Capteur de CO{2} à fibres optiques par absorption moléculaire à 4,3 μm
NASA Astrophysics Data System (ADS)
Bendamardji, S.; Alayli, Y.; Huard, S.
1996-04-01
This paper describes a remote optical fibre sensor for the carbon dioxide detection by molecular absorption in the near infrared (4.3 μm) corresponding to fundamental mode ν3. To overcome the problem of the strong attenuation signal of optical fibre in the near infrared, we have used the opto-suppling technique which changes the working wavelength from 4.3 μm to 860 nm and permits the use of standard optical fibre 50/125. The simulation of absorption has been obtained by original modelisation of the absorption spectrum and the establishment of the calibration curves takes to the sensor to detect a partial pressures greater than 100 μbar with a minimal error margin of 100 μbar, which is acceptable considering the future use of the device. The sensor has been designed to monitor the CO{2} rate in enriched greenhouses. Cet article décrit un capteur à fibres optiques de gaz carbonique par absorption moléculaire dans l'infrarouge moyen (4,3 μm) correspondant au mode fondamental ν3. La liaison entre le site de mesure et le site de contrôle est assurée par un fibre optique standard 50/125 après une transposition de longueur d'onde de 4,3 μm à 860 nm par opto-alimentation. La simulation de l'absorption a été obtenue par modélisation originale du spectre d'absorption et l'établissement des courbes d'étalonnage prévoit une marge d'erreur minimale de 100 μbar, ce qui est suffisant pour l'application du dispositif à la régulation de taux CO{2} dans les serres agricoles enrichies par de gaz.
NASA Astrophysics Data System (ADS)
Pigeon, F.; Mure-Ravaud, A.; Veillas, C.; Gagnaire, H.
1991-07-01
A theoretical and experimental study of the polarization properties change induced by a mechanical deformation of a standard single mode fiber is presented. These results have been used to design a vibration sensor by coiling a standard single mode fiber. Conditions for linear response and good sensitivity are discussed. Nous présentons une étude théorique et expérimentale des modifications de polarisation induites dans une fibre optique unimodale standard soumise à une perturbation mécanique. Ces résultats ont été utilisés pour réaliser un capteur de vibrations à l'aide d'une fibre optique bobinée. Nous discutons les conditions pour obtenir une réponse linéaire et une bonne sensibilité.
Capteurs à fibres optiques infrarouge dédiés à la détection in situ d'anomalies métaboliques
NASA Astrophysics Data System (ADS)
Keirsse, J.; Boussard-Pledel, C.; Bureau, B.; Sire, O.; Loreal, O.; Lucas, J.
2002-06-01
Le domaine du moyen infra-rouge contient l'essentiel des signatures spectrales des molécules biologiques. Le développement d'une nouvelle génération de fibres optiques travaillant dans ce domaine spectral, nous a pertuis de concevoir une instrumentation dédiée à la détection tissulaire d'anomalies métaboliques. La richesse des informations recueillies couplée à la possibilité de réaliser des analyses in-situ permet d'envisager son utilisation dans les contextes très variés du domaine de la santé. Nous cherchons à optimiser les performances du capteur IR en utilisant deux modèles distincts : le développement et la caractérisation d'un biofilm bactérien d'une part, les anomalies métaboliques associées aux pathologies hépatiques, d'autre part.
Sensibilité à la température d'un capteur de pression partielle de gaz carbonique à fibres optiques
NASA Astrophysics Data System (ADS)
Bendamardji, S.; Alayli, Y.
1998-03-01
An optical fibre sensor to measure weak partial pressures of carbon dioxide has been designed and realized. This sensor is based on direct molecular absorption in the near infrared at 4.3 μ{m}. It is an extrinsic and amplitude modulation type sensor. In the linear region between 0 and 2000μbar, the calibration curve that represents the transmitted power versus the carbon dioxide partial pressure in air shows a sensitivity of 20 nW/mbar with a minimum detectable pressure of 25 μbar. This article describes a temperature sensitivity analysis for all optoelectronic components and proposes a calculation method to distinguish two successive levels of partial pressure in a surrounding atmosphere where the temperature can vary. The experimental results show that without using a reference signal, the maximum variation of temperature is ± 1.4^circC. The use of a reference signal combined with thermoelectric cooling of the photodetector tolerates a temperature variation of ± 25^circC. Un capteur à fibres optiques permettant la mesure de faibles pressions partielles de gaz carbonique a été conçu et réalisé. Ce capteur basé sur l'absorption moléculaire directe dans l'infrarouge à 4,3μ m est de type extrinsèque à modulation d'amplitude. Dans la région linéaire entre 0 et 2000 μbar, la courbe d'étalonnage représentant la puissance transmise en fonction de la pression partielle de CO_2 dans l'air montre une sensibilité de 20 nW/mbar avec une pression minimale de détection de 25 μbar. Cet article concerne une analyse de sensibilité à la température de l'ensemble des constituants optoélectroniques du capteur en proposant une méthode de calcul qui permette de discerner deux niveaux successifs de pression partielle dans un environnement assujetti à une variation de la température. Les résultats expérimentaux montrent que, sans utilisation d'un signal de référence, la variation maximale de température admise est de ± 1,4^circC alors que l
Sensibilité à la température d'un capteur de pression partielle de gaz carbonique à fibres optiques
NASA Astrophysics Data System (ADS)
Alayli, Y.; Bendamardji, S.
1998-03-01
An optical fibre sensor to measure weak partial pressures of carbon dioxide has been designed and realized. This sensor is based on direct molecular absorption in the near infrared at 4.3 μ{m}. It is an extrinsic and amplitude modulation type sensor. In the linear region between 0 and 2000μbar, the calibration curve that represents the transmitted power versus the carbon dioxide partial pressure in air shows a sensitivity of 20 nW/mbar with a minimum detectable pressure of 25 μbar. This article describes a temperature sensitivity analysis for all optoelectronic components and proposes a calculation method to distinguish two successive levels of partial pressure in a surrounding atmosphere where the temperature can vary. The experimental results show that without using a reference signal, the maximum variation of temperature is ± 1.4^circC. The use of a reference signal combined with thermoelectric cooling of the photodetector tolerates a temperature variation of ± 25^circC. Un capteur à fibres optiques permettant la mesure de faibles pressions partielles de gaz carbonique a été conçu et réalisé. Ce capteur basé sur l'absorption moléculaire directe dans l'infrarouge à 4,3;μ m est de type extrinsèque à modulation d'amplitude. Dans la région linéaire entre 0 et 2000 μbar, la courbe d'étalonnage représentant la puissance transmise en fonction de la pression partielle de CO_2 dans l'air montre une sensibilité de 20 nW/mbar avec une pression minimale de détection de 25 μbar. Cet article concerne une analyse de sensibilité à la température de l'ensemble des constituants optoélectroniques du capteur en proposant une méthode de calcul qui permette de discerner deux niveaux successifs de pression partielle dans un environnement assujetti à une variation de la température. Les résultats expérimentaux montrent que, sans utilisation d'un signal de référence, la variation maximale de température admise est de ± 1,4^circC alors que l
NASA Astrophysics Data System (ADS)
Pellat-Finet, Pierre
L'optique de Fourier doit son nom à l'emploi délibéré de la transformation de Fourier dans la représentation de phénomènes fondés sur la diffraction de la lumière1. Inscrite dans les limites d'une théorie scalaire, elle est, traditionnellement, liée à l'optique cohérente et les sujets développés dans ce livre se rattachent à ce thème. Le domaine et les applications ussuelles de l'optique de Fourier concernent la formation des images, la résolution des instruments d'optique, le traitement du signal optique, l'holographie, le transfert de la cohérence. Nous verrons comment y inclure la théorie des résonateurs optiques et celle des faisseaux gaussiens; celle de la dispersion dans les fibres optiques. L'optique de Fourier fournit ainsi un cadre général à la modélisation d'un grand nombre de phénomènes optiques2.
Alignement automatise de fibres optiques amorces monomodes
NASA Astrophysics Data System (ADS)
St-Amant, Yves
Cette these jette les bases necessaires au developpement d'algorithmes a base de modele pour l'automatisation de l'alignement de fibres amorces monomodes. A partir de la methode de l'integrale de recouvrement et de deux solutions approximatives existantes, un modele analytique d'efficacite de couplage optique permettant d'estimer la puissance transmise entre un composant et une fibre amorce monomode est d'abord formule. Avec celui-ci, sept proprietes pouvant etre utiles au developpement d'algorithmes a base de modele sont ensuite identifiees et validees. Enfin, a l'aide de ces proprietes, une strategie d'alignement a base de modele est developpee et validee experimentalement. Les resultats obtenus demontrent clairement la repetitivite, la robustesse, la precision et la rapidite de la strategie proposee. Ils demontrent aussi qu'il est possible de realiser un alignement complet sans l'utilisation de systemes auxiliaires tels des systemes de vision, des cameras infrarouges, des capteurs de contact ou des systemes de fixation hautement precis.
Capteur de temperature interferometrique a fibre optique monomode
NASA Astrophysics Data System (ADS)
Lacroix, S.; Bures, J.; Parent, M.; Lapierre, J.
1984-08-01
We describe the use of an optical fiber reflection two-wave interferometer as a temperature sensor. As it uses only one fiber this device is easy to set up. We calculate its sensitivity based on the temperature rate of change of the refractive index and length of the fiber, for the case of pure silica. The measured sensitivity, equal to 73 fringes/°C for a 1 m long fiber, is slightly higher than the theoretical value. This result is in agreement with the expected increase in the thermal expansion and thermo-optic coefficients of doped silica.
Astronomie et optique : un couple heureux
NASA Astrophysics Data System (ADS)
Léna, Pierre
2004-11-01
Les développements de l'optique ont accompagné le flot de découvertes qui caractérise le développement de l'astronomie depuis trois ou quatre décennies. Les instruments en cours ou en projet s'attaquent tout particulièrement à la résolution angulaire, avec des applications majeures concernant l'observation des trous noirs massifs au centre des galaxies, dont la nôtre, et des planètes extrasolaires. Ces aspects sont brièvement évoqués ici, à propos de l'optique adaptative et de l'interférométrie optique.
NASA Astrophysics Data System (ADS)
Bergeron, Alain
Cette recherche vise a la mise en oeuvre optique de reseaux neuronaux. Deux architectures differentes sont proposees. La premiere est la memoire associative permettant d'associer a un objet quelconque une sortie arbitraire tout en preservant l'information sur sa position. La seconde architecture, le classificateur neuronal pour le controle robotique, permet l'identification d'une entree et son classement selon differentes categories. La sortie est compatible avec les systemes numeriques standard. Pour realiser ces architectures, une approche modulaire est privilegiee. Le correlateur constitue le module de base des realisations. Differents modules sont de plus introduits pour realiser convenablement les operations neuronales. Le premier de ces modules est le seuil optoelectronique permettant de realiser une fonction non lineaire, element essentiel des reseaux neuronaux. Le second module a etre introduit est l'encodeur optonumerique, utile au classement des objets. Le probleme de l'enregistrement de la memoire est aborde a l'aide du codage iteratif global.
Les Reseaux de Bragg dans la Fibre Optique et leurs Applications
NASA Astrophysics Data System (ADS)
Lauzon, Jocelyn
Dans les systemes de communications optiques actuels, la fibre optique ne constitue qu'un canal de transmission. L'amplification des signaux transmis ainsi que les decisions les concernant, comme la commutation, se font electroniquement. La conversion des signaux optiques en signaux electroniques (et vice versa) est couteuse et d'efficacite restreinte. Il est donc necessaire pour les chercheurs de trouver des strategies qui permettraient de transmettre le signal d'un bout a l'autre de la ligne sous forme optique. Deja, des amplificateurs a fibre existent pour repondre au premier probleme; il reste a trouver une maniere tout-optique de prendre des decisions par rapport au signal transmis. L'utilisation de filtres passifs, hautement selectifs en longueur d'onde et inscrits directement dans la fibre optique, est une solution elegante pour repondre a ce second probleme. Les reseaux de Bragg dans la fibre optique correspondent a cette description: nous avons donc decide de les etudier de facon rigoureuse. Nous avons d'abord tente de mieux comprendre la reaction photosensible provoquant l'inscription de ce genre de dispositif dans certaines fibres optiques. Ensuite, une nouvelle methode d'inscription de reseaux de Bragg dans la fibre optique a ete elaboree et caracterisee. Finalement, certaines applications des reseaux que nous avons inscrits ont ete proposees. L'etude de la reaction photosensible a ete faite indirectement, a l'aide de phenomenes provoques par celle -ci: la photoluminescence, l'attenuation photo-induite et les changements d'indice photo-induits. L'observation de ces phenomenes nous a permis de developper un modele sommaire, expliquant en partie la reaction photosensible. Le montage d'ecriture des reseaux de Bragg dans la fibre optique nous a permis d'observer la nature quasi -isotrope du changement d'indice photo-induit. La qualite des reseaux de Bragg inscrits a l'aide de ce montage a ete evaluee. Le montage nous a aussi permis de demontrer que la
NASA Astrophysics Data System (ADS)
Gautier, J.; Delmotte, F.; Bridou, F.; Rouillay, M.; Varniere, F.; de Rossi, S.; Jerome, A.
2006-12-01
L'élaboration de nouveaux revêtements interférentiels multicouches est motivée par la demande de l'astrophysique solaire et par le développement de nouvelles sources de rayonnement EUV (source à génération d'harmoniques d'ordre élevé, laser X, rayonnement synchrotron). Nous avons étudié et développé différents systèmes multicouches possédant à la fois des propriétés optiques optimisées (réflectivité et/ou bande passante) et une bonne stabilité temporelle et thermique pour la gamme de longueurs d'onde comprise entre λ = 30 nm et λ = 50 nm. Une augmentation significative de la réflectivité des multicouches dans la gamme spectrale de 30 à 40 nm a été obtenue par l'addition d'un troisième matériau dans l'empilement. Une étude comparative des courbes de réflectivités théorique et expérimentale en fonction de la longueur d'onde a été menée. Les différences observées ont pu être expliquées notamment à l'aide de l'analyse des propriétés physiques des différents matériaux en couche mince. Nous montrons également que l'utilisation de ces multicouches à trois matériaux par période permet le développement d'empilements répondant à des demandes spécifiques (miroirs à large bande passante, miroirs à double bande). Pour les longueurs d'ondes comprises entre 35 nm et 50 nm nous avons développé des multicouches à base de scandium. Cette étude a permis d'obtenir des multicouches avec de forts pouvoirs réflecteurs et une bonne stabilité temporelle. La stabilité de ces empilements a pu être améliorée à l'aide de l'insertion aux interfaces de couches barrières.
Bistabilité optique dans un laser à absorbant saturable trimode
NASA Astrophysics Data System (ADS)
Djabi, S.; Djabi, M.; Benkherourou, O.
2005-10-01
Cettte étude est consacrée à l'élaboration d'un modéele mathématique simple pour décrire l'action des lasers à absorbants saturables, l'approche envisage ici tient compte d'une manière phénoménologique des processus physiques essentiels qui permet de dégager les principaux paramètres physiques dans les LSA et leurs influences sur la bistabilité optique. Nous allons étudier théoriquement la bistabilité optique dans les lasers à absorbants saturables trimodes dans le cas où les deux milieux actif et absorbant subissent un élargissement homogène. Nous avons établi un programme permettant de déterminer l'effet de la bistabilité optique, de tracer les courbes qui représentent les densités de photons en fonction du pompage du milieu actif et d'analyser la stabilité linéaire des solutions obtenues.
Amplification sans bruit d'images optiques
NASA Astrophysics Data System (ADS)
Gigan, S.; Delaubert, V.; Lopez, L.; Treps, N.; Maitre, A.; Fabre, C.
2004-11-01
Nous utilisons un Oscillateur Paramétrique Optique (OPO) pompé sous le seuil dans le but d'amplifier une image multimode transverse sans dégradation du rapport signal à bruit. Le dispositif expérimental met en œuvre un OPO de type II triplement résonant et semi-confocal pour le faisceau amplifié. L'existence d'effets quantiques lors de l'amplification multimode dans un tel dispositif a été montrée expérimentalement. Plus généralement, ceci nous a amené à étudier les propriétés quantiques transverses des faisceaux lumineux amplifiés. Une telle étude peut trouver des applications non seulement en imagerie, mais également dans le traitement quantique de l'information.
Capteurs à ondes élastiques guidées
NASA Astrophysics Data System (ADS)
Royer, D.; Dieulesaint, E.; Legras, O.
1992-01-01
The sensors described here have been studied in our laboratory. The industrial development of some of them is now in progress. They exploit the properties of elastic waves propagating, according to a chosen mode, in a plate or in a cylinder. The sensors comprising a plate are a graphic tablet, a map coordinate resolver, a touch screen and a liquid presence detector. The sensors comprising a cylinder are a liquid presence detector and a liquid level sensor. Before describing these devices, we comment on the dispersion curves and express the attenuation factor for guided waves in presence of a liquid. Les capteurs présentés dont certains sont en cours de développement industriel ont été étudiés dans notre laboratoire. Ils exploitent les propriétés d'ondes élastiques se propageant, suivant un mode choisi, dans une plaque ou un cylindre. Les capteurs comprenant une plaque sont une tablette de saisie de graphiques, un coordinomètre, un écran tactile et un détecteur de la présence d'un liquide, les capteurs comprenant un cylindre ou un tube sont un détecteur de présence et un jaugeur du niveau d'un liquide. Avant de les décrire, nous commentons les courbes de dispersion et calculons le coefficient d'atténuation de ces ondes guidées en présence d'un liquide.
Étude de la sensibilité d'un capteur de pression à quartz à distribution radiale
NASA Astrophysics Data System (ADS)
Delaite, R.
1996-03-01
An analysis is presented to determine the sensitivity of a piezoelectric pressure sensor in the case of a resonator subject to radial compression uniformly distributed over an angular part of the crystal edge. For a cut crystal singly rotated and for a doubly rotated, a coefficient of pressure sensitivity is calculated and gives the advantage of introducing the optimal value of the angular sector, as well as the azimut of application of the pressure. This solution becomes particularly interesting if one applies it to a singly rotated AT-cut crystal. Une étude est effectuée pour déterminer la sensibilité d'un capteur de pression à quartz dans le cas d'une distribution uniforme de la pression selon un secteur angulaire à la périphérie du cristal. Un coefficient de sensibilité à la pression est calculé pour des coupes à simple ou double rotation. Il permet d'introduire une valeur optimale du secteur angulaire et de sa position dans le repère du cristal. Cette solution devient intéressante pour le capteur si on utilise une coupe AT.
NASA Astrophysics Data System (ADS)
Lê, Minh-Quang; Placko, Dominique
1995-06-01
This paper describes a new structure for eddy-current transducers which improves sensitivity while maintaining high lateral resolution. We have developed an analytical model to allow a model-based inversion from transducers signals to estimate thick and homogeneous plates electrical conductivity, magnetic permeability and/or lift-off. The inversion procedure is described and shows the possibility of a precise simultaneous estimation of the three parameters. Experiments were conducted with magnetic and non magnetic metals. Cet article décrit une nouvelle structure de capteur à courants de Foucault qui permet d'améliorer la sensibilité du capteur tout en conservant sa résolution latérale. Nous avons développé un modèle analytique de ce capteur qui peut être inversé pour estimer la conductivité électrique, la perméabilité magnétique d'une cible homogène et/ou la distance capteur-cible. La procédure d'inversion a été décrite et montre une possibilité d'estimer ces trois paramètres avec précision. L'expérience a été effectuée sur des métaux magnétiques et amagnétiques.
Dérives thermiques du capteur de pression capacitif microélectronique
NASA Astrophysics Data System (ADS)
Ettouhami, A.; Essaid, A.; Ouakrim, N.; Michel, L.; Limouri, M.
1997-07-01
The thermal drifts of microelectronic capacitive pressure sensor have been analysed by finite-element method. Various boundary conditions representing a wide gamut of support of sensor have been considered: sensor with free base, sensor with fixed base and sensor attached to a support of alumina. For every case, the thermal response of sensor have been determined as a function of sensor dimensions in order to push far the buckling temperature and hence reduce the thermal sensitivity. For some sensors very sensitive to pressure, this temperature is small and the thermal drifts are important. A sensor with fixed base having a diaphragm of 1000 μm of radius and 12 μm of thickness and having a 3.5 μm of plate separation presents a thermal sensitivity of -200 Pa °C^{-1} above 80 ^circC. A sensor attached to a support of alumina, having a more wide diaphragm (1800 μm of radius) presents a thermal sensitivity of 3.1 Pa °C^{-1} below -100 ^circC. Les dérives thermiques du capteur de pression capacitif microélectronique sont analysées par la méthode des éléments finis. Différentes conditions aux limites représentant une large gamme de support de capteur ont été envisagées : capteur à base libre, capteur à base fixe et capteur collé à un support d'alumine. Dans chaque cas, la réponse thermique du capteur a été déterminée en fonction des dimensions du capteur afin de repousser la température de flambage et réduire en conséquence la sensibilité thermique. Pour certains capteurs très sensibles à la pression, cette température est très faible et les dérives thermiques sont importantes. Ainsi un capteur à base fixe (membrane de rayon 1000 μm, et épaisseur 12 μm, distance entre armatures 3,5 μm) présente une sensibilité thermique de -200 Pa °C^{-1} au-dessus de 80 ^circC. Un capteur collé à un support d'alumine, de membrane plus large (rayon 1800 μm) possède une sensibilité thermique de 3,1 Pa °C^{-1} au-dessous de -100 ^circC.
Amplification Raman stimulée de signaux hyperfréquences sur porteuse optique
NASA Astrophysics Data System (ADS)
Keïta, K.; Delaye, P.; Frey, R.; Roosen, G.; Dolfi, D.; Huignard, J.-P.
2006-10-01
À l'heure actuelle, lorsque l'on souhaite amplifier une porteuse optique, la solution consiste à utiliser un amplificateur à fibre dopée Erbium (EDFA). Toutefois, un problème se pose lorsque le signal modulant se trouve dans le domaine hyperfréquence car ces applications (principalement radars) demandent d'obéir à des critères de qualité très sévères. Nous démontrons ici la supériorité en termes de bruit de l'amplificateur Raman à fibre sur l'EDFA lorsqu'il s'agit d'amplifier de faibles signaux.
Comparison des donnees simulees des capteurs de SPOT et landsat-D: Application a une region agricole
NASA Astrophysics Data System (ADS)
Saint, Gilbert; Podaire, Alain
La modélisation de la luminance spectrale des objets observés en télédétection permet d'effectuer des simulations de différents capteurs à partir de données obtenues au moyen d'un scanneur DAEDALUS aéroporté : les qualités radiométrique et géométrique ont pu être évaluées par une comparaison avec des données Landsat réelles. L'analyse sur une zone agricole met surtout en évidence le rôle important de l'accroissement de la résolution.
Commande vectorielle d'un moteur asynchrone sans capteur
NASA Astrophysics Data System (ADS)
Ourth, T.
1993-06-01
A field-oriented control strategy for induction machines which does not use mechanical sensors is presented. The rotor flux is observed by a reduced-order Luenberger-type observer based on a model using a stator-fixed reference frame. An estimate of the rotation speed is derived from the flux vector, the measured stator currents and the field orientation angle. Simulations demonstrate that this control strategy performs well even in the presence of parameter variations up to ± 50% (resistances). Ce papier présente la commande par flux orienté d'une machine asynchrone sans capteur de vitesse ou de position. Le flux rotorique est évalué grâce à un observateur d'ordre réduit d'un type voisin de Luenberger travaillant dans un repère fixe statorique. L'estimation de la vitesse est obtenue à partir du module du flux rotorique, des courants statoriques mesurés et de l'angle d'orientation du flux rotorique. Cette étude basée sur des simulations démontre un comportement acceptable de la commande malgré la variation des paramètres comme les résistances de la machine.
2010-03-01
auditeurs soient informés sur les pratiques actuelles mais aussi sur les capteurs et leurs applications . Des orientations technologiques ont été...Mar 2010 Low-Cost Navigation Sensors and Integration Technology ( Capteurs de navigation à faible coût et technologie d’intégration) Research and...to-date with current practices, as well as, information on sensors, algorithms, and applications . Applications were described for navigating in
NASA Astrophysics Data System (ADS)
Vérinaud, Christophe
2000-11-01
Dans le domaine de la haute résolution angulaire en astronomie, les techniques de l'interférométrie optique et de l'optique adaptative sont en plein essor. La principale limitation de l'interférométrie est laturbulence atmosphérique qui entraîne des pertes de cohérence importantes, préjudiciables à la sensibilité et à la précision des mesures. L'optique adaptative appliquée à l'interférométrie va permettre un gain en sensibilité considérable. Le but de cette thèse est l'étude de l'influence de l'optique adaptative sur les mesures interférométriques et son application au Grand Interféromètre à DeuxTélescopes (GI2T) situé sur le Mont Calern dans le sud de la France. Deux problèmes principaux sont étudiés de manière théorique par des développements analytiques et des simulations numériques: le premier est le contrôle en temps réel de la variation des différences de marche optique, encore appelée piston différentiel, induite par l'optique adaptative ; le deuxième problème important est la calibration des mesures de contraste des franges dans le cas de la correction partielle. Je limite mon étude au cas d'un interféromètre multi-modes en courtes poses, mode de fonctionnement principal du GI2T également prévu sur le Very Large Telescope Interferometer installé au Cerro Paranal au Chili. Je développe une méthode de calibration des pertes de cohérence spatio-temporelles connaissant la fonction de structure des fronts d'onde corrigés. Je montre en particulier qu'il est possible d'estimer fréquence par fréquence la densité spectrale des images en courtes poses, méthode très utile pour augmenter la couverture du plan des fréquences spatiales dans l'observation d'objets étendus. La dernière partie de ce mémoire est consacrée au développements instrumentaux auxquels j'ai participé. J'ai développé un banc de qualification du système d'optique adaptative à courbure destiné au GI2T et j'ai étudié l
[Posterior leukoencephalopathy syndrome presenting with bilateral ataxie optique: a case report].
Yamashiro, Kazuo; Kunoki, Makiko; Miura, Yoshiharu; Tomiyama, Junji; Mochizuki, Hideki; Mizuno, Yoshikuni
2005-01-01
We report a 45 years old right-handed woman who developed acute respiratory distress syndrome (ARDS) after the operation for rupture of an ovarian cyst. One week after the onset of ARDS, she presented visual disturbance and Gerstmann syndrome. MRI T2-weighted images demonstrated abnormal high intensity lesions involving the gray and white matter of the occipital lobes bilaterally extending to the parietal lobes. Based on these findings, she was diagnosed as having posterior leukoencephalopathy syndrome (PLES). Her neurologic symptoms gradually improved, however, she started to complain of difficulty in grasping a cup placed on her peripheral visual fields. Neurological examination revealed no visual disturbance, weakness or cerebellar ataxia. She could easily reach objects presented in the central visual field, however, she could not grasp objects presented peripheral visual fields, while she was looking straight ahead. This disorder was observed both in the right and left visual field, whether she used the right hand or the left hand. We thought she had ataxie optique of Garcin. She was noted to have bilateral both direct and crossed ataxie optique. Ataxie optique is characterized by disturbance in reaching objects presented in the peripheral visual field. The underlying pathophysiologic mechanism is believed to be disconnection of the fibers between the primary visual area and the angular gyrus at the parietooccipital junction. Crossed ataxie optique consisting of difficulty in reaching objects presented in the contralateral visual field believed to be caused by disconnection of crossed pathways of the corpus callosum. Ataxie optique in our patient can be explained by disconnection of both direct and crossed fibers. Ataxie optique is sometimes unrecognized by the patient. Our patient suggests that ataxie optique may well be a symptom of PLES.
Statistique des photons d'un laser à 4 niveaux soumis à un pompage optique
NASA Astrophysics Data System (ADS)
Chusseau, L.; Arnaud, J.; Philippe, F.
2002-06-01
Les lasers conventionnels à 4 niveaux peuvent délivrer de la lumière de statistique sous-Poissonienne même lorsqu'ils sont soumis à un pompage optique. Nous retrouvons exactement ces prédictions de l'optique quantique en supposant simplement que les atomes ont des niveaux d'énergie quantifiés interagissant avec un champ électromagnétique classique, la source du bruit optique étant les sauts quantiques entre niveaux. Des formules analytiques sont obtenues pour les deux paramètres clefs de la statistique des photons du laser: le facteur de Fano et la densité spectrale des photons émis.
NASA Astrophysics Data System (ADS)
Aaron, Gilles; Bonnard, Rene
1984-03-01
Dans l'hOpital, le besoin d'un reseau de communication electronique ne cesse de crottre au fur et a mesure de la numerisation des images. Ce reseau local a pour but de relier quelques sources d'images telles la radiologie numerique, la tomodensitometrie, la resonance magnetique nucleaire, l'echographie ultraso-nore etc..., a un systme d'archivage. Des consoles de visualisation interacti-ves peuvent etre utilisees dans les salles d'examens, les bureaux des medecins et les services de soins. Dans un tel systme, trois caracteristiques princi-pales doivent etre prises en compte le debit, la longueur du cable et le nombre de connexions. - Le debit est tr?)s important, en effet, un temps de reponse maxima de quel-ques secondes doit etre garanti pour des images de plusieurs millions d'ele-ments binaires. - La distance entre connexions peut etre de quelques km dans certains grands hopitaux. - Le nombre de connexions au reseau ne depasse jamais quelques dizaines car les sources d'images et les unites de traitement representent des materiels importants, par ailleurs les consoles de visualisation simples peuvent etre groupees en grappe. Toutes ces conditions sont remplies par les transmissions sur fibres optiques. Selon la topologie et la methode d'accNs, deux solutions peuvent etre envisa-gees : - Anneau actif - Etoile active ou passive Enfin, les developpements de Thomson-CSF en composants pour transmissions optiques pour les grands reseaux de tel4distribution nous apportent un support technologique et une production de masse qui diminuera les collts du materiel.
Simulation du fonctionnement de capteurs solaires à air de type tôle et de type absorbeur poreux
NASA Astrophysics Data System (ADS)
Fournier, Michel; Maurissen, Yves
1993-12-01
The comparison between air-heated insolators, no porous and porous plate, often has been made experimentaly. The behaviour model of these insolators permit generalization of the study in the conditions where each insolator is the most performant. La comparaison des capteurs solaires à air à absorbeur de type tôle et de type poreux a été abordée le plus souvent de façon expérimentale. La modélisation du fonctionnement de ces types de capteur permet de généraliser cette comparaison et de définir les domaines de fonctionnement où un type de capteur se montre plus efficace que l'autre.
Developpement de techniques de diagnostic non intrusif par tomographie optique
NASA Astrophysics Data System (ADS)
Dubot, Fabien
Que ce soit dans les domaines des procedes industriels ou de l'imagerie medicale, on a assiste ces deux dernieres decennies a un developpement croissant des techniques optiques de diagnostic. L'engouement pour ces methodes repose principalement sur le fait qu'elles sont totalement non invasives, qu'elle utilisent des sources de rayonnement non nocives pour l'homme et l'environnement et qu'elles sont relativement peu couteuses et faciles a mettre en oeuvre comparees aux autres techniques d'imagerie. Une de ces techniques est la Tomographie Optique Diffuse (TOD). Cette methode d'imagerie tridimensionnelle consiste a caracteriser les proprietes radiatives d'un Milieu Semi-Transparent (MST) a partir de mesures optiques dans le proche infrarouge obtenues a l'aide d'un ensemble de sources et detecteurs situes sur la frontiere du domaine sonde. Elle repose notamment sur un modele direct de propagation de la lumiere dans le MST, fournissant les predictions, et un algorithme de minimisation d'une fonction de cout integrant les predictions et les mesures, permettant la reconstruction des parametres d'interet. Dans ce travail, le modele direct est l'approximation diffuse de l'equation de transfert radiatif dans le regime frequentiel tandis que les parametres d'interet sont les distributions spatiales des coefficients d'absorption et de diffusion reduit. Cette these est consacree au developpement d'une methode inverse robuste pour la resolution du probleme de TOD dans le domaine frequentiel. Pour repondre a cet objectif, ce travail est structure en trois parties qui constituent les principaux axes de la these. Premierement, une comparaison des algorithmes de Gauss-Newton amorti et de Broyden- Fletcher-Goldfarb-Shanno (BFGS) est proposee dans le cas bidimensionnel. Deux methodes de regularisation sont combinees pour chacun des deux algorithmes, a savoir la reduction de la dimension de l'espace de controle basee sur le maillage et la regularisation par penalisation de Tikhonov
Capteurs monopodes pour mesures accélérométriques
NASA Astrophysics Data System (ADS)
Delaite, R.; Valentin, J.-P.
1993-08-01
A new design for accelerometric measurements sensors is described. It uses a plate vibrating in thickness shear mode, maintained by the means of a single holder located at the crystal edge. This mounting does cancel the mechanical and thermal stresses which generally modify the sensor output signal. So the ratio signal/noise of a thickness shear accelerometer is improved and the intrinsic sensitivity is multiplied by a factor 40, by comparison with the sensitivity of a thickness shear plate bonded by the means of two opposite holders. Un nouveau dispositif destiné aux mesures d'accélération est présenté. Il met en œuvre une lame vibrant en cisaillement d'épaisseur, fixée à sa structure de maintien par l'intermédiaire d'une unique liaison. Ce montage permet d'éliminer les contraintes mécaniques et thermiques qui perturbent habituellement le signal de mesure, et qui sont liées soit au montage des éléments du capteur, soit aux variations rapides de température qui interviennent lors de la mise en fonctionnement du capteur. Le rapport signal/bruit d'un accéléromètre à lame vibrant en cisaillement d'épaisseur s'en trouve amélioré et la sensibilité à l'accélération est multipliée par un facteur 40, comparée à celle d'un capteur qui serait constitué d'une lame vibrant en cisaillement d'épaisseur, fixée par deux liaisons diamétralement opposées.
2008-11-01
des travaux dirigés afin que les auditeurs soient informés sur les pratiques actuelles mais aussi sur les capteurs et leurs applications . Des...été consacré aux capteurs et à leurs applications . Le premier document a traité des MEMS. Les avantages spécifiques des MEMS du point de vue de la...EN-SET-116(2008) Low-Cost Navigation Sensors and Integration Technology (Les capteurs de navigation à bas coût et la technologie d’intégration
2009-04-01
capteurs , des signaux et des données) Research and Technology Organisation (NATO) BP 25, F-92201 Neuilly-sur-Seine Cedex, France RTO-EN-SET-133...Multistatiques : Fusion des capteurs , des signaux et des données) The material in this publication was assembled to support a Lecture Series under the...Surveillance et Reconnaissance Multistatiques : Fusion des capteurs , des signaux et des données (RTO-EN-SET-133) Synthèse Les systèmes radar
2009-03-01
informés sur les pratiques actuelles mais aussi sur les capteurs et leurs applications . Des orientations technologiques ont été décrites pour la...EDUCATIONAL NOTES EN-SET-116(2009) Low-Cost Navigation Sensors and Integration Technology (Les capteurs de navigation à bas coût et la technologie...information on sensors and applications . Technology trends were described for navigating in difficult urban, indoor, and underground environments
Vers la génération de chats de Schrödinger optiques
NASA Astrophysics Data System (ADS)
Ourjoumtsev, A.; Laurat, J.; Tualle-Brouri, R.; Grangier, Ph.
2006-10-01
Nous réalisons actuellement une implémentation expérimentale d'un protocole de création de petits chats de Schrödinger optiques. Ces états présentent un fort intérêt dans le domaine de l'information quantique, notamment dans des protocoles de calcul universel ou de métrologie quantique [1,2].
Realisation de composants tout-fibre passifs bases sur des fibres optiques a deux coeurs
NASA Astrophysics Data System (ADS)
Jacob Poulin, Anne C.
2002-01-01
Les composants passifs tout-optique sont des elements de choix dans les systemes de communications optiques. Cette these presente l'utilisation experimentale de fibres a deux coeurs dissimilaires pour la realisation de filtres passe-bande. Les fibres a deux coeurs ont la particularite de favoriser un couplage d'un coeur a l'autre a intervalles reguliers lorsque les coeurs sont exactement identiques. Dans le cas ou une legere difference apparait, ce couplage est rapidement reduit a zero. La premiere partie de la these montre comment, par l'emploi d'une geometrie de fibre appropriee, il est possible de compenser cette desyntonisation et de fabriquer des coupleurs 100%. Les filtres obtenus ayant toutefois une largeur de bande trop grande pour les besoins du marche des communications optiques, il est montre dans la deuxieme partie de la these comment, en alliant la technologie des reseaux de Bragg avec celle des coupleurs, il est possible de realiser des filtres operant en transmission et possedant d'excellentes caracteristiques spectrales, toujours avec ces memes fibres a deux coeurs.
Traitement de la neuromyélite optique de Devic durant de la grossesse
Daouda, Moussa Toudou; Obenda, Norlin Samuel; Assadeck, Hamid; Camara, Diankanagbe; Djibo, Fatimata Hassane
2016-01-01
La neuromyélite optique de Devic est une pathologie inflammatoire démyélinisante du système nerveux central qui affecte électivement la moelle spinale, le nerf optique et les régions cérébrales à haute expression d’antigènes aquaporine 4. Il s’agit d’une pathologie auto-immune sévère due à des auto-anticorps dirigés contre l’aquaporine 4, à taux de morbidité et de mortalité élevé. Contrairement à d’autres pathologies inflammatoires notamment la sclérose en plaques ou polyarthrite rhumatoïde, la grossesse n’exerce aucune influence sur l’activité de la neuromyélite optique d’où la nécessité d’instaurer un traitement de fond durant toute la grossesse. La corticothérapie représente le traitement de premier choix de la neuromyélite optique durant la grossesse. D’autres traitements peuvent également être utilisés notamment le rituximab, certains immunosuppresseurs, les immunoglobulines. Le traitement par immunosuppresseurs ou rituximab est proposé lorsque la corticothérapie au long cours est contre-indiquée ou en cas d’inefficacité à celle-ci ou encore lorsque les effets secondaires sont intolérables. Les immunoglobulines sont administrées en cas de poussées sévères de la neuromyélite optique qui ne répondent pas aux bolus de methylprednisolone. Les immunoglobulines peuvent également être poursuivies seules à la dose 0,4g/kg/j toutes les 6 à 8 semaines jusqu’à l’accouchement. La plasmaphérèse est également une bonne alternative aux bolus de methylprednisolone lorsque les poussées sont très sévères. PMID:27800085
NASA Astrophysics Data System (ADS)
Smektala, F.; Bureau, B.; Adam, J. L.; Lucas, J.
2002-06-01
Les énergies de phonons élevés des verres à base de silice limitent leurs applications dans l'infrarouge. Il devient donc incontournable de créer des verres à plus faible énergie de phonons pour développer une optique passive guidée opérationnelle dans l'IR moyen et pour réaliser de nouveaux guide d'ondes optiques activés par des lanthanides pouvant jouer le rôle soit d'amplificateurs optiques soit de fibres lasers. Les compositions de verres stables répondant à ces critères sont exceptionnelles et appartiennent aux familles chimiques des fluorures et des chalcogénures. Les verres de fluorures, convenablement dopés par des terres rares, ont permis la réalisation d'amplificateurs optiques opérant dans la fenêtre télecom de la silice (1.3 μm avec le praséodyme, 1.45 μm avec le thulium et 1.55 μm avec l'erbium. Les verres de chalcogénures permettent la réalisation de fibres opérationnelles jusqu'à 12 μm mais seulement pour des applications courtes distances telles que le transport d'énergie moyenne, la radiométrie à l'ambiante et la spectrométrie IR déportée par fibre optique de molécules chimiques ou de tissus biologiques.
1980-02-01
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Contributions a L'etude de Dispositifs D'optique Integree
NASA Astrophysics Data System (ADS)
Touam, Tahar
Cette these contient des contributions a l'etude de deux champs du vaste domaine de l'optique integree. A cet effet, nous avons divise notre travail en deux grandes parties:. Dans une premiere partie, nous traitons le probleme de la realisation d'une nouvelle classe de guides d'onde planaires utilisables dans le domaine de longueur d'onde de l'infrarouge moyen (infrarouge thermique), domaine ou l'apparition anticipee de fibres optiques a pertes extremement faibles rendraient fort interessante l'existence de tels guides d'onde planaires. Dans un premier temps, nous presentons une etude analytique originale d'une structure planaire a profil d'indice gradue, suivie d'une analyse d'un guide canal base sur cette structure. Dans un deuxieme temps, nous decrivons le procede de fabrication par pulverisation atomique d'un guide planaire forme d'arseniure de gallium (AsGa) sur du dioxyde de silicium (SiO_2 ), combinaison de materiau compatible avec l'infrarouge moyen. Finalement, nous presentons une etude de conception d'un reseau de surface destine a coupler la lumiere dans un tel guide, les autres methodes traditionnelles de couplage semblant peu appropriees aux environs de lambda = 10 mum. Dans une deuxieme partie, nous traitons le probleme de la jonction Y en optique integree, jonction qui soufre de pertes tres importantes des que l'angle d'ouverture devient interessant pour le concepteur de circuits integres optiques. L'analyse est basee sur la methode numerique dite BPM (Beam Propagation Method; methode de propagation du faisceau) qui fait l'objet d'un bref rappel. Nous poursuivons avec l'etude et l'optimisation d'une nouvelle jonction Y dont l'essence est l'utilisation du phenomene de diffraction a travers trois fentes de phase. Nous obtenons ainsi une tres bonne jonction, separant proprement le faisceau, a une ouverture de 10 degres. Finalement, nous faisons un rappel d'un profil d'indice dit "ideal" pour guides courbes et nous proposons l'utilisation de tels guides
Fibre optique Ã la maison en Pays de Gex et de Bellegarde
None
2016-07-12
Le Syndicat Intercommunal d’Electricité de l’Ain(SIEA) déploie un réseau FTTH (Fiber To The Home) de fibres optiques dans le département de l’Ain vers l’ensemble des habitations. Le déploiement sur la zone pilote du Pays de Gex et du Bassin Bellegardien arrive dans la phase terminale vers les habitations. Le SIEA présentera ses activités, l’état du développement du réseau, les implications d’une connexion fibre optique et les procédures d’abonnement. La présentation sera donnée en Français. -------------------------------------------------------------------------------------------------------------------------------Public conference "Optical fiber To The Home in Pays de Gex et de Bellegarde" Michel Chanel et Jean Paul Goy (SIEA) Wednesday, 19th May at 11.30 hrs., Council Chamber, CERN The ‘’ Syndicat Intercommunal d’Electricité de l’Ain’’(SIEA) is deploying an optical fiber network FTTH (Fiber To The Home) in the Ain department towards the ensemble of houses. The installation on the pilot areas of Pays de Gex and Bassin Bellegardien is arriving in the phase of connecting houses. The SIEA will show its activities, the state of the network development, the implications of an optical fiber connection and the contract procedures. The presentation will be given in French
Applications de la tranformee en ondelettes au traitement de l'information optique
NASA Astrophysics Data System (ADS)
Deschenes, Sylvain
La these presente l'apport d'un outil mathematique recemment decouvert, la transformee en ondelettes, au traitement de l'information optique. Les ondelettes continues sont d'abords introduites et leur realisation optique est presentee. Ensuite, une ondelette repondant aux equations de Maxwell est developpee. Cette derniere permet de tisser des liens entre la transformee en ondelettes et le principe de Huygens utilise pour etudier la diffraction scalaire. La possibilite d'utiliser cette ondelette pour generer des faisceaux non diffractants est egalement discutee. Dans un deuxieme temps, les ondelettes discretes sont utilisees dans le but d'extraire des informations pertinentes dans une banque d'images infrarouges. Ces images representent les vues de vehicules prises a tous les cinq degres. La transformee en ondelettes genere une analyse multiresolution permettant d'extraire des contours moins bruites. Cette information est alors traitee par de nouveaux algorithmes de reconnaissance de forme dans un espace qui caracterise de facon invariante les objets 3-D.
Fibre optique à la maison en Pays de Gex et de Bellegarde
2010-05-19
Le Syndicat Intercommunal d’Electricité de l’Ain(SIEA) déploie un réseau FTTH (Fiber To The Home) de fibres optiques dans le département de l’Ain vers l’ensemble des habitations. Le déploiement sur la zone pilote du Pays de Gex et du Bassin Bellegardien arrive dans la phase terminale vers les habitations. Le SIEA présentera ses activités, l’état du développement du réseau, les implications d’une connexion fibre optique et les procédures d’abonnement. La présentation sera donnée en Français. -------------------------------------------------------------------------------------------------------------------------------Public conference "Optical fiber To The Home in Pays de Gex et de Bellegarde" Michel Chanel et Jean Paul Goy (SIEA) Wednesday, 19th May at 11.30 hrs., Council Chamber, CERN The ‘’ Syndicat Intercommunal d’Electricité de l’Ain’’(SIEA) is deploying an optical fiber network FTTH (Fiber To The Home) in the Ain department towards the ensemble of houses. The installation on the pilot areas of Pays de Gex and Bassin Bellegardien is arriving in the phase of connecting houses. The SIEA will show its activities, the state of the network development, the implications of an optical fiber connection and the contract procedures. The presentation will be given in French
Fabrication et etude de cristaux photoniques pour les longueurs d'onde de telecommunication optique
NASA Astrophysics Data System (ADS)
Aboudihab, Ismail
Nous avons fabrique et etudie des cristaux photoniques bidimensionnels et tridimensionnels. Les cristaux 3D sont constitues de microbilles de polystyrene autoassemblees. La structure inverse en BaTiO3 a ete aussi fabriquee, ou l'on remplace l'espace entre les microbilles par du BaTiO3, alors que les microbilles sont eliminees. Nous avons essaye en particulier de comprendre les differents phenomenes qui influencent la cristallisation de ces structures afin d'obtenir des films de meilleure qualite. Les cristaux bidimensionnels, constitues de cylindres vides imbibes dans un semiconducteur (As2S3 ou Si), sont obtenus par holographie laser. Nous avons montre que cette technique est tres interessante pour la production en serie de ces structures. Des guides d'ondes, des coupleurs, et des jonctions Y, imbibes dans des cristaux photoniques bidimensionnels, ont aussi ete fabriques. Des mesures optiques et des simulations numeriques ont ete menees dans le but de caracteriser ces structures.
Gliome du nerf optique révélé par un strabisme divergent
Handor, Hanan; Laghmari, Mina; Hafidi, Zouheir; Daoudi, Rajae
2014-01-01
Les gliomes des nerfs optiques sont des tumeurs rares qui s'observent essentiellement chez l'enfant. L'exophtalmie et le strabisme sont les principaux signes révélateurs de la maladie. La neuroimagerie et notamment l'imagerie par résonnance magnétique est d'un grand apport dans le diagnostic et le suivi de ces tumeurs. La prise en charge thérapeutique de ces gliomes fait appel à différents moyens: l'exérèse chirurgicale, la chimiothérapie, la radiothérapie ou l'abstention sous surveillance. Les indications doivent être discutées au cas par cas. PMID:25309656
Bruit thermique et effets quantiques dans une cavité optique de grande finesse
NASA Astrophysics Data System (ADS)
Caniard, T.; Briant, T.; Heidmann, A.; Pinard, M.
2006-10-01
Nous nous intéressons aux bruits dans les mesures optiques de très grande sensibilité et aux limites associées. Une des limitations fondamentales des mesures interférométriques, telles que les détections d'ondes gravitationnelles, est liée aux fluctuations de la pression de radiation exercée par la lumière sur les miroirs. Celle-ci induit des corrélations quantiques entre la position des miroirs et les fluctuations de la lumière. L'observation de ces effets quantiques ouvrirait de nombreuses perspectives: étude de la limite quantique standard, production d'états comprimés, réalisation d'une mesure quantique non destructive ldots
Détermination du courant d'arc par utilisation de fibres optiques fluorescentes
NASA Astrophysics Data System (ADS)
Melouki, B.; Lieutier, M.; Lefort, A.
1997-02-01
In this paper, we develop a method of determination of the arc current in a circuit breaker during the interruption. This method is based on the use of an optoelectronic system using a fluorescent optical fibre coupled with a photodetector. The current wave is obtained from the light wave detected by the detection system. Dans cet article, nous développons une méthode permettant de déterminer le courant traversant un disjoncteur lors d'une coupure. Cette méthode utilise un système optoélectronique constitué d'une fibre optique fluorescente couplée à un photodétecteur. L'onde du courant d'arc est obtenue à partir de l'onde lumineuse reçue par le système de détection.
Champs optiques issus de structures sub-longueur d'onde
NASA Astrophysics Data System (ADS)
Gay, G.; Alloschery, O.; Mathevet, R.; Lezec, H.; Weiner, J.
2006-10-01
Nous présentons les résultats de nos études de la réponse optique de structures sub-longueur d'onde gravées sur des films d'argent. Nous avons réalisé des mesures de l'intensité transmise et des spectres angulaires d'émission de ces structures en fonction de leur géométrie (forme des motifs et distance entre ceux-ci). Les résultats nous permettent de caractériser en phase, amplitude et longueur d'onde le champ évanescent à l'interface air/métal.
Propriétés magnéto-optiques des diastéréoisomères
NASA Astrophysics Data System (ADS)
Ruchon, T.; Thépot, J.-Y.; Vallet, M.; Le Floch, A.
2006-10-01
Les molécules énantiomères présentent des activités optiques opposées, mais des rotations Faraday égales. Nous démontrons, par une mesure différentielle, que les stéréoisomères méso, qui, par compensation interne, n'ont pas d'activité optique, présentent au contraire des effets Faraday différents de leurs stéréoisomères chiraux. Ce résultat, obtenu sur l'acide tartrique, est en accord avec les valeurs théoriques issues d'un modèle d'interaction dipolaire.
NASA Astrophysics Data System (ADS)
Marengo, Stephanie
Dans cette etude, nous avons developpe un amplificateur a colorant possedant ces deux caracteristiques. Le colorant choisi, l'iodure de 3,3'-dimethyloxatricarbocyanine (methyl-DOTCI), possede un epaulement dans la bande d'absorption a 620 nm ce qui convient bien a notre pompe femtoseconde. De plus, son maximum de fluorescence est a 720 nm ce qui est particulierement interessant dans le cas des etudes avec des tissus biologiques humains. En effet, la fenetre dite "therapeutique" se situe dans les longueurs d'onde rouge et proche infrarouge. Le phenomene d'amplification, qui se produit dans des conditions experimentales precises, est en fait une emission stimulee du colorant qui est largement favorisee par rapport a sa fluorescence naturelle (emission spontanee). L'arrivee du signal incident, dont la longueur d'onde correspond au saut energetique entre l'etat fondamental et l'etat excite ou se trouvent les molecules, provoque une avalanche coherente de celles-ci vers l'etat fondamental generant ainsi l'emission stimulee. Une des conditions necessaires pour l'obtention d'un gain eleve est que la duree de l'impulsion de pompe soit inferieure au temps de relaxation des molecules ainsi qu'inferieure au temps requis pour effectuer un trajet dans la cellule de colorant. Ceci nous a permis d'amplifier un signal incident par un facteur entre 103 et 104. De plus, ce gain eleve n'est observe qu'a l'interieur d'une fenetre temporelle d'environ 10 picosecondes. Nous avons integre cet amplificateur a notre montage de transillumination afin d'acquerir des images d'un patron de lignes opaques immerge dans un milieu diffusant liquide. Des images de lignes ayant une resolution spatiale de 200 mum ont ete obtenues. La cible etait placee au centre d'un melange contenant des proportions variables de lait et d'eau. Deux longueurs de trajet optique dans la solution ont ete utilisees: 30 et 50 mm. Pour determiner les proprietes optiques de notre milieu diffusant, nous avons mis au point
Réponse diélectrique de surface des phonons optiques d'un film de cristal ionique
NASA Astrophysics Data System (ADS)
Lambin, Ph.; Senet, P.; Castiaux, A.; Philippe, L.
1993-06-01
The paper begins with a short review on the theory of the surface dielectric response function of optical phonons in thin films, which is an important quantity for the understanding of various surface phenomena. The dielectric response of surface phonons to infra-red excitations is analysed with some details for two test cases: a SiO2(0001) self-supported film and NaCl(001) slabs on a thick Ge substrate. The results obtained from lattice-dynamics calculations for short wave vectors are compared with the predictions of electrostatics. The latter is shown to provide a valuable description — at the level of the energy resolution achieved today in electron-energy-loss spectroscopy — of the surface dielectric response function, even for the thinnest films (11 Å) considered in this paper. L'article commence par une dérivation rapide de la fonction de réponse diélectrique de surface des phonons optiques d'un film. Cette fonction de réponse est une grandeur fondamentale des matériaux qui intervient dans l'étude de nombreux phénomènes de surface. La réponse diélectrique des phonons de surface est analysée avec détail pour deux systèmes modèles : (a) un film de SiO2(0001) auto-supporté et (b) des couches de NACl(001) sur un substrat massif de Ge. Les résultats que donne la dynamique cristalline pour ces deux systèmes sont comparés aux prédictions d'une approche basée sur l'électrostatique. On montre ainsi qu'à l'échelle des résolutions en fréquence couramment atteintes en spectroscopie de perte d'énergie d'électrons, l'électrostatique fournit une description valable de la réponse diélectrique de surface à grande longueur d'onde, même pour les films les plus minces examinés ici (11 Å).
Conception d'un capteur intelligent pour la détection des vapeurs de styrène dans l'industrie
NASA Astrophysics Data System (ADS)
Agbossou, Kodjo; Agbebavi, T. James; Koffi, Demagna; Elhiri, Mohammed
1994-10-01
The techniques of measurement of toxic gases are nowadays based on the semiconductor type sensors. The modelling and the electronic processing of their signals can be used to improve the accuracy and the efficiency of the measurement. In this paper, an intelligent system using a semiconductor sensor has been designed for the detection of the styrene vapors. A set of the environmental parameters sensors such as the temperature, the pressure and the humidity, is added to the basic sensor and allows a precise detection of the styrene vapors in air. A microcontroller and a communication interface, that are included in the control system and in the data processing system, provide the local intelligence. The linearization routines of the differents sensors are in the memory of the microcontroller. The system made of the sensors, of the amplification circuits, of the microcontroller and of the communication network between the smart sensor and the computer is analysed. A laboratory test of the device is presented and the accuracies and efficiencies of the differents sensors are given. Les techniques fiables de quantification des gaz polluants sont aujourd'hui basées sur l'utilisation des détecteurs à récepteurs chimiques et sur des capteurs à semiconducteurs. La modélisation et le traitement numérique des signaux résultants sont importants pour une mesure efficace et précise dans un milieu donné. Dans cet article, un capteur intelligent, utilisant un détecteur de gaz type semiconducteur a été réalisé pour la détection des vapeurs de styrène. Un ensemble de détecteurs des paramètres environnementaux, tels que la température, la pression et l'humidité, ajoutés au capteur de styrène, permettent de mesurer avec un bon contrôle les vapeurs de styrène dans l'air. Le système de contrôle et de gestion local des données est constitué d'un microcontrôleur et d'une interface de communication. Le microcontrôleur contient dans sa mémoire toutes les
Réponses transitoires de films de TiO{2}, capteurs résistifs du gaz oxygène
NASA Astrophysics Data System (ADS)
Jérisian, R.; Loup, J. P.; Gautron, J.
1991-07-01
We analyse the mecanisms of the transient response of TiO2-film EGO (Exhaust Gas Oxygen) sensors to partial oxygen pressure. This analysis, in agreement with the steady-state behaviour, is based upon the diffusion theory. Moreover, our results corroborate the decrease of the response time when Pt is incorporated to the film or when the thickness of the film is lessened. Nous analysons les réponses transitoires de capteurs résistifs de films de TiO2 soumis à des changements de pression partielle d'oxygène. Cette analyse fait appel à la théorie de la diffusion et reste en accord avec l'étude du comportement statique de ces capteurs. Les temps de réponse mesurés décroissent avec l'incorporation de Pt ou la diminution de l'épaisseur du film.
Système de traitement acousto-optique de signaux numériques
NASA Astrophysics Data System (ADS)
Goutin, P.; Logette, P.; Rouvaen, J. M.; Bridoux, E.
1991-10-01
The transversal filter is a fundamental device in numerical signal processing. Among all available techniques, the acousto-optic convolution is very well matched to this function. Some penalties occur however, for very long input signals, owing to the physical configuration of the convolver and to the propagation of acoustic waves in its bulk. This calls for the study of a convenient computation algorithm taking all the constraints into account. The realization of an hybrid processor enabled us to evaluate its main characteristics using experiments like autoconvolution, F.I.R. filtering, Golay's and Barker's codes or matrix multiplication. Since the built system is actually a prototype, a number of extensions and improvements are presented, which may lead to the optimization of the processing speed. L'élément fondamental du traitement numérique du signal est le filtre transversal. Parmi les techniques utilisables, la convolution acousto-optique est particulièrement bien adaptée à cette fonction. Les difficultés de cette opération, pour le traitement d'un signal d'entrée relativement long, proviennent de la configuration propre du convoluteur et du phénomène de propagation. Celles-ci vont nécessiter l'étude d'un algorithme de calcul respectant certaines contraintes. La réalisation du processeur hybride nous a permis d'en évaluer les caractéristiques à partir des résultats expérimentaux tels que : autoconvolutions, filtrage F.I.R., corrélations, codes de Golay, codes de Barker et multiplication matricielle. Le fait même de la nature prototype du système réalisé nous amène à présenter un grand nombre d'extensions et d'améliorations qui permettent d'optimiser fortement la vitesse de traitement.
Etude des propriétés optiques des couches minces de CuInS2 et d'In-S " Airless spray "
NASA Astrophysics Data System (ADS)
Kamoun, N.; Bennaceur, R.; Frigerio, J. M.
1994-05-01
In this work we have studied the optical properties of the thin CuInS2 and In-S layers prepared by airless spray " P.S.A. ". The study of the optical properties from the ellipsometric measure realized in the interval energy of incident photons [1.5-4] eV, has showed that the refraction index n_1 and the extinction coefficient k_1 vary in the interval [1.8-2.3] and [0.45-0.80] respectively. The absorption coefficient α of the thin CuInS2 layers realized for different ratios x of the concentrations in the spray solution (x =frac[CuI][InIII]) is high with values varied between (5 × 10^4 and 18 × 10^4 cm^{-1}). The direct gap energy of the thin CuInS2 layers of the order of 1.38 eV. In the same way, we study the spectrum variation of n_1 (λ) and k_1 (λ) of the thin In-S layers, realized for two values of ratio y of the concentration in the spray solution (y=frac{[In^{3+}]}{[S^{2-}]}), shows that for the value of y = 0.6 (material β-In2S3) the refraction index is higher than that of the thin layer obtained for the value of y = 0.75 (material In6S7) [1], and that the extinction coefficient is lower than that of In6S7. For In-S thin layers, α is also high with values varing between 2×10^4 and 12×10^4 cm^{-1}. The direct band gap of materials β-In2S3 and In6S7 are 2.22 eV and 1.94 eV respectively. The heat treatment under vacuum at 573 K during two hours improves the optical quality of the thin " p " type CuInS2 Layer. Dans ce travail nous avons étudié les propriétés optiques des couches minces de CuInS2 et d'In-S réalisées par pulvérisation chimique réactive sans air " P.S.A. ". L'étude des propriétés optiques des couches minces de CuInS2, à partir des mesures ellipsométriques effectuées dans le domaine des photons incidents [1,5-4] eV, a révélé que l'indice de réfraction n_1 et le coefficient d'extinction k_1 varient respectivement dans les domaines [1,8-2,3] et [0,45-0,80]. Le coefficient d'absorption α, des couches minces de CuInS2 r
NASA Astrophysics Data System (ADS)
Gagne, Philippe
Cette recherche vise à la mise en OEuvre optique de la reconnaissance des images en utilisant une mire d'anneaux afin de générer des vecteurs caractéristiques qui seront ensuite classifiés par un réseau de neurones. On proposera deux architectures originales: une qui permettra la reconnaissance invariante sous rotation en utilisant un corrélateur conjoint; l'autre montage permettra une classification en parallèle de plusieurs images grâce à la capacité des mires d'anneaux de compresser l'information. Ce dernier montage est basé sur un corrélateur 4F. On présentera des résultats optiques expérimentaux pour ces deux montages. Pour arriver à des résultats concluants on analysera le comportement des vecteurs obtenus à partir d'une mire d'anneaux, on introduira une règle d'apprentissage optimisant le pic de corrélation en réduisant les pics parasites et on corrigera à l'aide d'un algorithme génétique les modulations de phases générées par le modulateur spatial à cristaux liquides.
Orientation photoinduite de nouvelles molécules pour l'optique non linéaire
NASA Astrophysics Data System (ADS)
Ngan, N. T. K.; Dumont, M.
2002-06-01
Dans les films de polymères utilisés pour les composants de télécommunication, l'orientation photoinduite de molécules de colorants permet de réaliser une biréfringence ou une non centrosymétrie (X^{(2)}). Le mécanisme d'orientation comporte un pompage optique sélectif (“hole buming angulaire”), suivi, soit d'une photodégradation, soit d'un retour à l'état initial, accompagné d'une rotation (“redistribution angulaire”). Seul ce second cas conduit à une orientation importante, par accumulation des molécules dans la direction la moins pompée. C'est le cas des molécules photoisomérisables de façon réversible, tels les azobenzènes. Nous présentons ici une nouvelle molécule azoïque octupolaire qui est un excellent candidat pour l'orientation tout-optique.
Proprietes optiques des heterostructures contraintes de type II Ga(x)In(1-x)P/InP
NASA Astrophysics Data System (ADS)
Chennouf, Abderrahim
Cette these porte sur l'etude des proprietes optiques des heterostructures contraintes GasbxInsb1-xP/InP deposees sur des substrats d'InP avec une concentration de Ga inferieure a 20%. Ces heterostructures, fabriquees a l'Ecole Polytechnique de Montreal par la technique d'epitaxie en phase vapeur aux organo-metalliques (E.P.V.O.M), sont composees de barrieres de GasbxInsb1-xP contraintes en tension biaxiale (inferieure a 1%) et de puits d'InP non contraints. Nous avons etudie l'effet des contraintes sur les transitions observees dans les spectres d'absorption optique et de photoluminescence des structures volumiques contraintes GasbxInsb1-xP/InP deposees sur le meme substrat. Auparavant, nous nous sommes assures de la tres bonne qualite des echantillons en correlant les parametres structuraux obtenus par les mesures de rayons X et les spectres de photoluminescence. Ces resultats nous ont permis d'entamer l'etude des heterostructures en question. L'utilisation du modele de Bastard-Marzin, base sur l'approximation de la masse effective et dans lequel les effets des contraintes sont pris en compte, nous a permis de calculer les niveaux confines et de deduire l'alignement de bandes pour ce systeme qui est crucial pour la comprehension des proprietes optiques et electroniques. Les resultats trouves montrent que les electrons sont confines dans les puits d'InP et les trous legers dans les barrieres de GasbxInsb1xP formant ainsi une configuration de bande de type II, tandis que les trous lourds sont dans les puits. Cette delocalisation spatiale des porteurs confines entraine des proprietes particulierement interessantes que nous avons mis en evidence en combinant differentes techniques optiques telles que l'absorption optique, la photoluminescence en regime continu et en excitation. Nous avons montre que dans le cas des super-reseaux, la transition qui apparai t dans les spectres de photoluminescence a plus basse energie que celle de l'exciton libre est associee a la
2015-02-01
exercise held in March of 2012 on the SW US border was well attended by participating Nations. This included SASNet from Canada and Pearls of Wisdom system...personnel (STO-TR-SET-158) Synthèse Les travaux menés par le groupe de travail « Systèmes de détection multi-capteurs terrestres autonome destinés à...objectifs sur le champ de bataille. Le groupe de travail a insisté sur les technologies de détection autonomes à faible coût afin de répondre au besoin
NASA Astrophysics Data System (ADS)
Mas, Sebastien
Les mesures satellitaires de couleur des oceans sont largement determinees par les proprietes optiques inherentes (IOPs) des eaux de surface. D'autre part, le phytoplancton de petite taille (<20 mum) est le plus souvent dominant dans les oceans, et peut donc etre une source importante de variation des IOPs dans les oceans. Dans ce contexte, le but principal de ce doctorat etait de definir l'impact du phytoplancton (<20 mum) sur les variations des proprietes optiques de l'Estuaire et du Golfe du Saint-Laurent (Canada). Afin d'atteindre cet objectif, il etait necessaire de determiner en milieu controle les facteurs de variabilite des proprietes optiques cellulaires et des IOPs du phytoplancton (<20 mum) des eaux du Saint-Laurent, et d'evaluer la contribution du phytoplancton (<20 mum) aux proprietes optiques totales des eaux du Saint-Laurent. Des experiences en laboratoire ont montre que les variations des proprietes optiques des cellules phytoplanctoniques soumises a un cycle jour-nuit, ainsi qu'a des changements concomitants d'intensite lumineuse, peuvent contribuer significativement a la variabilite des proprietes optiques observee en milieu naturel. D'autres experiences ont, quant a elles, mis en evidence que les variations des proprietes optiques des cellules phytoplanctoniques dues aux phases de croissance peuvent alterer les IOPs des oceans, particulierement pendant les periodes de floraison. De plus, la presence de bacteries et de particules detritiques peut egalement affecter la variabilite des IOPs totales, notamment la diffusion. Au printemps, dans l'Estuaire et le Golfe du Saint-Laurent, la contribution du phytoplancton <20 mum aux IOPs presentait des differences regionales evidentes pour les proprietes d'absorption et de diffusion. En plus de la variabilite spatiale, les proprietes optiques cellulaires presentaient des variations journalieres, et ce particulierement pour le picophytoplancton. Enfin, la plupart des differences observees dans les
Réduction de bruit quantique spatiale et mesures de petits déplacements en optique
NASA Astrophysics Data System (ADS)
Treps, N.; Maître, A.; Fabre, C.; Andersen, U.; Buchler, B.; Lame, P. K.; Bachor, H. A.
2002-06-01
L'étude des images optiques au niveau quantique nécessite de prendre en compte la structure multimode transverse de la lumière. Dans le cas particulier d'une mesure de position d'un faisceau lumineux effectuée par un détecteur à deux zone, on montre qu'il est nécessaire, si on veut améliorer la précision des mesures en réduisant le bruit quantique de la lumière, d'utiliser deux modes transverses. Nous présentons la première réalisation expérimentale d'une réduction de bruit spatiale, ce qui nous permet ensuite d'effectuer des mesures de petits déplacements sous la limite quantique standard.
Propriétés optiques du silicium mésoporeux et ses applications potentielles
NASA Astrophysics Data System (ADS)
Lévy-Clément, C.; Bastide, S.
2002-04-01
Une couche de silicium poreux formée électrochimiquement à la surface de l'émetteur d'une jonction p-n+ peut jouer efficacement le rôle d'une couche antireflet pour les cellules solaires au silicium. En ajustant la densité de courant et le temps de formation, des simple et double-couches antireflet aux propriétés optiques optimisées ont pu être réalisées, conduisant à des réflectivités effectives respectives de 7.3 et 2.7 % sur l'ensemble du spectre solaire utile pour les cellules (400-1000 nm). De hauts rendements de conversion de l'énergie solaire, de l'ordre de 13-13.4 %, sont ainsi actuellement obtenus pour des cellules au silicium multicristallin avec une couche antireflet de silicium poreux.
NASA Astrophysics Data System (ADS)
Fall, H.; Charon, W.; Kouta, R.
2002-12-01
Ces dernières décennies, des activités significatives dans le monde étaient dirigées autour du contrôle actif. Le but de ces recherches était essentiellement d'améliorer les performances, la fiabilité et la sécurité des systèmes. Notamment dans le cas des structures soumises à des vibrations aléatoires. D'importants travaux ont été consacré à l'utilisation des “matériaux intelligents” comme capteurs et actionneurs. Cette article propose l'analyse de la fiabilité des systèmes mécaniques en étudiant les pannes des actionneurs ou des capteurs. L'effet de ces pannes sur la stabilité et la performance du système y est démontré. Les méthodologies de conception y sont rappelées. Des exemples numériques sont fournis à travers le contrôle d'un panneau sous chargement dynamique pour illustrer la méthode proposée.
Les métamatériaux, des micro-ondes à l'optique : théorie et applications
NASA Astrophysics Data System (ADS)
Kante, B.
2010-04-01
Cet article constitue une contribution originale et importante à la compréhension à la fois théorique et expérimentale des métamatériaux en micro-ondes et en infrarouge. Nous avons réalisé et caractérisé sur silicium des nano-structures metallo-diélectriques, briques de base des métamatériaux infrarouge et optique. Des caractérisations optiques exhaustives ont été réalisées pour la première fois sur ces structures en amplitude et en phase par interférométrie. Des topologies plus simples de métamatériaux d’un point de vue technologique et des performances optiques ont été introduites, et leur potentiel démontré dans la réalisation de fonctions aussi complexes que la réfraction négative, le couplage de mode plasmoniques, les nano senseurs pour la biologie et l’invisibilité électromagnétique en infrarouge. Les transformations d’espace, et le nouveau paradigme qu’elles offrent à l’optique, rendant possible une ingénierie de l’espace pour les photons ainsi que leur implémentation par métamatériaux ont été présentés par la première démonstration expérimentale d’une cape d’invisibilité non magnétique.
NASA Astrophysics Data System (ADS)
Koubaa, Zied
The communication network and the detection mechanisms are two critical systems in a plane. Their performance has a direct impact on aircrafts. This is of particular interest for avionics designers, who have increasingly invested more and more in the development of these elements. As a part of a project in this domain, we introduce the design and the development of a smart interface for position sensors dedicated to flights (Smart Sensor Interface - SSI). This interface will serve to connect sensors of different technologies (electromagnetic, optical and MEMS) to the new communication network, AFDX. The role of this interface is to generate an appropriate excitation signal for certain types of sensors (R/LVDT), and to treat, demodulate, and digitize their output signals. The proposed interface is thus composed of a Signal Acquisition Path (SAP) and an Excitation Signal Generation (ESG). By adopting the Integrated Modular Avionics architecture (IMA), we can minimize the size of the classic interface, reduce its energy consumption and improve its reliability and its performance. The focus of our design is particularly on the Data Acquisition Path (DAP). An Architecture characterized by a high resolution (14 bits) and a low latency (1.2 ms) of this module is introduced and developed in this prestigious work. This architecture was developed after a wellconducted study of existing solutions found in literature work and a detailed analysis of the problems arise in the design and implementation of this system (DAP). The conversion of the sensor signal into a digital signal is the most important step in acquiring data, as it sets the resolution of the acquired information and generates the majority of its latency. This module can also affect the reliability and stability of the system. Among different models and architectures, the Delta-Sigma analog-to-digital converter (ADC) is preferred for this application (for better resolution). This converter is formed by an analog
2000-05-01
structuraux du controle actif et flexible des aeronefs] To order the complete compilation report, use: ADA388195 The component part is provided here to...fibres optiques, de 84 d’un facteur 2 capteurs de pression, ainsi que de deux: potentiom~tres pour mesurer la rotation de la Cette confrontation a...gouverne caisson * palette d’excitation * encastrement au mur * 250 capteurs ( pression, jauge, acc~l6romnbtre, fibre optique) guen7 gouverne dispositif de
NASA Astrophysics Data System (ADS)
Bertrand, F.; Paraire, N.; Dansas, P.; Moresmau, N.
1994-07-01
Numerous devices used in the field of photonics and optronics are made of semiconductor multilayered structures including a nonlinear waveguide and a grating coupler. Optimization of such devices depends on the optical thicknesses of the various layers and on the grating characteristics. For a given sample, the layer parameters are usually known as a first approximation, but a good accuracy is necessary to define the operating wavelength and the coupler characteristics. In a particular case — a InP/InGaAsP/InP sample which operates for optical switching in the transmission mode — we have first defined an optimized structure. Then, we have built an experimental set-up able to measure reflection and transmission coefficients versus polarization, wavelength and incidence angle. From transmission measurements performed with this apparatus, we have deduced both real and imaginary parts of the layers refractive indices. These calculated values allowed us to reoptimize the structure and to determine the operating wavelength. De nombreux dispositifs utilisés en photonique et optoélectronique sont constitués de structures multicouches en semi-conducteurs comportant un guide d'onde non linéaire et d'un coupleur à réseau. Leurs performances dépendent, en particulier, des épaisseurs optiques des différentes couches constituantes et des caractéristiques du réseau de diffraction. Pour un échantillon, les paramètres nominaux des différentes couches sont connus en première approximation, mais il est nécessaire de les préciser pour définir les conditions de fonctionnement et les caractéristiques optimales du coupleur. Dans un cas particulier — échantillon de InP/InGaAsP/InP qui doit fonctionner en commutateur optique par transmission — nous avons défini une structure optimale, puis nous avons mis au point un montage expérimental permettant de mesurer les coefficients de réflexion et de transmission en fonction de la polarisation, de la longueur d
NASA Astrophysics Data System (ADS)
Richard, Pierre
La presente these, qui combine des mesures de diffusion Raman, de transmission infrarouge, de conductivite hyperfrequence et d'interferometrie ultrasonore sur les composes Nd 2-xCexCuO 4, traite des defauts d'oxygene, ainsi que des proprietes optiques, electroniques et magnetiques de ces materiaux. Les resultats experimentaux obtenus sont correles avec plusieurs donnees experimentales disponibles dans la litterature. D'abord, la caracterisation des modes Raman et des niveaux d'energie de champ cristallin de l'ion Nd3+ au moyen de techniques optiques, en fonction du dopage en cerium et du contenu en oxygene, permettent de conclure a la presence de defauts lies a une non-stoechiometrie en oxygene dans ces composes. En effet, des excitations de champ cristallin assignees a des ions Nd3+ en sites irreguliers sont observees, en plus des bandes d'absorption associees aux ions Nd3+ en site regulier, dans les spectres correspondant aux multiplets 4I11/2, 4I13/2 et 4I 15/2 de l'ion Nd3+. Les resultats experimentaux indiquent que, contrairement a la croyance largement repandue, les oxygenes apicaux, bien que presents dans les echantillons dopes, ne sont pas enleves lors du processus de reduction des echantillons necessaire pour faire apparaitre la supraconductivite dans cette famille de cuprates. Au contraire, des lacunes d'oxygene, dont le type varie en fonction du dopage, sont creees lors de ce processus. En particulier, il est montre dans ce travail que la reduction des echantillons dopes de maniere optimale conduit a la creation de lacunes d'oxygene dans les plans CuO2. Les consequences de telles lacunes sont largement discutees. En outre, il est suggere que de telles lacunes sont responsables de la perte de l'ordre antiferromagnetique a longue portee des ions Cu2+. Finalement, l'interaction d'echange anisotrope Nd3+-Cu 2+ dans le compose nondope est caracterisee au moyen de la transmission infrarouge sous champ magnetique. L'eclatement des doublets de Kramers mesure
NASA Astrophysics Data System (ADS)
Delaite, R.; Aïch, Y.
1994-10-01
A theoretical analysis of quartz accelerometers is performed to determine their optimal mechanical and sensitivity performances. A general analytical model is used to investigate the parameters and their effects on the sensitivity of these sensors. The analysis of physical characteristics shows that feasibility and performances depend on three factors such as dimensions of the quartz plate, quantity of holders located at the crystal edge and location of these holders with respect to the crystal's crystallographic reference. This study is applied to various design sensors with different supporting quartz crystal. The conditions on parameters are given to achieve optimum performances. Une étude théorique de la sensibilité des capteurs d'accélération à cristal de quartz est présentée. Son but est d'optimiser les performances mécaniques et métrologiques de ces capteurs. Les paramètres sensibles sont mis en évidence. L'analyse des caractéristiques physiques démontre que la faisabilité et les performances des accéléromètres à quartz dépendent, pour une coupe donnée du cristal, de trois facteurs : les dimensions de la lame de quartz, le nombre de liaisons à la périphérie du cristal et la position de ces liaisons par rapport à la référence cristallographique. L'étude est appliquée aux cas des capteurs bipodes, multipodes et monopodes. Pour chaque type de capteur, les valeurs des paramètres sensibles correspondant aux performances optimales sont précisées.
Capteur Tridimensionnel Sans Contact
NASA Astrophysics Data System (ADS)
Magnant, D.
1986-07-01
Three-dimensionnal measurements on human body using a scanning laser beam. The active optical apparatus principle and the image data processing giving three dimensional informations of complex forms is presented. The output is given in terms of one or several files of real coordinates. The basic components of this system are : A light-sheet which is generated by a laser source and, the optical sensors (cameras) with corresponding hard-soft extractor; This 3D sensorial system is especially adapted to partial or total acquisitions of body coordinates. The main advantages are : - Vision and measurement capability of complete accessible contours without shadow areas. - The real time data acquisition and scanning of the object in a few seconds. - The access to distance measurements between significant points. - The presently obtained accuracy is better than 1/1000 in relatives units and lower than one MM absolute. - Physically stuck markers on body are not necessary. - The monochromaticity of the laser light source allows the use of a color filter over the detector (camera) for ambient light rejection. - The fully programmable capability for any use, allows the adaptation to a large variety of particular cases. - The hardware open system offers many options. - The hard-soft tool is designed for auto-calibration operation. - The system offers easy connection to a host computer or a production robot.
NASA Astrophysics Data System (ADS)
Denoyer, Aurelie
La decouverte et l'elaboration de nouveaux materiaux laser solides suscitent beaucoup d'interet parmi la communaute scientifique. En particulier les lasers dans la gamme de frequence du micron debouchent sur beaucoup d'applications, en telecommunication, en medecine, dans le domaine militaire, pour la, decoupe des metaux (lasers de puissance), en optique non lineaire (doublage de frequence, bistabilite optique). Le plus couramment utilise actuellement est le Nd:YAG dans cette famille de laser, mais des remplacants plus performants sont toujours recherches. Les lasers a base d'Yb3+ possedent beaucoup d'avantages compares aux lasers Nd3+ du fait de leur structure electronique simple et de leur deterioration moins rapide. Parmi les matrices cristallines pouvant accueillir l'ytterbium, les orthosilicates Yb:Y 2SiO5, Yb:Lu2SiO5 et Yb:Sc2SiO 5 se positionnent tres bien, du fait de leur bonne conductivite thermique et du fort eclatement de leur champ cristallin necessaire a l'elaboration de lasers quasi-3 niveaux. De plus l'etude fine et systematique des proprietes microscopiques de nouveaux materiaux s'avere toujours tres interessante du point de vue de la recherche fondamentale, c'est ainsi que de nouveaux modeles sont concus (par exemple pour le champ cristallin) ou que de nouvelles proprietes inhabituelles sont decouvertes, menant a de nouvelles applications. Ainsi d'autres materiaux dopes a l'ytterbium sont connus pour leurs proprietes de couplage electron-phonon, de couplage magnetique, d'emission cooperative ou encore de bistabilite optique, mais ces proprietes n'ont encore jamais ete mises en evidence dans Yb:Y 2SiO5, Yb:Lu2SiO5 et Yb:Sc2SiO 5. Ainsi, cette these a pour but l'etude des proprietes optiques et des interactions microscopiques dans Yb:Y2SiO 5, Yb:Lu2SiO5 et Yb:Sc2SiO5. Nous utilisons principalement les techniques d'absorption IR et de spectroscopie Raman pour determiner les excitations du champ cristallin et les modes de vibration dans le materiau
L'effet Peltier appliqué à la conception et la réalisation d'un nouveau capteur de débit massique
NASA Astrophysics Data System (ADS)
Wattiau, F.; Gaviot, E.; Thery, P.
1993-08-01
éalisation d'un nouveau capteur de débit massique basé sur l'effet Peltier. Le capteur en forme de circuit imprimé bimétallique, comporte plusieurs pistes métalliques continues parallèles entre elles et partiellement recouvertes par un grand nombre de dépôts électrolytiques de nature différente. Un tel circuit se comporte comme un circuit thermoélectrique classique dans lequel les parties homogènes non recouvertes par le dépôt électrolytique constituent le premier conducteur du couple, les parties plaquées constituant le second conducteur. La méthode de mesure consiste à faire passer un courant électrique dans une ou plusieurs pistes constituant le circuit émetteur de façon à générer par effet Peltier des gradients thermiques qui seront détectés par un circuit détecteur identique placé à proximité. Dans le cas particulier d'un fluide au repos, la f.e.m. détectée par le circuit détecteur dépend de la conductivité thermique du fluide. Lorsque le fluide est en mouvement relatif par rapport au circuit, il est possible de détecter une f.e.m. dépendant en grandeur et en signe de la vitesse d'écoulement du fluide. A titre d'application un capteur de débit massique a été réalisé en plaçant les circuits thermoélectriques dans une canalisation parcourue par le fluide en mouvement.
Microscopie interférentielle X-UV : un outil pour l'étude des endommagements des surfaces optiques
NASA Astrophysics Data System (ADS)
Jamelot, G.; Ros, D.; Cassou, K.; Kazamias, S.; Klisnick, A.; Kozlová, M.; Mocek, T.; Homer, P.; Polan, J.; Stupka, M.
2006-12-01
Nous présentons des résultats récents concernant des premières investigations de microscopie interférentielle par laser X-UV d'endommagement optique. Le laser X-UV utilisé est un laser collisionnel en régime quasi-stationnaire émettant à 21.2 nm, développé au Prague Asterix Laser System (PALS, Prague, République Tchèque). Des échantillons de silice fondue de haute qualité, avec ou sans rayure, étaient irradiées en face avant par un laser bleu, correspondant au 3selectfontfontsize{7{9}{textrm{ème}}} harmonique du laser à iode du PALS (1.315 μ m), servant également à réaliser le laser X-UV à 21.2 nm. Celui-ci était utilisé, 5 ns après l'irradiation pour réaliser une imagerie microscopique et interférentielle de la face arrière de l'échantillon. Les résultats font apparaître des déformations locales transitoires. Des premières analyses mettent en évidence une probable variation de la rugosité de la surface. Cette démonstration expérimentale encourageante ouvre la voie à de futures investigations, notamment sur notre prochaine installation laser : LASERIX.
Improved Chaff Solution Algorithm
2009-03-01
Programme de démonstration de technologies (PDT) sur l’intégration de capteurs et de systèmes d’armes embarqués (SISWS), un algorithme a été élaboré...technologies (PDT) sur l’intégration de capteurs et de systèmes d’armes embarqués (SISWS), un algorithme a été élaboré pour déterminer automatiquement...0Z4 2. SECURITY CLASSIFICATION (Overall security classification of the document including special warning terms if applicable .) UNCLASSIFIED
NASA Astrophysics Data System (ADS)
Longchambon, L.; Laurat, J.; Treps, N.; Ducci, S.; Maître, A.; Coudreau, T.; Fabre, C.
2002-06-01
Nous étudions théoriquement les propriétés quantiques des faisceaux lumineux continus orthogonalement polarisés émis par un Oscillateur Paramétrique Optique (OPO) de type II contenant une lame biréfringente. Quand les axes optiques de la lame sont tournés par rapport à ceux du cristal paramétrique, un couplage apparaît entre les faisceaux signal et complémentaire qui entraîne un verrouillage de phase entre les deux modes et un fonctionnement à dégénérescence de fréquence à l'intérieur d'une zone d'accrochage. Les corrélations quantiques entre les deux faisceaux permettent de définir les zones dans l'espace des paramètres expérimentaux où les différents critères associés à l'intrication EPR utilisés en information quantique sont vérifiés.
NASA Astrophysics Data System (ADS)
Larouche, Stephane
Optical interference filters can be found everywhere. Their applications range from antireflective coatings present on almost every optical element to narrowband filters used in telecommunication networks and in astronomy. Most optical filters consist of a stack of homogeneous layers of two or a few materials with discrete refractive indices. They are called multilayer filters. If an appropriate process is available, it is also possible to fabricate graded-index filters, in which the refractive index varies continuously. Another less explored avenue is the conception of multilayer filters, but with layer of arbitrary intermediate refractive indices. At normal incidence, it has been demonstrated the optimal filter for a given application consists of only two materials with the greatest refractive index contrast. At oblique incidence, the situation is more complex. Electric and magnetic fields continuity conditions at interfaces are different for s and p polarizations, which leads to the definition of different pseudo refractive indices. It is generally accepted that the optimal solution maximizes the pseudo refractive index contrast, and it is therefore probable that the optimal design includes intermediate refractive indices. The conception of optical filters relies on the use of design, optimization, and synthesis methods. There exist many very effective methods for the conception of multilayer filters with discrete refractive indices. However, the methods are less adapted to the conception of filters with intermediate refractive indices. Graded-index filters can be designed using the approximate Fourier transform relationship between the refractive index profile and the desired spectrum. However, this method has two important drawbacks: (1) it is only approximate and (2) it does not account for the effect of the refractive index dispersion. The former is usually addressed by an iterative approach. However, there was no general solution to the problem of the
Développement d'outils de mesure pour l'amélioration du procédé d'impression offset
NASA Astrophysics Data System (ADS)
Boumaïza, K.; Baudin, G.; Catusse, R.; Viallet, A.
1999-03-01
The offset printing process rests primarily on the balance between ink and damping solution. However, this balance remains difficult to realize. The corresponding wastes of time and into consumable (ink, paper and damping solution) are harmful for the industrialist, the consumer and the environment. The main feature of this work is to control and thus to optimize these flux. With this intention, two optical sensors functioning in reflection were developed. A laser with receiving photodiode for the control of damping solution film thickness, and an optical fiber related to a photoelectric sensor for control of ink film thickness. The current study aims at the calibration of these two sensors for respectively the control of water and ink flux in the offset press. Le procédé d'impression offset repose essentiellement sur l'équilibre entre la solution de mouillage et l'encre. Toutefois, cet équilibre reste une tâche difficile à réaliser. Les pertes en temps et en consommables (encre, papier, solution de mouillage) correspondantes sont nuisibles à la fois pour l'industriel, le consommateur et l'environnement. L'objectif de ce travail est de contrôler et donc d'optimiser ces flux pour un tirage donné. Pour ce faire, deux capteurs de type optique fonctionnant en réflexion ont été développés. Un laser avec photodiode réceptrice pour le contrôle du film de solution de mouillage, et une fibre optique liée à un capteur photoélectrique pour le contrôle du film d'encre. L'étude actuelle vise la mise en ouvre et l'étalonnage de ces deux capteurs pour la mesure et le contrôle des films respectifs d'eau et d'encre dans la presse offset.
Manipulation optique spatio-temporelle non resonnante de cristaux liquides nematiques
NASA Astrophysics Data System (ADS)
Brasselet, Etienne
Ce travail est consacre a l'etude theorique et experimentale du comportement structurel et dynamique d'un cristal liquide nematique soumis a deux faisceaux laser superposes de polarisation circulaire. Pour une intensite, une circularite et un sens de propagation quelconque de chacun des deux faisceaux, nous avons obtenu la solution analytique des deformations photoinduites dans le cas ou les deux ondes sont incoherentes. Le cas de deux ondes coherentes est aussi discute. L'arrangement moleculaire calcule est plan ou a trois dimensions, fixe ou en rotation. Nous demontrons la possibilite de manipuler a volonte les deformations tridimensionnelles ou la vitesse de rotation ainsi qu'un comportement multistable a forte intensite, ce qui est impossible avec un seul faisceau. La partie experimentale de ce travail, a necessite l'elaboration d'une technique de mesure, en temps reel, de la rotation et des deformations 3D du cristal liquide. Le controle de la rotation est demontre, lorsque les deux faisceaux portent des moments cinetiques opposes. La mesure des deformations de torsion montre qu'il est possible d'induire, au moyen de deux ondes et de maniere non resonnante, une chiralite macroscopique controlee, sans rotation. Dans le cas particulier d'une seule onde polarisee circulairement, nous avons montre que le regime dynamique induit est la combinaison d'une deformation 3D, d'une precession et d'une oscillation non amortie. A forte intensite, la transition vers un regime fortement reoriente a pu etre explique a l'aide d'un modele qualitatif prenant en consideration les fluctuations de la composante azimutale du couple dielectrique et la non localite de la reponse du cristal liquide. Finalement, la structure "multi-niveaux" des etats fortement reorientes est mise en evidence et le role des deformations a trois dimensions est discute, ce qui permet en particulier d'interpreter l'absence de multistabilite dans le cas d'une seule onde circulaire.
NASA Astrophysics Data System (ADS)
Gorju, G.; Chauve, A.; Crozatier, V.; Lorgeré, I.; Le Gouët, J.-L.; Bretenaker, F.
2006-10-01
Nos travaux s'inscrivent dans le cadre des expériences de traitement optique des signaux hyperfréquence utilisant des ions de terres rares en matrice cristalline excités par des sources lasers agiles en fréquence. Nous présentons la réalisation d'un analyseur de spectre avec une bande passante de 10 GHz et une résolution ultime en dessous du MHz.
Spectroscopie Raman et Rayleigh stimulée des mélasses optiques unidimensionnelles (partie I)
NASA Astrophysics Data System (ADS)
Courtois, Jean-Yves
stimulated Raman lines are homogeneously broadened, and that a stimulated Rayleigh structure appears on the spectra because of the probe-induced time modulation of the cooling force, which induces a modulation of the atomic momentum distribution. In the latter situation, the Raman structures are inhomogeneously broadened, and a recoil-induced resonance is predicted in the center of the spectrum. Its shape corresponds to the derivative of a Gaussian curve and its width is directly proportional to the Doppler width of the molasses. Finally, Section 6 presents a short review about the recent developments in the field of nonlinear spectroscopy of optical molasses. Cet article s'inscrit dans le double contexte de la spectroscopie non linéaire des milieux atomiques et de la physique du refroidissement d'atomes neutres par laser. Il présente une étude détaillée des spectres de transmission d'une onde sonde interagissant avec une mélasse optique unidimensionnelle. Plus précisément, nous montrons que dans chacun des deux cas modèles des mélasses “linperp lin” et “σ^+-σ^-” (ainsi dénommées par référence à la configuration de polarisation des deux faisceaux lasers à l'origine du mécanisme de refroidissement), les spectres pompes-sonde présentent des structures résonnantes pouvant s'interpréter en termes de diffusion Raman ou Rayleigh stimulée, et apportant un grand nombre d'informations sur les propriétés physiques des mélasses optiques. Cet article s'articule autour de deux grandes parties. Destinée à faire ultérieurement ressortir la spécificité des processus de diffusion stimulée se produisant dans les mélasses optiques, la première est consacrée à une présentation générale des processus Raman et Rayleigh stimulés se produisant dans les milieux atomiques et moléculaires conventionnels. L'effet Raman stimulé, lié à l'existence de centres diffuseurs ayant des états d'énergies et de populations différentes, fait l'objet du
High-End CMOS Active Pixel Sensors For Space-Borne Imaging Instruments
2005-07-13
sur la technologie CCD, alors que les capteurs CMOS à pixel actifs (APS) ont des nombreux avantages pour des applications embarquées. Cette...Les capteurs optiques intégrés sont utilisés dans le domaine spatial dans un large éventail d’applications. Beaucoup d’entres elles reposent toujours...publication présente des capteurs CMOS hautes performances d’aujourd’hui et met en lumière leurs avantages par rapport à leur équivalent CCD. Ces capteurs
NASA Astrophysics Data System (ADS)
Aliouane, T.; Bouzid, D.; Belkhir, N.; Bouzid, S.; Herold, V.
2005-05-01
La fabrication des composants en verre optique nécessite des moyens de grande précision dans les procédés de finition vue l'importance accordée à leur qualité. Durant le processus de polissage des verres optiques, le polissoir est un élément clé et a un impact direct sur les performances des composants optiques, non seulement il est utilisé comme support de grains abrasifs mais il doit posséder la fonction de transmission de la pression aux grains. La connaissance de ses propriétés, essentiellement mécanique, est impérative afin d'obtenir un état de surface optimal des composants optiques destinés à remplir des fonctions très précises dans des appareils optiques très performants. Dans cette étude, nous avons constaté que les propriétés des polissoirs en polyuréthanne tel que la dureté, le module d'élasticité et la densité varient au cours du polissage. Ce changement a des effets sur l'état de surface de verre optique, causé par le changement microstructural de la surface du polissoir (distribution et dimensions des pores) et par conséquent sur la quantité des abrasifs (en oxyde de cérium) insérée dans les pores, ce qui influe sur la quantité de verre enlevée et sur l'état de surface du composant. Sur la base des résultats obtenus, il a été prouvé que le polissoir subit des modifications très importantes ce qui influe considérablement sur son efficacité de polissage.
NASA Astrophysics Data System (ADS)
Spach, Gérard; Merle, Liliane
Since the discovery of the optical activity of the biomolecules, the early origin of the biopolymer asymmetry (Nucleic acids and proteins) of the living cells is the subject of many speculations. In some simple instances, asymmetric amplification has been shown experimentally to occur at the molecular level. Following some authors, its origins can be found at the subatomatic level. In this article, the early asymmetric enclosing of prebiotic moieties is stressed, by refering especially to the presence of chiral compounds of lipidic nature in the vesicle membranes and to ancestral pores or channels able to select optically active constituents of the "primordial soup", a few billion years ago. L'origine ancestrale de l'asymétrie des biopolymères, acides nucléiques et protéines, de la cellule vivante suscite depuis la découverte de l'activité optique des biomolécules une vive discussion et la recherche d'une explication rationnelle. Dans des cas relativement simples, une amplification certaine de l'asymétrie a été montrée expérimentalement au niveau moléculaire, et selon certains, elle pourait trouver sa source au niveau subatomique. Dans cet article, le rôle précoce du confinement asymétrique de la matière prébiotique est souligné, notamment en se référant à la présence de pores ou de cannaux capables de sélectionner des constituants optiquements actifs de la "soupe primordiale", il y a quelques milliards d'années.
NASA Astrophysics Data System (ADS)
Laurat, J.; Longchambon, L.; Coudreau, T.; Fabre, C.
2004-11-01
Les faisceaux continus orthogonalement polarisés émis par les Oscillateurs Paramétriques Optiques (OPO) de type II pompés au-dessus du seuil présentent au niveau quantique de fortes corrélations d'intensité et anti-corrélations de phase. Ils sont donc de très bons candidats pour générer des faisceaux intriqués en quadrature. Cependant, un phénomène de diffusion de phase rend difficile la mesure des propriétés sur la phase. Nous avons étudié théoriquement le régime stationnaire et les propriétés quantiques d'un OPO contenant une lame biréfringente. Le couplage linéaire qui en résulte entraîne un verrouillage en phase ainsi qu'un fonctionnement à dégénérescence en fréquence à l'intérieur d'une zone d'accrochage. L'expérience en cours au laboratoire a permis d'observer ce phénomène de verrouillage.
NASA Astrophysics Data System (ADS)
Bonnin, O.; Cahouet, J.; Giordano, P.
1993-03-01
more accurate comparison, for example on the crack depth, is difficult because of the uncertainty on the physical properties of the materials. Dans le cadre d'un projet industiel de conception et d'optimisation de capteurs pour la recherche de fissures par courants de Foucault sur les plate-formes de forage, on présente les études menées pour la modélisation du système. La simulation des phénomènes implique à priori une modélisation tridimensionnelle, certes précise, mais difficile et coûteuse. On cherche à en limiter le coût en combinant une modélisation bidimensionnelle en l'absence de défaut, et une modélisation tridimensionnelle locale en présence d'une fissure. Après avoir présenté le projet et l'étude expérimentale qui en découle, on décrit les techniques de modélisation qui ont été employées.
NASA Astrophysics Data System (ADS)
Lopez, L.; Gatti, A.; Maitre, A.; Treps, N.; Gigan, S.; Fabre, C.
2004-11-01
Nous nous intéressons au comportement spatial des fluctuations quantiques à la sortie d'un oscillateur paramétrique optique dégénéré en modes transverses, sous le seuil. En vue de futures expériences, nous étudions les effets de la diffraction dans le milieu paramétrique sur le bruit quantique spatial. Nous montrons que l'on voit apparaître une aire de cohérence de taille finie pour les effets quantiques transverses.
NASA Astrophysics Data System (ADS)
Joulain, K.; Henkel, C.; Greffet, J.-J.
2006-10-01
Nous évaluons la force de Casimir entre deux surfaces planes métalliques constituées d'argent. Nous prenons, pour effectuer cette évaluation, des propriétés optiques de l'argent à différentes températures [1]. Nous montrons que cette dépendance en température modifie la force de Casimir (de 0.2%) y compris à des distances inférieures à la longueur d'onde thermique.
Etude échographique du diamètre de l'enveloppe du nerf optique chez l'enfant noir africain sain
de Tové, Kofi-Mensa Savi; Biaou, Olivier; Adedemy, Julien Didier; Fatigba, Olatoundji Holden; Yèkpè, Patricia; Boco, Vicentia; Agossou-Voyeme, Augustin Karl
2014-01-01
Introduction L'objectif de cette étude était de déterminer le diamètre échographique de l'enveloppe du nerf optique (DENO) dans une population d'enfants sains noirs Africains au Bénin. Méthodes Une étude transversale descriptive a été menée sur une période de 6mois. Le DENO a été mesuré chez 304 enfants sains. Deux mesures échographiques du DENO (coupe transversale et sagittale) ont été réalisées 3mm en arrière de la papille sur chaque œil. Le DENO d'un patient est égal à la moyenne des quatre mesures. Résultats L’âge moyen était de 35, 72 ± 35,38 mois et la sex-ratio H/F de 0,96. La mesure moyenne du DENO était de 3, 31±0,54mm avec des extrêmes de 2,02 et de 4,44mm. Le DENO croît avec l’âge avec une moyenne corrélation significative (r = 0,58 et p < 0,0001). Cette croissance est plus marquée pendant les 48 premiers mois de vie. Il n'y avait pas de différence entre les garçons et les filles (p = 0, 45). Conclusion Les valeurs retrouvées dans cette étude ne diffèrent pas de ce qui est classiquement décrit dans les autres populations. Un DENO supérieur à 4,40 (IC 95%) doit être considéré comme anormal. PMID:25870740
2003-04-01
et spatiaux. Comparé aux autres capteurs ( optiques et infrarouges, visibles), le radar offre des performances complémentaires telles qu’un...SET-057) Synthèse La surveillance de la terre par des capteurs aéroportés et spatiaux est devenu un facteur essentiel de la guerre moderne. Des...opérations récentes (la guerre du Golfe, la Bosnie, l’Afghanistan), ont démontré l’intérêt des informations fournies par les capteurs aéroportés
NASA Astrophysics Data System (ADS)
Tcheremiskine, V. I.; Sentis, M.; Mikheev, L. D.; Clady, R.
2003-06-01
Le rayonnement UV-VUV issu d'un plasma généré par une décharge électrique de forte puissance dans un milieu gazeux (ici XeF2) est capable d'exciter de grands volumes de différents milieux lasers. Nous présentons une nouvelle source optique UV-VUV de forte puissance basée sur une décharge multi-canaux réalisée sur la surface d'un diélectrique ainsi que les premiers résultats d'amplification d'impulsions femtosecondes obtenus dans le milieu actif d'un laser photolytique XeF(C-A). Ce milieu est très attractif pour développer des systèmes lasers hybrides de forte puissance (petawatt) dans le domaine du visible. En effet, la transition XeF(C-A) est caractérisée par une bande spectrale très large dans le bleu-vert (460-520 nm) permettant d'amplifier des impulsions optiques d'une durée de l'ordre de 10 fs.
NASA Astrophysics Data System (ADS)
Foucher, Samuel
'energie locale des coefficients d'ondelettes comme degre de fiabilite. L'information ainsi fusionnee est ensuite utilisee comme champ de Markov "evidentiel" dans un algorithme de relaxation stochastique (MPM). L'in-tegration de l'information multiechelle ameliore les resultats de l'algorithme MPM. La methode proposee est ensuite etendue a un domaine multisource ou l'image radar, plus incertaine, est integree a la classification de l'image optique via un champ de Markov "evidentiel" multiechelle.
In-situ Detection of Contaminant Plumes in Ground Water
1990-08-01
Dao, M. Jouan, H. Feurier and H. tation, Los Angeles, in press. Saisse (1986) Simulation et optimisation des capteurs A Weyer, L.G., K.J. Becker and...H.B. Leach.(1987) fibres optiques adjacentes. Applied Optics, 25: Remote sensing fiber optic probe NIR spectroscopy 3448-3454. coupled with
In-Situ Detection of Contaminant Plumes in Ground Water
1990-08-01
direct forms of spectroscopy that can pleniented through optical fiber (Foulk and Gaz -gus be implemented through fiber opt"s. Fluorescence 1987. Weyer...Anaeles. in press, Saisse 1, 986) Simnulation etoptimisation des capteurs i Weyer, L.G., K.J. Becker and H.B. Leach (1987) fibres optiques adjacentes
NASA Astrophysics Data System (ADS)
Rioux, David
several times, tabular data are often limited to a few specific compositions and an analytical model would be more interesting. This thesis focuses on the study and modeling of the optical properties of gold-silver alloy NPs, on their synthesis as well as an application example; using these NPs as cell markers for multiplexed scattering imaging. The first part of this thesis deals with a study of the dielectric function of gold-silver alloys in order to develop an analytical model to calculate the dielectric function for an arbitrary composition of the alloy. This model considers the contribution of the free and bound electrons of the metal to the dielectric function. The contribution of free electrons is calculated using the Drude model while the contribution of bound electrons was modeled by studying the shape of the interband transitions from the study of the gold and silver band structures. A parameterized model incorporating these two contributions was developed and composition dependence comes from the evolution of these parameters depending on the composition. The model was validated by comparing the spectra of experimental extinctions alloy NPs with the spectra calculated by the Mie theory using the dielectric functions determined from this model. This model has also been very useful to predict the optical properties and characterize NPs produced by a new synthesis method developed during this PhD project. This method allowed the synthesis of spherical gold-silver alloy NPs with controlled size and composition while maintaining a small size distribution. This technique relies on the combination of two known methods. The first, being used for the synthesis of small alloy NPs, is based on the chemical co-reduction of gold and silver salts in aqueous solution. The second, used for the synthesis of gold or silver NPs of controlled size, is the seed-mediated growth method. Using this new approach, the synthesis sized gold-silver alloy NPs with sizes controlled between
NASA Astrophysics Data System (ADS)
Tiburcio-Silver, A.; Joubert, J. C.; Labeau, M.
1992-07-01
Undoped and indium-doped ZnO thin films deposited by the Pyrosol process onto soda-lime glass substrates were electrically and optically characterized. Resistivities as low as 2× 10^{-3} Ω.cm. Hall mobilities as high as 21 cm^2 V^{-1} s^{-1} and effective carrier concentrations as high as 1 × 10^{20} cm^{-3} have been obtained. Electron concentrations are always lower than indium contents on the films. Average optical transmissions on the whole visible range as high as 85% for the best conductive films have been obtained. Refractive index of layers is modified by the growth temperature and indium doping, been less dependent on doping for high deposition temperatures (better crystallinity). Haacke's figure of merit up to 5× 10^{-3} Ω^{-1} in a 500 nm thick films were obtained. Indium doping improves the time-dependent stability of the electrical properties of ZnO conducting films. Des couches minces de ZnO conducteur non dopé et dopé à l'indium, élaborées par le procédé Pyrosol sur des substrats en verre sodocalcique, ont été caractérisées du point de vue électrique et optique. Résistivités de 2× 10^{-3} Ω.cm, mobilités Hall de 21 cm^2 V^{-1} s^{-1}, et concentrations effectives des porteurs de l'ordre de 1 × 10^{20} cm^{-3} ont été obtenues. La concentration des porteurs mesurée par effet Hall est toujours inférieure à la concentration d'indium dans la couche. La transmission optique moyenne dans le visible atteint 85 % pour les films possédant la meilleure conductivité. La température de dépôt et le dopage à l'indium modifient l'indice de réfraction ; celui-ci dépend moins du dopage à des températures de dépôt élevées (meilleure cristallinité). Les meilleurs facteurs de mérite, \\varnothing_TC, sont de l'ordre de 5× 10^{-3} Ω^{-1} (épaisseur du film 5 000 Å environ). Le dopage à l'indium améliore la stabilité dans le temps des propriétés électriques des couches de ZnO.
2008-10-01
Ramin Sabry Ramin Sabry Defence Scientist Approved by Original signed by Paris Vachon Paris Vachon A/Head, Radar Applications and Space Technologies...En se basant sur ce qui précède, on étudie les caractéristiques communes, l’interfonctionnement et la fusion de divers produits de capteurs ...polarimétriques dans diverses régions du spectre, p. ex. le radar classique ou le radar à synthèse d’ouverture et des capteurs électro-optiques, et on formule
Bullock, Jonathan S.; Harper, William L.; Peck, Charles G.
1976-06-22
This invention is directed to an aqueous halogen-free electromarking solution which possesses the capacity for marking a broad spectrum of metals and alloys selected from different classes. The aqueous solution comprises basically the nitrate salt of an amphoteric metal, a chelating agent, and a corrosion-inhibiting agent.
NASA Astrophysics Data System (ADS)
Hernandez, D.; Ciaurriz, C.; Olalde, G.
1991-09-01
A device and a direct method for measuring directional emissivity within a spectral bandpass Δλ are presented. The method applies to opaque and diffuse surfaces at high temperatures. When the selected spectral bandpass is large, the measured emissivity gets closer to the total one and conversely, it tends to approach the spectral one when a pseudo-monochromatic bandpass is chosen. Radiances are on one hand experimentally measured with a radiometer and on the other hand calculated from the sample temperature. The original point of the method lies in the sample temperature measurement, which is performed with a photonic two-colour pyrometer. The pyrometer probe consists of a unique SiO2/SiO2 optical fibre associated with a reflecting hemisphere. The samples are heated with concentrated solar radiation. Nous présentons un dispositif et une méthode directe adaptée à la mesure de l'émissivité directionnelle dans une bande spectrale Δλ, pour des corps opaques et diffusants à haute température. La bande spectrale peut être sélectionnée pour un large domaine, l'émissivité mesurée se rapproche alors de l'émissivité totale ou bien sur un domaine pseudo-monochromatique, l'émissivité correspond dans ce cas à une émissivité spectrale. Les flux radiatifs sont déterminés expérimentalement par un radiomètre et calculés à partir de la mesure de la température de l'échantillon. La mesure de la température, point original de la méthodologie, est réalisée à l'aide d'un pyromètre photonique bicolore muni d'une sonde à fibre optique toute silice associée à un hémisphère réflecteur. Les échantillons sont chauffés par rayonnement solaire concentré.
Advanced Technology for SAM Systems Analysis Synthesis and Simulation
1984-05-01
naltre, de se d~velooper, de se n~rimer, souvent de renaltre :en matit’re de Capteurs d’informations, le radar et lea proctd~s 6lectro- optiques ont...pbles d~i d~nominateur. 5-4S La riponse naturelle du missile i un ordre de pilotage est de ce fait fid~le, rapide et peu affect~e per 1 ’oscillation
Seitz, M.G.
1982-01-01
Reviewed in this statement are methods of preparing solutions to be used in laboratory experiments to examine technical issues related to the safe disposal of nuclear waste from power generation. Each approach currently used to prepare solutions has advantages and any one approach may be preferred over the others in particular situations, depending upon the goals of the experimental program. These advantages are highlighted herein for three approaches to solution preparation that are currently used most in studies of nuclear waste disposal. Discussion of the disadvantages of each approach is presented to help a user select a preparation method for his particular studies. Also presented in this statement are general observations regarding solution preparation. These observations are used as examples of the types of concerns that need to be addressed regarding solution preparation. As shown by these examples, prior to experimentation or chemical analyses, laboratory techniques based on scientific knowledge of solutions can be applied to solutions, often resulting in great improvement in the usefulness of results.
NASA Astrophysics Data System (ADS)
Lee, Go-Eun; Kim, Il-Ho; Lim, Young Soo; Seo, Won-Seon; Choi, Byeong-Jun; Hwang, Chang-Won
2014-06-01
Since Bi2Te3 and Bi2Se3 have the same crystal structure, they form a homogeneous solid solution. Therefore, the thermal conductivity of the solid solution can be reduced by phonon scattering. The thermoelectric figure of merit can be improved by controlling the carrier concentration through doping. In this study, Bi2Te2.85Se0.15:D m (D: dopants such as I, Cu, Ag, Ni, Zn) solid solutions were prepared by encapsulated melting and hot pressing. All specimens exhibited n-type conduction in the measured temperature range (323 K to 523 K), and their electrical conductivities decreased slightly with increasing temperature. The undoped solid solution showed a carrier concentration of 7.37 × 1019 cm-3, power factor of 2.1 mW m-1 K-1, and figure of merit of 0.56 at 323 K. The figure of merit ( ZT) was improved due to the increased power factor by I, Cu, and Ag dopings, and maximum ZT values were obtained as 0.76 at 323 K for Bi2Te2.85Se0.15:Cu0.01 and 0.90 at 423 K for Bi2Te2.85Se0.15:I0.005. However, the thermoelectric properties of Ni- and Zn-doped solid solutions were not enhanced.
NASA Astrophysics Data System (ADS)
Colby, Ralph H.
2008-03-01
Pierre-Gilles de Gennes once described polyelectrolytes as the ``least understood form of condensed matter''. In this talk, I will describe the state of the polyelectrolyte field before and after de Gennes' seminal contributions published 1976-1980. De Gennes clearly explained why electrostatic interactions only stretch the polyelectrolyte chains on intermediate scales in semidilute solution (between the electrostatic blob size and the correlation length) and why the scattering function has a peak corresponding to the correlation length (the distance to the next chain). Despite many other ideas being suggested since then, the simple de Gennes scaling picture of polyelectrolyte conformation in solution has stood the test of time. How that model is used today, including consequences for dynamics in polyelectrolyte solutions, and what questions remain, will clarify the importance of de Gennes' ideas.
Krawczyk, Gerhard Erich; Miller, Kevin Michael
2011-07-26
There is provided a method of making a polymer solution comprising polymerizing one or more monomer in a solvent, wherein said monomer comprises one or more ethylenically unsaturated monomer that is a multi-functional Michael donor, and wherein said solvent comprises 40% or more by weight, based on the weight of said solvent, one or more multi-functional Michael donor.
NASA Astrophysics Data System (ADS)
Eliyan, Faysal Fayez; Alfantazi, Akram
2014-11-01
This paper presents an electrochemical study on the corrosion behavior of API-X100 steel, heat-treated to have microstructures similar to those of the heat-affected zones (HAZs) of pipeline welding, in bicarbonate-CO2 saturated solutions. The corrosion reactions, onto the surface and through the passive films, are simulated by cyclic voltammetry. The interrelation between bicarbonate concentration and CO2 hydration is analyzed during the filming process at the open-circuit potentials. In dilute bicarbonate solutions, H2CO3 drives more dominantly the cathodic reduction and the passive films form slowly. In the concentrated solutions, bicarbonate catalyzes both the anodic and cathodic reactions, only initially, after which it drives a fast-forming thick passivation that inhibits the underlying dissolution and impedes the cathodic reduction. The significance of the substrate is as critical as that of passivation in controlling the course of the corrosion reactions in the dilute solutions. For fast-cooled (heat treatment) HAZs, its metallurgical significance becomes more comparable to that of slower-cooled HAZs as the bicarbonate concentration is higher.
ERIC Educational Resources Information Center
Starkman, Neal
2007-01-01
Poor classroom acoustics are impairing students' hearing and their ability to learn. However, technology has come up with a solution: tools that focus voices in a way that minimizes intrusive ambient noise and gets to the intended receiver--not merely amplifying the sound, but also clarifying and directing it. One provider of classroom audio…
ERIC Educational Resources Information Center
Starkman, Neal
2007-01-01
Poor classroom acoustics are impairing students' hearing and their ability to learn. However, technology has come up with a solution: tools that focus voices in a way that minimizes intrusive ambient noise and gets to the intended receiver--not merely amplifying the sound, but also clarifying and directing it. One provider of classroom audio…
Teacher's Professional Development from Vygotskian Optique
ERIC Educational Resources Information Center
Shabani, Karim
2012-01-01
Vygotsky's concept of ZPD (Zone of Proximal Development) has been recently applied to the context of language teacher education by a number of researchers (e.g. Ohta, 2005; Singh & Richards, 2006; Nassaji & Cumming, 2000). Besides Vygotsky's notion of ZPD, this paper relies on two associated theories from outside the TESOL discipline…
NASA Astrophysics Data System (ADS)
Benfedda, M.; Lahimer, S.; Bonnafe, J.
1998-11-01
The photon scanning tunneling microscopy (PSTM) allows to characterize the surface topography with high resolution. This microscopy exploits the exponential decay of the evanescent field achieved by the total internal reflection under the surface sample. When the distance between the sensor and the surface becomes small (sim 100 nm), the non propagating photons of the evanescent field can be converted into guided propagating mode of polaritons. A bulk Silicon probe is used in the AFM experiment as a sensor of van der Waals forces. The aim of this paper is to discuss the influence of the atmospheric humidity on the PSTM measurements. We have showed that the theoretical predictions of the dielectrical capture model (DCM) are very different from the experimental results when the humidity level is higher than a threshold value (30%). We present the results obtained with TE polarization, but the same behaviour is found with TM polarization. Although, in this paper we do not propose a theoretical model explaining the deviations between DCM values and experimental, however we found a validity threshold for our experimental results and we have emited the assumption that under high humidity level the pollution film presents on the sample surface slide during the displacement of the probe. La microscopie optique à effet tunnel (PSTM) est un outil de caractérisation de surface à haute résolution. Ce microscope exploite la décroissance du champ évanescent créé sur la surface de l'échantillon. Quand la distance entre le capteur et la surface est de quelques dizaines de nanomètres, les ondes évanescentes créées sur la surface sont converties en ondes propagatives et détectées en champ lointain. Le capteur est une sonde en silicium utilisée en microscopie à force atomique. Cet article montre l'influence des conditions atmosphériques sur les mesures PSTM. Il montre qu'au-delà d'un certain taux d'humidité (30%), les mesures ne sont plus valables et ne suivent
Improvement of the Spatial Amplitude Isotropy of a ^4He Magnetometer Using a Modulated Pumping Beam
NASA Astrophysics Data System (ADS)
Chéron, B.; Gilles, H.; Hamel, J.; Moreau, O.; Noël, E.
1997-08-01
Optically pumped magnetometers are scalar magnetometers. Contrary to vectoriel magnetometers, they measure the total magnetic field whatever the direction of the sensor. However, for some orientations of the magnetometer with respect to the magnetic field direction, the resonant signal vanishes and the measurement is impossible. In this paper we present a simple solution to reduce the amplitude spatial anisotropy and apply it to a ^4He magnetometer developed in our Laboratory. Les magnétomètres à pompage optique sont des magnétomètres scalaires. Contrairement aux magnétomètres vectoriels, ils mesurent le module du champ magnétique quelle que soit l'orientation du capteur dans l'espace. Cependant, pour certaines orientations du magnétomètre par rapport à la direction du champ à mesurer, l'amplitude du signal de résonance s'annule et la mesure devient impossible. Dans cet article, nous présentons une solution simple pour réduire l'anisotropie spatiale d'amplitude et nous l'appliquons à un magnétomètre à hélium-4 développé dans notre Laboratoire.
Alloy solution hardening with solute pairs
Mitchell, John W.
1976-08-24
Solution hardened alloys are formed by using at least two solutes which form associated solute pairs in the solvent metal lattice. Copper containing equal atomic percentages of aluminum and palladium is an example.
NASA Astrophysics Data System (ADS)
Morris, Simon Conway
2004-11-01
Life's Solution builds a persuasive case for the predictability of evolutionary outcomes. The case rests on a remarkable compilation of examples of convergent evolution, in which two or more lineages have independently evolved similar structures and functions. The examples range from the aerodynamics of hovering moths and hummingbirds to the use of silk by spiders and some insects to capture prey. Going against the grain of Darwinian orthodoxy, this book is a must read for anyone grappling with the meaning of evolution and our place in the Universe. Simon Conway Morris is the Ad Hominen Professor in the Earth Science Department at the University of Cambridge and a Fellow of St. John's College and the Royal Society. His research focuses on the study of constraints on evolution, and the historical processes that lead to the emergence of complexity, especially with respect to the construction of the major animal body parts in the Cambrian explosion. Previous books include The Crucible of Creation (Getty Center for Education in the Arts, 1999) and co-author of Solnhofen (Cambridge, 1990). Hb ISBN (2003) 0-521-82704-3
NASA Astrophysics Data System (ADS)
Morris, Simon Conway
2003-09-01
Life's Solution builds a persuasive case for the predictability of evolutionary outcomes. The case rests on a remarkable compilation of examples of convergent evolution, in which two or more lineages have independently evolved similar structures and functions. The examples range from the aerodynamics of hovering moths and hummingbirds to the use of silk by spiders and some insects to capture prey. Going against the grain of Darwinian orthodoxy, this book is a must read for anyone grappling with the meaning of evolution and our place in the Universe. Simon Conway Morris is the Ad Hominen Professor in the Earth Science Department at the University of Cambridge and a Fellow of St. John's College and the Royal Society. His research focuses on the study of constraints on evolution, and the historical processes that lead to the emergence of complexity, especially with respect to the construction of the major animal body parts in the Cambrian explosion. Previous books include The Crucible of Creation (Getty Center for Education in the Arts, 1999) and co-author of Solnhofen (Cambridge, 1990). Hb ISBN (2003) 0-521-82704-3
Thermodynamics of Dilute Solutions.
ERIC Educational Resources Information Center
Jancso, Gabor; Fenby, David V.
1983-01-01
Discusses principles and definitions related to the thermodynamics of dilute solutions. Topics considered include dilute solution, Gibbs-Duhem equation, reference systems (pure gases and gaseous mixtures, liquid mixtures, dilute solutions), real dilute solutions (focusing on solute and solvent), terminology, standard states, and reference systems.…
2008-04-01
exceptionnelles qui ne sont pas facilement observables dans les matériaux naturels . La plupart des recherches sur les méta-matériaux ont été consacrées à...matériaux naturels ) est une des principales raisons qui a poussé les chercheurs à approfondir leurs études sur les méta-matériaux. Avec un index...rapports signal/bruit plus importants, une vitesse plus élevée, une taille réduite, et une gamme plus large pour les systèmes de capteurs optiques
Solute atmospheres at dislocations
Hirth, John P.; Barnett, David M.; Hoagland, Richard G.
2017-06-01
In this study, a two-dimensional plane strain elastic solution is determined for the Cottrell solute atmosphere around an edge dislocation in an infinitely long cylinder of finite radius (the matrix), in which rows of solutes are represented by cylindrical rods with in-plane hydrostatic misfit (axial misfit is also considered). The periphery of the matrix is traction-free, thus introducing an image solute field which generates a solute-solute interaction energy that has not been considered previously. The relevant energy for the field of any distribution of solutes coexistent with a single edge dislocation along the (matrix) cylinder axis is determined, and coherencymore » effects are discussed and studied. Monte Carlo simulations accounting for all pertinent interactions over a range of temperatures are found to yield solute distributions different from classical results, namely, (1) Fermi-Dirac condensations at low temperatures at the free surface, (2) the majority of the atmosphere lying within an unexpectedly large non-linear interaction region near the dislocation core, and (3) temperature-dependent asymmetrical solute arrangements that promote bending. The solute distributions at intermediate temperatures show a 1/r dependence in agreement with previous linearized approximations. With a standard state of solute corresponding to a mean concentration, c0, the relevant interaction energy expression presented in this work is valid when extended to large concentrations for which Henry's Law and Vegard's Law do not apply.« less
NASA Astrophysics Data System (ADS)
Jerisian, R.; Gautron, J.; Loup, J. P.
1992-04-01
mesurée, en régime stationnaire, en fonction du débit des gaz ; ces atmosphères sont d'autant plus éloignées de l'équilibre que le débit est élevé. On montre que les variations de résistance des échantillons, en fonction du débit, dépendent du domaine de pression partielle d'oxygène, de la température et de la structure des échantillons. La sensibilité à l'oxygène est accrue par un morphologie qui, à l'échelle macroscopique, favorise la diffusion de l'oxygène et qui, à l'échelle microscopique, permet la création de barrière de potentiel aux joints de grains. En milieu oxydant, à 870 K, un mécanisme de volume qui met en jeu la cinétique des échanges avec la phase gazeuse, détermine une variation de résistance en P_{O_2}^{1/4}/P_{CO}^{1/2}. En milieu réducteur, à la même température, la non-stœchiométrie en volume de l'oxyde est fixée par le couple redox CO/CO2 comme si l'atmosphère était en équilibre thermodynamique. Mais l'abondance des électrons de conduction, favorise la chimisorption de l'oxygène qui contrôle la résistance des couches selon une loi en P_{O_2}^{1/2} en créant des barrières de potentiel à la surface des grains. Des modèles, permettant le calcul du potentiel de surface ainsi que du taux de recouvrement, sont développés ; la comparaison des modèles indique une diffusion relativement lente des lacunes d'oxygène à 870 K. A 1 100 K, l'atmosphère tend à être à l'équilibre thermodynamique : i) en atmosphère oxydante, tous les capteurs sont en équilibre avec la pression partielle d'oxygène ; ii) en atmosphère réductrice, dominée par le couple redox CO/CO2, seules les couches sont sensibles à la présence de traces d'oxygène.
Roussillon, Yann; Scholz, Jeremy H; Shelton, Addison; Green, Geoff T; Utthachoo, Piyaphant
2014-01-21
Methods and devices are provided for improved deposition systems. In one embodiment of the present invention, a deposition system is provided for use with a solution and a substrate. The system comprises of a solution deposition apparatus; at least one heating chamber, at least one assembly for holding a solution over the substrate; and a substrate curling apparatus for curling at least one edge of the substrate to define a zone capable of containing a volume of the solution over the substrate. In another embodiment of the present invention, a deposition system for use with a substrate, the system comprising a solution deposition apparatus; at heating chamber; and at least assembly for holding solution over the substrate to allow for a depth of at least about 0.5 microns to 10 mm.
Magno, Scott; Wang, Ruiping; Derouane, Eric
2003-01-01
The present invention is a mixed oxide solid solution containing a tetravalent and a pentavalent cation that can be used as a support for a metal combustion catalyst. The invention is furthermore a combustion catalyst containing the mixed oxide solid solution and a method of making the mixed oxide solid solution. The tetravalent cation is zirconium(+4), hafnium(+4) or thorium(+4). In one embodiment, the pentavalent cation is tantalum(+5), niobium(+5) or bismuth(+5). Mixed oxide solid solutions of the present invention exhibit enhanced thermal stability, maintaining relatively high surface areas at high temperatures in the presence of water vapor.
ERIC Educational Resources Information Center
Grabinger, R. Scott
1989-01-01
Discussion of the preparation of knowledge for problems appropriate for expert systems focuses on relationships among problem attributes and their solutions through the creation of a solution matrix. Two examples are given, one for wine selection and one for decisions that an automobile manufacturer's sales force might have to make. (LRW)
Cromolyn Sodium Nasal Solution
Cromolyn comes as a solution to use with a special nasal applicator. It usually is inhaled three to six times a day to prevent allergy ... first time, read the instructions provided with the solution. Ask your doctor, pharmacist, or respiratory therapist to ...
Neace, James C.
1986-01-01
Process for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 volume percent of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.
NASA Astrophysics Data System (ADS)
Bena, Iosif; Bossard, Guillaume; Katmadas, Stefanos; Turton, David
2017-01-01
We introduce a solvable system of equations that describes non-extremal multicenter solutions to six-dimensional ungauged supergravity coupled to tensor multiplets. The system involves a set of functions on a three-dimensional base metric. We obtain a family of non-extremal axisymmetric solutions that generalize the known multicenter extremal solutions, using a particular base metric that introduces a bolt. We analyze the conditions for regularity, and in doing so we show that this family does not include solutions that contain an extremal black hole and a smooth bolt. We determine the constraints that are necessary to obtain smooth horizonless solutions involving a bolt and an arbitrary number of Gibbons-Hawking centers.
Neace, J.C.
1984-03-13
A process is claimed for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 vol % of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.
Conduction heat transfer solutions
VanSant, James H.
1980-03-01
This text is a collection of solutions to a variety of heat conduction problems found in numerous publications, such as textbooks, handbooks, journals, reports, etc. Its purpose is to assemble these solutions into one source that can facilitate the search for a particular problem solution. Generally, it is intended to be a handbook on the subject of heat conduction. This material is useful for engineers, scientists, technologists, and designers of all disciplines, particularly those who design thermal systems or estimate temperatures and heat transfer rates in structures. More than 500 problem solutions and relevant data are tabulated for easy retrieval. There are twelve sections of solutions which correspond with the class of problems found in each. Geometry, state, boundary conditions, and other categories are used to classify the problems. A case number is assigned to each problem for cross-referencing, and also for future reference. Each problem is concisely described by geometry and condition statements, and many times a descriptive sketch is also included. At least one source reference is given so that the user can review the methods used to derive the solutions. Problem solutions are given in the form of equations, graphs, and tables of data, all of which are also identified by problem case numbers and source references.
NASA Astrophysics Data System (ADS)
Bolmatov, Dima; Bastrukov, S.; Lai, P.-Y.; Molodtsova, I.
2014-07-01
A fundamental task of statistical physics is to predict the system's statistical properties and compare them with observable data. We formulate the theory of dipolaron solutions and analyze the screening effects for permanent and field-induced dipolarons. The mathematical treatment of the collective behavior and microscopical morphology of dipolaron solutions are discussed. The presented computations show that the electric field shielding of dipolarons in dielectric nanosolutions is quite different from that of counterionic nano-complexes of Debye-Hückel theory of electrolytes. The limiting case of screening length λ=0 in dipolaron solutions corresponds to Coulomb's law for the potential and field of uniformly charged sphere.
NASA Astrophysics Data System (ADS)
Lion, Thomas W.; Allen, Rosalind J.
2014-05-01
Despite much current interest in active matter, little is known about osmosis in active systems. Using molecular dynamics simulations, we investigate how active solutes perturb osmotic steady states. We find that solute activity increases the osmotic pressure, and can also expel solvent from the solution —i.e. cause reverse osmosis. The latter effect cannot be described by an effective temperature, but can be reproduced by mapping the active solution onto a passive one with the same degree of local structuring as the passive solvent component. Our results provide a basic framework for understanding active osmosis, and suggest that activity-induced structuring of the passive component may play a key role in the physics of active-passive mixtures.
The Conductivity of Solutions.
ERIC Educational Resources Information Center
Rayner-Canham, Geoff
1993-01-01
Presents historical background and modern explanations for the popular demonstration of showing conductivity of solutions through the insertion of a light-bulb conductivity tester into deionized water and water with salt in it. (PR)
The Conductivity of Solutions.
ERIC Educational Resources Information Center
Rayner-Canham, Geoff
1993-01-01
Presents historical background and modern explanations for the popular demonstration of showing conductivity of solutions through the insertion of a light-bulb conductivity tester into deionized water and water with salt in it. (PR)
Isospinning baby Skyrmion solutions
NASA Astrophysics Data System (ADS)
Battye, Richard A.; Haberichter, Mareike
2013-12-01
We perform full two-dimensional (2D) numerical relaxations of isospinning soliton solutions in the baby Skyrme model in which the global O(3) symmetry is broken by the 2D analogue of the pion mass term in the Skyrme model. In our calculations we explicitly allow the isospinning solitons to deform and to break the symmetries of the static configurations. We find that stable isospinning baby Skyrme solutions can be constructed numerically for all angular frequencies ω≤min(μ,1), where μ is the mass parameter of the model. Stable, rotationally symmetric baby Skyrmion solutions for higher angular velocities are simply an artefact of the hedgehog approximation. Isospinning multisoliton solutions of topological charge B turn out to be unstable to break up into their B charge-1 constituents at some critical breakup frequency value. Furthermore, we find that for μ sufficiently large the rotational symmetry of charge-2 baby Skyrmions becomes broken at a critical angular frequency ω.
Technical product bulletin: aka OIL SOLUTIONS POWDER, SPILL GREEN LS, this miscellaneous oil spill control agent used in cleanups initially behaves like a synthetic sorbent, then as a solidifier as the molecular microencapsulating process occurs.
Gault, M. H.
1973-01-01
Certain preventable complications in the treatment of renal failure, in part related to the composition of commercially prepared peritoneal dialysis solutions, continue to occur. Solutions are advocated which would contain sodium 132, calcium 3.5, magnesium 1.5, chloride 102 and lactate or acetate 35 mEq./1., and dextrose 1.5% or about 4.25%. Elimination of 7% dextrose solutions and a reduction of the sodium and lactate concentrations should reduce complications due to hypovolemia, hyperglycemia, hypernatremia and alkalosis. Reduction in the number of solutions should simplify the procedure and perhaps reduce costs. It is anticipated that some of the changes discussed will soon be introduced by industry. PMID:4691094
Piezoelectric Energy Harvesting Solutions
Caliò, Renato; Rongala, Udaya Bhaskar; Camboni, Domenico; Milazzo, Mario; Stefanini, Cesare; de Petris, Gianluca; Oddo, Calogero Maria
2014-01-01
This paper reviews the state of the art in piezoelectric energy harvesting. It presents the basics of piezoelectricity and discusses materials choice. The work places emphasis on material operating modes and device configurations, from resonant to non-resonant devices and also to rotational solutions. The reviewed literature is compared based on power density and bandwidth. Lastly, the question of power conversion is addressed by reviewing various circuit solutions. PMID:24618725
Reflectance of aqueous solutions
NASA Technical Reports Server (NTRS)
Querry, M. R.
1972-01-01
The optical properties and optical constants of water and aqueous solutions were studied to develop an accurate tabulation of graphical representations of the optical constants through a broad spectrum. Manuscripts of articles are presented concerning extinction coefficients, relative specular reflectance, and temperature effect on the water spectrum. Graphs of absolute reflectance, phase shifts, index of refraction, and extinction coefficients for water, heavy water and aqueous solutions are included.
Conduction heat transfer solutions
VanSant, J.H.
1983-08-01
This text is a collection of solutions to a variety of heat conduction problems found in numerous publications, such as textbooks, handbooks, journals, reports, etc. Its purpose is to assemble these solutions into one source that can facilitate the search for a particular problem solution. Generally, it is intended to be a handbook on the subject of heat conduction. There are twelve sections of solutions which correspond with the class of problems found in each. Geometry, state, boundary conditions, and other categories are used to classify the problems. Each problem is concisely described by geometry and condition statements, and many times a descriptive sketch is also included. The introduction presents a synopsis on the theory, differential equations, and boundary conditions for conduction heat transfer. Some discussion is given on the use and interpretation of solutions. Supplementary data such as mathematical functions, convection correlations, and thermal properties are included for aiding the user in computing numerical values from the solutions. 155 figs., 92 refs., 9 tabs.
Optics Microwave Interactions (Interactions entre optique et micro-ondes)
2003-04-01
semiconductor laser with optical power of only a few mW is used as a source. Monolithically integrated EA modulator with sampled grating DBR laser...bandwidth and monolithic integration with other components such as laser diodes. In Fig. 4 an EAM is sketched which has been designed for a wavelength of...operating at S-band is rendered in Table II, where the best performance is achieved. For DFB laser monolithically integrated with EA modulator. The
Current Research In The Institut D'optique - Orsay
NASA Astrophysics Data System (ADS)
Marechal, A.
1985-01-01
I - FUNDAMENTAL PROBLEMS A. ASPECT : Non locality in wave mechanics. The Einstein-Bohr dispute and the optical test of Bell's inequalities. A. Einstein and N. Bohr had a discussion about the role of probabilities in microphysics; as is well known the location and momentum of particles cannot be known precisely but only through probabilistic expressions. Einstein thought that complementary variables (hidden variables) are unknown at the present time and that the knowledge of those variables would suppress the actual uncertainty "God does not play random games". On the contrary, Bohr advocated the fundamental role of probabilities. During the sixties J. Bell established inequalities supporting the Einstein point of view. These inequalities are in contradiction with the predictions of quantum mechanics in some very rare situations. A.Aspect designed and realised an optical experiment where the correlation of polarisation of photons emitted by a single atom was measured with a very good signal to noise ratio. Moreover the orientation of the polarisation analyser was changed during the time of flight of photons. The experimental result is in full agreement with the point of view of N. Bohr : the uncertainty on the movement of particles is a fundamental component of the laws of nature and Bell's inequalities do not hold.
Le pompage optique naturel dans le milieu astrophysique
NASA Astrophysics Data System (ADS)
Pecker, J.-C.
The title of this lecture abstracts only a part of it : the importance in astrophysics of the study of non-LTE situations has become considerable, as well in the stellar atmospheres as, still more, in the study of fortuitous coincidences as a mechanism of formation of emission line nebular spectra, or of molecular interstellar « masers ». Another part of this talk underlines the role of Kastler in his time, and describes his warm personality through his public reactions in front of the nuclear armement, of the Viet-Nam and Algerian wars, of the problems of political refugees... Kastler was a great scientist ; he was also a courageous humanist. 1976 : Les accords nucléaires du Brésil : allocution d'ouverture (19 mars). Colloque sur le sujet ci-dessus. 1976 : La promotion de la culture dans le nouvel ordre économique international, allocution à l'occasion d'une table ronde sur ce thème par l'UNESCO (23-27 juin 1976) ; « Sciences et Techniques », octobre 1976. 1979 : La bête immonde (avec J.-C. Pecker), « Le Matin », 20 mars. 1979 : Appel à nos ministres (avec J.-C. Pecker), « Le Monde », 13 décembre. 1979 : Le flou, le ténébreux, l'irrationnel (avec J.-C. Pecker), « Le Monde », 14 septembre. 1980 : Education à la paix, Préface, in : Publ. UNESCO. 1981 : Le vrai danger, « Le Monde », 6 août 1981. 1982 : Nucléaire civil et militaire, « Le Monde », 1er juin 1982. 1982 : Les scientifiques face à la perspective d'holocauste nucléaire (texte inédit). Le titre de cette communication en résume seulement une partie : l'importance prise en astrophysique par l'analyse des situations hors ETL est devenue considérable, qu'il s'agisse des atmosphères stellaires, ou plus encore, des coïncidences fortuites de la formation des spectres d'émission nébulaires, ou des « masers » moléculaires interstellaires. Une autre partie de cet exposé souligne le rôle de Kastler dans son époque, et décrit sa personnalité généreuse à travers ses réactions publiques face à l'armement nucléaire, aux guerres de Viet-Nam et d'Algérie, aux problèmes des réfugiés politiques... Kastler était un grand savant, mais aussi un homme courageux.
Controle des proprietes des couches optiques par bombardement ionique
NASA Astrophysics Data System (ADS)
Marushka, Viktor
The manufacture of optical coatings presents many challenges such as the control over the film properties and microstructure, the optimization for the production of thin films with high quality, and the research on new materials. Ion-assisted evaporation is one of the principal methods used for the fabrication of optical coatings as a response to these challenges. It allows for good process control, and it permits us to predict and put on an industrial scale the deposition process by considering the direct and quantitative relation between the energies of the incident ions, and the performance of the deposited materials. This work is devoted to the study of the effect of ion bombardment on the microstructure and properties of optical thin films of silicon dioxide and titanium dioxide, which are widely used in optical interference filters, in particular with the use of a Hall effect ion source. These studies include a systematic evaluation of the mechanical and optical properties and of the density of thin films using different complementary techniques - the Quartz Crystal Microbalance, Rutherford Backscattering Spectroscopy, and Infrared Variable Angle Spectroscopic Ellipsometry among others. Different approaches (Spectroscopic Ellipsometry and Infrared Ellipsometry, the measurement of mechanical stress) have been used to evaluate the amount of water in thin films. The results on the density of films and the presence of water in the films obtained by the different methods are in good agreement. It was found that the critical energy values giving rise to dense and stable optical coatings of silicon dioxide and titanium dioxide are 25 eV/atom and 45 eV/atom, respectively. Moreover, this work presents the methodology developed to determine the ion current density distribution on the surface of a substrate holder of a dome shape for different positions relative to the ion source. The proposed analysis can be used as an effective tool for the construction of an industrial reactor and for its appropriate optimization.
Intravenous fluids: balancing solutions.
Hoorn, Ewout J
2017-08-01
The topic of intravenous (IV) fluids may be regarded as "reverse nephrology", because nephrologists usually treat to remove fluids rather than to infuse them. However, because nephrology is deeply rooted in fluid, electrolyte, and acid-base balance, IV fluids belong in the realm of our specialty. The field of IV fluid therapy is in motion due to the increasing use of balanced crystalloids, partly fueled by the advent of new solutions. This review aims to capture these recent developments by critically evaluating the current evidence base. It will review both indications and complications of IV fluid therapy, including the characteristics of the currently available solutions. It will also cover the use of IV fluids in specific settings such as kidney transplantation and pediatrics. Finally, this review will address the pathogenesis of saline-induced hyperchloremic acidosis, its potential effect on outcomes, and the question if this should lead to a definitive switch to balanced solutions.
[Hydroxyethyl starch solutions].
Reingardiene, Dagmara
2005-01-01
Hypovolemia is common among surgical, trauma, and intensive care unit patients. It can occur in the absence of obvious fluid loss secondary to vasodilatation or during generalized alterations of the endothelial barrier resulting in increased capillary permeability. Hydroxyethyl starch solutions are increasingly used for the volume replacement therapy. Hydroxyethyl starch solutions are synthetic colloids with the pharmacological properties that are the closest to natural colloids. Important characteristics for these products are molecular weight, their concentration, the degree of molar substitution, and the substitution pattern. In this review article a large variety of hydroxyethyl starch solutions, their physical and chemical characteristics, pharmacokinetics and metabolism, the main route of elimination, mechanism of action, effect on blood plasma volume, safety, tolerability and side effects (the risk of adverse effects on hemostasis, platelet function, frequency of pruritus, anaphylactoid reaction, incidence of rise in serum amylase) are presented.
Decontamination solution development studies
Allen, R.P.; Fetrow, L.K.; Kjarmo, H.E.; Pool, K.H.
1993-09-01
This study was conducted for the Westinghouse Hanford Company (WHC) by Pacific Northwest Laboratory (PNL) as part of the Hanford Grout Technology Program (HGTP). The objective of this study was to identify decontamination solutions capable of removing radioactive contaminants and grout from the Grout Treatment Facility (GTF) process equipment and to determine the impact of these solutions on equipment components and disposal options. The reference grout used in this study was prepared with simulated double-shell slurry feed (DSSF) and a dry blend consisting of 40 wt % limestone flour, 28 wt % blast furnace slag, 28 wt % fly ash, and 4 wt % type I/II Portland cement.
Fissile solution measurement apparatus
Crane, T.W.; Collinsworth, P.R.
1984-06-11
An apparatus for determining the content of a fissile material within a solution by detecting delayed fission neutrons emitted by the fissile material after it is temporarily irradiated by a neutron source. The apparatus comprises a container holding the solution and having a portion defining a neutron source cavity centrally disposed within the container. The neutron source cavity temporarily receives the neutron source. The container has portions defining a plurality of neutron detector ports that form an annular pattern and surround the neutron source cavity. A plurality of neutron detectors count delayed fission neutrons emitted by the fissile material. Each neutron detector is located in a separate one of the neutron detector ports.
Deconstructing graphite: graphenide solutions.
Pénicaud, Alain; Drummond, Carlos
2013-01-15
Growing interest in graphene over past few years has prompted researchers to find new routes for producing this material other than mechanical exfoliation or growth from silicon carbide. Chemical vapor deposition on metallic substrates now allows researchers to produce continuous graphene films over large areas. In parallel, researchers will need liquid, large scale, formulations of graphene to produce functional graphene materials that take advantage of graphene's mechanical, electrical, and barrier properties. In this Account, we describe methods for creating graphene solutions from graphite. Graphite provides a cheap source of carbon, but graphite is insoluble. With extensive sonication, it can be dispersed in organic solvents or water with adequate additives. Nevertheless, this process usually creates cracks and defects in the graphite. On the other hand, graphite intercalation compounds (GICs) provide a means to dissolve rather than disperse graphite. GICS can be obtained through the reaction of alkali metals with graphite. These compounds are a source of graphenide salts and also serve as an excellent electronic model of graphene due to the decoupling between graphene layers. The graphenide macroions, negatively charged graphene sheets, form supple two-dimensional polyelectrolytes that spontaneously dissolve in some organic solvents. The entropic gain from the dissolution of counterions and the increased degrees of freedom of graphene in solution drives this process. Notably, we can obtain graphenide solutions in easily processable solvents with low boiling points such as tetrahydrofuran or cyclopentylmethylether. We performed a statistical analysis of high resolution transmission electronic micrographs of graphene sheets deposited on grids from GICs solution to show that the dissolved material has been fully exfoliated. The thickness distribution peaks with single layers and includes a few double- or triple-layer objects. Light scattering analysis of the
Plutonium in Concentrated Solutions
Clark, Sue B.; Delegard, Calvin H.
2002-08-01
Complex, high ionic strength media are used throughout the plutonium cycle, from its processing and purification in nitric acid, to waste storage and processing in alkaline solutions of concentrated electrolytes, to geologic disposal in brines. Plutonium oxidation/reduction, stability, radiolysis, solution and solid phase chemistry have been studied in such systems. In some cases, predictive models for describing Pu chemistry under such non-ideal conditions have been developed, which are usually based on empirical databases describing specific ion interactions. In Chapter 11, Non-Ideal Systems, studies on the behavior of Pu in various complex media and available model descriptions are reviewed.
Dimensionally continued wormhole solutions
Li, X. School of Science, East China University of Science Technology, Shanghai 200237 )
1994-09-15
In this paper we consider wormhole solutions for the action of special Lovelock gravity'' recently discussed by Banados, Teitelboim, and Zanelli. This action is, in odd dimensions, the Chern-Simons form for the anti--de Sitter group and, in even dimensions, the Euler density constructed with the Lorentz part of the anti--de Sitter curvature tensor. We present a systematic study of classical wormhole solutions in the special Lovelock theory with various matter content, including a perfect fluid energy-momentum tensor, axionic field, and conformal scalar field.
NASA Astrophysics Data System (ADS)
Lennon, Daniel
2009-07-01
Wavelength dispersion solutions will be determined on a yearly basis as part of a long-term monitoring program. Deep engineering wavecals for each MAMA grating will be obtained at common cenwaves. Intermediate settings will also be taken to check the reliability of derived dispersion solutions. Final selection was determined on basis of past monitoring and C17 requirements. The internal wavelength calibrations will be taken using the LINE line lamp. Extra-deep wavecals are included for some echelle modes and first order modes to ensure detection of weak lines.
An Inexpensive Solution Calorimeter
ERIC Educational Resources Information Center
Kavanagh, Emma; Mindel, Sam; Robertson, Giles; Hughes, D. E. Peter
2008-01-01
We describe the construction of a simple solution calorimeter, using a miniature bead thermistor as a temperature-sensing element. This has a response time of a few seconds and made it possible to carry out a thermometric reaction in under a minute, which led to minimal heat losses. Small temperature changes of 1 K associated with enthalpies of…
ERIC Educational Resources Information Center
Finlay, Grace
2011-01-01
This article explores the effectiveness of using Solution Focused Brief Therapy (SFBT) in an adult learning environment. Within this discourse, special attention is given to show how SFBT can be used effectively to support the increasing number of adults who find themselves out of work who are now returning to education. Key ideas within SFBT will…
Cells and Hypotonic Solutions.
ERIC Educational Resources Information Center
Bery, Julia
1985-01-01
Describes a demonstration designed to help students better understand the response of plant and animal cells to hypotonic solutions. The demonstration uses a balloon inside a flexible, thin-walled cardboard box. Air going in corresponds to water entering by osmosis, and, like real cells, if stretched enough, the balloon will burst. (DH)
Maintenance Crisis vs Solutions.
ERIC Educational Resources Information Center
Haggard, Susie
Industrial maintenance in Northeast Georgia is facing an acute crisis. Contributing factors are economic development that is depleting the work force, aging of the population, downsizing of the military, and lack of technical school graduates. Solutions to the crisis fall into three categories: short-term, mid-term, and long-term. For short-term…
Crystallochemiluminescence of solutions
NASA Astrophysics Data System (ADS)
Gus'kov, A. P.; Nekrasova, L. P.; Gornakova, A. S.; Shikunova, I. A.
2014-09-01
It is shown that the chemiluminescence intensity from luminol solutions reaches a maximum when the latter are crystallized. This phenomenon is explained by the complex dynamics of the phase transition, chemical reactions, and degradation of electronic excitation energy. Luminescence of new type, called crystallochemiluminescence, is revealed.
Maintenance Crisis vs Solutions.
ERIC Educational Resources Information Center
Haggard, Susie
Industrial maintenance in Northeast Georgia is facing an acute crisis. Contributing factors are economic development that is depleting the work force, aging of the population, downsizing of the military, and lack of technical school graduates. Solutions to the crisis fall into three categories: short-term, mid-term, and long-term. For short-term…
ERIC Educational Resources Information Center
Cummings, Lynda; Winston, Michael
1998-01-01
Describes the Solutions model used at Shelley High School in Idaho which gives students the opportunity to gain practical experience while tackling community problems. This approach is built on the three fundamentals of an integrated curriculum, a problem-solving focus, and service-based learning. Sample problems include increasing certain trout…
An Inexpensive Solution Calorimeter
ERIC Educational Resources Information Center
Kavanagh, Emma; Mindel, Sam; Robertson, Giles; Hughes, D. E. Peter
2008-01-01
We describe the construction of a simple solution calorimeter, using a miniature bead thermistor as a temperature-sensing element. This has a response time of a few seconds and made it possible to carry out a thermometric reaction in under a minute, which led to minimal heat losses. Small temperature changes of 1 K associated with enthalpies of…
ERIC Educational Resources Information Center
NatureScope, 1989
1989-01-01
Examines some of the reasons tropical rain forests are being destroyed and ways people are working to protect these forests. Provides activities on how people can help, reason for saving the forests, individual actions related to forest problems and solutions, and issues and problems. Three copyable pages accompany activities. (Author/RT)
Antisocial Personalities, Antidemocractic Solutions.
ERIC Educational Resources Information Center
Schneiderman, Howard G.
1996-01-01
Provides critical analysis of David T. Lykken's article "Psychopathy, Sociopathy, and Crime" (1996) and its correlation between unstable families and sociopathy and the use of parental licensing as a solution. Discusses reasons for the appeal of parental licensing as well as the issue of state control replacing social control. (GR)
ERIC Educational Resources Information Center
Cummings, Lynda; Winston, Michael
1998-01-01
Describes the Solutions model used at Shelley High School in Idaho which gives students the opportunity to gain practical experience while tackling community problems. This approach is built on the three fundamentals of an integrated curriculum, a problem-solving focus, and service-based learning. Sample problems include increasing certain trout…
Cells and Hypotonic Solutions.
ERIC Educational Resources Information Center
Bery, Julia
1985-01-01
Describes a demonstration designed to help students better understand the response of plant and animal cells to hypotonic solutions. The demonstration uses a balloon inside a flexible, thin-walled cardboard box. Air going in corresponds to water entering by osmosis, and, like real cells, if stretched enough, the balloon will burst. (DH)
Making and diluting stock solutions.
Adams, Dany Spencer
2008-05-01
INTRODUCTIONFor particular experiments, certain solutions are used frequently and are therefore made up in large quantities. To minimize the volume actually occupied by these solutions, they are often made at a higher concentration than that which will be used. These concentrated solutions are referred to as stock solutions. Stock solutions save time in addition to space; when you need a solution of a given concentration, you need only dilute the stock rather than starting from scratch. This article describes the steps necessary to make and dilute stock solutions appropriately.
Solute transport in groundwater
NASA Astrophysics Data System (ADS)
Dougherty, David E.
Continued research interest in transport in the subsurface was demonstrated at the “Solute Transport in Groundwater” session held at the 1985 AGU Spring Meeting in Baltimore. This session, following on the heels of the very successful special symposium on “Coupling Geochemical and Hydrologic Models for Subsurface Solute Transport,” was organized by Lenny Konikow of the U.S. Geological Survey (USGS, Reston, Va.) and copresided by Steve Gorelick (USGS, Menlo Park, Calif.) and David Dougherty (Princeton University, Princeton, N.J.). Participation was strong, with 12 contributed papers and about 150 attendees. The papers addressed a wide variety of topics, ranging from the theoretical to the applied, from physics to numerical methods.
NASA Technical Reports Server (NTRS)
Turner, L. R.
1960-01-01
The problem of solving systems of nonlinear equations has been relatively neglected in the mathematical literature, especially in the textbooks, in comparison to the corresponding linear problem. Moreover, treatments that have an appearance of generality fail to discuss the nature of the solutions and the possible pitfalls of the methods suggested. Probably it is unrealistic to expect that a unified and comprehensive treatment of the subject will evolve, owing to the great variety of situations possible, especially in the applied field where some requirement of human or mechanical efficiency is always present. Therefore we attempt here simply to pose the problem and to describe and partially appraise the methods of solution currently in favor.
NASA Astrophysics Data System (ADS)
Schmitz, G. J.; Engstrom, A.; Bernhardt, R.; Prahl, U.; Adam, L.; Seyfarth, J.; Apel, M.; de Saracibar, C. Agelet; Korzhavyi, P.; Ågren, J.; Patzak, B.
2016-01-01
The Integrated Computational Materials Engineering expert group (ICMEg), a coordination activity of the European Commission, aims at developing a global and open standard for information exchange between the heterogeneous varieties of numerous simulation tools. The ICMEg consortium coordinates respective developments by a strategy of networking stakeholders in the first International Workshop on Software Solutions for ICME, compiling identified and relevant software tools into the Handbook of Software Solutions for ICME, discussing strategies for interoperability between different software tools during a second (planned) international workshop, and eventually proposing a scheme for standardized information exchange in a future book or document. The present article summarizes these respective actions to provide the ICME community with some additional insights and resources from which to help move this field forward.
Analytic Parabolic Equation Solutions.
1989-11-01
problem involving a line source in a homogeneous ocean above a homogeneous , semi-infinite, fast fluid bottom has been analyzed in detail. Various...excited duct with laterally homogeneous bilinear height profile. An exact numerical reference solution can be constructed by modal summation for...have been well documented in the literature [1]. Since the final-field is constructed by beam shooting, one avoids the need for eigenray search which
Fletcher, Mary H.; Warner, E. Ray
1953-01-01
description of and complete drawings for the construction of a fluorimeter for the measurement of fluorescence of solutions are given. The instrument is sturdy and versatile. It may be used with various phototubes and measuring devices. It is constructed so that phototubes and filters may be changed readily. Sensitivity is controlled easily over a wide range by limiting the size of either the ultraviolet or fluorescent light beam with standard apertures.
Solution Processing - Rodlike Polymers
1979-08-01
side it necessary and identify by block number) Para-ordered Polymers High Modulus Fibers and Films Polybenzobisoxazoles Polybenzobisthiazoles 20...considerations important in solution processing are considered, with special emphasis on the dry-jet wet spinning process used to form fibers . Pertinent...Company, Summit, N.J. iii TABLE OF CONTENTS 1. INTRODUCTION ................ .......................... .. 1 2. REMARKS ON DRY-JET WET SPUN FIBER
Electrolytes: Oral Electrolyte Solutions.
Harris, Lisa
2017-08-01
Oral electrolyte solutions are used widely for rehydration in diarrheal illness and to maintain hydration during vigorous exercise. In diarrheal illness, an oral rehydration solution (ORS) typically is preferred over intravenous fluids except for patients with severe dehydration. The preferred ORS is one similar to the glucose-containing reduced osmolarity World Health Organization ORS. There also are polymer-based solutions that use rice or wheat as the source of carbohydrates but these are not widely recommended. Use of other liquids, such as sport drinks, juice, soft drinks, and chicken broth is not recommended, though these can be considered for patients with no or mild dehydration. For maintaining hydration during exercise, particularly vigorous high-intensity exercise, recommendations are to consume fluids (ie, 5 to 7 mL/kg) and a sodium-containing snack at least 4 hours before. During exercise, individuals require 200 to 800 mL/hour of liquid that should contain 20 to 30 mEq/L of sodium. Carbohydrate intake is recommended during high-intensity exercise. Intake of excessive sodium-free fluids should be avoided to prevent exercise-induced hyponatremia. Additional fluids (ie, 1.5 L/kg of weight lost) can be consumed after exercise to restore hydration. Vitamin and mineral supplements are not recommended routinely for athletes unless known deficiencies exist. Written permission from the American Academy of Family Physicians is required for reproduction of this material in whole or in part in any form or medium.
Platelet additive solution - electrolytes.
Azuma, Hiroshi; Hirayama, Junichi; Akino, Mitsuaki; Ikeda, Hisami
2011-06-01
Recent attention to solutions that replace most or all plasma in platelet concentrates, while maintaining satisfactory platelet function, is motivated by the potential of plasma reduction or depletion to mitigate various transfusion-related adverse events. This report considers the electrolytic composition of previously described platelet additive solutions, in order to draw general conclusions about what is required for platelet function and longevity. The optimal concentrations of Na(+) and Cl(-) are 69-115 mM. The presence of both K(+) and Mg(2+) in platelet suspension at nearly physiological concentrations (3-5mM and 1.5-3mM, respectively) is indispensable for good preservation capacity because both electrolytes are required to prevent platelet activation. In contrast to K(+) and Mg(2+), Ca(2+) may not be important because no free Ca(2+) is available in M-sol, which showed excellent platelet preservation capacity at less than 5% plasma concentration. The importance of bicarbonate (approximately 40 mM) can be recognized when the platelets are suspended in additive solution under less than 5% residual plasma concentration.
Apparatus Makes Precisely Saturated Solutions
NASA Technical Reports Server (NTRS)
Pusey, Marc L.
1989-01-01
Simple laboratory apparatus establishes equilibrium conditions of temperature and concentration in solutions for use in precise measurements of saturation conditions. With equipment typical measurement of saturation concentration of protein in solution established and measured within about 24 hours. Precisely saturated solution made by passing solvent or solution slowly along column packed with solute at precisely controlled temperature. If necessary, flow stopped for experimentally determined interval to allow equilibrium to be established in column.
Rapid Regional Centroid Solutions
NASA Astrophysics Data System (ADS)
Wei, S.; Zhan, Z.; Luo, Y.; Ni, S.; Chen, Y.; Helmberger, D. V.
2009-12-01
The 2008 Wells Nevada Earthquake was recorded by 164 broadband USArray stations within a distance of 550km (5 degrees) with all azimuths uniformly sampled. To establish the source parameters, we applied the Cut and Paste (CAP) code to all the stations to obtain a mechanism (strike/dip/rake=35/41/-85) at a depth of 9km and Mw=5.9. Surface wave shifts range from -8s to 8s which are in good agreement with ambient seismic noise (ASN) predictions. Here we use this data set to test the accuracy of the number of stations needed to obtain adequate solutions (position of the compressional and tension axis) for mechanism. The stations were chosen at random where combinations of Pnl and surface waves were used to establish mechanism and depth. If the event is bracketed by two stations, we obtain an accurate magnitude with good solutions about 80% of the trials. Complete solutions from four stations or Pnl from 10 stations prove reliable in nearly all situations. We also explore the use of this dataset in locating the event using a combination of surface wave travel times and/or the full waveform inversion (CAPloc) that uses the CAP shifts to refine locations. If the mechanism is known (fixed) only a few stations is needed to locate an event to within 5km if date is available at less than 150km. In contrast, surface wave travel times (calibrated to within one second) produce amazing accurate locations with only 6 stations reasonably distributed. It appears this approach is easily automated as suggested by Scrivner and Helmberger (1995) who discussed travel times of Pnl and surface waves and the evolving of source accuracy as the various phases arrive.
Shuttle Wastewater Solution Characterization
NASA Technical Reports Server (NTRS)
Adam, Niklas; Pham, Chau
2011-01-01
During the 31st shuttle mission to the International Space Station, STS-129, there was a clogging event in the shuttle wastewater tank. A routine wastewater dump was performed during the mission and before the dump was completed, degraded flow was observed. In order to complete the wastewater dump, flow had to be rerouted around the dump filter. As a result, a basic chemical and microbial investigation was performed to understand the shuttle wastewater system and perform mitigation tasks to prevent another blockage. Testing continued on the remaining shuttle flights wastewater and wastewater tank cleaning solutions. The results of the analyses and the effect of the mitigation steps are detailed in this paper.
Dirac solutions for quaternionic potentials
De Leo, Stefano Giardino, Sergio
2014-02-15
The Dirac equation is solved for quaternionic potentials, i V{sub 0} + j W{sub 0} (V{sub 0}∈R , W{sub 0}∈C). The study shows two different solutions. The first one contains particle and anti-particle solutions and leads to the diffusion, tunneling, and Klein energy zones. The standard solution is recovered taking the complex limit of this solution. The second solution, which does not have a complex counterpart, can be seen as a V{sub 0}-antiparticle or |W{sub 0}|-particle solution.
Solute-Filled Syringe For Formulating Intravenous Solution
NASA Technical Reports Server (NTRS)
Owens, Jim; Bindokas, AL; Dudar, Tom; Finley, Mike; Scharf, Mike
1993-01-01
Prefilled syringe contains premeasured amount of solute in powder or concentrate form used to deliver solute to sterile interior of large-volume parenteral (LVP) bag. Predetermined amount of sterile water also added to LVP bag through sterilizing filter, and mixed with contents of syringe, yielding sterile intravenous solution of specified concentration.
NASA Technical Reports Server (NTRS)
2001-01-01
REI Systems, Inc. developed a software solution that uses the Internet to eliminate the paperwork typically required to document and manage complex business processes. The data management solution, called Electronic Handbooks (EHBs), is presently used for the entire SBIR program processes at NASA. The EHB-based system is ideal for programs and projects whose users are geographically distributed and are involved in complex management processes and procedures. EHBs provide flexible access control and increased communications while maintaining security for systems of all sizes. Through Internet Protocol- based access, user authentication and user-based access restrictions, role-based access control, and encryption/decryption, EHBs provide the level of security required for confidential data transfer. EHBs contain electronic forms and menus, which can be used in real time to execute the described processes. EHBs use standard word processors that generate ASCII HTML code to set up electronic forms that are viewed within a web browser. EHBs require no end-user software distribution, significantly reducing operating costs. Each interactive handbook simulates a hard-copy version containing chapters with descriptions of participants' roles in the online process.
Lee, Chon-Lin; Lee, Jiu-Chang
2002-04-01
This study presents an admicellar enhanced continuous-flow stirred tank reactor (CSTR). Solutions containing single and binary aliphatic alcohols are introduced into this reactor for breakthrough experiments. Two phenomena occur during experiments with binary solutes: (a) a competitive effect caused by background solutes with relatively high hydrophobicity; (b) a co-solvent effect attributable to background solutes with relatively low hydrophobicity. The competition phenomenon and the corresponding mechanism involved are well demonstrated by directly monitoring the pre-adsolubilized solutes drawn out back to the solution while adsolubilizing other solutes with higher hydrophobicity. On the other hand, adsolubilization kinetics hindered by the background solute, which acts as a co-solvent, significantly alters the slopes of breakthrough curves of the target solute treated in the reactor.
Resolved conifolds in supergravity solutions
Ghezelbash, A. M.
2008-01-15
We construct generalized 11D supergravity solutions of fully localized intersecting D2/D4 brane systems. These solutions are obtained by embedding six-dimensional resolved Eguchi-Hanson conifolds lifted to M-theory. We reduce these solutions to ten dimensions, obtaining new D-brane systems in type IIA supergravity. We discuss the limits in which the dynamics of the D2 brane decouples from the bulk for these solutions.
Immersion lithography bevel solutions
NASA Astrophysics Data System (ADS)
Tedeschi, Len; Tamada, Osamu; Sanada, Masakazu; Yasuda, Shuichi; Asai, Masaya
2008-03-01
The introduction of Immersion lithography, combined with the desire to maximize the number of potential yielding devices per wafer, has brought wafer edge engineering to the forefront for advanced semiconductor manufactures. Bevel cleanliness, the position accuracy of the lithography films, and quality of the EBR cut has become more critical. In this paper, the effectiveness of wafer track based solutions to enable state-of-art bevel schemes is explored. This includes an integrated bevel cleaner and new bevel rinse nozzles. The bevel rinse nozzles are used in the coating process to ensure a precise, clean film edge on or near the bevel. The bevel cleaner is used immediately before the wafer is loaded into the scanner after the coating process. The bevel cleaner shows promise in driving down defectivity levels, specifically printing particles, while not damaging films on the bevel.
NASA Technical Reports Server (NTRS)
1997-01-01
Cogent Software, Inc. was formed in January 1995 by David Atkinson and Irene Woerner, both former employees of the Jet Propulsion Laboratory (JPL). Several other Cogent employees also worked at JPL. Atkinson headed JPL's Information Systems Technology section and Woerner lead the Advanced User Interfaces Group. Cogent's mission is to help companies organize and manage their online content by developing advanced software for the next generation of online directories and information catalogs. The company offers a complete range of Internet solutions, including Internet access, Web site design, local and wide-area networks, and custom software for online commerce applications. Cogent also offers DesignSphere Online, an electronic community for the communications arts industry. Customers range from small offices to manufacturers with thousands of employees, including Chemi-Con, one of the largest manufacturers of capacitors in the world.
2010 Water & Aqueous Solutions
Dor Ben-Amotz
2010-08-13
Water covers more than two thirds of the surface of the Earth and about the same fraction of water forms the total mass of a human body. Since the early days of our civilization water has also been in the focus of technological developments, starting from converting it to wine to more modern achievements. The meeting will focus on recent advances in experimental, theoretical, and computational understanding of the behavior of the most important and fascinating liquid in a variety of situations and applications. The emphasis will be less on water properties per se than on water as a medium in which fundamental dynamic and reactive processes take place. In the following sessions, speakers will discuss the latest breakthroughs in unraveling these processes at the molecular level: Water in Solutions; Water in Motion I and II; Water in Biology I and II; Water in the Environment I and II; Water in Confined Geometries and Water in Discussion (keynote lecture and poster winners presentations).
Manning, Timmy; Sleator, Roy D; Walsh, Paul
2013-01-01
For decades, computer scientists have looked to nature for biologically inspired solutions to computational problems; ranging from robotic control to scheduling optimization. Paradoxically, as we move deeper into the post-genomics era, the reverse is occurring, as biologists and bioinformaticians look to computational techniques, to solve a variety of biological problems. One of the most common biologically inspired techniques are genetic algorithms (GAs), which take the Darwinian concept of natural selection as the driving force behind systems for solving real world problems, including those in the bioinformatics domain. Herein, we provide an overview of genetic algorithms and survey some of the most recent applications of this approach to bioinformatics based problems. PMID:23222169
Knop's Solution Is Not What It Seems.
ERIC Educational Resources Information Center
Hershey, David R.
2001-01-01
Discusses Knob's solution, which was considered the ideal plant growth solution in 1865, and recommends eliminating Knob's solution from active teaching. Describes solution culture basics including nutrient solutions, containers and aeration, and plants and light. (Contains 12 references.) (YDS)
Knop's Solution Is Not What It Seems.
ERIC Educational Resources Information Center
Hershey, David R.
2001-01-01
Discusses Knob's solution, which was considered the ideal plant growth solution in 1865, and recommends eliminating Knob's solution from active teaching. Describes solution culture basics including nutrient solutions, containers and aeration, and plants and light. (Contains 12 references.) (YDS)
VASOACTIVE COMPONENTS OF DIALYSIS SOLUTION
Zakaria, El Rasheid; Patel, Anuj A.; Li, Na; Matheson, Paul J.; Garrison, Richard N.
2008-01-01
Background Conventional peritoneal dialysis (PD) solutions elicit vasodilation, which is implicated in the variable rate of solute transport during the dwell. The components causing such vasoactivity are still controversial. This study was conducted to define the vasoactive components of conventional and new PD solutions. Methods Three visceral peritoneal microvascular levels were visualized by intravital video microscopy of the terminal ileum of anesthetized rats. Anesthesia-free decerebrate conscious rats served as control. Microvascular diameter and blood flow by Doppler measurements were conducted after topical peritoneal exposure to 4 clinical PD solutions and 6 prepared solutions designed to isolate potential vasoactive components of the PD solution. Results All clinically available PD solutions produced a rapid and generalized vasodilation at all intestinal microvascular levels, regardless of the osmotic solute. The pattern and magnitude of this dilation was not affected by anesthesia but was determined by arteriolar size, the osmotic solute, and the solution’s buffer anion system. The greatest dilation occurred in the small precapillary arterioles and was elicited by conventional PD solution and heat re-sterilized solution containing low glucose degradation products (GDPs). Hypertonic mannitol solutions produced a dilation that was approximately 50% less than the dilation obtained with glucose solutions with identical osmolarity and buffer. Increasing a solution’s osmolarity did not produce a parallel increase in the magnitude of dilation, suggesting a nonlinear relationship between the two variables. Lactate dissolved in an isotonic solution was completely non-vasoactive unless the solution’s H+ concentration was increased. At low pH, isotonic lactate produced a rapid but transient vasodilation. This vascular reactivity was similar in magnitude and pattern to that obtained with the isotonic 7.5% icodextrin solution (Extraneal; Baxter Healthcare
Molecular Aggregates in Cryogenic Solutions.
1981-07-07
of aggregates from solutions of monomers. Rapid deposition into a precooled sample cell is required to generate an aggregate solution. Such a solution...U AU-A11b 490 COLORAO0 STATE UNIV FORT COLLINS DEPT OF CHEMISTRY F/G 20/8 MOLECULAR AGGREGATES IN CRYOGENIC SOLUTIONS.CU) JUL 81 M W SCHAUER- J LEE...MOLECULAR AGGREGATES IN CRYOGENIC SOLUTIONS by M.W. Schauer, J. Lee, and E.R. Bernstein Prepared for Publication in The Journal of Chemical Physics
NASA Astrophysics Data System (ADS)
Silliman, S. E.; Zheng, L.; Conwell, P.
éories stochastiques récentes. En outre, la technologie des capteurs de pression et les méthodes de visualisation donnent la possibilité d'utiliser les ISE pour caractériser les distributions spatiales à la fois de la piézométrie et de la vitesse locale de l'eau dans un champs de perméabilités corrélées. Finalement, des méthodes variées peuvent être utilisées pour caractériser les variations temporelles de la distribution spatiale (et, par conséquent, les moments spatiaux) des concentrations de soluté dans les ISE. En conclusion, donc, des développements récents des techniques expérimentales ont fourni l'occasion d'utiliser les ISE comme d'importants outils d'étude en continu des écoulement de fluides et de transport de solutés conservatifs dans des milieux poreux saturés hétérogènes. Resumen Los experimentos de laboratorio en medio poroso heterogéneo (conocidos como Experimentos a Escala Intermedia o ISE) están cada vez mejor considerados para el estudio de los sistemas saturados y no saturados. Entre las muchas aplicaciones de los ISE se encuentra el estudio del flujo y el transporte de solutos conservativos en medios con permeabilidad que presentan una cierta estructura de correlación. Avances recientes en el diseño de los ISE han proporcionado la capacidad de crear medios de este tipo en el laboratorio. Esta capacidad es importante para la aplicación de los ISE a la evaluación de las teorías estocásticas recientes. Además, la tecnología de los transductores de presión y los métodos de visualización han permitido que los ISE se usen para caracterizar la distribución espacial de niveles hidráulicos y de las velocidades locales del agua en campos de permeabilidad con determinada correlación espacial. Finalmente, existen varios métodos para caracterizar las variaciones temporales en la distribución espacial (y por tanto los momentos estadísticos espaciales) de la concentración de solutos en los ISE. Se concluye que los desarrollos
Various Boussinesq solitary wave solutions
Yates, G.T.
1995-12-31
The generalized Boussinesq (gB) equations have been used to model nonlinear wave evolution over variable topography and wave interactions with structures. Like the KdV equation, the gB equations support a solitary wave solution which propagates without changing shape, and this solitary wave is often used as a primary test case for numerical studies of nonlinear waves using either the gB or other model equations. Nine different approximate solutions of the generalized Boussinesq equations are presented with simple closed form expressions for the wave elevation and wave speed. Each approximates the free propagation of a single solitary wave, and eight of these solutions are newly obtained. The author compares these solutions with the well known KdV solution, Rayleigh`s solution, Laitone`s higher order solution, and ``exact`` numerical integration of the gB equations. Existing experimental data on solitary wave shape and wave speed are compared with these models.
Asymptotic solutions in asymptotic safety
NASA Astrophysics Data System (ADS)
Gonzalez-Martin, Sergio; Morris, Tim R.; Slade, Zoë H.
2017-05-01
We explain how to find the asymptotic form of fixed point solutions in functional truncations, in particular f (R ) approximations. We find that quantum fluctuations do not decouple at large R , typically leading to elaborate asymptotic solutions containing several free parameters. By a counting argument, these can be used to map out the dimension of the fixed point solution spaces. They are also necessary to validate the numerical solution and provide the physical part in the limit that the cutoff is removed: the fixed point equation of state. As an example, we apply the techniques to a recent f (R ) approximation by Demmel et al., finding asymptotic matches to their numerical solution. Depending on the value of the endomorphism parameter, we find many other asymptotic solutions and fixed point solution spaces of differing dimensions, yielding several alternative scenarios for the equation of state. Asymptotic studies of other f (R ) approximations are needed to clarify the picture.
Insight solutions are correct more often than analytic solutions
Salvi, Carola; Bricolo, Emanuela; Kounios, John; Bowden, Edward; Beeman, Mark
2016-01-01
How accurate are insights compared to analytical solutions? In four experiments, we investigated how participants’ solving strategies influenced their solution accuracies across different types of problems, including one that was linguistic, one that was visual and two that were mixed visual-linguistic. In each experiment, participants’ self-judged insight solutions were, on average, more accurate than their analytic ones. We hypothesised that insight solutions have superior accuracy because they emerge into consciousness in an all-or-nothing fashion when the unconscious solving process is complete, whereas analytic solutions can be guesses based on conscious, prematurely terminated, processing. This hypothesis is supported by the finding that participants’ analytic solutions included relatively more incorrect responses (i.e., errors of commission) than timeouts (i.e., errors of omission) compared to their insight responses. PMID:27667960
Silverstein, Eva; /Stanford U., Phys. Dept. /SLAC
2008-01-07
We present a framework for de Sitter model building in type IIA string theory, illustrated with specific examples. We find metastable dS minima of the potential for moduli obtained from a compactification on a product of two Nil three-manifolds (which have negative scalar curvature) combined with orientifolds, branes, fractional Chern-Simons forms, and fluxes. As a discrete quantum number is taken large, the curvature, field strengths, inverse volume, and four dimensional string coupling become parametrically small, and the de Sitter Hubble scale can be tuned parametrically smaller than the scales of the moduli, KK, and winding mode masses. A subtle point in the construction is that although the curvature remains consistently weak, the circle fibers of the nilmanifolds become very small in this limit (though this is avoided in illustrative solutions at modest values of the parameters). In the simplest version of the construction, the heaviest moduli masses are parametrically of the same order as the lightest KK and winding masses. However, we provide a method for separating these marginally overlapping scales, and more generally the underlying supersymmetry of the model protects against large corrections to the low-energy moduli potential.
Burns, D.A.
1994-09-01
A fully automated analyzer has been developed for plutonium solutions. It was assembled from several commercially available modules, is based upon segmented flow analysis, and exhibits precision about an order of magnitude better than commercial units (0.5%-O.05% RSD). The system was designed to accept unmeasured, untreated liquid samples in the concentration range 40-240 g/L and produce a report with sample identification, sample concentrations, and an abundance of statistics. Optional hydraulics can accommodate samples in the concentration range 0.4-4.0 g/L. Operating at a typical rate of 30 to 40 samples per hour, it consumes only 0.074 mL of each sample and standard, and generates waste at the rate of about 1.5 mL per minute. No radioactive material passes through its multichannel peristaltic pump (which remains outside the glovebox, uncontaminated) but rather is handled by a 6-port, 2-position chromatography-type loop valve. An accompanying computer is programmed in QuickBASIC 4.5 to provide both instrument control and data reduction. The program is truly user-friendly and communication between operator and instrument is via computer screen displays and keyboard. Two important issues which have been addressed are waste minimization and operator safety (the analyzer can run in the absence of an operator, once its autosampler has been loaded).
NASA Technical Reports Server (NTRS)
2003-01-01
From the company that brought the world an integral heating and cooling food service system after originally developing it for NASA's Apollo Program, comes yet another orbital offshoot: a product that can be as thin as paper and as strong as steel. Nextel Ceramic Textiles and Composites from 3M Company offer space-age protection and innovative solutions for hot situations, ranging from NASA to NASCAR. With superior thermal protection, Nextel fabrics, tape, and sleevings outperform other high temperature textiles such as aramids, carbon, glass, and quartz, permitting engineers and manufacturers to handle applications up to 2,500 F (1,371 C). The stiffness and strength of Nextel Continuous Ceramic Fibers make them a great match for improving the rigidity of aluminum in metal matrix composites. Moreover, the fibers demonstrate low shrinkage at operating temperatures, which allow for the manufacturing of a dimensionally stable product. These novel fibers also offer excellent chemical resistance, low thermal conductivity, thermal shock resistance, low porosity, and unique electrical properties.
Silverstein, Eva
2008-05-15
We present a framework for de Sitter model building in type IIA string theory, illustrated with specific examples. We find metastable de Sitter (dS) minima of the potential for moduli obtained from a compactification on a product of two nil three-manifolds (which have negative scalar curvature) combined with orientifolds, branes, fractional Chern-Simons forms, and fluxes. As a discrete quantum number is taken large, the curvature, field strengths, inverse volume, and four-dimensional string coupling become parametrically small, and the de Sitter Hubble scale can be tuned parametrically smaller than the scales of the moduli, Kaluza Klein (KK), and winding mode masses. A subtle point in the construction is that although the curvature remains consistently weak, the circle fibers of the nilmanifolds become very small in this limit (though this is avoided in illustrative solutions at modest values of the parameters). In the simplest version of the construction, the heaviest moduli masses are parametrically of the same order as the lightest KK and winding masses. However, we provide a method for separating these marginally overlapping scales, and more generally the underlying supersymmetry of the model protects against large corrections to the low-energy moduli potential.
NASA Technical Reports Server (NTRS)
Izmailov, Alexander F.; Myerson, Allan S.
1995-01-01
The physical properties of a supersaturated binary solution such as its density rho, shear viscosity eta, and solute mass diffusivity D are dependent on the solute concentration c: rho = rho(c), eta = eta(c), and D = D(c). The diffusion boundary layer equations related to crystal growth from solution are derived for the case of natural convection with a solution density, a shear viscosity, and a solute diffusivity that are all depen- dent on solute concentration. The solution of these equations has demonstrated the following. (1) At the vicinity of the saturation concentration c(sub s) the solution shear viscosity eta depends on rho as eta(sub s) = eta(rho(sub s))varies as square root of rho(c(sub s)). This theoretically derived result has been verified in experiments with several aqueous solutions of inorganic and organic salts. (2) The maximum solute mass transfer towards the growing crystal surface can be achieved for values of c where the ratio of d ln(D(c)/dc) to d ln(eta(c)/dc) is a maximum.
Solution nonideality related to solute molecular characteristics of amino acids.
Keener, C R; Fullerton, G D; Cameron, I L; Xiong, J
1995-01-01
By measuring the freezing-point depression for dilute, aqueous solutions of all water-soluble amino acids, we test the hypothesis that nonideality in aqueous solutions is due to solute-induced water structuring near hydrophobic surfaces and solute-induced water destructuring in the dipolar electric fields generated by the solute. Nonideality is expressed with a single solute/solvent interaction parameter I, calculated from experimental measure of delta T. A related parameter, I(n), gives a method of directly relating solute characteristics to solute-induced water structuring or destructuring. I(n)-values correlate directly with hydrophobic surface area and inversely with dipolar strength. By comparing the nonideality of amino acids with progressively larger hydrophobic side chains, structuring is shown to increase with hydrophobic surface area at a rate of one perturbed water molecule per 8.8 square angstroms, implying monolayer coverage. Destructuring is attributed to dielectric realignment as described by the Debye-Hückel theory, but with a constant separation of charges in the amino-carboxyl dipole. By using dimers and trimers of glycine and alanine, this destructuring is shown to increase with increasing dipole strength using increased separation of fixed dipolar charges. The capacity to predict nonideal solution behavior on the basis of amino acid characteristics will permit prediction of free energy of transfer to water, which may help predict the energetics of folding and unfolding of proteins based on the characteristics of constituent amino acids. Images FIGURE 6 PMID:7711253
Properties of scintillator solutes
Fluornoy, J.M.
1998-06-01
This special report summarizes measurements of the spectroscopic and other properties of the solutes that were used in the preparation of several new liquid scintillators developed at EG and G/Energy Measurements/Santa Barbara Operations (the precursor to Bechtel Nevada/Special Technologies Laboratory) on the radiation-to-light converter program. The data on the individual compounds are presented in a form similar to that used by Prof. Isadore Berlman in his classic handbook of fluorescence spectra. The temporal properties and relative efficiencies of the new scintillators are presented in Table 1, and the efficiencies as a function of wavelength are presented graphically in Figure 1. In addition, there is a descriptive glossary of the abbreviations used herein. Figure 2 illustrates the basic structures of some of the compounds and of the four solvents reported in this summary. The emission spectra generally exhibit more structure than the absorption spectra, with the result that the peak emission wavelength for a given compound may lie several nm away from the wavelength, {lambda}{sub avg}, at the geometric center of the emission spectrum. Therefore, the author has chosen to list absorption peaks, {lambda}{sub max}, and emission {lambda}{sub avg} values in Figures 3--30, as being most illustrative of the differences between the compounds. The compounds, BHTP, BTPB, ADBT, and DPTPB were all developed on this program. P-terphenyl, PBD, and TPB are commercially available blue emitters. C-480 and the other longer-wavelength emitters are laser dyes available commercially from Exciton Corporation. 1 ref., 30 figs.
Thermodynamics of feldspathoid solutions
NASA Astrophysics Data System (ADS)
Sack, Richard O.; Ghiorso, Mark S.
We have developed models for the thermody-namic properties of nephelines, kalsilites, and leucites in the simple system NaAlSiO4-KAlSiO4-Ca0.5AlSiO4-SiO2-H2O that are consistent with all known constraints on subsolidus equilibria and thermodynamic properties, and have integrated them into the existing MELTS software package. The model for nepheline is formulated for the simplifying assumptions that (1) a molecular mixing-type approximation describes changes in the configurational entropy associated with the coupled exchange substitutions □Si?NaAl and □Ca? Na2 and that (2) Na+ and K+ display long-range non-convergent ordering between a large cation and the three small cation sites in the Na4Al4Si4O16 formula unit. Notable features of the model include the prediction that the mineral tetrakalsilite (``panunzite'', sensu stricto) results from anti-ordering of Na and K between the large cation and the three small cation sites in the nepheline structure at high temperatures, an average dT/dP slope of about 55°/kbar for the reaction
Iodine addition using triiodide solutions
NASA Technical Reports Server (NTRS)
Rutz, Jeffrey A.; Muckle, Susan V.; Sauer, Richard L.
1992-01-01
The study develops: a triiodide solution for use in preparing ground service equipment (GSE) water for Shuttle support, an iodine dissolution method that is reliable and requires minimal time and effort to prepare, and an iodine dissolution agent with a minimal concentration of sodium salt. Sodium iodide and hydriodic acid were both found to dissolve iodine to attain the desired GSE iodine concentrations of 7.5 +/- 2.5 mg/L and 25 +/- 5 mg/L. The 1.75:1 and 2:1 sodium iodide solutions produced higher iodine recoveries than the 1.2:1 hydriodic acid solution. A two-hour preparation time is required for the three sodium iodide solutions. The 1.2:1 hydriodic acid solution can be prepared in less than 5 min. Two sodium iodide stock solutions (2.5:1 and 2:1) were found to dissolve iodine without undergoing precipitation.
Iodine addition using triiodide solutions
NASA Technical Reports Server (NTRS)
Rutz, Jeffrey A.; Muckle, Susan V.; Sauer, Richard L.
1992-01-01
The study develops: a triiodide solution for use in preparing ground service equipment (GSE) water for Shuttle support, an iodine dissolution method that is reliable and requires minimal time and effort to prepare, and an iodine dissolution agent with a minimal concentration of sodium salt. Sodium iodide and hydriodic acid were both found to dissolve iodine to attain the desired GSE iodine concentrations of 7.5 +/- 2.5 mg/L and 25 +/- 5 mg/L. The 1.75:1 and 2:1 sodium iodide solutions produced higher iodine recoveries than the 1.2:1 hydriodic acid solution. A two-hour preparation time is required for the three sodium iodide solutions. The 1.2:1 hydriodic acid solution can be prepared in less than 5 min. Two sodium iodide stock solutions (2.5:1 and 2:1) were found to dissolve iodine without undergoing precipitation.
Cereal based oral rehydration solutions.
Kenya, P R; Odongo, H W; Oundo, G; Waswa, K; Muttunga, J; Molla, A M; Nath, S K; Molla, A; Greenough, W B; Juma, R
1989-07-01
A total of 257 boys (age range 4-55 months), who had acute diarrhoea with moderate to severe dehydration, were randomly assigned to treatment with either the World Health Organisation/United Nations Childrens Fund (WHO/Unicef) recommended oral rehydration solution or cereal based oral rehydration solution made either of maize, millet, sorghum, or rice. After the initial rehydration was achieved patients were offered traditional weaning foods. Treatment with oral rehydration solution continued until diarrhoea stopped. Accurate intake and output was maintained throughout the study period. Efficacy of the treatment was compared between the different treatment groups in terms of intake of the solution, stool output, duration of diarrhoea after admission, and weight gain after 24, 48, and 72 hours, and after resolution of diarrhoea. Results suggest that all the cereal based solutions were as effective as glucose based standard oral rehydration solution in the treatment of diarrhoea.
Peritoneal transport with icodextrin solution.
Heimbürger, Olof
2006-01-01
Icodextrin is the only large molecular weight osmotic agent available in peritoneal dialysis solutions. Icodextrin (compared to glucose) has a prolonged positive ultrafiltration because of the slow absortion of icodextrin due to its large molecular weight. As icodextrin induces transcapillary ultrafiltration by a mechanism resembling 'colloid' osmosis (with the ultrafiltration occurring mainly through the small pores) almost no sieving of solutes is observed with icodextrin-based solution resulting in increased convective transport and clearance of small solutes. In general, the transport characteristics of the peritoneal membrane are similar with glucose- and icodextrin-based solution, but results from the EAPOS study suggests that use of icodextrin-based solution may be associated with less changes in peritoneal transport with time.
Local fluctuations in solution mixtures
Ploetz, Elizabeth A.; Smith, Paul E.
2011-01-01
An extension of the traditional Kirkwood-Buff (KB) theory of solutions is outlined which provides additional fluctuating quantities that can be used to characterize and probe the behavior of solution mixtures. Particle-energy and energy-energy fluctuations for local regions of any multicomponent solution are expressed in terms of experimentally obtainable quantities, thereby supplementing the usual particle-particle fluctuations provided by the established KB inversion approach. The expressions are then used to analyze experimental data for pure water over a range of temperatures and pressures, a variety of pure liquids, and three binary solution mixtures – methanol and water, benzene and methanol, and aqueous sodium chloride. In addition to providing information on local properties of solutions it is argued that the particle-energy and energy-energy fluctuations can also be used to test and refine solute and solvent force fields for use in computer simulation studies. PMID:21806137
Special solutions to Chazy equation
NASA Astrophysics Data System (ADS)
Varin, V. P.
2017-02-01
We consider the classical Chazy equation, which is known to be integrable in hypergeometric functions. But this solution has remained purely existential and was never used numerically. We give explicit formulas for hypergeometric solutions in terms of initial data. A special solution was found in the upper half plane H with the same tessellation of H as that of the modular group. This allowed us to derive some new identities for the Eisenstein series. We constructed a special solution in the unit disk and gave an explicit description of singularities on its natural boundary. A global solution to Chazy equation in elliptic and theta functions was found that allows parametrization of an arbitrary solution to Chazy equation. The results have applications to analytic number theory.
Celestial mechanics solutions that escape
NASA Astrophysics Data System (ADS)
Gingold, Harry; Solomon, Daniel
2017-08-01
We establish the existence of an open set of initial conditions through which pass solutions without singularities to Newton's gravitational equations in R3 on a semi-infinite interval in forward time, for which every pair of particles separates like At , A > 0, as t → ∞. The solutions are constructable as series with rapid uniform convergence and their asymptotic behavior to any order is prescribed. We show that this family of solutions depends on 6N parameters subject to certain constraints.
Solute diffusion in liquid metals
NASA Technical Reports Server (NTRS)
Bhat, B. N.
1973-01-01
A gas model of diffusion in liquid metals is presented. In this model, ions of liquid metals are assumed to behave like the molecules in a dense gas. Diffusion coefficient of solute is discussed with reference to its mass, ionic size, and pair potential. The model is applied to the case of solute diffusion in liquid silver. An attempt was made to predict diffusion coefficients of solutes with reasonable accuracy.
Colligative properties of simple solutions.
Andrews, F C
1976-11-05
Vapor pressure lowering, osmotic pressure, boiling point elevation, and freezing point depression are all related quantitatively to the decrease in micro(1)(soln) upon the addition of solute in forming a solution. In any equilibrium system, regardless of whether it is in a gravitational field or whether it contains walls, semipermeable membranes, phase transitions, or solutes, all equilibria are maintained locally, in the small region of the equilibrium, by the equality of micro(1)(soln). If there are several subsystems in a gravitational field, at any fixed height, microi will have the same value in each subsystem into which substance i can get, and microi + M(i)gh is constant throughout the entire system. In a solution, there is no mechanism by which solvent and solute molecules could sustain different pressures. Both the solvent and solute are always under identical pressures in a region of solution, namely, the pressure of the solution in that region. Since nature does not know which component we call the solvent and which the solute, equations should be symmetric in the two (acknowledging that the nonvolatile component, if any, is commonly chosen to be solute). Simple molecular pictures illustrate what is happening to cause pressure (positive or negative) in liquids, vapor pressure of liquids, and the various colligative properties of solutions. The only effect of solute involved in these properties is that it dilutes the solvent, with the resulting increase in S and decrease in micro(1)(soln). Water can be driven passively up a tree to enormous heights by the difference between its chemical potential in the roots and the ambient air. There is nothing mysterious about the molecular bases for any of these phenomena. Biologists can use the well-understood pictures of these phenomena with confidence to study what is happening in the complicated living systems they consider.
Formulation and Stability of Solutions.
Akers, Michael J
2016-01-01
Ready-to-use solutions are the most preferable and most common dosage forms for injectable and topical ophthalmic products. Drugs formulated as solution almost always have chemical and physical stability challenges as well as solubility limitations and the need to prevent inadvertent microbial contamination issues. This article, which takes us through a discussion of optimizing the physical stability of solutions, represents the first of a series of articles discussing how these challenges and issues are addressed.
Larkin, K.A.
1994-08-14
This test plan describes the activities associated with the High Gradient Magnetic Filtration (HGMF) of plutonium-bearing solutions (10-L). The 10-L solutions were received from Argonne National Laboratories in 1972, are highly acidic, and are considered unstable. The purpose of the testing is to show that HGMF is an applicable method of removing plutonium precipitates from solution. The plutonium then can be stored safely in a solid form.
Decoupling solution moduli of bigravity
NASA Astrophysics Data System (ADS)
Yılmaz, Nejat Tevfik
2016-12-01
A complete classification of exact solutions of ghost-free, massive bigravity is derived which enables the dynamical decoupling of the background, and the foreground metrics. The general decoupling solution space of the two metrics is constructed. Within this branch of the solution space the foreground metric theory becomes general relativity (GR) with an additional effective cosmological constant, and the background metric dynamics is governed by plain GR.
A heuristic for suffix solutions
Bilgory, A.; Gajski, D.D.
1986-01-01
The suffix problem has appeared in solutions of recurrence systems for parallel and pipelined machines and more recently in the design of gate and silicon compilers. In this paper the authors present two algorithms. The first algorithm generates parallel suffix solutions with minimum cost for a given length, time delay, availability of initial values, and fanout. This algorithm generates a minimal solution for any length n and depth range log/sub 2/ N to N. The second algorithm reduces the size of the solutions generated by the first algorithm.
Mass action in ionic solutions
NASA Astrophysics Data System (ADS)
Eisenberg, Bob
2011-07-01
The law of mass action describes reactants as simple ideal fluids of concentrations of uncharged noninteracting particles. Ionic solutions contain interacting charged particles and are not ideal. Interactions of reactants can then be mistaken for complexities in chemical reactions or enzymatic catalysts. The variational theory of complex fluids describes flowing mixtures like biological solutions. When a component is added, the theory derives-by mathematics alone-a new set of differential equations that automatically captures all interactions. A variational theory of ionic solutions (as complex fluids) provides computable description of ions in solutions and proteins. Numerical inefficiencies have delayed experimental verification.
Molecular aggregates in cryogenic solutions
NASA Astrophysics Data System (ADS)
Schauer, M. W.; Lee, J.; Bernstein, E. R.
1981-07-01
In this report, experimental procedures and results concerning the study of aggregates are presented. Absorption spectra of solutions of the following solutes and solvents have been studied: pyrazine/C3H8; benzene/NF3, C3H8, N2, CO, CF4; and osmium tetroxide/NF3, CH4, C3H8. In order to obtain some qualitative estimation of aggregate size light scattering experiments were also performed on solutions of pyrazine/C3H8, benzene/CF4 benzene/NF3, and benzene/C3H8. The nature of these non-equilibrium molecular clusters in solution will be addressed.
Supercooling behavior in aqueous solutions.
Kimizuka, Norihito; Suzuki, Toru
2007-03-08
Using the emulsion method, we measured the homogeneous nucleation temperature depression, DeltaT(f,hom), and equilibrium melting points depression, DeltaT(m), of various aqueous solutions and then calculated lambda for each solute using the linear relationship DeltaT(f,hom) = lambdaDeltaT(m). We defined lambda as the solute-specific supercooling capacity and examined its correlation with some known hydration characteristics. The results showed that lambda is correlated with D0, the self-diffusion coefficient of solute molecules in infinite dilution.
Exact solutions to quadratic gravity
NASA Astrophysics Data System (ADS)
Pravda, V.; Pravdová, A.; Podolský, J.; Švarc, R.
2017-04-01
Since all Einstein spacetimes are vacuum solutions to quadratic gravity in four dimensions, in this paper we study various aspects of non-Einstein vacuum solutions to this theory. Most such known solutions are of traceless Ricci and Petrov type N with a constant Ricci scalar. Thus we assume the Ricci scalar to be constant which leads to a substantial simplification of the field equations. We prove that a vacuum solution to quadratic gravity with traceless Ricci tensor of type N and aligned Weyl tensor of any Petrov type is necessarily a Kundt spacetime. This will considerably simplify the search for new non-Einstein solutions. Similarly, a vacuum solution to quadratic gravity with traceless Ricci type III and aligned Weyl tensor of Petrov type II or more special is again necessarily a Kundt spacetime. Then we study the general role of conformal transformations in constructing vacuum solutions to quadratic gravity. We find that such solutions can be obtained by solving one nonlinear partial differential equation for a conformal factor on any Einstein spacetime or, more generally, on any background with vanishing Bach tensor. In particular, we show that all geometries conformal to Kundt are either Kundt or Robinson-Trautman, and we provide some explicit Kundt and Robinson-Trautman solutions to quadratic gravity by solving the above mentioned equation on certain Kundt backgrounds.
Exact analytical solutions for ADAFs
NASA Astrophysics Data System (ADS)
Habibi, Asiyeh; Abbassi, Shahram; Shadmehri, Mohsen
2017-02-01
We obtain two-dimensional exact analytic solutions for the structure of the hot accretion flows without wind. We assume that the only non-zero component of the stress tensor is Trϕ. Furthermore, we assume that the value of viscosity coefficient α varies with θ. We find radially self-similar solutions and compare them with the numerical and the analytical solutions already studied in the literature. The no-wind solution obtained in this paper may be applied to the nuclei of some cool-core clusters.
Extraordinary vacuum black string solutions
Kim, Hyeong-Chan; Lee, Jungjai
2008-01-15
In addition to the boosted static solution there are two other classes of stationary stringlike solutions of the vacuum Einstein equation in (4+1) dimensions. Each class is characterized by three parameters of mass, tension, and momentum flow along the fifth coordinate. We analyze the metric properties of one of the two classes, which was previously assumed to be naked singular, and show that the solution spectrum contains black string and wormhole in addition to the known naked singularity as the momentum flow to mass ratio increases. Interestingly, there does not exist new zero momentum solution in these cases.
High conductivity electrolyte solutions and rechargeable cells incorporating such solutions
Angell, Charles Austen; Zhang, Sheng-Shui; Xu, Kang
1998-01-01
This invention relates generally to electrolyte solvents for use in liquid or rubbery polymer electrolyte solutions as are used, for example, in electrochemical devices. More specifically, this invention relates to sulfonyl/phospho-compound electrolyte solvents and sulfonyl/phospho-compound electrolyte solutions incorporating such solvents.
High conductivity electrolyte solutions and rechargeable cells incorporating such solutions
Angell, C.A.; Zhang, S.S.; Xu, K.
1998-10-20
This invention relates generally to electrolyte solvents for use in liquid or rubbery polymer electrolyte solutions as are used, for example, in electrochemical devices. More specifically, this invention relates to sulfonyl/phospho-compound electrolyte solvents and sulfonyl/phospho-compound electrolyte solutions incorporating such solvents. 9 figs.
Interior Design: Challenges and Solutions.
ERIC Educational Resources Information Center
School Planning and Management, 1999
1999-01-01
Presents solutions to architectural challenges in school interior design; these solutions made the indoor environments more conducive and attractive for learning. Addresses four challenges: making a long corridor look less like a tunnel; maintaining tradition and minimizing cost in a new athletic facility; designing a kindergarten that is secure…
ERIC Educational Resources Information Center
Tennant, Roy
2004-01-01
Small solutions solve discrete, well-bounded problems and can be pieces of larger solutions. They can move things forward by mixing and matching available components in new and previously unimagined ways. A number of innovations, which at first glance are completely unrelated, can come together and create important synergics. This article…
Interior Design: Challenges and Solutions.
ERIC Educational Resources Information Center
School Planning and Management, 1999
1999-01-01
Presents solutions to architectural challenges in school interior design; these solutions made the indoor environments more conducive and attractive for learning. Addresses four challenges: making a long corridor look less like a tunnel; maintaining tradition and minimizing cost in a new athletic facility; designing a kindergarten that is secure…
ERIC Educational Resources Information Center
Tennant, Roy
2004-01-01
Small solutions solve discrete, well-bounded problems and can be pieces of larger solutions. They can move things forward by mixing and matching available components in new and previously unimagined ways. A number of innovations, which at first glance are completely unrelated, can come together and create important synergics. This article…
Evaluation of ITRF2014 Solutions
NASA Astrophysics Data System (ADS)
Dach, Rolf; Grahsl, Andrea; Susnik, Andreja; Villiger, Arturo; Arnold, Daniel; Jäggi, Adrian
2017-04-01
For the most recent International Terrestrial Reference Frame (ITRF) realization three candidates have been provided, namely an ITRF2014 solution by IGN, DTRF2014 by DGFI-TUM, and JTRF2014 by JPL. There are significant differences in the way how these solutions have been generated, which parametrization has been applied, and how the solutions from the different space-geodetic techniques are combined. The most recent GNSS reprocessing solution generated in the frame of the EGSIEM project (European Gravity Service for Improved Emergency Management; funded by EC in the frame of Horizon 2020) was used to generate time series of GNSS-based solutions from 2000 to the end of 2014 using these reference frame realizations. The solution contains station coordinates, GNSS satellite orbits, Earth rotation parameters, and troposphere parameters. In order to evaluate the consistency of the contributions from the IGS (GNSS) and ILRS (SLR) in the reference frame solutions, the SLR measurements to the GNSS satellites can be used. Since the microwave-based GNSS satellite orbits obtained in the different reference frames are consistent regarding the orbit modeling differences in the SLR residuals may be interpreted to assess the consistency of the station coordinates between the SLR and GNSS sites in the reference frame solutions. With this contribution we hope to provide an independent contribution to the discussion about the advantages and disadvantages of the different methods to generate the IERS-TRF.
TREATMENT OF AMMONIUM NITRATE SOLUTIONS
Boyer, T.W.; MacHutchin, J.G.; Yaffe, L.
1958-06-10
The treatment of waste solutions obtained in the processing of neutron- irradiated uranium containing fission products and ammonium nitrate is described. The object of this process is to provide a method whereby the ammonium nitrate is destroyed and removed from the solution so as to permit subsequent concentration of the solution.. In accordance with the process the residual nitrate solutions are treated with an excess of alkyl acid anhydride, such as acetic anhydride. Preferably, the residual nitrate solution is added to an excess of the acetic anhydride at such a rate that external heat is not required. The result of this operation is that the ammonium nitrate and acetic anhydride react to form N/sub 2/ O and acetic acid.
Ion segregation in aqueous solutions.
Bian, Hongtao; Li, Jiebo; Zhang, Qiang; Chen, Hailong; Zhuang, Wei; Gao, Yi Qin; Zheng, Junrong
2012-12-13
Microscopic structures and dynamics of aqueous salt solutions were investigated with the ultrafast vibrational energy exchange method and anisotropy measurements. In KSCN aqueous solutions of various concentrations, the rotational time constants of SCN(-) anions are proportional to the viscosities of the solutions. However, the reorientation dynamics of the water molecules are only slightly affected by the solution viscosity. With the addition of strongly hydrated F(-) anions, the rotations of both SCN(-) anions and water molecules slow down. With the addition of weakly hydrated I(-) anions, only the rotation of SCN(-) anions slows down with that of water molecules unaffected. Vibrational energy exchange measurements show that the separation among SCN(-) anions decreases with the addition of F(-) and increases with the addition of I(-). The series of experiments clearly demonstrate that both structures and dynamics of ion and water are segregated in the strong electrolyte aqueous solutions.
Mycobactericidal activity of glutaraldehyde solutions.
Collins, F M; Montalbine, V
1976-01-01
Aqueous solutions of alkaline glutaraldehyde (buffered at pH 8.5) inactivated a standard suspension of Mycobacterium tuberculosis H37Rv faster than the corresponding acid (pH 3.7 preparation. Quantitative differences in the rate of inactivation of eight other species of Mycobacterium were determined using a 1% solution of alkaline glutaraldehyde and inactivation of residual glutaraldehyde with 1% sodium bisulfite solution. Variations in the rate of kill were observed between the various mycobacterial species tested, but such differences were probably not sufficiently large to be of practical importance. A 2% alkaline glutaraldehyde solution inactivated 10(5) viable M. tuberculosis cells present on the surface of porcelain penicylinders within 5 min at 18 degrees C. This rate of inactivation was faster than in the acidic solution. PMID:11227
Uremic solutes from colon microbes.
Meyer, Timothy W; Hostetter, Thomas H
2012-05-01
There is renewed interest in identifying organic waste solutes that are normally excreted by the kidneys and must be removed by renal replacement therapy when the kidneys fail. A large number of these waste solutes are produced by colon microbes. Mass spectrometry is expanding our knowledge of their chemical identity, and DNA sequencing technologies are providing new knowledge of the microbes and metabolic pathways by which they are made. There is evidence that the most extensively studied of the colon-derived solutes, indoxyl sulfate and p-cresol sulfate, are toxic. Much more study is required to establish the toxicity of other solutes in this class. Because they are made in an isolated compartment by microbes, their production may prove simpler to suppress than the production of other waste solutes. To the extent that they are toxic, suppressing their production could improve the health of renal failure patients without the need for more intensive or prolonged dialysis.
Multigrid solution of internal flows using unstructured solution adaptive meshes
NASA Technical Reports Server (NTRS)
Smith, Wayne A.; Blake, Kenneth R.
1992-01-01
This is the final report of the NASA Lewis SBIR Phase 2 Contract Number NAS3-25785, Multigrid Solution of Internal Flows Using Unstructured Solution Adaptive Meshes. The objective of this project, as described in the Statement of Work, is to develop and deliver to NASA a general three-dimensional Navier-Stokes code using unstructured solution-adaptive meshes for accuracy and multigrid techniques for convergence acceleration. The code will primarily be applied, but not necessarily limited, to high speed internal flows in turbomachinery.
[Platelet-washing solution optimization].
Grossin, E; Chamfly, V
2005-10-01
Different washing and homogénéisation solutions are hereby analysed by comparing the evolution of functional indicators during the preservation of washed aphaeresis platelet concentrates: physiological pH 4.5 and 6 solutions, buffered physiological pH 6.8 glucose solution, and two physiological pH 7 citrate solutions with acetate. Prior acidification of platelet concentrates proved to be essential. Two washings with manual or automated technique, guarantee residual proteins at a level of less than 0.5 g. Solutions T-Sol Baxter or SSP Macopharma allow us to obtain a product that meet the PSL specifications. Routine since June 2004, washings are done with a physiological pH 6 solution, then homogeneised with T-Sol solution. Platelet recovery, swirling phenomenon, lack of agrgegates, pH maintenance, low increase in the platelet average volume and maintenance of intra-cell potassium level, suggest that platelet entirety is preserved beyond the product's expiration date. The platelet transfusion yield of these products is satisfactory.
Solute clustering and interfacial tension
NASA Astrophysics Data System (ADS)
Larson, M. A.; Garside, John
1986-07-01
The effect of surface curvature on surface tension has been included in the theory of homogeneous nucleation to show that, under certain conditions, cluster formation results in a decrease in Gibb's free energy. This cluster formation is thus a spontaneous event and a quasi-equilibrium concentration of clusters of narrow size range may then exist in supersaturated solutions. Previous experimental work suggests the existence of solute clusters in a variety of aqueous solutions. The implications for crystal nucleation and growth theory are discussed.
CESIUM RECOVERY FROM AQUEOUS SOLUTIONS
Schneider, R.A.
1961-06-20
Cesium may be precipitated from an aqueous solution whose acidity ranges between a pH of 1.5 and a molarity of 5 on cobaltous, zinc, cadmium, nickel, or ferrous cobalticyanide. This precipitation brings about a separation from most fission products. Ruthenium which coprecipitates to a great degree can be removed by dissolving in sulfuric acid and boiling the solution in the presence of periodic acid for volatilization; other coprecipitated fission products can then be precipitated from the sulfuric acid solution with a ferric hydroxide carrier.
Inverse problem solution in ellipsometry
NASA Astrophysics Data System (ADS)
Zabashta, Lubov A.; Zabashta, Oleg I.
1995-11-01
Interactive graphic system 'ELLA' is described which is an integrated program packet for reverse problem solution in ellipsometry. The solutions stable to experimental errors are found by two algorithms: a simplex method under constraints and a regularizing iteration method. A developed graphic procedure kit includes display of graphic surface layers, their optical parameters, and all main results of intermediate calculations. Specialized graphic input functions allow us to change the parameters of a chosen solution method, the basic data, to enter new additional information, etc. On the examples of model structure of GaAs-oxide MAI capabilities in ellipsometry for determination of multilayer structure optical parameters are studied.
Formulation and Stability of Solutions.
Akers, Michael J
2016-01-01
Ready-to-use solutions are the most preferable and most common dosage forms for injectable and topical ophthalmic products. Drugs formulated as solution almost always have chemical and physical stability challenges as well as solubility limitations and the need to prevent inadvertent microbial contamination issues. The first in this series of articles took us through a discussion of optimizing the physical stability of solutions. This article concludes this series of articles with a discussion on foreign particles, protein aggregation, and immunogenicity; optimizing microbiological activity; and osmolality (tonicity) agents, and discusses how these challenges and issues are addressed.
Periodontal ligament injection: alternative solutions.
Gray, R. J.; Lomax, A. M.; Rood, J. P.
1990-01-01
This study was undertaken to investigate whether plain lidocaine, 3% plain mepivacaine and 3% prilocaine with felypressin were suitable epinephrine-free local anesthetic solutions for use in periodontal ligament anesthesia as alternatives to lidocaine with 1:80,000 epinephrine. Two hundred and seven patients received one of the four test solutions via a periodontal ligament injection and the success rate of anesthesia was confirmed using an electric pulp stimulator. Although neither mepivacaine nor prilocaine were as effective as lidocaine with epinephrine, the success rates of these three solutions were not statistically different. A single periodontal ligament injection of any of the solutions tested resulted in a low incidence of anesthesia. The success rate of lidocaine without epinephrine was consistently poor. PMID:2097910
Clean Energy Solutions Center Services
2016-03-01
The Solutions Center offers no-cost expert policy assistance, webinars and training forums, clean energy policy reports, data, and tools provided in partnership with more than 35 leading international and regional clean energy organizations.
Preparation of Simulated Waste Solutions
Walker, D.D.
1999-06-08
Waste Processing Technology personnel routinely prepare 0.5 to 10 L batches of salt solutions simulating Savannah River Site (SRS) soluble waste. This report describes the compositions and preparation methods.
Cosmological solution moduli of bigravity
Yılmaz, Nejat Tevfik
2015-09-29
We construct the complete set of metric-configuration solutions of the ghost-free massive bigravity for the scenario in which the g−metric is the Friedmann-Lemaitre-Robertson-Walker (FLRW) one, and the interaction Lagrangian between the two metrics contributes an effective ideal fluid energy-momentum tensor to the g-metric equations. This set corresponds to the exact background cosmological solution space of the theory.
Cesium recovery from aqueous solutions
Goodhall, C. A.
1960-09-13
A process for recovering cesium from aqueous solutions is given in which precipitation on zinc ferricyanide is used. The precipitation is preferably carried out in solutions containing at least 0.0004M zinc ferricyanide, an acidity ranging from 0.2N mineral acid to 0.61N acid deficiency, and 1 to 2.5M aluminum nitrate. (D.L.C.)
Cosmological solution moduli of bigravity
Yılmaz, Nejat Tevfik
2015-09-01
We construct the complete set of metric-configuration solutions of the ghost-free massive bigravity for the scenario in which the g−metric is the Friedmann-Lemaitre-Robertson-Walker (FLRW) one, and the interaction Lagrangian between the two metrics contributes an effective ideal fluid energy-momentum tensor to the g-metric equations. This set corresponds to the exact background cosmological solution space of the theory.
Comprehensive Water-Efficiency Solutions
McMordie Stoughton, Kate
2015-07-15
Energy performance contracts can be an effective way to integrate comprehensive water-efficient technologies and solutions into energy efficiency projects. Current practices often miss key opportunities to incorporate a full suite of water measures primarily because a comprehensive approach is not taken in the assessment. This article provides information on how to develop a comprehensive water project that leads to innovative solutions and potential for large water reduction.
Weder, R.
1982-05-15
We prove the nonexistence of finite-energy Julia-Zee dyon solutions, in the Bogomol'ny-Prosad-Sommerfield limit, and the generalizations to SU(N) gauge groups, with the same asymptotic value for the Higgs field and the time component of the gauge field. This gives a physically relevant example showing how the topological arguments can fail to provide the existence of a solution in the presence of a nontrivial topological charge.
Nonequilibrium thermodynamics of pressure solution
NASA Astrophysics Data System (ADS)
Lehner, F. K.; Bataille, J.
1984-01-01
This paper is concerned with the thermodynamic theory of solution and precipitation processes in wet crustal rocks and with the mechanism of steady pressure-solution slip in ‘contact zones,’ such as grain-to-grain contacts, fracture surfaces, and permeable gouge layers, that are infiltrated by a mobile aqueous solution phase. A local dissipation jump condition at the phase boundary is fundamental to identifying the thermodynamic force driving the solution and precipitation process and is used here in setting up linear phenomenological relations to model near-equilibrium phase transformation kinetics. The local thermodynamic equilibrium of a stressed pure solid in contact with its melt or solution phase is governed by Gibbs's relation, which is rederived here, in a manner emphasizing its independence of constitutive assumptions for the solid while neglecting surface tension and diffusion in the solid. Fluid-infiltrated contact zones, such as those formed by rough surfaces, cannot generally be in thermodynamic equilibrium, especially during an ongoing process of pressure-solution slip, and the existing equilibrium formulations are incorrect in overlooking dissipative processes tending to eliminate fluctuations in superficial free energies due to stress concentrations near asperities, defects, or impurities. Steady pressure-solution slip is likely to exhibit a nonlinear dependence of slip rate on shear stress and effective normal stress, due to a dependence of the contact-zone state on the latter. Given that this dependence is negligible within some range, linear relations for pressure-solution slip can be derived for the limiting cases of diffusion-controlled and interface-reaction-controlled rates. A criterion for rate control by one of these mechanisms is set by the magnitude of the dimensionless quantity kδ/2C pD, where k is the interfacial transfer coefficient, δ is the mean diffusion path length, C p is the solubility at pressure p, and D is the mass
Reuse of hydroponic waste solution.
Kumar, Ramasamy Rajesh; Cho, Jae Young
2014-01-01
Attaining sustainable agriculture is a key goal in many parts of the world. The increased environmental awareness and the ongoing attempts to execute agricultural practices that are economically feasible and environmentally safe promote the use of hydroponic cultivation. Hydroponics is a technology for growing plants in nutrient solutions with or without the use of artificial medium to provide mechanical support. Major problems for hydroponic cultivation are higher operational cost and the causing of pollution due to discharge of waste nutrient solution. The nutrient effluent released into the environment can have negative impacts on the surrounding ecosystems as well as the potential to contaminate the groundwater utilized by humans for drinking purposes. The reuse of non-recycled, nutrient-rich hydroponic waste solution for growing plants in greenhouses is the possible way to control environmental pollution. Many researchers have successfully grown several plant species in hydroponic waste solution with high yield. Hence, this review addresses the problems associated with the release of hydroponic waste solution into the environment and possible reuse of hydroponic waste solution as an alternative resource for agriculture development and to control environmental pollution.
Crystallization of supercooled solutions. [atmosphere
NASA Technical Reports Server (NTRS)
Harrison, K.; Hallett, John
1988-01-01
Crystallization of uniformly supercooled solutions (Na2SO4, NaCl, H2SO4, HNO3, HCl) was studied. It is shown how crystal growth velocity and habit depend on solution and concentration. The segregation coefficient for the solute in ice is measured by analysis of ice and solution, separated immediately after initial freezing, at different supercoolings. Subsequent solidification gives ion rejection at a varying rate depending on the geometry of the freezing, and may result in separation of hydrates, particularly when the initial concentration is high, as in haze (inactivated) droplets and low temperatures found in the Antarctic stratosphere. Electrical effects associated with rapid freezing are also investigated. Results suggest that more extensive measurements need to be made in solutions at different supercoolings, and that substantial electrical effects may be present for higher concentrations under these conditions. Damage to vegetation could occur under specific conditions as concentrated solutions (possibly H2SO4) are rejected in the freezing of rime or dew.
Crystallization of supercooled solutions. [atmosphere
NASA Technical Reports Server (NTRS)
Harrison, K.; Hallett, John
1988-01-01
Crystallization of uniformly supercooled solutions (Na2SO4, NaCl, H2SO4, HNO3, HCl) was studied. It is shown how crystal growth velocity and habit depend on solution and concentration. The segregation coefficient for the solute in ice is measured by analysis of ice and solution, separated immediately after initial freezing, at different supercoolings. Subsequent solidification gives ion rejection at a varying rate depending on the geometry of the freezing, and may result in separation of hydrates, particularly when the initial concentration is high, as in haze (inactivated) droplets and low temperatures found in the Antarctic stratosphere. Electrical effects associated with rapid freezing are also investigated. Results suggest that more extensive measurements need to be made in solutions at different supercoolings, and that substantial electrical effects may be present for higher concentrations under these conditions. Damage to vegetation could occur under specific conditions as concentrated solutions (possibly H2SO4) are rejected in the freezing of rime or dew.
Hardness of cubic solid solutions
Gao, Faming
2017-01-01
We demonstrate that a hardening rule exists in cubic solid solutions with various combinations of ionic, covalent and metallic bonding. It is revealed that the hardening stress ∆τFcg is determined by three factors: shear modulus G, the volume fraction of solute atoms fv, and the size misfit degree δb. A simple hardening correlation in KCl-KBr solid-solution is proposed as ∆τFcg = 0.27 G. It is applied to calculate the hardening behavior of the Ag-Au, KCl-KBr, InP-GaP, TiN-TiC, HfN-HfC, TiC-NbC and ZrC-NbC solid-solution systems. The composition dependence of hardness is elucidated quantitatively. The BN-BP solid-solution system is quantitatively predicted. We find a hardening plateau region around the x = 0.55–0.85 in BNxP1−x, where BNxP1−x solid solutions are far harder than cubic BN. Because the prediction is quantitative, it sets the stage for a broad range of applications. PMID:28054659
Hardness of cubic solid solutions
NASA Astrophysics Data System (ADS)
Gao, Faming
2017-01-01
We demonstrate that a hardening rule exists in cubic solid solutions with various combinations of ionic, covalent and metallic bonding. It is revealed that the hardening stress ∆τFcg is determined by three factors: shear modulus G, the volume fraction of solute atoms fv, and the size misfit degree δb. A simple hardening correlation in KCl-KBr solid-solution is proposed as ∆τFcg = 0.27 G. It is applied to calculate the hardening behavior of the Ag-Au, KCl-KBr, InP-GaP, TiN-TiC, HfN-HfC, TiC-NbC and ZrC-NbC solid-solution systems. The composition dependence of hardness is elucidated quantitatively. The BN-BP solid-solution system is quantitatively predicted. We find a hardening plateau region around the x = 0.55-0.85 in BNxP1-x, where BNxP1-x solid solutions are far harder than cubic BN. Because the prediction is quantitative, it sets the stage for a broad range of applications.
Transperitoneal solute movement in children.
Gruskin, A B; Rosenblum, H; Baluarte, H J; Morgenstern, B Z; Polinsky, M S; Perlman, S A
1983-11-01
The transperitoneal movement of solute in children was examined by means of a theoretical consideration of the peritoneal clearance formula and by the performance of peritoneal solute diffusion curves and measurement of peritoneal clearances of multiple solutes. Theoretical considerations led to the conclusion that when dialysis mechanics are held constant, peritoneal clearances scaled for weight are similar in individuals of widely varying weight when the volume of infused dialysate is also scaled for weight if peritoneal permeability and surface area are constant. In one group of studies, solute diffusion curves and weight-scaled peritoneal clearances of urea, phosphate, creatinine, and urate were similar in 3 children ages 4 to 18 months compared to 4 children ages 2.5 to 18.5 years. In a second group of studies, weight-scaled peritoneal clearances of inulin but not urea were shown to be marginally lower in 4 children who had been dialyzed longer than 6 months compared with 4 children dialyzed less than 1 month. Hypertonic glucose dialysis in these children was shown to enhance urea clearance but not that of inulin. It is concluded that comparative studies of peritoneal clearances can characterize the transperitoneal movement of solute in children of widely varying body size. Such studies are of greatest value when systematically performed and similar ratios of dialysate volumes to body pools of solute are used.
Technetium recovery from high alkaline solution
Nash, Charles A.
2016-07-12
Disclosed are methods for recovering technetium from a highly alkaline solution. The highly alkaline solution can be a liquid waste solution from a nuclear waste processing system. Methods can include combining the solution with a reductant capable of reducing technetium at the high pH of the solution and adding to or forming in the solution an adsorbent capable of adsorbing the precipitated technetium at the high pH of the solution.
Zielinski, Michal W; McGann, Locksley E; Nychka, John A; Elliott, Janet A W
2014-10-01
Thermodynamic solution theories allow the prediction of chemical potentials in solutions of known composition. In cryobiology, such models are a critical component of many mathematical models that are used to simulate the biophysical processes occurring in cells and tissues during cryopreservation. A number of solution theories, both thermodynamically ideal and non-ideal, have been proposed for use with cryobiological solutions. In this work, we have evaluated two non-ideal solution theories for predicting water chemical potential (i.e. osmolality) in multi-solute solutions relevant to cryobiology: the Elliott et al. form of the multi-solute osmotic virial equation, and the Kleinhans and Mazur freezing point summation model. These two solution theories require fitting to only single-solute data, although they can make predictions in multi-solute solutions. The predictions of these non-ideal solution theories were compared to predictions made using ideal dilute assumptions and to available literature multi-solute experimental osmometric data. A single, consistent set of literature single-solute solution data was used to fit for the required solute-specific coefficients for each of the non-ideal models. Our results indicate that the two non-ideal solution theories have similar overall performance, and both give more accurate predictions than ideal models. These results can be used to select between the non-ideal models for a specific multi-solute solution, and the updated coefficients provided in this work can be used to make the desired predictions.
Stability of tacrolimus ophthalmic solution.
Ezquer-Garin, Carlos; Ferriols-Lisart, Rafael; Alós-Almiñana, Manuel
2017-07-01
The stability of 0.3-mg/mL tacrolimus ophthalmic solution at different storage temperatures was studied. A sterile ophthalmic solution of 0.3 mg/mL tacrolimus was prepared in triplicate under aseptic conditions by diluting tacrolimus in eye drops. Three aliquots of this solution were transferred into polypropylene bottles and stored at 25, 2-8, or -15 to -25 °C. Samples were collected immediately after preparation and at selected time points and assayed in triplicate using high-performance liquid chromatography (HPLC). Samples were also visually examined for macroscopic changes. The 0.3-mg/mL tacrolimus solution was also exposed to acidic treatment and heat to force its degradation and to evaluate the selectivity of the analytic method. The tacrolimus ophthalmic solution was considered stable if at least 90% of the mean initial concentration remained when analyzed by HPLC. When stored at 2-8 °C and between -15 and -25 °C, at least 90% of the initial tacrolimus concentration remained throughout the 85-day study period. There were no significant differences in tacrolimus concentrations between the starting and ending points (p > 0.05). However, when tacrolimus solution was stored at 25 °C, the percentage of the initial tacrolimus concentration remaining had decreased to less than 90% on day 28. Tacrolimus diluted to 0.3 mg/mL in eye drop solution was stable for 20 days when stored at 25 °C and for at least 85 days when stored at 2-8 °C or between -15 and -25 °C in polypropylene bottles and protected from light. Copyright © 2017 by the American Society of Health-System Pharmacists, Inc. All rights reserved.
STRUCTURE AND PROPERTIES OF SOLID SOLUTIONS.
Contents: solid solution strengthening and strain aging in Ag-base Al alloys; solid solution strengthening and aging in Cu-base Al alloys; solid ... solution strengthening in NaCl-base NaBr solutions; short-range order; solid solution strength in the gold-silver system.
Acidity of frozen electrolyte solutions.
Robinson, Carmen; Boxe, C S; Guzman, M I; Colussi, A J; Hoffmann, M R
2006-04-20
Ice is selectively intolerant to impurities. A preponderance of implanted anions or cations generates electrical imbalances in ice grown from electrolyte solutions. Since the excess charges are ultimately neutralized via interfacial (H(+)/HO(-)) transport, the acidity of the unfrozen portion can change significantly and permanently. This insufficiently recognized phenomenon should critically affect rates and equilibria in frozen media. Here we report the effective (19)F NMR chemical shift of 3-fluorobenzoic acid as in situ probe of the acidity of extensively frozen electrolyte solutions. The sign and magnitude of the acidity changes associated with freezing are largely determined by specific ion combinations, but depend also on solute concentration and/or the extent of supercooling. NaCl solutions become more basic, those of (NH(4))(2)SO(4) or Na(2)SO(4) become more acidic, while solutions of the 2-(N-morpholino)ethanesulfonic acid zwitterion barely change their acidity upon freezing. We discuss how acidity scales based on solid-state NMR measurements could be used to assess the degree of ionization of weak acids and bases in frozen media.
Nucleation of Crystals in Solution
NASA Astrophysics Data System (ADS)
Vekilov, Peter G.
2010-07-01
Solution crystallization is an essential part of processes in the chemical and pharmaceutical industries and a major step in physiological and pathological phenomena. Crystallization starts with nucleation and control of nucleation is crucial for the control of the number, size, perfection, polymorphism and other characteristics of the crystalline materials. Recently, there have been significant advances in the understanding of the mechanism of nucleation of crystals in solution. The most significant of these is the two-step mechanism of nucleation, according to which the crystalline nucleus appears inside pre-existing metastable clusters of size several hundred nanometers, which consist of dense liquid and are suspended in the solution. While initially proposed for protein crystals, the applicability of this mechanism has been demonstrated for small molecule organic materials, colloids, and biominerals. This mechanism helps to explain several long-standing puzzles of crystal nucleation in solution: nucleation rates which are many orders of magnitude lower than theoretical predictions, nucleation kinetic dependencies with steady or receding parts at increasing supersaturation, the role of heterogeneous substrates for polymorph selection, the significance of the dense protein liquid, and others. More importantly, this mechanism provides powerful tools for control of the nucleation process by varying the solution thermodynamic parameters so that the volume occupied by the dense liquid shrinks or expands.
Stability of aflatoxins in solution.
Diaz, Gonzalo J; Cepeda, Sandra M; Martos, Perry A
2012-01-01
The stability of aflatoxins B1, B2, G1, and G2 was studied in solutions containing different concentrations of water, acetonitrile, and/or methanol, and in autosampler vials treated with nitric acid or silanized. When stored at room temperature (20 degrees C) for 24 h, aflatoxins G1 and G2 were stable only in solutions containing 100% organic solvent, whereas aflatoxins B1 and B2 were stable in solutions of methanol-water and acetonitrile-water at greater than 60 and 40% organic content, respectively. At 5 degrees C, aflatoxins G1 and G2 showed a significant decrease in concentration only when kept in less than 20% aqueous organic solvent. Significant loss of aflatoxins was realized in standard, commercially available amber type I borosilicate autosampler vials, but chemical etching of the vials with nitric acid or with silanization prevented aflatoxin degradation. These results indicate that aflatoxins are unstable in aqueous solutions and that this instability can be counteracted by the presence of at least 20% organic solvent and keeping the solutions at 5 degrees C or by the use of treated vials.
Protein aggregation in salt solutions
Kastelic, Miha; Kalyuzhnyi, Yurij V.; Hribar-Lee, Barbara; Dill, Ken A.; Vlachy, Vojko
2015-01-01
Protein aggregation is broadly important in diseases and in formulations of biological drugs. Here, we develop a theoretical model for reversible protein–protein aggregation in salt solutions. We treat proteins as hard spheres having square-well-energy binding sites, using Wertheim’s thermodynamic perturbation theory. The necessary condition required for such modeling to be realistic is that proteins in solution during the experiment remain in their compact form. Within this limitation our model gives accurate liquid–liquid coexistence curves for lysozyme and γ IIIa-crystallin solutions in respective buffers. It provides good fits to the cloud-point curves of lysozyme in buffer–salt mixtures as a function of the type and concentration of salt. It than predicts full coexistence curves, osmotic compressibilities, and second virial coefficients under such conditions. This treatment may also be relevant to protein crystallization. PMID:25964322
Silicon oxidation in fluoride solutions
NASA Technical Reports Server (NTRS)
Sancier, K. M.; Kapur, V.
1980-01-01
Silicon is produced in a NaF, Na2SiF6, and Na matrix when SiF4 is reduced by metallic sodium. Hydrogen is evolved during acid leaching to separate the silicon from the accompanying reaction products, NaF and Na2SiF6. The hydrogen evolution reaction was studied under conditions simulating leaching conditions by making suspensions of the dry silicon powder in aqueous fluoride solutions. The mechanism for the hydrogen evolution is discussed in terms of spontaneous oxidation of silicon resulting from the cooperative effects of (1) elemental sodium in the silicon that reacts with water to remove a protective silica layer, leaving clean reactive silicon, and (2) fluoride in solution that complexes with the oxidized silicon in solution and retards formation of a protective hydrous oxide gel.
Plagiarism Detection by Online Solutions.
Masic, Izet; Begic, Edin; Dobraca, Amra
2017-01-01
The problem of plagiarism represents one of the burning issues of the modern scientific world. Detection of plagiarism is a problem that the Editorial Board encounters in their daily work. Software solutions represent a good solution for the detection of plagiarism. The problem of plagiarism will become most discussed topic of the modern scientific world, especially due to the development of standard measures, which rank the work of one author. Investment in education, education of young research personnel about the importance of scientific research, with paying particular attention on ethical behavior, becomes an imperative of academic staff. Editors have to invest additional effort in the development of the base of reviewers team as well as in their proper guidance, because after all, despite the software solutions, they are the best weapon to fight plagiarism. Peer review process should be a key of successful operation of each journal.
Recent Mascon Solutions from GRACE
NASA Technical Reports Server (NTRS)
Yuan, Dah-Ning; Watkins, M. M.
2006-01-01
Mascon (mass concentration) solutions computed for entire land area of Earth with several variants from Jul. 2003 through Dec. 2005 Automated scripts developed, "pipeline" now in place. Solutions generally consistent with harmonics for large features but appear able to resolve and localize smaller features more cleanly. Greenland solutions generally consistent with areas of max ice mass loss in South, but mascons seem to clearly identify sub-regions of ice mass growth. May be amplified by mascon sensitivity and ground tracks. Irregular coverage, errors due to tides in Arctic or other leakage from nearby sources? Although mascons are technically 30+ years old, gravity/geodesy community has vastly more experience with harmonics and thus we are still learning the full advantages, limitations, and idiosyncrasies of mascons.
A tire contact solution technique
NASA Technical Reports Server (NTRS)
Tielking, J. T.
1983-01-01
An efficient method for calculating the contact boundary and interfacial pressure distribution was developed. This solution technique utilizes the discrete Fourier transform to establish an influence coefficient matrix for the portion of the pressurized tire surface that may be in the contact region. This matrix is used in a linear algebra algorithm to determine the contact boundary and the array of forces within the boundary that are necessary to hold the tire in equilibrium against a specified contact surface. The algorithm also determines the normal and tangential displacements of those points on the tire surface that are included in the influence coefficient matrix. Displacements within and outside the contact region are calculated. The solution technique is implemented with a finite-element tire model that is based on orthotropic, nonlinear shell of revolution elements which can respond to nonaxisymmetric loads. A sample contact solution is presented.
Demonstration of FRET in solutions
NASA Astrophysics Data System (ADS)
Shah, Sunil; Gryczynski, Zygmunt; Chib, Rahul; Fudala, Rafal; Baxi, Aatmun; Borejdo, Julian; Synak, Anna; Gryczynski, Ignacy
2016-03-01
We measured the Förster resonance energy transfer (FRET) from Uranin (U) donor to Rhodamine 101 (R101) acceptor in propylene glycol. Steady-state fluorescence measurements show a significant difference between mixed and unmixed fluorophore solutions. In the solution with mixed fluorophores, fluorescence intensity of the U donor decreases and intensity of R101 fluorescence increases. This is visualized as a color change from green to orange. Fluorescence anisotropy of the mixture solution increases in the donor emission wavelength region and decreases in the acceptor emission wavelengths; which is consistent with FRET occurrence. Time-resolved (lifetime) measurements show a decrease of the U lifetime in the presence of R101 acceptor. In the intensity decay of R101 acceptor appears a negative component indicating excited state process. All these measurements prove the presence of FRET in U/R101 mixture fluorescence.
Ln polyoxocations: yttrium oxide solution speciation & solution deposited thin films.
Marsh, David A; Goberna-Ferrón, Sara; Baumeister, Mary K; Zakharov, Lev N; Nyman, May; Johnson, Darren W
2017-01-17
Rare earth oxide materials, including thin film coatings, are critically important in magnetic, luminescent and microelectric devices, and few substitutes have been discovered with comparable performance. Thin film coatings from solution are almost unknown for rare earth oxides, likely due to their high activity towards hydrolysis which yields poor quality thin films. The hexamer [Ln6(O)(OH)8(H2O)12(NO3)6](2+) is a rare example of a metal-oxo cluster isolated and stabilized without additional supporting organic ligands. Herein we report a new method for both the preparation and stabilization in non-aqueous media, which makes these clusters valuable precursors for solution-processed thin films. Solution characterization (NMR, small-angle X-ray scattering and Raman spectroscopy) in wet organic solvents indicated that the clusters evolve via a fragmentation and reaggregation process. This is especially true for hexamers of the smaller Ln(3+)-ions: the higher charge density yields higher hydration rates. This process produced an entirely new hexadecameric cluster formulated Y16O3(OH)24(NO3)18(OSMe2)16(OCMe2)2(H2O)4. The new structure represents an intermediate hydrolysis product on the pathway from hexanuclear clusters to metal oxyhydroxide bulk solid. DMSO solvent ligands displace aqua ligands on the cluster and likely explain the additional stability observed for these clusters in organic solvents. The enhanced cluster stability in DMF and DMSO also enables solution-processing methods to create high quality thin films.
Thermosensitive aqueous solutions of polyvinylacetone
NASA Astrophysics Data System (ADS)
Wu, Wei-Tai; Wang, Yusong; Shi, Lei; Zhu, Qingren; Pang, Wenmin; Xu, Guoyong; Lu, Fei
2006-04-01
The dimethylketals of poly(vinyl alcohol), termed polyvinylacetone (PVKA), of moderate ketalization degree in the range from 0.28 to 0.6 exhibited temperature-induced phase transition in aqueous solution, as revealed by cloud point measurements and electron micrographs, which was then further investigated on molecular level using solution-state 1H NMR measurements. The present phase transition is caused by the amphiphilic characteristics in the polymer chain. Moreover, this finding could be further applied as a novel strategy in the syntheses of thermosensitive polymer by the hydrophobic functionalities of linear polyol.
Electrodialysis operation with buffer solution
Hryn, John N.; Daniels, Edward J.; Krumdick, Greg K.
2009-12-15
A new method for improving the efficiency of electrodialysis (ED) cells and stacks, in particular those used in chemical synthesis. The process entails adding a buffer solution to the stack for subsequent depletion in the stack during electrolysis. The buffer solution is regenerated continuously after depletion. This buffer process serves to control the hydrogen ion or hydroxide ion concentration so as to protect the active sites of electrodialysis membranes. The process enables electrodialysis processing options for products that are sensitive to pH changes.
Schwarzschild Solution: A Historical Perspective
NASA Astrophysics Data System (ADS)
Bartusiak, Marcia
2016-03-01
While eighteenth-century Newtonians had imagined a precursor to the black hole, the modern version has its roots in the first full solution to Einstein's equations of general relativity, derived by the German astronomer Karl Schwarzschild on a World War I battlefront just weeks after Einstein introduced his completed theory in November 1915. This talk will demonstrate how Schwarzschild's solution is linked to the black hole and how it took more than half a century for the physics community to accept that such a bizarre celestial object could exist in the universe.
Thermal Treatment of EDTA Solutions
Denne, B.
2006-07-01
Chemical cleaning of commercial nuclear power facility secondary systems, using EDTA, results in large volumes of chelated liquids requiring some form of treatment prior to disposal. The Nuclear Regulatory Commission regulates the presence of chelates in disposal cells and this paper will look at several methods used to ensure compliance with disposal site criteria. The emphasis of this paper will be on results achieved through thermal treatment of chemical cleaning wastes at the Pacific EcoSolutions' (PEcoS) low level and mixed radioactive waste processing facility in Richland, Washington. We will discuss challenges in transportation, receipt, storage, processing, and disposal associated with EDTA solutions and how those challenges are overcome. (author)
Analytical Solution for Reactive Solute Transport Considering Incomplete Mixing
NASA Astrophysics Data System (ADS)
Bellin, A.; Chiogna, G.
2013-12-01
The laboratory experiments of Gramling et al. (2002) showed that incomplete mixing at the pore scale exerts a significant impact on transport of reactive solutes and that assuming complete mixing leads to overestimation of product concentration in bimolecular reactions. We consider here the family of equilibrium reactions for which the concentration of the reactants and the product can be expressed as a function of the mixing ratio, the concentration of a fictitious non reactive solute. For this type of reactions we propose, in agreement with previous studies, to model the effect of incomplete mixing at scales smaller than the Darcy scale assuming that the mixing ratio is distributed within an REV according to a Beta distribution. We compute the parameters of the Beta model by imposing that the mean concentration is equal to the value that the concentration assumes at the continuum Darcy scale, while the variance decays with time as a power law. We show that our model reproduces the concentration profiles of the reaction product measured in the Gramling et al. (2002) experiments using the transport parameters obtained from conservative experiments and an instantaneous reaction kinetic. The results are obtained applying analytical solutions both for conservative and for reactive solute transport, thereby providing a method to handle the effect of incomplete mixing on multispecies reactive solute transport, which is simpler than other previously developed methods. Gramling, C. M., C. F. Harvey, and L. C. Meigs (2002), Reactive transport in porous media: A comparison of model prediction with laboratory visualization, Environ. Sci. Technol., 36(11), 2508-2514.
Graphical Solution of Polynomial Equations
ERIC Educational Resources Information Center
Grishin, Anatole
2009-01-01
Graphing utilities, such as the ubiquitous graphing calculator, are often used in finding the approximate real roots of polynomial equations. In this paper the author offers a simple graphing technique that allows one to find all solutions of a polynomial equation (1) of arbitrary degree; (2) with real or complex coefficients; and (3) possessing…
Homotopy Solutions of Kepler's Equations
NASA Technical Reports Server (NTRS)
Fitz-Coy, Norman; Jang, Jiann-Woei
1996-01-01
Kepler's Equation is solved using an integrative algorithm developed using homotropy theory. The solution approach is applicable to both elliptic and hyperbolic forms of Kepler's Equation. The results from the proposed algorithm compare quite favorably with those from existing iterative schemes.
Aqueous Solution Chemistry of Plutonium
Clark, David L.
2014-01-28
Things I have learned working with plutonium: Chemistry of plutonium is complex; Redox equilibria make Pu solution chemistry particularly challenging in the absence of complexing ligands; Understanding this behavior is key to successful Pu chemistry experiments; There is no suitable chemical analog for plutonium.
CESIUM RECOVERY FROM AQUEOUS SOLUTIONS
Goodall, C.A.
1960-09-13
A process is given for precipitating cesium on zinc ferricyanide (at least 0.0004 M) from aqueous solutions containing mineral acid in a concentration of from 0.2 N acidity to 0.61 N acid-deficiency and advantageously, but not necessarily, also aluminum nitrate in a concentration of from l to 2.5 M.
Boggle Logic Puzzles: Minimal Solutions
ERIC Educational Resources Information Center
Needleman, Jonathan
2013-01-01
Boggle logic puzzles are based on the popular word game Boggle played backwards. Given a list of words, the problem is to recreate the board. We explore these puzzles on a 3 x 3 board and find the minimum number of three-letter words needed to create a puzzle with a unique solution. We conclude with a series of open questions.
Hydrophobic Solvation: Aqueous Methane Solutions
ERIC Educational Resources Information Center
Konrod, Oliver; Lankau, Timm
2007-01-01
A basic introduction to concept of a solvation shell around an apolar solute as well as its detection is presented. The hydrophobic solvation of toluene is found to be a good teaching example which connects macroscopic, phenomenological thermodynamic results with an atomistic point of view.
RESISTIVE SOLUTIONS FOR PULSAR MAGNETOSPHERES
Li, Jason; Spitkovsky, Anatoly; Tchekhovskoy, Alexander
2012-02-10
The current state of the art in the modeling of pulsar magnetospheres invokes either the vacuum or force-free limits for the magnetospheric plasma. Neither of these limits can simultaneously account for both the plasma currents and the accelerating electric fields that are needed to explain the morphology and spectra of high-energy emission from pulsars. To better understand the structure of such magnetospheres, we combine accelerating fields and force-free solutions by considering models of magnetospheres filled with resistive plasma. We formulate Ohm's law in the minimal velocity fluid frame and construct a family of resistive solutions that smoothly bridges the gap between the vacuum and the force-free magnetosphere solutions. The spin-down luminosity, open field line potential drop, and the fraction of open field lines all transition between the vacuum and force-free values as the plasma conductivity varies from zero to infinity. For fixed inclination angle, we find that the spin-down luminosity depends linearly on the open field line potential drop. We consider the implications of our resistive solutions for the spin-down of intermittent pulsars and sub-pulse drift phenomena in radio pulsars.
Evaluation of ITRF2014 Solutions
NASA Astrophysics Data System (ADS)
Dach, R.; Susnik, A.; Maier, A.; Villiger, A.; Arnold, D.; Jaeggi, A.
2016-12-01
For the most recent IERS Terrestrial Reference Frame(IERS-TRF) realization three candidates have been provided, namely an ITRF2014 solution by IGN, DTRF2014 by DGFI-TUM, and JTRF2014 by JPL. There are significant differences in the way how these solutions have been generated and which parametrization has been applied. In the paper we confront our most recent GNSS reprocessing solution generated in the frame of the EGSIEM project (European Gravity Service for Improved Emergency Management; funded by EC in the frame of Horizon 2020) with these reference frame realizations. That the coordinate time series are well presented by all solution can be expected. We will investigate the effects on geodynamic relevant parameters like Earth rotation parameters and geocenter time series. Also the GNSS satellite orbits will be validated whether there exist some differences when applying the different reference frame realizations. With this contribution we hope to provide an independent contribution to the discussion about the advantages and disadvantages of the different methods to generate the IERS-TRF.
Sucrose diffusion in aqueous solution
Murray, Benjamin J.
2016-01-01
The diffusion of sugar in aqueous solution is important both in nature and in technological applications, yet measurements of diffusion coefficients at low water content are scarce. We report directly measured sucrose diffusion coefficients in aqueous solution. Our technique utilises a Raman isotope tracer method to monitor the diffusion of non-deuterated and deuterated sucrose across a boundary between the two aqueous solutions. At a water activity of 0.4 (equivalent to 90 wt% sucrose) at room temperature, the diffusion coefficient of sucrose was determined to be approximately four orders of magnitude smaller than that of water in the same material. Using literature viscosity data, we show that, although inappropriate for the prediction of water diffusion, the Stokes–Einstein equation works well for predicting sucrose diffusion under the conditions studied. As well as providing information of importance to the fundamental understanding of diffusion in binary solutions, these data have technological, pharmaceutical and medical implications, for example in cryopreservation. Moreover, in the atmosphere, slow organic diffusion may have important implications for aerosol growth, chemistry and evaporation, where processes may be limited by the inability of a molecule to diffuse between the bulk and the surface of a particle. PMID:27364512
Solar Energy - Solution or Pipedream?
ERIC Educational Resources Information Center
Polk, Joyce
This series of lessons and class activities is designed for presentation in a sequence of nine class days. The collection is intended to provide the student in advanced science classes with awareness of the possibilities and limitations of solar energy as a potential solution to the energy crisis. Included are discussion of the following: (1)…
Hydrophobic Solvation: Aqueous Methane Solutions
ERIC Educational Resources Information Center
Konrod, Oliver; Lankau, Timm
2007-01-01
A basic introduction to concept of a solvation shell around an apolar solute as well as its detection is presented. The hydrophobic solvation of toluene is found to be a good teaching example which connects macroscopic, phenomenological thermodynamic results with an atomistic point of view.
Processes in Verbal Analogy Solution.
ERIC Educational Resources Information Center
Grudin, Jonathan
1980-01-01
Verbal analogy solution is more flexible than is suggested by either the standard process theory or Sternberg's theory. It was determined that subjects initially examine terms A and B; if this strategy is not successful, they examine the relationship between A and C. (Author/CP)
Complete solution of Boolean equations
NASA Technical Reports Server (NTRS)
Tapia, M. A.; Tucker, J. H.
1980-01-01
A method is presented for generating a single formula involving arbitary Boolean parameters, which includes in it each and every possible solution of a system of Boolean equations. An alternate condition equivalent to a known necessary and sufficient condition for solving a system of Boolean equations is given.
Stability of pilocarpine ophthalmic solutions.
Pilatti, C; Torre, M C; Chiale, C; Spinetto, M
1999-06-01
The stability of pilocarpine and pilocarpine-timolol eyedrop preparations available on the Argentine market was studied. A high-performance liquid chromatographic method that allows the estimation of pilocarpine in the presence of degradation products was used for the study according to the preestablished design. It was found that pilocarpine solutions are stable, while pilocarpine in association with timolol shows significant degradation.
Bioanalysis: challenges and solutions seminar.
Roberts, Andrew
2011-09-01
Industry challenges and solutions for bioanalysis were top of the agenda for the Spring Seminar organized by Quotient Bioresearch in Munich, Germany. The seminar was attended by representatives from pharmaceutical and biotechnology organisations across Europe and featured debates and panel discussions from leading industry speakers on new techniques and hot topics, including the latest industry guidelines.
Archival storage solutions for PACS
NASA Astrophysics Data System (ADS)
Chunn, Timothy
1997-05-01
While they are many, one of the inhibitors to the wide spread diffusion of PACS systems has been robust, cost effective digital archive storage solutions. Moreover, an automated Nearline solution is key to a central, sharable data repository, enabling many applications such as PACS, telemedicine and teleradiology, and information warehousing and data mining for research such as patient outcome analysis. Selecting the right solution depends on a number of factors: capacity requirements, write and retrieval performance requirements, scaleability in capacity and performance, configuration architecture and flexibility, subsystem availability and reliability, security requirements, system cost, achievable benefits and cost savings, investment protection, strategic fit and more.This paper addresses many of these issues. It compares and positions optical disk and magnetic tape technologies, which are the predominant archive mediums today. Price and performance comparisons will be made at different archive capacities, plus the effect of file size on storage system throughput will be analyzed. The concept of automated migration of images from high performance, high cost storage devices to high capacity, low cost storage devices will be introduced as a viable way to minimize overall storage costs for an archive. The concept of access density will also be introduced and applied to the selection of the most cost effective archive solution.
NASA Astrophysics Data System (ADS)
Ormancey, E.
2008-07-01
The need for Single Sign On has always been restricted by the absence of cross platform solutions: a single sign on working only on one platform or technology is nearly useless. The recent improvements in Web Services Federation (WS-Federation) standard enabling federation of identity, attribute, authentication and authorization information can now provide real extended Single Sign On solutions. Various solutions have been investigated at CERN and now, a Web SSO solution using some parts of WS-Federation technology is available. Using the Shibboleth Service Provider module for Apache hosted web sites and Microsoft ADFS as the identity provider linked to Active Directory user, users can now authenticate on any web application using a single authentication platform, providing identity, user information (building, phone...) as well as group membership enabling authorization possibilities. A typical scenario: a CERN user can now authenticate on a Linux/Apache website using Windows Integrated credentials, and his Active Directory group membership can be checked before allowing access to a specific web page.
Universities Becoming the Outsourcing Solution
ERIC Educational Resources Information Center
Bohley, Katharine A.
2010-01-01
This paper provides a road map for universities to follow in responding to corporations that are in need of a solution to the dilemma of building an executive development program and simultaneously providing their executives with a high quality MBA degree. Difficulties experienced by many corporations are complicated by the fact that MBA programs…
Marijuana legalization: solution or dissolution.
Cohen, S
1981-01-01
What is being suggested as the most feasible course now is a standfast position on the legal front; an aggressive, directed research program planned to answer the critical questions about marijuana; and a discouragement policy for adolescents. Legalization is not seen as a tenable solution for many reasons, and it is one that may be irreversible and regretted.
Optimized solution of Kepler's equation
NASA Technical Reports Server (NTRS)
Kohout, J. M.; Layton, L.
1972-01-01
A detailed description is presented of KEPLER, an IBM 360 computer program used for the solution of Kepler's equation for eccentric anomaly. The program KEPLER employs a second-order Newton-Raphson differential correction process, and it is faster than previously developed programs by an order of magnitude.
Microheterogeneity in frozen protein solutions.
Twomey, Alan; Kurata, Kosaku; Nagare, Yutaka; Takamatsu, Hiroshi; Aksan, Alptekin
2015-06-20
In frozen and lyophilized systems, the biological to be stabilized (e.g. therapeutic protein, biomarker, drug-delivery vesicle) and the cryo-/lyo-protectant should be co-localized for successful stabilization. During freezing and drying, many factors cause physical separation of the biological from the cryo-/lyo-protectant, called microheterogeneity (MH), which may result in poor stabilization efficiency. We have developed a novel technique that utilized confocal Raman microspectroscopy in combination with counter-gradient freezing to evaluate the effect of a wide range of freezing temperatures (-20
Analysis of the Fisher solution
Abdolrahimi, Shohreh; Shoom, Andrey A.
2010-01-15
We study the d-dimensional Fisher solution which represents a static, spherically symmetric, asymptotically flat spacetime with a massless scalar field. The solution has two parameters, the mass M and the 'scalar charge' {Sigma}. The Fisher solution has a naked curvature singularity which divides the spacetime manifold into two disconnected parts. The part which is asymptotically flat we call the Fisher spacetime, and another part we call the Fisher universe. The d-dimensional Schwarzschild-Tangherlini solution and the Fisher solution belong to the same theory and are dual to each other. The duality transformation acting in the parameter space (M,{Sigma}) maps the exterior region of the Schwarzschild-Tangherlini black hole into the Fisher spacetime which has a naked timelike singularity, and interior region of the black hole into the Fisher universe, which is an anisotropic expanding-contracting universe and which has two spacelike singularities representing its 'big bang' and 'big crunch'. The big bang singularity and the singularity of the Fisher spacetime are radially weak in the sense that a 1-dimensional object moving along a timelike radial geodesic can arrive to the singularities intact. At the vicinity of the singularity the Fisher spacetime of nonzero mass has a region where its Misner-Sharp energy is negative. The Fisher universe has a marginally trapped surface corresponding to the state of its maximal expansion in the angular directions. These results and derived relations between geometric quantities of the Fisher spacetime, the Fisher universe, and the Schwarzschild-Tangherlini black hole may suggest that the massless scalar field transforms the black hole event horizon into the naked radially weak disjoint singularities of the Fisher spacetime and the Fisher universe which are 'dual to the horizon'.
Microheterogeneity in Frozen Protein Solutions
Twomey, Alan; Kurata, Kosaku; Nagare, Yutaka; Takamatsu, Hiroshi; Aksan, Alptekin
2015-01-01
In frozen and lyophilized systems, the biological to be stabilized (e.g. therapeutic protein, biomarker, drug-delivery vesicle) and the cryo-/lyoprotectant should be co-localized for successful stabilization. During freezing and drying, many factors cause physical separation of the biological from the cryo-/lyoprotectant, called microheterogeneity (MH), which may result in poor stabilization efficiency. We have developed a novel technique that utilized confocal Raman microspectroscopy in combination with counter-gradient freezing to evaluate the effect of a wide range of freezing temperatures (−20 < TF < 0°C) on the MH generated within a frozen formulation in only a few experiments. The freezing experiments conducted with a model system (albumin and trehalose) showed the presence of different degrees of MH in the freeze-concentrated liquid (FCL) in all solutions tested. Mainly, albumin tended to accumulate near the ice interface, where it was physically separated from the cryoprotectant. In frozen 10 wt% trehalose solutions, heterogeneity in FCL was relatively low at any TF. In frozen 20 wt% trehalose solutions, the optimum albumin to trehalose ratio in the FCL can only be ensured if the solution was frozen within a narrow range of temperatures (−16 < TF < −10°C). In the 30 wt% trehalose solutions, freezing within a much more narrow range (−12 < TF < −10°C) was needed to ensure a fairly homogeneous FCL. The method developed here will be helpful for the development of uniformly frozen and stable formulations and freezing protocols for biological as MH is presumed to directly impact stability. PMID:25888798
The Coupling of Solute Fluxes in Membranes
Galey, William R.; Van Bruggen, J. T.
1970-01-01
Our previous description of solute drag on a synthetic membrane has been extended to include the solutes mannitol, sucrose, raffinose, inulin, and dextran. Labeled and nonlabeled forms of these solutes were used in pairs to quantitate solute flux interaction. Three membranes with pore sizes of 350, 80, and 20 A, respectively, have been utilized. It is shown that solute flux interaction occurs with all the solutes and that the extent of interaction is related directly to solute permeability, concentration, and molecular size. The magnitude of solute interaction is reciprocally related to the radii of the membrane pores, greater interaction occurring with small pored membranes. Solute drag is seen as an increased flux of tracer solute in the direction of the diffusion gradient of a second solute as well as a decreased tracer flux into the diffusion gradient. Values are given for self-diffusion and interaction coefficients as well as for a new coefficient, the "effectiveness coefficient." PMID:5413079
Cost Effective and Affordable Guidance and Control Systems.
1985-02-01
VILLACOUBLAY -FRANCE RESUME La technologie du gyrolaser a maintenant dvolud de sorte que ce capteur est devenu utilisable sur des missiles tactiques de...MOVENNE PORI L E par R. de Salaherry 12 J5N, dJ J.N frJAU.) IV tiJJ)IUut)t, ll. * .N O Reference UTILISATION D’UN MAGNETOMETRE AUTOCOMPENSE DANS UN...solution inertielle 5min performante et un ou plusleurs capteurs d’appoint. Pour illustrer cette mdthode, on prdsente un exemple intdressant :celui do
NASA Astrophysics Data System (ADS)
Tariq Khalil, Talat; Taillefumier, Baptiste; Boulanouar, Omar; Mavon, Christophe; Fromm, Michel
2016-09-01
L'environnement chimique de l'ADN en situation biologique est complexe notam-ment en raison de la présence d'histones, protéines nucléaires, associées en quantité approximativement égales à l'ADN pour former la chromatine. Les histones possèdent de nombreux radicaux basiques arginine et lysine chargés positivement et dont la majorité se trouve sur les chaînes émergentes, l'ADN présente quant à lui des charges négatives sur ses groupements phosphates localisés tout au long de la double hélice. Dans cette étude, la complexité de la structure de la chromatine nucléaire est dans un premier temps mimée en solution aqueuse par la formation de complexes entre un ADN plasmidique sonde et les trois acides aminés basiques, Arg, His, Lys, qui, mis à part His, sont protonés au pH physiologique. Ces acides aminés libres en solution sont réputés être des capteurs efficaces de radicaux libres, notamment pour le radical hydroxyle, conférant ainsi un pouvoir protecteur vis-à-vis des effets indirects sur l'ADN en situation d'exposition aux rayonnements ionisants. A concentration fixée, les capacités de capture des acides aminés libres, σ, pour le radical hydroxyle sont typiquement les suivantes σHis ≈σArg > σLys (σLys ≈ 0,1 × σArg). Nous avons mesuré les taux de cassures simple brin par plasmide et par Gray (χ) lors d'expositions de solutions aqueuses de complexes [acide aminé - ADN plasmidique] aux rayons X ultra-mous (1,5 keV). A concentrations égales, les trois acides aminés complexés et présents en large excès ne manifestent pas une capacité de protection de l'ADN proportionnelle à leur capacité de capture libre et en solution ; on trouve en effet des taux de cassures dans l'ordre suivant χHis > χArg > χLys (χLys ≈ 0,01 χArg). Après avoir détaillé le mode opératoire de ces mesures, nous analyserons sur des bases bibliographiques, les modes spécifiques d'interaction des acides aminés basiques avec l'ADN. La sp
Phase diagrams of polyelectrolyte solutions
NASA Astrophysics Data System (ADS)
Mahdi, Khaled A.
We study the phase diagram of polyelectrolyte solutions in salt and salt-free environments. We examine the phase behavior of polyelectrolyte solutions, in the semidilute regime, using different physical models, namely the Random Phase Approximation (RPA) and the cross-linked model. In the RPA, we calculate the electrostatic free energy by summing all the fluctuations of the chains and all present ionic species. Within this approximation, the phase diagrams of salt-free polyelectrolyte solutions show phase separation even without including short-range attractions or ion condensation. We find that the phase behavior of large chains resembles the phase diagram of polymer network solutions. That is, the equilibrium is established between a network phase and a chain-free phase. Upon the addition of salt, the dissociated ions increase the entropy of the system and overcome the energy from the electrostatic fluctuations. When the short-range attraction between monomers is included in the model, the free energy predicts phase segregation for all salt valences at high salt concentrations (1 mol/l and higher). The phenomenon is called salting-out and occurs simply because the addition of salt reduces the quality of the solvent and induces precipitation. However, phase segregation in the presence of multivalent ions in polyelectrolyte solutions occurs at low salt concentrations (less than 1 mol/l). We propose that this phase separation is due to polyions cross-linked by multivalent ions. We constructed a phenomenological two-state model to examine this phenomenon. The two phases coexisting in the solution are a network-like phase and a polymer-free phase. The polymer-free phase is modeled using Debye-Huckel theory. In the cross-linked phase, each condensed multivalent ion attracts an equal number of monomers creating a neutral cluster. The energy of the cluster is evaluated by a simple Coulombic energy. The bare monomer charges between the linkages are treated as line of
NASA Astrophysics Data System (ADS)
Bismarck, A.; Ajuriagojeaskoa, E. E.; Springer, J.; Habel, W. R.
1999-07-01
Optical fibres are widely used as physical and mechanical sensors in various matrices. Those commercial available fibres are mostly coated with different polymers (e.g. polyimide). The problem of using such coatings is the undefined adhesion and the stress transmission from the matrix material into the fibre as well as the alkaline attack from the cementitious environments onto the glass surface. Therefore the known silanisation process with alkylsilanes for surface modification was studied. To achieve a silane film onto the fibre surface as close as possible a fibre pre-treatment in oxygen plasma was applied. The wetting behaviour of the oxygen plasma treated fibres as well as the silanized fibres were studied using the Wilhelmy-method. The influence of the silane concentration and the time of the pre-treatment on the wetting properties was investigated. By scanning electron microscopy, changes of the surface morphology were detected. Additionally, the mechanical properties of the oxygen plasma treated fibres, and silanized fibres exposed to a highly alkaline pore solution were measured. For selected fibre samples (decoated and untreated as well as silanized fibres) the adhesion to a concrete matrix was studied using the indention test. Les fibres optiques sont de plus en plus utilisées comme capteurs des propriétés physiques et mécaniques de nombreuses matrices. Ces fibres commerciales sont généralement enrobées avec différents polymères (par exemple polyimide). Les problèmes dus à l'enrobage des fibres optiques sont une adhésion et une transmission de charge de la matrice du béton à la fibre non définies. Un autre problème majeur est l'alcalinité du béton et son influence sur la surface de la fibre. Nous avons utilisé le procédé de silanisation. Pour obtenir un film de silane le plus homogène possible sur la surface, les fibres sont pré-traitées par le plasma d?oxygène. Le mouillage de fibres traitées par le plasma d?oxygène, ainsi que
Solid-state ring laser gyroscope
NASA Astrophysics Data System (ADS)
Schwartz, S.
é et durée de vie. On étudie dans cet ouvrage la possibilité de substituer au milieu à gain gazeux un milieu solide (Nd-YAG pompé diode). On présente pour cela une étude théorique et expérimentale des différents régimes de fonctionnement du laser en anneau à état solide. On montre que la stabilité du régime bidirectionnel peut être garantie par une boucle de contre-réaction agissant sur les états de polarisation pour créer des pertes différentielles proportionnelles à la différence d'intensité entre les modes contrarotatifs. Cette technique permet l'obtention d'un gyrolaser à état solide, dont la réponse en fréquence est perturbée par les couplages entre modes. Plusieurs solutions, optiques et mécaniques, sont ensuite étudiées, dans le but d'améliorer la qualité de cette réponse en fréquence. En particulier, la mise en vibration du milieu à gain le long de l'axe optique apparaît comme une solution très prometteuse pour l'obtention de bonnes performances inertielles avec un gyrolaser à état solide.
REMOVAL OF CHLORIDE FROM AQUEOUS SOLUTIONS
Schulz, W.W.
1959-08-01
The removal of chlorides from aqueons solutions is described. The process involves contacting the aqueous chloride containing solution with a benzene solution about 0.005 M in phenyl mercuric acetate whereby the chloride anions are taken up by the organic phase and separating the organic phase from the aqueous solutions.
Revealing Numerical Solutions of a Differential Equation
ERIC Educational Resources Information Center
Glaister, P.
2006-01-01
In this article, the author considers a student exercise that involves determining the exact and numerical solutions of a particular differential equation. He shows how a typical student solution is at variance with a numerical solution, suggesting that the numerical solution is incorrect. However, further investigation shows that this numerical…
Analysis of earth rotation solution from Starlette
NASA Technical Reports Server (NTRS)
Schutz, B. E.; Cheng, M. K.; Shum, C. K.; Eanes, R. J.; Tapley, B. D.
1989-01-01
Earth rotation parameter (ERP) solutions were derived from the Starlette orbit analysis during the Main MERIT Campaign, using a technique of a consider-covariance analysis to assess the effects of errors on the polar motion solutions. The polar motion solution was then improved through the simultaneous adjustment of some dynamical parameters representing identified dominant perturbing sources (such as the geopotential and ocean-tide coefficients) on the polar motion solutions. Finally, an improved ERP solution was derived using the gravity field model, PTCF1, described by Tapley et al. (1986). The accuracy of the Starlette ERP solution was assessed by a comparison with the LAGEOS-derived ERP solutions.
Analysis of earth rotation solution from Starlette
NASA Technical Reports Server (NTRS)
Schutz, B. E.; Cheng, M. K.; Shum, C. K.; Eanes, R. J.; Tapley, B. D.
1989-01-01
Earth rotation parameter (ERP) solutions were derived from the Starlette orbit analysis during the Main MERIT Campaign, using a technique of a consider-covariance analysis to assess the effects of errors on the polar motion solutions. The polar motion solution was then improved through the simultaneous adjustment of some dynamical parameters representing identified dominant perturbing sources (such as the geopotential and ocean-tide coefficients) on the polar motion solutions. Finally, an improved ERP solution was derived using the gravity field model, PTCF1, described by Tapley et al. (1986). The accuracy of the Starlette ERP solution was assessed by a comparison with the LAGEOS-derived ERP solutions.
Finite solutions of fully fuzzy linear system
NASA Astrophysics Data System (ADS)
Malkawi, Ghassan; Ahmad, Nazihah; Ibrahim, Haslinda
2014-12-01
The solution of Fully Fuzzy Linear System (FFLS) is normally categorized as unique, finite and infinitely many solutions. However, in the case of more than one solution, the finite or alternative solution is not detected when linear programming is considered. Therefore this paper aims to provide a method of using min-max system and absolute system to append new concept for the consistency of FFLS, which is called finite solution of FFLS, where the FFLS have more than two solutions, and not only an infinite solution.
Fissile solution dynamics: Student research
Hetrick, D.L.
1994-09-01
There are two research projects in criticality safety at the University of Arizona: one in dynamic simulation of hypothetical criticality accidents in fissile solutions, and one in criticality benchmarks using transport theory. We have used the data from nuclear excursions in KEWB, CRAC, and SILENE to help in building models for solution excursions. An equation of state for liquids containing gas bubbles has been developed and coupled to point-reactor dynamics in an attempt to predict fission rate, yield, pressure, and kinetic energy. It appears that radiolytic gas is unimportant until after the first peak, but that it does strongly affect the shape of the subsequent power decrease and also the dynamic pressure.
Spinning of hydroalcoholic chitosan solutions.
Desorme, Mylène; Montembault, Alexandra; Lucas, Jean-Michel; Rochas, Cyrille; Bouet, Thierry; David, Laurent
2013-10-15
We investigated the spinning of hydroalcoholic chitosan solutions. The dope composition was optimized in order to obtain a continuous alcogel fiber by water evaporation on heating the extruded hydroalcoholic solution. This alcogel fiber was then neutralized in aqueous alkali baths and washed in water to eliminate the residual alcohol and salts before final drying. Depending on the alcohol content in the filament at the neutralization step, on specific alcohol-chitosan interactions and on the nature and concentration of the coagulation base, the process yielded semicrystalline chitosan fibers with different proportions of anhydrous and hydrated allomorphs. Contrarily to the classical annealing method, the formation of mainly anhydrous crystals was obtained without significant molecular weight decrease by neutralizing the polymer in hydrophobic conditions. The control of allomorph content was shown to be related to the hydrophobicity of the solvent (alcohol fraction) at the neutralization step. Copyright © 2013 Elsevier Ltd. All rights reserved.
DNA denaturation in ionic solution
NASA Astrophysics Data System (ADS)
Maity, Arghya; Singh, Amar; Singh, Navin
2016-05-01
Salt or cations, present in solution play an important role in DNA denaturation and folding kinetics of DNA helix. In this work we study the thermal melting of double stranded DNA (dsDNA) molecule using Peyrard Bishop Dauxois (PBD) model. We modify the potential of H-bonding between the bases of the complimentary strands to introduce the salt and solvent effect. We choose different DNA sequences having different contents of GC pairs and calculate the melting temperatures. The melting temperature increases logarithmically with the salt concentration of the solution. The more GC base pairs in the chain enhance the stability of DNA chain at a fix salt concentration. The obtained results are in good accordance with experimental findings.
Solution landscapes in nematic microfluidics
NASA Astrophysics Data System (ADS)
Crespo, M.; Majumdar, A.; Ramos, A. M.; Griffiths, I. M.
2017-08-01
We study the static equilibria of a simplified Leslie-Ericksen model for a unidirectional uniaxial nematic flow in a prototype microfluidic channel, as a function of the pressure gradient G and inverse anchoring strength, B. We numerically find multiple static equilibria for admissible pairs (G , B) and classify them according to their winding numbers and stability. The case G = 0 is analytically tractable and we numerically study how the solution landscape is transformed as G increases. We study the one-dimensional dynamical model, the sensitivity of the dynamic solutions to initial conditions and the rate of change of G and B. We provide a physically interesting example of how the time delay between the applications of G and B can determine the selection of the final steady state.
Health solutions for the poor.
Castro, J L; Fujiwara, P I; Bhambal, P; Emaille-Léotard, N; Harries, A D
2014-03-21
The International Union Against Tuberculosis and Lung Disease (The Union) is the oldest international non-governmental organisation involved in the fight against tuberculosis. In 2008, the Institute of The Union was challenged to think boldly about the future and to develop a diverse work portfolio covering a wide spectrum of lung health and other disease-related problems. The vision adopted by The Union at that time was 'Health solutions for the poor'. More recently, there has been lengthy debate about the need for the Union to concentrate just on its core mandate of tuberculosis and lung health and for the Union's vision to reflect this narrower spectrum of activity as 'Lung health solutions for the poor'. In this viewpoint article we outline our reasons for believing that this narrower vision is incompatible with The Union's mission statement, and we argue that making such a change would be a mistake.
Clean Energy Solutions Center (Presentation)
Reategui, S.
2012-07-01
The Clean Energy Ministerial launched the Clean Energy Solutions Center in April, 2011 for major economy countries, led by Australia and U.S. with other CEM partners. Partnership with UN-Energy is extending scope to support all developing countries: 1. Enhance resources on policies relating to energy access, small to medium enterprises (SMEs), and financing programs; 2. Offer expert policy assistance to all countries; 3. Expand peer to peer learning, training, and deployment and policy data for developing countries.
Mentoring adjunct faculty: innovative solutions.
Peters, Mary Anne; Boylston, Mary
2006-01-01
Rising enrollments in schools of nursing have increased the demand for qualified nursing faculty. In the midst of a nurse faculty shortage, many academic institutions are relying on adjunct faculty to fill the gap. The increasing number of adjunct faculty and their need for orientation to the faculty role presents a challenge to schools and departments of nursing. The authors discuss innovative solutions to these challenges.
Combinatorial solutions to integrable hierarchies
NASA Astrophysics Data System (ADS)
Kazarian, M. E.; Lando, S. K.
2015-06-01
This paper reviews modern approaches to the construction of formal solutions to integrable hierarchies of mathematical physics whose coefficients are answers to various enumerative problems. The relationship between these approaches and the combinatorics of symmetric groups and their representations is explained. Applications of the results to the construction of efficient computations in problems related to models of quantum field theories are described. Bibliography: 34 titles.
Controlling nucleation in protein solutions
NASA Technical Reports Server (NTRS)
Demattei, R. C.; Feigelson, R. S.
1992-01-01
A simple one-step technique for controlling the nucleation stage in protein solutions without the use of a seed crystal was developed using a specially designed apparatus in which the nucleation and growth processes can be separated. The method can be applied only to species that have a temperature-dependent solubility. The effectiveness of this 'thermonucleating' device was demonstrated with the nucleation and growth of ice, Rochelle salt, and lysozyme.
Stabilized aqueous hydrogen peroxide solution
Malin, M.J.; Sciafani, L.D.
1988-05-17
This patent describes a stabilized aqueous hydrogen peroxide solution having a pH below 7 and an amount of Ferric ion up to about 2 ppm comprising hydrogen peroxide, acetanilide having a concentration which ranges between 0.74 M Mol/L and 2.22 mMol/L, and o-benzene disulfonic acid or salt thereof at a concentration between about 0.86 mMol/L to about 1.62 mMol/L.
Intravenous Solutions for Exploration Missions
NASA Technical Reports Server (NTRS)
Miller, Fletcher J.; Niederhaus, Charles; Barlow, Karen; Griffin, DeVon
2007-01-01
This paper describes the intravenous (IV) fluids requirements being developed for medical care during NASA s future exploration class missions. Previous research on IV solution generation and mixing in space is summarized. The current exploration baseline mission profiles are introduced, potential medical conditions described and evaluated for fluidic needs, and operational issues assessed. We briefly introduce potential methods for generating IV fluids in microgravity. Conclusions on the recommended fluid volume requirements are presented.
Electrochromic Salts, Solutions, and Devices
Burrell, Anthony K.; Warner, Benjamin P.; McClesky, T. Mark
2008-10-14
Electrochromic salts. Electrochromic salts of dicationic viologens such as methyl viologen and benzyl viologen associated with anions selected from bis(trifluoromethylsulfonyl)imide, bis(perfluoroethylsulfonyl)imide, and tris(trifluoromethylsulfonyl)methide are produced by metathesis with the corresponding viologen dihalide. They are highly soluble in molten quarternary ammonium salts and together with a suitable reductant provide electrolyte solutions that are used in electrochromic windows.
Electrochromic Salts, Solutions, and Devices
Burrell, Anthony K.; Warner, Benjamin P.; McClesky, T. Mark
2008-11-11
Electrochromic salts. Electrochromic salts of dicationic viologens such as methyl viologen and benzyl viologen associated with anions selected from bis(trifluoromethylsulfonyl)imide, bis(perfluoroethylsulfonyl)imide, and tris(trifluoromethylsulfonyl)methide are produced by metathesis with the corresponding viologen dihalide. They are highly soluble in molten quarternary ammonium salts and together with a suitable reductant provide electrolyte solutions that are used in electrochromic windows.
Electrochromic salts, solutions, and devices
Burrell, Anthony K.; Warner, Benjamin P.; McClesky,7,064,212 T. Mark
2006-06-20
Electrochromic salts. Electrochromic salts of dicationic viologens such as methyl viologen and benzyl viologen associated with anions selected from bis(trifluoromethylsulfonyl)imide, bis(perfluoroethylsulfonyl)imide, and tris(trifluoromethylsulfonyl)methide are produced by metathesis with the corresponding viologen dihalide. They are highly soluble in molten quarternary ammonium salts and together with a suitable reductant provide electrolyte solutions that are used in electrochromic windows.
Myochrysine Solution Structure and Reactivity
Jones, William B.; Zhao, Zheng; Dorsey, John G.; Tepperman, Katherine
1994-01-01
We have determined the framework structure of Myochrysine (disodium gold(I)thiomalate) in the solid state and extremely concentrated aqueous solution, previously. It consists of an open chain polymer with linear gold coordination to two thiolates from the thiomalic acid moieties which bridge between pairs of gold atoms providing an Au-S-Au angle of 95°. The question remained: was this structure relevant to the dilute solutions of drugs administered and the still lower concentrations of gold found in the bodies of patients (typically 1 ppm Au in blood and urine or 5 μM in Au). We have provided an answer to that question using extended X-ray absorption spectroscopy (EXAFS) and capillary zone electrophoresis (CZE). EXAFS studies confirm that the polymeric structure with two sulfur atoms per gold atom persists from molar concentrations down to millimolar concentrations. CZE is able to separate and detect Myochrysine at millimolar levels. More importantly, at micromolar levels Myochrysine solutions exhibit identical CZE behavior to that measured at millimolar levels. Thus, aqueous solutions of the drug remain oligomeric at concentrations commensurate with those found in patient blood and urine. The reactivity of Myochrysine with cyanide, a species especially prevalent in smoking patients, was explored using CZE. Cyanide freely replaces thiomalic acid to form [Au(CN)2]- and thiomalic acid via a mixed ligand intermediate. The overall apparent equilibrium constant (Kapp) for the reaction is 6×10-4M-1. Further reaction of [Au(CN)2]- with a large excess of L, where L is cysteine, N-acetylcysteine, or glutathione, shows that these amino acids readily replace cyanide to form [AuL2]-. These species are thus potential metabolites and could possibly be active forms of gold in vivo. That all of these species are readily separated and quantified using CZE demonstrates that capillary electrophoresis is an accessible and powerful tool to add to those used for the study of gold
Dielectric decrement of electrolyte solutions
NASA Astrophysics Data System (ADS)
Felderhof, B. U.
We calculate the dielectric decrement of ionic solutions in a continuum model. We show that apart from a familiar static contribution there are three kinetic contributions to the effect, two of which are related by a symmetry relation. The third contribution is due to frequency dispersion of the friction coefficient and for small ions reduces the total effect considerably. We find that the total effect as calculated from the continuum model is too small to account for the experimental data.
Pollen Aquaporins: The Solute Factor
Pérez Di Giorgio, Juliana A.; Soto, Gabriela C.; Muschietti, Jorge P.; Amodeo, Gabriela
2016-01-01
In the recent years, the biophysical properties and presumed physiological role of aquaporins (AQPs) have been expanded to specialized cells where water and solute exchange are crucial traits. Complex but unique processes such as stomatal movement or pollen hydration and germination have been addressed not only by identifying the specific AQP involved but also by studying how these proteins integrate and coordinate cellular activities and functions. In this review, we referred specifically to pollen-specific AQPs and analyzed what has been assumed in terms of transport properties and what has been found in terms of their physiological role. Unlike that in many other cells, the AQP machinery in mature pollen lacks plasma membrane intrinsic proteins, which are extensively studied for their high water capacity exchange. Instead, a variety of TIPs and NIPs are expressed in pollen. These findings have altered the initial understanding of AQPs and water exchange to consider specific and diverse solutes that might be critical to sustaining pollen’s success. The spatial and temporal distribution of the pollen AQPs also reflects a regulatory mechanism that allowing a properly adjusting water and solute exchange. PMID:27881985
Soft confinement for polymer solutions
NASA Astrophysics Data System (ADS)
Oya, Yutaka; Kawakatsu, Toshihiro
2014-07-01
As a model of soft confinement for polymers, we investigated equilibrium shapes of a flexible vesicle that contains a phase-separating polymer solution. To simulate such a system, we combined the phase field theory (PFT) for the vesicle and the self-consistent field theory (SCFT) for the polymer solution. We observed a transition from a symmetric prolate shape of the vesicle to an asymmetric pear shape induced by the domain structure of the enclosed polymer solution. Moreover, when a non-zero spontaneous curvature of the vesicle is introduced, a re-entrant transition between the prolate and the dumbbell shapes of the vesicle is observed. This re-entrant transition is explained by considering the competition between the loss of conformational entropy and that of translational entropy of polymer chains due to the confinement by the deformable vesicle. This finding is in accordance with the recent experimental result reported by Terasawa et al. (Proc. Natl. Acad. Sci. U.S.A., 108 (2011) 5249).
Specular reflectance of aqueous solutions.
NASA Technical Reports Server (NTRS)
Querry, M. R.; Waring, R. C.; Holland, W. E.; Mansell, G. R.
1971-01-01
Description of two laboratory instruments for measuring the specular reflectance of aqueous solutions. The instruments are an organic-dye-laser spectrophotometer for the 360- to 650-nm wavelength region and a reflectometer accessory for a Perkin-Elmer E-system spectrophotometer which will operate in the 0.2- to 20-micron wavelength region. The reflectometer accessory has been used to measure the relative infrared specular reflectance in limited spectral regions for aqueous solutions of NaCl, K2SO4, ZnSO4, (NH4)2SO4, and NH4H2PO4 with radiant flux incident at about 70 deg and polarized perpendicular to the plane of incidence. The laser spectrometer has been used to measure the absolute reflectance of aqueous solutions of NaCl in the wavelength region from 575 to 610 nm for light incident at angles of about 60, 65, and 70 deg and polarized parallel to the plane of incidence.
Pollen Aquaporins: The Solute Factor.
Pérez Di Giorgio, Juliana A; Soto, Gabriela C; Muschietti, Jorge P; Amodeo, Gabriela
2016-01-01
In the recent years, the biophysical properties and presumed physiological role of aquaporins (AQPs) have been expanded to specialized cells where water and solute exchange are crucial traits. Complex but unique processes such as stomatal movement or pollen hydration and germination have been addressed not only by identifying the specific AQP involved but also by studying how these proteins integrate and coordinate cellular activities and functions. In this review, we referred specifically to pollen-specific AQPs and analyzed what has been assumed in terms of transport properties and what has been found in terms of their physiological role. Unlike that in many other cells, the AQP machinery in mature pollen lacks plasma membrane intrinsic proteins, which are extensively studied for their high water capacity exchange. Instead, a variety of TIPs and NIPs are expressed in pollen. These findings have altered the initial understanding of AQPs and water exchange to consider specific and diverse solutes that might be critical to sustaining pollen's success. The spatial and temporal distribution of the pollen AQPs also reflects a regulatory mechanism that allowing a properly adjusting water and solute exchange.
Viscoelasticity of Concentrated Proteoglycan Solutions
NASA Astrophysics Data System (ADS)
Meechai, Nispa; Jamieson, Alex; Blackwell, John; Carrino, David
2001-03-01
Proteoglycan Aggregate (PGA) is the principal macromolecular component of the energy-absorbing matrix of cartilage and tendon. Its brush-like supramolecular structure consists of highly-ionic subunits, non-covalently bound to a hyaluronate chain. We report viscoelastic behavior of concentrated solutions of PGA, purified by column fractionation to remove free subunits. At physiological ionic strength, these preparations exhibit a sol-to-gel transition when the concentration is increased above molecular overlap. The strain dependence of concentrated solutions shows a pronounced non-linearity above a critical strain, at which the storage modulus decreases suddenly, and the loss modulus exhibits a maximum. This response is similar to that observed for close-packed dispersions of soft spheres, when the applied strain is sufficient to move a sphere past its neighbors. At low and high ionic strength, the elasticity of solutions near the overlap concentration decreases. The former is interpreted as due to a decrease in intramolecular and intermolecular electrostatic repulsions, because of strong trapping of counterions within the PGA brush, the latter to salt-induced brush collapse.
Specular reflectance of aqueous solutions.
NASA Technical Reports Server (NTRS)
Querry, M. R.; Waring, R. C.; Holland, W. E.; Mansell, G. R.
1971-01-01
Description of two laboratory instruments for measuring the specular reflectance of aqueous solutions. The instruments are an organic-dye-laser spectrophotometer for the 360- to 650-nm wavelength region and a reflectometer accessory for a Perkin-Elmer E-system spectrophotometer which will operate in the 0.2- to 20-micron wavelength region. The reflectometer accessory has been used to measure the relative infrared specular reflectance in limited spectral regions for aqueous solutions of NaCl, K2SO4, ZnSO4, (NH4)2SO4, and NH4H2PO4 with radiant flux incident at about 70 deg and polarized perpendicular to the plane of incidence. The laser spectrometer has been used to measure the absolute reflectance of aqueous solutions of NaCl in the wavelength region from 575 to 610 nm for light incident at angles of about 60, 65, and 70 deg and polarized parallel to the plane of incidence.
Functionalized polymers for binding to solutes in aqueous solutions
Smith, Barbara F.; Robison, Thomas W.
2006-11-21
A functionalized polymer for binding a dissolved molecule in an aqueous solution is presented. The polymer has a backbone polymer to which one or more functional groups are covalently linked. The backbone polymer can be such polymers as polyethylenimine, polyvinylamine, polyallylamine, and polypropylamine. These polymers are generally water-soluble, but can be insoluble when cross-linked. The functional group can be for example diol derivatives, polyol derivatives, thiol and dithiol derivatives, guest-host groups, affinity groups, beta-diphosphonic acids, and beta-diamides
Conception, fabrication et validation d'un capteur de direction instantanee d'ecoulement
NASA Astrophysics Data System (ADS)
Schwaab, Quentin
A Flow Direction Probe was designed and built at the Thermo-Fluids for Transport (TFT) laboratory of Ecole de technologie superieure to enable the study of instantaneous flow reversals in a turbulent separation bubble. The probe's general form is based on the thermal-tuft probe introduced by Eaton et al. (1979). It consists of three parallel wires (one central wire and two sensing wires placed on each side) mounted close to the test surface, perpendicular to the main flow direction. The middle wire is heated by an electric current which generates a heated wake. The heated wake increases the electrical resistance of the sensing wire that is placed downstream of the central wire. Therefore, the flow direction near the wall can be determined by comparing the resistances of the two sensing wires. For that purpose, the two sensing wires are mounted in a Wheatstone bridge and a signal conditioning circuitry, which is a simplification of the one proposed by Eaton et al. (1979), delivers an output voltage that is readable by a digital data acquisition system (1 if the flow moves downstream and 0 otherwise). Therefore, the fraction of time the flow moves downstream (gamma) and the intermittent frequency (fc) can easily be computed. The probe measurement's principle has been evaluated in an acoustic resonator by generating an oscillating flow at about 200Hz. The probe was shown to be in good agreement with the acoustic reference velocity. Then, the signal conditioner performances have been tested by simulating an oscillating flow at 20Hz thanks to a mechanical shaker. A small delay has been highlighted between the sign change of the voltage across the bridge and the actual commutation of the output signal. However, this delay didn't infer the value of gamma. Finally, the probe has been implemented in the TFT's wind tunnel facility where a pressure-driven turbulent separation bubble had been created. The distributions of gamma and fc have been measured below the test surface and were in accordance with oil film visualizations.
Capteurs et algorithmes pour la localisation autonome en mode pédestre
NASA Astrophysics Data System (ADS)
Ladetto, Quentin
The challenge of knowing one's position in a precise and reliable way, at any time, with an without reception of satellite signals, represents an area fairly explored for the navigation of vehicles. To widen this service to the pedestrians requires a different approach that adapts to the dynamics, to the speed and especially to the total freedom of movement of the people. The traditional approach implements a triad of accelerometers and gyroscopes, which signals are integrated to obtain the relative displacement. This concept is unfortunately not judicious for a low-cost system. The principal reason is that the speed of displacement of a person is lost in the sensor noise level. In order to take into account all these specificities, an occurential approach was developed, based upon a subset of sensors as well as physiological and biomechanical parameters of the walk. This research is devided into three main directions. The first area of interest consists in the determination of the physiological parameters necessary to quantify the speed of walk and the step length. The second part directly relates to the multiple technologies integrated to build an autonomous three-dimensional Pedestrian Navigation Module (PNM). The third part described the integration of the models and measurements as well as the characteristics and treatments specific to pedestrian navigation.
Commercial Lighting Solutions Webtool Peer Review Report, Office Solutions
Beeson, Tracy A.; Jones, Carol C.
2010-02-01
The Commercial Lighting Solutions (CLS) project directly supports the U.S. Department of Energy’s Commercial Building Energy Alliance efforts to design high performance buildings. CLS creates energy efficient best practice lighting designs for widespread use, and they are made available to users via an interactive webtool that both educates and guides the end user through the application of the Lighting Solutions. This report summarizes the peer review of the CLS webtool for offices. The methodology for the peer review process included data collection (stakeholder input), analysis of the comments, and organization of the input into categories for prioritization of the comments against a set of criteria. Based on this process, recommendations were developed for the release of version 2.0 of the webtool at the Lightfair conference in Las Vegas in May 2010. The report provides a list of the top ten most significant and relevant improvements that will be made within the webtool for version 2.0 as well as appendices containing the comments and short-term priorities in additional detail. Peer review comments that are considered high priority by the reviewers and the CLS team but cannot be completed for Version 2.0 are listed as long-term recommendations.
NASA Astrophysics Data System (ADS)
Guo, Zongming; Wei, Juncheng; Zhou, Feng
2017-07-01
Positive singular radial entire solutions of a biharmonic equation with subcritical exponent are obtained via the entire radial solutions of the equation with supercritical exponent and the Kelvin's transformation. The expansions of such singular radial solutions at the singular point 0 are presented. Using these singular radial entire solutions, we construct solutions with a prescribed singular set for the Navier boundary value problem
Rotating regular black hole solution
NASA Astrophysics Data System (ADS)
Abdujabbarov, Ahmadjon
2016-07-01
Based on the Newman-Janis algorithm, the Ayón-Beato-García spacetime metric [Phys. Rev. Lett. 80, 5056 (1998)] of the regular spherically symmetric, static, and charged black hole has been converted into rotational form. It is shown that the derived solution for rotating a regular black hole is regular and the critical value of the electric charge for which two horizons merge into one sufficiently decreases in the presence of the nonvanishing rotation parameter a of the black hole.
Transition state structures in solution
Bertran, J.; Lluch, J. M.; Gonzalez-Lafont, A.; Dillet, V.; Perez, V.
1995-04-05
In the present paper the location of transition state structures for reactions in solution has been studied. Continuum model calculations have been carried out on the Friedel-Crafts alkylation reaction and a proton transfer through a water molecule between two oxygen atoms in formic acid. In this model the separation between the chemical system and the solvent has been introduced. On the other hand, the discrete Monte Carlo methodology has also been used to simulate the solvent effect on dissociative electron transfer processes. In this model, the hypothesis of separability is not assumed. Finally, the validity of both approaches is discussed.
Transition state structures in solution
NASA Astrophysics Data System (ADS)
Bertrán, J.; Lluch, J. M.; Gonzàlez-Lafont, A.; Dillet, V.; Pérez, V.
1995-04-01
In the present paper the location of transition state structures for reactions in solution has been studied. Continuum model calculations have been carried out on the Friedel-Crafts alkylation reaction and a proton transfer through a water molecule between two oxygen atoms in formic acid. In this model the separation between the chemical system and the solvent has been introduced. On the other hand, the discrete Monte Carlo methodology has also been used to simulate the solvent effect on dissociative electron transfer processes. In this model, the hypothesis of separability is not assumed. Finally, the validity of both approaches is discussed.
Solutions for a cultivated planet.
Foley, Jonathan A; Ramankutty, Navin; Brauman, Kate A; Cassidy, Emily S; Gerber, James S; Johnston, Matt; Mueller, Nathaniel D; O'Connell, Christine; Ray, Deepak K; West, Paul C; Balzer, Christian; Bennett, Elena M; Carpenter, Stephen R; Hill, Jason; Monfreda, Chad; Polasky, Stephen; Rockström, Johan; Sheehan, John; Siebert, Stefan; Tilman, David; Zaks, David P M
2011-10-12
Increasing population and consumption are placing unprecedented demands on agriculture and natural resources. Today, approximately a billion people are chronically malnourished while our agricultural systems are concurrently degrading land, water, biodiversity and climate on a global scale. To meet the world's future food security and sustainability needs, food production must grow substantially while, at the same time, agriculture's environmental footprint must shrink dramatically. Here we analyse solutions to this dilemma, showing that tremendous progress could be made by halting agricultural expansion, closing 'yield gaps' on underperforming lands, increasing cropping efficiency, shifting diets and reducing waste. Together, these strategies could double food production while greatly reducing the environmental impacts of agriculture.
Optical limiting in Buckminsterfullerene solutions
Brandelik, D.M.; McLean, D.G.; Schmitt, M.
1992-12-01
New results on solutions of Buckminsterfullerene in toluene as optical limiters with low limiting thresholds are reported. Limiting thresholds are as low as 15mJ/cm{sup 2} with multiple pulse stability. Evidence for a different mechanism than that operational in graphitic carbon black suspensions is presented. Calculated hyperpolarizability values are presented. The combined CW and Q-switched responses of this material and the promise of lower nonlinear thresholds has potential for application in optical protection devices ranging from welder safety goggles to safe surgical endoscopes.
Quantitative Scattering of Melanin Solutions
NASA Astrophysics Data System (ADS)
Riesz, J.; Gilmore, J.; Meredith, P.
2006-06-01
The optical scattering coefficient of a dilute, well solubilised eumelanin solution has been accurately measured as a function of incident wavelength, and found to contribute less than 6% of the total optical attenuation between 210 and 325nm. At longer wavelengths (325nm to 800nm) the scattering was less than the minimum sensitivity of our instrument. This indicates that UV and visible optical density spectra can be interpreted as true absorption with a high degree of confidence. The scattering coefficient vs wavelength was found to be consistent with Rayleigh Theory for a particle radius of 38+-1nm.
Einstein-Cartan wormhole solutions
NASA Astrophysics Data System (ADS)
Mehdizadeh, Mohammad Reza; Ziaie, Amir Hadi
2017-03-01
In the present work, we investigate wormhole structures and the energy conditions supporting them in Einstein-Cartan theory. The matter content consists of a Weyssenhoff fluid along with an anisotropic matter which together generalize the anisotropic energy momentum tensor in general relativity (GR) to include spin effects. Assuming that the radial pressure and energy density obey a linear equation of state, we introduce exact asymptotically flat and anti-de-Sitter spacetimes that admit traversable wormholes and respect energy conditions. Such wormhole solutions are studied in detail for two specific forms for the redshift function, namely a constant redshift function and the one with power law dependency.
Stochastic solution to quantum dynamics
NASA Technical Reports Server (NTRS)
John, Sarah; Wilson, John W.
1994-01-01
The quantum Liouville equation in the Wigner representation is solved numerically by using Monte Carlo methods. For incremental time steps, the propagation is implemented as a classical evolution in phase space modified by a quantum correction. The correction, which is a momentum jump function, is simulated in the quasi-classical approximation via a stochastic process. The technique, which is developed and validated in two- and three- dimensional momentum space, extends an earlier one-dimensional work. Also, by developing a new algorithm, the application to bound state motion in an anharmonic quartic potential shows better agreement with exact solutions in two-dimensional phase space.
Nucleoside phosphorylation in amide solutions
NASA Technical Reports Server (NTRS)
Schoffstall, A. M.; Kokko, B.
1978-01-01
The paper deals with phosphorylation in possible prebiotic nonaqueous solvents. To this end, phosphorylation of nucleosides using inorganic phosphates in amide solutions is studied at room and elevated temperatures. Reaction proceeds most readily in formamide and N-methylformamide. Products obtained at elevated temperature are nucleotides, nucleoside 2',3'-cyclic phosphates, and when the phosphate concentration is high, nucleoside diphosphates. At room temperature, adenosine afforded a mixture of nucleotides, but none of the cyclic nucleotide. Conditions leading to the highest relative percentage of cyclic nucleotide involve the use of low concentrations of phosphate and an excess of nucleoside.
Analytic solutions of the relativistic Boltzmann equation
NASA Astrophysics Data System (ADS)
Hatta, Yoshitaka; Martinez, Mauricio; Xiao, Bo-Wen
2015-04-01
We present new analytic solutions to the relativistic Boltzmann equation within the relaxation time approximation. We first obtain spherically expanding solutions which are the kinetic counterparts of the exact solutions of the Israel-Stewart equation in the literature. This allows us to compare the solutions of the kinetic and hydrodynamic equations at an analytical level. We then derive a novel boost-invariant solution of the Boltzmann equation which has an unconventional dependence on the proper time. The existence of such a solution is also suggested in second-order hydrodynamics and fluid-gravity correspondence.
Holographic cosmology from BIonic solutions
NASA Astrophysics Data System (ADS)
Sepehri, Alireza; Faizal, Mir; Setare, Mohammad Reza; Ali, Ahmed Farag
2017-02-01
In this paper, we will use a BIonic solution for analyzing the holographic cosmology. A BIonic solution is a configuration of a D3-brane and an anti-D3-brane connected by a wormhole, and holographic cosmology is a recent proposal to explain cosmic expansion by using the holographic principle. In our model, a BIonic configuration will be produced by the transition of fundamental black strings. The formation of a BIonic configuration will cause inflation. As the D3-brane moves away from the anti-D3-brane, the wormhole will get annihilated, and the inflation will end with the annihilation of this wormhole. However, it is possible for a D3-brane to collide with an anti-D3-brane. Such a collision will occur if the distance between the D3-brane and the anti-D3-brane reduces, and this will create tachyonic states. We will demonstrate that these tachyonic states will lead to the formation of a new wormhole, and this will cause acceleration of the universe before such a collision.
Uniqueness of large positive solutions
NASA Astrophysics Data System (ADS)
López-Gómez, Julián; Maire, Luis
2017-08-01
We establish the uniqueness of the positive solution of the singular problem (1.1) through some standard comparison techniques involving the maximum principle. Our proofs do not invoke to the blow-up rates of the solutions, as in most of the specialized literature. We give two different types of results according to the geometrical properties of Ω and the regularity of partial Ω . Even in the autonomous case, our theorems are extremely sharp extensions of all existing results. Precisely, when a(x)≡ 1, it is shown that the monotonicity and superadditivity of f( u) with constant C≥ 0 entail the uniqueness; f is said to be superadditive with constant C≥ 0 if f(a+b) ≥ f(a) + f(b) - C \\quad for all a, b ≥ 0. This condition, introduced by Marcus and Véron (J Evol Equ 3:637-652, 2004), weakens all previous sufficient conditions for uniqueness, as it will become apparent in this paper.
Ultrafast studies of solution dynamics
Woodruff, W.H.; Dyer, R.B.; Callender, R.H.
1997-10-01
This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Fast chemical dynamics generally must be initiated photochemically. This limits the applicability of modern laser methods for following the structural changes that occur during chemical and biological reactions to those systems that have an electronic chromophore that has a significant yield of photoproduct when excited. This project has developed a new and entirely general approach to ultrafast initiation of reactions in solution: laser-induced temperature jump (T-jump). The results open entire new fields of study of ultrafast molecular dynamics in solution. The authors have demonstrated the T-jump technique on time scales of 50 ps and longer, and have applied it to study of the fast events in protein folding. They find that a general lifetime of alpha-helix formation is ca 100 ns, and that tertiary folds (in apomyoglobin) form in ca 100 {mu}s.
Solution assembly of conjugated polymers
NASA Astrophysics Data System (ADS)
Bokel, Felicia A.
This dissertation focuses on the solution-state polymer assembly of conjugated polymers with specific attention to nano- and molecular-scale morphology. Understanding how to control these structures holds potential for applications in polymer-based electronics. Optimization of conjugated polymer morphology was performed with three objectives: 1) segregation of donor and acceptor materials on the nanometer length-scale, 2) achieving molecular-scale ordering in terms of crystallinity within distinct domains, and 3) maximizing the number and quality of well-defined donor/acceptor interfaces. Chapter 1 introduces the development of a mixed solvent method to create crystalline poly(3-hexyl thiophene) (P3HT) fibrils in solution. Chapter 2 describes fibril purification and approaches to robust and functional fibrils, while chapters 3 and 4 demonstrate the formation of hybrid nanocomposite wires of P3HT and cadmium selenide (CdSe) nanoparticles by two methods: 1) co-crystallization of free and P3HT-grafted CdSe for composite nanowires and 2) direct attachment of CdSe nanoparticles at fibril edges to give superhighway structures. These composite structures show great potential in the application of optoelectronic devices, such as the active layer of solar cells. Finally, ultrafast photophysical characterization of these polymers, using time-resolved photoluminescence and transient absorption, was performed to determine the aggregation types present in suspended fibrils and monitor the formation and decay of charged species in fibrils and donor-acceptor systems.
Speech privacy: Beyond architectural solutions
NASA Astrophysics Data System (ADS)
Mazer, Susan
2005-09-01
HIPAA regulations have brought unparalleled pressures on healthcare organizations to protect private and confidential information from reaching third parties. Yet, as this paper explains, often in the middle of noisy corridors and waiting rooms, this same information needs to be quickly transferred from physician to nurse to family member to others for the care of patients. Research and examples are presented that show that when families, patients, staff are participating together, although independently, in the same or adjacent spaces, the ``caf effect'' produces rising noise levels as each person competes to be heard. This threatens the very confidentiality demanded by HIPAA. Solutions to this problem are not easy or completely resolved by engineering or design specifications. This paper makes the case that it is ultimately the culture of a healthcare organization that determines the ``sound'' of a hospital, and any other organization that battles openness with privacy. It presents and discusses proven solutions to address culture in tandem with architectural and acoustic design interventions.
Germanium-silicon solid solutions
NASA Technical Reports Server (NTRS)
Zemskov, V. S.; Kubasov, V. N.; Belokurova, I. N.; Titkov, A. N.; Shulpina, I. L.; Safarov, V. I.; Guseva, N. B.
1977-01-01
An experiment on melting and directional crystallization of an antimony (Sb) doped germanium silicon (GeSi) solid solution was designed for the Apollo-Soyuz Test Project (ASTP) to study the possibility of using zero-g conditions for obtaining solid-solution monocrystals with uniformly distributed components. Crystallization in the zero-g environment did not occur under ideal stationary growth and segregation conditions. Crystallization under zero-g conditions revealed the heterogeneous nature of Si and Sb distribution in the cross sections of crystals. The presence of the radial thermal gradient in the multipurpose furnace could be one of the reasons for such Si and Sb distribution. The structure of space-grown crystals correlates with the nature of heterogeneities of Si and Sb distribution in crystals. The type of surface morphology and the contour observed in space-grown crystals were never observed in ground-based crystals and indicate the absence of wetting of the graphitized walls of the ampoule by the melt during melting and crystallization.
Growth of Solid Solution Crystals
NASA Technical Reports Server (NTRS)
Lehoczky, S. L.; Szofran, F. R.; Holland, L. R.
1985-01-01
The major objective of this program is to determine the conditions under which single crystals of solid solutions can be grown from the melt in a Bridgman configuration with a high degree of chemical homogeneity. The central aim is to assess the role of gravity in the growth process and to explore the possible advantages for growth in the absence of gravity. The alloy system being investigated is the solid solution semiconductor with x-values appropriate for infrared detector applications in Hg sub (1-x) Cd sub x Te the 8 to 14 micro m wavelength region. Both melt and Te-solvent growth are being considered. The study consists of an extensive ground-based experimental and theoretical research effort followed by flight experimentation where appropriate. Experimental facilities have been established for the purification, casting, and crystal growth of the alloy system. Facilities have been also established for the metallurgical, compositional, electric and optical characterization of the alloys. Crystals are being grown by the Bridgman-Stockbarger method and are analyzed by various experimental techniques to evaluate the effects of growth conditions on the longitudinal and radial compositional variations and defect densities in the crystals.
Chemical solutions for greywater recycling.
Pidou, Marc; Avery, Lisa; Stephenson, Tom; Jeffrey, Paul; Parsons, Simon A; Liu, Shuming; Memon, Fayyaz A; Jefferson, Bruce
2008-03-01
Greywater recycling is now accepted as a sustainable solution to the general increase of the fresh water demand, water shortages and for environment protection. However, the majority of the suggested treatments are biological and such technologies can be affected, especially at small scale, by the variability in strength and flow of the greywater and potential shock loading. This investigation presents the study of alternative processes, coagulation and magnetic ion exchange resin, for the treatment of greywater for reuse. The potential of these processes as well as the influence of parameters such as coagulant or resin dose, pH or contact time were investigated for the treatment of two greywaters of low and high organic strengths. The results obtained revealed that magnetic ion exchange resin and coagulation were suitable treatment solutions for low strength greywater sources. However, they were unable to achieve the required level of treatment for the reuse of medium to high strength greywaters. Consequently, these processes could only be considered as an option for greywater recycling in specific conditions that is to say in case of low organic strength greywater or less stringent standards for reuse.
Ion conductance in electrolyte solutions
NASA Astrophysics Data System (ADS)
Chandra, Amalendu; Bagchi, Biman
1999-05-01
We develop a new theoretical formulation to study ion conductance in electrolyte solutions, based on a mode coupling theory treatment of the electrolyte friction. The new theory provides expressions for both the ion atmosphere relaxation and electrophoretic contributions to the total electrolyte friction that acts on a moving ion. While the ion atmosphere relaxation term arises from the time-dependent microscopic interaction of the moving ion with the surrounding ions in the solution, the electrophoretic term originates from the coupling of the ion's velocity to the collective current mode of the ion atmosphere. Mode coupling theory, combined with time-dependent density functional theory of ion atmosphere fluctuations, leads to self-consistent expressions for these two terms which also include the effects of self-motion of the ion under consideration. These expressions have been solved for the concentration dependence of electrolyte friction and ion conductance. It is shown that in the limit of very low ion concentration, the present theory correctly reduces to the well-known Debye-Huckel-Onsager limiting law which predicts a linear dependence of conductance on the square root of ion concentration (c). At moderate and high concentrations, the present theory predicts a significant nonlinear and weaker dependence on √c which is in very good agreement with experimental results. The present theory is self-contained and does not involve any adjustable parameter.
Aqueous Solution Chemistry on Mars
NASA Astrophysics Data System (ADS)
Quinn, R.; Hecht, M.; Kounaves, S.; Young, S.; West, S.; Fisher, A.; Grunthaner, P.
2007-12-01
Currently en route to Mars, the Phoenix mission carries four wet chemistry cells designed to perform basic solution chemistry on martian soil. The measurement objectives are typical of those that would be performed on an unknown sample on Earth, including detection of common anions and cations, total conductivity, pH, redox potential, cyclic voltammetry (CV), etc. Both the challenge and the novelty arise from the necessity to perform these measurements with severely constrained resources in a harsh and (literally) alien environment. Sensors for all measurements are integrated into a common "beaker," with the ability to perform a two-point calibration of some sensors using a pair of low-concentration solutions. Sulfate measurement is performed with a crude titration. While most measurements use ion selective electrodes, halide interferences are resolved by independent chronopotentiometry (CP) measurements. No preconditioning of the soil-water mixture is possible, nor is any physical characterization of the introduced soil sample beyond coarse visual inspection. Among the idiosyncrasies of the measurement is the low external pressure, which requires that the analysis be performed close to the boiling point of water under an atmosphere consisting almost entirely of water vapor. Despite these liabilities, however, extensive laboratory characterization has validated the basic approach, and protocols for both CV and CP have been developed and tested. Enhancing the value of the measurement is the suite of coordinated observations, such as microscopy and evolved gas analysis, to be performed by other Phoenix instruments.
Fluctuating Hydrodynamics of Electrolytes Solutions
NASA Astrophysics Data System (ADS)
Peraud, Jean-Philippe; Nonaka, Andy; Chaudhri, Anuj; Bell, John B.; Donev, Aleksandar; Garcia, Alejandro L.
2016-11-01
In this work, we develop a numerical method for multicomponent solutions featuring electrolytes, in the context of fluctuating hydrodynamics as modeled by the Landau-Lifshitz Navier Stokes equations. Starting from a previously developed numerical scheme for multicomponent low Mach number fluctuating hydrodynamics, we study the effect of the additional forcing terms induced by charged species. We validate our numerical approach with additional theoretical considerations and with examples involving sodium-chloride solutions, with length scales close to Debye length. In particular, we show how charged species modify the structure factors of the fluctuations, both in equilibrium and non-equilibrium (giant fluctuations) systems, and show that the former is consistent with Debye-Huckel theory. We also discuss the consistency of this approach with the electroneutral approximation in regimes where characteristic length scales are significantly larger than the Debye length. Finally, we use this method to explore a type of electrokinetic instability. This work was supported by the U.S. Department of Energy, Office of Science, Office of Advanced Scientific Computing Research,.
Solution Potentials Indicate Aluminum-Alloy Tempers
NASA Technical Reports Server (NTRS)
Danford, M. D.
1985-01-01
Report discusses use of solution potential as measure of temper of aluminum alloys. Technique based on fact that different tempers or heat treatments exhibit different solution potentials as function of aging time.
Polycondensation kinetics of furfuryl alcohol solutions
NASA Astrophysics Data System (ADS)
Zherebtsov, D. A.; Galimov, D. M.; Zagorul'ko, O. V.; Frolova, E. V.; Bol'shakov, O. I.; Zakharov, V. G.; Mikhailov, G. G.
2016-01-01
Changes in the viscosity, electrical conductivity, monomer concentration, and the size of growing molecules of polycondensed furfuryl alcohol are studied in solutions containing triethylene glycol and isooctylphenyldecaethylene glycol. The effect the solution compositions have on the condensation kinetics is considered.
[Determination of taste sensitivity with mixed solutions].
Marco Algarra, R
1990-01-01
In the second part of our study we present the results of the mixture of four basic tastes in comparison with those of the simple solutions, mea ng as well the fatigue phenomenon with the mixed solutions.
Simple Solutions for Treating Dry Mouth
Patient Education Sheet Simple Solutions for Treating Dry Mouth Clinicians: Please make as many copies of this ... Philadelphia, for authoring “Simple Solutions for Treating Dry Mouth.” Ask your family doctor to discontinue or provide ...
Control of microorganisms in flowing nutrient solutions
NASA Astrophysics Data System (ADS)
Evans, R. D.
1994-11-01
Controlling microorganisms in flowing nutrient solutions involves different techniques when targeting the nutrient solution, hardware surfaces in contact with the solution, or the active root zone. This review presents basic principles and applications of a number of treatment techniques, including disinfection by chemicals, ultrafiltration, ultrasonics, and heat treatment, with emphasis on UV irradiation and ozone treatment. Procedures for control of specific pathogens by nutrient solution conditioning also are reviewed.
Static solutions for fourth order gravity
Nelson, William
2010-11-15
The Lichnerowicz and Israel theorems are extended to higher order theories of gravity. In particular it is shown that Schwarzschild is the unique spherically symmetric, static, asymptotically flat, black-hole solution, provided the spatial curvature is less than the quantum gravity scale outside the horizon. It is then shown that in the presence of matter (satisfying certain positivity requirements), the only static and asymptotically flat solutions of general relativity that are also solutions of higher order gravity are the vacuum solutions.
Thermodynamics of rock forming crystalline solutions
NASA Technical Reports Server (NTRS)
Saxena, S. K.
1971-01-01
Analysis of phase diagrams and cation distributions within crystalline solutions as means of obtaining thermodynamic data on rock forming crystalline solutions is discussed along with some aspects of partitioning of elements in coexisting phases. Crystalline solutions, components in a silicate mineral, and chemical potentials of these components were defined. Examples were given for calculating thermodynamic mixing functions in the CaW04-SrW04, olivine-chloride solution, and orthopyroxene systems.
Dynamical intersecting brane solutions of supergravity
Uzawa, Kunihito
2010-02-10
We present dynamical intersecting brane solutions in higher-dimensional gravitational theory coupled to dilaton and several forms. Assuming the forms of metric, form fields, and dilaton field, we can give the dynamical intersecting brane solutions. The dynamical solutions can be always obtained by replacing the constant modulus h{sub 0} in the warp factor for supersymmetric solutions by a linear function h{sub 0}(t) of the time coordinates t.
ELECTROLYTIC REDUCTION OF NITRIC ACID SOLUTIONS
Alter, H.W.; Barney, D.L.
1958-09-30
A process is presented for the treatment of radioactivc waste nitric acid solutions. The nitric acid solution is neutralized with an alkali metal hydroxide in an amount sufficient to precipitate insoluble hydroxides, and after separation of the precipitate the solution is electrolyzed to convert the alkali nitrate formed, to alkali hydroxide, gaseous ammonla and oxygen. The solution is then reusable after reducing the volume by evaporating the water and dissolved ammonia.
Periodic solutions of Fokker-Planck equations
NASA Astrophysics Data System (ADS)
Chen, Feng; Han, Yuecai; Li, Yong; Yang, Xue
2017-07-01
In this paper, the existence of periodic solutions of Fokker-Planck equations is obtained by discussing the existence of periodic solutions in distribution for some stochastic differential equations. To prove the existence of periodic solutions in distribution for stochastic differential equations, a new criterion analogous to Halanay's criterion is given. Actually, the criterion is similar to a law of large numbers. Based on this criterion, the existence of periodic solutions in distribution for stochastic (functional) differential equations is established by Lyapunov's method.
Exact solutions and singularities in string theory
Horowitz, G.T. ); Tseytlin, A.A. )
1994-10-15
We construct two new classes of exact solutions to string theory which are not of the standard plane wave of gauged WZW type. Many of these solutions have curvature singularities. The first class includes the fundamental string solution, for which the string coupling vanishes near the singularity. This suggests that the singularity may not be removed by quantum corrections. The second class consists of hybrids of plane wave and gauged WZW solutions. We discuss a four-dimensional example in detail.
Engineering report (conceptual design) PFP solution stabilization
Witt, J.B.
1997-07-17
This Engineering Report (Conceptual Design) addresses remediation of the plutonium-bearing solutions currently in inventory at the Plutonium Finishing Plant (PFP). The recommendation from the Environmental Impact Statement (EIS) is that the solutions be treated thermally and stabilized as a solid for long term storage. For solutions which are not discardable, the baseline plan is to utilize a denitration process to stabilize the solutions prior to packaging for storage.
Control of microorganisms in flowing nutrient solutions.
Evans, R D
1994-11-01
Controlling microorganisms in flowing nutrient solutions involves different techniques when targeting the nutrient solution, hardware surfaces in contact with the solution, or the active root zone. This review presents basic principles and applications of a number of treatment techniques, including disinfection by chemicals, ultrafiltration, ultrasonics, and heat treatment, with emphasis on UV irradiation and ozone treatment. Procedures for control of specific pathogens by nutrient solution conditioning also are reviewed.
Fullerene triplet states in solution
NASA Astrophysics Data System (ADS)
Ausman, Kevin Douglas
Triplet state pre-equilibration by reversible energy transfer has been observed by transient-absorption spectroscopy in mixed toluene solutions of C70 and C60 and of C70 and C60(CH 3)2. The equilibrium constants governing the asymptotic partitioning of triplet energy in these mixtures were determined as a function of temperature. The enthalpies of these excited states were found from van't Hoff plots of the equilibrium constant data to be -0.1 +/- 0.2 and -3.4 +/- 0.3 kJ mol-1 for C60 and C60 (CH3)2 respectively relative to a C70 triplet energy exchange partner. The corresponding relative entropies are 5.8 +/- 0.5 and -4.0 +/- 1.0 kJ mol-1 K-1 respectively. Transient spectra from high temperature C70/C60(CH3)2 mixed samples revealed evidence of a third, unidentified transient absorber that exhibited different kinetics from the pre-equilibrated triplet pool. Triplet state transient difference spectra and intrinsic decay kinetics were measured and compared for C60 and several derivatives of C 60. These derivatives were C60H2, C60(CH 3)2, ortho-xylyl-C60, N,N'-dimethyl-1,2-ethylenediamine- C 60, C60C(COOCH2CH3)2, and C60O. The spectral locations of the main triplet-triplet absorption peak for these compounds correlates linearly with the observed intrinsic intersystem crossing rate constant. The triplet state persistence of C60 was measured in toluene solution as a function of both ground state concentration and solution temperature. The unimolecular intersystem crossing deactivation channel shows very little thermal activation, whereas the observed bimolecular self-quenching decay channel is found to be highly activated. At room temperature, the deduced exponential lifetime of the solvent-caged encounter complex between triplet and ground state molecules is three orders of magnitude shorter than that of the isolated monomer triplet state. This suggests that the self-quenching process is not a simple perturbation of an isolated molecule's intersystem crossing, but
Fiber coating with surfactant solutions
NASA Astrophysics Data System (ADS)
Shen, Amy Q.; Gleason, Blake; McKinley, Gareth H.; Stone, Howard A.
2002-11-01
When a fiber is withdrawn at low speeds from a pure fluid, the variation in the thickness of the entrained film with imposed fiber velocity is well-predicted by the Landau-Levich-Derjaguin (LLD) equation. However, surfactant additives are known to alter this response. We study the film thickening properties of the protein BSA (bovine serum albumin), the nonionic surfactant Triton X-100, and the anionic surfactant SDS (sodium dodecyl sulfate). For each of these additives, the film thickening factor alpha (the ratio of the measured thickness to the LLD prediction) for a fixed fiber radius varies as a function of the ratio of the surfactant concentration c to the critical micelle concentration (CMC). In the case of BSA, which does not form micelles, the reference value is the concentration at which multilayers form. As a result of Marangoni effects, alpha reaches a maximum as c approaches the CMC from below. However, when the surfactant concentration c exceeds the CMC, the behavior of alpha varies as a consequence of the dynamic surface properties, owing for example to different sorption kinetics of these additives, or possibly surface or bulk rheological effects. For SDS, alpha begins to decrease when c exceeds the CMC and causes the surface to become partially or completely remobilized, which is consistent with the experimental and theoretical results published for studies of slug flows of bubbles and surfactant solutions in a capillary tube and the rise of bubbles in surfactant solutions. However, when the SDS or Triton X-100 surfactant concentration is well above the CMC, we observe that the film thickening parameter alpha increases once again. In the case of SDS we observe a second maximum in the film thickening factor. For all the experiments, transport of monomers to the interface is limited by diffusion and the second maximum in the film thickening factor may be explained as a result of a nonmonotonic change in the stability characteristics of suspended SDS
Subharmonic Solutions of Order One-Third
ERIC Educational Resources Information Center
Fay, Temple H.
2005-01-01
Finding a periodic solution to a nonlinear ordinary differential equation is in general a difficult task. Only in a very few cases can direct methods be applied to an equation to find initial values leading to a solution of the corresponding initial value problem that is periodic. Oscillatory periodic solutions have such practical importance that…
Clean Energy Solutions Center Services (Fact Sheet)
Not Available
2014-04-01
The Clean Energy Solutions Center (Solutions Center) helps governments, advisors and analysts create policies and programs that advance the deployment of clean energy technologies. The Solutions Center partners with international organizations to provide online training, expert assistance, and technical resources on clean energy policy.
The Classification of Highly Supersymmetric Supergravity Solutions
Gran, U.; Gutowski, J.; Papadopoulos, G.; Roest, D.
2009-02-02
The spinorial geometry method is an effective method for constructing systematic classifications of supersymmetric supergravity solutions. Recent work on analysing highly supersymmetric solutions in type IIB supergravity using this method is reviewed. It is shown that all supersymmetric solutions of IIB supergravity with more than 28 Killing spinors are locally maximally supersymmetric.
27 CFR 21.119 - Nicotine solution.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Nicotine solution. 21.119....119 Nicotine solution. (a) Composition. Five gallons of an aqueous solution containing 40 percent nicotine; 3.6 avoirdupois ounces of methylene blue, U.S.P.; water sufficient to make 100 gallons. (b) Color...
27 CFR 21.119 - Nicotine solution.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Nicotine solution. 21.119....119 Nicotine solution. (a) Composition. Five gallons of an aqueous solution containing 40 percent nicotine; 3.6 avoirdupois ounces of methylene blue, U.S.P.; water sufficient to make 100 gallons. (b) Color...
27 CFR 21.119 - Nicotine solution.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Nicotine solution. 21.119....119 Nicotine solution. (a) Composition. Five gallons of an aqueous solution containing 40 percent nicotine; 3.6 avoirdupois ounces of methylene blue, U.S.P.; water sufficient to make 100 gallons. (b) Color...
27 CFR 21.119 - Nicotine solution.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Nicotine solution. 21.119....119 Nicotine solution. (a) Composition. Five gallons of an aqueous solution containing 40 percent nicotine; 3.6 avoirdupois ounces of methylene blue, U.S.P.; water sufficient to make 100 gallons. (b) Color...
27 CFR 21.119 - Nicotine solution.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Nicotine solution. 21.119....119 Nicotine solution. (a) Composition. Five gallons of an aqueous solution containing 40 percent nicotine; 3.6 avoirdupois ounces of methylene blue, U.S.P.; water sufficient to make 100 gallons. (b) Color...
21 CFR 522.1020 - Gelatin solution.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Gelatin solution. 522.1020 Section 522.1020 Food... Gelatin solution. (a) Specifications. It is sterile and each 100 cubic centimeters contains 8 grams of gelatin in an 0.85 percent sodium chloride solution. (b) Sponsor. See No. 000856 in § 510.600(c) of...
21 CFR 522.1020 - Gelatin solution.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Gelatin solution. 522.1020 Section 522.1020 Food... Gelatin solution. (a) Specifications. It is sterile and each 100 cubic centimeters contains 8 grams of gelatin in an 0.85 percent sodium chloride solution. (b) Sponsor. See No. 000856 in § 510.600(c) of...
21 CFR 522.1020 - Gelatin solution.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Gelatin solution. 522.1020 Section 522.1020 Food... Gelatin solution. (a) Specifications. It is sterile and each 100 cubic centimeters contains 8 grams of gelatin in an 0.85 percent sodium chloride solution. (b) Sponsor. See No. 000856 in § 510.600(c) of...
21 CFR 520.1454 - Moxidectin solution.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Moxidectin solution. 520.1454 Section 520.1454... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1454 Moxidectin solution. (a) Specifications. Each milliliter (mL) of solution contains 1 milligram (mg) moxidectin. (b) Sponsor. See...
21 CFR 522.2012 - Prostalene solution.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Prostalene solution. 522.2012 Section 522.2012 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Prostalene solution. (a) Specifications. Each milliliter of sterile solution contains 1 milligram...
21 CFR 522.2012 - Prostalene solution.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Prostalene solution. 522.2012 Section 522.2012 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Prostalene solution. (a) Specifications. Each milliliter of sterile solution contains 1 milligram...
21 CFR 522.2012 - Prostalene solution.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Prostalene solution. 522.2012 Section 522.2012 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Prostalene solution. (a) Specifications. Each milliliter of sterile solution contains 1 milligram...
21 CFR 520.1454 - Moxidectin solution.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Moxidectin solution. 520.1454 Section 520.1454... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1454 Moxidectin solution. (a) Specifications. Each milliliter (mL) of solution contains 1 milligram (mg) moxidectin. (b) Sponsor. See...
21 CFR 522.2012 - Prostalene solution.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Prostalene solution. 522.2012 Section 522.2012 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Prostalene solution. (a) Specifications. Each milliliter of sterile solution contains 1 milligram...
Hyperscaling violating solutions in generalised EMD theory
NASA Astrophysics Data System (ADS)
Li, Li
2017-04-01
This short note is devoted to deriving scaling but hyperscaling violating solutions in a generalised Einstein-Maxwell-Dilaton theory with an arbitrary number of scalars and vectors. We obtain analytic solutions in some special case and discuss the physical constraints on the allowed parameter range in order to have a well-defined holographic ground-state solution.
21 CFR 522.900 - Euthanasia solution.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Euthanasia solution. 522.900 Section 522.900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Euthanasia solution. (a) Specifications. Each milliliter (mL) of solution contains: (1) 390 milligrams (mg...
21 CFR 522.900 - Euthanasia solution.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Euthanasia solution. 522.900 Section 522.900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Euthanasia solution. (a) Specifications. Each milliliter (mL) of solution contains: (1) 390 milligrams (mg...
21 CFR 522.900 - Euthanasia solution.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Euthanasia solution. 522.900 Section 522.900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Euthanasia solution. (a) Specifications. Each milliliter (mL) of solution contains: (1) 390 milligrams (mg...
21 CFR 522.900 - Euthanasia solution.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Euthanasia solution. 522.900 Section 522.900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Euthanasia solution. (a) Specifications. Each milliliter (mL) of solution contains: (1) 390 milligrams (mg...
NASA Astrophysics Data System (ADS)
Xue, Shuqiang; Yang, Yuanxi
2017-02-01
Although purely using the GNSS (Global Navigation Satellite System) users cannot obtain the theoretical GDOP minimum unless the GNSS positioning is aided by a certain number of pseudolites, discussing this problem is still meaningful in understanding the issues about the positioning geometry, such as the PDOP minimization. Many literatures have pointed that the GDOP (Geometric Dilution of Precision) minimum in 3-D positioning is the root square of 10/n where n is the total number of GNSS satellites or ground-based beacons with known coordinates. As the case with five known points concerned in this paper, the current knowledge indicates that the GDOP can reach the minimum the root square of 2, but our discussion shows that the GDOP minimum with five known points cannot get the theoretical minimum the root square of 2, although there are infinite positioning configurations with the lowest PDOP. Fortunately, we can find a positioning configuration with the GDOP 1.428 which is very close to the theoretical minimum 1.414. The PDOP can always reach the theoretical minimum the root square of 9/n, and there are infinite solutions for n > 4. However for GDOP minimization, only when n > 5, infinite solutions can be obtained. The configurations with the lowest GDOPs can be given by solving a set of nonlinear algebraic equations.
Thermodynamics of black plane solution
NASA Astrophysics Data System (ADS)
Rodrigues, Manuel E.; Jardim, Deborah F.; Houndjo, Stéphane J. M.; Myrzakulov, Ratbay
2013-11-01
We obtain a new phantom black plane solution in D of the Einstein-Maxwell theory coupled with a cosmological constant. We analyse their basic properties, as well as its causal structure, and obtain the extensive and intensive thermodynamic variables, as well as the specific heat and the first law. Through the specific heat and the so-called geometric methods, we analyse in detail their thermodynamic properties, the extreme and phase transition limits, as well as the local and global stabilities of the system. The normal case is shown with an extreme limit and the phantom one with a phase transition only for null mass, which is physically inaccessible. The systems present local and global stabilities for certain values of the entropy density with respect to the electric charge, for the canonical and grand canonical ensembles.
Analysis of Enterprise Workflow Solutions
NASA Astrophysics Data System (ADS)
Chen, Cui-E.; Wang, Shulin; Chen, Ying; Meng, Yang; Ma, Hua
Since the 90’s, workflow technology has been widely applied in various industries, such as office automation(OA), manufacturing, telecommunications services, banking, securities, insurance and other financial services, research institutes and education services, and so on, to improve business process automation and integration capabilities. In this paper, based on Workflow theory, the author proposed a set of policy-based workflow approach in order to support dynamic workflow patterns. Through the expansion of the functions of Shark, it implemented a Workflow engine component-OAShark which can support retrieval / rollback function. The related classes were programmed. The technology was applied to the OA system of an enterprise project. The realization of the enterprise workflow solutions greatly improved the efficiency of the office automation.
Symmetries from the solution manifold
NASA Astrophysics Data System (ADS)
Aldaya, Víctor; Guerrero, Julio; Lopez-Ruiz, Francisco F.; Cossío, Francisco
2015-07-01
We face a revision of the role of symmetries of a physical system aiming at characterizing the corresponding Solution Manifold (SM) by means of Noether invariants as a preliminary step towards a proper, non-canonical, quantization. To this end, "point symmetries" of the Lagrangian are generally not enough, and we must resort to the more general concept of contact symmetries. They are defined in terms of the Poincaré-Cartan form, which allows us, in turn, to find the symplectic structure on the SM, through some sort of Hamilton-Jacobi (HJ) transformation. These basic symmetries are realized as Hamiltonian vector fields, associated with (coordinate) functions on the SM, lifted back to the Evolution Manifold through the inverse of this HJ mapping, that constitutes an inverse of the Noether Theorem. The specific examples of a particle moving on S3, at the mechanical level, and nonlinear SU(2)-sigma model in field theory are sketched.
Photovoltaics, the solar electric solution
NASA Astrophysics Data System (ADS)
Beach, C. D.; Litka, A. H.
Direct conversion of solar energy to electricity by photovoltaic devices (solar cells) may be the most promising solution to the current energy problem. Photovoltaic energy systems provide a clean, simple method of energy conversion, and are reliable, safe, and flexible with respect to size (modular). The federal government is trying to commercialize photovoltaics by funding research on new materials and manufacturing processes. Earliest commercialization will be in residential systems, where the power grid back-up provides for a reliable electrical system without storage costs. The Florida Solar Energy Center has been operating a 5 kW experimental residential facility since 1980. The facility showed an average solar irradiance in the 62.5 sq m panels of 264 kw-hours/day from December 1980 through February 1981. The overall system efficiency was 7%, and the inverter operated with an ac output/dc input efficiency of 85-90%, depending on input levels.
Euclid Data Handling Design Solutions
NASA Astrophysics Data System (ADS)
Bogiatto, Roberto; Tramutola, Antonio; Maddaleno, Corrado; Maiorano, Elena; Colombo, Cyril
2014-08-01
Euclid is the next medium-class mission of ESA's Science Programme, to be launched by 2020.The objective of Euclid is to investigate dark energy and dark matter, essential but mysterious components of today's standard model of cosmology. The complete survey will comprise hundreds of thousands of images and several tens of Petabytes of data. The significant amount of scientific data to be stored on-board and transmitted to Ground, imposes some challenging spacecraft requirements leading to innovative design solutions for the data handling and on-board communications.After the mission presentation, the paper provides an overview of the Spacecraft avionics architecture and deepens the Euclid data handling design concept.
Solution synthesis of germanium nanocrystals
Gerung, Henry [Albuquerque, NM; Boyle, Timothy J [Kensington, MD; Bunge, Scott D [Cuyahoga Falls, OH
2009-09-22
A method for providing a route for the synthesis of a Ge(0) nanometer-sized material from. A Ge(II) precursor is dissolved in a ligand heated to a temperature, generally between approximately 100.degree. C. and 400.degree. C., sufficient to thermally reduce the Ge(II) to Ge(0), where the ligand is a compound that can bond to the surface of the germanium nanomaterials to subsequently prevent agglomeration of the nanomaterials. The ligand encapsulates the surface of the Ge(0) material to prevent agglomeration. The resulting solution is cooled for handling, with the cooling characteristics useful in controlling the size and size distribution of the Ge(0) materials. The characteristics of the Ge(II) precursor determine whether the Ge(0) materials that result will be nanocrystals or nanowires.
Solution NMR conformation of glycosaminoglycans.
Pomin, Vitor H
2014-04-01
Nuclear magnetic resonance (NMR) spectroscopy has been giving a pivotal contribution to the progress of glycomics, mostly by elucidating the structural, dynamical, conformational and intermolecular binding aspects of carbohydrates. Particularly in the field of conformation, NOE resonances, scalar couplings, residual dipolar couplings, and chemical shift anisotropy offsets have been the principal NMR parameters utilized. Molecular dynamics calculations restrained by NMR-data input are usually employed in conjunction to generate glycosidic bond dihedral angles. Glycosaminoglycans (GAGs) are a special class of sulfated polysaccharides extensively studied worldwide. Besides regulating innumerous physiological processes, these glycans are also widely explored in the global market as either clinical or nutraceutical agents. The conformational aspects of GAGs are key regulators to the quality of interactions with the functional proteins involved in biological events. This report discusses the solution conformation of each GAG type analyzed by one or more of the above-mentioned methods.
Transport solutions for cleaner air.
Kelly, Frank J; Zhu, Tong
2016-05-20
In cities across the globe, road transport remains an important source of air pollutants that are linked with acute and chronic health effects. Decreasing vehicle emissions--while maintaining or increasing commuter journeys--remains a major challenge for city administrators. In London, congestion-charging and a citywide low-emission zone failed to bring nitrogen dioxide concentrations under control. In Beijing, controls on the purchase and use of cars have not decreased transport emissions to a sufficient extent. As cities continue to grow, not even zero-emission vehicles are the solution. Moving increasingly large numbers of people efficiently around a city can only be achieved by expanding mass transit systems. Copyright © 2016, American Association for the Advancement of Science.
Counting solutions from finite samplings
NASA Astrophysics Data System (ADS)
Huang, Haiping; Zhou, Haijun
2012-02-01
We formulate the solution counting problem within the framework of the inverse Ising problem and use fast belief propagation equations to estimate the entropy whose value provides an estimate of the true one. We test this idea on both diluted models [random 2-SAT (2-satisfiability) and 3-SAT problems] and a fully connected model (binary perceptron), and show that when the constraint density is small, this estimate can be very close to the true value. The information stored by the salamander retina under the natural movie stimuli can also be estimated, and our result is consistent with that obtained by the Monte Carlo method. Of particular significance is that the sizes of other metastable states for this real neuronal network are predicted.
Structure of supersaturated zincate solutions
Dmitrenko, V.E.; Balyakina, N.N.; Baulov, V.I.; Kotov, A.V.; Zubov, M.S.
1985-09-01
During the discharge of chemical power sources with zinc electrodes, supersaturated zincate solution (SZS) is formed from which zinc oxide or hydroxide precipitates as a function of time. The deposit detracts from the functioning of these power sources. In view of the model suggested for the structure of SZS, it is expected that a stabilizing effect would be exerted on SZS by compounds having proton-donating groups which do not give off the protons in the strongly alkaline medium and are not discharged in this medium. For a check of this, the authors chose to use xylitol and molasses in their experiments. The SZS were produced with a mock-up silver-zinc battery using the procedure previously described.
Regional Transmission Projects: Finding Solutions
The Keystone Center
2005-06-15
The Keystone Center convened and facilitated a year-long Dialogue on "Regional Transmission Projects: Finding Solutions" to develop recommendations that will help address the difficult and contentious issues related to expansions of regional electric transmission systems that are needed for reliable and economic transmission of power within and across regions. This effort brought together a cross-section of affected stakeholders and thought leaders to address the problem with the collective wisdom of their experience and interests. Transmission owners sat at the table with consumer advocates and environmental organizations. Representatives from regional transmission organizations exchanged ideas with state and federal regulators. Generation developers explored common interests with public power suppliers. Together, the Dialogue participants developed consensus solutions about how to begin unraveling some of the more intractable issues surrounding identification of need, allocation of costs, and reaching consensus on siting issues that can frustrate the development of regional transmission infrastructure. The recommendations fall into three broad categories: 1. Recommendations on appropriate institutional arrangements and processes for achieving regional consensus on the need for new or expanded transmission infrastructure 2. Recommendations on the process for siting of transmission lines 3. Recommendations on the tools needed to support regional planning, cost allocation, and siting efforts. List of Dialogue participants: List of Dialogue Participants: American Electric Power American Transmission Company American Wind Energy Association California ISO Calpine Corporation Cinergy Edison Electric Institute Environmental Defense Federal Energy Regulatory Commission Great River Energy International Transmission Company ISO-New England Iowa Public Utility Board Kanner & Associates Midwest ISO National Association of Regulatory Utility Commissioners National Association
Contribution of interstitial solute strengthening in aluminum
NASA Astrophysics Data System (ADS)
Matsui, Isao; Ono, Satoshi; Hanaoka, Yudai; Uesugi, Tokuteru; Takigawa, Yorinobu; Higashi, Kenji
2014-02-01
Enthalpies of solutions and misfit strains for the Al-X (X = H, B, C, N, and O) binary alloys were determined by first-principles calculations to estimate the strengthening of solid solutions caused by interstitial atoms. The results indicate that interstitial solute atoms produced large misfit strains. Electrodeposited Al containing 0.12-1.32 at.% C was used to assess the validity of solid-solution strengthening by interstitial solute atoms. The role that interstitial carbon plays in strengthening electrodeposited Al is discussed.
Removal of uranium from aqueous HF solutions
Pulley, Howard; Seltzer, Steven F.
1980-01-01
This invention is a simple and effective method for removing uranium from aqueous HF solutions containing trace quantities of the same. The method comprises contacting the solution with particulate calcium fluoride to form uranium-bearing particulates, permitting the particulates to settle, and separting the solution from the settled particulates. The CaF.sub.2 is selected to have a nitrogen surface area in a selected range and is employed in an amount providing a calcium fluoride/uranium weight ratio in a selected range. As applied to dilute HF solutions containing 120 ppm uranium, the method removes at least 92% of the uranium, without introducing contaminants to the product solution.
Common stock solutions, buffers, and media.
2001-05-01
RECIPES: Ammonium chloride lysing solution, 10x. Complete DMEM. Complete RPMI. DTT (DL-dithiothreitol), 0.1 M. EDTA (ethylenediamine tetraacetic acid), 0.5 M, pH 8. Ethidium bromide staining solution. FBS (fetal bovine serum). Formamide, deionized. Gel loading buffer, 6x. L-Glutamine, 0.2 M (100x). HBSS (Hanks' buffered salt solution). PBS (phosphate-buffered saline). RNase A stock solution (DNase-free), 2 mg/ml. SSC, 20x. TAE buffer, 50x. TBE buffer, 10x. TE buffer. TrisCl, 1 M. Trypsin/EDTA solution.
Computer simulation of concentrated solid solution strengthening
NASA Technical Reports Server (NTRS)
Kuo, C. T. K.; Arsenault, R. J.
1976-01-01
The interaction forces between a straight edge dislocation moving through a three-dimensional block containing a random array of solute atoms were determined. The yield stress at 0 K was obtained by determining the average maximum solute-dislocation interaction force that is encountered by edge dislocation, and an expression relating the yield stress to the length of the dislocation and the solute concentration is provided. The magnitude of the solid solution strengthening due to solute atoms can be determined directly from the numerical results, provided the dislocation line length that moves as a unit is specified.
Gravitational multisoliton solutions on flat space
NASA Astrophysics Data System (ADS)
Chen, Yu
2016-02-01
It is well known that, for even n , the n -soliton solution on the Minkowski seed, constructed using the inverse-scattering method (ISM) of Belinski and Zakharov (BZ), is the multi-Kerr-NUT solution. We show that, for odd n , the natural seed to use is the Euclidean space with two manifest translational symmetries, and the n -soliton solution is the accelerating multi-Kerr-NUT solution. We thus define the n -soliton solution on flat space for any positive integer n . It admits both Lorentzian and Euclidean sections. In the latter section, we find that a number, say m , of solitons can be eliminated in a nontrivial way by appropriately fixing their corresponding so-called BZ parameters. The resulting solutions, which may split into separate classes, are collectively denoted as [n -m ]-soliton solutions on flat space. We then carry out a systematic study of the n - and [n -m ]-soliton solutions on flat space. This includes, in particular, an explicit presentation of their ISM construction, an analysis of their local geometries, and a classification of all separate classes of solutions they form. We also show how even-soliton solutions on the seeds of the collinearly centered Gibbons-Hawking and Taub-NUT arise from these solutions.
Stability of PMR-polyimide monomer solutions
NASA Technical Reports Server (NTRS)
Lauver, R. W.; Alston, W. B.; Vannucci, R. D.
1979-01-01
The stability of alcohol solutions of norborneyl capped PMR-polyimide resins was monitored during storage at ambient and subambient temperatures. Chemical changes during storage were determined spectroscopically using nuclear magnetic resonance. Resin processability and cured resin quality were determined by fabrication of unidirectional, graphite fiber composites using aged solutions and testing of selected composite properties. PMR-15 solutions exhibit nominally two weeks of useful life and PMR-2 solutions exhibit nominally two days of useful life at ambient conditions. The limiting factor is precipitation of imide reaction produces from the monomer solutions. Both solutions exhibit substantially longer useful lifetimes in subambient storage. PMR-15 shows no precipitation after several months storage at subambient temperatures. PMR-2 solutions do exhibit precipitates after extended subambient storage, however, the precipitates formed under these conditions can be redissolved. The chemical implications of these observations are discussed.
Finite difference solutions to shocked acoustic waves
NASA Technical Reports Server (NTRS)
Walkington, N. J.; Eversman, W.
1983-01-01
The MacCormack, Lambda and split flux finite differencing schemes are used to solve a one dimensional acoustics problem. Two duct configurations were considered, a uniform duct and a converging-diverging nozzle. Asymptotic solutions for these two ducts are compared with the numerical solutions. When the acoustic amplitude and frequency are sufficiently high the acoustic signal shocks. This condition leads to a deterioration of the numerical solutions since viscous terms may be required if the shock is to be resolved. A continuous uniform duct solution is considered to demonstrate how the viscous terms modify the solution. These results are then compared with a shocked solution with and without viscous terms. Generally it is found that the most accurate solutions are those obtained using the minimum possible viscosity coefficients. All of the schemes considered give results accurate enough for acoustic power calculations with no one scheme performing significantly better than the others.
Kirkwood-Buff integrals for ideal solutions
NASA Astrophysics Data System (ADS)
Ploetz, Elizabeth A.; Bentenitis, Nikolaos; Smith, Paul E.
2010-04-01
The Kirkwood-Buff (KB) theory of solutions is a rigorous theory of solution mixtures which relates the molecular distributions between the solution components to the thermodynamic properties of the mixture. Ideal solutions represent a useful reference for understanding the properties of real solutions. Here, we derive expressions for the KB integrals, the central components of KB theory, in ideal solutions of any number of components corresponding to the three main concentration scales. The results are illustrated by use of molecular dynamics simulations for two binary solutions mixtures, benzene with toluene, and methanethiol with dimethylsulfide, which closely approach ideal behavior, and a binary mixture of benzene and methanol which is nonideal. Simulations of a quaternary mixture containing benzene, toluene, methanethiol, and dimethylsulfide suggest this system displays ideal behavior and that ideal behavior is not limited to mixtures containing a small number of components.
Pollution! Find a STEM solution!
NASA Astrophysics Data System (ADS)
Takač, Danijela; Moćan, Marina
2016-04-01
Primary and secondary school Pantovčak is an innovative school in downtown Zagreb, Croatia. The school is involved in many projects concerning STEM education. Pollution! Find a STEM solution! is a two year long cross-curricular project that grew out of identified need to develop STEM and ICT skills more. Pisa results make evident that students' knowledge is poor and motivation for math and similar subjects is low. Implying priorities of European Commission, like e-learning, raises motivation and also develops basic skills and improves knowledge in science, math, physic, ICT. Main objectives are to increase students' interest in STEM education and careers and introduce them to all available new trends in technology, engineering and science in their region by visiting clean technology industries and strengthening links with them, to introduce some future digital jobs and prepare students for rapid technological changes by integrating ICT into classroom practice more, to highlight the importance of global environmental issues and improve the knowledge in the areas of sustainable development and renewable energy, to develop collaborative partnership between schools and the wider community in formal, non-formal and informal learning, to support multilingualism by publishing Open Educational Resources in 8 different languages and to strengthen the professional profile of the teaching profession. The project brings together 231 teachers and 2729 students from five different European countries in learning to think globally and work on activities that contribute to the community's well-being. There are altogether 33 activities, divided in 4 categories. STEM activities are focused on students building the devices for measuring air, light and noise pollution in their school and homes. They use the scientific method to analyze the data and compare the results with their peers to find a solution. Eskills, digital literacy and digital jobs are focused on introducing career
Colloid solutions for fluid resuscitation.
Bunn, Frances; Trivedi, Daksha
2012-06-13
Colloids are widely used in the replacement of fluid volume. However doubts remain as to which colloid is best. Different colloids vary in their molecular weight and therefore in the length of time they remain in the circulatory system. Because of this and their other characteristics, they may differ in their safety and efficacy. To compare the effects of different colloid solutions in patients thought to need volume replacement. We searched the Cochrane Injuries Specialised Register (searched 1 Dec 2011), Cochrane Central Register of Controlled Trials 2011, issue 4 (The Cochrane Library); MEDLINE (Ovid) (1948 to November Week 3 2011); EMBASE (Ovid) (1974 to 2011 Week 47); ISI Web of Science: Science Citation Index Expanded (1970 to 1 Dec 2011); ISI Web of Science: Conference Proceedings Citation Index-Science (1990 to 1 Dec 2011); CINAHL (EBSCO) (1982 to 1 Dec 2011); National Research Register (2007, Issue 1) and PubMed (searched 1 Dec 2011). Bibliographies of trials retrieved were searched, and for the initial version of the review drug companies manufacturing colloids were contacted for information (1999). Randomised controlled trials comparing colloid solutions in critically ill and surgical patients thought to need volume replacement. Two authors independently extracted the data and assessed the quality of the trials. The outcomes sought were death, amount of whole blood transfused, and incidence of adverse reactions. Ninety trials, with a total of 5678 participants, met the inclusion criteria. Quality of allocation concealment was judged to be adequate in 35 trials and poor or uncertain in the rest.Deaths were obtained in 61 trials. For albumin or PPF versus hydroxyethyl starch (HES) 32 trials (n = 1769) reported mortality. The pooled relative risk (RR) was 1.07 (95% CI 0.87 to 1.32). When the trials by Boldt were removed from the analysis the pooled RR was 0.90 (95% CI 0.68 to 1.20). For albumin or PPF versus gelatin, nine trials (n = 824) reported
UXDs-Driven Transferring Method from TRIZ Solution to Domain Solution
NASA Astrophysics Data System (ADS)
Ma, Lihui; Cao, Guozhong; Chang, Yunxia; Wei, Zihui; Ma, Kai
The translation process from TRIZ solutions to domain solutions is an analogy-based process. TRIZ solutions, such as 40 inventive principles and the related cases, are medium-solutions for domain problems. Unexpected discoveries (UXDs) are the key factors to trigger designers to generate new ideas for domain solutions. The Algorithm of UXD resolving based on Means-Ends Analysis(MEA) is studied and an UXDs-driven transferring method from TRIZ solution to domain solution is formed. A case study shows the application of the process.
Wedge wetting by electrolyte solutions
NASA Astrophysics Data System (ADS)
Mußotter, Maximilian; Bier, Markus
2017-09-01
The wetting of a charged wedgelike wall by an electrolyte solution is investigated by means of classical density functional theory. As in other studies on wedge wetting, this geometry is considered as the most simple deviation from a planar substrate, and it serves as a first step toward more complex confinements of fluids. By focusing on fluids containing ions and surface charges, features of real systems are covered that are not accessible within the vast majority of previous theoretical studies concentrating on simple fluids in contact with uncharged wedges. In particular, the filling transition of charged wedges is necessarily of first order, because wetting transitions of charged substrates are of first order and the barrier in the effective interface potential persists below the wetting transition of a planar wall; hence, critical filling transitions are not expected to occur for ionic systems. The dependence of the critical opening angle on the surface charge, as well as the dependence of the filling height, of the wedge adsorption, and of the line tension on the opening angle and on the surface charge are analyzed in detail.
Innovative Solution to Video Enhancement
NASA Technical Reports Server (NTRS)
2001-01-01
Through a licensing agreement, Intergraph Government Solutions adapted a technology originally developed at NASA's Marshall Space Flight Center for enhanced video imaging by developing its Video Analyst(TM) System. Marshall's scientists developed the Video Image Stabilization and Registration (VISAR) technology to help FBI agents analyze video footage of the deadly 1996 Olympic Summer Games bombing in Atlanta, Georgia. VISAR technology enhanced nighttime videotapes made with hand-held camcorders, revealing important details about the explosion. Intergraph's Video Analyst System is a simple, effective, and affordable tool for video enhancement and analysis. The benefits associated with the Video Analyst System include support of full-resolution digital video, frame-by-frame analysis, and the ability to store analog video in digital format. Up to 12 hours of digital video can be stored and maintained for reliable footage analysis. The system also includes state-of-the-art features such as stabilization, image enhancement, and convolution to help improve the visibility of subjects in the video without altering underlying footage. Adaptable to many uses, Intergraph#s Video Analyst System meets the stringent demands of the law enforcement industry in the areas of surveillance, crime scene footage, sting operations, and dash-mounted video cameras.
Firnstahl, T W
1993-01-01
Timothy Firnstahl owns five successful restaurants in Seattle, but he recently came very close to owning none. In the early 1990s, he found himself, like so many restauranteurs, facing rising costs, inefficient management, and a recession. Confronting financial annihilation, Firnstahl had to act quickly: since he had no peripherals to trim, he cut off the head of his company. Remarkably, it worked. Firnstahl's problem was his new and innovative restaurant, Sharps Fresh Roasting. The heart of the Sharps concept was a unique long-roasting technique that made lean, inexpensive meats taste as juicy and delicious as fattier, expensive cuts. The process also lent itself to faster service and lower labor costs. But it wasn't working. Sharps wasn't breaking even, and his other restaurants couldn't make up the difference. He needed a solution fast. Firnstahl got his answer from Mikhail Gorbachev: slash the centralized command and liberate the company. In doing so, he would also transfer virtually all power and responsibility to his line managers. And after five months of intensive study and planning, he accomplished what he set out to do. He fired most of his corporate staff, empowered his restaurant managers with "100% Power and Responsibility," and, finally, undertook a massive promotion campaign. A year later, Sharps Fresh Roasting is the gold mine Firnstahl always believed it could be. He's done away with bureaucracy and turned business around in a down market. All this because his managers are managing themselves.
Progress towards daily "swath" solutions from GRACE
NASA Astrophysics Data System (ADS)
Save, H.; Bettadpur, S. V.; Sakumura, C.
2015-12-01
The GRACE mission has provided invaluable and the only data of its kind that measures the total water column in the Earth System over the past 13 years. The GRACE solutions available from the project have been monthly average solutions. There have been attempts by several groups to produce shorter time-window solutions with different techniques. There is also an experimental quick-look GRACE solution available from CSR that implements a sliding window approach while applying variable daily data weights. All of these GRACE solutions require special handling for data assimilation. This study explores the possibility of generating a true daily GRACE solution by computing a daily "swath" total water storage (TWS) estimate from GRACE using the Tikhonov regularization and high resolution monthly mascon estimation implemented at CSR. This paper discusses the techniques for computing such a solution and discusses the error and uncertainty characterization. We perform comparisons with official RL05 GRACE solutions and with alternate mascon solutions from CSR to understand the impact on the science results. We evaluate these solutions with emphasis on the temporal characteristics of the signal content and validate them against multiple models and in-situ data sets.
Preparation and preservation of hypoxia UW solution.
Wan, Chidang; Wang, Chunyou; Liu, Tao; Cheng, Rui; Yang, Zhiyong
2007-10-01
In order to explore the method to prepare hypoxia UW solution and the stability and preservation of hypoxia UW solution, UW solution was purged by argon or air for 15 min or 60 at a flow rate of 0.8 or 2 L/min, and the oxygen partial pressure of UW solution was detected. The hypoxia UW solution was exposed to the air or sealed up to preserve by using different methods, and the changes of oxygen partial pressure was tested. The results showed that oxygen partial presure of 50 mL UW solution, purged by argon for 15 min at a flow rate of 2 L/min, was declined from 242+/-6 mmHg to 83+/-10 mmHg. After exposure to the air, oxygen partial pressure of hypoxia UW solution was gradually increased to 160+/-7 mmHg at 48 h. After sealed up by the centrifuge tube and plastic bad filled with argon, oxygen partial pressure of hypoxia UW solution was stable, about 88+/-13 mmHg at 72 h. It was concluded that oxygen of UW solution could be purged by argon efficiently. Sealed up by the centrifuge tube and plastic bag filled with argon, oxygen partial pressure of UW solution could be stabilized.
Technical solutions to nonproliferation challenges
Satkowiak, Lawrence
2014-05-09
The threat of nuclear terrorism is real and poses a significant challenge to both U.S. and global security. For terrorists, the challenge is not so much the actual design of an improvised nuclear device (IND) but more the acquisition of the special nuclear material (SNM), either highly enriched uranium (HEU) or plutonium, to make the fission weapon. This paper provides two examples of technical solutions that were developed in support of the nonproliferation objective of reducing the opportunity for acquisition of HEU. The first example reviews technologies used to monitor centrifuge enrichment plants to determine if there is any diversion of uranium materials or misuse of facilities to produce undeclared product. The discussion begins with a brief overview of the basics of uranium processing and enrichment. The role of the International Atomic Energy Agency (IAEA), its safeguard objectives and how the technology evolved to meet those objectives will be described. The second example focuses on technologies developed and deployed to monitor the blend down of 500 metric tons of HEU from Russia's dismantled nuclear weapons to reactor fuel or low enriched uranium (LEU) under the U.S.-Russia HEU Purchase Agreement. This reactor fuel was then purchased by U.S. fuel fabricators and provided about half the fuel for the domestic power reactors. The Department of Energy established the HEU Transparency Program to provide confidence that weapons usable HEU was being blended down and thus removed from any potential theft scenario. Two measurement technologies, an enrichment meter and a flow monitor, were combined into an automated blend down monitoring system (BDMS) and were deployed to four sites in Russia to provide 24/7 monitoring of the blend down. Data was downloaded and analyzed periodically by inspectors to provide the assurances required.
Technical solutions to nonproliferation challenges
NASA Astrophysics Data System (ADS)
Satkowiak, Lawrence
2014-05-01
The threat of nuclear terrorism is real and poses a significant challenge to both U.S. and global security. For terrorists, the challenge is not so much the actual design of an improvised nuclear device (IND) but more the acquisition of the special nuclear material (SNM), either highly enriched uranium (HEU) or plutonium, to make the fission weapon. This paper provides two examples of technical solutions that were developed in support of the nonproliferation objective of reducing the opportunity for acquisition of HEU. The first example reviews technologies used to monitor centrifuge enrichment plants to determine if there is any diversion of uranium materials or misuse of facilities to produce undeclared product. The discussion begins with a brief overview of the basics of uranium processing and enrichment. The role of the International Atomic Energy Agency (IAEA), its safeguard objectives and how the technology evolved to meet those objectives will be described. The second example focuses on technologies developed and deployed to monitor the blend down of 500 metric tons of HEU from Russia's dismantled nuclear weapons to reactor fuel or low enriched uranium (LEU) under the U.S.-Russia HEU Purchase Agreement. This reactor fuel was then purchased by U.S. fuel fabricators and provided about half the fuel for the domestic power reactors. The Department of Energy established the HEU Transparency Program to provide confidence that weapons usable HEU was being blended down and thus removed from any potential theft scenario. Two measurement technologies, an enrichment meter and a flow monitor, were combined into an automated blend down monitoring system (BDMS) and were deployed to four sites in Russia to provide 24/7 monitoring of the blend down. Data was downloaded and analyzed periodically by inspectors to provide the assurances required.
METHOD FOR DECONTAMINATION OF REACTOR SOLUTIONS
Maraman, W.J.; Baxman, H.R.; Baker, R.D.
1959-05-01
A process for U recovery from phosphate fuel solutions is described. To fuel solution drawn from the reactor is added Fe(NO/sub 3/)/sub 3/ which destroys the U complex and forms ferric phosphate complex. The UO/sub 2/(NO/sub 3/)/sub 2/ formed is extracted into TBP-kerosene in a countercurrent column. The TBP contalning UO/sub 2/(NO/sub 3/)/sub 2/ is further purified by an aqueous Al(NO/ sub 3/)/sub 3/ scrub solution. The pregnant solution then goes to an H/sub 3/PO/ sub 4/ stripping and kerosene washing column. The H/sub 3/PO/sub 4/--uranyl phosphate solution is separated at the bottom and boiled to remove HNO/sub 3/ then diluted to fuel solution make-up strength. (T.R.H.)
Supergravity solutions without triholomorphic U(1) isometries
Ghezelbash, A. M.
2008-12-15
We investigate the construction of five-dimensional supergravity solutions that do not have any triholomorphic U(1) isometries. We construct a class of solutions that in various limits of parameters reduces to many of previously constructed five-dimensional supergravity solutions based on both hyper-Kaehler base spaces that can be put into a Gibbons-Hawking form and hyper-Kaehler base spaces that cannot be put into a Gibbons-Hawking form. We find a new solution which is over triaxial Bianchi type IX Einstein-hyper-Kaehler base space with no triholomorphic U(1) symmetry. One special case of this solution corresponds to a five-dimensional solution based on Eguchi-Hanson type II geometry.
Osmosis and thermodynamics explained by solute blocking.
Nelson, Peter Hugo
2017-01-01
A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult's law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed; others can be tested experimentally or by simulation.
Evaluation of taste solutions by sensor fusion
Kojima, Yohichiro; Sato, Eriko; Atobe, Masahiko; Nakashima, Miki; Kato, Yukihisa; Nonoue, Koichi; Yamano, Yoshimasa
2009-05-23
In our previous studies, properties of taste solutions were discriminated based on sound velocity and amplitude of ultrasonic waves propagating through the solutions. However, to make this method applicable to beverages which contain many taste substances, further studies are required. In this study, the waveform of an ultrasonic wave with frequency of approximately 5 MHz propagating through a solution was measured and subjected to frequency analysis. Further, taste sensors require various techniques of sensor fusion to effectively obtain chemical and physical parameter of taste solutions. A sensor fusion method of ultrasonic wave sensor and various sensors, such as the surface plasmon resonance (SPR) sensor, to estimate tastes were proposed and examined in this report. As a result, differences among pure water and two basic taste solutions were clearly observed as differences in their properties. Furthermore, a self-organizing neural network was applied to obtained data which were used to clarify the differences among solutions.
Controlled diffusion for laboratory solution preparation.
Yoshida, Makoto; Tohda, Koji; Gratzl, Miklós
2008-10-01
We report here on a method for preparation of precise laboratory solutions using controlled diffusion for dosing. The desired chemical is delivered into the target solution from a stock solution through a mass-transport-limiting delivery port that blocks convection but allows reproducible diffusive transport. Solution making with this approach involves a single step irrespective of how low the desired concentration is. Diffusional delivery of chemicals involves no appreciable movement of water and, thus, no addition of volume. The approach is therefore particularly suitable for standard addition. Precise solutions of usual laboratory volumes can be made within a short time period with proper design of the delivery port or ports. Comparison with the performance of conventional methods of routine solution preparation shows that better precision can be achieved with less labor using this approach.
RECOVERY OF TETRAVALENT CATIONS FROM AQUEOUS SOLUTIONS
Moore, R.L.
1958-05-01
The recovery of plutonium, zirconium, and tetravalent cerium values from aqueous solutions is described. It consists of adding an alkyl phosphate to a nnineral acid aqueous solution containing the metal to be recovered, whereby a precipitate forms with the tetravalent values, and separating the precipitate from the solution. All alkyl phosphates, if water-soluble, are suitable for the process; however, monobutyl phosphate has been found best.
Conformally flat solution with heat flux
Banerjee, A.; Dutta Choudhury, S. B.; Bhui, B. K.
1989-07-15
It is shown that the spherically symmetric solution previously given by Maiti is not the most general conformally flat solution for a shear-free and rotation-free fluid with heat flux. We have presented a more general solution for such a distribution and have considered the conditions of fit at the boundary of a simple spherically symmetric model with heat flux across the boundary with the exterior Vaidya metric.
Program for solution of ordinary differential equations
NASA Technical Reports Server (NTRS)
Sloate, H.
1973-01-01
A program for the solution of linear and nonlinear first order ordinary differential equations is described and user instructions are included. The program contains a new integration algorithm for the solution of initial value problems which is particularly efficient for the solution of differential equations with a wide range of eigenvalues. The program in its present form handles up to ten state variables, but expansion to handle up to fifty state variables is being investigated.
Cosmological string solutions by dimensional reduction
Behrndt, K.; Foerste, S.
1993-12-01
We obtain cosmological four dimensional solutions of the low energy effective string theory by reducing a five dimensional black hole, and black hole-de Sitter solution of the Einstein gravity down to four dimensions. The appearance of a cosmological constant in the five dimensional Einstein-Hilbert produces a special dilaton potential in the four dimensional effective string action. Cosmological scenarios implement by our solutions are discussed.
Partnering for A Solution: A Case Study
NASA Technical Reports Server (NTRS)
Jimenez-Smith, Deyrah
2003-01-01
A material-related issue has been identified, which has the potential of impacting the Space Program. Although "in-house" efforts have been underway to solve the problem, a solution has not yet been reached. This presentation shows how a GIDEP member organization is using a Problem Advisory as a solution approach in an effort to receive information from other industry and/or government organizations that may contribute in finding a solution.
Prediction of solute transport during peritoneal dialysis.
Hirszel, P; Lasrich, M; Maher, J M; Maher, J F
1979-08-01
Solute transport, predominantly diffusion, across the peritoneum correlates inversely with molecular weight. Provided that the solute is water soluble, not protein bound, not of unusual density, not ionized, does not have a large hydration shell, and is transported from plasma to dialysate, the peritoneal clearance is predictable over the molecular weight range from 60 to 11,000 daltons. Transport reates that deviate from the predicted can be explained by known physical properties of particular solutes.
Dislocation Etching Solutions for Mercury Cadmium Selenide
2014-09-01
Dislocation Etching Solutions for Mercury Cadmium Selenide by Kevin Doyle and Sudhir Trivedi ARL-CR-0744 September 2014...Etching Solutions for Mercury Cadmium Selenide Kevin Doyle and Sudhir Trivedi Sensors and Electron Devices Directorate, ARL prepared by...Solutions for Mercury Cadmium Selenide 5a. CONTRACT NUMBER W811NF-12-2-0019 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Kevin Doyle and
Anodizing And Sealing Aluminum In Nonchromated Solutions
NASA Technical Reports Server (NTRS)
Emmons, John R.; Kallenborn, Kelli J.
1995-01-01
Improved process for anodizing and sealing aluminum involves use of 5 volume percent sulfuric acid in water as anodizing solution, and 1.5 to 2.0 volume percent nickel acetate in water as sealing solution. Replaces process in which sulfuric acid used at concentrations of 10 to 20 percent. Improved process yields thinner coats offering resistance to corrosion, fatigue life, and alloy-to-alloy consistency equal to or superior to those of anodized coats produced with chromated solutions.
Markovian Solutions of Inviscid Burgers Equation
NASA Astrophysics Data System (ADS)
Chabanol, Marie-Line; Duchon, Jean
2004-01-01
For solutions of (inviscid, forceless, one dimensional) Burgers equation with random initial condition, it is heuristically shown that a stationary Feller-Markov property (with respect to the space variable) at some time is conserved at later times, and an evolution equation is derived for the infinitesimal generator. Previously known explicit solutions such as Frachebourg-Martin's (white noise initial velocity) and Carraro-Duchon's Lévy process intrinsic-statistical solutions (including Brownian initial velocity) are recovered as special cases.
Scaling solutions for dilaton quantum gravity
NASA Astrophysics Data System (ADS)
Henz, T.; Pawlowski, J. M.; Wetterich, C.
2017-06-01
Scaling solutions for the effective action in dilaton quantum gravity are investigated within the functional renormalization group approach. We find numerical solutions that connect ultraviolet and infrared fixed points as the ratio between scalar field and renormalization scale k is varied. In the Einstein frame the quantum effective action corresponding to the scaling solutions becomes independent of k. The field equations derived from this effective action can be used directly for cosmology. Scale symmetry is spontaneously broken by a non-vanishing cosmological value of the scalar field. For the cosmology corresponding to our scaling solutions, inflation arises naturally. The effective cosmological constant becomes dynamical and vanishes asymptotically as time goes to infinity.
Process for extracting technetium from alkaline solutions
Moyer, Bruce A.; Sachleben, Richard A.; Bonnesen, Peter V.
1995-01-01
A process for extracting technetium values from an aqueous alkaline solution containing at least one alkali metal hydroxide and at least one alkali metal nitrate, the at least one alkali metal nitrate having a concentration of from about 0.1 to 6 molar. The solution is contacted with a solvent consisting of a crown ether in a diluent for a period of time sufficient to selectively extract the technetium values from the aqueous alkaline solution. The solvent containing the technetium values is separated from the aqueous alkaline solution and the technetium values are stripped from the solvent.
RECOVERY OF PLUTONIUM FROM AQUEOUS SOLUTIONS
Reber, E.J.
1959-09-01
A process is described for recovering plutonium values from aqueous solutions by precipitation on bismuth phosphate. The plutonium is secured in its tetravalent state. bismuth salt is added to the solution, and ant excess of phosphoric acid anions is added to the solution in two approximately equal installments. The rate of addition of the first installment is about two to three times as high as the rate of addition of the second installment, whereby a precipitate of bismuth phosphate forms, the precipitate carrying the plutonium values. The precipitate is separated from the solution.
Generating solutions to the Einstein field equations
NASA Astrophysics Data System (ADS)
Contopoulos, I. G.; Esposito, F. P.; Kleidis, K.; Papadopoulos, D. B.; Witten, L.
2016-11-01
Exact solutions to the Einstein field equations may be generated from already existing ones (seed solutions), that admit at least one Killing vector. In this framework, a space of potentials is introduced. By the use of symmetries in this space, the set of potentials associated to a known solution is transformed into a new set, either by continuous transformations or by discrete transformations. In view of this method, and upon consideration of continuous transformations, we arrive at some exact, stationary axisymmetric solutions to the Einstein field equations in vacuum, that may be of geometrical or/and physical interest.
Relaxation solution of the full Euler equations
NASA Technical Reports Server (NTRS)
Johnson, G. M.
1982-01-01
A numerical procedure for the relaxation solution of the full steady Euler equations is described. By embedding the Euler system in a second order surrogate system, central differencing may be used in subsonic regions while retaining matrix forms well suited to iterative solution procedures and convergence acceleration techniques. Hence, this method allows the development of stable, fully conservative differencing schemes for the solution of quite general inviscid flow problems. Results are presented for both subcritical and shocked supercritical internal flows. Comparisons are made with a standard time dependent solution algorithm.
Relaxation solution of the full Euler equations
NASA Technical Reports Server (NTRS)
Johnson, G. M.
1982-01-01
A numerical procedure for the relaxation solution of the full steady Euler equations is described. By embedding the Euler system in a second order surrogate system, central differencing may be used in subsonic regions while retaining matrix forms well suited to iterative solution procedures and convergence acceleration techniques. Hence, this method allows the development of stable, fully conservative differencing schemes for the solution of quite general inviscid flow problems. Results are presented for both subcritical and shocked supercritical internal flows. Comparisons are made with a standard time dependent solution algorithm. Previously announced in STAR as N82-24859
New Cosmological Solutions in Massive Gravity Theory
NASA Astrophysics Data System (ADS)
Pinho, S. S. A.; Pereira, S. H.; Mendonça, E. L.
2017-04-01
In this paper we present some new cosmological solutions in massive gravity theory. Some homogeneous and isotropic solutions correctly describe accelerated evolutions for the universe. The study was realized considering a specific form to the fiducial metric and found different functions and constant parameters of the theory that guarantee the conservation of the energy momentum tensor. Several accelerating cosmologies were found, all of them reproducing a cosmological constant term proportional to the graviton mass, with a de Sitter type solution for the scale factor. We have also verified that when the fiducial metric is close to the physical metric the solutions are absent, except for some specific open cases.
New interior solution describing relativistic fluid sphere
NASA Astrophysics Data System (ADS)
Newton Singh, Ksh; Pradhan, Narendra; Pant, Neeraj
2017-08-01
A new exact solution of embedding class I is presented for a relativistic anisotropic massive fluid sphere. The new exact solution satisfies Karmarkar condition, is well-behaved in all respects, and therefore is suitable for the modelling of superdense stars. Consequently, using this solution, we have studied in detail two compact stars, namely, XTE J1739-289 (strange star 1.51M_{⊙}, 10.9 km) and PSR J1614-2230 (neutron star 1.97M_{⊙}, 14 km). The solution also satisfies all energy conditions with the compactness parameter lying within the Buchdahl limit.
Classical Solution Thermodynamics: A Retrospective View.
ERIC Educational Resources Information Center
Van Ness, H. C.; Abbott, M. M.
1985-01-01
Examines topics related to classical solution thermodynamics, considering energy, enthalpy, and the Gibbs function. Applicable mathematical equations are introduced and discussed when appropriate. (JN)
Frankenstein's glue: transition functions for approximate solutions
NASA Astrophysics Data System (ADS)
Yunes, Nicolás
2007-09-01
Approximations are commonly employed to find approximate solutions to the Einstein equations. These solutions, however, are usually only valid in some specific spacetime region. A global solution can be constructed by gluing approximate solutions together, but this procedure is difficult because discontinuities can arise, leading to large violations of the Einstein equations. In this paper, we provide an attempt to formalize this gluing scheme by studying transition functions that join approximate analytic solutions together. In particular, we propose certain sufficient conditions on these functions and prove that these conditions guarantee that the joined solution still satisfies the Einstein equations analytically to the same order as the approximate ones. An example is also provided for a binary system of non-spinning black holes, where the approximate solutions are taken to be given by a post-Newtonian expansion and a perturbed Schwarzschild solution. For this specific case, we show that if the transition functions satisfy the proposed conditions, then the joined solution does not contain any violations to the Einstein equations larger than those already inherent in the approximations. We further show that if these functions violate the proposed conditions, then the matter content of the spacetime is modified by the introduction of a matter shell, whose stress energy tensor depends on derivatives of these functions.
Supersymmetric Ito equation: Bosonization and exact solutions
Ren Bo; Yu Jun; Lin Ji
2013-04-15
Based on the bosonization approach, the N=1 supersymmetric Ito (sIto) system is changed to a system of coupled bosonic equations. The approach can effectively avoid difficulties caused by intractable fermionic fields which are anticommuting. By solving the coupled bosonic equations, the traveling wave solutions of the sIto system are obtained with the mapping and deformation method. Some novel types of exact solutions for the supersymmetric system are constructed with the solutions and symmetries of the usual Ito equation. In the meanwhile, the similarity reduction solutions of the model are also studied with the Lie point symmetry theory.
Solution for Depositing an Electroless Cobalt Alloy.
SOLUTIONS(MIXTURES), *ELECTROLESS PLATING), (*PATENTS, ELECTROLESS PLATING), (*COBALT ALLOYS, ELECTROLESS PLATING), ADDITIVES, SODIUM COMPOUNDS... TUNGSTATES , POTASSIUM COMPOUNDS, NICKEL COMPOUNDS, SULFATES, THIOUREA, MAGNETIC PROPERTIES
Classical Solution Thermodynamics: A Retrospective View.
ERIC Educational Resources Information Center
Van Ness, H. C.; Abbott, M. M.
1985-01-01
Examines topics related to classical solution thermodynamics, considering energy, enthalpy, and the Gibbs function. Applicable mathematical equations are introduced and discussed when appropriate. (JN)
PREPARATION OF HEMOGLOBIN SOLUTIONS FOR INTRAVENOUS INFUSION
Hamilton, Paul B.; Farr, Lee E.; Hiller, Alma; Van Slyke, Donald D.
1947-01-01
A procedure has been detailed for the preparation of sterile non-pyrogenic solutions of oxyhemoglobin which have the approximate protein content and electrolyte composition of plasma. Large volumes of solution can be rapidly prepared, with 95 to 98 per cent of the hemoglobin in the active form capable of combining with oxygen. The solutions contain no particulate matter; 95 per cent of total blood lipids are removed. Solutions stored at 4°C. showed no conversion of hemoglobin to methemoglobin over a period of 2½ months; over a 6 month period a small and variable amount of methemoglobin may be formed. PMID:19871690
THE PREPARATION AND STERILIZATION OF OPHTHALMIC SOLUTIONS
Hogan, Michael J.
1949-01-01
Ophthalmic solutions should be prepared and preserved according to whether they are to be used in surgical procedures, in the clinic or office, or by the patient at home. There is an optimum pH level at which the solutions of individual drugs should be buffered in order to obtain the maximum efficiency and stability. Deterioration of the drugs used is greatly diminished when they are dispensed at the proper pH. Quaternary ammonium chloride solutions in proper strength have been shown to be adequate for the preservation of ophthalmic solutions. PMID:15408108
Terahertz absorption of lysozyme in solution
NASA Astrophysics Data System (ADS)
Martin, Daniel R.; Matyushov, Dmitry V.
2017-08-01
Absorption of radiation by solution is described by its frequency-dependent dielectric function and can be viewed as a specific application of the dielectric theory of solutions. For ideal solutions, the dielectric boundary-value problem separates the polar response into the polarization of the void in the liquid, created by the solute, and the response of the solute dipole. In the case of a protein as a solute, protein nuclear dynamics do not project on significant fluctuations of the dipole moment in the terahertz domain of frequencies and the protein dipole can be viewed as dynamically frozen. Absorption of radiation then reflects the interfacial polarization. Here we apply an analytical theory and computer simulations to absorption of radiation by an ideal solution of lysozyme. Comparison with the experiment shows that Maxwell electrostatics fails to describe the polarization of the protein-water interface and the "Lorentz void," which does not anticipate polarization of the interface by the external field (no surface charges), better represents the data. An analytical theory for the slope of the solution absorption against the volume fraction of the solute is formulated in terms of the cavity field response function. It is calculated from molecular dynamics simulations in good agreement with the experiment. The protein hydration shell emerges as a separate sub-ensemble, which, collectively, is not described by the standard electrostatics of dielectrics.
Terahertz absorption of lysozyme in solution.
Martin, Daniel R; Matyushov, Dmitry V
2017-08-28
Absorption of radiation by solution is described by its frequency-dependent dielectric function and can be viewed as a specific application of the dielectric theory of solutions. For ideal solutions, the dielectric boundary-value problem separates the polar response into the polarization of the void in the liquid, created by the solute, and the response of the solute dipole. In the case of a protein as a solute, protein nuclear dynamics do not project on significant fluctuations of the dipole moment in the terahertz domain of frequencies and the protein dipole can be viewed as dynamically frozen. Absorption of radiation then reflects the interfacial polarization. Here we apply an analytical theory and computer simulations to absorption of radiation by an ideal solution of lysozyme. Comparison with the experiment shows that Maxwell electrostatics fails to describe the polarization of the protein-water interface and the "Lorentz void," which does not anticipate polarization of the interface by the external field (no surface charges), better represents the data. An analytical theory for the slope of the solution absorption against the volume fraction of the solute is formulated in terms of the cavity field response function. It is calculated from molecular dynamics simulations in good agreement with the experiment. The protein hydration shell emerges as a separate sub-ensemble, which, collectively, is not described by the standard electrostatics of dielectrics.
Processing Solutions for Big Data in Astronomy
NASA Astrophysics Data System (ADS)
Fillatre, L.; Lepiller, D.
2016-09-01
This paper gives a simple introduction to processing solutions applied to massive amounts of data. It proposes a general presentation of the Big Data paradigm. The Hadoop framework, which is considered as the pioneering processing solution for Big Data, is described together with YARN, the integrated Hadoop tool for resource allocation. This paper also presents the main tools for the management of both the storage (NoSQL solutions) and computing capacities (MapReduce parallel processing schema) of a cluster of machines. Finally, more recent processing solutions like Spark are discussed. Big Data frameworks are now able to run complex applications while keeping the programming simple and greatly improving the computing speed.
Ibuprofen photodegradation in aqueous solutions.
Iovino, Pasquale; Chianese, Simeone; Canzano, Silvana; Prisciandaro, Marina; Musmarra, Dino
2016-11-01
The advanced treatment of polluted liquid streams containing traces of pharmaceutical compounds is a major issue, since more and more effluents from pharma labs and wastewaters containing the excretions of medically treated humans and animals are discharged in the conventional wastewater treatment plants without previous effective treatments. Ibuprofen is a widely used non-steroidal anti-inflammatory drug (NSAID), which explains why it is found in wastewaters so often. In this paper, the removal of IBP from simulated water streams was investigated by using a lab-scale experimental device, consisting of a batch reactor equipped with a lamp emitting monochromatic UV light at a fixed wavelength (254 nm) and various intensities. Three sets of experiments were carried out: the first to study IBP concentration as a function of time, at different volumes of treated solutions (V = 10-30 mL); the second to explore the effect of pH on IBP degradation as a function of time (pH = 2.25-8.25) and the third to evaluate the effect of different UV light intensities on IBP degradation (E = 100-400 mJ m(-2)). The IBP initial concentration (IBP 0) was varied in the range 30-60 mg L(-1). The results obtained show that the concentration of IBP decreases along with treatment time, with a negative effect of the treated volume, i.e. smaller volumes, such as lower liquid heights, are more easily degraded. Moreover, the higher the pH, the better the IBP degradation; actually, when pH increases from 2.25 to 6.6 and 8.25, the IBP concentration, after an hour of treatment, decreases respectively to 45, 34 and 27 % of its initial value. In addition, as the intensity of light increases from 100 to 400 mJ m(-2), the IBP concentration decreases to 34 % of its initial value. A reaction scheme is put forward in the paper, which well describes the effects of volume, pH and light intensity on the IBP degradation measured experimentally. Moreover, the IBP degradation by-products have
New solutions for the confined horizontal aquifer
NASA Astrophysics Data System (ADS)
Akylas, Evangelos; Gravanis, Elias
2016-04-01
The Boussinesq equation is a dynamical equation for the free surface of saturated subsurface flows over an impervious bed. Boussinesq equation is non-linear. The non-linearity comes from the reduction of the dimensionality of the problem: The flow is assumed to be vertically homogeneous, therefore the flow rate through a cross section of the flow is proportional to the free surface height times the hydraulic gradient, which is assumed to be equal to the slope of the free surface. In the present work we consider the case of the subsurface flow with horizontal bed. This is a case with an infinite Henderson and Wooding parameter, that is, it is the limiting case where the non-linear term is present in the Boussinesq equation while the linear spatial derivative term vanishes. Nonetheless, no analogue of the kinematic wave exists in this case as there is no exact solution for the build-up phase. Neither is there an exact recession-phase solution that holds in early times, as the Boussinesq separable solution is actually an asymptotic solution for large times. We construct approximate solutions for the horizontal aquifer which utilize directly the dynamical content of the non-linear Boussinesq equation. The approximate character of the solution lies in the fact that we start with a pre-supposed form for the solution, an educated guess, based on the nature of the initial condition as well as empirical observations from the numerical solution of the problem. The forms we shall use are power series of the location variable x along the bed with time-dependent coefficients. The series are not necessarily analytic. The boundary conditions are incorporated in the structure of the series from the beginning. The time-dependent coefficients are then determined by applying the Boussinesq equation and its spatial derivatives at the end-points of the aquifer. The forms are chosen also on the basis of their solubility; we would like to be able to construct explicitly the approximate
Supersaturated Electrolyte Solutions: Theory and Experiment
NASA Technical Reports Server (NTRS)
Izmailov, Alexander F.; Myerson, Allan S.; Na, Han-Soo
1995-01-01
Highly supersaturated electrolyte solutions can be prepared and studied employing an electrodynamic levitator trap (ELT) technique. The ELT technique involves containerless suspension of a microdroplet thus eliminating dust, dirt, and container walls which normally cause heterogeneous nucleation. This allows very high supersaturations to be achieved. A theoretical study of the experimental results obtained for the water activity in microdroplets of various electrolyte solutions is based on the development of the Cahn-Hilliard formalism for electrolyte solutions. In the approach suggested the metastable state for electrolyte solutions is described in terms of the conserved order parameter omega(r,t) associated with fluctuations of the mean solute concentration n(sub 0). Parameters of the corresponding Ginzburg-Landau free energy functional which defines the dynamics of metastable state relaxation are determined and expressed through the experimentally measured quantities. A correspondence of 96-99 % between theory and experiment for all solutions studied was achieved and allowed the determination of an analytical expression for the spinodal concentration n(sub spin), and its calculation for various electrolyte solutions at 298 K. The assumption that subcritical solute clusters consist of the electrically neutral Bjerrum pairs has allowed both analytical and numerical investigation of the number-size N(sub c) of nucleation monomers (aggregates of the Bjerrum pairs) which are elementary units of the solute critical clusters. This has also allowed estimations for the surface tension Alpha, and equilibrium bulk energy Beta per solute molecule in the nucleation monomers. The dependence of these properties on the temperature T and on the solute concentration n(sub 0) through the entire metastable zone (from saturation concentration n(sub sat) to spinodal n(sub spin) is examined. It has been demonstrated that there are the following asymptotics: N(sub c), = I at spinodal
Détection et exaltation de la luminescence de molécules biologiques individuelles en solution
NASA Astrophysics Data System (ADS)
Etienne, E.; Lenne, P. F.; Rigneault, H.
2002-06-01
La Spectroscopie de Corrélation de Fluorescence (FCS) est une technique d'analyse statistique des fluctuations de luminescence produites par des molécules fluorescentes diffusant librement dans un volume de collection de quelque μm^3. Une limitation fondamentale de la technique provient de l'ouverture numérique limitée des systèmes optiques conventionnels qui ne collectent qu'une faible partie des photons émis. Nous présentons des résultats relatifs à l'augmentation du nombre de photons collectés en utilisant le concept du contrôle de l'émission spontanée par des structures photoniques de type miroir diélectrique.
Thermodynamic properties of potassium chloride aqueous solutions
NASA Astrophysics Data System (ADS)
Zezin, Denis; Driesner, Thomas
2017-04-01
Potassium chloride is a ubiquitous salt in natural fluids, being the second most abundant dissolved salt in many geological aqueous solutions after sodium chloride. It is a simple solute and strong electrolyte easily dissociating in water, however the thermodynamic properties of KCl aqueous solutions were never correlated with sufficient accuracy for a wide range of physicochemical conditions. In this communication we propose a set of parameters for a Pitzer-type model which allows calculation of all necessary thermodynamic properties of KCl solution, namely excess Gibbs free energy and derived activity coefficient, apparent molar enthalpy, heat capacity and volume, as well as osmotic coefficient and activity of water in solutions. The system KCl-water is one of the best studied aqueous systems containing electrolytes. Although extensive experimental data were collected for thermodynamic properties of these solutions over the years, the accurate volumetric data became available only recently, thus making possible a complete thermodynamic formulation including a pressure dependence of excess Gibbs free energy and derived properties of the KCl-water liquids. Our proposed model is intended for calculation of major thermodynamic properties of KCl aqueous solutions at temperatures ranging from freezing point of a solution to 623 K, pressures ranging from saturated water vapor up to 150 MPa, and concentrations up to the salt saturation. This parameterized model will be further implemented in geochemical software packages and can facilitate the calculation of aqueous equilibrium for reactive transport codes.
Solving Solutions: Exploring Unknowns through Chemistry.
ERIC Educational Resources Information Center
Burns, John; Yoshina, Granville; Goodding, Debbie; Streitberger, Eric
2000-01-01
Presents a chemistry activity that introduces students to one type of chemical bond by developing the integer operation concept of zero pairs. Leads to an activity of combining drops of 0.3 molar solutions to form six different colored precipitates from five solutions. (ASK)
Power Series Solution to the Pendulum Equation
ERIC Educational Resources Information Center
Benacka, Jan
2009-01-01
This note gives a power series solution to the pendulum equation that enables to investigate the system in an analytical way only, i.e. to avoid numeric methods. A method of determining the number of the terms for getting a required relative error is presented that uses bigger and lesser geometric series. The solution is suitable for modelling the…
SEPARATION OF RUTHENIUM FROM AQUEOUS SOLUTIONS
Beederman, M.; Vogler, S.; Hyman, H.H.
1959-07-14
The separation of rathenium from a rathenium containing aqueous solution is described. The separation is accomplished by adding sodium nitrite, silver nitrate and ozone to the ruthenium containing aqueous solution to form ruthenium tetroxide and ihen volatilizing off the ruthenium tetroxide.
Solution Kinetics Database on the Web
National Institute of Standards and Technology Data Gateway
SRD 40 NDRL/NIST Solution Kinetics Database on the Web (Web, free access) Data for free radical processes involving primary radicals from water, inorganic radicals and carbon-centered radicals in solution, and singlet oxygen and organic peroxyl radicals in various solvents.
ENGINEERING BULLETIN: AIR STRIPPING OF AQUEOUS SOLUTIONS
Air striding is a means to transfer contaminants from aqueous solutions to air. ontaminants are not destroyed by air stripping but are physically separated from the aqueous solutions. ontaminant vapors are transferred into the air stream and, if necessary, can be treated by incin...
Rheological characterization of nephila spidroin solution.
Chen, Xin; Knight, David P; Vollrath, Fritz
2002-01-01
We report the results of an investigation into the rheology of solutions of natural spider silk dope (spinning solution). We demonstrate that dilute dope solutions showed only shear thinning as the shear rate increased while more concentrated solutions showed an initial shear thinning followed by a shear thickening and a subsequent decline in viscosity. The critical shear rate for shear thickening depended on dope concentration and was very low in concentrated solutions. This helps to explain how spiders are able to spin silk at very low draw rates and why they use a very concentrated dope solution. We also show that the optimum shear rate for shear thickening in moderately concentrated solutions occurred at pH 6.3 close to the observed pH at the distal end of the spider's spinning duct. Finally, we report that the addition of K(+) ions to dilute dope solutions produced a spontaneous formation of nanofibrils that subsequently aggregated and precipitated. This change was not seen after the addition of other common cations. Taken together, these observations support the hypothesis that the secretion of H(+) and K(+) by the spider's duct together with moderate strain rates produced during spinning induce a phase separation in the silk dope in which the silk protein (spidroin) molecules are converted into insoluble nanofibrils.
The Pizza Problem: A Solution with Sequences
ERIC Educational Resources Information Center
Shafer, Kathryn G.; Mast, Caleb J.
2008-01-01
This article addresses the issues of coaching and assessing. A preservice middle school teacher's unique solution to the Pizza problem was not what the professor expected. The student's solution strategy, based on sequences and a reinvention of Pascal's triangle, is explained in detail. (Contains 8 figures.)
Power Series Solution to the Pendulum Equation
ERIC Educational Resources Information Center
Benacka, Jan
2009-01-01
This note gives a power series solution to the pendulum equation that enables to investigate the system in an analytical way only, i.e. to avoid numeric methods. A method of determining the number of the terms for getting a required relative error is presented that uses bigger and lesser geometric series. The solution is suitable for modelling the…
Electroosmotic flow hysteresis for dissimilar ionic solutions
Lim, An Eng; Lam, Yee Cheong
2015-01-01
Electroosmotic flow (EOF) with two or more fluids is commonly encountered in various microfluidics applications. However, no investigation has hitherto been conducted to investigate the hysteretic or flow direction-dependent behavior during the displacement flow of solutions with dissimilar ionic species. In this investigation, electroosmotic displacement flow involving dissimilar ionic solutions was studied experimentally through a current monitoring method and numerically through finite element simulations. The flow hysteresis can be characterized by the turning and displacement times; turning time refers to the abrupt gradient change of current-time curve while displacement time is the time for one solution to completely displace the other solution. Both experimental and simulation results illustrate that the turning and displacement times for a particular solution pair can be directional-dependent, indicating that the flow conditions in the microchannel are not the same in the two different flow directions. The mechanics of EOF hysteresis was elucidated through the theoretical model which includes the ionic mobility of each species, a major governing parameter. Two distinct mechanics have been identified as the causes for the EOF hysteresis involving dissimilar ionic solutions: the widening/sharpening effect of interfacial region between the two solutions and the difference in ion concentration distributions (and thus average zeta potentials) in different flow directions. The outcome of this investigation contributes to the fundamental understanding of flow behavior in microfluidic systems involving solution pair with dissimilar ionic species. PMID:25945139
Neutron scattering study of dilute supercritical solutions
Cochran, H.D.; Wignall, G.D.; Shah, V.M.; Londono, J.D.; Bienkowski, P.R.
1994-10-01
Dilute solutions in supercritical solvents exhibit interesting microstructures that are related to their dramatic macroscopic behavior. In typical attractive solutions, solutes are believed to be surrounded by clusters of solvent molecules, and solute molecules are believed to congregate in the vicinity of one another. Repulsive solutions, on the other hand, exhibit a local region of reduced solvent density around the solute with solute-solute congregation. Such microstructures influence solubility, partial molar volume, reaction kinetics, and many other properties. We have undertaken to observe these interesting microstructures directly by neutron scattering experiments on dilute noble gas systems including Ar. The three partial structure factors for such systems and the corresponding pair correlation functions can be determined by using the isotope substitution technique. The systems studied are uniquely suited for our objectives because of the large coherent neutron scattering length of the isotope {sup 36}Ar and because of the accurate potential energy functions that are available for use in molecular simulations and theoretical calculations to be compared with the scattering results. We will describe our experiment, the unique apparatus we have built for it, and the neutron scattering results from our initial allocations of beam time. We will also describe planned scattering experiments to follow those with noble gases, including study of long-chain molecules in supercritical solvents. Such studies will involve hydrocarbon mixtures with and without deuteration to provide contrast.
ADSORPTION OF CERIUM VALUES FROM AQUEOUS SOLUTIONS
Roberts, F.P.
1963-08-13
Cerium can be removed from aqueous nitric acid (2 to 13 M) solutions by passing the latter over a PbO/sub 2/-containing anion exchange resin. The cerium is taken up by the resin, while any lanthanides, yttrium, and strontium present remain in the solution. (AEC)
RHEOLOGY OF CONCENTRATED SOLUTIONS OF HYPERBRANCHED POLYESTERS
The solution rheology of different generations of hyperbranched polyesters in N-methyl-2- pyrrolidinone (NMP) solvent was examined in this study. The solutions exhibited Newtonian behavior over a wide range of polyester concentrations. Also, the relative viscosities of poly(amido...
Optimal solutions of unobservable orbit determination problems
NASA Astrophysics Data System (ADS)
Cicci, David A.; Tapley, Byron D.
1988-12-01
The method of data augmentation, in the form ofa priori covariance information on the reference solution, as a means to overcome the effects of ill-conditioning in orbit determination problems has been investigated. Specifically, for the case when ill-conditioning results from parameter non-observability and an appropriatea priori covariance is unknown, methods by which thea priori covariance is optimally chosen are presented. In problems where an inaccuratea priori covariance is provided, the optimal weighting of this data set is obtained. The feasibility of these ‘ridge-type’ solution methods is demonstrated by their application to a non-observable gravity field recovery simulation. In the simulation, both ‘ridge-type’ and conventional solutions are compared. Substantial improvement in the accuracy of the conventional solution is realized by the use of these ridge-type solution methods. The solution techniques presented in this study are applicable to observable, but ill-conditioned problems as well as the unobservable problems directly addressed. For the case of observable problems, the ridge-type solutions provide an improvement in the accuracy of the ordinary least squares solutions.
Schwarzschild solution in brane induced gravity
Gabadadze, Gregory; Iglesias, Alberto
2005-10-15
The metric of a Schwarzschild solution in brane induced gravity in five dimensions is studied. We find a nonperturbative solution for which an exact expression on the brane is obtained. We also find a linearized solution in the bulk and argue that a nonsingular exact solution in the entire space should exist. The exact solution on the brane is highly nontrivial as it interpolates between different distance scales. This part of the metric is enough to deduce an important property--the Arnowitt-Deser-Misner canonical formalism (ADM) mass of the solution is suppressed compared to the bare mass of a static source. This screening of the mass is due to nonlinear interactions which give rise to a nonzero curvature outside the source. The curvature extends away from the source to a certain macroscopic distance that coincides with the would-be strong interaction scale. The very same curvature shields the source from strong coupling effects. The four-dimensional law of gravity, including the correct tensorial structure, is recovered at observable distances. We find that the solution has no van Dam-Veltman-Zakharov discontinuity and show that the gravitational field on the brane is always weak, in spite of the fact that the solution is nonperturbative.
On the Preparation of Buffer Solutions.
ERIC Educational Resources Information Center
Thomson, Bruce M.; Kessick, Michael A.
1981-01-01
Presents a method, suitable for use on programmable calculators, which allows calculation of the pH and ionic strength (I) of a mixed solution of salts of an acid or amounts necessary to produce a solution of a particular pH and I. Includes limitations when using the calculations described. (SK)
RHEOLOGY OF CONCENTRATED SOLUTIONS OF HYPERBRANCHED POLYESTERS
The solution rheology of different generations of hyperbranched polyesters in N-methyl-2- pyrrolidinone (NMP) solvent was examined in this study. The solutions exhibited Newtonian behavior over a wide range of polyester concentrations. Also, the relative viscosities of poly(amido...
Sensitivities of Soap Solutions in Leak Detection
NASA Technical Reports Server (NTRS)
Stuck, D.; Lam, D. Q.; Daniels, C.
1985-01-01
Document describes method for determining minimum leak rate to which soap-solution leak detectors sensitive. Bubbles formed at smaller leak rates than previously assumed. In addition to presenting test results, document discusses effects of joint-flange configurations, properties of soap solutions, and correlation of test results with earlier data.
An Enlarged Profile of Uremic Solutes
Tanaka, Hisae; Sirich, Tammy L.; Plummer, Natalie S.; Weaver, Daniel S.; Meyer, Timothy W.
2015-01-01
Better knowledge of the uremic solutes that accumulate when the kidneys fail could lead to improved renal replacement therapy. This study employed the largest widely available metabolomic platform to identify such solutes. Plasma and plasma ultrafiltrate from 6 maintenance hemodialysis (HD) patients and 6 normal controls were first compared using a platform combining gas and liquid chromatography with mass spectrometry. Further studies compared plasma from 6 HD patients who had undergone total colectomy and 9 with intact colons. We identified 120 solutes as uremic including 48 that had not been previously reported to accumulate in renal failure. Combination of the 48 newly identified solutes with those identified in previous reports yielded an extended list of more than 270 uremic solutes. Among the solutes identified as uremic in the current study, 9 were shown to be colon-derived, including 6 not previously identified as such. Literature search revealed that many uremic phenyl and indole solutes, including most of those shown to be colon-derived, come from plant foods. Some of these compounds can be absorbed directly from plant foods and others are produced by colon microbial metabolism of plant polyphenols that escape digestion in the small intestine. A limitation of the metabolomic method was that it underestimated the elevation in concentration of uremic solutes which were measured using more quantitative assays. PMID:26317986
The Pizza Problem: A Solution with Sequences
ERIC Educational Resources Information Center
Shafer, Kathryn G.; Mast, Caleb J.
2008-01-01
This article addresses the issues of coaching and assessing. A preservice middle school teacher's unique solution to the Pizza problem was not what the professor expected. The student's solution strategy, based on sequences and a reinvention of Pascal's triangle, is explained in detail. (Contains 8 figures.)
Ammonia Solubility in High Concentration Salt Solutions
HEDENGREN, D.C.
2000-02-01
Solubility data for ammonia in water and various dilute solutions are abundant in the literature. However, there is a noticeable lack of ammonia solubility data for high salt, basic solutions of various mixtures of salts including those found in many of the Hanford Washington underground waste tanks. As a result, models based on solubility data for dilute salt solutions have been used to extrapolate to high salt solutions. These significant extrapolations need to be checked against actual laboratory data. Some indirect vapor measurements have been made. A more direct approach is to determine the ratio of solubility of ammonia in water to its solubility in high salt solutions. In various experiments, pairs of solutions, one of which is water and the other a high salt solution, are allowed to come to equilibrium with a common ammonia vapor pressure. The ratio of concentrations of ammonia in the two solutions is equal to the ratio of the respective ammonia solubilities (Henry's Law constants) at a given temperature. This information can then be used to refine the models that predict vapor space compositions of ammonia. Ammonia at Hanford is of concern because of its toxicity in the environment and its contribution to the flammability of vapor space gas mixtures in waste tanks.
Sensitivities of Soap Solutions in Leak Detection
NASA Technical Reports Server (NTRS)
Stuck, D.; Lam, D. Q.; Daniels, C.
1985-01-01
Document describes method for determining minimum leak rate to which soap-solution leak detectors sensitive. Bubbles formed at smaller leak rates than previously assumed. In addition to presenting test results, document discusses effects of joint-flange configurations, properties of soap solutions, and correlation of test results with earlier data.
Polynomial solutions of nonlinear integral equations
NASA Astrophysics Data System (ADS)
Dominici, Diego
2009-05-01
We analyze the polynomial solutions of a nonlinear integral equation, generalizing the work of Bender and Ben-Naim (2007 J. Phys. A: Math. Theor. 40 F9, 2008 J. Nonlinear Math. Phys. 15 (Suppl. 3) 73). We show that, in some cases, an orthogonal solution exists and we give its general form in terms of kernel polynomials.
METHOD AND APPARATUS FOR CALCINING SALT SOLUTIONS
Lawroski, S.; Jonke, A.A.; Taecker, R.G.
1961-10-31
A method is given for converting uranyl nitrate solution into solid UO/ sub 3/, The solution is sprayed horizontally into a fluidized bed of UO/sub 3/ particles at 310 to 350 deg C by a nozzle of the coaxial air jet type at about 26 psig, Under these conditions the desired conversion takes place, and caking in the bed is avoided.
Urban infrastructure choices structure climate solutions
NASA Astrophysics Data System (ADS)
Creutzig, Felix; Agoston, Peter; Minx, Jan C.; Canadell, Josep G.; Andrew, Robbie M.; Quéré, Corinne Le; Peters, Glen P.; Sharifi, Ayyoob; Yamagata, Yoshiki; Dhakal, Shobhakar
2016-12-01
Cities are becoming increasingly important in combatting climate change, but their overall role in global solution pathways remains unclear. Here we suggest structuring urban climate solutions along the use of existing and newly built infrastructures, providing estimates of the mitigation potential.
On Browne's Solution for Oblique Procrustes Rotation
ERIC Educational Resources Information Center
Cramer, Elliot M.
1974-01-01
A form of Browne's (1967) solution of finding a least squares fit to a specified factor structure is given which does not involve solution of an eigenvalue problem. It suggests the possible existence of a singularity, and a simple modification of Browne's computational procedure is proposed. (Author/RC)
ENGINEERING BULLETIN: AIR STRIPPING OF AQUEOUS SOLUTIONS
Air striding is a means to transfer contaminants from aqueous solutions to air. ontaminants are not destroyed by air stripping but are physically separated from the aqueous solutions. ontaminant vapors are transferred into the air stream and, if necessary, can be treated by incin...
Solving Solutions: Exploring Unknowns through Chemistry.
ERIC Educational Resources Information Center
Burns, John; Yoshina, Granville; Goodding, Debbie; Streitberger, Eric
2000-01-01
Presents a chemistry activity that introduces students to one type of chemical bond by developing the integer operation concept of zero pairs. Leads to an activity of combining drops of 0.3 molar solutions to form six different colored precipitates from five solutions. (ASK)
Disorder solutions of lattice spin models
NASA Astrophysics Data System (ADS)
Batchelor, M. T.; van Leeuwen, J. M. J.
1989-01-01
It is shown that disorder solutions, which have been obtained by different methods, follow from a simple decimation method. The method is put in general form and new disorder solutions are constructed for the Blume-Emery-Griffiths model on a triangular lattice and for Potts and Ising models on square and fcc lattices.
Durable Solutions for Developing Country Refugees.
ERIC Educational Resources Information Center
Stein, Barry N.
1986-01-01
There are only three durable solutions to the refugee problem--voluntary repatriation, local settlement, and third-country resettlement--and all depend on political will, diplomacy, and statesmanship. It is important to remember, however, that humanitarian concerns must outweigh costs consciousness when durable solutions are sought. (Author/GC)
Clean Energy Solutions Center Services (Vietnamese Translation)
2016-03-01
This is a Vietnamese translation of the Clean Energy Solutions Center fact sheet. The Solutions Center offers no-cost expert policy assistance, webinars and training forums, clean energy policy reports, data, and tools provided in partnership with more than 35 leading international and regional clean energy organizations.
Clean Energy Solutions Center Services (French Translation)
2016-03-01
This is a French translation of the Clean Energy Solutions Center fact sheet. The Solutions Center offers no-cost expert policy assistance, webinars and training forums, clean energy policy reports, data, and tools provided in partnership with more than 35 leading international and regional clean energy organizations.
Clean Energy Solutions Center Services (Portuguese Translation)
2016-03-01
This is a Portuguese translation of the Clean Energy Solutions Center Services fact sheet. The Solutions Center offers no-cost expert policy assistance, webinars and training forums, clean energy policy reports, data, and tools provided in partnership with more than 35 leading international and regional clean energy organizations.
Clean Energy Solutions Center Services (Chinese Translation)
2016-03-01
This is a Mandarin translation of the Clean Energy Solutions Center fact sheet. The Solutions Center offers no-cost expert policy assistance, webinars and training forums, clean energy policy reports, data, and tools provided in partnership with more than 35 leading international and regional clean energy organizations.
Clean Energy Solutions Center Services (Arabic Translation)
2016-03-01
This is an Arabic translation of the Clean Energy Solutions Center fact sheet. The Solutions Center offers no-cost expert policy assistance, webinars and training forums, clean energy policy reports, data, and tools provided in partnership with more than 35 leading international and regional clean energy organizations.
On the Preparation of Buffer Solutions.
ERIC Educational Resources Information Center
Thomson, Bruce M.; Kessick, Michael A.
1981-01-01
Presents a method, suitable for use on programmable calculators, which allows calculation of the pH and ionic strength (I) of a mixed solution of salts of an acid or amounts necessary to produce a solution of a particular pH and I. Includes limitations when using the calculations described. (SK)
Approximate solutions to fractional subdiffusion equations
NASA Astrophysics Data System (ADS)
Hristov, J.
2011-03-01
The work presents integral solutions of the fractional subdiffusion equation by an integral method, as an alternative approach to the solutions employing hypergeometric functions. The integral solution suggests a preliminary defined profile with unknown coefficients and the concept of penetration (boundary layer). The prescribed profile satisfies the boundary conditions imposed by the boundary layer that allows its coefficients to be expressed through its depth as unique parameter. The integral approach to the fractional subdiffusion equation suggests a replacement of the real distribution function by the approximate profile. The solution was performed with Riemann-Liouville time-fractional derivative since the integral approach avoids the definition of the initial value of the time-derivative required by the Laplace transformed equations and leading to a transition to Caputo derivatives. The method is demonstrated by solutions to two simple fractional subdiffusion equations (Dirichlet problems): 1) Time-Fractional Diffusion Equation, and 2) Time-Fractional Drift Equation, both of them having fundamental solutions expressed through the M-Wright function. The solutions demonstrate some basic issues of the suggested integral approach, among them: a) Choice of the profile, b) Integration problem emerging when the distribution (profile) is replaced by a prescribed one with unknown coefficients; c) Optimization of the profile in view to minimize the average error of approximations; d) Numerical results allowing comparisons to the known solutions expressed to the M-Wright function and error estimations.
[Osmolarity of solutions used in nebulization].
Portel, L; Tunon de Lara, J M; Vernejoux, J M; Weiss, I; Taytard, A
1998-04-01
Inhaled medications are widely used in patients suffering from bronchial diseases. Beside their pharmacological properties, nebulised solutions have physico-chemical characteristics that can alter bronchial reactivity. Non-isotonic solutions can induce a bronchial hyperresponsiveness and/or a severe bronchonconstriction. Nevertheless, multiple drugs are used for nebulisation despite their unknown osmolarity. The aim of this study was to measure the tonicity of drug solutions commonly used for nebulisation in patients suffering from bronchial disease. Drug solutions were prepared either according to manufacturer recommendations or by diluting the stock in 5 ml of NaCl (0.9%) or H2CO3 (0.14%). Although bronchodilatator solutions (i.e. salbutamol, terbulatine, ipratropium bromide) were nearly isotonic, some drugs prepared for nebulisation had either a very high (e.g. mesna, netilmicine) or a very low (e.g. gomenol, sodium cromoglycate) tonicity. These values may be responsible for bronchoconstriction. Some hypertonic solutions, prepared with drugs such as acetylcytein or netilmycin, are not commercialised for nebulisation but are commonly used for aerosol therapy. In addition, solutions initially isotonic could become significantly hypertonic towards the end of nebulisation. Taken together, these results suggest that non-isotonic solutions should be used with caution specially in patients with bronchial hyperresponsiveness, even when aerosol therapy is prescribed for upper airways.
PROCESSES OF RECLAIMING URANIUM FROM SOLUTIONS
Zumwalt, L.R.
1959-02-10
A process is described for reclaiming residual enriched uranium from calutron wash solutions containing Fe, Cr, Cu, Ni, and Mn as impurities. The solution is adjusted to a pH of between 2 and 4 and is contacted with a metallic reducing agent, such as iron or zinc, in order to reduce the copper to metal and thereby remove it from the solution. At the same time the uranium present is reduced to the uranous state The solution is then contacted with a precipitate of zinc hydroxide or barium carbonate in order to precipitate and carry uranium, iron, and chromium away from the nickel and manganese ions in the solution. The uranium is then recovered fronm this precipitate.
SEPARATION OF RUTHENIUM FROM AQUEOUS SOLUTIONS
Callis, C.F.; Moore, R.L.
1959-09-01
>The separation of ruthenium from aqueous solutions containing uranium plutonium, ruthenium, and fission products is described. The separation is accomplished by providing a nitric acid solution of plutonium, uranium, ruthenium, and fission products, oxidizing plutonium to the hexavalent state with sodium dichromate, contacting the solution with a water-immiscible organic solvent, such as hexone, to extract plutonyl, uranyl, ruthenium, and fission products, reducing with sodium ferrite the plutonyl in the solvent phase to trivalent plutonium, reextracting from the solvent phase the trivalent plutonium, ruthenium, and some fission products with an aqueous solution containing a salting out agent, introducing ozone into the aqueous acid solution to oxidize plutonium to the hexavalent state and ruthenium to ruthenium tetraoxide, and volatizing off the ruthenium tetraoxide.
Reference electrode for strong oxidizing acid solutions
Rigdon, Lester P.; Harrar, Jackson E.; Bullock, Sr., Jack C.; McGuire, Raymond R.
1990-01-01
A reference electrode for the measurement of the oxidation-reduction potentials of solutions is especially suitable for oxidizing solutions such as highly concentrated and fuming nitric acids, the solutions of nitrogen oxides, N.sub.2 O.sub.4 and N.sub.2 O.sub.5, in nitric acids. The reference electrode is fabricated of entirely inert materials, has a half cell of Pt/Ce(IV)/Ce(III)/70 wt. % HNO.sub.3, and includes a double-junction design with an intermediate solution of 70 wt. % HNO.sub.3. The liquid junctions are made from Corning No. 7930 glass for low resistance and negligible solution leakage.
Electrical conductivity of acidic chloride solutions
NASA Astrophysics Data System (ADS)
Majima, Hiroshi; Peters, Ernest; Awakura, Yasuhiro; Park, Sung Kook; Aoki, Masami
1988-02-01
The electrical conductivities of aqueous solutions in the system HCl-MCln (where M = K, Na, Mg, Ni, or Cd) were measured at different temperatures. The equivalent electrical conductivity of H+ was calculated on the basis of simple assumptions for these solutions, and show an inverse relationship with water activity in these solutions. The results obtained by varying temperatures, solute ratios, and ionic strength on the electrical conductivity were found to be consistent with a proton jump mechanism for the H+ ion, where the activity of water is the most significant parameter affecting its equivalent conductance, and a viscous (Stokes’ law) drag mechanism (i.e., Walden’s rule is obeyed) for other ions found in acidic solutions.
Radiation Driven Wind Solutions and Applications
NASA Astrophysics Data System (ADS)
Curé, M.
2016-11-01
The standard modified-CAK equation of motion is a non-linear differential equation that possesses many singular points and therefore many solutions. Apart from the standard solution, we have found three other physical solutions: i) when the rotational velocity is higher than 3/4 of the critical rotational speed; ii) when there is a high ionization change throughout the wind; and iii) when the k line force parameter is very high (k is the fraction of the total stellar flux which would be blocked in the photosphere if all lines were optically thick). We also show some applications of these solutions, e.g., the wind of a B[e] supergiant, the oblate wind of a Be star, and the winds of BA supergiants. Furthermore, we calculate synthetic spectra with FASTWIND, where we have used our new hydrodynamical solutions as input to the code.
Euclidean supergravity and multi-centered solutions
NASA Astrophysics Data System (ADS)
Sabra, W. A.
2017-04-01
In ungauged supergravity theories, the no-force condition for BPS states implies the existence of stable static multi-centered solutions. The first solutions to Einstein-Maxwell theory with a positive cosmological constant describing an arbitrary number of charged black holes were found by Kastor and Traschen. Generalisations to five and higher dimensional theories were obtained by London. Multi-centered solutions in gauged supergravity, even with time-dependence allowed, have yet to be constructed. In this letter we construct supersymmetry-preserving multi-centered solutions for the case of D = 5, N = 2 Euclidean gauged supergravity coupled to an arbitrary number of vector multiplets. Higher dimensional Einstein-Maxwell multi-centered solutions are also presented.
Interior solution for the Kerr metric
NASA Astrophysics Data System (ADS)
Hernandez-Pastora, J. L.; Herrera, L.
2017-01-01
A recently presented general procedure to find static and axially symmetric, interior solutions to the Einstein equations is extended to the stationary case, and applied to find an interior solution for the Kerr metric. The solution, which is generated by an anisotropic fluid, verifies the energy conditions for a wide range of values of the parameters, and matches smoothly to the Kerr solution, thereby representing a globally regular model describing a nonspherical and rotating source of gravitational field. In the spherically symmetric limit, our model converges to the well-known incompressible perfect fluid solution. The key stone of our approach is based on an ansatz allowing to define the interior metric in terms of the exterior metric functions evaluated at the boundary source. The physical variables of the energy-momentum tensor are calculated explicitly, as well as the geometry of the source in terms of the relativistic multipole moments.
Exact solution to fractional logistic equation
NASA Astrophysics Data System (ADS)
West, Bruce J.
2015-07-01
The logistic equation is one of the most familiar nonlinear differential equations in the biological and social sciences. Herein we provide an exact solution to an extension of this equation to incorporate memory through the use of fractional derivatives in time. The solution to the fractional logistic equation (FLE) is obtained using the Carleman embedding technique that allows the nonlinear equation to be replaced by an infinite-order set of linear equations, which we then solve exactly. The formal series expansion for the initial value solution of the FLE is shown to be expressed in terms of a series of weighted Mittag-Leffler functions that reduces to the well known analytic solution in the limit where the fractional index for the derivative approaches unity. The numerical integration to the FLE provides an excellent fit to the analytic solution. We propose this approach as a general technique for solving a class of nonlinear fractional differential equations.
Electronic solutions for combating counterfeit drugs
Hemalatha, R.; Rao, A. Srinivasa
2015-01-01
Introduction: The problem of counterfeiting of drugs is assuming alarming proportions and is getting difficult to combat due to its trans-national character. It is undermining the faith of people on health care system. Therefore, there is a need to adopt zero tolerance approach to combat the problem. The Way Forward: There are many solutions available which are being adopted in piece meal manner by individual manufacturers. However, for wholesalers and resellers it is getting difficult to maintain multiple solutions. Therefore, there is a need to adopt a unified solution preferably with the help of the government. Conclusions: This paper discusses the available solutions, their shortcomings and proposes a comprehensive solution where at each level in the supply chain the authenticity is verified preferable linking it with Unique identification. PMID:26229359
Stable FLRW solutions in generalized massive gravity
NASA Astrophysics Data System (ADS)
de Rham, Claudia; Fasiello, Matteo; Tolley, Andrew J.
2014-12-01
We present exact Friedmann Lemaítre Robertson Walkers (FLRW) solutions in generalized massive gravity where the mass parameters are naturally promoted to Lorentz-invariant functions of the Stückelberg fields. This new dependence relaxes the constraint that would otherwise prevent massive gravity from possessing exact FLRW solutions. It does so without the need to introduce additional degrees of freedom. We find self-accelerating cosmological solutions and show that, with a mild restriction on the region of phase space, these cosmological solutions exhibit full stability, i.e. absence of ghosts and gradient instabilities for all the tensor, vector and scalar modes, for all cosmic time. We perform the full decoupling limit analysis, including vector degrees of freedom, which can be used to confirm the existence of an active Vainshtein mechanism about these solutions.
Almost periodic solutions to difference equations
NASA Technical Reports Server (NTRS)
Bayliss, A.
1975-01-01
The theory of Massera and Schaeffer relating the existence of unique almost periodic solutions of an inhomogeneous linear equation to an exponential dichotomy for the homogeneous equation was completely extended to discretizations by a strongly stable difference scheme. In addition it is shown that the almost periodic sequence solution will converge to the differential equation solution. The preceding theory was applied to a class of exponentially stable partial differential equations to which one can apply the Hille-Yoshida theorem. It is possible to prove the existence of unique almost periodic solutions of the inhomogeneous equation (which can be approximated by almost periodic sequences) which are the solutions to appropriate discretizations. Two methods of discretizations are discussed: the strongly stable scheme and the Lax-Wendroff scheme.
Aquifer properties determined from two analytical solutions
Chen, X.; Ayers, J.F.
1998-09-01
Many ground water flow and contaminant transport studies involve unconfined aquifers. Determination of reliable hydraulic properties of unconfined aquifers is therefore important. In the analysis of pumping test data, the quality of the determined aquifer parameters can be greatly improved by using a proper model of the aquifer system. Moench (1995) provided an analytical solution for flow to a well partially penetrating an unconfined aquifer. His solution, in contrast to the Neuman solution (1974), accounts for the noninstantaneous decline of the water table (delayed yield). Consequently, the calculated drawdown in these two solutions is different under certain circumstances, and this difference may therefore affect the computation of aquifer properties from pumping test data. This paper uses an inverse computational method to calculate four aquifer parameters as well as a delayed yield parameter, {alpha}{sub 1}, from pumping test data using both the Neuman (1974) and Moench (1995) solutions. Time-drawdown data sets from a pumping test in an unconfined alluvial aquifer near Grand Island, Nebraska, were analyzed. In single-well analyses, horizontal hydraulic conductivity values derived from the Moench solution are lower, but vertical hydraulic conductivity values are higher than those calculated from the Neuman solution. However, the hydraulic conductivity values in composite-well analyses from both solutions become very close. Furthermore, the Neuman solution produces similar hydraulic conductivity values in the single-well and composite-well analyses, but the Moench solution does not. While variable {alpha}{sub 1} seems to play a role in affecting the computation of aquifer parameters in the single-well analysis, a much smaller effect was observed in the composite-well analysis.
ERIC Educational Resources Information Center
Metcalf, Linda
The intended audience for this handbook is teachers, administrators and school counselors who would like to approach school populations with a more positive, solution-focused approach. The ideas developed are based on the principles of solution-focused brief therapy (SFBT) and other competency-based models that address solutions rather than…
Non-weak/strong solutions in gasdynamics
NASA Astrophysics Data System (ADS)
van Dyne, David George
1999-10-01
Convergence of weak solutions of three conservation law gasdynamics equations to strong solutions cannot be proven. We compute non-weak/strong solutions directly utilizing gasdynamics equations without constructing weak forms. Dimensionless forms of Navier-Stokes equations are derived in matrix form directly from conservation laws for one-dimensional transient compressible flow using primitive variables ρ, u, p, and ρ, u, T. Analytical solutions of these parabolic equations must possess C2 continuity in space and C 1 continuity in time. For high-speed compressible flows analytical solutions of the GDE can be assumed to be of class C 11 in space and time since C1 continuity in space is justifiable. We construct p-version space-time least squares finite element formulations (STLSFEF) of the GDE in original parabolic form (i.e. no auxiliary variables or weak forms) in Eulerian and Lagrangian frames of reference using C11 type p-version hierarchical interpolations. Time-marching procedure is used to compute time evolution solutions for subsequent space-time strips. Numerical solution of Navier-Stokes equations for high- speed gasdynamics for isentropic and non-isentropic shocks without assumptions or approximations is demonstrated. Time accurate numerical studies show resolution of the shock structure (i.e. shock speed, shock width and shock relations) in excellent agreement with the analytical solutions. The role and influence of artificial viscosity and thermal conductivity on shock structure is demonstrated. Riemann shock tubes with pressure ratios of 20:1; 100:1 and 40:1:10 are used as model problems for formulations in Eulerian frame. Compression of air in a cylinder by a moving piston at velocities of Mach 1/