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Sample records for zhidkogo kristalla mbba

  1. Multiple Order Diffractions by laser-Injured Transient Grating in Nematic MBBA Film

    International Nuclear Information System (INIS)

    Kim, Seong Kyu; Kim, Hack Jin

    1999-01-01

    The laser-induced transient grating method is applied to study the dynamics of the nematic MBBA film. The nanosecond laser pulses of 355 nm are used to make the transient grating and the cw He-Ne laser of 633 nm is used to probe the dynamics. Strong multiple order diffractions are observed at high nematic temperatures. The reordering process induced by the phototransformed state, which is the locally melted state from the nematic sample, is attributed to the main origin of the multiple order diffractions from the nematic MBBA. The characteristics of the multiple order gratings are discussed with the grating profiles simulated from the multiple diffraction signals

  2. Ultrasonic absorption and velocity dispersion of binary mixture liquid crystal MBBA/EBBA

    International Nuclear Information System (INIS)

    Choi, K.

    1979-01-01

    The effect of phase transitions and the partial magnetic alignment for liquid crystal molecules on the ultrasonic absorption and velocity dispersion has been investigated. The binary mixture of Shiff base liquid crystals MBBA/EBBA (55:45 mole %) showed anomalous ultrasonic absorption and velocity dispersion at eutectic (Tsub(m) = -20 0 C) and clearing point (Tsub(c) = 50 0 C) at the frequency range of 5 MHz, 10MHz, 15MHz and 30 MHz. The experimental data were analyzed in terms of relaxation time and Fixman theory. The anisotropy of the propagation velocity due to the magnetic alignment was about 0.9% (the deviation between velocities propagating parallel and perpendicular to the applied field). (author)

  3. Effect of Potential Range in Pressure-Temperature Behavior in Isotropic-Nematic Transition of 4-4´-Bis(EthyloxyAzoxybenzene (P-Azoxyphenetole, Pap, 4-Pentyl-4´-Cyanobiphenyl (5cb, P-Methoxybenzydidene-P-N-Butylaniline (Mbba and P–Ethoxybenzylidene–P–N-Butylaniline (Ebba

    Directory of Open Access Journals (Sweden)

    García-Sánchez E.

    2011-04-01

    Full Text Available In this work we employed the Density Functional Theory (IPCM model to calculate molecular volume and k, and the perturbation theory proposed by García-Sánchez et al. (2002 to predict phase diagram and experimental behavior pressure-temperature for isotropic-nematic transition of 4-4´-bis(ethyloxyazoxybenzene (p-azoxyphenetole, PAP, 4-pentyl-4´-cyanobiphenyl (5CB, p-methoxybenzydidene-p-n-butylaniline (MBBA and p–ethoxybenzylidene–p–n-butylaniline (EBBA at 1 atm. If during the theoretical prediction bigger potential values of potential range of square well (l > k are considered in the theoretical model, it is possible to get better prediction of the experimental behavior. The above mentioned is according with the theoretical formulation of the Second Order Perturbation Theory since Ponce-Renon approximation is included.

  4. The Comparative Accuracy of the 4 {pi} Liquid Scintillation Counting Method of Radioisotope Standardization; L'exactitude comparee de la methode de comptage 4 {pi} a scintillateurs liquides pour l'etalonnage des radioisotopes; Sravnitel'naya tochnost' 4 {pi} zhidkogo stsintillatsionnogo metoda podscheta standartiziruemykh radioizotopov; Exactitud del metodo de recuento con centelleador liquido 4 {pi} para normalizar radioisotopos, comparada con la de otros metodos

    Energy Technology Data Exchange (ETDEWEB)

    Steyn, J [National Physical Research Laboratory, Pretoria (South Africa)

    1960-06-15

    The accuracy of the 4 {pi} liquid scintillation counting method of standardizing {beta} emitters was compared to 4 l{pi} {beta}-{gamma} coincidence counting for the nuclides Co{sup 60}, I{sup 131} and Au{sup 198}. For P{sup 32} the liquid counting results were compared to 4 {pi} proportional counting. The efficiency of the liquid scintillation counting method was found to be energy dependent, dropping to about 97.5% for Co{sup 60} which was the lowest energy {beta} emitter investigated. (author) [French] La precision de la methode de comptage 4 {pi} a scintillateurs liquides pour l'etalonnage des emetteurs {beta} a ete comparee au comptage par coincidences 4 {pi} {beta}-{gamma} pour le So{sup 60}, le I{sup 131} et le Au{sup 198}. Dans le cas du P{sup 32}, les resultats du comptage au liquide ont ete compares a ceux du comptage 4 {pi} proportionnel. On a constate que le rendement de la methode de comptage a scintillateurs liquides variait en fonction de l'energie emise et qu'il descendait a environ 97.5% pour le Co{sup 60} qui, de tous les emetteurs {beta} etudies, emet l'energie la plus faible. (author) [Spanish] El autor compara la precision del metodo de recuento con centelleador iquido 4 {pi} para normalizar emisores {beta} con la del metodo de coincidencias {beta}-{gamma} 4 {pi}, para los siguientes nuclidos: So{sup 60}, I{sup 131} y Au{sup 198}. En el caso del P{sup 32}, confronta los resultados del primer metodo con los obtenidos mediante el recuento proporcional 4 {pi}. Comprueba que la eficacia del metodo de recuento con centelleador liquido depende de la energia y desciende al 97.5%, aproximadamente, para el Co{sup 60}, que fue el emisor {beta} mas debil que se investigo. (author) [Russian] Tochnost' 4 {pi} zhidkogo stsintillyatsionnog o metoda podscheta standartiziruemogo {beta}-izluchatelya sravnivalas' s 4 {pi} {beta}-{gamma} metodom podscheta na sovpadeniyakh dlya izotopov So{sup 60}, I{sup 131} i Au{sup 198}. Dlya R{sup 32} rezultaty zhidkogo

  5. Detection of a new 'nematic-like' phase in liquid crystal-amphiphile mixture by differential scanning calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Dan, Kaustabh, E-mail: kaustabhdan@gmail.com; Roy, Madhusudan, E-mail: kaustabhdan@gmail.com; Datta, Alokmay, E-mail: kaustabhdan@gmail.com [Surface Physics and Materials Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar Block, Sector 1, Kolkata-700064 (India)

    2014-04-24

    Differential Scanning Calorimetry (DSC) studies on phase transitions of the pure liquid crystalline material N-4-methoxybenzylidene-4-butylaniline (MBBA) and mixtures of MBBA and the amphiphile Stearic Acid (StA) show significant changes in the behavior of mixture from pure MBBA, as regards the nematic-isotropic (N-I) transition temperature (T{sub c}) and other thermodynamic parameters like enthalpy, specific heat and activation energy with concentration of StA. In particular, the convexity of the Arrhenius plot in pure MBBA vanishes with StA concentration pointing to the formation of a new, perhaps 'nematic-like', phase in the mixtures.

  6. Direct Measurement of Tritium in Biological Materials with the Liquid Scintillation Counter; Determination quantitative directe du tritium dans les substances biologiques, au moyen de compteurs a scintillations a liquides; Neposredstvennoe izmerenie kolichestva tritiya v biologicheskikh materialakh pri pomoshchi zhidkogo stsintillyatsionnogo schetchika; Determinacion cuantitativa directa del tritio en sustancias biologicas mediante contadores de centelleador liquido

    Energy Technology Data Exchange (ETDEWEB)

    Halvorsen, K [Institutt for Atomenergi, Kjeller, Lillestroem (Norway)

    1962-01-15

    Procedures for measurement of tritium in animal tissues and isolated tissue fractions have been reported in the literature. In all the work reported, however, a liquid scintillation coincidence spectrometer has been used for the counting of the samples. In this work a single phototube liquid scintillation counter was used for the measurements. Investigation centred primarily on the direct dissolution of animal tissue in Hyamine 10-X and the suspension counting of lyophilized tissue in scintillating gels. Different tissues, such as liver, intestine, blood and skin, can be dissolved directly in Hyamine and measured with an efficiency of 10-15%. The techniques of quenching correction and certain phosphorescence phenomena as they affect the counting in a single phototube counting system are discussed. The sensitivity of the method, although somewhat less than that of the coincidence-counting arrangement, seems to be sufficient for many applications. The work reported was carried out on tissue samples from mice previously injected with tritium- labelled thymidine. When a dose of approximately 1 {mu}c tritiated thymidine per g of body weight was injected into the mice, the metabolic fate of the thymidine incorporated into deoxyribonucleic acid (DNA) of the various tissues could be followed for a period of one month. (author) [French] Diverses techniques de determination du tritium dans les tissus animaux et fractions isolees de tissus animaux ont deja ete decrites. Mais toutes comportent l'emploi d'un spectrometre de coincidences a scintillations a liquides pour le comptage des echantillons. Pour faire cette determination, l'auteur s'est servi d'un seul phototube-compteur a scintillations a liquides. Il a etudie surtout la dissolution directe de tissu animal dans de l'hyamine 10-X, et le comptage de tissus lyophilises en suspension dans des gels a scintillations. Certains tissus, tels que le foie, l'intestin, le sang et la peau, peuvent Etre dissous directement dans l'hyamine et le rendement de la detection peut etre de 10 a 15%. L'auteur examine les techniques de correction de coupage et certains phenomenes de phosphorescence dans la mesure ou ils ont une influence sur le dispositif de comptage a un seul phototube. Cette methode, bien que moins precise que le dispositif de coincidence, l'est suffisamment pour de nombreuses applications. L'experience qui fait l'objet du memoire a porte sur des echantillons de tissus de souris auxquelles on avait injecte au prealable de la thymidine marquee au tritium. Lorsqu'une dose d'environ 1 {mu}c de thymidine tritiee par gramme de poids du corps est injectee aux souris, on peut suivre pendant un mois les transformations metaboliques de la thymidine incorporee a l'acide deoxyribonucleique (ADN) des divers tissus. (author) [Spanish] Ya se han presentado informes acerca de los procedimientos aplicados para la determinacion cuantitativa del tritio en tejidos animales y fracciones aisladas de los mismos. Sin embargo, en los trabajos respectivos se han utilizado siempre, para el recuento de la muestra, espectrometros de coincidencia de centelleador liquido. En cambio, en el presente trabajo las mediciones se han efectuado con un contador de centelleador liquido equipado con un fototubo unico. Se investigo principalmente la disolucion directa de tejido animal en la hiamina 10-KH y el recuento del tejido liofilizado en suspension en geles de centelleo. Es posible disolver directamente en hiamina tejidos diferentes tales como el hepatico, el intestinal, el sanguineo y el cutaneo, y medirlos con un rendimiento de 10 a 15%. El autor examina la tecnica aplicada para la correccion por extincion, asi como ciertos fenomenos de fosforescencia que afectan la determinacion en el sistema de recuento de fototubo unico. Parece que el metodo ofrece una sensibilidad suficiente para muchas aplicaciones, aunque un poco menor que la del dispositivo de recuento por coincidencias. La labor de que se informa se llevo a cabo con muestras de tejidos de raton a los que se habia inyectado previamente timidina marcada con tritio. Despues de inyectar al raton una dosis del orden de 1 {mu}c de timidina tritiada por gramo de peso corporal, se pudieron seguir durante un mes las transformaciones metabolicas de la timidina incorporada al acido desoxirribonucleico (DISIA) de los distintos tejidos. (author) [Russian] V literature uzhe soobshchalos' o sposobakh izmereniya kolichestva tritiya v tkanyakh zhivotnykh i v izolirovannykh srezakh tkanej. Odnako pri vsekh opisyvaemykh rabotakh dlya otscheta impul'sov obraztsov primenyalsya zhidkostnyj stsintillyatsionnyj spektrometr sovpadenij. Pri vypolnenii nastoyashchej raboty dlya izmerenij byl ispol'zovan zhidkostnyj stsintillyatsionnyj schetchik s odnim fotoehlementom. Issledovalis' glavnym obrazom neposredstvennoe rastvorenie tkanej zhivotnykh v giamine 10-KH i otschet impul'sov vzvesi liofilirovannoj tkani v stsintilliruyushchikh gelyakh. Razlichnye tkani, kak naprimer, pechen', kishechnik, krov' i kozha mogut byt' neposredstvenno rastvoreny v giamine i aktivnost' ikh izmerena s tochnost'yu do 10-15 protsentov. Budut obsuzhdeny metody vvedeniya popravki na gashenie i nekotorye yavleniya fosforestsentsii, poskol'ku oni vliyayut na otschet impul'sov v schetnom ustrojstve s edinym fotoehlementom. KHotya chuvstvitel'nost' ehtogo metoda predstavlyaetsya neskol'ko men'shej, chem pri ispol'zovanii schetchika sovpadenij, odnako ehtot metod udovletvoritelen dlya mnogikh vidov primenenij. Predstavlyaemaya rabota byla provedena na obraztsakh tkanej myshi posle predvaritel'noj in{sup e}ktsii mechennogo tritiem timidina. Pri vpryskivanii v mysh' dozy priblizitel'no v 1 mikrokyuri tritirovannogo timidina na gramm vesa ee tela, metabolicheskaya sud'ba timidina, pogloshchennogo deoksiribonukleinovoj kislotoj razlichnykh tkanej, mogla byt' proslezhena v techenie tselogo mesyatsa. (author)

  7. AUTHOR INDEX

    Indian Academy of Sciences (India)

    Administrator

    hol (MBBA)resin as polymer-supported synthesis support: ... 203. Luo S. Catalytic synthesis of 2-methylpyrazine over Cr-pro- .... Roy S C. Titanium(III) chloride mediated synthesis of furan ... Gas phase toluene isopropylation over high silica.

  8. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    step sequence under microwave irradiation involving the reaction of commercially available Merrifield resin with vanillin, followed by reduction with sodium borohydride. MBBA resin was treated with bromides in the presence of sodium hydride to ...

  9. Theory of the Influence of Phonon-Phonon and Electron-Phonon Interactions on the Scattering of Neutrons by Crystals; Theorie de l'influence des interactions phonon-phonon et electron-phonon sur la diffusion des neutrons par des cristaux; Teoriya vliyaniya vzaimodejstvij fonon-fonon iehlvktron-fonon na rasseyanie nejtronov kristalla-; Teoria de la influencia de las interacciones fonon-fonon y electron-fonon en la dispersion de neutrones por cristales

    Energy Technology Data Exchange (ETDEWEB)

    Kokkedee, J J.J. [Institute for Theoretical Physics of the University of Utrecht (Netherlands)

    1963-01-15

    As predicted by harmonic theory the coherent inelastic spectrums of neutrons, scattered by a single, non-conducting crystal, for a particular angle of scattering consists of a number of delta-function peaks superposed on a continuous background. The peaks correspond to one-phonon processes in which one phonon is absorbed or emitted by the neutron; the background arises from multi-phonon processes. When anharmonic forces (phonon-phonon interactions) are present, the delta-function peaks are broadened into finite peaks, while their central frequencies are shifted with respect to the harmonic values. In the case of a metal there is in addition to phonon-phonon interactions an interaction between phonons and conduction electrons, which also gives a contribution to the displacement and broadening oftheone-phononpeaks. Continuing earlier work of Van Hove (sho considered the relatively simple case of a non-conductin crystal in its ground state (T = 0{sup o}K) ), we have studied the shifts and widths of the scattering peaks as a 'result of the above-mentioned interactions by means of many particle perturbation theory, making extensive use of diagram techniques. Prerequisite to the entire discussion is the assumption that, independent of the strength of the interactions, the width of each peak is small compared to the value of the frequency at its centre; only then the peaks can be considered as being well defined with respect to the background to higher order in the interactions. This condition is expected to be fulfilled for temperatures which are not too high and values of the phonon wave vector which are not too large. Our procedure yields closed formulae for the partial scattering function describing the peaks, which can be evaluated to arbitrarily high accuracy. In particular an expansion for calculating the line shift and line width in powers of u/d and in terms of simple connected diagrams is obtained (u is an average atomic or ionic displacement, d is the smallest interatomic or interionic distance in the crystal). Approximate calculations are performed to give some insight into the orders of magnitude of the effects under study. (author) [French] Comme le predit la theorie harmonique, le spectre de la diffusion inelastique coherente de neutrons par un monocristal non conducteur, pour un angle de diffusion donne, se compose d'une serie de pics de fonction delta, qui se superposent a un bruit de fond continu. Les pics correspondent a des phenomenes a un phonon, dans lesquels un phonon est absorbe ou emis par le neutron; le bruit de fond provient de phenomenes a plusieurs phonons. Lorsqu'il existe des forces anharmoniques (interaction phonon-phonon) les pics de fonction delta s'elargissent pour former des pics finis et leur frequence centrale est dephasee par rapport aux valeurs harmoniques. Dans le cas d'un metal il y a, en plus des interactions phonon-phonon, une interaction entre les phonons et les electrons de conduction, laquelle contribue a dephaser et elargir encore davantage les pics a un phonon. Continuant les travaux de Van Hove (qui avait considere le cas relativement simple d'un cristal non conducteur a l'etat fondamental, soit T = 0{sup o}K) l'auteut a etudie les deplacements et les largeurs des pics de diffusion resultant des interactions indiquees plus haut, a l'aide de la theorie de la perturbation a plusieurs particules, en ayant largement recours a la methode des diagrammes. Il admet, avant tout examen du probleme, que quelle que soit la force des interactions, la largeur de chaque pic est petite par rapport a la valeur de la frequence en son centres dans ces conditions seulement, on peut considerer que les pics sont bien definis par rapport au bruit de fond, si les calculs d'interaction sont pousses jusqu'aux ordres superieurs. On estime que cette hipothbse est realisee tant que les temperatures ne sont pas trop elevees et que les valeurs du vecteur d'onde des phonons ne sont pas trop considerables. La methode appliquee par l'auteur lui permet d'obtenir des formules fermees pour la fonction de diffusion partielle decrivant les pics, qui peuvent etre calculees avec une approximation aussi pousee qu'on le desire. L'auteur a obtenu notamment une expression qui permet de calculer le dephasage et la largeur des raies en puissances de u/d et en fonction de diagrammes connectes simples (u etant le deplacement atomique ou ionique moyen et d la plus petite distance interatomique ou interionique dans le cristal). Des calculs approches donnent une idee de l'ordre de grandeur des effets etudies. (author) [Spanish] Como permite predecir la teoria armonica, el espectro de neutrones dispersados coherente e inelasticamente por un monocristal no conductor consiste, para un angulo de dispersion determinado, en una serie de picos de function delta supetpuestos a un fondo continuo. Los picos corresponden a procesos en que el neutron absorbe o emite un solo fonon; el fondo se debe a procesos de varios fonones. Cuando intervienen fuerzas anarmonicas (interacciones fonon-fonon), los picos de funcion delta se ensanchan, convirtiendose en picos finitos y sus frecuencias centrales se desplazan respecto de los valores armonicos. En el caso de los metales, ademas de las interacciones fonon-fonon existe interaccion entre los fonones y los electrones de conduccion, lo que tambien contribuye al desplazamiento y ensanchamiento de los picos correspondientes a los procesos de un solo fonon. Prosiguiendo trabajos anteriores de Van Hove (quien investigo el caso relativamente sencillo de un cristal no conductor en el estado fundamental (T = 0{sup o}K) ), el autor ha estudiado el desplazamiento y la amplitud de los picos de dispersion resultantes de las mencionadas interacciones aplicando la teoria de las perturbaciones originadas por partfbulas multiples y utilizando ampliamente tecnicas de diagramas. Un requisito indispensable para dicho estudio es la hipotesis de que, sea cual fuere la intensidad de las interacciones, la amplitud de cada pico es pequena en comparacion con el valor de la frecuencia en el centro: solo en tal caso puede considerarse que los picos estan bien definidos respecto del fondo correspondiente a las interacciones de oiden mas elevado. Cabe esperar que esta condicion se cumpla para temperaturas no demasiado elevadas y valores de vector de onda fononico no excesivamente grandes. El procedimiento del autor permite obtener formulas cerradas de la funcion de dispersion parcial que describe los picos; estos pueden evaluarse con el grado de precision que se desee. En particular, se obtiene un desarrollo para calcular en potencias de u/d y en funcion de diagramas simples conectados el desplazamiento y la anchura de las rayas (u es el desplazamiento atomico o ionico medio y d es la distancia minima interatomica en el cristal). El autor efectua calculos aproximados para dar una idea del orden de magnitud de los efectos estudiados. (author)

  10. The microwave heating mechanism of N-(4-methoxybenzyliden)-4-butylaniline in liquid crystalline and isotropic phases as determined using in situ microwave irradiation NMR spectroscopy.

    Science.gov (United States)

    Tasei, Yugo; Tanigawa, Fumikazu; Kawamura, Izuru; Fujito, Teruaki; Sato, Motoyasu; Naito, Akira

    2015-04-14

    Microwave heating effects are widely used in the acceleration of organic, polymerization and enzymatic reactions. These effects are primarily caused by the local heating induced by microwave irradiation. However, the detailed molecular mechanisms associated with microwave heating effects on the chemical reactions are not yet well understood. This study investigated the microwave heating effect of N-(4-methoxybenzylidene)-4-butylaniline (MBBA) in liquid crystalline and isotropic phases using in situ microwave irradiation nuclear magnetic resonance (NMR) spectroscopy, by obtaining (1)H NMR spectra of MBBA under microwave irradiation. When heated simply using the temperature control unit of the NMR instrument, the liquid crystalline MBBA was converted to the isotropic phase exactly at its phase transition temperature (Tc) of 41 °C. The application of microwave irradiation at 130 W for 90 s while maintaining the instrument temperature at 20 °C generated a small amount of isotropic phase within the bulk liquid crystal. The sample temperature of the liquid crystalline state obtained during microwave irradiation was estimated to be 35 °C by assessing the linewidths of the (1)H NMR spectrum. This partial transition to the isotropic phase can be attributed to a non-equilibrium local heating state induced by the microwave irradiation. The application of microwave at 195 W for 5 min to isotropic MBBA while maintaining an instrument temperature of 50 °C raised the sample temperature to 160 °C. In this study, the MBBA temperature during microwave irradiation was estimated by measuring the temperature dependent chemical shifts of individual protons in the sample, and the different protons were found to indicate significantly different temperatures in the molecule. These results suggest that microwave heating polarizes bonds in polar functional groups, and this effect may partly explain the attendant acceleration of organic reactions.

  11. Geometry of third ventricle: radiological measurements supported by neuroendoscopic observations

    Energy Technology Data Exchange (ETDEWEB)

    Novak, Z.; Chrastina, J. [Neurosurgical Dept., Faculty Hospital, St Anns, MF MU, Brno (Czech Republic); Krupa, P.; Feitova, V. [Dept. of Imaging Techniques, Faculty Hospital, St Anns, MF MU, Brno (Czech Republic); Riha, I. [Neurosurgical Dept., Faculty Hospital, St Anns, MF MU, Brno (Czech Republic); Inst. of Biomedical Engineering, FEEC BUT, Brno (Czech Republic)

    2007-06-15

    The aim od the study was to analyse the changes of third ventricular geometry caused by hydrocephalus. The data were obtained from planning studies for neuroendoscopic surgeries using stereotactic software Praezis Plus. Parameters CA-CP (intercommisural distance-corresponding to third ventricular length), IMD (intermammillary distance-third ventricular width), H (third ventricular height), BA-DS distance (distance between basilar artery bifurcation and dorsum sellae) and MB-BA distance were studied. After statistical analysis table of normal values is proposed for all the defined parameters. Statistically significant changes were found in all the measured parameters (CA-CP, IMD, H, MB-BA) in hydrocephalic patients except the distance between basilar artery and dorsum sellae, defining safe area for endoscopic third ventriculostomy. (orig.)

  12. Near-infrared dichroism of a mesogenic transition metal complex and its solubility in nematic hosts

    International Nuclear Information System (INIS)

    Marshall, K.L.; Jacobs, S.D.

    1987-01-01

    A transition metal complex possessing the nematic phase, bis (p-n-butylstyryl-1, 2-dithiolato) nickel, was synthesized and its optical properties and solubility in the nematic hosts K15 and MBBA were investigated. The metal complex displayed a high solubility in both host materials (up to 10% wt/wt) and a strong near-infrared absorption band centered at 860 nm. A blocking extinction of greater than OD = 3 was obtained with a 100 micron pathlength of a 0.5% wt/wt mixture of the nematic metal complex in K15, suggesting its usefulness for passive blocking of near infrared radiation. A 24 micron thick, homogeneously aligned guest-host cell containing a 1% wt/wt mixture of the metal complex in K15 possessed a contrast ratio of nearly 5:1 and a blocking extinction of OD = 3.5 at 860 nm, demonstrating for the first time the existence of near-infrared dichroism in this class of materials. The solubility and blocking extinction of the mesogenic metal complex in K15 was considerably superior to the non-mesogenic near ir laser dye bis(dimethylaminodithiobenzil) nickel in the same host. An interaction of the nematic metal complex in mixtures with MBBA which resulted in the creation of a new absorption band at 1050 nm was also observed. 21 refs., 9 figs

  13. Optimization of Nanocomposite Solar Cell/Liquid Crystal Matrix to Diminish High Intensity Laser Light Relevant to Aviation Safety Applications

    Science.gov (United States)

    Hofmann, James A.

    An increasing threat to the aviation industry is laser light illumination on airplanes during critical phases of flight. If a laser hits the cockpit, it not only distracts the pilots, but it can cause flash blindness or permanently damage the vision of the pilots. This research attempts to mitigate these lasers illuminations through the application of both liquid crystal (LC's) technologies and dye sensitized solar cell (DSSC) technologies. The LC of choice is N-(4-Methoxybenzylidene)-4-butylaniline, or MBBA, because it has special optical properties including the ability to undergo phase transitions when exposed to an electric field. By applying an external electric field, MBBA switches from its transparent nematic phase, to its non-transparent crystalline phase, blocking the laser light. This research optimized the application of MBBA by reducing the triggering voltage and relaxation time of the LC using spacer thicknesses and scratching techniques. The liquid to solid phase transition was reduced to a 3V differential, and the time required for the crystals to relax into its transparent liquid phase was reduced to less than ten seconds. The phase transition was studied using an external electric field generated by DSSCs constructed from a titanium dioxide (TiO2) nanocomposite layer coated with dye. To maximize the voltage output by the DSSCs, layer thickness and dye sensitizer were studied to investigate their impact on the performance of the DSSC when illuminated by solar lamps and green light (532nm). Three different layer thicknesses and five different dyes were tested: Eosin Y, Eriochrome Black, Congo Red, Fast Green, and Alizarine Yellow. The experimental results showed a thin layer of nanocomposite sensitized with Eosin Y dye produced the most efficient DSSCs for the scope of this research. Experimental testing showed the DSSCs can generate 381 +/- 10mV under solar lamp exposure, 356 +/- 10mV under laser light exposure, and a voltage increase of 60 +/- 16m

  14. Optics of Confined Liquid Crystals for Gas Detection

    Science.gov (United States)

    Charles, William; Carrozzi, Daniel; Vigilia, Lee Anne; Wang, Xiaoyurui; Guzman, Violet; Shibayev, Petr; Fordham University Students of Undergraduate Physics Team

    Cholesteric liquid crystals (CLCs) of a wide range of viscosities were studied experimentally in relation to their use as gas sensors and sensors of volatile organic compounds (VOCs), specifically ethanol, cyclohexane, toluene, acetic acid, and pyridine. CLCs were obtained by mixing low molar mass liquid crystals (MBBA and cholesterol derivatives with siloxane based oligomers). The droplets of CLCs were placed in containers with controlled atmospheres. The shift of the selective reflection band, predominantly from shorter to longer wavelengths, and the color changes were observed in the CLC illuminated by light coming from the various directions. Visible optical changes were observed in droplets with viscosities of CLCs ranging from c.a. 4 Pa*s to 105 Pa*s. The most responsive droplets in which the shift of the selective reflection band occurs at lower concentrations of VOCs were prepared from CLC mixtures with the lowest viscosities. Higher viscosities of CLCs lead to a slower response to VOCs, but the rate of response is different for each pair of VOC and CLC with a certain viscosity. This finding opens a possibility for selective detection of VOCs by CLCs with different viscosities. The mechanism of VOCs diffusion, interaction with CLC matrix and optical changes is discusse

  15. Electrochemical Aptasensor for Myoglobin-Specific Recognition Based on Porphyrin Functionalized Graphene-Conjugated Gold Nanocomposites

    Directory of Open Access Journals (Sweden)

    Guojuan Zhang

    2016-10-01

    Full Text Available In this work, a novel electrochemical aptasensor was developed for sensitive and selective detection of myoglobin based on meso-tetra (4-carboxyphenyl porphyrin-functionalized graphene-conjugated gold nanoparticles (TCPP–Gr/AuNPs. Due to its good electric conductivity, large specific surface area, and excellent mechanical properties, TCPP–Gr/AuNPs can act as an enhanced material for the electrochemical detection of myoglobin. Meanwhile, it provides an effective matrix for immobilizing myoglobin-binding aptamer (MbBA. The electrochemical aptasensor has a sensitive response to myoglobin in a linear range from 2.0 × 10−11 M to 7.7 × 10−7 M with a detection limit of 6.7 × 10−12 M (S/N = 3. Furthermore, the method has the merits of high sensitivity, low price, and high specificity. Our work will supply new horizons for the diagnostic applications of graphene-based materials in biomedicine and biosensors.

  16. Electric-field triggered controlled release of bioactive volatiles from imine-based liquid crystalline phases.

    Science.gov (United States)

    Herrmann, Andreas; Giuseppone, Nicolas; Lehn, Jean-Marie

    2009-01-01

    Application of an electric field to liquid crystalline film forming imines with negative dielectric anisotropy, such as N-(4-methoxybenzylidene)-4-butylaniline (MBBA, 1), results in the expulsion of compounds that do not participate in the formation of the liquid crystalline phase. Furthermore, amines and aromatic aldehydes undergo component exchange with the imine by generating constitutional dynamic libraries. The strength of the electric field and the duration of its application to the liquid crystalline film influence the release rate of the expelled compounds and, at the same time, modulate the equilibration of the dynamic libraries. The controlled release of volatile organic molecules with different chemical functionalities from the film was quantified by dynamic headspace analysis. In all cases, higher headspace concentrations were detected in the presence of an electric field. These results point to the possibility of using imine-based liquid crystalline films to build devices for the controlled release of a broad variety of bioactive volatiles as a direct response to an external electric signal.

  17. Basic principles of scintillation counting; Principes de Base du Comptage par Scintillations; Osnovnye printsipy stsintillyatsij; Principios fundamentales del recuento con aparatos de centelleo

    Energy Technology Data Exchange (ETDEWEB)

    Johns, H E; Cederlund, J F [Ontario Cancer Institute, Toronto (Canada)

    1959-07-01

    The effect of the energy of radiation, the crystal size, the collimation of the beam and scattering on the pulse-height distribution produced by monoenergetic radiation will be discussed. These aspects will be related to scintillation scanning. The effects of voltage on the operation of photomultiplier s and so-called plateaus will be dealt with. Glow-transfer tubes for counting will be dealt with and a useful substraction circuit for comparing the counting rate from two separate scintillation counters will be presented. (author) [French] Les auteurs examineront l'effet de l'energie du rayonnement, de la dimension du cristal, de la collimation du faisceau et de la diffusion sur la repartition de l'amplitude des impulsions dues au rayonnement monoenergetique, en rattachant l'etude de ces questions a l'exploration par scintillations. Ils etudieront egalement les effets de la tension sur le fonctionnement des photomultiplicateurs et des , ainsi que l'utilisation de pour le comptage; ils presenteront enfin un circuit de soustraction utile servant a comparer le taux de comptage de deux scintillometres distincts. (author) [Spanish] Los autores estudiaran el efecto que la energia de la radiacion, el tamano del cristal, la colimacion del haz y la dispersion ejercen sobre la distribucion de la amplitud de los impulsos debida a la radiacion monoenergetica, relacionando todas estas cuestiones con la exploracion mediante aparatos de centelleo. Examinaran tambien la influencia de las variaciones de tension sobre el funcionamiento de los fotomultiplicadores y sobre las denominadas , asi como los tubos luminiscentes de transmision para el recuento; por ultimo, presentaran un circuito de sustraccion que sirve para comparar el indice de recuento de dos contadores de centelleo distintos. (author) [Russian] Budet obsuzhdat'sya vliyanie ehnergii izlucheniya, velichiny kristalla, kollimirovaniya lucha i, nakonets, rasseyaniya na amplitudnoe

  18. New developments in the analysis and measurement of thicknesses by {beta}-particle excitation of X fluorescent rays; Nouveaux developpements de l'analyse et de la mesure des epaisseurs par excitation des raies de fluorescence X au moyen de particules {beta}; Novye usovershenstvovaniya analiza i izmereniya plotnosti putem vozbuzhdeniya fluorestsiruyushchikh spektrov rentgenovskogo lucha beta-chastitsami; Nuevos adelantos en el analisis y la medicion de espesores mediante la excitacion de rayos X por particulas beta

    Energy Technology Data Exchange (ETDEWEB)

    Martinelli, P [Commissariat a l' Energie Atomique, Saclay (France); Seibel, G [Institut de Recherches de la Siderurgie, St-Germain-en-Laye (France)

    1962-01-15

    kriptona-85 daet vozmozhnost' umen'shit' fon, kotoryj nablyudaetsya pri ispol'zovanii strontsiya-90. Privodyatsya dannye, poluchennye dlya razlichnykh izmerenij plotnosti metallicheskikh sloev, analiz rastvorov i nepreryvnoe izmerenie kal'tsiya i zheleza v rudnykh porodakh. Daetsya opisanie opytov, provedennykh s tsel'yu analiza rentgenovskogo oblucheniya s pomoshch'yu kristalla. (author)

  19. Solid sources of krypton-85; Sources solides de krypton-85; Tverdye istochniki kriptona-85; Fuentes solidas de cripton-85

    Energy Technology Data Exchange (ETDEWEB)

    Puig, J R; Sandier, J [Centre d' Etudes Nucleaires de Saclay (France)

    1962-01-15

    industria. Sin embargo, la preparacion de fuentes industriales de {sup 85}Kr plantea dificultades porque este elemento se presenta en forma gaseosa y no puede ser fijado quimicamente. En la presente memoria los autores exponen un metodo de fijacion del cripton en una matriz macromolecular obtenida por polimerizacion en masa de un monomero liquido que contiene al cripton, y describen la preparacion de dos tipos de fuentes obtenidas segun este principio - una a base de poliestireno y la otra a base de acetato de polivinilo. Estas fuentes dejan escapar parte del cripton, por lo que su actividad disminuye diariamente a razon de 8 % en el primer caso y de 3 % en el segundo. Estos decrecimientos aparentes permiten calcular los coeficientes de difusion del cripton en los polimeros. Al parecer, los enlaces de reticulacion del polimero impiden la difusion. (author) [Russian] Kripton-85, kotoryj yavlyaetsya dolgozhivushchim beta-izluchatelem i predstavlyaet soboj neznachitel'nuyu biologicheskuyu opasnost', daet vazhnye preimushchestva pri ego promyshlennom ispol'zovanii. No izgotovlenie ego istochnikov yavlyaetsya trudnym delom, tak kak ehtot ehlement nakhoditsya v gazoobraznom sostoyanii i ego nel'zya fiksirovat' khimicheskim putem. Avtory izlagayut metod fiksatsii kriptona v makromolekulyarnoj matritse, obrazovannoj polimerizatsiej zhidkogo monomera, soderzhashchego kripton, i opisyvayut izgotovlenie dvukh tipov istochnikov, prigotovlennykh po ehtomu printsipu: odin zaklyuchen v polistirol, a drugoj - v polivinilovyj atsetat. Poluchennye takim obrazom istochniki ispuskayut kripton, i ikh aktivnost' umen'shaetsya v den' na 8 % dlya pervogo i na 3 % dlya vtorogo. EHti zametnye umen'sheniya dayut vozmozhnost' vychislit' koehffitsienty diffuzii kriptona v ztikh polimerakh. EHtoj diffuzii, po-vidimomu, prepyatstvuyut poperechnye svyazi, sushchestvuyushchie v polimere. (author)

  20. A New Technique for Determining the Distribution of Radium and Thorium in Living Persons; Determination de la Repartition du Radium et du Thorium chez les Personnes Vivantes: Une Methode Nouvelle; Novyj metod opredeleniya raspredeleniya radiya i toriya u patsientov; Nueva Tecnica para Determinar la Distribucion del Radio y del Torio en Pacientes

    Energy Technology Data Exchange (ETDEWEB)

    Miller, C. E. [Argonne National Laboratory, Health Division, Argonne, IL (United States)

    1964-10-15

    pacienta. Jeta vytjanutaja forma kristalla byla primenena vmesto obychnogo vertikal'no raspolozhennogo korotkogo cilindra dlja togo,-chtoby ploshhad' poverhnosti i poperechnoe sechenie kristalla imeli odinakovuju formu po otnosheniju k ljuboj tochke tela. Spektry gamma-luchej, ishodjashhih ot pozvonochnika pacienta i ot radioaktivnyh istochnikov v centre fantoma iz pressovannoj drevesiny, byli polucheny pri pomoshhi kristalla, pomeshhaemogo v h-chisle polozhenij s odinakovymi intervalami vdol' krovati. Skorosti scheta, poluchennye dlja otobrannyh fotopikov iz spektrov pacienta i fantoma, byli vvedeny v jelektronnoschetnoe ustrojstvo, zaprogrammirovannoe dlja podscheta serii tochechnyh istochnikov, chto daet tot zhe samyj profil' gamma-luchej. Rezul'taty, poluchennye pri issledovanii rjada pacientov, svidetel'stvujut o tom. chto hotja raspredelenie chashhe vsego v osnovnom odnorodno, u nekotoryh lic koncentracija v dva ili tri raza vyshe srednej v nogah, tazu ili v cherepe. Itogi vychislennyh istochnikov sootvetstvujut v predelah'neskol'kih procentov obshhemu soderzhaniju radija v organizme, podschitannomu na osnovanii drugih metodik izmerenija aktivnosti vsego organizma. Izmerenija, provedennye u dvuh pacientov, poluchavshih torotrast bolee devjatnadcati let nazad, i na fantomah, soderzhashhih torotrast i radij-torij, takzhe svidetel'stvovali o vozmozhnosti izmerenija neodnorodnogo raspredelenija Tl{sup 208} (ThC''), Ac{sup 228}(MsTh{sup 2}) i, vozmozhno, Pb{sup 212} vdol' osi tela. (author)

  1. Diffusion in moving grain-boundaries; Diffusion aux joints de grains en mouvement; Diffuziya na peremeshchayushchikhsya granichnykh poverkhnostyakh zeren; Difusion de los limites intergranulares en movimiento

    Energy Technology Data Exchange (ETDEWEB)

    Blackburn, D A; Brown, A F [Solid State Laboratory, University of Edinburgh, Edinburgh (United Kingdom)

    1962-01-15

    supera el 100% en los intervalos estudiados. (author) [Russian] Sparennye kristally medi peremeshchalis' vdol' obshchej granichnoj poverkhnosti so skorost'yu v 0,06-0,3 {mu}/ch pri temperaturakh okolo 725{sup o} C. Pri pomoshchi avtoradiografii bylo izucheno proniknovenie Ag{sup 110} v nepodvizhnye i v peremeshchaemye granichnye poverkhnosti. Kak dlya peremeshchayushchikhsya, tak i dlya nepodvizhnykh granichnykh poverkhnostej bylo polucheno khoroshee sovpadenie s formuloj Fishera. Otnoshenie koehffitsientov diffuzii na granichnoj poverkhnosti zerna i koehffitsienta diffuzii v masse kristalla (D'/D) poryadka 10{sup 6}. Dlya issledovannykh granichnykh poverkhnostej D'/D-10{sup 6}, okazyvaetsya, chto D'/D slegka vozrastaet po mere uvelicheniya obshchego sdviga i ego skorosti, no na protyazhenii obsledovannogo intervala ehto sootnoshenie ne uvelichivalos' bol'she chem v dva raza. (author)

  2. Studies of the Solid and Liquid Phases of HF, HCl and HBr by Slow-Neutron Inelastic Scattering; Etude des Phases Solide et Liquide de HF, HCl Et HBr par la Diffusion Inelastique des Neutrons Lents; 0418 0417 0423 0427 0415 041d 0418 0415 0422 0412 0415 0420 0414 042b 0425 0418 0416 0418 0414 041a 0418 0425 0424 0410 0417 HF, HCl I HBr 0421 041f 041e 041c 041e 0429 042c 042e 041d 0415 0423 041f 0420 0423 0413 041e 0413 041e 0420 0410 0421 0421 0415 042f 041d 0418 042f 041c 0415 0414 041b 0415 041d 041d 042b 0425 041d 0415 0419 0422 0420 041e 041d 041e 0412 ; Estudio de las Fases Solida y Liquida del HF, HCl Y HBr por Dispersion Inelastica de Neutrones Lentos

    Energy Technology Data Exchange (ETDEWEB)

    Boutin, H. [Picatinny Arsenal, Dover, NJ (United States); Brookhaven National Laboratory, Upton, NY (United States); Safford, G. J. [Brookhaven National Laboratory, Upton, NY (United States)

    1965-06-15

    ). Jeti izmerenija proizvodilis' s cel'ju sistematicheskogo izuchenija vlijanija uvelichenija otricatel'nogo jelektricheskogo zarjada i razmerov anionov na nizkochastotnye molekuljarnye dvizhenija kak v tverdoj, tak i v zhidkoj fazah. HF issledovalsja pervym, t.k. dannye difrakcii rentgenovskih luchej pokazyvali, chto v tverdom sostojanii on obrazuet dlinnye zigzagoobraznye cepi s vodorodnoj svjaz'ju. Spektry nejaronov, neuprugo rassejannyh ot zhidkoj i tverdoj faz HF, jasno pokazali vysokuju stepen' associacii, sushhestvujushhuju vo vsej zhidkoj faze blagodarja vodorodnoj svjazi. S cel'ju interpretacii dannye po HF byli sopostavleny s dannymi analogichnogo rassejanija ionov HF i H{sub 2}F{sub 3}{sup -}, kotorye imejut struktury, analogichnye tem sostavnym chastjam v HF, kotorye vkljuchajut zigzagoobraznye cepi s vodorodnoj svjaz'ju. Jeti dannye byli takzhe sopostavleny s rezul'tatami izmerenij s pomoshh'ju infrakrasnyh luchej i izmerenij po metodu Ramana na ionah HF Pound-Sign . Jeti sopostavlenija pozvolili otlichit' chastotnuju harakteristiku otdel'noj sostavnoj chasti ot chastotnoj harakteristiki vsej cepi i ot nizkochastotnyh kolebanij reshetki. Linija, nabljudavshajasja pri 0,067 jev, byla associirovana s chastotoj deformacii v{sub 2} gruppy F-N...F v tverdom HF, i byla ustanovlena ee svjaz' s analogichnymi chastotami v ionah H{sub 2}F{sub 3}{sup -} i HF{sub 2}{sup -} kak frakcii rasstojanija F-F. Krome togo, shirokij pik, otmechennyj pri 0,007 jev, byl pripisan vrashhatel'nomu dvizheniju sostavnoj chasti F -F vokrug svjazi F -F. Spektr zhidkogo HF takzhe budet rassmatrivat'sja s tochki zrenija jetih dvizhenij. Spektry zhidkogo NS1 (180 Degree-Sign K), faz I i III tverdogo NS1 (143 i 85 Degree-Sign K sootvetstvenno), zhidkogo NVg (193 Degree-Sign K) i faz I i II tverdogo NVg (153 i 103 Degree-Sign K sootvetstvenno) byli sopostavleny s vysheukazannymi dannymi dlja HF. Jeti spektry pokazyvajut eshhe bol'shuju slozhnost', chem u HF. Jeto mozhet byt' ob{sup j

  3. Szilard-Chalmers Processes in Ammonium Dihydrogen Phosphate as Studied by Electrophoresis and Electron Spin Resonance Techniques; Processus Szilard-Chalmers dans le Phosphate d'Ammonium Biacide Etudies par ELectro- Phorese et Resonance de Spin Electronique; 0418 0417 0423 0427 0414 ; Procesos Szilard-Chalmers en el Fosfato Monoamonico Estudiados por Electroforesis y Resonancia del Spin Electronico

    Energy Technology Data Exchange (ETDEWEB)

    Fenger, J.; Nielsen, S. O. [Danish AEC Research Establishment, Riso (Denmark)

    1965-04-15

    pomoshh'ju jelektronno-spinovogo rezonansa (JeSR), my soobshhaem o rezul'tatah izuchenija s pomoshh'ju metodov jelektroforeza i jelektronno-spinovogo rezonansa otdel'nyh kristallov pervichnogo kislogo fosfata ammonija posle obluchenija nejtronami v teplovoj kolonke pri temperaturah mezhdu - 196 Degree-Sign i 40 Degree-Sign C. Spektry jelektronno-spinovogo rezonansa registrirovalis' pri ispol'zovanii otdel'nyh kristallov ND{sub 4}D{sub 2}PO{sub 4}, obluchennyh nejtronami. Byli najdeny chetyre sistemy linij. Tri iz nih, sostavljajushhie vneshnjuju chast' spektra, vosstanavlivajutsja v dublety v nekotoryh orientacijah kristalla, chto govorit o sverhtonkoj svjazi s fosforom-31. Central'naja chast' spektra mogla takzhe byt' poluchena pri chistom {gamma}-obluchenii. Odna iz sistem linij vo vneshnej chasti spektra byla proslezhena dlja gorjachih atomov otdachi v rezul'tate processa N{sup 14}(n, p)C{sup 14} i opredelena dlja radikalov fosfita, kotorye orientirovany v 8 razlichnyh napravlenijah v kristallicheskoj reshetke. Kratko obsuzhdajutsja rezul'taty teplovogo i radiacionnogo otzhiga, izuchennogo s primeneniem metodov jelektroforeza. Naibolee vazhnyj vyvod sostojal v tom, chto ND{sub 4}D{sub 2}PO{sub 4} i NH{sub 4}H{sub 2}PO{sub 4} posle nejtronnogo obluchenija pri temperature 4 Degree-Sign C, -78 Degree-Sign C i -196 Degree-Sign C otlichalis' po svoim uderzhanijam, kotorye priblizitel'no na 50% bol'she v ND{sub 4}D{sub 2}PO{sub 4} pri vseh treh temperaturah. Tri iz nih vosstanavlivajutsja v dublety v nekotoryh orientacijah kristalla, chto govorit o sverhtonkoj svjazi s fosforom-31. Do sih por ne najdeny dokazatel'stva v otnoshenii svjazi s fosforom-32. Mozhno takzhe poluchit' sil'nejshuju sistemu linij s pomoshh'ju chistogo gamma-obluchenija. Odna sistema linij proslezhena dlja gorjachih atomov otdachi i opredelena dlja fosfit-radikala. (author)

  4. A Scintillation Camera for Kinetic Studies of the Distribution of Radioactive Nuclides in the Brain; Chambre a Scintillation pour des Etudes sur la Cinetique de la Repartition des Radionucleides dans le Cerveau; Stsintillyatsionnaya kamera dlya kineticheskogo issledovaniya raspredeleniya radioaktivnykh izotopov v tkani mozga; Camara de Centelleo para Estudiar la Cinetica de la Distribucion de Radionuclidos en el Cerebro

    Energy Technology Data Exchange (ETDEWEB)

    Gross, W. [Radiological Research Laboratory, Department Of Radiology, Columbia University, New York, NY (United States); Schlesinger, E. B.; De Boves, S. [Department of Neurological Surgery, Columbia University, New York, NY (United States)

    1964-10-15

    corresponder a la situacion espacial de los contadores de centelleo. La modulacion de la intensidad del haz del osciloscopio y la supresion de la actividad de fondo facilitan la visualizacion de la distribucion de actividad. (author) [Russian] Razrabotana scintil- ljacionnaja kamera, special'no prednaznachennaja dlja izuchenija kinetiki raspredelenija radioaktivnyh izotopov v tkani mozga. Jetot pribor sostoit iz dvuh grupp, aktivirovannyh talliem kristallov NaJ razmerom 1,8 X 2,5 sm , prichem 63 kristalla kazhdoj gruppy soboany v porjadok 7 x 9 na 2 ,5 -sm centrah. Jeti gruppy m ogut byt' raspolozheny takim o'razom, chtoby odnovremenno poluchat' ob e bokovye proekcii ili odnu bokovuju i odnu za dne-perednjuju ili peredne-zadnjuju proekciju. Pole zrenija kazhdogo kristalla ogranicheno kollimatorom, so stojashhim iz 19 suzhivajushhihsja kanalov s parallel'nymi osjam i. Jeta konstrukcija imeet chuvstvitel'nost' pochti ravnuju polnoj shirote na polovine rasstojanija douslovnogo istochnika opuholi po vsem rasstojanijam do 10 cm ot perednej chasti kollimatora. Jeta chuvstvitel'nost' dostatochno shiroka, chtoby izbezhat' neradioaktivnyh zon , i v to zhe vremja dostatochno uzka , chtoby pozvolit' tochnoe nabljudenie raspredelenija aktivnosti v techenie neskol'kih minut, pri ispol'zovanii normal'nyh indikatornyh doz j o d a -131. Kazhdyj kristall opticheski s o edinen so svoim fotoumnozhitelem v obshhej upakovke. Vyhodnye impul'sy fotoumnozhitelej analizirujutsja s pomoshh'ju diskriminatorov i informacija hranitsja v cifrovoj forme v chetverti zapominajushhego ustrojstva 512-kanal'nogo analizatora vysokih impul'sov. Sovpadajushhie po vremeni impul'sy iz razlichnyh d e tektorov mogut prinimat'sja v jetoj ust anovke s neznachitel'nymi p ot er jam i . Schityvanie dannyh vozmozhno v neskol'kih formah. Mozhno poluchit' dannye v cifrovoj forme, v mashinopisnoj forme ili v vide perfokart. Poslednie mozhno vvesti obratno v pribor dlja povtornogo izuchenija. Analogichnoe schityvanie

  5. Efficiency of the Shut-Down and Safety Equipment and the Kinetic Characteristics of the G2 and G3 Reactors; Efficacite des dispositifs de secours et de securite et caracteristiques cinetiques des piles G2 et G3; Ehffektivnost' sistem avarijnoj zashchity reaktorov G.2 i G.3 i kineticheskie kharakteristiki ehtikh sistem; Caracteristicas cineticas y eficacia de los dispositivos de auxilio y de seguridad de los reactores G2 y G3

    Energy Technology Data Exchange (ETDEWEB)

    Henri, C.; Plisson, J.; Teste duBailler, A. [Centre d' Etudes Nucleaires de Saclay (France)

    1963-10-15

    dispositivos de seguridad instalados. (author) [Russian] Opyt, priobretennyj v techenie neskol'kikh let ehkspluatatsii reaktorov G.2 i G.3, daet vozmozhnost' podtverdit' vysokuyu stepen' bezopasnosti raboty semejstva reaktorov na prirodnom urane, grafite i gaze. Opisyvayutsya ustanovki avarijnoj zashity, kotorye pozvolyaet predotvrashchat', s odnoj storony, takie avarii kak prekrashchenie postupleniya ehlektroehnergii v raspredelitel'nuyu set', ostanovka tsirkulyatsii gaza, prekrashchenie podachi vody i t.d., i, s drugoj storony, takie avarii, kak razrushenie obolochki, mestnye peregrevy, poterya zhidkogo teplonositelya i t.d. Printsipial'nye skhemy dayut ob{sup y}asnenie rabote ehtikh ustanovok. Izuchaetsya, glavnym obrazom, ehlektrosnabzhenie i ''kontrol''' pri avarijnykh situatsiyakh, avarijnoe snabzhenie vodoj i tsepochka avarijnoj zashchity. Ukazyvayutsya posledovatel'nye izmeneniya i uluchsheniya ehtikh ustanovok S pomoshch'yu ehksperimental'nogo issledovaniya povedeniya reaktorov na nestatsionarnom rezhime vyyavlyayutsya vnutrenne prisushchie ehtim reaktoram kharakteristiki zashchity. Issledovaniya pozvolyayut podttverdit' prigodnost' raschetnogo metoda. (author)

  6. The Inactivation of Escherichia Coli Bacteria Labelled with Tritiated Thymidine; Inactivation de Bacteries Escherichia Coli Marquees par la Thymidine Tritiee; 0418 043d 0414 ; Inactivacion de Escherichia Coli Marcada con Timidina Tritiada

    Energy Technology Data Exchange (ETDEWEB)

    Apelgot, Sonia [Institut du Radium, Laboratoire Curie, Paris (France)

    1962-02-15

    stojkie k strepto- micinu, byli markirovany v ih DNK timidinom, mechennym tritiem. Izmerenie radioaktivnosti bylo sdelano pri pomoshhi zhidkogo scintilljacionnogo detek- tora s dvumja fotoumnozhiteljami sovpadenij. V dannyh uslovijah jeffektivnost' izmerenij ravnjalas' 5,5%, a fon - 130 kjuri/mol'. Radioaktivnye bakterii sohranjalis' v zapechatnanyh ampulah libo pri tem- perature 0 Degree-Sign C, libo pri temperature - 196 Degree-Sign C, i izuchalos' ih dal'nejshee sosto- janie. Jeti opyty pokazali, chto bakterii inaktivirujutsja funkcional'no v zavisi- mosti ot chisla rasshheplennyh atomov tritija. Inaktivacija zavisit ot tem- peratzgry, v kotoroj oni soderzhalis'. Vychislenie pokazyvaet, chto zffektiv nost' kazhdogo rasshheplennogo atoma dlja umershhvlenija bakterij ochen' neznachi- tel'na. Vychislenie kolichestva par sozdannyh pri inaktivacii ionov v bak- terii ispushhennymi beta-chasticami, poluchennymi vo vremja transmutacii atomov tritija, pokazyvaet, chto ono sravnimo s kolichestvom v sluchae s iks-luchami. Kazhetsja, chto vymiranie, vyzvannoe raspadom trutija, dolzhno byt' prjamo svjazano s proizvedinnoj ionzaciej v bakterial'noj DNK ispushhennymi beta- chasticami. (author)

  7. The determination of the thermodynamic activity of antimony in alpha-iron; Determination de l'activite thermodynamique de l'antimoine dans le fer alpha; Opredelenie termodinamicheskoj aktivnosti sur'my v al'fa-zheleze; Determinacion de la actividad termodinamica del antimonio en el hierro alfa

    Energy Technology Data Exchange (ETDEWEB)

    Tomilin, I A

    1962-01-15

    solubilidad del antimonio en el hierro alfa. Como habian obtenido las aleaciones de antimonio y hierro saturandolas por difusion y no por enfriamiento a partir del estado liquido, no observaron fusion alguna. Esta circunstancia les permitio determinar con exactitud la constante de la red cristalina de las aleaciones y la medida en que esa constante depende de la concentracion de antimonio. El limite de solubilidad determinado por datos roentgenograficos concuerda con el hallado utilizando el {sup 124}Sb. (author) [Russian] V rabote predlozhen metod opredeleniya termodinamicheskoj aktivnosti sur'my, rastvorennoj v al'fa-zheleze, osnovannyj na izuchenii ee raspredeleniya mezhdu dvumya fazami - zhidkim svintsom i tverdym zhelezom. EHtim metodom bylo najdeno, chto tverdye rastvory sur'my v al'fa-zheleze otlichayutsya polozhitel'nymi otkloneniyami ot ideal'nosti. V dovol'no shirokoj oblasti kontsentratsij sur'my ee rastvory v zheleze podchinyayutsya zakonu Genri. Byli provedeny spetsial'nye opyty po izucheniyu raspredeleniya sur'my mezhdu svintsom i zhidkim zhelezom, kotorye pokazali, chto i v zhidkom sostoyanii sistema zhelezo-sur'ma, pri nebol'shikh kontsentratsiyakh poslednej, kharakterizuetsya polozhitel'nymi otkloneniyami ot ideal'nosti. Po temperaturnoj zavisimosti aktivnosti sur'my v al'fa-zheleze vychisleny teplota ee rastvoreniya i izbytochnaya partsial'naya molyarnaya ehntropiya. Poluchennye rezul'taty ispol'zovany dlya utochneniya polozheniya linii, ukazyvayushchej predel rastvorimosti sur'my v al'fa-zheleze. Blagodarya tomu, chto splavy sur'my s zhelezom byli polucheny putem diffuzionnogo nasyshcheniya, a ne okhlazhdeniya iz zhidkogo sostoyaniya, v nikh otsutstvovala likvatsiya. EHto obstoyatel'stvo pozvolilo nadezhno opredelit' postoyannuyu reshetki splavov i zavisimost' ee ot kontsentratsii sur'my. Opredelenie predela rastvorimosti po rentgenograficheskim dannym soglasuetsya s poluchennym pri ispol'zovanii Sb{sup 124}. (author)

  8. Liquid scintillators for radiocarbon dating in archaeology; Scintillateurs liquides pour l'evaluation de Page au moyen du radiocarbone en archeologie; Zhidkie stsintillyatory dlya radiouglerodnogo datirovaniya v arkheologii; Centelladores liquidos para la determinacion de edades con carbono-14 en arqueologia

    Energy Technology Data Exchange (ETDEWEB)

    Starik, I E; Rudenko, S I; Artem' ev, V V; Butomo, S V; Drozhzhin, V M; Romanova, E N

    1962-01-15

    5500 ans represente, pour des quantites de 40 et 70 ml de scintillateur, 65 et 25 ans respectivement. Les auteurs ont effectue des mesures sur des specimens archeologiques provenant de diverses regions de l'URSS. (author) [Spanish] Con el objeto de determinar mediante carbono radiactivo la edad absoluta de muestras arqueologicas, los autores utilizan un contador de centelleo sencillo con un fotomultiplicador, sin refrigeracion. Consiguen reducir la actividad de fondo empleando un blindaje formado por laminas de acero y de plomo, procediendo a una seleccion de los impulsos segun su amplitud y construyendo el detector con materiales seleccionados y ''purificados''. A partir del carbono contenido en la muestra arqueologica, se sintetiza etil benceno. Para efectuar las mediciones, se han utilizado de 18 a 72 ml de centelleador liquido, cantidad que corresponde de 3 a 12 g de carbono en la muestra. Empleando 40 ml de centelleador, la velocidad de recuento de la actividad de fondo y la del carbono contemporaneo (sin fondo) fueron respectivamente de 23,5 y 37 impulsos/min; con 70 ml, estas velocidades fueron de 28 y 57 impulsos/min. El error estadistico correspondiente a mediciones de 48 horas de duracion de muestras de 5500 anos de edad asciende a 65 y 35 anos cuando se emplean 40 ml y 70 ml de centelleador, respectivamente. Se midieron muestras arqueologicas procedentes de diversas regiones de la Union Sovietica. (author) [Russian] Dlya opredeleniya absolyutnogo vozrasta arkheologicheskikh obraztsov po radiouglerodu ispol'zuetsya prostoj stsintillyatsionnyj schetchik s odnim fotoumnozhitelem bez okhlazhdeniya. Snizhenie fona dostigaetsya primeneniem zashchity iz sloev stali i svintsa, amplitudnoj selektsii impul'sov i vyborom ''chistykh'' materialov dlya izgotovleniya detektora. Iz ugleroda, soderzhashchegosya v arkheologicheskom obraztse, sinteziruetsya ehtilbenzol. Pri izmereniyakh ispol'zovalos' ot 18 do 72 ml zhidkogo stsintillyatora, chto sootvetstvovalo vvedeniyu ot 3

  9. Improved method for lifetime measurements; Methode perfectionnee de mesure de la duree de vie; Usovershenstvovannyj metod izmereniya vremeni zhizni; Metodo perfeccionado para medir la vida media de los estados de excitacion

    Energy Technology Data Exchange (ETDEWEB)

    Weinzierl, P; Bartl, W [Oesterreichische Studiengesellschaft fuer Atomenergie, Seibersdorf (Austria)

    1962-04-15

    entre los dos detectores. El espectro de impulsos del dispositivo sumador se hace incidir sobre un analizador de un solo canal para la seleccion de la energia deseada. El rayo {gamma} (I) se detecta en otro cristal organico. Los impulsos rapidos de ambos detectores organicos pasan a un convertidor tiempo-altura de impulsos y a un analizador multicanal. Este analizador se hace actuar como puerta mediante una coincidencia lenta entre los discriminadores de alturas de impulsos. (author) [Russian] Izmerenie vremeni zhizni yadra v vozbuzhdennom sostoyanii obychno osnovano na izmerenii otstavaniya odnogo gamma-lucha (II) po otnosheniyu k drugomu gamma-luchu (I) ili k beta-chastitse. Organicheskie stsintillyatory dayut nailuchshuyu razreshayushchuyu sposobnost' po vremeni dlya izmereniya vremeni takogo raspada, no dlya slozhnykh protsessov raspada opredelenie gamma-ehnergii predstavlyaet bol'shoe znachenie i mozhet byt' luchshe vsego dostignuto stsintillyatorami s kristallom NaI(Tl). Dlya sovmestnogo ispol'zovaniya preimushchestv detektorov togo i drugogo tipa gamma-luch (II) prezhde vsego rasseivaetsya v organicheskom kristalle (stil'ben), a rasseyannyj kvant detektiruetsya kristallom Nal(Tl). Dlya osushchestvleniya bol'shikh uglov priemki mezhdu dvumya stsintillyatorami izmerenie gamma-ehnergii dostigaetsya posle slozheniya amplitudy oboikh stsintillyatsionnykh impul'sov. Dlya obespecheniya nadezhnogo dejstviya ustanovki dlya slozheniya postupayushchie iz organicheskogo kristalla impul'sy prokhodyat prezhde vsego cherez strobiruyushchuyu skhemu, kotoraya initsiiruetsya sovpadeniem mezhdu dvumya stsintillyatorami. Spektr impul'sov, postupayushchij iz ustanovki dlya slozheniya, napravlyaetsya v odnokanal'nyj analizator dlya otbora po ehnergii. Gamma-luch (I) detektiruetsya v drugom organicheskom kristalle. Bystrye impul'sy oboikh organicheskikh stsintillyatorov napravlyayutsya v amplitudno-vremennoj preobrazovatel' impul'sov i v mnogokanal'nyj analizator. EHtot analizator

  10. A Depth-Focusing Collimator for the Investigation of the Brain Cortex; Collimateur a Focalisation Profonde pour l'Exploration de la Substance Corticale du Cerveau; Kollimator s glubinnoj fokusirovkoj dlya''issledovaniya kory golovnogo mozga; Colimador de Enfoque Profundo para Estudios de la Corteza Cerebral

    Energy Technology Data Exchange (ETDEWEB)

    Glasswestern, H. I. [Regional Hospital Board, Glasgow (United Kingdom)

    1964-10-15

    mesurer, a l'aide de {sup 133}Xe, des flux sanguins localises dans la substance corticale du cerveau. Toutefois, l'appareil permet aussi de detecter, avec des produits chimiques marques par {sup 125}l, des tumeurs et des hemorragies de la substance corticale. (author) [Spanish] El autor describe un detector que consiste en un cristal de yoduro de sodio, de 5 pulg de diametro y i de pulg de espesor, y un colimador de enfoque profundo. En principio, el colimador fue diseflado para el estudio de la circulacion sanguinea en la corteza cerebral mediante el {sup 133}Xe, pero puede utilizarse tambien con otros emisores de rayos gamma blandos, por ejemplo, el {sup 125}I. El colimador, de plomo, tiene Inverted-Question-Mark de pulg de espesor y es de tipo multicanal. El foco esta situado a 1,75 cm de la cara anterior. La respuesta en aire a una fuente puntiforme que se mueva a lo largo del eje central del colimador decrece hasta el {sup 125}I del valor maximo a {+-} 0,75 cm del foco. La respuesta en tejidos para campos alejados es considerablemente mejor que en aire debido a que los tejidos atenuan mucho la radiacion gamma blanda. El autor describe la respuesta del colimador a una fuente puntiforme situada en el aire y dentro de un craneo. El colimador se ha empleado para medir, con ayuda de {sup 133}Xe, la circulacion sanguinea en la corteza cerebral; pero mediante productos quimicos marcados con {sup 125}I, permite tambien detectar hemorragias y tumores corticales. (author) [Russian] Opisyvaetsja detektor , sostojashhij iz kristalla iodistogo natrija dimetrom 12,5 sm i tolshhinoj 6,2 mm kollimatora s glubinnoj fokusirovkoj. Kollimator pervonachal'no prednaznachalsja dlja issledovanija krovoobrashhenija v kore golovnogo m o zga s pomoshh'ju ks en on a -133 , no mozhno takzhe ispol'zovat' i drugie mjagkie gamma-izluchajushhie i zo topy, naprimer j o d -125. Kollimator so svincovym korpusom tolshhinoj 6m m javljaetsja mnogokanal'nym. Fokus nahoditsja na rasstojanii 1,75 sm ot

  11. Technical Developments in the USAEC Process Radiation Development Program; Etudes technologiques dans le cadre du programme de mise au point d'applications industrielles des rayonnements de la CEA-EU; Issledovaniya v oblasti promyshlennogo primeneniya izluchenij, vkhodyashchie v programmu komissii po atomnoj ehnergii USAEC; Progresos tecnicos en el programa de la USAEC para el fomento de la irradiacion industrial

    Energy Technology Data Exchange (ETDEWEB)

    Machurek, J. E.; Stein, M. H. [Division of Isotopes Development, USAEC, Washington, DC (United States)

    1963-11-15

    ispol'zovanie ioniziruyushchikh izluchenij v promyshlennosti. Provedeno chetyrnadtsat' takikh issledovanij, rezul'taty nekotorykh iz nikh izlozheny v obshchikh chertakh v dannoj rabote, ostal'nye izlagayutsya bolee podrobno - v drugikh stat'yakh trudov. Temy issledovanij vklyuchayut: 1. Prigotovlenie kombinatsij derevo-plastik, ispol'zuya gamma-izluchenie dlya indutsirovaniya polimerizatsii. 2. Ispol'zovanie beta-izlucheniya produktov deleniya dlya gidrogenizatsii uglya, i ego produktov s tsel'yu polucheniya zhidkogo uglevodorodnogo topliva. 3. Poluchenie poluprovodnikovykh priborov s formirovaniem zadannogo prostranstvennogo raspredeleniya primesej v zavisimosti ot legirovaniya putem nejtronnykh prevrashchenij. 4. Vyzvannaya izlucheniem polimerizatsiya ehtilena i sopolimerov. 5. Osnovnye issledovaniya mekhanizmov i kinetiki reaktsij, vyzvannykh izlucheniem. 6. Radiatsionno-khimicheskie protsessy pri ftorirovanii razlichnykh aromaticheskikh soedinenij. 7. Ispol'zovanie polifunktsional'nykh monomerov dlya intensifikatsii radiatsionnogo sshivaniya poliehtilena, polipropilena, poliizobutilena i atsetattsellyulozy. 8. Vliyanie nabukhaniya, deformatsii i temperatury na fizicheskie i khimicheskie svojstva polimerov, poluchennykh s pomoshch'yu radiatsii. 9. Vliyanie strukturnykh faktorov na radiatsionnye izmeneniya v polimerakh, privodyashchie k graftsopolimerizatsii. 10. Ispol'zovanie yadernykh izluchenij dlya modifikatstsii tekstil'nykh materialov. 11. Reaktsii, vyzvannye izlucheniem kriptona-85. 12. Podgotovka ''Spravochnika po radiatsii''. 13. Ispol'zovanie metalloorganicheskoj svyazi dlya gamma-dozimetrii pri bol'shikh moshchnostyakh dozy. 14. Razrabotka dozimetra s solnechnym ehlementom. (author)

  12. Optimization of Gamma-Ray Counting and Spectrometry in Biomedical Tracer Studies; Optimisation du Comptage et de la Spectrometrie des Rayons Gamma dans des Etudes Biomedicales Faites a l'Aide de Traceurs; Optimizatsiya gamma-scheta i spektrometrii gamma-luchej v biomeditsinskikh issledovaniyakh s pomoshch'yu indikatorov; Optimizacion del Recuento y de la Espectrometry Gamma en los Estudios Biomedicos con Indicadores

    Energy Technology Data Exchange (ETDEWEB)

    Guinn, V. P. [General Dynamics Corporation, San Diego, CA (United States)

    1965-10-15

    rezul'taty jetih raschetov opti- mizacii otschityvanija imejut dvojnuju pol'zu. V osnovu raschetov byli polozheny prostye gipotezy, osnovannye prakticheskih bio- medicinskih soobrazhenijah: 1) malyj razmer prob (ne bolee 10 ml); 2) ogranichennoe vremja' otschityvanija (ne bolee 20 min); 3) nebol'shie dopustimye periody raspada (ne bolee treh sutok) i 4) ispol'zovanie imejushhegosja v prodazhe oborudovanija dlja otscheta i zashhity. Na jetoj osnove byli opredeleny naibolee chuvstvitel'nye metody otscheta dlja kazhdogo iz vysheupomjanutyh radioizotopov, a takzhe dlja ih par i troek. Uchityvalis' sledujushhie peremennye velichiny otscheta: 1) tip kristalla NaJ (T1), a imenno cel'nyj ili s kanalom, 2) razmer kristalla NaJ (T1)-do5h 5 djujmov i 3) tip izmeritel'nyh priborov: prostaja pereschetnaja shema, odnokanal'nyj i mnogokanal'nyj analizator amplitudy impul'sov. Dlja kazhdogo optimal'nogo uslovija otscheta podschitany minimal'naja ulovimaja udel'naja aktivnost' proby, a takzhe urovni ee, neobhodimye dlja sobljudenija statisticheskoj pra- vil'nosti (vyrazhennoj v vide standartnyh otklonenij) v predelah {+-}20, {+-}10, {+-}5 i {+-}2% . Dlja celogo rjada pokazatel'nyh sluchaev raschetnye predely byli sopostavleny s jeksperi- mental'nymi. Osoboe vnimanie udeljalos' nailuchshim uslovijam ponizhenija do minimuma doli izluchaemyh svincom rentgenovskih luchej, obratnogo rassejanija gamma-luchej, pikov utechki, chisla beta-chastic v probe i tormoznogo izluchenija. (author)

  13. A novel time-to-pulse height converter for fast-neutron time-of-flight techniques; Nouveau convertisseur temps-amplitude d'impulsions pour les mesures du temps de vol des neutrons rapides; Novyj vremya-amplitudnyj preobrazovatel' impul'sov dlya izmereniya vremeni proleta bystrykh nejtronov; Nuevo convertidor tiempo-altura de impulsos para tecnicas de tiempo de vuelo de neutrones rapidos

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, J [Physikalisches Staatsinstitut, Hamburg, Federal Republic of Germany (Germany)

    1962-04-15

    } s con coincidencias gamma obtenidas de una fuente de {sup 60}Co y utilizando cristales plasticos NE 102, y de 2{tau} = 1,4 {center_dot} 10{sup -9} con coincidencias gamma de 511 KeV y utilizando cristales de Nal (Te). El metodo se utilizo tambien aplicando tecnicas de haces pulsantes. En la experiencia realizada se obtuvo, a partir de una radiofrecuencia pulsadora, una sucesion de impulsos muy aguzados, con una frecuencia de 8 MHz, que se transmitio a las placas de la valvula E80T. Se obtuvo un tiempo de resolucion de 2{tau} = 1,1 {center_dot} 10{sup -9} s con neutrones de 4 MeV, utilizando cristales plasticos de 0,7 pulgadas de largo. Normalmente la region de respuesta lineal fue de 30 ns (30 {center_dot} 10{sup -9} s), pero se consiguio aumentarla hasta 120 ns. (author) [Russian] Opisyvaetsya ehlektronnyj vremya-amplitudnyj preobrazovatel' impul'sov s ispol'zovaniem metoda umnozheniya perekryvayushchikhsya impul'sov vmesto obychnogo metoda ikh slozheniya. EHto dostigaetsya polucheniem sovpadeniya linejnogo piloobraznogo impul'sa s rezko ogranichennym igol'chatym impul'som. Piloobraznyj impul's postupaet na reshetku otklonyayushchej puchok lampy (E80T), a igol'chatyj impul's napravlyaetsya na otklonyayushchie plastiny, gde on otkryvaet lampu tol'ko v techenie promezhutka vremeni priblizitel'no 5 x 10{sup -9} sekund. Plastina poluchaet zaryad, proportsional'nyj raznitse vo vremeni mezhdu nachalom piloobraznogo i nachalom igol'chatogo impul'sov. Posylaemyj plastinoj impul's rasshiryaetsya i usilivaetsya i amplituda ego sootvetstvuet velichine raznitsy vo vremeni. EHtim metodom udalos' poluchit' razreshayushchuyu sposobnost' po vremeni, ravnuyu {tau} = 7 x 10{sup -12} sekundam s iskusstvennymi impul'sami, {tau} = 3 x 10{sup -10} sekundam s sovpadeniyami dlya kobal'ta-60 pri ispol'zovanii plasticheskogo kristalla NE 102, i {tau} = 1,4 x 10{sup -9} sekundy pri sovpadeniyakh v 511 kehv pri ispol'zovanii kristallov Nal (Te). EHtot metod byl ispol'zovan takzhe v sochetanii

  14. Thermal Annealing of Paramagnetic Defects Induced by Gamma Irradiation in (NH{sub 4}){sub 2}SO{sub 4} and (ND{sub 4}){sub 2}SO{sub 4} Single Crystals: Experimental Verification of the Theory of Fletcher and Brown; Recuit Thermique des Defauts Paramagnetiques Induits par Irradiation Gamma dans des Monocristaux de (NH{sub 4}){sub 2}SO{sub 4} et (ND{sub 4}){sub 2}SO{sub 4}: Verification Experimentale de la Theorie de Fletcher et Brown; 0422 0415 0420 041c 0414 ; Regeneracion Termica de los Defectos Paramagneticos Inducidos por Irradiacion Gamma en Monocristales de (NH{sub 4}){sub 2}SO{sub 4} y (ND{sub 4}){sub 2}SO{sub 4}: Verificacion Experimental de la Teoria de Fletcher y Brown

    Energy Technology Data Exchange (ETDEWEB)

    Calusaru, A.; Barbur, I.; Ursu, I. [Institut de Physique Atomique, Bucarest (Romania); Universite ' Babes' , Cluj (Romania)

    1965-04-15

    ,996 y 2,0032, respectivamente. El estudio de la regeneracion por recocido del primer radical en el intervalo 60 Degree-Sign -170 Degree-Sign C revela la existencia de una cinetica con un solo rellano correspondiente a una recombinacion total de los radicales. Se ha podido establecer, para cada isoterma, la ecuacion correspondiente utilizando la funcion de errores deducida por Fletcher y Brown considerando el modelo de recombinacion de pares inicialmente correlacionados (y luego liberados) segun un proceso aleatorio. La concordancia entre los resultados experimentales y la funcion se obtiene corrigiendo esta mediante un factor alfa. La curva compuesta de recocido se ajusta muy bien a la funcion de errores corregida. Aplicando el metodo fenomenologico de Fletcher y Brown para calcular la energia de activacion, se ha hallado el valor de 1,594 eV, correspondiente al primer radical en el (NH{sub 4}){sub 2}SO{sub 4}. Basandose en la variacion del coeficiente de difusion con la temperatura, se ha determinado el valor de 1,592 eV para la misma energia de activacion. Aplicando el metodo de Vand-Primack se ha hallado el valor de 1,45 eV, menor que los dos anteriores. Se estima, en conclusion, que el modelo de recombinacion de pares correlacionados segun un proceso aleatorio es aplicable en la formula dada por la teoria cuando la interaccion de las especies formadas con la red es bastante debil; en esas condiciones, los pares correlacionados inicialmente pueden liberarse. (author) [Russian] V obluchennyh kristallah (NH{sub 4}){sub 2}SO{sub 4} i (ND{sub 4}){sub 2}SO{sub 4} s pomoshh'ju metoda rezonansa spina jelektrona byli identificirovany dva paramagnitnyh vida. Konstanta g pervogo radikala sostavljaet 2,014 i vtorogo-2,020 dlja sul'fata ammonija s vodorodom; te zhe konstanty dlja dejterirovannogo kristalla sostavljajut 1,9996 i 2,0032. Izuchenie otzhiga pervogo radikala pri temperaturah mezhdu 60 Degree-Sign i 170 Degree-Sign C pokazalo, chto v dannom sluchae imeet mesto

  15. Dispersion Curves for Phonons in Diamond; Courbes de Dispersion des Phonons dans le Diamant; Krivye dispersii dlya fononov v almaze; Curvas de Dispersion de los Fonones en el Diamante

    Energy Technology Data Exchange (ETDEWEB)

    Warren, J. L.; Wenzel, R. G.; Yarnell, J. L. [Los Alamos Scientific Laboratory, Los Alamos, NM (United States)

    1965-04-15

    recien mencionados, la tienen menos en el caso del diamante. (author) [Russian] Trehosnyj difrakcionnyj spektrometr nejtronov na Losalamosskom reaktore ''Omega Vest'' ispol'zovalsja dlja izmerenija nekotoryh krivyh dispersii dlja rasprostranenija fononov v napravlenijah [100] i [111] v almaze . Vse iz merenija provodilis' pri komnatnoj temperature. Obrazec predstavljal soboj korichnevyj promyshlennyj almaz tipa Na vesom 242,8 karat (48,56 grammov). Izuchenie javlenij difrakcii nejtronov pokazalo, chto almaz sostoit iz bol'shogo edinichnogo kristalla s mozaichnym razbrosom v razmere M Degree-Sign polnoj shiriny pri polumaksimume, pljus dvumja nebol'shimi oblastjami, razorientirovannymi na 3 - 5 Degree-Sign . Spektrometr programmirovalsja dlja operacii ''postojannaja''. Vo vseh sluchajah jenergija padajushhih nejtronov byla postojannoj, i rassejannye nejtrony terjali jenergiju. Dostatochnaja intensivnost' pri jenergii bombardirovki, dostatochno bol'shoj dlja vozbuzhdenija opticheskih form almaza, byla dostignuta v rezul'tate ispol'zovanija otrazhenija (1122) berillievogo monohromatora. K trudnostjam provedenija jeksperimentov, pomimo trudnostej, voznikajushhih v svjazi s nalichiem ochen' vysokih chastot fononov v almaze, otnositsja vozniknovenie anomal'nyh pikov, chto zatrudnjaet raspoznavanie tochek poljarizacii. Schitaetsja, chto neopredelennosti v izmerennyh chastotah sostavljajut velichinu porjadka 2-3 procentov. Naibolee razitel'nym rezul'tatom jetih izmerenij javljaetsja podtverzhdenie predpolozhenij, osnovannyh na dannyh otnositel'no pogloshhenija infrakrasnoj oblasti spektra i otnositel'no udel'nogo tepla, chto almaz ne javljaetsja gomologom s kremniem i germaniem. Otsutstvie sootvetstvija projavljaetsja v osnovnom v povedenii poperechnyh akusticheskih vetvej, kotorye v sluchajah vyrazhenija ih v sootvetstvujushhih privedennyh edinicah po svoej chastote pochti v dva raza vyshe v almaze, chem v kremnii i germanii. Ostal'nye nabljudaemye krivye dispersii dlja almaza

  16. Retention in Solid KIO{sub 3} Activated with Fast and Slow Neutrons; Retention dans KIO{sub 3} Solide Active par des Neutrons Rapides et des Neutrons Lents; 0423 0414 0415 0420 0416 0410 041d 0418 0415 0412 0422 0412 0415 0420 0414 041e 041c KIO{sub 3}, 0410 041a 0422 0418 0412 0418 0420 041e 0412 0410 041d 041d 041e 041c 0411 042b 0421 0422 0420 042b 041c 0418 0418 041c 0415 0414 041b 0415 041d 041d 042b 041c 0418 041d 0415 0418 0422 0420 041e 041d 0410 041c 0418 ; Retencion en KIO{sub 3} Solido Activado con Neutrones Rapidos y Lentos

    Energy Technology Data Exchange (ETDEWEB)

    Aten, A.H.W. Jr.; Lindner-Groen, M.; Lindner, L. [Instituut voor Kernphysisch Onderzoek, Amsterdam (Netherlands)

    1965-04-15

    cristal, y presentar caracteristicas identicas para los diferentes isotopos. Para comprobar estas hipotesis se ha realizado una serie de experimentos en los que se activo KIO{sub 3} solido con neutrones rapidos y termicos. En el caso de los neutrones rapidos, la retencion de {sup 128}I fue sensiblemente mayor que la de {sup 126}I, pero la retencion de {sup 128}I alcanzada con los neutrones termicos fue aun mas elevada que la obtenida con los neutrones rapidos. Este hecho indica que, aparte del esquema de desintegracion, la energia de retroceso tambien puede constituir un factor determinante de la retencion. Tambien difieren los efectos del recocido en el {sup 128}I y en el {sup 126}I (obtenidos ambos con neutrones rapidos). Por tratamiento postirradiatorio a temperaturas de hasta 100 Degree-Sign C, la retencion de ambos isotopos referida a la actividad total aumento en la misma proporcion, esto es, la diferencia de retencion permanecio constante. Por tanto, la parte de la fraccion de {sup 126}I reducida por el proceso de retroceso que excede de la fraccion de {sup 128}I reducida, resulta mucho menos afectada por el calentamiento que la fraccion reducida de ambos isotopos. Es evidente que solo un modelo bastante detallado permite explicar ese comportamiento quimico tan complicado del atomo radiactivo de retroceso. (author) [Russian] Prostaja model' vzaimodejstvij jader otdachi v tverdom tele predpolagaet, chto osnovnoe (neotozhzhennoe) uderzhanie dolzhno pokazat' izotopnye jeffekty (kotorye, verojatno, byli by svjazany so sposobom poteri jadrom produkta svoej izbytochnoj jadernoj jenergii) i chto jeto kolichestvo dolzhno byt' nechuvstvitel'nym k usloviju kristallicheskoj reshetki. S drugoj storony, otzhig v jetoj prostoj modeli dolzhen zaviset' ot uslovija (i predvaritel'noj obrabotki) kristalla, no pokazyvat' to zhe samoe povedenie dlja razlichnyh izotopov . Proverka jetih argumentov daetsja posredstvom provedenija serii opytov, v kotoryh tverdyj KJO{sub 3} aktivirovalsja

  17. The Role of Non-Destructive Testing in the Los Alamos Reactor Programme; Role des Essais Non Destructifs dans le Programme de Reacteurs de los Alamos; Rol' nedestruktivnykh ispytanij materialov v Los-Alamosskoj reaktornoj programme; Papel de los Metodos de Ensayo No Destructivo en el Programa de Reactores de Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Tenney, G. H. [University of California, Los Alamos Scientific Laboratory, Los Alamos, NM (United States)

    1965-10-15

    prokatannogo lista iz slitka. Osushhestvljalsja takzhe kontrol' za svarnymi shvami. Byl razrabotan metod proverki potenciala jelektroda dlja kontrolja zolotyh poverhnostej dlja obnaruzhenija soderzhashhihsja zagrjaznenij. Osnovnaja koncepcija LARJeRP (Los-Alamosskij reaktornyj jeksperiment s rasplavlennym plutoniem) zakljuchaetsja v ispol'zovanii v kachestve topliva skoree zhidkogo, chem tverdogo metallicheskogo plutonija. Tantalovye kapsuly soderzhali toplivo. Byli ispol'zovany novye metody kontrolja bez razrushenija dlja proverki prochnosti osnovnogo materiala i svarok vo vremja proizvodstva kapsul, a takzhe dlja izuchenija kapsul, zapolnennyh plutoniem do, vo vremja i posle kontrolja metodom ohlazhdennoj plavki. Za jeksperimentom po perekachke rasplavlennogo plutonija nabljudali s pomoshh'ju radiograficheskih metodov, vkljuchaja gamma- luchi, svjazannye s konturom televedenija. Dlja RJeUVT (Reaktornyj jeksperiment pri ul'tra-vysokojtemperature), kotoryj v nastojashhee vremja nahoditsja v stadii stroitel'stva, byli provedeny mikroradiograficheskie i jelektronno-mikroskopicheskie issledovanija na sharikah diametrom 150 mikron iz karbida urana, pokrytyh pirouglerodom, dlja ocenki migracii urana kak funkcija temperatury. Kolichestvo i odnorodnosti uranovoj zagruzki v grafitovyh jelementah RJeUVT opredeljajutsja s pomoshh'ju special'no skonstruirovannyh scintilljacionnyh schetchikov. Primerno 90% raboty po jetoj teme ranee ne bylo opublikovano. (author)

  18. Performance Characteristics of the Experimental Boiling Water Reactor from 0 to 100 MW(t); Performances de l'EBWR de 0 a 100 MW; Rabochaya kharakteristika ehksperimental'nogo kipyashchego reaktora EBWR pri moshchnosti 0 - 100 mgvt.; Rendimiento del reactor experimental de agua hirviente (EBWR) entre 0 y 100 MW

    Energy Technology Data Exchange (ETDEWEB)

    Iskenderian, A.; Lipinski, W. C.; Petrick, M.; Wimunc, E. A. [Argonne National Laboratory, Argonne, IL (United States)

    1963-10-15

    entonces de comportarse como reactor de agua hirviente de ciclo directo; en cierto modo, funciona como reactor de ciclo doble y circulacion natural. (author) [Russian] 25 maya 1962 goda Argonnskaya natsional'naya laboratoriya poluchila razreshenie KAEH SSHA na ehkspluatatsiyu reaktora EBWR na moshchnosti 100 mgvt. Administrativnoe razreshenie na ehkspluatatsiyu reaktora bylo predostavleno sistemoj garantij. Mezhdunarodnogo agentstva po atomnoj ehnergii 11 iyulya 1961 goda. 15 noyabrya 1962 goda byl dostignut uroven' moshchnosti v 100 mgvt. 6 dekabrya 1962 goda ehksperimental'naya programma byla zakonchena. Odnoj iz osnovnykh tselej ee byla tshchatel'naya proverka reaktora dlya polucheniya dannykh i informatsii rabochej kharakteristiki ehtogo tipa reaktora. Ehta programma byla pervoj programmoj takogo roda i pervoj vypolnennoj programmoj. Dlya polucheniya nuzhnykh dannykh neobkhodimo bylo razrabotat' mnogie novye pribory. TSel' byla dostignuta, polucheno mnogo novykh dannykh o rabochej kharakteristike kipyashchego reaktora s estestvennoj tsirkulyatsiej. Tak,naprimer, poluchena informatsiya otnositel'no skorosti potoka tsirkulyatsii v zamknutom tsikle, predelov separatsii zhidkogo para (vydelenie para v osadok v spusknoj trube i unos zhidkosti ehflu- entom para), nedogreva, lokalizatsii dejstvitel'noj poverkhnosti razdela v reaktore i ee svyazi s urovnem vodnoj kolonki, skorosti razrusheniya para v spusknoj trube, pustotnykh koehffitsientov, reaktivnoj sposobnosti H{sub 3}BO{sub 3}, temperaturnykh koehffitsientov, ispol'zovaniya sterzhnej iz bora dlya tselej kontrolya, ispol'zovaniya svezhikh toplivnykh ehlementov, peredatochnykh funktsij,analiza shuma, nekotorykh izmerenij potoka, stabil'nosti i t.d. Krome togo, byli polucheny dannye o povedenii i tselostnosti nekotorykh reaktornykh komponentov i sistem, takikh, kak bornokislaya kontrol'naya reaktsiya, urovni radiatsii, raspredelenie produktov korrozii, vykhod iz stroya oborudovaniya, toplivo i reguliruyushchie sterzhni i t

  19. Molecular Dynamics Investigated by Neutron Scattering; Etude de la Dynamique Moleculaire au Moyen de la Diffusion des Neutrons; 0418 0421 0421 041b 0415 0414 041e 0412 0410 041d 0418 0415 041c 041e 041b 0415 041a 0423 041b 042f 0420 041d 041e 0419 0414 0418 041d 0410 041c 0418 041a 0418 0421 041f 041e 041c 041e 0429 042c 042e 0420 0410 0421 0421 0415 042f 041d 0418 042f 041d 0415 0419 0422 0420 041e 041d 041e 0412 ; Estudio de la Dinamica Molecular por Dispersion Neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Janik, J. A. [Institute for Nuclear Physics, Cracow (Poland)

    1965-06-15

    spektroskopii i izmerenij udel'noj teploemkosti. Rassmatrivaetsja takzhe vopros o predele vozmozhnosti ocenki vrashhenija na osnovanii rezul'tatov izmerenija obshhih nejtronnyh sechenij. Krome togo proizvoditsja sravnenie vrashhatel'noj dinamiki grupp NH{sub 4} v NH{sub 4}CIO{sub 4} i grupp H{sub 3}O v H{sub 3}OCIO{sub 4} na osnove rezul'tatov jeksperimentov po neuprugomu rassejaniju nejtronov. Svobodnoe vrashhenie gruppy NH4 v hlornokislom ammonii bylo polucheno dazhe pri takih nizkih temperaturah, kak temperatura zhidkogo azota. Dlja H{sub 3}OCIO{sub 4} bylo obnaruzheno krutil'noe kolebanie gruppy N3O s chastotoj 497 sm{sup 1} . Takim obrazom, nesmotrja na identichnost' kristallicheskih reshetok NH{sub 4}CIO{sub 4} i H{sub 3}OCIO{sub 4}, dinamika grupp NH{sub 4} i H{sub 3}O javljaetsja razlichnoj. Jeti rezul'taty sravnivajutsja s rezul'tatami, poluchennymi s pomoshh'ju spektroskopii Ramana i jadernogo magnitnogo rezonansa. I, nakonec, rjad drugih veshhestv rassmatrivaetsja s tochki zrenija molekuljarnoj dinamiki. (author)

  20. Investigation of the Dynamics Of NH{sup +}{sub 4} and H{sub 2}O Molecular Groups in Crystals; Etude de la Dynamique des Groupes Moleculaires NH{sup +}{sub 4} et H{sub 2}O dans les Cristaux; 0418 0421 0421 041b 0415 0414 041e 0412 0410 041d 0418 0415 0414 0418 041d 0410 041c 0418 041a 0418 041c 041e 041b 0415 041a 0423 041b 042f 0420 041d 042b 0425 0413 0420 0423 041f 041f NH{sup +}{sub 4} H H{sub 2}O 0412 041a 0420 0418 0421 0422 0410 041b 041b 0410 0425 ; Estudio de la Dinamica de los Grupos Moleculares NH{sup +}{sub 4} Y H{sub 2}O en Cristales

    Energy Technology Data Exchange (ETDEWEB)

    Bajorek, A.; Machehina, T. A.; Parlin' Ski, K. [Ob' edinennyj Institut Jadernyh Issledovanij, Dubna, SSSR (Russian Federation)

    1965-06-15

    fazovymi perehodami. Nesmotrja na razlichie struktur issleduemyh veshhestv, poluchaemye spektry pri temperature zhidkogo azota okazyvajutsja pohozhimi drug na druga: kak pravilo, nabljudajutsja dva pika - pervyj v oblasti peredach jenergii 15 - 20 mjev, drugoj v oblasti 35 - 70 mjev, svjazannyj s torsionnymi kolebanijami ammonievyh ionov. Intensivnost' pikov zavisit ot struktury issleduemyh veshhestv i umen'shaetsja s uvelicheniem temperatury obrazca. Obnaruzheno, chto intensivnost' uprugoj chasti spektra pri nekotoryh fazovyh perehodah sovershaet skachok (v sluchajah NH{sub 4}I, NH{sub 4}NO{sub 3} i (NH{sub 4}){sub 2}SO{sub 4}). S uvelicheniem temperatury v NH{sub 4}Cl, NH{sub 4}Br, (NH{sub 4}){sub 2}(COO){sub 2} voznikaet dopolnitel'nyj pik, sdvinutyj v storonu men'shih jenergij ot pika zatormozhennogo vrashhenija. Spektry nejtronov, rassejannyh na kristallah, soderzhashhih kristallizacionnuju vodu, takzhe shozhi mezhdu soboj. V spektrah nabljudajutsja tri gruppy pikov, svjazannyh s opticheskimi kolebanijami i zatormozhennym vrashheniem molekul vody. (author)

  1. Multidimensional Gamma-Ray Spectrometry and its Use in Biology; La Spectrometry Gamma Multidimensionnelle et son Application en Biologie; Mnogomernaya spektrometriya gamma-luchej i ee ispol'zovanie v biologii; La Espectrometria Gamma Multidimensional y su Empleo en Biologia

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, J. M.; Kornberg, H. A. [Battelle Memorial Institute, Pacific Northwest Laboratory, Richland, WA (United States)

    1965-10-15

    nahodjashhim sebe osoboe primenenie v biologii metodom izmerenija radioizotopov. Jetot instrumental'nyj opyt daet vozmozhnost' neposredstvenno vyjavit' i izmerit' otdel'nye gamma-izluchateli v slozh- nyh smesjah radioizotopov v razlichnyh matricah prob bez predvaritel'noj himicheskoj ob- rabotki. Sistema obnaruzhenija skonstruirovana tak, chtoby obespechit': bol'shuju chuvstvi- tel'nost' blagodarja ispol'zovaniju dvuh bol'shih kristallicheskih detektorov iz NaJ (T1) (diametrom 6 i tolshhinoj 4 djujma); bol'shuju selektivnost' blagodarja ispol'zovaniju metoda scheta sovpadenij, pozvoljajushhego otdeljat' drug ot druga spektry gamma-luchej, pol'zujas' harakteristikami gamma-raspada kazhdogo radioizotopa v otdel'nosti; nakonec, chrezvychajno nizkij fon, a takzhe sokrashhenie komptonovskoj interferencii posredstvom okruzhajushhego pribor detektora antisovpadenij s kol'cevym kanalom (sostojashhego iz kristalla NaJ (T1) tolshhinoj 11,5 djujma s otverstiem diametrom 6,5 djujma). Pri pomoshhi 4096-kanal'nogo mnogomernogo analizatora dva sovpadajushhih gamma-lucha razreshajutsja po svoim jenergijam i zanosjatsja dlja hranenija v ploskost' 64 h 64-kanal'noj pamjati, togda kak nesovpadajushhie sobytija hranjatsja tol'ko na osjah pamjati. Jeto jeffektivnym obrazom sokrashhaet fon i komp- tonovskie interferencii na neskol'ko porjadkov i vmeste s tem znachitel'no uluchshaet sele- ktivnost' . Neposredstvennoe gamma-spektrometricheskoe izmerenie radioizotopov, nahodjashhihsja v nichtozhno malyh kolichestvah v biologicheskih probah, znachitel'no zatrudnjaetsja iz-za pri- sutstvija otnositel'no bol'shih kolichestv prirodnogo kalija-40, gamma-radiacija kotorogo s jenergiej 1,47 Mjev meshaet izmerenijam. Poskol'ku bol'shaja chast' radioizotopov raspa- daetsja s kaskadnoj jemissiej dvuh ili neskol'kih gamma-luchej, novyj metod daet vozmozh- nost' provodit' neposredstvenno selektivnye izmerenija i rasshirjat' krug primenenija jetogo metoda. Tak, naprimer, natrij-22 (radioizotop, vstrechajushhijsja

  2. Interesting Developments in UO{sub 2} Technology; Progres interessants dans la technologie du bioxyde d'uranium; Interesnye usovershenstvovaniya tekhnologii UO{sub 2}; Recientes progresos en la tecnologia del UO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, J. A.L. [Atomic Energy of Canada Ltd., Chalk River, Ontario (Canada)

    1963-11-15

    permitiran determinar si las nuevas formas de combustible pueden ofrecer alguna ventaja economica. Mientras tanto, el continuo perfeccionamiento de las barras combustibles de UO{sub 2} sinterizado en geometrias simples dara lugar a una renida competencia. (author) [Russian] Sejchas, kogda neskol'ko reaktorov, v kotorykh toplivom sluzhit UO{sub 2}, nakhodyatsya v postoyannoj ehkspluatatsii, khoroshie radiatsionnye -svojstva UO{sub 2} ne nuzhdayutsya v dokazatel'stve. Priyatno uznavat' o tom, chto vazhnye usovershenstvovaniya eshche poyavlyayutsya. Naibolee znachitel'nom za poslednee vremya yavilos' otkrytie sotrudnikami istituta Behttely ochen' vysokoj teploprovodnosti otdel'nogo odinochnogo kristalla UO{sub 2} pri povyshennykh temperaturakh. Provedennoe v svyazi s raskhozhdeniem mnenij po ehtomu voprosu obluchenie v Chok-Rivere pokazalo, chto bol'shie zerna, obrazuyushchiesya v rabotavshikh toplivnykh ehlementakh, ne obyazatel'no obladayut ehtoj povyshennoj provodimost'yu. Ehksperimenty nashej laboratorii pokazali, chto povyshenie imeet mesto tol'ko v podstekhiometricheskikh soedineniyakh i malo zavisit, esli voobshche zavisit, ot otsutstviya granits zeren. Bezuslovno, vysokaya provodimost' mozhet byt' poluchena v polikristallicheskikh spekshikhsya materialakh putem regulirovaniya stekhiometrii. Davno izvestno, chto udlinenie obolochki mozhno umen'shit', esli izgotovit' tabletki ieh UO{sub 2} s uglubleniyami na tortsovykh poverkhnostyakh. Pozzhe bylo pokazano, chto smeshcheniyu topliva v pustoe prostranstvo v kontse trubki s tabletkami meshaet diametral'noe rasshirenie topliva i ego mekhanicheskoe vzaimodejstvie s obolochkoj. Samym bol'shim dostizheniem v otnoshenii svedeniya k minimumu rasshireniya obolochki yavilos' uyasnenie togo, chto prodol'noe, i diametral'noe rasshireniya vzaimosvyazany cherez posredstvo ob{sup e}mnogo rasshireniya topliva, goryachaya serdtsevina kotorogo dovol'no plastichna. Rasshirilis' nashi prakticheskie znaniya faktorov, opredelyayushchikh

  3. Inelastic Neutron Scattering from Doped Germanium and Silicon; Diffusion Inelastique des Neutrons dans du Germanium et du Silicium Contenant une 'Impurete'; Neuprugoe rasseyanie nejtronov na germanii i kremnii s prisadkoj; Dispersion Inelastica de Neutrones en Germanio y Silicio Deliberadamente Impurificados

    Energy Technology Data Exchange (ETDEWEB)

    Dolling, G. [Chalk River Nuclear Laboratories, Chalk River, ON (Canada)

    1965-04-15

    experimental. En los casos mas favorables, esta exactitud (relativa) alcanza al 0,5% del valor de la frecuencia, y llega hasta 2,0 Degree-Sign Inverted-Exclamation-Mark o tratandose de algunos modos opticos longitudinales en el silicio. (author) [Russian] Normal'nye formy kolebanija chistyh poluprovodnikov germanija i kremnija shiroko izuchalis' s pomoshh'ju kogerentnogo odnofononnogo rassejanija medlenny nejtronov na mono-kristallicheskih obrazcah. V dannom doklade opisyvajutsja analogichnye jeksperimenty, vypolnennye 1) s germaniem s bol'shoj prisadkoj ( Tilde-Operator 0,1%) a) mysh'jaka i '') galija, a takzhe 2) s kremniem s fosfornoj prisadkoj. V kazhdom sluchae kontrol'nye jeksperimenty provodilis' na kristallah vysokoj chistoty. Vse izmerenija vypolnjalis' na trehosnom kristallicheskom spektrometre v laboratorijah v Chok- River. Kak izvestno, postojannaja uprugosti C{sub 44} dlja germanija v znachitel'noj stepeni zavisit ot koncentracii prisadki, i pojetomu nekotorye poperechnye akusticheskie koljobanija (TA) s bol'shoj dlinoj volny izuchalis' s cel'ju vyjasnenija nalichija takih jeffektov v dispergirujushhej oblasti. Drugie TA kolebanija, chastoty kotoryh mozhno izmerjat' s vysokoj stepen'ju tochnosti, takzhe izuchalis' v oboih materialah s cel'ju vozmozhno bolee tochnoj proverki nebol'shih jeffektov, kotorye mozhno bylo by pripisat' nalichiju izbytka jelektronov ili dyrok. Osobenno tshhatel'no izuchalis' kolebanija so sledujushhimi volnovymi vektorami (aq/2{pi}, gde a -storona kubicheskoj jelementarnoj jachejki): 1) v germanii (1; 0; 0); 2) v kremnii (0.85; 0.85; 0) i (0.3; 0;0). Mozhno bylo by predpolozhit', chto takie normal'nye kolebanija projavjat neobychnye cherty v kristallah n-nogo tipa, poskol'ku dlja rassejanija jelektronov mezhdu sosednimi minimumami zon provodimosti potrebovalos' by vzaimodejstvie dlja sohranenija {sup i}mpul'sa kristalla{sup .} Rezul'taty vo vseh sluchajah byli otricatel'nymi, t.e. v predelah tochnosti jeksperimentov ne nabljudalos' nikakih

  4. Thermal Vibrations of Beta-Brass and the Order-Disorder Transition; Vibrations Thermiques dans le Laiton Beta et Transformation Ordre-Desordre; Teplovye kolebaniya beta-latuni i perekhod iz uporyadochennogo sostoyaniya v razuporyadochennoe; Vibraciones Termicas del Laton Beta y Transicion Orden-Desorden

    Energy Technology Data Exchange (ETDEWEB)

    Dolling, G.; Gilat, G. [Chalk River Nuclear Laboratories, Chalk River, ON (Canada)

    1965-04-15

    reciproco, que presentan acusados aumentos de la anchura energetica a la temperatura de transicion. Estos efectos no se han podido explicar aun de manera logica. (author) [Russian] Nabljudenija za obychnymi formami kolebanija uporjadochennogo splava medi i cinka ({beta}-latun') pri 296 Degree-Sign K provodilis' s pomoshh'ju kogerentnogo odno fononnogo rassejanija medlennyh nejtronov na monokristallicheskih obrazcah. Dlja izmerenija chastot kolebanij, rasprostranjajushhihsja vdol' vysokosimmetrichnyh napravlenij [00{zeta}], [{zeta}{zeta}0], [{zeta}{zeta}{zeta}{zeta}] i [ Vulgar-Fraction-One-Half Vulgar-Fraction-One-Half {zeta}] ispol'zovalsja trehosnyj kristallicheskij spektrometr na reaktore NRU. Krivye dispersii napominajut krivye dispersii prostogo ob{sup e}mno-centrirovannogo kubicheskogo kristalla, naprimer Na, za iskljucheniem togo, chto pojavljajutsja nekotorye vyrozhdenija, v osnovnom vvidu razlichija mezhdu vtorym blizhajshim sosedom Si-Si i silami Zn-Zn. Naprimer, my nahodim dve razlichnye formy volnovogo vektora (0.5, 0.5, 0.5) (v obratnyh edinicah reshetki), chastoty kotoryh sootvetstvenno sostavljajut (4,21 {+-}0,06) i (4,93 10) * 10{sup 12} gerc. Kratko upominajutsja modeli mezhatomnyh sil, kotorye predstavljajut udovletvoritel'noe opisanie rezul'tatov, poluchennyh pri 296 Degree-Sign K. Nekotorye normal'nye formy kolebanij izucheny pri povyshennyh temperaturah, osobenno v oblasti perehoda iz uporjadochennogo sostojanija v neuporjadochennoe pri temperature priblizitel'no 727 Degree-Sign K. V obshhej strukture krivyh dispersij ne otmechaetsja znachitel'nyh izmenenij v rezul'tate ischeznovenija porjadka dal'nego rasstojanija pri jetoj temperature, hotja razlichnye ''rasshheplenija'', nabljudaemye pri 296 Degree-Sign K, rasplyvajutsja v bolee ili menee postojannye ''polosy'' chastot. Pri povyshenii temperatury chastoty v celom umen'shajutsja, a jenergeticheskie shiriny uvelichivajutsja. Jeti izmenenija proishodjat plavno, za iskljucheniem dvuh prodol

  5. Saddle-Point Rotational States from Resonance Fission of Oriented Nuclei; Etats Rotationnels a l'Etranglement Resultant de la Fission, par Neutrons de Resonance, de Noyaux Orientes; 0412 0420 0410 0429 0410 0422 0415 041b 042c 041d 042b 0415 0421 041e 0421 0422 041e 042f 041d 0418 042f 0421 0415 0414 041b 041e 0412 041e 0419 0422 041e 0427 K 0418 0412 0420 0415 0417 0423 041b 042c 0422 0410 0422 0415 0420 0415 0417 041e 041d 0410 041d 0421 041d 041e 0413 041e 0414 0415 041b 0415 041d 0418 042f 041e 0420 0418 0415 041d 0422 0418 0420 041e 0412 0410 041d 041d 042b 0425 042f 0414 0415 0420 ; Estados Rotacionales en el Punto de Estrangulacion Debidos a la Fision por Resonancia de Nucleos Orientados

    Energy Technology Data Exchange (ETDEWEB)

    Dabbs, J. W.T.; Walter, F. J.; Parker, G. W. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1965-07-15

    mucho mas preciso del numero y naturaleza de los canales de fision disponibles, cuestiones ambas que el fenomeno de la fision suscita desde hace mucho tiempo. En el {sup 235}U se observo, para las resonancias de 1,14 y 8,8 eV, una anisotropfa de los fragmentos de fision proxima al maximo posible, y de signo contrario al de la observada previamente en el caso de los heliones. Asimismo, se comprobo una marcada disminucion de la anisotropia para energias neutronicas proximas a la conocida resonancia de 0,3 eV. Como se carecia de informacion directa sobre los valores J del U se recurrio a un ajuste de niveles multiples a of, analogo al de Kirpichnikov y col., para el que se supuso que J(0,3 eV) Not-Equal-To J(1,14 eV), a diferencia de ajustes anteriores de caracter analogo. Estos datos iniciales son compatibles con una anisotropfa proporcional a la contribucion que se ha calculado aportan a of los dos valores posibles de J. Sin embargo, la forma de la curva no concuerda con otros datos tales como la variacion de la razon cresta a valle de Faler y Tromp; por consiguiente, no deben aceptarse aun como concluyentes los fuertes indicios de que J(0,3 eV) Not-Equal-To J(1,14 eV). Los autores estan efectuando mediciones complementarias para aclarar este concepto. (author) [Russian] Jadra aktinidnyh jelementov urana, neptunija i plutonija mozhno vystroit' v soedinenijah XO{sub 2}Rb(NO{sub 3}){sub 3} putem vzaimodejstvija kvadrupol'nogo momenta jadra s gradientom kristallicheskogo jelektricheskogo polja prosto v rezul'tate ohlazhdenija sootvetstvujushhego edinichnogo kristalla. Vystraivanie jader jetogo tipa sootvetstvuet neravnomernomu uglovomu raspredeleniju osi simmetrii sostavnogo jadra v prostranstve, chto otrazhaet v pervuju ochered' velichinu K. Esli predpolozhit', chto takovo zhe i raspredelenie oskolkov, to poluchim metod dlja ustanovlenija chisla kvantov K v sedlovoj tochke. V Okridzhe byli vypolneny jeksperimenty s vystroennymi jadrami urana-233 i urana{sup -}235 pri

  6. Neutron Investigation of Magnon Spectrum in Haematite; Etude du Spectre de Magnons dans l'Hematite, au Moyen des Neutrons; Nejtronnoe issledovanie spektra magnona v gematite; Estudio, por Metodos Neutronicos, del Espectro de Magnones en la Hematita

    Energy Technology Data Exchange (ETDEWEB)

    Dimitrijevic, Z.; Rzany, H.; Todorovic, J.; Wanic, A. [Institute for Nuclear Physics Cracow (Poland)

    1965-04-15

    -Sign y 126 Degree-Sign , respectivamente. Un acuerdo satisfactorio entre la teoria y los datos experimentales disponibles se tiene cuando SJ{sub 1} = SJ{sub 2} = 5,1 meV. Ademas de la rama magnonica acustica, los calculos han revelado la existencia de una rama optica, pero el estudio de esta no pudo llevarse a cabo por el metodo de difraccion neutronica. (author) [Russian] byli provedeny v Vincha na reaktore RA s ispol'zovaniem kristallicheskogo nejtronnogo spektrometra. Rassejanie monohromaticheskih nejtronov ({lambda} = 1.314A) proizvodilos' na krupnom monokristalle gematita ({alpha}-Fe{sub 2}O{sub 3}). Issledovalis' uglovye raspredelenija neuprugo rassejannyh nejtronov. Dlja rjada razlichnyh nepravil'nyh uglov kristalla AO byla izmerena shirina G puchka rassejannyh nejtronov (tak nazyvaemogo konusa rassejanija). Jetot konus rassejanija byl pripisan javleniju poverhnostnogo rassejanija magnona vokrug tochki obratnoj reshetki [1,1,1] . Dlja rjada skorostej magnona byla rasschitana i sravnena s jeksperimental'nymi tochkami zavisimost' G ot nepravil'nogo ugla. Ustanovleno, chto velichina skorosti v napravlenii [111] ravna 25,5 11,0 km/sek. Byla obnaruzhena strukturnaja anizotropija dispersionnogo sootnoshenija magnona. Bylo najdeno, chto skorost' javljaetsja bolee vysokoj v napravlenijah rasprostranenija parallel'nyh osi [111] i chto kachestvenno ona horosho soglasuetsja s bolee rannimi izmerenijami (Riste i dr.) dajushhimi v = 38km/sek. Obnaruzhit' v akusticheskoj oblasti jenergii magnona sushhestvovanie razryva jenergeticheskoj krivoj Eg ne udalos'. Bylo rasschitano, chto velichina E dolzhna byt' nizhe 1 Mjev. Pri pomoshhi formalizma Uollase byli rasschitany dispersionnye sootnoshenija magnona v gematite. Pri jetom ishodili ije predpolozhenija, chto sushhestvujut dva ne stremjashhihsja k nulju integrala obmena J{sub 1} i J{sub 2}. J{sub 1} i J{sub 2} oznachajut svjaz' sverhobmennoj jenergii mezhdu spinami sosednih ionov zheleza, svjazannyh ionom kisloroda. Ugly svjazi

  7. The Digital Autofluoroscope; L'Autofluoroscope Numerique; Tsifrovoj avtofluoroskop; Autofluoroscopio Numerico

    Energy Technology Data Exchange (ETDEWEB)

    Bender, M. A. [Roswell Park Memorial Institute, Buffalo, NY (United States)

    1964-10-15

    podhodjat k drugoj fototrubke. Impul'sy, voznikajushhie odnovremenno v ljuboj pare iz 35 fototrubok, v ravnoj mere dostigajut kristalla, v kotorom proishodit vzaimodejstvie. Pozicionnyj signal, voznikshij v fototrubke, ne zavisit ot vysoty impul'sa. Kontury antisovpadenija otvodjat odnovremennye impul'sy, voznikajushhie vrezul'tatev zaim od ej stvi ja Komptona, za kotorym sleduet absorbcija rassejannogo izluchenija v sosednem kristalle. Cifrovoj harakter si st emy svetovy h trubok horosho prisposoblen k hraneniju na magnitnom serdechnike s posledujushhim nepreryvnym schityvaniem bezrazrushenija pokazanij na polnorazmernoj katodno-luchevoj trubke ili k cifrovomu vypisyvaniju dlja kolichestvennogo analiza. Pervym preimushhestvom avtofluoroskopa nad radioizotopnymi skennerami javljaetsja znachitel'noe sokrashhenie vremeni, neobho dim o go dlja issledovanija. Pri ravnoj sistem e doz opuholi mozga i pecheni obnaruzhivajutsja v techenie 0,1 vremeni, neobhodimogo dlja obychnogo skennirovanija. Vtoroe preimushhestvo svjazano s t em , chto predostavljaetsja informacija obo vsem organe. Jeto daet vozmozhnost' prosledit' dinamicheskie processy vizual'no i ispol'zovat' izotopy ili mechenye soedinenija, imejushhie ochen' korotkie periody poluraspada i poluvyvedenija. S umen'sheniem perioda poluraspada mozh et byt' proi zv eden o sootv et s tv ujushh e e uvelichenie vvodimoj d ozy , rezul' tat om ch e go javljaetsja sokrashhenie vremeni obsledovanija. Vremja o b luchenija mozhet byt' takim korotkim, chto v nastojashhee vremja stali ispol'zovat' kinofoto- graficheskie metody dlja vizual'nogo nabljudenija i kolichestvennogo opredelenija prohozhdenija gippurana mechenogo, jodom-131, cherez pochki i bariem-137 cherez polosti serdca. (author)

  8. Ultrasonic Water-Gap Measurements in MTR Fuel Elements; Mesure par Ultrasons des Espaces Intercalaires dans les Elements Combustibles des Reacteurs d'Essai de Materiaux; Izmereniya vodyanogo zazora v teplovydelyayushchikh ehlementakh dlya materialovedcheskogo reaktora s pomoshch'yu ul'trazvuka; Medicion Ultrasonica de la Capa de Agua en Elementos Combustibles para Reactores de Ensayo de Materiales

    Energy Technology Data Exchange (ETDEWEB)

    Deknock, R. [Metallurgy Department, S.C.K./C.E.N., Mol (Belgium)

    1965-10-15

    en un convertidor tiempo-tension con circuitos logicos transistorizados. El instrumento permite un ajuste continuo del cero para cualquier espesor-arbitrario de la capa de agua entre 2 y 4 mm, con lo cual posibilita un registro con el cero en el centro de la escala. Ademas, cualquier intervalo deseado de 100 {mu}m puede dar una tension estable de 1 V a la salida para accionar un registrador. Se puede medir facilmente cualquier variacion en el espesor del agua con una precision de 5 {mu}m. Se han medido con este metodo varios elementos combustibles, y los resultados y la reproducibilidad fueron muy satisfactorios. (author) [Russian] Sil'nye potoki teplo- vyh nejtronov, kotorye obychno voznikajut v novejshih reaktorah dlja ispytanija materialov, javljajutsja podhodjashhim s r e d s t v om ravnomernoj teploperedachi i nadezhnogo otvoda tepla, s pomoshh'ju kotorogo mozhno izbezhat' obrazovanija para v bol'shih ob{sup e}mah. Krome togo, v celjah kontrolja nad obshhim raspuhaniem i povedeniem reaktornogo topli- va izmerjajut vodjanoj zazor pri jeksperimentah posle obluchenija s otrabotannymi teplovy- deljajushhimi jelementami. S jetoj cel'ju byl razrabotan zond dlja izmerenija 3 - m m vodjanogo zazora teplovydeljaju- shhego jelementa ispytatel'nogo reaktora BR-2 dlinoj bolee 1 m , v osnovu kotorogo polozhen princip ul'trazvuka. Pri jeksperimentah posle obluchenija izmeritel'nyj zond dolzhen dej- stvovat' v teplovydeljajushhem jelemente, pogruzhennom v bassejn na glubinu ne menee 6 m . Zond mozhet vyderzhat' pogruzhenie v vodu prodolzhitel'nyj period vremeni, i on ne podver- gaetsja vozdejstviju obychnyh doz gamma-obluchenija. Hotja sistema dejstvuet na osnove obychnogo metoda otrazhenija impul'sov, ona pozvo- ljaet razdeljat' ispuskaemye i otrazhennye impul'sy s pomoshh'ju 10 Mgc ferrojelektriches- kogo kristalla, kotoromu svojstvenno bol'shoe rassejanie jenergii. Mozhno ispol'zovat' zapis' pokazanij oscilloskopa, v kotorom vremja registriruetsja na gorizontal'noj osi

  9. Use of semiconductors in lieu of emulsions in nuclear spectroscopy; Utilisation de semi-conducteurs a la place d'emulsions en spectroscopie nucleaire; Primenenie poluprovodnikov vmesto ehmul'sij v yadernoj spektroskopii; Sustitucion de las emulsiones por semiconductores en espectroscopia nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Bilaniuk, O M; Marsh, B B [University of Rochester, Rochester, NY (United States)

    1962-04-15

    corrientes de salida excitan un convertidor de tiempo en amplitud de impulso 6BN6. El amplificador de parada contiene un retardo fijo de 2,5 {mu}s que garantiza que el impulso de parada siempre llegue al convertidor despues que el impulso de puesta en marcha. La amplitud del impulso que sale del convertidor 6BN6 es proporcional al intervalo de tiempo entre los impulsos de puesta en marcha y de parada, de modo que las senales que se producen en los diversos contadores del mosaico quedan identificadas por la amplitud del impulso que generan. Los grupos de cuentas resultantes se hacen visibles en la pantalla de un analizador de amplitudes de impulso de 400 canales, se imprimen, y se registran graficamente en un sistema de coordenadas ortogonales. Los grupos quedan enteramente resueltos, asi que la identificacion es completa. El circuito de identificacion es capaz de admitir un impulso cada 8 {mu}s, por lo que la limitacion de velocidad de contaje no se debe a el, sino al analizador de 400 canales. Los autores han encontrado que el sistema de identificacion funciona satisfactoriamente en presencia del campo magnetico y estando el ciclotron en plena marcha. Describen todos los circuitos del sistema de identificacion y presentan ejemplos de datos nucleares obtenidos con este dispositivo. (author) [Russian] Dvadtsat' poverkhnostno-bar'ernykh schetchikov, poluchennykh putem pokrytiya germaniya tipa ''n'' tonkim sloem zolota (nakhodyashchegosya v gazoobraznom sostoyanii), ili schetchiki s ploskostnym perekhodom, poluchaemye posredstvom diffuzii fosfora v kremnij tipa ,''p'', pomeshchayutsya v zerkal'nuyu ploskost' magnitnogo spektrometra s vysokoj razreshayushchej sposobnost'yu vmesto yadernoj ehmul'sionnoj plastiny. S tsel'yu izbezhat' primeneniya otdel'nykh usilitelej i registrov dlya kazhdogo kristalla vykhody otdel'nykh schetchikov soedinyayutsya v sosredotochennuyu liniyu zaderzhki, zamenyaya chereduyushchiesya kondensatory linij. Kogda ioniziruyushchaya chastitsa udaryaetsya o

  10. Renal Scintiscanning with Hg{sup 209}-Neohydrin in Urologic Diseases; Scintigraphy du Rein dans les Maladies des Voies Urin Aires au Moyen de Neohydrine Marquee avec {sup 203}Hg; Stsintillyatsionnoe skennirovanie pochek s pomoshch'yu neogidrina,mechennogo Rtut'yu-203, pri urologicheskikh zabolevaniyakh; Exploracion Centelleografica del Rinon con Neohydrina - {sup 203}hg en las Afecciones Urologicas

    Energy Technology Data Exchange (ETDEWEB)

    Bollini, V.; Tori, G. [Radiology Institute of the University of Bologna (Italy)

    1964-10-15

    determinar una disminucion de la funcion renal y a diferenciar los casos unilaterales de los bilaterales. Asi, la centelleografia del rinon constituye al parecer una tecnica clinica de gran utilidad, especialmente si se combina con el examen radiologico por medios tradicionales (urogtafia, pielografia ascendente, retroneumoperitoneo, tomografia, aorto- grafia, etc.). (author) [Russian] Dlja scintilljacionnogo skenirovanija pochek ispol'zovalsja neogidrin, mechennyj rtut'ju-203. Byl primenen jaderncj Chikagskij izotopnyj skenner tipa 1700 s kristallom 5 h 5 sm i kollimator ''Hanikoum'' s fokusnym rasstojaniem 7 sm. Obychno scintigrammy registrirujutsja odnovremenno na bumage i na fotoplenke. Neogidrin, mechennyj rtut'ju-203, primenjaetsja obychno v dozah 120 - 160 mkkjuri (okolo 2 mkkjuri/kg). Skennirovanie nachinajut spustja 2 chasa posle in{sup e}kcii i prodolzhajut 40 - 50 minut. Selektivnoe skoplenie mechenogo neogidrina v korkovom sloe pochek daet vozmozhnost' poluchit' graficheskoe izobrazhenie obeih pochek i opredelit' ih polozhenie, orientaciju i formu, a takzhe gomogennost' aktivno funkcionirujushhej parenhimy. V nekotoryh sluchajah byli provedeny avtoradiograficheskie issledovanija porazhennyh pochek posle hirurgicheskogo udalenija. S pomoshh'ju takogo metoda mozhno diagnoscirovat' kak vrozhdennye, tak i priobretennye anomalii polozhenija i orientacii. Chto kasaetsja formy, to granicy pochek mozhno opredelit' tem tochnee, chem luchshe funkcioniruet pochka. Takie tehnicheskie aspekty, kak shirina kristalla, tip kollimatora (fokal'naja ploskost' kotorogo dolzhna prohodit' cherez srednjuju poperechnuju ploskost' pochek) i doza, kotoraja ne dolzhna byt' slishkom vysokoj ili slishkom maloj, sostavljajut sushhestvennoe uslovie dlja pravil'nogo graficheskogo vosproizvedenija ochertanij pochek. Narushenie dejatel'nosti kanal'cev v parenhime opredeljaetsja blagodarja narusheniju pogloshhenija radioaktivnosti. Polozhenie, razmery i forma takih defektov pogloshhenija

  11. MASURCA, a Fast-Neutron Critical Mock-Up: Operation and Uses; MASURCA. Maquette Critique a Neutrons Rapides. Description Fonctionnelle et Obiectifs; ''MAZURKA'' - kriticheskaya model' na bystrykh nejtronakh. funktsional'noe opisanie i tseli; Descripcion Funcional y Objetivos de la Maqueta Critica de Neutrones Rapidos 'MASURCA '

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, A. P.; Storrer, F.; Vendryes, G. [Association CEA-EURATOM, Cadarache (France); Tavernier, G.; Van Dievoet, J. [Societe Belgo-Nucleaire, Bruxelles (Belgium)

    1964-02-15

    . (author) [Russian] V nastojashhee vremja v Centre jadernyh issledovanij Kadarash v ramkah Associacii Evratom -KAJe konstruiruetsja kriticheskij maket na bystryh nejtro- nah pod nazvaniem {sup M}azurka{sup .} Jeta ustanovka obladaet bol'shimi vozmozhnostjami dlja pro- vedenija jeksperimentov i prednaznachena glavnym obrazom dlja provedenija issledovanij na krupnyh plutonievyh kriticheskih sborkah bez zamedlitelej s otnositel'no podvizhnym nej- tronnym spektrom. Izlagajutsja celi issledovanij, dlja osushhestvlenija kotoryh podobnaja ustanovka dolzhna otvechat' opredelennym uslovijam. Prezhde vsego ona dolzhna imet' bol'shuju gibkost' v ispol'zovanii i obespechivat' pochti absoljutnuju bezopasnost' v rabote. Problema bezopasnosti byla reshena putem: 1 .Issledovanija prisushhej ustanovke bezopasnosti; jelementy, imitirujushhie toplivo, pozvolili poluchit': a) kojefficient otricatel'noj reaktivnosti v rezul'tate kumu- ljativnogo prodol'nogo rasshirenija jetih jelementov; b) otricatel'nyj kojefficient Dopplera. 2 .Ispol'zovanija puchka avarijnyh upravljajushhih sterzhnej i kompensirujushhih sterzhnej; jeti sterzhni mogut razmeshhat'sja na reshetke s kvadratom 30 sm. 3.Primenenija germeticheskoj kamery s argonom na sluchaj pozhara. 4 . Strogogo administrativnogo kontrolja. Vybor metallicheskogo splava uran -plutonij -zhelezo v kachestve osnovnogo jelementa imitirovanija topliva zastavljaet predusmatrivat' ohlazhdenie krupnyh kriticheskih sborok v ustanovke. Natrij v kachestve zhidkogo ohladitelja dlja modeliruemyh reaktorov predstavlen natrie- vymi palochkami v obolochke iz nerzhavejushhej stali. Jeta ustanovka predstavljaet soboj vertikal'no-monoblokovyj tip. Takoj vybor ob{sup -} jasnjaetsja stremleniem poluchit' maksimal'nyj ob{sup e}m aktivnyh zon, kotoryj bylo predusmot- reno modelirovat' (porjadka 5000 l). Imitirujushhie jelementy imejut formu prjamoj prizmy s kvadratnym osnovaniem (krome toplivnyh jelementov s krugovoj osnovoj) s vneshnej storonoj (ili diametrom) 12,7 mm

  12. The use of oxygen-14 in the study of positron polarization in a Fermi-type transition; Emploi de l'oxygene-14 pour l'etude de la polarisation des positions dans une transition du type Fermi; Ispol'zovanie kisloroda-14 dlya issledovaniya polyarizatsii pozitronov v prevrashcheniyakh tipa Fermi; Empleo del oxigeno-14 en el estudio de la polarizacion de los positrones en una transicion de tipo Fermi

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, F H; Gerhart, J B; Hopkins, J C; Bichsel, H; Stroth, J [University of Washington, Seattle, WA (United States)

    1962-01-15

    , prokhodit cherez chetnoe sostoyanie, perekhodit k drugomu nulevomu spinu i prevrashchaetsya v N{sup 14} v vozbuzhdennom chetnom sostoyanii. Poehtomu raspad proiskhodit tochno po tipu Fermi. Kislorod O{sup 14} byl poluchen reaktsiej N{sup 14} (p, n) O{sup 14} v 60-dyujmovom tsiklotrone Vashingtonskogo universiteta s postoyannym potokom azota N{sub 2}. K N{sub 2} byl dobavlen nositel' O{sub 2} v gazoobraznom vide. Posle aktivizatsii gaz propuskalsya cherez sootvetstvuyushchie fil'try dlya udaleniya nezhelatel'noj aktivnosti i dlya obespecheniya soedineniya kisloroda s vodorodom. Aktivizirovannye vodyanye pary zakhvatyvalis' pri temperature zhidkogo azota N{sub 2} i ulavlivalis' na mednuyu palochku dlya obrazovaniya sil'nogo (okolo 10 millikyuri) postoyannogo istochnika 72-sekundnogo kisloroda O14. Obrazuyushchiesya pri raspade pozitrony analizirovalis' s tochki zreniya ikh ehnergii v nebol'shom magnitnom spektrometre. Dva metoda byli ispol'zovany dlya izucheniya prodol'noj polyarizatsii vykhodyashchikh iz spektrometra pozitronov. V pervom iz nikh pozitrony popadali v plasticheskij stsintillyator, gde nekotorye iz nikh unichtozhalis' na letu. Annigiliruyushchijsya kvant bolee vysokikh ehnergij polyariziruetsya vrashchatel'no v tom zhe samom napravlenii, chto i pervonachal'nye pozitrony. EHti gamma-luchi rasseivalis' iz namagnichennogo zheleza po Komptonu i podschityvalis' pri pomoshchi stsintillyatsionnogo schetchika s Nal(T). Assimetrichnost' poperechnogo secheniya rasseivaniya v zavisimosti ot napravleniya namagnichivaniya svyazana s pervonachal'noj stepen'yu polyarizatsii pozitronov. Vo vtorom metode pozitrony sosredotochenno napravlyalis' na namagnichennuyu zheleznuyu fol'gu. Poperechnoe sechenie rasseivaniya pozitronov-ehlektronov ili rasseivaniya Baba zavisit ot napravleniya namagnichivaniya zheleznoj fol'gi po otnosheniyu k polyarizatsii pozitronov. Rasseyannye ehlektrony i pozitrony obnaruzhivalis' pri pomoshchi plasticheskikh stsintillyatsionnykh schetchikov

  13. Theoretical and Applied Aspects of Radiation D-Values for Spores of Clostridium Botulinum; Aspects Theoriques et Pratiques des Valeurs D de Rayonnement Appliquees aux Spores de Clostridium Botulinum; Teoreticheskie i prikladnye aspekty koehffitsienta izlucheniya odlya spor Clostridium Botulinum; Aspectos Teoricos y Practicos de los Valores D para Esporas del Clostridium Botulinum

    Energy Technology Data Exchange (ETDEWEB)

    Grecz, N. [Biophysics Laboratory, Illinois Institute Of Technology, Chicago, IL (United States)

    1966-11-15

    pishhevyh produktov. Obshirnye dannye, imejushhiesja v laboratorii, pokazali, chto: 1) znachenie kojefficienta D{sub 10} opredelennogo vida zavisit ot temperatury, sredy i razmera spor i 2) sushhestvenno razlichnye znachenija kojefficienta D mogut byt' polucheny v zavisimosti ot metoda rascheta i neizvestnyh variacij v razlichnyh jeksperimentah. Jeta informacija obespechivaet osnovu dlja pereocenki koncepcii 12 x D. Pokazano, chto temperatura'vo vremja obluchenija mozhet vozdejstvovat' na kosvennye vlijanija radikalov: 1) na obrazovanie, 2) na himicheskuju reaktivnost', 3) na stepen' razrushenija i 4) na diffuziju, osobenno vo vremja perehoda sredy iz zhidkogo sostojanija v tverdoe pri temperature primerno 0 Degree-Sign S. Kombinacija jetih vlijanij v zavisimosti ot temperatury ob'jasnjaet, pochemu spory naibolee chuvstvitel'ny, kogda oni obluchajutsja pri temperature 0 Degree-Sign S, po sravneniju s bolee vysokimi ili nizkimi temperaturami. Krome ee vlijanija na radikaly, temperatura takzhe vlijaet neposredstvenno na osnovnye, misheni (DNK). Jeto zatragivaet vibracionnoe sostojanie, a takzhe i stepen' gidratacii molekul DNK. Ochevidnaja gidratacija DNK svja zana s diapazonom dejstvija kosvennyh vlijanij, kotoryj mozhet byt' vychislen dlja C.botulinum 33 A, chtoby dobavit' 30 A k radiusu DNK (10,5 A), t.e. pochti v tri raza bol'she vlijanija obluchenija. Jeto izmenenie v radiochuvstvitel'nom ob'eme otrazhaetsja sootvetstvujushhim izmeneniem v znachenii D{sub 37} ot 1,6 x 10{sup 5} rad dlja suhoj spory do 6,6 x 10{sup 4} rad dlja vlazhnoj spory. Suspenzirujushhaja sreda mozhet byt' libo okonchatel'noj dlja radikalov, tak, naprimer, bol'shinstvo produktov i mikrobiologicheskih sred javljajutsja raskisliteljami radikalov, libo ona mozhet sposobstvovat' obrazovaniju vrednyh radikalov, tak naprimer, fosfatnyj buffer obrazuet fosfatnuju kislotu, kislorod obrazuet perekisnye i pergidridnye radikaly. Izmenenie znachenij D{sub 10} otdel'nogo vida, vyzvannye razlichnymi

  14. Theoretical and Experimental Aspects of Quenching Variables from Biomedical Samples in Liquid Scintillator Systems; Aspects Theoriques et Experimentaux des Parametres d'Extinction Etudies sur des Echantillons Biomedicaux dans des Systemes a Scintillateur Liquide; Teoreticheskie i ehksperimental'nye aspekty peremennykh gasheniya iz biomeditsinskikh prob v zhidkikh stsintillyatsionnykh sistemakh; Estudio Teorico y Experimental de las Variables de Extincion en el Recuento de Sustancias Biological por Centelleo Liquido

    Energy Technology Data Exchange (ETDEWEB)

    Ross, H. H. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1965-10-15

    popravki na gashenie dajut vozmozhnost' opredeljat' obshhuju velichinu gashenija v dannoj probe, ne predstavljaetsja vozmozhnym opredeljat' absoljutnuju dolju uchastija v gashenii okraski i fluorescencii. Jeti svedenija predstavljajut bol'shoe znachenie dlja konstrukcii novyh i bolee jeffektivnyh scintilljacionnyh sistem, a takzhe dlja kriticheskoj ocenki bolee staryh sistem s cel'ju vnesenija vozmozhnyh uluchshenij. Nedavno avtoru doklada udalos' vyrabotat' dva nezavisimyh metoda dlja opredelenija, otdel'nyh vyzyvajushhih gashenie peremennyh v zhidkih sistemah. Pervyj metod pokazyvaet, chto na osnovanii spektrofotometricheskih dannyh predstavljaetsja vozmozhnym ispol'zovat' obshhuju matematicheskuju model' dlja tochnogo predskazanija stepeni obescvechivanija v ljuboj probe. Jetot podhod analogichen metodu opredelenija obshhego pogloshhenija sveta v mnogokomponentnoj sisteme, i on privodit v konechnom schete k integral'nomu uravneniju tipa: Q = {integral}{sup {lambda}{sub n{sub {lambda}{sub {sub l}}}}} (K)(A)d{lambda}, kotoroe dlja prakticheskih nadobnostej mozhno legko uprostit'. Jetot metod mozhet davat' tochnye svedenija dlja ocenki kombinirovannogo vozdejstvija gashenija okraski i fluorescencii i vmeste s tem sposobstvovat' luchshemu ponimaniju faktorov, vyzyvajushhih obescvechivanie. Odnako pri neobhodimosti analizirovat' povsednevno bol'shoe kolichestvo prob jeksperimental'naja procedura stanovitsja dovol'no trudoemkoj. Vtoroj metod - novyj jeksperimental'nyj metod vnesenija popravki na gashenie okraski putem ispol'zovanija {sup i}zolirovannogo vnutrennego standarta{sup .} Primenjaja jetot metod s ljubymi drugimi metodami opredelenija obshhej popravki na gashenie, mozhno legko otdelit' vozdejstvie gashenija okraski ot himicheskogo gashenija. Metod izolirovannogo vnutrennego standarta osnovan na pogloshhenii svetovyh fotonov v probe zhidkogo scintilljatora s gashenoj okraskoj. Odnako v protivopolozhnost' opisannomu vyshe spektrofotometricheskomu metodu istochnik sveta

  15. Determination of Fallout Radionuclides in Environmental Samples by Gamma-Ray Spectrometry; Mesure Spectrometrique Gamma des Radionucleides de Retombee Presents dans des Echantillons du Millieu; Opredelenie radioizotopov radioaktivnykh osadkov v probakh iz okruzhayushchej sredy pri pomoshchi spektrometrii gamma-luchej; Determinacion, por Espectrometria Gamma, de los Radionuclidos de Precipitaciones en Muestras del Medio Ambiente

    Energy Technology Data Exchange (ETDEWEB)

    Ward, G. M.; Johnson, J. E.; Wilson, D. W. [Department of Animal Science, Colorado State University, Fort Collins, CO (United States)

    1965-10-15

    vremeni na universitetskoj ferme sobrali znachitel'noe kolichestvo prob iz okruzhajushhej sredy dlja izuchenija dvizhenija cezija-137 v znachitel'noj chasti pishhevoj ce- pochki cheloveka. Vse proby imeli maluju udel'nuju aktivnost', i izmerenija proizvodili pri pomoshhi spektrometricheskogo ustrojstva dlja gamma-luchej nizkogo urovnja, sostojashhego iz kristalla NaJ (T1) diametrom 8 i tolshhinoj 4 djujma, prichem jetot kristall byl zashhishhen ot fona stal'noj kameroj s tolshhinoj stenok 5 djujmov i soedinen s 400-kanal'nym anali- zatorom amplitudy impul'sov. Otschet nabivok vozdushnyh fil'trov i krupnyh prob ( 1kg) suhogo furazha, zerna i pometa krupnogo rogatog o skota proizvodili neposredstvenno v postojannoj geometrii. Proby osadkov koncentrirovali propuskaniem ih cherez kationo- obmennye kolonki, zapolnennye doveksom-50. Radioaktivnost' moloka, mjasa i mochi pod- schityvali v bol'shih kol'ceobraznyh kontejnerah iz ljucita. V moloke, mjase i moche ob- naruzhivajutsja v chisle gamma-izluchajushhih radioizotopov lish' cezij-137, kalij-40, jod-131, barij-140 i lantan-140, poskol'ku oni javljajutsja edinstvennymi produktami delenija, po- gloshhaemymi v znachitel'nyh kolichestvah. Pomimo jetogo, drugie proby soderzhali cezij-141, cezij-144, sur'mu-125, rutenij-103, rutenij-106, cirkonij-95, niobij-95 i marganec-54. V probah, sobrannyh v 1962 i 1963 godah, pri pomoshhi'gamma-spektrometrii udalos' oprede- lenno obnaruzhit' lish' cirk{sup n}ij-95 i niobij-95 vvidu ih otnositel'nogo obilija; jeto bylo prodelano priblizitel'no za 6 mesjacev posle sbora prob. Fotopiki cezija-137, marganca-54 i sur'my-125 byli sovershenno rasplyvchatymi, a radioizotopy bolee malyh jenergij (cezij-141, cezij-144 i rutenij-103) imeli znachitel'nye komptonovskie vklady ot radio- izotopov bolee vysokih jenergij. Pri nedostatochno jasnyh fotopikah posledovatel'noe vydelenie produktov delenija iz spektrov ne javljaetsja nadezhnym. Kogda vlijanie drugih radioizotopov delaet nevozmozhnym