gov (United States)

    Collis, James; Manasseh, Richard; Liovic, Petar; Tho, Paul; Ooi, Andrew; Petkovic-Duran, Karolina; Zhu, Yonggang

    2010-02-01

    Cavitation microstreaming plays a role in the therapeutic action of microbubbles driven by ultrasound, such as the sonoporative and sonothrombolytic phenomena. Microscopic particle-image velocimetry experiments are presented. Results show that many different microstreaming patterns are possible around a microbubble when it is on a surface, albeit for microbubbles much larger than used in clinical practice. Each pattern is associated with a particular oscillation mode of the bubble, and changing between patterns is achieved by changing the sound frequency. Each microstreaming pattern also generates different shear stress and stretch/compression distributions in the vicinity of a bubble on a wall. Analysis of the micro-PIV results also shows that ultrasound-driven microstreaming flows around bubbles are feasible mechanisms for mixing therapeutic agents into the surrounding blood, as well as assisting sonoporative delivery of molecules across cell membranes. Patterns show significant variations around the bubble, suggesting sonoporation may be either enhanced or inhibited in different zones across a cellular surface. Thus, alternating the patterns may result in improved sonoporation and sonothrombolysis. The clear and reproducible delineation of microstreaming patterns based on driving frequency makes frequency-based pattern alternation a feasible alternative to the clinically less desirable practice of increasing sound pressure for equivalent sonoporative or sonothrombolytic effect. Surface divergence is proposed as a measure relevant to sonoporation.

  1. Magnetic resonance properties of Gd(III)-bound lipid-coated microbubbles and their cavitation fragments.

    Science.gov (United States)

    Feshitan, Jameel A; Boss, Michael A; Borden, Mark A

    2012-10-30

    Gas-filled microbubbles are potentially useful theranostic agents for magnetic resonance imaging-guided focused ultrasound surgery (MRIgFUS). Previously, MRI at 9.4 T was used to measure the contrast properties of lipid-coated microbubbles with gadolinium (Gd(III)) bound to lipid headgroups, which revealed that the longitudinal molar relaxivity (r(1)) increased after microbubble fragmentation. This behavior was attributed to an increase in water proton exchange with the Gd(III)-bound lipid fragments caused by an increase in the lipid headgroup area that accompanied the lipid shell monolayer-to-bilayer transition. In this article, we explore this mechanism by comparing the changes in r(1) and its transverse counterpart, r(2)*, after the fragmentation of microbubbles consisting of Gd(III) bound to two different locations on the lipid monolayer shell: the phosphatidylethanolamine (PE) lipid headgroup region or the distal region of the poly(ethylene glycol) (PEG) brush. Nuclear magnetic resonance (NMR) at 1.5 T was used to measure the contrast properties of the various microbubble constructs because this is the most common field strength used in clinical MRI. Results for the lipid-headgroup-labeled Gd(III) microbubbles revealed that r(1) increased after microbubble fragmentation, whereas r(2)* was unchanged. An analysis of PEG-labeled Gd(III) microbubbles revealed that both r(1) and r(2)* decreased after microbubble fragmentation. Further analysis revealed that the microbubble gas core enhanced the transverse MR signal (T(2)*) in a concentration-dependent manner but minimally affected the longitudinal (T(1)) signal. These results illustrate a new method for the use of NMR to measure the biomembrane packing structure and suggest that two mechanisms, proton-exchange enhancement by lipid membrane relaxation and magnetic field inhomogeneity imposed by the gas/liquid interface, may be used to detect and differentiate Gd(III)-labeled microbubbles and their cavitation

  2. Computer simulation of ultrasonic waves propagation; experimental checking

    International Nuclear Information System (INIS)

    Albert, J.C.; Beaujard, L.; Bouchard, A.; Etienne, J.L.

    1976-01-01

    It is shown that the angular spectrum formalism can be applied to transducers used for non destructive testing of metals. This formalism enables for example, the ultrasonic field of any transducer to be determined. Examples are given of measurements in water [fr

  3. Ultrasonic analysis of UO{sub 2} pellets

    Energy Technology Data Exchange (ETDEWEB)

    Bittencourt, Marcelo de S.Q.; Baroni, Douglas B.; Martorelli, Daniel S., E-mail: bittenc@ien.gov.br, E-mail: douglasbaroni@ien.gov.br, E-mail: daniel@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Ultrassom; Dias, Fabio C.; Silva, Jose W.S. da, E-mail: fabio@ird.gov.br, E-mail: wanderley@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Salvaguardas

    2013-07-01

    Ceramic materials have been widely used for various purposes in many different industries due to certain characteristics, such as high melting point and high resistance to corrosion. In the nuclear area, ceramics are of great importance due to the process of fabrication of fuel pellets for nuclear reactors. Generally, high accuracy destructive techniques are used to characterize nuclear materials for fuel fabrication. These techniques usually require costly equipment and facilities, as well as experienced personnel. This paper aims at presenting an analysis methodology for UO2 pellets using a non-destructive ultrasonic technique for porosity measurement. This technique differs from traditional ultrasonic techniques in the sense it uses ultrasonic pulses in frequency domain instead of time domain. Therefore, specific characteristics of the analyzed material are associated with the obtained frequency spectrum. In the present work, four fuel grade UO2 pellets were analyzed and the corresponding results evaluated. (author)

  4. Acoustic Characterization and Enhanced Ultrasound Imaging of Long-Circulating Lipid-Coated Microbubbles.

    Science.gov (United States)

    Li, Hongbo; Yang, Yanye; Zhang, Meimei; Yin, Liping; Tu, Juan; Guo, Xiasheng; Zhang, Dong

    2018-05-01

    A long-circulating lipid-coated ultrasound (US) contrast agent was fabricated to achieve a longer wash-out time and gain more resistance against higher-mechanical index sonication. Systemic physical, acoustic, and in vivo imaging experiments were performed to better understand the underlying mechanism enabling the improvement of contrast agent performance by adjusting the physical and acoustic properties of contrast agent microbubbles. By simply altering the gas core, a kind of US contrast agent microbubble was synthesized with a similar lipid-coating shell as SonoVue microbubbles (Bracco SpA, Milan, Italy) to achieve a longer wash-out time and higher inertial cavitation threshold. To bridge the structure-performance relationship of the synthesized microbubbles, the imaging performance of the microbubbles was assessed in vivo with SonoVue as a control group. The size distribution and inertial cavitation threshold of the synthesized microbubbles were characterized, and the shell parameters of the microbubbles were determined by acoustic attenuation measurements. All of the measurements were compared with SonoVue microbubbles. The synthesized microbubbles had a spherical shape, a smooth, consistent membrane, and a uniform distribution, with an average diameter of 1.484 μm. According to the measured attenuation curve, the synthesized microbubbles resonated at around 2.8 MHz. Although the bubble's shell elasticity (0.2 ± 0.09 N/m) was comparable with SonoVue, it had relatively greater viscosity and inertial cavitation because of the different gas core. Imaging studies showed that the synthesized microbubbles had a longer circulation time and a better chance of fighting against rapid collapse than SonoVue. Nano/micrometer long-circulating lipid-coated microbubbles could be fabricated by simply altering the core composition of SonoVue microbubbles with a higher-molecular weight gas. The smaller diameter and higher inertial cavitation threshold of the

  5. Ultrasonic horn design for ultrasonic machining technologies

    Directory of Open Access Journals (Sweden)

    Naď M.

    2010-07-01

    Full Text Available Many of industrial applications and production technologies are based on the application of ultrasound. In many cases, the phenomenon of ultrasound is also applied in technological processes of the machining of materials. The main element of equipments that use the effects of ultrasound for machining technology is the ultrasonic horn – so called sonotrode. The performance of ultrasonic equipment, respectively ultrasonic machining technologies depends on properly designed of sonotrode shape. The dynamical properties of different geometrical shapes of ultrasonic horns are presented in this paper. Dependence of fundamental modal properties (natural frequencies, mode shapes of various sonotrode shapes for various geometrical parameters is analyzed. Modal analyses of the models are determined by the numerical simulation using finite element method (FEM design procedures. The mutual comparisons of the comparable parameters of the various sonotrode shapes are presented.

  6. Hysteretic Nonlinearity of Sub-harmonic Emission from Ultrasound Contrast Agent Microbubbles

    International Nuclear Information System (INIS)

    Qiu Yuan-Yuan; Zhang Dong; Zheng Hai-Rong

    2011-01-01

    Sub-harmonic contrast imaging promises to improve ultrasound imaging quality by taking advantage of increased contrast to tissue signal. The aim of this study is to examine the hysteretic nonlinearity of sub-harmonic component emitted from microbubbles. Two kinds of microbubble solutions, i.e. Sonovue® and a self-developed contrast agent, are utilized in the study. The hysteretic curves for increasing and decreasing acoustic pressure are theoretically predicted by the Marmottant model and confirmed by measurements. The results reveal that for both microbubble solutions, the development of the rising ramp undergoes three stages, i.e. occurrence, growth and saturation; while hysteresis effect appears in the descending ramp. Sonovue® microbubbles exhibit better sub-harmonic performance over the self-developed UCAs microbubbles due to the difference of elastic properties of the shell. (fundamental areas of phenomenology(including applications))

  7. Electromagnetic ultrasonic guided waves

    CERN Document Server

    Huang, Songling; Li, Weibin; Wang, Qing

    2016-01-01

    This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.

  8. Magnetic targeting to enhance microbubble delivery in an occluded microarterial bifurcation.

    Science.gov (United States)

    de Saint Victor, M; Carugo, D; Barnsley, L C; Owen, J; Coussios, C-C; Stride, E

    2017-09-05

    Ultrasound and microbubbles have been shown to accelerate the breakdown of blood clots both in vitro and in vivo. Clinical translation of this technology is still limited, however, in part by inefficient microbubble delivery to the thrombus. This study examines the obstacles to delivery posed by fluid dynamic conditions in occluded vasculature and investigates whether magnetic targeting can improve microbubble delivery. A 2D computational fluid dynamic model of a fully occluded Y-shaped microarterial bifurcation was developed to determine: (i) the fluid dynamic field in the vessel with inlet velocities from 1-100 mm s -1 (corresponding to Reynolds numbers 0.25-25); (ii) the transport dynamics of fibrinolytic drugs; and (iii) the flow behavior of microbubbles with diameters in the clinically-relevant range (0.6-5 µm). In vitro experiments were carried out in a custom-built microfluidic device. The flow field was characterized using tracer particles, and fibrinolytic drug transport was assessed using fluorescence microscopy. Lipid-shelled magnetic microbubbles were fluorescently labelled to determine their spatial distribution within the microvascular model. In both the simulations and experiments, the formation of laminar vortices and an abrupt reduction of fluid velocity were observed in the occluded branch of the bifurcation, severely limiting drug transport towards the occlusion. In the absence of a magnetic field, no microbubbles reached the occlusion, remaining trapped in the first vortex, within 350 µm from the bifurcation center. The number of microbubbles trapped within the vortex decreased as the inlet velocity increased, but was independent of microbubble size. Application of a magnetic field (magnetic flux density of 76 mT, magnetic flux density gradient of 10.90 T m -1 at the centre of the bifurcation) enabled delivery of microbubbles to the occlusion and the number of microbubbles delivered increased with bubble size and with decreasing inlet

  9. Prevalence and clinical significance of pleural microbubbles in computed tomography of thoracic empyema

    International Nuclear Information System (INIS)

    Smolikov, A.; Smolyakov, R.; Riesenberg, K.; Schlaeffer, F.; Borer, A.; Cherniavsky, E.; Gavriel, A.; Gilad, J.

    2006-01-01

    AIM: To determine the prevalence and clinical significance of pleural microbubbles in thoracic empyema. MATERIALS AND METHODS: The charts of 71 consecutive patients with empyema were retrospectively reviewed for relevant demographic, laboratory, microbiological, therapeutic and outcome data. Computed tomography (CT) images were reviewed for various signs of empyema as well as pleural microbubbles. Two patient groups, with and without microbubbles were compared. RESULTS: Mean patient age was 49 years and 72% were males. Microbubbles were detected in 58% of patients. There were no significant differences between patients with and without microbubbles in regard to pleural fluid chemistry. A causative organism was identified in about 75% of cases in both. There was no difference in the rates of pleural thickening and enhancement, increased extra-pleural fat attenuation, air-fluid levels or loculations. Microbubbles were diagnosed after a mean of 7.8 days from admission. Thoracentesis before CT was performed in 90 and 57% of patients with and without microbubbles (p=0.0015), respectively. Patients with microbubbles were more likely to require repeated drainage (65.9 versus 36.7%, p=0.015) and surgical decortication (31.7 versus 6.7%, p=0.011). Mortalities were 9.8 and 6.6% respectively (p=0.53). CONCLUSION: Pleural microbubbles are commonly encountered in CT imaging of empyema but have not been systematically studied to date. Microbubbles may be associated with adverse outcome such as repeated drainage or surgical decortication. The sensitivity and specificity of this finding and its prognostic implications need further assessment

  10. Theranostic Gd(III)-lipid microbubbles for MRI-guided focused ultrasound surgery.

    Science.gov (United States)

    Feshitan, Jameel A; Vlachos, Fotis; Sirsi, Shashank R; Konofagou, Elisa E; Borden, Mark A

    2012-01-01

    We have synthesized a biomaterial consisting of Gd(III) ions chelated to lipid-coated, size-selected microbubbles for utility in both magnetic resonance and ultrasound imaging. The macrocyclic ligand DOTA-NHS was bound to PE headgroups on the lipid shell of pre-synthesized microbubbles. Gd(III) was then chelated to DOTA on the microbubble shell. The reaction temperature was optimized to increase the rate of Gd(III) chelation while maintaining microbubble stability. ICP-OES analysis of the microbubbles determined a surface density of 7.5 × 10(5) ± 3.0 × 10(5) Gd(III)/μm(2) after chelation at 50 °C. The Gd(III)-bound microbubbles were found to be echogenic in vivo during high-frequency ultrasound imaging of the mouse kidney. The Gd(III)-bound microbubbles also were characterized by magnetic resonance imaging (MRI) at 9.4 T by a spin-echo technique and, surprisingly, both the longitudinal and transverse proton relaxation rates were found to be roughly equal to that of no-Gd(III) control microbubbles and saline. However, the relaxation rates increased significantly, and in a dose-dependent manner, after sonication was used to fragment the Gd(III)-bound microbubbles into non-gas-containing lipid bilayer remnants. The longitudinal (r(1)) and transverse (r(2)) molar relaxivities were 4.0 ± 0.4 and 120 ± 18 mM(-1)s(-1), respectively, based on Gd(III) content. The Gd(III)-bound microbubbles may find application in the measurement of cavitation events during MRI-guided focused ultrasound therapy and to track the biodistribution of shell remnants. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Pulsed focused ultrasound combined with micro-bubble contrast agent can open the blood-brain barrier of gliblastoma patients and improve the efficacy of Temozolomide treatment

    Directory of Open Access Journals (Sweden)

    Qian DONG

    2017-06-01

    Full Text Available Objective This research examined the effect of microbubble contrast agent plus ultrasound on the permeability of blood-brain barrier, and explored whether it affects the efficacy of chemotherapeutic drugs on cerebral glioblastoma. Methods Wistar rats were divided into three groups to find the optimal concentration of ultrasonic contrast agent. To identify the best ultrasound mode that affected the permeability of blood brain barrier, we employed transmission electron microscopy for study of brain ultrastructure. Western blotting was used to detect the tight junction protein claudin-5. Evans blue staining of brain tissues was utilized to identify the best ultrasonic contrast agent concentration and mode. Rat glioma cells (line 9L were injected into Wistar rats. After temozolomide chemotherapy, the tumor size was measured and the tumor marker GFAP in serum was detected by ELISA. Results The best contrast agent concentration which increases permeability of BBB in rats was found to be 1ml/kg and the best ultrasound mode was intermittently- triggered pulses lasting for 10min (with interval was set at 400ms. More Evans blue passed the blood-brain barrier in ultrasonic cavitation effect group than in control group (P<0.05. After temozolomide chemotherapy, more tumor marker GFAP was detected in ultrasonic cavitation effect group than in control group (P<0.05. Conclusion The permeability of BBB was increased and more temozolomide went through BBB when the rats were subjected to intermittently triggered ultrasonic pulses and were injected at contrast agent at 1ml/kg, which could help to achieve better therapeutic efficacy for glioblastoma. DOI: 10.11855/j.issn.0577-7402.2017.05.06

  12. Destructiveness in Political Discourse

    Directory of Open Access Journals (Sweden)

    Яна Александровна Волкова

    2016-12-01

    Full Text Available Destructiveness is among the fundamental discourse categories that play a significant role in the organization of communicative interaction and define the pragmatics of discourse; its study helps to understand some mechanisms and principles of communication, identify strategies and tactics used by a destructive communicative personality. The relevance of this study is determined by the increasing aggressiveness in various types of discourse, and, accordingly, by the need to extend the knowledge of destructive behavior of a communicative personality. The study is based on the theory of discourse-analysis and theory of destructiveness (Z. Harris, T. van Dijk, A. Buss, E. Fromm, D. Ponton, K. Hacker, R. Wodak. N. Arutyunova, V. Karasik, M. Makarov, E. Sheigal et al. Developing the theory of destructiveness and relying on Erich Fromm’s research (1973, we specify the concept of “destructiveness” in relation to the political discourse and compare it with the related concept of aggressiveness. The paper analyses the category of destructiveness in modern US political discourse, using excerpts from the speeches of the candidates for presidency of 2016. Particular attention is paid to the dominant destructive intention - to harm the reputation of the opponent and reduce his political chances, as well as to the functions of verbal aggression: on the one hand - to discredit the opponent, bring accusations, on the other hand - to poison the audience mind against him/her and arouse the feeling of danger posed by a political opponent. The analysis of verbal and nonverbal means of destructiveness in the US political discourse is carried out. The article concludes that abusive remarks of politicians do not result from spontaneous emotional outburst, but from an elaborated destructive strategy where the agonistic nature of political discourse stipulates the use of instrumental aggression (Buss, 1971 for the sake of the conquest of power, lowering the

  13. The non-destructive control, a major constituent of quality

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    The number of continuous research and development works about non-destructive control in all sectors of activity is justified by the increasing need for high quality materials without anomalies. This paper gives a overview of the state of the art and of the recent trends in non-destructive testing researches in different sectors: aeronautics, nuclear industry, automotive industry. New studies and techniques are presented: ultrasonic testing of welds on large diameter pipes, automated applications of ultrasonic testing, ultrasound/computer-aided design coupling, pressure vessels inspection using acoustic emission testing (leaks detection, application to composite materials), numerical radiography (image visualisation and processing), magnetic testing (steel damage detection using Barkhausen noise testing), 'shearography' (detection of the loss of thickness in pipes due to corrosion), X-ray tomography (density measurement of sintered steels, fluid flow calculations in automobile parts). (J.S.)

  14. Ultrasonic testing device

    International Nuclear Information System (INIS)

    Lawrie, W.E.

    1978-01-01

    The ultrasonic transmitter made of polarized ferroelectric ceramic material (lead zirconate titanate) is arranged in a strip carrier which allows it to be introduced between the fuel elements of a fuel subassembly in a water cooled nuclear reactor. The ultrasonic transmitter is insulated relative to the carrier. The echo of the ra dal ultrasonic pulse is recorded which changes as faulty water filled fuel elements are detected. (RW) [de

  15. Non destructive testing: a unique R and D platform in Europe in Saclay

    International Nuclear Information System (INIS)

    On, Dinhill

    2012-01-01

    This article presents the 'Gerim 2' R and D platform which is dedicated to non destructive testing (NDT) in the field of information and communication technology (ICT). It is the first of its kind in Europe and is located in Saclay. It possesses a wide spectrum of NDT technologies: contactless ultrasonic testing, ultrasonic adaptive imagery, automated and multi-resolution X-ray tomography, etc. Founded by public research institutions and industrial partners, this centre is dedicated only to research and development

  16. Non-destructive tests of capsules for JMTR irradiation examination

    International Nuclear Information System (INIS)

    Tanaka, Hidetaka; Nagao, Yoshiharu; Sato, Masashi; Osawa, Kenji

    2007-03-01

    Irradiation examination are increasing in advanced irradiation research for accurate prediction control and evaluation of irradiation parameter such as neutron fluence, etc. by using JMTR. Irradiation capsule internals are therefore structurally complicated recently. This report described the procedure of non destructive tests such as radiographic test, penetrant test, ultrasonic test, etc. for inspection of irradiation capsules in JMTR, and the result of Test-case of confirmation procedure for internal parts of irradiation capsules. (author)

  17. Guidebook on non-destructive testing of concrete structures

    International Nuclear Information System (INIS)

    2002-01-01

    The International Atomic Energy Agency has been active in the promotion of non-destructive testing (NDT) technology for many years. NDT is an important component of a number of IAEA regional projects. This guidebook deals with NDT of concrete. This book covers a wide range of NDT methods including industrial radiography, ultrasonic testing, electromagnetic testing, infrared thermography, etc. Codes, standards, specifications and procedures are also covered

  18. Ultrasound-mediated vascular gene transfection by cavitation of endothelial-targeted cationic microbubbles.

    Science.gov (United States)

    Xie, Aris; Belcik, Todd; Qi, Yue; Morgan, Terry K; Champaneri, Shivam A; Taylor, Sarah; Davidson, Brian P; Zhao, Yan; Klibanov, Alexander L; Kuliszewski, Michael A; Leong-Poi, Howard; Ammi, Azzdine; Lindner, Jonathan R

    2012-12-01

    Ultrasound-mediated gene delivery can be amplified by acoustic disruption of microbubble carriers that undergo cavitation. We hypothesized that endothelial targeting of microbubbles bearing cDNA is feasible and, through optimizing proximity to the vessel wall, increases the efficacy of gene transfection. Contrast ultrasound-mediated gene delivery is a promising approach for site-specific gene therapy, although there are concerns with the reproducibility of this technique and the safety when using high-power ultrasound. Cationic lipid-shelled decafluorobutane microbubbles bearing a targeting moiety were prepared and compared with nontargeted microbubbles. Microbubble targeting efficiency to endothelial adhesion molecules (P-selectin or intercellular adhesion molecule [ICAM]-1) was tested using in vitro flow chamber studies, intravital microscopy of tumor necrosis factor-alpha (TNF-α)-stimulated murine cremaster muscle, and targeted contrast ultrasound imaging of P-selectin in a model of murine limb ischemia. Ultrasound-mediated transfection of luciferase reporter plasmid charge coupled to microbubbles in the post-ischemic hindlimb muscle was assessed by in vivo optical imaging. Charge coupling of cDNA to the microbubble surface was not influenced by the presence of targeting ligand, and did not alter the cavitation properties of cationic microbubbles. In flow chamber studies, surface conjugation of cDNA did not affect attachment of targeted microbubbles at microvascular shear stresses (0.6 and 1.5 dyne/cm(2)). Attachment in vivo was also not affected by cDNA according to intravital microscopy observations of venular adhesion of ICAM-1-targeted microbubbles and by ultrasound molecular imaging of P-selectin-targeted microbubbles in the post-ischemic hindlimb in mice. Transfection at the site of high acoustic pressures (1.0 and 1.8 MPa) was similar for control and P-selectin-targeted microbubbles but was associated with vascular rupture and hemorrhage. At 0.6 MPa

  19. Comparison of microbubble presence in the right heart during mechanochemical and radiofrequency ablation for varicose veins.

    Science.gov (United States)

    Moon, K H; Dharmarajah, B; Bootun, R; Lim, C S; Lane, Tra; Moore, H M; Sritharan, K; Davies, A H

    2017-07-01

    Objective Mechanochemical ablation is a novel technique for ablation of varicose veins utilising a rotating catheter and liquid sclerosant. Mechanochemical ablation and radiofrequency ablation have no reported neurological side-effect but the rotating mechanism of mechanochemical ablation may produce microbubbles. Air emboli have been implicated as a cause of cerebrovascular events during ultrasound-guided foam sclerotherapy and microbubbles in the heart during ultrasound-guided foam sclerotherapy have been demonstrated. This study investigated the presence of microbubbles in the right heart during varicose vein ablation by mechanochemical abaltion and radiofrequency abaltion. Methods Patients undergoing great saphenous vein ablation by mechanochemical abaltion or radiofrequency ablation were recruited. During the ablative procedure, the presence of microbubbles was assessed using transthoracic echocardiogram. Offline blinded image quantification was performed using International Consensus Criteria grading guidelines. Results From 32 recruited patients, 28 data sets were analysed. Eleven underwent mechanochemical abaltion and 17 underwent radiofrequency abaltion. There were no neurological complications. In total, 39% (11/28) of patients had grade 1 or 2 microbubbles detected. Thirty-six percent (4/11) of mechanochemical abaltion patients and 29% (5/17) of radiofrequency ablation patients had microbubbles with no significant difference between the groups ( p=0.8065). Conclusion A comparable prevalence of microbubbles between mechanochemical abaltion and radiofrequency ablation both of which are lower than that previously reported for ultrasound-guided foam sclerotherapy suggests that mechanochemical abaltion may not confer the same risk of neurological events as ultrasound-guided foam sclerotherapy for treatment of varicose veins.

  20. On the relationship between microbubble fragmentation, deflation and broadband superharmonic signal production.

    Science.gov (United States)

    Lindsey, Brooks D; Rojas, Juan D; Dayton, Paul A

    2015-06-01

    Acoustic angiography imaging of microbubble contrast agents uses the superharmonic energy produced from excited microbubbles and enables high-contrast, high-resolution imaging. However, the exact mechanism by which broadband harmonic energy is produced is not fully understood. To elucidate the role of microbubble shell fragmentation in superharmonic signal production, simultaneous optical and acoustic measurements were performed on individual microbubbles at transmit frequencies from 1.75 to 3.75 MHz and pressures near the shell fragmentation threshold for microbubbles of varying diameter. High-amplitude, broadband superharmonic signals were produced with shell fragmentation, whereas weaker signals (approximately 25% of peak amplitude) were observed in the presence of shrinking bubbles. Furthermore, when populations of stationary microbubbles were imaged with a dual-frequency ultrasound imaging system, a sharper decline in image intensity with respect to frame number was observed for 1-μm bubbles than for 4-μm bubbles. Finally, in a study of two rodents, increasing frame rate from 4 to 7 Hz resulted in decreases in mean steady-state image intensity of 27% at 1000 kPa and 29% at 1300 kPa. Although the existence of superharmonic signals when bubbles shrink has the potential to prolong the imaging efficacy of microbubbles, parameters such as frame rate and peak pressure must be balanced with expected re-perfusion rate to maintain adequate contrast during in vivo imaging. Copyright © 2015. Published by Elsevier Inc.

  1. Microbubble enhanced ozonation process for advanced treatment of wastewater produced in acrylic fiber manufacturing industry

    KAUST Repository

    Zheng, Tianlong

    2015-02-02

    This work investigated microbubble-ozonation for the treatment of a refractory wet-spun acrylic fiber wastewater in comparison to macrobubble-ozonation. CODcr, NH3-N, and UV254 of the wastewater were removed by 42%, 21%, and 42%, respectively in the microbubble-ozonation, being 25%, 9%, and 35% higher than the removal rates achieved by macrobubble-ozonation at the same ozone dose. The microbubbles (with average diameter of 45μm) had a high concentration of 3.9×105 counts/mL at a gas flow rate of 0.5L/min. The gas holdup, total ozone mass-transfer coefficient, and average ozone utilization efficiency in the microbubble-ozonation were 6.6, 2.2, and 1.5 times higher than those of the macrobubble-ozonation. Greater generation of hydroxyl radicals and a higher zeta potential of the bubbles were also observed in the microbubble ozonation process. The biodegradability of the wastewater was also significantly improved by microbubble-ozonation, which was ascribed to the enhanced degradation of alkanes, aromatic compounds, and the many other bio-refractory organic compounds in the wastewater. Microbubble-ozonation can thus be a more effective treatment process than traditional macrobubble-ozonation for refractory wastewater produced by the acrylic fiber manufacturing industry.

  2. Augmentation of limb perfusion and reversal of tissue ischemia produced by ultrasound-mediated microbubble cavitation.

    Science.gov (United States)

    Belcik, J Todd; Mott, Brian H; Xie, Aris; Zhao, Yan; Kim, Sajeevani; Lindner, Nathan J; Ammi, Azzdine; Linden, Joel M; Lindner, Jonathan R

    2015-04-01

    Ultrasound can increase tissue blood flow, in part, through the intravascular shear produced by oscillatory pressure fluctuations. We hypothesized that ultrasound-mediated increases in perfusion can be augmented by microbubble contrast agents that undergo ultrasound-mediated cavitation and sought to characterize the biological mediators. Contrast ultrasound perfusion imaging of hindlimb skeletal muscle and femoral artery diameter measurement were performed in nonischemic mice after unilateral 10-minute exposure to intermittent ultrasound alone (mechanical index, 0.6 or 1.3) or ultrasound with lipid microbubbles (2×10(8) IV). Studies were also performed after inhibiting shear- or pressure-dependent vasodilator pathways, and in mice with hindlimb ischemia. Ultrasound alone produced a 2-fold increase (Pultrasound power. Ultrasound-mediated augmentation in flow was greater with microbubbles (3- and 10-fold higher than control for mechanical index 0.6 and 1.3, respectively; Pultrasound and microbubbles by 70% (Pultrasound and ultrasound with microbubbles. In mice with unilateral hindlimb ischemia (40%-50% reduction in flow), ultrasound (mechanical index, 1.3) with microbubbles increased perfusion by 2-fold to a degree that was greater than the control nonischemic limb. Increases in muscle blood flow during high-power ultrasound are markedly amplified by the intravascular presence of microbubbles and can reverse tissue ischemia. These effects are most likely mediated by cavitation-related increases in shear and activation of endothelial nitric oxide synthase. © 2015 American Heart Association, Inc.

  3. Advanced treatment of acrylic fiber manufacturing wastewater with a combined microbubble-ozonation/ultraviolet irradiation process

    KAUST Repository

    Zheng, Tianlong; Zhang, Tao; Wang, Qunhui; Tian, Yanli; Shi, Zhining; Smale, Nicholas; Xu, Banghua

    2015-01-01

    This work investigated the effectiveness of a combination of microbubble-ozonation and ultraviolet (UV) irradiation for the treatment of secondary wastewater effluent of a wet-spun acrylic fiber manufacturing plant. Under reactor condition (ozone dosage of 48 mg L-1, UV fluence rate of 90 mW cm-2, initial pH of 8.0, and reaction time of 120 min), the biodegradability (represented as BOD5/CODcr) of the wastewater improved from 0.18 to 0.47. This improvement in biodegradability is related to the degradation of alkanes, aromatic compounds, and other bio-refractory organic compounds. The combination of microbubble-ozonation and UV irradiation synergistically improved treatment efficiencies by 228%, 29%, and 142% for CODcr, UV254 removal and BOD5/CODcr respectively after 120 min reaction time, as compared with the sum efficiency of microbubble-ozonation alone and UV irradiation alone. Hydroxyl radical production in the microbubble-ozonation/UV process was about 1.8 times higher than the sum production in microbubble-ozonation alone and UV irradiation alone. The ozone decomposition rate in the combined process was about 4.1 times higher than that in microbubble-ozonation alone. The microbubble-ozonation/UV process could be a promising technique for the treatment of bio-refractory organics in the acrylic fiber manufacturing industry. © 2015 Royal Society of Chemistry.

  4. A novel microbubble construct for intracardiac or intravascular MR manometry: a theoretical study

    International Nuclear Information System (INIS)

    Dharmakumar, Rohan; Plewes, Donald B; Wright, Graham A

    2005-01-01

    It has been demonstrated that gas-filled microbubble contrast agents, based on their volume changes, can serve as pressure probes in an MR field. It was recently reported that such an MR-based pressure measurement with microbubbles at 1.5 T must make use of microbubbles that have a volumetric magnetic susceptibility difference with the blood of at least 34 ppm in SI units. In this work, we show through analytical approximations and numerical simulations that such a microbubble formulation can be achieved by coating typical lipid-shelled microbubbles with particles of high dipole moment. Through finite-element simulations we demonstrate that the effective volumetric magnetic susceptibility of a coated microbubble is dependent on the radius, the shell volume fraction and the magnetic susceptibility of the particulates on the shell. Our calculations suggest that a suitable microbubble formulation which will be MR-sensitive to small pressure changes at 1.5 T must be 2-3 μm in radius and be uniformly coated with single-domain magnetic nanoparticles, such as magnetite, at shell volume fractions below 5%

  5. Ultrasonic flow meter

    NARCIS (Netherlands)

    Lötters, Joost Conrad; Snijders, G.J.; Volker, A.W.F.

    2014-01-01

    The invention relates to an ultrasonic flow meter comprising a flow tube for the fluid whose flow rate is to be determined. The flow meter comprises a transmitting element for emitting ultrasonic waves, which is provided on the outer jacket of the flow tube. A receiving element, which is provided on

  6. Size distributions of micro-bubbles generated by a pressurized dissolution method

    Science.gov (United States)

    Taya, C.; Maeda, Y.; Hosokawa, S.; Tomiyama, A.; Ito, Y.

    2012-03-01

    Size of micro-bubbles is widely distributed in the range of one to several hundreds micrometers and depends on generation methods, flow conditions and elapsed times after the bubble generation. Although a size distribution of micro-bubbles should be taken into account to improve accuracy in numerical simulations of flows with micro-bubbles, a variety of the size distribution makes it difficult to introduce the size distribution in the simulations. On the other hand, several models such as the Rosin-Rammler equation and the Nukiyama-Tanazawa equation have been proposed to represent the size distribution of particles or droplets. Applicability of these models to the size distribution of micro-bubbles has not been examined yet. In this study, we therefore measure size distribution of micro-bubbles generated by a pressurized dissolution method by using a phase Doppler anemometry (PDA), and investigate the applicability of the available models to the size distributions of micro-bubbles. Experimental apparatus consists of a pressurized tank in which air is dissolved in liquid under high pressure condition, a decompression nozzle in which micro-bubbles are generated due to pressure reduction, a rectangular duct and an upper tank. Experiments are conducted for several liquid volumetric fluxes in the decompression nozzle. Measurements are carried out at the downstream region of the decompression nozzle and in the upper tank. The experimental results indicate that (1) the Nukiyama-Tanasawa equation well represents the size distribution of micro-bubbles generated by the pressurized dissolution method, whereas the Rosin-Rammler equation fails in the representation, (2) the bubble size distribution of micro-bubbles can be evaluated by using the Nukiyama-Tanasawa equation without individual bubble diameters, when mean bubble diameter and skewness of the bubble distribution are given, and (3) an evaluation method of visibility based on the bubble size distribution and bubble

  7. Effect of microbubble contrast agent during high intensity focused ultrasound ablation on rabbit liver in vivo

    International Nuclear Information System (INIS)

    Chung, Dong Jin; Cho, Se Hyun; Lee, Jae Mun; Hahn, Seong-Tae

    2012-01-01

    Objective: To evaluate the effect of a microbubble contrast agent (SonoVue) during HIFU ablation of a rabbit liver. Materials and methods: HIFU ablations (intensity of 400 W/cm 2 for 4 s, six times, with a 5 s interval between exposures) were performed upon 16 in vivo rabbit livers before and after intravenous injection of a microbubble contrast agent (0.8 ml). A Wilcoxon signed rank test was used to compare mean ablation volume and time required to tissue ablation on real-time US. Shape of ablation and pattern of coagulative necrosis were analyzed by Fisher's exact test. Results: The volume of coagulative necrosis was significantly larger in the combination microbubble and HIFU group than in the HIFU alone group (P < 0.05). Also, time to reach ablation was shorter in the combination microbubble and HIFU group than in the HIFU alone group (P < 0.05). When analyzing the shape of tissue ablation, a pyramidal shape was more prevalently in the HIFU alone group compared to the combination microbubble and HIFU group (P < 0.05). Following an analysis of the pattern of coagulative necrosis, non-cavitary necrosis was found in ten and cavitary necrosis in six of the samples in the combination microbubble and HIFU group. Conversely, non-cavitary necrosis occurred in all 16 samples in the HIFU alone group (P < 0.05). Conclusion: HIFU of in vivo rabbit livers with a microbubble contrast agent produced larger zones of ablation and more cavitary tissue necrosis than without the use of a microbubble contrast agent. Microbubble contrast agents may be useful in tissue ablation by enhancing the treatment effect of HIFU.

  8. Enhanced intracellular delivery of a model drug using microbubbles produced by a microfluidic device.

    Science.gov (United States)

    Dixon, Adam J; Dhanaliwala, Ali H; Chen, Johnny L; Hossack, John A

    2013-07-01

    Focal drug delivery to a vessel wall facilitated by intravascular ultrasound and microbubbles holds promise as a potential therapy for atherosclerosis. Conventional methods of microbubble administration result in rapid clearance from the bloodstream and significant drug loss. To address these limitations, we evaluated whether drug delivery could be achieved with transiently stable microbubbles produced in real time and in close proximity to the therapeutic site. Rat aortic smooth muscle cells were placed in a flow chamber designed to simulate physiological flow conditions. A flow-focusing microfluidic device produced 8 μm diameter monodisperse microbubbles within the flow chamber, and ultrasound was applied to enhance uptake of a surrogate drug (calcein). Acoustic pressures up to 300 kPa and flow rates up to 18 mL/s were investigated. Microbubbles generated by the flow-focusing microfluidic device were stabilized with a polyethylene glycol-40 stearate shell and had either a perfluorobutane (PFB) or nitrogen gas core. The gas core composition affected stability, with PFB and nitrogen microbubbles exhibiting half-lives of 40.7 and 18.2 s, respectively. Calcein uptake was observed at lower acoustic pressures with nitrogen microbubbles (100 kPa) than with PFB microbubbles (200 kPa) (p 3). In addition, delivery was observed at all flow rates, with maximal delivery (>70% of cells) occurring at a flow rate of 9 mL/s. These results demonstrate the potential of transiently stable microbubbles produced in real time and in close proximity to the intended therapeutic site for enhancing localized drug delivery. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  9. Ultrasonic decontamination robot

    International Nuclear Information System (INIS)

    Patenaude, R.S.

    1984-01-01

    An ultrasonic decontamination robot removes radioactive contamination from the internal surface of the inlet and outlet headers, divider plate, tube sheet, and lower portions of tubes of a nuclear power plant steam generator. A programmable microprocessor controller guides the movement of a robotic arm mounted in the header manway. An ultrasonic transducer having a solvent delivery subsystem through which ultrasonic action is achieved is moved by the arm over the surfaces. A solvent recovery suction tube is positioned within the header to remove solvent therefrom while avoiding interference with the main robotic arm. The solvent composition, temperature, pressure, viscosity, and purity are controlled to optimize the ultrasonic scrubbing action. The ultrasonic transducer is controlled at a power density, frequency, and on-off mode cycle such as to optimize scrubbing action within the range of transducer-to-surface distance and solvent layer thickness selected for the particular conditions encountered. Both solvent and transducer control actions are optimized by the programmable microprocessor. (author)

  10. Pinched flow fractionation of microbubbles for ultrasound contrast agent enrichment

    Science.gov (United States)

    Versluis, Michel; Kok, Maarten; Segers, Tim

    2014-11-01

    An ultrasound contrast agent (UCA) suspension contains a wide size distribution of encapsulated microbubbles (typically 1-10 μm in diameter) that resonate to the driving ultrasound field by the intrinsic relationship between bubble size and ultrasound frequency. Medical transducers, however, operate in a narrow frequency range, which severely limits the number of bubbles that contribute to the echo signal. Thus, the sensitivity can be improved by narrowing down the size distribution of the bubble suspension. Here, we present a novel, low-cost, lab-on-a-chip method for the sorting of contrast microbubbles by size, based on a microfluidic separation technique known as pinched flow fractionation (PFF). We show by experimental and numerical investigation that the inclusion of particle rotation is essential for an accurate physical description of the sorting behavior of the larger bubbles. Successful sorting of a bubble suspension with a narrow size distribution (3.0 +/- 0.6 μm) has been achieved with a PFF microdevice. This sorting technique can be easily parallelized, and may lead to a significant improvement in the sensitivity of contrast-enhanced medical ultrasound. This work is supported by NanoNextNL, a micro and nanotechnology consortium of the Government of the Netherlands and 130 partners.

  11. Three-Dimensional Phenomena in Microbubble Acoustic Streaming

    Science.gov (United States)

    Marin, Alvaro; Rossi, Massimiliano; Rallabandi, Bhargav; Wang, Cheng; Hilgenfeldt, Sascha; Kähler, Christian J.

    2015-04-01

    Ultrasound-driven oscillating microbubbles are used as active actuators in microfluidic devices to perform manifold tasks such as mixing, sorting, and manipulation of microparticles. A common configuration consists of side bubbles created by trapping air pockets in blind channels perpendicular to the main channel direction. This configuration consists of acoustically excited bubbles with a semicylindrical shape that generate significant streaming flow. Because of the geometry of the channels, such flows are generally considered as quasi-two-dimensional. Similar assumptions are often made in many other microfluidic systems based on flat microchannels. However, in this Letter we show that microparticle trajectories actually present a much richer behavior, with particularly strong out-of-plane dynamics in regions close to the microbubble interface. Using astigmatism particle-tracking velocimetry, we reveal that the apparent planar streamlines are actually projections of a stream surface with a pseudotoroidal shape. We, therefore, show that acoustic streaming cannot generally be assumed as a two-dimensional phenomenon in confined systems. The results have crucial consequences for most of the applications involving acoustic streaming such as particle trapping, sorting, and mixing.

  12. Frequency dependence and frequency control of microbubble streaming flows

    Science.gov (United States)

    Wang, Cheng; Rallabandi, Bhargav; Hilgenfeldt, Sascha

    2013-02-01

    Steady streaming from oscillating microbubbles is a powerful actuating mechanism in microfluidics, enjoying increased use due to its simplicity of manufacture, ease of integration, low heat generation, and unprecedented control over the flow field and particle transport. As the streaming flow patterns are caused by oscillations of microbubbles in contact with walls of the set-up, an understanding of the bubble dynamics is crucial. Here we experimentally characterize the oscillation modes and the frequency response spectrum of such cylindrical bubbles, driven by a pressure variation resulting from ultrasound in the range of 1 kHz raisebox {-.9ex{stackrel{textstyle <}{˜ }} }f raisebox {-.9ex{stackrel{textstyle <}{˜ }} } 100 kHz. We find that (i) the appearance of 2D streaming flow patterns is governed by the relative amplitudes of bubble azimuthal surface modes (normalized by the volume response), (ii) distinct, robust resonance patterns occur independent of details of the set-up, and (iii) the position and width of the resonance peaks can be understood using an asymptotic theory approach. This theory describes, for the first time, the shape oscillations of a pinned cylindrical bubble at a wall and gives insight into necessary mode couplings that shape the response spectrum. Having thus correlated relative mode strengths and observed flow patterns, we demonstrate that the performance of a bubble micromixer can be optimized by making use of such flow variations when modulating the driving frequency.

  13. Bioinspired preparation of alginate nanoparticles using microbubble bursting.

    Science.gov (United States)

    Elsayed, Mohamed; Huang, Jie; Edirisinghe, Mohan

    2015-01-01

    Nanoparticles are considered to be one of the most advanced tools for drug delivery applications. In this research, alginate (a model hydrophilic polymer) nanoparticles 80 to 200 nm in diameter were obtained using microbubble bursting. The natural process of bubble bursting occurs through a number of stages, which consequently produce nano- and microsized droplets via two main production mechanisms, bubble shell disintegration and a jetting process. In this study, nano-sized droplets/particles were obtained by promoting the disintegrating mechanism and suppressing (limiting) the formation of larger microparticles resulting from the jetting mechanism. A T-junction microfluidic device was used to prepare alginate microbubbles with different sizes in a well-controlled manner. The size of the bubbles was varied by controlling two processing parameters, the solution flow rate and the bubbling pressure. Crucially, the bubble size was found to be the determining factor for inducing (or limiting) the bubble shell disintegration mechanism and the size needed to promote this process was influenced by the properties of the solution used for preparing the bubbles, particularly the viscosity. The size of alginate nanoparticles produced via the disintegration mechanism was found to be directly proportional to the viscosity of the alginate solution. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Velocity field measurement in micro-bubble emission boiling

    International Nuclear Information System (INIS)

    Ito, Daisuke; Saito, Yasushi; Natazuka, Jun

    2017-01-01

    Liquid inlet behavior to a heat surface in micro-bubble emission boiling (MEB) was investigated by flow measurement using particle image velocimetry (PIV). Subcooled pool boiling experiments under atmospheric pressure were carried out using a heat surface with a diameter of 10 mm. An upper end of a heater block made of copper was used as the heat surface. Working fluid was the deionized water and the subcooling was varied from 40 K to 70 K. Three K-type thermocouples were installed in the copper block to measure the temperature gradient, and the heat flux and wall superheat were estimated from these temperature data to make a boiling curve. The flow visualization around the heat surface was carried out using a high-speed video camera and a light sheet. The microbubbles generated in the MEB were used as tracer particles and the velocity field was obtained by PIV analysis of the acquired image sequence. As a result, the higher heat fluxes than the critical heat flux could be obtained in the MEB region. In addition, the distribution characteristics of the velocity in MEB region were studied using the PIV results and the location of the stagnation point in the velocity fields was discussed. (author)

  15. Phased array ultrasonic testing of dissimilar metal pipe weld joints

    International Nuclear Information System (INIS)

    Rajeev, J.; Sankaranarayanan, R.; Sharma, Govind K; Joseph, A.; Purnachandra Rao, B.

    2015-01-01

    Dissimilar metal weld (DMW) joints made of stainless steel and ferritic steel is used in nuclear industries as well as oil and gas industries. These joints are prone to frequent failures which makes the non-destructive testing of dissimilar metal weld joints utmost important for reliable and safe operation of nuclear power plants and oil and gas industries. Ultrasonic inspection of dissimilar metal weld joints is still challenging due to the inherent anisotropic and highly scattering nature. Phased array ultrasonic testing (PAUT) is an advanced technique and its capability has not been fully explored for the inspection of dissimilar metal welds

  16. Electrochemical destruction of nitrosamines

    Energy Technology Data Exchange (ETDEWEB)

    Lejen, T; Volchek, K; Ladanowski, C; Velicogna, D; Whittaker, H [Environment Canada, Ottawa, ON (Canada). Emergencies Engineering Div.

    1996-09-01

    Treatment conditions for the electrolytic destruction of nitrosamines were studied. The joint investigation between Canada and the Ukraine was part of an assessment of hazardous contaminants at former Soviet ICBM missile sites. The electrochemical destruction of N-dimethylnitrosamines (NDMA) on carbon/platinum electrodes was studied under basic and acidic conditions by UV spectroscopy, gas chromatography, mass spectroscopy, and colorimetry. Experiments with a 100 ppm NDMA solution showed that electrolytic-reduction was pH sensitive within a range of pH 0.5 to 4.0. Electrolysis was effective for the reduction of NDMA in strong acidic conditions. 30 refs., 1 tab., 4 figs.

  17. Money Creation and Destruction

    OpenAIRE

    Faure, Salomon; Gersbach, Hans

    2017-01-01

    We study money creation and destruction in today’s monetary architecture and examine the impact of monetary policy and capital regulation in a general equilibrium setting. There are two types of money created and destructed: bank deposits, when banks grant loans to firms or to other banks and central bank money, when the central bank grants loans to private banks. We show that equilibria yield the first-best level of money creation and lending when prices are flexible, regardless of the monet...

  18. Non destructive testing in amusement park

    International Nuclear Information System (INIS)

    Dominguez Marrero, Humberto; Hernandez Torres, Debora; Sendoya Puente, Felix; Herrera Palma, Victoria; Suarez Guerra, Yarelis; Moreno Hernandez, Eduardo; Lopez Hernandez, Pedro

    2009-01-01

    In 2006 began the installation of Chinese amusement parks at several places in Havana City. Structural security is one of the principal tasks that should be done, since the beginning of the services of these installations. The use on Non Destructive Testing Techniques (NDT), has to be development and implemented in order to avoid the possibility of failure during services with a consequence threat to safety for the public presented. In this work it is shown the results of application of NDT techniques and recommendations for the quality control of the different welds and mechanical components presented. Techniques as Visual Examination, Liquid Penetrant and Ultrasonic have been used for these purposes in order to obtain a structural diagnostic in the amusement parks. There are also exposed the use and implementation of international recommendations and Standards, which are very rigorous in its applications for the case of recreation industry. This is a consequence to its social service fundamentally to children and teenage people. (Author)

  19. Transfection of CXCR-4 using microbubble-mediated ultrasound irradiation and liposomes improves the migratory ability of bone marrow stromal cells.

    Science.gov (United States)

    Wang, Gong; Zhuo, Zhongxiong; Zhang, Qian; Xu, Yali; Wu, Shengzheng; Li, Lu; Xia, Hongmei; Gao, Yunhua

    2015-01-01

    Bone marrow stromal cells (BMSCs) have proven useful for the treatment of various human diseases and injuries. However, their reparative capacity is limited by their poor migration and homing ability, which are primarily dependent on the SDF-1/CXCR4 axis. Most subcultured BMSCs lack CXCR4 receptor expression on the cell surface and exhibit impaired migratory capacity. To increase responsiveness to SDF-1 and promote cell migration and survival of cultured BMSCs, we used a combination of ultrasound-targeted microbubble destruction (UTMD) and liposomes to increase CXCR4 expression in vitro. We isolated and cultured rat BMSCs to their third passage and transduced them with recombinant plasmid pDsRed-CXCR4 using microbubble-mediated ultrasound irradiation and liposomes. Compared to some viral vectors, the method we employed here resulted in significantly better transfection efficiency, CXCR4 expression, and technical reproducibility. The benefits of this approach are likely due to the combination of "sonoporation" caused by shockwaves and microjet flow resulting from UTMD-generated cavitation. Following transfection, we performed a transwell migration assay and found that the migration ability of CXCR4-modified BMSCs was 9-fold higher than controls. The methods we describe here provide an effective, safe, non-viral means to achieve high levels of CXCR4 expression. This is associated with enhanced migration of subcultured BMSCs and may be useful for clinical application as well.

  20. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been...

  1. Assessments of Bubble Dynamics Model and Influential Parameters in Microbubble Drag Reduction

    National Research Council Canada - National Science Library

    Skudarnov, P. V; Lin, C. X

    2006-01-01

    .... The effects of mixture density variation, free stream turbulence intensity, free stream velocity, and surface roughness on the microbubble drag reduction were studied using a single phase model based...

  2. A model for an acoustically driven microbubble inside a rigid tube

    KAUST Repository

    Qamar, Adnan; Samtaney, Ravi

    2014-01-01

    A theoretical framework to model the dynamics of acoustically driven microbubble inside a rigid tube is presented. The proposed model is not a variant of the conventional Rayleigh-Plesset category of models. It is derived from the reduced Navier

  3. Microbubbles as contrast agent for in-line x-ray phase-contrast imaging

    International Nuclear Information System (INIS)

    Xi Yan; Zhao Jun; Tang Rongbiao; Wang Yujie

    2011-01-01

    In the present study, we investigated the potential of gas-filled microbubbles as contrast agents for in-line x-ray phase-contrast imaging (PCI) in biomedical applications. When imaging parameters are optimized, the microbubbles function as microlenses that focus the incoming x-rays to form bright spots, which can significantly enhance the image contrast. Since microbubbles have been shown to be safe contrast agents in clinical ultrasonography, this contrast-enhancement procedure for PCI may have promising utility in biomedical applications, especially when the dose of radiation is a serious concern. In this study, we performed both numerical simulations and ex vivo experiments to investigate the formation of the contrast and the effectiveness of microbubbles as contrast agents in PCI.

  4. Correlation between microbubble-induced acoustic cavitation and hemolysis in vitro

    International Nuclear Information System (INIS)

    Zhang Chun-Bing; Liu Zheng; Guo Xia-Sheng; Zhang Dong

    2011-01-01

    Microbubbles promise to enhance the efficiency of ultrasound-mediated drug delivery and gene therapy by taking advantage of artificial cavitation nuclei. The purpose of this study is to examine the ultrasound-induced hemolysis in the application of drug delivery in the presence of microbubbles. To achieve this goal, human red blood cells mixed with microbubbles were exposed to 1-MHz pulsed ultrasound. The hemolysis level was measured by a flow cytometry, and the cavitation dose was detected by a passive cavitation detecting system. The results demonstrate that larger cavitation dose would be generated with the increase of acoustic pressure, which might give rise to the enhancement of hemolysis. Besides the experimental observations, the acoustic pressure dependence of the radial oscillation of microbubble was theoretically estimated. The comparison between the experimental and calculation results indicates that the hemolysis should be highly correlated to the acoustic cavitation. (classical areas of phenomenology)

  5. Tanscranial Threshold of Inertial Cavitation Induced by Diagnosticc Ultrasound and Microbubbles

    NARCIS (Netherlands)

    Liu, J.; Gao, S.; Porter, T.R.; Everbach, C; Shi, W.; Vignon, F.; Powers, J.; Lof, J.; Turner, J.; Xie, F.

    2011-01-01

    Background: Inertial cavitation may cause hazardous bioeffects whileusing ultrasound and microbubble mediated thrombolysis. The purposeof this study was to investigate the influence of ultrasound pulselength and temporal bone on inertial cavitation thresholds within the brain utilizing transtemporal

  6. Effect of Micro-Bubbles in Water on Beam Patterns of Parametric Array

    Science.gov (United States)

    Hashiba, Kunio; Masuzawa, Hiroshi

    2003-05-01

    The improvement in efficiency of a parametric array by nonlinear oscillation of micro-bubbles in water is studied in this paper. The micro-bubble oscillation can increase the nonlinear coefficient of the acoustic medium. The amplitude of the difference-frequency wave along the longitudinal axis and its beam patterns in the field including the layer with micro-bubbles were analyzed using a Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation. As a result, the largest improvement in efficiency was obtained and a narrow parametric beam was formed by forming a layer with micro-bubbles in front of a parametric sound radiator as thick as about the shock formation distance. If the layer becomes significantly thicker than the distance, the beam of the difference-frequency wave in the far-field will become broader. If the layer is significantly thinner than the distance, the intensity level of the wave in the far-field will be too low.

  7. Ultrasonic monitoring of Iberian fat crystallization during cold storage

    International Nuclear Information System (INIS)

    Corona, E; García-Pérez, J V; Santacatalina, J V; Peña, R; Benedito, J

    2012-01-01

    The aim of this work was to evaluate the use of ultrasonic measurements to characterize the crystallization process and to assess the textural changes of Iberian fat and Iberian ham during cold storage. The ultrasonic velocity was measured in two types of Iberian fats (Montanera and Cebo) during cold storage (0, 2, 5, 7 and 10 °C) and in vacuum packaged Iberian ham stored at 6°C for 120 days. The fatty acid profile, thermal behaviour and textural properties of fat were determined. The ultrasonic velocity and textural measurements showed a two step increase during cold storage, which was related with the separate crystallization of two fractions of triglycerides. It was observed that the harder the fat, the higher the ultrasonic velocity. Likewise, Cebo fat resulted harder than Montanera due to a higher content of saturated triglycerides. The ultrasonic velocity in Iberian ham showed an average increase of 55 m/s after 120 days of cold storage due to fat crystallization. Thus, non-destructive ultrasonic technique could be a reliable method to follow the crystallization of fats and to monitor the changes in the textural properties of Iberian ham during cold storage.

  8. Using piezoelectric sensors for ultrasonic pulse velocity measurements in concrete

    International Nuclear Information System (INIS)

    Kee, Seong-Hoon; Zhu, Jinying

    2013-01-01

    The ultrasonic pulse velocity (UPV) test has been a widely used non-destructive testing method for concrete structures. However, the conventional UPV test has limitations in consistency of results and applicability in hard-to-access regions of structures. The authors explore the feasibility of embedded piezoelectric (PZT) sensors for ultrasonic measurements in concrete structures. Two PZT sensors were embedded in a reinforced concrete specimen. One sensor worked as an actuator driven by an ultrasonic pulse-receiver, and another sensor worked as a receiver. A series of ultrasonic tests were conducted to investigate the performance of the embedded sensors in crack-free concrete and concrete specimens having a surface-breaking crack under various external loadings. Signals measured by the embedded sensors show a broad bandwidth with a centre frequency around 80 kHz, and very good coherence in the frequency range from 30 to 180 kHz. Furthermore, experimental variability in ultrasonic pulse velocity and attenuation is substantially reduced compared to previously reported values from conventional UPV equipment. Findings from this study demonstrate that the embedded sensors have great potential as a low-cost solution for ultrasonic transducers for health monitoring of concrete in structures. (paper)

  9. Status report on the destructive and non-destructive examinations of U-bends removed from Trojan steam generator D

    International Nuclear Information System (INIS)

    Aspden, R.G.

    1981-01-01

    The last status report on the non-destructive examination of U-bends removed from Trojan steam generator D was dated July 7, 1980. As part of this activity, the measurement of wall thicknesses on selected U-bends was planned using an ultrasonic gage. These readings were not made because reproducible results could not be obtained using water as the coupling fluid which was necessary to avoid contamination. Three tubes from the same heat were selected for destructive examination at Westinghouse: one leaking U-bend (R1-C6) and two tubes with no indications (R1-C10 and R1-C22). Results of the examination procedure are presented. The non-destructive examination results from the July 7, 1980 report for 29 U-bends are included

  10. Multifunctional Polymer Microbubbles for Advanced Sentinel Lymph Node Imaging and Mapping

    Science.gov (United States)

    2012-06-01

    of thiolated poly(acrylic acid) with fluorescein attached. (b) Bright field image of large bubbles stabilized by polymer and phospholipid...Page 1 of 6 AD_________________ Award Number: W81XWH-11-1-0215 TITLE:   Multifunctional Polymer Microbubbles for Advanced... Polymer Microbubbles for Advanced Sentinel Lymph Node Imaging and Mapping 5b. GRANT NUMBER W81XWH-11-1-0215   5c. PROGRAM ELEMENT NUMBER 6

  11. Passive acoustic mapping of magnetic microbubbles for cavitation enhancement and localization

    International Nuclear Information System (INIS)

    Crake, Calum; Victor, Marie de Saint; Owen, Joshua; Coviello, Christian; Collin, Jamie; Coussios, Constantin-C; Stride, Eleanor

    2015-01-01

    Magnetic targeting of microbubbles functionalized with superparamagnetic nanoparticles has been demonstrated previously for diagnostic (B-mode) ultrasound imaging and shown to enhance gene delivery in vitro and in vivo. In the present work, passive acoustic mapping (PAM) was used to investigate the potential of magnetic microbubbles for localizing and enhancing cavitation activity under focused ultrasound. Suspensions of magnetic microbubbles consisting of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), air and 10 nm diameter iron oxide nanoparticles were injected into a tissue mimicking phantom at different flow velocities (from 0 to 50 mm s −1 ) with or without an applied magnetic field. Microbubbles were excited using a 500 kHz single element focused transducer at peak negative focal pressures of 0.1–1.0 MPa, while a 64 channel imaging array passively recorded their acoustic emissions. Magnetic localization of microbubble-induced cavitation activity was successfully achieved and could be resolved using PAM as a shift in the spatial distribution and increases in the intensity and sustainability of cavitation activity under the influence of a magnetic field. Under flow conditions at shear rates of up to 100 s −1 targeting efficacy was maintained. Application of a magnetic field was shown to consistently increase the energy of cavitation emissions by a factor of 2–5 times over the duration of exposures compared to the case without targeting, which was approximately equivalent to doubling the injected microbubble dose. These results suggest that magnetic targeting could be used to localize and increase the concentration of microbubbles and hence cavitation activity for a given systemic dose of microbubbles or ultrasound intensity. (paper)

  12. A computer-controlled electronic system for the ultrasonic NDT of components for nuclear power stations

    International Nuclear Information System (INIS)

    Rehrmann, M.; Harbecke, D.

    1987-01-01

    The paper describes an automatic ultrasonic testing system combined with a computer-controlled electronics system, called IMPULS I, for the non-destructive testing of components of nuclear reactors. The system can be used for both in-service inspection and for inspection during the manufacturing process. IMPUL I has more functions and less components than conventional ultrasonic systems, and the system gives good reproducible test results and is easy to operate. (U.K.)

  13. Ultrasonic testing X gammagraphy

    International Nuclear Information System (INIS)

    Mello Campos, A.M. de

    1989-01-01

    The experience of 10 years for substituting gammagraphy tests by ultrasonic tests is related. A comparative evaluation of data obtained from both techniques applied to welded butt joints is presented. (author)

  14. Ultrasonic grinding method

    International Nuclear Information System (INIS)

    Miyahara, Shuji.

    1990-01-01

    An ultrasonic generator and a liquid supply nozzle are opposed to an object to be ground and a pump is started in this state to supply an organic solvent. Matters to be decontaminated which adheres to the surface of the object to be ground and are difficult to be removed by a mere mechanical removing method can be eliminated previously by the surface active effect of the organic solvent such as ethanol prior to the oscillation of the ultrasonic generator. Subsequently, when the ultrasonic generator is oscillated, scales in the floated state can be removed simply. Further, since the organic solvent can penetrate to provide the surface active effect even in such a narrow portion that the top end of the ultrasonic generator is difficult to the intruded at the surface of the object to be ground, the decontaminating treatment can be applied also to such a narrow portion. (T.M.)

  15. Improving ultrasound gene transfection efficiency by controlling ultrasound excitation of microbubbles

    Science.gov (United States)

    Fan, Z.; Chen, D.; Deng, C.X.

    2013-01-01

    Ultrasound application in the presence of microbubbles has shown great potential for non-viral gene transfection via transient disruption of cell membrane (sonoporation). However, improvement of its efficiency has largely relied on empirical approaches without consistent and translatable results. The goal of this study is to develop a rational strategy based on new results obtained using novel experimental techniques and analysis to improve sonoporation gene transfection. We conducted experiments using targeted microbubbles that were attached to cell membrane to facilitate sonoporation. We quantified the dynamic activities of microbubbles exposed to pulsed ultrasound and the resulting sonoporation outcome and identified distinct regimes of characteristic microbubble behaviors: stable cavitation, coalescence and translation, and inertial cavitation. We found that inertial cavitation generated the highest rate of membrane poration. By establishing direct correlation of ultrasound-induced bubble activities with intracellular uptake and pore size, we designed a ramped pulse exposure scheme for optimizing microbubble excitation to improve sonoporation gene transfection. We implemented a novel sonoporation gene transfection system using an aqueous two phase system (ATPS) for efficient use of reagents and high throughput operation. Using plasmid coding for the green fluorescence protein (GFP), we achieved a sonoporation transfection efficiency in rate aortic smooth muscle cells (RASMCs) of 6.9% ± 2.2% (n = 9), comparable with lipofection (7.5% ± 0.8%, n = 9). Our results reveal characteristic microbubble behaviors responsible for sonoporation and demonstrated a rational strategy to improve sonoporation gene transfection. PMID:23770009

  16. Effect of albumin and dextrose concentration on ultrasound and microbubble mediated gene transfection in vivo.

    Science.gov (United States)

    Browning, Richard J; Mulvana, Helen; Tang, Meng-Xing; Hajnal, Jo V; Wells, Dominic J; Eckersley, Robert J

    2012-06-01

    Ultrasound and microbubble mediated gene transfection has great potential for site-selective, safe gene delivery. Albumin-based microbubbles have shown the greatest transfection efficiency but have not been optimised specifically for this purpose. Additionally, few studies have highlighted desirable properties for transfection specific microbubbles. In this article, microbubbles were made with 2% or 5% (w/v) albumin and 20% or 40% (w/v) dextrose solutions, yielding four distinct bubble types. These were acoustically characterised and their efficiency in transfecting a luciferase plasmid (pGL4.13) into female, CD1 mice myocardia was measured. For either albumin concentration, increasing the dextrose concentration increased scattering, attenuation and resistance to ultrasound, resulting in significantly increased transfection. A significant interaction was noted between albumin and dextrose; 2% albumin bubbles made with 20% dextrose showed the least transfection but the most transfection with 40% dextrose. This trend was seen for both nonlinear scattering and attenuation behaviour but not for resistance to ultrasound or total scatter. We have determined that the attenuation behaviour is an important microbubble characteristic for effective gene transfection using ultrasound. Microbubble behaviour can also be simply controlled by altering the initial ingredients used during manufacture. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  17. Fundamentals of Medical Ultrasonics

    CERN Document Server

    Postema, Michiel

    2011-01-01

    This book sets out the physical and engineering principles of acoustics and ultrasound as used for medical applications. It covers the basics of linear acoustics, wave propagation, non-linear acoustics, acoustic properties of tissue, transducer components, and ultrasonic imaging modes, as well as the most common diagnostic and therapeutic applications. It offers students and professionals in medical physics and engineering a detailed overview of the technical aspects of medical ultrasonic imaging, whilst serving as a reference for clinical and research staff.

  18. Assessing ultrasonic examination results

    International Nuclear Information System (INIS)

    Deutsch, V.; Vogt, M.

    1977-01-01

    Amongst nondestructive examination methods, the ultrasonic examination plays an important role. The reason why its scope of application is so wide is because the sound conducting capacity is the only property the material of a test specimen has to have. As the fields are so manifold, only main aspects can be described briefly. The list of references, however, is very extensive and gives plenty of information of all the problems concerning the assessment of ultrasonic examination results. (orig./RW) [de

  19. Oscillating microbubbles for selective particle sorting in acoustic microfluidic devices

    Science.gov (United States)

    Rogers, Priscilla; Xu, Lin; Neild, Adrian

    2012-05-01

    In this study, acoustic waves were used to excite a microbubble for selective particle trapping and sorting. Excitation of the bubble at its volume resonance, as necessary to drive strong fluid microstreaming, resulted in the particles being either selectively attracted to the bubble or continuing to follow the local microstreamlines. The operating principle exploited two acoustic phenomena acting on the particle suspension: the drag force arising from the acoustic microstreaming and the secondary Bjerknes force, i.e. the attractive radiation force produced between an oscillating bubble and a non-buoyant particle. It was also found that standing wave fields within the fluid chamber could be used to globally align bubbles and particles for local particle sorting by the bubble.

  20. [Relevance of contrast ultrasound with microbubbles in vascular medecine].

    Science.gov (United States)

    Erdmann, Andreas; Ney, Barbara; Alatri, Adriano; Calanca, Luca; Mazzolai, Lucia

    2016-12-07

    Application of ultrasound contrast media has become a standard in diagnostic imaging in cardiology and in the characterization of focal lesions in multiple organs, especially of the liver. In the past years there was a growing body of evidence for their usefulness in vascular medicine. The development of contrast media, microbubbles with a stabilizing envelope and filled with gaz, small enough to pass through pulmonary capillaries made real-time imaging of organ perfusion possible. Ultrasound contrast media are rapidly eliminated by exhalation and can safely be administered to patients with renal failure. The objective of this review is to describe the basic principles of ultrasound contrast imaging and to inform about vascular applications of contrast ultrasound.

  1. Eliminating high-order scattering effects in optical microbubble sizing.

    Science.gov (United States)

    Qiu, Huihe

    2003-04-01

    Measurements of bubble size and velocity in multiphase flows are important in much research and many industrial applications. It has been found that high-order refractions have great impact on microbubble sizing by use of phase-Doppler anemometry (PDA). The problem has been investigated, and a model of phase-size correlation, which also takes high-order refractions into consideration, is introduced to improve the accuracy of bubble sizing. Hence the model relaxes the assumption of a single-scattering mechanism in a conventional PDA system. The results of simulation based on this new model are compared with those based on a single-scattering-mechanism approach or a first-order approach. An optimization method for accurately sizing air bubbles in water has been suggested.

  2. The use of computers for the performance and analysis of non-destructive testing

    International Nuclear Information System (INIS)

    Edelmann, X.; Pfister, O.

    1988-01-01

    Examples of the use of computers in non-destructive testing are related. Ultrasonic testing is especially addressed. The employment of computers means improvements for the user, the possibility of registering the reflector position, storage of test data and help with documentation. The test can be automated. The introduction of expert systems is expected for the future. 8 figs., 12 refs

  3. Ultrasonic viewing device

    International Nuclear Information System (INIS)

    Ito, Juro.

    1979-01-01

    Purpose: To improve the safety of reactor operation by enabling to detect the states and positions of fuel assemblies over a wide range with a set of ultrasonic viewing device comprising a rotatable ultrasonic transmitter-receiver and a reflector mounted with an adjustable angle. Constitution: A driving portion for a ultrasonic viewing device is provided to a rotary plug closing the opening of a reactor vessel and a guide pipe suspending below the coolant level is provided to the driving portion. An ultrasonic transmitter-receiver is provided at the end of the holder tube in the guide pipe. A reflector is provided at the upper position of the reactor core so as to correspond to the ultrasonic transmitter-receiver. The ultrasonic transmitter-receiver, positioned by the driving portion, performs horizontal movement for scanning the entire surface of the top of the reactor core, as well as vertical movement covering the gap between the upper mechanism on the reactor and the reactor core, whereby the confirmation for the separation of the control rod and the detection for the states of the reactor core can be conducted by the reflection waves from the reflector. (Moriyama, K.)

  4. ULTRASONIC ASSEMBLY [REVIEW

    Directory of Open Access Journals (Sweden)

    PORAV Viorica

    2015-05-01

    Full Text Available The paper exposes the possibility of machine producesers to optimize the costs of clothes assembling. Ultrasonic systems being frequently utilized have many advantages on semi products of synthetic textile and technical textile. First of all, sewing – cutting process can be accomplished under high speeds and rate of losses can be minimized. Cutting seal applications are frequently used for underwear and sportswear. Slicing and unit cutting machines, as well as portable sealing machines are available for labeling sector. Products such as bag, pocket and cover can be sewed in a seamless manner for promotion purposes. All objects in terms of accessories are obtained in same standard. Our quilting machines are preferred in worldwide due to its threadless, high quality sealing. An alternative to the classic sewing assembly, with thread and needles is ultrasonic seaming. In ultrasonic welding, there are no connective bolts, nails, soldering materials, or adhesives necessary to bind the materials together. Ultrasonic is defined as acoustic frequencies above the range audible to the human ear. Ultrasonic frequencies are administered to the fabric from the sonotrode of bonding machine. The high frequency and powerful energy produced, when is release in one special environment, the ultrasound heating this environment. The ability to ultrasonic weld textiles and films depend on their thermoplastic contents and the desired end results. The paper defines the weld ability of more common textiles and films. The welding refers to all types of bonding and sealing, as in point bonding of fabric, or continuous sealing of film.

  5. Microbubble drag reduction in liquid turbulent boundary layers

    International Nuclear Information System (INIS)

    Merkle, C.L.; Deutsch, S.

    1992-01-01

    The interactions between a dense cloud of small bubbles and a liquid turbulent boundary layer are reviewed on the basis of available experimental observations to understand and quantify their capability for reducing skin friction. Gas bubbles are generally introduced into the boundary layer by injection through a porous surface or by electrolysis. After injection, the bubbles stay near the wall in boundary-layer-like fashion giving rise to strong gradients in both velocity and gas concentration. In general, the magnitude of the skin friction reduction increases as the volume of bubbles in the boundary layer is increased until a maximum skin friction reduction of typically 80-90% of the undisturbed skin friction level is reached. The volumetric gas flow required for this maximum is nominally equal to the volume flow of the liquid in the boundary layer. Bubble size estimates indicate that in most microbubble experiments the bubbles have been intermediate in size between the inner and outer scales of the undisturbed boundary layer. Additional studies with other nondimensional bubble sizes would be useful. However, the bubble size is most likely controlled by the injection process, and considerably different conditions would be required to change this ratio appreciably. The trajectories of the bubble clouds are primarily determined by the random effects of turbulence and bubble-bubble interactions. The effects of buoyancy represent a weaker effect. The trajectories are unlike the deterministic trajectory of an individual bubble in a time-averaged boundary layer. Bubbles are most effective in high speed boundary layers and, for the bubble sizes tested to date, produce an effect that persists for some on hundred boundary layer thicknesses. Modeling suggests that microbubbles reduce skin friction by increasing the turbulence Reynolds number in the buffer layer in a manner similar to polymers

  6. Non-destructive control at the Kozloduy NPP; Nerazrushayushchij kontrol` v AEhS `Kozloduy`

    Energy Technology Data Exchange (ETDEWEB)

    Mikhovsky, M [Institute of Mechanics, Bulgarian Academy of Sciences, Sofia (Bulgaria); Skordev, A [SIME-CONTROL, Sofia (Bulgaria); Nichev, V; Tsokov, P; Popova, N [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

    1996-12-31

    A program for technical diagnostics using non-destructive methods is being carried out at the Kozloduy NPP. The main target is to test mechanical equipment integrity (metal control, mechanical stress control, etc.) as well as electrical equipment. Computer methods and simulation are widely used in program implementation. Non-destructive testing is based on methods involving optical, radiation, ultrasonic and magnetic processes. Control procedures are standardised in special technological documents and one of them is described as an example. It refers to ultrasonic control of the austenitic steel welds of the WWER-440 piping system (DU-500). Graphic representing the microstructure of the welds, the distribution of surface ultrasonic wave and the longitudinal and vertically polarised perpendicular waves are presented. 6 refs. 8 figs.

  7. Augmented reality application for training in pipe defects ultrasonic investigation

    Directory of Open Access Journals (Sweden)

    Amza Cătălin Gheorghe

    2017-01-01

    Full Text Available The paper presents the development process of an Augmented Reality (AR application used for training operators in using ultrasonic equipment for non-destructive testing (NDT of pipework. The application provides workers useful information regarding the process steps, the main components of ultrasonic equipment and the proper modality of placing, aligning and moving it on pipe and weld. Using tablet or mobile phone device, an operator can see on screen written details and images on standardized working method, thus offering assistance during the training process. Allowing 3D augmented visualization of ultrasonic equipment overlaid on the real-world environment consisting in pipes and welds, the AR application makes the NDT process easier to understand and learn, as the initial evaluation results showed.

  8. Design - manufacturing and characterization of specific ultrasonic probes

    International Nuclear Information System (INIS)

    Petit, J.

    1985-01-01

    Optimization of ultrasonic examinations requires essentially to determine precisely parameters used for manufacturing of probes and to check characteristics of beams used. The system presented permits an automatic determination of dimensions of beams in conditions which are totally representative of those of their use. In the field of ultrasonic examinations a good estimate or knowledge of sound beams is of great help to solve difficult examination problems. The FRAMATOME's Centre d'Etude et de Recherche en Essais Non Destructifs (CEREND) : (Study and Research Center in Non-Destructive Testing) has developed and elaborated various techniques in order to improve ultrasonic examinations with specific probes. These techniques concern design, manufacturing and characterization of these probes

  9. High-temperature ultrasonic measurements applied to directly heated samples

    International Nuclear Information System (INIS)

    Moore, R.I.; Taylor, R.E.

    1984-01-01

    High-temperature ultrasonic measurements of Young's modulus were made of graphite samples heated directly. The samples were cylindrical rods of the same geometry as that used in the multiproperty apparatus for simultaneous/consecutive measurements of a number of thermophysical properties to high temperatures. The samples were resonated in simple longitudinal vibration modes. Measurements were performed up to 2000 K. Incorporation of ultrasonic measurements of Young's modulus in the capabilities of the multiproperty apparatus is valuable because (i) ultrasonic measurements can be related to normal destructive measurements of this property; (ii) they can be used for screening materials or acceptance testing of specimens; (iii) they can be used to increase the understanding of thermophysical properties and property correlations. (author)

  10. An inverse method for crack characterization from ultrasonic B-Scan images

    International Nuclear Information System (INIS)

    Faur, M.; Roy, O.; Benoist, PH.; Morisseau, PH.

    1996-01-01

    Concern has been expressed about the capabilities of performing non destructive evaluation (NDE) of flaws located near to the outer surface in nuclear pressurized water reactor (PWR) vessels. The ultrasonic examination of PWR is accomplished from the inside with ultrasonic focused transducers working in the pulse echo mode. By recording the echoes as a function of time, the Ascan representation may be obtained. Many ultrasonic flaw detectors used for NDE are based on the simple Ascan concept involving measuring a time interval called 'time of flight'. By combining the Ascan concept synchronized transducer scanning, one can produce Bscan images that are two dimensional descriptions of the flaw interaction with the ultrasonic field. In the following, the flaw is assumed to be an axially oriented crack (the most serious flaw to be found in a pressurized component). In the case of the outer surface cracks (OSC's), analyzing and interpreting ultrasonic Ascan images become difficult because of the various reflections of the ultrasonic beam on the crack and on the outer surface (the so-called corner effect). Methods for automatic interpretation of ultrasonic experimental data are currently under investigation. In this paper, we present an inverse method for determining the geometrical characteristics of OSC's from ultrasonic Bscan images. The direct model used for the inversion procedure predicts synthetic Bscan images of ultrasonic examination of blocks containing planar defects interrogated by focused probes. (authors)

  11. Analysis of ultrasonic techniques for the characterization of microfiltration polymeric membranes

    International Nuclear Information System (INIS)

    Lucas, Carla S.; Baroni, Douglas B.; Costa, Antonio M.L.M.; Bittencourt, Marcelo S.Q.

    2009-01-01

    The use of polymeric membranes is extremely important in several industries such as nuclear, biotechnology, chemical and pharmaceutical. In the nuclear area, for instance, systems based on membrane separation technologies are currently being used in the treatment of radioactive liquid effluent, and new technologies using membranes are being developed at a great rate. The knowledge of the physical characteristics of these membranes, such as, pore size and the pore size distribution, is very important to the membranes separation processes. Only after these characteristics are known is it possible to determine the type and to choose a particular membrane for a specific application. In this work, two ultrasonic non destructive techniques were used to determine the porosity of membranes: pulse echo and transmission. A 25 MHz immersion transducer was used. Ultrasonic signals were acquired, for both techniques, after the ultrasonic waves passed through a microfiltration polymeric membrane of pore size of 0.45 μm and thickness of 180 μm. After the emitted ultrasonic signal crossed the membrane, the received signal brought several information on the influence of the membrane porosity in the standard signal of the ultrasonic wave. The ultrasonic signals were acquired in the time domain and changed to the frequency domain by application of the Fourier Fast Transform (FFT), thus generating the material frequency spectrum. For the pulse echo technique, the ultrasonic spectrum frequency changed after the ultrasonic wave crossed the membrane. With the transmission technique there was only a displacement of the ultrasonic signal at the time domain. (author)

  12. Subharmonic emissions from microbubbles: effect of the driving pulse shape.

    Science.gov (United States)

    Biagi, Elena; Breschi, Luca; Vannacci, Enrico; Masotti, Leonardo

    2006-11-01

    The aims of this work are to investigate the response of the ultrasonic contrast agents (UCA) insonified by different arbitrary-shaped pulses at different acoustic pressures and concentration of the contrast agent focusing on subharmonic emission. A transmission setup was developed in order to insonify the contrast agent contained in a measurement chamber. The transmitted ultrasonic signals were generated by an arbitrary wave generator connected to a linear power amplifier able to drive a single-element transducer. The transmitted ultrasonic pulses that passed through the contrast agent-filled chamber were received by a second transducer or a hydrophone aligned with the first one. The radio frequency (RF) signals were acquired by fast echographic multiparameters multi-image novel apparatus (FEMMINA), which is an echographic platform able to acquire ultrasonic signals in a real-time modality. Three sets of ultrasonic signals were devised in order to evaluate subharmonic response of the contrast agent respect with sinusoidal burst signals used as reference pulses. A decreasing up to 30 dB in subharmonic response was detected for a Gaussian-shaped pulse; differences in subharmonic emission up to 21 dB were detected for a composite pulse (two-tone burst) for different acoustic pressures and concentrations. Results from this experimentation demonstrated that the transmitted pulse shape strongly affects subharmonic emission in spite of a second harmonic one. In particular, the smoothness of the initial portion of the shaped pulses can inhibit subharmonic generation from the contrast agents respect with a reference sinusoidal burst signal. It also was shown that subharmonic generation is influenced by the amplitude and the concentration of the contrast agent for each set of the shaped pulses. Subharmonic emissions that derive from a nonlinear mechanism involving nonlinear coupling among different oscillation modes are strongly affected by the shape of the ultrasonic

  13. Influence of Kaolin in Fly Ash Based Geopolymer Concrete: Destructive and Non-Destructive Testing

    Science.gov (United States)

    Yahya, Z.; Abdullah, M. M. A. B.; Ramli, N. Mohd; Burduhos-Nergis, D. D.; Razak, R. Abd

    2018-06-01

    Development of geopolymer concrete is mainly to reduce the production of ordinary Portland cement (OPC) that adverse the natural effect. Fly ash is a by-product collected from electrical generating power plant which resulted from burning pulverized coal. Since fly ash is waste materials, it can be recycled for future advantages particularly as pozzolanic materials in construction industry. This study focused on the feasibility of fly ash based geopolymer concrete to which kaolin has been added. The main constituents of geopolymer production for this study were class F fly ash, sodium silicate and sodium hydroxide (NaOH) solution. The concentration of NaOH solution was fixed at 12 Molar, ratio of fly ash/alkaline activator and sodium silicate/NaOH fixed at 1.5 and 2.5, respectively. Kaolin was added in range 5% to 15% from the mass of fly ash and all the samples were cured at room temperature. Destructive and non-destructive test were performed on geopolymer concrete to evaluate the best mix proportions that yield the highest strength as well as the quality of the concrete. Compressive strength, flexural strength, rebound hammer and ultrasonic pulse velocity (UPV) result have been obtained. It shown that 5% replacement of kaolin contributed to maximum compressive strength and flexural strength of 40.4 MPa and 12.35 MPa at 28 days. These result was supported by non-destructive test for the same mix proportion.

  14. Mid-infrared pulsed laser ultrasonic testing for carbon fiber reinforced plastics.

    Science.gov (United States)

    Kusano, Masahiro; Hatano, Hideki; Watanabe, Makoto; Takekawa, Shunji; Yamawaki, Hisashi; Oguchi, Kanae; Enoki, Manabu

    2018-03-01

    Laser ultrasonic testing (LUT) can realize contactless and instantaneous non-destructive testing, but its signal-to-noise ratio must be improved in order to measure carbon fiber reinforced plastics (CFRPs). We have developed a mid-infrared (mid-IR) laser source optimal for generating ultrasonic waves in CFRPs by using a wavelength conversion device based on an optical parametric oscillator. This paper reports a comparison of the ultrasonic generation behavior between the mid-IR laser and the Nd:YAG laser. The mid-IR laser generated a significantly larger ultrasonic amplitude in CFRP laminates than a conventional Nd:YAG laser. In addition, our study revealed that the surface epoxy matrix of CFRPs plays an important role in laser ultrasonic generation. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Destructive distillation under pressure

    Energy Technology Data Exchange (ETDEWEB)

    1932-09-08

    A process of destructive distillation of distillable carbonaceous material under pressure is described, consisting of regulating the temperature by introducing the carbonaceous materials to a point where the reaction of hydrogenation has begun but has not stopped, by placing it in indirect heat-exchange with a cooling agent at a critical temperature below the reaction temperature, the agent being under pressure and introduced in the liquid state. Water is used as the cooling agent.

  16. Turbulence enhancement by ultrasonically induced gaseous cavitation in the CO2 saturated water

    International Nuclear Information System (INIS)

    Lee, Seung Youp; Choi, Young Don

    2002-01-01

    Recent primary concern for the design of high performance heat exchanger and highly integrated electronic equipment is to develop an active and creative technologies which enhance the heat transfer without obstructing the coolant flows. In this study, we found through the LDV measurement that the gaseous cavitation induced by ultrasonic vibration applied to the CO 2 saturated water in the square cross-sectioned straight duct flow enhances the turbulence much more than the case of non-ultrasonic or normal ultrasonic conditions without gaseous cavitation does. We also found that gaseous cavitation can enhance effectively the turbulent heat transfer between the heating surfaces and coolants by destructing the viscous sublayer

  17. Biodistribution, kinetics, and biological fate of SPION microbubbles in the rat

    Directory of Open Access Journals (Sweden)

    Barrefelt A

    2013-08-01

    Full Text Available Åsa Barrefelt,1,2,* Maryam Saghafian,2,* Raoul Kuiper,3 Fei Ye,4 Gabriella Egri,5 Moritz Klickermann,5 Torkel B Brismar,1 Peter Aspelin,1 Mamoun Muhammed,4 Lars Dähne,5 Moustapha Hassan2,6 1Department of Clinical Science, Intervention and Technology, Division of Medical Imaging and Technology, Karolinska Institutet, and Department of Radiology, Karolinska University Hospital-Huddinge, Stockholm, Sweden; 2Experimental Cancer Medicine, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden; 3Karolinska Institute Core Facility for Morphologic Phenotype Analysis, Clinical Research Center, Karolinska University Hospital-Huddinge, Stockholm, Sweden; 4Division of Functional Materials, Department of Materials and Nano Physics, Royal Institute of Technology, Stockholm, Sweden; 5Surflay Nanotec GmbH, Berlin, Germany; 6Clinical Research Center, Karolinska University Hospital-Huddinge, Stockholm, Sweden *These authors contributed equally to this work Background: In the present investigation, we studied the kinetics and biodistribution of a contrast agent consisting of poly(vinyl alcohol (PVA microbubbles containing superparamagnetic iron oxide (SPION trapped between the PVA layers (SPION microbubbles. Methods: The biological fate of SPION microbubbles was determined in Sprague-Dawley rats after intravenous administration. Biodistribution and elimination of the microbubbles were studied in rats using magnetic resonance imaging for a period of 6 weeks. The rats were sacrificed and perfusion-fixated at different time points. The magnetic resonance imaging results obtained were compared with histopathologic findings in different organs. Results: SPION microbubbles could be detected in the liver using magnetic resonance imaging as early as 10 minutes post injection. The maximum signal was detected between 24 hours and one week post injection. Histopathology showed the presence of clustered SPION microbubbles predominantly in the lungs from

  18. Ultrasonic characterization of pork meat salting

    International Nuclear Information System (INIS)

    García-Pérez, J V; De Prados, M; Pérez-Muelas, N; Cárcel, J A; Benedito, J

    2012-01-01

    Salting process plays a key role in the preservation and quality of dry-cured meat products. Therefore, an adequate monitoring of salt content during salting is necessary to reach high quality products. Thus, the main objective of this work was to test the ability of low intensity ultrasound to monitor the salting process of pork meat. Cylindrical samples (diameter 36 mm, height 60±10 mm) of Biceps femoris were salted (brine 20% NaCl, w/w) at 2 °C for 1, 2, 4 and 7 days. During salting and at each experimental time, three cylinders were taken in order to measure the ultrasonic velocity at 2 °C. Afterwards, the cylinders were split in three sections (height 20 mm), measuring again the ultrasonic velocity and determining the salt and the moisture content by AOAC standards. In the whole cylinders, moisture content was reduced from 763 (g/kg sample) in fresh samples to 723 (g/kg sample) in samples salted for 7 days, while the maximum salt gain was 37.3 (g/kg sample). Although, moisture and salt contents up to 673 and 118 (g/kg sample) were reached in the sections of meat cylinders, respectively. During salting, the ultrasonic velocity increased due to salt gain and water loss. Thus, significant (p 2 = 0.975) and moisture (R 2 = 0.863) contents. In addition, the change of the ultrasonic velocity with the increase of the salt content showed a good agreement with the Kinsler equation. Therefore, low intensity ultrasound emerges as a potential technique to monitor, in a non destructive way, the meat salting processes carried out in the food industry.

  19. Non destructive Testing (NDT) of concrete containing hematite

    International Nuclear Information System (INIS)

    Mohamad Pauzi Ismail; Noor Azreen Masenwat; Suhairy Sani; Nasharuddin Isa; Mohamad Haniza Mahmud

    2014-01-01

    This paper described the results of Non-destructive ultrasonic and rebound hammer measurements on concrete containing hematite. Local hematite stones were used as aggregates to produce high density concrete for application in X-and gamma shielding. Concrete cube samples (150 mm x 150 mm x 150 mm) containing hematite as coarse aggregates were prepared by changing mix ratio, water to cement ratio (w/c) and types of fine aggregate. All samples were cured in water for 7 days and then tested after 28 days. Density, rebound number(N) and ultrasonic pulse velocity (UPV) of the samples were taken before compressed to failure. The measurement results are explained and discussed. (author)

  20. Fabrication and application of a magnetic-targeting and controlled-release system using ST68-based microbubbles

    International Nuclear Information System (INIS)

    Xing Zhanwen; Ke Hengte; Wang Jinrui; Zhao Bo; Qu Enze; Yue Xiuli; Dai Zhifei

    2013-01-01

    Objective: To manufacture magnetic microbubbles with dual-response to ultrasound and magnetic fields. Methods: Microbubbles of ultrasound contrast agent (ST68) based on a surfactant were prepared by the acoustic cavitation method. Fe 3 O 4 magnetic nanoparticles with negative charge were synthesized using the polyol procedure. Magnetic microbubbles were generated by depositing polyethylenimine and Fe 3 O 4 magnetic nanoparticles alternately onto the microbubbles using the layer-by-layer self-assembly. In vitro ultrasonography was performed on a silicone tube with/without magnetic microbubbles (3 × 10 8 /ml) by a self-made device to observe the movement of magnetic microbubbles under the effects of magnetic field. In vivo imaging was performed on the kidney of New Zealand rabbits before and after the injection of magnetic microbubbles. Results: The Fe 3 O 4 nanoparticles carried a stable negative charge of (-24.6 ± 6.7) mV and more than 98% of the particles were less than 8 μm in diameter, meeting the size requirement of an ultrasound contrast agent for intravenous administration. There was no echoic signal in the silicone tube before injection of magnetic microbubbles, but there were strong echoic signals after injection. After applying a magnetic field, the magnetic microbubbles moved along the direction of the magnetic flux. In vivo ultrasound imaging could not visualize the kidney before injection of magnetic microbubbles, but could remarkably visualize the kidney after injection. Conclusions: The magnetic microbubbles exhibit favorable magnetic targeting and ultrasound contrast enhancement characteristics. Such properties may serve as the foundation to study their potential for simultaneous diagnosis and treatment in the future. (authors)

  1. Oscillatory dynamics of a charged microbubble under ultrasound

    Indian Academy of Sciences (India)

    The stability and oscillations of a gas bubble suspended in a liquid under the ... Other significant applications of ultrasonic forcing of fluids in which studies of ... the context of cavitation in mechanical systems or in the case of bubbles in fluids in.

  2. Low temperature destructive distillation

    Energy Technology Data Exchange (ETDEWEB)

    1938-07-05

    A process is given and apparatus is described for the destructive distillation at low temperature of coal, oil shale, and the like by subjection to the action of a stream of hot gases or superhearted steam, flowing in a closed circuit. Subsequent treatment of the distillation residues with a gas stream containing oxygen results in combustion of the carbon-containing material therein brings to a high temperature the solid residue, in which the process comprises subsequently contacting the hot solid residue with the fluid stream effecting the distillation.

  3. Ultrasonic dip seal maintenance system

    International Nuclear Information System (INIS)

    Poindexter, A.M.; Ricks, H.E.

    1978-01-01

    Disclosed is a system for removing impurities from the surfaces of liquid dip seals and for wetting the metal surfaces of liquid dip seals in nuclear components. The system comprises an ultrasonic transducer that transmits ultrasonic vibrations along an ultrasonic probe to the metal and liquid surfaces of the dip seal thereby loosening and removing those impurities

  4. Artificial Intelligence Assists Ultrasonic Inspection

    Science.gov (United States)

    Schaefer, Lloyd A.; Willenberg, James D.

    1992-01-01

    Subtle indications of flaws extracted from ultrasonic waveforms. Ultrasonic-inspection system uses artificial intelligence to help in identification of hidden flaws in electron-beam-welded castings. System involves application of flaw-classification logic to analysis of ultrasonic waveforms.

  5. Ultrasonic Stir Welding

    Science.gov (United States)

    Nabors, Sammy

    2015-01-01

    NASA Marshall Space Flight Center (MSFC) developed Ultrasonic Stir Welding (USW) to join large pieces of very high-strength metals such as titanium and Inconel. USW, a solid-state weld process, improves current thermal stir welding processes by adding high-power ultrasonic (HPU) energy at 20 kHz frequency. The addition of ultrasonic energy significantly reduces axial, frictional, and shear forces; increases travel rates; and reduces wear on the stir rod, which results in extended stir rod life. The USW process decouples the heating, stirring, and forging elements found in the friction stir welding process allowing for independent control of each process element and, ultimately, greater process control and repeatability. Because of the independent control of USW process elements, closed-loop temperature control can be integrated into the system so that a constant weld nugget temperature can be maintained during welding.

  6. Ultrasonic nondestructive materials characterization

    Science.gov (United States)

    Green, R. E., Jr.

    1986-01-01

    A brief review of ultrasonic wave propagation in solid materials is presented with consideration of the altered behavior in anisotropic and nonlinear elastic materials in comparison with isotropic and linear elastic materials. Some experimental results are described in which ultrasonic velocity and attenuation measurements give insight into materials microstructure and associated mechanical properties. Recent developments with laser beam non-contact generation and detection of ultrasound are presented. The results of several years of experimental measurements using high-power ultrasound are discussed, which provide substantial evidence of the inability of presently accepted theories to fully explain the interaction of ultrasound with solid materials. Finally, a special synchrotron X-ray topographic system is described which affords the possibility of observing direct interaction of ultrasonic waves with the microstructural features of real crystalline solid materials for the first time.

  7. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H.; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been...... vectors. This review briefly introduces the principles behind colour Doppler imaging and describes some clinical applications. It then describes the basic components of conventional colour Doppler systems and the methods used to derive velocity information from the ultrasound signal. Next, a number of new...

  8. Ultrasonic tests. Pt. 2

    International Nuclear Information System (INIS)

    Goebbels, K.

    1980-01-01

    After a basic treatment of ultrasonic wave propagation, of the state-of-the-art methods and the technical background in the preceeding part, advanced ultrasonic NDT techniques are presented here. The discussion of new development includes - manipulation systems, - automation of ultrasonic testing methods, documentation and evaluation. In the middle of this part the main problem areas will be discussed: - detection of defects (e.g. in coarse grained structures and welds), - classification of defects (e.g. discrimination between crack-like and volumetric faults), - sizing of defects. Research in the field of acoustical holography, development of probes and phased arrays, electromagnetic acoustic transducers and signal enhancement are the main contributing parts to the report. (orig./RW)

  9. Extracellular delivery induced by ultrasound and microbubbles in cells

    Science.gov (United States)

    Hussein, Farah; Antonescu, Costin; Karshafian, Raffi

    2017-03-01

    Ultrasound and microbubble treatment (USMB) can enhance the intracellular uptake of molecules, which otherwise would be excluded from the cell, through USMB-mediated transient membrane disruption and through enhanced endocytosis. However, the effect of USMB on the outward movement of molecules from cells is not well understood. This study investigates the effects of USMB on the release of molecules from various cellular compartments including cytoplasm, lysosomes, and recycling endosomes. In vitro ARPE-19 (RPE henceforth) cells were loaded with Alexa fluor-labeled transferrin as a marker for recycling endosomes, LAMP-1 antibody was used to detect the fusion of lysosomes with the plasma membrane, GFP-transfected RPE cells were used to examine the release of GFP from the cytoplasm, and 7-AAD was used to assess cell viability. Subsequently, cells were exposed to USMB (106 cells/mL, 300 kPa peak negative pressure, 1 min treatment duration, and 20 µL/mL Definity microbubbles). Following USMB, the release of the fluorescent markers was examined at 1.5, 11.5, and 21.5 minutes from the start of USMB. The mean fluorescent intensity (MFI) of untreated and USMB treated samples were measured using flow cytometry. USMB increased the extracellular delivery of GFP molecules from the cytoplasm; the MFI in USMB treated GFP-transfected RPE cells decreased by 17% in viable cells and this MFI decreased by 70% in non-viable cells. This could be due to diffusion of GFP through the membrane disruptions induced by USMB. Additionally, the MFI of viable cells stained with LAMP-1 antibody increased by 50% and this increase was 15 folds in the non-viable cells indicating lysosome exocytosis as a mechanism for membrane repair. Furthermore, the MFI of cells loaded with fluorescent transferrin decreased by 22% after USMB treatment in viable cells, indicating a significant increase in transferrin recycling to the cell membrane. However, the increased recycling was not statistically significant

  10. Buoyancy-activated cell sorting using targeted biotinylated albumin microbubbles.

    Directory of Open Access Journals (Sweden)

    Yu-Ren Liou

    Full Text Available Cell analysis often requires the isolation of certain cell types. Various isolation methods have been applied to cell sorting, including fluorescence-activated cell sorting and magnetic-activated cell sorting. However, these conventional approaches involve exerting mechanical forces on the cells, thus risking cell damage. In this study we applied a novel isolation method called buoyancy-activated cell sorting, which involves using biotinylated albumin microbubbles (biotin-MBs conjugated with antibodies (i.e., targeted biotin-MBs. Albumin MBs are widely used as contrast agents in ultrasound imaging due to their good biocompatibility and stability. For conjugating antibodies, biotin is conjugated onto the albumin MB shell via covalent bonds and the biotinylated antibodies are conjugated using an avidin-biotin system. The albumin microbubbles had a mean diameter of 2 μm with a polydispersity index of 0.16. For cell separation, the MDA-MB-231 cells are incubated with the targeted biotin-MBs conjugated with anti-CD44 for 10 min, centrifuged at 10 g for 1 min, and then allowed 1 hour at 4 °C for separation. The results indicate that targeted biotin-MBs conjugated with anti-CD44 antibodies can be used to separate MDA-MB-231 breast cancer cells; more than 90% of the cells were collected in the MB layer when the ratio of the MBs to cells was higher than 70:1. Furthermore, we found that the separating efficiency was higher for targeted biotin-MBs than for targeted avidin-incorporated albumin MBs (avidin-MBs, which is the most common way to make targeted albumin MBs. We also demonstrated that the recovery rate of targeted biotin-MBs was up to 88% and the sorting purity was higher than 84% for a a heterogenous cell population containing MDA-MB-231 cells (CD44(+ and MDA-MB-453 cells (CD44-, which are classified as basal-like breast cancer cells and luminal breast cancer cells, respectively. Knowing that the CD44(+ is a commonly used cancer

  11. A circular aperture array for ultrasonic tomography and quantitative NDE

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, S A

    1998-08-01

    The main topics of this thesis are ultrasonic tomography and ultrasonic determination of elastic stiffness constants. Both issues are based on a synthetic array with transducer elements distributed uniformly along a circular aperture, i.e., a circular aperture array. The issues are treated both theoretically and experimentally by broadband pulse techniques. Ultrasonic tomography, UCT, from a circular aperture is a relatively new imaging technique in Non-destructive Evaluation (NDE) to acquire cross sectional images in bulk materials. A filtered back-projection algorithm is used to reconstruct images in four different experiments and results of attenuation, velocity and reflection tomograms in Plexiglas of AlSi-alloy cylinders are presented. Two kinds of ultrasonic tomography are introduced: bistatic and monostatic imaging. Both techniques are verified experimentally by Plexiglas cylinders. Different reconstruction artifacts are discussed and theoretical resolution constraints are discussed for various configurations of the circular aperture array. The monostatic technique is used in volumetric imaging. In the experimental verification artificial and real discontinuities in a cylindrical AlSi-alloy are compared with similar discontinuities in a Plexiglas specimen. Finally, some limitations to UCT are discussed. The circular aperture array is used to determine five independent elastic stiffness constants of a unidirectional glass/PET (Poly Ethylene Teraphtalate) laminate. Energy flux propagation and attenuation of ultrasonic waves are considered and velocity surfaces are calculated for different planes of interest. Relations between elastic stiffness constants and engineering constants (i.e., Young`s moduli, shear moduli and Poisson`s ratios) are discussed for an orthotropic composite. Six micromechanical theories are reviewed, and expressions predicting the elastic engineering constants are evaluated. The micromechanical predicted elastic stiffness constants for the

  12. Ultrasonic assessment of additive manufactured Ti-6Al-4V

    Science.gov (United States)

    Schehl, Norman; Kramb, Vicki; Dierken, Josiah; Aldrin, John; Schwalbach, Edwin; John, Reji

    2018-04-01

    Additive Manufacturing (AM) processes offer the potential for manufacturing cost savings and rapid insertion into service through production of near net shape components for complicated structures. Use of these parts in high reliability applications such as those in the aerospace industry will require nondestructive characterization methods to ensure post-process material quality in as-built condition. Ultrasonic methods can be used for this quality verification. Depending on the application, the service life of AM components can be sensitive to the part surface condition. The surface roughness and layered structure inherent to the electron-beam powder-bed fusion process necessitates new approaches to evaluate subsurface material integrity in its presence. Experimental methods and data analytics may improve the evaluation of as-built additively manufactured materials. This paper discusses the assessment of additively manufactured EBM Ti-6Al-4V panels using ultrasonic methods and the data analytics applied to evaluate material integrity. The assessment was done as an exploratory study as the discontinuities of interest in these test samples were not known when the measurements were performed. Water immersion ultrasonic techniques, including pulse-echo and through transmission with 10 MHz focused transducers, were used to explore the material integrity of as-built plates. Subsequent destructive mechanical tests of specimens extracted from the plates provided fracture locations indicating critical flaws. To further understand the effect of surface-roughness, an evaluation of ultrasonic response in the presence of as-built surfaces and with the surface removed was performed. The assessment of additive manufactured EBM Ti-6Al-4V panels with ultrasonic techniques indicated that ultrasonic energy was attenuated by the as-built surface roughness. In addition, feature detection was shown to be sensitive to experimental ultrasonic parameters and flaw morphology.

  13. Advances in ultrasound-targeted microbubble-mediated gene therapy for liver fibrosis.

    Science.gov (United States)

    Huang, Cuiyuan; Zhang, Hong; Bai, Ruidan

    2017-07-01

    Hepatic fibrosis develops as a wound-healing scar in response to acute and chronic liver inflammation and can lead to cirrhosis in patients with chronic hepatitis B and C. The condition arises due to increased synthesis and reduced degradation of extracellular matrix (ECM) and is a common pathological sequela of chronic liver disease. Excessive deposition of ECM in the liver causes liver dysfunction, ascites, and eventually upper gastrointestinal bleeding as well as a series of complications. However, fibrosis can be reversed before developing into cirrhosis and has thus been the subject of extensive researches particularly at the gene level. Currently, therapeutic genes are imported into the damaged liver to delay or prevent the development of liver fibrosis by regulating the expression of exogenous genes. One technique of gene delivery uses ultrasound targeting of microbubbles combined with therapeutic genes where the time and intensity of the ultrasound can control the release process. Ultrasound irradiation of microbubbles in the vicinity of cells changes the permeability of the cell membrane by its cavitation effect and enhances gene transfection. In this paper, recent progress in the field is reviewed with emphasis on the following aspects: the types of ultrasound microbubbles, the construction of an ultrasound-mediated gene delivery system, the mechanism of ultrasound microbubble-mediated gene transfer and the application of ultrasound microbubbles in the treatment of liver fibrosis.

  14. Microbubble-based fiber-optic Fabry-Perot pressure sensor for high-temperature application.

    Science.gov (United States)

    Li, Zhe; Jia, Pinggang; Fang, Guocheng; Liang, Hao; Liang, Ting; Liu, Wenyi; Xiong, Jijun

    2018-03-10

    Using arc discharge technology, we fabricated a fiber-optic Fabry-Perot (FP) pressure sensor with a very low temperature coefficient based on a microbubble that can be applied in a high-temperature environment. The thin-walled microbubble can be fabricated by heating the gas-pressurized hollow silica tube (HST) using a commercial fusion splicer. Then, the well-cut single-mode fiber (SMF) was inserted into the microbubble, and they were fused together. Thus, the FP cavity can be formed between the end of the SMF and the inner surface of the microbubble. The diameter of the microbubble can be up to 360 μm with the thickness of the wall being approximately 0.5 μm. Experimental results show that such a sensor has a linear sensitivity of approximately -6.382  nm/MPa, -5.912  nm/MPa at 20°C, and 600°C within the pressure range of 1 MPa. Due to the thermal expansion coefficient of the SMF being slightly larger than that of silica, we can fuse the SMF and the HST with different lengths; thus, the sensor has a very low temperature coefficient of approximately 0.17 pm/°C.

  15. Drag reduction mechanism by microbubble injection within a channel boundary layer

    International Nuclear Information System (INIS)

    Ling Zhen; Hassan, Y.

    2005-01-01

    In this study, the drag reduction due to microbubble injection in the boundary layer of a fully developed turbulent channel flow was investigated. Particle Image Velocimetry (PIV) techniques were taken. The effects of the presence of microbubbles in the boundary layer were assessed. A drag reduction of 38.4% was obtained with void fraction of 4.9%. The algorithms of wavelet auto-correlation maps were applied to the PIV velocity field measurement. Modifications in the wavelet auto-correlation maps due to the presence of microbubbles were studied and compared in three-dimensions. By using 3-D plotting routines and the wavelet auto-correlation maps, it can be deduced from this study that the microbubble injection within the boundary layer increases the turbulent energy of the streamwise velocity components of the large scale (large eddy size, low frequency) range and decreases the energy of the small scale (small eddy size, high frequency) range. The wavelet auto-correlation maps of the normal velocities indicate that the microbubble presence decrease the turbulent energy of normal velocity components for both the large scale (large eddy size, low frequency) and the small scale (small eddy size, high frequency) ranges. (authors)

  16. Microbubbles induce renal hemorrhage when exposed to diagnostic ultrasound in anesthetized rats.

    Science.gov (United States)

    Wible, James H; Galen, Karen P; Wojdyla, Jolette K; Hughes, Michael S; Klibanov, Alexander L; Brandenburger, Gary H

    2002-01-01

    The generation of ultrasound (US) bioeffects using a clinical imaging system is controversial. We tested the hypothesis that the presence of microbubbles in the US field of a medical imager induces biologic effects. Both kidneys of anesthetized rats were insonified for 5 min using a medical imaging system after the administration of microbubbles. One kidney was insonified using a continuous mode (30 Hz) and the opposite kidney was insonified using an intermittent (1 Hz) technique. The microbubbles were exposed to three different transducer frequencies and four transducer output powers. After insonification, the animals were euthanized, the kidneys were removed and their gross appearance scored under "blinded" conditions using a defined scale. After the administration of microbubbles, US imaging of the kidney caused hemorrhage in the renal tissue. The severity and area of hemorrhage increased with an increase in the transducer power and a decrease in the transducer frequency. Intermittent insonification in the presence of microbubbles produced a greater degree of renal hemorrhage than continuous imaging techniques.

  17. Enhancing surface methane fluxes from an oligotrophic lake: exploring the microbubble hypothesis.

    Science.gov (United States)

    McGinnis, Daniel F; Kirillin, Georgiy; Tang, Kam W; Flury, Sabine; Bodmer, Pascal; Engelhardt, Christof; Casper, Peter; Grossart, Hans-Peter

    2015-01-20

    Exchange of the greenhouse gases carbon dioxide (CO2) and methane (CH4) across inland water surfaces is an important component of the terrestrial carbon (C) balance. We investigated the fluxes of these two gases across the surface of oligotrophic Lake Stechlin using a floating chamber approach. The normalized gas transfer rate for CH4 (k600,CH4) was on average 2.5 times higher than that for CO2 (k600,CO2) and consequently higher than Fickian transport. Because of its low solubility relative to CO2, the enhanced CH4 flux is possibly explained by the presence of microbubbles in the lake’s surface layer. These microbubbles may originate from atmospheric bubble entrainment or gas supersaturation (i.e., O2) or both. Irrespective of the source, we determined that an average of 145 L m(–2) d(–1) of gas is required to exit the surface layer via microbubbles to produce the observed elevated k600,CH4. As k600 values are used to estimate CH4 pathways in aquatic systems, the presence of microbubbles could alter the resulting CH4 and perhaps C balances. These microbubbles will also affect the surface fluxes of other sparingly soluble gases in inland waters, including O2 and N2.

  18. Micro-bubble generated by laser irradiation on an individual carbon nanocoil

    International Nuclear Information System (INIS)

    Sun, Yanming; Pan, Lujun; Liu, Yuli; Sun, Tao

    2015-01-01

    Highlights: • We have investigated laser irradiated microbubbles which can be generated at fixed point on surface of an individual carbon nanocoil (CNC) immerged in deionized water. • The microbubble can be operated easily and flexibly. • Based on classical heat and mass transfer theories, the bubble growth data is in good agreement with the simplified model. - Abstract: We have investigated the micro-bubbles generated by laser induction on an individual carbon nanocoil (CNC) immerged in deionized water. The photon energy of the incident focused laser beam is absorbed by CNC and converted to thermal energy, which efficiently vaporizes the surrounding water, and subsequently a micro-bubble is generated at the laser location. The dynamics behavior of bubble generation, including its nucleation, expansion and steady-state, has been studied experimentally and theoretically. We have derived equations to analyze the expansion process of a bubble based on classical heat and mass transfer theories. The conclusion is in good agreement with the experiment. CNC, which acts as a realistic micro-bubble generator, can be operated easily and flexibly

  19. Hydrostatic Pressurization of Lung Surfactant Microbubbles: Observation of a Strain-Rate Dependent Elasticity.

    Science.gov (United States)

    Thomas, Alec N; Borden, Mark A

    2017-11-28

    The microbubble offers a unique platform to study lung surfactant mechanics at physiologically relevant geometry and length scale. In this study, we compared the response of microbubbles (∼15 μm initial radius) coated with pure dipalmitoyl-phosphatidylcholine (DPPC) versus naturally derived lung surfactant (SURVANTA) when subjected to linearly increasing hydrostatic pressure at different rates (0.5-2.3 kPa/s) at room temperature. The microbubbles contained perfluorobutane gas and were submerged in buffered saline saturated with perfluorobutane at atmospheric pressure. Bright-field microscopy showed that DPPC microbubbles compressed spherically and smoothly, whereas SURVANTA microbubbles exhibited wrinkling and smoothing cycles associated with buckling and collapse. Seismograph analysis showed that the SURVANTA collapse amplitude was constant, but the collapse rate increased with the pressurization rate. An analysis of the pressure-volume curves indicated that the dilatational elasticity increased during compression for both shell types. The initial dilatational elasticity for SURVANTA was nearly twice that of DPPC at higher pressurization rates (>1.5 kPa/s), producing a pressure drop of up to 60 kPa across the film prior to condensation of the perfluorobutane core. The strain-rate dependent stiffening of SURVANTA shells likely arises from their composition and microstructure, which provide enhanced in-plane monolayer rigidity and lateral repulsion from surface-associated collapse structures. Overall, these results provide new insights into lung surfactant mechanics and collapse behavior during compression.

  20. Microfluidics-based microbubbles in methylene blue solution for photoacoustic and ultrasound imaging

    Science.gov (United States)

    Das, Dhiman; Sivasubramanian, Kathyayini; Yang, Chun; Pramanik, Manojit

    2018-02-01

    Contrast agents which can be used for more than one bio-imaging technique has gained a lot of attention from researchers in recent years. In this work, a microfluidic device employing a flow-focusing junction, is used for the continuous generation of monodisperse nitrogen microbubbles in methylene blue, an optically absorbing organic dye, for dual-modal photoacoustic and ultrasound imaging. Using an external phase of polyoxyethylene glycol 40 stearate (PEG 40), a non-ionic surfactant, and 50% glycerol solution at a flow rate of 1 ml/hr and gas pressure at 1.75 bar, monodisperse nitrogen microbubbles of diameter 7 microns were obtained. The external phase also contained methylene blue hydrate at a concentration of 1 gm/litre. The monodisperse microbubbles produced a strong ultrasound signal as expected. It was observed that the signal-to-noise (SNR) ratio of the photoacoustic signal for the methylene blue solution in the presence of the monodisperse microbubbles was 68.6% lower than that of methylene blue solution in the absence of microbubbles. This work is of significance because using microfluidics, we can precisely control the bubbles' production rate and bubble size which increases ultrasound imaging efficiency. A uniform size distribution of the bubbles will have narrower resonance frequency bandwidth which will respond well to specific ultrasound frequencies.

  1. Fluid Viscosity Affects the Fragmentation and Inertial Cavitation Threshold of Lipid-Encapsulated Microbubbles.

    Science.gov (United States)

    Helfield, Brandon; Black, John J; Qin, Bin; Pacella, John; Chen, Xucai; Villanueva, Flordeliza S

    2016-03-01

    Ultrasound and microbubble optimization studies for therapeutic applications are often conducted in water/saline, with a fluid viscosity of 1 cP. In an in vivo context, microbubbles are situated in blood, a more viscous fluid (∼4 cP). In this study, ultrahigh-speed microscopy and passive cavitation approaches were employed to investigate the effect of fluid viscosity on microbubble behavior at 1 MHz subject to high pressures (0.25-2 MPa). The propensity for individual microbubble (n = 220) fragmentation was found to significantly decrease in 4-cP fluid compared with 1-cP fluid, despite achieving similar maximum radial excursions. Microbubble populations diluted in 4-cP fluid exhibited decreased wideband emissions (up to 10.2 times), and increasingly distinct harmonic emission peaks (e.g., ultraharmonic) with increasing pressure, compared with those in 1-cP fluid. These results suggest that in vitro studies should consider an evaluation using physiologic viscosity perfusate before transitioning to in vivo evaluations. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  2. Fluid viscosity affects the fragmentation and inertial cavitation threshold of lipid encapsulated microbubbles

    Science.gov (United States)

    Helfield, Brandon; Black, John J.; Qin, Bin; Pacella, John; Chen, Xucai; Villanueva, Flordeliza S.

    2015-01-01

    Ultrasound and microbubble optimization studies for therapeutic applications are often conducted in water/saline, with a fluid viscosity of 1 cP. In an in vivo context, microbubbles are situated in blood, a more viscous fluid (~4 cP). In this study, ultra-high speed microscopy and passive cavitation approaches were employed to investigate the effect of fluid viscosity on microbubble behavior at 1 MHz subject to high pressures (0.25 – 2 MPa). The propensity for individual microbubble (n=220) fragmentation was shown to significantly decrease in 4 cP fluid as compared to 1 cP fluid, despite achieving similar maximum radial excursions. Microbubble populations diluted in 4 cP fluid exhibited decreased wideband emissions (up to 10.2 times), and increasingly distinct harmonic emission peaks (e.g. ultraharmonic) with increasing pressure as compared to 1 cP fluid. These results suggest that in vitro studies should consider an evaluation using physiologic viscosity perfusate before transitioning to in vivo evaluations. PMID:26674676

  3. Detection of tissue coagulation by decorrelation of ultrasonic echo signals in cavitation-enhanced high-intensity focused ultrasound treatment.

    Science.gov (United States)

    Yoshizawa, Shin; Matsuura, Keiko; Takagi, Ryo; Yamamoto, Mariko; Umemura, Shin-Ichiro

    2016-01-01

    A noninvasive technique to monitor thermal lesion formation is necessary to ensure the accuracy and safety of high-intensity focused ultrasound (HIFU) treatment. The purpose of this study is to ultrasonically detect the tissue change due to thermal coagulation in the HIFU treatment enhanced by cavitation microbubbles. An ultrasound imaging probe transmitted plane waves at a center frequency of 4.5 MHz. Ultrasonic radio-frequency (RF) echo signals during HIFU exposure at a frequency of 1.2 MHz were acquired. Cross-correlation coefficients were calculated between in-phase and quadrature (IQ) data of two B-mode images with an interval time of 50 and 500 ms for the estimation of the region of cavitation and coagulation, respectively. Pathological examination of the coagulated tissue was also performed to compare with the corresponding ultrasonically detected coagulation region. The distribution of minimum hold cross-correlation coefficient between two sets of IQ data with 50-ms intervals was compared with a pulse inversion (PI) image. The regions with low cross-correlation coefficients approximately corresponded to those with high brightness in the PI image. The regions with low cross-correlation coefficients in 500-ms intervals showed a good agreement with those with significant change in histology. The results show that the regions of coagulation and cavitation could be ultrasonically detected as those with low cross-correlation coefficients between RF frames with certain intervals. This method will contribute to improve the safety and accuracy of the HIFU treatment enhanced by cavitation microbubbles.

  4. Augmented reality application for industrial non-destructive inspection training

    Science.gov (United States)

    Amza, Catalin Gheorghe; Zapciu, Aurelian; Teodorescu, Octav

    2018-02-01

    Such a technology - Augmented Reality (AR) has great potential of use, especially for training purposes of new operators on using expensive equipment. In this context, the paper presents an augmented reality training system developed for phased-array ultrasonic non-destructive testing (NDT) equipment. The application has been developed using Unity 5.6.0 game-engine platform integrated with Vuforia sdk toolkit for devices with Android operating system. The test results performed by several NDT operators showed good results, thus proving the potential of using the application in the industrial field.

  5. Algae separation from urban landscape water using a high density microbubble layer enhanced by micro-flocculation.

    Science.gov (United States)

    Chen, Shuwen; Xu, Jingcheng; Liu, Jia; Wei, Qiaoling; Li, Guangming; Huang, Xiangfeng

    2014-01-01

    Eutrophication of raw water results in outbreaks of algae, which hinders conventional water treatment. In this study, high density microbubble layers combined with micro-flocculation was adopted to remove algae from urban landscape water, and the effects of pressure, hydraulic loading, microbubble layer height and flocculation dosage on the removal efficiency for algae were studied. The greatest removal efficiency for algae, chemical oxygen demand, nitrogen and phosphorus was obtained at 0.42 MPa with hydraulic loading at 5 m/h and a flocculation dosage of 4 mg/L using a microbubble layer with a height of 130 cm. Moreover, the size, clearance distance and concentration of microbubbles were found to be affected by pressure and the height of the microbubble layer. Based on the study, this method was an alternative for algae separation from urban landscape water and water purification.

  6. Optical micro-bubble resonators as promising biosensors

    Science.gov (United States)

    Giannetti, A.; Barucci, A.; Berneschi, S.; Cosci, A.; Cosi, F.; Farnesi, D.; Nunzi Conti, G.; Pelli, S.; Soria, S.; Tombelli, S.; Trono, C.; Righini, G. C.; Baldini, F.

    2015-05-01

    Recently, optical micro-bubble resonators (OMBRs) have gained an increasing interest in many fields of photonics thanks to their particular properties. These hollow microstructures can be suitable for the realization of label - free optical biosensors by combining the whispering gallery mode (WGM) resonator properties with the intrinsic capability of integrated microfluidics. In fact, the WGMs are morphology-dependent modes: any change on the OMBR inner surface (due to chemical and/or biochemical binding) causes a shift of the resonance position and reduces the Q factor value of the cavity. By measuring this shift, it is possible to obtain information on the concentration of the analyte to be detected. A crucial step for the development of an OMBR-based biosensor is constituted by the functionalization of its inner surface. In this work we report on the development of a physical and chemical process able to guarantee a good homogeneity of the deposed bio-layer and, contemporary, to preserve a high quality factor Q of the cavity. The OMBR capability of working as bioassay was proved by different optical techniques, such as the real time measurement of the resonance broadening after each functionalization step and fluorescence microscopy.

  7. Optimized open-flow mixing: insights from microbubble streaming

    Science.gov (United States)

    Rallabandi, Bhargav; Wang, Cheng; Guo, Lin; Hilgenfeldt, Sascha

    2015-11-01

    Microbubble streaming has been developed into a robust and powerful flow actuation technique in microfluidics. Here, we study it as a paradigmatic system for microfluidic mixing under a continuous throughput of fluid (open-flow mixing), providing a systematic optimization of the device parameters in this practically important situation. Focusing on two-dimensional advective stirring (neglecting diffusion), we show through numerical simulation and analytical theory that mixing in steady streaming vortices becomes ineffective beyond a characteristic time scale, necessitating the introduction of unsteadiness. By duty cycling the streaming, such unsteadiness is introduced in a controlled fashion, leading to exponential refinement of the advection structures. The rate of refinement is then optimized for particular parameters of the time modulation, i.e. a particular combination of times for which the streaming is turned ``on'' and ``off''. The optimized protocol can be understood theoretically using the properties of the streaming vortices and the throughput Poiseuille flow. We can thus infer simple design principles for practical open flow micromixing applications, consistent with experiments. Current Address: Mechanical and Aerospace Engineering, Princeton University.

  8. Three-dimensional features on oscillating microbubbles streaming flows

    Science.gov (United States)

    Rossi, Massimiliano; Marin, Alvaro G.; Wang, Cheng; Hilgenfeldt, Sascha; Kähler, Christian J.

    2013-11-01

    Ultrasound-driven oscillating micro-bubbles have been used as active actuators in microfluidic devices to perform manifold tasks such as mixing, sorting and manipulation of microparticles. A common configuration consists in side-bubbles, created by trapping air pockets in blind channels perpendicular to the main channel direction. This configuration results in bubbles with a semi-cylindrical shape that creates a streaming flow generally considered quasi two-dimensional. However, recent experiments performed with three-dimensional velocimetry methods have shown how microparticles can present significant three-dimensional trajectories, especially in regions close to the bubble interface. Several reasons will be discussed such as boundary effects of the bottom/top wall, deformation of the bubble interface leading to more complex vibrational modes, or bubble-particle interactions. In the present investigation, precise measurements of particle trajectories close to the bubble interface will be performed by means of 3D Astigmatic Particle Tracking Velocimetry. The results will allow us to characterize quantitatively the three-dimensional features of the streaming flow and to estimate its implications in practical applications as particle trapping, sorting or mixing.

  9. Ultrasonic weld testing.

    Science.gov (United States)

    1970-12-01

    The study was broken down into two phases. Phase I consisted of a laboratory investigation of test specimens to determine the reliability of the ultrasonic equipment and testing procedure. Phase II was a field study where the knowledge, skills and ab...

  10. Ultrasonic leak detection

    International Nuclear Information System (INIS)

    Murphy, R.V.

    1977-01-01

    A scanning ultrasonic microphone was used to detect the presence and locate the sources of hydraulic noises in piping systems in a reactor environment. The intensity changes of the noises correspond to changes of flow conditions within the system caused by throttled valves, flow rate changes, and leaks. (author)

  11. Micro-bubble morphologies following drop impacts onto a pool surface

    KAUST Repository

    Thoroddsen, Sigurdur T; Thoraval, M.-J.; Takehara, K.; Etoh, T.G.

    2012-01-01

    When a drop impacts at low velocity onto a pool surface, a hemispheric air layer cushions and can delay direct contact. Herein we use ultra-high-speed video to study the rupture of this layer, to explain the resulting variety of observed distribution of bubbles. The size and distribution of micro-bubbles is determined by the number and location of the primary punctures. Isolated holes lead to the formation of bubble necklaces when the edges of two growing holes meet, whereas bubble nets are produced by regular shedding of micro-bubbles from a sawtooth edge instability. For the most viscous liquids the air film contracts more rapidly than the capillary-viscous velocity through repeated spontaneous ruptures of the edge. From the speed of hole opening and the total volume of micro-bubbles we conclude that the air sheet ruptures when its thickness approaches ?100.

  12. Micro-bubble morphologies following drop impacts onto a pool surface

    KAUST Repository

    Thoroddsen, Sigurdur T.

    2012-10-01

    When a drop impacts at low velocity onto a pool surface, a hemispheric air layer cushions and can delay direct contact. Herein we use ultra-high-speed video to study the rupture of this layer, to explain the resulting variety of observed distribution of bubbles. The size and distribution of micro-bubbles is determined by the number and location of the primary punctures. Isolated holes lead to the formation of bubble necklaces when the edges of two growing holes meet, whereas bubble nets are produced by regular shedding of micro-bubbles from a sawtooth edge instability. For the most viscous liquids the air film contracts more rapidly than the capillary-viscous velocity through repeated spontaneous ruptures of the edge. From the speed of hole opening and the total volume of micro-bubbles we conclude that the air sheet ruptures when its thickness approaches ?100.

  13. Pancreatic cancer cell detection by targeted lipid microbubbles and multiphoton imaging

    Science.gov (United States)

    Cromey, Benjamin; McDaniel, Ashley; Matsunaga, Terry; Vagner, Josef; Kieu, Khanh Quoc; Banerjee, Bhaskar

    2018-04-01

    Surgical resection of pancreatic cancer represents the only chance of cure and long-term survival in this common disease. Unfortunately, determination of a cancer-free margin at surgery is based on one or two tiny frozen section biopsies, which is far from ideal. Not surprisingly, cancer is usually left behind and is responsible for metastatic disease. We demonstrate a method of receptor-targeted imaging using peptide ligands, lipid microbubbles, and multiphoton microscopy that could lead to a fast and accurate way of examining the entire cut surface during surgery. Using a plectin-targeted microbubble, we performed a blinded in-vitro study to demonstrate avid binding of targeted microbubbles to pancreatic cancer cells but not noncancerous cell lines. Further work should lead to a much-needed point-of-care diagnostic test for determining clean margins in oncologic surgery.

  14. Intravascular forward-looking ultrasound transducers for microbubble-mediated sonothrombolysis.

    Science.gov (United States)

    Kim, Jinwook; Lindsey, Brooks D; Chang, Wei-Yi; Dai, Xuming; Stavas, Joseph M; Dayton, Paul A; Jiang, Xiaoning

    2017-06-14

    Effective removal or dissolution of large blood clots remains a challenge in clinical treatment of acute thrombo-occlusive diseases. Here we report the development of an intravascular microbubble-mediated sonothrombolysis device for improving thrombolytic rate and thus minimizing the required dose of thrombolytic drugs. We hypothesize that a sub-megahertz, forward-looking ultrasound transducer with an integrated microbubble injection tube is more advantageous for efficient thrombolysis by enhancing cavitation-induced microstreaming than the conventional high-frequency, side-looking, catheter-mounted transducers. We developed custom miniaturized transducers and demonstrated that these transducers are able to generate sufficient pressure to induce cavitation of lipid-shelled microbubble contrast agents. Our technology demonstrates a thrombolysis rate of 0.7 ± 0.15 percent mass loss/min in vitro without any use of thrombolytic drugs.

  15. Transit of micro-bubbles through the pulmonary circulation of Thoroughbred horses during exercise.

    Science.gov (United States)

    La Gerche, A; Daffy, J R; Mooney, D J; Forbes, G; Davie, A J

    2013-10-01

    It has been observed that microbubbles may pass through the pulmonary circulation of dogs and humans during exercise. In humans, this phenomenon has been associated with lower pulmonary artery pressures, enhanced right ventricular function and greater exercise capacity. In the exercising Thoroughbred horse, extraordinarily high cardiac outputs exert significant pulmonary vascular stresses. The aim of this study was to determine, using contrast echocardiography, whether Thoroughbred horses performing strenuous exercise developed pulmonary transit of agitated contrast microbubbles (PTAC). At rest, agitated contrast was observed in the right ventricle, but not in the left ventricle. However, post-exercise microbubbles were observed in the left ventricle, confirming the occurrence of PTAC with exercise but not at rest. Further investigation is warranted to investigate whether this phenomenon may be associated with superior physiology and performance measures as has been implicated in other species. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Alkali cyanides; destructive distillation

    Energy Technology Data Exchange (ETDEWEB)

    Clancy, J C

    1925-12-02

    The destructive distillation of carbonaceous substances can be accomplished by heating them in a bath of molten alkali and cyanide. Liquid hydrocarbons are produced. The separation of the cyanide from the coke or carbonaceous residues by filtration leaves a substantial quantity of cyanide absorbed by the carbon. A feasible method for removal has been developed by mixing the mixture of cyanide and coke with sodium carbonate or other alkali in the molten state, then treating this substance with nitrogen with or without ammonia to convert most of the carbon to cyanide. The carbonaceous material may be mixed with a liquid hydrocarbon such as petroleum, shale oil, or heavy tar oil, heated, and introduced below the surface of the liquid cyanide which partially decomposes and hydrogenates the coal to increase the yield of hydrocarbons. Dry ammonia may be bubbled through the reaction mixture to effect agitation and to form more cyanide.

  17. Destructive distillation: oils

    Energy Technology Data Exchange (ETDEWEB)

    West, J; Glover, S

    1918-01-31

    Canned and other coals are destructively distilled in continuously operated vertical retorts which at their upper portions are maintained at temperatures suitable for low temperature oil distillation such as about 700/sup 0/C, and at their lower portions the temperature is higher and such as to be suitable for the production of gas, e.g., about 1400/sup 0/C. Superheated steam is introduced into the lower portion of the retort, preferably by means of the arrangement described in Specification 120,458, and this is converted into blue water gas which assists the distillation in the center of the coal charge. The retorts are preferably such as are described in Specifications 2663/07 and 7757/14.

  18. Ultrasonic Bat Deterrent Technology

    Energy Technology Data Exchange (ETDEWEB)

    Kinzie, Kevin; Rominger, Kathryn M.

    2017-12-14

    The project objective was to advance the development and testing of an Near commercial bat-deterrent system with a goal to increase the current GE deterrent system effectiveness to over 50% with broad species applicability. Additionally, the research supported by this program has provided insights into bat behavior and ultrasonic deterrent design that had not previously been explored. Prior research and development had demonstrated the effectiveness of a commercial-grade, air-powered, ultrasonic bat deterrent to be between 30-50% depending upon the species of bat. However, the previous research provided limited insight into the behavioral responses of bats in the presence of ultrasonic deterrent sound fields that could be utilized to improve effectiveness. A unique bat flight room was utilized to observe the behavioral characteristics of bats in the presence of ultrasonic sound fields. Behavioral testing in the bat flight facility demonstrated that ultrasonic sounds similar to those produced by the GE deterrent influenced the activities and behaviors, primarily those associated with foraging, of the species exposed. The study also indicated that continuous and pulsing ultrasonic signals had a similar effect on the bats, and confirmed that as ultrasonic sounds attenuate, their influence on the bats’ activities and behavior decreases. Ground testing at Wolf Ridge Wind, LLC and Shawnee National Forest assessed both continuous and pulsing deterrent signals emitted from the GE deterrent system and further enhanced the behavioral understanding of bats in the presence of the deterrent. With these data and observations, the existing 4-nozzle continuous, or steady, emission ultrasonic system was redesigned to a 6-nozzle system that could emit a pulsing signal covering a larger air space around a turbine. Twelve GE 1.6-100 turbines were outfitted with the deterrent system and a formal three-month field study was performed using daily carcass searches beneath the 12

  19. Improving ultrasound gene transfection efficiency by controlling ultrasound excitation of microbubbles.

    Science.gov (United States)

    Fan, Z; Chen, D; Deng, C X

    2013-09-28

    Ultrasound application in the presence of microbubbles has shown great potential for non-viral gene transfection via transient disruption of cell membrane (sonoporation). However, improvement of its efficiency has largely relied on empirical approaches without consistent and translatable results. The goal of this study is to develop a rational strategy based on new results obtained using novel experimental techniques and analysis to improve sonoporation gene transfection. In this study, we conducted experiments using targeted microbubbles that were attached to cell membrane to facilitate sonoporation. We quantified the dynamic activities of microbubbles exposed to pulsed ultrasound and the resulting sonoporation outcome, and identified distinct regimes of characteristic microbubble behaviors: stable cavitation, coalescence and translation, and inertial cavitation. We found that inertial cavitation generated the highest rate of membrane poration. By establishing direct correlation of ultrasound-induced bubble activities with intracellular uptake and pore size, we designed a ramped pulse exposure scheme for optimizing microbubble excitation to improve sonoporation gene transfection. We implemented a novel sonoporation gene transfection system using an aqueous two phase system (ATPS) for efficient use of reagents and high throughput operation. Using plasmids coding for the green fluorescence protein (GFP), we achieved a sonoporation transfection efficiency in rate aortic smooth muscle cells (RASMCs) of 6.9%±2.2% (n=9), comparable with lipofection (7.5%±0.8%, n=9). Our results reveal characteristic microbubble behaviors responsible for sonoporation and demonstrated a rational strategy to improve sonoporation gene transfection. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Effect of acoustic parameters on the cavitation behavior of SonoVue microbubbles induced by pulsed ultrasound.

    Science.gov (United States)

    Lin, Yutong; Lin, Lizhou; Cheng, Mouwen; Jin, Lifang; Du, Lianfang; Han, Tao; Xu, Lin; Yu, Alfred C H; Qin, Peng

    2017-03-01

    SonoVue microbubbles could serve as artificial nuclei for ultrasound-triggered stable and inertial cavitation, resulting in beneficial biological effects for future therapeutic applications. To optimize and control the use of the cavitation of SonoVue bubbles in therapy while ensuring safety, it is important to comprehensively understand the relationship between the acoustic parameters and the cavitation behavior of the SonoVue bubbles. An agarose-gel tissue phantom was fabricated to hold the SonoVue bubble suspension. 1-MHz transmitting transducer calibrated by a hydrophone was used to trigger the cavitation of SonoVue bubbles under different ultrasonic parameters (i.e., peak rarefactional pressure (PRP), pulse repetition frequency (PRF), and pulse duration (PD)). Another 7.5-MHz focused transducer was employed to passively receive acoustic signals from the exposed bubbles. The ultraharmonics and broadband intensities in the acoustic emission spectra were measured to quantify the extent of stable and inertial cavitation of SonoVue bubbles, respectively. We found that the onset of both stable and inertial cavitation exhibited a strong dependence on the PRP and PD and a relatively weak dependence on the PRF. Approximate 0.25MPa PRP with more than 20μs PD was considered to be necessary for ultraharmonics emission of SonoVue bubbles, and obvious broadband signals started to appear when the PRP exceeded 0.40MPa. Moreover, the doses of stable and inertial cavitation varied with the PRP. The stable cavitation dose initially increased with increasing PRP, and then decreased rapidly after 0.5MPa. By contrast, the inertial cavitation dose continuously increased with increasing PRP. Finally, the doses of both stable and inertial cavitation were positively correlated with PRF and PD. These results could provide instructive information for optimizing future therapeutic applications of SonoVue bubbles. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. In-Situ Characterization of Isotropic and Transversely Isotropic Elastic Properties Using Ultrasonic Wave Velocities

    NARCIS (Netherlands)

    Pant, S; Laliberte, J; Martinez, M.J.; Rocha, B.

    2016-01-01

    In this paper, a one-sided, in situ method based on the time of flight measurement of ultrasonic waves was described. The primary application of this technique was to non-destructively measure the stiffness properties of isotropic and transversely isotropic materials. The method consists of

  2. Detection of an occult hepatocellular carcinoma using ultrasound with liver-specific microbubbles

    International Nuclear Information System (INIS)

    Harvey, Christopher J.; Lim, Adrian K.P.; Blomley, Martin J.K.; Cosgrove, David O.; Taylor-Robinson, Simon D.; Gedroyc, Wladyslaw M.W.

    2002-01-01

    The radiological surveillance of cirrhosis to detect the development of hepatocellular carcinoma (HCC) is problematic because no highly sensitive and specific imaging investigation is available. Ultrasound is typically the first modality used but is less accurate than other imaging modalities. We report the first case of a patient with cirrhosis in whom US imaging with liver-specific microbubbles detected an HCC prior to its detection by MR. The use of liver-specific microbubble US contrast agents is an exciting development in the detection of HCC in chronic liver disease and may help to rectify some of the shortcomings of US. (orig.)

  3. Study of interactions between cells and microbubbles in high speed centrifugation field for biomolecule delivery.

    Science.gov (United States)

    He, Chuan; Chen, Jie

    2014-01-01

    Biomolecule delivery has a very wide range of applications in biology and medicine. In this study, a microbubble based delivery method was developed. In a high centrifugation field, cells deform and collide with microbubbles to induce intracellular pathways on cell membranes. As a result, biomaterials can then easily enter cells. Experimental results show that this delivery method can achieve high delivery efficiency. Simulation results showed that cells with more deformed structure experienced higher strain on cell membranes than cells with less deformed structure. The models can help explain how centrifugation affects cell membrane permeability. By controlling cell morphology and its mechanical properties, high biomolecule delivery efficiency can be achieved.

  4. Ultrasonication and food technology: A review

    Directory of Open Access Journals (Sweden)

    Ishrat Majid

    2015-12-01

    Full Text Available With increasing consumers demand and tightening of food and environmental regulations, traditional food-processing techniques have lost their optimum performance which gave rise to new and powerful technologies. Ultrasonic is a one of the fast, versatile, emerging, and promising non-destructive green technology used in the food industry from last few years. The ultrasound is being carried out in various areas of food technology namely crystallization, freezing, bleaching, degassing, extraction, drying, filtration, emulsification, sterilization, cutting, etc. Ultrasound is being applied as an effective preservation tool in many food-processing fields viz. vegetables and fruits, cereal products, honey, gels, proteins, enzymes, microbial inactivation, cereal technology, water treatment, diary technology, etc. This review summarizes the latest knowledge on impact and application of ultrasound in food technology.

  5. An ultrasonic analysis of the comparative efficiency of various cardiotomy reservoirs and micropore blood filters.

    Science.gov (United States)

    Pearson, D T; Watson, B G; Waterhouse, P S

    1978-01-01

    The ability of 12 commercially available cardiotomy reservoirs to remove bubbles from aspirated blood was investigated by means of a simulated cardiopulmonary bypass circuit and an ultrasonic microbubble detector. Performance varied considerably. The number of gaseous microemboli remaining after passage of blood through the reservoir was reduced by (a) holding the blood in the reservoir, (b) reducing the volume of air mixed with the aspirated blood, and (c) using a reservoir that did not induce turbulence and that contained integral micropore filtration material. Further micropore filtration of the blood after passage through the cardiotomy reservoir was beneficial, and significantly more bubbles were extracted when the microfilter was sited below the reservoir than when it was placed in the arterial line. PMID:684672

  6. Characteristics of phenomenon and sound in microbubble emission boiling

    International Nuclear Information System (INIS)

    Zhu Guangyu; Sun Licheng; Tang Jiguo

    2014-01-01

    Background: Nowadays, the efficient heat transfer technology is required in nuclear energy. Therefore, micro-bubble emission boiling (MEB) is getting more attentions from many researchers due to its extremely high heat-transfer dissipation capability. Purpose: An experimental setup was built up to study the correspondences between the characteristics on the amplitude spectrum of boiling sound in different boiling modes. Methods: The heat element was a copper block heated by four Si-C heaters. The upper of the copper block was a cylinder with the diameter of 10 mm and height of 10 mm. Temperature data were measured by three T-type sheathed thermocouples fitted on the upper of the copper block and recorded by NI acquisition system. The temperature of the heating surface was estimated by extrapolating the temperature distribution. Boiling sound data were acquired by hydrophone and processed by Fourier transform. Bubble behaviors were captured by high-speed video camera with light system. Results: In nucleate boiling region, the boiling was not intensive and as a result, the spectra didn't present any peak. While the MEB fully developed on the heating surface, an obvious peak came into being around the frequency of 300 Hz. This could be explained by analyzing the video data. The periodic expansion and collapse into many extremely small bubbles of the vapor film lead to MEB presenting an obvious characteristic peak in its amplitude spectrum. Conclusion: The boiling mode can be distinguished by its amplitude spectrum. When the MEB fully developed, it presented a characteristic peak in its amplitude spectrum around the frequency between 300-400 Hz. This proved that boiling sound of MEB has a close relation with the behavior of vapor film. (authors)

  7. Destructive hydrogenation. [British patent

    Energy Technology Data Exchange (ETDEWEB)

    1929-07-15

    Liquid or readily liquefiable products are obtained from solid distillable carbonaceous materials such as coals, oil shales or other bituminous substances by subjecting the said initial materials to destructive hydrogenation under mild conditions so that the formation of benzine is substantially avoided, and then subjecting the treated material to extraction by solvents. By hydrogenating under mild conditions the heavy oils which prevent the asphaltic substances from being precipitated are preserved, and the separation of the liquid products from the solid residue is facilitated. Solid paraffins and high boiling point constituents suitable for the production of lubricating oils may be removed before or after the extraction process. The extraction is preferably carried out under pressure with solvents which do not precipitate asphaltic substances. Brown coal containing 11 per cent ash is passed at 450/sup 0/C, and 200 atmospheres pressure in counter current to hydrogen; 40 per cent of the coal is converted into liquid products which are condensed out of the hydrogen stream; the pasty residue, on extraction with benzene, yields 45 per cent of high molecular weight products suitable for the production of lubricating oil.

  8. Innovation in Non Destructive Testing

    NARCIS (Netherlands)

    Wassink, C.H.P.

    2012-01-01

    In many established companies the pace of innovation is low. The Non-Destructive Testing sector is an example of a sector where the pace of innovation is very slow. Non-Destructive Testing (NDT) refers to the set of non-invasive activities used to determine the condition of objects or installations

  9. Pulsed infrared thermography for assessment of ultrasonic welds

    Science.gov (United States)

    McGovern, Megan E.; Rinker, Teresa J.; Sekol, Ryan C.

    2018-03-01

    Battery packs are a critical component in electric vehicles. During pack assembly, the battery cell tab and busbar are ultrasonically welded. The properties of the welds ultimately affect battery pack durability. Quality inspection of these welds is important to ensure durable battery packs. Pack failure is detrimental economically and could also pose a safety hazard, such as thermal runaway. Ultrasonic welds are commonly checked by measuring electrical resistance or auditing using destructive mechanical testing. Resistance measurements are quick, but sensitive to set-up changes. Destructive testing cannot represent the entire weld set. It is possible for a weak weld to satisfy the electrical requirement check, because only sufficient contact between the tabs and busbar is required to yield a low resistance measurement. Laboratory techniques are often not suitable for inline inspection, as they may be time-consuming, use couplant, or are only suitable for coupons. The complex surface geometry also poses difficulties for conventional nondestructive techniques. A method for inspection of ultrasonic welds is proposed using pulsed infrared thermography to identify discrepant welds in a manufacturing environment. Thermal measurements of welds were compared to electrical and mechanical measurements. The heat source distribution was calculated to obtain thermal images with high temporal and spatial resolution. All discrepant welds were readily identifiable using two thermographic techniques: pixel counting and the gradient image. A positive relationship between pixel count and mechanical strength was observed. The results demonstrate the potential of pulsed thermography for inline inspection, which can complement, or even replace, conventional electrical resistance measurements.

  10. Supporting the potential of quantitative ultrasonic techniques for the evaluation of platelet concentration

    Science.gov (United States)

    Villamarín, J. A.; Jiménez, Y. M.; Molano, L. Tatiana; Gutierrez, W. Edgar; Londoño, L. Fernando; Gutierrez, D. A.

    2017-11-01

    This article describes the results obtained by making use of a non-destructive, non-invasive ultrasonic system for the acoustic characterization of bovine plasma rich in platelets using digital signal processing techniques. This study includes computational methods based on acoustic spectrometry estimation and experimental measurements of the speed of sound in blood plasma from different samples analyzed, using an ultrasonic field with resonance frequency of 5 MHz. The results showed that the measurements on ultrasonic signals can contribute to the hematological predictions based on the linear regression model applied to the relationship between experimental ultrasonic parameters calculated and platelet concentration, indicating a growth rate of 1 m/s for each 0.90 x103 platelet per mm3. On the other hand, the attenuation coefficient presented changes of 20% in the platelet concentration using a resolution of 0.057 dB/cm MHz.

  11. Contribution of dynamic focusing to ultrasonic defect characterization

    International Nuclear Information System (INIS)

    Mahaut, S.

    1997-01-01

    Non destructive testing of vessels of pressurized water reactors uses ultrasonic focused transducers, with spherically shaped emitting surface or requiring an acoustic lens. But a mechanically focused transducer has to be used for a given inspection zone and for a fixed control configuration. The aim of this thesis is to improve ultrasonic defect characterization using adaptive dynamic focusing. Such a technique makes use of a ultrasonic defect characterization using adaptive dynamic focusing. Such a technique makes use of an ultrasonic transducer split into an array of individually controlled elements, allowing to apply delay and amplitude laws, calculated from modeling or experimentally deduced. Acoustical characteristics of the ultrasonic beam in the inspected specimen this can be electronically controlled; refraction angle, depth focusing, beam width. We briefly describe in the first chapter a theoretical modeling of the ultrasonic field radiated through a fluid/solid interface, extended to phase array transducers. This model is based on the integral formulation of Rayleigh, modified to take into account transmission through a fluid/solid (homogeneous and isotropic), of planar or cylindrical shape. In the second chapter an experimental study of this technique, with delay and amplitude laws given from the model, is presented, showing the efficiency of this method to adjust the acoustic performances. In he third chapter, experimental delay laws, extracted from the time distribution of signals received by the array (issued from a preliminary detected reflector), are used to provide an optimal imaging of the defect. This self-focusing procedure shows to adapt to a defect without using theoretical delays. The last chapter is dedicated to different applications devoted to improved defect characterization. The first application uses amplitude distribution received by the array, pointing out geometric characteristics of the reflector, while the second application

  12. Ultrasonic calibration assembly

    International Nuclear Information System (INIS)

    1981-01-01

    Ultrasonic transducers for in-service inspection of nuclear reactor vessels have several problems associated with them which this invention seeks to overcome. The first is that of calibration or referencing a zero start point for the vertical axis of transducer movement to locate a weld defect. The second is that of verifying the positioning (vertically or at a predetermined angle). Thirdly there is the problem of ascertaining the speed per unit distance in the operating medium of the transducer beam prior to the actual inspection. The apparatus described is a calibration assembly which includes a fixed, generally spherical body having a surface for reflecting an ultrasonic beam from one of the transducers which can be moved until the reflection from the spherical body is the highest amplitude return signal indicating radial alignment from the body. (U.K.)

  13. A system for personnel qualification of non-destructive testing procedures from testing and and qualification system in Sweden

    International Nuclear Information System (INIS)

    Kuna, M.; Kubis, S.; Plasek, J.

    1999-01-01

    The method for qualification of non-destructive testing personnel carrying out inspections by means of ultrasonic and eddy-current tests to inspect cladding in BWR reactor pressure vessel and core shroud lid. Development of procedures tests with real artificial cracks, blind tests. Evaluation of results by the Swedish Qualification Commission. Performance of the tests at Oskarshamn-1

  14. Pulsed ultrasonic stir welding system

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2013-01-01

    An ultrasonic stir welding system includes a welding head assembly having a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. During a welding operation, ultrasonic pulses are applied to the rod as it rotates about its longitudinal axis. The ultrasonic pulses are applied in such a way that they propagate parallel to the longitudinal axis of the rod.

  15. Further Experiments with Lok-Test and Ultrasonic Test in Relation to Fresh and Hardened Concrete

    DEFF Research Database (Denmark)

    Jensen, Jens Kristian Jehrbo

    Lok-test is mainly a non-destructive pull-out test for determination of concrete strength. The method is deseribed in (l) and it is detailed discussed in theory (2). The method is welknown in practice. Ultrasonic is commonly used for investigations of several materials, especially concrete. In a ....... In a project (3) about non-destructive testing of concrete different methods and the relations to concrete are discussed in theory and practice. This paper point out some interesting results from further experiments in this area.......Lok-test is mainly a non-destructive pull-out test for determination of concrete strength. The method is deseribed in (l) and it is detailed discussed in theory (2). The method is welknown in practice. Ultrasonic is commonly used for investigations of several materials, especially concrete...

  16. Increased epidermal laser fluence through simultaneous ultrasonic microporation

    Science.gov (United States)

    Whiteside, Paul J. D.; Chininis, Jeff A.; Schellenberg, Mason W.; Qian, Chenxi; Hunt, Heather K.

    2016-03-01

    Lasers have demonstrated widespread applicability in clinical dermatology as minimally invasive instruments that achieve photogenerated responses within tissue. However, before reaching its target, the incident light must first transmit through the surface layer of tissue, which is interspersed with chromophores (e.g. melanin) that preferentially absorb the light and may also generate negative tissue responses. These optical absorbers decrease the efficacy of the procedures. In order to ensure that the target receives a clinically relevant dose, most procedures simply increase the incident energy; however, this tends to exacerbate the negative complications of melanin absorption. Here, we present an alternative solution aimed at increasing epidermal energy uence while mitigating excess absorption by unintended targets. Our technique involves the combination of a waveguide-based contact transmission modality with simultaneous high-frequency ultrasonic pulsation, which alters the optical properties of the tissue through the agglomeration of dissolved gasses into micro-bubbles within the tissue. Doing so effectively creates optically transparent pathways for the light to transmit unobstructed through the tissue, resulting in an increase in forward scattering and a decrease in absorption. To demonstrate this, Q-switched nanosecond-pulsed laser light at 532nm was delivered into pig skin samples using custom glass waveguides clad in titanium and silver. Light transmission through the tissue was measured with a photodiode and integrating sphere for tissue with and without continuous ultrasonic pulsation at 510 kHz. The combination of these techniques has the potential to improve the efficiency of laser procedures while mitigating negative tissue effects caused by undesirable absorption.

  17. Splenic abnormalities: a comparative review of ultrasound, microbubble-enhanced ultrasound and computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Peddu, P.; Shah, M.; Sidhu, P.S. E-mail: paul.sidhu@kingsch.nhs.uk

    2004-09-01

    The ultrasound appearances of abnormalities of the spleen are reviewed and images compared with computed tomography. Focal lesions, both benign and malignant, trauma, infarction and congenital abnormalities are presented. The use of microbubble ultrasound contrast media as an aid to identifying and characterizing abnormalities is discussed.

  18. Advances in ultrasound-targeted microbubble-mediated gene therapy for liver fibrosis

    Directory of Open Access Journals (Sweden)

    Cuiyuan Huang

    2017-07-01

    Full Text Available Hepatic fibrosis develops as a wound-healing scar in response to acute and chronic liver inflammation and can lead to cirrhosis in patients with chronic hepatitis B and C. The condition arises due to increased synthesis and reduced degradation of extracellular matrix (ECM and is a common pathological sequela of chronic liver disease. Excessive deposition of ECM in the liver causes liver dysfunction, ascites, and eventually upper gastrointestinal bleeding as well as a series of complications. However, fibrosis can be reversed before developing into cirrhosis and has thus been the subject of extensive researches particularly at the gene level. Currently, therapeutic genes are imported into the damaged liver to delay or prevent the development of liver fibrosis by regulating the expression of exogenous genes. One technique of gene delivery uses ultrasound targeting of microbubbles combined with therapeutic genes where the time and intensity of the ultrasound can control the release process. Ultrasound irradiation of microbubbles in the vicinity of cells changes the permeability of the cell membrane by its cavitation effect and enhances gene transfection. In this paper, recent progress in the field is reviewed with emphasis on the following aspects: the types of ultrasound microbubbles, the construction of an ultrasound-mediated gene delivery system, the mechanism of ultrasound microbubble–mediated gene transfer and the application of ultrasound microbubbles in the treatment of liver fibrosis.

  19. Theranastic USPIO-loaded microbubbles for mediating and monitoring blood-brain barrier permeation

    NARCIS (Netherlands)

    Lammers, Twan Gerardus Gertudis Maria; Koczera, Patrick; Fokong, Stanley; Gremse, Felix; Ehling, Josef; Vogt, Michael; Pich, Andrij; Storm, Gerrit; van Zandvoort, Marc; Kiessling, Fabian

    2015-01-01

    Efficient and safe drug delivery across the blood-brain barrier (BBB) remains one of the major challenges of biomedical and (nano-) pharmaceutical research. Here, it is demonstrated that poly(butyl cyanoacrylate)-based microbubbles (MB), carrying ultrasmall superparamagnetic iron oxide (USPIO)

  20. Theranostic USPIO-loaded microbubbles for mediating and monitoring blood-brain barrier permeation

    NARCIS (Netherlands)

    Lammers, Twan; Koczera, Patrick; Fokong, Stanley; Gremse, Felix; Ehling, Josef; Vogt, Michael; Pich, Andrij; Storm, G; Van Zandvoort, Marc; Kiessling, Fabian

    2015-01-01

    Efficient and safe drug delivery across the blood-brain barrier (BBB) remains one of the major challenges of biomedical and (nano-) pharmaceutical research. Here, it is demonstrated that poly(butyl cyanoacrylate)-based microbubbles (MB), carrying ultrasmall superparamagnetic iron oxide (USPIO)

  1. Decontamination System Development of Radioative Activated Carbon using Micro-bubbles

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Jong seon; Kim, Wi soo [NESS, Daejeon (Korea, Republic of); Han, Byoung sub. [Enesys Co., Daejeon (Korea, Republic of)

    2016-10-15

    This study was aimed to develop a decontamination system by applying such technical characteristics that minimizes a generation of secondary wastes while decontaminating radiation wastes. The radioactive activated carbon is removed from the end-of-life air cleaning filter in replacement or decommission of nuclear power plant or nuclear facility. By removing radioactive activated carbon, the filter would be classified as a low radioactive contaminant. And thus the amount of radioactive wastes and the treatment cost would be decreased. We are in development of the activated carbon cleaning technique by utilizing micro-bubbles, which improve efficiency and minimize damage of activated carbon. The purpose of using micro-bubbles is to decontamination carbon micropore, which is difficult to access, by principle of cavitation phenomenon generated in collapse of micro-bubbles. In this study, we introduced the micro-bubble decontamination system developed to decontaminate activated carbon. For further researches, we will determine carbon weight change and the decontamination rate under the experimental conditions such as temperature and pH.

  2. Decontamination System Development of Radioative Activated Carbon using Micro-bubbles

    International Nuclear Information System (INIS)

    Jeon, Jong seon; Kim, Wi soo; Han, Byoung sub.

    2016-01-01

    This study was aimed to develop a decontamination system by applying such technical characteristics that minimizes a generation of secondary wastes while decontaminating radiation wastes. The radioactive activated carbon is removed from the end-of-life air cleaning filter in replacement or decommission of nuclear power plant or nuclear facility. By removing radioactive activated carbon, the filter would be classified as a low radioactive contaminant. And thus the amount of radioactive wastes and the treatment cost would be decreased. We are in development of the activated carbon cleaning technique by utilizing micro-bubbles, which improve efficiency and minimize damage of activated carbon. The purpose of using micro-bubbles is to decontamination carbon micropore, which is difficult to access, by principle of cavitation phenomenon generated in collapse of micro-bubbles. In this study, we introduced the micro-bubble decontamination system developed to decontaminate activated carbon. For further researches, we will determine carbon weight change and the decontamination rate under the experimental conditions such as temperature and pH

  3. Microbubble signal and trial of org in acute stroke treatment (TOAST) classification in ischemic stroke.

    Science.gov (United States)

    Lee, Chan-Hyuk; Kang, Hyun Goo; Lee, Ji Sung; Ryu, Han Uk; Jeong, Seul-Ki

    2018-07-15

    Right-to-left shunt (RLS) through a patent foramen ovale (PFO) is likely associated with ischemic stroke. Many studies have attempted to demonstrate the association between RLS and ischemic stroke. However, information on the association between the degree of RLS and the subtypes of ischemic stroke categorized by the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification is lacking. This was a retrospective study involving 508 patients with ischemic stroke who underwent a transcranial Doppler (TCD) microbubble test between 2013 and 2015. The degree of RLS was divided into 4 grades according to the microbubble signal (MBS) as follows: no MBS, grade 1; MBS  20, grade 3; curtain sign, grade 4. The degree of RLS and the type of ischemic stroke as classified by TOAST were analyzed and compared with other clinical information and laboratory findings. The higher RLS grade was associated with the cardioembolism (CE) and stroke of undetermined etiology (SUE), and the microbubble signals were inversely related with small vessel disease (SVD). An MBS higher than grade 3 showed a 2.95-fold higher association with SUE than large artery atherosclerosis (LAA), while grade 4 MBS revealed an approximately 8-fold higher association with SUE than LAA. RLS identified by the TCD microbubble test was significantly and independently associated with cryptogenic ischemic stroke (negative evaluation). Subsequent studies are needed to determine the biologic relationship between RLS and ischemic stroke, particularly the cryptogenic subtype of ischemic stroke. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. PBCA-based polymeric microbubbles for molecular imaging and drug delivery

    NARCIS (Netherlands)

    Koczera, Patrick; Appold, Lia; Shi, Yang; Liu, Mengjiao; Dasgupta, Anshuman; Pathak, Vertika; Ojha, Tarun; Fokong, Stanley; Wu, Zhuojun; Van Zandvoort, Marc; Iranzo, Olga; Kuehne, Alexander J C; Pich, Andrij; Kiessling, Fabian; Lammers, Twan

    2017-01-01

    Microbubbles (MB) are routinely used as contrast agents for ultrasound (US) imaging. We describe different types of targeted and drug-loaded poly(n-butyl cyanoacrylate) (PBCA) MB, and demonstrate their suitability for multiple biomedical applications, including molecular US imaging and US-mediated

  5. Image-guided, targeted and triggered drug delivery to tumors using polymer-based microbubbles.

    NARCIS (Netherlands)

    Fokong, S.; Theek, B.; Koczera, P.; Appold, L.; Resch-Genger, U.; van Zandvoort, M.; Storm, Gerrit; Kiessling, F.; Lammers, Twan Gerardus Gertudis Maria

    2012-01-01

    Abstract Microbubbles (MB) are routinely used contrast agents for functional and molecular ultrasound (US) imaging. In addition, they have been attracting more and more attention for drug delivery purposes, enabling e.g. US-mediated drug delivery across biological barriers and US-induced triggered

  6. Magnetic stents retain nanoparticle-bound antirestenotic drugs transported by lipid microbubbles.

    Science.gov (United States)

    Räthel, T; Mannell, H; Pircher, J; Gleich, B; Pohl, U; Krötz, F

    2012-05-01

    Coating coronary stents with antirestenotic drugs revolutionized interventional cardiology. We developed a system for post-hoc drug delivery to uncoated stents. We coupled rapamycin or a chemically similar fluorescent dye to superparamagnetic nanoparticles. The antiproliferative activity of rapamycin coupled to nanoparticles was confirmed in vitro in primary porcine vascular cells. The particles were then incorporated into lipid based microbubbles. Commercially available stents were made magnetizable by nickel plating and used to induce strong field gradients in order to capture magnetic microbubbles from flowing liquids when placed in an external magnetic field. Nanoparticle bound Rapamycin dose dependently inhibited cell proliferation in vitro. Magnetic microcbubbles carrying coated nanoparticles were caught by magnets placed external to a flow-through tube. Plating commercial stents with nickel resulted in increased deposition at stent struts and allowed for widely increased distance of external magnets. Deposition depended on circulation time and velocity and distance of magnets. Deposited microbubbles were destroyed by ultrasound and delivered their cargo to targeted sites. Drugs can be incorporated into nanoparticle loaded microbubbles and thus be delivered to magnetizable stents from circulating fluids by applying external magnetic fields. This technology could allow for post-hoc drug coating of already implanted vascular stents.

  7. Wavelet Spatial Energy Spectrums Studies on Drag Reduction by Micro-bubble Injection

    International Nuclear Information System (INIS)

    Ling Zhen; Yassin Hassan

    2006-01-01

    In this study, continuous wavelet transforms and spatial correlation techniques are employed to determine the space-localized wavenumber energy spectrum of the velocity signals in turbulent channel flow. The flow conditions correspond to single phase flow and micro-bubbles injected two phase flow. The wavelet energy spectrums demonstrate that the wavenumber (eddy size) content of the velocity signals is not only space-dependent but also micro-bubbles can impact the eddy size content. Visual observations of the wavelet energy spectrum spatial distribution was realized by using Particle Image Velocimetry (PIV) measurement technique. The two phase flow condition corresponds to a drag reduction of 38.4% with void fraction of 4.9%. The present results provide evidence that micro-bubbles in the boundary layer of a turbulent channel flow can help adjust the eddy size distributions near the wall. This can assist in explaining that micro-bubbles are performing as buffers to keep the energy of fluid particles going in stream-wise direction and reducing the energy of fluid particles going in normal direction. (authors)

  8. Microbubble-induced detachment of coadhering oral bacteria from salivary pellicles

    NARCIS (Netherlands)

    Sharma, PK; Gibcus, MJ; van der Mei, HC; Busscher, HJ

    The presence and maturity of the salivary pellicle influences microbial adhesion and its tenacity in the oral cavity, posing a challenge to different plaque-control systems. Some plaque-control systems rely on surface-tension forces arising from passing microbubbles sprayed over the pellicle.

  9. Sterilization of microorganisms by the supercritical carbon dioxide micro-bubble method.

    Science.gov (United States)

    Ishikawa, H; Shimoda, M; Shiratsuchi, H; Osajima, Y

    1995-10-01

    Lactobacillus brevis and Saccharomyces cerevisiae were completely sterilized by the supercritical (SC) CO2 micro-bubble method. Gaseous (G) and liquid (LQ) CO2 were used in a similar manner to compare the sterilizing effect. Among the three treatments, the microorganisms were only effectively sterilized by the SC CO2 treatment at 25 MPa and 35 degrees C.

  10. Air-Coupled Low Frequency Ultrasonic Transducers and Arrays with PMN-32%PT Piezoelectric Crystals

    Directory of Open Access Journals (Sweden)

    Rymantas J. Kazys

    2017-01-01

    Full Text Available Air-coupled ultrasonic techniques are being increasingly used for material characterization, non-destructive evaluation of composite materials using guided waves as well as for distance measurements. Application of those techniques is mainly limited by the big losses of ultrasonic signals due to attenuation and mismatch of the acoustic impedances of ultrasonic transducers and air. One of the ways to solve this problem is by application of novel more efficient piezoelectric materials like lead magnesium niobate-lead titanate (PMN-PT type crystals. The objective of this research was the development and investigation of low frequency (<50 kHz wide band air-coupled ultrasonic transducers and arrays with an improved performance using PMN-32%PT crystals. Results of finite element modelling and experimental investigations of the developed transducers and arrays are presented. For improvement of the performance strip-like matching elements made of low acoustic impedance, materials such as polystyrene foams were applied. It allowed to achieve transduction losses for one single element transducer −11.4 dB, what is better than of commercially available air-coupled ultrasonic transducers. Theoretical and experimental investigations of the acoustic fields radiated by the eight element ultrasonic array demonstrated not only a good performance of the array in a pulse mode, but also very good possibilities to electronically focus and steer the ultrasonic beam in space.

  11. Numerical simulation of ultrasonic wave propagation in elastically anisotropic media

    International Nuclear Information System (INIS)

    Jacob, Victoria Cristina Cheade; Jospin, Reinaldo Jacques; Bittencourt, Marcelo de Siqueira Queiroz

    2013-01-01

    The ultrasonic non-destructive testing of components may encounter considerable difficulties to interpret some inspections results mainly in anisotropic crystalline structures. A numerical method for the simulation of elastic wave propagation in homogeneous elastically anisotropic media, based on the general finite element approach, is used to help this interpretation. The successful modeling of elastic field associated with NDE is based on the generation of a realistic pulsed ultrasonic wave, which is launched from a piezoelectric transducer into the material under inspection. The values of elastic constants are great interest information that provide the application of equations analytical models, until small and medium complexity problems through programs of numerical analysis as finite elements and/or boundary elements. The aim of this work is the comparison between the results of numerical solution of an ultrasonic wave, which is obtained from transient excitation pulse that can be specified by either force or displacement variation across the aperture of the transducer, and the results obtained from a experiment that was realized in an aluminum block in the IEN Ultrasonic Laboratory. The wave propagation can be simulated using all the characteristics of the material used in the experiment valuation associated to boundary conditions and from these results, the comparison can be made. (author)

  12. Time reversal for ultrasonic transcranial surgery and echographic imaging

    Science.gov (United States)

    Tanter, Mickael; Aubry, Jean-Francois; Vignon, Francois; Fink, Mathias

    2005-09-01

    High-intensity focused ultrasound (HIFU) is able to induce non-invasively controlled and selective destruction of tissues by focusing ultrasonic beams within organs, analogous to a magnifying glass that concentrates enough sunlight to burn a hole in paper. The brain is an attractive organ in which to perform ultrasonic tissue ablation, but such an application has been hampered by the strong defocusing effect of the skull bone. Our group has been involved in this topic for several years, providing proofs of concept and proposing technological solutions to this problem. Thanks to a high-power time-reversal mirror, presented here are in vivo thermal lesions induced through the skull of 12 sheep. Thermal lesions were confirmed by T2-weighted magnetic resonance post-treatment images and histological examination. These results provide striking evidence that noninvasive ultrasound brain surgery is feasible. A recent approach for high-resolution brain ultrasonic imaging will also be discussed with a skull aberration correction technique based on twin arrays technology. The correction of transcranial ultrasonic images is implemented on a new generation of time-reversal mirrors relying on a fully programmable transmit and receive beamformer.

  13. Ultrasonic Technique for Predicting Grittiness of Salted Duck Egg

    Science.gov (United States)

    Erawan, S.; Budiastra, I. W.; Subrata, I. D. M.

    2018-05-01

    Grittiness of egg yolk is a major factor in consumer acceptance of salted duck egg product. Commonly, the grittiness level is determined by the destructive method. Salted egg industries need a grading system that can judge the grittiness accurately and nondestructively. The purpose of this study was to develop a method for determining grittiness of salted duck eggs nondestructively based on ultrasonic method. This study used 100 samples of salted duck eggs with 7,10,14 and 21 days of salting age. Velocity and attenuation were measured by an ultrasonic system at frequency 50 kHz, followed by physicochemical properties measurement (hardness of egg yolks and salt content), and organoleptic test. Ultrasonic wave velocity in salted duck eggs ranged from 620.6 m/s to 1334.6 m/s, while the coefficient of attenuation value ranged from – 0.76 dB/m to -0.51 dB/m. Yolk hardness was 2.68 N at 7 days to 5.54 N at 21 days of salting age. Salt content was 1.81 % at 7 days to 5.71 % at 21 days of salting age. Highest scores of organoleptic tests on salted duck eggs were 4.23 and 4.18 for 10 and 14 days of salting age, respectively. Discriminant function using ultrasonic velocity variables in minor and major diameter could predict grittiness with 95 % accuracy.

  14. Contribution of expert systems to data processing in non-destructive control

    International Nuclear Information System (INIS)

    Augendre, H.; Perron, M.C.

    1990-01-01

    The increase of non-destructive control in industrial applications requires the development of new data processing methods. The expert system approach is able to provide signal modelling means which are closer to the human behaviour. Such methods used in more traditional programs lead to substantial improvements. These investigations come within our design to apply sophisticated methods to industrial non-destructive control. For defect characterization purposes in ultrasonic control, various supervised learning methods have been investigated in an experimental study. The traditional approach is concerned with statistics based methods, whereas the second one lies in learning logical decision rules valid within a numerical description space [fr

  15. Geophysical Methods for Non-Destructive Testing in Civil Engineering

    Science.gov (United States)

    Niederleithinger, E.

    2013-12-01

    Many non-destructive testing (NDT) methods for civil engineering (e. g. ultrasonics, radar) are similar to geophysical techniques. They just differ in scale, material under investigation and vocabulary used. In spite of the fact that the same principles of physics and mathematics apply to both fields, exchange has been limited in the past. But since a few years more and more geophysical knowledge is used in civil engineering. One of the focal points in research is to improve ultrasonic testing of concrete to be able to image the inside even of large, complex structures and to detect any deterioration as early as possible. One of the main issues is the heterogeneity of concrete, including aggregates, reinforcement, cracks and many other features. Our current research focuses on three points. One is the application of state of the art geophysical migration techniques as Reverse Time Migration (RTM) to image vertical faces or the backside of voids and ducts in thick concrete structures, which isn't possible with conventional techniques used in NDT. Second, we have started to use seismic interferometric techniques to interpolate ultrasonic traces, which can't be measured directly for technical reasons. Third, we are using coda wave interferometry to detect concrete degradation due to load, fatigue, temperature or other influences as early as possible. Practical examples of the application of these techniques are given and potential future research directions will be discussed. It will be shown, how a subset of these techniques can be used for innovative monitoring systems for civil infrastructure. Imaging the interior of a concrete body by ultrasonics and reverse time migration(simulated data).

  16. Wavelength-dependent Faraday–Tyndall effect on laser-induced microbubble in gold colloid

    International Nuclear Information System (INIS)

    Liaw, Jiunn-Woei; Tsai, Shiao-Wen; Lin, Hung-Hsun; Yen, Tzu-Chen; Chen, Bae-Renn

    2012-01-01

    The cavitation microbubbles in dilute gold colloids of different concentrations (2–10 ppm) induced by a focused nanosecond-pulsed laser beam were measured and characterized at different wavelengths by using the passive and active ultrasound measurements. Three colloids with gold nanoparticles (GNPs) of different sizes (10, 45, and 75 nm) were used for experiment. The results show that the lifespan of the microbubble is reduced as the concentration of GNP increases, particularly at the wavelength of 532 nm, the surface plasmon resonance (SPR) of GNP. In contrast, at the off-resonant wavelength (e.g. 700 nm), the lifespan reduction is relatively small. This wavelength-dependent cavitation is attributed to the Faraday–Tyndall effect, a strong light scattering by GNPs. A slight defocusing of the Gaussian beam in gold colloid was proposed. Hence, the waist of the focused beam increases to reduce the optical breakdown in gold colloid. For simplicity, a linear relation between the incremental waist radius of Gaussian beam and the concentration of GNP was assumed. According to this formulation, the theoretical results are consistent with the experimental ones. In addition, the dynamics of the microbubble in gold colloid measured by the active ultrasound method agree with the Rayleigh–Plesset model. -- Highlights: ► The Faraday–Tyndall effect of gold colloid on laser induced microbubble is studied. ► Faraday–Tyndall effect of gold colloid causes the defocusing of laser beam. ► Lifespan of the microbubble is reduced as the concentration of GNP increases. ► Light scattering of laser beam at the surface plasmon resonance of GNP is the maximum.

  17. Non-destructive inservice inspections

    International Nuclear Information System (INIS)

    Kauppinen, P.; Sarkimo, M.; Lahdenperae, K.

    1998-01-01

    In order to assess the possible damages occurring in the components and structures of operating nuclear power plants during service the main components and structures are periodically inspected by non-destructive testing techniques. The reliability of non-destructive testing techniques applied in these inservice inspections is of major importance because the decisions concerning the needs for repair of components are mainly based on the results of inspections. One of the targets of this research program has been to improve the reliability of non-destructive testing. This has been addressed in the sub-projects which are briefly summarised here. (author)

  18. Ultrasonic inspection of AA6013 laser welded joints

    Directory of Open Access Journals (Sweden)

    Adriano Passini

    2011-09-01

    Full Text Available Interest in laser beam welding for aerospace applications is continuously growing, mainly for aluminum alloys. The joints quality is usually assessed by non-destructive inspection (NDI. In this work, bead on plate laser welds on 1.6 mm thick AA6013 alloy sheets, using a 2 kW Yb-fiber laser were obtained and inspected by pulse/echo ultrasonic phased-array technique. Good and poor quality welds were inspected in order to verify the limits of inspection, comparing also to X-ray radiography and metallographic inspections. The results showed that ultrasonic phased array technique was able to identify the presence of grouped porosity, through the attenuation of the amplitude of the echo signal. This attenuation is attributed to the scattering of the waves caused by micro pores, with individual size below the resolution limit of the equipment, but when grouped, can cause a perceptive effect on the reflection spectra.

  19. Italian developments in the ultrasonic examination of pressure vessels

    International Nuclear Information System (INIS)

    Regis, V.

    1987-01-01

    A review of developments being pursued in Italy in ultrasonics for application to pressure vessels is presented. Although nuclear construction in Italy has suffered heavy delays, R and D activities promoted by the Italian Electricity Board in the mid 1970s on advanced UT for non-destructive inspection of thick welded sections made it possible to obtain significant results scored by CISE Laboratories, mainly through the design, construction and qualification of the manual UT spectroscopy and signal processing computerized ARICE system and of the mechanized multifrequency acoustic holography HADIS system. Meanwhile theoretical ultrasonic modelling is actively studied in order to implement software applications and the overall reliability of UT inspections with regard to flaw detection, location and sizing. Selected contributions from manufacturers and service companies with a view to improving UT practice are acknowledged, and still wider technology transfers may be expected in the future, also under ENEA industrial promotion programmes. (author)

  20. Assessment of Aluminum FSW Joints Using Ultrasonic Testing

    Directory of Open Access Journals (Sweden)

    Adamus K.

    2017-12-01

    Full Text Available The paper concerns aluminum joints made using friction stir welding. Although in the aerospace industry there is a tendency to replace metal components with composites, aluminum continues to be a valuable material. Its share in the aircraft structures is the biggest among all structural metals. Lots of aluminum components are made of sheets and most of them require joining. Friction stir welding is a relatively new joining technology, particularly with regard to the sheets having a thickness of 1 mm or lower. The paper is dedicated to non-destructive testing of such joints using ultrasonic inspection. It was found that ultrasonic testing allows for distinguishing between joints without material discontinuities, joint with material discontinuities at the advancing side and joint with discontinuities extending through the whole width of the stir zone. During research only horizontally aligned defects were taken into account.

  1. Questions of qualification exam for non-destructive testing and materials science - the first level

    International Nuclear Information System (INIS)

    Shaaban, H.I.; Addarwish, J.M.A.

    2013-01-01

    The book contains seven chapters: Questions of qualification for magnetic particles testing method - Questions of qualification for liquids penetrant testing method - Questions of qualification for the visual inspection testing method - Questions of qualification for the ultrasonic testing method - Questions of qualification for the eddy current testing method - Questions of rehabilitation for industrial radiographic testing method - Qualification questions about materials science and manufacturing defects of castings and welding and comparison between non-destructive testing methods.

  2. Non-destructive evaluation of welding part of stainless steels by phased array system

    International Nuclear Information System (INIS)

    Tatematsu, Nobuhiro; Matsumoto, Eiji

    2009-01-01

    Recently, more accurate and convenient Non-Destructive Evaluation techniques are required for flaw inspection of structural materials. Phased array ultrasonic transducers are expected as such as NDE technique but there are many subjects to be solved. Furthermore, commercial phased array systems with conventional scanning and imaging techniques have not fulfilled their maximum potential. The purpose of this paper is to improve the phased array system to be applicable to the inhomogeneity evaluation of welding part of stainless steels. (author)

  3. Ultrasonic attenuation in superconducting zinc

    International Nuclear Information System (INIS)

    Auluck, S.

    1978-01-01

    The differences in the Zn ultrasonic attenuation data of different workers are analyzed. The superconducting energy gaps deduced from our analysis of the ultrasonic-attenuation data of Cleavelin and Marshall are consistent with the gaps deduced from the knowledge of the Fermi surface and the electron-phonon mass enhancement factor

  4. Lumber defect detection by ultrasonics

    Science.gov (United States)

    K. A. McDonald

    1978-01-01

    Ultrasonics, the technology of high-frequency sound, has been developed as a viable means for locating most defects In lumber for use in digital form in decision-making computers. Ultrasonics has the potential for locating surface and internal defects in lumber of all species, green or dry, and rough sawn or surfaced.

  5. Ultrasonic inspection of austenitic welds

    International Nuclear Information System (INIS)

    Baikie, B.L.; Wagg, A.R.; Whittle, M.J.; Yapp, D.

    1976-01-01

    The ultrasonic examination of austenitic stainless steel weld metal has always been regarded as a difficult proposition because of the large and variable ultrasonic attenuations and back scattering obtained from apparently similar weld deposits. The work to be described shows how the existence of a fibre texture within each weld deposit (as a result of epitaxial growth through successive weld beads) produces a systematic variation in the ultrasonic attenuation coefficient and the velocity of sound, depending upon the angle between the ultrasonic beam and the fibre axis. Development work has shown that it is possible to adjust the welding parameters to ensure that the crystallographic texture within each weld is compatible with improved ultrasonic transmission. The application of the results to the inspection of a specific weld in type 316 weld metal is described

  6. Ultrasonic variables affecting inspection

    International Nuclear Information System (INIS)

    Lautzenheiser, C.E.; Whiting, A.R.; McElroy, J.T.

    1977-01-01

    There are many variables which affect the detection of the effects and reproducibility of results when utilizing ultrasonic techniques. The most important variable is the procedure, as this document specifies, to a great extent, the controls that are exercised over the other variables. The most important variable is personnel with regards to training, qualification, integrity, data recording, and data analysis. Although the data is very limited, these data indicate that, if the procedure is carefully controlled, reliability of defect detection and reproducibility of results are both approximately 90 percent for reliability of detection, this applies to relatively small defects as reliability increases substantially as defect size increases above the recording limit. (author)

  7. Targeted microbubbles for imaging tumor angiogenesis: assessment of whole-body biodistribution with dynamic micro-PET in mice

    DEFF Research Database (Denmark)

    Willmann, Jürgen K; Cheng, Zhen; Davis, Corrine

    2008-01-01

    To evaluate in vivo whole-body biodistribution of microbubbles (MBs) targeted to tumor angiogenesis-related vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) by using dynamic micro-positron emission tomography (PET) in living mice.......To evaluate in vivo whole-body biodistribution of microbubbles (MBs) targeted to tumor angiogenesis-related vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) by using dynamic micro-positron emission tomography (PET) in living mice....

  8. Quench detection of superconducting magnets using ultrasonic wave

    International Nuclear Information System (INIS)

    Ninomiya, A.; Sakaniwa, K.; Kado, H.; Ishigohka, T.; Higo, Y.

    1989-01-01

    A method to detect a quench of a superconducting magnet using ultrasonic technique is presented. This method is a kind of non-destructive one which monitors a change of acoustic transfer function of a superconducting magnet induced by a local temperature rise or an epoxy crack etc.. Some experiments are carried out on a small epoxy impregnated magnet. The experimental results show that a local temperature rise of about 2-3K can be detected by this method. And, some leading symptoms before quench were detected

  9. Phased array UT (Ultrasonic Testing) used in electricity production plants

    International Nuclear Information System (INIS)

    Kodaira, Takeshi

    2012-01-01

    Phased Array-Ultrasonic testing techniques widely used for detection and quantitative determination of the lattice defects which have been formed from fatigues or stress corrosion cracking in the materials used in the electricity production plants are presented with particular focus on the accurate determination of the defects depth (sizing) and defects discrimination applicable to weld metals of austenite stainless steels and Ni base alloys. The principle of this non-destructive analysis is briefly explained, followed by point and matrix focus phased array methods developed by Mitsubishi Heavy Industries, Ltd are explained rather in detail with illustration and the evaluated results. (S. Ohno)

  10. Enhancement of aerobic biodegradation in an oxygen-limiting environment using a saponin-based microbubble suspension

    International Nuclear Information System (INIS)

    Choi, Yong Ju; Kim, Young-Jin; Nam, Kyoungphile

    2009-01-01

    This study investigated the ability of a saponin-based microbubble suspension to enhance aerobic biodegradation of phenanthrene by subsurface delivery. As the microbubble suspension flowed through a sand column pressure buildup and release was repeatedly observed, which delivered oxygen to the less permeable regions. Burkholderia cepacia RPH1, a phenanthrene-degrading bacterium, was mainly transported in a suspended form in the microbubble suspension. When three pore volumes of the microbubble suspension containing B. cepacia RPH1 was introduced into a column contaminated with phenanthrene (100 mg/kg), the oxygen content declined to 5% from an initial value of 20% within 5 days and correspondingly, 34.4% of initial phenanthrene was removed in 8 days. The addition of two further three pore volumes enhanced the biodegradation efficiency by a factor of 2.2. Our data suggest that a saponin-based microbubble suspension could be a potential carrier for enhancing the aerobic biodegradation under an oxygen-limiting environment. - Microbubble suspension can enhance the phenanthrene biodegradation under an oxygen-limiting condition.

  11. Enhancement of aerobic biodegradation in an oxygen-limiting environment using a saponin-based microbubble suspension

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong Ju; Kim, Young-Jin [Department of Civil and Environmental Engineering, Seoul National University, Shillim-dong, Gwanak-gu, Seoul (Korea, Republic of); Nam, Kyoungphile, E-mail: kpnam@snu.ac.k [Department of Civil and Environmental Engineering, Seoul National University, Shillim-dong, Gwanak-gu, Seoul (Korea, Republic of)

    2009-08-15

    This study investigated the ability of a saponin-based microbubble suspension to enhance aerobic biodegradation of phenanthrene by subsurface delivery. As the microbubble suspension flowed through a sand column pressure buildup and release was repeatedly observed, which delivered oxygen to the less permeable regions. Burkholderia cepacia RPH1, a phenanthrene-degrading bacterium, was mainly transported in a suspended form in the microbubble suspension. When three pore volumes of the microbubble suspension containing B. cepacia RPH1 was introduced into a column contaminated with phenanthrene (100 mg/kg), the oxygen content declined to 5% from an initial value of 20% within 5 days and correspondingly, 34.4% of initial phenanthrene was removed in 8 days. The addition of two further three pore volumes enhanced the biodegradation efficiency by a factor of 2.2. Our data suggest that a saponin-based microbubble suspension could be a potential carrier for enhancing the aerobic biodegradation under an oxygen-limiting environment. - Microbubble suspension can enhance the phenanthrene biodegradation under an oxygen-limiting condition.

  12. Mechanical and dynamic characteristics of encapsulated microbubbles coupled by magnetic nanoparticles as multifunctional imaging and drug delivery agents

    Science.gov (United States)

    Guo, Gepu; Lu, Lu; Yin, Leilei; Tu, Juan; Guo, Xiasheng; Wu, Junru; Xu, Di; Zhang, Dong

    2014-11-01

    Development of magnetic encapsulated microbubble agents that can integrate multiple diagnostic and therapeutic functions is a key focus in both biomedical engineering and nanotechnology and one which will have far-reaching impact on medical diagnosis and therapies. However, properly designing multifunctional agents that can satisfy particular diagnostic/therapeutic requirements has been recognized as rather challenging, because there is a lack of comprehensive understanding of how the integration of magnetic nanoparticles to microbubble encapsulating shells affects their mechanical properties and dynamic performance in ultrasound imaging and drug delivery. Here, a multifunctional imaging contrast and in-situ gene/drug delivery agent was synthesized by coupling super paramagnetic iron oxide nanoparticles (SPIOs) into albumin-shelled microbubbles. Systematical studies were performed to investigate the SPIO-concentration-dependence of microbubble mechanical properties, acoustic scattering response, inertial cavitation activity and ultrasound-facilitated gene transfection effect. These demonstrated that, with the increasing SPIO concentration, the microbubble mean diameter and shell stiffness increased and ultrasound scattering response and inertial cavitation activity could be significantly enhanced. However, an optimized ultrasound-facilitated vascular endothelial growth factor transfection outcome would be achieved by adopting magnetic albumin-shelled microbubbles with an appropriate SPIO concentration of 114.7 µg ml-1. The current results would provide helpful guidance for future development of multifunctional agents and further optimization of their diagnostic/therapeutic performance in clinic.

  13. Mechanical and dynamic characteristics of encapsulated microbubbles coupled by magnetic nanoparticles as multifunctional imaging and drug delivery agents

    International Nuclear Information System (INIS)

    Guo, Gepu; Lu, Lu; Tu, Juan; Guo, Xiasheng; Zhang, Dong; Yin, Leilei; Wu, Junru; Xu, Di

    2014-01-01

    Development of magnetic encapsulated microbubble agents that can integrate multiple diagnostic and therapeutic functions is a key focus in both biomedical engineering and nanotechnology and one which will have far-reaching impact on medical diagnosis and therapies. However, properly designing multifunctional agents that can satisfy particular diagnostic/therapeutic requirements has been recognized as rather challenging, because there is a lack of comprehensive understanding of how the integration of magnetic nanoparticles to microbubble encapsulating shells affects their mechanical properties and dynamic performance in ultrasound imaging and drug delivery. Here, a multifunctional imaging contrast and in-situ gene/drug delivery agent was synthesized by coupling super paramagnetic iron oxide nanoparticles (SPIOs) into albumin-shelled microbubbles. Systematical studies were performed to investigate the SPIO-concentration-dependence of microbubble mechanical properties, acoustic scattering response, inertial cavitation activity and ultrasound-facilitated gene transfection effect. These demonstrated that, with the increasing SPIO concentration, the microbubble mean diameter and shell stiffness increased and ultrasound scattering response and inertial cavitation activity could be significantly enhanced. However, an optimized ultrasound-facilitated vascular endothelial growth factor transfection outcome would be achieved by adopting magnetic albumin-shelled microbubbles with an appropriate SPIO concentration of 114.7 µg ml −1 . The current results would provide helpful guidance for future development of multifunctional agents and further optimization of their diagnostic/therapeutic performance in clinic. (paper)

  14. Lipid microbubbles as a vehicle for targeted drug delivery using focused ultrasound-induced blood-brain barrier opening.

    Science.gov (United States)

    Sierra, Carlos; Acosta, Camilo; Chen, Cherry; Wu, Shih-Ying; Karakatsani, Maria E; Bernal, Manuel; Konofagou, Elisa E

    2017-04-01

    Focused ultrasound in conjunction with lipid microbubbles has fully demonstrated its ability to induce non-invasive, transient, and reversible blood-brain barrier opening. This study was aimed at testing the feasibility of our lipid-coated microbubbles as a vector for targeted drug delivery in the treatment of central nervous system diseases. These microbubbles were labeled with the fluorophore 5-dodecanoylaminfluorescein. Focused ultrasound targeted mouse brains in vivo in the presence of these microbubbles for trans-blood-brain barrier delivery of 5-dodecanoylaminfluorescein. This new approach, compared to previously studies of our group, where fluorescently labeled dextrans and microbubbles were co-administered, represents an appreciable improvement in safety outcome and targeted drug delivery. This novel technique allows the delivery of 5-dodecanoylaminfluorescein at the region of interest unlike the alternative of systemic exposure. 5-dodecanoylaminfluorescein delivery was assessed by ex vivo fluorescence imaging and by in vivo transcranial passive cavitation detection. Stable and inertial cavitation doses were quantified. The cavitation dose thresholds for estimating, a priori, successful targeted drug delivery were, for the first time, identified with inertial cavitation were concluded to be necessary for successful delivery. The findings presented herein indicate the feasibility and safety of the proposed microbubble-based targeted drug delivery and that, if successful, can be predicted by cavitation detection in vivo.

  15. Lipid microbubbles as a vehicle for targeted drug delivery using focused ultrasound-induced blood–brain barrier opening

    Science.gov (United States)

    Sierra, Carlos; Acosta, Camilo; Chen, Cherry; Wu, Shih-Ying; Karakatsani, Maria E; Bernal, Manuel

    2016-01-01

    Focused ultrasound in conjunction with lipid microbubbles has fully demonstrated its ability to induce non-invasive, transient, and reversible blood–brain barrier opening. This study was aimed at testing the feasibility of our lipid-coated microbubbles as a vector for targeted drug delivery in the treatment of central nervous system diseases. These microbubbles were labeled with the fluorophore 5-dodecanoylaminfluorescein. Focused ultrasound targeted mouse brains in vivo in the presence of these microbubbles for trans-blood–brain barrier delivery of 5-dodecanoylaminfluorescein. This new approach, compared to previously studies of our group, where fluorescently labeled dextrans and microbubbles were co-administered, represents an appreciable improvement in safety outcome and targeted drug delivery. This novel technique allows the delivery of 5-dodecanoylaminfluorescein at the region of interest unlike the alternative of systemic exposure. 5-dodecanoylaminfluorescein delivery was assessed by ex vivo fluorescence imaging and by in vivo transcranial passive cavitation detection. Stable and inertial cavitation doses were quantified. The cavitation dose thresholds for estimating, a priori, successful targeted drug delivery were, for the first time, identified with inertial cavitation were concluded to be necessary for successful delivery. The findings presented herein indicate the feasibility and safety of the proposed microbubble-based targeted drug delivery and that, if successful, can be predicted by cavitation detection in vivo. PMID:27278929

  16. Development of ultrasonic heat transfer tube thickness measurement apparatus. Contract research

    Energy Technology Data Exchange (ETDEWEB)

    Ohba, Toshihiro; Katoh, Chiaki; Yanagihara, Takao [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Suetugu, Hidehiko; Yano, Masaya [Sumitomo Chemical Co., Ltd., Tokyo (Japan)

    2003-01-01

    The demonstration test for evaluating reliability of the acid recovery evaporator at Rokkasho Reprocessing Plant has been carried out at JAERI. For the nondestructive measurement of the thickness of heat transfer tubes of the acid recovery evaporator in corrosion test, we have developed thickness measurement apparatus for heat transfer tubes by ultrasonic immersion method with high resolution. The ultrasonic prove in a heat transfer tube can be moved vertically and radially. The results obtained by this apparatus coincident well with those obtained by a destructive method using an optical microscope. (author)

  17. Enhancing Plasma Surface Modification using high Intensity and high Power Ultrasonic Acoustic Waves

    DEFF Research Database (Denmark)

    2010-01-01

    high intensity and high power acoustic waves (102) by at least one ultrasonic high intensity and high power acoustic wave generator (101 ), wherein the ultrasonic acoustic waves are directed to propagate towards said surface (314) of the object (100) so that a laminar boundary layer (313) of a gas...... or a mixture of gases (500) flow in contact with said solid object (100) is thinned or destructed for at least a part of said surface (314). In this way, the plasma can more efficiently access and influence the surface of the solid object to be treated by the plasma, which speeds the process time up...

  18. Advanced ultrasonic inspections

    International Nuclear Information System (INIS)

    Ghia, S.

    1990-08-01

    Acoustic Emission (AE) continuous monitoring and periodical inspections by advanced ultrasonic have been applied to evaluate defect evolution within a PWR reduced scale (1:5) pressure vessel subjected to cyclic mechanical fatigue test. This experimental activity has been carried out in the frame of the Primary Circuit Component Life Prediction programme. In the time period covered by this report actions were performed as following: (1) Ultrasonic examination by multifrequency acoustic holography to evaluate defect evolution subsequently repair and heat treatment of the R2 vessel carried out in March 1988. For the purpose, measurements were performed both at 0 and 200 bar of internal pressure. As uniformity of the procedures adopted, for calibration and testing, made the results comparable with the previous ones no evidence for significant growing of the examined defects has been found. (2) Acoustic emission monitoring has then been carried out during fatigue test from 416000 to 565000 fatigue cycles. Analysis of a large amount of data has been performed paying particular attention to the distinction between friction phenomena and crack growth in order to obtain a correct diagnosis of flaw evolution. The signal duration distribution and the correlation of AE appearance time versus load cycle phase were considered to characterise stick-slip processes. A general intensification of AE activity has been recorded during this last period of monitoring and previous known AE sources were confirmed together with the appearance of new AE sources some of them correlable with real defects

  19. System for ultrasonic examination

    International Nuclear Information System (INIS)

    Lund, S.A.; Kristensen, W.D.

    1987-01-01

    A computerized system for the recording of flaw images by ultrasonic examination according to the pulse-echo method includes at least one ultrasonic probe which can be moved in steps over the surface of an object along a rectilinear scanning path. Digital signals containing information on the successive positions of the sound beam, on echo amplitudes, and on the lengths of sound paths to reflectors inside the object, are processed and used for the accumulated storage of circular patterns of echo amplitude data in a matrix memory associated with a sectional plane through the object. A video screen terminal controls the system and transforms the accumulated data into displays of sectional flaw images of greatly improved precision and sharpness of definition. A gradual transfer of filtered data from a number of parallel sectional planes to three further matrix memories associated with projection planes at right angles to each other permits presentation in three dimensions of equally improved projection flaw images. (author) 2 figs

  20. Effects of ultrasonic disintegration of excess sewage sludge.

    Science.gov (United States)

    Zielewicz, Ewa

    2016-10-01

    Breaking down sludge floc (sonodyspergation effect) and destruction of the cell membranes of microorganisms forming floc is a direct effect of ultrasonic disintegration of sludge excess. This results in release of organic material by liquid sludge (the sonolysis effect). Desired technological effects of the disintegration are: to shorten the hydrolytic phase of fermentation, to increase the production of biogas (source of renewable energy) and an increased mineralization (stability) of fermented sludge. The presented study demonstrates research covering thickened excess sludge of various physicochemical properties, collected from nine municipal sewage treatment plants. The sludge was subjected to ultrasonic disintegration using three differently constructed disintegrators and different proportions of sonification area. Direct effects of disintegration were monitored and recorded using selected indicators describing changes in the properties of sludge and increase of substance dispersed and dissolved in the supernatant liquid to be filtered. Studies have demonstrated that those (direct) effects of ultrasonic disintegration depend on the physicochemical properties of the sludge (foremost the concentration of dry solids) that determine their variable susceptibility to the disintegration methods. The direct effects also depend on optimal process conditions (which consist of the construction of the ultrasonic disintegrator), the geometric proportions of the sonication area and the operating parameters of disintegration (which could be appropriately matched to the characteristics of sludge). The most preferable results were obtained for ultrasonic disintegration of sludge with a dry matter concentration C 0 < 4.2 %. The highest effect of sonolysis-an almost 30-fold increase in the COD dissolved in the supernatant-was obtained for the sludge of lowest dry matter (C 0 = 2.0 %), which was sonicated in a reactor with a short transducer of the largest radiating surface

  1. Influencing factors on microbubble ozonation treatment of acid red 3R wastewater

    Directory of Open Access Journals (Sweden)

    Yurong YA

    2017-08-01

    Full Text Available The microbubble ozonation was used to treat acid red 3R wastewater in order to investigate the influencing factors on its performance. The effects of ozone dose, initial acid red 3R concentration and activated carbon on the performance of microbubble ozonation treatment of acid red 3R wastewater are investigated. The decolorization rate, TOC removal rate, pH variation and ozone utilization efficiency in the microbubble ozonation treatment are compared under different treatment conditions. The results indicate that when increasing ozone dose or decreasing initial acid red 3R concentration, both decolorization rate and TOC removal rate of acid red 3R wastewater increase, but ozone utilization efficiency decreases. The coal-based activated carbon shows strong catalytic activity for microbubble ozonation, which could enhance the decolorization rate and TOC removal rate of acid red 3R wastewater. The better performance of microbubble ozonation treatment is achieved when the ozone dose is 48.3 mg/min and the initial acid red 3R mass concentration is 100 mg/L. Under these conditions, the decolorization efficiency reaches to 100% after treatment for 30 min, the TOC removal efficiency reaches to 78.0% after treatment for 120 min, the reaction rate constant of TOC removal is 0.015 min-1 and the ozone utilization efficiency is higher than 99%. With addition of the coal-based activated carbon of 5 g/L, the decolorization efficiency reaches to 100% after treatment for 15 min, the TOC removal efficiency reaches to 91.2% after treatment for 120 min and the reaction rate constant of TOC removal increases to 0037 min-1.The accumulation and following degradation of intermediate products of small molecule organic acid happens during treatment process, and as a result, the solution pH decreases initially and then increases. Therefore, the optimization of influencing factors for microbubble ozonation could increase both contaminant removal

  2. Non-destructive testing of CFC/Cu joints

    International Nuclear Information System (INIS)

    Casalegno, V.; Ferraris, M.; Salvo, M.; Vesprini, R.; Merola, M.

    2006-01-01

    Reliable non-destructive tests (NDT) are fundamental for the manufacturing of ITER components, especially for high heat flux plasma facing components. NDT include various techniques, which allow inspection of a component without impairing serviceability; it's important to detect and characterize defects (type, size and position) as well as the set-up of acceptance standards in order to predict their influence on the component performance in service conditions. The present study shows a description of NDT used to assess the manufacturing quality of CFC (carbon fibre reinforced carbon matrix composites)/Cu/CuCrZr joints. In the ITER divertor, armor tiles made of CFC are joined to the cooling structure made of precipitation hardened copper alloy CuCrZr; a soft pure Cu interlayer is required between the heat sink and the armour in order to mitigate the stresses at the joint interface. NDT on CFC/Cu joint are difficult because of the different behavior of CFC and copper with regard to physical excitations (e.g. ultrasonic wave) used to test the component; furthermore the response to this input must be accurately studied to identify the detachment of CFC tiles from Cu alloy. The inspected CFC/Cu/CuCrZr joints were obtained through direct casting of pure Cu on modified CFC surface and subsequently through brazing of CFC/Cu joints to CuCrZr by a Cu-based alloy. Different non-destructive methods were used for inspecting these joints: lock-in thermography, ultrasonic inspections, microtomography and microradiography. The NDT tests were followed by metallographic investigation on the samples, since the reliability of a certain non destructive test can be only validated by morphological evidence of the detected defects. This study will undertake a direct comparison of NDT used on CFC/Cu joints in terms of real flaws presence. The purpose of this work is to detect defects at the joining interface as well as in the cast copper ( for instance voids). The experimental work was

  3. Imaging techniques for ultrasonic testing

    International Nuclear Information System (INIS)

    2013-01-01

    These seminar proceedings contain 16 lectures on the following topics: 1. From imaging to quantification - ultrasound methods in medical diagnostics; 2. SAFT, TOFD, Phased Array - classical applications and recent developments in ultrasonic imaging; 3. Innovative ultrasonic imaging methods in research and application; 4. Industrial ultrasonic testing of fibre-reinforced structures of complex geometry; 5. Visualisation of crack tips in the inspection of wheel set shafts with longitudinal boreholes as a means of avoiding unnecessary wheel set changes; 6. Areal analysis of the propagation of Lamb waves on curved, anisotropic structures; 7. High-resolution representation in immersion technique testing; 8. Variants in generating images from phased array measurement data - practical examples involving copper, carbon-fibre reinforced plastic and other materials; 9. GIUM - an unconventional method of microstructure imaging using ultrasonic stimulation and laser vibrometry scanning; 10. Innovative air-ultrasonic testing concepts for improved imaging; 11. Use of imaging methods for improving the quality of test results from nondestructive testing; 12. Modelling and visualisation of EMUS stimulation for transducer optimisation; 13. Use of SAFT in the manufacture of energy conversion machines; 14. Ultrasonic imaging tests for improved defect characterisation during weld seam inspection on longitudinally welded large-diameter pipes; 15. SAFT reconstruction for testing austenitic weld seams and dissimilar metal weld seams for transverse cracks; 16. Imaging-based optimisation method for quantitative ultrasonic testing of anisotropic inhomogeneous austenitic welded joints with determination and utilisation of their elastic properties. One contribution has been abstracted separately. [de

  4. Irradiation Testing of Ultrasonic Transducers

    International Nuclear Information System (INIS)

    Daw, J.; Rempe, J.; Palmer, J.; Tittmann, B.; Reinhardt, B.; Kohse, G.; Ramuhalli, P.; Montgomery, R.; Chien, H.T.; Villard, J.F.

    2013-06-01

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of numerous parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. To address this need, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 10 21 n/cm 2 (E> 0.1 MeV). This test will be an instrumented lead test; and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. By characterizing magnetostrictive and piezoelectric transducer survivability during irradiation, test results will enable the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers. (authors)

  5. Verification of Chemical Weapons Destruction

    International Nuclear Information System (INIS)

    Lodding, J.

    2010-01-01

    The Chemical Weapons Convention is the only multilateral treaty that bans completely an entire category of weapons of mass destruction under international verification arrangements. Possessor States, i.e. those that have chemical weapons stockpiles at the time of becoming party to the CWC, commit to destroying these. All States undertake never to acquire chemical weapons and not to help other States acquire such weapons. The CWC foresees time-bound chemical disarmament. The deadlines for destruction for early entrants to the CWC are provided in the treaty. For late entrants, the Conference of States Parties intervenes to set destruction deadlines. One of the unique features of the CWC is thus the regime for verifying destruction of chemical weapons. But how can you design a system for verification at military sites, while protecting military restricted information? What degree of assurance is considered sufficient in such circumstances? How do you divide the verification costs? How do you deal with production capability and initial declarations of existing stockpiles? The founders of the CWC had to address these and other challenges in designing the treaty. Further refinement of the verification system has followed since the treaty opened for signature in 1993 and since inspection work was initiated following entry-into-force of the treaty in 1997. Most of this work concerns destruction at the two large possessor States, Russia and the United States. Perhaps some of the lessons learned from the OPCW experience may be instructive in a future verification regime for nuclear weapons. (author)

  6. Pulsed ultrasonic stir welding method

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2013-01-01

    A method of performing ultrasonic stir welding uses a welding head assembly to include a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. In the method, the rod is rotated about its longitudinal axis during a welding operation. During the welding operation, a series of on-off ultrasonic pulses are applied to the rod such that they propagate parallel to the rod's longitudinal axis. At least a pulse rate associated with the on-off ultrasonic pulses is controlled.

  7. Fundamentals of ultrasonic phased arrays

    CERN Document Server

    Schmerr, Lester W

    2014-01-01

    This book describes in detail the physical and mathematical foundations of ultrasonic phased array measurements.?The book uses linear systems theory to develop a comprehensive model of the signals and images that can be formed with phased arrays. Engineers working in the field of ultrasonic nondestructive evaluation (NDE) will find in this approach a wealth of information on how to design, optimize and interpret ultrasonic inspections with phased arrays. The fundamentals and models described in the book will also be of significant interest to other fields, including the medical ultrasound and

  8. Fabrication and imaging study of ultrasound/fluorescence bi-modal contrast agent based on polymeric microbubbles

    International Nuclear Information System (INIS)

    Xing Zhanwen; Ke Hengte; Wang Jinrui; Zhao Bo; Qu Enze; Yue Xiuli; Dai Zhifei

    2013-01-01

    Objective: To fabricate an ultrasound/fluorescence bi-modal contrast agent by encapsulating fluorescent quantum dots into polymeric ultrasound contrast agent microbubbles. Methods: Polylactic acid (PLA, 500 mg), (1R)-(+)-camphor (50 mg) and CdSe/ZnS quantum dots (0.5 ml, 2.3 μmol/L)were dissolved or dispersed in dichloromethane (10 ml) to form in an organic phase. Ammonium carbonate solution and poly (vinyl alcohol) solution were employed as the internal and external water phase, respectively. The fluorescent microbubbles were generated using double emulsion solvent evaporation and lyophilization methods. The morphology and illumination were characterized by scanning electron microscopy (SEM) and fluorescence spectrophotometry. Synchronized contrast-enhanced ultrasound and fluorescence imaging was acquired by injecting fluorescent microbubbles into the silicone tube coupled to a self-made ultrasound/fluorescence imaging device. Ultrasound/fluorescence bi-modal in vivo imaging was acquired on the kidney of New Zealand rabbits and suckling mice. Results: The fluorescent microbubbles were hollow spheres with an averaged diameter of (1.62 ± 1.47) μm. More than 99% of these microbubbles were less than 8 μm in diameter, which met the size criteria for ultrasound contrast agents. The fluorescence emission peak of the microbubbles appeared at 632 nm, indicating that good luminescence properties of quantum dots were maintained. In vitro ultrasound/fluorescence imaging showed no echoic signal when the silicone tube was filled with saline, but there was a strong echo when filled with fluorescent microbubbles. The liquid column with fluorescent microbubbles emitted red luminescence under ultraviolet irradiation. The kidney of the rabbit was remarkably enhanced after the administration of fluorescent microbubbles. Bright fluorescence could be observed at the injection site of the suckling mice via subcutaneous injection. Conclusions: A bi-modal but single contrast agent

  9. Microbubbles coupled to methotrexate-loaded liposomes for ultrasound-mediated delivery of methotrexate across the blood–brain barrier

    Directory of Open Access Journals (Sweden)

    Wang X

    2014-10-01

    Full Text Available Xiang Wang,1 Ping Liu,1 Weixiao Yang,1 Lu Li,1 Peijing Li,2 Zheng Liu,1 Zhongxiong Zhuo,1 Yunhua Gao1 1Department of Ultrasound, Xinqiao Hospital of the Third Military Medical University, Chongqing, 2Department of Ultrasound, General Hospital of the Jinan Military Area, Jinan, People’s Republic of China Abstract: Methotrexate (MTX is the single most effective agent for the treatment of primary central nervous system lymphoma. Currently, the delivery of MTX to the brain is achieved by high systemic doses, which cause severe long-term neurotoxicity, or intrathecal administration, which is highly invasive and may lead to infections or hemorrhagic complications. Acoustically active microbubbles have been developed as drug carriers for the noninvasive and brain-targeted delivery of therapeutics. However, their application is limited by their low drug-loading capacity. To overcome this limitation, we prepared microbubbles coupled to MTX-loaded liposomes using ZHIFUXIAN, a novel type of microbubbles with a superior safety profile and long circulation time. MTX-liposome-coupled microbubbles had a high drug-loading capacity of 8.91%±0.86%, and their size (2.64±0.93 µm in diameter was suitable for intravenous injection. When used with ultrasound, they showed more potent in vitro cytotoxicity against Walker-256 cancer cells than MTX alone or MTX-loaded liposomes. When Sprague-Dawley rats were exposed to sonication, administration of these MTX-liposome-coupled microbubbles via the tail vein led to targeted disruption of the blood–brain barrier without noticeable tissue or capillary damage. High-performance liquid chromatography analysis of the brain MTX concentration showed that MTX delivery to the brain followed the order of MTX-liposome-coupled microbubbles + ultrasound (25.3±2.4 µg/g > unmodified ZHIFUXIAN + MTX + ultrasound (18.6±2.2 µg/g > MTX alone (6.97±0.75 µg/g > MTX-liposome-coupled microbubbles (2.92±0.39 µg/g. Therefore

  10. Ultrasonic monitoring on the Electron Beam Welding line at Techmeta during manufacturing of the CMS magnet conductor.

    CERN Multimedia

    Benoit CURE

    2002-01-01

    The ultrasonic non-destructive method allows testing the EBW interface high-strength aluminium alloy / high-purity aluminium. The testing technique implemeted by EMPA is a Phased array system amplitude C-scan with immersion pulse-echo-technique.

  11. Modelling of ultrasonic beam propagation from an array through transversely isotropic fibre reinforced composites using Multi Gaussian beams

    NARCIS (Netherlands)

    Anand, C.; Shroff, S.; Groves, R.M.; Benedictus, R.

    2017-01-01

    Ultrasonic arrays are used for non-destructive evaluation of structures for aerospace and other applications. With the increase in the usage of fibre-reinforced composites in aerospace structures, this evaluation becomes complex due to the effects of attenuation and reflection from the layer

  12. Combining data in non-destructive testing

    International Nuclear Information System (INIS)

    Lavayssiere, B.

    1994-03-01

    Non-destructive testing of some components requires quite often the use of several methods such as X-ray, ultrasonics, Eddy Currents. But the efficiency of a NDT method is highly dependent on the fact that the detectability of flaws in a specimen relies on the choice of the best method. Moreover a lot of inspection issues could benefit from the use of more than one test method, as each NDT method has its own physical properties and technological limits. Some questions still remain: how to combine data, at what level and for what functionality. Simple monomethod processes are well-known now. They include techniques like reconstruction which belongs to the so-called ill-posed problems in the field of mathematics. For NDT data processing, it has the ability to estimate real data from distorted ones coming from a probe. But, up to now there has been very few approaches for computer aided combination of results from different advanced techniques. This report presents the various mathematical fields involved towards that goal (statistical decision theory which allows the use of multiple hypothesis, non-linear decision theory for its capability to classify and to discriminate, graph theory to find the optimal path in an hypothesis graph and also fuzzy logic, multiple resolution analysis, artificial intelligence,...) and which combinations of methods are useful. Some images will illustrate this topic in which EDF is involved, and will explain what are the major goals of this work. Combining is not only an improvement of 3D visualisation which would allow to display simultaneously CAD or NDT data for example, but it consists in exploiting multisensor data collected via a variety of sophisticated techniques and presenting this information to the operator without overloading the operator/system capacities in order to reduce the uncertainty and to resolve the ambiguity inherent to mono method inspection. (author). 7 figs., 35 refs

  13. Cross correlation coefficients of turbulent boundary layer with micro-bubble injection

    International Nuclear Information System (INIS)

    Claudia del Carmen Gutierrez-Torres; Yassin A Hassan; Jose Alfredo Jimenez-Bernal

    2005-01-01

    Full text of publication follows: Injection of micro-bubbles within the turbulent boundary layer has been investigated for a several years as a method to achieve drag reduction. However, the physical mechanism of this phenomenon is not fully understood yet. Experiments in a channel flow for single phase (water) and two phase (water and micro-bubbles) flows under different void fraction conditions are reported for a Reynolds number of 5128. Particle Image Velocimetry technique is used to measure instantaneous velocity fields. Consequently the cross-correlation coefficient Ruv can be calculated along the stream-wise direction for various different y + positions and along the normal direction for the fluctuating components of the velocity obtained from the instantaneous velocity fields. The experiments were carried out in a rectangular acrylic channel, whose dimensions are 4.8 m length, 20.6 cm wide and 5.6 cm height. Water was driven trough the channel by gravity from a tank, which was located 3 m above the channel. Then, water was conducted to a lower tank; from which water was pumped to the upper thank forming a closed loop. Upper tank's water level was kept constant through the tests to ensure constant flow rate trough the channel. The velocity field in the x-y plane was obtained by particle image velocimetry (PIV) at 3.15 m downstream from the channel inlet. A Nd:YAG laser with a wavelength of 532 nm (green light) and power of 350 mJ per pulse is utilized. The particles used for seeding have a diameter that goes from 6-9 μm with a specific gravity almost identical to water s specific gravity. The laser light scattered from the seeding particles was recorded using a CCD Kodak Megaplus camera, Model ES 1.0, 1008 x 1018 pixels. The viewing area was 1.28 cm 2 and was located close to the channel wall. The system recorded 30 velocity fields per second. Each velocity field was obtained from a pair of consecutive images capturing the second image of the pair 1 ms after

  14. Microbubble embedded with upconversion nanoparticles as a bimodal contrast agent for fluorescence and ultrasound imaging

    International Nuclear Information System (INIS)

    Jin, Birui; Lin, Min; You, Minli; Xu, Feng; Lu, Tianjian; Zong, Yujin; Wan, Mingxi; Duan, Zhenfeng

    2015-01-01

    Bimodal imaging offers additional imaging signal thus finds wide spread application in clinical diagnostic imaging. Fluorescence/ultrasound bimodal imaging contrast agent using fluorescent dyes or quantum dots for fluorescence signal has emerged as a promising method, which however requires visible light or UV irradiation resulting in photobleaching, photoblinking, auto-fluorescence and limited tissue penetration depth. To surmount these problems, we developed a novel bimodal contrast agent using layer-by-layer assembly of upconversion nanoparticles onto the surface of microbubbles. The resulting microbubbles with average size of 2 μm provide enhanced ultrasound echo for ultrasound imaging and upconversion emission upon near infrared irradiation for fluorescence imaging. The developed bimodal contrast agent holds great potential to be applied in ultrasound target technique for targeted diseases diagnostics and therapy. (paper)

  15. Cross correlation coefficients of turbulent boundary layer with micro-bubble injection

    Energy Technology Data Exchange (ETDEWEB)

    Claudia del Carmen Gutierrez-Torres [LABINTHAP-SEPI-ESIME, Instituto Politecnico Nacional, U.P. Adolfo Lopez Mateos Edif. 5 3er. Piso, Col Lindavista, C.P. 07738, Mexico, D. F. (Mexico); Yassin A Hassan; Jose Alfredo Jimenez-Bernal [Texas A and M University, College Station, Tx. 77843-3133 (United States)

    2005-07-01

    Full text of publication follows: Injection of micro-bubbles within the turbulent boundary layer has been investigated for a several years as a method to achieve drag reduction. However, the physical mechanism of this phenomenon is not fully understood yet. Experiments in a channel flow for single phase (water) and two phase (water and micro-bubbles) flows under different void fraction conditions are reported for a Reynolds number of 5128. Particle Image Velocimetry technique is used to measure instantaneous velocity fields. Consequently the cross-correlation coefficient Ruv can be calculated along the stream-wise direction for various different y{sup +} positions and along the normal direction for the fluctuating components of the velocity obtained from the instantaneous velocity fields. The experiments were carried out in a rectangular acrylic channel, whose dimensions are 4.8 m length, 20.6 cm wide and 5.6 cm height. Water was driven trough the channel by gravity from a tank, which was located 3 m above the channel. Then, water was conducted to a lower tank; from which water was pumped to the upper thank forming a closed loop. Upper tank's water level was kept constant through the tests to ensure constant flow rate trough the channel. The velocity field in the x-y plane was obtained by particle image velocimetry (PIV) at 3.15 m downstream from the channel inlet. A Nd:YAG laser with a wavelength of 532 nm (green light) and power of 350 mJ per pulse is utilized. The particles used for seeding have a diameter that goes from 6-9 {mu}m with a specific gravity almost identical to water s specific gravity. The laser light scattered from the seeding particles was recorded using a CCD Kodak Megaplus camera, Model ES 1.0, 1008 x 1018 pixels. The viewing area was 1.28 cm{sup 2} and was located close to the channel wall. The system recorded 30 velocity fields per second. Each velocity field was obtained from a pair of consecutive images capturing the second image of

  16. DESTRUCTIVE EDUCATIONAL PRACTICES AT UNIVERSITY

    Directory of Open Access Journals (Sweden)

    Андрей Владимирович Феоктистов

    2013-05-01

    Full Text Available The article is devoted to problems of origin and development of destructive educational practices at university. The authors focus on complex of interactions that disturb the existing in the academic environment norms and ethical principles. The most vivid evidence of destructive educational practice is the corruption issue. On the basis of the analyzed publications dealing with dynamics of corruption in the Russian higher education and the results of the survey by questionnaire, carried out at the technical university, the complex of recommendations has been prepared and suggested that is directed at minimization of destructive behavior at university.DOI: http://dx.doi.org/10.12731/2218-7405-2013-4-28

  17. Computer automation of ultrasonic testing. [inspection of ultrasonic welding

    Science.gov (United States)

    Yee, B. G. W.; Kerlin, E. E.; Gardner, A. H.; Dunmyer, D.; Wells, T. G.; Robinson, A. R.; Kunselman, J. S.; Walker, T. C.

    1974-01-01

    Report describes a prototype computer-automated ultrasonic system developed for the inspection of weldments. This system can be operated in three modes: manual, automatic, and computer-controlled. In the computer-controlled mode, the system will automatically acquire, process, analyze, store, and display ultrasonic inspection data in real-time. Flaw size (in cross-section), location (depth), and type (porosity-like or crack-like) can be automatically discerned and displayed. The results and pertinent parameters are recorded.

  18. Facilitation of Drug Transport across the Blood–Brain Barrier with Ultrasound and Microbubbles

    OpenAIRE

    Meairs, Stephen

    2015-01-01

    Medical treatment options for central nervous system (CNS) diseases are limited due to the inability of most therapeutic agents to penetrate the blood–brain barrier (BBB). Although a variety of approaches have been investigated to open the BBB for facilitation of drug delivery, none has achieved clinical applicability. Mounting evidence suggests that ultrasound in combination with microbubbles might be useful for delivery of drugs to the brain through transient opening of the BBB. This techni...

  19. Effect of low-frequency low-intensity ultrasound with microbubbles on prostate cancer hypoxia.

    Science.gov (United States)

    Hou, Rui; Xu, Yanjun; Lu, Qijie; Zhang, Yang; Hu, Bing

    2017-10-01

    Angiogenesis plays an important role in tumor growth, invasiveness, and metastasis. It is well established that prostate cancer is exposed to fluctuating oxygen tensions and both acute and chronic hypoxia exist, and these conditions can upregulate angiogenesis-associated proteins such as hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A. Low-frequency low-intensity ultrasound with microbubbles can induce obvious microvessel damage in tumors, cause cell necrosis or apoptosis. However, there is no information about whether the blocking blood effect of low-frequency low-intensity ultrasound with microbubbles has an influence on hypoxia environment of prostate cancer. Therefore, we investigated the impact of different low-frequency low-intensity ultrasound with microbubbles radiation times on prostate tumors, observed the change in the hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A protein levels, as well as cell proliferation, apoptosis, and tumor volume. The results indicated that as the radiation was repeated four times on each treatment day, the effects of interruption were durable, the cell proliferation was inhibited, and apoptosis was promoted, and the hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A expression levels were lower in the treatment group than in the control group. When the radiation was carried out once per treatment day, the hypoxia response was stimulated, the hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A expression levels were higher compared with the control group, and cell proliferation was promoted. In addition, the tumor volume increased obviously in the hypoxia-stimulated group, whereas tumors grew slowly in the hypoxia-suppressed group. The results of this work demonstrated that under the same conditions, different radiation times of low-frequency low-intensity ultrasound with microbubbles affect the hypoxia response differently, and the

  20. Regimes of Micro-bubble Formation Using Gas Injection into Ladle Shroud

    Science.gov (United States)

    Chang, Sheng; Cao, Xiangkun; Zou, Zongshu

    2018-06-01

    Gas injection into a ladle shroud is a practical approach to produce micro-bubbles in tundishes, to promote inclusion removal from liquid steel. A semi-empirical model was established to characterize the bubble formation considering the effect of shearing action combined with the non-fully bubble break-up by turbulence. The model shows a good accuracy in predicting the size of bubbles formed in complex flow within the ladle shroud.

  1. Light and ultrasound activated microbubbles around gold nanorods for photoacoustic microsurgery

    Science.gov (United States)

    Cavigli, Lucia; Centi, Sonia; Lai, Sarah; Borri, Claudia; Micheletti, Filippo; Tortoli, Paolo; Panettieri, Ilaria; Streit, Ingolf; Rossi, Francesca; Ratto, Fulvio; Pini, Roberto

    2017-07-01

    Photoacoustic imaging and microsurgery have recently attracted attention for applications in oncology. Here, we present a versatile set-up to trigger vapor microbubbles around plasmonic nanoparticles by a combined light-ultrasound excitation. This system enables the detection and parametrization of bubbles as a function of several variables, such us optical fluence, ultrasound intensity, nanoparticles concentration, thus providing useful directions to the development of new strategies for treatments based on optical cavitation.

  2. Ultrasound-microbubble mediated cavitation of plant cells: effects on morphology and viability.

    Science.gov (United States)

    Qin, Peng; Xu, Lin; Zhong, Wenjing; Yu, Alfred C H

    2012-06-01

    The interaction between ultrasound pulses and microbubbles is known to generate acoustic cavitation that may puncture biological cells. This work presents new experimental findings on the bioeffects of ultrasound-microbubble mediated cavitation in plant cells with emphasis on direct observations of morphological impact and analysis of viability trends in tobacco BY-2 cells that are widely studied in higher plant physiology. The tobacco cell suspensions were exposed to 1 MHz ultrasound pulses in the presence of 1% v/v microbubbles (10% duty cycle; 1 kHz pulse repetition frequency; 70 mm between probe and cells; 1-min exposure time). Few bioeffects were observed at low peak negative pressures (cavitation presumably occurred. In contrast, at 0.9 MPa peak negative pressure (with more inertial cavitation activities according to our passive cavitation detection results), random pores were found on tobacco cell wall (observed via scanning electron microscopy) and enhanced exogenous uptake into the cytoplasm was evident (noted in our fluorescein isothiocyanate dextran uptake analysis). Also, instant lysis was observed in 23.4% of cells (found using trypan blue staining) and programmed cell death was seen in 23.3% of population after 12 h (determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling [TUNEL]). These bioeffects generally correspond in trend with those for mammalian cells. This raises the possibility of developing ultrasound-microbubble mediated cavitation into a targeted gene transfection paradigm for plant cells and, conversely, adopting plant cells as experimental test-beds for sonoporation-based gene therapy in mammalian cells. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  3. Apparatus for ultrasonic nebulization

    International Nuclear Information System (INIS)

    Olson, K.W.; Haas, W.J. Jr.; Fassel, V.A.

    1978-01-01

    An improved apparatus is described for ultrasonic nebulization of liquid samples or suspensions in which the piezoelectric transducer is protected from chemical attack and erosion. The transducer is protected by being bonded to the inner surface of a glass plate which forms one end wall of a first hollow body provided with apparatus for circulating a fluid for cooling and stabilizing the transducer. The glass plate, which is one-half wavelength in thickness to provide an acoustically coupled outer nebulizing surface, seals an opening in a second hollow body which encloses an aerosol mixing chamber. The second body includes apparatus for delivering the sample solution to the nebulizing surface, a gas inlet for providing a flow of carrier gas for transporting the aerosol of the nebulized sample and an aerosol outlet

  4. High resolution ultrasonic densitometer

    International Nuclear Information System (INIS)

    Dress, W.B.

    1983-01-01

    The velocity of torsional stress pulses in an ultrasonic waveguide of non-circular cross section is affected by the temperature and density of the surrounding medium. Measurement of the transit times of acoustic echoes from the ends of a sensor section are interpreted as level, density, and temperature of the fluid environment surrounding that section. This paper examines methods of making these measurements to obtain high resolution, temperature-corrected absolute and relative density and level determinations of the fluid. Possible applications include on-line process monitoring, a hand-held density probe for battery charge state indication, and precise inventory control for such diverse fluids as uranium salt solutions in accountability storage and gasoline in service station storage tanks

  5. Grain destruction in interstellar shocks

    International Nuclear Information System (INIS)

    Seab, C.G.; Shull, J.M.

    1984-01-01

    One of the principal methods for removing grains from the Interstellar Medium is to destroy them in shock waves. Previous theoretical studies of shock destruction have generally assumed only a single size and type of grain; most do not account for the effect of the grain destruction on the structure of the shock. Earlier calculations have been improved in three ways: first, by using a ''complete'' grain model including a distribution of sizes and types of grains; second, by using a self-consistent shock structure that incorporates the changing elemental depletions as the grains are destroyed; and third, by calculating the shock-processed ultraviolet extinction curves for comparison with observations. (author)

  6. The destruction of organic matter

    CERN Document Server

    Gorsuch, T T

    1970-01-01

    International Series of Monographs in Analytical Chemistry, Volume 39: The Destruction of Organic Matter focuses on the identification of trace elements in organic compounds. The monograph first offers information on the processes involved in the determination of trace elements in organic matters, as well as the methods not involving complete destruction of these elements. The text surveys the sources of errors in the processes responsible in pinpointing elements in organic compounds. These processes include sampling, disruption of the samples, manipulation, and measurements. The book

  7. Facilitation of Drug Transport across the Blood–Brain Barrier with Ultrasound and Microbubbles

    Directory of Open Access Journals (Sweden)

    Stephen Meairs

    2015-08-01

    Full Text Available Medical treatment options for central nervous system (CNS diseases are limited due to the inability of most therapeutic agents to penetrate the blood–brain barrier (BBB. Although a variety of approaches have been investigated to open the BBB for facilitation of drug delivery, none has achieved clinical applicability. Mounting evidence suggests that ultrasound in combination with microbubbles might be useful for delivery of drugs to the brain through transient opening of the BBB. This technique offers a unique non-invasive avenue to deliver a wide range of drugs to the brain and promises to provide treatments for CNS disorders with the advantage of being able to target specific brain regions without unnecessary drug exposure. If this method could be applied for a range of different drugs, new CNS therapeutic strategies could emerge at an accelerated pace that is not currently possible in the field of drug discovery and development. This article reviews both the merits and potential risks of this new approach. It assesses methods used to verify disruption of the BBB with MRI and examines the results of studies aimed at elucidating the mechanisms of opening the BBB with ultrasound and microbubbles. Possible interactions of this novel delivery method with brain disease, as well as safety aspects of BBB disruption with ultrasound and microbubbles are addressed. Initial translational research for treatment of brain tumors and Alzheimer’s disease is presented.

  8. Facilitation of Drug Transport across the Blood-Brain Barrier with Ultrasound and Microbubbles.

    Science.gov (United States)

    Meairs, Stephen

    2015-08-31

    Medical treatment options for central nervous system (CNS) diseases are limited due to the inability of most therapeutic agents to penetrate the blood-brain barrier (BBB). Although a variety of approaches have been investigated to open the BBB for facilitation of drug delivery, none has achieved clinical applicability. Mounting evidence suggests that ultrasound in combination with microbubbles might be useful for delivery of drugs to the brain through transient opening of the BBB. This technique offers a unique non-invasive avenue to deliver a wide range of drugs to the brain and promises to provide treatments for CNS disorders with the advantage of being able to target specific brain regions without unnecessary drug exposure. If this method could be applied for a range of different drugs, new CNS therapeutic strategies could emerge at an accelerated pace that is not currently possible in the field of drug discovery and development. This article reviews both the merits and potential risks of this new approach. It assesses methods used to verify disruption of the BBB with MRI and examines the results of studies aimed at elucidating the mechanisms of opening the BBB with ultrasound and microbubbles. Possible interactions of this novel delivery method with brain disease, as well as safety aspects of BBB disruption with ultrasound and microbubbles are addressed. Initial translational research for treatment of brain tumors and Alzheimer's disease is presented.

  9. Preparation of monodisperse microbubbles using an integrated embedded capillary T-junction with electrohydrodynamic focusing.

    Science.gov (United States)

    Parhizkar, Maryam; Stride, Eleanor; Edirisinghe, Mohan

    2014-07-21

    This work investigates the generation of monodisperse microbubbles using a microfluidic setup combined with electrohydrodynamic processing. A basic T-junction microfluidic device was modified by applying an electrical potential difference across the outlet channel. A model glycerol air system was selected for the experiments. In order to investigate the influence of the electric field strength on bubble formation, the applied voltage was increased systematically up to 21 kV. The effect of solution viscosity and electrical conductivity was also investigated. It was found that with increasing electrical potential difference, the size of the microbubbles reduced to ~25% of the capillary diameter whilst their size distribution remained narrow (polydispersity index ~1%). A critical value of 12 kV was found above which no further significant reduction in the size of the microbubbles was observed. The findings suggest that the size of the bubbles formed in the T-junction (i.e. in the absence of the electric field) is strongly influenced by the viscosity of the solution. The eventual size of bubbles produced by the composite device, however, was only weakly dependent upon viscosity. Further experiments, in which the solution electrical conductivity was varied by the addition of a salt indicated that this had a much stronger influence upon bubble size.

  10. Drug perfusion enhancement in tissue model by steady streaming induced by oscillating microbubbles.

    Science.gov (United States)

    Oh, Jin Sun; Kwon, Yong Seok; Lee, Kyung Ho; Jeong, Woowon; Chung, Sang Kug; Rhee, Kyehan

    2014-01-01

    Drug delivery into neurological tissue is challenging because of the low tissue permeability. Ultrasound incorporating microbubbles has been applied to enhance drug delivery into these tissues, but the effects of a streaming flow by microbubble oscillation on drug perfusion have not been elucidated. In order to clarify the physical effects of steady streaming on drug delivery, an experimental study on dye perfusion into a tissue model was performed using microbubbles excited by acoustic waves. The surface concentration and penetration length of the drug were increased by 12% and 13%, respectively, with streaming flow. The mass of dye perfused into a tissue phantom for 30s was increased by about 20% in the phantom with oscillating bubbles. A computational model that considers fluid structure interaction for streaming flow fields induced by oscillating bubbles was developed, and mass transfer of the drug into the porous tissue model was analyzed. The computed flow fields agreed with the theoretical solutions, and the dye concentration distribution in the tissue agreed well with the experimental data. The computational results showed that steady streaming with a streaming velocity of a few millimeters per second promotes mass transfer into a tissue. © 2013 Published by Elsevier Ltd.

  11. Acoustic microstreaming due to an ultrasound contrast microbubble near a wall

    Science.gov (United States)

    Mobadersany, Nima; Sarkar, Kausik

    2017-11-01

    In an ultrasound field, in addition to the sinusoidal motion of fluid particles, particles experience a steady streaming velocity due to nonlinear second order effects. Here, we have simulated the microstreaming flow near a plane rigid wall caused by the pulsations of contrast microbubbles. Although these microbubbles were initially developed as a contrast enhancing agents for ultrasound imaging, they generate additional therapeutic effects that can be harnessed for targeted drug delivery or blood brain barrier (BBB) opening. The microbubbles have a gas core coated with a stabilizing layer of lipids or proteins. We use analytical models as well as boundary element (BEM) simulation to simulate the flow around these bubbles implementing interfacial rheology models for the coating. The microstreaming flow is characterized by two wall bounded vortices. The size of the vortices decreases with the decrease of the separation from the wall. The vortex-induced shear stress is simulated and analyzed as a function of excitation parameters and geometry. These microstreaming shear stress plays a critical role in increasing the membrane permeability facilitating drug delivery or rupturing biological tissues.

  12. Optimization and characterization of stable lipid-based, oxygen-filled microbubbles by mixture design.

    Science.gov (United States)

    Polizzotti, Brian D; Thomson, Lindsay M; O'Connell, Daniel W; McGowan, Francis X; Kheir, John N

    2014-08-01

    Tissue hypoxia is a final common pathway that leads to cellular injury and death in a number of critical illnesses. Intravenous injections of self-assembling, lipid-based oxygen microbubbles (LOMs) can be used to deliver oxygen gas, preventing organ injury and death from systemic hypoxemia. However, current formulations exhibit high polydispersity indices (which may lead to microvascular obstruction) and poor shelf-lives, limiting the translational capacity of LOMs. In this study, we report our efforts to optimize LOM formulations using a mixture response surface methodology (mRSM). We study the effect of changing excipient proportions (the independent variables) on microbubble diameter and product loss (the dependent variables). By using mRSM analysis, the experimental data were fit using a reduced Scheffé linear mixture model. We demonstrate that formulations manufactured from 1,2-distearoyl-sn-glycero-3-phosphocholine, corn syrup, and water produce micron-sized microbubbles with low polydispersity indices, and decreased product loss (relative to previously described formulations) when stored at room temperature over a 30-day period. Optimized LOMs were subsequently tested for their oxygen-releasing ability and found to have similar release kinetics as prior formulations. © 2014 Wiley Periodicals, Inc.

  13. Quantitation of MRI sensitivity to quasi-monodisperse microbubble contrast agents for spatially resolved manometry.

    Science.gov (United States)

    Bencsik, Martin; Al-Rwaili, Amgad; Morris, Robert; Fairhurst, David J; Mundell, Victoria; Cave, Gareth; McKendry, Jonathan; Evans, Stephen

    2013-11-01

    The direct in-vivo measurement of fluid pressure cannot be achieved with MRI unless it is done with the contribution of a contrast agent. No such contrast agents are currently available commercially, whilst those demonstrated previously only produced qualitative results due to their broad size distribution. Our aim is to quantitate then model the MR sensitivity to the presence of quasi-monodisperse microbubble populations. Lipid stabilised microbubble populations with mean radius 1.2 ± 0.8 μm have been produced by mechanical agitation. Contrast agents with increasing volume fraction of bubbles up to 4% were formed and the contribution the bubbles bring to the relaxation rate was quantitated. A periodic pressure change was also continuously applied to the same contrast agent, until MR signal changes were only due to bubble radius change and not due to a change in bubble density. The MR data compared favourably with the prediction of an improved numerical simulation. An excellent MR sensitivity of 23 % bar(-1) has been demonstrated. This work opens up the possibility of generating microbubble preparations tailored to specific applications with optimised MR sensitivity, in particular MRI based in-vivo manometry. Copyright © 2012 Wiley Periodicals, Inc.

  14. Ablation of benign prostatic hyperplasia using microbubble-mediated ultrasound cavitation.

    Science.gov (United States)

    Li, Tao; Liu, Zheng

    2010-04-01

    Benign prostatic hyperplasia (BPH) is a world-wide common disease in elderly male patients. A number of invasive physiotherapies have been used to replace prostatectomy. In this article we report our hypothesis of using microbubbles-mediated ultrasound cavitation effects to ablate prostatic tissues. Microbubble ultrasound contrast agent is widely used contrast media in ultrasonography, yet it is also found to act as cavitation nuclei or enhancer. Once excited by a high peak pressure ultrasound pulse, the mechanical effects, like shock wave and microstream, released from cavitation could produce a series of bioeffects, contributing to sonoporation, microvascular rupture and hematoma. BPH is known to have hyperplastic neovasculature and this make it possible to be disrupted by the physical effects of cavitation under existing microbubbles in circulation. Mechanical ablation of prostatic capillary or small vessels could result in pathological alterations such as thrombosis, micro-circulation blockage, prostatic necrosis and atrophia. Thereupon it could effectively treat BPH by nontraumatic ways. (c) 2009 Elsevier Ltd. All rights reserved.

  15. Spatiotemporal evolution of cavitation dynamics exhibited by flowing microbubbles during ultrasound exposure.

    Science.gov (United States)

    Choi, James J; Coussios, Constantin-C

    2012-11-01

    Ultrasound and microbubble-based therapies utilize cavitation to generate bioeffects, yet cavitation dynamics during individual pulses and across consecutive pulses remain poorly understood under physiologically relevant flow conditions. SonoVue(®) microbubbles were made to flow (fluid velocity: 10-40 mm/s) through a vessel in a tissue-mimicking material and were exposed to ultrasound [frequency: 0.5 MHz, peak-rarefactional pressure (PRP): 150-1200 kPa, pulse length: 1-100,000 cycles, pulse repetition frequency (PRF): 1-50 Hz, number of pulses: 10-250]. Radiated emissions were captured on a linear array, and passive acoustic mapping was used to spatiotemporally resolve cavitation events. At low PRPs, stable cavitation was maintained throughout several pulses, thus generating a steady rise in energy with low upstream spatial bias within the focal volume. At high PRPs, inertial cavitation was concentrated in the first 6.3 ± 1.3 ms of a pulse, followed by an energy reduction and high upstream bias. Multiple pulses at PRFs below a flow-dependent critical rate (PRF(crit)) produced predictable and consistent cavitation dynamics. Above the PRF(crit), energy generated was unpredictable and spatially biased. In conclusion, key parameters in microbubble-seeded flow conditions were matched with specific types, magnitudes, distributions, and durations of cavitation; this may help in understanding empirically observed in vivo phenomena and guide future pulse sequence designs.

  16. Ultrasonic Technology in Duress Alarms.

    Science.gov (United States)

    Lee, Martha A.

    2000-01-01

    Provides the pros and cons of the most commonly used technologies in personal duress alarm systems in the school environment. Discussed are radio frequency devices, infrared systems, and ultrasonic technology. (GR)

  17. Ultrasonic extensometer measures bolt preload

    Science.gov (United States)

    Daniels, C. M., Jr.

    1978-01-01

    Extensometer using ultrasonic pulse reflections to measure elongations in tightened belts and studs is much more accurate than conventional torque wrenches in application of specified preload to bolts and other threaded fasteners.

  18. Models on reliability of non-destructive testing

    International Nuclear Information System (INIS)

    Simola, K.; Pulkkinen, U.

    1998-01-01

    The reliability of ultrasonic inspections has been studied in e.g. international PISC (Programme for the Inspection of Steel Components) exercises. These exercises have produced a large amount of information on the effect of various factors on the reliability of inspections. The information obtained from reliability experiments are used to model the dependency of flaw detection probability on various factors and to evaluate the performance of inspection equipment, including the sizing accuracy. The information from experiments is utilised in a most effective way when mathematical models are applied. Here, some statistical models for reliability of non-destructive tests are introduced. In order to demonstrate the use of inspection reliability models, they have been applied to the inspection results of intergranular stress corrosion cracking (IGSCC) type flaws in PISC III exercise (PISC 1995). The models are applied to both flaw detection frequency data of all inspection teams and to flaw sizing data of one participating team. (author)

  19. Data fusion: a new concept in non-destructive testing

    International Nuclear Information System (INIS)

    Georgel, B.; Lavayssiere, B.

    1995-01-01

    Non-destructive testing of some components (made of austenitic steel, or of a complex shape for example) requires quite often the use of several methods such as X-ray, ultrasonics, Eddy Currents. Then, a skilled operator is able to perform the expertise of the specimen. The main goal of this paper is to show that 3D diagnosis may be improved in term of reliability and precision by fusion of several NDT techniques. A data fusion algorithm is more that trying to improve the visualisation or the rendering of NDT data sets. It consists for each volume element, in computing a new value representing the combined information and in formulating a diagnosis on this basis. To achieve such a goal, know-how in modeling of physical phenomena and in applied mathematics is crucial. (authors). 4 refs., 2 figs

  20. Catalogue of test specimens for non-destructive examination

    International Nuclear Information System (INIS)

    1985-05-01

    One of the key elements in assuring the integrity of reactor primary circuits is the availability of trustworthy non-destructive methods for detecting dangerous defects that may be present. Various approaches to making such examinations are being developed, including the use of ultrasonic and radiographic techniques. To demonstrate their capability and reliability, they must be tested on steel specimens reproducing the various types of faults which may arise in real primary circuit vessels and piping. Such specimens are costly to fabricate. It is therefore clearly desirable that existing specimens should be made accessible to as many organisations as possible for testing. This catalogue contains detailed Information on forty-odd deliberately flawed plates, blocks, vessels, etc. which have been produced in OECD countries, along with the name of a contact person to whom inquiries should be directed in each case

  1. New technologies in electromagnetic non-destructive testing

    CERN Document Server

    Huang, Songling

    2016-01-01

    This book introduces novel developments in the field of electromagnetic non-destructive testing and evaluation (NDT/E). The topics include electromagnetic ultrasonic guided wave testing, pulsed eddy current testing, remote field eddy current testing, low frequency eddy current testing, metal magnetic memory testing, and magnetic flux leakage testing. Considering the increasing concern about the safety maintenance of critical structures in various industries and everyday life, these topics presented here will be of particular interest to the readers in the NDT/E field. This book covers both theoretical researches and the engineering applications of the electromagnetic NDT technology. It could serve as a valuable reference for college students and relevant NDT technicians. It is also a useful material for qualification training and higher learning for nondestructive testing professionals.

  2. Molecular evaluation of thrombosis using X-ray phase contrast imaging with microbubbles targeted to P-selectin in mice

    International Nuclear Information System (INIS)

    Tang, Rongbiao; Chai, Wei-Min; Yan, Fuhua; Chen, Ke-Min; Yang, Guo-Yuan

    2016-01-01

    X-ray phase contrast imaging (PCI) provides excellent image contrast by utilizing the phase shift. The introduction of microbubbles into tissues can cause a phase shift to make microbubbles visibly identified on PCI. In this study, we assessed the feasibility of targeted microbubble-based PCI for the detection of thrombosis. The absorption and phase contrast images of P-selectin-targeted microbubbles (MB P ) were obtained and compared in vitro. MB P , control IgG-targeted microbubbles (MB C ), and unbound microbubbles (MB U ) were tested for binding specificity on thrombi expressing P-selectin. MB P were used as molecular PCI probes to evaluate P-selectin expression in a mouse model of arteriovenous shunt thrombosis that was created using PE tubes in the bypass outside of the mouse body. PCI clearly showed the microbubbles not viewable via absorption contrast imaging (ACI). In vitro attachment of MB P (91.60 ± 11.63) to thrombi was significantly higher than attachment of MB C (17.80 ± 4.02, P < 0.001) or MB U (9.80 ± 2.59, P < 0.001). In the mouse model of arteriovenous shunt thrombosis, the binding affinity of MB P (15.50 ± 6.25) was significantly greater than that of MB C (0.50 ± 0.84, P < 0.001) or MB U (0.33 ± 0.52, P < 0.001). Our results indicate that molecular PCI may be considered as a novel and promising imaging modality for the investigation of thrombosis. (orig.)

  3. Non-Destructive Inspection Lab (NDI)

    Data.gov (United States)

    Federal Laboratory Consortium — The NDI specializes in applied research, development and performance of nondestructive inspection procedures (flourescent penetrant, magnetic particle, ultrasonics,...

  4. Ultrasonic characterization of defective porcelain tiles

    Directory of Open Access Journals (Sweden)

    Eren, E.

    2012-08-01

    Full Text Available The aim of this work is the optimization of ultrasonic methods in the non-destructive testing of sintered porcelain tiles containing defects. For this reason, a silicon nitride ball, carbon black and PMMA (Polymethylmethacrylate were imbedded in porcelain tile granules before pressing to make special defects in tiles. After sintering at 1220ºC, the time of flight of the ultrasonic waves and ultrasonic signal amplitudes through the sintered porcelain tiles were measured by a contact ultrasonic transducer operating on pulse-echo mode. This method can allow for defect detection using the A-scan. The results of the test showed that the amplitude of the received peak for a defective part is smaller than for a part which has no defects. Depending on the size, shape and position of the defect, its peak can be detected. Additionally, an immersion pulse-echo C-scan method was also used to differentiate between defects in porcelain tiles. By using this technique, it is possible to determine the place and shape of defects. To support the results of the ultrasonic investigation, a SEM characterization was also made.

    El fin principal de este trabajo es la optimización de métodos ultrasónicos en la prueba no destructiva de azulejos sinterizados de porcelana que contienen defectos. Por lo tanto, bolas del nitruro de silicio, negros de carbón y PMMA (polimetilmetacrilato fueron encajados en gránulos del azulejo de porcelana antes de presionar para hacer defectos especiales en azulejos. Después de sinterizado en 1220ºC, el tiempo de vuelo de las ondas ultrasónicas fue medido a través del azulejo sinterizado de la porcelana. El tiempo del vuelo de ondas ultrasónicas fue medido por un transductor de contacto ultrasónico operando en modo eco-pulso. Este método puede permitir la detección de defectos usando escaneo-A. Los resultados de la prueba demostraron que la amplitud del pico recibido por partes defectuosas es más pequeño que la parte

  5. Guided ultrasonic wave beam skew in silicon wafers

    Science.gov (United States)

    Pizzolato, Marco; Masserey, Bernard; Robyr, Jean-Luc; Fromme, Paul

    2018-04-01

    In the photovoltaic industry, monocrystalline silicon wafers are employed for solar cells with high conversion efficiency. Micro-cracks induced by the cutting process in the thin wafers can lead to brittle wafer fracture. Guided ultrasonic waves would offer an efficient methodology for the in-process non-destructive testing of wafers to assess micro-crack density. The material anisotropy of the monocrystalline silicon leads to variations of the guided wave characteristics, depending on the propagation direction relative to the crystal orientation. Selective guided ultrasonic wave excitation was achieved using a contact piezoelectric transducer with custom-made wedges for the A0 and S0 Lamb wave modes and a transducer holder to achieve controlled contact pressure and orientation. The out-of-plane component of the guided wave propagation was measured using a non-contact laser interferometer. The phase slowness (velocity) of the two fundamental Lamb wave modes was measured experimentally for varying propagation directions relative to the crystal orientation and found to match theoretical predictions. Significant wave beam skew was observed experimentally, especially for the S0 mode, and investigated from 3D finite element simulations. Good agreement was found with the theoretical predictions based on nominal material properties of the silicon wafer. The important contribution of guided wave beam skewing effects for the non-destructive testing of silicon wafers was demonstrated.

  6. Conceptualizing Chronic Self-Destructiveness.

    Science.gov (United States)

    Kelley, Kathryn

    Self-destructiveness can be viewed in two ways: as performing an act which one knows cognitively is not conducive to one's welfare but nonetheless leads to some pleasurable affect (e.g., overeating, smoking); or not performing an act one knows one should perform but which has some negative affective consequences (e.g., dental checkups, saving…

  7. Animal Spirits Meets Creative Destruction

    NARCIS (Netherlands)

    Francois, P.; Lloyd-Ellis, H.

    2001-01-01

    We show how a Schumpeterian process of creative destruction can induce coordination in the timing of entrepreneurial activities across diverse sectors of the economy.Consequently, a multi-sector economy, in which sector-specific, productivity improvements are made by independent, profit-seeking

  8. Dynamic Scoring Through Creative Destruction

    NARCIS (Netherlands)

    van Oudheusden, P.

    2012-01-01

    Abstract: We examine the dynamic feedback effects of fiscal policies on the government budget and economy activity in a calibrated general equilibrium framework featuring endogenous growth through creative destruction. For several European countries, we find that making tax incentives with respect

  9. Exergy destruction in ammonia scrubbers

    NARCIS (Netherlands)

    Zisopoulos, Filippos K.; Goot, van der Atze Jan; Boom, Remko M.

    2018-01-01

    A theoretical ammonia scrubbing process by sulfuric acid solution is assessed with the concept of exergy. The exergy destruction of chemical neutralization is mainly (75–94%) due to changes in the chemical exergy of streams and thermal effects from the reaction while mixing effects have a limited

  10. Non-destructive testing of the MEGAPIE target

    Science.gov (United States)

    Dai, Y.; Wohlmuther, M.; Boutellier, V.; Hahl, S.; Lagotzki, A.; Leu, H.; Linder, H. P.; Schwarz, R.; Spahr, A.; Zanini, L.; Kuster, D.; Gavillet, D.; Wagner, W.

    2016-01-01

    Non-destructive testing (NDT) is one important part of the post-irradiation examination (PIE) of the MEGAPIE target. It includes visual inspection and ultrasonic measurement of the beam window of the T91 LBE container and gamma mapping of the beam window of the AlMg3 safety-container. The visual inspection showed no visible failure in the proton beam window area of the T91 LBE container. The ultrasonic measurement demonstrated no detectable change in the wall thickness of the T91 beam window, which implies no severe corrosion effect induced by flowing LBE during the four-month irradiation period. The gamma mapping provided the distribution of 22Na, a spallation product, in the proton beam window area of the AlMg3 safety-container. The result was used to evaluate the accumulated proton fluence distribution profile, the input data for determining irradiation parameters. A maximum proton fluence of 1.9 × 1025 p/m2 was deduced. The corresponding displacement damage degree in the T91 beam window was 7.1 dpa.

  11. Qualifying program on Non-Destructive Testing, Visual Inspection of the welding (level 2)

    International Nuclear Information System (INIS)

    Shafee, M. A.

    2011-01-01

    Nondestructive testing is a wide group of analysis technique used in science and industry to evaluate the properties of a material, component or system without causing damage. Common Non-Destructive Testing methods include ultrasonic, magnetic-particle, liquid penetrate, radiographic, visual inspection and eddy-current testing. AAEA put the new book of the Non-Destructive Testing publication series that focused on Q ualifying program on Non-Destructive Testing, visual inspection of welding-level 2 . This book was done in accordance with the Arab standard certification of Non-Destructive Testing (ARAB-NDT-CERT-002) which is agreeing with the ISO-9712 (2005) and IAEA- TEC-DOC-487. It includes twenty one chapters dealing with engineering materials used in industry, the mechanical behavior of metals, metal forming equipments, welding, metallurgy, testing of welds, introduction to Non-Destructive Testing, defects in metals, welding defects and discontinuities, introduction to visual inspection theory, properties and tools of visual testing, visual testing, quality control regulations, standards, codes and specifications, procedures of welding inspections, responsibility of welding test inspector, qualification of Non-Destructive Testing inspector and health safety during working.

  12. Integrate models of ultrasonics examination for NDT expertise

    International Nuclear Information System (INIS)

    Calmon, P.; Lhemery, A.; Lecoeur-Taibi, I.; Raillon, R.

    1996-01-01

    For several years, the French Atomic Energy Commission (CEA) has developed a system called CIVA for multiple-technique NDE data acquisition and processing. Modeling tools for ultrasonic non-destructive testing have been developed and implemented within this allowing direct comparison between measured and predicted results. These models are not only devoted to laboratory uses bus also must be usable by ultrasonic operators without special training in simulation techniques. Therefore, emphasis has been on finding the best compromise between as accurate as possible quantitative predictions and ease, simplicity and speed, crucial requirements in the industrial context. This approach has led us to develop approximate models for the different phenomena involved in ultrasonic inspections: radiation, transmission through interfaces, propagation, scattering by defects and boundaries, reception etc. Two main models have been implemented, covering the most commonly encountered NDT configurations. At first, these two models are shortly described. Then, two examples of their applications are shown. Based on the same underlying theories, specific modeling tools are proposed to industrial partners to answer special requirements. To illustrate this, an example is given of a software used a tool to help experts's interpretation during on-site french PWR vessel inspections. Other models can be implemented in CIVA when some assumptions made in the previous models Champ-Sons and Mephisto are not fulfilled, e. g., when less-conventional testing configurations are concerned. We briefly presents as an example a modeling study of echoes arising from cladded steel surfaces achieved in the laboratory. (authors)

  13. Thickness measurement by using cepstrum ultrasonic signal processing

    International Nuclear Information System (INIS)

    Choi, Young Chul; Yoon, Chan Hoon; Choi, Heui Joo; Park, Jong Sun

    2014-01-01

    Ultrasonic thickness measurement is a non-destructive method to measure the local thickness of a solid element, based on the time taken for an ultrasound wave to return to the surface. When an element is very thin, it is difficult to measure thickness with the conventional ultrasonic thickness method. This is because the method measures the time delay by using the peak of a pulse, and the pulses overlap. To solve this problem, we propose a method for measuring thickness by using the power cepstrum and the minimum variance cepstrum. Because the cepstrums processing can divides the ultrasound into an impulse train and transfer function, where the period of the impulse train is the traversal time, the thickness can be measured exactly. To verify the proposed method, we performed experiments with steel and, acrylic plates of variable thickness. The conventional method is not able to estimate the thickness, because of the overlapping pulses. However, the cepstrum ultrasonic signal processing that divides a pulse into an impulse and a transfer function can measure the thickness exactly.

  14. Ultrasonic guided wave inspection of Inconel 625 brazed lap joints

    Science.gov (United States)

    Comot, Pierre; Bocher, Philippe; Belanger, Pierre

    2016-04-01

    The aerospace industry has been investigating the use of brazing for structural joints, as a mean of reducing cost and weight. There therefore is a need for a rapid, robust, and cost-effective non-destructive testing method for evaluating the structural integrity of the joints. The mechanical strength of brazed joints depends mainly on the amount of brittle phases in their microstructure. Ultrasonic guided waves offer the possibility of detecting brittle phases in joints using spatio-temporal measurements. Moreover, they offer the opportunity to inspect complex shape joints. This study focused on the development of a technique based on ultrasonic guided waves for the inspection of Inconel 625 lap joints brazed with BNi-2 filler metal. A finite element model of a lap joint was used to optimize the inspection parameters and assess the feasibility of detecting the amount of brittle phases in the joint. A finite element parametric study simulating the input signal shape, the center frequency, and the excitation direction was performed. The simulations showed that the ultrasonic guided wave energy transmitted through, and reflected from, the joints was proportional to the amount of brittle phases in the joint.

  15. Ultrasonic defect characterization using parametric-manifold mapping

    Science.gov (United States)

    Velichko, A.; Bai, L.; Drinkwater, B. W.

    2017-06-01

    The aim of ultrasonic non-destructive evaluation includes the detection and characterization of defects, and an understanding of the nature of defects is essential for the assessment of structural integrity in safety critical systems. In general, the defect characterization challenge involves an estimation of defect parameters from measured data. In this paper, we explore the extent to which defects can be characterized by their ultrasonic scattering behaviour. Given a number of ultrasonic measurements, we show that characterization information can be extracted by projecting the measurement onto a parametric manifold in principal component space. We show that this manifold represents the entirety of the characterization information available from far-field harmonic ultrasound. We seek to understand the nature of this information and hence provide definitive statements on the defect characterization performance that is, in principle, extractable from typical measurement scenarios. In experiments, the characterization problem of surface-breaking cracks and the more general problem of elliptical voids are studied, and a good agreement is achieved between the actual parameter values and the characterization results. The nature of the parametric manifold enables us to explain and quantify why some defects are relatively easy to characterize, whereas others are inherently challenging.

  16. Dental hard tissue characterization using laser-based ultrasonics

    Science.gov (United States)

    Blodgett, David W.; Massey, Ward L.

    2003-07-01

    Dental health care and research workers require a means of imaging the structures within teeth in vivo. One critical need is the detection of tooth decay in its early stages. If decay can be detected early enough, the process can be monitored and interventional procedures, such as fluoride washes and controlled diet, can be initiated to help re-mineralize the tooth. Currently employed x-ray imaging is limited in its ability to visualize interfaces and incapable of detecting decay at a stage early enough to avoid invasive cavity preparation followed by a restoration. To this end, non-destructive and non-contact in vitro measurements on extracted human molars using laser-based ultrasonics are presented. Broadband ultrasonic waves are excited in the extracted sections by using a pulsed carbon-dioxide (CO2) laser operating in a region of high optical absorption in the dental hard tissues. Optical interferometric detection of the ultrasonic wave surface displacements in accomplished with a path-stabilized Michelson-type interferometer. Results for bulk and surface in-vitro characterization of caries are presented on extracted molars with pre-existing caries.

  17. Flood Monitoring and Early Warning System Using Ultrasonic Sensor

    Science.gov (United States)

    Natividad, J. G.; Mendez, J. M.

    2018-03-01

    The purpose of this study is to develop a real-time flood monitoring and early warning system in the northern portion of the province of Isabela, particularly the municipalities near Cagayan River. Ultrasonic sensing techniques have become mature and are widely used in the various fields of engineering and basic science. One of advantage of ultrasonic sensing is its outstanding capability to probe inside objective non-destructively because ultrasound can propagate through any kinds of media including solids, liquids and gases. This study focuses only on the water level detection and early warning system (via website and/or SMS) that alerts concern agencies and individuals for a potential flood event. Furthermore, inquiry system is also included in this study to become more interactive wherein individuals in the community could inquire the actual water level and status of the desired area or location affected by flood thru SMS keyword. The study aims in helping citizens to be prepared and knowledgeable whenever there is a flood. The novelty of this work falls under the utilization of the Arduino, ultrasonic sensors, GSM module, web-monitoring and SMS early warning system in helping stakeholders to mitigate casualties related to flood. The paper envisions helping flood-prone areas which are common in the Philippines particularly to the local communities in the province. Indeed, it is relevant and important as per needs for safety and welfare of the community.

  18. Evaluation of Internal Cracks and Collapse in Poplar Wood (Populus nigra during a Conventional Drying Process with Ultrasonic Inspection

    Directory of Open Access Journals (Sweden)

    Saeid ESHAGHI

    2012-05-01

    Full Text Available In this research, internal cracks and collapse of wood, formed during drying process, were measured using ultrasonic inspection. For this purpose, seven poplar (Populus nigra small blocks were dried, according to a time-based schedule. Ultrasonic waves� propagation velocity was measured at both parallel and perpendicular to grain directions, using Sylvatest ultrasound device, during kiln drying process. Results showed that in all dried blocks, waves� propagation velocity in the parallel direction was higher than in the perpendicular direction to grain. Ultrasonic waves� propagation test for non-destructive identification of internal cracks, which occurs in wood during drying process in the parallel direction, was more successful compared to the perpendicular direction. Using ultrasonic waves� propagation test for detection of collapse that occurs in wood during drying process was not useful.

  19. Evaluation of Internal Cracks and Collapse in Poplar Wood (Populus nigra during a Conventional Drying Process with Ultrasonic Inspection

    Directory of Open Access Journals (Sweden)

    Saeid ESHAGHI

    2012-05-01

    Full Text Available In this research, internal cracks and collapse of wood, formed during drying process, were measured using ultrasonic inspection. For this purpose, seven poplar (Populus nigra small blocks were dried, according to a time-based schedule. Ultrasonic waves propagation velocity was measured at both parallel and perpendicular to grain directions, using Sylvatest ultrasound device, during kiln drying process. Results showed that in all dried blocks, waves propagation velocity in the parallel direction was higher than in the perpendicular direction to grain. Ultrasonic waves propagation test for non-destructive identification of internal cracks, which occurs in wood during drying process in the parallel direction, was more successful compared to the perpendicular direction. Using ultrasonic waves propagation test for detection of collapse that occurs in wood during drying process was not useful.

  20. Visualization of flaws within heavy section ultrasonic test blocks using high energy computed tomography

    International Nuclear Information System (INIS)

    House, M.B.; Ross, D.M.; Janucik, F.X.; Friedman, W.D.; Yancey, R.N.

    1996-05-01

    The feasibility of high energy computed tomography (9 MeV) to detect volumetric and planar discontinuities in large pressure vessel mock-up blocks was studied. The data supplied by the manufacturer of the test blocks on the intended flaw geometry were compared to manual, contact ultrasonic test and computed tomography test data. Subsequently, a visualization program was used to construct fully three-dimensional morphological information enabling interactive data analysis on the detected flaws. Density isosurfaces show the relative shape and location of the volumetric defects within the mock-up blocks. Such a technique may be used to qualify personnel or newly developed ultrasonic test methods without the associated high cost of destructive evaluation. Data is presented showing the capability of the volumetric data analysis program to overlay the computed tomography and destructive evaluation (serial metallography) data for a direct, three-dimensional comparison

  1. Ultrasonic characterization of GRC with high percentage of fly ash substitution.

    Science.gov (United States)

    Genovés, V; Gosálbez, J; Miralles, R; Bonilla, M; Payá, J

    2015-07-01

    New applications of non-destructive techniques (NDT) with ultrasonic tests (attenuation and velocity by means of ultrasonic frequency sweeps) have been developed for the characterization of fibre-reinforced cementitious composites. According to new lines of research on glass-fibre reinforced cement (GRC) matrix modification, two similar GRC composites with high percentages of fly ash and different water/binder ratios will be studied. Conventional techniques have been used to confirm their low Ca(OH)(2) content (thermogravimetry), fibre integrity (Scanning Electron Microscopy), low porosity (Mercury Intrusion Porosimetry) and good mechanical properties (compression and four points bending test). Ultrasound frequency sweeps allowed the estimation of the attenuation and pulse velocity as functions of frequency. This ultrasonic characterization was correlated successfully with conventional techniques. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Residual stress determination of rail tread using a laser ultrasonic technique

    International Nuclear Information System (INIS)

    Wang, Jing; Feng, Qibo

    2015-01-01

    A non-destructive method for measuring the residual stress on rail tread that uses a laser-generated ultrasonic technique is proposed. The residual stress distribution of different parts on both the new rail and used rail were examined. The surface acoustic waves (SAWs) are excited by a scanning line laser and detected by a laser ultrasonic detection system. A digital correlation method was used for calculating the changes in velocity of SAWs, which reflects the stress distribution. A wavelet de-noising technique and a least square fit were used for signal processing to improve the measurement accuracy. The effects of ultrasonic propagation distance and surface roughness on the determination of residual stress were analyzed and simulated. Results from the study demonstrate that the stress distribution results are accordant with the practical situation, and the laser-generated SAWs technique is a promising tool for the determination of residual stress in the railway inspection and other industrial testing fields. (paper)

  3. Two-dimensional analytic modeling of acoustic diffraction for ultrasonic beam steering by phased array transducers.

    Science.gov (United States)

    Wang, Tiansi; Zhang, Chong; Aleksov, Aleksandar; Salama, Islam; Kar, Aravinda

    2017-04-01

    Phased array ultrasonic transducers enable modulating the focal position of the acoustic waves, and this capability is utilized in many applications, such as medical imaging and non-destructive testing. This type of transducers also provides a mechanism to generate tilted wavefronts in acousto-optic deflectors to deflect laser beams for high precision advanced laser material processing. In this paper, a theoretical model is presented for the diffraction of ultrasonic waves emitted by several phased array transducers into an acousto-optic medium such as TeO 2 crystal. A simple analytic expression is obtained for the distribution of the ultrasonic displacement field in the crystal. The model prediction is found to be in good agreement with the results of a numerical model that is based on a non-paraxial multi-Gaussian beam (NMGB) model. Published by Elsevier B.V.

  4. Monitoring of Freeze-Thaw Cycles in Concrete Using Embedded Sensors and Ultrasonic Imaging

    Science.gov (United States)

    Ranz, Javier; Aparicio, Sofía; Romero, Héctor; Casati, María Jesús; Molero, Miguel; González, Margarita

    2014-01-01

    This paper deals with the study of damage produced during freeze-thaw (F-T) cycles using two non-destructive measurement approaches—the first approach devoted to continuous monitoring using embedded sensors during the cycles, and the second one, performing ultrasonic imaging before and after the cycles. Both methodologies have been tested in two different types of concrete specimens, with and without air-entraining agents. Using the first measurement approach, the size and distribution of pores were estimated using a thermoporometrical model and continuous measurements of temperature and ultrasonic velocity along cycles. These estimates have been compared with the results obtained using mercury porosimetry testing. In the second approach, the damage due to F-T cycles has been evaluated by automated ultrasonic transmission and pulse-echo inspections made before and after the cycles. With these inspections the variations in the dimensions, velocity and attenuation caused by the accelerated F-T cycles were determined. PMID:24481231

  5. Flaw characterization through nonlinear ultrasonics and wavelet cross-correlation algorithms

    Science.gov (United States)

    Bunget, Gheorghe; Yee, Andrew; Stewart, Dylan; Rogers, James; Henley, Stanley; Bugg, Chris; Cline, John; Webster, Matthew; Farinholt, Kevin; Friedersdorf, Fritz

    2018-04-01

    Ultrasonic measurements have become increasingly important non-destructive techniques to characterize flaws found within various in-service industrial components. The prediction of remaining useful life based on fracture analysis depends on the accurate estimation of flaw size and orientation. However, amplitude-based ultrasonic measurements are not able to estimate the plastic zones that exist ahead of crack tips. Estimating the size of the plastic zone is an advantage since some flaws may propagate faster than others. This paper presents a wavelet cross-correlation (WCC) algorithm that was applied to nonlinear analysis of ultrasonically guided waves (GW). By using this algorithm, harmonics present in the waveforms were extracted and nonlinearity parameters were used to indicate both the tip of the cracks and size of the plastic zone. B-scans performed with the quadratic nonlinearities were sensitive to micro-damage specific to plastic zones.

  6. A study on non-contact ultrasonic technique for on-line inspection of CFRP

    International Nuclear Information System (INIS)

    Lee, Seung-Joon; Park, Won-Su; Lee, Joon-Hyun; Byun, Joon-Hyung

    2007-01-01

    The advantages of carbon fiber reinforced plastic materials (CFRP) are: they are light structure materials, they have corrosion resistance, and higher specific strength and elasticity. The recently developed 3-dimentional fiber placement system is able to produce a more complex and various shaped structures due to less limitations of a product shape according to the problem in conventional fabrication process. This fiber placement system stacks the narrow prepreg tape on the mold according to the designed sequence and thickness. Non-destructive evaluation was rquired for these composites to evaluate changes in strength caused by defects such as delamination and porosity. Additionally, the expectent quality should be satisfied for the high cost fabrication process using the fiber placement system. Therefore, an on line non-destructive evaluation system is required and real-time complement is needed when the defects are detected [1]. Defect imaging by the ultrasonic C-scan method is a useful technique for defect detection in CFRP. However, the conventional ultrasonic C-scan technique cannot be applied during the fabrication process because the test piece should be immersed into the water. Therefore, non-contact ultrasonic techniques should be applied during the fabricating process. For the development of non-contact ultrasonic techniques available in non-destructive evaluation of CFRP, a recent laser-generated ultrasonic technique and an air-coupled transducer that transmit and receive ultrasounds in the air are studied [2-3]. In this study, generating and receiving techniques of laser-generated ultrasound and the characteristics of received signals upon the internal defects of CFRO were studied for non-contact inspection

  7. Ultrasound-mediated microbubble enhancement of radiation therapy studied using three-dimensional high-frequency power Doppler ultrasound.

    Science.gov (United States)

    Kwok, Sheldon J J; El Kaffas, Ahmed; Lai, Priscilla; Al Mahrouki, Azza; Lee, Justin; Iradji, Sara; Tran, William Tyler; Giles, Anoja; Czarnota, Gregory J

    2013-11-01

    Tumor responses to high-dose (>8 Gy) radiation therapy are tightly connected to endothelial cell death. In the study described here, we investigated whether ultrasound-activated microbubbles can locally enhance tumor response to radiation treatments of 2 and 8 Gy by mechanically perturbing the endothelial lining of tumors. We evaluated vascular changes resulting from combined microbubble and radiation treatments using high-frequency 3-D power Doppler ultrasound in a breast cancer xenograft model. We compared treatment effects and monitored vasculature damage 3 hours, 24 hours and 7 days after treatment delivery. Mice treated with 2 Gy radiation and ultrasound-activated microbubbles exhibited a decrease in vascular index to 48 ± 10% at 24 hours, whereas vascular indices of mice treated with 2 Gy radiation alone or microbubbles alone were relatively unchanged at 95 ± 14% and 78 ± 14%, respectively. These results suggest that ultrasound-activated microbubbles enhance the effects of 2 Gy radiation through a synergistic mechanism, resulting in alterations of tumor blood flow. This novel therapy may potentiate lower radiation doses to preferentially target endothelial cells, thus reducing effects on neighboring normal tissue and increasing the efficacy of cancer treatments. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

  8. Transient permeabilization of cell membranes by ultrasound-exposed microbubbles is related to formation of hydrogen peroxide.

    Science.gov (United States)

    Juffermans, L J M; Dijkmans, P A; Musters, R J P; Visser, C A; Kamp, O

    2006-10-01

    In the present study, we addressed the interactions among ultrasound, microbubbles, and living cells as well as consequent arising bioeffects. We specifically investigated whether hydrogen peroxide (H(2)O(2)) is involved in transient permeabilization of cell membranes in vitro after ultrasound exposure at low diagnostic power, in the presence of stable oscillating microbubbles, by measuring the generation of H(2)O(2) and Ca(2+) influx. Ultrasound, in the absence or presence of SonoVue microbubbles, was applied to H9c2 cells at 1.8 MHz with a mechanical index (MI) of 0.1 or 0.5 during 10 s. This was repeated every minute, for a total of five times. The production of H(2)O(2) was measured intracellularly with CM-H(2)DCFDA. Cell membrane permeability was assessed by measuring real-time changes in intracellular Ca(2+) concentration with fluo-4 using live-cell fluorescence microscopy. Ultrasound, in the presence of microbubbles, caused a significant increase in intracellular H(2)O(2) at MI 0.1 of 50% and MI 0.5 of 110% compared with control (P ultrasound exposure was completely blocked at MI 0.1 (P ultrasound-exposed microbubbles.

  9. Hemostatic mechanism underlying microbubble-enhanced non-focused ultrasound in the treatment of a rabbit liver trauma model

    Science.gov (United States)

    Zhao, Da-wei; Tian, Meng; Yang, Jian-zheng; Du, Peng; Bi, Jie; Zhu, Xinjian

    2016-01-01

    The aim of our study was to investigate the hemostatic mechanism underlying microbubble-enhanced non-focused ultrasound treatment of liver trauma. Thirty rabbits with liver trauma were randomly divided into three groups—the microbubble-enhanced ultrasound (MEUS; further subdivided based on exposure intensity into MEUS1 [0.11 W/cm2], MEUS2 [0.55 W/cm2], and MEUS3 [1.1 W/cm2]), ultrasound without microbubbles (US), and microbubbles without ultrasound (MB) groups. The pre- and post-treatment bleeding weight and visual bleeding scores were evaluated. The serum liver enzyme concentrations as well as the blood perfusion level represented by mean peak contrast intensity (PI) ratio in the treatment area were analyzed. The hemostatic mechanism was evaluated by histological and transmission electron microscopic examination of liver tissue samples. The MEUS subgroups 1–3 (grade 0–1, grade 0–2, and grade 1–2, respectively) exhibited significantly lower post-treatment visual bleeding scores than the US and MB groups (both, grade 3–4; all, P hepatic cells became edematous and compressed the hepatic sinus and associated blood vessels. However, the serum liver enzyme levels were not significantly altered. Microbubble-enhanced non-focused ultrasound does not significantly affect blood perfusion and liver function and can be used to induce rapid hemostasis in case of liver trauma. PMID:27633577

  10. Design of ultrasonic probe and evaluation of ultrasonic waves on E.coli in Sour Cherry Juice

    Directory of Open Access Journals (Sweden)

    B Hosseinzadeh Samani

    2015-09-01

    experimental methodology generates a mathematical model which describes the chemical or biochemical processes (Anjum et al., 1997, Halim et al., 2009. In order to obtain the optimum value, Eq. (1 will be used: (6\tY_i=β_0+∑▒〖β_i X_i+∑▒〖β_ij X_i X_j+〗〗 ∑▒〖β_ij X_i^2 〗+ε where, β0, βj, βij, βjj are regression coefficients for intercept, linear, interaction and quadratic coefficients, respectively, while Xi and Xj are coded independent variables and ε is the error. For this purpose, four factors of ultrasonic power (200 to 600 W, wave exposure time (5 to 15 min, probe diameter (20 to 40 mm, and probe penetration depth in sour cherry juice container (0 to 40 mm were selected. First, the probes with the desired diameters were designed using the related formulas by using CAD-CAM. Results and Discussion: Surface Method (RSM indicated that the quadratic model with 0.96 coefficient of friction, standard error of 1545.3, and coefficient of variation of 14% is the best model for estimating the number of E.coli bacteria among the different studied treatments. The results showed that with increasing probe diameter and probe depth, the destructive effects of ultrasonic wave increase. It was also revealed that as the probe diameter and penetration depth increase, the destructive effect of ultrasonic wave is initially increased and then follows by a decreasing trend. With the increasing power of ultrasonic, ultrasonic intensity increases and leads to reducing number of E.coli in sour cherry juice. The increase in time of treatment with ultrasonic causes a decrease in the number of E.coli in sour cherry juice. This is due to the fact that the increase of ultrasonic exposure time leads to the increase of sonic stream in reactor and results in higher contributions of ultrasonic waves to E.coli. Finally, the examined variables were optimized by RSM and the values of ultrasonic power, waves exposing time, probe diameter, and probe penetration depth were obtained

  11. Image processing applied to automatic detection of defects during ultrasonic examination

    International Nuclear Information System (INIS)

    Moysan, J.

    1992-10-01

    This work is a study about image processing applied to ultrasonic BSCAN images which are obtained in the field of non destructive testing of weld. The goal is to define what image processing techniques can bring to ameliorate the exploitation of the data collected and, more precisely, what image processing can do to extract the meaningful echoes which enable to characterize and to size the defects. The report presents non destructive testing by ultrasounds in the nuclear field and it indicates specificities of the propagation of ultrasonic waves in austenitic weld. It gives a state of the art of the data processing applied to ultrasonic images in nondestructive evaluation. A new image analysis is then developed. It is based on a powerful tool, the co-occurrence matrix. This matrix enables to represent, in a whole representation, relations between amplitudes of couples of pixels. From the matrix analysis, a new complete and automatic method has been set down in order to define a threshold which separates echoes from noise. An automatic interpretation of the ultrasonic echoes is then possible. Complete validation has been done with standard pieces

  12. Detailed simulation of ultrasonic inspections

    International Nuclear Information System (INIS)

    Chaplin, K.R.; Douglas, S.R.; Dunford, D.

    1997-01-01

    Simulation of ultrasonic inspection of engineering components have been performed at the Chalk River Laboratories of AECL for over 10 years. The computer model, called EWE for Elastic Wave Equations, solves the Elastic Wave Equations using a novel finite difference scheme. It simulates the propagation of an ultrasonic wave from the transducer to a flaw, the scatter of waves from the flaw, and measurement of signals at a receive transducer. Regions of different materials, water and steel for example, can be simulated. In addition, regions with slightly different material properties from the parent material can be investigated. The two major types of output are displays of the ultrasonic waves inside the component and the corresponding A-scans. EPRI and other organizations have used ultrasonic models for: defining acceptable ultrasonic inspection procedures, designing and evaluating inspection techniques, and for quantifying inspection reliability. The EWE model has been applied to the inspection of large pipes in a nuclear plant, gas pipeline welds and steam generator tubes. Most recent work has dealt with the ultrasonic inspection of pressure tubes in CANDU reactors. Pressure tube inspections can reliably detect and size defects; however, there are improvements that can be made. For example, knowing the sharpness of a flaw-tip is crucial for fitness for service assessments. Computer modelling of the ultrasonic inspection of flaws with different root radius has suggested inspection techniques that provide flaw tip radius information. A preliminary investigation of these methods has been made in the laboratory. The basis for the model will be reviewed at the presentation. Then the results of computer simulations will be displayed on a PC using an interactive program that analyzes simulated A-scans. This software tool gives inspection staff direct access to the results of computer simulations. (author)

  13. Non-destructive evaluation on mechanical properties of nuclear graphite with porous structure

    International Nuclear Information System (INIS)

    Shibata, Taiju; Hanawa, Satoshi; Sumita, Junya; Tada, Tatsuya; Sawa, Kazuhiro; Iyoku, Tatsuo

    2005-01-01

    As a research subjects of 'Research and development for advanced high temperature gas cooled reactor fuels and graphite components,' we started the study of development of non-destructive evaluation methods for mechanical properties of graphite components. The micro-indentation and ultrasonic wave methods are focused to evaluate the degradation of graphite components in VHTR core. For the micro-indentation method, the test apparatus was designed for the indentation test on graphite specimens with some stress levels. It is expected the stress condition is evaluated by the indentation load-depth characteristics and hardness. For the ultrasonic wave method, ultrasonic wave testing machine and probes were prepared for experiments. It is expected that the stress and inner porous conditions are evaluated by the wave propagation characteristics with wave-pore interaction model. R and D plan to develop the non-destructive evaluation method for graphite is presented in this paper. (This study is the result of contract research in the fiscal year of 2004, Research and development for advanced high temperature gas cooled reactor fuels and graphite components,' which is entrusted to the Japan Atomic Energy Research Institute from the Ministry of Education, Culture, Sports, Science and Technology of Japan.) (author)

  14. Ultrasonic measurements and technologies

    CERN Document Server

    Kočiš, Štefan

    1996-01-01

    An impulse for writing this book has originated from the effort to sum­ marize and publicise the acquired results of a research team at the De­ partment of Automation of the Faculty of Electrical Engineering and In­ formatics, Slovak Technical University in Bratislava. The research team has been involved for a long time with control problems for machine production mechanisms and, in recent (approximately 15) years, its effort was aimed mostly at the control of electrical servosystems of robots. Within this scope, the members of the authors' staff solved the State Re­ search Task Ultrasonic sensing of the position of a robot hand, which was coordinated by the Institute of Technical Cybernetics of the Slovak Academy of Sciences in Bratislava. The problem was solved in a complex way, i.e. from a conceptual de­ sign of the measurement, through the measurement and evaluation sys­ tem, up to connection to the control system of a robot. Compensation of the atmospheric influence on the precision of measurement,...

  15. Ultrasonic-testing method

    International Nuclear Information System (INIS)

    Thome, Paul.

    1973-01-01

    Description is given of a device adapted to the detection, by means of ultrasonic waves, of all the flaws and defects included in workpieces when only one face of the latter is accessible. A beam is directed towards the rear-face of the workpiece (e.g. a plate) on which it is reflected. The image thus reflected is fed into a receiver. The latter is under the control of the displacement of that image; simultaneously a transducer checks the condition of the mirror at the places where the beam is reflected. Whenever a flow or defect comes between, a silent zone is formed. By recording the silent zones with respect to the positions of several emitters, it is possible to locates a flaw and to define the outline thereof. The apparatus comprises several ''emitter-receiver'' groups intersecting over the emitter used in order to check the good conditions of the mirror. The invention can be used for searching and identifying flaws and defects in buildings which have to be of top quality (e.g., cofferdams, nuclear devices, shipbuilding yards, aeronautics) [fr

  16. Ultrasonic monitoring system

    International Nuclear Information System (INIS)

    McLain, R.E.

    1975-01-01

    The ultrasonic monitoring system is used in LMFBR's, BWR's or PWR's. A remotely controlled, movable instrument carrier may be used which contains the piezo-electric transducer and is connected to the main control console by a transmission cable. An excitation pulse coming from a pulse generator is used to excite the transducer with a maximum of energy, independent of the length of the transmission line. Pulse width and pulse amplitude can be set without any direct interference into the transducer. For this purpose, a resistor whose impedance has been matched to that of the transmission line is connected to the input of the transmission line. Moreover, a capacitor for generation of the excitation pulse is coupled with the transmission line by means of a four-layer switching diode and is discharged. For termination of the excitation and the control pulses, respectively, another four-layer switching diode connected parallel to the capacitor quickly discharges the capacitor. The capacitor and the capacitance of the line constitute a voltage divider. In this way it is possible to change the length of the transmission line and, to safeguard the generation of a pulse of the desired amplitude, only vary the capacitance of the capacitor. (DG/RF) [de

  17. Total destruction of PCB transformers

    International Nuclear Information System (INIS)

    Myers, D.S.

    1991-01-01

    This paper reports that if elimination of PCB liability, including lingering liabilities, is the goal, then landfilling cannot be and option. The law is clear that the generator of PCB waste is responsible for that waste until this destruction. Landfilling is not destruction. Retrofilling as askarel units will not get rid of all PCB liabilities, either. Askarel retrofilling can only make this claim when it can give a lifetime guaranty of no detectable PCBs. States like Washington and California regulate, as hazardous waste, fluids which contain greater than 2 and 5 ppm PCB, respectively. There is no guarantee that your state will not so regulate PCBs in the future or that the federal laws might tighten up. Therefore, replacement and disposal by Resource Recovery constitutes the only lifetime guarantee on the market that the PCBs in your askarel transformers will never come back to haunt you

  18. Defining Weapons of Mass Destruction

    Science.gov (United States)

    2012-01-01

    Cyprus, Liberia, Malta, Marshall Islands , Mongolia, Panama, and St. Vin- cent and the Grenadines, according to a State Department summary available...1972 Biological and Toxin Weapons Convention, and the 1993 Chemical Weapons Convention. As such, NBC weapons represent a group of weapons that the...Development, Produc- tion and Stockpiling of Bacteriological (Biological) and Toxin Weapons and on Their Destruction contains two references to WMD

  19. Ultrasonic propulsion of kidney stones.

    Science.gov (United States)

    May, Philip C; Bailey, Michael R; Harper, Jonathan D

    2016-05-01

    Ultrasonic propulsion is a novel technique that uses short bursts of focused ultrasonic pulses to reposition stones transcutaneously within the renal collecting system and ureter. The purpose of this review is to discuss the initial testing of effectiveness and safety, directions for refinement of technique and technology, and opinions on clinical application. Preclinical studies with a range of probes, interfaces, and outputs have demonstrated feasibility and consistent safety of ultrasonic propulsion with room for increased outputs and refinement toward specific applications. Ultrasonic propulsion was used painlessly and without adverse events to reposition stones in 14 of 15 human study participants without restrictions on patient size, stone size, or stone location. The initial feasibility study showed applicability in a range of clinically relevant situations, including facilitating passage of residual fragments following ureteroscopy or shock wave lithotripsy, moving a large stone at the ureteropelvic junction with relief of pain, and differentiating large stones from a collection of small fragments. Ultrasonic propulsion shows promise as an office-based system for transcutaneously repositioning kidney stones. Potential applications include facilitating expulsion of residual fragments following ureteroscopy or shock wave lithotripsy, repositioning stones prior to treatment, and repositioning obstructing ureteropelvic junction stones into the kidney to alleviate acute renal colic.

  20. Chondrule destruction in nebular shocks

    Energy Technology Data Exchange (ETDEWEB)

    Jacquet, Emmanuel; Thompson, Christopher, E-mail: ejacquet@mnhn.fr [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St George Street, Toronto, ON M5S 3H8 (Canada)

    2014-12-10

    Chondrules are millimeter-sized silicate spherules ubiquitous in primitive meteorites, but whose origin remains mysterious. One of the main proposed mechanisms for producing them is melting of solids in shock waves in the gaseous protoplanetary disk. However, evidence is mounting that chondrule-forming regions were enriched in solids well above solar abundances. Given the high velocities involved in shock models, destructive collisions would be expected between differently sized grains after passage of the shock front as a result of differential drag. We investigate the probability and outcome of collisions of particles behind a one-dimensional shock using analytic methods as well as a full integration of the coupled mass, momentum, energy, and radiation equations. Destruction of protochondrules seems unavoidable for solid/gas ratios ε ≳ 0.1, and possibly even for solar abundances because of 'sandblasting' by finer dust. A flow with ε ≳ 10 requires much smaller shock velocities (∼2 versus 8 km s{sup –1}) in order to achieve chondrule-melting temperatures, and radiation trapping allows slow cooling of the shocked fragments. Initial destruction would still be extensive; although re-assembly of millimeter-sized particles would naturally occur by grain sticking afterward, the compositional heterogeneity of chondrules may be difficult to reproduce. We finally note that solids passing through small-scale bow shocks around few kilometer-sized planetesimals might experience partial melting and yet escape fragmentation.

  1. Destructive analysis and evaluation services

    International Nuclear Information System (INIS)

    Kuhn, E.; Lemaire, R.; Wenzel, U.; Aigner, H.; Bagliano, G.; Deron, S.; Jordan, L.

    1986-07-01

    This manual describes the procedures for independent verification measurements by Destructive Analysis as required by the Divisions of Operations. It includes the relevant instructions and information necessary to achieve the verification from sampling through final use of the evaluation results. It is a working/reference document for the Inspectors and for the supporting units, as well as a training manual for Inspectors which brings together all the necessary information for verification by Destructive Analysis. This manual gives information essential to the Inspector and to the units of the Safeguards Analytical Services (SAS) in the following areas: material stratification, sampling, sample conditioning and data collection; packaging, transporting, tracking, receipt and analysis of samples; and evaluation and final use of the evaluation results. This information is provided as: specific instructions and/or examples; summaries of relevant, existing documents; and references to existing documents. Forms are available for sample, item and stratum data collection as well as for transfer of samples and for the reporting of results. A complete typical example package of the documents related to the verification by Destructive Analysis is included. In addition, summaries of the analytical procedures used at the Safeguards Analytical Laboratory (SAL) of the IAEA and the expected measurement performance for element assay and isotopic abundance are provided. (author)

  2. Ultrasonic stir welding process and apparatus

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2009-01-01

    An ultrasonic stir welding device provides a method and apparatus for elevating the temperature of a work piece utilizing at least one ultrasonic heater. Instead of relying on a rotating shoulder to provide heat to a workpiece an ultrasonic heater is utilized to provide ultrasonic energy to the workpiece. A rotating pin driven by a motor assembly performs the weld on the workpiece. A handheld version can be constructed as well as a fixedly mounted embodiment.

  3. The effects of ultrasonic solidification on aluminum

    OpenAIRE

    Đorđević Slavko 1

    2003-01-01

    The effect of ultrasound on characteristics of solidified aluminum was shown. An ultrasonic head and ultrasonic system for modification was designed and applied to the crystallizing aluminum melt. The ultrasonic generator allows power of 50-500 W, amplitude of oscillations 10-100 um.m and the operating frequency of 25 kHz. Ultrasonic modification was done by ultrasound introduced from above into the melt. Microstructure photographs show decreasing of the grain size more than five times.

  4. The effects of ultrasonic solidification on aluminum

    Directory of Open Access Journals (Sweden)

    Đorđević Slavko 1

    2003-01-01

    Full Text Available The effect of ultrasound on characteristics of solidified aluminum was shown. An ultrasonic head and ultrasonic system for modification was designed and applied to the crystallizing aluminum melt. The ultrasonic generator allows power of 50-500 W, amplitude of oscillations 10-100 um.m and the operating frequency of 25 kHz. Ultrasonic modification was done by ultrasound introduced from above into the melt. Microstructure photographs show decreasing of the grain size more than five times.

  5. Reliability of non-destructive test techniques in the inspection of pipelines used in the oil industry

    International Nuclear Information System (INIS)

    Carvalho, A.A.; Rebello, J.M.A.; Souza, M.P.V.; Sagrilo, L.V.S.; Soares, S.D.

    2008-01-01

    The aim of this work is to evaluate the reliability of non-destructive test (NDT) techniques for the inspection of pipeline welds employed in the petroleum industry. Radiography, manual and automatic ultrasonic techniques using pulse-echo and time of flight diffraction (TOFD) were employed. Three classes of defects were analyzed: lack of penetration (LP), lack of fusion (LF) and undercut (UC). The tests were carried out on specimen made from pipelines containing defects, which had been artificially inserted on laying the weld bead. The results showed the superiority of the automatic ultrasonic tests for defect detection compared with the manual ultrasonic and radiographic tests. Additionally, artificial neural networks (ANN) were used in the detection and automatic classification of the defects

  6. Cell Lysis and Detoxification of Cyanotoxins Using a Novel Combination of Microbubble Generation and Plasma Microreactor Technology for Ozonation

    Directory of Open Access Journals (Sweden)

    Jagroop Pandhal

    2018-04-01

    Full Text Available There has been a steady rise in the incidences of algal blooms globally, and worryingly, there is increasing evidence that changes in the global climate are leading to a shift toward cyanobacterial blooms. Many cyanobacterial genera are harmful, producing several potent toxins, including microcystins, for which there are over 90 described analogues. There are a wide range of negative effects associated with these toxins including gastroenteritis, cytotoxicity, hepatotoxicity and neurotoxicity. Although a variety of oxidation based treatment methods have been described, ozonation and advanced oxidation are acknowledged as most effective as they readily oxidise microcystins to non-toxic degradation products. However, most ozonation technologies have challenges for scale up including high costs and sub-optimum efficiencies, hence, a low cost and scalable ozonation technology is needed. Here we designed a low temperature plasma dielectric barrier discharge (DBD reactor with an incorporated fluidic oscillator for microbubble delivery of ozone. Both technologies have the potential to drastically reduce the costs of ozonation at scale. Mass spectrometry analysis revealed very rapid (<2 min destruction of two pure microcystins (MC-LR and MC-RR, together with removal of by-products even at low flow rate 1 L min−1 where bubble size was 0.56–0.6 mm and the ozone concentration within the liquid was 20 ppm. Toxicity levels were calculated through protein phosphatase inhibition assays and indicated loss of toxicity as well as confirming the by-products were also non-toxic. Finally, treatment of whole Microcystis aeruginosa cells showed that even at these very low ozone levels, cells can be killed and toxins (MC-LR and Desmethyl MC-LR removed. Little change was observed in the first 20 min of treatment followed by rapid increase in extracellular toxins, indicating cell lysis, with most significant release at the higher 3 L min−1 flow rate compared to 1 L

  7. The multiphase flow system used in exploiting depleted reservoirs: water-based Micro-bubble drilling fluid

    International Nuclear Information System (INIS)

    Zheng Lihui; He Xiaoqing; Wang Xiangchun; Fu Lixia

    2009-01-01

    Water-based micro-bubble drilling fluid, which is used to exploit depleted reservoirs, is a complicated multiphase flow system that is composed of gas, water, oil, polymer, surfactants and solids. The gas phase is separate from bulk water by two layers and three membranes. They are 'surface tension reducing membrane', 'high viscosity layer', 'high viscosity fixing membrane', 'compatibility enhancing membrane' and 'concentration transition layer of liner high polymer (LHP) and surfactants' from every gas phase centre to the bulk water. 'Surface tension reducing membrane', 'high viscosity layer' and 'high viscosity fixing membrane' bond closely to pack air forming 'air-bag', 'compatibility enhancing membrane' and 'concentration transition layer of LHP and surfactants' absorb outside 'air-bag' to form 'incompact zone'. From another point of view, 'air-bag' and 'incompact zone' compose micro-bubble. Dynamic changes of 'incompact zone' enable micro-bubble to exist lonely or aggregate together, and lead the whole fluid, which can wet both hydrophilic and hydrophobic surface, to possess very high viscosity at an extremely low shear rate but to possess good fluidity at a higher shear rate. When the water-based micro-bubble drilling fluid encounters leakage zones, it will automatically regulate the sizes and shapes of the bubbles according to the slot width of fracture, the height of cavern as well as the aperture of openings, or seal them by making use of high viscosity of the system at a very low shear rate. Measurements of the rheological parameters indicate that water-based micro-bubble drilling fluid has very high plastic viscosity, yield point, initial gel, final gel and high ratio of yield point and plastic viscosity. All of these properties make the multiphase flow system meet the requirements of petroleum drilling industry. Research on interface between gas and bulk water of this multiphase flow system can provide us with information of synthesizing effective

  8. The Effect of Docetaxel-Loaded Micro-Bubbles Combined with Low-Frequency Ultrasound in H22 Hepatocellular Carcinoma-Bearing Mice.

    Science.gov (United States)

    Ren, Shu-Ting; Shen, Shu; He, Xin-Ying; Liao, Yi-Ran; Sun, Peng-Fei; Wang, Bing; Zhao, Wen-Bao; Han, Shui-Ping; Wang, Yi-Li; Tian, Tian

    2016-02-01

    A novel lipid micro-bubble (MB) loaded with docetaxel (DOC-MB) was investigated in a previous study. However, its anti-tumor effects and mechanism of action in combination with low-frequency ultrasound (LFUS) in vivo are still unclear. DOC-MBs containing 5.0 mg of DOC were prepared by lyophilization with modification via ultrasonic emulsification. Then, the effects of DOC-MBs combined with LFUS on tumor growth, proliferating cell nuclear antigen (PCNA) expression and cell apoptosis, as well as local DOC delivery, were investigated in H22 hepatocellular carcinoma (HCC)-bearing mice. Compared with the previously prepared DOC-MBs (1.6 mg of DOC loaded), the encapsulation efficiency (81.2% ± 3.89%) and concentration ([7.94 ± 0.04] × 10(9) bubbles/mL) of the DOC-MBs containing 5.0 mg of DOC were higher, but the bubble size (1.368 ± 0.004 μm) was smaller. After treatment with the DOC-MBs and LFUS, the H22 HCC growth inhibition rate was significantly increased, PCNA expression in tumor tissue was significantly inhibited and local release of DOC was induced. In conclusion, new DOC-MBs containing 5.0 mg of DOC were successfully prepared with a high encapsulation efficiency and superior bubble size and concentration, and their combination with LFUS significantly enhanced the anti-tumor effect of DOC in H22 HCC-bearing mice by inhibiting tumor cell proliferation and increasing local drug delivery. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  9. The Combine Use of Semi-destructive and Non-destructive Methods for Tiled Floor Diagnostics

    Science.gov (United States)

    Štainbruch, Jakub; Bayer, Karol; Jiroušek, Tomáš; Červinka, Josef

    2017-04-01

    resistivity drilling, and non-destructive georadar, and the results were compared. Floors were measured by 3D laser scanning technology and captured by the camera before reconstruction work. Using SFM photogrammetry were achieved results: ortomozaik (0.3 mm / pix) and DEM (0.6 mm / pix). These results were a basis for restoration work and also allow comparisons with the original state at any stage of the project. Drilling resistance measurement is used for indirect determination of strength profile based on resistance to drilling depending on into the depth. The observed resistance to drilling correlates with the strength and toughness of the measured material. The method is referred as a micro- or semi-invasive, since sampling is not necessary and but the drilling diameter is usually 3-5 mm. The ultrasonic measurement consists in the measuring of the longitude as well as the transverse waves - velocity, shape, amplitude. The propagation velocity is a characteristic values for the material influenced by its composition and compactness. Georadar (GPR) is a high frequency electromagnetic pulse method. For measurement the GPR RAMAC system coupled with 1600 MHz shielded antenna was used. Two tiles (one with defects and one in relatively good condition) were surveyed in a regular grid of perpendicular lines 5 cm separated. Data were processed by means of ReflexW software and performed in the form of cross sections and amplitude maps. The map of the amplitude summed over a time window 1 - 1,4 ns (representing the intensity of the reflection from the tiles bottom) gave good result. The areas of registered relatively high amplitudes correspond with the position of airgaps. A correlation was observed between the results of different survey methods.

  10. 21 CFR 872.4850 - Ultrasonic scaler.

    Science.gov (United States)

    2010-04-01

    ... DEVICES DENTAL DEVICES Surgical Devices § 872.4850 Ultrasonic scaler. (a) Identification. An ultrasonic scaler is a device intended for use during dental cleaning and periodontal (gum) therapy to remove calculus deposits from teeth by application of an ultrasonic vibrating scaler tip to the teeth. (b...

  11. Pitch-catch only ultrasonic fluid densitometer

    Science.gov (United States)

    Greenwood, M.S.; Harris, R.V.

    1999-03-23

    The present invention is an ultrasonic fluid densitometer that uses a material wedge and pitch-catch only ultrasonic transducers for transmitting and receiving ultrasonic signals internally reflected within the material wedge. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface. 6 figs.

  12. Ultrasonic techniques for fluids characterization

    CERN Document Server

    Povey, Malcolm J W

    1997-01-01

    This book is a comprehensive and practical guide to the use of ultrasonic techniques for the characterization of fluids. Focusing on ultrasonic velocimetry, the author covers the basic topics and techniques necessaryfor successful ultrasound measurements on emulsions, dispersions, multiphase media, and viscoelastic/viscoplastic materials. Advanced techniques such as scattering, particle sizing, and automation are also presented. As a handbook for industrial and scientific use, Ultrasonic Techniques for Fluids Characterization is an indispensable guide to chemists and chemical engineers using ultrasound for research or process monitoring in the chemical, food processing, pharmaceutical, cosmetic, biotechnology,and fuels industries. Key Features * Appeals to anyone using ultrasound to study fluids * Provides the first detailed description of the ultrasound profiling technique for dispersions * Describes new techniques for measuring phase transitions and nucleation, such as water/ice and oil/fat * Presents the l...

  13. Ultrasonic inspection development at HEDL

    International Nuclear Information System (INIS)

    Day, C.K.; Mech, S.J.; Michaels, T.E.; Dixon, N.E.

    1978-01-01

    Ultrasonic testing methods and equipment are being developed to support preservice and in-service inspection of selected FFTF welds. A digital computer system is employed in the analysis of both simulated FFTF pipe sections and plate specimens containing fatigue cracks. It is anticipated that test evaluation standards containing fatigue cracks will partially eliminate questions formerly associated with weld test calibration producers by providing natural cracks which follow grain boundaries and stress patterns resembling piping situ conditions. Studies have revealed that commercial transducers may satisfy LMFBR ultrasonic pipe inspection applications: The test system evaluation included transducers and wedge coupling and fluid coupling materials which exhibited acceptable performance at temperatures to 2300C. Results are presented that demonstrate the feasibility of ultrasonic inspection of components immersed in sodium at temperatures to 2600C. (UK)

  14. Ultrasonic wave propagation in powders

    Science.gov (United States)

    Al-Lashi, R. S.; Povey, M. J. W.; Watson, N. J.

    2018-05-01

    Powder clumps (cakes) has a significant effect on the flowability and stability of powders. Powder caking is mainly caused by moisture migration due to wetting and environmental (temperature and humidity) changes. The process of moisture migration caking involves creating liquid bridges between the particles during condensation which subsequently harden to form solid bridges. Therefore, an effective and reliable technique is required to quantitatively and non-invasively monitor caking kinetics and effective stiffness. This paper describes two ultrasonic instruments (ultrasonic velocity pulse and airborne ultrasound systems) that have been used to monitor the caking phenomenon. Also, it discusses the relationship between the ultrasonic velocity and attenuation measurements and tracking caking kinetics and the effective stiffness of powders.

  15. The dynamic behavior of microbubbles during long ultrasound tone-burst excitation: mechanistic insights into ultrasound-microbubble mediated therapeutics using high-speed imaging and cavitation detection

    Science.gov (United States)

    Pacella, John J.; Villanueva, Flordeliza S.

    2015-01-01

    Ultrasound (US)-microbubble (MB) mediated therapies have been shown to restore perfusion and enhance drug/gene delivery. Due to the presumption that MBs do not persist during long US exposure under high acoustic pressures, most schemes utilize short US pulses when a high US pressure is employed. However, we recently observed an enhanced thrombolytic effect using long US pulses at high acoustic pressures. Therefore we explored the fate of MBs during long tone-burst exposures (5 ms) at various acoustic pressures and MB concentrations via direct high-speed optical observation and passive cavitation detection. MBs first underwent stable or inertial cavitation depending on the acoustic pressure, and then formed gas-filled clusters that continued to oscillate, break up, and form new clusters. Cavitation detection confirmed continued, albeit diminishing acoustic activity throughout the 5-ms US excitation. These data suggest that persisting cavitation activity during long tone-bursts may confer additional therapeutic effects. PMID:26603628

  16. Performance of ultrasonic and hydrogen peroxide technologies in removal of Bisphenol A from Aqueous solution

    Directory of Open Access Journals (Sweden)

    MH Dehghani

    2016-05-01

    Full Text Available Introduction:BPA is a non biodegradable antioxidant that has greatly hazardous for human and animals health. and Because of the eliminating alone fewness amount of the BPA during the wastewater treatment, wastewater that contains BPA can be source of pollution in aqueous solution. The objective of this study was Performance of ultrasonic and H2O2 technologies in removal of BPA from aqueous solution. Methods:Experiments of sonochemical was carried out with use of unit ultrasonicator (Elma, which in the two power 300 and 500W, frequencies at 35 and 130KHz. Hydrogen Peroxide in concentrations at 5, 15 and 30mg/lit was applied. Initial concentration BPA at limits 2, 5, 20 and 50 mg/lit which For measuring concentration of BPA used from Spectrometer UV/VIS Lambada 25 Perkin Elmer, Shelton unit. Results:The results demonstrated that hybrid ultrasonic and peroxide Hydrogen processes with Efficiency 98.65%,  has the highest efficiency in the removal of BPA. The most decomposition rate achieved at the frequency of 130 KHz and 500W assisted by 30mg/lit H2O2 at pH 11. Also the results demonstrated that with pH increase destruction rate BPA the increased by any three processes (ultrasonic, H2O2 and both hybrid. Conclusion:The results demonstrated that hybrid ultrasonic and peroxide Hydrogen processes can be used as a clean method and friendly environment for waters treatment are contains desirable BPA.

  17. Fast Lamb wave energy shift approach using fully contactless ultrasonic system to characterize concrete structures

    Science.gov (United States)

    Ham, Suyun; Popovics, John S.

    2015-03-01

    Ultrasonic techniques provide an effective non-destructive evaluation (NDE) method to monitor concrete structures, but the need to perform rapid and accurate structural assessment requires evaluation of hundreds, or even thousands, of measurement datasets. Use of a fully contactless ultrasonic system can save time and labor through rapid implementation, and can enable automated and controlled data acquisition, for example through robotic scanning. Here we present results using a fully contactless ultrasonic system. This paper describes our efforts to develop a contactless ultrasonic guided wave NDE approach to detect and characterize delamination defects in concrete structures. The developed contactless sensors, controlled scanning system, and employed Multi-channel Analysis of Surface Waves (MASW) signal processing scheme are reviewed. Then a guided wave interpretation approach for MASW data is described. The presence of delamination is interpreted by guided plate wave (Lamb wave) behavior, where a shift in excited Lamb mode phase velocity, is monitored. Numerically simulated and experimental ultrasonic data collected from a concrete sample with simulated delamination defects are presented, where the occurrence of delamination is shown to be associated with a mode shift in Lamb wave energy.

  18. Pipe Wall Thickness Monitoring Using Dry-Coupled Ultrasonic Waveguide Technique

    International Nuclear Information System (INIS)

    Cheong, Yong Moo; Kim, Ha Nam; Kim, Hong Pyo

    2012-01-01

    In order to monitor a corrosion or FAC (Flow Accelerated Corrosion) in a pipe, there is a need to measure pipe wall thickness at high temperature. Ultrasonic thickness gauging is the most commonly used non-destructive testing technique for wall thickness measurement. However, current commonly available ultrasonic transducers cannot withstand high temperatures, such as above 200 .deg. C. It is therefore necessary to carry out manual measurements during plant shutdowns. The current method thus reveals several disadvantages: inspection have to be performed during shutdowns with the possible consequences of prolonging down time and increasing production losses, insulation has to be removed and replaced for each manual measurement, and scaffolding has to be installed to inaccessible areas, resulting in considerable cost for interventions. It has been suggested that a structural health monitoring approach with permanently installed ultrasonic thickness gauges could have substantial benefits over current practices. The main reasons why conventional piezoelectric ultrasonic transducers cannot be used at high temperatures are that the piezo-ceramic becomes depolarized at temperature above the Curie temperature and because differential thermal expansion of the substrate, couplant, and piezoelectric materials cause failure. In this paper, a shear horizontal waveguide technique for wall thickness monitoring at high temperature is investigated. Two different designs for contact to strip waveguide are shown and the quality of output signal is compared and reviewed. After a success of acquiring high quality ultrasonic signal, experiment on the wall thickness monitoring at high temperature is planned

  19. Ultrasonic testing of a sealing construction made of salt concrete in an underground disposal facility for radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Martin; Effner, Ute Antonie; Milmann, Boris; Voelker, Christoph; Wiggenhauser, Herbert [Federal Institute for Materials Research and Testing (BAM), Berlin (Germany); Mauke, Ralf [The Federal Office for Radiation Protection, Salzgitter (Germany)

    2015-07-01

    For the closure of radioactive waste disposal facilities engineered barriers- so called ''drift seals'' are used. The purpose of these barriers is to constrain the possible infiltration of brine and to prevent the migration of radionuclides into the biosphere. In a rock salt mine a large scale in-situ experiment of a sealing construction made of salt concrete was set up to prove the technical feasibility and operability of such barriers. In order to investigate the integrity of this structure, non-destructive ultrasonic measurements were carried out. Therefore two different methods were applied at the front side of the test-barrier: 1 Reflection measurements from boreholes 2 Ultrasonic imaging by means of scanning ultrasonic echo methods This extended abstract is a short version of an article to be published in a special edition of ASCE Journal that will briefly describe the sealing construction, the application of the non-destructive ultrasonic measurement methods and their adaptation to the onsite conditions -as well as parts of the obtained results. From this a concept for the systematic investigation of possible contribution of ultrasonic methods for quality assurance of sealing structures may be deduced.

  20. Non destructive evaluation of ceramics

    International Nuclear Information System (INIS)

    Green, R.E. Jr

    1992-01-01

    While monolithic and composite ceramics have been successfully manufactured, inconsistencies in processing and the unpredictable nature of their failure have limited their use as engineering materials. The optimization of the processing and properties of ceramics and the structures, devices and systems made from them demand the innovative application of modern nondestructive materials characterization techniques to monitor and control as many stages of the production process as possible. This paper will describe the state-of-the-art of nondestructive evaluation techniques for characterization of monolithic ceramics and ceramic composites. Among the techniques to be discussed are laser ultrasonics, acoustic microscopy, thermography, microfocus and x-ray tomography, and micro-photoelasticity. Application of these and other nondestructive evaluation techniques for more effective and efficient real-time process control will result in improved product quality and reliability. 27 refs