bluuebunny/crossref_metadata_2025_split huggingface dataset:
Can Humans Being Clerks make Clerks be Human? – Exploring the Fundamental Difference between UbiComp and WearComp (Können Menschen, die sich wie Angestellte benehmen, Angestellte zu menschlichem Verhalten bewegen? Zum fundamentalen Unterschied zwischen UbiComp und WearComp)
Authors: Mann Steve 
Published: August 2006

In this paper it is argued that pervasive ubiquitous computing and surveillance tends to give rise to a dehumanizing society of automatons, whereas wearable devices owned, operated, and controlled by individuals have the potential to counteract this trend.
Within the context of reversing the dehumanizing aspects of ubicomp, through the use of wearable technology, two fundamental axes are defined and described:
– Incidentalism (Nonselectivity), which is the degree to which the wearer´s action appears to not be intentionally directed at a specific individual; and
– Freewill (Existentiality), which is the degree to which an action appears to originate from the wearer´s own mind, without outside influence or duty.
The primary action explored is that of picture taking in establishments where taking pictures is prohibited. The hypothesis is that an otherwise unacceptable picture taking activity is acceptable in direct proportion to the Incidentalist axis and in inverse proportion to Freewill axis. An extensive lifelong series of experiments conducted in several different countries around the world, in which the author was wearing photographic computers for more than twenty years, is reported.
Lernerorientiertes Produktmodell für Web Based Training in den Ingenieurwissenschaften (Learner-Oriented Product Model for Web Based Training in the Engineering Sciences)
Authors: Thißen Dirk , Vogel-Heuser Birgit 
Published: August 2006

Moderne Informations- und Kommunikationstechnologien ermöglichen zeit- und ortsunabhängige Qualifizierungsformen, die als Web Based Training (WBT) bezeichnet werden. Die Entwicklung von WBT reduziert sich in vielen Fällen auf eine durch Medienbausteine (Animation, Audio, usw. ) angereicherte 1:1-Übersetzung der schriftlichen Lehrmaterialien. Dabei wird übersehen, dass die Potenziale von WBT nicht automatisch realisiert werden, sondern die didaktische Konzeption über die lernförderliche Qualität des WBT entscheidet [19; 20].
In diesem Artikel wird ein didaktisch fundiertes Produktmodell für WBT in den Ingenieurwissenschaften vorgestellt. Das Produktmodell unterstützt Dozenten und Lehrer in den Ingenieurwissenschaften, die Potenziale von WBT nutzbar zu machen. Das Produktmodell wurde als Prototyp realisiert, der durch Integration der fachspezifischen Lernangebote effizient zu einem WBT ausgebaut werden kann. Produktmodell und Prototyp bilden die Grundlage für einen neuartigen Entwicklungsprozess, bei dem sich Ingenieure weitestgehend auf ihre Fachlichkeit konzentrieren können.
Der Benutzer im User Interface-Gestaltungsprozess (The User in the UI Design Process for Consumer Products)
Authors: Böcker Martin , Schneider-Hufschmidt Matthias 
Published: August 2006

Vielen Entwicklern von User Interfaces sind die Bedürfnisse, Anforderungen und Vorlieben der späteren Benutzer von Consumer-Produkten weitgehend unbekannt. Das Ergebnis ihrer Bemühungen sind Produkte, deren Funktionalität von den Benutzern nicht ausgenützt wird, weil sie entweder für diese Benutzer irrelevant oder in der Handhabung so komplex sind, dass Sie von den späteren Kunden nicht verstanden werden.
Dabei ist es durchaus möglich, spätere Endkunden in die Gestaltungsprozesse für Benutzungsoberflächen dieser Produkte einzubinden. Zu den erfolgversprechenden Maßnahmen gehören primär Fokusgruppen-Analysen zur Erhebung von Nutzeranforderungen und Usability-Tests mit potenziellen Kunden, in denen während des gesamten Entwurfsprozesses Handhabungskonzepte, Gestaltungsalternativen und die entstehenden Produkte auf Akzeptanz und Nutzbarkeit getestet werden.
Reconstructing the Complete 3D Shape of Faces from Partial Information (Rekonstruktion der dreidimensionalen Form von Gesichtern aus partieller Information)
Authors: Blanz Volker , Vetter Thomas 
Published: August 2006

Based on the assumption that a class of objects or data can be represented as a vector space spanned by a set of examples, we present a general method to estimate vector components of a novel vector, given only a subset of its dimensions.
We apply this method to recover 3D shape of human faces from 2D image positions of a small number of feature points. The application demonstrates two aspects of the estimation of novel vector components: (1) From 2D image positions, we estimate 3D coordinates, and (2) from a small set of points, we obtain vertex positions of a high-resolution surface mesh. We provide an evaluation of the technique on laser scans of faces, and present an example of 3D shape reconstruction from a photograph.
Our technique involves a tradeoff between reconstruction of the given measurements, and plausibility of the result. This is achieved in a Bayesian approach, and with a statistical analysis of the examples.
Fast and Accurate Integration of Vector Fields in Unstructured Grids (Schnelles exaktes Integrationsverfahren für Vektorfelder auf unstrukturierten Gittern )
Authors: Reck Frank , Greiner Günther 
Published: August 2006

Particle tracing is a widely used method to analyze and interpret results of a flow simulation. In addition, it is a preliminary step for more advanced techniques of flow visualization, e.g. line integral convolution.
For interactive exploration of large data sets, a very efficient and reliable particle tracing method is needed. For data on unstructured grids and data sizes, as they appear in the simulation of wind channel experiments (e.g. automative industry) and flight simulation (e.g. aircraft industry), the traditional approach, based on numerical integration methods of ordinary differential equations does not allow sufficiently accurate path calculation at the speed required for interactive use.
Traditional integration techniques require small stepsizes in order to achieve sufficient accuracy. T his results in many cell search operations, which means especially for unstructured grids a bottleneck of the whole procedure.
In [5] Nielson and Jung have proposed a new method, called further on locally exact method, which gives sufficient accuracy and traverses each cell in a single step. In this note we extend the approach of Nielson and Jung in such a way that it can be performed in real time. This will be achieved by a sophisticated preprocessing, which allows a fast execution of the locally exact integration method, interactive particle tracing in large data sets can be done. We describe the procedure, compare it with Nielson´s original approach, as well as with the traditional method based on numerical integration and report on the performance of the different methods.
The reduction of plutonium and neptunium ions by acetaldoxime in nitric acid
Authors: Koltunov V. S. , Taylor Robin J. , Baranov S.M. , Mezhov E.A. , Pastuschak V.G. , May I. 
Published: August 2006

The rate equations for the reduction of Np(V), Np(VI) and Pu(IV) ions by acetaldoxime in nitric acid have been determined as:-d[Np(V)]/dt = k26[Np(V)][CH3CHNOH][HNO3]1.2- d[Np(VI)/dt = k19[Np(VI)][CH3CHNOH]/[HNO3]- d[Pu(IV)/dt = k6[Pu(IV)]2[CH3CHNOH]1.1/[Pu(III)][HNO3]2.2where respectively: k26= (9.2±0.2)×10-4l2.2mol-2.2min-1at 60° C; k19= 254±10 min-1at 26.0° C; k6= 25.3±1.9 mol1.1l-1.1min-1at 19.5°C. The activation energies were found to be: E19= 62.6±2.6 kJmol-1and E26= 87.7±9.8 kJmol-1. Np(V) was generally found to be stable for long periods in nearly all the kinetic experiments and the reduction of Np(V) to Np(IV) could only be studied at elevated temperatures and reactant concentrations.Possible reaction mechanisms for the reduction of Np(VI) and Pu(IV) have been suggested; proceeding, in both cases, via the hydrolysis product and an intermediate CH3CHN¤O radical. Simple solvent extraction experiments have shown that Np(VI) and Pu(IV) can be reductively stripped from 30% TBP/n-dodecane in the presence of U(VI).
The oxidation of hydroxylamine by nitric and nitrous acids in the presence of technetium (VII)
Authors: Koltunov V. S. , Taylor Robin J. , Gomonova T.V. , Savilova O. A. , Zhuravleva G.I. , Denniss I.S. 
Published: August 2006

The oxidation of hydroxylamine by nitric acid in the presence of technetium ions at temperatures above ~60°C is an autocatalytic process comprising an induction period and then a catalysed reaction involving HNO2, which has accumulated in the solution. Tc ions have no appreciable effect on the reaction rate, which is governed only by the nitric and nitrous acid oxidation reactions of hydroxylamine, but the presence of Tc ions does extend the initial induction period. The rate of hydroxylamine oxidation by HNO3in the presence of HNO2, that is, after the induction period, was found to be:-d[NH3OH+]/dt = k[NH3OH+][HNO2][HNO3]3.5where k = 120±10 l4.5mol-4.5min-1at T = 80°C, μ = 2 and [H+] ≤ 2 M. Under these conditions, the reaction apparently has a high activation energy of 160-180 kJ mol-1. At low temperatures (20-40°C) hydroxylamine is effectively stable in solutions of HNO3up to concentrations of ~2 M, whether or not Tc(VII) ions are present. Tc(V) was also observed to form at least one complex on reduction with excess hydroxylamine with an absorption maximum between 467 and 480 nm dependent on the solution acidity.
Experimental determination and chemical modelling of radiolytic processes at the spent fuel/water interface
Authors: Bruno J. , Cera E. , Eklund U.-B. , Eriksen T. , Grivé M. , Spahiu Kastriot 
Published: August 2006

The spent fuel matrix constitutes a dynamic redox system, due to the time-dependent generation of oxidants and reductants at the spent fuel/water interface by alpha, beta and gamma radiolysis. In this context it is critical to understand the main processes and mechanisms that control the radiolytic production of redox components at this interface and their impact on the stability of the UO2 matrix and in radionuclide release.
In order to achieve this, a series of carefully controlled experiments have been carried out in order to determine the time dependence of the radiolytic H2, O2 and H2O2 production and radionuclide release (U, Pu, Np, Tc, Mo, Sr and Cs). These tests have been performed by using PWR Ringhals spent fuel fragments in contact with 10 mM NaHCO3 solutions in an initially anoxic and closed system.
The results of these experiments indicate quite a consistent and reproducible behaviour of the radiolytically generated reductants and oxidants. The results indicate that it is possible to define an equilibrium redox potential for the main redox pairs in the bulk system and that the experimentally determined radionuclide release can be rationalised in terms of the system redox potential.
Thermodynamic data for the solubility of tin(IV) in aqueous cementitious environments
Authors: Lothenbach B. , Ochs Michael , Hager D. 
Published: August 2006

The solubility of Sn(IV) in cementitious systems is directly related to the presence of dissolved Ca. In the presence of typical Ca concentrations, solid Ca[Sn(OH)6](s) is precipitated, resulting in dissolved tin(IV) concentrations that are about four to six orders of magnitude lower than observed in alkaline, Ca-free systems. From different experiments carried out in initially oversaturated and undersaturated solutions, solubility products have been evaluated.
A constant of 109.85 at I=0 has been derived for the formation of fresh Ca[Sn(OH)6](precip) according to the reaction Ca2++{Sn(OH)6
2- ↔ Ca[Sn(OH)6](s). A constant of 1010.93 has been derived in undersaturation experiments for the equilibrium with crystalline Ca[Sn(OH)6](cr).
Solution coordination chemistry of uranium in the binary UO22+-SO42-and the ternary UO22+-SO42--OH-system
Authors: Moll H. , Reich T. , Hennig C. , Roßberg A. , Szabó Z. , Grenthe I. 
Published: August 2006

The structure and reaction dynamics in the systems UO22+-SO42-and UO22+-SO42--OH-were investigated using EXAFS and17O-NMR spectroscopy. Uranium LIIIedge EXAFS indicated a bidentate coordination mode of sulfate to uranyl. In solution, this is characterized by an U-S distance of 3.11 Å. Approximately 5 oxygen atoms were observed in the equatorial plane at 2.39-2.43 Å. The kinetics in the binary uranyl sulfate system can be described by four dominant exchange reactions: (1) UO22++ SO42-⇔ UO2SO4(k1), (2) U*O22++ UO2SO4⇔ U*O2SO4+ UO22+(k2), (3) UO22++ UO2(SO4)22-⇔ 2 UO2SO4(k3), and (4) UO2SO4+ SO42-⇔ UO2(SO4)22-(k4). These reactions have rate constants indicating that the exchange is not of the simple Eigen-Wilkins type.Ternary uranyl sulfate hydroxide species were characterized by their17O chemical shift and by potentiometry. There are no separate signals for the possible isomers of the ternary species indicating that they are in fast exchange with each other.
An electrostatic approach for the prediction of actinide complexation constants with inorganic ligands-application to carbonate complexes
Authors: Neck Volker , Kim J. I. 
Published: August 2006

A new semi-empirical approach is presented for the prediction of actinide complexation constants with inorganic ligands and applied to mononuclear carbonate complexes. The approach is based on an energy term describing the inter-ligand electrostatic repulsion. For a given metal ion M and ligand L, the formation constants log β°nof the complexes MLnare related by:log β°n= n log β°1-repEL(MLn) / RT ln 10The electrostatic ligand repulsion termrepELis derived from the charge and inter-distance of ligands involved in a given complex and their angular distribution. Semi-empirical parameters are required to describe the effective electrostatic shielding between complexing ligand ions with the metal ion and hydration water molecules between them. These shielding coefficients are specific for the ligands, but independent of the actinide ion and its oxidation state. The shielding coefficients for carbonate ligands are determined from the known formation constants of Am(III) and Cm(III) carbonate complexes, and then used to calculate carbonate complexation constants for other actinides of different oxidation states. Excellent agreement is found between the calculated and experimental values for Np(V), U(VI), Pu(VI), and even for the transition metals Fe(II) and Cu(II). Based on known constants log β°4and log β°5for U(IV) and Pu(IV), the unknown constants log β°1, log β°2and log β°3are estimated.
Determination and uncertainties of radioelement solubility limits to be used by SKB in the SR 97’ performance assessment exercise
Authors: Bruno J. , Cera E. , Grivé M. , de Pablo Joan , Sellin P. , Duro L. 
Published: August 2006

The Swedish Fuel and Waste Management Co, SKB, is at present preparing a Performance Assessment (PA) exercise of its HLNW repository concept. The determination of solubility limits of the main radioelements contained in the spent nuclear fuel is a necessary work to understand their potential migration in both the near and far fields.
The calculated solubilities are compared to experimental data from relevant spent nuclear fuel dissolution tests and field observations from natural systems, particularly Natural Analogue study sites. This work discusses the main uncertainties associated to the calculated solubilities, particularly those related to the variability of groundwater composition, redox conditions and temperature of the system.
The results of the sensivity analysis indicate that although the solubility of some radioelements, such as Th, is not dramatically affected by the uncertainty in the determination of the physico-chemical parameters mentioned above, most of the elements are strongly influenced by this variability, specially Am, U, Np, Pu and Tc.
Uranyl(VI) carbonate complex formation: Validation of the Ca2UO2(CO3)3(aq.) species
Authors: Bernhard G. , Geipel Gerhard , Reich T. , Brendler V. , Amayri S. , Nitsche Heino 
Published: August 2006

We recently discovered a neutral dicalcium uranyl tricarbonate complex, Ca2UO2(CO3)3(aq.), in uranium mining related waters [1]. We are now reporting a further validation of the stoichiometry and the formation constant of this complex using two analytical approaches with time-resolved laser-induced fluorescence spectroscopy (TRLFS) species detection: i) titration of a non-fluorescent uranyl tricarbonate complex solution with calcium ions, and quantitative determination of the produced fluorescent calcium complex via TRLFS; and ii) variation of the calcium concentration in the complex by competitive calcium complexation with EDTA4-.Slope analysis of the log (fluorescence intensity)versuslog[Ca2+] with both methods have shown that two calcium ions are bound to form the complex Ca2UO2(CO3)3(aq.). The formation constants determined from the two independent methods are: i) logβ°213=30.45±0.35 and ii) logβ°213=30.77±0.25.A bathochrome shift of 0.35 nm between the UO2(CO3)34-complex and the Ca2UO2(CO3)3(aq.) complex is observed in the laser-induced photoacoustic spectrum (LIPAS), giving additional evidence for the formation of the calcium uranyl carbonate complex.EXAFS spectra at the LIIand LIII-edges of uranium in uranyl carbonate solutions with and without calcium do not differ significantly. A somewhat better fit to the EXAFS of the Ca2UO2(CO3)3(aq.) complex is obtained by including the U-Ca shell. From the similarities between the EXAFS of the Ca2UO2(CO3)3(aq.) species in solution and the natural mineral liebigite, we conclude that the calcium atoms are likely to be in the same positions both in the solution complex and in the solid.This complex influences considerably the speciation of uranium in the pH region from 6 to 10 in calcium-rich uranium-mining-related waters.
The migration of radionuclides237Np,238Pu and241Am in a weak loess aquifer: A field column experiment
Authors: Chunli L. , Zhiming W. , Shushen Li , Yuee Y. , Hong J. , Bing Li , Ling J. , Ling W. , Dan L. , Zhongde Du , Zhiming G. 
Published: August 2006

The migration of radionuclides237Np,238Pu and241Am in a weak loess aquifer were investigated in-situ with a bisectional experimental column. The experimental column was constructed by connecting 2 undisturbed aquifer medium columns together and inserted into the aquifer horizontally through holes pre-prepared in the wall of a vertical experimental shaft in an Underground Research Facility at the CIRP´s field test site. Quartz containing radionuclides3H,237Np,238Pu and241Am was introduced as a point source at the center of the experimental column. Outflow water of the experimental column was collected and3H in the outflow was determined for calculating the water flow velocity through the experimental column. The experimental column was cut into slices of 0.3 cm long and the radioactivity of237Np,238Pu and241Am in the sliced soil samples was analyzed when the experiment was completed.The water flow velocity in the experimental column was calculated as 1.15±0.05 cm/d. The activity distribution of237Np,238Pu and241Am in the experimental column indicate that each radionuclide has a very strong activity distribution region adjacent to the source introduction point and decreases abruptly as the distance increases. In addition there are other secondary activity distribution regions with different strength and widths. The calculated apparent distribution coefficients of the main specie of these radionuclides is (8.90±1.51)×102ml/g for237Np, (9.48±1.61)×102ml/g for238Pu and (9.79±1.66)×102ml/g for241Am.
Investigation of separation/purification methodologies for the determination of 232U and 236Pu in solution of spent nuclear fuels by α-spectrometry
Authors: Solatie D. , Carbol P. , Peerani P. , Betti M. 
Published: August 2006

A methodology based on the use of several separation/purification steps exploiting TOPO, Dowex anion exchanger and UTEVA for attaining U and Pu fractions for α-spectrometry measurements is presented. The methodology is applied to the determination of the concentration of 236Pu and 232U in a normal burn-up fuel (30 GWd/t) and in a high burn-up fuel (50 GWd/t). The results are compared with those from the calculations performed with the ORIGEN code.
After 2 years cooling time, the amount of 232U was measured to be 4.9×10-10 g/g UO2 in the 30 GWd/t burn-up fuel sample and 1.5×-9 g/g UO2 in the high burn-up fuel sample. The amount of 236Pu after the same cooling time was found to be 4.2×10-10 and 1.2×-9 g/g UO2 in the two samples, respectively. Comparison of the experimental concentrations of 232U and 236Pu with the computed ones shows that the code overestimates the amounts of 232U and 236Pu formed in the reactor.
The inventory of the major U and Pu are also determined by radiometric methods. The results are in agreement with those from isotopic dilution mass spectrometry.
The preparation and decomposition of methylhydrazine oxalate and its application as cleaning extractant
Authors: Yu D. , Jingxin H. , Yuxing Y. 
Published: August 2006

The preparation, stability and decomposition of methylhydrazine oxalate (MHOX) were investigated. White needles of MHOX were prepared. The molecular formula of MHOX is (CH3N2H4)2C2O4. The aqueous solution of MHOX is stable at ambient temperature.
The kinetics of redox reaction between oxalic acid and H2O2 used as an oxidant was studied. The kinetic rate equation is as follows
-d[Ox]/dt = k [Ox][H2O2][H+]0.34.
The kinetics of redox reaction between methylhydrazine and H2O2 was also studied. The rate of decomposition of methylhydrazine is higher than that of oxalic acid. The decomposition reaction is given as follows:
CH3N2H3+H2O2 →N2+CH4+2H2O .
The proposed kinetic rate equation is as follows:
-d[CH3N2H3]/dt = k[CH3N2H3][H2O2].
The rate of decomposition of MHOX with H2O2 depends mainly on that of oxalic acid.
Experiments show that the washing efficiency of uranium from 30% TBP-kerosene (OK) used with MHOX is the same as that with Na2CO3. The washing efficiency of Pu and Am with MHOX is greater than that with Na2CO3.
Ereignisgesteuerte Wartung von pH-Messeinrichtungen (pH-Measurement with Condition-Based Maintenance-Request)
Authors: Melzer W. , Lauer C. , Stieler S. 
Published: August 2006

In diesem Beitrag werden Möglichkeiten der Reduktion von Inspektions- und Wartungskosten bei inline eingesetzten pH-Messungen erörtert. Nach Einführung in die Thematik wird eine neue Methode der pH-Messung mit Doppelmembran-Glasmessketten vorgestellt, die eine Messung und Kompensation der Sensorsteilheit gestattet, ohne dass der Sensor aus der Messlösung genommen bzw. Puffern ausgesetzt werden muss. Durch Beobachtung der so fortlaufend bestimmten Steilheit, aber auch des auf verschiedene Weise gewonnenen pH-Messwertes, lässt sich weitgehend der Abnutzungsvorrat bzw. die Funktionsfähigkeit der Messstelle bewerten. Wartungs- bzw. Instandsetzungsmaßnahmen lassen sich so ereignisgesteuert durchführen. Der Inspektions- und Wartungsaufwand wird damit reduziert.
Besondere Aufmerksamkeit wird der Frage der Signalbildung von Wartungsbedarf und Geräteausfall gewidmet. Erste Erfahrungen beim Betriebseinsatz von Doppelmembran-Glasmessketten haben gezeigt, dass auch die Bezugselektrode überwacht werden muss, und dass beim Einsatz solcher Systeme mit hohen Einsparungen beim Instandhaltungsaufwand zu rechnen ist.