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Sample records for high-intensity static magnetic

  1. Effects of high-intensity static magnetic fields on a root-based bioreactor system for space applications

    Science.gov (United States)

    Villani, Maria Elena; Massa, Silvia; Lopresto, Vanni; Pinto, Rosanna; Salzano, Anna Maria; Scaloni, Andrea; Benvenuto, Eugenio; Desiderio, Angiola

    2017-11-01

    Static magnetic fields created by superconducting magnets have been proposed as an effective solution to protect spacecrafts and planetary stations from cosmic radiations. This shield can deflect high-energy particles exerting injurious effects on living organisms, including plants. In fact, plant systems are becoming increasingly interesting for space adaptation studies, being useful not only as food source but also as sink of bioactive molecules in future bioregenerative life-support systems (BLSS). However, the application of protective magnetic shields would generate inside space habitats residual magnetic fields, of the order of few hundreds milli Tesla, whose effect on plant systems is poorly known. To simulate the exposure conditions of these residual magnetic fields in shielded environment, devices generating high-intensity static magnetic field (SMF) were comparatively evaluated in blind exposure experiments (250 mT, 500 mT and sham -no SMF-). The effects of these SMFs were assayed on tomato cultures (hairy roots) previously engineered to produce anthocyanins, known for their anti-oxidant properties and possibly useful in the setting of BLSS. Hairy roots exposed for periods ranging from 24 h to 11 days were morphometrically analyzed to measure their growth and corresponding molecular changes were assessed by a differential proteomic approach. After disclosing blind exposure protocol, a stringent statistical elaboration revealed the absence of significant differences in the soluble proteome, perfectly matching phenotypic results. These experimental evidences demonstrate that the identified plant system well tolerates the exposure to these magnetic fields. Results hereby described reinforce the notion of using this plant organ culture as a tool in ground-based experiments simulating space and planetary environments, in a perspective of using tomato 'hairy root' cultures as bioreactor of ready-to-use bioactive molecules during future long-term space missions.

  2. Wet high-intensity magnetic separation

    International Nuclear Information System (INIS)

    Levin, J.; Shanks, R.I.

    1980-01-01

    Miscellaneous laboratory tests (most of them on cyanide residues) were undertaken to supplement on-site pilot-plant work on wet high intensity magnetic separation (WHIMS). Initially, the main concern was with blockage of the matrix, and consideration was given to the use of a reverse-flushing system. The laboratory tests on this system were encouraging, but they were not of sufficiently long duration to be conclusive. The velocity of the pulp through the matrix is important, because it determines the capacity of the separator and the recovery obtainable. Of almost equal importance is the magnetic load, which affects the velocity of the pulp and the recovery. Typically, a recovery of 51 per cent of the uranium was reduced to one of 40 per cent as the magnetic load was increased from 25 to 100 g/l, while the pulp velocity decreased from 62 to 36 mm/s. There was some indication that, for the same pulp velocity, lower recoveries are obtained when free-fall feeding is used. Some benefit was observed in the application of WHIMS to coarsely ground ore; from a Blyvooruitzicht rod-mill product, 25 per cent of the total uranium was recovered when only 29 per cent of the rod-mill product (the finest portion) was treated. A similar recovery was made from 43 per cent of the rod-mill product from Stilfontein; a second stage of treatment after regrinding raised the overall recovery of uranium to 76,4 per cent. Recoveries of 55 and 42 per cent of the uranium were obtained in tests on two flotation tailings from Free State Geduld. In a determination of the mass magnetic susceptibilities of the constituents in a typical concentrate obtained by WHIMS, it was found that some 20 per cent of the magnetic product had a susceptibility of less than 5,4 X 10 -6 e.m.u. but contained 38 per cent of the uranium recovered by WHIMS. A few tests were conducted on different types of matrix. A matrix of spaced horizontal rods is recommended for possible future consideration [af

  3. The clinical study on high intensity zone of magnetic resonance imaging using Scolopendrid Aquacupuncture.

    Directory of Open Access Journals (Sweden)

    Jeong-a Lim

    2006-12-01

    Full Text Available Objective : This study was designed to find out the effect of scolopendrid aquacupuncture on low back pain with or without sciatica showing high intensity zone of magnetic resonance imaging. Methods : The 30 patients who had a diagnosis of high intensity zone by lumbar-MRI and admitted to Gwangju oriental medical hospital in wonkwang university from January 2005 to August 2004 were observed. The symptom of inpatients is low back pain with or without sciatica. We treated 30 patients by scolopendrid aquacupuncture besides the general conservative treatment of oriental medicine. Results and Conclusion : The scolopendrid aquacupuncture treatment led to improvement in the pain and symptom of disability as determined by all efficacy measures. After scolopendrid aquacupuncture treatment, there was improvement in VAS, ROM and SLRT. This results suggest that scolopendrid aquacupuncture is good method for treatment of low back pain with or without sciatica showing high intensity zone of magnetic resonance imaging.

  4. High intensity magnetic separation for the clean-up of a site polluted by lead metallurgy.

    Science.gov (United States)

    Sierra, C; Martínez, J; Menéndez-Aguado, J M; Afif, E; Gallego, J R

    2013-03-15

    The industrial history in the district of Linares (Spain) has had a severe impact on soil quality. Here we examined soil contaminated by lead and other heavy metals in "La Cruz" site, a brownfield affected by metallurgical residues. Initially, the presence of contaminants mainly associated with the presence of lead slag fragments mixed with the soil was evaluated. The subsequent analysis showed a quasi-uniform distribution of the pollution irrespective of the grain-size fractions. This study was accompanied by a characterization of the lead slag behavior under the presence of a magnetic field. Two main magnetic components were detected: first a ferromagnetic and/or ferrimagnetic contribution, second a paramagnetic and/or antiferromagnetic one. It was also established that the slag was composed mainly of lead spherules and iron oxides embedded in a silicate matrix. Under these conditions, the capacity of magnetic separation to remove pollutants was examined. Therefore, two high intensity magnetic separators (dry and wet devices, respectively) were used. Dry separation proved to be successful at decontaminating soil in the first stages of a soil washing plant. In contrast, wet separation was found effective as a post-process for the finer fractions. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Static devices with new permanent magnets

    International Nuclear Information System (INIS)

    Chavanne, J.; Laforest, J.; Pauthenet, R.

    1987-01-01

    The high remanence and coercivity of the new permanent magnet materials are of special interest in the static applications. High ordering temperature and are uniaxial anisotropy at the origin of their good permanent magnet properties are obtained in rare earth-transition metal compounds. Binary SmCo/sub 5/ and Sm/sub 2/Co/sub 17/ and ternary Nd/sub 2/Fe/sub 14/B compounds are the basis materials of the best permanent magnets. new concepts of calculations of static devices with these magnets can be applied: the magnetization can be considered as ridig, the density of the surface Amperian current is constant, the relative permeability is approximately 1 and the induction calculations are linear. Examples of hexapoles with Sm-Co and NdFeB magnets are described and the performances are compared. The problems of temperature behavior and corrosion resistance are underlined

  6. An improved permanent magnet quadrupole design with larger good field region for high intensity proton linacs

    Energy Technology Data Exchange (ETDEWEB)

    Mathew, Jose V., E-mail: josev.mathew@gmail.com; Rao, S.V.L.S.; Krishnagopal, S.; Singh, P.

    2013-11-01

    The Low Energy High Intensity Proton Accelerator (LEHIPA), being developed at the Bhabha Atomic Research Centre (BARC) will produce a 20 MeV, 30 mA, continuous wave (CW) proton beam. At these low velocities, space-charge forces dominate, and could lead to larger beam sizes and beam halos. Hence in the design of the focusing lattice of the LEHIPA drift tube linac (DTL) using permanent magnet quadrupoles (PMQs), a larger good field region is preferred. Here we study, using the two dimensional (2D) and three dimensional (3D) simulation codes PANDIRA and RADIA, four different types of cylindrical PMQ designs: 16-segment trapezoidal Halbach configuration, bullet-nosed geometry and 8- and 16-segment rectangular geometries. The trapezoidal Halbach geometry is used in a variety of accelerators since it provides very high field gradients in small bores, while the bullet-nosed geometry, which is a combination of the trapezoidal and rectangular designs, is used in some DTLs. This study shows that a larger good field region is possible in the 16-segment rectangular design as compared to the Halbach and bullet-nosed designs, making it more attractive for high-intensity proton linacs. An improvement in good-field region by ∼16% over the Halbach design is obtained in the optimized 16-segment rectangular design, although the field gradient is lower by ∼20%. Tolerance studies show that the rectangular segment PMQ design is substantially less sensitive to the easy axis orientation errors and hence will be a better choice for DTLs. -- Highlights: • An improved permanent magnet quadrupole (PMQ) design with larger good field region is proposed. • We investigate four PMQ designs, including the widely used Halbach and bullet nosed designs. • Analytical calculations are backed by 2D as well as 3D numerical solvers, PANDIRA and RADIA. • The optimized 16 segment rectangular PMQ design is identified to exhibit the largest good field region. • The effect of easy axis orientation

  7. An improved permanent magnet quadrupole design with larger good field region for high intensity proton linacs

    International Nuclear Information System (INIS)

    Mathew, Jose V.; Rao, S.V.L.S.; Krishnagopal, S.; Singh, P.

    2013-01-01

    The Low Energy High Intensity Proton Accelerator (LEHIPA), being developed at the Bhabha Atomic Research Centre (BARC) will produce a 20 MeV, 30 mA, continuous wave (CW) proton beam. At these low velocities, space-charge forces dominate, and could lead to larger beam sizes and beam halos. Hence in the design of the focusing lattice of the LEHIPA drift tube linac (DTL) using permanent magnet quadrupoles (PMQs), a larger good field region is preferred. Here we study, using the two dimensional (2D) and three dimensional (3D) simulation codes PANDIRA and RADIA, four different types of cylindrical PMQ designs: 16-segment trapezoidal Halbach configuration, bullet-nosed geometry and 8- and 16-segment rectangular geometries. The trapezoidal Halbach geometry is used in a variety of accelerators since it provides very high field gradients in small bores, while the bullet-nosed geometry, which is a combination of the trapezoidal and rectangular designs, is used in some DTLs. This study shows that a larger good field region is possible in the 16-segment rectangular design as compared to the Halbach and bullet-nosed designs, making it more attractive for high-intensity proton linacs. An improvement in good-field region by ∼16% over the Halbach design is obtained in the optimized 16-segment rectangular design, although the field gradient is lower by ∼20%. Tolerance studies show that the rectangular segment PMQ design is substantially less sensitive to the easy axis orientation errors and hence will be a better choice for DTLs. -- Highlights: • An improved permanent magnet quadrupole (PMQ) design with larger good field region is proposed. • We investigate four PMQ designs, including the widely used Halbach and bullet nosed designs. • Analytical calculations are backed by 2D as well as 3D numerical solvers, PANDIRA and RADIA. • The optimized 16 segment rectangular PMQ design is identified to exhibit the largest good field region. • The effect of easy axis orientation

  8. Response of Cultured Neuronal Network Activity After High-Intensity Power Frequency Magnetic Field Exposure

    Directory of Open Access Journals (Sweden)

    Atsushi Saito

    2018-03-01

    Full Text Available High-intensity and low frequency (1–100 kHz time-varying electromagnetic fields stimulate the human body through excitation of the nervous system. In power frequency range (50/60 Hz, a frequency-dependent threshold of the external electric field-induced neuronal modulation in cultured neuronal networks was used as one of the biological indicator in international guidelines; however, the threshold of the magnetic field-induced neuronal modulation has not been elucidated. In this study, we exposed rat brain-derived neuronal networks to a high-intensity power frequency magnetic field (hPF-MF, and evaluated the modulation of synchronized bursting activity using a multi-electrode array (MEA-based extracellular recording technique. As a result of short-term hPF-MF exposure (50–400 mT root-mean-square (rms, 50 Hz, sinusoidal wave, 6 s, the synchronized bursting activity was increased in the 400 mT-exposed group. On the other hand, no change was observed in the 50–200 mT-exposed groups. In order to clarify the mechanisms of the 400 mT hPF-MF exposure-induced neuronal response, we evaluated it after blocking inhibitory synapses using bicuculline methiodide (BMI; subsequently, increase in bursting activity was observed with BMI application, and the response of 400 mT hPF-MF exposure disappeared. Therefore, it was suggested that the response of hPF-MF exposure was involved in the inhibitory input. Next, we screened the inhibitory pacemaker-like neuronal activity which showed autonomous 4–10 Hz firing with CNQX and D-AP5 application, and it was confirmed that the activity was reduced after 400 mT hPF-MF exposure. Comparison of these experimental results with estimated values of the induced electric field (E-field in the culture medium revealed that the change in synchronized bursting activity occurred over 0.3 V/m, which was equivalent to the findings of a previous study that used the external electric fields. In addition, the results suggested that

  9. Dynamic T2-mapping during magnetic resonance guided high intensity focused ultrasound ablation of bone marrow

    International Nuclear Information System (INIS)

    Waspe, Adam C.; Looi, Thomas; Mougenot, Charles; Amaral, Joao; Temple, Michael; Sivaloganathan, Siv; Drake, James M.

    2012-01-01

    Focal bone tumor treatments include amputation, limb-sparing surgical excision with bone reconstruction, and high-dose external-beam radiation therapy. Magnetic resonance guided high intensity focused ultrasound (MR-HIFU) is an effective non-invasive thermotherapy for palliative management of bone metastases pain. MR thermometry (MRT) measures the proton resonance frequency shift (PRFS) of water molecules and produces accurate ( 2 , since T 2 increases linearly in fat during heating. T 2 -mapping using dual echo times during a dynamic turbo spin-echo pulse sequence enabled rapid measurement of T 2 . Calibration of T 2 -based thermal maps involved heating the marrow in a bovine femur and simultaneously measuring T 2 and temperature with a thermocouple. A positive T 2 temperature dependence in bone marrow of 20 ms/°C was observed. Dynamic T 2 -mapping should enable accurate temperature monitoring during MR-HIFU treatment of bone marrow and shows promise for improving the safety and reducing the invasiveness of pediatric bone tumor treatments.

  10. Enhanced thermal effect using magnetic nano-particles during high-intensity focused ultrasound.

    Science.gov (United States)

    Devarakonda, Surendra Balaji; Myers, Matthew R; Giridhar, Dushyanth; Dibaji, Seyed Ahmad Reza; Banerjee, Rupak Kumar

    2017-01-01

    Collateral damage and long sonication times occurring during high-intensity focused ultrasound (HIFU) ablation procedures limit clinical advancement. In this reserarch, we investigated whether the use of magnetic nano-particles (mNPs) can reduce the power required to ablate tissue or, for the same power, reduce the duration of the procedure. Tissue-mimicking phantoms containing embedded thermocouples and physiologically acceptable concentrations (0%, 0.0047%, and 0.047%) of mNPs were sonicated at acoustic powers of 5.2 W, 9.2 W, and 14.5 W, for 30 seconds. Lesion volumes were determined for the phantoms with and without mNPs. It was found that with the 0.047% mNP concentration, the power required to obtain a lesion volume of 13 mm3 can be halved, and the time required to achieve a 21 mm3 lesion decreased by a factor of 5. We conclude that mNPs have the potential to reduce damage to healthy tissue, and reduce the procedure time, during tumor ablation using HIFU.

  11. Device measures static friction of magnetic tape

    Science.gov (United States)

    Cole, P. T.

    1967-01-01

    Device measures the coefficient of static friction of magnetic tape over a range of temperatures and relative humidities. It uses a strain gage to measure the force of friction between a reference surface and the tape drawn at a constant velocity of approximately 0.0001 inch per second relative to the reference surface.

  12. Clinical significance of periventricular high intensity lesions on magnetic resonance imaging in dementia

    International Nuclear Information System (INIS)

    Kaieda, Makoto

    1991-01-01

    In this study, vascular dementia (VD, 31 cases), senile dementia of Alzheimer type (DAT, 36 cases) and mixed type dementia (14 cases) were studied by means of magnetic resonance imaging (MRI). Diagnosis of dementia was made according to DSM-III and Hachinski's ischemic score. The areas of periventricular high intensity lesions (PVH) and those of brain parenchyma were measured by digitizer which was connected to a computer. The PVH score was obtained by dividing the areas of PVH by those of brain parenchyma at the level of the body of the lateral ventricle. A multiple variable analysis was applied to the PVH scores and risk factors for dementia using Hayashi's quantification method I. The multiple correlation coefficient between the PVH and the risk factors was 0.685. The most significant correlation was found between Hachinski's ischemic score and the PVH score (partial correlation coefficient: 0.58). Significant correlations were also found between ADL and the PVH score (0.25), as well as between the Hasegawa dementia score and the PVH score (0.24). Using the student T test, it was shown that the large PVH group was significantly correlated to poor ADL, whereas the small PVH group was not. The large PVH group in VD showed lower Hasegawa score than the small PVH group. On the other hand, there was no such correlation in DAT. PVH with prolongation of T2 could exist in various pathological states irrespective of their causes. Diffuse PVH tended to be frequently observed in VD together with poor ADL. It was therefore thought that brain ischemia was the main cause of PVH. (author)

  13. Clinical significance of periventricular high intensity lesions on magnetic resonance imaging in dementia

    Energy Technology Data Exchange (ETDEWEB)

    Kaieda, Makoto [Nippon Medical School, Tokyo (Japan)

    1991-04-01

    In this study, vascular dementia (VD, 31 cases), senile dementia of Alzheimer type (DAT, 36 cases) and mixed type dementia (14 cases) were studied by means of magnetic resonance imaging (MRI). Diagnosis of dementia was made according to DSM-III and Hachinski's ischemic score. The areas of periventricular high intensity lesions (PVH) and those of brain parenchyma were measured by digitizer which was connected to a computer. The PVH score was obtained by dividing the areas of PVH by those of brain parenchyma at the level of the body of the lateral ventricle. A multiple variable analysis was applied to the PVH scores and risk factors for dementia using Hayashi's quantification method I. The multiple correlation coefficient between the PVH and the risk factors was 0.685. The most significant correlation was found between Hachinski's ischemic score and the PVH score (partial correlation coefficient: 0.58). Significant correlations were also found between ADL and the PVH score (0.25), as well as between the Hasegawa dementia score and the PVH score (0.24). Using the student T test, it was shown that the large PVH group was significantly correlated to poor ADL, whereas the small PVH group was not. The large PVH group in VD showed lower Hasegawa score than the small PVH group. On the other hand, there was no such correlation in DAT. PVH with prolongation of T2 could exist in various pathological states irrespective of their causes. Diffuse PVH tended to be frequently observed in VD together with poor ADL. It was therefore thought that brain ischemia was the main cause of PVH. (author).

  14. Histopathology of breast cancer after magnetic resonance-guided high-intensity focused ultrasound and radiofrequency ablation

    NARCIS (Netherlands)

    Knuttel, Floor; Waaijer, Laurien; Merckel, LG; van den Bosch, Maurice A A J; Witkamp, Arjen J.; Deckers, Roel; van Diest, Paul J.

    AIMS: Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) ablation and radiofrequency ablation (RFA) are being researched as possible substitutes for surgery in breast cancer patients. The histopathological appearance of ablated tissue has not been studied in great detail. This

  15. Effects of magnetic resonance-guided high-intensity focused ultrasound ablation on bone mechanical properties and modeling

    NARCIS (Netherlands)

    Yeoh, S.Y.; Arias Moreno, A.J.; Rietbergen, van B.; Hoeve, ter N.D.; Diest, van P.J.; Grull, H.

    2015-01-01

    Background Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) is a promising technique for palliative treatment of bone pain. In this study, the effects of MR-HIFU ablation on bone mechanics and modeling were investigated. Methods A total of 12 healthy rat femurs were ablated

  16. Orienting Paramecium with intense static magnetic fields

    Science.gov (United States)

    Valles, James M., Jr.; Guevorkian, Karine; Quindel, Carl

    2004-03-01

    Recent experiments on cell division suggest the application of intense static magnetic fields as a novel tool for the manipulation of biological systems [1]. The magnetic field appears to couple to the intrinsic anisotropies in the diamagnetic components of the cells. Here, we present measurements of the intrinsic average diamagnetic anisotropy of the whole single celled ciliate, Paramecium Caudatum. Magnetic fields, 2.5 T Paramecium Caudatum that were suspended in a density matched medium. The organisms align with their long axis parallel to the applied magnetic field. Their intrinsic diamagnetic anisotropy is 3x10-11 in cgs units. We will discuss the implications of these results for employing magnetic fields to probe the behavior of swimming Paramecium. [1] J. M. Valles, Jr. et al., Expt. Cell Res.274, 112-118 (2002).

  17. Static Magnetic Cloak without a Superconductor

    Science.gov (United States)

    Jiang, Wei; Ma, Yungui; He, Sailing

    2018-05-01

    Similar to its electromagnetic counterpart, magnetic cloaking also has very important technological applications. However, the traditional method to build a static magnetic cloak requires the use of superconducting materials as the diamagnetic component, which seriously limits the practical potential because of the cryogenic condition. We show that a diamagnetic active current boundary combined with a high-permeability magnetic inner shell (MIS) can be designed to solve this problem, rendering an ideal magnetic cloaking effect at zero frequency. We first theoretically prove that a current boundary could magnetically behave as a superconductor to external observers. Based on this phenomena, we introduce a high-permeability MIS made of magnetically ultrasoft metallic sheets (permeability μ >103 ) and experimentally prove that the bilayer combination can exactly balance out the disturbance to the external probing field and, meanwhile, have a large invisible inner space. We also show that the active boundary currents can be accordingly configured to overcome the permeability and frequency band limits, leading to a robust cloak over the entire quasistatic frequency region. Our work creates an efficient way to circumvent the traditional limits of metamaterials to build magnetic cloaks for ultralow frequencies. The active-passive hybrid approach could be generally extended to yield other artificial magnetic devices or systems as well.

  18. Magnetic resonance–guided interstitial high-intensity focused ultrasound for brain tumor ablation

    Science.gov (United States)

    MacDonell, Jacquelyn; Patel, Niravkumar; Rubino, Sebastian; Ghoshal, Goutam; Fischer, Gregory; Burdette, E. Clif; Hwang, Roy; Pilitsis, Julie G.

    2018-01-01

    Currently, treatment of brain tumors is limited to resection, chemotherapy, and radiotherapy. Thermal ablation has been recently explored. High-intensity focused ultrasound (HIFU) is being explored as an alternative. Specifically, the authors propose delivering HIFU internally to the tumor with an MRI-guided robotic assistant (MRgRA). The advantage of the authors’ interstitial device over external MRI-guided HIFU (MRgHIFU) is that it allows for conformal, precise ablation and concurrent tissue sampling. The authors describe their workflow for MRgRA HIFU delivery. PMID:29385926

  19. One session of high-intensity interval training (HIIT) every 5 days, improves muscle power but not static balance in lifelong sedentary ageing men: A randomized controlled trial.

    Science.gov (United States)

    Sculthorpe, Nicholas F; Herbert, Peter; Grace, Fergal

    2017-02-01

    Declining muscle power during advancing age predicts falls and loss of independence. High-intensity interval training (HIIT) may improve muscle power, but remains largely unstudied in ageing participants. This randomized controlled trial (RCT) investigated the efficacy of a low-frequency HIIT (LfHIIT) intervention on peak muscle power (peak power output [PPO]), body composition, and balance in lifelong sedentary but otherwise healthy males. Thirty-three lifelong sedentary ageing men were randomly assigned to either intervention (INT; n = 22, age 62.3 ± 4.1 years) or control (n = 11, age 61.6 ± 5.0 years) who were both assessed at 3 distinct measurement points (phase A), after 6 weeks of conditioning exercise (phase B), and after 6 weeks of HIIT once every 5 days in INT (phase C), where control remained inactive throughout the study. Static balance remained unaffected, and both absolute and relative PPO were not different between groups at phases A or B, but increased significantly in INT after LfHIIT (P < 0.01). Lean body mass displayed a significant interaction (P < 0.01) due to an increase in INT between phases B and C (P < 0.05). 6 weeks of LfHIIT exercise feasible and effective method to induce clinically relevant improvements in absolute and relative PPO, but does not improve static balance in sedentary ageing men.

  20. Experimental platform for investigations of high-intensity laser plasma interactions in the magnetic field of a pulsed power generator

    Science.gov (United States)

    Ivanov, V. V.; Maximov, A. V.; Swanson, K. J.; Wong, N. L.; Sarkisov, G. S.; Wiewior, P. P.; Astanovitskiy, A. L.; Covington, A. M.

    2018-03-01

    An experimental platform for the studying of high-intensity laser plasma interactions in strong magnetic fields has been developed based on the 1 MA Zebra pulsed power generator coupled with the 50-TW Leopard laser. The Zebra generator produces 100-300 T longitudinal and transverse magnetic fields with different types of loads. The Leopard laser creates plasma at an intensity of 1019 W/cm2 in the magnetic field of coil loads. Focusing and targeting systems are integrated in the vacuum chamber of the pulsed power generator and protected from the plasma debris and strong mechanical shock. The first experiments with plasma at laser intensity >2 × 1018 W/cm2 demonstrated collimation of the laser produced plasma in the axial magnetic field strength >100 T.

  1. The selection of a matrix for the recovery of uranium by wet high-intensity magnetic separation

    International Nuclear Information System (INIS)

    Svoboda, J.

    1985-01-01

    The proper choice of a suitable matrix for high-intensity magnetic separation is of the utmost importance, since the geometry and size of the matrix play decisive roles in the achievement of optimum separation conditions. In relatively simple filtration applications, the matrix must offer a high efficiency of collision with suspended particles, a high probability of retention of intercepted particles, and high loading capacity. Also, it must be easily cleaned. The results obtained by the use of theoretical models of magnetic separation fail to agree with the experimental results for basic parameters like the ratio of particle size to matrix size, the length of the matrix, and the magnetic properties of the matrix material. Preconceived ideas about the matrix often lead to the erroneous choice of a matrix, and hence to its unsatisfactory performance during magnetic separation. The potential value of high-intensity magnetic separation as applied to the recovery of uranium and gold from leach residues and in association with the development of a large-scale magnetic separator to be used for the same purpose led to the present investigation in which a wide spectrum of matrix shapes and sizes were tested. It was found that the optimum recovery and selectivity of separation are obtained at a ratio of particle size to matrix-element size ranging from 200 to 300. The use of these matrices also results in a low degree of mechanical entrapment, particularly of coarser particles, for which straining plays a significant role for fine matrices. It was also found that the magnetization of a matrix plays a minor role, contrary to the theoretical predictions. Furthermore, the effects of matrix height, matrix loading, and scalping of the pulp by paramagnetic matrices were evaluated for various types of matrices

  2. Two-stage continuous process of methyl ester from high free fatty acid mixed crude palm oil using static mixer coupled with high-intensity of ultrasound

    International Nuclear Information System (INIS)

    Somnuk, Krit; Smithmaitrie, Pruittikorn; Prateepchaikul, Gumpon

    2013-01-01

    Highlights: • Mixed crude palm oil was used in the two-step continuous process. • Two-step continuous process was performed using static mixer coupled with ultrasound. • The maximum obtained yield was 92.5 vol.% after the purification process. • The residence time less than 20 s was achieved in ultrasonic reactors. - Abstract: The two-stage continuous process of methyl ester from high free fatty acid (FFA) mixed crude palm oil (MCPO) was performed by using static mixer coupled with high-intensity of ultrasound. The 2 × 1000 W ultrasonic homogenizers were operated at 18 kHz frequency in the 2 × 100 mL continuous reactors. For the first-step, acid-catalyzed esterification was employed with 18 vol.% of methanol, 2.7 vol.% of sulfuric acid, 60 °C of temperature, and 20 L h −1 of MCPO flow rate, for reducing the acid value from 28 mg KOH g −1 to less than 2 mg KOH g −1 . For the second-step, base-catalyzed transesterification was carried out under 18 vol.% of methanol, 8 g KOH L −1 of oil, and 20 L h −1 of esterified oil flow rate at 30 °C. The high yields of esterified oil and crude biodiesel were attained within the residence time of less than 20 s in the ultrasonic reactors. The yields of each stage process were: 103.3 vol.% of esterified oil, 105.4 vol.% of crude biodiesel, and 92.5 vol.% of biodiesel when compared with 100 vol.% MCPO. The quality of the biodiesel meets the specification of biodiesel standard in Thailand

  3. One session of high-intensity interval training (HIIT) every 5 days, improves muscle power but not static balance in lifelong sedentary ageing men

    Science.gov (United States)

    Sculthorpe, Nicholas F.; Herbert, Peter; Grace, Fergal

    2017-01-01

    Abstract Background: Declining muscle power during advancing age predicts falls and loss of independence. High-intensity interval training (HIIT) may improve muscle power, but remains largely unstudied in ageing participants. Methods: This randomized controlled trial (RCT) investigated the efficacy of a low-frequency HIIT (LfHIIT) intervention on peak muscle power (peak power output [PPO]), body composition, and balance in lifelong sedentary but otherwise healthy males. Methods: Thirty-three lifelong sedentary ageing men were randomly assigned to either intervention (INT; n = 22, age 62.3 ± 4.1 years) or control (n = 11, age 61.6 ± 5.0 years) who were both assessed at 3 distinct measurement points (phase A), after 6 weeks of conditioning exercise (phase B), and after 6 weeks of HIIT once every 5 days in INT (phase C), where control remained inactive throughout the study. Results: Static balance remained unaffected, and both absolute and relative PPO were not different between groups at phases A or B, but increased significantly in INT after LfHIIT (P balance in sedentary ageing men. PMID:28178145

  4. Development of radiation-resistant magnet coils for high-intensity beam lines

    Science.gov (United States)

    Tanaka, K. H.; Yamanoi, Y.; Noumi, H.; Takasaki, M.; Saitoh, Y.; Kato, K.; Yokoi, T.; Tsukada, S.; Tanno, H.

    1994-07-01

    In connection with the Japanese Hadron Facility (JHF) project, the development of new types of radiation-resistant magnet coils has been continued at KEK. One major program is the design and production of a mineral insulation cable (MIC) with a larger maximum current. We have already developed a 2000A-class MIC having a square-cross-section hollow conductor. A sample magnet coil was fabricated with this MIC. Tests of its stability and reliability are under progress. We are now planning to develop a 3000A-class MIC. The other program is R/D work on a completely inorganic wrapping insulation material which can be used like the usual type glass-fiber tape pre-impregnated with epoxy-resin. After tests of the mechanical strength and electric insulation of many combinations of tapes and bonds, we found a pure (99%) alumina-fiber tape pre-impregnated with inorganic cement that is suitable for a magnet coil insulator after thermal curing.

  5. Transformation magneto-statics and illusions for magnets

    Science.gov (United States)

    Sun, Fei; He, Sailing

    2014-10-01

    Based on the form-invariant of Maxwell's equations under coordinate transformations, we extend the theory of transformation optics to transformation magneto-statics, which can design magnets through coordinate transformations. Some novel DC magnetic field illusions created by magnets (e.g. rescaling magnets, cancelling magnets and overlapping magnets) are designed and verified by numerical simulations. Our research will open a new door to designing magnets and controlling DC magnetic fields.

  6. Performance of an industrial wet high-intensity magnetic separator for the recovery of gold and uranium

    Energy Technology Data Exchange (ETDEWEB)

    Corrans, I.J.; Liddell, K.S.; Dunne, R.C. (Council for Mineral Technology, Randburg (South Africa). Ore-dressing Div.); Gilbert, W.A. (General Mining Union Corp. Ltd., Johannesburg (South Africa))

    1984-03-01

    After bench-scale and pilot-plant tests in which it was shown that wet high-intensity magnetic separation (WHIMS) can achieve good recoveries of gold and uranium from Witwatersrand residues, a production-size machine was installed at a gold mine. The mechanical and metallurgical performance of this machine have been satisfactory, and the economics of the process are attractive. WHIMS can be combined with other unit operations like flotation for the optimization of overall gold and uranium recoveries. This concept is shown to be relevant, not only to operations for the retreatment of tailings, but to processes for the treatment of coarser material. In the latter, there is a saving in energy consumption compared with the energy required for the fine grinding of the total feed, and a material suitable for underground backfill can be produced. Improved, more cost-effective WHIMS machines currently under development are also described.

  7. Targeted Vessel Ablation for More Efficient Magnetic Resonance-Guided High-Intensity Focused Ultrasound Ablation of Uterine Fibroids

    Energy Technology Data Exchange (ETDEWEB)

    Voogt, Marianne J., E-mail: m.voogt@umcutrecht.nl [University Medical Center Utrecht, Department of Radiology (Netherlands); Stralen, Marijn van [University Medical Center Utrecht, Image Sciences Institute (Netherlands); Ikink, Marlijne E. [University Medical Center Utrecht, Department of Radiology (Netherlands); Deckers, Roel; Vincken, Koen L.; Bartels, Lambertus W. [University Medical Center Utrecht, Image Sciences Institute (Netherlands); Mali, Willem P. Th. M.; Bosch, Maurice A. A. J. van den [University Medical Center Utrecht, Department of Radiology (Netherlands)

    2012-10-15

    Purpose: To report the first clinical experience with targeted vessel ablation during magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) treatment of symptomatic uterine fibroids. Methods: Pretreatment T1-weighted contrast-enhanced magnetic resonance angiography was used to create a detailed map of the uterine arteries and feeding branches to the fibroids. A three-dimensional overlay of the magnetic resonance angiography images was registered on 3D T2-weighted pretreatment imaging data. Treatment was focused primarily on locations where supplying vessels entered the fibroid. Patients were followed 6 months after treatment with a questionnaire to assess symptoms and quality of life (Uterine Fibroid Symptom and Quality of Life) and magnetic resonance imaging to quantify shrinkage of fibroid volumes. Results: In two patients, three fibroids were treated with targeted vessel ablation during MR-HIFU. The treatments resulted in almost total fibroid devascularization with nonperfused volume to total fibroid volume ratios of 84, 68, and 86%, respectively, of treated fibroids. The predicted ablated volumes during MR-HIFU in patients 1 and 2 were 45, 40, and 82 ml, respectively, while the nonperfused volumes determined immediately after treatment were 195, 92, and 190 ml respectively, which is 4.3 (patient 1) and 2.3 (patient 2) times higher than expected based on the thermal dose distribution. Fibroid-related symptoms reduced after treatment, and quality of life improved. Fibroid volume reduction ranged 31-59% at 6 months after treatment. Conclusion: Targeted vessel ablation during MR-HIFU allowed nearly complete fibroid ablation in both patients. This technique may enhance the use of MR-HIFU for fibroid treatment in clinical practice.

  8. Interaction mechanisms and biological effects of static magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Tenforde, T.S.

    1994-06-01

    Mechanisms through which static magnetic fields interact with living systems are described and illustrated by selected experimental observations. These mechanisms include electrodynamic interactions with moving, ionic charges (blood flow and nerve impulse conduction), magnetomechanical interactions (orientation and translation of molecules structures and magnetic particles), and interactions with electronic spin states in charge transfer reactions (photo-induced electron transfer in photosynthesis). A general summary is also presented of the biological effects of static magnetic fields. There is convincing experimental evidence for magnetoreception mechanisms in several classes of lower organisms, including bacteria and marine organisms. However, in more highly evolved species of animals, there is no evidence that the interactions of static magnetic fields with flux densities up to 2 Tesla (1 Tesla [T] = 10{sup 4} Gauss) produce either behavioral or physiolocical alterations. These results, based on controlled studies with laboratory animals, are consistent with the outcome of recent epidemiological surveys on human populations exposed occupationally to static magnetic fields.

  9. Fluorescent lamp with static magnetic field generating means

    Science.gov (United States)

    Moskowitz, P.E.; Maya, J.

    1987-09-08

    A fluorescent lamp wherein magnetic field generating means (e.g., permanent magnets) are utilized to generate a static magnetic field across the respective electrode structures of the lamp such that maximum field strength is located at the electrode's filament. An increase in efficacy during operation has been observed. 2 figs.

  10. Non-invasive treatment efficacy evaluation for high-intensity focused ultrasound therapy using magnetically induced magnetoacoustic measurement

    Science.gov (United States)

    Guo, Gepu; Wang, Jiawei; Ma, Qingyu; Tu, Juan; Zhang, Dong

    2018-04-01

    Although the application of high intensity focused ultrasound (HIFU) has been demonstrated to be a non-invasive treatment technology for tumor therapy, the real-time temperature monitoring is still a key issue in the practical application. Based on the temperature-impedance relation, a fixed-point magnetically induced magnetoacoustic measurement technology of treatment efficacy evaluation for tissue thermocoagulation during HIFU therapy is developed with a sensitive indicator of critical temperature monitoring in this study. With the acoustic excitation of a focused transducer in the magnetoacoustic tomography with the magnetic induction system, the distributions of acoustic pressure, temperature, electrical conductivity, and acoustic source strength in the focal region are simulated, and the treatment time dependences of the peak amplitude and the corresponding amplitude derivative under various acoustic powers are also achieved. It is proved that the strength peak of acoustic sources is generated by tissue thermocoagulation with a sharp conductivity variation. The peak amplitude of the transducer collected magnetoacoustic signal increases accordingly along with the increase in the treatment time under a fixed acoustic power. When the temperature in the range with the radial and axial widths of about ±0.46 mm and ±2.2 mm reaches 69 °C, an obvious peak of the amplitude derivative can be achieved and used as a sensitive indicator of the critical status of treatment efficacy. The favorable results prove the feasibility of real-time non-invasive temperature monitoring and treatment efficacy evaluation for HIFU ablation using the magnetically induced magnetoacoustic measurement, and might provide a new strategy for accurate dose control during HIFU therapy.

  11. Lifetime of anode polymer in magnetically insulated ion diodes for high-intensity pulsed ion beam generation

    International Nuclear Information System (INIS)

    Zhu, X. P.; Dong, Z. H.; Han, X. G.; Xin, J. P.; Lei, M. K.

    2007-01-01

    Generation of high-intensity pulsed ion beam (HIPIB) has been studied experimentally using polyethylene as the anode polymer in magnetically insulated ion diodes (MIDs) with an external magnetic field. The HIPIB is extracted from the anode plasma produced during the surface discharging process on polyethylene under the electrical and magnetic fields in MIDs, i.e., high-voltage surface breakdown (flashover) with bombardments by electrons. The surface morphology and the microstructure of the anode polymer are characterized using scanning electron microscopy and differential scanning calorimetry, respectively. The surface roughening of the anode polymer results from the explosive release of trapped gases or newly formed gases under the high-voltage discharging, leaving fractured surfaces with bubble formation. The polyethylene in the surface layer degrades into low-molecular-weight polymers such as polyethylene wax and paraffin under the discharging process. Both the surface roughness and the fraction of low molecular polymers apparently increase as the discharging times are prolonged for multipulse HIPIB generation. The changes in the surface morphology and the composition of anode polymer lead to a noticeable decrease in the output of ion beam intensity, i.e., ion current density and diode voltage, accompanied with an increase in instability of the parameters with the prolonged discharge times. The diode voltage (or surface breakdown voltage of polymer) mainly depends on the surface morphology (or roughness) of anode polymers, and the ion current density on the composition of anode polymers, which account for the two stages of anode polymer degradation observed experimentally, i.e., stage I which has a steady decrease of the two parameters and stage II which shows a slow decrease, but with an enhanced fluctuation of the two parameters with increasing pulses of HIPIB generation

  12. Dynamics and structure of self-generated magnetics fields on solids following high contrast, high intensity laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Albertazzi, B. [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); INRS-EMT, 1650 bd L. Boulet, J3X1S2, Varennes, Québec (Canada); Graduate School of Engineering, University of Osaka, Suita, Osaka 565-087 (Japan); Chen, S. N.; Fuchs, J., E-mail: julien.fuchs@polytechnique.fr [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); Institute of Applied Physics, 46 Ulyanov Street, 603950 Nizhny Novgorod (Russian Federation); Antici, P. [INRS-EMT, 1650 bd L. Boulet, J3X1S2, Varennes, Québec (Canada); Dept. SBAI, Universita di Roma “La Sapienza,” Via A. Scarpa 14, 00161 Rome (Italy); Böker, J.; Swantusch, M.; Willi, O. [Institut für Laser-und Plasmaphysik, Heinrich-Heine-Universität, Düsseldorf (Germany); Borghesi, M. [School of Mathematics and Physics, The Queen' s University, Belfast (United Kingdom); Breil, J.; Feugeas, J. L.; Nicolaï, Ph.; Tikhonchuk, V. T.; D' Humières, E. [CELIA, University of Bordeaux - CNRS - CEA, 33405 Talence (France); Dervieux, V.; Nakatsutsumi, M.; Romagnagni, L. [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); Lancia, L. [Dept. SBAI, Universita di Roma “La Sapienza,” Via A. Scarpa 14, 00161 Rome (Italy); Shepherd, R. [LLNL, East Av., Livermore, California 94550 (United States); Sentoku, Y. [Department of Physics, University of Nevada, Reno, Nevada 89557-0058 (United States); Starodubtsev, M. [Institute of Applied Physics, 46 Ulyanov Street, 603950 Nizhny Novgorod (Russian Federation); and others

    2015-12-15

    The dynamics of self-generated magnetic B-fields produced following the interaction of a high contrast, high intensity (I > 10{sup 19 }W cm{sup −2}) laser beam with thin (3 μm thick) solid (Al or Au) targets is investigated experimentally and numerically. Two main sources drive the growth of B-fields on the target surfaces. B-fields are first driven by laser-generated hot electron currents that relax over ∼10–20 ps. Over longer timescales, the hydrodynamic expansion of the bulk of the target into vacuum also generates B-field induced by non-collinear gradients of density and temperature. The laser irradiation of the target front side strongly localizes the energy deposition at the target front, in contrast to the target rear side, which is heated by fast electrons over a much larger area. This induces an asymmetry in the hydrodynamic expansion between the front and rear target surfaces, and consequently the associated B-fields are found strongly asymmetric. The sole long-lasting (>30 ps) B-fields are the ones growing on the target front surface, where they remain of extremely high strength (∼8–10 MG). These B-fields have been recently put by us in practical use for focusing laser-accelerated protons [B. Albertazzi et al., Rev. Sci. Instrum. 86, 043502 (2015)]; here we analyze in detail their dynamics and structure.

  13. Wet high-intensity magnetic separation for the concentration of Witwatersrand gold-uranium ores and residues

    International Nuclear Information System (INIS)

    Corrans, I.J.; Levin, J.

    1979-01-01

    Wet high-intensity magnetic separation (WHIMS) for the concentration of gold and uranium was tested on many Witwatersrand cyanidation residues, and on some ores and flotation tailings. The results varied, but many indicated recoveries of over 60 per cent of the gold and uranium. The main source of loss is the inefficiency of WHIMS for material of smaller particle size than 20μm. The recoveries in the continuous tests were lower than those in the batch tests. The continuous tests indicated an operational difficulty that could be experienced in practice, namely the tendency for wood chips and ferromagnetic particles to block the matrix of the separator. It was decided that a solution to the problem lies in the modification of the separator to allow continuous removal of the matrix for cleaning. A system has been developed for this purpose and is being demonstrated on a pilot-plant scale. Promising results were obtained in tests on a process that combines a coarse grind, gravity concentration, and WHIMS. In the gravity-concentration step, considerable recoveries, generally over 50 per cent, of high-grade pyrite were obtained, together with high recoveries of gold and moderate, but possibly important, recoveries of uranium. A simple model describing the operation of the WHIMS machine in terms of the operating parameters is described. This should reduce the amount of empirical testwork required for the optimization of operating conditions and should provide a basis for scale-up calculations. The economics of the WHIMS process is discussed [af

  14. Dynamic T{sub 2}-mapping during magnetic resonance guided high intensity focused ultrasound ablation of bone marrow

    Energy Technology Data Exchange (ETDEWEB)

    Waspe, Adam C.; Looi, Thomas; Mougenot, Charles; Amaral, Joao; Temple, Michael; Sivaloganathan, Siv; Drake, James M. [Centre for Image Guided Innovation and Therapeutic Intervention, The Hospital for Sick Children, Toronto, ON, M5G 1X8 (Canada); Philips Healthcare Canada, Markham, ON, L6C 2S3 (Canada); Centre for Image Guided Innovation and Therapeutic Intervention, The Hospital for Sick Children, Toronto, ON, M5G 1X8 (Canada); Department of Applied Mathematics, University of Waterloo, Waterloo, ON, N2L 3G1 (Canada); Centre for Image Guided Innovation and Therapeutic Intervention, The Hospital for Sick Children, Toronto, ON, M5G 1X8 (Canada)

    2012-11-28

    Focal bone tumor treatments include amputation, limb-sparing surgical excision with bone reconstruction, and high-dose external-beam radiation therapy. Magnetic resonance guided high intensity focused ultrasound (MR-HIFU) is an effective non-invasive thermotherapy for palliative management of bone metastases pain. MR thermometry (MRT) measures the proton resonance frequency shift (PRFS) of water molecules and produces accurate (<1 Degree-Sign C) and dynamic (<5s) thermal maps in soft tissues. PRFS-MRT is ineffective in fatty tissues such as yellow bone marrow and, since accurate temperature measurements are required in the bone to ensure adequate thermal dose, MR-HIFU is not indicated for primary bone tumor treatments. Magnetic relaxation times are sensitive to lipid temperature and we hypothesize that bone marrow temperature can be determined accurately by measuring changes in T{sub 2}, since T{sub 2} increases linearly in fat during heating. T{sub 2}-mapping using dual echo times during a dynamic turbo spin-echo pulse sequence enabled rapid measurement of T{sub 2}. Calibration of T{sub 2}-based thermal maps involved heating the marrow in a bovine femur and simultaneously measuring T{sub 2} and temperature with a thermocouple. A positive T{sub 2} temperature dependence in bone marrow of 20 ms/ Degree-Sign C was observed. Dynamic T{sub 2}-mapping should enable accurate temperature monitoring during MR-HIFU treatment of bone marrow and shows promise for improving the safety and reducing the invasiveness of pediatric bone tumor treatments.

  15. Biological interactions and human health effects of static magnetic fields

    International Nuclear Information System (INIS)

    Tenforde, T.S.

    1994-09-01

    Mechanisms through which static magnetic fields interact with living systems will be described and illustrated by selected experimental observations. These mechanisms include electrodynamic interactions with moving ionic charges (blood flow and nerve impulse conduction), magnetomechanical interactions (orientation and translation of molecular structures and magnetic particles), and interactions with electronic spin states in charge transfer reactions (photo-induced electron transfer in photosynthesis). A general summary will also be presented of the biological effects of static magnetic fields studied in the laboratory and in natural settings. One aspect of magnetic field effects that merits special concern is their influence on implanted medical electronic devices such as cardiac pacemakers. Several extensive studies have demonstrated closure of the reed switch in pacemakers exposed to relatively weak static magnetic fields, thereby causing them to revert to an asynchronous mode of operation that is potentially hazardous. Recommendations for human exposure limits are provided

  16. Enhancement of sedimentation and coagulation with static magnetic field

    Science.gov (United States)

    Zieliński, Marcin; Dębowski, Marcin; Hajduk, Anna; Rusanowska, Paulina

    2017-11-01

    The static magnetic field can be an alternative method for wastewater treatment. It has been proved that this physical factor, accelerates the biochemical processes, catalyzes advanced oxidation, intensifies anaerobic and aerobic processes or reduces swelling of activated sludge. There are also reports proving the positive impact of the static magnetic field on the coagulation and sedimentation, as well as the conditioning and dewatering of sludge. In order to be applied in larger scale the published results should be verified and confirmed. In the studies, the enhancement of sedimentation by the static magnetic field was observed. The best sedimentation was noted in the experiment, where magnetizers were placed on activated sludge bioreactor and secondary settling tank. No effect of the static magnetic field on coagulation with the utilization of PIX 113 was observed. However, the static magnetic field enhanced coagulation with the utilization of PAX-XL9. The results suggest that increased sedimentation of colloids and activated sludge, can in practice mean a reduction in the size of the necessary equipment for sedimentation with an unchanged efficiency of the process.

  17. Static magnetic forces and torques in ATLAS

    International Nuclear Information System (INIS)

    Morozov, N.A.; Samsonov, E.V.; Vorozhtsov, S.B.

    1998-01-01

    The magnetic forces acting on the various metallic objects around the ATLAS detector, are the subject of the given paper. A system designer could use the information on global forces and torque acting on various components, obtained in this report, to optimize them. The results of force calculations could also serve as additional criteria for the replacement of the magnetic baseline material of various structures by nonmagnetic ones

  18. Vitamins and glucose metabolism: The role of static magnetic fields.

    Science.gov (United States)

    Lahbib, Aïda; Ghodbane, Soumaya; Sakly, Mohsen; Abdelmelek, Hafedh

    2014-12-01

    This review focuses on our own data and other data from the literature of static magnetic fields (SMF) bioeffects and vitamins and glucose metabolism. Three main areas of investigation have been covered: Static magnetic field and glucose metabolism, static magnetic field and vitamins and the role of vitamins on glucose metabolism. Considering these articles comprehensively, the conclusions are as follows: The primary cause of changes in cells after incubation in external SMF is disruption of free radical metabolism and elevation of their concentration. Such disruption causes oxidative stress leading to an unsteadiness of glucose level and insulin release. Moreover, based on available data, it was concluded that exposure to SMF alters plasma levels of vitamin A, C, D and E; these parameters can take part in disorder of glucose homeostasis and insulin release.

  19. Magnetic Resonance–Guided High-Intensity Focused Ultrasound Hyperthermia for Recurrent Rectal Cancer: MR Thermometry Evaluation and Preclinical Validation

    Energy Technology Data Exchange (ETDEWEB)

    Chu, William, E-mail: William.Chu@sunnybrook.ca [Department of Radiation Oncology, Sunnybrook Health Sciences Centre and the University of Toronto, Toronto, Ontario (Canada); Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario (Canada); Staruch, Robert M. [Clinical Sites Research Program, Philips Research, Cambridge, Massachusetts (United States); Pichardo, Samuel [Thunder Bay Regional Research Institute, Thunder Bay, Ontario (Canada); Physics and Electrical Engineering, Lakehead University, Thunder Bay, Ontario (Canada); Tillander, Matti; Köhler, Max O. [MR Therapy, Philips Healthcare, Vantaa (Finland); Huang, Yuexi [Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario (Canada); Ylihautala, Mika [MR Therapy, Philips Healthcare, Vantaa (Finland); McGuffin, Merrylee [Department of Radiation Oncology, Sunnybrook Health Sciences Centre and the University of Toronto, Toronto, Ontario (Canada); Czarnota, Gregory [Department of Radiation Oncology, Sunnybrook Health Sciences Centre and the University of Toronto, Toronto, Ontario (Canada); Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario (Canada); Hynynen, Kullervo [Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario (Canada)

    2016-07-15

    Purpose: To evaluate the feasibility of magnetic resonance–guided high-intensity focused ultrasound (MR-HIFU) mild hyperthermia in deep tissue targets for enhancing radiation therapy and chemotherapy in the context of recurrent rectal cancer. A preclinical study was performed to evaluate the safety and performance of MR-HIFU mild hyperthermia. A prospective imaging study was performed in volunteers with rectal cancer to evaluate MR thermometry quality near the rectum and accessibility of rectal tumors using MR-HIFU. Methods and Materials: Mild hyperthermia was performed in pig thigh (9 sonications, 6 pigs) using a clinical MR-HIFU system. Targets near the rectal wall and deep thigh were evaluated. Thermal maps obtained in 6 planes every 3.2 seconds were used to control sonications in 18-mm diameter treatment regions at temperatures of 42°C to 42.5°C for 10 to 60 minutes. Volunteer imaging-only studies to assess the quality of MR thermometry (without heating) were approved by the institutional research ethics board. Anatomic and MR thermometry images were acquired in consenting volunteers with rectal cancer. In 3 of 6 study participants, rectal filling with saline was used to reduce motion-related MR thermometry artifacts near the tumor. Results: In pigs, mean target temperature matched the desired hyperthermia temperature within 0.2°C; temporal standard deviation ≤0.5°C. With optimized control thresholds, no undesired tissue damage was observed. In human volunteers, MR temperature measurements had adequate precision and stability, especially when rectal filling was used to reduce bowel motion. Conclusions: In pigs, MR-HIFU can safely deliver mild hyperthermia (41°C-43°C) to a targeted volume for 30 minutes. In humans, careful patient selection and preparation will enable adequate targeting for recurrent rectal cancers and sufficient MR temperature mapping stability to control mild hyperthermia. These results enable human trials of MR-HIFU hyperthermia.

  20. Magnetic Resonance–Guided High-Intensity Focused Ultrasound Hyperthermia for Recurrent Rectal Cancer: MR Thermometry Evaluation and Preclinical Validation

    International Nuclear Information System (INIS)

    Chu, William; Staruch, Robert M.; Pichardo, Samuel; Tillander, Matti; Köhler, Max O.; Huang, Yuexi; Ylihautala, Mika; McGuffin, Merrylee; Czarnota, Gregory; Hynynen, Kullervo

    2016-01-01

    Purpose: To evaluate the feasibility of magnetic resonance–guided high-intensity focused ultrasound (MR-HIFU) mild hyperthermia in deep tissue targets for enhancing radiation therapy and chemotherapy in the context of recurrent rectal cancer. A preclinical study was performed to evaluate the safety and performance of MR-HIFU mild hyperthermia. A prospective imaging study was performed in volunteers with rectal cancer to evaluate MR thermometry quality near the rectum and accessibility of rectal tumors using MR-HIFU. Methods and Materials: Mild hyperthermia was performed in pig thigh (9 sonications, 6 pigs) using a clinical MR-HIFU system. Targets near the rectal wall and deep thigh were evaluated. Thermal maps obtained in 6 planes every 3.2 seconds were used to control sonications in 18-mm diameter treatment regions at temperatures of 42°C to 42.5°C for 10 to 60 minutes. Volunteer imaging-only studies to assess the quality of MR thermometry (without heating) were approved by the institutional research ethics board. Anatomic and MR thermometry images were acquired in consenting volunteers with rectal cancer. In 3 of 6 study participants, rectal filling with saline was used to reduce motion-related MR thermometry artifacts near the tumor. Results: In pigs, mean target temperature matched the desired hyperthermia temperature within 0.2°C; temporal standard deviation ≤0.5°C. With optimized control thresholds, no undesired tissue damage was observed. In human volunteers, MR temperature measurements had adequate precision and stability, especially when rectal filling was used to reduce bowel motion. Conclusions: In pigs, MR-HIFU can safely deliver mild hyperthermia (41°C-43°C) to a targeted volume for 30 minutes. In humans, careful patient selection and preparation will enable adequate targeting for recurrent rectal cancers and sufficient MR temperature mapping stability to control mild hyperthermia. These results enable human trials of MR-HIFU hyperthermia.

  1. Effects of magnetic resonance-guided high-intensity focused ultrasound ablation on bone mechanical properties and modeling.

    Science.gov (United States)

    Yeo, Sin Yuin; Arias Moreno, Andrés J; van Rietbergen, Bert; Ter Hoeve, Natalie D; van Diest, Paul J; Grüll, Holger

    2015-01-01

    Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) is a promising technique for palliative treatment of bone pain. In this study, the effects of MR-HIFU ablation on bone mechanics and modeling were investigated. A total of 12 healthy rat femurs were ablated using 10 W for 46 ± 4 s per sonication with 4 sonications for each femur. At 7 days after treatments, all animals underwent MR and single photon emission computed tomography/computed tomography (SPECT/CT) imaging. Then, six animals were euthanized. At 1 month following ablations, the remaining six animals were scanned again with MR and SPECT/CT prior to euthanization. Thereafter, both the HIFU-treated and contralateral control bones of three animals from each time interval were processed for histology, whereas the remaining bones were subjected to micro-CT (μCT), three-point bending tests, and micro-finite element (micro-FE) analyses. At 7 days after HIFU ablations, edema formation around the treated bones coupled with bone marrow and cortical bone necrosis was observed on MRI and histological images. SPECT/CT and μCT images revealed presence of bone modeling through an increased uptake of (99m)Tc-MDP and formation of woven bone, respectively. At 31 days after ablations, as illustrated by imaging and histology, healing of the treated bone and the surrounding soft tissue was noted, marked by decreased in amount of tissue damage, formation of scar tissue, and sub-periosteal reaction. The results of three-point bending tests showed no significant differences in elastic stiffness, ultimate load, and yield load between the HIFU-treated and contralateral control bones at 7 days and 1 month after treatments. Similarly, the elastic stiffness and Young's moduli determined by micro-FE analyses at both time intervals were not statistically different. Multimodality imaging and histological data illustrated the presence of HIFU-induced bone damage at the cellular level, which activated the

  2. Modeling the static fringe field of superconducting magnets.

    Science.gov (United States)

    Jeglic, P; Lebar, A; Apih, T; Dolinsek, J

    2001-05-01

    The resonance frequency-space and the frequency gradient-space relations are evaluated analytically for the static fringe magnetic field of superconducting magnets used in the NMR diffusion measurements. The model takes into account the actual design of the high-homogeneity magnet coil system that consists of the main coil and the cryoshim coils and enables a precise calibration of the on-axis magnetic field gradient and the resonance frequency inside and outside of the superconducting coil. Copyright 2001 Academic Press.

  3. Interferometric methods for mapping static electric and magnetic fields

    DEFF Research Database (Denmark)

    Pozzi, Giulio; Beleggia, Marco; Kasama, Takeshi

    2014-01-01

    The mapping of static electric and magnetic fields using electron probes with a resolution and sensitivity that are sufficient to reveal nanoscale features in materials requires the use of phase-sensitive methods such as the shadow technique, coherent Foucault imaging and the Transport of Intensi......) the model-independent determination of the locations and magnitudes of field sources (electric charges and magnetic dipoles) directly from electron holographic data.......The mapping of static electric and magnetic fields using electron probes with a resolution and sensitivity that are sufficient to reveal nanoscale features in materials requires the use of phase-sensitive methods such as the shadow technique, coherent Foucault imaging and the Transport of Intensity...... on theoretical models that form the basis of the quantitative interpretation of electron holographic data. We review the application of electron holography to a variety of samples (including electric fields associated with p–n junctions in semiconductors, quantized magnetic flux in superconductors...

  4. Magnetic resonance in medicine occupational exposure to static magnetic field and radiofrequency radiation

    International Nuclear Information System (INIS)

    Zivkovic, D.; Hrnjak, M.; Ivanovic, C.

    1997-01-01

    Medical personnel working with magnetic resonance imaging (MRI) devices could be exposed to static magnetic (M) field, time-varying M fields and radiofrequency (RF) radiation. The aim of work was to investigate the density of magnetic flux of static magnetic field and the power density of RF radiation which appear in the working environment around the 0.5 T MRI unit in one hospital. The density of magnetic flux of static magnetic field was measured with Hall Effect Gauss meter - Magnetech (Great Britain), and the power density of RF radiation was measured with broadband isotropic meter - The Narda Microwave Corp. (USA). The results of measurement show that the density of magnetic flux of static M field on working places are below threshold limit of exposure and the intensities of RF radiation are far below maximum permissible level. (author)

  5. Static and low frequency electric and magnetic fields

    International Nuclear Information System (INIS)

    Thommesen, G.; Tynes, T.

    1994-01-01

    The biological effects of exposure to low frequency electric and magnetic fields are reviewed with the objective of summarizing effects directly relevant to considerations of the health and safety of exposed people. Static and low frequency electric and magnetic fields may elicit biological reactions. Whether exposure to such fields may affect human health at field strengths present in everyday or occupational life is still unsettled. There is unsufficient knowledge to establish any dose concept relevant to health risk. 196 refs., 6 tabs

  6. Magnetic fields and accretion discs around static black holes

    International Nuclear Information System (INIS)

    Dadhich, N.

    1982-01-01

    Some aspects of accretion onto static black holes immersed in a uniform magnetic field are investigated. The Ernst metric is employed to find the 'Keplerian' angular momentum distribution and the efficiency of mass-to-energy conversion for a plasma and for test particles. Under almost all physically reasonable conditions for hydrodynamic accretion the effect of the magnetic field is small. However, for test particles the effect can be very important and the efficiency can approach unity. (author)

  7. Effects of moderate static magnetic field presowing treatment on ...

    African Journals Online (AJOL)

    Improvement of seed performance by static magnetic field (SMF) constitutes a safe ecological way to substitute chemicals use. In laboratory conditions, we studied the effects of presowing seeds of two varieties of Raphanus sativus (Red: R.R, Red and White: R+W) by moderate SMF on seedlings' growth and oxidative status ...

  8. Static universe filled with spinning matter and magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Kuchowicz, Br [Warsaw Univ. (Poland). Dept. of Radiochemistry and Radiation Chemistry

    1955-08-05

    A static model of the universe is presented in the framework of Einstein-Cartan theory (ECT). The presence of aligned spins and magnetic field makes the model anisotropic. An expression is given for the radius of the universe. The model is classical and does not take into account the effects of pair creation. The validity of this model is discussed.

  9. Transcranial static magnetic field stimulation of the human motor cortex

    Science.gov (United States)

    Oliviero, Antonio; Mordillo-Mateos, Laura; Arias, Pablo; Panyavin, Ivan; Foffani, Guglielmo; Aguilar, Juan

    2011-01-01

    Abstract The aim of the present study was to investigate in healthy humans the possibility of a non-invasive modulation of motor cortex excitability by the application of static magnetic fields through the scalp. Static magnetic fields were obtained by using cylindrical NdFeB magnets. We performed four sets of experiments. In Experiment 1, we recorded motor potentials evoked by single-pulse transcranial magnetic stimulation (TMS) of the motor cortex before and after 10 min of transcranial static magnetic field stimulation (tSMS) in conscious subjects. We observed an average reduction of motor cortex excitability of up to 25%, as revealed by TMS, which lasted for several minutes after the end of tSMS, and was dose dependent (intensity of the magnetic field) but not polarity dependent. In Experiment 2, we confirmed the reduction of motor cortex excitability induced by tSMS using a double-blind sham-controlled design. In Experiment 3, we investigated the duration of tSMS that was necessary to modulate motor cortex excitability. We found that 10 min of tSMS (compared to 1 min and 5 min) were necessary to induce significant effects. In Experiment 4, we used transcranial electric stimulation (TES) to establish that the tSMS-induced reduction of motor cortex excitability was not due to corticospinal axon and/or spinal excitability, but specifically involved intracortical networks. These results suggest that tSMS using small static magnets may be a promising tool to modulate cerebral excitability in a non-invasive, painless, and reversible way. PMID:21807616

  10. Human exposure to static magnetic fields and basic precautions

    International Nuclear Information System (INIS)

    Vulevic, B.

    1999-01-01

    The development of new technologies using the static magnetic fields and their application in the last several years has increased the possibility of higher human exposure to such fields what has raised an issue of potential adverse health effects. The object of this work is to point, on the basis of the past knowledge, to the significance of the problem and therefore to contribute to its popularization. (author)

  11. Design and fabrication of a large rectangular magnetic cusp plasma source for high intensity neutral beam injectors

    International Nuclear Information System (INIS)

    Biagi, L.A.; Berkner, K.H.; Ehlers, K.W.; Paterson, J.A.; Porter, J.R.

    1979-11-01

    The design and fabrication techniques for a large, rectangular magnetic bucket plasma source are described. This source is compatible with the accelerator structures for the TFTR and DIII neutral-beam systems

  12. Magnetic Resonance-Guided High-Intensity-Focused Ultrasound for Palliation of Painful Skeletal Metastases: A Pilot Study.

    Science.gov (United States)

    Chan, Michael; Dennis, Kristopher; Huang, Yuexi; Mougenot, Charles; Chow, Edward; DeAngelis, Carlo; Coccagna, Jennifer; Sahgal, Arjun; Hynynen, Kullervo; Czarnota, Gregory; Chu, William

    2017-10-01

    Bone is one of the most common sites of metastases, with bone metastases-related pain representing a significant source of morbidity among patients with cancer. Magnetic resonance-guided focused ultrasound is a noninvasive, outpatient modality with the potential for treating painful bone metastases. The aim of this study is to report our initial experience with magnetic resonance-guided focused ultrasound in the treatment of bone metastases and our preliminary analysis of urinary cytokine levels after therapy. This was a single-center pilot study of 10 patients with metastatic cancer to investigate the feasibility of magnetic resonance-guided focused ultrasound for primary pain control in device-accessible skeletal metastases. Treatments were performed on a clinical magnetic resonance-guided focused ultrasound system using a volumetric ablation technique. Primary efficacy was assessed using Brief Pain Inventory scores and morphine equivalent daily dose intake at 3 time points: before, day 14, and day 30 after the magnetic resonance-guided focused ultrasound treatment. Urine cytokines were measured 3 days before treatment and 2 days after the treatment. Of the 10 patients, 8 were followed up 14 days and 6 were followed up 30 days after the treatment. At day 14, 3 patients (37.5%) exhibited partial pain response and 4 patients (50%) exhibited an indeterminate response, and at day 30 after the treatment, 5 patients (83%) exhibited partial pain response. No treatment-related adverse events were recorded. Of the urine cytokines measured, only Transforming growth factor alpha (TGFα) demonstrated an overall decrease, with a trend toward statistical significance ( P = .078). Our study corroborates magnetic resonance-guided focused ultrasound as a feasible and safe modality as a primary, palliative treatment for painful bone metastases and contributes to the limited body of literature using magnetic resonance-guided focused ultrasound for this clinical indication.

  13. 3D Biomimetic Magnetic Structures for Static Magnetic Field Stimulation of Osteogenesis

    OpenAIRE

    Irina Alexandra Paun; Roxana Cristina Popescu; Bogdan Stefanita Calin; Cosmin Catalin Mustaciosu; Maria Dinescu; Catalin Romeo Luculescu

    2018-01-01

    We designed, fabricated and optimized 3D biomimetic magnetic structures that stimulate the osteogenesis in static magnetic fields. The structures were fabricated by direct laser writing via two-photon polymerization of IP-L780 photopolymer and were based on ellipsoidal, hexagonal units organized in a multilayered architecture. The magnetic activity of the structures was assured by coating with a thin layer of collagen-chitosan-hydroxyapatite-magnetic nanoparticles composite. In vitro experime...

  14. Static magnetic field reduced exogenous oligonucleotide uptake by spermatozoa using magnetic nanoparticle gene delivery system

    International Nuclear Information System (INIS)

    Katebi, Samira; Esmaeili, Abolghasem; Ghaedi, Kamran

    2016-01-01

    Spermatozoa could introduce exogenous oligonucleotides of interest to the oocyte. The most important reason of low efficiency of sperm mediated gene transfer (SMGT) is low uptake of exogenous DNA by spermatozoa. The aim of this study was to evaluate the effects of static magnetic field on exogenous oligonucleotide uptake of spermatozoa using magnetofection method. Magnetic nanoparticles (MNPs) associated with the labeled oligonucleotides were used to increase the efficiency of exogenous oligonucleotide uptake by rooster spermatozoa. We used high-field/high-gradient magnet (NdFeB) to enhance and accelerate exogenous DNA sedimentation at the spermatozoa surface. Flow cytometry analysis was performed to measure viability and percentage of exogenous oligonucleotide uptake by sperm. Flow cytometry analysis showed a significant increase in exogenous oligonucleotide uptake by rooster spermatozoa (P<0.001) when spermatozoa were incubated in exogenous oligonucleotide solution and MNPs. However, by applying static magnetic field during magnetofection method, a significant decrease in exogenous oligonucleotide uptake was observed (P<0.05). Findings of this study showed that MNPs were effective to increase exogenous oligonucleotide uptake by rooster spermatozoa; however unlike others studies, static magnetic field, was not only ineffective to enhance exogenous oligonucleotide uptake by rooster spermatozoa but also led to reduction in efficiency of magnetic nanoparticles in gene transfer. - Highlights: • Core/shell type Iron oxide nanoparticles were used as a novel and efficient method. • This method increases exogenous DNA uptake by rooster spermatozoa. • Static magnetic field decreased DNA uptake by rooster spermatozoa.

  15. Static magnetic field reduced exogenous oligonucleotide uptake by spermatozoa using magnetic nanoparticle gene delivery system

    Energy Technology Data Exchange (ETDEWEB)

    Katebi, Samira; Esmaeili, Abolghasem, E-mail: aesmaeili@sci.ui.ac.ir; Ghaedi, Kamran

    2016-03-15

    Spermatozoa could introduce exogenous oligonucleotides of interest to the oocyte. The most important reason of low efficiency of sperm mediated gene transfer (SMGT) is low uptake of exogenous DNA by spermatozoa. The aim of this study was to evaluate the effects of static magnetic field on exogenous oligonucleotide uptake of spermatozoa using magnetofection method. Magnetic nanoparticles (MNPs) associated with the labeled oligonucleotides were used to increase the efficiency of exogenous oligonucleotide uptake by rooster spermatozoa. We used high-field/high-gradient magnet (NdFeB) to enhance and accelerate exogenous DNA sedimentation at the spermatozoa surface. Flow cytometry analysis was performed to measure viability and percentage of exogenous oligonucleotide uptake by sperm. Flow cytometry analysis showed a significant increase in exogenous oligonucleotide uptake by rooster spermatozoa (P<0.001) when spermatozoa were incubated in exogenous oligonucleotide solution and MNPs. However, by applying static magnetic field during magnetofection method, a significant decrease in exogenous oligonucleotide uptake was observed (P<0.05). Findings of this study showed that MNPs were effective to increase exogenous oligonucleotide uptake by rooster spermatozoa; however unlike others studies, static magnetic field, was not only ineffective to enhance exogenous oligonucleotide uptake by rooster spermatozoa but also led to reduction in efficiency of magnetic nanoparticles in gene transfer. - Highlights: • Core/shell type Iron oxide nanoparticles were used as a novel and efficient method. • This method increases exogenous DNA uptake by rooster spermatozoa. • Static magnetic field decreased DNA uptake by rooster spermatozoa.

  16. On the vertigo due to static magnetic fields.

    Science.gov (United States)

    Mian, Omar S; Li, Yan; Antunes, Andre; Glover, Paul M; Day, Brian L

    2013-01-01

    Vertigo is sometimes experienced in and around MRI scanners. Mechanisms involving stimulation of the vestibular system by movement in magnetic fields or magnetic field spatial gradients have been proposed. However, it was recently shown that vestibular-dependent ocular nystagmus is evoked when stationary in homogenous static magnetic fields. The proposed mechanism involves Lorentz forces acting on endolymph to deflect semicircular canal (SCC) cupulae. To investigate whether vertigo arises from a similar mechanism we recorded qualitative and quantitative aspects of vertigo and 2D eye movements from supine healthy adults (n = 25) deprived of vision while pushed into the 7T static field of an MRI scanner. Exposures were variable and included up to 135s stationary at 7T. Nystagmus was mainly horizontal, persisted during long-exposures with partial decline, and reversed upon withdrawal. The dominant vertiginous perception with the head facing up was rotation in the horizontal plane (85% incidence) with a consistent direction across participants. With the head turned 90 degrees in yaw the perception did not transform into equivalent vertical plane rotation, indicating a context-dependency of the perception. During long exposures, illusory rotation lasted on average 50 s, including 42 s whilst stationary at 7T. Upon withdrawal, perception re-emerged and reversed, lasting on average 30 s. Onset fields for nystagmus and perception were significantly correlated (p<.05). Although perception did not persist as long as nystagmus, this is a known feature of continuous SSC stimulation. These observations, and others in the paper, are compatible with magnetic-field evoked-vertigo and nystagmus sharing a common mechanism. With this interpretation, response decay and reversal upon withdrawal from the field, are due to adaptation to continuous vestibular input. Although the study does not entirely exclude the possibility of mechanisms involving transient vestibular stimulation

  17. On the vertigo due to static magnetic fields.

    Directory of Open Access Journals (Sweden)

    Omar S Mian

    Full Text Available Vertigo is sometimes experienced in and around MRI scanners. Mechanisms involving stimulation of the vestibular system by movement in magnetic fields or magnetic field spatial gradients have been proposed. However, it was recently shown that vestibular-dependent ocular nystagmus is evoked when stationary in homogenous static magnetic fields. The proposed mechanism involves Lorentz forces acting on endolymph to deflect semicircular canal (SCC cupulae. To investigate whether vertigo arises from a similar mechanism we recorded qualitative and quantitative aspects of vertigo and 2D eye movements from supine healthy adults (n = 25 deprived of vision while pushed into the 7T static field of an MRI scanner. Exposures were variable and included up to 135s stationary at 7T. Nystagmus was mainly horizontal, persisted during long-exposures with partial decline, and reversed upon withdrawal. The dominant vertiginous perception with the head facing up was rotation in the horizontal plane (85% incidence with a consistent direction across participants. With the head turned 90 degrees in yaw the perception did not transform into equivalent vertical plane rotation, indicating a context-dependency of the perception. During long exposures, illusory rotation lasted on average 50 s, including 42 s whilst stationary at 7T. Upon withdrawal, perception re-emerged and reversed, lasting on average 30 s. Onset fields for nystagmus and perception were significantly correlated (p<.05. Although perception did not persist as long as nystagmus, this is a known feature of continuous SSC stimulation. These observations, and others in the paper, are compatible with magnetic-field evoked-vertigo and nystagmus sharing a common mechanism. With this interpretation, response decay and reversal upon withdrawal from the field, are due to adaptation to continuous vestibular input. Although the study does not entirely exclude the possibility of mechanisms involving transient

  18. Static Magnetic Field Therapy: A Critical Review of Treatment Parameters

    Directory of Open Access Journals (Sweden)

    Agatha P. Colbert

    2009-01-01

    Full Text Available Static magnetic field (SMF therapy, applied via a permanent magnet attached to the skin, is used by people worldwide for self-care. Despite a lack of established SMF dosage and treatment regimens, multiple studies are conducted to evaluate SMF therapy effectiveness. Our objectives in conducting this review are to: (i summarize SMF research conducted in humans; (ii critically evaluate reporting quality of SMF dosages and treatment parameters and (iii propose a set of criteria for reporting SMF treatment parameters in future clinical trials. We searched 27 electronic databases and reference lists. Only English language human studies were included. Excluded were studies of electromagnetic fields, transcranial magnetic stimulation, magnets placed on acupuncture points, animal studies, abstracts, posters and editorials. Data were extracted on clinical indication, study design and 10 essential SMF parameters. Three reviewers assessed quality of reporting and calculated a quality assessment score for each of the 10 treatment parameters. Fifty-six studies were reviewed, 42 conducted in patient populations and 14 in healthy volunteers. The SMF treatment parameters most often and most completely described were site of application, magnet support device and frequency and duration of application. Least often and least completely described were characteristics of the SMF: magnet dimensions, measured field strength and estimated distance of the magnet from the target tissue. Thirty-four (61% of studies failed to provide enough detail about SMF dosage to permit protocol replication by other investigators. Our findings highlight the need to optimize SMF dosing parameters for individual clinical conditions before proceeding to a full-scale clinical trial.

  19. Static magnetic field reduced exogenous oligonucleotide uptake by spermatozoa using magnetic nanoparticle gene delivery system

    Science.gov (United States)

    Katebi, Samira; Esmaeili, Abolghasem; Ghaedi, Kamran

    2016-03-01

    Spermatozoa could introduce exogenous oligonucleotides of interest to the oocyte. The most important reason of low efficiency of sperm mediated gene transfer (SMGT) is low uptake of exogenous DNA by spermatozoa. The aim of this study was to evaluate the effects of static magnetic field on exogenous oligonucleotide uptake of spermatozoa using magnetofection method. Magnetic nanoparticles (MNPs) associated with the labeled oligonucleotides were used to increase the efficiency of exogenous oligonucleotide uptake by rooster spermatozoa. We used high-field/high-gradient magnet (NdFeB) to enhance and accelerate exogenous DNA sedimentation at the spermatozoa surface. Flow cytometry analysis was performed to measure viability and percentage of exogenous oligonucleotide uptake by sperm. Flow cytometry analysis showed a significant increase in exogenous oligonucleotide uptake by rooster spermatozoa (Prooster spermatozoa; however unlike others studies, static magnetic field, was not only ineffective to enhance exogenous oligonucleotide uptake by rooster spermatozoa but also led to reduction in efficiency of magnetic nanoparticles in gene transfer.

  20. Static Magnetic Properties of AL800 Garnet Material

    Energy Technology Data Exchange (ETDEWEB)

    Kuharik, J. [Fermilab; Madrak, R. [Fermilab; Makarov, A. [Fermilab; Pellico, W. [Fermilab; Sun, S. [Fermilab; Tan, C. Y. [Fermilab; Terechkine, I. [Fermilab

    2017-05-17

    A second harmonic tunable RF cavity is being devel-oped for the Fermilab Booster. This device, which prom-ises reduction of the particle beam loss at the injection, transition, and extraction stages, employs perpendicularly biased garnet material for frequency tuning. The required range of the tuning is significantly wider than in previously built and tested tunable RF devices. As a result, the mag-netic field in the garnet comes fairly close to the gyromag-netic resonance line at the lower end of the frequency range. The chosen design concept of a tuner for the cavity cannot ensure uniform magnetic field in the garnet mate-rial; thus, it is important to know the static magnetic prop-erties of the material to avoid significant increase in the lo-cal RF loss power density. This report summarizes studies performed at Fermilab to understand variations in the mag-netic properties of the AL800 garnet material used to build the tuner of the cavity.

  1. Ion beam enhancement in magnetically insulated ion diodes for high-intensity pulsed ion beam generation in non-relativistic mode

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, X. P. [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024 (China); Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Zhang, Z. C.; Lei, M. K., E-mail: surfeng@dlut.edu.cn [Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Pushkarev, A. I. [Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Laboratory of Beam and Plasma Technology, High Technologies Physics Institute, Tomsk Polytechnic University, 30, Lenin Ave, 634050 Tomsk (Russian Federation)

    2016-01-15

    High-intensity pulsed ion beam (HIPIB) with ion current density above Child-Langmuir limit is achieved by extracting ion beam from anode plasma of ion diodes with suppressing electron flow under magnetic field insulation. It was theoretically estimated that with increasing the magnetic field, a maximal value of ion current density may reach nearly 3 times that of Child-Langmuir limit in a non-relativistic mode and close to 6 times in a highly relativistic mode. In this study, the behavior of ion beam enhancement by magnetic insulation is systematically investigated in three types of magnetically insulated ion diodes (MIDs) with passive anode, taking into account the anode plasma generation process on the anode surface. A maximal enhancement factor higher than 6 over the Child-Langmuir limit can be obtained in the non-relativistic mode with accelerating voltage of 200–300 kV. The MIDs differ in two anode plasma formation mechanisms, i.e., surface flashover of a dielectric coating on the anode and explosive emission of electrons from the anode, as well as in two insulation modes of external-magnetic field and self-magnetic field with either non-closed or closed drift of electrons in the anode-cathode (A-K) gap, respectively. Combined with ion current density measurement, energy density characterization is employed to resolve the spatial distribution of energy density before focusing for exploring the ion beam generation process. Consistent results are obtained on three types of MIDs concerning control of neutralizing electron flows for the space charge of ions where the high ion beam enhancement is determined by effective electron neutralization in the A-K gap, while the HIPIB composition of different ion species downstream from the diode may be considerably affected by the ion beam neutralization during propagation.

  2. 3D Biomimetic Magnetic Structures for Static Magnetic Field Stimulation of Osteogenesis

    Directory of Open Access Journals (Sweden)

    Irina Alexandra Paun

    2018-02-01

    Full Text Available We designed, fabricated and optimized 3D biomimetic magnetic structures that stimulate the osteogenesis in static magnetic fields. The structures were fabricated by direct laser writing via two-photon polymerization of IP-L780 photopolymer and were based on ellipsoidal, hexagonal units organized in a multilayered architecture. The magnetic activity of the structures was assured by coating with a thin layer of collagen-chitosan-hydroxyapatite-magnetic nanoparticles composite. In vitro experiments using MG-63 osteoblast-like cells for 3D structures with gradients of pore size helped us to find an optimum pore size between 20–40 µm. Starting from optimized 3D structures, we evaluated both qualitatively and quantitatively the effects of static magnetic fields of up to 250 mT on cell proliferation and differentiation, by ALP (alkaline phosphatase production, Alizarin Red and osteocalcin secretion measurements. We demonstrated that the synergic effect of 3D structure optimization and static magnetic stimulation enhances the bone regeneration by a factor greater than 2 as compared with the same structure in the absence of a magnetic field.

  3. 3D Biomimetic Magnetic Structures for Static Magnetic Field Stimulation of Osteogenesis.

    Science.gov (United States)

    Paun, Irina Alexandra; Popescu, Roxana Cristina; Calin, Bogdan Stefanita; Mustaciosu, Cosmin Catalin; Dinescu, Maria; Luculescu, Catalin Romeo

    2018-02-07

    We designed, fabricated and optimized 3D biomimetic magnetic structures that stimulate the osteogenesis in static magnetic fields. The structures were fabricated by direct laser writing via two-photon polymerization of IP-L780 photopolymer and were based on ellipsoidal, hexagonal units organized in a multilayered architecture. The magnetic activity of the structures was assured by coating with a thin layer of collagen-chitosan-hydroxyapatite-magnetic nanoparticles composite. In vitro experiments using MG-63 osteoblast-like cells for 3D structures with gradients of pore size helped us to find an optimum pore size between 20-40 µm. Starting from optimized 3D structures, we evaluated both qualitatively and quantitatively the effects of static magnetic fields of up to 250 mT on cell proliferation and differentiation, by ALP (alkaline phosphatase) production, Alizarin Red and osteocalcin secretion measurements. We demonstrated that the synergic effect of 3D structure optimization and static magnetic stimulation enhances the bone regeneration by a factor greater than 2 as compared with the same structure in the absence of a magnetic field.

  4. High intensity hadron accelerators

    International Nuclear Information System (INIS)

    Teng, L.C.

    1989-05-01

    This rapporteur report consists mainly of two parts. Part I is an abridged review of the status of all High Intensity Hadron Accelerator projects in the world in semi-tabulated form for quick reference and comparison. Part II is a brief discussion of the salient features of the different technologies involved. The discussion is based mainly on my personal experiences and opinions, tempered, I hope, by the discussions I participated in in the various parallel sessions of the workshop. In addition, appended at the end is my evaluation and expression of the merits of high intensity hadron accelerators as research facilities for nuclear and particle physics

  5. Feasibility of magnetic resonance imaging-guided high intensity focused ultrasound therapy for ablating uterine fibroids in patients with bowel lies anterior to uterus

    International Nuclear Information System (INIS)

    Zhang Lian; Chen Wenzhi; Liu Yinjiang; Hu Xiao; Zhou Kun; Chen Li; Peng Song; Zhu Hui; Zou Huiling; Bai Jin; Wang Zhibiao

    2010-01-01

    Purpose: To prospectively evaluate the feasibility of magnetic resonance (MR) imaging-guided high intensity focused ultrasound (HIFU) therapeutic ablation of uterine fibroids in patients with bowel lies anterior to uterus. Materials and methods: Twenty-one patients with 23 uterine fibroids underwent MR imaging-guided high intensity focused ultrasound treatment, with a mean age of 39.4 ± 6.9 (20-49) years, with fibroids average measuring 6.0 ± 1.6 (range, 2.9-9.5) cm in diameter. After being compressed with a degassed water balloon on abdominal wall, MR imaging-guided high intensity focused ultrasound treatment was performed under conscious sedation by using fentanyl and midazolam. This procedure was performed by a Haifu JM focused ultrasound tumour therapeutic system (JM2.5C, Chongqing Haifu Technology Co., Ltd., China), in combination with a 1.5-Tesla MRI system (Symphony, Siemens, Germany), which provides real-time guidance and control. Contrast-enhanced MR imaging was performed to evaluate the efficacy of thermal ablation immediately and 3 months after HIFU treatment. The treatment time and adverse events were recorded. Results: The mean fibroid volume was 97.0 ± 78.3 (range, 12.7-318.3) cm 3 . According to the treatment plan, an average 75.0 ± 11.4% (range, 37.8-92.4%) of the fibroid volume was treated. The mean fibroid volume immediately after HIFU was 109.7 ± 93.1 (range, 11.9-389.6) cm 3 , slightly enlarged because of edema. The average non-perfused volume was 83.3 ± 71.7 (range, 7.7-282.9) cm 3 , the average fractional ablation, which was defined as non-perfused volume divided by the fibroid volume immediately after HIFU treatment, was 76.9 ± 18.7% (range, 21.0-97.0%). There were no statistically significant differences between the treatment volume and the non-perfused volume. Follow-up magnetic resonance imaging (MRI) at 3 months obtained in 12 patients, the fibroid volume decreased by 31.4 ± 29.3% (range, -1.9 to 60.0%) in average, with paired t

  6. Feasibility of magnetic resonance imaging-guided high intensity focused ultrasound therapy for ablating uterine fibroids in patients with bowel lies anterior to uterus

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lian; Chen Wenzhi [Clinical Center for Tumour Therapy of 2nd Affiliated Hospital of Chongqing University of Medical Sciences, Chongqing 400010 (China); Liu Yinjiang; Hu Xiao [National Engineering Research Center of Ultrasound Medicine, Chongqing 400010 (China); Zhou Kun [Clinical Center for Tumour Therapy of 2nd Affiliated Hospital of Chongqing University of Medical Sciences, Chongqing 400010 (China); Chen Li [National Engineering Research Center of Ultrasound Medicine, Chongqing 400010 (China); Peng Song; Zhu Hui [Clinical Center for Tumour Therapy of 2nd Affiliated Hospital of Chongqing University of Medical Sciences, Chongqing 400010 (China); Zou Huiling [National Engineering Research Center of Ultrasound Medicine, Chongqing 400010 (China); Bai Jin [Institute of Ultrasound Engineering in Medicine of Chongqing University of Medical Sciences, Chongqing 400016 (China); Wang Zhibiao [Clinical Center for Tumour Therapy of 2nd Affiliated Hospital of Chongqing University of Medical Sciences, Chongqing 400010 (China); National Engineering Research Center of Ultrasound Medicine, Chongqing 400010 (China); Institute of Ultrasound Engineering in Medicine of Chongqing University of Medical Sciences, Chongqing 400016 (China)], E-mail: wangzhibiao@haifu.com.cn

    2010-02-15

    Purpose: To prospectively evaluate the feasibility of magnetic resonance (MR) imaging-guided high intensity focused ultrasound (HIFU) therapeutic ablation of uterine fibroids in patients with bowel lies anterior to uterus. Materials and methods: Twenty-one patients with 23 uterine fibroids underwent MR imaging-guided high intensity focused ultrasound treatment, with a mean age of 39.4 {+-} 6.9 (20-49) years, with fibroids average measuring 6.0 {+-} 1.6 (range, 2.9-9.5) cm in diameter. After being compressed with a degassed water balloon on abdominal wall, MR imaging-guided high intensity focused ultrasound treatment was performed under conscious sedation by using fentanyl and midazolam. This procedure was performed by a Haifu JM focused ultrasound tumour therapeutic system (JM2.5C, Chongqing Haifu Technology Co., Ltd., China), in combination with a 1.5-Tesla MRI system (Symphony, Siemens, Germany), which provides real-time guidance and control. Contrast-enhanced MR imaging was performed to evaluate the efficacy of thermal ablation immediately and 3 months after HIFU treatment. The treatment time and adverse events were recorded. Results: The mean fibroid volume was 97.0 {+-} 78.3 (range, 12.7-318.3) cm{sup 3}. According to the treatment plan, an average 75.0 {+-} 11.4% (range, 37.8-92.4%) of the fibroid volume was treated. The mean fibroid volume immediately after HIFU was 109.7 {+-} 93.1 (range, 11.9-389.6) cm{sup 3}, slightly enlarged because of edema. The average non-perfused volume was 83.3 {+-} 71.7 (range, 7.7-282.9) cm{sup 3}, the average fractional ablation, which was defined as non-perfused volume divided by the fibroid volume immediately after HIFU treatment, was 76.9 {+-} 18.7% (range, 21.0-97.0%). There were no statistically significant differences between the treatment volume and the non-perfused volume. Follow-up magnetic resonance imaging (MRI) at 3 months obtained in 12 patients, the fibroid volume decreased by 31.4 {+-} 29.3% (range, -1.9 to 60

  7. Retrospective assessment of exposure to static magnetic fields during production and development of magnetic resonance imaging systems

    NARCIS (Netherlands)

    Bongers, Suzan|info:eu-repo/dai/nl/313874050; Christopher, Yvette|info:eu-repo/dai/nl/27590184X; Engels, Hans; Slottje, Pauline|info:eu-repo/dai/nl/299345351; Kromhout, Hans|info:eu-repo/dai/nl/074385224

    2014-01-01

    At present, the relationship between chronic exposure to static magnetic fields (SMF) and health effects is unclear. We developed a task-based deterministic model for estimating historical electromagnetic field exposure from the static B-field (B0) of magnetic resonance imaging (MRI) systems, for a

  8. Can pre- and postoperative magnetic resonance imaging predict recurrence-free survival after whole-gland high-intensity focused ablation for prostate cancer?

    Energy Technology Data Exchange (ETDEWEB)

    Rosset, Remy; Bratan, Flavie [Hopital Edouard Herriot, Hospices Civils de Lyon, Department of Urinary and Vascular Radiology, Lyon (France); Crouzet, Sebastien [Hopital Edouard Herriot, Hospices Civils de Lyon, Department of Urology, Lyon (France); Universite de Lyon, Lyon (France); Faculte de Medecine Lyon Est, Universite Lyon 1, Lyon (France); Inserm, U1032, LabTau, Lyon (France); Tonoli-Catez, Helene [Hopital Edouard Herriot, Hospices Civils de Lyon, Department of Urology, Lyon (France); Mege-Lechevallier, Florence [Hopital Edouard Herriot, Hospices Civils de Lyon, Department of Pathology, Lyon (France); Gelet, Albert [Hopital Edouard Herriot, Hospices Civils de Lyon, Department of Urology, Lyon (France); Inserm, U1032, LabTau, Lyon (France); Rouviere, Olivier [Hopital Edouard Herriot, Hospices Civils de Lyon, Department of Urinary and Vascular Radiology, Lyon (France); Universite de Lyon, Lyon (France); Faculte de Medecine Lyon Est, Universite Lyon 1, Lyon (France); Inserm, U1032, LabTau, Lyon (France)

    2017-04-15

    Our aim was to assess whether magnetic resonance imaging (MRI) features predict recurrence-free survival (RFS) after prostate cancer high-intensity focused ultrasound (HIFU) ablation. We retrospectively selected 81 patients who underwent (i) whole-gland HIFU ablation between 2007 and 2011 as first-line therapy or salvage treatment after radiotherapy or brachytherapy, and (ii) pre- and postoperative MRI. On preoperative imaging, two senior (R1, R2) and one junior (R3) readers assessed the number of sectors invaded by the lesion with the highest Likert score (dominant lesion) using a 27-sector diagram. On postoperative imaging, readers assessed destruction of the dominant lesion using a three-level score. Multivariate analysis included the number of sectors invaded by the dominant lesion, its Likert and destruction scores, the pre-HIFU prostate-specific antigen (PSA) level, Gleason score, and the clinical setting (primary/salvage). The most significant predictor was the number of prostate sectors invaded by the dominant lesion for R2 and R3 (p≤0.001) and the destruction score of the dominant lesion for R1 (p = 0.011). The pre-HIFU PSA level was an independent predictor for R2 (p = 0.014), but with only marginal significance for R1 (p = 0.059) and R3 (p = 0.053). The dominant lesion's size and destruction assessed by MRI provide independent prognostic information compared with usual predictors. (orig.)

  9. Immunomodulatory effects of L-carnitine and q10 in mouse spleen exposed to low-frequency high-intensity magnetic field

    International Nuclear Information System (INIS)

    Arafa, Hossam M.M.; Abd-Allah, Adel R.A.; El-Mahdy, Mohamad A.; Ramadan, Laila A.; Hamada, Farid M.A.

    2003-01-01

    In the current study, we have investigated the bioeffects of repeated exposure to low-frequency (50 Hz) high-intensity (20 mT; 200 G) electromagnetic field (EMF) on some immune parameters in mice. The animals were exposed to EMF daily for 30 min three times per week for 2 weeks. We also studied the possible immunomodulatory effects of two anti-radical substances known to have non-specific immunostimulant effects namely, L-carnitine (200 mg/kg body weight i.p.) and Q10 (200 mg/kg body weight, p.o.). Both drugs were given 1 h prior to each EMF exposure. Immune endpoints included total body weight, spleen/body weight ratio, splenocytes viability, total and differential white blood cell (WBCs; lymphocytes, monocytes, neutrophils) counts, as well as the lymphocyte proliferation induced by the mitogens; phytohaemagglutinin (PHA), concanavalin-A (Con-A) and lipoploysaccharide (LPS). Magnetic field decreased splenocyte viability, WBCs count, as well as mitogens-induced lymphocyte proliferation. L-carnitine, but not Q10 could ameliorate the adverse effects of EMF on the vast majority of the immune parameters tested, suggesting a possible immunoprotective role of L-carnitine under the current experimental conditions

  10. Association between duration of coronary occlusion and high-intensity signal on T1-weighted magnetic resonance imaging among patients with angiographic total occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Kenji; Ehara, Shoichi; Hasegawa, Takao; Sakaguchi, Mikumo; Shimada, Kenei [Osaka City University Graduate School of Medicine, Department of Cardiovascular Medicine, Abeno-ku, Osaka (Japan)

    2017-09-15

    To evaluate the association between duration of the coronary occlusion and high-intensity signal (HIS) on noncontrast T1-weighted imaging using a 1.5-T magnetic resonance imager among patients with angiographic coronary total occlusion. The signal intensity of the coronary target area divided by the signal intensity of the left ventricular muscle near the target area at each site (TMR) was measured. Areas with a TMR >1.0 were defined as HIS. Thirty five lesions from 33 patients were divided into the following three groups: subacute occlusion (up to 3 months; n = 7), short-duration chronic total occlusion (SD-CTO: 3-6 months; n = 9) and long-duration CTO (LD-CTO: ≥6 months; n = 19). All subacute occlusion lesions showed a HIS within the occlusion site. Among patients with CTO, the frequency of a HIS within the occlusion site was significantly higher in SD-CTO than in LD-CTO lesions (p = 0.013). In multivariate analyses, only an occlusion duration of less than 6 months was an independent factor associated with the presence of HIS (odds ratio 7.6, 95% CI 1.1-54.5; p = 0.044). The presence of a HIS in the occlusion site was associated more with SD-CTO than with LD-CTO among patients with CTO. (orig.)

  11. Association between duration of coronary occlusion and high-intensity signal on T1-weighted magnetic resonance imaging among patients with angiographic total occlusion

    International Nuclear Information System (INIS)

    Matsumoto, Kenji; Ehara, Shoichi; Hasegawa, Takao; Sakaguchi, Mikumo; Shimada, Kenei

    2017-01-01

    To evaluate the association between duration of the coronary occlusion and high-intensity signal (HIS) on noncontrast T1-weighted imaging using a 1.5-T magnetic resonance imager among patients with angiographic coronary total occlusion. The signal intensity of the coronary target area divided by the signal intensity of the left ventricular muscle near the target area at each site (TMR) was measured. Areas with a TMR >1.0 were defined as HIS. Thirty five lesions from 33 patients were divided into the following three groups: subacute occlusion (up to 3 months; n = 7), short-duration chronic total occlusion (SD-CTO: 3-6 months; n = 9) and long-duration CTO (LD-CTO: ≥6 months; n = 19). All subacute occlusion lesions showed a HIS within the occlusion site. Among patients with CTO, the frequency of a HIS within the occlusion site was significantly higher in SD-CTO than in LD-CTO lesions (p = 0.013). In multivariate analyses, only an occlusion duration of less than 6 months was an independent factor associated with the presence of HIS (odds ratio 7.6, 95% CI 1.1-54.5; p = 0.044). The presence of a HIS in the occlusion site was associated more with SD-CTO than with LD-CTO among patients with CTO. (orig.)

  12. Coupled electron/photon transport in static external magnetic fields

    International Nuclear Information System (INIS)

    Halbleib, J.A. Sr.; Vandevender, W.H.

    A model is presented which describes coupled electron/photon transport in the presence of static magnetic fields of arbitrary spatial dependence. The method combines state-of-the-art condensed-history electron collisional Monte Carlo and single-scattering photon Monte Carlo, including electron energy-loss straggling and the production and transport of all generations of secondaries, with numerical field integration via the best available variable-step-size Runge-Kutta-Fehlberg or variable-order/variable-step-size Adams PECE differential equation solvers. A three-dimensional cartesian system is employed in the description of particle trajectories. Although the present model is limited to multilayer material configurations, extension to more complex material geometries should not be difficult. Among the more important options are (1) a feature which permits the neglect of field effects in regions where transport is collision dominated and (2) a method for describing the transport in variable-density media where electron energies and material densities are sufficiently low that the density effect on electronic stopping powers may be neglected. (U.S.)

  13. Magnetic memory signals variation induced by applied magnetic field and static tensile stress in ferromagnetic steel

    International Nuclear Information System (INIS)

    Huang, Haihong; Yang, Cheng; Qian, Zhengchun; Han, Gang; Liu, Zhifeng

    2016-01-01

    Stress can induce a spontaneous magnetic field in ferromagnetic steel under the excitation of geomagnetic field. In order to investigate the impact of applied magnetic field and tensile stress on variation of the residual magnetic signals on the surface of ferromagnetic materials, static tensile tests of Q235 structural steel were carried out, with the normal component of the residual magnetic signals, H p (y), induced by applied magnetic fields with different intensities measured through the tensile tests. The H p (y), its slope coefficient K S and maximum gradient K max changing with the applied magnetic field H and tensile stress were observed. Results show that the magnitude of H p (y) and its slope coefficient K S increase linearly with the increase of stress in the elastic deformation stage. Under yield stress, H p (y) and K S reach its maximum, and then decrease slightly with further increase of stress. Applied magnetic field affects the magnitude of H p (y) instead of changing the signal curve′s profile; and the magnitude of H p (y), K S , K max and the change rate of K S increase with the increase of applied magnetic field. The phenomenon is also discussed from the viewpoint of magnetic charge in ferromagnetic materials. - Highlights: • We investigated how applied magnetic field and tensile stress impact H p (y) signals. • Magnitude of H p (y), K S and K max increase with the increase of applied magnetic field. • Both applied magnetic field and tensile stress impact material magnetic permeability. • Applied magnetic field can help to evaluate the stress distribution of components.

  14. Magnetic memory signals variation induced by applied magnetic field and static tensile stress in ferromagnetic steel

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Haihong, E-mail: huanghaihong@hfut.edu.cn; Yang, Cheng; Qian, Zhengchun; Han, Gang; Liu, Zhifeng

    2016-10-15

    Stress can induce a spontaneous magnetic field in ferromagnetic steel under the excitation of geomagnetic field. In order to investigate the impact of applied magnetic field and tensile stress on variation of the residual magnetic signals on the surface of ferromagnetic materials, static tensile tests of Q235 structural steel were carried out, with the normal component of the residual magnetic signals, H{sub p}(y), induced by applied magnetic fields with different intensities measured through the tensile tests. The H{sub p}(y), its slope coefficient K{sub S} and maximum gradient K{sub max} changing with the applied magnetic field H and tensile stress were observed. Results show that the magnitude of H{sub p}(y) and its slope coefficient K{sub S} increase linearly with the increase of stress in the elastic deformation stage. Under yield stress, H{sub p}(y) and K{sub S} reach its maximum, and then decrease slightly with further increase of stress. Applied magnetic field affects the magnitude of H{sub p}(y) instead of changing the signal curve′s profile; and the magnitude of H{sub p}(y), K{sub S}, K{sub max} and the change rate of K{sub S} increase with the increase of applied magnetic field. The phenomenon is also discussed from the viewpoint of magnetic charge in ferromagnetic materials. - Highlights: • We investigated how applied magnetic field and tensile stress impact H{sub p}(y) signals. • Magnitude of H{sub p}(y), K{sub S} and K{sub max} increase with the increase of applied magnetic field. • Both applied magnetic field and tensile stress impact material magnetic permeability. • Applied magnetic field can help to evaluate the stress distribution of components.

  15. Effects of Static Magnetic Fields on the Physical, Mechanical, and Microstructural Properties of Cement Pastes

    OpenAIRE

    Soto-Bernal, Juan J.; Gonzalez-Mota, Rosario; Rosales-Candelas, Iliana; Ortiz-Lozano, Jose A.

    2015-01-01

    This paper presents the results of an experimental study carried out to comprehend the physical, mechanical, and microstructural behavior of cement pastes subjected to static magnetic fields while hydrating and setting. The experimental methodology consisted in exposing fresh cement pastes to static magnetic fields at three different magnetic induction strengths: 19.07, 22.22, and 25.37 Gauss. The microstructural characterization makes evident that there are differences in relation to amount ...

  16. A Steel Wire Stress Measuring Sensor Based on the Static Magnetization by Permanent Magnets

    Directory of Open Access Journals (Sweden)

    Dongge Deng

    2016-10-01

    Full Text Available A new stress measuring sensor is proposed to evaluate the axial stress in steel wires. Without using excitation and induction coils, the sensor mainly consists of a static magnetization unit made of permanent magnets and a magnetic field measurement unit containing Hall element arrays. Firstly, the principle is illustrated in detail. Under the excitation of the magnetization unit, a spatially varying magnetized region in the steel wire is utilized as the measurement region. Radial and axial magnetic flux densities at different lift-offs in this region are measured by the measurement unit to calculate the differential permeability curve and magnetization curve. Feature parameters extracted from the curves are used to evaluate the axial stress. Secondly, the special stress sensor for Φ5 and Φ7 steel wires is developed accordingly. At last, the performance of the sensor is tested experimentally. Experimental results show that the sensor can measure the magnetization curve accurately with the error in the range of ±6%. Furthermore, the obtained differential permeability at working points 1200 A/m and 10000 A/m change almost linearly with the stress in steel wires, the goodness of linear fits are all higher than 0.987. Thus, the proposed steel wire stress measuring sensor is feasible.

  17. High intensity focused ultrasound treatment of adenomyosis: The relationship between the features of magnetic resonance imaging on T2 weighted images and the therapeutic efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Chunmei [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Ultrasound in Medicine and Engineering, Chongqing Haifu Hospital, College of Biomedical Engineering, Chongqing Medical University, Chongqing (China); Setzen, Raymond [Department of Obstetrics and Gynecology, Chris Hani Baragwanath Academic Hospital, Johannesburg (South Africa); Liu, Zhongqiong; Liu, Yunchang [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Ultrasound in Medicine and Engineering, Chongqing Haifu Hospital, College of Biomedical Engineering, Chongqing Medical University, Chongqing (China); Xie, Bin [Department of Ultrasound, Huanggang Central Hospital, Huanggang City, Hubei 438000 (China); Aili, Aixingzi, E-mail: 1819483078@qq.com [Shanghai First Maternity and Infant Health Hospital, Shanghai (China); Zhang, Lian, E-mail: lianwzhang@yahoo.com [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Ultrasound in Medicine and Engineering, Chongqing Haifu Hospital, College of Biomedical Engineering, Chongqing Medical University, Chongqing (China)

    2017-04-15

    Objectives: To investigate the relationship between the features of magnetic resonance imaging (MRI) on T2 weighted images (T2WI) and the therapeutic efficacy of high intensity focused ultrasound (HIFU) on adenomyosis. Materials and methods: From January 2011 to November 2015, four hundred and twenty-eight patients with symptomatic adenomyosis were treated with HIFU. Based on the signal intensity and the number of hyperintense foci in the adenomyotic lesions on T2WI, the patients were classified into groups. The day after HIFU ablation patients underwent contrast-enhanced MRI and a comparison was made of non-perfused volume (NPV) ratio, energy efficiency factor (EEF), treatment time, sonication time, and adverse effects. Results: No significant difference in terms of HIFU treatment settings and results was observed between the group of patients with hypointense adenomyotic lesions and the group with isointense adenomyotic lesions (P > 0.05). However, the sonication time and EEF were significantly higher in the group with multiple hyperintense foci compared to the group with few hyperintense foci. The NPV ratio achieved in the lesions with multiple hyperintenese foci was significantly lower than that in the lesions with few hyperintense foci (P < 0.05). No significant difference was observed in the rate of adverse effects between the two groups. Conclusions: Based on our results, the response of the adenomyotic lesions to HIFU treatment is not related to the signal intensity of adenomyotic lesions on T2WI. However, the number of the high signal intensity foci in the adenomyotic lesions on T2WI can be considered as a predictive factor to help select patients for HIFU treatment.

  18. Preservation of the endometrial enhancement after magnetic resonance imaging-guided high-intensity focused ultrasound ablation of submucosal uterine fibroids

    International Nuclear Information System (INIS)

    Kim, Young-sun; Kim, Tae-Joong; Lee, Jeong-Won; Kim, Byoung-Gie; Lim, Hyo Keun; Rhim, Hyunchul; Jung, Sin-Ho; Ahn, Joong Hyun

    2017-01-01

    To evaluate the integrity of endometrial enhancement after magnetic resonance imaging-guided high-intensity focused ultrasound (MR-HIFU) ablation of submucosal uterine fibroids based on contrast-enhanced MRI findings, and to identify the risk factors for endometrial impairment. In total, 117 submucosal fibroids (diameter: 5.9 ± 3.0 cm) in 101 women (age: 43.6 ± 4.4 years) treated with MR-HIFU ablation were retrospectively analysed. Endometrial integrity was assessed with contrast-enhanced T1-weighted images at immediate (n = 101), 3-month (n = 62) and 12-month (n = 15) follow-ups. Endometrial impairment was classified into grades 0 (continuous endometrium), 1 (pin-point, full-thickness discontinuity), 2 (between grade 1 and 3), or 3 (full-thickness discontinuity >1 cm). Risk factors were assessed with generalized estimating equation (GEE) analysis. Among 117 fibroids, grades 0, 1, 2 and 3 endometrial impairments were observed at initial examination in 56.4%, 24.8%, 13.7% and 4.3%, respectively. Among 37 fibroid cases of endometrial impairment for which follow-ups were conducted, 30 showed improvements at 3- and/or 12-month follow-up. GEE analysis revealed the degree of endometrial protrusion was significantly associated with severity of endometrial injury (P < 0.0001). After MR-HIFU ablation of submucosal fibroids, endometrial enhancement was preserved intact or minimally impaired in most cases. Impaired endometrium, which is more common after treating endometrially-protruded fibroids, may recover spontaneously. (orig.)

  19. High intensity focused ultrasound treatment of adenomyosis: The relationship between the features of magnetic resonance imaging on T2 weighted images and the therapeutic efficacy

    International Nuclear Information System (INIS)

    Gong, Chunmei; Setzen, Raymond; Liu, Zhongqiong; Liu, Yunchang; Xie, Bin; Aili, Aixingzi; Zhang, Lian

    2017-01-01

    Objectives: To investigate the relationship between the features of magnetic resonance imaging (MRI) on T2 weighted images (T2WI) and the therapeutic efficacy of high intensity focused ultrasound (HIFU) on adenomyosis. Materials and methods: From January 2011 to November 2015, four hundred and twenty-eight patients with symptomatic adenomyosis were treated with HIFU. Based on the signal intensity and the number of hyperintense foci in the adenomyotic lesions on T2WI, the patients were classified into groups. The day after HIFU ablation patients underwent contrast-enhanced MRI and a comparison was made of non-perfused volume (NPV) ratio, energy efficiency factor (EEF), treatment time, sonication time, and adverse effects. Results: No significant difference in terms of HIFU treatment settings and results was observed between the group of patients with hypointense adenomyotic lesions and the group with isointense adenomyotic lesions (P > 0.05). However, the sonication time and EEF were significantly higher in the group with multiple hyperintense foci compared to the group with few hyperintense foci. The NPV ratio achieved in the lesions with multiple hyperintenese foci was significantly lower than that in the lesions with few hyperintense foci (P < 0.05). No significant difference was observed in the rate of adverse effects between the two groups. Conclusions: Based on our results, the response of the adenomyotic lesions to HIFU treatment is not related to the signal intensity of adenomyotic lesions on T2WI. However, the number of the high signal intensity foci in the adenomyotic lesions on T2WI can be considered as a predictive factor to help select patients for HIFU treatment.

  20. Preservation of the endometrial enhancement after magnetic resonance imaging-guided high-intensity focused ultrasound ablation of submucosal uterine fibroids

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young-sun [Samsung Medical Center, Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); Uterine Fibroid Integrated Management Center, MINT Intervention Hospital, Department of Radiology, Seoul (Korea, Republic of); Kim, Tae-Joong; Lee, Jeong-Won; Kim, Byoung-Gie [Samsung Medical Center, Sungkyunkwan University School of Medicine, Department of Obstetrics and Gynecology, Seoul (Korea, Republic of); Lim, Hyo Keun [Samsung Medical Center, Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); SAIHST, Sungkyunkwan University, Department of Health Sciences and Technology, Seoul (Korea, Republic of); Rhim, Hyunchul [Samsung Medical Center, Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); Jung, Sin-Ho [SAIHST, Sungkyunkwan University, Department of Health Sciences and Technology, Seoul (Korea, Republic of); Samsung Medical Center, Department of Biostatistics and Clinical Epidemiology, Seoul (Korea, Republic of); Ahn, Joong Hyun [Samsung Biomedical Research Institute, Samsung Medical Center, Biostatistics Team, Seoul (Korea, Republic of)

    2017-09-15

    To evaluate the integrity of endometrial enhancement after magnetic resonance imaging-guided high-intensity focused ultrasound (MR-HIFU) ablation of submucosal uterine fibroids based on contrast-enhanced MRI findings, and to identify the risk factors for endometrial impairment. In total, 117 submucosal fibroids (diameter: 5.9 ± 3.0 cm) in 101 women (age: 43.6 ± 4.4 years) treated with MR-HIFU ablation were retrospectively analysed. Endometrial integrity was assessed with contrast-enhanced T1-weighted images at immediate (n = 101), 3-month (n = 62) and 12-month (n = 15) follow-ups. Endometrial impairment was classified into grades 0 (continuous endometrium), 1 (pin-point, full-thickness discontinuity), 2 (between grade 1 and 3), or 3 (full-thickness discontinuity >1 cm). Risk factors were assessed with generalized estimating equation (GEE) analysis. Among 117 fibroids, grades 0, 1, 2 and 3 endometrial impairments were observed at initial examination in 56.4%, 24.8%, 13.7% and 4.3%, respectively. Among 37 fibroid cases of endometrial impairment for which follow-ups were conducted, 30 showed improvements at 3- and/or 12-month follow-up. GEE analysis revealed the degree of endometrial protrusion was significantly associated with severity of endometrial injury (P < 0.0001). After MR-HIFU ablation of submucosal fibroids, endometrial enhancement was preserved intact or minimally impaired in most cases. Impaired endometrium, which is more common after treating endometrially-protruded fibroids, may recover spontaneously. (orig.)

  1. Suitability of a tumour-mimicking material for the evaluation of high-intensity focused ultrasound ablation under magnetic resonance guidance

    International Nuclear Information System (INIS)

    Pichardo, S; Kivinen, J; Curiel, L; Melodelima, D

    2013-01-01

    This study tests the suitability of a tumour-mimic for targeting magnetic resonance (MR)-guided high-intensity focused ultrasound (HIFU). An agarose-based tumour-mimic was injected as a warm solution that polymerized in tissue. Thermal characteristics and acoustic absorption of the mimic were observed within the values reported for tissues. The relaxation times at 3T were 1679 ± 15 ms for T1 and 41 ± 1 ms for T2. The mimic was clearly visible on in vivo images. With lower contrast the tumour-mimic was visible on T2-weighted images, where it was possible to detect the ablated tissue surrounding the mimic after sonications. HIFU sonications were performed to induce thermal ablation on and around the mimic using a Sonalleve system (Philips). MR thermometry maps were performed during HIFU. The average temperature when the sonication was done at the tumour-mimic was 67.6 ± 8.0 °C in vitro and 67.6 ± 5.0 °C in vivo. The average temperature for sonications at tissues was 68.4 ± 8.7 °C in vitro (liver) and 66.0 ± 2.6 °C in vivo (muscle), with no significant difference between tissue and tumour-mimic (p > 0.05). The tumour-mimic behaviour when using MR-guided HIFU was similar to tissues, showing that this mimic can be used as an alternative to tumour models for validating MR-guided HIFU devices targeting. (paper)

  2. Neutron depolarization study of static and dynamic magnetic properties of ferromagnets

    International Nuclear Information System (INIS)

    Stuesser, N.

    1986-01-01

    In this thesis neutron depolarization experiments are performed on amorphous and crystalline ferromagnetic materials. The subjects studied are concerned with 'domain structure in magnetically weak uniaxial amorphous ferromagnetic ribbons', 'static critical behaviour at the ferromagnetic-paramagnetic phase transition', 'small magnetic anisotropy in nickel near T c ', and 'magnetization reversal in conducting ferromagnets'. 87 refs.; 37 figs.; 3 tabs

  3. TWO DIMENTIONAL STATIC MAGNETIC ANALYSIS OF RADIAL MAGNETIC BEARING SYSTEMS WITH DIFFERENT STRUCTURES

    Directory of Open Access Journals (Sweden)

    Yusuf ÖNER

    2005-03-01

    Full Text Available The friction loss of electrical machines is an important problem as like in other rotary machines. In addition, the bearings, where the friction losses occur, also require lubrication at periodic intervals and need to be maintained. In this study, to minimize the friction loss of electrical motor, two dimentional static magnetic analysis of radial magnetic bearing systems with different structures are performed and compared with each other; also, magnetic bearing system with four-pole is realized and applied to an induction motor. In simulation, the forces applied to the rotor of induction motor from designed magnetic bearing system are calculated in a computer by using FEMM software package. In application, when comparing designed magnetic bearing system with mechanical bearings up to the revolution of 350 rpm, it was observed that the loss of no-load operating condition of induction motor is decreased about 15 % with magnetic bearing system. In addition to this, mechanical noisy of the motor is also decreased considerably.

  4. Magnetic resonance imaging for the exploitation of bubble-enhanced heating by high-intensity focused ultrasound: a feasibility study in ex vivo liver.

    Science.gov (United States)

    Elbes, Delphine; Denost, Quentin; Robert, Benjamin; Köhler, Max O; Tanter, Mickaël; Bruno, Quesson

    2014-05-01

    Bubble-enhanced heating (BEH) may be exploited to improve the heating efficiency of high-intensity focused ultrasound in liver and to protect tissues located beyond the focal point. The objectives of this study, performed in ex vivo pig liver, were (i) to develop a method to determine the acoustic power threshold for induction of BEH from displacement images measured by magnetic resonance acoustic radiation force imaging (MR-ARFI), and (ii) to compare temperature distribution with MR thermometry for HIFU protocols with and without BEH. The acoustic threshold for generation of BEH was determined in ex vivo pig liver from MR-ARFI calibration curves of local tissue displacement resulting from sonication at different powers. Temperature distributions (MR thermometry) resulting from "conventional" sonications (20 W, 30 s) were compared with those from "composite" sonications performed at identical parameters, but after a HIFU burst pulse (0.5 s, acoustic power over the threshold for induction of BEH). Displacement images (MR-ARFI) were acquired between sonications to measure potential modifications of local tissue displacement associated with modifications of tissue acoustic characteristics induced by the burst HIFU pulse. The acoustic threshold for induction of BEH corresponded to a displacement amplitude of approximately 50 μm in ex vivo liver. The displacement and temperature images of the composite group exhibited a nearly spherical pattern, shifted approximately 4 mm toward the transducer, in contrast to elliptical shapes centered on the natural focal position for the conventional group. The gains in maximum temperature and displacement values were 1.5 and 2, and the full widths at half-maximum of the displacement data were 1.7 and 2.2 times larger than in the conventional group in directions perpendicular to ultrasound propagation axes. Combination of MR-ARFI and MR thermometry for calibration and exploitation of BEH appears to increase the efficiency and safety

  5. Trapped field recovery of bulk superconductor magnets by static field magnetization

    Science.gov (United States)

    Deng, Z.; Tsuzuki, K.; Miki, M.; Felder, B.; Hara, S.; Izumi, M.

    2011-11-01

    Thanks to the trapped field of bulk high-temperature superconductors, they can be used as field-pole magnets in the high temperature superconducting (HTS) rotating machines. For example, an output power of 10 kW at 720 rpm was realized by an average trapped field of 0.56 T of eight melt-textured GdBa2Cu3Oy (Gd-123) bulks at liquid nitrogen temperature in TUMSAT in 2004. Similarly to the HTS machines involving 1G or 2G wires, the trapped field of the bulk is possibly sensitive and even can be attenuated by the AC component field during the operation. Hence, it is necessary to recover the trapped field once being decreased to some extent in the practical application. From this point, we have investigated the trapped field recovery of HTS bulk magnets by static field magnetization in the paper. A series of different initial trapped fields after zero-field-cooling or field-cooling magnetization are used to simulate the attenuated trapped field. By comparing the trapped field peak and its distribution, the trapped field was found to be able to recover by the static field magnetization method with a stronger excitation field and the initial trapped flux inside the bulk also has an influence on the recovery process. The optimum recovery field was found to be about 2.5 times the saturated trapped field of the bulk at liquid nitrogen temperature, by which the bulk can regain the former best trapped field performance.

  6. Trapped field recovery of bulk superconductor magnets by static field magnetization

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Z., E-mail: zigang@kaiyodai.ac.jp [Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo 135-8533 (Japan); Tsuzuki, K.; Miki, M.; Felder, B.; Hara, S.; Izumi, M. [Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo 135-8533 (Japan)

    2011-11-15

    A series of initial trapped fields after ZFC or FC magnetization are used to simulate the attenuated trapped field. It is possible and easy to recover the lost trapped field and regain the best trapped field performance as before. In the re-magnetization process, the initial magnetic flux inside the bulk magnets will help to recover the trapped field. The optimum recovery field is recommended to be 2.5 times the saturation field of the bulk at LN2 temperature. Thanks to the trapped field of bulk high-temperature superconductors, they can be used as field-pole magnets in the high temperature superconducting (HTS) rotating machines. For example, an output power of 10 kW at 720 rpm was realized by an average trapped field of 0.56 T of eight melt-textured GdBa{sub 2}Cu{sub 3}O{sub y} (Gd-123) bulks at liquid nitrogen temperature in TUMSAT in 2004. Similarly to the HTS machines involving 1G or 2G wires, the trapped field of the bulk is possibly sensitive and even can be attenuated by the AC component field during the operation. Hence, it is necessary to recover the trapped field once being decreased to some extent in the practical application. From this point, we have investigated the trapped field recovery of HTS bulk magnets by static field magnetization in the paper. A series of different initial trapped fields after zero-field-cooling or field-cooling magnetization are used to simulate the attenuated trapped field. By comparing the trapped field peak and its distribution, the trapped field was found to be able to recover by the static field magnetization method with a stronger excitation field and the initial trapped flux inside the bulk also has an influence on the recovery process. The optimum recovery field was found to be about 2.5 times the saturated trapped field of the bulk at liquid nitrogen temperature, by which the bulk can regain the former best trapped field performance.

  7. Elucidating the Function of Penetratin and a Static Magnetic Field in Cellular Uptake of Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    David Stirling

    2013-02-01

    Full Text Available Nanotechnology plays an increasingly important role in the biomedical arena. In particular, magnetic nanoparticles (mNPs have become important tools in molecular diagnostics, in vivo imaging and improved treatment of disease, with the ultimate aim of producing a more theranostic approach. Due to their small sizes, the nanoparticles can cross most of the biological barriers such as the blood vessels and the blood brain barrier, thus providing ubiquitous access to most tissues. In all biomedical applications maximum nanoparticle uptake into cells is required. Two promising methods employed to this end include functionalization of mNPs with cell-penetrating peptides to promote efficient translocation of cargo into the cell and the use of external magnetic fields for enhanced delivery. This study aimed to compare the effect of both penetratin and a static magnetic field with regards to the cellular uptake of 200 nm magnetic NPs and determine the route of uptake by both methods. Results demonstrated that both techniques increased particle uptake, with penetratin proving more cell specific. Clathrin- medicated endocytosis appeared to be responsible for uptake as shown via PCR and western blot, with Pitstop 2 (known to selectively block clathrin formation blocking particle uptake. Interestingly, it was further shown that a magnetic field was able to reverse or overcome the blocking, suggesting an alternative route of uptake.

  8. High intensity circular proton accelerators

    International Nuclear Information System (INIS)

    Craddock, M.K.

    1987-12-01

    Circular machines suitable for the acceleration of high intensity proton beams include cyclotrons, FFAG accelerators, and strong-focusing synchrotrons. This paper discusses considerations affecting the design of such machines for high intensity, especially space charge effects and the role of beam brightness in multistage accelerators. Current plans for building a new generation of high intensity 'kaon factories' are reviewed. 47 refs

  9. The realization of strong, stray static magnetic fields

    Czech Academy of Sciences Publication Activity Database

    Žežulka, Václav; Straka, Pavel

    2012-01-01

    Roč. 9, č. 1 (2012), s. 71-77 ISSN 1214-9705 Institutional research plan: CEZ:AV0Z30460519 Keywords : magnetic fields * magnetic circuits * permanent NdFeB magnets Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.530, year: 2011 http://www.irsm.cas.cz/materialy/acta_content/2012_01/7_Zezulka.pdf

  10. Static magnetic fields: A summary of biological interactions, potential health effects, and exposure guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Tenforde, T.S.

    1992-05-01

    Interest in the mechanisms of interaction and the biological effects of static magnetic fields has increased significantly during the past two decades as a result of the growing number of applications of these fields in research, industry and medicine. A major stimulus for research on the bioeffects of static magnetic fields has been the effort to develop new technologies for energy production and storage that utilize intense magnetic fields (e.g., thermonuclear fusion reactors and superconducting magnet energy storage devices). Interest in the possible biological interactions and health effects of static magnetic fields has also been increased as a result of recent developments in magnetic levitation as a mode of public transportation. In addition, the rapid emergence of magnetic resonance imaging as a new clinical diagnostic procedure has, in recent years, provided a strong rationale for defining the possible biological effects of magnetic fields with high flux densities. In this review, the principal interaction mechanisms of static magnetic fields will be described, and a summary will be given of the present state of knowledge of the biological, environmental, and human health effects of these fields.

  11. Computational Analysis of Static and Dynamic Behaviour of Magnetic Suspensions and Magnetic Bearings

    Science.gov (United States)

    Britcher, Colin P. (Editor); Groom, Nelson J.

    1996-01-01

    Static modelling of magnetic bearings is often carried out using magnetic circuit theory. This theory cannot easily include nonlinear effects such as magnetic saturation or the fringing of flux in air-gaps. Modern computational tools are able to accurately model complex magnetic bearing geometries, provided some care is exercised. In magnetic suspension applications, the magnetic fields are highly three-dimensional and require computational tools for the solution of most problems of interest. The dynamics of a magnetic bearing or magnetic suspension system can be strongly affected by eddy currents. Eddy currents are present whenever a time-varying magnetic flux penetrates a conducting medium. The direction of flow of the eddy current is such as to reduce the rate-of-change of flux. Analytic solutions for eddy currents are available for some simplified geometries, but complex geometries must be solved by computation. It is only in recent years that such computations have been considered truly practical. At NASA Langley Research Center, state-of-the-art finite-element computer codes, 'OPERA', 'TOSCA' and 'ELEKTRA' have recently been installed and applied to the magnetostatic and eddy current problems. This paper reviews results of theoretical analyses which suggest general forms of mathematical models for eddy currents, together with computational results. A simplified circuit-based eddy current model proposed appears to predict the observed trends in the case of large eddy current circuits in conducting non-magnetic material. A much more difficult case is seen to be that of eddy currents in magnetic material, or in non-magnetic material at higher frequencies, due to the lower skin depths. Even here, the dissipative behavior has been shown to yield at least somewhat to linear modelling. Magnetostatic and eddy current computations have been carried out relating to the Annular Suspension and Pointing System, a prototype for a space payload pointing and vibration

  12. Static high-gradient magnetic fields affect the functionality of monocytic cells

    Czech Academy of Sciences Publication Activity Database

    Syrovets, T.; Schmidt, Z.; Buechele, B.; Zablotskyy, Vitaliy A.; Dejneka, Alexandr; Dempsey, N.; Simmet, T.

    2014-01-01

    Roč. 28, č. 1 (2014), s. 1-2 ISSN 0892-6638 Institutional support: RVO:68378271 Keywords : static high-gradient * magnet ic fields * affect the functionality * monocytic cells Subject RIV: BM - Solid Matter Physics ; Magnet ism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.)

  13. Working with MRI: An investigation of occupational exposure to strong static magnetic fields and associated symptoms

    NARCIS (Netherlands)

    Schaap, K.

    2015-01-01

    Magnetic resonance imaging (MRI) makes use of electromagnetic fields in the non-ionizing radiation frequency ranges. One of them is a continuously present strong static magnetic field (SMF), which extends up to several meters around the scanner. Each time an MRI worker performs tasks near the

  14. Passive magnetic cylindrical shielding at gauss-range static fields

    International Nuclear Information System (INIS)

    Calvo, E.; Cerrada, M.; Gil-Botella, I.; Palomares, C.; Rodriguez, I.; Toral, F.; Verdugo, A.

    2009-01-01

    A study has been performed in order to find the optimal solution for the magnetic shielding of the 10 in. photomultipliers which will be used in the Double Chooz neutrino experiment under a very low magnetic field (less than 2 G). The results obtained with analytical and numerical calculations are compared with measurements made using test prototypes of several magnetic materials, with different dimensions and from different manufacturers. An exhaustive analysis of the magnetic materials was needed to understand the observed disagreement between calculations and test results obtained at low field values.

  15. Learning about static electricity and magnetism in a fourth-grade classroom

    Science.gov (United States)

    Henry, David Roy

    Students begin to develop mental models to explain electrostatic and magnetic phenomena throughout childhood, middle childhood and high school, although these mental models are often incoherent and unscientific (Borges, Tenico, & Gilbert, 1998; Maloney, 1985). This is a case study of a classroom of grade four students and the mental models of magnetism and static electricity they used during a six-week science unit. The 22 students studied magnetism and static electricity using inquiry activities structured to create an environment where students would be likely to construct powerful scientific ideas (Goldberg & Bendall, 1995). Multiple data sources, including students' writing, student assessments, teacher interviews, student interviews, teacher journals, and classroom video and audio recordings were used to uncover how fourth grade students made sense of static electricity and magnetism before, during, and after instruction. The data were analyzed using a social constructivist framework to determine if students were able to develop target scientific ideas about static electricity and magnetism. In general, students were found to have three core mental models prior to instruction: (1) Static electricity and magnetism are the same "substance"; (2) This substance exists on the surface of a magnet or a charged object and can be rubbed off, and (3) Opposite substances attract. During the activities, students had many opportunities to observe evidence that contradicted these core mental models. Using evidence from direct observations, the students practiced differentiating between evidence and ideas. Through group and class discussions, they developed evidenced-based (scientific) ideas. Final assessments revealed that students were able to construct target ideas such as: (1) static electricity and magnetism are fundamentally different; (2) there are two kinds of static "charge;" (3) magnet-rubbed wires act like a magnet; and (4) opposite substances move toward each

  16. Metal magnetic memory effect caused by static tension load in a case-hardened steel

    International Nuclear Information System (INIS)

    Shi, C.L.; Dong, S.Y.; Xu, B.S.; He, P.

    2010-01-01

    For investigating the magnetic abnormality influenced by stress in ferromagnetic materials, static tension tests on a case-hardened steel were carried out. Different loads, which covered tensile elastic loads up to plastic deformation and break, were applied. Meanwhile, the normal component of magnetic flux leakage, H p (y), was measured by metal magnetic memory testing. The results indicate that H p (y) values change with the tensile loads and positions. There exists a relationship between k, which is the inclination of the linear amplitude-locus magnetic flux leakage curve, and static tension load. A simple model is derived. Additionally, the mechanism of the magnetic memory effect can be explained by the theory of the interaction between dislocations and domains. The research provides the potential possibility of quantitative inspection for metal magnetic memory testing.

  17. Impact of Static Magnetic Field on the Antioxidant Defence System of Mice Fibroblasts

    Directory of Open Access Journals (Sweden)

    Marek Glinka

    2018-01-01

    Full Text Available Results of research assessing the biological impact of static magnetic fields are controversial. So far, they have not provided a clear answer to their influence on cell functioning. Since the use of permanent magnets both in everyday life and in industry becomes more and more widespread, the investigations are continued in order to explain these controversies and to evaluate positive applications. The goal of current work was to assess the impact of static magnetic field of different intensities on redox homeostasis in cultures of fibroblasts. The use of permanent magnets allowed avoiding the thermal effects which are present in electromagnets. During the research we used 6 chambers, designed exclusively by us, with different values of field flux density (varying from 0.1 to 0.7 T. We have noted the decrease in the activity of superoxide dismutase (SOD and glutathione peroxidase (GPx. The static magnetic fields did not modify the energy state of fibroblasts— adenosine triphosphate (ATP concentration was stable, as well as the generation of malondialdehyde (MDA—which is a marker of oxidative stress. Results of research suggest that static magnetic fields generated by permanent magnets do not cause oxidative stress in investigated fibroblasts and that they may show slight antioxidizing activity.

  18. Linear stability analysis of a levitated nanomagnet in a static magnetic field: Quantum spin stabilized magnetic levitation

    Science.gov (United States)

    Rusconi, C. C.; Pöchhacker, V.; Cirac, J. I.; Romero-Isart, O.

    2017-10-01

    We theoretically study the levitation of a single magnetic domain nanosphere in an external static magnetic field. We show that, apart from the stability provided by the mechanical rotation of the nanomagnet (as in the classical Levitron), the quantum spin origin of its magnetization provides two additional mechanisms to stably levitate the system. Despite the Earnshaw theorem, such stable phases are present even in the absence of mechanical rotation. For large magnetic fields, the Larmor precession of the quantum magnetic moment stabilizes the system in full analogy with magnetic trapping of a neutral atom. For low magnetic fields, the magnetic anisotropy stabilizes the system via the Einstein-de Haas effect. These results are obtained with a linear stability analysis of a single magnetic domain rigid nanosphere with uniaxial anisotropy in a Ioffe-Pritchard magnetic field.

  19. Reconstruction of the static magnetic field of a magnetron

    Science.gov (United States)

    Krüger, Dennis; Köhn, Kevin; Gallian, Sara; Brinkmann, Ralf Peter

    2018-06-01

    The simulation of magnetron discharges requires a quantitatively correct mathematical model of the magnetic field structure. This study presents a method to construct such a model on the basis of a spatially restricted set of experimental data and a plausible a priori assumption on the magnetic field configuration. The example in focus is that of a planar circular magnetron. The experimental data are Hall probe measurements of the magnetic flux density in an accessible region above the magnetron plane [P. D. Machura et al., Plasma Sources Sci. Technol. 23, 065043 (2014)]. The a priori assumption reflects the actual design of the device, and it takes the magnetic field emerging from a center magnet of strength m C and vertical position d C and a ring magnet of strength m R , vertical position d R , and radius R. An analytical representation of the assumed field configuration can be formulated in terms of generalized hypergeometric functions. Fitting the ansatz to the experimental data with a least square method results in a fully specified analytical field model that agrees well with the data inside the accessible region and, moreover, is physically plausible in the regions outside of it. The outcome proves superior to the result of an alternative approach which starts from a multimode solution of the vacuum field problem formulated in terms of polar Bessel functions and vertical exponentials. As a first application of the obtained field model, typical electron and ion Larmor radii and the gradient and curvature drift velocities of the electron guiding center are calculated.

  20. Magnetic Resonance-Guided High-Intensity Focused Ultrasound (MRgHIFU) for Treatment of Symptomatic Uterine Fibroids: An Economic Analysis

    Science.gov (United States)

    Babashov, V; Palimaka, S; Blackhouse, G; O'Reilly, D

    2015-01-01

    Background Uterine fibroids, or leiomyomas, are the most common benign tumours in women of childbearing age. Some women experience symptoms (e.g., heavy bleeding) that require aggressive forms of treatment such as uterine artery embolization (UAE), myomectomy, magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU), and even hysterectomy. It is important to note that hysterectomy is not appropriate for women who desire future childbearing. Objectives The objective of this analysis was to evaluate the cost-effectiveness and budgetary impact of implementing MRgHIFU as a treatment option for symptomatic uterine fibroids in premenopausal women for whom drugs have been ineffective. Review Methods We performed an original cost-effectiveness analysis to assess the long-term costs and effects of MRgHIFU compared with hysterectomy, myomectomy, and UAE as a strategy for treating symptomatic uterine fibroids in premenopausal women aged 40 to 51 years. We explored a number of scenarios, e.g., comparing MRgHIFU with uterine-preserving procedures only, considering MRgHIFU-eligible patients only, and eliminating UAE as a treatment option. In addition, we performed a one-year budget impact analysis, using data from Ontario administrative sources. Four scenarios were explored in the budgetary impact analysis: MRgHIFU funded at 2 centres MRgHIFU funded at 2 centres and replacing only uterine-preserving procedures MRgHIFU funded at 6 centres MRgHIFU funded at 6 centres and replacing only uterine-preserving procedures Analyses were conducted from the Ontario public payer perspective. Results The base case determined that the uterine artery embolization (UAE) treatment strategy was the cost-effective option at commonly accepted willingness-to-pay values. Compared with hysterectomy, UAE was calculated as having an incremental cost-effectiveness ratio (ICER) of $46,480 per quality-adjusted life-year (QALY) gained. The MRgHIFU strategy was extendedly dominated by a

  1. LHC Report: reaching high intensity

    CERN Multimedia

    Jan Uythoven

    2015-01-01

    After both beams having been ramped to their full energy of 6.5 TeV, the last two weeks saw the beam commissioning process advancing on many fronts. An important milestone was achieved when operators succeeded in circulating a nominal-intensity bunch. During the operation, some sudden beam losses resulted in beam dumps at top energy, a problem that needed to be understood and resolved.   In 2015 the LHC will be circulating around 2800 bunches in each beam and each bunch will contain just over 1 x 1011 protons. Until a few days ago commissioning was taking place with single bunches of 5 x 109 protons. The first nominal bunch with an intensity of 1 x 1011 protons was injected on Tuesday, 21 April. In order to circulate such a high-intensity bunch safely, the whole protection system must be working correctly: collimators, which protect the aperture, are set at preliminary values known as coarse settings; all kicker magnets for injecting and extracting the beams are commissioned with beam an...

  2. Manipulating beams of ultra-cold atoms with a static magnetic field

    International Nuclear Information System (INIS)

    Rowlands, W.J.; Lau, D.C.; Opat, G.I.; Sidorov, A.I.; McLean, R.J.; Hannaford, P.

    1996-01-01

    The preliminary results on the deflection of a beam of ultra-cold atoms by a static magnetic field are presented. Caesium atoms trapped in a magneto-optical trap (MOT) are cooled using optical molasses, and then fall freely under gravity to form a beam of ultra-cold atoms. The atoms pass through a static inhomogeneous magnetic field produced by a single current-carrying wire, and are deflected by a force dependent on the magnetic substate of the atom. A schematical diagram of the experimental layout for laser trapping and cooling of cesium atom is given. The population of atoms in various magnetic substates can be altered by using resonant laser radiation to optically pump the atoms. The single-wire deflection experiment described can be considered as atomic reflexion from a cylindrical magnetic mirror; the underlying principles and techniques being relevant to the production of atomic mirrors and diffraction gratings. 16 refs., 10 figs

  3. Dosimetry in clinical static magnetic fields using plastic scintillation detectors

    DEFF Research Database (Denmark)

    Stefanowicz, S.; Latzel, H.; Lindvold, Lars René

    2013-01-01

    . In conclusion, we found some deviations up to 7% of the supposed signal. Although the scintillators are of much denser material, we measured the same behavior in signal as in (Meijsing et al., 2009) for a Farmer ionization chamber or as in (Raaijmakers et al., 2007) for films described which indicates radiation......-vivo dosimetry in radiation treatments and diagnostics and could be, being all-optical, promising candidates for this application. To study the basic feasibility of using PSDs with organic scintillators in magnetic fields, we measured the response of these dosimeters in presence of magnetic fields up to 1 T...

  4. Static fluid magnetic resonance urography in evaluation of ureteral ...

    African Journals Online (AJOL)

    Introduction: Ectopic ureters are often very difficult to diagnose with conventional imaging modalities especially in children. Magnetic resonance urography (MRU) has been recently investigated as a problem-solving tool for the evaluation of various congenital urogenital anomalies with favorable results. Aim of the work: To ...

  5. Static field influences on transcranial magnetic stimulation: considerations for TMS in the scanner environment.

    Science.gov (United States)

    Yau, Jeffrey M; Jalinous, Reza; Cantarero, Gabriela L; Desmond, John E

    2014-01-01

    Transcranial magnetic stimulation (TMS) can be combined with functional magnetic resonance imaging (fMRI) to simultaneously manipulate and monitor human cortical responses. Although tremendous efforts have been directed at characterizing the impact of TMS on image acquisition, the influence of the scanner's static field on the TMS coil has received limited attention. The aim of this study was to characterize the influence of the scanner's static field on TMS. We hypothesized that spatial variations in the static field could account for TMS field variations in the scanner environment. Using an MRI-compatible TMS coil, we estimated TMS field strengths based on TMS-induced voltage changes measured in a search coil. We compared peak field strengths obtained with the TMS coil positioned at different locations (B0 field vs fringe field) and orientations in the static field. We also measured the scanner's static field to derive a field map to account for TMS field variations. TMS field strength scaled depending on coil location and orientation with respect to the static field. Larger TMS field variations were observed in fringe field regions near the gantry as compared to regions inside the bore or further removed from the bore. The scanner's static field also exhibited the greatest spatial variations in fringe field regions near the gantry. The scanner's static field influences TMS fields and spatial variations in the static field correlate with TMS field variations. Coil orientation changes in the B0 field did not result in substantial TMS field variations. TMS field variations can be minimized by delivering TMS in the bore or outside of the 0-70 cm region from the bore entrance. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Geomagnetic and strong static magnetic field effects on growth and chlorophyll a fluorescence in Lemna minor.

    Science.gov (United States)

    Jan, Luka; Fefer, Dušan; Košmelj, Katarina; Gaberščik, Alenka; Jerman, Igor

    2015-04-01

    The geomagnetic field (GMF) varies over Earth's surface and changes over time, but it is generally not considered as a factor that could influence plant growth. The effects of reduced and enhanced GMFs and a strong static magnetic field on growth and chlorophyll a (Chl a) fluorescence of Lemna minor plants were investigated under controlled conditions. A standard 7 day test was conducted in extreme geomagnetic environments of 4 µT and 100 µT as well as in a strong static magnetic field environment of 150 mT. Specific growth rates as well as slow and fast Chl a fluorescence kinetics were measured after 7 days incubation. The results, compared to those of controls, showed that the reduced GMF significantly stimulated growth rate of the total frond area in the magnetically treated plants. However, the enhanced GMF pointed towards inhibition of growth rate in exposed plants in comparison to control, but the difference was not statistically significant. This trend was not observed in the case of treatments with strong static magnetic fields. Our measurements suggest that the efficiency of photosystem II is not affected by variations in GMF. In contrast, the strong static magnetic field seems to have the potential to increase initial Chl a fluorescence and energy dissipation in Lemna minor plants. © 2015 Wiley Periodicals, Inc.

  7. Influence of static magnetic fields on S. cerevisae biomass growth

    Directory of Open Access Journals (Sweden)

    João B. Muniz

    2007-05-01

    Full Text Available Biomass growth of Saccharomyces cerevisiae DAUFPE-1012 was studied in eight batch fermentations exposed to steady magnetic fields (SMF running at 23ºC (± 1ºC, for 24 h in a double cylindrical tube reactor with synchronic agitation. For every batch, one tube was exposed to 220mT flow intensity SMF, produced by NdFeB rod magnets attached diametrically opposed (N to S magnets on one tube. In the other tube, without magnets, the fermentation occurred in the same conditions. The biomass growth in culture (yeast extract + glucose 2% was monitored by spectrometry to obtain the absorbance and later, the corresponding cell dry weight. The culture glucose concentration was monitored every two hours so as the pH, which was maintained between 4 and 5. As a result, the biomass (g/L increment was 2.5 times greater in magnetized cultures (n=8 as compared with SMF non-exposed cultures (n=8. The differential (SMF-control biomass growth rate (135% was slightly higher than the glucose consumption rate (130 % leading to increased biomass production of the magnetized cells.O crescimento da biomassa da Saccharomyces cerevisiae DAUFPE-1012 foi estudado em oito bateladas de fermentação, cada uma exposta aos campos magnéticos contínuos (CMC, à 23ºC (± 1ºC, durante um período de 24 horas em um reator duplo com agitação sincrônica. Em cada batelada,um tubo foi exposto ao CMC, com 220mT de intensidade de fluxo, produzidos por imãs de NdFeB fixados diametralmente opostos (N para S em um tubo do reator de fermentação. Em outro tubo, sem imãs, a fermentação ocorreu nas mesmas condições. O crescimento da biomassa nas culturas (extrato de fermento + glicose 2% foi monitorado através de espectrometria e correlacionado ao peso seco de levedura. A concentração de glicose nas culturas foi monitorada a cada duas horas e o pH foi mantido entre 4 e 5. Como resultado, a biomassa (g/L aumentou 2,5 vezes nas culturas magnetizadas (n=8 quando comparadas com as

  8. Applications, dosimetry and biological interactions of static and time-varying magnetic fields

    International Nuclear Information System (INIS)

    Tenforde, T.S.

    1988-08-01

    The primary topics of this presentation include: (1) the applications of magnetic fields in research, industry, and medical technologies; (2) mechanisms of interaction of static and time-varying magnetic fields with living systems; (3) human health effects of exposure to static and time-varying magnetic fields in occupational, medical, and residential settings; and (4) recent advances in the dosimetry of extremely-low-frequency electromagnetic fields. The discussion of these topics is centered about two issues of considerable contemporary interest: (1) potential health effects of the fields used in magnetic resonance imaging and in vivo spectroscopy, and (2) the controversial issue of whether exposure to extremely-low-frequency (ELF) electromagnetic fields in the home and workplace leads to an elevated risk of cancer. 11 refs

  9. The Static Eccentricity Fault Diagnosis in Time Domain at Line Start Permanent Magnet Synchronous Motor

    OpenAIRE

    DOGAN, Zafer

    2016-01-01

    Recently, Line Start Permanent Magnet Synchronous Motor have been commonly utilized in industrial areas because of their high efficiency. Motor faults during operation cause losses of production and high maintenance and repair expenditures. In this study, the effect of static eccentricity fault on line start permanent magnet synchronous motor was investigated. The simulation models of motor belonging to healthy and fault status were formed via Finite Elements Method. The analyses in time doma...

  10. Static magnetic susceptibility of radiopaque NiTiPt and NiTiEr

    Science.gov (United States)

    Chovan, Drahomír; Gandhi, Abbasi; Butler, James; Tofail, Syed A. M.

    2018-04-01

    Magnetic properties of metallic alloys used in biomedical industry are important for the magnetic resonance imaging (MRI). If the alloys were to be used for long term implants or as guiding devices, safety of the patient as well as the medical staff has to be ensured. Strong response to the external magnetic field can cause mechanical damage to the patients body. In this paper we present magnetic susceptibility of nickel rich, ternary NiTiPt and NiTiEr to static magnetic field. We show that the magnetic susceptibility of these radiopaque alloys has values in low paramagnetic region comparable to the binary nickel-titanium. Furthermore, we studied the effect of the thermal and mechanical treatments on magnetic properties. Despite deviation from linear M (H) treated samples spanning small region around H = 0 , the linearity of the M (H) and χ =d M /d H values suggest that these ternary alloys are safe to use under MRI conditions.

  11. Compton scattering at high intensities

    Energy Technology Data Exchange (ETDEWEB)

    Heinzl, Thomas, E-mail: thomas.heinzl@plymouth.ac.u [University of Plymouth, School of Mathematics and Statistics, Drake Circus, Plymouth PL4 8AA (United Kingdom)

    2009-12-01

    High-intensity Compton scattering takes place when an electron beam is brought into collision with a high power laser. We briefly review the main intensity signatures using the formalism of strong-field quantum electrodynamics.

  12. Effect of a static magnetic field on Escherichia coli adhesion and orientation

    Czech Academy of Sciences Publication Activity Database

    Mhamdi, L.; Mhamdi, N.; Mhamdi, Nc.; Lejeune, M.; Jaffrezic, N.; Burais, N.; Scorretti, R.; Pokorný, Jiří; Ponsonnet, L.

    2016-01-01

    Roč. 62, č. 11 (2016), s. 944-952 ISSN 0008-4166 Institutional support: RVO:67985882 Keywords : Fluorescence microscopy * Static magnetic field * Escherichia coli Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.462, year: 2016

  13. Static properties of small Josephson tunnel junctions in an oblique magnetic field

    DEFF Research Database (Denmark)

    Monaco, Roberto; Aarøe, Morten; Mygind, Jesper

    2009-01-01

    We have carried out a detailed experimental investigation of the static properties of planar Josephson tunnel junctions in presence of a uniform external magnetic field applied in an arbitrary orientation with respect to the barrier plane. We considered annular junctions, as well as rectangular...

  14. Genotoxic Effects of Superconducting Static Magnetic Fields (SMFs) on Wheat (Triticum aestivum) Pollen Mother Cells (PMCs)

    International Nuclear Information System (INIS)

    Zhang Pingping; Yin Ruochun; Chen Zhiyou; Wu Lifang; Yu Zengliang

    2007-01-01

    The effects of superconducting static magnetic fields (SMFs) on the pollen mother cells (PMCs) of wheat were investigated in order to evaluate the possible genotoxic effect of such non-ionizing radiation. The seeds of wheat were exposed to static magnetic fields with either different magnetic flux densities (0, 1, 3, 5 and 7 Tesla) for 5 h or different durations (1, 3 and 5 h) at a magnetic flux density of 7 Tesla. The seeds were germinated at 23 o C after exposure and the seedlings were transplanted into the field. The PMCs from young wheat ears were taken and slides were made following the conventional method. The genotoxic effect was evaluated in terms of micronucleus (MN), chromosomal bridge, lagging chromosome and fragments in PMCs. Although the exposed groups of a low field intensity (below 5 Tesla) showed no statistically significant difference in the aberration frequency compared with the unexposed control groups and sham exposed groups, a significant increase in the chromosomal bridge, lagging chromosome, triple-polar segregation or micronucleus was observed at a field strength of 5 Tesla or 7 Tesla, respectively. The analysis of dose-effect relationships indicated that the increased frequency of meiotic abnormal cells correlated with the flux density of the magnetic field and duration, but no linear relationship was observed. Such statistically significant differences indicated a potential genotoxic effect of high static magnetic fields above 5 T

  15. Genotoxic Effects of Superconducting Static Magnetic Fields (SMFs) on Wheat (Triticum aestivum) Pollen Mother Cells (PMCs)

    Science.gov (United States)

    Zhang, Pingping; Yin, Ruochun; Chen, Zhiyou; Wu, Lifang; Yu, Zengliang

    2007-04-01

    The effects of superconducting static magnetic fields (SMFs) on the pollen mother cells (PMCs) of wheat were investigated in order to evaluate the possible genotoxic effect of such non-ionizing radiation. The seeds of wheat were exposed to static magnetic fields with either different magnetic flux densities (0, 1, 3, 5 and 7 Tesla) for 5 h or different durations (1, 3 and 5 h) at a magnetic flux density of 7 Tesla. The seeds were germinated at 23oC after exposure and the seedlings were transplanted into the field. The PMCs from young wheat ears were taken and slides were made following the conventional method. The genotoxic effect was evaluated in terms of micronucleus (MN), chromosomal bridge, lagging chromosome and fragments in PMCs. Although the exposed groups of a low field intensity (below 5 Tesla) showed no statistically significant difference in the aberration frequency compared with the unexposed control groups and sham exposed groups, a significant increase in the chromosomal bridge, lagging chromosome, triple-polar segregation or micronucleus was observed at a field strength of 5 Tesla or 7 Tesla, respectively. The analysis of dose-effect relationships indicated that the increased frequency of meiotic abnormal cells correlated with the flux density of the magnetic field and duration, but no linear relationship was observed. Such statistically significant differences indicated a potential genotoxic effect of high static magnetic fields above 5 T.

  16. Mammals' response and adaptation to static magnetic fields as a nonspecific stressor

    Science.gov (United States)

    Nakagawa, Masayoshi

    1990-06-01

    Biological effects of static magnetic fields are still unclear and sometimes contradictory, and it has not been possible to connect this situation directly to some explanations of the mechanisms of the effects of static magnetic fields at the molecular level. Some researchers have pointed out that the process through which animals respond at the whole-body level to static magnetic fields follows the same pattern as the GAS (general adaptation syndrome) described by Selye. This biological or behavioral pattern is considered to be a common process followed by animals which are affected by environmental stimulants; they are depressed first, then surpass the deteriorated conditions and recover their normal conditions, or sometimes overshoot it. When this process is observed with mammals subjected to the magnetic fields, it can be concluded that magnetism has affected the organism. In this paper, the author reviews reports in which magnetic field density and minimum exposure time were determined with certain effects produced under certain conditions, and proposes a regression model for estimating the minimum amount of exposure which produces some effect on mammals.

  17. Magnetic resonance imaging. Recent studies on biological effects of static magnetic and high-frequency electromagnetic fields

    International Nuclear Information System (INIS)

    Pophof, B.; Brix, G.

    2017-01-01

    During the last few years, new studies on biological effects of strong static magnetic fields and on thermal effects of high-frequency electromagnetic fields used in magnetic resonance imaging (MRI) were published. Many of these studies have not yet been included in the current safety recommendations. Scientific publications since 2010 on biological effects of static and electromagnetic fields in MRI were researched and evaluated. New studies confirm older publications that have already described effects of static magnetic fields on sensory organs and the central nervous system, accompanied by sensory perceptions. A new result is the direct effect of Lorentz forces on ionic currents in the semicircular canals of the vestibular system. Recent studies of thermal effects of high-frequency electromagnetic fields were focused on the development of anatomically realistic body models and a more precise simulation of exposure scenarios. Strong static magnetic fields can cause unpleasant sensations, in particular, vertigo. In addition, they can influence the performance of the medical staff and thus potentially endanger the patient's safety. As a precaution, medical personnel should move slowly within the field gradient. High-frequency electromagnetic fields lead to an increase in the temperature of patients' tissues and organs. This should be considered especially in patients with restricted thermoregulation and in pregnant women and neonates; in these cases exposure should be kept as low as possible. (orig.) [de

  18. Endoluminal ultrasound applicator with an integrated RF coil for high-resolution magnetic resonance imaging-guided high-intensity contact ultrasound thermotherapy

    International Nuclear Information System (INIS)

    Rata, Mihaela; Salomir, Rares; Lafon, Cyril; Umathum, Reiner; Jenne, Juergen; Bock, Michael; Cotton, Francois

    2008-01-01

    High-intensity contact ultrasound (HICU) under MRI guidance may provide minimally invasive treatment of endocavitary digestive tumors in the esophagus, colon or rectum. In this study, a miniature receive-only coil was integrated into an endoscopic ultrasound applicator to offer high-resolution MRI guidance of thermotherapy. A cylindrical plastic support with an incorporated single element flat transducer (9.45 MHz, water cooling tip) was made and equipped with a rectangular RF loop coil surrounding the active element. The integrated coil provided significantly higher sensitivity than a four-element extracorporeal phased array coil, and the standard deviation of the MR thermometry (SDT) improved up to a factor of 7 at 10 mm depth in tissue. High-resolution morphological images (T1w-TFE and IR-T1w-TSE with a voxel size of 0.25 x 0.25 x 3 mm 3 ) and accurate thermometry data (the PRFS method with a voxel size of 0.5 x 0.5 x 5 mm 3 , 2.2 s/image, 0.3 deg. C voxel-wise SDT) were acquired in an ex vivo esophagus sample, on a clinical 1.5T scanner. The endoscopic device was actively operated under automatic temperature control, demonstrating a high level of accuracy (1.7% standard deviation, 1.1% error of mean value), which indicates that this technology may be suitable for HICU therapy of endoluminal cancer.

  19. Endoluminal ultrasound applicator with an integrated RF coil for high-resolution magnetic resonance imaging-guided high-intensity contact ultrasound thermotherapy

    Science.gov (United States)

    Rata, Mihaela; Salomir, Rares; Umathum, Reiner; Jenne, Jürgen; Lafon, Cyril; Cotton, François; Bock, Michael

    2008-11-01

    High-intensity contact ultrasound (HICU) under MRI guidance may provide minimally invasive treatment of endocavitary digestive tumors in the esophagus, colon or rectum. In this study, a miniature receive-only coil was integrated into an endoscopic ultrasound applicator to offer high-resolution MRI guidance of thermotherapy. A cylindrical plastic support with an incorporated single element flat transducer (9.45 MHz, water cooling tip) was made and equipped with a rectangular RF loop coil surrounding the active element. The integrated coil provided significantly higher sensitivity than a four-element extracorporeal phased array coil, and the standard deviation of the MR thermometry (SDT) improved up to a factor of 7 at 10 mm depth in tissue. High-resolution morphological images (T1w-TFE and IR-T1w-TSE with a voxel size of 0.25 × 0.25 × 3 mm3) and accurate thermometry data (the PRFS method with a voxel size of 0.5 × 0.5 × 5 mm3, 2.2 s/image, 0.3 °C voxel-wise SDT) were acquired in an ex vivo esophagus sample, on a clinical 1.5T scanner. The endoscopic device was actively operated under automatic temperature control, demonstrating a high level of accuracy (1.7% standard deviation, 1.1% error of mean value), which indicates that this technology may be suitable for HICU therapy of endoluminal cancer.

  20. Vacuum polarisation in some static nonuniform magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Calucci, G. [Trieste Univ. (Italy). Dip. di Fisica Teorica]|[INFN, Trieste (Italy)

    1995-11-01

    Vacuum polarisation in QED in presence of some configurations of external magnetic fields is investigated. The configuration considered correspond to fields is investigated. The configuration considered correspond to fields lying in a plane and without sources. The motion of a Dirac electron in this field configuration is studied and arguments are found to conclude that the lowest level gives the most important contribution. The result is that the main effect is not very different from the uniform case, the possibilities of calculating the corrections due to the uniformity is explicitly shown. A typical effect of nonuniformity of the field shows out in the refractivity of the field shows out in the refractivity of the vacuum.

  1. Vacuum polarisation in some static nonuniform magnetic fields

    International Nuclear Information System (INIS)

    Calucci, G.

    1995-11-01

    Vacuum polarisation in QED in presence of some configurations of external magnetic fields is investigated. The configuration considered correspond to fields is investigated. The configuration considered correspond to fields lying in a plane and without sources. The motion of a Dirac electron in this field configuration is studied and arguments are found to conclude that the lowest level gives the most important contribution. The result is that the main effect is not very different from the uniform case, the possibilities of calculating the corrections due to the uniformity is explicitly shown. A typical effect of nonuniformity of the field shows out in the refractivity of the field shows out in the refractivity of the vacuum

  2. From static to rotating to conformal static solutions: rotating imperfect fluid wormholes with(out) electric or magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Azreg-Ainou, Mustapha [Baskent University, Department of Mathematics, Ankara (Turkey)

    2014-05-15

    We derive a shortcut stationary metric formula for generating imperfect fluid rotating solutions, in Boyer-Lindquist coordinates, from spherically symmetric static ones. We explore the properties of the curvature scalar and stress-energy tensor for all types of rotating regular solutions we can generate without restricting ourselves to specific examples of regular solutions (regular black holes or wormholes). We show through examples how it is generally possible to generate an imperfect fluid regular rotating solution via radial coordinate transformations. We derive rotating wormholes that are modeled as imperfect fluids and discuss their physical properties. These are independent on the way the stress-energy tensor is interpreted. A solution modeling an imperfect fluid rotating loop black hole is briefly discussed. We then specialize to the recently discussed stable exotic dust Ellis wormhole as emerged in a source-free radial electric or magnetic field, and we generate its, conjecturally stable, rotating counterpart. This turns out to be an exotic imperfect fluid wormhole, and we determine the stress-energy tensor of both the imperfect fluid and the electric or magnetic field. (orig.)

  3. From static to rotating to conformal static solutions: rotating imperfect fluid wormholes with(out) electric or magnetic field

    International Nuclear Information System (INIS)

    Azreg-Ainou, Mustapha

    2014-01-01

    We derive a shortcut stationary metric formula for generating imperfect fluid rotating solutions, in Boyer-Lindquist coordinates, from spherically symmetric static ones. We explore the properties of the curvature scalar and stress-energy tensor for all types of rotating regular solutions we can generate without restricting ourselves to specific examples of regular solutions (regular black holes or wormholes). We show through examples how it is generally possible to generate an imperfect fluid regular rotating solution via radial coordinate transformations. We derive rotating wormholes that are modeled as imperfect fluids and discuss their physical properties. These are independent on the way the stress-energy tensor is interpreted. A solution modeling an imperfect fluid rotating loop black hole is briefly discussed. We then specialize to the recently discussed stable exotic dust Ellis wormhole as emerged in a source-free radial electric or magnetic field, and we generate its, conjecturally stable, rotating counterpart. This turns out to be an exotic imperfect fluid wormhole, and we determine the stress-energy tensor of both the imperfect fluid and the electric or magnetic field. (orig.)

  4. Static and dynamical anomalies caused by chiral soliton lattice in molecular-based chiral magnets

    International Nuclear Information System (INIS)

    Kishine, Jun-ichiro; Inoue, Katsuya; Kikuchi, Koichi

    2007-01-01

    Interplay of crystallographic chirality and magnetic chirality has been of great interest in both chemist's and physicist's viewpoints. Crystals belonging to chiral space groups are eligible to stabilize macroscopic chiral magnetic order. This class of magnetic order is described by the chiral XY model, where the transverse magnetic field perpendicular to the chiral axis causes the chiral soliton lattice (CSL) formation. As a clear evidence of the chiral magnetic order, the temperature dependence of the transverse magnetization exhibits sharp cusp just below the mean field ferrimagnetic transition temperature, indicating the formation of the CSL. In addition to the static anomaly, we expect the CSL formation also causes dynamical anomalies such as induction of the spin supercurrent

  5. Screening of the field of a static charge in an anisotropic magnetized plasma

    International Nuclear Information System (INIS)

    Arsenin, V.V.; Puzitskii, M.L.

    1991-01-01

    The field of a static charge placed in an equilibrium plasma is screened at a distance of the order of the Debye radius. Debye screening occurs both with and without an external magnetic field. This property also persists when the plasma is not an equilibrium plasma but the velocity distribution function of the particles is isotropic (the screening radius in this case contains the characteristic value of the energy instead of the temperature). The situation can change if the distribution is anisotropic. First, the drop in the field can become non-Debye. In particular, in an unmagnetized plasma some distribution functions are characterized by a power-law decrease of the field. Second, a static test charge induces a magnetic as well as an electrostatic field in an anisotropic plasma. In this communication the authors describe the anomalies of screening of the field of a static charge in a magnetized plasma. For definiteness they consider a situation (typical, e.g., of magnetic mirror systems) when the ionic component is anisotropic. The simplifications for the sake of computations are limited to the case of a charge which extends along the magnetic field and only harmonics much longer than the Debye length are significant in the Fourier expansion of the density of this charge in the longitudinal coordinate

  6. Effects of Static Magnetic Fields on the Physical, Mechanical, and Microstructural Properties of Cement Pastes

    Directory of Open Access Journals (Sweden)

    Juan J. Soto-Bernal

    2015-01-01

    Full Text Available This paper presents the results of an experimental study carried out to comprehend the physical, mechanical, and microstructural behavior of cement pastes subjected to static magnetic fields while hydrating and setting. The experimental methodology consisted in exposing fresh cement pastes to static magnetic fields at three different magnetic induction strengths: 19.07, 22.22, and 25.37 Gauss. The microstructural characterization makes evident that there are differences in relation to amount and morphology of CSH gel; the amount of CSH is larger and its morphology becomes denser and less porous with higher magnetostatic induction strengths; it also shows the evidence of changes in the mineralogical composition of the hydrated cement pastes. The temperature increasing has no negative effects over the cement paste compressive strength since the magnetostatic field affects the process of hydration through a molecular restructuring process, which makes cement pastes improve microstructurally, with a reduced porosity and a higher mechanical strength.

  7. Flux Trapping Properties of Bulk HIGH-TC Superconductors in Static Field-Cooling Magnetization

    Science.gov (United States)

    Deng, Z.; Tsuzuki, K.; Miki, M.; Felder, B.; Hara, S.; Izumi, M.

    2013-06-01

    The trapping process and saturation effect of trapped magnetic flux of bulk high-temperature superconductors by static field-cooling magnetization (FCM) are reported in the paper. With a cryogenic Bell Hall sensor attached on the center of the bulk surface, the synchronous magnetic signals were recorded during the whole magnetization process. It enables us to know the flux trapping behavior since the removal of the excitation field, as well as the subsequent flux relaxation phenomenon and the flux dissipation in the quench process of the bulk sample. With the help of flux mapping techniques, the relationship between the trapped flux and the applied field was further investigated; the saturation effect of trapped flux was discussed by comparing the peak trapped field and total magnetic flux of the bulk sample. These studies are useful to understand the basic flux trapping properties of bulk superconductors.

  8. Effect of horizontal strong static magnetic field on swimming behaviour of Paramecium caudatum

    Science.gov (United States)

    Fujiwara, Yoshihisa; Tomishige, Masahiko; Itoh, Yasuhiro; Fujiwara, Masao; Shibata, Naho; Kosaka, Toshikazu; Hosoya, Hiroshi; Tanimoto, Yoshifumi

    2006-05-01

    Effect of horizontal strong static magnetic field on swimming behaviour of Paramecium caudatum was studied by using a superconducting magnet. Around a centre of a round vessel, random swimming at 0 T and aligned swimming parallel to the magnetic field (MF) of 8 T were observed. Near a wall of the vessel, however, swimming round and round along the wall at 0 T and aligned swimming of turning at right angles upon collision with the wall, which was remarkable around 1-4 T, were detected. It was experimentally revealed that the former MF-induced parallel swimming at the vessel centre was caused physicochemically by the parallel magnetic orientation of the cell itself. From magnetic field dependence of the extent of the orientation, the magnetic susceptibility anisotropy (χ ∥-χ ⊥) was first obtained to be 3.4× 10-23 emu cell-1 at 298 K for Paramecium caudatum. The orientation of the cell was considered to result from the magnetic orientation of the cell membrane. On the other hand, although mechanisms of the latter swimming near the vessel wall regardless of the absence and presence of the magnetic field are unclear at present, these experimental results indicate that whether the cell exists near the wall alters the magnetic field effect on the swimming in the horizontal magnetic field.

  9. A blood-oxygenation-dependent increase in blood viscosity due to a static magnetic field

    International Nuclear Information System (INIS)

    Yamamoto, Toru; Nagayama, Yuki; Tamura, Mamoru

    2004-01-01

    As the magnetic field of widely used MR scanners is one of the strongest magnetic fields to which people are exposed, the biological influence of the static magnetic field of MR scanners is of great concern. One magnetic interaction in biological subjects is the magnetic torque on the magnetic moment induced by biomagnetic substances. The red blood cell is a major biomagnetic substance, and the blood flow may be influenced by the magnetic field. However, the underlying mechanisms have been poorly understood. To examine the mechanisms of the magnetic influence on blood viscosity, we measured the time for blood to fall through a glass capillary inside and outside a 1.5 T MR scanner. Our in vitro results showed that the blood viscosity significantly increased in a 1.5 T MR scanner, and also clarified the mechanism of the interaction between red blood cells and the external magnetic field. Notably, the blood viscosity increased depending on blood oxygenation and the shear rate of the blood flow. Thus, our findings suggest that even a 1.5 T magnetic field may modulate blood flow

  10. Creutzfeldt-Jakob Disease with a prion protein gene codon 180 mutation presenting asymmetric cortical high-intensity on magnetic resonance imaging.

    Science.gov (United States)

    Amano, Yuko; Kimura, Noriyuki; Hanaoka, Takuya; Aso, Yasuhiro; Hirano, Teruyuki; Murai, Hiroyuki; Satoh, Katsuya; Matsubara, Etsuro

    2015-01-01

    Here we report a genetically confirmed case of Creutzfeldt-Jakob disease with a prion protein gene codon 180 mutation presenting atypical magnetic resonance imaging findings. The present case exhibited an acute onset and lateralized neurologic signs, and progressive cognitive impairment. No myoclonus or periodic synchronous discharges on electroencephalography were observed. Diffusion-weighted images revealed areas of high signal intensity in the right frontal and temporal cortices at onset that extended to the whole cortex and basal ganglia of the right cerebral hemisphere at 3 months. Although the cerebrospinal fluid (CSF) was initially negative for neuron specific enolase, tau protein, 14-3-3 protein, and abnormal prion protein, the CSF was positive for these brain-derived proteins at 3 months after onset.

  11. Static magnetism and thermal switching in randomly oriented L10 FePt thin films

    Science.gov (United States)

    Lisfi, A.; Pokharel, S.; Alqarni, A.; Akioya, O.; Morgan, W.; Wuttig, M.

    2018-05-01

    Static magnetism and thermally activated magnetic relaxation were investigated in granular FePt films (20 nm-200 nm thick) with random magnetic anisotropy through hysteresis loop, torque curve and magnetization time dependence measurements. While the magnetism of thicker film (200 nm thick) is dominated by a single switching of the ordered L10 phase, thinner film (20 nm) displays a double switching, which is indicative of the presence of the disordered cubic phase. The pronounced behavior of double switching in thinner film suggests that the film grain boundary is composed of soft cubic magnetic phase. The magnetic relaxation study reveals that magnetic viscosity S of the films is strongly dependent on the external applied field and exhibits a maximum value (12 kAm) around the switching field and a vanishing behavior at low (1 kOe) and large (12 kOe) fields. The activation volume of the thermal switching was found to be much smaller than the physical volume of the granular structure due to the incoherent rotation mode of the magnetization reversal mechanism, which is established to be domain wall nucleation.

  12. Static properties of small Josephson tunnel junctions in a transverse magnetic field

    DEFF Research Database (Denmark)

    Monaco, R.; Aarøe, Morten; Mygind, Jesper

    2008-01-01

    The magnetic field distribution in the barrier of small planar Josephson tunnel junctions is numerically simulated in the case when an external magnetic field is applied perpendicular to the barrier plane. The simulations allow for heuristic analytical solutions for the Josephson static phase...... profile from which the dependence of the maximum Josephson current on the applied field amplitude is derived. The most common geometrical configurations are considered and, when possible, the theoretical findings are compared with the experimental data. ©2008 American Institute of Physics...

  13. Elliptic annular Josephson tunnel junctions in an external magnetic field: the statics

    DEFF Research Database (Denmark)

    Monaco, Roberto; Granata, Carmine; Vettoliere, Antonio

    2015-01-01

    We have investigated the static properties of one-dimensional planar Josephson tunnel junctions (JTJs) in the most general case of elliptic annuli. We have analyzed the dependence of the critical current in the presence of an external magnetic field applied either in the junction plane...... symmetric electrodes a transverse magnetic field is equivalent to an in-plane field applied in the direction of the current flow. Varying the ellipse eccentricity we reproduce all known results for linear and ring-shaped JTJs. Experimental data on high-quality Nb/Al-AlOx/Nb elliptic annular junctions...

  14. Experimentally attainable example of chaotic tunneling: The hydrogen atom in parallel static electric and magnetic fields

    International Nuclear Information System (INIS)

    Delande, Dominique; Zakrzewski, Jakub

    2003-01-01

    Statistics of tunneling rates in the presence of chaotic classical dynamics is discussed on a realistic example: a hydrogen atom placed in parallel, uniform, static electric, and magnetic fields, where tunneling is followed by ionization along the fields direction. Depending on the magnetic quantum number, one may observe either a standard Porter-Thomas distribution of tunneling rates or, for strong scarring by a periodic orbit parallel to the external fields, strong deviations from it. For the latter case, a simple model based on random matrix theory gives the correct distribution

  15. Diagnosis of high-intensity pulsed heavy ion beam generated by a novel magnetically insulated diode with gas puff plasma gun.

    Science.gov (United States)

    Ito, H; Miyake, H; Masugata, K

    2008-10-01

    Intense pulsed heavy ion beam is expected to be applied to materials processing including surface modification and ion implantation. For those applications, it is very important to generate high-purity ion beams with various ion species. For this purpose, we have developed a new type of a magnetically insulated ion diode with an active ion source of a gas puff plasma gun. When the ion diode was operated at a diode voltage of about 190 kV, a diode current of about 15 kA, and a pulse duration of about 100 ns, the ion beam with an ion current density of 54 A/cm(2) was obtained at 50 mm downstream from the anode. By evaluating the ion species and the energy spectrum of the ion beam via a Thomson parabola spectrometer, it was confirmed that the ion beam consists of nitrogen ions (N(+) and N(2+)) of energy of 100-400 keV and the proton impurities of energy of 90-200 keV. The purity of the beam was evaluated to be 94%. The high-purity pulsed nitrogen ion beam was successfully obtained by the developed ion diode system.

  16. Occupational exposure measurements of static and pulsed gradient magnetic fields in the vicinity of MRI scanners

    Energy Technology Data Exchange (ETDEWEB)

    Kaennaelae, Sami; Toivo, Tim; Jokela, Kari [STUK-Radiation and Nuclear Safety Authority, PO Box 14, 00881 Helsinki (Finland); Alanko, Tommi [Finnish Institute of Occupational Health, New Technologies and Risks, Topeliuksenkatu 41a A, 00250 Helsinki (Finland)], E-mail: sami.kannala@stuk.fi

    2009-04-07

    Recent advances in magnetic resonance imaging (MRI) have increased occupational exposure to magnetic fields. In this study, we examined the assessment of occupational exposure to gradient magnetic fields and time-varying magnetic fields generated by motion in non-homogeneous static magnetic fields of MRI scanners. These magnetic field components can be measured simultaneously with an induction coil setup that detects the time rate of change of magnetic flux density (dB/dt). The setup developed was used to measure the field components around two MRI units (1 T open and 3 T conventional). The measured values can be compared with dB/dt reference levels derived from magnetic flux density reference levels given by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The measured motion-induced dB/dt values were above the dB/dt reference levels for both MRI units. The measured values for the gradient fields (echo planar imaging (EPI) and fast field echo (FFE) sequences) also exceeded the dB/dt reference levels in positions where the medical staff may have access during interventional procedures. The highest motion-induced dB/dt values were 0.7 T s{sup -1} for the 1 T scanner and 3 T s{sup -1} for the 3 T scanner when only the static field was present. Even higher values (6.5 T s{sup -1}) were measured for simultaneous exposure to motion-induced and gradient fields in the vicinity of the 3 T scanner.

  17. Cylindrical magnetization model for glass-coated microwires with circular anisotropy: Statics

    International Nuclear Information System (INIS)

    Torrejon, J.; Thiaville, A.; Adenot-Engelvin, A.L.; Vazquez, M.; Acher, O.

    2011-01-01

    The static magnetization profile of glass-coated microwires with effective circular anisotropy is investigated using micromagnetics. In this family of microwires, the ferromagnetic nucleus with an amorphous character presents a magnetic structure composed of an inner region with axial domains and an outer region with circular domains, due to magnetoelastic anisotropy. A one-dimensional micromagnetic model is developed, taking into account both the exchange and magnetoelastic anisotropy energies, and solved quasi analytically. The total energy, magnetization profiles and magnetization curves are investigated as a function of radius and anisotropy constant of the nucleus. This work represents a fundamental study of the magnetization process in these amorphous microwires and provides guidelines for the production of microwires with tailored magnetic properties. En passant, the nucleation problem in an infinite cylinder, introduced by W.F. Brown, is revisited. - Research highlights: → Magnetic microwires with circular anisotropy are studied by micromagnetic model. → The ratio R/Δ is a fundamental quantity to determine the magnetic structure. → Reduction of diameter and anisotropy favours the growth of axial core.

  18. Design and Demonstration of a Test-Rig for Static Performance-Studies of Permanent Magnet Couplings

    DEFF Research Database (Denmark)

    Högberg, Stig; Jensen, Bogi Bech; Bendixen, Flemming Buus

    2013-01-01

    The design and construction of an easy-to-use test-rig for permanent magnet couplings is presented. Static torque of permanent magnet couplings as a function of angular displacement is measured of permanent magnet couplings through an semi-automated test system. The test-rig is capable of measuring...

  19. Landau Quasi-energy Spectrum Destruction for an Electron in Both a Static Magnetic Field and a Resonant Electromagnetic Wave

    International Nuclear Information System (INIS)

    Skoblin, A.A.

    1994-01-01

    Free nonrelativistic electrons in both a static magnetic field and an electromagnetic wave are considered. A plane-polarized wave propagates along a magnetic field, its frequency is close to the electron rotation frequency in a magnetic field. Electron spin is taken into account. An electron quasi energy spectrum and steady states (quasi energy states) are constructed. 6 refs

  20. High-intensity laser physics

    International Nuclear Information System (INIS)

    Mohideen, U.

    1993-01-01

    This thesis is a study of the effect of high intensity lasers on atoms, free electrons and the generation of X-rays from solid density plasmas. The laser produced 50 milli Joule 180 femto sec pulses at 5 Hz. This translates to a maximum intensity of 5 x 10 18 W/cm 2 . At such high fields the AC stark shifts of atoms placed at the focus is much greater than the ionization energy. The characteristics of multiphoton ionization of atoms in intense laser fields was studied by angle resolved photoelectron spectroscopy. Free electrons placed in high intensity laser fields lead to harmonic generation. This phenomenon of Nonlinear Compton Scattering was theoretically investigated. Also, when these high intensity pulses are focused on solids a hot plasma is created. This plasma is a bright source of a short X-ray pulse. The pulse-width of X-rays from these solid density plasmas was measured by time-resolved X-ray spectroscopy

  1. Study of static and dynamic magnetic properties of Fe nanoparticles composited with activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Satyendra Prakash, E-mail: sppal85@gmail.com [School of Physical Sciences, Jawaharlal Nehru University, New Delhi-110067 (India); Department of Physical Sciences, Indian Institute of Science Education and Research, Mohali, Knowledge city, Sector81, SAS Nagar, Manauli-140306, Punjab (India); Kaur, Guratinder [Department of Physical Sciences, Indian Institute of Science Education and Research, Mohali, Knowledge city, Sector81, SAS Nagar, Manauli-140306, Punjab (India); Sen, P. [School of Physical Sciences, Jawaharlal Nehru University, New Delhi-110067 (India)

    2016-05-23

    Nanocomposite of Fe nanoparticles with activated carbon has been synthesized to alter the magnetic spin-spin interaction and hence study the dilution effect on the static and dynamic magnetic properties of the Fe nanoparticle system. Transmission electron microscopic (TEM) image shows the spherical Fe nanoparticles dispersed in carbon matrix with 13.8 nm particle size. Temperature dependent magnetization measurement does not show any blocking temperature at all, right up to the room temperature. Magnetic hysteresis curve, taken at 300 K, shows small value of the coercivity and this small hysteresis indicates the presence of an energy barrier and inherent magnetization dynamics. Langevin function fitting of the hysteresis curve gives almost similar value of particle size as obtained from TEM analysis. Magnetic relaxation data, taken at a temperature of 100 K, were fitted with a combination of two exponentially decaying function. This diluted form of nanoparticle system, which has particles size in the superparamagnetic limit, behaves like a dilute ensemble of superspins with large value of the magnetic anisotropic barrier.

  2. Photodetachment of H- by a short laser pulse in crossed static electric and magnetic fields

    International Nuclear Information System (INIS)

    Peng Liangyou; Wang Qiaoling; Starace, Anthony F.

    2006-01-01

    We present a detailed quantum mechanical treatment of the photodetachment of H - by a short laser pulse in the presence of crossed static electric and magnetic fields. An exact analytic formula is presented for the final state electron wave function (describing an electron in both static electric and magnetic fields and a short laser pulse of arbitrary intensity). In the limit of a weak laser pulse, final state electron wave packet motion is examined and related to the closed classical electron orbits in crossed static fields predicted by Peters and Delos [Phys. Rev. A 47, 3020 (1993)]. Owing to these closed orbit trajectories, we show that the detachment probability can be modulated, depending on the time delay between two laser pulses and their relative phase, thereby providing a means to partially control the photodetachment process. In the limit of a long, weak pulse (i.e., a monochromatic radiation field) our results reduce to those of others; however, for this case we analyze the photodetachment cross section numerically over a much larger range of electron kinetic energy (i.e., up to 500 cm -1 ) than in previous studies and relate the detailed structures both analytically and numerically to the above-mentioned, closed classical periodic orbits

  3. Pelvic Static Magnetic Stimulation to Control Urinary Incontinence in Older Women: A Randomized Controlled Trial

    Science.gov (United States)

    Wallis, Marianne C.; Davies, Elizabeth A.; Thalib, Lukman; Griffiths, Susan

    2012-01-01

    Objectives To determine the efficacy of non-invasive static magnetic stimulation (SMS) of the pelvic floor compared to placebo in the treatment of women aged 60 years and over with urinary incontinence for 6 months or more. Subjects and Methods A single-blinded randomized, placebo-controlled, parallel-group trial. Subjects were excluded if they had an implanted electronic device, had experienced a symptomatic urinary tract infection, or had commenced pharmacotherapy for the same in the previous 4 weeks, or if they were booked for pelvic floor or gynecological surgery within the next 3 months. Once written consent was obtained, subjects were randomly assigned to the active SMS group (n=50) or the placebo group (n=51). Treatment was an undergarment incorporating 15 static magnets of 800–1200 Gauss anterior, posterior, and inferior to the pelvis for at least 12 hours a day for 3 months. Placebo was the same protocol with inert metal disks replacing the magnets. Primary outcome measure was cessation of incontinence as measured by a 24-hour pad test. Secondary outcomes were frequency and severity of symptoms as measured by the Bristol Female Lower Urinary Tract Symptoms questionnaire (BFLUTS-SF), the Incontinence Severity Index, a Bothersomeness Visual Analog scale, and a 24-hour bladder diary. Data were collected at baseline and 12 weeks later. Results There were no statistically significant differences between groups in any of the outcome measures from baseline to 12 weeks. Initial evidence of subjective improvement in the treatment group compared to the placebo group was not sustained with sensitivity analysis. Conclusion This study found no evidence that static magnets cure or decrease the symptoms of urinary incontinence. Additional work into the basic physics of the product and garment design is recommended prior to further clinical trials research. PMID:21817123

  4. Recovery of Small-Sized Blood Vessels in Ischemic Bone under Static Magnetic Field

    Directory of Open Access Journals (Sweden)

    Shenzhi Xu

    2007-01-01

    Full Text Available Effects of static magnetic field (SMF on the vascularization in bone were evaluated using an ischemic bone model, where rat femoral artery was ligated. Magnetized and unmagnetized samarium–cobalt rods were implanted transcortically into the middle diaphysis of the ischemic femurs. Collateral circulation was evaluated by injection of microspheres into the abdominal aorta at the third week after ligation. It was found that the bone implanted with a magnetized rod showed a larger amount of trapped microspheres than that with an unmagnetized rod at the proximal and the distal region (P < 0.05 proximal region. There were no significant differences at the middle and the distal region. This tendency was similar to that of the bone mineral density in the SMF-exposed ischemic bone.

  5. Fast dose planning Monte Carlo simulations in inhomogeneous phantoms submerged in uniform, static magnetic fields

    International Nuclear Information System (INIS)

    Yanez, R.; Dempsey, J. F.

    2007-01-01

    We present studies in support of the development of a magnetic resonance imaging (MRI) guided intensity modulated radiation therapy (IMRT) device for the treatment of cancer patients. Fast and accurate computation of the absorbed ionizing radiation dose delivered in the presence of the MRI magnetic field are required for clinical implementation. The fast Monte Carlo simulation code DPM, optimized for radiotherapy treatment planning, is modified to simulate absorbed doses in uniform, static magnetic fields, and benchmarked against PENELOPE. Simulations of dose deposition in inhomogeneous phantoms in which a low density material is sandwiched in water shows that a lower MRI field strength (0.3 T) is to prefer in order to avoid dose build-up near material boundaries. (authors)

  6. TPC track distortions: correction maps for magnetic and static electric inhomogeneities

    CERN Document Server

    Dydak, F; Nefedov, Y

    2003-01-01

    Inhomogeneities of the magnetic and electric fields in the active TPC volume lead to displacements of cluster coordinates, and therefore to track distortions. In case of good data taking conditions, the largest effects are expected from the inhomogeneity of the solenoidal magnetic field, and from a distortion of the electric field arising from a high voltage misalignment between the outer and inner field cages. Both effects are stable over the entire HARP data taking. The displacements are large compared to the azimuthal coordinate resolution but can be corrected with sufficient precision, except at small TPC radius. The high voltage misalignment between the outer and inner field cages is identified as the likely primary cause of sagitta distortions of TPC tracks. The position and the length of the target plays an important role. Based on a detailed modelling of the magnetic and static electric field inhomogeneities, precise correction maps for both effects have been calculated. Predictions from the correctio...

  7. Magnetic anisotropy study of UGe2in a static high magnetic field

    International Nuclear Information System (INIS)

    Sakon, T; Saito, S; Koyama, K; Awaji, S; Sato, I; Nojima, T; Watanabe, K; Motokawa, M; Sato, N K

    2006-01-01

    UGe 2 has orthorhombic C mmm crystalline symmetry and shows ferromagnetic Heavy-Fermion (HF) Superconductor, which provides superconductivity under pressure in the range from 1.0 GPa to 1.5 GPa. Magnetic field dependence of magnetization shows strong magnetic anisotropy. When a magnetic field is applied parallel to easy axis (a-axis), magnetization presents ferromagnetic behavior. At 4.2 K, which is much lower than the Curie temperature T c = 54 K. Spontaneous magnetization is 1.4 μ B /U, and the magnetization gradually increase with increasing field. On the contrary, when a field is applied parallel to hard axis (b-axis or c-axis), magnetization increases linearly with increasing magnetic field. As for H//b-axis, magnetization is 0.23 μ B /U even at 27 T. Magnetocrystalline anisotropy constant is obtained as 230 [T μ B ] 3.4[kJ/kg] at 4.2 K. This value is comparable with rare-earth magnet Nd 2 Fe 17 , which is typical strongly correlated ferromagnet

  8. Field Distribution of Transcranial Static Magnetic Stimulation in Realistic Human Head Model.

    Science.gov (United States)

    Tharayil, Joseph J; Goetz, Stefan M; Bernabei, John M; Peterchev, Angel V

    2017-10-10

    The objective of this work was to characterize the magnetic field (B-field) that arises in a human brain model from the application of transcranial static magnetic field stimulation (tSMS). The spatial distribution of the B-field magnitude and gradient of a cylindrical, 5.08 cm × 2.54 cm NdFeB magnet were simulated in air and in a human head model using the finite element method and calibrated with measurements in air. The B-field was simulated for magnet placements over prefrontal, motor, sensory, and visual cortex targets. The impact of magnetic susceptibility of head tissues on the B-field was quantified. Peak B-field magnitude and gradient respectively ranged from 179-245 mT and from 13.3-19.0 T/m across the cortical targets. B-field magnitude, focality, and gradient decreased with magnet-cortex distance. The variation in B-field strength and gradient across the anatomical targets largely arose from the magnet-cortex distance. Head magnetic susceptibilities had negligible impact on the B-field characteristics. The half-maximum focality of the tSMS B-field ranged from 7-12 cm 3 . This is the first presentation and characterization of the three-dimensional (3D) spatial distribution of the B-field generated in a human brain model by tSMS. These data can provide quantitative dosing guidance for tSMS applications across various cortical targets and subjects. The finding that the B-field gradient is high near the magnet edges should be considered in studies where neural tissue is placed close to the magnet. The observation that susceptibility has negligible effects confirms assumptions in the literature. © 2017 International Neuromodulation Society.

  9. Possible promotion of neuronal differentiation in fetal rat brain neural progenitor cells after sustained exposure to static magnetism.

    Science.gov (United States)

    Nakamichi, Noritaka; Ishioka, Yukichi; Hirai, Takao; Ozawa, Shusuke; Tachibana, Masaki; Nakamura, Nobuhiro; Takarada, Takeshi; Yoneda, Yukio

    2009-08-15

    We have previously shown significant potentiation of Ca(2+) influx mediated by N-methyl-D-aspartate receptors, along with decreased microtubules-associated protein-2 (MAP2) expression, in hippocampal neurons cultured under static magnetism without cell death. In this study, we investigated the effects of static magnetism on the functionality of neural progenitor cells endowed to proliferate for self-replication and differentiate into neuronal, astroglial, and oligodendroglial lineages. Neural progenitor cells were isolated from embryonic rat neocortex and hippocampus, followed by culture under static magnetism at 100 mT and subsequent determination of the number of cells immunoreactive for a marker protein of particular progeny lineages. Static magnetism not only significantly decreased proliferation of neural progenitor cells without affecting cell viability, but also promoted differentiation into cells immunoreactive for MAP2 with a concomitant decrease in that for an astroglial marker, irrespective of the presence of differentiation inducers. In neural progenitors cultured under static magnetism, a significant increase was seen in mRNA expression of several activator-type proneural genes, such as Mash1, Math1, and Math3, together with decreased mRNA expression of the repressor type Hes5. These results suggest that sustained static magnetism could suppress proliferation for self-renewal and facilitate differentiation into neurons through promoted expression of activator-type proneural genes by progenitor cells in fetal rat brain.

  10. MRI-related static magnetic stray fields and postural body sway: a double-blind randomized crossover study.

    Science.gov (United States)

    van Nierop, Lotte E; Slottje, Pauline; Kingma, Herman; Kromhout, Hans

    2013-07-01

    We assessed postural body sway performance after exposure to movement induced time-varying magnetic fields in the static magnetic stray field in front of a 7 Tesla (T) magnetic resonance imaging scanner. Using a double blind randomized crossover design, 30 healthy volunteers performed two balance tasks (i.e., standing with eyes closed and feet in parallel and then in tandem position) after standardized head movements in a sham, low exposure (on average 0.24 T static magnetic stray field and 0.49 T·s(-1) time-varying magnetic field) and high exposure condition (0.37 T and 0.70 T·s(-1)). Personal exposure to static magnetic stray fields and time-varying magnetic fields was measured with a personal dosimeter. Postural body sway was expressed in sway path, area, and velocity. Mixed-effects model regression analysis showed that postural body sway in the parallel task was negatively affected (P < 0.05) by exposure on all three measures. The tandem task revealed the same trend, but did not reach statistical significance. Further studies are needed to investigate the possibility of independent or synergetic effects of static magnetic stray field and time-varying magnetic field exposure. In addition, practical safety implications of these findings, e.g., for surgeons and others working near magnetic resonance imaging scanners need to be investigated. Copyright © 2012 Wiley Periodicals, Inc.

  11. Effect of static magnetic field on the oxygen production of Scenedesmus obliquus cultivated in municipal wastewater.

    Science.gov (United States)

    Tu, Renjie; Jin, Wenbiao; Xi, Tingting; Yang, Qian; Han, Song-Fang; Abomohra, Abd El-Fatah

    2015-12-01

    Algal-bacterial symbiotic system, with biological synergism of physiological functions of both algae and bacteria, has been proposed for cultivation of microalgae in municipal wastewater for biomass production and wastewater treatment. The algal-bacterial symbiotic system can enhance dissolved oxygen production which enhances bacterial growth and catabolism of pollutants in wastewater. Therefore, the oxygen production efficiency of microalgae in algal-bacterial systems is considered as the key factor influencing the wastewater treatment efficiency. In the present study, we have proposed a novel approach which uses static magnetic field to enhance algal growth and oxygen production rate with low operational cost and non-toxic secondary pollution. The performance of oxygen production with the magnetic field was evaluated using Scenedesmus obliquus grown in municipal wastewater and was calculated based on the change in dissolved oxygen concentration. Results indicated that magnetic treatment stimulates both algal growth and oxygen production. Application of 1000 GS of magnetic field once at logarithmic growth phase for 0.5 h increased the chlorophyll-a content by 11.5% over the control after 6 days of growth. In addition, magnetization enhanced the oxygen production rate by 24.6% over the control. Results of the study confirmed that application of a proper magnetic field could reduce the energy consumption required for aeration during the degradation of organic matter in municipal wastewater in algal-bacterial symbiotic systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Influence of static magnetic fields in phototaxis and osmotic stress in Gymnodinium catenatum (Dinophyceae).

    Science.gov (United States)

    Vale, Paulo

    2017-07-01

    Phototaxis response of the toxic microalgae Gymnodinium catenatum was studied in vitro. The percentage of cells remaining at mid-depth 20 min after stirring increased with solar radio, X-ray and solar flares output. It also increased with geomagnetic activity and temperature, and was dependent on culture time. Increase in the local static magnetic field with a permanent magnet did not influence the positive phototaxis response. However, survival and growth to a provoked hypo-osmotic shock in an altered static magnetic field was dependent on culture time and geomagnetic activity at a threshold below 22 nT. The results from phototaxis and hypo-osmotic shock experiments were in line with the previous hypothesis for the existence of two separate deleterious mechanisms conditioning the natural blooms of G. catenatum: one that is dependent on solar radiation and the other that is related to geomagnetic activity. Variations in electromagnetic fields caused by tectonic activity were also capable of influencing G. catenatum phototaxis and growth response in vitro.

  13. Distribution of electron orbits having a definite angular momentum in a static magnetic field

    International Nuclear Information System (INIS)

    Olszewski, S.

    1996-01-01

    Electron orbits having a definite angular momentum in a static magnetic field are calculated with the aid of the Bohr-Sommerfeld quantization rules. The quantization gives that orbits are arranged along a straight line but the distance between the centers of two neighboring orbits decreases with increase of the absolute value of the angular momentum. With the energy correction equal to the zero-point energy of the harmonic oscillator, the distribution of orbits becomes identical to that obtained recently with the aid of a mixed semiclassical and quantum mechanical theory. 16 refs., 1 fig

  14. Finite-size effects on the static properties of a single-chain magnet

    Science.gov (United States)

    Bogani, L.; Sessoli, R.; Pini, M. G.; Rettori, A.; Novak, M. A.; Rosa, P.; Massi, M.; Fedi, M. E.; Giuntini, L.; Caneschi, A.; Gatteschi, D.

    2005-08-01

    We study the role of defects in the “single-chain magnet” CoPhOMe by inserting a controlled number of diamagnetic impurities. The samples are analyzed with unprecedented accuracy with the particle induced x-ray emission technique, and with ac and dc magnetic measurements. In an external applied field the system shows an unexpected behavior, giving rise to a double peak in the susceptibility. The static thermodynamic properties of the randomly diluted Ising chain with alternating g values are then exactly obtained via a transfer matrix approach. These results are compared to the experimental behavior of CoPhOMe, showing qualitative agreement.

  15. Improving heat generation of magnetic nanoparticles by pre-orientation of particles in a static three tesla magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Mathias M., E-mail: Mathias.Beck@tum.de [Institute for Machine Tools and Industrial Management, Technical University of Munich, Boltzmannstr. 15, 85748 Garching (Germany); Lammel, Christian [Institute for Machine Tools and Industrial Management, Technical University of Munich, Boltzmannstr. 15, 85748 Garching (Germany); Gleich, Bernhard [Institute of Medical Engineering, Technical University of Munich, Boltzmannstr. 11, 85748 Garching (Germany)

    2017-04-01

    Inductive heating of electrically insulating materials like fiberglass reinforced thermoplastics (FRTP) without susceptors is not possible. However, due to their low thermal conductivity a volumetric heat generation method is advisable to reach short heating times to melt this material for reshaping. This can be done with magnetic nanoparticles as susceptors within the thermoplastic of the FRTP using Néel relaxation. During the heating process the particle's magnetic moment rotates with the field while the particle itself is fixed within the thermoplastic. Therefore the heat dissipation of each particle depends on its orientation within the field. To achieve the maximum heat generation of the particles we pre-oriented the particles within a plastic at the best angle to the applied AC field for induction. To do this, five mass percent nanoparticles were dispersed in an epoxy resin, which was then hardened at room temperature in a static three Tesla magnetic field. After its solidification the heating behavior of the sample was compared to a reference sample, which was hardened without a field. The oriented particles showed an increased heating rate when oriented parallel to the applied AC field. The absorption rate was 3.3 times as high as the undirected reference sample. When the alternating electromagnetic field was perpendicular to the oriented particles, the specific absorption rate was similar to that of the reference sample. We compare this result with theory and with calculations from literature, and conduct a numerical simulation. - Highlights: • Magnetic nanoparticles are aligned using a static three tesla magnetic field. • Inductive heating depends on the particles pre-orientation in a solid matrix. • Alignment increases the heat generation significantly.

  16. Tolerable Beam Loss at High-Intensity Machines

    International Nuclear Information System (INIS)

    Krivosheev, Oleg E.; Mokhov, Nikolai V.

    2000-01-01

    Tolerable beam losses are estimated for high-intensity ring accelerators with proton energy of 3 to 16 GeV. Dependence on beam energy, lattice and magnet geometry is studied via full Monte Carlo MARS14 simulations in lattice elements, shielding, tunnel and surrounding dirt with realistic geometry, materials and magnetic fields

  17. Evaluation of occupational exposure to static magnetic field in a chloralkali plant

    Directory of Open Access Journals (Sweden)

    AR Coobineh

    2005-10-01

    Full Text Available Background and Aims: An observational cross sectional study was conducted to determine iflong term exposure to static magnetic fields could be related to findings of medical examinations.Method: Health data were obtained for 20 workers who spent a major portion of their workdaysin the magnetic fields produced by the direct current through large electrolytic cells. These datawere compared to those of a control group of 21 workers. Intensity of magnetic fields weremeasured in the cell room and the Time weighted Average (TWA exposure to magnetic field wascalculated for each job classification.Results: Maximum and minimum intensities in mTwere found to be 16.99 and 0.46, respectively,which were well below the permissible level. Maximum TWAexposure to magnetic field wasfound to be 47.59 mTWhich were observed. Comparing the ECG, EEG, blood Pressure and pulseratesbetween the two groups showed no statistically significant differences. Clinical findingshowed that fatigue and nervousness complain were be higher in the case group and weresignificantly different between the two groups.Conclusion: We did not see statistical significant differences between case and control groups inECG, EEG, blood pressure and pulse-rates. We have seen statistically differences in the fatigue(P<0.01 and nervousness (P<0.01 complain of these two groups. We suggest that it may benecessary to choose a value of than 60 mT (TLV-TWA, so that the complains of fatigue andnervousness will be reduce.

  18. Interaction of biological systems with static and ELF electric and magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, L.E.; Kelman, B.J.; Weigel, R.J. (eds.)

    1987-01-01

    Although background levels of atmospheric electric and geomagnetic field levels are extremely low, over the past several decades, human beings and other life forms on this planet have been subjected to a dramatically changing electromagnetic milieu. An exponential increase in exposure to electromagnetic fields has occurred, largely because of such technological advances as the growth of electrical power generation and transmission systems, the increased use of wireless communications, and the use of radar. In addition, electromagnetic field generating devices have proliferated in industrial plants, office buildings, homes, public transportation systems, and elsewhere. Although significant increases have occurred in electromagnetic field strenghths spanning all frequency ranges, this symposium addresses only the impact of these fields at static and extremely low frequencies (ELF), primarily 50 and 60 Hz. This volume contains the proceedings of the symposium entitled /open quotes/Interaction of biological systems with static and ELF electric and magnetic fields/close quotes/. The purpose of the symposium was to provide a forum for discussions of all aspects of research on the interaction of static and ELF electromagnetic fields with biological systems. These systems include simple biophysical models, cell and organ preparations, whole animals, and man. Dosimetry, exposure system design, and artifacts in ELF bioeffects research were also addressed, along with current investigations that examine fundamental mechanisms of interactions between the fields and biological processes. Papers are indexed separately.

  19. Biological effects of electromagnetic fields and recently updated safety guidelines for strong static magnetic fields

    International Nuclear Information System (INIS)

    Yamaguchi-Sekino, Sachiko; Sekino, Masaki; Ueno, Shoogo

    2011-01-01

    Humans are exposed daily to artificial and naturally occurring magnetic fields that originate from many different sources. We review recent studies that examine the biological effects of and medical applications involving electromagnetic fields, review the properties of static and pulsed electromagnetic fields that affect biological systems, describe the use of a pulsed electromagnetic field in combination with an anticancer agent as an example of a medical application that incorporates an electromagnetic field, and discuss the recently updated safety guidelines for static electromagnetic fields. The most notable modifications to the 2009 International Commission on Non-Ionizing Radiation Protection guidelines are the increased exposure limits, especially for those who work with or near electromagnetic fields (occupational exposure limits). The recommended increases in exposure were determined using recent scientific evidence obtained from animal and human studies. Several studies since the 1994 publication of the guidelines have examined the effects on humans after exposure to high static electromagnetic fields (up to 9.4 tesla), but additional research is needed to ascertain further the safety of strong electromagnetic fields. (author)

  20. Cognition and sensation in very high static magnetic fields: a randomized case-crossover study with different field strengths.

    Science.gov (United States)

    Heinrich, Angela; Szostek, Anne; Meyer, Patric; Nees, Frauke; Rauschenberg, Jaane; Gröbner, Jens; Gilles, Maria; Paslakis, Georgios; Deuschle, Michael; Semmler, Wolfhard; Flor, Herta

    2013-01-01

    To establish the extent to which representative cognitive functions in subjects undergoing magnetic resonance (MR) imaging are acutely impaired by static magnetic fields of varying field strengths. This study was approved by the local ethics committee, and informed consent was obtained from all subjects. In this single-blind case-crossover study, 41 healthy subjects underwent an extensive neuropsychologic examination while in MR units of differing field strengths (1.5, 3.0, and 7.0 T), including a mock imager with no magnetic field as a control condition. Subjects were blinded to field strength. Tests were performed while subjects were lying still in the MR unit and while the examination table was moved. The tests covered a representative set of cognitive functions, such as memory, eye-hand coordination, attention, reaction time, and visual discrimination. Subjective sensory perceptions were also assessed. Effects were analyzed with a repeated-measures analysis of variance; the within-subject factors were field strength (0, 1.5, 3.0, and 7.0 T) and state (static, dynamic). Static magnetic fields were not found to have a significant effect on cognitive function at any field strength. However, sensory perceptions did vary according to field strength. Dizziness, nystagmus, phosphenes, and head ringing were related to the strength of the static magnetic field. Static magnetic fields as high as 7.0 T did not have a significant effect on cognition. RSNA, 2012

  1. Low-frequency flux noise in YBCO dc SQUIDs cooled in static magnetic fields

    International Nuclear Information System (INIS)

    Sager, M.P.; Bindslev Hansen, J.; Petersen, P.R.E.; Holst, T.; Shen, Y.Q.

    1999-01-01

    The low-frequency flux noise in bicrystal and step-edge YBa 2 Cu 3 O x dc SQUIDs has been investigated. The width, w, of the superconducting strips forming the SQUID frame was varied from 4 to 42 μm. The SQUIDs were cooled in static magnetic fields up to 150 μT. Two types of low-frequency noise dominated, namely 1/f-like noise and random telegraph noise giving a Lorentzian frequency spectrum. The 1/f noise performance of the w = 4, 6 and 7 μm SQUIDs was almost identical, while the SQUIDs with w = 22 and 42 μm showed an order of magnitude higher noise level. Our analysis of the data suggests an exponential increase of the 1/f noise versus the cooling field, exhibiting a characteristic magnetic field around 40 μT. (author)

  2. Static magnetic field changes the activity of venom phospholipase of Vipera Lebetina snakes

    International Nuclear Information System (INIS)

    Garibova, L.S.; Avetisyan, T.O.; Ajrapetyan, S.N.

    2000-01-01

    The effect of the static magnetic field (SMF) on the phospholipid activity of the class-A snake venom is studied. The Vipera Lebetina snake venom was subjected during 10 days to 30 minute impact of the CMF daily. It is established that increase in the phospholipase A 1 and A 2 approximately by 21 and 32 % correspondingly and in the phosphodiesterase C - by 33 % was observed. The decrease in the total protein level of the snake venom by 31.6 ± 2.2 % was noted thereby. It may be assumed that the described phospholipase and phosphoesterase changes may lead to essential shifts in the total metabolic activity of cells and organism as a whole. The activity index of these ferments may serve as an indicator of changes in the environmental magnetic field [ru

  3. Studies on the influence of static magnetic fields on prenatal development of mice

    Energy Technology Data Exchange (ETDEWEB)

    Konermann, G.; Moenig, H.

    1986-10-01

    Developmental effects were studied in pregnant albino-mice after exposures to a static homogeneous magnetic field (1T) on days 7, 10 or 13 post conception. These days correspond approximately to the 16th, 28th or 42nd day p.c. in human development and represent stages of increased sensitivity. Intrauterine effects (after exposures on days 7 or 10 p.c.) were evaluated included lethality, external malformations, disoders in the fetal skeleton and fetal weights. The evaluation of postnatal effects (after exposure on day 13 p.c.) included body-weight, brain-weight, diameter of neocortex and commissures and the alignment of cortical neurons up to day 46 p.c. According to all these criteria, no developmental effects were observed after the exposures to the magnetic field. Transient effects, either being compensatable or biologically without relevance, cannot be excluded.

  4. Mutagenicity and co-mutagenicity of static magnetic field in SOD-deficient Escherichia coli

    International Nuclear Information System (INIS)

    Yoshie, Sachiko; Ikehata, Masateru; Hayakawa, Toshio; Hirota, Noriyuki; Takemura, Taro; Minowa, Takashi; Hanagata, Nobutaka

    2008-01-01

    The effects of strong static magnetic fields (SMFs) on mutagenesis related to reactive oxygen species were investigated. To estimate mutagenicity of SMFs, superoxide dismutase (SOD)-deficient Escherichia coli QC774 and its parental strain GC4468 were employed. Tester strains were exposed to 5, 10 and 13 T SMFs for 24 hr at 37 C degrees in LB medium. After exposure, mutation frequency on thymine synthesis genes was determined for evaluation of mutagenicity of SMFs exposure. In the result, no statistically significant difference in mutation frequency on thymine synthesis genes was observed between SMF-exposed cells and unexposed cells in all of magnetic flux densities. Furthermore, SMFs up to 13 T did not affect mutagenicity of plumbagine under its presence of 25 μM, respectively. It suggests that SMF did not have either mutagenicity or co-mutagenicity in SOD-deficient and its parental E. coli strains under the condition in this study. (author)

  5. Cerebellar transcranial static magnetic field stimulation transiently reduces cerebellar brain inhibition.

    Science.gov (United States)

    Matsugi, Akiyoshi; Okada, Y

    The aim of this study was to investigate whether transcranial static magnetic field stimulation (tSMS) delivered using a compact cylindrical NdFeB magnet over the cerebellum modulates the excitability of the cerebellum and contralateral primary motor cortex, as measured using cerebellar brain inhibition (CBI), motor evoked potentials (MEPs), and resting motor threshold (rMT). These parameters were measured before tSMS or sham stimulation and immediately, 5 minutes and 10 minutes after stimulation. There were no significant changes in CBI, MEPs or rMT over time in the sham stimulation condition, and no changes in MEPs or rMT in the tSMS condition. However, CBI was significantly decreased immediately after tSMS as compared to that before and 5 minutes after tSMS. Our results suggest that tSMS delivered to the cerebellar hemisphere transiently reduces cerebellar inhibitory output but does not affect the excitability of the contralateral motor cortex.

  6. Strong Static Magnetic Fields Increase the Gel Signal in Partially Hydrated DPPC/DMPC Membranes.

    Science.gov (United States)

    Tang, Jennifer; Alsop, Richard J; Schmalzl, Karin; Epand, Richard M; Rheinstädter, Maikel C

    2015-09-29

    NIt was recently reported that static magnetic fields increase lipid order in the hydrophobic membrane core of dehydrated native plant plasma membranes [Poinapen, Soft Matter 9:6804-6813, 2013]. As plasma membranes are multicomponent, highly complex structures, in order to elucidate the origin of this effect, we prepared model membranes consisting of a lipid species with low and high melting temperature. By controlling the temperature, bilayers coexisting of small gel and fluid domains were prepared as a basic model for the plasma membrane core. We studied molecular order in mixed lipid membranes made of dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) using neutron diffraction in the presence of strong static magnetic fields up to 3.5 T. The contribution of the hydrophobic membrane core was highlighted through deuterium labeling the lipid acyl chains. There was no observable effect on lipid organization in fluid or gel domains at high hydration of the membranes. However, lipid order was found to be enhanced at a reduced relative humidity of 43%: a magnetic field of 3.5 T led to an increase of the gel signal in the diffraction patterns of 5%. While all biological materials have weak diamagnetic properties, the corresponding energy is too small to compete against thermal disorder or viscous effects in the case of lipid molecules. We tentatively propose that the interaction between the fatty acid chains' electric moment and the external magnetic field is driving the lipid tails in the hydrophobic membrane core into a better ordered state.

  7. Strong Static Magnetic Fields Increase the Gel Signal in Partially Hydrated DPPC/DMPC Membranes

    Directory of Open Access Journals (Sweden)

    Jennifer Tang

    2015-09-01

    Full Text Available NIt was recently reported that static magnetic fields increase lipid order in the hydrophobic membrane core of dehydrated native plant plasma membranes [Poinapen, Soft Matter 9:6804-6813, 2013]. As plasma membranes are multicomponent, highly complex structures, in order to elucidate the origin of this effect, we prepared model membranes consisting of a lipid species with low and high melting temperature. By controlling the temperature, bilayers coexisting of small gel and fluid domains were prepared as a basic model for the plasma membrane core. We studied molecular order in mixed lipid membranes made of dimyristoyl-sn-glycero-3-phosphocholine (DMPC and dipalmitoyl-sn-glycero-3-phosphocholine (DPPC using neutron diffraction in the presence of strong static magnetic fields up to 3.5 T. The contribution of the hydrophobic membrane core was highlighted through deuterium labeling the lipid acyl chains. There was no observable effect on lipid organization in fluid or gel domains at high hydration of the membranes. However, lipid order was found to be enhanced at a reduced relative humidity of 43%: a magnetic field of 3.5 T led to an increase of the gel signal in the diffraction patterns of 5%. While all biological materials have weak diamagnetic properties, the corresponding energy is too small to compete against thermal disorder or viscous effects in the case of lipid molecules. We tentatively propose that the interaction between the fatty acid chains’ electric moment and the external magnetic field is driving the lipid tails in the hydrophobic membrane core into a better ordered state.

  8. Static magnetic field effects on proteases with fibrinolytic activity produced by Mucor subtilissimus.

    Science.gov (United States)

    Albuquerque, Wendell; Nascimento, Thiago; Brandão-Costa, Romero; Fernandes, Thiago; Porto, Ana

    2017-02-01

    The influence of a static magnetic field (SMF) on crude enzyme extracts with proteolytic activity is described and discussed. Proteolytic enzymes, which hydrolyze peptide bonds, and fibrinolytic enzymes, which dissolve fibrin clots, have industrial relevance, and applicability dependent on improvements of productivity and activity. We investigated whether a moderate SMF affects proteolysis in different in vitro tests: general proteolysis of azocasein substrate, and static and dynamic fibrinolytic processes (to compare fibrin gel configuration under exposure). Crude enzyme extracts, obtained from solid state fermentation of Mucor subtilissimus UCP (Universidade Católica de Pernambuco, Recife, Brazil) 1262, were used to carry out assays under slightly heterogeneous fields: a varied vertical SMF (for tests in Eppendorf tubes, from 0.100 to 0.170 T) and a varied horizontal SMF (for tests in Petri dishes, from 0.01 to 0.122 T), generated by two permanent magnets (NdFeB alloy). Results showed significant differences (P < 0.05) in static fibrinolysis assays after 24 h of exposure. The mean diameter of halos of fibrin degradation in the treated group increased by 21% compared to the control group; and the pixel number count of fibrin consumption (in a computational analysis of the area of each halo) enhanced by 30% with exposure. However, in dynamic fibrinolysis assays, no effects of SMF were observed. These results suggest a response of fibrin monomers to the SMF as a possible cause of the observed effects. Bioelectromagnetics. 38:109-120, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Magnetic nanoparticles stimulation to enhance liquid-liquid two-phase mass transfer under static and rotating magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Azimi, Neda; Rahimi, Masoud, E-mail: masoudrahimi@yahoo.com

    2017-01-15

    Rotating magnetic field (RMF) was applied on a micromixer to break the laminar flow and induce chaotic flow to enhance mass transfer between two-immiscible organic and aqueous phases. The results of RMF were compared to those of static magnetic field (SMF). For this purpose, experiments were carried out in a T-micromixer at equal volumetric flow rates of organic and aqueous phases. Fe{sub 3}O{sub 4} nanoparticles were synthesized by co-precipitation technique and they were dissolved in organic phase. Results obtained from RMF and SMF were compared in terms of overall volumetric mass transfer coefficient (K{sub L}a) and extraction efficiency (E) at various Reynolds numbers. Generally, RMF showed higher effect in mass transfer characteristics enhancement compared with SMF. The influence of rotational speeds of magnets (ω) in RMF was investigated, and measurable enhancements of K{sub L}a and E were observed. In RMF, the effect of magnetic field induction (B) was investigated. The results reveal that at constant concentration of nanoparticles, by increasing of B, mass transfer characteristics will be enhanced. The effect of various nanoparticles concentrations (ϕ) within 0.002–0.01 (w/v) on K{sub L}a and E at maximum induction of RMF (B=76 mT) was evaluated. Maximum values of K{sub L}a (2.1±0.001) and E (0.884±0.001) were achieved for the layout of RMF (B=76 mT), ω=16 rad/s and MNPs concentration of 0.008–0.01 (w/v). - Highlights: • Magnetic nanoparticles used for mixing of two immiscible liquids in a micromixer. • Extraction efficiency of rotating magnetic field (RMF) is compared with static one. • In RMF, the effect of the angular speed on KLa and E enhancement is reported. • In RMF, at a selected magnet distance effect of nanoparticle concentration is reported.

  10. Static and dynamic magnetic properties of densely packed magnetic nanowire arrays

    DEFF Research Database (Denmark)

    Dmytriiev, O.; Al-Jarah, U.A.S.; Gangmei, P.

    2013-01-01

    and a continuous ferromagnetic thin film. In particular, the competition between anisotropies associated with the shape of the individual nanowires and that of the array as a whole has been studied. Measured and simulated hysteresis loops are largely anhysteretic with zero remanence, and the micromagnetic...... configuration is such that the net magnetization vanishes in directions orthogonal to the applied field. Simulations of the remanent state reveal antiferromagnetic alignment of the magnetization in adjacent nanowires and the formation of vortex flux closure structures at the ends of each nanowire....... The excitation spectra obtained from experiment and micromagnetic simulations are in qualitative agreement for magnetic fields applied both parallel and perpendicular to the axes of the nanowires. For the field parallel to the nanowire axes, there is also good quantitative agreement between experiment...

  11. High Intensity Source Laboratory (HISL)

    International Nuclear Information System (INIS)

    1992-01-01

    The High Intensity Source Laboratory (HISL) is a laboratory facility operated for the US Department of Energy (DOE) by EG ampersand G, Energy Measurements (EG ampersand G/EM). This document is intended as an overview -- primarily for external users -- of the general purposes and capabilities of HISL; numerous technical details are beyond its scope. Moreover, systems at HISL are added, deleted, and modified to suit current needs, and upgraded with continuing development. Consequently, interested parties are invited to contact the HISL manager for detailed, current, technical, and administrative information. The HISL develops and operates pulsed radiation sources with energies, intensities, and pulse widths appropriate for several applications. Principal among these are development, characterization, and calibration of various high-bandwidth radiation detectors and diagnostic systems. Hardness/vulnerability of electronic or other sensitive components to radiation is also tested. In this connection, source development generally focuses on attending (1) the highest possible intensities with (2) reasonably short pulse widths and (3) comprehensive output characterization

  12. Static Eccentricity Fault Recognition in Three-Phase Line Start Permanent Magnet Synchronous Motor Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Mahdi Karami

    2014-01-01

    Full Text Available This paper is dedicated to investigating static eccentricity in a three-phase LSPMSM. The modeling of LSPMSM with static eccentricity between stator and rotor is developed using finite element method (FEM. The analytical expression for the permeance and flux components of nonuniform air-gap due to static eccentricity fault is discussed. Various indexes for static eccentricity detection using stator current signal of IM and permanent magnet synchronous motor (PMSM are presented. Since LSPMSM is composed of a rotor which is a combination of these two motors, the ability of these features is evaluated for static eccentricity diagnosis in LSPMSM. The simulated stator current signal of LSPMSM in the presence of static eccentricity is analyzed in frequency domain using power spectral density (PSD. It is demonstrated that static eccentricity fault generates a series of low frequency harmonic components in the form of sidebands around the fundamental frequency. Moreover, the amplitudes of these components increase in proportion to the fault severity. According to the mentioned observations, an accurate frequency pattern is specified for static eccentricity detection in three-phase LSPMSM.

  13. Levitation of water and organic substances in high static magnetic fields

    Science.gov (United States)

    Beaugnon, E.; Tournier, R.

    1991-08-01

    The levitation of various diamagnetic liquid and solid substances such as water, ethanol, acetone, bismuth, antimony, graphite, wood and plastic has been achieved at room temperature in a strong inhomogeneous static magnetic field. These experiments were performed in the hybrid magnet at the Service National des Champs Intenses (CNRS, Grenoble). These findings show that high field superconducting magnets could be used to provide a contactless, low gravity environment for the elaboration of a wide range of materials. En utilisant les forts champs magnétiques produits par la bobine hybride du Service National des Champs Intenses (CNRS, Grenoble), nous avons obtenu àtempérature ambiante la lévitation de substances diamagnétiques solides ou liquides telles que l'eau, l'alcool, l'acétone, le bismuth, l'antimoine, le graphite, le bois et le plastique. Ces résultats montrent que les bobines supraconductrices peuvent être utilisées pour l'élaboration de nombreux matériaux en gravité réduite, sans contact avec un contenant.

  14. Static magnetic Faraday rotation spectroscopy combined with a differential scheme for OH detection

    Science.gov (United States)

    Zhao, Weixiong; Deng, Lunhua; Qian, Xiaodong; Fang, Bo; Gai, Yanbo; Chen, Weidong; Gao, Xiaoming; Zhang, Weijun

    2015-04-01

    The hydroxyl (OH) radical plays a critical role in atmospheric chemistry due to its high reactivity with volatile organic compounds (VOCs) and other trace gaseous species. Because of its very short life time and very low concentration in the atmosphere, interference-free high sensitivity in-situ OH monitoring by laser spectroscopy represents a real challenge. Faraday rotation spectroscopy (FRS) relies on the particular magneto-optic effect observed for paramagnetic species, which makes it capable of enhancing the detection sensitivity and mitigation of spectral interferences from diamagnetic species in the atmosphere. When an AC magnetic field is used, the Zeeman splitting of the molecular absorption line (and thus the magnetic circular birefringence) is modulated. This provides an 'internal modulation' of the sample, which permits to suppress the external noise like interference fringes. An alternative FRS detection scheme is to use a static magnetic field (DC-field) associated with laser wavelength modulation to effectively modulate the Zeeman splitting of the absorption lines. In the DC field case, wavelength modulation of the laser frequency can provide excellent performance compared to most of the sensing systems based on direct absorption and wavelength modulation spectroscopy. The dimension of the DC solenoid is not limited by the resonant frequency of the RLC circuit, which makes large dimension solenoid coil achievable and the absorption base length could be further increased. By employing a combination of the environmental photochemical reactor or smog chamber with multipass absorption cell, one can lower the minimum detection limit for high accuracy atmospheric chemistry studies. In this paper, we report on the development of a DC field based FRS in conjunction with a balanced detection scheme for OH radical detection at 2.8 μm and the construction of OH chemistry research platform which combined a large dimension superconducting magnetic coil with the

  15. Measured static hyperfine magnetic fields following implantation of Pt into Fe interpreted as evidence for pre-equilibrium effects

    International Nuclear Information System (INIS)

    Anderssen, S.S.; Stuchberry, A.E.

    1994-06-01

    The static hyperfine magnetic field present at Pt nuclei implanted in ferromagnetic Fe has been measured using the ion-implantation perturbed angular correlation (IMPAC) technique following Coulomb excitation. The present measured precessions agree with earlier data, but more recent information on the transient field correction leads to an inferred static field strength that is ∼ 25% smaller than obtained previously. Comparisons are made between the static fields measured by various techniques for Pt and neighbouring ions in iron. From these comparisons, it is show that the IMPAC data are consistent with a scenario in which (i) the static field takes about 10 ps to reach its equilibrium value, following recovery from dynamic structural damage caused by the ion-implantation process, and (ii) following equilibration, a large fraction (∼ 90%) of the implanted ions have final positions on lattice sites of the Fe host. 50 refs., 5 tabs., 7 figs

  16. Measured static hyperfine magnetic fields following implantation of Pt into Fe interpreted as evidence for pre-equilibrium effects

    Energy Technology Data Exchange (ETDEWEB)

    Anderssen, S S; Stuchberry, A E

    1994-06-01

    The static hyperfine magnetic field present at Pt nuclei implanted in ferromagnetic Fe has been measured using the ion-implantation perturbed angular correlation (IMPAC) technique following Coulomb excitation. The present measured precessions agree with earlier data, but more recent information on the transient field correction leads to an inferred static field strength that is {approx} 25% smaller than obtained previously. Comparisons are made between the static fields measured by various techniques for Pt and neighbouring ions in iron. From these comparisons, it is show that the IMPAC data are consistent with a scenario in which (i) the static field takes about 10 ps to reach its equilibrium value, following recovery from dynamic structural damage caused by the ion-implantation process, and (ii) following equilibration, a large fraction ({approx} 90%) of the implanted ions have final positions on lattice sites of the Fe host. 50 refs., 5 tabs., 7 figs.

  17. Effects of a 4.7 T static magnetic field on fetal development in ICR mice

    International Nuclear Information System (INIS)

    Okazaki, Ryuji; Ootsuyama, Akira; Uchida, Soshi; Norimura, Toshiyuki

    2001-01-01

    In order to determine the effects of a 4.7 T static magnetic field (SMF) on fetal development in mice, we evaluated fetal teratogenesis and endochondral ossification following exposure in utero. Pregnant ICR mice were exposed to a 4.7 T SMF from day 7.5 to 9.5 of gestation in a whole-body dose, and sacrificed on day 18.5 of gestation. We examined with incidence of prenatal death, external malformations and fetal skeletal malformations. There were no significant differences observed in the incidence of prenatal death and/or malformations between SMF-exposed mice and control mice. Further, we evaluated the immunoreactivity for the vascular endothelial growth factor (VEGF), which is implicated in angiogenesis and osteogenesis, in the sternum of fetal mice following magnetic exposure. Our studies also indicated that on day 16.5 of gestation following SMF exposure, the immunoreactivity for VEGF was increased compared to unexposed controls. However, it was decreased in the exposed group compared to the control group on day 18.5 of gestation. DNA and proteoglycan (PG) synthesis were also measured in rabbit costal growth plate chondrocytes in vitro. No significant differences were observed in DNA synthesis between the SMF exposed chondrocytes and the control chondrocytes; however, PG synthesis in SMF exposed chondrocytes increased compared to the controls. Based on these results, we suggest that while SMF exposure promoted the endochondral ossification of chondrocytes, it did not induce any harmful effects on fetal development in ICR mice. (author)

  18. Effects of a 4.7 T static magnetic field on fetal development in ICR mice

    Energy Technology Data Exchange (ETDEWEB)

    Okazaki, Ryuji; Ootsuyama, Akira; Uchida, Soshi; Norimura, Toshiyuki [Univ. of Occupational and Environmental Health, Kitakyushu, Fukuoka (Japan). School of Medicine

    2001-09-01

    In order to determine the effects of a 4.7 T static magnetic field (SMF) on fetal development in mice, we evaluated fetal teratogenesis and endochondral ossification following exposure in utero. Pregnant ICR mice were exposed to a 4.7 T SMF from day 7.5 to 9.5 of gestation in a whole-body dose, and sacrificed on day 18.5 of gestation. We examined with incidence of prenatal death, external malformations and fetal skeletal malformations. There were no significant differences observed in the incidence of prenatal death and/or malformations between SMF-exposed mice and control mice. Further, we evaluated the immunoreactivity for the vascular endothelial growth factor (VEGF), which is implicated in angiogenesis and osteogenesis, in the sternum of fetal mice following magnetic exposure. Our studies also indicated that on day 16.5 of gestation following SMF exposure, the immunoreactivity for VEGF was increased compared to unexposed controls. However, it was decreased in the exposed group compared to the control group on day 18.5 of gestation. DNA and proteoglycan (PG) synthesis were also measured in rabbit costal growth plate chondrocytes in vitro. No significant differences were observed in DNA synthesis between the SMF exposed chondrocytes and the control chondrocytes; however, PG synthesis in SMF exposed chondrocytes increased compared to the controls. Based on these results, we suggest that while SMF exposure promoted the endochondral ossification of chondrocytes, it did not induce any harmful effects on fetal development in ICR mice. (author)

  19. Static and quasi-elastic small angle neutron scattering on biocompatible ionic ferrofluids: magnetic and hydrodynamic interactions

    CERN Document Server

    Gazeau, F; Dubois, E; Perzynski, R

    2003-01-01

    We investigate the structure and dynamics of ionic magnetic fluids (MFs), based on ferrite nanoparticles, dispersed at pH approx 7 either in H sub 2 O or in D sub 2 O. Polarized and non-polarized static small angle neutron scattering (SANS) experiments in zero magnetic field allow us to study both the magnetic and the nuclear contributions to the neutron scattering. The magnetic interparticle attraction is probed separately from the global thermodynamic repulsion and compares well to direct magnetic susceptibility measurements. The magnetic interparticle correlation is in these fluid samples independent of the probed spatial scale. In contrast, a spatial dependence of the interparticle correlation is evidenced at large PHI by the nuclear structure factor. A model of magnetic interaction quantitatively explains the under-field anisotropy of the SANS nuclear contribution. In a quasi-elastic neutron spin-echo experiment, we probe the Brownian dynamics of translation of the nanoparticles in the range 1.3 sup<=...

  20. Antiferromagnetism in the organic conductor bis-tetramethyltetraselenafulvalene hexafluoroarsenate [(TMTSF)2AsF6]: Static magnetic susceptibility

    DEFF Research Database (Denmark)

    Mortensen, Kell; Tomkiewicz, Yaffa; Bechgaard, Klaus

    1982-01-01

    The anisotropy in the static magnetic susceptibility of bis-tetramethyltetraselenafulvalene hexafluoroarsenate [(TMTSF)2AsF6] has been investigated above and below the metal-to-insulator transition for a range of fields between 0.5 and 30 kG. The results are consistent with the expectations of a ...

  1. Estimation of genetic effects of static magnetic fields (SMFs) on the pollen mother cells (PMCs) of wheats

    International Nuclear Information System (INIS)

    Zhang Pingping; Yin Ruochun; Tang Mingli; Wu Yuejin; Yu Zengliang

    2007-01-01

    The effect of static magnetic fields (SMFs) on the chromosome aberrations in the pollen mother cells (PMCs) of wheat was studied. The seeds of wheat were exposed to static magnetic fields of different magnetic flux density (0, 1, 3, 5 and 7 Tesla) for 5h and with different treated time (1, 3 and 5h) at magnetic flux density of 7 Tesla. The genotoxic effect was evaluated in terms of micronucleus (MN), chromosomal bridge, lagging chromosome, abnormal segregation and fragment in PMCs. The results indicated that the exposed groups of low field intensity (below 5 Tesla) showed no statistically significant difference in aberration frequency compared with unexposed control groups and sham exposed groups, but significant differences of chromosomal bridge at 5T and lagging chromosome, triple-polar segregation or micronucleus at 7T were detected in the exposed group (p<0.05). The dose-effect relationships indicated that the increase frequency of meiotic abnormal cells correlated with flux density of magnetic field and treated time, but no linear effect was observed. These results lead us to the conclusion that high static magnetic fields above 5T for 5h duration might cause an increase in potential damage to organisms. (authors)

  2. Static resistivity image of a cubic saline phantom in magnetic resonance electrical impedance tomography (MREIT).

    Science.gov (United States)

    Lee, Byung Il; Oh, Suk Hoon; Woo, Eung Je; Lee, Soo Yeol; Cho, Min Hyeong; Kwon, Ohin; Seo, Jin Keun; Baek, Woon Sik

    2003-05-01

    In magnetic resonance electrical impedance tomography (MREIT) we inject currents through electrodes placed on the surface of a subject and try to reconstruct cross-sectional resistivity (or conductivity) images using internal magnetic flux density as well as boundary voltage measurements. In this paper we present a static resistivity image of a cubic saline phantom (50 x 50 x 50 mm3) containing a cylindrical sausage object with an average resistivity value of 123.7 ohms cm. Our current MREIT system is based on an experimental 0.3 T MRI scanner and a current injection apparatus. We captured MR phase images of the phantom while injecting currents of 28 mA through two pairs of surface electrodes. We computed current density images from magnetic flux density images that are proportional to the MR phase images. From the current density images and boundary voltage data we reconstructed a cross-sectional resistivity image within a central region of 38.5 x 38.5 mm2 at the middle of the phantom using the J-substitution algorithm. The spatial resolution of the reconstructed image was 64 x 64 and the reconstructed average resistivity of the sausage was 117.7 ohms cm. Even though the error in the reconstructed average resistivity value was small, the relative L2-error of the reconstructed image was 25.5% due to the noise in measured MR phase images. We expect improvements in the accuracy by utilizing an MRI scanner with higher SNR and increasing the size of voxels scarifying the spatial resolution.

  3. Static and dynamic evaluation of pelvic floor disorders with an open low-field tilting magnet

    International Nuclear Information System (INIS)

    Fiaschetti, V.; Pastorelli, D.; Squillaci, E.; Funel, V.; Rascioni, M.; Meschini, A.; Salimbeni, C.; Sileri, P.; Franceschilli, L.; Simonetti, G.

    2013-01-01

    Aim: To assess the feasibility of magnetic resonance defaecography (MRD) in pelvic floor disorders using an open tilting magnet with a 0.25 T static field and to compare the results obtained from the same patient both in supine and orthostatic positions. Materials and methods: From May 2010 to November 2011, 49 symptomatic female subjects (mean age 43.5 years) were enrolled. All the patients underwent MRD in the supine and orthostatic positions using three-dimensional (3D) hybrid contrast-enhanced (HYCE) sequences and dynamic gradient echo (GE) T1-weighted sequences. All the patients underwent conventional defaecography (CD) to correlate both results. Two radiologists evaluated the examinations; inter and intra-observer concordance was measured. The results obtained in the two positions were compared between them and with CD. Results: The comparison between CD and MRD found statistically significant differences in the evaluation of anterior and posterior rectocoele during defaecation in both positions and of rectal prolapse under the pubo-coccygeal line (PCL) during evacuation, only in the supine position (versus MRD orthostatic: rectal prolapse p < 0.0001; anterior rectocoele p < 0.001; posterior rectocoele p = 0.008; versus CD: rectal prolapse p < 0.0001; anterior rectocoele p < 0.001; posterior rectocoele p = 0.01). The value of intra-observer intra-class correlation coefficient (ICC) ranged from good to excellent; the interobserver ICC from moderate to excellent. Conclusion: MRD is feasible with an open low-field tilting magnet, and it is more accurate in the orthostatic position than in the supine position to evaluate pelvic floor disorders

  4. Static and dynamic magnetic properties of Co{sub 2}FeAl-based stripe arrays

    Energy Technology Data Exchange (ETDEWEB)

    Belmeguenai, M., E-mail: belmeguenai.mohamed@univ-paris13.fr [LSPM-CNRS, Université Paris XIII-Sorbonne Paris Cité, 93430 Villetaneuse (France); Gabor, M.S. [Center for Superconductivity, Spintronics and Surface Science, Technical University of Cluj-Napoca, Str. Memorandumului No. 28 RO-400114, Cluj-Napoca (Romania); Zighem, F. [LSPM-CNRS, Université Paris XIII-Sorbonne Paris Cité, 93430 Villetaneuse (France); Berling, D. [IS2M, CNRS-LRC 7228, Université de Haute-Alsace, 68057 Mulhouse-Cedex (France); Roussigné, Y. [LSPM-CNRS, Université Paris XIII-Sorbonne Paris Cité, 93430 Villetaneuse (France); Petrisor, T. [Center for Superconductivity, Spintronics and Surface Science, Technical University of Cluj-Napoca, Str. Memorandumului No. 28 RO-400114, Cluj-Napoca (Romania); Chérif, S.M. [LSPM-CNRS, Université Paris XIII-Sorbonne Paris Cité, 93430 Villetaneuse (France); Tiusan, C. [Center for Superconductivity, Spintronics and Surface Science, Technical University of Cluj-Napoca, Str. Memorandumului No. 28 RO-400114, Cluj-Napoca (Romania); Institut Jean Lamour, CNRS, Université de Nancy, BP 70239, F-54506 Vandoeuvre (France); Brinza, O.; Moch, P. [LSPM-CNRS, Université Paris XIII-Sorbonne Paris Cité, 93430 Villetaneuse (France)

    2016-02-01

    25 nm to 50 nm Co{sub 2}FeAl (CFA) thick wire arrays with varying widths and spacing have been patterned from continuous CFA films deposited on MgO(001) using e-beam lithography and Ar ion milling. Magneto-optical Kerr effect, transverse bias initial inverse susceptibility and torque measurements reveal that the in-plane magnetic anisotropy of the wires is dominantly monitored by a uniaxial term, in contrast with the continuous films where it is governed by the superposition of a fourfold term and of a smaller uniaxial term. The microstrip ferromagnetic resonance spectra performed using a magnetic field H, applied in the plane of the studied sample along various directions, or perpendicularly to this plane, gave us access to various quantized modes originating from the patterning. In addition, Brillouin light scattering also exhibits quantized modes. A large part of the experimental observations can be quantitatively interpreted as resulting from the demagnetizing terms induced by the geometrical patterning. However, the presented model, simply built on the effect of the demagnetizing field, is not able to give account of all the quantized modes present in the resonance spectra. When H is parallel to the wires, a more complete description is used: it considers the wave-vector quantization induced by the patterning. For the magnetic modes concerned by both approaches, the correspondence between the 2 models is easily established. When H is not parallel to the wires quantitative descriptions of the behavior of the field dependence of the observed modes still can often be performed. Finally, in all the studied patterned samples, the uniform magnetic mode, termed “film mode”, relative to the parent continuous film is observed by ferromagnetic resonance: such a behavior, which has been reported previously, remains to be completely interpreted. - Highlights: • The static and dynamic properties of Co{sub 2}FeAl wire arrays have been studied. • Microstrip

  5. Static magnetic field therapy for symptomatic diabetic neuropathy: a randomized, double-blind, placebo-controlled trial.

    Science.gov (United States)

    Weintraub, Michael I; Wolfe, Gil I; Barohn, Richard A; Cole, Steven P; Parry, Gareth J; Hayat, Ghazala; Cohen, Jeffrey A; Page, Jeffrey C; Bromberg, Mark B; Schwartz, Sherwyn L

    2003-05-01

    To determine if constant wearing of multipolar, static magnetic (450G) shoe insoles can reduce neuropathic pain and quality of life (QOL) scores in symptomatic diabetic peripheral neuropathy (DPN). Randomized, placebo-control, parallel study. Forty-eight centers in 27 states. Three hundred seventy-five subjects with DPN stage II or III were randomly assigned to wear constantly magnetized insoles for 4 months; the placebo group wore similar, unmagnetized device. Nerve conduction and/or quantified sensory testing were performed serially. Daily visual analog scale scores for numbness or tingling and burning and QOL issues were tabulated over 4 months. Secondary measures included nerve conduction changes, role of placebo, and safety issues. Analysis of variance (ANOVA), analysis of covariance (ANCOVA), and chi-square analysis were performed. There were statistically significant reductions during the third and fourth months in burning (mean change for magnet treatment, -12%; for sham, -3%; P<.05, ANCOVA), numbness and tingling (magnet, -10%; sham, +1%; P<.05, ANCOVA), and exercise-induced foot pain (magnet, -12%; sham, -4%; P<.05, ANCOVA). For a subset of patients with baseline severe pain, statistically significant reductions occurred from baseline through the fourth month in numbness and tingling (magnet, -32%; sham, -14%; P<.01, ANOVA) and foot pain (magnet, -41%; sham, -21%; P<.01, ANOVA). Static magnetic fields can penetrate up to 20mm and appear to target the ectopic firing nociceptors in the epidermis and dermis. Analgesic benefits were achieved over time.

  6. Finite-size effects on the dynamic susceptibility of CoPhOMe single-chain molecular magnets in presence of a static magnetic field

    Science.gov (United States)

    Pini, M. G.; Rettori, A.; Bogani, L.; Lascialfari, A.; Mariani, M.; Caneschi, A.; Sessoli, R.

    2011-09-01

    The static and dynamic properties of the single-chain molecular magnet Co(hfac)2NITPhOMe (CoPhOMe) (hfac = hexafluoroacetylacetonate, NITPhOMe = 4'-methoxy-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) are investigated in the framework of the Ising model with Glauber dynamics, in order to take into account both the effect of an applied magnetic field and a finite size of the chains. For static fields of moderate intensity and short chain lengths, the approximation of a monoexponential decay of the magnetization fluctuations is found to be valid at low temperatures; for strong fields and long chains, a multiexponential decay should rather be assumed. The effect of an oscillating magnetic field, with intensity much smaller than that of the static one, is included in the theory in order to obtain the dynamic susceptibility χ(ω). We find that, for an open chain with N spins, χ(ω) can be written as a weighted sum of N frequency contributions, with a sum rule relating the frequency weights to the static susceptibility of the chain. Very good agreement is found between the theoretical dynamic susceptibility and the ac susceptibility measured in moderate static fields (Hdc≤2 kOe), where the approximation of a single dominating frequency for each segment length turns out to be valid. For static fields in this range, data for the relaxation time, τ versus Hdc, of the magnetization of CoPhOMe at low temperature are also qualitatively reproduced by theory, provided that finite-size effects are included.

  7. Effect of biological characteristics of different types of uterine fibroids, as assessed with T2-weighted magnetic resonance imaging, on ultrasound-guided high-intensity focused ultrasound ablation.

    Science.gov (United States)

    Zhao, Wen-Peng; Chen, Jin-Yun; Chen, Wen-Zhi

    2015-02-01

    The aims of this study were to assess the effects of the biological characteristics of different types of uterine fibroids, as assessed with T2-weighted magnetic resonance imaging (MRI), on ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation. Thirty-five patients with 39 symptomatic uterine fibroids who underwent myomectomy or hysterectomy were enrolled. Before surgery, the uterine fibroids were subdivided into hypo-intense, iso-intense, heterogeneous hyper-intense and homogeneous hyper-intense categories based on signal intensity on T2-weighted MRI. Tissue density and moisture content were determined in post-operative samples and normal uterine tissue, the isolated uterine fibroids were subjected to USgHIFU, and the extent of ablation was measured using triphenyltetrazolium chloride. Hematoxylin and eosin staining and sirius red staining were undertaken to investigate the organizational structure of the uterine fibroids. Estrogen and progesterone receptor expression was assayed via immunohistochemical staining. The mean diameter of uterine fibroids was 6.9 ± 2.8 cm. For all uterine fibroids, the average density and moisture content were 10.7 ± 0.7 mg/mL and 75.7 ± 2.4%, respectively; and for the homogeneous hyper-intense fibroids, 10.3 ± 0.5 mg/mL and 76.6 ± 2.3%. The latter subgroup had lower density and higher moisture content compared with the other subgroups. After USgHIFU treatment, the extent of ablation of the hyper-intense fibroids was 102.7 ± 42.1 mm(2), which was significantly less than those of the hypo-intense and heterogeneous hyper-intense fibroids. Hematoxylin and eosin staining and sirius red staining revealed that the homogeneous hyper-intense fibroids had sparse collagen fibers and abundant cells. Immunohistochemistry results revealed that estrogen and progesterone receptors were highly expressed in the homogeneous hyper-intense fibroids. This study revealed that lower density, higher moisture content, sparse collagen

  8. WE-EF-BRA-12: Magnetic Resonance- Guided High-Intensity Focused Ultrasound for Localized Ablation of Head and Neck Tissue Structures: A Feasibility Study in An Animal Model

    International Nuclear Information System (INIS)

    Partanen, A; Ellens, N; Noureldine, S; Tufano, R; Burdette, E; Farahani, K

    2015-01-01

    Purpose: High-intensity focused ultrasound (HIFU) ablation is feasible in the head and neck [1]. This study aims to expand upon these findings to assess the feasibility of treatment planning and monitoring via magnetic resonance imaging (MRI) guidance using a clinical MR-guided HIFU platform. Methods: Two 31 kg pigs were anaesthetized, shaved, and positioned prone on the HIFU table (Sonalleve, Philips Healthcare, Vantaa, Finland). The necks were acoustically coupled to the integrated transducer using gel pads and degassed water. MR imaging verified acoustic coupling and facilitated target selection in the thyroid and thymus. Targets were thermally ablated with 130–200 W of acoustic power over a period of 16 s at a frequency of 1.2 MHz while being monitored through real-time, multi-planar MR-thermometry. Contrast-enhanced MR imaging was used to assess treatment efficacy. Post-treatment, animals were euthanized and sonicated tissues were harvested for histology assessment. Results: MR-thermometry, post-contrast-imaging, and gross pathology demonstrated that the system was capable of causing localized thermal ablation in both the thyroid and the thymus without damaging the aerodigestive tract. In one animal, superficial bruising was observed in the ultrasound beam path. Otherwise, there were no adverse events. Analysis of the tissue histology found regions of damage consistent with acute thermal injury at the targeted locations. Conclusion: It is feasible to use a clinical MR-guided HIFU platform for extracorporeal ablation of porcine head and neck tissues. MR guidance and thermometry are sufficient to target and monitor treatment in the thyroid region, despite the presence of the inhomogeneous aerodigestive tract. Further study is necessary to assess efficacy and survival using a tumor model, and to examine what modifications should be made to the transducer positioning system and associated patient positioning aids to adapt it for clinical head and neck targets

  9. Effect of a static magnetic field on silicon transport in liquid phase diffusion growth of SiGe

    Energy Technology Data Exchange (ETDEWEB)

    Armour, N.; Dost, S. [Crystal Growth Laboratory, University of Victoria, Victoria, BC V8W 3P6 (Canada)

    2010-03-15

    Liquid phase diffusion experiments have been performed without and with the application of a 0.4 T static magnetic field using a three-zone DC furnace system. SiGe crystals were grown from the germanium side for a period of 72 h. Experiments have led to the growth of single crystal sections varying from 0 to 10 mm thicknesses. Examination of the processed samples (single and polycrystalline sections) has shown that the effect of the applied static magnetic field is significant. It alters the temperature distribution in the system, reduces mass transport in the melt, and leads to a much lower growth rate. The initial curved growth interface was slightly flattened under the effect of magnetic field. There were no growth striations in the single crystal sections of the samples. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Weak Static and Extremely Low Frequency Magnetic Fields Affect In Vitro Pollen Germination

    Directory of Open Access Journals (Sweden)

    Lucietta Betti

    2011-01-01

    Full Text Available This study concerns the effects of a weak static magnetic field (MF at 10 μT oriented downward, combined with a 16-Hz sinusoidal MF (10 μT, on in vitro pollen germination of kiwifruit (Actinidia deliciosa. Extremely low frequency magnetic field (ELF-MF exposure was carried out by a signal generator unit connected to a copper wire solenoid, inside which samples where placed. Two different kinds of treatment were performed: direct and indirect. In the direct treatment, pollen samples were directly exposed during rehydration, germination, or both. In the indirect treatment, the pollen growth medium was prepared with water aliquots (at standard temperature of 20°C and pH = 6.74 that were exposed before use for 8 or 24 h. The main purpose of our research was to identify a biological marker (in vitro pollen germination in a stressing growth medium without Ca2+ susceptible to the effects of direct or indirect ELF-MF exposure. The working variable was the pollen germination rate, as detected blind after 3 h 30 min by an Axioplan microscope. A directionally consistent recovery of germination percentage was observed both for direct exposure (during germination and both rehydration and germination phases and water-mediated exposure (with water exposed for 24 h and immediately used. Our results suggest that the ELF-MF treatment might partially remove the inhibitory effect caused by the lack of Ca2+ in the culture medium, inducing a release of internal Ca2+ stored in the secretory vesicles of pollen plasma membrane. Although preliminary, findings seem to indicate the in vitro pollen performance as adequate to study the effects of ELF-MFs on living matter.

  11. Static magnetic field exposure reproduces cellular effects of the Parkinson's disease drug candidate ZM241385.

    Directory of Open Access Journals (Sweden)

    Zhiyun Wang

    2010-11-01

    Full Text Available This study was inspired by coalescing evidence that magnetic therapy may be a viable treatment option for certain diseases. This premise is based on the ability of moderate strength fields (i.e., 0.1 to 1 Tesla to alter the biophysical properties of lipid bilayers and in turn modulate cellular signaling pathways. In particular, previous results from our laboratory (Wang et al., BMC Genomics, 10, 356 (2009 established that moderate strength static magnetic field (SMF exposure altered cellular endpoints associated with neuronal function and differentiation. Building on this background, the current paper investigated SMF by focusing on the adenosine A(2A receptor (A(2AR in the PC12 rat adrenal pheochromocytoma cell line that displays metabolic features of Parkinson's disease (PD.SMF reproduced several responses elicited by ZM241385, a selective A(2AR antagonist, in PC12 cells including altered calcium flux, increased ATP levels, reduced cAMP levels, reduced nitric oxide production, reduced p44/42 MAPK phosphorylation, inhibited proliferation, and reduced iron uptake. SMF also counteracted several PD-relevant endpoints exacerbated by A(2AR agonist CGS21680 in a manner similar to ZM241385; these include reduction of increased expression of A(2AR, reversal of altered calcium efflux, dampening of increased adenosine production, reduction of enhanced proliferation and associated p44/42 MAPK phosphorylation, and inhibition of neurite outgrowth.When measured against multiple endpoints, SMF elicited qualitatively similar responses as ZM241385, a PD drug candidate. Provided that the in vitro results presented in this paper apply in vivo, SMF holds promise as an intriguing non-invasive approach to treat PD and potentially other neurological disorders.

  12. Static Magnetic Field Exposure Reproduces Cellular Effects of the Parkinson's Disease Drug Candidate ZM241385

    Science.gov (United States)

    Wang, Zhiyun; Che, Pao-Lin; Du, Jian; Ha, Barbara; Yarema, Kevin J.

    2010-01-01

    Background This study was inspired by coalescing evidence that magnetic therapy may be a viable treatment option for certain diseases. This premise is based on the ability of moderate strength fields (i.e., 0.1 to 1 Tesla) to alter the biophysical properties of lipid bilayers and in turn modulate cellular signaling pathways. In particular, previous results from our laboratory (Wang et al., BMC Genomics, 10, 356 (2009)) established that moderate strength static magnetic field (SMF) exposure altered cellular endpoints associated with neuronal function and differentiation. Building on this background, the current paper investigated SMF by focusing on the adenosine A2A receptor (A2AR) in the PC12 rat adrenal pheochromocytoma cell line that displays metabolic features of Parkinson's disease (PD). Methodology and Principal Findings SMF reproduced several responses elicited by ZM241385, a selective A2AR antagonist, in PC12 cells including altered calcium flux, increased ATP levels, reduced cAMP levels, reduced nitric oxide production, reduced p44/42 MAPK phosphorylation, inhibited proliferation, and reduced iron uptake. SMF also counteracted several PD-relevant endpoints exacerbated by A2AR agonist CGS21680 in a manner similar to ZM241385; these include reduction of increased expression of A2AR, reversal of altered calcium efflux, dampening of increased adenosine production, reduction of enhanced proliferation and associated p44/42 MAPK phosphorylation, and inhibition of neurite outgrowth. Conclusions and Significance When measured against multiple endpoints, SMF elicited qualitatively similar responses as ZM241385, a PD drug candidate. Provided that the in vitro results presented in this paper apply in vivo, SMF holds promise as an intriguing non-invasive approach to treat PD and potentially other neurological disorders. PMID:21079735

  13. Adaptation of Salmonella enterica Hadar under static magnetic field: effects on outer membrane protein pattern

    Directory of Open Access Journals (Sweden)

    Snoussi Sarra

    2012-02-01

    Full Text Available Abstract Background Salmonella enterica serovar Hadar (S. Hadar is a highly prevalent foodborne pathogen and therefore a major cause of human gastroenteritis worldwide. Outer membrane proteins whose production is often regulated by environmental conditions also play important roles in the adaptability of bacterial pathogens to various environments. Results The present study investigated the adaptation of S. Hadar under the effect of acute static magnetic field exposure (200 mT, 9 h and the impact on the outer membrane protein pattern. Via two-dimensional electrophoresis (2-DE and LC-MS/MS spectrometry, we compared the proteome of enriched-outer membrane fraction before and after exposure to a magnetic field. A total of 11 proteins, displaying more than a two-fold change, were differentially expressed in exposed cells, among which 7 were up-regulated and 4 down-regulated. These proteins were involved in the integrity of cell envelope (TolB, Pal, in the response to oxidative stress (OmpW, dihydrolipoamide dehydrogenase, UspF, in the oxidative stress status (bacterioferritin, in virulence (OmpX, Yfgl or in motility (FlgE and UspF. Complementary experiments associated the down-regulation of FlgE and UspF with an alteration of swarming, a flagella-driven motility, under SMF. Furthermore, the antibiotic disc diffusion method confirmed a decrease of gentamicin susceptibility in exposed cells. This decrease could be partly associated with the up-regulation of TolC, outer membrane component of an efflux pump. OmpA, a multifunctional protein, was up-regulated. Conclusions SMF (200 mT seems to maintain the cell envelope integrity and to submit the exposed cells to an oxidative stress. Some alterations suggest an increase of the ability of exposed cells to form biofilms.

  14. Static magnetic field treatment of seeds improves carbon and nitrogen metabolism under salinity stress in soybean.

    Science.gov (United States)

    Baghel, Lokesh; Kataria, Sunita; Guruprasad, Kadur Narayan

    2016-10-01

    The effectiveness of magnetopriming was assessed for alleviation of salt-induced adverse effects on soybean growth. Soybean seeds were pre-treated with static magnetic field (SMF) of 200 mT for 1 h to evaluate the effect of magnetopriming on growth, carbon and nitrogen metabolism, and yield of soybean plants under different salinity levels (0, 25, and 50 mM NaCl). The adverse effect of NaCl-induced salt stress was found on growth, yield, and various physiological attributes of soybeans. Results indicate that SMF pre-treatment significantly increased plant growth attributes, number of root nodules, nodules, fresh weight, biomass accumulation, and photosynthetic performance under both non-saline and saline conditions as compared to untreated seeds. Polyphasic chlorophyll a fluorescence (OJIP) transients from magnetically treated plants gave a higher fluorescence yield at J-I-P phase. Nitrate reductase activity, PIABS , photosynthetic pigments, and net rate of photosynthesis were also higher in plants that emerged from SMF pre-treated seeds as compared to untreated seeds. Leghemoglobin content and hemechrome content in root nodules were also increased by SMF pre-treatment. Thus pre-sowing exposure of seeds to SMF enhanced carbon and nitrogen metabolism and improved the yield of soybeans in terms of number of pods, number of seeds, and seed weight under saline as well as non-saline conditions. Consequently, SMF pre-treatment effectively mitigated adverse effects of NaCl on soybeans. It indicates that magnetopriming of dry soybean seeds can be effectively used as a pre-sowing treatment for alleviating salinity stress. Bioelectromagnetics. 37:455-470, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. Antioxidant enzymes response induced by static magnetic field in pregnant rats

    International Nuclear Information System (INIS)

    Chater, S.; Abdelmelek, H.; Garrel, C.; Favier, A.; Sakly, M.; Rhouma, K.B.

    2005-01-01

    Some recent epidemiologic studies have suggested that static magnetic fields (MF) affect human health and, in particular, that the incidence of certain types of cancer, depression, and miscarriage might increase among individuals living or working in environments exposed to such fields. However, despite numerous studies concerning MF, the mechanism of its adverse effect still remains unknown. So, our work hypothesis was that abortion effects induced by MF exposure could be due to an over production of reactive oxygen species produced by pregnant rats. The aim of our study was to examine if MF was able to induce an oxidative stress in pregnant-rats. Pregnant female Wistar rats were exposed to MF (128 mT/1h/day) on day 6 to 19 of gestation. Animals were sacrificed three days after delivery and plasma was collected to determine malondialdehyde (MDA), an indirect oxidative stress marker, glutathion peroxidase activity (GPX), an antioxydant enzyme, and the total antioxidant status (TAS). MF exposure had no effects on MDA level (2.97 ± 0.50 μmol/l vs 2.62 ±0.19 μmol/l, p>0.05) and plasma GPX activity (6936.00 ±109.59 U/l vs 6258.00 ±111.12 U/l, p>0.05). Interestingly, MF exposure induced elevation in the total antioxidant status values (0.716 ±0.018 mmol/l vs 0.646 ±0.023 mmol/l, p<0.05). The results indicated that sub-acute exposures to magnetic field during rat pregnancy have no effects on lipid peroxidation, probably related to the protection role of antioxidant enzymes

  16. Static Magnetic Field Attenuates Lipopolysaccharide-Induced Inflammation in Pulp Cells by Affecting Cell Membrane Stability

    Directory of Open Access Journals (Sweden)

    Sung-Chih Hsieh

    2015-01-01

    Full Text Available One of the causes of dental pulpitis is lipopolysaccharide- (LPS- induced inflammatory response. Following pulp tissue inflammation, odontoblasts, dental pulp cells (DPCs, and dental pulp stem cells (DPSCs will activate and repair damaged tissue to maintain homeostasis. However, when LPS infection is too serious, dental repair is impossible and disease may progress to irreversible pulpitis. Therefore, the aim of this study was to examine whether static magnetic field (SMF can attenuate inflammatory response of dental pulp cells challenged with LPS. In methodology, dental pulp cells were isolated from extracted teeth. The population of DPSCs in the cultured DPCs was identified by phenotypes and multilineage differentiation. The effects of 0.4 T SMF on DPCs were observed through MTT assay and fluorescent anisotropy assay. Our results showed that the SMF exposure had no effect on surface markers or multilineage differentiation capability. However, SMF exposure increases cell viability by 15%. In addition, SMF increased cell membrane rigidity which is directly related to higher fluorescent anisotropy. In the LPS-challenged condition, DPCs treated with SMF demonstrated a higher tolerance to LPS-induced inflammatory response when compared to untreated controls. According to these results, we suggest that 0.4 T SMF attenuates LPS-induced inflammatory response to DPCs by changing cell membrane stability.

  17. Effect of a static external magnetic perturbation on resistive mode stability in tokamaks

    International Nuclear Information System (INIS)

    Fitzpatrick, R.

    1994-03-01

    The influence of a general static external magnetic perturbation on the stability of resistive modes in a tokamak plasma is examined. There are three main parts to this investigation. Firstly, the vacuum perturbation is expanded as a set of well-behaved toroidal ring functions and is, thereafter, specified by the coefficients of this expansion. Secondly, a dispersion relation is derived for resistive plasma instabilities in the presence of a general external perturbation and finally, this dispersion relation is solved for the amplitudes of the tearing and twisting modes driven in the plasma by a specific perturbation. It is found that the amplitudes of driven tearing and twisting modes are negligible until a certain critical perturbation strength is exceeded. Only tearing modes are driven in low-β plasmas with εβ p p ∼>1. For error-field perturbations made up of a large number of different poloidal and toroidal harmonics the critical strength to drive locked modes has a open-quote staircase close-quote variation with edge-q, characterized by strong discontinuities as coupled rational surfaces enter or leave the plasma. For single harmonic perturbations the variation with edge-q is far smoother. Both types of behaviour have been observed experimentally. The critical perturbation strength is found to decrease strongly close to an ideal external kink stability boundary. This is also in agreement with experimental observations

  18. Study on Application of Static Magnetic Field for Adjuvant Arthritis Rats

    Directory of Open Access Journals (Sweden)

    Norimasa Taniguchi

    2004-01-01

    Full Text Available In order to examine the effectiveness of the application of static magnetic field (SMF on pain relief, we performed a study on rats with adjuvant arthritis (AA. Sixty female Sprague–Dawley (SD rats (age: 6 weeks, body weight: approximately 160 g were divided into three groups [SMF-treated AA rats (Group I, non-SMF-treated AA rats (Group II and control rats (Group III]. The SD rats were injected in the left hind leg with 0.6 mg/0.05 ml Mycobacterium butyrium to induce AA. The rats were bred for 6 months as chronic pain model. Thereafter, the AA rats were or were not exposed to SMF for 12 weeks. We assessed the changes in the tail surface temperature, locomotor activity, serum inflammatory marker and bone mineral density (BMD using thermography, a metabolism measuring system and the dual-energy X-ray absorptiometry (DEXA method, respectively. The tail surface temperature, locomotor activity and femoral BMD of the SMF-exposed AA rats were significantly higher than those of the non-SMF-exposed AA rats, and the serum inflammatory marker was significantly lower. These findings suggest that the pain relief effects are primarily due to the increased blood circulation caused by the rise in the tail surface temperature. Moreover, the pain relief effects increased with activity and BMD of the AA rats.

  19. Efficacy of Static Magnetic Field for Locomotor Activity of Experimental Osteopenia

    Directory of Open Access Journals (Sweden)

    Norimasa Taniguchi

    2007-01-01

    Full Text Available In order to examine the effectiveness of applying a static magnetic field (SMF for increasing bone mineral density (BMD, we assessed the degree of osteopenia by dual-energy X-ray absorptiometry (DEXA, the metabolism measuring system, and histological examination of bone tissue in an ovariectomized (OVX rat model. Thirty-six female Wistar rats (8 weeks old, 160–180 g were divided into three groups. The rats in the OVX-M group were exposed to SMF for 12 weeks after ovariectomy. The ovariectomized rats in the OVX-D group were not exposed to SMF as a control. The rats in the normal group received neither ovariectomy nor exposure to SMF. Twelve-week exposure to SMF in the OVX-M group inhibited the reduction in BMD that was observed in the OVX-D group. Moreover, in the OVX rats, before exposure to SMF, there was no clear difference in the level of locomotor activity between the active and resting phases, and the pattern of locomotor activity was irregular. After exposure of OVX rats to SMF, the pattern of locomotor activity became diphasic with clear active and resting phases, as was observed in the normal group. In the OVX-M group, the continuity of the trabecular bone was maintained more favorably and bone mass was higher than the respective parameters in the OVX-D group. These results demonstrate that exposure to SMF increased the level of locomotor activity in OVX rats, thereby increasing BMD.

  20. Laboratory Studies of the Effects of Static and Variable Magnetic Fields on Freshwater Fish

    Energy Technology Data Exchange (ETDEWEB)

    Cada, Glenn F [ORNL; Bevelhimer, Mark S [ORNL; Fortner, Allison M [ORNL; Riemer, Kristina P [ORNL; Schweizer, Peter E [ORNL

    2012-04-01

    benthic invertebrates (Gill et al. 2005, 2009). It is known that numerous marine and freshwater organisms are sensitive to electrical and magnetic fields, often depending on them for such diverse activities as prey location and navigation (DOE 2009; Normandeau et al. 2011). Despite the wide range of aquatic organisms that are sensitive to EMF and the increasing numbers of underwater electrical transmitting cables being installed in rivers and coastal waters, little information is available to assess whether animals will be attracted, repelled, or unaffected by these new sources of EMF. This knowledge gap is especially significant for freshwater systems, where electrosensitive organisms such as paddlefish and sturgeon may interact with electrical transmission cables. We carried out a series of laboratory experiments to test the sensitivity of freshwater fish and invertebrates to the levels of EMF that are expected to be produced by HK projects in rivers. In this context, EM fields are likely to be emitted primarily by generators in the water column and by transmission cables on or buried in the substrate. The HK units will be located in areas of high-velocity waters that are used as only temporary habitats for most riverine species, so long-term exposure of fish and benthic invertebrates to EMF is unlikely. Rather, most aquatic organisms will be briefly exposed to the fields as they drift downstream or migrate upstream. Because the exposure of most aquatic organisms to EMF in a river would be relatively brief and non-lethal, we focused our investigations on detecting behavioral effects. For example, attraction to the EM fields could result in prolonged exposures to the fields or the HK rotor. On the other hand, avoidance reactions might hinder upstream migrations of fish. The experiments reported here are a continuation of studies begun in FY 2010, which focused on the potential effects of static magnetic fields on snails, clams, and fathead minnows (Cada et al. 2011

  1. HELIOS: A high intensity chopper spectrometer at LANSCE

    International Nuclear Information System (INIS)

    Mason, T.E.; Broholm, C.; Fultz, B.

    1998-01-01

    A proposal to construct a high intensity chopper spectrometer at LANSCE as part of the SPSS upgrade project is discussed. HELIOS will be optimized for science requiring high sensitivity neutron spectroscopy. This includes studies of phonon density of states in small polycrystalline samples, magnetic excitations in quantum magnets and highly correlated electron systems, as well as parametric studies (as a function of pressure, temperature, or magnetic field) of S(Q,ω). By employing a compact design together with the use of supermirror guide in the incident flight path the neutron flux at HELIOS will be significantly higher than any other comparable instrument now operating

  2. HELIOS: A high intensity chopper spectrometer at LANSCE

    Energy Technology Data Exchange (ETDEWEB)

    Mason, T.E. [Oak Ridge National Lab., TN (United States); Broholm, C. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Physics and Astronomy; Fultz, B. [California Inst. of Tech., Pasadena, CA (United States). Dept. of Materials Science] [and others

    1998-12-31

    A proposal to construct a high intensity chopper spectrometer at LANSCE as part of the SPSS upgrade project is discussed. HELIOS will be optimized for science requiring high sensitivity neutron spectroscopy. This includes studies of phonon density of states in small polycrystalline samples, magnetic excitations in quantum magnets and highly correlated electron systems, as well as parametric studies (as a function of pressure, temperature, or magnetic field) of S(Q,{omega}). By employing a compact design together with the use of supermirror guide in the incident flight path the neutron flux at HELIOS will be significantly higher than any other comparable instrument now operating.

  3. Fe3O4/BSA particles induce osteogenic differentiation of mesenchymal stem cells under static magnetic field.

    Science.gov (United States)

    Jiang, Pengfei; Zhang, Yixian; Zhu, Chaonan; Zhang, Wenjing; Mao, Zhengwei; Gao, Changyou

    2016-12-01

    Differentiation of stem cells is influenced by many factors, yet uptake of the magnetic particles with or without magnetic field is rarely tackled. In this study, iron oxide nanoparticles-loaded bovine serum albumin (BSA) (Fe 3 O 4 /BSA) particles were prepared, which showed a spherical morphology with a diameter below 200 nm, negatively charged surface, and tunable magnetic property. The particles could be internalized into bone marrow mesenchymal stem cells (MSCs), and their release from the cells was significantly retarded under external magnetic field, resulting in almost twice intracellular amount of the particles within 21 d compared to that of the magnetic field free control. Uptake of the Fe 3 O 4 /BSA particles enhanced significantly the osteogenic differentiation of MSCs under a static magnetic field, as evidenced by elevated alkaline phosphatase (ALP) activity, calcium deposition, and expressions of collagen type I and osteocalcin at both mRNA and protein levels. Therefore, uptake of the Fe 3 O 4 /BSA particles brings significant influence on the differentiation of MSCs under magnetic field, and thereby should be paid great attention for practical applications. Differentiation of stem cells is influenced by many factors, yet uptake of the magnetic particles with or without magnetic field is rarely tackled. In this study, iron oxide nanoparticles-loaded bovine serum albumin (BSA) (Fe 3 O 4 /BSA) particles with a diameter below 200nm, negatively charged surface, tunable Fe 3 O 4 content and subsequently adjustable magnetic property were prepared. The particles could be internalized into bone marrow mesenchymal stem cells (MSCs), and their release from the cells was significantly retarded under external magnetic field. Uptake of the Fe 3 O 4 /BSA particles enhanced significantly the osteogenic differentiation of MSCs under a constant static magnetic field, while the magnetic particles and external magnetic field alone do not influence significantly the

  4. Constants of motion for the planar orbit of a charged particle in a static and uniform magnetic field: the magnetic Laplace–Runge–Lenz vector

    International Nuclear Information System (INIS)

    Velasco-Martínez, D; Kunold, A; Cardoso, J L; Ibarra-Sierra, V G; Sandoval-Santana, J C

    2014-01-01

    In this paper we introduce an alternative approach to studying the motion of a planar charged particle subject to a static uniform magnetic field. It is well known that an electric charge under a uniform magnetic field has a planar motion if its initial velocity is perpendicular to the magnetic field. Although some constants of motion (CsM), as the energy and the angular momentum, have been widely discussed for this system, others have been neglected. We find that the angular momentum, the generator of the magnetic translations and the magnetic Laplace–Runge–Lenz vector are CsM for this particular system. We show also that these three quantities form an orthogonal basis of vectors. The present work addresses many aspects of the motion of a charged particle in a magnetic field that should be useful for students and tutors of the classical mechanics courses at the senior undergraduate level. (paper)

  5. Distinct Nature of Static and Dynamic Magnetic Stripes in Cuprate Superconductors

    DEFF Research Database (Denmark)

    Jacobsen, H.; Holm, S. L.; Lăcătuşu, M. E.

    2018-01-01

    We present detailed neutron scattering studies of the static and dynamic stripes in an optimally doped high-Temperature superconductor, La2CuO4+y. We observe that the dynamic stripes do not disperse towards the static stripes in the limit of vanishing energy transfer. Therefore, the dynamic stripes...

  6. High Intensity Exercise in Multiple Sclerosis

    DEFF Research Database (Denmark)

    Wens, Inez; Dalgas, Ulrik; Vandenabeele, Frank

    2015-01-01

    Introduction Low-to-moderate intensity exercise improves muscle contractile properties and endurance capacity in multiple sclerosis (MS). The impact of high intensity exercise remains unknown. Methods Thirty-four MS patients were randomized into a sedentary control group (SED, n = 11) and 2...... exercise groups that performed 12 weeks of a high intensity interval (HITR, n = 12) or high intensity continuous cardiovascular training (HCTR, n = 11), both in combination with resistance training. M.vastus lateralis fiber cross sectional area (CSA) and proportion, knee-flexor/extensor strength, body...... composition, maximal endurance capacity and self-reported physical activity levels were assessed before and after 12 weeks. Results Compared to SED, 12 weeks of high intensity exercise increased mean fiber CSA (HITR: +21±7%, HCTR: +23±5%). Furthermore, fiber type I CSA increased in HCTR (+29±6%), whereas type...

  7. Recording visual evoked potentials and auditory evoked P300 at 9.4T static magnetic field.

    Science.gov (United States)

    Arrubla, Jorge; Neuner, Irene; Hahn, David; Boers, Frank; Shah, N Jon

    2013-01-01

    Simultaneous recording of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) has shown a number of advantages that make this multimodal technique superior to fMRI alone. The feasibility of recording EEG at ultra-high static magnetic field up to 9.4 T was recently demonstrated and promises to be implemented soon in fMRI studies at ultra high magnetic fields. Recording visual evoked potentials are expected to be amongst the most simple for simultaneous EEG/fMRI at ultra-high magnetic field due to the easy assessment of the visual cortex. Auditory evoked P300 measurements are of interest since it is believed that they represent the earliest stage of cognitive processing. In this study, we investigate the feasibility of recording visual evoked potentials and auditory evoked P300 in a 9.4 T static magnetic field. For this purpose, EEG data were recorded from 26 healthy volunteers inside a 9.4 T MR scanner using a 32-channel MR compatible EEG system. Visual stimulation and auditory oddball paradigm were presented in order to elicit evoked related potentials (ERP). Recordings made outside the scanner were performed using the same stimuli and EEG system for comparison purposes. We were able to retrieve visual P100 and auditory P300 evoked potentials at 9.4 T static magnetic field after correction of the ballistocardiogram artefact using independent component analysis. The latencies of the ERPs recorded at 9.4 T were not different from those recorded at 0 T. The amplitudes of ERPs were higher at 9.4 T when compared to recordings at 0 T. Nevertheless, it seems that the increased amplitudes of the ERPs are due to the effect of the ultra-high field on the EEG recording system rather than alteration in the intrinsic processes that generate the electrophysiological responses.

  8. High intensity neutrino oscillation facilities in Europe

    Directory of Open Access Journals (Sweden)

    T. R. Edgecock

    2013-02-01

    Full Text Available The EUROnu project has studied three possible options for future, high intensity neutrino oscillation facilities in Europe. The first is a Super Beam, in which the neutrinos come from the decay of pions created by bombarding targets with a 4 MW proton beam from the CERN High Power Superconducting Proton Linac. The far detector for this facility is the 500 kt MEMPHYS water Cherenkov, located in the Fréjus tunnel. The second facility is the Neutrino Factory, in which the neutrinos come from the decay of μ^{+} and μ^{-} beams in a storage ring. The far detector in this case is a 100 kt magnetized iron neutrino detector at a baseline of 2000 km. The third option is a Beta Beam, in which the neutrinos come from the decay of beta emitting isotopes, in particular ^{6}He and ^{18}Ne, also stored in a ring. The far detector is also the MEMPHYS detector in the Fréjus tunnel. EUROnu has undertaken conceptual designs of these facilities and studied the performance of the detectors. Based on this, it has determined the physics reach of each facility, in particular for the measurement of CP violation in the lepton sector, and estimated the cost of construction. These have demonstrated that the best facility to build is the Neutrino Factory. However, if a powerful proton driver is constructed for another purpose or if the MEMPHYS detector is built for astroparticle physics, the Super Beam also becomes very attractive.

  9. The Role of Moderate Static Magnetic Fields on Biomineralization of Osteoblasts on Sulfonated Polystryene Films

    Energy Technology Data Exchange (ETDEWEB)

    X Ba; M Hadjiargyrou; E DiMasi; Y Meng; M Simon; Z Tan; M Rafailovich

    2011-12-31

    We have investigated the effects of moderate static magnetic fields (SMFs) on murine MC3T3-E1 osteoblasts, and found that they enhance proliferations and promote differentiation. The increase in proliferation rates in response to SMFs was greater in cultures grown on partially sulfonated polytstyrene (SPS, degree of sulfonation: 33%) than in cultures grown on tissue culture plastic. We have previously shown that when the degree of sulfonation exceeded a critical value (12%) [1], spontaneous fibrillogenesis occured which allowed for direct observation of the ECM fibrillar organization under the influence of external fields. We found that the ECM produced in cultures grown on the SPS in the presence of the SMFs assembled into a lattice with larger dimensions than the ECM of the cultures grown in the absence of SMFs. During the early stages of the biomineralization process (day 7), the SMF exposed cultures also templated mineral deposition more rapidly than the control cultures. The rapid response is attributed to orientation of diamagnetic ECM proteins already present in the serum, which could then initiate further cellular signaling. SMFs also influenced late stage osteoblast differentiation as measured by the increased rate of osteocalcin secretion and gene expression beginning 15 days after SFM exposure. This correlated with a large increase in mineral deposition, and in cell modulus. GIXD and EDXS analysis confirmed early deposition of crystalline hydroxyapatite. Previous studies on the effects of moderate SMF had focused on cellular gene and protein expression, but did not consider the organization of the ECM fibers. Our ability to form these fibers has allowed us explore this additional effect and highlight its significance in the initiation of the biomineralization process.

  10. Contrast Induced by a Static Magnetic Field for Improved Detection in Nanodiamond Fluorescence Microscopy

    Science.gov (United States)

    Singam, Shashi K. R.; Motylewski, Jaroslaw; Monaco, Antonina; Gjorgievska, Elena; Bourgeois, Emilie; Nesládek, Milos; Giugliano, Michele; Goovaerts, Etienne

    2016-12-01

    Diamond nanoparticles with negatively charged nitrogen-vacancy (NV) centers are highly efficient nonblinking emitters that exhibit spin-dependent intensity. An attractive application of these emitters is background-free fluorescence microscopy exploiting the fluorescence quenching induced either by resonant microwaves (RMWs) or by an applied static magnetic field (SMF). Here, we compare RMW- and SMF-induced contrast measurements over a wide range of optical excitation rates for fluorescent nanodiamonds (FNDs) and for NV centers shallowly buried under the (100)-oriented surface of a diamond single crystal (SC). Contrast levels are found to be systematically lower in the FNDs than in the SC. At low excitation rates, the RMW contrast initially rises to a maximum (up to 7% in FNDs and 13% in the SC) but then decreases steadily at higher intensities. Conversely, the SMF contrast increases from approximately 12% at low excitation rates to high values of 20% and 38% for the FNDs and SC, respectively. These observations are well described in a rate-equations model for the charged NV defect using parameters in good agreement with the literature. The SMF approach yields higher induced contrast in image collection under commonly applied optical excitation. Unlike the RMW method, there is no thermal load exerted on the aqueous media in biological samples in the SMF approach. We demonstrate imaging by SMF-induced contrast in neuronal cultures incorporating FNDs (i) in a setup for patch-clamp experiments in parallel with differential-interference-contrast microscopy, (ii) after a commonly used staining procedure as an illustration of the high selectivity against background fluorescence, and (iii) in a confocal fluorescence microscope in combination with bright-field microscopy.

  11. Static synchronous compensator with superconducting magnetic energy storage for high power utility applications

    International Nuclear Information System (INIS)

    Molina, Marcelo G.; Mercado, Pedro E.; Watanabe, Edson H.

    2007-01-01

    Power systems security in the case of contingencies is ensured by maintaining adequate 'short-term generation reserve'. This reserve must be appropriately activated by means of the primary frequency control (PFC). Because the generation is an electro-mechanical process, the primary control reserve controllability is not as fast as required, especially by modern power systems. Since the new improvements achieved on the conventional control methods have not been enough to satisfy the high requirements established, the necessity of enhancing the performance of the PFC has arisen. At present, the new energy storage systems (ESS) are a feasible alternative to store excess energy for substituting for the primary control reserve. In this way, it is possible to combine this new ESS with power converter based flexible ac transmission systems (FACTS). This allows an effective exchange of active power with the electric grid and, thus, enhances the PFC. This paper presents an improved PFC scheme incorporating a static synchronous compensator (STATCOM) coupled with a superconducting magnetic energy storage (SMES) device. A detailed full model and a control algorithm based on a decoupled current control strategy of the enhanced compensator are proposed. The integrated STATCOM/SMES controller topology includes three level, multi-pulse, voltage source inverters (VSI) with phase control and incorporates a two quadrant, three level, dc-dc chopper as the interface between the STATCOM and the SMES coil. A novel three level control scheme is proposed by using concepts of instantaneous power in the synchronous rotating d-q reference frame. The dynamic performance of the presented control algorithms is evaluated through digital simulation performed by using SimPowerSystems of SIMULINK/MATLAB T M , and technical analysis is performed to obtain conclusions about the benefits of using SMES devices in the PFC of the electric system. Presently, a laboratory scale prototype device based on

  12. Potential scattering in the presence of a static magnetic field and a radiation field of arbitrary polarization

    Science.gov (United States)

    Ferrante, G.; Zarcone, M.; Nuzzo, S.; McDowell, M. R. C.

    1982-05-01

    Expressions are obtained for the total cross sections for scattering of a charged particle by a potential in the presence of a static uniform magnetic field and a radiation field of arbitrary polarization. For a Coulomb field this is closely related to the time reverse of photoionization of a neutral atom in a magnetic field, including multiphoton effects off-resonance. The model is not applicable when the radiation energy approaches one of the quasi-Landau state separations. The effects of radiation field polarization are examined in detail.

  13. Involvement of Na+/K+ pump in fine modulation of bursting activity of the snail Br neuron by 10 mT static magnetic field.

    Science.gov (United States)

    Nikolić, Ljiljana; Todorović, Nataša; Zakrzewska, Joanna; Stanić, Marina; Rauš, Snežana; Kalauzi, Aleksandar; Janać, Branka

    2012-07-01

    The spontaneously active Br neuron from the brain-subesophageal ganglion complex of the garden snail Helix pomatia rhythmically generates regular bursts of action potentials with quiescent intervals accompanied by slow oscillations of membrane potential. We examined the involvement of the Na(+)/K(+) pump in modulating its bursting activity by applying a static magnetic field. Whole snail brains and Br neuron were exposed to the 10-mT static magnetic field for 15 min. Biochemical data showed that Na(+)/K(+)-ATPase activity increased almost twofold after exposure of snail brains to the static magnetic field. Similarly, (31)P NMR data revealed a trend of increasing ATP consumption and increase in intracellular pH mediated by the Na(+)/H(+) exchanger in snail brains exposed to the static magnetic field. Importantly, current clamp recordings from the Br neuron confirmed the increase in activity of the Na(+)/K(+) pump after exposure to the static magnetic field, as the magnitude of ouabain's effect measured on the membrane resting potential, action potential, and interspike interval duration was higher in neurons exposed to the magnetic field. Metabolic pathways through which the magnetic field influenced the Na(+)/K(+) pump could involve phosphorylation and dephosphorylation, as blocking these processes abolished the effect of the static magnetic field.

  14. A morphometric study of bone surfaces and skin reactions after stimulation with static magnetic fields in rats

    Energy Technology Data Exchange (ETDEWEB)

    Linder-Aronson, S.; Lindskog, S. (Karolinska Institutet, Stockholm (Sweden))

    1991-01-01

    The present investigation was undertaken to measure any bone surface changes after stimulation with orthodontic magnets and, furthermore, to examine the soft tissue in immediate contact with the magnets. Both distal parts of the tibial hind legs in six groups of young rats were fitted with devices holding two orthodontic magnets in the experimental legs and similar devices without magnets in the control legs. The animals were killed after 2, 3, and 4 weeks. Morphometric evaluation showed significant increases in resorbing areas after 3 and 4 weeks. Similarly, a reduction was evident in the number of epithelial cells under the areas where the magnets had been applied. These findings indicate that the stimulation of bone resorption in the present study may have been caused by inhibition of the bone-lining osteoblasts. This proposition is supported by the apparent inhibitory effect of the magnetic fields on epithelial recycling that was seen as a reduced thickness of the epithelium under the magnets. Consequently, static magnetic fields should be used with care in orthodontic practice until a more complete understanding of their mechanism of action has been established.

  15. A morphometric study of bone surfaces and skin reactions after stimulation with static magnetic fields in rats.

    Science.gov (United States)

    Linder-Aronson, S; Lindskog, S

    1991-01-01

    The present investigation was undertaken to measure any bone surface changes after stimulation with orthodontic magnets and, furthermore, to examine the soft tissue in immediate contact with the magnets. Both distal parts of the tibial hind legs in six groups of young rats were fitted with devices holding two orthodontic magnets in the experimental legs and similar devices without magnets in the control legs. The animals were killed after 2, 3, and 4 weeks. Morphometric evaluation showed significant increases in resorbing areas after 3 and 4 weeks. Similarly, a reduction was evident in the number of epithelial cells under the areas where the magnets had been applied. These findings indicate that the stimulation of bone resorption in the present study may have been caused by inhibition of the bone-lining osteoblasts. This proposition is supported by the apparent inhibitory effect of the magnetic fields on epithelial recycling that was seen as a reduced thickness of the epithelium under the magnets. Consequently, static magnetic fields should be used with care in orthodontic practice until a more complete understanding of their mechanism of action has been established.

  16. The effect of low static magnetic field on osteogenic and adipogenic differentiation potential of human adipose stromal/stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Marędziak, Monika, E-mail: monika.maredziak@gmail.com [Faculty of Veterinary Medicine, University of Environmental and Life Sciences, Wrocław (Poland); Wroclaw Research Centre EIT+, Wrocław (Poland); Śmieszek, Agnieszka, E-mail: smieszek.agnieszka@gmail.com [Wroclaw Research Centre EIT+, Wrocław (Poland); Faculty of Biology, University of Environmental and Life Sciences, Wrocław (Poland); Tomaszewski, Krzysztof A., E-mail: krtomaszewski@gmail.com [Department of Anatomy, Jagiellonian University Medical College, Krakow (Poland); Lewandowski, Daniel, E-mail: daniel.lewandowski@pwr.wroc.pl [Institute of Materials Science and Applied Mechanics, Wroclaw University of Technology, Wroclaw (Poland); Marycz, Krzysztof, E-mail: krzysztofmarycz@interia.pl [Wroclaw Research Centre EIT+, Wrocław (Poland); Faculty of Biology, University of Environmental and Life Sciences, Wrocław (Poland)

    2016-01-15

    The aim of this work was to investigate the effects of static magnetic field (SMF) on the osteogenic properties of human adipose derived mesenchymal stem cells (hASCs). In this study in seven days viability assay we examined the impact of SMF on cells proliferation rate, population doubling time, and ability to form single-cell derived colonies. We have also examined cells' morphology, ultrastructure and osteogenic properties on the protein as well as mRNA level. We established a complex approach, which enabled us to obtain information about SMF and hASCs potential in the context of differentiation into osteogenic and adipogenic lineages. We demonstrated that SMF enhances both viability and osteogenic properties of hASCs through higher proliferation factor and shorter population doubling time. We have also observed asymmetrically positioned nuclei and organelles after SMF exposition. With regards to osteogenic properties we observed increased levels of osteogenic markers i.e. osteopontin, osteocalcin and increased ability to form osteonodules with positive reaction to Alizarin Red dye. We have also shown that SMF besides enhancing osteogenic properties of hASCs, simultaneously decreases their ability to differentiate into adipogenic lineage. Our results clearly show a direct influence of SMF on the osteogenic potential of hASCs. These results provide key insights into the role of SMF on their cellular fate and properties. - Graphical abstract: Influence of static magnetic field on viability and differentiation properties of human adipose derived mesenchymal stem cells. Abbreviations: SMF – static magnetic field; hASCs – human adipose derived mesenchymal stem cells; PF – proliferation factor; PDT – population doubling time; CFU-E –> colony forming unit efficiency; OPN – osteopontin; OCL – osteocalcin; Col – collagen type I; BMP-2 – bone morphogenetic protein 2; Ca – calcium; P – phosphorus. - Highlights: • Effects of static

  17. The effect of low static magnetic field on osteogenic and adipogenic differentiation potential of human adipose stromal/stem cells

    International Nuclear Information System (INIS)

    Marędziak, Monika; Śmieszek, Agnieszka; Tomaszewski, Krzysztof A.; Lewandowski, Daniel; Marycz, Krzysztof

    2016-01-01

    The aim of this work was to investigate the effects of static magnetic field (SMF) on the osteogenic properties of human adipose derived mesenchymal stem cells (hASCs). In this study in seven days viability assay we examined the impact of SMF on cells proliferation rate, population doubling time, and ability to form single-cell derived colonies. We have also examined cells' morphology, ultrastructure and osteogenic properties on the protein as well as mRNA level. We established a complex approach, which enabled us to obtain information about SMF and hASCs potential in the context of differentiation into osteogenic and adipogenic lineages. We demonstrated that SMF enhances both viability and osteogenic properties of hASCs through higher proliferation factor and shorter population doubling time. We have also observed asymmetrically positioned nuclei and organelles after SMF exposition. With regards to osteogenic properties we observed increased levels of osteogenic markers i.e. osteopontin, osteocalcin and increased ability to form osteonodules with positive reaction to Alizarin Red dye. We have also shown that SMF besides enhancing osteogenic properties of hASCs, simultaneously decreases their ability to differentiate into adipogenic lineage. Our results clearly show a direct influence of SMF on the osteogenic potential of hASCs. These results provide key insights into the role of SMF on their cellular fate and properties. - Graphical abstract: Influence of static magnetic field on viability and differentiation properties of human adipose derived mesenchymal stem cells. Abbreviations: SMF – static magnetic field; hASCs – human adipose derived mesenchymal stem cells; PF – proliferation factor; PDT – population doubling time; CFU-E –> colony forming unit efficiency; OPN – osteopontin; OCL – osteocalcin; Col – collagen type I; BMP-2 – bone morphogenetic protein 2; Ca – calcium; P – phosphorus. - Highlights: • Effects of static

  18. Diamagnetism of 2D-fermions in the strong nonhomogeneous static magnetic field B = B(0,0,1/cosh2(x-x0/δ))

    International Nuclear Information System (INIS)

    Hudak, O.

    1991-09-01

    We study diamagnetism of a gas of fermions moving in a nonhomogeneous magnetic field B = B(0,0,1/cosh 2 (x-x 0 /δ)). The gas magnetization, the static magnetic susceptibility, the chemical potential and the gas compressibility are discussed and compared with the uniform field case. (author). 5 refs

  19. Distinct Nature of Static and Dynamic Magnetic Stripes in Cuprate Superconductors

    Science.gov (United States)

    Jacobsen, H.; Holm, S. L.; Lǎcǎtuşu, M.-E.; Rømer, A. T.; Bertelsen, M.; Boehm, M.; Toft-Petersen, R.; Grivel, J.-C.; Emery, S. B.; Udby, L.; Wells, B. O.; Lefmann, K.

    2018-01-01

    We present detailed neutron scattering studies of the static and dynamic stripes in an optimally doped high-temperature superconductor, La2 CuO4 +y . We observe that the dynamic stripes do not disperse towards the static stripes in the limit of vanishing energy transfer. Therefore, the dynamic stripes observed in neutron scattering experiments are not the Goldstone modes associated with the broken symmetry of the simultaneously observed static stripes, and the signals originate from different domains in the sample. These observations support real-space electronic phase separation in the crystal, where the static stripes in one phase are pinned versions of the dynamic stripes in the other, having slightly different periods. Our results explain earlier observations of unusual dispersions in underdoped La2 -xSrx CuO4 (x =0.07 ) and La2 -xBax CuO4 (x =0.095 ).

  20. Quantification of synovistis by MRI: correlation between dynamic and static gadolinium-enhanced magnetic resonance imaging and microscopic and macroscopic signs of synovial inflammation

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Stoltenberg, M; Løvgreen-Nielsen, P

    1998-01-01

    Dynamic and static gadolinium-diethylenetriaminepentaacetic acid(Gd-DTPA)-enhanced magnetic resonance imaging (MRI) were evaluated as measures of joint inflammation in arthritis, by a comparison with macroscopic and microscopic signs of synovitis. Furthermore, the importance of the size...

  1. Effects of static magnetic field exposure on hematological and biochemical parameters in rats

    Directory of Open Access Journals (Sweden)

    Salem Amara

    2006-11-01

    Full Text Available The present work was undertaken in order to investigate the effects of static magnetic field (SMF on growth rates, hematopoiesis, plasmatic proteins levels, glucose concentration, lactate dehydrogenase (LDH and transaminases activities in male rats. Sub-acute exposure of rats during 5 consecutive days to SMF (1h/day at 128mT induced an increase of plasma LDH activity (+38%, pEste estudo foi realizado com o obejtivo de investigar os efeitos do campo magnético estático (CMS nas taxas de crescimento, hematopoiese, concentrações de proteínas plasmáticas, glicemia, da desidrogenase lática (DHL e transaminases (alanina aminotransferase-ALT e aspartato aminotransferase-AST em ratos machos. Após exposição de modo sub-agudo durante 5 dias consecutivos ao CMS (1 hora/dia, a 128mT, houve aumento em 38% na concentração de DHL (p<0.05, porém não houve mudanças nos índices hematimétricos, nas proteínas plasmáticas e nas transaminases. Duas semans após exposição ao CMS durante 30 dias consecutivos (CMS (1 hora/dia, a 128mT houve diminuição significativa das taxas de crescimento e aumento significativo das concetrações de proteínas (+62%, p<0.05, da hemoglobina (+10%, p<0.05, eritrócitos (+7%, p<0.05, leucócitos (+17%, p<0.05 e plaquetas (+10%, p<0.05. A exposição sub-crônica ao CMS induziu aumento da DHL (+43%, p<0.05, AST (+ 41%, p<0.05 e ALT (+95%, p<0.05. Em contraste não houve aumento da glicemia. Estas alterações sugerem que a exposição ao CMS possivelmente influencia a proliferação de células do sistema hematopoiético e a produção enzimática, indicando alterações teciduais.

  2. Influence of oxygen disordering on static magnetic susceptibility of YBa2Cu3O7-x ceramics

    International Nuclear Information System (INIS)

    Sokolov, B.Yu.; Vil'danov, R.R.

    2008-01-01

    Influence of disordering of the populated oxygen positions in YBa 2 Cu 3 O 7-x ceramic's structure on its static magnetic susceptibility in the range of temperatures T>Tc is investigated. For occurrence of disordering the initial ceramics YBa 2 Cu 3 O 6,9 was annealed at T=520 C with the subsequent quenching in liquid nitrogen. Evolutions of a magnetic susceptibility and resistance of annealed ceramics during its air storage at a room temperature were studied. It is revealed that, unlike the initial optimum doped ceramics, annealed samples have appreciable temperature dependence of a magnetic susceptibility. Interpretation of results is executed on the basis of model of electronic phase separation and occurrence of a pseudo gap in a energy spectrum of free carriers of a superconductor. (authors)

  3. Investigation of Demagnetization Effect in an Interior V-Shaped Magnet Synchronous Motor at Dynamic and Static Conditions

    Directory of Open Access Journals (Sweden)

    F. Mahmouditabar

    2018-03-01

    Full Text Available Permanent magnet motors have been considered for a variety of applications due to their features such as high power density and high efficiency. One of the issues that should be investigated in the design of these motors is the demagnetization problem. Usually, the demagnetization analysis is carried out in a steady state, while demagnetization effect in dynamic condition is more considerable due to pulse shaped of armature field. Based on this fact, in this paper, dynamic demagnetization is investigated for an IPM V‑shaped magnet. This study has been done for two types of magnet, each one in static & dynamic conditions and the results are compared. Moreover, the effect of flux weakening regime on demagnetization is investigated.

  4. A polarisation modulation scheme for measuring vacuum magnetic birefringence with static fields

    Energy Technology Data Exchange (ETDEWEB)

    Zavattini, G.; Ejlli, A. [Universita di Ferrara, Dipt. di Fisica e Scienze della Terra (Italy); INFN, Sezione di Ferrara (Italy); Della Valle, F. [Universita di Trieste, Dipt. di Fisica, Trieste (Italy); INFN, Sezione di Trieste, TS (Italy); Ruoso, G. [INFN, Lab. Nazionali di Legnaro (Italy)

    2016-05-15

    A novel polarisation modulation scheme for polarimeters based on Fabry-Perot cavities is presented. The application to the measurement of the magnetic birefringence of vacuum with the HERA superconducting magnets in the ALPS-II configuration is discussed. (orig.)

  5. Exposure to static magnetic field stimulates quorum sensing circuit in luminescent Vibrio strains of the Harveyi clade.

    Directory of Open Access Journals (Sweden)

    Adelfia Talà

    Full Text Available In this study, the evidence of electron-dense magnetic inclusions with polyhedral shape in the cytoplasm of Harveyi clade Vibrio strain PS1, a bioluminescent bacterium living in symbiosis with marine organisms, led us to investigate the behavior of this bacterium under exposure to static magnetic fields ranging between 20 and 2000 Gauss. When compared to sham-exposed, the light emission of magnetic field-exposed bacteria growing on solid medium at 18°C ±0.1°C was increased up to two-fold as a function of dose and growth phase. Stimulation of bioluminescence by magnetic field was more pronounced during the post-exponential growth and stationary phase, and was lost when bacteria were grown in the presence of the iron chelator deferoxamine, which caused disassembly of the magnetic inclusions suggesting their involvement in magnetic response. As in luminescent Vibrio spp. bioluminescence is regulated by quorum sensing, possible effects of magnetic field exposure on quorum sensing were investigated. Measurement of mRNA levels by reverse transcriptase real time-PCR demonstrated that luxR regulatory gene and luxCDABE operon coding for luciferase and fatty acid reductase complex were significantly up-regulated in magnetic field-exposed bacteria. In contrast, genes coding for a type III secretion system, whose expression was negatively affected by LuxR, were down-regulated. Up-regulation of luxR paralleled with down-regulation of small RNAs that mediate destabilization of luxR mRNA in quorum sensing signaling pathways. The results of experiments with the well-studied Vibrio campbellii strain BB120 (originally classified as Vibrio harveyi and derivative mutants unable to synthesize autoinducers suggest that the effects of magnetic fields on quorum sensing may be mediated by AI-2, the interspecies quorum sensing signal molecule.

  6. Alteration of the ground state by external magnetic fields. [External field, coupling constant ratio, static tree level approximation

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, B J; Shepard, H K [New Hampshire Univ., Durham (USA). Dept. of Physics

    1976-03-22

    By fully exploiting the mathematical and physical analogy to the Ginzburg-Landau theory of superconductivity, a complete discussion of the ground state behavior of the four-dimensional Abelian Higgs model in the static tree level approximation is presented. It is shown that a sufficiently strong external magnetic field can alter the ground state of the theory by restoring a spontaneously broken symmetry, or by creating a qualitatively different 'vortex' state. The energetically favored ground state is explicitly determined as a function of the external field and the ratio between coupling constants of the theory.

  7. Calculation of the resonance frequency change for a cavity charged by a plasma with or without a static magnetic field

    International Nuclear Information System (INIS)

    Melin, G.

    1967-03-01

    In the mere case of a cold plasma with or without static magnetic field, are given two methods of calculation of resonance frequency shift and absorption in a cylindrical cavity crossed by a plasma column: 1. A perturbation method, already known and used for electronic density measurements is restated and its application is used for several high frequency cavity modes. 2. An exact method employing Maxwell's equations, which however necessitates a computer, is compared with the first one; it permits a determination of the validity limits of the perturbation method and to draw conclusions, [fr

  8. Toward Monte Carlo simulation of general cases of static muon spin relaxation in disordered magnetic materials: long-range magnetic order in alloys

    International Nuclear Information System (INIS)

    Noakes, D.R.

    2001-01-01

    Monte Carlo simulations of zero-field (ZF) muon spin relaxation (μSR) functions generated by long-range-ordered states with disorder are presented, for the completely static limit. Understanding of this is necessary before Monte Carlo simulation of the effect of short-range magnetic ordering on μSR in spin glasses can begin. Alloy disorder, controlled by the magnetic ion concentration parameter f m , and partial ordering of each moment, controlled by the order parameter f o , are considered. Qualitatively different behavior is seen depending on whether the dense moment, perfect-order limit ( f m =1, f o =1) field at the muon site is non-zero, or cancels (as can happen in high-symmetry materials). Around the edges of the two-dimensional ( f m ,f o ) parameter space, four limit cases with qualitatively different behavior are identified: (A) f o →0, the random frozen spin glass for arbitrary magnetic ion concentration; (B) f o →1, nearly perfect magnetic ordering in a alloy of arbitrary magnetic ion concentration; (C) f m →0, magnetic order developing (as f o increases) in a dilute magnetic alloy; (D) f m →1, magnetic order developing (as f o increases) in a dense magnetic material. Case A was discussed in a previous publication. The results for case D answer the question of how the Gaussian Kubo-Toyabe relaxation function for perfect disorder develops into an oscillating function as magnetic order develops in a material. Case C indicates that the effects of magnetic ordering in the dilute moment limit produce only subtle effects in ZF-μSR spectra that would be difficult to unambiguously identify as due to ordering in a real-world experiment. Case B generates complicated multi-frequency behavior

  9. Feasibility study of determining axial stress in ferromagnetic bars using reciprocal amplitude of initial differential susceptibility obtained from static magnetization by permanent magnets

    Science.gov (United States)

    Deng, Dongge; Wu, Xinjun

    2018-03-01

    An electromagnetic method for determining axial stress in ferromagnetic bars is proposed. In this method, the tested bar is under the static magnetization provided by permanent magnets. The tested bar do not have to be magnetized up to the technical saturation because reciprocal amplitude of initial differential susceptibility (RAIDS) is adopted as the feature parameter. RAIDS is calculated from the radial magnetic flux density Br Lo = 0.5 at the Lift-off Lo = 0.5 mm, radial magnetic flux density Br Lo = 1 at the Lift-off Lo = 1 mm and axial magnetic flux density Bz Lo = 1 at the Lift-off Lo = 1 mm from the surface of the tested bar. Firstly, the theoretical derivation of RAIDS is carried out according to Gauss' law for magnetism, Ampere's Law and the Rayleigh relation in Rayleigh region. Secondly, the experimental system is set up for a 2-meter length and 20 mm diameter steel bar. Thirdly, an experiment is carried out on the steel bar to analyze the relationship between the obtained RAIDS and the axial stress. Experimental results show that the obtained RAIDS decreases almost linearly with the increment of the axial stress inside the steel bar in the initial elastic region. The proposed method has the potential to determine tensile axial stress in the slender cylindrical ferromagnetic bar.

  10. The effect of static and pulsating magnetic field on immunocompetent cells in blood of hematological patients in nitro

    International Nuclear Information System (INIS)

    Bessmel'tsev, S.S.; Abdulkadyrov, K.M.; Gonchar, V.A.; Lavrushina, T.S.

    2001-01-01

    Immunological characteristics were studied in 103 patients with multiple myeloma, acute leukemia, chronic lymphocytic leukemia and non-Hodgkin's disease following in vitro exposure of blood to a low-intensity static field (SF) and alternating field (AF) or pulse magnetic field (PF). In a SF-AF study of multiple myeloma, a 30 min exposure had a positive effect on expression of tumor cells and T-cell markers and stimulated the regulatory function of T-lymphocytes. In acute leukemia, a combined application of the magnetic fields had an effect on the helper activity of the T-lymphocyte subpopulation. The phagocyte activity of leukocytes increased significantly while their digestive ability rose to a moderate degree [ru

  11. Bose-Einstein condensation in a general static homogeneous magnetic fieldinebreak and the effective action: The nonrelativistic ideal gas

    International Nuclear Information System (INIS)

    Toms, D.J.

    1995-01-01

    We consider the problem of Bose-Einstein condensation for a system of nonrelativistic spin-0 bosons in a space of arbitrary dimension D. A general static homogeneous magnetic field is imposed. The effective action approach and ζ-function regularization are used. If D=2δ or 2δ+1, a constant magnetic field is characterized by δ independent components. If p≤δ of these components are nonzero, the condition for Bose-Einstein condensation to occur is D-2p≥3. This means that if D=2δ, then Bose-Einstein condensation never occurs for p=δ-1 or δ. If D=2δ+1, Bose-Einstein condensation never occurs for p=δ. For D-2p≥3, Bose-Einstein condensation does occur, and we show how it may be interpreted as symmetry breaking to give a ground state which is not constant

  12. One-loop QCD thermodynamics in a strong homogeneous and static magnetic field

    Science.gov (United States)

    Rath, Shubhalaxmi; Patra, Binoy Krishna

    2017-12-01

    We have studied how the equation of state of thermal QCD with two light flavors is modified in a strong magnetic field. We calculate the thermodynamic observables of hot QCD matter up to one-loop, where the magnetic field affects mainly the quark contribution and the gluon part is largely unaffected except for the softening of the screening mass. We have first calculated the pressure of a thermal QCD medium in a strong magnetic field, where the pressure at fixed temperature increases with the magnetic field faster than the increase with the temperature at constant magnetic field. This can be understood from the dominant scale of thermal medium in the strong magnetic field, being the magnetic field, in the same way that the temperature dominates in a thermal medium in the absence of magnetic field. Thus although the presence of a strong magnetic field makes the pressure of hot QCD medium larger, the dependence of pressure on the temperature becomes less steep. Consistent with the above observations, the entropy density is found to decrease with the temperature in the presence of a strong magnetic field which is again consistent with the fact that the strong magnetic field restricts the dynamics of quarks to two dimensions, hence the phase space becomes squeezed resulting in the reduction of number of microstates. Moreover the energy density is seen to decrease and the speed of sound of thermal QCD medium increases in the presence of a strong magnetic field. These findings could have phenomenological implications in heavy ion collisions because the expansion dynamics of the medium produced in non-central ultra-relativistic heavy ion collisions is effectively controlled by both the energy density and the speed of sound.

  13. Applied magnetic field angle dependence of the static and dynamic magnetic properties in FeCo films during the deposition

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Derang; Zhu, Zengtai; Feng, Hongmei; Pan, Lining; Cheng, Xiaohong; Wang, Zhenkun [Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Wang, Jianbo [Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Special Function Materials and Structure Design, Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Liu, Qingfang, E-mail: liuqf@lzu.edu.cn [Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China)

    2016-10-15

    FeCo films were prepared by a simple and convenient electrodeposition method. An external magnetic field was applied to the film to induce magnetic anisotropy during deposition. Comparing with the previous work, the angle between the direction of applied magnetic field and film plane is changed from in-plane to out-plane. The influence of the applied magnetic field on magnetic properties was investigated. As a result, it can be found that the in-plane anisotropy is driven by the in-plane component of the magnetic field applied during growth. In addition, the result can also be confirmed by the dynamic magnetic anisotropy of the film obtained by vector network analyzer ferromagnetic resonance technique. - Highlights: • FeCo films were prepared by electrodeposition method. • An external magnetic field was applied to induce anisotropy during deposition. • The direction of applied magnetic field is changed from in-plane to out-plane. • The magnetic properties of films were investigated by vector network analyzer. • The in-plane anisotropy is driven by the in-plane component of the field.

  14. Very high intensity reaction chamber design

    International Nuclear Information System (INIS)

    Devaney, J.J.

    1975-09-01

    The problem of achieving very high intensity irradiation by light in minimal regions was studied. Three types of irradiation chamber are suggested: the common laser-reaction chamber, the folded concentric or near-concentric resonator, and the asymmetric confocal resonator. In all designs the ratio of high-intensity illuminated volume to other volume is highly dependent (to the 3 / 2 power) on the power and fluence tolerances of optical elements, primarily mirrors. Optimization of energy coupling is discussed for the common cavity. For the concentric cavities, optimization for both coherent and incoherent beams is treated. Formulae and numerical examples give the size of chambers, aspect ratios, maximum pass number, image sizes, fluences, and the like. Similarly for the asymmetric confocal chamber, formulae and numerical examples for fluences, dimensions, losses, and totally contained pass numbers are given

  15. Development of high intensity proton accelerator

    International Nuclear Information System (INIS)

    Mizumoto, M.; Kusano, J.; Hasegawa, K.; Ouchi, N.; Oguri, H.; Kinsho, M.; Touchi, Y.; Honda, Y.; Mukugi, K.; Ino, H.; Noda, F.; Akaoka, N.; Kaneko, H.; Chishiro, E.; Fechner, B.

    1997-01-01

    The high-intensity proton linear accelerator with an energy of 1.5 GeV and an average current of 5.33mA has been proposed for the Neutron Science Project (NSP) at JAERI. the NSP is aiming at exploring nuclear technologies for nuclear waste transmutation based on a proton induced spallation neutrons. The proposed accelerators facilities will be also used in the various basic research fields such as condensed matter physics in combination with a high intensity proton storage ring. The R and D work has been carried out for the components of the front-end of the proton accelerator. For the high energy portion above 100 MeV, superconducting (SC) accelerator linac has been designed and developed as a major option. (Author) 7 refs

  16. theoretical and experimental study of plasma acceleration by means of R.F. and static magnetic field gradient

    International Nuclear Information System (INIS)

    Bardet, Rene; Consoli, Terenzio; Geller, Richard

    1964-09-01

    In the first part of the paper, the theory of the physical mechanism of ion dragging by accelerated electrons due to the superimposition of the gradient of a electromagnetic field and the gradient of a static magnetic field, is described. The resulting trajectory of the electrons is a helicoid and one shows the variations of the diameter and the path of the spirals along the axis as a function of the difference between the gyrofrequency and the applied R.F. frequency. The ion acceleration is due to an electron space charge effect. The grouping of the equations of the electronic and ionic fluid motions leads to the introduction of a tensor mass: along the x and y direction the transverse motion of the fluid is controlled by the relativistic mass of electrons whereas along the z direction the axial motion is determined by the ionic mass. Then we deduce physical consequences of the theoretical study and give three experimental evidences. The second part of the paper is devoted to the experimental device called Pleiade which allowed us to verify some of the theoretical predictions. Pleiade produces a D.C. operating plasma beam in which the electrons exhibit radially oriented energies whereas the ionic energy is mainly axial. The experimental results indicate that the energy of the particles is in the keV range. In the third part we deal with the reflecting properties of the device. We show that the R.F. static magnetic field gradients are not only capable of accelerating a Plasma beam along the axially decreasing magnetic field, but are also capable of stopping and reflecting such a beam when the latter is moving along an axially increasing magnetic field. We describe finally a plasma accumulation experiment in which two symmetric structures form simultaneously an accelerator and a 'dynamic mirror' for the particles. Evidence of accumulation is given. (authors) [fr

  17. Toward real-time temperature monitoring in fat and aqueous tissue during magnetic resonance-guided high-intensity focused ultrasound using a three-dimensional proton resonance frequency T1 method.

    Science.gov (United States)

    Diakite, Mahamadou; Odéen, Henrik; Todd, Nick; Payne, Allison; Parker, Dennis L

    2014-07-01

    To present a three-dimensional (3D) segmented echoplanar imaging (EPI) pulse sequence implementation that provides simultaneously the proton resonance frequency shift temperature of aqueous tissue and the longitudinal relaxation time (T1 ) of fat during thermal ablation. The hybrid sequence was implemented by combining a 3D segmented flyback EPI sequence, the extended two-point Dixon fat and water separation, and the double flip angle T1 mapping techniques. High-intensity focused ultrasound (HIFU) heating experiments were performed at three different acoustic powers on excised human breast fat embedded in ex vivo porcine muscle. Furthermore, T1 calibrations with temperature in four different excised breast fat samples were performed, yielding an estimate of the average and variation of dT1 /dT across subjects. The water only images were used to mask the complex original data before computing the proton resonance frequency shift. T1 values were calculated from the fat-only images. The relative temperature coefficients were found in five fat tissue samples from different patients and ranged from 1.2% to 2.6%/°C. The results demonstrate the capability of real-time simultaneous temperature mapping in aqueous tissue and T1 mapping in fat during HIFU ablation, providing a potential tool for treatment monitoring in organs with large fat content, such as the breast. Copyright © 2013 Wiley Periodicals, Inc.

  18. Abatement of segregation with the electro and static magnetic field during twin-roll casting of 7075 alloy sheet

    Energy Technology Data Exchange (ETDEWEB)

    Su, X. [The Key Laboratory of Electromagnetic Processing of Material, Ministry of Education, 317#, Northeastern University, Shenyang, 110819 Liaoning (China); Xu, G.M., E-mail: Xu_gm@epm.neu.edu.cn [The Key Laboratory of Electromagnetic Processing of Material, Ministry of Education, 317#, Northeastern University, Shenyang, 110819 Liaoning (China); Jiang, D.H. [Donggong Information Science and Technology Co., Ltd., Guangzhou, 510000 Guangdong (China)

    2014-04-01

    This study aims to investigate the influence of electromagnetic field on the distribution and composition of precipitates and on the mechanical properties of 7075 rolled sheets. The non-field and field microstructure and the mechanical properties were studied in detail by optical microscope (OM), electron probe microanalyzer (EPMA), multiple sample tensile as well as hardness tests. The Fine and equiaxed grains were obtained when introducing the alternating oscillating electromagnetic field to the twin-roll casting (TRC) process with 0.13 T static magnetic and 386 A alternating current (AC) intensities. Due to a damping effect on the convection generated by applying the electro- and static magnetic fields, the undercooling of the melt decreases and the continuous net-like precipitates are refined and broken remarkably. Especially under oscillating electromagnetic field conditions, the best uniform microstructure without mottled segregation was obtained. In addition, the fields can effectively enhance solute mixing capacity and reduce heat discharge, resulting in the increase of mechanical properties of 7075 sheets in both the longitudinal and long transverse directions. The optimum process in the present study, in which the higher solid solubility in Al matrix and the stronger hardness as well as tensile strength was gained as compared to other rolled specimens, is considered as alternating oscillating TRC process.

  19. J-substitution algorithm in magnetic resonance electrical impedance tomography (MREIT): phantom experiments for static resistivity images.

    Science.gov (United States)

    Khang, Hyun Soo; Lee, Byung Il; Oh, Suk Hoon; Woo, Eung Je; Lee, Soo Yeol; Cho, Min Hyoung; Kwon, Ohin; Yoon, Jeong Rock; Seo, Jin Keun

    2002-06-01

    Recently, a new static resistivity image reconstruction algorithm is proposed utilizing internal current density data obtained by magnetic resonance current density imaging technique. This new imaging method is called magnetic resonance electrical impedance tomography (MREIT). The derivation and performance of J-substitution algorithm in MREIT have been reported as a new accurate and high-resolution static impedance imaging technique via computer simulation methods. In this paper, we present experimental procedures, denoising techniques, and image reconstructions using a 0.3-tesla (T) experimental MREIT system and saline phantoms. MREIT using J-substitution algorithm effectively utilizes the internal current density information resolving the problem inherent in a conventional EIT, that is, the low sensitivity of boundary measurements to any changes of internal tissue resistivity values. Resistivity images of saline phantoms show an accuracy of 6.8%-47.2% and spatial resolution of 64 x 64. Both of them can be significantly improved by using an MRI system with a better signal-to-noise ratio.

  20. Life table analysis of the performance of aphid Sitobion avenae (Homoptera: Aphididae nymphs exposed to a static magnetic field

    Directory of Open Access Journals (Sweden)

    He Juan

    2013-01-01

    Full Text Available Using the age-stage two-sex life table, this work was undertaken in order to determine the effect of static magnetic fields (SMFs at two flux densities (0.176T and 0.065T applied at increasing times of duration (0.25, 0.5, 1 and 2 h on the development, fecundity and reproduction of the aphid, Sitobion avenae. Exposed nymphs had a statistically significant shortened first instar period and adult longevity and prolonged fourth instar periods compared to controls. There were significant differences in the population parameters for two exposure combinations, 0.176T for 0.5 h and 0.065T for 1 h. The intrinsic rate of increase (r, net reproductive rate (R0 and mean generation time (T were 0.1165, 3.5 and 11.7 days, respectively, 0.176 T for 0.5 h and -0.0198, 0.7 and 11.8 days, respectively, 0.065T for 1 h. We therefore recommend using the age-stage, two-sex life table to study the effect of the static magnetic field on development and growth of the aphid, Sitobion avenae.

  1. Influence of End-Effects on Static Torque Performance of Misaligned Cylindrical Permanent Magnet Couplings

    DEFF Research Database (Denmark)

    Högberg, Stig; Hansen, Hilary; Jensen, Bogi Bech

    2014-01-01

    Permanent magnet couplings are widely used in applications requiring torque to be transmitted through an air- gap. The aim of this study is to observe and explain the effect of radial and axial misalignment in a 12-pole, cylindrical permanent magnet coupling. Pull-out torque was measured for two...

  2. Yeast cells proliferation on various strong static magnetic fields and temperatures

    International Nuclear Information System (INIS)

    Otabe, E S; Kuroki, S; Nikawa, J; Matsumoto, Y; Ooba, T; Kiso, K; Hayashi, H

    2009-01-01

    The effect of strong magnetic fields on activities of yeast cells were investigated. Experimental yeast cells were cultured in 5 ml of YPD(Yeast extract Peptone Dextrose) for the number density of yeast cells of 5.0 ±0.2 x 10 6 /ml with various temperatures and magnetic fields up to 10 T. Since the yeast cells were placed in the center of the superconducting magnet, the effect of magnetic force due to the diamagnetism and magnetic gradient was negligibly small. The yeast suspension was opened to air and cultured in shaking condition. The number of yeast cells in the yeast suspension was counted by a counting plate with an optical microscope, and the time dependence of the number density of yeast cells was measured. The time dependence of the number density of yeast cells, ρ, of initial part is analyzed in terms of Malthus equation as given by ρ = ρo exp(kt), where k is the growth coefficient. It is found that, the growth coefficient under the magnetic field is suppressed compared with the control. The growth coefficient decreasing as increasing magnetic field and is saturated at about 5 T. On the other hand, it is found that the suppression of growth of yeast cells by the magnetic field is diminished at high temperatures.

  3. Heavy quark potential in a static and strong homogeneous magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Mujeeb; Chatterjee, Bhaswar; Patra, Binoy Krishna [Indian Institute of Technology Roorkee, Department of Physics, Roorkee (India)

    2017-11-15

    We have investigated the properties of quarkonia in a thermal QCD medium in the background of strong magnetic field. For that purpose, we employ the Schwinger proper-time quark propagator in the lowest Landau level to calculate the one-loop gluon self-energy, which in the sequel gives the effective gluon propagator. As an artifact of strong magnetic field approximation (eB >> T{sup 2} and eB >> m{sup 2}), the Debye mass for massless flavors is found to depend only on the magnetic field which is the dominant scale in comparison to the scales prevalent in the thermal medium. However, for physical quark masses, it depends on both magnetic field and temperature in a low temperature and high magnetic field but the temperature dependence is very meager and becomes independent of the temperature beyond a certain temperature and magnetic field. With the above mentioned ingredients, the potential between heavy quark (Q) and anti-quark (anti Q) is obtained in a hot QCD medium in the presence of a strong magnetic field by correcting both short- and long-range components of the potential in the real-time formalism. It is found that the long-range part of the quarkonium potential is affected much more by magnetic field as compared to the short-range part. This observation facilitates us to estimate the magnetic field beyond which the potential will be too weak to bind Q anti Q together. For example, the J/ψ is dissociated at eB ∝ 10 m{sub π}{sup 2} and Υ is dissociated at eB ∝ 100 m{sub π}{sup 2} whereas its excited states, ψ{sup '} and Υ{sup '} are dissociated at smaller magnetic field eB = m{sub π}{sup 2}, 13 m{sub π}{sup 2}, respectively. (orig.)

  4. Excellent improvement in the static and dynamic magnetic properties of carbon coated iron nanoparticles for microwave absorption

    Energy Technology Data Exchange (ETDEWEB)

    Khani, Omid, E-mail: omidkhani@mut-es.ac.ir; Shoushtari, Morteza Zargar; Farbod, Mansoor

    2015-11-15

    Carbon coated iron nanoparticles were synthesized, using a simple arc-discharge method. The morphology and the internal structure of the core/shell nanoparticles were studied, using field emission scanning electron microscopy and transmission electron microscopy. X-ray diffraction analysis showed that both magnetic α-Fe and nonmagnetic γ-Fe phases existed in the as-prepared particles. In order to improve the static and dynamic magnetic properties of the core/shell nanoparticles, the produced nanocapsules were annealed in argon atmosphere at two different temperatures. Hysteresis loops revealed that the value of the saturation magnetization (M{sub S}) increased more than 4.1 times of its original value by annealing and this led to 70% increase in the imaginary part of the permeability. Phase analysis showed that heat treatment eliminated the nonmagnetic γ-Fe phase completely. The reflection loss plots were studied for composite layers containing 20 vol% of the annealed and not annealed nanocapsules. One of the absorber layers which contained annealed nanocapsules showed at least −10 dB loss in the whole G, C, X and Ku frequency bands and the optimal absorption exceeded −37 dB at 5.8 GHz for the as-prepared sample with a thickness of 3.2 mm. The results revealed that the magnetic properties of the arc-made Fe/C core/shell nanoparticle can be improved significantly by annealing in argon.

  5. Static properties and spin dynamics of the ferromagnetic spin-1 Bose gas in a magnetic field

    International Nuclear Information System (INIS)

    Kis-Szabo, Krisztian; Szepfalusy, Peter; Szirmai, Gergely

    2005-01-01

    The properties of spin-1 Bose gases with ferromagnetic interactions in the presence of a nonzero magnetic field are studied. The equation of state and thermodynamic quantities are worked out with the help of a mean-field approximation. The phase diagram besides Bose-Einstein condensation contains a first-order transition where two values of the magnetization coexist. The dynamics is investigated with the help of the random phase approximation. The soft mode corresponding to the critical point of the magnetic phase transition is found to behave like in conventional theory

  6. Static magnetic therapy does not decrease pain or opioid requirements: a randomized double-blind trial.

    Science.gov (United States)

    Cepeda, M Soledad; Carr, Daniel B; Sarquis, Tony; Miranda, Nelcy; Garcia, Ricardo J; Zarate, Camilo

    2007-02-01

    A growing multibillion dollar industry markets magnetic necklaces, bracelets, bands, insoles, back braces, mattresses, etc., for pain relief, although there is little evidence for their efficacy. We sought to evaluate the effect of magnetic therapy on pain intensity and opioid requirements in patients with postoperative pain. We designed a randomized, double-blind, controlled trial. One-hundred-sixty-five patients older than 12 yr of age were randomized to magnetic (n = 81) or sham therapy (n = 84) upon reporting moderate-to-severe pain in the postanesthesia care unit. Devices were placed over the surgical incision and left in place for 2 h. Patients rated their pain intensity on a 0-10 scale every 10 min and received incremental doses of morphine until pain intensity was Magnetic therapy lacks efficacy in controlling acute postoperative pain intensity levels or opioid requirements and should not be recommended for pain relief in this setting.

  7. Imaging the Statics and Dynamics of Superconducting Vortices and Antivortices Induced by Magnetic Microdisks

    Directory of Open Access Journals (Sweden)

    R. B. G. Kramer

    2011-10-01

    Full Text Available If a magnet of microscopic dimensions is brought in close proximity to a superconductor, the quantized nature of their interaction due to the creation of flux quanta in the superconducting system becomes noticeable. Herein, we directly image, via scanning Hall microscopy, the vortex-antivortex pairs in a superconducting film created by micromagnets. The number of antivortices at equilibrium conditions can be changed either by tuning the magnetic moment of the magnets or by annihilation with externally induced vortices. We demonstrate that small ac field excitations shake the antivortices sitting next to the micromagnets whereas no sizable motion is observed for the vortices sitting on top of the magnets, clearly revealing the different mobility of these two vortex species. A metastable state, which is obtained by applying a field after the system has been cooled down below the superconducting transition, shows a complex graded distribution of coexisting vortices and antivortices forming an intertwined critical state.

  8. Total antioxidant capacity, total oxidant status and oxidative stress index in the men exposed to 1.5 T static magnetic field.

    Science.gov (United States)

    Sirmatel, O; Sert, C; Sirmatel, F; Selek, S; Yokus, B

    2007-06-01

    The aim of this study was to investigate the effects of a high-strength magnetic field produced by a magnetic resonance imaging (MRI) apparatus on oxidative stress. The effects of a 1.5 T static magnetic field on the total antioxidant capacity (TAC), total oxidant status (TOS) and oxidative stress index (OSI) in male subjects were investigated. In this study, 33 male volunteers were exposed to a 1.5 T static magnetic field for a short time and the TAC, TOS and OSI of each subject were determined. Magnetic field exposure was provided using a magnetic resonance apparatus; radiofrequency was not applied. Blood samples were taken from subjects and TAC, TOS and OSI values were measured using the methods of Erel. TAC showed a significant increase in post-exposures compared to pre-exposures to the magnetic field (p < 0.05). OSI and TOS showed a significant decrease in post-exposures compared to pre-exposures to a 1.5 T magnetic field (for each of two, p < 0.01). The 1.5 T static magnetic field used in the MRI apparatus did not yield a negative effect; on the contrary, it produced the positive effect of decreasing oxidative stress in men following short-term exposure.

  9. Development of a high intensity proton accelerator

    International Nuclear Information System (INIS)

    Mizumoto, Motoharu; Kusano, Joichi; Hasegawa, Kazuo; Ito, Nobuo; Oguri, Hidetomo; Touchi, Yutaka; Mukugi, Ken; Ino, Hiroshi

    1997-01-01

    The high-intensity proton linear accelerator with a beam power of 15 MW has been proposed for various engineering tests for the nuclear waste transmutation system as one of the research plans in the Neutron Science Research Program (NSRP) in JAERI. High intensity proton beam and secondary particle beams such as neutron, pion, muon and unstable radio isotope (RI) beam generated from the proton spallation reaction will be utilized at these facilities in each research field. The R and D work has been carried out for the components of the front-end part of the proton accelerator; ion source, RFQ, DTL and RF source. In the beam test, the current of 70 mA with a duty factor of 7% has been accelerated from the RFQ at the energy of 2 MeV. A hot test model of the DTL for the high power and high duty operation was fabricated and tested. For the high energy portion above 100 MeV, superconducting accelerating cavity is studied as a main option. The superconducting linac is expected to have several favourable characteristics for high intensity accelerator such as short accelerator length, large bore radius resulting in low beam losses and cost effectiveness for construction and operation. A test stand with equipment of cryogenics system, vacuum system, RF system and cavity processing and cleaning is prepared to test the physics issues and fabrication process. The proposed plan for accelerator design and construction will compose of two consecutive stages. The first stage will be completed in about 7 years with the beam power of 1.5 MW. As the second stage gradual upgrading of the beam power will be made up to 15 MW. 7 refs., 3 figs., 4 tabs

  10. Moderate and high intensity pulsed electric fields

    OpenAIRE

    Timmermans, Rian Adriana Hendrika

    2018-01-01

    Pulsed Electric Field (PEF) processing has gained a lot of interest the last decades as mild processing technology as alternative to thermal pasteurisation, and is suitable for preservation of liquid food products such as fruit juices. PEF conditions typically applied at industrial scale for pasteurisation are high intensity pulsed electric fields aiming for minimal heat load, with an electric field strength (E) in the range of 15 − 20 kV/cm and pulse width (τ) between 2 − 20 μs. Alternativel...

  11. Cryogenic semiconductor high-intensity radiation monitors

    International Nuclear Information System (INIS)

    Palmieri, V.G.; Bell, W.H.; Borer, K.; Casagrande, L.; Da Via, C.; Devine, S.R.H.; Dezillie, B.; Esposito, A.; Granata, V.; Hauler, F.; Jungermann, L.; Li, Z.; Lourenco, C.; Niinikoski, T.O.; Shea, V. O'; Ruggiero, G.; Sonderegger, P.

    2003-01-01

    This paper describes a novel technique to monitor high-intensity particle beams by means of a semiconductor detector. It consists of cooling a semiconductor detector down to cryogenic temperature to suppress the thermally generated leakage current and to precisely measure the integrated ionization signal. It will be shown that such a device provides very good linearity and a dynamic range wider than is possible with existing techniques. Moreover, thanks to the Lazarus effect, extreme radiation hardness can be achieved providing in turn absolute intensity measurements against precise calibration of the device at low beam flux

  12. The utilization of high-intensity lasers

    International Nuclear Information System (INIS)

    Fabre, E.

    1988-01-01

    The 1988 progress report of the laboratory for the Utilization of High-Intensity Lasers (Polytechnic School, France), is presented. The research program is focused on the laser-plasma physics, on the generation of high pressures by means of laser shock heating, on the laser spectroscopy and on the laser implosions. Numerical simulation codes are developed. Concerning the atomic physics, the investigations on dense plasmas and the x-laser research developments are carried out. The research activities of the laboratory teams, the published papers, the national and international cooperations, are given [fr

  13. ORBIT : BEAM DYNAMICS CALCULATIONS FOR HIGH - INTENSITY RINGS

    International Nuclear Information System (INIS)

    HOLMES, J.A.; DANILOV, V.; GALAMBOS, J.; SHISHLO, A.; COUSINEAU, S.; CHOU, W.; MICHELOTTI, L.; OSTIGUY, F.; WEI, J.

    2002-01-01

    We are developing a computer code, ORBIT, specifically for beam dynamics calculations in high-intensity rings. Our approach allows detailed simulation of realistic accelerator problems. ORBIT is a particle-in-cell tracking code that transports bunches of interacting particles through a series of nodes representing elements, effects, or diagnostics that occur in the accelerator lattice. At present, ORBIT contains detailed models for strip-foil injection including painting and foil scattering; rf focusing and acceleration; transport through various magnetic elements; longitudinal and transverse impedances; longitudinal, transverse, and three-dimensional space charge forces; collimation and limiting apertures; and the calculation of many useful diagnostic quantities. ORBIT is an object-oriented code, written in C++ and utilizing a scripting interface for the convenience of the user. Ongoing improvements include the addition of a library of accelerator maps, BEAMLINE/MXYZPTLK the introduction of a treatment magnet errors and fringe fields; the conversion of the scripting interface to the standard scripting language, Python; and the parallelization of the computations using MPI. The ORBIT code is an open source, powerful, and convenient tool for studying beam dynamics in high-intensity rings

  14. Quenching of light flickering in synthetic guanine crystals in aqueous solutions under strong static magnetic fields

    Science.gov (United States)

    Mootha, A.; Takanezawa, Y.; Iwasaka, M.

    2018-05-01

    The present study focused on the vibration of micro crystal particles of guanine due to Brownian motion. The organic particle has a refractive index of 1.83 and caused a flickering of light. To test the possibility of using magnetic properties under wet conditions, changes in the frequency of particle vibration by applying magnetic fields were investigated. At first, we found that the exposure at 5 T inhibited the flickering light intensities and the particle vibration slightly decreased. Next, we carried out a high speed camera measurement of the Brownian motion of the particle with a time resolution of 100 flame per second (fps) with and without magnetic field exposures. It was revealed that the vibrational speed of synthetic particles was enhanced at 500 mT. Detailed analyses of the particle vibration by changing the direction of magnetic fields versus the light source revealed that the Brownian motion's vibrational frequency was entrained under magnetic fields at 500 mT, and an increase in vibration speed to 20Hz was observed. Additional measurements of light scattering fluctuation using photo-detector and analyses on auto-correlation also confirmed this speculation. The studied Brownian vibration may be influenced by the change in mechanical interactions between the vibration particles and surrounding medium. The discovered phenomena can be applied for molecular and biological interactions in future studies.

  15. Anticipating and addressing workplace static magnetic field effects at levels <0.5 mT.

    Science.gov (United States)

    Emery, R J; Hopkins, J R; Charlton, M A

    2000-11-01

    Magnetic resonance, once a research tool limited to the basic sciences, has experienced an increase in popularity due to its unique ability to analyze certain living systems in vivo. Expanding applications in the biomedical sciences have resulted in magnetic sources being located in research institutions nationally. Space and resource limitations sometimes necessitate siting magnetic resonance units in proximity to other institutional operations. For magnetic field shielding and personnel protection considerations, the generally accepted 0.5 mT (milliTesla) limit for implanted cardiac devices is commonly used as the conservative basis for decisions. But the effects of magnetic fields on equipment can be easily observed at levels far below 0.5 mT, often resulting in concern and apprehension on the part of personnel in the surrounding areas. Responding to recurrent worker concerns spawned by noticeable effects on equipment at exposure levels information, practicing radiation safety professionals can better anticipate facility incompatibility issues and improve their responses to worker concerns initiated by observed effects on equipment.

  16. Effects of a static inhomogeneous magnetic field acting on a laser-produced carbon plasma plume

    Directory of Open Access Journals (Sweden)

    M. Favre

    2017-08-01

    Full Text Available We present time- and space-resolved observations of the dynamics of a laser-produced carbon plasma, propagating in a sub-Tesla inhomogeneous magnetic field, with both, axial and radial field gradients. An Nd:YAG laser pulse, 340 mJ, 3.5 ns, at 1.06 μm, with a fluence of 7 J/cm2, is used to generate the plasma from a solid graphite target, in vacuum. The magnetic field is produced using two coaxial sets of two NeFeB ring magnets, parallel to the laser target surface. The diagnostics include plasma imaging with 50 ns time resolution, spatially resolved optical emission spectroscopy and Faraday cup. Based on our observations, evidence of radial and axial plasma confinement due to magnetic field gradients is presented. Formation of C2 molecules, previously observed in the presence of a low pressure neutral gas background, and enhanced on-axis ion flux, are ascribed to finite Larmor radius effects and reduced radial transport due to the presence of the magnetic field.

  17. High intensity neutrino source superconducting solenoid cyrostat design

    Energy Technology Data Exchange (ETDEWEB)

    Page, T.M.; Nicol, T.H.; Feher, S.; Terechkine, I.; Tompkins, J.; /Fermilab

    2006-06-01

    Fermi National Accelerator Laboratory (FNAL) is involved in the development of a 100 MeV superconducting linac. This linac is part of the High Intensity Neutrino Source (HINS) R&D Program. The initial beam acceleration in the front end section of the linac is achieved using room temperature spoke cavities, each of which is combined with a superconducting focusing solenoid. These solenoid magnets are cooled with liquid helium at 4.5K, operate at 250 A and have a maximum magnetic field strength of 7.5 T. The solenoid cryostat will house the helium vessel, suspension system, thermal shield, multilayer insulation, power leads, instrumentation, a vacuum vessel and cryogenic distribution lines. This paper discusses the requirements and detailed design of these superconducting solenoid cryostats.

  18. Magnetic static and scaling properties of the weak random-axis magnet (DyxY1-x)Al2

    International Nuclear Information System (INIS)

    Gehring, P.M.; Salamon, M.B.; del Moral, A.; Arnaudas, J.I.

    1990-01-01

    The effects of a random component of the magnetocrystalline anisotropy on the magnetic properties and critical behavior of polycrystalline DyAl 2 have been investigated using dc magnetic measurements. Random magnetic anisotropy (RMA) is produced by site-diluting ferromagnetic DyAl 2 with the nonmagnetic, isomorphic intermetallic YAl 2 . Dilution distorts the cubic Laves-phase unit cell because of a slight lattice mismatch thereby lowering the local crystal symmetry in a random fashion. Additional contributions to the RMA come from spin-orbit scattering by the conduction electrons. Hysteresis loops display little remanence and very small coercive fields, suggesting a weak RMA. This is consistent with estimates of the RMA strength D obtained using an approach of Chudnovsky et al. The magnetization at high temperatures (T>4T c ) is well described by a Curie-Weiss law. The paramagnetic Curie temperatures are positive, implying an average ferromagnetic exchange coupling between Dy ions, and increase with x. The paramagnetic moment shows no evidence of quenching across the series, thus confirming the well-localized nature of the 4f electronic orbitals. Low-field thermal scans of the bulk dc magnetization show no sign of a spontaneous moment for Dy concentrations 0.10≤x≤0.90, yet a sharp increase in the magnetization occurs at a temperature T c that increases with x. A ferromagnetic scaling analysis applied to the line of transitions at T c results in a surprisingly good collapse of the magnetization data. By extension of prior theoretical work of Aharony and Pytte, a direct connection can be made between pure and RMA exponents, which gives remarkable agreement with the experimental values

  19. Physics of high intensity nanosecond electron source

    International Nuclear Information System (INIS)

    Herrera-Gomez, A.; Spicer, W.E.

    1993-08-01

    A new high-intensity, short-time electron source is now being used at the Stanford Linear Accelerator Center (SLAC). Using a GaAs negative affinity semiconductor in the construction of the cathode, it is possible to fulfill operation requirements such as peak currents of tens of amperes, peak widths of the order of nanoseconds, hundreds of hours of operation stability, and electron spin polarization. The cathode is illuminated with high intensity laser pulses, and photoemitted electrons constitute the yield. Because of the high currents, some nonlinear effects are present. Very noticeable is the so-called Charge Limit (CL) effect, which consists of a limit on the total charge in each pulse-that is, the total bunch charge stops increasing as the light pulse total energy increases. In this paper, we explain the mechanism of the CL and how it is caused by the photovoltaic effect. Our treatment is based on the Three-Step model of photoemission. We relate the CL to the characteristics of the surface and bulk of the semiconductor, such as doping, band bending, surface vacuum level, and density of surface states. We also discuss possible ways to prevent the Char's Level effect

  20. High intensity discharge device containing oxytrihalides

    Science.gov (United States)

    Lapatovich, W.P.; Keeffe, W.M.; Liebermann, R.W.; Maya, J.

    1987-06-09

    A fill composition for a high intensity discharge device including mercury, niobium oxytrihalide, and a molecular stabilization agent is provided. The molar ratio of niobium oxytrihalide to the molecular stabilization agent in the fill is in the range of from about 5:1 to about 7.5:1. Niobium oxytrihalide is present in the fill in sufficient amount to produce, by dissociation in the discharge, atomic niobium, niobium oxide, NbO, and niobium dioxide, NbO[sub 2], with the molar ratio of niobium-containing vapor species to mercury in the fill being in the range of from about 0.01:1 to about 0.50:1; and mercury pressure of about 1 to about 50 atmospheres at lamp operating temperature. There is also provided a high intensity discharge device comprising a sealed light-transmissive arc tube; the arc tube including the above-described fill; and an energizing means for producing an electric discharge within the arc tube. 7 figs.

  1. Static and dynamic magnetization properties of Y1Ba2Cu3Oz thin films

    International Nuclear Information System (INIS)

    Sekula, S.T.

    1989-08-01

    Magnetization studies were carried out on Y 1 Ba 2 Cu 3 O z (YBCO) thin films that were e-beam evaporated onto circular discs of single-crystal SrTiO 3 with (001) and (110) faces as well as KTaO 3 with (001) faces. The measurements were made using vibrating sample (VSM) and SQUID-based magnetometry with the applied field perpendicular to the substrate surface. Critical current densities J c (H,T) are deduced from the magnetic hysteresis. Flux creep effects are observed over longer periods with the SQUID magnetometer. Analysis of the results of low frequency response of these films to collinear ac and dc magnetic fields are compared with the dc magnetometry results. J c (H,T) is observed to be quite sensitive to the type of epitaxial growth on the various substrates. 16 refs., 10 figs

  2. Generation of static magnetic fields by a test charge in a plasma with anisotropic electron temperature

    Energy Technology Data Exchange (ETDEWEB)

    Aliev, Yu.M.; Bychenkov, V.Yu.; Frolov, A.A. (AN SSSR, Moscow. Fizicheskij Inst.)

    Structure of electomagnetic field generated with a charge in a plasma with anisotropic electron temperature has been studied. Unlike a hydrodynamical approach to study on the magnetic field qeneration with a test charge a kinetic theory describing spatial distribution of both magnetic and electrostatic components of charge field was constructed. Such theory results permit to investigate the charge field structure both at distances larger than length of free electron path and not exceeding it. The developed theory can serve as the basis for development of new methods for anisotropic plasma diagnostics.

  3. Propagation of quasi-static wave and resonance cone in magnetized plasma

    International Nuclear Information System (INIS)

    Serbeto, A.P.B.

    1980-08-01

    The potential created by an oscillating punctual source in a magnetized homogeneous cold plasma, using quasistatic approximation is studied. The resonance cone structure in this plasma is theoretically obtained and it is verified that the conic field structure remains finite for an inhomogeneous cold plasma. The temperature effect in the resonance cone structure in layers where w->Ω e ,w->w PC and w->w nh for magnetized homogeneous electron plasma is studied. An approximated expression for dispersion relations is obtained, so that an analytical solution for the potential in these layers can be calculated. The theorem of energy conservation for quasistatic waves is developed. (M.C.K.) [pt

  4. Second Born approximation in elastic-electron scattering from nuclear static electro-magnetic multipoles

    International Nuclear Information System (INIS)

    Al-Khamiesi, I.M.; Kerimov, B.K.

    1988-01-01

    Second Born approximation corrections to electron scattering by nuclei with arbitrary spin are considered. Explicit integral expressions for the charge, magnetic dipole and interference differential cross sections are obtained. Magnetic and interference relative corrections are then investigated in the case of backward electron scattering using shell model form factors for nuclear targets 9 Be, 10 B, and 14 N. To understand exponential growth of these corrections with square of the electron energy K 0 2 , the case of electron scattering by 6 Li is considered using monopole model charge form factor with power-law asymptotics. 11 refs., 2 figs. (author)

  5. Linear and nonlinear intersubband optical absorption in a disk-shaped quantum dot with a parabolic potential plus an inverse squared potential in a static magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Liu Guanghui [Department of Physics, College of Physics and Electronic Engineering, Guangzhou University, Guangzhou 510006 (China); Guo Kangxian, E-mail: axguo@sohu.com [Department of Physics, College of Physics and Electronic Engineering, Guangzhou University, Guangzhou 510006 (China); Wang Chao [Institute of Public Administration, Guangzhou University, Guangzhou 510006 (China)

    2012-06-15

    The linear and nonlinear optical absorption in a disk-shaped quantum dot (DSQD) with parabolic potential plus an inverse squared potential in the presence of a static magnetic field are theoretically investigated within the framework of the compact-density-matrix approach and iterative method. The energy levels and the wave functions of an electron in the DSQD are obtained by using the effective mass approximation. Numerical calculations are presented for typical GaAs/AlAs DSQD. It is found that the optical absorption coefficients are strongly affected not only by a static magnetic field, but also by the strength of external field, the confinement frequency and the incident optical intensity.

  6. Detection of Static Eccentricity Fault in Saturated Induction Motors by Air-Gap Magnetic Flux Signature Analysis Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    N. Halem

    2013-06-01

    Full Text Available Unfortunately, motor current signature analysis (MCSA cannot detect the small degrees of the purely static eccentricity (SE defects, while the air-gap magnetic flux signature analysis (FSA is applied successfully. The simulation results are obtained by using time stepping finite elements (TSFE method. In order to show the impact of magnetic saturation upon the diagnosis of SE fault, the analysis is carried out for saturated induction motors. The index signatures of static eccentricity fault around fundamental and PSHs are detected successfully for saturated motor.

  7. DETECTION OF STATIC ECCENTRICITY FAULT IN SATURATED INDUCTION MOTORS BY AIR-GAP MAGNETIC FLUX SIGNATURE ANALYSIS USING FINITE ELEMENT METHOD

    Directory of Open Access Journals (Sweden)

    N. Halem

    2013-06-01

    Full Text Available Unfortunately, motor current signature analysis (MCSA cannot detect the small degrees of the purely static eccentricity (SE defects, while the air-gap magnetic flux signature analysis (FSA is applied successfully. The simulation results are obtained by using time stepping finite elements (TSFE method. In order to show the impact of magnetic saturation upon the diagnosis of SE fault, the analysis is carried out for saturated induction motors. The index signatures of static eccentricity fault around fundamental and PSHs are detected successfully for saturated motor.

  8. DETECTION OF STATIC ECCENTRICITY FAULT IN SATURATED INDUCTION MOTORS BY AIR-GAP MAGNETIC FLUX SIGNATURE ANALYSIS USING FINITE ELEMENT METHOD

    Directory of Open Access Journals (Sweden)

    N. Halem

    2015-07-01

    Full Text Available Unfortunately, motor current signature analysis (MCSA cannot detect the small degrees of the purely static eccentricity (SE defects, while the air-gap magnetic flux signature analysis (FSA is applied successfully. The simulation results are obtained by using time stepping finite elements (TSFE method. In order to show the impact of magnetic saturation upon the diagnosis of SE fault, the analysis is carried out for saturated induction motors. The index signatures of static eccentricity fault around fundamental and PSHs are detected successfully for saturated motor.

  9. Linear and nonlinear intersubband optical absorption in a disk-shaped quantum dot with a parabolic potential plus an inverse squared potential in a static magnetic field

    International Nuclear Information System (INIS)

    Liu Guanghui; Guo Kangxian; Wang Chao

    2012-01-01

    The linear and nonlinear optical absorption in a disk-shaped quantum dot (DSQD) with parabolic potential plus an inverse squared potential in the presence of a static magnetic field are theoretically investigated within the framework of the compact-density-matrix approach and iterative method. The energy levels and the wave functions of an electron in the DSQD are obtained by using the effective mass approximation. Numerical calculations are presented for typical GaAs/AlAs DSQD. It is found that the optical absorption coefficients are strongly affected not only by a static magnetic field, but also by the strength of external field, the confinement frequency and the incident optical intensity.

  10. Normal spectral emissivity measurement of molten copper using an electromagnetic levitator superimposed with a static magnetic field

    International Nuclear Information System (INIS)

    Kurosawa, Ryo; Inoue, Takamitsu; Baba, Yuya; Sugioka, Ken-ichi; Kubo, Masaki; Tsukada, Takao; Fukuyama, Hiroyuki

    2013-01-01

    The normal spectral emissivity of molten copper was determined in the wavelength range of 780–920 nm and in the temperature range of 1288–1678 K, by directly measuring the radiance emitted by an electromagnetically levitated molten copper droplet under a static magnetic field of 1.5 T. The spectrometer for radiance measurement was calibrated using the relation between the theoretical blackbody radiance from Planck's law and the light intensity of a quasi-blackbody radiation source measured using a spectrometer at a given temperature. As a result, the normal spectral emissivity of molten copper was determined as 0.075 ± 0.011 at a wavelength of 807 nm, and it was found that its temperature dependence is negligible in the entire measurement temperature range tested. In addition, the results of the normal spectral emissivity and its wavelength dependence were discussed, in comparison with those obtained using the Drude free-electron model. (paper)

  11. Low mass planet migration in magnetically torqued dead zones - I. Static migration torque

    Science.gov (United States)

    McNally, Colin P.; Nelson, Richard P.; Paardekooper, Sijme-Jan; Gressel, Oliver; Lyra, Wladimir

    2017-12-01

    Motivated by models suggesting that the inner planet forming regions of protoplanetary discs are predominantly lacking in viscosity-inducing turbulence, and are possibly threaded by Hall-effect generated large-scale horizontal magnetic fields, we examine the dynamics of the corotation region of a low-mass planet in such an environment. The corotation torque in an inviscid, isothermal, dead zone ought to saturate, with the libration region becoming both symmetrical and of a uniform vortensity, leading to fast inward migration driven by the Lindblad torques alone. However, in such a low viscosity situation, the material on librating streamlines essentially preserves its vortensity. If there is relative radial motion between the disc gas and the planet, the librating streamlines will no longer be symmetrical. Hence, if the gas is torqued by a large-scale magnetic field so that it undergoes a net inflow or outflow past the planet, driving evolution of the vortensity and inducing asymmetry of the corotation region, the corotation torque can grow, leading to a positive torque. In this paper, we treat this effect by applying a symmetry argument to the previously studied case of a migrating planet in an inviscid disc. Our results show that the corotation torque due to a laminar Hall-induced magnetic field in a dead zone behaves quite differently from that studied previously for a viscous disc. Furthermore, the magnetic field induced corotation torque and the dynamical corotation torque in a low viscosity disc can be regarded as one unified effect.

  12. QUASI-STATIC MODEL OF MAGNETICALLY COLLIMATED JETS AND RADIO LOBES. II. JET STRUCTURE AND STABILITY

    Energy Technology Data Exchange (ETDEWEB)

    Colgate, Stirling A.; Li, Hui [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Fowler, T. Kenneth [University of California, Berkeley, CA 94720 (United States); Hooper, E. Bickford [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); McClenaghan, Joseph; Lin, Zhihong [University of California, Irvine, CA 92697 (United States)

    2015-11-10

    This is the second in a series of companion papers showing that when an efficient dynamo can be maintained by accretion disks around supermassive black holes in active galactic nuclei, it can lead to the formation of a powerful, magnetically driven, and mediated helix that could explain both the observed radio jet/lobe structures and ultimately the enormous power inferred from the observed ultrahigh-energy cosmic rays. In the first paper, we showed self-consistently that minimizing viscous dissipation in the disk naturally leads to jets of maximum power with boundary conditions known to yield jets as a low-density, magnetically collimated tower, consistent with observational constraints of wire-like currents at distances far from the black hole. In this paper we show that these magnetic towers remain collimated as they grow in length at nonrelativistic velocities. Differences with relativistic jet models are explained by three-dimensional magnetic structures derived from a detailed examination of stability properties of the tower model, including a broad diffuse pinch with current profiles predicted by a detailed jet solution outside the collimated central column treated as an electric circuit. We justify our model in part by the derived jet dimensions in reasonable agreement with observations. Using these jet properties, we also discuss the implications for relativistic particle acceleration in nonrelativistically moving jets. The appendices justify the low jet densities yielding our results and speculate how to reconcile our nonrelativistic treatment with general relativistic MHD simulations.

  13. Advances in the design of superconducting magnetic bearings for static and dynamic applications

    International Nuclear Information System (INIS)

    Siems, S O; Canders, W-R

    2005-01-01

    Theoretical and experimental studies have led to an overall design for superconducting magnetic bearings (SMB) that is suitable to meet the requirements of industrial applications. The main benefits are high load capacities, compact dimensions and a 'warm' suspended part of the application. Two applications have been designed with a suspension provided only by SMB; one has already been built and tested successfully

  14. Production of high intensity radioactive beams

    International Nuclear Information System (INIS)

    Nitschke, J.M.

    1990-04-01

    The production of radioactive nuclear beams world-wide is reviewed. The projectile fragmentation and the ISOL approaches are discussed in detail, and the luminosity parameter is used throughout to compare different production methods. In the ISOL approach a thin and a thick target option are distinguished. The role of storage rings in radioactive beam research is evaluated. It is concluded that radioactive beams produced by the projectile fragmentation and the ISOL methods have complementary characteristics and can serve to answer different scientific questions. The decision which kind of facility to build has to depend on the significance and breadth of these questions. Finally a facility for producing a high intensity radioactive beams near the Coulomb barrier is proposed, with an expected luminosity of ∼10 39 cm -2 s -1 , which would yield radioactive beams in excess of 10 11 s -1 . 9 refs., 3 figs., 7 tabs

  15. A High Intensity Hadron Facility, AGS II

    International Nuclear Information System (INIS)

    Lee, Y.Y.; Lowenstein, D.I.

    1988-01-01

    We have present one of several possibilities for the evolution of the AGS complex into a high intensity hadron facility. One could consider other alternatives, such as using the AGS as the Collector and constructing a new 9-30 GeV machine. We believe the most responsible scenario must minimize the cost and downtime to the ongoing physics program. With a stepwise approach, starting with the Booster, the physics program can evolve without a single major commitment in funds. At each step an evaluation of the funds versus physics merit can be made. As a final aside, each upgrade at the AGS and Booster is presently being implemented to support an interleaved operation of both protons and ions. 1 fig., 6 tabs

  16. High intensity proton accelerator controls network upgrade

    International Nuclear Information System (INIS)

    Krempaska, R.; Bertrand, A.; Lendzian, F.; Lutz, H.

    2012-01-01

    The High Intensity Proton Accelerator (HIPA) control system network is spread through a vast area in PSI and it was grown historically in an unorganized way. The miscellaneous network hardware infrastructure and the lack of the documentation and components overview could no longer guarantee the reliability of the control system and the facility operation. Therefore, a new network, based on modern network topology, PSI standard hardware with monitoring and detailed documentation and overview was needed. The number of active components has been reduced from 25 to 9 Cisco Catalyst 24- or 48-port switches. They are the same type as other PSI switches, thus a replacement emergency stock is not an issue anymore. We would like to present how we successfully achieved this goal and the advantages of the clean and well documented network infrastructure. (authors)

  17. Nuclear reorientation in static and radio-frequency electro-magnetic fields

    International Nuclear Information System (INIS)

    Dubbers, D.

    1976-01-01

    Nuclear reorientation by external electromagnetic fields is treated using Fano's irreducible tensor formulation of the problem. Although the main purpose of this paper is the description of the effects of nuclear magnetic resonance (NMR) on an ensemble of oriented nuclei in the presence of a crystal electric field gradient (efg), the results are applicable to all types of nuclear or atomic orientation or angular correlation work. The theory is applied to a number of exemplary cases: magnetic field dependence of nuclear orientation in the presence of quadrupole interactions; sign determination in electric quadrupole coupling; line shapes of nuclear acoustic resonance (NAR) signals; quadrupole splitting and multiquantum transitions in NMR with oriented nuclei. (orig./WBU) [de

  18. Biological effects of static magnetic fields: a selective review with emphasis on risk assessment

    International Nuclear Information System (INIS)

    Easterly, C.E.

    1982-04-01

    Rather than focusing on literature per se, the current study determines the status of magnetic field information that is applicable to risk assessment. Hence, an attempt is made to identify both the literature that is useful to the goal of risk assessment and a framework within which risk assessment methodologies can be derived. From this selected review, it is concluded that three areas exist for which adequate information can be found to begin modelling: disease induction, reproduction and development, and cardiovascular response. The first two are supported by a combination of positive and negative findings and the last by a calculational technique which utilizes the physically well-known principle of flow retardation for a conducting fluid moving through a magnetic field

  19. Biological effects of static magnetic fields: a selective review with emphasis on risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Easterly, C. E.

    1982-04-01

    Rather than focusing on literature per se, the current study determines the status of magnetic field information that is applicable to risk assessment. Hence, an attempt is made to identify both the literature that is useful to the goal of risk assessment and a framework within which risk assessment methodologies can be derived. From this selected review, it is concluded that three areas exist for which adequate information can be found to begin modelling: disease induction, reproduction and development, and cardiovascular response. The first two are supported by a combination of positive and negative findings and the last by a calculational technique which utilizes the physically well-known principle of flow retardation for a conducting fluid moving through a magnetic field.

  20. Exposure of Postnatal Rats to a Static Magnetic Field of 0.14 T Influences Functional Laterality of the Hippocampal High-Affinity Choline Uptake System in Adulthood; In Vitro Test With Magnetic Nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Krištofíková, Z.; Čermák, M.; Benešová, O.; Klaschka, Jan; Zach, P.

    2005-01-01

    Roč. 30, č. 2 (2005), s. 253-262 ISSN 0364-3190 R&D Projects: GA MZd NF7576 Keywords : magnetic nanoparticles * choline transport * cholinergic * functional impairment * hippocampus * laterality * magnetoreception * static magnetic field Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.187, year: 2005

  1. Monte Carlo steps per spin vs. time in the master equation II: Glauber kinetics for the infinite-range ising model in a static magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Suhk Kun [Chungbuk National University, Chungbuk (Korea, Republic of)

    2006-01-15

    As an extension of our previous work on the relationship between time in Monte Carlo simulation and time in the continuous master equation in the infinit-range Glauber kinetic Ising model in the absence of any magnetic field, we explored the same model in the presence of a static magnetic field. Monte Carlo steps per spin as time in the MC simulations again turns out to be proportional to time in the master equation for the model in relatively larger static magnetic fields at any temperature. At and near the critical point in a relatively smaller magnetic field, the model exhibits a significant finite-size dependence, and the solution to the Suzuki-Kubo differential equation stemming from the master equation needs to be re-scaled to fit the Monte Carlo steps per spin for the system with different numbers of spins.

  2. Nonlinear Dynamics of a Magnetically Driven Duffing-Type Spring-Magnet Oscillator in the Static Magnetic Field of a Coil

    Science.gov (United States)

    Donoso, Guillermo; Ladera, Celso L.

    2012-01-01

    We study the nonlinear oscillations of a forced and weakly dissipative spring-magnet system moving in the magnetic fields of two fixed coaxial, hollow induction coils. As the first coil is excited with a dc current, both a linear and a cubic magnet-position dependent force appear on the magnet-spring system. The second coil, located below the…

  3. Magnetic solid phase extraction and static headspace gas chromatography-mass spectrometry method for the analysis of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Cai, Ying; Yan, Zhihong; Wang, Lijia; NguyenVan, Manh; Cai, Qingyun

    2016-01-15

    A magnetic solid phase extraction (MSPE) protocol combining a static headspace gas chromatography coupled to mass spectrometry (HS-GC-MS) method has been developed for extraction, and determination of 16 polycyclic aromatic hydrocarbons (PAHs) in drinking water samples. Magnetic nanoparticles (MNPs) were coated with 3-aminopropyltriethoxysilane and modified by cholesterol chloroformate. Transmission electron microscope, vibrating sample magnetometer, Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy were used to characterize the cholesterol-functionalized sorbents, and the main parameters affecting the extraction as well as HS sampling, such as sorbent amount, extraction time, oven temperature and equilibration time have been investigated and established. Combination with HS sampling, the MSPE procedure was simple, fast and environmentally friendly, without need of any organic solvent. Method validation proved the feasibility of the developed sorbents for the quantitation of the investigated analytes at trace levels obtaining the limit of detection (S/N=3) ranging from 0.20 to 7.8 ng/L. Good values for intra and inter-day precision were obtained (RSDs ≤ 9.9%). The proposed method was successfully applied to drinking water samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Observation of plasma rotation driven by static nonaxisymmetric magnetic fields in a tokamak.

    Science.gov (United States)

    Garofalo, A M; Burrell, K H; DeBoo, J C; deGrassie, J S; Jackson, G L; Lanctot, M; Reimerdes, H; Schaffer, M J; Solomon, W M; Strait, E J

    2008-11-07

    We present the first evidence for the existence of a neoclassical toroidal rotation driven in a direction counter to the plasma current by nonaxisymmetric, nonresonant magnetic fields. At high beta and with large injected neutral beam momentum, the nonresonant field torque slows down the plasma toward the neoclassical "offset" rotation rate. With small injected neutral beam momentum, the toroidal rotation is accelerated toward the offset rotation, with resulting improvement in the global energy confinement time. The observed magnitude, direction, and radial profile of the offset rotation are consistent with neoclassical theory predictions.

  5. Static equilibria of the interstellar gas in the presence of magnetic and gravitational fields

    International Nuclear Information System (INIS)

    Mouschovias, T.C.

    1975-01-01

    No exact self-consistent equilibrium calculations exist for (any model of) the system of the interstellar gas and the frozen-in magnetic field. On a large scale (approximately 1 kpc) this system is affected by the vertical galactic gravitational field, while on a small scale (approximately 1 pc) the self-gravitation of the gas comes into play and is responsible for the collapse of some clouds to form stars. Accessible equilibrium states are determined for the gas--field system on both of these scales. (U.S.)

  6. Surface-wave endash particle interactions in a cylindrical plasma submitted to a static magnetic field

    International Nuclear Information System (INIS)

    Dengra, A.

    1997-01-01

    A new theoretical model for the study of the surface-wave endash particle interactions in a plasma column in the presence of a constant external magnetic field has been developed. The model is based on the linear resolution of the Vlasov equation by the method of characteristics, with the specular reflection hypothesis at the wall. The expression obtained for the rate of increase of kinetic energy per electron permits the analysis of the influence of the critical parameters in this transference process. copyright 1997 American Institute of Physics

  7. Laser-driven platform for generation and characterization of strong quasi-static magnetic fields

    Czech Academy of Sciences Publication Activity Database

    Santos, J.J.; Bailly-Grandvaux, M.; Giuffrida, Lorenzo; Forestier-Colleoni, P.; Fujioka, H.; Zhang, Z.; Korneev, P.; Bouillaud, R.; Dorard, S.; Batani, D.; Chevrot, M.; Cross, J. E.; Crowston, R.; Dubois, J.L.; Gazave, J.; Gregori, G.; d'Humieres, E.; Hulin, S.; Ishihara, K.; Kojima, S.; Loyez, E.; Marqués, J.-R.; Morace, A.; Nicolaï, P.; Peyrusse, O.; Poyé, A.; Raffestin, D.; Ribolzi, J.; Roth, M.; Schaumann, G.; Serres, F.; Tikhonchuk, V.T.; Vacar, P.; Woolsey, N.

    2015-01-01

    Roč. 17, Aug (2015), s. 1-10, č. článku 083051. ISSN 1367-2630 R&D Projects: GA MŠk ED1.1.00/02.0061 Grant - others:ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061 Institutional support: RVO:68378271 Keywords : strong magnetic field * laser-driven coil targets * laser-plasma interaction Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.570, year: 2015

  8. Applications of High Intensity Proton Accelerators

    Science.gov (United States)

    Raja, Rajendran; Mishra, Shekhar

    2010-06-01

    Superconducting radiofrequency linac development at Fermilab / S. D. Holmes -- Rare muon decay experiments / Y. Kuno -- Rare kaon decays / D. Bryman -- Muon collider / R. B. Palmer -- Neutrino factories / S. Geer -- ADS and its potential / J.-P. Revol -- ADS history in the USA / R. L. Sheffield and E. J. Pitcher -- Accelerator driven transmutation of waste: high power accelerator for the European ADS demonstrator / J. L. Biarrotte and T. Junquera -- Myrrha, technology development for the realisation of ADS in EU: current status & prospects for realisation / R. Fernandez ... [et al.] -- High intensity proton beam production with cyclotrons / J. Grillenberger and M. Seidel -- FFAG for high intensity proton accelerator / Y. Mori -- Kaon yields for 2 to 8 GeV proton beams / K. K. Gudima, N. V. Mokhov and S. I. Striganov -- Pion yield studies for proton driver beams of 2-8 GeV kinetic energy for stopped muon and low-energy muon decay experiments / S. I. Striganov -- J-Parc accelerator status and future plans / H. Kobayashi -- Simulation and verification of DPA in materials / N. V. Mokhov, I. L. Rakhno and S. I. Striganov -- Performance and operational experience of the CNGS facility / E. Gschwendtner -- Particle physics enabled with super-conducting RF technology - summary of working group 1 / D. Jaffe and R. Tschirhart -- Proton beam requirements for a neutrino factory and muon collider / M. S. Zisman -- Proton bunching options / R. B. Palmer -- CW SRF H linac as a proton driver for muon colliders and neutrino factories / M. Popovic, C. M. Ankenbrandt and R. P. Johnson -- Rapid cycling synchrotron option for Project X / W. Chou -- Linac-based proton driver for a neutrino factory / R. Garoby ... [et al.] -- Pion production for neutrino factories and muon colliders / N. V. Mokhov ... [et al.] -- Proton bunch compression strategies / V. Lebedev -- Accelerator test facility for muon collider and neutrino factory R&D / V. Shiltsev -- The superconducting RF linac for muon

  9. Exposure to static magnetic fields and risk of accidents among a cohort of workers from a medical imaging device manufacturing facility

    NARCIS (Netherlands)

    Bongers, Suzan; Slottje, Pauline; Portengen, Lützen; Kromhout, Hans

    2016-01-01

    PURPOSE: To study the association between occupational MRI-related static magnetic fields (SMF) exposure and the occurrence of accidents. METHODS: Recent and career SMF exposure was assessed by linking a retrospective job exposure matrix to payroll based job histories, for a cohort of (former)

  10. High-intensity laser application in Orthodontics

    Directory of Open Access Journals (Sweden)

    Eduardo Franzotti Sant’Anna

    Full Text Available ABSTRACT Introduction: In dental practice, low-level laser therapy (LLLT and high-intensity laser therapy (HILT are mainly used for dental surgery and biostimulation therapy. Within the Orthodontic specialty, while LLLT has been widely used to treat pain associated with orthodontic movement, accelerate bone regeneration after rapid maxillary expansion, and enhance orthodontic tooth movement, HILT, in turn, has been seen as an alternative for addressing soft tissue complications associated to orthodontic treatment. Objective: The aim of this study is to discuss HILT applications in orthodontic treatment. Methods: This study describes the use of HILT in surgical treatments such as gingivectomy, ulotomy, ulectomy, fiberotomy, labial and lingual frenectomies, as well as hard tissue and other dental restorative materials applications. Conclusion: Despite the many applications for lasers in Orthodontics, they are still underused by Brazilian practitioners. However, it is quite likely that this demand will increase over the next years - following the trend in the USA, where laser therapies are more widely used.

  11. ''High intensity per bunch'' working group

    International Nuclear Information System (INIS)

    2001-01-01

    Third Generation Light Sources are supposed to store high intensity beams not only in many tightly spaced bunches (multibunch operation), but also in few bunch or even single lunch modes of operation, required for example for time structure experiments. Single bunch instabilities, driven by short-range wake fields, however spoil the beam quality, both longitudinally and transversely. Straightforward ways of handling them, by pushing up the chromaticity (ζ = ΔQ/(Δp/p)) for example, enabled to raise the charge per bunch, but to the detriment of beam lifetime. In addition, since the impedance of the vacuum chamber deteriorates with the installation of new insertion devices, the current thresholds tend to dope down continuously. The goal of this Working Group was then to review these limitations in the existing storage rings, where a large number of beam measurements have been performed to characterise them, and to discuss different strategies which are used against them. About 15 different laboratories reported on the present performance of storage rings, experiences gained in high charge per bunch, and on simulation results and theoretical studies. More than 25 presentations addressed the critical issues and stimulated the discussion. Four main topics came out: - Observation and experimental data; - Impedance studies and tracking codes; - Theoretical investigations; - Cures and feedback. (author)

  12. High intensity neutrino oscillation facilities in Europe

    CERN Document Server

    Edgecock, T.R.; Davenne, T.; Densham, C.; Fitton, M.; Kelliher, D.; Loveridge, P.; Machida, S.; Prior, C.; Rogers, C.; Rooney, M.; Thomason, J.; Wilcox, D.; Wildner, E.; Efthymiopoulos, I.; Garoby, R.; Gilardoni, S.; Hansen, C.; Benedetto, E.; Jensen, E.; Kosmicki, A.; Martini, M.; Osborne, J.; Prior, G.; Stora, T.; Melo-Mendonca, T.; Vlachoudis, V.; Waaijer, C.; Cupial, P.; Chancé, A.; Longhin, A.; Payet, J.; Zito, M.; Baussan, E.; Bobeth, C.; Bouquerel, E.; Dracos, M.; Gaudiot, G.; Lepers, B.; Osswald, F.; Poussot, P.; Vassilopoulos, N.; Wurtz, J.; Zeter, V.; Bielski, J.; Kozien, M.; Lacny, L.; Skoczen, B.; Szybinski, B.; Ustrzycka, A.; Wroblewski, A.; Marie-Jeanne, M.; Balint, P.; Fourel, C.; Giraud, J.; Jacob, J.; Lamy, T.; Latrasse, L.; Sortais, P.; Thuillier, T.; Mitrofanov, S.; Loiselet, M.; Keutgen, Th.; Delbar, Th.; Debray, F.; Trophine, C.; Veys, S.; Daversin, C.; Zorin, V.; Izotov, I.; Skalyga, V.; Burt, G.; Dexter, A.C.; Kravchuk, V.L.; Marchi, T.; Cinausero, M.; Gramegna, F.; De Angelis, G.; Prete, G.; Collazuol, G.; Laveder, M.; Mazzocco, M.; Mezzetto, M.; Signorini, C.; Vardaci, E.; Di Nitto, A.; Brondi, A.; La Rana, G.; Migliozzi, P.; Moro, R.; Palladino, V.; Gelli, N.; Berkovits, D.; Hass, M.; Hirsh, T.Y.; Schaumann, M.; Stahl, A.; Wehner, J.; Bross, A.; Kopp, J.; Neuffer, D.; Wands, R.; Bayes, R.; Laing, A.; Soler, P.; Agarwalla, S.K.; Cervera Villanueva, A.; Donini, A.; Ghosh, T.; Gómez Cadenas, J.J.; Hernández, P.; Martín-Albo, J.; Mena, O.; Burguet-Castell, J.; Agostino, L.; Buizza-Avanzini, M.; Marafini, M.; Patzak, T.; Tonazzo, A.; Duchesneau, D.; Mosca, L.; Bogomilov, M.; Karadzhov, Y.; Matev, R.; Tsenov, R.; Akhmedov, E.; Blennow, M.; Lindner, M.; Schwetz, T.; Fernández Martinez, E.; Maltoni, M.; Menéndez, J.; Giunti, C.; González García, M. C.; Salvado, J.; Coloma, P.; Huber, P.; Li, T.; López-Pavón, J.; Orme, C.; Pascoli, S.; Meloni, D.; Tang, J.; Winter, W.; Ohlsson, T.; Zhang, H.; Scotto-Lavina, L.; Terranova, F.; Bonesini, M.; Tortora, L.; Alekou, A.; Aslaninejad, M.; Bontoiu, C.; Kurup, A.; Jenner, L.J.; Long, K.; Pasternak, J.; Pozimski, J.; Back, J.J.; Harrison, P.; Beard, K.; Bogacz, A.; Berg, J.S.; Stratakis, D.; Witte, H.; Snopok, P.; Bliss, N.; Cordwell, M.; Moss, A.; Pattalwar, S.; Apollonio, M.

    2013-02-20

    The EUROnu project has studied three possible options for future, high intensity neutrino oscillation facilities in Europe. The first is a Super Beam, in which the neutrinos come from the decay of pions created by bombarding targets with a 4 MW proton beam from the CERN High Power Superconducting Proton Linac. The far detector for this facility is the 500 kt MEMPHYS water Cherenkov, located in the Fr\\'ejus tunnel. The second facility is the Neutrino Factory, in which the neutrinos come from the decay of {\\mu}+ and {\\mu}- beams in a storage ring. The far detector in this case is a 100 kt Magnetised Iron Neutrino Detector at a baseline of 2000 km. The third option is a Beta Beam, in which the neutrinos come from the decay of beta emitting isotopes, in particular 6He and 18Ne, also stored in a ring. The far detector is also the MEMPHYS detector in the Fr\\'ejus tunnel. EUROnu has undertaken conceptual designs of these facilities and studied the performance of the detectors. Based on this, it has determined the ph...

  13. Enhancement of TCE removal by a static magnetic field in a fungal biotrickling filter.

    Science.gov (United States)

    Quan, Yue; Wu, Hao; Guo, Chunyu; Han, Yu; Yin, Chengri

    2018-07-01

    A fungal biotrickling filter (BTF) was employed to treat trichloroethylene (TCE) gas under different magnetic field intensities (MFIs). When the TCE inlet concentrations were approximately 370, 500-900, and 1000 mg/m 3 , the removal performances followed the order: MFI 20.0 mT > MFI 60.0 mT > MFI 80.0 mT > MFI 0 mT. In particular, at a TCE inlet concentration of 1000 mg/m 3 , MFI 20.0 mT was significantly better than MFI 0 mT performance. The corresponding removal efficiencies and maximum elimination capacities were 52.9%, 4854.1 mg/m 3  h and 39.4%, 3594.8 mg/m 3  h, respectively. BTF was shut down completely for 7 days and rapidly recovered in 6-10 days. High-throughput sequencing indicated that MF significantly affected the fungal community and significantly improved the relative abundance of the phylum Ascomycota, achieving the highest abundance of Ascomycota at MFI 20.0. These results indicated that a lower MFI can efficiently improve TCE removal performance in a fungal BTF. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Effect of static magnetic field on trichloroethylene removal in a biotrickling filter.

    Science.gov (United States)

    Quan, Yue; Wu, Hao; Yin, Zhenhao; Fang, Yingyu; Yin, Chengri

    2017-09-01

    A laboratory-scale biotrickling filter combined with a magnetic field (MF-BTF) and a single BTF (S-BTF) were set up to treat trichloroethylene (TCE) gas. The influences of phenol alone and NaAc-phenol as co-substrates and different MF intensities were investigated. At low MF intensity, MF-BTF displayed better performance with 0.20g/L of phenol, 53.6-337.1mg/m 3 of TCE, and empty bed residence times of 202.5s. The performances followed the order MF-BTF (60.0mT)>MF-BTF (30.0mT)>S-BTF (0mT)>MF-BTF (130.0mT), and the removal efficiencies (REs) and maximum elimination capacities (ECs) corresponded to: 92.2%-45.5%, 2656.8mg/m 3 h; 89.8%-37.2%, 2169.1mg/m 3 h; 89.8%-29.8%, 1967.7mg/m 3 h; 76.0%-20.8%, 1697.1mg/m 3 h, respectively. High-throughput sequencing indicated that the bacterial diversity was lower, whereas the relative abundances of Acinetobacter, Chryseobacterium, and Acidovorax were higher in MF-BTF. Results confirmed that a proper MF could improve TCE removal performance in BTF. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Experimental investigation of vector static magnetic field detection using an NV center with a single first-shell 13C nuclear spin in diamond

    Science.gov (United States)

    Jiang, Feng-Jian; Ye, Jian-Feng; Jiao, Zheng; Jiang, Jun; Ma, Kun; Yan, Xin-Hu; Lv, Hai-Jiang

    2018-05-01

    We perform a proof-of-principle experiment that uses a single negatively charged nitrogen–vacancy (NV) color center with a nearest neighbor 13C nuclear spin in diamond to detect the strength and direction (including both polar and azimuth angles) of a static vector magnetic field by optical detection magnetic resonance (ODMR) technique. With the known hyperfine coupling tensor between an NV center and a nearest neighbor 13C nuclear spin, we show that the information of static vector magnetic field could be extracted by observing the pulsed continuous wave (CW) spectrum. Project supported by the National Natural Science Foundation of China (Grant Nos. 11305074, 11135002, and 11275083), the Key Program of the Education Department Outstanding Youth Foundation of Anhui Province, China (Grant No. gxyqZD2017080), and the Education Department Natural Science Foundation of Anhui Province, China (Grant No. KJHS2015B09).

  16. High Intensity Organic Light-emitting Diodes

    Science.gov (United States)

    Qi, Xiangfei

    This thesis is dedicated to the fabrication, modeling, and characterization to achieve high efficiency organic light-emitting diodes (OLEDs) for illumination applications. Compared to conventional lighting sources, OLEDs enabled the direct conversion of electrical energy into light emission and have intrigued the world's lighting designers with the long-lasting, highly efficient illumination. We begin with a brief overview of organic technology, from basic organic semiconductor physics, to its application in optoelectronics, i.e. light-emitting diodes, photovoltaics, photodetectors and thin-film transistors. Due to the importance of phosphorescent materials, we will focus on the photophysics of metal complexes that is central to high efficiency OLED technology, followed by a transient study to examine the radiative decay dynamics in a series of phosphorescent platinum binuclear complexes. The major theme of this thesis is the design and optimization of a novel architecture where individual red, green and blue phosphorescent OLEDs are vertically stacked and electrically interconnected by the compound charge generation layers. We modeled carrier generation from the metal-oxide/doped organic interface based on a thermally assisted tunneling mechanism. The model provides insights to the optimization of a stacked OLED from both electrical and optical point of view. To realize the high intensity white lighting source, the efficient removal of heat is of a particular concern, especially in large-area devices. A fundamental transfer matrix analysis is introduced to predict the thermal properties in the devices. The analysis employs Laplace transforms to determine the response of the system to the combined effects of conduction, convection, and radiation. This perspective of constructing transmission matrices greatly facilitates the calculation of transient coupled heat transfer in a general multi-layer composite. It converts differential equations to algebraic forms, and

  17. A spot check for assessing static orientation consistency of inertial and magnetic sensing units.

    Science.gov (United States)

    Picerno, Pietro; Cereatti, Andrea; Cappozzo, Aurelio

    2011-03-01

    Despite the widespread use of Magnetic and Inertial Measurement Units (MIMUs) for movement reconstruction, only a few studies have tackled issues related to their accuracy. It has been proved that their performance decreases over a period of use since calibration parameters become no longer effective. Good practice rules recommend to assess, prior to any experimental session, the instrumental errors associated to the relevant measures. Aim of this study was to provide a practical and reproducible spot check for assessing the performance of MIMUs in terms of consistency in determining their orientation with respect to a common (inter-MIMUs consistency, IC) and invariant (self-MIMU consistency, SC) global frame. IC was assessed by verifying the hypothesis that the orientation of 9 MIMUs aligned to each other on a rigid Plexiglas plank coincided at any orientation of the plank. SC was assessed separately by verifying differences between measured and imposed known rotations imparted to each MIMU. The orientation of MIMUs relative to the global frame was expressed in terms of quaternion. IC test showed that MIMUs defined their orientation differently. This difference was not constant but varied according to the plank's orientation. The least consistent MIMU showed discrepancy up to 5.7°. SC test confirmed the same MIMU as that affected by the highest inaccuracy (8.4°), whereas it revealed errors within limits (1°) in correspondence to other MIMUs. A tool has been proposed that allows the users to be aware of the errors that may be expected when using MIMUs for the estimate of absolute and relative segments kinematics. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Electronic orbital response of regular extended and infinite periodic systems to magnetic fields. I. Theoretical foundations for static case

    Science.gov (United States)

    Springborg, Michael; Molayem, Mohammad; Kirtman, Bernard

    2017-09-01

    A theoretical treatment for the orbital response of an infinite, periodic system to a static, homogeneous, magnetic field is presented. It is assumed that the system of interest has an energy gap separating occupied and unoccupied orbitals and a zero Chern number. In contrast to earlier studies, we do not utilize a perturbation expansion, although we do assume the field is sufficiently weak that the occurrence of Landau levels can be ignored. The theory is developed by analyzing results for large, finite systems and also by comparing with the analogous treatment of an electrostatic field. The resulting many-electron Hamilton operator is forced to be hermitian, but hermiticity is not preserved, in general, for the subsequently derived single-particle operators that determine the electronic orbitals. However, we demonstrate that when focusing on the canonical solutions to the single-particle equations, hermiticity is preserved. The issue of gauge-origin dependence of approximate solutions is addressed. Our approach is compared with several previously proposed treatments, whereby limitations in some of the latter are identified.

  19. Antioxidant capacity of parsley cells (Petroselinum crispum L.) in relation to iron-induced ferritin levels and static magnetic field.

    Science.gov (United States)

    Rajabbeigi, Elham; Ghanati, Faezeh; Abdolmaleki, Parviz; Payez, Atefeh

    2013-12-01

    This study was aimed to evaluate antioxidant response of parsley cells to 21 ppm iron and static magnetic field (SMF; 30 mT). The activity of catalase (CAT) and ascorbate peroxidase (APX) and the contents of malonyldialdehyde, iron and ferritin were measured at 6 and 12 h after treatments. Exposure to SMF increased the activity of CAT in treated cells, while combination of iron and SMF treatments as well as iron supply alone decreased CAT activity, compared to that of control cells. Combination of SMF with iron treatment reduced iron content of the cells and ameliorated mal effect of iron on CAT activity. All treatments reduced APX activity; however, the content of total ascorbate increased in response to iron and SMF+iron. The results showed that among the components of antioxidant system of parsley cells, enhanced activity of CAT in SMF-treated cells and increase of ascorbate in SMF+Fe-treated ones were responsible for the maintenance of membranes integrity. Ferritin contents of SMF- and SMF+Fe-treated cells also decreased significantly 12 h after treatments, compared to those of the control cells. These results cast doubt on the proposed functions of ferritin as a putative reactive oxygen species detoxifying molecule.

  20. Non-thermal radio frequency and static magnetic fields increase rate of hemoglobin deoxygenation in a cell-free preparation.

    Directory of Open Access Journals (Sweden)

    David Muehsam

    Full Text Available The growing body of clinical and experimental data regarding electromagnetic field (EMF bioeffects and their therapeutic applications has contributed to a better understanding of the underlying mechanisms of action. This study reports that two EMF modalities currently in clinical use, a pulse-modulated radiofrequency (PRF signal, and a static magnetic field (SMF, applied independently, increased the rate of deoxygenation of human hemoglobin (Hb in a cell-free assay. Deoxygenation of Hb was initiated using the reducing agent dithiothreitol (DTT in an assay that allowed the time for deoxygenation to be controlled (from several min to several hours by adjusting the relative concentrations of DTT and Hb. The time course of Hb deoxygenation was observed using visible light spectroscopy. Exposure for 10-30 min to either PRF or SMF increased the rate of deoxygenation occurring several min to several hours after the end of EMF exposure. The sensitivity and biochemical simplicity of the assay developed here suggest a new research tool that may help to further the understanding of basic biophysical EMF transduction mechanisms. If the results of this study were to be shown to occur at the cellular and tissue level, EMF-enhanced oxygen availability would be one of the mechanisms by which clinically relevant EMF-mediated enhancement of growth and repair processes could occur.

  1. A Stewart isolator with high-static-low-dynamic stiffness struts based on negative stiffness magnetic springs

    Science.gov (United States)

    Zheng, Yisheng; Li, Qingpin; Yan, Bo; Luo, Yajun; Zhang, Xinong

    2018-05-01

    In order to improve the isolation performance of passive Stewart platforms, the negative stiffness magnetic spring (NSMS) is employed to construct high static low dynamic stiffness (HSLDS) struts. With the NSMS, the resonance frequencies of the platform can be reduced effectively without deteriorating its load bearing capacity. The model of the Stewart isolation platform with HSLDS struts is presented and the stiffness characteristic of its struts is studied firstly. Then the nonlinear dynamic model of the platform including both geometry nonlinearity and stiffness nonlinearity is established; and its simplified dynamic model is derived under the condition of small vibration. The effect of nonlinearity on the isolation performance is also evaluated. Finally, a prototype is built and the isolation performance is tested. Both simulated and experimental results demonstrate that, by using the NSMS, the resonance frequencies of the Stewart isolator are reduced and the isolation performance in all six directions is improved: the isolation frequency band is increased and extended to a lower-frequency level.

  2. The effect of highly potent, static magnetic fields used in magnetic resonance tomography (MRT) on the red-green vision of man

    International Nuclear Information System (INIS)

    Hancken, G.C.W.

    1989-01-01

    The ability of red-green differentiation before and after MRT exposure to a static magnetic field of a potency of 0.5 Tesla was examined in a total of 32 volunteers and contrastet to that of 128 further test persons before and after CT, linear accelerator irradiation and ultrasonography as well as to findings revealed in a control group. The greatest number of significant colour misjudgements was seen in the MRT group, where 57% of patients had deteriorated colour vision. Volunteers treated at CT units or linear accelerators also showed deviations from the normal red-green vision in 48.5% and 38.7% of cases. In the ultrasound and control groups, no more than 25% and 13.3% of the values measured using the anomaloscope suggested changes from normal. Exposure to a 0.5 Tesla magnetic field led to slight shifts in colour vision for a great number of patients. These appear to be brought about by light-sensitive photoreceptors in the retinal cone cells that respond to magnetic field influences. Theories about the underlying mechanisms are explained and discussed. The results obtained in the ultrasound and control groups have, however, also made evident that some individuals are prone to changes in colour vision without having been exposed to any measurable physical influences. These appear to be chiefly attributable to factors like stress. It would be most interesting to know to which extent study results such as these are distorted by personal perceptions and mental factors. (orig./MG) [de

  3. Static magnets: what are they and what do they do? Magnetos estáticos: o que são e para que servem?

    Directory of Open Access Journals (Sweden)

    L Laakso

    2009-02-01

    Full Text Available INTRODUCTION: Therapeutic static magnets have gained wide community acceptance for neuromusculoskeletal pain relief in many countries yet, apart from strong anecdotal reports of benefit, there is a paucity of scientific evidence for their use. OBJECTIVES: In this review we describe the physical characteristics of traditional and commonplace unipolar and bipolar static magnets as well as newer quadripolar magnetic arrays; discuss what is known of the physiological effects of static magnets and the strength of the literature; and make suggestions for targeted future research for static magnets in the management of neuromusculoskeletal pain conditions.INTRODUÇÃO: A magnetoterapia estática conquistou ampla aceitação da comunidade para alívio da dor neuromusculoesquelética em diversos países. No entanto, com exceção de relatórios anedóticos de seus benefícios, há uma grande escassez de evidências científicas para seu uso. OBJETIVOS: Nesta revisão, descrevemos as características físicas dos tradicionais magnetos estáticos unipolares e bipolares comuns, assim como os mais recentes conjuntos magnéticos quadripolares; discutimos o que se conhece sobre os efeitos fisiológicos da magnetoterapia estática e o suporte da literatura; e fazemos sugestões para futuras pesquisas direcionadas à magnetoterapia estática no controle de condições de dor neuromusculoesquelética.

  4. Behavior of Particle Depots in Molten Silicon During Float-Zone Growth in Strong Static Magnetic Fields

    Science.gov (United States)

    Jauss, T.; SorgenFrei, T.; Croell, A.; Azizi, M.; Reimann, C.; Friedrich, J.; Volz, M. P.

    2014-01-01

    In the photovoltaics industry, the largest market share is represented by solar cells made from multicrystalline silicon, which is grown by directional solidification. During the growth process, the silicon melt is in contact with the silicon nitride coated crucible walls and the furnace atmosphere which contains carbon monoxide. The dissolution of the crucible coating, the carbon bearing gas, and the carbon already present in the feedstock, lead to the precipitation of silicon carbide, and silicon nitride, at later stages of the growth process. The precipitation of Si3N4 and SiC particles of up to several hundred micrometers in diameter leads to severe problems during the wire sawing process for wafering the ingots. Furthermore the growth of the silicon grains can be negatively influenced by the presence of particles, which act as nucleation sources and lead to a grit structure of small grains and are sources for dislocations. If doped with Nitrogen from the dissolved crucible coating, SiC is a semi conductive material, and can act as a shunt, short circuiting parts of the solar cell. For these reasons, the incorporation of such particles needs to be avoided. In this contribution we performed model experiments in which the transport of intentionally added SiC particles and their interaction with the solid-liquid interface during float zone growth of silicon in strong steady magnetic fields was investigated. SiC particles of 7µm and 60µm size are placed in single crystal silicon [100] and [111] rods of 8mm diameter. This is achieved by drilling a hole of 2mm diameter, filling in the particles and closing the hole by melting the surface of the rod until a film of silicon covers the hole. The samples are processed under a vacuum of 1x10(exp -5) mbar or better, to prevent gas inclusions. An oxide layer to suppress Marangoni convection is applied by wet oxidation. Experiments without and with static magnetic field are carried out to investigate the influence of melt

  5. Photoproduction at high energy and high intensity

    CERN Multimedia

    2002-01-01

    The photon beam used for this programme is tagged and provides a large flux up to very high energies (150-200 GeV). It is also hadron-free, since it is obtained by a two-step conversion method. A spectrometer is designed to exploit this beam and to perform a programme of photoproduction with a high level of sensitivity (5-50 events/picobarn).\\\\ \\\\ Priority will be given to the study of processes exhibiting the point-like behaviour of the photon, especially deep inelastic Compton scattering. The spectrometer has two magnets. Charged tracks are measured by MWPC's located only in field-free regions. Three calorimeters provide a large coverage for identifying and measuring electrons and photons. An iron filter downstream identifies muons. Most of the equipment is existing and recuperated from previous experiments.

  6. Renal transplant failure due to urologic complications: Comparison of static fluid with contrast-enhanced magnetic resonance urography

    Energy Technology Data Exchange (ETDEWEB)

    Blondin, D. [University Hospital Duesseldorf, Institute of Diagnostic Radiology, Moorenstr. 5, D-40225 Duesseldorf (Germany)], E-mail: blondin@med.uni-duesseldorf.de; Koester, A.; Andersen, K.; Kurz, K.D.; Moedder, U.; Cohnen, M. [University Hospital Duesseldorf, Institute of Diagnostic Radiology, Moorenstr. 5, D-40225 Duesseldorf (Germany)

    2009-02-15

    Purpose: Postrenal reasons of renal transplant failure can be assessed by magnetic resonance urography. This study was designed to retrospectively compare the diagnostic accuracy of static fluid (T2-)MRU compared to contrast enhanced (CE-)MRU in patients with renal transplant failure. Material and methods: Thirty-five consecutive patients (14 female, 21 men; mean age 48.6 years) with renal transplant failure and sonographically detected hydronephrosis were examined both with T2-MRU as well as CE-MRU resulting in 39 MRU examinations. MRU was performed both using T2-weighted HASTE-sequence (T2-MRU) as well as Gadolinium-enhanced 3D-FLASH-sequence (CE-MRU) on a 1.5-T clinical MRI scanner (Magnetom Vision, Siemens Medical Solutions). Subjective image quality of resulting maximum intensity projection was assessed in consensus by two readers blinded to the final diagnosis, using a five point scale. MRU findings were correlated to sonography, operative results or clinical follow up. Results: CE-MRU yielded a sensitivity of 85.7% (T2-MRU 76.2%), and a specificity of 83.3% (T2-MRU: 73.7%), however statistical significance was not reached. The subjective image quality was significantly better in CE-MRU. Conclusions: Only concerning subjective image quality CE-MRU proved superior to T2-MRU. Yet, there was no significant difference in diagnostic accuracy between T2- and CE-MRU. Thinking of incipient nephrogenic systemic fibrosis, T2-MRU can be used as reliable alternative in patients with decreased renal transplant function due to urological complications.

  7. Renal transplant failure due to urologic complications: Comparison of static fluid with contrast-enhanced magnetic resonance urography

    International Nuclear Information System (INIS)

    Blondin, D.; Koester, A.; Andersen, K.; Kurz, K.D.; Moedder, U.; Cohnen, M.

    2009-01-01

    Purpose: Postrenal reasons of renal transplant failure can be assessed by magnetic resonance urography. This study was designed to retrospectively compare the diagnostic accuracy of static fluid (T2-)MRU compared to contrast enhanced (CE-)MRU in patients with renal transplant failure. Material and methods: Thirty-five consecutive patients (14 female, 21 men; mean age 48.6 years) with renal transplant failure and sonographically detected hydronephrosis were examined both with T2-MRU as well as CE-MRU resulting in 39 MRU examinations. MRU was performed both using T2-weighted HASTE-sequence (T2-MRU) as well as Gadolinium-enhanced 3D-FLASH-sequence (CE-MRU) on a 1.5-T clinical MRI scanner (Magnetom Vision, Siemens Medical Solutions). Subjective image quality of resulting maximum intensity projection was assessed in consensus by two readers blinded to the final diagnosis, using a five point scale. MRU findings were correlated to sonography, operative results or clinical follow up. Results: CE-MRU yielded a sensitivity of 85.7% (T2-MRU 76.2%), and a specificity of 83.3% (T2-MRU: 73.7%), however statistical significance was not reached. The subjective image quality was significantly better in CE-MRU. Conclusions: Only concerning subjective image quality CE-MRU proved superior to T2-MRU. Yet, there was no significant difference in diagnostic accuracy between T2- and CE-MRU. Thinking of incipient nephrogenic systemic fibrosis, T2-MRU can be used as reliable alternative in patients with decreased renal transplant function due to urological complications

  8. Survey of risks related to static magnetic fields in ultra high field MRI; Bestandsaufnahme zu Risiken durch statische Magnetfelder im Zusammenhang mit der Ultrahochfeld-MRT

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, H.E. [Max-Planck-Inst. fuer Kognitions- und Neurowissenschaften, Leipzig (Germany); Cramon, D.Y. von [Max-Planck-Inst. fuer Kognitions- und Neurowissenschaften, Leipzig (Germany); Max-Planck-Inst. fuer Neurologische Forschung, Koeln (Germany)

    2008-04-15

    In magnetic resonance imaging (MRI), substantial improvements with respect to sensitivity are expected due to the development of so-called ultra high field scanners, i.e., whole-body scanners with a magnetic field strength of 7 T or above. Users of this technology need to evaluate this benefit for potential risks since commercially available systems are not certified as a medical device for human use. This review provides a detailed survey of static field bioeffects related to the exposure of subjects being scanned, to occupational exposure, and to exposure of the general public under consideration of current standards and directives. According to present knowledge, it is not expected that exposure of human subjects to static magnetic fields of 7 T implies a specific risk of damage or disease provided that known contraindications are observed. The available database does not permit definition of exact thresholds for harmful effects. However, experience from previous application of ultra high field MRI indicates that transient phenomena, such as vertigo, nausea, metallic taste, or magnetophosphenes, are more frequently observed. In particular, movements in the field or the gradient of the fringe field seem to lead to detectable effects. Besides such observations, there is a strong demand for systematic investigation of potential interaction mechanisms related to static field exposure during MRI examinations. (orig.)

  9. A wheel-shaped single-molecule magnet of [MnII 3MnIII 4]: quantum tunneling of magnetization under static and pulse magnetic fields.

    Science.gov (United States)

    Koizumi, Satoshi; Nihei, Masayuki; Shiga, Takuya; Nakano, Motohiro; Nojiri, Hiroyuki; Bircher, Roland; Waldmann, Oliver; Ochsenbein, Stefan T; Güdel, Hans U; Fernandez-Alonso, Felix; Oshio, Hiroki

    2007-01-01

    The reaction of N-(2-hydroxy-5-nitrobenzyl)iminodiethanol (=H3(5-NO2-hbide)) with Mn(OAc)2* 4 H2O in methanol, followed by recrystallization from 1,2-dichloroethane, yielded a wheel-shaped single-molecule magnet (SMM) of [MnII 3MnIII 4(5-NO2-hbide)6].5 C2H4Cl2 (1). In 1, seven manganese ions are linked by six tri-anionic ligands and form the wheel in which the two manganese ions on the rim and the one in the center are MnII and the other four manganese ions are MnIII ions. Powder magnetic susceptibility measurements showed a gradual increase with chimT values as the temperature was lowered, reaching a maximum value of 53.9 emu mol(-1) K. Analyses of magnetic susceptibility data suggested a spin ground state of S=19/2. The zero-field splitting parameters of D and B 0 4 were estimated to be -0.283(1) K and -1.64(1)x10(-5) K, respectively, by high-field EPR measurements (HF-EPR). The anisotropic parameters agreed with those estimated from magnetization and inelastic neutron scattering experiments. AC magnetic susceptibility measurements showed frequency-dependent in- and out-of-phase signals, characteristic data for an SMM, and an Arrhenius plot of the relaxation time gave a re-orientation energy barrier (DeltaE) of 18.1 K and a pre-exponential factor of 1.63x10(-7) s. Magnetization experiments on aligned single crystals below 0.7 K showed a stepped hysteresis loop, confirming the occurrence of quantum tunneling of the on magnetization (QTM). QTM was, on the other hand, suppressed by rapid sweeps of the magnetic field even at 0.5 K. The sweep-rate dependence of the spin flips can be understood by considering the Landau-Zener-Stückelberg (LZS) model.

  10. Nonlinear dynamics of a magnetically driven Duffing-type spring–magnet oscillator in the static magnetic field of a coil

    International Nuclear Information System (INIS)

    Donoso, Guillermo; Ladera, Celso L

    2012-01-01

    We study the nonlinear oscillations of a forced and weakly dissipative spring–magnet system moving in the magnetic fields of two fixed coaxial, hollow induction coils. As the first coil is excited with a dc current, both a linear and a cubic magnet-position dependent force appear on the magnet–spring system. The second coil, located below the first, excited with an ac current, provides the oscillating magnetic driving force on the system. From the magnet–coil interactions, we obtain, analytically, the nonlinear motion equation of the system, found to be a forced and damped cubic Duffing oscillator moving in a quartic potential. The relative strengths of the coefficients of the motion equation can be easily set by varying the coils’ dc and ac currents. We demonstrate, theoretically and experimentally, the nonlinear behaviour of this oscillator, including its oscillation modes and nonlinear resonances, the fold-over effect, the hysteresis and amplitude jumps, and its chaotic behaviour. It is an oscillating system suitable for teaching an advanced experiment in nonlinear dynamics both at senior undergraduate and graduate levels. (paper)

  11. Formation of a high intensity low energy positron string

    Science.gov (United States)

    Donets, E. D.; Donets, E. E.; Syresin, E. M.; Itahashi, T.; Dubinov, A. E.

    2004-05-01

    The possibility of a high intensity low energy positron beam production is discussed. The proposed Positron String Trap (PST) is based on the principles and technology of the Electron String Ion Source (ESIS) developed in JINR during the last decade. A linear version of ESIS has been used successfully for the production of intense highly charged ion beams of various elements. Now the Tubular Electron String Ion Source (TESIS) concept is under study and this opens really new promising possibilities in physics and technology. In this report, we discuss the application of the tubular-type trap for the storage of positrons cooled to the cryogenic temperatures of 0.05 meV. It is intended that the positron flux at the energy of 1-5 eV, produced by the external source, is injected into the Tubular Positron Trap which has a similar construction as the TESIS. Then the low energy positrons are captured in the PST Penning trap and are cooled down because of their synchrotron radiation in the strong (5-10 T) applied magnetic field. It is expected that the proposed PST should permit storing and cooling to cryogenic temperature of up to 5×109 positrons. The accumulated cooled positrons can be used further for various physics applications, for example, antihydrogen production.

  12. Formation of a high intensity low energy positron string

    International Nuclear Information System (INIS)

    Donets, E.D.; Donets, E.E.; Syresin, E.M.; Itahashi, T.; Dubinov, A.E.

    2004-01-01

    The possibility of a high intensity low energy positron beam production is discussed. The proposed Positron String Trap (PST) is based on the principles and technology of the Electron String Ion Source (ESIS) developed in JINR during the last decade. A linear version of ESIS has been used successfully for the production of intense highly charged ion beams of various elements. Now the Tubular Electron String Ion Source (TESIS) concept is under study and this opens really new promising possibilities in physics and technology. In this report, we discuss the application of the tubular-type trap for the storage of positrons cooled to the cryogenic temperatures of 0.05 meV. It is intended that the positron flux at the energy of 1-5 eV, produced by the external source, is injected into the Tubular Positron Trap which has a similar construction as the TESIS. Then the low energy positrons are captured in the PST Penning trap and are cooled down because of their synchrotron radiation in the strong (5-10 T) applied magnetic field. It is expected that the proposed PST should permit storing and cooling to cryogenic temperature of up to 5x10 9 positrons. The accumulated cooled positrons can be used further for various physics applications, for example, antihydrogen production

  13. High intensity region segmentation in MR imaging of multiple sclerosis

    International Nuclear Information System (INIS)

    Rodrigo, F; Filipuzzi, M; Graffigna, J P; Isoardi, R; Noceti, M

    2013-01-01

    Numerous pathologies are often manifest in Magnetic Resonance Imaging (MRI) as hyperintense or bright regions as compared to normal tissue. It is of particular interest to develop an algorithm to detect, identify and define those Regions of Interest (ROI) when analyzing MRI studies, particularly for lesions of Multiple Sclerosis (MS). The objective of this study is to analyze those parameters which optimize segmentation of the areas of interest. To establish which areas should be considered as hyperintense regions, we developed a database (DB), with studies of patients diagnosed with MS. This disease causes axonal demyelination and it is expressed as bright regions in PD, T2 and FLAIR MRI sequences. Thus, with more than 4300 hyperintense regions validated by an expert physician, an algorithm was developed to detect such spots, approximating the results the expert obtained. Alongside these hyperintense lesion regions, it also detected bone regions with high intensity levels, similar to the intensity of the lesions, but with other features that allow a good differentiation.The algorithm will then detect ROIs with similar intensity levels and performs classification through data mining techniques

  14. Time evolution of the vacuum - pair production in high intensity laser fields

    Energy Technology Data Exchange (ETDEWEB)

    Woellert, Anton; Bauke, Heiko; Keitel, Christoph H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2013-07-01

    Interaction between the vacuum and high intensity lasers will lead to new possibilities in high-field physics. We present numerical ab initio studies for time evolution of the vacuum state into multiple pair states. The high intensity laser field of two counter-propagating beams is treated classically and in the non-perturbative regime (E{sub 0}/ω ∝ 1). In this regime, the time needed by an electron to become relativistic in presence of a static field E{sub 0} is of same order as the period of the laser field. Pair state probabilities as well as correlations are investigated in real-time depending on polarization and field strength.

  15. Occupational exposure of healthcare and research staff to static magnetic stray fields from 1.5–7 Tesla MRI scanners is associated with reporting of transient symptoms

    Science.gov (United States)

    Schaap, Kristel; Christopher-de Vries, Yvette; Mason, Catherine K; de Vocht, Frank; Portengen, Lützen; Kromhout, Hans

    2014-01-01

    Objectives Limited data is available about incidence of acute transient symptoms associated with occupational exposure to static magnetic stray fields from MRI scanners. We aimed to assess the incidence of these symptoms among healthcare and research staff working with MRI scanners, and their association with static magnetic field exposure. Methods We performed an observational study among 361 employees of 14 clinical and research MRI facilities in The Netherlands. Each participant completed a diary during one or more work shifts inside and/or outside the MRI facility, reporting work activities and symptoms (from a list of potentially MRI-related symptoms, complemented with unrelated symptoms) experienced during a working day. We analysed 633 diaries. Exposure categories were defined by strength and type of MRI scanner, using non-MRI shifts as the reference category for statistical analysis. Non-MRI shifts originated from MRI staff who also participated on MRI days, as well as CT radiographers who never worked with MRI. Results Varying per exposure category, symptoms were reported during 16–39% of the MRI work shifts. We observed a positive association between scanner strength and reported symptoms among healthcare and research staff working with closed-bore MRI scanners of 1.5 Tesla (T) and higher (1.5 T OR=1.88; 3.0 T OR=2.14; 7.0 T OR=4.17). This finding was mainly driven by reporting of vertigo and metallic taste. Conclusions The results suggest an exposure-response association between exposure to strong static magnetic fields (and associated motion-induced time-varying magnetic fields) and reporting of transient symptoms on the same day of exposure. Trial registration number 11-032/C PMID:24714654

  16. Spontaneous violation of chiral symmetry in QCD vacuum is the origin of baryon masses and determines baryon magnetic moments and their other static properties

    International Nuclear Information System (INIS)

    Ioffe, B. L.

    2009-01-01

    A short review is presented of the spontaneous violation of chiral symmetry in QCD vacuum. It is demonstrated that this phenomenon is the origin of baryon masses in QCD. The value of nucleon mass is calculated, as well as the masses of hyperons and some baryonic resonances, and expressed mainly through the values of quark condensates - , q = u, d, s,-the vacuum expectation values (v.e.v.) of quark field. The concept of v.e.v. induced by external fields is introduced. It is demonstrated that such v.e.v. induced by static electromagnetic field results in quark condensate magnetic susceptibility, which plays the main role in determination of baryon magnetic moments. The magnetic moments of proton, neutron, and hyperons are calculated. The results of calculation of baryon octet β-decay constants are also presented.

  17. The association of trunk muscle cross-sectional area and magnetic resonance image parameters with isokinetic and psychophysical lifting strength and static back muscle endurance in men.

    Science.gov (United States)

    Gibbons, L E; Latikka, P; Videman, T; Manninen, H; Battié, M C

    1997-10-01

    The relationship between trunk muscle morphology as measured on transverse magnetic resonance images and isokinetic lifting, psychophysical lifting, and static back muscle endurance testing was examined in 110 men, ages 35-67 years (mean, 48 years), who had been chosen based on their exposure to a wide variety of occupational and leisure-time physical activities. The computed T2-relaxation times and the T2-weighted and proton density-weighted signal intensities of the erector spinae, quadratus lumborum, and psoas major muscles had almost no association with any of the strength tests. The cross-sectional areas of the muscles had good correlations with isokinetic lifting strength (r = 0.46-0.53). They did not correlate well with psychophysical lifting and static back muscle endurance. Other characteristics or neurological or psychological factors may have more influence on those tests.

  18. Osteogenic differentiation of MC3T3-E1 cells on poly(L-lactide)/Fe{sub 3}O{sub 4} nanofibers with static magnetic field exposure

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Qing [State Key Laboratory of Organic–inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029 (China); Shi, Yuzhou; Shan, Dingying; Jia, Wenkai; Duan, Shun [Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029 (China); Deng, Xuliang [Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081 (China); Yang, Xiaoping, E-mail: yangxp@mail.buct.edu.cn [State Key Laboratory of Organic–inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029 (China)

    2015-10-01

    Proliferation and differentiation of bone-related cells are modulated by many factors such as scaffold design, growth factor, dynamic culture system, and physical simulation. Nanofibrous structure and moderate-intensity (1 mT–1 T) static magnetic field (SMF) have been identified as capable of stimulating proliferation and differentiation of osteoblasts. Herein, magnetic nanofibers were prepared by electrospinning mixture solutions of poly(L-lactide) (PLLA) and ferromagnetic Fe{sub 3}O{sub 4} nanoparticles (NPs). The PLLA/Fe{sub 3}O{sub 4} composite nanofibers demonstrated homogeneous dispersion of Fe{sub 3}O{sub 4} NPs, and their magnetism depended on the contents of Fe{sub 3}O{sub 4} NPs. SMF of 100 mT was applied in the culture of MC3T3-E1 osteoblasts on pure PLLA and PLLA/Fe{sub 3}O{sub 4} composite nanofibers for the purpose of studying the effect of SMF on osteogenic differentiation of osteoblastic cells on magnetic nanofibrous scaffolds. On non-magnetic PLLA nanofibers, the application of external SMF could enhance the proliferation and osteogenic differentiation of MC3T3-E1 cells. In comparison with pure PLLA nanofibers, the incorporation of Fe{sub 3}O{sub 4} NPs could also promote the proliferation and osteogenic differentiation of MC3T3-E1 cells in the absence or presence of external SMF. The marriage of magnetic nanofibers and external SMF was found most effective in accelerating every aspect of biological behaviors of MC3T3-E1 osteoblasts. The findings demonstrated that the magnetic feature of substrate and microenvironment were applicable ways in regulating osteogenesis in bone tissue engineering. - Highlights: • Magnetic nanofibers containing well-dispersed Fe{sub 3}O{sub 4} nanoparticles were produced. • Static magnetic field (SMF) was applied to perform the culture of osteoblasts. • Osteogenic differentiation was enhanced on magnetic substrate with exposure to SMF.

  19. Development of high intensity beam handling system, 4

    International Nuclear Information System (INIS)

    Yamanoi, Yutaka; Tanaka, Kazuhiro; Minakawa, Michifumi

    1992-01-01

    We have constructed the new counter experimental hall at the KEK 12 GeV Proton Synchrotron (KEK-PS) in order to handle high intensity primary proton beams of up to 1x10 3 pps (protons per second), which is one order of magnitude greater than the present beam intensity of the KEK-PS, 1x10 12 pps. New technologies for handling high-intensity beams have, then, been developed and employed in the construction of the new hall. A part of our R/D work on handling high intensity beams will be reported. (author)

  20. ELECTRON CLOUD EFFECTS IN HIGH INTENSITY PROTON ACCELERATORS

    International Nuclear Information System (INIS)

    Wei, J.; Macek, R.J.

    2002-01-01

    One of the primary concerns in the design and operation of high-intensity proton synchrotrons and accumulators is the electron cloud and associated beam loss and instabilities. Electron-cloud effects are observed at high-intensity proton machines like the Los Alamos National Laboratory's PSR and CERN's SPS, and investigated experimentally and theoretically. In the design of next-generation high-intensity proton accelerators like the Spallation Neutron Source ring, emphasis is made in minimizing electron production and in enhancing Landau damping. This paper reviews the present understanding of the electron-cloud effects and presents mitigation measures

  1. ELECTRON CLOUD EFFECTS IN HIGH INTENSITY PROTON ACCELERATORS.

    Energy Technology Data Exchange (ETDEWEB)

    WEI,J.; MACEK,R.J.

    2002-04-14

    One of the primary concerns in the design and operation of high-intensity proton synchrotrons and accumulators is the electron cloud and associated beam loss and instabilities. Electron-cloud effects are observed at high-intensity proton machines like the Los Alamos National Laboratory's PSR and CERN's SPS, and investigated experimentally and theoretically. In the design of next-generation high-intensity proton accelerators like the Spallation Neutron Source ring, emphasis is made in minimizing electron production and in enhancing Landau damping. This paper reviews the present understanding of the electron-cloud effects and presents mitigation measures.

  2. Time-dependent change of blood flow in the prostate treated with high-intensity focused ultrasound.

    Science.gov (United States)

    Shoji, Sunao; Tonooka, Akiko; Hashimoto, Akio; Nakamoto, Masahiko; Tomonaga, Tetsuro; Nakano, Mayura; Sato, Haruhiro; Terachi, Toshiro; Koike, Junki; Uchida, Toyoaki

    2014-09-01

    Avascular areas on contrast-enhanced magnetic resonance imaging have been considered to be areas of localized prostate cancer successfully treated by high-intensity focused ultrasound. However, the optimal timing of magnetic resonance imaging has not been discussed. The thermal effect of high-intensity focused ultrasound is degraded by regional prostatic blood flow. Conversely, the mechanical effect of high-intensity focused ultrasound (cavitation) is not affected by blood flow, and can induce vessel damage. In this series, the longitudinal change of blood flow on contrast-enhanced magnetic resonance imaging was observed from postoperative day 1 to postoperative day 14 in 10 patients treated with high-intensity focused ultrasound. The median rates of increase in the non-enhanced volume of the whole gland, transition zone and peripheral zone from postoperative day 1 to postoperative day 14 were 36%, 39%, and 34%, respectively. In another pathological analysis of the prostate tissue of 17 patients immediately after high-intensity focused ultrasound without neoadjuvant hormonal therapy, we observed diffuse coagulative degeneration and partial non-coagulative prostate tissue around arteries with vascular endothelial cell detachment. These observations on contrast-enhanced magnetic resonance imaging support a time-dependent change of the blood flow in the prostate treated with high-intensity focused ultrasound. Additionally, our pathological findings support the longitudinal changes of these magnetic resonance imaging findings. Further large-scale studies will investigate the most appropriate timing of contrast-enhanced magnetic resonance imaging for evaluation of the effectiveness of high-intensity focused ultrasound for localized prostate cancer. © 2014 The Japanese Urological Association.

  3. Synovitis assessed on static and dynamic contrast-enhanced magnetic resonance imaging and its association with pain in knee osteoarthritis

    DEFF Research Database (Denmark)

    Riis, Robert Gabriel Coumine; Gudbergsen, Henrik; Henriksen, Marius

    2016-01-01

    OBJECTIVES: To investigate the association between pain and peripatellar-synovitis on static and dynamic contrast-enhanced MRI in knee osteoarthritis. METHODS: In a cross-sectional setting, knee synovitis was assessed using 3-Tesla MRI and correlated with pain using the knee injury and osteoarthr......OBJECTIVES: To investigate the association between pain and peripatellar-synovitis on static and dynamic contrast-enhanced MRI in knee osteoarthritis. METHODS: In a cross-sectional setting, knee synovitis was assessed using 3-Tesla MRI and correlated with pain using the knee injury...

  4. Analytical solution for static and dynamic analysis of magnetically affected viscoelastic orthotropic double-layered graphene sheets resting on viscoelastic foundation

    Science.gov (United States)

    Jalaei, M. H.; Arani, A. Ghorbanpour

    2018-02-01

    By considering the small scale effect based on the nonlocal Eringen's theory, the static and dynamic analysis of viscoelastic orthotropic double-layered graphene sheets subjected to longitudinal magnetic field and mechanical load is investigated analytically. For this objective, first order shear deformation theory (FSDT) is proposed. The surrounding medium is simulated by visco-Pasternak foundation model in which damping, normal and transverse shear loads are taken into account. The governing equations of motion are obtained via energy method and Hamilton's principle which are then solved analytically by means of Navier's approach and Laplace inversion technique in the space and time domains, respectively. Through various parametric studies, the influences of the nonlocal parameter, structural damping, van der Waals (vdW) interaction, stiffness and damping coefficient of the foundation, magnetic parameter, aspect ratio and length to thickness ratio on the static and dynamic response of the nanoplates are examined. The results depict that when the vdW interaction is considered to be zero, the upper layer deflection reaches a maximum point whereas the lower layer deflection becomes zero. In addition, it is observed that with growing the vdW interaction, the effect of magnetic field on the deflection of the lower layer increases while this effect reduces for the upper layer deflection.

  5. The Effect of Static Magnetic Forces on Water Contents and Photosynthetic Pigments in Sweet Basil Ocimum basilicum L. (Lamiaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Taia, Wafaa K; Kotbi, Abeer M [Alexandria Univ., Faculty of Science, Botany Dept., Alexandria (Egypt); AlZahrani, Hassan S [Faculty of Science, King AbdulAziz Univ., Biology Dept., Jeddah (Saudi Arabia)

    2007-07-01

    Three different magnetic regimes; aerial, surface and buried; each with three different forces, have been used to investigate their effects on the water contents and photosynthetic pigments of sweet basil plants (Ocimum basilicum L.). Two groups of sweet basil seeds, Ocimum basilicum L. have been cultivated, one under normal conditions and the second has been subdivided into three portion (aerial, surface and buried) to examine the effect of different magnetic forces coming from the three directions on the resulted plants. At all directions of magnets, water contents have been significantly affected by the magnetic forces. Chlorophyll A and carotene contents have been affected, as well, according to the three magnetic forces coming from soil surface regime only. Chlorophyll B did not significantly affected by differences magnetic forces in the three regimes, but it is affected by magnetism wherever its direction or force. But all the photosynthetic pigments contents (Chlorophyll A, B and Carotenes) decreased significantly than the control in the three magnetic regimes., but without any effect according to differences in the magnetic force in the aerial and burried regimes of magnetism. It was concluded that magnetism affects both water absorption and retention , the most influenced regime was the aerial magnets followed by the surface and buried ones. This result can be interpreted by the ionization of water which makes water ions respond to magnetic forces. Photosynthetic pigments have been decreased significantly by the exposure to magnetic fields, irrespective to its direction or force and this may be due to the effect of magnetic fields on the reduction in plastids inside the cells. (author)

  6. The Effect of Static Magnetic Forces on Water Contents and Photosynthetic Pigments in Sweet Basil Ocimum basilicum L. (Lamiaceae)

    International Nuclear Information System (INIS)

    Taia, Wafaa K; Kotbi, Abeer M; AlZahrani, Hassan S

    2007-01-01

    Three different magnetic regimes; aerial, surface and buried; each with three different forces, have been used to investigate their effects on the water contents and photosynthetic pigments of sweet basil plants (Ocimum basilicum L.). Two groups of sweet basil seeds, Ocimum basilicum L. have been cultivated, one under normal conditions and the second has been subdivided into three portion (aerial, surface and buried) to examine the effect of different magnetic forces coming from the three directions on the resulted plants. At all directions of magnets, water contents have been significantly affected by the magnetic forces. Chlorophyll A and carotene contents have been affected, as well, according to the three magnetic forces coming from soil surface regime only. Chlorophyll B did not significantly affected by differences magnetic forces in the three regimes, but it is affected by magnetism wherever its direction or force. But all the photosynthetic pigments contents (Chlorophyll A, B and Carotenes) decreased significantly than the control in the three magnetic regimes., but without any effect according to differences in the magnetic force in the aerial and burried regimes of magnetism. It was concluded that magnetism affects both water absorption and retention , the most influenced regime was the aerial magnets followed by the surface and buried ones. This result can be interpreted by the ionization of water which makes water ions respond to magnetic forces. Photosynthetic pigments have been decreased significantly by the exposure to magnetic fields, irrespective to its direction or force and this may be due to the effect of magnetic fields on the reduction in plastids inside the cells. (author)

  7. Influence of static Jahn-Teller distortion on the magnetic excitation spectrum of PrO2: A synchrotron x-ray and neutron inelastic scattering study

    International Nuclear Information System (INIS)

    Webster, C. H.; Helme, L. M.; Boothroyd, A. T.; McMorrow, D. F.; Wilkins, S. B.; Detlefs, C.; Detlefs, B.; Bewley, R. I.; McKelvy, M. J.

    2007-01-01

    A synchrotron x-ray diffraction study of the crystallographic structure of PrO 2 in the Jahn-Teller distorted phase is reported. The distortion of the oxygen sublattice, which was previously ambiguous, is shown to be a chiral structure in which neighboring oxygen chains have opposite chiralities. A temperature dependent study of the magnetic excitation spectrum, probed by neutron inelastic scattering, is also reported. Changes in the energies and relative intensities of the crystal field transitions provide an insight into the interplay between the static and dynamic Jahn-Teller effects

  8. Electromagnetic characteristics and static torque of a solid salient poles synchronous motor computed by 3D-finite element method magnetics

    International Nuclear Information System (INIS)

    Popnikolova Radevska, Mirka; Cundev, Milan; Petkovska, Lidija

    2002-01-01

    In these paper is presented a methodology for numerical determination and complex analysis of the electromagnetic characteristics of the Solid Salient Poles Synchronous Motor, with rated data: 2.5 kW, 240 V and 1500 r.p.m.. A mathematical model and original algorithm for the nonlinear and iterative calculations by using Finite Element Method in 3D domain will be given. The program package FEM-3D will be used to perform automatically mesh generation of the finite elements in the 3D domain, calculation of the magnetic field distribution, as well as electromagnetic characteristics and Static torque in SSPSM. (Author)

  9. On the texture, phase and tensile properties of commercially pure Ti produced via selective laser melting assisted by static magnetic field.

    Science.gov (United States)

    Kang, Nan; Yuan, Hao; Coddet, Pierre; Ren, Zhongming; Bernage, Charles; Liao, Hanlin; Coddet, Christian

    2017-01-01

    Tensile strength and ductility of Selective Laser Melting (SLM) processed commercially pure Ti (CP-Ti) were simultaneous enhanced by preforming the melting/solidification processes under Static Magnetic Field (SMF). The effects of SMF on microstructure and tensile properties were examined. The SMF-SLMed CP-Ti sample presents a microstructure of fine acicular martensitic α'-Ti and lath-shaped α-Ti. Meanwhile, the texture structure of SLMed CP-Ti was eliminated after adding a SMF. The SMF-SLM process offers new avenues to ameliorate the microstructure and improve the mechanical properties of SLMed sample. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Magnetism of FF6.2/SiO2 nanocomposites as observed by static and dynamic probes

    International Nuclear Information System (INIS)

    Vejpravova, J.; Kornak, R.; Niznansky, D.; Haimann, K.; Maruszewski, K.

    2007-01-01

    We report on magnetic behavior of the electromagnetic compatibility (EMC) compound FF6.2 and composites prepared by the modified Stoeber method using FF6.2 as the magnetic ion-containing (Fe 2+ /Fe 3+ ) precursor. The composites were characterized by the X-ray diffraction analysis (XRD) and morphology of the magnetic powders was investigated by a scanning electron microscope (SEM) and a high resolution transmision electron microscope (HR TEM). Magnetic properties of the materials were studied by measurements of the magnetization, AC susceptibility and Moessbauer spectra

  11. Apparatus for controlled mixing in a high intensity mixer

    International Nuclear Information System (INIS)

    Crocker, Z.; Gupta, V.P.

    1982-01-01

    An apparatus and a process is disclosed for controlled mixing of a mixable material in a high intensity mixer. The system enables instantaneous, precise and continual monitoring of a batch in a high intensity mixer which heretofore could not be achieved. The process comprises the steps of feeding a batch of material into a high intensity mixer, agitating the batch in the mixer, monitoring batch temperature separately from mixer temperature and discharging the batch from the mixer when the batch temperature reaches a final predetermined level. The apparatus includes means for monitoring batch temperature in a high intensity mixer separately from mixer temperature, and means responsive to the batch temperature to discharge the batch when the batch temperature reaches a final predetermined level

  12. Feasibility of high-intensity training in asthma

    DEFF Research Database (Denmark)

    Tønnesen, Louise Lindhardt; Sørensen, E D; Hostrup, Morten

    2018-01-01

    Background: High-intensity interval training is an effective and popular training regime but its feasibility in untrained adults with asthma is insufficiently described. Objective: The randomized controlled trial 'EFFORT Asthma' explored the effects of behavioural interventions including high......-intensity interval training on clinical outcomes in nonobese sedentary adults with asthma. In this article we present a sub analysis of data aiming to evaluate if patients' pre-intervention levels of asthma control, FEV1, airway inflammation and airway hyperresponsiveness (AHR) predicted their training response...... to the high-intensity interval training program, measured as increase in maximal oxygen consumption (VO2max). Design: We used data from the EFFORT Asthma Study. Of the 36 patients randomized to the 8-week exercise intervention consisting of high-intensity training three times per week, 29 patients (45...

  13. Concept for a new high resolution high intensity diffractometer

    Energy Technology Data Exchange (ETDEWEB)

    Stuhr, U [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    A concept of a new time-of-flight powder-diffractometer for a thermal neutral beam tube at SINQ is presented. The design of the instrument optimises the contradictory conditions of high intensity and high resolution. The high intensity is achieved by using many neutron pulses simultaneously. By analysing the time-angle-pattern of the detected neutrons an assignment of the neutrons to a single pulse is possible. (author) 3 figs., tab., refs.

  14. Case Study on Justification: High Intensity Discharge Lamps. Annex II

    International Nuclear Information System (INIS)

    2016-01-01

    High intensity discharge lamps produce bright white light of a high intensity in an energy efficient manner. These lamps are typically used in large numbers in public and professional settings such as shops, warehouses, hotels and offices. They are also used in outdoor applications to illuminate streets, buildings, statues, flags and gardens and further as architectural lighting. They also have applications associated with film projection in cinemas, manufacture of semiconductors, fluorescence endoscopy and microscopy, schlieren photography, hologram projection, ultraviolet curing, sky beamers and car headlights. Some types of high intensity discharge lamp, as well as certain other consumer products for lighting, contain radioactive substances for functional reasons. The radionuclides that are typically incorporated into high intensity discharge lamps are 85 Kr and 232 Th. Given the wide range of uses, specific decisions on justification may be required for different applications. A small number of safety assessments for high intensity discharge lamps have been carried out and published. No published decisions at the national level specifically addressing the justification of the use of high intensity discharge lamps have been identified

  15. Effect of Static and Rotating Magnetic Fields on Low-Temperature Fabrication of InGaZnO Thin-Film Transistors.

    Science.gov (United States)

    Park, Jeong Woo; Tak, Young Jun; Na, Jae Won; Lee, Heesoo; Kim, Won-Gi; Kim, Hyun Jae

    2018-05-16

    We suggest thermal treatment with static magnetic fields (SMFs) or rotating magnetic fields (RMFs) as a new technique for the activation of indium-gallium-zinc oxide thin-film transistors (IGZO TFTs). Magnetic interactions between metal atoms in IGZO films and oxygen atoms in air by SMFs or RMFs can be expected to enhance metal-oxide (M-O) bonds, even at low temperature (150 °C), through attraction of metal and oxygen atoms having their magnetic moments aligned in the same direction. Compared to IGZO TFTs with only thermal treatment at 300 °C, IGZO TFTs under an RMF (1150 rpm) at 150 °C show superior or comparable characteristics: field-effect mobility of 12.68 cm 2 V -1 s -1 , subthreshold swing of 0.37 V dec -1 , and on/off ratio of 1.86 × 10 8 . Although IGZO TFTs under an SMF (0 rpm) can be activated at 150 °C, the electrical performance is further improved in IGZO TFTs under an RMF (1150 rpm). These improvements of IGZO TFTs under an RMF (1150 rpm) are induced by increases in the number of M-O bonds due to enhancement of the magnetic interaction per unit time as the rpm value increases. We suggest that this new process of activating IGZO TFTs at low temperature widens the choice of substrates in flexible or transparent devices.

  16. Non-invasive modulation of somatosensory evoked potentials by the application of static magnetic fields over the primary and supplementary motor cortices.

    Science.gov (United States)

    Kirimoto, Hikari; Asao, Akihiko; Tamaki, Hiroyuki; Onishi, Hideaki

    2016-10-04

    This study was performed to investigate the possibility of non-invasive modulation of SEPs by the application of transcranial static magnetic field stimulation (tSMS) over the primary motor cortex (M1) and supplementary motor cortex (SMA), and to measure the strength of the NdFeB magnetic field by using a gaussmeter. An NdFeB magnet or a non-magnetic stainless steel cylinder (for sham stimulation) was settled on the scalp over M1 and SMA of 14 subjects for periods of 15 min. SEPs following right median nerve stimulation were recorded before and immediately after, 5 min after, and 10 min after tSMS from sites C3' and F3. Amplitudes of the N33 component of SEPs at C3' significantly decreased immediately after tSMS over M1 by up to 20%. However, tSMS over the SMA did not affect the amplitude of any of the SEP components. At a distance of 2-3 cm (rough depth of the cortex), magnetic field strength was in the range of 110-190 mT. Our results that tSMS over M1 can reduce the amplitude of SEPs are consistent with those of low-frequency repeated TMS and cathodal tDCS studies. Therefore, tSMS could be a useful tool for modulating cortical somatosensory processing.

  17. High intensity focused ultrasound treatment of small renal masses: Clinical effectiveness and technological advances

    Science.gov (United States)

    Nabi, G.; Goodman, C.; Melzer, A.

    2010-01-01

    The review summarises the technological advances in the application of high-intensity focused ultrasound for small renal masses presumed to be cancer including the systematic review of its clinical application. Current progress in the area of magnetic resonance image guided ultrasound ablation is also appraised. Specifically, organ tracking and real time monitoring of temperature changes during the treatment are discussed. Finally, areas of future research interest are outlined. PMID:21116349

  18. High intensity focused ultrasound treatment of small renal masses: Clinical effectiveness and technological advances

    OpenAIRE

    Nabi, G.; Goodman, C.; Melzer, A.

    2010-01-01

    The review summarises the technological advances in the application of high-intensity focused ultrasound for small renal masses presumed to be cancer including the systematic review of its clinical application. Current progress in the area of magnetic resonance image guided ultrasound ablation is also appraised. Specifically, organ tracking and real time monitoring of temperature changes during the treatment are discussed. Finally, areas of future research interest are outlined.

  19. Experimental Platform for measuring the parameters of magnetization of a transformer in a quasi-static transitional regime

    International Nuclear Information System (INIS)

    Milovanski, Vasil; , Blagoevgrad (Bulgaria))" data-affiliation=" (HMS “Acad. S. P. Corolov, Blagoevgrad (Bulgaria))" >Stoyanov, Krasimir; Milovanska, Stefani

    2013-01-01

    Some opportunities for development of an experimental module for magnetic research have been examined in the current paper. The goal is to attain a more accurate reading of the measured electrical signals which are directly related to the magnetic parameters and characteristics of the ferromagnetic material

  20. Phenomenon of the time-reversal violating magnetic field generation by a static electric field in a medium and vacuum

    OpenAIRE

    Baryshevsky, Vladimir G.

    1999-01-01

    It is shown that the T- and P-odd weak interactions yield to the existence of both electric field and magnetic (directed along the electric field) field around an electric charge. Similarly the assotiated magnetic field is directed along the vector of strength of stationary gravitational field.

  1. Static and high-frequency magnetic properties of stripe domain structure in a plate of finite sizes

    International Nuclear Information System (INIS)

    Mal'ginova, S.D.; Doroshenko, R.A.; Shul'ga, N.V.

    2006-01-01

    A model that enables to carry out self-consistent calculations of the main parameters of stripe domain structure (DS) and at the same time those of properties of domain walls (DW) of a multiple-axis finite (in all directions) ferromagnet depending on the sizes of a sample, material parameters and intensity of a magnetic field is offered. The calculations of the properties of DS (direction of magnetization in domains, widths, ferromagnetic resonance, etc.) are carried out on a computer for plates (1 1 0), rectangular shapes of a cubic ferromagnet with axes of light magnetization along trigonal directions in a magnetic field [-1 1 0]. It is shown, that in plates of different shapes there can be a structure with Neel DW alongside with DS with Bloch DW. Their features are noticeably exhibited, in particular, in different dependence of the number of domains, and also frequencies of a ferromagnetic resonance from a magnetic field

  2. Photon-photon scattering at the high-intensity frontier

    Science.gov (United States)

    Gies, Holger; Karbstein, Felix; Kohlfürst, Christian; Seegert, Nico

    2018-04-01

    The tremendous progress in high-intensity laser technology and the establishment of dedicated high-field laboratories in recent years have paved the way towards a first observation of quantum vacuum nonlinearities at the high-intensity frontier. We advocate a particularly prospective scenario, where three synchronized high-intensity laser pulses are brought into collision, giving rise to signal photons, whose frequency and propagation direction differ from the driving laser pulses, thus providing various means to achieve an excellent signal to background separation. Based on the theoretical concept of vacuum emission, we employ an efficient numerical algorithm which allows us to model the collision of focused high-intensity laser pulses in unprecedented detail. We provide accurate predictions for the numbers of signal photons accessible in experiment. Our study is the first to predict the precise angular spread of the signal photons, and paves the way for a first verification of quantum vacuum nonlinearity in a well-controlled laboratory experiment at one of the many high-intensity laser facilities currently coming online.

  3. Thin yttrium iron garnet films grown by pulsed laser deposition: Crystal structure, static, and dynamic magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, N. S., E-mail: nsokolov@fl.ioffe.ru; Fedorov, V. V.; Korovin, A. M.; Suturin, S. M.; Baranov, D. A.; Gastev, S. V.; Krichevtsov, B. B.; Bursian, V. E.; Lutsev, L. V. [Ioffe Physical-Technical Institute of Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation); Maksimova, K. Yu.; Grunin, A. I. [Immanuel Kant Baltic Federal University, Kaliningrad 236041 (Russian Federation); Tabuchi, M. [Synchrotron Radiation Research Center, Nagoya University, Nagoya 464-8603 (Japan)

    2016-01-14

    Pulsed laser deposition has been used to grow thin (10–84 nm) epitaxial layers of Yttrium Iron Garnet Y{sub 3}Fe{sub 5}O{sub 12} (YIG) on (111)–oriented Gadolinium Gallium Garnet substrates at different growth conditions. Atomic force microscopy showed flat surface morphology both on micrometer and nanometer scales. X-ray diffraction measurements revealed that the films are coherent with the substrate in the interface plane. The interplane distance in the [111] direction was found to be by 1.2% larger than expected for YIG stoichiometric pseudomorphic film indicating presence of rhombohedral distortion in this direction. Polar Kerr effect and ferromagnetic resonance measurements showed existence of additional magnetic anisotropy, which adds to the demagnetizing field to keep magnetization vector in the film plane. The origin of the magnetic anisotropy is related to the strain in YIG films observed by XRD. Magneto-optical Kerr effect measurements revealed important role of magnetization rotation during magnetization reversal. An unusual fine structure of microwave magnetic resonance spectra has been observed in the film grown at reduced (0.5 mTorr) oxygen pressure. Surface spin wave propagation has been demonstrated in the in-plane magnetized films.

  4. Thin yttrium iron garnet films grown by pulsed laser deposition: Crystal structure, static, and dynamic magnetic properties

    International Nuclear Information System (INIS)

    Sokolov, N. S.; Fedorov, V. V.; Korovin, A. M.; Suturin, S. M.; Baranov, D. A.; Gastev, S. V.; Krichevtsov, B. B.; Bursian, V. E.; Lutsev, L. V.; Maksimova, K. Yu.; Grunin, A. I.; Tabuchi, M.

    2016-01-01

    Pulsed laser deposition has been used to grow thin (10–84 nm) epitaxial layers of Yttrium Iron Garnet Y 3 Fe 5 O 12 (YIG) on (111)–oriented Gadolinium Gallium Garnet substrates at different growth conditions. Atomic force microscopy showed flat surface morphology both on micrometer and nanometer scales. X-ray diffraction measurements revealed that the films are coherent with the substrate in the interface plane. The interplane distance in the [111] direction was found to be by 1.2% larger than expected for YIG stoichiometric pseudomorphic film indicating presence of rhombohedral distortion in this direction. Polar Kerr effect and ferromagnetic resonance measurements showed existence of additional magnetic anisotropy, which adds to the demagnetizing field to keep magnetization vector in the film plane. The origin of the magnetic anisotropy is related to the strain in YIG films observed by XRD. Magneto-optical Kerr effect measurements revealed important role of magnetization rotation during magnetization reversal. An unusual fine structure of microwave magnetic resonance spectra has been observed in the film grown at reduced (0.5 mTorr) oxygen pressure. Surface spin wave propagation has been demonstrated in the in-plane magnetized films

  5. The influence of a static magnetic field on the behavior of a quantum mechanical model of matter

    Czech Academy of Sciences Publication Activity Database

    Vlachová Hutová, E.; Bartušek, Karel; Dohnal, P.; Fiala, P.

    2017-01-01

    Roč. 96, JAN (2017), s. 18-23 ISSN 0263-2241 R&D Projects: GA ČR GA13-09086S; GA MŠk(CZ) LO1212 Institutional support: RVO:68081731 Keywords : magnetic field * external magnetic field * Maxwell equations * biological sample Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect) Impact factor: 2.359, year: 2016

  6. Quasi-static three-dimensional magnetic field evolution in solar active region NOAA 11166 associated with an X1.5 flare

    International Nuclear Information System (INIS)

    Vemareddy, P.; Wiegelmann, T.

    2014-01-01

    We study the quasi-static evolution of coronal magnetic fields constructed from the non-linear force-free field (NLFFF) approximation aiming to understand the relation between the magnetic field topology and ribbon emission during an X1.5 flare in active region (AR) NOAA 11166. The flare with a quasi-elliptical and two remote ribbons occurred on 2011 March 9 at 23:13 UT over a positive flux region surrounded by negative flux at the center of the bipolar AR. Our analysis of the coronal magnetic structure with potential and NLFFF solutions unveiled the existence of a single magnetic null point associated with a fan-spine topology and is co-spatial with the hard X-ray source. The footpoints of the fan separatrix surface agree with the inner edge of the quasi-elliptical ribbon and the outer spine is linked to one of the remote ribbons. During the evolution, the slow footpoint motions stressed the field lines along the polarity inversion line and caused electric current layers in the corona around the fan separatrix surface. These current layers trigger magnetic reconnection as a consequence of dissipating currents, which are visible as cusp-shaped structures at lower heights. The reconnection process reorganized the magnetic field topology whose signatures are observed at the separatrices/quasi-separatrix layer structure in both the photosphere and the corona during the pre-to-post flare evolution. In agreement with previous numerical studies, our results suggest that the line-tied footpoint motions perturb the fan-spine system and cause null point reconnection, which eventually causes the flare emission at the footpoints of the field lines.

  7. Simultaneous monitoring of singlet and triplet exciton variations in solid organic semiconductors driven by an external static magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Baofu, E-mail: b.ding@ecu.edu.au; Alameh, Kamal, E-mail: k.alameh@ecu.edu.au [Electron Science Research Institute, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA 6027 (Australia)

    2014-07-07

    The research field of organic spintronics has remarkably and rapidly become a promising research area for delivering a range of high-performance devices, such as magnetic-field sensors, spin valves, and magnetically modulated organic light emitting devices (OLEDs). Plenty of microscopic physical and chemical models based on exciton or charge interactions have been proposed to explain organic magneto-optoelectronic phenomena. However, the simultaneous observation of singlet- and triplet-exciton variations in an external magnetic field is still unfeasible, preventing a thorough theoretical description of the spin dynamics in organic semiconductors. Here, we show that we can simultaneously observe variations of singlet excitons and triplet excitons in an external magnetic field, by designing an OLED structure employing a singlet-exciton filtering and detection layer in conjunction with a separate triplet-exciton detection layer. This OLED structure enables the observation of a Lorentzian and a non-Lorentzian line-shape magnetoresponse for singlet excitons and triplet excitons, respectively.

  8. Simultaneous monitoring of singlet and triplet exciton variations in solid organic semiconductors driven by an external static magnetic field

    International Nuclear Information System (INIS)

    Ding, Baofu; Alameh, Kamal

    2014-01-01

    The research field of organic spintronics has remarkably and rapidly become a promising research area for delivering a range of high-performance devices, such as magnetic-field sensors, spin valves, and magnetically modulated organic light emitting devices (OLEDs). Plenty of microscopic physical and chemical models based on exciton or charge interactions have been proposed to explain organic magneto-optoelectronic phenomena. However, the simultaneous observation of singlet- and triplet-exciton variations in an external magnetic field is still unfeasible, preventing a thorough theoretical description of the spin dynamics in organic semiconductors. Here, we show that we can simultaneously observe variations of singlet excitons and triplet excitons in an external magnetic field, by designing an OLED structure employing a singlet-exciton filtering and detection layer in conjunction with a separate triplet-exciton detection layer. This OLED structure enables the observation of a Lorentzian and a non-Lorentzian line-shape magnetoresponse for singlet excitons and triplet excitons, respectively.

  9. Variational principles for the static electric and magnetic polarizabilities of anisotropic media with perfect electric conductor inclusions

    International Nuclear Information System (INIS)

    Sjoeberg, Daniel

    2009-01-01

    We present four variational principles for the electric and magnetic polarizabilities for a structure consisting of anisotropic media with perfect electric conductor (PEC) inclusions. From these principles, we derive monotonicity results and upper and lower bounds on the electric and magnetic polarizabilities. When computing the polarizabilities numerically, the bounds can be used as error bounds. The variational principles demonstrate important differences between electrostatics and magnetostatics when PEC bodies are present.

  10. Transverse Beam Halo Measurements at High Intensity Neutrino Source (HINS) using Vibrating Wire Monitor

    Energy Technology Data Exchange (ETDEWEB)

    Chung, M.; Hanna, B.; Scarpine, V.; Shiltsev, V.; Steimel, J.; Artinian, S.; Arutunian, S.

    2015-02-26

    The measurement and control of beam halos will be critical for the applications of future high-intensity hadron linacs. In particular, beam profile monitors require a very high dynamic range when used for the transverse beam halo measurements. In this study, the Vibrating Wire Monitor (VWM) with aperture 60 mm was installed at the High Intensity Neutrino Source (HINS) front-end to measure the transverse beam halo. A vibrating wire is excited at its resonance frequency with the help of a magnetic feedback loop, and the vibrating and sensitive wires are connected through a balanced arm. The sensitive wire is moved into the beam halo region by a stepper motor controlled translational stage. We study the feasibility of the vibrating wire for the transverse beam halo measurements in the low-energy front-end of the proton linac.

  11. Approach to a very high intensity beam at J-PARC

    International Nuclear Information System (INIS)

    Yamazaki, Y.

    2007-01-01

    The high-intensity, high-energy proton accelerator project, J-PARC, comprises the 400-MeV proton linac, the 3-GeV, 1-MW Rapid-Cycling Synchrotron (RCS) and the 50-GeV Marin Ring (MR) Synchrotron. The secondary particles such as neutrons, muons, Kaons, neutrinos and so forth will be fully made use of for materials science, life science, nuclear physics, and particle physics. Even the industrial use of the neutrons and the nuclear energy application are incorporated in the project. The rationale for choosing the accelerator schemes are presented together with the present status of the project and research and development for the high-intensity, high-energy proton accelerators J-PARC. The development of the high-field gradient RF cavity system making use of the magnetic alloy (MA), which is really necessary for the future development of the high-power proton accelerators, is reported in detail. (author)

  12. Nonlinear behavior in high-intensity discharge lamps

    Science.gov (United States)

    Baumann, Bernd; Schwieger, Joerg; Wolff, Marcus; Manders, Freddy; Suijker, Jos

    2016-06-01

    The light flicker problem of high intensity discharge lamps is studied numerically and experimentally. It is shown that in some respects the systems behave very similar to the forced Duffing oscillator with a softening spring. In particular, the jump phenomenon and hysteresis are observed in the simulations and in the experiments.

  13. Influence of high intensity ultrasound with different probe diameter ...

    African Journals Online (AJOL)

    The main goal of this research is to analyze the influence of ultrasonic probe diameters (7 and 10 mm) of high-intensity ultrasound with constant frequency (30 kHz) on the degree of homogenization (variance) of cow milk. Influence of different probe diameters on the physical properties of cow milk was also tested. Changes ...

  14. Simulation study of the high intensity S-Band photoinjector

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiongwei; Nakajima, Kazuhisa [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

    2001-10-01

    In this paper, we report the results of simulation study of the high intensity S-Band photoinjector. The aim of the simulation study is to transport high bunch charge with low emittance evolution. The simulation result shows that 7nC bunch with rms emittance 22.3 {pi} mm mrad can be outputted at the exit of photoinjector. (author)

  15. Reuse Recycler: High Intensity Proton Stacking at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, P. [Fermilab

    2016-07-17

    After a successful career as an antiproton storage and cooling ring, Recycler has been converted to a high intensity proton stacker for the Main Injector. We discuss the commissioning and operation of the Recycler in this new role, and the progress towards the 700 kW design goal.

  16. The high intensity approximation applied to multiphoton ionization

    International Nuclear Information System (INIS)

    Brandi, H.S.; Davidovich, L.; Zagury, N.

    1980-08-01

    It is shown that the most commonly used high intensity approximations as applied to ionization by strong electromagnetic fields are related. The applicability of the steepest descent method in these approximations, and the relation between them and first-order perturbation theory, are also discussed. (Author) [pt

  17. Drift tube suspension for high intensity linear accelerators

    International Nuclear Information System (INIS)

    Clark, D.C.; Frank, J.A.; Liska, D.J.; Potter, R.C.; Schamaun, R.G.

    1982-01-01

    The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder

  18. Annotated bibliography on high-intensity linear accelerators

    International Nuclear Information System (INIS)

    Jameson, R.A.; Roybal, E.U.

    1978-01-01

    A technical bibliography covering subjects important to the design of high-intensity beam transport systems and linear accelerators is presented. Space charge and emittance growth are stressed. Subject and author concordances provide cross-reference to detailed citations, which include an abstract and notes on the material. The bibliography resides in a computer database that can be searched for key words and phrases

  19. Simulation study of the high intensity S-Band photoinjector

    International Nuclear Information System (INIS)

    Zhu, Xiongwei; Nakajima, Kazuhisa

    2001-01-01

    In this paper, we report the results of simulation study of the high intensity S-Band photoinjector. The aim of the simulation study is to transport high bunch charge with low emittance evolution. The simulation result shows that 7nC bunch with rms emittance 22.3 π mm mrad can be outputted at the exit of photoinjector. (author)

  20. High-intensity exercise and recovery during short-term ...

    African Journals Online (AJOL)

    to power athletes and other individuals wishing to improve performance in ... effect of creatine supplementation on physical performance. It has been reported that ... high-intensity work performance.1,2,5,16,31,36 Such activities as resistance ...

  1. High-Intensity Interval Training for Improving Postprandial Hyperglycemia

    Science.gov (United States)

    Little, Jonathan P.; Francois, Monique E.

    2014-01-01

    High-intensity interval training (HIIT) has garnered attention in recent years as a time-efficient exercise option for improving cardiovascular and metabolic health. New research demonstrates that HIIT may be particularly effective for improving postprandial hyperglycemia in individuals with, or at risk for, type 2 diabetes (T2D). These findings…

  2. Annotated bibliography on high-intensity linear accelerators. [240 citations

    Energy Technology Data Exchange (ETDEWEB)

    Jameson, R.A.; Roybal, E.U.

    1978-01-01

    A technical bibliography covering subjects important to the design of high-intensity beam transport systems and linear accelerators is presented. Space charge and emittance growth are stressed. Subject and author concordances provide cross-reference to detailed citations, which include an abstract and notes on the material. The bibliography resides in a computer database that can be searched for key words and phrases.

  3. Nonlinear behavior in high-intensity discharge lamps

    NARCIS (Netherlands)

    Baumann, Bernd; Schwieger, Joerg; Wolff, Marcus; Manders, Freddy; Suijker, Jos

    2016-01-01

    The light flicker problem of high intensity discharge lamps is studied numerically and experimentally. It is shown that in some respects the systems behave very similar to the forced Duffing oscillator with a softening spring. In particular, the jump phenomenon and hysteresis are observed in the

  4. Drift tube suspension for high intensity linear accelerators

    Science.gov (United States)

    Liska, Donald J.; Schamaun, Roger G.; Clark, Donald C.; Potter, R. Christopher; Frank, Joseph A.

    1982-01-01

    The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder.

  5. High-intensity exercise and recovery during short-term ...

    African Journals Online (AJOL)

    Objective. To determine the effect of short-term creatine supplementation plus a protein-carbohydrate formula on high-intensity exercise performance and recovery. Design. A repeated-measures, experimental study, employing a randomised, double-blind, placebo-controlled, group comparison design was used.

  6. Transient thermo-structural and static magnetic characteristics of 1:1 prototype JET ELM control coils

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, Ananya; Pradhan, Subrata, E-mail: pradhan@ipr.res.in; Ghate, Mahesh; Kanabar, Deven; Roy, Swati; Kumar, Nitish

    2017-01-15

    3D transient thermo-structural analyses and steady state magnetic field analyses of 1:1 prototyped JET Edge Localized Mode (ELM) coils have been carried out. Temperature distribution within the magnet winding as well as the temperature evolution have also been simulated as a function of pulsed transport currents in both large and small ELM coils as per the operational scenarios. The induced thermal stresses along with the shear stress components acting on the winding elements have also been analyzed. The deformations caused by thermal stresses have been calculated for the case, the conductor bundle and the insulation layers within the coils. In addition to thermo-structural analyses, steady state magnetic field analyses have also been carried out in the current carrying ELM coils. These values have been compared with the experimental values. The experimentally obtained values matches well with those obtained in simulations indicating that the prototyped ELM coils can operate successfully in JET operational scenarios. Additionally, the R & D and technologies developed in the context of JET ELM coils have also been validated with the magnet performances experimentally.

  7. Enantioselective Crystallization of Sodium Chlorate in the Presence of Racemic Hydrophobic Amino Acids and Static Magnetic Fields

    Directory of Open Access Journals (Sweden)

    María-Paz Zorzano

    2014-06-01

    Full Text Available We study the bias induced by a weak (200 mT external magnetic field on the preferred handedness of sodium chlorate crystals obtained by slow evaporation at ambient conditions of its saturated saline solution with 20 ppm of added racemic (dl hydrophobic amino acids. By applying the Fisher test to pairs of experiments with opposing magnetic field orientation we conclude, with a confidence level of 99.7%, that at the water-air interface of this saline solution there is an enantioselective magnetic interaction that acts upon racemic mixtures of hydrophobic chiral amino acids. This interaction has been observed with the three tested racemic hydrophobic amino acids: dl-Phe, dl-Try and dl-Trp, at ambient conditions and in spite of the ubiquitous chiral organic contamination. This enantioselective magnetic dependence is not observed when there is only one handedness of added chiral amino-acid, if the added amino acid is not chiral or if there is no additive. This effect has been confirmed with a double blind test. This novel experimental observation may have implications for our view of plausible initial prebiotic scenarios and of the roles of the geomagnetic field in homochirality in the biosphere.

  8. Magnetic resonance imaging. Recent studies on biological effects of static magnetic and high-frequency electromagnetic fields; Magnetresonanztomographie. Neuere Studien zur biologischen Wirkung statischer Magnetfelder und hochfrequenter elektromagnetischer Felder

    Energy Technology Data Exchange (ETDEWEB)

    Pophof, B. [Bundesamt fuer Strahlenschutz, Abteilung fuer Wirkungen und Risiken ionisierender und nichtionisierender Strahlung, Oberschleissheim/Neuherberg (Germany); Brix, G. [Bundesamt fuer Strahlenschutz, Abteilung fuer medizinischen und beruflichen Strahlenschutz, Oberschleissheim/Neuherberg (Germany)

    2017-07-15

    During the last few years, new studies on biological effects of strong static magnetic fields and on thermal effects of high-frequency electromagnetic fields used in magnetic resonance imaging (MRI) were published. Many of these studies have not yet been included in the current safety recommendations. Scientific publications since 2010 on biological effects of static and electromagnetic fields in MRI were researched and evaluated. New studies confirm older publications that have already described effects of static magnetic fields on sensory organs and the central nervous system, accompanied by sensory perceptions. A new result is the direct effect of Lorentz forces on ionic currents in the semicircular canals of the vestibular system. Recent studies of thermal effects of high-frequency electromagnetic fields were focused on the development of anatomically realistic body models and a more precise simulation of exposure scenarios. Strong static magnetic fields can cause unpleasant sensations, in particular, vertigo. In addition, they can influence the performance of the medical staff and thus potentially endanger the patient's safety. As a precaution, medical personnel should move slowly within the field gradient. High-frequency electromagnetic fields lead to an increase in the temperature of patients' tissues and organs. This should be considered especially in patients with restricted thermoregulation and in pregnant women and neonates; in these cases exposure should be kept as low as possible. (orig.) [German] In den letzten Jahren wurden neue Studien zu biologischen Wirkungen starker statischer Magnetfelder und zu thermischen Effekten hochfrequenter elektromagnetischer Feldern, wie sie bei der Magnetresonanztomographie (MRT) verwendet werden, publiziert. Viele dieser Studien sind noch nicht in aktuelle Sicherheitsempfehlungen eingeflossen. Wissenschaftliche Publikationen ab dem Jahr 2010 zur biologischen Wirkung statischer und elektromagnetischer Felder

  9. A framework for continuous target tracking during MR-guided high intensity focused ultrasound thermal ablations in the abdomen

    NARCIS (Netherlands)

    Zachiu, Cornel; Denis de Senneville, Baudouin; Dmitriev, Ivan D.; Moonen, Chrit T.W.; Ries, Mario

    2017-01-01

    Background: During lengthy magnetic resonance-guided high intensity focused ultrasound (MRg-HIFU) thermal ablations in abdominal organs, the therapeutic work-flow is frequently hampered by various types of physiological motion occurring at different time-scales. If left un-addressed this can lead to

  10. Performance of a static-anode/flat-panel x-ray fluoroscopy system in a diagnostic strength magnetic field: a truly hybrid x-ray/MR imaging system.

    Science.gov (United States)

    Fahrig, R; Wen, Z; Ganguly, A; DeCrescenzo, G; Rowlands, J A; Stevens, G M; Saunders, R F; Pelc, N J

    2005-06-01

    Minimally invasive procedures are increasing in variety and frequency, facilitated by advances in imaging technology. Our hybrid imaging system (GE Apollo flat panel, custom Brand x-ray static anode x-ray tube, GE Lunar high-frequency power supply and 0.5 T Signa SP) provides both x-ray and MR imaging capability to guide complex procedures without requiring motion of the patient between two distant gantries. The performance of the x-ray tube in this closely integrated system was evaluated by modeling and measuring both the response of the filament to an externally applied field and the behavior of the electron beam for field strengths and geometries of interest. The performance of the detector was assessed by measuring the slanted-edge modulation transfer function (MTF) and when placed at zero field and at 0.5 T. Measured resonant frequencies of filaments can be approximated using a modified vibrating beam model, and were at frequencies well below the 25 kHz frequency of our generator for our filament geometry. The amplitude of vibration was not sufficient to cause shorting of the filament during operation within the magnetic field. A simple model of electrons in uniform electric and magnetic fields can be used to estimate the deflection of the electron beam on the anode for the fields of interest between 0.2 and 0.5 T. The MTF measured at the detector and the DQE showed no significant difference inside and outside of the magnetic field. With the proper modifications, an x-ray system can be fully integrated with a MR system, with minimal loss of image quality. Any x-ray tube can be assessed for compatibility when placed at a particular location within the field using the models. We have also concluded that a-Si electronics are robust against magnetic fields. Detailed knowledge of the x-ray system installation is required to provide estimates of system operation.

  11. Performance of a static-anode/flat-panel x-ray fluoroscopy system in a diagnostic strength magnetic field: A truly hybrid x-ray/MR imaging system

    International Nuclear Information System (INIS)

    Fahrig, R.; Wen, Z.; Ganguly, A.; DeCrescenzo, G.; Rowlands, J.A.; Stevens, G.M.; Saunders, R.F.; Pelc, N.J.

    2005-01-01

    Minimally invasive procedures are increasing in variety and frequency, facilitated by advances in imaging technology. Our hybrid imaging system (GE Apollo TM flat panel, custom Brand x-ray static anode x-ray tube, GE Lunar high-frequency power supply and 0.5 T Signa SP TM ) provides both x-ray and MR imaging capability to guide complex procedures without requiring motion of the patient between two distant gantries. The performance of the x-ray tube in this closely integrated system was evaluated by modeling and measuring both the response of the filament to an externally applied field and the behavior of the electron beam for field strengths and geometries of interest. The performance of the detector was assessed by measuring the slanted-edge modulation transfer function (MTF) and when placed at zero field and at 0.5 T. Measured resonant frequencies of filaments can be approximated using a modified vibrating beam model, and were at frequencies well below the 25 kHz frequency of our generator for our filament geometry. The amplitude of vibration was not sufficient to cause shorting of the filament during operation within the magnetic field. A simple model of electrons in uniform electric and magnetic fields can be used to estimate the deflection of the electron beam on the anode for the fields of interest between 0.2 and 0.5 T. The MTF measured at the detector and the DQE showed no significant difference inside and outside of the magnetic field. With the proper modifications, an x-ray system can be fully integrated with a MR system, with minimal loss of image quality. Any x-ray tube can be assessed for compatibility when placed at a particular location within the field using the models. We have also concluded that a-Si electronics are robust against magnetic fields. Detailed knowledge of the x-ray system installation is required to provide estimates of system operation

  12. QUASI-STATIC FIELD ANALYSIS OF PERMANENT MAGNET GENERATOR USING H-HIERARCHICAL ADAPTIVE FINITE ELEMENT METHOD

    Directory of Open Access Journals (Sweden)

    CHETAN VASUDEVA

    2017-10-01

    Full Text Available Researchers have always shown keen interest in predetermining the electromagnetic field behavior inside an electrical machine at the design stage. Material properties of permanent magnet, selection of optimum air gap during the electromagnetic, thermal and structural design of generator are considered to be vital factors for an ideal machine. Generator output, heat rise, weight, and cost are a few of the characteristics which are directly influenced by the selection of the most advantageous material properties. Moreover, most theoretical studies have been conducted assuming that the air gap flux is sinusoidally distributed. The actual conduct of the air gap flux with the length of air gap and its impression on the performance of the generator has not been analyzed so far. In this paper, field analysis of permanent magnet generator using finite element method has been carried out to show the best material properties and air gap for optimum pattern.

  13. Static and high frequency magnetic properties of FeGa thin films deposited on convex flexible substrates

    International Nuclear Information System (INIS)

    Yu, Ying; Zhan, Qingfeng; Dai, Guohong; Zuo, Zhenghu; Zhang, Xiaoshan; Liu, Yiwei; Yang, Huali; Zhang, Yao; Wang, Baomin; Li, Run-Wei; Wei, Jinwu; Wang, Jianbo; Xie, Shuhong

    2015-01-01

    Magnetostrictive FeGa thin films were deposited on the bowed flexible polyethylene terephthalate (PET) substrates, which were fixed on the convex mold. A compressive stress was induced in FeGa films when the PET substrates were shaped from convex to flat. Due to the effect of magnetostriction, FeGa films exhibit an obvious in-plane uniaxial magnetic anisotropy which could be enhanced by increasing the applied pre-strains on the substrates during growth. Consequently, the ferromagnetic resonance frequency of the films was significantly increased, but the corresponding initial permeability was decreased. Moreover, the films with pre-strains less than 0.78% exhibit a working bandwidth of microwave absorption about 2 GHz. Our investigations demonstrated a convenient method via the pre-strained substrates to tune the high frequency properties of magnetic thin films which could be applied in flexible microwave devices

  14. Static and high frequency magnetic properties of FeGa thin films deposited on convex flexible substrates

    Science.gov (United States)

    Yu, Ying; Zhan, Qingfeng; Wei, Jinwu; Wang, Jianbo; Dai, Guohong; Zuo, Zhenghu; Zhang, Xiaoshan; Liu, Yiwei; Yang, Huali; Zhang, Yao; Xie, Shuhong; Wang, Baomin; Li, Run-Wei

    2015-04-01

    Magnetostrictive FeGa thin films were deposited on the bowed flexible polyethylene terephthalate (PET) substrates, which were fixed on the convex mold. A compressive stress was induced in FeGa films when the PET substrates were shaped from convex to flat. Due to the effect of magnetostriction, FeGa films exhibit an obvious in-plane uniaxial magnetic anisotropy which could be enhanced by increasing the applied pre-strains on the substrates during growth. Consequently, the ferromagnetic resonance frequency of the films was significantly increased, but the corresponding initial permeability was decreased. Moreover, the films with pre-strains less than 0.78% exhibit a working bandwidth of microwave absorption about 2 GHz. Our investigations demonstrated a convenient method via the pre-strained substrates to tune the high frequency properties of magnetic thin films which could be applied in flexible microwave devices.

  15. Half-integer resonance crossing in high-intensity rings

    Directory of Open Access Journals (Sweden)

    A. V. Fedotov

    2002-02-01

    Full Text Available A detailed study of the influence of space charge on the crossing of second-order resonances is presented and associated with the space-charge limit of high-intensity rings. Two-dimensional simulation studies are compared with envelope models, which agree in the finding of an increased intensity limit due to the coherent frequency shift. This result is also found for realistic bunched beams with multiturn injection painting. Characteristic features such as the influence of tune splitting, structure resonances, and the role of envelope instabilities are discussed in detail. The theoretical limits are found to be in good agreement with the performance of high-intensity proton machines.

  16. Chrome tannage using high-intensity ultrasonic field.

    Science.gov (United States)

    Mäntysalo, E; Marjoniemi, M; Kilpeläinen, M

    1997-04-01

    The process time in chrome tannage in leather making, using an elastic compression cycle followed by irradiation by high-intensity ultrasound, is quite short lasting only a few minutes, compared with a process time of several hours in modern chrome tannage. After ultrasonic irradiation, samples were basified in 17 h in chrome liquor at a pH of 4.0 and the shrinkage temperature was measured. The determination of the efficiency for the chrome liquor penetrating into the hides can be based on the steepness of the shrinkage temperature-processing time curve. An approximate value of 20 degrees C min(-1) can be evaluated for the initial slope of the curve when elastic compression and high-intensity ultrasonic irradiation is used, and a processing time of 2 min is required in chrome liquor (plus 17 h basification and 24 h storage time) to obtain leather stable to boiling. Usually, hides are kept in chrome liquor for 2 h.

  17. rf coaxial couplers for high-intensity linear accelerators

    International Nuclear Information System (INIS)

    Manca, J.J.; Knapp, E.A.

    1980-02-01

    Two rf coaxial couplers that are particularly suitable for intertank connection of the disk-and-washer accelerating structure for use in high-intensity linear accelerators have been developed. These devices have very high coupling to the accelerating structure and very low rf power loss at the operating frequency, and they can be designed for any relative particle velocity β > 0.4. Focusing and monitoring devices can be located inside these couplers

  18. Light and Light Sources High-Intensity Discharge Lamps

    CERN Document Server

    Flesch, Peter G

    2006-01-01

    Light and Light Sources gives an introduction to the working principles of high-intensity discharge (HID) lamps and points out challenges and problems associated with the development and operation of HID lamps. The state-of-the-art in electrode and plasma diagnostics as well as numerical methods used for the understanding of HID lamps are described. This volume addresses students as well as scientists and researchers at universities and in industry.

  19. Silicone rubber curing by high intensity infrared radiation

    International Nuclear Information System (INIS)

    Huang, T.; Tsai, J.; Cherng, C.; Chen, J.

    1994-01-01

    A high-intensity (12 kW) and compact (80 cm) infrared heating oven for fast curing (12 seconds) of tube-like silicone rubber curing studies is reported. Quality inspection by DSC and DMA and results from pilot-scale curing oven all suggest that infrared heating provides a better way of vulcanization regarding to curing time, quality, cost, and spacing over conventional hot air heating. copyright 1995 American Institute of Physics

  20. NUMERICAL METHODS FOR THE SIMULATION OF HIGH INTENSITY HADRON SYNCHROTRONS.

    Energy Technology Data Exchange (ETDEWEB)

    LUCCIO, A.; D' IMPERIO, N.; MALITSKY, N.

    2005-09-12

    Numerical algorithms for PIC simulation of beam dynamics in a high intensity synchrotron on a parallel computer are presented. We introduce numerical solvers of the Laplace-Poisson equation in the presence of walls, and algorithms to compute tunes and twiss functions in the presence of space charge forces. The working code for the simulation here presented is SIMBAD, that can be run as stand alone or as part of the UAL (Unified Accelerator Libraries) package.

  1. Pulsed Power Applications in High Intensity Proton Rings

    CERN Document Server

    Zhang, Wu; Ducimetière, Laurent; Fowler, Tony; Kawakubo, Tadamichi; Mertens, Volker; Sandberg, Jon; Shirakabe, Yoshihisa

    2005-01-01

    The pulsed power technology has been applied in particle accelerators and storage rings for over four decades. It is most commonly used in injection, extraction, beam manipulation, source, and focusing systems. These systems belong to the class of repetitive pulsed power. In this presentation, we review and discuss the history, present status, and future challenge of pulsed power applications in high intensity proton accelerators and storage rings.

  2. Proton induction linacs as high-intensity neutron sources

    International Nuclear Information System (INIS)

    Keefe, D.; Hoyer, E.

    1981-01-01

    Proton induction linacs are explored as high intensity neutron sources. The induction linac - concept, properties, experience with electrons, and possibilities - and its limitations for accelerating ions are reviewed. A number of proton induction linac designs are examined with the LIACEP program and general conclusions are given. Results suggest that a proton induction accelerator of the lowest voltage, consistent with good neutron flux, is preferred and could well be cost competitive with the usual rf linac/storage ring designs. (orig.)

  3. High intensity proton linear accelerator development for nuclear waste transmutation

    International Nuclear Information System (INIS)

    Mizumoto, M.; Hasegawa, K.; Oguri, H.; Ito, N.; Kusano, J.; Okumura, Y.; Murata, H.; Sakogawa, K.

    1997-01-01

    A high-intensity proton linear accelerator with an energy of 1.5 GeV and an average current of 10 mA has been proposed for various engineering tests for the transmutation system of nuclear waste by JAERI. The conceptual and optimization studies for this accelerator performed for a proper choice of operating frequency, high b structure, mechanical engineering considerations and RF source aspects are briefly described

  4. CW high intensity non-scaling FFAG proton drivers

    OpenAIRE

    Johnstone, C.; Berz, M.; Makino, K.; Snopok, P.

    2012-01-01

    Accelerators are playing increasingly important roles in basic science, technology, and medicine including nuclear power, industrial irradiation, material science, and neutrino production. Proton and light-ion accelerators in particular have many research, energy and medical applications, providing one of the most effective treatments for many types of cancer. Ultra high-intensity and high-energy (GeV) proton drivers are a critical technology for accelerator-driven sub-critical reactors (ADS)...

  5. Evidence based exercise - clinical benefits of high intensity interval training.

    Science.gov (United States)

    Shiraev, Tim; Barclay, Gabriella

    2012-12-01

    Aerobic exercise has a marked impact on cardiovascular disease risk. Benefits include improved serum lipid profiles, blood pressure and inflammatory markers as well as reduced risk of stroke, acute coronary syndrome and overall cardiovascular mortality. Most exercise programs prescribed for fat reduction involve continuous, moderate aerobic exercise, as per Australian Heart Foundation clinical guidelines. This article describes the benefits of exercise for patients with cardiovascular and metabolic disease and details the numerous benefits of high intensity interval training (HIIT) in particular. Aerobic exercise has numerous benefits for high-risk populations and such benefits, especially weight loss, are amplified with HIIT. High intensity interval training involves repeatedly exercising at a high intensity for 30 seconds to several minutes, separated by 1-5 minutes of recovery (either no or low intensity exercise). HIT is associated with increased patient compliance and improved cardiovascular and metabolic outcomes and is suitable for implementation in both healthy and 'at risk' populations. Importantly, as some types of exercise are contraindicated in certain patient populations and HIIT is a complex concept for those unfamiliar to exercise, some patients may require specific assessment or instruction before commencing a HIIT program.

  6. Ion source and injection line for high intensity medical cyclotron

    Science.gov (United States)

    Jia, XianLu; Guan, Fengping; Yao, Hongjuan; Zhang, TianJue; Yang, Jianjun; Song, Guofang; Ge, Tao; Qin, Jiuchang

    2014-02-01

    A 14 MeV high intensity compact cyclotron, CYCIAE-14, was built at China Institute of Atomic Energy (CIAE). An injection system based on the external H- ion source was used on CYCIAE-14 so as to provide high intensity beam, while most positron emission tomography cyclotrons adopt internal ion source. A beam intensity of 100 μA/14 MeV was extracted from the cyclotron with a small multi-cusp H- ion source (CIAE-CH-I type) and a short injection line, which the H- ion source of 3 mA/25 keV H- beam with emittance of 0.3π mm mrad and the injection line of with only 1.2 m from the extraction of ion source to the medial plane of the cyclotron. To increase the extracted beam intensity of the cyclotron, a new ion source (CIAE-CH-II type) of 9.1 mA was used, with maximum of 500 μA was achieved from the cyclotron. The design and test results of the ion source and injection line optimized for high intensity acceleration will be given in this paper.

  7. Pulsed system for obtaining microdosimetric data with high intensity beams

    International Nuclear Information System (INIS)

    Zaider, M.; Dicello, J.F.; Hiebert, R.D.

    1977-01-01

    The use of heavy particle accelerators for radiation therapy requires high intensity beams in order to produce useful dose rates. The 800-MeV proton beam at LAMPF passes through different production targets to generate secondary pion beams. Conventional microdosimetric techniques are not applicable under these conditions because exceedingly high count rates result in detector damage, gas breakdown, and saturation effects in the electronics. We describe a new microdosimetric system developed at the Pion Biomedical Channel of LAMPF. The accelerator provides a variable low intensity pulse once every ten high intensity macropulses. The voltage on the detector is pulsed in coincidence with the low intensity pulse so that we were able to operate the detector under optimum data-taking conditions. A low noise two-stage preamplifier was built in connection with the pulsed mode operation. A comparison is made between data obtained in pulsed (high intensity beam) and unpulsed (low intensity beam) modes. The spectra obtained by the two methods agree within the experimental uncertainties

  8. Influence of inhomogeneous static magnetic field-exposure on patients with erosive gastritis: a randomized, self- and placebo-controlled, double-blind, single centre, pilot study.

    Science.gov (United States)

    Juhász, Márk; Nagy, Viktor L; Székely, Hajnal; Kocsis, Dorottya; Tulassay, Zsolt; László, János F

    2014-09-06

    This pilot study was devoted to the effect of static magnetic field (SMF)-exposure on erosive gastritis. The randomized, self- and placebo-controlled, double-blind, pilot study included 16 patients of the 2nd Department of Internal Medicine, Semmelweis University diagnosed with erosive gastritis. The instrumental analysis followed a qualitative (pre-intervention) assessment of the symptoms by the patient: lower heartburn (in the ventricle), upper heartburn (in the oesophagus), epigastric pain, regurgitation, bloating and dry cough. Medical diagnosis included a double-line upper panendoscopy followed by 30 min local inhomogeneous SMF-exposure intervention at the lower sternal region over the stomach with peak-to-peak magnetic induction of 3 mT and 30 mT m(-1) gradient at the target site. A qualitative (post-intervention) assessment of the same symptoms closed the examination. Sham- or SMF-exposure was used in a double-blind manner. The authors succeeded in justifying the clinically and statistically significant beneficial effect of the SMF- over sham-exposure on the symptoms of erosive gastritis, the average effect of inhibition was 56% by p = 0.001, n = 42 + 96. This pilot study was aimed to encourage gastroenterologists to test local, inhomogeneous SMF-exposure on erosive gastritis patients, so this intervention may become an evidence-based alternative or complementary method in the clinical use especially in cases when conventional therapy options are contraindicated. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  9. Production and study of high intensity discharges; Production et etude de decharges a forte intensite

    Energy Technology Data Exchange (ETDEWEB)

    Breton, C.; Charbon, J.; Hubert, P.; Vendryes, G.; Yvon, P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    High intensity discharges have been induced in a pyrex toroid filled with argon or deuterium at low pressure. An attempt was made to stabilise the ring of plasma by the joint action of a metal screen and a longitudinal magnetic field. Penetrating X-ray have been observed under certain conditions. (author) [French] Des decharges a forte intensite ont ete induites dans une tore en pyrex rempli d'argon ou de deuterium sous basse pression. On a cherche a stabiliser l'anneau de plasma par l'action conjuguee d'un champ magnetique longitudinal. Un rayon X penetrant a ete observe dans certaines conditions. (auteur)

  10. Production and study of high intensity discharges; Production et etude de decharges a forte intensite

    Energy Technology Data Exchange (ETDEWEB)

    Breton, C; Charbon, J; Hubert, P; Vendryes, G; Yvon, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    High intensity discharges have been induced in a pyrex toroid filled with argon or deuterium at low pressure. An attempt was made to stabilise the ring of plasma by the joint action of a metal screen and a longitudinal magnetic field. Penetrating X-ray have been observed under certain conditions. (author) [French] Des decharges a forte intensite ont ete induites dans une tore en pyrex rempli d'argon ou de deuterium sous basse pression. On a cherche a stabiliser l'anneau de plasma par l'action conjuguee d'un champ magnetique longitudinal. Un rayon X penetrant a ete observe dans certaines conditions. (auteur)

  11. The static pinch

    Energy Technology Data Exchange (ETDEWEB)

    Longmire, Conrad L [University of California, Los Alamos Scientific Laboratory, Los Alamos, NM (United States)

    1958-07-01

    In a pinch, the outward diffusion of plasma due to collisions can be balanced by the inward drift resulting from ExB, where E is the applied electric field and B the magnetic field. From the equation expressing the balance of these two effects, together with the pressure balance equation, one obtains the perpendicular conductivity, which is about one-half of the classical parallel conductivity. This result has been applied to the problem of a static pinch under the assumptions: 1) there is an applied longitudinal (B{sub z}) magnetic field; 2) the plasma is isothermal; 3) the solution depends only on the radial coordinate.

  12. Static and dynamic magnetic properties of B2 ordered Co2MnAl film epitaxially grown on GaAs

    International Nuclear Information System (INIS)

    Liu, Jihong; Qiao, Shuang

    2015-01-01

    Co 2 MnAl, considering its potential 100% spin polarization and high Curie temperature, is expected to be one of the most promising materials for realizing half metallicity. However, on the premise of high polarization, the optimization of the magnetic damping constant is directly determined the critical current density for spin torque transfer switching and also the stability of spin polarization for spin injection transfer, thus research on damping constant is also very important. In this paper, we have systematically investigated the magnetic damping constant in Co 2 MnAl film epitaxially grown on GaAs(100) substrate by FMR and TR-MOKE measurements, and found that the damping constant of 0.023 extracted by FMR is comparable with that of TR-MOKE at low field. While, considering field-dependent spin orientation, we think that the field-dependent damping constant deduced by TR-MOKE may provide important information for Co 2 MnAl/GaAs heterostructure and its potential application in spintronics. - Graphical abstract: Co 2 MnAl, considering its potential 100% spin polarization and high Curie temperature, is expected to be one of the most promising materials for realizing half metallicity. In this paper, we have successfully grown the B2-ordered Co 2 MnAl film on GaAs (100) substrate and systematically investigated the magnetic damping constant in Co 2 MnAl film epitaxially grown on GaAs(100) substrate by employing both FMR and TR-MOKE measurements. Our results show that the damping constant of 0.023 extracted by FMR is comparable with that of TR-MOKE at low field. However, considering field-dependent spin orientation, we think that the field-dependent damping constant deduced by TR-MOKE may be more useful for Co 2 MnAl/GaAs heterostructure and its possible application in spintronics. - Highlights: • B2 ordered Co 2 MnAl was successfully prepared and studied by LMOKE and ROT-MOKE. • Static magnetic measurements show clear cubic anisotropy with K C of 5.0 × 10 4

  13. Beam halo in high-intensity hadron linacs

    Energy Technology Data Exchange (ETDEWEB)

    Gerigk, F

    2006-12-21

    This document aims to cover the most relevant mechanisms for the development of beam halo in high-intensity hadron linacs. The introduction outlines the various applications of high-intensity linacs and it will explain why, in the case of the CERN Superconducting Proton Linac (SPL) study a linac was chosen to provide a high-power beam, rather than a different kind of accelerator. The basic equations, needed for the understanding of halo development are derived and employed to study the effects of initial and distributed mismatch on high-current beams. The basic concepts of the particle-core model, envelope modes, parametric resonances, the free-energy approach, and the idea of core-core resonances are introduced and extended to study beams in realistic linac lattices. The approach taken is to study the behavior of beams not only in simplified theoretical focusing structures but to highlight the beam dynamics in realistic accelerators. All effects which are described and derived with simplified analytic models, are tested in realistic lattices and are thus related to observable effects in linear accelerators. This approach involves the use of high-performance particle tracking codes, which are needed to simulate the behavior of the outermost particles in distributions of up to 100 million macro particles. In the end a set of design rules are established and their impact on the design of a typical high-intensity machine, the CERN SPL, is shown. The examples given in this document refer to two different design evolutions of the SPL study: the first conceptual design report (SPL I) and the second conceptual design report (SPL II). (orig.)

  14. Effect of seed treatment with static magnetic field (SMF) and low dose gamma radiation (GR) on grain yield of aerobic rice

    International Nuclear Information System (INIS)

    Kumar, Dinesh; Anand, Anjali; Singh, Bhupinder

    2014-01-01

    Aerobic rice cultivation is gaining popularity as it demands less water. However, poor germination of rice is an important issue in this situation. Seed pretreatment with static magnetic field (SMF) and gamma radiation (GR) at prescribed dose is known to influence the germination, seedling vigour and and yield of many crops. There is a possibility to improve the crop establishment under aerobic situation by physical seed treatment with static-magnetic field (SMF) and gamma radiation (GR) prior to sowing. Hence, a field experiment was conducted at the Indian Agricultural Research Institute, New Delhi during kharif 2012 and 2013 to study the effect of SMF and GR-treated seeds on growth and yield of aerobic rice. The five seed treatments were: SMF 50 mT for 2 hrs, SMF 100 mT for 2 hrs, GR 0.0025 kGy, GR 0.10 kGy and an untreated control. The experiment was laid out in a Randomized Block Design with four replications. Crop (variety 'Pusa Basmati-1121') was direct seeded on 25 th and 24 th June during 2012 and 2013, respectively at a spacing of 25 cm. Treatments GR 0.0025 kGy, SMF (50 mT) and SMF (100 mT) resulted in a significant improvement in grain yield of rice over control and GR dose (0.10 kGy) during both the years. Averaged across two years the grain yield increase by treating the rice seeds with GR 0.0025 kGy, SMF (50 mT) and SMF (100 mT) was 20.1, 17.6 and 14.5%, respectively over the control. Increase in GR dose (0.10 kGy ) was not effective in improving the yield, and was found to be similar to control. It is therefore concluded that treatment of rice seeds either with GR (0.0025 kGy) or SMF (50 mT) holds a great promise in increasing the grain yield of aerobic rice. (author)

  15. Proton and Ion Sources for High Intensity Accelerators

    CERN Multimedia

    Scrivens, R

    2004-01-01

    Future high intensity ion accelerators, including the Spallation Neutron Source (SNS), the European Spallation Source (ESS), the Superconducting Proton Linac (SPL) etc, will require high current and high duty factor sources for protons and negative hydrogen ions. In order to achieve these goals, a comparison of the Electron Cyclotron Resonance, radio-frequency and Penning ion sources, among others, will be made. For each of these source types, the present operational sources will be compared to the state-of-the-art research devices with special attention given to reliability and availability. Finally, the future research and development aims will be discussed.

  16. Nuclear diagnostics of high intensity laser plasma interactions

    International Nuclear Information System (INIS)

    Krushelnick, K.; Santala, M.I.K.; Beg, F.N.; Clark, E.L.; Dangor, A.E.; Tatarakis, M.; Watts, I.; Wei, M.S.; Zepf, M.; Ledingham, K.W.D.; McCanny, T.; Spencer, I.; Clarke, R.J.; Norreys, P.A.

    2002-01-01

    Nuclear activation has been observed in materials exposed to energetic protons and heavy ions generated from high intensity laser-solid interactions (at focused intensities up to 5x10 19 W/cm 2 ). The energy spectrum of the protons is determined through the use of these nuclear activation techniques and is found to be consistent with other ion diagnostics. Heavy ion fusion reactions and large neutron fluxes from the (p, n) reactions were also observed. The reduction of proton emission and increase in heavy ion energy using heated targets was also observed

  17. The joint project for high-intensity proton accelerators

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-08-01

    Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) agreed to promote the joint project integrating both the Neutron Science Project (NSP) of JAERI and the Japan Hadron Facility Project (JHF) of KEK for comprehensive studies on basic science and technology using high-intensity proton accelerator. This document describes the joint proposal prepared by the Joint Project Team of JAERI and KEK to construct accelerators and research facilities necessary both for the NSP and the JHF at the site of JAERI Tokai Establishment. (author)

  18. P-West High Intensity Secondary Beam Area Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Cox, A.; Currier, R.; Eartly, D.; Guthke, A.; Johnson, G.; Lee, D.; Dram, R.; Villegas, E.; Rest, J.; Tilles, E.; Vander Arend, P.

    1977-03-01

    This report gives the initial design parameters of a 1000 GeV High Intensity Superconducting Secondary Beam Laboratory to be situated in the Proton Area downstream of the existing Proton West experimental station. The area will provide Fermilab with a major capability for experimentation with pion and antiproton beams of intensities and of energies available at no other laboratory and with an electron beam with excellent spot size, intensity, and purity at energies far above that available at electron machines. Detailed beam design, area layouts, and cost estimates are presented, along with the design considerations.

  19. Summary for the WG4: physics with high intensity lasers

    International Nuclear Information System (INIS)

    Takahashi, T.

    2006-01-01

    There are many physics opportunities in laser-beam interactions and innovations in the laser- and the beam technologies expand them or even open new window in the field. Therefore, physics with high intense lasers is an attractive application of nanobeam technologies. The topics in the working group 4 covers fundamental physics based on technique related with nanobeam development aiming to encourage communication between physics and accelerator communities. Due to the limited time for the preparation, we did not try comprehensive coverage of the field but invited topics which are planed near future or can be studied at the ILC test facilities. (author)

  20. KEK/JAERI joint project on high intensity proton accelerators

    International Nuclear Information System (INIS)

    Nagamiya, Shoji

    2002-01-01

    From JFY01, which started on April 1, 2001, a new accelerator project to provide high-intensity proton beams proceeded into a construction phase. This project is conducted under a cooperation of two institutions, KEK and JAERI. The accelerator complex will provide 1 MW proton beams at 3 GeV and 0.75 MW beams at 50 GeV. The project will be completed within six years. In this article I will describe a) the project itself, b) sciences to be pursued at this new accelerator complex and c) the present status and future plans of the project. (author)

  1. JAERI-KEK joint project on high intensity proton accelerators

    International Nuclear Information System (INIS)

    Nagamiya, Shoji

    2000-01-01

    Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Organization (KEK) are promoting the joint project integrating both the Neutron Science Project (NSP) of JAERI and the Japan Hadron Facility Project (JHF) of KEK for comprehensive studies on basic science and technology using high-intensity proton accelerator. This paper describes the joint project prepared by the Joint Project Team of JAERI and KEK to construct accelerators and research facilities necessary both for the NSP and the JHF at the site of JAERI Tokai Establishment. (author)

  2. A high intensity positron beam at the Brookhaven reactor

    International Nuclear Information System (INIS)

    Weber, M.; Lynn, K.G.; Roellig, L.O.; Mills, A.P. Jr.; Moodenbaugh, A.R.

    1987-01-01

    We describe a high intensity, low energy positron beam utilizing high specific activity /sup 64/Cu sources (870 Ci/g) produced in a reactor with high thermal neutron flux. Fast-to-slow moderation can be performed in a self moderation mode or with a transmission moderator. Slow positron rates up to 1.6 x 10/sup 8/ e/sup +//s with a half life of 12.8 h are calculated. Up to 1.0 x 10/sup 8/ e/sup +//s have been observed. New developments including a Ne moderator and an on-line isotope separation process are discussed. 21 refs., 9 figs

  3. Performance of GEM detectors in high intensity particle beams

    CERN Document Server

    Bachmann, S; Ketzer, B; Deutel, M; Ropelewski, Leszek; Sauli, Fabio; Bondar, A E; Buzulutskov, A F; Shekhtman, L I; Sokolov, A; Tatarinov, A A; Vasilev, A; Kappler, S; Schulte, E C

    2001-01-01

    We describe extensive tests of Double GEM and Triple GEM detectors, including full size prototypes for the COMPASS experiment, exposed to high intensity muon, proton and pion beams at the Paul~Scherrer Institute and at CERN. The measurements aim at detecting problems possible under these operation conditions, the main concern being the occurrence of discharges induced by beam particles. Results on the dependence of the probability for induced discharges on the experimental environment are presented and discussed. Implications for the application of GEM~detectors in experiments at high luminosity colliders are illustrated.

  4. Ultra-High Intensity Proton Accelerators and their Applications

    International Nuclear Information System (INIS)

    Weng, W. T.

    1997-01-01

    The science and technology of proton accelerators have progressed considerably in the past three decades. Three to four orders of magnitude increase in both peak intensity and average flux have made it possible to construct high intensity proton accelerators for modern applications, such as: spallation neutron sources, kaon factory, accelerator production of tritium, energy amplifier and muon collider drivers. The accelerator design focus switched over from intensity for synchrotrons, to brightness for colliders to halos for spallation sources. An overview of this tremendous progress in both accelerator science and technology is presented, with special emphasis on the new challenges of accelerator physics issues such as: H(-) injection, halo formation and reduction of losses

  5. Multi-energy ion implantation from high-intensity laser

    Czech Academy of Sciences Publication Activity Database

    Cutroneo, Mariapompea; Torrisi, L.; Ullschmied, Jiří; Dudžák, Roman

    2016-01-01

    Roč. 61, č. 2 (2016), s. 109-113 ISSN 0029-5922. [PLASMA 2015 : International Conference on Research and Applications of Plasmas. Warsaw, 07.09.2015-11.09.2015] R&D Projects: GA MŠk(CZ) LM2011019; GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389021 ; RVO:61389005 Keywords : high-intensity laser * implantation * material modification Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders; BL - Plasma and Gas Discharge Physics (UFP-V) Impact factor: 0.760, year: 2016

  6. High intensity line source for x-ray spectrometer calibration

    International Nuclear Information System (INIS)

    Thoe, R.S.

    1986-06-01

    A high intensity electron-impact x-ray source using a one-dimensional Pierce lens has been built for the purpose of calibrating a bent crystal x-ray spectrometer. This source focuses up to 100 mA of 20-keV electrons to a line on a liquid-cooled anode. The line (which can serve as a virtual slit for the spectrometer) measures approximately 800 μ x 2 cm. The source is portable and therefore adaptable to numerous types of spectrometer applications. One particular application, the calibration of a high resolution (r = 10 4 ) time-resolved cyrstal spectrometer, will be discussed in detail

  7. Overview of high intensity proton accelerator facility, J-PARC

    International Nuclear Information System (INIS)

    Ikeda, Y.

    2010-01-01

    The J-PARC project of high intensity proton accelerator research complex, conducted jointly by JAERI and KEK, has been completed with demonstration of all beam productions in 2009 as the facility construction phase, and the operation started to offer the secondary beams of neutron, muon, kaon, and neutrino, to the advanced scientific experimental research aiming at making breakthroughs in materials and life science, nuclear and elementary physics, etc. This text describes the overview of the J-PARC present status with emphasis of a performance toward to 1MW power as user facilities. (author)

  8. ORBIT: A CODE FOR COLLECTIVE BEAM DYNAMICS IN HIGH INTENSITY RINGS

    International Nuclear Information System (INIS)

    HOLMES, J.A.; DANILOV, V.; GALAMBOS, J.; SHISHLO, A.; COUSINEAU, S.; CHOU, W.; MICHELOTTI, L.; OSTIGUY, J.F.; WEI, J.

    2002-01-01

    We are developing a computer code, ORBIT, specifically for beam dynamics calculations in high-intensity rings. Our approach allows detailed simulation of realistic accelerator problems. ORBIT is a particle-in-cell tracking code that transports bunches of interacting particles through a series of nodes representing elements, effects, or diagnostics that occur in the accelerator lattice. At present, ORBIT contains detailed models for strip-foil injection, including painting and foil scattering; rf focusing and acceleration; transport through various magnetic elements; longitudinal and transverse impedances; longitudinal, transverse, and three-dimensional space charge forces; collimation and limiting apertures; and the calculation of many useful diagnostic quantities. ORBIT is an object-oriented code, written in C++ and utilizing a scripting interface for the convenience of the user. Ongoing improvements include the addition of a library of accelerator maps, BEAMLINE/MXYZPTLK, the introduction of a treatment of magnet errors and fringe fields; the conversion of the scripting interface to the standard scripting language, Python; and the parallelization of the computations using MPI. The ORBIT code is an open source, powerful, and convenient tool for studying beam dynamics in high-intensity rings

  9. ORBIT: A Code for Collective Beam Dynamics in High-Intensity Rings

    Science.gov (United States)

    Holmes, J. A.; Danilov, V.; Galambos, J.; Shishlo, A.; Cousineau, S.; Chou, W.; Michelotti, L.; Ostiguy, J.-F.; Wei, J.

    2002-12-01

    We are developing a computer code, ORBIT, specifically for beam dynamics calculations in high-intensity rings. Our approach allows detailed simulation of realistic accelerator problems. ORBIT is a particle-in-cell tracking code that transports bunches of interacting particles through a series of nodes representing elements, effects, or diagnostics that occur in the accelerator lattice. At present, ORBIT contains detailed models for strip-foil injection, including painting and foil scattering; rf focusing and acceleration; transport through various magnetic elements; longitudinal and transverse impedances; longitudinal, transverse, and three-dimensional space charge forces; collimation and limiting apertures; and the calculation of many useful diagnostic quantities. ORBIT is an object-oriented code, written in C++ and utilizing a scripting interface for the convenience of the user. Ongoing improvements include the addition of a library of accelerator maps, BEAMLINE/MXYZPTLK; the introduction of a treatment of magnet errors and fringe fields; the conversion of the scripting interface to the standard scripting language, Python; and the parallelization of the computations using MPI. The ORBIT code is an open source, powerful, and convenient tool for studying beam dynamics in high-intensity rings.

  10. ORBIT: A code for collective beam dynamics in high-intensity rings

    International Nuclear Information System (INIS)

    Holmes, J.A.; Danilov, V.; Galambos, J.; Shishlo, A.; Cousineau, S.; Chou, W.; Michelotti, L.; Ostiguy, J.-F.; Wei, J.

    2002-01-01

    We are developing a computer code, ORBIT, specifically for beam dynamics calculations in high-intensity rings. Our approach allows detailed simulation of realistic accelerator problems. ORBIT is a particle-in-cell tracking code that transports bunches of interacting particles through a series of nodes representing elements, effects, or diagnostics that occur in the accelerator lattice. At present, ORBIT contains detailed models for strip-foil injection, including painting and foil scattering; rf focusing and acceleration; transport through various magnetic elements; longitudinal and transverse impedances; longitudinal, transverse, and three-dimensional space charge forces; collimation and limiting apertures; and the calculation of many useful diagnostic quantities. ORBIT is an object-oriented code, written in C++ and utilizing a scripting interface for the convenience of the user. Ongoing improvements include the addition of a library of accelerator maps, BEAMLINE/MXYZPTLK; the introduction of a treatment of magnet errors and fringe fields; the conversion of the scripting interface to the standard scripting language, Python; and the parallelization of the computations using MPI. The ORBIT code is an open source, powerful, and convenient tool for studying beam dynamics in high-intensity rings

  11. Low-frequency-high-intensity limit of the Keldysh-Faisal-Reiss theory

    International Nuclear Information System (INIS)

    Bauer, Jaroslaw

    2006-01-01

    When a frequency of the circularly polarized laser field approaches zero the above threshold ionization rate should approach the well-known static-field limit of tunneling ionization. In the high-intensity limit of the laser field the Keldysh-Faisal-Reiss (KFR) theory is expected to be valid. For the ground state of a hydrogen atom we study various forms of the KFR theory when both conditions: ω<<1 a.u. and γ<<1 (ω is the frequency and γ the Keldysh parameter) are satisfied. For the circularly polarized laser field ionization rate in the Keldysh theory [which utilizes the length gauge (d(vector sign)·E(vector sign)) form of the matrix element] is calculated analytically. We show numerically that if the WKB Coulomb correction in the final state of the ionized electron is included, the Keldysh theory gives the correct result in the tunneling domain. In the barrier-suppression regime the Keldysh theory without this correction gives ionization rates close to the exact static-field results. The Reiss theory [which utilizes the velocity gauge (p(vector sign)·A(vector sign)) form of the matrix element] leads to too small ionization rates in the limit ω→0, γ→0

  12. A transparent vacuum window for high-intensity pulsed beams

    CERN Document Server

    Monteil, M; Veness, R

    2011-01-01

    The HiRadMat (High-Radiation to Materials) facility Ill will allow testing of accelerator components, in particular those of the Large Hadron Collider (LHC) at CERN, under the impact of high-intensity pulsed beams. To reach this intensity range, the beam will be focused on a focal point where the target to be tested is located. A 60 mm aperture vacuum window will separate the vacuum of the beam line which is kept under high vacuum 10(-8) mbar, from the test area which is at atmospheric pressure. This window has to resist collapse due to beam passage. The high-intensity of the beam means that typical materials used for standard vacuum windows (such as stainless steel, aluminium and titanium alloy) cannot endure the energy deposition induced by the beam passage. Therefore, a vacuum window has been designed to maintain the differential pressure whilst resisting collapse due to the beam impact on the window. In this paper, we will present calculations of the energy transfer from beam to window, the design of the ...

  13. Injection and capture simulations for a high intensity proton synchrotron

    International Nuclear Information System (INIS)

    Cho, Y.; Lessner, E.; Symon, K.; Univ. of Wisconsin, Madison, WI

    1994-01-01

    The injection and capture processes in a high intensity, rapid cycling, proton synchrotron are simulated by numerical integration. The equations of motion suitable for rapid numerical simulation are derived so as to maintain symplecticity and second-order accuracy. By careful bookkeeping, the authors can, for each particle that is lost, determine its initial phase space coordinates. They use this information as a guide for different injection schemes and rf voltage programming, so that a minimum of particle losses and dilution are attained. A fairly accurate estimate of the space charge fields is required, as they influence considerably the particle distribution and reduce the capture efficiency. Since the beam is represented by a relatively coarse ensemble of macro particles, the authors study several methods of reducing the statistical fluctuations while retaining the fine structure (high intensity modulations) of the beam distribution. A pre-smoothing of the data is accomplished by the cloud-in-cell method. The program is checked by making sure that it gives correct answers in the absence of space charge, and that it reproduces the negative mass instability properly. Results of simulations for stationary distributions are compared to their analytical predictions. The capture efficiency for the rapid-cycling synchrotron is analyzed with respect to variations in the injected beam energy spread, bunch length, and rf programming

  14. Gaussian representation of high-intensity focused ultrasound beams.

    Science.gov (United States)

    Soneson, Joshua E; Myers, Matthew R

    2007-11-01

    A method for fast numerical simulation of high-intensity focused ultrasound beams is derived. The method is based on the frequency-domain representation of the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation, and assumes for each harmonic a Gaussian transverse pressure distribution at all distances from the transducer face. The beamwidths of the harmonics are constrained to vary inversely with the square root of the harmonic number, and as such this method may be viewed as an extension of a quasilinear approximation. The technique is capable of determining pressure or intensity fields of moderately nonlinear high-intensity focused ultrasound beams in water or biological tissue, usually requiring less than a minute of computer time on a modern workstation. Moreover, this method is particularly well suited to high-gain simulations since, unlike traditional finite-difference methods, it is not subject to resolution limitations in the transverse direction. Results are shown to be in reasonable agreement with numerical solutions of the full KZK equation in both tissue and water for moderately nonlinear beams.

  15. Evaluation of oxidative response and tissular damage in rat lungs exposed to silica-coated gold nanoparticles under static magnetic fields

    Directory of Open Access Journals (Sweden)

    Ferchichi S

    2016-06-01

    Full Text Available Soumaya Ferchichi,1 Hamdi Trabelsi,1 Inès Azzouz,1 Amel Hanini,2 Ahmed Rejeb,3 Olfa Tebourbi,1 Mohsen Sakly,1 Hafedh Abdelmelek1 1Laboratory of Integrative Physiology, Faculty Of Sciences of Bizerte, 2Laboratory of Vascular Pathology, Carthage University, Carthage 3Laboratory of Pathological Anatomy, National School of Veterinary Medicine of Sidi Thabet, Manouba Univeristy, Manouba, Tunisia Abstract: The purpose of our study was the evaluation of toxicological effects of silica-coated gold nanoparticles (GNPs and static magnetic fields (SMFs; 128 mT exposure in rat lungs. Animals received a single injection of GNPs (1,100 µg/kg, 100 nm, intraperitoneally and were exposed to SMFs, over 14 days (1 h/day. Results showed that GNPs treatment induced a hyperplasia of bronchus-associated lymphoid tissue. Fluorescence microscopy images showed that red fluorescence signal was detected in rat lungs after 2 weeks from the single injection of GNPs. Oxidative response study showed that GNPs exposure increased malondialdehyde level and decreased CuZn-superoxide dismutase, catalase, and glutathione peroxidase activities in rat lungs. Furthermore, the histopathological study showed that combined effects of GNPs and SMFs led to more tissular damages in rat lungs in comparison with GNPs-treated rats. Interestingly, intensity of red fluorescence signal was enhanced after exposure to SMFs indicating a higher accumulation of GNPs in rat lungs under magnetic environment. Moreover, rats coexposed to GNPs and SMFs showed an increased malondialdehyde level, a fall of CuZn-superoxide dismutase, catalase, and glutathione peroxidase activities in comparison with GNPs-treated group. Hence, SMFs exposure increased the accumulation of GNPs in rat lungs and led to more toxic effects of these nanocomplexes. Keywords: malondialdehyde, catalase, superoxide dismutase, glutathione peroxidase, bronchus-associated lymphoid tissue, nanotoxicity, histopathological study

  16. Exposure to static magnetic fields and risk of accidents among a cohort of workers from a medical imaging device manufacturing facility.

    Science.gov (United States)

    Bongers, Suzan; Slottje, Pauline; Portengen, Lützen; Kromhout, Hans

    2016-05-01

    To study the association between occupational MRI-related static magnetic fields (SMF) exposure and the occurrence of accidents. Recent and career SMF exposure was assessed by linking a retrospective job exposure matrix to payroll based job histories, for a cohort of (former) workers of an imaging device manufacturing facility in the Netherlands. Occurrence of accidents was collected through an online questionnaire. Self-reported injuries due to accidents in the past 12 months, and the first (near) traffic accident while commuting to work and from work were analyzed with logistic regression and discrete-time survival analyses, respectively. High recent SMF exposure was associated with an increased risk of accidents leading to injuries [odds ratio (OR) 4.16]. For high recent and career SMF exposure, an increased risk was observed for accidents resulting in physician-treated injuries (OR 5.78 and 2.79, respectively) and an increased lifetime risk of (near) accidents during commute to work (hazard ratios 2.49 and 2.45, respectively), but not from work. We found an association between MRI-related occupational SMF exposure and an increased risk of accidents leading to injury, and for commute-related (near) accidents during the commute from home to work. Further research into health effects of (long-term) SMF exposure is warranted to corroborate our findings. © 2015 Wiley Periodicals, Inc.

  17. Effect of static magnetic field on pain level and expression of P2X3 receptors in the trigeminal ganglion in mice following experimental tooth movement.

    Science.gov (United States)

    Zhu, Yafen; Wang, Shengguo; Long, Hu; Zhu, Jingyi; Jian, Fan; Ye, Niansong; Lai, Wenli

    2017-01-01

    Recent research has demonstrated that static magnetic fields (SMF) can generate an analgesic effect in different conditions. The present study explored effects of SMF on pain levels and expressions of P2X3 receptors in trigeminal ganglion (TG) in mice after experimental tooth movement (tooth movement induced by springs between teeth). Experiments were performed in male mice (body mass: 25-30 g) and divided into SMF + force group, force group, and no force group. Exposure time was over 22 h per day. Mouse Grimace Scale was used for evaluating orofacial pain levels during experimental tooth movement at 4 h and 1, 3, 7, and 14 days. Meanwhile, expression levels of P2X3 receptors in the TG were evaluated by immunohistochemistry and western blotting at same time points. We finally found that during experimental tooth movement, pain levels of mice peaked at 3 days, and then decreased. While pain levels of mice were reduced in the SMF environment at 4 h, 1 and 3 days, there was a significant difference at 1 and 3 days. Meanwhile, under the action of SMF, expression levels of P2X3 receptors in TG were significantly lower at 4 h, 3 and 7 days. These results suggest that SMF can reduce pain levels in mice, and down-regulate P2X3 receptors in TG. Bioelectromagnetics. 38:22-30, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  18. Enhancement of load frequency stabilization effect of superconducting magnetic energy storage by static synchronous series compensator based on H ∞ control

    International Nuclear Information System (INIS)

    Ngamroo, Issarachai; Taeratanachai, Chanin; Dechanupaprittha, Sanchai; Mitani, Yasunori

    2007-01-01

    It is well known that the load frequency stabilization effect of superconducting magnetic energy storage (SMES) in an interconnected power system is restricted to its located area. The SMES almost has no frequency stabilization effect in another interconnected area. To enhance the frequency stabilization effect of SMES, the static synchronous series compensator (SSSC) can be applied as an auxiliary device. The SSSC can be used as an energy transfer device of the SMES to stabilize the frequency in another interconnected area. The proposed technique not only introduces a sophisticated frequency stabilization in deregulated power systems but also offers a smart energy management control of SMES. In addition, to take the robust stability of the controlled power system against system uncertainties into account, the H ∞ control is used to design robust frequency stabilizers of the SMES and SSSC. Simulation results in a two area interconnected power system confirm the high robustness of the frequency stabilizers SMES and SSSC against load disturbances and system uncertainties

  19. Modification of catalase and MAPK in Vicia faba cultivated in soil with high natural radioactivity and treated with a static magnetic field.

    Science.gov (United States)

    Haghighat, Nazanin; Abdolmaleki, Parviz; Ghanati, Faezeh; Behmanesh, Mehrdad; Payez, Atefeh

    2014-03-01

    The effects of a static magnetic field (SMF) and high natural radioactivity (HR) on catalase and MAPK genes in Vicia faba were investigated. Soil samples with high natural radioactivity were collected from Ramsar in north Iran where the annual radiation absorbed dose from background radiation is higher than 20mSv/year. The specific activity of the radionuclides of (232)Th, (236)Ra, and (40)K was measured using gamma spectrometry. The seeds were planted either in the soil with high natural radioactivity or in the control soils and were then exposed to a SMF of 30mT for 8 days; 8h/day. Levels of expression of catalase and MAPK genes, catalase activity and H2O2 content were evaluated. The results demonstrated significant differences in the expression of catalase and MAPK genes in SMF- and HR-treated plants compared to the controls. An increase in catalase activity was accompanied by increased expression of its gene and accumulation of H2O2. Relative expression of the MAPK gene in treated plants, however, was lower than those of the controls. The results suggest that the response of V. faba plants to SMF and HR may be mediated by modification of catalase and MAPK. Copyright © 2013 Elsevier GmbH. All rights reserved.

  20. Pre-sowing static magnetic field treatment for improving water and radiation use efficiency in chickpea (Cicer arietinum L.) under soil moisture stress.

    Science.gov (United States)

    Mridha, Nilimesh; Chattaraj, Sudipta; Chakraborty, Debashis; Anand, Anjali; Aggarwal, Pramila; Nagarajan, Shantha

    2016-09-01

    Soil moisture stress during pod filling is a major constraint in production of chickpea (Cicer arietinum L.), a fundamentally dry land crop. We investigated effect of pre-sowing seed priming with static magnetic field (SMF) on alleviation of stress through improvement in radiation and water use efficiencies. Experiments were conducted under greenhouse and open field conditions with desi and kabuli genotypes. Seeds exposed to SMF (strength: 100 mT, exposure: 1 h) led to increase in root volume and surface area by 70% and 65%, respectively. This enabled the crop to utilize 60% higher moisture during the active growth period (78-118 days after sowing), when soil moisture became limiting. Both genotypes from treated seeds had better water utilization, biomass, and radiation use efficiencies (17%, 40%, and 26% over control). Seed pre-treatment with SMF could, therefore, be a viable option for chickpea to alleviate soil moisture stress in arid and semi-arid regions, helping in augmenting its production. It could be a viable option to improve growth and yield of chickpea under deficit soil moisture condition, as the selection and breeding program takes a decade before a tolerant variety is released. Bioelectromagnetics. 37:400-408, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  1. Ion-optical studies for a range adaptation method in ion beam therapy using a static wedge degrader combined with magnetic beam deflection

    International Nuclear Information System (INIS)

    Chaudhri, Naved; Saito, Nami; Bert, Christoph; Franczak, Bernhard; Steidl, Peter; Durante, Marco; Schardt, Dieter; Rietzel, Eike

    2010-01-01

    Fast radiological range adaptation of the ion beam is essential when target motion is mitigated by beam tracking using scanned ion beams for dose delivery. Electromagnetically controlled deflection of a well-focused ion beam on a small static wedge degrader positioned between two dipole magnets, inside the beam delivery system, has been considered as a fast range adaptation method. The principle of the range adaptation method was tested in experiments and Monte Carlo simulations for the therapy beam line at the GSI Helmholtz Centre for Heavy Ions Research. Based on the simulations, ion optical settings of beam deflection and realignment of the adapted beam were experimentally applied to the beam line, and additional tuning was manually performed. Different degrader shapes were employed for the energy adaptation. Measured and simulated beam profiles, i.e. lateral distribution and range in water at isocentre, were analysed and compared with the therapy beam values for beam scanning. Deflected beam positions of up to ±28 mm on degrader were performed which resulted in a range adaptation of up to ±15 mm water equivalence (WE). The maximum deviation between the measured adapted range from the nominal range adaptation was below 0.4 mm WE. In experiments, the width of the adapted beam at the isocentre was adjustable between 5 and 11 mm full width at half maximum. The results demonstrate the feasibility/proof of the proposed range adaptation method for beam tracking from the beam quality point of view.

  2. Analysis of technology and seminar on economic trends about High-intensity LED

    International Nuclear Information System (INIS)

    2003-09-01

    This is divided into two parts. Contents of this report in the first part are technical trends on high-intensity LED which reports introduction of LED as compound semiconductor, white LED? patent issues, review on technology of High-intensity LED and Reliability of High-intensity LED. The second part deals with economic tends about High-intensity LED. This seminar was held to report analysis and economical trends about High-intensity LED by Korea Industrial Education Institute in 2003.

  3. High intensity accelerator for a wide range of applications

    International Nuclear Information System (INIS)

    Conard, E.M.

    1994-01-01

    When looking at commercial applications of accelerators from a market point of view, it appears that a common accelerator design could meet different users' needs. This would benefit both the manufacturer and the user by multiplying the number of machines sold, thus lowering their cost and improving their quality. These applications include: radioisotope production for medical imaging (positron emission tomography), industrial imaging and non-destructive testing (e.g. neutron radiography, explosive and drug detection in luggage or freight). This paper investigates the needs of the various applications and defines their common denominator to establish suitable specifications (type of particles, energy, intensity). Different accelerator types (cyclotrons, linear accelerators and electrostatic machines) are reviewed and compared on performance and estimated costs. A high intensity tandem accelerator design is studied in more detail as it seems the most appropriate candidate. ((orig.))

  4. High-Intensity Intermittent Exercise and Fat Loss

    Directory of Open Access Journals (Sweden)

    Stephen H. Boutcher

    2011-01-01

    Full Text Available The effect of regular aerobic exercise on body fat is negligible; however, other forms of exercise may have a greater impact on body composition. For example, emerging research examining high-intensity intermittent exercise (HIIE indicates that it may be more effective at reducing subcutaneous and abdominal body fat than other types of exercise. The mechanisms underlying the fat reduction induced by HIIE, however, are undetermined. Regular HIIE has been shown to significantly increase both aerobic and anaerobic fitness. HIIE also significantly lowers insulin resistance and results in a number of skeletal muscle adaptations that result in enhanced skeletal muscle fat oxidation and improved glucose tolerance. This review summarizes the results of HIIE studies on fat loss, fitness, insulin resistance, and skeletal muscle. Possible mechanisms underlying HIIE-induced fat loss and implications for the use of HIIE in the treatment and prevention of obesity are also discussed.

  5. An outline of research facilities of high intensity proton accelerator

    International Nuclear Information System (INIS)

    Tanaka, Shun-ichi

    1995-01-01

    A plan called PROTON ENGINEERING CENTER has been proposed in JAERI. The center is a complex composed of research facilities and a beam shape and storage ring based on a proton linac with an energy of 1.5 GeV and an average current of 10 mA. The research facilities planned are OMEGA·Nuclear Energy Development Facility, Neutron Facility for Material Irradiation, Nuclear Data Experiment Facility, Neutron Factory, Meson Factory, spallation Radioisotope Beam Facility, and Medium Energy Experiment Facility, where high intensity proton beam and secondary particle beams such as neutrons, π-mesons, muons, and unstable isotopes originated from the protons are available for promoting the innovative research of nuclear energy and basic science and technology. (author)

  6. High intensity proton accelerator and its application (Proton Engineering Center)

    International Nuclear Information System (INIS)

    Tanaka, Shun-ichi

    1995-01-01

    A plan called PROTON ENGINEERING CENTER has been proposed in JAERI. The center is a complex composed of research facilities and a beam shape and storage ring based on a proton linac with an energy of 1.5 GeV and an average current of 10 mA. The research facilities planned are OMEGA·Nuclear Energy Development Facility, Neutron Facility for Material Irradiation, Nuclear Data Experiment Facility, Neutron Factory, Meson Factory, Spallation Radioisotope Beam Facility, and Medium Energy Experiment Facility, where high intensity proton beam and secondary particle beams such as neutrons, π-mesons, muons, and unstable isotopes originated from the protons are available for promoting the innovative research of nuclear energy and basic science and technology. (author)

  7. Simplified shielding calculation system for high-intensity proton accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Masumura, Tomomi; Nakashima, Hiroshi; Nakane, Yoshihiro; Sasamoto, Nobuo [Center for Neutron Science, Tokai Research Establishment, Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan)

    2000-06-01

    A simplified shielding calculation system is developed for applying conceptual shielding design of facilities in the joint project for high-intensity proton accelerators. The system is composed of neutron transmission calculation part for bulk shielding using simplified formulas: Moyer model and Tesch's formula, and neutron skyshine calculation part using an empirical formula: Stapleton's formula. The system is made with the Microsoft Excel software for user's convenience. This report provides a manual for the system as well as calculation conditions used in the calculation such as Moyer model's parameters. In this report preliminary results based on data at December 8, 1999, are also shown as an example. (author)

  8. Overview of High Intensity Linac Programs in Europe

    CERN Document Server

    Garoby, R

    2004-01-01

    Recent years have seen a boost in the support by the European Union (EU) of accelerator research in Europe. Provided they coordinate their efforts and define common goals and strategies, laboratories and institutions from the member states can receive a financial support reaching 50% of the total project cost. In the field of High Intensity Linacs, the EU has already supported the EURISOL initiative for nuclear physics, which this year is applying for funding of a Design Study, and the development of linacs for Waste Transmutation. More recently, an initiative for high-energy physics has been approved, which includes a programme for the development of pulsed linac technologies. The coordination and synergy imposed by the EU rules increase the benefit of the allocated resources. Combined with the ongoing internal projects in the partner laboratories, these European initiatives represent a strong effort focussed towards the development of linac technologies. This paper summarises the requests from the various E...

  9. Pedalling rate affects endurance performance during high-intensity cycling

    DEFF Research Database (Denmark)

    Nielsen, Jens Steen; Hansen, Ernst Albin; Sjøgaard, Gisela

    2004-01-01

    The purpose of this study into high-intensity cycling was to: (1) test the hypothesis that endurance time is longest at a freely chosen pedalling rate (FCPR), compared to pedalling rates 25% lower (FCPR-25) and higher (FCPR+25) than FCPR, and (2) investigate how physiological variables......, and endurance time at W90 with FCPR-25, FCPR, and FCPR+25. Power reserve was calculated as the difference between applied power output at a given pedalling rate and peak crank power at this same pedalling rate. W90 was 325 (47) W. FCPR at W90 was 78 (11) rpm, resulting in FCPR-25 being 59 (8) rpm and FCPR+25...... time was negatively related to VO(2max), W90 and % MHC I, while positively related to power reserve. In conclusion, at group level, endurance time was longer at FCPR and at a pedalling rate 25% lower compared to a pedalling rate 25% higher than FCPR. Further, inter-individual physiological variables...

  10. High Intensity Interval Training for Maximizing Health Outcomes.

    Science.gov (United States)

    Karlsen, Trine; Aamot, Inger-Lise; Haykowsky, Mark; Rognmo, Øivind

    Regular physical activity and exercise training are important actions to improve cardiorespiratory fitness and maintain health throughout life. There is solid evidence that exercise is an effective preventative strategy against at least 25 medical conditions, including cardiovascular disease, stroke, hypertension, colon and breast cancer, and type 2 diabetes. Traditionally, endurance exercise training (ET) to improve health related outcomes has consisted of low- to moderate ET intensity. However, a growing body of evidence suggests that higher exercise intensities may be superior to moderate intensity for maximizing health outcomes. The primary objective of this review is to discuss how aerobic high-intensity interval training (HIIT) as compared to moderate continuous training may maximize outcomes, and to provide practical advices for successful clinical and home-based HIIT. Copyright © 2017. Published by Elsevier Inc.

  11. High Intensity Beam Issues in the CERN Proton Synchrotron

    CERN Document Server

    Aumon, Sandra; Rivkin, Leonid

    This PhD work is about limitations of high intensity proton beams observed in the CERN Proton Synchrotron (PS) and, in particular, about issues at injection and transition energies. With its 53 years, the CERN PS would have to operate beyond the limit of its performance to match the future requirements. Beam instabilities driven by transverse impedance and aperture restrictions are important issues for the operation and for the High-Luminosity LHC upgrade which foresees an intensity increase delivered by the injectors. The main subject of the thesis concerns the study of a fast transverse instability occurring at transition energy. The proton beams crossing this energy range are particularly sensitive to wake forces because of the slow synchrotron motion. This instability can cause a strong vertical emittance blow-up and severe losses in less than a synchrotron period. Experimental observations show that the particles at the peak density of the beam longitudinal distribution oscillate in the vertical plane du...

  12. Relativistic electron mirrors from high intensity laser nanofoil interactions

    International Nuclear Information System (INIS)

    Kiefer, Daniel

    2012-01-01

    The reflection of a laser pulse from a mirror moving close to the speed of light could in principle create an X-ray pulse with unprecedented high brightness owing to the increase in photon energy and accompanying temporal compression by a factor of 4γ 2 , where γ is the Lorentz factor of the mirror. While this scheme is theoretically intriguingly simple and was first discussed by A. Einstein more than a century ago, the generation of a relativistic structure which acts as a mirror is demanding in many different aspects. Recently, the interaction of a high intensity laser pulse with a nanometer thin foil has raised great interest as it promises the creation of a dense, attosecond short, relativistic electron bunch capable of forming a mirror structure that scatters counter-propagating light coherently and shifts its frequency to higher photon energies. However, so far, this novel concept has been discussed only in theoretical studies using highly idealized interaction parameters. This thesis investigates the generation of a relativistic electron mirror from a nanometer foil with current state-of-the-art high intensity laser pulses and demonstrates for the first time the reflection from those structures in an experiment. To achieve this result, the electron acceleration from high intensity laser nanometer foil interactions was studied in a series of experiments using three inherently different high power laser systems and free-standing foils as thin as 3nm. A drastic increase in the electron energies was observed when reducing the target thickness from the micrometer to the nanometer scale. Quasi-monoenergetic electron beams were measured for the first time from ultrathin (≤5nm) foils, reaching energies up to ∝35MeV. The acceleration process was studied in simulations well-adapted to the experiments, indicating the transition from plasma to free electron dynamics as the target thickness is reduced to the few nanometer range. The experience gained from those

  13. High-Intensity Focused Ultrasound Treatment for Advanced Pancreatic Cancer

    Directory of Open Access Journals (Sweden)

    Yufeng Zhou

    2014-01-01

    Full Text Available Pancreatic cancer is under high mortality but has few effective treatment modalities. High-intensity focused ultrasound (HIFU is becoming an emerging approach of noninvasively ablating solid tumor in clinics. A variety of solid tumors have been tried on thousands of patients in the last fifteen years with great success. The principle, mechanism, and clinical outcome of HIFU were introduced first. All 3022 clinical cases of HIFU treatment for the advanced pancreatic cancer alone or in combination with chemotherapy or radiotherapy in 241 published papers were reviewed and summarized for its efficacy, pain relief, clinical benefit rate, survival, Karnofsky performance scale (KPS score, changes in tumor size, occurrence of echogenicity, serum level, diagnostic assessment of outcome, and associated complications. Immune response induced by HIFU ablation may become an effective way of cancer treatment. Comments for a better outcome and current challenges of HIFU technology are also covered.

  14. Fast damping in mismatched high intensity beam transportation

    Directory of Open Access Journals (Sweden)

    V. Variale

    2001-08-01

    Full Text Available A very fast damping of beam envelope oscillation amplitudes was recently observed in simulations of high intensity beam transport, through periodic FODO cells, in mismatched conditions [V. Variale, Nuovo Cimento Soc. Ital. Fis. 112A, 1571–1582 (1999 and T. Clauser et al., in Proceedings of the Particle Accelerator Conference, New York, 1999 (IEEE, Piscataway, NJ, 1999, p. 1779]. A Landau damping mechanism was proposed at the origin of observed effect. In this paper, to further investigate the source of this fast damping, extensive simulations have been carried out. The results presented here support the interpretation of the mechanism at the origin of the fast damping as a Landau damping effect.

  15. Relativistic electron mirrors from high intensity laser nanofoil interactions

    Energy Technology Data Exchange (ETDEWEB)

    Kiefer, Daniel

    2012-12-21

    The reflection of a laser pulse from a mirror moving close to the speed of light could in principle create an X-ray pulse with unprecedented high brightness owing to the increase in photon energy and accompanying temporal compression by a factor of 4γ{sup 2}, where γ is the Lorentz factor of the mirror. While this scheme is theoretically intriguingly simple and was first discussed by A. Einstein more than a century ago, the generation of a relativistic structure which acts as a mirror is demanding in many different aspects. Recently, the interaction of a high intensity laser pulse with a nanometer thin foil has raised great interest as it promises the creation of a dense, attosecond short, relativistic electron bunch capable of forming a mirror structure that scatters counter-propagating light coherently and shifts its frequency to higher photon energies. However, so far, this novel concept has been discussed only in theoretical studies using highly idealized interaction parameters. This thesis investigates the generation of a relativistic electron mirror from a nanometer foil with current state-of-the-art high intensity laser pulses and demonstrates for the first time the reflection from those structures in an experiment. To achieve this result, the electron acceleration from high intensity laser nanometer foil interactions was studied in a series of experiments using three inherently different high power laser systems and free-standing foils as thin as 3nm. A drastic increase in the electron energies was observed when reducing the target thickness from the micrometer to the nanometer scale. Quasi-monoenergetic electron beams were measured for the first time from ultrathin (≤5nm) foils, reaching energies up to ∝35MeV. The acceleration process was studied in simulations well-adapted to the experiments, indicating the transition from plasma to free electron dynamics as the target thickness is reduced to the few nanometer range. The experience gained from those

  16. High-intensity, subkilovolt x-ray calibration facility

    International Nuclear Information System (INIS)

    Kuckuck, R.W.; Gaines, J.L.; Ernst, R.D.

    1976-01-01

    A high-intensity subkilovolt x-ray calibration source utilizing proton-induced inner-shell atomic fluorescence of low-Z elements is described. The high photon yields and low bremsstrahlung background associated with this phenomenon are ideally suited to provide intense, nearly monoenergetic x-ray beams. The proton accelerator is a 3 mA, 300 kV Cockroft-Walton using a conventional rf hydrogen ion source. Seven remotely-selectable targets capable of heat dissipation of 5 kW/cm 2 are used to provide characteristic x-rays with energies between 100 and 1000 eV. Source strengths are of the order of 10 13 to 10 14 photons/sec. Methods of reducing spectral contamination due to hydrocarbon build-up on the target are discussed. Typical x-ray spectra (Cu-L, C-K and B-K) are shown

  17. 'J-KAREN' - high intensity, high contrast laser

    International Nuclear Information System (INIS)

    Kiriyama, Hiromitsu; Mori, Michiaki; Nakai, Yoshiki; Okada, Hajime; Sasao, Hajime; Sagisaka, Akito; Ochi, Yoshihiro; Tanaka, Momoko; Kondo, Kiminori; Tateno, Ryo; Sugiyama, Akira; Daido, Hiroyuki; Koike, Masato; Kawanishi, Syunichi; Shimomura, Takuya; Tanoue, Manabu; Wakai, Daisuke; Kondo, Shuji; Kanazawa, Shuhei

    2010-01-01

    We report on the high intensity, high contrast double chirped-pulse amplification (CPA) Ti:sapphire laser system (named J-KAREN). By use of an optical parametric chirped-pulse amplification (OPCPA) preamplifier that is seeded by a cleaned high-energy pulse, a background amplified spontaneous emission (ASE) level of 10 -10 relative to the peak main femtosecond pulse on the picosecond timescales demonstrated with an output energy of 1.7 J and a pulse duration of 30 fs, corresponding to a peak power of 60TW at a 10 Hz repetition rate. This system which uses a cryogenically-cooled Ti:sapphire final amplifier generates focused peak intensity in excess of 10 20 W/cm 2 at a 10 Hz repetition rate. (author)

  18. What IAPT CBT High-Intensity Trainees Do After Training.

    Science.gov (United States)

    Liness, Sheena; Lea, Susan; Nestler, Steffen; Parker, Hannah; Clark, David M

    2017-01-01

    The UK Department of Health Improving Access to Psychological Therapies (IAPT) initiative set out to train a large number of therapists in cognitive behaviour therapies (CBT) for depression and anxiety disorders. Little is currently known about the retention of IAPT CBT trainees, or the use of CBT skills acquired on the course in the workplace after training has finished. This study set out to conduct a follow-up survey of past CBT trainees on the IAPT High Intensity CBT Course at the Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London (KCL), one of the largest IAPT High Intensity courses in the UK. Past trainees (n = 212) across 6 cohorts (2008-2014 intakes) were contacted and invited to participate in a follow-up survey. A response rate of 92.5% (n = 196) was achieved. The vast majority of IAPT trainees continue to work in IAPT services posttraining (79%) and to practise CBT as their main therapy modality (94%); 61% have become CBT supervisors. A minority (23%) have progressed to other senior roles in the services. Shortcomings are reported in the use of out-of-office CBT interventions, the use of disorder-specific outcome measures and therapy recordings to inform therapy and supervision. Past trainees stay working in IAPT services and continue to use CBT methods taught on the course. Some NICE recommended treatment procedures that are likely to facilitate patients' recovery are not being routinely implemented across IAPT services. The results have implications for the continued roll out of the IAPT programme, and other future large scale training initiatives.

  19. The Effect of High Intensity Intermittent Exercise on Power Output for the Upper Body

    Directory of Open Access Journals (Sweden)

    Leonie Harvey

    2015-06-01

    Full Text Available The aim of the present study was to examine and measure high intensity, intermittent upper body performance, in addition to identifying areas of the body that affect the variance in total work done during the 5 × 6 s sprint test. Fifteen males completed an upper body 5 × 6 s sprint test on a modified electro-magnetically braked cycle ergometer, which consisted of five maximal effort sprints, each 6 s in duration, separated by 24 s of passive recovery. A fly wheel braking force corresponding to 5% of the participants’ body weight was used as the implemented resistance level. Body composition was measured using dual-energy X-ray absorptiometry (DEXA. Percent (% decrement was calculated as 100 − (Total work/ideal work × 100. Significant (P < 0.05 differences were found between sprints for both absolute and relative (W, W·kg−1, W·kg−1 Lean body mass (LBM and W·kg−1 Upper body lean body mass (UBLBM peak (PP and mean (MP power. The % decrement in total work done over the five sprints was 11.4%. Stepwise multiple linear regression analysis revealed that UBLBM accounts for 87% of the variance in total work done during the upper body 5 × 6 s sprint test. These results provide a descriptive analysis of upper body, high intensity intermittent exercise, demonstrating that PP and MP output decreased significantly during the upper body 5 × 6 s sprint test.

  20. A high-intensity plasma-sputter heavy negative ion source

    International Nuclear Information System (INIS)

    Alton, G.D.; Mori, Y.; Takagi, A.; Ueno, A.; Fukumoto, S.

    1989-01-01

    A multicusp magnetic field plasma surface ion source, normally used for H/sup /minus//ion beam formation, has been modified for the generation of high-intensity, pulsed, heavy negative ion beams suitable for a variety of uses. To date, the source has been utilized to produce mA intensity pulsed beams of more than 24 species. A brief description of the source, and basic pulsed-mode operational data, (e.g., intensity versus cesium oven temperature, sputter probe voltage, and discharge pressure), are given. In addition, illustrative examples of intensity versus time and the mass distributions of ion beams extracted from a number of samples along with emittance data, are also presented. Preliminary results obtained during dc operation of the source under low discharge power conditions suggest that sources of this type may also be used to produce high-intensity (mA) dc beams. The results of these investigations are given, as well, and the technical issues that must be addressed for this mode of operation are discussed. 15 refs., 10 figs., 2 tabs

  1. Effects of menopause and high-intensity training on insulin sensitivity and muscle metabolism.

    Science.gov (United States)

    Mandrup, Camilla M; Egelund, Jon; Nyberg, Michael; Enevoldsen, Lotte Hahn; Kjær, Andreas; Clemmensen, Andreas E; Christensen, Anders Nymark; Suetta, Charlotte; Frikke-Schmidt, Ruth; Steenberg, Dorte Enggaard; Wojtaszewski, Jørgen F P; Hellsten, Ylva; Stallknecht, Bente M

    2018-02-01

    To investigate peripheral insulin sensitivity and skeletal muscle glucose metabolism in premenopausal and postmenopausal women, and evaluate whether exercise training benefits are maintained after menopause. Sedentary, healthy, normal-weight, late premenopausal (n = 21), and early postmenopausal (n = 20) women were included in a 3-month high-intensity exercise training intervention. Body composition was assessed by magnetic resonance imaging and dual-energy x-ray absorptiometry, whole body glucose disposal rate (GDR) by hyperinsulinemic euglycemic clamp (40 mU/m/min), and femoral muscle glucose uptake by positron emission tomography/computed tomography, using the glucose analog fluorodeoxyglucose, expressed as estimated metabolic rate (eMR). Insulin signaling was investigated in muscle biopsies. Age difference between groups was 4.5 years, and no difference was observed in body composition. Training increased lean body mass (estimate [95% confidence interval] 0.5 [0.2-0.9] kg, P training (eMR vastus lateralis muscle: 27.8 [19.6-36.0] μmol/min/kg, P training-induced increases in insulin sensitivity included increased expression of hexokinase (19.2 [5.0-24.7] AU, P = 0.02) and glycogen synthase (32.4 [15.0-49.8] AU, P high-intensity exercise training.

  2. Changes in the expression and current of the Na+/K+ pump in the snail nervous system after exposure to a static magnetic field.

    Science.gov (United States)

    Nikolić, Ljiljana; Bataveljić, Danijela; Andjus, Pavle R; Nedeljković, Miodrag; Todorović, Dajana; Janać, Branka

    2013-09-15

    Compelling evidence supports the use of a moderate static magnetic field (SMF) for therapeutic purposes. In order to provide insight into the mechanisms underlying SMF treatment, it is essential to examine the cellular responses elicited by therapeutically applied SMF, especially in the nervous system. The Na(+)/K(+) pump, by creating and maintaining the gradient of Na(+) and K(+) ions across the plasma membrane, regulates the physiological properties of neurons. In this study, we examined the expression of the Na(+)/K(+) pump in the isolated brain-subesophageal ganglion complex of the garden snail Helix pomatia, along with the immunoreactivity and current of the Na(+)/K(+) pump in isolated snail neurons after 15 min exposure to a moderate (10 mT) SMF. Western blot and immunofluorescence analysis revealed that 10 mT SMF did not significantly change the expression of the Na(+)/K(+) pump α-subunit in the snail brain and the neuronal cell body. However, our immunofluorescence data showed that SMF treatment induced a significant increase in the Na(+)/K(+) pump α-subunit expression in the neuronal plasma membrane area. This change in Na(+)/K(+) pump expression was reflected in pump activity as demonstrated by the pump current measurements. Whole-cell patch-clamp recordings from isolated snail neurons revealed that Na(+)/K(+) pump current density was significantly increased after the 10 mT SMF treatment. The SMF-induced increase was different in the two groups of control snail neurons, as defined by the pump current level. The results obtained could represent a physiologically important response of neurons to 10 mT SMF comparable in strength to therapeutic applications.

  3. High intensity laser interactions with sub-micron droplets

    International Nuclear Information System (INIS)

    Mountford, L.C.

    1999-01-01

    A high-density source of liquid ethanol droplets has been developed, characterised and used in laser interaction studies for the first time. Mie Scattering and attenuation measurements show that droplets with a radius of (0.5 ± 0.1) μm and atomic densities of 10 19 atoms/cm 3 can be produced, bridging the gap between clusters and macroscopic solids. Lower density (10 16 cm -3 ) sprays can also be produced and these are electrostatically split into smaller droplets with a radius of (0.3 ± 0.1) μm. This work has been accepted for publication in Review of Scientific Instruments. A range of high intensity interaction experiments have been carried out with this unique sub-micron source. The absolute yield of keV x-rays, generated using 527 nm, 2 ps pulses focused to ∼10 17 W/cm 2 , was measured for the first time. ∼7 μJ of x-rays with photon energies above 1 keV were produced, comparable to yields obtained from much higher Z Xenon clusters. At intensities ≤10 16 W/cm 2 the yield from droplets exceeds that from solid targets of similar Z. The droplet medium is debris free and self-renewing, providing a suitable x-ray source for lithographic techniques. Due to the spacing between the droplets, it was expected that the droplet plasma temperature would exceed that of a solid target plasma, which is typically limited by rapid heat conduction to <1 keV. Analysis of the x-ray data shows this to be true with a mean droplet plasma temperature of (2 ± 0.8) keV, and a number of measurements exceeding 5 keV (to appear in Applied Physics Letters). The absorption of high intensity laser pulses in the dense spray has been measured for the first time and this was found to be wavelength and polarisation independent and in excess of 60%. These first interaction measurements clearly indicate that there are significant differences between the laser heating of droplet, solid and cluster targets. (author)

  4. Longitudinal tracking studies for a high intensity proton synchrotron

    International Nuclear Information System (INIS)

    Lessner, E.; Cho, Y.; Harkay, K.; Symon, K.

    1995-01-01

    Results from longitudinal tracking studies for a high intensity proton synchrotron designed for a 1-MW spallation source are presented. The machine delivers a proton beam of 0.5 mA time-averaged current at a repetition rate of 30 Hz. The accelerator is designed to have radiation levels that allow hands-on-maintenance. However, the high beam intensity causes strong space charge fields whose effects may lead to particle loss and longitudinal instabilities. The space charge fields modify the particle distribution, distort the stable bucket area and reduce the rf linear restoring force. Tracking simulations were conducted to analyze the space charge effects on the dynamics of the injection and acceleration processes and means to circumvent them. The tracking studies led to the establishment of the injected beam parameters and rf voltage program that minimized beam loss and longitudinal instabilities. Similar studies for a 10-GeV synchrotron that uses the 2-GeV synchrotron as its injector are also discussed

  5. Inelastic scattering in condensed matter with high intensity Moessbauer radiation

    International Nuclear Information System (INIS)

    Yelon, W.B.; Schupp, G.

    1993-02-01

    The QUEGS facility at MURR has produced a number of new results and demonstrated the range of potential applications of high resolution, high intensity Moessbauer scattering. This work has been carried out by both MU and Purdue researchers and includes published results on Na, W, pentadecane, polydimethylsiloxane and other systems, manuscripts submitted on alkali halides (Phys. Rev. B) and accurate Moessbauer lineshape measurements (Phys. Rev. C), and manuscripts in preparation on glycerol, NiAl and Moessbauer spectra obtained by modulating a scattering crystal. Recently, new collaborations have been initiated which will substantially enhance our efforts. These are with W. Steiner (Vienna), G. Coddens (Saclay), and R. D. Taylor (Los Alamos). Steiner is experienced with Fe-57 Moessbauer scattering, while Coddens specializes in quasielastic neutron scattering; both of these areas naturally complement our work. R. D. Taylor has pioneered Moessbauer spectroscopy from the time of its discovery and has already made important contributions to our study of lattice dynamics and superconductivity for lead alloyed with small quantities of tin. At the same time, a significant instrument upgrade is underway, funded in part by the DOE-URIP program

  6. The WARP Code: Modeling High Intensity Ion Beams

    International Nuclear Information System (INIS)

    Grote, David P.; Friedman, Alex; Vay, Jean-Luc; Haber, Irving

    2005-01-01

    The Warp code, developed for heavy-ion driven inertial fusion energy studies, is used to model high intensity ion (and electron) beams. Significant capability has been incorporated in Warp, allowing nearly all sections of an accelerator to be modeled, beginning with the source. Warp has as its core an explicit, three-dimensional, particle-in-cell model. Alongside this is a rich set of tools for describing the applied fields of the accelerator lattice, and embedded conducting surfaces (which are captured at sub-grid resolution). Also incorporated are models with reduced dimensionality: an axisymmetric model and a transverse ''slice'' model. The code takes advantage of modern programming techniques, including object orientation, parallelism, and scripting (via Python). It is at the forefront in the use of the computational technique of adaptive mesh refinement, which has been particularly successful in the area of diode and injector modeling, both steady-state and time-dependent. In the presentation, some of the major aspects of Warp will be overviewed, especially those that could be useful in modeling ECR sources. Warp has been benchmarked against both theory and experiment. Recent results will be presented showing good agreement of Warp with experimental results from the STS500 injector test stand

  7. Shielding for high energy, high intensity electron accelerator installation

    International Nuclear Information System (INIS)

    Warawas, C.; Chongkum, S.

    1997-03-01

    The utilization of electron accelerators (eBA) is gradually increased in Thailand. For instance, a 30-40 MeV eBA are used for tumor and cancer therapy in the hospitals, and a high current eBA in for gemstone colonization. In the near future, an application of eBA in industries will be grown up in a few directions, e.g., flue gases treatment from the coal fire-power plants, plastic processing, rubber vulcanization and food preservation. It is the major roles of Office of Atomic Energy for Peace (OAEP) to promote the peaceful uses of nuclear energy and to regulate the public safety and protection of the environment. By taking into account of radiation safety aspect, high energy electrons are not only harmful to human bodies, but the radioactive nuclides can be occurred. This report presents a literature review by following the National Committee on Radiation Protection and Measurements (NCRP) report No.31. This reviews for parametric calculation and shielding design of the high energy (up to 100 MeV), high intensity electron accelerator installation

  8. High-intensity interval training improves obstructive sleep apnoea.

    Science.gov (United States)

    Karlsen, Trine; Nes, Bjarne Martens; Tjønna, Arnt Erik; Engstrøm, Morten; Støylen, Asbjørn; Steinshamn, Sigurd

    2016-01-01

    Three hours per week of vigorous physical activity is found to be associated with reduced odds of sleep-disordered breathing. To investigate whether 12 weeks of high-intensity interval training (HIIT) reduced the apnoea-hypopnea index (AHI) in obese subjects with moderate-to-severe obstructive sleep apnoea. In a prospective randomised controlled exercise study, 30 (body mass index 37±6 kg/m 2 , age 51±9 years) patients with sleep apnoea (AHI 41.5±25.3 events/hour) were randomised 1:1 to control or 12 weeks of supervised HIIT (4×4 min of treadmill running or walking at 90%-95% of maximal heart rate two times per week). In the HIIT group, the AHI was reduced by 7.5±11.6 events/hour (within-group pHIIT improved the AHI and self-reported daytime sleepiness in subjects with obese sleep apnoea without any change in the desaturation index and body weight.

  9. Multifunctional pulse generator for high-intensity focused ultrasound system

    Science.gov (United States)

    Tamano, Satoshi; Yoshizawa, Shin; Umemura, Shin-Ichiro

    2017-07-01

    High-intensity focused ultrasound (HIFU) can achieve high spatial resolution for the treatment of diseases. A major technical challenge in implementing a HIFU therapeutic system is to generate high-voltage high-current signals for effectively exciting a multichannel HIFU transducer at high efficiencies. In this paper, we present the development of a multifunctional multichannel generator/driver. The generator can produce a long burst as well as an extremely high-voltage short pulse of pseudosinusoidal waves (trigger HIFU) and second-harmonic superimposed waves for HIFU transmission. The transmission timing, waveform, and frequency can be controlled using a field-programmable gate array (FPGA) via a universal serial bus (USB) microcontroller. The hardware is implemented in a compact printed circuit board. The test results of trigger HIFU reveal that the power consumption and the temperature rise of metal-oxide semiconductor field-effect transistors were reduced by 19.9% and 38.2 °C, respectively, from the previous design. The highly flexible performance of the novel generator/driver is demonstrated in the generation of second-harmonic superimposed waves, which is useful for cavitation-enhanced HIFU treatment, although the previous design exhibited difficulty in generating it.

  10. High intensity proton linear accelerator for Neutron Science Project

    International Nuclear Information System (INIS)

    Mizumoto, Motoharu

    1999-01-01

    JAERI has been proposing the Neutron Science Project (NSP) which will be composed of a high intensity proton accelerator and various research facilities. With an energy of 1.5 GeV and a beam power of 8 MW, the accelerator is required for basic research fields and nuclear waste transmutation studies. The R and D work has been carried out for the components of the accelerator. In the low energy accelerator part, a beam test with an ion source and an RFQ has been performed with a current of 80 mA and a duty factor of 10% at an energy of 2 MeV. A 1 m long high power test model of DTL has been fabricated and tested with a duty factor of 20%. In the high energy accelerator part, a superconducting (SC) linac has been selected as a main option from 100 MeV to 1.5 GeV. A test stand for SC linac cavity with equipment of cryogenics, vacuum, RF source and cavity processing and cleaning system has been prepared to test the fabrication process and physics issues. The vertical tests of β = 0.5 (145 MeV) and β = 0.89 (1.1 GeV) single cell SC cavities have been made resulting in a maximum electric field strength of 44 MV/m and 47 MV/m at 2 K, respectively. (author)

  11. The WARP Code: Modeling High Intensity Ion Beams

    International Nuclear Information System (INIS)

    Grote, D P; Friedman, A; Vay, J L; Haber, I

    2004-01-01

    The Warp code, developed for heavy-ion driven inertial fusion energy studies, is used to model high intensity ion (and electron) beams. Significant capability has been incorporated in Warp, allowing nearly all sections of an accelerator to be modeled, beginning with the source. Warp has as its core an explicit, three-dimensional, particle-in-cell model. Alongside this is a rich set of tools for describing the applied fields of the accelerator lattice, and embedded conducting surfaces (which are captured at sub-grid resolution). Also incorporated are models with reduced dimensionality: an axisymmetric model and a transverse ''slice'' model. The code takes advantage of modern programming techniques, including object orientation, parallelism, and scripting (via Python). It is at the forefront in the use of the computational technique of adaptive mesh refinement, which has been particularly successful in the area of diode and injector modeling, both steady-state and time-dependent. In the presentation, some of the major aspects of Warp will be overviewed, especially those that could be useful in modeling ECR sources. Warp has been benchmarked against both theory and experiment. Recent results will be presented showing good agreement of Warp with experimental results from the STS500 injector test stand. Additional information can be found on the web page http://hif.lbl.gov/theory/WARP( ) summary.html

  12. High Intensity Effects in the SNS Accumulator Ring

    International Nuclear Information System (INIS)

    Holmes, Jeffrey A.; Cousineau, Sarah M.; Danilov, Viatcheslav; Plum, Michael A.; Shishlo, Andrei P.

    2008-01-01

    Currently operating at 0.5 MW beam power on target, the Spallation Neutron Source (SNS) is already the world's most powerful pulsed neutron source. However, we are only one third of the way to full power. As we ramp toward full power, the control of the beam and beam loss in the ring will be critical. In addition to practical considerations, such as choice of operating point, painting scheme, RF bunching, and beam scattering, it may be necessary to understand and mitigate collective effects due to space charge, impedances, and electron clouds. At each stage of the power ramp-up, we use all available resources to understand and to minimize beam losses. From the standpoint of beam dynamics, the losses observed so far under normal operating conditions have not involved collective phenomena. We are now entering the intensity regime in which this may change. In dedicated high intensity beam studies, we have already observed resistive wall, extraction kicker impedance-driven, and electron cloud activities. The analysis and simulation of this data are important ongoing activities at SNS. This paper discusses the status of this work, as well as other considerations necessary to the successful full power operation of SNS.

  13. A modified space charge routine for high intensity bunched beams

    International Nuclear Information System (INIS)

    Lapostolle, P.; Garnett, R.W.; Wangler, T.P.

    1996-01-01

    In 1991 a space charge calculation for bunched beam with a three-dimensional ellipsoid was proposed, replacing the usual SCHEFF routines. It removes the cylindrical symmetry required in SCHEFF and avoids the point to point interaction computation, whose number of simulation points is limited. This routine has now been improved with the introduction of two or three ellipsoids giving a good representation of the complex non-symmetrical form of the bunch (unlike the 3-d ellipsoidal assumption). The ellipsoidal density distributions are computed with a new method, avoiding the difficulty encountered near the centre (the axis in 2-d problems) by the previous method. It also provides a check of the ellipsoidal symmetry for each part of the distribution. Finally, the Fourier analysis reported in 1991 has been replaced by a very convenient Hermite expansion, which gives a simple but accurate representation of practical distributions. Comparisons with other space charge routines have been made, particularly with the ones applying other techniques such as SCHEFF. Introduced in the versatile beam dynamics code DYNAC, it should provide a good tool for the study of the various parameters responsible for the halo formation in high intensity linacs. (orig.)

  14. A review of adolescent high-intensity interval training.

    Science.gov (United States)

    Logan, Greig R M; Harris, Nigel; Duncan, Scott; Schofield, Grant

    2014-08-01

    Despite the promising evidence supporting positive effects of high-intensity interval training (HIIT) on the metabolic profile in adults, there is limited research targeting adolescents. Given the rising burden of chronic disease, it is essential to implement strategies to improve the cardiometabolic health in adolescence, as this is a key stage in the development of healthy lifestyle behaviours. This narrative review summarises evidence of the relative efficacy of HIIT regarding the metabolic health of adolescents. Methodological inconsistencies confound our ability to draw conclusions; however, there is meaningful evidence supporting HIIT as a potentially efficacious exercise modality for use in the adolescent cohort. Future research must examine the effects of various HIIT protocols to determine the optimum strategy to deliver cardiometabolic health benefits. Researchers should explicitly show between-group differences for HIIT intervention and steady-state exercise or control groups, as the magnitude of difference between HIIT and other exercise modalities is of key interest to public health. There is scope for research to examine the palatability of HIIT as an exercise modality for adolescents through investigating perceived enjoyment during and after HIIT, and consequent long-term exercise adherence.

  15. Muscular soreness following prolonged intermittent high-intensity shuttle running.

    Science.gov (United States)

    Thompson, D; Nicholas, C W; Williams, C

    1999-05-01

    The aim of this study was to examine the impact of prolonged intermittent high-intensity shuttle running on soreness and markers of muscle damage. Sixteen males took part in the study, half of whom were assigned to a running group and half to a resting control group. The exercise protocol involved 90 min of intermittent shuttle running and walking (Loughborough Intermittent Shuttle Test: LIST), reflecting the activity pattern found in multiple-sprint sports such as soccer. Immediately after exercise, there was a significant increase (P < 0.05) in serum activities of creatine kinase and aspartate aminotransferase, and values remained above baseline for 48 h (P < 0.05). Median peak activities of creatine kinase and aspartate aminotransferase occurred 24 h post-exercise and were 774 and 43 U x l(-1), respectively. The intensity of general muscle soreness, and in the specific muscles investigated, was greater than baseline for 72 h after the shuttle test (P < 0.05), peaking 24-48 h post-exercise (P < 0.05). Muscle soreness was not correlated with either creatine kinase or aspartate aminotransferase activity. Soreness was most frequently reported in the hamstrings. Neither soreness nor serum enzyme activity changed in the controls over the 4 day observation period. It appears that unaccustomed performance of prolonged intermittent shuttle running produces a significant increase in both soreness and markers of muscle damage.

  16. Pulmonary Vein Isolation by High Intensity Focused Ultrasound

    Directory of Open Access Journals (Sweden)

    Matthias Antz

    2007-04-01

    Full Text Available Pulmonary vein isolation (PVI using radiofrequency current (RFC ablation is a potentially curative treatment option for patients with atrial fibrillation (AF. The shortcomings of the RFC technology (technically challenging, long procedure times, complications steadily kindle the interest in new energy sources and catheter designs. High intensity focused ultrasound (HIFU has the ability to precisely focus ultrasound waves in a defined area with a high energy density. HIFU balloon catheters (BC positioned at the PV ostia appear to be an ideal tool to transmit the ablation energy in a circumferential manner to the PV ostia and may therefore bear substantial advantage over conventional ablation catheters in PVI procedures. In clinical trials the HIFU BC has shown promising success rates similar to RFC catheter ablation for PVI in patients with AF. However, procedure times are still long and serious complications have been observed. Therefore, it may be a valuable alternative to the conventional techniques in selected patients but further clinical trials have to be initiated.

  17. High intensity interval exercise training in overweight young women.

    Science.gov (United States)

    Sijie, T; Hainai, Y; Fengying, Y; Jianxiong, W

    2012-06-01

    The purpose of this study was intended to evaluate the effects of a high intensity interval training (HIIT) program on the body composition, cardiac function and aerobic capacity in overweight young women. Sixty female university students (aged 19-20, BMI≥25kg/m2 and percentage body fat ≥ 30%) were chosen and then randomly assigned to each of the HIIT group, the moderate intensity continuous training (MICT) group and the non-training control group. The subjects in both the HIIT and MICT groups underwent exercise training five times per week for 12 weeks. In each of the training sessions, the HIIT group performed interval exercises at the individualized heart rate (HR) of 85% of VO2max and separated by brief periods of low intensity activity (HR at 50% of VO2max), while the MICT group did continuous walking and/or jogging at the individualized HR of 50% of VO2max. Both of these exercise training programs produced significant improvements in the subjects' body composition, left ventricular ejection fraction, heart rate at rest, maximal oxygen uptake and ventilatory threshold. However, the HIIT group achieved better results than those in the MICT group, as it was evaluated by the amount of the effect size. The control group did not achieve any change in all of the measured variables. The tangible results achieved by our relatively large groups of homogeneous subjects have demonstrated that the HIIT program is an effective measure for the treatment of young women who are overweight.

  18. Robotic Assisted Laparoscopic Prostatectomy after High Intensity Focused Ultrasound Failure

    Directory of Open Access Journals (Sweden)

    Leon Telis

    2017-01-01

    Full Text Available Background. Prostate cancer is the most common cancer diagnosed in men. As new focal therapies become more popular in treatment of prostate cancer, failure cases requiring salvage therapy with either surgical or other techniques are being reported. Objective. To report the options in treatment of prostate cancer after recurrence or failure of the primary treatment modality. Methods. We report a salvage robotic assisted laparoscopic radical prostatectomy (RALP for prostate cancer recurrence following high intensity focused ultrasound treatment (HIFU in the United States. Results. A 67-year-old man who underwent HIFU treatment for prostate adenocarcinoma 2 years prior was presented with a rising prostate specific antigen of 6.1 ng/mL to our clinic. A biopsy proven recurrent disease in the area of previous treatment documented the failure of treatment. The patient elected to undergo a salvage RALP. The operation time was 159 minutes. The patient was discharged from the hospital on postoperative day 1 with no complications. The catheter was removed on post-op day 10. The patient reserved sexual function and urinary continence. The PSA levels on 6 months’ follow-up are undetectable. Conclusions. Salvage RALP is an effective and safe treatment choice for recurrent prostate adenocarcinoma following failed HIFU treatment if operated by an experienced surgeon.

  19. Production and Studies of Photocathodes for High Intensity Electron Beams

    CERN Document Server

    Chevallay, E; Legros, P; Suberlucq, Guy; Trautner, H

    2000-01-01

    For short, high-intensity electron bunches, alkali-tellurides have proved to be a reliable photo-cathode material. Measurements of lifetimes in an rf gun of the CLIC Test Facility II at field strengths greater than 100 MV/m are presented. Before and after using them in this gun, the spectral response of the CS-Te and Rb-Te cathodes were determined with the help of an optical parametric oscillator. The behaviour of both materials can be described by Spicer's 3-step model. Whereas during the use the threshold for photo-emission in Cs-Te was shifted to higher proton energies, that of Rb-Te did not change. Our latest investigations on the stoichiometric ratio of the components are shown. The preparation of the photo-cathodes was monitored with 320 nm wavelength light , with the aim of improving the measurement sensitivity. The latest results on the protection of Cs-Te cathode surfaces with CsBr against pollution are summarized. New investigations on high mean current production are presented.,

  20. Program for calculating multi-component high-intense ion beam transport

    International Nuclear Information System (INIS)

    Kazarinov, N.Yu.; Prejzendorf, V.A.

    1985-01-01

    The CANAL program for calculating transport of high-intense beams containing ions with different charges in a channel consisting of dipole magnets and quadrupole lenses is described. The equations determined by the method of distribution function momenta and describing coordinate variations of the local mass centres and r.m.s. transverse sizes of beams with different charges form the basis of the calculation. The program is adapted for the CDC-6500 and SM-4 computers. The program functioning is organized in the interactive mode permitting to vary the parameters of any channel element and quickly choose the optimum version in the course of calculation. The calculation time for the CDC-6500 computer for the 30-40 m channel at the integration step of 1 cm is about 1 min. The program is used for calculating the channel for the uranium ion beam injection from the collective accelerator into the heavy-ion synchrotron

  1. Using self-generated harmonics as a diagnostic of high intensity laser-produced plasmas

    International Nuclear Information System (INIS)

    Krushelnick, K; Watts, I; Tatarakis, M; Gopal, A; Wagner, U; Beg, F N; Clark, E L; Clarke, R J; Dangor, A E; Norreys, P A; Wei, M S; Zepf, M

    2002-01-01

    The interaction of high intensity laser pulses (up to I∼10 20 W cm -2 ) with plasmas can generate very high order harmonics of the laser frequency (up to the 75th order have been observed). Measurements of the properties of these harmonics can provide important insights into the plasma conditions which exist during such interactions. For example, observations of the spectrum of the harmonic emission can provide information of the dynamics of the critical surface as well as information on relativistic non-linear optical effects in the plasma. However, most importantly, observations of the polarization properties of the harmonics can provide a method to measure the ultra-strong magnetic fields (greater than 350 MG) which can be generated during these interactions. It is likely that such techniques can be scaled to provide a significant amount of information from experiments at even higher intensities

  2. High-intensity focused ultrasound in the treatment of breast tumours.

    Science.gov (United States)

    Peek, Mirjam C L; Wu, Feng

    2018-01-01

    High-intensity focused ultrasound (HIFU) is a minimally invasive technique that has been used for the treatment of both benign and malignant tumours. With HIFU, an ultrasound (US) beam propagates through soft tissue as a high-frequency pressure wave. The US beam is focused at a small target volume, and due to the energy building up at this site, the temperature rises, causing coagulative necrosis and protein denaturation within a few seconds. HIFU is capable of providing a completely non-invasive treatment without causing damage to the directly adjacent tissues. HIFU can be either guided by US or magnetic resonance imaging (MRI). Guided imaging is used to plan the treatment, detect any movement during the treatment and monitor response in real-time. This review describes the history of HIFU, the HIFU technique, available devices and gives an overview of the published literature in the treatment of benign and malignant breast tumours with HIFU.

  3. Creatine kinase response to high-intensity aerobic exercise in adult-onset muscular dystrophy

    DEFF Research Database (Denmark)

    Andersen, Søren P; Sveen, Marie-Louise; Hansen, Regitze S

    2013-01-01

    We investigated the effect of high-intensity exercise on plasma creatine kinase (CK) in patients with muscular dystrophies.......We investigated the effect of high-intensity exercise on plasma creatine kinase (CK) in patients with muscular dystrophies....

  4. High-intensity lower limb endurance training in chronic respiratory disease

    OpenAIRE

    Tanaka, Takako; Arizono, Shinichi; Hanada, Masatoshi; Senjyu, Hideaki

    2015-01-01

    High-intensity endurance training is mainly undertaken during pulmonary rehabilitation for patients with chronic respiratory disease. High-intensity endurance training is recommended in many clinical management guidelines. High-intensity endurance training involves training generally at an intensity of at 60-80% of the patient’s peak work capacity or higher. The effects of high-intensity lower limb endurance training have mostly been investigated in chronic obstructive pulmonary disease (COPD...

  5. High-intensity positron microprobe at the Thomas Jefferson National Accelerator Facility

    International Nuclear Information System (INIS)

    Golge, S.; Vlahovic, B.; Wojtsekhowski, B.

    2014-01-01

    We present a conceptual design for a novel continuous wave electron-linac based high-intensity high-brightness slow-positron production source with a projected intensity on the order of 10 10  e + /s. Reaching this intensity in our design relies on the transport of positrons (T + below 600 keV) from the electron-positron pair production converter target to a low-radiation and low-temperature area for moderation in a high-efficiency cryogenic rare gas moderator, solid Ne. This design progressed through Monte Carlo optimizations of: electron/positron beam energies and converter target thickness, transport of the e + beam from the converter to the moderator, extraction of the e + beam from the magnetic channel, a synchronized raster system, and moderator efficiency calculations. For the extraction of e + from the magnetic channel, a magnetic field terminator plug prototype has been built and experimental results on the effectiveness of the prototype are presented. The dissipation of the heat away from the converter target and radiation protection measures are also discussed.

  6. Handling of high intensity proton beams at 12 GeV

    International Nuclear Information System (INIS)

    Takasaki, M.; Minakawa, M.; Yamanoi, Y.; Ieiri, M.; Kato, Y.; Ishii, H.; Suzuki, Y.; Suzuki, T.; Tanaka, K.H.

    1990-01-01

    A new counter experimental hall is now being constructed at the KEK (National Laboratory for High Energy Physics, Japan) 12 GeV Proton Synchrotron (KEK-PS). This hall will be completed by the end of 1989, immediately followed by magnet installation. The present report describes the new technical achievements employed at the hall. The most important and essential feature of the equipment is that the beam-handling system is maintenance-free, though in case of need, maintenance should be carried out quickly from a distant location in order to reduce the absorbed dose during the maintenance work. This paper is divided into three parts. The first part outlines the general design concept of the hall, focusing on the handling of high-intensity beams. The second part addresses the development of a quick-disconnect system, focusing on electric power, interlock signals, cooling water, pumping port, and vacuum flange. The third part describes the development of radiation-resistant instruments, focusing on polyimide magnets and cement magnets. (N.K.)

  7. High-intensity positron microprobe at the Thomas Jefferson National Accelerator Facility

    Energy Technology Data Exchange (ETDEWEB)

    Golge, S., E-mail: serkan.golge@nasa.gov; Vlahovic, B. [North Carolina Central University, Durham, North Carolina 27707 (United States); Wojtsekhowski, B. [Jefferson Laboratory, 12000 Jefferson Ave., Newport News, Virginia 23606 (United States)

    2014-06-21

    We present a conceptual design for a novel continuous wave electron-linac based high-intensity high-brightness slow-positron production source with a projected intensity on the order of 10{sup 10 }e{sup +}/s. Reaching this intensity in our design relies on the transport of positrons (T{sub +} below 600 keV) from the electron-positron pair production converter target to a low-radiation and low-temperature area for moderation in a high-efficiency cryogenic rare gas moderator, solid Ne. This design progressed through Monte Carlo optimizations of: electron/positron beam energies and converter target thickness, transport of the e{sup +} beam from the converter to the moderator, extraction of the e{sup +} beam from the magnetic channel, a synchronized raster system, and moderator efficiency calculations. For the extraction of e{sup +} from the magnetic channel, a magnetic field terminator plug prototype has been built and experimental results on the effectiveness of the prototype are presented. The dissipation of the heat away from the converter target and radiation protection measures are also discussed.

  8. Positioning device for MRI-guided high intensity focused ultrasound system

    Energy Technology Data Exchange (ETDEWEB)

    Damianou, Christakis [Frederick Institute of Technology (FIT), Limassol (Cyprus); MEDSONIC, LTD, Limassol (Cyprus); Ioannides, Kleanthis [Polikliniki Igia, Limassol (Cyprus); Milonas, Nicos [Frederick Institute of Technology (FIT), Limassol (Cyprus)

    2008-04-15

    A prototype magnetic resonance imaging (MRI)- compatible positioning device was used to move an MRI-guided high intensity focused ultrasound (HIFU) transducer. The positioning device has three user-controlled degrees of freedom that allow access to various targeted lesions. The positioning device was designed and fabricated using construction materials selected for compatibility with high magnetic fields and fast switching magnetic field gradients encountered inside MRI scanners. The positioning device incorporates only MRI compatible materials such as piezoelectric motors, plastic sheets, brass screws, plastic pulleys and timing belts. The HIFU/MRI system includes the multiple subsystems (a) HIFU system, (b) MR imaging, (c) Positioning device (robot) and associate drivers, (d) temperature measurement, (e) cavitation detection, (f) MRI compatible camera, and (g) Soft ware. The MRI compatibility of the system was successfully demonstrated in a clinical high-field MRI scanner. The ability of the robot to accurately move the transducer thus creating discrete and overlapping lesions in biological tissue was tested successfully. A simple, cost effective, portable positioning device has been developed which can be used in virtually any clinical MRI scanner since it can be sited on the scanner's table. The propagation of HIFU can use either a lateral or superior-inferior approach. Discrete and large lesions were created successfully with reproducible results. (orig.)

  9. High intensive short laser pulse interaction with submicron clusters media

    International Nuclear Information System (INIS)

    Faenov, A. Ya

    2008-01-01

    The interaction of short intense laser pulses with structured targets, such as clusters, exhibits unique features, stemming from the enhanced absorption of the incident laser light compared to solid targets. Due to the increased absorption, these targets are heated significantly, leading to enhanced emission of x rays in the keV range and generation of electrons and multiple charged ions with kinetic energies from tens of keV to tens of MeV. Possible applications of these targets can be an electron/ion source for a table top accelerator, a neutron source for a material damage study, or an x ray source for microscopy or lithography. The overview of recent results, obtained by the high intensive short laser pulse interaction with different submicron clusters media will be presented. High resolution K and L shell spectra of plasma generated by superintense laser irradiation of micron sized Ar, Kr and Xe clusters have been measured with intensity 10"17"-10"19"W/cm"2"and a pulse duration of 30-1000fs. It is found that hot electrons produced by high contrast laser pulses allow the isochoric heating of clusters and shift the ion balance toward the higher charge states, which enhances both the X ray line yield and the ion kinetic energy. Irradiation of clusters, produced from such gas mixture, by a fs Ti:Sa laser pulses allows to enhance the soft X ray radiation of Heβ(665.7eV)and Lyα(653.7eV)of Oxygen in 2-8 times compare with the case of using as targets pure CO"2"or N"2"O clusters and reach values 2.8x10"10"(∼3μJ)and 2.7x10"10"(∼2.9μJ)ph/(sr·pulse), respectively. Nanostructure conventional soft X ray images of 100nm thick Mo and Zr foils in a wide field of view (cm"2"scale)with high spatial resolution (700nm)are obtained using the LiF crystals as soft X ray imaging detectors. When the target used for the ion acceleration studies consists of solid density clusters embedded into the background gas, its irradiation by high intensity laser light makes the target

  10. High-Intensity Events in International Women's Team Handball Matches.

    Science.gov (United States)

    Luteberget, Live S; Spencer, Matt

    2017-01-01

    International women's team handball is a physically demanding sport and is intermittent in nature. The aim of the study was to profile high-intensity events (HIEs) in international women's team handball matches with regard to playing positions. Twenty female national-team handball players were equipped with inertial movement units (OptimEye S5, Catapult Sports, Australia) in 9 official international matches. Players were categorized in 4 different playing positions: backs, wings, pivots, and goalkeepers (GKs). PlayerLoad™, accelerations (Acc), changes of direction (CoD), decelerations (Dec), and the sum of the latter 3, HIEs, were extracted from raw-data files using the manufacturer's software. All Acc, Dec, CoD, and HIEs >2.5 m/s were included. Data were log-transformed and differences were standardized for interpretation of magnitudes and reported with effect-size statistics. Mean numbers of events were 0.7 ± 0.4 Acc/min, 2.3 ± 0.9 Dec/min, and 1.0 ± 0.4 CoD/min. Substantial differences between playing positions, ranging from small to very large, were found in the 3 parameters. Backs showed a most likely greater frequency for HIE/min (5.0 ± 1.1 HIE/min) than all other playing positions. Differences between playing positions were also apparent in PlayerLoad/min. HIEs in international women's team handball are position specific, and the overall intensity depends on the positional role within a team. Specific HIE and intensity profiles from match play provide useful information for a better understanding of the overall game demands and for each playing position.

  11. Outcomes of exertional rhabdomyolysis following high-intensity resistance training.

    Science.gov (United States)

    Huynh, A; Leong, K; Jones, N; Crump, N; Russell, D; Anderson, M; Steinfort, D; Johnson, D F

    2016-05-01

    High-intensity resistance training (HIRT) programmes are increasingly popular amongst personal trainers and those attending gymnasiums. We report the experience of exertional rhabdomyolysis (ER) at two tertiary hospitals in Melbourne, Australia. To compare the clinical outcomes of ER with other causes of rhabdomyolysis. Retrospective cross-sectional study of patients presenting with a serum creatine kinase (CK) of greater than 25 000 units/L from 1 September 2013 to 31 August 2014 at two tertiary referral hospitals in Melbourne, Australia. Records were examined to identify care measures implemented during hospital stay, clinical outcomes during admission and on subsequent follow up. Thirty four cases of rhabdomyolysis with a CK of greater than 25 000 units/L (normal range: 20-180 units/L) were identified during the 12-month study period. Twelve of the 34 cases (35%) had ER with 10 of 12 related to HIRT. No acute kidney injury, intensive care admission or death were seen among those with ER. All cases were managed conservatively, with 11 admitted and 9 receiving intravenous fluids only. In contrast, patients with rhabdomyolysis from other causes experienced significantly higher rates of intensive care admission (64%, P = 0.0002), acute kidney injury (82%, P = 0.0001) and death (27%, P = 0.069). ER resulting from HIRT appears to have a benign course compared with rhabdomyolysis of other aetiologies in patients with a serum CK greater than 25 000 units/L. Conservative management of ER appears to be adequate, although this requires confirmation in future prospective studies. © 2016 Royal Australasian College of Physicians.

  12. Development of a High Intensity Focused Ultrasound (HIFU) Hydrophone System

    International Nuclear Information System (INIS)

    Schafer, Mark E.; Gessert, James

    2009-01-01

    The growing clinical use of High Intensity Focused Ultrasound (HIFU) has driven a need for reliable, reproducible measurements of HIFU acoustic fields. We have previously presented data on a reflective scatterer approach, incorporating several novel features for improved bandwidth, reliability, and reproducibility [Proc. 2005 IEEE Ultrasonics Symposium, 1739-1742]. We now report on several design improvements which have increase the signal to noise ratio of the system, and potentially reduced the cost of implementation. For the scattering element, we now use an artificial sapphire material to provide a more uniform radiating surface. The receiver is a segmented, truncated spherical structure with a 10 cm radius; the scattering element is positioned at the center of the sphere. The receiver is made from 25 micron thick, biaxially stretched PVDF, with a Pt-Au electrode on the front surface. In the new design, a specialized backing material provides the stiffness required to maintain structural stability, while at the same time providing both electrical shielding and ultrasonic absorption. Compared with the previous version, the new receiver design has improved the noise performance by 8-12 dB; the new scattering sphere has reduced the scattering loss by another 14 dB, producing an effective sensitivity of -298 dB re 1 microVolt/Pa. The design trade-off still involves receiver sensitivity with effective spot size, and signal distortion from the scatter structure. However, the reduced cost and improved repeatability of the new scatter approach makes the overall design more robust for routine waveform measurements of HIFU systems.

  13. Inelastic scattering in condensed matter with high intensity Moessbauer radiation

    International Nuclear Information System (INIS)

    Yelon, W.B.; Schupp, G.

    1990-10-01

    We give a progress report for the work which has been carried out in the last three years with DOE support. A facility for high-intensity Moessbauer scattering is now fully operational at the University of Missouri Research Reactor (MURR) as well as facility at Purdue, using special isotopes produced at MURR. High precision, fundamental Moessbauer effect studies have been carried out using scattering to filter the unwanted radiation. These have led to a new Fourier transform method for describing Moessbauer effect (ME) lineshape and a direct method of fitting ME data to the convolution integral. These methods allow complete correction for source resonance self absorption (SRSA) and the accurate representation of interference effects that add an asymmetric component to the ME lines. We have begun applying these techniques to attenuated ME sources whose central peak has been attenuated by stationary resonant absorbers, to more precisely determine interference parameters and line-shape behavior in the resonance asymptotic region. This analysis is important to both the fundamental ME studies and to scattering studies for which a deconvolution is essential for extracting the correct recoilless fractions and interference parameters. A number of scattering studies have been successfully carried out including a study of the thermal diffuse scattering in Si, which led to an analysis of the resolution function for gamma-ray scattering. Also studied was the anharmonic motion in Na and the satellite reflection Debye-Waller factor in TaS 2 , which indicate phason rather than phonon behavior. We have begun quasielastic diffusion studies in viscous liquids and current results are summarized. These advances, coupled to our improvements in MIcrofoil Conversion Electron spectroscopy lay the foundation for the proposed research outlined in this request for a three-year renewal of DOE support

  14. Gamma scattering in condensed matter with high intensity Moessbauer radiation

    International Nuclear Information System (INIS)

    1990-01-01

    We give a progress report for the work which has been carried out in the last three years with DOE support. A facility for high-intensity Moessbauer scattering is now fully operational at the University of Missouri Research Reactor (MURR) as well as a facility at Purdue, using special isotopes produced at MURR. High precision, fundamental Moessbauer effect studies have been carried out using scattering to filter the unwanted radiation. These have led to a new Fourier transform method for describing Moessbauer effect (ME) lineshape and a direct method of fitting ME data to the convolution integral. These methods allow complete correction for source resonance self absorption (SRSA) and the accurate representation of interference effects that add an asymmetric component to the ME lines. We have begun applying these techniques to attenuated ME sources whose central peak has been attenuated by stationary resonant absorbers, to more precisely determine interference parameters and line-shape behavior in the resonance asymptotic region. This analysis is important to both the fundamental ME studies and to scattering studies for which a deconvolution is essential for extracting the correct recoilless fractions and interference parameters. A number of scattering studies have been successfully carried out including a study of the thermal diffuse scattering in Si, which led to an analysis of the resolution function for gamma-ray scattering. Also studied was the anharmonic motion in Na and the satellite reflection Debye-Waller factor in TaS 2 , which indicate phason rather than phonon behavior. We have begun quasielastic diffusion studies in viscous liquids and current results are summarized. These advances, coupled to our improvements in MIcrofoil Conversion Electron spectroscopy lay the foundation for the proposed research outlined in this request for a three-year renewal of DOE support

  15. Inelastic scattering in condensed matter with high intensity moessbauer radiation

    International Nuclear Information System (INIS)

    Yelon, W.B.; Schupp, G.

    1991-05-01

    We give a progress report for the work which has been carried out in the last three years with DOE support. A facility for high-intensity Moessbauer scattering is not fully operational at the University of Missouri Research Reactor (MURR) as well as a facility at Purdue, using special isotopes produced at MURR. High precision, fundamental Moessbauer effect studies have been carried out using Bragg scattering filters to suppress unwanted radiation. These have led to a Fourier transform method for describing Moessbauer effect (ME) lineshape and a direct method of fitting ME data to the convolution integral. These methods allow complete correction for source resonance self absorption and the accurate representation of interference effects that add an asymmetric component to the ME lines. We have begun applying these techniques to attenuated ME sources whose central peak has been attenuated by stationary resonant absorbers, to make a novel independent determination of interference parameters and line-shape behavior in the resonance asymptotic region. This analysis is important to both fundamental ME studies and to scattering studies for which a deconvolution is essential for extracting the correct recoilless fractions and interference parameters. A number of scattering studies have been successfully carried out including a study of the thermal diffuse scattering in Si, which led to an analysis of the resolution function for gamma-ray scattering. Also studied was the anharmonic motion in Na metal and the charge density wave satellite reflection Debye-Waller factor in TaS 2 , which indicate phason rather than phonon behavior. Using a specially constructed sample cell which enables us to vary temperatures from -10 C to 110 C, we have begun quasielastic diffusion studies in viscous liquids and current results are summarized. Included are the temperature and Q dependence of the scattering in pentadecane and diffusion in glycerol

  16. High-intensity focused ultrasound ablation around the tubing.

    Science.gov (United States)

    Siu, Jun Yang; Liu, Chenhui; Zhou, Yufeng

    2017-01-01

    High-intensity focused ultrasound (HIFU) has been emerging as an effective and noninvasive modality in cancer treatment with very promising clinical results. However, a small vessel in the focal region could be ruptured, which is an important concern for the safety of HIFU ablation. In this study, lesion formation in the polyacrylamide gel phantom embedded with different tubing (inner diameters of 0.76 mm and 3 mm) at varied flow speeds (17-339 cm/s) by HIFU ablation was photographically recorded. Produced lesions have decreased length (~30%) but slightly increased width (~6%) in comparison to that without the embedded tubing. Meanwhile, bubble activities during the exposures were measured by passive cavitation detection (PCD) at the varied pulse repetition frequency (PRF, 10-30 Hz) and duty cycle (DC, 10%-20%) of the HIFU bursts. High DC and low flow speed were found to produce stronger bubble cavitation whereas no significant influence of the PRF. In addition, high-speed photography illustrated that the rupture of tubing was produced consistently after the first HIFU burst within 20 ms and then multiple bubbles would penetrate into the intraluminal space of tubing through the rupture site by the acoustic radiation force. Alignment of HIFU focus to the anterior surface, middle, and posterior surface of tubing led to different characteristics of vessel rupture and bubble introduction. In summary, HIFU-induced vessel rupture is possible as shown in this phantom study; produced lesion sizes and shapes are dependent on the focus alignment to the tubing, flow speed, and tubing properties; and bubble cavitation and the formation liquid jet may be one of the major mechanisms of tubing rupture as shown in the high-speed photography.

  17. Energy compensation after sprint- and high-intensity interval training.

    Science.gov (United States)

    Schubert, Matthew M; Palumbo, Elyse; Seay, Rebekah F; Spain, Katie K; Clarke, Holly E

    2017-01-01

    Many individuals lose less weight than expected in response to exercise interventions when considering the increased energy expenditure of exercise (ExEE). This is due to energy compensation in response to ExEE, which may include increases in energy intake (EI) and decreases in non-exercise physical activity (NEPA). We examined the degree of energy compensation in healthy young men and women in response to interval training. Data were examined from a prior study in which 24 participants (mean age, BMI, & VO2max = 28 yrs, 27.7 kg•m-2, and 32 mL∙kg-1∙min-1) completed either 4 weeks of sprint-interval training or high-intensity interval training. Energy compensation was calculated from changes in body composition (air displacement plethysmography) and exercise energy expenditure was calculated from mean heart rate based on the heart rate-VO2 relationship. Differences between high (≥ 100%) and low (high levels of energy compensation gained fat mass, lost fat-free mass, and had lower change scores for VO2max and NEPA. Linear regression results indicated that lower levels of energy compensation were associated with increases in ΔVO2max (p interval training. In agreement with prior work, increases in ΔVO2max and ΔNEPA were associated with lower energy compensation. Future studies should focus on identifying if a dose-response relationship for energy compensation exists in response to interval training, and what underlying mechanisms and participant traits contribute to the large variation between individuals.

  18. Topics in high-intensity laser plasma interaction

    International Nuclear Information System (INIS)

    Leemans, W.P.

    1991-01-01

    The interaction of high intensity laser pulses with pre-formed and laser-produced plasmas is studied. Through experiments and simulations we have investigated stimulated Compton scattering in preformed plasmas and the plasma physics aspects of tunnel-ionized gases. A theoretical study is presented on the nonlinear dynamics of relativistic plasma waves driven by colinear optical mixing. The electron density-fluctuation spectra induced by stimulated Compton scattering have been directly observed for the first time. A CO2 laser was focused into pre-formed plasmas with densities n(e) varied from 0.4-6 x 10(exp 16) cu cm. The fluctuations corresponding to backscatter were probed using Thomson scattering. At low n(e), the scattered spectra peak at a frequency shift Delta omega is approximately kv e and appears to be in a linear regime. At the highest n(e), a nonlinear saturation of the SCS instability is observed due to a self-induced perturbation of the electron distribution function. Tunnel-ionized plasmas have been studied through experiments and particle simulations. Experimentally, qualitative evidence for plasma temperature control by varying the laser polarization was obtained by the measurement of stimulated Compton scattering fluctuation spectra and x-ray emission from such plasmas. A higher parallel temperature than expected from the single-particle tunneling model was observed. Simulations indicate that stochastic heating and the Weibel instability play an important role in plasma heating in all directions and isotropization. The non-linear dynamics associated with beatwave (Delta omega, Delta k) excited long wavelength plasma waves in the presence of strong, short wavelength density ripple have been examined, using the relativistic Lagrangian oscillator model. This model shows period doubling that roughly follows Feigenbaum scaling, and a transition to chaos

  19. High Intensity High Charge State ECR Ion Sources

    CERN Document Server

    Leitner, Daniela

    2005-01-01

    The next-generation heavy ion beam accelerators such as the proposed Rare Isotope Accelerator (RIA), the Radioactive Ion Beam Factory at RIKEN, the GSI upgrade project, the LHC-upgrade, and IMP in Lanzhou require a great variety of high charge state ion beams with a magnitude higher beam intensity than currently achievable. High performance Electron Cyclotron Resonance (ECR) ion sources can provide the flexibility since they can routinely produce beams from hydrogen to uranium. Over the last three decades, ECR ion sources have continued improving the available ion beam intensities by increasing the magnetic fields and ECR heating frequencies to enhance the confinement and the plasma density. With advances in superconducting magnet technology, a new generation of high field superconducting sources is now emerging, designed to meet the requirements of these next generation accelerator projects. The talk will briefly review the field of high performance ECR ion sources and the latest developments for high intens...

  20. Advanced approaches to high intensity laser-driven ion acceleration

    International Nuclear Information System (INIS)

    Henig, Andreas

    2010-01-01

    Since the pioneering work that was carried out 10 years ago, the generation of highly energetic ion beams from laser-plasma interactions has been investigated in much detail in the regime of target normal sheath acceleration (TNSA). Creation of ion beams with small longitudinal and transverse emittance and energies extending up to tens of MeV fueled visions of compact, laser-driven ion sources for applications such as ion beam therapy of tumors or fast ignition inertial con finement fusion. However, new pathways are of crucial importance to push the current limits of laser-generated ion beams further towards parameters necessary for those applications. The presented PhD work was intended to develop and explore advanced approaches to high intensity laser-driven ion acceleration that reach beyond TNSA. In this spirit, ion acceleration from two novel target systems was investigated, namely mass-limited microspheres and nm-thin, free-standing diamond-like carbon (DLC) foils. Using such ultrathin foils, a new regime of ion acceleration was found where the laser transfers energy to all electrons located within the focal volume. While for TNSA the accelerating electric field is stationary and ion acceleration is spatially separated from laser absorption into electrons, now a localized longitudinal field enhancement is present that co-propagates with the ions as the accompanying laser pulse pushes the electrons forward. Unprecedented maximum ion energies were obtained, reaching beyond 0.5 GeV for carbon C 6+ and thus exceeding previous TNSA results by about one order of magnitude. When changing the laser polarization to circular, electron heating and expansion were shown to be efficiently suppressed, resulting for the first time in a phase-stable acceleration that is dominated by the laser radiation pressure which led to the observation of a peaked C 6+ spectrum. Compared to quasi-monoenergetic ion beam generation within the TNSA regime, a more than 40 times increase in

  1. Frequency conversion of high-intensity, femtosecond laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Banks, P S

    1997-06-01

    Almost since the invention of the laser, frequency conversion of optical pulses via non- linear processes has been an area of active interest. However, third harmonic generation using ~(~1 (THG) in solids is an area that has not received much attention because of ma- terial damage limits. Recently, the short, high-intensity pulses possible with chirped-pulse amplification (CPA) laser systems allow the use of intensities on the order of 1 TW/cm2 in thin solids without damage. As a light source to examine single-crystal THG in solids and other high field inter- actions, the design and construction of a Ti:sapphire-based CPA laser system capable of ultimately producing peak powers of 100 TW is presented. Of special interest is a novel, all-reflective pulse stretcher design which can stretch a pulse temporally by a factor of 20,000. The stretcher design can also compensate for the added material dispersion due to propagation through the amplifier chain and produce transform-limited 45 fs pulses upon compression. A series of laser-pumped amplifiers brings the peak power up to the terawatt level at 10 Hz, and the design calls for additional amplifiers to bring the power level to the 100 TW level for single shot operation. The theory for frequency conversion of these short pulses is presented, focusing on conversion to the third harmonic in single crystals of BBO, KD*P, and d-LAP (deuterated I-arginine phosphate). Conversion efficiencies of up to 6% are obtained with 500 fs pulses at 1053 nm in a 3 mm thick BBO crystal at 200 GW/cm 2. Contributions to this process by unphasematched, cascaded second harmonic generation and sum frequency generation are shown to be very significant. The angular relationship between the two orders is used to measure the tensor elements of C = xt3)/4 with Crs = -1.8 x 1O-23 m2/V2 and .15Cri + .54Crs = 4.0 x 1O-23 m2/V2. Conversion efficiency in d-LAP is about 20% that in BBO and conversion efficiency in KD*P is 1% that of BBO. It is calculated

  2. Energy compensation after sprint- and high-intensity interval training.

    Directory of Open Access Journals (Sweden)

    Matthew M Schubert

    Full Text Available Many individuals lose less weight than expected in response to exercise interventions when considering the increased energy expenditure of exercise (ExEE. This is due to energy compensation in response to ExEE, which may include increases in energy intake (EI and decreases in non-exercise physical activity (NEPA. We examined the degree of energy compensation in healthy young men and women in response to interval training.Data were examined from a prior study in which 24 participants (mean age, BMI, & VO2max = 28 yrs, 27.7 kg•m-2, and 32 mL∙kg-1∙min-1 completed either 4 weeks of sprint-interval training or high-intensity interval training. Energy compensation was calculated from changes in body composition (air displacement plethysmography and exercise energy expenditure was calculated from mean heart rate based on the heart rate-VO2 relationship. Differences between high (≥ 100% and low (< 100% levels of energy compensation were assessed. Linear regressions were utilized to determine associations between energy compensation and ΔVO2max, ΔEI, ΔNEPA, and Δresting metabolic rate.Very large individual differences in energy compensation were noted. In comparison to individuals with low levels of compensation, individuals with high levels of energy compensation gained fat mass, lost fat-free mass, and had lower change scores for VO2max and NEPA. Linear regression results indicated that lower levels of energy compensation were associated with increases in ΔVO2max (p < 0.001 and ΔNEPA (p < 0.001.Considerable variation exists in response to short-term, low dose interval training. In agreement with prior work, increases in ΔVO2max and ΔNEPA were associated with lower energy compensation. Future studies should focus on identifying if a dose-response relationship for energy compensation exists in response to interval training, and what underlying mechanisms and participant traits contribute to the large variation between individuals.

  3. Advanced approaches to high intensity laser-driven ion acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Henig, Andreas

    2010-04-26

    Since the pioneering work that was carried out 10 years ago, the generation of highly energetic ion beams from laser-plasma interactions has been investigated in much detail in the regime of target normal sheath acceleration (TNSA). Creation of ion beams with small longitudinal and transverse emittance and energies extending up to tens of MeV fueled visions of compact, laser-driven ion sources for applications such as ion beam therapy of tumors or fast ignition inertial con finement fusion. However, new pathways are of crucial importance to push the current limits of laser-generated ion beams further towards parameters necessary for those applications. The presented PhD work was intended to develop and explore advanced approaches to high intensity laser-driven ion acceleration that reach beyond TNSA. In this spirit, ion acceleration from two novel target systems was investigated, namely mass-limited microspheres and nm-thin, free-standing diamond-like carbon (DLC) foils. Using such ultrathin foils, a new regime of ion acceleration was found where the laser transfers energy to all electrons located within the focal volume. While for TNSA the accelerating electric field is stationary and ion acceleration is spatially separated from laser absorption into electrons, now a localized longitudinal field enhancement is present that co-propagates with the ions as the accompanying laser pulse pushes the electrons forward. Unprecedented maximum ion energies were obtained, reaching beyond 0.5 GeV for carbon C{sup 6+} and thus exceeding previous TNSA results by about one order of magnitude. When changing the laser polarization to circular, electron heating and expansion were shown to be efficiently suppressed, resulting for the first time in a phase-stable acceleration that is dominated by the laser radiation pressure which led to the observation of a peaked C{sup 6+} spectrum. Compared to quasi-monoenergetic ion beam generation within the TNSA regime, a more than 40 times

  4. High intensity proton operation at the Brookhaven AGS accelerator complex

    International Nuclear Information System (INIS)

    Ahrens, L.A.; Blaskiewicz, M.; Bleser, E.; Brennan, J.M.; Gardner, C.; Glenn, J.W.; Onillon, E.; Reece, R.K.; Roser, T.; Soukas, A.

    1994-01-01

    With the completion of the AGS rf upgrade, and the implementation of a transition open-quotes jumpclose quotes, all of accelerator systems were in place in 1994 to allow acceleration of the proton intensity available from the AGS Booster injector to AGS extraction energy and delivery to the high energy users. Beam commissioning results with these new systems are presented. Progress in identifying and overcoming other obstacles to higher intensity are given. These include a careful exploration of the stopband strengths present on the AGS injection magnetic porch, and implementation of the AGS single bunch transverse dampers throughout the acceleration cycle

  5. Applications of super - high intensity lasers in nuclear engineering

    International Nuclear Information System (INIS)

    Salomaa, R.; Hakola, A.; Santala, M.

    2007-01-01

    Laser-plasma interactions arising when a super intense ultrashort laser pulse impinges a solid target creates intense partly collimated and energy resolved photons, high energy electron and protons and neutrons. In addition the plasma plume can generate huge magnetic and electric fields. Also ultra short X-ray pulses are created. We have participated in some of such experiments at Rutherford and Max-Planck Institute and assessed the applications of such kind as laser-driven accelerators. This paper discusses applications in nuclear engineering (neutron sources, isotope separation, fast ignition and transmutation, etc). In particular the potential for extreme time resolution and to partial energy resolution are assessed

  6. High-intensity pulsed beam source with tunable operation mode

    Science.gov (United States)

    Nashilevskiy, A. V.; Kanaev, G. G.; Ezhov, V. V.; Shamanin, V. I.

    2017-05-01

    The report presents the design of an electron and an ion pulsed accelerator. The powerful high-voltage pulse generator of the accelerator and the vacuum bushing insulator is able to change the polarity of the output voltage. The low-inductance matching transformer provides an increase in the DFL output impedance by 4 times. The generator based on a high voltage pulse transformer and a pseudo spark switch is applied for DFL charging. The high-impedance magnetically insulated focusing diode with Br magnetic field and the “passive” anode was used to realize the ion beam generation mode. The plasma is formed on the surface of the anode caused by an electrical breakdown at the voltage edge pulse; as a result, the carbon ion and proton beam is generated. This beam has the following parameters: the current density is about 400 A/cm2 (in focus): the applied voltage is up to 450 kV. The accelerator is designed for the research on the interaction of the charged particle pulsed beams with materials and for the development of technological processes of a material modification.

  7. Quality of MR thermometry during palliative MR-guided high-intensity focused ultrasound (MR-HIFU) treatment of bone metastases

    NARCIS (Netherlands)

    Lam, Mie K; Huisman, Merel; Nijenhuis, Robbert J; van den Bosch, Maurice; Viergever, Max A; Moonen, Chrit Tw; Bartels, LW

    2015-01-01

    BACKGROUND: Magnetic resonance (MR)-guided high-intensity focused ultrasound has emerged as a clinical option for palliative treatment of painful bone metastases, with MR thermometry (MRT) used for treatment monitoring. In this study, the general image quality of the MRT was assessed in terms of

  8. Volumetric MR-Guided High-Intensity Focused Ultrasound with Direct Skin Cooling for the Treatment of Symptomatic Uterine Fibroids : Proof-of-Concept Study

    NARCIS (Netherlands)

    Ikink, Marlijne E; van Breugel, Johanna M M; Schubert, Gerald; Nijenhuis, Robbert J; Bartels, LW; Moonen, Chrit T W; van den Bosch, Maurice A A J

    2015-01-01

    Objective. To prospectively assess the safety and technical feasibility of volumetric magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) ablation with direct skin cooling (DISC) during treatment of uterine fibroids. Methods. In this proof-of-concept study, eight patients were

  9. Quantification of liquid products from the electroreduction of CO2 and CO using static headspace-gas chromatography and nuclear magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Bertheussen, Erlend; Abghoui, Younes; Jovanov, Zarko P.

    2017-01-01

    Static headspace-gas chromatography (HS-GC) useful for ex-situ liquid product analysis. Could complement high-performance liquid chromatography and NMR spectroscopy. Particularly high sensitivity towards compounds with high vapor pressure. Detection limits below 0.5μM were shown for acetaldehyde...

  10. H- Ion Sources for High Intensity Proton Drivers

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Rolland Paul [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dudnikov, Vadim [Muons, Inc., Batavia, IL (United States)

    2015-02-20

    Existing RF Surface Plasma Sources (SPS) for accelerators have specific efficiencies for H+ and H- ion generation around 3 to 5 mA/cm2 per kW, where about 50 kW of RF power is typically needed for 50 mA beam current production. The Saddle Antenna (SA) SPS described here was developed to improve H- ion production efficiency, reliability and availability for pulsed operation as used in the ORNL Spallation Neutron Source . At low RF power, the efficiency of positive ion generation in the plasma has been improved to 200 mA/cm2 per kW of RF power at 13.56 MHz. Initial cesiation of the SPS was performed by heating cesium chromate cartridges by discharge as was done in the very first versions of the SPS. A small oven to decompose cesium compounds and alloys was developed and tested. After cesiation, the current of negative ions to the collector was increased from 1 mA to 10 mA with RF power 1.5 kW in the plasma (6 mm diameter emission aperture) and up to 30 mA with 4 kW RF power in the plasma and 250 Gauss longitudinal magnetic field. The ratio of electron current to negative ion current was improved from 30 to 2. Stable generation of H- beam without intensity degradation was demonstrated in the aluminum nitride (AlN) discharge chamber for 32 days at high discharge power in an RF SPS with an external antenna. Some modifications were made to improve the cooling and cesiation stability. The extracted collector current can be increased significantly by optimizing the longitudinal magnetic field in the discharge chamber. While this project demonstrated the advantages of the pulsed version of the SA RF SPS as an upgrade to the ORNL Spallation Neutron Source, it led to a possibility for upgrades to CW machines like the many cyclotrons used for commercial applications. Four appendices contain important details of the work carried out under this grant.

  11. High intensity proton beam transportation through fringe field of 70 MeV compact cyclotron to beam line targets

    Science.gov (United States)

    Zhang, Xu; Li, Ming; Wei, Sumin; Xing, Jiansheng; Hu, Yueming; Johnson, Richard R.; Piazza, Leandro; Ryjkov, Vladimir

    2016-06-01

    From the stripping points, the high intensity proton beam of a compact cyclotron travels through the fringe field area of the machine to the combination magnet. Starting from there the beams with various energy is transferred to the switching magnet for distribution to the beam line targets. In the design of the extraction and transport system for the compact proton cyclotron facilities, such as the 70 MeV in France and the 100 MeV in China, the space charge effect as the beam crosses the fringe field has not been previously considered; neither has the impact on transverse beam envelope coupled from the longitudinal direction. Those have been concerned much more with the higher beam-power because of the beam loss problem. In this paper, based on the mapping data of 70 MeV cyclotron including the fringe field by BEST Cyclotron Inc (BEST) and combination magnet field by China Institute of Atomic Energy (CIAE), the beam extraction and transport are investigated for the 70 MeV cyclotron used on the SPES project at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro (INFN-LNL). The study includes the space charge effect and longitudinal and transverse coupling mentioned above, as well as the matching of beam optics using the beam line for medical isotope production as an example. In addition, the designs of the ±45° switching magnets and the 60° bending magnet for the extracted beam with the energy from 35 MeV to 70 MeV have been made. Parts of the construction and field measurements of those magnets have been done as well. The current result shows that, the design considers the complexity of the compact cyclotron extraction area and fits the requirements of the extraction and transport for high intensity proton beam, especially at mA intensity levels.

  12. High intensity proton beam transportation through fringe field of 70 MeV compact cyclotron to beam line targets

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xu, E-mail: emmazhang103@gmail.com [China Institute of Atomic Energy (China); Li, Ming; Wei, Sumin; Xing, Jiansheng; Hu, Yueming [China Institute of Atomic Energy (China); Johnson, Richard R.; Piazza, Leandro; Ryjkov, Vladimir [BEST Cyclotron Inc (Canada)

    2016-06-01

    From the stripping points, the high intensity proton beam of a compact cyclotron travels through the fringe field area of the machine to the combination magnet. Starting from there the beams with various energy is transferred to the switching magnet for distribution to the beam line targets. In the design of the extraction and transport system for the compact proton cyclotron facilities, such as the 70 MeV in France and the 100 MeV in China, the space charge effect as the beam crosses the fringe field has not been previously considered; neither has the impact on transverse beam envelope coupled from the longitudinal direction. Those have been concerned much more with the higher beam-power because of the beam loss problem. In this paper, based on the mapping data of 70 MeV cyclotron including the fringe field by BEST Cyclotron Inc (BEST) and combination magnet field by China Institute of Atomic Energy (CIAE), the beam extraction and transport are investigated for the 70 MeV cyclotron used on the SPES project at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro (INFN–LNL). The study includes the space charge effect and longitudinal and transverse coupling mentioned above, as well as the matching of beam optics using the beam line for medical isotope production as an example. In addition, the designs of the ±45° switching magnets and the 60° bending magnet for the extracted beam with the energy from 35 MeV to 70 MeV have been made. Parts of the construction and field measurements of those magnets have been done as well. The current result shows that, the design considers the complexity of the compact cyclotron extraction area and fits the requirements of the extraction and transport for high intensity proton beam, especially at mA intensity levels.

  13. High-intensity light-ion beam research at NRL

    International Nuclear Information System (INIS)

    Cooperstein, G.; Colombant, D.G.; Barker, R.J.

    1982-01-01

    High-brightness proton beams (.4 MA, 1 MV) have recently been extracted from 20 cm 2 axial pinch-reflex diodes (PRDs) mounted on the NRL Gamble II generator. A source power brightness of GT 10 TW/cm 2 rad 2 was achieved in these experiments. A new barrel-shaped equitorial PRD that can be coupled to PBFA-II has also been operated on Gamble II and has demonstrated 50% proton efficiency with predominately azimuthally-symmetric charged-particle flow. In other experiments the stopping power of deuterons in hot plasmas was measured using a PRD on Gamble II. Results show about 40% enhancement in stopping power over that in cold targets when the beam was focused to about .25 MA/cm 2 . Research is also being performed on transporting ion beams in large-diameter channels (>= 2.5 cm) and on a post-transport, plasma-filled, magnetic-focusing section to bring the beam to pellet dimensions. (author)

  14. Interaction of High Intensity Electromagnetic Waves with Plasmas: Final Report

    International Nuclear Information System (INIS)

    Shvets, G.

    2008-01-01

    The focus of our work during the duration of this grant was on the following areas: (a) the fundamental plasma physics of intense laser-plasma interactions, including the nonlinear excitation of plasma waves for accelerator applications, as well as the recently discovered by us phenomenon of the relativistic bi-stability of relativistic plasma waves driven by a laser beatwave; (b) interaction of high power microwave beams with magnetized plasma, including some of the recently discovered by us phenomena such as the Undulator Induced Transparency (UIT) as well as the new approaches to dynamic manipulation of microwave pulses; (c) investigations of the multi-color laser pulse interactions in the plasma, including the recently discovered by us phenomenon of Electromagnetic Cascading (EC) and the effect of the EC of three-dimensional dynamics of laser pulses (enhanced/suppressed selffocusing etc.); (d) interaction of high-current electron beams with the ambient plasma in the context of Fast Ignitor (FI) physics, with the emphasis on the nonlinear dynamics of the Weibel instability and beam filamentation.

  15. Static Einstein--Maxwell field equations

    International Nuclear Information System (INIS)

    Das, A.

    1979-01-01

    The static Einstein--Maxwell field equations are investigated in the presence of both electric and magnetic fields. The sources or bodies are assumed to be of finite size and to not affect the connectivity of the associated space. Furthermore, electromagnetic and metric fields are assumed to have reasonable differentiabilities. It is then proved that the electric and magnetic field vectors are constant multiples of one another. Moreover, the static Einstein--Maxwell equations reduce to the static magnetovac case. If, furthermore, the variational derivation of the Einstein--Maxwell equations is assumed, then both the total electric and magnetic charge of each body must vanish. As a physical consequence it is pointed out that if a suspended magnet be electrically charged then it must experience a purely general relativistic torque

  16. Self-Consistent simulations of High-Intensity Beams and E-Clouds with WARP POSINST

    International Nuclear Information System (INIS)

    Vay, J.-L.; Friendman, A.; Grote, D.P.

    2006-01-01

    We have developed a new, comprehensive set of simulation tools aimed at modeling the interaction of intense ion beams and electron clouds (e-clouds). The set contains the 3-D accelerator PIC codeWARP and the 2-D ''slice'' ecloud code POSINST, as well as a merger of the two, augmented by new modules for impact ionization and neutral gas generation. The new capability runs on workstations or parallel supercomputers and contains advanced features such as mesh refinement, disparate adaptive time stepping, and a new ''drift-Lorentz'' particle mover for tracking charged particles in magnetic fields using large time steps. It is being applied to the modeling of ion beams (1 MeV, 180 mA, K+) for heavy ion inertial fusion and warm dense matter studies, as they interact with electron clouds in the High-Current Experiment (HCX). In earlier papers, we described the capabilities and presented recent simulation results with detailed comparisons against the HCX experiment, as well as their application (in a different regime) to the modeling of e-clouds in the Large Hadron Collider (LHC). We concentrate here on the description of the implementation of the ''quasi-static'' mode of operation, for comparison with other codes, and introduce a new consideration on the estimate of computing time between the quasi-static and the fully self-consistent modes

  17. Low preveance ion source bridges low and high intensities in ion implantation

    International Nuclear Information System (INIS)

    Orr, F.D.; Mayhall, D.

    1976-01-01

    The Low Perveance Ion Source developed by Accelerators, Inc. offers the Semiconductor Industry the advantage of processing medium to high intensity implants on a system which will also implant 200 to 300 wafers an hour at MOS doses. Stable source beam currents can be varied over three orders of magnitude by variation of a single source parameter. This source uses a new computer designed Low Perveance extraction optics which is completely new to the Ion Implantation Industry. Test data and calculations are shown which define the versatility of this system. Scanned currents from 1 microamp to 400 microamps allow for a variety of production processing. Beam characteristics feature low energy spread (less than 10 eV) and low divergence (less than 3 degrees). Beam control optics consist of a double focusing analyzing magnet and two triplet quadrupoles. The source may be fitted with an oven for feeding of solid materials and analyzed beam currents in the milliamp range for development purposes. The batch processing, hybrid scanning end station is most applicable for high current beams as well as high volume batch processings of MOS Implants. Results of development work toward increased currents using both solid and gas feed material with the Low Perveance source are presented. System improvements including Accel-Decel and a third extraction element are discussed

  18. Performance of Multiplexed XY Resistive Micromegas detectors in a high intensity beam

    Science.gov (United States)

    Banerjee, D.; Burtsev, V.; Chumakov, A.; Cooke, D.; Depero, E.; Dermenev, A. V.; Donskov, S. V.; Dubinin, F.; Dusaev, R. R.; Emmenegger, S.; Fabich, A.; Frolov, V. N.; Gardikiotis, A.; Gninenko, S. N.; Hösgen, M.; Karneyeu, A. E.; Ketzer, B.; Kirsanov, M. M.; Konorov, I. V.; Kramarenko, V. A.; Kuleshov, S. V.; Levchenko, E.; Lyubovitskij, V. E.; Lysan, V.; Mamon, S.; Matveev, V. A.; Mikhailov, Yu. V.; Myalkovskiy, V. V.; Peshekhonov, V. D.; Peshekhonov, D. V.; Polyakov, V. A.; Radics, B.; Rubbia, A.; Samoylenko, V. D.; Tikhomirov, V. O.; Tlisov, D. A.; Toropin, A. N.; Vasilishin, B.; Arenas, G. Vasquez; Ulloa, P.; Crivelli, P.

    2018-02-01

    We present the performance of multiplexed XY resistive Micromegas detectors tested in the CERN SPS 100 GeV/c electron beam at intensities up to 3 . 3 × 105e- /(s ṡcm2) . So far, all studies with multiplexed Micromegas have only been reported for tests with radioactive sources and cosmic rays. The use of multiplexed modules in high intensity environments was not explored due to the effect of ambiguities in the reconstruction of the hit point caused by the multiplexing feature. For the specific mapping and beam intensities analyzed in this work with a multiplexing factor of five, more than 50% level of ambiguity is introduced due to particle pile-up as well as fake clusters due to the mapping feature. Our results prove that by using the additional information of cluster size and integrated charge from the signal clusters induced on the XY strips, the ambiguities can be reduced to a level below 2%. The tested detectors are used in the CERN NA64 experiment for tracking the incoming particles bending in a magnetic field in order to reconstruct their momentum. The average hit detection efficiency of each module was found to be ∼96% at the highest beam intensities. By using four modules a tracking resolution of 1.1% was obtained with ∼85% combined tracking efficiency.

  19. Physics design of a 70 MeV high intensity cyclotron, CYCIAE-70

    International Nuclear Information System (INIS)

    Zhang Tianjue; An Shizhong; Wang Chuan; Yin Zhiguo; Wei Sumin; Li Ming; Yang Jianjun; Ji Bin; Jia Xianlu; Zhong Junqing; Yang Fang

    2011-01-01

    This paper introduces the physics design of a 70 MeV high intensity cyclotron at China Institute of Atomic Energy (CIAE), which is aimed for multiple uses including radioactive ion-beam (RIB) production. The machine adopts a compact structure of four straight sectors, capable of accelerating two kinds of beams, i.e. H − and D − . The proton and deuteron beam will be extracted in dual opposite directions by charge exchange stripping devices. The energy of the extracted proton beam is in the range 35–70 MeV with an intensity up to 700 μA. The corresponding values for the deuteron beam are 18–33 MeV and 40 μA. This paper will present the main characteristics and parameters in the design of the 70 MeV cyclotron, the results of the basic beam dynamics study, as well as the physics in the design of the different systems, including the main magnet, RF, injection and extraction systems, etc.

  20. On the choice of electromagnetic model for short high-intensity arcs, applied to welding

    International Nuclear Information System (INIS)

    Choquet, Isabelle; Shirvan, Alireza Javidi; Nilsson, Håkan

    2012-01-01

    We have considered four different approaches for modelling the electromagnetic fields of high-intensity electric arcs: (i) three-dimensional, (ii) two-dimensional axi-symmetric, (iii) the electric potential formulation and (iv) the magnetic field formulation. The underlying assumptions and the differences between these models are described in detail. Models (i) to (iii) reduce to the same limit for an axi-symmetric configuration with negligible radial current density, contrary to model (iv). Models (i) to (iii) were retained and implemented in the open source CFD software OpenFOAM. The simulation results were first validated against the analytic solution of an infinite electric rod. Perfect agreement was obtained for all the models tested. The electromagnetic models (i) to (iii) were then coupled with thermal fluid mechanics, and applied to axi-symmetric gas tungsten arc welding test cases with short arc (2, 3 and 5 mm) and truncated conical electrode tip. Models (i) and (ii) lead to the same simulation results, but not model (iii). Model (iii) is suited in the specific limit of long axi-symmetric arc with negligible electrode tip effect, i.e. negligible radial current density. For short axi-symmetric arc with significant electrode tip effect, the more general axi-symmetric formulation of model (ii) should instead be used. (paper)