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Sample records for acoustic esr

  1. ESR Dosimetry

    ESR dosimetry is widely used for several applications such as dose assessment in accidents, medical applications and sterilization of food and other materials. In this work the dosimetric properties of natural and synthetic Hydroxyapatite, Alanine, and 2-Methylalanine are presented. Recent results on the use of a K-Band (24 GHz) ESR spectrometer in dosimetry are also presented

  2. ESR dating of pseudotachylite

    Shimada, A.; Toyoda, S.; Takagi, H.; Arita, K.

    2002-12-01

    ESR (electron spin resonance) dating method has been used to determine the ages of quaternary events. When a mineral receives natural radiation, a part of paired electrons in quartz are ionized, and are trapped by lattice defects and impurties as unpaired electrons. The amount of unpaired electrons increases with time. The ESR age is obtained by dividing the total dose of natural radiation by the natural dose rate. Gamma ray doses are given to the sample to obtain the total dose by extrapolating the dose response of the signal intensity to the zero ordinate. The natural dose rate is calculated from U, Th, and K concentrations, and so on. Quartz is one of the promising minerals useful for ESR dating. In the present paper, we attempted to obtain ages of a land slide event. We collected pseudotachylite from Lantan, Himalaya. A land of about 4 km in diameter has found to have slid several kilometers resulting in pseudotachylite at the base. The samples were gently crushed sieved and soaked in 6N HCl for 1 night and then in 20% HF for two hours, but quartz grains were too small to be extracted. However, ESR signals of characteristic quartz were observed. As long as the sample is uniform, it is not crucial to extract pure quartz grains. With the usual procedure of ESR dating, gamma ray irradiation and ESR measurements, we obtained accumulated natural doses of 290 to 450 Gy. The concentrations of radioactive elements, K, U, Th, which give most of the natural dose to quartz grains, were measured by the low background gamma ray spectrometry. We obtained 7.62 ppm of uranium, 21.1 ppm of thorium, and 3.72% of K2O. Assuming the cosmic dose rate of 0.1mGy/y, we obtained 6.08 mGy/y as the natural dose rate. The ESR ages are obtained by dividing the accumulated doses by the natural dose rate to be 49ka from Al center signal (an electronic hole trapped at Al impurity in quartz) and 74ka from Ti center signal (an electron trapped at Ti impurity in quartz) for a sample, and 56ka and

  3. Acoustic detection of electron spin resonance

    Coufal, H.

    1981-07-01

    The ESR-signal of DPPH was recorded by detecting the modulation of the absorbed microwave power with a gas-coupled microphone. This photo-acoustic detection scheme is compared with conventional ESR-detection. Applications of the acoustical detection method to other modulation spectroscopic techniques, particularly NMR, are discussed.

  4. Acoustics

    Goodman, Jerry R.; Grosveld, Ferdinand

    2007-01-01

    The acoustics environment in space operations is important to maintain at manageable levels so that the crewperson can remain safe, functional, effective, and reasonably comfortable. High acoustic levels can produce temporary or permanent hearing loss, or cause other physiological symptoms such as auditory pain, headaches, discomfort, strain in the vocal cords, or fatigue. Noise is defined as undesirable sound. Excessive noise may result in psychological effects such as irritability, inability to concentrate, decrease in productivity, annoyance, errors in judgment, and distraction. A noisy environment can also result in the inability to sleep, or sleep well. Elevated noise levels can affect the ability to communicate, understand what is being said, hear what is going on in the environment, degrade crew performance and operations, and create habitability concerns. Superfluous noise emissions can also create the inability to hear alarms or other important auditory cues such as an equipment malfunctioning. Recent space flight experience, evaluations of the requirements in crew habitable areas, and lessons learned (Goodman 2003; Allen and Goodman 2003; Pilkinton 2003; Grosveld et al. 2003) show the importance of maintaining an acceptable acoustics environment. This is best accomplished by having a high-quality set of limits/requirements early in the program, the "designing in" of acoustics in the development of hardware and systems, and by monitoring, testing and verifying the levels to ensure that they are acceptable.

  5. ESR teleradiology survey: results.

    2016-08-01

    With recent developments of teleradiology technology and services, it has become necessary to better evaluate its extent and use among different countries in Europe. With this goal in mind, the ESR launched two specific surveys intended to gather the current state of adoption and implementation of teleradiology in clinical practice. A special focus on differentiating between insourcing teleradiology services among partners of the same organisation and outsourcing to external services was an essential part of the design of these surveys. The first survey was addressed to 44 national societies of different countries in Europe, while the second survey was intended for all practicing radiologist ESR members. While the results of these surveys reported here may provide a wealth of information to better understand the trends in adoption of teleradiology in Europe, they only represent a snapshot at a certain point in time. The rapid development of telecommunication tools as well as a fundamental change in practice and healthcare economics will certainly influence these observations in the upcoming years. These data, however, will provide objective and relevant parameters for supporting the efforts of experts and policy makers in promoting appropriate criteria and guidelines for adequate use of teleradiology in clinical practice. Main Messages • Understand concepts and challenges of teleradiology • Provide insight into current trends and solutions for teleradiology • Compare differences in teleradiolgy strategies between countries in Europe • Establish a reference on statistical data of usage of teleradiology in Europe. PMID:27188379

  6. ESR detection of irradiated seashells

    Raffi, J. [Laboratoire de Recherche sur la Qualite des Aliments, Faculte de Saint-Jerome, Marseille (France); Hasbany, C. [Laboratoire de Recherche sur la Qualite des Aliments, Faculte de Saint-Jerome, Marseille (France)]|[Laboratoire de Chimie des Produits Naturels, Faculte de Saint-Jerome, Marseille (France); Lesgards, G. [Laboratoire de Chimie des Produits Naturels, Faculte de Saint-Jerome, Marseille (France); Ochin, D. [Institut Agricol et Alimentaire de Lille (France). Lab. de Microbiologie et d`Hygiene Alimentaire

    1996-11-01

    Among the protocols for identification of irradiated foodstuffs submitted to the European Committee of Standardization, two using ESR (food containing bone or cellulose) were finally accepted as official `draft European standards` in Berlin on 9-10 June 1994. We present here some new results for oyster and mussel shells, and an ESR draft protocol is proposed. (author).

  7. ESR dosimetry: achievements and challenges

    Baffa, O., E-mail: baffa@usp.br [Universidade de Sao Paulo, Departamento de Fisica, Av. Bandeirantes 3900, 14040-901 Ribeirao Preto, Sao Paulo (Brazil)

    2015-10-15

    Full text: Electron Spin Resonance (ESR), also known as Electron Paramagnetic Resonance (EPR) and more recently as Electron Magnetic Resonance (Emr), is a spectroscopy technique able to detect unpaired electrons such as those created by the interaction ionizing radiation with matter. When the unpaired electrons created by ionizing radiation are stable over some reasonable time, ESR can be used to measure the radiation dose deposited in the material under study. In principle, any insulating material that satisfies this requisite can be used as a dosimeter. ESR has been used in retrospective dosimetry in case of radiological accidents using natural constituents of human body such as teeth, bones and nails as well as fortuitous materials as sugar, sweeteners and plastics. When using teeth the typical detected dose is 0.5 Gy for, for X-Band spectrometers (9 GHz) and even lower doses if higher frequency spectrometers are used. Clinical dosimetry is another area of potential use of this dosimetric modality. In this application the amino acid alanine has been proposed and being used. Alanine dosimeters are very easy to prepare and require no complicated treatments for use. Alanine/ESR dosimetry satisfies many of the required properties for clinical applications such as water equivalent composition, independence of response for the energy range used in therapy and high precision. Other organic materials such as ammonium tartrate are being investigated to increase the sensitivity of ESR for clinical applications. Finally, industrial applications can also benefit from this dosimetry. The challenges to expand applications, the number of users and research groups of ESR dosimetry will be discussed. (Author)

  8. ESR dosimetry: achievements and challenges

    Full text: Electron Spin Resonance (ESR), also known as Electron Paramagnetic Resonance (EPR) and more recently as Electron Magnetic Resonance (Emr), is a spectroscopy technique able to detect unpaired electrons such as those created by the interaction ionizing radiation with matter. When the unpaired electrons created by ionizing radiation are stable over some reasonable time, ESR can be used to measure the radiation dose deposited in the material under study. In principle, any insulating material that satisfies this requisite can be used as a dosimeter. ESR has been used in retrospective dosimetry in case of radiological accidents using natural constituents of human body such as teeth, bones and nails as well as fortuitous materials as sugar, sweeteners and plastics. When using teeth the typical detected dose is 0.5 Gy for, for X-Band spectrometers (9 GHz) and even lower doses if higher frequency spectrometers are used. Clinical dosimetry is another area of potential use of this dosimetric modality. In this application the amino acid alanine has been proposed and being used. Alanine dosimeters are very easy to prepare and require no complicated treatments for use. Alanine/ESR dosimetry satisfies many of the required properties for clinical applications such as water equivalent composition, independence of response for the energy range used in therapy and high precision. Other organic materials such as ammonium tartrate are being investigated to increase the sensitivity of ESR for clinical applications. Finally, industrial applications can also benefit from this dosimetry. The challenges to expand applications, the number of users and research groups of ESR dosimetry will be discussed. (Author)

  9. ESR Perspective on Clinical Audit

    Maurizio Centonze

    2011-05-01

    Full Text Available In October 2009, the European Commission published"nguidelines (Radiation Protection No. 159 on Clinical"nAudit for medical radiology-including Diagnostic"nRadiology, Nuclear Medicine and Radiotherapy-in"norder to improve the implementation of article 6.4 of"nthe Council Directive 97/43/ EURATOM, on health"nprotection of individuals against the dangers of ionizing"nradiation in relation to medical exposure. In article 6.4"nit is stated that "Clinical Audits shall be carried out"nin accordance with national procedures". However,"nthere is a wide variation in the understanding and"nimplementation of Clinical Audit in Europe and"nworldwide. The interpretation of the term audit and"nits differentiation from regulation, quality assurance,"naccreditation and research also differs across Europe."nIn January 2010, the Audit & Standards Subcommittee"nof the European Society of Radiology (ESR published"na document on the ESR perspective on Clinical Audit"nin an effort to define the scope of Clinical Audit in a"nway applicable across the European member states and"nradiological organizations."nThe aim of the presentation is to provide a"ncomprehensive outline of ESR perspective on the"naudit process for clinical radiologists and clinical"nradiology departments. The philosophy discussed is"nequally appropriate for interventional and diagnostic"nradiologists.

  10. Computer analysis of ESR spectra

    Author. Isotropic ESR spectra often display complicated patterns which are difficult to analyze for their hyperfine splitting constants (HSC). To simplify the analysis, we have written a program suitable for PC's for sufficiently iterating simulations of isotropic ESR spectra and determining the simulation which fits the experimental spectra. Chapter one gives a brief introduction to the theory of electron spin resonance (ESR). In chapter two the main concepts of the program are presented. Auto simulate is the main algorithm. It calculates the entire field of valid simulations to ensure that the solution set contains all parameter combinations which produce satisfactory spectra. Auto simulate requires prior knowledge of the HSCs and other parameters needed for the simulation such as the line width, the spectrum width, and the number of magnetic nuclei. Proton Coupling Constant Extraction (PCCE) and autocorrelation are two methods complementing each other to determine the HSCs. Another iterative method based on a systematic application of Monte Carlo method can be applied to generate more accurate values of the line width. In chapter three, the spectra of Naphthalene, Tetracene, Indigo, Ox-indigo semi quinone, thio-indigo and 2,2'-dipyridyl-Na complex free radicals are analyzed. The results are compared to the literature value, good agreement is obtained for different resolution and noise to signal ratios. In the last chapter a print out of the program is presented. The programming language used is Microsoft QuickBASIC version 7.1

  11. ESR Signal Fading of PTFE/ESR Dosimetry

    At present, there are twenty operational nuclear power plants(NPPs) in Korea. Aging in these NPPs must be therefore effectively managed to ensure the availability of functions throughout the plant service life. In general, for estimation of the absorbed dose, alanine/ESR dosimeters were used. We are also estimating the dose quantity of cables and equipment position in the NPP using alanine/ESR dosimeters as a method of calculating aging effect by heat and radiation. But there are some problems that analyzing high dose position by only single dosimeter. So, we introduced new dosimeter, polytetrafluoroethylene (PTFE). Most of the estimated dose values inside the nuclear power plant were below almost 10Gy, but some dosimeters were estimated above 1kGy for about one or two fuel cycle. PTFE was useful in high precision high dose dosimetry. We founded appropriate parameter for measuring dose quantity and made dose-response curve. In this study, we obtained measurement precision of PTFE, and measured signal fading, so confirmed possibility of PTFE as additive dosimeter

  12. ESR spectroscopic examinations on bones and fishbones

    Electron Spin Resonance (ESR) spectroscopy can be used for the identification of irradiated meat and fish by detecting radiation induced radicals in the ESR-spectra of bones or fishbones. The method was tested in several co-trials with chicken, beef, pork, trout and sardine. In all tests an identification of irradiated samples was possible. The results of the ESR-measurements are good enough to establish this method in the collection of official methods according to paragraph 35 LMBG. The measurements of the ESR-signal heights gives a rough estimation of the applied doses. In this article two different methods for dose estimation are discussed. ESR spectroscopy can be used not only for bones but has also been tested as a detection method for other irradiated food-stuffs like fresh or dried fuits and nuts. (orig.)

  13. ESR dating of tooth enamel samples

    Five tooth samples from the palaeoanthropological site of Jinniushan were dated with both electron-spin-resonance (ESR) and uranium-series techniques. The ESR age of about 230 ka is in good agreement with the U-series dating result, which confirms the hypothesis of possible coexistence of Homo erect us and Homo sapiens in China. Problems in ESR dating are discussed such as: 1) inappropriate of simple exponential extrapolation for accumulated dose determination; 2)experimental measurement of alpha detection efficiency and radon emanation and 3)selection of U-uptake model

  14. ESR dating of pottery: a trial

    An attempt of electron spin resonance (ESR) dating of pottery is described using natural radiation defects in quartz grains. Fragments of a neolithic ''Trichterbecher'', previously dated by thermoluminescence (TL), were used. Although various radiation induced centres were identified, only the aluminium centre was useful for dating. The annual dose rate was calculated for a grain distribution from 0.1 to 1 mm, using external as well as internal components. The TL and ESR ages of (4720 ± 300)a and (4976 ± 800)a [(4589 ± 900)a], respectively, are in agreement; however, the uncertainty range in case of the ESR experiment is much larger. (Author)

  15. Analysis of relaxation times of radicals in irradiated black pepper using pulse-ESR and CW-ESR

    We attempted measurement of radicals in irradiated black pepper using pulse-ESR and CW-ESR. Relaxation times (T1, T2) of radicals in black pepper were measured using pulse-ESR. T1 and T2 were also calculated theoretical analysis using CW-ESR parameter. We succeeded in measurement of the field swept echo of irradiated black pepper using pulse-ESR. Pulse-ESR and CW-ESR were able to calculate T1 and T2. T1 values were showed no dose dependence. T2 values showed increase according to irradiation. We revealed that T1 and T2 from pulse-ESR and CW-ESR were changed similarly before and after irradiation. (author)

  16. ESR identification of irradiated foodstuffs: LARQUA research

    As electron spin resonance (ESR) spectroscopy is the leading method for identification of irradiated foodstuffs, meat and fish bones, fruit and relative products (of vegetable origin), sea-food etc. were studied. In order to prepare a large co-trial on ESR identification of irradiation of irradiated foodstuffs, experiments were carried out at LARQUA, especially on fruits and vegetables. The radicals induced in the fruit pulp are not stable because the water content of fruit is generally high, but ESR can be used with dried fruit or dry components such as achenes, pips or stones. Different responses are observed, depending on the fruit. In ''sugatype'' fruits (papaya, dried grapes), an ESR multicomponent signal is radio-induced, but the non-irradiated fruit presents no ESR signal or a single-line, while in ''cellulose type'' fruits (pistachio nut, berries), a triplet is induced. But a six line signal due to Mn2+ and a central single line may also be present both in irradiated and non-irradiated samples. In the case of aromatic herbs, the proposed official CEN protocol for irradiated food containing cellulose was used. (author)

  17. ESR dosimetry using quartz grains in bricks

    Present studies indicate that ESR dosimetry of A-bomb can be done using the signal at g=2.0008 for quartz grains in bricks collected at distances of about less than 1 - 2 km from the epicenter of Hiroshima and Nagasaki. One can estimate that ESR dating of archaeological samples of a few thousands years before present is also possible using quartz grains of ancient ceramics. As the sensitivity of ESR spectrometer is improved, the minimum number of the detectable spins will be further reduced. The minimum detectable dose of 1.6 ± 0.6 Gy and the detectable age of a few thousand years would be reduced by one or two orders of the magnitude. This indicates that ESR dosimetry can replace TLD because of the advantage of repeated measurements of a sample. If a few dose can be measured, ESR dating based on dosimetry will go into the field from geology to archaeology and probably into history and forensic science. (author)

  18. Transient melting of an ESR electrode

    Kharicha, A.; Karimi-Sibaki, E.; Bohacek, J.; Wu, M.; Ludwig, A.

    2016-07-01

    Melting parameters of ESR process such as melt rate and immersion depth of electrode are of great importance. In this paper, a dynamic mesh based simulation framework is proposed to model melt rate and shape of electrode during the ESR process. Coupling interactions between turbulent flow, temperature, and electromagnetic fields are fully considered. The model is computationally efficient, and enables us to directly calculate melting parameters. Furthermore, dynamic change of electrode shape by melting can be captured. It is necessary to control the feeding velocity of electrode due to melting instabilities in the ESR process. As such, a numerical control is implemented based on the immersion depth of electrode to achieve the steady state in the simulation. Furthermore, the modeling result is evaluated against an experiment.

  19. Identification of irradiated pepper by ESR measurement

    The possibility of using electron spin resonance (ESR) for identification of irradiated black and white pepper was examined. The ESR spectra induced by irradiation with 10 kGy are clearly distinguishable from that of unirradiated samples. The intensity of signal induced by irradiation was markedly reduced during 2 weeks storage but it was slowly reduced on further storage. The difference of intensity between the irradiated and unirradiated samples can be distinguished after 13 weeks storage. In this experiment, ground black pepper, ground white pepper and whole white pepper can be identified after 13 weeks. On the other hand, whole black pepper cannot be identified after 8 weeks because of the variation of values. It suggests that the suitable method for sample preparation such as separation of pellicle of whole black pepper is required before ESR measurement. (author)

  20. The development of high sensitive electron spin resonance (ESR) dosimeter

    This report introduces light metal ion-organic compound such as lactates, acetate and phosphate to a series of new ESR dosimeter materials. Their ESR spectra and sensitivities to radiation dose are obtained. (author)

  1. ESR Measurements on the Polymerization of Liquid Selenium

    Koningsberger, D.C.; Wolput, J.H.M.C. van; Rieter, P.C.U.

    1971-01-01

    In an earlier communication ESR measurements on de-oxygenized selenium were announced. The present paper reports on further ESR measurements on liquid de-oxygenized selenium carried out in a temperature interval 240}o{C < T < 420}o{C. The g-value of the ESR signal is found to be 2.03 +/- 0.02. The t

  2. Radiation dosimetry by ESR in bone

    Gallegos, R. (Universidad de San Agustin de Arequipa (Peru)); Marticorena, B. (Instituto Peruano de Energia Nuclear, Lima)

    1983-05-01

    The absorption speed in bovine bone samples irradiated with a /sup 90/Sr ..beta..-source of 45 mCi is studied with ESR. The signal changes linearly with the absorbed quantity of radiation to a maximum dose of 1.5 x 10/sup 6/ rads. This positive result allows to foresee the use of bone as a radiation dosimeter.

  3. Progress in ESR dating of fossils

    In this review the progress of ESR dating is briefly described together with its historical development. Examples of fossil dating include shells and corals in geological sediments, fossil bones and teeth in anthropology and fossil woods in geology. The total dose of natural radiation (TD) equivalent to the archaeological dose in TL dating was obtained by the additive dose method. Initially, the TDs were plotted against the known ages; using the apparent annual dose-rate thus obtained gives the ESR age within a factor of 2 or 3 for a fossil. Precise assessment of the radiation environment was made later taking the disequilibrium of uranium series disintegration into account. ESR ages of corals agreed well with those obtained by radiocarbon and uranium-thorium methods. The time-independent accumulation rate or a linear accumulation or uranium was adopted as a first sensible model for the opensystem fossil bones: the relation between the TD and the age explains the ages of anthropologically important bones. Lastly, geological assessment of fossil woods was made by ESR based on the organic radicals and electron traps in the silicified part. (author)

  4. Alanine - ESR dosimetry, feasibility and possible applications

    Alanine ESR dosimetry presents a great interest for quality controls in radiotherapy. This new developed water equivalent alanine dosimeter allows a reproducible dose measurement, by a non-destructive readout technique in a large dose range. In this paper the stability of the dosimeter response has been shown but also its independence with the energy or the dose rate of the absorbed radiation. Through this different studies, one can broaden the application field of alanine / ESR dosimetry especially for in-vivo dosimetry. The results of the experiments and the intra operative treatment, indicate that this kind of dosimetry seems to be a promising technique for in-vivo quality controls in electron beam, γ ray or X ray radiotherapy. (authors)

  5. Electrochemical Aspects of the ESR Process

    Mitchell, Alec

    2016-07-01

    Current passage in the ESR process is accomplished by at least two Faradaic reaction systems, one at the electrode/slag interface and another at the slag/ingot interface. The nature of these reactions has been investigated and is reported to be a function of the alloy composition, current density and slag composition. In this report, data generated from both DC and line- frequency AC ESR operations is used to relate laboratory investigations on these reactions to results obtained in industrial practice. The operating reaction in the line frequency AC melting of simple alloy steels is found to be principally the reversible anodic oxidation of iron (Fe/Fe2+). In the equivalent DC process there is in addition the cathodic deposition of aluminium, resulting in the formation of substantial amounts of D-type alumina inclusions in the ingot. The Faradaic reactions involve energy exchange which should be taken into account in the process energy balance. They also are likely to change the interface physical characteristics such as interfacial tension. The data is extended to the case of low frequency ESR furnaces in which it is found that the extent of the reactions is strongly dependent on current density. It is concluded that the presence of Faradaic reactions in low frequency furnaces is unlikely to lead to quality problems in the alloys and applications for which these processes are used. This conclusion appears to be supported by industrial practice and leads to a further conclusion that low frequency practices in large ESR furnaces could potentially be replaced by simpler DC systems.

  6. ESR dating at Mezmaiskaya Cave, Russia

    Skinner, A.R. [Department of Chemistry, Williams College, Williamstown, MA, 01267 (United States)]. E-mail: anne.r.skinner@williams.edu; Blackwell, B.A.B. [Department of Chemistry, Williams College, Williamstown, MA, 01267 (United States); Martin, Sara [Department of Chemistry, Williams College, Williamstown, MA, 01267 (United States); Ortega, A. [RFK Science Research Institute, Flushing, NY, 11366 (United States); Blickstein, J.I.B. [RFK Science Research Institute, Flushing, NY, 11366 (United States); Golovanova, L.V. [Laboratory of Prehistory, St. Petersburg (Russian Federation); Doronichev, V.B. [Laboratory of Prehistory, St. Petersburg (Russian Federation)

    2005-02-01

    Mezmaiskaya Cave has yielded more than 10,000 artifacts, thousands of very well preserved faunal remains, and hominin remains, found in seven Middle Paleolithic (Mousterian) and three Upper Paleolithic levels. A complete Neanderthal infant skeleton was preserved in anatomical juxtaposition lying on a large limestone block, overlain by the earliest Mousterian layer, Layer 3. Twenty-four skull fragments from a 1-2 year-old Neanderthal infant, showing post-mortem deformation, occurred in a pit originating in the Mousterian Layer 2 and penetrating into underlying layers 2A and 2B(1). Bone from Layer 2A was dated by AMS {sup 14}C at 35.8-36.3{+-}0.5 kyr BP. Direct dating of Neanderthal bone from Layer 3 gave an age of 29 kyr, but that is now considered to be due to contamination by modern carbon. Fourteen large mammal teeth from Layers 2 through 3 have been dated by standard electron spin resonance (ESR). Low U concentrations in both the enamel and dentine ensure that ESR ages do not depend significantly on the U uptake model, but do depend strongly on the sedimentary dose rates. Assuming a sedimentary water concentration equal to 20 wt%, ESR ages for the Mousterian layers range from 36.2 to 73.0{+-}5.0 ka.

  7. ESR identification of gamma-irradiated albendazole

    Çolak, Seyda

    2010-01-01

    The use of ionizing radiation for sterilization of pharmaceuticals is a well-established technology. In the present work, the spectroscopic and kinetic features of the radicals induced in gamma-irradiated solid albendazole samples is investigated at different temperatures in the dose range of 3-34 kGy by electron spin resonance (ESR) spectroscopy. Irradiation with gamma radiation produced two different radical species in albendazole. They were fairly stable at room temperature but relatively unstable above room temperature, giving rise to an unresolved ESR spectrum consisting of three resonance peaks centered at g=2.0057. Decay activation energies of the contributing radical species were calculated to be 47.8 (±13.5) and 50.5 (±9.7) kJ/mol using the signal intensity decay data derived from annealing studies performed at high temperatures. A linear function of the applied dose was found to best describe the experimental dose-response data. Albendazole does not present the characteristics of good dosimetric materials. However, the discrimination of irradiated albendazole from its unirradiated form was possible even 6 months after storage in normal conditions. Based on these findings, it is concluded that albendazole and albendazole-containing drugs can be safely sterilized by gamma radiation and that ESR spectroscopy could be successfully used as a potential technique for monitoring their radiosterilization.

  8. ESR analysis of irradiated frogs' legs and fishes

    Electron spin resonance (ESR) spectral analysis of different parts (bones, scales, jaw, etc.) from ionized (irradiated) frozen frogs' legs and fishes (brown trout and sardine) were recorded. There is always present, after treatment, a signal due to the irradiation. ESR and ENDOR experiments lead us to assign it to h1 centers from hydroxyapatite, as in the case of other irradiated meat bones. The use of ESR to prove whether one of these foods has been irradiated or not is discussed. (author)

  9. Correlation of ESR with lyoluminescence dosimetry using some sugars

    Most applications involving ESR dosimetry currently center on aminoacids because of their relative tissue equivalence. Sugars, however, in addition to possessing high sensitivity and stability in their ESR and LL responses, are widely available as chemical reagents and as commercial sugar. In the present study, dosimetric characteristics of mannose, trehalose, sucrose and commercial sugar obtained by means of ESR and LL techniques are reported. Doses measured by both methods showed agreement within 5%. (author)

  10. ESR study of irradiated uranyl salts

    Results of ESR measurements on gamma-irradiated single crystals of ammonium uranyl nitrate and potassium uranyl nitrate are reported. In ammonium uranyl nitrate, the observed radical is found to have a similar behaviour to irradiated rubidium uranyl nitrate. However, a pair of satellites to the main lines have been observed and they have been interpreted as the simultaneous proton spin-flips. In the case of potassium uranyl nitrate, the observed radicals are also assigned to NO3. The directions of the principal axes of the g-tensor and their values are reported. These results support theoretical predictions based on the electronic structure. (K.B.)

  11. ESR dating of teeth from Brazilian megafauna

    Oliveira, L. C.; Kinoshita, A.; Barreto, A. M. F.; Figueiredo, A. M.; Silva, J. L. L.; Baffa, O.

    2010-11-01

    The study of radiation defects created in biomaterials, such as bone and teeth, can be used in dating with importance to palaeontology and archaeology. Two Stegomastodon teeth (AL1 and AL2) from north-eastern Brazilian megafauna were studied by electron spin resonance (ESR) spectroscopy. The samples were collected in Fazenda Ovo da Ema, (913349 / 3714965) UTM, Alagoas state, Brazil. The dating of these samples can contribute to the better knowledge of megafauna presence in this region as well as to the events associated to the extinction of these species.

  12. ESR signals in natural barite: an application to ESR dosimetry and dating

    Barite is the natural BaSo4. A large crystal of barite was collected from El-Gedida sedimentary Iron-ore Mine, Al-Bahariya Oasis, where it is one of the most common gangue minerals in the ore. Another barite sample was collected from Gabal El-Hudi, east of Aswan, from a barite vein associated with metamorphic rocks where barite is colorless and produced economically. The two samples were subjected to ESR studies. The (ESR) spectrum of Al-Bahariya barite is characterized by ESR signals due to the electron center SO3- [g=2.0028, 2.0001 and 2.0036] and the hole-center O23- [g=2.0191, 2.0127 and 2.0103]. On the other hand, the ESR spectrum of El-Hudi barite shows the existence of both electron centers SO3- and SO2- [g=2.010, 2.007 and 2.030] and the hole center O23-, as well as the electron center CO2- (g=1.9973). The presence of the CO2- center in El-Hudi barite was not previously reported and can be attributed to the presence of carbonate impurities. The barite ESR signals SO3-(g=2.0028) were optimized, tested for linear response to artificial γ-irradiation in the dose range (6-320 Gy) and found to be stable up to 400 oC. Significant differences are observed in the ESR characteristics of the studied ba rites where the total doses (TD) are 911.4 Gy and 60 Gy for Al-Bahariya and El-Hudi barite respectively, but the saturation doses (SD) are 6.6 kGy and 26 kGy respectively. Using the annual dose (D) of 0.3 mGy due to cosmic rays; the Al-Bahariya barite yielded an age of 3.00 Ma (g=2.0028) while El-Hudi barite age is 200 ka (g=2.0028). The ESR age of Al-Bahariya barite (3.00 Ma) suggested that the last recrystallization event causing the formation of the large barite crystals occurred during the Pliocene. El-Hudi barite ESR age (200 ka) suggests its correlation and formation of barite during the humid climatic O2- isotopes stage 7, documented in the Eastern Desert of Egypt. Furthermore, Al-Bahariya barite meets the criteria suggested for new ESR dosimetric materials in

  13. ESR dosimetric properties of modern coral reef

    Modern coral reef samples from Egypt were irradiated with 60Coγ-rays to study radicals for dosimetric materials with electron spin resonance (ESR). The ESR spectrum for the radical species in unirradiated coral is characterized by four signals with spectroscopic splitting factors of g=2.0056, 2.0030, 2.0006 and 1.997. The signal at g=2.0006±0.0005 is ascribed to free rotation CO2- radicals and used as a dosimetric one. The response to γ-ray doses ranging from 5 to 103 Gy and the thermal stability has been studied. The number of free radicals per 100 eV (G-value) was found to be 0.45 ± 0.1 and 0.9 ± 0.18 for coral and alanine, respectively. The lifetime of radicals and the activation energy were estimated from Arrhenius plots to be approximately 8 x 105 ± 1.6 x 105 years, and 1.12 eV, respectively

  14. ESR study on carboxymethyl chitosan radicals in an aqueous solution

    Saiki, Seiichi, E-mail: saiki.seiichi@jaea.go.j [Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Nagasawa, Naotsugu; Hiroki, Akihiro; Morishita, Norio; Tamada, Masao [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Muroya, Yusa; Kudo, Hisaaki [Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Katsumura, Yosuke [Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1195 (Japan)

    2010-03-15

    Carboxymethyl chitosan (CMCTS) at a highly concentrated aqueous solution forms hydrogel by ionizing irradiation. To study on radiation-induced reaction mechanism of CMCTS in an aqueous solution, CMCTS radicals formed by reactions with OH radical were observed by ESR method. As a result of ESR spectral analysis, CMCTS radicals were identified as radicals on carboxymethyl groups.

  15. Dosimetry by ESR spectroscopy of alanine

    Dosimetry based on electron spin resonance analysis of radiation-induced free radicals in amino acids (e.g. L-alanine) is relevant to biological dosimetry applications. Typical features are a wide dose range covering more than 5 decades (1-105Gy), energy independent response for photons above 100 keV, long-term stability of the ESR signal, and fast straightforward readout technique. Typical dosimeter samples, consisting of small pellets of microcrystalline amino acids in paraffin, are rugged, non-toxic, and insensitive to surface contaminations. Moreover, they are prepared homogeneously and inexpensively in large batches and can be evaluated repeatedly and supply archival dosimetry data. They have proven to be highly useful in various applications of radiation processing and sterilization dosimetry, food irradiation, quality control, radiation dosimetry, radiation therapy measurements, and as a reference system for dosimetry mailing intercomparisons. (author)

  16. ESR dosimetry for atomic bomb survivors and radiologic technologists

    Tatsumi-Miyajima, Junko

    1987-06-01

    An individual absorbed dose for atomic bomb (A-bomb) survivors and radiologic technologists has been estimated using a new personal dosimetry. This dosimetry is based on the electron spin resonance (ESR) spectroscopy of the CO 33- radicals, which are produced in their teeth by radiation. Measurements were carried out to study the characteristics of the dosimetry; the ESR signals of the CO 33- radicals were stable and increased linearly with the radiation dose. In the evaluation of the absorbed dose, the ESR signals were considered to be a function of photon energy. The absorbed doses in ten cases of A-bomb victims and eight cases of radiologic technologists were determined. For A-bomb survivors, the adsorbed doses, which were estimated using the ESR dosimetry, were consistent with the ones obtained using the calculations of the tissue dose in air of A-bomb, and also with the ones obtained using the chromosome measurements. For radiologic technologists, the absorbed doses, which were estimated using the ESR dosimetry, agreed with the ones calculated using the information on the occupational history and conditions. The advantages of this method are that the absorbed dose can be directly estimated by measuring the ESR signals obtained from the teeth of persons, who are exposed to radiation. Therefore, the ESR dosimetry is useful to estimate the accidental exposure and the long term cumulative dose.

  17. Retrospective ESR dosimetry for persons chronically exposed to ionizing radiation

    Objective: To establish an electron spin resonance (ESR) method to estimate the dose of persons chronically exposed to ionizing radiation. Methods: ESR method was used to detect the ESR signal intensities of tooth enamel samples from two persons chronically exposed to ionizing radiation. The external calibration curve method and the additive dose method were used to reconstruct the irradiation doses of those teeth in order to find whether it is feasible to estimate the chronic dose by enamel ESR. And the effects of radiation energy on the ESR signal intensities were also observed. Results: The estimated doses of two teeth from each person were similar using two methods. Compared 1.25 MeV with 6 MeV X rays, the regression coefficients of the calibration curve were similar, and the doses estimated after combined irradiation were the same as the actually exposed doses. Conclusion: Reconstruction of dose for persons chronically exposed to radiation can be achieved using tooth enamel ESR measurement. The radiation energy, between 1.25 MeV and 6 MeV has little effect on tooth enamel ESR measurement

  18. Radicals in DNA as seen by ESR spectroscopy

    This is a review of ESR studies, mainly of DNA systems, after exposure to ionising radiation at low temperatures. Under this conditions 'direct' damage is of major significance, and ESR evidence for the concept of the initial formation of electron-gain and electron-loss centers localised within DNA bases, and deeply trapped by proton-gain and loss, will be discussed. It is stressed that 'negative' evidence, showing that various phosphate and sugar centred radicals are not detected, is of major importance since the ESR 'fingerprints' of base-radicals are relatively ill defined. (author)

  19. Use of sugars and hair for ESR emergency dosimetry

    ESR spectrometry of sugars and biological samples is being evaluated for emergency personnel dosimetry. Sugars are near tissue-equivalent, universally available in pure form and produce a simple, reproducible, low background signal. Of the sugars tested, sucrose and dextrose are the most sensitive and the ESR signals are proportional to X- or γ-ray doses over the range of 0.5-10 Gy. There is little dependence on radiation energy or dose-rate, and the ESR signals remain stable for long periods post-irradiation. Human hair samples show considerable variability and signal complexity creating difficulties in dose assessment. (author)

  20. ESR, electrochemical and reactivity studies of antitrypanosomal palladium thiosemicarbazone complexes

    Otero, Lucía; Folch, Christian; Barriga, Germán; Rigol, Carolina; Opazo, Lucia; Vieites, Marisol; Gambino, Dinorah; Cerecetto, Hugo; Norambuena, Ester; Olea-Azar, Claudio

    2008-08-01

    Cyclic voltammetry (CV) and electron spin resonance (ESR) techniques were used in the investigation of novel palladium complexes with bioactive thiosemicarbazones derived from 5-nitrofurane or 5-nitrofurylacroleine. Sixteen palladium complexes grouped in two series of the formula [PdCl 2HL] or [PdL 2] were studied. ESR spectra of the free radicals obtained by electrolytic reduction were characterized and analyzed. The ESR spectra showed two different hyperfine patterns. The stoichiometry of the complexes does not seem to affect significantly the hyperfine constants however we observed great differences between 5-nitrofurane and 5-nitrofurylacroleine derivatives. The scavenger properties of this family of compounds were lower than Trolox.

  1. Assessment of the lower ESR dating range in Greek speleothems

    Pilot ESR dating studies on geologically young calcitic sinters were carried out, aiming at assessment of the lower ESR dating range in characteristic Greek speleoenvironments. Five stalactites were dated, coming from an ancient mining gallery, idle for the last 2,500 years, found on Siphnos island (Aegean). The calculated ages range between 1,7-2,0 ka. Medium to low measured external dose rates (aprox. 900 μGy/a) and very low measured radioelement concentration in samples are very usual in the Mediterranean environments. The study concludes that ESR dating of speleothems younger than two millenia is practically unattainable. Some geoarchaeological implications of the obtained ages are discussed. (author)

  2. Study of detection of irradiated dried fruits by ESR spectroscopy

    We focus on dried fruits containing crystalline sucrose chiefly, and study a method for identification of sucrose-radicals in ESR spectra of irradiated dried fruits. We evaluated g-values and widths of ESR signals of irradiated dried fruits and sucrose respectively. The result showed it might be possible to identify sucrose-radicals by g-values and widths. We tried the establishment of criteria for the judgment that the sample has been irradiated. As a result, criteria may be established by normalized peak height of ESR signals. The peak height can be normalized by using standard irradiated alanine pellets. (author)

  3. Ribavirin restores ESR1 gene expression and tamoxifen sensitivity in ESR1 negative breast cancer cell lines

    Sappok Anne

    2011-12-01

    Full Text Available Abstract Tumor growth is estrogen independent in approximately one-third of all breast cancers, which makes these patients unresponsive to hormonal treatment. This unresponsiveness to hormonal treatment may be explained through the absence of the estrogen receptor alpha (ESR1. The ESR1 gene re-expression through epigenetic modulators such as DNA methyltransferase inhibitors and/or histone deacetylase inhibitors restores tamoxifen sensitivity in ESR1 negative breast cancer cell lines and opens new treatment horizons in patients who were previously associated with a poor prognosis. In the study presented herein, we tested the ability of ribavirin, which shares some structural similarities with the DNA-methyltransferase inhibitor 5-azacytidine and which is widely known as an anti-viral agent in the treatment of hepatitis C, to restore ESR1 gene re-expression in ESR1 negative breast cancer cell lines. In our study we identified ribavirin to restore ESR1 gene re-expression alone and even more in combination with suberoylanilide hydroxamic acid (SAHA - up to 276 fold induction. Ribavirin and analogs could pave the way to novel translational research projects that aim to restore ESR1 gene re-expression and thus the susceptibility to tamoxifen-based endocrine treatment strategies.

  4. Influences of sample preparations on dentine ESR signals

    The work is to study influences of sample preparations on dentine ESR (electron spin resonance) signals, in order to use dentine samples for dose reconstruction, which has been performed with enamel samples. The dentine and enamel samples were collected from non-irradiated adult teeth and prepared by mechanical or mechanical plus chemical methods. The samples were scanned by an ESR spectrometer before and after their irradiation by 60Co γ-rays. The sensitivities of ESR signals of dentine and enamel samples to irradiation dose differed significantly among different sample preparation methods. The results show that dentine samples mechanically and chemically prepared have good enough ESR response to low dose γ-ray irradiations, and it is possible to use the dentine samples for dose reconstruction, as a substitution to enamel samples when they are short of supply. (authors)

  5. ESR STUDY OF PLASMA-TREATED POLYTETRAFLUOROETHYLENE FILMS

    ZHOU Maotang; WANG Shicai; LIU Guizhen; CHEN Jie

    1990-01-01

    The plasma treatment of polytetrafluoroethylene (PTFE) films was carried out in a capacitively coupled reactor with external electrodes. The free radicals generated in the process of treatment were detected by ESR techniques. The ESR spectra tended to indicate that the free radicals of the plasma-treated PTFE film sample were turned into peroxy radicals on exposure to air. The extrema separation (W) of the ESR spectrum of the peroxy radical increased with the lowering temperature and underwent a sudden change within the temperature range of 170 to 190K. The ESR spectrum observed at 77K was quite different from that observed at room temperature. Finally, the effects of treatment time, input power and system pressure on radical concentration of the treated samples were studied. The attenuation of the peroxy radical at room temperature was also investigated.

  6. Irradiation detection of coffee mate by electron spin resonance (ESR)

    Un-irradiated coffee mate samples do not exhibit any ESR signal. However, the samples exposed to UV and gamma radiation exhibit an ESR singlet and a large unresolved ESR signal, respectively. The dose-response curves of the samples exposed to UV and gamma radiations were found to be described well by an exponential and linear functions, respectively. Variable temperature and fading studies at room temperature showed that the radiation-induced radicals in coffee mate sample are very sensitive to temperature. The discrimination between un-irradiated and irradiated coffee mate samples can be done just comparing their ESR spectra. However, determination of the radiation dose received by the sample cannot be possible because of the fast decay of signal intensity at room temperature.

  7. Analysis of radicals induced in irradiated cereal flour using ESR

    Using electron spin resonance (ESR) spectroscopy, we revealed radicals induced in cereal flour irradiated with gamma-ray or electron beam. Sample was wheat and rice. We detected a broad singlet signal at g = 2.0. It consists of a singlet signal and a triplet signal. It suggested that the singlet signal is originated from organic free radicals and the triplet signal is from 14N. There were no differences of ESR spectra between irradiated wheat flour and rice flour. The signal intensity of radiation induced radical was tend to increase following with the increase of radiation dose level. After radiation treatment, relaxation time of radiation induced radical was changed during storage. T1 was decreased and T2 was increased. In this study, the relaxation time is calculated using the parameters obtained from the ESR signal. It is necessary to analyze the relaxation time directly with pulsed ESR spectroscopy in future. (author)

  8. Irradiation detection of coffee mate by electron spin resonance (ESR)

    Ozsayin, Fulya [Physics Engineering Department, Hacettepe University, 06800 Ankara (Turkey); Polat, Mustafa, E-mail: polat@hacettepe.edu.t [Physics Engineering Department, Hacettepe University, 06800 Ankara (Turkey)

    2011-06-15

    Un-irradiated coffee mate samples do not exhibit any ESR signal. However, the samples exposed to UV and gamma radiation exhibit an ESR singlet and a large unresolved ESR signal, respectively. The dose-response curves of the samples exposed to UV and gamma radiations were found to be described well by an exponential and linear functions, respectively. Variable temperature and fading studies at room temperature showed that the radiation-induced radicals in coffee mate sample are very sensitive to temperature. The discrimination between un-irradiated and irradiated coffee mate samples can be done just comparing their ESR spectra. However, determination of the radiation dose received by the sample cannot be possible because of the fast decay of signal intensity at room temperature.

  9. Study on identification of irradiated food containing cellulose by ESR

    The fast development and application of food irradiation technology signify the necessity and urgency to research on effective detection method for irradiated food. In this paper, we report a preliminary study in this area with dried chili powder, peanuts and strawberry seeds. The food samples were irradiated to 0.5, 1.0, 3.0, 5.0 and 10.0 kGy by 60Co gamma rays. The relation between ESR intensity and irradiation dose, and correlation R2, were studied. The results showed that the ESR signal intensity is positively related with the dose. ESR intensity of the strawberry increased the slowest with the dose, and the chili powder had the most accurate calculation. Accurate dose-effect curves, however, require repeating tests and further studies are needed to verify the ESR results. (authors)

  10. ESR studies of the magnetism of Ru-1212

    We have studied, by ESR, the systems of Ru-1212 over the temperature range 100-300 K, in the normal and magnetic phases. We have found that the ferromagnetic line appears at a temperature higher than the magnetic ordering temperature as determined by neutron diffraction. We also show a correlation between the temperature dependence of the intensity and width of the ESR lines, the intensity of magnetic absorption lines and the DC magnetization measurements

  11. Lactose and ''tris'' lyoluminescence dosimetry systems and ESR correlation studies

    Lyoluminescence (LL) dosimeters have been developed using lactose monohydrate (disaccharide) and tris(hydroxymethyl)aminomethane (''Tris'') systems and attempts have been made to understand the LL mechanism through ESR correlation studies. Tris LL dosimeter has a γ-ray sensitivity with a linear response in the absorbed-dose range 0.05-200 Gy (5-2 x 104rad), while the lactose response extends to a higher range from 1 to 104 Gy (102-106 rad). The LL output of lactose and Tris did not show any appreciable decay for a period of 6 months after irradiation. ESR measurements show that free-radical concentration in both the systems increases with γ-ray dose in the range 102-105 Gy. The minimum dose required to measure the radiation-induced ESR signal for Tris is ∼ 500 Gy, the dose at which the LL output saturates, while lactose shows a radiation-induced ESR signal right at the minimum dose where LL could be detected. The estimated spin density on the radical carbon atom is 0.7. ESR signal stabilities of lactose and Tris were also studied. Lactose did not show any appreciable ESR decay for a period of 3 months after irradiation, while, for Tris, one of the radicals showed a decay of 45% for the same period. (author)

  12. ESR studies on bleached sedimentary quartz

    Walther, R.; Zilles, D.

    Some ESR signals in quartz are reported to be bleachable by sunlight and so they promise to be useful for dating sediments (Grün, 1989). The Ge signal in quartz is the only one that shows bleaching effects with UV light in short time scales (hours). Therefore we used quartz samples from the sites of Mauer ( 'Homo erectus heidelbergensis'), samples from a borehole in the Neckar valley ('Entensee', Ladenburg near Heidelberg) and samples from a pegmatite for basic studies on the Ge signal. The results show that with our standard sample preparation procedure for quartz separation (using red light as for TL samples), the natural Ge signal is not detectable, but rises clearly with gamma irradiation. Several experiments for examination of the stability and sensitivity of the Ge centre in quartz were carried out. For comparison with the behaviour of the Ge signal we measured the Al signal as well. Our experiments show that the Al signal is bleachable in long time scales (weeks). The behaviour on bleaching, irradiation and thermal annealing is very complicated, as the Al centre is a hole centre (it possibly interacts with several electron centres in the quartz and so the processes are of higher order).

  13. ESR of ice and environmental assessment

    In the environment of the earth, liquid water exists abundantly, but it cannot be seen in other environment in the solar system. The environment covered with solid water is seen in many celestial bodies, but these ices are not pure water, and contain NH3, SO2, CH4, CO, CO2 and others. Also the existence of solid CO2 on Mars, solid SO2 on Io and solid CH4 on Triton has been known. In many celestial bodies without atmosphere and with ice, it is considered that the ice causes dissociation and ionization due to the effects of ultraviolet ray, solar wind and cosmic γ ray. As the basis of examining these phenomena, the authors made various ices, and studied on the irradiation effect of gamma ray and ultraviolet ray in the laboratory. It became clear by the research using ESR that various kinds of radicals were formed in the ices by the irradiation. The age of the radicals formed in ices means the age of the events that extinguish the radicals occurred on the surfaces of the celestial bodies after ice formation. The problems in the principle of age measurement are the real formation of radicals, the stability of radicals, and the saturation of radical concentration. The research of these problems for H2O and SO2 is reported. (K.I.)

  14. Radiostability of butylated hydroxytoluene (BHT): An ESR study

    Tuner, H.; Korkmaz, M.

    2007-05-01

    In the present work, the effects of gamma radiation on solid butylated hydroxytoluene (BHT), which is used as an antioxidant, were investigated by ESR spectroscopy. While unirradiated BHT presented no ESR signal, irradiated BHT exhibited an ESR spectrum with many resonance maxima and minima spread over a magnetic field range of 12 mT and centered at about g = 2.0026. Weak satellite and central intense resonance lines, likely, originated from radical species of different stabilities and ratios were observed to be responsible from experimental ESR spectrum of gamma irradiated BHT. Studies based on the variations of the observed line intensities and spectrum area under different experimental conditions were carried out and characteristic features of the radical species responsible from experimental ESR spectrum were determined. Mesomeric radical species of different stabilities providing to BHT a G value of 0.25 were believed to be induced in gamma irradiated BHT. While species responsible from weak satellite lines were unstable, the species causing central intense lines were found to be relatively stable. BHT belongs to a class of compounds with low radiosensitivity ( G = 0.25). This feature of BHT enables the feasibility of radiosterilizations of the products containing BHT as antioxidant without very much loss from its antioxidant benefit. BHT has been shown to provide an opportunity in the estimation of applied radiation dose with a reasonable accuracy if an appropriate mathematical function is used to describe experimental dose-response data.

  15. Radiostability of butylated hydroxytoluene (BHT): An ESR study

    Tuner, H. [Department of Physics Engineering, Faculty of Engineering, Hacettepe University, Beytepe, Ankara 06800 (Turkey)]. E-mail: htuner@hacettepe.edu.tr; Korkmaz, M. [Department of Physics Engineering, Faculty of Engineering, Hacettepe University, Beytepe, Ankara 06800 (Turkey)

    2007-05-15

    In the present work, the effects of gamma radiation on solid butylated hydroxytoluene (BHT), which is used as an antioxidant, were investigated by ESR spectroscopy. While unirradiated BHT presented no ESR signal, irradiated BHT exhibited an ESR spectrum with many resonance maxima and minima spread over a magnetic field range of 12 mT and centered at about g = 2.0026. Weak satellite and central intense resonance lines, likely, originated from radical species of different stabilities and ratios were observed to be responsible from experimental ESR spectrum of gamma irradiated BHT. Studies based on the variations of the observed line intensities and spectrum area under different experimental conditions were carried out and characteristic features of the radical species responsible from experimental ESR spectrum were determined. Mesomeric radical species of different stabilities providing to BHT a G value of 0.25 were believed to be induced in gamma irradiated BHT. While species responsible from weak satellite lines were unstable, the species causing central intense lines were found to be relatively stable. BHT belongs to a class of compounds with low radiosensitivity (G = 0.25). This feature of BHT enables the feasibility of radiosterilizations of the products containing BHT as antioxidant without very much loss from its antioxidant benefit. BHT has been shown to provide an opportunity in the estimation of applied radiation dose with a reasonable accuracy if an appropriate mathematical function is used to describe experimental dose-response data.

  16. ESR dosimetry using eggshells and tooth enamel for accidental dosimetry

    The CO2- signal of eggshells showed a good dose linearity and was appropriate in the wide dose range from 1 to 10 kGy, while ESR signal of CO2- in sea and fresh water shells were saturated at a dose od below 10 kGy. The minimum detectable dose and G-value of CO2- in eggshells were estimated 0.3 Gy and 0.28, respectively. The lifetime of CO2- in eggshells could not be determined exactly because of overlapping organic signals, however it is still sufficiently long for practical use as ESR dosimeter materials. Various bird's or reptile's eggshells would be available as natural retrospective ESR dosimeter materials after nuclear accidents. Eggshells will be useful for the food irradiation dosimetry in the dose range of about a few kGy. Tooth enamel is one of the most useful dosimeter materials in public at a accident because of its high sensitivity. ESR dosimetry will replace TLD in near future if the cost of an ESR reader is further reduced . (author)

  17. A rapid detection for irradiated fresh papayas using ESR spectroscopy

    The detections of radicals induced in irradiated both fresh and dried papayas were carried out at liquid nitrogen and room temperature using electron spin resonance (ESR) spectroscopy. Fresh papayas irradiated by the γ-rays were separated into flesh and skin that subjected to the ESR detection. The ESR spectra of the specimen at liquid-nitrogen temperature were observed clearly at a week after the γ-irradiation. Those signals were consisted from main peak at g=2.000 and side peaks at g=2.018 and 1.982. They showed a linear response against the dose. Furthermore, the side peaks from freeze-dried papaya flesh stored at 4degC were observed clearly at two weeks after the γ-irradiation. Those signals also showed the linear dose-response. The detection scheme for irradiated fresh fruits can be done by two stages: 1) A screening test of ESR signals at liquid nitrogen temperature using fresh samples. 2) A room temperature ESR measurement using freeze-dry samples. (author)

  18. Communication Acoustics

    Blauert, Jens

    Communication Acoustics deals with the fundamentals of those areas of acoustics which are related to modern communication technologies. Due to the advent of digital signal processing and recording in acoustics, these areas have enjoyed an enormous upswing during the last 4 decades. The book...... the book a source of valuable information for those who want to improve or refresh their knowledge in the field of communication acoustics - and to work their way deeper into it. Due to its interdisciplinary character Communication Acoustics is bound to attract readers from many different areas, such as......: acoustics, cognitive science, speech science, and communication technology....

  19. Computer enhancement of ESR spectra of magnetite nanoparticles

    Dobosz, B.; Krzyminiewski, R.; Koralewski, M.; Hałupka-Bryl, M.

    2016-06-01

    We present ESR measurements of non-interacting magnetic nanoparticle systems. Temperature and orientational dependence of ESR spectra were measured for Fe3O4 nanoparticle coated by dextran or oleic acid, frozen in different magnetic field. Several parameters describing magnetic properties such as g-factor, line width, the anisotropy constant were calculated and discussed. The ESR spectra of investigated nanoparticles were also subjected to Computer Resolution Enhancement Method (CREM). This procedure allows to separate a narrow line on the background of the broad line, which presence in this type of materials was recognized in the recent literature and have been further discussed in the paper. CREM is a valuable tool for monitoring of changes on the surface of magnetic core of nanoparticles.

  20. Acoustic Neuroma

    An acoustic neuroma is a benign tumor that develops on the nerve that connects the ear to the brain. The tumor ... press against the brain, becoming life-threatening. Acoustic neuroma can be difficult to diagnose, because the symptoms ...

  1. Acoustic Neuroma

    An acoustic neuroma is a benign tumor that develops on the nerve that connects the ear to the brain. ... can press against the brain, becoming life-threatening. Acoustic neuroma can be difficult to diagnose, because the ...

  2. E.S.R. investigations in irradiated polycarbonate

    Electron spin resonance (e.s.r.) spectroscopy is a powerful tool in the investigation of radiation induced defects in dielectric materials, such as polycarbonates. This method allows the identification of defects'nature, their interactions as well as the study of defects kinetic leading to the estimation of the life time or/and of the activation energy for the free radical accumulation/recombination processes. E.s.r. data on polymers irradiated with accelerated ions have revealed that the paramagnetic defects are coupled by severe exchange interactions and that the nature of the free radicals is at variance with the thermal spikes description. Experimental results are given. (Author). 7 refs

  3. Thermal stability of ESR signals in hydrothermal barites

    Thermal stability of the ESR signals from barites in chimneys deposited from hydrothermal vents is investigated using isothermal and isochronal annealing experiments. A combination of first and second order kinetics is required to explain the results. The Arrhenius plots of the decay rate constants give the activation energies of 1.0-1.3 eV. From the estimated decay rate constants at the sea bottom (3 oC), the decay rate of the signal was calculated to be less than 2% for the period of 20 ka, suggesting the applicability of the ESR method for dating barites up to about twenty thousand years.

  4. Thermal stability of ESR signals in hydrothermal barites

    Sato, Fumihiro [Department of Applied Physics, Okayama University of Science, 1-1 Ridai-cho, Kita-ku, Okayama 700-0005 (Japan); Toyoda, Shin, E-mail: toyoda@dap.ous.ac.jp [Department of Applied Physics, Okayama University of Science, 1-1 Ridai-cho, Kita-ku, Okayama 700-0005 (Japan); Banerjee, Debabrata [Department of Applied Physics, Okayama University of Science, 1-1 Ridai-cho, Kita-ku, Okayama 700-0005 (Japan); Planetary Sciences Division, Physical Research Laboratory, Ahmedabad 380009 (India); Ishibashi, Jun-Ichiro [Department of Earth and Planetary Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan)

    2011-09-15

    Thermal stability of the ESR signals from barites in chimneys deposited from hydrothermal vents is investigated using isothermal and isochronal annealing experiments. A combination of first and second order kinetics is required to explain the results. The Arrhenius plots of the decay rate constants give the activation energies of 1.0-1.3 eV. From the estimated decay rate constants at the sea bottom (3 {sup o}C), the decay rate of the signal was calculated to be less than 2% for the period of 20 ka, suggesting the applicability of the ESR method for dating barites up to about twenty thousand years.

  5. ESR of an O3- centre in KCl

    By means of ESR an ozonide molecular O3- ion was detected in x-irradiated KCl. The principal values of the G-tensor (2.0032, 2.0182, 2.0118) are in excellent agreement with the values found in other host lattices and with CNDO calculations performed earlier. All measurements were carried out at liquid-helium temperatures. (author)

  6. Investigation of free radicals in paprika with the ESR method

    Complete text of publication follows. The ESR method is the one of the most successfully applied method among the physical methods for the identification of radiation or ionising treatment of foods. The identification of free radicals having short and long lifetimes is the base of the measurement. The quantitative determination makes possible the determination of the absorbed dose deriving from 60Co radiation treatment. It has to be noted that the treatment of the foods with ionising radiation and other treatments (milling, frying, baking) and the oxidative process result free radicals in paprika samples as a function of absorbed radiation dose (2.5; 5 and 10 kGy) on the different particle size and on storage time. The intensities of the samples given after each of the seven stages of the paprika milling increased till the fifth stage corresponding to the effect of a 2 kGy absorbed dose. After conditioning and increasing the water content by 5-8% the ESR intensity shows significant lowering. This value characterises the ESR intensity of not irradiated sample. As an effect of the irradiation the ESR intensities increased along with the increase of the absorbed dose. The samples having lower particle size are more sensible for the identification of the irradiation. Evaluating the art of the decline we concluded that there are free radicals having short and long shelf lifetimes in paprika samples at the same time

  7. The ESR spectrum of NO2 in the gaseous state

    Schaafsma, T. J.

    1967-01-01

    Existing theory of electron spin rotation spin rotation interaction in a polyatomic free radials was tested by comparing experimental and calculated high field ESR spectra of gaseous NO2. The results of this study suggest that the spin-rotation phenomenon is at least qualitatively understood. but th

  8. Optical and ESR studies of Tris(8-hydroxyquinoline)aluminum

    Tris(8-hydroxyquinoline)aluminum (AlQ) powder has been characterized using photoluminescence and electron spin resonance (ESR). The broad asymmetric excitation band is centered at ∼425 nm, while the emission band centered at ∼505 nm is similar to those reported in films. A significant ESR signal with a linewidth of 10 G and g-value of 2.0038 has been observed in as synthesized AlQ powder at room temperature. The signal at same position is present in AlQ powder as-received from Aldrich, as synthesized AlQ powder, and AlQ powder purified by vacuum sublimation. The appearance of the ESR signal is attributed to organic free radicals. Moreover, exposure of AlQ powder to humid air enhances the ESR signal intensity which increases linearly with exposure duration. This is in agreement with recently proposed degradation mechanism in AlQ based organic light emitting diodes, where degradation was attributed to unstable cationic AlQ species. The discovery of natural free radicals in freshly synthesized AlQ may be useful to prevent the degradation of AlQ and other analogous compounds in organic light emitting diodes (OLEDs)

  9. Detergent powder. Investigation for feasible retrospective dosimetry using ESR technique

    An Electron Spin Resonance (ESR) study of radiation induced free radicals in the commonly used detergent powder (Surf), was conducted to examine its potential application for retrospective/high level dosimetry, including possible dating of the accidents. The radical ions present in the irradiated detergent powder were identified as arising predominantly from sodium tri poly phosphate (Na3P5O10) and sodium sulphate (Na2SO4). The physical mixture of sodium tri poly phosphate and sodium sulphate in 4:1 ratio was found to give an ESR response, similar to that of the detergent powder. These results suggest that the detergent powder can be used as a dosimeter in the 20 Gy to 18 kGy dose range, spanning over 3 orders of magnitude. The second derivative ESR spectra of the detergent powder irradiated to different doses showed that the relative yield of the radicals is independent of irradiation dose. The decay pattern of radicals when followed as a function of post irradiation days, lead to the idea about the contrasting decay characteristics of the radicals. From the ESR signals of the irradiated detergent samples, it is shown that radiation dose can be evaluated and the radiation incident can be dated with an accuracy of ± 10%. (author)

  10. ESR dosimetry of irradiated chicken legs and chicken eggs

    Ionising radiation induces stable free radicals in chicken bones and in the shell of chicken eggs which can be detected, by the electrons spin resonance (ESR) technique, well beyond the shelf-life of the food and can be used for dosimetry. The method usually adopted to evaluate ''a posteriori'' the dose given during the ionising radiation treatment of food, is the dose additive method. To assess the dose, the ESR signal amplitude of the irradiated food (bone or egg shell in the present case) is measured and then the dose-effect relationship is obtained by re-irradiating the sample with some additive doses (usually of 1 kGy). The dose-effect curve is back-extrapolated and the initial given dose determined. At the Istituto Superiore di Sanita (ISS), Rome, Italy, a research programme was approved two years ago aimed to, (1) study new methodological approaches for ESR dose assessment, and (2) analyse the factors which may influence the ESR readout of irradiated chicken bones and chicken egg shells. (author)

  11. ESR study on high Tc superconductor MgB2

    MgB2, a high-Tc superconductor, has been studied by Electron Spin Resonance (ESR) techniques at the temperature range of 6-300 K. Polycrystalline powders consisting of MgB2 and MgB4 phases were diluted and oriented in paraffin by applying an external magnetic field of 15 kG. A very narrow (2.5 G), strong, and isotropic signal that corresponded to almost free electron g-values was observed at all temperatures. Both the signal intensity and line width were observed to exhibit strong temperature dependence. The intensity of the ESR spectra, which corresponds to dc susceptibility, generally obeys the Curie law in this temperature range. However, some critical temperatures (approximately 215, 190, 150, and 39 K) were evident from both intensity and line width curves. While the ESR line is broadened, the signal intensity is drastically decreased just below T=39 K, corresponding to a transition temperature to a superconducting state. The origins of the minor changes both in the intensity and line width curves at other (higher) critical temperatures are not clear yet. In fact, the change at 215 K was observed to be meta-stable. These minor changes might be taken as signs for changes of local crystalline field symmetry around weakly localized conduction electrons or holes, which are the sources of the ESR signal in the MgB2 compound

  12. Edge Stabilized Ribbon (ESR); Stress, Dislocation Density and Electronic Performance

    Sachs, E. M.

    1984-01-01

    The edge stabilized ribbon (ESR) silicon ribbon was grown in widths of 1, 2.2 and 4.0 inches at speeds ranging from .6 to 7 in/min, which result in ribbon thicknesses of 5 to 400 microns. One of the primary problems remaining in ESR growth is that of thermally induced mechanical stresses. This problem is manifested as ribbon with a high degree of residual stress or as ribbon with buckled ribbon. Thermal stresses result in a high dislocation density in the grown material, resulting in compromised electronic performance. Improvements in ribbon flatness were accomplished by modification of the ribbon cooling profile. Ribbon flatness and other experimental observations of ESR ribbon are discussed. Laser scanner measurements show a good correlation between diffusion length and dislocation density which indicates that the high dislocation densities are the primary cause of the poor current performance of ESR materials. Dislocation densities were reduced and improved electronic performance resulted. Laser scanner data on new and old material are presented.

  13. ESR spectrum and structure of BrF6

    The BrF6 radical has been obtained by γ irradiation of a mixture of BrF5 in SF6. The ESR spectrum was obtained and used to confirm the identity of the radical and to obtain hyperfine coupling constants. (AIP)

  14. Electron beam dose measurements with alanine/ESR dosimeter

    When the aminoacid alanine, CH3-CH(NH2)-COOH, is exposed to radiation field, stable free radicals are produced. The predominant paramagnetic specie found at room temperature is the CH3-CH-COOH. Electron Spin Resonance - ESR is a technique used for quantification and analysis of radicals in solid and liquid samples. The evaluation of the amount of produced radicals can be associated with the absorbed dose . The alanine/ESR is an established dosimetry method employed for high doses evaluation, it presents good performance for X-rays, gamma, electrons, and protons radiation detection. The High Doses Dosimetry Laboratory of Ipen developed a dosimetric system based on alanina/ESR that presents good characteristics for use in gamma fields such as: wide dose range from 10 to 105 Gy, low fading, low uncertainty (<5%), no dose rate dependence and non-destructive ESR single readout. The detector is encapsulated in a special polyethylene tube that reduces the humidity problems and improves the mechanical resistance. The IPEN dosimeter was investigated for application in electron beam fields dosimetry

  15. Acoustic cloaking and transformation acoustics

    Chen Huanyang [School of Physical Science and Technology, Soochow University, Suzhou, Jiangsu 215006 (China); Chan, C T, E-mail: kenyon@ust.h, E-mail: phchan@ust.h [Department of Physics and the William Mong Institute of NanoScience and Technology, The Hong Kong University of Science and Technology, Clear Water Bay (Hong Kong)

    2010-03-24

    In this review, we give a brief introduction to the application of the new technique of transformation acoustics, which draws on a correspondence between coordinate transformation and material properties. The technique is formulated for both acoustic waves and linear liquid surface waves. Some interesting conceptual devices can be designed for manipulating acoustic waves. For example, we can design acoustic cloaks that make an object invisible to acoustic waves, and the cloak can either encompass or lie outside the object to be concealed. Transformation acoustics, as an analog of transformation optics, can go beyond invisibility cloaking. As an illustration for manipulating linear liquid surface waves, we show that a liquid wave rotator can be designed and fabricated to rotate the wave front. The acoustic transformation media require acoustic materials which are anisotropic and inhomogeneous. Such materials are difficult to find in nature. However, composite materials with embedded sub-wavelength resonators can in principle be made and such 'acoustic metamaterials' can exhibit nearly arbitrary values of effective density and modulus tensors to satisfy the demanding material requirements in transformation acoustics. We introduce resonant sonic materials and Helmholtz resonators as examples of acoustic metamaterials that exhibit resonant behaviour in effective density and effective modulus. (topical review)

  16. Acoustic cloaking and transformation acoustics

    In this review, we give a brief introduction to the application of the new technique of transformation acoustics, which draws on a correspondence between coordinate transformation and material properties. The technique is formulated for both acoustic waves and linear liquid surface waves. Some interesting conceptual devices can be designed for manipulating acoustic waves. For example, we can design acoustic cloaks that make an object invisible to acoustic waves, and the cloak can either encompass or lie outside the object to be concealed. Transformation acoustics, as an analog of transformation optics, can go beyond invisibility cloaking. As an illustration for manipulating linear liquid surface waves, we show that a liquid wave rotator can be designed and fabricated to rotate the wave front. The acoustic transformation media require acoustic materials which are anisotropic and inhomogeneous. Such materials are difficult to find in nature. However, composite materials with embedded sub-wavelength resonators can in principle be made and such 'acoustic metamaterials' can exhibit nearly arbitrary values of effective density and modulus tensors to satisfy the demanding material requirements in transformation acoustics. We introduce resonant sonic materials and Helmholtz resonators as examples of acoustic metamaterials that exhibit resonant behaviour in effective density and effective modulus. (topical review)

  17. ESR studies on quartz extracted from shallow fault gouges related to the ms 8.0 Wenchuan earthquake - China - implications for ESR signal resetting in quaternary faults

    Liu, Chun-Ru; Yin, Gong-Ming; Zhou, Yong-Sheng; Gao, Lu; Han, Fei; Li, Jian-ping

    2014-01-01

    ESR dating of the most recent fault activity through quartz signal measurement is based on the assumption that the ESR signal experienced zero resetting during the faulting event. However, several laboratory experiments implied that only partial zeroing of quartz ESR signals was possible. In order to verify whether the signal resetting could be complete under natural conditions, we analyzed quartz recovered from fault gouges after the 2008 Ms 8.0 Wenchuan earthquake. The quartz E’ and Al cent...

  18. Electron spin resonance (ESR) studies on irradiated cocoa beans and niger seeds

    Electron spin resonance (ESR) spectra of irradiated (10kGy) and unirradiated cocoa beans and niger seeds have been compared. Unirradiated cocoa beans failed to give any ESR signal, whereas after irradiation (10kGy) an ESR signal at g = 2.0042 was observed. However, ESR signals are given by both irradiated and unirradiated niger seeds. The intensity of signal was found to be dose-dependent up to 10kGy for both seeds. The signals were stable up to 180 days in both cases. The results indicate the possibility of using ESR for distinguishing between irradiated and unirradiated cocoa beans but not for niger seeds

  19. On-Chip ESR Measurements of DPPH at mK Temperatures

    Voesch, Wolfgang; Thiemann, Markus; Bothner, Daniel; Dressel, Martin; Scheffler, Marc

    We study electron spin resonance (ESR) of DPPH at mK temperatures. Here we employ a superconducting coplanar microwave resonator that allows convenient implementation in a dilution refrigerator as well as operation at multiple ESR frequencies, in this case 1.5 GHz, 3.0 GHz, and 4.5 GHz. We find a strong temperature and magnetic field dependence of the ESR of DPPH below 1 K, which is consistent with an antiferromagnetic transition. Our study documents the potential of this on-chip ESR technique for mK experiments and elucidates the possibility to use DPPH as an ESR reference material in this regime.

  20. Acoustical Imaging

    Litniewski, Jerzy; Kujawska, Tamara; 31st International Symposium on Acoustical Imaging

    2012-01-01

    The International Symposium on Acoustical Imaging is a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. This interdisciplinary Symposium has been taking place continuously since 1968. In the course of the years the proceedings volumes in the Acoustical Imaging Series have become a reference for cutting-edge research in the field. In 2011 the 31st International Symposium on Acoustical Imaging was held in Warsaw, Poland, April 10-13. Offering both a broad perspective on the state-of-the-art as well as  in-depth research contributions by the specialists in the field, this Volume 31 in the Series contains an excellent collection of papers in six major categories: Biological and Medical Imaging Physics and Mathematics of Acoustical Imaging Acoustic Microscopy Transducers and Arrays Nondestructive Evaluation and Industrial Applications Underwater Imaging

  1. ESR and related experiments in spin-polarized atomic hydrogen

    This thesis deals with some experiments in (gaseous) spin-polarized atomic hydrogen. One uses the expression 'stabilized' atomic hydrogen, meaning that by choosing suitable conditions one can suppress the tendency of atoms to recombine into H2 molecules, such that the lifetime of the atomic state is extended by many orders of magnitude. Research is focused at the study of processes that determine the decay rate of polarized H samples, with the ultimate goal of preparing samples of sufficiently high density and at low enough temperature to observe experimentally the behaviour of the (degenerate) quantum gas. ESR (Electron Spin Resonance) appears to be a very suitable measurement technique to study the properties of polarized H. This work describes the introduction of ESR as detection technique, and the first results of an experiment in polarized H using this technique. (orig.)

  2. Dose determination in irradiated chicken meat by ESR method

    In this work, the properties of the radicals produced in chicken bones have been investigated by ESR technique to determine the amount of dose applied to the chicken meats during the food irradiation. For this goal, the drumsticks from 6-8 weeks old chickens purchased from a local market were irradiated at dose levels of 0; 2; 4; 6; 8 and 10 kGy. Then, the ESR spectra of the powder samples prepared from the bones of the drumsticks have been investigated. Unirradiated chicken bones have been observed to show a weak ESR signal of single line character. CO-2 ionic radicals of axial symmetry with g=1.9973 and g=2.0025 were observed to be produced in irradiated samples which would give rise to a three peaks ESR spectrum. In addition, the signal intensities of the samples were found to depend linearly on the irradiation dose in the dose range of 0-10 kGy. The powder samples prepared from chicken leg bones cleaned from their meats and marrow and irradiated at dose levels of 1, 2, 3, 4, 5, 6, B, 10, 12,14, 16, 1B, 20 and 22 kGy were used to get the dose-response curve. It was found that this curve has biphasic character and that the dose yield was higher in the 12-1B kGy dose range and a decrease appears in this curve over 18 kGy. The radical produced in the bones were found to be the same whether the irradiation was performed after stripping the meat and removing the marrow from the bone or before the stripping. The ESR spectra of both irradiated and non irradiated samples were investigated in the temperature range of 100 K-450 K and changes in the ESR spectra of CO-2 radical have been studied. For non irradiated samples (controls). the signal intensities were found to decrease when the temperature was increased. The same investigation has been carried out for irradiated samples and it was concluded that the signal intensities relative to the peaks of the radical spectrum increase in the temperature range of 100 K-330 K, then they decrease over 330 K. The change in the

  3. Detection of irradiated chicken by ESR spectroscopy of bone

    Ionizing radiation has been used to treat poultry to remove harmful microorganisms, mainly Salmonella, which contaminates chicken, goose and other fresh and frozen poultry. This microorganism is sensitive to low dose radiation. Thus, irradiating these foods with doses between 1 to 7 kGy results in a large reduction of bacteria. Since it is necessary to determine whether irradiation has occurred and to what extend, this work studied the signal produced by ionizing radiation within the hard crystalline matrix of chicken's bone to establish a control method. Chicken's drumsticks were irradiated and bones separated from flesh were lyophilized and milled. ESR spectrum was then obtained. The ESR signal increased linearly with dose over the range 0.25 to 8.0 kGy. Free radicals evaluated during 30 days after irradiation showed stable in this period. (Author)

  4. ESR spectroscopic investigations of the radiation-grafting of fluoropolymers

    Huebner, G.; Roduner, E. [University of Stuttgart (Germany); Brack, H.P.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    ESR spectroscopic investigations have clarified the influence of several preparative parameters on the reaction rates and yields obtained in the radiation-grafting method used at PSI to prepare proton-conducting polymer membranes. At a given irradiation dose, a higher concentration of reactive radical sites was detected in ETFE films than in FEP films. This higher concentration explains the higher grafting levels and rates of the ETFE films found in our previous grafting experiments. Taken together, the in-situ ESR experiments and grafting experiments show that the rates of disappearance of radical species and grafting rates and final grafting levels depend strongly on the reaction temperature and the oxygen content of the system. Average grafted chain lengths were calculated to contain about 1,000 monomer units. (author) 2 figs., 4 refs.

  5. ESR detection of black pepper using standard addition method

    ESR techniques for studying the detection of radicals induced in gamma ray irradiated pepper were studied. The representative ESR spectrum of the pepper composed of a sextet centered at g=2.0, a single at the same g-value and a singlet at g=4.0. This reflects the evidence of three independent radicals in the pepper before irradiation. Upon gamma ray irradiation, a new pair of signals appeared. Using standard addition method for solid sample technique we prepared the experimental samples containing 2.0 - 20.0 w/w % irradiated black pepper. The progressive saturation behavior (PSB) at various microwave power levels indicated quite different relaxation behaviors of those signals. For the evaluation of radiation-induced radicals and irradiation effects we proposed a new protocol using the standard addition method. This would be called an advanced protocol for the detection of irradiated black pepper. (author)

  6. The DL-alanine ESR dosimeter in the radiation processing

    In this paper, the basic dosimetric characters of the alanine/ESR dosimeter used in radiation processing is introduced and the method for preparing the dosimeter is discussed. An excellent linearity in the range of 102Gy --- 104Gy was observed. The linear correlation coefficient between the amplitude of the main peak of ESR signal and the correspondent dose is greater than 0.9999. A special instrument was designed for fixing the lower end of the sample tube. It improved the standard deviation from ±1.1% to ±0.45% and the linear relations between gain settings of the spectrometer were amended. The dispersivity of the signal amplitude for many of dosimeters with a dose of 1 KGy was studied and the standard deviation of the signals was ±0.55. The correction factor of dosimeters for the response value of the radiation temperature was 0.0021/0C. (author)

  7. ESR measurements of background doses in teeth of Japanese residents

    The background doses for the teeth of Japanese residents were obtained by electron spin resonance (ESR) method. The doses obtained from 77 of 92 samples are less than 100 mGy while the doses of the other samples are high up to 250 mGy. The doses for buccal part of the teeth are higher than lingual part possibly due to contributions from dental X ray examination. A positive correlation was found between the ages of the donors and the obtained doses. The averaged annual ESR dose was calculated to be 0.87 mGy/y. These doses have to be considered in actual retrospective dosimetry studies for possible radiation accidents. The statistically significant critical level for Japanese residents would be about 200 mGy for individual doses and about 100 mGy for averaged group doses for α = 5% for those with ages older than 50.

  8. ESR accident dosimetry using medicine tablets coated with sugar

    Properties of radiation-induced radicals in medicine tablets were investigated using electron spin resonance (ESR). A sharp ESR signal sensitive to gamma ray irradiation was observed in the sugar coating part of the tablets. The signal has anisotropic g values of g1 = 2.0009, g2 = 2.0007 and g3 = 2.0002. The signal grows linearly with dose at least up to about 20 Gy. No fading was observed at room temperature even when exposed to sunlight. The dose to artificially irradiated tablets was estimated using the signal intensity and a previously determined calibration curve. The signal in sugar coated tablets can be utilised for dose measurements. In particular, the wide distribution of sugar coated tablets allows the use of the tablets as accident dosemeters. (author)

  9. Detection method of irradiated green tea using ESR

    With electron spin resonance (ESR) spectroscopy, we revealed various radicals in commercially available Japanese green tea before and after γ-irradiation. The representative ESR spectrum of green tea is composed of sextet centered at g=2.0, a singlet at the same g value and a singlet at g=4.0. The first signal is attributable to a signal with hyperfine interaction of the Mn2+. The second signal is due to an organic free radical. The third signal may originate from the Fe3+. Upon irradiation, a pair of signals was newly appeared at the symmetric positions on both sides of the organic free radical signal. According to the theory of radical production in irradiated solid, a linear relationship is expected between the radiation dose and the radical yield. We determined the unreported irradiation dose by the linear extrapolation. (author)

  10. Radiation acoustics

    Lyamshev, Leonid M

    2004-01-01

    Radiation acoustics is a developing field lying at the intersection of acoustics, high-energy physics, nuclear physics, and condensed matter physics. Radiation Acoustics is among the first books to address this promising field of study, and the first to collect all of the most significant results achieved since research in this area began in earnest in the 1970s.The book begins by reviewing the data on elementary particles, absorption of penetrating radiation in a substance, and the mechanisms of acoustic radiation excitation. The next seven chapters present a theoretical treatment of thermoradiation sound generation in condensed media under the action of modulated penetrating radiation and radiation pulses. The author explores particular features of the acoustic fields of moving thermoradiation sound sources, sound excitation by single high-energy particles, and the efficiency and optimal conditions of thermoradiation sound generation. Experimental results follow the theoretical discussions, and these clearl...

  11. Electron cooling of highly charged ions in the ESR

    The ESR storage ring offers the unique opportunity to store and cool fully stripped heavy ions up to uranium at energies between 50 and 370 MeV/u. Measurements of the longitudinal cooling force for several ion species from C6+ to U92+ are presented. A pronounced deviation from the expected q2 scaling was found. Further investigations have been performed to study the influence of magnetic field strength on the longitudinal cooling force. (orig.)

  12. ESR detection procedure of irradiated papaya containing high water content

    Kikuchi, Masahiro; Shimoyama, Yuhei; Ukai, Mitsuko; Kobayashi, Yasuhiko

    2011-05-01

    ESR signals were recorded from irradiated papaya at liquid nitrogen temperature (77 K), and freeze-dried irradiated papaya at room temperature (295 K). Two side peaks from the flesh at the liquid nitrogen temperature indicated a linear dose response for 3-14 days after the γ-irradiation. The line shapes recorded from the freeze-dried specimens were sharper than those at liquid nitrogen temperature.

  13. ESR detection procedure of irradiated papaya containing high water content

    ESR signals were recorded from irradiated papaya at liquid nitrogen temperature (77 K), and freeze-dried irradiated papaya at room temperature (295 K). Two side peaks from the flesh at the liquid nitrogen temperature indicated a linear dose response for 3-14 days after the γ-irradiation. The line shapes recorded from the freeze-dried specimens were sharper than those at liquid nitrogen temperature.

  14. ESR detection procedure of irradiated papaya containing high water content

    Kikuchi, Masahiro, E-mail: kikuchi.masahiro@jaea.go.j [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Shimoyama, Yuhei [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Ukai, Mitsuko [Hokkaido University of Education, 1-2 Hachiman-cho, Hakodate, Hokkaido 040-8567 (Japan); Kobayashi, Yasuhiko [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan)

    2011-05-15

    ESR signals were recorded from irradiated papaya at liquid nitrogen temperature (77 K), and freeze-dried irradiated papaya at room temperature (295 K). Two side peaks from the flesh at the liquid nitrogen temperature indicated a linear dose response for 3-14 days after the {gamma}-irradiation. The line shapes recorded from the freeze-dried specimens were sharper than those at liquid nitrogen temperature.

  15. ESR study of AuEr dilute alloys

    Dokter, H. D.; Davidov, D.; Hoekstra, F. R.; Nieuwenhuys, G. J.

    1981-06-01

    ESR linewidth and signal intensity measurements of AuEr (0.2%, 1%, 3%) dilute alloys have been carried out as a function of temperature in order to resolve previous discrepancies regarding the crystal field splitting. The data analysis indicates a splitting of (16 ± 4) K between the Γ 7 ground state and the Γ (1)8 first excited state. No evidence for an additional broadening mechanism associated with Er-Er exchange interactions was observed.

  16. Sistemi liquido cristallini complessi: simulazioni al calcolatore e studi ESR

    Miglioli, Isabella

    2010-01-01

    The aim of this PhD thesis was to study at a microscopic level different liquid crystal (LC) systems, in order to determine their physical properties, resorting to two distinct methodologies, one involving computer simulations, and the other spectroscopic techniques, in particular electron spin resonance (ESR) spectroscopy. By means of the computer simulation approach we tried to demonstrate this tool effectiveness for calculating anisotropic static properties of a LC material, a...

  17. Revised dose-rate data for thermoluminescence/ESR dating

    An analytical up-to-date catalogue of annual dose conversion factors for the isotopes of uranium-(238, 235), thorium-232, potassium-40 and rubidium-86, and their daughter products is presented for use in thermoluminescence/ESR radiometric dating, as well as in other dosimetric applications. Discernible discrepancies of up to 5% were encountered between the present and earlier dose-rate values. (Author)

  18. ESR detection of wheat flour before and after irradiation

    Shimoyama, Yuhei; Ukai, Mitsuko; Nakamura, Hideo

    2006-03-01

    We revealed free radicals in wheat flour before and after γ-ray irradiation and their thermal behavior during heat-treatment using electron spin resonance (ESR) spectroscopy. The ESR spectrum of wheat flour before irradiation consists of a sextet centered at g = 2.0 and a singlet signal at the same g-value position. The first one is attributable to a signal with hyperfine (hf) interactions of Mn 2+ ion (hf constant: 7.4 mT). The second is originated from carbon-centered radical. Upon γ-ray irradiation, however, a new signal with two triplet lines at the low and high field ends was detected in wheat flour on top of the Mn 2+ sextet lines. We analyzed the triplet ESR lines as powder spectra (rhombic g-tensor symmetry) with nitrogen ( 14N) hyperfine interactions. This indicates that a new organic radical was induced in the conjugated protein portion of wheat flour by the γ-ray irradiation. Intensity of the organic free radical at g = 2.0 detected in irradiated wheat flour increased monotonically by the thermal treatment. The analysis of the time-dependent evolution and decay process based on the theory of transient phenomena as well as the nonlinear least-squares numerical method provided a unique time constant for the radical evolution and decay in wheat flour during the heat-treatment.

  19. The alpha effectiveness of the dating ESR signal in barite

    The alpha effectiveness was investigated for an ESR signal due to SO3− in barite by comparing the dose responses of the signal for gamma irradiation and for He ion implantation with an energy of 4 MeV. The value was obtained to be 0.043 ± 0.018 for samples from Morocco and to be 0.0089 ± 0.0006 for Kanehira Mine. The dose response for He ion implantation for the latter sample better fits to a correlation line but the signal shape changes with gamma ray dose, indicating contribution from an unknown radiation sensitive signal, while the former sample shows the same signal shapes. A value of 0.043 ± 0.018 is adopted as the alpha effectiveness of SO3− signal in barite, which is used for ESR dating of submarine hydrothermal activity. - Highlights: ► The alpha effectiveness is one of the essential factors in ESR dating. ► The alpha effectiveness value was determined for barite. ► The dose responses for gamma and for He ion implantation were compared. ► A sample shows signal shape change by gamma ray irradiation.

  20. ESR Study on Irradiated Ascorbic Acid Single Crystal

    Food irradiation is a 'cold' process for preserving food and has been established as a safe and effective method of food processing and preservation after more than five decades of research and development. The small temperature increase, absence of residue and effectiveness of treatment of pre-packed food are the main advantages. In food industry, ascorbic acid and its derivatives are frequently used as antioxidant agents. However, irradiation is expected to produces changes in the molecules of food components and of course in the molecules of the agents added as preservation agents such as ascorbic acid. These changes in the molecular structures could cause decreases in the antioxidant actions of these agents. Therefore, the radiation resistance of these agents must be known to determine the amount of radiation dose to be delivered. Electron spin resonance (ESR) is one of the leading methods for identification of intermediates produced after irradiation. ESR spectrum of irradiated solid powder of ascorbic acid is fairly complex and determinations of involved radical species are difficult. In the present work, single crystals of ascorbic acid irradiated by gamma radiation are used to determine molecular structures of radiation induced radicalic species and four radicalic species related in pair with P21 crystal symmetry are found to be responsible from experimental ESR spectrum of gamma irradiated single crystal of ascorbic acid

  1. An ESR study on biological dosimeters: Human hair

    In the present work, characteristic features of the radicals found in untreated, gamma and UV-irradiated and mechanical damaged human hair samples were investigated by ESR spectroscopy. Heights of the resonance peaks measured with respect to the spectrum base line were used to monitor microwave power, dose-response, storage time and temperature dependent kinetic features of the radical species contributing to the formation of recorded experimental ESR spectra. Peak heights and g-values (2.0037-2.0052) determined from recorded spectra of hair were color dependent with ΔHpp-0.47 mT. The act of cutting hair samples gene rates sulfur centered radicals which are found in the a-keratin structure of hair. The variations of the peak heights with temperature were related with the water content found in the hair samples. In the 6-1100 Gy dose range, a linear + quadratic dose-response curve was recorded for hair and the mean radiation yield (Gmean) was calculated to be 0.4. The gamma radiation induced radicals were stable for a several hours at room temperature storage conditions. Based on these findings it was concluded that human hair samples could be used as biological/personnel dosimeters and that ESR spectroscopy could be successfully used as a potential technique for monitoring its dosimetric behaviours.

  2. How to improve calibration for analytical accuracy in ESR spectrometry

    Electron spin resonance (ESR) has proved to be a very effective tool of dosimetry. Characteristics of Alanine/ESR dosimetry system is better suitable than routinely used personnel dosimeters for the long term radiation measurement in harsh condition of Nuclear power plant : This system is not significantly affected by temperature and humidity and also has low fading rate. About 2 years ago, alanine and lithium compound dosimeters were installed at Wolsung unit 1 for the environment monitoring as a part of equipment qualification program. Afterward, the dosimeters were also installed at the other nuclear power plants. The recovered alanine dosimeters in the period of maintenance were measured by E-scan alanine analyzer system or EMX ESR spectrometer. For the accurate measurement of the dosimeters, we have studied various source of errors. This paper discusses sources of inaccuracy related to data processing. Errors in data processing were researched by E-scan alanine analyzer system. E-scan alanine analyzer system proposes the fit function with best f-statistics but the user may choose a different one. This fact is useful for our research

  3. Influence of sample treatment on ESR signal of irradiated citrus.

    de Jesus, E F; Rossi, A M; Lopes, R T

    1996-01-01

    ESR spectra of the hard seed cover and kernel coating of irradiated orange and tangerine fruits were obtained under different sample drying conditions to analyze the effect of treatment on ESR line at g = 2.0033 (line A). The spectra shows almost the same lines that appear in stalks, achenes, seeds and skins of fresh fruit. The peak-to-peak intensity of the line A of the spectra shows a linear variation with dose in the range studied (up to 5 kGy) under controlled sample preparation. Q-band ESR spectra shows that this line is composed for three different lines from different species. A1, A2 and A3. The A2 and A3 lines are associated with dose but grow also during drying of the sample and are probably due to 'cellulosic' components of the seed cover. The A1 line appears only when sample is dried and is probably associated with the quinones of the internal kernel coat. PMID:9022204

  4. ESR radiation dose evaluation on radiation exposure accident in England

    A technician of nondestructive inspection in England died because of radiation injury even though his exposure record with film badge indicated only 104 mSv of the lifelong exposure dose. After the request of the National Radiation Protection Board of Great Britain, the author conducted measurement of the exposure dose with ESR dosimetry. ESR spectra were measured on tooth enamel and bones of the finger and the upper arm taken from the dead technician. The exposure dose is obtained from the enhancement of the ESR signal intensity of CO2- after international irradiation. 14 and 12 Gy for tooth enamel, 7.2 and 4.2 Gy for the bones of the finger and the upper arm respectively. The bone samples may show smaller dose due to metabolism in the body. The technician is assumed to be exposed about 10 mSv at the fingers and the arms for each time on the inspection of pipings for more than 10 years. He used to wear the film badge on his waist. The author stresses the importance of preservation of extracted tooth as a exposure record for radiation workers. (T.H.)

  5. Detection of irradiated chicken by hydrocarbon and ESR methods

    Chicken meat with bone was irradiated by gamma rays at -19 - 10degC. Both amounts of hydrocarbons formed from fatty acids and intensity of ESR signals in bone fragments were measured. Very good correlation was found between the amount of hydrocarbons and the intensity of ESR signals. The amount of hydrocarbons (Cn-2:1), having 2 carbon atoms less than the original fatty acids and an additional double bond, was almost constant irrespective of the irradiation temperature. The amount of hydrocarbons (Cn-1:0), having 1 carbon atom less than the original fatty acids, increased as the irradiation temperature raised. As the ratio between corresponding fatty acids, the ratio between hydrocarbons (Cn-2:1) is a suitable index in the detection of the irradiation. On the contrary, the ratio of hydrocarbons from the same fatty acid, (Cn-2:1)/(Cn-1:0), varied according to the kind of fatty acid and irradiation temperature. It was found that under the irradiation temperature of -19 - 10degC, the intensity of ESR signals of bone is not affected by the irradiation temperature. (J.P.N.)

  6. Detection of irradiated chicken by hydrocarbon method and ESR method

    Chicken meat with bone was irradiated by gamma ray at - -19∼10degC, and both amount of hydrocarbons formed from fatty acids and intensity of ESR signals in bone fragments were measured. Very good correlation was found between the amount of hydrocarbons and the intensity of ESR signals. The amount of hydrocarbons (Cn-2 : 1), had 2 carbon atoms less than the original fatty acids and an additional double bond, was almost constant irrespective of the irradiation temperature. The amount of hydrocarbons (Cn-1: 0), had l carbon atom less than the original fatty acids, increased as the irradiation temperature raised. As the ratio between corresponding fatty acids, the ratio between hydrocarbons (Cn-2 : l) is a suitable index in the detection of the irradiation. On the contrary, the ratio of hydrocarbons from same fatty acid, (Cn-2 : 1)/(Cn-1 : 0), varied according to the kind of fatty acid and temperature used at the irradiation. It was found that under the irradiation temperature of -19∼10degC, intensity of ESR signals of bone is not affected by the irradiation temperature. (author)

  7. Estimation of dose in irradiated chicken bone by ESR method

    The author studied the conditions needed to routinely estimate the radiation dose in chicken bone by repeated re-irradiation and measuring ESR signals. Chicken meat containing bone was γ-irradiated at doses of up to 3kGy, accepted as the commercially used dose. The results show that points in sample preparation and ESR measurement are as follows: Both ends of bone are cut off and central part of compact bone is used for experiment. To obtain accurate ESR spectrum, marrow should be scraped out completely. Sample bone fragments of 1-2mm particle size and ca.100mg are recommended to obtain stable and maximum signal. In practice, by re-irradiating up to 5kGy and extrapolating data of the signal intensity to zero using linear regression analysis, radiation dose is estimated. For example, in one experiment, estimated doses of chicken bones initially irradiated at 3.0kGy, 1.0kGy, 0.50kGy and 0.25kGy were 3.4kGy, 1.3kGy, 0.81kGy and 0.57kGy. (author)

  8. An ESR study on biological dosimeters: Human hair

    Colak, Seyda, E-mail: seyda@hacettepe.edu.t [Hacettepe University, Physics Engineering Department, 06800 Ankara (Turkey); Ozbey, Turan [Hacettepe University, Physics Engineering Department, 06800 Ankara (Turkey)

    2011-05-15

    In the present work, characteristic features of the radicals found in untreated, gamma and UV-irradiated and mechanical damaged human hair samples were investigated by ESR spectroscopy. Heights of the resonance peaks measured with respect to the spectrum base line were used to monitor microwave power, dose-response, storage time and temperature dependent kinetic features of the radical species contributing to the formation of recorded experimental ESR spectra. Peak heights and g-values (2.0037-2.0052) determined from recorded spectra of hair were color dependent with {Delta}Hpp-0.47 mT. The act of cutting hair samples gene rates sulfur centered radicals which are found in the a-keratin structure of hair. The variations of the peak heights with temperature were related with the water content found in the hair samples. In the 6-1100 Gy dose range, a linear + quadratic dose-response curve was recorded for hair and the mean radiation yield (G{sub mean}) was calculated to be 0.4. The gamma radiation induced radicals were stable for a several hours at room temperature storage conditions. Based on these findings it was concluded that human hair samples could be used as biological/personnel dosimeters and that ESR spectroscopy could be successfully used as a potential technique for monitoring its dosimetric behaviours.

  9. ESR dating technique applied to Pleistocene Corals (Barbados Island)

    In this work we applied the ESR (Electron Spin Resonance) dating technique to a coral coming from Barbados island. After a preliminary purification treatment, coral samples were milled and separated in different granulometry groups. Powder samples having granulometry values between 125 μm-250 μm and 250 μm-500 μm were irradiated at the Calliope60 Co radioisotope source (R.C. ENEA-Casaccia) at doses between 10-3300 Gγ and their radiation induced ESR signals were measured by a Bruker EMS1O4 spectrometer. The signal/noise ratio turned to be highest far the granulometry between 250 μm-500 μm and consequently the paleo-curve was constructed by using the ESR signals related to this granulometry value. The paleo-curve was fitted with the exponential growth function y = a - b · e-cx which well describes the behaviour of the curve also in the saturation region. Extrapolating the paleo-dose and knowing the annual dose (999±79 μGy/y) we calculated a coral age of 156±12 ky, which is in good agreement with results obtained on coral coming from the same region by other authors

  10. Frequency dependent power fluctuations: a feature of the ESR system or physical?

    Y. Ogawa

    Full Text Available The k-dependence of the received power in high signal-to-noise ratio (SNR conditions, occurring for naturally enhanced ion-acoustic lines (NEIALs and for real satellites, is investigated by using the EISCAT Svalbard Radar (ESR, where the data are recorded in eight separate channels using different frequencies. For the real satellites we find large variations of the relative powers from event to event, which is probably due to a different number of pulses catching the satellite over the integration period. However, the large power difference remains unexpected in one case. Over short time scale (< 10 s the relative power difference seems to be highly stable. For most NEIAL events the differences between channels are within noise level. In a few cases variations of the relative power well above both the estimated and expected 1-sigma level occur over a signal preintegrated profile. We thus suggest that the frequency dependence of the power in NEIAL events has its origin in the scattering medium itself as the most plausible explanation.

    Key words: Ionosphere (auroral ionosphere; plasma waves and instabilities; instruments and techniques

  11. Reliability of quartz Ti-center in ESR dating of fluvial sediment

    For the fluvial sediments older than 200 ka, reliable dating method is yet to be established. ESR is a potential way. In this work, the Matuyama/Brunhes boundary (about 780 ka) samples were collected from the Gaoliying drill, Beijing and the Donggutuo site of the Nihewan basin, Heibei province. Quartz Ti-center ESR signals of the samples were analyzed. The results suggest that the ESR ages of the Matuyama/Brunhes boundary samples are consistent with the ages of paleo-magnetic investigation in deviation of 10%. Meanwhile, measurements of samples from the Gaoliying at different depths were performed. The results suggest that the ESR ages become older with the buried depth. All these indicate the reliability of quartz Ti-center in ESR dating of fluvial sediment, and we can gain the age of fluvial sediment at least younger than 780 ka using quartz Ti-center ESR signal. (authors)

  12. Battlefield acoustics

    Damarla, Thyagaraju

    2015-01-01

    This book presents all aspects of situational awareness in a battlefield using acoustic signals. It starts by presenting the science behind understanding and interpretation of sound signals. The book then goes on to provide various signal processing techniques used in acoustics to find the direction of sound source, localize gunfire, track vehicles, and detect people. The necessary mathematical background and various classification and fusion techniques are presented. The book contains majority of the things one would need to process acoustic signals for all aspects of situational awareness in one location. The book also presents array theory, which is pivotal in finding the direction of arrival of acoustic signals. In addition, the book presents techniques to fuse the information from multiple homogeneous/heterogeneous sensors for better detection. MATLAB code is provided for majority of the real application, which is a valuable resource in not only understanding the theory but readers, can also use the code...

  13. Acoustical Imaging

    Akiyama, Iwaki

    2009-01-01

    The 29th International Symposium on Acoustical Imaging was held in Shonan Village, Kanagawa, Japan, April 15-18, 2007. This interdisciplinary Symposium has been taking place every two years since 1968 and forms a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. In the course of the years the volumes in the Acoustical Imaging Series have developed and become well-known and appreciated reference works. Offering both a broad perspective on the state-of-the-art in the field as well as an in-depth look at its leading edge research, this Volume 29 in the Series contains again an excellent collection of seventy papers presented in nine major categories: Strain Imaging Biological and Medical Applications Acoustic Microscopy Non-Destructive Evaluation and Industrial Applications Components and Systems Geophysics and Underwater Imaging Physics and Mathematics Medical Image Analysis FDTD method and Other Numerical Simulations Audience Researcher...

  14. Acoustic telemetry

    National Oceanic and Atmospheric Administration, Department of Commerce — To determine movements of green turtles in the nearshore foraging areas, we deployed acoustic tags and determined their movements through active and passive...

  15. Acoustics Research

    National Oceanic and Atmospheric Administration, Department of Commerce — Fisheries acoustics data are collected from more than 200 sea-days each year aboard the FRV DELAWARE II and FRV ALBATROSS IV (decommissioned) and the FSV Henry B....

  16. Electron spin resonance (ESR) spectroscopy applied to radiation dosimetry and other fields

    A short introduction to the theory and practice of ESR spectroscopy is given. ESR alanine dosimetry for low and high LET (linear energy transfer) ionising radiation is described, indicating its advantages over traditional methods. Problems arising in the therapy dose range (below 5 Gy), and possible future developments, are mentioned. The application of ESR to the radiation processing of materials and foodstuffs, to geological dating, biology, molecular chemistry and to medicine is discussed. Some examples of chemical analyses are also presented. (orig.)

  17. ESR1 and EGF genetic variation in relation to breast cancer risk and survival

    Einarsdóttir, Kristjana; Darabi, Hatef; Li, Yi; Low, Yen Ling; Li, Yu Qing; Bonnard, Carine; Sjölander, Arvid; Czene, Kamila; Wedrén, Sara; Liu, Edison T.; Hall, Per; Humphreys, Keith; Liu, Jianjun

    2008-01-01

    Introduction Oestrogen exposure is a central factor in the development of breast cancer. Oestrogen receptor alpha (ESR1) is the main mediator of oestrogen effect in breast epithelia and has also been shown to be activated by epidermal growth factor (EGF). We sought to determine if common genetic variation in the ESR1 and EGF genes affects breast cancer risk, tumour characteristics or breast cancer survival. Methods We genotyped 157 single nucleotide polymorphisms (SNPs) in ESR1 and 54 SNPs in...

  18. Alanine-ESR in vivo dosimetry: a feasibility study and possible applications

    A new alanine-ESR dosimeter has been developed at AERIAL in order to study its potential use in radiotherapy. Alanine-ESR results are compared with ion chamber for depth-dose measurements. A good concordance has been found between provisional dosimetry and absorbed dose during high dose rate and intra operative treatments. The results of the experiments indicate that alanine-ESR dosimetry is suited to check dose optimisation routines and seems to be a promising in vivo dosimetry technique. (Author)

  19. A study of the composite character of the ESR spectrum of alanine

    Both L and DL-alanine ESR powder spectra have been studied in the dose range of 1-106 Gy. By using Maximum Likelihood Common Factor Analysis (MLCFA), it has been demonstrated that the ESR spectrum of L-alanine is at least 3-fold composite over the whole dose range considered. For DL-alanine, in certain dose ranges only two ESR components could be detected. Possible consequences for the application and optimization of alanine dosimetry are discussed. (Author)

  20. GATA3 acts upstream of FOXA1 in mediating ESR1 binding by shaping enhancer accessibility

    Theodorou, V.; Stark, R.; Menon, S.; Carroll, J. S.

    2013-01-01

    Estrogen receptor (ESR1) drives growth in the majority of human breast cancers by binding to regulatory elements and inducing transcription events that promote tumor growth. Differences in enhancer occupancy by ESR1 contribute to the diverse expression profiles and clinical outcome observed in breast cancer patients. GATA3 is an ESR1-cooperating transcription factor mutated in breast tumors; however, its genomic properties are not fully defined. In order to investigate the composition of enha...

  1. Electron spin resonance (ESR) in multiferroic TbMnO3

    We report temperature dependent X-Band (ν∼9.4GHz) electron spin resonance (ESR) measurement in a single crystal of TbMnO3. A single Lorentzian ESR line with an isotropic g∼ 1.96 was observed for T>=120K up to 600K. The ESR signal is attributed to the Mn3+ ions in a insulator environment. For the three crystallographic axes the temperature dependence ESR linewidth shows a strong broadening as the temperature decreases due to the presence of short range magnetic correlations

  2. Detection of gamma-irradiated peanuts by ESR spectroscopy and GC analysis of hydrocarbons

    Peanuts were analyzed by electron spin resonance (ESR) spectroscopy and gas chromatography (GC) before and after gamma irradiation. Using European protocols, the validity and effectiveness of these two techniques were compared with regard to sample preparation, sample and solvent consumption and dose-response curves after irradiation. The results showed the possibility of using ESR and GC for distinguishing between irradiated and unirradiated peanuts. A radiation dose of 0.1 kGy could be detected by ESR but not by GC. The results also indicated that GC is an effective method for qualitative analysis of irradiated peanut, while ESR is suitable for the rapid detection of irradiated peanuts.

  3. Association with litter size of new polymorphisms on ESR1 and ESR2 genes in a Chinese-European pig line

    Rodriguez Carmen

    2007-02-01

    Full Text Available Abstract The objective of this study was to search for polymorphisms in the coding region of the estrogen receptors 1 and 2 (ESR1 and ESR2 and to analyze the effects of these variants and the well known intronic ESR1 Pvu II polymorphism on litter size in a Chinese-European pig line. We identified five silent single nucleotide polymorphisms (SNP in the ESR1 cDNA: c.669T > C (exon 3, c.1227C > T (exon 5, c.1452C > T (exon 7, c.1665T > C and c.1755A > G (exon 8. One pair of these SNP (c.1665T > C and c.1755A > G co-segregated in the analyzed line, and the SNP c.669T > C showed the same segregation pattern as the Pvu II polymorphism. These polymorphisms were tested in this study, although the c.1452C > T SNP within exon 7 was not analyzed due to its low informativeness. In the ESR2 cDNA, one missense SNP was found within exon 5, which caused an amino acid substitution in the coded protein: "c.949G > A (p.Val317Met" and was tested on sow litter size. Information on 1622 litter records from 408 genotyped sows was analyzed to determine whether these SNP influenced the total number of piglets born (TNB or the number of born alive (NBA. The polymorphisms ESR1: [Pvu II; c.669T > C], ESR1: [c.1665T > C; c.1755A > G] and ESR2: c.949G > A showed no statistically significant association with litter size. However, the ESR1: c.1227T allele was significantly associated with TNB. The additive substitution effect was estimated to be 0.40 piglets born per litter (P

  4. ESR experiments on quaternary calcites and bones for dating purposes

    A series of experiments and measurements regarding sample preparation, peak intensity estimation, annealing, signal identification, dose determination and dose-rate estimation was carried out in order to explore the technique of ESR for dating speleothemes and bones. Anthropological remains from a cave were used for this study. The results indicate the existence of four peaks, two organic and two radiation induced ones. The bone samples were found to have absorbed large amounts of uranium from the environment making their dating impossible. A range of ages 20-45x103 years was calculated for the travertines of the cave. (author) 15 refs.; 10 figs

  5. Pulse Dipolar ESR and Protein Superstructures and Function

    Freed, Jack

    2014-03-01

    Pulse dipolar electron-spin resonance (PDS-ESR) has emerged as a powerful methodology for the study of protein structure and function. This technology, in the form of double quantum coherence (DQC) - ESR and double-electron-electron resonance (DEER) in conjunction with site-directed spin-labeling will be described. It enables the measurement of distances and their distributions in the range of 1-9 nm between pairs of spins labeled at two sites in the protein. Many biological objects can be studied: soluble and membrane proteins, protein complexes, etc. Many sample morphologies are possible: uniform, heterogeneous, etc. thereby permitting a variety of sample types: solutions, liposomes, micelles, bicelles. Concentrations from micromolar to tens of millimolar are amenable, requiring only small amounts of biomolecules. The distances are quite accurate, so a relatively small number of them are sufficient to reveal structures and functional details. Several examples will be shown. The first is defining the protein complexes that mediate bacterial chemotaxis, which is the process whereby cells modulate their flagella-driven motility in response to environmental cues. It relies on a complex sensory apparatus composed of transmembrane receptors, histidine kinases, and coupling proteins. PDS-based models have captured key architectural features of the receptor kinase arrays and the flagellar motor, and their changes in conformation and dynamics that accompany kinase activation and motor switching. Another example will be determining the conformational states and cycling of a membrane transporter, GltPh, which is a homotrimer, in its apo, substrate-bound, and inhibitor-bound, states in membrane vesicles providing insight into its energetics. In a third example the structureless (in solution) proteins alpha-synuclein and tau, which are important in Parkinson's disease and in neurodegeneration will be described and the structures they take on in contact with membranes will be

  6. ESR spectra of VOBr2 in alcohols and aqueous solutions

    ESR spectra of VOBr2 solutions in absolutized alcohols ROH (R - Me, Et, i-Pr) and aqueous solutions in the presence of LiBr and HBr are investigated and parameters of spin-hamiltonian of vanadium oxocomplexes are determined. Stabilization of [VOBr(ROH)4]+ complex, in which bromide-ion occupies position in xy plane, is detected. Isotropic additional HFS from 79,81Br atoms at the temperature close to the solution boiling point is found, and at 77 K -anisotropic additional HFS in the range of transitions corresponding to perpendicular orientation of particles as to magnetic field

  7. Absorbed dose measurement on disprin tablets by ESR technique

    In this investigation an attempt has been made to measure the dose from free radicals induced in medicine tables by ESR. About 60mg of powdered irradiated Disprin tablets (acetyl salicylic acid 72% calcium carbonate 21% anhydrous citric acid 7%) was loaded into quartz tube and free radical density was measured using Bruker ESP-300 spectrometer. A linear response of dose with peak to peak height was obtained in the range of 1Gy to 700Gy at g=1.9975. (author). 5 refs., 1 fig

  8. Can ESR spectroscopy be used to detect irradiated food?

    The development of a test or tests for the detection of irradiated food would facilitate international trade in irradiated food and enhance consumer confidence in the existing control procedures. Over many years, extensive research programmes have been devoted to understanding the chemical changes which occur in irradiated foods and to establishing the effects of irradiation on the microbiological, organoleptic and nutritional quality of foods. Less effort has been directed towards the development of detection methods. The use of electron spin resonance (ESR) spectroscopy for the detection of irradiated food is being examined. (author)

  9. ESR and Microwave Absorption in Boron Doped Diamond Single Crystals

    Timms, Christopher

    2015-03-01

    Superconductivity has been reportedly found in boron-doped diamond. Most research to date has only studied superconductivity in polycrystalline and thin film boron-diamonds, as opposed to a single crystal. In fact, only one other group has examined a macro scale boron-doped diamond crystal. Our group has successfully grown large single crystals by using the High Temperature High Pressure method (HTHP) and observed a transition to metallic and superconducting states for high B concentrations. For the present, we are studying BDD crystal using Electron Spin Resonance. We conducted our ESR analysis over a range of temperatures (2K to 300K) and found several types of signals, proving the existence of charge carriers with spin 1/2 in BDD. Moreover, we have found that with increasing B concentrations, from n ~ 1018 cm-3 to n of over 1020 cm-3, the ESR signal changes from that of localized spins to the Dysonian shape of free carriers. The low magnetic field microwave absorption has also been studied in BDD samples at various B concentrations and the clear transition to superconducting state has been found below Tc that ranges from 2K to 4 K depending on concentration and quality of crystal. Sergey Polyakov, Victor Denisov, Vladimir Blank, Ray Baughman, Anvar Zakhidov.

  10. ESR and TL dosimetry systems: comparative measurements for human phantom

    Stepanenko, V.F.; Skvortsov, V.G.; Ivannikov, A.I. [Medical Radiological Research Center RAMS, Obninsk (Russian Federation)] [and others

    1997-01-01

    Mixtures of small fragments of tooth enamel as well as thermoluminescence (TL) dosimeters were placed into the tissue-equivalent phantom of the human head with skeleton (approximately at the level of the jaws) and irradiated using {sup 137}Cs low dose-rate gamma therapeutic sources (``SELEKTRON`` LDR {sup 137}Cs). Phantom, samples of teeth and TL detectors were irradiated behind water tank to produce scattered irradiation. The same irradiation with the same geometry was performed in air too. For gamma-spectrometry {sup 137}Cs sources with very low activity were used but with the same geometry as therapeutic sources. The absorbed dose in enamel was estimated with the help of ESR spectrometer ``ESP-300 E`` (Brusker). The samples of tooth enamel were partially used for preliminary dose evaluation by ESR signal before starting of experiment. TL dosimetry was performed by TL reader model 8800 (HARSHAW) using TL dosimeters calibrated with {sup 137}Cs. The paper presents data obtained in comparative aspects. (Author).

  11. ESR study on the photo polymerization of dental composites

    ESR (Electron Spin Resonance) spectra in X-band and at room temperature, of dental composites containing Bis-GMA type resin were obtained after irradiated wit conventional curing lamp of visible-light and laser light of red, green and blue colors. The blue light is the most suitable to produce methacrylate free radicals needed to its polymerization. However, Vickers hardness number determined in samples cured with conventional light indicated that their hardness number are equivalent to that obtained with blue light even producing less radicals, probably because conventional lamp generates more heat in the sample which helps its polymerization. Examining samples irradiated with green light, which is inadequate for usual practice by its lacking in energy, it has observed that this material has a striking ability to post cure by itself. It has concluded that the observation made by Ottaviani and collaborators, in a previous publication, that the time recommended by composite makers was insufficient, analyzing only ESR measurements, must be revised. (author)

  12. ESR studies of irradiated ground corn as a dosimeter

    An ESR study of the free radicals induced in γ-irradiated corn was performed. A single line was detected in the dose range of 0.2-1.8 kGy. The samples were previously ground and it was found that this process induces formation of a free radical with the same g factor of 2.004 ± 0.002 as the one found for the radiation induced radicals. The stability of these radicals was studied as a function of the time and temperature. From the analysis of these results it is concluded that there exist three types of radicals with half-lives of 1.5, 96 and 648 h. The relationship between the ESR signal intensity and the applied dose is a linear one in the above mentioned range, and the radiochemical yield value obtained for this material was G = 2.5 ± 0.3, which suggest that the corn itself can be employed as a dosimeter. (author)

  13. ESR study on free radicals trapped in crosslinked polytetrafluoroethylene (PTFE)

    Free radicals in crosslinked PTFE which formed by 60Co γ-rays irradiation at 77 K and at room temperature were studied by electron spin resonance (ESR) spectroscopy. The crosslinked PTFE specimens with different crosslinking density were prepared by electron beam irradiation in the molten state. The ESR spectra observed in the irradiated crosslinked PTFE are much different from those in non-crosslinked PTFE (virgin); a broad singlet component increases with increasing the crosslinking density, G-value of radicals is much higher in crosslinked PTFE than in non-crosslinked one. Free radicals related to the broad component are trapped in the non-crystalline region of crosslinked PTFE and rather stable at room temperature, whereas radicals trapped in amorphous non-crosslinked PTFE are unstable at room temperature. It is thought that most of free radicals trapped in the crosslinked PTFE are formed in the crosslinked amorphous region. The trapped radicals decays around 383 K (110oC) due to the molecular motion of α-relaxation. (Author)

  14. Influence of sample treatment on ESR signal of irradiated citrus

    EST spectra of the hard seed cover and kernel coating of irradiated orange and tangerine fruits were obtained under different sample drying conditions to analyze the effect of treatment on ESR line at g = 2.0033 (line A). The spectra shows almost the same lines that appear in stalks, achenes, seeds and skins of fresh fruit. The peak-to-peak intensity of the line A of the spectra shows a linear variation with dose in the range studied (up to 5 kGy) under controlled sample preparation. Q-band ESR spectra shows that this line is composed for three different lines from different species, A1, A2 and A3. The A2 and A3 lines are associated with dose but grow also during drying of the sample and are probably due to 'cellulosic' components of the seed cover. The A1 line appears only when sample is dried and is probably associated with the quinones of the internal kernel coat. (author)

  15. Influence of sample treatment on ESR signal of irradiated citrus

    De Jesus, E.F.O.; Lopes, R.T. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia; Rossi, A.M. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

    1996-11-01

    EST spectra of the hard seed cover and kernel coating of irradiated orange and tangerine fruits were obtained under different sample drying conditions to analyze the effect of treatment on ESR line at g = 2.0033 (line A). The spectra shows almost the same lines that appear in stalks, achenes, seeds and skins of fresh fruit. The peak-to-peak intensity of the line A of the spectra shows a linear variation with dose in the range studied (up to 5 kGy) under controlled sample preparation. Q-band ESR spectra shows that this line is composed for three different lines from different species, A{sub 1}, A{sub 2} and A{sub 3}. The A{sub 2} and A{sub 3} lines are associated with dose but grow also during drying of the sample and are probably due to `cellulosic` components of the seed cover. The A{sub 1} line appears only when sample is dried and is probably associated with the quinones of the internal kernel coat. (author).

  16. Preliminary study of ESR dosimetry for nuclear accidents

    Electron spin resonance (RSE) technique was used to detect the ESR signal feature and the relations between signal intensity and irradiation dose of 0-50 Gy of 60Co γ ray for human bone, fingernail, hair and more than ten kinds of people carried materials such as materials from watch, clothes, plastic ball pen, cigarette and so on. The results showed that both bone and watch glass have a good linear relation between signal intensity and irradiation dose. The linear correlation factor γ is 0.995 for bone and 0.999 for watch glass. At room temperature, signal from human bone has excellent stability while watch glass has a decay of about 20% during 24 hours at 24 degree C. The decay rate of watch glass will fall down at lower temperature. The lower limit of detectable dose for these two materials is below 2 Gy. The results suggest that both human bone and watch glass can be applicable as ESR dosimeter materials for nuclear accidents. Other materials investigated in this work still have some problems to be solved for accidental dosimetric use

  17. Predicted signatures of pulsed reconnection in ESR data

    C. J. Davis

    Full Text Available Early in 1996, the latest of the European incoherent-scatter (EISCAT radars came into operation on the Svalbard islands. The EISCAT Svalbard Radar (ESR has been built in order to study the ionosphere in the northern polar cap and in particular, the dayside cusp. Conditions in the upper atmosphere in the cusp region are complex, with magnetosheath plasma cascading freely into the atmosphere along open magnetic field lines as a result of magnetic reconnection at the dayside magnetopause. A model has been developed to predict the effects of pulsed reconnection and the subsequent cusp precipitation in the ionosphere. Using this model we have successfully recreated some of the major features seen in photometer and satellite data within the cusp. In this paper, the work is extended to predict the signatures of pulsed reconnection in ESR data when the radar is pointed along the magnetic field. It is expected that enhancements in both electron concentration and electron temperature will be observed. Whether these enhancements are continuous in time or occur as a series of separate events is shown to depend critically on where the open/closed field-line boundary is with respect to the radar. This is shown to be particularly true when reconnection pulses are superposed on a steady background rate.

  18. ESR/alanine dosimetry applied to radiation processing

    The radiation processing of food products is specified in terms of absorbed dose, and processing quality is assessed on the basis of absorbed dose measurements. The validity of process quality control is highly dependent on the quality of the measurements and associated instrumentation; in this respect, dosimetry calibration by an Organization with official status provides an essential guarantee of validity to the quality control steps taken. The Laboratoire de Metrologie des Rayonnements Ionisants (L.M.R.I.) is the primary standards and evaluation laboratory approved by the Bureau National de Metrologie (B.N.M.), which is the French National Bureau of Standards. The LMRI implements correlation procedures in response to the various requirements which arise in connection with high doses and doserates. Such procedures are mainly based on ESR/alanine spectrometry, a dosimetry technique ideally suited to that purpose. Dosemeter geometry and design are tailored to operating conditions. Photon dosemeters consist of a detector material in powder or compacted form, and a wall with thickness and chemical composition consistent with the application. Electron dosemeters have a detector core of compacted alanine with thickness down to a few tenths of a millimeter. The ESR/alanine dosimetry technique, developed at LMRI is a flexible, reliable and accurate tool which effectively meets the various requirements arising in the field of reference dosimetry, where high doses and doserates are involved. (author)

  19. Attempts at refining system parameters for ESR measurements in shellfish

    The evaluation of ESR spectra for various species of shellfish may pose problems in cases, where the radiation dose was low. Difficulties are added by unspecific interference signals from manganese that vary in intensity. As such variations were even observed between the samples analyzed during this multilateral study (Nephrops norvegicus), which are likely to have the same geographical origin, they are probably closely linked to the age and degree of calcification of the shell. In spite of those difficulties, an attempt was made to achieve a reliable distinction between irradiated and non-irradiated samples by gradually increasing the microwave rate and simultaneously diminishing the modulation amplitude. The results obtained cannot be regarded as being of general value, as each sample had its specific individual reactions. The adjustment of the measuring parameters did not basically improve the quality of the ESR signal. We take the view that false-negative results cannot always be excluded in cases of low-dose irradiation and high manganic contents. (orig./vhe)

  20. Phase transitions of natural corals monitored by ESR spectroscopy

    Vongsavat, V. [Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Rajathevi, Bangkok 10400 (Thailand); Winotai, P. [Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Rajathevi, Bangkok 10400 (Thailand); Meejoo, S. [Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Rajathevi, Bangkok 10400 (Thailand)]. E-mail: scsmj@mahidol.ac.th

    2006-01-15

    The main purpose of this work is to present a systematic study of structure of marine exoskeletons, Acropora coral and its structural transformation upon heat treatments. The coralline sample was ground and characterized as powder throughout this work. Structural identifications of all samples have been confirmed using X-ray diffraction and IR spectroscopy. It was clearly found that the fresh specimen is made of aragonite, a common phase of the mineral CaCO{sub 3}. Thermal analyses, DSC and TGA were used to monitor structural and thermal decompositions and an irreversible solid-state phase transition from aragonite to calcite of the marine carbonate. Next, the coral powder was annealed at specific temperatures over the range 350-900 deg. C, and the effects of heat treatment on the structure of coralline samples were carefully studied by Rietveld refinement method. In addition, we have examined Mn{sup 2+} paramagnetic ions and free radicals present in the coral and changes of those upon heating by using ESR spectroscopy. The local environments of Mn{sup 2+} ions were verified from the calculated ESR spectra using appropriate spin Hamiltonian parameters, i.e. gyromagnetic tensor g , zero-field splitting D and hyperfine tensor A . This work reported structures and compositions as well as physical, chemical and thermal properties of the coralline material upon heat treatments qualitatively and quantitatively.

  1. Phase transitions of natural corals monitored by ESR spectroscopy

    The main purpose of this work is to present a systematic study of structure of marine exoskeletons, Acropora coral and its structural transformation upon heat treatments. The coralline sample was ground and characterized as powder throughout this work. Structural identifications of all samples have been confirmed using X-ray diffraction and IR spectroscopy. It was clearly found that the fresh specimen is made of aragonite, a common phase of the mineral CaCO3. Thermal analyses, DSC and TGA were used to monitor structural and thermal decompositions and an irreversible solid-state phase transition from aragonite to calcite of the marine carbonate. Next, the coral powder was annealed at specific temperatures over the range 350-900 deg. C, and the effects of heat treatment on the structure of coralline samples were carefully studied by Rietveld refinement method. In addition, we have examined Mn2+ paramagnetic ions and free radicals present in the coral and changes of those upon heating by using ESR spectroscopy. The local environments of Mn2+ ions were verified from the calculated ESR spectra using appropriate spin Hamiltonian parameters, i.e. gyromagnetic tensor g , zero-field splitting D and hyperfine tensor A . This work reported structures and compositions as well as physical, chemical and thermal properties of the coralline material upon heat treatments qualitatively and quantitatively

  2. Radiation-induced defects in magnesium lactate as ESR dosimeter

    Hassan, G M; Takaki, S

    1999-01-01

    Magnesium lactate (Mg-lactate: (CH sub 3 CH(OH)COO) sub 2 Mg), magnesium lactate doped with lithium lactate (Mg(Li)-lactate) and nominal pure lithium lactate (CH sub 3 CH(OH)COOLi) doped with Mg-lactate (Li(Mg)-lactate) were irradiated by gamma-rays to study radicals for materials of radiation dosimeter with electron spin resonance (ESR). Quartet spectra were ascribed to lactate radicals in Mg-lactate and Li(Mg)-lactate with the spectroscopic splitting factors (g-factor) of 2.0032+-0.004 and 2.0029+-0.004 and the intensity ratio of 1:3:3:1 due to the hyperfine coupling constants of (A/g beta) of 1.92+-0.06 and 1.82+-0.06 mT, respectively. The response to gamma-ray dose and the thermal stability as well as the effect of UV-illumination have been studied to establish this material as an ESR dosimeter. The number of free radicals per 100 eV (G-value) was obtained to be 1.15+-0.32, 1.35+-0.35, 0.46+-0.14 and 0.78+-0.24 for Mg-lactate, Mg(Li)-lactate, Li-lactate and Lie(Mg)-lactate, respectively. Thermoluminescenc...

  3. Acoustic emission

    This paper is related to our activities on acoustic emission (A.E.). The work is made with different materials: metals and fibre reinforced plastics. At present, acoustic emission transducers are being developed for low and high temperature. A test to detect electrical discharges in electrical transformers was performed. Our experience in industrial tests to detect cracks or failures in tanks or tubes is also described. The use of A.E. for leak detection is considered. Works on pattern recognition of A.E. signals are also being performed. (Author)

  4. Investigation of the momentum compaction factor of the ESR thorough Schottky mass measurements

    Yan, X. L.; Bosch, F.; Litvinov, Yu A.; Nolden, F.; Steck, M.; Tu, X. L.; Xu, H. S.; Zhou, X. H.; Zhang, Y. H.

    2015-11-01

    Schottky mass spectrometry was applied to stored and cooled neutron-deficient 152Sm projectile fragments at the experimental storage ring (ESR) facility at GSI Darmstadt, Germany. 311 different nuclides were identified by means of their revolution frequency spectra. The measured frequencies were used to investigate the shape of the momentum-compaction-factor of the ESR.

  5. Schottky diagnosis and BTF measurements on cooled beams in the heavy ion storage ring ESR

    This report describes a non-destructive diagnosis system installed at the ESR (Experimental Storage Ring). Using this system a variety of beam and machine parameters can be evaluated. It turned out to be a very important diagnostic tool during all beam-times of the ESR. (orig./HSI)

  6. Improvement of the ESR detection of irradiated food containing cellulose employing a simple extraction method

    Fruit may be irradiated at rather low doses, below 1 kGy in combination treatments or for quarantine purposes. To improve the ESR detection sensitivity of irradiated fruit de Jesus et al. (Int. J. Food Sci. Technol. 34 (1999) 173.) proposed extracting the fruit pulp with 80% ethanol and measuring the residue with ESR using low power (0.25 mW) for detection of 'cellulosic' radicals. An improvement in ESR sensitivity using the extraction procedure could be confirmed in this paper for strawberries and papayas. In most cases, a radiation dose of 0.5 kGy could be detected in both fruits even after 2-3 weeks storage. In addition, some herbs and spices were also tested, but only for a few of them the ESR detection of the 'cellulosic' signal was improved by previous alcoholic extraction. As an alternative to ESR measurements, other detection methods like DNA Comet Assay and thermoluminescence were also tested

  7. Relaxation behavior of radicals produced in irradiated black pepper under various moisture conditions by ESR

    Black pepper is easy to be contaminated by microorganism and often processed to γ-irradiation. ESR has been used for the detection of radicals induced in irradiated spices. Using ESR, we revealed the effects of moisture condition during storage of irradiated black pepper on the saturation behavior of ESR signal. The ESR spectrum of black pepper consists of a broad sextet centered at g=2.0, a singlet as same g-value and a singlet at g=4.0. The irradiation causes two new signals, one is the strong and sharp singlet signal at g=2.0 and the other is the side signal. We found that the signal intensity originated by the radicals of black pepper with and without radiation decayed in the high humidity condition during storage. The ESR signal intensity of irradiated black pepper decayed during storage and showed almost the same intensity level as that of non-irradiated black pepper during storage. (author)

  8. The use of different methods for rapid determination of the ESR induces DAS28 misclassification in clinical practice.

    Maas, A. van der; Ende, C.H.M. van den; Eerd, J. van; Fransen, J.; Broeder, A. den

    2010-01-01

    OBJECTIVES: Monitoring of disease activity using DAS28 is more effective than routine RA care, but the ESR measurement is time consuming. Alternative rapid ESR determination methods can be used but effects on DAS28 classification are unknown. METHODS: Alternative rapid ESR methods, including the Sta

  9. ESR spectra of VOCl2 solutions in alcohols

    ESR spectra of VOCl2 solutions in ROH(R - Me, Et, i-Pr) absolute alcohols are studied. It is stated that [VOCl2(ROH)3](1) molecular form is the basic complex form, there with two Cl atoms are arranged in a plane perpendicular to V=0 bond. In MeOH 10-15% of the second [VOCl(MeOH)4]+ (2) form is also present. Under HCl effect on these solutions a step-by-step replacement of ROH with Cl atoms takes place. In complex 2 chloride-ion occupies equatorial position. Formation of 2 under transition to the solution of solid (1) is due to efficient solvolytic activity of MeOH as compared to other alcohols. Vice versa, dissolution of crystalline [VOCl(i-PrOH)4]+Cl- in i-PrOH is followed by transition to molecular forms

  10. ESR studies of heat denaturation in Cu myoglobin complexes

    An investigation is made on the behaviour of Cu2+ and Fe3+ in copper doped myoglobin, subjected to heat treatment. ESR is observed at X-band. The amplitude of the g = 5.9 line of the high spin F3+ in met-myoglobin is studied as a function of the temperature of the heat treatment, the pH and the length of time of exposure to the heat treatment. These experiments are performed for both the pure protein and for the copper-myoglobin complex, at pH between 5 and 8.5. Results concerning the decrease of the amplitude of Fe3+ high spin signal are discussed in comparison with Hollocher's results in hemoglobin. The Cu spectra obtained are interpreted, with the aid of a computer program, Kivelson and Neiman's results being used to analyse the authors data

  11. Titanocene(III) pseudohalides: an ESR and structural study

    Křižan, Martin; Honzíček, Jan; Vinklárek, Jaromír; Růžičková, Zdeňka; Erben, Milan

    2014-01-01

    A series of complexes of the type [Ti(′Cp)2Y] {′Cp = η5-C5H5 (Cp), η5-C5H4SiMe3 (SiCp), η5-1,3-C5H3(Me3Si)2 (Si2Cp); Y = Cl−, CN−, NCS−, NCSe−, dicyanamide (dca), tricyanomethanide (tcm) and 1,2,3,4-thiatriazol-5-thiolate (ttt)} were prepared and studied by ESR spectroscopy. Ring-substituted compounds [Ti(SiCp)2Cl], [Ti(Si2Cp)2Cl], [Ti(SiCp)2CN] and [Ti(Si2Cp)2CN] dissolved in coordinating solvents exist in an equilibrium with solvated species. The thiatriazolthiolate ligand in complexes [Ti(...

  12. Characterization of structure and thermophysical properties of three ESR slags

    Plotkowski, A.; deBarbadillo, J.; Krane, Matthew J. M.

    2016-07-01

    The structure and properties of electroslag remelting (ESR) slags were characterized. Slags samples of three compositions were obtained from industrial remelting processes at Special Metals Corporation and from casting in a laboratory vacuum induction melter. The structure of the slag samples was observed using optical and electron microscopy, and phases were identified and their relative amounts quantified using X-ray diffraction. Laser flash thermal diffusivity, density, and differential scanning calorimetry measurements for specific heat were performed to determine the bulk thermal conductivity of the samples. Sample porosity was measured as a function of depth using a serial sectioning technique, and a onedimensional computational model was developed to estimate the thermal conductivity of the fully dense slags. These results are discussed in context with previous studies, and opportunities for future research are identified. AFRL Case Number: 88ABW-2015-1871.

  13. Ionosphere and Thermosphere above EISCAT-ESR during IPY

    Blelly, Pierre-Louis; Alcaydé, Denis; van Eyken, Antony P.

    2010-05-01

    In a previous study we showed that, with the use of 13-moment, parallel, two-ion (atomic and molecular) energy equations to fit the full Incoherent Scatter (IS) profiles along the magnetic field, it was possible to overcome two major difficulties for a proper analysis of the ion energy budget in the F1- and F2-regions, namely getting accurate estimates of the ion composition in the F1-region, and then being able to separate the relative contributions from the neutral atmosphere and from frictional heating. It was shown that this "full profile" method is sufficiently robust for routine use, even for periods with moderately high convection electric fields. In the present study, the method is applied to the three-year IS dataset recorded at the EISCAT Svalbard Radar (ESR) during the International Polar Year (IPY ) period (March. 2007 - Sept. 2009), and the results are used to study long-term variations in the ionosphere and neutral atmosphere. For that purpose, we choose to use a similar approach to that used in the MSIS models for determining the time variability of the measured/inferred parameters and built what we call ESR-IPY models of ionospheric and atmospheric parameters. After discussing a case-day example for which the quality of the global models fits is shown, the long term behavior (year-to-year, seasonal, solar flux and geomagnetic activity) is shown and contrasted, when available, with existing standard models such as MSIS and IRI. Key words. Polar cap ionosphere, Ionosphere/atmosphere interactions, Modelling and forecasting

  14. Gamma dose mapping fuelling machine at Dhruva reactor using ESR dosimetry

    Electron Spin Resonance (ESR) technique is useful in quantifying the radiation induced radicals with unpaired electrons, as a measure of irradiation dose delivered, thereby has application in the field of dosimetry. The ESR dosimetry has a few reported dosimeters, Alanine, Lithium Carbonate are commonly used to elucidate dosimetric response by the ESR spectrometer. We have identified, reported the ESR dosimetric properties of glass powder and hence, glass powder was used along with Alanine to calibrate its response and for dose mapping studies. The fuelling machine at Dhruva reactor during the hot rod handling has points that exhibit high radiation field thereby conventional dosimetric study is not feasible. Since ESR dosimetry has viability for high dose ranges, it was decided to carry out gamma dose mapping of select areas of the fuelling machine facility. The gamma dose mapping results at various places of fuelling machine of the reactor was estimated, Since the irradiation time for the either set of samples is known, the radiation fields could be worked out at the various points as 40-60 R/h, and the dosimetric response of alanine and glass powder samples were found to tally within ± 10%. ESR dosimetry has been useful in the dose mapping of high radiation areas, and the new ESR dosimetric material-glass powder, has nearly the same dose response as that of alanine

  15. ESR technique for noninvasive way to quantify cyclodextrins effect on cell membranes

    Research highlights: → ESR: a new tool for cyclodextrins study on living cells. → Cholesterol and phospholipid extraction by Rameb in a dose- and time-dependent way. → Extracted phospholipids and cholesterol form stable aggregates. → ESR spectra show that lipid rafts are damaged by Rameb. → Quantification of the cholesterol extraction on cell membranes in a noninvasive way. -- Abstract: A new way to study the action of cyclodextrin was developed to quantify the damage caused on cell membrane and lipid bilayer. The Electron Spin Resonance (ESR) spectroscopy was used to study the action of Randomly methylated-beta-cyclodextrin (Rameb) on living cells (HCT-116). The relative anisotropy observed in ESR spectrum of nitroxide spin probe (5-DSA and cholestane) is directly related to the rotational mobility of the probe, which can be further correlated with the microviscosity. The use of ESR probes clearly shows a close correlation between cholesterol contained in cells and cellular membrane microviscosity. This study also demonstrates the Rameb ability to extract cholesterol and phospholipids in time- and dose-dependent ways. In addition, ESR spectra enabled to establish that cholesterol is extracted from lipid rafts to form stable aggregates. The present work supports that ESR is an easy, reproducible and noninvasive technique to study the effect of cyclodextrins on cell membranes.

  16. ESR technique for noninvasive way to quantify cyclodextrins effect on cell membranes

    Grammenos, A., E-mail: A.Grammenos@ulg.ac.be [Laboratory of Biomedical Spectroscopy, Department of Physics, B5, University of Liege, Sart-Tilman (Belgium); Mouithys-Mickalad, A. [Center of Oxygen, Research and Development (CORD), Department of Chemistry, B6a, University of Liege, Sart-Tilman (Belgium); Guelluy, P.H.; Lismont, M. [Laboratory of Biomedical Spectroscopy, Department of Physics, B5, University of Liege, Sart-Tilman (Belgium); Piel, G. [Laboratory of Pharmaceutical Technology, Department of Pharmacy, CHU, B36, University of Liege, 1 Av. de l' Hopital (Belgium); Hoebeke, M. [Laboratory of Biomedical Spectroscopy, Department of Physics, B5, University of Liege, Sart-Tilman (Belgium)

    2010-07-30

    Research highlights: {yields} ESR: a new tool for cyclodextrins study on living cells. {yields} Cholesterol and phospholipid extraction by Rameb in a dose- and time-dependent way. {yields} Extracted phospholipids and cholesterol form stable aggregates. {yields} ESR spectra show that lipid rafts are damaged by Rameb. {yields} Quantification of the cholesterol extraction on cell membranes in a noninvasive way. -- Abstract: A new way to study the action of cyclodextrin was developed to quantify the damage caused on cell membrane and lipid bilayer. The Electron Spin Resonance (ESR) spectroscopy was used to study the action of Randomly methylated-beta-cyclodextrin (Rameb) on living cells (HCT-116). The relative anisotropy observed in ESR spectrum of nitroxide spin probe (5-DSA and cholestane) is directly related to the rotational mobility of the probe, which can be further correlated with the microviscosity. The use of ESR probes clearly shows a close correlation between cholesterol contained in cells and cellular membrane microviscosity. This study also demonstrates the Rameb ability to extract cholesterol and phospholipids in time- and dose-dependent ways. In addition, ESR spectra enabled to establish that cholesterol is extracted from lipid rafts to form stable aggregates. The present work supports that ESR is an easy, reproducible and noninvasive technique to study the effect of cyclodextrins on cell membranes.

  17. Acoustic lenses

    Acoustic lenses focus ultrasound to produce pencil-like beams with reduced near fields. When fitted to conventional (flat-faced) transducers, such lenses greatly improve the ability to detect and size defects. This paper describes a program developed to design acoustic lenses for use in immersion or contact inspection, using normal or angle beam mode with flat or curved targets. Lens surfaces are circular in geometry to facilitate machining. For normal beam inspection of flat plate, spherical or cylindrical lenses are used. For angle beam or curved surface inspections, a compound lens is required to correct for the extra induced aberration. Such a lens is aspherical with one radius of curvature in the plane of incidence, and a different radius of curvature in the plane perpendicular to the incident plane. The resultant beam profile (i.e., location of the acoustic focus, beam diameter, 6 dB working range) depends on the degree of focusing and the transducer used. The operating frequency and bandwidth can be affected by the instrumentation used. Theoretical and measured beam profiles are in good agreement. Various applications, from zone focusing used for defect sizing in thick plate, to line focusing for pipe weld inspection, are discussed

  18. Estrogen Receptor Alpha (ESR1-Dependent Regulation of the Mouse Oviductal Transcriptome.

    Katheryn L Cerny

    Full Text Available Estrogen receptor-α (ESR1 is an important transcriptional regulator in the mammalian oviduct, however ESR1-dependent regulation of the transcriptome of this organ is not well defined, especially at the genomic level. The objective of this study was therefore to investigate estradiol- and ESR1-dependent regulation of the transcriptome of the oviduct using transgenic mice, both with (ESR1KO and without (wild-type, WT a global deletion of ESR1. Oviducts were collected from ESR1KO and WT littermates at 23 days of age, or ESR1KO and WT mice were treated with 5 IU PMSG to stimulate follicular development and the production of ovarian estradiol, and the oviducts collected 48 h later. RNA extracted from whole oviducts was hybridized to Affymetrix Genechip Mouse Genome 430-2.0 arrays (n = 3 arrays per genotype and treatment or reverse transcribed to cDNA for analysis of the expression of selected mRNAs by real-time PCR. Following microarray analysis, a statistical two-way ANOVA and pairwise comparison (LSD test revealed 2428 differentially expressed transcripts (DEG's, P < 0.01. Genotype affected the expression of 2215 genes, treatment (PMSG affected the expression of 465 genes, and genotype x treatment affected the expression of 438 genes. With the goal of determining estradiol/ESR1-regulated function, gene ontology (GO and bioinformatic pathway analyses were performed on DEG's in the oviducts of PMSG-treated ESR1KO versus PMSG-treated WT mice. Significantly enriched GO molecular function categories included binding and catalytic activity. Significantly enriched GO cellular component categories indicated the extracellular region. Significantly enriched GO biological process categories involved a single organism, modulation of a measurable attribute and developmental processes. Bioinformatic analysis revealed ESR1-regulation of the immune response within the oviduct as the primary canonical pathway. In summary, a transcriptomal profile of estradiol- and

  19. Estrogen Receptor Alpha (ESR1)-Dependent Regulation of the Mouse Oviductal Transcriptome.

    Cerny, Katheryn L; Ribeiro, Rosanne A C; Jeoung, Myoungkun; Ko, CheMyong; Bridges, Phillip J

    2016-01-01

    Estrogen receptor-α (ESR1) is an important transcriptional regulator in the mammalian oviduct, however ESR1-dependent regulation of the transcriptome of this organ is not well defined, especially at the genomic level. The objective of this study was therefore to investigate estradiol- and ESR1-dependent regulation of the transcriptome of the oviduct using transgenic mice, both with (ESR1KO) and without (wild-type, WT) a global deletion of ESR1. Oviducts were collected from ESR1KO and WT littermates at 23 days of age, or ESR1KO and WT mice were treated with 5 IU PMSG to stimulate follicular development and the production of ovarian estradiol, and the oviducts collected 48 h later. RNA extracted from whole oviducts was hybridized to Affymetrix Genechip Mouse Genome 430-2.0 arrays (n = 3 arrays per genotype and treatment) or reverse transcribed to cDNA for analysis of the expression of selected mRNAs by real-time PCR. Following microarray analysis, a statistical two-way ANOVA and pairwise comparison (LSD test) revealed 2428 differentially expressed transcripts (DEG's, P < 0.01). Genotype affected the expression of 2215 genes, treatment (PMSG) affected the expression of 465 genes, and genotype x treatment affected the expression of 438 genes. With the goal of determining estradiol/ESR1-regulated function, gene ontology (GO) and bioinformatic pathway analyses were performed on DEG's in the oviducts of PMSG-treated ESR1KO versus PMSG-treated WT mice. Significantly enriched GO molecular function categories included binding and catalytic activity. Significantly enriched GO cellular component categories indicated the extracellular region. Significantly enriched GO biological process categories involved a single organism, modulation of a measurable attribute and developmental processes. Bioinformatic analysis revealed ESR1-regulation of the immune response within the oviduct as the primary canonical pathway. In summary, a transcriptomal profile of estradiol- and ESR1

  20. ESR studies of high-energy phosphorus-ion implanted synthetic diamond crystals

    Isoya, J. [University of Library and Information Science, Tsukuba, Ibaraki (Japan); Kanda, H.; Morita, Y.; Ohshima, T.

    1997-03-01

    Phosphorus is among potential n-type dopants in diamond. High pressure synthetic diamond crystals of type IIa implanted with high energy (9-18 MeV) phosphorus ions have been studied by using electron spin resonance (ESR) technique. The intensity and the linewidth of the ESR signal attributed to the dangling bond of the amorphous phase varied with the implantation dose, suggesting the nature of the amorphization varies with the dose. The ESR signals of point defects have been observed in the low dose as-implanted crystals and in the high dose crystals annealed at high temperature and at high pressure. (author)

  1. Flux properties in Bi-2212 single crystals studied by spin-probe ESR

    Nishida, Akihiko; Taka, Chihiro; Yasuda, Takashi; Horai, Kazumi

    2000-07-01

    Flux properties in Bi 2Sr 2CaCu 2O 8+ x (Bi-2212) single crystals are studied by spin-probe method. ESR line widths of a very thin layer of DPPH free radical on the surface of the crystals begin to increase upon the superconducting transitions. At further low temperatures below irreversibility lines, distinct hysteresis is observed between ESR profiles for field increase and decrease. The resonance fields and intensities also indicate characteristic changes. Close correlations between ESR anomalies and vortex behaviors are discussed, comparing results of as-grown and optimally doped crystals.

  2. Spin Labeling ESR Investigation of Covalently Bound Residues in Soil

    Aleksandrova, Olga; Steinhoff, Heinz-Juergen; Klasmeier, Joerg; Schulz, Marcus; Matthies, Michael

    2013-04-01

    Organic xenobiotic chemicals, such as pesticides, biocides and veterinary pharmaceuticals, interact with soil, which results in the simultaneous formations of metabolites, mineralization products, and bound or non-extractable residues (NER). Substances or metabolites with reactive functional groups, such as aniline or phenol, have a tendency to give a larger proportion of NER. Despite numerous studies on NER, the majority of their chemical structures is still unknown. Reversible sequestration and irreversible formation of NER were also observed for veterinary antibiotic pharmaceuticals, after their application to soil with and without manure. For this purpose, we hypothesized a key role of specific functional groups of soil contaminants, via which contaminants are covalently bound to soil constituents, and advance a method of spin labeling ESR investigation of reaction products using a membrane method. Spin labels (SL) represent chemically stable paramagnetic molecules used as molecular labels and molecular probes for testing the covalent binding, structural properties, and molecular mobility of different physical, chemical, and biological systems. In the case of covalent binding of SL, their ESR spectra become broadened. We used stable nitroxide radicals (NR) as SL. These radicals modeled organic chemical contaminants and differed only in one functional group. The paramagnetic SL 4-Amino Tempo (4-amino-2,2,6,6-tetramethyl-1-piperidinylox) differed from Tempo (2,2,6,6-Tetramethylpiperidinooxy) in a substituent at the para-position of the piperidine ring, whereas Aniline Tempo (1-Piperidinyloxy, 2,2,6,-tetramethyl, 6-Aniline) differed from Tempo in an Aniline substituting one CH3 functional group. Before experimental analysis, we tested temporal changes in the concentration of both NR incubated with soil and found that the life-times of them in soil exceeded 3 days. We contaminated and labeled soil samples with NR, adding to soil the aqueous solution, which already

  3. DETECTION OF SOME IRRADIATED NUTS BY ELECTRON SPIN RESONANCE (ESR) TECHNIQUE

    The present investigation was carried out to establish the electron spin resonance (ESR) detection method for identifying irradiated nuts (almond and pistachio). Samples were irradiated with 2, 4 and 6 kGy and stored at room temperature (25± 20C) for six months to study the possibility of detecting its previous irradiation treatments by ESR spectroscopy. Analysis was carried out just after irradiation treatment and during ambient storage period. The ESR signal intensities of irradiated samples were markedly increased correspondingly with irradiation dose as a result of free radicals generated by gamma irradiation so, all irradiated samples under investigation could be differentiated from non-irradiated ones immediately after irradiation treatment. The decay in radicals responsible of ESR signals showed the identification of irradiated almond (shell or edible part) and pistachio (edible part) was impossible after six months of ambient storage

  4. Combined TL and 10B-alanine ESR dosimetry for BNCT.

    Bartolotta, A; D'Oca, M C; Lo Giudice, B; Brai, M; Borio, R; Forini, N; Salvadori, P; Manera, S

    2004-01-01

    The dosimetric technique described in this paper is based on electron spin resonance (ESR) detectors using an alanine-boric compound acid enriched with (10)B, and beryllium oxide thermoluminescent (TL) detectors; with this combined dosimetry, it is possible to discriminate the doses due to thermal neutrons and gamma radiation in a mixed field. Irradiations were carried out inside the thermal column of a TRIGA MARK II water-pool-type research nuclear reactor, also used for Boron Neutron Capture therapy (BNCT) applications, with thermal neutron fluence from 10(9) to 10(14) nth cm(-2). The ESR dosemeters using the alanine-boron compound indicated ESR signals about 30-fold stronger than those using only alanine. Moreover, a negligible correction for the gamma contribution, measured with TL detectors, almost insensitive to thermal neutrons, was necessary. Therefore, a simultaneous analysis of our TL and ESR detectors allows discrimination between thermal neutron and gamma doses, as required in BNCT. PMID:15353720

  5. ESR characterization of irradiated peony root, a medicinal plant containing crystalline sugars

    The ESR spectral property of irradiated peony root was studied during development of a system for detection of irradiated medicinal plants containing crystalline sugars. The plant had a weak ESR signal near g=2.005 before electron beam-irradiation. After 10 kGy irradiation, the line shape became broader and cellulose-like signal: a pair of lines at 6 mT across the center signal near g=2.005 and sugar-like spectrum: a broader line with more than 6 mT of overall spectrum width, was observed. The ESR intensity decreased considerably at 30 days post-irradiation and was stable thereafter. The stable ESR line shape of irradiated peony root resembled that of irradiated sucrose, and the intensity 30 days post-irradiation increased linearly as a function of sucrose content. This result shows that the radical concentration correlation to sucrose content in irradiated plant material is predictable. (author)

  6. ESR investigation of L-α-alanine and sucrose radicals produced by heavy-ion irradiation

    We investigated sucrose and L-α-alanine radicals produced by heavy ion irradiation with various LETs (linear energy transfer). The impact of the heavy ions on the samples produced stable free radicals, which were analyzed by ESR (electron spin resonance). The obtained spectral patterns were the same as those for carbon (C), neon (Ne), and silicon (Si) ion irradiations. The absorbed dose dependences for the irradiated sucrose and alanine samples were examined. The ESR response has a linear relation with the absorbed dose for both compounds. In addition, the total spin concentration obtained by heavy-ion irradiation correlated logarithmically with the LET. Let Qualitative ESR analyses showed that the production of sucrose and alanine radical depended on both different particle irradiation and the LET under the same dose. Thus, the present ESR results imply that sucrose together with L-α-alanine can be used to investigate radical production processes induced by ionizing particles. (author)

  7. Identification of irradiated sage tea ( Salvia officinalis L.) by ESR spectroscopy

    Tepe Çam, Semra; Engin, Birol

    2010-04-01

    The use of electron spin resonance (ESR) spectroscopy to accurately distinguish irradiated from unirradiated sage tea was examined. Before irradiation, sage tea samples exhibit one asymmetric singlet ESR signal centered at g=2.0037. Besides this central signal, two weak satellite signals situated about 3 mT left and right to it in radiation-induced spectra. Irradiation with increasing doses caused a significant increase in radiation-induced ESR signal intensity at g=2.0265 (the left satellite signal) and this increase was found to be explained by a polynomial varying function. The stability of that radiation-induced ESR signal at room temperature was studied over a storage period of 9 months. Also, the kinetic of signal at g=2.0265 was studied in detail over a temperature range 313-353 K by annealing samples at different temperatures for various times.

  8. Identification of irradiated sage tea (Salvia officinalis L.) by ESR spectroscopy

    The use of electron spin resonance (ESR) spectroscopy to accurately distinguish irradiated from unirradiated sage tea was examined. Before irradiation, sage tea samples exhibit one asymmetric singlet ESR signal centered at g=2.0037. Besides this central signal, two weak satellite signals situated about 3 mT left and right to it in radiation-induced spectra. Irradiation with increasing doses caused a significant increase in radiation-induced ESR signal intensity at g=2.0265 (the left satellite signal) and this increase was found to be explained by a polynomial varying function. The stability of that radiation-induced ESR signal at room temperature was studied over a storage period of 9 months. Also, the kinetic of signal at g=2.0265 was studied in detail over a temperature range 313-353 K by annealing samples at different temperatures for various times.

  9. Identification of irradiated sage tea (Salvia officinalis L.) by ESR spectroscopy

    Tepe Cam, Semra, E-mail: stepe06@gmail.co [Gazi University, Faculty of Medicine, Biophysics Department, 06500 Besevler, Ankara (Turkey); Engin, Birol [Turkish Atomic Energy Authority, Saraykoey Nuclear Research and Training Center, 06983 Ankara (Turkey)

    2010-04-15

    The use of electron spin resonance (ESR) spectroscopy to accurately distinguish irradiated from unirradiated sage tea was examined. Before irradiation, sage tea samples exhibit one asymmetric singlet ESR signal centered at g=2.0037. Besides this central signal, two weak satellite signals situated about 3 mT left and right to it in radiation-induced spectra. Irradiation with increasing doses caused a significant increase in radiation-induced ESR signal intensity at g=2.0265 (the left satellite signal) and this increase was found to be explained by a polynomial varying function. The stability of that radiation-induced ESR signal at room temperature was studied over a storage period of 9 months. Also, the kinetic of signal at g=2.0265 was studied in detail over a temperature range 313-353 K by annealing samples at different temperatures for various times.

  10. ESR spectrometric characterization of the methyl viologen dosimeter in poly(vinyl alcohol) film

    Nishimoto, Sei-Ichi; Ye, Mu; Lu, Yiqun; Kawamura, Takashi; Kagiya, Tsutomu

    A dosimeter of poly(vinyl alcohol) (PVA) film containing methyl viologen dichloride (MV 2+ (Cl -) 2) was characterized by means of ESR and u.v. spectrometries. γ-irradiation of the MV 2+-PVA dosimeter induced one-electron reduction of MV 2+· to thecation radical (MV +), thus giving rise to blue coloration. The resulting MV +· showed an ESR signal with a g-factor of 2.0031. The yield of MV +· at a given radiation dose was estimated from duplicate integral of the ESR first-derivative spectra by reference to 1,1'-diphenyl-2-picrylhydrazyl (DPPH). The yield of MV +· thus estimated increased linearly with increasing the radiation dose up to about 1.4 Mrad. The ESR spectrometry of MV +· showed a linear correlation with the u.v. spectrometric method reported previously.

  11. ESR and cathodoluminescence studies of radiation defects in clays and quartz fromsome U deposits

    ブランディーヌ; 小室 光世; 中嶋, 悟; 永野 哲志; 正木 信行; 林 久人

    1992-01-01

    Rock samples from different world U deposits mainly in sedimentary rocks have been studied by Electron Spin Resonancc (ESR) spectroscopy and Cathodoluminescence (CL) measurement in order to characterize radiation damage centers in clays and quartz. The presence of kaolinite-like radiation centers ill ESR spectra in some of the samples containing kaolin group minerals suggests that this type of radiation damages can be used as an indicator of U behavior during supergene and hydrothermal altera...

  12. NMR and ESR studies of an undoped conjugated polymer: poly-p-phenylene

    Magnetic property measurements (ESR, NMR and dynamic nuclear polarization (DNP)) of an undoped aromatic conjugated polymer, poly-p-phenylene, have been improved. This analysis was performed on samples synthesized in three different ways. ESR studies at 10 GHz and 35 GHz show that paramagnetic defects strongly depend on the preparation mode and on the thermal treatment of the polymer. The NMR results suggest that two relaxation mechanisms occur in these materials. Moreover, DNP measurements indicate that the paramagnetic species are localized. (Auth.)

  13. ESR spectroscopy dating of recently excavated archaeological bone samples from Kottapuram site using gamma irradiation

    The study of radiation defects created in biomaterials such as bones can be used in dating with importance to paleontology and archaeology. Electron Spin Resonance Spectroscopy is applied to estimate the age of bones excavated from the archaeological site at Kottapuram in Kerala state south India. Gamma irradiated samples were analyzed by ESR spectrometry in order to obtain the growth curve and showed ESR behavior. The age of the bone samples were determined. (author)

  14. The influence of measurement and storage conditions on alanine ESR dosimeters

    Alanine has several desirable properties as an ESR dosemeter e.g. tissue equivalence, low fading and an approximately linear response for doses up to 10 kGy. This work reports on a simple system to produce the alanine dosemeter, the signal intensity for a range of doses and energies, and the effect of the air humidity and the spectrometer settings on the ESR signal. (Author)

  15. Microwave frequency modulation in continuous-wave far-infrared ESR utilizing a quasioptical reflection bridge

    Nafradi, Balint; Gaal, Richard; Feher, Titusz; Forro, Laszlo

    2008-01-01

    We report the development of the frequency-modulation (FM) method for measuring electron spin resonance (ESR) absorption in the 210-420 GHz frequency range. We demonstrate that using a high-frequency ESR spectrometer without resonating microwave components enables us to overcome technical difficulties associated with the FM method due to nonlinear microwave-elements, without sacrificing spectrometer performance. FM was achieved by modulating the reference oscillator of a 13 GHz Phase Locked D...

  16. ESR-Tree: a dynamic index for multi-dimensional objects%ESR-Tree:一种多维对象的动态索引方法

    徐焕; 林坤辉

    2005-01-01

    在研究SR-tree(Sphere/Rectangle-tree)和X-tree(eXtended node tree)的结构与性能的基础上,针对SR-tree分裂算法的不足,改进了分裂算法,结合两者的优点,设计了一种新的多维索引结构ESR-tree(Extended SR-tree).实验表明,随着数据量和维数的增多,ESR-tree的性能要优于SR-tree和X-tree.

  17. Chemical origin of the native ESR signals in thermally treated enamel and dentin

    Heating, crushing and exposure of dental enamel to sunlight and UV radiation can introduce paramagnetic signals similar to those following exposure to ionizing radiation. The objective of this work is to use infrared and electron spin resonance (ESR) spectra to study thermally treated enamel and dentin, and identify the chemical radical or mechanisms that produce these ambiguous ESR signals. Non-irradiated bovine teeth were used. ESR spectroscopy was performed in the X band and the infrared spectroscopy was performed on a FTIR spectrometer operating between 4000 cm-1 and 400 cm-1. The results show ESR signals in dentin heated at temperatures between 100 deg. C and 1000 deg. C and in enamel heated at temperatures ranging from 250 deg. C to 1000 deg. C. The ESR signal formed after heat treatment below 400 deg. C could be assigned to degradation products of the organic material, while the ESR signals that predominate in tissues heated between 500 deg. C and 900 deg. C show a maximum amplitude at 750 deg. C and could be assigned to the cyanate ion (NCO-)

  18. Diffusion studies on permeable nitroxyl spin probes through bilayer lipid membranes: A low frequency ESR study

    Meenakumari, V.; Utsumi, Hideo; Ichikawa, Kazuhiro; Yamada, Ken-ichi; Hyodo, Fuminori; Jawahar, A.; Benial, A. Milton Franklin

    2015-06-01

    Electron spin resonance (ESR) studies were carried out for permeable 2mM 14N-labeled deutrated 3 Methoxy carbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL) in pure water and 1mM, 2mM, 3mM, 4mM concentration of 14N-labeled deutrated MC-PROXYL in 400mM concentration of liposomal solution by using a 300 MHz ESR spectrometer. The ESR parameters such as linewidth, hyperfine coupling constant, g-factor, partition parameter and permeability were reported for these samples. The line broadening was observed for the nitroxyl spin probe in the liposomal solution. The line broadening indicates that the high viscous nature of the liposomal solution. The partition parameter and permeability values indicate the maximum diffusion of nitroxyl spin probes in the bilayer lipid membranes at 2 mM concentration of nitroxyl radical. This study illustrates that ESR can be used to differentiate between the intra and extra- membrane water by loading the liposome vesicles with a lipid-permeable nitroxyl spin probe. From the ESR results, the spin probe concentration was optimized as 2mM in liposomal solution for ESR phantom studies/imaging, invivo and invitro experiments.

  19. Diffusion studies on permeable nitroxyl spin probes through bilayer lipid membranes: A low frequency ESR study

    Meenakumari, V.; Benial, A. Milton Franklin, E-mail: miltonfranklin@yahoo.com [Department of Physics, NMSSVN College, Nagamalai, Madurai-625019, Tamilnadu (India); Utsumi, Hideo; Ichikawa, Kazuhiro; Yamada, Ken-ichi [Department of Bio-functional Science, Kyushu University, Fukuoka (Japan); Hyodo, Fuminori [Innovation Center for Medical Redox Navigation, Kyushu University, Fukuoka (Japan); Jawahar, A. [Department of Chemistry, NMSSVN College, Nagamalai, Madurai-625019, Tamilnadu (India)

    2015-06-24

    Electron spin resonance (ESR) studies were carried out for permeable 2mM {sup 14}N-labeled deutrated 3 Methoxy carbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL) in pure water and 1mM, 2mM, 3mM, 4mM concentration of 14N-labeled deutrated MC-PROXYL in 400mM concentration of liposomal solution by using a 300 MHz ESR spectrometer. The ESR parameters such as linewidth, hyperfine coupling constant, g-factor, partition parameter and permeability were reported for these samples. The line broadening was observed for the nitroxyl spin probe in the liposomal solution. The line broadening indicates that the high viscous nature of the liposomal solution. The partition parameter and permeability values indicate the maximum diffusion of nitroxyl spin probes in the bilayer lipid membranes at 2 mM concentration of nitroxyl radical. This study illustrates that ESR can be used to differentiate between the intra and extra- membrane water by loading the liposome vesicles with a lipid-permeable nitroxyl spin probe. From the ESR results, the spin probe concentration was optimized as 2mM in liposomal solution for ESR phantom studies/imaging, invivo and invitro experiments.

  20. Dosimetry of blood irradiation using an alanine/ESR dosimeter

    A batch of 80 DL-alanine dosimeters was supplied to Hemocentro of the Hospital and Clinics of Faculdade de Medicina de Ribeirao Preto (HC-FMRP) SP, Brazil for the purpose of quality control of the radiation dose delivered to blood bags. The irradiation was made using two (40x40) cm2 parallel opposed radiation fields each with 80 cm of source to surface distance in the Radiotherapy Section of HC-FMRP with the 60Co teletherapy unit. The calculated radiation absorbed dose at the center of the box was 20 Gy. The dosimeter readings were performed using a Varian E-4 ESR Spectrometer operating in X-band. For the 80 dosimeters and over the irradiation volume throughout a blood bag, the minimum and maximum doses were 14 and 23 Gy, respectively. The mean dose was (18±2) Gy (1σ), and the coefficient of variability was 11.1%. Alanine dosimeters demonstrated easy handling, good precision and adequate sensitivity for this application

  1. ESR dosimetry of optically bleached quartz grains extracted from Plio-Quaternary sediment: Evaluating some key aspects of the ESR signals associated to the Ti-centers

    The present study aims at investigating several key aspects of ESR dose reconstruction of quartz grains based on the analysis of the Ti-center: (i) the evaluation of the ESR intensity, (ii) its impact on measurements precision, and (iii) the potential of various fitting functions to describe the behavior of the signal with the radiation absorbed dose. In contrast with the Al center, the various Ti centers have quite low ESR signal intensities. It is thus crucial to adapt the experimental conditions for the optimization of the signal-to-noise ratio and to perform repeated measurements in order to take into consideration the uncertainty associated to angular dependence of the signal as well as day-to-day variations. Several options (named A to E) for evaluating the ESR intensity of the Ti–Li and Ti–H centers are explored and some of them yield too much experimental uncertainty (e.g. options C and E) and are apparently not suitable for accurate ESR dosimetry. In contrast, options A and D usually provide similar equivalent dose (DE) results and can be used together for assessing the dose absorbed by the Ti–Li center. Our results show a systematic non-monotonic behavior of the ESR signal of the Ti center with the dose, which raise some questions about the suitability of the single saturating exponential (SSE) function that is classically used in ESR dating. Consequently, we explored the potential of other functions that can describe the “radiation bleaching” phenomenon observed at high doses. We recommend the use of a specific fitting function (called Ti-2 in the present paper) previously proposed by Woda and Wagner (2007) for any dose reconstruction, and define some criteria to ensure a good fitting. The SSE function provides DE results that are, in most cases, relatively consistent with those derived from the Ti-2, suggesting that the Ti centers apparently follow a SSE behavior up to, at least, 6.0–6.5 kGy However, the reliability of the DE values

  2. Acoustic hemostasis

    Crum, L.; Andrew, M.; Bailey, M.; Beach, K.; Brayman, A.; Curra, F.; Kaczkowski, P.; Kargl, S.; Martin, R.; Vaezy, S.

    2003-04-01

    Over the past several years, the Center for Industrial and Medical Ultrasound (CIMU) at the Applied Physics Laboratory in the University of Washington has undertaken a broad research program in the general area of High Intensity Focused Ultrasound (HIFU). Our principal emphasis has been on the use of HIFU to induce hemostasis; in particular, CIMU has sought to develop a small, lightweight, portable device that would use ultrasound for both imaging and therapy. Such a technology is needed because nearly 50% of combat casualty mortality results from exsanguinations, or uncontrolled bleeding. A similar percentage occurs for civilian death due to trauma. In this general review, a presentation of the general problem will be given, as well as our recent approaches to the development of an image-guided, transcutaneous, acoustic hemostasis device. [Work supported in part by the USAMRMC, ONR and the NIH.

  3. Acoustic telemetry.

    Drumheller, Douglas Schaeffer; Kuszmaul, Scott S.

    2003-08-01

    Broadcasting messages through the earth is a daunting task. Indeed, broadcasting a normal telephone conversion through the earth by wireless means is impossible with todays technology. Most of us don't care, but some do. Industries that drill into the earth need wireless communication to broadcast navigation parameters. This allows them to steer their drill bits. They also need information about the natural formation that they are drilling. Measurements of parameters such as pressure, temperature, and gamma radiation levels can tell them if they have found a valuable resource such as a geothermal reservoir or a stratum bearing natural gas. Wireless communication methods are available to the drilling industry. Information is broadcast via either pressure waves in the drilling fluid or electromagnetic waves in the earth and well tubing. Data transmission can only travel one way at rates around a few baud. Given that normal Internet telephone modems operate near 20,000 baud, these data rates are truly very slow. Moreover, communication is often interrupted or permanently blocked by drilling conditions or natural formation properties. Here we describe a tool that communicates with stress waves traveling through the steel drill pipe and production tubing in the well. It's based on an old idea called Acoustic Telemetry. But what we present here is more than an idea. This tool exists, it's drilled several wells, and it works. Currently, it's the first and only acoustic telemetry tool that can withstand the drilling environment. It broadcasts one way over a limited range at much faster rates than existing methods, but we also know how build a system that can communicate both up and down wells of indefinite length.

  4. Acoustic Neuroma Educational Video

    Full Text Available Educational Video Home What is an AN What is an Acoustic Neuroma? Identifying an AN Symptoms Acoustic Neuroma Keywords Educational Video ... for pre- and post-treatment acoustic neuroma patients. Home What is an AN What is an Acoustic ...

  5. Use of acoustic vortices in acoustic levitation

    Cutanda Henriquez, Vicente; Santillan, Arturo Orozco; Juhl, Peter Møller

    2009-01-01

    Acoustic fields are known to exert forces on the surfaces of objects. These forces are noticeable if the sound pressure is sufficiently high. Two phenomena where acoustic forces are relevant are: i) acoustic levitation, where strong standing waves can hold small objects at certain positions...... of acoustical vortices uses an efficient numerical implementation based on the superposition of two orthogonal sound fields with a delay of 90° between them. It is shown that acoustic levitation and the use of acoustic vortices can be combined to manipulate objects in an efficient and controlled manner without......, counterbalancing their weight, and ii) acoustic vortices, spinning sound fields that can impinge angular momentum and cause rotation of objects. In this contribution, both force-creating sound fields are studied by means of numerical simulations. The Boundary Element Method is employed to this end. The simulation...

  6. Acoustic dispersive prism

    Hussein Esfahlani; Sami Karkar; Herve Lissek; Mosig, Juan R.

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic ...

  7. Differences in the radiation sensitivity of human tooth enamel in an individual and among the individuals in dental ESR dosimetry

    To study the individual difference of radiation sensitivity of tooth enamel in dental ESR dosimetry, 144 enamel samples were separated from 5 subjects, irradiated with 60Co gamma-rays up to 1290x10-4 C/kg (500 R), and measured with the ESR system. The coefficient of variation of ESR signals obtained for all enamel samples except two samples from one tooth was 7.8%. (author)

  8. Thermoluminescence and ESR studies and dating of naturalcalcite minerals

    correlation within the limits of confidence. Furthermore, it was also found that these values were not effected from different dose rates. Annual dose of the samples were calculated by combining the results of two methods which give internal and external doses received. To determine internal dose rate, the amount of radioactive elements 238U, 232Th and 40K in the samples were measured. Neutron activation analysis was performed for this measurement. For external dose rate measurement CaSO4, Dy dosimeters were used. The ages of each travertine sample were thus calculated by using annual dose, ED and JD values. The age of Denizli travertine is determined to be 774.000 t 66.000 years and that of Cankiri travertine is 103.000 t 9.000 years. The ESR spectra of the same samples were also taken at room temperature. The ESR signals in the spectra were assigned to C03 3 . C03 and COZ centres that were originated from the ionization of C03 z groups, which is the major constituent of calcite after irradiation. The heating of irradiation samples at different temperatures above room temperature for equal periods showed that 180 deg. C, 280 deg. C peaks in Denizli travertines, and 170 deg. C, 270 deg. C glow peaks in Cankiri travertines, are correlated with C03 3 and COz centres and the peaks at 330 oC are correlated with C03 centres. The ages of the same samples were also calculated by ESR method and the ages of Denizli and Cankiri travertines are found to be 1.110.000 t 110.000, 230.000 t 22.000 years respectively. The differences in ages determined by these two methods are explained by the nature of thermoluminescence method. The decreacing ot the luminescence emission sensitivity of the trapped electrons with respect to different parameters is assumed to be the main reason for the low value obtained by the thermoluminescence

  9. Evolution of the Kondo state of YbRh2Si2 probed by high field ESR

    Schaufuß, U.; KATAEV V.; Zvyagin, A. A.; Büchner, B.; Sichelschmidt, J.; Wykhoff, J.; Krellner, C.; Geibel, C.; Steglich, F.

    2008-01-01

    An electron spin resonance (ESR) study of the heavy fermion compound YbRh2Si2 for fields up to ~ 8 T reveals a strongly anisotropic signal below the single ion Kondo temperature T_K ~ 25 K. A remarkable similarity between the T-dependence of the ESR parameters and that of the specific heat and the 29Si nuclear magnetic resonance data gives evidence that the ESR response is given by heavy fermions which are formed below T_K and that ESR properties are determined by their field dependent mass a...

  10. Comprehensive genetic assessment of the ESR1 locus identifies a risk region for endometrial cancer.

    O'Mara, Tracy A; Glubb, Dylan M; Painter, Jodie N; Cheng, Timothy; Dennis, Joe; Attia, John; Holliday, Elizabeth G; McEvoy, Mark; Scott, Rodney J; Ashton, Katie; Proietto, Tony; Otton, Geoffrey; Shah, Mitul; Ahmed, Shahana; Healey, Catherine S; Gorman, Maggie; Martin, Lynn; Hodgson, Shirley; Fasching, Peter A; Hein, Alexander; Beckmann, Matthias W; Ekici, Arif B; Hall, Per; Czene, Kamila; Darabi, Hatef; Li, Jingmei; Dürst, Matthias; Runnebaum, Ingo; Hillemanns, Peter; Dörk, Thilo; Lambrechts, Diether; Depreeuw, Jeroen; Annibali, Daniela; Amant, Frederic; Zhao, Hui; Goode, Ellen L; Dowdy, Sean C; Fridley, Brooke L; Winham, Stacey J; Salvesen, Helga B; Njølstad, Tormund S; Trovik, Jone; Werner, Henrica M J; Tham, Emma; Liu, Tao; Mints, Miriam; Bolla, Manjeet K; Michailidou, Kyriaki; Tyrer, Jonathan P; Wang, Qin; Hopper, John L; Peto, Julian; Swerdlow, Anthony J; Burwinkel, Barbara; Brenner, Hermann; Meindl, Alfons; Brauch, Hiltrud; Lindblom, Annika; Chang-Claude, Jenny; Couch, Fergus J; Giles, Graham G; Kristensen, Vessela N; Cox, Angela; Pharoah, Paul D P; Dunning, Alison M; Tomlinson, Ian; Easton, Douglas F; Thompson, Deborah J; Spurdle, Amanda B

    2015-10-01

    Excessive exposure to estrogen is a well-established risk factor for endometrial cancer (EC), particularly for cancers of endometrioid histology. The physiological function of estrogen is primarily mediated by estrogen receptor alpha, encoded by ESR1. Consequently, several studies have investigated whether variation at the ESR1 locus is associated with risk of EC, with conflicting results. We performed comprehensive fine-mapping analyses of 3633 genotyped and imputed single nucleotide polymorphisms (SNPs) in 6607 EC cases and 37 925 controls. There was evidence of an EC risk signal located at a potential alternative promoter of the ESR1 gene (lead SNP rs79575945, P=1.86×10(-5)), which was stronger for cancers of endometrioid subtype (P=3.76×10(-6)). Bioinformatic analysis suggests that this risk signal is in a functionally important region targeting ESR1, and eQTL analysis found that rs79575945 was associated with expression of SYNE1, a neighbouring gene. In summary, we have identified a single EC risk signal located at ESR1, at study-wide significance. Given SNPs located at this locus have been associated with risk for breast cancer, also a hormonally driven cancer, this study adds weight to the rationale for performing informed candidate fine-scale genetic studies across cancer types. PMID:26330482

  11. ESR investigation of L-α-alanine and sucrose radicals produced by heavy-ion irradiation

    We investigated sucrose and L-α-alanine radicals produced by heavy (particle) ion irradiation with various LETs (linear energy transfer). The impact of the heavy ions on the samples produced stable free radicals, which were analyzed by ESR (electron spin resonance). Identical spectra were measured after one year. The obtained spectral patterns were the same as those for helium (He), carbon (C), and neon (Ne) ions irradiation. The absorbed dose dependences for the irradiated sucrose and alanine samples were examined. The ESR response has a linear relation with the absorbed dose. The ESR response at 60 Gy was slightly lower than a linear line for sucrose; however, the response showed good linearity for the alanine. In addition, the total spin concentration obtained by heavy-ion irradiation correlated logarithmically with the LET. Qualitative ESR analyse showed that the production of sucrose and alanine radicals depended on both different particle irradiation and the LET under the same dose. Thus, the present ESR results imply that sucrose together with L-α-alanine can be used to monitor LET as well as the number of ionizing particle for the production of stable free radicals. (author)

  12. Oxidative stress-mediated protein conformation changes: ESR study of spin-labelled staphylococcal nuclease

    We report on the electron spin resonance (ESR) study of the photo-oxidative stress-mediated protein conformation changes in the spin-labelled protein staphylococcal nuclease (SNase). The photo-oxidative stress was brought on by photosensitization of singlet oxygen (1Δg) in the presence of a novel photosensitizer, water-soluble fullerol C60(OH)19(ONa)17, and resulted in partial protein denaturation. This process was monitored via ESR measurements performed for a spin-labelled SNase Thr-62-Cys mutant, with MTSSL spin label (SL) attached to the cysteine 62 residue (SNase T62C-SL). Prior to ESR measurements of the oxidative stress-induced alterations in protein conformations, the efficiency of C60(OH)19(ONa)17 for 1Δg-generation was confirmed by three different techniques: (i) selective reactive scavenging of 1Δg and ESR detection of the resulting paramagnetic product (ii) 1Δg-mediated photo-oxidative loss of tryptophan and (iii) by measuring the characteristic near-infrared phosphorescence of singlet oxygen at 1270 nm. The observed evolution of the ESR spectra of SNase T62C-SL as a function of exposure to the photo-oxidative stress points to marked changes in protein conformation due to the deleterious action of 1Δg

  13. Dating of aragonite and dolomite from Devil's cave - SP, by dosimetric thermoluminescent method (DTL) and ESR

    We have investigated TL (Thermoluminescence) and ESR (electron spin resonance) properties of aragonite and dolomite found at ''Caverna do Diabo (Devil's cave)'' in the state of Sao Paulo to determine the ages of these geological materials. The aragonite, which is not a thermoluminescent material, shows one ESR signal whit g = 2.003. We obtained the age of 1.1 x 105 years and the growth rate of 1 μ m/year by the sample calibration with additional Y irradiation. The dolomite gives a TL glow curve with three distinct peaks at 261, 334 and 395 0C. We found that the fit for the TL glow curve to second-order kinetics can be considerered as very acceptable. Using the second TL peak we obtained the age of 9.4 x 10 5 years and the compatible values of the activation energy (1.90 ± 0,07 eV) by the following methods: Hyperbolic heating, isothermal decay and fractional glow technique. We observed many ESR absorption signals in the dolomite. Three principal signal com g = 2.002, 2.003 and 2.005 were studied. We found that the first and second ESR signals were atributed to the CO2- and/or CO33- centers and the last to the CO3- centers, and observed that the first ESR signal might related with the second TL peak and the TL sensitivity were associated with the concentration of Mn2+

  14. Acoustic Neurinomas

    Mohammad Faraji Rad

    2011-01-01

    Full Text Available Acoustic neuromas (AN are schwann cell-derived tumors that commonly arise from the vestibular portion of the eighth cranial nerve also known as vestibular schwannoma(VS causes unilateral hearing loss, tinnitus, vertigo and unsteadiness. In many cases, the tumor size may remain unchanged for many years following diagnosis, which is typically made by MRI. In the majority of cases the tumor is small, leaving the clinician and patient with the options of either serial scanning or active treatment by gamma knife radiosurgery (GKR or microneurosurgery. Despite the vast number of published treatment reports, comparative studies are few. The predominant clinical endpoints of AN treatment include tumor control, facial nerve function and hearing preservation. Less focus has been put on symptom relief and health-related quality of life (QOL. It is uncertain if treating a small tumor leaves the patient with a better chance of obtaining relief from future hearing loss, vertigo or tinnitus than by observing it without treatment.   In this paper we review the literature for the natural course, the treatment alternatives and the results of AN. Finally, we present our experience with a management strategy applied for more than 30 years.

  15. Acoustic Spatiality

    Brandon LaBelle

    2012-06-01

    Full Text Available Experiences of listening can be appreciated as intensely relational, bringing us into contact with surrounding events, bodies and things. Given that sound propagates and expands outwardly, as a set of oscillations from a particular source, listening carries with it a sensual intensity, whereby auditory phenomena deliver intrusive and disruptive as well as soothing and assuring experiences. The physicality characteristic of sound suggests a deeply impressionistic, locational "knowledge structure" – that is, the ways in which listening affords processes of exchange, of being in the world, and from which we extend ourselves. Sound, as physical energy reflecting and absorbing into the materiality around us, and even one's self, provides a rich platform for understanding place and emplacement. Sound is always already a trace of location.Such features of auditory experience give suggestion for what I may call an acoustical paradigm – how sound sets in motion not only the material world but also the flows of the imagination, lending to forces of signification and social structure, and figuring us in relation to each other. The relationality of sound brings us into a steady web of interferences, each of which announces the promise or problematic of being somewhere.

  16. Springer Handbook of Acoustics

    Rossing, Thomas D

    2007-01-01

    Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience, and others. The Springer Handbook of Acoustics is an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents spanning: animal acoustics including infrasound and ultrasound, environmental noise control, music and human speech and singing, physiological and psychological acoustics, architectural acoustics, physical and engineering acoustics, signal processing, medical acoustics, and ocean acoustics. This handbook reviews the most important areas of acoustics, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest rese...

  17. Responsive acoustic surfaces

    Peters, Brady; Tamke, Martin; Nielsen, Stig Anton;

    2011-01-01

    Acoustic performance is defined by the parameter of reverberation time; however, this does not capture the acoustic experience in some types of open plan spaces. As many working and learning activities now take place in open plan spaces, it is important to be able to understand and design for the...... acoustic conditions of these spaces. This paper describes an experimental research project that studied the design processes necessary to design for sound. A responsive acoustic surface was designed, fabricated and tested. This acoustic surface was designed to create specific sonic effects. The design was...... simulated using custom integrated acoustic software and also using Odeon acoustic analysis software. The research demonstrates a method for designing space- and sound-defining surfaces, defines the concept of acoustic subspace, and suggests some new parameters for defining acoustic subspaces....

  18. Ion-acoustic solitary waves and spectrally uniform scattering cross section enhancements

    J. Ekeberg

    2010-06-01

    Full Text Available Spectra measured by incoherent scatter radars are formed predominantly by scattering of the incident signal off ion-acoustic and Langmuir waves in the ionosphere. Occasionally, the upshifted and/or downshifted lines produced by the ion-acoustic waves are enhanced well above thermal levels and referred to as naturally enhanced ion-acoustic lines. In this paper, we study another kind of enhancement, which is spectrally uniform over the whole ion-line, i.e. the up- and downshifted shoulder and the spectral valley in between. Based on observations made with the EISCAT Svalbard radar (ESR facility, we investigate the transient and spectrally uniform power enhancements, which can be explained by ion-acoustic solitary waves. We use a theory of nonlinear waves in a magnetized plasma to determine the properties of such waves and evaluate their effects on scattered signals measured by ESR. We suggest a new mechanism that can explain backscattered power enhancements by one order of magnitude above the thermal level and show that it is consistent with observations.

  19. Acoustic source for generating an acoustic beam

    Vu, Cung Khac; Sinha, Dipen N.; Pantea, Cristian

    2016-05-31

    An acoustic source for generating an acoustic beam includes a housing; a plurality of spaced apart piezo-electric layers disposed within the housing; and a non-linear medium filling between the plurality of layers. Each of the plurality of piezoelectric layers is configured to generate an acoustic wave. The non-linear medium and the plurality of piezo-electric material layers have a matching impedance so as to enhance a transmission of the acoustic wave generated by each of plurality of layers through the remaining plurality of layers.

  20. ESR Dosimetry Below 1 Gy, in X-Ray Irradiated Tooth Enamel

    Tooth enamel, extracted from molars, was irradiated with 66keV X-rays, with doses up to 1Gy.The preparation of the powder samples is described, as well as the protocol for the acquisition and processing of the spectra.The radiation induced paramagnetism is measured, at room temperature, by ESR Spectroscopy.The ESR spectra is well described considering two paramagnetic species, with magnetic moments (in units of Bohr magnetons) g=2,0041, and g1=2,0018, g2=1,9972.The ESR data (peak-to-peak amplitude per mg, hpp/mg, vs dose D), for doses 0Gy2 =0,996) with the linear expression: [hpp/mg] = -0,2( 0,4)+14,9(0,5). D [Gy].The result supports the growing confidence in the use of this material, and method, in Retrospective Dosimetry

  1. Influence of Electrolyte on ESR of Medium Voltage Wet Tantalum Capacitors

    刘仲娥; 宋金荣; 陈晓静; 李忆莲; 桂娟

    2004-01-01

    In this paper, the influence of working electrolyte on high-frequency electrical performance of wet tantalum capacitors is studied. Emphasis is especially put on the study of the contribution of depolariser in reducing Equivalent Series Resistance(ESR). According to the theory of depolarization in electrochemistry and the theory of cathode capacitance of electrolytic capacitor, different kinds of depolarisers are added separately into the foregone electrolyte. Then capacitors are assembled with tantalum cores dipped with the compounded electrolytes. The best depolariser and its concentration in the whole electrolyte could be selected according to the test results of the capacitance and ESR of the capacitors. The results of our experiment show that depolariser Fe2(SO4)3 used in working electrolyte of 100 V/100 μF wet tantalum capacitors can help to obtain lower ESR and higher capacitance at frequency from 0.1 kHz to 100 kHz.

  2. ESR dosimetry below 1 Gy, in X-ray irradiated tooth enamel

    Tooth enamel, extracted from molars, was irradiated with 66 keV X-rays, with doses up to 1 Gy. The preparation of the powder samples is described, as well as the protocol for the acquisition and processing of the spectra. The radiation induced paramagnetism is measured, at room temperature, by ESR Spectroscopy. The ESR spectra is well described considering two paramagnetic species, with magnetic moments (in units of Bohr magneton) g=2,0041, and g1=2,0018, g2=1,9972. The ESR data (peak-to-peak amplitude per mg, hpp/mg, vs dose D), for doses 0 Gy2 =0,996) with the linear expression: [hpp/mg] = -0,2(0,4)+14,9(0,5). D [Gy]. The result supports the growing confidence in the use of this material, and method, in Retrospective Dosimetry. (author)

  3. ESR of copper and iron complexes with antitumor and cytotoxic properties

    Antholine, W.E.; Kalyanaraman, B.; Petering, D.H.

    1985-12-01

    The relatively few iron and copper metal complexes which have been examined in cells and tissues for their redox properties, radical generation properties, and antitumor activity are discussed for studies which utilized electron spin resonance spectroscopy (ESR). A common property of a number of metal complexes, which include bleomycin, adriamycin, and thiosemicarbazones described in this review, is that they are readily reduced by thiol compounds and oxidized by oxygen or reduced species of oxygen to produce radicals. Structural features of these reactions are identified by ESR spectroscopy in model systems and often in cells. Furthermore, ESR spectroscopy has been most useful to probe the environment of the complexes in cells and to measure the rate of reduction of their oxidized forms. As a result of these studies, it is anticipated that more attention will be given to the exploration of redox-active metal complexes as drugs. 95 references.

  4. Construction of an ESR-STM for Single Molecular Based Magnets anchored at Surfaces

    Messina, Paul C; Lenci, L; Prato, S; Pittana, P; Gatteschi, Dante; Messina, Paolo; Sigalotti, Paolo; Lenci, Lorenzo; Prato, Stefano; Pittana, Paolo; Gatteschi, Dante

    2004-01-01

    Reading and manipulating the spin status of single magnetic molecules is of paramount importance both for applicative and fundamental purposes. The possibility to combine Electron Spin Resonance (ESR) and Scanning Tunnelling Microscopy (STM) has been explored one decade ago. A few experiments have raised the question whether or not an EPR spectrum of single molecule is detachable. Only a few data have been reported in modern surface science literature. To date it has yet to be proven till which extent ESR can be reliably and reproducibly performed on single molecules. We are setting up a new ESR-STM (spectrometer) to verify and study the effect of spin-spin correlations in the frequency spectrum of the tunneling current which flows through a single magnetic adsorbate and a metal surface. Here we discuss, the major experimental challenges that we are attempting to overcome.

  5. Direct ionization effects of purine derivatives: ESR and ENDOR studies of 5'GMP

    In this study the free acid of 5' GMP was investigated (in the form of 5'GMP.3H/sub 2/O crystals). Irradiation and study of the molecular system below 10K gave evidence for at least three products in the ESR. Product I was also studied by ENDOR, and has been tentatively identified as the result of the anion protonated at 06. From the experimental data the spin distribution in product I is: 30% at C8; 12% at N1; 10% at N7. Product II was identified from its characteristic ESR as the result of hydrogen addition at C8. Product III was evident in the ESR but has not yet been identified

  6. Researches and Applications of ESR Dosimetry for Radiation Accident Dose Assessment

    The aim of this work was to establish methods suitable for practical dose assessment of people involved in ionising radiation accidents. Some biological materials of the human body and materials possibly carried or worn by people were taken as detection samples. By using electron spin resonance (ESR) techniques, the basic dosimetric properties of selected materials were investigated in the range above the threshold dose of human acute haemopoietic radiation syndrome. The dosimetric properties involved included dose response properties of ESR signals, signal stabilities, distribution of background signals, the lowest detectable dose value, radiation conditions, environmental effects on the detecting process, etc. Several practical dose analytical indexes and detecting methods were set up. Some of them (bone, watch glass and tooth enamel) had also been successfully used in the dose assessment of people involved in three radiation accidents, including the Chernobyl reactor accident. This work further proves the important role of ESR techniques in radiation accident dose estimation. (author)

  7. ESR dating of barite in sulphide deposits formed by the sea-floor hydrothermal activities

    Barite is a mineral newly found to be practically useful for electron spin resonance (ESR) dating of sulphide deposits formed by the sea-floor hydrothermal activities. The recent studies for the properties of the ESR dating signal in barite are summarised in the present paper as well as the formulas for corrections for accurate dose-rate estimation are developed including the dose-rate conversion factors, shape correction for gamma-ray dose and decay of 226Ra. Although development of the techniques for ESR dating of barite has been completed, further comparative studies with other dating techniques such as U-Th and 226Ra-210Pb dating are necessary for the technique to be widely used. (authors)

  8. ESR Spectrometer as a Possible Tool for Rapid Analysis of Cane Sugar Purity

    Kheamrutai Thamaphat; Pichet Limsuwan; Siwaporn Meejoo

    2007-01-01

    A method for quantitative/qualitative determination of eane sugar purity by ESR is devised.Relined sugar,plantation white sugar.soft brown sugar and raw sugar are used as samples in this work.The sucrose radical is produced by pulverization of sugar and it increases as the particle size decreases.Based on pulverization-induced sucrose radical.EsR study demonstrates the effects of sugar purity on characteristic of ESR spectrum.The relationshjp between the sucrose contents and peak area under the ESR spectrum is manifested.It is found that the peak area or sucrose radical concentration increases linearly With the increase of sucrose content.Using the linear regression method.the Sucrose amount can be revealed.This approach is a promising fast and accurate method for sugar purity analysis.

  9. Molecular Characterization and Sex-Specific Tissue Expression of Estrogen Receptor Alpha (esr1), Estrogen Receptor Beta-a (esr2a) and Ovarian Aromatase (cyp19a1a) in Yellow Perch (Perca flavescens)

    Yellow perch (Perca flavescens) exhibit an estrogen-stimulated sexual size dimorphism (SSD) wherein females grow faster and larger than males. To aid in the examination of this phenomenon, the cDNA sequences encoding estrogen receptor-alpha (esr1), estrogen receptor-beta-a (esr2a) and ovarian aroma...

  10. ESR study on ZnAl2S4 crystal compound doped by Cr''+''3

    The spinel ZnAl2S4 single crystal doped by paramagnetic Cr''+''3 and Mn''+''2 has been studied by Electron Spin Resonance (ESR) technique in the temperature range of 10-300 K. The crystal field symmetry around the impurity ions has been determined from the angular behavior of X-band ESR spectra. A well resolved multiplet composed of very narrow thirty one peaks was shown to originate from the interaction between unpaired electron spins of Cr''+''3 ion and nuclear spin of six neighboring Al''2''7 (I=5/2) at octahedral sites due to weak covalent bounding with Al atom located at the center of the octahedra. These hyperfine peaks show anisotropic behavior. A relatively weaker six tet in the ESR spectra was also observed to originate from Mn''5''5 (I=5/2) ion located at tetrahedral sites. Computer analysis of the ESR data indicated a high homogeneity and quality for the crystal. The crystal is proven to be in the normal spinel structure for ZnAl2S4, and there is no distortion from the spinel nature, contrary to the speculation in the literature about the similar compound. There is no deviation from cubic symmetry measurable even by a very high sensitive technique like ESR. The magnetic electrons of Cr''+''3 ion are highly localized on Cr''+''3 , while the unpaired electrons of Mn''+''2 are significantly delocalized to get covalent bounding with neighboring atoms (S, Al). The temperature does not affect these localization properties of the electrons either. The very narrow and well-determined energy levels manifest themselves in very narrow peaks with g=2 of Cr''+''3, making this crystal a very good candidate for laser applications. Negligible temperature dependence of ESR spectra for both Mn''+''2 and Cr''+''3 ions indicates strong stability of the crystal symmetry of both tetrahedral and octahedral sites against the temperature

  11. ESR investigation of structure and dynamics of paramagnetic centres in lime mortars from Budinjak, Croatia

    This study presents the preliminary results of investigation of the types and dynamics of paramagnetic centres in lime mortars from Sveta Petka church in Budinjak, Croatia, using Electron Spin Resonance (ESR) spectroscopy. The excavation in Budinjak discovered a very unique four lobed plan object Sveta Petka, with no additional finds or reliable historical records about the time of its construction. The lime mortars from the church were chosen for analysis in order to characterize the building material and to verify the site chronology by dating them. Lime mortar is valuable but problematic material for luminescence and radiocarbon dating. This type of material has not been dated before using ESR; therefore, careful studies are required to identify the useful paramagnetic centres. The ESR approach suggested in this work concentrates on a calcium carbonate signal. All samples were γ-irradiated in 60C bomb with the doses of 1, 10, 20, 50, 80 and 100 kGy. In all spectra signals from Fe3+ and Mn2+ ions have been observed. Paramagnetic centres which give the ESR signals may be interpreted as CO2−, CO3−, CO33−, HCO32−, SO2−, SO3−, PO2− and PO32− species. However, all spectra are complex and signals are interfering; therefore, computer resolution enhancement method will be needed in further research. The changes in ESR signals amplitude measured at magnetic field range about 3440–3450 G were analysed versus the dose of irradiation, using Mn2+ signals as a reference. Exponential growth of the curve and saturation for doses above 20 kGy were observed; therefore, irradiation with smaller doses is required. These preliminary studies will be helpful in future attempts of dating lime mortars by ESR method.

  12. Iron supplementation generates hydroxyl radical in vivo. An ESR spin-trapping investigation.

    Kadiiska, M B; Burkitt, M J; Xiang, Q H; Mason, R P

    1995-01-01

    Electron spin resonance (ESR) spectroscopy has been used to investigate hydroxyl radical generation in rats with chronic dietary iron loading. A secondary radical spin-trapping technique was used where hydroxyl radical forms methyl radical upon reaction with DMSO. The methyl radical was then detected by ESR spectroscopy as its adduct with the spin trap alpha-phenyl-N-t-butylnitrone (PBN). This adduct was detected in the bile of rats 10 wk after being fed an iron-loading diet and 40 min after ...

  13. ESR spectra and electronic structure of the MoO3+ complex with the dithiocarbamate ligand

    ESR spectra of liquid and frozen benzene solutions of isotope-enriched 95,97,98Mo5+ O(DEDTC)3 complexes ([xMo] > 95%, DEDTC is N,N-diethyldithiocarbamate ligand) and their solid solutions in the tetraethylthiuram disulfide matrix were studied in the X-range. Comparison of the experimental and calculated parameters of the ESR spectra shows that axial symmetry of the magnetic tensors does not contract low symmetry of the complex, in which the ylic oxygen and five of six S atoms of three dithiocarbamate ligands form the coordination sphere of the metal

  14. ESR analysis of point defects produced in quartz by fast and thermal neutron irradiation

    ESR signals derived from intrinsic lattice defects in quartz, oxygen vacancies and interstitials, were detected by gamma or neutron irradiation. In addition, an unknown ESR signal at g=2.0050 also was detected by neutron irradiation. This unknown signal may be a superoxide (O2-) produced in depleted zones in quartz, which are formed by knock-on with fast neutrons. Microwave power characteristics indicates that this unknown signal is quite different from a peroxy center (Si-O-O·) although both signals can be produced by knock-on. (author)

  15. Investigation of detergent powder as gamma radiation dosimeter using ESR technique

    Detergent powder is one of the most commonly available laboratory materials, which is often used for decontamination. If radiation exposure induced free radicals in this matrix are measurable, it can potentially serve as a retrospective dosimeter under accidental conditions. Therefore work in the study of radiation induced radicals in the detergent powder by electron spin resonance (ESR), were initiated and evaluated for its potential as a ESR dosimeter at higher dose ranges. These results therefore suggest that detergent can be used as a possible dosimeter in programmes such as food preservation by irradiation (1 kGy - 10 kGy) and accidental dosimetry at lower dose levels (∼25 Gy)

  16. ESR/ENDOR study of the guanine cation: Secondary product in 5' -dGMP

    Previous ESR studies by Voit and Huttermann of x-irradiated single crystals of 2' deoxyguanosine-5'-monophosphate have indicated the presence of a radical thought to be formed by deprotonation of the primary base cation at N1. In this study the authors report results of a detailed ESR and ENDOR experiment at 10 K which conflict with the results cited above. One of the radicals detected inhibited two α-proton type couplings. The data analysis shows that one coupling is due to the proton on the extra annular NH/sub 2/ group, while the other is due to the proton bonded to C8

  17. X-band ESR study on evaluation of radicals induced in pasteurized pepper

    The radical properties of pasteurized pepper were investigated by means of X-band ESR spectroscopy. Pasteurization process was done by irradiation or steam. There were three radicals in the specimens before and after pasteurization. Upon irradiation a new radical was found. ESR peak intensity of specimen before and after parturition with steam was almost same level. Peak intensity of radiated pepper showed almost 4 times as compare with that of non treated pepper. Radical activity of the specimens after pasteurization showed almost same value. We concluded that radicals were induced by irradiation. But the radical activity was not changed before and after pasteurization. (author)

  18. Effects of alpha radiation on plutonium incorporated in dosimetric materials by ESR studies

    The in situ alpha irradiation effects of some ESR dosimetric materials namely alanine, 2-methyl alanine and ammonium tartrate were studied by incorporating 1% plutonium by weight in them. The radical intensity was monitored as a function of alpha dose. It was found that in the dose region 1-35 kGy ammonium tartrate showed better signal intensity, linearity and dose response as compared to the other materials. This was attributed to the single radical produced in case of the tartrate giving a sharp spectrum and the fast relaxation times owing to less saturation of ESR signals. (author)

  19. Applications of some polycrystalline hydrocarbons (alanine and sugars) for high-dose measurement by ESR spectrometry

    The comparative results of investigations of some polycrystalline hydrocarbons as dosimeters by ESR spectrometry in the absorbed dose range of 0.05-50 kGy are presented. Gamma- and beta-radiation sources and primary standards used for accurate measurement of absorbed dose in standard substances are also described. Also included are the analysis and quantitative assessment of the components of uncertainty of absorbed dose evaluations as measured by certain solid-state hydrocarbon (sugar) detectors, e.g. D-glucose. This substance, in addition to DL-alanine, are recommended for ESR-dosimetry. (Author)

  20. Dynamic nuclear polarization-magnetic resonance imaging at low ESR irradiation frequency for ascorbyl free radicals

    Shinji Ito; Fuminori Hyodo

    2016-01-01

    Highly water-soluble ubiquinone-0 (CoQ0) reacts with ascorbate monoanion (Asc) to mediate the production of ascorbyl free radicals (AFR). Using aqueous reaction mixture of CoQ0 and Asc, we obtained positively enhanced dynamic nuclear polarization (DNP)-magnetic resonance (MR) images of the AFR at low frequency (ranging from 515 to 530 MHz) of electron spin resonance (ESR) irradiation. The shape of the determined DNP spectrum was similar to ESR absorption spectra with doublet spectral peaks. T...

  1. ESR studies of the magnetism in Ru-1212 and Ru-2212

    We have studied by electron spin resonance (ESR) the nonsuperconducting system Ru-1212 and the superconducting and nonsuperconducting Ru-2212 over the temperature range 100-300 K, in the normal and magnetic phases. In the nonsuperconducting Ru-1212 we found that the ferromagnetic line appears at a much higher temperature than the magnetic ordering as determined by neutron diffraction. We also show a correlation between the temperature dependence of the intensity and width of the ESR resonance lines, the intensity of magnetic absorption lines and the DC magnetization measurements. (orig.)

  2. Atlantic Herring Acoustic Surveys

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Advanced Sampling Technologies Research Group conducts annual fisheries acoustic surveys using state-of-the-art acoustic, midwater trawling, and...

  3. Acoustic Neuroma Educational Video

    Full Text Available ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ...

  4. Acoustic Neuroma Educational Video

    Full Text Available ... is ANA? Mission Statement Board of Directors ANA Staff Medical Advisory Board News ANA Annual Reports Acoustic ... is ANA? Mission Statement Board of Directors ANA Staff Medical Advisory Board News ANA Annual Reports Acoustic ...

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    Full Text Available ... ANA Annual Reports Acoustic Neuroma Legacy Society Programs & Services Join/Renew Ways to Give ANA Discussion Forum ... ANA Annual Reports Acoustic Neuroma Legacy Society Programs & Services Search ANAUSA.org Connect with us! Educational Video ...

  6. Acoustic Neuroma Educational Video

    Full Text Available ... Resources Patient Surveys Related Links Clinical Trials.gov Health Care Insurance Toolkit Additional Resources ANA Public Webinars © 2016 Acoustic Neuroma Association Acoustic Neuroma Association ® • ...

  7. Acoustic Neuroma Educational Video

    Full Text Available ... Options Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask ... Options Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask ...

  8. Acoustic Neuroma Educational Video

    Full Text Available ... ANA Staff Medical Advisory Board News ANA Annual Reports Acoustic Neuroma Legacy Society Programs & Services Join/Renew ... ANA Staff Medical Advisory Board News ANA Annual Reports Acoustic Neuroma Legacy Society Programs & Services Search ANAUSA. ...

  9. Cystic acoustic neuromas

    Chitkara, Naveen; Chanda, Rakesh; Yadav, S. P. S.; N.K. Sharma

    2002-01-01

    Predominantly cystic acoustic neuromas are rare and they usually present with clinical and radiological features different from their more common solid counterparts. Two cases of cystic acoustic neuromas are reported here.

  10. ESRS guidelines for software safety reviews. Reference document for the organization and conduct of Engineering Safety Review Services (ESRS) on software important to safety in nuclear power plants

    The IAEA provides safety review services to assist Member States in the application of safety standards and, in particular, to evaluate and facilitate improvements in nuclear power plant safety performance. Complementary to the Operational Safety Review Team (OSART) and the International Regulatory Review Team (IRRT) services are the Engineering Safety Review Services (ESRS), which include reviews of siting, external events and structural safety, design safety, fire safety, ageing management and software safety. Software is of increasing importance to safety in nuclear power plants as the use of computer based equipment and systems, controlled by software, is increasing in new and older plants. Computer based devices are used in both safety related applications (such as process control and monitoring) and safety critical applications (such as reactor protection). Their dependability can only be ensured if a systematic, fully documented and reviewable engineering process is used. The ESRS on software safety are designed to assist a nuclear power plant or a regulatory body of a Member State in the review of documentation relating to the development, application and safety assessment of software embedded in computer based systems important to safety in nuclear power plants. The software safety reviews can be tailored to the specific needs of the requesting organization. Examples of such reviews are: project planning reviews, reviews of specific issues and reviews prior final acceptance. This report gives information on the possible scope of ESRS software safety reviews and guidance on the organization and conduct of the reviews. It is aimed at Member States considering these reviews and IAEA staff and external experts performing the reviews. The ESRS software safety reviews evaluate the degree to which software documents show that the development process and the final product conform to international standards, guidelines and current practices. Recommendations are

  11. Determination of isodose curves in Radiotherapy using an Alanine/ESR dosemeter; Determinacion de curvas de isodosis en Radioterapia usando un dosimetro de Alanina/ESR

    Chen, F.; Baffa, O.; Graeff, C.F.O. [Departamento de Fisica e Matematica. Universidade de Sao Paulo FFCLRP. 14040-901 Ribeirao Preto-SP (Brazil)

    1998-12-31

    It was studied the possible use of an Alanine/ESR dosemeter in the isodose curves mapping in normal treatments of Radiotherapy. It was manufactured a lot of 150 dosemeters with base in a mixture of D-L Alanine dust (80 %) and paraffin (20 %). Each dosemeter has 4.7 mm diameter and 12 mm length. A group of 100 dosemeters of the lot were arranged inside 50 holes of the slice 25 of the phantom Rando Man. The phantom irradiation was realized in two opposed projections (AP and PA) in Co-60 equipment. A group of 15 dosemeters was take of the same lot for obtaining the calibration curve in a 1-20 Gy range. After irradiation the signal of each dosemeter was measured in an ESR spectrometer operating in the X-band ({approx} 9.5 GHz) and the wideness of Alanine ESR spectra central line was correlated with the radiation dose. The wideness dose calibration curve resulted linear with a correlation coefficient 0.9996. The isodose curves obtained show a profile enough similar at comparing with the theoretical curves. (Author)

  12. Validity and predictive ability of the juvenile arthritis disease activity score based on CRP versus ESR in a Nordic population-based setting

    Nordal, E B; Zak, Marek Stanislaw; Aalto, K;

    2012-01-01

    To compare the juvenile arthritis disease activity score (JADAS) based on C reactive protein (CRP) (JADAS-CRP) with JADAS based on erythrocyte sedimentation rate (ESR) (JADAS-ESR) and to validate JADAS in a population-based setting.......To compare the juvenile arthritis disease activity score (JADAS) based on C reactive protein (CRP) (JADAS-CRP) with JADAS based on erythrocyte sedimentation rate (ESR) (JADAS-ESR) and to validate JADAS in a population-based setting....

  13. ESR and NMR spectra simulation applied to molecular dynamics in anisotropic medium

    We describe two conversational programs written in APL for the purpose of ESR and NMR spectra simulations as well as relaxation times and line width calculations. These programs are particularly convenient for the studies of the molecular order and dynamics in liquid crystals. Several examples of their applications are reported

  14. ESR study on hydrogen-atom abstraction in cryogenic organic solids

    The present paper summarizes our recent results on the hydrogen-atom abstraction from protiated alkane molecule by deuterium atoms in cryogenic deuterated organic solids, obtained by the X-band ESR and electron spin-echo measurements of the product alkyl radicals at cryogenic temperatures. (J.P.N.)

  15. Diagnostic value of combined determination of blood RF, AKA, CRP contents and ESR for rheumatoid arthritis

    Objective: To explore the clinical usefulness of combined determination of blood rheumatoid factor (RF), anti-keratin antibody (AKA), CRP contents and ESR for diagnosis of rheumatoid arthritis (RA). Methods: Serum contents of RF, CRP (with rates nephelometry) and serum contents of AKA (with indirect immuno-fluorescence method) as well as ESR were determined in 35 patients with RA, 30 patients with SLE and 30 controls. Results: The diagnostic sensitivity and specificity of RF for RA were 71.4% and 91.7% respectively, those of AKA were 34.3% and 96.7% respectively. With combined determination of RF and AKA, the sensitivity was 81.2% and the specificity was 99.7%. The acute phase reaction product CRP was very sensitive (91.4%) but non-specific (25%). The same was true for ESR (sensitivity 88.6%, specificity 83.3%). With combined determination of these four factors, the sensitivity and specificity were the highest (99.98% and 99.97% respectively). Conclusion: RF, AKA, CRP and ESR could be used as the diagnostic serum marker for rheumatoid arthritis and combined determination of these four would produce a near perfect result. (authors)

  16. ESR Spectra of Some Silicate Minerals: A Search For New Dosimetric Materials

    Two silicate minerals talc (Mg3Si4O10 (OH)2) and zircon (ZrSiO4) having different crystal lattice structures were subjected to ESR dosimetric studies. Zircon shows anisotropic ESR signals at gxx=2.0168, gyy=2.0076 and gzz=2.0033, which have been identified as a hole center associated with Y3+ substituted at Zr4+ sites. Other characteristic signals have been observed and identified. The ESR signal at g=2.0033 showed positive response to γ-irradiation at 110 Gy and is suitable to be used for dosimetry and dating of natural zircons. Talc a magnesium sheeted silicate exhibits ESR derivative spectrum characterized the presence of Fe3+ at g=4.28 and the HF-sixtet Mn2+ signals due to possible substitution of Fe3+ and Mn2+ in the Mg2+ octahedral sites, respectively. The enhancement of the Mn2+ sixtet by γ-irradiation increases the area occupied by the signals which makes it difficult to use for dosimetric applications

  17. ESR studies of redox-active PMNT-PEG-PMNT polymer

    The paper presents the electron spin resonance (ESR) measurements of nitroxide radical-containing PMNT-PEG-PMNT triblock copolymer in different solvents: water, dimethyl formamide (DMF) and chloroform. Temperature dependence of electron spin resonance spectra were measured for each probe and several spectroscopic parameters describing physical properties, such as g-spectroscopic splitting factor value, resonance field (Hr), peak-to-peak line width (ΔHpp) and correlation time (τ) were calculated and discussed. For the determination of the parameters characterizing the dynamics of TEMPO radicals in complex spectra the computer resolution enhancement method (CREM) and EasySpin software for ESR spectra simulations were used. - Highlights: • We present ESR measurements of nitroxide radical-containing PMNT-PEG-PMNT copolymer. • We found triblock copolymer PMNT-PEG-PMNT chain state depends on solvent polarity. • In less polar solvents PMNT-PEG-PMNT collapses, in more polar it swells. • The CREM method and EasySpin simulating help analyzing complex ESR spectra

  18. Study on ESR and inter-related properties of vacuum-dehydrated nanotubed titanic acid

    Nanotubed titanic acid (H2Ti2O4(OH)2) is a novel kind of material. The electron spin resonance (ESR) and inter-related properties of its vacuum-dehydrated product were investigated by means of transmission electron microscopic, X-ray diffraction, ESR, diffuse reflectance spectra. The results showed that after treatment under vacuum (-0.1 MPa) at 100 degree sign C, single-electron-trapped oxygen vacancies (SETOV), characterized by a symmetrical ESR signal (g=2.003), were generated in nanotubed H2Ti2O4(OH)2 crystal lattice. The g=2.003 ESR signal intensity (IESR) increased with treatment time. SETOV played the role of F centers, the visible-light absorption power of vacuum-dehydrated H2Ti2O4(OH)2 was proportional to IESR. During vacuum dehydration at 100 degree sign C, the H2Ti2O4(OH)2 nanotubes shortened but its crystalline form kept unchanged. The formation mechanism of SETOV was discussed

  19. ESR study of radiation damage in pyrimidines. Progress report, August 1, 1975--April 1, 1976

    Benson, B.W.

    1976-04-01

    The primary objective of this project is to develop general mechanisms for radiation damage to biomolecules using substituted pyrimidines as a model system. Results this year include a single crystal ESR study of 5-ethyl-5-isopropylbarbituric acid, development of the k-band microwave bridge, dose response measurements on methylated barbituric acid derivatives, and synthesis of several specifically deuterated uracil derivatives.

  20. ESR study of radiation damage in pyrimidines. Progress report, August 1, 1975--April 1, 1976

    The primary objective of this project is to develop general mechanisms for radiation damage to biomolecules using substituted pyrimidines as a model system. Results this year include a single crystal ESR study of 5-ethyl-5-isopropylbarbituric acid, development of the k-band microwave bridge, dose response measurements on methylated barbituric acid derivatives, and synthesis of several specifically deuterated uracil derivatives

  1. Identifying spins states on self assembled Si/SiGe quantum dots by means of ESR

    Self-assembled Si/SiGe quantum dots were systematically studied with ESR at 9.56 GHz. A set of multilayer structures were grown with molecular beam epitaxy with different vertical spacing between quantum dot layers and different dot sizes. An extensive characterization with transmission electron microscopy and atomic force microscopy provides good structural information of the ensembles of quantum dots. Furthermore the samples were characterized by photoluminescence. Two ESR signals were identified with g-factors around 1.9992 and 1.9994. Both signals show a small anisotropy in g-factors and linewidth with respect to the magnetic field along growth and in-plane directions. Spin-relaxation times T1 are determined with continuous wave ESR saturation measurements to be of the order of 10 μs. The spin dephasing times yield values up to 500 ns. Illumination with sub-bandgap light changes the relative intensity of the two signals. Based on calculations of the electronic structure of the heterostructures a qualitative model allows us to relate the two ESR signals to s- and p-like-states on the quantum dots.

  2. ESR studies of redox-active PMNT-PEG-PMNT polymer

    Bednarowicz, M., E-mail: magda.bednarowicz@gmail.com [Medical Physics Division, Physics Department of Adam Mickiewicz University of Poznań, NanoBioMedical Centre, Umultowska 85 St, 61-614 Poznań (Poland); Dobosz, B.; Krzyminiewski, R.; Hałupka-Bryl, M.; Deptuła, T. [Medical Physics Division, Physics Department of Adam Mickiewicz University of Poznań, NanoBioMedical Centre, Umultowska 85 St, 61-614 Poznań (Poland); Nagasaki, Y. [Department of Materials Science, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8573 (Japan); Master' s School of Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8575 (Japan); Satellite Laboratory, International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8573 (Japan)

    2015-07-01

    The paper presents the electron spin resonance (ESR) measurements of nitroxide radical-containing PMNT-PEG-PMNT triblock copolymer in different solvents: water, dimethyl formamide (DMF) and chloroform. Temperature dependence of electron spin resonance spectra were measured for each probe and several spectroscopic parameters describing physical properties, such as g-spectroscopic splitting factor value, resonance field (H{sub r}), peak-to-peak line width (ΔH{sub pp}) and correlation time (τ) were calculated and discussed. For the determination of the parameters characterizing the dynamics of TEMPO radicals in complex spectra the computer resolution enhancement method (CREM) and EasySpin software for ESR spectra simulations were used. - Highlights: • We present ESR measurements of nitroxide radical-containing PMNT-PEG-PMNT copolymer. • We found triblock copolymer PMNT-PEG-PMNT chain state depends on solvent polarity. • In less polar solvents PMNT-PEG-PMNT collapses, in more polar it swells. • The CREM method and EasySpin simulating help analyzing complex ESR spectra.

  3. The use of ESR technique for assessment of heating temperatures of archaeological lentil samples

    Aydaş, Canan; Engin, Birol; Dönmez, Emel Oybak; Belli, Oktay

    2010-01-01

    Heat-induced paramagnetic centers in modern and archaeological lentils ( Lens culinaris, Medik.) were studied by X-band (9.3 GHz) electron spin resonance (ESR) technique. The modern red lentil samples were heated in an electrical furnace at increasing temperatures in the range 70-500 °C. The ESR spectral parameters (the intensity, g-value and peak-to-peak line width) of the heat-induced organic radicals were investigated for modern red lentil ( Lens culinaris, Medik.) samples. The obtained ESR spectra indicate that the relative number of heat-induced paramagnetic species and peak-to-peak line widths depends on the temperature and heating time of the modern lentil. The g-values also depend on the heating temperature but not heating time. Heated modern red lentils produced a range of organic radicals with g-values from g = 2.0062 to 2.0035. ESR signals of carbonised archaeological lentil samples from two archaeological deposits of the Van province in Turkey were studied and g-values, peak-to-peak line widths, intensities and elemental compositions were compared with those obtained for modern samples in order to assess at which temperature these archaeological lentils were heated in prehistoric sites. The maximum temperatures of the previous heating of carbonised UA5 and Y11 lentil seeds are as follows about 500 °C and above 500 °C, respectively.

  4. Alanine ESR dosimetry as a travelling dosimetric system for intercomparison purposes

    Bartolotta, A. (Palermo Univ. (Italy). Ist. di Fisica); Onori, S.; Pantaloni, M. (Istituto Superiore di Sanita, Rome (Italy). Lab. di Fisica)

    1990-01-01

    The major features of the ESR alanine dosimetry set up at the ISS are discussed, with particular regards to those aspects which render it suitable as travelling dosimetric system, both for photon and electron beams. The main results of an intercomparison program among the routine dosimetric systems used at the Italian industrial irradiation plants are shown.

  5. Consideration on detection of irradiated rainbow trout by ESR method and 2-alkylcyclobutanone analysis

    Relative ESR strength of rib, backbone and opercular bone from irradiated culture rainbow trout was direct proportional to dose between 0.56kGy and 5.7kGy. Relative ESR strength of rib was higher than that of backbone. Although only 5mg of otolith was obtained from one rainbow trout, bone density of otolith is so high that relative ESR strength of otolith showed about 20-fold higher value than that of rib. In GCMS-SIM analysis of RGB, radiolytic compounds of lipid of fish meat, the amount of both DCB and TCB formed, estimated from ion concentrations of m/z98, were direct proportional to dose between 1.1kGy and 11.1kGy. Neither DCB nor TCB was detected in unirradiated sample. The ratio of amount of DCB formed to amount of TCB formed was nearly 4.4, which is the ratio of palmitic acid content to stearic acid content in rainbow trout, denoted in Standard Tables of Food Composition in Japan; Lipid composition of Foods. Finally, we propose to use detection of radiolytic compound, RCB, and measurement of ESR of high-density bone together for reliable identification of irradiated fish

  6. Consideration on detection of irradiated rainbow trout by ESR method and 2-alkylcyclobutanone analysis

    Relative ESR strength of rib, backbone and opercular bone from irradiated culture rainbow trout was direct proportional to dose between 0.56kGy and 5.7kGy. Relative ESR strength of rib was higher than that of backbone. Although only 5mg of otolith was obtained from one rainbow trout, bone density of otolith is so high that relative ESR strength of otolith showed about 20-fold higher value than that of rib. In GCMS-SIM analysis of RCB, radiolytic compounds of lipid of fish meat, the amount of both DCB and TCB formed, estimated from ion concentrations of m/z98, were direct proportional to dose between 1.1kGy and 11.1kGy. Neither DCB nor TCB was detected in unirradiated sample. The ratio of amount of DCB formed to amount of TCB formed was nearly 4.4, which is the ratio of palmitic acid content to stearic acid content in rainbow trout, denoted in Standard Tables of Food Composition in Japan; Lipid composition of Foods. Finally, we propose to use detection of radiolytic compound, RCB, and measurement of ESR of high-density bone together for reliable identification of irradiated fish. (author)

  7. Dynamic nuclear polarization-magnetic resonance imaging at low ESR irradiation frequency for ascorbyl free radicals

    Ito, Shinji; Hyodo, Fuminori

    2016-02-01

    Highly water-soluble ubiquinone-0 (CoQ0) reacts with ascorbate monoanion (Asc) to mediate the production of ascorbyl free radicals (AFR). Using aqueous reaction mixture of CoQ0 and Asc, we obtained positively enhanced dynamic nuclear polarization (DNP)-magnetic resonance (MR) images of the AFR at low frequency (ranging from 515 to 530 MHz) of electron spin resonance (ESR) irradiation. The shape of the determined DNP spectrum was similar to ESR absorption spectra with doublet spectral peaks. The relative locational relationship of spectral peaks in the DNP spectra between the AFR (520 and 525 MHz), 14N-labeled carbamoyl-PROXYL (14N-CmP) (526.5 MHz), and Oxo63 (522 MHz) was different from that in the X-band ESR spectra, but were similar to that in the 300-MHz ESR spectra. The ratio of DNP enhancement to radical concentration for the AFR was higher than those for 14N-CmP, Oxo63, and flavin semiquinone radicals. The spectroscopic DNP properties observed for the AFR were essentially the same as those for AFR mediated by pyrroloquinoline quinone. Moreover, we made a success of in vivo DNP-MR imaging of the CoQ0-mediated AFR which was administered by the subcutaneous and oral injections as an imaging probe.

  8. ACOUSTICAL STANDARDS NEWS.

    Blaeser, Susan B; Struck, Christopher J

    2016-03-01

    American National Standards (ANSI Standards) developed by Accredited Standards Committees S1, S2, S3, S3/SC 1, and S12 in the areas of acoustics, mechanical vibration and shock, bioacoustics, animal bioacoustics, and noise, respectively, are published by the Acoustical Society of America (ASA). In addition to these standards, ASA publishes a catalog of Acoustical American National Standards. To receive a copy of the latest Standards catalog, please contact Susan B. Blaeser.Comments are welcomed on all material in Acoustical Standards News.This Acoustical Standards News section in JASA, as well as the National Catalog of Acoustical Standards and other information on the Standards Program of the Acoustical Society of America, are available via the ASA home page: http://acousticalsociety.org. PMID:27036268

  9. Radiation-induced signals of gypsum crystals analysed by ESR and TL techniques applied to dating

    Aydas, Canan [Turkish Atomic Energy Authority, Saraykoey Nuclear Research and Training Center, 06983 Saray-Kazan, Ankara (Turkey); Engin, Birol, E-mail: birol_engin65@yahoo.co [Turkish Atomic Energy Authority, Saraykoey Nuclear Research and Training Center, 06983 Saray-Kazan, Ankara (Turkey); Aydin, Talat [Turkish Atomic Energy Authority, Saraykoey Nuclear Research and Training Center, 06983 Saray-Kazan, Ankara (Turkey)

    2011-02-15

    Natural crystals of terrestrial gypsum were investigated concerning the radiation effects on Electron spin resonance (ESR) and Thermoluminescence (TL) properties and their application for geological dating. ESR signals of Fe{sup 3+}, Mn{sup 2+}, G1 (SO{sub 3}{sup -}, g = 2.003) and G2 (SO{sub 4}{sup -}, g{sub ||} =2.018g{sub perpendicular} =2.009) centers were observed. The thermal stability and dose response of the ESR signals were found to be suitable for an age determination using a signal at g = 2.009. The intensity of this center increased with {gamma}-radiation and the additive dose method for this ESR center yielded accumulated dose GD of 67.4 {+-} 10.1 Gy. Using U, Th and K contents plus the cosmic-ray contribution, a dose rate of 1.92 {+-} 0.22 mGy/year has been obtained. We have determined the ESR age of the gypsums to be (35 {+-} 4) x 10{sup 3} years. TL peaks at 157 and 278 {sup o}C were observed. By using initial rise method the thermal activation energy of 278 {sup o}C TL peak was found to be underestimated, probably due to the thermal quenching. Activation energies and frequency factors obtained by the method of varying the heating rate indicate lifetime of 4.09 x 10{sup 7} years (at 15 {sup o}C) for 278 {sup o}C peak. The additive dose method applied to this TL peak yielded GD of 75 {+-} 11 Gy. The corresponding TL age using the 278 {sup o}C TL peak was found to be (39 {+-} 5) x 10{sup 3} years for gypsum sample. The TL age of this sample is consistent with the ESR age within experimental error limits. The obtained ESR and TL ages are not consistent with the expectations of geologists. This contradiction is probably due to the repeatedly recrystallisation of gypsum samples under the environmental conditions after their formation in the upper Miocene-Pliocene Epoch.

  10. Radiation-induced signals of gypsum crystals analysed by ESR and TL techniques applied to dating

    Aydaş, Canan; Engin, Birol; Aydın, Talat

    2011-02-01

    Natural crystals of terrestrial gypsum were investigated concerning the radiation effects on Electron spin resonance (ESR) and Thermoluminescence (TL) properties and their application for geological dating. ESR signals of Fe 3+, Mn 2+, G1 ( SO3-, g = 2.003) and G2 ( SO4-, g∥=2.018g⊥=2.009) centers were observed. The thermal stability and dose response of the ESR signals were found to be suitable for an age determination using a signal at g = 2.009. The intensity of this center increased with γ-radiation and the additive dose method for this ESR center yielded accumulated dose GD of 67.4 ± 10.1 Gy. Using U, Th and K contents plus the cosmic-ray contribution, a dose rate of 1.92 ± 0.22 mGy/year has been obtained. We have determined the ESR age of the gypsums to be (35 ± 4) × 10 3 years. TL peaks at 157 and 278 °C were observed. By using initial rise method the thermal activation energy of 278 °C TL peak was found to be underestimated, probably due to the thermal quenching. Activation energies and frequency factors obtained by the method of varying the heating rate indicate lifetime of 4.09 × 10 7 years (at 15 °C) for 278 °C peak. The additive dose method applied to this TL peak yielded GD of 75 ± 11 Gy. The corresponding TL age using the 278 °C TL peak was found to be (39 ± 5) × 10 3 years for gypsum sample. The TL age of this sample is consistent with the ESR age within experimental error limits. The obtained ESR and TL ages are not consistent with the expectations of geologists. This contradiction is probably due to the repeatedly recrystallisation of gypsum samples under the environmental conditions after their formation in the upper Miocene-Pliocene Epoch.

  11. Studies of radiolytic and self-radiolytic processes in polyacrylic hydrogels using ESR spectrometry

    Due to its remarkable capacity of water retaining capacity, polyacrylic (PAA) hydrogels represent an interesting alternative for tritium (tritiated water-HTO) liquid waste trapping. The study was focused on radiolytic processes in PAA:HTO systems derived from irradiation of polymeric network by decay of tritium atoms from HTO. The aim of these studies is to identify the polymeric structures and the optimal storage conditions. ESR studies of radiolytic processes were performed on dry polyacrylic acid (PAA) and polyacrylic based hydrogels samples irradiated at 77 K. In this study we observed the effect of swelling capacity of hydrogel on the formation of free radicals. In the ESR spectra of irradiated PAA a signal with quintet structure was identified and assigned in accordance with the literature, to a radical in α position with respect to the carboxylic group. We also identified a triplet that was ascribed to a radical resulting from fragmentation of polymeric main chain. In case of PAA hydrogels signals were identified and ascribed to the HO radical resulted from water radiolysis, R-OO radicals resulted from the presence of atmospheric O2 in samples as well a signal with quintet structure less split than in the dry polymer. This signal was ascribed to a radical bound to the polymeric main chain in α position relative to carboxylic group. The decrease of split parameter is determined by tension of the main chain as a result of swelling, associated with increase of θ angle between px axis of Cα radical and the Cα Cβ and Hβ plane. The ESR analysis of labelled hydrogels reveals the presence of HO and COO radicals produced by internal primary effect. ESR analysis of PAA:HTO samples indicate the preponderant role of the internal primary effect in selfradiolytic effects in concordance with the role of secondary effects which are blocked in the ESR study due to material freezing. (authors)

  12. Studies of radiolytic and self-radiolytic processes in polyacrylic hydrogels using ESR spectrometry

    Full text: Due to the remarkable capacity of water retaining, polyacrylic (PAA) hydrogels represent an interesting alternative for tritium (tritiated water-HTO) liquid wastes trapping. The study was developed on radiolytic processes in PAA:HTO systems derived from irradiation of polymeric network by decay of tritium atoms from HTO. The aim of these studies is the identification of polymeric structures and optimal storage conditions. ESR studies of radiolytic processes were carried out on dry polyacrylic acid (PAA) and polyacrylic based hydrogels irradiated and determined at 77 K. In the study we observed the effect of swelling capacity of hydrogel on the formation of free radicals. In the ESR spectra of irradiated PAA was identified a signal with quintet structure assigned, according to the literature, to radical from a position referred to the carboxylic group. We also identified a triplet assigned to a radical resulted by fragmentation of polymeric main chain. In the case of PAA hydrogels signals were identified and attributed to HO radical resulted from water radiolysis, R-OO radicals resulted from the presence of atmospheric O2 in samples and a signal with quintet structure more less split like dry polymer. The signal is attributed to a radical from the polymeric main chain in α position referred to carboxylic group. The decrease of split parameter is determined by tension of main chain as result of swelling, associated with increase of θ angle between px axis of Cα radical and the Cα Cβ Hβ plane. ESR analysis of labelled hydrogels indicates the presence of HO and COO radicals resulted from internal primary effect. ESR analysis of PAA:HTO samples indicates the preponderant role of the internal primary effect in self radiolytic effects in concordance with the role of secondary effects stopped in ESR study due to freeze material. (author)

  13. Association between estrogen receptor alpha (ESR1) gene polymorphisms and severe preeclampsia.

    Molvarec, Attila; Vér, Agota; Fekete, Andrea; Rosta, Klára; Derzbach, László; Derzsy, Zoltán; Karádi, István; Rigó, János

    2007-03-01

    Associations have been reported between estrogen receptor alpha (ESR1) gene polymorphisms and various pathological conditions, including cardiovascular diseases. Our aim was to investigate whether two polymorphisms of the ESR1 gene (ESR1 c.454 -397T>C: PvuII restriction site and c.454 -351A>G: XbaI restriction site) are associated with preeclampsia. In a case-control study, we analyzed blood samples from 119 severely preeclamptic patients and 103 normotensive, healthy pregnant women using the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method. All of the women were Caucasian. There was no association between severe preeclampsia and the PvuII and XbaI ESR1 gene polymorphisms separately. However, with the simultaneous carriage of both polymorphisms, the TT/AA genotype combination was significantly more frequent in severely preeclamptic patients than in healthy control subjects (24.4% vs. 9.7%, p=0.003), whereas the TT/AG combination was significantly less frequent in the severely preeclamptic group than in the control group (5.0% vs. 18.4%, p=0.002). According to the haplotype estimation, the homozygous T-A haplotype carriers had an increased risk of severe preeclampsia independent of maternal age, prepregnancy BMI, primiparity and smoking status (adjusted odds ratio [OR]: 4.36, 95% confidence interval [CI]: 1.65-11.53). The GG genotype of the XbaI polymorphism was associated with a lower risk of fetal growth restriction in patients with severe preeclampsia (OR: 0.23, 95% CI: 0.07-0.73). In conclusion, the homozygous T-A haplotype carriers of ESR1 PvuII and XbaI polymorphisms showed an increased risk of severe preeclampsia. In addition, the GG genotype of the XbaI polymorphism decreased the risk of fetal growth restriction in severely preeclamptic patients. PMID:17510501

  14. Heterogeneity and clinical significance of ESR1 mutations in ER-positive metastatic breast cancer patients receiving fulvestrant.

    Spoerke, Jill M; Gendreau, Steven; Walter, Kimberly; Qiu, Jiaheng; Wilson, Timothy R; Savage, Heidi; Aimi, Junko; Derynck, Mika K; Chen, Meng; Chan, Iris T; Amler, Lukas C; Hampton, Garret M; Johnston, Stephen; Krop, Ian; Schmid, Peter; Lackner, Mark R

    2016-01-01

    Mutations in ESR1 have been associated with resistance to aromatase inhibitor (AI) therapy in patients with ER+ metastatic breast cancer. Little is known of the impact of these mutations in patients receiving selective oestrogen receptor degrader (SERD) therapy. In this study, hotspot mutations in ESR1 and PIK3CA from ctDNA were assayed in clinical trial samples from ER+ metastatic breast cancer patients randomized either to the SERD fulvestrant or fulvestrant plus a pan-PI3K inhibitor. ESR1 mutations are present in 37% of baseline samples and are enriched in patients with luminal A and PIK3CA-mutated tumours. ESR1 mutations are often polyclonal and longitudinal analysis shows distinct clones exhibiting divergent behaviour over time. ESR1 mutation allele frequency does not show a consistent pattern of increases during fulvestrant treatment, and progression-free survival is not different in patients with ESR1 mutations compared with wild-type patients. ESR1 mutations are not associated with clinical resistance to fulvestrant in this study. PMID:27174596

  15. AST Launch Vehicle Acoustics

    Houston, Janice; Counter, D.; Giacomoni, D.

    2015-01-01

    The liftoff phase induces acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are then used in the prediction of internal vibration responses of the vehicle and components which result in the qualification levels. Thus, predicting these liftoff acoustic (LOA) environments is critical to the design requirements of any launch vehicle. If there is a significant amount of uncertainty in the predictions or if acoustic mitigation options must be implemented, a subscale acoustic test is a feasible pre-launch test option to verify the LOA environments. The NASA Space Launch System (SLS) program initiated the Scale Model Acoustic Test (SMAT) to verify the predicted SLS LOA environments and to determine the acoustic reduction with an above deck water sound suppression system. The SMAT was conducted at Marshall Space Flight Center and the test article included a 5% scale SLS vehicle model, tower and Mobile Launcher. Acoustic and pressure data were measured by approximately 250 instruments. The SMAT liftoff acoustic results are presented, findings are discussed and a comparison is shown to the Ares I Scale Model Acoustic Test (ASMAT) results.

  16. Suitability of thermoluminescence, chemiluminescence, ESR and viscosity measurements as detection method for the irradiation of medicinal herbs; Eignung von Thermolumineszenz-, Chemilumineszenz-, ESR- und Viskositaetsmessungen zur Identifizierung strahlenbehandelter Arzneidrogen

    Schuettler, C.; Gebhardt, G.; Stock, A.; Helle, N.; Boegl, K.W.

    1993-12-31

    Chemiluminescence, electron spin resonance, thermoluminescence and viscosity measurements have been investigated for their suitability as detection method for the irradiation of the medicinal herbs anise seeds (anisi fructus), valerian roots (valerianae radix), redberry leaves (uvae ursi folium), birch leaves (betulae folium), greek hay seeds (foenugraeci semen), cayenne pepper (capsici fructus acer), black-aldertee bark (frangulae cortex), fennel fruits (feoniculi fructus), rose hip shells (cynosbati fructus), coltsfoot (farfarae folium), acorus roots (calami rhizoma), chamomile flowers (matricariae flos), caraway (carvi fructus), lavender flowers (lavandulae flos), linseed (lini semen), lime tree flowers (tiliae flos), St. Mary`s thistle fruit (cardui mariae herba), lemon balm (melissae folium), java tea (orthosiphonis folium), peppermint (menthae piperitae folium), sage leaves (salviae folium), scouring rush (equiseti herba), senna leaves (sennae folium), plantain herbs (plantaginis lanceolata herba), thyme herbs (thymi herba), juniper berries (juniperi fructus), hawthorne herbs (crataegi folium), wheat starch (amylum tritici) and wormwood (absinthii herba). Depending on the herbs, the methods used were more or less suitable. Chemiluminescence measurements showed the smallest differences between untreated and irradiated samples whereas thermoluminescence measurements on isolated minerals from the vegetable drugs gave better results. In some herbs radiation-specific radicals could be identified by ESR spectroscopy. Viscosity measurement is suitable for some herbs as fast and inexpensive method for screening. (orig.) [Deutsch] Die Eignung von Chemilumineszenz-, ESR-, Thermolumineszenz- und Viskositaetsmessungen als Nachweismethode fuer die Behandlung von Arzneidrogen mit ionisierenden Strahlen wurde an Anis, Baldrianwurzel, Baerentraubenblaettern, Birkenblaettern, Bockshornsamen, Cayennepfeffer, Faulbaumrinde, Fenchel, Hagebuttenschalen, Huflattichblaettern

  17. Contribution of polymorphisms in ESR1, ESR2, FSHR, CYP19A1, SHBG and NRIP1 genes to migraine susceptibility in Turkish population

    Salih Coşkun; Yavuz Yücel; Abdullah Çim; Beyhan Cengiz; Serdar Oztuzcu; Sefer Varol; Hasan H. Özdemir; Ertuğrul Uzar

    2016-03-01

    Migraine, a highly prevalent headache disorder, is regarded as a polygenic multifactorial disease. Single-nucleotide polymorphisms (SNPs) in the genes that involved in sex hormone metabolism may comprise risk for migraine, but the results of previous genetic association studies are conflicting. The aim of this study was to evaluate genetic variants in genes involved in oestrogen receptor and oestrogen hormone metabolism in a Turkish population. A total of 12 SNPs in the ESR1, ESR2, FSHR, CYP19A1, SHBG and NRIP1 genes were genotyped in 142 migraine cases and 141 nonmigraine controls, using a BioMark 96.96 dynamic array system. In addition, gene–gene interactions were analysed using generalized multifactor dimensionality reduction (GMDR) methods. According to GMDR analysis, our results indicated that there was a significant association between migraine and gene–gene interaction among the CYP19A1, FSHR, ESR1 and NRIP1. Single-gene variant analysis showed that a significant association was observed between the TT genotype of rs10046 and migraine susceptibility.When the analysis was performed only in women, the GG genotype of rs2229741 was different between migraineurs and controls. When the female migraine patients were divided into two groups, migraine related to menstruation (MRM) or migraine not related to menstruation (MNRM), GG genotype of rs726281 was significantly associated with MRM. These results suggested that rs10046 could play a potential role in migraine susceptibility in Turkish population. Also, the rare GG genotype of rs726281 appears to influence migraine susceptibility in a recessive manner in MRM subgroup of female patients. In addition, variant GG genotype of rs2229741 may reduce the risk of migraine in Turkish women.

  18. Contribution of polymorphisms in ESR1, ESR2, FSHR, CYP19A1, SHBG, and NRIP1 genes to migraine susceptibility in Turkish population.

    CoŞkun, Salih; Yůcel, Yavuz; Çim, Abdullah; Cengiz, Beyhan; Oztuzcu, Serdar; Varol, Sefer; Özdemir, Hasan H; Uzar, ErtuĞrul

    2016-03-01

    Migraine, a highly prevalent headache disorder, is regarded as a polygenic multifactorial disease. Single-nucleotide polymorphisms (SNPs) in the genes that involved in sex hormone metabolism may comprise risk for migraine, but the results of previous genetic association studies are conflicting. The aim of this study was to evaluate genetic variants in genes involved in oestrogen receptor and oestrogen hormone metabolism in a Turkish population. A total of 12 SNPs in the ESR1, ESR2, FSHR, CYP19A1, SHBG and NRIP1 genes were genotyped in 142 migraine cases and 141 nonmigraine controls, using a BioMark 96.96 dynamic array system. In addition, gene-gene interactions were analysed using generalized multifactor dimensionality reduction (GMDR) methods. According to GMDR analysis, our results indicated that there was a significant association between migraine and gene-gene interaction among the CYP19A1, FSHR, ESR1 and NRIP1. Single-gene variant analysis showed that a significant association was observed between the TT genotype of rs10046 and migraine susceptibility.When the analysis was performed only in women, the GG genotype of rs2229741 was different between migraineurs and controls.When the female migraine patients were divided into two groups, migraine related to menstruation (MRM) or migraine not related to menstruation (MNRM), GG genotype of rs726281 was significantly associated with MRM. These results suggested that rs10046 could play a potential role in migraine susceptibility in Turkish population. Also, the rare GG genotype of rs726281 appears to influence migraine susceptibility in a recessive manner in MRM subgroup of female patients. In addition, variant GG genotype of rs2229741 may reduce the risk of migraine in Turkish women. PMID:27019440

  19. Acoustic streaming in microchannels

    Tribler, Peter Muller

    , and experimental results for the streaming-induced drag force dominated motion of particles suspended in a water-filled microchannel supporting a transverse half-wavelength resonance. The experimental and theoretical results agree within a mean relative dierence of approximately 20%, a low deviation given state......This thesis presents studies of boundary-driven acoustic streaming in microfluidic channels, which is a steady flow of the fluid initiated by the interactions of an oscillating acoustic standing wave and the rigid walls of the microchannel. The studies present analysis of the acoustic resonance......, the acoustic streaming flow, and the forces on suspended microparticles. The work is motivated by the application of particle focusing by acoustic radiation forces in medical, environmental and food sciences. Here acoustic streaming is most often unwanted, because it limits the focusability of particles...

  20. Vibro-acoustics

    Nilsson, Anders

    2015-01-01

    This three-volume book gives a thorough and comprehensive presentation of vibration and acoustic theories. Different from traditional textbooks which typically deal with some aspects of either acoustic or vibration problems, it is unique of this book to combine those two correlated subjects together. Moreover, it provides fundamental analysis and mathematical descriptions for several crucial phenomena of Vibro-Acoustics which are quite useful in noise reduction, including how structures are excited, energy flows from an excitation point to a sound radiating surface, and finally how a structure radiates noise to a surrounding fluid. Many measurement results included in the text make the reading interesting and informative. Problems/questions are listed at the end of each chapter and the solutions are provided. This will help the readers to understand the topics of Vibro-Acoustics more deeply. The book should be of interest to anyone interested in sound and vibration, vehicle acoustics, ship acoustics and inter...

  1. Springer handbook of acoustics

    2014-01-01

    Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience, and electronics. The Springer Handbook of Acoustics is also in his 2nd edition an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents. This new edition of the Handbook features over 11 revised and expanded chapters, new illustrations, and 2 new chapters covering microphone arrays  and acoustic emission.  Updated chapters contain the latest research and applications in, e.g. sound propagation in the atmosphere, nonlinear acoustics in fluids, building and concert hall acoustics, signal processing, psychoacoustics, computer music, animal bioacousics, sound intensity, modal acoustics as well as new chapters on microphone arrays an...

  2. A study of the radiation chemistry of poly(chlorotrifluoroethylene) by ESR spectroscopy[Poly(chlorotrifluoroethylene); {gamma}-radiolysis; ESR study; Radicals; G-values

    Hill, D.J.T. E-mail: hill@chemistry.uq.edu.au; Thurecht, K.J.; Whittaker, A.K

    2003-12-01

    The ESR spectra of poly(chlorotrifluoroethylene) were recorded following {gamma}-radiolysis under vacuum at room temperature and 77 K. The very broad spectrum at 77 K revealed little fine structure with which to identity the radicals formed upon irradiation, but subsequent photobleaching and annealing studies, together with radiolytic studies at higher temperatures, afforded scope for making radical assignments. Both main-chain radicals and a range of chain-end radicals have been identified. The G-values for radical formation were 1.55, 0.36 and 0.32 at 77 K, 273 K and room temperature, respectively.

  3. ESR and EISCAT observations of the response of the cusp and cleft to IMF orientation changes

    I. W. McCrea

    Full Text Available We report observations of the cusp/cleft ionosphere made on December 16th 1998 by the EISCAT (European incoherent scatter VHF radar at Tromsø and the EISCAT Svalbard radar (ESR. We compare them with observations of the dayside auroral luminosity, as seen by meridian scanning photometers at Ny Ålesund and of HF radar backscatter, as observed by the CUTLASS radar. We study the response to an interval of about one hour when the interplanetary magnetic field (IMF, monitored by the WIND and ACE spacecraft, was southward. The cusp/cleft aurora is shown to correspond to a spatially extended region of elevated electron temperatures in the VHF radar data. Initial conditions were characterised by a northward-directed IMF and cusp/cleft aurora poleward of the ESR. A strong southward turning then occurred, causing an equatorward motion of the cusp/cleft aurora. Within the equatorward expanding, southward-IMF cusp/cleft, the ESR observed structured and elevated plasma densities and ion and electron temperatures. Cleft ion fountain upflows were seen in association with elevated ion temperatures and rapid eastward convection, consistent with the magnetic curvature force on newly opened field lines for the observed negative IMF By. Subsequently, the ESR beam remained immediately poleward of the main cusp/cleft and a sequence of poleward-moving auroral transients passed over it. After the last of these, the ESR was in the polar cap and the radar observations were characterised by extremely low ionospheric densities and downward field-aligned flows. The IMF then turned northward again and the auroral oval contracted such that the ESR moved back into the cusp/cleft region. For the poleward-retreating, northward-IMF cusp/cleft, the convection flows were slower, upflows were weaker and the electron density and temperature enhancements were less structured. Following the northward turning, the bands of high electron temperature and cusp

  4. Localized Acoustic Surface Modes

    Farhat, Mohamed

    2015-08-04

    We introduce the concept of localized acoustic surface modes (ASMs). We demonstrate that they are induced on a two-dimensional cylindrical rigid surface with subwavelength corrugations under excitation by an incident acoustic plane wave. Our results show that the corrugated rigid surface is acoustically equivalent to a cylindrical scatterer with uniform mass density that can be represented using a Drude-like model. This, indeed, suggests that plasmonic-like acoustic materials can be engineered with potential applications in various areas including sensing, imaging, and cloaking.

  5. Shallow Water Acoustic Laboratory

    Federal Laboratory Consortium — FUNCTION: Supports experimental research where high-frequency acoustic scattering and surface vibration measurements of fluid-loaded and non-fluid-loaded structures...

  6. Handbook of Engineering Acoustics

    Möser, Michael

    2013-01-01

    This book examines the physical background of engineering acoustics, focusing on empirically obtained engineering experience as well as on measurement techniques and engineering methods for prognostics. Its goal is not only to describe the state of art of engineering acoustics but also to give practical help to engineers in order to solve acoustic problems. It deals with the origin, the transmission and the methods of the abating different kinds of air-borne and structure-borne sounds caused by various mechanisms – from traffic to machinery and flow-induced sound. In addition the modern aspects of room and building acoustics, as well as psychoacoustics and active noise control, are covered.

  7. Acoustic dispersive prism

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R.

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz-1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium.

  8. What Is an Acoustic Neuroma

    ... org Connect with us! What is an Acoustic Neuroma? Each heading slides to reveal information. Important Points ... Neuroma Important Points To Know About an Acoustic Neuroma An acoustic neuroma, also called a vestibular schwannoma, ...

  9. The ESR dating of fossil enamel samples from palaeo-anthropological and Palaeolithic sites of Early Pleistocene

    The following problems regarding the ESR dating of fossil enamel samples from palaeo-anthropological and Palaeolithic sites of Early Pleistocene are discussed: 1) the applicability of exponential fitting in the additive method for reliable AD determination; 2) the thermo-stability of the g = 2.0018 line of hydroxyapatite and its influence on apparent ESR ages; 3) the right selection of U-uptake models; and 4) the effect of high U-content in enamel on the ESR ages. It is concluded that the ESR-EU ages of Early Pleistocene enamel samples can only be regarded as the lower limit of the true ages if no appropriate corrections for the factors discussed above are made

  10. The light magnet, coupling of electronic and nuclear angular momenta in optical NMR and ESR: Quantum theory

    Evans, M. W.

    1992-07-01

    Optical NMR and ESR is a recently introduced technique in which a circularly polarized laser (a "light magnet") is used in an NMR or ESR spectrometer to induce magnetization. The spectral consequencies are developed with a quantum theory similar to the rigorous theory of Zeeman splitting of Russell-Saunders states, a theory which is suitable for atoms and molecules with net electronic angular momentum, and in which the antisymmetric electronic polarizability is finite. The optical NMR and ESR Hamiltonians are developed with the Wigner-Eckhart Theorem. The circularly polarized laser shifts the original NMR or ESR resonance lines, and splits the shifted lines into analytically useful patterns. The theory gives Landé factors which are in agreement with an earlier, simple, semiclassical theory ( J. Phys. Chem.95, 2256-2260 (1991)).

  11. Study of a set of micrometeorites from Antarctica using magnetic and ESR methods coupled with micro-XRF

    A collection of iron-rich micrometeorites from Antarctica have been investigated using electron spin resonance (ESR) and conventional magnetic methods to establish a complete magnetic codification of their specific characteristics. Due to the high selectivity of the ESR, the spectra show that the amount and nature of the magnetic impurities contained in these tiny-sized samples, mainly Ni and Cr ions, significantly modify their ESR responses. This result provides a criterion, the Ni/Cr content (identified by spectroscopy), useful for a faithful classification of this class of extraterrestrial particles with close magnetic properties. We attempt to separate the contribution of the different magnetic ions in the ESR response. This method can be easily extended to other magnetic impurities

  12. Irradiation and ESR analysis temperature dependence of the gamma-ray response of alanine-polystyrene dosimeters

    Response characteristics of the alanine-polystyrene dosimeter were studied at an absorbed dose of 5 kGy over the low irradiation temperature range -196 ∼ 30oC, and the ESR analysis temperature range 0 ∼50oC in the dose range 0.1 ∼ 10 kGy. The irradiation temperature coefficient previously estimated for the temperature range from 0 ∼ 70oC (+0.24%/.oC) was verified down to -15oC, although about 8% lower values were obtained at -78 and -196oC based on the correction using the above coefficient. ESR intensity decreases with temperature during ESR analysis following the function of the reciprocal of absolute temperature based on Boltzmann's constant. The average temperature coefficient for three different dose levels during ESR analysis of the alanine-polystyrene dosimeter is -0.25%/K in the temperature range 0 ∼ 50oC. (Author)

  13. Electron spins in reduced dimensions. ESR spectroscopy on semiconductor heterostructures and spin chain compounds

    Lipps, Ferdinand

    2011-08-31

    Spatial confinement of electrons and their interactions as well as confinement of the spin dimensionality often yield drastic changes of the electronic and magnetic properties of solids. Novel quantum transport and optical phenomena, involving electronic spin degrees of freedom in semiconductor heterostructures, as well as a rich variety of exotic quantum ground states and magnetic excitations in complex transition metal oxides that arise upon such confinements, belong therefore to topical problems of contemporary condensed matter physics. In this work electron spin systems in reduced dimensions are studied with Electron Spin Resonance (ESR) spectroscopy, a method which can provide important information on the energy spectrum of the spin states, spin dynamics, and magnetic correlations. The studied systems include quasi onedimensional spin chain materials based on transition metals Cu and Ni. Another class of materials are semiconductor heterostructures made of Si and Ge. Part I deals with the theoretical background of ESR and the description of the experimental ESR setups used which have been optimized for the purposes of the present work. In particular, the development and implementation of axial and transverse cylindrical resonant cavities for high-field highfrequency ESR experiments is discussed. The high quality factors of these cavities allow for sensitive measurements on {mu}m-sized samples. They are used for the investigations on the spin-chain materials. The implementation and characterization of a setup for electrical detected magnetic resonance is presented. In Part II ESR studies and complementary results of other experimental techniques on two spin chain materials are presented. The Cu-based material Linarite is investigated in the paramagnetic regime above T>2.8 K. This natural crystal constitutes a highly frustrated spin 1/2 Heisenberg chain with ferromagnetic nearest-neighbor and antiferromagnetic next-nearestneighbor interactions. The ESR data

  14. Influence of electro slag remelting (esr) slags on remelted tool steel

    CaF/sub 2/ base synthetic slag is used during the electroslag remelting technique. ESR slags are refining components of steel. They are usually ionic conductors and in the liquid state conduct electrical current due to mobility of the ions. Physical properties of the slag such as electrical conductivity, viscosity, melting point, density, surface tension and chemical stability at operating temperature influence the removal of inclusions from the metal and subsequent chemical composition of the alloy. Three different type of molten slags system were used in the ESR process to produce different grades of tool steel. It was concluded that the selected lumps of fluorspar (CaF/sub 2/=98%) can be prefused to decrease the level of impurities and can be used in combination with other three-component slag to achieve the similar properties of end product as in the case of imported CaF/sub 2/ base slag. (author)

  15. Changes in molecular structure and properties of irradiated polymers of different compositions - ESR and NMR study

    Investigations of molecular structural changes in polymers during exposure to high energy radiation is the long term interest of the Polymer Materials and Radiation Group at the University of Queensland. Recently, the group had looked at a range of polymers including natural and synthetic rubbers, methacrylates and polyesters. The objective of the work has been to investigate the relationships between polymer structure and sensitivity towards high energy radiation, including gamma radiation. This report will focus on the Electron Spin Resonance (ESR) and Nuclear Magnetic Resonance (NMR) studies of the effects of gamma irradiation on these polymers. Other methods such as Gas Chromatography (GC), Gel Permeation Chromatography (GPC), Fourier Transformed Infra Red (FTIR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA) and Dynamic Mechanical Analysis (DMA) have also been used as these methods combine with ESR and NMR, to provide a more complete picture of the mechanism of the structural changes. (author)

  16. ESR Dosimetry for Atomic Bomb Survivors Using Shell Buttons and Tooth Enamel

    Ikeya, Motoji; Miyajima, Junko; Okajima, Shunzo

    1984-09-01

    Atomic bomb radiation doses to humans at Nagasaki and Hiroshima are investigated by electron spin resonance (ESR) from shell buttons and tooth enamel voluntarily supplied by survivors. A shell button gives a dose of 2.1± 0.2 Gy with ESR signals at g=2.001 and g=1.997 while the signal at g=1.997 for the tooth enamel of the same person is 1.9± 0.5 Gy. Other teeth show doses from about 0.5 Gy to 3 Gy. An apparent shielding converted to a concrete thickness is given using the T65D calculated in 1965. Teeth extracted during dental treatment should be preserved for cumulative radiation dosimetry.

  17. Sediment U, Th, K content analyzed using X-ray fluorescence spectrometry for ESR dating samples

    The accurate measurement of dose rate is the key issues to obtain reliable ESR age. In this article, we used X-ray fluorescence spectrometry to determine the U, Th, K content of the fluvial sediments. And the standard working curves were established using the national rock reference material. Setting the lower X-ray power and the matrix effect, U, Th, K content in the fluvial sediment were investigated. The results show that the method recovery rate of U and Th is less than 15%. Comparing with the measurement data from the α-counting and Atomic Spectrometry analysis, the dose rate difference is less than 5%. It shows that the X-ray fluorescence spectrometry method can fit for the requirement for obtaining the U, Th, K content of fluvial sediment for ESR dating. (authors)

  18. Regeneration of phenolic antioxidants from phenoxyl radicals: An ESR and electrochemical study of antioxidant hierarchy

    Jørgensen, Lars V.; Madsen, Helle L.; Thomsen, Marianne K.; Dragsted, Lars O.; Skibsted, Leif H.

    1999-01-01

    Radicals from the flavonoids quercetin, (+)-catechin, (+/-)-taxifolin and luteolin, and from all-rac-alpha-tocopherol have been generated electrochemically by one-electron oxidation in deaerated dimethylformamide (DMF), and characterised by electron spin resonance spectroscopy (ESR) after spin......-trapping by 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). Simulations of the ESR spectrum based on estimated coupling constants of the spin-trapped quercetin radical, confirmed that this antioxidant radical is oxygen-centered. The complex mixture of radicals, quinoid intermediates and stable two-electron oxidation...... antioxidants from their oxidation products with a regeneration index (defined as moles regenerated of the oxidised phenolic antioxidant divided with moles of all-rac-alpha-tucopherol consumed) of 0.90 +/- 0.16 for quercetin, 0.48 +/- 0.11 for (+)-catechin, 0.48 +/- 0.06 for (+/-)-taxifolin and 0.50 +/- 0...

  19. TL and ESR based identification of gamma-irradiated frozen fish using different hydrolysis techniques

    Ahn, Jae-Jun; Akram, Kashif; Shahbaz, Hafiz Muhammad; Kwon, Joong-Ho

    2014-12-01

    Frozen fish fillets (walleye Pollack and Japanese Spanish mackerel) were selected as samples for irradiation (0-10 kGy) detection trials using different hydrolysis methods. Photostimulated luminescence (PSL)-based screening analysis for gamma-irradiated frozen fillets showed low sensitivity due to limited silicate mineral contents on the samples. Same limitations were found in the thermoluminescence (TL) analysis on mineral samples isolated by density separation method. However, acid (HCl) and alkali (KOH) hydrolysis methods were effective in getting enough minerals to carry out TL analysis, which was reconfirmed through the normalization step by calculating the TL ratios (TL1/TL2). For improved electron spin resonance (ESR) analysis, alkali and enzyme (alcalase) hydrolysis methods were compared in separating minute-bone fractions. The enzymatic method provided more clear radiation-specific hydroxyapatite radicals than that of the alkaline method. Different hydrolysis methods could extend the application of TL and ESR techniques in identifying the irradiation history of frozen fish fillets.

  20. ESR study of Co-doped TiO2 thin films

    Co:TiO2 thin films prepared by reactive co-sputtering deposition were studied by electron spin resonance (ESR) technique. Magnetization measurements showed hysteretic behavior with the coercive field between 55 and 65 Oe and the saturation magnetization at room temperature ranging from 7 (2.2% Co) to 28 emu/cm3 (8.5% Co). ESR measurements at X-band (9.5 GHz) revealed an anomaly in the temperature behavior of the absorption intensity near the temperature at 60 K. This behavior is attributed to an unconventional spin-glass-like behavior, which results from competition of long-range dipole-dipole interaction and anisotropy fields in ferromagnetic Co nanoparticles

  1. ESR Study of elephant tooth enamel from the Kaerlich-Seeufer site in Germany

    Enamel from 6 different positions in a well preserved elephant tooth from the Kaerlich-Seeufer site in Germany has been irradiated up to 32 kGy. The X-band (ν=9.5 GHz) ESR spectra of two subsamples have been decomposed into three real components with Maximum Likelihood Common Factor Analysis (MLCFA). One of these components due to orthorhombic CO-2 radicals is predominant. Dose response curves for the contributions of these MLCFA components and for different heights in the ESR spectra have been obtained and fitted with different models. Depending on the model, the equivalent dose for the preferably used height at g=1.9973, due to CO-2, ranges from 70 to 130 Gy. Due to a very low uranium and thorium content in both enamel and dentine (≤∼ 10 ppb) and to an important external γ-attenuation, the ages fluctuate between 300 and 575 ka

  2. High field ESR study of three dimensional spin frustrated system MgCr2O4

    High field ESR measurements of a single crystal of the spin frustrated spinel compound MgCr2O4 have been performed in the temperature range from 1.7 to 80K in the frequency range from 60 to 370GHz. We found that MgCr2O4 is an easy-plane type antiferromagnet with the hard axis almost along the direction below the Neel temperature TN. In order to obtain more detailed information, we have performed high field ESR measurements in an attempt to align the domains by applying a weak biaxial or uniaxial pressure. These results indicate that the structural phase transition is accompanied by a contraction along one of the directions and the contracted direction becomes the magnetic hard axis below TN. (author)

  3. ESR (electron spin resonance)-determined osmotic behavior of bull spermatozoa

    Du, J.; Kleinhans, F.W.; Spitzer, V.J.; Critser, J.K. (Methodist Hospital, Indianapolis, IN (USA). Dept. of Medical Research); Horstman, L. (Purdue Univ., Lafayette, IN (USA). School of Veterinary Medicine); Mazur, P. (Oak Ridge National Lab., TN (USA))

    1990-01-01

    Our laboratories are pursuing a fundamental approach to the problems of semen cryopreservation. For many cell types (human red cells, yeast, HeLa) it has been demonstrated that there is an optimum cooling rate for cryopreservation. Faster rates allow insufficient time for cell dehydration and result in intracellular ice formation and cell death. It is possible to predict this optimal rate provided that the cell acts as an ideal osmometer and several other cell parameters are known such as the membrane hydraulic conductivity. It is the purpose of this work to examine the osmotic response of bull sperm to sucrose and NaCl utilizing electron spin resonance (ESR) to measure cell volume. For calibration purposes we also measured the ESR response of human red cells (RBC), the osmotic response of which is well documented with other methods. 15 refs., 1 fig.

  4. Study of the influence of grain size on the ESR angular response in alanine radicals

    The simulation of electron paramagnetic resonance (EPR) spectra of radicals potentially due to alanine radiolysis has been done. Combining theoretical spectra in varying proportions allows computing different alanine spectra. The small changes in specific regions of experimental spectra correspond to weak variations in the proportion of radicals. As the study of several parameters, such as ESR angular response of powder or time after irradiation, is not possible in simulated spectra, experimental analyses have been carried out for the ESR angular response dependence on grain size in various combinations, corresponding to an available external surface. The stabilization of the angular response is associated with a spatial reorganization of radicals. It seems that available surface and radical proportions are linked. Predicted values of angular response calculated from pure powders do not correspond to experimental ones. Weak changes in spectra seem to confirm that these variations may be interpreted as a transformation of one radical into another

  5. ESR study of the CF3xxxF radical in irradiated trifluoroacetamide single crystals

    ESR and deuteration studies of x-irradiated trifluroacetamide crystals at 77 0K show that the CF3(A) radical initially formed interacts with a fluorine nucleus on a neighboring molecule, resulting in an additional fluorine doublet of A/sub z/=10 G, A/sub y/0K and is irreversibly replaced by the ESR spectrum of CF3(B) that is stable to 200 0K. Based on an INDO calculation, the formation of CF3(A) occurs when the crystallographic intermolecular FxxxCF3 distance in the parent compound decreases from 3.77 to 2.4 A upon radical formation at 77 0K. Following the formation of CF3(A), the FxxxCF3 distance increases with time or temperature to approximately 3.0 A

  6. Dosimetric properties of watch glass: a potential practical ESR dosemeter for nuclear accidents

    Some essential dosimetric properties of watch glass, such as dose response, signal stability, environmental effects, and background distribution were investigated with ESR techniques. With a special testing method suitable for plate shaped samples and with relatively high dielectrical consumption, a good linear dose response (r = 0.9950) in the range 0-50 Gy and a low detectable threshold of less than 2 Gy were achieved. The irradiation induced signal of g = 2.0082 had a decay of about 20% during the first 24 h after irradiation at room temperature. The speed of decay was slower at lower storage temperatures. By a simple heating process, the original background level of the irradiated samples could be obtained exactly. The above characteristics suggested that watch glass was an appropriate ESR dosimetric material accidental dose evaluation. (author)

  7. Uses of polymer-alanine film/ESR dosimeters in dosimetry of ionizing radiation

    Alanine ESR dosimetry is a reliable method, used in a various fields of ionizing radiation. The polymer-alanine film/ESR dosimeters of 0.3 -0.4 mm thickness were prepared and their dosimetric properties were studied for 60Co γ photons and 3 - 5 MeV electrons in the dose range from 20 Gy to 100 kGy. The results show that under normal conditions the alanine calibration curves are linear in the dose range from 100 Gy to 10kGy. The dose profiles at the electron radiation field were measured with the film alanine dosimeters. The polymer-alanine film dosimeters were used for ion implantation of 400 keV ion implantor. Their dose response and energy dependence were investigated initially. (Author)

  8. ESR study of advanced materials with new parameters frequency and pressure

    Mizoguchi, K

    2000-01-01

    It is well known that electron spin resonance (ESR) is a useful technique to investigate the magnetic properties of electrons in condensed matter. The frequency, as an additional parameter to the temperature, gives us the possibility to study the anisotropic dynamics of charge carriers with spin, even in polycrystalline materials. Furthermore, the pressure provides us a way to discuss how interactions between the electrons and their environments are responsible for the novel physical properties in these advanced materials, such as ferromagnetisms, charge-density waves, superconductivity, and so on. Results obtained by using ESR with these parameters are overviewed. Studies as a function of the frequency are demonstrated, especially for the conductive polymers, polyacetylene, polyaniline, and polypyrrole with various dopants for which single crystals are not available yet. Alkali-electro-sodalite (AES), a kind of zeolite with a regular electron lattice known as an s-electron Mott insulator, and fullerene compo...

  9. ESR and spectral studies of Er3+ ions in soda-lime silicate glass

    Electron spin resonance (ESR), optical absorption spectra and photoluminescence spectra of Er3+ ions in soda-lime silicate glasses doped with different concentrations of Er2O3 have been studied. The glasses of the composition (in mol%) (65-x)SiO2:25Na2O:10CaO:xEr2O3 (where x=0.02, 0.05, 0.1, 0.3, 0.5, 1, 2, 3, 4 and 5) were prepared by the melt quenching method. ESR measurements were carried out at room temperature down to 1.62 K. Absorption spectra were investigated in the UV-VIS-NIR region from 300 to 1800 nm. Photoluminescence spectra were observed in the spectral range 500-800 nm under 514.5 nm argon-ion laser line excitation.

  10. Regeneration of phenolic antioxidants from phenoxyl radicals: An ESR and electrochemical study of antioxidant hierarchy

    Jørgensen, Lars V.; Madsen, Helle L.; Thomsen, Marianne K.; Dragsted, Lars O.; Skibsted, Leif H.

    1999-01-01

    Radicals from the flavonoids quercetin, (+)-catechin, (+/-)-taxifolin and luteolin, and from all-rac-alpha-tocopherol have been generated electrochemically by one-electron oxidation in deaerated dimethylformamide (DMF), and characterised by electron spin resonance spectroscopy (ESR) after spin...... products, were for each antioxidant allowed to react with each of the four other antioxidants, and the progression of reaction followed by ESR after addition of DMPO, and the product solution further analysed by HPLC. All-rac-alpha-tocopherol was found to be most efficient in regenerating each of the other...... based on the reduction potentials determined by cyclic voltammetry under similar conditions (0.93 V for all-rac-alpha-tocopherol, 1.07 V for quercetin, 1.15 V for luteolin, 1.16 V for (+)-catechin and 1.20 V for (+/-)-taxifolin) is compared with the observed over-all regeneration (34% for quercetin, 34...

  11. ESR dating of an ancient goat tooth from Nuoro, Sardinia, Italy

    The dating of fossil teeth of an ancient goat (Nesogoral melonii) using the electron spin resonance (ESR) technique is reported. This animal was found in the fossiliferous site at Orosei (Nuoro, Sardinia, Italy) and was endemic in the region. Molar teeth were cleaned and enamel was completely removed from dentine. Enamel was irradiated with a 60Co gamma source and measured with an ESR spectrometer (X-band) to obtain the signal vs. dose curve and fitted with an exponential function. The archaeological dose obtained by the fitting was 211 ± 34 Gy. Uranium and thorium concentrations were determined by neutron activation analysis. With the software ROSY the age estimates were 195 ± 30 ky for early uptake, 247 ± 40 ky for linear uptake and 243 ± 40 ky for a combination of uptake processes. (authors)

  12. Possible new temperature phase observed in GeCo2O4 spinel by high-field ESR

    High-field ESR measurements of cubic spinel GeCo2O4 single crystals have been performed using the pulsed magnetic field up to 16 T in the temperature range from 300 K to 1.8 K. Dynamical resonance shifts due to antiferromagnetic ordering were observed. New AFMR modes appear below 3 K. High-field ESR measurements reveal complicated phase structures and field-induced magnetic phases below TN, suggesting new temperature field phases.

  13. Correlation between ESR spectra parameters of NO3 radical and symmetry of nitrate-ion in irradiated crystalline matrices

    ESR spectra of NO3 radical in NH4NO3, NaNO3 and KClO4:NO3 matrices with different symmetry of nitrate-ion are studied. The samples were irradiated at 77 and 300 K in RUM-17 X-ray facility. The decisive influence of nitrate-ion initial symmetry on NO3 radical ESR spectrum parameters which is produced under irradiation of different crystalline matrices, containing NO3- is shown

  14. Relationships between ESR-evaluated doses estimated from enamel and activity of radionuclides in bone and teeth of reindeer

    Doses of radiation estimated from ESR analysis of tooth enamel were compared with activities of alpha- and beta-emitters in enamel and in bone tissue of mandibles of 77 reindeer from populations with different levels of radiation contamination. Contribution of the radionuclides incorporated into bone (or bone-seeking radionuclides in food) to ESR-evaluated doses was substantial and the contribution of the radionuclides incorporated into enamel itself proved to be relatively small

  15. ESR of copper and iron complexes with antitumor and cytotoxic properties.

    Antholine, W E; Kalyanaraman, B.; Petering, D H

    1985-01-01

    The relatively few iron and copper metal complexes which have been examined in cells and tissues for their redox properties, radical generation properties, and antitumor activity are discussed for studies which utilized electron spin resonance spectroscopy (ESR). A common property of a number of metal complexes, which include bleomycin, adriamycin, and thiosemicarbazones described in this review, is that they are readily reduced by thiol compounds and oxidized by oxygen or reduced species of ...

  16. ESR of an O/sub 3//sup -/ centre in KCl

    Callens, F.; Matthys, P.; Boesman, E.

    1988-06-20

    By means of ESR an ozonide molecular O/sub 3//sup -/ ion was detected in x-irradiated KCl. The principal values of the G-tensor (2.0032, 2.0182, 2.0118) are in excellent agreement with the values found in other host lattices and with CNDO calculations performed earlier. All measurements were carried out at liquid-helium temperatures.

  17. E layer dominated ionosphere observed by EISCAT/ESR radars during solar minimum

    Cai, Hongtao; Li, Fei; Shen, Ge; Zhan, Weijia; Zhou, Kangjun; McCrea, Ian Willian; Ma, Shuying

    2014-01-01

    According to the study by Mayer and Jakowski (2009), periods of E layer dominated ionosphere (ELDI) are defined as being characterized by vertical electron density profiles having a maximum density at E layer altitudes. In this paper, characteristics of ELDI intervals have been investigated, focusing on their temporal variations, using field-aligned measurements from the EISCAT and ESR radars during the interval 2009–2011. ELDI events were identified using simple but reasona...

  18. Radiation damage in bioapatites: the ESR spectrum of irradiated dental enamel revisited

    We have studied the ESR spectrum of enamel from fossil vertebrate teeth perpendicular = 2.0026 and glongitudinal = 1.9975; and species B, having an orthorhombic symmetry with g1 = 2.0032, g2 = 2.0018 and g3 = 1.9975. Center A is probably located at an OH- site of the hydroxyapatite lattice. Centre B could be a distorted centre A. (author)

  19. Construction of an ESR-STM for Single Molecular Based Magnets anchored at Surfaces

    Messina, Paolo; Sigalotti, Paolo; Lenci, Lorenzo; Mannini, Matteo; Prato, Stefano; Pittana, Paolo; Gatteschi, Dante

    2004-01-01

    Reading and manipulating the spin status of single magnetic molecules is of paramount importance both for applicative and fundamental purposes. The possibility to combine Electron Spin Resonance (ESR) and Scanning Tunnelling Microscopy (STM) has been explored one decade ago. A few experiments have raised the question whether or not an EPR spectrum of single molecule is detachable. Only a few data have been reported in modern surface science literature. To date it has yet to be proven to which...

  20. Core curriculum for medical physicists in radiology. Recommendations from an EFOMP/ESR working group

    Geleijns, Jacob; Breatnach, Éamann; Cantera, Alfonso Calzado; Damilakis, John; Dendy, Philip; Evans, Anthony; Faulkner, Keith; Padovani, Renato; Van Der Putten, Wil; Schad, Lothar; Wirestam, Ronnie; Eudaldo, Teresa; ,

    2012-01-01

    Some years ago it was decided that a European curriculum should be developed for medical physicists professionally engaged in the support of clinical diagnostic imaging departments. With this in mind, EFOMP (European Federation of Organisations for Medical Physics) in association with ESR (European Society of Radiology) nominated an expert working group. This curriculum is now to hand. The curriculum is intended to promote best patient care in radiology departments through the harmonization o...

  1. Submillimeter wave ESR study on triangular lattice antiferromagnet CuFeO2

    The first submillimeter wave ESR on triangular lattice antiferromagnet, CuFeO2 has been performed in frequencies up to 762 GHz. The changes of AFMR modes were observed for H parallel c, corresponding to the metamagnetic transition which occurred below TN2. In a phase between TN1 and TN2, we observed an easy-plane type AFMR mode which could not explain a partially disordered model suggested by neutron diffraction experiments

  2. Data of ESR dosimetry study of population in the vicinity of Semipalatinsk Nuclear Test Site

    Zhumadilov, Kassym; Ivannikov, Alexander; Stepanenko, Valeriy; Zharlyganova, Dinara; Zhumadilov, Zhaxybay; Apsalikov, Kazbek; Toyoda, Shin; Zhumadilova, Anara; Endo, Satoru; Tanaka, Kenichi; Miyazawa, Chuzou; Yamamoto, Masayoshi; Okamoto, Tetsuji; Hoshi, Masaharu

    2012-01-01

    The method of electron spin resonance (ESR) dosimetry was used to human tooth enamel to obtain individual absorbed doses of population of settlements in the vicinity of the Semipalatinsk Nuclear Test Site (SNTS), Kazakhstan. The distances between investigated settlements and Ground Zero (SNTS) are in the range 70 - 200 km from SNTS. Most of settlements (Dolon, Mostik, Bodene) are located near the central axis of radioactive fallout trace from the most contaminating surface nuclear test, which...

  3. ESR dosimetry study of population in the vicinity of the Semipalatinsk Nuclear Test Site

    Zhumadilov, Kassym; Ivannikov, Alexander; Stepanenko, Valeriy; Zharlyganova, Dinara; Toyoda, Shin; Zhumadilov, Zhaxybay; Hoshi, Masaharu

    2013-01-01

    A tooth enamel electron spin resonance (ESR) dosimetry study was carried out with the purpose of obtaining the individual absorbed radiation doses of population from settlements in the Semipalatinsk region of Kazakhstan, which was exposed to radioactive fallout traces from nuclear explosions in the Semipalatinsk Nuclear Test Site and Lop Nor test base, China. Most of the settlements are located near the central axis of radioactive fallout trace from the most contaminating surface nuclear test...

  4. Silyloxyamines as Sources of Silyl Radicals: ESR Spin Trapping, Laser Flash Photolysis Investigation and Photopolymerization Ability

    Lalevee, Jacques

    2010-01-01

    Abstract Two original silyloxyamines derived from 8-(pentamethyldisilyloxy)-julolidine and diethyl 3-(pentamethyldisilyloxy)-aniline are proposed as new sources of silyl radicals. The decomposition mechanism, the excited state processes and the radical generation are explored by steady state photolysis, laser flash photolysis, ESR and MO calculations. The Si-Si bond cleavage is clearly demonstrated. The formation of a radical cation on the amine moiety is also observed. Moreover, t...

  5. Irradiation detection in spices applying PSL, ESR, or iodometric starch analysis

    Irradiation detection in spices is possible applying a combination of various methods. The method of first choice is PSL, which yields a quick result for a great variety of samples and does not require specific sample preparation. When there is need for verification of PSL test results, ESR, viscosity measurements, determination of starch contents or hydrocarbons in spices containing lipids are suitable tests. (orig./CB)

  6. ESR statement on radiation protection: globalisation, personalised medicine and safety (the GPS approach)

    ,

    2013-01-01

    Abstract In keeping with its responsibility for the radiation protection of patients undergoing radiological examinations and procedures, as well as of staff who are getting exposed, and with due regard to requirements under European Directives, the European Society of Radiology (ESR) issues this statement. It provides a holistic approach, termed as Globalisation (indicating all the steps and involving all stakeholders), Personalisation (referring to patient-centric) and Safety—thus called GP...

  7. The watch glass used for ESR dosimetric material in nuclear accident

    Electron spin resonance technique was used to investigate the ESR characteristic of watch glass irradiated with γ-ray. The result showed that signal intensity has a linear relation with irradiation dose in range of 0-50 Gy, the lower limit of detectable dose is below 2 Gy. It suggests that watch glass can be a kind of applicative material for nuclear accident dose evaluation

  8. Dosimetry for radiation processing of wire insulations by using the alanine/ESR system

    The wire insulation can be simulated by an alanine-based dosimeter, i.e. by a polymer containing L-α-alanine. If this system is properly calibrated against a reliable reference dosimeter, it can be used to determine the absorbed dose in the wire insulation, irradiated on an industrial line for electron-beam crosslinking of wire insulations. The evaluation is achieved by ESR spectroscopy. (author) 13 refs.; 3 figs

  9. The ESR/alanine dosimeter - power dependence of the X-band spectrum

    Arber, J.M.; Sharpe, P.H.G. (National Physical Lab., Teddington (UK)); Joly, H.A.; Morton, J.R.; Preston, K.F. (National Research Council, Ottawa (Canada). Steacie Inst. for Molecular Sciences)

    1991-01-01

    Satellite lines which accompany the central feature of the X-band ESR spectrum of {alpha}-alanine dosimeters are shown to be due to forbidden ''spin-flip'' transitions associated with methyl protons on nearby molecules. At microwave powers in excess of 1 mW the satellites increase in intensity relative to the central feature, and thus measurements at higher microwave powers must be based on experimentally determined calibration curves at the appropriate power levels. (author).

  10. ESR Studies and Dating of Egyptian Gypsum at Ras Mala'ab, Sinai, Egypt

    A gypsum sample from the famous gypsum-anhydrite evaporitic deposit composing the Ras Mala'ab Formation, Upper Miocene, occurring at Ras Mala'ab, on the east coast of the Gulf of Suez, was subjected to (ESR) dosimetric studies. Also, (ESR) was used to date the formation or most recent recrystallization of that gypsum. The gypsum derivative (ESR) spectrum is characterized by the large broad Fe2+ signal (g=2.50) and HF-sixtet Mn2+ signals. Only the characteristic gypsum signal (G l, g=2.0040) was detected between the third and fourth lines of the HF-Mn2+ which is attributed to the electron-center SO3-. This signal was sensitive to artificial γ-irradiation and showed significant enhancement using a γ-dose of 550 Gy. Also, the signal was very stable up to 400 oC. The gypsum sample with a total dose (TD) of 1500 Gy, determined graphically by extrapolating the linear relationship between defect concentration and the artificial γ-doses for (G l, g=2.0040) and an annual dose (D) due to cosmic rays (0.3 mGy), yielded an age of 5.00 Ma. This could mean the age of formation or latest recrystallization of this gypsum deposit. The geologic age assignment of the Ras Mala'ab Group including the evaporitic gypsum unit, is Middle to Late Miocene. It is directly overlain by the Pliocene elastics at the locality of Ras Mala'ab. This might suggest that these evaporitic gypsum facies represent the top of the Miocene in the Gulf of Suez area, since the Miocene-Pliocene boundary is now put at 5.00-5.50 Ma ago. Therefore, the ESR age of the Ras Mala'ab gypsum is consistent with the geologic age assignment

  11. Epistasis Between Polymorphisms in COMT, ESR1, and GCH1 Influences COMT Enzyme Activity and Pain

    Smith, Shad B.; Reenilä, Ilkka; Männistö, Pekka T.; Slade, Gary D.; Maixner, William; Diatchenko, Luda; Nackley, Andrea G

    2014-01-01

    Abnormalities in the enzymatic activity of catechol-O-methyltransferase (COMT) contribute to chronic pain conditions, such as temporomandibular disorders (TMD). Thus, we sought to determine the effects of polymorphisms in COMT and functionally-related pain genes in the COMT pathway (estrogen receptor 1: ESR1, guanosine-5-triphosphate cyclohydrolase 1: GCH1, methylenetetrahydrofolate reductase: MTHFR) on COMT enzymatic activity, musculoskeletal pain, and pain-related intermediate phenotypes am...

  12. Measuring brain tissue oxygenation under oxidative stress by ESR/MR dual imaging system

    The in vivo measurement of oxygen in tissues is of great interest because of oxygen's fundamental role in life. Many methods have been developed for such measurement, but all have been limited, especially with regard to repeated measurement, degree of invasiveness, and sensitivity. We describe electron spin resonance (ESR) oximetry with paramagnetic oxygen-sensing probe for in vivo measurement of oxygen in brain tissues by homemade ESR/MR dual imaging spectroscopy. Lithium 5, 9, 14, 18, 23, 27, 32, 36-octan-butoxy-2, 3-naphthalocyanine (LiNc-BuO) radical was employed as the solid oxygen-sensing probe, and we confirmed its ability to report partial pressure of oxygen (pO2) in brain tissues of live animals under normal and pathological conditions for more than a month. pO2 measurements could also be made repeatedly on the same animal and at the same location. The implantation site of LiNc-BuO in examined rats was verified by 0.5T magnetic resonance (MR) imaging. Septic-shock rats were used to monitor tissue oxygenation during pathological state. A decline in pO2 levels from severe hypotension during sepsis was detected, and generation of nitric oxide (NO) in brain tissues was confirmed by NO spin trapping. ESR oximetry using oxygen-sensing probe and NO spin-trapping can be used to monitor pO2 change and NO production simultaneously and repeatedly at the same site in examined animals. (author)

  13. An FTIR and ESR study of iron doped calcium borophosphate glass-ceramics

    Karabulut, M.; Popa, A.; Borodi, G.; Stefan, R.

    2015-12-01

    A series of glasses in the xFe2O3-(100-x) [42B2O3-24CaO-34P2O5] system has been prepared for x = 0-10. Structure of as casted glasses and their heat treated counterparts have been studied by X-ray diffraction, infrared and electron spin resonance spectroscopies. Amorphous nature of all of the compositions studied is confirmed by the XRPD spectra. After the heat treatment, besides the main BPO4 phase, CaBPO5 and Ca(PO3) crystalline phases were identified in the iron free glass while B0.57Fe0.43PO4 phase was also observed in the XRD pattern of iron containing samples. FTIR spectra indicate changes in the glass network upon iron addition. X-band ESR spectra exhibits resonance signals at g ∼ 2.0 and g ∼ 4.3 for all analyzed samples. A supplementary line centered at g ∼ 6 appears after the thermal treatment. The nature of ESR absorption signals and influence of iron content on the evolution of ESR parameters are discussed.

  14. Dielectric resonator-based resonant structure for sensitive ESR measurements at high-hydrostatic pressures.

    Sienkiewicz, Andrzej; Vileno, Bertrand; Garaj, Slaven; Jaworski, Marek; Forró, László

    2005-12-01

    We present a newly developed microwave probe head that accommodates a gasketed sapphire anvil cell (SAC) for performing sensitive electron spin resonance (ESR) measurements under high-hydrostatic pressures. The system was designed around commercially available dielectric resonators (DRs) having the dielectric permittivity of approximately 30. The microwave resonant structure operates in a wide-stretched double-stacked geometry and resonates in the lowest cylindrical quasi TE(011) mode around 9.2 GHz. The most vital parts of the probe's microwave heart were made of plastic materials, thus making the resonant structure transparent to magnetic field modulation at 100 kHz. The overall ESR sensitivity of the probe was demonstrated for a small speck of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) positioned in the gasket of the SAC, using water as the pressure-transmitting medium. The system was also used for studying pressure-induced changes in spin-relaxation mechanisms of a quasi-1D-conducting polymer, K(1)C(60). For small samples located in the sample hole of the gasket the probe reveals sensitivity that is only approximately 3 times less than that yielded by regular ESR cavities. PMID:16168687

  15. ESR Study of the polyvinyl alcohol gamma-ray induced free-radicals

    This work reports the findings of the molecular weight effect on the electron spin resonance saturation curve of the gamma-ray irradiated polyvinyl alcohol, G-RIPVA. It has been noted that Pva of a lower molecular weight, between 13,000-23,000, show some noticeable differences in the electron spin resonance, ESR, response as a function of the gamma-ray dose in the 1-100 k Gy range than the one reported in the literature with molecular weight of 108,000. Results show a linear response in the log-log plot of the dose vs ESR signal intensity for samples based on G-RIPVA of the lower molecular weight as contrasted with the non-linear ESR response of G-RIPVA of higher molecular weight in the above named dose range. Such a result has been assumed to arise from the shorter molecular chains for the case of the lower molecular weight samples making this to increase the production of Pva free radicals with respect to the absorbed studied doses. Also, a discussion on the nature and stability of the Pva free radicals will be given. (Author)

  16. The relevance of parametric U-uptake models in ESR age calculations

    In the ESR dating three basic parametric U-uptake models have been applied for dating teeth: early U-uptake (EU: closed system), linear U-uptake (LU) and recent U-uptake (RU, it is assumed that the dose rate contribution of U in the dental tissues is zero). In many ESR dating publications it is still assumed that samples comply with one or the other parametric U-uptake model calculation or that their correct age lies somewhere between EU and LU. Observations of the spatial distribution of uranium in dental tissues show that it is difficult to predict any relationships between the relative uptake in the dental tissues. Combined U-series/ESR age estimates can give insights into the actual U-uptake. An evaluation of published data shows that for cave sites, a significant number of results fall outside the EU and LU bracket, while for open air sites, the majority of data are outside this bracket, particularly showing greatly delayed U-uptake. This may be due to changes in the hydrological system, leading to erosion which exposes the open air site. U-leaching has also been observed on samples from open air sites, in which case any reasonable age calculation is impossible.

  17. Determination of isodose curves in Radiotherapy using an Alanine/ESR dosemeter

    It was studied the possible use of an Alanine/ESR dosemeter in the isodose curves mapping in normal treatments of Radiotherapy. It was manufactured a lot of 150 dosemeters with base in a mixture of D-L Alanine dust (80 %) and paraffin (20 %). Each dosemeter has 4.7 mm diameter and 12 mm length. A group of 100 dosemeters of the lot were arranged inside 50 holes of the slice 25 of the phantom Rando Man. The phantom irradiation was realized in two opposed projections (AP and PA) in Co-60 equipment. A group of 15 dosemeters was take of the same lot for obtaining the calibration curve in a 1-20 Gy range. After irradiation the signal of each dosemeter was measured in an ESR spectrometer operating in the X-band (∼ 9.5 GHz) and the wideness of Alanine ESR spectra central line was correlated with the radiation dose. The wideness dose calibration curve resulted linear with a correlation coefficient 0.9996. The isodose curves obtained show a profile enough similar at comparing with the theoretical curves. (Author)

  18. ESR signal in different cuts of irradiated chicken, pork and beef

    Electron spin resonance (ESR) spectroscopy was used to detect irradiated meat containing bones (chicken, pork and beef), to investigate the effect of irradiation dose on the ESR signal intensity and to identify the stability of radicals under 9 weeks of storage. Chicken, pork and beef were irradiated with doses 0, 1, 3, 5 and 7 kGy at room temperature using a co-60 irradiator. Bones were pieced and dried, which were placed in a quartz tube within an electron paramagnetic resonance (EPR) spectrometer resonator cavity. The irradiated bone presented an asymmetric absorption in shape, different from that of a non-irradiated one. The signal intensity of smaller animals are lower than larger species. Variation was observed between samples of the same species depending on the calcification status f the bone. Moreover different irradiation doses produced different signal areas that make possible to estimate the absorbed dose of treated meat. The ESR signal stability after irradiation was stable in even after a 9 week storage at room temperature. (author)

  19. Analysis of parameters that influence the amplitude of the ESR/alanine signal after irradiation

    Dolo, J.M. [BNM-Laboratoire National Henri Becquerel, CEA-Saclay, DIMRI/LNHB, 91191 Gif-sur-Yvette cedex (France)]. E-mail: jean-michel.dolo@cea.fr; Feaugas, V. [BNM-Laboratoire National Henri Becquerel, CEA-Saclay, DIMRI/LNHB, 91191 Gif-sur-Yvette cedex (France)

    2005-02-01

    When ESR/alanine dosimetry is used for comparison, the time elapsed between irradiation and measurement is critical. Several publications have already mentioned the need for monitoring some of the parameters before, during and after irradiation for accurate normalization of ESR measurements. Nevertheless, neither classification nor coupling effects have yet been mentioned. By application of an experimental design approach, some parameters such as temperature and humidity during storage, before and after irradiation, have been studied. Results are given about the way the signal tends to evolve, ranking the parameters according to their influence and the effects of parameter coupling. A comparison with a conventional approach (study of one parameter at a time) is made. It is proposed to use a normalized ESR measurement that better accounts for the chemical aspect. A better fit of the results (amplitude versus time) is observed when amplitude is corrected taking into account the water content of the dosimeter for a given relative humidity of the surrounding atmosphere during storage.

  20. Analysis of parameters that influence the amplitude of the ESR/alanine signal after irradiation.

    Dolo, J M; Feaugas, V

    2005-02-01

    When ESR/alanine dosimetry is used for comparison, the time elapsed between irradiation and measurement is critical. Several publications have already mentioned the need for monitoring some of the parameters before, during and after irradiation for accurate normalization of ESR measurements. Nevertheless, neither classification nor coupling effects have yet been mentioned. By application of an experimental design approach, some parameters such as temperature and humidity during storage, before and after irradiation, have been studied. Results are given about the way the signal tends to evolve, ranking the parameters according to their influence and the effects of parameter coupling. A comparison with a conventional approach (study of one parameter at a time) is made. It is proposed to use a normalized ESR measurement that better accounts for the chemical aspect. A better fit of the results (amplitude versus time) is observed when amplitude is corrected taking into account the water content of the dosimeter for a given relative humidity of the surrounding atmosphere during storage. PMID:15607461

  1. Analysis of parameters that influence the amplitude of the ESR/alanine signal after irradiation

    When ESR/alanine dosimetry is used for comparison, the time elapsed between irradiation and measurement is critical. Several publications have already mentioned the need for monitoring some of the parameters before, during and after irradiation for accurate normalization of ESR measurements. Nevertheless, neither classification nor coupling effects have yet been mentioned. By application of an experimental design approach, some parameters such as temperature and humidity during storage, before and after irradiation, have been studied. Results are given about the way the signal tends to evolve, ranking the parameters according to their influence and the effects of parameter coupling. A comparison with a conventional approach (study of one parameter at a time) is made. It is proposed to use a normalized ESR measurement that better accounts for the chemical aspect. A better fit of the results (amplitude versus time) is observed when amplitude is corrected taking into account the water content of the dosimeter for a given relative humidity of the surrounding atmosphere during storage

  2. Detection and original dose assessment of egg powders subjected to gamma irradiation by using ESR technique

    ESR (electron spin resonance) techniques were applied for detection and original dose estimation to radiation-processed egg powders. The un-irradiated (control) egg powders showed a single resonance line centered at g=2.0086±0.0005, 2.0081±0.0005, 2.0082±0.0005 (native signal) for yolk, white and whole egg, respectively. Irradiation induced at least one additional intense singlet overlapping to the control signal and caused a significant increase in signal intensity without any changes in spectral patterns. Responses of egg powders to different gamma radiation doses in the range 0–10 kGy were examined. The stability of the radiation-induced ESR signal of irradiated egg powders were investigated over a storage period of about 5 months. Additive reirradiation of the egg powders produces a reproducible dose response function, which can be used to assess the initial dose by back-extrapolation. The additive dose method gives an estimation of the original dose within ±12% at the end of the 720 h storage period. - Highlights: • This is the first study on original gamma dose estimation of egg powders using ESR technique. • Dose additive can be used for estimation of the absorbed dose in powder eggs. • The original gamma dose determined with ±12% error at the end of 720 h storage periods. • Powder egg white has good radical yield or radiation sensitivities

  3. ESR analysis of irradiated red peppers and commercial red peppers in Japan

    ESR analysis of γ-ray irradiated and being treated with different processing red pepper was studied. All the red peppers were commercial expect irradiated one. Processing treatment of red pepper was sun drying, mechanical processing (heating sterilization and powdering treatment). All the samples were weighted and analyzed. The ESR spectrum of the red pepper is composed of a singlet at g=2.00. This signal was originated from organic free radical. It is suggested the effect of heating treatment on the radical formation is not so large and powdering treatment will promote the radical formation of red pepper. ESR singlet signal of the irradiated red pepper showed the large signal intensity and the dose-dependence. The singlet signal intensity of irradiated powder sample showed the almost same value as compared with that of the powder sample with heating treatment. Relaxation times (T1 and T2) of the singlet signal were calculated. The relaxation behavior and relaxation times of the irradiated sample were different from that of the non-irradiated sample. The value of T1, the spin lattice relaxation time, of irradiated sample was increased and T2, the spin-spin relaxation time, of irradiated sample was decreased. We concluded that the radical formation of the red pepper is mainly depended on the powdering treatment and irradiation. (author)

  4. In vivo dose evaluation during gynaecological radiotherapy using L-alanine/ESR dosimetry

    The dose delivered by in vivo 3-D external beam radiation therapy (EBRT) was verified with L-alanine/electron spin resonance (ESR) dosimetry for patients diagnosed with gynaecological cancer. Measurements were performed with an X-band ESR spectrometer. Dosemeters were positioned inside the vaginal cavity with the assistance of an apparatus specially designed for this study. Previous phantom studies were performed using the same conditions as in the in vivo treatment. Four patients participated in this study during 20-irradiation sessions, giving 220 dosemeters to be analysed. The doses were determined with the treatment planning system, providing dose confirmation. The phantom study resulted in a deviation between -2.5 and 2.1 %, and for the in vivo study a deviation between -9.2 and 14.2 % was observed. In all cases, the use of alanine with ESR was effective for dose assessment, yielding results consistent with the values set forth in the International Commission on Radiation Units and Measurements (ICRU) reports. (authors)

  5. In vivo dose evaluation during gynaecological radiotherapy using L-alanine/ESR dosimetry.

    Rech, Amanda Burg; Barbi, Gustavo Lazzaro; Ventura, Luiz Henrique Almeida; Guimarães, Flavio Silva; Oliveira, Harley Francisco; Baffa, Oswaldo

    2014-06-01

    The dose delivered by in vivo 3-D external beam radiation therapy (EBRT) was verified with L-alanine/electron spin resonance (ESR) dosimetry for patients diagnosed with gynaecological cancer. Measurements were performed with an X-band ESR spectrometer. Dosemeters were positioned inside the vaginal cavity with the assistance of an apparatus specially designed for this study. Previous phantom studies were performed using the same conditions as in the in vivo treatment. Four patients participated in this study during 20-irradiation sessions, giving 220 dosemeters to be analysed. The doses were determined with the treatment planning system, providing dose confirmation. The phantom study resulted in a deviation between -2.5 and 2.1 %, and for the in vivo study a deviation between -9.2 and 14.2 % was observed. In all cases, the use of alanine with ESR was effective for dose assessment, yielding results consistent with the values set forth in the International Commission on Radiation Units and Measurements (ICRU) reports. PMID:24751984

  6. ESR (Electronic Spin Resonance Spectroscopy) study of irradiated paper for biomedical material wrapping

    Ionising radiation treatments are used for sterilization, microbiological decontamination, disinfection, insect disinfestation and food preservation. This ionising radiation generates free radicals (FR) in matter, which can be detected by Electronic Spin Resonance Spectroscopy (ESR). For this work it had analysed different kind of irradiated package papers of syringes, surgical gloves and dressings by ESR. These were irradiated with doses between 20 and 35 kGy of gamma radiation (Cobalt 60). The processed samples were measured in a Bruker ECS 106 spectrometer. The obtained results were: 1-) The irritated samples showed a central peak and two satellites induced by the applied radiation; 2-) The non-irradiated samples did not show the characteristic satellite peaks of the irritated ones; 3-) A linear relationship between the signal heights per unit mass and the applied doses was found; and 4-) The signals were highly stable, with half-time values between 240 and 370 days for 20 and 30 kGy, permitting more than one year of monitoring proceedings. In conclusion, the ESR allows the detection, quantification and time monitoring processes of this kind of irradiated materials. (author)

  7. Effect of radiation on solid paracetamol: ESR identification and dosimetric features of gamma-irradiated paracetamol

    Polat, M.; Korkmaz, M.

    2006-01-01

    In the present work, electron spin resonance (ESR) identification of gamma-irradiated paracetamol and its potential use as a normal and/or accidental dosimetric material were investigated in the dose range of 2.5-25 kGy. Both unirradiated paracetamol and mechanically ground vermidon samples exhibited a weak single resonance line at g = 2.0049 +/- 0.0006 and had Delta H-pp = 0.6 +/- 0.02 mT. Gamma irradiation produced an increase in signal intensity with a small hyperfine splitting in both paracetamol and vermidon and many weak resonance lines on both sides of a central line in the case of vermidon. Dose-response curves associated with central line of paracetamol and vermidon were found to follow polynomial and linear function, respectively. Simulation calculations based on the room temperature ESR intensity data of the paracetamol sample irradiated at 10 kGy were performed to determine the structure and spectral parameters of the radiation-induced radical species involved in the formation of the experimental ESR spectrum of paracetamol.

  8. Preliminary results of combined ESR/U-series dating of fossil teeth from Longgupo cave, China

    Longgupo Cave site, located in Wushan County, Chongqing, China has attracted continuous attention since its discovery of hominid remains in association with late Pliocene-early Pleistocene fauna and numerous lithic artefacts. In 2003-2006, new excavation was carried out on this site, allowing the description of a detailed stratigraphy of the highly complex cave in-fillings and the sampling of teeth for combined ESR/U-series analyses. Here we report preliminary dating results of seven herbivorous fossil teeth from different archaeological layers of the lowest geological unit (C III). Uranium-series analyses indicate that no obvious uranium leaching has occurred and all the teeth (except one) underwent a very recent uranium uptake history. The obtained US-ESR results show that the age of six teeth are basically consistent, between similar to 1.4 and 1.8 Ma. At the same time, we observed an inverse correlation of two samples with the stratigraphic sequence. This could be caused by the distinct uranium uptake history of one sample, high uranium content in the enamel for another or bad estimation of external dose rate. Due to the complexity of the stratigraphic sequence, supplementary in situ gamma dose rate measurement should be performed for all the samples during the following excavations in order to confirm this preliminary ESR/U-series chronology. (authors)

  9. TL and ESR based identification of gamma-irradiated frozen fish using different hydrolysis techniques

    Frozen fish fillets (walleye Pollack and Japanese Spanish mackerel) were selected as samples for irradiation (0–10 kGy) detection trials using different hydrolysis methods. Photostimulated luminescence (PSL)-based screening analysis for gamma-irradiated frozen fillets showed low sensitivity due to limited silicate mineral contents on the samples. Same limitations were found in the thermoluminescence (TL) analysis on mineral samples isolated by density separation method. However, acid (HCl) and alkali (KOH) hydrolysis methods were effective in getting enough minerals to carry out TL analysis, which was reconfirmed through the normalization step by calculating the TL ratios (TL1/TL2). For improved electron spin resonance (ESR) analysis, alkali and enzyme (alcalase) hydrolysis methods were compared in separating minute-bone fractions. The enzymatic method provided more clear radiation-specific hydroxyapatite radicals than that of the alkaline method. Different hydrolysis methods could extend the application of TL and ESR techniques in identifying the irradiation history of frozen fish fillets. - Highlights: • Irradiation has potential to improve hygienic quality of raw and processed seafood. • Detection of irradiated food is important to enforce the applied regulations. • Different techniques were compared to separate silicate minerals from frozen fish. • Limitations were observed in TL analysis on minerals isolated by density separation. • Hydrolysis methods provided more clear identification using TL and ESR techniques

  10. The combined genotypes effe- ct of ESR and FSHb genes on litter size traits in five differe- nt pig breeds

    2001-01-01

    Estrogen receptor (ESR) and Follicular-stimula- ting hormone beta subunit (FSHb) genes were chosen as candidates to determine whether they control litter size and some other reproductive traits in swine. 269 sows from five different pig breeds were genotyped by an established PCR- RFLPs protocol at both ESR and FSHb loci. The effects of both ESR and FSHb on pig reproductive traits, including total number born (TNB) and number born alive (NBA), are analyzed by SAS software (version 6.12). These computation results demonstrated that both ESR locus and FSHb locus are the major genes influencing litter size in pigs. The sows of BBBB combined genotype of ESR and FSHb loci generally produce 1.85-3.01 TNB and 2.0-3.0 NBA more than those of ABAA combined genotype. The notable effect of ESR locus and FSHb locus on litter size of pigs have made it possible to improve the pig reproduction by Marker-assisted selection (MAS). Moreover, introgression of the beneficial alleles into commercial pig breeding lines, in which the alleles were not present, will improve greatly the economically imp- ortant reproductive traits and efficiency of pig production.

  11. Acoustic emission source modeling

    Hora, Petr; Červená, Olga

    2010-01-01

    Roč. 4, č. 1 (2010), s. 25-36. ISSN 1802-680X R&D Projects: GA ČR GA101/09/1630 Institutional research plan: CEZ:AV0Z20760514 Keywords : acoustic emission source * wave propagation * FEM Subject RIV: BI - Acoustics

  12. Acoustic Neuroma Educational Video

    Full Text Available ... Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself Post-treatment Post-treatment ... Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself Post-treatment Post-treatment ...

  13. Ocean acoustic hurricane classification.

    Wilson, Joshua D; Makris, Nicholas C

    2006-01-01

    Theoretical and empirical evidence are combined to show that underwater acoustic sensing techniques may be valuable for measuring the wind speed and determining the destructive power of a hurricane. This is done by first developing a model for the acoustic intensity and mutual intensity in an ocean waveguide due to a hurricane and then determining the relationship between local wind speed and underwater acoustic intensity. From this it is shown that it should be feasible to accurately measure the local wind speed and classify the destructive power of a hurricane if its eye wall passes directly over a single underwater acoustic sensor. The potential advantages and disadvantages of the proposed acoustic method are weighed against those of currently employed techniques. PMID:16454274

  14. Cochlear bionic acoustic metamaterials

    Ma, Fuyin; Wu, Jiu Hui; Huang, Meng; Fu, Gang; Bai, Changan

    2014-11-01

    A design of bionic acoustic metamaterial and acoustic functional devices was proposed by employing the mammalian cochlear as a prototype. First, combined with the experimental data in previous literatures, it is pointed out that the cochlear hair cells and stereocilia cluster are a kind of natural biological acoustic metamaterials with the negative stiffness characteristics. Then, to design the acoustic functional devices conveniently in engineering application, a simplified parametric helical structure was proposed to replace actual irregular cochlea for bionic design, and based on the computational results of such a bionic parametric helical structure, it is suggested that the overall cochlear is a local resonant system with the negative dynamic effective mass characteristics. There are many potential applications in the bandboard energy recovery device, cochlear implant, and acoustic black hole.

  15. Computational Ocean Acoustics

    Jensen, Finn B; Porter, Michael B; Schmidt, Henrik

    2011-01-01

    Since the mid-1970s, the computer has played an increasingly pivotal role in the field of ocean acoustics. Faster and less expensive than actual ocean experiments, and capable of accommodating the full complexity of the acoustic problem, numerical models are now standard research tools in ocean laboratories. The progress made in computational ocean acoustics over the last thirty years is summed up in this authoritative and innovatively illustrated new text. Written by some of the field's pioneers, all Fellows of the Acoustical Society of America, Computational Ocean Acoustics presents the latest numerical techniques for solving the wave equation in heterogeneous fluid–solid media. The authors discuss various computational schemes in detail, emphasizing the importance of theoretical foundations that lead directly to numerical implementations for real ocean environments. To further clarify the presentation, the fundamental propagation features of the techniques are illustrated in color. Computational Ocean A...

  16. Acoustic Signals and Systems

    The Handbook of Signal Processing in Acoustics will compile the techniques and applications of signal processing as they are used in the many varied areas of Acoustics. The Handbook will emphasize the interdisciplinary nature of signal processing in acoustics. Each Section of the Handbook will...... present topics on signal processing which are important in a specific area of acoustics. These will be of interest to specialists in these areas because they will be presented from their technical perspective, rather than a generic engineering approach to signal processing. Non-specialists, or specialists...... from different areas, will find the self-contained chapters accessible and will be interested in the similarities and differences between the approaches and techniques used in different areas of acoustics....

  17. ESR based detection method for irradiated dry fish, tomato soup powder and sweet-meats

    Full text: Radiation Processing is increasingly being accepted as one of the most effective and economic method to treat agricultural and horticultural commodities for hygienization and disinfestation purposes and also in overcoming strict quarantine barriers in international trade. At present there is a growing concern about the presence of insecticides and pesticides and their residues in various foods, we consume. In view of this, irradiation, being a physical and cold process, emerges as the best bet towards having an uninterrupted supply of safe and quality food. The process has been endorsed as safe by several international and national bodies. A suitable detection method is however required to meet the basic requirements of consumers and law enforcement authorities, regulating the trade. Dried, sliced Pollack and File fishes were subjected to radiation dose of 4 kGy for elimination of coliforms and for improvement in quality standards during storage. Bones separated served as sample source for ESR based detection method of the radiation treatment. Bones with hard crystalline matrix served as trap for free radicals and facilitated evolution of an ESR based detection method. It showed a linear dose response curve at γ=2.0037, whereas, those from non-irradiated fish fillets failed to show any ESR signal. Re-irradiation helped in calculation of dose delivered to dried fishes. Sachets -containing tomato soup ingredients, including sugars exposed to 0.25 to 2 kGy gamma radiation doses for hygienization and quarantine purposes were used in the experiments. In-pack sugar crystals served as free radicals trap for ESR based detection method for radiation hygienized tomato soup powder. Similarly, it was observed that radiation hygienization of sugar bearing sweet-meats, like Peda (an evaporated milk preparation), Petha (a sugar syrup soaked vegetable preparation) and dry fruits like raisins could be detected using ESR. Suitable methodology was developed to detect

  18. Irradiation-induced defects in silica glass studied by positron annihilation, ESR and optical absorption

    Fused and Synthetic silica glass samples were irradiated with fast neutrons up to a dose of 8.6 x 1018 n/cm2. Before and after irradiation, positron lifetime, angular correlation of positron annihilation radiation (ACAR), electron spin resonance (ESR) and optical absorption with photon energy ranging from 2 to 6.6 eV were measured. Positron lifetime spectra were decomposed into three components with the time constant τi (i=1,2,3) and their relative intensities Ii (I1+I2+I3=1). After irradiation, two kinds of defects which trap positrons were suggested by positron lifetime spectra: the type-1 defect gives a positron lifetime of about 0.3 ns for the τ1 component, while the type 2 gives about 0.5 ns of the τ2 lifetime. In ESR spectra of the irradiated samples, three kinds of paramagnetic defects were observed.: E' centers, peroxy radicals (POR) and non-bridging oxygen hole center (NBOHC). In optical absorption spectra, absorption bands around 4.8, 5.0, 5.4 and 5.8 eV were resolved. Photo-bleaching effects of ultraviolet rays with energy of 4.9 eV on E' center and POR in ESR spectra and on the 5.0, 5.4 and 5.8 absorption bands were observed, but no change was detected in the 4.8 band. No photo-bleaching effect, however, was obtained in the positron lifetime spectra. Positron lifetime and ESR measurements were also made after post-irradiation isochronal annealing. Detailed results from the photo-bleaching and the annealing experiments strongly suggest that the type 2 defect is not detected by ESR and hence a diamagnetic defect, while that the type 1 defect is a paramagnetic defect, possibly NBOHC. Both kinds of the defects, however, gave nearly the same ACAR momentum distribution, which reveals that the two kind defects are associated with the same valence electrons of oxygen related centers. (author)

  19. Flat acoustic lens by acoustic grating with curled slits

    We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry–Perot resonance. - Highlights: • Expression of transmission coefficient of an acoustic grating with curled slits. • Non-dispersive and tunable effective medium parameters for the acoustic grating. • A flat acoustic focusing lens with gradient index by using the acoustic grating

  20. From Architectural Acoustics to Acoustical Architecture Using Computer Simulation

    Schmidt, Anne Marie Due; KIRKEGAARD, Poul Henning

    2005-01-01

    Architectural acoustics design has in the past been based on simple design rules. However, with a growing complexity in architectural acoustics and the emergence of room acoustic simulation programmes with considerable potential, it is now possible to subjectively analyse and evaluate acoustic properties prior to the actual construction of a building. With the right tools applied, acoustic design can become an integral part of the architectural design process. The aim of this paper is to inve...

  1. Underwater Applications of Acoustical Holography

    P. C. Mehta

    1984-01-01

    Full Text Available The paper describes the basic technique of acoustical holography. Requirements for recording the acoustical hologram are discussed with its ability for underwater imaging in view. Some practical systems for short-range and medium-range imaging are described. The advantages of acoustical holography over optical imaging, acoustical imaging and sonars are outlined.

  2. Predicting Acoustics in Class Rooms

    Christensen, Claus Lynge; Rindel, Jens Holger

    2005-01-01

    Typical class rooms have fairly simple geometries, even so room acoustics in this type of room is difficult to predict using today's room acoustic computer modeling software. The reasons why acoustics of class rooms are harder to predict than acoustics of complicated concert halls might be...

  3. Tunable acoustic metamaterials

    Babaee, Sahab; Viard, Nicolas; Fang, Nicholas; Bertoldi, Katia

    2015-03-01

    We report a new class of active and switchable acoustic metamaterials composed of three-dimensional stretchable chiral helices arranged on a two-dimensional square lattice. We investigate the propagation of sounds through the proposed structure both numerically and experimentally and find that the deformation of the helices can be exploited as a novel and effective approach to control the propagation of acoustic waves. The proposed concept expands the ability of existing acoustic metamaterials since we demonstrate that the deformation can be exploited to turn on or off the band gap, opening avenues for the design of adaptive noise-cancelling devices.

  4. Phononic crystals and acoustic metamaterials

    Ming-Hui Lu; Liang Feng; Yan-Feng Chen

    2009-01-01

    Phononic crystals have been proposed about two decades ago and some important characteristics such as acoustic band structure and negative refraction have stimulated fundamental and practical studies in acoustic materials and devices since then. To carefully engineer a phononic crystal in an acoustic “atom” scale, acoustic metamaterials with their inherent deep subwavelength nature have triggered more exciting investigations on negative bulk modulus and/or negative mass density. Acoustic surf...

  5. Acoustic integrated extinction

    Norris, Andrew N

    2015-01-01

    The integrated extinction (IE) is defined as the integral of the scattering cross-section as a function of wavelength. Sohl et al. [1] derived an IE expression for acoustic scattering that is causal, i.e. the scattered wavefront in the forward direction arrives later than the incident plane wave in the background medium. The IE formula was based on electromagnetic results, for which scattering is causal by default. Here we derive a formula for the acoustic IE that is valid for causal and non-causal scattering. The general result is expressed as an integral of the time dependent forward scattering function. The IE reduces to a finite integral for scatterers with zero long-wavelength monopole and dipole amplitudes. Implications for acoustic cloaking are discussed and a new metric is proposed for broadband acoustic transparency.

  6. Acoustics Noise Test Cell

    Federal Laboratory Consortium — The Acoustic Noise Test Cell at the NASA/Caltech Jet Propulsion Laboratory (JPL) is located adjacent to the large vibration system; both are located in a class 10K...

  7. Principles of musical acoustics

    Hartmann, William M

    2013-01-01

    Principles of Musical Acoustics focuses on the basic principles in the science and technology of music. Musical examples and specific musical instruments demonstrate the principles. The book begins with a study of vibrations and waves, in that order. These topics constitute the basic physical properties of sound, one of two pillars supporting the science of musical acoustics. The second pillar is the human element, the physiological and psychological aspects of acoustical science. The perceptual topics include loudness, pitch, tone color, and localization of sound. With these two pillars in place, it is possible to go in a variety of directions. The book treats in turn, the topics of room acoustics, audio both analog and digital, broadcasting, and speech. It ends with chapters on the traditional musical instruments, organized by family. The mathematical level of this book assumes that the reader is familiar with elementary algebra. Trigonometric functions, logarithms and powers also appear in the book, but co...

  8. Compact acoustic refrigerator

    Bennett, Gloria A.

    1992-01-01

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

  9. Acoustics lecturing in Mexico

    Beristain, Sergio

    2002-11-01

    Some thirty years ago acoustics lecturing started in Mexico at the National Polytechnic Institute in Mexico City, as part of the Bachelor of Science degree in Communications and Electronics Engineering curricula, including the widest program on this field in the whole country. This program has been producing acoustics specialists ever since. Nowadays many universities and superior education institutions around the country are teaching students at the B.Sc. level and postgraduate level many topics related to acoustics, such as Architectural Acoustics, Seismology, Mechanical Vibrations, Noise Control, Audio, Audiology, Music, etc. Also many institutions have started research programs in related fields, with participation of medical doctors, psychologists, musicians, engineers, etc. Details will be given on particular topics and development.

  10. Acoustic Igniter Project

    National Aeronautics and Space Administration — An acoustic igniter eliminates the need to use electrical energy to drive spark systems to initiate combustion in liquid-propellant rockets. It does not involve the...

  11. Thermal Acoustic Fatigue Apparatus

    Federal Laboratory Consortium — The Thermal Acoustic Fatigue Apparatus (TAFA) is a progressive wave tube test facility that is used to test structures for dynamic response and sonic fatigue due to...

  12. Acoustic Neuroma Educational Video

    Full Text Available ... treatment Summary Types Of Post-treatment Issues Resources Medical Resources Considerations When Selecting a Healthcare Professional Healthcare ... ANA? Mission Statement Board of Directors ANA Staff Medical Advisory Board News ANA Annual Reports Acoustic Neuroma ...

  13. Acoustic coherent perfect absorbers

    In this paper, we explore the possibility of achieving acoustic coherent perfect absorbers. Through numerical simulations in two dimensions, we demonstrate that the energy of coherent acoustic waves can be totally absorbed by a fluid absorber with specific complex mass density or bulk modulus. The robustness of such absorbing systems is investigated under small perturbations of the absorber parameters. We find that when the resonance order is the lowest and the size of the absorber is comparable to the wavelength in the background, the phenomenon of perfect absorption is most stable. When the wavelength inside both the background and the absorber is much larger than the size of the absorber, perfect absorption is possible when the mass density of the absorber approaches the negative value of the background mass density. Finally, we show that by using suitable dispersive acoustic metamaterials, broadband acoustic perfect absorption may be achieved. (papers)

  14. Ocean acoustic reverberation tomography.

    Dunn, Robert A

    2015-12-01

    Seismic wide-angle imaging using ship-towed acoustic sources and networks of ocean bottom seismographs is a common technique for exploring earth structure beneath the oceans. In these studies, the recorded data are dominated by acoustic waves propagating as reverberations in the water column. For surveys with a small receiver spacing (e.g., tomography, is developed that uses the travel times of direct and reflected waves to image ocean acoustic structure. Reverberation tomography offers an alternative approach for determining the structure of the oceans and advancing the understanding of ocean heat content and mixing processes. The technique has the potential for revealing small-scale ocean thermal structure over the entire vertical height of the water column and along long survey profiles or across three-dimensional volumes of the ocean. For realistic experimental geometries and data noise levels, the method can produce images of ocean sound speed on a smaller scale than traditional acoustic tomography. PMID:26723303

  15. Autonomous Acoustic Receiver System

    Federal Laboratory Consortium — FUNCTION: Collects underwater acoustic data and oceanographic data. Data are recorded onboard an ocean buoy and can be telemetered to a remote ship or shore station...

  16. Acoustic emission source modeling

    Hora, Petr; Červená, Olga

    Plzeň : University of West Bohemia, 2009 - (Adámek, V.; Zajíček, M.). s. 1-2 ISBN 978-80-7043-824-4. [Výpočtová mechanika 2009. 09.11.2009-11.11.2009, Nečtiny] R&D Projects: GA ČR GA101/09/1630 Institutional research plan: CEZ:AV0Z20760514 Keywords : acoustic emission source * wave propagation * FEM Subject RIV: BI - Acoustics

  17. The autonomous acoustic buoy

    Pellicer, Francisco; Reitsma, Robert; Agüera, Joaquín; Marinas, Alexandra

    2013-01-01

    The Acoustic Buoy is a project between the Laboratory of Applied Bioacoustics (LAB) and the Universitat Politècnica de Catalunya (UPC). In areas that the human activities produce high noise levels, such as oil exploration or construction, there is a need to monitor the environment for the presence of cetaceans. Another need is for fishing, to prevent endangered species from being killed. This can be done with an Autonomous Acoustic Buoy (AAB). Mooring or anchoring at to the seaflo...

  18. Anal acoustic reflectometry

    Mitchell, Peter J; Klarskov, Niels; Telford, Karen J; Hosker, Gordon L; Lose, Gunnar; Kiff, Edward S

    2011-01-01

    Anal acoustic reflectometry is a new technique of assessing anal sphincter function. Five new variables reflecting anal canal function are measured: the opening and closing pressure, the opening and closing elastance, and hysteresis.......Anal acoustic reflectometry is a new technique of assessing anal sphincter function. Five new variables reflecting anal canal function are measured: the opening and closing pressure, the opening and closing elastance, and hysteresis....

  19. Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface.

    Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A

    2014-01-01

    Metasurfaces are a family of novel wavefront-shaping devices with planar profile and subwavelength thickness. Acoustic metasurfaces with ultralow profile yet extraordinary wave manipulating properties would be highly desirable for improving the performance of many acoustic wave-based applications. However, designing acoustic metasurfaces with similar functionality to their electromagnetic counterparts remains challenging with traditional metamaterial design approaches. Here we present a design and realization of an acoustic metasurface based on tapered labyrinthine metamaterials. The demonstrated metasurface can not only steer an acoustic beam as expected from the generalized Snell's law, but also exhibits various unique properties such as conversion from propagating wave to surface mode, extraordinary beam-steering and apparent negative refraction through higher-order diffraction. Such designer acoustic metasurfaces provide a new design methodology for acoustic signal modulation devices and may be useful for applications such as acoustic imaging, beam steering, ultrasound lens design and acoustic surface wave-based applications. PMID:25418084

  20. The microwave power dependence of the ESR absorption of the A12O3-MoO3-perylene system

    The input power dependence of the ESR absorption observed from the paramagnetic species formed in the perylene-γ-alumina-MoO3-benzene system was studied. A mixture of the molecular ions, P+ and P+Osup(*2-), interprets the input power dependence of the ESR spectrum obtained for the system prepared by an ordinary method. An analysing method by which the observed ESR spectrum can be separated in two component spectra has been established and was affirmed by a simulation. It has been found that a trace amount of H2O adsorbed on the oxide surface strongly affects the cation ESR spectrum. Such effects are concluded to be due to the formation of a hydrogen bond between the proton of C19H11=C(deltasub(+))-H and the oxygen in a H2O or a surface oxygen anion Osup(*2-). The input power dependence curves are shown to be necessary for the quantitative analysis of the ESR spectra of these paramagnetic species formed on catalyst surfaces. (auth.)

  1. Tooth fossil dating with combined ESR/U-series methods for studying Middle-Early Pleistocene archaeological sites

    In this paper, we give a review on combined ESR/U-series methods for dating tooth fossil from Middle-Early Pleistocene sites. This approach allows estimating the history of uranium uptake in each dental tissue by using a one-parameter (p-value) diffusion equation, being more accurate than the conventional methods where the mode of uranium uptake is predetermined. Conventional ESR dating postulates two models: an early uptake (EU) model which assumes that uranium was incorporated shortly after the sample burial, and a linear uptake (LU) model where uranium is supposed to have been incorporated at a constant rate since the time of burial. The previous works stated that correct ESR age of a sample lies always somewhere between the EU and LU uptake ages. In recent years, combined ESR/U-series methods are becoming known as a unique approach for dating old fossils directly, and were applied on several archaeological sites in the world. The archaeologists and dating specialists in China are called on to make a good joint effort and collaboration in installing and developing the combined ESR/U-series dating methods and to carry out better studies on chronology of Middle-Early Pleistocene sites. (authors)

  2. Detection Characteristics of Gamma-Irradiated Seeds by using PSL, TL, ESR and GC/MS

    In this study, we investigated the applicability of the photostimulated luminescence (PSL), thermoluminescence (TL), electron spin resonance (ESR) and gas chromatography/mass spectrometry (GC/MS) methods for 5 seeds which are not allowed to be irradiated in Korea. All 5 seeds including evening primrose seed, safflower seed, rape seed, sunflower seed and flax seed were analyzed. Samples were irradiated at 1~10 kGy using a 60Co gamma-ray irradiator. In PSL study, the photon counts of all the unirradiated samples showed negative (lower than 700). The photon counts of irradiated (1, 5, 10 kGy) samples showed positive (higher than 5,000). In TL analysis, results showed that it is possible to apply TL method to all foods containing minerals. In ESR measurements, the ESR signal (single-line) intensity of irradiated foods was higher than non-irradiated foods. The hydrocarbons 1,7-hexadecadiene (C16:2) and 8-heptadecene (C17:1) from oleic acid were detected only in the irradiated samples before and after the treatment at doses ≥ 1 kGy, but they were not detected in non-irradiated samples before and after treatment. These two hydrocarbons could be used as markers to identify irradiated safflower seed, rape seed, Sunflower seed and flax seed. And then, the hydrocarbons 1,7,10-hexadecatriene (C16:3) and 6,9-heptadecadiene (C17:2) from linoleic acid were detected in the evening primrose seed, safflower seed and sunflower seed. According to the results, PSL, TL and GC/ MS methods were successfully applied to detect the irradiated foods. It is concluded that PSL, TL and GC/MS methods are suitable for detection of irradiated samples and a combined method is recommendable for enhancing the reliability of detection results. (author)

  3. ESR detection of free radicals produced in irradiated fresh fruits and dried foods

    Full text: Electron spin resonance (ESR) technique was used to measure the stability of free radicals produced by the irradiation treatment in mangoes and in four spices: black pepper, oregano, 'guajillo' chili and 'morron' chili. The ESR spectra for mangoes were scanned in three different parts from the seeds and were recorded in fresh and dried tissues. The ESR spectra in fresh tissue of no irradiated mangoes, were a sextet line signal produced by Mn2+ ion and a singlet centered at g = 2.00 produced by the endogenous radical. New resonances were observed in the irradiated samples at 1.5 mT and 3 mT respects to the center line for right and left side. These new resonance signals were-observed for eight days in mangoes treated at 1.00 kGy, and for three days at 0.15 kGy. The resonance due to the irradiation was observed in Iyophilized mangoes only one day after the treatment, in the vacuum dried samples, no new resonances were observed. The triplet signal, as well as the central single line appeared after irradiation in black pepper, morron chili and guajillo chili. These signals were also observed in the irradiated spices at any radiation dose higher than 1.0 kGy. The signals decrease promptly, in ten days after the 'irradiation. It was not possible to observe the triplet signal in oregano, even when the samples were analyzed immediately after irradiation treatment. The only signal observed in irradiated spice was the endogenous radical. This signal increased as the radiation dose increased and decreased during storage time at room temperature. Results showed that free radicals produced in irradiated fresh fruits or dried foods have a quick recombination. It was observed that in the spices the signal remains for several weeks meanwhile only eight days in mangoes. (Author)

  4. ESR detection of free radicals produced in irradiated fresh fruits and dried foods

    Bustos G, E. [CICATA, IPN, 07000 Mexico D.F. (Mexico); Gomes, V.; Garcia, F. [IQUNAM, 04500 Mexico D.F. (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico)

    2007-07-01

    Full text: Electron spin resonance (ESR) technique was used to measure the stability of free radicals produced by the irradiation treatment in mangoes and in four spices: black pepper, oregano, 'guajillo' chili and 'morron' chili. The ESR spectra for mangoes were scanned in three different parts from the seeds and were recorded in fresh and dried tissues. The ESR spectra in fresh tissue of no irradiated mangoes, were a sextet line signal produced by Mn{sup 2+} ion and a singlet centered at g = 2.00 produced by the endogenous radical. New resonances were observed in the irradiated samples at 1.5 mT and 3 mT respects to the center line for right and left side. These new resonance signals were-observed for eight days in mangoes treated at 1.00 kGy, and for three days at 0.15 kGy. The resonance due to the irradiation was observed in Iyophilized mangoes only one day after the treatment, in the vacuum dried samples, no new resonances were observed. The triplet signal, as well as the central single line appeared after irradiation in black pepper, morron chili and guajillo chili. These signals were also observed in the irradiated spices at any radiation dose higher than 1.0 kGy. The signals decrease promptly, in ten days after the 'irradiation. It was not possible to observe the triplet signal in oregano, even when the samples were analyzed immediately after irradiation treatment. The only signal observed in irradiated spice was the endogenous radical. This signal increased as the radiation dose increased and decreased during storage time at room temperature. Results showed that free radicals produced in irradiated fresh fruits or dried foods have a quick recombination. It was observed that in the spices the signal remains for several weeks meanwhile only eight days in mangoes. (Author)

  5. Data correction in ESR dosimetry for the average absorbed dose of teeth exposed to external photon

    A data-correction technique for the electron spin resonance (ESR) dosimetry was discussed in order to estimate an average absorbed dose of teeth exposed to external photon. Fourteen TLDs (thermoluminescent dosimeters) were used in the experiments to obtain the dose distribution in the human mouth. Each TLD was installed on the backside of the teeth in a female rando-phantom in order to estimate the absorbed dose of each tooth. The rando-phantom was exposed to photon beams of 137Cs (0.66 MeV) and 60Co (1.2/1.3 MeV) to investigate the influence of the energy on the dose distribution. The direction of the photons that hit the surface of the face could also affect the distribution of the dose in the phantom mouth. The incident angles of the photon beam were changed at 45-degree intervals around the longitudinal axis of the rando-phantom at the same height as the teeth. The largest difference among the measured doses, depending on the position of the teeth and photon energy, was in excess of 40% in the case of the exposure due to the beam direction from the backside of the phantom head at the energy of 662 keV. A sample of tooth enamel would be valuable for estimating the effective dose (Sv) calculated from the absorbed dose with ESR dosimetry. However, this study shows that the position of a tooth in the mouth affects the estimated value of an average absorbed dose of teeth. A simple technique to correct the ESR dosimetric results is suggested in this paper. The average absorbed dose of a tooth can be adequately estimated by using a simple formula that takes into consideration the position of the tooth, photon beam direction, and photon energy. (author)

  6. Oxovanadium (2) complexes with monothiophosphate ligands from the data of ESR

    Complexes of the composition VO (mtp)3 (2) and VO (MTP)2 (1), where mtp=monothiophosphate-ion in toluene solution, were identified by the ESR method. Complex 1 has a plane structure with VO2S2 coordination unit. It is assumed that complex 2 has the structure with one of the ligands bound in a bidentate way via S and 0 atoms, which is similar to the plane one. Two other ligands are bound in monodentate way via S and O atoms and coordination atoms of the ligands are weakly coordinated into axial positions

  7. Technical proposal of the 4π detector for SIS/ESR

    A 4π spectrometer for the detection of charged particles and photons produced in the SIS/ESR facility is proposed. It consists of a magnetic spectrometer with a central drift chamber, a two-arm photon spectrometer, an array of plastic scintillators, and a system consisting of silicon transmission detectors and gas-filled ionization chambers for the detection of nuclear fragments stopped in the scintillator modules. This system shall be able to measure correlations between photons and charged particles and to discriminate charged particles by tracking in the magnetic field. The data acquisition and processing systems are also described. (HSI)

  8. Influence of Thermal Homogenization Treatment on Structure and Impact Toughness of H13 ESR Steel

    MA Dang-shen; ZHOU Jian; CHEN Zai-zhi; ZHANG Zhong-kan; CHEN Qi-an; LI De-hui

    2009-01-01

    The as-cast microstrueture of H13 ESR ingot and the influence of high temperature diffusion treatment on the structure and impact toughness have been investigated. The results show that the dendrite arm spacing gradually becomes wide from the surface to the center of ingot, and the large primary carbide particles always exist in interdendritic segregation areas; by means of high temperature diffusion treatment of ingot prior to hot forging, the banded segregation is nearly eliminated, the annealed structure is more uniform and the isotropic properties have been improved remarkably.

  9. A study of the radiation chemistry of poly(chlorotrifluoroethylene) by ESR spectroscopy

    Hill, David J. T.; Thurecht, Kristofer J.; Whittaker, Andrew K.

    2003-12-01

    The ESR spectra of poly(chlorotrifluoroethylene) were recorded following γ-radiolysis under vacuum at room temperature and 77 K. The very broad spectrum at 77 K revealed little fine structure with which to identity the radicals formed upon irradiation, but subsequent photobleaching and annealing studies, together with radiolytic studies at higher temperatures, afforded scope for making radical assignments. Both main-chain radicals and a range of chain-end radicals have been identified. The G-values for radical formation were 1.55, 0.36 and 0.32 at 77 K, 273 K and room temperature, respectively.

  10. ESR of O3- trapped in γ-irradiated NaClO3

    The ESR spectra of γ-irradiated NaClO3 was analysed at Q-Band, between 110 to 300 K. The single crystals were annealed at 1800C until the spectra indicated the presence of only one paramagnetic center. This center was identified as the ozonide O3-. Four magnetically inequivalent sites per unit cell with symmetry axes along the cube diagonals were observed. The axial symmetry found for the g-tensor was interpreted in terms of molecule rotation around the trigonal axes. A rotational frequency of 2x109 c/s and an activation energy of 10 mev for the rotational motion could be estimated. (author)

  11. Quality assessment of coffee beans with ESR and gamma-ray irradiation

    Peroxy radical formation in raw coffee beans of different qualities and origins from all over the world has been studied with electron spin resonance (ESR) analysis. The γ-ray equivalent absorbed dose (ED) which creates the same concentration of radicals is obtained by the additive γ-ray irradiation of the coffee beans. The ED and the cup quality is somewhat inversely related suggesting that the peroxidation of the unsaturated fatty acid is somewhat indicative of the degree of the aromatic decomposition and rancidity. (author)

  12. ESR studies of some oxotetrahalo complexes of vanadium(IV) and molybdenum(V)

    ESR spectra of [VOF4]2- and [MoOF4]- have been studied in single crystals of (NH4)2SbF5 and spectra of [MoOCl4]- in single crystals of (NH4)2SbCl5. The spin-Hamiltonian parameters of these pentacoordinated complexes have been obtained and compared with those for the corresponding hexacoordinated species. Molecular orbital parameters for the penta- and hexacoordinated species obtained from experimental g- and A-tensor components have been compared with values calculated by the MS-SCF-Xα method

  13. Proceedings of the workshop on experiments and experimental facilities at SIS/ESR

    The present proceedings contain the abstracts of the proposals and letters of intent prepared by the authors for general distribution. The abstracts are organized according to the sessions in which they were presented at the workshop. The program of the workshop is also included as is the list of attendees. In addition we have included two recent descriptions of the accelerator facilities providing information on the latest status of the expected beam schedule for SIS and performance characteristics of the ESR. (orig./HSI)

  14. ESR dating of tooth samples from the paleoanthropological site of Yinshan, Chaoxian, Anhui

    Four tooth samples, collected from the 2nd, 3rd and 4th layer of a paleoanthropological site of Yinshan near Chaoxian are analyzed by ESR dating. Their ages are estimated to be 212 ka, 361ka, 363ka and 456ka respectively. The age of paleoanthropological fossils from the 2nd layer is about 200 ka, which is in good agreement with the results obtained by U-series dating or other methods for fauna remains as well as the paleoanthropological and paleontological evidence

  15. Retrospective Dosimetry: Dose Analysis From Tooth Enamel Using Electron Spin Resonance (ESR)

    The radiation dose should be accurately measured in order to relate its effect to the cells. The assessment of dose usually performed using biological dosimetry techniques. However, the reduction of lymphocytes (white blood cells) after the time period results in inaccuracy of dose measurement. An alternative method used is the application of Electron Spin Resonance (ESR) using tooth enamel. In this study, tooth enamels were evaluated and used to measure the individual absorbed dose from the background. The basic tooth features that would affect dose measurement were discussed. The results show this technique is capable and effective for retrospective dose measurement and useful for the study of radiation effect to human. (author)

  16. ESR studies on the radiolysis of crystalline materials at cryogenic temperatures

    Presently we report our recent works on the radiolysis of crystalline materials that were studied mainly by ESR spectroscopy. They include A)hydrocarbon radiolysis using hydrocarbon mixed crystals with hydrocarbon having a different molecular chain length, alkenes, and with alkynes, B)the structure and reactions of extremely unstable ions of alkenes, alkynes, and halogenated alkanes trapped in crystalline matrices at cryogenic temperatures, and C)transfer and reactions of electrons, holes, and H atoms, and H/D isotope effects in the radiolytic reactions of hydrocarbons and H2O/D2O mixed crystals. (author)

  17. Acoustic vector sensor signal processing

    SUN Guiqing; LI Qihu; ZHANG Bin

    2006-01-01

    Acoustic vector sensor simultaneously, colocately and directly measures orthogonal components of particle velocity as well as pressure at single point in acoustic field so that is possible to improve performance of traditional underwater acoustic measurement devices or detection systems and extends new ideas for solving practical underwater acoustic engineering problems. Although acoustic vector sensor history of appearing in underwater acoustic area is no long, but with huge and potential military demands, acoustic vector sensor has strong development trend in last decade, it is evolving into a one of important underwater acoustic technology. Under this background, we try to review recent progress in study on acoustic vector sensor signal processing, such as signal detection, DOA estimation, beamforming, and so on.

  18. Amplification of ESR1 may predict resistance to adjuvant tamoxifen in postmenopausal patients with hormone receptor positive breast cancer

    Nielsen, Kirsten Vang; Ejlertsen, Bent Laursen; Müller, Sven;

    2010-01-01

    The estrogen receptor (ER) is the target of tamoxifen, but endocrine therapies do not benefit all patients with ER positive tumors. We therefore hypothesized that copy number changes in the ESR1 gene, encoding ER, confer resistance. Within a consecutive series of ER positive, postmenopausal...... patients allocated to 5 years tamoxifen, we identified 61 patients with recurrence less than 4 years and 48 patients without recurrence at least 7 years after initiation of adjuvant tamoxifen. Archival tissue containing primary tumor was collected from 97 patients (89%). Tumor samples were analyzed for ESR...... significantly associated with poor disease-free survival (P = 0.0054) and overall survival (P = 0.0004). This pilot study supports our hypothesis that ESR1 amplification is associated with a poorer outcome following adjuvant treatment with tamoxifen in ER positive early breast cancer. This study also revealed...

  19. Estimation of accumulated dose of radiation by the method of ESR-spectrometry of dental enamel of mammals

    ESR-spectrometry was used to investigate radiation-induced paramagnetic centers in enamel of mammals: carnivores (polar bear and fox), ungulates (reindeer, European bison, moose), and man. Values at half the microwave power saturation of the radiation signal, P1/2, evaluated at room temperature, was found to range from 16 to 26 mW for animals and man. A new approach to discrimination of the radiation induced signal from the total ESR spectrum of reindeer enamel is proposed. ''Dose-response'' dependencies of enamel of different species mammals were measured within the dose range from 0.48 up to 10.08 Gy. Estimations of ''radiosensitivity'' enamel of carnivores and ungulates showed good agreement with radiosensitivity enamel of man by ESR method. (Author)

  20. Analysis of dose in teeth for estimation of effective dose by the electron spin resonance (ESR) dosimetry using dental enamels

    Dose in teeth was studied to develop a method that can predict effective dose from results by the Electron Spin Resonance (ESR) dosimetry using dental enamels for external photon exposure. Absorbed dose in teeth and effective dose were calculated by the Electron Gamma Shower Code Version 4 (EGS4). In the Monte Carlo calculations, a region for teeth was newly added to a mathematical human model. Experiments were carried out with a head phantom, which is made of tissue equivalent materials. ESR dosimetry was made with dental enamels irradiated at teeth-part in the head phantom. The absorbed dose in a mouth was also measured with TLDs exposed to gamma rays as the teeth. The Monte Carlo calculation and the experiment gave a quantitative relationship between absorbed dose in teeth and effective dose. The obtained data are considered to be useful for the retrospective individual dose assessment with ESR dosimetry using dental enamels. (author)

  1. Study on the Effect of ESR and FSH β Genes on Litter Size in Local Northeast Three Pig Breeds

    2003-01-01

    The method of PCR-RFLP was used to analyze the effects of ESR and FSH β genotypes on the litter size,especially the corresponding changes with the difference of genotype distributions in the Min,Sanjiang and Junmu I pigs.The results show that the ESR and FSH β genes are the major genes of litter size;the heterozygous genotype for ESR as well as for FSH β locus has a more litter size than others.However,the combined genotype ABDD means a more litter size than other genotypes,the frequencies of the heterozygous genotypes in Sanjiang and Junmu I are lower than in Min which maybe one of the most important reasons for the little litter sizes of those two breeds.

  2. Acoustic comfort in eating establishments

    Svensson, David; Jeong, Cheol-Ho; Brunskog, Jonas

    2014-01-01

    The subjective concept of acoustic comfort in eating establishments has been investigated in this study. The goal was to develop a predictive model for the acoustic comfort, by means of simple objective parameters, while also examining which other subjective acoustic parameters could help explain...... the feeling of acoustic comfort. Through several layers of anal ysis, acoustic comfort was found to be rather complex, and could not be explained entirely by common subjective parameters such as annoyance, intelligibility or privacy. A predictive model for the mean acoustic comfort for an eating...

  3. Phononic crystals and acoustic metamaterials

    Ming-Hui Lu

    2009-12-01

    Full Text Available Phononic crystals have been proposed about two decades ago and some important characteristics such as acoustic band structure and negative refraction have stimulated fundamental and practical studies in acoustic materials and devices since then. To carefully engineer a phononic crystal in an acoustic “atom” scale, acoustic metamaterials with their inherent deep subwavelength nature have triggered more exciting investigations on negative bulk modulus and/or negative mass density. Acoustic surface evanescent waves have also been recognized to play key roles to reach acoustic subwavelength imaging and enhanced transmission.

  4. ESR lineshape and 1H spin-lattice relaxation dispersion in propylene glycol solutions of nitroxide radicals – Joint analysis

    Electron Spin Resonance (ESR) spectroscopy and Nuclear Magnetic Relaxation Dispersion (NMRD) experiments are reported for propylene glycol solutions of the nitroxide radical: 4-oxo-TEMPO-d16 containing 15N and 14N isotopes. The NMRD experiments refer to 1H spin-lattice relaxation measurements in a broad frequency range (10 kHz–20 MHz). A joint analysis of the ESR and NMRD data is performed. The ESR lineshapes give access to the nitrogen hyperfine tensor components and the rotational correlation time of the paramagnetic molecule. The NMRD data are interpreted in terms of the theory of paramagnetic relaxation enhancement in solutions of nitroxide radicals, recently presented by Kruk et al. [J. Chem. Phys. 138, 124506 (2013)]. The theory includes the effect of the electron spin relaxation on the 1H relaxation of the solvent. The 1H relaxation is caused by dipole-dipole interactions between the electron spin of the radical and the proton spins of the solvent molecules. These interactions are modulated by three dynamic processes: relative translational dynamics of the involved molecules, molecular rotation, and electron spin relaxation. The sensitivity to rotation originates from the non-central positions of the interacting spin in the molecules. The electronic relaxation is assumed to stem from the electron spin–nitrogen spin hyperfine coupling, modulated by rotation of the radical molecule. For the interpretation of the NMRD data, we use the nitrogen hyperfine coupling tensor obtained from ESR and fit the other relevant parameters. The consistency of the unified analysis of ESR and NMRD, evaluated by the agreement between the rotational correlation times obtained from ESR and NMRD, respectively, and the agreement of the translation diffusion coefficients with literature values obtained for pure propylene glycol, is demonstrated to be satisfactory

  5. ESR of dislocation defects in MgF2 crystals--with more than 130 line peaks

    Hou Bi-Hui; Zheng Ying-Guang; Shao Meng; Liu Feng-Yan; Fan Zhi-Da

    2005-01-01

    In this work, more than 130 line peaks in electron spin resonance (ESR) spectra have been discovered of the laser material MgF2 crystal in room-temperature experiments. A sample is cut from the shoulder part of the MgF2 crystal,and another is from the MgF2:Co crystal. The samples were not treated by any irradiation. The same anisotropic ESR spectra of the two samples indicate that the dopant Co2+ introduces defects which induce the same multinuclear free radicals as in dislocations in the sample of MgF2. These paramagnetic solid multinuclear free radicals show good stability, and their ESR spectra are found to be anisotropic. ESR signals are derived from three different types of multinuclear free radicals from a tentative simulation analysis.When the direction of the applied magnetic field is along the [100] or [010] orientation of the crystal, the magnetic field at which the ESR signals are detected ranges from 0.2294T to 0.4654T and the width of this range is 0.2362T (corresponding to an energy band of 0.233eV); the most narrow peak in the ESR spectra has a width △H about 1.28 × 10-3T.This width △H, equivalent to the energy difference of two neighbouring levels, is very small, only 1.85× 10-7eV (or 1.46 × 10-3cm- 1 ).This fact indicates that the ground state is highly degenerate, and splits into nearly quasi-continuous energy levels like an energy band in an applied magnetic field. It may be served as a new starting point of solid laser exciter frequency modulation.

  6. ESR of dislocation defects in MgF2 crystals—with more than 130 line peaks

    Hou, Bi-Hui; Zheng, Ying-Guang; Shao, Meng; Liu, Feng-Yan; Fan, Zhi-Da

    2005-07-01

    In this work, more than 130 line peaks in electron spin resonance (ESR) spectra have been discovered of the laser material MgF2 crystal in room-temperature experiments. A sample is cut from the shoulder part of the MgF2 crystal and another is from the MgF2:Co crystal. The samples were not treated by any irradiation. The same anisotropic ESR spectra of the two samples indicate that the dopant Co2+ introduces defects which induce the same multinuclear free radicals as in dislocations in the sample of MgF2. These paramagnetic solid multinuclear free radicals show good stability and their ESR spectra are found to be anisotropic. ESR signals are derived from three different types of multinuclear free radicals from a tentative simulation analysis. When the direction of the applied magnetic field is along the [100] or [010] orientation of the crystal, the magnetic field at which the ESR signals are detected ranges from 0.2294T to 0.4654T and the width of this range is 0.2362T (corresponding to an energy band of 0.233eV); the most narrow peak in the ESR spectra has a width ΔH about 1.28×10-3T. This width ΔH, equivalent to the energy difference of two neighbouring levels, is very small, only 1.85×10-7eV (or 1.46×10-3cm-1). This fact indicates that the ground state is highly degenerate and splits into nearly quasi-continuous energy levels like an energy band in an applied magnetic field. It may be served as a new starting point of solid laser exciter frequency modulation.

  7. ESR1 Gene Polymorphisms and Prostate Cancer Risk: A HuGE Review and Meta-Analysis.

    Yu-Mei Wang

    Full Text Available Many published data on the association between single nucleotide polymorphisms (SNPs in the ESR1 gene and prostate cancer susceptibility are inconclusive. The aim of this Human Genome Epidemiology (HuGE review and meta-analysis is to derive a more precise estimation of this relationship.A literature search of PubMed, Embase, Web of Science and Chinese Biomedical (CBM databases was conducted from their inception through July 1st, 2012. Crude odds ratios (ORs with 95% confidence intervals (CIs were calculated to assess the strength of association.Twelve case-control studies were included with a total 2,165 prostate cancer cases and 3,361 healthy controls. When all the eligible studies were pooled into the meta-analysis, ESR1 PvuII (C>T and XbaI (A>G polymorphisms showed no association with the risk of prostate cancer. However, in the stratified analyses based on ethnicity and country, the results indicated that ESR1 PvuII (C>T polymorphism was significantly associated with increased risk of prostate cancer among Asian populations, especially among Indian population; while ESR1 XbaI (A>G polymorphism may significantly increase the risk of prostate cancer among American population. Furthermore, we also performed a pooled analysis for all eligible case-control studies to explore the role of codon 10 (T>C, codon 325 (C>G, codon 594 (G>A and +261G>C polymorphisms in prostate cancer risk. Nevertheless, no significant associations between these polymorphisms and the risk of prostate cancer were observed.Results from the current meta-analysis indicate that ESR1 PvuII (C>T polymorphism may be a risk factor for prostate cancer among Asian populations, especially among Indian population; while ESR1 XbaI (A>G polymorphism may increase the risk of prostate cancer among American population.

  8. From Architectural Acoustics to Acoustical Architecture Using Computer Simulation

    Schmidt, Anne Marie Due; Kirkegaard, Poul Henning

    2005-01-01

    Architectural acoustics design has in the past been based on simple design rules. However, with a growing complexity in architectural acoustics and the emergence of room acoustic simulation programmes with considerable potential, it is now possible to subjectively analyse and evaluate acoustic...... properties prior to the actual construction of a building. With the right tools applied, acoustic design can become an integral part of the architectural design process. The aim of this paper is to investigate the field of application that an acoustic simulation programme can have during an architectural...... the first phases in the architectural process and set out a reverse strategy for simulation programmes to do so - from developing acoustics from given spaces to developing spaces from given acoustics...

  9. Standardization in high-level photon dosimetry based on ESR transfer metrology

    Industrial radiation processing under the aspects of safety and economy calls for high-level dose assessment, preferably by measurement. As far as public health is concerned, e.g. in sterilization of medical supplies, the observance of specified dose limits is of particular priority. This requires traceability of measurement to national standards. However, calibration service from Primary Standard Dosimetry Laboratories is not yet available for this dose range. Meanwhile, the broad variety of dosimetry systems operated in irradiator plants urgently demands international standardization. This could be provided by an international intercomparison service using an appropriate transfer dose meter. The present paper reports on a high-level dosimetry system elaborated at GSF for precision measurements. The system is based on the generation of long-living free radicals in approximately tissue-equivalent amino acid evaluated by an ESR technology of high metrological standard. The relevant dosimetric properties are elaborated such as dose range, detection limits, energy dependence of response and batch homogeneity. Besides, the results on the influence of ambient physical quantities are reported. The expectation value for the overall measuring uncertainty is estimated and compared with values achieved in international high-level dosimetry intercomparisons. Under the latter conditions overall uncertainties obtained were better than 7% on a 95% confidence level. As a result, the alanine/ESR metrology matches potentially the criteria of a transfer dosimetry system for standardization. (author)

  10. Radiolysis of carbohydrates as studied by ESR and spin-trapping

    Studies concerning the radicals produced in glycerol by reactions with OH radicals have been carried out by investigating deuterated glycerol (glycerol-d8) by spin-trapping with 2-methyl-2-nitrosopropane. Free radicals produced in linear carbohydrates such as xylitol, dulcitol, D-sorbitol and D-mannitol by reactions with OH radicals as well as by direct γ-radiolysis have been also investigated by spin-trapping. The ESR spectra of the spin-trapped radicals were analysed on the basis of the results from ESR and spin-trapping experiments on glycerol and deuterated glycerol, and the formation of three radical species, CHO-CH-, CH2-CO-and HO-CH-, due to both OH reactions and direct γ-radiolysis was confirmed for all compounds. The presence of a radical, -CO-CH-, was detected for xylitol, D-sorbitol and D-mannitol. General reaction processes induced by OH reactions or γ-radiolysis in the solid state are discussed. (author)

  11. The radiation chemistry of ultem at 77 K as revealed by ESR spectroscopy

    Radical formation in ultem following γ-radiolysis has been reassessed, and the G(R*) values at different temperatures have been determined by ESR spectroscopy. The radical assignment and radical reactivity have been re-examined by photobleaching and thermal annealing studies. Photobleachable radical anions were found to comprise ∼40% of the total number of radicals formed on radiolysis at 77 K. Spectral subtraction methods, ESR spectral simulations, measurement of g-values and the hyperfine splitting constants were used to identify the other radical intermediates. The principal chain scission radicals are formed due to scission of the main-chain at (i) the ether linkage, (ii) the isopropylidene group and (iii) the imide ring in the main chain. The side chain methyl groups of the isopropylidine units also lose hydrogen to form methylene radicals. The five-line spectrum observed to decay in the temperature range 370-430 K, which has not been assigned previously, has been identified as being characteristic of a di-substituted benzyl radical

  12. The radiation chemistry of ultem at 77 K as revealed by ESR spectroscopy

    Devasahayam, Sheila; Hill, David J.T. E-mail: hill@chemistry.uq.edu.au; Pomery, Peter J.; Whittaker, Andrew K

    2002-07-01

    Radical formation in ultem following {gamma}-radiolysis has been reassessed, and the G(R*) values at different temperatures have been determined by ESR spectroscopy. The radical assignment and radical reactivity have been re-examined by photobleaching and thermal annealing studies. Photobleachable radical anions were found to comprise {approx}40% of the total number of radicals formed on radiolysis at 77 K. Spectral subtraction methods, ESR spectral simulations, measurement of g-values and the hyperfine splitting constants were used to identify the other radical intermediates. The principal chain scission radicals are formed due to scission of the main-chain at (i) the ether linkage, (ii) the isopropylidene group and (iii) the imide ring in the main chain. The side chain methyl groups of the isopropylidine units also lose hydrogen to form methylene radicals. The five-line spectrum observed to decay in the temperature range 370-430 K, which has not been assigned previously, has been identified as being characteristic of a di-substituted benzyl radical.

  13. The radiation chemistry of ultem at 77 K as revealed by ESR spectroscopy

    Devasahayam, Sheila; Hill, David J. T.; Pomery, Peter J.; Whittaker, Andrew K.

    2002-07-01

    Radical formation in ultem following γ-radiolysis has been reassessed, and the G( R*) values at different temperatures have been determined by ESR spectroscopy. The radical assignment and radical reactivity have been re-examined by photobleaching and thermal annealing studies. Photobleachable radical anions were found to comprise ≈40% of the total number of radicals formed on radiolysis at 77 K. Spectral subtraction methods, ESR spectral simulations, measurement of g-values and the hyperfine splitting constants were used to identify the other radical intermediates. The principal chain scission radicals are formed due to scission of the main-chain at (i) the ether linkage, (ii) the isopropylidene group and (iii) the imide ring in the main chain. The side chain methyl groups of the isopropylidine units also lose hydrogen to form methylene radicals. The five-line spectrum observed to decay in the temperature range 370-430 K, which has not been assigned previously, has been identified as being characteristic of a di-substituted benzyl radical.

  14. ESR of trapped centers in γ irradiated silver chlorates single crystals

    The paramagnetic centers O-3, ClO2, and (ClO2--Cl)- have been identified in irradiated AgClO3 single crystals by X and Q band ESR experiments at room temperatures and by the optical absorption bands at 480 and 360 nm, characteristic of the first two centers, respectively. The ESR spectrum and its angular dependence show that the first two centers have two magnetically inequivalent sites per unit cell. The third center was clearly observed only at certain orientations. The data for ClO2 show that the principal directions of the g and A tensors do not coincide; the two magnetically inequivalent sites have similar principal values of the g and A tensors related by a 900 rotation about the tetragonal crystal axis of symmetry, and can therefore be assumed to be chemically equivalent. It is found that the ClO2 center is formed substitutionally in the ClO-3 ion position, but that the ozonide O-3 is not. The thermal annealing of the γ irradiated AgClO3 has revealed an increase in the concentration of the O-3 radical that seems to be connected with the simultaneous destruction of the ClO2 center

  15. Optical measurement of the longitudinal ion distribution of bunched ion beams in the ESR

    Wen, W. Q.; Lochmann, M.; Ma, X.; Bussmann, M.; Winters, D. F. A.; Nörtershäuser, W.; Botermann, B.; Geppert, C.; Frömmgen, N.; Hammen, M.; Hannen, V.; Jöhren, R.; Kühl, Th.; Litvinov, Yu. A.; Sánchez, R.; Stöhlker, Th.; Vollbrecht, J.; Weinheimer, C.; Dimopoulou, C.; Nolden, F.; Steck, M.

    2013-05-01

    An optical technique to study the longitudinal distribution of ions in a bunched ion beam circulating in a storage ring is presented. It is based on the arrival-time analysis of photons emitted after collisional excitation of residual gas molecules. The beam-induced fluorescence was investigated in the ultraviolet regime with a channeltron and in the visible region using a photomultiplier tube. Both were applied to investigate the longitudinal shape of bunched and electron-cooled 209Bi80+ ion beams at about 400 MeV/u in the experimental storage ring (ESR) at GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. Bunch lengths were determined with an uncertainty of about 0.5 m using the UV-sensitive channeltron and with slightly lower accuracy from the photomultiplier data due to the slower transitions in the red region of the spectrum. The Gaussian shape of the longitudinal distribution of ions inside the bunch was confirmed. With the information of the transverse beam size that can be measured simultaneously by a newly installed ionization profile monitor (IPM) at the ESR, an accurate determination of the ion density in the bunched beam will be allowed.

  16. E-layer dominated ionosphere observed by EISCAT/ESR radars during solar minimum

    Cai, Hongtao; Li, Fei; Shen, Ge; Zhan, Weijia; Zhou, Kangjun; McCrea, Ian W.; Ma, Shuying

    2014-05-01

    E-layer dominated ionosphere (ELDI) is referred to vertical profiles having peak density at E-layer altitudes (Mayer and Jakowski, 2009). In this paper, characteristics of ELDI were investigated with the help of field-aligned measurements of EISCAT/ESR radars during 2009-2011. ELDI events were identified with simple but reasonable criterions, in which a minimal duration was required to exclude possible 'fake' events induced by random errors in measurements. It was found that ELDI were observed more often in winter than other seasons. In winter, occurrence of ELDI peaks around mid-night at auroral latitude, while it reaches its maximum around geomagnetic local noon at ESR latitude. Our results imply that ELDI looks like a sporadic rather than a regular phenomenon, being contrary to previous results inferred from radio occultation measurements. Discrepancy in duration of ELDI events observed by the two radars is remarkable, being 30 minutes at TromsØ on average and about a half of it at Svalbard. During the presence of ELDI, average thickness of E-layer exhibits undetectable variations at the two sites, as well as HmE and the ratio of NmE/NmF. Case studies reveal that either extra E-layer ionization possible induced by auroral precipitation or density depletion in F-layer caused by plasma convection alone could lead to the presence of ELDI. We suggest that both them play an important role in ELDI formation.

  17. Optical measurement of the longitudinal ion distribution of bunched ion beams in the ESR

    An optical technique to study the longitudinal distribution of ions in a bunched ion beam circulating in a storage ring is presented. It is based on the arrival-time analysis of photons emitted after collisional excitation of residual gas molecules. The beam-induced fluorescence was investigated in the ultraviolet regime with a channeltron and in the visible region using a photomultiplier tube. Both were applied to investigate the longitudinal shape of bunched and electron-cooled 209Bi80+ ion beams at about 400 MeV/u in the experimental storage ring (ESR) at GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. Bunch lengths were determined with an uncertainty of about 0.5 m using the UV-sensitive channeltron and with slightly lower accuracy from the photomultiplier data due to the slower transitions in the red region of the spectrum. The Gaussian shape of the longitudinal distribution of ions inside the bunch was confirmed. With the information of the transverse beam size that can be measured simultaneously by a newly installed ionization profile monitor (IPM) at the ESR, an accurate determination of the ion density in the bunched beam will be allowed. -- Highlights: ► Optical methods to measure the bunch shape of ion beam at storage ring. ► High resolution of bunch length was obtained from the UV-sensitive channeltron. ► The Gaussian shape of longitudinal distribution of the ions in the bunch was confirmed

  18. Use of ESR and HPLC to follow the anaerobic reaction catalysed by lipoxygenases.

    Brandicourt, Stéphanie; Nicolas, Jacques; Boussard, Aline; Riquet, Anne-Marie

    2015-02-01

    The measurement of the 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL) consumption by using ESR allows to follow the anaerobic reaction between linoleic acid (LH) and its 13-hydroperoxide (LOOH) catalysed by lipoxygenase. During this reaction, two types of radicals are initially obtained, alkyl (L) and alkoxyl (LO) radicals which formed two types of adducts (LT and OLT) with TEMPOL as characterised by HPLC. The stoichiometry of the adduct formation is two mole of TEMPOL consumed for one mole of LH and one mole of LOOH. Using ESR, the kinetic parameters and the mechanism of the anaerobic reaction have been determined at pH 6.5 for three different lipoxygenases, soybean, horse bean and wheat and compared to the values obtained at pH 9 for soybean lipoxygenase. Wheat lipoxygenase is very weakly active compared to the other enzymes. An uncompetitive inhibition of the anaerobic reaction catalysed by soybean and horse bean lipoxygenases was observed with 2,6-di-tert-butyl-4-methylphenol (BHT). PMID:25172715

  19. Oxygen diffusion-concentration in phospholipidic model membranes. An ESR-saturation study

    Fully hydrated liposomes of dipalmitoyl-phosphatidylcholine were labelled with 5 (or 7, 10, 12, 16)-doxyl stearic acid at pH 6 and 8, and studied by the continuous wave ESR-saturation technique. The ESR spectral magnitude depends on the hyperfrequency power P and on both T1 and T2 relaxation times. Saturation, i.e. the non linearity of the spectral magnitude plotted versus √P can be quantified by a P1/2 parameter (power at which the signal is half as great as it would be without saturation). If we assume T2 weakly modified by spin exchange between paramagnetic spin probe and oxygen in triplet state, P1/2 is inversely proportional to T1, and becomes a sensitive parameter to appreciate the oxygen transport (oxygen diffusion-concentration product) inside the bilayers. According to the DPPC bilayer phase transition diagrams, P1/2 (oxygen diffusion-concentration) is related to the thermodynamic state of the membrane. This technique provides further informations on a particular property of a radioprotective agent, cysteamine, which seems to inhibit spin-triplet exchange and hence maximizes T1 (minimizes P1/2). Since radioprotective agents are known to act by scavenging radiation-induced free radicals and by inhibiting oxygen-dependent free radical processes, such a result may contribute to elucidate radioprotecting mechanisms

  20. Improvement of ESR dosimetry for thermal neutron beams through the addition of gadolinium

    Brai, M [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Marrale, M [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Gennaro, G [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Bartolotta, A [Dipartimento Farmacochimico, Tossicologico e Biologico, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy); D' Oca, M C [Dipartimento Farmacochimico, Tossicologico e Biologico, Universita di Palermo, via Archirafi 32, 90123 Palermo (Italy); Rosi, G [Centro di Ricerche ENEA, Casaccia, Rome (Italy)

    2007-09-07

    In this paper, the addition of gadolinium is proposed as a useful tool to enhance the electron spin resonance (ESR) sensitivity of organic compounds to thermal neutrons. The target of this work is the detection, through the ESR technique, of the thermal neutron fluence in a mixed field of photons and neutrons. Gadolinium was chosen because it has a very high capture cross section to thermal neutrons; its nuclear reaction with thermal neutrons induces complex inner shell transitions that generate, besides other particles, Auger electrons, which in turn release their energy in the neighborhood (only several nanometers) of the place of reaction. Gadolinium was added to two organic molecules: alanine and ammonium tartrate. The main result obtained was a greater neutron sensitivity for dosimeters with gadolinium than for those without gadolinium for both organic molecules used. Since a dosimeter pair is required to discriminate between the two components of a mixed field, we studied the response of each dosimeter pair irradiated in a mixed field. Through a blind test we verified the usefulness of this dosimetric system and we obtained an estimate of the fluence in the mixed field with a relative uncertainty of 3%, when the pair composed of an alanine dosimeter and a dosimeter with alanine and gadolinium is used.

  1. TL, OSL and ESR properties of nanostructured KAlSi3O8:Mn Glass

    Glass samples of KAlSi3O8:Mn were synthesized by sol-gel technique and the incorporation effects of Mn on the TL, OSL and ESR signals were studied. Its morphologies were analyzed through Transmission Electron Microscopy (TEM), Energy Dispersive Spectroscopy (EDS). Samples were obtained with five different molar concentrations of 0.25, 0.5, 1, 2 and 5 mol% of Mn. TEM micrographs indicated the occurrence of nanoparticles of Mn2SiO4 with 200 nm of size approximately. Results of TL spectra showed a broad emission band from 450 to 700 nm with a peak at 575 nm approximately, and fitting very well with the characteristic lines of the Mn2+ emission features. The OSL decay can be fitted by a sum of two exponentials. A proportional dose response curves of the OSL and TL for samples irradiated with γ-rays were verified. ESR results supplied six lines related to Mn2+ ions are observed superposed by a large isotropic line; the Hamiltonian components of these lines determined through simulation are I = 5/2, s = 5/2, g = 2.0060, A = 8.3 mT and s = 1/2, g = 2.0007 for the Mn2+ and isotropic lines.

  2. Identification of γ-irradiated spices by electron spin resonance (ESR) spectrometry

    The electron spin resonance (ESR) spectrometry spectra of white (WP), black (BP) and red (Capsicum annuum L. var. frutescerns L., RP) peppers each had a principal signal with a g-value of 2.0043, and the intensities of the principal signals were increased not only by γ-irradiation but also by heating. Irradiated RP also showed a minor signal -30G from the principal one, and the intensity of the minor signal increased linearly with increasing dose from 10 to 50 kGy. Since the minor signal was observed in RP irradiated at 10 kGy and stored for one year, but did not appear either after heating or after exposure to this signal is unique to γ-irradiated RP and should therefore be useful for the identification of γ-irradiated spices of Capsicum genus, such as paprika and chili pepper. The computer simulation of the ESR spectra suggested that the minor signal should be assigned to methyl radical and the principal signal mainly to a combination of phenoxyl and peroxyl radicals. Such minor signals were found in γ-irradiated allspice and cinnamon among 10 kinds of other spices. (author)

  3. Problems associated with reworked teeth in electron spin resonance (ESR) dating

    Blackwell, Bonnie A.

    A single radiation-sensitive ESR signal at g = 2.0018 occurs in well crystallized fossil tooth enamel, but not in modern teeth. In dating fossil teeth, the equivalent radiation dose (A Σ needed to produce the observed ESR signal is the integral, with respect to time, of the natural, environmental dose rate experienced by the tooth after its deposition. Regardless of the uranium (U) uptake history assumed, a reliable age estimate requires a good estimate for the external dose rate during the tooth's history. If teeth in a stratigraphic unit have been reworked from older units or are post-depositional intrusions, external dose rates measured in situ do not accurately reflect those experienced by the tooth. For teeth from a single unit, significant variations in the calculated ages, A Σs, enamel or dentine U concentrations all indicate mixed sample collections. Where enough subsamples can be collected from single teeth, isochron analyses negate the need for a separate external dose measurement, while calculating the sample age and the external dose rate experienced by the tooth. Failing that, modelling the sedimentary dose rates using time-averaged total external dose calculations becomes necessary. These principles are illustrated using teeth from the australopithecine sites Sterkfontein and Swartkrans, South Africa.

  4. Identification of. gamma. -irradiated spices by electron spin resonance (ESR) spectrometry

    Uchiyama, Sadao; Kawamura, Yoko; Saito, Yukio (National Inst. of Hygienic Sciences, Tokyo (Japan))

    1990-12-01

    The electron spin resonance (ESR) spectrometry spectra of white (WP), black (BP) and red (Capsicum annuum L. var. frutescerns L., RP) peppers each had a principal signal with a g-value of 2.0043, and the intensities of the principal signals were increased not only by {gamma}-irradiation but also by heating. Irradiated RP also showed a minor signal -30G from the principal one, and the intensity of the minor signal increased linearly with increasing dose from 10 to 50 kGy. Since the minor signal was observed in RP irradiated at 10 kGy and stored for one year, but did not appear either after heating or after exposure to this signal is unique to {gamma}-irradiated RP and should therefore be useful for the identification of {gamma}-irradiated spices of Capsicum genus, such as paprika and chili pepper. The computer simulation of the ESR spectra suggested that the minor signal should be assigned to methyl radical and the principal signal mainly to a combination of phenoxyl and peroxyl radicals. Such minor signals were found in {gamma}-irradiated allspice and cinnamon among 10 kinds of other spices. (author).

  5. In vivo copper-mediated free radical production: an ESR spin-trapping study

    Kadiiska, Maria B.; Mason, Ronald P.

    2002-04-01

    Copper has been suggested to facilitate oxidative tissue injury through a free radical-mediated pathway analogous to the Fenton reaction. By applying the electron spin resonance (ESR) spin-trapping technique, evidence for hydroxyl radical formation in vivo was obtained in rats treated simultaneously with copper and ascorbic acid or paraquat. A secondary radical spin-trapping technique was used in which the hydroxyl radical formed the methyl radical upon reaction with dimethylsulfoxide. The methyl radical was then detected by ESR spectroscopy as its adduct with the spin trap phenyl- N- t-butyl- nitrone (PBN). In contrast, lipid derived radical was detected in vivo in copper-challenged, vitamin E and selenium-deficient rats. These findings support the proposal that dietary selenium and vitamin E can protect against lipid peroxidation and copper toxicity. Since copper excreted into the bile from treated animals is expected to be maintained in the Cu(I) state (by ascorbic acid or glutathione), a chelating agent that would redox-stablilize it in the Cu(I) state was used to prevent ex vivo redox chemistry. Bile samples were collected directly into solutions of bathocuproinedisulfonic acid, a Cu(I)-stabilizing agent, and 2,2'-dipyridyl, a Fe(II)-stabilizing agent. If these precautions were not taken, radical adducts generated ex vivo could be mistaken for radical adducts produced in vivo and excreted into the bile.

  6. Radiation induced radical in barium sulphate for ESR dosimetry: a preliminary study

    Barium sulphate (BaSO4) was irradiated by γ-rays and analyzed with electron spin resonance (ESR) to study radiation induced radicals for materials as radiation dosimeter. The ESR spectrum for the radical species is characterized by a hole-type center with g factor of 2.019, 2.0127 and 2.0103 and electron-type center with g factor of 2.0039, 2.0025 and 2.0001. The dosimetric signal with splitting factors of g=2.0039 is ascribed to SO3- radicals and 5G linewidth. The response to γ-ray dose ranging from 5 to 103 Gy, energy dependence calculation and the thermal stability have been studied. The number of free radicals per 100 eV (G-value) was obtained to be 0.25 ± 0.06 and 0.9 ± 0.18 for BaSO4 and alanine, respectively. The lifetime of radicals and the activation energy were estimated from Arrhenius plots to be approximately 325 ± 60 days, and 0.50 ± 0.09 eV respectively

  7. Photochemical synthesis of simple organic free radicals on simulated planetary surfaces - An ESR study

    Tseng, S.-S.; Chang, S.

    1975-01-01

    Electron spin resonance (ESR) spectroscopy provided evidence for formation of hydroxyl radicals during ultraviolet photolysis (254 nm) at -170 C of H2O adsorbed on silica gel or of silica gel alone. The carboxyl radical was observed when CO or CO2 or a mixture of CO and CO2 adsorbed on silica gel at -170 C was irradiated. The ESR signals of these radicals slowly disappeared when the irradiated samples were warmed to room temperature. However, reirradiation of CO or CO2, or the mixture CO and CO2 on silica gel at room temperature then produced a new species, the carbon dioxide anion radical, which slowly decayed and was identical with that produced by direct photolysis of formic acid adsorbed on silica gel. The primary photochemical process may involve formation of hydrogen and hydroxyl radicals. Subsequent reactions of these radicals with adsorbed CO or CO2 or both yield carboxyl radicals, CO2H, the precursors of formic acid. These results confirm the formation of formic acid under simulated Martian conditions and provide a mechanistic basis for gauging the potential importance of gas-solid photochemistry for chemical evolution on other extraterrestrial bodies, on the primitive earth, and on dust grains in the interstellar medium.

  8. Synthesis of silver nanoparticles using DL-alanine for ESR dosimetry applications

    The potential use of alanine for the production of nanoparticles is presented here for the first time. Silver nanoparticles were synthesized using a simple green method, namely the thermal treatment of silver nitrate aqueous solutions with DL-alanine. The latter compound was employed both as a reducing and a capping agent. Particles with average size equal to 7.5 nm, face-centered cubic crystalline structure, narrow size distribution, and spherical shape were obtained. Interaction between the silver ions present on the surface of the nanoparticles and the amine group of the DL-alanine molecule seems to be responsible for reduction of the silver ions and for the stability of the colloid. The bio-hybrid nano-composite was used as an ESR dosimeter. The amount of silver nanoparticles in the nanocomposite was not sufficient to cause considerable loss of tissue equivalency. Moreover, the samples containing nanoparticles presented increased sensitivity and reduced energetic dependence as compared with pure DL-alanine, contributing to the construction of small-sized dosimeters. - Highlights: ► The synthesis is environmentally benign, easy to perform, and of low-cost. ► DL-Alanine was employed both as reducing and capping agent. ► Mean size of 7.5 nm, narrow size distribution, and spherical shape of particles. ► Increased sensitivity and reduced energetic dependence compared with pure alanine. ► The nanocomposite has potential application for ESR dosimetry.

  9. ESR Characterization and Activity of V2O5/γ-Al2O3 Catalysts for Dehydrogenation of Isobutane

    2002-01-01

    The ESR spectra of catalyst V2O5/γ-Al2O3 and its activity for the dehydrogenation of isobutane were investigated. On the basis of the results of the ESR spectroscopy associated with the TPR results, it is suggested that there is a strong interaction between V2O5 and γ-Al2O3 and the V4+ species on the surface is the active center of catalyst V2O5/γ-Al2O3 for this reaction.

  10. Effect of chemical treatment on ESR dosimetry of cow teeth: Application to the samples from Southern Urals

    Chemical treatment with alkaline solution is used to extract enamel from teeth for retrospective ESR (EPR) dosimetry. It was confirmed in the present study that our condition of chemical treatment does not affect retrospective doses of cow teeth. The method was applied to 10 teeth collected in the South Ural region where the soil is contaminated with 90Sr. As a result, no noticeable doses were detected so far. Significant variations of sensitivity of the radiation-induced ESR signal to radiation were found for different cow teeth, indicating that individual calibration is necessary

  11. ESR1 mutations affect anti-proliferative responses to tamoxifen through enhanced cross-talk with IGF signaling.

    Gelsomino, Luca; Gu, Guowei; Rechoum, Yassine; Beyer, Amanda R; Pejerrey, Sasha M; Tsimelzon, Anna; Wang, Tao; Huffman, Kenneth; Ludlow, Andrew; Andò, Sebastiano; Fuqua, Suzanne A W

    2016-06-01

    The purpose of this study was to address the role of ESR1 hormone-binding mutations in breast cancer. Soft agar anchorage-independent growth assay, Western blot, ERE reporter transactivation assay, proximity ligation assay (PLA), coimmunoprecipitation assay, silencing assay, digital droplet PCR (ddPCR), Kaplan-Meier analysis, and statistical analysis. It is now generally accepted that estrogen receptor (ESR1) mutations occur frequently in metastatic breast cancers; however, we do not yet know how to best treat these patients. We have modeled the three most frequent hormone-binding ESR1 (HBD-ESR1) mutations (Y537N, Y537S, and D538G) using stable lentiviral transduction in human breast cancer cell lines. Effects on growth were examined in response to hormonal and targeted agents, and mutation-specific changes were studied using microarray and Western blot analysis. We determined that the HBD-ESR1 mutations alter anti-proliferative effects to tamoxifen (Tam), due to cell-intrinsic changes in activation of the insulin-like growth factor receptor (IGF1R) signaling pathway and levels of PIK3R1/PIK3R3. The selective estrogen receptor degrader, fulvestrant, significantly reduced the anchorage-independent growth of ESR1 mutant-expressing cells, while combination treatments with the mTOR inhibitor everolimus, or an inhibitor blocking IGF1R, and the insulin receptor significantly enhanced anti-proliferative responses. Using digital drop (dd) PCR, we identified mutations at high frequencies ranging from 12 % for Y537N, 5 % for Y537S, and 2 % for D538G in archived primary breast tumors from women treated with adjuvant mono-tamoxifen therapy. The HBD-ESR1 mutations were not associated with recurrence-free or overall survival in response in this patient cohort and suggest that knowledge of other cell-intrinsic factors in combination with ESR1 mutation status will be needed determine anti-proliferative responses to Tam. PMID:27178332

  12. Wavefront Modulation and Subwavelength Diffractive Acoustics with an Acoustic Metasurface

    Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A.

    2014-01-01

    Metasurfaces are a family of novel wavefront shaping devices with planar profile and subwavelength thickness. Acoustic metasurfaces with ultralow profile yet extraordinary wave manipulating properties would be highly desirable for improving the performance of many acoustic wave-based applications. However, designing acoustic metasurfaces with similar functionality as their electromagnetic counterparts remains challenging with traditional metamaterial design approaches. Here we present a desig...

  13. ACOUSTICS IN ARCHITECTURAL DESIGN, AN ANNOTATED BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS.

    DOELLE, LESLIE L.

    THE PURPOSE OF THIS ANNOTATED BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS WAS--(1) TO COMPILE A CLASSIFIED BIBLIOGRAPHY, INCLUDING MOST OF THOSE PUBLICATIONS ON ARCHITECTURAL ACOUSTICS, PUBLISHED IN ENGLISH, FRENCH, AND GERMAN WHICH CAN SUPPLY A USEFUL AND UP-TO-DATE SOURCE OF INFORMATION FOR THOSE ENCOUNTERING ANY ARCHITECTURAL-ACOUSTIC DESIGN…

  14. Acoustic detection of pneumothorax

    Mansy, Hansen A.; Royston, Thomas J.; Balk, Robert A.; Sandler, Richard H.

    2003-04-01

    This study aims at investigating the feasibility of using low-frequency (pneumothorax detection were tested in dogs. In the first approach, broadband acoustic signals were introduced into the trachea during end-expiration and transmitted waves were measured at the chest surface. Pneumothorax was found to consistently decrease pulmonary acoustic transmission in the 200-1200-Hz frequency band, while less change was observed at lower frequencies (ppneumothorax states (pPneumothorax was found to be associated with a preferential reduction of sound amplitude in the 200- to 700-Hz range, and a decrease of sound amplitude variation (in the 300 to 600-Hz band) during the respiration cycle (pPneumothorax changed the frequency and decay rate of percussive sounds. These results imply that certain medical conditions may be reliably detected using appropriate acoustic measurements and analysis. [Work supported by NIH/NHLBI #R44HL61108.

  15. Seamount acoustic scattering

    Boehlert, George W.

    The cover of the March 1 issue of Eos showed a time series of acoustic scattering above Southeast Hancock Seamount (29°48‧N, 178°05‧E) on July 17-18, 1984. In a comment on that cover Martin Hovland (Eos, August 2, p. 760) argued that gas or “other far reaching causes” may be involved in the observed acoustic signals. He favors a hypothesis that acoustic scattering observed above a seeping pockmark in the North Sea is a combination of bubbles, stable microbubbles, and pelagic organisms and infers that this may be a more general phenomenon and indeed plays a role in the attraction of organisms to seamounts

  16. Acoustics waves and oscillations

    Sen, S.N.

    2013-01-01

    Parameters of acoustics presented in a logical and lucid style Physical principles discussed with mathematical formulations Importance of ultrasonic waves highlighted Dispersion of ultrasonic waves in viscous liquids explained This book presents the theory of waves and oscillations and various applications of acoustics in a logical and simple form. The physical principles have been explained with necessary mathematical formulation and supported by experimental layout wherever possible. Incorporating the classical view point all aspects of acoustic waves and oscillations have been discussed together with detailed elaboration of modern technological applications of sound. A separate chapter on ultrasonics emphasizes the importance of this branch of science in fundamental and applied research. In this edition a new chapter ''Hypersonic Velocity in Viscous Liquids as revealed from Brillouin Spectra'' has been added. The book is expected to present to its readers a comprehensive presentation of the subject matter...

  17. Practical acoustic emission testing

    2016-01-01

    This book is intended for non-destructive testing (NDT) technicians who want to learn practical acoustic emission testing based on level 1 of ISO 9712 (Non-destructive testing – Qualification and certification of personnel) criteria. The essential aspects of ISO/DIS 18436-6 (Condition monitoring and diagnostics of machines – Requirements for training and certification of personnel, Part 6: Acoustic Emission) are explained, and readers can deepen their understanding with the help of practice exercises. This work presents the guiding principles of acoustic emission measurement, signal processing, algorithms for source location, measurement devices, applicability of testing methods, and measurement cases to support not only researchers in this field but also and especially NDT technicians.

  18. Advanced Active Acoustics Lab (AAAL)

    Federal Laboratory Consortium — The Advanced Active Acoustics Lab (AAAL) is a state-of-the-art Undersea Warfare (USW) acoustic data analysis facility capable of both active and passive underwater...

  19. A New Wave of Acoustics.

    Beyer, Robert

    1981-01-01

    Surveys 50 years of acoustical studies by discussing selected topics including the ear, nonlinear representations, underwater sound, acoustical diagnostics, absorption, electrolytes, phonons, magnetic interaction, and superfluidity and the five sounds. (JN)

  20. A Century of Acoustic Metrology

    Rasmussen, Knud

    The development in acoustic measurement technique over the last century is reviewed with special emphasis on the metrological aspect.......The development in acoustic measurement technique over the last century is reviewed with special emphasis on the metrological aspect....

  1. Strong acoustic wave action

    Gokhberg, M. B.

    1983-07-01

    Experiments devoted to acoustic action on the atmosphere-magnetosphere-ionosphere system using ground based strong explosions are reviewed. The propagation of acoustic waves was observed by ground observations over 2000 km in horizontal direction and to an altitude of 200 km. Magnetic variations up to 100 nT were detected by ARIEL-3 satellite near the epicenter of the explosion connected with the formation of strong field aligned currents in the magnetosphere. The enhancement of VLF emission at 800 km altitude is observed.

  2. Acoustic black holes

    Visser, M

    1999-01-01

    Acoustic propagation in a moving fluid provides a conceptually clean and powerful analogy for understanding black hole physics. As a teaching tool, the analogy is useful for introducing students to both General Relativity and fluid mechanics. As a research tool, the analogy helps clarify what aspects of the physics are kinematics and what aspects are dynamics. In particular, Hawking radiation is a purely kinematical effect, whereas black hole entropy is intrinsically dynamical. Finally, I discuss the fact that with present technology acoustic Hawking radiation is almost experimentally testable.

  3. Structural Acoustics and Vibrations

    Chaigne, Antoine

    This structural chapter is devoted to vibrations of structures and to their coupling with the acoustic field. Depending on the context, the radiated sound can be judged as desirable, as is mostly the case for musical instruments, or undesirable, like noise generated by machinery. In architectural acoustics, one main goal is to limit the transmission of sound through walls. In the automobile industry, the engineers have to control the noise generated inside and outside the passenger compartment. This can be achieved by means of passive or active damping. In general, there is a strong need for quieter products and better sound quality generated by the structures in our daily environment.

  4. Densitometry By Acoustic Levitation

    Trinh, Eugene H.

    1989-01-01

    "Static" and "dynamic" methods developed for measuring mass density of acoustically levitated solid particle or liquid drop. "Static" method, unknown density of sample found by comparison with another sample of known density. "Dynamic" method practiced with or without gravitational field. Advantages over conventional density-measuring techniques: sample does not have to make contact with container or other solid surface, size and shape of samples do not affect measurement significantly, sound field does not have to be know in detail, and sample can be smaller than microliter. Detailed knowledge of acoustic field not necessary.

  5. Acoustic subwavelength imaging of subsurface objects with acoustic resonant metalens

    Cheng, Ying; Liu, XiaoJun, E-mail: liuxiaojun@nju.edu.cn [Key Laboratory of Modern Acoustics, Nanjing University, Nanjing 210093 (China); State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190 (China); Zhou, Chen; Wei, Qi; Wu, DaJian [Key Laboratory of Modern Acoustics, Nanjing University, Nanjing 210093 (China)

    2013-11-25

    Early research into acoustic metamaterials has shown the possibility of achieving subwavelength near-field acoustic imaging. However, a major restriction of acoustic metamaterials is that the imaging objects must be placed in close vicinity of the devices. Here, we present an approach for acoustic imaging of subsurface objects far below the diffraction limit. An acoustic metalens made of holey-structured metamaterials is used to magnify evanescent waves, which can rebuild an image at the central plane. Without changing the physical structure of the metalens, our proposed approach can image objects located at certain distances from the input surface, which provides subsurface signatures of the objects with subwavelength spatial resolution.

  6. Acoustic subwavelength imaging of subsurface objects with acoustic resonant metalens

    Early research into acoustic metamaterials has shown the possibility of achieving subwavelength near-field acoustic imaging. However, a major restriction of acoustic metamaterials is that the imaging objects must be placed in close vicinity of the devices. Here, we present an approach for acoustic imaging of subsurface objects far below the diffraction limit. An acoustic metalens made of holey-structured metamaterials is used to magnify evanescent waves, which can rebuild an image at the central plane. Without changing the physical structure of the metalens, our proposed approach can image objects located at certain distances from the input surface, which provides subsurface signatures of the objects with subwavelength spatial resolution

  7. Study of Cr(VI) Detoxification By basalt Inhabiting Bacteria Using NAA And ESR Methods

    Mixtures of heavy metals have polluted many industrial regions in the world. The environmental contamination with heavy metals has become a serious health concern. Since metal ions cannot be destroyed in environments, factors which influence the detoxification of metals can dictate the metal toxicity to ecological receptors. Indigenous bacteria have been considered as a potential candidate for detoxifying heavy metal ions. Molecular insight into the fate of heavy metal species in bacteria is important in the development of new bio technologies to clean-up contaminated sites. In our study chromium(VI), a widespread environmental pollution. was selected as a model heavy metal.Today there are only few studies that examine how microorganisms respond to chromium stress at higher doses. Instrumental neutron activation analysis (NAA) and electron spin resonance (ESR) methods were applied to evaluate the potential of indigenous bacteria to detoxify Cr(VI) from heavily contaminated environment. The microbial reduction of toxic Cr(VI) to less toxic Cr(III) was studied in batch systems in the presence of high concentrations of Cr(VI) (50-1000 mg/L). Gram-positive Arthrobacter oxydans isolated from Columbia basalts (USA) that have been polluted with mixtures of heavy metals, radionuclides and organic compounds and also two Gram-positive bacteria isolated from polluted basalts from the Republic of Georgia were tested under aerobic conditions. All the bacterial samples were exposed to Cr(VI) action at a given concentration for five days. NAA revealed that A. oxydans is able to accumulate Cr(VI) efficiently in the concentration range 50-500 mg/L. Dose-dependent ESR measurements of the formation of Cr(Ill) complexes (g=2.02, line width=650 gauss) in bacterial cells confirmed this character of Cr(VI) detoxification. The similar results are obtained for one of the bacterial isolate. For the other bacterium, the content of chromium inside the cells is increased continuously by

  8. Self-assembly of gelator molecules in liquid crystals studied by ESR

    Highlights: ► The event of HCCA crystallization is strongly affected by the presence of gelator 1. ► ESR technique detects the onset of gelator network self-assembly in nematic phase. ► The melting of gelator network is studied in the heating cycle. -- Abstract: Thermotropic liquid crystal trans-4-heptylcyclohexanecarboxylic acid (HCCA) doped with 4-oxo-2,2,6,6,-tetramethyl-1-piperidinyloxy spin probe (Tempone) is investigated by electron spin resonance (ESR) spectroscopy in the presence of chiral bisoxalamide gelator 1 during both cooling and heating cycles. In the temperature range 295–383 K, where HCCA displays isotropic, nematic, smectic B and crystalline phases, the impact of 1 self-organization was detected via (non) homogeneous partitioning of the spin probe in the environments varying in the polarity, an effect dependent on the gelator concentration. In particular, the evidence of the onset of the gelator network self-assembly in the nematic phase was detected by ESR at higher temperatures than the ones reported so far by other experimental techniques. Additionally, the spectral analysis points to the switching of the polarity in the vicinity of the spin probe when the transfer of chirality from 1 to HCCA upon cooling of the sample from isotropic to chiral nematic phase appears and when the event of LC gelation results in the achiral nematic phase during chiral gel fibers formation. When the gelation proceeds in the smectic phase, the melting of the gelator network is studied in the nematic phase during the heating cycle. Furthermore, the event of HCCA crystallization is shown to be strongly affected by the presence of 1 as well. The experimental evidence is provided that gelator network confines the HCCA into the domains within the bulk crystalline matrix where the local molecular dynamics are still not frozen. Therefore, we propose that non-homogeneous polarity profile of molecular organization/packing within LC gels could be determinable for the

  9. Underwater Acoustic Networking Techniques

    Otnes, Roald; Casari, Paolo; Goetz, Michael; Husøy, Thor; Nissen, Ivor; Rimstad, Knut; van Walree, Paul; Zorzi, Michele

    2012-01-01

    This literature study presents an overview of underwater acoustic networking. It provides a background and describes the state of the art of all networking facets that are relevant for underwater applications. This report serves both as an introduction to the subject and as a summary of existing protocols, providing support and inspiration for the development of network architectures.

  10. COMBUSTION ACOUSTICS DIAGNOSTICS

    This is an Exploratory Research Project that was awarded by APPCD for research on developing an acoustic flame condition monitor. It will involve a bench scale experiment of 4-6 weeks duration to record adjacent audible energy of a Bunsen burner. The experiment will require a d...

  11. Acoustic Signals and Systems

    present topics on signal processing which are important in a specific area of acoustics. These will be of interest to specialists in these areas because they will be presented from their technical perspective, rather than a generic engineering approach to signal processing. Non-specialists, or specialists...

  12. ESR and AMS-based 14C Dating of Mousterian Levels at Mujina Pećina, Dalmatia, Croatia

    Rink, W.J.; Karavanić, I.; Pettitt, P.B.; Plicht, J. van der; Smith, F.H.; Bartoll, J.; Karavanic, I.

    2002-01-01

    This paper presents the first chronometric dates for sediments that contain a Mousterian industry in Dalmatia (south Croatia). Electron spin resonance (ESR) dating was conducted on two teeth from the Mousterian level E1 at the site of Mujina Pećina. Additionally five bone and one charcoal sample fro

  13. Dating of the middle Palaeolithic site of Payre (Ardeche): new radiometric data (U-series and ESR methods)

    The site of Payre is located in Ardeche. Several archaeological layers containing lithic artefacts of Middle Palaeolithic were found. These artefacts lie associated with carbonate formations which are good chronostratigraphic markers. The U-series and ESR methods on bones and stalagmitic floors placed the human occupation between isotopic marine stages 7 and 4. (authors)

  14. The use of ESR spectroscopy for the detection of irradiated mechanically recovered meat (MRM) in tertiary food products

    The use of electron spin resonance (ESR) spectroscopy as a detection method for irradiated food has been well documented in recent years, the research dealing mainly with primary products such as chicken, shellfish and fruit. An example of how the technique can be applied to processed food products was demonstrated when ESR spectroscopy was used to differentiate between samples of commercially irradiated and non-irradiated mechanically recovered turkey meat (MRM). The latter refers to meat which has been mechanically removed under high pressure from irregularly shaped bones subjected to hand-boning operations. The paste-like product contains small fragments of bone which can be extracted and used for the purposes of ESR spectroscopy provided a sufficient quantity is recovered. On a commercial scale MRM can be incorporated into other food, such as beef burgers, to produce a tertiary product. The aim of this experimental work, carried out simultaneously in Belfast and Strasbourg, was to compare two methods for extracting bone fragments from such tertiary products containing MRM at varying inclusion rates and to determine if ESR spectroscopy could be used to qualitatively detect the presence of small amounts of irradiated MRM. In addition, a number of coded foods containing either non-irradiated MRM were examined in order to establish the feasibility of applying the method to samples, the processing history of which was unknown. (author)

  15. ESR study on free radicals produced from hexane by vacuum-ultraviolet photolysis, sensitized photolysis, and γ-radiolysis

    The free radicals generated from polycrystalline hexane at 77K by photolysis with vacuum-ultraviolet light, sensitized photolysis, and γ-radiolysis were compared with each others using the ESR method. The selectivity of radical formation was found to depend on the excitation method. (author)

  16. Direct observation of hexamethylbenzenium radical cations generated during zeolite methanol-to-olefin catalysis: an ESR study.

    Kim, Sun Jung; Jang, Hoi-Gu; Lee, Jun Kyu; Min, Hyung-Ki; Hong, Suk Bong; Seo, Gon

    2011-09-01

    The generation of hexamethylbenzenium radical cations as the key reaction intermediate in chabazite-type molecular sieve acids (i.e., H-SAPO-34 and H-SSZ-13) during the methanol-to-olefin process has been directly evidenced by ESR spectroscopy. PMID:21766115

  17. Irradiation and ESR analysis temperature dependence of the gamma-ray response of alanine-polystyrene dosimeters

    Kojima, T.; Morishita, N.; Itoh, H. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Biramontri, S. [Office of Atomic Energy for Peace, Bangkok (Thailand)

    1996-04-01

    Response characteristics of the alanine-polystyrene dosimeter were studied at an absorbed dose of 5 kGy over the low irradiation temperature range -196 {approx} 30{sup o}C, and the ESR analysis temperature range 0 {approx}50{sup o}C in the dose range 0.1 {approx} 10 kGy. The irradiation temperature coefficient previously estimated for the temperature range from 0 {approx} 70{sup o}C (+0.24%/.{sup o}C) was verified down to -15{sup o}C, although about 8% lower values were obtained at -78 and -196{sup o}C based on the correction using the above coefficient. ESR intensity decreases with temperature during ESR analysis following the function of the reciprocal of absolute temperature based on Boltzmann`s constant. The average temperature coefficient for three different dose levels during ESR analysis of the alanine-polystyrene dosimeter is -0.25%/K in the temperature range 0 {approx} 50{sup o}C. (Author).

  18. ESR1/SYNE1 polymorphism and invasive epithelial ovarian cancer risk: an Ovarian Cancer Association Consortium study

    Doherty, Jennifer A; Rossing, Mary Anne; Cushing-Haugen, Kara L;

    2010-01-01

    , respectively. A SNP 19 kb downstream of ESR1 (rs2295190, G-to-T change) was associated with invasive ovarian cancer risk, with a per-T-allele odds ratio (OR) of 1.24 [95% confidence interval (CI), 1.06-1.44, P = 0.006]. rs2295190 is a nonsynonymous coding SNP in a neighboring gene called spectrin repeat...

  19. Model membrane partition ESR study in the presence of alpha-tocopherol by a new spin probe

    Severcan, F.; Cannistraro, S. (Dipartimento di Fisica dell' Universita, Perugia (Italy))

    1989-08-01

    The effect of alpha-tocopherol (alpha T) on partitioning and fluidity changes occurring in phospholipid liposomes have been investigated by monitoring the X-band ESR spectrum of the high resolution amphiphilic spin probe perdeutero-di-t-butyl nitroxide (PDDTBN), which partitions in the lipid and water phase of liposomes, showing all the three resonances from each phase well resolved.

  20. Model membrane partition ESR study in the presence of alpha-tocopherol by a new spin probe

    The effect of alpha-tocopherol (alpha T) on partitioning and fluidity changes occurring in phospholipid liposomes have been investigated by monitoring the X-band ESR spectrum of the high resolution amphiphilic spin probe perdeutero-di-t-butyl nitroxide (PDDTBN), which partitions in the lipid and water phase of liposomes, showing all the three resonances from each phase well resolved

  1. A Doppler-broadening facility for positron spin relaxation (e+SR) experiments

    A set-up is described for the determination of the spin polarization of positrons emitted from radioactive sources that makes use of the dependence of the Doppler broadening of the 511 keV annihilation photon line on the strength and direction (with regard to the spin polarization) of an applied magnetic field. In the so-called e+SR (positron spin relaxation) technique the sample to be investigated is part of the e+-spin polarimeter. Its application to the investigation of positronium formation in condensed matter is illustrated using crystalline quartz as an example. The method earlier applied to the positron annihilation in magnetized ferromagnets is now transferred to the detection of positronium (Ps) in condensed matter. This new approach makes use of the fact, that the ratio of Ps atoms in the singlet and the triplet states is larger in a magnetic field applied parallel to the positron-spin polarization than in an antiparallel field

  2. ESR spin trapping for characterization of radical formation in Lactobacillus acidophilus NCFM and Listeria innocua.

    Hougaard, Anni B; Arneborg, Nils; Andersen, Mogens L; Skibsted, Leif H

    2013-09-01

    In this study, radicals in pure cultures of Lactobacillus acidophilus NCFM and Listeria innocua were detected in a quantitative way by electron spin resonance spectroscopy using spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) or N-tert-butyl-α-phenylnitrone (PBN). No adverse effect of spin trap addition on viability was observed for any of the bacterial strains. L. acidophilus NCFM had a higher production of radicals than L. innocua when incubated in a growth medium. Furthermore, by using DMPO in a buffer system, the radicals produced by L. acidophilus NCFM could be identified as hydroxyl radicals. The presence of polyethylene glycol, impermeable for bacterial cells, decreased the signal intensity of the ESR spectrum of the DMPO-OH adduct in cultures of L. acidophilus NCFM and indicated quenching of hydroxyl radicals outside the bacteria. This suggests that radical production is an extracellular event for L. acidophilus NCFM. PMID:23811362

  3. Spectroscopy of defects in HPHT and CVD diamond by ESR and pulsed photo-ionization measurements

    Synthetic diamond is one of the most promising wide band-gap materials for fabrication of solar-blind photo-sensors and radiation tolerant particle detectors. However, defects introduced during crystal growth and processing, causing carrier trapping and recombination, limit the functional characteristics of devices made of this material. In order to reveal the predominant defects, pulsed photo-ionization (PPI), Fourier transform infrared (FTIR) and electron spin resonance (ESR) spectroscopic measurements have been performed on diamond samples grown by chemical vapor deposition (CVD) and high pressure-high temperature (HPHT) methods. Measured photo-activation energies have been assigned to point defects associated with nitrogen and nickel impurities as well as to their complexes involving vacancies

  4. Organ dose conversions from ESR measurements using tooth enamel of atomic bomb survivors

    Dose conversions were studied for dosimetry of atomic bomb survivors based upon electron spin resonance (ESR) measurements of tooth enamel. Previously analysed data had clarified that the tooth enamel dose could be much larger than other organ doses from a low-energy photon exposure. The radiation doses to other organs or whole-body doses, however, are assumed to be near the tooth enamel dose for photon energies which are dominant in the leakage spectrum of the Hiroshima atomic bomb assumed in DS02. In addition, the thyroid can be a candidate for a surrogate organ in cases where the tooth enamel dose is not available in organ dosimetry. This paper also suggests the application of new Japanese voxel phantoms to derive tooth enamel doses by numerical analyses. (authors)

  5. An ESR study of irradiated poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA)

    Poly(tetrafluoroethylene-co-perfluoropropyl vinyl ether) (PFA) with 2 mol% perfluoropropyl vinyl ether (PPVE) was exposed to γ-irradiation in vacuum at both 77 K and room temperature and the ESR spectra recorded. Both the main chain, ∼CF2-C.F-CF2∼, and end chain, ∼CF2C.F2 radicals were identified at both temperatures and their thermal stabilities measured. No radicals unique to the radiolytic cleavage at the PPVE units were observed at room temperature, either due to the low concentration of the comonomer or β-scission to form a chain end radical and a non-radical species. G-values for radical formation at room temperature and 77 K were found to be 0.93 and 0.16, respectively

  6. Organ dose conversions from ESR measurements using tooth enamel of atomic bomb survivors.

    Takahashi, Fumiaki; Sato, Kaoru

    2012-03-01

    Dose conversions were studied for dosimetry of atomic bomb survivors based upon electron spin resonance (ESR) measurements of tooth enamel. Previously analysed data had clarified that the tooth enamel dose could be much larger than other organ doses from a low-energy photon exposure. The radiation doses to other organs or whole-body doses, however, are assumed to be near the tooth enamel dose for photon energies which are dominant in the leakage spectrum of the Hiroshima atomic bomb assumed in DS02. In addition, the thyroid can be a candidate for a surrogate organ in cases where the tooth enamel dose is not available in organ dosimetry. This paper also suggests the application of new Japanese voxel phantoms to derive tooth enamel doses by numerical analyses. PMID:22128360

  7. ESR spectra of the olive phenolics oleuropein and keracyanin in the solid state

    Hunter, C.R. [Monash University, Clayton, VIC (Australia). Anatomy Department; Troup, G.J.; Hutton, D.R. [Monash University, Clayton, VIC (Australia). Physics Department; Hewitt, D.J. [Monash University, Clayton, VIC (Australia). Chemistry Department; Romani, A.; Mulinacci, N.; Vincieri, F.F. [Universita degli Studi, Firenze (Italy). Dipartimento di Scienze Farmaceutiche

    1998-12-31

    Full text: Olives and extra virgin olive oil, are known to be very rich in antioxidants, most of which are phenolics, such as oleuropein, a derivative of catechol: the `catechol` ring is separated, and effectively isolated electrically from the other (6-sided) ring. The main anthocyanin in olives in keracyanin (cyanidin-3-0-rutinoside). Solid samples of these two phenolics, and of catechol, were examined by ESR using a Varian E-12 spectrometer (x-band: {approx}9.1 GHz) at room temperature. All three samples gave single unstructured lines of {approx} 10g. width with g-vales close to 2. The presence of these free radical signal shows the antioxidant action of these phenolics, even in the solid state. We believe this is first observation of free radicals in olive phenolics

  8. ESR spin elimination research on reaction of triplet state of VK3 with nucleic acid derivatives

    In order to study the reaction of triplet state of VK3 with nucleic acid derivatives, the ESR (Electron spin resonance) spin elimination has been used with 4-oxo-TEMPO as spin trap. The reactivities of 3VK3* with nucleosides, nucleotides, and models of telomeric DNA, template of telomerase RNA and its L6-P6 region have been confirmed respectively. The results show that the tendency of reaction of 3VK3* with nucleosides is Gua>Ade>Cyt>Thy, meanwhile dGMP>dAMP>dCMP> TMP for reaction of 3VK3* with deoxy-nucleotides, and the one for reaction of 3VK3* with telomeric DNA is the highest in polynucleotides. This is highly accordant with both of their corresponding rate constants determined by laser flash photolysis and their oxidation-reduction potentials. It also shows that the reactivity of 3VK3* with polynucleotides is directly proportional to their G amount. (authors)

  9. ESR of vanadyl ions in Mg(H2O)6H2EDTA single crystals

    Narayana, M.

    1980-04-01

    An ESR study of single crystals of Mg(H2O)6H2EDTA doped with very small concentrations of vanadyl ions showed the spectra and spin-Hamiltonian parameters to be totally different from those obtained in an earlier study with higher concentrations of VO2+. The results obtained in the present study are comparable with the data of VO(H2O)52+ in other hydrated salts like alums, etc. In low concentrations, VO2+ takes up two preferred orientations along Mg-Ow1 and Mg-Ow2 in the host octahedron. The hyperfine splitting is slightly less than that in other hydrated salts, most probably due to the strong hydrogen bonding involving the metal-water octahedra in Mg(H2O)6H2EDTA.

  10. ESR dating of late Cenozoic molassic deposits in the Jiuxi Basin

    史正涛; 业渝光; 赵志军; 方小敏; 李吉均

    2001-01-01

    In the Hexi Corridor, foreland depression at the north periphery of the Tibetan Plateau, late Cenozoic sediments can be divided into the lacustrine to deltaic Red Bed. The unconformably overlying coarse fan-conglomerate was shed from the northern plateau. This remarkable alternation of sedimentary environment and discontinuity reflect intensive rise of the plateau. Moreover, this suite of coarse molasses is divided into two formations as the Yumen conglomerate and the Jiuquan Gravel by another angular discontinuity. Tentatively, we applied ESR dating on this suite of molassic deposits at the Laojunmiao Section in the Jiuxi Basin, west of the Hexi Corridor, which shows that the bottom of the Yumen conglomerate and the Jiuquan Gravel are about 3.4 and 0.9 Ma respectively, indicating that the northern plateau at least experienced two intensive tectonic movements at about 3.5 and 0.9 Ma.

  11. The use of sugar pellets in ESR [electron spin resonance] dosimetry

    Table sugar (sucrose) is a convenient, common, tissue-equivalent material suitable for electron spin resonance (ESR) dosimetry of ionising radiation. The simple free radical signal in irradiated sugar is stabilised if the sugar is made into pellets using an inert silicone elastomer (Dow Corning 732). Such pellets, which offer greater convenience and signal stability and reproducibility, have been prepared and tested for their radiation response, sensitivity and post-irradiation stability. Irradiated sugar is detectable at ≥0.1 Gy, the signal intensity is linear with dose, and the fading of the signal, post-irradiation, is minimal for samples kept under ambient conditions. These pellets themselves, given sufficient post-irradiation signal stability, may be useful for environmental monitoring to determine long-term exposures in remote areas or at strategic locations. (Author)

  12. ESR dating of elephant teeth and radiation dose rate estimation in soil

    Chemical analysis of 238U, 232Th and 40K in the dentine as well as enamel of elephant tooth fossil has been carried out in order to estimate the internal absorbed dose rate of the specimens, which was estimated to be (39±4) mrad/y on the assumption of early uptake model of radionuclides. The external radiation dose rate in the soil including the contribution from cosmic rays was also estimated to be (175±18) mrad/y with the help of γ-ray spectroscopic techniques of the soil samples in which the specimens were buried. The 60Co γ-ray equivalent accumulated dose of (2±0.2) x 104 rad for the tooth enamel gave ''ESR age'' of (9±2) x 104 y, which falls in the geologically estimated range between 3 x 104 and 30 x 104 y before the present. (author)

  13. Detection of prior irradiation in dried fruits by electron spin resonance (ESR)

    Complete text of publication follows. Dried almonds, raisins, dates and pistachio were irradiated using gamma radiation and electron beam with an average absorbed dose of 5 kGy. The radiation treatment was detected by ESR spectroscopy. Different parts of the dried fruits were analysed as follows: almonds: skin; raisins: dried pulp (at 30 deg C for one week); dates: dried pulp (at 30 deg C for one week) and stone; pistachio: nutshell. A Bruker ECS 106 EPR Spectrometer, at a microwave power of 0.4 mW, at room temperature was used. The analysis were carried out 2-3 months and 6 months after irradiation. A series of signals, tentatively described as 'cellulose-like', 'sugar-like' and 'complex' were observed, and some slight differences between spectra recorded from samples irradiated with gamma and electrons were evident

  14. Identification and dose determination using ESR measurements in the flesh of irradiated vegetable products

    The international commerce of vegetable products is often dependent on the quarantine protections that are imposed by the importing countries because of the fear of contamination by fruit flies. The use of ionizing radiation as a treatment for these products can be used to remove this problem and a real proof of irradiation can contribute to the implementation of the international commerce. ESR measurement on the pulp of vegetable products can be used as a proof of irradiation using the species introduced in cellulose that are found uniquely in irradiated products. The stability of these species are compatible with the life of the products analyzed. The pulp signal intensity is sufficient to identify products irradiated with doses as low as 100 Gy for some fruits

  15. Spectroscopy of defects in HPHT and CVD diamond by ESR and pulsed photo-ionization measurements

    Gaubas, E.; Ceponis, T.; Meskauskaite, D.; Grigonis, R.; Sirutkaitis, V.

    2016-01-01

    Synthetic diamond is one of the most promising wide band-gap materials for fabrication of solar-blind photo-sensors and radiation tolerant particle detectors. However, defects introduced during crystal growth and processing, causing carrier trapping and recombination, limit the functional characteristics of devices made of this material. In order to reveal the predominant defects, pulsed photo-ionization (PPI), Fourier transform infrared (FTIR) and electron spin resonance (ESR) spectroscopic measurements have been performed on diamond samples grown by chemical vapor deposition (CVD) and high pressure-high temperature (HPHT) methods. Measured photo-activation energies have been assigned to point defects associated with nitrogen and nickel impurities as well as to their complexes involving vacancies.

  16. Dosimetry of electron and gamma radiation with alanine/ESR spectroscopy

    A new method for the preparation of alanine dosimeters was investigated. The absorbed dose response of these dosimeters was demonstrated for 10 MeV electron and 60Co gamma radiation in the range from 20 Gy to 1.1 kGy. Concentration of the irradiation-induced free radicals in the alanine was determined by ESR spectroscopy. In addition to measurements at ambient temperature, the alanine dosimeters were also subjected to thermal treatment during irradiation (up to about 50 deg. C) in order to assess their performance characteristics under extreme conditions which might arise in future technical applications. The results show that under normal conditions the alanine calibration curves are linear, whereas at higher temperatures the dosimeters require a correction of 0.3%/K for absorbed doses above 200 Gy. (author)

  17. ESR/L-alanine system as a proposed standard dosimeter for electron-beam irradiations

    The ESR/L-alanine system is a promising dosimeter, as it is characterized by high precision, stable dosimetric response, low value of G(freeradical) and non-toxicity. The scattering and absorption of γ radiation and fast electrons are equivalent for the system, for soft biological tissues, and for water. The possibility of further standardizations of the alanine dosimeter has now been proposed, not only as previously for γ radiation, but also for high-energy electron beam processing which brings high dose rates and side-effect problems. On the basis of the experimental results it seems reasonable to propose a new and more precise approximation of the functional shape describing the response of the L-alanine dosimeter and to express it directly by the radiation chemical yield of free radicals. (author)

  18. ESR/L-alanine system as a proposed standard dosimeter for electron-beam irradiations

    Panta, P.P.; Strzelczak-Burlinska, G.; Tomasinski, Z. (Institute of Nuclear Chemistry and Technology, Warsaw (Poland))

    1989-01-01

    The ESR/L-alanine system is a promising dosimeter, as it is characterized by high precision, stable dosimetric response, low value of G{sub (free} {sub radical)} and non-toxicity. The scattering and absorption of {gamma} radiation and fast electrons are equivalent for the system, for soft biological tissues, and for water. The possibility of further standardizations of the alanine dosimeter has now been proposed, not only as previously for {gamma} radiation, but also for high-energy electron beam processing which brings high dose rates and side-effect problems. On the basis of the experimental results it seems reasonable to propose a new and more precise approximation of the functional shape describing the response of the L-alanine dosimeter and to express it directly by the radiation chemical yield of free radicals. (author).

  19. Alanine in high-dose dosimetry: spectrophotometric and electrochemical readout procedures compared with ESR

    Van Laere, K.; Buysse, J.; Berkvens, P. (Ghent Rijksuniversiteit (Belgium). Lab. voor Kernfysica)

    1989-01-01

    The ESR readout of radical concentrations produced upon irradiation of {alpha}-alanine is compared and related to other physico-chemical detection methods. Dissolution of the free radicals in an acid ferrous sulphate solution leads to an indirect oxidation of ferrous ions. After complex formation with the dye xylenol orange optical absorption measurements can be made within a dose range from 0.03 to 12 kGy. The yield of ammonia, produced upon dissolution in a basic aqueous solution, provides spectrophotometric evaluations after complex formation with a mercury iodide containing reagent for the dose range 5 kGy to 1 MGy. A practical new routine dosimeter for applications in the range 300 Gy to at least 1 MGy, by means of an ion-selective ammonia electrode, is proposed. (author).

  20. Spin Dynamics in Graphene and Graphene like Nanocarbon Doped with Nitrogen the ESR Analysis

    Alegaonkar, Ashwini P; Pardeshi, Satish K; Alegaonkar, Prashant S

    2013-01-01

    Nano engineered spin degree of freedom in carbon system may offer desired exchange coupling with optimum spin orbit interaction which is essential, to construct solid state qubits, for fault tolerant quantum computation. The purpose of this communication is to analyze spin dynamics of, basically, four types of systems, (i) Graphene (system with inversion symmetry), (ii) Graphene like nanocarbons (GNCs, broken inversion symmetry and heterostructure, sp2 and sp3, environment), and (iii) their nitrogen doped derivatives. The spin transport data was obtained using the electron spin resonance spectroscopy (ESR) technique, carried out over 123 to 473K temperature range. Analysis of shape, linewidths of dispersion derivatives,, and g factor anisotropy has been carried out. Spin parameters such as, spin spin relaxation time, spin lattice relaxation time, spin flip parameter,spin relaxation rate,spin, momentum relaxation rate,pseudo chemical potential, density of states, effective magnetic moment, spin concentration, ...

  1. ESR spectra of the olive phenolics oleuropein and keracyanin in the solid state

    Full text: Olives and extra virgin olive oil, are known to be very rich in antioxidants, most of which are phenolics, such as oleuropein, a derivative of catechol: the 'catechol' ring is separated, and effectively isolated electrically from the other (6-sided) ring. The main anthocyanin in olives in keracyanin (cyanidin-3-0-rutinoside). Solid samples of these two phenolics, and of catechol, were examined by ESR using a Varian E-12 spectrometer (x-band: ∼9.1 GHz) at room temperature. All three samples gave single unstructured lines of ∼ 10g. width with g-vales close to 2. The presence of these free radical signal shows the antioxidant action of these phenolics, even in the solid state. We believe this is first observation of free radicals in olive phenolics

  2. Characterization of the pre-dose effect using ESR and TL

    We have used Electron Spin Resonance (ESR), Thermoluminescence (TL) and Infra-Red Absorption Spectroscopy (IR) to monitor a variety of defects, in samples of both synthetic and natural, crystalline quartz, as a function of various annealing and sweeping treatments. We have attempted to establish correlations between the various defects and the production of TL in this material in the region of 1000C. This TL peak is known as the Pre-dose peak because of its property of increasing in size following combined irradiation and annealing treatments. The data presented in this work demonstrate the involvement of the (AlO4) (o) center and suggest that H (probably in the form of H+ ions) is also intimately involved in the TL production process. (author)

  3. ESR analysis of free radicals in a (solid) green tea phenolic extract

    Full text: A solid extract of procyanidins from green tea was studied by ESR, using a Varian E-12 (X-band: ∼9.1 GHz) spectrometer, at room temperature, and liquid N2 temperature. The spectrum consisted of three unstructured lines, one ∼20 gauss wide, one ∼ 10 gauss wide, and one ∼3 gauss wide. Saturation behaviour of these lines at room and liquid N2 temperature showed them to be from different radicals. About 50% of the extract is epogallocatechin gallate (EGCG). Using a pure sample of EGCG, it was possible to assign the broadest and strongest 'single' signal to EGCG. It has not been possible yet to assign the other lines to other molecular species

  4. Evaluating the accuracy of ESR dose determination of pseudo-Early Pleistocene fossil tooth enamel samples using dose recovery tests

    In ESR dating of Early Pleistocene fossil tooth enamel samples, the fitting function used for the evaluation of the DE value is undoubtedly among the major sources of uncertainty. Dose recovery tests performed on fossil tooth enamel showing DE values >1,000 Gy demonstrate: (i) that high precision ESR measurements (<0.5%) and high DE reproducibility (<5%) may be achieved; (ii) the appropriateness of the Double Saturating Exponential (DSE) fitting function for ESR dose reconstruction. In contrast, the SSE function, which has been almost exclusively used so far, does simply not correctly describe the behavior of the radiation induced ESR signal of tooth enamel with the dose. Several fitting functions and data weighting options were tested and the combination of a DSE with data weighted by the inverse of the squared intensities is the procedure providing the most accurate DE results. However, the SSE may nevertheless sometimes produce consistent results if Dmax does not exceed 6*DE. Further work is required in that direction in order to determine more precisely in which conditions the SSE could be used as a fair approximation of the DSE function for these samples. - Highlights: • Dose recovery tests performed on fossil tooth enamel with DE values >1,000 Gy. • Several fitting functions were used. • The SSE function does not correctly describe the behavior of the ESR signal. • The most accurate DE results are obtained by using a DSE with data weighted by 1/I2. • The SSE might nevertheless produce fairly consistent results under certain conditions

  5. ESR investigation of radicals formed in γ-irradiated vinylidene fluoride based copolymer: P(VDF-co-HFP)

    Samples of copolymer based on vinylidene fluoride and hexafluoropropene P(VDF-co-HFP) were exposed to γ-radiation performed under an inert atmosphere and the total amount of radicals was quantified by electron spin resonance spectroscopy (ESR). An in-depth study of recorded ESR spectra allowed the identification of several types of radical species formed during radiolysis. Starting from an ESR simulation model established for irradiated PVDF, seven radical species have been identified in the case of P(VDF-co-HFP): five of them are related to the VDF units while the two others are derived from the HFP unit. The model used to simulate the complex superimposed ESR signals is presented. The proportions of each species are discussed and correlated to the amount of HFP units contained in the copolymer, and to the stability of each species depending on their local environment. Furthermore, the evolution of radical density with radiation dose and the decay resulting from annealing at a given temperature are presented. Corresponding spectral evolution shows the progressive predominance of most stable species. - Highlights: ► ESR signal of γ-irradiated P(vinylidene fluoride-co-hexafluoropropene) containing 6 wt% of hexafluoropropene is modeled. ► The formation of seven major radical species is proposed for the first time. ► Despite a low comonomer content, 43% of radicals are localized on hexafluoropropene. ► Effect of dose and annealing highlight radical stability. ► Radical stability is found to depend on both chemical environment and chain location

  6. Gain-of-function phenotypes of many CLAVATA3/ESR genes, including four new family members, correlate with tandem variations in the conserved CLAVATA3/ESR domain.

    Strabala, Timothy J; O'donnell, Philip J; Smit, Anne-Marie; Ampomah-Dwamena, Charles; Martin, E Jane; Netzler, Natalie; Nieuwenhuizen, Niels J; Quinn, Brian D; Foote, Humphrey C C; Hudson, Keith R

    2006-04-01

    Secreted peptide ligands are known to play key roles in the regulation of plant growth, development, and environmental responses. However, phenotypes for surprisingly few such genes have been identified via loss-of-function mutant screens. To begin to understand the processes regulated by the CLAVATA3 (CLV3)/ESR (CLE) ligand gene family, we took a systems approach to gene identification and gain-of-function phenotype screens in transgenic plants. We identified four new CLE family members in the Arabidopsis (Arabidopsis thaliana) genome sequence and determined their relative transcript levels in various organs. Overexpression of CLV3 and the 17 CLE genes we tested resulted in premature mortality and/or developmental timing delays in transgenic Arabidopsis plants. Overexpression of 10 CLE genes and the CLV3 positive control resulted in arrest of growth from the shoot apical meristem (SAM). Overexpression of nearly all the CLE genes and CLV3 resulted in either inhibition or stimulation of root growth. CLE4 expression reversed the SAM proliferation phenotype of a clv3 mutant to one of SAM arrest. Dwarf plants resulted from overexpression of five CLE genes. Overexpression of new family members CLE42 and CLE44 resulted in distinctive shrub-like dwarf plants lacking apical dominance. Our results indicate the capacity for functional redundancy of many of the CLE ligands. Additionally, overexpression phenotypes of various CLE family members suggest roles in organ size regulation, apical dominance, and root growth. Similarities among overexpression phenotypes of many CLE genes correlate with similarities in their CLE domain sequences, suggesting that the CLE domain is responsible for interaction with cognate receptors. PMID:16489133

  7. An improved method for detection of Edwardsiella tarda by loop-mediated isothermal amplification by targeting the EsrB gene

    XIE Guosi; ZHANG Qingli; HAN Nana; SHI Chengyin; WANG Xiuhua; LIU Qinghui; HUANG Jie

    2012-01-01

    Edwardsiella tarda is a major pathogen in aquatic environments that can cause heavy economic losses.An improved method for quick and accurate detection of E.tarda by loop-mediated isothermal amplification (LAMP) with two additional loop primers was developed by targeting the EsrB gene (EsrBLAMP).In this method,the Mg2+ concentration,reaction temperature,and reaction time were optimized to 8 mmol/L,61℃,and 40 min,respectively.The detection limit with the EsrB gene was as low as 10 copies,which is 100 times more sensitive than that of conventional polymerase chain reaction (PCR).The EsrB-LAMP assay was shown more sensitive and rapid than previously reported LAMP assays targeting the hemolysin gene (hemolysin-LAMP) for detection ofE.tarda.The EsrB-LAMP was also highly specific to E.tarda and had no cross-reaction with 13 other strains of bacteria.The assay can be carried out in a simple heating device and the EsrB-LAMP products can be visually detected by adding fluorescent dye to the reaction mixture.Taken together,the improved EsrB-LAMP diagnostic protocol has the potential for detection ofE.tarda from indoor and outdoor samples.

  8. Flat acoustic lens by acoustic grating with curled slits

    Peng, Pai

    2014-10-01

    We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry-Perot resonance.

  9. ESR phase competition study of Pr0.5(Ca0.85Sr0.15)0.5MnO3

    We report an electron spin resonance (ESR) study of the competing phases at the crossover from localized to itinerant behaviour on the polycrystalline Pr0.5(Ca0.85Sr0.15)0.5MnO3 compounds. From the temperature dependence of the ESR intensity, we derived the transition temperatures to charge order (TCO=230 K), and antiferromagnetic (TN=150 K) states. In addition, at T<200 K, a ferromagnetic minority phase was found, that coexists with the paramagnetic and antiferromagnetic phases. We perform simulations of the ESR spectra that reproduce the behaviour found at different temperatures

  10. ESR analyses for teeth from the open-air site at Attirampakkam, India: Clues to complex U uptake and paleoenvironmental change

    In open-air sites, diagenetic alteration makes teeth difficult to analyze with electron spin resonance (ESR). Despite strong diagenetic alteration, three ungulate teeth from Pleistocene fluvial sediment in the open-air Paleolithic site at Attirampakkam, Tamil Nadu, India, were analyzed using standard and isochron ESR. Diagenetic alteration features in two teeth indicated rapid submergence in quiet saline to hypersaline water, following a short subaerial exposure, while the third remained constantly buried under reducing conditions. Geochemical signatures and ESR data all indicate that the teeth experienced at least three independent U uptake events during diagenesis, including two that occurred long after burial

  11. Acoustics Discipline Overview

    Envia, Edmane; Thomas, Russell

    2007-01-01

    As part of the Fundamental Aeronautics Program Annual Review, a summary of the progress made in 2007 in acoustics research under the Subsonic Fixed Wing project is given. The presentation describes highlights from in-house and external activities including partnerships and NRA-funded research with industry and academia. Brief progress reports from all acoustics Phase 1 NRAs are also included as are outlines of the planned activities for 2008 and all Phase 2 NRAs. N+1 and N+2 technology paths outlined for Subsonic Fixed Wing noise targets. NRA Round 1 progressing with focus on prediction method advancement. NRA Round 2 initiating work focused on N+2 technology, prediction methods, and validation. Excellent partnerships in progress supporting N+1 technology targets and providing key data sets.

  12. Acoustic methodology review

    Schlegel, R. G.

    1982-01-01

    It is important for industry and NASA to assess the status of acoustic design technology for predicting and controlling helicopter external noise in order for a meaningful research program to be formulated which will address this problem. The prediction methodologies available to the designer and the acoustic engineer are three-fold. First is what has been described as a first principle analysis. This analysis approach attempts to remove any empiricism from the analysis process and deals with a theoretical mechanism approach to predicting the noise. The second approach attempts to combine first principle methodology (when available) with empirical data to formulate source predictors which can be combined to predict vehicle levels. The third is an empirical analysis, which attempts to generalize measured trends into a vehicle noise prediction method. This paper will briefly address each.

  13. Acoustic Tractor Beam

    Démoré, Christine E. M.; Dahl, Patrick M.; Yang, Zhengyi; Glynne-Jones, Peter; Melzer, Andreas; Cochran, Sandy; MacDonald, Michael P.; Spalding, Gabriel C.

    2014-05-01

    Negative radiation forces act opposite to the direction of propagation, or net momentum, of a beam but have previously been challenging to definitively demonstrate. We report an experimental acoustic tractor beam generated by an ultrasonic array operating on macroscopic targets (>1 cm) to demonstrate the negative radiation forces and to map out regimes over which they dominate, which we compare to simulations. The result and the geometrically simple configuration show that the effect is due to nonconservative forces, produced by redirection of a momentum flux from the angled sides of a target and not by conservative forces from a potential energy gradient. Use of a simple acoustic setup provides an easily understood illustration of the negative radiation pressure concept for tractor beams and demonstrates continuous attraction towards the source, against a net momentum flux in the system.

  14. Acoustic classification of dwellings

    Berardi, Umberto; Rasmussen, Birgit

    2014-01-01

    Schemes for the classification of dwellings according to different building performances have been proposed in the last years worldwide. The general idea behind these schemes relates to the positive impact a higher label, and thus a better performance, should have. In particular, focusing on sound...... insulation performance, national schemes for sound classification of dwellings have been developed in several European countries. These schemes define acoustic classes according to different levels of sound insulation. Due to the lack of coordination among countries, a significant diversity in terms of...... descriptors, number of classes, and class intervals occurred between national schemes. However, a proposal “acoustic classification scheme for dwellings” has been developed recently in the European COST Action TU0901 with 32 member countries. This proposal has been accepted as an ISO work item. This paper...

  15. Acoustic emission source modeling

    Hora P.

    2010-07-01

    Full Text Available The paper deals with the acoustic emission (AE source modeling by means of FEM system COMSOL Multiphysics. The following types of sources are used: the spatially concentrated force and the double forces (dipole. The pulse excitation is studied in both cases. As a material is used steel. The computed displacements are compared with the exact analytical solution of point sources under consideration.

  16. The acoustics of snoring.

    Pevernagie, Dirk; Aarts, Ronald M; De Meyer, Micheline

    2010-04-01

    Snoring is a prevalent disorder affecting 20-40% of the general population. The mechanism of snoring is vibration of anatomical structures in the pharyngeal airway. Flutter of the soft palate accounts for the harsh aspect of the snoring sound. Natural or drug-induced sleep is required for its appearance. Snoring is subject to many influences such as body position, sleep stage, route of breathing and the presence or absence of sleep-disordered breathing. Its presentation may be variable within or between nights. While snoring is generally perceived as a social nuisance, rating of its noisiness is subjective and, therefore, inconsistent. Objective assessment of snoring is important to evaluate the effect of treatment interventions. Moreover, snoring carries information relating to the site and degree of obstruction of the upper airway. If evidence for monolevel snoring at the site of the soft palate is provided, the patient may benefit from palatal surgery. These considerations have inspired researchers to scrutinize the acoustic characteristics of snoring events. Similarly to speech, snoring is produced in the vocal tract. Because of this analogy, existing techniques for speech analysis have been applied to evaluate snoring sounds. It appears that the pitch of the snoring sound is in the low-frequency range (noise-like', and has scattered energy content in the higher spectral sub-bands (>500 Hz). To evaluate acoustic properties of snoring, sleep nasendoscopy is often performed. Recent evidence suggests that the acoustic quality of snoring is markedly different in drug-induced sleep as compared with natural sleep. Most often, palatal surgery alters sound characteristics of snoring, but is no cure for this disorder. It is uncertain whether the perceived improvement after palatal surgery, as judged by the bed partner, is due to an altered sound spectrum. Whether some acoustic aspects of snoring, such as changes in pitch, have predictive value for the presence of

  17. Acoustically enhanced heat transport

    Ang, Kar M.; Hung, Yew Mun; Tan, Ming K., E-mail: tan.ming.kwang@monash.edu [School of Engineering, Monash University Malaysia, 47500 Bandar Sunway, Selangor (Malaysia); Yeo, Leslie Y. [Micro/Nanophysics Research Laboratory, RMIT University, Melbourne, VIC 3001 (Australia); Friend, James R. [Department of Mechanical and Aerospace Engineering, University of California, San Diego, California 92093 (United States)

    2016-01-15

    We investigate the enhancement of heat transfer in the nucleate boiling regime by inducing high frequency acoustic waves (f ∼ 10{sup 6} Hz) on the heated surface. In the experiments, liquid droplets (deionized water) are dispensed directly onto a heated, vibrating substrate. At lower vibration amplitudes (ξ{sub s} ∼ 10{sup −9} m), the improved heat transfer is mainly due to the detachment of vapor bubbles from the heated surface and the induced thermal mixing. Upon increasing the vibration amplitude (ξ{sub s} ∼ 10{sup −8} m), the heat transfer becomes more substantial due to the rapid bursting of vapor bubbles happening at the liquid-air interface as a consequence of capillary waves travelling in the thin liquid film between the vapor bubble and the air. Further increases then lead to rapid atomization that continues to enhance the heat transfer. An acoustic wave displacement amplitude on the order of 10{sup −8} m with 10{sup 6} Hz order frequencies is observed to produce an improvement of up to 50% reduction in the surface temperature over the case without acoustic excitation.

  18. High-Frequency Seafloor Acoustics

    Jackson, Darrell R

    2007-01-01

    High-Frequency Seafloor Acoustics is the first book in a new series sponsored by the Office of Naval Research on the latest research in underwater acoustics. This exciting new title provides ready access to experimental data, theory, and models relevant to high-frequency seafloor acoustics and will be of interest to sonar engineers and researchers working in underwater acoustics. The physical characteristics of the seafloor affecting acoustic propagation and scattering are covered, including physical and geoacoustic properties and surface roughness. Current theories for acoustic propagation in sediments are presented along with corresponding models for reflection, scattering, and seafloor penetration. The main text is backed up by an extensive bibliography and technical appendices.

  19. Fundamentals of Shallow Water Acoustics

    Katsnelson, Boris; Lynch, James

    2012-01-01

    Shallow water acoustics (SWA), the study of how low and medium frequency sound propagates and scatters on the continental shelves of the world's oceans, has both technical interest and a large number of practical applications. Technically, shallow water poses an interesting medium for the study of acoustic scattering, inverse theory, and propagation physics in a complicated oceanic waveguide. Practically, shallow water acoustics has interest for geophysical exploration, marine mammal studies, and naval applications. Additionally, one notes the very interdisciplinary nature of shallow water acoustics, including acoustical physics, physical oceanography, marine geology, and marine biology. In this specialized volume, the authors, all of whom have extensive at-sea experience in U.S. and Russian research efforts, have tried to summarize the main experimental, theoretical, and computational results in shallow water acoustics, with an emphasis on providing physical insight into the topics presented.

  20. Latest Trends in Acoustic Sensing

    Cinzia Caliendo

    2014-03-01

    Full Text Available Acoustics-based methods offer a powerful tool for sensing applications. Acoustic sensors can be applied in many fields ranging from materials characterization, structural health monitoring, acoustic imaging, defect characterization, etc., to name just a few. A proper selection of the acoustic wave frequency over a wide spectrum that extends from infrasound (<20 Hz up to ultrasound (in the GHz–band, together with a number of different propagating modes, including bulk longitudinal and shear waves, surface waves, plate modes, etc., allow acoustic tools to be successfully applied to the characterization of gaseous, solid and liquid environments. The purpose of this special issue is to provide an overview of the research trends in acoustic wave sensing through some cases that are representative of specific applications in different sensing fields.

  1. Wireless Acoustic Measurement System

    Anderson, Paul D.; Dorland, Wade D.; Jolly, Ronald L.

    2007-01-01

    A prototype wireless acoustic measurement system (WAMS) is one of two main subsystems of the Acoustic Prediction/ Measurement Tool, which comprises software, acoustic instrumentation, and electronic hardware combined to afford integrated capabilities for predicting and measuring noise emitted by rocket and jet engines. The other main subsystem is described in the article on page 8. The WAMS includes analog acoustic measurement instrumentation and analog and digital electronic circuitry combined with computer wireless local-area networking to enable (1) measurement of sound-pressure levels at multiple locations in the sound field of an engine under test and (2) recording and processing of the measurement data. At each field location, the measurements are taken by a portable unit, denoted a field station. There are ten field stations, each of which can take two channels of measurements. Each field station is equipped with two instrumentation microphones, a micro- ATX computer, a wireless network adapter, an environmental enclosure, a directional radio antenna, and a battery power supply. The environmental enclosure shields the computer from weather and from extreme acoustically induced vibrations. The power supply is based on a marine-service lead-acid storage battery that has enough capacity to support operation for as long as 10 hours. A desktop computer serves as a control server for the WAMS. The server is connected to a wireless router for communication with the field stations via a wireless local-area network that complies with wireless-network standard 802.11b of the Institute of Electrical and Electronics Engineers. The router and the wireless network adapters are controlled by use of Linux-compatible driver software. The server runs custom Linux software for synchronizing the recording of measurement data in the field stations. The software includes a module that provides an intuitive graphical user interface through which an operator at the control server

  2. Magneto-photo-acoustic imaging

    Qu, Min; Mallidi, Srivalleesha; Mehrmohammadi, Mohammad; Truby, Ryan; Homan, Kimberly; Joshi, Pratixa; Chen, Yun-Sheng; Sokolov, Konstantin; Emelianov, Stanislav

    2011-01-01

    Magneto-photo-acoustic imaging, a technique based on the synergy of magneto-motive ultrasound, photoacoustic and ultrasound imaging, is introduced. Hybrid nanoconstructs, liposomes encapsulating gold nanorods and iron oxide nanoparticles, were used as a dual-contrast agent for magneto-photo-acoustic imaging. Tissue-mimicking phantom and macrophage cells embedded in ex vivo porcine tissue were used to demonstrate that magneto-photo-acoustic imaging is capable of visualizing the location of cel...

  3. Room acoustic auralization with Ambisonics

    Polack, Jean-Dominique; Leão Figueiredo, Fábio

    2012-01-01

    International audience During the year of 2009, the room acoustics group of the LAM (Équipe Lutheries, Acoustique, Musique de l’Institut Jean Le Rond d’Alembert - Université Pierre et Marie Curie, Paris) performed a series of acoustical measurements in music halls in Paris. The halls were chosen in regarding their importance to the historic, architectural or acoustic domains. The measured ensemble of fourteen rooms includes quite different architectural designs. The measurements were carri...

  4. Combined Environment Acoustic Chamber (CEAC)

    Federal Laboratory Consortium — Purpose: The CEAC imposes combined acoustic, thermal and mechanical loads on aerospace structures. The CEAC is employed to measure structural response and determine...

  5. Truck acoustic data analyzer system

    Haynes, Howard D.; Akerman, Alfred; Ayers, Curtis W.

    2006-07-04

    A passive vehicle acoustic data analyzer system having at least one microphone disposed in the acoustic field of a moving vehicle and a computer in electronic communication the microphone(s). The computer detects and measures the frequency shift in the acoustic signature emitted by the vehicle as it approaches and passes the microphone(s). The acoustic signature of a truck driving by a microphone can provide enough information to estimate the truck speed in miles-per-hour (mph), engine speed in rotations-per-minute (RPM), turbocharger speed in RPM, and vehicle weight.

  6. Irradiation dose control of chicken meat processing with alanine/ESR dosimetric system

    Irradiation of foodstuff is a well-known food preservation technique. In Brazil spices are already irradiated for sanitary and preservation reasons. Chicken meat is an important commodity; Brazil is the second largest world producer and the largest world exporter. The shelf-life of chicken meat is limited by the presence of micro-organisms and enzyme activity and together with other preservation techniques irradiation seems to be an attractive option. In this study the dose delivered to frozen chicken cuts was measured and compared with the prescribed value. Chicken breast cuts were analyzed for 39 days for their microbiological activity, chemical and organoleptic properties. Cylindrical dosimeters were prepared using the weight composition of 80% of DL-alanine (Sigma Co), used without any further treatment except drying, and 20% of paraffin. The dosimeters having 4.7 mm diameter and 12 mm length were inserted in a build-up cap. Dosimeters were placed inside cardboard boxes containing frozen chicken breast cuts, packed in styrofoam trays wrapped with plastic film. The boxes were irradiated in an industrial 60Co irradiator (Nordion JS 7500) with a dose rate of 4 kGy/h. First derivative ESR signals were obtained in a VARIAN E-4 spectrometer operating at X-band (ν∼9GHz) and equipped with a rectangular cavity (TE-102, model E-231). The cavity was constantly purged with dry nitrogen and modulated at 100 KHz with 0.5 mT peak to peak. A calibration curve was made for a few dosimeters from the same batch and used to obtain the dose from the ESR signal intensity. A batch of six boxes was irradiated at each experiment with prescribed doses of 1.5, 3.0 and 7.0 kGy. Considering that the larger the radiation dose the greater is the probability of finding a product with its sensorial characteristics altered (odor of burned meat), we conclude that a dose of 3 kGy would be more adequate, taking into account the microbiological and sensorial aspects

  7. Irradiation dose control of chicken meat processing with alanine/ESR dosimetric system

    Miyagusku, L. [Centro de Tecnologia de Carnes, Instituto de Tecnologia de Alimentos. Av. Brasil, 2880 13074-001 Campinas, SP (Brazil); Chen, F. [Departmento de Fisica e Matematica, FFCLRP - Universidade de Sao Paulo, 14040-901, Ribeirao Preto - SP (Brazil); Kuaye, A. [Departamento de Tecnologia de Alimentos, Universidade de Campinas, Campinas - SP (Brazil); Castilho, C.J.C. [Departamento de Agroindustria, ESALQ, Piracicaba - SP (Brazil); Baffa, O. [Departmento de Fisica e Matematica, FFCLRP - Universidade de Sao Paulo, 14040-901, Ribeirao Preto - SP (Brazil)], E-mail: baffa@ffclrp.usp.br

    2007-07-15

    Irradiation of foodstuff is a well-known food preservation technique. In Brazil spices are already irradiated for sanitary and preservation reasons. Chicken meat is an important commodity; Brazil is the second largest world producer and the largest world exporter. The shelf-life of chicken meat is limited by the presence of micro-organisms and enzyme activity and together with other preservation techniques irradiation seems to be an attractive option. In this study the dose delivered to frozen chicken cuts was measured and compared with the prescribed value. Chicken breast cuts were analyzed for 39 days for their microbiological activity, chemical and organoleptic properties. Cylindrical dosimeters were prepared using the weight composition of 80% of DL-alanine (Sigma Co), used without any further treatment except drying, and 20% of paraffin. The dosimeters having 4.7 mm diameter and 12 mm length were inserted in a build-up cap. Dosimeters were placed inside cardboard boxes containing frozen chicken breast cuts, packed in styrofoam trays wrapped with plastic film. The boxes were irradiated in an industrial {sup 60}Co irradiator (Nordion JS 7500) with a dose rate of 4 kGy/h. First derivative ESR signals were obtained in a VARIAN E-4 spectrometer operating at X-band ({nu}{approx}9GHz) and equipped with a rectangular cavity (TE-102, model E-231). The cavity was constantly purged with dry nitrogen and modulated at 100 KHz with 0.5 mT peak to peak. A calibration curve was made for a few dosimeters from the same batch and used to obtain the dose from the ESR signal intensity. A batch of six boxes was irradiated at each experiment with prescribed doses of 1.5, 3.0 and 7.0 kGy. Considering that the larger the radiation dose the greater is the probability of finding a product with its sensorial characteristics altered (odor of burned meat), we conclude that a dose of 3 kGy would be more adequate, taking into account the microbiological and sensorial aspects.

  8. Esrâr Dede Divanı’nda Renkler Colours In Dıvan Of Esrâr Dede

    Mahmut KAPLAN

    2013-03-01

    Full Text Available Esrâr Dede is one of significant figures of our classical poetry. After becoming affiliated with Mevleviyeh, he embarked upon poetry, bringing forth remarkable works. He made friends with Şeyh Galib. The poet has a collection of biographies and dictionary as well as a divan. Esrar Dede frequently used words which expressed colours in order toexplain his feelings and thoughts. The words of colours are alsoimportant bearers of cultural heritage. Colours which are used indescription and definition of entities gain representative meanings insome texts (of the society, too. It is known that some colours statedirections in Turkish. At times, colours are used to express feelings;they reflect people’s mood. Colours are the most important means poetshave to depict sceneries of nature. A poet displays the nature throughwords of colour, and expresses their feelings and thoughts withinsymbolic expressions by means of colours. In depictions made in prosesof eulogiums, colours have important roles. Esrar Dede, most of whoseodes are affectionate, also applied adjectives of colour to express hisfeelings and thoughts. Black and red are especially seen aspredominant colours in Esrar Dede Divan. These colours were used todepict entities and express some sufistic situations. Black is generallyseen in the descriptions of night, hair, and darkness. Moreover, thiscolour is applied to depict situations such as bad fortune andmischance. Red is seen in depictions of rose, dawn, blood, and lips.Except these two main colours, white, yellow, green; andcolournessness and lack of colour which express sufistic situations tookplace among the colours the poet used. When it is taken into accountthat Esrar Dede was a Mevlevi, it will be understood how importantcolours are in his poetry. In this article, Esrar Dede’s perception ofcolour was tried to determine by evaluating the colours he used withintheir contexts in the text. The colours have been arranged andinvestigated in

  9. Studi Spektroskopi Electron Spin Resonance (Esr Lapisan Tipis Amorf Silikon Karbon (A-Sic:H Hasil Deposisi Metode Dc Sputtering

    Rosari Saleh

    2002-04-01

    Full Text Available The dangling bond defect density in sputtered amorphous silicon carbon alloys have been studied by electron spin resonance (ESR. The results show that the spin density decreased slightly with increasing methane fl ow rate (CH4. The infl uence of carbon and hydrogen incorporation on g-value revealed that for CH4 fl ow rate up to 8 sccm, the ESR signal is dominated by defects characteristic of a-Si:H fi lms and for CH4 fl ow rate higher than 8 sccm the g-value decreased towards those usually found in a-C:H fi lms. Infrared (IR results suggest that as CH4 fl ow rate increases more carbon and hydrogen is incorporated into the fi lms to form Si-H, Si-C and C-H bonds. A direct relation between the IR results and the defect density and g-value is observed.

  10. Acoustic transparency and slow sound using detuned acoustic resonators

    Santillan, Arturo Orozco; Bozhevolnyi, Sergey I.

    2011-01-01

    We demonstrate that the phenomenon of acoustic transparency and slowsound propagation can be realized with detuned acoustic resonators (DAR), mimicking thereby the effect of electromagnetically induced transparency (EIT) in atomic physics. Sound propagation in a pipe with a series of side...

  11. Ares I Scale Model Acoustic Test Lift-Off Acoustics

    Counter, Douglas D.; Houston, Janie D.

    2011-01-01

    The lift-off acoustic (LOA) environment is an important design factor for any launch vehicle. For the Ares I vehicle, the LOA environments were derived by scaling flight data from other launch vehicles. The Ares I LOA predicted environments are compared to the Ares I Scale Model Acoustic Test (ASMAT) preliminary results.

  12. Polimorfismo de los genes receptores de estrogenos (ESR) y prolactina (PRLR) y su asociación con prolificidad y productividad de la cerda

    Barreras Serrano, Alberto

    2012-01-01

    Los genes receptor de estrógeno (ESR) y receptor de prolactina (PRLR) fueron investigados como genes candidatos para características reproductivas. Dos localidades fueron incluidas en este estudio: Mexicali, Baja California y Navojoa, Sonora. Los genotipos para los genes ESR y PRLR fueron obtenidos de muestras sanguíneas de 136 hembras del sitio 1 (Baja California) y 300 provenientes del sitio 2 (Sonora). Los grupos genéticos utilizados fueron Yorkshire (Y), Landrace (...

  13. Combined ESR/U-series chronology of Acheulian hominid-bearing layers at Trinchera Galeria site, Atapuerca, Spain

    The Sierra de Atapuerca, northern Spain, is known from many prehistoric and paleontologic sites documenting human prehistory in Europe. Three major sites, Gran Dolina, Galeria and Sima del Elefante, range in age from the oldest hominin of Western Europe dated to 1.1 to 1.3 Ma (millions of years ago) at Sima del Elefante to c.a. 0.2 Ma on the top of the Galeria archaeological sequence. Recently, a chronology based on luminescence methods (Thermoluminescence [TL] and Infrared Stimulated Luminescence [IRSL]) applied to cave sediments was published for the Gran Dolina and Galeria sites. The authors proposed for Galeria an age of 450 ka (thousands of years ago) for the units lower GIII and GII, suggesting that the human occupation there is younger than the hominid remains of Sima de los Huesos (≥530 ka) around 1 km away. In this paper, we present new results obtained by combined Electron Spin Resonance/Uranium-series (ESR/U-series) dating on 20 herbivorous teeth from different levels at the Galeria site. They are in agreement with the TL results for the upper part of the stratigraphic sequence (GIV and GIIIb), in the range of between 200 and 250 ka. But for the GIIIa to GIIb levels, the TL ages become abruptly older by 200 ka while ESR ages remain relatively constant. Finally, the TL and ESR data agree in the lowest part of the section (GIIa); both fall in the range of around 350-450 ka. Our results suggest a different interpretation for the GII, GIII and GIV units of Galeria and the upper part of Gran Dolina (TD10 and TD11) than obtained by TL. The ESR/U-series results are supported by a Bayesian analysis, which allows a better integration between stratigraphic information and radiometric data. (authors)

  14. Estimation of radiation exposed area by the nuclear accident occurred at Tokai village using ESR measurements of household sugar

    The area of radiation exposure by the nuclear accident occurred at Tokai village in 1999 was estimated by the ESR measurement of 95 household sugar samples collected from the accident area. These samples were roughly classified into three types of sugar, fine white sugar, fine brown sugar and coarse brown sugar. The control fine white sugar showed no radical in the ESR spectrum, while those of fine brown sugar and coarse brown sugar showed the presence of a small amount of radicals. It was also shown that, among these three kinds of sugar, the radical concentration of fine white sugar sampled from wooden houses at the area similar to each other did not vary much with the samples, while those of fine brown sugar and coarse brown sugar varied to a considerable extent. Thus, the fine white sugar is considered to be more suitable for the estimation of the level of radiation exposure. The radical concentration of each fine white sugar sample was plotted against the distance from the site of the nuclear accident with a correction of the difference in the shielding effect between concrete houses and wooden houses. The samples obtained at more than 2 km north of the site of nuclear accident showed no ESR spectral signal to a detectable extent. On the other hand, the ESR spectra were observed from the samples obtained within 10 km south and 4 km west of the accident site. These results suggest that the radiation exposure by the contaminant blown by the northeast wind blowing on the day of the accident may occur at the south and west areas. (author)

  15. Association study of the estrogen receptor gene ESR1 with post-partum depression – a pilot study

    Pinsonneault, Julia K.; Sullivan, Danielle; Sadee, Wolfgang; Soares, Claudio N.; Hampson, Elizabeth; Steiner, Meir

    2013-01-01

    Perinatal mood disorders, such as postpartum depression (PPD) are costly for society, with potentially serious consequences for mother and child. While multiple genes appear to play a role in PPD susceptibility, the contributions of specific genetic variations remain unclear. Previously implicated as a candidate gene, the estrogen receptor alpha gene (ESR1) is a key player in mediating hormonal differences during pregnancy and the postpartum period. This study addresses genetic factors in per...

  16. Acoustic Mechanical Feedthroughs

    Sherrit, Stewart; Walkemeyer, Phillip; Bao, Xiaoqi; Bar-Cohen, Yoseph; Badescu, Mircea

    2013-01-01

    Electromagnetic motors can have problems when operating in extreme environments. In addition, if one needs to do mechanical work outside a structure, electrical feedthroughs are required to transport the electric power to drive the motor. In this paper, we present designs for driving rotary and linear motors by pumping stress waves across a structure or barrier. We accomplish this by designing a piezoelectric actuator on one side of the structure and a resonance structure that is matched to the piezoelectric resonance of the actuator on the other side. Typically, piezoelectric motors can be designed with high torques and lower speeds without the need for gears. One can also use other actuation materials such as electrostrictive, or magnetostrictive materials in a benign environment and transmit the power in acoustic form as a stress wave and actuate mechanisms that are external to the benign environment. This technology removes the need to perforate a structure and allows work to be done directly on the other side of a structure without the use of electrical feedthroughs, which can weaken the structure, pipe, or vessel. Acoustic energy is pumped as a stress wave at a set frequency or range of frequencies to produce rotary or linear motion in a structure. This method of transferring useful mechanical work across solid barriers by pumping acoustic energy through a resonant structure features the ability to transfer work (rotary or linear motion) across pressure or thermal barriers, or in a sterile environment, without generating contaminants. Reflectors in the wall of barriers can be designed to enhance the efficiency of the energy/power transmission. The method features the ability to produce a bi-directional driving mechanism using higher-mode resonances. There are a variety of applications where the presence of a motor is complicated by thermal or chemical environments that would be hostile to the motor components and reduce life and, in some instances, not be

  17. Electronic and ESR spectroscopic study of thiocyanate-containing coordination compounds of titanium(III) in alcohol solutions

    In an investigation of electronic and ESR spectra, it has been established that titanium(III) with the thiocyanate ion (in ethanol) forms distorted tetrahedral and octahedral complexes. The tetrahedral compounds are hydroxo complexes of titanium(III) that contain one hydroxyl group and three thiocyanate ions in the coordination sphere. In the ESR spectra of liquid solutions, additional splitting on the nitrogen atoms is manifested (A0/sup N/ = 2.2 x 10-4 cm-1), which indicates bonding of thiocyanate ions through the nitrogen atom. The pseudo-octahedral complexes of titanium(III), containing from two to six thiocyanate ions in the coordination sphere, are characterized by d-d absorption bands in the 520-590 nm region; and at 770K, they give anisotropic ESR signals. On the basis of the temperature dependences of the equilibrium constants for the reaction of conversion of the tetrahedral complexes to the octahedral complexes, and also the lifetimes of the tetrahedral complexes, values have been estimated for the heat of reaction (ΔH = 26.8 kJ/mole) and the entropy change (ΔS = -1.66 kJ/mole x 0K) of the equilibrium process, and also the activation energy for the reaction of titanium(III) thiocyanate formation (ΔE = 37 kJ/mole)

  18. Permeability studies of redox-sensitive nitroxyl spin probes in corn oil using an L-band ESR spectrometer

    Jebaraj, D. David; Utsumi, Hideo; Asath, R. Mohamed; Benial, A. Milton Franklin

    2016-05-01

    Electron spin resonance (ESR) studies were carried out for 2mM 14N labeled 2H enriched 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL) and 3-carboxy-2,2,5,5,-tetramethyl-1-pyrrolidinyloxy (carboxy-PROXYL) in pure water and various concentrations of corn oil. The ESR parameters, such as the line width, hyperfine coupling constant, g-factor, rotational correlation time, partition parameter and permeability were reported for the samples. The line width broadening was observed for both nitroxyl radicals in corn oil solutions. The partition parameter for permeable MC-PROXYL in corn oil increases with increasing concentration of corn oil, which reveals that the nitroxyl spin probe permeates into the oil phase. From the results, the corn oil concentration was optimized as 50 % for phantom studies. The rotational correlation time also increases with increasing concentration of corn oil. The permeable and impermeable nature of nitroxyl spin probes was demonstrated. These results will be useful for the development of ESR/OMR imaging modalities in in vivo and in vitro studies.

  19. Changes in ESR-spectra of the model nitrosyl complexes with blood hemoproteins after low dose irradiation of mice

    After NO adding to mice blood and isolated erythrocytes ESR signal of nitrosyl complex HbNO (g = 2.07, g =1.98) and NO-induced MetNg (g = 6.0) were registered. It was shown that the intensity of ESR spectra of these complexes increased after radiation of mice with a dose of 0.06, 0.6 and 5.4 cGy. Low-dose irradiation (0.6 and 0.06 cGy) caused the change in the form of ESR spectra of HbNO (g = 2.07), which is indicative of the shift from T-structure to R-structure and of the preferred formation of R-conformations of oxyhemoglobin in blood. It was found that dependence of NO-induced MetHB signal on irradiation dose is bimodal that may be connected with nonlinear response of the cells to irradiation and retarded adaptive response after radiation with low doses

  20. ESR studies on the thermal decomposition of trimethylamine oxide to formaldehyde and dimethylamine in jumbo squid (Dosidicus gigas) extract.

    Zhu, Junli; Jia, Jia; Li, Xuepeng; Dong, Liangliang; Li, Jianrong

    2013-12-15

    The effects of ferrous iron, heating temperature and different additives on the decomposition of trimethylamine oxide (TMAO) to formaldehyde (FA) and dimethylamine (DMA) and generation of free radicals in jumbo squid (Dosidicus gigas) extract during heating were evaluated by electron spin resonance (ESR). The thermal decomposition of TMAO to TMA, DMA and FA and free radical signals was observed in squid extract, whereas no DMA, FA and free radical signals were detected in cod extract or in aqueous TMAO solution in vitro at high temperatures. Significant increase in levels of DMA, FA and radicals intensity were observed in squid extract and TMAO solution in the presence of ferrous iron with increasing temperature. Hydrogen peroxide stimulated the production of DMA, FA and ESR signals in squid extract, while citric acid, trisodium citrate, calcium chloride, tea polyphenols and resveratrol had the opposite effect. Similar ESR spectra of six peaks regarded as amminium radical were detected in the squid extract and TMAO-iron(II) solution, suggesting that the amminium radical was involved in the decomposition of TMAO. PMID:23993561