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Sample records for subject headings electromagnetics

  1. Effects of radiation emitted by WCDMA mobile phones on electromagnetic hypersensitive subjects

    Directory of Open Access Journals (Sweden)

    Kwon Min Kyung

    2012-09-01

    Full Text Available Abstract Background With the use of the third generation (3 G mobile phones on the rise, social concerns have arisen concerning the possible health effects of radio frequency-electromagnetic fields (RF-EMFs emitted by wideband code division multiple access (WCDMA mobile phones in humans. The number of people with self-reported electromagnetic hypersensitivity (EHS, who complain of various subjective symptoms such as headache, dizziness and fatigue, has also increased. However, the origins of EHS remain unclear. Methods In this double-blind study, two volunteer groups of 17 EHS and 20 non-EHS subjects were simultaneously investigated for physiological changes (heart rate, heart rate variability, and respiration rate, eight subjective symptoms, and perception of RF-EMFs during real and sham exposure sessions. Experiments were conducted using a dummy phone containing a WCDMA module (average power, 24 dBm at 1950 MHz; specific absorption rate, 1.57 W/kg within a headset placed on the head for 32 min. Results WCDMA RF-EMFs generated no physiological changes or subjective symptoms in either group. There was no evidence that EHS subjects perceived RF-EMFs better than non-EHS subjects. Conclusions Considering the analyzed physiological data, the subjective symptoms surveyed, and the percentages of those who believed they were being exposed, 32 min of RF radiation emitted by WCDMA mobile phones demonstrated no effects in either EHS or non-EHS subjects.

  2. Using Topic Models to Interpret MEDLINE's Medical Subject Headings

    Science.gov (United States)

    Newman, David; Karimi, Sarvnaz; Cavedon, Lawrence

    We consider the task of interpreting and understanding a taxonomy of classification terms applied to documents in a collection. In particular, we show how unsupervised topic models are useful for interpreting and understanding MeSH, the Medical Subject Headings applied to articles in MEDLINE. We introduce the resampled author model, which captures some of the advantages of both the topic model and the author-topic model. We demonstrate how topic models complement and add to the information conveyed in a traditional listing and description of a subject heading hierarchy.

  3. METHODICAL ENSURING ELECTRONIC SUBJECT ANALYSIS OF DOCUMENTS: FEATURES OF EDITING SUBJECT HEADINGS IN ABIS ABSOTHEQUE UNICODE

    Directory of Open Access Journals (Sweden)

    Т. М. Бикова

    2016-03-01

    Full Text Available The purpose of our article is consideration of questions of electronic subject analysis of documents and methodical ensuring editing subject headings in the electronic catalog. The main objective of our article – to show a technique of editing the dictionary of subject headings, to study and apply this technique in work of libraries of higher education institutions. Object of research is the thesaurus of subject headings of the electronic catalog of the Scientific Library of Odessa I. I. Mechnikov National University. To improve the efficiency and quality of the search capabilities of the electronic catalog needs constant work on its optimization, that is, technical editing of subject headings, the opening of new subject headings and subheadings.  In Scientific library the instruction, which regulates a technique of edition of subject headings, was developed and put into practice and establishes rationing of this process. The main finding of the work should be to improve the level of bibliographic service users and rationalization systematizer. The research findings have the practical value for employees of libraries.

  4. User's guide to Sears List of subject headings

    CERN Document Server

    Satija, Mohinder P

    2008-01-01

    This book is a companion to the 19th edition of the Sears List and a complete course in the theory and practice of the List for practitioners, teachers, and learners. The object of this small, practical introduction is to be simple, clear, and illustrative, assuming the reader has little prior knowledge either of the Sears List or of subject headings work in general.

  5. Developing a biomedical expert finding system using medical subject headings.

    Science.gov (United States)

    Singh, Harpreet; Singh, Reema; Malhotra, Arjun; Kaur, Manjit

    2013-12-01

    Efficient identification of subject experts or expert communities is vital for the growth of any organization. Most of the available expert finding systems are based on self-nomination, which can be biased, and are unable to rank experts. Thus, the objective of this work was to develop a robust and unbiased expert finding system which can quantitatively measure expertise. Medical Subject Headings (MeSH) is a controlled vocabulary developed by the National Library of Medicine (NLM) for indexing research publications, articles and books. Using the MeSH terms associated with peer-reviewed articles published from India and indexed in PubMed, we developed a Web-based program which can be used to identify subject experts and subjects associated with an expert. We have extensively tested our system to identify experts from India in various subjects. The system provides a ranked list of experts where known experts rank at the top of the list. The system is general; since it uses information available with the PubMed, it can be implemented for any country. The expert finding system is able to successfully identify subject experts in India. Our system is unique because it allows the quantification of subject expertise, thus enabling the ranking of experts. Our system is based on peer-reviewed information. Use of MeSH terms as subjects has standardized the subject terminology. The system matches requirements of an ideal expert finding system.

  6. Estimation of Aircraft Attitude/Heading Based on the Polarization of Electromagnetic Waves

    Directory of Open Access Journals (Sweden)

    Sun Hong-mei

    2013-12-01

    Full Text Available This paper illustrates the full use of an orthogonal decoupling signal model to describe the 3-D construction of polarized electromagnetic waves. The maximum likelihood method and MUSIC algorithm were introduced into the parameter estimation of partially polarized waves. Attitude reference information for an aircraft that was calibrated by an information base station was delivered by polarized electromagnetic waves. Through receiving and processing the information of the aircraft, a single electromagnetic vector sensor can acquire the aircraft attitude in a geographic coordinate system. Differing from the triangle calculation method which relies on a multi-point measurement, the proposed method only needs a base station signal and a single receiver on the motion platform to realize the posture perception of aircraft. It can therefore serve as a substitute for aircraft attitude navigation and aircraft heading navigation. The introduction of the motion platform attitude estimation algorithm provides a technology support for engineering applications.

  7. Subject Headings for Church or Synagogue Libraries. 2nd Revised Edition. CSLA Guide No. 8.

    Science.gov (United States)

    Kersten, Dorothy B.

    This guide to subject headings for church or synagogue libraries begins by providing guidelines for the subject cataloging process. These guidelines are presented under seven headings: (1) Selecting the Subject Heading (by names of persons, religious congregations and orders, sects and denominations, places, holidays, and new subjects); (2)…

  8. CINAHL list of subject headings: a nursing thesaurus revised.

    Science.gov (United States)

    Fishel, C C; Graham, K E; Greer, D M; Gupta, A D; Lockwood, D K; Prime, E E

    1985-04-01

    The rationale and methods for revising the thesaurus of one of the major health sciences indexing tools are discussed. Computer production of the Cumulative Index to Nursing & Allied Health Literature and the possibility of online access mandated a revision of the list of subject headings. CINAHL has maintained a policy of responding to user needs and to changes in the nursing and allied health literature, and user input was encouraged during revision of the thesaurus. The methods of structural revision are described, and major changes in the thesaurus are detailed. Modification of the thesaurus is expected to have a far-reaching impact on the retrieval of information in nursing and allied health. Nursing and Allied Health (CINAHL) is now available online through DIALOG (file 218) and BRS (access code NAHL).

  9. Effects of radiation emitted by WCDMA mobile phones on electromagnetic hypersensitive subjects

    OpenAIRE

    Kwon, Min Kyung; Choi, Joon Yul; Kim, Sung Kean; Yoo, Tae Keun; Kim, Deok Won

    2012-01-01

    Abstract Background With the use of the third generation (3 G) mobile phones on the rise, social concerns have arisen concerning the possible health effects of radio frequency-electromagnetic fields (RF-EMFs) emitted by wideband code division multiple access (WCDMA) mobile phones in humans. The number of people with self-reported electromagnetic hypersensitivity (EHS), who complain of various subjective symptoms such as headache, dizziness and fatigue, has also increased. However, the origins...

  10. Accuracy of medical subject heading indexing of dental survival analyses.

    Science.gov (United States)

    Layton, Danielle M; Clarke, Michael

    2014-01-01

    To assess the Medical Subject Headings (MeSH) indexing of articles that employed time-to-event analyses to report outcomes of dental treatment in patients. Articles published in 2008 in 50 dental journals with the highest impact factors were hand searched to identify articles reporting dental treatment outcomes over time in human subjects with time-to-event statistics (included, n = 95), without time-to-event statistics (active controls, n = 91), and all other articles (passive controls, n = 6,769). The search was systematic (kappa 0.92 for screening, 0.86 for eligibility). Outcome-, statistic- and time-related MeSH were identified, and differences in allocation between groups were analyzed with chi-square and Fischer exact statistics. The most frequently allocated MeSH for included and active control articles were "dental restoration failure" (77% and 52%, respectively) and "treatment outcome" (54% and 48%, respectively). Outcome MeSH was similar between these groups (86% and 77%, respectively) and significantly greater than passive controls (10%, P indexed as such. Significantly more time-related MeSH were allocated to the included than the active controls (92% and 79%, respectively, P = .02), or to the passive controls (22%, P < .001). MeSH allocation within MEDLINE to time-to-event dental articles was inaccurate and inconsistent. Statistical MeSH were omitted from 30% of the included articles and incorrectly allocated to 15% of active controls. Such errors adversely impact search accuracy.

  11. Representativeness and repeatability of microenvironmental personal and head exposures to radio-frequency electromagnetic fields.

    Science.gov (United States)

    Thielens, Arno; Van den Bossche, Matthias; Brzozek, Christopher; Bhatt, Chhavi Raj; Abramson, Michael J; Benke, Geza; Martens, Luc; Joseph, Wout

    2018-04-01

    The aims of this study were to: i) investigate the repeatability and representativeness of personal radio frequency-electromagnetic fields (RF-EMFs) exposure measurements, across different microenvironments, ii) perform simultaneous evaluations of personal RF-EMF exposures for the whole body and the head, iii) validate the data obtained with a head-worn personal distributed exposimeter (PDE) against those obtained with an on-body worn personal exposimeter (PEM). Data on personal and head RF-EMF exposures were collected by performing measurements across 15 microenvironments in Melbourne, Australia. A body-worn PEM and a head-worn PDE were used for measuring body and head exposures, respectively. The summary statistics obtained for total RF-EMF exposure showed a high representativeness (r 2 > 0.66 for two paths in the same area) and a high repeatability over time (r 2 > 0.87 for repetitions of the same path). The median head exposure in the 900MHz downlink band ranged between 0.06V/m and 0.31V/m. The results obtained during simultaneous measurements using the two devices showed high correlations (0.42 < r 2 < 0.94). The highest mean total RF-EMF exposure was measured in Melbourne's central business district (0.89V/m), whereas the lowest mean total exposure was measured in a suburban residential area (0.05V/m). This study shows that personal RF-EMF microenvironmental measurements in multiple microenvironments have high representativeness and repeatability over time. The personal RF-EMF exposure levels (i.e. body and head exposures) demonstrated moderate to high correlations. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Continuous wave simulations on the propagation of electromagnetic fields through the human head.

    Science.gov (United States)

    Elloian, Jeffrey M; Noetscher, Gregory M; Makarov, Sergey N; Pascual-Leone, Alvaro

    2014-06-01

    Characterizing the human head as a propagation medium is vital for the design of both on-body and implanted antennas and radio-frequency sensors. The following problem has been addressed: find the best radio-frequency path through the brain for a given receiver position-on the top of the sinus cavity. Two parameters, transmitter position and radiating frequency, should be optimized simultaneously such that 1) the propagation path through the brain is the longest; and 2) the received power is maximized. To solve this problem, we have performed a systematic and comprehensive study of the electromagnetic fields excited in the head by small on-body magnetic dipoles (small coil antennas). An anatomically accurate high-fidelity head mesh has been generated from the Visible Human Project data. The base radiator was constructed of two orthogonal magnetic dipoles in quadrature, which enables us to create a directive beam into the head. We have found at least one optimum solution. This solution implies that a distinct RF channel may be established in the brain at a certain frequency and transmitter location.

  13. On board electronic devices safety subject to high frequency electromagnetic radiation effects

    Science.gov (United States)

    Nikitin, V. F.; Smirnov, N. N.; Smirnova, M. N.; Tyurenkova, V. V.

    2017-06-01

    Spacecraft on board electronic devices are subjected to the effects of Space environment, in particular, electromagnetic radiation. The weight limitations for spacecraft pose an important material and structures problem: developing effective protection for on board electronic devices from high frequency electromagnetic radiation. In the present paper the problem of the effect of external high frequency electromagnetic field on electronic devices shielding located on orbital platforms is investigated theoretically. It is demonstrated that the characteristic time for the unsteady stage of the process is negligibly small as compared with characteristic time of electromagnetic field diffusion into a conductor for the studied range of governing parameters. A system of governing material parameters is distinguished, which contribute to protecting electronic devices from induced electrical currents.

  14. Gastrointestinal Physiology During Head Down Tilt Bedrest in Human Subjects

    Science.gov (United States)

    Vaksman, Z.; Guthienz, J.; Putcha, L.

    2008-01-01

    Introduction: Gastrointestinal (GI) motility plays a key role in the physiology and function of the GI tract. It directly affects absorption of medications and nutrients taken by mouth, in addition to indirectly altering GI physiology by way of changes in the microfloral composition and biochemistry of the GI tract. Astronauts have reported nausea, loss of appetite and constipation during space flight all of which indicate a reduction in GI motility and function similar to the one seen in chronic bed rest patients. The purpose of this study is to determine GI motility and bacterial proliferation during -6 degree head down tilt bed rest (HTD). Methods: Healthy male and female subjects between the ages of 25-40 participated in a 60 day HTD study protocol. GI transit time (GITT) was determined using lactulose breath hydrogen test and bacterial overgrowth was measured using glucose breath hydrogen test. H. Pylori colonization was determined using C13-urea breath test (UBIT#). All three tests were conducted on 9 days before HDT, and repeated on HDT days 2, 28, 58, and again on day 7 after HDT. Results: GITT increased during HTD compared to the respective ambulatory control values; GITT was significantly lower on day 7 after HTD. A concomitant increase in bacterial colonization was also noticed during HDT starting after approximately 28 days of HDT. However, H. Pylori proliferation was not recorded during HDT as indicated by UBIT#. Conclusion: GITT significantly decreased during HDT with a concomitant increase in the proliferation of GI bacterial flora but not H. pylori.

  15. Characterization of the Medical Subject Headings thesaurus for pharmacy.

    Science.gov (United States)

    Minguet, Fernando; Van Den Boogerd, Lucienne; Salgado, Teresa M; Correr, Cassyano J; Fernandez-Llimos, Fernando

    2014-11-15

    The completeness and utility of pharmacy-oriented Medical Subject Headings (MeSH) relative to MeSH terminology pertaining to other healthcare professions (dentistry and nursing) are evaluated. The 2013 version of the MeSH thesaurus-the standard vocabulary used by the National Library of Medicine (NLM) to index articles in PubMed and MEDLINE-was searched for dentistry-, nursing-, and pharmacy-specific terms using a truncation strategy (search terms: nurs*, dent*, and pharm*); the hierarchical level of each term and the number of descendant terms (an indication of the granularity of the associated NLM-indexed content) were determined. PubMed searches were conducted to identify areas of the MeSH hierarchy containing dentistry- and nursing-specific terms but no equivalent pharmacy-specific term. The search of the MeSH thesaurus identified 145 terms representing dentistry-specific activities and 94 and 26 terms specific to nursing and pharmacy practice, respectively. Analysis of the three sets of MeSH terms indicated that dentistry-oriented MeSH terms were generally situated more prominently within the MeSH hierarchy than terms for nursing- and pharmacy-oriented research; the MeSH terminology oriented toward nursing or dentistry practice was relatively more granular, allowing for increased specificity and power of information retrieval during PubMed and MEDLINE searches. Seventeen proposed new MeSH terms describing key areas of pharmacy practice were identified; the inclusion of these terms in the MeSH hierarchy could substantially expand and improve the retrievability of NLM-indexed literature. Imbalances and gaps were found in MeSH coverage of pharmacy concepts and terminology relative to MeSH terminology specific to the nursing and dentistry professions. Copyright © 2014 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  16. Electromagnetics

    CERN Document Server

    Rothwell, Edward J

    2009-01-01

    Introductory concepts Notation, conventions, and symbology The field concept of electromagneticsThe sources of the electromagnetic field Problems Maxwell's theory of electromagnetism The postulate Maxwell's equations in moving frames The Maxwell-Boffi equations Large-scale form of Maxwell's equationsThe nature of the four field quantities Maxwell's equations with magnetic sources Boundary (jump) conditions Fundamental theorems The wave nature of the electromagnetic field ProblemsThe static electromagnetic field Static fields and steady currents ElectrostaticsMagnetostatics Static field theorem

  17. Evaluation of electric field distribution in electromagnetic stimulation of human femoral head.

    Science.gov (United States)

    Su, Yukun; Souffrant, Robert; Kluess, Daniel; Ellenrieder, Martin; Mittelmeier, Wolfram; van Rienen, Ursula; Bader, Rainer

    2014-12-01

    Electromagnetic stimulation is a common therapy used to support bone healing in the case of avascular necrosis of the femoral head. In the present study, we investigated a bipolar induction screw system with an integrated coil. The aim was to analyse the influence of the screw parameters on the electric field distribution in the human femoral head. In addition, three kinds of design parameters (the shape of the screw tip, position of the screw in the femoral head, and size of the screw insulation) were varied. The electric field distribution in the bone was calculated using the finite element software Comsol Multiphysics. Moreover, a validation experiment was set up for an identical bone specimen with an implanted screw. The electric potential of points inside and on the surface of the bone were measured and compared to numerical data. The electric field distribution within the bone was clearly changed by the different implant parameters. Repositioning the screw by a maximum of 10 mm and changing the insulation length by a maximum of 4 mm resulted in electric field volume changes of 16% and 7%, respectively. By comparing the results of numerical simulation with the data of the validation experiment, on average, the electric potential difference of 19% and 24% occurred when the measuring points were at a depth of approximately 5 mm within the femoral bone and directly on the surface of the femoral bone, respectively. The results of the numerical simulations underline that the electro-stimulation treatment of bone in clinical applications can be influenced by the implant parameters. © 2014 Wiley Periodicals, Inc.

  18. SPARED RECOGNITION CAPACITY IN ELDERLY AND CLOSED-HEAD-INJURY SUBJECTS WITH CLINICAL MEMORY DEFICITS

    NARCIS (Netherlands)

    Spikman, J.M.; Berg, I.J.; Deelman, B.G.

    This study describes the performance of three groups of subjects on a pictorial forced-recognition task, the Hundred Pictures Test. The aim was to determine whether subjects with memory deficits (elderly and closed-head-injured subjects) would perform as well as healthy young subjects, both on

  19. Gain of electromagnetic radiation traveling in a semiconductor subjected to magnetic and ultrasonic fields

    Energy Technology Data Exchange (ETDEWEB)

    Aleksanyan, A.G.; Boyakhchyan, G.P.; Mirzabekyan, E.G.

    1979-08-01

    A calculation is made of the gain experienced by an electromagnetic wave in a semiconductor subjected to magnetic field and ultrasonic fields. It is shown that the gain can be 1--500 for a wide range of the parameters. Analytic expressions are obtained for the frequency depencence of the real part of the high-frequency conductivity when the pump power, ultrasonic wavelength, and temperature of the semiconductor are varied.

  20. MRI-Based Multiscale Model for Electromagnetic Analysis in the Human Head with Implanted DBS

    Directory of Open Access Journals (Sweden)

    Maria Ida Iacono

    2013-01-01

    Full Text Available Deep brain stimulation (DBS is an established procedure for the treatment of movement and affective disorders. Patients with DBS may benefit from magnetic resonance imaging (MRI to evaluate injuries or comorbidities. However, the MRI radio-frequency (RF energy may cause excessive tissue heating particularly near the electrode. This paper studies how the accuracy of numerical modeling of the RF field inside a DBS patient varies with spatial resolution and corresponding anatomical detail of the volume surrounding the electrodes. A multiscale model (MS was created by an atlas-based segmentation using a 1 mm3 head model (mRes refined in the basal ganglia by a 200 μm2 ex-vivo dataset. Four DBS electrodes targeting the left globus pallidus internus were modeled. Electromagnetic simulations at 128 MHz showed that the peak of the electric field of the MS doubled (18.7 kV/m versus 9.33 kV/m and shifted 6.4 mm compared to the mRes model. Additionally, the MS had a sixfold increase over the mRes model in peak-specific absorption rate (SAR of 43.9 kW/kg versus 7 kW/kg. The results suggest that submillimetric resolution and improved anatomical detail in the model may increase the accuracy of computed electric field and local SAR around the tip of the implant.

  1. Correlation between Trunk Posture and Neck Reposition Sense among Subjects with Forward Head Neck Postures

    OpenAIRE

    Han Suk Lee; Hyung Kuk Chung; Sun Wook Park

    2015-01-01

    Objective. To assess the correlation of abnormal trunk postures and reposition sense of subjects with forward head neck posture (FHP). Methods. In all, postures of 41 subjects were evaluated and the FHP and trunk posture including shoulder, scapular level, pelvic side, and anterior tilting degrees were analyzed. We used the head repositioning accuracy (HRA) test to evaluate neck position senses of neck flexion, neck extension, neck right and left side flexion, and neck right and left rotation...

  2. Activation of rectus capitis posterior major muscles during voluntary retraction of the head in asymptomatic subjects.

    Science.gov (United States)

    Hallgren, Richard C; Rowan, Jacob J; Bai, Peng; Pierce, Steven J; Shafer-Crane, Gail A; Prokop, Lawrence L

    2014-01-01

    The purpose of this study was to assess levels of electromyographic activity measured from rectus capitis posterior major (RCPM) muscles of asymptomatic subjects as their heads moved from a self-defined neutral position to a retracted position. A 2 × 2 within-subjects factorial research design was used. Disposable, intramuscular electrodes were used to collect electromyographic data from asymptomatic subjects between the ages of 20 and 40 years old. Data analysis was performed using mixed effects β regression models. Activation of RCPM muscles was found to significantly increase (P < .0001) as the head moved from a self-defined neutral position to a retracted position. Rectus capitis posterior major muscle activation levels, measured as a function of head position, have not been previously reported. The findings from this study showed that RCPM muscle activation significantly increases during voluntary retraction of the head. Copyright © 2014 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

  3. Impact of head models in N170 component source imaging: results in control subjects and ADHD patients

    Science.gov (United States)

    Beltrachini, L.; Blenkmann, A.; von Ellenrieder, N.; Petroni, A.; Urquina, H.; Manes, F.; Ibáñez, A.; Muravchik, C. H.

    2011-12-01

    The major goal of evoked related potential studies arise in source localization techniques to identify the loci of neural activity that give rise to a particular voltage distribution measured on the surface of the scalp. In this paper we evaluate the effect of the head model adopted in order to estimate the N170 component source in attention deficit hyperactivity disorder (ADHD) patients and control subjects, considering faces and words stimuli. The standardized low resolution brain electromagnetic tomography algorithm (sLORETA) is used to compare between the three shell spherical head model and a fully realistic model based on the ICBM-152 atlas. We compare their variance on source estimation and analyze the impact on the N170 source localization. Results show that the often used three shell spherical model may lead to erroneous solutions, specially on ADHD patients, so its use is not recommended. Our results also suggest that N170 sources are mainly located in the right occipital fusiform gyrus for faces stimuli and in the left occipital fusiform gyrus for words stimuli, for both control subjects and ADHD patients. We also found a notable decrease on the N170 estimated source amplitude on ADHD patients, resulting in a plausible marker of the disease.

  4. Effect of Head Elevation on Passive Upper Airway Collapsibility in Normal Subjects under Propofol Anesthesia

    Science.gov (United States)

    Kobayashi, Masato; Ayuse, Takao; Hoshino, Yuko; Kurata, Shinji; Moromugi, Shunji; Schneider, Hartmut; Kirkness, Jason P.; Schwartz, Alan R.; Oi, Kumiko

    2011-01-01

    Background Head elevation can restore airway patency during anesthesia, although its effect may be offset by concomitant bite opening or accidental neck flexion. The aim of this study is to examine the effect of head elevation on the passive upper airway collapsibility during propofol anesthesia. Method Twenty male subjects were studied, randomized to one of two experimental groups: Fixed-jaw or Free-jaw. Propofol infusion was used for induction and to maintain blood concentration constant at a target level between 1.5 and 2.0 μg/ml. Nasal mask pressure (PN) was intermittently reduced to evaluate the upper airway collapsibility (passive PCRIT) and upstream resistance (RUS) at each level of head elevation (0, 3, 6, & 9 cm). We measured the Frankfort plane (head flexion) and the mandible plane (jaw opening) angles at each level of head elevation. Analysis of variance was used to determine effect of head elevation on PCRIT, head flexion and jaw opening within each group. Results In both groups the Frankfort plane and mandible plane angles increased as with head elevation (P elevation decreased upper airway collapsibility (PCRIT ~ −7 cmH2O at greater than 6 cm elevation) compared to the baseline position (PCRIT ~ −3 cmH2O at 0 cm elevation; P elevating the head position by 6 cm while ensuring mouth closure (centric occlusion) produces substantial decreases in upper airway collapsibility and maintains upper airway patency during anesthesia. PMID:21701378

  5. Effect of head elevation on passive upper airway collapsibility in normal subjects during propofol anesthesia.

    Science.gov (United States)

    Kobayashi, Masato; Ayuse, Takao; Hoshino, Yuko; Kurata, Shinji; Moromugi, Shunji; Schneider, Hartmut; Kirkness, Jason P; Schwartz, Alan R; Oi, Kumiko

    2011-08-01

    Head elevation can restore airway patency during anesthesia, although its effect may be offset by concomitant bite opening or accidental neck flexion. The aim of this study is to examine the effect of head elevation on the passive upper airway collapsibility during propofol anesthesia. Twenty male subjects were studied, randomized to one of two experimental groups: fixed-jaw or free-jaw. Propofol infusion was used for induction and to maintain blood at a constant target concentration between 1.5 and 2.0 μg/ml. Nasal mask pressure (PN) was intermittently reduced to evaluate the upper airway collapsibility (passive PCRIT) and upstream resistance (RUS) at each level of head elevation (0, 3, 6, and 9 cm). The authors measured the Frankfort plane (head flexion) and the mandible plane (jaw opening) angles at each level of head elevation. Analysis of variance was used to determine the effect of head elevation on PCRIT, head flexion, and jaw opening within each group. In both groups the Frankfort plane and mandible plane angles increased with head elevation (P elevation decreased upper airway collapsibility (PCRIT ~ -7 cm H₂O at greater than 6 cm elevation) compared with the baseline position (PCRIT ~ -3 cm H₂O at 0 cm elevation; P Elevating the head position by 6 cm while ensuring mouth closure (centric occlusion) produces substantial decreases in upper airway collapsibility and maintains upper airway patency during anesthesia.

  6. Comparative Study between the "Lista de Encabezamientos de Materia" by Gloria Escamilla and the "Library of Congress Subject Heading" List.

    Science.gov (United States)

    Alvarez, Fernando

    This study shows to what extent Gloria Escamilla's "Lista de Encabezamientos de Materia," the only published Mexican subject heading list, is equivalent to the Library of Congress subject headings (LCSH). A LCSH heading sample is obtained from OCLC's Online Union Catalog. Using the EPIC search from OCLC, 1947 bibliographic records were…

  7. Electromagnetism

    CERN Document Server

    Grant, Ian S

    1990-01-01

    The Manchester Physics Series General Editors: D. J. Sandiford; F. Mandl; A. C. Phillips Department of Physics and Astronomy, University of Manchester Properties of Matter B. H. Flowers and E. Mendoza Optics Second Edition F. G. Smith and J. H. Thomson Statistical Physics Second Edition F. Mandl Electromagnetism Second Edition I. S. Grant and W. R. Phillips Statistics R. J. Barlow Solid State Physics Second Edition J. R. Hook and H. E. Hall Quantum Mechanics F. Mandl Particle Physics Second Edition B. R. Martin and G. Shaw the Physics of Stars Second Edition A. C. Phillips Computing for Scient

  8. Cumulating the Supplements to the Seventh Edition of LC Subject Headings

    Directory of Open Access Journals (Sweden)

    Roy B. Torkington

    1973-12-01

    Full Text Available A description is presented of the project of the University of California Library Automation Program to cumulate the 1966 through 1971 supplements to the Library of Congress Subject Headings. The University of California Institute of Library Research MARC processing software, BIBCON, was used, with specially written programs. The resulting cumulation was edited, printed in book form, and made available to libraries. The final task involved merging six MARC files into one file of over 125,000 records and then printing that file in a format similar to that of LC Subject Headings. The project was a cooperative effort with participation by people from several UC campuses.

  9. Bibliometric perspectives on medical innovation using the medical subject headings of PubMed

    NARCIS (Netherlands)

    Leydesdorff, L.; Rotolo, D.; Rafols, I.

    2012-01-01

    Multiple perspectives on the nonlinear processes of medical innovations can be distinguished and combined using the Medical Subject Headings (MeSH) of the MEDLINE database. Focusing on three main branches—"diseases," "drugs and chemicals," and "techniques and equipment"—we use base maps and overlay

  10. PHYSIOLOGICAL ASSESSMENT OF HEAD-OUT AQUATIC EXERCISES IN HEALTHY SUBJECTS: A QUALITATIVE REVIEW

    Directory of Open Access Journals (Sweden)

    Tiago M Barbosa

    2009-06-01

    Full Text Available In the last decades head-out aquatic exercises became one of the most important physical activities within the health system. Massive research has been produced throughout these decades in order to better understand the role of head-out aquatic exercises in populations' health. Such studies aimed to obtain comprehensive knowledge about the acute and chronic response of subjects performing head-out aquatic exercises. For that, it is assumed that chronic adaptations represent the accumulation of acute responses during each aquatic session. The purpose of this study was to describe the "state of the art" about physiological assessment of head-out aquatic exercises based on acute and chronic adaptations in healthy subjects based on a qualitative review. The main findings about acute response of head-out aquatic exercise according to water temperature, water depth, type of exercise, additional equipment used, body segments exercising and music cadence will be described. In what concerns chronic adaptations, the main results related to cardiovascular and metabolic adaptations, muscular strength, flexibility and body composition improvements will be reported

  11. Analysing the Role of the Subject Head of Department in Secondary Schools in England and Wales: Towards a Theoretical Framework.

    Science.gov (United States)

    Turner, Chris; Bolam, Ray

    1998-01-01

    Argues that contingency theory offers a useful basis for considering the work of subject heads of department in (British) secondary schools, particularly if heads are actively trying to influence the quality of teaching and learning in their curriculum areas. Develops a provisional model to shed light on how department heads actually work with…

  12. Searching the literature using medical subject headings versus text word with PubMed.

    Science.gov (United States)

    Chang, Angela A; Heskett, Karen M; Davidson, Terence M

    2006-02-01

    This study was conducted to investigate the performance of two search strategies in the retrieval of information from the National Library of Medicine (NLM) on otolaryngology-head and neck surgery related conditions and diagnoses using PubMed. Two search strategies-one based on the use of Medical Subject Headings (MeSH) and the second based on text word searching-were compared. The MeSH search provided a more efficient search than the text word search. Head and neck surgeons can most efficiently search the NLM using PubMed as a search engine by initiating the search with MeSH terms. Once a key article is identified, the searcher should use the "Related Articles" feature.

  13. Neck kinematics and sternocleidomastoid muscle activation during neck rotation in subjects with forward head posture

    Science.gov (United States)

    Kim, Man-Sig

    2015-01-01

    [Purpose] The present study investigated differences in the kinematics of the neck and activation of the sternocleidomastoid (SCM) muscle during neck rotation between subjects with and without forward head posture (FHP). [Subjects and Methods] Twenty-eight subjects participated in the study (14 with FHP, 14 without FHP). Subjects performed neck rotation in two directions, left and right. The kinematics of rotation-lateral flexion movement patterns were recorded using motion analysis. Activity in the bilateral SCM muscles was measured using surface electromyography. Differences in neck kinematics and activation of SCM between the groups were analyzed by independent t-tests. [Results] Maintaining FHP increased the rotation-lateral flexion ratio significantly in both directions. The FHP group had significantly faster onset time for lateral flexion movement in both directions during neck rotation. Regarding the electromyography of the SCM muscles during neck rotation in both directions, the activity values of subjects with FHP were greater than those of subjects without FHP for the contralateral SCM muscles. [Conclusion] FHP can induce changes in movement in the frontal plane and SCM muscle activation during neck rotation. Thus, clinicians should consider movement in the frontal plane as well as in the sagittal plane when assessing and treating patients with forward head posture. PMID:26696712

  14. Correlation between Trunk Posture and Neck Reposition Sense among Subjects with Forward Head Neck Postures

    Science.gov (United States)

    Lee, Han Suk; Chung, Hyung Kuk; Park, Sun Wook

    2015-01-01

    Objective. To assess the correlation of abnormal trunk postures and reposition sense of subjects with forward head neck posture (FHP). Methods. In all, postures of 41 subjects were evaluated and the FHP and trunk posture including shoulder, scapular level, pelvic side, and anterior tilting degrees were analyzed. We used the head repositioning accuracy (HRA) test to evaluate neck position senses of neck flexion, neck extension, neck right and left side flexion, and neck right and left rotation and calculated the root mean square error in trials for each subject. Spearman's rank correlation coefficients and regression analysis were used to assess the degree of correlation between the trunk posture and HRA value, and a significance level of α = 0.05 was considered. Results. There were significant correlations between the HRA value of right side neck flexion and pelvic side tilt angle (p postures. Conclusion. Verifying pelvic postures should be prioritized when movement is limited due to the vitiation of the proprioceptive sense of neck caused by FHP. PMID:26583125

  15. Correlation between Trunk Posture and Neck Reposition Sense among Subjects with Forward Head Neck Postures

    Directory of Open Access Journals (Sweden)

    Han Suk Lee

    2015-01-01

    Full Text Available Objective. To assess the correlation of abnormal trunk postures and reposition sense of subjects with forward head neck posture (FHP. Methods. In all, postures of 41 subjects were evaluated and the FHP and trunk posture including shoulder, scapular level, pelvic side, and anterior tilting degrees were analyzed. We used the head repositioning accuracy (HRA test to evaluate neck position senses of neck flexion, neck extension, neck right and left side flexion, and neck right and left rotation and calculated the root mean square error in trials for each subject. Spearman’s rank correlation coefficients and regression analysis were used to assess the degree of correlation between the trunk posture and HRA value, and a significance level of α = 0.05 was considered. Results. There were significant correlations between the HRA value of right side neck flexion and pelvic side tilt angle (p<0.05. If pelvic side tilting angle increases by 1 degree, right side neck flexion increased by 0.76 degrees (p=0.026. However, there were no significant correlations between other neck motions and trunk postures. Conclusion. Verifying pelvic postures should be prioritized when movement is limited due to the vitiation of the proprioceptive sense of neck caused by FHP.

  16. Trismus following different treatment modalities for head and neck cancer: a systematic review of subjective measures.

    Science.gov (United States)

    Loh, Sook Y; Mcleod, Robert W J; Elhassan, Hassan A

    2017-07-01

    The aim of this review was to compare systematically the subjective measure of trismus between different interventions to treat head and neck cancer, particularly those of the oropharynx. Using The Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) Guidelines, Six databases were searched for the text using various terms which include "oropharyngeal/head and neck cancer", "trismus/mouth opening" and the various treatment modalities. Included in the review were clinical studies (> or =10 patients). Three observers independently assessed the papers identified. Among the six studies reviewed, five showed a significantly worst outcome with regard to the quality-of-life questionnaire scores for a radiotherapy or surgery and radiotherapy (RT) ± chemotherapy or chemoradiotherapy when compared to surgery alone. Only one study showed no significant difference between surgery alone and other treatment modalities. Subjective quality-of-life measures are a concurrent part of modern surgical practice. Although subjective measures were utilised to measure post operative trismus successfully, there was no consensus as to which treatment modality had overall better outcomes, with conflicting studies in keeping with the current debate in this field. Larger and higher quality studies are needed to compare all three treatment modalities.

  17. Correlation between Trunk Posture and Neck Reposition Sense among Subjects with Forward Head Neck Postures.

    Science.gov (United States)

    Lee, Han Suk; Chung, Hyung Kuk; Park, Sun Wook

    2015-01-01

    To assess the correlation of abnormal trunk postures and reposition sense of subjects with forward head neck posture (FHP). In all, postures of 41 subjects were evaluated and the FHP and trunk posture including shoulder, scapular level, pelvic side, and anterior tilting degrees were analyzed. We used the head repositioning accuracy (HRA) test to evaluate neck position senses of neck flexion, neck extension, neck right and left side flexion, and neck right and left rotation and calculated the root mean square error in trials for each subject. Spearman's rank correlation coefficients and regression analysis were used to assess the degree of correlation between the trunk posture and HRA value, and a significance level of α = 0.05 was considered. There were significant correlations between the HRA value of right side neck flexion and pelvic side tilt angle (p neck flexion increased by 0.76 degrees (p = 0.026). However, there were no significant correlations between other neck motions and trunk postures. Verifying pelvic postures should be prioritized when movement is limited due to the vitiation of the proprioceptive sense of neck caused by FHP.

  18. Redefining the pharmacology and pharmacy subject category in the journal citation reports using medical subject headings (MeSH).

    Science.gov (United States)

    Minguet, Fernando; Salgado, Teresa M; Santopadre, Claudio; Fernandez-Llimos, Fernando

    2017-10-01

    Background The Journal Citation Reports (JCR) Pharmacology and Pharmacy subject category is heterogeneous. The inclusion of journals with basic and clinical scopes, which have different citation patterns, compromises comparability of impact factors among journals within the category. Objective To subdivide the Pharmacology and Pharmacy category into basic pharmacology, clinical pharmacology, and pharmacy based on the analyses of Medical Subject Headings (MeSH) as a proxy of journals' scopes. Setting JCR. Method All articles, and respective MeSH, published in 2013, 2014, and 2015 in all journals included in the 2014 JCR Pharmacology and Pharmacy category were retrieved from PubMed. Several models using a combination of the 14 MeSH categories and specific MeSH tree branches were tested using hierarchical cluster analysis. Main outcome measure Distribution of journals across the subcategories of the JCR Pharmacology and Pharmacy subject category. Results A total of 107,847 articles from 214 journals were included. Nine different models combining the MeSH categories M (Persons) and N (Health Care) with specific MeSH tree branches (selected ad-hoc) and Pharmacy-specific MeSH (identified in previous research) consistently grouped 142 journals (66.4%) in homogeneous groups reflecting their basic and clinical pharmacology, and pharmacy scopes. Ultimately, journals were clustered into: 150 in basic pharmacology, 43 in clinical pharmacology, 16 in basic pharmacology and clinical pharmacology, and 5 in pharmacy. Conclusion The reformulation of the Pharmacology and Pharmacy category into three categories was demonstrated by the consistent results obtained from testing nine different clustering models using the MeSH terms assigned to their articles.

  19. Dynamic interactions of an integrated vehicle-electromagnetic energy harvester-tire system subject to uneven road excitations

    Science.gov (United States)

    Xing, Jing Tang; Sun, Zhe; Zhou, Sulian; Tan, Mingyi

    2017-04-01

    An investigation is undertaken of an integrated mechanical-electromagnetic coupling system consisting of a rigid vehicle with heave, roll, and pitch motions, four electromagnetic energy harvesters and four tires subject to uneven road excitations in order to improve the passengers' riding comfort and harvest the lost engine energy due to uneven roads. Following the derived mathematical formulations and the proposed solution approaches, the numerical simulations of this interaction system subject to a continuous sinusoidal road excitation and a single ramp impact are completed. The simulation results are presented as the dynamic response curves in the forms of the frequency spectrum and the time history, which reveals the complex interaction characteristics of the system for vibration reductions and energy harvesting performance. It has addressed the coupling effects on the dynamic characteristics of the integrated system caused by: (1) the natural modes and frequencies of the vehicle; (2) the vehicle rolling and pitching motions; (3) different road excitations on four wheels; (4) the time delay of a road ramp to impact both the front and rear wheels, etc., which cannot be tackled by an often used quarter vehicle model. The guidelines for engineering applications are given. The developed coupling model and the revealed concept provide a means with analysis idea to investigate the details of four energy harvester motions for electromagnetic suspension designs in order to replace the current passive vehicle isolators and to harvest the lost engine energy. Potential further research directions are suggested for readers to consider in the future.

  20. Calculating the induced electromagnetic fields in real human head by deep transcranial magnetic stimulation.

    Science.gov (United States)

    Lu, Mai; Ueno, Shoogo

    2013-01-01

    Stimulation of deeper brain structures by transcranial magnetic stimulation (TMS) may be beneficial in the treatment of several neurological and psychiatric disorders. This paper presents numerical simulation of deep transcranial magnetic stimulation (dTMS) by considering double cone, H-and Halo coils. Three-dimensional distributions of the induced fields i.e. magnetic flux density, current density and electric fields in realistic head model by dTMS coils were calculated by impedance method and the results were compared with that of figure-of-eight coil. It was found that double cone and H-coils have significantly deep field penetration at the expense of induced higher and wider spread electrical fields in superficial cortical regions. The Halo coil working with a circular coil carrying currents in opposite directions provides a flexible way to stimulate deep brain structures with much lower stimulation in superficial brain tissues.

  1. SAR and temperature distribution in the rat head model exposed to electromagnetic field radiation by 900 MHz dipole antenna.

    Science.gov (United States)

    Yang, Lei; Hao, Dongmei; Wu, Shuicai; Zhong, Rugang; Zeng, Yanjun

    2013-06-01

    Rats are often used in the electromagnetic field (EMF) exposure experiments. In the study for the effect of 900 MHz EMF exposure on learning and memory in SD rats, the specific absorption rate (SAR) and the temperature rise in the rat head are numerically evaluated. The digital anatomical model of a SD rat is reconstructed with the MRI images. Numerical method as finite difference time domain has been applied to assess the SAR and the temperature rise during the exposure. Measurements and simulations are conducted to characterize the net radiated power of the dipole to provide a precise dosimetric result. The whole-body average SAR and the localized SAR averaging over 1, 0.5 and 0.05 g mass for different organs/tissues are given. It reveals that during the given exposure experiment setup, no significant temperature rise occurs. The reconstructed anatomical rat model could be used in the EMF simulation and the dosimetric result provides useful information for the biological effect studies.

  2. Non-ionizing radiofrequency electromagnetic waves traversing the head can be used to detect cerebrovascular autoregulation responses.

    Science.gov (United States)

    Oziel, M; Hjouj, M; Gonzalez, C A; Lavee, J; Rubinsky, B

    2016-02-22

    Monitoring changes in non-ionizing radiofrequency electromagnetic waves as they traverse the brain can detect the effects of stimuli employed in cerebrovascular autoregulation (CVA) tests on the brain, without contact and in real time. CVA is a physiological phenomenon of importance to health, used for diagnosis of a number of diseases of the brain with a vascular component. The technology described here is being developed for use in diagnosis of injuries and diseases of the brain in rural and economically underdeveloped parts of the world. A group of nine subjects participated in this pilot clinical evaluation of the technology. Substantial research remains to be done on correlating the measurements with physiology and anatomy.

  3. A case study: using social tagging to engage students in learning Medical Subject Headings*

    Science.gov (United States)

    Bresnahan, Megan; Flynn, David B.; Harzbecker, Joseph; Blanchard, Mary; Ginn, David

    2009-01-01

    In exploring new ways of teaching students how to use Medical Subject Headings (MeSH), librarians at Boston University's Alumni Medical Library (AML) integrated social tagging into their instruction. These activities were incorporated into the two-credit graduate course, “GMS MS 640: Introduction to Biomedical Information,” required for all students in the graduate medical science program. Hands-on assignments and in-class exercises enabled librarians to present MeSH and the concept of a controlled vocabulary in a familiar and relevant context for the course's Generation Y student population and provided students the opportunity to actively participate in creating their education. At the conclusion of these activities, students were surveyed regarding the clarity of the presentation of the MeSH vocabulary. Analysis of survey responses indicated that 46% found the concept of MeSH to be the clearest concept presented in the in-class intervention. PMID:19404497

  4. Internal Lymphedema Correlates with Subjective and Objective Measures of Dysphagia in Head and Neck Cancer Patients.

    Science.gov (United States)

    Jackson, Leanne K; Ridner, Sheila H; Deng, Jie; Bartow, Carmin; Mannion, Kyle; Niermann, Ken; Gilbert, Jill; Dietrich, Mary S; Cmelak, Anthony J; Murphy, Barbara A

    2016-09-01

    Tumor/treatment-related internal lymphedema (IL) and/or external lymphedema (EL) are associated with functional deficits and increased symptom burden in head and neck cancer patients (HNCP). Previously, we noted association between EL/IL and patient-reported dysphagia using the Vanderbilt Head and Neck Symptom Survey (VHNSS) version 1.0. To determine the relationship between IL/EL and subjective and objective measures of swallowing function. Eighty-one HNCP completed: (1) VHNSS version 2.0, including 13 swallowing/nutrition-related questions grouped into three clusters: swallow solids (ss), swallow liquids (sl), and nutrition(nt); (2) physical assessment of EL using Foldi scale; (3) endoscopic assessment of IL using Patterson scale (n = 56); and (4) modified barium swallow study rated by dysphagia outcome and severity scale (DOSS) and in conjunction with a swallow evaluation by National Outcomes Measurement System (NOMS). Examinations were performed at varied time points to assess lymphedema spectrum, from baseline (n = 15, 18.1%) to 18 months post-therapy (n = 20, 24.1%). VHNSS swallow/nutrition items scores correlated with NOMS/DOSS ratings (p nutrition scores correlated with maximum grade of swelling for any single structure on Patterson scale: ss (0.43; p = 0.001); sl (0.38; p = 0.004); nt (0.41; p = 0.002). IL of aryepiglottic/pharyngoepiglottic folds, epiglottis, and pyriform sinus were most strongly correlated with VHNSS and NOMS ratings. NOMS/DOSS ratings correlated with EL (> = -0.34; p nutrition items and EL ( 0.20). IL correlated with subjective and objective measures of swallow dysfunction. Longitudinal analysis of trajectory and impact of IL/EL on dysphagia is ongoing.

  5. The Electrical Activity of Neurons Subject to Electromagnetic Induction and Gaussian White Noise

    Science.gov (United States)

    Wang, Ya; Ma, Jun; Xu, Ying; Wu, Fuqiang; Zhou, Ping

    Neurons can give appropriate response to external electrical stimuli and the modes in electrical activities can be carefully selected. Most of the neuron models mainly emphasize on the ion channel currents embedded into the membrane and the properties in electrical activities can be produced in the theoretical models. Indeed, some physical effect should be considered during the model setting for neuronal activities. In fact, induced current and the electrical field will cause the membrane potential to change and an exchange of charged ions during the fluctuation of ion concentration in cell. As a result, the effect of electromagnetic induction should be seriously considered. In this paper, magnetic flux is proposed to describe the effect of electromagnetic field, and the memristor is used to realize coupling on membrane by inputting induced current based on consensus of physical unit. Noise is also considered to detect the dynamical response in electrical activities and stochastic resonance, it is found that multiple modes can be selected in the electrical activities and it could be associated with memory effect and self-adaption in neurons.

  6. Transforming the Medical Subject Headings into Linked Data: Creating the Authorized Version of MeSH in RDF.

    Science.gov (United States)

    Bushman, Barbara; Anderson, David; Fu, Gang

    In February 2014 the National Library of Medicine formed the Linked Data Infrastructure Working Group to investigate the potential for publishing linked data, determine best practices for publishing linked data, and prioritize linked data projects, beginning with transforming the Medical Subject Headings as a linked data pilot. This article will review the pilot project to convert the Medical Subject Headings from XML to RDF. It will discuss the collaborative process, the technical and organizational issues tackled, and the future of linked data at the library.

  7. Mapping of medical acronyms and initialisms to Medical Subject Headings (MeSH) across selected systems.

    Science.gov (United States)

    Shultz, Mary

    2006-10-01

    Given the common use of acronyms and initialisms in the health sciences, searchers may be entering these abbreviated terms rather than full phrases when searching online systems. The purpose of this study is to evaluate how various MEDLINE Medical Subject Headings (MeSH) interfaces map acronyms and initialisms to the MeSH vocabulary. The interfaces used in this study were: the PubMed MeSH database, the PubMed Automatic Term Mapping feature, the NLM Gateway Term Finder, and Ovid MEDLINE. Acronyms and initialisms were randomly selected from 2 print sources. The test data set included 415 randomly selected acronyms and initialisms whose related meanings were found to be MeSH terms. Each acronym and initialism was entered into each MEDLINE MeSH interface to determine if it mapped to the corresponding MeSH term. Separately, 46 commonly used acronyms and initialisms were tested. While performance differed widely, the success rates were low across all interfaces for the randomly selected terms. The common acronyms and initialisms tested at higher success rates across the interfaces, but the differences between the interfaces remained. Online interfaces do not always map medical acronyms and initialisms to their corresponding MeSH phrases. This may lead to inaccurate results and missed information if acronyms and initialisms are used in search strategies.

  8. Leveraging output term co-occurrence frequencies and latent associations in predicting medical subject headings.

    Science.gov (United States)

    Kavuluru, Ramakanth; Lu, Yuan

    2014-11-01

    Trained indexers at the National Library of Medicine (NLM) manually tag each biomedical abstract with the most suitable terms from the Medical Subject Headings (MeSH) terminology to be indexed by their PubMed information system. MeSH has over 26,000 terms and indexers look at each article's full text while assigning the terms. Recent automated attempts focused on using the article title and abstract text to identify MeSH terms for the corresponding article. Most of these approaches used supervised machine learning techniques that use already indexed articles and the corresponding MeSH terms. In this paper, we present a new indexing approach that leverages term co-occurrence frequencies and latent term associations computed using MeSH term sets corresponding to a set of nearly 18 million articles already indexed with MeSH terms by indexers at NLM. The main goal of our study is to gauge the potential of output label co-occurrences, latent associations, and relationships extracted from free text in both unsupervised and supervised indexing approaches. In this paper, using a novel and purely unsupervised approach, we achieve a micro-F-score that is comparable to those obtained using supervised machine learning techniques. By incorporating term co-occurrence and latent association features into a supervised learning framework, we also improve over the best results published on two public datasets.

  9. Improving information retrieval using Medical Subject Headings Concepts: a test case on rare and chronic diseases.

    Science.gov (United States)

    Darmoni, Stéfan J; Soualmia, Lina F; Letord, Catherine; Jaulent, Marie-Christine; Griffon, Nicolas; Thirion, Benoît; Névéol, Aurélie

    2012-07-01

    As more scientific work is published, it is important to improve access to the biomedical literature. Since 2000, when Medical Subject Headings (MeSH) Concepts were introduced, the MeSH Thesaurus has been concept based. Nevertheless, information retrieval is still performed at the MeSH Descriptor or Supplementary Concept level. The study assesses the benefit of using MeSH Concepts for indexing and information retrieval. Three sets of queries were built for thirty-two rare diseases and twenty-two chronic diseases: (1) using PubMed Automatic Term Mapping (ATM), (2) using Catalog and Index of French-language Health Internet (CISMeF) ATM, and (3) extrapolating the MEDLINE citations that should be indexed with a MeSH Concept. Type 3 queries retrieve significantly fewer results than type 1 or type 2 queries (about 18,000 citations versus 200,000 for rare diseases; about 300,000 citations versus 2,000,000 for chronic diseases). CISMeF ATM also provides better precision than PubMed ATM for both disease categories. Using MeSH Concept indexing instead of ATM is theoretically possible to improve retrieval performance with the current indexing policy. However, using MeSH Concept information retrieval and indexing rules would be a fundamentally better approach. These modifications have already been implemented in the CISMeF search engine.

  10. Distancing, self-esteem, and subjective well-being in head and neck cancer.

    Science.gov (United States)

    Devins, Gerald M; Wong, Janice C; Payne, Ada Y M; Lebel, Sophie; Lee, Ruth N F; Mah, Kenneth; Irish, Jonathan; Rodin, Gary

    2015-11-01

    Distancing (i.e. construing oneself as dissimilar to a negatively-stereotyped group) preserves self-esteem and may benefit other domains of subjective well-being. Head and neck cancer (HNC) is stigmatized because major risk factors include avoidable lifestyle variables (smoking, alcohol consumption, and human papilloma virus). Because the benefits of coping efforts, such as distancing, are most evident when people are under stress, we hypothesize that the psychosocial benefits of distancing will be most pronounced when cancer and its treatment interfere substantially with participation in valued activities and interests (i.e. high illness intrusiveness). To test whether distancing preserves self-esteem and other domains of subjective well-being (SWB) in HNC, especially when illness intrusiveness is high. Five hundred and twenty-two HNC outpatients completed a semantic-differential measure of perceived similarity to the 'cancer patient' and measures of illness intrusiveness, self-esteem, depressive symptoms, and psychological well-being in structured interviews. Evaluations of the 'cancer patient' reflected cancer stereotypes. A statistically significant interaction supported the central hypothesis: When people held negative stereotypes, those who construed themselves as similar to the 'cancer patient' reported lower self-esteem than those who construed themselves as dissimilar. Distancing did not benefit other SWB variables. Some results were counter-intuitive: e.g. Emotional distress increased with increasing illness intrusiveness when people did not hold negative cancer stereotypes, but when they held highly negative stereotypes, distress decreased with increasing illness intrusiveness. Overall, distancing preserved self-esteem in people with HNC and was associated with benefits in other SWB domains. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Citation analysis with medical subject Headings (MeSH) using the Web of Knowledge: A new routine

    NARCIS (Netherlands)

    Leydesdorff, L.; Opthof, T.

    2013-01-01

    Citation analysis of documents retrieved from the Medline database (at the Web of Knowledge) has been possible only on a case-by-case basis. A technique is presented here for citation analysis in batch mode using both Medical Subject Headings (MeSH) at the Web of Knowledge and the Science Citation

  12. Quantitative biomedical annotation using medical subject heading over-representation profiles (MeSHOPs

    Directory of Open Access Journals (Sweden)

    Cheung Warren A

    2012-09-01

    Full Text Available Abstract Background MEDLINE®/PubMed® indexes over 20 million biomedical articles, providing curated annotation of its contents using a controlled vocabulary known as Medical Subject Headings (MeSH. The MeSH vocabulary, developed over 50+ years, provides a broad coverage of topics across biomedical research. Distilling the essential biomedical themes for a topic of interest from the relevant literature is important to both understand the importance of related concepts and discover new relationships. Results We introduce a novel method for determining enriched curator-assigned MeSH annotations in a set of papers associated to a topic, such as a gene, an author or a disease. We generate MeSH Over-representation Profiles (MeSHOPs to quantitatively summarize the annotations in a form convenient for further computational analysis and visualization. Based on a hypergeometric distribution of assigned terms, MeSHOPs statistically account for the prevalence of the associated biomedical annotation while highlighting unusually prevalent terms based on a specified background. MeSHOPs can be visualized using word clouds, providing a succinct quantitative graphical representation of the relative importance of terms. Using the publication dates of articles, MeSHOPs track changing patterns of annotation over time. Since MeSHOPs are quantitative vectors, MeSHOPs can be compared using standard techniques such as hierarchical clustering. The reliability of MeSHOP annotations is assessed based on the capacity to re-derive the subset of the Gene Ontology annotations with equivalent MeSH terms. Conclusions MeSHOPs allows quantitative measurement of the degree of association between any entity and the annotated medical concepts, based directly on relevant primary literature. Comparison of MeSHOPs allows entities to be related based on shared medical themes in their literature. A web interface is provided for generating and visualizing MeSHOPs.

  13. Quantitative biomedical annotation using medical subject heading over-representation profiles (MeSHOPs).

    Science.gov (United States)

    Cheung, Warren A; Ouellette, B F Francis; Wasserman, Wyeth W

    2012-09-27

    MEDLINE®/PubMed® indexes over 20 million biomedical articles, providing curated annotation of its contents using a controlled vocabulary known as Medical Subject Headings (MeSH). The MeSH vocabulary, developed over 50+ years, provides a broad coverage of topics across biomedical research. Distilling the essential biomedical themes for a topic of interest from the relevant literature is important to both understand the importance of related concepts and discover new relationships. We introduce a novel method for determining enriched curator-assigned MeSH annotations in a set of papers associated to a topic, such as a gene, an author or a disease. We generate MeSH Over-representation Profiles (MeSHOPs) to quantitatively summarize the annotations in a form convenient for further computational analysis and visualization. Based on a hypergeometric distribution of assigned terms, MeSHOPs statistically account for the prevalence of the associated biomedical annotation while highlighting unusually prevalent terms based on a specified background. MeSHOPs can be visualized using word clouds, providing a succinct quantitative graphical representation of the relative importance of terms. Using the publication dates of articles, MeSHOPs track changing patterns of annotation over time. Since MeSHOPs are quantitative vectors, MeSHOPs can be compared using standard techniques such as hierarchical clustering. The reliability of MeSHOP annotations is assessed based on the capacity to re-derive the subset of the Gene Ontology annotations with equivalent MeSH terms. MeSHOPs allows quantitative measurement of the degree of association between any entity and the annotated medical concepts, based directly on relevant primary literature. Comparison of MeSHOPs allows entities to be related based on shared medical themes in their literature. A web interface is provided for generating and visualizing MeSHOPs.

  14. Medical Subject Heading (MeSH) annotations illuminate maize genetics and evolution.

    Science.gov (United States)

    Beissinger, Timothy M; Morota, Gota

    2017-01-01

    High-density marker panels and/or whole-genome sequencing, coupled with advanced phenotyping pipelines and sophisticated statistical methods, have dramatically increased our ability to generate lists of candidate genes or regions that are putatively associated with phenotypes or processes of interest. However, the speed with which we can validate genes, or even make reasonable biological interpretations about the principles underlying them, has not kept pace. A promising approach that runs parallel to explicitly validating individual genes is analyzing a set of genes together and assessing the biological similarities among them. This is often achieved via gene ontology analysis, a powerful tool that involves evaluating publicly available gene annotations. However, additional resources such as Medical Subject Headings (MeSH) can also be used to evaluate sets of genes to make biological interpretations. In this manuscript, we describe utilizing MeSH terms to make biological interpretations in maize. MeSH terms are assigned to PubMed-indexed manuscripts by the National Library of Medicine, and can be directly mapped to genes to develop gene annotations. Once mapped, these terms can be evaluated for enrichment in sets of genes or similarity between gene sets to provide biological insights. Here, we implement MeSH analyses in five maize datasets to demonstrate how MeSH can be leveraged by the maize and broader crop-genomics community. We demonstrate that MeSH terms can be effectively leveraged to generate hypotheses and make biological interpretations in maize, and we provide a pipeline that enables the use of MeSH terms in other plant species.

  15. Interexaminer reliability of the electromagnetic radiation receiver for determining lumbar spinal joint dysfunction in subjects with low back pain

    Energy Technology Data Exchange (ETDEWEB)

    Gemmell, H.A.; Jacobson, B.H.; Edwards, S.W.; Heng, B.J.

    1990-03-01

    Twenty subjects (6 male, 14 female) with low back pain were examined by two experienced and licensed chiropractic doctors (E1 and E2). Both examiners examined the patients using a Toftness Electromagnetic Radiation Receiver (EMRR) and by manual palpation (MP) of the spinous processes. Interexaminer reliability was calculated at three sites (L3, L4, L5) for the following combinations: (a) E1,MP--E2,MP; (b) E1,EMRR--E2,EMRR; (c) E1,MP--E2,EMRR; and (d) E2,MP--E1,EMRR, and intraexaminer reliability was calculated for the following variables: (e) E1,MP--E1,EMRR; and (f) E2,MP--E2,EMRR. Results of a Kappa coefficient analysis for interexaminer reliability of the stated combinations and at the specific sites were: (a) -0.071, 0.400, 0.200; (b) -0.013, 0.100, -0.120; (c) 0.286, 0.300, 0.200; (d) -0.081, 0.000, 0.048. These results predominantly indicate a poor to fair interexaminer reliability. The results of a Kappa coefficient analysis for intraexaminer reliability of the stated combinations were: (e) 0.111, 0.400, 0.737; (f) 0.000, 0.100, 0.368. These results indicate a poor to fair reliability. It was concluded that in subjects with low back pain the EMRR may not be a reliable indicator of spinal joint dysfunction.

  16. THE SHORT-TERM EFFECT OF A HOME-BASED PROGRAM TO CORRECT FORWARD HEAD POSTURE IN ASYMPTOMATIC SUBJECTS

    Directory of Open Access Journals (Sweden)

    Ahmed Omar Abdelnaeem

    2015-08-01

    Full Text Available Background: Neck pain and dysfunction may be the consequence of adopting sustained non-neutral spinal postures. Such postures are associated with increased activation of the neck-shoulder stabilizer muscles, which eventually increase the loading of cervical spine. Forward head posture is a common postural dysfunction that has been associated with many musculoskeletal disorders. The purpose of the study was to investigate the effects of deep cervical flexor muscles training on the severity of forward head posture in asymptomatic subjects. Methods: Forty-one asymptomatic subjects volunteered in this study. Participants were randomly assigned into an intervention group (n= 20that received a home-based training of deep cervical flexor muscles for 6-weeks, and a control group(n= 21 that received only the assessment procedure. Subjects were assessed at baseline and 6weeks later with regards to the severity of forward head as indicated by the cranio-vertebral angle. Also, the strength and endurance of the deep flexor muscles were assessed. Results: After six weeks, participants in the intervention group showed significant improvement in all measured variables compared to the control group. Furthermore, participants in the intervention group showed significant difference in all measured variables after 6-weeks of training compared to baseline, whereas those in the control group remained the same. Conclusion: Six-weeks of deep cervical training improves forward head posture and deep flexors strength and endurance in asymptomatic subjects. Thus, this exercise could be used as a preventive measure against the development of neck dysfunction in at risk population even before the onset of any symptoms.

  17. Hyoid bone position and head posture comparison in skeletal Class I and Class II subjects: A retrospective cephalometric study

    Directory of Open Access Journals (Sweden)

    Pawankumar Dnyandeo Tekale

    2014-01-01

    Full Text Available Objective: The aim of the study was to investigate the hyoid bone position and the head posture using lateral cephalograms in subjects with skeletal Class I and skeletal Class II pattern and to investigate the gender differences. Materials and Methods: The study used lateral cephalograms of 40 subjects (20 skeletal Class I pattern; 20 skeletal Class II pattern. Lateral cephalograms were traced and analyzed for evaluation of the hyoid bone position and the head posture using 34 parameters. Independent sample t-test was performed to compare the differences between the two groups and between genders in each group. Statistical tests were performed using NCSS 2007 software (NCSST, Kaysville, Utah, USA. Results: The linear measurements between the hyoid bone (H and cervical spine (CV2ia, the nasion-sella line, palatal line nasion line, the anterior nasal spine (ANS to perpendicular projection of H on the NLP (NLP- Nasal Linear Projection (H-NLP/ANS as well as the posterior cranial points (Bo, Ar and S points were found to be less in skeletal Class II subjects. The measurement H-CV2ia was found to be less in males with skeletal Class I pattern and H-CV4ia was found to be less in males with skeletal Class II pattern. The natural head posture showed no significant gender differences. Conclusion: The position of hyoid bone was closer to the cervical vertebra horizontally in skeletal Class II subjects when compared with skeletal Class I subjects. In males, the hyoid bone position was closer to the cervical vertebra horizontally both in skeletal Class I and skeletal Class II subjects.

  18. Revision of the Wayne State University Medical Library subject catalog using the 1966 Medical Subject Heading system.

    Science.gov (United States)

    Pings, V M; Ferrario, J A

    1967-01-01

    Wayne State University Medical Library (WSUML) revised its monograph subject catalog in 1961 utilizing the 1960 edition of MeSH as an authority list. With the introduction of MEDLARS in 1963 by NLM, all topical subheadings were omitted from MeSH. Inasmuch as this omission could not accommodate the needs of WSUML, the 1960 edition of MeSH was retained as a guideline. In January 1966, when MeSH resumed the incorporation of topical subheadings, WSUML was faced with a decision whether to continue the current policy or to adopt the form as presented in the latest edition of MeSH. This report describes the methodology employed in adopting a new policy, the findings which resulted from the change, and an evaluation of this reorganization.

  19. [Predict factors associated with malnutrition from patient generated subjective global assessment (PG-SGA) in head and neck cancer patients].

    Science.gov (United States)

    Arribas, L; Hurtós, L; Milà, R; Fort, E; Peiró, I

    2013-01-01

    Patient Generated Subjective Global Assessment (PG-SGA) is a validated tool for nutrition evaluation in patients with cancer. The aim of our study was to estimate the prevalence of malnutrition in head and neck cancer patients at diagnosis and evaluate the independent prognostic factors for malnutrition from PG-SGA. All outpatients attending at the Head and Neck Cancer Multidisciplinary Meeting for primary diagnosis, staging and treatment were evaluated by an oncology dietitian using the patient generated subjective global assessment (PG-SGA). Patients with recurrences or secondary tumours will be excluded. 64 patients were evaluated (55 men and 9 women) with an average age of 63 years and body mass index (BMI) of 25.3 kg/m(2) (SD ± 5.18). After the nutritional assessment we observed that 43.8% of patients were malnourished or at risk of malnutrition. The most frequent symptom at diagnosis was dysphagia (48.4%) and anorexia (26.6%). From PG-SGA, the main prognostic factors (p<0,001) were the percentage of weight loss, serum albumin levels, BMI and the presence of dysphagia or/and anorexia prior diagnosis. Parameters as BMI, weight loss and low albumin levels at the time of diagnosis in head and neck cancer patients are independent predictors for malnutrition as well as the presence of anorexia or dysphagia.reaffirms the need for sustainability of interventions over time. Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

  20. Basin Characterisation by Means of Joint Inversion of Electromagnetic Geophysical Data, Borehole Data and Multivariate Statistical Methods: The Loop Head Peninsula, Western Ireland, Case Study

    Science.gov (United States)

    Campanya, J. L.; Ogaya, X.; Jones, A. G.; Rath, V.; McConnell, B.; Haughton, P.; Prada, M.

    2016-12-01

    The Science Foundation Ireland funded project IRECCSEM project (www.ireccsem.ie) aims to evaluate Ireland's potential for onshore carbon sequestration in saline aquifers by integrating new electromagnetic geophysical data with existing geophysical and geological data. One of the objectives of this component of IRECCSEM is to characterise the subsurface beneath the Loop Head Peninsula (part of Clare Basin, Co. Clare, Ireland), and identify major electrical resistivity structures that can guide an interpretation of the carbon sequestration potential of this area. During the summer of 2014, a magnetotelluric (MT) survey was carried out on the Loop Head Peninsula, and data from a total of 140 sites were acquired, including audio-magnetotelluric (AMT), and broadband magnetotelluric (BBMT). The dataset was used to generate shallow three-dimensional (3-D) electrical resistivity models constraining the subsurface to depths of up to 3.5 km. The three-dimensional (3-D) joint inversions were performed using three different types of electromagnetic data: MT impedance tensor (Z), geomagnetic transfer functions (T), and inter-station horizontal magnetic transfer-functions (H). The interpretation of the results was complemented with second-derivative models of the resulting electrical resistivity models, and a quantitative comparison with borehole data using multivariate statistical methods. Second-derivative models were used to define the main interfaces between the geoelectrical structures, facilitating superior comparison with geological and seismic results, and also reducing the influence of the colour scale when interpreting the results. Specific analysis was performed to compare the extant borehole data with the electrical resistivity model, identifying those structures that are better characterised by the resistivity model. Finally, the electrical resistivity model was also used to propagate some of the physical properties measured in the borehole, when a good relation was

  1. The multi-modal responses of a physical head model subjected to various blast exposure conditions

    Science.gov (United States)

    Ouellet, S.; Phillippens, M.

    2017-11-01

    The local and global biomechanical response of the body to a blast wave is the first step of a sequence that leads to the development of stresses and strains which can exceed the tolerance of brain tissue. These stresses and strains may then lead to neuro-physical changes in the brain and contribute to initiate a cascade of events leading to injury. The specific biomechanical pathways by which the blast energy is transmitted through the head structure are, however, not clearly understood. Multiple transmission mechanisms have been proposed to explain the generation of brain stresses following the impingement of a blast wave on the head. With the use of a physical head model, the work presented here aims at demonstrating that the proposed transmission mechanisms are not mutually exclusive. They are part of a continuum of head responses where, depending on the exposure conditions, a given mechanism may or may not dominate. This article presents the joint analysis of previous blast test results generated with the brain injury protection evaluation device (BIPED) headform under four significantly different exposure conditions. The focus of the analysis is to demonstrate how the nature of the recorded response is highly dependent on the exposure characteristics and consequently, on the method used to reproduce blast exposure in a laboratory environment. The timing and magnitude of the variations in intra-cranial pressures (ICP) were analysed relative to the external pressure field in order to better understand the wave dynamics occurring within the brain structure of the headform. ICP waveforms were also analysed in terms of their energy spectral density to better identify the energy partitioning between the different modes of response. It is shown that the BIPED response is multi-modal and that the energy partitioning between its different modes of response is greatly influenced by exposure characteristics such as external peak overpressure, impulse, blast wave

  2. Dental needs in Brazilian patients subjected to head and neck radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Rosales, Ana Carolina de Mesquita Netto; Jorge, Jacks; Almeida, Oslei Paes de; Lopes, Marcio Ajudarte [University of Campinas (UNICAMP), Piracicaba, SP (Brazil). Piracicaba Dental School. Dept. of Oral Diagnosis], e-mail: malopes@fop.unicamp.br; Esteves, Sergio Carlos Barros [Center of Oncology, Piracicaba, SP (Brazil)

    2009-07-01

    In spite of its recognized benefits in the treatment of malignant tumors, radiation therapy have several side effects in the head and neck region. The evaluation of oral conditions by a dentist is important to prevent or minimize these problems. The aim of this retrospective review was to analyze the dental needs in 357 patients who received radiotherapy in the head and neck region and were treated at Orocentro/FOP/UNICAMP, between January 1990 and December 2004. Review of patient files showed that dental examination before radiotherapy was not performed in 148 patients (41.5%) and was done in 209 patients (58.5%). From the total of examined patients, 94 (45%) did not require dental procedures at the moment of examination, while 115 (55%) presented some sort of dental need. Following the patients after the radiotherapy, it was observed that the group of patients that was evaluated before radiation presented less need of restorations, root canal filling and dental extractions than those who were not evaluated. The results of this study confirm that the evaluation of oral conditions prior to radiotherapy is essential to minimize the dental needs, emphasizing the importance of the dentist in the multidisciplinary team that treats cancer patients. (author)

  3. Comparison of Medical Subject Headings and text-word searches in MEDLINE to retrieve studies on sleep in healthy individuals*

    Science.gov (United States)

    Jenuwine, Elizabeth S.; Floyd, Judith A.

    2004-01-01

    Objective: The objective was to investigate the performance of two search strategies in the retrieval of primary research papers containing descriptive information on the sleep of healthy people from MEDLINE. Methodology: Two search strategies—one based on the use of only Medical Subject Headings (MeSH), the second based on text-word searching—were evaluated as to their specificity and sensitivity in retrieving a set of relevant research papers published in the journal Sleep from 1996 to 2001 that were preselected by a hand search. Results: The subject search provided higher specificity than the text-word search (66% and 47%, respectively) but lower sensitivity (78% for the subject search versus 88% for the text-word search). Each search strategy gave some unique relevant hits. Conclusions: The two search strategies complemented each other and should be used together for maximal retrieval. No combination of MeSH terms could provide comprehensive yet reasonably precise retrieval of relevant articles. The text-word searching had sensitivity and specificity comparable to the subject search. In addition, use of text words “normal,” “healthy,” and “control” in the title or abstract fields to limit the final sets provided an efficient way to increase the specificity of both search strategies. PMID:15243641

  4. Three-Way Catalog Division Combined with Conversion to Medical Subject Headings (MeSH) in a Medium-sized Medical Library *†

    Science.gov (United States)

    McNutt, Eleanor M.; Poland, Ursula H.

    1974-01-01

    Conversion to MeSH and other reasons are enumerated for the division of an undivided dictionary card catalog into a three-way divided catalog, consisting of Proper Names, Titles, and Topical Subjects sections. Methodology of division is described. Conversion from Library of Congress Subject Headings to Medical Subject Headings (MeSH) as an authority list stimulated such concurrent changes as (1) the introduction of a guide card system that eliminates typing of subject headings on catalog cards and (2) the adoption of a filing system that employs reverse chronological order for all types of sequential material in the Proper Names and Titles sections and for all material in the Topical Subjects section. The ancillary decisions, procedures, and methods necessitated by these major conversions are also described. PMID:4462686

  5. Image quality analysis of high-density diffuse optical tomography incorporating a subject-specific head model

    Directory of Open Access Journals (Sweden)

    Yuxuan eZhan

    2012-05-01

    Full Text Available High-density diffuse optical tomography (HD-DOT methods have shown significant improvement in localization accuracy and image resolution compared to traditional topographic near infrared spectroscopy (NIRS of the human brain. In this work we provide a comprehensive evaluation of image quality in visual cortex mapping via a simulation study with the use of an anatomical head model derived from MRI data of a human subject. A model of individual head anatomy provides the surface shape and internal structure that allow for the construction of a more realistic physical model for the forward problem, as well as the use of a structural constraint in the inverse problem. The HD-DOT model utilized here incorporates multiple source-detector separations with continuous-wave data with added noise based on experimental results. To evaluate image quality we quantify the localization error and localized volume at half maximum (LVHM throughout a region of interest (ROI within the visual cortex and systematically analyze the use of whole brain tissue spatial constraint within image reconstruction. Our results demonstrate that an image quality with less than 10 mm in localization error and 1000 m3 in LVHM can be obtained up to 13 mm below the scalp surface with a typical unconstrained reconstruction and up to 18 mm deep when a spatial constraint based on the brain tissue is utilized.

  6. Bibliometric Perspectives on Medical Innovation using the Medical Subject Headings (MeSH) of PubMed

    CERN Document Server

    Leydesdorff, Loet; Rafols, Ismael

    2012-01-01

    Multiple perspectives on the nonlinear processes of medical innovations can be distinguished and combined using the Medical Subject Headings (MeSH) of the Medline database. Focusing on three main branches-"diseases," "drugs and chemicals," and "techniques and equipment"-we use base maps and overlay techniques to investigate the translations and interactions and thus to gain a bibliometric perspective on the dynamics of medical innovations. To this end, we first analyze the Medline database, the MeSH index tree, and the various options for a static mapping from different perspectives and at different levels of aggregation. Following a specific innovation (RNA interference) over time, the notion of a trajectory which leaves a signature in the database is elaborated. Can the detailed index terms describing the dynamics of research be used to predict the diffusion dynamics of research results? Possibilities are specified for further integration between the Medline database, on the one hand, and the Science Citati...

  7. Subjectivity

    Directory of Open Access Journals (Sweden)

    Jesús Vega Encabo

    2015-11-01

    Full Text Available In this paper, I claim that subjectivity is a way of being that is constituted through a set of practices in which the self is subject to the dangers of fictionalizing and plotting her life and self-image. I examine some ways of becoming subject through narratives and through theatrical performance before others. Through these practices, a real and active subjectivity is revealed, capable of self-knowledge and self-transformation. 

  8. Head-to-toe whole-body MRI in psoriatic arthritis, axial spondyloarthritis and healthy subjects

    DEFF Research Database (Denmark)

    Poggenborg, René Panduro; Pedersen, Susanne Juhl; Eshed, Iris

    2015-01-01

    OBJECTIVES: By whole-body MRI (WBMRI), we aimed to examine the frequency and distribution of inflammatory and structural lesions in PsA patients, SpA patients and healthy subjects (HSs), to introduce global WBMRI inflammation/damage scores, and to assess WBMRI's reproducibility and correlation...... of inflammation and structural damage were constructed, and WBMRI findings were compared with clinical measures and convMRI (SpA/HS: spine and SI joints; PsA/HS: hand). RESULTS: The readability (92-100%) and reproducibility (intrareader intraclass correlation coefficient: 0.62-1.0) were high in spine/SI joint......-15]} and SpA [8 (IQR 2-14)] than in HSs [2.5 (IQR 1-4.5)], both P structural damage scores (erosion, fat infiltration and ankylosis) were higher in SpA [7 (IQR 3-12)] than HSs [1.5 (IQR 0-4.5)], P = 0.012. Correlations between WBMRI and convMRI spine and SI joint scores were ρ = 0...

  9. Activation of biceps femoris long head reduces tibiofemoral anterior shear force and tibial internal rotation torque in healthy subjects.

    Science.gov (United States)

    Azmi, Nur Liyana; Ding, Ziyun; Xu, Rui; Bull, Anthony M J

    2018-01-01

    The anterior cruciate ligament (ACL) provides resistance to tibial internal rotation torque and anterior shear at the knee. ACL deficiency results in knee instability. Optimisation of muscle contraction through functional electrical stimulation (FES) offers the prospect of mitigating the destabilising effects of ACL deficiency. The hypothesis of this study is that activation of the biceps femoris long head (BFLH) reduces the tibial internal rotation torque and the anterior shear force at the knee. Gait data of twelve healthy subjects were measured with and without the application of FES and taken as inputs to a computational musculoskeletal model. The model was used to investigate the optimum levels of BFLH activation during FES gait in reducing the anterior shear force to zero. This study found that FES significantly reduced the tibial internal rotation torque at the knee during the stance phase of gait (p = 0.0322) and the computational musculoskeletal modelling revealed that a mean BFLH activation of 20.8% (±8.4%) could reduce the anterior shear force to zero. At the time frame when the anterior shear force was zero, the internal rotation torque was reduced by 0.023 ± 0.0167 Nm/BW, with a mean 188% reduction across subjects (p = 0.0002). In conclusion, activation of the BFLH is able to reduce the tibial internal rotation torque and the anterior shear force at the knee in healthy control subjects. This should be tested on ACL deficient subject to consider its effect in mitigating instability due to ligament deficiency. In future clinical practice, activating the BFLH may be used to protect ACL reconstructions during post-operative rehabilitation, assist with residual instabilities post reconstruction, and reduce the need for ACL reconstruction surgery in some cases.

  10. The video head impulse test (vHIT of semicircular canal function – age dependent normative values of VOR gain in healthy subjects

    Directory of Open Access Journals (Sweden)

    Leigh Andrew McGarvie

    2015-07-01

    Full Text Available Background/Hypothesis. The video Head Impulse Test (vHIT is now widely used to test the function of each of the six semicircular canals individually by measuring the eye rotation response to an abrupt head rotation in the plane of the canal. The main measure of canal adequacy is the ratio of the eye movement response to the head movement stimulus i.e. the gain of the vestibulo-ocular reflex (VOR. However there is a need for normative data about how VOR gain is affected by age and also by head velocity, to allow the response of any particular patient to be compared to response of healthy subjects in their age range. In this study we determined for all six semicircular canals, normative values of VOR gain, for each canal across a range of head velocities, for healthy subjects in each decade of life.Study Design. The VOR gain was measured for all canals across a range of head velocities for at least 10 healthy subjects in decade age bands: 10-19, 20-29, 30-39, 40-49, 50-59, 60-69, 70-79, 80-89. Methods. The compensatory eye movement response to a small, unpredictable, abrupt head rotation (head impulse was measured by the ICS Impulse prototype system. The same operator delivered every impulse to every subject. Results. VOR gain decreased at high head velocities, but was largely unaffected by age into the 80-89 year age group. There were some small but systematic differences between the two directions of head rotation, which appear to be largely due to the fact that in this study only the right eye was measured. The results are considered in relation to recent evidence about the effect of age on VOR performance.Conclusion. These normative values allow the results of any particular patient to be compared to the values of healthy people in their age range and so allow, for example, detection of whether a patient has a bilateral vestibular loss. VOR gain, as measured directly by the eye movement response to head rotation, seems largely unaffected by

  11. Head repositioning accuracy in patients with neck pain and asymptomatic subjects: concurrent validity, influence of motion speed, motion direction and target distance.

    Science.gov (United States)

    Dugailly, Pierre-Michel; De Santis, Roberta; Tits, Mathieu; Sobczak, Stéphane; Vigne, Anna; Feipel, Véronique

    2015-12-01

    Cervicocephalic kinesthetic deficiencies have been demonstrated in patients with chronic neck pain (NP). On the other hand, authors emphasized the use of different motion speeds for assessing functional impairment of the cervical spine. The objectives of this study were (1) to investigate the head repositioning accuracy in NP patients and control subjects and (2) to assess the influence of target distance, motion speed, motion direction and pain. Seventy-one subjects (36 healthy subjects and 35 NP patients; age 30-55 years) performed the head repositioning test (HRT) at two different speeds for horizontal and vertical movements and at two different distances. For each condition, six consecutive trials were sampled. The study showed the validity and reproducibility of the HRT, confirming a dysfunctional threshold of 4.5°. Normative values of head repositioning error up to 3.6° and 7.1° were identified for healthy and NP subjects, respectively. A distance of 180 cm from the target and a natural motion speed increased HRT accuracy. Repositioning after extension movement showed a significantly larger error in both groups. Intensity, duration of pain as well as pain level did not significantly alter head repositioning error. The assessment of proprioceptive performance in healthy and NP subjects allowed the validation of the HRT. The HRT is a simple, not expensive and fast test, easily implementable in daily practice to assess and monitor treatment and evolution of proprioceptive cervical deficits.

  12. Effects of suboccipital release with craniocervical flexion exercise on craniocervical alignment and extrinsic cervical muscle activity in subjects with forward head posture.

    Science.gov (United States)

    Kim, Bo-Been; Lee, Ji-Hyun; Jeong, Hyo-Jung; Cynn, Heon-Seock

    2016-10-01

    Forward head posture is a head-on-trunk malalignment, which results in musculoskeletal dysfunction and neck pain. To improve forward head posture, both the craniocervical flexion exercise and the suboccipital release technique have been used. The purpose of this study was to compare the immediate effects of craniocervical flexion exercise and suboccipital release combined with craniocervical flexion exercise on craniovertebral angle, cervical flexion and extension range of motion, and the muscle activities of the sternocleidomastoid, anterior scalene, and splenius capitis during craniocervical flexion exercise in subjects with forward head posture. In total, 19 subjects (7 males, 12 females) with forward head posture were recruited using G-power software. Each subject performed craniocervical flexion exercise and suboccipital release combined with craniocervical flexion exercise in random order. After one intervention was performed, the subject took a 20min wash out period to minimize any carry-over effect between interventions. Craniovertebral angle, cervical flexion and extension range of motion, and the muscle activities of the sternocleidomastoid, anterior scalene, and splenius capitis were measured. A one-way, repeated-measures ANOVA was used to assess differences between the effects of the craniocervical flexion exercise and suboccipital release combined with craniocervical flexion exercise interventions in the same group. Craniovertebral angle (pflexion range of motion (pflexion exercise compared to craniocervical flexion exercise alone. The muscle activities of the sternocleidomastoid, anterior scalene, and splenius capitis were significantly lower during suboccipital release combined with craniocervical flexion exercise than during craniocervical flexion exercise alone across all craniocervical flexion exercise phases except the first (all pflexion exercise provided superior benefits relative to craniocervical flexion exercise alone as an intervention for

  13. Two Similarity Metrics for Medical Subject Headings (MeSH): An Aid to Biomedical Text Mining and Author Name Disambiguation.

    Science.gov (United States)

    Smalheiser, Neil R; Bonifield, Gary

    2016-04-06

    In the present paper, we have created and characterized several similarity metrics for relating any two Medical Subject Headings (MeSH terms) to each other. The article-based metric measures the tendency of two MeSH terms to appear in the MEDLINE record of the same article. The author-based metric measures the tendency of two MeSH terms to appear in the body of articles written by the same individual (using the 2009 Author-ity author name disambiguation dataset as a gold standard). The two metrics are only modestly correlated with each other (r = 0.50), indicating that they capture different aspects of term usage. The article-based metric provides a measure of semantic relatedness, and MeSH term pairs that co-occur more often than expected by chance may reflect relations between the two terms. In contrast, the author metric is indicative of how individuals practice science, and may have value for author name disambiguation and studies of scientific discovery. We have calculated article metrics for all MeSH terms appearing in at least 25 articles in MEDLINE (as of 2014) and author metrics for MeSH terms published as of 2009. The dataset is freely available for download and can be queried at http://arrowsmith.psych.uic.edu/arrowsmith_uic/mesh_pair_metrics.html. Handling editor: Elizabeth Workman, MLIS, PhD.

  14. Transcending Library Catalogs: A Comparative Study of Controlled Terms in Library of Congress Subject Headings and User-Generated Tags in LibraryThing for Transgender Books

    Science.gov (United States)

    Adler, Melissa

    2009-01-01

    Perhaps the greatest power of folksonomies, especially when set against controlled vocabularies like the Library of Congress Subject Headings, lies in their capacity to empower user communities to name their own resources in their own terms. This article analyzes the potential and limitations of both folksonomies and controlled vocabularies for…

  15. Cited References and Medical Subject Headings (MeSH) as Two Different Knowledge Representations : Clustering and Mappings at the Paper Level

    NARCIS (Netherlands)

    Leydesdorff, L.; Comins, J.A.; Sorensen, A.A.; Bornmann, L.; Hellsten, I.

    2016-01-01

    For the biomedical sciences, the Medical Subject Headings (MeSH) make available a rich feature which cannot currently be merged properly with widely used citing/cited data. Here, we provide methods and routines that make MeSH terms amenable to broader usage in the study of science indicators: using

  16. Comparison of optic area measurement using fundus photography and optical coherence tomography between optic nerve head drusen and control subjects.

    Science.gov (United States)

    Flores-Rodríguez, Patricia; Gili, Pablo; Martín-Ríos, María Dolores; Grifol-Clar, Eulalia

    2013-03-01

    To compare optic disc area measurement between optic nerve head drusen (ONHD) and control subjects using fundus photography, time-domain optical coherence tomography (TD-OCT) and spectral-domain optical coherence tomography (SD-OCT). We also made a comparison between each of the three techniques. We performed our study on 66 eyes (66 patients) with ONHD and 70 healthy control subjects (70 controls) with colour ocular fundus photography at 20º (Zeiss FF 450 IR plus), TD-OCT (Stratus OCT) with the Fast Optic Disc protocol and SD-OCT (Cirrus OCT) with the Optic Disc Cube 200 × 200 protocol for measurement of the optic disc area. The measurements were made by two observers and in each measurement a correction of the image magnification factor was performed. Measurement comparison using the Student's t-test/Mann-Whitney U test, the intraclass correlation coefficient, Pearson/Spearman rank correlation coefficient and the Bland-Altman plot was performed in the statistical analysis. Mean and standard deviation (SD) of the optic disc area in ONHD and in controls was 2.38 (0.54) mm(2) and 2.54 (0.42) mm(2), respectively with fundus photography; 2.01 (0.56) mm(2) and 1.66 (0.37) mm(2), respectively with TD-OCT, and 2.03 (0.49) mm(2) and 1.75 (0.38) mm(2), respectively with SD-OCT. In ONHD and controls, repeatability of optic disc area measurement was excellent with fundus photography and optical coherence tomography (TD-OCT and SD-OCT), but with a low degree of agreement between both techniques. Optic disc area measurement is smaller in ONHD compared to healthy subjects with fundus photography, unlike time-domain and spectral-domain optical coherence tomography in which the reverse is true. Both techniques offer good repeatability, but a low degree of correlation and agreement, which means that optic disc area measurement is not interchangeable or comparable between techniques. Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

  17. Effects of exposure to electromagnetic fields emitted by GSM 900 and WCDMA mobile phones on cognitive function in young male subjects.

    Science.gov (United States)

    Sauter, Cornelia; Dorn, Hans; Bahr, Achim; Hansen, Marie-Luise; Peter, Anita; Bajbouj, Malek; Danker-Hopfe, Heidi

    2011-04-01

    Results of studies on the possible effects of electromagnetic fields emitted by mobile phones on cognitive functions are contradictory, therefore, possible effects of long-term (7 h 15 min) electromagnetic field (EMF) exposure to handset-like signals of Global System for Mobile Communications (GSM) 900 and Wideband Code-Division Multiple Access (WCDMA) on attention and working memory were studied. The sample comprised 30 healthy male subjects (mean ± SD: 25.3 ± 2.6 years), who were tested on nine study days in which they were exposed to three exposure conditions (sham, GSM 900 and WCDMA) in a randomly assigned and balanced order. All tests were presented twice (morning and afternoon) on each study day within a fixed timeframe. Univariate comparisons revealed significant changes when subjects were exposed to GSM 900 compared to sham, only in the vigilance test. In the WCDMA exposure condition, one parameter in the vigilance and one in the test on divided attention were altered compared to sham. Performance in the selective attention test and the n-back task was not affected by GSM 900 or WCDMA exposure. Time-of-day effects were evident for the tests on divided and selective attention, as well as for working memory. After correction for multiple testing, only time-of-day effects remained significant in two tests, resulting in faster reactions in the afternoon trials. The results of the present study do not provide any evidence of an EMF effect on human cognition, but they underline the necessity to control for time of day. Copyright © 2010 Wiley-Liss, Inc.

  18. Quality of pharmacy-specific Medical Subject Headings (MeSH) assignment in pharmacy journals indexed in MEDLINE.

    Science.gov (United States)

    Minguet, Fernando; Salgado, Teresa M; van den Boogerd, Lucienne; Fernandez-Llimos, Fernando

    2015-01-01

    The Medical Subject Headings (MeSH) is the National Library of Medicine (NLM) controlled vocabulary for indexing articles. Inaccuracies in the MeSH thesaurus have been reported for several areas including pharmacy. To assess the quality of pharmacy-specific MeSH assignment to articles indexed in pharmacy journals. The 10 journals containing the highest number of articles published in 2012 indexed under the MeSH 'Pharmacists' were identified. All articles published over a 5-year period (2008-2012) in the 10 previously selected journals were retrieved from PubMed. MeSH terms used to index these articles were extracted and pharmacy-specific MeSH terms were identified. The frequency of use of pharmacy-specific MeSH terms was calculated across journals. A total of 6989 articles were retrieved from the 10 pharmacy journals, of which 328 (4.7%) were articles not fully indexed and therefore did not contain any MeSH terms assigned. Among the 6661 articles fully indexed, the mean number of MeSH terms was 10.1 (SD = 4.0), being 1.0 (SD = 1.3) considered as Major MeSH. Both values significantly varied across journals. The mean number of pharmacy-specific MeSH terms per article was 0.9 (SD = 1.2). A total of 3490 (52.4%) of the 6661 articles were indexed in pharmacy journals without a single pharmacy-specific MeSH. Of the total 67193 MeSH terms assigned to articles, on average 10.5% (SD = 13.9) were pharmacy-specific MeSH. A statistically significant different pattern of pharmacy-specific MeSH assignment was identified across journals (Kruskal-Wallis P MeSH terms to articles indexed in pharmacy journals can be improved to further enhance evidence gathering in pharmacy. Over half of the articles published in the top-10 journals publishing pharmacy literature were indexed without a single pharmacy-specific MeSH. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Electromagnetic Waves

    DEFF Research Database (Denmark)

    This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis...

  20. Relationships among head posture, pain intensity, disability and deep cervical flexor muscle performance in subjects with postural neck pain

    Directory of Open Access Journals (Sweden)

    Arun V. Subbarayalu, PhD

    2017-12-01

    Full Text Available Objectives: Information Technology (IT professionals working with computers gradually develop forward head posture and, as a result, these professionals are susceptible to several neck disorders. This study intended to reveal the relationships between pain intensity, disability, head posture and deep cervical flexor (DCF muscle performance in patients with postural neck pain. Methods: A cross-sectional study was conducted on 84 IT professionals who were diagnosed with postural neck pain. The participants were recruited with a random sampling approach. A Visual Analogue Scale (VAS, the Northwick Park Neck Pain Questionnaire (NPQ, the Modified Head Posture Spinal Curvature Instrument (MHPSCI, and the Stabilizer Pressure Biofeedback Unit were used to measure neck pain intensity, neck disability, head posture, and DCF muscle performance, respectively. Results: The Pearson correlation coefficient revealed a significantly strong positive relationship between the VAS and the NPQ (r = 0.734. The cranio-vertebral (CV angle was found to have a significantly negative correlation with the VAS (r = −0.536 and a weak negative correlation with the NPQ (r = −0.389. Conclusion: This study concluded that a smaller CV angle corresponded to greater neck pain intensity and disability. Furthermore, there is no significant relationship between CV angle and DCF muscle performance, indicating that head posture re-education through postural correction exercises would not completely correct the motor control deficits in DCF muscles. In addition, a suitable exercise regimen that exclusively targets the deep cervical flexor muscle to improve its endurance is warranted. Keywords: Craniovertebral angle, Disability deep cervical flexors muscle performance, Head posture, Postural neck pain

  1. Global visibility for global health: Is it time for a new descriptor in Medical Subject Heading (MeSH of MEDLINE/PubMed?

    Directory of Open Access Journals (Sweden)

    Ana Marušic´

    2013-06-01

    Full Text Available Despite a large body of research in global health (almost 9000 articles published in PubMed until 2012, the term “global health” is not included in the Medical Subject Headings (MeSH of the NLM – its controlled vocabulary thesaurus which NLM uses to index articles in MEDL INE. There are only 6 journals currently covered by PubMed which specialize in global health, including Journal of Global Health.

  2. Engineering electromagnetics

    CERN Document Server

    Ida, Nathan

    2015-01-01

    This book provides students with a thorough theoretical understanding of electromagnetic field equations and it also treats a large number of applications. The text is a comprehensive two-semester textbook. The work treats most topics in two steps – a short, introductory chapter followed by a second chapter with in-depth extensive treatment; between 10 to 30 applications per topic; examples and exercises throughout the book; experiments, problems  and summaries.   The new edition includes: updated end of chapter problems; a new introduction to electromagnetics based on behavior of charges; a new section on units; MATLAB tools for solution of problems and demonstration of subjects; most chapters include a summary. The book is an undergraduate textbook at the Junior level, intended for required classes in electromagnetics. It is written in simple terms with all details of derivations included and all steps in solutions listed. It requires little beyond basic calculus and can be used for self-study. The weal...

  3. A Remote-Controlled Airbag Device Can Improve Upper Airway Collapsibility by Producing Head Elevation With Jaw Closure in Normal Subjects Under Propofol Anesthesia.

    Science.gov (United States)

    Ishizaka, Satoru; Moromugi, Shunji; Kobayashi, Masato; Kajihara, Hiroki; Koga, Kazuya; Sugahara, Hirofumi; Ishimatsu, Takakazu; Kurata, Shinji; Kirkness, Jason P; Oi, Kumiko; Ayuse, Takao

    2014-01-01

    Continuous maintenance of an appropriate position of the mandible and head purely by manual manipulation is difficult, although the maneuver can restore airway patency during sleep and anesthesia. The aim of this paper was to examine the effect of head elevation with jaw closure using a remote-controlled airbag device, such as the airbag system, on passive upper airway collapsibility during propofol anesthesia. Seven male subjects were studied. Propofol infusion was used for anesthesia induction and maintenance, with a target blood propofol concentration of 1.5-2 [Formula: see text]g/ml. Nasal mask pressure ([Formula: see text]) was intermittently reduced to evaluate upper airway collapsibility (passive [Formula: see text]) and upstream resistance ([Formula: see text]) at three different head and jaw positions, jaw opening position in the supine position, jaw opening position in the sniffing position with 6-cm head elevation, and jaw closure at a 6-cm height sniffing position. The 6-cm height sniffing position with jaw closure was achieved by an airbag device that was attached to the subject's head-like headgear. Patient demographics, [Formula: see text] and [Formula: see text] in each condition were compared using one-way ANOVA with a post hoc Tukey test. [Formula: see text] was considered significant. We also confirmed the effects of our airbag device on improvement of upper airway collapsibility in three obstructive sleep apnea patients in a clinical study. The combination of 6-cm head elevation with jaw closure using the air-inflatable robotic airbag system decreased upper airway collapsibility ([Formula: see text]-cm H[Formula: see text]O) compared with the baseline position ([Formula: see text]-cm H[Formula: see text]O, [Formula: see text]). In the clinical study, there was improvement of upper airway obstruction in sleep apnea patients, including decreased apnea and hypopnea duration and increased the lowest level of oxygen saturation. We demonstrated that

  4. Effects of repeated snowboard exercise in virtual reality with time lags of visual scene behind body rotation on head stability and subjective slalom run performance in healthy young subjects.

    Science.gov (United States)

    Wada, Yoshiro; Nishiike, Suetaka; Kitahara, Tadashi; Yamanaka, Toshiaki; Imai, Takao; Ito, Taeko; Sato, Go; Matsuda, Kazunori; Kitamura, Yoshiaki; Takeda, Noriaki

    2016-11-01

    After repeated snowboard exercises in the virtual reality (VR) world with increasing time lags in trials 3-8, it is suggested that the adaptation to repeated visual-vestibulosomatosensory conflict in the VR world improved dynamic posture control and motor performance in the real world without the development of motion sickness. The VR technology was used and the effects of repeated snowboard exercise examined in the VR world with time lags between visual scene and body rotation on the head stability and slalom run performance during exercise in healthy subjects. Forty-two healthy young subjects participated in the study. After trials 1 and 2 of snowboard exercise in the VR world without time lag, trials 3-8 were conducted with 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 s time lags of the visual scene that the computer creates behind board rotation, respectively. Finally, trial 9 was conducted without time lag. Head linear accelerations and subjective slalom run performance were evaluated. The standard deviations of head linear accelerations in inter-aural direction were significantly increased in trial 8, with a time lag of 0.6 s, but significantly decreased in trial 9 without a time lag, compared with those in trial 2 without a time lag. The subjective scores of slalom run performance were significantly decreased in trial 8, with a time lag of 0.6 s, but significantly increased in trial 9 without a time lag, compared with those in trial 2 without a time lag. Motion sickness was not induced in any subjects.

  5. List-Mode PET Motion Correction Using Markerless Head Tracking: Proof-of-Concept With Scans of Human Subject

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Sullivan, Jenna M.; Mulnix, Tim

    2013-01-01

    was time-varying with long drift motions of up to 18 mm and regular step-wise motion of 1–6 mm. The evaluated measures were significantly better for motion-corrected images compared to no MC. The demonstrated system agreed with a commercial integrated system. Motion-corrected images were improved......A custom designed markerless tracking system was demonstrated to be applicable for positron emission tomography (PET) brain imaging. Precise head motion registration is crucial for accurate motion correction (MC) in PET imaging. State-of-the-art tracking systems applied with PET brain imaging rely...... on markers attached to the patient's head. The marker attachment is the main weakness of these systems. A healthy volunteer participating in a cigarette smoking study to image dopamine release was scanned twice for 2 h with $^{11}{\\rm C}$-racolopride on the high resolution research tomograph (HRRT) PET...

  6. Electromagnetic Waves

    OpenAIRE

    Blok, H.; van den Berg, P.M.

    2011-01-01

    This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis, material characterization, electromagnetic properties of plasma, analysis and applications of periodic structures and waveguide components, etc.

  7. Alcohol-associated acute head trauma in human subjects is associated with early deficits in serum ionized Mg and Ca.

    Science.gov (United States)

    Altura, B M; Memon, Z S; Altura, B T; Cracco, R Q

    1995-01-01

    Acute head trauma (AHT) (caused by motor vehicle accidents that did not produce loss of consciousness or observed brain lesions on CT scan, or falls) was found to result in early (1-8 h after injury) serum deficits in ionized magnesium (IMg2+) and ionized calcium (ICa2+) assessed with ion-selective electrodes (ISEs). Total Mg (TMg) and other electrolytes as well as serum biochemical analytes were all within the normal reference ranges. AHT patients with acute alcohol intoxication (BAC > or = 150 mg/dl) or alcohol abuse (BAC > 200 mg/dl) demonstrated deficits (15-35% less than normal) in IMg2+, but serum TMg levels were normal as were electrolytes and serum biochemical analytes. AHT patients with alcohol intoxication or alcohol abuse required hospitalization for 1-3 days prior to release, whereas AHT patients without alcohol intoxication were released in less than 24 h. The ICa2+/IMg2+ ratio, a sign of increased vascular tone and vascular reactivity, was significantly elevated in AHT patients with alcohol intoxication but not in AHT patients without alcohol intoxication or abuse. These serum divalent cation changes early after traumatic brain injury could be of considerable practicable diagnostic value in the assessment of alcohol-associated head injury. Use of ion-selective electrodes to accurately measure IMg2+ could serve as a logical basis for monitoring the response of the body to AHT.

  8. Development and validation of a numerical model of the swine head subjected to open-field blasts

    Science.gov (United States)

    Kalra, A.; Zhu, F.; Feng, K.; Saif, T.; Kallakuri, S.; Jin, X.; Yang, K.; King, A.

    2017-11-01

    A finite element model of the head of a 55-kg Yucatan pig was developed to calculate the incident pressure and corresponding intracranial pressure due to the explosion of 8 lb (3.63 kg) of C4 at three different distances. The results from the model were validated by comparing findings with experimentally obtained data from five pigs at three different blast overpressure levels: low (150 kPa), medium (275 kPa), and high (400 kPa). The peak values of intracranial pressures from numerical model at different locations of the brain such as the frontal, central, left temporal, right temporal, parietal, and occipital regions were compared with experimental values. The model was able to predict the peak pressure with reasonable percentage differences. The differences for peak incident and intracranial pressure values between the simulation results and the experimental values were found to be less than 2.2 and 29.3%, respectively, at all locations other than the frontal region. Additionally, a series of parametric studies shows that the intracranial pressure was very sensitive to sensor locations, the presence of air bubbles, and reflections experienced during the experiments. Further efforts will be undertaken to correlate the different biomechanical response parameters, such as the intracranial pressure gradient, stress, and strain results obtained from the validated model with injured brain locations once the histology data become available.

  9. Objective and subjective image quality of primary and recurrent squamous cell carcinoma on head and neck low-tube-voltage 80-kVp computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Scholtz, Jan-Erik; Kaup, Moritz; Kraft, Johannes; Noeske, Eva-Maria; Schulz, Boris; Burck, Iris; Kerl, J.M.; Bauer, Ralf W.; Lehnert, Thomas; Vogl, Thomas J.; Wichmann, Julian L. [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Scheerer, Friedrich [University Hospital Frankfurt, Department of Cranio-Maxillofacial and Plastic Facial Surgery, Frankfurt (Germany); Wagenblast, Jens [University Hospital Frankfurt, Department of Otolaryngology, Head and Neck Surgery, Frankfurt (Germany)

    2015-03-26

    To investigate low-tube-voltage 80-kVp computed tomography (CT) of head and neck primary and recurrent squamous cell carcinoma (SCC) regarding objective and subjective image quality. We retrospectively evaluated 65 patients (47 male, 18 female; mean age: 62.1 years) who underwent head and neck dual-energy CT (DECT) due to biopsy-proven primary (n = 50) or recurrent (n = 15) SCC. Eighty peak kilovoltage and standard blended 120-kVp images were compared. Attenuation and noise of malignancy and various soft tissue structures were measured. Tumor signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Subjective image quality was rated by three reviewers using 5-point grading scales regarding overall image quality, lesion delineation, image sharpness, and image noise. Radiation dose was assessed as CT dose index volume (CTDI{sub vol}). Interobserver agreement was calculated using intraclass correlation coefficient (ICC). Mean tumor attenuation (153.8 Hounsfield unit (HU) vs. 97.1 HU), SNR (10.7 vs. 8.3), CNR (8.1 vs. 4.8), and subjective tumor delineation (score, 4.46 vs. 4.13) were significantly increased (all P < 0.001) with 80-kVp acquisition compared to standard blended 120-kVp images. Noise of all measured structures was increased in 80-kVp acquisition (P < 0.001). Overall interobserver agreement was good (ICC, 0.86; 95 % confidence intervals: 0.82-0.89). CTDI{sub vol} was reduced by 48.7 % with 80-kVp acquisition compared to standard DECT (4.85 ± 0.51 vs. 9.94 ± 0.81 mGy cm, P < 0.001). Head and neck CT with low-tube-voltage 80-kVp acquisition provides increased tumor delineation, SNR, and CNR for CT imaging of primary and recurrent SCC compared to standard 120-kVp acquisition with an accompanying significant reduction of radiation exposure. (orig.)

  10. Survey of keyword adjustment of published articles medical subject headings in journal of mazandaran university of medical sciences (2009-2010).

    Science.gov (United States)

    Kabirzadeh, Azar; Siamian, Hasan; Abadi, Ebrahim Bagherian Farah; Saravi, Benyamin Mohseni

    2013-01-01

    NONE DECLARED. Keywords are the most important tools for Information retrieval. They are usually used for retrieval of articles based on contents of information reserved from printed and electronic resources. Retrieval of appropriate keywords from Medical Subject Headings (MeSH) can impact with exact, correctness and short time on information retrieval. Regarding the above mentioned matters, this study was done to compare the Latin keywords was in the articles published in the Journal of Mazandaran University of Medical Sciences. This is a descriptive study. The data were extracted from the key words of Englsih abstracts of articles published in the years 2009-2010 in the Journal of Mazandaran University of Medical Sciences by census method. Checklist of data collection is designed, based on research objectives and literature review which has face validity. Compliance rate in this study was to determine if the keywords cited in this article as a full subject of the main subject headings in a MeSH (Bold and the selected word) is a perfect adjustment. If keywords were cited in the article but the main heading is not discussed in the following main topics to be discussed with reference to See and See related it has considered has partial adjustment. Out of 148 articles published in 12 issues in proposed time of studying, 72 research papers were analyzed. The average numbers of authors in each article were 4 ± 1. Results showed that most of specialty papers 42 (58. 4%), belonging to the (Department of Clinical Sciences) School of Medicine, 11 (15.3%) Basic Science, 6(8.4%) Pharmacy, Nursing and Midwifery 5(6.9%), 4(5.5%) Health, paramedical Sciences 3(4.2%), and non medical article 1(1.3%) school of medicine. In general, results showed that 80 (30%) of key words have been used to complete the adjustment. Also, only 1(1.4%) had complete adjustment with all the MeSH key words and in 8 articles(11.4%) key words of had no adjustment with MeSH. The results showed that only

  11. Scored Patient-Generated Subjective Global Assessment, albumin and transferrin for nutritional assessment of gastrostomy fed head or neck cancer patients.

    Science.gov (United States)

    Correira Pereira, Marta Alexandra; Santos, Carla Adriana; Almeida Brito, José; Fonseca, Jorge

    2014-02-01

    Gastrostomy fed head or neck cancer patients frequently have impaired speech capacities. Enteral feeding teams frequently depend on laboratorial or anthropometrical parameters for nutritional assessment. In these patients, this study aimed to evaluate: (1) the practicability of Scored - Patient-Generated Subjective Global Assessment (PG-SGA); (2) their nutritional status using the Scored-PG-SGA; (3) association of serum albumin and transferrin values to the nutritional status rating using PG-SGA. On adult outpatients with head or neck cancer under prolonged (> 1 month) gastrostomy feeding, Scored-PGSGA, albumin and transferrin were evaluated during the same appointment. Scored-PG-SGA was easily feasible in 42 patients, even in patients with speech difficulties. Twenty-five patients were moderately/severely undernourished (PG-SGA/B+C). Scored-PG-SGA rated 41 patients as ≥ 2, thus needing nutritional/ pharmacologic intervention. Albumin was low in 13 patients. Transferrin was low in 19 patients. Average albumin and transferrin in moderately/severely undernourished patients (PG-SGA/B+C) was significantly lower than in well-nourished (PG-SGA/A). There was association between Scored- PG-SGA rating, albumin and transferrin. In PEG fed head or neck cancer patients, PGSGA was practicable and useful, even in patients with impaired speaking skills. Most patients displayed moderate/severe malnutrition (PG-SGA/B+C). Scored-PG-SGA rated 41 patients as needing for nutritional/pharmacological intervention. Scored-PG-SGA should be systematically included in the evaluation of these patients. In these patients, albumin and transferrin levels showed relation with Scored-PG-SGA and should be considered as nutritional biomarkers. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  12. Incidence of head and neck squamous cell carcinoma among subjects at high risk of lung cancer: results from the Pittsburgh Lung Screening Study.

    Science.gov (United States)

    Dixit, Ronak; Weissfeld, Joel L; Wilson, David O; Balogh, Paula; Sufka, Pamela; Siegfried, Jill M; Grandis, Jennifer R; Diergaarde, Brenda

    2015-05-01

    Earlier detection and diagnosis of head and neck squamous cell carcinoma (HNSCC) should lead to improved outcomes. However, to the authors' knowledge, no effective screening strategy has been identified to date. In the current study, the authors evaluated whether it would be useful to screen subjects targeted for lung cancer screening for HNSCC as well. Medical records, death certificates, and cancer registry and questionnaire data were used to determine the number of observed incident HNSCC cases in the Pittsburgh Lung Screening Study (PLuSS), a cohort of current and former smokers aged ≥50 years with a ≥12.5 pack-year smoking history. The expected number of cases was estimated using stratum-specific incidence rates obtained from Surveillance, Epidemiology, and End Results data for 2000 through 2011. The standardized incidence ratio was calculated to examine the difference between the observed and expected number of cases. Of the 3587 at-risk participants in the PLuSS, 23 (0.64%) developed HNSCC over a total of 32,201 person-years of follow-up. This finding was significantly higher than expected based on incidence rates obtained from the Surveillance, Epidemiology, and End Results program (13.70 cases expected; standardized incidence ratio, 1.68 [95% confidence interval, 1.06-2.52]). The excess burden of HNSCC in the PLuSS was 28.9 cases per 100,000 person-years. Observed incident cases were significantly more often male, had started smoking at a younger age, smoked more per day, and had more pack-years of smoking than the rest of the PLuSS at-risk participants. The results of the current study provide a rationale for offering head and neck cancer screening along with computed tomography screening for lung cancer. Randomized controlled trials that assess the effectiveness of adding examination of the head and neck area to lung cancer screening programs are warranted. © 2015 American Cancer Society.

  13. Experimental Investigation of Cavitation as a Possible Damage Mechanism in Blast-Induced Traumatic Brain Injury in Post-Mortem Human Subject Heads.

    Science.gov (United States)

    Salzar, Robert S; Treichler, Derrick; Wardlaw, Andrew; Weiss, Greg; Goeller, Jacques

    2017-04-15

    The potential of blast-induced traumatic brain injury from the mechanism of localized cavitation of the cerebrospinal fluid (CSF) is investigated. While the mechanism and criteria for non-impact blast-induced traumatic brain injury is still unknown, this study demonstrates that local cavitation in the CSF layer of the cranial volume could contribute to these injuries. The cranial contents of three post-mortem human subject (PMHS) heads were replaced with both a normal saline solution and a ballistic gel mixture with a simulated CSF layer. Each were instrumented with multiple pressure transducers and placed inside identical shock tubes at two different research facilities. Sensor data indicates that cavitation may have occurred in the PMHS models at pressure levels below those for a 50% risk of blast lung injury. This study points to skull flexion, the result of the shock wave on the front of the skull leading to a negative pressure in the contrecoup, as a possible mechanism that contributes to the onset of cavitation. Based on observation of intracranial pressure transducer data from the PMHS model, cavitation onset is thought to occur from approximately a 140 kPa head-on incident blast.

  14. Reduced Sympathetic Response to Head-Up Tilt in Subjects with Mild Cognitive Impairment or Mild Alzheimer's Dementia

    Directory of Open Access Journals (Sweden)

    Marte Rognstad Mellingsæter

    2015-03-01

    Full Text Available Background: Hemodynamic control was compared in patients with mild cognitive impairment (MCI or mild Alzheimer's dementia (AD as well as in healthy elderly subjects. Methods: Noninvasive, continuous hemodynamic recordings were obtained from 14 patients and 48 controls during supine rest (tilt of 30 and 70°. Cardiac output, end-diastolic volume, total peripheral resistance, heart rate variability (HRV, systolic blood pressure variability (SBPV, and baroreceptor sensitivity were calculated. Results: At 70° tilt, the HRV indices differed significantly, with higher high-frequency (HF variability as well as lower low-frequency (LF variability and LF/HF ratios in the patients. The patients had significantly lower SBPV in the LF range at 30° tilt. Conclusions: The results indicate a poorer sympathetic response to orthostatic stress in MCI and mild AD.

  15. Analysis by NASA's VESGEN Software of Retinal Blood Vessels in Human Subjects Undergoing Head-Down Tilt During 70-Day Bed Rest

    Science.gov (United States)

    Vyas, Ruchi J.; Murray, Matthew C.; Predovic, Marina; Lim, Shiyin; Askin, Kayleigh N.; Vizzeri, Gianmarco; Taibbi, Giovanni; Mason, Sara Stroble; Zanello, Susana B.; Young, Millenia; hide

    2017-01-01

    Significant risks for visual impairment associated with increased intracranial pressure (VIIP) are incurred by microgravity spaceflight, especially long-duration missions [1]. We hypothesize that microgravity-induced fluid shifts result in pathological changes within blood vessels of the retina that precede development of visual and other ocular impairments. Potential contributions of retinal vascular remodeling to VIIP etiology are therefore being investigated for two studies in 30deg infrared (IR) Heidelberg Spectralis(Registered Trademark) images with NASA's innovative VESsel GENeration Analysis (VESGEN) software [2,3]. The retrospective studies include: (1) before, during and after (pre, mid and post) 6º head-down tilt (HDT) in human subjects during 70 days of bed rest, and (2) before and after missions to the International Space Station (ISS) by U.S. crew members. Results for both studies are almost complete. A preliminary example for HDT is described below.

  16. Citation Analysis using the Medline Database at the Web of Knowledge: Searching "Times Cited" with Medical Subject Headings (MeSH)

    CERN Document Server

    Leydesdorff, Loet

    2012-01-01

    Citation analysis of documents retrieved from the Medline database (at the Web of Knowledge) has been possible only on a case-by-case basis. A technique is here developed for citation analysis in batch mode using both Medical Subject Headings (MeSH) at the Web of Knowledge and the Science Citation Index at the Web of Science. This freeware routine is applied to the case of "Brugada Syndrome," a specific disease and field of research (since 1992). The journals containing these publications are attributed to Web-of-Science Categories other than "Cardiac and Cardiovascular Systems"), perhaps because of the possibility of genetic testing for this syndrome in the clinic. With this routine, all the instruments available for citation analysis can be used on the basis of MeSH terms.

  17. Head Start.

    Science.gov (United States)

    Greenman, Geri

    2000-01-01

    Discusses an art project in which students created drawings of mop heads. Explains that the approach of drawing was more important than the subject. States that the students used the chiaroscuro technique, used by Rembrandt and Caravaggio, in which light appears out of the darkness. (CMK)

  18. Electromagnetic compatibility engineering

    CERN Document Server

    Ott, Henry W

    2009-01-01

    Praise for Noise Reduction Techniques IN electronic systems ""Henry Ott has literally 'written the book' on the subject of EMC. . . . He not only knows the subject, but has the rare ability to communicate that knowledge to others.""-EE Times Electromagnetic Compatibility Engineering is a completely revised, expanded, and updated version of Henry Ott's popular book Noise Reduction Techniques in Electronic Systems. It reflects the most recent developments in the field of electromagnetic compatibility (EMC) and noise reduction¿and their practical applications t

  19. Compensating for literature annotation bias when predicting novel drug-disease relationships through Medical Subject Heading Over-representation Profile (MeSHOP) similarity.

    Science.gov (United States)

    Cheung, Warren A; Ouellette, B F Francis; Wasserman, Wyeth W

    2013-01-01

    Using annotations to the articles in MEDLINE®/PubMed®, over six thousand chemical compounds with pharmacological actions have been tracked since 1996. Medical Subject Heading Over-representation Profiles (MeSHOPs) quantitatively leverage the literature associated with biological entities such as diseases or drugs, providing the opportunity to reposition known compounds towards novel disease applications. A MeSHOP is constructed by counting the number of times each medical subject term is assigned to an entity-related research publication in the MEDLINE database and calculating the significance of the count by comparing against the count of the term in a background set of publications. Based on the expectation that drugs suitable for treatment of a disease (or disease symptom) will have similar annotation properties to the disease, we successfully predict drug-disease associations by comparing MeSHOPs of diseases and drugs. The MeSHOP comparison approach delivers an 11% improvement over bibliometric baselines. However, novel drug-disease associations are observed to be biased towards drugs and diseases with more publications. To account for the annotation biases, a correction procedure is introduced and evaluated. By explicitly accounting for the annotation bias, unexpectedly similar drug-disease pairs are highlighted as candidates for drug repositioning research. MeSHOPs are shown to provide a literature-supported perspective for discovery of new links between drugs and diseases based on pre-existing knowledge.

  20. Cited references and Medical Subject Headings (MeSH) as two different knowledge representations: clustering and mappings at the paper level.

    Science.gov (United States)

    Leydesdorff, Loet; Comins, Jordan A; Sorensen, Aaron A; Bornmann, Lutz; Hellsten, Iina

    2016-01-01

    For the biomedical sciences, the Medical Subject Headings (MeSH) make available a rich feature which cannot currently be merged properly with widely used citing/cited data. Here, we provide methods and routines that make MeSH terms amenable to broader usage in the study of science indicators: using Web-of-Science (WoS) data, one can generate the matrix of citing versus cited documents; using PubMed/MEDLINE data, a matrix of the citing documents versus MeSH terms can be generated analogously. The two matrices can also be reorganized into a 2-mode matrix of MeSH terms versus cited references. Using the abbreviated journal names in the references, one can, for example, address the question whether MeSH terms can be used as an alternative to WoS Subject Categories for the purpose of normalizing citation data. We explore the applicability of the routines in the case of a research program about the amyloid cascade hypothesis in Alzheimer's disease. One conclusion is that referenced journals provide archival structures, whereas MeSH terms indicate mainly variation (including novelty) at the research front. Furthermore, we explore the option of using the citing/cited matrix for main-path analysis as a by-product of the software.

  1. Electromagnetic Attraction.

    Science.gov (United States)

    Milson, James L.

    1990-01-01

    Three activities involving electromagnetism are presented. Discussed are investigations involving the construction of an electromagnet, the effect of the number of turns of wire in the magnet, and the effect of the number of batteries in the circuit. Extension activities are suggested. (CW)

  2. Research in Support of Electromagnetic Detection and Jamming of Improvised Explosive Devices

    Science.gov (United States)

    2009-11-15

    electromagnetic radiation . 20Improvised Explosive Devices (IEDs); electromagnetic detection of IEDs; electromagnetic propagation over earth; Galerkin method; EMF method; TEM horn antennas; transmission-line antennas ...SUBJECT TERMS Improvised Explosive Devices (IEDs); electromagnetic detection of IEDs; electromagnetic propagation over earth; Galerkin method; EMF ...wires and give pointers to published material relevant to the analysis of health effects of exposure to electromagnetic radiation . (a) Papers

  3. Electromagnetic interactions

    CERN Document Server

    Bosanac, Slobodan Danko

    2016-01-01

    This book is devoted to theoretical methods used in the extreme circumstances of very strong electromagnetic fields. The development of high power lasers, ultrafast processes, manipulation of electromagnetic fields and the use of very fast charged particles interacting with other charges requires an adequate theoretical description. Because of the very strong electromagnetic field, traditional theoretical approaches, which have primarily a perturbative character, have to be replaced by descriptions going beyond them. In the book an extension of the semi-classical radiation theory and classical dynamics for particles is performed to analyze single charged atoms and dipoles submitted to electromagnetic pulses. Special attention is given to the important problem of field reaction and controlling dynamics of charges by an electromagnetic field.

  4. Tesauros y listas de epígrafes: ¿hacia una integración? Thesauri and list of subject headings: towards an integration?

    Directory of Open Access Journals (Sweden)

    Ana María Martínez

    2003-12-01

    Full Text Available Se analizan las semejanzas y diferencias entre los tesauros y las listas de epígrafes, tomando en cuenta el plan de revisión 2003 de la norma estadounidense Z39.19. Esta norma pretende establecer nuevas directrices para todo tipo de vocabulario controlado, en relación con su utilización con nuevas tecnologías. Se concluye que, en efecto, es muy importante revisar toda la normativa referida a los vocabularios controlados, particularmente las de alcance internacional, pero al mismo tiempo se hace necesario tener sumo cuidado en mantener un riguroso control de la terminología, una correcta definición de las relaciones jerárquicas y asociativas y promover la poscoordinación gestionada, en lo posible, mediante sistemas facetados y computarizados.The similarities and differences between thesauri and the lists of subject headings are analyzed, taking into account the work plan for the 2003 revision of the US standard Z39.19. This standard pretends to establish new guidelines for all types of controlled vocabulary in relation to their use with new technologies. We conclude that it is very important to review all the standards for controlled vocabulary, particularly those with international scope, but at the same time, it is necessary to be very careful in maintaining a rigorous control of terminology; a correct definition of hierarchical and associative relationships, and to promote the postcordination, managed, if possible, in faceted and computerized systems.

  5. Engineering electromagnetics

    CERN Document Server

    Thomas, David T; Hartnett, James P; Hughes, William F

    1973-01-01

    The applications involving electromagnetic fields are so pervasive that it is difficult to estimate their contribution to the industrial output: generation of electricity, power transmission lines, electric motors, actuators, relays, radio, TV and microwave transmission and reception, magnetic storage, and even the mundane little magnet used to hold a paper note on the refrigerator are all electromagnetic in nature. One would be hard pressed to find a device that works without relaying on any electromagnetic principle or effect. This text provides a good theoretical understanding of the electromagnetic field equations but also treats a large number of applications. In fact, no topic is presented unless it is directly applicable to engineering design or unless it is needed for the understanding of another topic. In electrostatics, for example, the text includes discussions of photocopying, ink-jet printing, electrostatic separation and deposition, sandpaper production, paint spraying, and powder coating. In ma...

  6. Electromagnetic Landscape

    DEFF Research Database (Denmark)

    Cermak, Daniel; Okutsu, Ayaka; Jørgensen, Stina Marie Hasse

    2015-01-01

    Daniel Cermak-Sassenrath, Ayaka Okutsu, Stina Hasse. Electromagnetic Landscape - In-between Signal, Noise and Environment. Installation and artist talk. 21th International Symposium on Electronic Art (ISEA) 2015, Vancouver, CAN, Aug 14-18, 2015.......Daniel Cermak-Sassenrath, Ayaka Okutsu, Stina Hasse. Electromagnetic Landscape - In-between Signal, Noise and Environment. Installation and artist talk. 21th International Symposium on Electronic Art (ISEA) 2015, Vancouver, CAN, Aug 14-18, 2015....

  7. [The ultrastructural manifestations of the regenerative processes in the Sertoli cells under the action of low-intensity electromagnetic radiation in the rats subjected to stress].

    Science.gov (United States)

    Korolev, Iu N; Geniatulina, M S; Nikulina, L A; Mikhaĭlik, L V

    2015-01-01

    The experiments on the outbred female rats using the electron microscopic technique have demonstrated that the application of ultrahigh frequency low-intensity electromagnetic radiation (LIEMR) with a flux density below 1 mCW/Cm2 and a frequency of approximately 1,000 MHz in the regime of primary prophylaxis and therapeutic-preventive action suppressed the development of the post-stress pathological ultrastructural changes and increased the activity of the regenerative processes in the Sertoli cells. It was shown that the developing adaptive and compensatory changes in the Sertoli cells most frequently involve the energy-producing structures (mitochondria) that undergo the enlargement of their average and total dimensions. Simultaneously, the amount of granular endoplasmic reticulum and the number of ribosomes increased while the intracellular links between the organelles strengthened and the reserve potential of the cells improved. It is concluded that the observed effects may be due to the action of both local and systemic regulation mechanisms.

  8. A Determination of the Risk of Intentional and Unintentional Electromagnetic Radiation Emitters Degrading Installed Components in Closed Electromagnetic Environments

    Science.gov (United States)

    2015-06-01

    shielding and low power technologies is recommended. 14. SUBJECT TERMS Systems engineering, wireless, risk, electromagnetic, enclosed 15. NUMBER...properly determine the overall risk to at-risk equipment. Until that occurs, incorporating new methods of shielding and low power technologies is...electromagnetic EMC electromagnetic compatibility EMI electromagnetic interference FFBD functional flow block diagram FM frequency modulation LAN local

  9. A data mining approach to selecting herbs with similar efficacy: Targeted selection methods based on medical subject headings (MeSH).

    Science.gov (United States)

    Yea, Sang-Jun; Seong, BoSeok; Jang, Yunji; Kim, Chul

    2016-04-22

    Natural products have long been the most important source of ingredients in the discovery of new drugs. Moreover, since the Nagoya Protocol, finding alternative herbs with similar efficacy in traditional medicine has become a very important issue. Although random selection is a common method of finding ethno-medicinal herbs of similar efficacy, it proved to be less effective; therefore, this paper proposes a novel targeted selection method using data mining approaches in the MEDLINE database in order to identify and select herbs with a similar degree of efficacy. From among sixteen categories of medical subject headings (MeSH) descriptors, three categories containing terms related to herbal compounds, efficacy, toxicity, and the metabolic process were selected. In order to select herbs of similar efficacy in a targeted way, we adopted the similarity measurement method based on MeSH. In order to evaluate the proposed algorithm, we built up three different validation datasets which contain lists of original herbs and corresponding medicinal herbs of similar efficacy. The average area under curve (AUC) of the proposed algorithm was found to be about 500% larger than the random selection method. We found that the proposed algorithm puts more hits at the front of the top-10 list than the random selection method, and precisely discerns the efficacy of the herbs. It was also found that the AUC of the experiments either remained the same or increased slightly in all three validation datasets as the search range was increased. This study reveals and proves that the proposed algorithm is significantly more accurate and efficient in finding alternative herbs of similar efficacy than the random selection method. As such, it is hoped that this approach will be used in diverse applications in the ethno-pharmacology field. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  10. Using MeSH (medical subject headings) to enhance PubMed search strategies for evidence-based practice in physical therapy.

    Science.gov (United States)

    Richter, Randy R; Austin, Tricia M

    2012-01-01

    Evidence-based practice (EBP) is an important paradigm in health care. Physical therapists report lack of knowledge and time constraints as barriers to EBP. The purpose of this technical report is to illustrate how Medical Subject Headings (MeSH), a controlled vocabulary thesaurus of indexing terms, is used to efficiently search MEDLINE, the largest component of PubMed. Using clinical questions, this report illustrates how search terms common to physical therapist practice do or do not map to appropriate MeSH terms. A PubMed search strategy that takes advantage of text words and MeSH terms is provided. A search of 139 terms and 13 acronyms was conducted to determine whether they appropriately mapped to a MeSH term. The search results were categorized into 1 of 5 outcomes. Nearly half (66/139) of the search terms mapped to an appropriate MeSH term (outcome 1). When a search term did not appropriately map to a MeSH term, it was entered into the MeSH database to search for an appropriate MeSH term. Twenty-one appropriate MeSH terms were found (outcomes 2 and 4), and there were 52 search terms for which an appropriate MeSH term was not found (outcomes 3 and 5). Nearly half of the acronyms did not map to an appropriate MeSH term, and an appropriate MeSH term was not found in the database. The results are based on a limited number of search terms and acronyms. Understanding how search terms map to MeSH terms and using the PubMed search strategy can enable physical therapists to take full advantage of available MeSH terms and should result in more-efficient and better-informed searches.

  11. Intracranial hemorrhage alters scalp potential distribution in bioimpedance cerebral monitoring: Preliminary results from FEM simulation on a realistic head model and human subjects.

    Science.gov (United States)

    Atefi, Seyed Reza; Seoane, Fernando; Kamalian, Shervin; Rosenthal, Eric S; Lev, Michael H; Bonmassar, Giorgio

    2016-02-01

    Current diagnostic neuroimaging for detection of intracranial hemorrhage (ICH) is limited to fixed scanners requiring patient transport and extensive infrastructure support. ICH diagnosis would therefore benefit from a portable diagnostic technology, such as electrical bioimpedance (EBI). Through simulations and patient observation, the authors assessed the influence of unilateral ICH hematomas on quasisymmetric scalp potential distributions in order to establish the feasibility of EBI technology as a potential tool for early diagnosis. Finite element method (FEM) simulations and experimental left-right hemispheric scalp potential differences of healthy and damaged brains were compared with respect to the asymmetry caused by ICH lesions on quasisymmetric scalp potential distributions. In numerical simulations, this asymmetry was measured at 25 kHz and visualized on the scalp as the normalized potential difference between the healthy and ICH damaged models. Proof-of-concept simulations were extended in a pilot study of experimental scalp potential measurements recorded between 0 and 50 kHz with the authors' custom-made bioimpedance spectrometer. Mean left-right scalp potential differences recorded from the frontal, central, and parietal brain regions of ten healthy control and six patients suffering from acute/subacute ICH were compared. The observed differences were measured at the 5% level of significance using the two-sample Welch t-test. The 3D-anatomically accurate FEM simulations showed that the normalized scalp potential difference between the damaged and healthy brain models is zero everywhere on the head surface, except in the vicinity of the lesion, where it can vary up to 5%. The authors' preliminary experimental results also confirmed that the left-right scalp potential difference in patients with ICH (e.g., 64 mV) is significantly larger than in healthy subjects (e.g., 20.8 mV; P potential distributions. Pilot clinical observations with the authors

  12. A Prediction of Response of the Head and Neck of the U.S. Adult Military Population to Dynamic Impact Acceleration from Selected Dynamic Test Subjects.

    Science.gov (United States)

    1976-05-01

    It noceeawy and )Aettfi O haack mombe) Dynamic Response of Head and Neck Physical Characteristics of Head and NecK Mathematical Model Simulationj...response of these volunteers to -Gx sled acca’eratioa at 6 and 15 G’s. Procedures used for comuting the various prameter vilues w-4 coeprisons between...may be used with . mathematical modeling techniques in order to extend and project the NAMRL dynamic response results to the general adult U.S

  13. Classical electromagnetism in a nutshell

    CERN Document Server

    Garg, Anupam

    2012-01-01

    This graduate-level physics textbook provides a comprehensive treatment of the basic principles and phenomena of classical electromagnetism. While many electromagnetism texts use the subject to teach mathematical methods of physics, here the emphasis is on the physical ideas themselves. Anupam Garg distinguishes between electromagnetism in vacuum and that in material media, stressing that the core physical questions are different for each. In vacuum, the focus is on the fundamental content of electromagnetic laws, symmetries, conservation laws, and the implications for phenomena such as radiation and light. In material media, the focus is on understanding the response of the media to imposed fields, the attendant constitutive relations, and the phenomena encountered in different types of media such as dielectrics, ferromagnets, and conductors. The text includes applications to many topical subjects, such as magnetic levitation, plasmas, laser beams, and synchrotrons.

  14. Electromagnetic foundations of electrical engineering

    CERN Document Server

    Faria, J A Brandao

    2008-01-01

    The applications of electromagnetic phenomena within electrical engineering have been evolving and progressing at a fast pace. In contrast, the underlying principles have been stable for a long time and are not expected to undergo any changes. It is these electromagnetic field fundamentals that are the subject of discussion in this book with an emphasis on basic principles, concepts and governing laws that apply across the electrical engineering discipline. Electromagnetic Foundations of Electrical Engineering begins with an explanation of Maxwell's equations, from which the fundament

  15. Electromagnetic Landscape

    DEFF Research Database (Denmark)

    Cermak, Daniel; Okutsu, Ayaka; Hasse, Stina

    2015-01-01

    Electromagnetic Landscape demonstrates in direct, tangible and immediate ways effects of the disruption of the familiar. An ubiquitous technological medium, FM radio, is turned into an alien and unfamiliar one. Audience participation, the environment, radio signals and noise create a site...

  16. Electromagnetic Fields

    Science.gov (United States)

    ... cancers. Studies in adults did not prove that EMF exposure causes cancer. Some people worry that wireless and cellular phones cause cancer or other health problems. The phones do give off radio-frequency energy (RF), a form of electromagnetic radiation. So far, scientific evidence has not found a ...

  17. Explanations, Education, and Electromagnetic Fields.

    Science.gov (United States)

    Friedman, Sharon M.

    Explaining complex scientific and environmental subjects in the mass media is difficult to do, particularly under such constraints as short deadlines and lack of space or time. When a scientific controversy and human health risk are involved, this becomes an even harder task to accomplish. The subject of electromagnetic fields (EMF) involves…

  18. Computational Electromagnetics

    CERN Document Server

    Rylander, Thomas; Bondeson, Anders

    2013-01-01

    Computational Electromagnetics is a young and growing discipline, expanding as a result of the steadily increasing demand for software for the design and analysis of electrical devices. This book introduces three of the most popular numerical methods for simulating electromagnetic fields: the finite difference method, the finite element method and the method of moments. In particular it focuses on how these methods are used to obtain valid approximations to the solutions of Maxwell's equations, using, for example, "staggered grids" and "edge elements." The main goal of the book is to make the reader aware of different sources of errors in numerical computations, and also to provide the tools for assessing the accuracy of numerical methods and their solutions. To reach this goal, convergence analysis, extrapolation, von Neumann stability analysis, and dispersion analysis are introduced and used frequently throughout the book. Another major goal of the book is to provide students with enough practical understan...

  19. Electromagnetic Reciprocity.

    Energy Technology Data Exchange (ETDEWEB)

    Aldridge, David F.

    2014-11-01

    A reciprocity theorem is an explicit mathematical relationship between two different wavefields that can exist within the same space - time configuration. Reciprocity theorems provi de the theoretical underpinning for mod ern full waveform inversion solutions, and also suggest practical strategies for speed ing up large - scale numerical modeling of geophysical datasets . In the present work, several previously - developed electromagnetic r eciprocity theorems are generalized to accommodate a broader range of medi um, source , and receiver types. Reciprocity relations enabling the interchange of various types of point sources and point receivers within a three - dimensional electromagnetic model are derived. Two numerical modeling algorithms in current use are successfully tested for adherence to reciprocity. Finally, the reciprocity theorem forms the point of departure for a lengthy derivation of electromagnetic Frechet derivatives. These mathe matical objects quantify the sensitivity of geophysical electromagnetic data to variatio ns in medium parameters, and thus constitute indispensable tools for solution of the full waveform inverse problem. ACKNOWLEDGEMENTS Sandia National Labor atories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000. Signif icant portions of the work reported herein were conducted under a Cooperative Research and Development Agreement (CRADA) between Sandia National Laboratories (SNL) and CARBO Ceramics Incorporated. The author acknowledges Mr. Chad Cannan and Mr. Terry Pa lisch of CARBO Ceramics, and Ms. Amy Halloran, manager of SNL's Geophysics and Atmospheric Sciences Department, for their interest in and encouragement of this work. Special thanks are due to Dr . Lewis C. Bartel ( recently retired from Sandia National Labo ratories

  20. Electromagnetic theory for electromagnetic compatibility engineers

    CERN Document Server

    Toh, Tze-Chuen

    2013-01-01

    Engineers and scientists who develop and install electronic devices and circuits need to have a solid understanding of electromagnetic theory and the electromagnetic behavior of devices and circuits. In particular, they must be well-versed in electromagnetic compatibility, which minimizes and controls the side effects of interconnected electric devices. Designed to entice the practical engineer to explore some worthwhile mathematical methods, and to reorient the theoretical scientist to industrial applications, Electromagnetic Theory for Electromagnetic Compatibility Engineers is based on the

  1. Resting-state networks in healthy adult subjects: a comparison between a 32-element and an 8-element phased array head coil at 3.0 Tesla.

    Science.gov (United States)

    Paolini, Marco; Keeser, Daniel; Ingrisch, Michael; Werner, Natalie; Kindermann, Nicole; Reiser, Maximilian; Blautzik, Janusch

    2015-05-01

    Little research exists on the influence of a magnetic resonance imaging (MRI) head coil's channel count on measured resting-state functional connectivity. To compare a 32-element (32ch) and an 8-element (8ch) phased array head coil with respect to their potential to detect functional connectivity within resting-state networks. Twenty-six healthy adults (mean age, 21.7 years; SD, 2.1 years) underwent resting-state functional MRI at 3.0 Tesla with both coils using equal standard imaging parameters and a counterbalanced design. Independent component analysis (ICA) at different model orders and a dual regression approach were performed. Voxel-wise non-parametric statistical between-group contrasts were determined using permutation-based non-parametric inference. Phantom measurements demonstrated a generally higher image signal-to-noise ratio using the 32ch head coil. However, the results showed no significant differences between corresponding resting-state networks derived from both coils (p coil does not offer any significant advantages in detecting ICA-based functional connectivity within RSNs. © The Foundation Acta Radiologica 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  2. Electromagnet. Elektromagnet

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Amaya, N.; Weiss, F.; Schmitt, A.

    1991-04-18

    An electromagnet, particularly for use in switching valves for the direct control of a fuel injection quantity on fuel injection pumps, has a magnet pot (25) made of soft magnetic material, an annular excitation coil (30) and a magnet armature (29), which is situated with a working air gap in front of the magnet pot (25). To improve the dynamic behaviour of the electromagnet (20), ie: to achieve extremely low switching times with simple manufacture of the magnetic circuit, the magnet pot (25) and/or the magnet armature (29) made as a solid part is provided with an even number of at least four radial slots (41), which pass through the magnet pot (25) or the magnet armature (29) over their whole axial length. Successive radial slots (41a, 41b) extend alternately from the outside or from the inside jacket surface (311 or 321) to near the inside or the outside jacket surface (321 or 311) respectively and end there, always leaving a bar of material (42 or 43).

  3. Electromagnetic microactuators

    Science.gov (United States)

    Büttgenbach, S.; Al-Halhouli, A. T.; Feldmann, M.; Seidemann, V.; Waldschik, A.

    2013-05-01

    High precision microactuators have become key elements for many applications of MEMS, for example for positioning and handling systems as well as for microfluidic devices. Electromagnetic microactuators exhibit considerable benefits such as high forces, large deflections, low input impedances and thus, the involvement of only low voltages. Most of the magnetic microactuators developed so far are based on the variable reluctance principle and use soft magnetic materials. Since the driving force of such actuators is proportional to their volume, they require structures with rather great heights and aspect ratios. Therefore, the development of new photo resists, which allow UV exposure of thick layers of resist, has been essential for the advancement of variable reluctance microactuators. On the other hand, hard magnetic materials have the potential for larger forces and larger deflections. Accordingly, polymer magnets, in which micro particles of hard magnetic material are suspended in a polymer matrix, have been used to fabricate permanent magnet microactuators. In this paper we give an overview of sophisticated electromagnetic microactuators which have been developed in our laboratory in the framework of the Collaborative Research Center "Design and Manufacturing of Active Microsystems". In particular, concept, fabrication and test of variable reluctance micro stepper motors, of permanent magnet synchronous micromotors and of microactuators based on the Lorentz force principle will be described. Special emphasis will be given to applications in lab-on-chip systems.

  4. Effect of 1% Inspired CO2 During Head-Down Tilt on Ocular Structures, Cerebral Blood Flow, and Visual Acuity in Healthy Human Subjects

    Science.gov (United States)

    Laurie, S. S.; Hu, X.; Lee, S. M. C.; Martin, D. S.; Phillips, T. R.; Ploutz-Snyder, R.; Smith, S. M.; Stenger, M. B.; Taibbi, G.; Zwart, S. R.; hide

    2016-01-01

    The cephalad fluid shift induced by microgravity has been hypothesized to elevate intracranial pressure (ICP) and contribute to the development of the visual impairment/intracranial pressure (VIIP) syndrome experienced by many astronauts during and after long-duration space flight. In addition, elevated ambient partial pressure of carbon dioxide (PCO2) on the International Space Station (ISS) has also been hypothesized to contribute to the development of VIIP. We seek to determine if an acute, mild CO2 exposure, similar to that occurring on the ISS, combined with the cephalad fluid shift induced by head-down tilt will induce ophthalmic and ICP changes consistent with the VIIP syndrome.

  5. Understanding electromagnetic effects using printed circuit board demos

    NARCIS (Netherlands)

    Buesink, Frederik Johannes Karel; Leferink, Frank Bernardus Johannes

    2009-01-01

    Electromagnetic fields are considered by many students as a difficult subject. Unwanted electromagnetic fields are even tougher for students. We have developed many experiments as demonstrations (demos) to show the effect of electromagnetic fields in real life products. This paper gives a brief

  6. Educating electromagnetic effects using printed circuit board demos

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    2009-01-01

    Electromagnetic fields are considered by many students as a difficult subject. Unwanted electromagnetic fields are even tougher for students. We have developed many experiments as demonstrations (demos) to show the effect of electromagnetic fields in real life products. This paper gives an overview

  7. Method and apparatus for measuring electromagnetic radiation

    Science.gov (United States)

    Been, J. F. (Inventor)

    1973-01-01

    An apparatus and method are described in which the capacitance of a semiconductor junction subjected to an electromagnetic radiation field is utilized to indicate the intensity or strength of the radiation.

  8. Electromagnetic reciprocity in antenna theory

    CERN Document Server

    Stumpf, Martin

    2018-01-01

    The reciprocity theorem is among the most intriguing concepts in wave field theory and has become an integral part of almost all standard textbooks on electromagnetic (EM) theory. This book makes use of the theorem to quantitatively describe EM interactions concerning general multiport antenna systems. It covers a general reciprocity-based description of antenna systems, their EM scattering properties, and further related aspects. Beginning with an introduction to the subject, Electromagnetic Reciprocity in Antenna Theory provides readers first with the basic prerequisites before offering coverage of the equivalent multiport circuit antenna representations, EM coupling between multiport antenna systems and their EM interactions with scatterers, accompanied with the corresponding EM compensation theorems.

  9. Topological Foundations of Electromagnetism

    CERN Document Server

    Barrett, Terrence W

    2008-01-01

    Topological Foundations of Electromagnetism seeks a fundamental understanding of the dynamics of electromagnetism; and marshals the evidence that in certain precisely defined topological conditions, electromagnetic theory (Maxwell's theory) must be extended or generalized in order to provide an explanation and understanding of, until now, unusual electromagnetic phenomena. Key to this generalization is an understanding of the circumstances under which the so-called A potential fields have physical effects. Basic to the approach taken is that the topological composition of electromagnetic field

  10. Cam deformity and the omega angle, a novel quantitative measurement of femoral head-neck morphology: a 3D CT gender analysis in asymptomatic subjects

    Energy Technology Data Exchange (ETDEWEB)

    Mascarenhas, Vasco V.; Gaspar, Augusto [Hospital da Luz, MSK imaging Unit (UIME), Imaging Center, Lisbon (Portugal); Rego, Paulo [Hospital da Luz, Department of Orthopaedic Surgery, Lisbon (Portugal); Dantas, Pedro [Hospital CUF Descobertas, Lisbon (Portugal); Soldado, Francisco [Universitat de Barcelona, Hospital Sant Joan de Deu, Barcelona (Spain); Consciencia, Jose G. [NOVA Medical School, Lisbon (Portugal)

    2017-05-15

    Our objectives were to use 3D computed tomography (CT) to define head-neck morphologic gender-specific and normative parameters in asymptomatic individuals and use the omega angle (Ω ) to provide quantification data on the location and radial extension of a cam deformity. We prospectively included 350 individuals and evaluated 188 asymptomatic hips that underwent semiautomated CT analysis. Different thresholds of alpha angle (α ) were considered in order to analyze cam morphology and determine Ω . We calculated overall and gender-specific parameters for imaging signs of cam morphology (Ω and circumferential α ). The 95 % reference interval limits were beyond abnormal thresholds found in the literature for cam morphology. Specifically, α at 3/1 oclock were 46.9 /60.8 overall, 51.8 /65.4 for men and 45.7 /55.3 for women. Cam prevalence, magnitude, location, and epicenter were significantly gender different. Increasing α correlated with higher Ω , meaning that higher angles correspond to larger cam deformities. Hip morphometry measurements in this cohort of asymptomatic individuals extended beyond current thresholds used for the clinical diagnosis of cam deformity, and α was found to vary both by gender and measurement location. These results suggest that α measurement is insufficient for the diagnosis of cam deformity. Enhanced morphometric evaluation, including 3D imaging and Ω , may enable a more accurate diagnosis. (orig.)

  11. Enthesitis in patients with psoriatic arthritis, axial spondyloarthritis and healthy subjects assessed by ‘head-to-toe’ whole-body MRI and clinical examination

    DEFF Research Database (Denmark)

    Poggenborg, René Panduro; Eshed, Iris; Østergaard, Mikkel

    2015-01-01

    OBJECTIVES: To investigate the ability of whole-body MRI (WBMRI) to detect axial and peripheral enthesitis in patients with psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA), and in healthy subjects (HS). Furthermore, to develop MRI enthesitis indices based on WBMRI and validate...... and patient global (ρ=0.29-0.31, pimaging modality for evaluation of enthesitis in patients with PsA and axSpA, but requires further investigation before clinical use....

  12. Characterizing the Vertical Distribution of Hydraulic Conductivity Using the Multilevel Slug Test Subject to Skin Effects: Comparison of the Uniform-head and Uniform-flux Wellbore Conditions

    Science.gov (United States)

    wei-Chiang, C.; Chen, C. S.

    2016-12-01

    The multilevel slug test (MLST) is an in-well technique in characterizing the vertical distribution of hydraulic conductivity K(z) in granular or fractured formations. In modeling MLST, the well screen is either simulated as a uniform-flux (UF) or a uniform head (UH) condition. This study investigates the impact of the skin effect, positive or negative, on the UH and UF models. The positive skin effect, as associated with a reduced hydraulic conductivity surrounding the well due to drilling mud invasion, is taken into account by making use of a skin factor, Sk.The negative skin effect, as associated with an increased hydraulic conductivity due to overdeveloping of the well, is modeled by using an effective well radius, re, which is greater than or equal to the well radius, rw. The UF and UH models are compared using different values of Sk and re for a variety of the partial penetration ratio of screen length to aquifer thickness, φ, the vertical anisotropy ratio of hydraulic conductivity, κ, and the aspect ratio of rw to the screen length, α. It is found that (1) the two models yield results of negligible difference when the well fully penetrates the aquifer (i.e., φ=1) regardless of the values of α,κ, Sk or re, (2) the two models yield essentially the same results for negative skin for all α and κ, (3) the difference between the two models decreases as Sk gets larger, regardless of the values of α, φ, or κ, yet it becomes negligible for Sk is greater than unity, and (4) when the skin effect is absent, the maximum difference between the two models is within 3-5%. As a result, it is suggested the UF model be used since it is mathematically easier to solve than the UH model, with or without skin effects.

  13. Head Injuries

    Science.gov (United States)

    ... ATV) Safety Balance Disorders Knowing Your Child's Medical History First Aid: Falls First Aid: Head Injuries Preventing Children's Sports Injuries Getting Help: Know the Numbers Concussions Stay ...

  14. COHERENCE PROPERTIES OF ELECTROMAGNETIC RADIATION,

    Science.gov (United States)

    ELECTROMAGNETIC RADIATION , COHERENT SCATTERING), (*COHERENT SCATTERING, ELECTROMAGNETIC RADIATION ), LIGHT, INTERFERENCE, INTENSITY, STATISTICAL FUNCTIONS, QUANTUM THEORY, BOSONS, INTERFEROMETERS, CHINA

  15. Case Study Regarding the Design of a Direct Current Electromagnet for the MIG Welding of Metallic Materials Part II: Constructive-Electromagnetic Dimension and Verification of the Electromagnet Operation

    Directory of Open Access Journals (Sweden)

    Tudorel Ene

    2016-10-01

    Full Text Available The paper refers to the design of a direct current electromagnet, located on the head of a swan neck welding gun of a MIG welding equipment and used for magnetising the rotation space of two additional electric arches, in order to preheat the electrode wire and of the protective gas, partially turned into plasma jet. We present the constructive - electromagnetic dimensioning and the verification of the electromagnet operation.

  16. Electromagnetic Education in India

    Science.gov (United States)

    Bajpai, Shrish; Asif, Siddiqui Sajida; Akhtar, Syed Adnan

    2016-01-01

    Out of the four fundamental interactions in nature, electromagnetics is one of them along with gravitation, strong interaction and weak interaction. The field of electromagnetics has made much of the modern age possible. Electromagnets are common in day-to-day appliances and are becoming more conventional as the need for technology increases.…

  17. Head Lice

    Science.gov (United States)

    ... 1044-1047. Canyon, DV, Speare R, et al . “Spatial and kinetic factors for the transfer of head ... for children. Natural products can give parents false sense of safety If using a natural product or ...

  18. Head First Statistics

    CERN Document Server

    Griffiths, Dawn

    2009-01-01

    Wouldn't it be great if there were a statistics book that made histograms, probability distributions, and chi square analysis more enjoyable than going to the dentist? Head First Statistics brings this typically dry subject to life, teaching you everything you want and need to know about statistics through engaging, interactive, and thought-provoking material, full of puzzles, stories, quizzes, visual aids, and real-world examples. Whether you're a student, a professional, or just curious about statistical analysis, Head First's brain-friendly formula helps you get a firm grasp of statistics

  19. Hydrological Aspects of Electromagnetic Surveys

    Directory of Open Access Journals (Sweden)

    Baden G. Williams

    2014-01-01

    Full Text Available Interpreting Electromagnetic (EM surveys - Electromagnetic induction techniques have now largely replaced previous descriptive, and largely subjective, techniques used for soil salinity surveys. The question then is a matter of how to interpret the EM data. A very clear linkage exists between Apparent Electrical Conductivity (ECa and the total soluble salts in the upper soil profile. This, in turn, can be interpreted as reflecting the degree of vertical/ lateral leaching of soluble salts, or of salt accumulation in the profile. Topography, depth to groundwater and groundwater salinity also appear to affect ECa, although they are not suited to rapid survey techniques and do not necessarily have a direct relationship with either the total salt content of the upper soil profile or the ECa values. The interpretation of isoconductivity maps in terms of the degree of leaching of the soil profile from point to point provides an added hydrological management perspective to EM soil salinity surveys.

  20. Basic Electromagnetism and Materials

    CERN Document Server

    Moliton, André

    2007-01-01

    Basic Electromagnetism and Materials is the product of many years of teaching basic and applied electromagnetism. This textbook can be used to teach electromagnetism to a wide range of undergraduate science majors in physics, electrical engineering or materials science. However, by making lesser demands on mathematical knowledge than competing texts, and by emphasizing electromagnetic properties of materials and their applications, this textbook is uniquely suited to students of materials science. Many competing texts focus on the study of propagation waves either in the microwave or optical domain, whereas Basic Electromagnetism and Materials covers the entire electromagnetic domain and the physical response of materials to these waves. Professor André Moliton is Director of the Unité de Microélectronique, Optoélectronique et Polymères (Université de Limoges, France), which brings together three groups studying the optoelectronics of molecular and polymer layers, micro-optoelectronic systems for teleco...

  1. Electromagnetic ultrasonic guided waves

    CERN Document Server

    Huang, Songling; Li, Weibin; Wang, Qing

    2016-01-01

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

  2. Static electromagnetic frequency changers

    CERN Document Server

    Rozhanskii, L L

    1963-01-01

    Static Electromagnetic Frequency Changers is about the theory, design, construction, and applications of static electromagnetic frequency changers, devices that used for multiplication or division of alternating current frequency. It is originally published in the Russian language. This book is organized into five chapters. The first three chapters introduce the readers to the principles of operation, the construction, and the potential applications of static electromagnetic frequency changers and to the principles of their design. The two concluding chapters use some hitherto unpublished work

  3. Review on Computational Electromagnetics

    Directory of Open Access Journals (Sweden)

    P. Sumithra

    2017-03-01

    Full Text Available Computational electromagnetics (CEM is applied to model the interaction of electromagnetic fields with the objects like antenna, waveguides, aircraft and their environment using Maxwell equations.  In this paper the strength and weakness of various computational electromagnetic techniques are discussed. Performance of various techniques in terms accuracy, memory and computational time for application specific tasks such as modeling RCS (Radar cross section, space applications, thin wires, antenna arrays are presented in this paper.

  4. Electromagnetic Radiation Analysis

    Science.gov (United States)

    1978-04-10

    A methodology is given for determining whether electromagnetic radiation of sufficient strength to cause performance degradation to the test item...exists at the test item location. The results of an electromagnetic radiation effects test are used to identify the radio frequencies and electromagnetic ... radiation levels to which the test item is susceptible. Further, using a test bed, comparisons are made with the representative signal levels to

  5. Electromagnetic Interface Testing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Electromagnetic Interface Testing facilitysupports such testing asEmissions, Field Strength, Mode Stirring, EMP Pulser, 4 Probe Monitoring/Leveling System, and...

  6. Understanding geometric algebra for electromagnetic theory

    CERN Document Server

    Arthur, John W

    2011-01-01

    "This book aims to disseminate geometric algebra as a straightforward mathematical tool set for working with and understanding classical electromagnetic theory. It's target readership is anyone who has some knowledge of electromagnetic theory, predominantly ordinary scientists and engineers who use it in the course of their work, or postgraduate students and senior undergraduates who are seeking to broaden their knowledge and increase their understanding of the subject. It is assumed that the reader is not a mathematical specialist and is neither familiar with geometric algebra or its application to electromagnetic theory. The modern approach, geometric algebra, is the mathematical tool set we should all have started out with and once the reader has a grasp of the subject, he or she cannot fail to realize that traditional vector analysis is really awkward and even misleading by comparison"--Provided by publisher.

  7. High frequency electromagnetic dosimetry

    CERN Document Server

    Sánchez-Hernández, David A

    2009-01-01

    Along with the growth of RF and microwave technology applications, there is a mounting concern about the possible adverse effects over human health from electromagnetic radiation. Addressing this issue and putting it into perspective, this groundbreaking resource provides critical details on the latest advances in high frequency electromagnetic dosimetry.

  8. Electromagnetic compatibility overview

    Science.gov (United States)

    Davis, K. C.

    1980-01-01

    An assessment of the electromagnetic compatibility impact of the Satellite Power System is discussed. The discussion is divided into two parts: determination of the emission expected from SPS including their spatial and spectral distributions, and evaluation of the impact of such emissions on electromagnetic systems including considerations of means for mitigating effects.

  9. Electromagnetically Operated Counter

    Science.gov (United States)

    Goldberg, H D; Goldberg, M I

    1951-12-18

    An electromagnetically operated counter wherein signals to be counted are applied to cause stepwise rotation of a rotatable element which is connected to a suitable register. The mechanism involved consists of a rotatable armature having three spaced cores of magnetic material and a pair of diametrically opposed electromagnets with a suitable pulsing circuit to actuate the magnets.

  10. Tunability enhanced electromagnetic wiggler

    Science.gov (United States)

    Schlueter, R.D.; Deis, G.A.

    1992-03-24

    The invention discloses a wiggler used in synchrotron radiation sources and free electron lasers, where each pole is surrounded by at least two electromagnetic coils. The electromagnetic coils are energized with different amounts of current to provide a wide tunable range of the on-axis magnetic flux density, while preventing magnetic saturation of the poles. 14 figs.

  11. Classical electromagnetic radiation

    CERN Document Server

    Heald, Mark A

    2012-01-01

    Newly corrected, this highly acclaimed text is suitable for advanced physics courses. The author presents a very accessible macroscopic view of classical electromagnetics that emphasizes integrating electromagnetic theory with physical optics. The survey follows the historical development of physics, culminating in the use of four-vector relativity to fully integrate electricity with magnetism.

  12. An Electromagnetic Beam Converter

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to an electromagnetic beam converter and a method for conversion of an input beam of electromagnetic radiation having a bell shaped intensity profile a(x,y) into an output beam having a prescribed target intensity profile l(x',y') based on a further development...

  13. Biological effects of electromagnetic fields | Yalçın | African Journal ...

    African Journals Online (AJOL)

    Recently, the possible effects of extra low frequency electromagnetic fields on the public health have become an interesting subject. Generally, electromagnetic fields occur around the high voltage lines. However, electromagnetic fields also occur with some electrical machines use for fun and TV used routinely at our home ...

  14. Physics of classical electromagnetism

    CERN Document Server

    Fujimoto, Minoru

    2007-01-01

    The classical electromagnetism described by the Maxwell equations constitutes a fundamental law in contemporary physics. Even with the advent of sophisticated new materials, the principles of classical electromagnetism are still active in various applied areas in today’s advanced communication techniques. Physics of Classical Electromagnetism, by Minoru Fujimoto, is written with concise introductory arguments emphasizing the original field concept, with an aim at understanding objectives in modern information technology. Following basic discussions of electromagnetism with a modernized approach, this book will provide readers with an overview of current problems in high-frequency physics. To further the reader’s understanding of the concepts and applications discussed, each illustration within the book shows the location of all active charges, and the author has provided many worked-out examples throughout the book. Physics of Classical Electromagnetism is intended for students in physics and engineering ...

  15. A comparative study of the origin, structure, and indexing language of the Persian and English keywords of articles indexed in the IranMedex database and their compliance with the Persian medical thesaurus and Medical Subject Headings.

    Science.gov (United States)

    Parsaei-Mohammadi, Parastoo; Ghasemi, Ali Hossein; Hassanzadeh-Beheshtabad, Raziyeh

    2017-01-01

    In the present era, thesauri as tools in indexing play an effective role in integrating retrieval preventing fragmentation as well as a multiplicity of terminologies and also in providing information content of documents. This study aimed to investigate the keywords of articles indexed in IranMedex in terms of origin, structure and indexing situation and their Compliance with the Persian Medical Thesaurus and Medical Subject Headings (MeSH). This study is an applied research, and a survey has been conducted. Statistical population includes 32,850 Persian articles which are indexed in the IranMedex during the years 1385-1391. 379 cases were selected as sample of the study. Data collection was done using a checklist. In analyzing the findings, the SPSS Software were used. Although there was no significant difference in terms of indexing origin between the proportion of different types of the Persian and English keywords of articles indexed in the IranMedex, the compliance rates of the Persian and English keywords with the Persian medical thesaurus and MeSH were different in different years. In the meantime, the structure of keywords is leaning more towards phrase structure, and a single word structure and the majority of keywords are selected from the titles and abstracts. The authors' familiarity with the thesauri and controlled tools causes homogeneity in assigning keywords and also provides more precise, faster, and easier retrieval of the keywords. It's suggested that a mixture of natural and control languages to be used in this database in order to reach more comprehensive results.

  16. Complex analysis of electromagnetic machines for vibro-impact technologies

    Science.gov (United States)

    Neyman, L. A.; Neyman, V. Yu

    2017-10-01

    For the implementation of high-energy impulse technologies of mechanical shock methods of secondary rock destruction, electromagnetic machines of vibro-impact action are of particular interest. Linear synchronous electromagnetic impact machine designs as a part of progress trend are considered where the head reciprocal motion is synchronized with 50 Hz power source pulses frequency applied to a winding or a system of windings. On the basis of identified differences of the head forced mechanical oscillation processes, merits and demerits of the work cycles of single or two-winding synchronous machine design variants are analyzed. Synchronous electromagnetic machines of a new design and principles of their control in a work cycle are presented. The specific half-wave interleaving of voltages applied to the windings allows reducing current amplitude and the influence of the impact drive on the power grid. To improve forced oscillation mode stability and precision, the new engineering solutions improving machines performances and exploitation conditions are proposed.

  17. Nonlinear surface electromagnetic phenomena

    CERN Document Server

    Ponath, H-E

    1991-01-01

    In recent years the physics of electromagnetic surface phenomena has developed rapidly, evolving into technologies for communications and industry, such as fiber and integrated optics. The variety of phenomena based on electromagnetism at surfaces is rich and this book was written with the aim of summarizing the available knowledge in selected areas of the field. The book contains reviews written by solid state and optical physicists on the nonlinear interaction of electromagnetic waves at and with surfaces and films. Both the physical phenomena and some potential applications are

  18. Computer techniques for electromagnetics

    CERN Document Server

    Mittra, R

    1973-01-01

    Computer Techniques for Electromagnetics discusses the ways in which computer techniques solve practical problems in electromagnetics. It discusses the impact of the emergence of high-speed computers in the study of electromagnetics. This text provides a brief background on the approaches used by mathematical analysts in solving integral equations. It also demonstrates how to use computer techniques in computing current distribution, radar scattering, and waveguide discontinuities, and inverse scattering. This book will be useful for students looking for a comprehensive text on computer techni

  19. Is HEADS in our heads?

    DEFF Research Database (Denmark)

    Boisen, Kirsten A; Hertz, Pernille Grarup; Blix, Charlotte

    2016-01-01

    BACKGROUND: Outpatient clinic visits are a window of opportunity to address health risk behaviors and promote a healthier lifestyle among young people. The HEADS (Home, Education, Eating, Activities, Drugs [i.e. substance use including tobacco, alcohol, and illegal drugs], Sexuality [including...... contraception], Safety, Self-harm) interview is a feasible way of exploring health risk behaviors and resilience. OBJECTIVE: The purpose of this study was to evaluate how often HEADS topics were addressed according to young patients and staff in pediatric and adult outpatient clinics. METHODS: We conducted...... care professionals participated. We found only small reported differences between staff and young patients regarding whether home, education, and activity were addressed. However, staff reported twice the rate of addressing smoking, alcohol, illegal drugs, sexuality, and contraception compared to young...

  20. BGO* electromagnetic calorimeter

    CERN Multimedia

    CERN

    1988-01-01

    * Short for Bismuth-Germanium-Oxyde, a scintillator of high atomic number Z used in electromagnetic crystal calorimeters. BGO is characterized by fast rise time (a few nanoseconds) and short radiation length (1.11 cm).

  1. Broadband Electromagnetic Technology

    Science.gov (United States)

    2011-06-23

    The objectives of this project are to continue the enhancements to the combined Broadband Electromagnetic and Full Encirclement Unit (BEM-FEU) technologies and to evaluate the systems capability in the laboratory and the field. The BEM instrument ...

  2. Computational electromagnetic-aerodynamics

    CERN Document Server

    Shang, Joseph J S

    2016-01-01

    Presents numerical algorithms, procedures, and techniques required to solve engineering problems relating to the interactions between electromagnetic fields, fluid flow, and interdisciplinary technology for aerodynamics, electromagnetics, chemical-physics kinetics, and plasmadynamics This book addresses modeling and simulation science and technology for studying ionized gas phenomena in engineering applications. Computational Electromagnetic-Aerodynamics is organized into ten chapters. Chapter one to three introduce the fundamental concepts of plasmadynamics, chemical-physics of ionization, classical magnetohydrodynamics, and their extensions to plasma-based flow control actuators, high-speed flows of interplanetary re-entry, and ion thrusters in space exploration. Chapter four to six explain numerical algorithms and procedures for solving Maxwell’s equation in the time domain for computational electromagnetics, plasma wave propagation, and the time-dependent c mpressible Navier-Stokes equation for aerodyn...

  3. The classical electromagnetic field

    CERN Document Server

    Eyges, Leonard

    2010-01-01

    This excellent text covers a year's course in advanced theoretical electromagnetism, first introducing theory, then its application. Topics include vectors D and H inside matter, conservation laws for energy, momentum, invariance, form invariance, covariance in special relativity, and more.

  4. Purely electromagnetic spacetimes

    OpenAIRE

    Ivanov, B. V.

    2007-01-01

    Electrovacuum solutions devoid of usual mass sources are classified in the case of one, two and three commuting Killing vectors. Three branches of solutions exist. Electromagnetically induced mass terms appear in some of them.

  5. Electromagnetic reverberation chambers

    CERN Document Server

    Besnier, Philippe

    2013-01-01

    Dedicated to a complete presentation on all aspects of reverberation chambers, this book provides the physical principles behind these test systems in a very progressive manner. The detailed panorama of parameters governing the operation of electromagnetic reverberation chambers details various applications such as radiated immunity, emissivity, and shielding efficiency experiments.In addition, the reader is provided with the elements of electromagnetic theory and statistics required to take full advantage of the basic operational rules of reverberation chambers, including calibration proc

  6. Electromagnetic Education in India

    Directory of Open Access Journals (Sweden)

    Bajpai Shrish

    2016-06-01

    Full Text Available Out of the four fundamental interactions in nature, electromagnetics is one of them along with gravitation, strong interaction and weak interaction. The field of electromagnetics has made much of the modern age possible. Electromagnets are common in day-to-day appliances and are becoming more conventional as the need for technology increases. Electromagnetism has played a vital role in the progress of human kind ever since it has been understood. Electromagnets are found everywhere. One can find them in speakers, doorbells, home security systems, anti-shoplifting systems, hard drives, mobiles, microphones, Maglev trains, motors and many other everyday appliances and products. Before diving into the education system, it is necessary to reiterate its importance in various technologies that have evolved over time. Almost every domain of social life has electromagnetic playing its role. Be it the mobile vibrators you depend upon, a water pump, windshield wipers during rain and the power windows of your car or even the RFID tags that may ease your job during shopping. A flavor of electromagnetics is essential during primary level of schooling for the student to understand its future prospects and open his/her mind to a broad ocean of ideas. Due to such advancements this field can offer, study on such a field is highly beneficial for a developing country like India. The paper presents the scenario of electromagnetic education in India, its importance and numerous schemes taken by the government of India to uplift and acquaint the people about the importance of EM and its applications.

  7. Electromagnetic rotational actuation.

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, Alexander Lee

    2010-08-01

    There are many applications that need a meso-scale rotational actuator. These applications have been left by the wayside because of the lack of actuation at this scale. Sandia National Laboratories has many unique fabrication technologies that could be used to create an electromagnetic actuator at this scale. There are also many designs to be explored. In this internship exploration of the designs and fabrications technologies to find an inexpensive design that can be used for prototyping the electromagnetic rotational actuator.

  8. Grid computing for electromagnetics

    CERN Document Server

    Tarricone, Luciano

    2004-01-01

    Today, more and more practitioners, researchers, and students are utilizing the power and efficiency of grid computing for their increasingly complex electromagnetics applications. This cutting-edge book offers you the practical and comprehensive guidance you need to use this new approach to supercomputing for your challenging projects. Supported with over 110 illustrations, the book clearly describes a high-performance, low-cost method to solving huge numerical electromagnetics problems.

  9. A Study Of EMR And SAR Distribution In Human Head Phantom ...

    African Journals Online (AJOL)

    power of 0.32W for both simulations were well below the limit of 1.6 W/kg of ICNIRP standard and FCC/IEEE standard of 2W/kg. Keywords: Electromagnetic radiation (EMR), Specific Absorption Rate (SAR), Electromagnetic simulation software (FEKO emss), Radio frequency field, human head, mobile phone, mobile phone ...

  10. Model of electrical activity in cardiac tissue under electromagnetic induction.

    Science.gov (United States)

    Wu, Fuqiang; Wang, Chunni; Xu, Ying; Ma, Jun

    2016-12-23

    Complex electrical activities in cardiac tissue can set up time-varying electromagnetic field. Magnetic flux is introduced into the Fitzhugh-Nagumo model to describe the effect of electromagnetic induction, and then memristor is used to realize the feedback of magnetic flux on the membrane potential in cardiac tissue. It is found that a spiral wave can be triggered and developed by setting specific initials in the media, that is to say, the media still support the survival of standing spiral waves under electromagnetic induction. Furthermore, electromagnetic radiation is considered on this model as external stimuli, it is found that spiral waves encounter breakup and turbulent electrical activities are observed, and it can give guidance to understand the occurrence of sudden heart disorder subjected to heavily electromagnetic radiation.

  11. Electromagnetic fields and their impacts

    Science.gov (United States)

    Prša, M. A.; Kasaš-Lažetić, K. K.

    2018-01-01

    The main goal of this paper is to briefly recall some different electromagnetic field definitions, some macroscopic sources of electromagnetic fields, electromagnetic fields classification regarding time dependences, and the ways of field determination in concrete cases. After that, all the mechanisms of interaction between electromagnetic field and substance, on atomic level, are described in details. Interaction between substance and electric field is investigated separately from the substance and magnetic field interaction. It is demonstrated that, in all cases of the unique electromagnetic field, total interaction can be treated as a superposition of two separated interactions. Finally, the main electromagnetic fields surrounding us is cited and discussed.

  12. Transition analysis of magnetic recording heads using FDTD

    Energy Technology Data Exchange (ETDEWEB)

    Tanabe, Shinji E-mail: tanabe@ele.crl.melco.co.jp

    2001-10-01

    Transition waveforms of a magnetic recording head have been analyzed using finite difference time domain (FDTD). The distributed inductance and capacitance of the head effect the rising time of the magnetic fields in the recording process. FDTD electromagnetic analysis is easy to combine with SPICE circuit analysis. Using this combined program, a transition analysis of the recording process including a write amplifier has become possible.

  13. Aircraft electromagnetic compatibility

    Science.gov (United States)

    Clarke, Clifton A.; Larsen, William E.

    1987-06-01

    Illustrated are aircraft architecture, electromagnetic interference environments, electromagnetic compatibility protection techniques, program specifications, tasks, and verification and validation procedures. The environment of 400 Hz power, electrical transients, and radio frequency fields are portrayed and related to thresholds of avionics electronics. Five layers of protection for avionics are defined. Recognition is given to some present day electromagnetic compatibility weaknesses and issues which serve to reemphasize the importance of EMC verification of equipment and parts, and their ultimate EMC validation on the aircraft. Proven standards of grounding, bonding, shielding, wiring, and packaging are laid out to help provide a foundation for a comprehensive approach to successful future aircraft design and an understanding of cost effective EMC in an aircraft setting.

  14. Metamaterial electromagnetic wave absorbers.

    Science.gov (United States)

    Watts, Claire M; Liu, Xianliang; Padilla, Willie J

    2012-06-19

    The advent of negative index materials has spawned extensive research into metamaterials over the past decade. Metamaterials are attractive not only for their exotic electromagnetic properties, but also their promise for applications. A particular branch-the metamaterial perfect absorber (MPA)-has garnered interest due to the fact that it can achieve unity absorptivity of electromagnetic waves. Since its first experimental demonstration in 2008, the MPA has progressed significantly with designs shown across the electromagnetic spectrum, from microwave to optical. In this Progress Report we give an overview of the field and discuss a selection of examples and related applications. The ability of the MPA to exhibit extreme performance flexibility will be discussed and the theory underlying their operation and limitations will be established. Insight is given into what we can expect from this rapidly expanding field and future challenges will be addressed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Aircraft electromagnetic compatibility

    Science.gov (United States)

    Clarke, Clifton A.; Larsen, William E.

    1987-01-01

    Illustrated are aircraft architecture, electromagnetic interference environments, electromagnetic compatibility protection techniques, program specifications, tasks, and verification and validation procedures. The environment of 400 Hz power, electrical transients, and radio frequency fields are portrayed and related to thresholds of avionics electronics. Five layers of protection for avionics are defined. Recognition is given to some present day electromagnetic compatibility weaknesses and issues which serve to reemphasize the importance of EMC verification of equipment and parts, and their ultimate EMC validation on the aircraft. Proven standards of grounding, bonding, shielding, wiring, and packaging are laid out to help provide a foundation for a comprehensive approach to successful future aircraft design and an understanding of cost effective EMC in an aircraft setting.

  16. Applied electromagnetic scattering theory

    CERN Document Server

    Osipov, Andrey A

    2017-01-01

    Besides classical applications (radar and stealth, antennas, microwave engineering), scattering and diffraction are enabling phenomena for some emerging research fields (artificial electromagnetic materials or metamaterials, terahertz technologies, electromagnetic aspects of nano-science). This book is a tutorial for advanced students who need to study diffraction theory. The textbook gives fundamental knowledge about scattering and diffraction of electromagnetic waves and provides some working examples of solutions for practical high-frequency scattering and diffraction problems. The book focuses on the most important diffraction effects and mechanisms influencing the scattering process and describes efficient and physically justified simulation methods - physical optics (PO) and the physical theory of diffraction (PTD) - applicable in typical remote sensing scenarios. The material is presented in a comprehensible and logical form, which relates the presented results to the basic principles of electromag...

  17. Electromagnetic fields and interactions

    CERN Document Server

    Becker, Richard L

    1964-01-01

    For more than a century, ""Becker"" and its forerunner, ""Abraham-Becker,"" have served as the bible of electromagnetic theory for countless students. This definitive translation of the physics classic features both volumes of the original text.Volume I, on electromagnetic theory, includes an introduction to vector and tensor calculus, the electrostatic field, electric current and the field, and the theory of relativity. The second volume comprises a self-contained introduction to quantum theory that covers the classical principles of electron theory and quantum mechanics, problems involving

  18. Electromagnetic clutches and couplings

    CERN Document Server

    Vorob'Yeva, T M; Fry, D W; Higinbotham, W

    2013-01-01

    Electromagnetic Clutches and Couplings contains a detailed description of U.S.S.R. electromagnetic friction clutches, magnetic couplings, and magnetic particle couplings. This book is divided into four chapters. The first chapter discusses the design and construction of magnetic (solenoid-operated) couplings, which are very quick-acting devices and used in low power high-speed servo-systems. Chapter 2 describes the possible fields of application, design, construction, and utilization of magnetic particle couplings. The aspects of construction, design, and utilization of induction clutches (sli

  19. The theory of electromagnetism

    CERN Document Server

    Jones, D S

    1964-01-01

    The Theory of the Electomagnetism covers the behavior of electromagnetic fields and those parts of applied mathematics necessary to discover this behavior. This book is composed of 11 chapters that emphasize the Maxwell's equations. The first chapter is concerned with the general properties of solutions of Maxwell's equations in matter, which has certain macroscopic properties. The succeeding chapters consider specific problems in electromagnetism, including the determination of the field produced by a variable charge, first in isolation and then in the surface distributions of an antenna. The

  20. Improved Electromagnetic Brake

    Science.gov (United States)

    Martin, Toby B.

    2004-01-01

    A proposed design for an electromagnetic brake would increase the reliability while reducing the number of parts and the weight, relative to a prior commercially available electromagnetic brake. The reductions of weight and the number of parts could also lead to a reduction of cost. A description of the commercial brake is prerequisite to a description of the proposed electromagnetic brake. The commercial brake (see upper part of figure) includes (1) a permanent magnet and an electromagnet coil on a stator and (2) a rotor that includes a steel contact plate mounted, with tension spring loading, on an aluminum hub. The stator is mounted securely on a stationary object, which would ordinarily be the housing of a gear drive or a motor. The rotor is mounted on the shaft of the gear drive or motor. The commercial brake nominally operates in a fail-safe (in the sense of normally braking) mode: In the absence of current in the electromagnet coil, the permanent magnet pulls the contact plate, against the spring tension, into contact with the stator. To release the brake, one excites the electromagnet with a current of the magnitude and polarity chosen to cancel the magnetic flux of the permanent magnet, thereby enabling the spring tension to pull the contact plate out of contact with the stator. The fail-safe operation of the commercial brake depends on careful mounting of the rotor in relation to the stator. The rotor/stator gap must be set with a tolerance between 10 and 15 mils (between about 0.25 and about 0.38 mm). If the gap or the contact pad is thicker than the maximum allowable value, then the permanent magnetic field will not be strong enough to pull the steel plate across the gap. (For this reason, any contact pad between the contact plate and the stator must also be correspondingly thin.) If the gap exceeds the maximum allowable value because of shaft end play, it becomes impossible to set the brake by turning off the electromagnet current. Although it may

  1. Lectures on electromagnetism

    CERN Document Server

    Das, Ashok

    2013-01-01

    These lecture notes on electromagnetism have evolved from graduate and undergraduate EM theory courses given by the author at the University of Rochester, with the basics presented with clarity and his characteristic attention to detail. The thirteen chapters cover, in logical sequence, topics ranging from electrostatics, magnetostatics and Maxwell's equations to plasmas and radiation. Boundary value problems are treated extensively, as are wave guides, electromagnetic interactions and fields. This second edition comprises many of the topics expanded with more details on the derivation of vari

  2. Volcano-electromagnetic effects

    Science.gov (United States)

    Johnston, Malcolm J. S.

    2007-01-01

    Volcano-electromagnetic effects—electromagnetic (EM) signals generated by volcanic activity—derive from a variety of physical processes. These include piezomagnetic effects, electrokinetic effects, fluid vaporization, thermal demagnetization/remagnetization, resistivity changes, thermochemical effects, magnetohydrodynamic effects, and blast-excited traveling ionospheric disturbances (TIDs). Identification of different physical processes and their interdependence is often possible with multiparameter monitoring, now common on volcanoes, since many of these processes occur with different timescales and some are simultaneously identified in other geophysical data (deformation, seismic, gas, ionospheric disturbances, etc.). EM monitoring plays an important part in understanding these processes.

  3. Radio Frequency Electromagnetic Radiation From Streamer Collisions.

    Science.gov (United States)

    Luque, Alejandro

    2017-10-16

    We present a full electromagnetic model of streamer propagation where the Maxwell equations are solved self-consistently together with electron transport and reactions including photoionization. We apply this model to the collision of counter-propagating streamers in gaps tens of centimeters wide and with large potential differences of hundreds of kilovolts. Our results show that streamer collisions emit electromagnetic pulses that, at atmospheric pressure, dominate the radio frequency spectrum of an extended corona in the range from about 100 MHz to a few gigahertz. We also investigate the fast penetration, after a collision, of electromagnetic fields into the streamer heads and show that these fields are capable of accelerating electrons up to about 100 keV. By substantiating the link between X-rays and high-frequency radio emissions and by describing a mechanism for the early acceleration of runaway electrons, our results support the hypothesis that streamer collisions are essential precursors of high-energy processes in electric discharges.

  4. Radio Frequency Electromagnetic Radiation From Streamer Collisions

    Science.gov (United States)

    Luque, Alejandro

    2017-10-01

    We present a full electromagnetic model of streamer propagation where the Maxwell equations are solved self-consistently together with electron transport and reactions including photoionization. We apply this model to the collision of counter-propagating streamers in gaps tens of centimeters wide and with large potential differences of hundreds of kilovolts. Our results show that streamer collisions emit electromagnetic pulses that, at atmospheric pressure, dominate the radio frequency spectrum of an extended corona in the range from about 100 MHz to a few gigahertz. We also investigate the fast penetration, after a collision, of electromagnetic fields into the streamer heads and show that these fields are capable of accelerating electrons up to about 100 keV. By substantiating the link between X-rays and high-frequency radio emissions and by describing a mechanism for the early acceleration of runaway electrons, our results support the hypothesis that streamer collisions are essential precursors of high-energy processes in electric discharges.

  5. Electromagnetic fields in stratified media

    CERN Document Server

    Li, Kai

    2009-01-01

    Dealing with an important branch of electromagnetic theory with many useful applications in subsurface communication, radar, and geophysical prospecting and diagnostics, this book introduces electromagnetic theory and wave propagation in complex media.

  6. ABOUT THE URBAN ELECTROMAGNETIC POLLUTION

    National Research Council Canada - National Science Library

    Marius Lolea; Simona Dzitac

    2016-01-01

      This paper presents a brief statement of electromagnetic pollution generated by public sources of electromagnetic field, wich are distributed on the territory of City of Oradea, Bihor County, Romania...

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  8. Ideal and nonideal electromagnetic cloaks

    OpenAIRE

    Zharova, Nina A.; Shadrivov, Ilya V.; Zharov, Alexander A.; Kivshar, Yuri S.

    2008-01-01

    We employ the analytical results for the spatial transformation of the electromagnetic fields to obtain and analyze explicit expressions for the structure of the electromagnetic fields in invisibility cloaks, beam splitters, and field concentrators. We study the efficiency of nonideal electromagnetic cloaks and discuss the effect of scattering losses on the cloak invisibility.

  9. Electromagnetic radiation detector

    Science.gov (United States)

    Benson, Jay L.; Hansen, Gordon J.

    1976-01-01

    An electromagnetic radiation detector including a collimating window, a cathode member having a photoelectric emissive material surface angularly disposed to said window whereby radiation is impinged thereon at acute angles, an anode, separated from the cathode member by an evacuated space, for collecting photoelectrons emitted from the emissive cathode surface, and a negatively biased, high transmissive grid disposed between the cathode member and anode.

  10. Introduction to electromagnetic compatibility

    Science.gov (United States)

    Paul, Clayton R.

    A formal and extensive treatment of electromagnetic compatibility (EMC) is presented. Basic principles are reviewed in detail, including reasons for EMC in electronic design. Also discussed are: nonideal behavior of components, signal spectra, radiated emission and susceptibility, conducted emissions and susceptibility, crosstalk, shielding, electrostatic discharge, and system design for EMC.

  11. What Are Electromagnetic Fields?

    Science.gov (United States)

    ... them to quickly heat food. At radio frequencies, electric and magnetic fields are closely interrelated and we typically measure their levels as power densities in watts per square metre (W/m 2 ). Key points: The electromagnetic spectrum encompasses both natural and ...

  12. Electromagnetic distance measurement

    CERN Document Server

    1967-01-01

    This book brings together the work of forty-eight geodesists from twenty-five countries. They discuss various new electromagnetic distance measurement (EDM) instruments - among them the Tellurometer, Geodimeter, and air- and satellite-borne systems - and investigate the complex sources of error.

  13. Simple Superconducting "Permanent" Electromagnet

    Science.gov (United States)

    Israelson, Ulf E.; Strayer, Donald M.

    1992-01-01

    Proposed short tube of high-temperature-superconducting material like YBa2Cu3O7 acts as strong electromagnet that flows as long as magnetic field remains below critical value and temperature of cylinder maintained sufficiently below superconducting-transition temperature. Design exploits maximally anisotropy of high-temperature-superconducting material.

  14. Nanofocusing of electromagnetic radiation

    DEFF Research Database (Denmark)

    Gramotnev, D. K.; Bozhevolnyi, Sergey I.

    2014-01-01

    Nanofocusing of electromagnetic radiation, that is, reducing the cross sections of propagating optical modes far beyond the diffraction limit in dielectric media, can be achieved in tapered metal-dielectric waveguides that support surface plasmon-polariton modes. Although the main principles...

  15. "Hearing" Electromagnetic Waves

    Science.gov (United States)

    Rojo, Marta; Munoz, Juan

    2014-01-01

    In this work, an educational experience is described in which a microwave communication link is used to make students aware that all electromagnetic waves have the same physical nature and properties. Experimental demonstrations are linked to theoretical concepts to increase comprehension of the physical principles underlying electromagnetic…

  16. Electromagnetic structure of nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, R.G.

    1986-07-01

    A brief review is given of selected topics in the electromagnetic structure of nucleons and nuclei, including nucleon form factors from both quantum chromodynamics and electron scattering data, measurements of the deuteron and triton form factors, quasi-elastic scattering, and the EMC effect. 47 refs., 13 figs. (LEW)

  17. Faraday: Father of Electromagnetism

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 3. Faraday: Father of Electromagnetism. S V Bhat. General Article Volume 7 Issue 3 March 2002 pp 46-50. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/007/03/0046-0050. Keywords. Faraday ...

  18. Amplitudes of head movements during putative eye-only saccades.

    Science.gov (United States)

    Oommen, Brian S; Stahl, John S

    2005-12-14

    The mechanisms allowing humans and other primates to dissociate head and eye movements during saccades are poorly understood. A more precise knowledge of head movement behavior during apparent eye-only saccades may provide insight into those mechanisms. We studied the distributions of head amplitude in normal humans. In half of the subjects, these distributions indicated the presence of a population of minor ("residual") head movements during eye-only saccades, distinct from the continuum of head movements generated during frank eye-head saccades. Like full-sized head movements, the residual movements grew in proportion to target eccentricity, indicating their drive is derived from the premotor command for the saccade. Furthermore, their amplitudes related most strongly to the head amplitudes obtained when subjects produced full-sized head movements and were reduced when subjects were instructed to perform exclusively eye-only saccades. Both observations suggest that the drive for residual head movements originates downstream of the point in which the head movement command diverges from the generalized gaze shift command. The results are consistent with a model of head control in which a neural gate prevents the common gaze shift command from reaching the head premotor circuitry whenever an eye-only saccade is desired. However, the gate is either imperfect or the multiple pathways that relay gaze shift signals to the head motor circuitry allow for the gate to be circumvented. The results underscore the need for physiological studies to probe neuronal activity related to neck activation during eye-only saccades.

  19. Head Impact Laboratory (HIL)

    Data.gov (United States)

    Federal Laboratory Consortium — The HIL uses testing devices to evaluate vehicle interior energy attenuating (EA) technologies for mitigating head injuries resulting from head impacts during mine/...

  20. Study of the Interaction User Head-Ultrawideband MIMO Antenna Array for Mobile Terminals

    DEFF Research Database (Denmark)

    Zhekov, Stanislav Stefanov; Tatomirescu, Alexandru; Franek, Ondrej

    2016-01-01

    aspects of the interaction are considered: 1) the influence of the user head on the antenna operation, and 2) the exposure of the human head tissue to antenna electromagnetic radiation. The first aspect is related to the degradation of the antenna performance in a proximity to the user which is evaluated...

  1. New exposure system for human studies on possible effects of low dose radio frequency electromagnetic fields of GSM and UMTS on central nervous processes; Neuartiges Expositionssystem fuer Humanstudien zu moeglichen Wirkungen hochfrequenter elektromagnetischer Felder von GSM und UMTS auf zentralnervoese Verarbeitungsprozesse im Niedrigdosis-Bereich

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, G. [ARC Seibersdorf Research GmbH, Seibersdorf (Austria); Kundi, M. [Medizinische Univ. Wien (Austria). Inst. fuer Umwelthygiene; Molla-Djafari, H. [Allgemeine Unfallversicherungsanstalt AUVA, Wien (Austria)

    2004-07-01

    A new exposure system for human studies on possible effects of radio frequency (RF) electromagnetic fields on central nervous processes was developed. The system consists of a signal generation unit, a headset with antennas, which is worn by the test subject and a control and monitoring software allowing double blind application of RF exposure. The headset can be worn similar as spectacles and allows the mounting of one antenna at the left and one antenna at the right side of the head. This design provides a constant relative position between the antennas and the head and therefore a minimum of variation of the exposure, even in case of movements of the test subject. Furthermore test subjects' restriction is minimised and the head surface remains accessible for application of EEG-electrodes. In order to reduce the weight to be carried by the test subject's head the entire headset is suspended from the ceiling by a special suspension unit, yielding a resulting effective weight to be carried of less than 80 g. Using suitable antennas the system can be used for head exposures in the frequency range from 400 MHz to 5 GHz. (orig.)

  2. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray ... Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT or CAT ...

  3. Systematic analysis of head-to-head gene organization: evolutionary conservation and potential biological relevance.

    Directory of Open Access Journals (Sweden)

    Yuan-Yuan Li

    2006-07-01

    Full Text Available Several "head-to-head" (or "bidirectional" gene pairs have been studied in individual experiments, but genome-wide analysis of this gene organization, especially in terms of transcriptional correlation and functional association, is still insufficient. We conducted a systematic investigation of head-to-head gene organization focusing on structural features, evolutionary conservation, expression correlation and functional association. Of the present 1,262, 1,071, and 491 head-to-head pairs identified in human, mouse, and rat genomes, respectively, pairs with 1- to 400-base pair distance between transcription start sites form the majority (62.36%, 64.15%, and 55.19% for human, mouse, and rat,respectively of each dataset, and the largest group is always the one with a transcription start site distance of 101 to 200 base pairs. The phylogenetic analysis among Fugu, chicken, and human indicates a negative selection on the separation of head-to-head genes across vertebrate evolution, and thus the ancestral existence of this gene organization. The expression analysis shows that most of the human head-to-head genes are significantly correlated,and the correlation could be positive, negative, or alternative depending on the experimental conditions. Finally, head to-head genes statistically tend to perform similar functions, and gene pairs associated with the significant cofunctions seem to have stronger expression correlations. The findings indicate that the head-to-head gene organization is ancient and conserved, which subjects functionally related genes to correlated transcriptional regulation and thus provides an exquisite mechanism of transcriptional regulation based on gene organization. These results have significantly expanded the knowledge about head-to-head gene organization. Supplementary materials for this study are available at http://www.scbit.org/h2h.

  4. Electromagnetic wave energy converter

    Science.gov (United States)

    Bailey, R. L. (Inventor)

    1973-01-01

    Electromagnetic wave energy is converted into electric power with an array of mutually insulated electromagnetic wave absorber elements each responsive to an electric field component of the wave as it impinges thereon. Each element includes a portion tapered in the direction of wave propagation to provide a relatively wideband response spectrum. Each element includes an output for deriving a voltage replica of the electric field variations intercepted by it. Adjacent elements are positioned relative to each other so that an electric field subsists between adjacent elements in response to the impinging wave. The electric field results in a voltage difference between adjacent elements that is fed to a rectifier to derive dc output power.

  5. Electromagnetic Polarizabilities of Mesons

    Science.gov (United States)

    Aleksejevs, A.; Barkanova, S.

    2016-04-01

    The Chiral Perturbation Theory (CHPT) has been very successful in describing low-energy hadronic properties in the non-perturbative regime of Quantum Chromodynamics. The results of ChPT, many of which are currently under active experimental investigation, provide stringent predictions of many fundamental properties of hadrons, including quantities such as electromagnetic polarizabilities. Yet, even for the simplest hadronic system, a pion, we still have a broad spectrum of polarizability measurements (MARK II, VENUS, ALEPH, TPC/2g, CELLO, Belle, Crystal Ball). The meson polarizability can be accessed through Compton scattering, so we can measure it through Primakoff reaction. This paper will provide an analysis of the CHPT predictions of the SU(3) meson electromagnetic polarizabilities and outline their relationship to the Primakoff cross section at the kinematics relevant to the planned JLab experiments.

  6. The KLOE electromagnetic calorimeter

    CERN Document Server

    Adinolfi, M; Antonelli, A; Antonelli, M; Anulli, F; Barbiellini, G; Bencivenni, G; Bertolucci, Sergio; Bini, C; Bloise, C; Bocci, V; Bossi, F; Branchini, P; Cabibbo, G; Caloi, R; Campana, P; Casarsa, M; Cataldi, G; Ceradini, F; Cervelli, F; Ciambrone, P; De Lucia, E; De Simone, P; De Zorzi, G; Dell'Agnello, S; Denig, A; Di Domenico, A; Di Donato, C; Di Falco, S; Doria, A; Erriquez, O; Farilla, A; Ferrari, A; Ferrer, M L; Finocchiaro, G; Forti, C; Franceschi, A; Franzini, P; Gao, M L; Gatti, C; Gauzzi, P; Giannasi, A; Giovannella, S; Graziani, E; Han, H G; Han, S W; Huang, X; Incagli, M; Ingrosso, L; Keeble, L; Kim, W; Kuo, C; Lanfranchi, G; Lee-Franzini, J; Lomtadze, T A; Mao Chen Sheng; Martemyanov, M; Mei, W; Messi, R; Miscetti, S; Moccia, S; Moulson, M; Murtas, F; Müller, S; Pacciani, L; Palomba, M; Palutan, M; Pasqualucci, E; Passalacqua, L; Passeri, A; Picca, D; Pirozzi, G; Pontecorvo, L; Primavera, M; Santangelo, P; Santovetti, E; Saracino, G; Schamberger, R D; Sciascia, B; Scuri, F; Sfiligoi, I; Silano, P; Spadaro, T; Spiriti, E; Tortora, L; Valente, P; Valeriani, B; Venanzoni, G; Ventura, A; Wu, Y; Wölfle, S; Xie, Y G; Zema, P F; Zhang, C D; Zhang, J Q; Zhao, P P

    2002-01-01

    The KLOE detector was designed primarily for the study of CP violation in neutral kaon decays at DAPHINE, the Frascati phi-factory. The detector consists of a tracker and an electromagnetic calorimeter. A lead-scintillating-fiber sampling calorimeter satisfies best the requirements of the experiment, providing adequate energy resolution and superior timing accuracy. We describe in the following the construction of the calorimeter, its calibration and how the calorimeter information is used to obtain energy, point of entry and time of the arrival of photons, electrons and charged particles. With e sup + e sup - collision data at DAPHINE for an integrated luminosity of some 2 pb sup - sup 1 we find for electromagnetic showers, an energy resolution of 5.7%/sq root E(GeV) and a time resolution of 54/sq root E(GeV) ps. We also present a measurement of efficiency for low energy photons.

  7. Electromagnetic fields and waves

    CERN Document Server

    Iskander, Magdy F

    2013-01-01

    The latest edition of Electromagnetic Fields and Waves retains an authoritative, balanced approach, in-depth coverage, extensive analysis, and use of computational techniques to provide a complete understanding of electromagnetic—important to all electrical engineering students. An essential feature of this innovative text is the early introduction of Maxwell's equations, together with the quantifying experimental observations made by the pioneers who discovered electromagnetics. This approach directly links the mathematical relations in Maxwell's equations to real experiments and facilitates a fundamental understanding of wave propagation and use in modern practical applications, especially in today's wireless world. New and expanded topics include the conceptual relationship between Coulomb's law and Gauss's law for calculating electric fields, the relationship between Biot-Savart's and Ampere's laws and their use in calculating magnetic fields from current sources, the development of Faraday's law from e...

  8. Introduction to electromagnetic theory

    CERN Document Server

    Owen, George E

    2003-01-01

    A direct, stimulating approach to electromagnetic theory, this text employs matrices and matrix methods for the simple development of broad theorems. The author uses vector representation throughout the book, with numerous applications of Poisson's equation and the Laplace equation (the latter occurring in both electronics and magnetic media). Contents include the electrostatics of point charges, distributions of charge, conductors and dielectrics, currents and circuits, and the Lorentz force and the magnetic field. Additional topics comprise the magnetic field of steady currents, induced ele

  9. Electromagnetic Interaction Equations

    OpenAIRE

    Zinoviev, Yury M.

    2009-01-01

    For the electromagnetic interaction of two particles the relativistic quantum mechanics equations are proposed. These equations are solved for the case when one particle has a small mass and moves freely. The initial wave functions are supposed to be concentrated at the coordinates origin. The energy spectrum of another particle wave function is defined by the initial wave function of the free moving particle. Choosing the initial wave function of the free moving particle it is possible to ob...

  10. Gravitation and electromagnetism

    OpenAIRE

    Sidharth, B. G.

    2002-01-01

    Maxwell's equations comprise both electromagnetic and gravitational fields. The transverse part of the vector potential belongs to magnetism, the longitudinal one is concerned with gravitation. The Coulomb gauge indicates that longitudinal components of the fields propagate instantaneously. The delta-function singularity of the field of the divergence of the vector potential, referred to as the dilatation center, represents an elementary agent of gravitation. Viewing a particle as a source or...

  11. Forward modeling. Route to electromagnetic inversion

    Energy Technology Data Exchange (ETDEWEB)

    Groom, R.; Walker, P. [PetRos EiKon Incorporated, Ontario (Canada)

    1996-05-01

    Inversion of electromagnetic data is a topical subject in the literature, and much time has been devoted to understanding the convergence properties of various inverse methods. The relative lack of success of electromagnetic inversion techniques is partly attributable to the difficulties in the kernel forward modeling software. These difficulties come in two broad classes: (1) Completeness and robustness, and (2) convergence, execution time and model simplicity. If such problems exist in the forward modeling kernel, it was demonstrated that inversion can fail to generate reasonable results. It was suggested that classical inversion techniques, which are based on minimizing a norm of the error between data and the simulated data, will only be successful when these difficulties in forward modeling kernels are properly dealt with. 4 refs., 5 figs.

  12. Electromagnetic field and cosmic censorship

    CERN Document Server

    Düztaş, Koray

    2013-01-01

    We construct a gedanken experiment in which an extremal Kerr black hole interacts with a test electromagnetic field. Using Teukolsky's solutions for electromagnetic perturbations in Kerr spacetime, and the conservation laws imposed by the energy momentum tensor of the electromagnetic field and the Killing vectors of the spacetime, we prove that this interaction cannot convert the black hole into a naked singularity, thus cosmic censorship conjecture is not violated in this case.

  13. Electromagnetic Scattering and Material Characterization

    CERN Document Server

    Omar, Abbas

    2011-01-01

    Based on the author's more-than 30 years of experience, this first-of-its-kind volume presents a comprehensive and systematic analysis of electromagnetic fields and their scattering by material objects. The book considers all three categories of scattering environments commonly used for material measurements – unbounded regions, waveguides, and cavity resonators. The book covers such essential topics as electromagnetic field propagation, radiation, and scattering, containing mathematically rigorous approaches for the computation of electromagnetic fields and the explanation of their behavior.

  14. Electromagnetic Meissner-Effect Launcher

    Science.gov (United States)

    Robertson, Glen A.

    1990-01-01

    Proposed electromagnetic Meissner-effect launching apparatus differs from previous electromagnetic launchers; no need for electromagnet coil on projectile. Result, no need for brush contacts and high-voltage commutation equipment to supply current directly to projectile coil, or for pulse circuitry to induce current in projectile coil if brush contacts not used. Compresses magnetic field surrounding rear surface of projectile, creating gradient of magnetic pressure pushing projectile forward.

  15. Um estudo piloto na avaliação das estratégias posturais em jovens e idosos usando um sistema eletromagnético tridimensional A pilot study on the evaluation of postural strategies in young and elderly subjects using a tridimensional electromagnetic system

    Directory of Open Access Journals (Sweden)

    José Ailton Oliveira Carneiro

    2013-04-01

    Full Text Available Para manter o equilíbrio postural, algumas estratégias posturais são normalmente usadas. OBJETIVO: Avaliar as estratégias posturais de jovens e idosos em diferentes condições sensoriais usando um sistema de sensores eletromagnéticos tridimensionais posicionados na primeira vértebra torácica e região sacral. Também reportamos valores de oscilação postural dos jovens e idosos. MÉTODO: Estudo transversal observacional. Participaram do estudo 25 jovens e 16 idosas. O equipamento PolhemusTM com dois sensores foi usado para avaliar os parâmetros de oscilação postural (deslocamento máximo, velocidade média e trajetória. A aquisição dos dados foi realizada com os sujeitos em pé, realizando um teste de 90 segundos para as quatro condições sensoriais: olhos abertos e fechados nas superfícies estável e instável. RESULTADOS: Os sensores 1 e 2 apresentaram alta correlação cruzada em todas as condições sensoriais para ambos os grupos (r > 0.99; p One resorts to various postural strategies while attempting to maintain balance. OBJECTIVE: To assess the postural strategies adopted by young and elderly subjects in varying sensory conditions by using a system of tridimensional electromagnetic sensors positioned on the projection of the first thoracic vertebra and on the sacral region. Postural oscillation values for young and elderly subjects were also reported. METHOD: This observational cross-sectional study enrolled 25 young and 16 elderly individuals. A PolhemusTM device equipped with two sensors was used to assess postural oscillation parameters (maximum displacement, mean velocity, and trajectory. Data acquisition was carried out with subjects standing while undergoing a 90-second test in four sensory conditions: eyes opened, eyes closed, on a stable surface, and on an unstable surface. RESULTS: Sensors 1 and 2 presented significant cross-correlations in all sensory conditions for both groups (r > 0.99; p < 0.001. No

  16. Electromagnetic fields in biological systems

    National Research Council Canada - National Science Library

    Lin, James C

    2012-01-01

    "Focusing on exposure, induced fields, and absorbed energy, this volume covers the interaction of electromagnetic fields and waves with biological systems, spanning static fields to terahertz waves...

  17. Electromagnetic waves in stratified media

    CERN Document Server

    Wait, James R; Fock, V A; Wait, J R

    2013-01-01

    International Series of Monographs in Electromagnetic Waves, Volume 3: Electromagnetic Waves in Stratified Media provides information pertinent to the electromagnetic waves in media whose properties differ in one particular direction. This book discusses the important feature of the waves that enables communications at global distances. Organized into 13 chapters, this volume begins with an overview of the general analysis for the electromagnetic response of a plane stratified medium comprising of any number of parallel homogeneous layers. This text then explains the reflection of electromagne

  18. Battlefield Electromagnetic Environments Office (BEEO)

    Data.gov (United States)

    Federal Laboratory Consortium — The Battlefield Electromagnetic Environments Office (BEEO) develops, maintains, and operates the Army Materiel Command (AMC) databases for spectrum management, per...

  19. Method of moments in electromagnetics

    CERN Document Server

    Gibson, Walton C

    2007-01-01

    Responding to the need for a clear, up-to-date introduction to the field, The Method of Moments in Electromagnetics explores surface integral equations in electromagnetics and presents their numerical solution using the method of moments (MOM) technique. It provides the numerical implementation aspects at a nuts-and-bolts level while discussing integral equations and electromagnetic theory at a higher level. The author covers a range of topics in this area, from the initial underpinnings of the MOM to its current applications. He first reviews the frequency-domain electromagnetic theory and t

  20. Electromagnetic Processes in strong Crystalline Fields

    CERN Multimedia

    2007-01-01

    We propose a number of new investigations on aspects of radiation from high energy electron and positron beams (10-300 GeV) in single crystals and amorphous targets. The common heading is radiation emission by electrons and positrons in strong electromagnetic fields, but as the setup is quite versatile, other related phenomena in radiation emission can be studied as well. The intent is to clarify the role of a number of important aspects of radiation in strong fields as e.g. observed in crystals. We propose to measure trident 'Klein-like' production in strong crystalline fields, 'crystalline undulator' radiation, 'sandwich' target phenomena, LPM suppression of pair production as well as axial and planar effects in contributions of spin to the radiation.

  1. Apparatus and method for the simultaneous detection of neutrons and ionizing electromagnetic radiation

    Science.gov (United States)

    Bell, Zane W.

    2000-01-01

    A sensor for simultaneously detecting neutrons and ionizing electromagnetic radiation comprising: a sensor for the detection of gamma radiation, the sensor defining a sensing head; the sensor further defining an output end in communication with the sensing head; and an exterior neutron-sensitive material configured to form around the sensing head; wherein the neutron-sensitive material, subsequent to the capture of the neutron, fissions into an alpha-particle and a .sup.7 Li ion that is in a first excited state in a majority of the fissions, the first excited state decaying via the emission of a single gamma ray at 478 keV which can in turn be detected by the sensing head; and wherein the sensing head can also detect the ionizing electromagnetic radiation from an incident radiation field without significant interference from the neutron-sensitive material. A method for simultaneously detecting neutrons and ionizing electromagnetic radiation comprising the steps of: providing a gamma ray sensitive detector comprising a sensing head and an output end; conforming an exterior neutron-sensitive material configured to form around the sensing head of the detector; capturing neutrons by the sensing head causing the neutron-sensitive material to fission into an alpha-particle and a .sup.7 Li ion that is in a first excited state in a majority of the fissions, the state decaying via the emission of a single gamma ray at 478 keV; sensing gamma rays entering the detector through the neutron-sensitive material; and producing an output through a readout device coupled to the output end; wherein the detector provides an output which is proportional to the energy of the absorbed ionizing electromagnetic radiation.

  2. Tolerance of the Head and Neck to -Gx Inertial Loading of the Head

    Science.gov (United States)

    1981-03-09

    cervical muscles reduced the inci- dence of "concussion" symptons produced in this animal, Collars on monkeys subjected to flexion producing occipital...muscles reduced the incidence of "concussion" symptoms produced in this animal. Collars on monkeys subjected to flexion producing occipital impacts, were...4 In a repeat run to determine what caused the losA of un- consciousness in Run 133, Stapp, with head held down to aviod amplification of head

  3. Handbook of electromagnetic compatibility

    CERN Document Server

    1995-01-01

    This""know-how""book gives readers a concise understanding of the fundamentals of EMC, from basic mathematical and physical concepts through present, computer-age methods used in analysis, design, and tests. With contributions from leading experts in their fields, the text provides a comprehensive overview. Fortified with information on how to solve potential electromagnetic interference (EMI) problems that may arise in electronic design, practitioners will be betterable to grasp the latest techniques, trends, and applications of this increasingly important engineering discipline.Handbook of E

  4. Introduction to electromagnetic engineering

    CERN Document Server

    Harrington, Roger E

    2003-01-01

    This study of electromagnetic theory introduces students to a broad range of quantities and concepts, imparting the necessary vector analysis and associated mathematics and reinforcing its teachings with several elementary field problems. Based on circuit theory rather than on the classical force-relationship approach, the text uses the theory of electric circuits to provide a system of experiments already familiar to the electrical engineer; a series of field concepts are then introduced as a logical extension of circuit theory. Virtually unobtainable elsewhere, this text was written by a pr

  5. Electromagnetic Meissner effect launcher

    Science.gov (United States)

    Robertson, Glen A. (Inventor)

    1991-01-01

    An electromagnetic projectile launcher provides acceleration of a superconducting projectile through the diamagnetic repulsion of the superconducting projectile. A superconducting layer is provided aft of the projectile, either directly on the projectile or on a platform upon which the projectile is carried, and a traveling magnetic field is caused to propagate along a magnetic field drive coil in which the projectile is disposed. The resulting diamagnetic repulsion between the superconducting projectile and the traveling magnetic field causes the projectile to be propelled along the coil. In one embodiment, a segmented drive coil is used to generate the traveling magnetic field.

  6. Experimental and computational investigation of an electromagnetic pump used for manufacturing aluminium parts

    Science.gov (United States)

    Morinigo, D.; Rodrigues, M. A.; Rivas, A.; Duque, O.; Vazquez, V.; Maroto, J. A.; Cuesta, R.

    2007-03-01

    An experimental and computational investigation was carried out on an electromagnetic pump for molten aluminum. The electromagnetic pump is a MHD device to drive molten metals by means of electromagnetic fields and without mechanical parts in contact with the metal at high temperature. An exact computer simulation of the electromagnetic pump would require the simultaneous solution of electromagnetic and fluid dynamics problems. However, in this study we divide the simulation into two independent stages. First, the electromagnetic system is simulated by ANSYS considering the secondary of the pump as a solid. This simulation is experimentally validated in a test bed with a solid secondary replacing the molten metal. Secondly, a 3D field of electromagnetic forces provided by the ANSYS simulation is imported into the FLUENT CFD code to simulate the fluid dynamic problem, considering now the secondary of the pump as a liquid. This second simulation is also experimentally validated by measuring the static head provided by the pump. This simulation process is valid only if the electromagnetic system and the fluid dynamic problem are uncoupled, which has been verified by calculating the magnetic Reynolds number and the interaction parameter. Tables 4, Figs 14, Refs 15.

  7. Head injury - first aid

    Science.gov (United States)

    ... medlineplus.gov/ency/article/000028.htm Head injury - first aid To use the sharing features on this page, ... a concussion can range from mild to severe. First Aid Learning to recognize a serious head injury and ...

  8. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... the head is typically used to detect: bleeding, brain injury and skull fractures in patients with head injuries. ... hard time staying still, are claustrophobic or have chronic pain, you may find a CT exam to ...

  9. Head and face reconstruction

    Science.gov (United States)

    ... medlineplus.gov/ency/article/002980.htm Head and face reconstruction To use the sharing features on this page, please enable JavaScript. Head and face reconstruction is surgery to repair or reshape deformities ...

  10. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... the limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, ... than regular radiographs (x-rays). top of page What are some common uses of the procedure? CT ...

  11. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... for Brain Tumors Radiation Therapy for Head and Neck Cancer Others American Stroke Association National Stroke Association ... Computer Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine ...

  12. Newborn head molding

    Science.gov (United States)

    Newborn cranial deformation; Molding of the newborn's head; Neonatal care - head molding ... The bones of a newborn baby's skull are soft and flexible, with gaps between the plates of bone. The spaces between the bony plates of ...

  13. Porcine head response to blast

    Directory of Open Access Journals (Sweden)

    Jay eShridharani

    2012-05-01

    Full Text Available Recent studies have shown an increase in the frequency of traumatic brain injuries related to blast exposure. However, the mechanisms that cause blast neurotrauma are unknown. Blast neurotrauma research using computational models has been one method to elucidate that response of the brain in blast, and to identify possible mechanical correlates of injury. However, model validation against experimental data is required to ensure that the model output is representative of in vivo biomechanical response. This study exposed porcine subjects to primary blast overpressures generated using a compressed-gas shock tube. Shock tube blasts were directed to the unprotected head of each animal while the lungs and thorax were protected using ballistic protective vests similar to those employed in theater. The test conditions ranged from 110-740 kPa peak incident overpressure with scaled durations from 1.3-6.9 ms and correspond approximately with a 50% injury risk for brain bleeding and apnea in a ferret model scaled to porcine exposure. The bulk head acceleration and the pressure at the surface of the head and in the cranial cavity were measured. Immediately after the blast, 5 of the 20 animals tested were apneic. Three subjects recovered without intervention within thirty seconds and the remaining two recovered within 8 minutes following bagging and administration of the respiratory stimulant doxapram. Gross examination of the brain revealed no indication of bleeding. Intracranial pressures ranged from 80-685 kPa as a result of the blast and were notably lower than the shock tube reflected pressures of 300-2830 kPa, indicating pressure attenuation by the skull up to a factor of 8.4. Peak head accelerations were measured from 385-3845 G’s and were well correlated with peak incident overpressure (R2=0.90. One standard deviation corridors for the surface pressure, intracranial pressure, and head acceleration are presented to provide experimental data for

  14. Metamaterials beyond electromagnetism

    Science.gov (United States)

    Kadic, Muamer; Bückmann, Tiemo; Schittny, Robert; Wegener, Martin

    2013-12-01

    Metamaterials are rationally designed man-made structures composed of functional building blocks that are densely packed into an effective (crystalline) material. While metamaterials are mostly associated with negative refractive indices and invisibility cloaking in electromagnetism or optics, the deceptively simple metamaterial concept also applies to rather different areas such as thermodynamics, classical mechanics (including elastostatics, acoustics, fluid dynamics and elastodynamics), and, in principle, also to quantum mechanics. We review the basic concepts, analogies and differences to electromagnetism, and give an overview on the current state of the art regarding theory and experiment—all from the viewpoint of an experimentalist. This review includes homogeneous metamaterials as well as intentionally inhomogeneous metamaterial architectures designed by coordinate-transformation-based approaches analogous to transformation optics. Examples are laminates, transient thermal cloaks, thermal concentrators and inverters, ‘space-coiling’ metamaterials, anisotropic acoustic metamaterials, acoustic free-space and carpet cloaks, cloaks for gravitational surface waves, auxetic mechanical metamaterials, pentamode metamaterials (‘meta-liquids’), mechanical metamaterials with negative dynamic mass density, negative dynamic bulk modulus, or negative phase velocity, seismic metamaterials, cloaks for flexural waves in thin plates and three-dimensional elastostatic cloaks.

  15. Comparison between electroglottography and electromagnetic glottography

    Energy Technology Data Exchange (ETDEWEB)

    Titze, Ingo R. [Department of Speech Pathology and Audiology and National Center for Voice and Speech, The University of Iowa and the Denver Center for the Performing Arts, Iowa City, Iowa 52242 (United States); Story, Brad H. [Department of Speech Pathology and Audiology and National Center for Voice and Speech, The University of Iowa and the Denver Center for the Performing Arts, Iowa City, Iowa 52242 (United States); Burnett, Gregory C. [Department of Applied Science, University of California at Davis, and Lawrence Livermore National Laboratory, Livermore, California 94557 (United States); Holzrichter, John F. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Ng, Lawrence C. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Lea, Wayne A. [Speech Sciences Institute, Apple Valley, Minnesota 55124 (United States)

    2000-01-01

    Newly developed glottographic sensors, utilizing high-frequency propagating electromagnetic waves, were compared to a well-established electroglottographic device. The comparison was made on four male subjects under different phonation conditions, including three levels of vocal fold adduction (normal, breathy, and pressed), three different registers (falsetto, chest, and fry), and two different pitches. Agreement between the sensors was always found for the glottal closure event, but for the general wave shape the agreement was better for falsetto and breathy voice than for pressed voice and vocal fry. Differences are attributed to the field patterns of the devices. Whereas the electroglottographic device can operate only in a conduction mode, the electromagnetic device can operate in either the forward scattering (diffraction) mode or in the backward scattering (reflection) mode. Results of our tests favor the diffraction mode because a more favorable angle imposed on receiving the scattered (reflected) signal did not improve the signal strength. Several observations are made on the uses of the electromagnetic sensors for operation without skin contact and possibly in an array configuration for improved spatial resolution within the glottis. (c) 2000 Acoustical Society of America.

  16. Electromagnetic Environmental Effects System Testing

    Science.gov (United States)

    2013-11-20

    K-1 L. INTRA SYSTEM ELECTROMAGNETIC COMPATIBILITY ( EMC ) SOURCE/VICTIM ................... L-1 M. PERSONNEL...TEMPEST and test guidance for the addition of test procedures for implementing Electromagnetic Compatibility ( EMC ), Radiated Emissions (RE...for Grounds and Bonds is not addressed since it is sufficiently discussed in MIL-STD-464C. For Shielding Effectiveness, reference American Society

  17. Exploration of the Electromagnetic Environment

    Science.gov (United States)

    Fullekrug, M.

    2009-01-01

    The electromagnetic environment is composed of electric and magnetic fields which result from man-made and natural sources. An elementary experiment is described to explore the electromagnetic environment by measuring electric fields in the frequency range from approximately equal to 10 to 24 000 Hz. The equipment required to conduct the…

  18. Electromagnetic actuation in MEMS switches

    DEFF Research Database (Denmark)

    Oliveira Hansen, Roana Melina de; Mátéfi-Tempfli, Mária; Chemnitz, Steffen

    . Electromagnetic actuation is a very promising approach to operate such MEMS and Power MEMS devices, due to the long range, reproducible and strong forces generated by this method, among other advantages. However, the use of electromagnetic actuation in such devices requires the use of thick magnetic films, which...

  19. Electromagnetic compatibility in power electronics

    CERN Document Server

    Costa , François; Revol , Bertrand

    2014-01-01

    Scientists largely attribute the recent deterioration of the electromagnetic environment to power electronics. This realization has spurred the study of methodical approaches to electromagnetic compatibility designs as explored in this text. The book addresses major challenges, such as handling numerous parameters vital to predicting electro magnetic effects and achieving compliance with line-harmonics norms, while proposing potential solutions.

  20. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... top of page What are some common uses of the procedure? CT scanning of the head is ...

  1. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Computed tomography (CT) of the head uses special x-ray equipment to help assess head injuries, severe headaches, dizziness, and other symptoms of ... content. Related Articles and Media Radiation Dose in X-Ray and CT ... Perfusion of the Head CT Angiography (CTA) Stroke Brain Tumors Computer Tomography ( ...

  2. Electromagnetic Interference (EMI) and TEMPEST Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Electromagnetic Interference (EMI), Electromagnetic Compatibility (EMC) and TEMPEST testing are conducted at EPG's Blacktail Canyon Test Facility in one of its two...

  3. Hybrid synchronous motor electromagnetic torque research

    Directory of Open Access Journals (Sweden)

    Suvorkova Elena E.

    2014-01-01

    Full Text Available Electromagnetic field distribution models in reluctance and permanent magnet parts were made by means of Elcut. Dependences of electromagnetic torque on torque angle were obtained.

  4. Radiofrequency Electromagnetic Field Map of Timisoara

    National Research Council Canada - National Science Library

    N. Stefu; I. Solyom; A. Arama

    2015-01-01

    There are many electromagnetic field (EMF) sources nowadays acting simultaneously, especially in urban areas, making the theoretical estimation of electromagnetic power at ground level very difficult...

  5. Design and fabrication of a realistic anthropomorphic heterogeneous head phantom for MR purposes.

    Directory of Open Access Journals (Sweden)

    Sossena Wood

    Full Text Available The purpose of this study is to design an anthropomorphic heterogeneous head phantom that can be used for MRI and other electromagnetic applications.An eight compartment, physical anthropomorphic head phantom was developed from a 3T MRI dataset of a healthy male. The designed phantom was successfully built and preliminarily evaluated through an application that involves electromagnetic-tissue interactions: MRI (due to it being an available resource. The developed phantom was filled with media possessing electromagnetic constitutive parameters that correspond to biological tissues at ~297 MHz. A preliminary comparison between an in-vivo human volunteer (based on whom the anthropomorphic head phantom was created and various phantoms types, one being the anthropomorphic heterogeneous head phantom, were performed using a 7 Tesla human MRI scanner.Echo planar imaging was performed and minimal ghosting and fluctuations were observed using the proposed anthropomorphic phantom. The magnetic field distributions (during MRI experiments at 7 Tesla and the scattering parameter (measured using a network analyzer were most comparable between the anthropomorphic heterogeneous head phantom and an in-vivo human volunteer.The developed anthropomorphic heterogeneous head phantom can be used as a resource to various researchers in applications that involve electromagnetic-biological tissue interactions such as MRI.

  6. Gravitational scattering of electromagnetic radiation

    Science.gov (United States)

    Brooker, J. T.; Janis, A. I.

    1980-01-01

    The scattering of electromagnetic radiation by linearized gravitational fields is studied to second order in a perturbation expansion. The incoming electromagnetic radiation can be of arbitrary multipole structure, and the gravitational fields are also taken to be advanced fields of arbitrary multipole structure. All electromagnetic multipole radiation is found to be scattered by gravitational monopole and time-varying dipole fields. No case has been found, however, in which any electromagnetic multipole radiation is scattered by gravitational fields of quadrupole or higher-order multipole structure. This lack of scattering is established for infinite classes of special cases, and is conjectured to hold in general. The results of the scattering analysis are applied to the case of electromagnetic radiation scattered by a moving mass. It is shown how the mass and velocity may be determined by a knowledge of the incident and scattered radiation.

  7. Automated Catheter Navigation With Electromagnetic Image Guidance.

    Science.gov (United States)

    Jaeger, Herman A; Nardelli, Pietro; O'Shea, Conor; Tugwell, Josef; Khan, Kashif A; Power, Timothy; O'Shea, Michael; Kennedy, Marcus P; Cantillon-Murphy, Padraig

    2017-08-01

    This paper describes a novel method of controlling an endoscopic catheter by using an automated catheter tensioning system with the objective of providing clinicians with improved manipulation capabilities within the patient. Catheters are used in many clinical procedures to provide access to the cardiopulmonary system. Control of such catheters is performed manually by the clinicians using a handle, typically actuating a single or opposing set of pull wires. Such catheters are generally actuated in a single plane, requiring the clinician to rotate the catheter handle to navigate the system. The automation system described here allows closed-loop control of a custom bronchial catheter in tandem with an electromagnetic tracking of the catheter tip and image guidance by using a 3D Slicer. An electromechanical drive train applies tension to four pull wires to steer the catheter tip, with the applied force constantly monitored through force sensing load cells. The applied tension is controlled through a PC connected joystick. An electromagnetic sensor embedded in the catheter tip enables constant real-time position tracking, whereas a working channel provides a route for endoscopic instruments. The system is demonstrated and tested in both a breathing lung model and a preclinical animal study. Navigation to predefined targets in the subject's airways by using the joystick while using virtual image guidance and electromagnetic tracking was demonstrated. Average targeting times were 29 and 10 s, respectively, for the breathing lung and live animal studies. This paper presents the first reported remote controlled bronchial working channel catheter utilizing electromagnetic tracking and has many implications for future development in endoscopic and catheter-based procedures.

  8. Vestibulopathy and age effects on head stability during chair rise.

    Science.gov (United States)

    McGibbon, C A; Krebs, D E; Scarborough, D M

    2001-01-01

    It is unknown how vestibular dysfunction and age differentially affect balance control during functional activities. The objective of this study was to gain insight into the effects of age and vestibulopathy on head control when rising from a chair. Head relative to trunk (head-on-trunk) sagittal plane angular and linear control strategies were studied in patients with bilateral vestibular hypofunction (BVH) and in healthy subjects aged 30-80 years. A two-way analysis of variance was used to compare head-on-trunk kinematics by age (young vs elderly) and diagnosis (healthy vs BVH) at the time of liftoff from the seat. Angular control strategies differed with age but not diagnosis: young (healthy and BVH) subjects stabilized head rotations in space while elderly (healthy and BVH) subjects stabilized head rotations on the trunk. In contrast, linear control strategies differed by diagnosis but not age: BVH subjects (young and old) allowed a greater rate of head-on-trunk translation while healthy subjects (young and old) inhibited such translations. Young BVH subjects stabilized head-in-space rotations (as did young healthy subjects) without a functioning vestibular system, suggesting cervicocollic reflex and/or other sensory compensation for vestibular loss. Elderly BVH subjects stabilized head rotation with respect to the trunk, as did healthy elders, but did not stabilize head-on-trunk translations, suggesting a reliance on passive mechanical responses of the neck to sense head movements. We conclude that compensation strategies used by patients with vestibulopathy are age-dependent and appear to be more tractable in the younger BVH patient.

  9. Electromagnetic-emission diagnostics of dielectric materials under ultrasonic loading

    Science.gov (United States)

    Chakhlov, V. L.; Simanchuk, V. I.; Kargapol'Tsev, A. V.

    1993-08-01

    The electromagnetic-emission diagnostic inspection of solid dielectrics subjected to ultrasonic loading created by a pulsed laser beam of nanosecond duration is investigated experimentally. The experimental apparatus and procedure are described. It is shown that the procedure is an effective diagnostic tool for monitoring the electrical state and structure of solid dielectric materials.

  10. Magnetic Resonance Imaging (MRI) -- Head

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head ... limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is ...

  11. Eye-Head Coordination for Visual Cognitive Processing

    Science.gov (United States)

    Fang, Yu; Nakashima, Ryoichi; Matsumiya, Kazumichi; Kuriki, Ichiro; Shioiri, Satoshi

    2015-01-01

    We investigated coordinated movements between the eyes and head (“eye-head coordination”) in relation to vision for action. Several studies have measured eye and head movements during a single gaze shift, focusing on the mechanisms of motor control during eye-head coordination. However, in everyday life, gaze shifts occur sequentially and are accompanied by movements of the head and body. Under such conditions, visual cognitive processing influences eye movements and might also influence eye-head coordination because sequential gaze shifts include cycles of visual processing (fixation) and data acquisition (gaze shifts). In the present study, we examined how the eyes and head move in coordination during visual search in a large visual field. Subjects moved their eyes, head, and body without restriction inside a 360° visual display system. We found patterns of eye-head coordination that differed those observed in single gaze-shift studies. First, we frequently observed multiple saccades during one continuous head movement, and the contribution of head movement to gaze shifts increased as the number of saccades increased. This relationship between head movements and sequential gaze shifts suggests eye-head coordination over several saccade-fixation sequences; this could be related to cognitive processing because saccade-fixation cycles are the result of visual cognitive processing. Second, distribution bias of eye position during gaze fixation was highly correlated with head orientation. The distribution peak of eye position was biased in the same direction as head orientation. This influence of head orientation suggests that eye-head coordination is involved in gaze fixation, when the visual system processes retinal information. This further supports the role of eye-head coordination in visual cognitive processing. PMID:25799510

  12. Measurement Evaluation of EMF Effect by Mobile Phone on Human Head Phantom

    Directory of Open Access Journals (Sweden)

    Zuzana Psenakova

    2008-01-01

    Full Text Available Interaction of electromagnetic field (EMF with environment and with tissue of human beings is still under discussion and many research teams are investigating it. One of electromagnetic devices is mobile phone. There are many simulations and measurements on models or phantoms of human body to biological effect of EMF acquirement. This paper deals with laboratory measurement evaluation of EMF effect by mobile phone on human head phantom.

  13. Electromagnetic fields and life

    CERN Document Server

    Presman, A S

    1970-01-01

    A broad region of the electromagnetic spectrum long assumed to have no influence on living systems under natural conditions has been critically re-examined over the past decade. This spectral region extends from the superhigh radio frequencies, through de­ creasing frequencies, to and including essentially static electric and magnetic fields. The author of this monograph, A. S. Presman, has reviewed not only the extensive Russian literatur!;"l, but also al­l most equally comprehensively the non-Russian literature, dealing with biological influences of these fields. Treated also is literature shedding some light on possible theoretical foundations for these phenomena. A substantial, rapidly increasing number of studies in many laboratories and countries has now clearly established bio­ logical influences which are independent of the theoretically predictable, simple thermal effects. Indeed many of the effects are produced by field strengths very close to those within the natural environment. The author has,...

  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. Electromagnetic scattering theory

    Science.gov (United States)

    Bird, J. F.; Farrell, R. A.

    1986-01-01

    Electromagnetic scattering theory is discussed with emphasis on the general stochastic variational principle (SVP) and its applications. The stochastic version of the Schwinger-type variational principle is presented, and explicit expressions for its integrals are considered. Results are summarized for scalar wave scattering from a classic rough-surface model and for vector wave scattering from a random dielectric-body model. Also considered are the selection of trial functions and the variational improvement of the Kirchhoff short-wave approximation appropriate to large size-parameters. Other applications of vector field theory discussed include a general vision theory and the analysis of hydromagnetism induced by ocean motion across the geomagnetic field. Levitational force-torque in the magnetic suspension of the disturbance compensation system (DISCOS), now deployed in NOVA satellites, is also analyzed using the developed theory.

  16. Focusing of electromagnetic waves

    Energy Technology Data Exchange (ETDEWEB)

    Dhayalan, V.

    1996-12-31

    The focusing of electromagnetic waves inside a slab has been examined together with two special cases in which the slab is reduced to a single interface or a single medium. To that end the exact solutions for the fields inside a layered medium have been used, given in terms of the outside current source in order to obtain the solutions for the focused electric field inside a slab. Both exact and asymptotic solutions of the problem have been considered, and the validity of the latter has been discussed. The author has developed a numerical algorithm for evaluation of the diffraction integral with special emphasis on reducing the computing time. The numerical techniques in the paper can be readily applied to evaluate similar diffraction integrals occurring e.g. in microstrip antennas. 46 refs.

  17. Solved problems in electromagnetics

    CERN Document Server

    Salazar Bloise, Félix; Bayón Rojo, Ana; Gascón Latasa, Francisco

    2017-01-01

    This book presents the fundamental concepts of electromagnetism through problems with a brief theoretical introduction at the beginning of each chapter. The present book has a strong  didactic character. It explains all the mathematical steps and the theoretical concepts connected with the development of the problem. It guides the reader to understand the employed procedures to learn to solve the exercises independently. The exercises are structured in a similar way: The chapters begin with easy problems increasing progressively in the level of difficulty. This book is written for students of physics and engineering in the framework of the new European Plans of Study for Bachelor and Master and also for tutors and lecturers. .

  18. On steady electromagnetic equilibria

    Science.gov (United States)

    Lehnert, B.

    1986-12-01

    The existence of steady electromagnetic equilibrium states predicted by an extended Lorentz invariant formulation of Maxwell's equations is analyzed. General equilibrium solutions are outlined which lead to integrated field quantities of the system, such as total charge qo, magnetic moment Mo, mass mo and angular momentum so. The quantization of moMo/qo in terms of Bohr magnetons is shown to be equivalent to the proposed resonance condition of circulating self-confined radiation. Exact equilibrium solutions were deduced in two simple cases, thereby leading to a so of the same order as that of the electron, and to a qo one order of magnitude larger than the electronic charge. A variational procedure is suggested in search for states of minimum charge, under the subsidiary quantum conditions on moMo/qo and so, i.e., by varying the profile of the electric space charge distribution.

  19. Nucleon Electromagnetic Form Factors

    Energy Technology Data Exchange (ETDEWEB)

    Marc Vanderhaeghen; Charles Perdrisat; Vina Punjabi

    2007-10-01

    There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has greatly improved by performing double polarization experiments, in comparison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at JLab, MAMI, and MIT-Bates. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed, including the recent progress in the determination of the valence quark generalized parton distributions of the nucleon, as well as the steady rate of improvements made in the lattice QCD calculations.

  20. Adaptive algorithm of magnetic heading detection

    Science.gov (United States)

    Liu, Gong-Xu; Shi, Ling-Feng

    2017-11-01

    Magnetic data obtained from a magnetic sensor usually fluctuate in a certain range, which makes it difficult to estimate the magnetic heading accurately. In fact, magnetic heading information is usually submerged in noise because of all kinds of electromagnetic interference and the diversity of the pedestrian’s motion states. In order to solve this problem, a new adaptive algorithm based on the (typically) right-angled corridors of a building or residential buildings is put forward to process heading information. First, a 3D indoor localization platform is set up based on MPU9250. Then, several groups of data are measured by changing the experimental environment and pedestrian’s motion pace. The raw data from the attached inertial measurement unit are calibrated and arranged into a time-stamped array and written to a data file. Later, the data file is imported into MATLAB for processing and analysis using the proposed adaptive algorithm. Finally, the algorithm is verified by comparison with the existing algorithm. The experimental results show that the algorithm has strong robustness and good fault tolerance, which can detect the heading information accurately and in real-time.

  1. Electromagnetic properties of neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Ould-Saada, F. [Zurich Univ. (Switzerland). Inst. fuer Physik

    1996-11-01

    Electromagnetic properties of neutrinos and their implications are discussed, and the experimental situation summarised. Spin precession in solar magnetic fields presents a solution of the solar neutrino problem. A magnetic moment, {mu}{sub {nu}}, of the order of 10{sup -11} {mu}{sub B} would be needed. In the simplest extension of the standard model, with no-vanishing neutrino masses, dipole moment interactions are allowed through higher order processes. A neutrino mass of {approx_equal}10 eV would give {mu}{sub {nu}}{approx_equal}10{sup -18} {mu}{sub B}, much smaller than the present experimental upper limit of 2x10{sup -10} {mu}{sub B}. Although model-dependent, upper bounds on dipole moments from astrophysics and cosmology are 10 to 100 times more stringent. Any values of {mu}{sub {nu}}, larger than the SM predictions, would then signal the onset of new physics. Among the processes sensitive to the magnetic moment, {nu}e{sup -} scattering presents two advantages: it is a pure weak, theoretically well understood process, and the recoil electron can be easily measured. A hypothetical electromagnetic contribution to the cross-section would dominate at low energies. A low background detector, MUNU, being built at the Bugey nuclear reactor is presented.It is based on a gas TPC, surrounded by a scintillator. The threshold on the electron recoil energy can be set very low, around 500 keV, giving the experiment a good sensitivity to the magnetic moment of the {nu}{sub e}, extending down to 2x10{sup -11} {mu}{sub B}. (author) 15 figs., 5 tabs., 96 refs.

  2. KEKB electromagnet power supply

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Masato; Kubo, Tadashi [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

    2000-01-01

    Numbers of electromagnet power supply for KEKB are 2,243 except BT. To satisfy stability, DAC in the current control circuit, current detector, R and D of small thermostatic bath and a calibration method of current using CPU were introduced. They satisfied needs. With producing R and D apparatus of switching source, problems of ripple, stability and noise were solved, so that we began mass production. In this paper, many kinds of R and D and performance and troubles after operation of KEKB power source are described. A plan of design of power supply consisted of seven items such as high accuracy, serial communication of interface, small type, high affectivity, easy maintenance, independence of current setting and current detector for monitor and control of radiation and conduction noise of switching power supply. These items were satisfied by development of interface board of ARCNET communication, introduction of double buffer method for interface through CPU, power supply unit by air-cooled method using a switching method and small thermostatic oven for bending and quadrupole electromagnet. R and D of DCCT, burden and shunt resistance, DAC, thermostatic bath, power supply, offset and gain calibration by double buffer method, specification of power supply, various kinds of measurements of mass production apparatus at rising, after long operation and problems before and after operation are reported. The results of R and D made satisfy the specification of stability and ripple of power supply. Although many switching power supply were operated, there was no noise and troubles at the initial period decreased. However, in order to use many power supply, the performance measurement and maintenance are very important at long shut down. (S.Y.)

  3. Case Study Regarding the Design of a Direct Current Electromagnet for the MIG Welding of Metallic Materials Part I: Description of the Welding Methods and Preliminary Calculus of the Electromagnet

    Directory of Open Access Journals (Sweden)

    Tudorel Ene

    2016-10-01

    Full Text Available The paper refers to the design of a direct current electromagnet, located on the head of a swan neck welding gun of a MIG welding equipment and used for magnetising the rotation space of two additional electric arches, in order to preheat the electrode wire and of the protective gas, partially turned into plasma jet. One describes the MIG welding method in which the electromagnet is used as well as its preliminary calculus.

  4. Expanding subjectivities

    DEFF Research Database (Denmark)

    Lundgaard Andersen, Linda; Soldz, Stephen

    2012-01-01

    A major theme in recent psychoanalytic thinking concerns the use of therapist subjectivity, especially “countertransference,” in understanding patients. This thinking converges with and expands developments in qualitative research regarding the use of researcher subjectivity as a tool to understa...

  5. Electromagnetic environment and telecommunications: towards a cognitive electromagnetic compatibility

    Science.gov (United States)

    Zeddam, Ahmed; Avril, Gautier; Tlich, Mohamed

    2009-01-01

    This article deals with the electromagnetic environment management problem within the context of high speed digital transmissions deployed in wired telecommunication networks. Traditionally, Electromagnetic Compatibility (EMC) is assured by filtering for better electromagnetic immunity, and by cable shielding for emission limitation. However, like cognitive radio, we can also, for high speed wired transmissions, treat the EMC as an intelligent and autonomous system capable of perceiving its environment, interpreting it, making suited decisions, and reacting according to the constraints related to the electromagnetic environment. In this context, some application examples are here given in order to illustrate this evolution towards a cognitive EMC in wired networks. To cite this article: A. Zeddam et al., C. R. Physique 10 (2009).

  6. Electromagnetic segregation of cast parts

    Science.gov (United States)

    Langejurgen, M.; Nacke, B.

    2007-06-01

    The Electromagnetic Induced Segregation (EIS) of cast parts is an innovative technology for diecasting aluminium alloys. Using numerical simulation, an inductor system has been developed to produce a primary silicon concentration gradient during casting. The report shows the advantages of numerical simulation in research and development. A suitable inductor has been designed and its electromagnetic field optimized for the EIS. The numerical model is 2D for geometries with cylindrical symmetry and 3D for non-symmetric products. The inductor system is implemented in a pilot installation. With the metallurgical results, the interaction between the electromagnetic field and the location of primary silicon is investigated. Figs 7, Refs 1.

  7. Differential forms on electromagnetic networks

    CERN Document Server

    Balasubramanian, N V; Sen Gupta, D P

    2013-01-01

    Differential Forms on Electromagnetic Networks deals with the use of combinatorial techniques in electrical circuit, machine analysis, and the relationship between circuit quantities and electromagnetic fields. The monograph is also an introduction to the organization of field equations by the methods of differential forms. The book covers topics such as algebraic structural relations in an electric circuit; mesh and node-pair analysis; exterior differential structures; generalized Stoke's theorem and tensor analysis; and Maxwell's electromagnetic equation. Also covered in the book are the app

  8. Electromagnetic transients in power cables

    CERN Document Server

    da Silva, Filipe Faria

    2013-01-01

    From the more basic concepts to the most advanced ones where long and laborious simulation models are required, Electromagnetic Transients in Power Cables provides a thorough insight into the study of electromagnetic transients and underground power cables. Explanations and demonstrations of different electromagnetic transient phenomena are provided, from simple lumped-parameter circuits to complex cable-based high voltage networks, as well as instructions on how to model the cables.Supported throughout by illustrations, circuit diagrams and simulation results, each chapter contains exercises,

  9. A primer on electromagnetic fields

    CERN Document Server

    Frezza, Fabrizio

    2015-01-01

    This book is a concise introduction to electromagnetics and electromagnetic fields that covers the aspects of most significance for engineering applications by means of a rigorous, analytical treatment. After an introduction to equations and basic theorems, topics of fundamental theoretical and applicative importance, including plane waves, transmission lines, waveguides, and Green's functions, are discussed in a deliberately general way. Care has been taken to ensure that the text is readily accessible and self-consistent, with conservation of the intermediate steps in the analytical derivations. The book offers the reader a clear, succinct course in basic electromagnetic theory. It will also be a useful lookup tool for students and designers.

  10. Finite Element Modeling of scattered electromagnetic waves for stroke analysis.

    Science.gov (United States)

    Priyadarshini, N; Rajkumar, E R

    2013-01-01

    Stroke has become one of the leading causes of mortality worldwide and about 800 in every 100,000 people suffer from stroke each year. The occurrence of stroke is ranked third among the causes of acute death and first among the causes for neurological dysfunction. Currently, Neurological examinations followed by medical imaging with CT, MRI or Angiography are used to provide better identification of the location and the type of the stroke, however they are neither fast, cost-effective nor portable. Microwave technology has emerged to complement these modalities to diagnose stroke as it is sensitive to the differences between the distinct dielectric properties of the brain tissues and blood. This paper investigates the possibility of diagnosing the type of stroke using Finite Element Analysis (FEA). The object of interest is a simulated head phantom with stroke, created with its specifying material characteristics like electrical conductivity and relative permittivity. The phantom is then placed in an electromagnetic field generated by a dipole antenna radiating at 1 GHz. The FEM forward model solver computes the scattered electromagnetic field by finding the solution for the Maxwell's wave equation in the head volume. Subsequently the inverse scattering problem is solved using the Contrast Source Inversion (CSI) method to reconstruct the dielectric profile of the head phantom.

  11. Shielding of Electronic Systems against Transient Electromagnetic Interferences

    Directory of Open Access Journals (Sweden)

    H. Herlemann

    2005-01-01

    Full Text Available In order to protect electronic systems against the effects of transient electromagnetic interferences, shields made of electrically conductive material can be used. The subject of this paper is an electrically conductive textile. When applying the shield, a reliable measure is needed in order to determine the effectiveness of the shield to protect against electromagnetic pulses. For this purpose, a time domain measurement technique is presented using double exponential pulses. With these pulses, the susceptibility of an operating electronic device with and without the shield is determined. As a criterion of quality of a shield, the breakdown failure rate found in both cases is compared.

  12. [Electromagnetic pollution (electrosmog)--potential hazards of our electromagnetic future].

    Science.gov (United States)

    Nowak, D; Radon, K

    2004-02-26

    The term electromagnetic environment encompasses the totality of all electric, magnetic and electromagnetic fields generated by natural and technical sources. A differentiation is made between low- and high-frequency electromagnetic fields. Typical sources of the former are domestic electricity Exposure to the latter is, for example, associated with the sue of mobile telephones. Studies on the health-related effects of electromagnetic fields are available in particular for the low-frequency range, based on an appropriate estimation of exposure. A number of these studies reveal an association between exposure to this type of electromagnetic fields and the occurrence of infantile leukemia in the highest exposure category. For high-frequency electromagnetic fields the number of epidemiological studies is limited. An increased risk of an accident occurring through the use of a cellular phone while driving has consistently been shown. Against the background of our limited knowledge about possible adverse effects of exposure to mobile phone transmitters, and the inability of the public to influence such exposure, transparency in the communication of the risks involved is of great importance.

  13. Gallilei covariant quantum mechanics in electromagnetic fields

    Directory of Open Access Journals (Sweden)

    H. E. Wilhelm

    1985-01-01

    Full Text Available A formulation of the quantum mechanics of charged particles in time-dependent electromagnetic fields is presented, in which both the Schroedinger equation and wave equations for the electromagnetic potentials are Galilei covariant, it is shown that the Galilean relativity principle leads to the introduction of the electromagnetic substratum in which the matter and electromagnetic waves propagate. The electromagnetic substratum effects are quantitatively significant for quantum mechanics in reference frames, in which the substratum velocity w is in magnitude comparable with the velocity of light c. The electromagnetic substratum velocity w occurs explicitly in the wave equations for the electromagnetic potentials but not in the Schroedinger equation.

  14. Head Injuries in Soccer.

    Science.gov (United States)

    Myrick, Karen M

    2016-07-01

    Soccer is currently the most popular and fastest growing sport worldwide, with approximately 265 million registered soccer players existing around the world. The popularity of the sport, coupled with the high incidence of 18.8-21.5 head injuries per 1,000 player hours reported, make it essential that clinicians, coaches, and the athletes, have a solid understanding of head injuries. The successful rehabilitation of athletes with head injuries relies upon early and accurate identification strategies and implementation of appropriate return to play measures across all areas in the continuum of care. Soccer is a frequently played sport, and head injuries are common. Therefore, it is imperative that clinicians, coaches, and the athletes themselves have a solid understanding of head injury prevention, diagnosis, and treatment options. The purpose of this article was to provide rehabilitation nurses with current information regarding frequently occurring head injuries in the widespread sport of soccer. © 2015 Association of Rehabilitation Nurses.

  15. Conical electromagnetic radiation flux concentrator

    Science.gov (United States)

    Miller, E. R.

    1972-01-01

    Concentrator provides method of concentrating a beam of electromagnetic radiation into a smaller beam, presenting a higher flux density. Smaller beam may be made larger by sending radiation through the device in the reverse direction.

  16. Earthquake prediction with electromagnetic phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Masashi, E-mail: hayakawa@hi-seismo-em.jp [Hayakawa Institute of Seismo Electomagnetics, Co. Ltd., University of Electro-Communications (UEC) Incubation Center, 1-5-1 Chofugaoka, Chofu Tokyo, 182-8585 (Japan); Advanced Wireless & Communications Research Center, UEC, Chofu Tokyo (Japan); Earthquake Analysis Laboratory, Information Systems Inc., 4-8-15, Minami-aoyama, Minato-ku, Tokyo, 107-0062 (Japan); Fuji Security Systems. Co. Ltd., Iwato-cho 1, Shinjyuku-ku, Tokyo (Japan)

    2016-02-01

    Short-term earthquake (EQ) prediction is defined as prospective prediction with the time scale of about one week, which is considered to be one of the most important and urgent topics for the human beings. If this short-term prediction is realized, casualty will be drastically reduced. Unlike the conventional seismic measurement, we proposed the use of electromagnetic phenomena as precursors to EQs in the prediction, and an extensive amount of progress has been achieved in the field of seismo-electromagnetics during the last two decades. This paper deals with the review on this short-term EQ prediction, including the impossibility myth of EQs prediction by seismometers, the reason why we are interested in electromagnetics, the history of seismo-electromagnetics, the ionospheric perturbation as the most promising candidate of EQ prediction, then the future of EQ predictology from two standpoints of a practical science and a pure science, and finally a brief summary.

  17. Monte Carlo methods for electromagnetics

    CERN Document Server

    Sadiku, Matthew NO

    2009-01-01

    Until now, novices had to painstakingly dig through the literature to discover how to use Monte Carlo techniques for solving electromagnetic problems. Written by one of the foremost researchers in the field, Monte Carlo Methods for Electromagnetics provides a solid understanding of these methods and their applications in electromagnetic computation. Including much of his own work, the author brings together essential information from several different publications.Using a simple, clear writing style, the author begins with a historical background and review of electromagnetic theory. After addressing probability and statistics, he introduces the finite difference method as well as the fixed and floating random walk Monte Carlo methods. The text then applies the Exodus method to Laplace's and Poisson's equations and presents Monte Carlo techniques for handing Neumann problems. It also deals with whole field computation using the Markov chain, applies Monte Carlo methods to time-varying diffusion problems, and ...

  18. Electromagnetic field theories for engineering

    CERN Document Server

    Salam, Md Abdus

    2014-01-01

    A four year Electrical and Electronic engineering curriculum normally contains two modules of electromagnetic field theories during the first two years. However, some curricula do not have enough slots to accommodate the two modules. This book, Electromagnetic Field Theories, is designed for Electrical and Electronic engineering undergraduate students to provide fundamental knowledge of electromagnetic fields and waves in a structured manner. A comprehensive fundamental knowledge of electric and magnetic fields is required to understand the working principles of generators, motors and transformers. This knowledge is also necessary to analyze transmission lines, substations, insulator flashover mechanism, transient phenomena, etc. Recently, academics and researches are working for sending electrical power to a remote area by designing a suitable antenna. In this case, the knowledge of electromagnetic fields is considered as important tool.

  19. Wave propagation in electromagnetic media

    CERN Document Server

    Davis, Julian L

    1990-01-01

    This is the second work of a set of two volumes on the phenomena of wave propagation in nonreacting and reacting media. The first, entitled Wave Propagation in Solids and Fluids (published by Springer-Verlag in 1988), deals with wave phenomena in nonreacting media (solids and fluids). This book is concerned with wave propagation in reacting media-specifically, in electro­ magnetic materials. Since these volumes were designed to be relatively self­ contained, we have taken the liberty of adapting some of the pertinent material, especially in the theory of hyperbolic partial differential equations (concerned with electromagnetic wave propagation), variational methods, and Hamilton-Jacobi theory, to the phenomena of electromagnetic waves. The purpose of this volume is similar to that of the first, except that here we are dealing with electromagnetic waves. We attempt to present a clear and systematic account of the mathematical methods of wave phenomena in electromagnetic materials that will be readily accessi...

  20. Head and Neck

    DEFF Research Database (Denmark)

    Højgaard, Liselotte; Berthelsen, Anne Kiil; Loft, Annika

    2014-01-01

    Positron emission tomography (PET)/computed tomography with FDG of the head and neck region is mainly used for the diagnosis of head and neck cancer, for staging, treatment evaluation, relapse, and planning of surgery and radio therapy. This article is a practical guide of imaging techniques......, including a detailed protocol for FDG PET in head and neck imaging, physiologic findings, and pitfalls in selected case stories....

  1. Radiation and propagation of electromagnetic waves

    CERN Document Server

    Tyras, George; Declaris, Nicholas

    1969-01-01

    Radiation and Propagation of Electromagnetic Waves serves as a text in electrical engineering or electrophysics. The book discusses the electromagnetic theory; plane electromagnetic waves in homogenous isotropic and anisotropic media; and plane electromagnetic waves in inhomogenous stratified media. The text also describes the spectral representation of elementary electromagnetic sources; the field of a dipole in a stratified medium; and radiation in anisotropic plasma. The properties and the procedures of Green's function method of solution, axial currents, as well as cylindrical boundaries a

  2. Probing the mechanism of saccade-associated head movements through observations of head movement propensity and cognition in the elderly.

    Science.gov (United States)

    Thumser, Zachary C; Adams, Nancy L; Lerner, Alan J; Stahl, John S

    2010-05-01

    Humans may accomplish gaze shifts by eye-only saccades or combined eye-head saccades. The mechanisms that determine whether the head moves remain poorly understood. Many observations can be explained if phylogenetically ancient circuits generate eye-head saccades by default and frontal cerebral structures interrupt this synergy when eye-only saccades are preferable. Saccade-associated head movements have been reported to increase in the elderly. To test the hypothesis of frontal inhibition of head movements, we investigated whether the increase is associated with a decline in frontal cognitive function. We measured head movement tendencies and cognition in volunteers aged 61-80. Measures of head movement tendency included the customary range of eye eccentricity, customary range of head eccentricity, range of target eccentricities evoking predominantly eye-only saccades, and two measures of head amplitude variation as a function of target eccentricity. Cognitive measures encompassed verbal fluency, verbal memory, non-verbal memory, and executive function. There was no correlation between cognition and any measure of head movement tendency. We combined these elderly data with measurements of head movements in a group aged 21-67 and found mildly reduced, not increased, head movement tendencies with age. However, when confronted with a task that could be accomplished without moving the head, young subjects were more likely to cease all head movements. While inconclusive regarding the hypothesis of inhibition of saccade-associated head movements by cerebral structures, the results indicate the need to distinguish between mechanisms that define head movement tendencies and mechanisms that adapt head motion to the geometry of a specific task.

  3. Head-to-toe whole-body MRI in psoriatic arthritis, axial spondyloarthritis and healthy subjects: first steps towards global inflammation and damage scores of peripheral and axial joints.

    Science.gov (United States)

    Poggenborg, René Panduro; Pedersen, Susanne Juhl; Eshed, Iris; Sørensen, Inge Juul; Møller, Jakob M; Madsen, Ole Rintek; Thomsen, Henrik S; Østergaard, Mikkel

    2015-06-01

    By whole-body MRI (WBMRI), we aimed to examine the frequency and distribution of inflammatory and structural lesions in PsA patients, SpA patients and healthy subjects (HSs), to introduce global WBMRI inflammation/damage scores, and to assess WBMRI's reproducibility and correlation with conventional MRI (convMRI). WBMRI (3.0-T) of patients with peripheral PsA (n = 18) or axial SpA (n = 18) and of HS (n = 12) was examined for proportion of evaluable features (readability) and the presence and pattern of lesions in axial and peripheral joints. Furthermore, global WBMRI scores of inflammation and structural damage were constructed, and WBMRI findings were compared with clinical measures and convMRI (SpA/HS: spine and SI joints; PsA/HS: hand). The readability (92-100%) and reproducibility (intrareader intraclass correlation coefficient: 0.62-1.0) were high in spine/SI joint, but lower in the distal peripheral joints. Wrists, shoulders, knees, ankles and MTP joints were most commonly involved, with frequency of synovitis > bone marrow oedema (BMO) > erosion. WBMRI global BMO scores of peripheral and axial joints were higher in PsA {median 7 [interquartile range (IQR) 3-15]} and SpA [8 (IQR 2-14)] than in HSs [2.5 (IQR 1-4.5)], both P joint scores were ρ = 0.20-0.78. WBMRI allows simultaneous assessment of peripheral and axial joints in PsA and SpA, and the distribution of inflammatory and structural lesions and global scores can be determined. The study strongly encourages further development and longitudinal testing of WBMRI techniques and assessment methods in PsA and SpA. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Advanced Model of Electromagnetic Launcher

    Directory of Open Access Journals (Sweden)

    Karel Leubner

    2015-01-01

    Full Text Available An advanced 2D model of electromagnetic launcher is presented respecting the influence of eddy currents induced in the accelerated ferromagnetic body. The time evolution of electromagnetic field in the system, corresponding forces acting on the projectile and time evolutions of its velocity and current in the field circuit are solved numerically using own application Agros2d. The results are then processed and evaluated in Wolfram Mathematica. The methodology is illustrated with an example whose results are discussed.

  5. Self-dual electromagnetic fields

    Science.gov (United States)

    Chubykalo, Andrew E.; Espinoza, Augusto; Kosyakov, B. P.

    2010-08-01

    We demonstrate the utility of self-dual fields in electrodynamics. Stable configurations of free electromagnetic fields can be represented as superpositions of standing waves, each possessing zero Poynting vector and zero orbital angular momentum. The standing waves are themselves superpositions of self-dual and anti-self-dual solutions. The idea of self-duality provides additional insights into the geometrical and spectral properties of stable electromagnetic configurations, such as those responsible for the formation of ball lightning.

  6. The law of electromagnetic force

    Directory of Open Access Journals (Sweden)

    V.J. Kutkovetskyy

    2014-06-01

    Full Text Available Calculation peculiarities for Lorentz force, Ampere force, interaction of parallel electric currents, and the moment of electrical machines are analyzed. They have exceptions on application, and they are the rules which result from the law of electromagnetic force as coordinate derivative of the operating magnetic flow. An addition to the direction of electromagnetic force action is proposed. Standards of salient-pole electrical machine designing are considered.

  7. Electromagnetic Interference in Implantable Rhythm Devices - The Indian Scenario

    Directory of Open Access Journals (Sweden)

    Johnson Francis

    2002-07-01

    Full Text Available Implantable rhythm device (IRD is the generic name for the group of implantable devices used for diagnosis and treatment of cardiac arrhythmias. Devices in this category include cardiac pacemakers, implantable cardioverter defibrillators and implantable loop recorders. Since these devices have complex microelectronic circuitry and use electromagnetic waves for communication, they are susceptible to interference from extraneous sources of electromagnetic radiation and magnetic energy. Electromagnetic interference (EMI is generally not a major problem outside of the hospital environment. The most important interactions occur when a patient is subjected to medical procedures such as magnetic resonance imaging (MRI, electrocautery and radiation therapy. Two articles in this issue of the journal discusses various aspects of EMI on IRD1,2 . Together these articles provide a good review of the various sources of EMI and their interaction with IRD for the treating physician.

  8. Electromagnetically induced grating in a crystal of molecular magnets system

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jibing, E-mail: liu0328@foxmail.com [College of Physics and Electronic Science and Institute for Advanced Materials, Hubei Normal University, Huangshi 435002 (China); Liu, Na; Shan, Chuanjia; Liu, Tangkun; Li, Hong [College of Physics and Electronic Science and Institute for Advanced Materials, Hubei Normal University, Huangshi 435002 (China); Zheng, Anshou, E-mail: zhengas-78@163.com [School of Mathematics and Physics, China University of Geosciences, Wuhan 430074 (China); Xie, Xiao-Tao, E-mail: xtxie1@gmail.com [School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710119 (China)

    2016-07-15

    We investigate the response of the molecular system to the magnetic field modulation. Molecular magnets are subjected to a strong standing ac magnetic field and a weak probe magnetic field. The transmission and absorption of the weak probe magnetic field can be changed due to quantum coherence and the spatially modulating of the standing field. And a electromagnetically induced grating is formed in the crystal of molecular magnets via electromagnetically induced transparency (EIT). The diffraction efficiency of the grating can be adjusted efficiently by tuning the intensity of the standing wave field and the single photon detuning. - Highlights: • We provide a scheme to generate electromagnetically induced grating in a crystal of molecular magnets. • The transmission and absorption of the probe magnetic field can be changed by the standing field. • The efficiency of diffraction is depended on the intensity of coupling and the single photon detuning.

  9. Active System for Electromagnetic Perturbation Monitoring in Vehicles

    Science.gov (United States)

    Matoi, Adrian Marian; Helerea, Elena

    Nowadays electromagnetic environment is rapidly expanding in frequency domain and wireless services extend in terms of covered area. European electromagnetic compatibility regulations refer to limit values regarding emissions, as well as procedures for determining susceptibility of the vehicle. Approval procedure for a series of cars is based on determining emissions/immunity level for a few vehicles picked randomly from the entire series, supposing that entire vehicle series is compliant. During immunity assessment, the vehicle is not subjected to real perturbation sources, but exposed to electric/magnetic fields generated by laboratory equipment. Since current approach takes into account only partially real situation regarding perturbation sources, this paper proposes an active system for determining electromagnetic parameters of vehicle's environment, that implements a logical diagram for measurement, satisfying the imposed requirements. This new and original solution is useful for EMC assessment of hybrid and electrical vehicles.

  10. Introduction to engineering electromagnetics

    CERN Document Server

    Lee, Yeon Ho

    2013-01-01

    This text provides students with the missing link that can help them master the basic principles of electromagnetics. The concept of vector fields is introduced by starting with clear definitions of position, distance, and base vectors. The symmetries of typical configurations are discussed in detail, including cylindrical, spherical, translational, and two-fold rotational symmetries. To avoid serious confusion between symbols with two indices, the text adopts a new notation: a letter with subscript 1-2 for the work done in moving a unit charge from point 2 to point 1, in which the subscript 1-2 mimics the difference in potentials, while the hyphen implies a sense of backward direction, from 2 to 1. This text includes 300 figures in which real data are drawn to scale. Many figures provide a three-dimensional view. Each subsection includes a number of examples that are solved by examining rigorous approaches in steps. Each subsection ends with straightforward exercises and answers through which students can c...

  11. ELECTROMAGNET CALORIMETER (ECAL)

    CERN Multimedia

    R. Rusack

    Installation is under way of the last piece of the electromagnetic calorimeter. This is the preshower (ES) that sits in front of the two endcap calorimeters. The construction of the ES was completed in December and went through a detailed set of tests in December and January. The two preshower detectors have a total of 4300 silicon sensors with 137,000 strips. After final assembly and system testing in January, only two of the strips were found to be defective. Once CMS was fully opened a new support structure (‘Gazprom’) was put into place underneath the beam pipe, to support the Surkov platform, on which the preshower installation takes place. In the early hours of 26th February the first two Dees, which form the ‘ES+’ endcap,  were transported to P5 , a journey that took two and a half hours. The Dees, still inside environmental protection boxes, were then lowered  underground and moved to the ‘+’ end of CMS. Installation start...

  12. Electromagnetism of Bacterial Growth

    Science.gov (United States)

    Ainiwaer, Ailiyasi

    2011-10-01

    There has been increasing concern from the public about personal health due to the significant rise in the daily use of electrical devices such as cell phones, radios, computers, GPS, video games and television. All of these devices create electromagnetic (EM) fields, which are simply magnetic and electric fields surrounding the appliances that simultaneously affect the human bio-system. Although these can affect the human system, obstacles can easily shield or weaken the electrical fields; however, magnetic fields cannot be weakened and can pass through walls, human bodies and most other objects. The present study was conducted to examine the possible effects of bacteria when exposed to magnetic fields. The results indicate that a strong causal relationship is not clear, since different magnetic fields affect the bacteria differently, with some causing an increase in bacterial cells, and others causing a decrease in the same cells. This phenomenon has yet to be explained, but the current study attempts to offer a mathematical explanation for this occurrence. The researchers added cultures to the magnetic fields to examine any effects to ion transportation. Researchers discovered ions such as potassium and sodium are affected by the magnetic field. A formula is presented in the analysis section to explain this effect.

  13. SOLAR NANTENNA ELECTROMAGNETIC COLLECTORS

    Energy Technology Data Exchange (ETDEWEB)

    Steven D. Novack; Dale K. Kotter; Dennis Slafer; Patrick Pinhero

    2008-08-01

    This research explores a new efficient approach for producing electricity from the abundant energy of the sun. A nanoantenna electromagnetic collector (NEC) has been designed, prototyped, and tested. Proof of concept has been validated. The device targets mid-infrared wavelengths where conventional photovoltaic (PV) solar cells do not respond but is abundant in solar energy. The initial concept of designing NEC antennas was based on scaling of radio frequency antenna theory. This approach has proven unsuccessful by many due to not fully understanding and accounting for the optical behavior of materials in the THz region. Also until recent years the nanofabrication methods were not available to fabricate the optical antenna elements. We have addressed and overcome both technology barriers. Several factors were critical in successful implementation of NEC including: 1) frequency-dependent modeling of antenna elements, 2) selection of materials with proper THz properties and 3) novel manufacturing methods that enable economical large-scale manufacturing. The work represents an important step toward the ultimate realization of a low-cost device that will collect as well as convert this radiation into electricity, which will lead to a wide spectrum, high conversion efficiency, and low cost solution to complement conventional PVs.

  14. Latency and distortion of electromagnetic trackers for augmented reality systems

    CERN Document Server

    Himberg, Henry

    2014-01-01

    Augmented reality (AR) systems are often used to superimpose virtual objects or information on a scene to improve situational awareness. Delays in the display system or inaccurate registration of objects destroy the sense of immersion a user experiences when using AR systems. AC electromagnetic trackers are ideal for these applications when combined with head orientation prediction to compensate for display system delays. Unfortunately, these trackers do not perform well in environments that contain conductive or ferrous materials due to magnetic field distortion without expensive calibration

  15. Electromagnetic semi-implantable hearing device: phase I. Clinical trials.

    Science.gov (United States)

    McGee, T M; Kartush, J M; Heide, J C; Bojrab, D I; Clemis, J D; Kulick, K C

    1991-04-01

    Conventional hearing aids have improved significantly in recent years; however, amplification of sound within the external auditory canal creates a number of intrinsic problems, including acoustic feedback and the need for a tight ear mold to increase usable gain. Nonacoustic alternatives which could obviate these encumbrances have not become practical due to inefficient coupling (piezoelectric techniques) or unfeasible power requirements (electromagnetic techniques). Recent technical advances, however, prompted a major clinical investigation of a new electromagnetic, semi-implantable hearing device. This study presents the details of clinical phase I, in which an electromagnetic driver was coupled with a target magnet temporarily affixed onto the lateral surface of the malleus of six hearing aid users with sensorineural losses. The results indicate that the electromagnetic hearing device provides sufficient gain and output characteristics to benefit individuals with sensorineural hearing loss. Significant improvements compared to conventional hearing aids were noted in pure-tone testing and, to a lesser degree, in speech discrimination. Subjective responses were quite favorable, indicating that the electromagnetic hearing device 1. produces no acoustic feedback; 2. works well in noisy environments; and 3. provides a more quiet, natural sound than patients' conventional hearing aids. These favorable results led to phase II of the project, in which patients with surgically amendable mixed hearing losses were implanted with the target magnet incorporated within a hydroxyapatite ossicular prosthesis. The results of this second-stage investigation were also encouraging and will be reported separately.

  16. Tinnitus and cell phones: the role of electromagnetic radiofrequency radiation

    Directory of Open Access Journals (Sweden)

    Luisa Nascimento Medeiros

    2016-02-01

    Full Text Available ABSTRACT INTRODUCTION: Tinnitus is a multifactorial condition and its prevalence has increased on the past decades. The worldwide progressive increase of the use of cell phones has exposed the peripheral auditory pathways to a higher dose of electromagnetic radiofrequency radiation (EMRFR. Some tinnitus patients report that the abusive use of mobiles, especially when repeated in the same ear, might worsen ipsilateral tinnitus. OBJECTIVE: The aim of this study was to evaluate the available evidence about the possible causal association between tinnitus and exposure to electromagnetic waves. METHODS: A literature review was performed searching for the following keywords: tinnitus, electromagnetic field, mobile phones, radio frequency, and electromagnetic hypersensitivity. We selected 165 articles that were considered clinically relevant in at least one of the subjects. RESULTS: EMRFR can penetrate exposed tissues and safety exposure levels have been established. These waves provoke proved thermogenic effects and potential biological and genotoxic effects. Some individuals are more sensitive to electromagnetic exposure (electrosensitivity, and thus, present earlier symptoms. There may be a common pathophysiology between this electrosensitivity and tinnitus. CONCLUSION: There are already reasonable evidences to suggest caution for using mobile phones to prevent auditory damage and the onset or worsening of tinnitus.

  17. Tinnitus and cell phones: the role of electromagnetic radiofrequency radiation.

    Science.gov (United States)

    Medeiros, Luisa Nascimento; Sanchez, Tanit Ganz

    2016-01-01

    Tinnitus is a multifactorial condition and its prevalence has increased on the past decades. The worldwide progressive increase of the use of cell phones has exposed the peripheral auditory pathways to a higher dose of electromagnetic radiofrequency radiation (EMRFR). Some tinnitus patients report that the abusive use of mobiles, especially when repeated in the same ear, might worsen ipsilateral tinnitus. The aim of this study was to evaluate the available evidence about the possible causal association between tinnitus and exposure to electromagnetic waves. A literature review was performed searching for the following keywords: tinnitus, electromagnetic field, mobile phones, radio frequency, and electromagnetic hypersensitivity. We selected 165 articles that were considered clinically relevant in at least one of the subjects. EMRFR can penetrate exposed tissues and safety exposure levels have been established. These waves provoke proved thermogenic effects and potential biological and genotoxic effects. Some individuals are more sensitive to electromagnetic exposure (electrosensitivity), and thus, present earlier symptoms. There may be a common pathophysiology between this electrosensitivity and tinnitus. There are already reasonable evidences to suggest caution for using mobile phones to prevent auditory damage and the onset or worsening of tinnitus. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  18. [Operational aspects of risk perception in the electromagnetic fields exposition].

    Science.gov (United States)

    Pennarola, E; Barletta, R; Quarto, E; Pennarola, R

    2007-01-01

    The increase of electromagnetic fields exposition is being associated with the increase of risk perception in the people exposed due to the uncertainty of the biological and sanitary effects. Research is being carried out on the symptomatology shown by the 45 people living near power-lines in the Benevento area and consequently exposed to electromagnetic fields. The measure of the magnetic and electric field was in the normal range while the people showed most symptoms in the subjective and behavioural sphere. The research findings suggest that risk assessement should take into account the subjectivity of the people exposed as shown in the special questionnaires with the aim of reducing the subjective and behavioural symptomatology for developing a new environmental medicine.

  19. Occupational exposure to electromagnetic fields in the Polish Armed Forces

    Directory of Open Access Journals (Sweden)

    Jarosław Kieliszek

    2017-08-01

    Full Text Available Objectives: Standard devices used by military personnel that may pose electromagnetic hazard include: radars, missile systems, radio navigation systems and radio transceivers. The aim of this study has been to evaluate the exposure of military personnel to electromagnetic fields. Material and Methods: Occupational exposure to electromagnetic fields was analyzed in the work environment of personnel of 204 devices divided into 5 groups (surface-to-air missile system radars, aircraft and helicopters, communication devices, surveillance and height finder radars, airport radars and radio navigation systems. Measurements were carried out at indicators, device terminals, radio panels, above vehicle seats, in vehicle hatches, by cabinets containing high power vacuum tubes and other transmitter components, by transmission lines, connectors, etc. Results: Portable radios emit the electric field strength between 20–80 V/m close to a human head. The manpack radio operator’s exposure is 60–120 V/m. Inside vehicles with high frequency/very high frequency (HF/VHF band radios, the electric field strength is between 7–30 V/m and inside the radar cabin it ranges between 9–20 V/m. Most of the personnel on ships are not exposed to the electromagnetic field from their own radar systems but rather by accidental exposure from the radar systems of other ships. Operators of surface-to-air missile systems are exposed to the electric field strength between 7–15 V/m and the personnel of non-directional radio beacons – 100–150 V/m. Conclusions: In 57% of military devices Polish soldiers work in the occupational protection zones. In 35% of cases, soldiers work in intermediate and hazardous zones and in 22% – only in the intermediate zone. In 43% of devices, military personnel are not exposed to electromagnetic field. Int J Occup Med Environ Health 2017;30(4:565–577

  20. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Computed tomography (CT) of the head uses special x-ray equipment to help assess head injuries, severe headaches, ... is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside ...

  1. Head Injuries in Children

    Science.gov (United States)

    Pennington, Nicole

    2010-01-01

    School nurses play a crucial role in injury prevention and initial treatment when injuries occur at school. The role of school nurses includes being knowledgeable about the management of head injuries, including assessment and initial treatment. The school nurse must be familiar with the outcomes of a head injury and know when further evaluation…

  2. Abnormal Head Position

    Science.gov (United States)

    ... non-ocular causes of an abnormal head position? Congenital shortening of the neck muscles (sternocleidomastoid) can cause a head tilt. This is ... amblyopia) are other treatment alternatives. Physical therapy helps congenital torticollis from tight neck muscles. Updated ... Terms & Conditions Most Common ...

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... the limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside of ...

  4. Head Start in Action.

    Science.gov (United States)

    Riley, Clara M. D.; Epps, Frances M. J.

    Records and observations from a summer Head Start program, conducted in Los Angeles by Delta Sigma Theta, are delineated in this book. It relates firsthand experiences of the participating personnel as they developed and implemented a Head Start program for some 300 children. The book is divided into three sections. Section I,…

  5. THE GENERATION OF THERMOELASTIC STRESS WAVES BY IMPULSIVE ELECTROMAGNETIC RADIATION.

    Science.gov (United States)

    ELECTROMAGNETIC RADIATION , ABSORPTION), (*STRESSES, ELECTROMAGNETIC RADIATION ), SURFACE PROPERTIES, INTERACTIONS, HEAT TRANSFER, ELASTIC PROPERTIES, ELECTROMAGNETIC PULSES, LASERS, MATHEMATICAL ANALYSIS, BOUNDARY VALUE PROBLEMS, SOLIDS

  6. Porcine head response to blast.

    Science.gov (United States)

    Shridharani, Jay K; Wood, Garrett W; Panzer, Matthew B; Capehart, Bruce P; Nyein, Michelle K; Radovitzky, Raul A; Bass, Cameron R 'dale'

    2012-01-01

    Recent studies have shown an increase in the frequency of traumatic brain injuries related to blast exposure. However, the mechanisms that cause blast neurotrauma are unknown. Blast neurotrauma research using computational models has been one method to elucidate that response of the brain in blast, and to identify possible mechanical correlates of injury. However, model validation against experimental data is required to ensure that the model output is representative of in vivo biomechanical response. This study exposes porcine subjects to primary blast overpressures generated using a compressed-gas shock tube. Shock tube blasts were directed to the unprotected head of each animal while the lungs and thorax were protected using ballistic protective vests similar to those employed in theater. The test conditions ranged from 110 to 740 kPa peak incident overpressure with scaled durations from 1.3 to 6.9 ms and correspond approximately with a 50% injury risk for brain bleeding and apnea in a ferret model scaled to porcine exposure. Instrumentation was placed on the porcine head to measure bulk acceleration, pressure at the surface of the head, and pressure inside the cranial cavity. Immediately after the blast, 5 of the 20 animals tested were apneic. Three subjects recovered without intervention within 30 s and the remaining two recovered within 8 min following respiratory assistance and administration of the respiratory stimulant doxapram. Gross examination of the brain revealed no indication of bleeding. Intracranial pressures ranged from 80 to 390 kPa as a result of the blast and were notably lower than the shock tube reflected pressures of 300-2830 kPa, indicating pressure attenuation by the skull up to a factor of 8.4. Peak head accelerations were measured from 385 to 3845 G's and were well correlated with peak incident overpressure (R(2) = 0.90). One SD corridors for the surface pressure, intracranial pressure (ICP), and head acceleration are

  7. SUBJECT INDEX

    Indian Academy of Sciences (India)

    Subject Index. Variation of surface electric field during geomagnetic disturbed period at Maitri, Antarctica. 1721. Geomorphology. A simple depression-filling method for raster and irregular elevation datasets. 1653. Decision Support System integrated with Geographic. Information System to target restoration actions in water-.

  8. On the subject-predicate relation and subject agreement in SiSwati ...

    African Journals Online (AJOL)

    The paper also argues that subject agreement is a purely syntactic phenomenon that takes place in a spec-head relationship. It proposes that subject agreement is triggered by verbs, and that multiple subject agreement within a clause occurs when auxiliary verbs iterate. The theoretical consequences of the analysis ...

  9. International Symposium on Electromagnetic Compatibility, 25th, Arlington, VA, August 23-25, 1983, Symposium Record

    Science.gov (United States)

    Subjects related to electromagnetic compatibility (EMC) analysis are discussed, taking into account forcing terms of line equations for externally excited transmission lines, E-fields over ground, electromagnetic near fields as a function of electrical size, a program for experimental verification of EMC analysis models, random susceptability of an IC 7400 TTL NAND gate, and a comparison of IEMCAP and SEMCAP. Other topics explored are concerned with EMC measurements, spectrum management, the electromagnetic pulse (EMP), a Navy EMC program, measurement systems, filters, EMC design, electromagnetic vulnerability (EMV) assessment of weapon systems, FCC rules and regulations, shielding, and electromagnetic interference (EMI) in communication systems. Attention is also given to nonsinusoidal functions in radar and communications, transients/electrostatic discharge, open field testing, cables and connectors, interference effects of induced and conducted earth current at dc and ELF, test cells, and cable coupling.

  10. Driving with head-slaved camera system

    NARCIS (Netherlands)

    Oving, A.B.; Erp, J.B.F. van

    2001-01-01

    In a field experiment, we tested the effectiveness of a head-slaved camera system for driving an armoured vehicle under armour. This system consists of a helmet-mounted display (HMD), a headtracker, and a motion platform with two cameras. Subjects performed several driving tasks on paved and in

  11. Electromagnetic aquametry electromagnetic wave interaction with water and moist substances

    CERN Document Server

    Kupfer, Klaus

    2006-01-01

    This book covers all aspects of Electromagnetic Aquametry. It summarizes the wide area of metrology and its applications in electromagnetic sensing of moist materials. The physical properties of water in various degrees of binding interacting with electromagnetic fields is presented by model systems. The book describes measurement methods and sensors in the frequency domain, TDR-techniques for environmental problems, methods and sensors for quality assessment of biological substances, and nuclear magnetic resonance techniques. Environmental sciences, as well as civil and geoengineering, fossil fuels, food and pharmaceutical science are the main fields of application. A very wide frequency sprectrum is used for dielectric measurement methods, but the microwave range is clearly dominant. Multiparameter methods as well as methods of principal components and artificial neural networks for density independent measurements are described.

  12. 1 CFR 21.19 - Composition of part headings.

    Science.gov (United States)

    2010-01-01

    ... 1 General Provisions 1 2010-01-01 2010-01-01 false Composition of part headings. 21.19 Section 21.19 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER PREPARATION, TRANSMITTAL, AND PROCESSING OF DOCUMENTS PREPARATION OF DOCUMENTS SUBJECT TO CODIFICATION General Headings § 21.19 Composition...

  13. Learning people's names following severe closed-head injury

    NARCIS (Netherlands)

    Milders, M.V.

    Although problems remembering people's names rank highly among the subjective complaints of patients with closed-head injuries, very few studies have examined their memory for people's names by objective measurements. An experiment is reported in which patients with severe closed-head injuries and

  14. Parental determinants of offspring head circumference using a ...

    African Journals Online (AJOL)

    The baby's head circumference was measured immediately after birth. The data were subjected to multivariate analysis. Results: The parental variables that were most predictive of babies' head circumference were mid-parental weight, maternal height, maternal weight gain during pregnancy and maternal age. Conclusion: ...

  15. Baseline head in Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Ahokas, H.; Tammisto, E.; Lehtimaeki, T. (Poeyry Environment Oy, Vantaa (Finland))

    2008-11-15

    As part of the programme for the final disposal of the spent nuclear fuel, Posiva Oy investigates the prevailing hydrological conditions on Olkiluoto island. The hydrological investigations have included several kinds of hydrological tests such as measurements of hydraulic conductivity by flow logging and a double-packer tool as well as interference tests by pumping, in order to study the hydraulic connections between the drillholes. In addition, long-term monitoring of groundwater level and groundwater head as well as measurements of flow conditions in open drillholes, groundwater salinity (in situ EC), precipitation (including snow), sea-water level, surface flow (runoff) etc. have been part of the investigation programme aiming at the characterization of the bedrock. The data have been used in the compilation of deterministic hydro-zones and hydraulic properties for numerical flow modelling to study the flow pattern on Olkiluoto island. In addition, the compiled bedrock models have been used in the planning of the repository layout and in the analyses of the transport of radionuclides and the functionality of engineered barriers. This report focuses on the measurements of groundwater head by means of multi-packers and in connection with flow loggings. The determination of the undisturbed groundwater head (baseline head) in terms of the in situ fresh water head is the main goal of this report. The density of groundwater is strongly dependent on salinity and due to the saline groundwater deep in the bedrock in Olkiluoto the term fresh water head is used instead of hydraulic head. Taking the density of groundwater into account, the gradient of the residual pressure, which actually causes groundwater flow can be calculated. The measured and calculated heads are converted into corresponding in situ fresh water heads, which correspond to the water level (metres above sea level) in the hose that runs from the packed-off section to the ground surface. This means that

  16. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... the limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive ... top of page What are some common uses of the procedure? MR imaging of the head is ...

  17. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive ... of page What are some common uses of the procedure? MR imaging of the head is performed ...

  18. Ulnar head replacement.

    Science.gov (United States)

    Herbert, Timothy J; van Schoonhoven, Joerg

    2007-03-01

    Recent years have seen an increasing awareness of the anatomical and biomechanical significance of the distal radioulnar joint (DRUJ). With this has come a more critical approach to surgical management of DRUJ disorders and a realization that all forms of "excision arthroplasty" can only restore forearm rotation at the expense of forearm stability. This, in turn, has led to renewed interest in prosthetic replacement of the ulnar head, a procedure that had previously fallen into disrepute because of material failures with early implants, in particular, the Swanson silicone ulnar head replacement. In response to these early failures, a new prosthesis was developed in the early 1990s, using materials designed to withstand the loads across the DRUJ associated with normal functional use of the upper limb. Released onto the market in 1995 (Herbert ulnar head prosthesis), clinical experience during the last 10 years has shown that this prosthesis is able to restore forearm function after ulnar head excision and that the materials (ceramic head and noncemented titanium stem), even with normal use of the limb, are showing no signs of failure in the medium to long term. As experience with the use of an ulnar head prosthesis grows, so does its acceptance as a viable and attractive alternative to more traditional operations, such as the Darrach and Sauve-Kapandji procedures. This article discusses the current indications and contraindications for ulnar head replacement and details the surgical procedure, rehabilitation, and likely outcomes.

  19. Electromagnetic compatibility and interference metrology

    Science.gov (United States)

    Ma, M. T.; Kanda, M.

    1986-07-01

    The material included in the report is intended for a short course on electromagnetic compatibility/interference (EMC/EM) metrology. The entire course is presented in nine chapters with the introductory part given as Chapter 1. The particular measurement topics to be covered are: (1) open sites (Chapters 2 and 6), (2) transverse electromagnetic cells (Chapter 3), (3) techniques for measuring the electromagnetic shielding of materials (Chapter 4), (4) anechoic chambers (Chapter 5), and (5) reverberating chambers (Chapter 8). In addition, since small probe antennas play an important role in some of the EMC/EMI measurements discussed, a separate chapter on various probe systems developed at NBS is given in Chapter 7. Selected contemporary EMI topics such as the characterization and measurement of a complex EM environment, interferences in the form of out-of-band receptions to an antenna, and some conducted EMI problems are also briefly discussed (Chapter 9).

  20. Electromagnetic fields in biological systems

    CERN Document Server

    Lin, James C

    2016-01-01

    As wireless technology becomes more sophisticated and accessible to more users, the interactions of electromagnetic fields with biological systems have captured the interest not only of the scientific community but also the general public. Unintended or deleterious biological effects of electromagnetic fields and radiation may indicate grounds for health and safety precautions in their use. Spanning static fields to terahertz waves, Electromagnetic Fields in Biological Systems explores the range of consequences these fields have on the human body. With contributions by an array of experts, topics discussed include: Essential interactions and field coupling phenomena, highlighting their importance in research on biological effects and in scientific, industrial, and medical applications Electric field interactions in cells, focusing on ultrashort, pulsed high-intensity fields The effect of exposure to naturally occurring and human-made static, low-frequency, and pulsed magnetic fields in biological systems Dosi...

  1. Electromagnetic Transients in Power Cables

    DEFF Research Database (Denmark)

    Silva, Filipe Faria Da; Bak, Claus Leth

    of electromagnetic phenomena associated to their operation, among them electromagnetic transients, increased as well. Transient phenomena have been studied since the beginning of power systems, at first using only analytical approaches, which limited studies to more basic phenomena; but as computational tools became...... more powerful, the analyses started to expand for the more complex phenomena. Being old phenomena, electromagnetic transients are covered in many publications, and classic books such as the 40-year-old Greenwood’s ‘‘Electric Transients in Power Systems’’ are still used to this day. However...... example.However, the book is not only intended for students . It can also be used by engineers who work in this area and need to understand the challenges/problems they are facing or who need to learn how to prepare their simulation models as well as their function. It also shows how to calculate...

  2. Objects of maximum electromagnetic chirality

    CERN Document Server

    Fernandez-Corbaton, Ivan

    2015-01-01

    We introduce a definition of the electromagnetic chirality of an object and show that it has an upper bound. The upper bound is attained if and only if the object is transparent for fields of one handedness (helicity). Additionally, electromagnetic duality symmetry, i.e. helicity preservation upon scattering, turns out to be a necessary condition for reciprocal scatterers to attain the upper bound. We use these results to provide requirements for the design of such extremal scatterers. The requirements can be formulated as constraints on the polarizability tensors for dipolar scatterers or as material constitutive relations. We also outline two applications for objects of maximum electromagnetic chirality: A twofold resonantly enhanced and background free circular dichroism measurement setup, and angle independent helicity filtering glasses.

  3. Electromagnetic contributions to pseudoscalar masses

    CERN Document Server

    Basak, S; Bernard, C; DeTar, C; Freeland, E; Freeman, W; Foley, J; Gottlieb, Steven; Heller, U M; Hetrick, J E; Laiho, J; Levkova, L; Oktay, M; Osborn, J; Sugar, R L; Torok, A; Toussaint, D; Van de Water, R S; Zhou, R

    2013-01-01

    We report on the calculation by the MILC Collaboration of the electromagnetic effects on kaon and pion masses. These masses are computed in QCD with dynamical (asqtad staggered) quarks plus quenched photons at three lattice spacings varying from 0.12 to 0.06 fm. The masses are fit to staggered chiral perturbation theory with NLO electromagnetic terms, as well as analytic terms at higher order. We extrapolate the results to physical light-quark masses and to the continuum limit. At the current stage of the analysis, most, but not all, of the systematic errors have been estimated. The main goal is the comparison of kaon electromagnetic splittings to those of the pion, i.e., an evaluation of the corrections to "Dashen's theorem." This in turn will allow us to significantly reduce the systematic errors in our determination of m_u/m_d.

  4. Moving Manifolds in Electromagnetic Fields

    Directory of Open Access Journals (Sweden)

    David V. Svintradze

    2017-08-01

    Full Text Available We propose dynamic non-linear equations for moving surfaces in an electromagnetic field. The field is induced by a material body with a boundary of the surface. Correspondingly the potential energy, set by the field at the boundary can be written as an addition of four-potential times four-current to a contraction of the electromagnetic tensor. Proper application of the minimal action principle to the system Lagrangian yields dynamic non-linear equations for moving three dimensional manifolds in electromagnetic fields. The equations in different conditions simplify to Maxwell equations for massless three surfaces, to Euler equations for a dynamic fluid, to magneto-hydrodynamic equations and to the Poisson-Boltzmann equation.

  5. CIME School on "Computational Electromagnetism"

    CERN Document Server

    Valli, Alberto

    2015-01-01

    Presenting topics that have not previously been contained in a single volume, this book offers an up-to-date review of computational methods in electromagnetism, with a focus on recent results in the numerical simulation of real-life electromagnetic problems and on theoretical results that are useful in devising and analyzing approximation algorithms. Based on four courses delivered in Cetraro in June 2014, the material covered includes the spatial discretization of Maxwell’s equations in a bounded domain, the numerical approximation of the eddy current model in harmonic regime, the time domain integral equation method (with an emphasis on the electric-field integral equation) and an overview of qualitative methods for inverse electromagnetic scattering problems. Assuming some knowledge of the variational formulation of PDEs and of finite element/boundary element methods, the book is suitable for PhD students and researchers interested in numerical approximation of partial differential equations and scienti...

  6. Subject-verb number (disagreement

    Directory of Open Access Journals (Sweden)

    Daniela Isac

    2010-01-01

    Full Text Available This paper discusses cases of number mismatches between subjects and verbs. The main proposal is that subject-verb agreement is not in number but in a different feature, that we call Cardinality. Cardinality is a feature of DPs that is computed on the basis of number features and collectivity features carried by various heads in the DP. The “computation” of the Cardinality feature proceeds internal to the feature matrix of one lexical item - the D. The values of the number and collectivity features carried by various heads in the DP are transferred to the D by means of a feature checking mechanism and the value of the Cardinality feature is then derived from these.

  7. The Subject Headings of the Morris Swett Library, USAFAS. Revised.

    Science.gov (United States)

    1980-05-15

    Sparrow) S7 (Sparrow I) S71 (Sparrow II) S72 (Sparrow III) S73 ( Sprint ) S78 (Talos-W) T2 (Terrier) T3 (Terrier iB) T31 (TOW) (Typhoon) T9 (XSSM-A-1... VOLLEYBALL (GV 1017) VOLTAGE DIVIDERS VOLTOHMETER (TK 7879.2) VOLTURNO, BATTLE OF THE, 1943 (D 763.161 V7) VOLUNTEERS, MILITARY (UB 323) VOODOOISM

  8. Circuit modeling for electromagnetic compatibility

    CERN Document Server

    Darney, Ian B

    2013-01-01

    Very simply, electromagnetic interference (EMI) costs money, reduces profits, and generally wreaks havoc for circuit designers in all industries. This book shows how the analytic tools of circuit theory can be used to simulate the coupling of interference into, and out of, any signal link in the system being reviewed. The technique is simple, systematic and accurate. It enables the design of any equipment to be tailored to meet EMC requirements. Every electronic system consists of a number of functional modules interconnected by signal links and power supply lines. Electromagnetic interference

  9. Electromagnetic compatibility principles and applications

    CERN Document Server

    Weston, David A

    2001-01-01

    This totally revised and expanded reference/text provides comprehensive, single-source coverage of the design, problem solving, and specifications of electromagnetic compatibility (EMC) into electrical equipment/systems-including new information on basic theories, applications, evaluations, prediction techniques, and practical diagnostic options for preventing EMI through cost-effective solutions. Offers the most recent guidelines, safety limits, and standards for human exposure to electromagnetic fields! Containing updated data on EMI diagnostic verification measurements, as well as over 900 drawings, photographs, tables, and equations-500 more than the previous edition

  10. Mathematical methods of electromagnetic theory

    CERN Document Server

    Friedrichs, Kurt O

    2014-01-01

    This text provides a mathematically precise but intuitive introduction to classical electromagnetic theory and wave propagation, with a brief introduction to special relativity. While written in a distinctive, modern style, Friedrichs manages to convey the physical intuition and 19th century basis of the equations, with an emphasis on conservation laws. Particularly striking features of the book include: (a) a mathematically rigorous derivation of the interaction of electromagnetic waves with matter, (b) a straightforward explanation of how to use variational principles to solve problems in el

  11. Electromagnetic geothermometry theory, modeling, practice

    CERN Document Server

    Spichak, Viacheslav V

    2015-01-01

    Electromagnetic Geothermometry explores, presents and explains the new technique of temperature estimation within the Earth's interior; the Electromagnetic technique will identify zones of geothermal anomalies and thus provides locations for deep drilling. This book includes many case studies from geothermal areas such as Travale (Italy), Soultz-sous-Forêts (France) and Hengill (Iceland), allowing the author and reader to draw conclusions regarding the dominating heat transfer mechanisms, location of its sources and to constrain the locations for drilling of the new boreholes. Covering a to

  12. Integral equation methods for electromagnetics

    CERN Document Server

    Volakis, John

    2012-01-01

    This text/reference is a detailed look at the development and use of integral equation methods for electromagnetic analysis, specifically for antennas and radar scattering. Developers and practitioners will appreciate the broad-based approach to understanding and utilizing integral equation methods and the unique coverage of historical developments that led to the current state-of-the-art. In contrast to existing books, Integral Equation Methods for Electromagnetics lays the groundwork in the initial chapters so students and basic users can solve simple problems and work their way up to the mo

  13. Measurement of advanced electromagnetic radiation

    OpenAIRE

    Bajlo, Darko

    2017-01-01

    For the purpose of detecting advanced electromagnetic radiation predicted by Wheeler-Feynman absorber theory for the case of incomplete absorption of retarded electromagnetic radiation, pulses in duration of 6 ns to 24 ns, wavelength from 91 cm to 200 cm where supplied to three different transmitting antennas. Detection was done with a λ/20 monopole antenna in the advanced time window at a time 2r/c before the arrival of the center of the retarded pulse. At distances ranging from 430 cm to 18...

  14. A Complex of the Electromagnetic Biosensors with a Nanowired Pickup

    Directory of Open Access Journals (Sweden)

    Rostyslav Sklyar

    2009-01-01

    Full Text Available The proposal to measure the biosignal values of different origins with advanced nanosensors of electromagnetic quantities is justified when allowing for superconducting abilities of the devices. They are composed in full-scale arrays. The said arrays can be both implantable into ionic channels of an organism and sheathed on the sources of the electromagnetic emanation. Nanowired head sensors function both in passive mode for picking up the biosignals and with additional excitation of a defined biomedium through the same head (in reverse. The designed variety of bio-nanosensors allow interfacing a variety of biosignals with the external systems, also with a possibility to control the exposure on an organism by artificially created signals. The calculated signals lies in the range of −5 to 5 V, (7÷0⋅1017/cm3 molecules or magnetic beads, 2÷10 pH, and stream speed 3⋅10−3÷102 m/s, flow 10−5÷10 m/s, and haemoglobin concentration of 1030÷1024 molec/cm3. The sensitivity of this micro- or nanoscope can be estimated as =10−4 (A⋅m/√Hz with SNR equal to 104. The sensitivity of an advanced first-order biogradiometer is equal to 3 fT/√Hz. The smallest resolvable change in magnetic moment detected by this system in the band 10 Hz is 1 fJ/T.

  15. Parametric Instabilities of Electromagnetic Waves in Plasmas,

    Science.gov (United States)

    A simple formalism for the parametric decay of an intense, coherent electromagnetic wave into an electrostatic wave and scattered electromagnetic ... waves in a homogeneous plasma is developed. Various instabilities including Brillouin and Raman backscattering, Compton scattering, filamentation and

  16. Higher-order techniques in computational electromagnetics

    CERN Document Server

    Graglia, Roberto D

    2016-01-01

    Higher-Order Techniques in Computational Electromagnetics explains 'high-order' techniques that can significantly improve the accuracy, computational cost, and reliability of computational techniques for high-frequency electromagnetics, such as antennas, microwave devices and radar scattering applications.

  17. Electromagnetic Compatibility of Devices on Hybrid Electromagnetic Components

    Science.gov (United States)

    Konesev, S. G.; Khazieva, R. T.; Kirillov, R. V.; Gainutdinov, I. Z.; Kondratyev, E. Y.

    2018-01-01

    There is a general tendency to reduce the weight and dimensions, the consumption of conductive and electrical insulating materials, increase the reliability and energy efficiency of electrical devices. In recent years, designers have been actively developing devices based on hybrid electromagnetic components (HEMC) such as inductive-capacitive converters (ICC), voltages pulse generators (VPG), secondary power supplies (SPS), capacitive storage devices (CSD), induction heating systems (IHS). Sources of power supplies of similar electrical devices contain, as a rule, links of increased frequency and function in key (pulse) modes, which leads to an increase in electromagnetic interference (EMI). Nonlinear and periodic (impulse) loads, non-sinusoidal (pulsation) of the electromotive force and nonlinearity of the internal parameters of the source and input circuits of consumers distort the shape of the input voltage lead to an increase in thermal losses from the higher harmonic currents, aging of the insulation, increase in the weight of the power supply filter units, resonance at higher harmonics. The most important task is to analyze the operation of electrotechnical devices based on HEMC from the point of view of creating EMIs and assessing their electromagnetic compatibility (EMC) with power supply systems (PSS). The article presents the results of research on the operation of an IHS, the operation principle of a secondary power supply source of which is based on the operation of a half-bridge autonomous inverter, the switching circuit of which is made in the form of a HEMC, called the «multifunctional integrated electromagnetic component»" (MIEC).

  18. Bathymetry, electromagnetic streamlines and the marine controlled source electromagnetic method

    Science.gov (United States)

    Pethick, Andrew; Harris, Brett

    2014-07-01

    Seafloor topography must influence the strength and direction of electromagnetic fields generated during deep ocean controlled source electromagnetic surveying. Neither mathematical equation nor rules of thumb provide a clear perspective of how changes in water column thickness alters electromagnetic fields that engulf hundreds of cubic kilometres of air, ocean, host and reservoir. We use streamline visualisation to provide a generalised representation of how electromagnetic fields propagate into a 2D geo-electrical setting that includes strong bathymetry. Of particular interest are: (i)' dead zones' where electric fields at the ocean floor are demonstrated to be weak and (ii) the 'airwave' that appears in the electric field streamlines as circulating vortices with a shape that is clearly influenced by changes in ocean depth. Our analysis of the distribution of electric fields for deep and shallow water examples alludes to potential benefits from placement of receivers and/or transmitters higher in the water column as is the case for towed receiver geometries. Real-time streamline representation probably holds the most value at the survey planning stage, especially for shallow water marine EM surveys where ocean bottom topography is likely to be consequential.

  19. Ultrastructural Study on Ultra-Low Frequency Electromagnetic Fields and Transfer Factor Effects on Skin Ulcers

    Science.gov (United States)

    Cadena, M. S. Reyes; Chapul, L. Sánchez; Pérez, Javiér; García, M. N. Jiménez; López, M. A. Jiménez; Espíndola, M. E. Sánchez; Perez, R. Paniagua; Hernández, N. A.; Paniagua, G.; Uribe, F.; Nava, J. J. Godina; Segura, M. A. Rodríguez

    2008-08-01

    We determined the effect of 120Hz ultra low frequency electromagnetic field (ELF) on the healing process of skin in 20 Wistar rats distributed in four groups in which chronic dermal ulcers had been produced. The first two groups received a dose of the transfer factor and interferon-beta (IFN-β) every 24 h during 12 days. The third group (positive control) received only electromagnetic field (ELF) sessions, and in the fourth group (negative control), no treatment was applied. The electromagnetic field was applied through a Helmholtz coils; 30 Gauss of intensity. Results shown histological changes that improve the healing process in animals subjected to ELF together with the transfer factor.

  20. Phase-space representation and polarization domains of random electromagnetic fields.

    Science.gov (United States)

    Castaneda, Roman; Betancur, Rafael; Herrera, Jorge; Carrasquilla, Juan

    2008-08-01

    The phase-space representation of stationary random electromagnetic fields is developed by using electromagnetic spatial coherence wavelets. The propagation of the field's power and states of spatial coherence and polarization results from correlations between the components of the field vectors at pairs of points in space. Polarization domains are theoretically predicted as the structure of the field polarization at the observation plane. In addition, the phase-space representation provides a generalization of the Poynting theorem. Theoretical predictions are examined by numerically simulating the Young experiment with electromagnetic waves. The experimental implementation of these results is a current subject of research.

  1. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... you! Do you have a personal story about radiology? Share your patient story here Images × Image Gallery ... Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to ...

  2. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear ... or other physician. To locate a medical imaging or radiation oncology provider in your community, you can search the ...

  3. Overview of Head Injuries

    Science.gov (United States)

    ... brain. If the head injury is very severe, mechanical ventilation may be used. Doctors control blood pressure and minimize the amount of brain swelling by adjusting the amount of intravenous fluids given and sometimes by giving intravenous drugs that ...

  4. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... headaches, dizziness, and other symptoms of aneurysm, bleeding, stroke and brain tumors. It also helps your doctor ... scanning provides more detailed information on head injuries, stroke , brain tumors and other brain diseases than regular ...

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... be necessary. Your doctor will explain the exact reason why another exam is requested. Sometimes a follow- ... limitations of CT Scanning of the Head? A person who is very large may not fit into ...

  6. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... medically necessary because of potential risk to the baby. This risk is, however, minimal with head CT ... intravenous contrast indicate mothers should not breastfeed their babies for 24-48 hours after contrast medium is ...

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... assess head injuries, severe headaches, dizziness, and other symptoms of aneurysm, bleeding, stroke and brain tumors. It ... within the brain shortly after a patient exhibits symptoms of a stroke. a stroke, especially with a ...

  8. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... scans in children should always be done with low-dose technique. top of page What are the ... page Additional Information and Resources RTAnswers.org Radiation Therapy for Brain Tumors Radiation Therapy for Head and ...

  9. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... this tunnel. Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite ... medically necessary because of potential risk to the baby. This risk is, however, minimal with head CT ...

  10. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... head CT scanning. Manufacturers of intravenous contrast indicate mothers should not breastfeed their babies for 24-48 ...

  11. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... special x-ray equipment to help assess head injuries, severe headaches, dizziness, and other symptoms of aneurysm, ... cancer. In emergency cases, it can reveal internal injuries and bleeding quickly enough to help save lives. ...

  12. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... traditional x-rays, particularly of soft tissues and blood vessels. CT scanning provides more detailed information on head injuries, stroke , brain tumors and other brain diseases than regular radiographs (x-rays). top of page ...

  13. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... used to detect: bleeding, brain injury and skull fractures in patients with head injuries. bleeding caused by ... a few seconds, and even faster in small children. Such speed is beneficial for all patients but ...

  14. TCGA head Neck

    Science.gov (United States)

    Investigators with The Cancer Genome Atlas (TCGA) Research Network have discovered genomic differences – with potentially important clinical implications – in head and neck cancers caused by infection with the human papillomavirus (HPV).

  15. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... microphone. top of page How does the procedure work? In many ways CT scanning works very much ... for Head and Neck Cancer Others American Stroke Association National Stroke Association top of page This page ...

  16. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... images of internal organs, bones, soft tissue and blood vessels provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. CT scanning provides more detailed information on head ...

  17. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... sometimes compared to looking into a loaf of bread by cutting the loaf into thin slices. When ... for Brain Tumors Radiation Therapy for Head and Neck Cancer Others American Stroke Association National Stroke Association ...

  18. Early Head Start Evaluation

    Data.gov (United States)

    U.S. Department of Health & Human Services — Longitudinal information from an evaluation where children were randomly assigned to Early Head Start or community services as usual;direct assessments and...

  19. Head Start Impact Study

    Data.gov (United States)

    U.S. Department of Health & Human Services — Nationally representative, longitudinal information from an evaluation where children were randomly assigned to Head Start or community services as usual;direct...

  20. Head CT scan

    Science.gov (United States)

    ... be: Stored Viewed on a monitor Printed on film Three-dimensional models of the head area can ... when you have certain other signs or symptoms Hearing loss (in some people) Symptoms of damage to ...

  1. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... and other symptoms of aneurysm, bleeding, stroke and brain tumors. It also helps your doctor to evaluate your ... provides more detailed information on head injuries, stroke , brain tumors and other brain diseases than regular radiographs (x- ...

  2. Head and Neck Cancer

    Science.gov (United States)

    ... increase the risk of head and neck cancer. Environmental or occupational inhalants. Inhaling asbestos, wood dust, paint ... from the American Society of Clinical Oncology. Review dictionary articles to help understand medical phrases and terms ...

  3. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... used to detect: bleeding, brain injury and skull fractures in patients with head injuries. bleeding caused by ... are present in the paranasal sinuses. plan radiation therapy for cancer of the brain or other tissues. ...

  4. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... used to detect: bleeding, brain injury and skull fractures in patients with head injuries. bleeding caused by ... is also performed to: evaluate the extent of bone and soft tissue damage in patients with facial ...

  5. ORDNANCE CORPS VIEWS ELECTROMAGNETIC RADIATION HAZARDS TO WEAPONS SYSTEMS,

    Science.gov (United States)

    EXPLOSIVES INITIATORS, * ELECTROMAGNETIC RADIATION ), HAZARDS, ELECTROMAGNETIC SHIELDING, RADIOFREQUENCY POWER, ANTENNAS, ATTENUATORS, IMPEDANCE MATCHING, SENSITIVITY, WEAPON SYSTEMS, MODULATION, CIRCUITS, BROADBAND

  6. Electromagnetic Counterparts to Black Hole Mergers

    Science.gov (United States)

    Schnittman, Jeremy D.

    2011-01-01

    During the final moments of a binary black hole (BH) merger, the gravitational wave (GW) luminosity of the system is greater than the combined electromagnetic (EM) output of the entire observable universe. However, the extremely weak coupling between GWs and ordinary matter makes these waves very difficult to detect directly. Fortunately, the inspirating BH system will interact strongly-on a purely Newtonian level-with any surrounding material in the host galaxy, and this matter can in turn produce unique EM signals detectable at Earth. By identifying EM counterparts to GW sources, we will be able to study the host environments of the merging BHs, in turn greatly expanding the scientific yield of a mission like LISA. Here we present a comprehensive review of the recent literature on the subject of EM counterparts, as well as a discussion of the theoretical and observational advances required to fully realize the scientific potential of the field.

  7. Subject cataloguing of the works of fiction at the National and University Library

    Directory of Open Access Journals (Sweden)

    Tatjana Kovač

    2006-01-01

    Full Text Available The article reviews the principles of construction and policies of application of subject headings to works of fiction at the National and University Library in Ljubljana, Slovenia. The records are created in COMARC format, and the literary type, genre and the language of a document are each assigned a code, whereas literature is also indexed by using UDC class numbers. The principles for constructing and assigning subject headings for fiction are in accordance with the IFLA Principles Underlying Subject Heading Languages, and the rules of the Slovenian General List of Subject Headings (2002. The author presents the general and more specific rules and procedures for the construction of subject headings. Most frequently used subject headings for the works of fiction are name, topical or geographic headings.

  8. Effects of Soccer Heading on Brain Structure and Function

    Science.gov (United States)

    Rodrigues, Ana Carolina; Lasmar, Rodrigo Pace; Caramelli, Paulo

    2016-01-01

    Soccer is the most popular sport in the world, with more than 265 million players worldwide, including professional and amateur ones. Soccer is unique in comparison to other sports, as it is the only sport in which participants purposely use their head to hit the ball. Heading is considered as an offensive or defensive move whereby the player’s unprotected head is used to deliberately impact the ball and direct it during play. A soccer player can be subjected to an average of 6–12 incidents of heading the ball per competitive game, where the ball reaches high velocities. Moreover, in practice sessions, heading training, which involves heading the ball repeatedly at low velocities, is common. Although the scientific community, as well as the media, has focused on the effects of concussions in contact sports, the role of subconcussive impacts, as it can occur during heading, has recently gained attention, considering that it may represent an additional mechanism of cumulative brain injury. The purpose of this study is to review the existing literature regarding the effects of soccer heading on brain structure and function. Only in the last years, some investigations have addressed the impact of heading on brain structure, by using neuroimaging techniques. Similarly, there have been some recent studies investigating biochemical markers of brain injury in soccer players. There is evidence of association between heading and abnormal brain structure, but the data are still preliminary. Also, some studies have suggested that subconcussive head impacts, as heading, could cause cognitive impairment, whereas others have not corroborated this finding. Questions persist as to whether or not heading is deleterious to cognitive functioning. Further studies, especially with longitudinal designs, are needed to clarify the clinical significance of heading as a cause of brain injury and to identify risk factors. Such investigations might contribute to the establishment of safety

  9. Effects of soccer heading on brain structure and function

    Directory of Open Access Journals (Sweden)

    Ana Carolina Oliveira Rodrigues

    2016-03-01

    Full Text Available Soccer is the most popular sport in the world, with more than 265 million players worldwide, including professional and amateur ones. Soccer is unique in comparison to other sports, as it is the only sport in which participants purposely use their head to hit the ball. Heading is considered an offensive or defensive move whereby the player’s unprotected head is used to deliberately impact the ball and direct it during play. A soccer player can be subjected to an average of six to twelve incidents of heading the ball per competitive game, where the ball reaches high velocities. Moreover, in practice sessions, heading training, which involves heading the ball repeatedly at low velocities, is common. Although the scientific community, as well as the media, has focused on the effects of concussions in contact sports, the role of subconcussive impacts, as it can occur during heading, has recently gained attention, considering that it may represent an additional mechanism of cumulative brain injury. The purpose of this study is to review the existing literature regarding the effects of soccer heading on brain structure and function. Only in the last years some investigations have addressed the impact of heading on brain structure, by using neuroimaging techniques. Similarly, there have been some recent studies investigating biochemical markers of brain injury in soccer players. There is evidence of association between heading and abnormal brain structure, but the data are still preliminary. Also, some studies have suggested that subconcussive head impacts, as heading, could cause cognitive impairment, whereas others have not corroborated this finding. Questions persist as to whether or not heading is deleterious to cognitive functioning. Further studies, especially with longitudinal designs, are needed to clarify the clinical significance of heading as a cause of brain injury and to identify risk factors. Such investigations might contribute to the

  10. Assessment of SAR in the tissues near a cochlear implant exposed to radiofrequency electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Sibella, F; Parazzini, M; Paglialonga, A; Ravazzani, P [Istituto di Ingegneria Biomedica, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci, 32, 20133 Milano (Italy)], E-mail: federica.sibella@polimi.it, E-mail: marta.parazzini@polimi.it, E-mail: alessia.paglialonga@polimi.it, E-mail: paolo.ravazzani@polimi.it

    2009-04-21

    Cochlear implants (CI) are electronic devices used to restore partial hearing to people with severe hearing impairment. This paper aims to investigate if the introduction of a CI has an effect on SAR distribution in a head model exposed to radiofrequency electromagnetic fields (RF EMF) at mobile communication frequencies. The head model was obtained by image segmentation, the implant was modelled as a geometric structure and the exposure source was modelled as a uniform plane wave at 900 MHz, 1750 MHz and 1950 MHz, incident on the side of the head with the CI. Vertical and horizontal polarizations were simulated. Results show that the presence of a CI inside the cochlea produces negligible variations in the averaged SAR values, both in the head and in the cochlear tissues, although very localized differences in point SAR were found in the cochlea. Globally, these results suggest that finding harmful effects in the cochlear tissues will be unlikely. (note)

  11. Landau levels for electromagnetic wave

    CERN Document Server

    Zyuzin, Vladimir A

    2016-01-01

    In this paper we show that the frequencies of propagating electromagnetic wave (photon) in rotating dielectric media obey Landau quantization. We show that the degeneracy of right and left helicities of photons is broken on the lowest Landau level. In spatially homogeneous system this level is shown to be helical, i.e. left and right helical photons counter-propagate.

  12. Solved problems in classical electromagnetism

    CERN Document Server

    Franklin, Jerrold

    2018-01-01

    This original Dover publication is the companion to a new edition of the author's Classical Electromagnetism: Second Edition. The latter volume will feature only basic answers; this book will contain some problems from the reissue as well as many other new ones. All feature complete, worked-out solutions and form a valuable source of problem-solving material for students.

  13. Nanocomposites for electromagnetic radiation protection

    Science.gov (United States)

    Petrunin, V. F.

    2016-12-01

    Specific features that characterize nanoparticles and which are due to their small size and allow one to enhance the interaction between the electromagnetic radiation and nanostructured materials and to develop the effective protection of man and equipment against harmful uncontrolled radiation are reported. Examples of the development of nanocomposite radar absorbing materials that can be used for protection of man and equipment are presented.

  14. Electromagnetic Levitation of a Disc

    Science.gov (United States)

    Valle, R.; Neves, F.; de Andrade, R., Jr.; Stephan, R. M.

    2012-01-01

    This paper presents a teaching experiment that explores the levitation of a disc of ferromagnetic material in the presence of the magnetic field produced by a single electromagnet. In comparison to the classical experiment of the levitation of a sphere, the main advantage of the proposed laboratory bench is that the uniform magnetic field…

  15. Electromagnetic pulses bone healing booster

    Science.gov (United States)

    Sintea, S. R.; Pomazan, V. M.; Bica, D.; Grebenisan, D.; Bordea, N.

    2015-11-01

    Posttraumatic bone restoration triggered by the need to assist and stimulate compensatory bone growth in periodontal condition. Recent studies state that specific electromagnetic stimulation can boost the bone restoration, reaching up to 30% decrease in recovery time. Based on the existing data on the electromagnetic parameters, a digital electronic device is proposed for intra oral mounting and bone restoration stimulation in periodontal condition. The electrical signal is applied to an inductive mark that will create and impregnate magnetic field in diseased tissue. The device also monitors the status of the electromagnetic field. Controlled wave forms and pulse frequency signal at programmable intervals are obtained with optimized number of components and miniaturized using surface mounting devices (SMD) circuits and surface mounting technology (SMT), with enhanced protection against abnormal current growth, given the intra-oral environment. The system is powered by an autonomous power supply (battery), to limit the problems caused by powering medical equipment from the main power supply. Currently the device is used in clinical testing, in cycles of six up to twelve months. Basic principles for the electrical scheme and algorithms for pulse generation, pulse control, electromagnetic field control and automation of current monitoring are presented, together with the friendly user interface, suitable for medical data and patient monitoring.

  16. Airborne electro-magnetic system

    Energy Technology Data Exchange (ETDEWEB)

    1977-09-01

    Tridem is a three-frequency in-phase and quadrature measuring, fixed configuration, airborne electromagnetic system developed by Scintrex. It has been in operation in Canada since 1975. It is expected that the system will be used in high resolution, multiple natural resource surveys for base metals, uranium, sand and gravel, coal, lignite, groundwater and civil engineering purposes.

  17. Contributions of Maxwell to Electromagnetism

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 5. Contributions of Maxwell to Electromagnetism. P V Panat. General Article Volume 8 Issue 5 May 2003 pp 17-29. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/008/05/0017-0029. Keywords.

  18. Radiation leakage from electromagnetic oven

    Directory of Open Access Journals (Sweden)

    Abdurrahman Khalil

    2015-10-01

    Results & Discussions: The measurements have been done at some houses in Erbil city, according to the source of background radiation exist before measuring data. Our data compared with standard safe range of radiation data. Results showed that there is radiation leak form all type of electromagnetic oven and all at the order of safety compared with standard value.

  19. Cardiovascular Responses to Electromagnetic Radiation

    African Journals Online (AJOL)

    Dr Olaleye Samuel

    fatigue. ABSTRACT. Electromagnetic signaling has recently greatly increased due to mobile telephony and computers some of which radiate much and have wide spectra. The radiations are also reflected and thus form standing waves with incoming ones. In cities both the direct and reflected radiations form complex ...

  20. Nanocomposites for electromagnetic radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Petrunin, V. F., E-mail: VFPetrunin@mephi.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation)

    2016-12-15

    Specific features that characterize nanoparticles and which are due to their small size and allow one to enhance the interaction between the electromagnetic radiation and nanostructured materials and to develop the effective protection of man and equipment against harmful uncontrolled radiation are reported. Examples of the development of nanocomposite radar absorbing materials that can be used for protection of man and equipment are presented.

  1. Coordinates of Human Visual and Inertial Heading Perception.

    Directory of Open Access Journals (Sweden)

    Benjamin Thomas Crane

    Full Text Available Heading estimation involves both inertial and visual cues. Inertial motion is sensed by the labyrinth, somatic sensation by the body, and optic flow by the retina. Because the eye and head are mobile these stimuli are sensed relative to different reference frames and it remains unclear if a perception occurs in a common reference frame. Recent neurophysiologic evidence has suggested the reference frames remain separate even at higher levels of processing but has not addressed the resulting perception. Seven human subjects experienced a 2s, 16 cm/s translation and/or a visual stimulus corresponding with this translation. For each condition 72 stimuli (360° in 5° increments were delivered in random order. After each stimulus the subject identified the perceived heading using a mechanical dial. Some trial blocks included interleaved conditions in which the influence of ±28° of gaze and/or head position were examined. The observations were fit using a two degree-of-freedom population vector decoder (PVD model which considered the relative sensitivity to lateral motion and coordinate system offset. For visual stimuli gaze shifts caused shifts in perceived head estimates in the direction opposite the gaze shift in all subjects. These perceptual shifts averaged 13 ± 2° for eye only gaze shifts and 17 ± 2° for eye-head gaze shifts. This finding indicates visual headings are biased towards retina coordinates. Similar gaze and head direction shifts prior to inertial headings had no significant influence on heading direction. Thus inertial headings are perceived in body-centered coordinates. Combined visual and inertial stimuli yielded intermediate results.

  2. Long-Term Evolution Electromagnetic Fields Exposure Modulates the Resting State EEG on Alpha and Beta Bands.

    Science.gov (United States)

    Yang, Lei; Chen, Qinghua; Lv, Bin; Wu, Tongning

    2017-05-01

    Long-term evolution (LTE) wireless telecommunication systems are widely used globally, which has raised a concern that exposure to electromagnetic fields (EMF) emitted from LTE devices can change human neural function. To date, few studies have been conducted on the effect of exposure to LTE EMF. Here, we evaluated the changes in electroencephalogram (EEG) due to LTE EMF exposure. An LTE EMF exposure system with a stable power emission, which was equivalent to the maximum emission from an LTE mobile phone, was used to radiate the subjects. Numerical simulations were conducted to ensure that the specific absorption rate in the subject's head was below the safety limits. Exposure to LTE EMF reduced the spectral power and the interhemispheric coherence in the alpha and beta bands of the frontal and temporal brain regions. No significant change was observed in the spectral power and the inter-hemispheric coherence in different timeslots during and after the exposure. These findings also corroborated those of our previous study using functional magnetic resonant imaging.

  3. Pulsed radio-frequency electromagnetic fields: dose-dependent effects on sleep, the sleep EEG and cognitive performance.

    Science.gov (United States)

    Regel, Sabine J; Tinguely, Gilberte; Schuderer, Jürgen; Adam, Martin; Kuster, Niels; Landolt, Hans-Peter; Achermann, Peter

    2007-09-01

    To establish a dose-response relationship between the strength of electromagnetic fields (EMF) and previously reported effects on the brain, we investigated the influence of EMF exposure by varying the signal intensity in three experimental sessions. The head of 15 healthy male subjects was unilaterally exposed for 30 min prior to sleep to a pulse-modulated EMF (GSM handset like signal) with a 10 g-averaged peak spatial specific absorption rate of (1) 0.2 W kg(-1), (2) 5 W kg(-1), or (3) sham exposed in a double-blind, crossover design. During exposure, subjects performed two series of three computerized cognitive tasks, each presented in a fixed order [simple reaction time task, two-choice reaction time task (CRT), 1-, 2-, 3-back task]. Immediately after exposure, night-time sleep was polysomnographically recorded for 8 h. Sleep architecture was not affected by EMF exposure. Analysis of the sleep electroencephalogram (EEG) revealed a dose-dependent increase of power in the spindle frequency range in non-REM sleep. Reaction speed decelerated with increasing field intensity in the 1-back task, while accuracy in the CRT and N-back task were not affected in a dose-dependent manner. In summary, this study reveals first indications of a dose-response relationship between EMF field intensity and its effects on brain physiology as demonstrated by changes in the sleep EEG and in cognitive performance.

  4. Modeling of interactions of electromagnetic fields with human bodies

    Science.gov (United States)

    Caputa, Krzysztof

    Interactions of electromagnetic fields with the human body have been a subject of scientific interest and public concern. In recent years, issues in power line field effects and those of wireless telephones have been in the forefront of research. Engineering research compliments biological investigations by quantifying the induced fields in biological bodies due to exposure to external fields. The research presented in this thesis aims at providing reliable tools, and addressing some of the unresolved issues related to interactions with the human body of power line fields and fields produced by handheld wireless telephones. The research comprises two areas, namely development of versatile models of the human body and their visualisation, and verification and application of numerical codes to solve selected problems of interest. The models of the human body, which are based on the magnetic resonance scans of the body, are unique and differ considerably from other models currently available. With the aid of computer software developed, the models can be arranged to different postures, and medical devices can be accurately placed inside them. A previously developed code for modeling interactions of power line fields with biological bodies has been verified by rigorous, quantitative inter-laboratory comparison for two human body models. This code has been employed to model electromagnetic interference (EMI) of the magnetic field with implanted cardiac pacemakers. In this case, the correct placement and representation of the pacemaker leads are critical, as simplified computations have been shown to result in significant errors. In modeling interactions of wireless communication devices, the finite difference time domain technique (FDTD) has become a de facto standard. The previously developed code has been verified by comparison with the analytical solution for a conductive sphere. While previously researchers limited their verifications to principal axes of the sphere

  5. Health hazards and electromagnetic fields.

    Science.gov (United States)

    Saunders, T

    2003-11-01

    Biological rhythms, physical wellbeing and mental states are dependent on our electrical brainwave system interacting with the extremely weak electromagnetic fields generated by the Earth's telluric and Cosmic radiations. In a single generation, since the evolution of humankind over millions of years, we are exposed to a wide range of powerful, artificially generated electromagnetic radiation which adversely affects the subtle balance in nature's energy fields and has become the source of so-called 'diseases of civilization'. This also includes electromagnetic sensitivity. Generally, there is a lack of awareness and understanding of the impact electromagnetic fields can have upon health and wellbeing.Our ancestors were acutely aware that certain locations, were perceived to have a positive energy field which was beneficial to health and vitality. Over time, these areas are now referred to as sacred sites for spiritual ceremony and as healing centres. In contrast, there are other geographical locations that can have a negative effect upon health and these are known as geopathic stress zones. It is believed that such zones can interfere with the brain's normal function that inhibits the release of melatonin and other endocrine secretions needed to replenish the immune system. Geopathic stress can affect animals and plant life as well as human beings and significantly contributes to sick building syndrome (SBS). Whilst there is an increasing body of opinion amongst eminent researchers and scientists who are addressing these issues, the establishment professions are slow to change. However, very gradually, modern allopathic medicine and attitudes are beginning to recognise the extraordinary wisdom and efficacy of ancient traditions such as acupuncture, light, colour and other therapies based on the understanding and treatment of the interaction of a person's electromagnetic subtle body and the immediate environment. These and many other 'complementary' therapies may

  6. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head ... limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is ...

  7. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

  8. The Importance of Properly Compensating for Head Movements During MEG Acquisition Across Different Age Groups.

    Science.gov (United States)

    Larson, Eric; Taulu, Samu

    2017-03-01

    Unlike EEG sensors, which are attached to the head, MEG sensors are located outside the head surface on a fixed external device. Subject head movements during acquisition thus distort the magnetic field distributions measured by the sensors. Previous studies have looked at the effect of head movements, but no study has comprehensively looked at the effect of head movements across age groups, particularly in infants. Using MEG recordings from subjects ranging in age from 3 months through adults, here we first quantify the variability in head position as a function of age group. We then combine these measured head movements with brain activity simulations to determine how head movements bias source localization from sensor magnetic fields measured during movement. We find that large amounts of head movement, especially common in infant age groups, can result in large localization errors. We then show that proper application of head movement compensation techniques can restore localization accuracy to pre-movement levels. We also find that proper noise covariance estimation (e.g., during the baseline period) is important to minimize localization bias following head movement compensation. Our findings suggest that head position measurement during acquisition and compensation during analysis is recommended for researchers working with subject populations or age groups that could have substantial head movements. This is especially important in infant MEG studies.

  9. Risk perception and public concerns of electromagnetic waves from cellular phones in Korea.

    Science.gov (United States)

    Kim, Kyunghee; Kim, Hae-Joon; Song, Dae Jong; Cho, Yong Min; Choi, Jae Wook

    2014-05-01

    In this study, the difference between the risk perception of electromagnetic waves from cellular phones and the risk perception of other factors such as environment and food was analyzed. The cause of the difference in the psychological and social factors that affect the group with high risk perception of electromagnetic waves was also analyzed. A questionnaire survey on the risk perception of electromagnetic waves from cellular phones was carried out on 1001 subjects (men and women) over the age of 20. In the group with high risk perception of electromagnetic waves from cellular phones, women had higher risk perception than men. Logistic regression analysis, where the group with high risk perception of electromagnetic waves and the group with low risk perception were used as dependent variables, indicated that the risk perception of electromagnetic waves in women was 1.815 times statistically significantly higher than the risk perception of men (95% CI: 1.340-2.457). Also, high risk perception of electromagnetic waves from cellular phones was observed when the subjects considered that they had more personal knowledge (OR: 1.416, 95% CI: 1.216-1.648), that the seriousness of the risk to future generations was high (OR: 1.410, 95% CI: 1.234-1.611), and their outrage for the occurrence of accidents related to electromagnetic waves was high (OR: 1.460, 95% CI: 1.264-1.686). The results of this study need to be sufficiently considered and reflected in designing the risk communication strategies and communication methods for the preventive measures and advice on electromagnetic waves from cellular phones. © 2014 Wiley Periodicals, Inc.

  10. Susceptibility study of audio recording devices to electromagnetic stimulations

    Energy Technology Data Exchange (ETDEWEB)

    Halligan, Matthew S.; Grant, Steven.

    2014-02-01

    Little research has been performed to study how intentional electromagnetic signals may couple into recording devices. An electromagnetic susceptibility study was performed on an analog tape recorder, a digital video camera, a wired computer microphone, and a wireless microphone system to electromagnetic interference. Devices were subjected to electromagnetic stimulations in the frequency range of 1-990 MHz and field strengths up to 4.9 V/m. Carrier and message frequencies of the stimulation signals were swept, and the impacts of device orientation and antenna polarization were explored. Message signals coupled into all devices only when amplitude modulated signals were used as stimulation signals. Test conditions that produced maximum sensitivity were highly specific to each device. Only narrow carrier frequency ranges could be used for most devices to couple messages into recordings. A basic detection technique using cross-correlation demonstrated the need for messages to be as long as possible to maximize message detection and minimize detection error. Analysis suggests that detectable signals could be coupled to these recording devices under realistic ambient conditions.

  11. Fractional Calculus Based FDTD Modeling of Layered Biological Media Exposure to Wideband Electromagnetic Pulses

    Directory of Open Access Journals (Sweden)

    Luciano Mescia

    2017-11-01

    Full Text Available Electromagnetic fields are involved in several therapeutic and diagnostic applications such as hyperthermia and electroporation. For these applications, pulsed electric fields (PEFs and transient phenomena are playing a key role for understanding the biological response due to the exposure to non-ionizing wideband pulses. To this end, the PEF propagation in the six-layered planar structure modeling the human head has been studied. The electromagnetic field and the specific absorption rate (SAR have been calculated through an accurate finite-difference time-domain (FDTD dispersive modeling based on the fractional derivative operator. The temperature rise inside the tissues due to the electromagnetic field exposure has been evaluated using both the non-thermoregulated and thermoregulated Gagge’s two-node models. Moreover, additional parametric studies have been carried out with the aim to investigate the thermal response by changing the amplitude and duration of the electric pulses.

  12. A Study on the Influence of Electromagnetic Radiation on Nervous System

    Directory of Open Access Journals (Sweden)

    Dong Xinlin

    2015-01-01

    Full Text Available Being applied widely, electromagnetic wave is closely related with our life. But this material has brought pollutions to the environment as well as influences on functions of organisms. In order to explore the influence of electromagnetic radiation on nervous system, this paper takes adult mice on 35th day as research objects, designs a water maze experiment and explores features of escaping latency of mice in the control group and in the group with radiation. In this research, methods of building a GHz TEM cell and a simulation model of mouse head with AutoCAD 2010 and XFDTD are provided, verifying that the simulation model meets the needs of the experiment. It concludes that the electromagnetic radiation causes memory deterioration of mice, and exerts its certain influence on nervous system.

  13. A System for Electromagnetic Field Conversion

    DEFF Research Database (Denmark)

    2003-01-01

    A system is provided for conversion of a first electromagnetic field into a desired second electromagnetic field, for example for coupling modes between waveguides or into microstructured waveguides. The system comprises a complex spatial electromagnetic field converter that is positioned...... for reception of at least a part of the first electromagnetic field and that is adapted for conversion of the received field into the desired electromagnetic field, and wherein at least one of the first and second fields matches a mode of a microstructured waveguide. It is an important advantage of the present...

  14. Cross-spectral purity of electromagnetic fields.

    Science.gov (United States)

    Hassinen, Timo; Tervo, Jani; Friberg, Ari T

    2009-12-15

    We extend Mandel's scalar-wave concept of cross-spectral purity to electromagnetic fields. We show that in the electromagnetic case, assumptions similar to the scalar cross-spectral purity lead to a reduction formula, analogous with the one introduced by Mandel. We also derive a condition that shows that the absolute value of the normalized zeroth two-point Stokes parameter of two cross-spectrally pure electromagnetic fields is the same for every frequency component of the field. In analogy with the scalar theory we further introduce a measure of the cross-spectral purity of two electromagnetic fields, namely, the degree of electromagnetic cross-spectral purity.

  15. Visual prosody and speech intelligibility: head movement improves auditory speech perception.

    Science.gov (United States)

    Munhall, K G; Jones, Jeffery A; Callan, Daniel E; Kuratate, Takaaki; Vatikiotis-Bateson, Eric

    2004-02-01

    People naturally move their heads when they speak, and our study shows that this rhythmic head motion conveys linguistic information. Three-dimensional head and face motion and the acoustics of a talker producing Japanese sentences were recorded and analyzed. The head movement correlated strongly with the pitch (fundamental frequency) and amplitude of the talker's voice. In a perception study, Japanese subjects viewed realistic talking-head animations based on these movement recordings in a speech-in-noise task. The animations allowed the head motion to be manipulated without changing other characteristics of the visual or acoustic speech. Subjects correctly identified more syllables when natural head motion was present in the animation than when it was eliminated or distorted. These results suggest that nonverbal gestures such as head movements play a more direct role in the perception of speech than previously known.

  16. Pediatric head injury.

    Science.gov (United States)

    Tulipan, N

    1998-01-01

    Pediatric head injury is a public health problem that exacts a high price from patients, their families and society alike. While much of the brain damage in head-injured patients occurs at the moment of impact, secondary injuries can be prevented by aggressive medical and surgical intervention. Modern imaging devices have simplified the task of diagnosing intracranial injuries. Recent advances in monitoring technology have made it easier to assess the effectiveness of medical therapy. These include intracranial pressure monitoring devices that are accurate and safe, and jugular bulb monitoring which provides a continuous, qualitative measure of cerebral blood flow. The cornerstones of treatment remain hyperventilation and osmotherapy. Despite maximal treatment, however, the mortality and morbidity associated with pediatric head injury remains high. Reduction of this mortality and morbidity will likely depend upon prevention rather than treatment.

  17. Head and Neck Reconstruction.

    Science.gov (United States)

    Wong, Shannon; Melin, Alyson; Reilly, Debra

    2017-10-01

    Management of head and neck burns involves acute and intermediate phases. Acutely, the goals are establish a secure airway and treat life-threatening injuries. Then, optimize nutrition, assess extent of the burn, perform local wound care, and provide eye protection. Management depends on the degree of the head and neck burn. Postinjury splinting and rehabilitation are vital to healing. After the acute inflammation has resolved and the scars have matured, reconstruction begins with the goals of restoring both function and aesthetics. Reconstruction ranges from simple scar release, to skin grafting, and possibly free flap reconstruction. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Head first Ajax

    CERN Document Server

    Riordan, Rebecca M

    2008-01-01

    Ajax is no longer an experimental approach to website development, but the key to building browser-based applications that form the cornerstone of Web 2.0. Head First Ajax gives you an up-to-date perspective that lets you see exactly what you can do -- and has been done -- with Ajax. With it, you get a highly practical, in-depth, and mature view of what is now a mature development approach. Using the unique and highly effective visual format that has turned Head First titles into runaway bestsellers, this book offers a big picture overview to introduce Ajax, and then explores the use of ind

  19. A Review of Instrumented Equipment to Investigate Head Impacts in Sport

    OpenAIRE

    PATTON, Declan A.

    2016-01-01

    Contact, collision, and combat sports have more head impacts as compared to noncontact sports; therefore, such sports are uniquely suited to the investigation of head impact biomechanics. Recent advances in technology have enabled the development of instrumented equipment, which can estimate the head impact kinematics of human subjects in vivo. Literature pertaining to head impact measurement devices was reviewed and usage, in terms of validation and field studies, of such devices was discuss...

  20. Clinical measurement of compensatory torsional eye movement during head tilt.

    Science.gov (United States)

    Lim, Han Woong; Kim, Ji Hong; Park, Seung Hun; Oh, Sei Yeul

    2017-03-01

    To measure the degree of compensatory torsional eye movement during head tilt using a fundus photography method. We enrolled 55 healthy subjects who were 20-66 years of age. Fundus photographs were obtained in the presumed baseline position and in stepwise head tilt positions to evaluate ocular torsion using a non-mydriatic fundus camera. Horizontal marks on the nose were photographed simultaneously to evaluate head tilt. Images were analysed using Photoshop to measure the degree of ocular torsion and head tilt. A consistent compensatory torsional eye movement was observed in all subjects during head tilt. The degree of compensatory torsional eye movement showed a positive correlation with the angle of head tilt. Ocular torsional disconjugacy was observed during head tilt, with larger excycloductional eye movement than incycloductional eye movement (4.88 ± 2.91° versus 4.50 ± 2.76°, p eye movement was significantly associated with the degree of head tilt (β = 0.191, p eye movement. Considering the availability of fundus photography in clinical ophthalmology practice, the proposed method can be used as a clinical tool to measure compensatory torsional eye movement. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  1. Properties of dynamical electromagnetic metamaterials

    Science.gov (United States)

    Padilla, Willie J.; Averitt, Richard D.

    2017-08-01

    Electromagnetic metamaterials consist of two or three dimensional arrays of tailored metallic and/or dielectric inclusions and provide unprecedented sub-wavelength control over light-matter interactions. Metamaterials are fashioned to yield a specific response to the electric and magnetic components of light and may be treated as effective media, described by effective optical constants {μ }{{eff}} and {{ɛ }}{{eff}}, and have realized a multitude of exotic properties difficult to achieve with natural materials. An inductive-capacitive unit cell geometry provides enhanced values of optical constants, as well as the ability to dynamically control the novel responses exhibited by electromagnetic metamaterials. The ability of metamaterials to achieve real-time dynamic properties has realized novel applications and has made them relevant for the next revolution in advanced materials and related devices.

  2. Simple Electromagnetic Analysis in Cryptography

    Directory of Open Access Journals (Sweden)

    Zdenek Martinasek

    2012-07-01

    Full Text Available The article describes the main principle and methods of simple electromagnetic analysis and thus provides an overview of simple electromagnetic analysis.The introductions chapters describe specific SPA attack used visual inspection of EM traces, template based attack and collision attack.After reading the article, the reader is sufficiently informed of any context of SEMA.Another aim of the article is the practical realization of SEMA which is focused on AES implementation.The visual inspection of EM trace of AES is performed step by step and the result is the determination of secret key Hamming weight.On the resulting EM trace, the Hamming weight of the secret key 1 to 8 was clearly visible.This method allows reduction from the number of possible keys for following brute force attack.

  3. Asymptotic symmetries and electromagnetic memory

    Science.gov (United States)

    Pasterski, Sabrina

    2017-09-01

    Recent investigations into asymptotic symmetries of gauge theory and gravity have illuminated connections between gauge field zero-mode sectors, the corresponding soft factors, and their classically observable counterparts — so called "memories". Namely, low frequency emissions in momentum space correspond to long time integrations of the corre-sponding radiation in position space. Memory effect observables constructed in this manner are non-vanishing in typical scattering processes, which has implications for the asymptotic symmetry group. Here we complete this triad for the case of large U(1) gauge symmetries at null infinity. In particular, we show that the previously studied electromagnetic memory effect, whereby the passage of electromagnetic radiation produces a net velocity kick for test charges in a distant detector, is the position space observable corresponding to th Weinberg soft photon pole in momentum space scattering amplitudes.

  4. Relativistic approach to electromagnetic imaging

    OpenAIRE

    Budko, Neil

    2004-01-01

    A novel imaging principle based on the interaction of electromagnetic waves with a beam of relativistic electrons is proposed. Wave-particle interaction is assumed to take place in a small spatial domain, so that each electron is only briefly accelerated by the incident field. In the one-dimensional case the spatial distribution of the source density can be directly observed in the temporal spectrum of the scattered field. Whereas, in the two-dimensional case the relation between the source a...

  5. Electromagnetic Calorimeter for HADES Experiment

    Directory of Open Access Journals (Sweden)

    Rodríguez-Ramos P.

    2014-01-01

    Full Text Available Electromagnetic calorimeter (ECAL is being developed to complement dilepton spectrometer HADES. ECAL will enable the HADES@FAIR experiment to measure data on neutral meson production in heavy ion collisions at the energy range of 2-10 AGeV on the beam of future accelerator SIS100@FAIR. We will report results of the last beam test with quasi-monoenergetic photons carried out in MAMI facility at Johannes Gutenberg Universität Mainz.

  6. Health effects of electromagnetic fields.

    OpenAIRE

    Peter Gajšek

    1990-01-01

    Abstract: Devices that emit electromagnetic fields (EMF) have become a part of our daily life and can be found in telecommunications, industry, traffic, science, medicine and in every household. Due to the fact that general public is massively exposed to the EMF, even very small health effects could become a serious public health problem. Many studies show that the EMF above a certain threshold can have a negative health impact. The studies, which could explain the question of health risks as...

  7. Electromagnetism Tutorial (Tutorial de Eletromagnetismo)

    OpenAIRE

    Dantas, Christine C.

    2009-01-01

    The present tutorial aims at covering the fundamentals of electromagnetism, in a condensed and clear manner. Some solved and proposed exercises have been included. The reader is assumed to have knowledge of basic electricity, partial derivatives and multiple integrals. ----- O presente tutorial visa cobrir os fundamentos do eletromagnetismo, de forma condensada e clara. Alguns exercicios resolvidos e propostos foram incluidos. Assume-se conhecimento de eletricidade basica, derivadas parciais ...

  8. Exponential beams of electromagnetic radiation

    OpenAIRE

    Bialynicki-Birula, Iwo; Bialynicka-Birula, Zofia

    2006-01-01

    We show that in addition to well known Bessel, Hermite-Gauss, and Laguerre-Gauss beams of electromagnetic radiation, one may also construct exponential beams. These beams are characterized by a fall-off in the transverse direction described by an exponential function of rho. Exponential beams, like Bessel beams, carry definite angular momentum and are periodic along the direction of propagation, but unlike Bessel beams they have a finite energy per unit beam length. The analysis of these beam...

  9. Electromagnetic forces in photonic crystals

    OpenAIRE

    Antonoyiannakis, M. I.; Pendry, J. B.

    1998-01-01

    We develop a general methodology for numerical computations of electromagnetic (EM) fields and forces in matter, based on solving the macroscopic Maxwell's equations in real space and adopting the Maxwell Stress Tensor formalism. Our approach can be applied to both dielectric and metallic systems of frequency-dependent dielectric function; as well as to objects of any size and geometrical properties in principle. We are particularly interested in calculating forces on nanostructures. We find ...

  10. Do electromagnetic fields induce cancer?

    OpenAIRE

    飯島,純夫; 山縣, 然太朗; 浅香,昭雄

    1996-01-01

    Recently public concern about the carcinogenic effects of electromagnetic fields(EMF) has been increasing. We reviewed the published literature and current problems relating to possible carcinogenic effects of residential and occupational exposure to EMF. There are several suggestions that such an exposure may increase the risk of cancer, but these studies failed to provide conclusive indications. Further studies including improved prospective studies and biological experiments using EMF and ...

  11. Joint Electromagnetic Spectrum Management Operations

    Science.gov (United States)

    2012-03-20

    effects of EMP can extend to hundreds of kilometers depending on the height and yield of a nuclear burst. A high-altitude electromagnetic pulse ( HEMP ...can generate significant disruptive field strengths over a continental-size area. The portion of the EMS most affected by EMP and HEMP is the radio...commander can prohibit any RF emitter from operating when there is anticipated interference to mission-essential EM equipment. The installation

  12. The law of electromagnetic induction

    Directory of Open Access Journals (Sweden)

    V.J. Kutkovetskyy

    2014-09-01

    Full Text Available Mathematical models of the electromagnetic induction law which do not take into account Faraday’s restrictions are not in full accordance with the physical phenomenon and so they are not laws. Their incomplete correspondence with real devices results in such "paradoxes" as unlimited magnetic field of unipolar generators, infinite sizes of inductors for DC and AC machines modeled, and so on.

  13. Electromagnetic hypersensitivity: Fact or fiction?

    Energy Technology Data Exchange (ETDEWEB)

    Genuis, Stephen J., E-mail: sgenuis@ualberta.ca [University of Alberta (Canada); Lipp, Christopher T. [Faculty of Medicine at the University of Calgary (Canada)

    2012-01-01

    As the prevalence of wireless telecommunication escalates throughout the world, health professionals are faced with the challenge of patients who report symptoms they claim are connected with exposure to some frequencies of electromagnetic radiation (EMR). Some scientists and clinicians acknowledge the phenomenon of hypersensitivity to EMR resulting from common exposures such as wireless systems and electrical devices in the home or workplace; others suggest that electromagnetic hypersensitivity (EHS) is psychosomatic or fictitious. Various organizations including the World Health Organization as well as some nation states are carefully exploring this clinical phenomenon in order to better explain the rising prevalence of non-specific, multi-system, often debilitating symptoms associated with non-ionizing EMR exposure. As well as an assortment of physiological complaints, patients diagnosed with EHS also report profound social and personal challenges, impairing their ability to function normally in society. This paper offers a review of the sparse literature on this perplexing condition and a discussion of the controversy surrounding the legitimacy of the EHS diagnosis. Recommendations are provided to assist health professionals in caring for individuals complaining of EHS. - Highlights: Black-Right-Pointing-Pointer Many people report symptoms when near devices emanating electromagnetic fields(EMF). Black-Right-Pointing-Pointer Electromagnetic hypersensitivity (EHS) research has generated conflicting outcomes. Black-Right-Pointing-Pointer Recent evidence suggests pathophysiological change in some individuals with EHS. Black-Right-Pointing-Pointer EHS patients consistently report profound social and personal challenges. Black-Right-Pointing-Pointer Clinicians need to be apprised of the EHS condition and potential interventions.

  14. Electromagnetic interference of endodontic equipments with cardiovascular implantable electronic device.

    Science.gov (United States)

    Dadalti, Manoela Teixeira de Sant'Anna; da Cunha, Antônio José Ledo Alves; de Araújo, Marcos César Pimenta; de Moraes, Luis Gustavo Belo; Risso, Patrícia de Andrade

    2016-03-01

    Assess the electromagnetic interference (EMI) of endodontic equipment with cardiovascular implantable electronic devices (CIEDs) and related factors. The laser device, electronic apex locators (EAL), optical microscope, endodontic rotary motors, gutta-percha heat carrier (GH), gutta-percha gun and ultrasonic device were tested next to CIEDs (Medtronic and Biotronik) with varied sensitivity settings and distances. CIEDs were immersed in a saline solution to simulate the electrical resistence of the human body. The endodontic equipment was tested in both horizontal and vertical positions in relation to the components of the CIED. The tests were performed on a dental chair in order to assess the cumulative effect of electromagnetic fields. It was found no EMI with the Biotronik pacemaker. EALs caused EMI with Medtronic PM at a 2 cm distance, with the NSK(®) EAL also affecting the Medtronic defibrillator. GH caused EMI at 2 cm and 5 cm from the Medtronic defibrillator. EMI occurred when devices were horizontally positioned to the CIED. In the majority of the cases, EMI occurred when the pacemaker was set to maximum sensitivity. There was cumulative effect of electromagnetic fields between GH and dental chair. EALs and GH caused EMI which ranged according to type and sensitivity setting of the CIEDs and the distance. However, no endodontic equipment caused permanent damage to the CIED. The use of GH caused a cumulative effect of electromagnetic fields. It suggests that during the treatment of patients with CIEDs, only the necessary equipments should be kept turned on. Patients with CIEDs may be subject to EMI from electronic equipment used in dental offices, as they remain turned on throughout the treatment. This is the first article assessing the cumulative effect of electromagnetic fields. Copyright © 2016. Published by Elsevier Ltd.

  15. Head and neck position sense.

    Science.gov (United States)

    Armstrong, Bridget; McNair, Peter; Taylor, Denise

    2008-01-01

    Traumatic minor cervical strains are common place in high-impact sports (e.g. tackling) and premature degenerative changes have been documented in sports people exposed to recurrent impact trauma (e.g. scrummaging in rugby) or repetitive forces (e.g. Formula 1 racing drivers, jockeys). While proprioceptive exercises have been an integral part of rehabilitation of injuries in the lower limb, they have not featured as prominently in the treatment of cervical injuries. However, head and neck position sense (HNPS) testing and re-training may have relevance in the management of minor sports-related neck injuries, and play a role in reducing the incidence of ongoing pain and problems with function. For efficacious programmes to be developed and tested, fundamental principles associated with proprioception in the cervical spine should be considered. Hence, this article highlights the importance of anatomical structures in the cervical spine responsible for position sense, and how their interaction with the CNS affects our ability to plan and execute effective purposeful movements. This article includes a review of studies examining position sense in subjects with and without pathology and describes the effects of rehabilitation programmes that have sought to improve position sense. In respect to the receptors providing proprioceptive information for the CNS, the high densities and complex arrays of spindles found in cervical muscles suggest that these receptors play a key role. There is some evidence suggesting that ensemble encoding of discharge patterns from muscle spindles is relayed to the CNS and that a pattern recognition system is used to establish joint position and movement. Sensory information from neck proprioceptive receptors is processed in tandem with information from the vestibular system. There are extensive anatomical connections between neck proprioceptive inputs and vestibular inputs. If positional information from the vestibular system is inaccurate or

  16. Even Shallower Exploration with Airborne Electromagnetics

    Science.gov (United States)

    Auken, E.; Christiansen, A. V.; Kirkegaard, C.; Nyboe, N. S.; Sørensen, K.

    2015-12-01

    Airborne electromagnetics (EM) is in many ways undergoing the same type rapid technological development as seen in the telecommunication industry. These developments are driven by a steadily increasing demand for exploration of minerals, groundwater and geotechnical targets. The latter two areas demand shallow and accurate resolution of the near surface geology in terms of both resistivity and spatial delineation of the sedimentary layers. Airborne EM systems measure the grounds electromagnetic response when subject to either a continuous discrete sinusoidal transmitter signal (frequency domain) or by measuring the decay of currents induced in the ground by rapid transmission of transient pulses (time domain). In the last decade almost all new developments of both instrument hardware and data processing techniques has focused around time domain systems. Here we present a concept for measuring the time domain response even before the transient transmitter current has been turned off. Our approach relies on a combination of new instrument hardware and novel modeling algorithms. The newly developed hardware allows for measuring the instruments complete transfer function which is convolved with the synthetic earth response in the inversion algorithm. The effect is that earth response data measured while the transmitter current is turned off can be included in the inversion, significantly increasing the amount of available information. We demonstrate the technique using both synthetic and field data. The synthetic examples provide insight on the physics during the turn off process and the field examples document the robustness of the method. Geological near surface structures can now be resolved to a degree that is unprecedented to the best of our knowledge, making airborne EM even more attractive and cost-effective for exploration of water and minerals that are crucial for the function of our societies.

  17. Electromagnetic brake/clutch device

    Science.gov (United States)

    Vranish, John M.

    1994-01-01

    An electromagnetic brake/clutch device includes a drive shaft supported by at least one bearing for transmitting torque, a housing, affixed to prevent its rotation, surrounding the drive shaft, and an electromagnetically activated device within the housing to selectively prevent and allow rotation of the drive shaft. The electromagnetically activated device includes a plurality of cammed rollers to prevent counter-clockwise rotation of the drive shaft. The drive shaft includes a circumferential disk and the housing includes a reaction ring for engagement with the plurality of cammed rollers. The plurality of cammed rollers are released from engagement with the circumferential disk and the reaction ring by a plurality of tripping mechanisms within the housing. The tripping action uses the locking force to act as a release force merely by changing the boundary conditions of the roller interface angles. The tripping mechanisms include trippers for disengaging the plurality of cammed rollers and an anvil shaped portion for providing lateral movement of the trippers. The plurality of cammed rollers is preloaded to engagement with the circumferential disk and reaction ring by a spring, and is located with respect to an adjacent tripping mechanism with another spring.

  18. Electromagnetic Forming Rules of a Stiffened Panel with Grid Ribs

    Directory of Open Access Journals (Sweden)

    Jinqiang Tan

    2017-12-01

    Full Text Available Electromagnetic forming (EMF, a technology with advantages of contact-free force and high energy density, generally aims at forming parts by using a fixed coil and one-time discharge. In this study, multi-stage EMF is introduced to form a panel with stiffened grid ribs. The forming rules of the stiffened panel is revealed via analyzing the distribution and evolution of the simulated stress and strain in the ribs and web, where the grid-rib panels were decomposed as the flat panel and two panels with uni-directional ribs (ribs only in X direction or Y direction. It is shown that the forming depth is mainly attributed to the forces on the web, although electromagnetic force is applied on both the ribs and the web, especially, large force on the ribs. The ribs are subjected to uniaxial stress parallel to their directions, and the web is subjected to plane stress in the deformation region. Furthermore, the change of the uniaxial stress characteristic in the X-direction ribs is influenced by the electromagnetic force, reverse bend and inertial effect. The plastic deformation mainly occurs in the Y-direction ribs of the deformation region under a three-direction strain state.

  19. The effect of head movement and head positioning on sound field audiometry.

    Science.gov (United States)

    Shaw, Paul; Greenwood, Hannah

    2012-06-01

    Positioning and maintaining the subject's head at the calibration point (CP) of the sound field (SF) during SF assessment remains a challenge. The purpose of this study was to investigate the sound pressure level (SPL) at head positions likely to be encountered in routine audiological practice. Eight National Health Service SF clinics were used to obtain SPL measurements. Part 1 of the study investigated SPL variability at positions around the CP (0.15 m and 0.30 m). Parts 2 and 3 of the study, investigated the SPL at two typical head heights of the infant population. Only sound field measures were obtained. Part 1: 32% and 40% of measurements of SPL around the CP were >2 dB different from the SPL at the CP (0.15 m and 0.30 m). Parts 2 and 3: 55% and 38% of measurements of SPL, at the two infant head heights, were >2 dB from the SPL at the CP. Variability in SPL, due to head movement, is to be expected when performing SF audiometry. Furthermore, the typical head heights of infants will introduce additional variability, unless the position of the CP is chosen carefully.

  20. Enhancement of subject description of fiction with annotations

    Directory of Open Access Journals (Sweden)

    Alenka Šauperl

    2007-01-01

    Full Text Available In Slovenia, subject description of fiction was traditionally limited to the Universal Decimal Classification number, which was mainly assigned for shelving. Readers found their books by browsing the library shelves, while librarians had to rely on their personal familiarity with the library collection if they wanted to advise readers on the selection of books. Subject description, such as is often associated with non-literary works, would require a lot of time. Therefore, we wanted to know whether reading book reviews in newspapers could replace reading the entire literary work. We analysed a small sample of book reviews written by literary critics and published in Slovenian newspapers and compared them to the reviews, written by librarians for the same literary works (in the »Priporočamo!« project. We realized that the content is different. However, they could be used for identification of additional subject headings. The same findings resulted from a similar analysis of literary works written for children. Concepts, that seemed potentially appropriate subject headings, often actually do not appear in the Slovenian subject headings or subject headings from the Pionirska knjižnica of Ljubljana. Both subject heading lists should include a larger number of abstract concepts, which more often appear in literary than in non-literary works. Both subject heading lists should also be coordinated.

  1. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos ... head injuries, stroke , brain tumors and other brain diseases than regular radiographs (x-rays). top of page ...

  2. Lubricating the swordfish head

    NARCIS (Netherlands)

    Videler, John J.; Haydar, Deniz; Snoek, Roelant; Hoving, Henk-Jan T.; Szabo, Ben G.

    The swordfish is reputedly the fastest swimmer on Earth. The concave head and iconic sword are unique characteristics, but how they contribute to its speed is still unknown. Recent computed tomography scans revealed a poorly mineralised area near the base of the rostrum. Here we report, using

  3. Waco Head Start Program.

    Science.gov (United States)

    Porter, Para

    The Economic Opportunity Act of 1964 led to the formation of three separate Head Start Programs in Waco, Texas. The first year, 1,500 children were involved. Of these, 40 percent were Negro, 30 percent Latin American, and 30 percent white. All teachers received a week of preparatory study at the University of Texas. The program involved four areas…

  4. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head ...

  5. Ultrasound: Head (For Parents)

    Science.gov (United States)

    ... a safe and painless test that uses sound waves to make images of the brain. During the examination, an ultrasound machine sends sound ... The fontanel provides an opening for the sound waves to get through and reach the brain. Why It's Done Doctors order head ultrasounds when ...

  6. Silva as the Head

    DEFF Research Database (Denmark)

    Svabo, Connie

    2015-01-01

    The head of the performance design programme is substituted by a sister's academy delegate. this performance situation formed part of a week of semesterstart where the students and professors visited Sister's Academy, Malmø. I participated in the Sister's Academy as visiting researcher and here...

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams Blood Clots CT Perfusion of the Head CT Angiography ( ...

  8. Head nurses as middle managers.

    Science.gov (United States)

    Johnston, P F

    1983-11-01

    The relationship between head nurses and their staff nurses influences staff turnover rates and job satisfaction. In this article the author describes the measures taken by the management of Greater Southeast Community Hospital in response to an increasing turnover rate among staff RNs. In recognition of the head nurse role vis-d-vis attrition rates and job satisfaction, head nurses were upgraded to department head status and rigorous head nurse performance standards were developed. These standards required clinical expertise, managerial competence, and accountability. It is the author's contention that clinical practice and staff morale are directly related to a clearly defined head nurse role.

  9. Effect of radio frequency waves of electromagnetic field on the tubulin.

    Science.gov (United States)

    Taghi, Mousavi; Gholamhosein, Riazi; Saeed, Rezayi-Zarchi

    2013-09-01

    Microtubules (MTs) are macromolecular structures consisting of tubulin heterodimers and present in almost every eukaryotic cell. MTs fulfill all conditions for generation of electromagnetic field and are electrically polar due to the electrical polarity of a tubulin heterodimer. The calculated static electric dipole moment of about 1000 Debye makes them capable of being aligned parallel to the applied electromagnetic field direction. In the present study, the tubulin heterodimers were extracted and purified from the rat brains. MTs were obtained by polymerization in vitro. Samples of microtubules were adsorbed in the absence and in the presence of electromagnetic fields with radio frequency of 900 Hz. Our results demonstrate the effect of electromagnetic field with 900 Hz frequency to change the structure of MTs. In this paper, a related patent was used that will help to better understand the studied subject.

  10. Head injuries, heading, and the use of headgear in soccer.

    Science.gov (United States)

    Niedfeldt, Mark W

    2011-01-01

    Soccer has more than 265 million players around the world and is the only contact sport with purposeful use of the head for controlling and advancing the ball. Head contact in soccer has the potential to cause acute traumatic brain injury including concussion or, potentially, a pattern of chronic brain injury. Although early retrospective research on the effects of soccer heading seemed to suggest that purposeful heading may contribute to long-term cognitive impairment, prospective controlled studies do not support this and, in fact, suggest that purposeful heading may not be a risk factor for cognitive impairment. Headgear has not been shown to be effective in reducing ball impact but may be helpful in reducing the force of non-ball-related impacts to the head. There are concerns that universal use of headgear may cause more aggressive heading and head challenges, leading to increased risk of injury.

  11. Radial Head Fractures

    Science.gov (United States)

    Jordan, Robert W.; Jones, Alistair DR.

    2017-01-01

    Background: Radial head fractures are common elbow injuries in adults and are frequently associated with additional soft tissue and bone injuries. Methods: A literature search was performed and the authors’ personal experiences are reported. Results: Mason type I fractures are treated non-operatively with splinting and early mobilisation. The management of Mason type II injuries is less clear with evidence supporting both non-operative treatment and internal fixation. The degree of intra-articular displacement and angulation acceptable for non-operative management has yet to be conclusively defined. Similarly the treatment of type III and IV fractures remain controversial. Traditional radial head excision is associated with valgus instability and should be considered only for patients with low functional demands. Comparative studies have shown improved results from internal fixation over excision. Internal fixation should only be attempted when anatomic reduction and initiation of early motion can be achieved. Authors have reported that results from fixation are poorer and complication rates are higher if more than three fragments are present. Radial head arthroplasty aims to reconstruct the native head and is indicated when internal fixation is not feasible and in the presence of complex elbow injuries. Overstuffing of the radiocapitellar joint is a frequent technical fault and has significant adverse effects on elbow biomechanics. Modular design improves the surgeon’s ability to reconstruct the native joint. Two randomised controlled trials have shown improved clinical outcomes and lower complication rate following arthroplasty when compared to internal fixation. Conclusion: We have presented details regarding the treatment of various types of radial head fractures - further evidence, however, is still required to provide clarity over the role of these different management strategies. PMID:29290880

  12. Highly efficient proteolysis accelerated by electromagnetic waves for Peptide mapping.

    Science.gov (United States)

    Chen, Qiwen; Liu, Ting; Chen, Gang

    2011-09-01

    Proteomics will contribute greatly to the understanding of gene functions in the post-genomic era. In proteome research, protein digestion is a key procedure prior to mass spectrometry identification. During the past decade, a variety of electromagnetic waves have been employed to accelerate proteolysis. This review focuses on the recent advances and the key strategies of these novel proteolysis approaches for digesting and identifying proteins. The subjects covered include microwave-accelerated protein digestion, infrared-assisted proteolysis, ultraviolet-enhanced protein digestion, laser-assisted proteolysis, and future prospects. It is expected that these novel proteolysis strategies accelerated by various electromagnetic waves will become powerful tools in proteome research and will find wide applications in high throughput protein digestion and identification.

  13. Association of tinnitus and electromagnetic hypersensitivity: hints for a shared pathophysiology?

    Directory of Open Access Journals (Sweden)

    Michael Landgrebe

    Full Text Available BACKGROUND: Tinnitus is a frequent condition with high morbidity and impairment in quality of life. The pathophysiology is still incompletely understood. Electromagnetic fields are discussed to be involved in the multi-factorial pathogenesis of tinnitus, but data proofing this relationship are very limited. Potential health hazards of electromagnetic fields (EMF have been under discussion for long. Especially, individuals claiming themselves to be electromagnetic hypersensitive suffer from a variety of unspecific symptoms, which they attribute to EMF-exposure. The aim of the study was to elucidate the relationship between EMF-exposure, electromagnetic hypersensitivity and tinnitus using a case-control design. METHODOLOGY: Tinnitus occurrence and tinnitus severity were assessed by questionnaires in 89 electromagnetic hypersensitive patients and 107 controls matched for age-, gender, living surroundings and workplace. Using a logistic regression approach, potential risk factors for the development of tinnitus were evaluated. FINDINGS: Tinnitus was significantly more frequent in the electromagnetic hypersensitive group (50.72% vs. 17.5% whereas tinnitus duration and severity did not differ between groups. Electromagnetic hypersensitivity and tinnitus were independent risk factors for sleep disturbances. However, measures of individual EMF-exposure like e.g. cell phone use did not show any association with tinnitus. CONCLUSIONS: Our data indicate that tinnitus is associated with subjective electromagnetic hypersensitivity. An individual vulnerability probably due to an over activated cortical distress network seems to be responsible for, both, electromagnetic hypersensitivity and tinnitus. Hence, therapeutic efforts should focus on treatment strategies (e.g. cognitive behavioral therapy aiming at normalizing this dysfunctional distress network.

  14. From Engineering Electromagnetics to Electromagnetic Engineering: Using Computational Electromagnetics for Synthesis Problems

    OpenAIRE

    TIJHUIS, Anton G.; BEURDEN, Martijn C. van; HON, Bastiaan P. de

    2008-01-01

    In this paper, a two-stage approach is proposed for using computational electromagnetics in antenna engineering. First, stochastic optimization techniques are used in combination with approximate models. Second, line-search techniques are combined with full-wave modeling. For the first stage, we show an illustrative example. The second stage is considered in detail; both the acceleration of the underlying field computations and the implementation of the optimization are discussed.

  15. Advances and trends of head-up and head-down display systems in automobiles

    Science.gov (United States)

    Betancur, J. Alejandro; Osorio-Gomez, Gilberto; Agudelo, J. David

    2014-06-01

    Currently, in the automotive industry the interaction between drivers and Augmented Reality (AR) systems is a subject of analysis, especially the identification of advantages and risks that this kind of interaction represents. Consequently, this paper attempts to put in evidence the potential applications of Head-Up (Display (HUD) and Head-Down Display (HDD) systems in automotive vehicles, showing applications and trends under study. In general, automotive advances related to AR devices suggest the partial integration of the HUD and HDD in automobiles; however, the right way to do it is still a moot point.

  16. Antiplatelet therapy and the outcome of subjects with intracranial injury: the Italian SIMEU study

    OpenAIRE

    Fabbri, Andrea; Servadei, Franco; Marchesini, Giulio; Bronzoni, Carolina; Montesi, Danilo; Arietta, Luca

    2013-01-01

    Introduction Pre-injury antithrombotic therapy might influence the outcome of subjects with head injuries and positive computed tomography (CT) scans. We aimed to determine the potential risk of pre-injury antiplatelet drug use on short- and long-term outcome of head injured subjects admitted to emergency departments (EDs) in Italy for extended observation. Methods A total of 1,558 adult subjects with mild, moderate and severe head injury admitted to Italian EDs were studied. In multivariable...

  17. Voluntary head stabilization in space during trunk movements in weightlessness

    Science.gov (United States)

    Amblard, B.; Assaiante, C.; Fabre, J.-C.; Martin, N.; Massion, J.; Mouchnino, L.; Vernazza, S.

    The ability to voluntarily stabilize the head in space during lateral rhythmic oscillations of the trunk has been investigated during parabolic flights. Five healthy young subjects, who gave informed consent, were examined. The movements were performed with eyes open or eyes closed, either during phases of microgravity or phases of normal gravity. The main result to emerge from this study is that the head may be stabilized in space about the roll axis under microgravity conditions with, as well as without vision, despite the reduction of the vestibular afferent and the muscle proprioceptive inputs. Moreover, the absence of head stabilization about the yaw axis confirms that the degrees of freedom of the neck can be independently controlled, as it was previously shown [1]. These results seem to indicate that voluntary head stabilization does not depend crucially upon static vestibular afferents. Head stabilization in space may be in fact organized on the basis of either dynamic vestibular afferents or a postural body scheme.

  18. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful magnetic field, radio waves and a computer to produce ...

  19. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... content. Related Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain ...

  20. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to ...

  1. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... are the limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging ( ... brain) in routine clinical practice. top of page What are some common uses of the procedure? MR ...

  2. Childhood Head and Neck Irradiation

    Science.gov (United States)

    ... Thyroid Association ® www.thyroid.org Childhood Head & Neck Irradiation What is the thyroid gland? The thyroid gland ... Thyroid Association ® www.thyroid.org Childhood Head & Neck Irradiation Thyroid nodules (see Thyroid Nodule brochure) • Thyroid nodules ...

  3. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... for Brain Tumors Radiation Therapy for Head and Neck Cancer Others : American Stroke Association National Stroke Association ... MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging ( ...

  4. [Medical implantable devices and electromagnetic compatibility].

    Science.gov (United States)

    Andrivet, P

    2003-04-01

    Continuing progress in medicine has led to a corresponding population growth among the elderly population resulting in an increase in the number of patients with active implanted medical devices. At the same time, there continues to be a proliferation of electromagnetic wave sources within our technological environment. The coexistence of implanted active medical devices and environmental electromagnetic waves requires particular attention in order to avoid electromagnetic interference. For this reason, experts are more and more involved in writing specific manufacturing standards.

  5. Wireless Phones Electromagnetic Field Radiation Exposure Assessment

    OpenAIRE

    A. D. Usman; W. F.W. Ahmad; M. Z.A.A. Kadir; M. Mokhtar

    2009-01-01

    Problem statement: Inadequate knowledge of electromagnetic field emitted by mobile phones and increased usage at close proximity, created a lot of skepticism and speculations among end users on its safety or otherwise. Approach: In this study, near field electromagnetic field radiation measurements were conducted on different brand of mobile phones in active mode using a tri-axis isotropic probe and electric field meter. Results: The highest electromagnetic field exposure was recorded when th...

  6. Scattering of light and other electromagnetic radiation

    CERN Document Server

    Kerker, Milton

    1969-01-01

    The Scattering of Light and Other Electromagnetic Radiation discusses the theory of electromagnetic scattering and describes some practical applications. The book reviews electromagnetic waves, optics, the interrelationships of main physical quantities and the physical concepts of optics, including Maxwell's equations, polarization, geometrical optics, interference, and diffraction. The text explains the Rayleigh2 theory of scattering by small dielectric spheres, the Bessel functions, and the Legendre functions. The author also explains how the scattering functions for a homogenous sphere chan

  7. Anisotropic conducting films for electromagnetic radiation applications

    Science.gov (United States)

    Cavallo, Francesca; Lagally, Max G.; Rojas-Delgado, Richard

    2015-06-16

    Electronic devices for the generation of electromagnetic radiation are provided. Also provided are methods for using the devices to generate electromagnetic radiation. The radiation sources include an anisotropic electrically conducting thin film that is characterized by a periodically varying charge carrier mobility in the plane of the film. The periodic variation in carrier mobility gives rise to a spatially varying electric field, which produces electromagnetic radiation as charged particles pass through the film.

  8. The finite element method in electromagnetics

    CERN Document Server

    Jin, Jianming

    2014-01-01

    A new edition of the leading textbook on the finite element method, incorporating major advancements and further applications in the field of electromagnetics The finite element method (FEM) is a powerful simulation technique used to solve boundary-value problems in a variety of engineering circumstances. It has been widely used for analysis of electromagnetic fields in antennas, radar scattering, RF and microwave engineering, high-speed/high-frequency circuits, wireless communication, electromagnetic compatibility, photonics, remote sensing, biomedical engineering, and space exploration. The

  9. Advanced computational electromagnetic methods and applications

    CERN Document Server

    Li, Wenxing; Elsherbeni, Atef; Rahmat-Samii, Yahya

    2015-01-01

    This new resource covers the latest developments in computational electromagnetic methods, with emphasis on cutting-edge applications. This book is designed to extend existing literature to the latest development in computational electromagnetic methods, which are of interest to readers in both academic and industrial areas. The topics include advanced techniques in MoM, FEM and FDTD, spectral domain method, GPU and Phi hardware acceleration, metamaterials, frequency and time domain integral equations, and statistics methods in bio-electromagnetics.

  10. Electromagnetic wave analogue of electronic diode

    OpenAIRE

    Shadrivov, Ilya V.; Powell, David A.; Kivshar, Yuri S.; Fedotov, Vassili A.; Zheludev, Nikolay I.

    2010-01-01

    An electronic diode is a nonlinear semiconductor circuit component that allows conduction of electrical current in one direction only. A component with similar functionality for electromagnetic waves, an electromagnetic isolator, is based on the Faraday effect of the polarization state rotation and is also a key component of optical and microwave systems. Here we demonstrate a chiral electromagnetic diode, which is a direct analogue of an electronic diode: its functionality is underpinned by ...

  11. Homology in Electromagnetic Boundary Value Problems

    Directory of Open Access Journals (Sweden)

    Pellikka Matti

    2010-01-01

    Full Text Available We discuss how homology computation can be exploited in computational electromagnetism. We represent various cellular mesh reduction techniques, which enable the computation of generators of homology spaces in an acceptable time. Furthermore, we show how the generators can be used for setting up and analysis of an electromagnetic boundary value problem. The aim is to provide a rationale for homology computation in electromagnetic modeling software.

  12. Integral methods in low-frequency electromagnetics

    CERN Document Server

    Solin, Pavel; Karban, Pavel; Ulrych, Bohus

    2009-01-01

    A modern presentation of integral methods in low-frequency electromagnetics This book provides state-of-the-art knowledge on integral methods in low-frequency electromagnetics. Blending theory with numerous examples, it introduces key aspects of the integral methods used in engineering as a powerful alternative to PDE-based models. Readers will get complete coverage of: The electromagnetic field and its basic characteristics An overview of solution methods Solutions of electromagnetic fields by integral expressions Integral and integrodifferential methods

  13. Electromagnetic Compatibility for the Space Shuttle

    Science.gov (United States)

    Scully, Robert C.

    2004-01-01

    This slide presentation reviews the Space Shuttle electromagnetic compatibility (EMC). It includes an overview of the design of the shuttle with the areas that are of concern for the electromagnetic compatibility. It includes discussion of classical electromagnetic interference (EMI) and the work performed to control the electromagnetic interference. Another area of interest is electrostatic charging and the threat of electrostatic discharge and the attempts to reduce damage to the Shuttle from these possible hazards. The issue of electrical bonding is als reviewed. Lastly the presentation reviews the work performed to protect the shuttle from lightning, both in flight and on the ground.

  14. Electromagnetic Theory for Microwaves and Optoelectronics

    CERN Document Server

    Zhang, Keqian

    2007-01-01

    This book is a first year graduate text on electromagnetic fields and waves. At the same time it serves as a useful reference for researchers and engineers in the areas of microwaves and optoelectronics. Following the presentation of the physical and mathematical foundations of electromagnetic theory, the book discusses the field analysis of electromagnetic waves confined in material boundaries, or so-called guided waves, electromagnetic waves in the dispersive media and anisotropic media, Gaussian beams and scalar diffraction theory. The theories and methods presented in the book are foundations of wireless engineering, microwave and millimeter wave techniques, optoelectronics and optical fiber communication.

  15. Parallel QR Decomposition for Electromagnetic Scattering Problems

    National Research Council Canada - National Science Library

    Boleng, Jeff

    1997-01-01

    This report introduces a new parallel QR decomposition algorithm. Test results are presented for several problem sizes, numbers of processors, and data from the electromagnetic scattering problem domain...

  16. Visualization Of Electromagnetic Environment Near GSM Antennae

    Science.gov (United States)

    Zvezdina, M. Yu; Shokova, Yu A.; Kundryukova, N. I.; Kutukova, V. D.; Pozdnyakova, A. V.

    2017-01-01

    Web-enabled mobile phone enhancement has determined a sharp increase of mobile base station quantity, which has led to a surge of electromagnetic noise in metropolitan areas. Electromagnetic noise permanently influences adult and child population; the impossibility to remove this impact has promoted the electromagnetic monitoring. The most accessible form of socially oriented monitoring is a visualization of energy flux density for GSM base station antennae. Forecast calculation routines take antenna construction and location into an account; they also allow giving the recommendations on electromagnetic environment improvement basing on physical interpretation the obtained results.

  17. Electromagnetic Radiation Interface System and Method

    National Research Council Canada - National Science Library

    Steinbrecher, Donald H

    2005-01-01

    .... The termination section may comprise an electrical resistance for capturing substantially all the electromagnetic wave energy received by each respective bristle to thereby prevent reflections...

  18. Electromagnetic perturbations in new brane world scenarios

    Science.gov (United States)

    Molina, C.; Pavan, A. B.; Medina Torrejón, T. E.

    2016-06-01

    In this work, we consider electromagnetic dynamics in Randall-Sundrum branes. It is derived from a family of four-dimensional spacetimes compatible with Randall-Sundrum brane worlds, focusing on asymptotic flat backgrounds. Maximal extensions of the solutions are constructed, and their causal structures are discussed. These spacetimes include singular, nonsingular, and extreme black holes. Maxwell's electromagnetic field is introduced, and its evolution is studied in an extensive numerical survey. Electromagnetic quasinormal mode spectra are derived and analyzed with time-dependent and high-order WKB methods. Our results indicate that the black holes in the brane are electromagnetically stable.

  19. Head circumference in Iranian infants

    Directory of Open Access Journals (Sweden)

    Mohammad Esmaeili

    2015-03-01

    Full Text Available Introduction: Head circumference (HC measurement is one of the important parameter for diagnosis of neurological, developmental disorders and dysmorphic syndromes. Recognition of different disorders requires an understanding of normal variation for HC size, in particular, in infancy period with most rapid growth of the brain. Because of international and interracial standard chart differences about anthropometric indices, some differences from local to local, generation to generation and changes in ethnic mix of population and socioeconomic factors, periodic revolution of HC size is suggested. The aims of our study were presenting local HC standard for an Iranian infant population and comparison with the American national center of health statistics (NCHS charts accepted by WHO. Methods: 1003 subjects aged from birth to 24 months apparently healthy normal children enrolled randomly in this cross sectional study. HC size were measured and recorded. Tables and graphs were depicted by Excel Microsoft Office 2007. We use two tailed t-student test for statistical analysis. Results: The mean of HC size in boys was larger than girls. The curves were followed a similar pattern to NCHS based on a visual comparison. Overall our subjects in both sexes at birth time had smaller HC size than NCHS. In other ages our children had larger HC size than those of NCHS. Conclusion: Because of international and interracial difference of HC size. We recommend in each area of the world, local anthropometric indices are constructed and used clinically. In addition more extensive and longitudinally design comprehensive studies is suggested.

  20. Genetic parameters for subjectively assessed wool and ...

    African Journals Online (AJOL)

    admin

    The only noteworthy maternal correlation among wool traits was estimated between QUAL and COL at 0.39 ± 0.18 (Table 6). Table 5 Genetic (rg), phenotypic (rp), environmental (re) and maternal (rm) correlations (± s.e.) among subjectively assessed conformation traits. Trait rg re rp rm. General head conformation (GEN) X.

  1. Where are we heading

    Energy Technology Data Exchange (ETDEWEB)

    Noto, L.A. [Mobil Corporation, (United States)

    1996-12-31

    The present paper deals with different aspects connected to the global petroleum industry by discussing the way of heading. The aspects cover themes like new frontiers, new relationships, sanctions, global climate change, new alliances and new technology. New frontiers and relationships concern domestic policy affecting the industry, and sanctions are discussed in connection with trade. The author discusses the industry`s participation in the global environmental policy and new alliances to provide greater opportunity for developing new technology

  2. Radial Head Fractures

    OpenAIRE

    Jordan, Robert W.; Jones, Alistair DR.

    2017-01-01

    Background: Radial head fractures are common elbow injuries in adults and are frequently associated with additional soft tissue and bone injuries. Methods: A literature search was performed and the authors’ personal experiences are reported. Results: Mason type I fractures are treated non-operatively with splinting and early mobilisation. The management of Mason type II injuries is less clear with evidence supporting both non-operative treatment and internal fixation. The degree of intra-arti...

  3. Electromagnetic imaging and simulated annealing

    Science.gov (United States)

    Gibert, Dominique; Virieux, Jean

    1991-05-01

    In contrast with acoustical imaging methods, for which the wave field is dominated by propagation effects, electromagnetic imaging of conductive media suffers from the diffusive behavior of the electromagnetic field. An important question to address when working toward the achievement of electromagnetic imaging concerns the possibility of resolving the diffusion damping. Exact inversion will be looking at the solvability of the integral equation relating a diffusive field to its dual wavefield. This equation is ill posed because its Laplace-like kernel makes the inverse problem of finding the dual wave field a notoriously difficult (both numerically and mathematically) one. Stochastic inversion is another alternative based on least squares fitting. In this inverse problem approach, extracting the wave field is still a relatively instable process, although the L2 misfit function for data without noise presents a global minimum. The simulated annealing overcomes this instability for parameterization of this problem designed as follows. The unknown wave field is expected to be a sequence of impulsive functions. The number of impulsive functions can be determined by using a statistical criterion, called AIC, which comes from the Prony technique. The simulated annealing is applied to the positions of the reflections, while the amplitudes, which are not taken as parameters, are obtained by linear fitting. The simulated annealing method proves to be efficient even in the presence of noise. Furthermore, this nonlinear numerical inversion furnishes statistical quantities which allows an estimation of the resolution. Simple synthetic examples illustrate the performance of the inversion, while a synthetic finite element example shows the final pseudo-seismic section to be processed by standard seismic migration techniques.

  4. Electromagnetic effects on transportation systems

    Energy Technology Data Exchange (ETDEWEB)

    Morris, M.E.; Dinallo, M.A.

    1996-05-01

    Electronic and electrical system protection design can be used to eliminate deleterious effects from lightning, electromagnetic interference, and electrostatic discharges. Evaluation of conventional lightning protection systems using advanced computational modeling in conjunction with rocket-triggered lightning tests suggests that currently used lightning protection system design rules are inadequate and that significant improvements in best practices used for electronic and electrical system protection designs are possible. A case study of lightning induced upset and failure of a railway signal and control system is sketched.

  5. The CLAS forward electromagnetic calorimeter

    CERN Document Server

    Amarian, M; Beard, K; Brooks, W; Burkert, V; Carstens, T; Coleman, A; Demirchyan, R; Efremenko, Yu V; Egiyan, H; Egiyan, K; Funsten, H; Gavrilov, V; Giovanetti, K; Marshall, R M; Mecking, B; Minehart, R C; Mkrtchan, H; Ohandjanyan, M; Sharabyan, Yu G; Smith, L C; Stepanyan, S; Stephens, W A; Tung, T Y; Zorn, C

    2001-01-01

    The CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab utilizes six iron-free superconducting coils to provide an approximately toroidal magnetic field. The six sectors are instrumented individually to form six independent spectrometers. The forward region (8 deg. < 45 deg.) of each sector is equipped with a lead-scintillator electromagnetic sampling calorimeter (EC), 16 radiation lengths thick, using a novel triangular geometry with stereo readout. With its good energy and position resolution, the EC is used to provide the primary electron trigger for CLAS. It is also used to reject pions, reconstruct pi deg. and eta decays and detect neutrons. This paper treats the design, construction and performance of the calorimeter.

  6. Electromagnetic fields in fractal continua

    Energy Technology Data Exchange (ETDEWEB)

    Balankin, Alexander S., E-mail: abalankin@ipn.mx [Grupo “Mecánica Fractal”, Instituto Politécnico Nacional, México D.F., 07738 Mexico (Mexico); Mena, Baltasar [Instituto de Ingeniería, Universidad Nacional Autónoma de México, México D.F. (Mexico); Patiño, Julián [Grupo “Mecánica Fractal”, Instituto Politécnico Nacional, México D.F., 07738 Mexico (Mexico); Morales, Daniel [Instituto Mexicano del Petróleo, México D.F., 07730 Mexico (Mexico)

    2013-04-01

    Fractal continuum electrodynamics is developed on the basis of a model of three-dimensional continuum Φ{sub D}{sup 3}⊂E{sup 3} with a fractal metric. The generalized forms of Maxwell equations are derived employing the local fractional vector calculus related to the Hausdorff derivative. The difference between the fractal continuum electrodynamics based on the fractal metric of continua with Euclidean topology and the electrodynamics in fractional space F{sup α} accounting the fractal topology of continuum with the Euclidean metric is outlined. Some electromagnetic phenomena in fractal media associated with their fractal time and space metrics are discussed.

  7. Plasma scattering of electromagnetic radiation

    CERN Document Server

    Sheffield, John

    1975-01-01

    Plasma Scattering of Electromagnetic Radiation covers the theory and experimental application of plasma scattering. The book discusses the basic properties of a plasma and of the interaction of radiation with a plasma; the relationship between the scattered power spectrum and the fluctuations in plasma density; and the incoherent scattering of low-temperature plasma. The text also describes the constraints and problems that arise in the application of scattering as a diagnostic technique; the characteristic performance of various dispersion elements, image dissectors, and detectors; and the ge

  8. 2008+ solved problems in electromagnetics

    CERN Document Server

    Nasar, Syed

    2007-01-01

    SciTech Publishing is reissuing this extremely valuable learning resource, originally published in 1992 in the Schaum's Problem-Solving Series for students of electromagnetics and those who wish to refresh and solidify their understanding of its challenging applications. Problem-solving drill helps develop confidence, but few textbooks offer the answers, never mind the complete solutions, to their chapter exercises. Here noted author Professor Syed Nasar has divided the book's problems into topic areas similar to a textbook and presented a wide array of problems, followed immediately by their

  9. Electromagnetic fields, environment and health

    CERN Document Server

    Perrin, Anne

    2013-01-01

    A good number of false ideas are circulating on the effects of non-ionizing radiations on our health, which can lead to an oversimplification of the issue, to potentially dangerous misconceptions or to misleading data analysis. Health effects may be exaggerated, or on the contrary underplayed. The authors of this work (doctors, engineers and researchers) have endeavored to supply validated and easily understandable scientific information on the electromagnetic fields and their biological and health effects. After a general review of the physics of the waves and a presentation of non-ionizing r

  10. Continuum mechanics of electromagnetic solids

    CERN Document Server

    Maugin, GA

    1988-01-01

    This volume is a rigorous cross-disciplinary theoretical treatment of electromechanical and magnetomechanical interactions in elastic solids. Using the modern style of continuum thermomechanics (but without excessive formalism) it starts from basic principles of mechanics and electromagnetism, and goes on to unify these two fields in a common framework. It treats linear and nonlinear static and dynamic problems in a variety of elastic solids such as piezoelectrics, electricity conductors, ferromagnets, ferroelectrics, ionic crystals and ceramics. Chapters 1-3 are introductory, describing the e

  11. Head injuries in helmeted child bicyclists.

    Science.gov (United States)

    Grimard, G.; Nolan, T.; Carlin, J. B.

    1995-01-01

    OBJECTIVE: To determine the characteristics and the severity of head and facial injuries to helmeted child bicyclists, and whether the helmet contributed to the injury, and to study factors related to bicycle accidents. DESIGN: Retrospective review of two case series. Children sustaining head injury while not wearing helmets were studied as a form of reference group. SETTING: Large paediatric teaching hospital. SUBJECTS: 34 helmeted child bicyclists and 155 non-helmeted bicyclists, aged 5-14 years. MAIN OUTCOME MEASURES: Number of injuries, type of injuries, injury severity score, deaths, and accident circumstances. RESULTS: 79% of the head injuries of the helmeted child group were mild and two thirds of these had facial injuries. Children in the helmet group were in a greater proportion of bike-car collisions than the no helmet group and at least 15% of the helmets were lost on impact. There were no injuries secondary to the helmet. CONCLUSIONS: Most of the head injuries sustained by the helmeted children were of mild severity and there was no evidence to suggest that the helmet contributed to injury. Nevertheless, consideration should be given to designing a facial protector for the bicycle helmet and to improvement of the fastening device. PMID:9345988

  12. Electromagnets 1: Turn on the Power. Science in a Box.

    Science.gov (United States)

    Whitman, Betsy Blizard

    1992-01-01

    The article presents inexpensive activities to teach elementary school students about electromagnets. Students learn to make an electromagnet with a battery, nail, and wire, then different activities help them explore the difference between permanent magnets and electromagnets. (SM)

  13. Carotenoid intake and head and neck cancer: a pooled analysis in the International Head and Neck Cancer Epidemiology Consortium

    OpenAIRE

    Leoncini, Emanuele; Edefonti, Valeria; Hashibe, Mia; Parpinel, Maria; Cadoni, Gabriella; FERRARONI, MONICA; Serraino, Diego; Matsuo, Keitaro; Olshan, Andrew F.; Zevallos, Jose P.; Winn, Deborah M.; Moysich, Kirsten; Zhang, Zuo-Feng; Morgenstern, Hal; Levi, Fabio

    2015-01-01

    Food and nutrition play an important role in head and neck cancer (HNC) etiology; however, the role of carotenoids remains largely undefined. We explored the relation of HNC risk with the intake of carotenoids within the International Head and Neck Cancer Epidemiology Consortium. We pooled individual-level data from 10 case–control studies conducted in Europe, North America, and Japan. The analysis included 18,207 subjects (4414 with oral and pharyngeal cancer, 1545 with laryngeal cancer, and...

  14. The electromagnetic momentum of static charge-current distributions

    OpenAIRE

    Franklin, Jerrold

    2013-01-01

    The origin of electromagnetic momentum for general static charge-current distributions is examined. The electromagnetic momentum for static electromagnetic fields is derived by implementing conservation of momentum for the sum of mechanical momentum and electromagnetic momentum. The external force required to keep matter at rest during the production of the final static configuration produces the electromagnetic momentum. Examples of the electromagnetic momentum in static electric and magneti...

  15. Electromagnetic probes of the QGP

    Directory of Open Access Journals (Sweden)

    Bratkovskaya E. L.

    2015-01-01

    Full Text Available We investigate the properties of the QCD matter across the deconfinement phase transition in the scope of the parton-hadron string dynamics (PHSD transport approach. We present here in particular the results on the electromagnetic radiation, i.e. photon and dilepton production, in relativistic heavy-ion collisions. By comparing our calculations for the heavy-ion collisions to the available data, we determine the relative importance of the various production sources and address the possible origin of the observed strong elliptic flow v2 of direct photons. We argue that the different centrality dependence of the hadronic and partonic sources for direct photon production in nucleusnucleus collisions can be employed to shed some more light on the origin of the photon v2 “puzzle”. While the dilepton spectra at low invariant mass show in-medium effects like an enhancement from multiple baryonic resonance formation or a collisional broadening of the vector meson spectral functions, the dilepton yield at high invariant masses (above 1.1 GeV is dominated by QGP contributions for central heavy-ion collisions at ultra-relativistic energies. This allows to have an independent view on the parton dynamics via their electromagnetic massive radiation.

  16. Compton Sources of Electromagnetic Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Geoffrey Krafft,Gerd Priebe

    2011-01-01

    When a relativistic electron beam interacts with a high-field laser beam, intense and highly collimated electromagnetic radiation will be generated through Compton scattering. Through relativistic upshifting and the relativistic Doppler effect, highly energetic polarized photons are radiated along the electron beam motion when the electrons interact with the laser light. For example, X-ray radiation can be obtained when optical lasers are scattered from electrons of tens-of-MeV beam energy. Because of the desirable properties of the radiation produced, many groups around the world have been designing, building, and utilizing Compton sources for a wide variety of purposes. In this review article, we discuss the generation and properties of the scattered radiation, the types of Compton source devices that have been constructed to date, and the prospects of radiation sources of this general type. Due to the possibilities of producing hard electromagnetic radiation in a device that is small compared to the alternative storage ring sources, it is foreseen that large numbers of such sources may be constructed in the future.

  17. Flipping the Electromagnetic Theory classroom

    Science.gov (United States)

    Berger, Andrew J.

    2017-08-01

    Electromagnetic Theory is a required junior-year course for Optics majors at the University of Rochester. This foundational course gives students their first rigorous exposure to electromagnetic vector fields, dipole radiation patterns, Fresnel reflection/transmission coefficients, waveguided modes, Jones vectors, waveplates, birefringence, and the Lorentz model of refractive index. To increase the percentage of class time devoted to student-centered conceptual reasoning and instructor feedback, this course was recently "flipped". Nearly all of the mathematically-intensive derivations were converted to narrated screencasts ("Khan Academy" style) and made available to students through the course's learning management system. On average, the students were assigned two 10-15 minute videos to watch in advance of each lecture. An electronic survey after each tutorial encouraged reflection and counted towards the student's participation grade. Over the past three years, students have consistently rated the videos as being highly valuable. This presentation will discuss the technical aspects of creating tutorial videos and the educational tradeoffs of flipping a mathematically-intensive upper-level course. The most important advantage is the instructor's increased ability to identify and respond to student confusion, via activities that would consume too much time in a lecture-centered course. Several examples of such activities will be given. Two pitfalls to avoid are the temptation for the instructor not to update the videos from year to year and the tendency of students not to take lecture notes while watching the videos.

  18. Millimeter waves: acoustic and electromagnetic.

    Science.gov (United States)

    Ziskin, Marvin C

    2013-01-01

    This article is the presentation I gave at the D'Arsonval Award Ceremony on June 14, 2011 at the Bioelectromagnetics Society Annual Meeting in Halifax, Nova Scotia. It summarizes my research activities in acoustic and electromagnetic millimeter waves over the past 47 years. My earliest research involved acoustic millimeter waves, with a special interest in diagnostic ultrasound imaging and its safety. For the last 21 years my research expanded to include electromagnetic millimeter waves, with a special interest in the mechanisms underlying millimeter wave therapy. Millimeter wave therapy has been widely used in the former Soviet Union with great reported success for many diseases, but is virtually unknown to Western physicians. I and the very capable members of my laboratory were able to demonstrate that the local exposure of skin to low intensity millimeter waves caused the release of endogenous opioids, and the transport of these agents by blood flow to all parts of the body resulted in pain relief and other beneficial effects. Copyright © 2012 Wiley Periodicals, Inc.

  19. Transient electromagnetic sounding for groundwater

    Science.gov (United States)

    Fitterman, David V.; Stewart, Mark T.

    1986-01-01

    The feasibility of using the transient electromagnetic sounding (TS or TDEM) method for groundwater exploration can be studied by means of numerical models. As examples of its applicability to groundwater exploration, we study four groundwater exploration problems: (1) mapping of alluvial fill and gravel zones over bedrock; (2) mapping of sand and gravel lenses in till; (3) detection of salt or brackish water interfaces in freshwater aquifers; and (4) determination of hydrostratigraphy. These groundwater problems require determination of the depth to bedrock; location of resistive, high‐porosity zones associated with fresh water; determination of formation resistivity to assess water quality; and determination of lithology and geometry, respectively. The TS method is best suited for locating conductive targets, and has very good vertical resolution. Unlike other sounding techniques where the receiver‐transmitter array must be expanded to sound more deeply, the depth of investigation for the TS method is a function of the length of time the transient is recorded. Present equipment limitations require that exploration targets with resistivities of 50 Ω ⋅ m or more be at least 50 m deep to determine their resistivity. The maximum depth of exploration is controlled by the geoelectrical section and background electromagnetic (EM) noise. For a particular exploration problem, numerical studies are recommended to determine if the target is detectable.

  20. Electromagnetic hypersensitivity: fact or fiction?

    Science.gov (United States)

    Genuis, Stephen J; Lipp, Christopher T

    2012-01-01

    As the prevalence of wireless telecommunication escalates throughout the world, health professionals are faced with the challenge of patients who report symptoms they claim are connected with exposure to some frequencies of electromagnetic radiation (EMR). Some scientists and clinicians acknowledge the phenomenon of hypersensitivity to EMR resulting from common exposures such as wireless systems and electrical devices in the home or workplace; others suggest that electromagnetic hypersensitivity (EHS) is psychosomatic or fictitious. Various organizations including the World Health Organization as well as some nation states are carefully exploring this clinical phenomenon in order to better explain the rising prevalence of non-specific, multi-system, often debilitating symptoms associated with non-ionizing EMR exposure. As well as an assortment of physiological complaints, patients diagnosed with EHS also report profound social and personal challenges, impairing their ability to function normally in society. This paper offers a review of the sparse literature on this perplexing condition and a discussion of the controversy surrounding the legitimacy of the EHS diagnosis. Recommendations are provided to assist health professionals in caring for individuals complaining of EHS. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Electromagnetic survey of cornfield with repeated manure applications

    Energy Technology Data Exchange (ETDEWEB)

    Eigenberg, R.A.; Nienaber, J.A. [Agricultural Research Service, Clay Center, NE (United States). Meat Animal Research Center

    1998-11-01

    Waste management sites are subject to nutrient buildup from storage, treatment, and repeated application of manure. Methods are needed to quickly assess a site of field location to survey nutrient levels and estimate risk potential. Electromagnetic (EM) conductivity methods have been shown to be sensitive to areas of high nutrient levels and offer promise to provide field assessments. In this report, high density electromagnetic field mapping is described as a method to isolate and detect areas of nutrient buildup in a cornfield receiving waste management research treatments. Various manure and compost rates have been applied to this research field for replacement of commercial fertilizer with the treatment assignments remaining identical over a 4-yr period. Electromagnetic conductivity measurements were able to differentiate the N check treatment (commercial application rate) vs manure applied at the recommended P rate, compost applied at the P rate, and compost applied at the N rate. The N check treatment and the manure applied at the N rate treatment resulted in nearly identical mean values for EM readings and were not statistically distinguishable. Analysis of soil cores randomly located within each treatment were compared to EM readings at the same locations. The Pearson correlation coefficients revealed strong correlations for all constituents except NH{sub 4}. Treatment effects were significant for all soil constituents except NH{sub 4} and water content.

  2. Electromagnetic Radiation Originating from Unstable Electron Oscillations

    DEFF Research Database (Denmark)

    Juul Rasmussen, Jens; Pécseli, Hans

    1975-01-01

    Electromagnetic oscillations in the range 300 – 700 MHz were observed from an unmagnetized argon discharge with an unstable electron velocity distribution function.......Electromagnetic oscillations in the range 300 – 700 MHz were observed from an unmagnetized argon discharge with an unstable electron velocity distribution function....

  3. [Mechanisms of electromagnetic radiation damaging male reproduction].

    Science.gov (United States)

    Xue, Lei; Chen, Hao-Yu; Wang, Shui-Ming

    2012-08-01

    More and more evidence from over 50 years of researches on the effects of electromagnetic radiation on male reproduction show that a certain dose of electromagnetic radiation obviously damages male reproduction, particularly the structure and function of spermatogenic cells. The mechanisms of the injury may be associated with energy dysmetabolism, lipid peroxidation, abnormal expressions of apoptosis-related genes and proteins, and DNA damage.

  4. Electromagnetic Energy Localization and Characterization of Composites

    Science.gov (United States)

    2013-01-01

    Drewniak, and B. Archam- beault, “Numerical modeling of periodic composite media for electromagnetic shield - ing application,” 2007 IEEE Int. Symp. on...Electromagnetic Compatibility ( EMC 2007), July 9–13, 2007, pp. 1–5. [40] M. Luo, C. Liu, and H. P. Pan, “Numerical simulation on dielectric enhancement of

  5. High-Altitude Electromagnetic Pulse (HEMP) Testing

    Science.gov (United States)

    2015-07-09

    Final 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Test Operations Procedure (TOP) 01-2-620A High-Altitude Electromagnetic Pulse ( HEMP ...planning and execution of testing Army/DOD equipment to determine the effects of Horizontal Component High Altitude Electromagnetic Pulse ( HEMP ...5 2.3 HEMP Pre/Post Test Illuminations ..................................................... 7 3. REQUIRED TEST

  6. REFLECTION OF ELECTROMAGNETIC WAVES FROM SOUND WAVES

    Science.gov (United States)

    The reflection of electromagnetic waves normally incident on the wavefronts of a semi-infinite standing sound wave is discussed. By analogy with the...with the sound frequency. An experiment is described in which the Bragg reflection of 3 cm electromagnetic waves from a standing sound wave beneath a water surface is observed.

  7. Science 101: Can Electromagnetic Waves Affect Emotions?

    Science.gov (United States)

    Robertson, Bill

    The answer to this month's question, "Can electromagnetic waves affect emotions," is yes. Wherever there are electromagnetic (EM) waves (basically everywhere!), there is the potential for them directly or indirectly to affect the emotions. But what about the likely motivation behind the originally-posed question? Can EM waves affect your…

  8. Statistical measurements of fast changing electromagnetic fields

    NARCIS (Netherlands)

    Serra, Ramiro; Serra, Ramiro; Leferink, Frank Bernardus Johannes

    2010-01-01

    The present works aims at describing important statistical indexes such as the field uniformity, the field inhomogeneity and the statistics near the cavity walls for a special case of fast changing random electromagnetic fields. We generate this kind of electromagnetic environment by means of a

  9. Electromagnetic transition between molecular resonances in Be

    Indian Academy of Sciences (India)

    2014-11-04

    Nov 4, 2014 ... A crucial test of this conjecture is the electromagnetic transition between the molecular resonances. This paper ... Electromagnetic properties and transitions present a crucial test for any model or the- ory. ... triple coincidence measurement is necessary to reduce the background problem which is particularly ...

  10. simulation of electromagnetic transients in power systems

    African Journals Online (AJOL)

    Dr Obe

    1996-09-01

    Sep 1, 1996 ... Electromagnetic (EM) transients produced by these mathematical models serve as a useful reference in the design of protective devices and fault locators. ... with simulated fault data from electromagnetic. (EM) transients calculation. .... problem in the frequency domain and, finally, taking the inverse Fourier ...

  11. Electromagnetic Radiation from QCD Matter: Theory Overview

    OpenAIRE

    Shen, Chun

    2016-01-01

    Recent theory developments in electromagnetic radiation from relativistic heavy-ion collisions are reviewed. Electromagnetic observables can serve as a thermometer, a viscometer, and tomographic probes to the collision system. The current status of the "direct photon flow puzzle" is highlighted.

  12. Project Physics Tests 4, Light and Electromagnetism.

    Science.gov (United States)

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    Test items relating to Project Physics Unit 4 are presented in this booklet. Included are 70 multiple-choice and 22 problem-and-essay questions. Concepts of light and electromagnetism are examined on charges, reflection, electrostatic forces, electric potential, speed of light, electromagnetic waves and radiations, Oersted's and Faraday's work,…

  13. ELECTROMAGNETIC APPARATUS FOR MOVING A ROD

    Science.gov (United States)

    Young, J.N.

    1957-08-20

    An electromagnetic device for moving an object in a linear path by increments is described. The device is specifically adapted for moving a neutron absorbing control rod into and out of the core of a reactor and consists essentially of an extension member made of magnetic material connected to one end of the control rod and mechanically flexible to grip the walls of a sleeve member when flexed, a magnetic sleeve member coaxial with and slidable between limit stops along the flexible extension, electromagnetic coils substantially centrally located with respect to the flexible extension to flex the extension member into gripping engagement with the sleeve member when ener gized, moving electromagnets at each end of the sleeve to attract the sleeve when energized, and a second gripping electromagnet positioned along the flexible extension at a distance from the previously mentioned electromagnets for gripping the extension member when energized. In use, the second gripping electromagnet is deenergized, the first gripping electromagnet is energized to fix the extension member in the sleeve, and one of the moving electromagnets is energized to attract the sleeve member toward it, thereby moving the control rod.

  14. International Conference on Microelectronics, Electromagnetics and Telecommunications

    CERN Document Server

    Rao, N; Kumar, S; Raj, C; Rao, V; Sarma, G

    2016-01-01

    This volume contains 73 papers presented at ICMEET 2015: International Conference on Microelectronics, Electromagnetics and Telecommunications. The conference was held during 18 – 19 December, 2015 at Department of Electronics and Communication Engineering, GITAM Institute of Technology, GITAM University, Visakhapatnam, INDIA. This volume contains papers mainly focused on Antennas, Electromagnetics, Telecommunication Engineering and Low Power VLSI Design.

  15. CALICE silicon–tungsten electromagnetic calorimeter

    Indian Academy of Sciences (India)

    paradigm', to be successful optimal interplay between hardware, i.e. granularity, and software, i.e. reconstruction algorithms is required. CALICE plans include studies of both electromagnetic and hadronic calorime- ter prototypes. The electromagnetic prototype is a sampling calorimeter with W absorber and Si pads as ...

  16. Ultimate Energy Densities for Electromagnetic Pulses

    OpenAIRE

    Tsang, Mankei

    2008-01-01

    The ultimate electric and magnetic energy densities that can be attained by bandlimited electromagnetic pulses in free space are calculated using an ab initio quantized treatment, and the quantum states of electromagnetic fields that achieve the ultimate energy densities are derived. The ultimate energy densities also provide an experimentally accessible metric for the degree of localization of polychromatic photons.

  17. Pulsed Electromagnetic Acceleration of Plasma: A Review

    Science.gov (United States)

    Thio, Y. C. Francis; Turchi, Peter J.; Markusic, Thomas E.; Cassibry, Jason T.; Sommer, James; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    Much have been learned in the acceleration mechanisms involved in accelerating a plasma electromagnetically in the laboratory over the last 40 years since the early review by Winston Bostik of 1963, but the accumulated understanding is very much scattered throughout the literature. This literature extends back at least to the early sixties and includes Rosenbluth's snowplow model, discussions by Ralph Lovberg, Colgate's boundary-layer model of a current sheet, many papers from the activity at Columbia by Robert Gross and his colleagues, and the relevant, 1-D unsteady descriptions developed from the U. of Maryland theta-pinch studies. Recent progress on the understanding of the pulsed penetration of magnetic fields into collisionless or nearly collisionless plasmas are also be reviewed. Somewhat more recently, we have the two-dimensional, unsteady results in the collisional regime associated with so-called wall-instability in large radius pinch discharges and also in coaxial plasma guns (e.g., Plasma Flow Switch). Among other things, for example, we have the phenomenon of a high- density plasma discharge propagating in a cooaxial gun as an apparently straight sheet (vs paraboloid) because mass re-distribution (on a microsecond timescale) compensates for the 1/r- squared variation of magnetic pressure. We will attempt to collate some of this vast material and bring some coherence tc the development of the subject.

  18. Optimization and inverse problems in electromagnetism

    CERN Document Server

    Wiak, Sławomir

    2003-01-01

    From 12 to 14 September 2002, the Academy of Humanities and Economics (AHE) hosted the workshop "Optimization and Inverse Problems in Electromagnetism". After this bi-annual event, a large number of papers were assembled and combined in this book. During the workshop recent developments and applications in optimization and inverse methodologies for electromagnetic fields were discussed. The contributions selected for the present volume cover a wide spectrum of inverse and optimal electromagnetic methodologies, ranging from theoretical to practical applications. A number of new optimal and inverse methodologies were proposed. There are contributions related to dedicated software. Optimization and Inverse Problems in Electromagnetism consists of three thematic chapters, covering: -General papers (survey of specific aspects of optimization and inverse problems in electromagnetism), -Methodologies, -Industrial Applications. The book can be useful to students of electrical and electronics engineering, computer sci...

  19. Electromagnetic Interference on Large Wind Turbines

    Directory of Open Access Journals (Sweden)

    Florian Krug

    2009-11-01

    Full Text Available Electromagnetic interference (EMI can both affect and be transmitted by mega-watt wind turbines. This paper provides a general overview on EMI with respect to mega-watt wind turbines. Possibilities of measuring all types of electromagnetic interference are shown. Electromagnetic fields resulting from a GSM transmitter mounted on a mega-watt wind turbine will be analyzed in detail. This cellular system operates as a real-time communication link. The method-of-moments is used to analytically describe the electro-magnetic fields. The electromagnetic interference will be analyzed under the given boundary condition with a commercial simulation tool. Different transmitter positions are judged on the basis of their radiation patterns. The principal EMI mechanisms are described and taken into consideration.

  20. Human reactions to electromagnetic radiation in millimeter range

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, E.A.; Belyy, M.U.; Sit' ko, S.P.

    1985-01-01

    The article deals with a problem that is on the boundary of different disciplines. The authors discovered previously unknown effects of low-energy electromagnetic radiation on the human body. A total of 188 subjects, both healthy and sick in terms of medical diagnosis, were submitted to sensory tests. The vast majority of healthy subjects did not react to radiation in the range of 27-78 GHz and power density of up to 10 mW/cm/sup 2/. The same situation was also observed in many cases with patients. However, exposure of very specific parts of the body of sick subjects to electromagnetic waves at a fixed frequency in the range of 45-65 GHz elicited a sensory reaction in the region of the organ with a marked impairment, and this was an organ that was spatially remote from the irradiated region. It was established that the zones on the surface of the body that are the most sensitive to radiation coincide with acupuncture zones that are known in reflex acupuncture therapy. In addition to presentation of experimental results, the authors also propose a theoretical interpretation of the demonstrated effects.