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Sample records for interlaced microbeam arrays

  1. High-precision radiosurgical dose delivery by interlaced microbeam arrays of high-flux low-energy synchrotron X-rays.

    Directory of Open Access Journals (Sweden)

    Raphaël Serduc

    Full Text Available Microbeam Radiation Therapy (MRT is a preclinical form of radiosurgery dedicated to brain tumor treatment. It uses micrometer-wide synchrotron-generated X-ray beams on the basis of spatial beam fractionation. Due to the radioresistance of normal brain vasculature to MRT, a continuous blood supply can be maintained which would in part explain the surprising tolerance of normal tissues to very high radiation doses (hundreds of Gy. Based on this well described normal tissue sparing effect of microplanar beams, we developed a new irradiation geometry which allows the delivery of a high uniform dose deposition at a given brain target whereas surrounding normal tissues are irradiated by well tolerated parallel microbeams only. Normal rat brains were exposed to 4 focally interlaced arrays of 10 microplanar beams (52 microm wide, spaced 200 microm on-center, 50 to 350 keV in energy range, targeted from 4 different ports, with a peak entrance dose of 200Gy each, to deliver an homogenous dose to a target volume of 7 mm(3 in the caudate nucleus. Magnetic resonance imaging follow-up of rats showed a highly localized increase in blood vessel permeability, starting 1 week after irradiation. Contrast agent diffusion was confined to the target volume and was still observed 1 month after irradiation, along with histopathological changes, including damaged blood vessels. No changes in vessel permeability were detected in the normal brain tissue surrounding the target. The interlacing radiation-induced reduction of spontaneous seizures of epileptic rats illustrated the potential pre-clinical applications of this new irradiation geometry. Finally, Monte Carlo simulations performed on a human-sized head phantom suggested that synchrotron photons can be used for human radiosurgical applications. Our data show that interlaced microbeam irradiation allows a high homogeneous dose deposition in a brain target and leads to a confined tissue necrosis while sparing

  2. Image-guided microbeam irradiation to brain tumour bearing mice using a carbon nanotube x-ray source array

    Science.gov (United States)

    Zhang, Lei; Yuan, Hong; Burk, Laurel M.; Inscoe, Christy R.; Hadsell, Michael J.; Chtcheprov, Pavel; Lee, Yueh Z.; Lu, Jianping; Chang, Sha; Zhou, Otto

    2014-03-01

    Microbeam radiation therapy (MRT) is a promising experimental and preclinical radiotherapy method for cancer treatment. Synchrotron based MRT experiments have shown that spatially fractionated microbeam radiation has the unique capability of preferentially eradicating tumour cells while sparing normal tissue in brain tumour bearing animal models. We recently demonstrated the feasibility of generating orthovoltage microbeam radiation with an adjustable microbeam width using a carbon nanotube based x-ray source array. Here we report the preliminary results from our efforts in developing an image guidance procedure for the targeted delivery of the narrow microbeams to the small tumour region in the mouse brain. Magnetic resonance imaging was used for tumour identification, and on-board x-ray radiography was used for imaging of landmarks without contrast agents. The two images were aligned using 2D rigid body image registration to determine the relative position of the tumour with respect to a landmark. The targeting accuracy and consistency were evaluated by first irradiating a group of mice inoculated with U87 human glioma brain tumours using the present protocol and then determining the locations of the microbeam radiation tracks using γ-H2AX immunofluorescence staining. The histology results showed that among 14 mice irradiated, 11 received the prescribed number of microbeams on the targeted tumour, with an average localization accuracy of 454 µm measured directly from the histology (537 µm if measured from the registered histological images). Two mice received one of the three prescribed microbeams on the tumour site. One mouse was excluded from the analysis due to tissue staining errors.

  3. Interlaced X-ray Microplanar Beams: A Radiosurgery Approach with Clinical Potential

    Energy Technology Data Exchange (ETDEWEB)

    Dilimanian,F.; Zhong, Z.; Bacarian, T.; Benveniste, H.; Romanelli, P.; Wang, R.; Welwart, J.; Yuasa, T.; Rosen, E.; Anschel, D.

    2006-01-01

    Studies have shown that x-rays delivered as arrays of parallel microplanar beams (microbeams), 25- to 90-{micro}m thick and spaced 100-300 {micro}m on-center, respectively, spare normal tissues including the central nervous system (CNS) and preferentially damage tumors. However, such thin microbeams can only be produced by synchrotron sources and have other practical limitations to clinical implementation. To approach this problem, we first studied CNS tolerance to much thicker beams. Three of four rats whose spinal cords were exposed transaxially to four 400-Gy, 0.68-mm microbeams, spaced 4 mm, and all four rats irradiated to their brains with large, 170-Gy arrays of such beams spaced 1.36 mm, all observed for 7 months, showed no paralysis or behavioral changes. We then used an interlacing geometry in which two such arrays at a 90 deg angle produced the equivalent of a contiguous beam in the target volume only. By using this approach, we produced 90-, 120-, and 150-Gy 3.4 x 3.4 x 3.4 mm3 exposures in the rat brain. MRIs performed 6 months later revealed focal damage within the target volume at the 120- and 150-Gy doses but no apparent damage elsewhere at 120 Gy. Monte Carlo calculations indicated a 30-{micro}{micro}m dose falloff (80-20%) at the edge of the target, which is much less than the 2- to 5-mm value for conventional radiotherapy and radiosurgery. These findings strongly suggest potential application of interlaced microbeams to treat tumors or to ablate nontumorous abnormalities with minimal damage to surrounding normal tissue.

  4. Interlaced X-ray Microplanar Beams: A Radiosurgery Approach with Clinical Potential

    International Nuclear Information System (INIS)

    Dilimanian, F.; Zhong, Z.; Bacarian, T.; Benveniste, H.; Romanelli, P.; Wang, R.; Welwart, J.; Yuasa, T.; Rosen, E.; Anschel, D.

    2006-01-01

    Studies have shown that x-rays delivered as arrays of parallel microplanar beams (microbeams), 25- to 90-(micro)m thick and spaced 100-300 (micro)m on-center, respectively, spare normal tissues including the central nervous system (CNS) and preferentially damage tumors. However, such thin microbeams can only be produced by synchrotron sources and have other practical limitations to clinical implementation. To approach this problem, we first studied CNS tolerance to much thicker beams. Three of four rats whose spinal cords were exposed transaxially to four 400-Gy, 0.68-mm microbeams, spaced 4 mm, and all four rats irradiated to their brains with large, 170-Gy arrays of such beams spaced 1.36 mm, all observed for 7 months, showed no paralysis or behavioral changes. We then used an interlacing geometry in which two such arrays at a 90 deg angle produced the equivalent of a contiguous beam in the target volume only. By using this approach, we produced 90-, 120-, and 150-Gy 3.4 x 3.4 x 3.4 mm3 exposures in the rat brain. MRIs performed 6 months later revealed focal damage within the target volume at the 120- and 150-Gy doses but no apparent damage elsewhere at 120 Gy. Monte Carlo calculations indicated a 30-(micro)(micro)m dose falloff (80-20%) at the edge of the target, which is much less than the 2- to 5-mm value for conventional radiotherapy and radiosurgery. These findings strongly suggest potential application of interlaced microbeams to treat tumors or to ablate nontumorous abnormalities with minimal damage to surrounding normal tissue

  5. Wide-range frequency selectivity in an acoustic sensor fabricated using a microbeam array with non-uniform thickness

    International Nuclear Information System (INIS)

    Shintaku, Hirofumi; Kotera, Hidetoshi; Kobayashi, Takayuki; Zusho, Kazuki; Kawano, Satoyuki

    2013-01-01

    In this study, we have demonstrated the fabrication of a microbeam array (MBA) with various thicknesses and investigated the suitability it for an acoustic sensor with wide-range frequency selectivity. For this, an MBA composed of 64 beams, with thicknesses varying from 2.99–142 µm, was fabricated by using single gray-scale lithography and a thick negative photoresist. The vibration of the beams in air was measured using a laser Doppler vibrometer; the resonant frequencies of the beams were measured to be from 11.5 to 290 kHz. Lastly, the frequency range of the MBA with non-uniform thickness was 10.9 times that of the MBA with uniform thickness. (paper)

  6. Counting interlacing pairs on the circle

    NARCIS (Netherlands)

    M. Hazewinkel (Michiel); V.V. Kalashnikov

    1995-01-01

    textabstractLet be the number of interlacing chords joining points on the circle. Let . Then . This formula was conjectured by J. Betramas. The number is also the number of interlacing involutions of points on the real line.

  7. The Amsterdam proton microbeam

    International Nuclear Information System (INIS)

    Bos, A.J.J.

    1984-01-01

    The aim of the work presented in this thesis is to develop a microbeam setup such that small beam spot sizes can be produced routinely, and to investigate the capabilities of the setup for micro-PIXE analysis. The development and performance of the Amsterdam proton microbeam setup are described. The capabilities of the setup for micro-PIXE are shown with an investigation into the presence of trace elements in human hair. (Auth.)

  8. High resolution 3D imaging of synchrotron generated microbeams

    Energy Technology Data Exchange (ETDEWEB)

    Gagliardi, Frank M., E-mail: frank.gagliardi@wbrc.org.au [Alfred Health Radiation Oncology, The Alfred, Melbourne, Victoria 3004, Australia and School of Medical Sciences, RMIT University, Bundoora, Victoria 3083 (Australia); Cornelius, Iwan [Imaging and Medical Beamline, Australian Synchrotron, Clayton, Victoria 3168, Australia and Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2500 (Australia); Blencowe, Anton [Division of Health Sciences, School of Pharmacy and Medical Sciences, The University of South Australia, Adelaide, South Australia 5000, Australia and Division of Information Technology, Engineering and the Environment, Mawson Institute, University of South Australia, Mawson Lakes, South Australia 5095 (Australia); Franich, Rick D. [School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia); Geso, Moshi [School of Medical Sciences, RMIT University, Bundoora, Victoria 3083 (Australia)

    2015-12-15

    Purpose: Microbeam radiation therapy (MRT) techniques are under investigation at synchrotrons worldwide. Favourable outcomes from animal and cell culture studies have proven the efficacy of MRT. The aim of MRT researchers currently is to progress to human clinical trials in the near future. The purpose of this study was to demonstrate the high resolution and 3D imaging of synchrotron generated microbeams in PRESAGE® dosimeters using laser fluorescence confocal microscopy. Methods: Water equivalent PRESAGE® dosimeters were fabricated and irradiated with microbeams on the Imaging and Medical Beamline at the Australian Synchrotron. Microbeam arrays comprised of microbeams 25–50 μm wide with 200 or 400 μm peak-to-peak spacing were delivered as single, cross-fire, multidirectional, and interspersed arrays. Imaging of the dosimeters was performed using a NIKON A1 laser fluorescence confocal microscope. Results: The spatial fractionation of the MRT beams was clearly visible in 2D and up to 9 mm in depth. Individual microbeams were easily resolved with the full width at half maximum of microbeams measured on images with resolutions of as low as 0.09 μm/pixel. Profiles obtained demonstrated the change of the peak-to-valley dose ratio for interspersed MRT microbeam arrays and subtle variations in the sample positioning by the sample stage goniometer were measured. Conclusions: Laser fluorescence confocal microscopy of MRT irradiated PRESAGE® dosimeters has been validated in this study as a high resolution imaging tool for the independent spatial and geometrical verification of MRT beam delivery.

  9. Ion, X-ray, UV and Neutron Microbeam Systems for Cell Irradiation.

    Science.gov (United States)

    Bigelow, A W; Randers-Pehrson, G; Garty, G; Geard, C R; Xu, Y; Harken, A D; Johnson, G W; Brenner, D J

    2010-08-08

    The array of microbeam cell-irradiation systems, available to users at the Radiological Research Accelerator Facility (RARAF), Center for Radiological Research, Columbia University, is expanding. The HVE 5MV Singletron particle accelerator at the facility provides particles to two focused ion microbeam lines: the sub-micron microbeam II and the permanent magnetic microbeam (PMM). Both the electrostatic quadrupole lenses on the microbeam II system and the magnetic quadrupole lenses on the PMM system are arranged as compound lenses consisting of two quadrupole triplets with "Russian" symmetry. Also, the RARAF accelerator is a source for a proton-induced x-ray microbeam (undergoing testing) and is projected to supply protons to a neutron microbeam based on the (7)Li(p, n)(7)Be nuclear reaction (under development). Leveraging from the multiphoton microscope technology integrated within the microbeam II endstation, a UV microspot irradiator - based on multiphoton excitation - is available for facility users. Highlights from radiation-biology demonstrations on single living mammalian cells are included in this review of microbeam systems for cell irradiation at RARAF.

  10. Ion, X-ray, UV and Neutron Microbeam Systems for Cell Irradiation

    Science.gov (United States)

    Bigelow, A.W.; Randers-Pehrson, G.; Garty, G.; Geard, C.R.; Xu, Y.; Harken, A.D.; Johnson, G. W.; Brenner, D.J.

    2012-01-01

    The array of microbeam cell-irradiation systems, available to users at the Radiological Research Accelerator Facility (RARAF), Center for Radiological Research, Columbia University, is expanding. The HVE 5MV Singletron particle accelerator at the facility provides particles to two focused ion microbeam lines: the sub-micron microbeam II and the permanent magnetic microbeam (PMM). Both the electrostatic quadrupole lenses on the microbeam II system and the magnetic quadrupole lenses on the PMM system are arranged as compound lenses consisting of two quadrupole triplets with “Russian” symmetry. Also, the RARAF accelerator is a source for a proton-induced x-ray microbeam (undergoing testing) and is projected to supply protons to a neutron microbeam based on the 7Li(p, n)7Be nuclear reaction (under development). Leveraging from the multiphoton microscope technology integrated within the microbeam II endstation, a UV microspot irradiator – based on multiphoton excitation – is available for facility users. Highlights from radiation-biology demonstrations on single living mammalian cells are included in this review of microbeam systems for cell irradiation at RARAF. PMID:23420504

  11. Interlaced Energy Linac with Smooth Energy Regulation

    CERN Document Server

    Wronka, Sławomir

    2016-01-01

    2 A bstract Radiation is commonly used in many branches of every d ay life. Applications of ionization radiation sources in wide range of energy as well as precise detectors cover a number of areas, from basic research, medical treatment, industrial processing, environmental protection, non - destructive testing to safety a nd security. Accelerator and X - ray tube based techniques are increasingly used in luggage and cargo inspection, smuggling detection of explosives and of nuclear materials. The development of new technologies and new features of “classical” machines can be observed recently with the same, well known physics inside. This report is intended to provide the readers with newly developed at NCBJ experimental stand for cargo screening tests, equipped with linear interlaced - energy accelerator.

  12. An interlacing theorem for reversible Markov chains

    International Nuclear Information System (INIS)

    Grone, Robert; Salamon, Peter; Hoffmann, Karl Heinz

    2008-01-01

    Reversible Markov chains are an indispensable tool in the modeling of a vast class of physical, chemical, biological and statistical problems. Examples include the master equation descriptions of relaxing physical systems, stochastic optimization algorithms such as simulated annealing, chemical dynamics of protein folding and Markov chain Monte Carlo statistical estimation. Very often the large size of the state spaces requires the coarse graining or lumping of microstates into fewer mesoscopic states, and a question of utmost importance for the validity of the physical model is how the eigenvalues of the corresponding stochastic matrix change under this operation. In this paper we prove an interlacing theorem which gives explicit bounds on the eigenvalues of the lumped stochastic matrix. (fast track communication)

  13. MOSFET dosimetry of the radiation therapy microbeams at the European synchrotron radiation facility

    International Nuclear Information System (INIS)

    Rozenfeld, A.; Lerch, M.

    2002-01-01

    Full text: We have developed an innovative on-line MOSFET readout system for use in the quality assurance of radiation treatment beams. Recently the system has found application in areas where excellent spatial resolution is also a requirement in the quality assurance process, for example IMRT, and microbeam radiation therapy. The excellent spatial resolution is achieved by using a quadruple RADFET TM chip in 'edge on' mode. In developing this approach we have found that the system can be utilised to determine any error in the beam profile measurements due to misalignment of RADFET with respect to the radiation beam or microbeam. Using this approach will ensure that the excellent spatial resolution of the RADFET used in 'edge-on' mode is fully utilised. In this work we report on dosimetry measurements performed at the microbeam radiation therapy beamline located at the European Synchrotron Radiation Facility. The synchrotron planar array microbeam with size 10-30 μm and pitch ∼200 μm has found an important application in microbeam radiation therapy (MRT) of brain tumours in infants for whom other kinds of radiotherapy are inadequate and/or unsafe. The radiation damage from an array of parallel microbeams correlates strongly with the range of peak-valley dose ratios (PVDR), ie, the range of the ratio of the absorbed dose to tissue directly in line with the mid-plane of the microbeam to that in the mid-plane between adjacent microbeams. Novel physical dosimetry of the microbeams using the online MOSFET reader system will be presented. Comparison of the experimental results with both GaF film measurements and Monte Carlo computer-simulated dosimetry are described here for selected points in the peak and valley regions of a microbeam-irradiated tissue phantom

  14. 6th International Microbeam Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Dr Kevin M. Prise

    2004-01-01

    The extended abstracts which are submitted here present a summary of the proceedings of the 6th International Workshop/12th LH Gray Workshop: Microbeam Probes of Cellular Radiation Response, held at St. Catherine's College, University of Oxford, UK on March, 29th-31st, 2003. In 1993 the 4th LH Gray Workshop entitled ''Microbeam Probes of Cellular Radiation Response'' was held at the Gray Cancer Institute in Northwood. This was organized by Prof BD Michael, Dr M. Folkard and Dr KM Prise and brought together 40 participants interested in developing and applying new microbeam technology to problems in radiation biology (1). The workshop was an undoubted success and has spawned a series of subsequent workshops every two years. In the past, these workshops have been highly successful in bringing together groups interested in developing and applying micro-irradiation techniques to the study of cell and tissue damage by ionizing radiations. Following the first microbeam workshop, there has been a rapid growth in the number of centres developing radiobiology microbeams, or planning to do so and there are currently 15-20 worldwide. Much of the recent research using microbeams has used them to study low-dose effects and ''non-targeted'' responses such bystander effects, genomic instability and adaptive responses. The goal of the 6th workshop was to build on our knowledge of the development of microbeam approaches and the application to radiation biology in the future with the meeting stretching over a 3 day period. Over 80 participants reviewed the current state of radiobiology microbeam research worldwide and reported on new technological developments both in the fields of physics and biology.

  15. Memory and survival after microbeam radiation therapy

    International Nuclear Information System (INIS)

    Schueltke, Elisabeth; Juurlink, Bernhard H.J.; Ataelmannan, Khalid; Laissue, Jean; Blattmann, Hans; Braeuer-Krisch, Elke; Bravin, Alberto; Minczewska, Joanna; Crosbie, Jeffrey; Taherian, Hadi; Frangou, Evan; Wysokinsky, Tomasz; Chapman, L. Dean; Griebel, Robert; Fourney, Daryl

    2008-01-01

    Background: Disturbances of memory function are frequently observed in patients with malignant brain tumours and as adverse effects after radiotherapy to the brain. Experiments in small animal models of malignant brain tumour using synchrotron-based microbeam radiation therapy (MRT) have shown a promising prolongation of survival times. Materials and methods: Two animal models of malignant brain tumour were used to study survival and memory development after MRT. Thirteen days after implantation of tumour cells, animals were submitted to MRT either with or without adjuvant therapy (buthionine-SR-sulfoximine = BSO or glutamine). We used two orthogonal 1-cm wide arrays of 50 microplanar quasiparallel microbeams of 25 μm width and a center-to-center distance of about 200 μm, created by a multislit collimator, with a skin entrance dose of 350 Gy for each direction. Object recognition tests were performed at day 13 after tumour cell implantation and in monthly intervals up to 1 year after tumour cell implantation. Results: In both animal models, MRT with and without adjuvant therapy significantly increased survival times. BSO had detrimental effects on memory function early after therapy, while administration of glutamine resulted in improved memory

  16. The first interdisciplinary experiments at the IMP high energy microbeam

    Science.gov (United States)

    Du, Guanghua; Guo, Jinlong; Wu, Ruqun; Guo, Na; Liu, Wenjing; Ye, Fei; Sheng, Lina; Li, Qiang; Li, Huiyun

    2015-04-01

    The high energy beam of tens to hundred MeV/u ions possesses mm-to-cm penetration depth in materials and can be easily extracted into air without significant energy loss and beam scattering. Combination of high energy ions and microbeam technology facilitates the microprobe application to many practical studies in large scale samples. The IMP heavy ion microbeam facility has recently been integrated with microscopic positioning and targeting irradiation system. This paper introduced the first interdisciplinary experiments performed at the IMP microbeam facility using the beam of 80.5 MeV/u carbon ions. Bystander effect induction via medium transferring was not found in the micro-irradiation study using HeLa cells. The mouse irradiation experiment demonstrated that carbon irradiation of 10 Gy dose to its tuberomammillary nucleus did not impair the sleep nerve system. The fault injection attack on RSA (Rivest-Shamir-Adleman) decryption proved that the commercial field-programmable gate array chip is vulnerable in single event effect to low linear-energy-transfer carbon irradiation, and the attack can cause the leakage of RSA private key. This work demonstrates the potential of high energy microbeam in its application to biology, biomedical, radiation hardness, and information security studies.

  17. The first interdisciplinary experiments at the IMP high energy microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Du, Guanghua; Guo, Jinlong; Wu, Ruqun; Guo, Na; Liu, Wenjing; Ye, Fei; Sheng, Lina; Li, Qiang [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou (China); Li, Huiyun [Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen (China)

    2015-04-01

    The high energy beam of tens to hundred MeV/u ions possesses mm-to-cm penetration depth in materials and can be easily extracted into air without significant energy loss and beam scattering. Combination of high energy ions and microbeam technology facilitates the microprobe application to many practical studies in large scale samples. The IMP heavy ion microbeam facility has recently been integrated with microscopic positioning and targeting irradiation system. This paper introduced the first interdisciplinary experiments performed at the IMP microbeam facility using the beam of 80.5 MeV/u carbon ions. Bystander effect induction via medium transferring was not found in the micro-irradiation study using HeLa cells. The mouse irradiation experiment demonstrated that carbon irradiation of 10 Gy dose to its tuberomammillary nucleus did not impair the sleep nerve system. The fault injection attack on RSA (Rivest–Shamir–Adleman) decryption proved that the commercial field-programmable gate array chip is vulnerable in single event effect to low linear-energy-transfer carbon irradiation, and the attack can cause the leakage of RSA private key. This work demonstrates the potential of high energy microbeam in its application to biology, biomedical, radiation hardness, and information security studies.

  18. Pool boiling of nanoparticle-modified surface with interlaced wettability

    KAUST Repository

    Hsu, Chin-Chi

    2012-01-01

    This study investigated the pool boiling heat transfer under heating surfaces with various interlaced wettability. Nano-silica particles were used as the coating element to vary the interlaced wettability of the surface. The experimental results revealed that when the wettability of a surface is uniform, the critical heat flux increases with the more wettable surface; however, when the wettability of a surface is modified interlacedly, regardless of whether the modified region becomes more hydrophilic or hydrophobic, the critical heat flux is consistently higher than that of the isotropic surface. In addition, this study observed that critical heat flux was higher when the contact angle difference between the plain surface and the modified region was smaller. © 2012 Hsu et al.

  19. A first generation compact microbeam radiation therapy system based on carbon nanotube X-ray technology

    International Nuclear Information System (INIS)

    Hadsell, M.; Shan, J.; Burk, L.; Zhang, J.; Chang, S.; Laganis, P.; Sprenger, F.; Zhang, L.; Yuan, H.; Lu, J.; Zhou, O.

    2013-01-01

    We have developed a compact microbeam radiation therapy device using carbon nanotube cathodes to create a linear array of narrow focal line segments on a tungsten anode and a custom collimator assembly to select a slice of the resulting wedge-shaped radiation pattern. Effective focal line width was measured to be 131 μm, resulting in a microbeam width of ∼300 μm. The instantaneous dose rate was projected to be 2 Gy/s at full-power. Peak to valley dose ratio was measured to be >17 when a 1.4 mm microbeam separation was employed. Finally, multiple microbeams were delivered to a mouse with beam paths verified through histology

  20. Synchrotron microbeam radiation therapy for rat brain tumor palliation-influence of the microbeam width at constant valley dose

    International Nuclear Information System (INIS)

    Serduc, Raphael; Fonta, Caroline; Renaud, Luc; Bouchet, Audrey; Braeuer-Krisch, Elke; Sarun, Sukhena; Bravin, Alberto; Le Duc, Geraldine; Laissue, Jean A; Spiga, Jenny; Boutonnat, Jean; Siegbahn, Erik Albert; Esteve, Francois

    2009-01-01

    To analyze the effects of the microbeam width (25, 50 and 75 μm) on the survival of 9L gliosarcoma tumor-bearing rats and on toxicity in normal tissues in normal rats after microbeam radiation therapy (MRT), 9L gliosarcomas implanted in rat brains, as well as in normal rat brains, were irradiated in the MRT mode. Three configurations (MRT25, MRT50, MRT75), each using two orthogonally intersecting arrays of either 25, 50 or 75 μm wide microbeams, all spaced 211 μm on center, were tested. For each configuration, peak entrance doses of 860, 480 and 320 Gy, respectively, were calculated to produce an identical valley dose of 18 Gy per individual array at the center of the tumor. Two, 7 and 14 days after radiation treatment, 42 rats were killed to evaluate histopathologically the extent of tumor necrosis, and the presence of proliferating tumors cells and tumor vessels. The median survival times of the normal rats were 4.5, 68 and 48 days for MRT25, 50 and 75, respectively. The combination of the highest entrance doses (860 Gy per array) with 25 μm wide beams (MRT25) resulted in a cumulative valley dose of 36 Gy and was excessively toxic, as it led to early death of all normal rats and of ∼50% of tumor-bearing rats. The short survival times, particularly of rats in the MRT25 group, restricted adequate observance of the therapeutic effect of the method on tumor-bearing rats. However, microbeams of 50 μm width led to the best median survival time after 9L gliosarcoma MRT treatment and appeared as the better compromise between tumor control and normal brain toxicity compared with 75 μm or 25 μm widths when used with a 211 μm on-center distance. Despite very high radiation doses, the tumors were not sterilized; viable proliferating tumor cells remained present at the tumor margin. This study shows that microbeam width and peak entrance doses strongly influence tumor responses and normal brain toxicity, even if valley doses are kept constant in all groups. The use

  1. Interlacing of zeros of quasi-orthogonal meixner polynomials | Driver ...

    African Journals Online (AJOL)

    ... interlacing of zeros of quasi-orthogonal Meixner polynomials Mn(x;β; c) with the zeros of their nearest orthogonal counterparts Mt(x;β + k; c), l; n ∈ ℕ, k ∈ {1; 2}; is also discussed. Mathematics Subject Classication (2010): 33C45, 42C05. Key words: Discrete orthogonal polynomials, quasi-orthogonal polynomials, Meixner

  2. Method and devices for performing stereotactic microbeam radiation therapy

    Science.gov (United States)

    Dilmanian, F. Avraham

    2010-01-05

    A radiation delivery system generally includes either a synchrotron source or a support frame and a plurality of microbeam delivery devices supported on the support frame, both to deliver a beam in a hemispherical arrangement. Each of the microbeam delivery devices or synchrotron irradiation ports is adapted to deliver at least one microbeam of radiation along a microbeam delivery axis, wherein the microbeam delivery axes of the plurality of microbeam delivery devices cross within a common target volume.

  3. A preclinical microbeam facility with a conventional x-ray tube.

    Science.gov (United States)

    Bartzsch, Stefan; Cummings, Craig; Eismann, Stephan; Oelfke, Uwe

    2016-12-01

    Microbeam radiation therapy is an innovative treatment approach in radiation therapy that uses arrays of a few tens of micrometer wide and a few hundreds of micrometer spaced planar x-ray beams as treatment fields. In preclinical studies these fields efficiently eradicated tumors while normal tissue could effectively be spared. However, development and clinical application of microbeam radiation therapy is impeded by a lack of suitable small scale sources. Until now, only large synchrotrons provide appropriate beam properties for the production of microbeams. In this work, a conventional x-ray tube with a small focal spot and a specially designed collimator are used to produce microbeams for preclinical research. The applicability of the developed source is demonstrated in a pilot in vitro experiment. The properties of the produced radiation field are characterized by radiochromic film dosimetry. 50 μm wide and 400 μm spaced microbeams were produced in a 20 × 20 mm 2 sized microbeam field. The peak to valley dose ratio ranged from 15.5 to 30, which is comparable to values obtained at synchrotrons. A dose rate of up to 300 mGy/s was achieved in the microbeam peaks. Analysis of DNA double strand repair and cell cycle distribution after in vitro exposures of pancreatic cancer cells (Panc1) at the x-ray tube and the European Synchrotron leads to similar results. In particular, a reduced G2 cell cycle arrest is observed in cells in the microbeam peak region. At its current stage, the source is restricted to in vitro applications. However, moderate modifications of the setup may soon allow in vivo research in mice and rats.

  4. Monte Carlo dose calculation of microbeam in a lung phantom

    International Nuclear Information System (INIS)

    Company, F.Z.; Mino, C.; Mino, F.

    1998-01-01

    Full text: Recent advances in synchrotron generated X-ray beams with high fluence rate permit investigation of the application of an array of closely spaced, parallel or converging microplanar beams in radiotherapy. The proposed techniques takes advantage of the hypothesised repair mechanism of capillary cells between alternate microbeam zones, which regenerates the lethally irradiated endothelial cells. The lateral and depth doses of 100 keV microplanar beams are investigated for different beam dimensions and spacings in a tissue, lung and tissue/lung/tissue phantom. The EGS4 Monte Carlo code is used to calculate dose profiles at different depth and bundles of beams (up to 20x20cm square cross section). The maximum dose on the beam axis (peak) and the minimum interbeam dose (valley) are compared at different depths, bundles, heights, widths and beam spacings. Relatively high peak to valley ratios are observed in the lung region, suggesting an ideal environment for microbeam radiotherapy. For a single field, the ratio at the tissue/lung interface will set the maximum dose to the target volume. However, in clinical application, several fields would be involved allowing much greater doses to be applied for the elimination of cancer cells. We conclude therefore that multifield microbeam therapy has the potential to achieve useful therapeutic ratios for the treatment of lung cancer

  5. Active mems microbeam device for gas detection

    KAUST Repository

    Bouchaala, Adam M.

    2017-10-05

    Sensors and active switches for applications in gas detection and other fields are described. The devices are based on the softening and hardening nonlinear response behaviors of microelectromechanical systems (MEMS) clamped-clamped microbeams. In that context, embodiments of gas-triggered MEMS microbeam sensors and switches are described. The microbeam devices can be coated with a Metal-Organic Framework to achieve high sensitivity. For gas sensing, an amplitude-based tracking algorithm can be used to quantify an amount of gas captured by the devices according to frequency shift. Noise analysis is also conducted according to the embodiments, which shows that the microbeam devices have high stability against thermal noise. The microbeam devices are also suitable for the generation of binary sensing information for alarming, for example.

  6. A history of laser scissors (microbeams).

    Science.gov (United States)

    Berns, Michael W

    2007-01-01

    This introductory chapter reviews the history of microbeams starting with the original UV microbeam work of Tchakhotine in 1912 and covers the progress and application of microbeams through 2006. The main focus of the chapter is on laser "scissors" starting with Marcel Bessis' and colleagues work with the ruby laser microbeam in Paris in 1962. Following this introduction, a section is devoted to describing the different laser microbeam systems and then the rest of the chapter is devoted to applications in cell and developmental biology. The approach is to focus on the organelle/structure and describe how the laser microbeam has been applied to studying its structure and/or function. Since considerable work has been done on chromosomes and the mitotic spindle (Section V.A and C), these topics have been divided in distinct subsections. Other topics discussed are injection of foreign DNA through the cell membrane (optoporation/optoinjection), cell migration, the nucleolus, mitochondria, cytoplasmic filaments, and embryos fate-mapping. A final technology section is devoted to discussing the pros and cons of building/buying your own laser microbeam system and the option of using the Internet-based RoboLase system. Throughout the chapter, reference is made to other chapters in the book that go into more detail on the subjects briefly mentioned.

  7. Signal adaptive processing in MPEG-2 decoders with embedded resizing for interlaced video

    Science.gov (United States)

    Zhong, Zhun; Chen, Yingwei; Lan, Tse-Hua

    2002-01-01

    Video decoding at reduced resolution with resizing embedded in the decoding loop saves computational resources such as memory, memory bandwidth and CPU cycles. Key to such embedded resizing is proper filtering/scaling of DCT data, and motion compensation at the reduced resolution. Although MPEG-2 video decoding with embedded resizing has been investigated in the past, little work has been reported on solving problems associated with interlaced video undergoing decoding with embedded resizing. In particular, annoying artifacts may occur in moving areas of interlaced video due to improper scaling or motion compensation. In this paper, we introduce the notion of the Local Interlacing Property for interlaced moving areas and propose algorithms to detect and process data with the Local Interlacing Property properly in the context of decoding with embedded resizing. Specifically, we demonstrate that 1) vertical high frequency in interlaced moving areas should be preserved during downscaling, and 2) phase shift must be added for motion compensation in interlaced moving areas under certain circumstances. Experimental results show that our method effectively removes artifacts in interlaced moving areas, making MPEG-2 video decoding with embedded resizing a practical tradeoff for interlaced video.

  8. The integration problem: Interlacing language, action and perception

    DEFF Research Database (Denmark)

    Cowley, Stephen

    2014-01-01

    the integration problem. Using a case study, the paper shows how a young man uses external resources in an experimental task. He grasps a well-defined problem by using material resources, talking about his doings and switching roles and procedures. Attentional skills enable him to act as an air cadet who, among...... other things, connects action, leadership and logic. Air- force practices prompt him to draw timeously on non-local resources as, using impersonal experience, he interlaces language, action and perception. He connects the cultural and the metabolic in cognitive work as he finds a way to completion...

  9. Interlaced strands: Health psychology in Brazil from an autobiographic perspective.

    Science.gov (United States)

    Spink, Mary Jane P

    2018-03-01

    The presence of psychology in Brazilian Health Settings is closely related to two socio-political movements: for the creation of the Brazilian Unified Health System in 1990 and for Psychiatric Reform. Each had a multidisciplinary stance closely associated with a socially committed approach to healthcare delivery and connected with prior experiences that influenced its policies, among them the National AIDS Programme. These developments are told as a tale that interlaced autobiographical data and the long road to a universal healthcare system that shaped the relationship between psychology and health in the country.

  10. The new Sandia light ion microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Vizkelethy, G., E-mail: gvizkel@sandia.gov [Sandia National Laboratories, P.O. Box 5800, MS 1056, Albuquerque, NM 87185 (United States); Doyle, B.L. [Sandia National Laboratories, P.O. Box 5800, MS 1056, Albuquerque, NM 87185 (United States); McDaniel, F.L. [Sandia National Laboratories, P.O. Box 5800, MS 1056, Albuquerque, NM 87185 (United States); University of North Texas, Denton, TX 76203 (United States)

    2012-02-15

    The Ion Beam Laboratory of Sandia National Laboratories (SNL) was recently relocated into a brand new building. The 6 MV High Voltage Engineering (HVE) tandem accelerator (hosting the heavy ion microbeam and several analytical beam lines) and the 350 kV HVE implanter with a nanobeam were moved to the new building. There were several new pieces of equipment acquired associated with the move, among them a new high brightness 3 MV Pelletron accelerator, a high resolution light ion microbeam, a nanoimplanter, and a transmission electron microscope (TEM) connected to the tandem accelerator. In this paper this new facility will be described, and initial results of the new microbeam will be presented.

  11. A horizontal multi-purpose microbeam system

    Science.gov (United States)

    Xu, Y.; Randers-Pehrson, G.; Marino, S. A.; Garty, G.; Harken, A.; Brenner, D. J.

    2018-04-01

    A horizontal multi-purpose microbeam system with a single electrostatic quadruplet focusing lens has been developed at the Columbia University Radiological Research Accelerator Facility (RARAF). It is coupled with the RARAF 5.5 MV Singleton accelerator (High Voltage Engineering Europa, the Netherlands) and provides micrometer-size beam for single cell irradiation experiments. It is also used as the primary beam for a neutron microbeam and microPIXE (particle induced x-ray emission) experiment because of its high particle fluence. The optimization of this microbeam has been investigated with ray tracing simulations and the beam spot size has been verified by different measurements.

  12. A Horizontal Multi-Purpose Microbeam System.

    Science.gov (United States)

    Xu, Y; Randers-Pehrson, G; Marino, S A; Garty, G; Harken, A; Brenner, D J

    2018-04-21

    A horizontal multi-purpose microbeam system with a single electrostatic quadruplet focusing lens has been developed at the Columbia University Radiological Research Accelerator Facility (RARAF). It is coupled with the RARAF 5.5 MV Singleton accelerator (High Voltage Engineering Europa, the Netherlands) and provides micrometer-size beam for single cell irradiation experiments. It is also used as the primary beam for a neutron microbeam and microPIXE (particle induced x-ray emission) experiment because of its high particle fluence. The optimization of this microbeam has been investigated with ray tracing simulations and the beam spot size has been verified by different measurements.

  13. Potensi Limbah Padat sebagai Benang Gintir Berbasis Sistem Interlacing

    Directory of Open Access Journals (Sweden)

    Nisa Fardani

    2015-09-01

    Full Text Available Sistem pengelolaan sampah di tempat pembuangan sampah menjadi masalah lingkungan yang besar seiring dengan pertumbuhan industri pulp dan kertas di Indonesia. Konversi limbah padat menjadi bahan bakar pelengkap untuk industri kertas juga tidak memberikan hasil yang signifikan untuk memecahkan masalah pencemaran udara pada saat karbon aktif dibebaskan dari proses pembakaran. Masalah ini secara khusus menuntut sistem pengelolaan sampah yang maju dan efektif secara terus-menerus. Baru-baru ini, optimasi pemanfaatan serat-limbah menjadi alternatif khusus untuk mengurangi tumpukan sampah di tempat pembuangan sampah. Namun, tidak semua dapat didaur ulang. Karakteristik limbah padat berserat dari industri kertas tisu cenderung menurun gramaturnya, sehingga sangat disayangkan pemanfaatannya akan berkurang bahkan setelah proses daur ulang. Di sisi lain, struktur kimianya yang telah rusak selama proses produksi tampaknya menjadi semangat baru bagi industri tekstil di masa depan dalam mengembangkan teknologi daur ulang limbah padat berserat, yang menghasilkan benang tekstil generasi baru. Fokus dalam penelitian ini ditekankan pada penemuan tas yang terbuat dari bahan serat-limbah menggunakan metode eksperimental. Identifikasi karakteristik serat-sampah berbasis padat dikembangkan melalui teknik eksplorasi multi-ply yarns berdasarkan sistem interlace. Hubungan antara penciptaan produk dan forecasting  tren pada tahun 2013 akan menjadi analisis berikutnya sebagai salah satu cara untuk memecahkan masalah sampah.Kata Kunci: limbah; multi-ply yarns; sistem interlacing.The Potential of Solid Waste as Multiply Yarn Based on Interlacing SystemsSolid-waste disposal in landfills is becoming a massive environmental problem as a result of the growth of the pulp and paper industry in Indonesia. The conversion of solid waste to complementary fuel for the paper industry is also not giving any significant results to solve air contamination, as active carbon is released

  14. Comparison of two methods for measuring γ-H2AX nuclear fluorescence as a marker of DNA damage in cultured human cells: applications for microbeam radiation therapy

    Science.gov (United States)

    Anderson, D.; Andrais, B.; Mirzayans, R.; Siegbahn, E. A.; Fallone, B. G.; Warkentin, B.

    2013-06-01

    Microbeam radiation therapy (MRT) delivers single fractions of very high doses of synchrotron x-rays using arrays of microbeams. In animal experiments, MRT has achieved higher tumour control and less normal tissue toxicity compared to single-fraction broad beam irradiations of much lower dose. The mechanism behind the normal tissue sparing of MRT has yet to be fully explained. An accurate method for evaluating DNA damage, such as the γ-H2AX immunofluorescence assay, will be important for understanding the role of cellular communication in the radiobiological response of normal and cancerous cell types to MRT. We compare two methods of quantifying γ-H2AX nuclear fluorescence for uniformly irradiated cell cultures: manual counting of γ-H2AX foci by eye, and an automated, MATLAB-based fluorescence intensity measurement. We also demonstrate the automated analysis of cell cultures irradiated with an array of microbeams. In addition to offering a relatively high dynamic range of γ-H2AX signal versus irradiation dose ( > 10 Gy), our automated method provides speed, robustness, and objectivity when examining a series of images. Our in-house analysis facilitates the automated extraction of the spatial distribution of the γ-H2AX intensity with respect to the microbeam array — for example, the intensities in the peak (high dose area) and valley (area between two microbeams) regions. The automated analysis is particularly beneficial when processing a large number of samples, as is needed to systematically study the relationship between the numerous dosimetric and geometric parameters involved with MRT (e.g., microbeam width, microbeam spacing, microbeam array dimensions, peak dose, valley dose, and geometric arrangement of multiple arrays) and the resulting DNA damage.

  15. A point kernel algorithm for microbeam radiation therapy

    Science.gov (United States)

    Debus, Charlotte; Oelfke, Uwe; Bartzsch, Stefan

    2017-11-01

    Microbeam radiation therapy (MRT) is a treatment approach in radiation therapy where the treatment field is spatially fractionated into arrays of a few tens of micrometre wide planar beams of unusually high peak doses separated by low dose regions of several hundred micrometre width. In preclinical studies, this treatment approach has proven to spare normal tissue more effectively than conventional radiation therapy, while being equally efficient in tumour control. So far dose calculations in MRT, a prerequisite for future clinical applications are based on Monte Carlo simulations. However, they are computationally expensive, since scoring volumes have to be small. In this article a kernel based dose calculation algorithm is presented that splits the calculation into photon and electron mediated energy transport, and performs the calculation of peak and valley doses in typical MRT treatment fields within a few minutes. Kernels are analytically calculated depending on the energy spectrum and material composition. In various homogeneous materials peak, valley doses and microbeam profiles are calculated and compared to Monte Carlo simulations. For a microbeam exposure of an anthropomorphic head phantom calculated dose values are compared to measurements and Monte Carlo calculations. Except for regions close to material interfaces calculated peak dose values match Monte Carlo results within 4% and valley dose values within 8% deviation. No significant differences are observed between profiles calculated by the kernel algorithm and Monte Carlo simulations. Measurements in the head phantom agree within 4% in the peak and within 10% in the valley region. The presented algorithm is attached to the treatment planning platform VIRTUOS. It was and is used for dose calculations in preclinical and pet-clinical trials at the biomedical beamline ID17 of the European synchrotron radiation facility in Grenoble, France.

  16. Origin of Knudsen forces on heated microbeams

    KAUST Repository

    Zhu, Taishan

    2010-09-09

    The presented work probes the fundamentals of Knudsen forces. Using the direct simulation Monte Carlo (DSMC) method, the flows induced by temperature inhomogeneity within a representative configuration and the Knudsen force acting on a heated microbeam are captured as functions of Knudsen number in the entire flow regime. Both flow strength and Knudsen force peak in the transition regime and negative Knudsen force absent in experimental data is observed. The mechanisms of the thermally induced flows and Knudsen forces are studied. It has been found that thermal edge flow is the main driven source for the formation of the Knudsen force on microbeams and domain configuration plays an important role in the process.

  17. Video Multiple Watermarking Technique Based on Image Interlacing Using DWT

    Directory of Open Access Journals (Sweden)

    Mohamed M. Ibrahim

    2014-01-01

    Full Text Available Digital watermarking is one of the important techniques to secure digital media files in the domains of data authentication and copyright protection. In the nonblind watermarking systems, the need of the original host file in the watermark recovery operation makes an overhead over the system resources, doubles memory capacity, and doubles communications bandwidth. In this paper, a robust video multiple watermarking technique is proposed to solve this problem. This technique is based on image interlacing. In this technique, three-level discrete wavelet transform (DWT is used as a watermark embedding/extracting domain, Arnold transform is used as a watermark encryption/decryption method, and different types of media (gray image, color image, and video are used as watermarks. The robustness of this technique is tested by applying different types of attacks such as: geometric, noising, format-compression, and image-processing attacks. The simulation results show the effectiveness and good performance of the proposed technique in saving system resources, memory capacity, and communications bandwidth.

  18. Interlaced CNT Electrodes for Bacterial Fouling Reduction of Microfiltration Membranes.

    Science.gov (United States)

    Zhang, Qiaoying; Arribas, Paula; Remillard, E Marielle; García-Payo, M Carmen; Khayet, Mohamed; Vecitis, Chad D

    2017-08-15

    Interlaced carbon nanotube electrodes (ICE) were prepared by vacuum filtering a well-dispersed carbon nanotube-Nafion solution through a laser-cut acrylic stencil onto a commercial polyvinylidene fluoride (PVDF) microfiltration (MF) membrane. Dead-end filtration was carried out using 10 7 and 10 8 CFU mL -1 Pseudomonas fluorescens to study the effects of the electrochemically active ICE on bacterial density and morphology, as well as to evaluate the bacterial fouling trend and backwash (BW) efficacy, respectively. Finally, a simplified COMSOL model of the ICE electric field was used to help elucidate the antifouling mechanism in solution. At 2 V DC and AC (total cell potential), the average bacterial log removal of the ICE-PVDF increased by ∼1 log compared to the control PVDF (3.5-4 log). Bacterial surface density was affected by the presence and polarity of DC electric potential, being 87-90% lower on the ICE cathode and 59-93% lower on the ICE anode than that on the PVDF after filtration, and BW further reduced the density on the cathode significantly. The optimal operating conditions (2 V AC) reduced the fouling rate by 75% versus the control and achieved up to 96% fouling resistance recovery (FRR) during BW at 8 V AC using 155 mM NaCl. The antifouling performance should mainly be due to electrokinetic effects, and the electric field simulation by COMSOL model suggested electrophoresis and dielectrophoresis as likely mechanisms.

  19. Fabrication of fine imaging devices using an external proton microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, T., E-mail: sakai.takuro@jaea.go.jp [Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Yasuda, R.; Iikura, H.; Nojima, T. [Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Koka, M.; Satoh, T.; Ishii, Y. [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency (JAEA), Takasaki, Gunma 370-1292 (Japan); Oshima, A. [Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047 (Japan)

    2014-08-01

    We have successfully fabricated novel microscopic imaging devices made from UV/EB curable resin using an external scanning proton microbeam. The devices are micro-structured fluorescent plates that consist of an array of micro-pillars that align periodically. The base material used in the pillars is UV/EB curable resin and each pillar contains phosphor grains. The pattern exposures were performed using a proton beam writing technique. The height of the pillars depends on the range of the proton beam. Optical microscopy and scanning electron microscopy have been used to characterize the samples. The results show that the fabricated fluorescent plates are expected to be compatible with both spatial resolution and detection efficiency.

  20. All-Metal Dual-Polarized W-band Patch Element for Phased Array Antenna Applications

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this work is to design and demonstrate an interlaced patch array aperture for transmission and reception of dual-polarized radar signals at 94 GHz...

  1. Motion-JPEG2000 codec compensated for interlaced scanning videos.

    Science.gov (United States)

    Ishida, Takuma; Muramatsu, Shogo; Kikuchi, Hisakazu

    2005-12-01

    This paper presents an implementation scheme of Motion-JPEG2000 (MJP2) integrated with invertible deinterlacing. In previous work, we developed an invertible deinterlacing technique that suppresses the comb-tooth artifacts which are caused by field interleaving for interlaced scanning videos, and affect the quality of scalable frame-based codecs, such as MJP2. Our technique has two features, where sampling density is preserved and image quality is recovered by an inverse process. When no codec is placed between the deinterlacer and inverse process, the original video is perfectly reconstructed. Otherwise, it is almost completely recovered. We suggest an application scenario of this invertible deinterlacer for enhancing the sophisticated signal-to-noise ratio scalability in the frame-based MJP2 coding. The proposed system suppresses the comb-tooth artifacts at low bitrates, while enabling the quality recovery through its inverse process at high bitrates within the standard bitstream format. The main purpose of this paper is to present a system that yields high quality recovery for an MJP2 codec. We demonstrate that our invertible deinterlacer can be embedded into the discrete.wavelet transform employed in MJP2. As a result, the energy gain factor to control rate-distortion characteristics can be compensated for optimal compression. Simulation results show that the recovery of quality is improved by, for example, more than 2.0 dB in peak signal-to-noise ratio by applying our proposed gain compensation when decoding 8-bit grayscale Football sequence at 2.0 bpp.

  2. Computational modelling of the cerebral cortical microvasculature: effect of x-ray microbeams versus broad beam irradiation

    Science.gov (United States)

    Merrem, A.; Bartzsch, S.; Laissue, J.; Oelfke, U.

    2017-05-01

    Microbeam Radiation Therapy is an innovative pre-clinical strategy which uses arrays of parallel, tens of micrometres wide kilo-voltage photon beams to treat tumours. These x-ray beams are typically generated on a synchrotron source. It was shown that these beam geometries allow exceptional normal tissue sparing from radiation damage while still being effective in tumour ablation. A final biological explanation for this enhanced therapeutic ratio has still not been found, some experimental data support an important role of the vasculature. In this work, the effect of microbeams on a normal microvascular network of the cerebral cortex was assessed in computer simulations and compared to the effect of homogeneous, seamless exposures at equal energy absorption. The anatomy of a cerebral microvascular network and the inflicted radiation damage were simulated to closely mimic experimental data using a novel probabilistic model of radiation damage to blood vessels. It was found that the spatial dose fractionation by microbeam arrays significantly decreased the vascular damage. The higher the peak-to-valley dose ratio, the more pronounced the sparing effect. Simulations of the radiation damage as a function of morphological parameters of the vascular network demonstrated that the distribution of blood vessel radii is a key parameter determining both the overall radiation damage of the vasculature and the dose-dependent differential effect of microbeam irradiation.

  3. High energy ion hit technique to local area using microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Ryuichi; Kamiya, Tomihiro; Suda, Tamotsu; Sakai, Takuro; Hirao, Toshio; Kobayashi, Yasuhiko; Watanabe, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    Single energetic ion hit technique has been developed as an application of ion microbeam technique, in order to study the effect of local damage or injury to materials and living organisms. The overall performance is basically defined by those of separate techniques: microbeam formation, microbeam positioning, single ion detection, detection signal processing, hit timing control, and hit verification. Recent progress on the developments of these techniques at JAERI-TIARA facility are reviewed. (author)

  4. Electrothermally Actuated Microbeams With Varying Stiffness

    KAUST Repository

    Tella, Sherif Adekunle

    2017-11-03

    We present axially loaded clamped-guided microbeams that can be used as resonators and actuators of variable stiffness, actuation, and anchor conditions. The applied axial load is implemented by U-shaped electrothermal actuators stacked at one of the beams edges. These can be configured and wired in various ways, which serve as mechanical stiffness elements that control the operating resonance frequency of the structures and their static displacement. The experimental results have shown considerable increase in the resonance frequency and mid-point deflection of the microbeam upon changing the end conditions of the beam. These results can be promising for applications requiring large deflection and high frequency tunability, such as filters, memory devices, and switches. The experimental results are compared to multi-physics finite-element simulations showing good agreement among them.

  5. Scatter factors assessment in microbeam radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Prezado, Y.; Martinez-Rovira, I.; Sanchez, M. [Laboratoire Imagerie et Modelisation en Neurobiologie et Cancerologie IMNC-UMR 8165, Centre National de la Recherche Scientifique (CNRS), Campus Universitaire, Bat. 440, 15 rue Georges Clemenceau, 91406 Orsay Cedex (France); Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, E-08028 Barcelona (Spain) and ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), 6 Rue Jules Horowitz, B.P. 220, 38043 Grenoble Cedex (France); Servicio de Radiofisica, Complejo Hospitalario de Santiago de Compostela, Rua Choupana S/N, 15706 Santiago de Compostela (Spain)

    2012-03-15

    Purpose: The success of the preclinical studies in Microbeam Radiation Therapy (MRT) paved the way to the clinical trials under preparation at the Biomedical Beamline of the European Synchrotron Radiation Facility. Within this framework, an accurate determination of the deposited dose is crucial. With that aim, the scatter factors, which translate the absolute dose measured in reference conditions (2 x 2 cm{sup 2} field size at 2 cm-depth in water) to peak doses, were assessed. Methods: Monte Carlo (MC) simulations were performed with two different widely used codes, PENELOPE and GEANT4, for the sake of safety. The scatter factors were obtained as the ratio of the doses that are deposited by a microbeam and by a field of reference size, at the reference depth. The calculated values were compared with the experimental data obtained by radiochromic (ISP HD-810) films and a PTW 34070 large area chamber. Results: The scatter factors for different microbeam field sizes assessed by the two MC codes were in agreement and reproduced the experimental data within uncertainty bars. Those correction factors were shown to be non-negligible for the future MRT clinical settings: an average 30% lower dose was deposited by a 50 {mu}m microbeam with respect to the reference conditions. Conclusions: For the first time, the scatter factors in MRT were systematically studied. They constitute an essential key to deposit accurate doses in the forthcoming clinical trials in MRT. The good agreement between the different calculations and the experimental data confirms the reliability of this challenging micrometric dose estimation.

  6. Optofluidic cell manipulation for a biological microbeam

    Science.gov (United States)

    Grad, Michael; Bigelow, Alan W.; Garty, Guy; Attinger, Daniel; Brenner, David J.

    2013-01-01

    This paper describes the fabrication and integration of light-induced dielectrophoresis for cellular manipulation in biological microbeams. An optoelectronic tweezers (OET) cellular manipulation platform was designed, fabricated, and tested at Columbia University's Radiological Research Accelerator Facility (RARAF). The platform involves a light induced dielectrophoretic surface and a microfluidic chamber with channels for easy input and output of cells. The electrical conductivity of the particle-laden medium was optimized to maximize the dielectrophoretic force. To experimentally validate the operation of the OET device, we demonstrate UV-microspot irradiation of cells containing green fluorescent protein (GFP) tagged DNA single-strand break repair protein, targeted in suspension. We demonstrate the optofluidic control of single cells and groups of cells before, during, and after irradiation. The integration of optofluidic cellular manipulation into a biological microbeam enhances the facility's ability to handle non-adherent cells such as lymphocytes. To the best of our knowledge, this is the first time that OET cell handling is successfully implemented in a biological microbeam.

  7. Efficient Implementation of Volterra Filters for De-interlacing TV Images - Snell and Wilcox

    DEFF Research Database (Denmark)

    Budd, Chris; Gravesen, Jens; Willson, Eddie

    1998-01-01

    A standard TV image is transmitted as a series of horizontal lines. To reduce band-width effects in transmission, half of a picture is transmitted in each frame, i.e., information is only given about pictures on alternate lines, a process called interlacing. A difficulty with this process...... is that other images (for example computer images) do not have alternate lines omitted. Thus it is desirable to be able to interpolate an existing TV images to obtain information on the images between alternate lines; this is the de-interlacing process....

  8. Proton microbeam irradiation effects on PtBA polymer

    Indian Academy of Sciences (India)

    Microbeam irradiation effects on poly-tert-butyl-acrylate (PtBA) polymer using 2.0 MeV proton microbeam are reported. Preliminary results on pattern formation on PtBA are carried out as a function of fluence. After writing the pattern, a thin layer of Ge is deposited. Distribution of Ge in pristine and ion beam patterned surface ...

  9. Heavy-ion microbeam system at JAEA-Takasaki for microbeam biology

    International Nuclear Information System (INIS)

    Funayama, Tomoo; Wada, Seiichi; Yokota, Yuichiro

    2008-01-01

    Research concerning cellular responses to low dose irradiation, radiation-induced bystander effects, and the biological track structure of charged particles has recently received particular attention in the field of radiation biology. Target irradiation employing a microbeam represents a useful means of advancing this research by obviating some of the disadvantages associated with the conventional irradiation strategies. The heavy-ion microbeam system at Japan Atomic Energy Agency (JAEA)-Takasaki, which was planned in 1987 and started in the early 1990's, can provide target irradiation of heavy charged particles to biological material at atmospheric pressure using a minimum beam size 5 μm in diameter. A variety of biological material has been irradiated using this microbeam system including cultured mammalian and higher plant cells, isolated fibers of mouse skeletal muscle, silkworm (Bombyx mori) embryos and larvae, Arabidopsis thaliana roots, and the nematode Caenorhabditis elegans. The system can be applied to the investigation of mechanisms within biological organisms not only in the context of radiation biology, but also in the fields of general biology such as physiology, developmental biology and neurobiology, and should help to establish and contribute to the field of 'microbeam biology'. (author)

  10. Dynamics of Microbeams under Multi-Frequency Excitations

    KAUST Repository

    Ibrahim, Alwathiqbellah

    2017-01-24

    This paper presents an investigation of the dynamics of microbeams under multiple harmonic electrostatic excitation frequencies. First, the response of a cantilever microbeam to two alternating current (AC) source excitation is examined. We show by simulations the response of the microbeam at primary resonance (near the fundamental natural frequency) and at secondary resonances (near half, superharmonic, and twice, subharmonic, the fundamental natural frequency). A multimode Galerkin method combined with the Euler-Bernoulli beam equation, accounting for the nonlinear electrostatic force, has been used to develop a reduced order model. The response of the cantilever microbeam to three AC source excitation is also investigated and shown as a promising technique to enhance the bandwidth of resonators. Finally, an experimental study of a clamped-clamped microbeam is conducted, demonstrating the multi-frequency excitation resonances using two, three, and four AC sources.

  11. Dynamics of Microbeams under Multi-Frequency Excitations

    Directory of Open Access Journals (Sweden)

    Alwathiqbellah Ibrahim

    2017-01-01

    Full Text Available This paper presents an investigation of the dynamics of microbeams under multiple harmonic electrostatic excitation frequencies. First, the response of a cantilever microbeam to two alternating current (AC source excitation is examined. We show by simulations the response of the microbeam at primary resonance (near the fundamental natural frequency and at secondary resonances (near half, superharmonic, and twice, subharmonic, the fundamental natural frequency. A multimode Galerkin method combined with the Euler-Bernoulli beam equation, accounting for the nonlinear electrostatic force, has been used to develop a reduced order model. The response of the cantilever microbeam to three AC source excitation is also investigated and shown as a promising technique to enhance the bandwidth of resonators. Finally, an experimental study of a clamped-clamped microbeam is conducted, demonstrating the multi-frequency excitation resonances using two, three, and four AC sources.

  12. Analysis of the X-ray microbeam test result of the flash memories

    International Nuclear Information System (INIS)

    Yan Yihua; Ding Lili; Chen Wei; Guo Hongxia; Guo Xiaoqiang; Lin Dongsheng; Zhang Keying; Zhang Fengqi; Deng Yuliang; Fan Ruyu

    2013-01-01

    Background: The failure phenomenon is difficult to analyze for the flash memories when the whole chip is exposed to irradiation since both the memory array and the peripheral circuits might be degraded. Purpose: In order to detect the radiation susceptibility and corresponding phenomenon of the related circuits that included in the flash memories, the X-ray microbeam is used as the radiation source instead of 60 Co. Methods: The failure phenomenon is studied respectively when the memory array, decoder circuits, the charge pump circuits as well as the I/O circuits are exposed to radiation. The errors are mapped according to the logical address and the failure mechanism is analyzed based on the circuits. Results: Irradiated on the memory .array win lead to regularly distributed 0→1 bit flips, while only 1→0 are found when the row decoder is under exposure. Degradation of the charge pump circuits would lead to the erase/program functional failure. Conclusions: The results suggest that the X-ray microbeam radiation test is a good method for detecting the radiation susceptibility of the integrated circuits that contains lots of circuit modules. (authors)

  13. Genome-wide transcription responses to synchrotron microbeam radiotherapy.

    Science.gov (United States)

    Sprung, Carl N; Yang, Yuqing; Forrester, Helen B; Li, Jason; Zaitseva, Marina; Cann, Leonie; Restall, Tina; Anderson, Robin L; Crosbie, Jeffrey C; Rogers, Peter A W

    2012-10-01

    The majority of cancer patients achieve benefit from radiotherapy. A significant limitation of radiotherapy is its relatively low therapeutic index, defined as the maximum radiation dose that causes acceptable normal tissue damage to the minimum dose required to achieve tumor control. Recently, a new radiotherapy modality using synchrotron-generated X-ray microbeam radiotherapy has been demonstrated in animal models to ablate tumors with concurrent sparing of normal tissue. Very little work has been undertaken into the cellular and molecular mechanisms that differentiate microbeam radiotherapy from broad beam. The purpose of this study was to investigate and compare the whole genome transcriptional response of in vivo microbeam radiotherapy versus broad beam irradiated tumors. We hypothesized that gene expression changes after microbeam radiotherapy are different from those seen after broad beam. We found that in EMT6.5 tumors at 4-48 h postirradiation, microbeam radiotherapy differentially regulates a number of genes, including major histocompatibility complex (MHC) class II antigen gene family members, and other immunity-related genes including Ciita, Ifng, Cxcl1, Cxcl9, Indo and Ubd when compared to broad beam. Our findings demonstrate molecular differences in the tumor response to microbeam versus broad beam irradiation and these differences provide insight into the underlying mechanisms of microbeam radiotherapy and broad beam.

  14. Verification of micro-beam irradiation

    Science.gov (United States)

    Li, Qiongge; Juang, Titania; Beth, Rachel; Chang, Sha; Oldham, Mark

    2015-01-01

    Micro-beam Radiation Therapy (MRT) is an experimental radiation therapy with provocative experimental data indicating potential for improved efficacy in some diseases. Here we demonstrated a comprehensive micro-beam verification method utilizing high resolution (50pm) PRESAGE/Micro-Optical-CT 3D Dosimetry. A small PRESAGE cylindrical dosimeter was irradiated by a novel compact Carbon-Nano-Tube (CNT) field emission based MRT system. The Percentage Depth Dose (PDD), Peak-to-Valley Dose Ratio (PVDR) and beam width (FWHM) data were obtained and analyzed from a three strips radiation experiment. A fast dose drop-off with depth, a preserved beam width with depth (an averaged FWHM across three beams remains constant (405.3um, sigma=13.2um) between depth of 3.0~14.0mm), and a high PVDR value (increases with depth from 6.3 at 3.0mm depth to 8.6 at 14.0mm depth) were discovered during this verification process. Some operating procedures such as precise dosimeter mounting, robust mechanical motions (especially rotation) and stray-light artifact management were optimized and developed to achieve a more accurate and dosimetric verification method.

  15. Microbeam evolution: From single cell irradiation to preclinical studies

    DEFF Research Database (Denmark)

    Ghita, Mihaela; Fernandez-Palomo, Cristian; Fukunaga, Hisanori

    2018-01-01

    Purpose: This review follows the development of microbeam technology from the early days of single cell irradiations, to investigations of specific cellular mechanisms and to the development of new treatment modalities in vivo. A number of microbeam applications are discussed with a focus...... on preclinical modalities and translation towards clinical application. Conclusions: The development of radiation microbeams has been a valuable tool for the exploration of fundamental radiobiological response mechanisms. The strength of micro-irradiation techniques lies in their ability to deliver precise doses...

  16. Conceptual design for real time monitoring of electron microbeam

    International Nuclear Information System (INIS)

    Kim, Ji Seok; Kim, Hyun Ki; Jang, Mee; Choi, Chang Woon; Sun, Gwang Min; Lee, Jai Ki

    2008-01-01

    It is recognized that the microbeam is powerful system to understand the interaction of ionizing radiation with cells. Especially, electron microbeam system is useful to investigate the effect of low-LET radiation for cells. Electron microbeam has been developed in KIRAMS. It can irradiate the small volume in cell level by collimator and electromagnetic field and give local dose to individual cell by controlling the number of electrons. When the electron microbeam irradiates the individual cell, however, there is a possibility to change the current and intended trajectory of electron beam. Because this possibility introduces the uncertainty of dose, it is necessary to monitor the trajectory and current of electron beam. This study deals with development of real time monitoring device to confirm beam quality and to control if necessary during experiment. Consequently we designed dual monitoring device to solve various factors. And we optimize the design by simulation. (author)

  17. Development of microbeam technology to expand applications at TIARA

    Energy Technology Data Exchange (ETDEWEB)

    Kamiya, T.; Satoh, T.; Koka, M. [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency (JAEA) (Japan); Kada, W. [Faculty of Science and Technology, Gunma University (Japan)

    2015-04-01

    Herein, we review the last half decade of progress in ion-microbeam technology and applications at the Takasaki Ion Accelerators for Advanced Radiation Applications facility. Materials were microanalysed with the light-ion-microbeam system by combining micro-particle-induced X-ray and γ-ray emission, nuclear-reaction analysis and micro-ion-beam-induced luminescence to analyse elements, including light elements such as lithium, boron or fluoride, and also their chemical states. For microfabrication, we used particle-beam writing and techniques of maskless patterning to processes materials without etching. The goal was to develop optical, magnetic or other new types of microdevices with both light-ion and the heavy-ion microbeam systems. In addition, techniques were developed to monitor in real time every individual ion injection by using an efficient scintillator or a thin diamond particle detector in both heavy-ion and high-energy heavy-ion microbeam systems.

  18. Electrochemical performances of graphene nanoribbons interlacing hollow NiCo oxide nanocages

    Science.gov (United States)

    Zhao, Xiyu; Li, Xinlu; Huang, Yanchun; Su, Zelong; Long, Junjun; Zhang, Shilei; Sha, Junwei; Wu, Tianli; Wang, Ronghua

    2017-12-01

    A hybrid of graphene nanoribbons (GNRs) interlacing hollow NiCoO2 (G-HNCO) nanocages in a size range of 300 500 nm with rough surface is synthesized by a chemical etching Cu2O templates and followed by GNR interlacing process. The G-HNCO showed high electrochemical performance of oxygen evolution reaction (OER), which exhibited small onset potential of 1.50 V and achieved current densities of 10 mA cm-2 at potentials of 1.62 V. Also, the hybrid delivered high capacitance of 937.8 F g-1 at 1 A g-1 in supercapacitor (SC) tests as well as stable cycling performance in both OER and SC measurements. The approach to synthesize the hybrid is simple and scalable for other graphene nanoribbon-based electrocatalysts. [Figure not available: see fulltext.

  19. Physics study of microbeam radiation therapy with PSI-version of Monte Carlo code GEANT as a new computational tool

    CERN Document Server

    Stepanek, J; Laissue, J A; Lyubimova, N; Di Michiel, F; Slatkin, D N

    2000-01-01

    Microbeam radiation therapy (MRT) is a currently experimental method of radiotherapy which is mediated by an array of parallel microbeams of synchrotron-wiggler-generated X-rays. Suitably selected, nominally supralethal doses of X-rays delivered to parallel microslices of tumor-bearing tissues in rats can be either palliative or curative while causing little or no serious damage to contiguous normal tissues. Although the pathogenesis of MRT-mediated tumor regression is not understood, as in all radiotherapy such understanding will be based ultimately on our understanding of the relationships among the following three factors: (1) microdosimetry, (2) damage to normal tissues, and (3) therapeutic efficacy. Although physical microdosimetry is feasible, published information on MRT microdosimetry to date is computational. This report describes Monte Carlo-based computational MRT microdosimetry using photon and/or electron scattering and photoionization cross-section data in the 1 e V through 100 GeV range distrib...

  20. In situ macromolecular crystallography using microbeams.

    Science.gov (United States)

    Axford, Danny; Owen, Robin L; Aishima, Jun; Foadi, James; Morgan, Ann W; Robinson, James I; Nettleship, Joanne E; Owens, Raymond J; Moraes, Isabel; Fry, Elizabeth E; Grimes, Jonathan M; Harlos, Karl; Kotecha, Abhay; Ren, Jingshan; Sutton, Geoff; Walter, Thomas S; Stuart, David I; Evans, Gwyndaf

    2012-05-01

    Despite significant progress in high-throughput methods in macromolecular crystallography, the production of diffraction-quality crystals remains a major bottleneck. By recording diffraction in situ from crystals in their crystallization plates at room temperature, a number of problems associated with crystal handling and cryoprotection can be side-stepped. Using a dedicated goniometer installed on the microfocus macromolecular crystallography beamline I24 at Diamond Light Source, crystals have been studied in situ with an intense and flexible microfocus beam, allowing weakly diffracting samples to be assessed without a manual crystal-handling step but with good signal to noise, despite the background scatter from the plate. A number of case studies are reported: the structure solution of bovine enterovirus 2, crystallization screening of membrane proteins and complexes, and structure solution from crystallization hits produced via a high-throughput pipeline. These demonstrate the potential for in situ data collection and structure solution with microbeams. © 2012 International Union of Crystallography

  1. Development of the Jyvaeskylae microbeam facility

    Energy Technology Data Exchange (ETDEWEB)

    Norarat, Rattanaporn, E-mail: rattanaporn.norarat@phys.jyu.fi [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), FIN-40014 Jyvaeskylae (Finland); Sajavaara, Timo; Laitinen, Mikko; Heikkinen, Pauli; Ranttila, Kimmo; Ylikorkala, Kari; Haenninen, Vaeinoe; Rossi, Mikko; Jones, Pete [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), FIN-40014 Jyvaeskylae (Finland); Marjomaeki, Varpu; Gilbert, Leona [Department of Environmental and Biological Sciences, University of Jyvaeskylae, P.O. Box 35 (YFL), FIN-40014 Jyvaeskylae (Finland); Whitlow, Harry J. [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), FIN-40014 Jyvaeskylae (Finland)

    2012-02-01

    Research highlights: Black-Right-Pointing-Pointer A MeV ion microbeam for biomedical materials research is being developed. Black-Right-Pointing-Pointer High accuracy scanning using electrostatic post-focus deflection. Black-Right-Pointing-Pointer Imaging and direct lithographic image writing using time-stamping methods. Black-Right-Pointing-Pointer New scanning modes and fluorescence detectors permit low ion-fluence cell imaging. Black-Right-Pointing-Pointer Thermal compensated beam-line support design for high positional accuracy. - Abstract: A new microbeam facility is being constructed at the 1.7 MV Pelletron Accelerator in Jyvaeskylae. The facility is designed for easy upgrading and incorporates a number of innovative features. Initially, it is based on a Heidelberg doublet with a design capability of a 3 Multiplication-Sign 5 {mu}m beamspot at PIXE intensities and later upgraded to nanobeam performance. A thermal-expansion compensated rigid frame mounted on a mechanically isolated floor section is used to support the ion optical components. A compact-post focusing electrostatic deflector is used for high linearity beam scanning. This together with a novel time-stamped data collection (TDC) allows dynamic effects in IBIC, fluorescence bleaching to be studied as well as facilitating multi-resolution image support for low-fluence imaging of cells. The target chamber is fitted with a novel low-cost large working distance optical microscope, extremely compact large solid angle photon detectors as well as conventional secondary electron, PIXE and Scanning Transmission Ion Microscopy (STIM) detectors.

  2. Wide area scanning system and carbon microbeams at the external microbeam facility of the INFN LABEC laboratory in Florence

    Energy Technology Data Exchange (ETDEWEB)

    Giuntini, L. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Massi, M. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Calusi, S. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Castelli, L. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Carraresi, L. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Fedi, M.E.; Gelli, N. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Liccioli, L.; Mandò, P.A.; Mazzinghi, A. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Palla, L. [INFN, Sezione di Pisa and Università di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa (Italy); Romano, F.P. [Consiglio Nazionale delle Ricerche (CNR), Istituto per i Beni Archeologici e Monumentali (IBAM), Via Biblioteca, 4, 95124 Catania (Italy); Istituto Nazionale di Fisica Nucleare (INFN), LNS, Via S.Sofia 62, 95125 Catania (Italy); and others

    2015-04-01

    Recently, developments have been made to the external scanning microbeam of INFN-LABEC laboratory in Florence. A new system for mechanical sample scanning was implemented. This system allows us to acquire large maps (up to 20 × 20 cm{sup 2}), of great interest in the Cultural Heritage field. In parallel, the possibility of using carbon microbeams for experiments, such as, for example, ion beam modification of materials and MeV Secondary Ion Mass Spectrometry, has been investigated. As a test application, Particle Induced X-ray Emission with carbon microbeams has been performed on a lapis lazuli stone. First results for both wide area imaging and external carbon microbeams are briefly reported.

  3. Proceedings of 6th International Microbeam Workshop/12th L.H. Gray Workshop Microbeam Probes of Cellular Radiation Response

    International Nuclear Information System (INIS)

    Prise, Kevin M.

    2004-01-01

    The extended abstracts which are submitted here present a summary of the proceedings of the 6th International Workshop/12th LH Gray Workshop: Microbeam Probes of Cellular Radiation Response, held at St. Catherine's College, University of Oxford, UK on March, 29th-31st, 2003. In 1993 the 4th LH Gray Workshop entitled ''Microbeam Probes of Cellular Radiation Response'' was held at the Gray Cancer Institute in Northwood. This was organized by Prof BD Michael, Dr M. Folkard and Dr KM Prise and brought together 40 participants interested in developing and applying new microbeam technology to problems in radiation biology (1). The workshop was an undoubted success and has spawned a series of subsequent workshops every two years. In the past, these workshops have been highly successful in bringing together groups interested in developing and applying micro-irradiation techniques to the study of cell and tissue damage by ionizing radiations. Following the first microbeam workshop, there has been a rapid growth in the number of centres developing radiobiology microbeams, or planning to do so and there are currently 15-20 worldwide. Much of the recent research using microbeams has used them to study low-dose effects and ''non-targeted'' responses such bystander effects, genomic instability and adaptive responses. The goal of the 6th workshop was to build on our knowledge of the development of microbeam approaches and the application to radiation biology in the future with the meeting stretching over a 3 day period. Over 80 participants reviewed the current state of radiobiology microbeam research worldwide and reported on new technological developments both in the fields of physics and biology

  4. Characterization and quantification of cerebral edema induced by synchrotron x-ray microbeam radiation therapy

    International Nuclear Information System (INIS)

    Serduc, Raphael; Looij, Yohan van de; Francony, Gilles; Verdonck, Olivier; Sanden, Boudewijn van der; Farion, Regine; Segebarth, Christoph; Remy, Chantal; Lahrech, Hana; Laissue, Jean; Braeuer-Krisch, Elke; Siegbahn, Erik Albert; Bravin, Alberto; Prezado, Yolanda

    2008-01-01

    Cerebral edema is one of the main acute complications arising after irradiation of brain tumors. Microbeam radiation therapy (MRT), an innovative experimental radiotherapy technique using spatially fractionated synchrotron x-rays, has been shown to spare radiosensitive tissues such as mammal brains. The aim of this study was to determine if cerebral edema occurs after MRT using diffusion-weighted MRI and microgravimetry. Prone Swiss nude mice's heads were positioned horizontally in the synchrotron x-ray beam and the upper part of the left hemisphere was irradiated in the antero-posterior direction by an array of 18 planar microbeams (25 mm wide, on-center spacing 211 mm, height 4 mm, entrance dose 312 Gy or 1000 Gy). An apparent diffusion coefficient (ADC) was measured at 7 T 1, 7, 14, 21 and 28 days after irradiation. Eventually, the cerebral water content (CWC) was determined by microgravimetry. The ADC and CWC in the irradiated (312 Gy or 1000 Gy) and in the contralateral non-irradiated hemispheres were not significantly different at all measurement times, with two exceptions: (1) a 9% ADC decrease (p < 0.05) was observed in the irradiated cortex 1 day after exposure to 312 Gy, (2) a 0.7% increase (p < 0.05) in the CWC was measured in the irradiated hemispheres 1 day after exposure to 1000 Gy. The results demonstrate the presence of a minor and transient cellular edema (ADC decrease) at 1 day after a 312 Gy exposure, without a significant CWC increase. One day after a 1000 Gy exposure, the CWC increased, while the ADC remained unchanged and may reflect the simultaneous presence of cellular and vasogenic edema. Both types of edema disappear within a week after microbeam exposure which may confirm the normal tissue sparing effect of MRT. For more information on this article, see medicalphysicsweb.org

  5. Characterization and quantification of cerebral edema induced by synchrotron x-ray microbeam radiation therapy

    Science.gov (United States)

    Serduc, Raphaël; van de Looij, Yohan; Francony, Gilles; Verdonck, Olivier; van der Sanden, Boudewijn; Laissue, Jean; Farion, Régine; Bräuer-Krisch, Elke; Siegbahn, Erik Albert; Bravin, Alberto; Prezado, Yolanda; Segebarth, Christoph; Rémy, Chantal; Lahrech, Hana

    2008-03-01

    Cerebral edema is one of the main acute complications arising after irradiation of brain tumors. Microbeam radiation therapy (MRT), an innovative experimental radiotherapy technique using spatially fractionated synchrotron x-rays, has been shown to spare radiosensitive tissues such as mammal brains. The aim of this study was to determine if cerebral edema occurs after MRT using diffusion-weighted MRI and microgravimetry. Prone Swiss nude mice's heads were positioned horizontally in the synchrotron x-ray beam and the upper part of the left hemisphere was irradiated in the antero-posterior direction by an array of 18 planar microbeams (25 mm wide, on-center spacing 211 mm, height 4 mm, entrance dose 312 Gy or 1000 Gy). An apparent diffusion coefficient (ADC) was measured at 7 T 1, 7, 14, 21 and 28 days after irradiation. Eventually, the cerebral water content (CWC) was determined by microgravimetry. The ADC and CWC in the irradiated (312 Gy or 1000 Gy) and in the contralateral non-irradiated hemispheres were not significantly different at all measurement times, with two exceptions: (1) a 9% ADC decrease (p edema (ADC decrease) at 1 day after a 312 Gy exposure, without a significant CWC increase. One day after a 1000 Gy exposure, the CWC increased, while the ADC remained unchanged and may reflect the simultaneous presence of cellular and vasogenic edema. Both types of edema disappear within a week after microbeam exposure which may confirm the normal tissue sparing effect of MRT. For more information on this article, see medicalphysicsweb.org

  6. Characterization and quantification of cerebral edema induced by synchrotron x-ray microbeam radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Serduc, Raphael; Looij, Yohan van de; Francony, Gilles; Verdonck, Olivier; Sanden, Boudewijn van der; Farion, Regine; Segebarth, Christoph; Remy, Chantal; Lahrech, Hana [INSERM, U836, F-38043 Grenoble (France); Laissue, Jean [Institute of Pathology, University of Bern (Switzerland); Braeuer-Krisch, Elke; Siegbahn, Erik Albert; Bravin, Alberto; Prezado, Yolanda [European Synchrotron Radiation Facility, F-38043 Grenoble (France)], E-mail: serduc@esrf.fr

    2008-03-07

    Cerebral edema is one of the main acute complications arising after irradiation of brain tumors. Microbeam radiation therapy (MRT), an innovative experimental radiotherapy technique using spatially fractionated synchrotron x-rays, has been shown to spare radiosensitive tissues such as mammal brains. The aim of this study was to determine if cerebral edema occurs after MRT using diffusion-weighted MRI and microgravimetry. Prone Swiss nude mice's heads were positioned horizontally in the synchrotron x-ray beam and the upper part of the left hemisphere was irradiated in the antero-posterior direction by an array of 18 planar microbeams (25 mm wide, on-center spacing 211 mm, height 4 mm, entrance dose 312 Gy or 1000 Gy). An apparent diffusion coefficient (ADC) was measured at 7 T 1, 7, 14, 21 and 28 days after irradiation. Eventually, the cerebral water content (CWC) was determined by microgravimetry. The ADC and CWC in the irradiated (312 Gy or 1000 Gy) and in the contralateral non-irradiated hemispheres were not significantly different at all measurement times, with two exceptions: (1) a 9% ADC decrease (p < 0.05) was observed in the irradiated cortex 1 day after exposure to 312 Gy, (2) a 0.7% increase (p < 0.05) in the CWC was measured in the irradiated hemispheres 1 day after exposure to 1000 Gy. The results demonstrate the presence of a minor and transient cellular edema (ADC decrease) at 1 day after a 312 Gy exposure, without a significant CWC increase. One day after a 1000 Gy exposure, the CWC increased, while the ADC remained unchanged and may reflect the simultaneous presence of cellular and vasogenic edema. Both types of edema disappear within a week after microbeam exposure which may confirm the normal tissue sparing effect of MRT. For more information on this article, see medicalphysicsweb.org.

  7. High resolution X-ray fluorescence imaging for a microbeam radiation therapy treatment planning system

    Science.gov (United States)

    Chtcheprov, Pavel; Inscoe, Christina; Burk, Laurel; Ger, Rachel; Yuan, Hong; Lu, Jianping; Chang, Sha; Zhou, Otto

    2014-03-01

    Microbeam radiation therapy (MRT) uses an array of high-dose, narrow (~100 μm) beams separated by a fraction of a millimeter to treat various radio-resistant, deep-seated tumors. MRT has been shown to spare normal tissue up to 1000 Gy of entrance dose while still being highly tumoricidal. Current methods of tumor localization for our MRT treatments require MRI and X-ray imaging with subject motion and image registration that contribute to the measurement error. The purpose of this study is to develop a novel form of imaging to quickly and accurately assist in high resolution target positioning for MRT treatments using X-ray fluorescence (XRF). The key to this method is using the microbeam to both treat and image. High Z contrast media is injected into the phantom or blood pool of the subject prior to imaging. Using a collimated spectrum analyzer, the region of interest is scanned through the MRT beam and the fluorescence signal is recorded for each slice. The signal can be processed to show vascular differences in the tissue and isolate tumor regions. Using the radiation therapy source as the imaging source, repositioning and registration errors are eliminated. A phantom study showed that a spatial resolution of a fraction of microbeam width can be achieved by precision translation of the mouse stage. Preliminary results from an animal study showed accurate iodine profusion, confirmed by CT. The proposed image guidance method, using XRF to locate and ablate tumors, can be used as a fast and accurate MRT treatment planning system.

  8. Synchrotron microbeam radiation therapy induces hypoxia in intracerebral gliosarcoma but not in the normal brain

    International Nuclear Information System (INIS)

    Bouchet, Audrey; Lemasson, Benjamin; Christen, Thomas; Potez, Marine; Rome, Claire; Coquery, Nicolas; Le Clec’h, Céline; Moisan, Anaick; Bräuer-Krisch, Elke; Leduc, Géraldine; Rémy, Chantal; Laissue, Jean A.; Barbier, Emmanuel L.; Brun, Emmanuel; Serduc, Raphaël

    2013-01-01

    Purpose: Synchrotron microbeam radiation therapy (MRT) is an innovative irradiation modality based on spatial fractionation of a high-dose X-ray beam into lattices of microbeams. The increase in lifespan of brain tumor-bearing rats is associated with vascular damage but the physiological consequences of MRT on blood vessels have not been described. In this manuscript, we evaluate the oxygenation changes induced by MRT in an intracerebral 9L gliosarcoma model. Methods: Tissue responses to MRT (two orthogonal arrays (2 × 400 Gy)) were studied using magnetic resonance-based measurements of local blood oxygen saturation (MR S O 2 ) and quantitative immunohistology of RECA-1, Type-IV collagen and GLUT-1, marker of hypoxia. Results: In tumors, MR S O 2 decreased by a factor of 2 in tumor between day 8 and day 45 after MRT. This correlated with tumor vascular remodeling, i.e. decrease in vessel density, increases in half-vessel distances (×5) and GLUT-1 immunoreactivity. Conversely, MRT did not change normal brain MR S O 2 , although vessel inter-distances increased slightly. Conclusion: We provide new evidence for the differential effect of MRT on tumor vasculature, an effect that leads to tumor hypoxia. As hypothesized formerly, the vasculature of the normal brain exposed to MRT remains sufficiently perfused to prevent any hypoxia

  9. In situ macromolecular crystallography using microbeams

    International Nuclear Information System (INIS)

    Axford, Danny; Owen, Robin L.; Aishima, Jun; Foadi, James; Morgan, Ann W.; Robinson, James I.; Nettleship, Joanne E.; Owens, Raymond J.; Moraes, Isabel; Fry, Elizabeth E.; Grimes, Jonathan M.; Harlos, Karl; Kotecha, Abhay; Ren, Jingshan; Sutton, Geoff; Walter, Thomas S.; Stuart, David I.; Evans, Gwyndaf

    2012-01-01

    A sample environment for mounting crystallization trays has been developed on the microfocus beamline I24 at Diamond Light Source. The technical developments and several case studies are described. Despite significant progress in high-throughput methods in macromolecular crystallography, the production of diffraction-quality crystals remains a major bottleneck. By recording diffraction in situ from crystals in their crystallization plates at room temperature, a number of problems associated with crystal handling and cryoprotection can be side-stepped. Using a dedicated goniometer installed on the microfocus macromolecular crystallography beamline I24 at Diamond Light Source, crystals have been studied in situ with an intense and flexible microfocus beam, allowing weakly diffracting samples to be assessed without a manual crystal-handling step but with good signal to noise, despite the background scatter from the plate. A number of case studies are reported: the structure solution of bovine enterovirus 2, crystallization screening of membrane proteins and complexes, and structure solution from crystallization hits produced via a high-throughput pipeline. These demonstrate the potential for in situ data collection and structure solution with microbeams

  10. Negative Knudsen force on heated microbeams

    KAUST Repository

    Zhu, Taishan

    2011-11-18

    Knudsen force acting on a heated microbeam adjacent to a cold substrate in a rarefied gas is a mechanical force created by unbalanced thermal gradients. The measured force has its direction pointing towards the side with a lower thermal gradient and its magnitude vanishes in both continuum and free-molecule limits. In our previous study, negative Knudsen forces were discovered at the high Knudsen regime before diminishing in the free-molecule limit. Such a phenomenon was, however, neither observed in experiment [A. Passian et al., Phys. Rev. Lett. 90, 124503 (2003)], nor captured in the latest numerical study [J. Nabeth et al., Phys. Rev. E 83, 066306 (2011)]. In this paper, the existence of such a negative Knudsen force is further confirmed using both numerical simulation and theoretical analysis. The asymptotic order of the Knudsen force near the collisionless limit is analyzed and the analytical expression of its leading term is provided, from which approaches for the enhancement of negative Knudsen forces are proposed. The discovered phenomenon could find its applications in novel mechanisms for pressure sensing and actuation.

  11. Feasibility of employing thick microbeams from superficial and orthovoltage kVp x-ray tubes for radiotherapy of superficial cancers

    Science.gov (United States)

    Kamali-Zonouzi, P.; Shutt, A.; Nisbet, A.; Bradley, D. A.

    2017-11-01

    Preclinical investigations of thick microbeams show these to be feasible for use in radiotherapeutic dose delivery. To create the beams we access a radiotherapy x-ray tube that is familiarly used within a conventional clinical environment, coupling this with beam-defining grids. Beam characterisation, both single and in the form of arrays, has been by use of both MCNP simulation and direct Gafchromic EBT film dosimetry. As a first step in defining optimal exit-beam profiles over a range of beam energies, simulation has been made of the x-ray tube and numbers of beam-defining parallel geometry grids, the latter being made to vary in thickness, slit separation and material composition. For a grid positioned after the treatment applicator, and of similar design to those used in the first part of the study, MCNP simulation and Gafchromic EBT film were then applied in examining the resultant radiation profiles. MCNP simulations and direct dosimetry both show useful thick microbeams to be produced from the x-ray tube, with peak-to-valley dose ratios (PVDRs) in the approximate range 8.8-13.9. Although the potential to create thick microbeams using radiotherapy x-ray tubes and a grid has been demonstrated, Microbeam Radiation Therapy (MRT) would still need to be approved outside of the preclinical setting, a viable treatment technique of clinical interest needing to benefit for instance from substantially improved x-ray tube dose rates.

  12. Study of the Contact Resistance of Interlaced Stainless Steel Yarns Embedded in Hybrid Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Vasile Simona

    2017-06-01

    Full Text Available The contact resistance of two interlacing electro-conductive yarns embedded in a hybrid woven fabric will constitute a problem for electro-conductive textiles under certain circumstances. A high contact resistance can induce hotspots, while a variable contact resistance may cause malfunctioning of the components that are interconnected by the electro-conductive yarns. Moreover, the contact robustness should be preserved over time and various treatments such as washing or abrading should not alter the functioning of the electro-conductive textiles. The electrical resistance developed in the contact point of two interlacing electro-conductive yarns is the result of various factors. The influence of diameter of the electro-conductive stainless steel yarns, the weave pattern, the weft density, and the abrasion on the contact resistance was investigated. Hybrid polyester fabrics were produced according to the design of experiments (DoE and statistical models were found that describe the variation of the contact resistance with the selected input parameters. It was concluded that the diameter of the stainless steel warp and weft yarns has a statistically significant influence on the contact resistance regardless of the weave. Weft density had a significant influence on the contact resistance but only in case of the twill fabrics. Abrasion led to an increase in contact resistance regardless of the weave pattern and the type of stainless steel yarn that was used. Finally, a combination of parameters that leads to plain and twill fabrics with low contact resistance and robust contacts is recommended.

  13. He+ and H+ microbeam damage, swelling and annealing in diamonds

    International Nuclear Information System (INIS)

    Dooley, S.P.; Jamieson, D.N.; Prawer, S.

    1992-01-01

    The effects of scanned 2 MeV He + and 1.4 MeV H + microbeam irradiation on unimplanted and P implanted diamond are discussed. Although diamond was found to be resistant to lattice defect production, it was found to swell very rapidly in comparison with other materials, giving rise to serious swelling induced dechanneling at scan edges at relatively low doses (10 17 /cm 2 for 2 MeV He + ). Microbeams annealed the damage due to a 1.5 μm deep Phosphorus implantation at a dose of 10 15 P + /cm 2 . The implantation damage was reduced at a dose of (1.6 x 10 17 /cm 2 ) by up to 21 % for 2 MeV He + irradiation, up to 16% for high flux 1.4 MeV H + irradiation and 12% for low flux H + irradiation. For the choice of analysis beam, all these beam effects were found to be most significant for He + microbeams, so H + microbeams should be used for analysis of diamond unless high depth resolution is required. 13 refs., 10 figs

  14. A proton microbeam deflection system to scan target surfaces

    International Nuclear Information System (INIS)

    Heck, D.

    1978-12-01

    A system to deflect the proton beam within the Karlsruhe microbeam setup is described. The deflection is achieved whithin a transverse electrical field generated between parallel electrodes. Their tension is controlled by a pattern generator, thus enabling areal and line scans with a variable number of scan points at variable scan speed. The application is demonstrated at two different examples. (orig.) [de

  15. Proton microbeam irradiation effects on PtBA polymer

    Indian Academy of Sciences (India)

    Unknown

    polymer is studied using the optical and secondary electron microscopic experimental methods. Keywords. Ion micro-beam; pattern ... or X-ray photons) or charged particles (electrons, low energy heavy ions, high energy light ... relatively less dose but the aspect ratios obtained are smaller compared to those obtained using ...

  16. Experimental Setup for Studying Guiding of Proton Microbeam

    OpenAIRE

    Nagy, G. U. L.; Rajta, I.; Bereczky, R. J.; Tőkési, K.

    2014-01-01

    We present the design and construction of our experimental setup for studying the transmission of proton microbeam through a single, cylindrical shape, macroscopic insulating capillary. The intensity as a function of time, the energy distribution as a function of the transmission and the deflection of the transmitted particles can be measured with the new setup.

  17. Biomimetic synthesis of interlaced mesh structures TiO{sub 2} nanofibers with enhanced photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guanghui [Tianjin Key Laboratory of Applied Catalysis Science and Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 China (China); Collaborative Innovation Center of Chemical Science and Engineering(Tianjin), Tianjin 300072 China (China); Zhang, Tianyong, E-mail: tyzhang@tju.edu.cn [Tianjin Key Laboratory of Applied Catalysis Science and Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 China (China); Collaborative Innovation Center of Chemical Science and Engineering(Tianjin), Tianjin 300072 China (China); Li, Bin, E-mail: libin@tju.edu.cn [Tianjin Key Laboratory of Applied Catalysis Science and Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 China (China); Collaborative Innovation Center of Chemical Science and Engineering(Tianjin), Tianjin 300072 China (China); Zhang, Xia; Chen, Xingwei [Tianjin Key Laboratory of Applied Catalysis Science and Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 China (China)

    2016-05-25

    A facile and economical method assisted by PPs (the spongy white peels of pomelo peel) was applied for preparing interlaced mesh structures TiO{sub 2} nanofibers by a liquid impregnation method followed by a calcination process in this study. And the as-prepared materials were comprehensively investigated by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectra, UV-vis diffuse reflectance spectroscopy, photoluminescence spectra and N{sub 2} adsorption-desorption. The resultant TiO{sub 2} materials exhibit unique morphology, in which the curly nanofibers with the diameter about 90 nm interweave each other for assembling hierarchical mesh structures and there are abundant grooves on the surface of the nanofibers. During the bio-inspired synthetic process, the PPs play important roles as template and induction for forming the hierarchical mesh structures of TiO{sub 2} nanofibers. Furthermore, some of the as-prepared TiO{sub 2} samples exhibit 99% degradation rate for methyl orange in 30 min under UV light irradiation, which can be ascribed to the larger surface area and the unique hierarchical mesh structures. In addition, the stability tests of 5 cycling runs of the photocatalysts indicate that the as-prepared TiO{sub 2} nanofibers can be applied as a practical photocatalyst for degrading organic dyes under UV light irradiation. Therefore, hopefully, the strategy for preparing the TiO{sub 2} nanofibers can be extended to design many more powerful photocatalysts for the environmental remediation in the near future. - Graphical abstract: The TiO{sub 2} nanofibers with interlaced mesh structures were prepared with PPs (the spongy white peels of pomelo peel) as the reactive substrate and directing template, and titanium tetrachloride (TiCl{sub 4}) as titanium resource. And the as-prepared TiO{sub 2} samples exhibit highly photocatalytic activity and good stability for degrading methyl orange under UV light irradiation. - Highlights: • A

  18. 3D shape measurement for moving scenes using an interlaced scanning colour camera

    International Nuclear Information System (INIS)

    Cao, Senpeng; Cao, Yiping; Lu, Mingteng; Zhang, Qican

    2014-01-01

    A Fourier transform deinterlacing algorithm (FTDA) is proposed to eliminate the blurring and dislocation of the fringe patterns on a moving object captured by an interlaced scanning colour camera in phase measuring profilometry (PMP). Every frame greyscale fringe from three colour channels of every colour fringe is divided into even and odd field fringes respectively, each of which is respectively processed by FTDA. All of the six frames deinterlaced fringes from one colour fringe form two sets of three-step phase-shifted greyscale fringes, with which two 3D shapes corresponding to two different moments are reconstructed by PMP within a frame period. The deinterlaced fringe is identical with the exact frame fringe at the same moment theoretically. The simulation and experiments show its feasibility and validity. The method doubles the time resolution, maintains the precision of the traditional phase measurement profilometry, and has potential applications in the moving and online object’s 3D shape measurements. (paper)

  19. Static Response of Microbeams due to Capillary and Electrostatic Forces

    KAUST Repository

    Bataineh, Ahmad M.

    2016-03-07

    Micro-sensors or micro-switches usually operate under the effect of electrostatic force and could face some environmental effects like humidity, which may lead to condensation underneath the beams and create strong capillary forces. Those tiny structures are principally made of microbeams that can undergo instabilities under the effect of those created huge capillary forces. In fact, during the fabrication of microbeams, there is an important step to separate the beam from its substrate (wet etching). After this step, the microstructure is dried, which may causes the onset of some droplets of water trapped underneath the beam that could bring about a huge capillary force pulling it toward its substrate. If this force is bigger than the microbeam\\'s restoring force, it will become stuck to the substrate. This paper investigates the instability scenarios of both clamped-clamped (straight and curved) and cantilever (straight and curled) microbeams under the effect of capillary and/or electrostatic forces. The reduced order modeling (ROM) based on the Galerkin procedure is used to solve the nonlinear beam equations. The non-ideal boundaries are modeled by adding springs. The volume of the fluid between the beam and the substrate underneath it is varied and the relation between the volume of the water and the stability of the beam is shown. An analysis for the factors of which should be taken in to consideration in the fabrication processes to overcome the instability due to huge capillary forces is done. Also the size of the electrode for the electrostatic force is varied to show the effect on the micro-switch stability. A variation of the pull-in voltage with some specific beam parameters and with more than one case of electrode size is shown. It is found that capillary forces have a pronounced effect on the stability of microbeams. It is also found that the pull-in length decreases as the electrode size increases. It is also shown that the pull-in voltage decreases

  20. In situ monitoring of polyimide windows for external ion microbeams

    International Nuclear Information System (INIS)

    Kinomura, A.; Mokuno, Y.; Chayahara, A.; Tsubouchi, N.; Horino, Y.

    2003-01-01

    Damage of polyimide windows for external ion microbeams was monitored by analyzing backscattering protons from the window. A 1.5 MeV proton microbeam focused to approximately 50 x 50 μm 2 was transmitted through the polyimide window from vacuum to oxygen atmosphere. The changes in backscattering spectra of the window were monitored as a function of irradiation dose up to 2 x 10 18 H + /cm 2 . For comparison, the polyimide window was irradiated in vacuum in the same way as the oxygen case. The backscattering spectra drastically changed in the case of oxygen. We observed that the carbon spectrum width, corresponding to the thickness of the window, substantially decreased with increasing the irradiation dose. The in situ monitoring of backscattering protons demonstrated the ability to detect the damage of the window and to predict the rupture of the window

  1. Converse flexoelectric effect in comb electrode piezoelectric microbeam

    International Nuclear Information System (INIS)

    Shen, Zhiyuan; Chen, Wei

    2012-01-01

    We demonstrate the converse flexoelectric effect in a lead zirconate titanate microbeam. The fringe electric field of a comb electrode induces converse flexoelectric responses in uniformly poled and depoled beams. The simulated electric field distribution shows that bending of the beam is induced by piezoelectric and μ 11 , μ 12 flexoelectric coefficients. Simulations indicate that piezoelectric displacement occurs in different directions in the two opposite poled samples while flexoelectric displacement remains the same. This finding is verified by the displacement measurement results. -- Highlights: ► We demonstrate the converse flexoelectric effect in a PZT microbeam. ► Beams with upward and downward poling states are fabricated by MEMS technique. ► Converse flexoelectric deformation is induced by the fringe field. ► Electric field distribution is calculated by finite element analysis. ► The simulation results are verified by impedance and displacement measurements.

  2. Multifrequency Excitation of a Clamped-Clamped Microbeam

    KAUST Repository

    Jaber, Nizar R.

    2016-01-20

    We present analytical and experimental investigation of an electrically actuated clamped-clamped microbeam under a twosource harmonic excitation. The first frequency is swept around the first mode of vibration where the second one is fixed. These microbeams are fabricated using polyimide as structural layer coated with nickel form top and chromium and gold layers from bottom. We demonstrate the excitation of additive and subtractive type resonance. We show that by properly tuning the frequency and the amplitude of the excitation force, the frequency bandwidth of the resonator is increased. Theoretically, we solved the eigenvalue problem for different axial forces to find the natural frequencies ratio that match the experimental values. Using Galerkin method, a reduced order model is derived to simulate the static and dynamic response of the device where using three symmetric mode shapes provided a good agreement with experimental data. © Copyright 2015 by ASME.

  3. Beam characterisation of the KIRAMS electron microbeam system

    International Nuclear Information System (INIS)

    Sun, G. M.; Kim, E. H.; Song, K. B.; Jang, M.

    2006-01-01

    An electron microbeam system has been installed at the Korea Inst. of Radiological and Medical Sciences (KIRAMS) for use in radiation biology studies. The electron beam is produced from a commercial electron gun, and the beam size is defined by a 5 μm diameter pinhole. Beam energy can be varied in the range of 1-100 keV, covering a range of linear energy transfer from 0.4 to 12.1 keV μm -1 . The micrometer-sized electron beam selectively irradiates cells cultured in a Mylar-bottomed dish. The positioning of target cells one by one onto the beam exit is automated, as is beam shooting. The electron beam entering the target cells has been calibrated using a Passivated Implanted Planar Silicon (PIPS) detector. This paper describes the KIRAMS microbeam cell irradiation system and its beam characteristics. (authors)

  4. Online imaging of initial DNA damages at the PTB microbeam

    International Nuclear Information System (INIS)

    Giesen, U.; Langner, F.; Mielke, C.; Mosconi, M.; Dirks, W. G.

    2011-01-01

    In an inter-disciplinary collaboration of Physikalisch-Technische Bundesanstalt (PTB), German Collection of Microorganisms and Cell Cultures (DSMZ) and Heinrich-Heine Univ., live-cell imaging has been established at the charged-particle microbeam facility of PTB. Candidate genes participating in DNA strand-break repair pathways such as PARP-1, MRE11, MSH2, MDC1 and p53BP1 have been modified to generate fluorescent fusion proteins. Using multi-cistronic expression vectors, stable genomic integration was achieved in HT-1080 fibroblasts. The aim of this study is to characterise and use these highly reliable cell lines for studying initial steps of DNA damage responses and kinetics of repair after microbeam irradiation with high- and low-linear energy transfer (LET) particles in living cells at physiological conditions. (authors)

  5. Energy distribution of proton microbeam transmitted through two flat plates

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, G.U.L.; Rajta, I.; Bereczky, R.J.; Tőkési, K.

    2015-07-01

    The transmission of 1 MeV proton microbeam passing between two parallel flat plates was investigated. Three different materials were used in our experiments. As insulators we used Polytetrafluoroethylene and borosilicate glass plates and glass with gold layer on the surface as conductor. The surface of the plates was parallel to the beam axis and one of the plates was moved towards the beam. The energy distribution and the deflection of the transmitted beam were measured as the function of the sample distance relative to the beam. We found systematic differences between the behaviour of the metallic and insulator samples. The proton microbeam suffered significant deflection towards the sample surface due to the image acceleration when using conductor material. In case of the glass and Polytetrafluoroethylene plates the beam was deflected into the opposite direction, and the incident protons did not suffer significant energy loss, which is the consequence of the guiding effect.

  6. A novel micro-structured reference material for microbeam analysis

    Science.gov (United States)

    Wätjen, Uwe; Dücsö, Csaba; Tajani, Antonella; Munnik, Frans; Lechtenberg, Frank

    2000-03-01

    In order to determine the beam spot size and the linear or raster scanning properties of microprobe analytical systems, a novel certified reference material (CRM) has been developed by IRMM, consisting of permalloy (81% Ni, 19% Fe) strip patterns of different widths on a silicon substrate. The general layout of this micro-structured reference material with pattern sizes ranging from 2 to 100 μm, fabricated with production schemes of microelectronics circuitry on silicon wafers, is discussed. The large size range of the individual pattern structures makes the material equally applicable to very fine and less focused microbeams. Several long distances between characteristic patterns as well as broad line widths of selected structures are certified for each individual chip. First chips of this material were investigated with high-energy ion microprobes as well as with X-ray microprobes with capillary optics. Due to the very good definition of the metal lines and their edge profiles, line scan results of XRF, PIXE or RBS can be directly converted to spot size and microbeam profile. A special set of micro-structures on the CRM chips allows to obtain quantitative information about the "skirt" of microbeams.

  7. Laser microtreatment for genetic manipulations and DNA diagnostics by a combination of microbeam and photonic tweezers (laser microbeam trap)

    Science.gov (United States)

    Greulich, Karl-Otto; Monajembashi, Shamci; Celeda, D.; Endlich, N.; Eickhoff, Holger; Hoyer, Carsten; Leitz, G.; Weber, Gerd; Scheef, J.; Rueterjans, H.

    1994-12-01

    Genomes of higher organisms are larger than one typically expects. For example, the DNA of a single human cell is almost two meters long, the DNA in the human body covers the distance Earth-Sun approximately 140 times. This is often not considered in typical molecular biological approaches for DNA diagnostics, where usually only DNA of the length of a gene is investigated. Also, one basic aspect of sequencing the human genome is not really solved: the problem how to prepare the huge amounts of DNA required. Approaches from biomedical optics combined with new developments in single molecule biotechnology may at least contribute some parts of the puzzle. A large genome can be partitioned into portions comprising approximately 1% of the whole DNA using a laser microbeam. The single DNA fragment can be amplified by the polymerase chain reaction in order to obtain a sufficient amount of molecules for conventional DNA diagnostics or for analysis by octanucleotide hybridization. When not amplified by biotechnological processes, the individual DNA molecule can be visualized in the light microscope and can be manipulated and dissected with the laser microbeam trap. The DNA probes obtained by single molecule biotechnology can be employed for fluorescence in situ introduced into plant cells and subcellular structures even when other techniques fail. Since the laser microbeam trap allows to work in the interior of a cell without opening it, subcellular structures can be manipulated. For example, in algae, such structures can be moved out of their original position and used to study intracellular viscosities.

  8. Aluminium Matrix Composites Reinforced with Co-continuous Interlaced Phases Aluminium-alumina Needles

    Directory of Open Access Journals (Sweden)

    Elvio de Napole Gregolin

    2002-09-01

    Full Text Available An Al-5SiO2 (5 wt% of SiO2 aluminium matrix fiber composite was produced where the reinforcement consists of fossil silica fibers needles. After being heat-treated at 600 °C, the original fiber morphology was retained but its microstructure changed from solid silica to an interconnected (Al-Si/Al2O3 interlaced structure named co-continuous composite. A technique of powder metallurgy, using commercial aluminium powder and the silica fibers as starting materials, followed by hot extrusion, was used to produce the composite. The co-continuous microstructure was obtained partially or totally on the fibers as a result of the reaction, which occurs during the heat treatment, first by solid diffusion and finally by the liquid Al-Si in local equilibrium, formed with the silicon released by reaction. The internal structure of the fibers was characterized using field emission electron microscope (FEG-SEM and optical microscopy on polished and fractured samples.

  9. Study of transient current induced by heavy-ion microbeams in Si and GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Hirao, Toshio; Nashiyama, Isamu; Kamiya, Tomihiro; Suda, Tamotu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    Heavy-ion microbeams were applied to the study of mechanism of single event upset (SEU). Transient current induced in p{sup +}n junction diodes by strike of heavy ion microbeam were measured by using a high-speed digitizing sampling system. (author)

  10. Monte Carlo study of the influence of energy spectra, mesh size, high Z element on dose and PVDR based on 1-D and 3-D heterogeneous mouse head phantom for Microbeam Radiation Therapy.

    Science.gov (United States)

    Lin, Hui; Jing, Jia; Xu, Liangfeng; Mao, Xiaoli

    2017-12-01

    To evaluate the influence of energy spectra, mesh sizes, high Z element on dose and PVDR in Microbeam Radiation Therapy (MRT) based on 1-D analogy-mouse-head-model (1-D MHM) and 3-D voxel-mouse-head-phantom (3-D VMHP) by Monte Carlo simulation. A Microbeam-Array-Source-Model was implemented into EGSnrc/DOSXYZnrc. The microbeam size is assumed to be 25μm, 50μm or 75μm in thickness and fixed 1mm in height with 200μmc-t-c. The influence of the energy spectra of ID17@ESRF and BMIT@CLS were investigated. The mesh size was optimized. PVDR in 1-D MHM and 3-D VMHP was compared with the homogeneous water phantom. The arc influence of 3-D VMHP filled with water (3-D VMHWP) was compared with the rectangle phantom. PVDR of the lower BMIT@CLS spectrum is 2.4times that of ID17@ESRF for lower valley dose. The optimized mesh is 5µm for 25µm, and 10µm for 50µm and 75µm microbeams with 200µmc-t-c. A 500μm skull layer could make PVDR difference up to 62.5% for 1-D MHM. However this influence is limited (influence is limited for the more depth (influence of 3-D heterogeneous media. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  11. The InterLACE study: Design, data harmonization and characteristics across 20 studies on women’s health

    Science.gov (United States)

    Mishra, Gita D.; Chung, Hsin-Fang; Pandeya, Nirmala; Dobson, Annette J.; Jones, Lee; Avis, Nancy E.; Crawford, Sybil L.; Gold, Ellen B.; Brown, Daniel; Sievert, Lynette L.; Brunner, Eric; Cade, Janet E.; Burley, Victoria J.; Greenwood, Darren C.; Giles, Graham G.; Bruinsma, Fiona; Goodman, Alissa; Hayashi, Kunihiko; Lee, Jung Su; Mizunuma, Hideki; Kuh, Diana; Cooper, Rachel; Hardy, Rebecca; Obermeyer, Carla Makhlouf; Lee, Kathryn A.; Simonsen, Mette Kildevæld; Yoshizawa, Toyoko; Woods, Nancy F.; Mitchell, Ellen S.; Hamer, Mark; Demakakos, Panayotes; Sandin, Sven; Adami, Hans-Olov; Weiderpass, Elisabete; Anderson, Debra

    2017-01-01

    Objectives The International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events (InterLACE) project is a global research collaboration that aims to advance understanding of women’s reproductive health in relation to chronic disease risk by pooling individual participant data from several cohort and cross-sectional studies. The aim of this paper is to describe the characteristics of contributing studies and to present the distribution of demographic and reproductive factors and chronic disease outcomes in InterLACE. Study design InterLACE is an individual-level pooled study of 20 observational studies (12 of which are longitudinal) from ten countries. Variables were harmonized across studies to create a new and systematic synthesis of life-course data. Main outcome measures Harmonized data were derived in three domains: 1) socio-demographic and lifestyle factors, 2) female reproductive characteristics, and 3) chronic disease outcomes (cardiovascular disease (CVD) and diabetes). Results InterLACE pooled data from 229,054 mid-aged women. Overall, 76% of the women were Caucasian and 22% Japanese; other ethnicities (of 300 or more participants) included Hispanic/Latin American (0.2%), Chinese (0.2%), Middle Eastern (0.3%), African/black (0.5%), and Other (1.0%). The median age at baseline was 47 years (Inter-quartile range (IQR): 41–53), and that at the last follow-up was 56 years (IQR: 48–64). Regarding reproductive characteristics, half of the women (49.8%) had their first menstruation (menarche) at 12–13 years of age. The distribution of menopausal status and the prevalence of chronic disease varied considerably among studies. At baseline, most women (57%) were pre- or peri-menopausal, 20% reported a natural menopause (range 0.8–55.6%) and the remainder had surgery or were taking hormones. By the end of follow-up, the prevalence rates of CVD and diabetes were 7.2% (range 0.9–24.6%) and 5.1% (range 1.3–13

  12. Photoacoustic microbeam-oscillator with tunable resonance direction and amplitude

    Science.gov (United States)

    Wu, Qingjun; Li, Fanghao; Wang, Bo; Yi, Futing; Jiang, J. Z.; Zhang, Dongxian

    2018-01-01

    We successfully design one photoacoustic microbeam-oscillator actuated by nanosecond laser, which exhibits tunable resonance direction and amplitude. The mechanism of laser induced oscillation is systematically analyzed. Both simulation and experimental results reveal that the laser induced acoustic wave propagates in a multi-reflected mode, resulting in resonance in the oscillator. This newly-fabricated micrometer-sized beam-oscillator has an excellent actuation function, i.e., by tuning the laser frequency, the direction and amplitude of actuation can be efficiently altered, which will have potential industrial applications.

  13. Evidence for Two Separate but Interlaced Components of the Chromospheric Magnetic Field

    Science.gov (United States)

    Muglach, K.; Reardon, K. P.; Wang, Y.-M.; Warren, H. P.

    2012-01-01

    Chromospheric fibrils are generally thought to trace out horizontal magnetic fields that fan out from flux concentrations in the photosphere. A high-resolution (0.2") image taken in the core of the Ca IJ854.2 nm line shows the dark fibrils within an active region remnant as fine, loop-like features that are aligned parallel to each other and have lengths on the order of a supergranular diameter (approx.30 Mm). Comparison with a line-of-sight magnetogram confirms that the fibrils are centered above intranetwork areas, with one end rooted just inside the neighboring plage or strong unipolar network but the other endpoint less clearly defined. Focusing on a particular arcade-like structure lying entirely on one side of a filament channel (large-scale polarity inversion), we find that the total amount of positive-polarity flux underlying this "fibril arcade' is 50 times greater than the total amount of negative-polarity flux. Thus, if the fibrils represent closed loops, they must consist of very weak fields (in terms of flux density), which are interpenetrated by a more vertical field that contains most of the flux. This surprising result suggests that the fibrils in unipolar regions connect the network to the nearby intranetwork flux, while the bulk of the network flux is diverted upward into the corona and connects to remote regions of the opposite polarity. We conclude that the chromospheric field near the edge of the network has an interlaced structure resembling that in sunspot penumbrae, with the fibrils representing the low-lying horizontal flux that remains trapped within the highly nonpotential chromospheric layer.

  14. An accelerator-based neutron microbeam system for studies of radiation effects.

    Science.gov (United States)

    Xu, Yanping; Randers-Pehrson, Gerhard; Marino, Stephen A; Bigelow, Alan W; Akselrod, Mark S; Sykora, Jeff G; Brenner, David J

    2011-06-01

    A novel neutron microbeam is being developed at the Radiological Research Accelerator Facility (RARAF) of Columbia University. The RARAF microbeam facility has been used for studies of radiation bystander effects in mammalian cells for many years. Now a prototype neutron microbeam is being developed that can be used for bystander effect studies. The neutron microbeam design here is based on the existing charged particle microbeam technology at the RARAF. The principle of the neutron microbeam is to use the proton beam with a micrometre-sized diameter impinging on a very thin lithium fluoride target system. From the kinematics of the ⁷Li(p,n)⁷Be reaction near the threshold of 1.881 MeV, the neutron beam is confined within a narrow, forward solid angle. Calculations show that the neutron spot using a target with a 17-µm thick gold backing foil will be neutron flux will roughly be 2000 per second based on the current beam setup at the RARAF singleton accelerator. The dose rate will be about 200 mGy min⁻¹. The principle of this neutron microbeam system has been preliminarily tested at the RARAF using a collimated proton beam. The imaging of the neutron beam was performed using novel fluorescent nuclear track detector technology based on Mg-doped luminescent aluminum oxide single crystals and confocal laser scanning fluorescent microscopy.

  15. The single-particle microbeam facility at CEA-Saclay

    Energy Technology Data Exchange (ETDEWEB)

    Khodja, H. [DSM/IRAMIS/SIS2M, CEA Saclay, F-91191 Gif-sur-Yvette Cedex (France); CNRS, UMR9956, Laboratoire Pierre Suee, F-91191 Gif-sur-Yvette Cedex (France)], E-mail: hicham.khodja@cea.fr; Hanot, M.; Carriere, M.; Hoarau, J. [DSM/IRAMIS/SIS2M, CEA Saclay, F-91191 Gif-sur-Yvette Cedex (France); CNRS, UMR9956, Laboratoire Pierre Suee, F-91191 Gif-sur-Yvette Cedex (France); Angulo, J.F. [DSV, IRCM, SRO, Laboratoire de Genetique de la Radiosensibilite, F-92265 Fontenay aux Roses (France)

    2009-06-15

    Low dose and non-targeted effect studies continue to attract the attention of a growing number of radiobiologists. Experimental setups based on light ion microbeams constitute a tool of choice for this kind of investigations. However, a careful attention must be given to experimental conditions, as setup-induced stress levels should be well below those induced by the irradiation itself. Here, we present the current status of the single-particle microbeam facility that has been developed these last years at the nuclear microprobe of Saclay. The driving idea was to build a facility in which local irradiation studies are performed in an environment close to cellular biology standards. This facility includes unique features, such as (i) a compact setup that allows easy access and vertical irradiation mode, (ii) a collimated beam that can be mechanically positioned under the desired cells at a very fast speed, avoiding the requirement of a focusing element and (iii) a controlled environment (temperature, CO{sub 2}, humidity) that allows performing of very long term experiments on cultured cells. Fluorescent techniques are implemented and permit in situ monitoring of cellular responses to irradiations. Several radiobiological studies are already underway and this will be illustrated with recent results regarding DNA damage and reactive oxygen species signaling time courses following targeted irradiations.

  16. An Experimental and Theoretical Investigation of Electrostatically Coupled Cantilever Microbeams

    KAUST Repository

    Ilyas, Saad

    2016-06-16

    We present an experimental and theoretical investigation of the static and dynamic behavior of electrostatically coupled laterally actuated silicon microbeams. The coupled beam resonators are composed of two almost identical flexible cantilever beams forming the two sides of a capacitor. The experimental and theoretical analysis of the coupled system is carried out and compared against the results of beams actuated with fixed electrodes individually. The pull-in characteristics of the electrostatically coupled beams are studied, including the pull-in time. The dynamics of the coupled dual beams are explored via frequency sweeps around the neighborhood of the natural frequencies of the system for different input voltages. Good agreement is reported among the simulation results and the experimental data. The results show considerable drop in the pull-in values as compared to single microbeam resonators. The dynamics of the coupled beam resonators are demonstrated as a way to increase the bandwidth of the resonator near primary resonance as well as a way to introduce increased frequency shift, which can be promising for resonant sensing applications. Moreover the dynamic pull-in characteristics are also studied and proposed as a way to sense the shift in resonance frequency.

  17. Parameter identification of an electrically actuated imperfect microbeam

    KAUST Repository

    Ruzziconi, Laura

    2013-12-01

    In this study we consider a microelectromechanical system (MEMS) and focus on extracting analytically the model parameters that describe its non-linear dynamic features accurately. The device consists of a clamped-clamped polysilicon microbeam electrostatically and electrodynamically actuated. The microbeam has imperfections in the geometry, which are related to the microfabrication process, resulting in many unknown and uncertain parameters of the device. The objective of the present paper is to introduce a simple but appropriate model which, despite the inevitable approximations, is able to describe and predict the most relevant aspects of the experimental response in a neighborhood of the first symmetric resonance. The modeling includes the main imperfections in the microstructure. The unknown parameters are settled via parametric identification. The approach is developed in the frequency domain and is based on matching both the frequency values and, remarkably, the frequency response curves, which are considered as the most salient features of the device response. Non-linearities and imperfections considerably complicate the identification process. Via the combined use of linear analysis and non-linear dynamic simulations, a single first symmetric mode reduced-order model is derived. Extensive numerical simulations are performed at increasing values of electrodynamic excitation. Comparison with experimental data shows a satisfactory concurrence of results not only at low electrodynamic voltage, but also at higher ones. This validates the proposed theoretical approach. We highlight its applicability, both in similar case-studies and, more in general, in systems. © 2013 Elsevier Ltd.

  18. 7th International Workshop on Microbeam Probes of Cellular Radiation Response

    Energy Technology Data Exchange (ETDEWEB)

    Brenner, David J.

    2009-07-21

    The extended abstracts that follow present a summary of the Proceedings of the 7th International Workshop: Microbeam Probes of Cellular Radiation Response, held at Columbia University’s Kellogg Center in New York City on March 15–17, 2006. These International Workshops on Microbeam Probes of Cellular Radiation Response have been held regularly since 1993 (1–5). Since the first workshop, there has been a rapid growth (see Fig. 1) in the number of centers developing microbeams for radiobiological research, and worldwide there are currently about 30 microbeams in operation or under development. Single-cell/single-particle microbeam systems can deliver beams of different ionizing radiations with a spatial resolution of a few micrometers down to a few tenths of a micrometer. Microbeams can be used to addressquestions relating to the effects of low doses of radiation (a single radiation track traversing a cell or group of cells), to probe subcellular targets (e.g. nucleus or cytoplasm), and to address questions regarding the propagation of information about DNA damage (for example, the radiation-induced bystander effect). Much of the recent research using microbeams has been to study low-dose effects and ‘‘non-targeted’’ responses such as bystander effects, genomic instability and adaptive responses. This Workshop provided a forum to assess the current state of microbeam technology and current biological applications and to discuss future directions for development, both technological and biological. Over 100 participants reviewed the current state of microbeam research worldwide and reported on new technological developments in the fields of both physics and biology.

  19. Automated microbeam observation environment for biological analysis-Custom portable environmental control applied to a vertical microbeam system.

    Science.gov (United States)

    England, Matthew J; Bigelow, Alan W; Merchant, Michael J; Velliou, Eirini; Welch, David; Brenner, David J; Kirkby, Karen J

    2017-02-01

    Vertical Microbeams (VMB) are used to irradiate individual cells with low MeV energy ions. The irradiation of cells using VMBs requires cells to be removed from an incubator; this can cause physiological changes to cells because of the lower CO 2 concentration, temperature and relative humidity outside of the incubator. Consequently, for experiments where cells require irradiation and observation for extended time periods, it is important to provide a controlled environment. The highly customised nature of the microscopes used on VMB systems means that there are no commercially available environmentally controlled microscope systems for VMB systems. The Automated Microbeam Observation Environment for Biological Analysis (AMOEBA) is a highly flexible modular environmental control system used to create incubator conditions on the end of a VMB. The AMOEBA takes advantage of the recent "maker" movement to create an open source control system that can be easily configured by the user to fit their control needs even beyond VMB applications. When applied to the task of controlling cell medium temperature, CO 2 concentration and relative humidity on VMBs it creates a stable environment that allows cells to multiply on the end of a VMB over a period of 36 h, providing a low-cost (costing less than $2700 to build), customisable alternative to commercial time-lapse microscopy systems. AMOEBA adds the potential of VMBs to explore the long-term effects of radiation on single cells opening up new research areas for VMBs.

  20. Monte Carlo-based treatment planning system calculation engine for microbeam radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Rovira, I.; Sempau, J.; Prezado, Y. [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, Barcelona E-08028 (Spain) and ID17 Biomedical Beamline, European Synchrotron Radiation Facility (ESRF), 6 rue Jules Horowitz B.P. 220, F-38043 Grenoble Cedex (France); Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, Barcelona E-08028 (Spain); Laboratoire Imagerie et modelisation en neurobiologie et cancerologie, UMR8165, Centre National de la Recherche Scientifique (CNRS), Universites Paris 7 et Paris 11, Bat 440., 15 rue Georges Clemenceau, F-91406 Orsay Cedex (France)

    2012-05-15

    Purpose: Microbeam radiation therapy (MRT) is a synchrotron radiotherapy technique that explores the limits of the dose-volume effect. Preclinical studies have shown that MRT irradiations (arrays of 25-75-{mu}m-wide microbeams spaced by 200-400 {mu}m) are able to eradicate highly aggressive animal tumor models while healthy tissue is preserved. These promising results have provided the basis for the forthcoming clinical trials at the ID17 Biomedical Beamline of the European Synchrotron Radiation Facility (ESRF). The first step includes irradiation of pets (cats and dogs) as a milestone before treatment of human patients. Within this context, accurate dose calculations are required. The distinct features of both beam generation and irradiation geometry in MRT with respect to conventional techniques require the development of a specific MRT treatment planning system (TPS). In particular, a Monte Carlo (MC)-based calculation engine for the MRT TPS has been developed in this work. Experimental verification in heterogeneous phantoms and optimization of the computation time have also been performed. Methods: The penelope/penEasy MC code was used to compute dose distributions from a realistic beam source model. Experimental verification was carried out by means of radiochromic films placed within heterogeneous slab-phantoms. Once validation was completed, dose computations in a virtual model of a patient, reconstructed from computed tomography (CT) images, were performed. To this end, decoupling of the CT image voxel grid (a few cubic millimeter volume) to the dose bin grid, which has micrometer dimensions in the transversal direction of the microbeams, was performed. Optimization of the simulation parameters, the use of variance-reduction (VR) techniques, and other methods, such as the parallelization of the simulations, were applied in order to speed up the dose computation. Results: Good agreement between MC simulations and experimental results was achieved, even at

  1. Vibration Characteristics of Piezoelectric Microbeams Based on the Modified Couple Stress Theory

    Directory of Open Access Journals (Sweden)

    R. Ansari

    2014-01-01

    Full Text Available The vibration behavior of piezoelectric microbeams is studied on the basis of the modified couple stress theory. The governing equations of motion and boundary conditions for the Euler-Bernoulli and Timoshenko beam models are derived using Hamilton’s principle. By the exact solution of the governing equations, an expression for natural frequencies of microbeams with simply supported boundary conditions is obtained. Numerical results for both beam models are presented and the effects of piezoelectricity and length scale parameter are illustrated. It is found that the influences of piezoelectricity and size effects are more prominent when the length of microbeams decreases. A comparison between two beam models also reveals that the Euler-Bernoulli beam model tends to overestimate the natural frequencies of microbeams as compared to its Timoshenko counterpart.

  2. Development of a TOF SIMS setup at the Zagreb heavy ion microbeam facility

    Energy Technology Data Exchange (ETDEWEB)

    Tadić, Tonči [Laboratory for Ion Beam Interactions, Ruđer Bošković Institute, Bijenička 54, HR-10000 Zagreb (Croatia); Bogdanović Radović, Iva, E-mail: iva@irb.hr [Laboratory for Ion Beam Interactions, Ruđer Bošković Institute, Bijenička 54, HR-10000 Zagreb (Croatia); Siketić, Zdravko; Cosic, Donny Domagoj; Skukan, Natko; Jakšić, Milko [Laboratory for Ion Beam Interactions, Ruđer Bošković Institute, Bijenička 54, HR-10000 Zagreb (Croatia); Matsuo, Jiro [Quantum Science and Engineering Center, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan)

    2014-08-01

    We describe a new Time-of-flight Secondary Ion Mass Spectrometry (TOF SIMS) setup for MeV SIMS application, which is constructed and installed at the heavy ion microbeam facility at the Ruđer Bošković Institute in Zagreb. The TOF-SIMS setup is developed for high sensitivity molecular imaging using a heavy ion microbeam that focuses ion beams (from C to I) with sub-micron resolution. Dedicated pulse processing electronics for MeV SIMS application have been developed, enabling microbeam-scanning control, incoming ion microbeam pulsing and molecular mapping. The first results showing measured MeV SIMS spectra as well as molecular maps for samples of interest are presented and discussed.

  3. Maximum natural frequencies of polymer composite micro-beams by optimum distribution of carbon nanotubes

    International Nuclear Information System (INIS)

    Rokni, Hossein; Milani, Abbas S.; Seethaler, Rudolf J.

    2011-01-01

    Highlights: → Optimum distributions of MWCNTs within the polymer micro-beams are obtained. → Natural frequencies of nanocomposite beam enhance if its root portion is reinforced with CNTs. → Adding MWCNTs to pure polymer micro-beams has an insignificant effect on mode shapes. → Fundamental frequency value is improved by 12.6-15.9% for various boundary conditions. → New CNT dispersion equations are suggested based on the optimum CNT loading pattern. -- Abstract: Optimum distribution of multi-walled carbon nanotubes (MWCNTs) within a polymer composite micro-beam is sought to achieve its highest natural frequencies given a weight percent (wt.%) of MWCNTs. To this end, the micro-beam is divided into ten segments which are perfectly bonded to their neighbors. Each segment is made of low-viscosity, thermosetting polyester epoxy/amine resin LY-5052 and is reinforced by MWCNTs. A computer program, written in the Python programming language, is compiled with ABAQUS to generate a three-dimensional (3D) finite element (FE) model of the micro-beam and subsequently to evaluate an optimum CNT distribution under various vibration modes and boundary conditions. The influence of uniform and optimum MWCNT distributions on the natural frequencies, mode shapes and equivalent stiffness of the micro-beams is investigated and the results are compared with those of the pure polymer micro-beam. Subsequently, after acquiring the optimum distribution of the MWCNTs, two new CNT dispersion functions are proposed for maximizing fundamental frequencies of the clamped-free and clamped-clamped micro-beams. The results of the FE analysis reveal that the optimal reinforcement distribution pattern significantly depends on vibration mode shapes, particularly the micro-beam curvature under each mode. It is observed that fundamental frequencies of clamped-free, clamped-guided and clamped-clamped micro-beams are enhanced up to 15.9%, 13.1% and 12.6%, respectively, by choosing optimum MWCNT

  4. First trial of spatial and temporal fractionations of the delivered dose using synchrotron microbeam radiation therapy

    International Nuclear Information System (INIS)

    Serduc, Raphael; Braeuer-Krisch, Elke; Bouchet, Audrey; Brochard, Thierry; Bravin, Alberto; Le Duc, Geraldine; Renaud, Luc; Laissue, Jean Albert

    2009-01-01

    The technical feasibility of temporal and spatial fractionations of the radiation dose has been evaluated using synchrotron microbeam radiation therapy for brain tumors in rats. A significant increase in lifespan (216%, p<0.0001) resulted when three fractions of microbeam irradiation were applied to the tumor through three different ports, orthogonal to each other, at 24 h intervals. However, there were no long-term survivors, and immunohistological studies revealed that 9 L tumors were not entirely ablated. (orig.)

  5. Application of microbeam technique for the small-angle diffraction studies of a living tissue

    Energy Technology Data Exchange (ETDEWEB)

    Drakopoulos, M. [ESRF, B.P. 220, 38043 Grenoble, Cedex (France); Sergienko, P.M. [Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino 142290 (Russian Federation)]. E-mail: serg@iteb.ru; Snigireva, I. [ESRF, B.P. 220, 38043 Grenoble, Cedex (France); Snigirev, A. [ESRF, B.P. 220, 38043 Grenoble, Cedex (France); Vazina, A.A. [Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino 142290 (Russian Federation)

    2005-05-01

    X-ray diffraction patterns from a single hair cross-section and from the functionally different submicron fragments of a frog striated skeletal muscle sarcomere were obtained for the first time by using a microbeam on the undulator beam line ID18 of the third-generation European Synchrotron Radiation Facility (ESRF, Grenoble, France). The microbeam technique proves to be a potential tool for studying the local microstructures of various biological objects.

  6. High Resolution Electron Microbeam Examination and 3D Reconstruction of Alligator Gar Scale

    Science.gov (United States)

    2016-06-27

    Distribution Unlimited UU UU UU UU 27-06-2016 15-Nov-2012 14-Nov-2015 Final Report: High Resolution Electron Microbeam Examination and 3D...Resolution Electron Microbeam Examination and 3D reconstruction of Alligator Gar Scale Report Title Engineered laminate composites have been widely used...peer-reviewed journals: Number of Non Peer-Reviewed Conference Proceeding publications (other than abstracts): Peer-Reviewed Conference Proceeding

  7. Microbeam analysis of hydrogen in coked catalyst pellets

    International Nuclear Information System (INIS)

    Sofield, C.J.; Bridwell, L.B.; Wright, C.J.

    1981-01-01

    The hydrogen content of catalyst pellets has recently been shown to be important in predicting the maximum temperature rise of the catalyst during regeneration in industrial plant. This is because carbonaceous coke deposits (CHsub(0.4) to CHsub(2.0)) accumulate in the pellet during use, which then have to be removed by exothermic oxidation. It is important, in this well established industrial process, to limit the maximum temperature that the catalyst reaches to level s sufficiently low to prevent permanent deactivation by sintering. In view of the importance of the H content as a function of the distance from the surface of the catalyst pellets in predicting maximum temperature rises during de-coking, we have adopted the technique of elastic recoil analysis for use with the Harwell microbeam to obtain measurements of the hydrogen concentration at varying positions along a pellet diameter. The method of analysis is described and illustrated with typical data. (orig.)

  8. Microbeam analysis of hydrogen in coked catalyst pellets

    Science.gov (United States)

    Sofield, C. J.; Bridwell, L. B.; Wright, C. J.

    1981-12-01

    The hydrogen content of catalyst pellets has recently been shown to be important in predicting the maximum temperature rise of the catalyst during regeneration in industrial plant. This is because carbonaceous coke deposits (CH 0.4 to CH 2.0) accumulate in the pellet during use, which then have to be removed by exothermic oxidation. It is important, in this well established industrial process, to limit the maximum temperature that the catalyst reaches to level s sufficiently low to prevent permanent deactivation by sintering. In view of the importance of the H content as a function of the distance from the surface of the catalyst pellets in predicting maximum temperature rises during de-coking, we have adopted the technique of elastic recoil analysis for use with the Harwell microbeam to obtain measurements of the hydrogen concentration at varying positions along a pellet diameter. The method of analysis is described and illustrated with typical data.

  9. Nuclear microbeam study of advanced materials for fusion reactor technology

    International Nuclear Information System (INIS)

    Alves, L.C.; Alves, E.; Grime, G.W.; Silva, M.F. da; Soares, J.C.

    1999-01-01

    The Oxford scanning proton microprobe was used to study SiC fibres, SiC/SiC ceramic composites and Be pebbles, which are some of the most important materials for fusion technology. For the SiC materials, although the results reveal a high degree of homogeneity and purity in the composition of the fibres, some grains containing heavy metals were detected in the composites. Rutherford backscattering analysis further allowed establishing that at least some of these grains are not on the surface of the material but rather distributed throughout the bulk of the SiC composites. The two different types of Be pebbles analysed also showed very different levels of contaminants. The information obtained with the microbeam analysis is confronted with the one resulting from the broad beam PIXE and RBS analysis

  10. Electrothermally actuated tunable clamped-guided resonant microbeams

    KAUST Repository

    Alcheikh, Nouha

    2017-06-11

    We present simulation and experimental investigation demonstrating active alteration of the resonant and frequency response behavior of resonators by controlling the electrothermal actuation method on their anchors. In-plane clamped-guided arch and straight microbeams resonators are designed and fabricated with V-shaped electrothermal actuators on their anchors. These anchors not only offer various electrothermal actuation options, but also serve as various mechanical stiffness elements that affect the operating resonance frequency of the structures. We have shown that for an arch, the first mode resonance frequency can be increased up to 50% of its initial value. For a straight beam, we have shown that before buckling, the resonance frequency decreases to very low values and after buckling, it increases up to twice of its initial value. These results can be promising for the realization of different wide–range tunable microresonator. The experimental results have been compared to multi-physics finite-element simulations showing good agreement among them.

  11. Laser ion source development for the Columbia University microbeam

    Science.gov (United States)

    Bigelow, A. W.; Randers-Pehrson, G.; Brenner, D. J.

    2002-02-01

    A design is given of a laser ion source for the 4.2 MV Van de Graaff accelerator at the Columbia University Radiological Research Accelerator Facility (RARAF). The source has been designed with application in mind for the RARAF single-particle single-cell microbeam, though it will also be used for broad-beam irradiations. The operating principle, laser ablation, can produce heavy ions with high charge states so that their energies will be high enough to provide sufficient range—at least 20 μm—for irradiating cells on a thin surface at atmospheric pressure. The laser ion source being implemented at RARAF is based on the laser operated ion source used by Hughes at the University of Arkansas and consists of three main components: laser generator, source vacuum chamber, and spherical electrostatic analyzer.

  12. Microbeam High Angular Resolution Diffraction Applied to Optoelectronic Devices

    International Nuclear Information System (INIS)

    Kazimirov, A.; Bilderback, D. H.; Sirenko, A. A.; Cai, Z.-H.; Lai, B.

    2007-01-01

    Collimating perfect crystal optics in a combination with the X-ray focusing optics has been applied to perform high angular resolution microbeam diffraction and scattering experiments on micron-size optoelectronic devices produced by modern semiconductor technology. At CHESS, we used capillary optics and perfect Si/Ge crystal(s) arrangement to perform X-ray standing waves, high angular-resolution diffraction and high resolution reciprocal space mapping analysis. At the APS, 2ID-D microscope beamline, we employed a phase zone plate producing a beam with the size of 240 nm in the horizontal plane and 350 nm in the vertical (diffraction) plane and a perfect Si (004) analyzer crystal to perform diffraction analysis of selectively grown InGaAsP and InGaAlAs-based waveguides with arc sec angular resolution

  13. Precision Pb and S isotopic ratio measurements by microbeam AMS

    International Nuclear Information System (INIS)

    Sie, S.H.; Sims, D.A.; Bruhn, F.; Suter, G.F.; Cripps, G.; Niklaus, T.R.

    1999-01-01

    The AUSTRALIS (AMS for Ultra Sensitive TRAce eLement and Isotopic Studies) system recently commissioned at CSIRO is a microbeam AMS system dedicated to geochemical and geochronological applications. Unlike conventional AMS systems, where detection of rare isotopes is the main objective, AUSTRALIS is designed to perform in-situ microanalysis of stable and radiogenic isotopes with high precision and freedom from mass interference. The required high precision of better than 1 permil for geochronology is comparable to the best results obtained by AMS for the 13 C/ 12 C ratio. This has been achieved thus far only in bulk radiocarbon measurements using the recombinator method or fast bouncing at the injector combined with a multi-Faraday cup detection. The AUSTRALIS microbeam source incorporates a facility for viewing the sample at high magnification, essential for geological applications. The conventional bouncing method is used at the low energy side for sequential isotope switching. In order to achieve the high precision the effect of source and beam transport inst abilities must be minimised. A novel bouncing method has been developed for the high energy side, allowing complete E/q and m/q analysis for all isotopes of interest, that can be driven at a high rate. First results indicated the need to drive the bouncer faster than 150 ms/isotope, which was the limit of software based driver, in order to achieve better than 0.5% precision in isotopic measurements. The breakdown of the accelerator around mid 1998, interrupted the development of a faster, hardware based driver. This resumed after the refurbishment of the accelerator was completed in early 1999. The present paper describes the result of tests of the new driver system

  14. Medical physics aspects of the synchrotron radiation therapies: Microbeam radiation therapy (MRT) and synchrotron stereotactic radiotherapy (SSRT).

    Science.gov (United States)

    Bräuer-Krisch, Elke; Adam, Jean-Francois; Alagoz, Enver; Bartzsch, Stefan; Crosbie, Jeff; DeWagter, Carlos; Dipuglia, Andrew; Donzelli, Mattia; Doran, Simon; Fournier, Pauline; Kalef-Ezra, John; Kock, Angela; Lerch, Michael; McErlean, Ciara; Oelfke, Uwe; Olko, Pawel; Petasecca, Marco; Povoli, Marco; Rosenfeld, Anatoly; Siegbahn, Erik A; Sporea, Dan; Stugu, Bjarne

    2015-09-01

    Stereotactic Synchrotron Radiotherapy (SSRT) and Microbeam Radiation Therapy (MRT) are both novel approaches to treat brain tumor and potentially other tumors using synchrotron radiation. Although the techniques differ by their principles, SSRT and MRT share certain common aspects with the possibility of combining their advantages in the future. For MRT, the technique uses highly collimated, quasi-parallel arrays of X-ray microbeams between 50 and 600 keV. Important features of highly brilliant Synchrotron sources are a very small beam divergence and an extremely high dose rate. The minimal beam divergence allows the insertion of so called Multi Slit Collimators (MSC) to produce spatially fractionated beams of typically ∼25-75 micron-wide microplanar beams separated by wider (100-400 microns center-to-center(ctc)) spaces with a very sharp penumbra. Peak entrance doses of several hundreds of Gy are extremely well tolerated by normal tissues and at the same time provide a higher therapeutic index for various tumor models in rodents. The hypothesis of a selective radio-vulnerability of the tumor vasculature versus normal blood vessels by MRT was recently more solidified. SSRT (Synchrotron Stereotactic Radiotherapy) is based on a local drug uptake of high-Z elements in tumors followed by stereotactic irradiation with 80 keV photons to enhance the dose deposition only within the tumor. With SSRT already in its clinical trial stage at the ESRF, most medical physics problems are already solved and the implemented solutions are briefly described, while the medical physics aspects in MRT will be discussed in more detail in this paper. Copyright © 2015. Published by Elsevier Ltd.

  15. Structure Interlacing and Pore Engineering of Zn2GeO4 Nanofibers for Achieving High Capacity and Rate Capability as an Anode Material of Lithium Ion Batteries.

    Science.gov (United States)

    Wang, Wei; Qin, Jinwen; Cao, Minhua

    2016-01-20

    An interlaced Zn2GeO4 nanofiber network with continuous and interpenetrated mesoporous structure was prepared using a facile electrospinning method followed by a thermal treatment. The mesoporous structure in Zn2GeO4 nanofibers is directly in situ constructed by the decomposition of polyvinylpyrolidone (PVP), while the interlaced nanofiber network is achieved by the mutual fusion of the junctions between nanofibers in higher calcination temperatures. When used as an anode material in lithium ion batteries (LIBs), it exhibits superior lithium storage performance in terms of specific capacity, cycling stability, and rate capability. The pore engineering and the interlaced network structure are believed to be responsible for the excellent lithium storage performance. The pore structure allows for easy diffusion of electrolyte, shortens the pathway of Li(+) transport, and alleviates large volume variation during repeated Li(+) extraction/insertion. Moreover, the interlaced network structure can provide continuous electron/ion pathways and effectively accommodate the strain induced by the volume change during the electrochemical reaction, thus maintaining structural stability and mechanical integrity of electrode materials during lithiation/delithiation process. This strategy in current work offers a new perspective in designing high-performance electrodes for LIBs.

  16. Evaluation of dose-volume metrics for microbeam radiation therapy dose distributions in head phantoms of various sizes using Monte Carlo simulations

    Science.gov (United States)

    Anderson, Danielle; Siegbahn, E. Albert; Fallone, B. Gino; Serduc, Raphael; Warkentin, Brad

    2012-05-01

    This work evaluates four dose-volume metrics applied to microbeam radiation therapy (MRT) using simulated dosimetric data as input. We seek to improve upon the most frequently used MRT metric, the peak-to-valley dose ratio (PVDR), by analyzing MRT dose distributions from a more volumetric perspective. Monte Carlo simulations were used to calculate dose distributions in three cubic head phantoms: a 2 cm mouse head, an 8 cm cat head and a 16 cm dog head. The dose distribution was calculated for a 4 × 4 mm2 microbeam array in each phantom, as well as a 16 × 16 mm2 array in the 8 cm cat head, and a 32 × 32 mm2 array in the 16 cm dog head. Microbeam widths of 25, 50 and 75 µm and center-to-center spacings of 100, 200 and 400 µm were considered. The metrics calculated for each simulation were the conventional PVDR, the peak-to-mean valley dose ratio (PMVDR), the mean dose and the percentage volume below a threshold dose. The PVDR ranged between 3 and 230 for the 2 cm mouse phantom, and between 2 and 186 for the 16 cm dog phantom depending on geometry. The corresponding ranges for the PMVDR were much smaller, being 2-49 (mouse) and 2-46 (dog), and showed a slightly weaker dependence on phantom size and array size. The ratio of the PMVDR to the PVDR varied from 0.21 to 0.79 for the different collimation configurations, indicating a difference between the geometric dependence on outcome that would be predicted by these two metrics. For unidirectional irradiation, the mean lesion dose was 102%, 79% and 42% of the mean skin dose for the 2 cm mouse, 8 cm cat and 16 cm dog head phantoms, respectively. However, the mean lesion dose recovered to 83% of the mean skin dose in the 16 cm dog phantom in intersecting cross-firing regions. The percentage volume below a 10% dose threshold was highly dependent on geometry, with ranges for the different collimation configurations of 2-87% and 33-96% for the 2 cm mouse and 16 cm dog heads, respectively. The results of this study

  17. Evaluation of dose-volume metrics for microbeam radiation therapy dose distributions in head phantoms of various sizes using Monte Carlo simulations

    International Nuclear Information System (INIS)

    Anderson, Danielle; Fallone, B Gino; Warkentin, Brad; Siegbahn, E Albert; Serduc, Raphael

    2012-01-01

    This work evaluates four dose-volume metrics applied to microbeam radiation therapy (MRT) using simulated dosimetric data as input. We seek to improve upon the most frequently used MRT metric, the peak-to-valley dose ratio (PVDR), by analyzing MRT dose distributions from a more volumetric perspective. Monte Carlo simulations were used to calculate dose distributions in three cubic head phantoms: a 2 cm mouse head, an 8 cm cat head and a 16 cm dog head. The dose distribution was calculated for a 4 × 4 mm 2 microbeam array in each phantom, as well as a 16 × 16 mm 2 array in the 8 cm cat head, and a 32 × 32 mm 2 array in the 16 cm dog head. Microbeam widths of 25, 50 and 75 µm and center-to-center spacings of 100, 200 and 400 µm were considered. The metrics calculated for each simulation were the conventional PVDR, the peak-to-mean valley dose ratio (PMVDR), the mean dose and the percentage volume below a threshold dose. The PVDR ranged between 3 and 230 for the 2 cm mouse phantom, and between 2 and 186 for the 16 cm dog phantom depending on geometry. The corresponding ranges for the PMVDR were much smaller, being 2–49 (mouse) and 2–46 (dog), and showed a slightly weaker dependence on phantom size and array size. The ratio of the PMVDR to the PVDR varied from 0.21 to 0.79 for the different collimation configurations, indicating a difference between the geometric dependence on outcome that would be predicted by these two metrics. For unidirectional irradiation, the mean lesion dose was 102%, 79% and 42% of the mean skin dose for the 2 cm mouse, 8 cm cat and 16 cm dog head phantoms, respectively. However, the mean lesion dose recovered to 83% of the mean skin dose in the 16 cm dog phantom in intersecting cross-firing regions. The percentage volume below a 10% dose threshold was highly dependent on geometry, with ranges for the different collimation configurations of 2–87% and 33–96% for the 2 cm mouse and 16 cm dog heads, respectively. The results of this

  18. Bystander effect studies using heavy-ion microbeam

    International Nuclear Information System (INIS)

    Kobayashi, Yasuhiko; Funayama, Tomoo; Sakashita, Tetsuya; Wada, Seiichi; Yokota, Yuichiro; Kakizaki, Takehiko; Hamada, Nobuyuki; Hara, Takamitsu; Fukamoto, Kana; Suzuki, Michiyo; Ni, M.; Furusawa, Yoshiya

    2007-01-01

    We have established a single cell irradiation system, which allows selected cells to be individually hit with defined number of heavy charged particles, using a collimated heavy-ion microbeam apparatus at JAEA-Takasaki. This system has been developed to study radiobiological processes in hit cells and bystander cells exposed to low dose and low dose-rate high-LET radiations, in ways that cannot be achieved using conventional broad-field exposures. Individual cultured cells grown in special dishes were irradiated in the atmosphere with a single or defined numbers of 18.3 MeV/amu 12 C, 13.0 or 17.5 MeV/amu 20 Ne, and 11.5 MeV/amu 40 Ar ions. Targeting and irradiation of the cells were performed automatically according to the positional data of the target cells microscopically obtained before irradiation. The actual number of particle tracks that pass through target cells was detected with prompt etching of the bottom of the cell dish made of ion track detector TNF-1 (modified CR-39). (author)

  19. Dynamics of an Imperfect Microbeam Considering its Exact Shape

    KAUST Repository

    Bataineh, Ahmad M.

    2014-08-17

    We study the static and dynamic behavior of electrically actuated micromachined arches. First, we conduct experiments on micromachined polysilicon beams by driving them electrically and varying their amplitude and frequency of voltage loads. The results reveal several interesting nonlinear phenomena of jumps, hysteresis, and softening behaviors. Next, we conduct analytical and theoretical investigation to understand the experiments. First, we solve the Eigen value problem analytically. We study the effect of the initial rise on the natural frequency and mode shapes, and use a Galerkin-based procedure to derive a reduced order model, which is then used to solve both the static and dynamic responses. We use two symmetric modes in the reduced order model to have accurate and converged results. We use long time integration to solve the nonlinear ordinary differential equations, and then modify our model using effective length to match experimental results. To further improve the matching with the experimental data, we curve-fit the exact profile of the microbeam to match the experimentally measured profile and use it in the reduced-order model to generate frequency-response curves. Finally, we use another numerical technique, the shooting technique, to solve the nonlinear ordinary differential equations. By using shooting and the curve fitted function, we found that we get good agreement with the experimental data.

  20. A new external microbeam system in Fudan University

    International Nuclear Information System (INIS)

    Zheng, Y.; Shen, H.; Li, Y.Q.; Li, X.Y.; Yang, M.J.; Mi, Y.

    2013-01-01

    A cost-effective and removable external beam system is set up based on the Oxford Microbeam system in Fudan University. In our external beam system, 7.5-μm-thick Kapton film is used as exit window with a diameter of 3.5 mm. The spatial resolution is about 18 μm full width at half maximum (FWHM) on a copper grid. As an example, calcium distribution in otolith is present by the external micro-PIXE. In addition, little change can be done to the external system mentioned above for radiobiology experiments. The exit window can be changed from the focal plane to the observation window of vacuum chamber. By calculation, the beam spot size can reach less than 30 μm. Since the Oxford type octagonal target chamber is popular among the nuclear microprobe facilities, this method can be provided to easily replace the in-vacuum system with the external system, extending the in-vacuum analysis to external beam analysis

  1. A new external microbeam system in Fudan University

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Y.; Shen, H., E-mail: haoshen@fudan.edu.cn; Li, Y.Q.; Li, X.Y.; Yang, M.J.; Mi, Y.

    2013-07-01

    A cost-effective and removable external beam system is set up based on the Oxford Microbeam system in Fudan University. In our external beam system, 7.5-μm-thick Kapton film is used as exit window with a diameter of 3.5 mm. The spatial resolution is about 18 μm full width at half maximum (FWHM) on a copper grid. As an example, calcium distribution in otolith is present by the external micro-PIXE. In addition, little change can be done to the external system mentioned above for radiobiology experiments. The exit window can be changed from the focal plane to the observation window of vacuum chamber. By calculation, the beam spot size can reach less than 30 μm. Since the Oxford type octagonal target chamber is popular among the nuclear microprobe facilities, this method can be provided to easily replace the in-vacuum system with the external system, extending the in-vacuum analysis to external beam analysis.

  2. A new external microbeam system in Fudan University

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Y. [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Shen, H., E-mail: haoshen@fudan.edu.cn [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Li, Y.Q.; Li, X.Y.; Yang, M.J.; Mi, Y. [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China)

    2013-02-01

    A cost-effective and removable external beam system is set up based on the Oxford Microbeam system in Fudan University. In our external beam system, 7.5-μm-thick Kapton film is used as exit window with a diameter of 3.5 mm. The spatial resolution is about 18 μm full width at half maximum (FWHM) on a copper grid. As an example, calcium distribution in otolith is present by the external micro-PIXE. In addition, little change can be done to the external system mentioned above for radiobiology experiments. The exit window can be changed from the focal plane to the observation window of vacuum chamber. By calculation, the beam spot size can reach less than 30 μm. Since the Oxford type octagonal target chamber is popular among the nuclear microprobe facilities, this method can be provided to easily replace the in-vacuum system with the external system, extending the in-vacuum analysis to external beam analysis.

  3. Development of the Jyväskylä microbeam facility

    Science.gov (United States)

    Norarat, Rattanaporn; Sajavaara, Timo; Laitinen, Mikko; Heikkinen, Pauli; Ranttila, Kimmo; Ylikorkala, Kari; Hänninen, Väinö; Rossi, Mikko; Jones, Pete; Marjomäki, Varpu; Gilbert, Leona; Whitlow, Harry J.

    2012-02-01

    A new microbeam facility is being constructed at the 1.7 MV Pelletron Accelerator in Jyväskylä. The facility is designed for easy upgrading and incorporates a number of innovative features. Initially, it is based on a Heidelberg doublet with a design capability of a 3 × 5 μm beamspot at PIXE intensities and later upgraded to nanobeam performance. A thermal-expansion compensated rigid frame mounted on a mechanically isolated floor section is used to support the ion optical components. A compact-post focusing electrostatic deflector is used for high linearity beam scanning. This together with a novel time-stamped data collection (TDC) allows dynamic effects in IBIC, fluorescence bleaching to be studied as well as facilitating multi-resolution image support for low-fluence imaging of cells. The target chamber is fitted with a novel low-cost large working distance optical microscope, extremely compact large solid angle photon detectors as well as conventional secondary electron, PIXE and Scanning Transmission Ion Microscopy (STIM) detectors.

  4. Development of a Charged Particle Microbeam for Single-Particle Subcellular Irradiations at the MIT Laboratory for Accelerator Beam Application

    International Nuclear Information System (INIS)

    Yanch, Jacquelyn C.

    2004-01-01

    The development of a charged particle microbeam for single particle, subcellular irradiations at the Massachusetts Institute of Technology Laboratory for Accelerator Beam Applications (MIT LABA) was initiated under this NEER aeard. The Microbeam apparatus makes use of a pre-existing electrostatic accelerator with a horizontal beam tube

  5. Construction of a 300-keV compact ion microbeam system with a three-stage acceleration lens

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Yasuyuki, E-mail: ishii.yasuyuki@jaea.go.jp; Ohkubo, Takeru; Kojima, Takuji; Kamiya, Tomihiro

    2014-08-01

    Hydrogen ion microbeams were experimentally formed at beam energies below 150 keV using a 300-keV compact microbeam system that was constructed at the Japan Atomic Energy Agency. This paper is a preliminary report on the performance of the three-stage acceleration lens used in the compact microbeam system. This system consists of a three-stage acceleration lens and a plasma-type ion source. Since the three-stage acceleration lens was designed to simultaneously accelerate and focus the ion beam, the compact microbeam system is only about 1-m high and can be placed in a small experimental room. To evaluate the effectiveness of the three-stage acceleration lens, experimentally measured beam sizes are compared with theoretically calculated ones. The calculated and measured beam sizes were consistent within 10%. This shows that the three-stage acceleration lens is effective as a focusing lens for forming microbeams.

  6. Ion microbeam irradiation for radiobiology and radical chemistry: status and prospect

    Energy Technology Data Exchange (ETDEWEB)

    Khodja, H, E-mail: hicham.khodja@cea.fr [CEA, IRAMIS, SIS2M, LEEL, 91191 Gif-sur-Yvette (France); CNRS, UMR 3299, SIS2M, LEEL, 91191 Gif-sur-Yvette (France)

    2011-01-01

    Ion microbeams are commonly used to study local irradiation effects in living cells, as it has been established that ion beam irradiations can lead to deleterious changes in cells that are not struck directly by the microbeam. Such changes, which take place over distances long compared to the size of the irradiation spot and for times long compared to the time of irradiation, are collectively termed radiation-induced bystander effect or RIBE. Free-radical chemistry is frequently invoked to explain the RIBE but no unified model is available at present. Ion microbeams when coupled with advanced methods for observing free radicals are the tools of choice for investigating the chemistry and biological processes governing RIBE.

  7. Multifrequency excitation of a clamped–clamped microbeam: Analytical and experimental investigation

    KAUST Repository

    Jaber, Nizar

    2016-03-14

    Using partial electrodes and a multifrequency electrical source, we present a large-bandwidth, large-amplitude clamped–clamped microbeam resonator excited near the higher order modes of vibration. We analytically and experimentally investigate the nonlinear dynamics of the microbeam under a two-source harmonic excitation. The first-frequency source is swept around the first three modes of vibration, whereas the second source frequency remains fixed. New additive and subtractive resonances are demonstrated. We illustrated that by properly tuning the frequency and amplitude of the excitation force, the frequency bandwidth of the resonator is controlled. The microbeam is fabricated using polyimide as a structural layer coated with nickel from the top and chromium and gold layers from the bottom. Using the Galerkin method, a reduced order model is derived to simulate the static and dynamic response of the device. A good agreement between the theoretical and experimental data are reported.

  8. High-resolution X-ray scattering topography using synchrotron radiation microbeam

    International Nuclear Information System (INIS)

    Chikaura, Yoshinori; Suzuki, Yoshifumi; Kii, Hideki

    1994-01-01

    Although spatial resolution is the most essential factor determining the function of X-ray topography, it has not been improved in 30 years in spite of increasing requirements for highly-resolvable topography in materials science. X-ray scattering topography using a microbeam is a method capable of overcoming this resolution problem. Because the maximum resolution of an apparatus using a sealed-off tube is limited to 20μm, we designed and constructed scattering topography equipment using a synchrotron radiation microbeam. In the experiment, the slit system forms the microbeam 7 μm in diameter. We observed a cellulose distribution in bamboo as a testing material. When the scanning step was 2 μm, we attained spatial resolution less than 5 μm. (author)

  9. Improved spatial resolution by MOSFET dosimetry of an x-ray microbeam.

    Science.gov (United States)

    Kaplan, G I; Rosenfeld, A B; Allen, B J; Booth, J T; Carolan, M G; Holmes-Siedle, A

    2000-01-01

    Measurement of the lateral profile of the dose distribution across a narrow x-ray microbeam requires a dosimeter with a micron resolution. We investigated the use of a MOSFET dosimeter in an "edge-on" orientation with the gate insulating oxide layer parallel to the direction of the beam. We compared results using this technique to Gafchromic film measurements of a 200 micrometer wide planar x-ray microbeam. The microbeam was obtained by using a vernier micrometer-driven miniature collimator attached to a Therapax DXT300 x-ray machine operated at 100 kVp. The "edge-on" application allows utilization of the ultra thin sensitive volume of the MOSFET detector. Spatial resolution of both the MOSFET and Gafchromic film dosimeters appeared to be of about 1 micrometer. The MOSFET dosimeter appeared to provide more uniform dose profiles with the advantage of on-line measurements.

  10. Microbeam high-resolution diffraction and x-ray standing wave methods applied to semiconductor structures

    International Nuclear Information System (INIS)

    Kazimirov, A; Bilderback, D H; Huang, R; Sirenko, A; Ougazzaden, A

    2004-01-01

    A new approach to conditioning x-ray microbeams for high angular resolution x-ray diffraction and scattering techniques is introduced. We combined focusing optics (one-bounce imaging capillary) and post-focusing collimating optics (miniature Si(004) channel-cut crystal) to generate an x-ray microbeam with a size of 10 μm and ultimate angular resolution of 14 μrad. The microbeam was used to analyse the strain in sub-micron thick InGaAsP epitaxial layers grown on an InP(100) substrate by the selective area growth technique in narrow openings between the oxide stripes. For the structures for which the diffraction peaks from the substrate and the film overlap, the x-ray standing wave technique was applied for precise measurements of the strain with a Δd/d resolution of better than 10 -4 . (rapid communication)

  11. Development of micromachining technology in ion microbeam system at TIARA, JAEA

    International Nuclear Information System (INIS)

    Kamiya, T.; Nishikawa, H.; Satoh, T.; Haga, J.; Oikawa, M.; Ishii, Y.; Ohkubo, T.; Uchiya, N.; Furuta, Y.

    2009-01-01

    An ion-beam-lithography technique has been progressed in the microbeam systems at Japan Atomic Energy Agency (JAEA) Takasaki. In order to obtain a high-precision measure for microbeam size estimation with a high precision, we applied this technique combined with the electroplating process to make a Ni relief pattern as a resolution standard used in secondary electron imaging. As a result, the smallest beam size could be recorded. The scattering of ions in the materials influenced the spatial resolution and this is also discussed

  12. Synchrotron x-ray microbeam characteristics for x-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Iida, Atsuo; Noma, Takashi

    1995-01-01

    X-ray fluorescence analysis using a synchrotron x-ray microprobe has become an indispensable technique for non-destructive micro-analysis. One of the most important parameters that characterize the x-ray microbeam system for x-ray fluorescence analysis is the beam size. For practical analysis, however, the photon flux, the energy resolution and the available energy range are also crucial. Three types of x-ray microbeam systems, including monochromatic and continuum excitation systems, were compared with reference to the sensitivity, the minimum detection limit and the applicability to various types of x-ray spectroscopic analysis. 16 refs., 5 figs

  13. Study of a 3D diamond detector with photon and proton micro-beams

    OpenAIRE

    Forcolin, Giulio; Grilj, V.; Hamilton, Bruce; Li, Lin; Mcgowan, Malachy; Murphy, S. A.; Oh, Alexander; Skukan, N.; Whitehead, David; Zadoroshnyj, Andrij

    2016-01-01

    To form a 3D diamond detector electrodes were produced in diamond by a femtosecond laser-induced phase transition of diamond to graphite. The process parameters were varied to study the influence on electrode resistivity and induced stress. A technique for a relative measurement of stress induced in 3D diamond detectors is described. The detector was characterised with a 15 keV photon micro-beam (Diamond Light Source, Oxford) and a 4 MeV proton micro-beam (Ruder Bošković Institute, Zagreb). T...

  14. Real time monitoring of electronic materials and devices using microbeams

    International Nuclear Information System (INIS)

    Manfredotti, C.

    2002-01-01

    IBIC and IBIL techniques with proton microbeams of diameter of the order of 1 μm and of energy in the interval 2 MeV-6 MeV have been used in different configurations and geometries in order to characterize frontier semiconducting or insulating materials like GaAs and CVD diamond, or more traditional materials like Si, by looking at space distribution of important transport parameters like drift and diffusion lengths. By applying lateral IBIC in GaAs Schottky diodes it had been possible to follow directly the widening of depletion region as a function of bias voltage, while for Si drift/diffusion structures a particular code has been developed in order to measure directly the diffusion length and lifetime of minority carriers. In CVD diamond both IBIC and IBIL measurements have been performed in frontal and lateral geometries. The main results are represented by the correlation between IBIC maps and morphology of the grains, with the conclusion that collection length is limited by the grain dimensions, by the proof of the validity of the linear model, by the clarification of the spatial behaviour of the 'primed' or irradiated state in terms of homogenization and improvement of charge collection length and, finally, by the observation of a quasi-complementarity in space between IBIC and IBIL maps, with the conclusion that in CVD diamond the recombination is mainly radiative. Moreover, concerning nitrogen content, a method has been proposed in order to forecast the detector quality of CVD diamond from IBIL spectra. (author)

  15. Nonlinear dynamic response of an electrically actuated imperfect microbeam resonator

    KAUST Repository

    Ruzziconi, Laura

    2013-08-04

    We present a study of the dynamic behavior of a MEMS device constituted of an imperfect clamped-clamped microbeam subjected to electrostatic and electrodynamic actuation. Our objective is to develop a theoretical analysis, which is able to describe and predict all the main relevant aspects of the experimental response. Extensive experimental investigation is conducted, where the main imperfections coming from microfabrication are detected and the nonlinear dynamics are explored at increasing values of electrodynamic excitation, in a neighborhood of the first symmetric resonance. The nonlinear behavior is highlighted, which includes ranges of multistability, where the non-resonant and the resonant branch coexist, and intervals where superharmonic resonances are clearly visible. Numerical simulations are performed. Initially, two single mode reduced-order models are considered. One is generated via the Galerkin technique, and the other one via the combined use of the Ritz method and the Padé approximation. Both of them are able to provide a satisfactory agreement with the experimental data. This occurs not only at low values of electrodynamic excitation, but also at higher ones. Their computational efficiency is discussed in detail, since this is an essential aspect for systematic local and global simulations. Finally, the theoretical analysis is further improved and a two-degree-of-freedom reduced-order model is developed, which is capable also to capture the measured second symmetric superharmonic resonance. Despite the apparent simplicity, it is shown that all the proposed reduced-order models are able to describe the experimental complex nonlinear dynamics of the device accurately and properly, which validates the proposed theoretical approach. Copyright © 2013 by ASME.

  16. Laser microbeam manipulation of cell morphogenesis growing in fungal hyphae

    Science.gov (United States)

    Bracker, Charles E.; Murphy, Douglas J.; Lopez-Franco, Rosamaria

    1997-05-01

    Laser microbeam irradiation at 820 nm predictably and reproducibly altered morphogenetic patterns in fungal cells. Optical tweezers were highly effective as localized, noninvasive, and largely nondestructive probes under precise spatial and temporal control. In growing hyphae, the position of the Spitzenkorper (a multicomponent complex containing mainly secretory vesicles in the hyphal apex), is correlated with the site of maximum cell expansion during tip growth. The Spitzenkorper was not trapped by the laser, but moved away from the trap, and could be `chased' around the cell by the laser beam. Consequently, the direction of cell elongation was readily changed by moving the Spitzenkorper. When the laser was held steady at the cytoplasmic surface immediately beside the Spitzenkorper, an adventitious branch hypha was initiated on the same side of the hypha, suggesting that unilateral disturbance of vesicle traffic initiated a new lateral Spitzenkorper and hyphal branch near the original hyphal apex. If moving vesicles were trapped by the laser beam and transported to a different area of the cytoplasm near the cell surface, the cell profile bulged where the vesicles were newly concentrated. Variations in the mode of vesicle transfer caused: (1) single and multiple bulges, (2) adventitious branch hyphae, (3) increased cell diameter, and (4) changing directions of hyphal elongation. Thus, laser tweezers emerge as a powerful tool for controlling patterns of cell morphogenesis. The findings strongly support the hypothesis that sites of vesicle concentration and release to the cell surface are important determinants of cell morphogenesis in fungi. This conclusion lends support to the basic premises of a modern mathematical model of hyphal tip growth (the hyphoid/VSC model) but does not in itself provide the information needed for a comprehensive and integrated explanation of the mechanism of cell growth in fungi.

  17. A multicentre audit of HDR/PDR brachytherapy absolute dosimetry in association with the INTERLACE trial (NCT015662405)

    Science.gov (United States)

    Díez, P.; Aird, E. G. A.; Sander, T.; Gouldstone, C. A.; Sharpe, P. H. G.; Lee, C. D.; Lowe, G.; Thomas, R. A. S.; Simnor, T.; Bownes, P.; Bidmead, M.; Gandon, L.; Eaton, D.; Palmer, A. L.

    2017-12-01

    A UK multicentre audit to evaluate HDR and PDR brachytherapy has been performed using alanine absolute dosimetry. This is the first national UK audit performing an absolute dose measurement at a clinically relevant distance (20 mm) from the source. It was performed in both INTERLACE (a phase III multicentre trial in cervical cancer) and non-INTERLACE brachytherapy centres treating gynaecological tumours. Forty-seven UK centres (including the National Physical Laboratory) were visited. A simulated line source was generated within each centre’s treatment planning system and dwell times calculated to deliver 10 Gy at 20 mm from the midpoint of the central dwell (representative of Point A of the Manchester system). The line source was delivered in a water-equivalent plastic phantom (Barts Solid Water) encased in blocks of PMMA (polymethyl methacrylate) and charge measured with an ion chamber at 3 positions (120° apart, 20 mm from the source). Absorbed dose was then measured with alanine at the same positions and averaged to reduce source positional uncertainties. Charge was also measured at 50 mm from the source (representative of Point B of the Manchester system). Source types included 46 HDR and PDR 192Ir sources, (7 Flexisource, 24 mHDR-v2, 12 GammaMed HDR Plus, 2 GammaMed PDR Plus, 1 VS2000) and 1 HDR 60Co source, (Co0.A86). Alanine measurements when compared to the centres’ calculated dose showed a mean difference (±SD) of  +1.1% (±1.4%) at 20 mm. Differences were also observed between source types and dose calculation algorithm. Ion chamber measurements demonstrated significant discrepancies between the three holes mainly due to positional variation of the source within the catheter (0.4%-4.9% maximum difference between two holes). This comprehensive audit of absolute dose to water from a simulated line source showed all centres could deliver the prescribed dose to within 5% maximum difference between measurement and calculation.

  18. Influence of squeeze film damping on the higher-order modes of clamped–clamped microbeams

    KAUST Repository

    Alcheikh, Nouha

    2016-05-06

    This paper presents an experimental study and a finite-element analysis of the effect of squeeze film damping on the resonance frequency and quality factor of the higher-order flexure vibrations modes of clamped-clamped microbeams. Viscoelastic and silicon nitride microbeams are fabricated and are electrostatically actuated by various electrode configurations to trigger the first, second, and third modes. The damping characteristic and the resonance frequency of these modes are examined for a wide range of gas pressure and electrostatic voltage loads. The results of the silicon nitride beams and viscoelastic beams are compared. It is found that the intrinsic material loss is the major dissipation mechanism at low pressure for the viscoelastic microbeams, significantly limiting their quality factor. It is also found that while the silicon nitride beams show higher quality factors at the intrinsic and molecular regimes of pressure, due to their low intrinsic loss, their quality factors near atmospheric pressure are lower than those of the viscoelastic microbeams. Further, the higher-order modes of all the beams show much higher quality factors at atmospheric pressure compared to the first mode, which could be promising for operating such resonators in air. Experimental results and finite element model simulations show good agreement for resonance frequency and quality factor for the three studied modes. © 2016 IOP Publishing Ltd.

  19. Identification of ancient textile fibres from Khirbet Qumran caves using synchrotron radiation microbeam diffraction

    International Nuclear Information System (INIS)

    Mueller, Martin; Murphy, Bridget; Burghammer, Manfred; Riekel, Christian; Roberts, Mark; Papiz, Miroslav; Clarke, David; Gunneweg, Jan; Pantos, Emmanuel

    2004-01-01

    Archaeological textiles fragments from the caves of Qumran in the Dead Sea region were investigated by means of X-ray microbeam diffraction on single fibres. This non-destructive technique made the identification of the used plant textile fibres possible. Apart from bast fibres (mainly flax), cotton was identified which was most unexpected in the archaeological context

  20. The Dynamics of a Doubly Clamped Microbeam Near the Primary Resonance: Experimental and Analytical Investigation

    KAUST Repository

    Masri, Karim M.

    2016-01-20

    We present experimental and analytical investigation of the dynamics of a doubly clamped microbeam near its primary resonance. The microbeam is excited electrostatically by an electrode on the first half of the beam. These microbeams are fabricated using polyimide as structural layer coated with nickel from top and chromium and gold layers from bottom. A noise signal is applied to experimentally detect the natural frequencies. Then, frequency sweep tests are generated for various values of DC bias revealing hardening, transition, and softening behavior of the microbeam. We report for the first time the transition from lower stable state, to unstable state, and then to large stable state experimentally. A multi-mode Galerkin method is used to develop a reduced order model (ROM) of the beam. Shooting method is used to find the periodic motion and is utilized to generate frequency response curves. The curves show good agreement with the experimental results with hardening behavior at lower DC voltage then softening at higher voltage loads and dynamic pull-in. © Copyright 2015 by ASME.

  1. Continuation of mitosis after selective laser microbeam destruction of the centriolar region

    International Nuclear Information System (INIS)

    Berns, N.W.; Richardson, S.M.

    1977-01-01

    The centriole regions of prophase PTK2 cells were irradiated with a laser microbeam. Cells continued through mitosis normally. Ultrastructural analysis revealed either an absence of centrioles or severely damaged centrioles at the irradiated poles. Microtubules appeared to focus into pericentriolar cloud material

  2. Live cell imaging at the Munich ion microbeam SNAKE - a status report.

    Science.gov (United States)

    Drexler, Guido A; Siebenwirth, Christian; Drexler, Sophie E; Girst, Stefanie; Greubel, Christoph; Dollinger, Günther; Friedl, Anna A

    2015-02-18

    Ion microbeams are important tools in radiobiological research. Still, the worldwide number of ion microbeam facilities where biological experiments can be performed is limited. Even fewer facilities combine ion microirradiation with live-cell imaging to allow microscopic observation of cellular response reactions starting very fast after irradiation and continuing for many hours. At SNAKE, the ion microbeam facility at the Munich 14 MV tandem accelerator, a large variety of biological experiments are performed on a regular basis. Here, recent developments and ongoing research projects at the ion microbeam SNAKE are presented with specific emphasis on live-cell imaging experiments. An overview of the technical details of the setup is given, including examples of suitable biological samples. By ion beam focusing to submicrometer beam spot size and single ion detection it is possible to target subcellular structures with defined numbers of ions. Focusing of high numbers of ions to single spots allows studying the influence of high local damage density on recruitment of damage response proteins.

  3. Live cell imaging at the Munich ion microbeam SNAKE – a status report

    International Nuclear Information System (INIS)

    Drexler, Guido A; Siebenwirth, Christian; Drexler, Sophie E; Girst, Stefanie; Greubel, Christoph; Dollinger, Günther; Friedl, Anna A

    2015-01-01

    Ion microbeams are important tools in radiobiological research. Still, the worldwide number of ion microbeam facilities where biological experiments can be performed is limited. Even fewer facilities combine ion microirradiation with live-cell imaging to allow microscopic observation of cellular response reactions starting very fast after irradiation and continuing for many hours. At SNAKE, the ion microbeam facility at the Munich 14 MV tandem accelerator, a large variety of biological experiments are performed on a regular basis. Here, recent developments and ongoing research projects at the ion microbeam SNAKE are presented with specific emphasis on live-cell imaging experiments. An overview of the technical details of the setup is given, including examples of suitable biological samples. By ion beam focusing to submicrometer beam spot size and single ion detection it is possible to target subcellular structures with defined numbers of ions. Focusing of high numbers of ions to single spots allows studying the influence of high local damage density on recruitment of damage response proteins. The online version of this article (doi:10.1186/s13014-015-0350-7) contains supplementary material, which is available to authorized users

  4. Influence of squeeze film damping on the higher-order modes of clamped–clamped microbeams

    International Nuclear Information System (INIS)

    Alcheikh, N; Kosuru, L; Jaber, N; Bellaredj, M; Younis, M I

    2016-01-01

    This paper presents an experimental study and a finite-element analysis of the effect of squeeze film damping on the resonance frequency and quality factor of the higher-order flexure vibrations modes of clamped–clamped microbeams. Viscoelastic and silicon nitride microbeams are fabricated and are electrostatically actuated by various electrode configurations to trigger the first, second, and third modes. The damping characteristic and the resonance frequency of these modes are examined for a wide range of gas pressure and electrostatic voltage loads. The results of the silicon nitride beams and viscoelastic beams are compared. It is found that the intrinsic material loss is the major dissipation mechanism at low pressure for the viscoelastic microbeams, significantly limiting their quality factor. It is also found that while the silicon nitride beams show higher quality factors at the intrinsic and molecular regimes of pressure, due to their low intrinsic loss, their quality factors near atmospheric pressure are lower than those of the viscoelastic microbeams. Further, the higher-order modes of all the beams show much higher quality factors at atmospheric pressure compared to the first mode, which could be promising for operating such resonators in air. Experimental results and finite element model simulations show good agreement for resonance frequency and quality factor for the three studied modes. (paper)

  5. Assessment of mechanical properties of metallic thin-films through micro-beam testing

    Energy Technology Data Exchange (ETDEWEB)

    Trueba, M.; Gonzalez, D.; Elizalde, M.R.; Martínez-Esnaola, J.M. [CEIT and TECNUN (University of Navarra), P. Manuel Lardizabal 15, 20018 San Sebastián (Spain); Hernandez, M.T.; Li, H.; Pantuso, D. [Design Technology Solutions, Intel Corporation, Hillsboro 97124, OR (United States); Ocaña, I., E-mail: iocana@ceit.es [CEIT and TECNUN (University of Navarra), P. Manuel Lardizabal 15, 20018 San Sebastián (Spain)

    2014-11-28

    Microelectronic industry is driven by the continuous miniaturization process conducing to the introduction of materials with better performance. These materials are subjected to stresses mainly due to thermal mismatch, microstructural changes or process integration which can be in the origin of mechanical reliability issues. To study these phenomena and even electromigration a good mechanical characterization of the materials is needed. This work aims at developing tests to assess fracture and elastoplastic behavior of thin Cu films. The tests developed are based on the deflection of microbeams (micromachined using a focused ion beam) using a nanoindenter. Different test geometries for microbeams have been evaluated and quantitative data have been obtained combining experimental results with analytical or numerical models, depending on the property under study. Microbeam response shows a strong dependence on the orientation of the grains close to the fixed end. Grain orientation has been measured by electron backscatter diffraction and the plastic behavior has been modeled by the finite element method using an in-house crystal plasticity subroutine. The effect of film thickness on fracture energy has been determined from tests of notched beams. - Highlights: • Cu microbeams have been machined with a focused ion beam and tested at a TriboIndenter. • Crystal plasticity has been accounted for when modeling constitutive behavior of Cu. • Fracture energy has been calculated using notched microcantilever beams. • Fracture energy decreases with film thickness.

  6. Development of diagnostic method for deep levels in semiconductors using charge induced by heavy ion microbeams

    Energy Technology Data Exchange (ETDEWEB)

    Kada, Wataru [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Kambayashi, Yuya [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Iwamoto, Naoya; Onoda, Shinobu; Makino, Takahiro; Koka, Masashi; Kamiya, Tomihiro [Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Hoshino, Norihiro; Tsuchida, Hidekazu [Central Research Institute of Electric Power Industry, 2-6-1 Nagasaka, Yokosuka, Kanagawa 240-0196 (Japan); Kojima, Kazutoshi [National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan); Hanaizumi, Osamu [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Ohshima, Takeshi, E-mail: ohshima.takeshi20@jaea.go.jp [Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2015-04-01

    Highlights: •Charge Transient Spectroscopy using heavy ion microbeams (HIQTS) was developed. •HIQTS system is connected with 3 MeV Tandem accelerator at JAEA Takasaki. •Defects in 4H Silicon Carbide (SiC) Schottky diodes were evaluated using HIQTS. •6H-SiC pn diodes with partial damaged areas were also evaluated using HIQTS. -- Abstract: In order to study defects that create deep energy levels in semiconductors which act as carrier traps, Charge Transient Spectroscopy using heavy ion microbeams (HIQTS) was developed at JAEA Takasaki. The HIQTS system was connected with the heavy ion microbeam line of the 3 MV Tandem accelerator. Using the HIQTS system, deep levels in 4H-SiC Schottky barrier diodes irradiated with 3 MeV-protons were studied. As a result, a HIQTS peak with an activation energy of 0.73 eV was observed. In addition, local damage in 6H-SiC pn diodes partially irradiated with 12 MeV-O ion microbeams was studied using HIQTS. With increasing 12 MeV-O ion fluence, charge collection efficiency in locally damaged areas decreased and HIQTS signals increased.

  7. Continuation of mitosis after selective laser microbeam destruction of the centriolar region

    Energy Technology Data Exchange (ETDEWEB)

    Berns, N.W.; Richardson, S.M.

    1977-12-01

    The centriole regions of prophase PTK2 cells were irradiated with a laser microbeam. Cells continued through mitosis normally. Ultrastructural analysis revealed either an absence of centrioles or severely damaged centrioles at the irradiated poles. Microtubules appeared to focus into pericentriolar cloud material.

  8. Phase Noise Squeezing Based Parametric Bifurcation Tracking of MIP-Coated Microbeam MEMS Sensor for TNT Explosive Gas Sensing

    Science.gov (United States)

    2014-06-08

    Standard Form 298 (Rev 8/98) Prescribed by ANSI Std. Z39.18 805-893-8133 W911NF-09-D-0001 Conference Proceeding 55012-LS-ICB.688 a. REPORT 14...Based Parametric Bifurcation Tracking of Mip-Coated Microbeam MEMS Sensor for TNT Explosive Gas Sensing See Attached The views, opinions and/or...2050 1 ABSTRACT Phase Noise-Squeezing-Based Parametric Bifurcation Tracking of Mip-Coated Microbeam MEMS Sensor for TNT Explosive Gas Sensing

  9. DNA damage and repair kinetics after microbeam radiation therapy emulation in living cells using monoenergetic synchrotron X-ray microbeams.

    Science.gov (United States)

    Sprung, Carl N; Cholewa, Marian; Usami, Noriko; Kobayashi, Katsumi; Crosbie, Jeffrey C

    2011-07-01

    A novel synchrotron-based approach, known as microbeam radiation therapy (MRT), currently shows considerable promise in increased tumour control and reduced normal tissue damage compared with conventional radiotherapy. Different microbeam widths and separations were investigated using a controlled cell culture system and monoenergetic (5.35 keV) synchrotron X-rays in order to gain further insight into the underlying cellular response to MRT. DNA damage and repair was measured using fluorescent antibodies against phosphorylated histone H2AX, which also allowed us to verify the exact location of the microbeam path. Beam dimensions that reproduced promising MRT strategies were used to identify useful methods to study the underpinnings of MRT. These studies include the investigation of different spatial configurations on bystander effects. γH2AX foci number were robustly induced in directly hit cells and considerable DNA double-strand break repair occurred by 12 h post-10 Gy irradiation; however, many cells had some γH2AX foci at the 12 h time point. γH2AX foci at later time points did not directly correspond with the targeted regions suggesting cell movement or bystander effects as a potential mechanism for MRT effectiveness. Partial irradiation of single nuclei was also investigated and in most cases γH2AX foci were not observed outside the field of irradiation within 1 h after irradiation indicating very little chromatin movement in this time frame. These studies contribute to the understanding of the fundamental radiation biology relating to the MRT response, a potential new therapy for cancer patients.

  10. PREFACE: European Microbeam Analysis Society's 14th European Workshop on Modern Developments and Applications in Microbeam Analysis (EMAS 2015), Portorož, Slovenia, 3-7 May 2015

    Science.gov (United States)

    Llovet, Xavier; Matthews, Michael B.; Čeh, Miran; Langer, Enrico; Žagar, Kristina

    2016-02-01

    This volume of the IOP Conference Series: Materials Science and Engineering contains papers from the 14th Workshop of the European Microbeam Analysis Society (EMAS) on Modern Developments and Applications in Microbeam Analysis which took place from the 3rd to the 7th of May 2015 in the Grand Hotel Bernardin, Portorož, Slovenia. The primary aim of this series of workshops is to assess the state-of-the-art and reliability of microbeam analysis techniques. The workshops also provide a forum where students and young scientists starting out on a career in microbeam analysis can meet and discuss with the established experts. The workshops have a unique format comprising invited plenary lectures by internationally recognized experts, poster presentations by the participants and round table discussions on the key topics led by specialists in the field.This workshop was organized in collaboration with the Jožef Stefan Institute and SDM - Slovene Society for Microscopy. The technical programme included the following topics: electron probe microanalysis, STEM and EELS, materials applications, cathodoluminescence and electron backscatter diffraction (EBSD), and their applications. As at previous workshops there was also a special oral session for young scientists. The best presentation by a young scientist was awarded with an invitation to attend the 2016 Microscopy and Microanalysis meeting at Columbus, Ohio. The prize went to Shirin Kaboli, of the Department of Metals and Materials Engineering of McGill University (Montréal, Canada), for her talk entitled "Electron channelling contrast reconstruction with electron backscattered diffraction". The continuing relevance of the EMAS workshops and the high regard in which they are held internationally can be seen from the fact that 71 posters from 16 countries were on display at the meeting and that the participants came from as far away as Japan, Canada, USA, and Australia. A selection of participants with posters was invited

  11. A Galerkin-Parameterization Method for the Optimal Control of Smart Microbeams

    Directory of Open Access Journals (Sweden)

    Marwan Abukhaled

    2009-01-01

    Full Text Available A proposed computational method is applied to damp out the excess vibrations in smart microbeams, where the control action is implemented using piezoceramic actuators. From a mathematical point of view, we wish to determine the optimal boundary actuators that minimize a given energy-based performance measure. The minimization of the performance measure over the actuators is subjected to the full motion of the structural vibrations of the micro-beams. A direct state-control parametrization approach is proposed where the shifted Legendre polynomials are employed to solve the optimization problem. Legendre operational matrix and the properties of Kronecker product are utilized to find the approximated optimal trajectory and optimal control law of the lumped parameter systems with respect to the quadratic cost function by solving linear algebraic equations. Numerical examples are provided to demonstrate the applicability and efficiency of the proposed approach.

  12. The mechanics of anaphase B in a basidiomycete as revealed by laser microbeam microsurgery

    International Nuclear Information System (INIS)

    Bayles, C.J.; Aist, J.R.; Berns, M.W.

    1993-01-01

    Bayles, C. J., Aist, J. R., and Berns, M. W. 1993. The mechanics of anaphase B in a basidiomycete as revealed by laser microbeam microsurgery. Experimental Mycology 17, 191-199. Cytoplasmic forces were found to be actively pulling on the spindle pole bodies during anaphase B in the dikaryotic, basidiomycete fungus, Helicobasidium mompa. When the spindle of one nucleus was severed with a laser microbeam at mid anaphase B, its two spindle pole bodies separated at a much faster rate than did those of the intact spindle in the other nucleus of the same cell. Since astral microtubule populations apparently reach their maximum during anaphase B in this fungus, we suggest that these microtubules may be involved in the cytoplasmic pulling forces. The spindle appears to act primarily as a governor, regulating the rate at which the spindle pole bodies are separated

  13. Correlated microradiography, X-ray microbeam diffraction and electron probe microanalysis of calcifications in an odontoma

    International Nuclear Information System (INIS)

    Aoba, T.; Yoshioka, C.; Yagi, T.

    1980-01-01

    Using microradiography, X-ray microbeam diffraction and electron probe microanalysis, a correlated morphologic and crystallographic study was performed on dysplastic enamel in a compound odontoma. The tumor was found in the lateral incisor-canine region of the left mandible of a 36-year-old woman. A conspicuous feature was the presence of hypomineralized areas, which were situated in the proximity of enamel surface and distinctly demarcated from the adjacent enamel. X-ray microbeam diffraction and electron microanalysis showed that these lesions have a lower crystallinity and a higher concentration of magnesium as compared with the adjacent enamel. In addition, the present study revealed the presence of two other types of calcifications: 1) calcified structures within the fissure or on the enamel surface, which include lacunae of varying size and which resemble a form of coronal cementum, and 2) spherical calcifications which may be an epithelial product. (author)

  14. In-air ion beam analysis with high spatial resolution proton microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Jakšić, M.; Chokheli, D.; Fazinić, S.; Grilj, V.; Skukan, N.; Sudić, I.; Tadić, T.; Antičić, T.

    2016-03-15

    One of the possible ways to maintain the micrometre spatial resolution while performing ion beam analysis in the air is to increase the energy of ions. In order to explore capabilities and limitations of this approach, we have tested a range of proton beam energies (2–6 MeV) using in-air STIM (Scanning Ion Transmission Microscopy) setup. Measurements of the spatial resolution dependence on proton energy have been compared with SRIM simulation and modelling of proton multiple scattering by different approaches. Results were used to select experimental conditions in which 1 micrometre spatial resolution could be obtained. High resolution in-air microbeam could be applied for IBIC (Ion Beam Induced Charge) tests of large detectors used in nuclear and high energy physics that otherwise cannot be tested in relatively small microbeam vacuum chambers.

  15. Simultaneous ion luminescence imaging and spectroscopy of individual aerosol particles with external proton or helium microbeams

    Energy Technology Data Exchange (ETDEWEB)

    Kada, Wataru, E-mail: kada.wataru@gunma-u.ac.jp [Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Satoh, Takahiro; Yokoyama, Akihito; Koka, Masashi; Kamiya, Tomihiro [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan)

    2014-08-01

    Simultaneous microscopic imaging and spectroscopy of individual aerosol particles were performed with an external microbeam. Visible luminescence induced by the external microbeam was successfully used as a probe to detect organic contaminants in the targets. Combined ion luminescence (IL)/particle-induced X-ray emission (PIXE) analysis of the aerosol targets revealed microscopic chemical and elemental composition distributions under ambient atmospheric conditions. The simple confocal micro-optics for the IL spectroscopy and microscopic imaging were sufficiently sensitive for detecting these molecules at sub-parts per million concentrations and at a wavelength resolution of less than 5 nm. The IL spectra were monitored to prevent severe damage to the samples. Furthermore, our IL system has the advantage that it is simple to add to a conventional micro-PIXE system.

  16. PIXE/PIGE characterisation of emeralds using an external micro-beam

    International Nuclear Information System (INIS)

    Calligaro, T.; Dran, J.-C.; Poirot, J.-P.; Querre, G.; Salomon, J.; Zwaan, J.C.

    2000-01-01

    A large collection of emeralds of various occurrences has been analysed by PIXE/PIGE in view to establish a compositional database. Major elements (Be, Si, Al) and trace elements (Li, F, Na, Mg, Ca, Rb, Cs and transition metals) are determined using an external 3 MeV proton micro-beam. Elemental micro-mapping permits to select the useful provenance tracers. This database was applied to infer the origin of several ancient emeralds set on historical jewels

  17. X-ray microbeams based on Kumakhov polycapillary optics and its ...

    Indian Academy of Sciences (India)

    In [6,7] at the output of a system of microfocus X-ray generator/cylindrical polycapil- lary system (figure 1), the authors received intense quasi-parallel X-ray microbeams with the density of .... [1] M A Kumakhov and F F Komarov, Phys. Rep. 191, 290 (1990). [2] X-ray and neutron capillary optics II. Proc. SPIE 5943, 336 (2005).

  18. Ultra-high resolution optical CT dosimetry for the visualisation of synchrotron microbeam therapy doses

    OpenAIRE

    Doran, S. J.; Rahman, A. T. Abdul; Braeuer-Krisch, E.; Brochard, T.; Adamovics, J.

    2012-01-01

    International audience; Optical CT is a method that can potentially provide both accurate dosimetry at high spatial resolution and 3-D visualisation over a large field-of-view in a single dataset. The major factors limiting spatial resolution in previous studies are analysed here and it is shown that improvements in equipment specification can overcome many of these. The need for ultra-high spatial resolution in the verification of microbeam radiation therapy verification is demonstrated and ...

  19. High resolution 3D dosimetry for microbeam radiation therapy using optical CT

    OpenAIRE

    McErlean, C.; Braeuer-Krisch, E.; Adamovics, J.; Leach, M. O.; Doran, S. J.

    2014-01-01

    International audience; Optical Computed Tomography (CT) is a promising technique for dosimetry of Microbeam Radiation Therapy (MRT), providing high resolution 3D dose maps. Here different MRT irradiation geometries are visualised showing the potential of Optical CT as a tool for future MRT trials. The Peak-to-Valley dose ratio (PVDR) is calculated to be 7 at a depth of 3mm in the radiochromic dosimeter PRESAGE (R). This is significantly lower than predicted values and possible reasons for th...

  20. Microbeam dynamic shaping by closed-loop electrostatic actuation using modal control

    OpenAIRE

    Kharrat, Chady; Colinet, Eric; Voda, Alina

    2007-01-01

    International audience; A closed-loop control approach for the dynamic shaping of a microbeam by electrostatic actuation is described. Starting from a desired displacements reference vector of N small segments of the beam (representing the approximation of the continuous case), n controllers (n is the number of considered modes) output the stresses that must be distributed throughout the beam, on the N actuators. Because this reference may vary with time, the controllers are designed so that ...

  1. Interface or Interlace?

    DEFF Research Database (Denmark)

    Hansen, Lone Koefoed; Wamberg, Jacob

    2005-01-01

    Departing from an analysis of the computer's indeterminate location between medium and machine, this paper problematises the idea of a clear-cut interface in complex computing, especially Augmented Reality. The idea and pratice of the interface is derived from the medium as a representational...

  2. On the Nonlinear Dynamics of a Doubly Clamped Microbeam near Primary Resonance

    KAUST Repository

    Jaber, Nizar

    2017-04-07

    This work aims to investigate theoretically and experimentally various nonlinear dynamic behaviors of a doubly clamped microbeam near its primary resonance. Mainly, we investigate the transition behavior from hardening, mixed, and then softening behavior. We show in a single frequency-response curve, under a constant voltage load, the transition from hardening to softening behavior demonstrating the dominance of the quadratic electrostatic nonlinearity over the cubic geometric nonlinearity of the beam as the motion amplitudes becomes large, which may lead eventually to dynamic pull-in. The microbeam is fabricated using polyimide as a structural layer coated with nickel from top and chromium and gold layers from the bottom. Frequency sweep tests are conducted for different values of DC bias revealing hardening, mixed, and softening behavior of the microbeam. A multi-mode Galerkin model combined with a shooting technique are implemented to generate the frequency response curves and to analyze the stability of the periodic motions using the Floquet theory. The simulated curves show good agreement with the experimental data.

  3. Dynamics of a clamped–clamped microbeam resonator considering fabrication imperfections

    KAUST Repository

    Bataineh, Ahmad M.

    2014-10-18

    We present an investigation into the static and dynamic behavior of an electrostatically actuated clamped–clamped polysilicon microbeam resonator accounting for its fabrication imperfections, which are commonly encountered in similar microstructures. These are mainly because of the initial deformation of the beam due to stress gradient and its flexible anchors. First, we show experimental data of the microbeam when driven electrically by varying the amplitude and frequency of the voltage loads. The results reveal several interesting nonlinear phenomena of jumps, hysteresis, and softening behaviors. Theoretical investigation is then conducted to model the microbeam, and hence, interpret the experimental data. We solve the Eigen value problem governing the natural frequencies analytically. We then utilize a Galerkin-based procedure to derive a reduced order model, which is then used to simulate both the static and dynamic responses. To achieve good matching between theory and experiment, we show that the exact profile of the deformed beam needs to be utilized in the reduced order model, as measured from the optical profiler, combined with a shooting technique simulation, which is capable of tracing the resonant frequency branches under very-low damping conditions.

  4. Development of economic MeV-ion microbeam technology at Chiang Mai University

    Science.gov (United States)

    Singkarat, S.; Puttaraksa, N.; Unai, S.; Yu, L. D.; Singkarat, K.; Pussadee, N.; Whitlow, H. J.; Natyanum, S.; Tippawan, U.

    2017-08-01

    Developing high technologies but in economic manners is necessary and also feasible for developing countries. At Chiang Mai University, Thailand, we have developed MeV-ion microbeam technology based on a 1.7-MV Tandetron tandem accelerator with our limited resources in a cost-effective manner. Instead of using expensive and technically complex electrostatic or magnetic quadrupole focusing lens systems, we have developed cheap MeV-ion microbeams using programmed L-shaped blade aperture and capillary techniques for MeV ion beam lithography or writing and mapping. The programmed L-shaped blade micro-aperture system consists of a pair of L-shaped movable aperture pieces which are controlled by computer to cut off the ion beam for controlling the beam size down to the micrometer order. The capillary technique utilizes our home-fabricated tapered glass capillaries to realize microbeams. Either system can be installed inside the endstation of the MeV ion beam line of the accelerator. Both systems have been applied to MeV-ion beam lithography or writing of micro-patterns for microfluidics applications to fabricate lab-on-chip devices. The capillary technique is being developed for MeV-ion beam mapping of biological samples. The paper reports details of the techniques and introduces some applications.

  5. Nonlinear behavior of capacitive micro-beams based on strain gradient theory

    International Nuclear Information System (INIS)

    Fathalilou, Mohammad; Sadeghi, Morteza; Rezazadeh, Ghader

    2014-01-01

    This paper studies the size dependent behavior of materials in MEMS structures. This behavior becomes noticeable for a structure when the characteristic size such as thickness or diameter is close to its internal length-scale parameter and is insignificant for the high ratio of the characteristic size to the length-scale parameter, which is the case of the silicon base micro-beams. However, in some types of micro-beams like gold or nickel bases, the size dependent effect cannot be overlooked. In such cases, ignoring this behavior in modeling will lead to incorrect results. Some previous researchers have applied classic beam theory on their models and imposed a considerable hypothetical value of residual stress to match their theoretical results with the experimental ones. The equilibrium positions or fixed points of the gold and nickel micro-beams are obtained and shown that for a given DC voltage, there is a considerable difference between the obtained fixed points using classic beam theory, modified couple stress theory, and modified strain gradient theory. In addition, it is shown that the calculated static and dynamic pull-in voltages using higher order theories are much closer to the experimental results and are higher several times than those obtained by classic beam theory.

  6. Magnetic arrays

    Science.gov (United States)

    Trumper, D.L.; Kim, W.; Williams, M.E.

    1997-05-20

    Electromagnet arrays are disclosed which can provide selected field patterns in either two or three dimensions, and in particular, which can provide single-sided field patterns in two or three dimensions. These features are achieved by providing arrays which have current densities that vary in the windings both parallel to the array and in the direction of array thickness. 12 figs.

  7. Magnetic arrays

    Energy Technology Data Exchange (ETDEWEB)

    Trumper, David L. (Plaistow, NH); Kim, Won-jong (Cambridge, MA); Williams, Mark E. (Pelham, NH)

    1997-05-20

    Electromagnet arrays which can provide selected field patterns in either two or three dimensions, and in particular, which can provide single-sided field patterns in two or three dimensions. These features are achieved by providing arrays which have current densities that vary in the windings both parallel to the array and in the direction of array thickness.

  8. Synchrotron high angular resolution microdiffraction analysis of selective area grown optoelectronic waveguide arrays

    International Nuclear Information System (INIS)

    Kazimirov, A; Sirenko, A A; Bilderback, D H; Cai, Z-H; Lai, B; Huang, R; Ougazzaden, A

    2006-01-01

    A synchrotron microbeam high-angular resolution diffraction setup based on a phase zone plate and a perfect Si(004) analyzer crystal was introduced to generate an x-ray microbeam with a lateral size of 0.24 μm and an angular resolution of 2 arcsec. The microbeam high angular resolution x-ray diffraction was applied to study InGaAlAs-based multiple quantum well (MQW) ridge-waveguide arrays produced by metal-organic vapour-phase epitaxy in a selective area growth regime with a central waveguide width varying from 1.6 to 60 μm. The analysis of the period T and the strain S in MQW ridge structures determined from the high-resolution diffraction data is presented. It was found that the MQW period is uniform across the ridge within the error bar of ΔT = ± 0.25 nm. Within the waveguide array, the MQW period and strain can be adequately described by a gas-phase diffusion model

  9. Measurement of minute local strain in semiconductor materials and electronic devices by using a highly parallel X-ray microbeam

    CERN Document Server

    Matsui, J; Yokoyama, K; Takeda, S; Katou, M; Kurihara, H; Watanabe, K; Kagoshima, Y; Kimura, S

    2003-01-01

    We have developed an X-ray microbeam with a small angular divergence by adopting X-ray optics with successive use of asymmetric Bragg reflection from silicon crystals for the both polarizations of the synchrotron X-rays. The microbeam actually obtained is several microns in size and possesses an angular divergence of less than 2 arcsec which enables us to measure the strain of 10 sup - sup 5 -10 sup - sup 6. By scanning the sample against the microbeam, distribution of the minute local strain in various regions of semiconductor crystals for electronic devices, e.g., the strain around the SiO sub 2 /Si film edge in silicon devices, the strain in an InGaAsP/InP stripe laser were measured.

  10. Investigation of chemical vapour deposition diamond detectors by X- ray micro-beam induced current and X-ray micro-beam induced luminescence techniques

    CERN Document Server

    Olivero, P; Vittone, E; Fizzotti, F; Paolini, C; Lo Giudice, A; Barrett, R; Tucoulou, R

    2004-01-01

    Tracking detectors have become an important ingredient in high-energy physics experiments. In order to survive the harsh detection environment of the Large Hadron Collider (LHC), trackers need to have special properties. They must be radiation hard, provide fast collection of charge, be as thin as possible and remove heat from readout electronics. The unique properties of diamond allow it to fulfill these requirements. In this work we present an investigation of the charge transport and luminescence properties of "detector grade" artificial chemical vapour deposition (CVD) diamond devices developed within the CERN RD42 collaboration, performed by means of X-ray micro-beam induced current collection (XBICC) and X-ray micro- beam induced luminescence (XBIL) techniques. XBICC technique allows quantitative estimates of the transport parameters of the material to be evaluated and mapped with micrometric spatial resolution. In particular, the high resolution and sensitivity of the technique has allowed a quantitati...

  11. Effects of high-dose microbeam irradiation on tumor microvascular function and angiogenesis.

    Science.gov (United States)

    Fontanella, Andrew N; Boss, Mary-Keara; Hadsell, Michael; Zhang, Jian; Schroeder, Thies; Berman, Katherine G; Dewhirst, Mark W; Chang, Sha; Palmer, Gregory M

    2015-02-01

    Microbeam radiation therapy (MRT) is a form of cancer treatment in which a single large dose of radiation is spatially fractionated in-line or grid-like patterns. Preclinical studies have demonstrated that MRT is capable of eliciting high levels of tumor response while sparing normal tissue that is exposed to the same radiation field. Since a large fraction of the MRT-treated tumor is in the dose valley region that is not directly irradiated, tumor response may be driven by radiation bystander effects, which in turn elicit a microvascular response. Differential alterations in hemodynamics between the tumor and normal tissue may explain the therapeutic advantages of MRT. Direct observation of these dynamic responses presents a challenge for conventional ex vivo analysis. Furthermore, knowledge gleaned from in vitro studies of radiation bystander response has not been widely incorporated into in vivo models of tumor radiotherapy, and the biological contribution of the bystander effect within the tumor microenvironment is unknown. In this study, we employed noninvasive, serial observations of the tumor microenvironment to address the question of how tumor vasculature and HIF-1 expression are affected by microbeam radiotherapy. Tumors (approximately 4 mm in diameter) grown in a dorsal window chamber were irradiated in a single fraction using either a single, microplanar beam (300 micron wide swath) or a wide-field setup (whole-window chamber) to a total dose of 50 Gy. The tumors were optically observed daily for seven days postirradiation. Microvascular changes in the tumor and surrounding normal tissue differed greatly between the wide-field and microbeam treatments. We present evidence that these changes may be due to dissimilar spatial and temporal patterns of HIF-1 expression induced through radiation bystander effects.

  12. Laser microbeam abalation of GFP-labeled nuclear organelles in a living cell.

    Science.gov (United States)

    LaMorte, Vickie J.; Krasieva, Tatiana B.; Evans, Ronald M.; Berns, Michael W.; Tromberg, Bruce J.

    1997-05-01

    Cancer, development, cellular growth and differentiation are governed by gene expression. Recent molecular and cellular advances to visualize and perturb the pathways of transcriptional regulation, nascent RNA processing, and protein trafficking at the single cell level have been developed. More recently, applications utilizing the green fluorescent marker (GFP) from Aequorea victoria have facilitated visualization of these molecular events in a living cell. Specifically, we will describe a novel approach to perturb cellular processes by labeling discrete cellular components of interest with GFP and subsequently altering/ablating them with a laser microbeam.

  13. Scanning ion micro-beam techniques for measuring diffusion in heterogeneous materials

    International Nuclear Information System (INIS)

    Jenneson, P.M.; Clough, A.S.

    1998-01-01

    A raster scanning MeV micro-beam of 1 H + or 3 He + ions was used to study the diffusion of small molecules in heterogeneous materials. The location of elemental contaminants (heavier than Lithium) in polymer insulated cables was studied with 1 H micro-Particle Induced X-ray Emission (μPIXE). Concentration profiles of a deuterated molecule in a hair fibre were determined with 3 He micro-Nuclear Reaction Analysis (μNRA). Chlorine and heavy water (D 2 0) diffusion into cement pastes were profiled using a combination of 3 He μPIXE and μNRA. (authors)

  14. MeV He microbeam analysis of a semiconductor integrated circuit

    International Nuclear Information System (INIS)

    Zhu Peiran; Liu Jiarui; Zhang Jinping; Yin Shiduan

    1989-01-01

    An MeV He + microbeam has been used to analyse a microscale semiconductor structure. The 2 MeV He + ion beam is limited to 25 μm diameter by a set of diaphragms and is further focused by a quadrupole quadruplet to 3μm diameter. The incident beam current on the sample is about 0.3 nA. The Rutherford backscattering (RBS) technique is applied to the measurement of the composition and depth profile in the near-surface region of a semiconductor integrated circuit. (author)

  15. Scanning RBS-PIXE study of ancient artifacts from South America using a microbeam

    Science.gov (United States)

    Ruvalcaba-Sil, J. L.; Demortier, G.

    1997-07-01

    Pre-Hispanic goldsmiths developed original techniques to manufacture and to gild ornaments and artifacts. Gold metallurgy in ancient America was mainly a surface technology. Surface studies of artifacts from various regions of pre-Hispanic South America were carried out using a 2 MeV proton microbeam (10 μm diameter). Several regions of the artifacts were scanned: RBS and PIXE were used simultaneously to determine the elemental composition and to characterize the homogeneity in depth and at the surface. Complementary information is provided from previous analyses using a macrobeam. Outstanding aspects about the metallurgical processes involved in the gilding of the artifacts have been established.

  16. Microbeam line of MeV heavy ions for materials modification and in-situ analysis

    International Nuclear Information System (INIS)

    Horino, Yuji; Chayahara, Akiyoshi; Kiuchi, Masato; Fujii, Kanenaga; Satoh, Mamoru; Takai, Mikio.

    1990-01-01

    A microbeam line for MeV heavy ions of almost any element has been developed for microion-beam processing such as maskless MeV ion implantation and its in-situ analysis. Beam spot sizes of 4.0 μm x 4.0 μm for 3 MeV C 2+ and 9.6 μm x 4.8 μm for 1.8 MeV Au 2+ beams were obtained. Maskless MeV gold ion implantation to a silicon substrate and in-situ microanalysis before and after ion implantation were demonstrated. (author)

  17. Scanning three-dimensional x-ray diffraction microscopy using a high-energy microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Y., E-mail: y-hayashi@mosk.tytlabs.co.jp; Hirose, Y.; Seno, Y. [Toyota Central R& D Toyota Central R& D Labs., Inc., 41-1 Nagakute Aichi 480-1192 Japan (Japan)

    2016-07-27

    A scanning three-dimensional X-ray diffraction (3DXRD) microscope apparatus with a high-energy microbeam was installed at the BL33XU Toyota beamline at SPring-8. The size of the 50 keV beam focused using Kirkpatrick-Baez mirrors was 1.3 μm wide and 1.6 μm high in full width at half maximum. The scanning 3DXRD method was tested for a cold-rolled carbon steel sheet sample. A three-dimensional orientation map with 37 {sup 3} voxels was obtained.

  18. Interaction of proton microbeam with the inner surface of a polytetrafluoroethylene macrocapillary

    Energy Technology Data Exchange (ETDEWEB)

    Rajta, I.; Nagy, G.U.L.; Bereczky, R.J.; Tőkési, K.

    2015-07-01

    The transmission of 1 MeV proton microbeam through a single, cylindrically shaped, micrometre-sized polytetrafluoroethylene capillary was studied. The capillary axis was tilted with respect to the axis of the incident ion beam. The tilting, the aspect ratio of the capillary and the small beam divergence disabled the geometrical transmission of the beam through the target. The time dependence of the intensity, the charge-state and the deflection of the transmitted beam were investigated. We found that pure guided transmission of a MeV/amu energy ion beam is possible through an insulator capillary.

  19. Free vibration analysis of magneto-electro-elastic microbeams subjected to magneto-electric loads

    Science.gov (United States)

    Vaezi, Mohamad; Shirbani, Meisam Moory; Hajnayeb, Ali

    2016-01-01

    Different types of actuating and sensing mechanisms are used in new micro and nanoscale devices. Therefore, a new challenge is modeling electromechanical systems that use these mechanisms. In this paper, free vibration of a magnetoelectroelastic (MEE) microbeam is investigated in order to obtain its natural frequencies and buckling loads. The beam is simply supported at both ends. External electric and magnetic potentials are applied to the beam. By using the Hamilton's principle, the governing equations and boundary conditions are derived based on the Euler-Bernoulli beam theory. The equations are solved, analytically to obtain the natural frequencies of the MEE microbeam. Furthermore, the effects of external electric and magnetic potentials on the buckling of the beam are analyzed and the critical values of the potentials are obtained. Finally, a numerical study is conducted. It is found that the natural frequency can be tuned directly by changing the magnetic and electric potentials. Additionally, a closed form solution for the normalized natural frequency is derived, and buckling loads are calculated in a numerical example.

  20. Study of Thermoelastic Damping in Capacitive Micro-beam Resonators Using Hyperbolic Heat Conduction Model

    Directory of Open Access Journals (Sweden)

    Ghader Rezazadeh

    2009-09-01

    Full Text Available In the present study, equations of coupled thermoelastic case have been derived using non-Fourier thermal conduction model for a capacitive micro-beam resonator. The Heat conduction is considered to exist in both longitudinal and cross sectional directions. The Quality factor of TED (QTED for two different cases, including two dimensional parabolic (TDP, and one dimensional hyperbolic (ODH heat conduction models have been studied. The results are compared to those of applying one dimensional parabolic (ODP heat conduction model. As the results illustrate QTED of TDP and ODH models are strongly in agreement with those of ODP model. Size-dependency of QTED has been investigated using two dimensional hyperbolic heat conduction model (TDH. According to the results, the values of critical thicknesses achieved of our calculations have a good agreement with the analytical values. By applying TDH model, the effect DC voltage on QTED for an electrostatically deflected micro-beam has been investigated. The results show that the bias DC voltage decreases the QTED, and its influence is more considerable in the vicinity of pull-in position. Air damping (AD and TED has been compared together for various dimensions. The results present that the comparison of quality factor related to AD (QAD and QTED is completely size-dependent.

  1. Effects of locally targeted heavy-ion and laser microbeam on root hydrotropism in Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Miyazawa, Yutaka; Sakashita, Tetsuya; Funayama, Tomoo

    2008-01-01

    Classical studies on root hydrotropism have hypothesized the importance of columella cells as well as the de novo gene expression, such as auxin-inducible gene, at the elongation zone in hydrotropism; however, there has been no confirmation that columella cells or auxin-mediated signaling in the elongation zone are necessary for hydrotropism. We examined the role of root cap and elongation zone cells in root hydrotropism using heavy-ion and laser microbeam. Heavy-ion microbeam irradiation of the elongation zone, but not that of the columella cells, significantly and temporarily suppressed the development of hydrotropic curvature. However, laser ablation confirmed that columella cells are indispensable for hydrotropism. Systemic heavy-ion broad-beam irradiation suppressed de novo expression of INDOLE ACETIC ACID 5 gene, but not MIZU-KUSSEI1 gene. Our results indicate that both the root cap and elongation zone have indispensable and functionally distinct roles in root hydrotropism, and that de novo gene expression might be required for hydrotropism in the elongation zone, but not in columella cells. (author)

  2. An Electrically Actuated Microbeam-Based MEMS Device: Experimental and Theoretical Investigation

    KAUST Repository

    Ruzziconi, Laura

    2017-11-03

    The present paper deals with the dynamic behavior of a microelectromechanical systems (MEMS). The device consists of a clamped-clamped microbeam electrostatically and electrodynamically actuated. Our objective is to develop a theoretical analysis, which is able to describe and predict all the main relevant aspects of the experimental response. In the first part of the paper an extensive experimental investigation is conducted. The microbeam is perfectly straight. The first three experimental natural frequencies are identified and the nonlinear dynamics are explored at increasing values of electrodynamic excitation. Several backward and forward frequency sweeps are acquired. The nonlinear behavior is highlighted. The experimental data show the coexistence of the nonresonant and the resonant branch, which perform a bending toward higher frequencies values before undergoing jump or pull-in dynamics. This kind of bending is not particularly common in MEMS. In the second part of the paper, a theoretical single degree-of-freedom model is derived. The unknown parameters are extracted and settled via parametric identification. A single mode reduced-order model is considered, which is obtained via the Galerkin technique. To enhance the computational efficiency, the contribution of the electric force term is computed in advance and stored in a table. Extensive numerical simulations are performed at increasing values of electrodynamic excitation. They are observed to properly predict all the main nonlinear features arising in the device response. This occurs not only at low values of electrodynamic excitation, but also at higher ones

  3. On using the dynamic snap-through motion of MEMS initially curved microbeams for filtering applications

    KAUST Repository

    Ouakad, Hassen M.

    2014-01-01

    Numerical and experimental investigations of the dynamics of micromachined shallow arches (initially curved microbeams) and the possibility of using their dynamic snap-through motion for filtering purposes are presented. The considered MEMS arches are actuated by a DC electrostatic load along with an AC harmonic load. Their dynamics is examined numerically using a Galerkin-based reduced-order model when excited near both their first and third natural frequencies. Several simulation results are presented demonstrating interesting jumps and dynamic snap-through behavior of the MEMS arches and their attractive features for uses as band-pass filters, such as their sharp roll-off from pass-bands to stop-bands and their flat response. Experimental work is conducted to test arches realized of curved polysilicon microbeams when excited by DC and AC loads. Experimental data of the micromachined curved beams are shown for the softening and hardening behavior near the first and third natural frequencies, respectively, as well as dynamic snap-through motion. © 2013 Elsevier Ltd.

  4. The Columbia University proton-induced soft x-ray microbeam.

    Science.gov (United States)

    Harken, Andrew D; Randers-Pehrson, Gerhard; Johnson, Gary W; Brenner, David J

    2011-09-15

    A soft x-ray microbeam using proton-induced x-ray emission (PIXE) of characteristic titanium (K(α) 4.5 keV) as the x-ray source has been developed at the Radiological Research Accelerator Facility (RARAF) at Columbia University. The proton beam is focused to a 120 μm × 50 μm spot on the titanium target using an electrostatic quadrupole quadruplet previously used for the charged particle microbeam studies at RARAF. The proton induced x-rays from this spot project a 50 μm round x-ray generation spot into the vertical direction. The x-rays are focused to a spot size of 5 μm in diameter using a Fresnel zone plate. The x-rays have an attenuation length of (1/e length of ~145 μm) allowing more consistent dose delivery across the depth of a single cell layer and penetration into tissue samples than previous ultra soft x-ray systems. The irradiation end station is based on our previous design to allow quick comparison to charged particle experiments and for mixed irradiation experiments.

  5. A Microbeam Small-Angle X-ray Scattering Study on Enamel Crystallites in Subsurface Lesion

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, N; Ohta, N; Matsuo, T [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Tanaka, T; Terada, Y; Kamasaka, H; Kometani, T, E-mail: yagi@spring8.or.j [Ezaki Glico Co. Ltd., 4-6-5 Utajima, Nishiyodogawa-ku, Osaka 555-8502 (Japan)

    2010-10-01

    The early caries lesion in bovine tooth enamel was studied by two different X-ray diffraction systems at the SPring-8 third generation synchrotron radiation facility. Both allowed us simultaneous measurement of the small and large angle regions. The beam size was 6{mu}m at BL40XU and 50{mu}m at BL45XU. The small-angle scattering from voids in the hydroxyapatite crystallites and the wide-angle diffraction from the hydroxyapatite crystals were observed simultaneously. At BL40XU an X-ray image intensifier was used for the small-angle and a CMOS flatpanel detector for the large-angle region. At BL45XU, a large-area CCD detector was used to cover both regions. A linear microbeam scan at BL40XU showed a detailed distribution of voids and crystals and made it possible to examine the structural details in the lesion. The two-dimensional scan at BL45XU showed distribution of voids and crystals in a wider region in the enamel. The simultaneous small- and wide-angle measurement with a microbeam is a powerful tool to elucidate the mechanisms of demineralization and remineralization in the early caries lesion.

  6. Paintings on copper by the Flemish artist Frans Francken II: PIXE characterization by external microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Corregidor, V., E-mail: vicky.corregidor@ctn.ist.utl.pt [IPFN, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Universidade de Lisboa, E.N. 10, 2695-066 Sacavém (Portugal); Oliveira, A.R. [CCR-Centro de Conservação e Restauro, R. do Ginjal, 11, 2950-685 Palmela (Portugal); Rodrigues, P.A. [LATR, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Universidade de Lisboa, E.N. 10, 2695-066 Sacavém (Portugal); Alves, L.C. [C2TN, Instituto Superior Técnico, Campus Tecnológico e Nuclear, Universidade de Lisboa, E.N. 10, 2695-066 Sacavém (Portugal)

    2015-04-01

    Resorting to an external proton microbeam, PIXE analyses of three oil paintings on copper support dated from the XVII century and attributed to the Flemish artist Frans Francken II, were undertaken. The present work aims to contribute to the compositional study of the painting materials employed by XVII century artists that exploited copper as a support for oil painting, and specifically the materials used by Francken’s workshop, particularly copper plates. Because of the low thickness of the pictorial layers of this type of paintings and its non-destructive character, PIXE is the ideal technique to study the elemental composition of the paintings. Several spots in each painting were chosen for analysis in order to cover almost all the pigments used in the colour palette. Lead and calcium were detected in practically every analysed regions, probably related to the presence of lead white and chalk, usually used as ground layer on copper paintings. Small quantities of gold were also detected, which is present in many of this artist’s works to embellish some details of the representations. Also this work reports the first application of the external proton microbeam set-up available at CTN/IST in Portugal for the characterization of oil paintings.

  7. PREFACE: Proceedings of the 11th European Workshop of the European Microbeam Analysis Society (EMAS) on Modern Developments and Applications in Microbeam Analysis

    Science.gov (United States)

    2010-07-01

    This volume of IOP Conference Series: Materials Science and Engineering contains papers from the 11th Workshop of the European Microbeam Analysis Society (EMAS) on Modern Developments and Applications in Microbeam Analysis which took place from 10-14 May 2009 in the Hotel Faltom, Gdynia, Poland. The primary aim of this series of workshops is to assess the state-of-the-art and reliability of microbeam analysis techniques. The workshops also provide a forum where students and young scientists starting out on careers in microbeam analysis can meet and discuss with the established experts. The workshops have a very distinct format comprising invited plenary lectures by internationally recognized experts, poster presentations by the participants and round table discussions on the key topics led by specialists in the field. For this workshop EMAS invited speakers on the following topics: EPMA, EBSD, fast energy-dispersive X-ray spectroscopy, three-dimensional microanalysis, and micro-and nanoanalysis in the natural resources industry. The continuing relevance of the EMAS workshops and the high regard in which they are held internationally can be seen from the fact that 69 posters from 16 countries were on display at the meeting and that the participants came from as far away as Japan and the USA. A number of participants with posters were invited to give short oral presentations of their work in two dedicated sessions. As at previous workshops there was also a special oral session for young scientists. Small cash prizes were awarded for the three best posters and for the best oral presentation by a young scientist. The prize for the best poster went to the contribution by G Tylko, S Dubchak, Z Banach and K Turnau, entitled Monte Carlo simulation for an assessment of standard validity and quantitative X-ray microanalysis in plant. Joanna Wojewoda-Budka of the Institute of Metallurgy and Materials Science, Krakow, received the prize for the best oral presentation by a

  8. PREFACE: EMAS 2013 Workshop: 13th European Workshop on Modern Developments and Applications in Microbeam Analysis

    Science.gov (United States)

    Llovet, Xavier, Dr; Matthews, Mr Michael B.; Brisset, François, Dr; Guimarães, Fernanda, Dr; Vieira, Professor Joaquim M., Dr

    2014-03-01

    This volume of the IOP Conference Series: Materials Science and Engineering contains papers from the 13th Workshop of the European Microbeam Analysis Society (EMAS) on Modern Developments and Applications in Microbeam Analysis which took place from the 12th to the 16th of May 2013 in the Centro de Congressos do Alfândega, Porto, Portugal. The primary aim of this series of workshops is to assess the state-of-the-art and reliability of microbeam analysis techniques. The workshops also provide a forum where students and young scientists starting out on a career in microbeam analysis can meet and discuss with the established experts. The workshops have a very specific format comprising invited plenary lectures by internationally recognized experts, poster presentations by the participants and round table discussions on the key topics led by specialists in the field. This workshop was organized in collaboration with LNEG - Laboratório Nacional de Energia e Geologia and SPMICROS - Sociedade Portuguesa de Microscopia. The technical programme included the following topics: electron probe microanalysis, future technologies, electron backscatter diffraction (EBSD), particle analysis, and applications. As at previous workshops there was also a special oral session for young scientists. The best presentation by a young scientist was awarded with an invitation to attend the 2014 Microscopy and Microanalysis meeting at Hartford, Connecticut. The prize went to Shirin Kaboli, of the Department of Metals and Materials Engineering of McGill University (Montréal, Canada), for her talk entitled ''Plastic deformation studies with electron channelling contrast imaging and electron backscattered diffraction''. The continuing relevance of the EMAS workshops and the high regard in which they are held internationally can be seen from the fact that 74 posters from 21 countries were on display at the meeting and that the participants came from as far away as Japan, Canada and the USA. A

  9. PREFACE: EMAS 2011: 12th European Workshop on Modern Developments in Microbeam Analysis

    Science.gov (United States)

    Brisset, François; Dugne, Olivier; Robaut, Florence; Lábár, János L.; Walker, Clive T.

    2012-03-01

    This volume of IOP Conference Series: Materials Science and Engineering contains papers from the 12th Workshop of the European Microbeam Analysis Society (EMAS) on Modern Developments and Applications in Microbeam Analysis, which took place from the 15-19 May 2011 in the Angers Congress Centre, Angers, France. The primary aim of this series of workshops is to assess the state-of-the-art and reliability of microbeam analysis techniques. The workshops also provide a forum where students and young scientists starting out on a career in microbeam analysis can meet and discuss with the established experts. The workshops have a very specific format comprising invited plenary lectures by internationally recognized experts, poster presentations by the participants and round table discussions on the key topics led by specialists in the field. This workshop was organized in collaboration with GN-MEBA - Groupement National de Microscopie Electronique à Balayage et de microAnalysis, France. The technical programme included the following topics: the limits of EPMA, new techniques, developments and concepts in microanalysis, microanalysis in the SEM, and new and less common applications of micro- and nanoanalysis. As at previous workshops there was also a special oral session for young scientists. The best presentation by a young scientist was awarded with an invitation to attend the 2012 Microscopy and Microanalysis meeting at Phoenix, Arizona. The prize went to Pierre Burdet, of the Federal Institute of Technology of Lausanne (EPFL), for his talk entitled '3D EDS microanalysis by FIB-SEM: enhancement of elemental quantification'. The continuing relevance of the EMAS workshops and the high regard in which they are held internationally can be seen from the fact that 74 posters from 18 countries were on display at the meeting, and that the participants came from as far away as Japan, Canada and the USA. A selection of participants with posters were invited to give a short oral

  10. Size-dependent dynamic stability analysis of microbeams actuated by piezoelectric voltage based on strain gradient elasticity theory

    Energy Technology Data Exchange (ETDEWEB)

    Sahmani, Saeid; Bahrami, Mohsen [Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2015-01-15

    In the current paper, dynamic stability analysis of microbeams subjected to piezoelectric voltage is presented in which the microbeam is integrated with piezoelectric layers on the lower and upper surfaces. Both of the flutter and divergence instabilities of microbeams with clamped-clamped and clamped-free boundary conditions are predicted corresponding to various values of applied voltage. To take size effect into account, the classical Timoshenko beam theory in conjunction with strain gradient elasticity theory is utilized to develop nonclassical beam model containing three additional internal length scale parameters. By using Hamilton's principle, the higher-order governing differential equations and associated boundary conditions are derived. Afterward, generalized differential quadrature method is employed to discretize the size-dependent governing differential equations along with clamped-clamped and clamped-free end supports. The critical piezoelectric voltages corresponding to various values dimensionless length scale parameter are evaluated and compared with those predicted by the classical beam theory. It is revealed that in the case of clamped-free boundary conditions, the both of flutter and divergence instabilities occur. However, for the clamped-clamped microbeams, only divergence instability takes place.

  11. Studying nanostructure gradients in injection-molded polypropylene/montmorillonite composites by microbeam small-angle x-ray scattering

    DEFF Research Database (Denmark)

    Stribeck, Norbert; Schneider, Konrad; Zeinolebadi, Ahmad

    2014-01-01

    The core–shell structure in oriented cylindrical rods of polypropylene (PP) and nanoclay composites (NCs) from PP and montmorillonite (MMT) is studied by microbeam small-angle x-ray scattering (SAXS). The structure of neat PP is almost homogeneous across the rod showing regular semicrystalline st...

  12. Vibration analysis of a rotating functionally graded tapered microbeam based on the modified couple stress theory by DQEM

    Science.gov (United States)

    Ghadiri, Majid; Shafiei, Navvab; Alireza Mousavi, S.

    2016-09-01

    Due to having difficulty in solving governing nonlinear differential equations of a non-uniform microbeam, a few numbers of authors have studied such fields. In the present study, for the first time, the size-dependent vibration behavior of a rotating functionally graded (FG) tapered microbeam based on the modified couple stress theory is investigated using differential quadrature element method (DQEM). It is assumed that physical and mechanical properties of the FG microbeam are varying along the thickness that will be defined as a power law equation. The governing equations are determined using Hamilton's principle, and DQEM is presented to obtain the results for cantilever and propped cantilever boundary conditions. The accuracy and validity of the results are shown in several numerical examples. In order to display the influence of size on the first two natural frequencies and consequently changing of some important microbeam parameters such as material length scale, rate of cross section, angular velocity and gradient index of the FG material, several diagrams and tables are represented. The results of this article can be used in designing and optimizing elastic and rotary-type micro-electro-mechanical systems like micro-motors and micro-robots including rotating parts.

  13. Array capabilities and future arrays

    International Nuclear Information System (INIS)

    Radford, D.

    1993-01-01

    Early results from the new third-generation instruments GAMMASPHERE and EUROGAM are confirming the expectation that such arrays will have a revolutionary effect on the field of high-spin nuclear structure. When completed, GAMMASHPERE will have a resolving power am order of magnitude greater that of the best second-generation arrays. When combined with other instruments such as particle-detector arrays and fragment mass analysers, the capabilites of the arrays for the study of more exotic nuclei will be further enhanced. In order to better understand the limitations of these instruments, and to design improved future detector systems, it is important to have some intelligible and reliable calculation for the relative resolving power of different instrument designs. The derivation of such a figure of merit will be briefly presented, and the relative sensitivities of arrays currently proposed or under construction presented. The design of TRIGAM, a new third-generation array proposed for Chalk River, will also be discussed. It is instructive to consider how far arrays of Compton-suppressed Ge detectors could be taken. For example, it will be shown that an idealised open-quote perfectclose quotes third-generation array of 1000 detectors has a sensitivity an order of magnitude higher again than that of GAMMASPHERE. Less conventional options for new arrays will also be explored

  14. Development of Laser Plasma X-ray Microbeam Irradiation System and Radiation Biological Application

    Science.gov (United States)

    Sato, Katsutoshi; Nishikino, Masaharu; Numasaki, Hodaka; Kawachi, Tetsuya; Teshima, Teruki; Nishimura, Hiroaki

    Laser plasma x-ray source has the features such as ultra short pulse, high brilliance, monochromaticity, and focusing ability. These features are excellent compared with conventional x-ray source. In order to apply the laser plasma x-ray source to the biomedical study and to more closely research the radiobilogical responce of the cancer cell such as radiation induced bystander effect, we have developed x-ray microbeam system using laser plasma x-ray source. The absorbed dose of laser plasma x-ray was estimated with Gafchromic EBT film and DNA double strand breaks on the cells were detected by immunofluorescence staining. When the cells were irradiated with laser plasma x-ray, the circular regions existing γ-H2AX positive cells were clearly identified. The usefulness of the laser plasma x-ray on the radiobiological study was proved in this research.

  15. Microbeam AMS measurements of PGE and Au trace and osmium isotopic ratios

    International Nuclear Information System (INIS)

    Sie, S.H.; Sims, D.A.; Suter, G.F.

    2001-01-01

    The microbeam Accelerator Mass Spectrometry (AMS) system, AUSTRALIS (AMS for Ultra Sensitive TRAce eLement and Isotopic Studies) at CSIRO Heavy Ion Analytical Facility (HIAF) has been used to measure trace levels of precious metals, the platinum group elements (PGE) and Au, from an assortment of geological and meteoritic samples with spatial resolution of 30 micrometres. For Au, detection sensitivity as low as sub parts per billion has been obtained, which will be of great benefit in studies of ore deposit mineralogy and mineral processing. We have also demonstrated the facility for osmium isotope measurements in meteorite samples, opening up the possibility of widespread use of the Re-Os system in exploration programs

  16. Modification of Teflon surface by proton microbeam and nitrogen ion beam

    Science.gov (United States)

    Kitamura (Ogawa), Akane; Satoh, Takahiro; Koka, Masashi; Kamiya, Tomihiro; Kobayashi, Tomohiro

    2013-11-01

    Teflon surfaces were modified using a combination of 3 MeV proton microbeam scanning and subsequent 250 keV N2+ ion beam irradiation. When a Teflon surface is irradiated using only an N2+ ion beam, micro-protrusions are densely formed in the irradiated area. It has been previously confirmed that these protrusions aid the attachment of biological cells, which then spread on the surface. Therefore, modification of the Teflon surface patterning is necessary in order to enhance its functionality as cell culture substrata. In this study, flat areas and depressed structures were created among the dense micro-protrusions by bubbles that were generated inside the sample using proton beam scanning. This modification will contribute to the fabrication of cell culture dishes with the advantages of micro-protrusions.

  17. Micro-CT of sea urchin ossicles supplemented with microbeam diffraction

    Science.gov (United States)

    Stock, Stuart R.; Ignatiev, Konstantin I.; Veis, Arthur; De Carlo, Francesco; Almer, J. D.

    2004-10-01

    Sea urchins employ as wide a range of composite reinforcement strategies as are seen in engineering composites. Besides tailoring reinforcement morphology and alignment to the functional demands of position, solid solution strengthening (high Mg calcite), inclusion toughening (macromolecules), functional gradients in mineral reinforcement morphology, composition and dimensions and mineral interface tailoring are other tactics important to achieving high toughness and high strength in sea urchin teeth. Teeth from different echinoid families illustrate combinations of reinforcement parameters and toughening mechanisms providing good functionality, a virtual probe of the available design space. This paper focuses on a multi-mode x-ray investigation of sea urchin teeth studied on scales approaching 1 μm in millimeter-sized samples, in particular mapping 3-D microarchitecture with synchrotron and laboratory microCT and mapping Ca1-xMgxCO3 crystal composition x and microstrain and crystallite size via microbeam diffraction.

  18. Nuclear micro-beam analysis of deuterium distribution in carbon fibre composites for controlled fusion devices

    International Nuclear Information System (INIS)

    Petersson, P.; Kreter, A.; Possnert, G.; Rubel, M.

    2010-01-01

    Probes made of carbon fibre composite NB41 were exposed to deuterium plasmas in the TEXTOR tokamak and in a simulator of plasma-wall interactions, PISCES. The aim was to assess the deuterium retention and its lateral and depth distribution. The analysis was performed by means of D( 3 He, p) 4 He and 12 C( 3 He, p) 14 N nuclear reactions analysis using a standard (1 mm spot) and micro-beam (20 μm resolution). The measurements have revealed non uniform distribution of deuterium atoms in micro-regions: differences by a factor of 3 between the maximum and minimum deuterium concentrations. The differences were associated with the orientation and type of fibres for samples exposed in PICSES. For surface structure in the erosion zone of samples exposed to a tokamak plasma the micro-regions were more complex. Depth profiling has indicated migration of fuel into the bulk of materials.

  19. Flexoelectric Effect on Vibration of Piezoelectric Microbeams Based on a Modified Couple Stress Theory

    Directory of Open Access Journals (Sweden)

    Xingjia Li

    2017-01-01

    Full Text Available A novel electric Gibbs function was proposed for the piezoelectric microbeams (PMBs by employing a modified couple stress theory. Based on the new Gibbs function and the Euler-Bernoulli beam theory, the governing equations which incorporate the effects of couple stress, flexoelectricity, and piezoelectricity were derived for the mechanics of PMBs. The analysis of the effective bending rigidity shows the effects of size and flexoelectricity can greaten the stiffness of PMBs so that the natural frequency increases significantly compared with the Euler-Bernoulli beam, and then the mechanical and electrical properties of PMBs are enhanced compared to the classical beam. This study can guide the design of microscale piezoelectric/flexoelectric structures which may find potential applications in the microelectromechanical systems (MEMS.

  20. Heavy ion microbeam studies of diffusion time resolved charge collection from p-n junctions

    International Nuclear Information System (INIS)

    Guo, B.N.; El Bouanani, M.; Duggan, J.L.; McDaniel, F.D.; Renfrow, S.N.; Walsh, D.S.; Doyle, B.L.

    2001-01-01

    The knowledge of (diffusion, drift, and funneling assisted) charge collection within electronic devices is essential to design radiation hardened Integrated Circuits (ICs). In the present work, diffusion time resolved charge collection studies were performed on stripe-like junctions using 12 MeV carbon and 28 MeV silicon microbeams and MEDICI simulation calculations. The relative average arrival time of the diffused charge on the junctions was measured along with the amount of charge collection by the junctions. The average arrival time of the diffused charge is related to the first moment (or the average time) of the arrival carrier density on the junction. The experimental results and MEDICI (a 2D-device simulator) calculations support this interpretation. These results show the importance of the diffusive charge collection by junctions, which is especially significant in accounting for Single Event Upsets (SEUs) and Multiple Bit Upset (MBUs) in digital devices

  1. Piezoelectric transduction of flexural modes in pre-stressed microbeam resonators

    Science.gov (United States)

    Torri, G. B.; Janssen, N. M. A.; Zeng, Z.; Rottenberg, X.; Karabacak, D. M.; Vandecasteele, M.; Van Hoof, C.; Puers, R.; Tilmans, H. A. C.

    2014-08-01

    This paper reports on the optimization of the design of piezoelectric transducer elements integrated on doubly-clamped microbeam resonators utilized as (bio)chemical sensors. We report and emphasize the often forgotten influence of membrane stresses on defining the dimensions and optimal position of the piezoelectric transducer elements. The study takes into account stress induced structural changes and provides models for the equivalent motional parameters of resonators with particular shapes of the transducers matching the flexural modes of vibration. The above is analyzed theoretically using numerical models and is confirmed by impedance measurements and optical measurements of fabricated doubly-clamped beam resonators. We propose various transducer designs and highlight the advantages of using higher order vibration modes by implementing specially designed mode matching transducer elements. It is concluded that the paper describes and highlights the importance of accounting for the membrane stresses to optimize the resonator performance and the low power in electronic feedback of resonating sensing systems.

  2. Ion microbeam analysis. Application to the study of the skin barrier and its nano-toxicology

    International Nuclear Information System (INIS)

    Simon, M.

    2009-12-01

    This work is dedicated to the use of ion microbeam irradiation to the study of a complex biological tissue like skin. Up to now, it has been very difficult to detect and track metallic oxides and manufactured nano-particles in biological tissues, most particularly in skin. Thus, it is essential to precise the mechanisms involved in skin barrier function processes face to exogenous agents like nano-particles and to characterize them in biological models in vitro/in vivo. During my work, I have had the opportunity to combine quantitative methods of analysis with high resolution imagery techniques (confocal microscopy, transmission electron microscopy and ion beam analysis) in order to characterize: (i) the skin barrier function of an ex vivo pig ear skin model understanding the ion homeostasis behavior face to different chemical or physical stresses; (ii) the impact on viability, accumulation and intracellular distribution of nano-particles (Titanium Oxides) naked or functionalized with fluorescent dyes (FITC, Rhodamine)

  3. Influence of the environment and phototoxicity of the live cell imaging system at IMP microbeam facility

    Science.gov (United States)

    Liu, Wenjing; Du, Guanghua; Guo, Jinlong; Wu, Ruqun; Wei, Junzhe; Chen, Hao; Li, Yaning; Zhao, Jing; Li, Xiaoyue

    2017-08-01

    To investigate the spatiotemporal dynamics of DNA damage and repair after the ion irradiation, an online live cell imaging system has been established based on the microbeam facility at Institute of Modern Physics (IMP). The system could provide a sterile and physiological environment by making use of heating plate and live cell imaging solution. The phototoxicity was investigated through the evaluation of DNA repair protein XRCC1 foci formed in HT1080-RFP cells during the imaging exposure. The intensity of the foci induced by phototoxicity was much lower compared with that of the foci induced by heavy ion hits. The results showed that although spontaneous foci were formed due to RFP exposure during live cell imaging, they had little impact on the analysis of the recruitment kinetics of XRCC1 in the foci induced by the ion irradiation.

  4. Microscopic stress characterisation of functional iron-based alloys by white X-ray microbeam diffraction

    Science.gov (United States)

    Kwon, E. P.; Sato, S.; Fujieda, S.; Shinoda, K.; Kajiwara, K.; Sato, M.; Suzuki, S.

    2018-01-01

    Microscopic residual stress evolution in an austenite (γ) grain during a shape-memory process in an Fe-Mn-Si-Cr alloy was investigated using the white X-ray microbeam diffraction technique. The stresses were measured on a coarse grain, which had an orientation near , parallel to the tensile loading direction with a high Schmid factor for a martensitic transformation. The magnitude of the residual stresses in a grain of the sample, which was subjected to a 23 % tensile strain and subsequent shape-recovery heating, was found to be very small and comparable to that prior to tensile deformation. Measurements of the recovery strain and microstructural analyses using electron backscatter diffraction suggested that the low residual stresses could be attributed to the significant shape recovery caused by a highly reversible martensitic transformation in the grain with a particular orientation.

  5. SNP Arrays

    Directory of Open Access Journals (Sweden)

    Jari Louhelainen

    2016-10-01

    Full Text Available The papers published in this Special Issue “SNP arrays” (Single Nucleotide Polymorphism Arrays focus on several perspectives associated with arrays of this type. The range of papers vary from a case report to reviews, thereby targeting wider audiences working in this field. The research focus of SNP arrays is often human cancers but this Issue expands that focus to include areas such as rare conditions, animal breeding and bioinformatics tools. Given the limited scope, the spectrum of papers is nothing short of remarkable and even from a technical point of view these papers will contribute to the field at a general level. Three of the papers published in this Special Issue focus on the use of various SNP array approaches in the analysis of three different cancer types. Two of the papers concentrate on two very different rare conditions, applying the SNP arrays slightly differently. Finally, two other papers evaluate the use of the SNP arrays in the context of genetic analysis of livestock. The findings reported in these papers help to close gaps in the current literature and also to give guidelines for future applications of SNP arrays.

  6. X-ray microbeam stand-alone facility for cultured cells irradiation

    International Nuclear Information System (INIS)

    Bożek, Sebastian; Bielecki, Jakub; Wiecheć, Anna; Lekki, Janusz; Stachura, Zbigniew; Pogoda, Katarzyna; Lipiec, Ewelina; Tkocz, Konrad; Kwiatek, Wojciech M.

    2017-01-01

    Highlights: • An X-ray microbeam line for irradiation of living cultured cells was constructed. • A step by step explanation of working principles with engineering details, procedures and calculations is presented. • A model of beam and cell interaction is presented. • A method of uniform irradiation of living cells with an exact dose per a cell is presented. • Results of preliminary experiments are presented. - Abstract: The article describes an X-ray microbeam standalone facility dedicated for irradiation of living cultured cells. The article can serve as an advice for such facilities construction, as it begins from engineering details, through mathematical modeling and experimental procedures, ending up with preliminary experimental results and conclusions. The presented system consists of an open type X-ray tube with microfocusing down to about 2 μm, an X-ray focusing system with optical elements arranged in the nested Kirckpatrick-Baez (or Montel) geometry, a sample stand and an optical microscope with a scientific digital CCD camera. For the beam visualisation an X-ray sensitive CCD camera and a spectral detector are used, as well as a scintillator screen combined with the microscope. A method of precise one by one irradiation of previously chosen cells is presented, as well as a fast method of uniform irradiation of a chosen sample area. Mathematical models of beam and cell with calculations of kerma and dose are presented. The experiments on dose-effect relationship, kinetics of DNA double strand breaks repair, as well as micronuclei observation were performed on PC-3 (Prostate Cancer) cultured cells. The cells were seeded and irradiated on Mylar foil, which covered a hole drilled in the Petri dish. DNA lesions were visualised with γ-H2AX marker combined with Alexa Fluor 488 fluorescent dye.

  7. An ultra-thin Schottky diode as a transmission particle detector for biological microbeams

    International Nuclear Information System (INIS)

    Grad, M; Harken, A; Randers-Pehrson, G; Brenner, D J; Attinger, D

    2012-01-01

    We fabricated ultrathin metal-semiconductor Schottky diodes for use as transmission particle detectors in the biological microbeam at Columbia University's Radiological Research Accelerator Facility (RARAF). The RARAF microbeam can deliver a precise dose of ionizing radiation in cell nuclei with sub-micron precision. To ensure an accurate delivery of charged particles, the facility currently uses a commercial charged-particle detector placed after the sample. We present here a transmission detector that will be placed between the particle accelerator and the biological specimen, allowing the irradiation of samples that would otherwise block radiation from reaching a detector behind the sample. Four detectors were fabricated with co-planar gold and aluminum electrodes thermally evaporated onto etched n-type crystalline silicon substrates, with device thicknesses ranging from 8.5 μm - 13.5 μm. We show coincident detections and pulse-height distributions of charged particles in both the transmission detector and the commercial detector above it. Detections are demonstrated at a range of operating conditions, including incoming particle type, count rate, and beam location on the detectors. The 13.5 μm detector is shown to work best to detect 2.7 MeV protons (H + ), and the 8.5 μm detector is shown to work best to detect 5.4 MeV alpha particles ( 4 He ++ ). The development of a transmission detector enables a range of new experiments to take place at RARAF on radiation-stopping samples such as thick tissues, targets that need immersion microscopy, and integrated microfluidic devices for handling larger quantities of cells and small organisms.

  8. An ultra-thin Schottky diode as a transmission particle detector for biological microbeams

    Science.gov (United States)

    Harken, Andrew; Randers-Pehrson, Gerhard; Attinger, Daniel; Brenner, David J.

    2013-01-01

    We fabricated ultrathin metal-semiconductor Schottky diodes for use as transmission particle detectors in the biological microbeam at Columbia University’s Radiological Research Accelerator Facility (RARAF). The RARAF microbeam can deliver a precise dose of ionizing radiation in cell nuclei with sub-micron precision. To ensure an accurate delivery of charged particles, the facility currently uses a commercial charged-particle detector placed after the sample. We present here a transmission detector that will be placed between the particle accelerator and the biological specimen, allowing the irradiation of samples that would otherwise block radiation from reaching a detector behind the sample. Four detectors were fabricated with co-planar gold and aluminum electrodes thermally evaporated onto etched n-type crystalline silicon substrates, with device thicknesses ranging from 8.5 μm – 13.5 μm. We show coincident detections and pulse-height distributions of charged particles in both the transmission detector and the commercial detector above it. Detections are demonstrated at a range of operating conditions, including incoming particle type, count rate, and beam location on the detectors. The 13.5 μm detector is shown to work best to detect 2.7 MeV protons (H+), and the 8.5 μm detector is shown to work best to detect 5.4 MeV alpha particles (4He++). The development of a transmission detector enables a range of new experiments to take place at RARAF on radiation-stopping samples such as thick tissues, targets that need immersion microscopy, and integrated microfluidic devices for handling larger quantities of cells and small organisms. PMID:24058378

  9. Applications of high-throughput clonogenic survival assays in high-LET particle microbeams

    Directory of Open Access Journals (Sweden)

    Antonios eGeorgantzoglou

    2016-01-01

    Full Text Available Charged particle therapy is increasingly becoming a valuable tool in cancer treatment, mainly due to the favorable interaction of particle radiation with matter. Its application is still limited due, in part, to lack of data regarding the radiosensitivity of certain cell lines to this radiation type, especially to high-LET particles. From the earliest days of radiation biology, the clonogenic survival assay has been used to provide radiation response data. This method produces reliable data but it is not optimized for high-throughput microbeam studies with high-LET radiation where high levels of cell killing lead to a very low probability of maintaining cells’ clonogenic potential. A new method, therefore, is proposed in this paper, which could potentially allow these experiments to be conducted in a high-throughput fashion. Cells are seeded in special polypropylene dishes and bright-field illumination provides cell visualization. Digital images are obtained and cell detection is applied based on corner detection, generating individual cell targets as x-y points. These points in the dish are then irradiated individually by a micron field size high-LET microbeam. Post-irradiation, time-lapse imaging follows cells’ response. All irradiated cells are tracked by linking trajectories in all time-frames, based on finding their nearest position. Cell divisions are detected based on cell appearance and individual cell temporary corner density. The number of divisions anticipated is low due to the high probability of cell killing from high-LET irradiation. Survival curves are produced based on cell’s capacity to divide at least 4-5 times. The process is repeated for a range of doses of radiation. Validation shows the efficiency of the proposed cell detection and tracking method in finding cell divisions.

  10. Applications of High-Throughput Clonogenic Survival Assays in High-LET Particle Microbeams.

    Science.gov (United States)

    Georgantzoglou, Antonios; Merchant, Michael J; Jeynes, Jonathan C G; Mayhead, Natalie; Punia, Natasha; Butler, Rachel E; Jena, Rajesh

    2015-01-01

    Charged particle therapy is increasingly becoming a valuable tool in cancer treatment, mainly due to the favorable interaction of particle radiation with matter. Its application is still limited due, in part, to lack of data regarding the radiosensitivity of certain cell lines to this radiation type, especially to high-linear energy transfer (LET) particles. From the earliest days of radiation biology, the clonogenic survival assay has been used to provide radiation response data. This method produces reliable data but it is not optimized for high-throughput microbeam studies with high-LET radiation where high levels of cell killing lead to a very low probability of maintaining cells' clonogenic potential. A new method, therefore, is proposed in this paper, which could potentially allow these experiments to be conducted in a high-throughput fashion. Cells are seeded in special polypropylene dishes and bright-field illumination provides cell visualization. Digital images are obtained and cell detection is applied based on corner detection, generating individual cell targets as x-y points. These points in the dish are then irradiated individually by a micron field size high-LET microbeam. Post-irradiation, time-lapse imaging follows cells' response. All irradiated cells are tracked by linking trajectories in all time-frames, based on finding their nearest position. Cell divisions are detected based on cell appearance and individual cell temporary corner density. The number of divisions anticipated is low due to the high probability of cell killing from high-LET irradiation. Survival curves are produced based on cell's capacity to divide at least four to five times. The process is repeated for a range of doses of radiation. Validation shows the efficiency of the proposed cell detection and tracking method in finding cell divisions.

  11. X-ray microbeam stand-alone facility for cultured cells irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bożek, Sebastian, E-mail: sebastian.bozek@yahoo.com [Jagiellonian University Medical College, Department of Pharmaceutical Biophysics, Krakow (Poland); Bielecki, Jakub; Wiecheć, Anna; Lekki, Janusz; Stachura, Zbigniew; Pogoda, Katarzyna; Lipiec, Ewelina; Tkocz, Konrad; Kwiatek, Wojciech M. [Institute of Nuclear Physics Polish Academy of Sciences, PL-31342 Krakow (Poland)

    2017-03-01

    Highlights: • An X-ray microbeam line for irradiation of living cultured cells was constructed. • A step by step explanation of working principles with engineering details, procedures and calculations is presented. • A model of beam and cell interaction is presented. • A method of uniform irradiation of living cells with an exact dose per a cell is presented. • Results of preliminary experiments are presented. - Abstract: The article describes an X-ray microbeam standalone facility dedicated for irradiation of living cultured cells. The article can serve as an advice for such facilities construction, as it begins from engineering details, through mathematical modeling and experimental procedures, ending up with preliminary experimental results and conclusions. The presented system consists of an open type X-ray tube with microfocusing down to about 2 μm, an X-ray focusing system with optical elements arranged in the nested Kirckpatrick-Baez (or Montel) geometry, a sample stand and an optical microscope with a scientific digital CCD camera. For the beam visualisation an X-ray sensitive CCD camera and a spectral detector are used, as well as a scintillator screen combined with the microscope. A method of precise one by one irradiation of previously chosen cells is presented, as well as a fast method of uniform irradiation of a chosen sample area. Mathematical models of beam and cell with calculations of kerma and dose are presented. The experiments on dose-effect relationship, kinetics of DNA double strand breaks repair, as well as micronuclei observation were performed on PC-3 (Prostate Cancer) cultured cells. The cells were seeded and irradiated on Mylar foil, which covered a hole drilled in the Petri dish. DNA lesions were visualised with γ-H2AX marker combined with Alexa Fluor 488 fluorescent dye.

  12. Analysis of strain error sources in micro-beam Laue diffraction

    International Nuclear Information System (INIS)

    Hofmann, Felix; Eve, Sophie; Belnoue, Jonathan; Micha, Jean-Sébastien; Korsunsky, Alexander M.

    2011-01-01

    Micro-beam Laue diffraction is an experimental method that allows the measurement of local lattice orientation and elastic strain within individual grains of engineering alloys, ceramics, and other polycrystalline materials. Unlike other analytical techniques, e.g. based on electron microscopy, it is not limited to surface characterisation or thin sections, but rather allows non-destructive measurements in the material bulk. This is of particular importance for in situ loading experiments where the mechanical response of a material volume (rather than just surface) is studied and it is vital that no perturbation/disturbance is introduced by the measurement technique. Whilst the technique allows lattice orientation to be determined to a high level of precision, accurate measurement of elastic strains and estimating the errors involved is a significant challenge. We propose a simulation-based approach to assess the elastic strain errors that arise from geometrical perturbations of the experimental setup. Using an empirical combination rule, the contributions of different geometrical uncertainties to the overall experimental strain error are estimated. This approach was applied to the micro-beam Laue diffraction setup at beamline BM32 at the European Synchrotron Radiation Facility (ESRF). Using a highly perfect germanium single crystal, the mechanical stability of the instrument was determined and hence the expected strain errors predicted. Comparison with the actual strain errors found in a silicon four-point beam bending test showed good agreement. The simulation-based error analysis approach makes it possible to understand the origins of the experimental strain errors and thus allows a directed improvement of the experimental geometry to maximise the benefit in terms of strain accuracy.

  13. In vivo pink-beam imaging and fast alignment procedure for rat brain lesion microbeam radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Serduc, Raphaël, E-mail: raph.serduc@gmail.com; Berruyer, Gilles; Brochard, Thierry; Renier, Michel; Nemoz, Christian [European Synchrotron Radiation Facility, F38043 Grenoble (France)

    2010-05-01

    A fast 50 µm-accuracy alignment procedure has been developed for the radiosurgery of brain lesions in rats, using microbeam radiation therapy. A fast 50 µm-accuracy alignment procedure has been developed for the radiosurgery of brain lesions in rats, using microbeam radiation therapy. In vivo imaging was performed using the pink beam (35–60 keV) produced by the ID17 wiggler at the ESRF opened at 120 mm and filtered. A graphical user interface has been developed in order to define the irradiation field size and to position the target with respect to the skull structures observed in X-ray images. The method proposed here allows tremendous time saving by skipping the swap from white beam to monochromatic beam and vice versa. To validate the concept, the somatosensory cortex or thalamus of GAERS rats were irradiated under several ports using this alignment procedure. The magnetic resonance images acquired after contrast agent injection showed that the irradiations were selectively performed in these two expected brain regions. Image-guided microbeam irradiations have therefore been realised for the first time ever, and, thanks to this new development, the ID17 biomedical beamline provides a major tool allowing brain radiosurgery trials on animal patients.

  14. Continuous observation of polarization effects in thin SC-CVD diamond detector designed for heavy ion microbeam measurement

    Energy Technology Data Exchange (ETDEWEB)

    Kada, Wataru, E-mail: kada.wataru@gunma-u.ac.jp [Faculty of Science and Technology, Gunma University, 1-5-1 Tenjin-machi, Kiryu, Gunma 376-8515 (Japan); Iwamoto, Naoya [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Satoh, Takahiro [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Onoda, Shinobu [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Grilj, Veljko; Skukan, Natko [Ruđer Bošković Institute, P.O. Box 1016, 10001 Zagreb (Croatia); Koka, Masashi [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Ohshima, Takeshi [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Jakšić, Milko [Ruđer Bošković Institute, P.O. Box 1016, 10001 Zagreb (Croatia); Kamiya, Tomihiro [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan)

    2014-07-15

    Continuous irradiation effects on a thin-film diamond detector were investigated for the utilization of these films as a detector for heavy ion microbeams. Temporal signal degradation in the energy spectrum was frequently observed during the focused heavy ion microbeam irradiation. To measure the temporal response to the each ion incidents, focused heavy ion microbeam with different beam fluence rates were irradiated to a single crystal (SC)-CVD diamond film detector with thickness of 50 μm. The responses to each ion were continuously observed and characterized by ion beam-induced charge (IBIC) measurement system. Heavy ions with short penetration path in diamond generate the large difference in mean path of electrons and holes, which is inverted by changing bias polarity. Signal degradation condition was relied on the bias polarity under the irradiation of heavy ions with short penetration length in the diamond. The continuous observation of IBIC signals revealed that temporal degradation in pulse height of signals, so called polarization effects, seems to be mainly caused by the hole trapping in this diamond crystal.

  15. Filter arrays

    Energy Technology Data Exchange (ETDEWEB)

    Page, Ralph H.; Doty, Patrick F.

    2017-08-01

    The various technologies presented herein relate to a tiled filter array that can be used in connection with performance of spatial sampling of optical signals. The filter array comprises filter tiles, wherein a first plurality of filter tiles are formed from a first material, the first material being configured such that only photons having wavelengths in a first wavelength band pass therethrough. A second plurality of filter tiles is formed from a second material, the second material being configured such that only photons having wavelengths in a second wavelength band pass therethrough. The first plurality of filter tiles and the second plurality of filter tiles can be interspersed to form the filter array comprising an alternating arrangement of first filter tiles and second filter tiles.

  16. WE-E-BRE-06: High-Dose Microbeam Radiation Induces Different Responses in Tumor Microenvironment Compared to Conventional Seamless Radiation in Window Chamber Tumor Models

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S; Zhang, J; Hadsell, M [UNC School of Medicine, Chapel Hill, NC (United States); Fontanella, A; Schroeder, T; Palmer, G; Dewhirst, M [Duke University, Durham, NC (United States); Boss, M [North Carolina State University, Raleigh, NC (United States); Berman, K [School of Veterinary Medicine, University of Glasgow, Glasgow, Scotland (United Kingdom)

    2014-06-15

    Purpose: Microbeam radiation therapy and GRID therapy are different forms of Spatially-Fractioned Radiation Therapy (SFRT) that is fundamentally different from the conventional seamless and temporally fractionated radiation therapy. SFRT is characterized by a ultra-high dose (10s –100s Gy) dose single treatment with drastic inhomogeneity pattern of given spatial frequencies. Preclinical and limited clinical studies have shown that the SFRT treatments may offer significant improvements in reducing treatment toxicity, especially for those patients who have not benefited from the state-of-the-art radiation therapy approaches. This preliminary study aims to elucidate the underlying working mechanisms of SFRT, which currently remains poorly understood. Methods: A genetically engineered 4T1 murine mammary carcinoma cell line and nude mice skin fold window chamber were used. A nanotechnology-based 160kV x-ray irradiator delivered 50Gy (entrance dose) single treatments of microbeam or seamless radiation. Animals were in 3 groups: mock, seamless radiation, and 300μm microbeam radiation. The windows were imaged using a hyperspectral system to capture total hemoglobin/saturation, GFP fluorescence emission, RFP fluorescence emission, and vessel density at 9 time points up to 7 days post radiation. Results: We found unique physiologic changes in different tumor/normal tissue regions and differential effects between seamless and microbeam treatments. They include 1) compared to microbeam and mock radiation seamless radiation damaged more microvasculature in tumor-surrounding normal tissue, 2) a pronounced angiogenic effect was observed with vascular proliferation in the microbeam irradiated portion of the tumor days post treatment (no such effect observed in seamless and mock groups), and 3) a notable change in tumor vascular orientation was observed where vessels initially oriented parallel to the beam length were replaced by vessels running perpendicular to the irradiation

  17. The role of sleep difficulties in the vasomotor menopausal symptoms and depressed mood relationships: an international pooled analysis of eight studies in the InterLACE consortium.

    Science.gov (United States)

    Chung, Hsin-Fang; Pandeya, Nirmala; Dobson, Annette J; Kuh, Diana; Brunner, Eric J; Crawford, Sybil L; Avis, Nancy E; Gold, Ellen B; Mitchell, Ellen S; Woods, Nancy F; Bromberger, Joyce T; Thurston, Rebecca C; Joffe, Hadine; Yoshizawa, Toyoko; Anderson, Debra; Mishra, Gita D

    2018-02-12

    Many women experience both vasomotor menopausal symptoms (VMS) and depressed mood at midlife, but little is known regarding the prospective bi-directional relationships between VMS and depressed mood and the role of sleep difficulties in both directions. A pooled analysis was conducted using data from 21 312 women (median: 50 years, interquartile range 49-51) in eight studies from the InterLACE consortium. The degree of VMS, sleep difficulties, and depressed mood was self-reported and categorised as never, rarely, sometimes, and often (if reporting frequency) or never, mild, moderate, and severe (if reporting severity). Multivariable logistic regression models were used to examine the bi-directional associations adjusted for within-study correlation. At baseline, the prevalence of VMS (40%, range 13-62%) and depressed mood (26%, 8-41%) varied substantially across studies, and a strong dose-dependent association between VMS and likelihood of depressed mood was found. Over 3 years of follow-up, women with often/severe VMS at baseline were more likely to have subsequent depressed mood compared with those without VMS (odds ratios (OR) 1.56, 1.27-1.92). Women with often/severe depressed mood at baseline were also more likely to have subsequent VMS than those without depressed mood (OR 1.89, 1.47-2.44). With further adjustment for the degree of sleep difficulties at baseline, the OR of having a subsequent depressed mood associated with often/severe VMS was attenuated and no longer significant (OR 1.13, 0.90-1.40). Conversely, often/severe depressed mood remained significantly associated with subsequent VMS (OR 1.80, 1.38-2.34). Difficulty in sleeping largely explained the relationship between VMS and subsequent depressed mood, but it had little impact on the relationship between depressed mood and subsequent VMS.

  18. Preparation of single rice chromosome for construction of a DNA library using a laser microbeam trap.

    Science.gov (United States)

    Liu, Xiaohui; Wang, Haowei; Li, Yinmei; Tang, Yesheng; Liu, Yilei; Hu, Xin; Jia, Peixin; Ying, Kai; Feng, Qi; Guan, Jianping; Jin, Chaoqing; Zhang, Lei; Lou, Liren; Zhou, Zhuan; Han, Bin

    2004-04-29

    We report the development of a laser micromanipulation system and its application in the isolation of individual rice chromosomes directly from a metaphase cell. Microdissection and flow sorting are two major methods for the isolation of single chromosome. These methods are dependent on the techniques of chromosome spread and chromosome suspension, respectively. In the development of this system, we avoided using chromosome spread and cell suspension was used instead. The cell wall of metaphase rice cell was cut by optical scissors. The released single chromosome was captured by an optical trap and transported to an area without cell debris. The isolated single chromosome was then collected and specific library was constructed by linker adaptor PCR. The average insert size of the library was about 300 bp. Two hundred inserts of chromosome 4 library were sequenced, and 96.5% were aligned to the corresponding sequences of rice chromosome 4. These results suggest the possible application of this method for the preparation of other subcellular structures and for the cloning of single macromolecule through a laser microbeam trap.

  19. Higher order modes excitation of electrostatically actuated clamped–clamped microbeams: experimental and analytical investigation

    KAUST Repository

    Jaber, Nizar

    2016-01-06

    © 2016 IOP Publishing Ltd. In this study, we demonstrate analytically and experimentally the excitations of the higher order modes of vibrations in electrostatically actuated clamped-clamped microbeam resonators. The concept is based on using partial electrodes with shapes that induce strong excitation of the mode of interest. The devices are fabricated using polyimide as a structural layer coated with nickel from the top and chrome and gold layers from the bottom. Experimentally, frequency sweeps with different electro-dynamical loading conditions are shown to demonstrate the excitation of the higher order modes of vibration. Using a half electrode, the second mode is excited with high amplitude of vibration compared with almost zero response using the full electrode. Also, using a two-third electrode configuration is shown to amplify the third mode resonance amplitude compared with the full electrode under the same electrical loading conditions. An analytical model is developed based on the Euler-Bernollui beam model and the Galerkin method to simulate the device response. Good agreement between the simulation results and the experimental data is reported.

  20. Biological studies using mammalian cell lines and the current status of the microbeam irradiation system, SPICE

    Science.gov (United States)

    Konishi, T.; Ishikawa, T.; Iso, H.; Yasuda, N.; Oikawa, M.; Higuchi, Y.; Kato, T.; Hafer, K.; Kodama, K.; Hamano, T.; Suya, N.; Imaseki, H.

    2009-06-01

    The development of SPICE (single-particle irradiation system to cell), a microbeam irradiation system, has been completed at the National Institute of Radiological Sciences (NIRS). The beam size has been improved to approximately 5 μm in diameter, and the cell targeting system can irradiate up to 400-500 cells per minute. Two cell dishes have been specially designed: one a Si 3N 4 plate (2.5 mm × 2.5 mm area with 1 μm thickness) supported by a 7.5 mm × 7.5 mm frame of 200 μm thickness, and the other a Mylar film stretched by pressing with a metal ring. Both dish types may be placed on a voice coil stage equipped on the cell targeting system, which includes a fluorescent microscope and a CCD camera for capturing cell images. This microscope system captures images of dyed cell nuclei, computes the location coordinates of individual cells, and synchronizes this with the voice coil motor stage and single-particle irradiation system consisting of a scintillation counter and a beam deflector. Irradiation of selected cells with a programmable number of protons is now automatable. We employed the simultaneous detection method for visualizing the position of mammalian cells and proton traversal through CR-39 to determine whether the targeted cells are actually irradiated. An immuno-assay was also performed against γ-H2AX, to confirm the induction of DNA double-strand breaks in the target cells.

  1. Biological studies using mammalian cell lines and the current status of the microbeam irradiation system, SPICE

    International Nuclear Information System (INIS)

    Konishi, T.; Ishikawa, T.; Iso, H.; Yasuda, N.; Oikawa, M.; Higuchi, Y.; Kato, T.; Hafer, K.; Kodama, K.; Hamano, T.; Suya, N.; Imaseki, H.

    2009-01-01

    The development of SPICE (single-particle irradiation system to cell), a microbeam irradiation system, has been completed at the National Institute of Radiological Sciences (NIRS). The beam size has been improved to approximately 5 μm in diameter, and the cell targeting system can irradiate up to 400-500 cells per minute. Two cell dishes have been specially designed: one a Si 3 N 4 plate (2.5 mm x 2.5 mm area with 1 μm thickness) supported by a 7.5 mm x 7.5 mm frame of 200 μm thickness, and the other a Mylar film stretched by pressing with a metal ring. Both dish types may be placed on a voice coil stage equipped on the cell targeting system, which includes a fluorescent microscope and a CCD camera for capturing cell images. This microscope system captures images of dyed cell nuclei, computes the location coordinates of individual cells, and synchronizes this with the voice coil motor stage and single-particle irradiation system consisting of a scintillation counter and a beam deflector. Irradiation of selected cells with a programmable number of protons is now automatable. We employed the simultaneous detection method for visualizing the position of mammalian cells and proton traversal through CR-39 to determine whether the targeted cells are actually irradiated. An immuno-assay was also performed against γ-H2AX, to confirm the induction of DNA double-strand breaks in the target cells.

  2. Synchrotron X-ray micro-beam studies of ancient Egyptian make-up

    International Nuclear Information System (INIS)

    Martinetto, P.; Anne, M.; Dooryhee, E.; Drakopoulos, M.; Dubus, M.; Salomon, J.; Simionovici, A.; Walter, Ph.

    2001-01-01

    Vases full of make-up are most often present in the burial furniture of Egyptian tombs dated from the pharaonic period. The powdered cosmetics made of isolated grains are analysed to identify their trace element signature. From this signature we identify the provenance of the mineral ingredients in the make-up and we observe different impurities in products, which have been demonstrated as synthetic substances by previous works. Focused X-ray micro-beam (2x5 μm 2 ) is successively tuned at 11 keV, below the L III absorption edge of Pb, and 31.8 keV for global characterisation of the metal impurities. The fluorescence signal integrated over each single grain is detected against the X-ray micro-diffraction pattern collected in transmission with a bi-dimensional detector. Furthermore, for galena grains rich in Zn, the XANES signal at the K-absorption edge of Zn shows its immediate nearest-neighbour environment

  3. Study of a new portable x-ray source with micro-beam

    Science.gov (United States)

    Wang, Kaige; Li, Ji; Yang, Qinlao; Guo, Jinchuan; Guo, Baoping; Kuo, Xiaomei; Zhou, Junlan; Niu, Hanben

    2006-02-01

    A novel X-ray source with micro-beam has been studied in theory and experiment. The source is composed of three portions: LaB 6 crystal cathode electron gun emitting system, electrostatic focusing system, and permutable metal target system. The electronic current emitted by the electron-gun are controlled by modulating cathode temperature and Wehnelt grid voltage and ratio D w/H, two-equal-radius-cylinder-electrodes focusing system concentrates electron beam, the X-ray photons are irradiated by high energy electron beam bombarding the metal target. The new x-ray source's general-purpose capabilities such as continuous radiation and pulse radiation, focus size and luminance, are also tested. When the temperature of LaB6 cathode is about 1900K and partial pressures being kept below 10 -7 torr, the minimal focus diameter is merely about 10 microns. The new micro focus x-ray source has other lots of advantages such as economy, safety and facility.

  4. A Microbeam Resonator with Partial Electrodes for Logic and Memory Elements

    KAUST Repository

    Hafiz, Md Abdullah Al

    2017-11-10

    We demonstrate logic and memory elements based on an in-plane clamped-clamped microbeam resonator. The micro-resonator is electrostatically actuated through a drive electrode and the motional signal is capacitively sensed at a sense electrode, while the resonance characteristics are modulated by DC voltage pulses provided at two separate partial electrodes, independent of the drive/sense electrodes. For the logic applications, we use two separate electrodes to provide DC voltages defined as the logic inputs. The high (low) motional signal at on-resonance (off-resonance) state is defined as the logic output state “1” (“0”). For the memory operation, two stable vibrational states, high and low, within the hysteretic regime are defined as the memory states, “1” and “0”, respectively. We take advantage of the split electrode configuration to provide positive and negative DC voltage pulses selectively to set/reset the memory states (“1”/“0”) without affecting the driving and sensing terminals. Excluding the energy cost for supporting electronics, these devices consume energy in 10’s of picojoules per logic/memory operations. Furthermore, the devices are fabricated using silicon on insulator (SOI) wafers, have the potential for on-chip integration, and operate at moderate pressure (~1 Torr) and room temperature.

  5. Comparison of proton microbeam and gamma irradiation for the radiation hardness testing of silicon PIN diodes

    Science.gov (United States)

    Jakšić, M.; Grilj, V.; Skukan, N.; Majer, M.; Jung, H. K.; Kim, J. Y.; Lee, N. H.

    2013-09-01

    Simple and cost-effective solutions using Si PIN diodes as detectors are presently utilized in various radiation-related applications in which excessive exposure to radiation degrades their charge transport properties. One of the conventional methods for the radiation hardness testing of such devices is time-consuming irradiation with electron beam or gamma-ray irradiation facilities, high-energy proton accelerators, or with neutrons from research reactors. Recently, for the purpose of radiation hardness testing, a much faster nuclear microprobe based approach utilizing proton irradiation has been developed. To compare the two different irradiation techniques, silicon PIN diodes have been irradiated with a Co-60 gamma radiation source and with a 6 MeV proton microbeam. The signal degradation in the silicon PIN diodes for both irradiation conditions has been probed by the IBIC (ion beam induced charge) technique, which can precisely monitor changes in charge collection efficiency. The results presented are reviewed on the basis of displacement damage calculations and NIEL (non-ionizing energy loss) concept.

  6. Diffraction cartography: applying microbeams to macromolecular crystallography sample evaluation and data collection.

    Science.gov (United States)

    Bowler, Matthew W; Guijarro, Matias; Petitdemange, Sebastien; Baker, Isabel; Svensson, Olof; Burghammer, Manfred; Mueller-Dieckmann, Christoph; Gordon, Elspeth J; Flot, David; McSweeney, Sean M; Leonard, Gordon A

    2010-08-01

    Crystals of biological macromolecules often exhibit considerable inter-crystal and intra-crystal variation in diffraction quality. This requires the evaluation of many samples prior to data collection, a practice that is already widespread in macromolecular crystallography. As structural biologists move towards tackling ever more ambitious projects, new automated methods of sample evaluation will become crucial to the success of many projects, as will the availability of synchrotron-based facilities optimized for high-throughput evaluation of the diffraction characteristics of samples. Here, two examples of the types of advanced sample evaluation that will be required are presented: searching within a sample-containing loop for microcrystals using an X-ray beam of 5 microm diameter and selecting the most ordered regions of relatively large crystals using X-ray beams of 5-50 microm in diameter. A graphical user interface developed to assist with these screening methods is also presented. For the case in which the diffraction quality of a relatively large crystal is probed using a microbeam, the usefulness and implications of mapping diffraction-quality heterogeneity (diffraction cartography) are discussed. The implementation of these techniques in the context of planned upgrades to the ESRF's structural biology beamlines is also presented.

  7. Hybrid dose calculation: a dose calculation algorithm for microbeam radiation therapy

    Science.gov (United States)

    Donzelli, Mattia; Bräuer-Krisch, Elke; Oelfke, Uwe; Wilkens, Jan J.; Bartzsch, Stefan

    2018-02-01

    Microbeam radiation therapy (MRT) is still a preclinical approach in radiation oncology that uses planar micrometre wide beamlets with extremely high peak doses, separated by a few hundred micrometre wide low dose regions. Abundant preclinical evidence demonstrates that MRT spares normal tissue more effectively than conventional radiation therapy, at equivalent tumour control. In order to launch first clinical trials, accurate and efficient dose calculation methods are an inevitable prerequisite. In this work a hybrid dose calculation approach is presented that is based on a combination of Monte Carlo and kernel based dose calculation. In various examples the performance of the algorithm is compared to purely Monte Carlo and purely kernel based dose calculations. The accuracy of the developed algorithm is comparable to conventional pure Monte Carlo calculations. In particular for inhomogeneous materials the hybrid dose calculation algorithm out-performs purely convolution based dose calculation approaches. It is demonstrated that the hybrid algorithm can efficiently calculate even complicated pencil beam and cross firing beam geometries. The required calculation times are substantially lower than for pure Monte Carlo calculations.

  8. LabVIEW control software for scanning micro-beam X-ray fluorescence spectrometer.

    Science.gov (United States)

    Wrobel, Pawel; Czyzycki, Mateusz; Furman, Leszek; Kolasinski, Krzysztof; Lankosz, Marek; Mrenca, Alina; Samek, Lucyna; Wegrzynek, Dariusz

    2012-05-15

    Confocal micro-beam X-ray fluorescence microscope was constructed. The system was assembled from commercially available components - a low power X-ray tube source, polycapillary X-ray optics and silicon drift detector - controlled by an in-house developed LabVIEW software. A video camera coupled to optical microscope was utilized to display the area excited by X-ray beam. The camera image calibration and scan area definition software were also based entirely on LabVIEW code. Presently, the main area of application of the newly constructed spectrometer is 2-dimensional mapping of element distribution in environmental, biological and geological samples with micrometer spatial resolution. The hardware and the developed software can already handle volumetric 3-D confocal scans. In this work, a front panel graphical user interface as well as communication protocols between hardware components were described. Two applications of the spectrometer, to homogeneity testing of titanium layers and to imaging of various types of grains in air particulate matter collected on membrane filters, were presented. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Evaluation of support loss in micro-beam resonators: A revisit

    Science.gov (United States)

    Chen, S. Y.; Liu, J. Z.; Guo, F. L.

    2017-12-01

    This paper presents an analytical study on evaluation of support loss in micromechanical resonators undergoing in-plane flexural vibrations. Two-dimensional elastic wave theory is used to determine the energy transmission from the vibrating resonator to the support. Fourier transform and Green's function technique are adopted to solve the problem of wave motions on the surface of the support excited by the forces transmitted by the resonator onto the support. Analytical expressions of support loss in terms of quality factor, taking into account distributed normal stress and shear stress in the attachment region, and coupling between the normal stress and shear stress as well as material disparity between the support and the resonator, have been derived. Effects of geometry of micro-beam resonators, and material dissimilarity between support and resonator on support loss are examined. Numerical results show that 'harder resonator' and 'softer support' combination leads to larger support loss. In addition, the Perfectly Matched Layer (PML) numerical simulation technique is employed for validation of the proposed analytical model. Comparing with results of quality factor obtained by PML technique, we find that the present model agrees well with the results of PML technique and the pure-shear model overestimates support loss noticeably, especially for resonators with small aspect ratio and large material dissimilarity between the support and resonator.

  10. Live cell imaging combined with high-energy single-ion microbeam

    International Nuclear Information System (INIS)

    Guo, Na; Du, Guanghua; Liu, Wenjing; Wu, Ruqun; Wei, Junzhe; Guo, Jinlong; Chen, Hao

    2016-01-01

    DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in the cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10 −3 s −1 and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10 −2 s −1 .

  11. Live cell imaging combined with high-energy single-ion microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Na; Du, Guanghua, E-mail: gh-du@impcas.ac.cn; Liu, Wenjing; Wu, Ruqun; Wei, Junzhe [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China); Guo, Jinlong [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China); Northwest Normal University, Lanzhou (China); Chen, Hao [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China); Institute of Nuclear Science and Technology, University of Lanzhou, Lanzhou (China)

    2016-03-15

    DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in the cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10{sup −3} s{sup −1} and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10{sup −2} s{sup −1}.

  12. Live cell imaging combined with high-energy single-ion microbeam

    Science.gov (United States)

    Guo, Na; Du, Guanghua; Liu, Wenjing; Guo, Jinlong; Wu, Ruqun; Chen, Hao; Wei, Junzhe

    2016-03-01

    DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in the cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10-3 s-1 and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10-2 s-1.

  13. Nuclear microbeam analysis of ICF target material made by GDP technique

    Energy Technology Data Exchange (ETDEWEB)

    Rong, C.; He, X. [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Department of Nuclear Science and Technology, Fudan University, Shanghai 200433 (China); Meng, J., E-mail: eleanor920@163.com [Research Center of Laser Fusion, CAEP, Mianyang 621000 (China); Gao, D. [Research Center of Laser Fusion, CAEP, Mianyang 621000 (China); Zhang, Y.; Li, X.; Lyu, H.; Zhu, Y. [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Department of Nuclear Science and Technology, Fudan University, Shanghai 200433 (China); Zheng, Y. [Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204 (China); Wang, X. [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Department of Nuclear Science and Technology, Fudan University, Shanghai 200433 (China); Shen, H., E-mail: haoshen@fudan.edu.cn [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Department of Nuclear Science and Technology, Fudan University, Shanghai 200433 (China)

    2015-04-01

    Germanium doped carbon–hydrogen polymer (CH) by Glow Discharge Polymer (GDP) technique has become the preferred Inertial Confinement Fusion (ICF) target material. The nondestructive measurement of elements content in the ICF target has become a significant work in recent years. This paper presents the compositional and distributional results of the Germanium doped CH analysis. The Ge doped CH materials as thin film and as hollow sphere were investigated by the Rutherford Backscattering Spectroscopy (RBS) combined with the particle induced X-ray emission (PIXE) and the Elastic Recoil Detection Analysis (ERDA). The samples are thin film with 36 μm thickness and ICF target with 500–2000 μm diameter. The calibration and geometrical arrangement in the analysis of spherical target should be carefully considered in order to acquire accurate results. In the work, the uniformity of the sphere is shown and the ratio of carbon, hydrogen and germanium has been measured. The ratio values are in good agreement with the results obtained by the combustion method. In addition, the difference of the composition from thin film to hollow sphere is also discussed. This work demonstrates that nuclear microbeam analysis is an ideal method to evaluate the ICF target quality.

  14. Alpha-particles microbeam irradiation: impact of reactive oxygen species in bystander effect

    International Nuclear Information System (INIS)

    Hanot, M.

    2008-11-01

    Ionizing radiation-induced bystander effects arise in bystander cells that receive signals from directly irradiated cells. To date, free radicals are believed to play an active role in the bystander response, but this is incompletely characterized. To mark temporal and spatial impacts of bystander effect, we employed a precise α-particle microbeam to target a small fraction of sub-confluent osteoblastic cell cultures (MC3T3-E1). We identified the cellular membrane and mitochondria like two distinct places generating reactive oxygen species. The global oxidative stress observed after irradiation was significantly attenuated after filipin treatment, evidencing the pivotal role of membrane in MC3T3-E1 cells bystander response. To determine impact of bystander effect at a cell level, cellular consequences of this membrane-dependant bystander effect were then investigated. A variable fraction of the cell population (10 to 100%) was individually targeted. In this case, mitotic death and micronuclei yield both increased in bystander cells as well as in targeted cells demonstrating a role of bystander signals between irradiated cells in an autocrine or paracrine manner. Our results indicate a complex interaction of direct irradiation and bystander signals that lead to a membrane-dependant amplification of cell responses. (author)

  15. Tomographic array

    International Nuclear Information System (INIS)

    1976-01-01

    The configuration of a tomographic array in which the object can rotate about its axis is described. The X-ray detector is a cylindrical screen perpendicular to the axis of rotation. The X-ray source has a line-shaped focus coinciding with the axis of rotation. The beam is fan-shaped with one side of this fan lying along the axis of rotation. The detector screen is placed inside an X-ray image multiplier tube

  16. Tomographic array

    International Nuclear Information System (INIS)

    1976-01-01

    A tomographic array with the following characteristics is described. An X-ray screen serving as detector is placed before a photomultiplier tube which itself is placed in front of a television camera connected to a set of image processors. The detector is concave towards the source and is replacable. Different images of the object are obtained simultaneously. Optical fibers and lenses are used for transmission within the system

  17. Characterization of arsenic-contaminated aquifer sediments from eastern Croatia by ion microbeam, PIXE and ICP-OES techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ujević Bošnjak, M., E-mail: magdalena.ujevic@hzjz.hr [Croatian National Institute of Public Health, Rockefelerova 7, 10000 Zagreb (Croatia); Fazinić, S. [Institute Ruđer Bošković, Bijenička cesta, 10000 Zagreb (Croatia); Duić, Ž. [University of Zagreb, Faculty of Mining, Geology and Petroleum Engineering, Pierottijeva 6, Zagreb (Croatia)

    2013-10-01

    Highlights: •ICP-OES and PIXE used in the characterization of As-contaminated sediments. •Observed high correlations between the results obtained by those techniques. •Discrepancies observed for Mn, and for the highest As concentrations. •Microbeam analyses showed As association with sulphides and iron. -- Abstract: Groundwater arsenic contamination has been evidenced in eastern Croatia and hydrochemical results suggest that the occurrence of arsenic in the groundwater depends on the local geology, hydrogeology, and geochemical characteristics of the aquifer. In order to perform the sediment characterization and to investigate arsenic association with the other elements in the sediments, 10 samples from two boreholes (PVc-3 and Gundinci 1) in eastern Croatia were analyzed using two techniques: PIXE (without sample pre-treatment) and ICP-OES (after digestion), as well by ion microbeam analyses. The results of the PIXE and ICP-OES techniques showed quite good agreement; however, greater discrepancies were observed at the higher arsenic and manganese mass ratios. According to both techniques, higher As mass ratios were observed in the sediments from the PVc-3 core (up to 651 mg/kg and 491 mg/kg using PIXE and ICP-OES analyses respectively) than from the Gundinci 1 core (up to 60 mg/kg using both techniques). Although arsenic association with Fe is expected, no correlation was observed. The microbeam analyses demonstrated that arsenic is associated with sulphides and iron in the most As-contaminated sample from the PVc-3 core, while this relationship was not evident in the most As-contaminated sample from the Gundinci 1 borehole.

  18. An electrically actuated imperfect microbeam: Dynamical integrity for interpreting and predicting the device response

    KAUST Repository

    Ruzziconi, Laura

    2013-02-20

    In this study we deal with a microelectromechanical system (MEMS) and develop a dynamical integrity analysis to interpret and predict the experimental response. The device consists of a clamped-clamped polysilicon microbeam, which is electrostatically and electrodynamically actuated. It has non-negligible imperfections, which are a typical consequence of the microfabrication process. A single-mode reduced-order model is derived and extensive numerical simulations are performed in a neighborhood of the first symmetric natural frequency, via frequency response diagrams and behavior chart. The typical softening behavior is observed and the overall scenario is explored, when both the frequency and the electrodynamic voltage are varied. We show that simulations based on direct numerical integration of the equation of motion in time yield satisfactory agreement with the experimental data. Nevertheless, these theoretical predictions are not completely fulfilled in some aspects. In particular, the range of existence of each attractor is smaller in practice than in the simulations. This is because these theoretical curves represent the ideal limit case where disturbances are absent, which never occurs under realistic conditions. A reliable prediction of the actual (and not only theoretical) range of existence of each attractor is essential in applications. To overcome this discrepancy and extend the results to the practical case where disturbances exist, a dynamical integrity analysis is developed. After introducing dynamical integrity concepts, integrity profiles and integrity charts are drawn. They are able to describe if each attractor is robust enough to tolerate the disturbances. Moreover, they detect the parameter range where each branch can be reliably observed in practice and where, instead, becomes vulnerable, i.e. they provide valuable information to operate the device in safe conditions according to the desired outcome and depending on the expected disturbances

  19. Nonlinear dynamics of an electrically actuated imperfect microbeam resonator: Experimental investigation and reduced-order modeling

    KAUST Repository

    Ruzziconi, Laura

    2013-06-10

    We present a study of the dynamic behavior of a microelectromechanical systems (MEMS) device consisting of an imperfect clamped-clamped microbeam subjected to electrostatic and electrodynamic actuation. Our objective is to develop a theoretical analysis, which is able to describe and predict all the main relevant aspects of the experimental response. Extensive experimental investigation is conducted, where the main imperfections coming from microfabrication are detected, the first four experimental natural frequencies are identified and the nonlinear dynamics are explored at increasing values of electrodynamic excitation, in a neighborhood of the first symmetric resonance. Several backward and forward frequency sweeps are acquired. The nonlinear behavior is highlighted, which includes ranges of multistability, where the nonresonant and the resonant branch coexist, and intervals where superharmonic resonances are clearly visible. Numerical simulations are performed. Initially, two single mode reduced-order models are considered. One is generated via the Galerkin technique, and the other one via the combined use of the Ritz method and the Padé approximation. Both of them are able to provide a satisfactory agreement with the experimental data. This occurs not only at low values of electrodynamic excitation, but also at higher ones. Their computational efficiency is discussed in detail, since this is an essential aspect for systematic local and global simulations. Finally, the theoretical analysis is further improved and a two-degree-of-freedom reduced-order model is developed, which is also capable of capturing the measured second symmetric superharmonic resonance. Despite the apparent simplicity, it is shown that all the proposed reduced-order models are able to describe the experimental complex nonlinear dynamics of the device accurately and properly, which validates the proposed theoretical approach. © 2013 IOP Publishing Ltd.

  20. Theory, development, and applications of the scanning positron microbeam and positron reemission microscope

    International Nuclear Information System (INIS)

    Brandes, G.R.

    1990-01-01

    The theory, design, development, and applications of two new imaging instruments, the scanning positron microbeam (SPM) and positron reemission microscope (PRM), are discussed. The SPM consists of a sectored lens which focuses and rasters the positrons from the beam across the sample. The results of rastering the 10μm x 50μm beam across a test grid demonstrate the SPM's ability to scan a 500μm diameter region and to resolve features with ∼ 5μm resolution. The SPM was used to examine the location of defects in a Si-on-SiO 2 sample. Possible applications to three dimensional defect spectroscopy and the observation of small samples are considered. In the PRM, the positrons from the brightness-enhanced beam are focused at 5keV to an 8/Am diameter spot (FWHM) onto a thin metal single crystal. An image of the opposing side of the film is formed by accelerating and focusing the reemitted thermalized positrons with a cathode lens objective and a projector lens. The final image (real) is a record of the thermal positron emission intensity versus position. Images of surface and subsurface defect structures, taken at magnifications up to 4400x and with a resolution up to 80nm, are presented and discussed. The ultimate resolution capabilities and possible applications of the PRM are examined. The implantation and diffusion process of positrons was studied with the PRM by examining the positron emission profile of 3-9keV positrons implanted into a 2200 angstrom thick Ni single crystal

  1. Micro-beam X-ray fluorescence and absorption imaging techniques at the IAEA Laboratories

    International Nuclear Information System (INIS)

    Wegrzynek, Dariusz; Markowicz, A.; Bamford, S.; Chinea-Cano, E.; Bogovac, M.

    2005-01-01

    X-ray tube based, micro-beam X-ray fluorescence scanning spectrometer has been equipped with two energy dispersive X-ray detectors. The two-detector configuration allows for simultaneous collection of X-ray fluorescence (XRF) and transmitted X-ray beam signals with a spatial resolution in the range of 10-50 μm, depending on the X-ray focussing element in use. The XRF signal is collected with a standard, liquid nitrogen cooled Si(Li) detector. The X-ray beam transmitted through the sample is acquired with a thermoelectrically cooled, silicon drift (SD) detector. The data acquisition is carried out in a fully automatic way under control of the SPECTOR-LOCATOR software. The software controls the scanning procedure and X-ray spectra acquisition during the scan. The energy dispersive X-ray spectra collected at every 'pixel' are stored for off-line processing. For selected regions of interest (ROI's), the element maps are constructed and displayed on-line. The spectrometer has been used for mapping elemental distributions and for performing 2D- and 3D-tomograpic imaging of minute objects in X-ray absorption and in X-ray fluorescence mode. A unique feature of the described system is simultaneous utilization of the two detectors, Si(Li) and SD, which adds new options for quantitative analysis and data interpretation. Examples of elemental mapping and 3D tomographic imaging as well as the advanced features of the SPECTOR-LOCATOR measurement control and data acquisition software are presented in this work

  2. Reconstruction of human exposure to heavy metals using synchrotron radiation microbeams in prehistoric and modern humans

    International Nuclear Information System (INIS)

    Koizumi, Akio; Azechi, Miki; Shirasawa, Koyo

    2009-01-01

    Teeth can serve as records of environmental exposure to heavy metals during their formation. We applied a new technology - synchrotron radiation microbeams (SRXRF) - for analysis of heavy metals in human permanent teeth in modern and historical samples. Each tooth was cut in half. A longitudinal section 200 μm in thickness was subjected to the determination of the heavy metal content by SRXRF or conventional analytical methods (ICP-MS analysis or reduction-aeration atomic absorption spectrometry). The relative concentrations of Pb, Hg, Cu and Zn measured by SRXRF were translated in concentrations (in g of heavy metal/g of enamel) using calibration curves by the two analytical methods. Concentrations in teeth in the modern females (n=5) were 1.2±0.5 μg/g (n=5) for Pb; 1.7±0.2 ng/g for Hg; 0.9±1.1 μg/g for Cu; 150±24.6 μg/g for Zn. The levels of Pb were highest in the teeth samples obtained from the humans of the Edo era (1603-1868 AD) (0.5-4.0 μg/g, n=4). No trend was observed in this study in the Hg content in teeth during 3,000 years. The concentrations of Cu were highest in teeth of two medieval craftsmen (57.0 and 220 μg/g). The levels of Zn were higher in modern subjects (P<0.05) than those in the Jomon (∼1000 BC) to Edo periods [113.2±27.4 (μg/g, n=11)]. Reconstruction of developmental exposure history to lead in a famous court painter of the Edo period (18th century) revealed high levels of Pb (7.1-22.0 μg/g) in his childhood. SRXRF is useful a method for reconstructing human exposures in very long trends. (author)

  3. Radiation hardness of n-type SiC Schottky barrier diodes irradiated with MeV He ion microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Pastuović, Željko, E-mail: zkp@ansto.gov.au [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Capan, Ivana [Material Physics Division, Institute Rudjer Boskovic, PO Box 180, 10000 Zagreb (Croatia); Cohen, David D. [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Forneris, Jacopo [Physics Department and NIS Excellence Centre, University of Torino, via P. Giuria 1, 10125 Torino (Italy); Iwamoto, Naoya; Ohshima, Takeshi [Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Siegele, Rainer [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Hoshino, Norihiro; Tsuchida, Hidekazu [Central Research Institute of Electric Power Industry, 2-6-1 Nagasaka, Yokosuka, Kanagawa 240-0196 (Japan)

    2015-04-01

    We studied the radiation hardness of 4H-SiC Schottky barrier diodes (SBD) for the light ion detection and spectroscopy in harsh radiation environments. n-Type SBD prepared on nitrogen-doped (∼4 × 10{sup 14} cm{sup −3}) epitaxial grown 4H-SiC thin wafers have been irradiated by a raster scanning alpha particle microbeam (2 and 4 MeV He{sup 2+} ions separately) in order to create patterned damage structures at different depths within a sensitive volume of tested diodes. Deep Level Transient Spectroscopy (DLTS) analysis revealed the formation of two deep electron traps in the irradiated and not thermally treated 4H-SiC within the ion implantation range (E1 and E2). The E2 state resembles the well-known Z{sub 1/2} center, while the E1 state could not be assigned to any particular defect reported in the literature. Ion Beam Induced Charge (IBIC) microscopy with multiple He ion probe microbeams (1–6 MeV) having different penetration depths in tested partly damaged 4H-SiC SBD has been used to determine the degradation of the charge collection efficiency (CCE) over a wide fluence range of damaging alpha particle. A non-linear behavior of the CCE decrease and a significant degradation of the spectroscopic performance with increasing He ion fluence were observed above the value of 10{sup 11} cm{sup −2}.

  4. Role of the micronucleus in stomatogenesis in sexual reproduction of Paramecium tetraurelia: laser microbeam irradiation of the micronucleus

    Energy Technology Data Exchange (ETDEWEB)

    Tam Laiwa; Ng, S.F.

    1986-12-01

    Fifteen amicronucleate cell lines and 22 cell lines with defective micronuclei were obtained following selective laser microbeam irradiation of the micronucleus. The amicronucleate cell lines showed reduced growth rate and formed abnormal oral apparatuses in asexual reproduction, and failed to produce any oral apparatus in autogamy. The 22 cell lines with defective micronucleus exhibited various abnormalities of the oral apparatus newly formed during autogamy. These abnormalities included the arrest of membranelle assembly, reduction in the length of the buccal cavity and oral membranelles, disruption of the organization of the membranelles, quadrulation of the dorsal peniculus, and failure of addition of membranellar basal body rows. Hence the micronucleus plays multiple roles in sexual stomatogenesis. Our results agree with the notion that the micronucleus acts during a critical period between the second meiotic division and up to the formation of the zygotic nucleus to control the early stage of oral membranelle assembly. Laser microbeam irradiation might have created recessive mutations and/or chromosomal aberrations, which were expressed during this critical period with the formation of abnormal postmeiotic nuclei.

  5. The role of the micronucleus in stomatogenesis in sexual reproduction of Paramecium tetraurelia: laser microbeam irradiation of the micronucleus

    International Nuclear Information System (INIS)

    Tam Laiwa; Ng, S.F.

    1986-01-01

    Fifteen amicronucleate cell lines and 22 cell lines with defective micronuclei were obtained following selective laser microbeam irradiation of the micronucleus. The amicronucleate cell lines showed reduced growth rate and formed abnormal oral apparatuses in asexual reproduction, and failed to produce any oral apparatus in autogamy. The 22 cell lines with defective micronucleus exhibited various abnormalities of the oral apparatus newly formed during autogamy. These abnormalities included the arrest of membranelle assembly, reduction in the length of the buccal cavity and oral membranelles, disruption of the organization of the membranelles, quadrulation of the dorsal peniculus, and failure of addition of membranellar basal body rows. Hence the micronucleus plays multiple roles in sexual stomatogenesis. Our results agree with the notion that the micronucleus acts during a critical period between the second meiotic division and up to the formation of the zygotic nucleus to control the early stage of oral membranelle assembly. Laser microbeam irradiation might have created recessive mutations and/or chromosomal aberrations, which were expressed during this critical period with the formation of abnormal postmeiotic nuclei. (author)

  6. Microbeam facility extension for single-cell irradiation experiments. Investigations about bystander effect and reactive oxygen species impact

    International Nuclear Information System (INIS)

    Hanot, M.; Khodja, H.; Daudin, L.; Hoarau, J.; Carriere, M.; Gouget, B.

    2006-01-01

    The LPS microbeam facility is based on a KN3750 Van de Graaff accelerator devoted to microbeam analysis [1]. It is equipped with two horizontal microbeam lines used in various fields such as material science, geological science, nuclear material science and biology. Since two years, a single ion hit device is being developed at the LPS. The setup is dedicated to the study of ionizing radiation effects on living cells by performing single ion irradiation at controlled doses and locations. This study will complete current researches conducted on uranium chemical toxicity on renal an d osteoblastic cells. After ingestion, most uranium is excreted from the body within a few days except small fraction that is absorbed into the blood-stream (0.2 to 5%) and then deposit and preferentially in kidneys and bones, where it can remain for many years. Uranium is a heavy metal and a primarily alpha emitter. It can lead to bone cancer as a result of the ionizing radiation associated with the radioactive decay products. The study of the response to an exposure to alpha particles will permit to distinguish radiotoxicity and chemical toxicity of uranium bone cells with a special emphasis or the bystander effect at low dose.All the beam lines at the LPS nuclear microprobe are horizontal and under vacuum. A dedicated deflecting magnet was inserted in one of the two available beam lines of the facility. The ion beam is extracted to air using a 100 nm thick silicon nitride membrane, thin enough to induce negligible effects on the ions in terms of energy loss and spatial resolution. By this way, we believe that we minimize the experimental setup impact on the living cells easing the detection of low irradiation dose impact. The atmosphere around the samples is also important to guaranty low stressed cell culture conditions. A temperature, hygrometry and CO 2 controlled atmosphere device will be implanted in the future. The irradiation microbeam is produced using a fused silica capillary

  7. Coupling in reflector arrays

    DEFF Research Database (Denmark)

    Appel-Hansen, Jørgen

    1968-01-01

    In order to reduce the space occupied by a reflector array, it is desirable to arrange the array antennas as close to each other as possible; however, in this case coupling between the array antennas will reduce the reflecting properties of the reflector array. The purpose of the present communic......In order to reduce the space occupied by a reflector array, it is desirable to arrange the array antennas as close to each other as possible; however, in this case coupling between the array antennas will reduce the reflecting properties of the reflector array. The purpose of the present...

  8. Investigation on the biological effects of pharynx irradiation by single-particle microbeam and C.elegans immobilization

    International Nuclear Information System (INIS)

    Guo Xiaoying; Yang Gen; Chen Lianyun; Wu Lijun; Li Buqing

    2010-01-01

    Using C.elegans- with clear genetic background, easy genetic maneuverability, small individual, transparence, easily penetrated by a variety of particle as a in vivo model organism, irradiation damage at the individual level of the signal transduction and the mechanism research were investigated. In order to radiate accurately, the worms need Immobilize. The results showed that the ether: ethanol = 1:1 mixture, enabled the worms quickly anesthesia, and kept the worms Immobilization in the whole irradiation process, then quickly recovered after irradiation and recovery rate of 100%. On the basis, the laved and the apoptotic cells in the distal gonad would be test when the worm pharynx were irradiated by single-particle microbeam. The primary results showed that the apoptotic cells in distal gonad significantly increased when the worm pharynx were irradiated 5000 particles. (authors)

  9. Investigation of the Dynamics of a Clamped-Clamped Microbeam Near the Third Mode Using a Partial Electrode

    KAUST Repository

    Masri, Karim M.

    2014-08-17

    We present an investigation of the dynamics of a clamped-clamped microbeam excited electrostatically near its third mode. To maximize the response at the third mode, a partial electrode configuration is utilized. A multi-mode Galerkin method is used to develop a reduced order model (ROM) of the beam. A shooting method to find the periodic motion is utilized to generate frequency response curves. The curves show hardenining behavior and dynamic pull-in. We show that the dynamic amplitude of the partial configuration is higher than that of a full electrode configuration. These results are promising for the use of higher-order modes for mass detection and for ultra sensitive resonant sensors.

  10. Damaging and protective bystander cross-talk between human lung cancer and normal cells after proton microbeam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Desai, Sejal [Radiation Signalling and Cancer Biology Section, Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kobayashi, Alisa; Konishi, Teruaki; Oikawa, Masakazu [Radiation System and Engineering Section, Department of Technical Support and Development, Research, Development and Support Center, National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Pandey, Badri N., E-mail: badrinarain@yahoo.co.in [Radiation Signalling and Cancer Biology Section, Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2014-05-15

    Graphical abstract: - Highlights: • Proton-microbeam irradiated A549 cells send damaging signals to bystander A549 cells. • Irradiated A549–A549 bystander response is through gap junctional communication. • Bystander WI38 cells exert protective signalling in irradiated A549 cells. • Rescue of irradiated A549 cells by WI38 cells is independent of gap junctions. - Abstract: Most of the studies of radiation-induced bystander effects (RIBE) have been focused on understanding the radiobiological changes observed in bystander cells in response to the signals from irradiated cells in a normal cell population with implications to radiation risk assessment. However, reports on RIBE with relevance to cancer radiotherapy especially investigating the bidirectional and criss-cross bystander communications between cancer and normal cells are limited. Hence, in present study employing co-culture approach, we have investigated the bystander cross-talk between lung cancer (A549) and normal (WI38) cells after proton-microbeam irradiation using γ-H2AX foci fluorescence as a measure of DNA double-strand breaks (DSBs). We observed that in A549–A549 co-cultures, irradiated A549 cells exert damaging effects in bystander A549 cells, which were found to be mediated through gap junctional intercellular communication (GJIC). However, in A549–WI38 co-cultures, irradiated A549 did not affect bystander WI38 cells. Rather, bystander WI38 cells induced inverse protective signalling (rescue effect) in irradiated A549 cells, which was independent of GJIC. On the other hand, in response to irradiated WI38 cells neither of the bystander cells (A549 or WI38) showed significant increase in γ-H2AX foci. The observed bystander signalling between tumour and normal cells may have potential implications in therapeutic outcome of cancer radiotherapy.

  11. Damaging and protective bystander cross-talk between human lung cancer and normal cells after proton microbeam irradiation

    International Nuclear Information System (INIS)

    Desai, Sejal; Kobayashi, Alisa; Konishi, Teruaki; Oikawa, Masakazu; Pandey, Badri N.

    2014-01-01

    Graphical abstract: - Highlights: • Proton-microbeam irradiated A549 cells send damaging signals to bystander A549 cells. • Irradiated A549–A549 bystander response is through gap junctional communication. • Bystander WI38 cells exert protective signalling in irradiated A549 cells. • Rescue of irradiated A549 cells by WI38 cells is independent of gap junctions. - Abstract: Most of the studies of radiation-induced bystander effects (RIBE) have been focused on understanding the radiobiological changes observed in bystander cells in response to the signals from irradiated cells in a normal cell population with implications to radiation risk assessment. However, reports on RIBE with relevance to cancer radiotherapy especially investigating the bidirectional and criss-cross bystander communications between cancer and normal cells are limited. Hence, in present study employing co-culture approach, we have investigated the bystander cross-talk between lung cancer (A549) and normal (WI38) cells after proton-microbeam irradiation using γ-H2AX foci fluorescence as a measure of DNA double-strand breaks (DSBs). We observed that in A549–A549 co-cultures, irradiated A549 cells exert damaging effects in bystander A549 cells, which were found to be mediated through gap junctional intercellular communication (GJIC). However, in A549–WI38 co-cultures, irradiated A549 did not affect bystander WI38 cells. Rather, bystander WI38 cells induced inverse protective signalling (rescue effect) in irradiated A549 cells, which was independent of GJIC. On the other hand, in response to irradiated WI38 cells neither of the bystander cells (A549 or WI38) showed significant increase in γ-H2AX foci. The observed bystander signalling between tumour and normal cells may have potential implications in therapeutic outcome of cancer radiotherapy

  12. Sub-millisecond time-resolved SAXS using a continuous-flow mixer and X-ray microbeam.

    Science.gov (United States)

    Graceffa, Rita; Nobrega, R Paul; Barrea, Raul A; Kathuria, Sagar V; Chakravarthy, Srinivas; Bilsel, Osman; Irving, Thomas C

    2013-11-01

    Small-angle X-ray scattering (SAXS) is a well established technique to probe the nanoscale structure and interactions in soft matter. It allows one to study the structure of native particles in near physiological environments and to analyze structural changes in response to variations in external conditions. The combination of microfluidics and SAXS provides a powerful tool to investigate dynamic processes on a molecular level with sub-millisecond time resolution. Reaction kinetics in the sub-millisecond time range has been achieved using continuous-flow mixers manufactured using micromachining techniques. The time resolution of these devices has previously been limited, in part, by the X-ray beam sizes delivered by typical SAXS beamlines. These limitations can be overcome using optics to focus X-rays to the micrometer size range providing that beam divergence and photon flux suitable for performing SAXS experiments can be maintained. Such micro-SAXS in combination with microfluidic devices would be an attractive probe for time-resolved studies. Here, the development of a high-duty-cycle scanning microsecond-time-resolution SAXS capability, built around the Kirkpatrick-Baez mirror-based microbeam system at the Biophysics Collaborative Access Team (BioCAT) beamline 18ID at the Advanced Photon Source, Argonne National Laboratory, is reported. A detailed description of the microbeam small-angle-scattering instrument, the turbulent flow mixer, as well as the data acquisition and control and analysis software is provided. Results are presented where this apparatus was used to study the folding of cytochrome c. Future prospects for this technique are discussed.

  13. Sub-millisecond time-resolved SAXS using a continuous-flow mixer and X-ray microbeam

    International Nuclear Information System (INIS)

    Graceffa, Rita; Nobrega, R. Paul; Barrea, Raul A.; Kathuria, Sagar V.; Chakravarthy, Srinivas; Bilsel, Osman; Irving, Thomas C.

    2013-01-01

    The development of a high-duty-cycle microsecond time-resolution SAXS capability at the Biophysics Collaborative Access Team beamline (BioCAT) 18ID at the Advanced Photon Source, Argonne National Laboratory, USA, is reported. Small-angle X-ray scattering (SAXS) is a well established technique to probe the nanoscale structure and interactions in soft matter. It allows one to study the structure of native particles in near physiological environments and to analyze structural changes in response to variations in external conditions. The combination of microfluidics and SAXS provides a powerful tool to investigate dynamic processes on a molecular level with sub-millisecond time resolution. Reaction kinetics in the sub-millisecond time range has been achieved using continuous-flow mixers manufactured using micromachining techniques. The time resolution of these devices has previously been limited, in part, by the X-ray beam sizes delivered by typical SAXS beamlines. These limitations can be overcome using optics to focus X-rays to the micrometer size range providing that beam divergence and photon flux suitable for performing SAXS experiments can be maintained. Such micro-SAXS in combination with microfluidic devices would be an attractive probe for time-resolved studies. Here, the development of a high-duty-cycle scanning microsecond-time-resolution SAXS capability, built around the Kirkpatrick–Baez mirror-based microbeam system at the Biophysics Collaborative Access Team (BioCAT) beamline 18ID at the Advanced Photon Source, Argonne National Laboratory, is reported. A detailed description of the microbeam small-angle-scattering instrument, the turbulent flow mixer, as well as the data acquisition and control and analysis software is provided. Results are presented where this apparatus was used to study the folding of cytochrome c. Future prospects for this technique are discussed

  14. Sub-millisecond time-resolved SAXS using a continuous-flow mixer and X-ray microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Graceffa, Rita, E-mail: rita.graceffa@gmail.com [Illinois Institute of Technology, 3101 South Dearborn, Chicago, IL 60616 (United States); Nobrega, R. Paul [University of Massachusetts Medical School, 364 Plantation Street, LRB 919, Worcester, MA 01605 (United States); Barrea, Raul A. [Illinois Institute of Technology, 3101 South Dearborn, Chicago, IL 60616 (United States); Kathuria, Sagar V. [University of Massachusetts Medical School, 364 Plantation Street, LRB 919, Worcester, MA 01605 (United States); Chakravarthy, Srinivas [Illinois Institute of Technology, 3101 South Dearborn, Chicago, IL 60616 (United States); Bilsel, Osman [University of Massachusetts Medical School, 364 Plantation Street, LRB 919, Worcester, MA 01605 (United States); Irving, Thomas C. [Illinois Institute of Technology, 3101 South Dearborn, Chicago, IL 60616 (United States)

    2013-11-01

    The development of a high-duty-cycle microsecond time-resolution SAXS capability at the Biophysics Collaborative Access Team beamline (BioCAT) 18ID at the Advanced Photon Source, Argonne National Laboratory, USA, is reported. Small-angle X-ray scattering (SAXS) is a well established technique to probe the nanoscale structure and interactions in soft matter. It allows one to study the structure of native particles in near physiological environments and to analyze structural changes in response to variations in external conditions. The combination of microfluidics and SAXS provides a powerful tool to investigate dynamic processes on a molecular level with sub-millisecond time resolution. Reaction kinetics in the sub-millisecond time range has been achieved using continuous-flow mixers manufactured using micromachining techniques. The time resolution of these devices has previously been limited, in part, by the X-ray beam sizes delivered by typical SAXS beamlines. These limitations can be overcome using optics to focus X-rays to the micrometer size range providing that beam divergence and photon flux suitable for performing SAXS experiments can be maintained. Such micro-SAXS in combination with microfluidic devices would be an attractive probe for time-resolved studies. Here, the development of a high-duty-cycle scanning microsecond-time-resolution SAXS capability, built around the Kirkpatrick–Baez mirror-based microbeam system at the Biophysics Collaborative Access Team (BioCAT) beamline 18ID at the Advanced Photon Source, Argonne National Laboratory, is reported. A detailed description of the microbeam small-angle-scattering instrument, the turbulent flow mixer, as well as the data acquisition and control and analysis software is provided. Results are presented where this apparatus was used to study the folding of cytochrome c. Future prospects for this technique are discussed.

  15. Investigation of double strand breaks induced by alpha particle irradiation using C.N.B.G. microbeam in human keratinocytes

    International Nuclear Information System (INIS)

    Pouthier, Th.

    2006-12-01

    To understand the mechanisms of interaction of ionizing radiation with living tissues exposed to low and protracted doses remains a major issue for risk evaluation. The response cannot be found in epidemiological studies because the only available data concern accidental exposures to high doses of radiation. The natural exposure represents the main source of exposure in the daily life, just before the medical sources (radiology, radiotherapy). In addition, this kind of exposure is very difficult to reproduce in vitro by irradiating cell lines. The method per preference is based on random irradiation of cell populations. The mean number of particles having traversed cells is then calculated on the basis of Poisson statistics. In addition to inevitable multiple impacts, the numerous potential intracellular targets (nuclei, cytoplasm), the indirect effects induced by the impact of particles on neighbouring cells or simply the extracellular targets, constitute phenomena that make more complex the interpretation of experimental data. A charged particle microbeam was developed at C.E.N.B.G. to perform the targeted irradiation of individual cells with a targeting precision of a few microns. It is possible to deliver a counted number of alpha particles down to the ultimate dose of one alpha per cell, to target predetermined cells and then to observe the response of the neighbouring cells. This facility has been validated during this work on human keratinocyte cells expressing a recombinant nuclear fluorescent protein (histone H2B-GFP). The combination of ion micro-beams with confocal microscopy and numeric quantitative analysis allowed the measurement of DNA double strand breaks via the phosphorylation of the histone H2A.X in individual cells. The mechanisms of DNA reparation and apoptosis induction were also in the scope of those studies. The experimental results obtained during this thesis validate the methodology we have developed by demonstrating the targeting

  16. DNA damage on nano- and micrometer scales impacts dicentric induction: computer modelling of ion microbeam experiments

    Science.gov (United States)

    Friedland, Werner; Kundrat, Pavel; Schmitt, Elke

    2016-07-01

    Detailed understanding of the enhanced relative biological effectiveness (RBE) of ions, in particular at high linear energy transfer (LET) values, is needed to fully explore the radiation risk of manned space missions. It is generally accepted that the enhanced RBE of high-LET particles results from the DNA lesion patterns, in particular DNA double-strand breaks (DSB), due to the spatial clustering of energy deposits around their trajectories. In conventional experiments on biological effects of radiation types of diverse quality, however, clustering of energy deposition events on nanometer scale that is relevant for the induction and local complexity of DSB is inherently interlinked with regional (sub-)micrometer-scale DSB clustering along the particle tracks. Due to this limitation, the role of both (nano- and micrometer) scales on the induction of diverse biological endpoints cannot be frankly separated. To address this issue in a unique way, experiments at the ion microbeam SNAKE [1] and corresponding track-structure based model calculations of DSB induction and subsequent repair with the biophysical code PARTRAC [2] have been performed. In the experiments, hybrid human-hamster A_{L} cells were irradiated with 20 MeV (2.6 keV/μm) protons, 45 MeV (60 keV/μm) lithium ions or 55 MeV (310 keV/μm) carbon ions. The ions were either quasi-homogeneously distributed or focused to 0.5 x 1 μm^{2} spots on regular matrix patterns of 5.4 μm, 7.6 μm and 10.6 μm grid size, with pre-defined particle numbers per spot so as to deposit a mean dose of 1.7 Gy for all irradiation patterns. As expected, the induction of dicentrics by homogeneous irradiation increased with LET: lithium and carbon ions induced about two- and four-fold higher yields of dicentrics than protons. The induction of dicentrics is, however, affected by µm-scale, too: focusing 20 lithium ions or 451 protons per spot on a 10.6 μm grid induced two or three times more dicentrics, respectively, than a

  17. Facile fabrication of chitosan-calcium carbonate nanowall arrays and their use as a sensitive non-enzymatic organophosphate pesticide sensor

    Science.gov (United States)

    Gong, Jingming; Zhang, Wei; Liu, Ting; Zhang, Lizhi

    2011-08-01

    Novel nanowall arrays of CaCO3-chitosan (CaCO3-chi) were deposited onto a cathodic substrate by a facile one-step electrodeposition approach. Results demonstrate that chitosan plays an important role in the formation of nanowall arrays. Freestanding well-aligned CaCO3-chi nanowall arrays were observed to be uniformly distributed over the whole substrate with a lateral dimension in the micrometre size and an average pore size of ~400 nm. The as-formed CaCO3-chi nanowall arrays featuring interlaced porous network architecture, large surface area, and open boundaries, are highly efficient in the capture of organophosphate pesticides (OPs). Combined with stripping voltammetry, a highly sensitive non-enzymatic OPs sensor was fabricated using the prepared CaCO3-chi nanowall arrays for solid phase extraction (SPE). The detection limit for methyl parathion (MP) in aqueous solutions was determined to be 0.8 ng mL-1 (S/N = 3). The resulting sensor made of novel CaCO3-chi nanowall arrays exhibits good reproducibility and acceptable stability. This work not only provides a facile and effective route for the preparation of CaCO3-chi nanowall arrays, but also offers a new promising protocol for OPs analysis.

  18. Methods for assisting recovery of damaged brain and spinal cord and treating various diseases using arrays of x-ray microplanar beams

    Energy Technology Data Exchange (ETDEWEB)

    Dilmanian, F Avraham [Yaphank, NY; Anchel, David J [Rocky Point, NY; Gaudette, Glenn [Holden, MA; Romanelli, Pantaleo [Monteroduni, IT; Hainfeld, James [Shoreham, NY

    2010-06-29

    A method of assisting recovery of an injury site of the central nervous system (CNS) or treating a disease includes providing a therapeutic dose of X-ray radiation to a target volume through an array of parallel microplanar beams. The dose to treat CNS injury temporarily removes regeneration inhibitors from the irradiated site. Substantially unirradiated cells surviving between beams migrate to the in-beam portion and assist recovery. The dose may be staggered in fractions over sessions using angle-variable intersecting microbeam arrays (AVIMA). Additional doses are administered by varying the orientation of the beams. The method is enhanced by injecting stem cells into the injury site. One array or the AVIMA method is applied to ablate selected cells in a target volume associated with disease for palliative or curative effect. Atrial fibrillation is treated by irradiating the atrial wall to destroy myocardial cells while continuously rotating the subject.

  19. Studies of Bystander Effects in 3-D Tissue Systems Using a Low-LET Microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Brenner, David J.

    2009-07-17

    frequency was also observed. When cells were cultured in medium donated from cells exposed to 5 Gy X-rays, a significant bystander effect was observed for clonogenic survival. When cells were cultured for 5 h with supernatant from donor cells exposed to 2 cGy and were then irradiated with 4 Gy X-rays, they failed to show an increase in survival compared with cells directly irradiated with 4 Gy. However, a twofold reduction in the oncogenic transformation frequency was seen. An adaptive dose of X-rays cancelled out the majority of the bystander effect produced by alpha-particles. For oncogenic transformation, but not cell survival, radioadaption can occur in unirradiated cells via a transmissible factor(s). A pilot study was undertaken to observe the bystander effect in a realistic multicellular three-dimensional morphology. We found bystander responses in a three-dimensional, normal human-tissue system. Endpoints were induction of micronucleated and apoptotic cells. A charged-particle microbeam was used, allowing irradiation of cells in defined locations in the tissue yet guaranteeing that no cells located more than a few micrometers away receive any radiation exposure. Unirradiated cells up to 1 mm distant from irradiated cells showed a significant enhancement in effect over background, with an average increase in effect of 1.7-fold for micronuclei and 2.8-fold for apoptosis. The surprisingly long range of bystander signals in human tissue suggests that bystander responses may be important in extrapolating radiation risk estimates from epidemiologically accessible doses down to very low doses where nonhit bystander cells will predominate. Finally, it would be of great benefit to develop a reproducible tissue system suitable for critical radiobiological assays. We have developed a reliable protocol to harvest cells from tissue samples and to investigate the damage induced on a single cell basis. In order to result in a valid tool for bystander experiments, the method

  20. Studies of Bystander Effects in 3-D Tissue Systems Using a Low-LET Microbeam

    International Nuclear Information System (INIS)

    Brenner, David J.

    2009-01-01

    frequency was also observed. When cells were cultured in medium donated from cells exposed to 5 Gy X-rays, a significant bystander effect was observed for clonogenic survival. When cells were cultured for 5 h with supernatant from donor cells exposed to 2 cGy and were then irradiated with 4 Gy X-rays, they failed to show an increase in survival compared with cells directly irradiated with 4 Gy. However, a twofold reduction in the oncogenic transformation frequency was seen. An adaptive dose of X-rays cancelled out the majority of the bystander effect produced by alpha-particles. For oncogenic transformation, but not cell survival, radioadaption can occur in unirradiated cells via a transmissible factor(s). A pilot study was undertaken to observe the bystander effect in a realistic multicellular three-dimensional morphology. We found bystander responses in a three-dimensional, normal human-tissue system. Endpoints were induction of micronucleated and apoptotic cells. A charged-particle microbeam was used, allowing irradiation of cells in defined locations in the tissue yet guaranteeing that no cells located more than a few micrometers away receive any radiation exposure. Unirradiated cells up to 1 mm distant from irradiated cells showed a significant enhancement in effect over background, with an average increase in effect of 1.7-fold for micronuclei and 2.8-fold for apoptosis. The surprisingly long range of bystander signals in human tissue suggests that bystander responses may be important in extrapolating radiation risk estimates from epidemiologically accessible doses down to very low doses where nonhit bystander cells will predominate. Finally, it would be of great benefit to develop a reproducible tissue system suitable for critical radiobiological assays. We have developed a reliable protocol to harvest cells from tissue samples and to investigate the damage induced on a single cell basis. In order to result in a valid tool for bystander experiments, the method

  1. Fiber Laser Array

    National Research Council Canada - National Science Library

    Simpson, Thomas

    2002-01-01

    ...., field-dependent, loss within the coupled laser array. During this program, Jaycor focused on the construction and use of an experimental apparatus that can be used to investigate the coherent combination of an array of fiber lasers...

  2. Establishing the suitability of quantitative optical CT microscopy of PRESAGE® radiochromic dosimeters for the verification of synchrotron microbeam therapy.

    Science.gov (United States)

    Doran, Simon J; Abdul Rahman, A T; Bräuer-Krisch, Elke; Brochard, Thierry; Adamovics, John; Nisbet, Andrew; Bradley, David

    2013-09-21

    Previous research on optical computed tomography (CT) microscopy in the context of the synchrotron microbeam has shown the potential of the technique and demonstrated high quality images, but has left two questions unanswered: (i) are the images suitably quantitative for 3D dosimetry? and (ii) what is the impact on the spatial resolution of the system of the limited depth-of-field of the microscope optics? Cuvette and imaging studies are reported here that address these issues. Two sets of cuvettes containing the radiochromic plastic PRESAGE® were irradiated at the ID17 biomedical beamline of the European Synchrotron Radiation facility over the ranges 0-20 and 0-35 Gy and a third set of cuvettes was irradiated over the range 0-20 Gy using a standard medical linac. In parallel, three cylindrical PRESAGE® samples of diameter 9.7 mm were irradiated with test patterns that allowed the quantitative capabilities of the optical CT microscope to be verified, and independent measurements of the imaging modulation transfer function (MTF) to be made via two different methods. Both spectrophotometric analysis and imaging gave a linear dose response, with gradients ranging from 0.036-0.041 cm(-1) Gy(-1) in the three sets of cuvettes and 0.037 (optical CT units) Gy(-1) for the imaging. High-quality, quantitative imaging results were obtained throughout the 3D volume, as illustrated by depth-dose profiles. These profiles are shown to be monoexponential, and the linear attention coefficient of PRESAGE® for the synchrotron-generated x-ray beam is measured to be (0.185 ± 0.02) cm(-1) in excellent agreement with expectations. Low-level (microscopy images from our scanner do indeed have intensities that are proportional to spectrophotometric optical density and can thus be used as the basis for accurate dosimetry. However, further investigations are necessary before the microscopy images can be used to make the quantitative measures of peak-to-valley ratios for small

  3. Axiom turkey genotyping array

    Science.gov (United States)

    The Axiom®Turkey Genotyping Array interrogates 643,845 probesets on the array, covering 643,845 SNPs. The array development was led by Dr. Julie Long of the USDA-ARS Beltsville Agricultural Research Center under a public-private partnership with Hendrix Genetics, Aviagen, and Affymetrix. The Turk...

  4. Photons bring light into DNA repair: the comet assay and laser microbeams for studying photogenotoxicity of drugs and ageing.

    Science.gov (United States)

    Greulich, Karl Otto

    2011-03-01

    This contribution reviews recent applications of micromanipulation, by UV photons, in DNA repair and ageing research as well as in the evaluation of the phototoxicity of drugs. In some cases, micromanipulation is combined with the comet assay, a technique, which allows a direct view on DNA damages. It is shown that, in humans, the sensitivity of DNA to UV induced damage and its subsequent repair is surprisingly stable up to high age and that drugs which are usually non-toxic induce DNA damage when irradiated in parallel by UV irradiation. Using the immune fluorescent comet assay, IFCA, a variant of the comet assay, direct comparison of the effects of ionizing (137) Cs radiation with those of localized UV radiation is possible. When a laser microbeam is used to damage DNA in a cell nucleus with high temporal and spatial resolution, it can be observed directly how repair molecules accumulate (are recruited) at the site of damage. Comparison of the recruitment speed allows establishing an order of DNA repair events. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Microbeam radiation therapy. Physical and biological aspects of a new cancer therapy and development of a treatment planning system

    Energy Technology Data Exchange (ETDEWEB)

    Bartzsch, Stefan

    2014-11-05

    Microbeam Radiation Therapy (MRT) is a novel treatment strategy against cancer. Highly brilliant synchrotron radiation is collimated to parallel, a few micrometre wide, planar beams and used to irradiate malignant tissues with high doses. The applied peak doses are considerably higher than in conventional radiotherapy, but valley doses between the beams remain underneath the established tissue tolerance. Previous research has shown that these beam geometries spare normal tissue, while being effective in tumour ablation. In this work physical and biological aspects of the therapy were investigated. A therapy planning system was developed for the first clinical treatments at the European Synchrotron Radiation Facility in Grenoble (France) and a dosimetry method based on radiochromic films was created to validate planned doses with measurements on a micrometre scale. Finally, experiments were carried out on a cellular level in order to correlate the physically planned doses with the biological damage caused in the tissue. The differences between Monte Carlo dose and dosimetry are less than 10% in the valley and 5% in the peak regions. Developed alternative faster dose calculation methods deviate from the computational intensive MC simulations by less than 15% and are able to determine the dose within a few minutes. The experiments in cell biology revealed an significant influence of intercellular signalling on the survival of cells close to radiation boundaries. These observations may not only be important for MRT but also for conventional radiotherapy.

  6. Self and Mutual Radiation Impedances for Modeling of Multi-Frequency CMUT Arrays.

    Science.gov (United States)

    Maadi, Mohammad; Zemp, Roger J

    2016-09-01

    Multi-frequency capacitive micromachined ultrasonic transducers (CMUTs) consist of interlaced large and small membranes for multiband operation. In modeling these devices, accurate and computationally efficient methods are required for computing self- and mutual-acoustic-radiation impedances. However, most previous works considered mutual-acoustic impedance between radiators of identical size. A need was thus found to revisit the fundamental framework for mutual-acoustic impedance for its applicability to radiators, especially flexural disks, of differing size. The Bouwkamp integral method is used to achieve infinite series expressions for self- and mutual-acoustic radiation impedances. Polynomial-fitting-based approximate relations of the mutual-acoustic impedance are developed for arbitrary array geometries and are in good agreement with exact expressions. The derived mutual-acoustic impedance is incorporated into equivalent circuit models of multi-frequency CMUTs showing excellent agreement with finite element modeling. The results demonstrate that mutual-acoustic interactions significantly impact device performance. The framework presented here may prove valuable for future design of multi-frequency arrays for novel multiscale imaging, superharmonic contrast imaging, and image therapy applications.

  7. Carbon nanotube nanoelectrode arrays

    Science.gov (United States)

    Ren, Zhifeng; Lin, Yuehe; Yantasee, Wassana; Liu, Guodong; Lu, Fang; Tu, Yi

    2008-11-18

    The present invention relates to microelectode arrays (MEAs), and more particularly to carbon nanotube nanoelectrode arrays (CNT-NEAs) for chemical and biological sensing, and methods of use. A nanoelectrode array includes a carbon nanotube material comprising an array of substantially linear carbon nanotubes each having a proximal end and a distal end, the proximal end of the carbon nanotubes are attached to a catalyst substrate material so as to form the array with a pre-determined site density, wherein the carbon nanotubes are aligned with respect to one another within the array; an electrically insulating layer on the surface of the carbon nanotube material, whereby the distal end of the carbon nanotubes extend beyond the electrically insulating layer; a second adhesive electrically insulating layer on the surface of the electrically insulating layer, whereby the distal end of the carbon nanotubes extend beyond the second adhesive electrically insulating layer; and a metal wire attached to the catalyst substrate material.

  8. Phased-array radars

    Science.gov (United States)

    Brookner, E.

    1985-02-01

    The operating principles, technology, and applications of phased-array radars are reviewed and illustrated with diagrams and photographs. Consideration is given to the antenna elements, circuitry for time delays, phase shifters, pulse coding and compression, and hybrid radars combining phased arrays with lenses to alter the beam characteristics. The capabilities and typical hardware of phased arrays are shown using the US military systems COBRA DANE and PAVE PAWS as examples.

  9. Integrated avalanche photodiode arrays

    Science.gov (United States)

    Harmon, Eric S.

    2015-07-07

    The present disclosure includes devices for detecting photons, including avalanche photon detectors, arrays of such detectors, and circuits including such arrays. In some aspects, the detectors and arrays include a virtual beveled edge mesa structure surrounded by resistive material damaged by ion implantation and having side wall profiles that taper inwardly towards the top of the mesa structures, or towards the direction from which the ion implantation occurred. Other aspects are directed to masking and multiple implantation and/or annealing steps. Furthermore, methods for fabricating and using such devices, circuits and arrays are disclosed.

  10. Cover array string reconstruction

    OpenAIRE

    Crochemore, Maxime; S. Iliopoulos, Costas; P. Pissis, Solon; Tischler, German

    2010-01-01

    International audience; A proper factor u of a string y is a cover of y if every letter of y is within some occurrence of u in y. The concept generalises the notion of periods of a string. An integer array C is the minimal-cover (resp. maximal-cover) array of y if C[i] is the minimal (resp. maximal) length of covers of y[0.. i], or zero if no cover exists. In this paper, we present a constructive algorithm checking the validity of an array as a minimal-cover or maximal-cover array of some str...

  11. Storage array reflection considerations

    International Nuclear Information System (INIS)

    Haire, M.J.; Jordan, W.C.; Taylor, R.G.

    1997-01-01

    The assumptions used for reflection conditions of single containers are fairly well established and consistently applied throughout the industry in nuclear criticality safety evaluations. Containers are usually considered to be either fully water reflected (i.e., surrounded by 6 to 12 in. of water) for safety calculations or reflected by 1 in. of water for nominal (structural material and air) conditions. Tables and figures are usually available for performing comparative evaluations of containers under various loading conditions. Reflection considerations used for evaluating the safety of storage arrays of fissile material are not as well established. When evaluating arrays, it has become more common for analysts to use calculations to demonstrate the safety of the array configuration. In performing these calculations, the analyst has considerable freedom concerning the assumptions made for modeling the reflection of the array. Considerations are given for the physical layout of the array with little or no discussion (or demonstration) of what conditions are bounded by the assumed reflection conditions. For example, an array may be generically evaluated by placing it in a corner of a room in which the opposing walls are far away. Typically, it is believed that complete flooding of the room is incredible, so the array is evaluated for various levels of water mist interspersed among array containers. This paper discusses some assumptions that are made regarding storage array reflection

  12. The set-up for forward scattered particle detection at the external microbeam facility of the INFN-LABEC laboratory in Florence

    Energy Technology Data Exchange (ETDEWEB)

    Giuntini, L. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Massi, M. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Calusi, S. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Gelli, N.; Castelli, L. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Carraresi, L.; Czelusniak, C. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Fedi, M.E. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Gueli, A.M. [Dipartimento di Fisica e Astronomia, Università di Catania, Via Santa Sofia 64, 95123 Catania (Italy); INFN Sezione di Catania, Via Santa Sofia 64, 95123 Catania (Italy); Liccioli, L.; Mandò, P.A.; Mazzinghi, A. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Palla, L. [INFN, Sezione di Pisa and Università di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa (Italy); and others

    2015-04-01

    In the last few years some new implementations and upgrades have been made to the external scanning microbeam of INFN-LABEC laboratory in Florence, enriching the existing PIXE, PIGE, BS, IBIL set-up with complementary techniques, when possible allowing for simultaneous multi-technique analyses. We developed a system, compatible with the existing set-up, for the out-of-vacuum detection of the forward scattered particles. This system makes feasible the external-STIM (Scanning Transmission Ion Microscopy) and external-FS (Forward Scattering), now both available at our beamline. Test measurements are shortly presented.

  13. Solar array stepping to minimize array excitation

    Science.gov (United States)

    Bhat, Mahabaleshwar K. P. (Inventor); Liu, Tung Y. (Inventor); Plescia, Carl T. (Inventor)

    1989-01-01

    Mechanical oscillations of a mechanism containing a stepper motor, such as a solar-array powered spacecraft, are reduced and minimized by the execution of step movements in pairs of steps, the period between steps being equal to one-half of the period of torsional oscillation of the mechanism. Each pair of steps is repeated at needed intervals to maintain desired continuous movement of the portion of elements to be moved, such as the solar array of a spacecraft. In order to account for uncertainty as well as slow change in the period of torsional oscillation, a command unit may be provided for varying the interval between steps in a pair.

  14. Comparative Dosimetric Estimates of a 25 keV Electron Micro-beam with three Monte Carlo Codes

    Energy Technology Data Exchange (ETDEWEB)

    Mainardi, Enrico; Donahue, Richard J.; Blakely, Eleanor A.

    2002-09-11

    The calculations presented compare the different performances of the three Monte Carlo codes PENELOPE-1999, MCNP-4C and PITS, for the evaluation of Dose profiles from a 25 keV electron micro-beam traversing individual cells. The overall model of a cell is a water cylinder equivalent for the three codes but with a different internal scoring geometry: hollow cylinders for PENELOPE and MCNP, whereas spheres are used for the PITS code. A cylindrical cell geometry with scoring volumes with the shape of hollow cylinders was initially selected for PENELOPE and MCNP because of its superior simulation of the actual shape and dimensions of a cell and for its improved computer-time efficiency if compared to spherical internal volumes. Some of the transfer points and energy transfer that constitute a radiation track may actually fall in the space between spheres, that would be outside the spherical scoring volume. This internal geometry, along with the PENELOPE algorithm, drastically reduced the computer time when using this code if comparing with event-by-event Monte Carlo codes like PITS. This preliminary work has been important to address dosimetric estimates at low electron energies. It demonstrates that codes like PENELOPE can be used for Dose evaluation, even with such small geometries and energies involved, which are far below the normal use for which the code was created. Further work (initiated in Summer 2002) is still needed however, to create a user-code for PENELOPE that allows uniform comparison of exact cell geometries, integral volumes and also microdosimetric scoring quantities, a field where track-structure codes like PITS, written for this purpose, are believed to be superior.

  15. Focal plane array with modular pixel array components for scalability

    Science.gov (United States)

    Kay, Randolph R; Campbell, David V; Shinde, Subhash L; Rienstra, Jeffrey L; Serkland, Darwin K; Holmes, Michael L

    2014-12-09

    A modular, scalable focal plane array is provided as an array of integrated circuit dice, wherein each die includes a given amount of modular pixel array circuitry. The array of dice effectively multiplies the amount of modular pixel array circuitry to produce a larger pixel array without increasing die size. Desired pixel pitch across the enlarged pixel array is preserved by forming die stacks with each pixel array circuitry die stacked on a separate die that contains the corresponding signal processing circuitry. Techniques for die stack interconnections and die stack placement are implemented to ensure that the desired pixel pitch is preserved across the enlarged pixel array.

  16. Micromirror array for protein micro array fabrication

    Science.gov (United States)

    Lee, Kook-Nyung; Shin, Dong-Sik; Lee, Yoon-Sik; Kim, Yong-Kweon

    2003-05-01

    We have designed, fabricated and characterized a micromirror array for protein microarray fabrication that has a simple structure, and the straightforward fabrication process for the mirror will allow the use of low-cost mirrors in protein pattern applications. The characteristics of an exposure system utilizing the micromirror array have been demonstrated by means of an experiment employing a photoresist that is in general use in the semiconductor industry. The micromirror dimensions were 54 × 54 mum2, with a 30 mum separation between mirrors, and a 5.5 mum gap from the bottom electrode so that the mirror had an approximately 10° deflection angle. The size and separation of the mirror were designed in consideration of the protein pattern size and pitch, in contrast with the commercial Texas Instruments Digital Light Processor, which is utilized in the components of projection display systems. The exposure system combined with the micromirror has been used in the photochemical synthesis of chemical ligands via protein immobilization on a chip. Several photosynthesis experiments for peptide array synthesis have been carried out using the micromirror array. Parallel experiments on photochemical ligand synthesis on a chip can easily be performed in the laboratory using this exposure system.

  17. Triggering the GRANDE array

    International Nuclear Information System (INIS)

    Wilson, C.L.; Bratton, C.B.; Gurr, J.; Kropp, W.; Nelson, M.; Sobel, H.; Svoboda, R.; Yodh, G.; Burnett, T.; Chaloupka, V.; Wilkes, R.J.; Cherry, M.; Ellison, S.B.; Guzik, T.G.; Wefel, J.; Gaidos, J.; Loeffler, F.; Sembroski, G.; Goodman, J.; Haines, T.J.; Kielczewska, D.; Lane, C.; Steinberg, R.; Lieber, M.; Nagle, D.; Potter, M.; Tripp, R.

    1990-01-01

    A brief description of the Gamma Ray And Neutrino Detector Experiment (GRANDE) is presented. The detector elements and electronics are described. The trigger logic for the array is then examined. The triggers for the Gamma Ray and the Neutrino portions of the array are treated separately. (orig.)

  18. Shock melting of K-feldspar and interlacing with cataclastically deformed plagioclase in granitic rocks at Toqqusap Nunaa, southern West Greenland: Implications for the genesis of the Maniitsoq structure

    Science.gov (United States)

    Keulen, Nynke; Garde, Adam A.; Jørgart, Tommy

    2015-11-01

    Folded sheets of Mesoarchaean, leucocratic plagioclase-K-feldspar-mesoperthite-bearing granitic rocks in the Toqqusap Nunaa area of the Maniitsoq structure, West Greenland, are characterised by their very fine grain sizes and microstructures without normal igneous or planar/linear tectonic fabrics. Quartz forms equidimensional and branching, ductilely deformed aggregates and bifurcating panels with protrusions, constrictions and chains of ball-shaped grains with healed, radiating intergranular fractures. Plagioclase (An10-20) was cataclastically deformed and comminuted, whereas K-feldspar and mesoperthite are devoid of cataclastic microstructures. K-feldspar forms dispersed, highly irregular grains with numerous cusps and saddles, indicating almost ubiquitous direct (shock) melting of this mineral. It is commonly located along former fractures in plagioclase, resulting in an 'interlaced' feldspar microstructure with contact shapes indicating subsequent melting of plagioclase directly adjacent to K-feldspar. Mesoperthite forms separate, rounded, and irregular grains with protrusions and cusped margins indicating crystallisation from melts. Some mesoperthite grains are texturally and compositionally heterogeneous and contain internal lenses of K-feldspar and/or plagioclase. Other mesoperthite grains comprise coarsened, 'unzipped' areas, presumably due to localised, fluid-controlled dissolution-reprecipitation processes. The ternary feldspar precursor of the mesoperthite is interpreted as having crystallised from variably effectively mixed K-feldspar shock melts and plagioclase contact melts. Direct melting of K-feldspar, but no whole-rock melting, requires shock metamorphism with a short-lived temperature excursion to above the melting temperature of K-feldspar (~ 1300 °C). The presence of three different feldspar species and absence of chemical zonation, magmatic mantling, or metamorphic coronas furthermore hinders interpretations solely by means of endogenic

  19. Micromachined electrode array

    Science.gov (United States)

    Okandan, Murat; Wessendorf, Kurt O.

    2007-12-11

    An electrode array is disclosed which has applications for neural stimulation and sensing. The electrode array, in certain embodiments, can include a plurality of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. In other embodiments of the electrode array, the electrodes can be fixed to the substrate. The electrode array can be formed from a combination of bulk and surface micromachining, and can include electrode tips having an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis.

  20. Diffusion-time-resolved ion-beam-induced charge collection from stripe-like test junctions induced by heavy-ion microbeams

    International Nuclear Information System (INIS)

    Guo, B.N.; El Bouanani, M.; Renfrow, S.N.; Nigam, M.; Walsh, D.S.; Doyle, B.L.; Duggan, J.L.; McDaniel, F.D.

    2001-01-01

    To design more radiation-tolerant integrated circuits (ICs), it is necessary to design and test accurate models of ionizing-radiation-induced charge collection dynamics. A new technique, diffusion-time-resolved ion-beam-induced charge collection (DTRIBICC), is used to measure the average arrival time of the diffused charge, which is related to the average time of the arrival carrier density at the junction. Specially designed stripe-like test junctions are studied using a 12 MeV carbon microbeam with a spot size of ∼1 μm. The relative arrival time of ion-generated charge and the collected charge are measured using a multiple parameter data acquisition system. A 2-D device simulation code, MEDICI, is used to calculate the charge collection dynamics on the stripe-like test junctions. The simulations compare well with experimental microbeam measurements. The results show the importance of the diffused charge collection by junctions, which is especially significant for single-event upsets (SEUs) and multiple-event upsets (MEUs) in electronic devices. The charge sharing results also indicate that stripe-like junctions may be used as position-sensitive detectors with a resolution of ∼0.1 μm

  1. Microscopic residual stress evolution during deformation process of an Fe---Mn---Si---Cr shape memory alloy investigated using white X-ray microbeam diffraction

    International Nuclear Information System (INIS)

    Kwon, E.P.; Sato, S.; Fujieda, S.; Shinoda, K.; Kajiwara, K.; Sato, M.; Suzuki, S.

    2013-01-01

    Microscopic residual stress evolution in different austenite (γ) grains during shape memory process in an Fe---Mn---Si---Cr alloy was investigated using the white X-ray microbeam diffraction technique. The use of high-energy white X-ray microbeam with small beam size allowed us to measure the microscopic residual stress in coarse γ grains with specific orientation. After tensile deformation large compressive residual stress was evolved in γ grains due to the formation of stress-induced ε martensite, but upon recovery heating it almost disappeared as a result of reverse transformation of martensite. The magnitude of compressive residual stress was higher in grains with orientations close to 〈144〉 and 〈233〉 orientations than in a grain with near 〈001〉 orientation. Analysis of the microstructure of each grain using electron backscattering diffraction suggested that the difference in the magnitude of compressive residual stress could be attributed to different martensitic transformation characteristics in the grains

  2. Real-time observation of irradiated Hela-cell Modified by Fluorescent ubiquitination-based Cell Cycle Indicator Using Synchrotron X-Ray Microbeam

    International Nuclear Information System (INIS)

    Narita, A.; Noguchi, M.; Kaminaga, K.; Yokoya, A.; Kobayashi, K.; Usami, N.; Fujii, K.

    2015-01-01

    Fluorescent ubiquitination-based cell-cycle indicator (FUCCI) human cancer (HeLa) cells (red indicates G1; green, S/G2) were exposed to a synchrotron X-ray microbeam. Cells in either G1 or S/G2 were irradiated selectively according to their colour in the same microscopic field. Time-lapse micrographs of the irradiated cells were acquired for 24 h after irradiation. For fluorescent immunostaining, phosphorylated histone proteins (γ-H2AX) indicated the induction of DNA double-strand breaks. The cell cycle was arrested by irradiation at S/G2. In contrast, cells irradiated at G1 progressed to S/G2. The foci were induced in cells irradiated at both G1 and S/G2, suggesting that the G1-S (or S) checkpoint pathway does not function in HeLa cells due to the fact that the cells are functionally p53 deficient, even though X-ray microbeam irradiation significantly induces double-strand breaks. These results demonstrate that single FUCCI cell exposure and live cell imaging are powerful methods for studying the effects of radiation on the cell cycle. (authors)

  3. Beam size reduction of a several hundred-keV compact ion microbeam system by improving the extraction condition in an ion source

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Yasuyuki; Ohkubo, Takeru; Kamiya, Tomihiro; Saitoh, Yuichi

    2015-04-01

    A several hundred-keV compact ion microbeam system with a three-stage acceleration lens has been developed to form an ion beam of several micrometers in diameter. In a previous study of the Ohkubo et al. (2013) and Ishii et al. (2014), a hydrogen beam of 143 keV having 17 μm diameter was experimentally formed using such a microbeam system. It was demonstrated that a three-stage acceleration lens functioned as a focusing lens and indicated that the beam diameter (hereinafter referred to as the “beam size”) depended on the extraction voltage to generate the ion beam and the vacuum pressure in the extraction space in a plasma-type ion source. In this study, the hydrogen beam sizes were experimentally measured at 130 keV as functions of the extraction voltage and vacuum pressure to form the beam size with several micrometers in diameter. These two relationships showed that beam sizes were reduced in the extraction voltage range of 400–500 V and when the vacuum pressure was lowered to a minimum value of 5.33 × 10{sup −5} Pa. In addition, the result showed that the beam size was dominantly influenced by the vacuum pressure. Consequently, a hydrogen beam 5.8 μm in diameter was formed experimentally—the smallest beam yet obtained.

  4. Sensor array signal processing

    CERN Document Server

    Naidu, Prabhakar S

    2009-01-01

    Chapter One: An Overview of Wavefields 1.1 Types of Wavefields and the Governing Equations 1.2 Wavefield in open space 1.3 Wavefield in bounded space 1.4 Stochastic wavefield 1.5 Multipath propagation 1.6 Propagation through random medium 1.7 ExercisesChapter Two: Sensor Array Systems 2.1 Uniform linear array (ULA) 2.2 Planar array 2.3 Distributed sensor array 2.4 Broadband sensor array 2.5 Source and sensor arrays 2.6 Multi-component sensor array2.7 ExercisesChapter Three: Frequency Wavenumber Processing 3.1 Digital filters in the w-k domain 3.2 Mapping of 1D into 2D filters 3.3 Multichannel Wiener filters 3.4 Wiener filters for ULA and UCA 3.5 Predictive noise cancellation 3.6 Exercises Chapter Four: Source Localization: Frequency Wavenumber Spectrum4.1 Frequency wavenumber spectrum 4.2 Beamformation 4.3 Capon's w-k spectrum 4.4 Maximum entropy w-k spectrum 4.5 Doppler-Azimuth Processing4.6 ExercisesChapter Five: Source Localization: Subspace Methods 5.1 Subspace methods (Narrowband) 5.2 Subspace methods (B...

  5. Piezoelectric transducer array microspeaker

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-12-19

    In this paper we present the fabrication and characterization of a piezoelectric micro-speaker. The speaker is an array of micro-machined piezoelectric membranes, fabricated on silicon wafer using advanced micro-machining techniques. Each array contains 2n piezoelectric transducer membranes, where “n” is the bit number. Every element of the array has a circular shape structure. The membrane is made out four layers: 300nm of platinum for the bottom electrode, 250nm or lead zirconate titanate (PZT), a top electrode of 300nm and a structural layer of 50

  6. Introduction to adaptive arrays

    CERN Document Server

    Monzingo, Bob; Haupt, Randy

    2011-01-01

    This second edition is an extensive modernization of the bestselling introduction to the subject of adaptive array sensor systems. With the number of applications of adaptive array sensor systems growing each year, this look at the principles and fundamental techniques that are critical to these systems is more important than ever before. Introduction to Adaptive Arrays, 2nd Edition is organized as a tutorial, taking the reader by the hand and leading them through the maze of jargon that often surrounds this highly technical subject. It is easy to read and easy to follow as fundamental concept

  7. Photonic Crystal Nanocavity Arrays

    National Research Council Canada - National Science Library

    Altug, Hatice; Vuckovic, Jelena

    2006-01-01

    We recently proposed two-dimensional coupled photonic crystal nanocavity arrays as a route to achieve a slow-group velocity of light in all crystal directions, thereby enabling numerous applications...

  8. Flexible retinal electrode array

    Science.gov (United States)

    Okandan, Murat [Albuquerque, NM; Wessendorf, Kurt O [Albuquerque, NM; Christenson, Todd R [Albuquerque, NM

    2006-10-24

    An electrode array which has applications for neural stimulation and sensing. The electrode array can include a large number of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. The electrode array can be formed from a combination of bulk and surface micromachining, with electrode tips that can include an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis where the electrodes can be tailored to provide a uniform gentle contact pressure with optional sensing of this contact pressure at one or more of the electrodes.

  9. Protein Functionalized Nanodiamond Arrays

    Directory of Open Access Journals (Sweden)

    Liu YL

    2010-01-01

    Full Text Available Abstract Various nanoscale elements are currently being explored for bio-applications, such as in bio-images, bio-detection, and bio-sensors. Among them, nanodiamonds possess remarkable features such as low bio-cytotoxicity, good optical property in fluorescent and Raman spectra, and good photostability for bio-applications. In this work, we devise techniques to position functionalized nanodiamonds on self-assembled monolayer (SAMs arrays adsorbed on silicon and ITO substrates surface using electron beam lithography techniques. The nanodiamond arrays were functionalized with lysozyme to target a certain biomolecule or protein specifically. The optical properties of the nanodiamond-protein complex arrays were characterized by a high throughput confocal microscope. The synthesized nanodiamond-lysozyme complex arrays were found to still retain their functionality in interacting with E. coli.

  10. Expandable LED array interconnect

    Science.gov (United States)

    Yuan, Thomas Cheng-Hsin; Keller, Bernd

    2011-03-01

    A light emitting device that can function as an array element in an expandable array of such devices. The light emitting device comprises a substrate that has a top surface and a plurality of edges. Input and output terminals are mounted to the top surface of the substrate. Both terminals comprise a plurality of contact pads disposed proximate to the edges of the substrate, allowing for easy access to both terminals from multiple edges of the substrate. A lighting element is mounted to the top surface of the substrate. The lighting element is connected between the input and output terminals. The contact pads provide multiple access points to the terminals which allow for greater flexibility in design when the devices are used as array elements in an expandable array.

  11. A microbeam grazing-incidence approach to L-shell x-ray fluorescence measurements of lead concentration in bone and soft tissue phantoms.

    Science.gov (United States)

    Gherase, Mihai Raul; Al-Hamdani, Summer

    2018-02-06

    L-shell x-ray fluorescence (LXRF) is a non-invasive approach to lead (Pb) concentration measurements in the human bone. The first studies were published in the early 1980s. In the same period the K-shell x-ray fluorescence (KXRF) method using a Cd-109 radionuclide source was developed and later improved and refined. Lower sensitivity and calibration difficulties associated with the LXRF method led the KXRF to be the most adopted method for in vivo human bone Pb studies. In the present study a microbeam-based grazing-incidence approach to Pb LXRF measurements was investigated. The microbeam produced by an integrated x-ray tube and polycapillary x-ray lens (PXL) unit was used to excite cylindrical plaster-of-Paris (poP) bone phantoms doped with Pb in seven concentrations: 0, 8, 16, 26, 34, 59, and 74 µg/g. Two 1 mm- and 3 mm-thick cylindrical shell soft tissue phantoms were made out of polyoxymethylene (POM) plastic. Three bone-soft tissue phantom sets corresponding to the 0, 1, and 3 mm POM thickness values resulted. Each phantom was placed between the microbeam and the detector; its position was controlled using a positioning stage. Small steps (0.1-0.5 mm) and short 30 s x-ray spectra acquisitions were used to find the optimal phantom position according to the maximum observed Sr Kα peak height. At the optimal geometry, five 180 s x-ray spectra were acquired for each phantom set. Calibration lines were obtained using the fitted peak heights of the two observed Pb Lα and Pb Lβ peaks. The lowest detection limit (DL) values were (2.9±0.2), (4.9±0.3), and (23±3) µg/g, respectively. The order of magnitude of the absorbed radiation dose in the POM plastic for the 180 s irradiation was estimated to be <1 mGy. The results are superior to a relatively recently-published LXRF phantom study and show promise for future designs of in vivo LXRF measurements. Creative Commons Attribution license.

  12. Testing of focal plane arrays

    International Nuclear Information System (INIS)

    Merriam, J.D.

    1988-01-01

    Problems associated with the testing of focal plane arrays are briefly examined with reference to the instrumentation and measurement procedures. In particular, the approach and instrumentation used as the Naval Ocean Systems Center is presented. Most of the measurements are made with flooded illumination on the focal plane array. The array is treated as an ensemble of individual pixels, data being taken on each pixel and array averages and standard deviations computed for the entire array. Data maps are generated, showing the pixel data in the proper spatial position on the array and the array statistics

  13. Photovoltaic array reliability optimization

    Science.gov (United States)

    Ross, R. G., Jr.

    1982-01-01

    An overview of the photovoltaic array reliability problem is presented, and a high reliability/minimum cost approach to this problem is presented. Design areas covered are cell failure, interconnect fatigue, and electrical insulation breakdown, and three solution strategies are discussed. The first involves controlling component failures in the solar cell (cell cracking, cell interconnects) and at the module level (must be statistically treated). Second, a fault tolerant circuit is designed which reduces array degradation, improves module yield losses, and controls hot-spot heating. Third, cost optimum module replacement strategies are also effective in reducing array degradation. This can be achieved by minimizing the life-cycle energy cost of the photovoltaic system. The integration of these solutions is aimed at reducing the 0.01% failure rate.

  14. Coaxial phased array antenna

    Science.gov (United States)

    Ellis, H., Jr.

    1980-08-01

    A coaxial antenna array for communicating circularly polarized electromagnetic radiation is disclosed. A pair of open ended antenna cavities is coaxially constructed and operates by excitation of linear radiation elements arranged within each of the cavities. A pair of crossed dipole radiation devices is centered within the inner cavity and operated by means of a phase shifting network circuit to transmit as well as receive circularly polarized radiation. Four monopole radiation devices are symmetrically arranged to operate in the outer cavity in phase quadrature by means of the phase shifting network circuit to both transmit and receive circularly polarized electromagnetic radiation. Combined operation of the two antenna cavities with a 180 deg phase differential between the fields related to the two antenna cavities provides a broad beam, relatively wide frequency bandwidth communication capability. Particular embodiments disclosed feature a generally square cavity array as well as a circular cavity array.

  15. Micromachined droplet ejector arrays

    Science.gov (United States)

    Perçin, Gökhan; Yaralioglu, Göksenin G.; Khuri-Yakub, Butrus T.

    2002-12-01

    In this article we present a micromachined flextensional droplet ejector array used to eject liquids. By placing a fluid behind one face of a vibrating circular plate that has an orifice at its center, we achieve continuous ejection of the fluid. We present results of ejection of water and isopropanol. The ejector is harmless to sensitive fluids and can be used to eject fuels, organic polymers, photoresists, low-k dielectrics, adhesives, and chemical and biological samples. Micromachined two-dimensional array flextensional droplet ejectors were realized using planar silicon micromachining techniques. Typical resonant frequency of the micromachined device ranges from 400 kHz to 4.5 MHz. The ejections of water through a 4 μm diameter orifice at 3.45 MHz and a 10 μm diameter orifice at 2.15 MHz were demonstrated by using the developed micromachined two-dimensional array ejectors.

  16. The Effect of an Added Mass on the Frequency Shifts of a Clamped-Clamped Microbeam for Bio-Mass Detection

    KAUST Repository

    Bouchaala, Adam M.

    2016-12-05

    We present analytical formulations to calculate the induced resonance frequency shifts of electrically actuated clamped-clamped microbeams due to an added mass. Based on the Euler-Bernoulli beam theory, we investigate the linear dynamic responses of the beams added masses, which are modeled as discrete point masses. Analytical expressions based on perturbation techniques and a one-mode Galerkin approximation are developed to calculate accurately the frequency shifts under a DC voltage as a function of the added mass and position. The analytical results are compared to numerical solution of the eigenvalue problem. Results are shown for the fundamental as well as the higher-order modes of the beams. The results indicate a significant increase in the frequency shift, and hence the sensitivity of detection, when scaling down to nano scale and using higher-order modes.

  17. Synchrotron radiation microbeam X-ray diffraction for nondestructive assessments of local structural properties of faceted InGaN/GaN quantum wells

    Science.gov (United States)

    Sakaki, Atsushi; Funato, Mitsuru; Kawamura, Tomoaki; Araki, Jun; Kawakami, Yoichi

    2018-03-01

    Synchrotron radiation (SR) X-ray diffraction with a sub-µm spatial resolution is used to nondestructively evaluate the local thickness and alloy composition of three-dimensionally faceted InGaN/GaN quantum wells (QWs). The (0001) facet QW on a trapezoidal structure composed of (0001), \\{ 11\\bar{2}2\\} , and \\{ 11\\bar{2}0\\} facets is nonuniform, most likely owing to the migration of adatoms between facets. The thickness and composition markedly vary within a short distance for the \\{ 11\\bar{2}2\\} facet QW of another pyramidal structure. The QW parameters acquired by SR microbeam X-ray diffraction reproduce the local emission property assessed by cathodoluminescence, thereby indicating the high reliability of this method.

  18. Wire Array Photovoltaics

    Science.gov (United States)

    Turner-Evans, Dan

    Over the past five years, the cost of solar panels has dropped drastically and, in concert, the number of installed modules has risen exponentially. However, solar electricity is still more than twice as expensive as electricity from a natural gas plant. Fortunately, wire array solar cells have emerged as a promising technology for further lowering the cost of solar. Si wire array solar cells are formed with a unique, low cost growth method and use 100 times less material than conventional Si cells. The wires can be embedded in a transparent, flexible polymer to create a free-standing array that can be rolled up for easy installation in a variety of form factors. Furthermore, by incorporating multijunctions into the wire morphology, higher efficiencies can be achieved while taking advantage of the unique defect relaxation pathways afforded by the 3D wire geometry. The work in this thesis shepherded Si wires from undoped arrays to flexible, functional large area devices and laid the groundwork for multijunction wire array cells. Fabrication techniques were developed to turn intrinsic Si wires into full p-n junctions and the wires were passivated with a-Si:H and a-SiNx:H. Single wire devices yielded open circuit voltages of 600 mV and efficiencies of 9%. The arrays were then embedded in a polymer and contacted with a transparent, flexible, Ni nanoparticle and Ag nanowire top contact. The contact connected >99% of the wires in parallel and yielded flexible, substrate free solar cells featuring hundreds of thousands of wires. Building on the success of the Si wire arrays, GaP was epitaxially grown on the material to create heterostructures for photoelectrochemistry. These cells were limited by low absorption in the GaP due to its indirect bandgap, and poor current collection due to a diffusion length of only 80 nm. However, GaAsP on SiGe offers a superior combination of materials, and wire architectures based on these semiconductors were investigated for multijunction

  19. In situ biological dose mapping estimates the radiation burden delivered to 'spared' tissue between synchrotron X-ray microbeam radiotherapy tracks.

    Directory of Open Access Journals (Sweden)

    Kai Rothkamm

    Full Text Available Microbeam radiation therapy (MRT using high doses of synchrotron X-rays can destroy tumours in animal models whilst causing little damage to normal tissues. Determining the spatial distribution of radiation doses delivered during MRT at a microscopic scale is a major challenge. Film and semiconductor dosimetry as well as Monte Carlo methods struggle to provide accurate estimates of dose profiles and peak-to-valley dose ratios at the position of the targeted and traversed tissues whose biological responses determine treatment outcome. The purpose of this study was to utilise γ-H2AX immunostaining as a biodosimetric tool that enables in situ biological dose mapping within an irradiated tissue to provide direct biological evidence for the scale of the radiation burden to 'spared' tissue regions between MRT tracks. Γ-H2AX analysis allowed microbeams to be traced and DNA damage foci to be quantified in valleys between beams following MRT treatment of fibroblast cultures and murine skin where foci yields per unit dose were approximately five-fold lower than in fibroblast cultures. Foci levels in cells located in valleys were compared with calibration curves using known broadbeam synchrotron X-ray doses to generate spatial dose profiles and calculate peak-to-valley dose ratios of 30-40 for cell cultures and approximately 60 for murine skin, consistent with the range obtained with conventional dosimetry methods. This biological dose mapping approach could find several applications both in optimising MRT or other radiotherapeutic treatments and in estimating localised doses following accidental radiation exposure using skin punch biopsies.

  20. A review of array radars

    Science.gov (United States)

    Brookner, E.

    1981-10-01

    Achievements in the area of array radars are illustrated by such activities as the operational deployment of the large high-power, high-range-resolution Cobra Dane; the operational deployment of two all-solid-state high-power, large UHF Pave Paws radars; and the development of the SAM multifunction Patriot radar. This paper reviews the following topics: array radars steered in azimuth and elevation by phase shifting (phase-phase steered arrays); arrays steered + or - 60 deg, limited scan arrays, hemispherical coverage, and omnidirectional coverage arrays; array radars steering electronically in only one dimension, either by frequency or by phase steering; and array radar antennas which use no electronic scanning but instead use array antennas for achieving low antenna sidelobes.

  1. Array Theory and Nial

    DEFF Research Database (Denmark)

    Falster, Peter; Jenkins, Michael

    1999-01-01

    This report is the result of collaboration between the authors during the first 8 months of 1999 when M. Jenkins was visiting professor at DTU. The report documents the development of a tool for the investigation of array theory concepts and in particular presents various approaches to choose...

  2. Photoacoustic imaging of brachytherapy seeds using a channel-domain ultrasound array system

    Science.gov (United States)

    Harrison, Tyler; Zemp, Roger J.

    2011-03-01

    Brachytherapy is a technique commonly used in the treatment of prostate cancer that relies on the precise placement of small radioactive seeds near the tumor location. The advantage of this technique over traditional radiation therapies is that treatment can be continuous and uniform, resulting in fewer clinic visits and a shorter treatment duration. Two important phases of this treatment are needle guidance for implantation, and post-placement verification for dosimetry. Ultrasound is a common imaging modality used for these purposes, but it can be difficult to distinguish the seeds from surrounding tissues, often requiring other imaging techniques such as MRI or CT. Photoacoustic imaging may offer a viable alternative. Using a photoacoustic system based on an L7- 4 array transducer and a realtime ultrasound array system capable of parallel channel data acquisition streamed to a multi-core computer via PCI-express, we have demonstrated imaging of these seeds at an ultrasound depth of 16 mm and laser penetration depths ranging up to 50 mm in chicken tissue with multiple optical wavelengths. Ultrasound and photoacoustic images are coregistered via an interlaced pulse sequence. Two laser pulses are used to form a photoacoustic image, and at these depths, the brachytherapy seeds are detected with a signal-to-noise ratio of over 26dB. To obtain this result, 1064nm light was used with a fluence of 100mJ/cm2, the ANSI limit for human skin exposure at this wavelength. This study demonstrates the potential for photoacoustic imaging as a candidate technology for brachytherapy seed placement guidance and verification.

  3. Radar techniques using array antennas

    CERN Document Server

    Wirth, Wulf-Dieter

    2013-01-01

    Radar Techniques Using Array Antennas is a thorough introduction to the possibilities of radar technology based on electronic steerable and active array antennas. Topics covered include array signal processing, array calibration, adaptive digital beamforming, adaptive monopulse, superresolution, pulse compression, sequential detection, target detection with long pulse series, space-time adaptive processing (STAP), moving target detection using synthetic aperture radar (SAR), target imaging, energy management and system parameter relations. The discussed methods are confirmed by simulation stud

  4. Timed arrays wideband and time varying antenna arrays

    CERN Document Server

    Haupt, Randy L

    2015-01-01

    Introduces timed arrays and design approaches to meet the new high performance standards The author concentrates on any aspect of an antenna array that must be viewed from a time perspective. The first chapters briefly introduce antenna arrays and explain the difference between phased and timed arrays. Since timed arrays are designed for realistic time-varying signals and scenarios, the book also reviews wideband signals, baseband and passband RF signals, polarization and signal bandwidth. Other topics covered include time domain, mutual coupling, wideband elements, and dispersion. The auth

  5. Seismometer array station processors

    International Nuclear Information System (INIS)

    Key, F.A.; Lea, T.G.; Douglas, A.

    1977-01-01

    A description is given of the design, construction and initial testing of two types of Seismometer Array Station Processor (SASP), one to work with data stored on magnetic tape in analogue form, the other with data in digital form. The purpose of a SASP is to detect the short period P waves recorded by a UK-type array of 20 seismometers and to edit these on to a a digital library tape or disc. The edited data are then processed to obtain a rough location for the source and to produce seismograms (after optimum processing) for analysis by a seismologist. SASPs are an important component in the scheme for monitoring underground explosions advocated by the UK in the Conference of the Committee on Disarmament. With digital input a SASP can operate at 30 times real time using a linear detection process and at 20 times real time using the log detector of Weichert. Although the log detector is slower, it has the advantage over the linear detector that signals with lower signal-to-noise ratio can be detected and spurious large amplitudes are less likely to produce a detection. It is recommended, therefore, that where possible array data should be recorded in digital form for input to a SASP and that the log detector of Weichert be used. Trial runs show that a SASP is capable of detecting signals down to signal-to-noise ratios of about two with very few false detections, and at mid-continental array sites it should be capable of detecting most, if not all, the signals with magnitude above msub(b) 4.5; the UK argues that, given a suitable network, it is realistic to hope that sources of this magnitude and above can be detected and identified by seismological means alone. (author)

  6. Solar collector array

    Science.gov (United States)

    Hall, John Champlin; Martins, Guy Lawrence

    2015-09-06

    A method and apparatus for efficient manufacture, assembly and production of solar energy. In one aspect, the apparatus may include a number of modular solar receiver assemblies that may be separately manufactured, assembled and individually inserted into a solar collector array housing shaped to receive a plurality of solar receivers. The housing may include optical elements for focusing light onto the individual receivers, and a circuit for electrically connecting the solar receivers.

  7. Array processor architecture

    Science.gov (United States)

    Barnes, George H. (Inventor); Lundstrom, Stephen F. (Inventor); Shafer, Philip E. (Inventor)

    1983-01-01

    A high speed parallel array data processing architecture fashioned under a computational envelope approach includes a data base memory for secondary storage of programs and data, and a plurality of memory modules interconnected to a plurality of processing modules by a connection network of the Omega gender. Programs and data are fed from the data base memory to the plurality of memory modules and from hence the programs are fed through the connection network to the array of processors (one copy of each program for each processor). Execution of the programs occur with the processors operating normally quite independently of each other in a multiprocessing fashion. For data dependent operations and other suitable operations, all processors are instructed to finish one given task or program branch before all are instructed to proceed in parallel processing fashion on the next instruction. Even when functioning in the parallel processing mode however, the processors are not locked-step but execute their own copy of the program individually unless or until another overall processor array synchronization instruction is issued.

  8. Spaceborne Processor Array

    Science.gov (United States)

    Chow, Edward T.; Schatzel, Donald V.; Whitaker, William D.; Sterling, Thomas

    2008-01-01

    A Spaceborne Processor Array in Multifunctional Structure (SPAMS) can lower the total mass of the electronic and structural overhead of spacecraft, resulting in reduced launch costs, while increasing the science return through dynamic onboard computing. SPAMS integrates the multifunctional structure (MFS) and the Gilgamesh Memory, Intelligence, and Network Device (MIND) multi-core in-memory computer architecture into a single-system super-architecture. This transforms every inch of a spacecraft into a sharable, interconnected, smart computing element to increase computing performance while simultaneously reducing mass. The MIND in-memory architecture provides a foundation for high-performance, low-power, and fault-tolerant computing. The MIND chip has an internal structure that includes memory, processing, and communication functionality. The Gilgamesh is a scalable system comprising multiple MIND chips interconnected to operate as a single, tightly coupled, parallel computer. The array of MIND components shares a global, virtual name space for program variables and tasks that are allocated at run time to the distributed physical memory and processing resources. Individual processor- memory nodes can be activated or powered down at run time to provide active power management and to configure around faults. A SPAMS system is comprised of a distributed Gilgamesh array built into MFS, interfaces into instrument and communication subsystems, a mass storage interface, and a radiation-hardened flight computer.

  9. Lectin-Array Blotting.

    Science.gov (United States)

    Pazos, Raquel; Echevarria, Juan; Hernandez, Alvaro; Reichardt, Niels-Christian

    2017-09-01

    Aberrant protein glycosylation is a hallmark of cancer, infectious diseases, and autoimmune or neurodegenerative disorders. Unlocking the potential of glycans as disease markers will require rapid and unbiased glycoproteomics methods for glycan biomarker discovery. The present method is a facile and rapid protocol for qualitative analysis of protein glycosylation in complex biological mixtures. While traditional lectin arrays only provide an average signal for the glycans in the mixture, which is usually dominated by the most abundant proteins, our method provides individual lectin binding profiles for all proteins separated in the gel electrophoresis step. Proteins do not have to be excised from the gel for subsequent analysis via the lectin array but are transferred by contact diffusion from the gel to a glass slide presenting multiple copies of printed lectin arrays. Fluorescently marked glycoproteins are trapped by the printed lectins via specific carbohydrate-lectin interactions and after a washing step their binding profile with up to 20 lectin probes is analyzed with a fluorescent scanner. The method produces the equivalent of 20 lectin blots in a single experiment, giving detailed insight into the binding epitopes present in the fractionated proteins. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  10. Radiation from waveguide arrays

    International Nuclear Information System (INIS)

    Brambilla, M.

    1977-07-01

    The theory of phased waveguide arrays (the 'Grill'), developed in view of Lower Hybrid Heating of toroidal plasmas, is applied to two simple cases, in order to gain insight on field distributions and power flow. First, the far-field radiation pattern of the Grill towards an empty half-space is evaluated. Next, the excitation of a passive waveguide by a Grill mounted in a T configuration is considered. These results constitue two examples of exact solutions of Maxwell's equations in relatively complex geometry

  11. Molecular logic gate arrays.

    Science.gov (United States)

    de Silva, A Prasanna

    2011-03-01

    Chemists are now able to emulate the ideas and instruments of mathematics and computer science with molecules. The integration of molecular logic gates into small arrays has been a growth area during the last few years. The design principles underlying a collection of these cases are examined. Some of these computing molecules are applicable in medical- and biotechnologies. Cases of blood diagnostics, 'lab-on-a-molecule' systems, and molecular computational identification of small objects are included. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. The Long Wavelength Array

    Science.gov (United States)

    Pihlström, Ylva

    The Long Wavelength Array (LWA) will be a new, open-skies, user-oriented aperture synthesis instrument dedicated to explore frequencies between 20 and 80 MHz. The LWA will provide high temporal (millisecond or better) and high spatial resolution (arcsecond) and mJy-level sensitivity. The LWA key science areas include acceleration, propagation, and turbulence in the ISM; the high-redshift Universe; planetary, solar and space science; and the transient universe at radio wavelengths. In addition, key goals of the LWA are as a training ground for the next generation of radio astronomers and to re-invigorate radio astronomy in the US at the university level. The LWA will be operated by the University of New Mexico on behalf of the South West Consortium (SWC), thereby providing opportunities for students within the fields of astronomy, computer science and electrical engineering. Currently, in its first year of construction funding, the LWA team is now bringing up the first station near the Very Large Array site in the southwest US.

  13. Selecting Sums in Arrays

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Jørgensen, Allan Grønlund

    2008-01-01

    In an array of n numbers each of the \\binomn2+nUnknown control sequence '\\binom' contiguous subarrays define a sum. In this paper we focus on algorithms for selecting and reporting maximal sums from an array of numbers. First, we consider the problem of reporting k subarrays inducing the k largest...... sums among all subarrays of length at least l and at most u. For this problem we design an optimal O(n + k) time algorithm. Secondly, we consider the problem of selecting a subarray storing the k’th largest sum. For this problem we prove a time bound of Θ(n · max {1,log(k/n)}) by describing...... an algorithm with this running time and by proving a matching lower bound. Finally, we combine the ideas and obtain an O(n· max {1,log(k/n)}) time algorithm that selects a subarray storing the k’th largest sum among all subarrays of length at least l and at most u....

  14. Electromagnetically Clean Solar Arrays

    Science.gov (United States)

    Stem, Theodore G.; Kenniston, Anthony E.

    2008-01-01

    The term 'electromagnetically clean solar array' ('EMCSA') refers to a panel that contains a planar array of solar photovoltaic cells and that, in comparison with a functionally equivalent solar-array panel of a type heretofore used on spacecraft, (1) exhibits less electromagnetic interferences to and from other nearby electrical and electronic equipment and (2) can be manufactured at lower cost. The reduction of electromagnetic interferences is effected through a combination of (1) electrically conductive, electrically grounded shielding and (2) reduction of areas of current loops (in order to reduce magnetic moments). The reduction of cost is effected by designing the array to be fabricated as a more nearly unitary structure, using fewer components and fewer process steps. Although EMCSAs were conceived primarily for use on spacecraft they are also potentially advantageous for terrestrial applications in which there are requirements to limit electromagnetic interference. In a conventional solar panel of the type meant to be supplanted by an EMCSA panel, the wiring is normally located on the back side, separated from the cells, thereby giving rise to current loops having significant areas and, consequently, significant magnetic moments. Current-loop geometries are chosen in an effort to balance opposing magnetic moments to limit far-0field magnetic interactions, but the relatively large distances separating current loops makes full cancellation of magnetic fields problematic. The panel is assembled from bare photovoltaic cells by means of multiple sensitive process steps that contribute significantly to cost, especially if electomagnetic cleanliness is desired. The steps include applying a cover glass and electrical-interconnect-cell (CIC) sub-assemble, connecting the CIC subassemblies into strings of series-connected cells, laying down and adhesively bonding the strings onto a panel structure that has been made in a separate multi-step process, and mounting the

  15. Quantitative in Situ SEM High Cycle Fatigue: The Critical Role of Oxygen on Nanoscale-Void-Controlled Nucleation and Propagation of Small Cracks in Ni Microbeams.

    Science.gov (United States)

    Barrios, Alejandro; Gupta, Saurabh; Castelluccio, Gustavo M; Pierron, Olivier N

    2018-03-07

    This Letter presents a quantitative in situ scanning electron microscope (SEM) nanoscale high and very high cycle fatigue (HCF/VHCF) investigation of Ni microbeams under bending, using a MEMS microresonator as an integrated testing machine. The novel technique highlights ultraslow fatigue crack growth (average values down to ∼10 -14 m/cycle) that has heretofore not been reported and that indicates a discontinuous process; it also reveals strong environmental effects on fatigue lives that are 3 orders of magnitude longer in a vacuum than in air. This ultraslow fatigue regime does not follow the well documented fatigue mechanisms that rely on the common crack tip stress intensification, mediated by dislocation emission and associated with much larger crack growth rates. Instead, our study reveals fatigue nucleation and propagation mechanisms that mainly result from room temperature void formation based on vacancy condensation processes that are strongly affected by oxygen. This study therefore shows significant size effects governing the bending high/very high cycle fatigue behavior of metals at the micro- and nanoscales, whereby the stress concentration effect at the tip of a growing small fatigue crack is assumed to be greatly reduced by the effect of the bending-induced extreme stress gradients, which prevents any significant cyclic crack tip opening displacement. In this scenario, ultraslow processes relying on vacancy formation at the subsurface or in the vicinity of a crack tip and subsequent condensation into voids become the dominant fatigue mechanisms.

  16. Investigation of the Distribution of Elements in Snail Shell With the use of Synchrotron-Based, Micro-Beam X-ray Fluorescence Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Rao, D.; Swapna, M; Cesareo, R; Brunetti, A; Akatsuka, T; Yuasa, T; Takeda, T; Tromba, G; Gigante, G

    2009-01-01

    In this study, synchrotron-based micro-beam was utilized for elemental mapping of a small animal shell. A thin X-ray spot of the order of {approx}10 em was focused on the sample. With this spatial resolution and high flux throughput, the X-ray fluorescent intensities for Ca, Mn, Fe, Ni, Zn, Cr and Cu were measured using a liquid-nitrogen-cooled 13-element energy-dispersive HpGe detector. The sample is scanned in a estep-and-repeat' mode for fast elemental mapping and generated elemental maps at 8, 10 and 12 keV. All images are of 10 em resolution and the measurement time was 1 s per point. The accumulation of trace elements was investigated from the soft-tissue in small areas. Analysis of the small areas will be better suited to establish the physiology of metals in specific structures like small animal shell and the distribution of other trace elements.

  17. Dynamic behaviour of a planar micro-beam loaded by a fluid-gap: Analytical and numerical approach in a high frequency range, benchmark solutions

    Science.gov (United States)

    Novak, A.; Honzik, P.; Bruneau, M.

    2017-08-01

    Miniaturized vibrating MEMS devices, active (receivers or emitters) or passive devices, and their use for either new applications (hearing, meta-materials, consumer devices,…) or metrological purposes under non-standard conditions, are involved today in several acoustic domains. More in-depth characterisation than the classical ones available until now are needed. In this context, the paper presents analytical and numerical approaches for describing the behaviour of three kinds of planar micro-beams of rectangular shape (suspended rigid or clamped elastic planar beam) loaded by a backing cavity or a fluid-gap, surrounded by very thin slits, and excited by an incident acoustic field. The analytical approach accounts for the coupling between the vibrating structure and the acoustic field in the backing cavity, the thermal and viscous diffusion processes in the boundary layers in the slits and the cavity, the modal behaviour for the vibrating structure, and the non-uniformity of the acoustic field in the backing cavity which is modelled in using an integral formulation with a suitable Green's function. Benchmark solutions are proposed in terms of beam motion (from which the sensitivity, input impedance, and pressure transfer function can be calculated). A numerical implementation (FEM) is handled against which the analytical results are tested.

  18. Development of improved x-ray optics for analytical x-ray microbeams. CRADA final report for CRADA Number Y-1294-0283

    International Nuclear Information System (INIS)

    Carpenter, D.A.; Gao, N.; Xiao, Q.F.; Ponomarev, I.

    1996-01-01

    The purpose of this CRADA was to develop improved glass capillary, x-ray optics for analytical x-ray microbeam applications. X-Ray Optical Systems, Inc. (XOS) designed and fabricated capillary optics and LMES tested those optics for x-ray microanalytical applications using its unique X-Ray Microprobe. Tapered capillaries with 3-microm and 8-microm output openings were fabricated and tested. The tapered capillaries had better spectral quality for x-ray microfluorescence (XRMF) analysis, than non-tapered, straight capillaries that are currently used in the system. X-ray beam count-rates for the tapered capillaries were also greater than the straight capillaries. Two monolithic, polycapillary optics were fabricated and tested. The polycapillary optics produced focal spots of 40 and 100 microm. Beam intensities for the polycapillaries were, respective, 44 and 18 times the intensities found in straight 50-microm and 100-microm capillaries. High-sensitivity scanning will be possible because of the enhanced intensity of the polycapillary optic. LMES and the DP program will benefit from improved capabilities for nondestructive x-ray microanalysis, while XOS will benefit from test results that will enhance the marketability of their products

  19. A correlation of long term effects and radiation quality in the progeny of bystander cells after microbeam radiations: The experimental study of radiotherapy for cancer risk mitigation

    Science.gov (United States)

    Autsavapromporn, N.; Konishi, T.; Liu, C.; Plante, I.; Funayama, T.; Usami, N.; Azzam, EI; Suzuki, M.

    2017-06-01

    The goal of this study is to investigate the role of radiation quality and gap junction intercellular communication (GJIC) in the propagation of delayed stressful effects in the progeny of bystander human skin fibroblasts cultures (NB1RGB). Briefly, confluent NB1RGB cells in the presence and absence of gap junction inhibitor (AGA) were exposed to ionizing radiation (IR) with a different linear energy transfer (LET) either 5.35 keV X rays (LET ∼6 keV/μm) or 18.3 MeV/u carbon (LET ∼103 keV/μm) microbeam radiations. Following 20 populations post-irradiation, the progeny of bystander NB1RGB cells were harvested and assayed for several of biological endpoints. Our results showed that expression of stressful effects in the progeny of bystander cells is dependent on LET. The progeny of bystander cells exposed to low-LET X rays showed the persistence of oxidative stress and it was correlated with the increased mutant fraction. Such effect were not observed after high-LET carbon ions. Interestingly, inhibition of GJIC mitigated the toxic effects in the progeny of bystander cells. Together, the results contribute to the understanding of the fundamental radiation biology relating to the high-LET carbon ions to mitigate cancer risk after radiotherapy. Furthermore, GJIC be considered as a critical mediator in the bystander mutagenic effect.

  20. Terahertz superconducting plasmonic hole array

    OpenAIRE

    Tian, Zhen; Singh, Ranjan; Han, Jiaguang; Gu, Jianqiang; Xing, Qirong; Zhang, Weili

    2010-01-01

    We demonstrate thermally tunable superconductor hole array with active control over their resonant transmission induced by surface plasmon polaritons . The array was lithographically fabricated on high temperature YBCO superconductor and characterized by terahertz-time domain spectroscopy. We observe a clear transition from the virtual excitation of the surface plasmon mode to the real surface plasmon mode. The highly tunable superconducting plasmonic hole arrays may have promising applicatio...

  1. Combinatorial aspects of covering arrays

    Directory of Open Access Journals (Sweden)

    Charles J. Colbourn

    2004-11-01

    Full Text Available Covering arrays generalize orthogonal arrays by requiring that t -tuples be covered, but not requiring that the appearance of t -tuples be balanced.Their uses in screening experiments has found application in software testing, hardware testing, and a variety of fields in which interactions among factors are to be identified. Here a combinatorial view of covering arrays is adopted, encompassing basic bounds, direct constructions, recursive constructions, algorithmic methods, and applications.

  2. Efficient array design for sonotherapy

    International Nuclear Information System (INIS)

    Stephens, Douglas N; Kruse, Dustin E; Ferrara, Katherine W; Ergun, Arif S; Barnes, Stephen; Lu, X Ming

    2008-01-01

    New linear multi-row, multi-frequency arrays have been designed, constructed and tested as fully operational ultrasound probes to produce confocal imaging and therapeutic acoustic intensities with a standard commercial ultrasound imaging system. The triple-array probes and imaging system produce high quality B-mode images with a center row imaging array at 5.3 MHz and sufficient acoustic power with dual therapeutic arrays to produce mild hyperthermia at 1.54 MHz. The therapeutic array pair in the first probe design (termed G3) utilizes a high bandwidth and peak pressure, suitable for mechanical therapies. The second multi-array design (termed G4) has a redesigned therapeutic array pair which is optimized for a high time-averaged power output suitable for mild hyperthermia applications. The 'thermal therapy' design produces more than 4 W of acoustic power from the low-frequency arrays with only a 10.5 deg. C internal rise in temperature after 100 s of continuous use with an unmodified conventional imaging system or substantially longer operation at lower acoustic power. The low-frequency arrays in both probe designs were examined and contrasted for real power transfer efficiency with a KLM model which includes all lossy contributions in the power delivery path from system transmitters to the tissue load. Laboratory verification was successfully performed for the KLM-derived estimates of transducer parallel model acoustic resistance and dissipation resistance, which are the critical design factors for acoustic power output and undesired internal heating, respectively

  3. Compact dynamic microfluidic iris array

    Science.gov (United States)

    Kimmle, Christina; Doering, Christoph; Steuer, Anna; Fouckhardt, Henning

    2011-09-01

    A dynamic microfluidic iris is realized. Light attenuation is achieved by absorption of an opaque liquid (e.g. black ink). The adjustment of the iris diameter is achieved by fluid displacement via a transparent elastomer (silicone) half-sphere. This silicone calotte is hydraulically pressed against a polymethylmethacrylate (PMMA) substrate as the bottom window, such that the opaque liquid is squeezed away, this way opening the iris. With this approach a dynamic range of more than 60 dB can be achieved with response times in the ms to s regime. The design allows the realization of a single iris as well as an iris array. So far the master for the molded silicone structure was fabricated by precision mechanics. The aperture diameter was changed continuously from 0 to 8 mm for a single iris and 0 to 4 mm in case of a 3 x 3 iris array. Moreover, an iris array was combined with a PMMA lens array into a compact module, the distance of both arrays equaling the focal length of the lenses. This way e.g. spatial frequency filter arrays can be realized. The possibility to extend the iris array concept to an array with many elements is demonstrated. Such arrays could be applied e.g. in light-field cameras.

  4. Nanoelectrode array for electrochemical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yelton, William G [Sandia Park, NM; Siegal, Michael P [Albuquerque, NM

    2009-12-01

    A nanoelectrode array comprises a plurality of nanoelectrodes wherein the geometric dimensions of the electrode controls the electrochemical response, and the current density is independent of time. By combining a massive array of nanoelectrodes in parallel, the current signal can be amplified while still retaining the beneficial geometric advantages of nanoelectrodes. Such nanoelectrode arrays can be used in a sensor system for rapid, non-contaminating field analysis. For example, an array of suitably functionalized nanoelectrodes can be incorporated into a small, integrated sensor system that can identify many species rapidly and simultaneously under field conditions in high-resistivity water, without the need for chemical addition to increase conductivity.

  5. Printed glycan array

    DEFF Research Database (Denmark)

    Shilova, Nadezhda; Navakouski, Maxim; Khasbiullina, Nailya

    2012-01-01

    Using printed glycan array (PGA) we compared the results of antibody profiling in undiluted, moderately (1:15) and highly (1:100) diluted human blood serum. Undiluted serum is suitable for studying blood as a tissue in its native state, whereas to study the serum of newborns or small animals one...... usually has to dilute the starting material in order to have sufficient volume for PGA experimentation. The PGA used in this study allows for the use of whole serum without modifications to the protocol, and the background is surprisingly low. Antibodies profiles observed in undiluted serum versus 1......:15 dilution were similar, with only a limited number of new signals identified in the undiluted serum. However, unexpected irregularities were found when IgG and IgM are measured separately, namely, at a 1:15 dilution more intensive IgG signals for many glycans are observed. We believe that in conditions...

  6. Scintillator detector array

    International Nuclear Information System (INIS)

    Cusano, D.A.; Dibianca, F.A.

    1981-01-01

    This patent application relates to a scintillator detector array for use in computerized tomography and comprises a housing including a plurality of chambers, the said housing having a front wall transmissive to x-rays and side walls opaque to x-rays, such as of tungsten and tantalum, a liquid scintillation medium including a soluble fluor, the solvent for the fluor being disposed in the chambers. The solvent comprises either an intrinsically high Z solvent or a solvent which has dissolved therein a high Z compound e.g. iodo or bromonaphthalene; or toluene, xylene or trimethylbenzene with a lead or tin alkyl dissolved therein. Also disposed about the chambers are a plurality of photoelectric devices. (author)

  7. Cascading Constrained 2-D Arrays using Periodic Merging Arrays

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Laursen, Torben Vaarby

    2003-01-01

    We consider a method for designing 2-D constrained codes by cascading finite width arrays using predefined finite width periodic merging arrays. This provides a constructive lower bound on the capacity of the 2-D constrained code. Examples include symmetric RLL and density constrained codes...

  8. The OncoArray Consortium

    DEFF Research Database (Denmark)

    Amos, Christopher I; Dennis, Joe; Wang, Zhaoming

    2017-01-01

    BACKGROUND: Common cancers develop through a multistep process often including inherited susceptibility. Collaboration among multiple institutions, and funding from multiple sources, has allowed the development of an inexpensive genotyping microarray, the OncoArray. The array includes a genome-wi...

  9. Submillimeter heterodyne arrays for APEX

    NARCIS (Netherlands)

    Güsten, R.; Baryshev, A.; Bell, A.; Belloche, A.; Graf, U.; Hafok, H.; Heyminck, S.; Hochgürtel, S.; Honingh, C. E.; Jacobs, K.; Kasemann, C.; Klein, B.; Klein, T.; Korn, A.; Krämer, I.; Leinz, C.; Lundgren, A.; Menten, K. M.; Meyer, K.; Muders, D.; Pacek, F.; Rabanus, D.; Schäfer, F.; Schilke, P.; Schneider, G.; Stutzki, J.; Wieching, G.; Wunsch, A.; Wyrowski, F.

    2008-01-01

    We report on developments of submillimeter heterodyne arrays for high resolution spectroscopy with APEX. Shortly, we will operate state-of-the-art instruments in all major atmospheric windows accessible from Llano de Chajnantor. CHAMP+, a dual-color 2×7 element heterodyne array for operation in the

  10. Digital electrostatic acoustic transducer array

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-12-19

    In this paper we present the fabrication and characterization of an array of electrostatic acoustic transducers. The array is micromachined on a silicon wafer using standard micro-machining techniques. Each array contains 2n electrostatic transducer membranes, where “n” is the bit number. Every element of the array has a hexagonal membrane shape structure, which is separated from the substrate by 3µm air gap. The membrane is made out 5µm thick polyimide layer that has a bottom gold electrode on the substrate and a gold top electrode on top of the membrane (250nm). The wafer layout design was diced in nine chips with different array configurations, with variation of the membrane dimensions. The device was tested with 90 V giving and sound output level as high as 35dB, while actuating all the elements at the same time.

  11. Chunking of Large Multidimensional Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Rotem, Doron; Otoo, Ekow J.; Seshadri, Sridhar

    2007-02-28

    Data intensive scientific computations as well on-lineanalytical processing applications as are done on very large datasetsthat are modeled as k-dimensional arrays. The storage organization ofsuch arrays on disks is done by partitioning the large global array intofixed size hyper-rectangular sub-arrays called chunks or tiles that formthe units of data transfer between disk and memory. Typical queriesinvolve the retrieval of sub-arrays in a manner that accesses all chunksthat overlap the query results. An important metric of the storageefficiency is the expected number of chunks retrieved over all suchqueries. The question that immediately arises is "what shapes of arraychunks give the minimum expected number of chunks over a query workload?"In this paper we develop two probabilistic mathematical models of theproblem and provide exact solutions using steepest descent and geometricprogramming methods. Experimental results, using synthetic workloads onreal life data sets, show that our chunking is much more efficient thanthe existing approximate solutions.

  12. Planning a Global Array of Broadband Seismic Arrays

    Science.gov (United States)

    Koper, Keith D.; Ammon, Charles J.

    2013-08-01

    A diverse group of more than 70 seismologists met for 2 days in Raleigh, N.C., to report on recent innovations in seismic array methods and to discuss the future of seismic arrays in global seismology. The workshop was sponsored by the Incorporated Research Institutions for Seismology (IRIS), with U.S. National Science Foundation funding. Participants included representatives of existing array research groups in Australia, Canada, Germany, Japan, Norway, and the United States, with individuals from academia, government, and industry. The workshop was organized by the authors of this meeting report, Pablo Ampeuro (California Institute of Technology), and Colleen Dalton (Boston University), along with IRIS staff support.

  13. Dependently typed array programs don't go wrong

    NARCIS (Netherlands)

    Trojahner, K.; Grelck, C.

    2008-01-01

    The array programming paradigm adopts multidimensional arrays as the fundamental data structures of computation. Array operations process entire arrays instead of just single elements. This makes array programs highly expressive and introduces data parallelism in a natural way. Array programming

  14. Dependently typed array programs don’t go wrong

    NARCIS (Netherlands)

    Trojahner, K.; Grelck, C.

    2009-01-01

    The array programming paradigm adopts multidimensional arrays as the fundamental data structures of computation. Array operations process entire arrays instead of just single elements. This makes array programs highly expressive and introduces data parallelism in a natural way. Array programming

  15. Vacancy-related defects in n-type Si implanted with a rarefied microbeam of accelerated heavy ions in the MeV range

    Energy Technology Data Exchange (ETDEWEB)

    Capan, I. [Rudjer Boskovic Institute, Bijenička 54, 10000 Zagreb (Croatia); Pastuović, Ž., E-mail: zkp@ansto.gov.au [Center for Accelerator Science, ANSTO, Locked bag 2001, Kirrawee Dc, NSW 2232 (Australia); Siegele, R. [Center for Accelerator Science, ANSTO, Locked bag 2001, Kirrawee Dc, NSW 2232 (Australia); Jaćimović, R. [Jozef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana (Slovenia)

    2016-04-01

    Deep level transient spectroscopy (DLTS) has been used to study vacancy-related defects formed in bulk n-type Czochralski-grown silicon after implantation of accelerated heavy ions: 6.5 MeV O, 10.5 MeV Si, 10.5 MeV Ge, and 11 MeV Er in the single ion regime with fluences from 10{sup 9} cm{sup −2} to 10{sup 10} cm{sup −2} and a direct comparison made with defects formed in the same material irradiated with 0.7 MeV fast neutron fluences up to 10{sup 12} cm{sup −2}. A scanning ion microprobe was used as the ion implantation tool of n-Cz:Si samples prepared as Schottky diodes, while the ion beam induced current (IBIC) technique was utilized for direct ion counting. The single acceptor state of the divacancy V{sub 2}(−/0) is the most prominent defect state observed in DLTS spectra of n-CZ:Si samples implanted by selected ions and the sample irradiated by neutrons. The complete suppression of the DLTS signal related to the double acceptor state of divacancy, V{sub 2}(=/−) has been observed in all samples irradiated by ions and neutrons. Moreover, the DLTS peak associated with formation of the vacancy-oxygen complex VO in the neutron irradiated sample was also completely suppressed in DLTS spectra of samples implanted with the raster scanned ion microbeam. The reason for such behaviour is twofold, (i) the local depletion of the carrier concentration in the highly disordered regions, and (ii) the effect of the microprobe-assisted single ion implantation. The activation energy for electron emission for states assigned to the V{sub 2}(−/0) defect formed in samples implanted by single ions follows the Meyer–Neldel rule. An increase of the activation energy is strongly correlated with increasing ion mass.

  16. ESPRIT And Uniform Linear Arrays

    Science.gov (United States)

    Roy, R. H.; Goldburg, M.; Ottersten, B. E.; Swindlehurst, A. L.; Viberg, M.; Kailath, T.

    1989-11-01

    Abstract ¬â€?ESPRIT is a recently developed and patented technique for high-resolution estimation of signal parameters. It exploits an invariance structure designed into the sensor array to achieve a reduction in computational requirements of many orders of magnitude over previous techniques such as MUSIC, Burg's MEM, and Capon's ML, and in addition achieves performance improvement as measured by parameter estimate error variance. It is also manifestly more robust with respect to sensor errors (e.g. gain, phase, and location errors) than other methods as well. Whereas ESPRIT only requires that the sensor array possess a single invariance best visualized by considering two identical but other-wise arbitrary arrays of sensors displaced (but not rotated) with respect to each other, many arrays currently in use in various applications are uniform linear arrays of identical sensor elements. Phased array radars are commonplace in high-resolution direction finding systems, and uniform tapped delay lines (i.e., constant rate A/D converters) are the rule rather than the exception in digital signal processing systems. Such arrays possess many invariances, and are amenable to other types of analysis, which is one of the main reasons such structures are so prevalent. Recent developments in high-resolution algorithms of the signal/noise subspace genre including total least squares (TLS) ESPRIT applied to uniform linear arrays are summarized. ESPRIT is also shown to be a generalization of the root-MUSIC algorithm (applicable only to the case of uniform linear arrays of omni-directional sensors and unimodular cisoids). Comparisons with various estimator bounds, including CramerRao bounds, are presented.

  17. Replica amplification of nucleic acid arrays

    Science.gov (United States)

    Church, George M.; Mitra, Robi D.

    2010-08-31

    Disclosed are improved methods of making and using immobilized arrays of nucleic acids, particularly methods for producing replicas of such arrays. Included are methods for producing high density arrays of nucleic acids and replicas of such arrays, as well as methods for preserving the resolution of arrays through rounds of replication. Also included are methods which take advantage of the availability of replicas of arrays for increased sensitivity in detection of sequences on arrays. Improved methods of sequencing nucleic acids immobilized on arrays utilizing single copies of arrays and methods taking further advantage of the availability of replicas of arrays are disclosed. The improvements lead to higher fidelity and longer read lengths of sequences immobilized on arrays. Methods are also disclosed which improve the efficiency of multiplex PCR using arrays of immobilized nucleic acids.

  18. Fundamentals of ultrasonic phased arrays

    CERN Document Server

    Schmerr, Lester W

    2014-01-01

    This book describes in detail the physical and mathematical foundations of ultrasonic phased array measurements.?The book uses linear systems theory to develop a comprehensive model of the signals and images that can be formed with phased arrays. Engineers working in the field of ultrasonic nondestructive evaluation (NDE) will find in this approach a wealth of information on how to design, optimize and interpret ultrasonic inspections with phased arrays. The fundamentals and models described in the book will also be of significant interest to other fields, including the medical ultrasound and

  19. Antenna arrays a computational approach

    CERN Document Server

    Haupt, Randy L

    2010-01-01

    This book covers a wide range of antenna array topics that are becoming increasingly important in wireless applications, particularly in design and computer modeling. Signal processing and numerical modeling algorithms are explored, and MATLAB computer codes are provided for many of the design examples. Pictures of antenna arrays and components provided by industry and government sources are presented with explanations of how they work. Antenna Arrays is a valuable reference for practicing engineers and scientists in wireless communications, radar, and remote sensing, and an excellent textbook for advanced antenna courses.

  20. Interferometric optical vortex array generator.

    Science.gov (United States)

    Vyas, Sunil; Senthilkumaran, P

    2007-05-20

    Two new interferometric configurations for optical vortex array generation are presented. These interferometers are different from the conventional interferometers in that they are capable of producing a large number of isolated zeros of intensity, and all of them contain optical vortices. Simulation and theory for optical vortex array generation using three-plane-wave interference is presented. The vortex dipole array produced this way is noninteracting, as there are no attraction or repulsion forces between them, leading to annihilation or creation of vortex pairs.

  1. On the Mesh Array for Matrix Multiplication

    OpenAIRE

    Kak, Subhash

    2010-01-01

    This article presents new properties of the mesh array for matrix multiplication. In contrast to the standard array that requires 3n-2 steps to complete its computation, the mesh array requires only 2n-1 steps. Symmetries of the mesh array computed values are presented which enhance the efficiency of the array for specific applications. In multiplying symmetric matrices, the results are obtained in 3n/2+1 steps. The mesh array is examined for its application as a scrambling system.

  2. Next Generation Microshutter Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop the next generation MicroShutter Array (MSA) as a multi-object field selector for missions anticipated in the next two decades. For many...

  3. Fundamentals of spherical array processing

    CERN Document Server

    Rafaely, Boaz

    2015-01-01

    This book provides a comprehensive introduction to the theory and practice of spherical microphone arrays. It is written for graduate students, researchers and engineers who work with spherical microphone arrays in a wide range of applications.   The first two chapters provide the reader with the necessary mathematical and physical background, including an introduction to the spherical Fourier transform and the formulation of plane-wave sound fields in the spherical harmonic domain. The third chapter covers the theory of spatial sampling, employed when selecting the positions of microphones to sample sound pressure functions in space. Subsequent chapters present various spherical array configurations, including the popular rigid-sphere-based configuration. Beamforming (spatial filtering) in the spherical harmonics domain, including axis-symmetric beamforming, and the performance measures of directivity index and white noise gain are introduced, and a range of optimal beamformers for spherical arrays, includi...

  4. Thermopile Area Array Readout Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA/JPL thermopile detector linear arrays, wire bonded to Black Forest Engineering (BFE) CMOS readout integrated circuits (ROICs), have been utilized in NASA...

  5. The Applicability of Incoherent Array Processing to IMS Seismic Arrays

    Science.gov (United States)

    Gibbons, Steven J.

    2014-03-01

    The seismic arrays of the International Monitoring System (IMS) for the Comprehensive Nuclear-Test-Ban Treaty (CTBT) are highly diverse in size and configuration, with apertures ranging from under 1 km to over 60 km. Large and medium aperture arrays with large inter-site spacings complicate the detection and estimation of high-frequency phases lacking coherence between sensors. Pipeline detection algorithms often miss such phases, since they only consider frequencies low enough to allow coherent array processing, and phases that are detected are often attributed qualitatively incorrect backazimuth and slowness estimates. This can result in missed events, due to either a lack of contributing phases or by corruption of event hypotheses by spurious detections. It has been demonstrated previously that continuous spectral estimation can both detect and estimate phases on the largest aperture arrays, with arrivals identified as local maxima on beams of transformed spectrograms. The estimation procedure in effect measures group velocity rather than phase velocity, as is the case for classical f-k analysis, and the ability to estimate slowness vectors requires sufficiently large inter-sensor distances to resolve time-delays between pulses with a period of the order 4-5 s. Spectrogram beampacking works well on five IMS arrays with apertures over 20 km (NOA, AKASG, YKA, WRA, and KURK) without additional post-processing. Seven arrays with 10-20 km aperture (MJAR, ESDC, ILAR, KSRS, CMAR, ASAR, and EKA) can provide robust parameter estimates subject to a smoothing of the resulting slowness grids, most effectively achieved by convolving the measured slowness grids with the array response function for a 4 or 5 s period signal. Even for medium aperture arrays which can provide high-quality coherent slowness estimates, a complementary spectrogram beampacking procedure could act as a quality control by providing non-aliased estimates when the coherent slowness grids display

  6. Flexible eddy current coil arrays

    International Nuclear Information System (INIS)

    Krampfner, Y.; Johnson, D.P.

    1987-01-01

    A novel approach was devised to overcome certain limitations of conventional eddy current testing. The typical single-element hand-wound probe was replaced with a two dimensional array of spirally wound probe elements deposited on a thin, flexible polyimide substrate. This provides full and reliable coverage of the test area and eliminates the need for scanning. The flexible substrate construction of the array allows the probes to conform to irregular part geometries, such as turbine blades and tubing, thereby eliminating the need for specialized probes for each geometry. Additionally, the batch manufacturing process of the array can yield highly uniform and reproducible coil geometries. The array is driven by a portable computer-based eddy current instrument, smartEDDY/sup TM/, capable of two-frequency operation, and offers a great deal of versatility and flexibility due to its software-based architecture. The array is coupled to the instrument via an 80-switch multiplexer that can be configured to address up to 1600 probes. The individual array elements may be addressed in any desired sequence, as defined by the software

  7. Calibration of a microprobe array

    International Nuclear Information System (INIS)

    Schrader, Christian; Tutsch, Rainer

    2012-01-01

    Conventional coordinate measurement machines are not well adapted to the specific needs for the measurement of mechanical microstructures that are made in a highly parallel production process. In particular, the increase of the measurement speed is addressed by using an array of microprobes to measure a number of objects in parallel. It consists of multiple microprobes that are etched into the same silicon substrate. The styli are glued onto a boss structure in the middle of a silicon membrane. To facilitate the alignment of an array and the underlying wafer, the array is mounted on three stacked rotational stages. Due to the production tolerances, the positions of the touching balls of the probes relative to their pivot have to be calibrated. The probe sensitivity is another field of calibration. This paper describes an efficient calibration procedure of the probe array which is usable for arrays with a large number of probes and different array layouts. The validation method of this procedure is explained and calibration results are discussed (paper)

  8. Integrated residential photovoltaic array development

    Science.gov (United States)

    Royal, G. C., III

    1981-04-01

    Sixteen conceptual designs of residential photovoltaic arrays are described. Each design concept was evaluated by an industry advisory panel using a comprehensive set of technical, economic and institutional criteria. Key electrical and mechanical concerns that effect further array subsystem development are also discussed. Three integrated array design concepts were selected by the advisory panel for further optimization and development. From these concepts a single one will be selected for detailed analysis and prototype fabrication. The three concepts selected are: (1) An array of frameless panels/modules sealed in a T shaped zipper locking neoprene gasket grid pressure fitted into an extruded aluminum channel grid fastened across the rafters. (2) An array of frameless modules pressure fitted in a series of zipper locking EPDM rubber extrusions adhesively bonded to the roof. Series string voltage is developed using a set of integral tongue connectors and positioning blocks. (3) An array of frameless modules sealed by a silicone adhesive in a prefabricated grid of rigid tape and sheet metal attached to the roof.

  9. CCD and IR array controllers

    Science.gov (United States)

    Leach, Robert W.; Low, Frank J.

    2000-08-01

    A family of controllers has bene developed that is powerful and flexible enough to operate a wide range of CCD and IR focal plane arrays in a variety of ground-based applications. These include fast readout of small CCD and IR arrays for adaptive optics applications, slow readout of large CCD and IR mosaics, and single CCD and IR array operation at low background/low noise regimes as well as high background/high speed regimes. The CCD and IR controllers have a common digital core based on user- programmable digital signal processors that are used to generate the array clocking and signal processing signals customized for each application. A fiber optic link passes image data and commands to VME or PCI interface boards resident in a host computer to the controller. CCD signal processing is done with a dual slope integrator operating at speeds of up to one Megapixel per second per channel. Signal processing of IR arrays is done either with a dual channel video processor or a four channel video processor that has built-in image memory and a coadder to 32-bit precision for operating high background arrays. Recent developments underway include the implementation of a fast fiber optic data link operating at a speed of 12.5 Megapixels per second for fast image transfer from the controller to the host computer, and supporting image acquisition software and device drivers for the PCI interface board for the Sun Solaris, Linux and Windows 2000 operating systems.

  10. Coded aperture imaging with uniformly redundant arrays

    International Nuclear Information System (INIS)

    Fenimore, E.E.; Cannon, T.M.

    1980-01-01

    A system is described which uses uniformly redundant arrays to image non-focusable radiation. The array is used in conjunction with a balanced correlation technique to provide a system with no artifacts so that virtually limitless signal-to-noise ratio is obtained with high transmission characteristics. The array is mosaicked to reduce required detector size over conventional array detectors. 15 claims

  11. Enhanced DNA double-strand break repair of microbeam targeted A549 lung carcinoma cells by adjacent WI38 normal lung fibroblast cells via bi-directional signaling.

    Science.gov (United States)

    Kobayashi, Alisa; Tengku Ahmad, Tengku Ahbrizal Farizal; Autsavapromporn, Narongchai; Oikawa, Masakazu; Homma-Takeda, Shino; Furusawa, Yoshiya; Wang, Jun; Konishi, Teruaki

    2017-10-01

    Understanding the mechanisms underlying the radiation-induced bystander effect (RIBE) and bi-directional signaling between irradiated carcinoma cells and their surrounding non-irradiated normal cells is relevant to cancer radiotherapy. The present study investigated propagation of RIBE signals between human lung carcinoma A549 cells and normal lung fibroblast WI38 cells in bystander cells, either directly or indirectly contacting irradiated A549 cells. We prepared A549-GFP/WI38 co-cultures and A549-GFP/A549 co-cultures, in which A549-GFP cells stably expressing H2BGFP were co-cultured with either A549 cells or WI38 cells, respectively. Using the SPICE-NIRS microbeam, only the A549-GFP cells were irradiated with 500 protons per cell. The level of γ-H2AX, a marker for DNA double-strand breaks (DSB), was subsequently measured for up to 24h post-irradiation in three categories of cells: (1) "targeted"/irradiated A549-GFP cells; (2) "neighboring"/non-irradiated cells directly contacting the "targeted" cells; and (3) "distant"/non-irradiated cells, which were not in direct contact with the "targeted" cells. We found that DSB repair in targeted A549-GFP cells was enhanced by co-cultured WI38 cells. The bystander response in A549-GFP/A549 cell co-cultures, as marked by γ-H2AX levels at 8h post-irradiation, showed a decrease to non-irradiated control level when approaching 24h, while the neighboring/distant bystander WI38 cells in A549-GFP/WI38 co-cultures was maintained at a similar level until 24h post-irradiation. Surprisingly, distant A549-GFP cells in A549-GFP/WI38 co-cultures showed time dependency similar to bystander WI38 cells, but not to distant cells in A549-GFP/A549 co-cultures. These observations indicate that γ-H2AX was induced in WI38 cells as a result of RIBE. WI38 cells were not only involved in rescue of targeted A549, but also in the modification of RIBE against distant A549-GFP cells. The present results demonstrate that radiation-induced bi

  12. Retrieval of Mir Solar Array

    Science.gov (United States)

    Rutledge, Sharon K.; deGroh, Kim K.

    1999-01-01

    A Russian solar array panel removed in November 1997 from the non-articulating photovoltaic array on the Mir core module was returned to Earth on STS-89 in January 1998. The panel had been exposed to low Earth orbit (LEO) for 10 years prior to retrieval. The retrieval provided a unique opportunity to study the effects of the LEO environment on a functional solar array. To take advantage of this opportunity, a team composed of members from RSC-Energia (Russia), the Boeing Company, and the following NASA Centers--Johnson Space Center, Kennedy Space Center, Langley Research Center, Marshall Space Flight Center, and Lewis Research Center--was put together to analyze the array. After post-retrieval inspections at the Spacehab Facility at Kennedy in Florida, the array was shipped to Lewis in Cleveland for electrical performance tests, closeup photodocumentation, and removal of selected solar cells and blanket material. With approval from RSC-Energia, five cell pairs and their accompanying blanket and mesh material, and samples of painted handrail materials were selected for removal on the basis of their ability to provide degradation information. Sites were selected that provided different sizes and shapes of micrometeoroid impacts and different levels of surface contamination. These materials were then distributed among the team for round robin testing.

  13. X-ray detector array

    International Nuclear Information System (INIS)

    Houston, J.M.

    1980-01-01

    The object of the invention (an ionization chamber X-ray detector array for use with high speed computerised tomographic imaging apparatus) is to reduce the time required to produce a tomographic image. The detector array described determines the distribution of X-ray intensities in one or more flat, coplanar X-ray beams. It comprises three flat anode sheets parallel to the X-ray beam, a plurality of rod-like cathodes between the anodes, a detector gas between the electrodes and a means for applying a potential between the electrodes. Each of the X-ray sources is collimated to give a narrow, planar section of X-ray photons. Sets of X-ray sources in the array are pulsed simultaneously to obtain X-ray transmission data for tomographic image reconstruction. (U.K.)

  14. Innovations in IR projector arrays

    Science.gov (United States)

    Cole, Barry E.; Higashi, B.; Ridley, Jeff A.; Holmen, J.; Newstrom, K.; Zins, C.; Nguyen, K.; Weeres, Steven R.; Johnson, Burgess R.; Stockbridge, Robert G.; Murrer, Robert Lee; Olson, Eric M.; Bergin, Thomas P.; Kircher, James R.; Flynn, David S.

    2000-07-01

    In the past year, Honeywell has developed a 512 X 512 snapshot scene projector containing pixels with very high radiance efficiency. The array can operate in both snapshot and raster mode. The array pixels have near black body characteristics, high radiance outputs, broad band performance, and high speed. IR measurements and performance of these pixels will be described. In addition, a vacuum probe station that makes it possible to select the best die for packaging and delivery based on wafer level radiance screening, has been developed and is in operation. This system, as well as other improvements, will be described. Finally, a review of the status of the present projectors and plans for future arrays is included.

  15. Thin, Flexible IMM Solar Array

    Science.gov (United States)

    Walmsley, Nicholas

    2015-01-01

    NASA needs solar arrays that are thin, flexible, and highly efficient; package compactly for launch; and deploy into large, structurally stable high-power generators. Inverted metamorphic multijunction (IMM) solar cells can enable these arrays, but integration of this thin crystalline cell technology presents certain challenges. The Thin Hybrid Interconnected Solar Array (THINS) technology allows robust and reliable integration of IMM cells into a flexible blanket comprising standardized modules engineered for easy production. The modules support the IMM cell by using multifunctional materials for structural stability, shielding, coefficient of thermal expansion (CTE) stress relief, and integrated thermal and electrical functions. The design approach includes total encapsulation, which benefits high voltage as well as electrostatic performance.

  16. Design Considerations for Array CGH to OligonucleotideArrays

    Energy Technology Data Exchange (ETDEWEB)

    Baldocchi, R.A.; Glynne, R.J.; Chin, K.; Kowbel, D.; Collins, C.; Mack, D.H.; Gray, J.W.

    2005-03-04

    Background: Representational oligonucleotide microarray analysis has been developed for detection of single nucleotide polymorphisms and/or for genome copy number changes. In this process, the intensity of hybridization to oligonucleotides arrays is increased by hybridizing a polymerase chain reaction (PCR)-amplified representation of reduced genomic complexity. However, hybridization to some oligonucleotides is not sufficiently high to allow precise analysis of that portion of the genome. Methods: In an effort to identify aspects of oligonucleotide hybridization affecting signal intensity, we explored the importance of the PCR product strand to which each oligonucleotide is homologous and the sequence of the array oligonucleotides. We accomplished this by hybridizing multiple PCR-amplified products to oligonucleotide arrays carrying two sense and two antisense 50-mer oligonucleotides for each PCR amplicon. Results: In some cases, hybridization intensity depended more strongly on the PCR amplicon strand (i.e., sense vs. antisense) than on the detection oligonucleotide sequence. In other cases, the oligonucleotide sequence seemed to dominate. Conclusion: Oligonucleotide arrays for analysis of DNA copy number or for single nucleotide polymorphism content should be designed to carry probes to sense and antisense strands of each PCR amplicon to ensure sufficient hybridization and signal intensity.

  17. Broadband acoustic phased array with subwavelength active tube array

    Science.gov (United States)

    Li, Xiao-Yan; Yang, Zhang-Zhao; Zhu, Yi-Fan; Zou, Xin-Ye; Cheng, Jian-Chun

    2018-02-01

    Acoustic metasurfaces provide a way to manipulate wavefronts at anomalous reflection or refraction angles through subwavelength structures. Here, based on the generalized Snell's refraction law for acoustic metasurfaces and the classical acoustic phased array (PA) theory, a broadband acoustic PA with a subwavelength active tube array has been proposed to form a special acoustic beam and to determine the directivity characteristics of the acoustic source. Theoretical analysis shows that the dispersionless wavefront manipulation can be realized by the gradient model of the active tube array, and a wide working frequency band can be obtained in practical applications from the simulated and experimental results. The numerical results of forming a special acoustic beam and establishing an acoustic focus model with an arbitrary focal position are consistent with the theoretical predictions. The experimental results agree well with the simulated results in the model of forming the acoustic beam of 45 ° . By combining acoustic metamaterials and conventional acoustic PA, the model of the active tube array paves a way to design a composite acoustic PA with high radiation efficiency and system robustness without the need for any complex circuit control system. This design concept is expected to be used in the design of ultrasonic therapy devices and high-efficiency transducers.

  18. Phased arrays: inline flow line hub inspection using phased arrays

    NARCIS (Netherlands)

    Bloom, J.G.P.; Chougrani, K.; Rundberg, H.; Oldenziel, G.; Deleye, X.; Martina, Q.

    2011-01-01

    The feasibility of the inspection of flow line hubs using the phased array technique was investigated to determine the surface area of the seal area degraded by corrosion. A clean model of the hub was simulated to gain insight into the geometrical echoes and to determine the area covered by the

  19. Terahertz superconducting plasmonic hole array.

    Science.gov (United States)

    Tian, Zhen; Singh, Ranjan; Han, Jiaguang; Gu, Jianqiang; Xing, Qirong; Wu, Judy; Zhang, Weili

    2010-11-01

    We demonstrate a superconductor array of subwavelength holes with active thermal control over the resonant transmission induced by surface plasmon polaritons. The array was lithographically fabricated on a high-temperature yttrium barium copper oxide superconductor and characterized by terahertz time-domain spectroscopy. We observe a clear transition from a virtual excitation of the surface plasmon mode to a real surface plasmon mode. The highly controllable superconducting plasmonic crystals may find promising applications in the design of low-loss, large- dynamic-range amplitude modulation and surface-plasmon-based terahertz devices.

  20. Hybrid Arrays for Chemical Sensing

    Science.gov (United States)

    Kramer, Kirsten E.; Rose-Pehrsson, Susan L.; Johnson, Kevin J.; Minor, Christian P.

    In recent years, multisensory approaches to environment monitoring for chemical detection as well as other forms of situational awareness have become increasingly popular. A hybrid sensor is a multimodal system that incorporates several sensing elements and thus produces data that are multivariate in nature and may be significantly increased in complexity compared to data provided by single-sensor systems. Though a hybrid sensor is itself an array, hybrid sensors are often organized into more complex sensing systems through an assortment of network topologies. Part of the reason for the shift to hybrid sensors is due to advancements in sensor technology and computational power available for processing larger amounts of data. There is also ample evidence to support the claim that a multivariate analytical approach is generally superior to univariate measurements because it provides additional redundant and complementary information (Hall, D. L.; Linas, J., Eds., Handbook of Multisensor Data Fusion, CRC, Boca Raton, FL, 2001). However, the benefits of a multisensory approach are not automatically achieved. Interpretation of data from hybrid arrays of sensors requires the analyst to develop an application-specific methodology to optimally fuse the disparate sources of data generated by the hybrid array into useful information characterizing the sample or environment being observed. Consequently, multivariate data analysis techniques such as those employed in the field of chemometrics have become more important in analyzing sensor array data. Depending on the nature of the acquired data, a number of chemometric algorithms may prove useful in the analysis and interpretation of data from hybrid sensor arrays. It is important to note, however, that the challenges posed by the analysis of hybrid sensor array data are not unique to the field of chemical sensing. Applications in electrical and process engineering, remote sensing, medicine, and of course, artificial

  1. Large scale biomimetic membrane arrays

    DEFF Research Database (Denmark)

    Hansen, Jesper Søndergaard; Perry, Mark; Vogel, Jörg

    2009-01-01

    To establish planar biomimetic membranes across large scale partition aperture arrays, we created a disposable single-use horizontal chamber design that supports combined optical-electrical measurements. Functional lipid bilayers could easily and efficiently be established across CO2 laser micro...... peptides and proteins. Next, we tested the scalability of the biomimetic membrane design by establishing lipid bilayers in rectangular 24 x 24 and hexagonal 24 x 27 aperture arrays, respectively. The results presented show that the design is suitable for further developments of sensitive biosensor assays...

  2. Multiwall carbon nanotube microcavity arrays

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Rajib; Butt, Haider, E-mail: h.butt@bham.ac.uk [Nanotechnology Laboratory, School of Mechanical Engineering, University of Birmingham, Birmingham B15 2TT (United Kingdom); Rifat, Ahmmed A. [Integrated Lightwave Research Group, Department of Electrical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603 (Malaysia); Yetisen, Ali K.; Yun, Seok Hyun [Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Landsdowne Street, Cambridge, Massachusetts 02139 (United States); Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Dai, Qing [National Center for Nanoscience and Technology, Beijing 100190 (China)

    2016-03-21

    Periodic highly dense multi-wall carbon nanotube (MWCNT) arrays can act as photonic materials exhibiting band gaps in the visible regime and beyond terahertz range. MWCNT arrays in square arrangement for nanoscale lattice constants can be configured as a microcavity with predictable resonance frequencies. Here, computational analyses of compact square microcavities (≈0.8 × 0.8 μm{sup 2}) in MWCNT arrays were demonstrated to obtain enhanced quality factors (≈170–180) and narrow-band resonance peaks. Cavity resonances were rationally designed and optimized (nanotube geometry and cavity size) with finite element method. Series (1 × 2 and 1 × 3) and parallel (2 × 1 and 3 × 1) combinations of microcavities were modeled and resonance modes were analyzed. Higher order MWCNT microcavities showed enhanced resonance modes, which were red shifted with increasing Q-factors. Parallel microcavity geometries were also optimized to obtain narrow-band tunable filtering in low-loss communication windows (810, 1336, and 1558 nm). Compact series and parallel MWCNT microcavity arrays may have applications in optical filters and miniaturized optical communication devices.

  3. Gamma-ray array physics

    International Nuclear Information System (INIS)

    Lister, C. J.

    1999-01-01

    In this contribution I am going to discuss the development of large arrays of Compton Suppressed, High Purity Germanium (HpGe) detectors and the physics that has been, that is being, and that will be done with them. These arrays and their science have dominated low-energy nuclear structure research for the last twenty years and will continue to do so in the foreseeable future. John Sharpey Schafer played a visionary role in convincing a skeptical world that the development of these arrays would lead to a path of enlightenment. The extent to which he succeeded can be seen both through the world-wide propagation of ever more sophisticated devices, and through the world-wide propagation of his students. I, personally, would not be working in research if it were not for Johns inspirational leadership. I am eternally grateful to him. Many excellent reviews of array physics have been made in the past which can provide detailed background reading. The review by Paul Nolan, another ex-Sharpey Schafer student, is particularly comprehensive and clear

  4. Photoelectrochemistry of Semiconductor Nanowire Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Mallouk, Thomas E; Redwing, Joan M

    2009-11-10

    This project supported research on the growth and photoelectrochemical characterization of semiconductor nanowire arrays, and on the development of catalytic materials for visible light water splitting to produce hydrogen and oxygen. Silicon nanowires were grown in the pores of anodic aluminum oxide films by the vapor-liquid-solid technique and were characterized electrochemically. Because adventitious doping from the membrane led to high dark currents, silicon nanowire arrays were then grown on silicon substrates. The dependence of the dark current and photovoltage on preparation techniques, wire diameter, and defect density was studied for both p-silicon and p-indium phosphide nanowire arrays. The open circuit photovoltage of liquid junction cells increased with increasing wire diameter, reaching 350 mV for micron-diameter silicon wires. Liquid junction and radial p-n junction solar cells were fabricated from silicon nano- and microwire arrays and tested. Iridium oxide cluster catalysts stabilized by bidentate malonate and succinate ligands were also made and studied for the water oxidation reaction. Highlights of this project included the first papers on silicon and indium phosphide nanowire solar cells, and a new procedure for making ligand-stabilized water oxidation catalysts that can be covalently linked to molecular photosensitizers or electrode surfaces.

  5. Micromolding for ceramic microneedle arrays

    NARCIS (Netherlands)

    van Nieuwkasteele-Bystrova, Svetlana Nikolajevna; Lüttge, Regina

    2011-01-01

    The fabrication process of ceramic microneedle arrays (MNAs) is presented. This includes the manufacturing of an SU-8/Si-master, its double replication resulting in a PDMS mold for production by micromolding and ceramic sintering. The robustness of the replicated structures was tested by means of

  6. LOFAR- The Low Frequency Array

    NARCIS (Netherlands)

    Falcke, H.D.E.

    2006-01-01

    LOFAR is an innovative radio telescope in the frequency range of 10-240 MHz, realized as a phased array. It will become the largest radio telescope in the world in the time frame 2006-2010, located in Northern Europe. LOFAR is being implemented as a Wide Area Sensor Network which connects thousands

  7. Array Technology for Terahertz Imaging

    Science.gov (United States)

    Reck, Theodore; Siles, Jose; Jung, Cecile; Gill, John; Lee, Choonsup; Chattopadhyay, Goutam; Mehdi, Imran; Cooper, Ken

    2012-01-01

    Heterodyne terahertz (0.3 - 3THz) imaging systems are currently limited to single or a low number of pixels. Drastic improvements in imaging sensitivity and speed can be achieved by replacing single pixel systems with an array of detectors. This paper presents an array topology that is being developed at the Jet Propulsion Laboratory based on the micromachining of silicon. This technique fabricates the array's package and waveguide components by plasma etching of silicon, resulting in devices with precision surpassing that of current metal machining techniques. Using silicon increases the versatility of the packaging, enabling a variety of orientations of circuitry within the device which increases circuit density and design options. The design of a two-pixel transceiver utilizing a stacked architecture is presented that achieves a pixel spacing of 10mm. By only allowing coupling from the top and bottom of the package the design can readily be arrayed in two dimensions with a spacing of 10mm x 18mm.

  8. Light weight digital array SAR

    NARCIS (Netherlands)

    Otten, M.; Maas, N.; Bolt, R.; Anitori, L.

    2010-01-01

    A light weight SAR has been designed, suitable for short range tactical UAVs, consisting of a fully digital receive array, and a very compact active transmit antenna. The weight of the complete RF front is expected to be below 3 kg, with a power consumption below 30 W. This X-band system can provide

  9. Solar array manufacturing industry simulation

    Science.gov (United States)

    Chamberlain, R. G.; Firnett, P. J.; Kleine, B.

    1980-01-01

    Solar Array Manufacturing Industry Simulation (SAMIS) program is a standardized model of industry to manufacture silicon solar modules for use in electricity generation. Model is used to develop financial reports that detail requirements, including amounts and prices for materials, labor, facilities, and equipment required by companies.

  10. Directivity of basic linear arrays

    DEFF Research Database (Denmark)

    Bach, Henning

    1970-01-01

    For a linear uniform array ofnelements, an expression is derived for the directivity as a function of the spacing and the phase constants. The cases of isotropic elements, collinear short dipoles, and parallel short dipoles are included. The formula obtained is discussed in some detail and contour...

  11. Solar array flight dynamic experiment

    Science.gov (United States)

    Schock, Richard W.

    1987-01-01

    The purpose of the Solar Array Flight Dynamic Experiment (SAFDE) is to demonstrate the feasibility of on-orbit measurement and ground processing of large space structures' dynamic characteristics. Test definition or verification provides the dynamic characteristic accuracy required for control systems use. An illumination/measurement system was developed to fly on space shuttle flight STS-41D. The system was designed to dynamically evaluate a large solar array called the Solar Array Flight Experiment (SAFE) that had been scheduled for this flight. The SAFDE system consisted of a set of laser diode illuminators, retroreflective targets, an intelligent star tracker receiver and the associated equipment to power, condition, and record the results. In six tests on STS-41D, data was successfully acquired from 18 retroreflector targets and ground processed, post flight, to define the solar array's dynamic characteristic. The flight experiment proved the viability of on-orbit test definition of large space structures dynamic characteristics. Future large space structures controllability should be greatly enhanced by this capability.

  12. PHARUS : PHased ARray Universal SAR

    NARCIS (Netherlands)

    Paquay, M.H.A.; Vermeulen, B.C.B.; Koomen, P.J.; Hoogeboom, P.; Snoeij, P.; Pouwels, H.

    1996-01-01

    In the Netherlands, a polarimetric C-band aircraft SAR (Synthetic Aperture Radar) has been developed. The project is called PHARUS, an acronm for PHased ARray Universal SAR. This instrument serves remote sensing applications. The antenna system contains 48 active modules (expandable to 96). A module

  13. Development of micro-beam NRA for 3D-mapping of hydrogen distribution in solids: Application of tapered glass capillary to 6 MeV 15N ion

    International Nuclear Information System (INIS)

    Sekiba, D.; Yonemura, H.; Nebiki, T.; Wilde, M.; Ogura, S.; Yamashita, H.; Matsumoto, M.; Kasagi, J.; Iwamura, Y.; Itoh, T.; Matsuzaki, H.; Narusawa, T.; Fukutani, K.

    2008-01-01

    A micro-beam NRA system, by means of a resonant nuclear reaction 1 H( 15 N, αγ) 12 C, has been developed for the purpose of the 3D mapping of the hydrogen distribution in solids. To obtain the tens μm size of the beam spot, the combination of the newly proposed tapered glass capillary and a conventional quadrupole magnetic lens is employed. An Y patterned film on a substrate is prepared as an application of the developed system. The 6 MeV 15 N beam focused by glass capillaries down to 50 μm successfully shows the hydrogen distribution. The in-plane NRA profile implies that the beam emitted from the glass capillary outlet is parallel, although the original beam has a considerable divergence. The NRA measurements in the 10 3 Pa N 2 atmosphere due to the low gas conductance of the glass capillary is also demonstrated

  14. Sex-chromosome anaphase movements in crane-fly spermatocytes are coordinated: ultraviolet microbeam irradiation of one kinetochore of one sex chromosome blocks the movements of both sex chromosomes

    International Nuclear Information System (INIS)

    Swedak, J.A.M.; Forer, A.

    1987-01-01

    Sex chromosomes in crane-fly spermatocytes move polewards at anaphase after the autosomes have reached the poles. We irradiated one kinetochore of one sex chromosome using an ultraviolet microbeam. When both sex chromosomes were normally oriented, irradiation of a single kinetochore permanently blocked movement of both sex chromosomes. Irradiation of non-kinetochore chromosomal regions or of spindle fibres did not block movement, or blocked movement only temporarily. We argue that ultraviolet irradiation of one kinetochore blocks movement of both sex chromosomes because of effects on a 'signal' system. Irradiation of one kinetochore of a maloriented sex chromosome did not block motion of either sex chromosome. However, irradiation of one kinetochore of a normally oriented sex chromosome permanently blocked motion of both that sex chromosome and the maloriented sex chromosome. Thus for the signal system to allow the sex chromosomes to move to the pole each sex chromosome must have one spindle fibre to each pole. (author)

  15. Phased Array of Phased Arrays (PAPA) Laser Systems Architecture

    Science.gov (United States)

    McManamon, P. A. U. L. F.; Thompson, William

    This paper introduces and analyzes revolutionary laser system architecture capable of dramatically reducing the complexity of laser systems while simultaneously increasing capability. The architecture includes three major subsystems. The first is a phased array of laser sources. In this article, we discuss diode-pumped fiber lasers as the elements of the phased array, although other waveguide lasers can also be considered. The second provides wavefront control and electronics beam steering, as described in an IEEE Proceedings article on "Optical Phased Array Technology" [1]. The third is subaperture receiver technology. Combining these three technologies into a new laser systems architecture results in a system that has graceful degradation, can steer to as wide an angle as individual optical phased array subapertures, and can be scaled to high power and large apertures through phasing of a number of subapertures. Diode-pumped fiber lasers are appealing as laser sources because they are electrically pumped, efficient, relatively simple, and scalable to significant power levels (over 100 Watts has been demonstrated from a single diode-pumped fiber laser) [2]. The fiber laser design also lends itself to integration into a phased array. Fiber lasers have been phased. Initial phasing demonstrations have been at low power and were conducted by taking a single source, dividing it into multiple fibers, then phasing them together. To develop this technology further we need to use independent fiber lasers or fiber amplifiers, seeded by a common source, and to increase laser power. As we increase laser power, we will have to learn to cope with nonlinearities in the laser amplifiers. Optical Phased Array technology has demonstrated steering over a 90-degree field of regard [4], although this approach used additional optical components. If we use straightforward optical phased array beam steering without additional optics we can steer with high efficiency to about one-third

  16. DNA electrophoresis through microlithographic arrays

    International Nuclear Information System (INIS)

    Sevick, E.M.; Williams, D.R.M.

    1996-01-01

    Electrophoresis is one of the most widely used techniques in biochemistry and genetics for size-separating charged molecular chains such as DNA or synthetic polyelectrolytes. The separation is achieved by driving the chains through a gel with an external electric field. As a result of the field and the obstacles that the medium provides, the chains have different mobilities and are physically separated after a given process time. The macroscopically observed mobility scales inversely with chain size: small molecules move through the medium quickly while larger molecules move more slowly. However, electrophoresis remains a tool that has yet to be optimised for most efficient size separation of polyelectrolytes, particularly large polyelectrolytes, e.g. DNA in excess of 30-50 kbp. Microlithographic arrays etched with an ordered pattern of obstacles provide an attractive alternative to gel media and provide wider avenues for size separation of polyelectrolytes and promote a better understanding of the separation process. Its advantages over gels are (1) the ordered array is durable and can be re-used, (2) the array morphology is ordered and can be standardized for specific separation, and (3) calibration with a marker polyelectrolyte is not required as the array is reproduced to high precision. Most importantly, the array geometry can be graduated along the chip so as to expand the size-dependent regime over larger chain lengths and postpone saturation. In order to predict the effect of obstacles upon the chain-length dependence in mobility and hence, size separation, we study the dynamics of single chains using theory and simulation. We present recent work describing: 1) the release kinetics of a single DNA molecule hooked around a point, frictionless obstacle and in both weak and strong field limits, 2) the mobility of a chain impinging upon point obstacles in an ordered array of obstacles, demonstrating the wide range of interactions possible between the chain and

  17. Large Format Uncooled Focal Plane Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Uncooled focal plane arrays have improved dramatically and array sizes of 320x240 elements in a 50-?m pitch are commercially available at affordable cost. Black...

  18. Radiometric Testing of Magnesium Diboride Array (MDA)

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective is to develop a 2-Dimensional Far Infra-Red Magnesium Diboride Array (2D FIR MDA) to use in NASA's future planetary exploration instruments. The array...

  19. Microfabricated Multianalyte Sensor Arrays for Metabolic Monitoring

    National Research Council Canada - National Science Library

    Pishko, Michael V

    2006-01-01

    ...(ethylene glycol) diacrylate or PEG-DA on the array electrodes. The fabricated microarray sensors were individually addressable and with no cross-talk between adjacent array elements as assessed using cyclic voltammetry...

  20. Microfabricated Multianalyte Sensor Arrays for Metabolic Monitoring

    National Research Council Canada - National Science Library

    Pishko, Michael V

    2007-01-01

    ...(ethylene glycol) diacrylate or PEG-DA on the array electrodes. The fabricated microarray sensors were individually addressable and with no cross-talk between adjacent array elements as assessed using cyclic voltammetry...

  1. Leakage analysis of crossbar memristor arrays

    KAUST Repository

    Zidan, Mohammed A.

    2014-07-01

    Crossbar memristor arrays provide a promising high density alternative for the current memory and storage technologies. These arrays suffer from parasitic current components that significantly increase the power consumption, and could ruin the readout operation. In this work we study the trade-off between the crossbar array density and the power consumption required for its readout. Our analysis is based on simulating full memristor arrays on a SPICE platform.

  2. Method to fabricate hollow microneedle arrays

    Energy Technology Data Exchange (ETDEWEB)

    Kravitz, Stanley H [Placitas, NM; Ingersoll, David [Albuquerque, NM; Schmidt, Carrie [Los Lunas, NM; Flemming, Jeb [Albuquerque, NM

    2006-11-07

    An inexpensive and rapid method for fabricating arrays of hollow microneedles uses a photoetchable glass. Furthermore, the glass hollow microneedle array can be used to form a negative mold for replicating microneedles in biocompatible polymers or metals. These microneedle arrays can be used to extract fluids from plants or animals. Glucose transport through these hollow microneedles arrays has been found to be orders of magnitude more rapid than natural diffusion.

  3. Exergetic Optimization of a Solar Photovoltaic Array

    OpenAIRE

    Sarhaddi, Faramarz; Farahat, Said; Ajam, Hossein; Behzadmehr, Amin

    2009-01-01

    An exergetic optimization is developed to determine the optimal performance and design parameters of a solar photovoltaic (PV) array. A detailed energy and exergy analysis is carried out to evaluate the electrical performance, exergy destruction components, and exergy efficiency of a typical PV array. The exergy efficiency of a PV array obtained in this paper is a function of climatic, operating, and design parameters such as ambient temperature, solar radiation intensity, PV array temperatur...

  4. Safety System for a Towed Array

    Science.gov (United States)

    2017-09-25

    300196 1 of 13 SAFETY SYSTEM FOR A TOWED SOURCE STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured...invention is a towed array safety system and method of use that prevents the loss of a towed array cable and towed array handling system in the event of a...tension surge while retaining required safety features of the towed array handling system . (2) Description of the Prior Art [0004] There have

  5. High voltage load resistor array

    Science.gov (United States)

    Lehmann, Monty Ray [Smithfield, VA

    2005-01-18

    A high voltage resistor comprising an array of a plurality of parallel electrically connected resistor elements each containing a resistive solution, attached at each end thereof to an end plate, and about the circumference of each of the end plates, a corona reduction ring. Each of the resistor elements comprises an insulating tube having an electrode inserted into each end thereof and held in position by one or more hose clamps about the outer periphery of the insulating tube. According to a preferred embodiment, the electrode is fabricated from stainless steel and has a mushroom shape at one end, that inserted into the tube, and a flat end for engagement with the end plates that provides connection of the resistor array and with a load.

  6. Antenna Arrays and Automotive Applications

    CERN Document Server

    Rabinovich, Victor

    2013-01-01

    This book throws a lifeline to designers wading through mounds of antenna array patents looking for the most suitable systems for their projects. Drastically reducing the research time required to locate solutions to the latest challenges in automotive communications, it sorts and systematizes material on cutting-edge antenna arrays that feature multi-element communication systems with enormous potential for the automotive industry. These new systems promise to make driving safer and more efficient, opening up myriad applications, including vehicle-to-vehicle traffic that prevents collisions, automatic toll collection, vehicle location and fine-tuning for cruise control systems. This book’s exhaustive coverage begins with currently deployed systems, frequency ranges and key parameters. It proceeds to examine system geometry, analog and digital beam steering technology (including "smart" beams formed in noisy environments), maximizing signal-to-noise ratios, miniaturization, and base station technology that ...

  7. Invasive tightly coupled processor arrays

    CERN Document Server

    LARI, VAHID

    2016-01-01

    This book introduces new massively parallel computer (MPSoC) architectures called invasive tightly coupled processor arrays. It proposes strategies, architecture designs, and programming interfaces for invasive TCPAs that allow invading and subsequently executing loop programs with strict requirements or guarantees of non-functional execution qualities such as performance, power consumption, and reliability. For the first time, such a configurable processor array architecture consisting of locally interconnected VLIW processing elements can be claimed by programs, either in full or in part, using the principle of invasive computing. Invasive TCPAs provide unprecedented energy efficiency for the parallel execution of nested loop programs by avoiding any global memory access such as GPUs and may even support loops with complex dependencies such as loop-carried dependencies that are not amenable to parallel execution on GPUs. For this purpose, the book proposes different invasion strategies for claiming a desire...

  8. Subwavelength micropillar array terahertz lasers.

    Science.gov (United States)

    Krall, Michael; Brandstetter, Martin; Deutsch, Christoph; Detz, Hermann; Andrews, Aaron Maxwell; Schrenk, Werner; Strasser, Gottfried; Unterrainer, Karl

    2014-01-13

    We report on micropillar-based terahertz lasers with active pillars that are much smaller than the emission wavelength. These micropillar array lasers correspond to scaled-down band-edge photonic crystal lasers forming an active photonic metamaterial. In contrast to photonic crystal lasers which use significantly larger pillar structures, lasing emission is not observed close to high-symmetry points in the photonic band diagram, but in the effective medium regime. We measure stimulated emission at 4 THz for micropillar array lasers with pillar diameters of 5 µm. Our results not only demonstrate the integration of active subwavelength optics in a terahertz laser, but are also an important step towards the realization of nanowire-based terahertz lasers.

  9. Microneedle array electrode for human EEG recording.

    NARCIS (Netherlands)

    Lüttge, Regina; van Nieuwkasteele-Bystrova, Svetlana Nikolajevna; van Putten, Michel Johannes Antonius Maria; Vander Sloten, Jos; Verdonck, Pascal; Nyssen, Marc; Haueisen, Jens

    2009-01-01

    Microneedle array electrodes for EEG significantly reduce the mounting time, particularly by circumvention of the need for skin preparation by scrubbing. We designed a new replication process for numerous types of microneedle arrays. Here, polymer microneedle array electrodes with 64 microneedles,

  10. Ferroelectric transistor memory arrays on flexible foils

    NARCIS (Netherlands)

    Breemen, A. van; Kam, B.; Cobb, B.; Rodriguez, F.G.; Heck, G. van; Myny, K.; Marrani, A.; Vinciguerra, V.; Gelinck, G.H.

    2013-01-01

    In this paper, we successfully fabricated and operated passive matrix P(VDF-TrFE) transistor arrays, i.e. memory arrays in which no pass-transistors or other additional electronic components are used. Because of the smaller cell, a higher integration density is possible. We demonstrate arrays up to

  11. Towards Hybrid Array Types in SAC

    NARCIS (Netherlands)

    Grelck, C.; Tang, F.

    2014-01-01

    Array programming is characterised by a formal calculus of (regular, dense) multidimensional arrays that defines the relationships between structural properties like rank and shape as well as data set sizes. Operations in the array calculus often impose certain constraints on the relationships of

  12. Arrays of magnetic nanoparticles capped with alkylamines

    Indian Academy of Sciences (India)

    While there has been reasonable success in preparing arrays of metal and semiconducting chalcoginide nanoparticles, arrays of metal oxides are relatively unknown. [12,13]. We considered it important to prepare arrays of metal oxide particles with use- ful magnetic properties, particularly in view of their stability under ...

  13. Calibration strategies for the Cherenkov Telescope Array

    NARCIS (Netherlands)

    Gaug, M.; Berge, D.; Daniel, M.; Doro, M.; Förster, A.; Hofmann, W.; Maccarone, M.C.; Parsons, D.; de los Reyes Lopez, R.; van Eldik, C.

    2014-01-01

    The Central Calibration Facilities workpackage of the Cherenkov Telescope Array (CTA) observatory for very high energy gamma ray astronomy defines the overall calibration strategy of the array, develops dedicated hardware and software for the overall array calibration and coordinates the calibration

  14. Si Microwire Array Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Putnam, Morgan C.; Boettcher, Shannon W.; Kelzenberg, Michael D.; Turner-Evans, Daniel B.; Spurgeon, Joshua M.; Warren, Emily L.; Briggs, Ryan M.; Lewis, Nathan S.; Atwater, Harry A.

    2010-01-01

    Si microwire-array solar cells with Air Mass 1.5 Global conversion efficiencies of up to 7.9% have been fabricated using an active volume of Si equivalent to a 4 μm thick Si wafer. These solar cells exhibited open-circuit voltages of 500 mV, short-circuit current densities (J{sub sc}) of up to 24 mA cm{sup -2}, and fill factors >65% and employed Al{sub 2}O{sub 3} dielectric particles that scattered light incident in the space between the wires, a Ag back reflector that prevented the escape of incident illumination from the back surface of the solar cell, and an a-SiN{sub x}:H passivation/anti-reflection layer. Wire-array solar cells without some or all of these design features were also fabricated to demonstrate the importance of the light-trapping elements in achieving a high J{sub sc}. Scanning photocurrent microscopy images of the microwire-array solar cells revealed that the higher J{sub sc} of the most advanced cell design resulted from an increased absorption of light incident in the space between the wires. Spectral response measurements further revealed that solar cells with light-trapping elements exhibited improved red and infrared response, as compared to solar cells without light-trapping elements.

  15. LOFAR, the low frequency array

    Science.gov (United States)

    Vermeulen, R. C.

    2012-09-01

    LOFAR, the Low Frequency Array, is a next-generation radio telescope designed by ASTRON, with antenna stations concentrated in the north of the Netherlands and currently spread into Germany, France, Sweden and the United Kingdom; plans for more LOFAR stations exist in several other countries. Utilizing a novel, phased-array design, LOFAR is optimized for the largely unexplored low frequency range between 30 and 240 MHz. Digital beam-forming techniques make the LOFAR system agile and allow for rapid re-pointing of the telescopes as well as the potential for multiple simultaneous observations. Processing (e.g. cross-correlation) takes place in the LOFAR BlueGene/P supercomputer, and associated post-processing facilities. With its dense core (inner few km) array and long (more than 1000 km) interferometric baselines, LOFAR reaches unparalleled sensitivity and resolution in the low frequency radio regime. The International LOFAR Telescope (ILT) is now issuing its first call for observing projects that will be peer reviewed and selected for observing starting in December. Part of the allocations will be made on the basis of a fully Open Skies policy; there are also reserved fractions assigned by national consortia in return for contributions from their country to the ILT. In this invited talk, the gradually expanding complement of operationally verified observing modes and capabilities are reviewed, and some of the exciting first astronomical results are presented.

  16. The Colorado Lightning Mapping Array

    Science.gov (United States)

    Rison, W.; Krehbiel, P. R.; Thomas, R. J.; Rodeheffer, D.; Fuchs, B.

    2012-12-01

    A fifteen station Lightning Mapping Array (LMA) was installed in northern Colorado in the spring of 2012. While the driving force for the array was to produce 3-dimensional lightning data to support the Deep Convective Clouds and Chemistry (DC3) Experiment (Barth, this conference), data from the array are being used for several other projects. These include: electrification studies in conjunction with the CSU CHILL radar (Lang et al, this conference); observations of the parent lightning discharges of sprites (Lyons et al, this conference); trying to detect upward discharges triggered by wind turbines, characterizing conditions in which aircraft flying through clouds produce discharges which can be detected by the LMA, and other opportunities, such as observations of lightning in pyrocumulus clouds produced by the High Park Fire west of Fort Collins, CO. All the COLMA stations are solar-powered, and use broadband cellular modems for data communications. This makes the stations completely self-contained and autonomous, allowing a station to be installed anywhere a cellular signal is available. Because most of the stations were installed well away from anthropogenic noise sources, the COLMA is very sensitive. This is evidenced by the numerous plane tracks detected in its the vicinity. The diameter, D, of the COLMA is about 100 km, significantly larger than other LMAs. Because the error in the radial distance r is proportional to (r/D)2, and the error in the altitude z is proportional to (z/D)2, the larger array diameter greatly expands the usable range of the COLMA. The COLMA is able to detect and characterize lighting flashes to a distance of about 350 km from the array center. In addition to a web-based display (lightning.nmt.edu/colma), geo-referenced images are produced and updated at one-minute intervals. These geo-referenced images can be used to overlay the real-time lightning data on Google Earth and other mapping software. These displays were used by the DC3

  17. Acoustic array systems theory, implementation, and application

    CERN Document Server

    Bai, Mingsian R; Benesty, Jacob

    2013-01-01

    Presents a unified framework of far-field and near-field array techniques for noise source identification and sound field visualization, from theory to application. Acoustic Array Systems: Theory, Implementation, and Application provides an overview of microphone array technology with applications in noise source identification and sound field visualization. In the comprehensive treatment of microphone arrays, the topics covered include an introduction to the theory, far-field and near-field array signal processing algorithms, practical implementations, and common applic

  18. Status of wake and array loss research

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.L.

    1991-09-01

    In recent years, many projects have evaluated wind turbine wake effects and resultant array losses in both Europe and the United States. This paper examines the status of current knowledge about wake effects and array losses and suggests future research. Single-turbine wake characteristics have been studied extensively and are generally described well by existing theoretical models. Field measurements of wake effects in wind turbine arrays are largely limited to small arrays, with 2 to 4 rows of turbines. Few data have been published on wake effects within large arrays. Measurements of wake deficits downwind of large arrays that deficits are substantially larger and extend farther downwind than expected. Although array design models have been developed, these models have been tested and verified using only limited data from a few rows of wind turbines in complex terrain, whereas some of the largest arrays have more than 40 rows of wind turbines. Planned cooperative efforts with the wind industry will obtain existing data relevant to analyzing energy deficits within large arrays and identifying data sets for potential use in array model verification efforts. Future research being considered include a cooperative research experiment to obtain more definitive data on wake deficits and turbulence within and downwind of large arrays. 16 refs., 9 figs., 1 tab.

  19. Coupling Between Waveguide-Fed Slot Arrays

    Science.gov (United States)

    Rengarajan, Sembiam

    2011-01-01

    Coupling between two waveguide-fed planar slot arrays has been investigated using full-wave analysis. The analysis employs the method-of-moments solution to the pertinent coupled integral equations for the aperture electric field of all slots. In order to compute coupling between two arrays, the input port of the first array is excited with a TE(sub 10) mode wave while the second one is match-terminated. After solving the moment method matrix equations, the aperture fields of all slots are obtained and thereby the TE(sub 10) mode wave received at the input port of the second array is determined. Coupling between two arrays is the ratio of the wave amplitude arriving in the second array port to the incident wave amplitude at the first array port. The coupling mechanism has been studied as a function of spacing between arrays in different directions, e.g. the electric field plane, the magnetic field plane, and the diagonal plane. Computed coupling values are presented for different array geometries. This work is novel since it provides a good understanding of coupling between waveguide-fed slot arrays as a function of spacing and orientation for different aperture distributions and array architectures. This serves as a useful tool for antenna design engineers and system engineers.

  20. Design of circular differential microphone arrays

    CERN Document Server

    Benesty, Jacob; Cohen, Israel

    2015-01-01

    Recently, we proposed a completely novel and efficient way to design differential beamforming algorithms for linear microphone arrays. Thanks to this very flexible approach, any order of differential arrays can be designed. Moreover, they can be made robust against white noise amplification, which is the main inconvenience in these types of arrays. The other well-known problem with linear arrays is that electronic steering is not really feasible.  In this book, we extend all these fundamental ideas to circular microphone arrays and show that we can design small and compact differential arrays of any order that can be electronically steered in many different directions and offer a good degree of control of the white noise amplification problem, high directional gain, and frequency-independent response. We also present a number of practical examples, demonstrating that differential beamforming with circular microphone arrays is likely one of the best candidates for applications involving speech enhancement (i....

  1. Reducing fiber cross-talk in mineral fiber arrays

    OpenAIRE

    Daniel Lee Stark

    2017-01-01

    Monocentric optics replace current systems with diffraction limited performance. The fiber arrays have been the issue. Commercial expensive fiber arrays are available, but enhanced mineral fiber arrays offer very inexpensive fiber arrays.

  2. The FPGA Pixel Array Detector

    International Nuclear Information System (INIS)

    Hromalik, Marianne S.; Green, Katherine S.; Philipp, Hugh T.; Tate, Mark W.; Gruner, Sol M.

    2013-01-01

    A proposed design for a reconfigurable x-ray Pixel Array Detector (PAD) is described. It operates by integrating a high-end commercial field programmable gate array (FPGA) into a 3-layer device along with a high-resistivity diode detection layer and a custom, application-specific integrated circuit (ASIC) layer. The ASIC layer contains an energy-discriminating photon-counting front end with photon hits streamed directly to the FPGA via a massively parallel, high-speed data connection. FPGA resources can be allocated to perform user defined tasks on the pixel data streams, including the implementation of a direct time autocorrelation function (ACF) with time resolution down to 100 ns. Using the FPGA at the front end to calculate the ACF reduces the required data transfer rate by several orders of magnitude when compared to a fast framing detector. The FPGA-ASIC high-speed interface, as well as the in-FPGA implementation of a real-time ACF for x-ray photon correlation spectroscopy experiments has been designed and simulated. A 16×16 pixel prototype of the ASIC has been fabricated and is being tested. -- Highlights: ► We describe the novelty and need for the FPGA Pixel Array Detector. ► We describe the specifications and design of the Diode, ASIC and FPGA layers. ► We highlight the Autocorrelation Function (ACF) for speckle as an example application. ► Simulated FPGA output calculates the ACF for different input bitstreams to 100 ns. ► Reduced data transfer rate by 640× and sped up real-time ACF by 100× other methods.

  3. Space-Based Radar Array System Simulation and Validation.

    Science.gov (United States)

    1980-09-01

    external field RBCA (NBFA,3), Array of position vectors R pointing to the center of RBC(NBF,3) ’ array a or array b element current segments from array...to center of array a RBCA (NBFA,3) element current segments from array a element feedpoint TSXB, TSYB Array b phase factors YDEL Skew parameter for...Number of feedback modes used in mutual coupling calcu- lation (POLX, POLY, POLZ) Polarization vector of external field RBCA (NBFA,3), Array of position

  4. rasdaman Array Database: current status

    Science.gov (United States)

    Merticariu, George; Toader, Alexandru

    2015-04-01

    rasdaman (Raster Data Manager) is a Free Open Source Array Database Management System which provides functionality for storing and processing massive amounts of raster data in the form of multidimensional arrays. The user can access, process and delete the data using SQL. The key features of rasdaman are: flexibility (datasets of any dimensionality can be processed with the help of SQL queries), scalability (rasdaman's distributed architecture enables it to seamlessly run on cloud infrastructures while offering an increase in performance with the increase of computation resources), performance (real-time access, processing, mixing and filtering of arrays of any dimensionality) and reliability (legacy communication protocol replaced with a new one based on cutting edge technology - Google Protocol Buffers and ZeroMQ). Among the data with which the system works, we can count 1D time series, 2D remote sensing imagery, 3D image time series, 3D geophysical data, and 4D atmospheric and climate data. Most of these representations cannot be stored only in the form of raw arrays, as the location information of the contents is also important for having a correct geoposition on Earth. This is defined by ISO 19123 as coverage data. rasdaman provides coverage data support through the Petascope service. Extensions were added on top of rasdaman in order to provide support for the Geoscience community. The following OGC standards are currently supported: Web Map Service (WMS), Web Coverage Service (WCS), and Web Coverage Processing Service (WCPS). The Web Map Service is an extension which provides zoom and pan navigation over images provided by a map server. Starting with version 9.1, rasdaman supports WMS version 1.3. The Web Coverage Service provides capabilities for downloading multi-dimensional coverage data. Support is also provided for several extensions of this service: Subsetting Extension, Scaling Extension, and, starting with version 9.1, Transaction Extension, which

  5. Conformal Antenna Array Design Handbook

    Science.gov (United States)

    1981-09-01

    PLOTI-e2#Yo2) AsYSCL*(J-1 )-YSL CALL N~IE(7.*L ,-LH2tH~oto4HF4.0) GO TO 10 11 CALL PLOT(-oltY92) 10 YuY ..Y DX. XM/NX NNX=NX+1 DO 20 K-19NNX CALL PLUT...polynomial. Then the coefficients are determined from the Chebyshev polynomial (Taylor, 1952; Tseng and Cheng , 1968). As in the case of linear arrays, a...used ( Cheng and Tseng, 1967). Difference pattern parameters such as slope (Powers, 1967) or directivity (Bayliss, 1968) can also be maximized at the

  6. Coated carbon nanotube array electrodes

    Science.gov (United States)

    Ren, Zhifeng [Newton, MA; Wen, Jian [Newton, MA; Chen, Jinghua [Chestnut Hill, MA; Huang, Zhongping [Belmont, MA; Wang, Dezhi [Wellesley, MA

    2008-10-28

    The present invention provides conductive carbon nanotube (CNT) electrode materials comprising aligned CNT substrates coated with an electrically conducting polymer, and the fabrication of electrodes for use in high performance electrical energy storage devices. In particular, the present invention provides conductive CNTs electrode material whose electrical properties render them especially suitable for use in high efficiency rechargeable batteries. The present invention also provides methods for obtaining surface modified conductive CNT electrode materials comprising an array of individual linear, aligned CNTs having a uniform surface coating of an electrically conductive polymer such as polypyrrole, and their use in electrical energy storage devices.

  7. Layout Of Antennas And Cables In A Large Array

    Science.gov (United States)

    Logan, Ronald T., Jr.

    1995-01-01

    Layout devised to minimize total land area occupied by large phased array of antennas and to minimize total length of cables in array. In original intended application, array expanded version of array of paraboloidal-dish microwave communication antennas of Deep Space Network. Layout also advantageous for other phased arrays of antennas and antenna elements, including notably printed-circuit microwave antenna arrays.

  8. ArrayBridge: Interweaving declarative array processing with high-performance computing

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Haoyuan [The Ohio State Univ., Columbus, OH (United States); Floratos, Sofoklis [The Ohio State Univ., Columbus, OH (United States); Blanas, Spyros [The Ohio State Univ., Columbus, OH (United States); Byna, Suren [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Prabhat, Prabhat [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wu, Kesheng [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Brown, Paul [Paradigm4, Inc., Waltham, MA (United States)

    2017-05-04

    Scientists are increasingly turning to datacenter-scale computers to produce and analyze massive arrays. Despite decades of database research that extols the virtues of declarative query processing, scientists still write, debug and parallelize imperative HPC kernels even for the most mundane queries. This impedance mismatch has been partly attributed to the cumbersome data loading process; in response, the database community has proposed in situ mechanisms to access data in scientific file formats. Scientists, however, desire more than a passive access method that reads arrays from files. This paper describes ArrayBridge, a bi-directional array view mechanism for scientific file formats, that aims to make declarative array manipulations interoperable with imperative file-centric analyses. Our prototype implementation of ArrayBridge uses HDF5 as the underlying array storage library and seamlessly integrates into the SciDB open-source array database system. In addition to fast querying over external array objects, ArrayBridge produces arrays in the HDF5 file format just as easily as it can read from it. ArrayBridge also supports time travel queries from imperative kernels through the unmodified HDF5 API, and automatically deduplicates between array versions for space efficiency. Our extensive performance evaluation in NERSC, a large-scale scientific computing facility, shows that ArrayBridge exhibits statistically indistinguishable performance and I/O scalability to the native SciDB storage engine.

  9. Micromirror arrays for object selection

    Science.gov (United States)

    Waldis, Severin; Zamkotsian, Frederic; Clerc, Pierre-Andre; Zickar, Michael; Noell, Wilfried; de Rooij, Nico

    2007-10-01

    We report on micromirror arrays being developed for object selection in Multi Object Spectrographs for astronomical applications. The micromirrors are etched in bulk single crystal silicon whereas the cantilever type suspension is realized by surface micromachining. One micromirror element is 100μm × 200μm in size. The micromirrors are actuated electrostatically by electrodes located on a second chip. The use of silicon on insulator (SOI) wafers for both mirror and electrode chip ensures thermal compatibility for cryogenic operation. A system of multiple landing beams has been developed, which passively locks the mirror at a well defined tilt angle when actuated. The mechanical tilt angle obtained is 20° at a pull-in voltage of 90V. Measurements with an optical profiler showed that the tilt angle of the actuated and locked mirror is stable with a precision of one arc minute over a range of 15V. This locking system makes the tilt angle merely independent from process variations across the wafer and thus provides uniform tilt angle over the whole array. The precision on tilt angle from mirror to mirror measured is one arc minute. The surface quality of the mirrors in actuated state is better than 10nm peak-to-valley and the local roughness is around 1nm RMS. Preliminary cryogenic tests showed that the micromirror device sustains 120K without any structural damage.

  10. Light Trapping with Silicon Light Funnel Arrays.

    Science.gov (United States)

    Prajapati, Ashish; Nissan, Yuval; Gabay, Tamir; Shalev, Gil

    2018-03-19

    Silicon light funnels are three-dimensional subwavelength structures in the shape of inverted cones with respect to the incoming illumination. Light funnel (LF) arrays can serve as efficient absorbing layers on account of their light trapping capabilities, which are associated with the presence of high-density complex Mie modes. Specifically, light funnel arrays exhibit broadband absorption enhancement of the solar spectrum. In the current study, we numerically explore the optical coupling between surface light funnel arrays and the underlying substrates. We show that the absorption in the LF array-substrate complex is higher than the absorption in LF arrays of the same height (~10% increase). This, we suggest, implies that a LF array serves as an efficient surface element that imparts additional momentum components to the impinging illumination, and hence optically excites the substrate by near-field light concentration, excitation of traveling guided modes in the substrate, and mode hybridization.

  11. Light Trapping with Silicon Light Funnel Arrays

    Directory of Open Access Journals (Sweden)

    Ashish Prajapati

    2018-03-01

    Full Text Available Silicon light funnels are three-dimensional subwavelength structures in the shape of inverted cones with respect to the incoming illumination. Light funnel (LF arrays can serve as efficient absorbing layers on account of their light trapping capabilities, which are associated with the presence of high-density complex Mie modes. Specifically, light funnel arrays exhibit broadband absorption enhancement of the solar spectrum. In the current study, we numerically explore the optical coupling between surface light funnel arrays and the underlying substrates. We show that the absorption in the LF array-substrate complex is higher than the absorption in LF arrays of the same height (~10% increase. This, we suggest, implies that a LF array serves as an efficient surface element that imparts additional momentum components to the impinging illumination, and hence optically excites the substrate by near-field light concentration, excitation of traveling guided modes in the substrate, and mode hybridization.

  12. Photovoltaic array space power plus diagnostics experiment

    Science.gov (United States)

    Guidice, Donald A.

    1990-01-01

    The objective of the Photovoltaic Array Space Power Plus Diagnostics (PASP Plus) experiment is to measure the effects of the interaction of the low- to mid-altitude space environment on the performance of a diverse set of small solar-cell arrays (planar and concentrator, representative of present and future military technologies) under differing conditions of velocity-vector orientation and simulated (by biasing) high-voltage operation. Solar arrays to be tested include Si and GaAs planar arrays and several types of GaAs concentrator arrays. Diagnostics (a Langmuir probe and a pressure gauge) and a transient pulse monitor (to measure radiated and conducted EMI during arcing) will be used to determine the impact of the environment on array operation to help verify various interactions models. Results from a successful PASP Plus flight will furnish answers to important interactions questions and provide inputs for design and test standards for photovoltaic space-power subsystems.

  13. Space and power efficient hybrid counters array

    Science.gov (United States)

    Gara, Alan G [Mount Kisco, NY; Salapura, Valentina [Chappaqua, NY

    2009-05-12

    A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

  14. Generating Milton Babbitt's all-partition arrays

    DEFF Research Database (Denmark)

    Bemman, Brian; Meredith, David

    2016-01-01

    In most of Milton Babbitt's (1916–2011) works written since the early 1960s, both the pitch and rhythmic content is organized according to a highly constrained structure known as the all-partition array. The all-partition array provides a framework that ensures that as many different forms...... backtracking algorithm for generating a particular type of all-partition array found in Babbitt’s works, known as a Smalley array. Constructing such an array is a difficult task, and we present two heuristics for helping to generate this type of structure. We provide the parameter values required...... by this algorithm to generate the specific all-partition arrays used in three of Babbitt’s works. Finally, we evaluate the algorithm and the heuristics in terms of how well they predict the sequences of integer partitions used in two of Babbitt’s works. We also explore the effect of the heuristics...

  15. Compaction of polydimethylsiloxane due to nitrogen ion irradiation and its application for creating microlens arrays

    Czech Academy of Sciences Publication Activity Database

    Nagy, G. U. L.; Lavrentiev, Vasyl; Banyasz, I.; Szilasi, S. Z.; Havránek, Vladimír; Voseček, Václav; Huszank, R.; Rajta, I.

    2017-01-01

    Roč. 636, AUG (2017), s. 634-638 ISSN 0040-6090 R&D Projects: GA MŠk LM2015056 Institutional support: RVO:61389005 Keywords : ion microbeam * microprobe * polydimethylsioloxane * microlens Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nuclear physics Impact factor: 1.879, year: 2016

  16. Mapping Electrical Crosstalk in Pixelated Sensor Arrays

    Science.gov (United States)

    Seshadri, Suresh (Inventor); Cole, David (Inventor); Smith, Roger M. (Inventor); Hancock, Bruce R. (Inventor)

    2017-01-01

    The effects of inter pixel capacitance in a pixilated array may be measured by first resetting all pixels in the array to a first voltage, where a first image is read out, followed by resetting only a subset of pixels in the array to a second voltage, where a second image is read out, where the difference in the first and second images provide information about the inter pixel capacitance. Other embodiments are described and claimed.

  17. Halbach arrays in precision motion control

    Energy Technology Data Exchange (ETDEWEB)

    Trumper, D.L.; Williams, M.E. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1995-02-01

    The Halbach array was developed for use as an optical element in particle accelerators. Following up on a suggestion from Klaus Halbach, the authors have investigated the utility of such arrays as the permanent magnet structure for synchronous machines in cartesian, polar, and cylindrical geometries. Their work has focused on the design of a novel Halbach array linear motor for use in a magnetic suspension stage for photolithography. This paper presents the details of the motor design and its force and power characteristics.

  18. Big Data Challenges for Large Radio Arrays

    Science.gov (United States)

    Jones, Dayton L.; Wagstaff, Kiri; Thompson, David; D'Addario, Larry; Navarro, Robert; Mattmann, Chris; Majid, Walid; Lazio, Joseph; Preston, Robert; Rebbapragada, Umaa

    2012-01-01

    Future large radio astronomy arrays, particularly the Square Kilometre Array (SKA), will be able to generate data at rates far higher than can be analyzed or stored affordably with current practices. This is, by definition, a "big data" problem, and requires an end-to-end solution if future radio arrays are to reach their full scientific potential. Similar data processing, transport, storage, and management challenges face next-generation facilities in many other fields.

  19. Multi-Channel Capacitive Sensor Arrays

    OpenAIRE

    Wang, Bingnan; Long, Jiang; Teo, Koon Hoo

    2016-01-01

    In this paper, multi-channel capacitive sensor arrays based on microstrip band-stop filters are studied. The sensor arrays can be used to detect the proximity of objects at different positions and directions. Each capacitive sensing structure in the array is connected to an inductive element to form resonance at different frequencies. The resonances are designed to be isolated in the frequency spectrum, such that the change in one channel does not affect resonances at other channels. The indu...

  20. Magnetic remanence of Josephson junction arrays

    OpenAIRE

    Passos, W. A. C.; Araujo-Moreira, F. M.; Ortiz, W. A.

    1999-01-01

    In this work we study the magnetic remanence exhibited by Josephson junction arrays in response to an excitation with an AC magnetic field. The effect, predicted by numerical simulations to occur in a range of temperatures, is clearly seen in our tridimensional disordered arrays. We also discuss the influence of the critical current distribution on the temperature interval within which the array develops a magnetic remanence. This effect can be used to determine the critical current distribut...

  1. Processes and Materials for Flexible PV Arrays

    National Research Council Canada - National Science Library

    Gierow, Paul

    2002-01-01

    .... A parallel incentive for development of flexible PV arrays are the possibilities of synergistic advantages for certain types of spacecraft, in particular the Solar Thermal Propulsion (STP) Vehicle...

  2. Large Format Uncooled Focal Plane Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Black Forest Engineering has identified innovative modifications in uncooled focal plane array (UFPA) architecture and processing that allows development of large...

  3. Gigapixel imaging with microlens arrays

    Science.gov (United States)

    Orth, Antony; Schonbrun, Ethan

    2016-03-01

    A crucial part of the drug discovery process involves imaging the response of thousands of cell cultures to candidate drugs. Quantitative parameters from these "high content screens", such as protein expression and cell morphology, are extracted from fluorescence and brightfield micrographs. Due to the sheer number of cells that need to imaged for adequate statistics, the imaging time itself is a major bottleneck. Automated microscopes image small fields-of-view (FOVs) serially, which are then stitched together to form gigapixel-scale mosaics. We have developed a microscopy architecture that reduces mechanical overhead of traditional large field-of-view by parallelizing the image capture process. Instead of a single objective lens imaging FOVs one by one, we employ a microlens array for continuous photon capture, resulting in a 3-fold throughput increase. In this contribution, we present the design and imaging results of this microscopy architecture in three different contrast modes: multichannel fluorescence, hyperspectral fluorescence and brightfield.

  4. A Portable Diode Array Spectrophotometer.

    Science.gov (United States)

    Stephenson, David

    2016-05-01

    A cheap portable visible light spectrometer is presented. The spectrometer uses readily sourced items and could be constructed by anyone with a knowledge of electronics. The spectrometer covers the wavelength range 450-725 nm with a resolution better than 5 nm. The spectrometer uses a diffraction grating to separate wavelengths, which are detected using a 128-element diode array, the output of which is analyzed using a microprocessor. The spectrum is displayed on a small liquid crystal display screen and can be saved to a micro SD card for later analysis. Battery life (2 × AAA) is estimated to be 200 hours. The overall dimensions of the unit are 120 × 65 × 60 mm, and it weighs about 200 g. © The Author(s) 2016.

  5. Array abstractions for GPU programming

    DEFF Research Database (Denmark)

    Dybdal, Martin

    The shift towards massively parallel hardware platforms for highperformance computing tasks has introduced a need for improved programming models that facilitate ease of reasoning for both users and compiler optimization. A promising direction is the field of functional data-parallel programming......, for which functional invariants can be utilized by optimizing compilers to perform large program transformations automatically. However, the previous work in this area allow users only limited ability to reason about the performance of algorithms. For this reason, such languages have yet to see wide...... industrial adoption. We present two programming languages that attempt at both supporting industrial applications and providing reasoning tools for hierarchical data-parallel architectures, such as GPUs. First, we present TAIL, an array based intermediate language and compiler framework for compiling a large...

  6. Conformable eddy current array delivery

    Science.gov (United States)

    Summan, Rahul; Pierce, Gareth; Macleod, Charles; Mineo, Carmelo; Riise, Jonathan; Morozov, Maxim; Dobie, Gordon; Bolton, Gary; Raude, Angélique; Dalpé, Colombe; Braumann, Johannes

    2016-02-01

    The external surface of stainless steel containers used for the interim storage of nuclear material may be subject to Atmospherically Induced Stress Corrosion Cracking (AISCC). The inspection of such containers poses a significant challenge due to the large quantities involved; therefore, automating the inspection process is of considerable interest. This paper reports upon a proof-of-concept project concerning the automated NDT of a set of test containers containing artificially generated AISCCs. An Eddy current array probe with a conformable padded surface from Eddyfi was used as the NDT sensor and end effector on a KUKA KR5 arc HW robot. A kinematically valid cylindrical raster scan path was designed using the KUKA|PRC path planning software. Custom software was then written to interface measurement acquisition from the Eddyfi hardware with the motion control of the robot. Preliminary results and analysis are presented from scanning two canisters.

  7. Scanning strategies for imaging arrays

    Science.gov (United States)

    Kovács, Attila

    2008-07-01

    Large-format (sub)millimeter wavelength imaging arrays are best operated in scanning observing modes rather than traditional position-switched (chopped) modes. The choice of observing mode is critical for isolating source signals from various types of noise interference, especially for ground-based instrumentation operating under a bright atmosphere. Ideal observing strategies can combat 1/f noise, resist instrumental defects, sensitively recover emission on large scales, and provide an even field coverage - all under feasible requirements of telescope movement. This work aims to guide the design of observing patterns that maximize scientific returns. It also compares some of the popular choices of observing modes for (sub)millimeter imaging, such as random, Lissajous, billiard, spiral, On-The-Fly (OTF), DREAM, chopped and stare patterns. Many of the conclusions are also applicable other imaging applications and imaging in one dimension (e.g. spectroscopic observations).

  8. LOFAR- The Low Frequency Array

    Science.gov (United States)

    Falcke, H. D. E.

    2006-08-01

    LOFAR is an innovative radio telescope in the frequency range of 10-240 MHz, realized as a phased array. It will become the largest radio telescope in the world in the time frame 2006-2010, located in Northern Europe. LOFAR is being implemented as a Wide Area Sensor Network which connects thousands of cheap sensors spread throughout the country to a central super computer using an ultra-broadband, synchronized data network. As the central processor IBM has provided its Blue Gene/L supercomputer. It will process streaming data with about 0.5 Terabit per second. Many simple radio antennas connected to the network turn it into a huge radio telescope for cosmological studies. In addition, geophones will turn LOFAR into an earthquake monitoring system and infrasound and meteorology sensors will turn LOFAR into a real-time weather monitoring array for agricultural applications. LOFAR is the first radio telescopes that can listen to radio signals from the entire sky overhead, on all time scales, at a large range of frequencies, and even look back in time for a couple of seconds. The main strength of LOFAR are surveys. One goal is to detect the first generation of black holes and galaxies in the universe during the epoch of reionization and study hydrogen formed after the big bang. LOFAR is also an ideal system to discover transient and sporadic radio signals. Likely transient sources to be discovered with LOFAR are bursting stars and Jupiter-like planets, gamma-ray bursts, radio outbursts from black holes, but also lightning on Earth and even radio flashes from ultra-high energy cosmic particles hitting the Earth atmosphere. Some LOFAR prototypes have recently been built. They have produced the first instantaneous all-sky maps and discovered the radio emission from cosmic particle air showers.

  9. Micromirror Array Control of a Phase-Locked Laser Diode Array

    Science.gov (United States)

    1995-12-01

    mirror. These mirrors were invented by Larry Hornbeck of Texas Instruments approximately 15 years ago. Two dimensional arrays of micromirrors are...AFIT/GAP/ENP/95D-2 MICROMIRROR ARRAY CONTROL OF A PHASE-LOCKED LASER DIODE ARRAY THESIS Carl J. Christensen, Captain, USAF AFIT/GAP/ENP/95D-2...Approved for public release; distribution unlimited. /99 (;/ Ig M 5 -5 DTiC QUALITY IITSYEGTED AFIT/GAP/ENP/95D-2 MICROMIRROR ARRAY CONTROL OF A PHASE-LOCKED

  10. Imaging spectroscopy using embedded diffractive optical arrays

    Science.gov (United States)

    Hinnrichs, Michele; Hinnrichs, Bradford

    2017-09-01

    Pacific Advanced Technology (PAT) has developed an infrared hyperspectral camera based on diffractive optic arrays. This approach to hyperspectral imaging has been demonstrated in all three infrared bands SWIR, MWIR and LWIR. The hyperspectral optical system has been integrated into the cold-shield of the sensor enabling the small size and weight of this infrared hyperspectral sensor. This new and innovative approach to an infrared hyperspectral imaging spectrometer uses micro-optics that are made up of an area array of diffractive optical elements where each element is tuned to image a different spectral region on a common focal plane array. The lenslet array is embedded in the cold-shield of the sensor and actuated with a miniature piezo-electric motor. This approach enables rapid infrared spectral imaging with multiple spectral images collected and processed simultaneously each frame of the camera. This paper will present our optical mechanical design approach which results in an infrared hyper-spectral imaging system that is small enough for a payload on a small satellite, mini-UAV, commercial quadcopter or man portable. Also, an application of how this spectral imaging technology can easily be used to quantify the mass and volume flow rates of hydrocarbon gases. The diffractive optical elements used in the lenslet array are blazed gratings where each lenslet is tuned for a different spectral bandpass. The lenslets are configured in an area array placed a few millimeters above the focal plane and embedded in the cold-shield to reduce the background signal normally associated with the optics. The detector array is divided into sub-images covered by each lenslet. We have developed various systems using a different number of lenslets in the area array. Depending on the size of the focal plane and the diameter of the lenslet array will determine the number of simultaneous different spectral images collected each frame of the camera. A 2 x 2 lenslet array will image

  11. Dynamic array of dark optical traps

    DEFF Research Database (Denmark)

    Daria, V.R.; Rodrigo, P.J.; Glückstad, J.

    2004-01-01

    A dynamic array of dark optical traps is generated for simultaneous trapping and arbitrary manipulation of multiple low-index microstructures. The dynamic intensity patterns forming the dark optical trap arrays are generated using a nearly loss-less phase-to-intensity conversion of a phase-encode...

  12. Stochastic Beamforming via Compact Antenna Arrays

    DEFF Research Database (Denmark)

    Alrabadi, Osama; Pedersen, Gert Frølund

    2012-01-01

    The paper investigates the average beamforming (BF) gain of compact antenna arrays when statistical channel knowledge is available. The optimal excitation (precoding vector) and impedance termination that maximize the average BF gain are a compromise between the ones that maximize the array...

  13. Adaptive motion compensation in sonar array processing

    NARCIS (Netherlands)

    Groen, J.

    2006-01-01

    In recent years, sonar performance has mainly improved via a significant increase in array ap-erture, signal bandwidth and computational power. This thesis aims at improving sonar array processing techniques based on these three steps forward. In applications such as anti-submarine warfare and mine

  14. Element sharing in interleaved antenna arrays

    CSIR Research Space (South Africa)

    Du Plessis, WP

    2012-03-01

    Full Text Available The effect of allowing shared elements in interleaved thinned arrays is investigated. The sidelobe level (SLL) as a function of the number of shared elements mirrors the SLL of thinned arrays as a function of filling factor because the number...

  15. Refracting surface plasmon polaritons with nanoparticle arrays

    DEFF Research Database (Denmark)

    Radko, I.P.; Evlyukhin, A.B.; Boltasseva, Alexandra

    2008-01-01

    Refraction of surface plasmon polaritons (SPPs) by various structures formed by a 100-nm-period square lattice of gold nanoparticles on top of a gold film is studied by leakage radiation microscopy. SPP refraction by a triangular-shaped nanoparticle array indicates that the SPP effective refractive...... to design nanoparticle arrays for specific applications requiring in-plane SPP manipulation....

  16. Dumand-array data-acquisition system

    International Nuclear Information System (INIS)

    Brenner, A.E.; Theriot, D.; Dau, W.D.; Geelhood, B.D.; Harris, F.; Learned, J.G.; Stenger, V.; March, R.; Roos, C.; Shumard, E.

    1982-04-01

    An overall data acquisition approach for DUMAND is described. The scheme assumes one array to shore optical fiber transmission line for each string of the array. The basic event sampling period is approx. 13 μsec. All potentially interesting data is transmitted to shore where the major processing is performed

  17. The lofar phased array telescope system

    NARCIS (Netherlands)

    Gunst, André W.; Bentum, Marinus Jan

    2010-01-01

    The Low Frequency Array (LOFAR) is the largest telescope in the world operating at a frequency range from 30 to 240 MHz. LOFAR is the first radio telescope of its size which uses phased array principles to detect radio signals. More than 10,000 antennas are installed in the field. The antennas are

  18. Antennas for Frequency Reconfigurable Phased Arrays

    NARCIS (Netherlands)

    Haider, S.N.

    2015-01-01

    Sensors such as phased array radars play a crucial role in public safety. They are unavoidable for surveillance, threat identification and post-disaster management. However, different scenarios impose immensely diverse requirements for these systems. Phased array systems occupy a large space. In

  19. Overview arraying techniques for deep space communications

    Science.gov (United States)

    Mileant, A.; Hinedi, S.

    1994-01-01

    Four different arraying schemes applicable to deep space communications are discussed and analyzed. These include symbol stream combining (SSC), baseband combining (BC), carrier arraying (CA) and full spectrum combining (FSC). Complexity versus performance is traded off throughout the paper and benefits to the reception of existing spacecraft signals are discussed.

  20. Diagnostics of the BIOMASS feed array prototype

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Pivnenko, Sergey; Pontoppidan, Kennie Nybo

    2013-01-01

    The 3D reconstruction algorithm is applied to the prototype feed array of the BIOMASS synthetic aperture radar, recently measured at the DTU-ESA Spherical Near-Field Antenna Test Facility in Denmark. Careful analysis of the measured feed array data has shown that the test support structure...

  1. ALMA - the Atacama Large Millimeter Array

    NARCIS (Netherlands)

    Wild, W.; Cunningham, C.

    2002-01-01

    The Atacama Large Millimeter Array (ALMA) is a major ground based project for millimeter and submillimeter astronomy to be realized during this decade. It comprises an array of 64 telescopes of 12 meter diameter, each equipped with 10 receivers bands covering the atmospheric windows from 30 GHz to

  2. Spherical Horn Array for Wideband Propagation Measurements

    DEFF Research Database (Denmark)

    Franek, Ondrej; Pedersen, Gert Frølund

    2011-01-01

    properties and coupling between the elements are investigated via measurements and numerical simulations. Radiation patterns and sum beams of the array on selected frequencies throughout the band are also presented. Based on the obtained results it is concluded that the array is a good candidate...

  3. Maximum gain of Yagi-Uda arrays

    DEFF Research Database (Denmark)

    Bojsen, J.H.; Schjær-Jacobsen, Hans; Nilsson, E.

    1971-01-01

    Numerical optimisation techniques have been used to find the maximum gain of some specific parasitic arrays. The gain of an array of infinitely thin, equispaced dipoles loaded with arbitrary reactances has been optimised. The results show that standard travelling-wave design methods are not optimum...

  4. Law of substitution for mixed arrays

    International Nuclear Information System (INIS)

    Koudelka, A.J.

    1987-01-01

    The nuclear safety justification of a mixed array of dissimilar fissile units of metal units and dilute solution units, according to Clayton, has been a persistent and nagging problem. Dissimilar uranium metal or dissimilar uranium solution units in a mixed array can also create a modeling nightmare for the nuclear criticality safety engineer. Now, a calculational method known as the Law of Substitution has been developed to ensure that the k/sub eff/ of an array of uranium metal and uranium solution units will satisfy any k/sub eff/ limit set by the nuclear safety engineer. The nuclear criticality safety engineer can utilize the Law of Substitution to safely mix or substitute different uranium metal units, different uranium solution units, and more importantly, uranium metal and dilute UO 2 solution units in an array. The Law of Substitution is as follows: (1) calculate the k/sub eff/ of each unit type in its own infinite planar array. (2) Determine the edge-to-edge spacing of the infinite planar array of each type of unit to satisfy a desired k/sub eff/. (3) Select the largest edge-to-edge spacing from among the similar units in their infinite planar arrays and use that spacing for the finite or infinite planar array of mixed units

  5. The Astronomical Low-Frequency Array

    Science.gov (United States)

    Jones, D. L.; Allen, R. J.; Blume, W. H.; Desch, M. M.; Erickson, W. C.; Kaiser, M. L.; Kassim, N. E.; Kuiper, T. B. H.; Mahoney, M. J.; Marsh, K. A.; hide

    1996-01-01

    An array of satellites is proposed to make astronomic observations in the low frequency range of a few tens of MHz down to roughly 100 kHz, a range that cannot be observed through the ionosphere. The array would be in a solar orbit to avoid radio interference from Earth and to simplify trajectory tracking and control.

  6. The Expanded Very Large Array Project

    Science.gov (United States)

    Perley, Rick

    2012-10-01

    The Expanded Very Large Array Project, begun in 2001, is now completed -- on time, on budget, and ``on spec.'' The major goal of the project was to multiply the key observational capabilities of the Very Large Array -- the world's most powerful, versatile, and productive radio telescope -- by a factor of at least an order of magnitude by implementation of modern technologies. The result of the project is an operationally new telescope -- renamed the Jansky Very Large Array -- which is capable of new science unimagined in 1980, when the original VLA was completed. In this talk, I will review the goals of the project, and describe the new capabilities of the Jansky Very Large Array. Already, the array is providing fabulous new insights into the physics of the universe,and I will spend the majority of the time describing examples of new results.

  7. Analyzing Array Manipulating Programs by Program Transformation

    Science.gov (United States)

    Cornish, J. Robert M.; Gange, Graeme; Navas, Jorge A.; Schachte, Peter; Sondergaard, Harald; Stuckey, Peter J.

    2014-01-01

    We explore a transformational approach to the problem of verifying simple array-manipulating programs. Traditionally, verification of such programs requires intricate analysis machinery to reason with universally quantified statements about symbolic array segments, such as "every data item stored in the segment A[i] to A[j] is equal to the corresponding item stored in the segment B[i] to B[j]." We define a simple abstract machine which allows for set-valued variables and we show how to translate programs with array operations to array-free code for this machine. For the purpose of program analysis, the translated program remains faithful to the semantics of array manipulation. Based on our implementation in LLVM, we evaluate the approach with respect to its ability to extract useful invariants and the cost in terms of code size.

  8. Milliarcsecond Astronomy with the CHARA Array

    Science.gov (United States)

    Schaefer, Gail; ten Brummelaar, Theo; Gies, Douglas; Jones, Jeremy; Farrington, Christopher

    2018-01-01

    The Center for High Angular Resolution Astronomy offers 50 nights per year of open access time at the CHARA Array. The Array consists of six telescopes linked together as an interferometer, providing sub-milliarcsecond resolution in the optical and near-infrared. The Array enables a variety of scientific studies, including measuring stellar angular diameters, imaging stellar shapes and surface features, mapping the orbits of close binary companions, and resolving circumstellar environments. The open access time is part of an NSF/MSIP funded program to open the CHARA Array to the broader astronomical community. As part of the program, we will build a searchable database for the CHARA data archive and run a series of one-day community workshops at different locations across the country to expand the user base for stellar interferometry and encourage new scientific investigations with the CHARA Array.

  9. Spatial normalization of array-CGH data

    Directory of Open Access Journals (Sweden)

    Brennetot Caroline

    2006-05-01

    Full Text Available Abstract Background Array-based comparative genomic hybridization (array-CGH is a recently developed technique for analyzing changes in DNA copy number. As in all microarray analyses, normalization is required to correct for experimental artifacts while preserving the true biological signal. We investigated various sources of systematic variation in array-CGH data and identified two distinct types of spatial effect of no biological relevance as the predominant experimental artifacts: continuous spatial gradients and local spatial bias. Local spatial bias affects a large proportion of arrays, and has not previously been considered in array-CGH experiments. Results We show that existing normalization techniques do not correct these spatial effects properly. We therefore developed an automatic method for the spatial normalization of array-CGH data. This method makes it possible to delineate and to eliminate and/or correct areas affected by spatial bias. It is based on the combination of a spatial segmentation algorithm called NEM (Neighborhood Expectation Maximization and spatial trend estimation. We defined quality criteria for array-CGH data, demonstrating significant improvements in data quality with our method for three data sets coming from two different platforms (198, 175 and 26 BAC-arrays. Conclusion We have designed an automatic algorithm for the spatial normalization of BAC CGH-array data, preventing the misinterpretation of experimental artifacts as biologically relevant outliers in the genomic profile. This algorithm is implemented in the R package MANOR (Micro-Array NORmalization, which is described at http://bioinfo.curie.fr/projects/manor and available from the Bioconductor site http://www.bioconductor.org. It can also be tested on the CAPweb bioinformatics platform at http://bioinfo.curie.fr/CAPweb.

  10. Synthesis of unequally spaced linear antenna arrays | Hassen ...

    African Journals Online (AJOL)

    Synthesis of unequally spaced linear antenna arrays. MR Hassen, W Woldemariam ... Also the method needs fewer number of array elements to synthesize an array exhibiting the same (or better) level of directivity and sidelobe level in comparison with uniform arrays. Reduction in number of array elements has a positive ...

  11. AGATA - Advanced GAmma Tracking Array

    Energy Technology Data Exchange (ETDEWEB)

    Akkoyun, S. [Department of Physics, Faculty of Science, Ankara University, 06100 Tandogan, Ankara (Turkey); Algora, A. [IFIC, CSIC-Universitat de Valencia, E-46980 Paterna (Spain); Alikhani, B. [IKP, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Ameil, F. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Angelis, G. de [INFN Laboratori Nazionali di Legnaro, IT-35020 Padova (Italy); Arnold, L. [Universite de Strasbourg, IPHC, 23 rue du Loess, 67037 Strasbourg (France); CNRS, UMR 7178, 67037 Strasbourg (France); Astier, A. [CSNSM, CNRS, IN2P3, Universite Paris-Sud, F-91405 Orsay (France); Atac, A. [Department of Physics, Faculty of Science, Ankara University, 06100 Tandogan, Ankara (Turkey); Department of Physics and Astronomy, Uppsala University, Uppsala (Sweden); Royal Institute of Technology, SE-10691 Stockholm (Sweden); Aubert, Y. [IPNO, CNRS/IN2P3, Universite Paris-Sud, F-91406 Orsay (France); Aufranc, C. [Universite de Lyon, Universite Lyon 1, CNRS-IN2P3, Institut de Physique Nucleaire de Lyon, F-69622 Villeurbanne (France); Austin, A. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Aydin, S. [INFN Sezione di Padova, IT-35131 Padova (Italy); Azaiez, F. [IPNO, CNRS/IN2P3, Universite Paris-Sud, F-91406 Orsay (France); Badoer, S. [INFN Laboratori Nazionali di Legnaro, IT-35020 Padova (Italy); Balabanski, D.L. [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia (Bulgaria); Barrientos, D. [IFIC, CSIC-Universitat de Valencia, E-46980 Paterna (Spain); and others

    2012-03-11

    The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation {gamma}-ray spectrometer. AGATA is based on the technique of {gamma}-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a {gamma} ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realisation of {gamma}-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterisation of the crystals was measured and compared with detector-response simulations. This enabled pulse-shape analysis algorithms, to extract energy, time and position, to be employed. In addition, tracking algorithms for event reconstruction were developed. The first phase of AGATA is now complete and operational in its first physics campaign. In the future AGATA will be moved between laboratories in Europe and operated in a series of campaigns to take advantage of the different beams and facilities available to maximise its science output. The paper reviews all the achievements made in the AGATA project including all the necessary infrastructure to operate and support the spectrometer.

  12. Handheld ultrasound array imaging device

    Science.gov (United States)

    Hwang, Juin-Jet; Quistgaard, Jens

    1999-06-01

    A handheld ultrasound imaging device, one that weighs less than five pounds, has been developed for diagnosing trauma in the combat battlefield as well as a variety of commercial mobile diagnostic applications. This handheld device consists of four component ASICs, each is designed using the state of the art microelectronics technologies. These ASICs are integrated with a convex array transducer to allow high quality imaging of soft tissues and blood flow in real time. The device is designed to be battery driven or ac powered with built-in image storage and cineloop playback capability. Design methodologies of a handheld device are fundamentally different to those of a cart-based system. As system architecture, signal and image processing algorithm as well as image control circuit and software in this device is deigned suitably for large-scale integration, the image performance of this device is designed to be adequate to the intent applications. To elongate the battery life, low power design rules and power management circuits are incorporated in the design of each component ASIC. The performance of the prototype device is currently being evaluated for various applications such as a primary image screening tool, fetal imaging in Obstetrics, foreign object detection and wound assessment for emergency care, etc.

  13. Redundant arrays of IDE drives

    Energy Technology Data Exchange (ETDEWEB)

    D.A. Sanders et al.

    2002-01-02

    The authors report tests of redundant arrays of IDE disk drives for use in offline high energy physics data analysis. Parts costs of total systems using commodity EIDE disks are now at the $4000 per Terabyte level. Disk storage prices have now decreased to the point where they equal the cost per Terabyte of Storage Technology tape silos. The disks, however, offer far better granularity; even small institutions can afford to deploy systems. The tests include reports on software RAID-5 systems running under Linux 2.4 using Promise Ultra 100{trademark} disk controllers. RAID-5 protects data in case of a single disk failure by providing parity bits. Tape backup is not required. Journaling file systems are used to allow rapid recovery from crashes. The data analysis strategy is to encapsulate data and CPU processing power. Analysis for a particular part of a data set takes place on the PC where the data resides. The network is only used to put results together. They explore three methods of moving data between sites; internet transfers, not pluggable IDE disks in FireWire cases, and DVD-R disks.

  14. Arrayed primer extension in the "array of arrays" format: a rational approach for microarray-based SNP genotyping

    DEFF Research Database (Denmark)

    Klitø, Niels G F; Tan, Qihua; Nyegaard, Mette

    2007-01-01

    This study provides a new version of the arrayed primer extension (APEX) protocol adapted to the 'array of arrays' platform using an instrumental setup for microarray processing not previously described. The primary aim of the study is to implement a system for rational cost-efficient genotyping...... where multiple singlenucleotide polymorphisms (SNPs) and individuals are genotyped on each microarray slide. Genotyping results are collected across 185 healthy Danish subjects and 76 SNPs on chromosome 3q13.31, because linkage to atopic disease phenotypes have been suggested in the Danish population...

  15. Geochemical Arrays at Woolsey Mound Seafloor Observatory

    Science.gov (United States)

    Sleeper, K.; Wilson, R. M.; Chanton, J.; Lapham, L.; Farr, N.; Camilli, R.; Martens, C. S.; Pontbriand, C.

    2011-12-01

    A suite of geochemical monitoring arrays has been developed for the Woolsey Mound Seafloor Observatory in the northern Gulf of Mexico to evaluate the oceanographic and tectonic forcing factors on the formation and stability of gas hydrates. These arrays are designed to collect sustained, time-series data of chemical concentrations, gradients and fluxes from the subsurface to the seafloor and into the near bottom water column. A Pore Fluid Array provides time-series measurements of methane, sulfate and salinity in subsurface pore waters to evaluate microbial activity, hydrate formation and/or hydrate dissociation. A Chimney Sampler Array collects in situ chemical and physical readings at the benthic boundary. The array is designed around a vertical cylinder with a known volume and washout rate for measuring chemical gradients and flux at the seafloor. The Benthic Boundary Layer Array extends into the water column with a package of sensors in a node close to the seafloor and a similar node 20 m above the seafloor to evaluate upward, downward and transversely advecting fluids. The three arrays can be used in concert to evaluate a release of methane by the dissociation of gas hydrates: the Pore Fluid Array identifies the breakdown of gas hydrates in the subsurface, the Chimney Array determines the rate of flux at the seafloor and the Benthic Boundary Layer Array evaluates the fate of the release in the water column. Combining the data from the geochemical arrays with output from the geophysical arrays provides key information to evaluate the specific and relative importance of tectonic and oceanographic triggers for hydrate dissociation. New probes and deployment platforms have been developed for the installation and maintenance of the arrays and new systems are in place and under development for the recovery of the data. Generally, the complete array or its components have to be recovered to download the data. However, this summer 2011, a new optic modem system was

  16. Tubular fluoropolymer arrays with high piezoelectric response

    Science.gov (United States)

    Zhukov, Sergey; Eder-Goy, Dagmar; Biethan, Corinna; Fedosov, Sergey; Xu, Bai-Xiang; von Seggern, Heinz

    2018-01-01

    Polymers with electrically charged internal air cavities called ferroelectrets exhibit a pronounced piezoelectric effect and are regarded as soft functional materials suitable for sensor and actuator applications. In this work, a simple method for fabricating piezoelectret arrays with open-tubular channels is introduced. A set of individual fluoroethylenepropylene (FEP) tubes is compressed between two heated metal plates. The squeezed FEP tubes are melted together at +270 °C. The resulting structure is a uniform, multi-tubular, flat array that reveals a strong piezoelectric response after a poling step. The fabricated arrays have a high ratio between piezoelectrically active and non-active areas. The optimal charging voltage and stability of the piezoelectric coefficients with pressures and frequency were experimentally investigated for two specific array structures with wall thickness of 50 and 120 μm. The array fabricated from 50 μm thick FEP tubes reveals a stable and high piezoelectric coefficient of {d}33 = 120-160 pC N-1 with a flat frequency response between 0.1 Hz and 10 kHz for pressures between 1 and 100 kPa. An increase of wall thickness to 120 μm is accompanied by a more than twofold decrease in the piezoelectric coefficient as a result of a simultaneously higher effective array stiffness and lower remanent polarization. The obtained experimental results can be used to optimize the array design with regard to the electromechanical performance.

  17. Large-scale nanophotonic phased array.

    Science.gov (United States)

    Sun, Jie; Timurdogan, Erman; Yaacobi, Ami; Hosseini, Ehsan Shah; Watts, Michael R

    2013-01-10

    Electromagnetic phased arrays at radio frequencies are well known and have enabled applications ranging from communications to radar, broadcasting and astronomy. The ability to generate arbitrary radiation patterns with large-scale phased arrays has long been pursued. Although it is extremely expensive and cumbersome to deploy large-scale radiofrequency phased arrays, optical phased arrays have a unique advantage in that the much shorter optical wavelength holds promise for large-scale integration. However, the short optical wavelength also imposes stringent requirements on fabrication. As a consequence, although optical phased arrays have been studied with various platforms and recently with chip-scale nanophotonics, all of the demonstrations so far are restricted to one-dimensional or small-scale two-dimensional arrays. Here we report the demonstration of a large-scale two-dimensional nanophotonic phased array (NPA), in which 64 × 64 (4,096) optical nanoantennas are densely integrated on a silicon chip within a footprint of 576 μm × 576 μm with all of the nanoantennas precisely balanced in power and aligned in phase to generate a designed, sophisticated radiation pattern in the far field. We also show that active phase tunability can be realized in the proposed NPA by demonstrating dynamic beam steering and shaping with an 8 × 8 array. This work demonstrates that a robust design, together with state-of-the-art complementary metal-oxide-semiconductor technology, allows large-scale NPAs to be implemented on compact and inexpensive nanophotonic chips. In turn, this enables arbitrary radiation pattern generation using NPAs and therefore extends the functionalities of phased arrays beyond conventional beam focusing and steering, opening up possibilities for large-scale deployment in applications such as communication, laser detection and ranging, three-dimensional holography and biomedical sciences, to name just a few.

  18. Performance Analysis of Digital loudspeaker Arrays

    DEFF Research Database (Denmark)

    Pedersen, Bo Rohde; Kontomichos, Fotios; Mourjopoulos, John

    2008-01-01

    An analysis of digital loudspeaker arrays shows that the ways in which bits are mapped to the drivers influence the quality of the audio result. Specifically, a "bit-summed" rather than the traditional "bit-mapped" strategy greatly reduces the number of times drivers make binary transitions per...... period of the input frequency. Detailed simulations compare the results for a 32-loudspeaker array with a similar configuration with analog excitation of the drivers. Ideally, drivers in digital arrays should be very small and span a small area, but that sets limits on the low-frequency response...

  19. Arrays: The Heart and Soul of SIRTIF

    Science.gov (United States)

    Werner, Michael W.; Eisenhardt, Peter R.

    1993-01-01

    This paper describes the status of NASA's Space Infrared Telescope Facility (SIRTF) program. SIRTF will be a cryogenically cooled observatory for infrared astronomy from space and is planned for launch early in the next decade. It will be the first cryogenic observatory to make extensive use of the powerful infrared detector array technology discussed at this conference. We summarize a newly developed SIRTF mission concept and show how the availability of detector arrays has shaped the scientific rationale for SIRTF, and how the arrays themselves have become part of the definition of the SIRTF mission.

  20. Arrays: The heart and soul of SIRTF

    Science.gov (United States)

    Werner, Michael W.; Eisenhardt, Peter R.

    1994-01-01

    This pape describes the status of NASA's Space Infrared Telescope Facility (SIRTF) program. SIRTF will be a cryogenically cooled observatory for infrared astronomy from space and is planned for launch early in the next decade. It will be the first cryogenic space observatory to make extensive use of the powerful infrared detector array technology discussed at this conference. We summarize a newly developed SIRTF mission concept and show how the availability of detector arrays has shaped the scientific rationale for SIRTF, and how the arrays themselves have become part of the definition of the SIRTF mission.

  1. Flat-plate photovoltaic array design optimization

    Science.gov (United States)

    Ross, R. G., Jr.

    1980-01-01

    An analysis is presented which integrates the results of specific studies in the areas of photovoltaic structural design optimization, optimization of array series/parallel circuit design, thermal design optimization, and optimization of environmental protection features. The analysis is based on minimizing the total photovoltaic system life-cycle energy cost including repair and replacement of failed cells and modules. This approach is shown to be a useful technique for array optimization, particularly when time-dependent parameters such as array degradation and maintenance are involved.

  2. Fluid jet-array parallel machining of optical microstructure array surfaces.

    Science.gov (United States)

    Wang, Chunjin; Cheung, Chi Fai; Liu, Mingyu; Lee, Wing Bun

    2017-09-18

    Optical microstructure array surfaces such as micro-lens array surface, micro-groove array surface etc., are being used in more and more optical products, depending on its ability to produce a unique or particular performance. The geometrical complexity of the optical microstructures array surfaces makes them difficult to be fabricated. In this paper, a novel method named fluid jet-array parallel machining (FJAPM) is proposed to provide a new way to generate the microstructure array surfaces with high productivity. In this process, an array of abrasive water jets is pumped out of a nozzle, and each fluid jet simultaneously impinges the target surface to implement material removal independently. The jet-array nozzle was optimally designed firstly to diminish the effect of jet interference based on the experimental investigation on the 2-Jet nozzles with different jet intervals. The material removal and surface generation models were built and validated through the comparison of simulation and experimental results of the generation of several kinds of microstructure array surfaces. Following that, the effect of some factors in the process was discussed, including the fluid pressure, nozzle geometry, tool path, and dwell time. The experimental results and analysis prove that FJAPM process is an effective way to fabricate the optical microstructure array surface together with high productivity.

  3. Conformal array design on arbitrary polygon surface with transformation optics

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Li, E-mail: dengl@bupt.edu.cn; Hong, Weijun, E-mail: hongwj@bupt.edu.cn; Zhu, Jianfeng; Peng, Biao; Li, Shufang [Beijing Key Laboratory of Network System Architecture and Convergence, School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, 100876 Beijing (China); Wu, Yongle, E-mail: wuyongle138@gmail.com [Beijing Key Laboratory of Work Safety Intelligent Monitoring, School of Electronic Engineering, Beijing University of Posts and Telecommunications, 100876 Beijing (China)

    2016-06-15

    A transformation-optics based method to design a conformal antenna array on an arbitrary polygon surface is proposed and demonstrated in this paper. This conformal antenna array can be adjusted to behave equivalently as a uniformly spaced linear array by applying an appropriate transformation medium. An typical example of general arbitrary polygon conformal arrays, not limited to circular array, is presented, verifying the proposed approach. In summary, the novel arbitrary polygon surface conformal array can be utilized in array synthesis and beam-forming, maintaining all benefits of linear array.

  4. ISPA (imaging silicon pixel array) experiment

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    Application components of ISPA tubes are shown: the CERN-developed anode chip, special windows for gamma and x-ray detection, scintillating crystal and fibre arrays for imaging and tracking of ionizing particles.

  5. Fiber Optic Pressure Sensor Array, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — VIP Sensors proposes to develop a Fiber Optic Pressure Sensor Array for measuring air flow pressure at multiple points on the skin of aircrafts for Flight Load Test...

  6. Marine Attack on Towed Hydrophone Arrays

    National Research Council Canada - National Science Library

    Kalmijn, Ad

    2002-01-01

    The original objective of the SIO Marine Attack project was to identify the electric and magnetic fields causing sharks to inflict serious damage upon the towed hydrophone arrays of US Navy submarines...

  7. Spacecraft Multiple Array Communication System Performance Analysis

    Science.gov (United States)

    Hwu, Shian U.; Desilva, Kanishka; Sham, Catherine C.

    2010-01-01

    The Communication Systems Simulation Laboratory (CSSL) at the NASA Johnson Space Center is tasked to perform spacecraft and ground network communication system simulations, design validation, and performance verification. The CSSL has developed simulation tools that model spacecraft communication systems and the space and ground environment in which the tools operate. In this paper, a spacecraft communication system with multiple arrays is simulated. Multiple array combined technique is used to increase the radio frequency coverage and data rate performance. The technique is to achieve phase coherence among the phased arrays to combine the signals at the targeting receiver constructively. There are many technical challenges in spacecraft integration with a high transmit power communication system. The array combining technique can improve the communication system data rate and coverage performances without increasing the system transmit power requirements. Example simulation results indicate significant performance improvement can be achieved with phase coherence implementation.

  8. Mid-Frequency Source Array Engineering Salaries

    National Research Council Canada - National Science Library

    Hodgkiss, William

    2003-01-01

    ... (time reversal "mirror") concepts. The source-receive array and its companion surface buoy operate in an autonomous fashion thus facilitating single ship operations for carrying out experimental work...

  9. Self-Deploying Tent Array, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Self-Deploying Tent Array (SDTA) is a modular power system that can be scaled to very large power levels for use on the Martian surface. The tent shape is...

  10. Strain Actuated Solar Arrays (SASA), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The team of CU Aerospace and the University of Illinois at Urbana-Champaign propose multifunctional solar arrays, which can be used for attitude control of a...

  11. Digital Array Gas Radiometer (DAGR) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation proposed here is a digital array gas radiometer (DAGR), a new design for a gas filter correlation radiometer (GFCR) to accurately measure and monitor...

  12. Radiation Hardened Bolometer Linear Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has developed space-based thermal instrument spectrometers based on thermopile detectors linear arrays that are intrinsically radiation hard. Micro-bolometers...

  13. Statistical monitoring of linear antenna arrays

    KAUST Repository

    Harrou, Fouzi

    2016-11-03

    The paper concerns the problem of monitoring linear antenna arrays using the generalized likelihood ratio (GLR) test. When an abnormal event (fault) affects an array of antenna elements, the radiation pattern changes and significant deviation from the desired design performance specifications can resulted. In this paper, the detection of faults is addressed from a statistical point of view as a fault detection problem. Specifically, a statistical method rested on the GLR principle is used to detect potential faults in linear arrays. To assess the strength of the GLR-based monitoring scheme, three case studies involving different types of faults were performed. Simulation results clearly shown the effectiveness of the GLR-based fault-detection method to monitor the performance of linear antenna arrays.

  14. Study and Design of Differential Microphone Arrays

    CERN Document Server

    Benesty, Jacob

    2013-01-01

    Microphone arrays have attracted a lot of interest over the last few decades since they have the potential to solve many important problems such as noise reduction/speech enhancement, source separation, dereverberation, spatial sound recording, and source localization/tracking, to name a few. However, the design and implementation of microphone arrays with beamforming algorithms is not a trivial task when it comes to processing broadband signals such as speech. Indeed, in most sensor arrangements, the beamformer tends to have a frequency-dependent response. One exception, perhaps, is the family of differential microphone arrays (DMAs) that have the promise to form frequency-independent responses. Moreover, they have the potential to attain high directional gains with small and compact apertures. As a result, this type of microphone arrays has drawn much research and development attention recently. This book is intended to provide a systematic study of DMAs from a signal processing perspective. The primary obj...

  15. Array Processing for Radar: Achievements and Challenges

    Directory of Open Access Journals (Sweden)

    Ulrich Nickel

    2013-01-01

    Full Text Available Array processing for radar is well established in the literature, but only few of these algorithms have been implemented in real systems. The reason may be that the impact of these algorithms on the overall system must be well understood. For a successful implementation of array processing methods exploiting the full potential, the desired radar task has to be considered and all processing necessary for this task has to be eventually adapted. In this tutorial paper, we point out several viewpoints which are relevant in this context: the restrictions and the potential provided by different array configurations, the predictability of the transmission function of the array, the constraints for adaptive beamforming, the inclusion of monopulse, detection and tracking into the adaptive beamforming concept, and the assessment of superresolution methods with respect to their application in a radar system. The problems and achieved results are illustrated by examples from previous publications.

  16. Monolithic Time Delay Integrated APD Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall goal of the proposed program by Epitaxial Technologies is to develop monolithic time delay integrated avalanche photodiode (APD) arrays with sensitivity...

  17. Thin Flexible IMM Solar Array, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Thin, flexible, and highly efficient solar arrays are needed that package compactly for launch and deploy into large, structurally stable high power generators....

  18. Integrated Spatial Filter Array, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — To address the NASA Earth Science Division need for spatial filter arrays for amplitude and wavefront control, Luminit proposes to develop a novel Integrated Spatial...

  19. Stretched Lens Array Photovoltaic Concentrator Technology Developed

    Science.gov (United States)

    Piszczor, Michael F., Jr.; O'Neill, Mark J.

    2004-01-01

    Solar arrays have been and continue to be the mainstay in providing power to nearly all commercial and government spacecraft. Light from the Sun is directly converted into electrical energy using solar cells. One way to reduce the cost of future space power systems is by minimizing the size and number of expensive solar cells by focusing the sunlight onto smaller cells using concentrator optics. The stretched lens array (SLA) is a unique concept that uses arched Fresnel lens concentrators to focus sunlight onto a line of high-efficiency solar cells located directly beneath. The SLA concept is based on the Solar Concentrator Array with Refractive Linear Element Technology (SCARLET) design that was used on NASA's New Millennium Deep Space 1 mission. The highly successful asteroid/comet rendezvous mission (1998 to 2001) demonstrated the performance and long-term durability of the SCARLET/SLA solar array design and set the foundation for further improvements to optimize its performance.

  20. Spatiotemporal light localization in infiltrated waveguide arrays

    DEFF Research Database (Denmark)

    Rasmussen, Per Dalgaard; Neshev, D.N-; Sukhorukov, A.A.

    2008-01-01

    We study light propagation in hexagonal waveguide arrays and show that simultaneous spatiotemporal localisation is possible by combination of engineered anomalous dispersion through selective excitation of Bloch-modes and spatial confinement in a nonlinear defect mode....

  1. Ferrite LTCC based phased array antennas

    KAUST Repository

    Ghaffar, Farhan A.

    2016-11-02

    Two phased array antennas realized in multilayer ferrite LTCC technology are presented in this paper. The use of embedded bias windings in these designs allows the negation of external magnets which are conventionally employed with bulk ferrite medium. This reduces the required magnetostatic field strength by 90% as compared to the traditional designs. The phase shifters are implemented using the SIW technology. One of the designs is operated in the half mode waveguide topology while the other design is based on standard full mode waveguide operation. The two phase shifter designs are integrated with two element patch antenna array and slotted SIW array respectively. The array designs demonstrate a beam steering of 30° and ±19° respectively for a current excitation of 200 mA. The designs, due to their small factor can be easily integrated in modern communication systems which is not possible in the case of bulk ferrite based designs.

  2. Density controlled carbon nanotube array electrodes

    Science.gov (United States)

    Ren, Zhifeng F [Newton, MA; Tu, Yi [Belmont, MA

    2008-12-16

    CNT materials comprising aligned carbon nanotubes (CNTs) with pre-determined site densities, catalyst substrate materials for obtaining them and methods for forming aligned CNTs with controllable densities on such catalyst substrate materials are described. The fabrication of films comprising site-density controlled vertically aligned CNT arrays of the invention with variable field emission characteristics, whereby the field emission properties of the films are controlled by independently varying the length of CNTs in the aligned array within the film or by independently varying inter-tubule spacing of the CNTs within the array (site density) are disclosed. The fabrication of microelectrode arrays (MEAs) formed utilizing the carbon nanotube material of the invention is also described.

  3. Fiber Optic Pressure Sensor Array, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — VIP Sensors proposes to develop a Fiber Optic Pressure Sensor Array System for measuring air flow pressure at multiple points on the skin of aircrafts for Flight...

  4. SMEX-Lite Modular Solar Array Architecture

    Science.gov (United States)

    Lyons, John

    2002-01-01

    For the most part, Goddard solar arrays have been custom designs that are unique to each mission. The solar panel design has been frozen prior to issuing an RFP for their procurement. There has typically been 6-9 months between RFP release and contract award, followed by an additional 24 months for performance of the contract. For Small Explorer (SMEX) missions, with three years between mission definition and launch, this has been a significant problem. The SMEX solar panels have been sufficiently small that the contract performance period has been reduced to 12-15 months. The bulk of this time is used up in the final design definition and fabrication of flight solar cell assemblies. Even so, it has been virtually impossible to have the spacecraft design at a level of maturity sufficient to freeze the solar panel geometry and release the RFP in time to avoid schedule problems with integrating the solar panels to the spacecraft. With that in mind, the SMEX-Lite project team developed a modular architecture for the assembly of solar arrays to greatly reduce the cost and schedule associated with the development of a mission- specific solar array. In the modular architecture, solar cells are fabricated onto small substrate panels. This modular panel (approximately 8.5" x 17" in this case) becomes the building block for constructing solar arrays for multiple missions with varying power requirements and geometrical arrangements. The mechanical framework that holds these modules together as a solar array is the only mission-unique design, changing in size and shape as required for each mission. There are several advantages to this approach. First, the typical solar array development cycle requires a mission unique design, procurement, and qualification including a custom qualification panel. With the modular architecture, a single qualification of the SMEX-Lite modules and the associated mechanical framework in a typical configuration provided a qualification by

  5. Digital Array Gas Radiometer (DAGR) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The digital array gas radiometer (DAGR) is a new sensor design for accurate measurement and monitoring of trace gases in the boundary layer from space, aircraft, or...

  6. Transition edge sensor series array bolometer

    International Nuclear Information System (INIS)

    Beyer, J

    2010-01-01

    A transition edge sensor series array (TES-SA) is an array of identical TESs that are connected in series by low-inductance superconducting wiring. The array elements are equally and well thermally coupled to the absorber and respond to changes in the absorber temperature in synchronization. The TES-SA total resistance increases compared to a single TES while the shape of the superconducting transition is preserved. We are developing a TES-SA with a large number, hundreds to thousands, of array elements with the goal of enabling the readout of a TES-based bolometer operated at 4.2 K with a semiconductor-based amplifier located at room temperature. The noise and dynamic performance of a TES-SA bolometer based on a niobium/aluminum bilayer is analyzed. It is shown that stable readout of the bolometer with a low-noise transimpedance amplifier is feasible.

  7. Applications of the phased array technique

    International Nuclear Information System (INIS)

    Erhard, A.; Schenk, G.; Hauser, Th.; Voelz, U.

    1999-01-01

    The application of the phased array technique was limited to heavy and thick wall components as present in the nuclear industry. With the improvement of the equipment and probes other application areas are now open for the phased array technique, e.g. the inspection of the turbine blade root, weld inspection in a wall thickness range between 12 and 40 mm, inspection of aircraft components, inspection of spot welds or inspection of concretes. The aim of the use of phased array techniques has not been changed related to the first applications, i.e. the adaptation of the sound beam to the geometry by steering the angel of incidence or the skewing angle as well as the focussing of sound fields. Due to the fact, that the new applications of the phased array techniques in some cases don't leave the laboratories for the time being, the examples of this contribution will focus applications with practical background. (orig.)

  8. CubeSat Modular Deployable Solar Arrays

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced CubeSat missions have demanding power requirements relative to their limited available surface area that drive the need for deployable solar arrays. Vendors...

  9. NASA Solar Array Demonstrates Commercial Potential

    Science.gov (United States)

    Creech, Gray

    2006-01-01

    A state-of-the-art solar-panel array demonstration site at NASA's Dryden Flight Research Center provides a unique opportunity for studying the latest in high-efficiency solar photovoltaic cells. This five-kilowatt solar-array site (see Figure 1) is a technology-transfer and commercialization success for NASA. Among the solar cells at this site are cells of a type that was developed in Dryden Flight Research Center s Environmental Research Aircraft and Sensor Technology (ERAST) program for use in NASA s Helios solar-powered airplane. This cell type, now denoted as A-300, has since been transferred to SunPower Corporation of Sunnyvale, California, enabling mass production of the cells for the commercial market. High efficiency separates these advanced cells from typical previously commercially available solar cells: Whereas typical previously commercially available cells are 12 to 15 percent efficient at converting sunlight to electricity, these advanced cells exhibit efficiencies approaching 23 percent. The increase in efficiency is due largely to the routing of electrical connections behind the cells (see Figure 2). This approach to increasing efficiency originated as a solution to the problem of maximizing the degree of utilization of the limited space available atop the wing of the Helios airplane. In retrospect, the solar cells in use at this site could be used on Helios, but the best cells otherwise commercially available could not be so used, because of their lower efficiencies. Historically, solar cells have been fabricated by use of methods that are common in the semiconductor industry. One of these methods includes the use of photolithography to define the rear electrical-contact features - diffusions, contact openings, and fingers. SunPower uses these methods to produce the advanced cells. To reduce fabrication costs, SunPower continues to explore new methods to define the rear electrical-contact features. The equipment at the demonstration site includes

  10. Frequency Domain Electromagnetic Sensor Array Development

    Science.gov (United States)

    2007-09-17

    undergone limited bench testing. The design is based on the GEM-3 active primary field cancellation technology, which creates a "magnetic cavity" for...responses at three receiver locations. ............................................... 13 Figure 16. Warmup drift for the GEM-3 array at the Tx2-2... engineering details for application to single sensor and towed array configurations have been worked out in ESTCP projects MM-0208, -0414 and - 0531

  11. Miniaturized Retrodirective Arrays for a Nanosatellite Platform

    Science.gov (United States)

    2012-01-01

    Miniaturized Retrodirective Arrays for a Nanosatellite Platform NIA Sb. GRANT NUMBER N00014-1 0-1-0056 Sc. PROGRAM ELEMENT NUMBER . NIA 6. AUTHOR(S) Sd...into a mobile platfonn, such as a nanosatellite , presents unique challenges due to the platform’s restrictions in terms of size, weight, and power...of power detection and null scanning. 1S. SUBJECT TERMS Retrodirective Array, Nanosatellite 16. SECURITY CLASSIFICATION OF: a. REPORT b. ABSTRACT

  12. What Else Is Decidable about Integer Arrays?

    OpenAIRE

    Habermehl, Peter; Iosif, Radu; Vojnar, Tomáš

    2008-01-01

    International audience; We introduce a new decidable logic for reasoning about infinite arrays of integers. The logic is in the ∃ * ∀ * first-order fragment and allows (1) Presburger constraints on existentially quantified variables, (2) difference constraints as well as periodicity constraints on universally quantified indices, and (3) difference constraints on values. In particular, using our logic, one can express constraints on consecutive elements of arrays (e.g. ∀i. 0 ≤ i < n → a[i + 1]...

  13. High Efficiency mm-Wave Transmitter Array

    Science.gov (United States)

    2016-09-01

    Research Triangle Park, NC 27709-2211 Mm-waves. power amplifiers, Si integrated circuits, antenna arrays REPORT DOCUMENTATION PAGE 11. SPONSOR...Array Report Title High efficiency, high power transmitters integrated in silicon at 45, 94 and 138 GHz were developed. Our approach employs CMOS-SOI...based power amplifiers had a variety of advantages over nMOS PAs. Advancements have been reported in detail in numerous publications (13 journal

  14. Thermophotovoltaic Arrays for Electrical Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Sarnoff Corporation

    2003-11-18

    Sarnoff has designed an integrated array of thermophotovoltaic (TPV) cells based on the In(Al)GaAsSb/GaSb materials system. These arrays will be used in a system to generate electrical power from a radioisotope heat source that radiates at temperatures from 700 to 1000 C. Two arrays sandwich the slab heat source and will be connected in series to build voltage. Between the arrays and the heat source is a spectral control filter that transmits above-bandgap radiation and reflects below-bandgap radiation. The goal is to generate 5 mW of electrical power at 3 V from a 700 C radiant source. Sarnoff is a leader in antimonide-based TPV cell development. InGaAsSb cells with a bandgap of 0.53 eV have operated at system conversion efficiencies greater than 17%. The system included a front-surface filter, and a 905 C radiation source. The cells were grown via organo-metallic vapor-phase epitaxy. Sarnoff will bring this experience to bear on the proposed project. The authors first describe array and cell architecture. They then present calculated results showing that about 80 mW of power can be obtained from a 700 C radiator. Using a conservative array design, a 5-V output is possible.

  15. 2D array based on fermat spiral

    Science.gov (United States)

    Martínez, O.; Martín, C. J.; Godoy, G.; Ullate, L. G.

    2010-01-01

    The main challenge faced by 3D ultrasonic imaging with 2D array transducer is the large number of elements required to achieve an acceptable level of quality in the images. Therefore, the optimization of the array layout to reduce the number of active elements in the aperture has been a research topic in the last years. Nowadays, CMUT array technology has made viable the production of 2D arrays with larger flexibility on elements size, shape and position. This is opening new options in 2D array design, allowing to revise as viable alternatives others layouts that had been studied in the past, like circular and Archimedes spiral layout. In this work the problem of designing an imaging system array with a diameter of 60 λ and a limited number of elements using the Fermat spiral layout has been studied. This study has been done for two different numbers of electronic channels (N = 128 and N = 256). As summary, a general discussion of the results and the most interesting cases are presented.

  16. Tunable nanoparticle arrays at charged interfaces.

    Science.gov (United States)

    Srivastava, Sunita; Nykypanchuk, Dmytro; Fukuto, Masafumi; Gang, Oleg

    2014-10-28

    Structurally tunable two-dimensional (2D) arrays of nanoscale objects are important for modulating functional responses of thin films. We demonstrate that such tunable and ordered nanoparticles (NP) arrays can be assembled at charged air-water interfaces from nanoparticles coated with polyelectrolyte chains, DNA. The electrostatic attraction between the negatively charged nonhybridizing DNA-coated gold NPs and a positively charged lipid layer at the interface facilitates the formation of a 2D hexagonally closed packed (HCP) nanoparticle lattice. We observed about 4-fold change of the monolayer nanoparticle density by varying the ionic strength of the subphase. The tunable NP arrays retain their structure reasonably well when transferred to a solid support. The influence of particle's DNA corona and lipid layer composition on the salt-induced in-plane and normal structural evolution of NP arrays was studied in detail using a combination of synchrotron-based in situ surface scattering methods, grazing incidence X-ray scattering (GISAXS), and X-ray reflectivity (XRR). Comparative analysis of the interparticle distances as a function of ionic strength reveals the difference between the studied 2D nanoparticle arrays and analogous bulk polyelectrolyte star polymers systems, typically described by Daoud-Cotton model and power law scaling. The observed behavior of the 2D nanoparticle array manifests a nonuniform deformation of the nanoparticle DNA corona due to its electrostatically induced confinement at the lipid interface. The present study provides insight on the interfacial properties of the NPs coated with charged soft shells.

  17. Terahertz Array Receivers with Integrated Antennas

    Science.gov (United States)

    Chattopadhyay, Goutam; Llombart, Nuria; Lee, Choonsup; Jung, Cecile; Lin, Robert; Cooper, Ken B.; Reck, Theodore; Siles, Jose; Schlecht, Erich; Peralta, Alessandro; hide

    2011-01-01

    Highly sensitive terahertz heterodyne receivers have been mostly single-pixel. However, now there is a real need of multi-pixel array receivers at these frequencies driven by the science and instrument requirements. In this paper we explore various receiver font-end and antenna architectures for use in multi-pixel integrated arrays at terahertz frequencies. Development of wafer-level integrated terahertz receiver front-end by using advanced semiconductor fabrication technologies has progressed very well over the past few years. Novel stacking of micro-machined silicon wafers which allows for the 3-dimensional integration of various terahertz receiver components in extremely small packages has made it possible to design multi-pixel heterodyne arrays. One of the critical technologies to achieve fully integrated system is the antenna arrays compatible with the receiver array architecture. In this paper we explore different receiver and antenna architectures for multi-pixel heterodyne and direct detector arrays for various applications such as multi-pixel high resolution spectrometer and imaging radar at terahertz frequencies.

  18. Si Wire-Array Solar Cells

    Science.gov (United States)

    Boettcher, Shannon

    2010-03-01

    Micron-scale Si wire arrays are three-dimensional photovoltaic absorbers that enable orthogonalization of light absorption and carrier collection and hence allow for the utilization of relatively impure Si in efficient solar cell designs. The wire arrays are grown by a vapor-liquid-solid-catalyzed process on a crystalline (111) Si wafer lithographically patterned with an array of metal catalyst particles. Following growth, such arrays can be embedded in polymethyldisiloxane (PDMS) and then peeled from the template growth substrate. The result is an unusual photovoltaic material: a flexible, bendable, wafer-thickness crystalline Si absorber. In this paper I will describe: 1. the growth of high-quality Si wires with controllable doping and the evaluation of their photovoltaic energy-conversion performance using a test electrolyte that forms a rectifying conformal semiconductor-liquid contact 2. the observation of enhanced absorption in wire arrays exceeding the conventional light trapping limits for planar Si cells of equivalent material thickness and 3. single-wire and large-area solid-state Si wire-array solar cell results obtained to date with directions for future cell designs based on optical and device physics. In collaboration with Michael Kelzenberg, Morgan Putnam, Joshua Spurgeon, Daniel Turner-Evans, Emily Warren, Nathan Lewis, and Harry Atwater, California Institute of Technology.

  19. Aspects of the Subarrayed Array Processing for the Phased Array Radar

    Directory of Open Access Journals (Sweden)

    Hang Hu

    2015-01-01

    Full Text Available This paper gives an overview on the research status, developments, and achievements of subarrayed array processing for the multifunction phased array radar. We address some issues concerning subarrayed adaptive beamforming, subarrayed fast-time space-time adaptive processing, subarray-based sidelobe reduction of sum and difference beam, subarrayed adapted monopulse, subarrayed superresolution direction finding, subarray configuration optimization in ECCM (electronic counter-countermeasure, and subarrayed array processing for MIMO-PAR. In this review, several viewpoints relevant to subarrayed array processing are pointed out and the achieved results are demonstrated by numerical examples.

  20. In situ investigation of the surface silvering of late Roman coins by combined use of high energy broad-beam and low energy micro-beam X-ray fluorescence techniques

    International Nuclear Information System (INIS)

    Romano, F.P.; Garraffo, S.; Pappalardo, L.; Rizzo, F.

    2012-01-01

    The compositional analysis of archeological metals performed with the X-ray Fluorescence technique (XRF) provides information on the ancient technology. One of the most interesting case-study concerns the techniques used by Romans for silvering the surface of coins. Different metallurgical processes have been suggested in previous studies. Recently the investigation has been addressed to the mercury-silvering and to its possible use in the mass-production of coins minted during the late period (after 294 AD). In the present paper the non-destructive investigation of the silvering process used for manufacturing the Roman nummi – the important typology of coin introduced by Diocletian in his monetary reform – is approached by the combined use of the standard X-Ray Fluorescence (XRF) and the low energy micro-X-Ray Fluorescence (LE-μXRF) portable methods. The research was focused on the systematic determination of the mercury presence in a large number of samples and on its correlation with silver in the surface of the coins. 1041 Roman nummi belonging to the Misurata Treasure were analyzed in situ, at the Leptis Magna Museum (Al Khums, Libya). The treasure, composed of about 108 thousand silvered coins, gives the unique opportunity to study the Roman coinage in a wide interval of time (about 40 years in the period 294–333 AD) and in almost all the imperial mints operating in the Roman world. - Highlights: ► Custom-building of a high energy broad-beam and a low energy micro-beam XRF ► In situ analysis of the silvering methods in late Roman nummi with plated surfaces ► The broad-beam XRF was applied for the detection of mercury traces in the coin alloy. ► The low energy micro-XRF was used to scan the surface patina of the coins. ► The correlation between mercury and silver at the coin surface was evidenced.