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)
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
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
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.
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.
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.
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.
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.
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.
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.
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. PMID:15714994
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.
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.
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].
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.
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.
Fibre optique à la maison en Pays de Gex et de Bellegarde
None
2011-10-06
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
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.
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
Spectroscopie Raman et Rayleigh stimulée des mélasses optiques unidimensionnelles (partie II)
NASA Astrophysics Data System (ADS)
Courtois, Jean-Yves
Dans la première partie de cet article, nous nous sommes attachés à décrire dans le détail les caractéristiques générales des processus de diffusion Raman et Rayleigh stimulée se produisant dans les milieux atomiques et moléculaires traditionnels, de manière à bien faire ressortir les spécificités des propriétés optiques non linéaires des mélasses optiques, dont l'étude fait l'objet de cette seconde partie. L'origine de ces spécificités réside dans une particularité des atomes refroidis par laser, à savoir l'intime corrélation entre degrés de liberté internes et externes dans leur réponse non linéaire. Cette caractéristique est en fait inhérente au processus de ralentissement : d'une part la force exercée par les faisceaux lasers sur les atomes (pression de radiation et redistribution de photons) dépend fortement de l'état atomique interne, et d'autre part cet état est modifié de façon très sélective en position ou en vitesse par les ondes lasers de refroidissement (déplacements lumineux et pompage optique). Elle sous-tend toute la richesse et l'originalité du comportement non linéaire des mélasses optiques, mais aussi toute la complexité de leur modélisation théorique, qui requiert une description globale de l'évolution des degrés de liberté internes et externes des atomes sous l'action des champs lasers. Afin de mettre en évidence le lien entre ces corrélations et les propriétés non linéaires des atomes froids, nous concentrerons notre étude d'une part sur les mélasses linbot lin qui constituent un cas de couplage entre état interne et position des atomes localisés au fond des puits du potentiel associé aux déplacements lumineux (paragr. 4), et d'autre part sur les mélasses σ^+-σ- qui correspondent quant à elles à un couplage entre état interne et vitesse atomiques (paragr. 5).
Transport dans l'hélium 3 polarisé par pompage optique
NASA Astrophysics Data System (ADS)
Lhuillier, C.; Leduc, M.
Optical pumping is, in the case of helium 3, a useful method for polarizing the nuclear spins of the gas. Substantial orientation rates can be now achieved using tunable infrared lasers. Large changes in the macroscopic behaviour of the helium 3 fluid occur as a consequence of the polarization of the nuclei, provided the temperature is low enough, in spite of the small nuclear magnetic moment. These effects result both from interactions and statistics and are subtle consequences of the indistinguishability of particles and of the symmetrization principle in quantum mechanics. One explains in this article the expected changes for the viscosity and the heat conduction in the gas below a few kelvins. Furthermore, one shows that the transport of spin magnetization in polarized helium 3 (3He↑) has a propagative character at low temperature, giving rise to collective oscillatory modes : the transverse spin waves. One describes a recent experiment which proved the existence of these waves and allowed measuring their quality factor. Observations and theoretical predictions are in good agreement. Le pompage optique constitue, dans le cas de l'hélium 3, une méthode commode pour polariser les spins nucléaires du gaz. Des taux d'orientation notables peuvent être maintenant réalisés grâce aux lasers accordables dans l'infrarouge. Des changements importants de comportement macroscopique du fluide d'hélium 3 se produisent sous l'effet de la polarisation des noyaux, à condition que la température soit suffisamment basse, et ceci malgré la petitesse du moment magnétique nucléaire ; il s'agit là d'effets conjugués d'interaction et de statistique, manifestations subtiles de l'indiscernabilité des particules et du principe de symétrisation en mécanique quantique. On explique dans cet article les modifications attendues pour la viscosité et la conduction de la chaleur dans le gaz en dessous de quelques kelvins. De plus, on montre que le transport de spin dans l
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.
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.
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
NASA Astrophysics Data System (ADS)
Gervais, J.
1993-07-01
The minority carrier diffusion length L characterizes the electrical quality of multicrystalline silicon wafers used for photovoltaics. Its determination before and after different treatments (impurity diffusion, passivation, metallisation) is needfull and requires the accurate knowledge of the optical absorption coefficient α in the near infrared. We have determinated the spectral variation of α in the range between 0.86 and 1.06 μm and we propose an analytic expression which is very close to those proposed for solar grade single crystals. In addition we have verified that the values of α are not affected by long phosphorus diffusion needed to getter metallic impurities. La longueur de diffusion des porteurs minoritaires L caractérise la qualité du silicium multicristallin utilisé pour la conversion photovoltaïque. Sa détermination avant et après les divers traitements (diffusion d'impuretés, passivation des défauts, métallisation) est indispensable et nécessite la connaissance précise du coefficient d'absorption optique α dans le proche infrarouge. Nous avons déterminé expérimentalement la variation spectrale de α entre 0,86 et 1,06 μm et nous proposons un développement qui est très proche de ceux trouvés dans des monocristaux de silicium de qualité solaire. La variation de α n'est pas influencée par des diffusions de phosphore prolongées nécessaires à l'extraction et au piégeage d'impuretés métalliques.
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)
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
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.
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.
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
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.
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)
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)
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.
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
NASA Astrophysics Data System (ADS)
Lombard, J.-P.; Seinturier, E.; Raynaud, J.-L.
2002-12-01
La conception dynamique des roues aubagées consiste à éviter que les modes de la structure ne soient excités par des harmoniques du régime moteur (coïncidences prédites à partir de l'analyse d'un diagramme de Campbell). En pratique, il est impossible d'éviter toute coïncidence sur l'ensemble de la plage de fonctionnement. Un essai moteur est effectué à la fin du cycle de conception pour déterminer les niveaux vibratoires. A partir de cet essai et du modèle EF validé, le concepteur vérifie ses marges fréquentielles et sait déterminer si la roue aubagée est soumise ou non au risque de fatigue vibratoire (HCF). Cette analyse nécessite plusieurs calculs EF dont les modèles ont été recalés par rapport à des essais partiels de distribution de contrainte (mesurée à l'aide de jauges de déformation). Une des limitations de ce type de mesure réside dans le caractère intrusif de l'instrumentation qui perturbe le comportement dynamique des aubes, notamment pour les modes de rang élevé. L'application de mesures optiques non intrusives sur des aubes est présentée ici, et met en évidence la précision qu'il est possible d'obtenir sur la mesure des déformées modales. De plus, ce papier illustre l'intérêt de borner la précision des mesures obtenues par exemple dans la caractérisation des dispersions en fréquence aube à aube, dispersions qui se traduisent par une amplification de la réponse aéroélastique de la structure.
NASA Astrophysics Data System (ADS)
Marco, O.
1998-05-01
L'observation a haute resolution angulaire a connu un nouvel elan avec la mise au point de systemes d'optique adaptative fonctionnant dans l'infrarouge. La camera COMIC, seconde camera dediee a ADONIS, le systeme d'optique adaptative equipant le telescope de 3.60 metres de l'ESO, permet l'observation dans le domaine spectral 3-5 microns a la limite de resolution angulaire du telescope. La caracterisation de la camera au laboratoire a Meudon et Grenoble, puis la determination de ses performances sur le site au Chili sont l'objet de la premiere partie de cette These. Une methode originale d'evaluation des magnitudes limites atteintes est proposee, qui prend en compte a chaque stade les differents facteurs de perte de detectivite entre les mesures au laboratoire et celles en conditions reelles. Cette approche pourra etre envisagee chaque fois que l'on a connaissance a priori des conditions d'observation (quantifiees en particulier par le rapport de Strehl, ou encore par une estimation du seeing). L'etude de la region centrale (~1 arcsec) des Noyaux Actifs de Galaxies necessite l'acces a la haute resolution angulaire. En particulier, la poussiere chaude emet dans le domaine 1-5 microns. L'observation des NAG avec un systeme d'optique adaptative est donc tout indiquee. La theorie d'unification des NAG prevoit la presence d'un tore moleculaire et poussiereux, responsable d'effets masquant selon l'angle de visee sous lequel on les observe, induisant des proprietes observationnelles distinctes pour des objets supposes identiques. Les observations real isees avec ADONIS & COMIC de NGC 7469 et NGC 1068 ont montre la presence d'une grande quantite de poussieres chaudes localisees a l'emplacement du tore presume, mais aussi melangees avec le gaz de la region d'emission de raies etroites. La haute resolution angulaire atteinte a permis de preciser la temperature des poussieres chaudes, leur masse, et leur distribution spatiale autour de la source centrale du NAG. Ces resultats
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.
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)
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
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.
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…
Hill, Colin
2010-01-01
Recently we reported a role for compatible solute uptake in mediating bile tolerance and increased gastrointestinal persistence in the foodborne pathogen Listeria monocytogenes.1 Herein, we review the evolution in our understanding of how these low molecular weight molecules contribute to growth and survival of the pathogen both inside and outside the body, and how this stress survival mechanism may ultimately be used to target and kill the pathogen. PMID:21326913
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.
NASA Astrophysics Data System (ADS)
Chun, Tiejun; Zhu, Deqing; Pan, Jian; He, Zhen
2014-06-01
Recovery of alumina from magnetic separation tailings of red mud has been investigated by Na2CO3 solution leaching. X-ray diffraction (XRD) results show that most of the alumina is present as 12CaO·7Al2O3 and CaO·Al2O3 in the magnetic separation tailings. The shrinking core model was employed to describe the leaching kinetics. The results show that the calculated activation energy of 8.31 kJ/mol is characteristic for an internal diffusion-controlled process. The kinetic equation can be used to describe the leaching process. The effects of Na2CO3 concentration, liquid-to-solid ratio, and particle size on recovery of Al2O3 were examined.
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
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
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.
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.…
Contact Lens Solution Toxicity
... rash and rashes clinical tools newsletter | contact Share | Contact Lens Solution Toxicity Information for adults A A A This image shows a reaction to contact lens solution. The prominent blood vessels and redness ...
Spectroscopic studies of solutes in aqueous solution.
Chai, Bing-hua; Zheng, Jian-ming; Zhao, Qing; Pollack, Gerald H
2008-03-20
Absorption and fluorescence characteristics of aqueous solutions of salts, sugars, and amino acids were studied using UV-vis spectroscopy and spectrofluorometry. Motivation stemmed from unanticipated absorption spectral and fluorescence features of the "exclusion zone" seen adjacent to various hydrophilic surfaces. Those features implied a structure distinct from that of bulk water (Adv. Colloid Interface Sci. 2006, 127, 19). Absorption peaks at approximately 270 nm similar to those observed in the exclusion zone were seen in solutions of the following substances: salts, Nafion 117 solution/film, l-lysine, d-alanine, d-glucose and sucrose. To determine the fate of the absorbed energy, we studied the fluorescence properties of these solutions. The salts showed fluorescence emission around 480-490 nm under different excitation wavelengths. The fluorescence intensity of LiCl was higher than NaCl, which was in turn higher than KCl-the same ordering as the absorption intensities. Fluorescence of Nafion 117 solution/film, l-lysine, d-alanine, d-glucose and sucrose were observed as well, with multiple excitation wavelengths. Hence, at least some of the absorbed energy is released as fluorescence. The results show features closely similar to those observed in the exclusion zone, implying that the aqueous region around the solutes resembles the aqueous zone adjacent to hydrophilic surfaces. Both may be more extensively ordered than previously thought. PMID:18298105
The electromagnetic spike solutions
NASA Astrophysics Data System (ADS)
Nungesser, Ernesto; Lim, Woei Chet
2013-12-01
The aim of this paper is to use the existing relation between polarized electromagnetic Gowdy spacetimes and vacuum Gowdy spacetimes to find explicit solutions for electromagnetic spikes by a procedure which has been developed by one of the authors for gravitational spikes. We present new inhomogeneous solutions which we call the EME and MEM electromagnetic spike solutions.
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.
Moen, Marit D
2009-01-01
Topical diclofenac solution (Pennsaid) is a liquid formulation containing the NSAID diclofenac sodium (1.5% w/w). The solution base contains 45% w/w dimethyl sulfoxide (DMSO) to enhance the absorption of diclofenac through the skin. Topical diclofenac solution is applied directly to the knee for treatment of symptoms associated with osteoarthritis of the knee. In well designed 4- to 12-week trials in patients with primary osteoarthritis of the knee, topical diclofenac solution (40 drops four times daily) was significantly more effective than placebo or vehicle control (carrier solution without diclofenac) for improving Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index pain and physical function, and improving patient global assessment (PGA) and/or patient overall health assessment scores from baseline to the final assessments. Topical diclofenac solution (50 drops three times daily) was as effective as oral diclofenac 150 mg/day for improving WOMAC pain and physical function and PGA scores in a 12-week double-blind study in patients with osteoarthritis of the knee. Topical diclofenac solution was generally well tolerated. The most common treatment-emergent adverse event experienced by topical diclofenac solution recipients was dry skin at the application site. Gastrointestinal adverse events and abnormal laboratory parameters were less common with topical diclofenac solution than with oral diclofenac. PMID:19943711
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.
NASA Astrophysics Data System (ADS)
Formiga, J. B.; Almeida, T. S.
2014-10-01
The most general solution of the Einstein field equations coupled with a massless scalar field is known as Wyman's solution. This solution is also present in the Brans-Dicke theory and, due to its importance, it has been studied in detail by many authors. However, this solutions has not been studied from the perspective of a possible wormhole. In this paper, we perform a detailed analysis of this issue. It turns out that there is a wormhole. Although we prove that the so-called throat cannot be traversed by human beings, it can be traversed by particles and bodies that can last long enough.
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, 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.
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.
Conduction heat transfer solutions
VanSant, J.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.
Elprince, A.M.
1986-01-01
Designed for advanced undergraduate and graduate students and researchers, this book serves as an introduction to the field of soil chemistry and associated fields such as aquatic chemistry, geochemistry, environmental chemistry, oceanography, and public health. The volume includes discussions on the structure of adsorbed water, adsorption of inorganics, solubility, redox, solute transport, chemical modeling, and sampling and monitoring the soil solution. Important papers on these topics together with editor's comments place each of the carefully chosen papers in the proper context. Because the chemistry of soil solutions requires the knowledge of many aspects of science, introductory information is provided for each topic to cover its history of development, present knowledge, and future prospects.
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.
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)
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.
Réseaux optiques multi-longueur d'onde
NASA Astrophysics Data System (ADS)
Berthelon, Luc; Courtois, O.; Garnot, M.; Laalaoua, R.
2003-02-01
This paper describes the main trends and design issues in the design of current generation of WDM optical networks, and the enabling factors and motivations that will push to build the next generation transport networks. The latter will benefit from new optical technologies (ultra-long haul, switching,…) to reduce the network cost, and from new control technologies (Generalised Multi-Protocol Label Switching) that will make them dynamically flexible to better serve the changing traffic demands of emerging services. The paper covers all aspects of the network: network design and planning, system and architecture design, technologies, control and management. It also includes an overview of current state of the art and observations/statistics learnt from network studies. To cite this article: L. Berthelon et al., C. R. Physique 4 (2003).
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.
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.
Reece, Barry; Smith, Kathleen; Miller, Terri
2013-01-01
Background: Onychomycosis is a chronic condition that often requires long-term management to eradicate the causative fungus, allow a healthy nail to grow, and prevent relapse. As a successful outcome depends highly on patient adherence with treatment, a low risk of periungual skin irritation with topical medication is clinically relevant. Objectives: To study the potential for efinaconazole 10% solution and its corresponding vehicle to induce delayed contact skin sensitization and evaluate its skin irritation potential. Methods: Efinaconazole 10% solution and its vehicle were studied in 239 healthy volunteers for the potential to induce contact skin sensitization. This included a series of induction, challenge, and re-challenge phases. An additional 21-day cumulative irritation study was undertaken in 35 healthy volunteers to compare three concentrations of efinaconazole (1%, 5%, and 10%), vehicle, and positive/negative controls. Results: There was no evidence of induced contact sensitization under occlusive, semi-occlusive, and open (open rub-in) applications of efinaconazole 10% solution. Efinaconazole 1%, 5%, and 10% solutions have mean cumulative irritancy indices of 1.12, 1.26, and 1.18, respectively, where a range of >0 to ≤1 is classified as “mildly irritating.” Results were comparable to vehicle (1.04). Conclusion: Efinaconazole 10% solution did not cause contact sensitization and induced only minimal skin irritation in the studies completed. PMID:23556032
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.
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.
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.
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.
School Solutions for Cyberbullying
ERIC Educational Resources Information Center
Sutton, Susan
2009-01-01
This article offers solutions and steps to prevent cyberbullying. Schools can improve their ability to handle cyberbullying by educating staff members, students, and parents and by implementing rules and procedures for how to handle possible incidents. Among the steps is to include a section about cyberbullying and expectations in the student…
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…
Correct Problems, Desperate Solutions.
ERIC Educational Resources Information Center
Donohue, William A.
1996-01-01
Argues that the social problems confronting America have been bombarded with ill-conceived and unsuccessful social policy largely driven by fear. Explains that parental licensing is a draconian and unworkable solution. Vouchers for indigent youth to attend Catholic schools, developing after-school and summer programs, and reforming welfare are…
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
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…
Knowledge Retrieval Solutions.
ERIC Educational Resources Information Center
Khan, Kamran
1998-01-01
Excalibur RetrievalWare offers true knowledge retrieval solutions. Its fundamental technologies, Adaptive Pattern Recognition Processing and Semantic Networks, have capabilities for knowledge discovery and knowledge management of full-text, structured and visual information. The software delivers a combination of accuracy, extensibility,…
The sustainability solutions agenda.
Sarewitz, Daniel; Clapp, Richard; Crumbley, Cathy; Kriebel, David; Tickner, Joel
2012-01-01
Progress toward a more sustainable society is usually described in a "knowledge-first" framework, where science characterizes a problem in terms of its causes and mechanisms as a basis for subsequent action. Here we present a different approach-A Sustainability Solutions Agenda (SSA)-which seeks from the outset to identify the possible pathways to solutions. SSA focuses on uncovering paths to sustainability by improving current technological practice, and applying existing knowledge to identify and evaluate technological alternatives. SSA allows people and organizations to transition toward greater sustainability without sacrificing essential technological functions, and therefore does not threaten the interests that depend on those functions. Whereas knowledge-first approaches view scientific information as sufficient to convince people to take the right actions, even if those actions are perceived as against their immediate interests, SSA allows values to evolve toward greater attention to sustainability as a result of the positive experience of solving a problem. PMID:22776577
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.
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.
Stabilization of polyaniline solutions
Wrobleski, D.A.; Benicewicz, B.C.
1993-12-01
Adding hindered amine light stabilizers (HALS) to N-methyl- pyrrolidinone (NMP) solutions of polyaniline delays gelation. It is hypothesized that HALS act in some manner other than as traditional antioxidants in preventing gelation; the secondary amine functional group appears to play a critical role, perhaps by disrupting the physical crystallization network that may contribute to gelation. Pyrrolidine, a secondary amine, or ammonia is an effective cosolvent with NMP in dissolving PAn-EB (emeraldine base). 6 refs, 4 figs.
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.
Radiographic solution contamination.
Hardman, P K; Tilmon, M F; Taylor, T S
1987-06-01
Contamination of processor solutions adversely affects the image quality of radiographic films. The purpose of this study was to determine the amount of developer or fixer contaminant that was necessary to produce a significant densitometric change in the base plus fog, speed, or contrast optical density readings for panoramic film. Significant differences in base plus fog (after 16 mL of fixer contaminant was added to developer), speed index (after 4 mL), and contrast index (after 8 mL) were observed in comparison with control values. PMID:3473399
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.
Generating Problems from Problems and Solutions from Solutions
ERIC Educational Resources Information Center
Arcavi, Abraham; Resnick, Zippora
2008-01-01
This article describes a geometrical solution to a problem that is usually solved geometrically as an example of how alternative solutions may enrich the teaching and learning of mathematics. (Contains 11 figures.)
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.
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.
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.
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).
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.
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
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.
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)
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.
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
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).
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.
Wetting in electrolyte solutions.
Ibagon, Ingrid; Bier, Markus; Dietrich, S
2013-06-01
Wetting of a charged substrate by an electrolyte solution is investigated by means of classical density functional theory applied to a lattice model. Within the present model the pure, i.e., salt-free solvent, for which all interactions are of the nearest-neighbor type only, exhibits a second-order wetting transition for all strengths of the substrate-particle and the particle-particle interactions for which the wetting transition temperature is nonzero. The influences of the substrate charge density and of the ionic strength on the wetting transition temperature and on the order of the wetting transition are studied. If the substrate is neutral, the addition of salt to the solvent changes neither the order nor the transition temperature of the wetting transition of the system. If the surface charge is nonzero, upon adding salt this continuous wetting transition changes to first-order within the wide range of substrate surface charge densities and ionic strengths studied here. As the substrate surface charge density is increased, at fixed ionic strength, the wetting transition temperature decreases and the prewetting line associated with the first-order wetting transition becomes longer. This decrease of the wetting transition temperature upon increasing the surface charge density becomes more pronounced by decreasing the ionic strength. PMID:23758391
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.
Experimental Structural Studies of Solutes in Aqueous Solution
Persson, Ingmar
2007-11-29
The principles of experimental methods to study the structure and the hydrogen bonding of hydrated solutes in aqueous solution are presented, and whether theoretical simulations can produce comparable information as the experimental ones is discussed. Two structure methods, extended X-ray absorption fine structure (EXAFS) and large angle X-ray scattering (LAXS), and one method to study the hydrogen bonding in hydrated species in aqueous solution, double difference infrared spectroscopy of HDO, are presented.
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.
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.
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.
Cylindrical solutions in mimetic gravity
NASA Astrophysics Data System (ADS)
Momeni, Davood; Myrzakulov, Kairat; Myrzakulov, Ratbay; Raza, Muhammad
2016-06-01
This paper is devoted to investigate cylindrical solutions in mimetic gravity. The explicit forms of the metric of this theory, namely mimetic-Kasner (say) have been obtained. In this study we have noticed that the Kasner's family of exact solutions needs to be reconsidered under this type of modified gravity. A no-go theorem is proposed for the exact solutions in the presence of a cosmological constant.
Cylindrical solutions in braneworld gravity
Khoeini-Moghaddam, S.; Nouri-Zonoz, M.
2005-09-15
In this article we investigate exact cylindrically symmetric solutions to the modified Einstein field equations in the braneworld gravity scenarios. It is shown that for the special choice of the equation of state 2U+P=0 for the dark energy and dark pressure, the solutions found could be considered formally as solutions of the Einstein-Maxwell equations in 4-D general relativity.
Colligative properties of simple solutions.
Andrews, F C
1976-11-01
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. PMID:17818408
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.
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.
Amine treatment of polysaccharide solution
Shay, L. K.; Reiter, S. E.
1984-11-27
A thermostable, viscous xanthan polysaccharide solution prepared by the process of heating a xanthan polysaccharide solution in the presence of at least one C/sub 1/ to C/sub 10/ alkyl or C/sub 3/ to C/sub 10/ cycloalkyl substituted primary or secondary mono- or diamine having an upper limit of a total of 15 carbon atoms under conditions sufficient to form a thermostable, viscous xanthan polysaccharide solution. The thermostable, viscous xanthan polysaccharide solution may be used as a mobility buffer in a process for the enhanced recovery of oil.
Water activity in supersaturated aqueous solutions of organic solutes
NASA Astrophysics Data System (ADS)
Na, Han-Soo; Arnold, Stephen; Myerson, Allan S.
1995-04-01
Measurements of water activity in supersaturated aqueous organic solutions of glycine, alanine, succinic acid and itaconic acid were made far into the metastable zone by levitating micron-sized droplets electrodynamically in a spherical void electrodynamic levitator trap (SVELT) with a water vapor reservoir. The concentration dependent behavior of the activity was examined in relationship to the molecular interactions for solutions.
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.
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…
Vainshtein solutions without superluminal modes
NASA Astrophysics Data System (ADS)
Gabadadze, Gregory; Kimura, Rampei; Pirtskhalava, David
2015-06-01
The Vainshtein mechanism suppresses the fifth force at astrophysical distances, while enabling it to compete with gravity at cosmological scales. Typically, Vainshtein solutions exhibit superluminal perturbations. However, a restricted class of solutions with special boundary conditions was shown to be devoid of the faster-than-light modes. Here we extend this class by finding solutions in a theory of quasidilaton, amended by derivative terms consistent with its symmetries. Solutions with Minkowski asymptotics are not stable, while the ones that exhibit the Vainshtein mechanism by transitioning to cosmological backgrounds are free of ghosts, tachyons, gradient instability, and superluminality, for all propagating modes present in the theory. These solutions require a special choice of the strength and signs of nonlinear terms, as well as a choice of asymptotic cosmological boundary conditions.
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.
Multigrid solution of internal flows using unstructured solution adaptive meshes
NASA Astrophysics Data System (ADS)
Smith, Wayne A.; Blake, Kenneth R.
1992-11-01
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.
Effect of chlorides on solution corrosivity of methyldiethanolamine (MDEA) solutions
Rooney, P.C.; Bacon, T.R.; DuPart, M.S.; Willbanks, K.D.
1997-08-01
Solution corrosivity of MDEA/water solutions containing added HCl or NaCl have been measured by weight loss coupons at 250 F and by linear polarization resistance (LPR) at 208 F using carbon steel, 304SS, 316SS and 410SS. General corrosion as well as pitting or crevice corrosion tendencies were recorded for each species. Based on these results, recommendations are made for chlorides in MDEA that minimizes corrosion in gas treating operations.
Contamination of dental radiographic solutions.
Tamburus, J R; Pardini, L C; Watanabe, P C
1995-01-01
Thirteen groups of periapical radiographic films were evaluated to determine and compare within and between groups the effects of contamination of the fixer solution with developing solution during radiographic processing. An aluminum penetrometer was used as the radiographic object to produce different optical densities. The images were compared using radiographic density and contrast as parameters. There were significant differences between the control groups and the groups processed with a contaminated fixer solution. No statistically significant differences were observed in the intragroup comparisons. PMID:8688649
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.
Analytic Solutions and Resonant Solutions of Hyperbolic Partial Differential Equations
NASA Astrophysics Data System (ADS)
Wagenmaker, Timothy Roger
This dissertation contains two main subject areas. The first deals with solutions to the wave equation Du/Dt + a Du/Dx = 0, where D/Dt and D/Dx represent partial derivatives and a(t,x) is real valued. The question I studied, which arises in control theory, is whether solutions which are real analytic with respect to the time variable are dense in the space of all solutions. If a is real analytic in t and x, the Cauchy-Kovalevsky Theorem implies that the solutions real analytic in t and x are dense, since it suffices to approximate the initial data by polynomials. The same positive result is valid when a is continuously differentiable and independent of t. This is proved by regularization in time. The hypothesis that a is independent of t cannot be replaced by the weaker assumption that a is real analytic in t, even when it is infinitely smooth. I construct a(t,x) for which the solutions which are analytic in time are automatically periodic in time. In particular these solutions are not dense in the space of all solutions. The second area concerns the resonant interaction of oscillatory waves propagating in a compressible inviscid fluid. An asymptotic description given by Andrew Majda, Rodolfo Rosales, and Maria Schonbek (MRS) involves the genuinely nonlinear quasilinear hyperbolic system Du/Dt + D(uu/2)/Dt + v = 0, Dv/Dt - D(vv/2)/Dt - u = 0. They performed many numerical simulations which indicated that small amplitude solutions of this system tend to evade shock formation, and conjectured that "smooth initial data with a sufficiently small amplitude never develop shocks throughout a long time interval of integration.". I proved that for smooth periodic U(x), V(x) and initial data u(0,x) = epsilonU(x), v(0,x) = epsilonV(x), the solution is smooth for time at least constant times | ln epsilon| /epsilon. This is longer than the lifetime order 1/ epsilon of the solution to the decoupled Burgers equations. The decoupled equation describes nonresonant interaction of
Peritoneal dialysis solution and nutrition.
Verger, Christian
2012-01-01
20-70% of peritoneal dialysis patients have some signs of malnutrition. Anorexia, protein and amino acid losses in dialysate, advanced age of elderly patients, inflammation and cardiac failure are among the main causes. Modern dialysis solutions aim to reduce these causes, but none of them is without side effects: glucose is relatively safe and brings additional energy but induces anorexia and lipid abnormalities, amino acids compensate dialysate losses but may increase uremia and acidosis, icodextrin helps control hyperhydration and chronic heart failure and minimizes glucose side effects, but may sometimes cause inflammation, and poly chamber bags allow the replacement of lactate by bicarbonate and are more biocompatible, decrease GDP, induce less inflammation and have a better effect on nutritional status. However, it appears that the management of nutrition with the different solutions available nowadays necessitates various combinations of solutions adapted to different patient profiles and there is not actually a single universal solution to minimize malnutrition in peritoneal dialysis patients. PMID:22652708
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.
Monitoring Crystal Growth From Solution
NASA Technical Reports Server (NTRS)
Lal, R. B.
1982-01-01
Experimental system for monitoring growth of triglycine sulfate (TGS) crystals from solution is being studied. System consists of outer cell containing distilled water heated and stirred to maintain constant temperature to within plus or minus 0.1 degrees C, inner (growth) cell containing supersaturated solution of TGS, and seed crystal mounted in plastic-covered stainless-steel sting equiped with controlled cooling mechanism and temperature sensors.
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.)
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
Faculty practice: dilemmas and solutions.
Joachim, G
1988-05-01
While nursing educators in university settings teach, carry out research and provide some form of community service, they often do not practise. The reasons for not practising are varied and the consequences vast. Although there are dilemmas which perpetuate the situation of nursing professors not participating in practice, there are solutions. This paper places the issue in an historical perspective, notes its consequences, discusses the dilemmas which are involved and offers solutions to this complex problem. PMID:3417937
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.
Organic Solutes in Hyperthermophilic Archaea
Martins, L. O.; Huber, R.; Huber, H.; Stetter, K. O.; Da Costa, M. S.; Santos, H.
1997-01-01
We examined the accumulation of organic solutes under optimum growth conditions in 12 species of thermophilic and hyperthermophilic Archaea belonging to the Crenarchaeota and Euryarchaeota. Pyrobaculum aerophilum, Thermoproteus tenax, Thermoplasma acidophilum, and members of the order Sulfolobales accumulated trehalose. Pyrococcus furiosus accumulated di-myo-inositol-1,1(prm1)(3,3(prm1))-phosphate and (beta)-mannosylglycerate, Methanothermus fervidus accumulated cyclic-2,3-bisphosphoglycerate and (beta)-mannosylglycerate, while the only solute detected in Pyrodictium occultum was di-myo-inositol-1,1(prm1)(3,3(prm1))-phosphate. Methanopyrus kandleri accumulated large concentrations of cyclic-2,3-bisphosphoglycerate. On the other hand, Archaeoglobus fulgidus accumulated three phosphorylated solutes; prominent among them was a compound identified as di-glycerol-phosphate. This solute increased in concentration as the salinity of the medium and the growth temperature were raised, suggesting that this compound serves as a general stress solute. Di-myo-inositol-1,1(prm1)(3,3(prm1))-phosphate accumulated at supraoptimal temperature only. The relationship between the accumulation of unusual solutes and high temperatures is also discussed. PMID:16535556
Rheology of clustering protein solutions.
Dharmaraj, Vishnu L; Godfrin, P Douglas; Liu, Yun; Hudson, Steven D
2016-07-01
High viscosity is a major challenge with protein therapeutics at extremely high concentrations. To overcome this obstacle, it is essential to understand the relationship between the concentration of a protein solution and its viscosity as a function of shear rate and temperature. Here, lysozyme is a model charged globular protein having both short-ranged attraction (SA) and long-ranged repulsion (LR) that promote the formation of dynamic clusters at high concentrations. We report viscosity measurements from a micro-capillary rheometer (using only several microliters of solution) over a wide range of lysozyme solution concentrations, shear rates, and temperatures. Solution structural relaxation dynamics are also probed by dynamic light scattering (DLS). As a result of lysozyme's SALR interactions, the viscosity increased dramatically across all shear rates with increasing concentration and decreasing temperature. While most of the solutions exhibited Newtonian behavior, shear thinning was exhibited at the highest concentration (480 g/l) and lowest temperatures at shear rates above approximately 10(4 )s(-1). The onset shear rate for thinning and a structural relaxation rate estimated from a slow-mode measured by DLS are compared. These measurements provide insights into the properties of protein solutions and their microscopic structural origins. PMID:27478524
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.
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. PMID:24838258
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. PMID:25158101
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. PMID:16610849
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
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.
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.
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.
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
Ions in hyaluronic acid solutions
NASA Astrophysics Data System (ADS)
Horkay, Ferenc; Basser, Peter J.; Londono, David J.; Hecht, Anne-Marie; Geissler, Erik
2009-11-01
Hyaluronic acid (HA) is an anionic biopolymer that is almost ubiquitous in biological tissues. An attempt is made to determine the dominant features that account for both its abundance and its multifunctional role, and which set it apart from other types of biopolymers. A combination of osmotic and scattering techniques is employed to quantify its dynamic and static properties in near-physiological solution conditions, where it is exposed both to mono- and divalent counterions. An equation of state is derived for the osmotic pressure Π in the semidilute concentration region, in terms of two variables, the polymer concentration c and the ionic strength J of the added salt, according to which Π =1.4×103c9/4/J3/4 kPa, where c and J are expressed in mole. Over the physiological ion concentration range, the effect of the sodium chloride and calcium chloride on the osmotic properties of HA solutions is fully accounted for by their contributions to the ionic strength. The absence of precipitation, even at high CaCl2 concentrations, distinguishes this molecule from other biopolymers such as DNA. Dynamic light scattering measurements reveal that the collective diffusion coefficient in HA solutions exceeds that in aqueous solutions of typical neutral polymers by a factor of approximately 5. This property ensures rapid adjustment to, and recovery from, stress applied to HA-containing tissue. Small angle x-ray scattering measurements confirm the absence of appreciable structural reorganization over the observed length scale range 10-1000 Å, as a result of calcium-sodium ion exchange. The scattered intensity in the transfer momentum range q >0.03 Å-1 varies as 1/q, indicating that the HA chain segments in semidilute solutions are linear over an extended concentration range. The osmotic compression modulus c ∂Π/∂c, a high value of which is a prerequisite in structural biopolymers, is several times greater than in typical neutral polymer solutions.
Catchment controls on solute export
NASA Astrophysics Data System (ADS)
Musolff, Andreas; Schmidt, Christian; Selle, Benny; Fleckenstein, Jan H.
2015-12-01
Dynamics of solute export from catchments can be classified in terms of chemostatic and chemodynamic export regimes by an analysis of concentration-discharge relationships. Previous studies hypothesized that distinct export regimes emerge from the presence of solute mass stores within the catchment and their connectivity to the stream. However, so far a direct link of solute export to identifiable catchment characteristics is missing. Here we investigate long-term time series of stream water quality and quantity of nine neighboring catchments in Central Germany ranging from relatively pristine mountain catchments to agriculturally dominated lowland catchments, spanning large gradients in land use, geology, and climatic conditions. Given the strong collinearity of catchment characteristics we used partial least square regression analysis to quantify the predictive power of these characteristics for median concentrations and the metrics of export regime. We can show that median concentrations and metrics of the export regimes of major ions and nutrients can indeed be inferred from catchment characteristics. Strongest predictors for median concentrations were the share of arable land, discharge per area, runoff coefficient and available water capacity in the root zone of the catchments. The available water capacity in the root zone, the share of arable land being artificially drained and the topographic gradient were found to be the most relevant predictors for the metrics of export regime. These catchment characteristics can represent the size of solute mass store such as the fraction of arable land being a measure for the store of nitrate. On the other hand, catchment characteristics can be a measure for the connectivity of these solute stores to the stream such as the fraction of tile drained land in the catchments. This study demonstrates the potential of data-driven, top down analyses using simple metrics to classify and better understand dominant controls of
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.
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.
Lump solutions of the BKP equation
NASA Astrophysics Data System (ADS)
Gilson, C. R.; Nimmo, J. J. C.
1990-07-01
Rational solutions of the BKP equation which decay to zero in all directions in the plane are obtained. These solutions are analogous to the lump solutions of the KPI equation. Properties of the single lump solution are described and the form of the N-lump solution is given. It is shown that single lump solutions are only non-singular for spectral parameters lying in certain regions of the complex plane.
Numerical Asymptotic Solutions Of Differential Equations
NASA Technical Reports Server (NTRS)
Thurston, Gaylen A.
1992-01-01
Numerical algorithms derived and compared with classical analytical methods. In method, expansions replaced with integrals evaluated numerically. Resulting numerical solutions retain linear independence, main advantage of asymptotic solutions.
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.
Solution-Assisted Optical Contacting
NASA Technical Reports Server (NTRS)
Shaddock, Daniel; Abramovici, Alexander
2004-01-01
A modified version of a conventional optical-contact procedure has been found to facilitate alignment of optical components. The optical-contact procedure (called simply optical contacting in the art) is a standard means of bonding two highly polished and cleaned glass optical components without using epoxies or other adhesives. In its unmodified form, the procedure does not involve the use of any foreign substances at all: components to be optically contacted are dry. The main disadvantage of conventional optical contacting is that it is difficult or impossible to adjust the alignment of the components once they have become bonded. In the modified version of the procedure, a drop of an alcohol-based optical cleaning solution (isopropyl alcohol or similar) is placed at the interface between two components immediately before putting the components together. The solution forms a weak bond that gradually strengthens during a time interval of the order of tens of seconds as the alcohol evaporates. While the solution is present, the components can be slid, without loss of contact, to perform fine adjustments of their relative positions. After about a minute, most of the alcohol has evaporated and the optical components are rigidly attached to each other. If necessary, more solution can be added to enable resumption or repetition of the adjustment until the components are aligned to the required precision.
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.
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.
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)…
Classroom Management: Problems and Solutions.
ERIC Educational Resources Information Center
Gordon, Debra G.
2001-01-01
Focuses on classroom management in the music classroom. Discusses why a management system is important and how to meet student needs. Addresses types of behavior problems and solutions for four levels of problems related to student behavior. Explores the importance of proactive management on the part of the music teacher. (CMK)
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…
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.
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.
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…
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.
Sucrose diffusion in aqueous solution.
Price, Hannah C; Mattsson, Johan; Murray, Benjamin J
2016-07-28
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
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.
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
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
Solute strengthening at high temperatures
NASA Astrophysics Data System (ADS)
Leyson, G. P. M.; Curtin, W. A.
2016-08-01
The high temperature behavior of solute strengthening has previously been treated approximately using various scaling arguments, resulting in logarithmic and power-law scalings for the stress-dependent energy barrier Δ E(τ ) versus stress τ. Here, a parameter-free solute strengthening model is extended to high temperatures/low stresses without any a priori assumptions on the functional form of Δ E(τ ) . The new model predicts that the well-established low-temperature, with energy barrier Δ {{E}\\text{b}} and zero temperature flow stress {τy0} , transitions to a near-logarithmic form for stresses in the regime 0.2<τ /{τy0}≤slant 0.5 and then transitions to a power-law form at even lower stresses τ /{τy0}<0.03 . Δ {{E}\\text{b}} and {τy0} remains as the reference energy and stress scales over the entire range of stresses. The model is applied to literature data on solution strengthening in Cu alloys and captures the experimental results quantitatively and qualitatively. Most importantly, the model accurately captures the transition in strength from the low-temperature to intermediate-temperature and the associated transition for the activation volume. Overall, the present analysis unifies the different qualitative models in the literature and, when coupled with the previous parameter-free solute strengthening model, provides a single predictive model for solute strengthening as a function of composition, temperature, and strain rate over the full range of practical utility.
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
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.
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. PMID:23987316
Volatile hydrocarbons in pharmaceutical solutions
Kroneld, R. )
1991-07-01
Volatile pollutants such as hydrocarbons have, during many years, been analysed in small concentrations in air, water, food, pharmaceutical solutions, and human blood and tissues. It has also been shown that such substances have unexpected consequences for cell cultures and scientific experiments. These substances also accumulate in patients receiving haemodialysis and these patients are exposed to quite high concentrations. The knowledge of the toxicity of such compounds has led to the development of maximum limit concentrations with the aim to decrease the exposure of humans. This paper discusses the problems of human exposure in general and especially through pharmaceutical solutions, and the possibilities of eliminating such compounds with the aim of decreasing the exposure as a hygienic challenge.
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.
Predict amine solution properties accurately
Cheng, S.; Meisen, A.; Chakma, A.
1996-02-01
Improved process design begins with using accurate physical property data. Especially in the preliminary design stage, physical property data such as density viscosity, thermal conductivity and specific heat can affect the overall performance of absorbers, heat exchangers, reboilers and pump. These properties can also influence temperature profiles in heat transfer equipment and thus control or affect the rate of amine breakdown. Aqueous-amine solution physical property data are available in graphical form. However, it is not convenient to use with computer-based calculations. Developed equations allow improved correlations of derived physical property estimates with published data. Expressions are given which can be used to estimate physical properties of methyldiethanolamine (MDEA), monoethanolamine (MEA) and diglycolamine (DGA) solutions.
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.
Strong shock implosion, approximate solution
NASA Astrophysics Data System (ADS)
Fujimoto, Y.; Mishkin, E. A.; Alejaldre, C.
1983-01-01
The self-similar, center-bound motion of a strong spherical, or cylindrical, shock wave moving through an ideal gas with a constant, γ= cp/ cv, is considered and a linearized, approximate solution is derived. An X, Y phase plane of the self-similar solution is defined and the representative curved of the system behind the shock front is replaced by a straight line connecting the mappings of the shock front with that of its tail. The reduced pressure P(ξ), density R(ξ) and velocity U1(ξ) are found in closed, quite accurate, form. Comparison with numerically obtained results, for γ= {5}/{3} and γ= {7}/{5}, is shown.
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.
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.
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.
Viscosity-stabilized aqueous solutions
Wier, D. R.
1981-01-27
Thiourea functions as a solution viscosity stabilizer in aqueous compositions comprising thiourea, nonionic polymers such as polyalkylene oxides and anionic surfactants such as petroleum sulfonates. The aqueous compositions are useful in connection with fluid-drive oil recovery processes, processes for drilling, completing, or working over wells, or the like processes in which a thickened fluid is injected into or brought into contact with a subterranean earth formation.
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.
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
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.
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.
Solute transport at fracture intersections
NASA Astrophysics Data System (ADS)
Mourzenko, V. V.; Yousefian, F.; Kolbah, B.; Thovert, J.-F.; Adler, P. M.
2002-01-01
A numerical study of three-dimensional solute transportat fracture intersections by using a particle tracking technique is presented.Two models of orthogonal fracture intersection are considered, namely, twoparallel-walled channels and two rough-walled Gaussian fractures. The fluidvelocity is calculated by solving the three-dimensional Stokes equation withno-slip boundary condition at the solid wall. Examples of individual trajectoriesof particles are first given in order to illustrate the main features of thephenomenon. Solute mass partitioning between outgoing fracture branches isconsidered for various transport regimes, characterized by the local Pécletnumber, and for various ratios of the flow rates in the intersecting channels.Generally speaking, it can be said that at dominant diffusion the influenceof the flow rates ratio is weak, while it is important in the opposite situation.Validity of the classical models of solute mixing, stream tube routing, andperfect mixing is analyzed by comparing their predictions with the numericaldata. Preliminary recommendations are made for the use of these results inlarge-scale modeling.
Dynamics in Multicomponent Polyelectrolyte Solutions
NASA Astrophysics Data System (ADS)
Nagao, Michihiro
2010-03-01
Double-network hydrogels (DN-gel) prepared from the combination of a moderately cross-linked anionic polyelectrolyte (poly(2-acrylamido-2-methyl-1-propanesulfonic acid), PAMPS) and an un-cross-linked linear polymer (polyacrylamide, PAAm) solution show strong mechanical properties far superior to that of their individual constituents [1]. To determine the origin of the superior properties of DN-gels, we investigated the structure and the chain dynamics of model PAMPS/PAAm solution blends using small-angle neutron scattering and neutron spin-echo measurements [2]. Akcasu's dynamic scattering theory for a multicomponent system [3] is modified to include polyelectrolytes, and the resulting equation describes well the neutron spin-echo results over the entire wavevector range covered in our experiments. Parameters such as effective solvent viscosity were deduced from the measured data using the modified Akcasu equation. Both the relaxation time at large length scales (10-100 nm) and the segmental diffusion coefficient at short length scales (0.1-1 nm) or the effective solvent viscosity show good accordance with the macroscopic rheological behavior of the solution blends. [4pt] [1] J.P. Gong et al., Adv. Mater. 15, 1155 (2003). [0pt] [2] S. Lee et al., Macromolecules 42, 1293 (2009). [0pt] [2] A.Z. Akcasu, in Dynamic Liht Scattering, The Method and Some Applications; W. Brown Ed. (Oxford University Press, London 1992).
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).
Axially Symmetric Brans-Dicke-Maxwell Solutions
NASA Astrophysics Data System (ADS)
Chatterjee, S.
1981-05-01
Following a method of John and Goswami new solutions of coupled Brans-Dicke-Maxwell theory are generated from Zipoy's solutions in oblate and prolate spheroidal coordinates for source-free gravitational field. All these solutions become Euclidean at infinity. The asymptotic behavior and the singularity of the solutions are discussed and a comparative study made with the corresponding Einstein-Maxwell solutions. The possibility of a very large red shift from the boundary of the spheroids is also discussed.
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
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.
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.
Aqueous Solutions and their Interfaces
Xantheas, Sotiris S.; Voth, Gregory A.
2009-04-02
Preface of the special issue of the Journal of Physical Chemistry in conjunction with the international workshop "Aqueous Solutions and their Interfaces". The topics include the structure of liquid water, the analysis of X-ray and neutron scattering experimental data, the vibrational spectroscopy of liquid water, the structure and spectroscopy of aqueous interfaces and the development of theoretical approaches to model the structure and spectra of liquid water and interfaces. This work was supported by the US Department of Energy's Office of Basic Energy Sciences, Chemical Sciences program. Pacific Northwest National Laboratory is operated by Battelle for DOE.
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.
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.
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.
Turning Disciplinary Knowledge into Solutions
Gehlert, Sarah
2013-01-01
Turning disciplinary knowledge about preadolescents’ and adolescents’ exposure to risk factors for cancer as adults into solutions for preventing such an outcome requires that investigators from a variety of backgrounds and disciplines come together to share knowledge. Optimally, these collaborations would occur across two dimensions: (1) transdisciplinary, from the molecular or cellular level (e.g., animal studies of endocrine disruption) to the societal level (e.g., economic studies related to state tobacco policies), and (2) translational, using basic research findings in clinical and other sciences to implement prevention programs and public policy. Only when collaboration is commonplace can the disparate groups of investigators working on cancer prevention during pre-adolescence and adolescence gain a holistic picture of the risk factors, inform one another’s work, and learn what we need to know to devise successful interventions for preventing cancer. Working transdisciplinarily also helps to ensure that messages to health professionals, policymakers, the news media, and the public are consistent and coordinated. At present, those investigating preadolescent and adolescent risk for adult cancer disseminate their knowledge individually, thus missing the opportunity to synthesize knowledge, coordinate dissemination, and implement prevention programs. In this paper, we distinguish multidisciplinary, interdisciplinary, and transdisciplinary approaches, argue for the benefits of a transdisciplinary approach to devising successful solutions and how to achieve transdisciplinary functioning. PMID:23601619
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.
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.
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 ...
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.
Bag For Formulating And Dispersing Intravenous Solution
NASA Technical Reports Server (NTRS)
Kipp, Jim; Owens, Jim; Scharf, Mike; Finley, Mike; Dudar, Tom; Veillon, Joe; Ogle, Jim
1993-01-01
Large-volume parenteral (LVP) bag in which predetermined amount of sterile solution formulated by combining premeasured, prepackaged amount of sterile solute with predetermined amount of water. Bag designed to hold predetermined amount, typically 1 L, of sterile solution. Sterility of solution maintained during mixing by passing water into bag through sterilizing filter. System used in field or hospitals not having proper sterile facilities, and in field research.
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.
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.
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.
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.
21 CFR 522.1450 - 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. 522.1450 Section 522.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Moxidectin solution. (a) Specifications. Each milliliter of solution contains 10 milligrams (mg)...
21 CFR 522.1086 - Guaifenesin solution.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Guaifenesin solution. 522.1086 Section 522.1086 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Guaifenesin solution. (a) Specifications. Each milliliter of solution contains 50 milligrams (mg)...
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 522.1450 - Moxidectin solution.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Moxidectin solution. 522.1450 Section 522.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Moxidectin solution. (a) Specifications. Each milliliter of solution contains 10 milligrams (mg)...
21 CFR 522.1156 - Imidocarb solution.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Imidocarb solution. 522.1156 Section 522.1156 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Imidocarb solution. (a) Specifications. Each milliliter of solution contains 120 milligrams (mg)...
21 CFR 522.1450 - Moxidectin solution.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Moxidectin solution. 522.1450 Section 522.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Moxidectin solution. (a) Specifications. Each milliliter of solution contains 10 milligrams (mg)...
21 CFR 520.1454 - Moxidectin solution.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 6 2013-04-01 2013-04-01 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...
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.
Exact Interior Solutions for Charged Fluid Spheres
NASA Astrophysics Data System (ADS)
Patel, L. K.; Tikekar, R.; Sabu, M. C.
1997-04-01
A new method is discussed to obtain the interior solution of Einstein-Maxwell equations for a charged static sphere from a known particular solutions of a similar kind. Beginning with a charged fluid interior solution reported by Patel and Pandya [11], a new interior Reissner-Nordström metric is obtained using this method and physical aspects of it are extensively discussed.
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.
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 522.690 - Dinoprost solution.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Dinoprost solution. 522.690 Section 522.690 Food... Dinoprost solution. (a) Specifications. Each milliliter (mL) of solution contains dinoprost tromethamine... skin should be washed off immediately with soap and water. (d) Conditions of use—(1) Horses—(i)...
21 CFR 522.690 - Dinoprost solution.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Dinoprost solution. 522.690 Section 522.690 Food... Dinoprost solution. (a) Specifications. Each milliliter (mL) of solution contains dinoprost tromethamine... skin should be washed off immediately with soap and water. (d) Conditions of use—(1) Horses—(i)...
21 CFR 522.690 - Dinoprost solution.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Dinoprost solution. 522.690 Section 522.690 Food... Dinoprost solution. (a) Specifications. Each milliliter (mL) of solution contains dinoprost tromethamine... skin should be washed off immediately with soap and water. (d) Conditions of use—(1) Horses—(i)...
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... Euthanasia solution. (a) Specifications. Each milliliter (mL) of solution contains: (1) 390 milligrams (mg.... For humane, painless, and rapid euthanasia. (2) Amount. One mL per 10 pounds of body weight....
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)...
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)...
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)...
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)...
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)...
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…
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... Euthanasia solution. (a) Specifications. Each milliliter (mL) of solution contains: (1) 390 milligrams (mg.... For humane, painless, and rapid euthanasia. (2) Amount. One mL per 10 pounds of body weight....
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... Euthanasia solution. (a) Specifications. Each milliliter (mL) of solution contains: (1) 390 milligrams (mg.... For humane, painless, and rapid euthanasia. (2) Amount. One mL per 10 pounds of body weight....
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... Euthanasia solution. (a) Specifications. Each milliliter (mL) of solution contains: (1) 390 milligrams (mg.... For humane, painless, and rapid euthanasia. (2) Amount. One mL per 10 pounds of body weight....
21 CFR 522.900 - Euthanasia solution.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Euthanasia solution. 522.900 Section 522.900 Food... Euthanasia solution. (a) Specifications. Each milliliter (mL) of solution contains: (1) 390 milligrams (mg.... For humane, painless, and rapid euthanasia. (2) Amount. One mL per 10 pounds of body weight....
Solution synthesis of germanium nanocrystals
Gerung, Henry; Boyle, Timothy J.; Bunge, Scott D.
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.
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.
Singlet exciton fission in solution
NASA Astrophysics Data System (ADS)
Walker, Brian J.; Musser, Andrew J.; Beljonne, David; Friend, Richard H.
2013-12-01
Singlet exciton fission, the spin-conserving process that produces two triplet excited states from one photoexcited singlet state, is a means to circumvent the Shockley-Queisser limit in single-junction solar cells. Although the process through which singlet fission occurs is not well characterized, some local order is thought to be necessary for intermolecular coupling. Here, we report a triplet yield of 200% and triplet formation rates approaching the diffusion limit in solutions of bis(triisopropylsilylethynyl (TIPS)) pentacene. We observe a transient bound excimer intermediate, formed by the collision of one photoexcited and one ground-state TIPS-pentacene molecule. The intermediate breaks up when the two triplets separate to each TIPS-pentacene molecule. This efficient system is a model for future singlet-fission materials and for disordered device components that produce cascades of excited states from sunlight.
Singlet exciton fission in solution.
Walker, Brian J; Musser, Andrew J; Beljonne, David; Friend, Richard H
2013-12-01
Singlet exciton fission, the spin-conserving process that produces two triplet excited states from one photoexcited singlet state, is a means to circumvent the Shockley-Queisser limit in single-junction solar cells. Although the process through which singlet fission occurs is not well characterized, some local order is thought to be necessary for intermolecular coupling. Here, we report a triplet yield of 200% and triplet formation rates approaching the diffusion limit in solutions of bis(triisopropylsilylethynyl (TIPS)) pentacene. We observe a transient bound excimer intermediate, formed by the collision of one photoexcited and one ground-state TIPS-pentacene molecule. The intermediate breaks up when the two triplets separate to each TIPS-pentacene molecule. This efficient system is a model for future singlet-fission materials and for disordered device components that produce cascades of excited states from sunlight. PMID:24256865
Compressor solves solution gas bottleneck
Vargas, K.J.; Lowe, F.
1996-08-05
A new turbine-driven, centrifugal compressor installation increased gas handling capacity in the Westerose D-3 oil reservoir, about 100 km south of Edmonton. Gulf Canada Resources Ltd.`s Westerose D-3 oil reservoir has prolifically produced oil for the last 3 decades. Produced gas has been reinjected into the gas cap to maintain heterogeneity and reservoir fluid interfaces. As oil production continues, increased quantities of solution gas must be handled by the Westerose facility. The cost-effective design of the new compressor installation was based on Gulf`s aggressive drilling program for recovering oil as quickly and economically as possible to reach full blowdown. The paper describes the design considerations, auxiliary equipment, costs, process flow, construction contracts, equipment and systems, and startup.
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. PMID:27199415
Liquid crystal nanodroplets in solution
NASA Astrophysics Data System (ADS)
Brown, W. Michael; Petersen, Matt K.; Plimpton, Steven J.; Grest, Gary S.
2009-01-01
The aggregation of liquid crystal nanodroplets from a homogeneous solution is studied by molecular dynamics simulations. The liquid crystal particles are modeled as elongated ellipsoidal Gay-Berne particles while the solvent is modeled as spherical Lennard-Jones particles. Extending previous studies of Berardi et al. [J. Chem. Phys. 126, 044905 (2007)], we find that liquid crystal nanodroplets are not stable and that after sufficiently long times the nanodroplets always aggregate into a single large droplet. Results describing the droplet shape and orientation for different temperatures and shear rates are presented. The implementation of the Gay-Berne potential for biaxial ellipsoidal particles in a parallel molecular dynamics code is also briefly discussed.
Liquid crystal nanodroplets in solution.
Brown, W Michael; Petersen, Matt K; Plimpton, Steven J; Grest, Gary S
2009-01-28
The aggregation of liquid crystal nanodroplets from a homogeneous solution is studied by molecular dynamics simulations. The liquid crystal particles are modeled as elongated ellipsoidal Gay-Berne particles while the solvent is modeled as spherical Lennard-Jones particles. Extending previous studies of Berardi et al. [J. Chem. Phys. 126, 044905 (2007)], we find that liquid crystal nanodroplets are not stable and that after sufficiently long times the nanodroplets always aggregate into a single large droplet. Results describing the droplet shape and orientation for different temperatures and shear rates are presented. The implementation of the Gay-Berne potential for biaxial ellipsoidal particles in a parallel molecular dynamics code is also briefly discussed. PMID:19191407
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.
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.
Counting solutions from finite samplings.
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. PMID:22463290
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.
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
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.
Linearized multipole solutions and their representation
NASA Astrophysics Data System (ADS)
Hernández-Pastora, J. L.
2013-09-01
The monopole solution of the Einstein vacuum field equations (Schwarzschild’s solution) in Weyl coordinates involves a metric function that can be interpreted as the gravitational potential of a bar of length 2 m with constant linear density. The question addressed in this work is whether similar representations can be constructed for Weyl solutions other than the spherically symmetric one. A new family of static solutions of the axisymmetric vacuum field equations generalizing the M-Q(1) solution (Hernández-Pastora and Martín 1993 Class. Quantum Grav.10 2581) is developed. These represent slight deviations from spherical symmetry in terms of the relativistic multipole moments (RMM) we wish the solution to contain. A Newtonian object referred to as a dumbbell can be used to describe these solutions in a simple form by means of the density of this object, since the physical properties of the relativistic solution are characterized by its behaviour. The density profile of the dumbbell, which is given in terms of the RMM of the solution, allows us to distinguish general multipole Weyl solutions from the constant-density Schwarzschild solution. The range of values of the multipole moments that generate positive-definite density profiles is also calculated. The bounds on the multipole moments that arise from this density condition are identical to those required for a well-behaved infinite-redshift surface g00 = 0.
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.
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.
Hyperosmolar cold storage kidney preservative solution.
Masuda, J Y; Bleich, R N; Beckerman, J H
1975-04-01
A hyperosmolar kidney preservative solution which can maintain kidneys from experimental animals viable for up to 72 hours is described. Using the criterion of a one-month failure rate, the cold storage preservation method was found to be superior to machine preservation methods. Sachs' solution was found to be superior to all other cold storage solutions. The most important aspect of the hyperosmolar kidney preservative solution appears to be its ability to maintain normal intracellular electrolyte composition and to prevent cellular damage due to swelling. The present formula requires that the basic solution and a magnesium chloride additive solution be prepared separately and combined before use. A stable combined solution is proposed which can be sterilized by membrane filtration. PMID:1130414
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
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.
Solution equilibria of deferoxamine amides.
Ihnat, Peter M; Vennerstrom, Jonathan L; Robinson, Dennis H
2002-07-01
The physico-chemical solution properties of deferoxamine were modified by acylating the terminal amino group with short-chain aliphatic, succinic, and methylsulphonic moieties. The analog iron(III)-binding constants and stabilities under physiological conditions were determined to confirm that the iron binding ability of the parent molecule was retained following modification. The proton dissociation constants of the lipophilic deferoxamine analogs were determined by potentiometric titration and nonlinear least-squares analysis. However, because the iron(III) binding complex is fully formed below pH 2, the metal-ligand equilibria could not be studied using potentiometric methods. The iron binding constants of the deferoxamine analogs were determined by spectrophotometrically following the proton-dependent exchange of iron with EDTA in the pH range of 4.0 to 6.5 and solving mass balance equations. The proton-dissociation constants and the iron binding constants of the lipophilic deferoxamine analogs were comparable to those of deferoxamine. However, at physiological conditions, the iron-binding complex of the most lipophilic butylamide derivative was slightly less stable and the succinamide derivative complex was slightly more stable. Like deferoxamine, the hydroxamate groups of the analogs were unhindered and free to form a 1:1 coordination complex with iron(III). Consequently, changes in aqueous solvation, conformation, and steric interference, imparted by the modifications at the terminal amino group of deferoxamine, may have affected the stabilities of the iron(III) complex and the efficiency of iron binding. PMID:12115836
One solution for two problems.
This article presents Dr. Nicky Padayachee's resolution concerning AIDS and its effect on the problem of overpopulation. Dr. Nicky Padayachee of Johannesburg City Council's Health Department stated that both of these problems pose a threat to the economic development with solutions depending on the development of the country. The increasing population of South Africa in comparison with its economic decline resulted to unemployment and high fertility. It has been proposed that the local government should double its efforts in the promotion of family planning through the provision of electricity and using television as a mode of disseminating family planning information. Further, a strict implementation of optimal urbanization, education and general economic development opportunity for all individuals was suggested. It was estimated that 2.5-7.5 million people will be HIV-positive by the year 2005, and any long-term planning would need essential re-examination and review as the demographic situation unfolds. AIDS education was insufficient by itself to control AIDS, but the stability in education, family life and empowerment of women were important in the implementation of any AIDS prevention program. Generally, development plays a major role in the decrease of AIDS and fertility by providing individuals with opportunities and jobs. On his last statement, he concluded that the best treatment for AIDS and population growth is a job. PMID:12349359
Solution properties of polygalacturonic acid
Stoddart, R. W.; Spires, I. P. C.; Tipton, K. F.
1969-01-01
1. The specimen of polygalacturonic acid used in these studies was shown to contain very little neutral sugar, methyl ester groups or ash, and only residues of galacturonic acid. Its electrophoretic homogeneity was examined in pyridine–acetic acid buffer at pH6·5 and in borate buffer at pH9·2. The distribution of effective particle weights was shown to be fairly narrow. 2. The pH-titration curve of the polymer gave a pK value of 3·7. 3. The interaction of the polymer with Ruthenium Red was studied and titration curves were obtained for the spectral shifts associated with the formation of a complex. 4. Optical-rotatory-dispersion studies showed that the Drude constant, λc, was dependent on pH. 5. Polygalacturonic acid was shown to display non-Newtonian properties in solution and to have an anomalously high relative specific viscosity at low concentrations. 6. Studies were made of the pH-dependence of the sedimentation coefficient of the polymer. 7. These results are discussed in terms of the structure of the molecule and their relevance to the properties of pectic substances. PMID:5343801
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.
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.
Process for recovering tungsten from organic solutions
Powers, J.A.; Patton, J.C.; Christini, J.N.
1989-11-21
This patent describes on improvement in a process wherein tungsten values are extracted from an aqueous alkali metal tungstate solution containing impurities by an organic solution containing an amine extractant wherein the organic solution consists essentially of from about 6% to about 10% by volume of the amine extractant, and the balance of the organic solution being an aromatic solvent consisting essentially of a mixture of alkyl benzenes wherein the alkyl benzenes have molecular weights of 120, 134, or 148, and the total number of carbon atoms in the alkyl chains attached to the benzene ring are either 3, 4, or 5, and thereafter the tungsten values are removed from the organic solution by contacting the organic solution with a stripping agent to form a tungsten containing strip solution. The improvement comprises carrying out the stripping step in an aqueous continuous mode, and having as the stripping agent, an aqueous solution formed from ammonium metatungstate. Wherein the aqueous solution has a tungsten concentration which allows the tungsten containing strip solution to have a specific gravity of no greater than about 1.5, and sufficient ammonia to maintain the pH of the stripping agent at from about 5 to about 8.
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.
Choudhury, Niharendu; Pettitt, Bernard M.
2005-05-15
We employ constant pressure molecular dynamics simulations to investigate the effects of solute size and solute-water dispersion interactions on the salvation behavior of nanoscopic hydrpophobic model solutes in water at normal temperature and pressure. The hydration behavior around a single planar atomic model solute as well as a pair of such solutes have been considered. The hydration water structure of a model nanoscopic solute with standard Lennard-Jones interaction is shown to be significantly different from that of their purely repulsive analogues. The density of water in the first salvation shell of a Lennard-Jones solute is much higher than that of bulk water and it remains almost unchanged with the increase of the solute dimensions from one to a few nanometers. On the other hand, for a purely repulsive analogue of the above model, solute hydration behavior shows a marked solute size dependence. The contact density of water in this case decreases with the increasing dimension of the solute. We also demonstrate the effect of solute-solvent attraction on the cavity formation in the inter solute region between two solutes with an inter solute separation of 6.8A, corresponding to the first solvent separated minimum in the free energy Profile as obtained in our earlier work.
Coupled Fluid Energy Solute Transport
1992-02-13
CFEST is a Coupled Fluid, Energy, and Solute Transport code for the study of a multilayered, nonisothermal ground-water system. It can model discontinuous as well as continuous layers, time-dependent and constant source/sinks, and transient as well as steady-state flow. The finite element method is used for analyzing isothermal and nonisothermal events in a confined aquifer system. Only single-phase Darcian flow is considered. In the Cartesian coordinate system, flow in a horizontal plane, in a verticalmore » plane, or in a fully three-dimensional region can be simulated. An option also exists for the axisymmetric analysis of a vertical cross section. The code employs bilinear quadrilateral elements in all two dimensional analyses and trilinear quadrilateral solid elements in three dimensional simulations. The CFEST finite element formulation can approximate discontinuities, major breaks in slope or thickness, and fault zones in individual hydrogeologic units. The code accounts for heterogeneity in aquifer permeability and porosity and accommodates anisotropy (collinear with the Cartesian coordinates). The variation in the hydraulic properties is described on a layer-by-layer basis for the different hydrogeologic units. Initial conditions can be prescribed hydraulic head or pressure, temperature, or concentration. CFEST can be used to support site, repository, and waste package subsystem assessments. Some specific applications are regional hydrologic characterization; simulation of coupled transport of fluid, heat, and salinity in the repository region; consequence assessment due to natural disruption or human intrusion scenarios in the repository region; flow paths and travel-time estimates for transport of radionuclides; and interpretation of well and tracer tests.« less
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.)
New knotted solutions of Maxwell's equations
NASA Astrophysics Data System (ADS)
Hoyos, Carlos; Sircar, Nilanjan; Sonnenschein, Jacob
2015-06-01
In this paper we have further developed the study of topologically non-trivial solutions of vacuum electrodynamics. We have discovered a novel method of generating such solutions by applying conformal transformations with complex parameters on known solutions expressed in terms of Bateman's variables. This has enabled us to obtain a wide class of solutions from the basic configuration, such as constant electromagnetic fields and plane-waves. We have introduced a covariant formulation of Bateman's construction and discussed the conserved charges associated with the conformal group as well as a set of four types of conserved helicities. We have also given a formulation in terms of quaternions. This led to a simple map between the electromagnetic knotted and linked solutions into flat connections of SU(2) gauge theory. We have computed the corresponding Chern-Simons charge in a class of solutions and the charge takes integer values.
Determination of pressure solution shortening in sandstones
NASA Astrophysics Data System (ADS)
Onasch, Charles M.
1993-11-01
A new method for the determination of pressure solution shortening in sandstones uses the geometry of grain-to-grain interpenetrations and grains truncated against solution surfaces. These features are used to construct plots from which the magnitude and direction of the pressure solution shortening can be determined. Using simulated pressure solution deformation of artificial and natural grain populations, the new method is shown to correctly assess a variety of coaxial and non-coaxial shortenings. Although primarily intended to determine shortening, the method can also quantify extension related to growth of beards or overgrowths during pressure solution. Application of the method to naturally deformed quartz arenite samples shows that pressure solution shortening of up to 26% occurred during compaction and 22% during layer-parallel shortening.
Desiccation kinetics of biopreservation solutions in microchannels
Aksan, Alptekin; Irimia, Daniel; He, Xiaoming; Toner, Mehmet
2013-01-01
A microfluidic device was utilized to measure the viscosity gradients formed in carbohydrate solutions of biological significance during desiccation and skin formation. A complementary numerical model employed the free volume theory to predict the concentration-dependent diffusion coefficients and viscosity gradients in concentrated solutions. It was established that the glassy skin formation at the gas-liquid interface played a key role in water entrapment and the formation and persistence of very steep concentration and viscosity gradients in the desiccating solutions. The results of this study highlighted an important phenomenon that should be accounted for during isothermal drying of glass-forming solutions: solutions with high glass transition temperatures, inevitably, dry heterogeneously. In the final product, there are significant spatial variations in water and solute content affecting the storage stability. PMID:24155501
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.
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.
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.
Tack behavior of coating solutions III.
Chopra, S K; Tawashi, R
1985-07-01
The effect of finely divided solids on the tackiness of coating solutions was determined using a parallel-plate technique. Results demonstrated that the tackiness of coating solutions containing relatively low concentration of polymers augments with the increase in concentration and diminishes with the increasing particle size of finely divided solids. In contrast, the tackiness of coating solutions containing high concentrations of polymers is suppressed upon increasing the concentration and decreasing the size of finely divided solids. PMID:4032247
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.
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.
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.
Robinson-Trautman solution with scalar hair
NASA Astrophysics Data System (ADS)
Tahamtan, T.; Svítek, O.
2015-05-01
The explicit Robinson-Trautman solution with a minimally coupled free scalar field is derived and analyzed. It is shown that this solution contains curvature singularity, which is initially naked but later enveloped by the horizon. We use the quasilocal horizon definition and prove its existence in later retarded times using sub- and supersolution method combined with growth estimates. We show that the solution is generally of algebraic type II but reduces to type D in spherical symmetry.
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.
Canard solutions near a degenerate turning point
NASA Astrophysics Data System (ADS)
Forget, T.
2006-12-01
We are interested in the study of canard solutions in a singularly perturbed real first order ODE of the form epsilonu' = Ψ(x, u, a, epsilon), where epsilon > 0 is a small parameter, and a in Script R is a control parameter. An existence result for such solutions is given, and the method used in the demonstration allow us to conjecture the existence of a generalized epsilon1/(p+1)-asymptotic expansion for those solutions.
Electric birefringencies and solute conformations of arylstannanes
NASA Astrophysics Data System (ADS)
Allen, Gregory W.; Armstrong, Robert S.; Aroney, Manuel J.; Skamp, Keith R.
1986-07-01
Measurements of the infinite-dilution dipole moments and molar Kerr constants of Ph 3SnCl, Ph 3SnBr, Ph 3SnI and Ph 2SnCl 2 are reported in carbon tetrachloride solution at 298 K and for light of wavelength of 589 nm. The data are analysed to deduce the preferred solute conformations. Comparison is made with the solute stereo-structures of the C, Si and Ge analogues.
Spurious Numerical Solutions Of Differential Equations
NASA Technical Reports Server (NTRS)
Lafon, A.; Yee, H. C.
1995-01-01
Paper presents detailed study of spurious steady-state numerical solutions of differential equations that contain nonlinear source terms. Main objectives of this study are (1) to investigate how well numerical steady-state solutions of model nonlinear reaction/convection boundary-value problem mimic true steady-state solutions and (2) to relate findings of this investigation to implications for interpretation of numerical results from computational-fluid-dynamics algorithms and computer codes used to simulate reacting flows.
Geometrical and Graphical Solutions of Quadratic Equations.
ERIC Educational Resources Information Center
Hornsby, E. John, Jr.
1990-01-01
Presented are several geometrical and graphical methods of solving quadratic equations. Discussed are Greek origins, Carlyle's method, von Staudt's method, fixed graph methods and imaginary solutions. (CW)
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.
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.
Ionic solutes impact collagen scaffold bioactivity.
Pawelec, K M; Husmann, A; Wardale, R J; Best, S M; Cameron, R E
2015-02-01
The structure of ice-templated collagen scaffolds is sensitive to many factors. By adding 0.5 wt% of sodium chloride or sucrose to collagen slurries, scaffold structure could be tuned through changes in ice growth kinetics and interactions of the solute and collagen. With ionic solutes (sodium chloride) the entanglements of the collagen molecule decreased, leading to fibrous scaffolds with increased pore size and decreased attachment of chondrocytes. With non-ionic solutes (sucrose) ice growth was slowed, leading to significantly reduced pore size and up-regulated cell attachment. This highlights the large changes in structure and biological function stimulated by solutes in ice-templating systems. PMID:25649518
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)
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.
Water control well treating solution and method
Boles, J. L.; Mancillas, G.
1984-10-16
A well treating solution is shown for changing the relative permeability of a formation being treated to water. The solution is made by mixing an amphoteric polymeric material, a mutual solvent and a surface active agent in a brine carrier liquid. The well treating solution is injected into the formation at pump rates below the fracture gradient of the formation. The well is briefly shut-in, after which production can be resumed. The treating solution and method taught lower the permeability of the producing formation to water without substantially affecting the formation's permeability to oil and gas.
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
Communities of solutions in single solution clusters of a random K -satisfiability formula
NASA Astrophysics Data System (ADS)
Zhou, Haijun; Ma, Hui
2009-12-01
The solution space of a K -satisfiability (K-SAT) formula is a collection of solution clusters, each of which contains all the solutions that are mutually reachable through a sequence of single-spin flips. Knowledge of the statistical property of solution clusters is valuable for a complete understanding of the solution space structure and the computational complexity of the random K-SAT problem. This paper explores single solution clusters of random 3- and 4-SAT formulas through unbiased and biased random-walk processes and the replica-symmetric cavity method of statistical physics. We find that the giant connected component of the solution space has already formed many different communities when the constraint density of the formula is still lower than the solution space clustering transition point. Solutions of the same community are more similar with each other and more densely connected with each other than with the other solutions. The entropy density of a solution community is calculated using belief propagation and is found to be different for different communities of the same cluster. When the constraint density is beyond the clustering transition point, the same behavior is observed for the solution clusters reached by several stochastic search algorithms. Taking together, the results of this work suggest a refined picture on the evolution of the solution space structure of the random K-SAT problem; they may also be helpful for designing heuristic algorithms.
Communities of solutions in single solution clusters of a random K-satisfiability formula.
Zhou, Haijun; Ma, Hui
2009-12-01
The solution space of a K-satisfiability (K-SAT) formula is a collection of solution clusters, each of which contains all the solutions that are mutually reachable through a sequence of single-spin flips. Knowledge of the statistical property of solution clusters is valuable for a complete understanding of the solution space structure and the computational complexity of the random K-SAT problem. This paper explores single solution clusters of random 3- and 4-SAT formulas through unbiased and biased random-walk processes and the replica-symmetric cavity method of statistical physics. We find that the giant connected component of the solution space has already formed many different communities when the constraint density of the formula is still lower than the solution space clustering transition point. Solutions of the same community are more similar with each other and more densely connected with each other than with the other solutions. The entropy density of a solution community is calculated using belief propagation and is found to be different for different communities of the same cluster. When the constraint density is beyond the clustering transition point, the same behavior is observed for the solution clusters reached by several stochastic search algorithms. Taking together, the results of this work suggest a refined picture on the evolution of the solution space structure of the random K-SAT problem; they may also be helpful for designing heuristic algorithms. PMID:20365232
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. PMID:12099805
Celebrating the centenary of the Schwarzschild solutions
NASA Astrophysics Data System (ADS)
Grøn, Øyvind
2016-07-01
This article is a celebration of the centenary of Schwarzschild's presentations of his external and internal solutions describing spacetime outside and inside an incompressible, spherically symmetric body. I give a review of these solutions and how they have been interpreted physically.
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.
Analytic solutions for Dp branes in SFT
NASA Astrophysics Data System (ADS)
Bonora, L.; Giaccari, S.; Tolla, D. D.
2011-12-01
This is the follow-up of a previous paper [JHEP 08 (2011) 158] of ours, where we calculated the energy of a proposed analytic lump solution in SFT representing a D24-brane. Here we propose a similar analytic solution for a D p-brane, for any p, and compute its energy.
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.
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.)
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...
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
Zinc Bromide Waste Solution Treatment Options
Langston, C.A.
2001-01-16
The objective of this effort was to identify treatment options for 20,000 gallons of low-level radioactively contaminated zinc bromide solution currently stored in C-Area. These options will be relevant when the solutions are declared waste.
Microcellular foams prepared from demixed polymer solutions
Aubert, J.H.
1990-01-01
Low-density, microcellular polymer foams have numerous applications as structural supports in high-energy physics experiments, in catalysis, ion exchange, and filtration, and for a variety of biomedical uses. A versatile method to prepare such foams is by thermally-induced phase separation (TIPS) of polymer solutions. Demixed solutions can be transformed into a foam by freezing the demixed solution and removing the solvent by freeze-drying. The morphology of these foams is determined by the the thermodynamics and kinetics of phase separation. A model of both the early and late stage structure development for demixed polymer solutions will be presented. For semi-crystalline polymers, gels can be prepared by crystallizing the polymer from solution, either a homogeneous solution or a demixed solution. Foams can be prepared from these gels by the supercritical extraction of the solvent. By understanding and utilizing the phase separation behavior of polymer solutions, engineered microcellular foams can be prepared. To design the foams for any application one must be able to characterize their morphology. Results will be presented on the morphological characterization of these foams and the relationship of the morphology to their processing history. 14 refs., 12 figs.
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.
Colorimetric determination of tobramycin in parenteral solutions.
Das Gupta, V
1988-06-01
A colorimetric method based on a reaction between tobramycin and alkaline copper sulphate solution has been proposed to quantify tobramycin in injections. The excipients present and normal saline did not interfere with the assay procedure. A tobramycin sample which was decomposed using either sulphuric acid or sodium hydroxide solution indicated fairly good stability on both sides of the pH scale. PMID:3209627
Compact spaceflight solution crystal-growth system
NASA Technical Reports Server (NTRS)
Trolinger, James D.; Lal, Ravindra; Vikram, Chandra; Witherow, William
1991-01-01
A versatile, miniaturized, stand alone, crystal solution growth chamber design is presented which is based on fiber optics, diode lasers, and holographic optical elements in conjunction with knowledge gained from previous Spacelab work. Diagnostics instrumentation is based on a crystal growth monitor, a growth/dissolution monitor with feedback, solution diagnostics, multiple wavelength holography, and single wavelength or color Schlieren with video recording.
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...
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)
21 CFR 520.1454 - Moxidectin solution.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Moxidectin solution. 520.1454 Section 520.1454 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1454 Moxidectin solution. (a) Specifications. Each milliliter (mL)...
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)
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.
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…
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.
Electroosmotic flow hysteresis for dissimilar ionic solutions.
Lim, An Eng; Lim, Chun Yee; Lam, Yee Cheong
2015-03-01
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
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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1454 Moxidectin solution. (a) Specifications. Each milliliter (mL)...
Analytical solutions to constrained hypersonic flight trajectories
NASA Technical Reports Server (NTRS)
Lu, Ping
1992-01-01
The flight trajectory of aerospace vehicles subject to a class of path constraints is considered. The constrained dynamics is shown to be a natural two-time-scale system. Asymptotic analytical solutions are obtained. Problems of trajectory optimization and guidance can be dramatically simplified with these solutions. Applications in trajectory design for an aerospace plane strongly support the theoretical development.
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.
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
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)
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.
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)
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.
Interaction of photons with some solutions
NASA Astrophysics Data System (ADS)
Singh, Kulwant; Kaur, Gagandeep; Sandhu, G. K.; Lark, B. S.
2001-06-01
The linear attenuation coefficients in aqueous solutions of some chlorides and sulphates, viz. MgCl 2·6H 2O, CaCl 2, SrCl 2·6H 2O, BaCl 2·2H 2O, Na 2SO 4, K 2SO 4 and MgSO 4·7H 2O were determined at 81, 356, 511, 662, 1173 and 1332 keV by the γ-ray transmission method in a good geometry setup. From the precision measured densities of these solutions, mass attenuation coefficients were then obtained which varied systematically with the corresponding changes in the concentrations (g/cm 3) of these solutions. A comparison between experimental and theoretical values of attenuation coefficients has shown that the study has potential application for the determination of attenuation coefficients of solid solutes from their solutions without obtaining them in pure crystalline form.
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.
Completeness of solutions of Bethe's equations.
Hao, Wenrui; Nepomechie, Rafael I; Sommese, Andrew J
2013-11-01
We consider the Bethe equations for the isotropic spin-1/2 Heisenberg quantum spin chain with periodic boundary conditions. We formulate a conjecture for the number of solutions with pairwise distinct roots of these equations, in terms of numbers of so-called singular (or exceptional) solutions. Using homotopy continuation methods, we find all such solutions of the Bethe equations for chains of length up to 14. The numbers of these solutions are in perfect agreement with the conjecture. We also discuss an indirect method of finding solutions of the Bethe equations by solving the Baxter T-Q equation. We briefly comment on implications for thermodynamical computations based on the string hypothesis. PMID:24329220
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.
Solute concentration effect on osmotic reflection coefficient.
Adamski, R P; Anderson, J L
1983-01-01
A theory for the effect of concentration on osmotic reflection coefficient, correct to first order, was developed at the molecular level by considering the effect of solute-solute interactions on solute concentration and the fluid stress tensor within a solvent-filled pore. The solvent was modeled as a continuous fluid and potential energies between solute molecules and the pore wall were assumed to be pairwise additive. Although the theory is more general, calculations are presented only for excluded volume effects (hard-sphere for solute, hard-wall for pore). The relationship between the first-order concentration effect and the infinite dilution value of reflection coefficient appears to be geometry independent. The theory is discussed in light of experimental studies of osmotic flow that have recently appeared in the literature. PMID:6626681
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.
Process for extracting technetium from alkaline solutions
Moyer, B.A.; Sachleben, R.A.; Bonnesen, P.V.
1994-12-31
This invention relates generally to a process for extracting technetium from nuclear wastes and more particularly to a process for extracting technetium from alkaline waste solutions containing technetium and high concentrations of alkali metal nitrates. 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 comprises the steps of: contacting the aqueous alkaline solution with a solvent consisting of a crown ether in a diluent, the diluent being a water-immiscible organic liquid in which the crown ether is soluble, for a period of time sufficient to selectively extract the technetium values from the aqueous alkaline solution into the solvent; separating the solvent containing the technetium values from the aqueous alkaline solution; and stripping the technetium values from the solvent by contacting the solvent with water.
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
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.
Approximate Solutions in Planted 3-SAT
NASA Astrophysics Data System (ADS)
Hsu, Benjamin; Laumann, Christopher; Moessner, Roderich; Sondhi, Shivaji
2013-03-01
In many computational settings, there exists many instances where finding a solution requires a computing time that grows exponentially in the number of variables. Concrete examples occur in combinatorial optimization problems and cryptography in computer science or glassy systems in physics. However, while exact solutions are often known to require exponential time, a related and important question is the running time required to find approximate solutions. Treating this problem as a problem in statistical physics at finite temperature, we examine the computational running time in finding approximate solutions in 3-satisfiability for randomly generated 3-SAT instances which are guaranteed to have a solution. Analytic predictions are corroborated by numerical evidence using stochastic local search algorithms. A first order transition is found in the running time of these algorithms.
Cosmological solutions of f (T ) gravity
NASA Astrophysics Data System (ADS)
Paliathanasis, Andronikos; Barrow, John D.; Leach, P. G. L.
2016-07-01
In the cosmological scenario in f (T ) gravity, we find analytical solutions for an isotropic and homogeneous universe containing a dust fluid and radiation and for an empty anisotropic Bianchi I universe. The method that we apply is that of movable singularities of differential equations. For the isotropic universe, the solutions are expressed in terms of a Laurent expansion, while for the anisotropic universe we find a family of exact Kasner-like solutions in vacuum. Finally, we discuss when a nonlinear f (T ) -gravity theory provides solutions for the teleparallel equivalence of general relativity and derive conditions for exact solutions of general relativity to solve the field equations of an f (T ) theory.
Soliton solutions of the Hirota's system
NASA Astrophysics Data System (ADS)
Yesmakhanova, Kuralay; Shaikhova, Gaukhar; Bekova, Guldana
2016-08-01
It is well known that nonlinear integrable systems have attracted a lot of attention among researchers. This fascinating subject of nonlinear science has branched out in almost all areas of technology and science. In nonlinear science soliton solutions play an important role. There are many ways to obtain soliton solutions of the nonlinear evolution equations, such as the Painleve analysis, the Hirota's bilinear method, Darboux transformation (DT) and so on. Among the various methods, the DT has been proved very successful in driving different kinds of solutions for many of the integrable equations from a trivial seed. In this work, we focus on the construction soliton solutions for the 2+1-dimensional Hirota's system, which is modified nonlinear Schrödinger equations. One-soliton solutions are obtained by means of the one-fold Darboux transformation for the 2+1-dimensional Hirota's system.
Twisting algebraically special solutions in five dimensions
NASA Astrophysics Data System (ADS)
Bernardi de Freitas, Gabriel; Godazgar, Mahdi; Reall, Harvey S.
2016-05-01
We determine the general form of the solutions of the five-dimensional vacuum Einstein equations with cosmological constant for which (i) the Weyl tensor is everywhere type II or more special in the null alignment classification of Coley et al, and (ii) the 3 × 3 matrix encoding the expansion, shear and twist of the aligned null direction has rank 2. The dependence of the solution on two coordinates is determined explicitly, so the Einstein equation reduces to PDEs in the three remaining coordinates, just as for four-dimensional (4d) algebraically special solutions. The solutions fall into several families. One of these consists of warped products of 4d algebraically special solutions. The others are new.
Application de la technologie des materiaux sol-gel et polymere a l'optique integree
NASA Astrophysics Data System (ADS)
Saddiki, Zakaria
2002-01-01
With the advancement of optical telecommunication systems, "integrated optics" and "optical interconnect" technology are becoming more and more important. The major components of these two technologies are photonic integrated circuits (PICs), optoelectronic integrated circuits (OEICs), and optoelectronic multichip modules ( OE-MCMs). Optical signals are transmitted through optical waveguides that interconnect such components. The principle of optical transmission in waveguides is the same as that in optical fibres. To implement these technologies, both passive and active optical devices are needed. A wide variety of optical materials has been studied, e.g., glasses, lithium niobate, III-V semiconductors, sol-gel and polymers. In particular, passive optical components have been fabricated using glass optical waveguides by ion-exchange, or by flame hydrolysis deposition and reactive ion etching (FHD and RIE ). When using FHD and RIE, a very high temperatures (up to 1300°C) are needed to consolidate silica. This work reports on the fabrication and characterization of a new photo-patternable hybrid organic-inorganic glass sol-gel and polymer materials for the realisation of integrated optic and opto-electronic devices. They exhibit low losses in the NIR range, especially at the most important wavelengths windows for optical communications (1320 nm and 1550 nm). The sol-gel and polymer process is based on photo polymerization and thermo polymerization effects to create the wave-guide. The single-layer film is at low temperature and deep UV-light is employed to make the wave-guide by means of the well-known photolithography process. Like any photo-imaging process, the UV energy should exceed the threshold energy of chemical bonds in the photoactive component of hybrid glass material to form the expected integrated optic pattern with excellent line width control and vertical sidewalls. To achieve optical wave-guide, a refractive index difference Delta n occurred between the isolated (guiding layer) and the surrounding region (buffer and cladding). Accordingly, the refractive index emerges as a fundamental device performance material parameter and it is investigated using slab wave-guide. (Abstract shortened by UMI.)
Tomographie par coherence optique pour le guidage de chirurgies minimalement invasives du rachis
NASA Astrophysics Data System (ADS)
Beaudette, Kathy
Adolescent idiopathic scoliosis is a complex 3D deformity of the spine which requires surgical intervention in severe cases of the condition. The existing corrective procedure of scoliosis is very invasive; it involves a long incision and a large instrumentation, in addition to the fusion of a section of the spine. To improve postoperative conditions and to preserve patients' spinal flexibility, novel fusionless surgical approaches involving growth modulation are under investigation. With this objective in mind, a multidisciplinary team from École Polytechnique of Montreal and Sainte-Justine University Hospital Research Center is developing a surgical technique based on the insertion of micro-staples between vertebral growth plates and corresponding intervertebral disks. Each micro-staple passively modulates the vertebral growth on the convex side of the scoliotic curvature. This modulation modifies vertebral geometry which, for scoliotic patients, presents a wedging deformity. The modulation induced by these devices could lead to the correction of the curvature of the spine. This innovative procedure would preserve the flexibility of the spine as well as the health of intervertebral disks, in addition to being compatible with minimally invasive approaches. However, to be efficient, the micro-staples must be placed at the junction between the growth plate and the disk with a sub-millimeter precision. An intraoperative guiding system is therefore required to ensure the success of the intervention. Optical coherence tomography (OCT) is a promising candidate for this application. OCT is based on low-coherence interferometry and provides cross-sectional images with a resolution about 10 μm for a depth of 2 to 3 mm. This technique allows for the real-time acquisition of images and is compatible with endoscopy, thereby showing a potential for the intraoperative guidance of minimally invasive surgeries (MIS) of the spine. The main objective of this master's project is therefore to evaluate the possibility of using OCT to localize as well as identify spinal structures (such as growth plates, osseous tissue, intervertebral disks and connective tissue) and to guide the insertion of micro-staples. To attain this objective, an OCT handheld probe was designed and developed according to the surgical constraints of MIS performed by thoracoscopy (through the thorax). This probe has an external diameter of 17 mm and is 30 cm long. Coupled with a fibered interferometer, the axial and lateral resolutions of the probe are of 16 and 27 μm respectively. The OCT probe was used in vivo during an open surgery on a porcine model. Different tissues within the operative window (lung, muscles, osseous tissues and intervertebral disk) were imaged during the procedure. These preliminary in vivo tests demonstrated that the probe is capable of identifying different types of tissue with a good sensitivity and an adequate penetration depth. These results also showed that a visual inspection of the in vivo OCT images alone is not sufficient to localize the growth plates on the vertebrae. An ex vivo study using porcine vertebrae was therefore performed to identify quantitative markers in order to facilitate the interpretation of in vivo OCT images. OCT images were initially compared to corresponding histological sections. The ensuing results showed that the connective tissue layer presents a band pattern due to the birefringence properties of the collagen-rich tissue. The intervertebral disk was also shown to have a characteristic lamellar structure on OCT images. Lastly, within growth plate and osseous tissue locations, the OCT signal decay is monotonic, but with different attenuation coefficients (different slopes). Relative attenuation coefficients were therefore measured for each tissue (growth plate, osseous tissue, connective tissue and intervertebral disk) on several specimens and were compared. These results showed that growth plates present an average relative attenuation coefficient statistically different from the other tissues. An automatic growth plate segmentation algorithm was then developed and tested. The algorithm was applied to images from an ex vivo specimen of a porcine vertebra and successfully identified most of the growth plate (> 75%) amidst the osseous tissue of the vertebral body and the intervertebral disk. This master's project shows that OCT presents contrast, resolution and penetration depth that are sufficient for the identification of musculoskeletal structures of the spine. It is thus reasonable to believe that, ultimately, OCT could be used for the intraoperative guiding of the insertion of micro-staples during corrective surgeries of scoliosis.
Depth in colour, a history of a chapter in physiologie optique amusante.
Vos, Johannes J
2008-03-01
Two centuries ago, Goethe wrote in his Farbenlehre about blue as a receding colour, against yellow/red as a colour 'piercing into the organ'. Though any verification of these psychological attributes seems to be absent, this depth effect in colour still seems to be taken for granted in art history. In visual science, the completely different and far better documented colour stereoscopic effect, known as chromostereopsis, prevails. A historical account is given of the development of ideas about this chromostereopsis, often by amusing trials and errors. The original explanation by Bruecke in terms of chromatic aberration (in present-day literature usually indicated as transverse chromatic aberration) and a temporal off-axis position of the fovea still forms the basis of present-day understanding, even though Bruecke rejected his own explanation. It had to be complemented by an additional off-axis effect of the pupil, not in an anatomical sense, as Einthoven presumed but failed to find but in a functional sense by a non-centric Stiles-Crawford effect. Although a comprehensive individual experimental proof is still missing, the evidence available indicates that a satisfactory quantitative explanation has been reached. PMID:18271777
Proprietes optiques lineaires et non-lineaires de nanocomposites metal/dielectrique anisotropes
NASA Astrophysics Data System (ADS)
Lamarre, Jean-Michel
In this thesis, we present the development and the analysis of advanced fabrication techniques allowing for the precise control of the synthesis of nanocomposites formed of gold nanoparticles embedded in a silica matrix. We have developed a three-step technique allowing us to fabricate nanocomposite films with particles of controlled size and shape. (1) The first paper describes the sample fabrication method and their linear optical properties. The nanocomposite materials are first deposited using a PECVD/sputtering hybrid technique. In order to increase the nanoparticule size, the sample are then submitted to a 900°C thermal annealing for several hours. The modification technique used to change the particles from spheres to ellipsoids is described. This technique consists of irradiating the samples using high energy copper ions (30 MeV). The resulting structure is anisotropic since the particles' long axis are aligned with the irradiation direction. This is the first use of this technique for samples with gold particles embedded in a solid matrix. The details of the ellipsometric and spectrophotometric characterization are discussed and the linear optical properties of these materials measured by these techniques are presented. These measurements allow one to find the nanostructural parameters of the layer (gold concentration, particle size, thickness and surface roughness) from the complex refractive index of the layer. We demonstrate the effect of the annealing and the irradiation on the optical properties of the nanocomposite system notably on the control of the characteristics of the SPR absorption band. Thus, we show that the thermal annealing induce a red-shift in the SPR position while the irradiation step corresponds to a blue-shift. We also demonstrate that a final post-irradiation annealing treatment allows to re-form spherical nanoparticles. (2) The second paper is focused on the nonlinear optical properties of Au/SiO2 nanocomposites. Polarized P-Scan et Z-Scan techniques adapted for the measurements of anisotropic samples are described. The P-Scan technique linearity in the context of high power measurements of nanocomposite samples is discussed by comparing several models (model of saturable absorption, correction for linear absorption, correction for linear and nonlinear absorption). Isotropic (spheres) and anisotropic (nanoellipsoids) nanocomposite samples were measured by the Z-Scan and P-Scan techniques. The measurements of isotropic samples yield a nonlinear absorption coefficient value of --4.8x10 -2 cm/W while the measurements of the nonlinear absorption coefficient of anisotropic samples yield values ranging between --0.9x10 -2 cm/W and --3.0x10-2 cm/W depending on the polarization direction of the measurement light. This change in polarization corresponds to a variation of the excitation of the nanoellipsoids short and long axes. Using a simple geometrical model, we show that the nonlinear absorption coefficient measured for a polarization along the ellipsoids short or long axis is equal respectively to --0.9x10-2 cm/W and --5.1x10-2 cm/W. (3) The third paper deals with improvements to the currently used model for the nonlinear response of nanocomposite samples. These modifications allows one to model high metal concentration samples and/or samples containing anisotropic particles. The introduction of the depolarization factor in the calculation of the effective nonlinear susceptibility of nanocomposites from the generalized Maxwell-Garnett equation allows for the addition of a parameter which depends on the geometry of the nanoparticles. The modified model for high gold concentration is compared to the traditional model. We show that the use of the modified model is of prime importance for gold volume fractions exceeding 1%. The effect of each parameter of the model is evaluated and discussed (metal concentration, metal dielectric constant, matrix dielectric constant, metal nonlinear susceptibility). We demonstrate that each fabrication parameter must be carefully choosen as a function of the particle geometry in order to optimize the optical nonlinearity value. The use of this improved model for the prediction of real sample properties is discussed notably in the context of the results introduced in the preceding paper. The model we developped allows one to predict and understand the values of the nonlinear absorption coefficient measured along the nanoellipsoids short and long axes. Finally, we show that the maximum anisotropy of the nonlinear optical properties is not necessarily obtained for particles with maximum deformation. (Abstract shortened by UMI.)
Etude methodologique de l'imagerie optique diffuse couplee a l'electroencephalographie
NASA Astrophysics Data System (ADS)
Chapuisat, Sarah
Diffuse Optical Imaging (DOI) and electroencephalography (EEG) are two complementary functional brain imaging modalities: they do not image the same physiological phenomenon, but their spatial and temporal resolutions are of the same order of magnitude. Because the relationship between electrical (as measured by EEG) and hemodynamic (as measured by DOI) activities is still poorly understood, being able to record EEG and DOI data simultaneously appears necessary. On the experimental side, the aim of this project was to adapt an EEG cap to introduce optical fibers and thus, record DOI and EEG simultaneously. A study of the activations in the premotor and motor cortices, involved in movement preparation, allowed us to validate the acquisition setup, which nevertheless needs to be further improved. The theoretical part of this work focused on the use of regions reconstructed from DOI data as a spatial prior for the resolution of the inverse problem in EEG (i.e. the source location) via a Bayesian model. Simulation data gave us an accurate assessment of the contribution of DOI data and showed in particular that the use of a prior improved the amplitude of the reconstructed EEG sources. This study also showed that, regardless of the spatial coherence between DOI and EEG activities, the use of DOI prior did not worsen the EEG reconstruction. Although both the theoretical model and the acquisition system remain to be improved, this work showed the interest and feasibility of simultaneous EEG and DOI acquisition. Key words: diffuse optical imaging, near infrared spectroscopy, electroencephalography, movement preparation, Bayesian estimation
An anti-Schwarzshild solution: Wormholes and scalar-tensor solutions
NASA Astrophysics Data System (ADS)
Mimoso, José P.; Lobo, Francisco S. N.
2010-05-01
We investigate a static solution with an hyperbolic nature, characterised by a pseudo-spherical foliation of space. This space-time metric can be perceived as an anti-Schwarzschild solution, and exhibits repulsive features. It belongs to the class of static vacuum solutions termed "a degenerate static solution of class A" (see [1]). In the present work we review its fundamental features, discuss the existence of generalised wormholes, and derive its extension to scalar-tensor gravity theories in general.
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…
VLBI-SLR Combination Solution Using GEODYN
NASA Astrophysics Data System (ADS)
MacMillan, D. S.; Lemoine, F. G.; Chinn, D. S.; Pavlis, E. C.; Rowlands, D. D.
2009-12-01
The traditional procedure followed by the IERS for generating an ITRF is to perform a combination at the technique level. Each geodetic technique provides a solution that itself is a combination of the solutions produced by the technique analysis centers. Alternatively, we would like to generate a multi-technique solution using the same software and using the same a priori models. We seek to produce such a solution combining all of the geodetic techniques at the normal equation level using GEODYN but here, as a first step, consider only the SLR-VLBI combination. The data from each 24-hour VLBI session is initially processed to generate VLBI observation and solution parametrization files for input to GEODYN. Extensive tests have been performed to ensure that the VLBI theoretical delay as calculated by the VLBI Calc/Solve software is the same (to 1 ps) as that calculated by GEODYN. Initially, we ran test solutions with GEODYN using only VLBI data to verify that VLBI solution results produced with GEODYN agree with results using Calc/Solve. Then we combine the VLBI normal equations in GEODYN with weekly SLR normal equations for the period 2004-2008 Lageos1/2 to estimate station positions and Earth orientation parameters. To connect the techniques, we apply the ground ties used by the IERS. Here we report on the results of the combination.
Americium separations from high salt solutions
Mary E. Barr; Gordon D. Jarvinen; Louis D. Schulte; Peter C. Stark; Rebecca M. Chamberlin; Kent D. Abney; Thomas E. Ricketts; Yvette E. Valdez; Richard A. Bartsch
2000-03-01
Americium (III) exhibits an unexpectedly high affinity for anion-exchange material from the high-salt evaporator bottoms solutions--an effect which has not been duplicated using simple salt solutions. Similar behavior is observed for its lanthanide homologue, Nd(III), in complex evaporator bottoms surrogate solutions. There appears to be no single controlling factor--acid concentration, total nitrate concentration or solution ionic strength--which accounts for the approximately 2-fold increase in retention of the trivalent ions from complex solutions relative to simple solutions. Calculation of species activities (i.e., water, proton and nitrate) in such concentrated mixed salt solutions is difficult and of questionable accuracy, but it is likely that the answer to forcing formation of anionic nitrate complexes of americium lies in the relative activities of water and nitrate. From a practical viewpoint, the modest americium removal needs (ca. 50--75%) from nitric acid evaporator bottoms allow sufficient latitude for the use of non-optimized conditions such as running existing columns filled with older, well-used Reillex HPQ. Newer materials, such as HPQ-100 and the experimental bifunctional resins, which exhibit higher distribution coefficients, would allow for either increased Am removal or the use of smaller columns. It is also of interest that one of the experimental neutral-donor solid-support extractants, DHDECMP, exhibits a similarly high level of americium (total alpha) removal from EV bottoms and is much less sensitive to total acid content than commercially-available material.
Compatibility considerations in parenteral nutrient solutions.
Niemiec, P W; Vanderveen, T W
1984-05-01
Information on compatibility of nutrients and drugs with parenteral nutrient (PN) solutions is reviewed and evaluated. Precipitation of calcium phosphate when calcium and phosphate salts are added can be affected by pH, amino acid concentration, amino acid product, temperature, sequence of additives, specific salt used, and time since admixture; precipitate formation can occur gradually over 24 hours. Insulin is chemically stable in PN solutions, but adsorption to the infusion system can cause decreased availability. Poor delivery of vitamin A via PN solutions has been reported. The sodium bisulfite content of amino acid injections may cause degradation of thiamine, but studies simulating clinical use are needed. Folic acid stability in PN solutions has been demonstrated, and phytonadione appears to be stable. Drug administration via PN solutions may be advantageous when fluid intake is restricted or peripheral vein access is limited and in home PN therapy. Summarized are results of studies involving heparin, cimetidine hydrochloride, aminophylline, amphotericin B, iron dextran, hydrochloric acid, corticosteroids, narcotics, metoclopramide, digoxin, and fluorouracil. Many antibiotics are probably stable, especially when administered by co-infusion rather than by direct mixture in the PN solution container. When lipids are mixed in the same container with amino acid-dextrose solutions, compatibility and stability of electrolytes, vitamins, and trace elements must be reassessed. Practical research is needed, and availability of additives should be studied in specific patient populations and for specific PN formulations. Valid conclusions are dependent on careful study design. PMID:6328980
Solute drag on perfect and extended dislocations
NASA Astrophysics Data System (ADS)
Sills, R. B.; Cai, W.
2016-04-01
The drag force exerted on a moving dislocation by a field of mobile solutes is studied in the steady state. The drag force is numerically calculated as a function of the dislocation velocity for both perfect and extended dislocations. The sensitivity of the non-dimensionalized force-velocity curve to the various controlling parameters is assessed, and an approximate analytical force-velocity expression is given. A non-dimensional parameter S characterizing the strength of the solute-dislocation interaction, the background solute fraction ?, and the dislocation character angle ?, are found to have the strongest influence on the force-velocity curve. Within the model considered here, a perfect screw dislocation experiences no solute drag, but an extended screw dislocation experiences a non-zero drag force that is about 10 to 30% of the drag on an extended edge dislocation. The solutes can change the spacing between the Shockley partials in both stationary and moving extended dislocations, even when the stacking fault energy remains unaltered. Under certain conditions, the solutes destabilize an extended dislocation by either collapsing it into a perfect dislocation or causing the partials to separate unboundedly. It is proposed that the latter instability may lead to the formation of large faulted areas and deformation twins in low stacking fault energy materials containing solutes, consistent with experimental observations of copper and stainless steel containing hydrogen.
Graft preservation solutions in cardiovascular surgery.
Winkler, Bernhard; Reineke, David; Heinisch, Paul Philip; Schönhoff, Florian; Huber, Christoph; Kadner, Alexander; Englberger, Lars; Carrel, Thierry
2016-08-01
Vein grafts are still the most commonly used graft material in cardiovascular surgery and much effort has been spent in recent years on investigating the optimal harvesting technique. One other related topic of similar importance remained more or less an incidental one. The storage solutions of vein grafts following procurement and prior to implantation are, despite their assumed impact, a relatively neglected theme. There is no doubt that the endothelium plays a key role in long-term patency of vein grafts, but the effects of the different storage solutions on the endothelium remain unclear : In a review of the literature, we could find 20 specific papers that addressed the question, of which the currently available preservation solutions are superior, harmless, damaging or ineffective. The focus lies on saline and autologous whole blood. Besides these two storage media, novel or alternative solutions have been investigated with surprising findings. In addition, a few words will be spent on potential alternatives and novel solutions on the market. As there is currently no randomized clinical trial regarding saline versus autologous whole blood available, this review compares all previous studies and methods of analysis to provide a certain level of evidence on this topic. In summary, saline has negative effects on the endothelial layers and therefore may compromise graft patency. Related factors, such as distension pressure, may outbalance the initial benefit of autologous whole blood or storage solutions and intensify the harmful effects of warm saline. In addition, there is no uniform consent on the superiority of autologous whole blood for vein graft storage. This may open the door to alternatives such as the University of Wisconsin solution or one of the specific designed storage solutions like TiProtec™ or Somaluthion™. Whether these preservation solutions are superior or advantageous remains the subject of further studies. PMID:27068248
Slow continuous ultrafiltration with bound solute dialysis.
Patzer, John F; Safta, Stefan A; Miller, Richard H
2006-01-01
Bound solute dialysis (BSD), often referred to as "albumin dialysis" (practiced clinically as the molecular adsorbents recirculating system, MARS, or single-pass albumin dialysis, SPAD) or "sorbent dialysis" (practiced clinically as the charcoal-based Biologic-DT), is based upon the thermodynamic principle that the driving force for solute mass transfer across a dialysis membrane is the difference in free solute concentration across the membrane. The clinically relevant practice of slow continuous ultrafiltration (SCUF) for maintenance of patients with liver failure is analyzed in conjunction with BSD. The primary dimensionless operating parameters that describe SCUF-BSD include (1) beta, the dialysate/blood binder concentration ratio; (2) kappa, the dialyzer mass transfer/blood flow rate ratio; (3) alpha, the dialysate/blood flow rate ratio; and, (4) gamma, the ultrafiltration/blood flow rate ratio. Results from mathematical modeling of solute removal during a single pass through a dialyzer and solute removal from a one-compartment model indicate that solute removal is remarkably insensitive to gamma. Solute removal approaches an asymptote (improvement in theoretical clearance over that obtainable with no binder in the dialysate) with increasing beta that is dependent on kappa and independent of alpha. The amount of binder required to approach the asymptote decreases with increasing solute-binder equilibrium constant, i.e., more strongly bound solutes require less binder in the dialysate. The results of experimental observations over a range of blood flow rates, 100 to 180 mL/min, dialysate flow rates, 600 to 2150 mL/h, ultrafiltration rates, 0 to 220 mL/h, and dialysate/blood albumin concentration ratios, beta = 0.01 to 0.04, were independently predicted remarkably well by the one-compartment model (with no adjustable parameters) based on BSD principles. PMID:16436890
Supersymmetric Kerr-anti-de Sitter solutions
Cvetic, Mirjam; Gao Peng; Simon, Joan
2005-07-15
We prove the existence of one quarter supersymmetric type IIB configurations that arise as nontrivial scaling solutions of the standard five-dimensional Kerr-anti-de Sitter black holes by the explicit construction of its Killing spinors. This neutral, spinning solution is asymptotic to the static anti-de Sitter space-time with cosmological constant -(1/l{sup 2}), it has two finite equal angular momenta J{sub 1}={+-}J{sub 2}, mass M=(1/l)(|J{sub 1}|+|J{sub 2}|) and a naked singularity. We also address the scaling limit associated with one-half supersymmetric solution with only one angular momentum.
Static scalar field solutions in symmetric gravity
NASA Astrophysics Data System (ADS)
Hossenfelder, S.
2016-09-01
We study an extension of general relativity with a second metric and an exchange symmetry between the two metrics. Such an extension might help to address some of the outstanding problems with general relativity, for example the smallness of the cosmological constant. We here derive a family of exact solutions for this theory. In this two-parameter family of solutions the gravitational field is sourced by a time-independent massless scalar field. We find that the only limit in which the scalar field entirely vanishes is flat space. The regular Schwarzschild-solution is left with a scalar field hidden in the second metric’s sector.
Novel third-order Lovelock wormhole solutions
NASA Astrophysics Data System (ADS)
Mehdizadeh, Mohammad Reza; Lobo, Francisco S. N.
2016-06-01
In this work, we consider wormhole geometries in third-order Lovelock gravity and investigate the possibility that these solutions satisfy the energy conditions. In this framework, by applying a specific equation of state, we obtain exact wormhole solutions, and by imposing suitable values for the parameters of the theory, we find that these geometries satisfy the weak energy condition in the vicinity of the throat, due to the presence of higher-order curvature terms. Finally, we trace out a numerical analysis, by assuming a specific redshift function, and find asymptotically flat solutions that satisfy the weak energy condition throughout the spacetime.
Separation of metal ions from aqueous solutions
Almon, Amy C.
1994-01-01
A process and apparatus for quantitatively and selectively separating metal ions from mixtures thereof in aqueous solution. The apparatus includes, in combination, a horizontal electrochemical flow cell containing flow bulk electrolyte solution and an aqueous, metal ion-containing solution, the cell containing a metal mesh working electrode, a counter electrode positioned downstream from the working electrode, an independent variable power supply/potentiostat positioned outside of the flow cell and connected to the electrodes, and optionally a detector such as a chromatographic detector, positioned outside the flow cell. This apparatus and its operation has significant application where trace amounts of metal ions are to be separated.
Tack behavior of coating solutions II.
Chopra, S K; Tawashi, R
1984-04-01
The tackiness of coating solutions containing high concentrations of polymers was determined using a parallel plate technique. Kinematics of the film-splitting process was also investigated using a high-speed movie camera. The results showed that the impulse required to split a liquid film of highly concentrated polymer solution (semisolid), in contrast to a dilute solution is related not to viscosity, but to the internal structures of the system. Evidence has been found that the materials that are considered to be tacky in practice, display "delayed elastic effects" and require far larger impulses than nontacky materials. PMID:6726631
Single crystals of metal solid solutions
NASA Technical Reports Server (NTRS)
Miller, J. F.; Austin, A. E.; Richard, N.; Griesenauer, N. M.; Moak, D. P.; Mehrabian, M. R.; Gelles, S. H.
1974-01-01
The following definitions were sought in the research on single crystals of metal solid solutions: (1) the influence of convection and/or gravity present during crystallization on the substructure of a metal solid solution; (2) the influence of a magnetic field applied during crystallization on the substructure of a metal solid solution; and (3) requirements for a space flight experiment to verify the results. Growth conditions for the selected silver-zinc alloy system are described, along with pertinent technical and experimental details of the project.
Finite element solutions of free surface flows
NASA Technical Reports Server (NTRS)
Zarda, P. R.; Marcus, M. S.
1977-01-01
A procedure is presented for using NASTRAN to determine the flow field about arbitrarily shaped bodies in the presence of a free surface. The fundamental unknown of the problem is the velocity potential which must satisfy Laplace's equation in the fluid region. Boundary conditions on the free surface may involve second order derivatives in space and time. In cases involving infinite domains either a tractable radiation condition is applied at a truncated boundary or a series expansion is used and matched to the local finite elements. Solutions are presented for harmonic, transient, and steady state problems and compared to either exact solutions or other numerical solutions.
Radiolysis of aqueous solutions of thiamine
NASA Astrophysics Data System (ADS)
Chijate, C.; Albarran, G.; Negron-Mendoza, A.
1998-06-01
The results of the radiolysis of aqueous solutions of thiamine (vitamin B 1) are presented. The yields for decomposition of thiamine and the product of radiolytic products were determined. The G values decrease as the dose increases. Some radiolytic products were identified. Decomposition of thiamine was slightly dependent on the presence of oxygen and on the pH of the solution. At pH 4.4 with a concentration of 2.5 × 10 -4 mol L -1 of thiamine in an oxygen free aqueous solution, the G 0 value for decomposition is 5.0.
Modal series solution for an epidemic model
NASA Astrophysics Data System (ADS)
Acedo, L.; González-Parra, Gilberto; Arenas, Abraham J.
2010-03-01
In this article, we generalize a recently proposed method to obtain an exact general solution for the classical Susceptible, Infected, Recovered and Susceptible (SIRS) epidemic mathematical model. This generalization is based upon the nonlinear coupling of two frequencies in an infinite modal series solution. It is shown that these series provide a nonstandard approach in order to obtain an accurate analytical solution for the classical SIRS epidemic model. Numerical results of the SIRS epidemic model for real and complex frequencies are included in order to test the validity and reliability of the method. This method could be applied to a wide class of models in physics, chemistry or engineering.
Solutions of the coupled Higgs field equations.
Talukdar, Benoy; Ghosh, Swapan K; Saha, Aparna; Pal, Debabrata
2013-07-01
By an appropriate choice for the phase of the complex nucleonic field and going over to the traveling coordinate, we reduce the coupled Higgs equations to the Hamiltonian form and treat the resulting equation using the dynamical system theory. We present a phase-space analysis of its stable points. The results of our study demonstrate that the equation can support both traveling- and standing-wave solutions. The traveling-wave solution appears in the form of a soliton and resides in the midst of doubly periodic standing-wave solutions. PMID:23944601
Properties of lead-lithium solutions
Hoffman, N.J.; Darnell, A.; Blink, J.A.
1980-10-01
Lead-lithium solutions are of interest to liquid metal wall ICF reactor designers because Pb may be present to some extent in both heavy ion beam and laser-driven ICF targets; therefore, Pb will be present as an impurity in a flowing lithium wall. In addition, Pb-Li solutions containing approx. 80 a/o Pb are a strong candidate for a heavy ion beam driven HYLIFE converter and a viable alternative to a pure Li wall for a laser driven converter. The properties of Pb-Li solutions including the effect of hydrogen impurities are reviewed, and the reactor design implications are discussed.
Membrane separation of ionic liquid solutions
Campos, Daniel; Feiring, Andrew Edward; Majumdar, Sudipto; Nemser, Stuart
2015-09-01
A membrane separation process using a highly fluorinated polymer membrane that selectively permeates water of an aqueous ionic liquid solution to provide dry ionic liquid. Preferably the polymer is a polymer that includes polymerized perfluoro-2,2-dimethyl-1,3-dioxole (PDD). The process is also capable of removing small molecular compounds such as organic solvents that can be present in the solution. This membrane separation process is suitable for drying the aqueous ionic liquid byproduct from precipitating solutions of biomass dissolved in ionic liquid, and is thus instrumental to providing usable lignocellulosic products for energy consumption and other industrial uses in an environmentally benign manner.
Terahertz absorption of dilute aqueous solutions
NASA Astrophysics Data System (ADS)
Heyden, Matthias; Tobias, Douglas J.; Matyushov, Dmitry V.
2012-12-01
Absorption of terahertz (THz) radiation by aqueous solutions of large solutes reports on the polarization response of their hydration shells. This is because the dipolar relaxation of the solute is dynamically frozen at these frequencies, and most of the solute-induced absorption changes, apart from the expulsion of water, are caused by interfacial water. We propose a model expressing the dipolar response of solutions in terms of a single parameter, the interface dipole moment induced in the interfacial water by electromagnetic radiation. We apply this concept to experimental THz absorption of hydrated sugars, amino acids, and proteins. None of the solutes studied here follow the expectations of dielectric theories, which predict a negative projection of the interface dipole on the external electric field. We find that this prediction is not able to describe the available experimental data, which instead suggests a nearly zero interface dipole for sugars and a more diverse pattern for amino acids. Hydrophobic amino acids, similarly to sugars, give rise to near zero interface dipoles, while strongly hydrophilic ones are best described by a positive projection of the interface dipole on the external field. The sign of the interface dipole is connected to the slope of the absorption coefficient with the solute concentration. A positive slope, implying an increase in the solution polarity relative to water, mirrors results frequently reported for protein solutions. We therefore use molecular dynamics simulations of hydrated glucose and lambda repressor protein to calculate the interface dipole moments of these solutes and the concentration dependence of the THz absorption. The absorption at THz frequencies increases with increasing solute concentration in both cases, implying a higher polarity of the solution compared to bulk water. The structure of the hydration layer, extracted from simulations, is qualitatively similar in both cases, with spatial correlations
Analytical solutions of the Lorenz system
NASA Astrophysics Data System (ADS)
Kudryashov, Nikolay A.
2015-03-01
The Lorenz system is considered. The Painlevé test for the third-order equation corresponding to the Lorenz model at σ ≠ 0 is presented. The integrable cases of the Lorenz system and the first integrals for the Lorenz system are discussed. The main result of the work is the classification of the elliptic solutions expressed via the Weierstrass function. It is shown that most of the elliptic solutions are degenerated and expressed via the trigonometric functions. However, two solutions of the Lorenz system can be expressed via the elliptic functions.
Some More Solutions of Burgers' Equation
NASA Astrophysics Data System (ADS)
Kumar, Mukesh; Kumar, Raj
2015-01-01
In this work, similarity solutions of viscous one-dimensional Burgers' equation are attained by using Lie group theory. The symmetry generators are used for constructing Lie symmetries with commuting infinitesimal operators which lead the governing partial differential equation (PDE) to ordinary differential equation (ODE). Most of the constructed solutions are found in terms of Bessel functions which are new as far as authors are aware. Effect of various parameters in the evolutional profile of the solutions are shown graphically and discussed them physically.
Photoinduced spinodal decomposition in stratifying solutions
NASA Astrophysics Data System (ADS)
Bunkin, F. V.; Podgaetskii, V. I.; Semin, V. N.
1988-01-01
The effect of photoinduced spinodal decomposition in stratifying solutions is examined with particular reference to experimental results obtained for an aqueous solution of butyl Cellosolve of critical concentration (30.14 percent by mass). At the late stages of spinodal decomposition, the coalescence of similar microheterophase inhomogeneities leads to the formation of small-scale (up to 5 microns) grains of each of the phases, which are then grouped into larger-scale (up to 100 microns) segregations. Such multilevel self-organization of the stratifying phases leads to the formation of a granular-cellular structure. This effect can be used for the quick interruption of chemical reactions in a stratifying solution.
Stabilization of polyaniline solutions through additives
Wrobleski, D.A.; Benicewicz, B.C.
1996-12-10
A stabilized non-conductive polyaniline solution comprising from about 1 to about 10 percent by weight polyaniline or a polyaniline derivative, from about 90 to about 99 percent by weight N-methylpyrrolidone, and from about 0.5 percent by weight to about 15 percent by weight of a solution stabilizing additive selected from the group consisting of hindered amine light stabilizers, polymeric amines, and dialkylamines, percent by weight of additive based on the total weight of polyaniline or polyaniline derivative is provided together with a method for stabilizing a polyaniline solution. 4 figs.
NASA Astrophysics Data System (ADS)
Zhang, Zhizeng; Zhao, Zhao; Li, Yongtao
2016-06-01
This paper attempts to verify the correctness of the analytical displacement solution in transversely isotropic rock mass, and to determine the scope of its application. The analytical displacement solution of a circular tunnel in transversely isotropic rock mass was derived firstly. The analytical solution was compared with the numerical solution, which was carried out by FLAC3D software. The results show that the expression of the analytical displacement solution is correct, and the allowable engineering range is that the dip angle is less than 15 degrees.
Sun, Xiang; Ladanyi, Branka M; Stratt, Richard M
2015-07-23
Experimental studies of solvation dynamics in liquids invariably ask how changing a solute from its electronic ground state to an electronically excited state affects a solution's dynamics. With traditional time-dependent-fluorescence experiments, that means looking for the dynamical consequences of the concomitant change in solute-solvent potential energy. But if one follows the shift in the dynamics through its effects on the macroscopic polarizability, as recent solute-pump/solvent-probe spectra do, there is another effect of the electronic excitation that should be considered: the jump in the solute's own polarizability. We examine the spectroscopic consequences of this solute polarizability change in the classic example of the solvation dye coumarin 153 dissolved in acetonitrile. After demonstrating that standard quantum chemical methods can be used to construct accurate multisite models for the polarizabilities of ground- and excited-state solvation dyes, we show via simulation that this polarizability change acts as a contrast agent, significantly enhancing the observable differences in optical-Kerr spectra between ground- and excited-state solutions. A comparison of our results with experimental solute-pump/solvent-probe spectra supports our interpretation and modeling of this spectroscopy. We predict, in particular, that solute-pump/solvent-probe spectra should be sensitive to changes in both the solvent dynamics near the solute and the electronic-state-dependence of the solute's own rotational dynamics. PMID:25299940
NASA Astrophysics Data System (ADS)
Wynveen, Aaron; Bresme, Fernando
2010-10-01
We investigate the distributions of various salts about large hydrophobic polarizable solutes in aqueous electrolyte solutions. The solutes are modeled as nanometer-sized cylindrical objects, a scale relevant to biomolecules and nanomaterials, and particularly high aspect ratio nanoparticles. Interactions, including image charge forces arising from the finite polarizability of the solute, between explicit solvent/ions and the solute are computed explicitly using a molecular dynamics simulation methodology we have recently introduced. Comparisons are made between several salt species and different models of the force fields for each ionic component of the salt. We find evidence that both small cations, Li+, and large anions, I-, adsorb at hydrophobic interfaces. Our results indicate that the ion structure about the solute is strongly dependent on the force field investigated, suggesting that ion selectivity is quite sensitive to the respective parameters defining the ion's size and binding energy as well as to the polarizability of the solute.
NASA Astrophysics Data System (ADS)
Lavoie, Andre
L'objectif principal que que nous poursuivons est de developper un modele de simulation du transfert radiatif eau-atmosphere adapte aux observations faites par le capteur Thematic Mapper (TM) de Landsat. Les informations que nous cherchons ont trait au milieu cotier marin et concernent les elements qui sont en suspension dans l'eau. Les images multibandes du capteur TM dans la partie visible du spectre, sont surtout visees par nos travaux. A la base de la simulation, nous utilisons un programme de simulation atmospherique, le code 6S, auquel nous greffons un modele de simulation du transfert radiatif dans la masse d'eau. Ce dernier estime le signal en fonction de 4 composants: l'eau, les pigments chlorophylliens (chlorophylle et phaeopigments), les matieres minerales et les substances organiques dissoutes. La concentration des differents composants sert de parametre d'entree pour definir le comportement optique de la masse d'eau. Le modele permet egalement de simuler une masse d'eau stratifiee si l'on connai t les concentrations des composants dans les differentes couches. Il inclut aussi la contribution du fond, selon sa nature et sa composition, ainsi que celle du miroitement du soleil et du ciel a la surface de l'eau. Les informations d'un echantillonnage de la masse d' eau synchronise avec le passage du satellite, a la baie des Chaleurs, d'une cartographie du couvert d'algues et d'un modele bathymetrique ont ete utilisees pour fixer les parametres de simulation par le modele. La comparaison montrent que le modele se comporte relativement bien surtout dans la bande TM2. Une erreur systematique de 2 valeurs numeriques en moyenne subsiste dans les trois bandes spectrales. Les resultats nous montrent que la visibilite du fond aux faibles profondeurs est un element tres important a considerer. Par ailleurs, l'analyse de sensibilite montre que les images TM sont plus sensibles aux concentrations en matieres minerales qu'aux pigments chlorophylliens et aux substances
Knee System Utilizing Personalized Solutions Instrumentation
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Non-ideal solution thermodynamics of cytoplasm.
Ross-Rodriguez, Lisa U; Elliott, Janet A W; McGann, Locksley E
2012-10-01
Quantitative description of the non-ideal solution thermodynamics of the cytoplasm of a living mammalian cell is critically necessary in mathematical modeling of cryobiology and desiccation and other fields where the passive osmotic response of a cell plays a role. In the solution thermodynamics osmotic virial equation, the quadratic correction to the linear ideal, dilute solution theory is described by the second osmotic virial coefficient. Herein we report, for the first time, intracellular solution second osmotic virial coefficients for four cell types [TF-1 hematopoietic stem cells, human umbilical vein endothelial cells (HUVEC), porcine hepatocytes, and porcine chondrocytes] and further report second osmotic virial coefficients indistinguishable from zero (for the concentration range studied) for human hepatocytes and mouse oocytes. PMID:23840923
Inhomogeneous mixmaster universes: Some exact solutions
Carmeli, M.; Charach, C.; Feinstein, A.
1983-10-15
Algorithms for generating new exact solutions of the Einstein-Klein-Gordon field equations, which describe inhomogeneous universes with S/sup 3/ topology of spatial sections, are developed. The known exact vacuum and still-fluid solutions with S/sup 3/ topology are used as an input. The methods developed are further applied to derive inhomogeneous generalizations of Bianchi type IX solutions and inhomogeneous S/sup 3/ Gowdy models with gravitational and scalar waves. It is shown that the new solutions, which are generalizations of the Bianchi type IX models, permit identification of the scalar field with the velocity potential of the stiff irrotational fluid. The latter result is further used to study the growth rate of density perturbations of the isotropic and anisotropic Bianchi type IX universes in a fully nonlinear relativistic regime. The role of anisotropy on the rate of growth of density perturbations is studied in detail.
A Solution Framework for Environmental Characterization Problems
This paper describes experiences developing a grid-enabled framework for solving environmental inverse problems. The solution approach taken here couples environmental simulation models with global search methods and requires readily available computational resources of the grid ...
Crafting Elegant Solutions: Strategies for Conflict Resolution.
ERIC Educational Resources Information Center
Koch, Susan J.; Decker, Robert H.
1993-01-01
The conflict-resolution technique of interpersonal negotiation involves five steps: (1) state your positive intentions; (2) define, analyze, and discuss the problem; (3) summarize progress; (4) explore alternative solutions; and (5) set a time for follow-up. (MLF)
Tannin (Polyphenol) Stability in Aqueous Solutions
Technology Transfer Automated Retrieval System (TEKTRAN)
Understanding the chemical stability of tannins (polyphenolics) in soils is critical to understanding their biological activities and fate. We examined the stability of chemically defined tannins in aqueous solutions under conditions simulating natural and laboratory conditions. We evaluated tanni...
Coordination chemistry in fused-salt solutions
NASA Technical Reports Server (NTRS)
Gruen, D. M.
1969-01-01
Spectrophotometric work on structural determinations with fused-salt solutions is reviewed. Constraints placed on the method, as well as interpretation of the spectra, are discussed with parallels drawn to aqueous spectrophotometric curves of the same materials.
Aggregation of sodium alkylbenzenesulfonates in aqueous solution
Magid, L.J.; Shaver, R.J.; Gulari, E.; Bedwell, B.; Alkhafaji, S.
1981-01-01
The surfactant 6 phenyl C/sub 12/SNa forms small spherical micelles in aqueous solution, having an aggregation number of 20 to 30 and a fractional charge of 0.45. These micelles are hydrated to the extent of approximately 18 moles H/sub 2/O per moles of surfactant. A second larger aggregate is also present in 6 phenyl C/sub 12/SNa solutions; its importance increases with solution age. Addition of NaCl causes both aggregates to apparently increase modestly in size. The surfactant 8 phenyl C/sub 16/SNa also contains both aggregates in its solutions; the larger one is relatively more important here. The larger aggregate does not correspond to dispersed bits of a liquid crystalline mesophase.
Lightweight Steel Solutions for Automotive Industry
Lee, Hong Woo; Kim, Gyosung; Park, Sung Ho
2010-06-15
Recently, improvement in fuel efficiency and safety has become the biggest issue in worldwide automotive industry. Although the regulation of environment and safety has been tightened up more and more, the majority of vehicle bodies are still manufactured from stamped steel components. This means that the optimized steel solutions enable to demonstrate its ability to reduce body weight with high crashworthiness performance instead of expensive light weight materials such as Al, Mg and composites. To provide the innovative steel solutions for automotive industry, POSCO has developed AHSS and its application technologies, which is directly connected to EVI activities. EVI is a technical cooperation program with customer covering all stages of new car project from design to mass production. Integrated light weight solutions through new forming technologies such as TWB, hydroforming and HPF are continuously developed and provided for EVI activities. This paper will discuss the detailed status of these technologies especially light weight steel solutions based on innovative technologies.
Relational Conceptual Change in Solution Chemistry.
ERIC Educational Resources Information Center
Ebenezer, Jazlin V.; Gaskell, P. James
1995-01-01
Explores changes in students' conceptions about solution chemistry in the context of instruction based on collaboration between a researcher and an experienced teacher attempting to implement strategies from the literature on conceptual change. (ZWH)
Technology Solutions for School Food Service.
ERIC Educational Resources Information Center
Begalle, Mary
2002-01-01
Considers ways to include schools' food service departments in technology planning. Discusses school food service software applications, considerations and challenges of automating food service operations, and business-to-business Internet solutions. (EV)
Removal of metal ions from aqueous solution
Jackson, P.J.; Delhaize, E.; Robinson, N.J.; Unkefer, C.J.; Furlong, C.
1990-03-20
This patent describes a method of removing heavy metals from aqueous solution, a composition of matter used in effecting the removal, and apparatus used in effecting the removal. One or more of the polypeptides, poly ({gamma}-glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly ({gamma}-glutamylcysteinyl)glycines having a particular number of monomer repeat units for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heavy metals from solution. This also results in the removal of the metals from the column in a concentrated form.
Removal of metal ions from aqueous solution
Jackson, Paul J.; Delhaize, Emmanuel; Robinson, Nigel J.; Unkefer, Clifford J.; Furlong, Clement
1990-01-01
A method of removing heavy metals from aqueous solution, a composition of matter used in effecting said removal, and apparatus used in effecting said removal. One or more of the polypeptides, poly (.gamma.-glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly (.gamma.-glutamylcysteinyl)glycines having a particular number of monomer repeat units for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heavy metals from solution. This also results in the removal of the metals from the column in a concentrated form.
Removal of metal ions from aqueous solution
Jackson, P.J.; Delhaize, E.; Robinson, N.J.; Unkefer, C.J.; Furlong, C.
1988-08-26
A method of removing heavy metals from aqueous solution, a composition of matter used in effecting said removal, and apparatus used in effecting said removal. One or more of the polypeptides, poly ({gamma}-glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly ({gamma}-glutamylcysteinyl)glycines having a particular number of monomer repeat units for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heavy metals from solution. This also results in the removal of the metals from the column in a concentrated form.
Removal of metal ions from aqueous solution
Jackson, P.J.; Delhaize, E.; Robinson, N.J.; Unkefer, C.J.; Furlong, C.
1990-11-13
A method is disclosed of removing heavy metals from aqueous solution, a composition of matter used in effecting said removal, and apparatus used in effecting said removal. One or more of the polypeptides, poly ([gamma]glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly ([gamma]glutamylcysteinyl)glycines having a particular number of monomer repeat unit for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heavy metals from solution. This also results in the removal of the metals from the column in a concentrated form. 1 fig.
Removal of metal ions from aqueous solution
Jackson, Paul J.; Delhaize, Emmanuel; Robinson, Nigel J.; Unkefer, Clifford J.; Furlong, Clement
1990-11-13
A method of removing heavy metals from aqueous solution, a composition of matter used in effecting said removal, and apparatus used in effecting said removal. One or more of the polypeptides, poly (.gamma.-glutamylcysteinyl)glycines, is immobilized on an inert material in particulate form. Upon contact with an aqueous solution containing heavy metals, the polypeptides sequester the metals, removing them from the solution. There is selectivity of poly (.gamma.-glutamylcysteinyl)glycines having a particular number of monomer repeat unit for particular metals. The polypeptides are easily regenerated by contact with a small amount of an organic acid, so that they can be used again to remove heayv metals from solution. This also results in the removal of the metals from the column in a concentrated form.
Ensuring Safe Use of Contact Lens Solution
... For Consumers Consumer Updates Ensuring Safe Use of Contact Lens Solution Share Tweet Linkedin Pin it More ... back to top Dos and Don'ts for Contact Lens Wearers DO: Always wash your hands before ...
Metal Surface Decontamination by the PFC Solution
Hui-Jun Won; Gye-Nam Kim; Wang-Kyu Choi; Chong-Hun Jung; Won-Zin Oh
2006-07-01
PFC (per-fluorocarbon) spray decontamination equipment was fabricated and its decontamination behavior was investigated. Europium oxide powder was mixed with the isotope solution which contains Co-60 and Cs-137. The different shape of metal specimens artificially contaminated with europium oxide powder was used as the surrogate contaminants. Before and after the application of the PFC spray decontamination method, the radioactivity of the metal specimens was measured by MCA. The decontamination factors were in the range from 9.6 to 62.4. The spent PFC solution was recycled by distillation. Before and after distillation, the turbidity of PFC solution was also measured. From the test results, it was found that more than 98% of the PFC solution could be recycled by a distillation. (authors)
Missing solution in a Cornell potential
NASA Astrophysics Data System (ADS)
Castro, L. B.; de Castro, A. S.
2013-11-01
Missing bound-state solutions for fermions in the background of a Cornell potential consisting of a mixed scalar-vector-pseudoscalar coupling is examined. Charge-conjugation operation, degeneracy and localization are discussed.
Lightweight Steel Solutions for Automotive Industry
NASA Astrophysics Data System (ADS)
Lee, Hong Woo; Kim, Gyosung; Park, Sung Ho
2010-06-01
Recently, improvement in fuel efficiency and safety has become the biggest issue in worldwide automotive industry. Although the regulation of environment and safety has been tightened up more and more, the majority of vehicle bodies are still manufactured from stamped steel components. This means that the optimized steel solutions enable to demonstrate its ability to reduce body weight with high crashworthiness performance instead of expensive light weight materials such as Al, Mg and composites. To provide the innovative steel solutions for automotive industry, POSCO has developed AHSS and its application technologies, which is directly connected to EVI activities. EVI is a technical cooperation program with customer covering all stages of new car project from design to mass production. Integrated light weight solutions through new forming technologies such as TWB, hydroforming and HPF are continuously developed and provided for EVI activities. This paper will discuss the detailed status of these technologies especially light weight steel solutions based on innovative technologies.
Concentration of perrhenate and pertechnetate solutions
Knapp, F.F.; Beets, A.L.; Mirzadeh, S.; Guhlke, S.
1998-03-17
A method is described for preparing a concentrated solution of a carrier-free radioisotope which includes the steps of: (a) providing a generator column loaded with a composition containing a parent radioisotope; (b) eluting the generator column with an eluent solution which includes a salt of a weak acid to elute a target daughter radioisotope from the generator column in a first eluate; (c) eluting a cation-exchange column with the first eluate to exchange cations of the salt for hydrogen ions and to elute the target daughter radioisotope and a weak acid in a second eluate; (d) eluting an anion-exchange column with the second eluate to trap and concentrate the target daughter radioisotope and to elute the weak acid solution therefrom; and (e) eluting the concentrated target daughter radioisotope from the anion-exchange column with a saline solution. 1 fig.
Concentration of perrhenate and pertechnetate solutions
Knapp, Furn F.; Beets, Arnold L.; Mirzadeh, Saed; Guhlke, Stefan
1998-01-01
A method of preparing a concentrated solution of a carrier-free radioisotope which includes the steps of: a. providing a generator column loaded with a composition containing a parent radioisotope; b. eluting the generator column with an eluent solution which includes a salt of a weak acid to elute a target daughter radioisotope from the generator column in a first eluate. c. eluting a cation-exchange column with the first eluate to exchange cations of the salt for hydrogen ions and to elute the target daughter radioisotope and a weak acid in a second eluate; d. eluting an anion-exchange column with the second eluate to trap and concentrate the target daughter radioisotope and to elute the weak acid solution therefrom; and e. eluting the concentrated target daughter radioisotope from the anion-exchange column with a saline solution.
Solution to the quantum Zermelo navigation problem.
Brody, Dorje C; Meier, David M
2015-03-13
The solution to the problem of finding a time-optimal control Hamiltonian to generate a given unitary gate, in an environment in which there exists an uncontrollable ambient Hamiltonian (e.g., a background field), is obtained. In the classical context, finding the time-optimal way to steer a ship in the presence of a background wind or current is known as the Zermelo navigation problem, whose solution can be obtained by working out geodesic curves on a space equipped with a Randers metric. The solution to the quantum Zermelo problem, which is shown here to take a remarkably simple form, is likewise obtained by finding explicit solutions to the geodesic equations of motion associated with a Randers metric on the space of unitary operators. The result reveals that the optimal control in a sense "goes along with the wind." PMID:25815915
[Photochemical degradation of chlorothalonil in aqueous solution].
Li, Xuede; Hua, Rimao; Yue, Yongde; Li, Ying; Tang, Feng; Tang, Jun
2006-06-01
The study on the effects of light source, solution pH and temperature, and surfactant on the photochemical degradation of chlorothalonil showed that the half-life of chlorothalonil photodegradation under high pressure mercury lamp (HPML), UV lamp and sunlight was 22.4, 82.5 and 123.8 min, respectively. Under HPML and sunlight, chlorothalonil had a higher photolysis rate in alkaline solution than in neutral and acid solution. The photolysis rate increased with increasing solution temperature in the range of 10 degrees C - 40 degrees C, which was doubled when the temperature increased every 10 degrees C. Sodium laurylsulfonate (SDS), sodium dodecylbenzene sulfonate (SDBS), Tween 60 and Span 20 showed significant photosensitizing effects, while cetyltrimethylammonium bromide (CTAB) had significant photoquench effect on the photolysis of chlorothalonil. PMID:16964947
Pinching solutions of slender cylindrical jets
NASA Technical Reports Server (NTRS)
Papageorgiou, Demetrios T.; Orellana, Oscar
1993-01-01
Simplified equations for slender jets are derived for a circular jet of one fluid flowing into an ambient second fluid, the flow being confined in a circular tank. Inviscid flows are studied which include both surface tension effects and Kelvin-Helmholtz instability. For slender jets a coupled nonlinear system of equations is found for the jet shape and the axial velocity jump across it. The equations can break down after a finite time and similarity solutions are constructed, and studied analytically and numerically. The break-ups found pertain to the jet pinching after a finite time, without violation of the slender jet ansatz. The system is conservative and admissible singular solutions are those which conserve the total energy, mass, and momentum. Such solutions are constructed analytically and numerically, and in the case of vortex sheets with no surface tension certain solutions are given in closed form.
RECOVERY OF CESIUM FROM WASTE SOLUTIONS
Burgus, W.H.
1959-06-30
This patent covers the precipitation of fission products including cesium on nickel or ferric ferrocyanide and subsequent selective dissolution from the carrier with a solution of ammonia or mercurlc nitrate.
Application of thermodynamics to silicate crystalline solutions
NASA Technical Reports Server (NTRS)
Saxena, S. K.
1972-01-01
A review of thermodynamic relations is presented, describing Guggenheim's regular solution models, the simple mixture, the zeroth approximation, and the quasi-chemical model. The possibilities of retrieving useful thermodynamic quantities from phase equilibrium studies are discussed. Such quantities include the activity-composition relations and the free energy of mixing in crystalline solutions. Theory and results of the study of partitioning of elements in coexisting minerals are briefly reviewed. A thermodynamic study of the intercrystalline and intracrystalline ion exchange relations gives useful information on the thermodynamic behavior of the crystalline solutions involved. Such information is necessary for the solution of most petrogenic problems and for geothermometry. Thermodynamic quantities for tungstates (CaWO4-SrWO4) are calculated.
Tail mean and related robust solution concepts
NASA Astrophysics Data System (ADS)
Ogryczak, Włodzimierz
2014-01-01
Robust optimisation might be viewed as a multicriteria optimisation problem where objectives correspond to the scenarios although their probabilities are unknown or imprecise. The simplest robust solution concept represents a conservative approach focused on the worst-case scenario results optimisation. A softer concept allows one to optimise the tail mean thus combining performances under multiple worst scenarios. We show that while considering robust models allowing the probabilities to vary only within given intervals, the tail mean represents the robust solution for only upper bounded probabilities. For any arbitrary intervals of probabilities the corresponding robust solution may be expressed by the optimisation of appropriately combined mean and tail mean criteria thus remaining easily implementable with auxiliary linear inequalities. Moreover, we use the tail mean concept to develope linear programming implementable robust solution concepts related to risk averse optimisation criteria.
Preparation of (228)Ra standard solution.
Havelka, Miroslav
2016-03-01
For the preparation of a standard solution of (228)Ra, (228)Ra was isolated from (232)Th salt. Two simple methods were developed for Th-Ra separation. Both are based on a very good solubility of thorium nitrate in organic solvents. The first one used Ra co-precipitation with Pb in the form of Pb(NO3)2 from acetic acid solution. The second method was based on solvent extraction, remaining Th in the organic phase, while Ra was concentrated in the aqueous phase. The activity of (228)Ra (up to 20kBq) in the standard solution was related to the (232)Th standard by means of gamma ray spectrometry measurement. The obtained uncertainty was less than 0.7% (k=1). The standard solution was free of (232)Th and contained the carrier in the usual concentration (1gL(-1) BaCl2, 10gL(-1) HCl). PMID:26651171
Restorative Justice and the Prosocial Communities Solution.
ERIC Educational Resources Information Center
Blechman, Elaine A.; Hile, Matthew G.; Fishman, Daniel B.
2001-01-01
Restorative justice promotes greater accountability, competency, and public safety through community care of juvenile offenders. The Prosocial Communities Solution builds an infrastructure around information sharing, coordinated supervision, and immersion in prosocial activities. Communities horizontally align parents with professional caregivers…
Pressure Solution at the Molecular Scale
NASA Astrophysics Data System (ADS)
Pachon-Rodriguez, Edgar Alejandro; Piednoir, Agnès; Colombani, Jean
2011-09-01
The topological evolution of the cleavage surface of a gypsum single crystal during its dissolution in a flowing undersaturated aqueous solution has been observed with an atomic force microscope. The matter transfer from solid to liquid proceeds through the migration of atomic steps. The step velocity has been measured and appears to depend on the force applied by the tip on the surface. Whereas the high force velocity enhancement is likely to stem from corrosive wear, the speed behavior at low force (<10nN) differs drastically and can be interpreted as a consequence of the pressure solution of the crystal induced by the tip force. The step velocity evolution with the force obeys the known kinetic law of pressure solution. Hence these experiments enable us to evidence a first atomic mechanism at the origin of pressure solution.
Pressure solution at the molecular scale.
Pachon-Rodriguez, Edgar Alejandro; Piednoir, Agnès; Colombani, Jean
2011-09-30
The topological evolution of the cleavage surface of a gypsum single crystal during its dissolution in a flowing undersaturated aqueous solution has been observed with an atomic force microscope. The matter transfer from solid to liquid proceeds through the migration of atomic steps. The step velocity has been measured and appears to depend on the force applied by the tip on the surface. Whereas the high force velocity enhancement is likely to stem from corrosive wear, the speed behavior at low force (<10 nN) differs drastically and can be interpreted as a consequence of the pressure solution of the crystal induced by the tip force. The step velocity evolution with the force obeys the known kinetic law of pressure solution. Hence these experiments enable us to evidence a first atomic mechanism at the origin of pressure solution. PMID:22107215
Thermodynamics of solutions containing hyperbranched polymers
Mio, C.; Lue, L.; Prausnitz, J.
1996-12-31
Vapor-liquid equilibria (VLE) have been obtained for solutions of hyperbranched polymers in chloroform, acetone, cyclohexane, methanol, acetonitrile or n-propylamine in the range 35 to 80{degrees}C. Polymers with different branched structures were studied: star, comb and dendritic polymers. Data interpretation is based on the lattice cluster theory (LCT) of Freed and coworkers. Unlike the Flory-Huggins theory, LCT can predict the effect of molecular architecture on thermodynamic solution properties.
Quantum corrections for a cosmological string solution
Behrndt, K.
1994-08-01
The author investigates quantum corrections for a cosmological solution of the string effective action. Starting point is a classical solution containing an antisymmetric tensor field, a dilaton and a modulus field which has singularities in the scalar fields. As a first step he quantizes the scalar fields near the singularity with the result that the singularities disappear and that in general non-perturbative quantum corrections form a potential in the scalar fields.
Nitric acid recovery from waste solutions
Wilson, A. S.
1959-04-14
The recovery of nitric acid from aqueous nitrate solutions containing fission products as impurities is described. It is desirable to subject such solutions to concentration by evaporation since nitric acid is regenerated thereby. A difficulty, however, is that the highly radioactive fission product ruthenium is volatilized together with the nitric acid. It has been found that by adding nitrous acid, ruthenium volatilization is suppressed and reduced to a negligible degree so that the distillate obtained is practically free of ruthenium.
Electrochemical Assay of Gold-Plating Solutions
NASA Technical Reports Server (NTRS)
Chiodo, R.
1982-01-01
Gold content of plating solution is assayed by simple method that required only ordinary electrochemical laboratory equipment and materials. Technique involves electrodeposition of gold from solution onto electrode, the weight gain of which is measured. Suitable fast assay methods are economically and practically necessary in electronics and decorative-plating industries. If gold content in plating bath is too low, poor plating may result, with consequent economic loss to user.
Similarity solutions for phase-change problems
NASA Technical Reports Server (NTRS)
Canright, D.; Davis, S. H.
1989-01-01
A modification of Ivantsov's (1947) similarity solutions is proposed which can describe phase-change processes which are limited by diffusion. The method has application to systems that have n-components and possess cross-diffusion and Soret and Dufour effects, along with convection driven by density discontinuities at the two-phase interface. Local thermal equilibrium is assumed at the interface. It is shown that analytic solutions are possible when the material properties are constant.
General solution of the cyclic Leibniz rule
NASA Astrophysics Data System (ADS)
Kadoh, Daisuke; Ukita, Naoya
2015-10-01
We study the cyclic Leibniz rule (CLR) which was recently proposed as a new approach to the realization of supersymmetric quantum mechanics on the lattice. The CLR has an infinite number of solutions that give the different definitions of the lattice supersymmetric quantum mechanics. We show the general form of the solution for the naive symmetric difference operator and reveal the differences between the lattice models.
Towards combined global monthly gravity field solutions
NASA Astrophysics Data System (ADS)
Jaeggi, Adrian; Meyer, Ulrich; Beutler, Gerhard; Weigelt, Matthias; van Dam, Tonie; Mayer-Gürr, Torsten; Flury, Jakob; Flechtner, Frank; Dahle, Christoph; Lemoine, Jean-Michel; Bruinsma, Sean
2014-05-01
Currently, official GRACE Science Data System (SDS) monthly gravity field solutions are generated independently by the Centre for Space Research (CSR) and the German Research Centre for Geosciences (GFZ). Additional GRACE SDS monthly fields are provided by the Jet Propulsion Laboratory (JPL) for validation and outside the SDS by a number of other institutions worldwide. Although the adopted background models and processing standards have been harmonized more and more by the various processing centers during the past years, notable differences still exist and the users are more or less left alone with a decision which model to choose for their individual applications. This procedure seriously limits the accessibility of these valuable data. Combinations are well established in the area of other space geodetic techniques, such as the Global Navigation Satellite Systems (GNSS), Satellite Laser Ranging (SLR), and Very Long Baseline Interferometry (VLBI). Regularly comparing and combining space-geodetic products has tremendously increased the usefulness of the products in a wide range of disciplines and scientific applications. Therefore, we propose in a first step to mutually compare the large variety of available monthly GRACE gravity field solutions, e.g., by assessing the signal content over selected regions, by estimating the noise over the oceans, and by performing significance tests. We make the attempt to assign different solution characteristics to different processing strategies in order to identify subsets of solutions, which are based on similar processing strategies. Using these subsets we will in a second step explore ways to generate combined solutions, e.g., based on a weighted average of the individual solutions using empirical weights derived from pair-wise comparisons. We will also assess the quality of such a combined solution and discuss the potential benefits for the GRACE and GRACE-FO user community, but also address minimum processing
Theoretical study of chemical reactions in solution
Yokogawa, D.
2015-12-31
Quantum chemical calculations in solution are becoming more and more important in chemistry. Reference interaction site model self-consistent field (RISM-SCF) is one of the powerful approaches to perform quantum chemical calculations in solution. In this work, we developed a new generation of RISM-SCF, where a robust fitting method was newly introduced. We applied the new method to tautomerization reaction of cytosine in aqueous phase. Our calculation reproduced experimentally obtained relative stabilities and relative free energies correctly.
"Permanence" - An Adaptationist Solution to Fermi's Paradox?
NASA Astrophysics Data System (ADS)
Cirkovic, Milan M.
A new solution of Fermi's paradox sketched by SF writer Karl Schroeder in his 2002. novel Permanence is investigated. It is argued that this solution is tightly connected with adaptationism - a widely discussed working hypothesis in evolutionary biology. Schroeder's hypothesis has important ramifications for astrobiology, SETI projects, and future studies. Its weaknesses should be explored without succumbing to the emotional reactions often accompanying adaptationist explanations.
Solution dewatering with concomitant ion removal
Peterson, Eric S.; Marshall, Douglas W.; Stone, Mark L.
2003-08-05
One of the biggest needs in the separations and waste handling and reduction area is a method for dewatering ion-containing solutions. Unexpectedly, it has been found that phosphazene polymers can discriminate between water and metal ions, allowing water to pass through the membrane while retaining the ions. This unexpected result, along with the inherent chemical and thermal stability of the phosphazene polymers, yields a powerful tool for separating and dewatering metal-ion-containing solutions.
Approximate Solutions Of Equations Of Steady Diffusion
NASA Technical Reports Server (NTRS)
Edmonds, Larry D.
1992-01-01
Rigorous analysis yields reliable criteria for "best-fit" functions. Improved "curve-fitting" method yields approximate solutions to differential equations of steady-state diffusion. Method applies to problems in which rates of diffusion depend linearly or nonlinearly on concentrations of diffusants, approximate solutions analytic or numerical, and boundary conditions of Dirichlet type, of Neumann type, or mixture of both types. Applied to equations for diffusion of charge carriers in semiconductors in which mobilities and lifetimes of charge carriers depend on concentrations.
Relational conceptual change in solution chemistry
NASA Astrophysics Data System (ADS)
Ebenezer, Jazlin V.; Gaskell, P. James
This study explores changes to students' conceptions about solution chemistry in the context of instruction based on collaboration between a researcher and an experienced teacher attempting to implement strategies from the literature on conceptual change. Conceptual change for students and teachers is viewed not just as a process of replacement of old concepts but also as a process of learning to relate ideas to appropriate contexts. The process of instruction and collaboration was influenced by institutional limits on time, the press to cover the curriculum, and the teacher's prior beliefs and practices. The study uses phenomenography to conceptualize students' understandings of solubility. Six categories of description were constructed: (a) physical transformation from solid to liquid; (b) chemical transformation of solute; (c) density of solute; (d) amount of space available in solution; (e) properties of solute; and (f) size of solute. After instruction students showed evidence of two additional ways of talking about solubility: (a) chemical structure of components; and (b) solution equilibrium. The new language, however, did not necessarily replace initial ideas about what happens in particular instances of solution chemistry. A careful analysis of the students' conceptions of solubility revealed important factors influencing the nature of student learning in this area of chemistry. These factors include: (a) ambiguities of chemical theories about dissolving: (b) explanations of the observable; and (c) students' chemical language. It is argued, in conclusion, that the goals for instruction are to assist students to appreciate contexts where everyday conceptions of chemical phenomenon are appropriate and contexts where particular conceptions from the community of chemists are more appropriate.
Atomistically informed solute drag in Al Mg
NASA Astrophysics Data System (ADS)
Zhang, F.; Curtin, W. A.
2008-07-01
Solute drag in solute-strengthened alloys, caused by diffusion of solute atoms around moving dislocations, controls the stress at deformation rates and temperatures useful for plastic forming processes. In the technologically important Al-Mg alloys, the solute drag stresses predicted by classical theories are much larger than experiments, which is resolved in general by eliminating the singularity of the dislocation core via Peierls-Nabarro-type models. Here, the drag stress versus dislocation velocity is computed numerically using a realistic dislocation core structure obtained from an atomistic model to investigate the role of the core and obtain quantitative stresses for comparison with experiment. The model solves a discrete diffusion equation in a reference frame moving with the dislocation, with input solute enthalpies and diffusion activation barriers in the core computed by or estimated from atomistic studies. At low dislocation velocities, the solute drag stress is controlled by bulk solute diffusion because the core diffusion occurs too quickly. In this regime, the drag stress can be obtained using a Peierls-Nabarro model with a core spreading parameter tuned to best match the atomistic models. At intermediate velocities, both bulk and core diffusion can contribute to the drag, leading to a complex stress-velocity relationship showing two peaks in stress. At high velocities, the drag stress is controlled solely by diffusion within and across the core. Like the continuum models, the drag stress is nearly linear in solute concentration. The Orowan relationship is used to connect dislocation velocity to deformation strain rate. Accounting for the dependence of mobile dislocation density on stress, the simulations are in good agreement with experiments on Al-Mg alloys over a range of concentrations and temperatures.
Spherically symmetric solutions in a FRW background
NASA Astrophysics Data System (ADS)
Moradpour, H.; Riazi, N.
2015-02-01
We impose perfect fluid concept along with slow expansion approximation to derive new solutions which, considering non-static spherically symmetric metrics, can be treated as Black Holes (BHs). We will refer to these solutions as Quasi BHs. Mathematical and physical features such as Killing vectors, singularities, and mass have been studied. Their horizons and thermodynamic properties have also been investigated. In addition, relationship with other related works (including McVittie's) are described.
Chemical-milling solution for invar alloy
NASA Technical Reports Server (NTRS)
Batiuk, W.
1980-01-01
Excellent surface finishes and tolerances are achieved using two formulations. Solution A gives finish of 3.17 micrometers after milling at 57 to 63 deg C. Constituents of A are: Hydrofluoric acid (70%), 5,8 oz/gal; nitric acid (40-42) degrees Baume), 40 oz/gal. Alternative solution gives 2.16 micrometer finish, and differs from A by addition of 7% phosphoric acid. Formulations eliminate channeling at root fillets, dishing, island formation, and overhangs.
SEPARATION OF SCANDIUM FROM AQUEOUS SOLUTIONS
Peppard, D.F.; Nachtman, E.S.
1958-02-25
This patent relates to a process for the separation of scandium from yttrium, thorium, and trivalent rare earths and with their separation from each other. It has been found that scandium and yttrium can be separated from trivalent rare earths in acidic solution, for example, a solution 6 M in HCl, by contacting with tributyl phosphate, whereupon the scandum is preferentially extracted into the organic phase, leaving the yttrium and trivalent rare earths in the aqueous phase.
Heat capacity of alkanolamine aqueous solutions
Chiu, L.F.; Li, M.H.
1999-12-01
Heat capacities of monoethanoloamine, diglycolamine, diethanolamine, di-w propanolamine, triethanolamine, N-methyldiethanolamine, 2-amino-2-methyl-l-propanol, and 2-piperidineethanol aqueous solutions were measured from 30 to 80 C with a differential scanning calorimeter (DSC). The mole fractions of alkanolamines studied are 0.2, 0.4, 0.6, and 0.8. Heat capacities of N-methyldiethanolamine aqueous solutions have been measured to verify the validity of C{sub p} measurements for alkanolamine aqueous solutions. The estimated uncertainty of the measured heat capacities is {plus{underscore}minus}3%, including the effect of up to 5% impurities in a substance. An excess molar heat capacity expression using the Redlich-Kister equation for the composition dependence is used to represent the measured C{sub p} of alkanolamine aqueous solutions. For a total of 374 data points, the calculation results for eight alkanolamine solutions give the overall average absolute deviations of 11.9% and 0.29% for the excess molar heat capacity and the heat capacity, respectively. The heat capacities presented in this study are, in general, of sufficient accuracy for most engineering-design calculations. Solutions of alkanolamines are industrially important mixtures used in the natural gas industry, oil refineries, petroleum chemical plants, and synthetic ammonia plants for the removal of acidic components such as CO{sub 2} and H{sub 2}S from gas streams.
Solubility of uranium in alkaline salt solutions
Hobbs, D.T.; Edwards, T.B.
1994-03-29
The solubility of uranium in alkaline salt solutions was investigated to screen for significant factors and interactions among the major salt components and temperature. The components included in the study were the sodium salts of hydroxide, nitrate, nitrite, aluminate, sulfate, and carbonate. General findings from the study included: (1) uranium solubilities are very low (1-20 mg/L) for all solution compositions at hydroxide concentrations from 0.1 to 17 molar (2) carbonate, sulfate, and aluminate are not effective complexants for uranium at high hydroxide concentration, (3) uranium solubility decreases with increasing temperature for most alkaline salt solutions, and (4) uranium solubility increases with changes in solution chemistry that reflect aging of high level waste (increase in nitrite and carbonate concentrations, decrease in nitrate and hydroxide concentrations). A predictive model for the concentration of uranium as a function of component concentrations and temperature was fitted to the data. All of the solution components and temperature were found to be significant. There is a significant lack of fit for the model, which suggests that the dependence on the uranium solubility over the wide range of solution compositions is non-linear and/or that there are other uncontrolled parameters which are important to the uranium solubility.
Solutions of the Bohr Hamiltonian, a compendium
NASA Astrophysics Data System (ADS)
Fortunato, L.
2005-10-01
The Bohr Hamiltonian, also called collective Hamiltonian, is one of the cornerstones of nuclear physics and a wealth of solutions (analytic or approximated) of the associated eigenvalue equation have been proposed over more than half a century (confining ourselves to the quadrupole degree of freedom). Each particular solution is associated with a peculiar form for the V(β,γ) potential. The large number and the different details of the mathematical derivation of these solutions, as well as their increased and renewed importance for nuclear structure and spectroscopy, demand a thorough discussion. It is the aim of the present monograph to present in detail all the known solutions in γ-unstable and γ-stable cases, in a taxonomic and didactical way. In pursuing this task we especially stressed the mathematical side leaving the discussion of the physics to already published comprehensive material. The paper contains also a new approximate solution for the linear potential, and a new solution for prolate and oblate soft axial rotors, as well as some new formulae and comments. The quasi-dynamical SO(2) symmetry is proposed in connection with the labeling of bands in triaxial nuclei.
Solute transport by a volatile solvent
NASA Astrophysics Data System (ADS)
Brown, Glenn O.; McWhorter, David B.
1990-05-01
In relatively dry porous media, water is transported as both liquid and vapor. Exact knowledge of this two-phase transport, and the phase transfer of water associated with it, is required for the prediction of solute transport. Combined liquid and vapor transport is examined starting from basic principles. An analytic solution is presented for the case of isothermal, transient, one-dimensional sorption of water with constant liquid content boundaries. A relation is also obtained for the evaporation and condensation within the flow field. A numerical solution for the solute transport is obtained which takes maximum advantage of the analytical flow solution. Using the properties of Lurgi retorted oil shale, several special cases are examined which show the relative importance of the separate phases in the total transport of water, the effects on the phase transfer, and the solute transport. It is expected that these methods and results can be applied to other problems in multiple phase transport, such as hazardous waste disposal and pesticide transport.
NASA Astrophysics Data System (ADS)
Martel, Richard; Lefebvre, René; Gélinas, Pierre J.
1998-03-01
A large sand column experiment is used to illustrate the principles of complex organic contaminants (DNAPL) recovery by a chemical solution containing an alcohol ( n-butanol), a surfactant (Hostapur SAS), and two solvents ( d-limonene and toluene). The washing solution is pushed by viscous polymer solutions to keep the displacement stable. The main NAPL recovery mechanisms identified are: (1) immiscible displacement by oil saturation increase (oil swelling), oil viscosity reduction, interfacial tension lowering, and relative permeability increase; (2) miscible NAPL displacement by solubilization. Most of the NAPL was recovered in a Winsor, type II system ahead of the washing solution. The 0.8 pore volume (PV) of alcohol-surfactant-solvent solution injected recovered more than 89% of the initial residual DNAPL saturation (0.195). Winsor system types were determined by visual observation of phases and confirmed by electrical resistivity measurements of phases and water content measurements in the oleic phase. Viscosity and density lowering of the oleic phase was made using solvents and alcohol transfer from the washing solution. Small sand column tests are performed to check different rinsing strategies used to minimize washing solution residual ingredients which can be trapped in sediments. An alcohol/surfactant rinsing solution without solvent, injected behind the washing solution, minimizes solvent trapping in sediments. More than five pore volumes of polymer solution and water must be injected after the rinsing solution to decrease alcohol and SAS concentrations in sediments to an acceptable level. To obtain reasonable trapped surfactant concentrations in sediments, the displacement front between the rinsing solution and the subsequent the following polymer solution has to be stable.
What Solutions Caused Noachian Weathering on Mars?
NASA Astrophysics Data System (ADS)
Zolotov, M. Y.
2015-12-01
The stratified sequence of Al-rich and Fe/Mg phyllosilicates in Noachian formations indicates widespread chemical weathering of mafic materials [1]. The composition of alteration solutions could be inferred from the mineralogy of weathering profiles and models for water-rock interaction. We have developed numerical models for basalt weathering by acidic solutions with different concentrations of weak (H2CO3) and strong (H2SO4, HCl) acids equilibrated with low- and high-pressure CO2 atmospheres. The results show that the observed clay stratigraphies could be produced by neutral to strongly acidic solutions. Weathering by solutions equilibrated with dense CO2 atmospheres produces abundant carbonates at depth, which are not observed in clay stratigraphies. The development of weathering profiles by S-, Cl-free solutions equilibrated with 6 mbar CO2 requires large volumes of water. These volumes are inconsistent with density and orientation of Noachian valley networks and climate models [3-5]. Weathering by sulfate-free fluids does not produce abundant Ca sulfates reported in the Mawrth Valley region [2]. Weathering by low-pH H2SO4-bearing solutions does not require elevated water/rock ratios, a warm climate, or a dense CO2 atmosphere. It leads to formation of Ca sulfates in middle parts of weathering profiles together with neutralized Mg-rich sulfate solutions at depth. The weathering could have occurred through transient volcanism- and impact-generated supply of strong acids, and volcanism-, impact-, obliquity-related warming and partial ice melting, consistent with climate models [3-5]. Refs: [1] Carter, J. et al. (2015), Icarus 248, 373-382. [2] Wray, J. J. et al. (2010), Icarus 209, 416-421. [3] Wordsworth, R. et al. (2013), Icarus 222, 1-19. [4] Mischna, M. A. et al. (2013), J. Geophys. Res. Planets 118, 518-576. [5] Halevy, I., Head, J.W. (2014), Nature Geosci. 7, 865-868.
Analytic solutions of an unclassified artifact /
Trent, Bruce C.
2012-03-01
This report provides the technical detail for analytic solutions for the inner and outer profiles of the unclassified CMM Test Artifact (LANL Part Number 157Y-700373, 5/03/2001) in terms of radius and polar angle. Furthermore, analytic solutions are derived for the legacy Sheffield measurement hardware, also in terms of radius and polar angle, using part coordinates, i.e., relative to the analytic profile solutions obtained. The purpose of this work is to determine the exact solution for the “cosine correction” term inherent to measurement with the Sheffield hardware. The cosine correction is required in order to interpret the actual measurements taken by the hardware in terms of an actual part definition, or “knot-point spline definition,” that typically accompanies a component drawing. Specifically, there are two portions of the problem: first an analytic solution must be obtained for any point on the part, e.g., given the radii and the straight lines that define the part, it is required to find an exact solution for the inner and outer profile for any arbitrary polar angle. Next, the problem of the inspection of this part must be solved, i.e., given an arbitrary sphere (representing the inspection hardware) that comes in contact with the part (inner and outer profiles) at any arbitrary polar angle, it is required to determine the exact location of that intersection. This is trivial for the case of concentric circles. In the present case, however, the spherical portion of the profiles is offset from the defined center of the part, making the analysis nontrivial. Here, a simultaneous solution of the part profiles and the sphere was obtained.
Simple solutions for reduced fish farm hazards.
Myers, Melvin L; Cole, Henry P
2009-01-01
Aquaculture poses emerging challenges for agricultural safety and health. Fish farming has many of the same hazards as other types of farming, but it also poses additional hazards associated with water impoundments and night-time work. In a multidisciplinary approach, researchers from four universities are identifying occupational hazards in fish farming and identifying no-cost or low-cost "simple solutions" to reduce or eliminate them. Simple solutions are discovered through farm visits so as to understand the countermeasures that individual stakeholders have taken to protect their workforce, and these countermeasures are documented and photographed to inform other farmers of these solutions. Equipping tractors with rollover protective structures is a standard practice to protect operators from serious injury in the event of an overturn. Other solutions identified include eliminating the need to climb feed bins to open and close the hatch for feed delivery by using a pull-cable at ground level. This simple technology eliminates the exposure to falling from an elevation, a risk that accounts for at least one reported death of a worker on a fish farm. Another solution is to replace metal paddles on a hatchery trough with plastic paddles that if and when entangled in a worker's hair or clothing slip on the rotating drive shaft and thus reduce laceration and entanglement injuries. Another simple solution to prevent entanglements in large pond aerators, used to mechanically dissolve oxygen into the water, that are operated by farm tractor power take-off shafts is to use electrically powered aerators. Bubble-type aerators are safer than electrically powered paddle aerators because workers are shielded from moving parts. Many additional simple solutions have been identified for a range of tasks in this environment. PMID:19437271
Electrical conductivity of acidic sulfate solution
NASA Astrophysics Data System (ADS)
Majima, Hiroshi; Peters, Ernest; Awakura, Yasuhiro; Park, Sung Kook
1987-03-01
The electrical conductivities of the aqueous solution system of H2SO4-MSO4 (involving ZnSO4, MgSO4, Na2SO4, and (NH4)2SO4), reported by Tozawa et al., were examined in terms of a (H2O) and H+ ion concentration. The equations to compute the concentrations of various species in aqueous sulfuric acid solutions containing metal sulfates were derived for a typical example of the H2SO4-ZnSO4-MgSO4-(Na2SO4)-H2O system. It was found that the H+ ion concentrations in concentrated sulfuric acid solutions corresponding to practical zinc electrowinning solutions are very high and remain almost constant with or without the addition of metal sulfates. The addition of metal sulfates to aqueous sulfuric acid solution causes a decrease in electrical conductivity, and this phenomenon is attributed to a decrease in water activity, which reflects a decrease in the amount of free water. The relationship between conductivity and water activity at a constant H+ ion concentration is independent of the kind of sulfates added. On the other hand, any increase in H+ ion concentration results in an increase in electrical conductivity. A novel method for the prediction of electrical conductivity of acidic sulfate solution is proposed that uses the calculated data of water activity and the calculated H+ ion concentration. Also, the authors examined an extension of the Robinson-Bower equation to calculate water activity in quarternary solutions based on molarity instead of molality, and found that such calculated values are in satisfactory agreement with those determined experimentally by a transpiration method.
The effect of solute-membrane interaction on solute permeation under supersaturated conditions.
Zhang, Jingsi; Sun, Mingjing; Fan, Aiping; Wang, Zheng; Zhao, Yanjun
2013-01-30
The purpose of this work was to investigate the effect of solute-membrane interaction under supersaturated conditions on the transport of model solute (salicylic acid) across poly(dimethylsiloxane) (PDMS) membrane. Supersaturated systems with a degree of saturation (DS) up to 8 were prepared using a molecular form technique with water as the vehicle to minimize the vehicle-membrane interaction. The spectroscopic and thermal analysis revealed the presence of both hydrogen bonding and nonpolar interaction between the solute and PDMS. Upon treatment by supersaturated solutions the degree of solute-membrane interaction increased with increasing DS. This enhanced the barrier property of PDMS and thus led to the flux attenuation compared to that calculated by Higuchi equation. This work highlighted the importance of solute-membrane interaction under supersaturation in the flux reduction, which should be considered when designing, and optimizing supersaturated topical and transdermal drug delivery systems. PMID:23178214
NASA Astrophysics Data System (ADS)
Ishiki, Hamilton Mitsugu; Alemán, Carlos; Galembeck, Sérgio Emanuel
1998-05-01
Flavone and isoflavone are an important class of secondary metabolites that are widely distributed in nature. In this Letter we have determined the conformational preferences of each compound in the gas phase, aqueous solution and organic solution. Gas-phase calculations were performed using AM1, MNDO, HF/3-21G, HF/6-31G(d) and B3-LYP/6-31G(d) calculations. Besides solution calculations were performed using the MST solvation model.
Helping Families Search for Solutions: Working with Adolescents
ERIC Educational Resources Information Center
Paylo, Matthew J.
2005-01-01
In this column, the author focuses on the ways that family counselors can use solution-based therapies (solution-oriented and solution-focused) to work with families with adolescents in individual and/or family therapy. The theoretical foundation for solution-based therapies suggests techniques that help families focus on solutions and not remain…
Pictorial Analogies XI: Concentrations and Acidity of Solutions.
ERIC Educational Resources Information Center
Fortman, John J.
1994-01-01
Presents pictorial analogies of several concepts relating to solutions for chemistry students. These include concentration of solution, strength of solution, supersaturated solution, and conjugate acid-base pairs. Among the examples are comparison of acid strength to percentage of strong soldiers or making supersaturated solution analogous to a…
Stability of diphenylalanine peptide nanotubes in solution
NASA Astrophysics Data System (ADS)
Andersen, Karsten Brandt; Castillo-Leon, Jaime; Hedström, Martin; Svendsen, Winnie Edith
2011-03-01
Over the last couple of years, self-organizing nanotubes based on the dipeptide diphenylalanine have received much attention, mainly as possible building blocks for the next generation of biosensors and as drug delivery systems. One of the main reasons for this large interest is that these peptide nanotubes are believed to be very stable both thermally and chemically. Previously, the chemical and thermal stability of self-organizing structures has been investigated after the evaporation of the solvent. However, it was recently discovered that the stability of the structures differed significantly when the tubes were in solution. It has been shown that, in solution, the peptide nanotubes can easily be dissolved in several solvents including water. It is therefore of critical importance that the stability of the nanotubes in solution and not after solvent evaporation be investigated prior to applications in which the nanotube will be submerged in liquid. The present article reports results demonstrating the instability and suggests a possible approach to a stabilization procedure, which drastically improves the stability of the formed structures. The results presented herein provide new information regarding the stability of self-organizing diphenylalanine nanotubes in solution.Over the last couple of years, self-organizing nanotubes based on the dipeptide diphenylalanine have received much attention, mainly as possible building blocks for the next generation of biosensors and as drug delivery systems. One of the main reasons for this large interest is that these peptide nanotubes are believed to be very stable both thermally and chemically. Previously, the chemical and thermal stability of self-organizing structures has been investigated after the evaporation of the solvent. However, it was recently discovered that the stability of the structures differed significantly when the tubes were in solution. It has been shown that, in solution, the peptide nanotubes can
NASA Astrophysics Data System (ADS)
Yan, Zhenya; Bluman, George
2002-11-01
The special exact solutions of nonlinearly dispersive Boussinesq equations (called B( m, n) equations), utt- uxx- a( un) xx+ b( um) xxxx=0, is investigated by using four direct ansatze. As a result, abundant new compactons: solitons with the absence of infinite wings, solitary patterns solutions having infinite slopes or cups, solitary waves and singular periodic wave solutions of these two equations are obtained. The variant is extended to include linear dispersion to support compactons and solitary patterns in the linearly dispersive Boussinesq equations with m=1. Moreover, another new compacton solution of the special case, B(2,2) equation, is also found.
NASA Astrophysics Data System (ADS)
Yoshida, Norio; Kato, Shigeki
2000-09-01
A new approach to ab initio electronic structure calculations of solute molecules in solution is presented. Combined with the molecular Ornstein-Zernike (MOZ) integral equation theory for polyatomic liquids, solute electronic wave function and solvent distribution around a solute are determined in a self-consistent manner. The hypernetted chain approximation is employed for solving the MOZ equation. In order to describe the short-range solute-solvent interactions, the effective potential operating solute electron is placed on a solute molecule, which is determined by a least-squares fitting to ab initio exchange repulsion/charge transfer energies. The present method, referred to as the MOZ self-consistent-field (SCF) method, is applied to a solute H2O molecule in water solvent. The solvent shift for the vertical excitation to the nπ* state of H2CO in aqueous solution is also examined. The results obtained by the MOZ-SCF calculations are compared with those by the reference interaction site model-SCF theory and the polarizable continuum model.
Solubility of pllutonium in alkaline salt solutions
Hobbs, D.T.; Edwards, T.B.
1993-02-26
Plutonium solubility data from several studies have been evaluated. For each data set, a predictive model has been developed where appropriate. In addition, a statistical model and corresponding prediction intervals for plutonium solubility as a quadratic function of the hydroxide concentration have been developed. Because of the wide range of solution compositions, the solubility of plutonium can vary by as much as three orders of magnitude for any given hydroxide concentration and still remain within the prediction interval. Any nuclear safety assessments that depend on the maximum amount of plutonium dissolved in alkaline salt solutions should use concentrations at least as great as the upper prediction limits developed in this study. To increase the confidence in the prediction model, it is recommended that additional solubility tests be conducted at low hydroxide concentrations and with all of the other solution components involved. To validate the model for application to actual waste solutions, it is recommended that the plutonium solubilities in actual waste solutions be determined and compared to the values predicted by the quadratic model.
Interactive solution-adaptive grid generation
NASA Technical Reports Server (NTRS)
Choo, Yung K.; Henderson, Todd L.
1992-01-01
TURBO-AD is an interactive solution-adaptive grid generation program under development. The program combines an interactive algebraic grid generation technique and a solution-adaptive grid generation technique into a single interactive solution-adaptive grid generation package. The control point form uses a sparse collection of control points to algebraically generate a field grid. This technique provides local grid control capability and is well suited to interactive work due to its speed and efficiency. A mapping from the physical domain to a parametric domain was used to improve difficulties that had been encountered near outwardly concave boundaries in the control point technique. Therefore, all grid modifications are performed on a unit square in the parametric domain, and the new adapted grid in the parametric domain is then mapped back to the physical domain. The grid adaptation is achieved by first adapting the control points to a numerical solution in the parametric domain using control sources obtained from flow properties. Then a new modified grid is generated from the adapted control net. This solution-adaptive grid generation process is efficient because the number of control points is much less than the number of grid points and the generation of a new grid from the adapted control net is an efficient algebraic process. TURBO-AD provides the user with both local and global grid controls.
Production of 89Sr in solution reactor.
Chuvilin, D Yu; Khvostionov, V E; Markovskij, D V; Pavshook, V A; Ponomarev-Stepnoy, N N; Udovenko, A N; Shatrov, A V; Vereschagin, Yu I; Rice, J; Tome, L A
2007-10-01
The new method for medical (89)Sr production in a reactor with solution fuel is proposed which is characterized by simplicity, high production efficiency and low buildup of radioactive waste. The main advantages of the new technology were validated by numerous experiments. The proposed new technology selectively extracts (89)Sr from a fuel of solution reactor and precludes penetration of (90)Sr into the final product. This method is based on the presence of gaseous radionuclide (89)Kr (T(1/2)=190.7s) in the decay chain (89)Se-->(89)Br-->(89)Kr-->(89)Rb-->(89)Sr. The performed experiments on taking the gas probes from internal volume of the solution 20 kW mini-reactor "Argus" have confirmed that the mechanism for (89)Sr delivery to the sorption volume of the reactor experimental loop is based on transport of gaseous (89)Sr predecessor-radionuclide (89)Kr. According to the measurements of radioactive impurities in a final (89)SrCl(2) solution, the filtration of the gas flow with cermet filters followed by cleaning of (89)Sr chloride solution in chromatographic columns with DOWEX-50 x 8 or Sr-Resin ensures reception of (89)Sr fully meeting the requirements for medical application. The experimental estimations have shown that the proposed new technology is multiply more productive than the traditional industrial methods of (89)Sr reception. PMID:17611114
Exact solutions for extreme black hole magnetospheres
NASA Astrophysics Data System (ADS)
Lupsasca, Alexandru; Rodriguez, Maria J.
2015-07-01
We present new exact solutions of Force-Free Electrodynamics (FFE) in the Near-Horizon region of an Extremal Kerr black hole (NHEK) and offer a complete classifica-tion of the subset that form highest-weight representations of the spacetime's SL(2, ℝ)×U(1) isometry group. For a natural choice of spacetime embedding of this isometry group, the SL(2, ℝ) highest-weight conditions lead to stationary solutions with non-trivial angular de-pendence, as well as axisymmetry when the U(1)-charge vanishes. In addition, we unveil a hidden SL(2, ℂ) symmetry of the equations of FFE that stems from the action of a complex automorphism group, and enables us to generate an SL(2, ℂ) family of (generically time-dependent) solutions. We then obtain still more general solutions with less symmetry by appealing to a principle of linear superposition that holds for solutions with collinear cur-rents. This allows us to resum the highest-weight primaries and their SL(2, ℝ)-descendants.
Black brane solutions governed by fluxbrane polynomials
NASA Astrophysics Data System (ADS)
Ivashchuk, V. D.
2014-12-01
A family of composite black brane solutions in the model with scalar fields and fields of forms is presented. The metric of any solution is defined on a manifold which contains a product of several Ricci-flat 'internal' spaces. The solutions are governed by moduli functions Hs (s = 1 , … , m) obeying non-linear differential equations with certain boundary conditions imposed. These master equations are equivalent to Toda-like equations and depend upon the non-degenerate (m × m) matrix A. It was conjectured earlier that the functions Hs should be polynomials if A is a Cartan matrix for some semisimple finite-dimensional Lie algebra (of rank m). It is shown that the solutions to master equations may be found by using so-called fluxbrane polynomials which can be calculated (in principle) for any semisimple finite-dimensional Lie algebra. Examples of dilatonic charged black hole (0-brane) solutions related to Lie algebras A1, A2, C2 and G2 are considered.
Lead chloride crystal growth from boiling solutions
NASA Astrophysics Data System (ADS)
Veintemillas-Verdaguer, S.; Rodríguez-Clemente, R.; Torrent-Burgues, J.
1993-03-01
Lead chloride single crystals can be grown from boiling solutions using KNO3-H20 solutions as a solvent. Crystals of 1 mm size produced by gel-growth technique were used as seeds. The solubility of PbC12 increases almost linearly with the KNO3 molality being 0.63m in a 7m KNO3 aqueous solutions at 105°C and pH = 2.6; this increase is related to the decrease of the activity coefficient of lead chloride in these solutions. In the first experiments, the supersaturation was attained by solvent extraction, but due to the simultaneous changes in the concentration of the KNO3 mineralizer during the extraction, the growth rate was irregular and defective crystals were obtained. The experimental set-up was therefore modified and a transport technique was added to the system in order to feed the boiling reactor continuously with fresh lead chloride solution. The growth of the crystals takes place at constant concentration of KNO3 in these new conditions. With this experimental modification, isometric PbCI2 crystals of up to lcm size were obtained in three weeks. The observed morphology is close to that calculated by Woensdregt and Hartmann [J. Crystal Growth 87(1988)561].
Magnetic Control of Solutal Buoyancy Driven Convection
NASA Technical Reports Server (NTRS)
Ramachandran, N.; Leslie, F. W.
2003-01-01
Volumetric forces resulting from local density variations and gravitational acceleration cause buoyancy induced convective motion in melts and solutions. Solutal buoyancy is a result of concentration differences in an otherwise isothermal fluid. If the fluid also exhibits variations in magnetic susceptibility with concentration then convection control by external magnetic fields can be hypothesized. Magnetic control of thermal buoyancy induced convection in ferrofluids (dispersions of ferromagnetic particles in a carrier fluid) and paramagnetic fluids have been demonstrated. Here we show the nature of magnetic control of solutal buoyancy driven convection of a paramagnetic fluid, an aqueous solution of Manganese Chloride hydrate. We predict the critical magnetic field required for balancing gravitational solutal buoyancy driven convection and validate it through a simple experiment. We demonstrate that gravity driven flow can be completely reversed by a magnetic field but the exact cancellation of the flow is not possible. This is because the phenomenon is unstable. The technique can be applied to crystal growth processes in order to reduce convection and to heat exchanger devices for enhancing convection. The method can also be applied to impose a desired g-level in reduced gravity applications.
Absorption spectra of cold dilute solid solutions
Holland, R.F.; Maier, W.B. II; Freund, S.; Beattie, W.H.
1983-06-01
Infrared absorption spectra have been obtained for some compounds trapped in crystalline solids by freezing liquid Xe, Kr, Ar, or CH/sub 4/ solutions. The optical quality of the solid solutions is good, and they have been cooled to approx.80 K in 1.35 cm sample thicknesses to study the absorption in fundamental vibrational bands of the solutes. In the cases discussed, the bands are narrow, with observed full widths at half-maximum absorbance 0.05--0.30 cm/sup -1/ greater than the instrumental resolution (0.18--0.29 cm/sup -1/). The spectra appear to be free of ''multiple site'' and solute aggregate absorptions. Spectra displaying isotropic splitting in bands of natural BCl/sub 3/, SeF/sub 6/, OsO/sub 4/, TiCl/sub 4/, and MoF/sub 6/ are presented, and band frequencies are compared with some results obtained in evaporative matrices, in the gas phase, and in liquid solutions. For this comparison we have obtained some spectra of SeF/sub 6/ and BCl/sub 3/ gas.
Fluid Mechanical Properties of Silkworm Fibroin Solutions
NASA Astrophysics Data System (ADS)
Matsumoto, Akira
2005-11-01
The aqueous solution behavior of silk fibroin is of interest due to the assembly and processing of this protein related to the spinning of protein fibers that exhibit remarkable mechanical properties. To gain insight into the origins of this functional feature, it is desired to determine how the protein behaves under a range of solution conditions. Pure fibroin at different concentrations in water was studied for surface tension, as a measure of surfactancy. In addition, shear induced changes on these solutions in terms of structure and morphology was also determined. Fibroin solutions exhibited shear rate-sensitive viscosity changes and precipitated at a critical shear rate where a dramatic increase of 75-150% of the initial value was observed along with a decrease in viscosity. In surface tension measurements, critical micelle concentrations were in the range of 3-4% w/v. The influence of additional factors, such as sericin protein, divalent and monovalent cations, and pH on the solution behavior in relation to structural and morphological features will also be described.
Exact Vlasov Solutions of Kinetic Flux Ropes
NASA Astrophysics Data System (ADS)
Ng, C. S.
2014-12-01
Small-scale magnetic flux ropes have been observed to form within the diffusion region in three-dimensional (3D) kinetic simulations of magnetic reconnection. Such 3D structures and the 2D version of them (plasmoids, secondary islands) could have important dynamical effects on the reconnection physics itself. Small-scale flux ropes have also been observed within the interplanetary space. We have found exact time-steady solutions of kinetic flux ropes by generalizing exact solutions of 2D Bernstein-Greene-Kruskal (BGK) modes in a magnetized plasma with finite magnetic field strength [Ng, Bhattacharjee, and Skiff, Phys. Plasmas 13, 055903 (2006)] to cases with azimuthal magnetic fields so that these structures carry electric current as well as steady electric and magnetic fields. Such fully nonlinear solutions now satisfy exactly the Vlasov-Poisson-Ampere system of equations. Solutions like these could describe small-scale flux ropes observed in reconnection diffusion regions or in the interplanetary space. They are also exact nonlinear solutions that can be used to validate numerical schemes for kinetic simulations. This work is supported by a National Science Foundation grant PHY-1004357.
Detection of solute segregation at grain boundaries
Briceno-Valero, J.; Gronsky, R.
1980-03-01
Studies of grain boundary segregation in metallurgical systems are traditionally based upon the premise that grain boundaries are more likely sites for solute atoms than their surrounding grains. This idea is manifested in experimental studies which distinguish the solute concentration at boundaries from that of grain interiors using various spectroscopic techniques, including more recently, energy dispersive x-ray analysis in TEM/STEM instruments. A typical study consists of spot or line scans across a grain boundary plane in order to detect concentration gradients at the boundary region. It has also been pointed out that there are rather severe problems in quantitatively determining the absolute solute concentration within the grain boundary, and data correction schemes for this situation have been proposed. The present paper is concerned with an alternative study of grain boundary segregation where the distribution of solute atoms along the boundary plane (as opposed to that across the boundary plane) is sought. The interest here is to establish whether or not a relationship exists between the structural defect configuration of the boundary plane and site preference for solute segregation.
Solution-based nanoengineering of materials.
Criscenti, Louise Jacqueline; Spoerke, Erik David; Liu, Jun; Voigt, James A.; Cygan, Randall Timothy; Machesky, Michael L.; Tian, Zhengrong Ryan; McKenzie, Bonnie Beth
2005-02-01
Solution-based synthesis is a powerful approach for creating nano-structured materials. Although there have been significant recent successes in its application to fabricating nanomaterials, the general principles that control solution synthesis are not well understood. The purpose of this LDRD project was to develop the scientific principles required to design and build unique nanostructures in crystalline oxides and II/VI semiconductors using solution-based molecular self-assembly techniques. The ability to synthesize these materials in a range of different nano-architectures (from controlled morphology nanocrystals to surface templated 3-D structures) has provided the foundation for new opportunities in such areas as interactive interfaces for optics, electronics, and sensors. The homogeneous precipitation of ZnO in aqueous solution was used primarily as the model system for the project. We developed a low temperature, aqueous solution synthesis route for preparation of large arrays of oriented ZnO nanostructures. Through control of heterogeneous nucleation and growth, methods to predicatively alter the ZnO microstructures by tailoring the surface chemistry of the crystals were established. Molecular mechanics simulations, involving single point energy calculations and full geometry optimizations, were developed to assist in selecting appropriate chemical systems and understanding physical adsorption and ultimately growth mechanisms in the design of oxide nanoarrays. The versatility of peptide chemistry in controlling the formation of cadmium sulfide nanoparticles and zinc oxide/cadmium sulfide heterostructures was also demonstrated.
Spherically Symmetric Solutions of Light Galileon
NASA Astrophysics Data System (ADS)
Momeni, D.; Houndjo, M. J. S.; Güdekli, E.; Rodrigues, M. E.; Alvarenga, F. G.; Myrzakulov, R.
2016-02-01
We have been studied the model of light Galileon with translational shift symmetry ϕ → ϕ + c. The matter Lagrangian is presented in the form {L}_{φ }= -η (partial φ )2+β G^{μ ν }partial _{μ }φ partial _{ν }φ . We have been addressed two issues: the first is that, we have been proven that, this type of Galileons belong to the modified matter-curvature models of gravity in type of f(R,R^{μ ν }T_{μ ν }m). Secondly, we have been investigated exact solution for spherically symmetric geometries in this model. We have been found an exact solution with singularity at r = 0 in null coordinates. We have been proven that the solution has also a non-divergence current vector norm. This solution can be considered as an special solution which has been investigated in literature before, in which the Galileon's field is non-static (time dependence). Our scalar-shift symmetrized Galileon has the simple form of ϕ = t, which it is remembered by us dilaton field.
Supersymmetric solutions to Euclidean Romans supergravity
NASA Astrophysics Data System (ADS)
Alday, Luis F.; Fluder, Martin; Gregory, Carolina Matte; Richmond, Paul; Sparks, James
2016-02-01
We study Euclidean Romans supergravity in six dimensions with a non-trivial Abelian R-symmetry gauge field. We show that supersymmetric solutions are in one-to-one correspondence with solutions to a set of differential constraints on an SU(2) structure. As an application of our results we (i) show that this structure reduces at a conformal boundary to the five-dimensional rigid supersymmetric geometry previously studied by the authors, (ii) find a general expression for the holographic dual of the VEV of a BPS Wilson loop, matching an exact field theory computation, (iii) construct holographic duals to squashed Sasaki-Einstein backgrounds, again matching to a field theory computation, and (iv) find new analytic solutions.
Method of lines solution of Richards` equation
Kelley, C.T.; Miller, C.T.; Tocci, M.D.
1996-12-31
We consider the method of lines solution of Richard`s equation, which models flow through porous media, as an example of a situation in which the method can give incorrect results because of premature termination of the nonlinear corrector iteration. This premature termination arises when the solution has a sharp moving front and the Jacobian is ill-conditioned. While this problem can be solved by tightening the tolerances provided to the ODE or DAE solver used for the temporal integration, it is more efficient to modify the termination criteria of the nonlinear solver and/or recompute the Jacobian more frequently. In this paper we continue previous work on this topic by analyzing the modifications in more detail and giving a strategy on how the modifications can be turned on and off in response to changes in the character of the solution.
Solution growth of crystals in zero gravity
NASA Technical Reports Server (NTRS)
Lai, R. B.
1982-01-01
A series of experiments will be performed in which triglycine sulfate (TGS) crystals will be grown by a low-temperature solution growth technique in the microgravity environment of the orbital Spacelab. Triglycine sulfate (TGS) crystals will be grown in the Fluid Experiment System (FES) facility on Spacelab 3 by slowly extracting heat at a controlled rate through a seed crystal of TGS suspended on an insulated sting in a saturated solution of TGS. The FES rack assembly designed for SL-3 is shown in Figure I-1, and a detailed view of the test cell layout is presented in Figure I-2. Variations in the liquid density, solution concentration and temperature around the growing crystal will be studied using a variety of techniques, such as schlieren, shadowgraph, and interferometric measurements. Growth in Earth gravity will also be studied by the same optical techniques, and in both cases the resulting crystalline features will be compared and correlated with the growth conditions.
Integer Solutions of a Special Diophantine Equation
NASA Astrophysics Data System (ADS)
Özkoç, Arzu; Tekcan, Ahmet
2011-09-01
Let t≠1 be an integer. In this work, we determine the integer solutions of Diophantine equation D:x2+(2-t2)y2+(-2t2-2t+2)x+(2t5-6t3+4t)y-t8+4t6-4t4+2t3+t2-2t = 0 over Z and also over finite fields Fp for primes p≥2. Also we derive some recurrence relations on the integer solutions (xn,yn) of D and formulate the the n—th solution (xn,yn) by using the simple continued fraction expansion of xn/yn.
Volkov solutions for relativistic quantum plasmas
Mendonca, J. T.; Serbeto, A.
2011-02-15
This work studies the electron quantum states, as determined by the Dirac equation, in the field of electrostatic and electromagnetic waves in a plasma. We discuss the main differences with respect to the vacuum case, and the assumptions under which the vacuum Volkov solutions can be adapted to a plasma. The case of ultrashort electromagnetic wave pulses is also discussed. We also consider the electron states in the field of an electron plasma wave. Modified Volkov solutions of the Dirac equation can also be found. For electron plasma waves such that the phase velocity becomes close to the speed of light, these solutions are exact. Finally, we consider electron states in the field of two waves in a plasma, with relevance to the mixed case where one of the waves is electrostatic and the other is electromagnetic.
Cadmium zinc sulfide by solution growth
Chen, Wen S.
1992-05-12
A process for depositing thin layers of a II-VI compound cadmium zinc sulfide (CdZnS) by an aqueous solution growth technique with quality suitable for high efficiency photovoltaic or other devices which can benefit from the band edge shift resulting from the inclusion of Zn in the sulfide. A first solution comprising CdCl.sub.2 2.5H.sub.2 O, NH.sub.4 Cl, NH.sub.4 OH and ZnCl.sub.2, and a second solution comprising thiourea ((NH.sub.2).sub.2 CS) are combined and placed in a deposition cell, along with a substrate to form a thin i.e. 10 nm film of CdZnS on the substrate. This process can be sequentially repeated with to achieve deposition of independent multiple layers having different Zn concentrations.
Combined LAURA-UPS hypersonic solution procedure
NASA Technical Reports Server (NTRS)
Wood, William A.; Thompson, Richard A.
1993-01-01
A combined solution procedure for hypersonic flowfields around blunted slender bodies was implemented using a thin-layer Navier-Stokes code (LAURA) in the nose region and a parabolized Navier-Stokes code (UPS) on the after body region. Perfect gas, equilibrium air, and non-equilibrium air solutions to sharp cones and a sharp wedge were obtained using UPS alone as a preliminary step. Surface heating rates are presented for two slender bodies with blunted noses, having used LAURA to provide a starting solution to UPS downstream of the sonic line. These are an 8 deg sphere-cone in Mach 5, perfect gas, laminar flow at 0 and 4 deg angles of attack and the Reentry F body at Mach 20, 80,000 ft equilibrium gas conditions for 0 and 0.14 deg angles of attack. The results indicate that this procedure is a timely and accurate method for obtaining aerothermodynamic predictions on slender hypersonic vehicles.
REdiii: a pipeline for automated structure solution
Bohn, Markus-Frederik; Schiffer, Celia A.
2015-01-01
High-throughput crystallographic approaches require integrated software solutions to minimize the need for manual effort. REdiii is a system that allows fully automated crystallographic structure solution by integrating existing crystallographic software into an adaptive and partly autonomous workflow engine. The program can be initiated after collecting the first frame of diffraction data and is able to perform processing, molecular-replacement phasing, chain tracing, ligand fitting and refinement without further user intervention. Preset values for each software component allow efficient progress with high-quality data and known parameters. The adaptive workflow engine can determine whether some parameters require modifications and choose alternative software strategies in case the preconfigured solution is inadequate. This integrated pipeline is targeted at providing a comprehensive and efficient approach to screening for ligand-bound co-crystal structures while minimizing repetitiveness and allowing a high-throughput scientific discovery process. PMID:25945571
The world of DNA in glycol solution.
Lindahl, Tomas
2016-05-23
The properties of high-molecular-weight DNA are usually investigated in neutral aqueous solutions. Strong acids and strong alkaline solutions are obviously unsuitable, as are corrosive solvents, and DNA is insoluble in most organic solvents; precipitation of DNA from aqueous solution with ethanol or isopropanol is therefore frequently used as a purification step. An exception is the organic solvent glycol (ethylene glycol, 1,2-ethanediol, dihydroxyethane, HOCH2CH2OH) and the similar solvent glycerol. Double-stranded DNA remains soluble in salt-containing glycol, although it precipitates in polyethylene glycol. (DNA also remains soluble in formamide, but the double-helical structure of DNA is much less stable in this solvent than in glycol.) However, DNA in glycol has been little investigated during the last half-century. PMID:27211487
Approximated solutions to Born-Infeld dynamics
NASA Astrophysics Data System (ADS)
Ferraro, Rafael; Nigro, Mauro
2016-02-01
The Born-Infeld equation in the plane is usefully captured in complex language. The general exact solution can be written as a combination of holomorphic and anti-holomorphic functions. However, this solution only expresses the potential in an implicit way. We rework the formulation to obtain the complex potential in an explicit way, by means of a perturbative procedure. We take care of the secular behavior common to this kind of approach, by resorting to a symmetry the equation has at the considered order of approximation. We apply the method to build approximated solutions to Born-Infeld electrodynamics. We solve for BI electromagnetic waves traveling in opposite directions. We study the propagation at interfaces, with the aim of searching for effects susceptible to experimental detection. In particular, we show that a reflected wave is produced when a wave is incident on a semi-space containing a magnetostatic field.
Solute transport in heterogeneous porous formations
NASA Astrophysics Data System (ADS)
Demmy, George Gary, Jr.
1999-10-01
This work quantifies relationships between the spatial, or Eulerian, distribution of the properties of a chemically and physically heterogeneous porous medium and those as observed along the natural, or Lagrangian, trajectories that a fluid particle traces in a steady and irrotational flow. From these relationships, expressions that relate the transport of solutes through the porous medium along the natural trajectories to the aforementioned Eulerian distributions are developed. The effects of injection mode upon global measures of transport as reflected by the temporal moments of breakthrough curves and spatial moments of a solute plume are developed. The coupled effects of correlation of a linear equilibrium sorption to the underlying log hydraulic conductivity field and injection mode on the evolving temporal moments of mass breakthrough curve and the coupled effects of correlation of a first-order decay coefficient and injection mode upon the spatial moments of a solute plume are examined.
Robinson-Trautman solution with nonlinear electrodynamics
NASA Astrophysics Data System (ADS)
Tahamtan, T.; Svítek, O.
2016-06-01
Explicit Robinson-Trautman solutions with an electromagnetic field satisfying nonlinear field equations are derived and analyzed. The solutions are generated from the spherically symmetric ones. In all studied cases the electromagnetic field singularity is removed while the gravitational one persists. The models resolving the curvature singularity in spherically symmetric spacetimes could not be generalized to the Robinson-Trautman geometry using the generating method developed in this paper, which indicates that the removal of a singularity in the associated spherically symmetric case might be just a consequence of high symmetry. We show that the obtained solutions are generally of algebraic type II and reduce to type D in spherical symmetry. Asymptotically they tend to the spherically symmetric case as well.
Inverse solutions for tilting orthogonal double prisms.
Li, Anhu; Ding, Ye; Bian, Yongming; Liu, Liren
2014-06-10
An analytical reverse solution and actual examples are given to show how to direct a laser beam from a pair of orthogonal prisms to given targets in free space. Considering the influences of double-prism structural parameters, a lookup table method to seek the numerical reverse solution of each prism's tilting angle is also proposed for steering the double-prism orientation to track a target position located in the near field. Some case studies, as well as a specified elliptical target trajectory scanned by the cam-based driving double prisms, exhibit the significant application values of the theoretical derivation. The analytic reverse and numerical solutions can be generalized to investigate the synthesis of scanning patterns and the controlling strategy of double-prism tilting motion, the potentials of which can be explored to perform the orientation and position tracking functions in applications of precision engineering fields. PMID:24921137
Phase Separation in Solutions of Monoclonal Antibodies
NASA Astrophysics Data System (ADS)
Benedek, George; Wang, Ying; Lomakin, Aleksey; Latypov, Ramil
2012-02-01
We report the observation of liquid-liquid phase separation (LLPS) in a solution of humanized monoclonal antibodies, IgG2, and the effects of human serum albumin, a major blood protein, on this phase separation. We find a significant reduction of phase separation temperature in the presence of albumin, and a preferential partitioning of the albumin into the antibody-rich phase. We provide a general thermodynamic analysis of the antibody-albumin mixture phase diagram and relate its features to the magnitude of the effective inter-protein interactions. Our analysis suggests that additives (HSA in this report), which have moderate attraction with antibody molecules, may be used to forestall undesirable protein condensation in antibody solutions. Our findings are relevant to understanding the stability of pharmaceutical solutions of antibodies and the mechanisms of cryoglobulinemia.
Electrochemical Removal Of Selenate From Aqueous Solutions
Baek, Kitae; Kasem, Naji; Ciblak, Ali; Vesper, Dorothy; Padilla, Ingrid; Alshawabkeh, Akram N.
2013-01-01
Removal of selenate from solution is investigated in batch electrochemical systems using reactive iron anodes and copper plate cathode in a bicarbonate medium. Iron anodes produce ferrous hydroxide, which is a major factor in the removal of selenate from solution. Iron anodes also generate a significant decrease in the oxidation-reduction potential (ORP) of the solution because it prevents generation of oxygen gas at the anode by electrolysis. The removal rates varied from 45.1 to 97.4%, depending on current density and selenate concentration. The transformation of selenate by the process is modeled based on a heterogeneous reaction coupled with electrochemical generation of ferrous and hydroxide. The rates are optimized at lower initial concentrations, higher electrical currents, and the presence of anions. Presence of dissolved oxygen does not cause any significant effects the removal of selenate. PMID:23378820
DNA nanopore translocation in glutamate solutions
NASA Astrophysics Data System (ADS)
Plesa, C.; van Loo, N.; Dekker, C.
2015-08-01
Nanopore experiments have traditionally been carried out with chloride-based solutions. Here we introduce silver/silver-glutamate-based electrochemistry as an alternative, and study the viscosity, conductivity, and nanopore translocation characteristics of potassium-, sodium-, and lithium-glutamate solutions. We show that it has a linear response at typical voltages and can be used to detect DNA translocations through a nanopore. The glutamate anion also acts as a redox-capable thickening agent, with high-viscosity solutions capable of slowing down the DNA translocation process by up to 11 times, with a corresponding 7 time reduction in signal. These results demonstrate that glutamate can replace chloride as the primary anion in nanopore resistive pulse sensing.
Solitonlike solutions in loop current eddies
NASA Technical Reports Server (NTRS)
Nakamoto, Shoichiro
1989-01-01
The application of the nonlinear quasi-geostrophic equations to an isolated eddy in the western continental slope region in the Gulf of Mexico is examined for a two-layer ocean model with bottom topography. In the linear limit, solutions are topographic nondispersive waves. Form-preserving solutions, or solitons, have been found. The solution is shown to be a limiting form for a nonlinear dispersive system propagating northward along the topographic waveguide in the western continental slope region in the Gulf of Mexico. Using satellite-tracked drifter data, a linear relationship is found between the amplitude of the deduced stream function of the eddy and its observed translational velocity over the continental slope, which supports the hypothesis that some mesoscale eddies interacting with the continental slope behave as solitons.
Homogeneous freezing nucleation of stratospheric solution droplets
NASA Technical Reports Server (NTRS)
Jensen, Eric J.; Toon, Owen B.; Hamill, Patrick
1991-01-01
The classical theory of homogeneous nucleation was used to calculate the freezing rate of sulfuric acid solution aerosols under stratospheric conditions. The freezing of stratospheric aerosols would be important for the nucleation of nitric acid trihydrate particles in the Arctic and Antarctic stratospheres. In addition, the rate of heterogeneous chemical reactions on stratospheric aerosols may be very sensitive to their state. The calculations indicate that homogeneous freezing nucleation of pure water ice in the stratospheric solution droplets would occur at temperatures below about 192 K. However, the physical properties of H2SO4 solution at such low temperatures are not well known, and it is possible that sulfuric acid aerosols will freeze out at temperatures ranging from about 180 to 195 K. It is also shown that the temperature at which the aerosols freeze is nearly independent of their size.
An address geocoding solution for Chinese cities
NASA Astrophysics Data System (ADS)
Zhang, Xuehu; Ma, Haoming; Li, Qi
2006-10-01
We introduce the challenges of address geocoding for Chinese cities and present a potential solution along with a prototype system that deal with these challenges by combining and extending current geocoding solutions developed for United States and Japan. The proposed solution starts by separating city addresses into "standard" addresses which meet a predefined address model and non-standard ones. The standard addresses are stored in a structured relational database in their normalized forms, while a selected portion of the non-standard addresses are stored as aliases to the standard addresses. An in-memory address index is then constructed from the address database and serves as the basis for real-time address matching. Test results were obtained from two trials conducted in the city Beijing. On average 80% matching rate were achieved. Possible improvements to the current design are also discussed.
RECOVERY OF PROTACTINIUM FROM AQUEOUS SOLUTIONS
Elson, R.E.
1959-07-14
The recovery of fluoride complexed protactinium from aqueous acidic solutions by solvent extraction is described. Generally the prccess of the invention com rises mixing an aqueous solution containing protactinium in a complexed form with an organic solvent which is specific for protactinium, such as diisopropyl carbinol, then decomposing the protactinium complex by adjusting the acidity of the aqueous solution to between 0-3 to 0-9 M in hydrogen ion concentration, and introducing a source of aluminum ions in sufficient quantity to establish a concentration of 0.5 to 1.2 M aluminum ion, whereupon decomposition of the protactinium fluoride complex takes place and the protactinium ion is taken up by the organic solvent phase.
Dynamics of water molecules in glucose solutions.
Talon, C.; Smith, L. J.; Brady, J. W.; Copley, J. R. D.; Price, D. L.; Saboungi, M. L.; Materials Science Division; Centre de Recherche sur la Matiyre Divisye; Cornell Univ.; NIST; Centre de Recherche sur les Matyriaux y Haute Tempyrature
2004-04-22
The effects of the solution of glucose molecules on the dynamics of solvent water have been studied by quasielastic neutron scattering (QENS) measurements on solutions of selectively deuterated glucose in natural water. The data are fitted to two Lorentzians ascribed to pure translational and mixed translational and rotational character, respectively. The addition of the glucose to the water causes a substantial slowing down, by a factor 10 for the translational diffusion and 3-4 for the rotational motion at the highest concentration studied, 1:11 C{sub 6}H{sub 12}O{sub 6}:H{sub 2}O. The values obtained for water diffusion constants are consistent with previous QENS and NMR experiments on monosaccharide solutions but an order of magnitude higher than those derived from a recent molecular dynamics simulation.
REdiii: a pipeline for automated structure solution.
Bohn, Markus Frederik; Schiffer, Celia A
2015-05-01
High-throughput crystallographic approaches require integrated software solutions to minimize the need for manual effort. REdiii is a system that allows fully automated crystallographic structure solution by integrating existing crystallographic software into an adaptive and partly autonomous workflow engine. The program can be initiated after collecting the first frame of diffraction data and is able to perform processing, molecular-replacement phasing, chain tracing, ligand fitting and refinement without further user intervention. Preset values for each software component allow efficient progress with high-quality data and known parameters. The adaptive workflow engine can determine whether some parameters require modifications and choose alternative software strategies in case the preconfigured solution is inadequate. This integrated pipeline is targeted at providing a comprehensive and efficient approach to screening for ligand-bound co-crystal structures while minimizing repetitiveness and allowing a high-throughput scientific discovery process. PMID:25945571
Theory for Surface Structure of Electrolyte Solutions.
NASA Astrophysics Data System (ADS)
Nichols, Albert Loyd, III
A theory is developed for the salt concentration profile and ion-ion correlations near surfaces of electrolyte solutions. We use the random phase approximation to study the primitive surface model employed by Onsager and Samaras, and others. In this model the chief technical complication is the correct treatment of image forces. We invent an exact rearrangement of the mathematical formulation of the problem which makes especially transparent the special case solutions (infinite dielectric constant mismatch) previously found. This reformulation guides an analytical solution for arbitrary dielectric constant mismatch between the two phases, subject to other assumptions adopted by previous workers. Similarly general results are derived for mixtures of ionic and dipolar solutes. These general results form the basis for extending our theoretical studies in several new directions. First, higher concentration corrections are investigated. It is shown that over an experimentally significant range of low concentrations for aqueous solutions the initial concentration correction to the Onsager-Samaras absorption has a negative definite sign. The theory, including concentration corrections, is compared to available computer simulation data, and close agreement is found for aqueous solutions below a few tenths molar. Second, the theory is developed to treat asymmetric electrolytes, and applied to ionic surfactants spread on water-hydrocarbon interfaces. Again, the theory accurately describes available experimental data. Third, the theory is broadened to acknowledge the solubility of the salt in both phases. It is found that this generalization changes the qualitative nature of the low concentration limiting law for the excess surface tension: the limiting behavior is changed from the (rho)ln(rho) dependence predicted by Onsager and Samaras to a more generally correct (rho)(' 1/2) dependence. Experimental data which might test this (rho)(' 1/2) behavior are not presently
REMOVAL OF CHLORIDE FROM AQUEOUS SOLUTIONS
Hyman, M.L.; Savolainen, J.E.
1960-01-01
A method is given for dissolving reactor fuel elements in which the uranium is associated with a relatively inert chromium-containing alloy such as stainless steel. An aqueous mixture of acids comprising 2 to 2.5 molar hydrochloric acid and 4 to 8 molar nitric acid is employed in dissolving the fuel element. In order io reduce corrosion in subsequent processing of the resulting solution, chloride values are removed from the solution by contacting it with concentrated nitric acid at an elevated temperature.
Cosmological Solutions of Emergent Noncommutative Gravity
Klammer, Daniela; Steinacker, Harold
2009-06-05
Matrix models of the Yang-Mills type lead to an emergent gravity theory, which does not require fine-tuning of a cosmological constant. We find cosmological solutions of the Friedmann-Robertson-Walker type. They generically have a big bounce, and an early inflationlike phase with graceful exit. The mechanism is purely geometrical; no ad hoc scalar fields are introduced. The solutions are stabilized through vacuum fluctuations and are thus compatible with quantum mechanics. This leads to a Milne-like universe after inflation, which appears to be in remarkably good agreement with observation and may provide an alternative to standard cosmology.
Cosmological solutions of emergent noncommutative gravity.
Klammer, Daniela; Steinacker, Harold
2009-06-01
Matrix models of the Yang-Mills type lead to an emergent gravity theory, which does not require fine-tuning of a cosmological constant. We find cosmological solutions of the Friedmann-Robertson-Walker type. They generically have a big bounce, and an early inflationlike phase with graceful exit. The mechanism is purely geometrical; no ad hoc scalar fields are introduced. The solutions are stabilized through vacuum fluctuations and are thus compatible with quantum mechanics. This leads to a Milne-like universe after inflation, which appears to be in remarkably good agreement with observation and may provide an alternative to standard cosmology. PMID:19658852
Solute partial molal volumes in supercritical fluids
Eckert, C.A.; Ziger, D.H.; Johnston, K.P.; Kim, S.
1986-06-05
A novel technique is described for the measurement of the partial molal volume at infinite dilution of solutes in supercritical fluids. Results are reported for five systems from 2/sup 0/C above the solvent critical temperature up to 15/sup 0/C above, at pressures from just above the critical pressure to 350 bars. The solute partial molal volumes are small and positive at high pressures, but very large and negative in the highly compressible near-critical region. The results are interpreted in terms of solvent structure and intermolecular forces.
SEPARATION OF INORGANIC SALTS FROM ORGANIC SOLUTIONS
Katzin, L.I.; Sullivan, J.C.
1958-06-24
A process is described for recovering the nitrates of uranium and plutonium from solution in oxygen-containing organic solvents such as ketones or ethers. The solution of such salts dissolved in an oxygen-containing organic compound is contacted with an ion exchange resin whereby sorption of the entire salt on the resin takes place and then the salt-depleted liquid and the resin are separated from each other. The reaction seems to be based on an anion formation of the entire salt by complexing with the anion of the resin. Strong base or quaternary ammonium type resins can be used successfully in this process.
Comments on lump solutions in SFT
NASA Astrophysics Data System (ADS)
Bonora, Loriano; Tolla, Driba D.
2016-04-01
We analyze a recently proposed scheme to construct analytic lump solutions in open SFT. We argue that in order for the scheme to be operative and to guarantee background independence it must be implemented in the same 2D conformal field theory in which SFT is formulated. We outline and discuss two different possible approaches. Next we reconsider an older proposal for analytic lump solutions and implement a few improvements. In the course of the analysis we formulate a distinction between regular and singular gauge transformations and advocate the necessity of defining a topology in the space of string fields.
Microscopic treatment of solute trapping and drag
NASA Astrophysics Data System (ADS)
Humadi, Harith; Hoyt, J. J.; Provatas, Nikolas
2016-01-01
The long wavelength limit of a recent microscopic phase-field crystal (PFC) theory of a binary alloy mixture is used to derive an analytical approximation for the segregation coefficient as a function of the interface velocity, and relate it to the two-point correlation function of the liquid and the thermodynamic properties of solid and liquid phases. Our results offer the first analytical derivation of solute segregation from a microscopic model, and support recent molecular dynamics and numerical PFC simulations. Our results also provide an independent framework, motivated from classical density functional theory, from which to elucidate the fundamental nature of solute drag, which is still highly contested in the literature.
Solution-Phase Processes of Macromolecular Crystallization
NASA Technical Reports Server (NTRS)
Pusey, Marc L.; Minamitani, Elizabeth Forsythe
2004-01-01
We have proposed, for the tetragonal form of chicken egg lysozyme, that solution phase assembly processes are needed to form the growth units for crystal nucleation and growth. The starting point for the self-association process is the monomeric protein, and the final crystallographic symmetry is defined by the initial dimerization interactions of the monomers and subsequent n-mers formed, which in turn are a function of the crystallization conditions. It has been suggested that multimeric proteins generally incorporate the underlying multimers symmetry into the final crystallographic symmetry. We posed the question of what happens to a protein that is known to grow as an n-mer when it is placed in solution conditions where it is monomeric. The trypsin-treated, or cut, form of the protein canavalin (CCAN) has been shown to nucleate and grow crystals as a trimer from neutral to slightly acidic solutions. Under these conditions the solution is composed almost wholly of trimers. The insoluble protein can be readily dissolved by weakly basic solution, which results in a solution that is monomeric. There are three possible outcomes to an attempt at crystallization of the protein under monomeric (high pH) conditions: 1) we will obtain the same crystals as under trimer conditions, but at different protein concentrations governed by the self association equilibria; 2) we will obtain crystals having a different symmetry, based upon a monomeric growth unit; 3) we will not obtain crystals. Obtaining the first result would be indicative that the solution-phase self-association process is critical to the crystal nucleation and growth process. The second result would be less clear, as it may also reflect a pH-dependent shift in the trimer-trimer molecular interactions. The third result, particularly for experiments in the transition pH's between trimeric and monomeric CCAN, would indicate that the monomer does not crystallize, and that solution phase self association is not part
Exact solutions for network rewiring models
NASA Astrophysics Data System (ADS)
Evans, T. S.
2007-03-01
Evolving networks with a constant number of edges may be modelled using a rewiring process. These models are used to describe many real-world processes including the evolution of cultural artifacts such as family names, the evolution of gene variations, and the popularity of strategies in simple econophysics models such as the minority game. The model is closely related to Urn models used for glasses, quantum gravity and wealth distributions. The full mean field equation for the degree distribution is found and its exact solution and generating solution are given.
Numerical methods for finding stationary gravitational solutions
NASA Astrophysics Data System (ADS)
Dias, Óscar J. C.; Santos, Jorge E.; Way, Benson
2016-07-01
The wide applications of higher dimensional gravity and gauge/gravity duality have fuelled the search for new stationary solutions of the Einstein equation (possibly coupled to matter). In this topical review, we explain the mathematical foundations and give a practical guide for the numerical solution of gravitational boundary value problems. We present these methods by way of example: resolving asymptotically flat black rings, singly spinning lumpy black holes in anti-de Sitter (AdS), and the Gregory–Laflamme zero modes of small rotating black holes in AdS{}5× {S}5. We also include several tools and tricks that have been useful throughout the literature.
Hydroxyanthraquinone dye solutions for radiation dosimetry.
Bedear El-Assy, N; Alian, A; Abdel Rahim, F; Roushdy, H
1982-06-01
An investigation has been carried out on the effect of gamma-radiation on the absorption spectra of aqueous solutions of the hydroxyanthraquinone dyes, alizarin and alizarin red S. Ionizing radiation at absorbed doses over the range 10(5)-3 x 10(6) rad brought about gradual bleaching of aerated (oxygenated) dye solutions. The radiolytic bleaching was enhanced through addition of hydrogen peroxide, as expected. A mechanism for the radiolytic reaction is proposed, based on chemical attack of the chromophore by radicals and radical ions as aqueous radiolysis products. Suggestions are made for possible radiation dosimetry by means of spectrophotometric analysis of the absorption spectra. PMID:7107037
Conformation of carboxylated schizophyllan in aqueous solution.
Yoshiba, Kazuto; Sato, Takahiro; Osumi, Takaaki; Ulset, Ann-Sissel T; Christensen, Bjørn E
2015-12-10
Carboxylated schizophyllan (sclerox) samples of different degrees of oxidation were molecularly characterized by size exclusion chromatography equipped with a multi-angle light scattering detector (SEC-MALS) in 0.10 M aqueous NaCl solution. The molar mass distribution obtained by SEC-MALS shows that sclerox of low degree of oxidation is dissolved mainly as the trimer, whereas the trimer and single chain coexist in solution of sclerox of high degree of oxidation. The trimer of sclerox is much more flexible than the fully ordered triple helix of the parent schizophyllan and easily dissociates into single chains upon heating. PMID:26428092
Colloidal solutions of organic conductive nanoparticles.
de Caro, Dominique; Souque, Matthieu; Faulmann, Christophe; Coppel, Yannick; Valade, Lydie; Fraxedas, Jordi; Vendier, Olivier; Courtade, Frédéric
2013-07-16
Although molecular metals have been known for decades, their insolubility, low vapor pressure, and synthesis routes have prevented them from being integrated into electronic devices. We have prepared stable colloidal solutions of the organic metal TTF-TCNQ that overcome such difficulties. The solutions contain well-dispersed nanoparticles stabilized by long alkyl chain amines. They afford soluble powders by evaporation and homogeneous thin films by drop-casting. Powders and films show room temperature conductivities in the 0.01-0.1 S cm(-1) range. PMID:23772890
Quantum solution to the Byzantine agreement problem.
Fitzi, M; Gisin, N; Maurer, U
2001-11-19
We present a solution to an old problem in distributed computing. In its simplest form, a sender has to broadcast some information to two receivers, but they have access only to pairwise communication channels. Unlike quantum key distribution, here the goal is not secrecy but agreement, and the adversary (one of the receivers or the sender himself) is not outside but inside the game. Using only classical channels this problem is provably impossible. The solution uses pairwise quantum channels and entangled qutrits. PMID:11736379
Generalization of the Randall-Sundrum solution
NASA Astrophysics Data System (ADS)
Kisselev, A. V.
2016-08-01
The generalization of the Randall-Sundrum solution for the warp factor exp [ σ (y) ] in the scenario with one extra coordinate y, non-factorizable space-time geometry and two branes is obtained. It is shown that the function obtained σ (y) is symmetric with respect to an interchange of two branes. It also obeys the orbifold symmetry y → - y and explicitly reproduces jumps of its derivative on both branes. This solution is defined by the Einstein-Hilbert's equations up to a constant C. It is demonstrated that different values of C result in theories with quite different spectra of the Kaluza-Klein gravitons.