bluuebunny/crossref_metadata_2025_split huggingface dataset:
Template‐Free Fabrication and Enhanced Photocatalytic Activity of Hierarchical Macro‐/Mesoporous Titania
Authors: Yu J. G. , Su Y. R. , Cheng B. 
Published: July 2007

AbstractHierarchical macro‐/mesoporous titania is prepared without the addition of templates or auxiliary additives at room temperature by the simple dropwise addition of tetrabutyl titanate to pure water, and then calcined at various temperatures. The products are characterized by X‐ray diffraction, N2‐adsorption–desorption analysis, scanning electron microscopy, and the corresponding photocatalytic activity is evaluated by measuring the photocatalytic oxidation of acetone in air. The results reveal that hierarchical macro‐/mesoporous structures of titania can spontaneously form by self‐assembly in alkoxide–water solutions in the absence of organic templates or auxiliary additives. The calcination temperature has a strong effect on the structures and photocatalytic activity of the prepared titania. At 300 °C, the calcined sample shows the highest photocatalytic activity. At 400 and 500 °C, the photocatalytic activity slightly decreases. When the calcination temperature is higher than 500 °C, the photocatalytic activity greatly decreases because of the destruction of the hierarchical macro‐/mesoporous structure of the titania and the drastic decrease of specific surface area. The hierarchically macro‐/mesostructured titania network with open and accessible pores is well‐preserved after calcination at 500 °C, indicating especially high thermal stability. The macroporous channel structures are even preserved after calcination at 800 °C. This hierarchical macro‐/mesostructured titania is significant because of its potential applications in photocatalysis, catalysis, solar‐cell, separation, and purification processes.
Layered Titanate Nanosheets Intercalated with Myoglobin for Direct Electrochemistry
Authors: Zhang L. , Zhang Q. , Li J. 
Published: July 2007

AbstractThe application of nanolayered inorganic materials as supports for immobilizing biomolecules has attracted attention because the host structures not only have “flexible pores” to adapt to the size of the biomolecule guests but they also protect the immobilized biomolecules from disturbances created by environmental variations. In this paper, layered titanate sheets (TNSs) were used as support matrixes for immobilizing myoglobin (Mb) to fabricate protein electrodes suitable for studying the direct electron transfer between the redox centers of proteins and the electrode and establish an example of a mediator‐free (third‐generation) biosensor. The uniform, porous morphology and ordered structure of the protein electrode were characterized by scanning electron microscopy, high‐resolution transmission electron microscopy, and X‐ray diffraction. The native structure of the intercalated Mb was maintained in the TNSs, and its behavior was characterized by UV‐vis and Fourier‐transform IR spectroscopy. Immobilized Mb in TNS films showed a fast direct electron transfer for the Mb–FeIII/FeII redox couple. Based on the direct electron transfer of the immobilized Mb, the protein electrode exhibited excellent catalytic performance for H2O2. Furthermore, in order to improve the stability of immobilized Mb in the TNS films, the thermal stability of the protein electrode and its electrochemical catalytic reduction of H2O2 in a low pH environment were discussed.
Reduktionswirkung der Zuckerarten und Zuckerzerfall
Authors: Fischler F. , Täufel K. , Souci S. W. 
Published: July 2007

AbstractAn Hand einer Zusammenstellung der zum Nachweis und zur quantitativen Bestimmung reduzierender Zuckerarten gebräuchlichen Reagenzien sowie auf der Grundlage eigener Untersuchungen wird der Schluß gezogen, daß die reduzierenden Eigenschaften der Zuckerarten in alkalischer Lösung nicht der ungespaltenen Molekel zukommen, sondern daß primär eine Aufspaltung der Hexosemoleküle unter Einfluß von Hydroxylionen in 3‐Kohlenstoffketten erfolgt, die ihrerseits Träger der Reduktionswirkung sind. Diese Schlußfolgerungen machen den nichtstöchiometrischen Verlauf der Reduktion im alkalischen Medium verständlich. Sie stehen andererseits in Übereinstimmung mit dem biologischen Verhalten des Traubenzuckers.
Über die Herstellung von Xylenolen und Äthylphenolen aus technischem Abfallxylidin bzw. Benzol
Authors: Brückner Horst 
Published: July 2007

AbstractTrennung eines technischen Xylidingemisches. Darstellung der Xylenole aus den entsprechenden Xylidinen. Synthese von Äthylbenzol aus Benzol und Äthylen. Darstellung der Äthylphenole.
Die neue Theorie Einsteins über die Verschmelzung von Gravitation und Elektrizität
Authors: Reichenbach Hans 
Published: July 2007

AbstractInhalt: Die neue Theorie Einsteins geht auf die Weyl‐Eddingtonsche Verallgemeinerung des Riemannschen Raumes zurück, welche in ihren geometrischen Grundzügen geschildert wird. Durch die Zusammenfassung von Gravitation und Elektrizität in ein einheitliches Feld wird eine physikalische Verkettung beider behauptet, die in ihren Folgen und ihrer Wirklichkeitsgeltung jedoch noch nicht zu übersehen ist.
Fortschritte in der Photographie in den letzten 10 Jahren
Authors: Eggert J. , Mediger H. 
Published: July 2007

AbstractInhalt: Herstellung von Silbersalzemulsionen. — Optische Sensibilisierung. — Prüfungs‐ und Analysenmethoden. — Sensitometrie und Messungen an photographischen Schichten. — Prüfung von Blitzlichtmaterialien. — Lichtempfindliche Schichten ohne Silbersalze. — Trocknen photographischer Schichten. — Photographische Schichtträger.
Zerlegung der Koksofengase und Ausnützung ihrer Einzelbestandteile
Authors: Bronn J. 
Published: July 2007

AbstractInhalt : Änderung der Zusammensetzung der Koksofengase mit fortschreitender Gärung; durchschnittliche Zusammensetzung der Koksofengase und das Verhalten der Einzelbestandteile bei tiefen Temperaturen. Starke Streuung der Verflüssigungstemperaturen, hingegen sehr tiefe Erstarrungstemperaturen der einzelnen Gasarten; die mit der Linde schen Apparatur bis jetzt erreichten Ergebnisse in der Gewinnung der Einzelbestandteile. Bestrebungen, neben dem Wasserstoff (für die Ammoniaksynthese, Hydrierung, Fetthärtung) auch Äthylen und Methan ihren spezifischen Eigenschaften gemäß zu verwenden. (Polymerisation zu Ölen, Crackung; Verwendung als Triebstoff).
Physikalische Prüfungen an Pigmenten
Authors: Schmid F. 
Published: July 2007

AbstractIm Anschluß an die Erörterungen der wissenschaftlichen Grundlagen für die Bestimmung der Helligkeit, des Deckvermögens und des Färbevermögens werden Verbesserungen an den bisherigen Methoden bzw. neue Verfahren zur Bestimmung dieser drei wichtigen farbtechnischen Kennzahlen beschrieben.
A simple bandwidth management scheme for multiservice ATM networks
Authors: Bianchi Giuseppe , Trecordi Vittorio 
Published: July 2007

AbstractIn this paper we outline a simple strategy to manage bandwidth allocation and congestion control and to guarantee service requirements in a multiservice ATM (asynchronous transfer mode) network. We propose a network architecture based on a core network, making available a limited number of quality of service profiles, and an access network, made of edge adapters in charge to match the user's requirements with the network's available quality of service profiles and to shape input traffic to achieve high network throughput. The connection admission rule is presented, and edge adapter architecture and design examples are given. The effectiveness of the scheme is demonstrated by numerical results which report the network utilization performance when the proposed core network policies and edge adapter design apply.
Temporal placement control of video frames in ATM networks
Authors: Lee Duan‐Shin , Sengupta Bhaskar 
Published: July 2007

AbstractIn this paper, we propose a new method of traffic smoothing for frames of different video sources. We assume that each video source transmits frames at fixed intervals and that the network is free to decide the relative temporal spacing of video frames from different sources. This means that the time at which a given source begins to transmit its first frame is under the control of the network; however, after that, all frames from this source are transmitted at fixed intervals. We now address two questions. What are some reasonable policies for spacing the frames of video sources? What is the performance advantage of doing this? We propose three control policies (two heuristic and one based on an optimization problem via some Fourier analysis). These are compared against the case in which the video frames from different sources are randomly distributed (i.e. no control is exercised). We show that significant performance advantages accrue if one controls the temporal placement of the video frames from different sources.
Performance evaluation of integrated services interworking: The ATM‐DQDB case
Authors: Venieris I. S. , Tsiotsios E. N. , Angelopoulos J. D. 
Published: July 2007

AbstractPerformance studies on LAN/MAN‐BISDN interworking have mainly focused on the requirements of isochronous and connectionless services. In this paper we extend performance results to cover also the case of non‐isochronous connection oriented (CO) services supported by the queued arbitrated (QA) mode of access of the DQDB protocol. Using this case we stress the more general issue of service integration impact on the interworking unit (IWU) architecture design in terms of protocol stacks and expected performance. We herein evaluate the performance of IWU architectures tailored to relay information in the lowest possible layer while implementing several service priority schemes and buffer management policies towards QoS objectives. The conditions under which the IWU design is efficient regarding performance, protocol complexity and implementation cost in this integrated services environment are identified.
Optimal channel assignment in cellular networks
Authors: Rouskas Angelos N. , Kazantzakis Michael G. , Anagnostou Miltiades E. 
Published: July 2007

AbstractIn this paper, we consider the problem of assigning frequencies to mobile terminals in a cellular network. We show that an optimal solution can be obtained by solving a sequence of alternating linear and quadratic maximization programming problems. We address co‐channel constraints and adopt as an objective function the maximization of potentially established calls. Our algorithm is fairly general, and does not depend on any special network structure. This study indicates that mathematical programming can be used as an efficient technique for solving the aforementioned problem.
Intersection functions of shortest paths in a nondirected graph
Authors: Kishi Genya , Sasakis Isao 
Published: July 2007

AbstractAn essential means to upgrade network reliability is to prepare several substitutable paths between two vertices. We idealize the substitutability in a narrow sense. We will study the mutual relationship between a bundle of shortest paths between any two vertices, and a third vertex from the viewpoint of path multiplicity in case there are some shortest paths between any two vertices. Initially, we will extend a concept of the cutting number, which represents a mutual relationship between a path of any pair of vertices and a third vertex in a tree graph. Then we will generalize it as the intersection function in any graph. Afterward, we will introduce conditions of decreasing this intersection function by inserting edges into the graph. Further, we will demonstrate the main features of this intersection function based upon the conditions. They can provide a new definition of the center in graphs with regard to reliability. We will extend the concept of the intersection function to an edge intersection function.
Evaluation of dynamic steps of path hunting in space‐division multistage switching networks
Authors: Ogino Nagao , Saito Tadao , Inose Hiroshi 
Published: July 2007

AbstractSpace‐division electronic switching systems require the use of a swtiching network with the fewest possible crosspoints, since switching elements are expensive. Therefore, the switching capacity must be limited to the extent that a switching network should be structured in a multistaged manner if the switching network itself must be large. However, switching networks with multistaged provisions generally need complex control. Accordingly, complex studies must be devoted to the amount of control, as well as to the switching efficiency, of networks in designing multistaged switching networks. These considerations herein lead to an evaluation study on the amount of control for path hunting and clarification of the relationship between switching network types and the amount of control for path hunting. Initially, the space‐division multistage switching network is described and then path hunting methods which are used for evaluation are examined. The results of evaluating the amount of control for path hunting are described and consideration is given to switching networks which are most favorable with respect to the amount of control for path hunting.
Thin film γ‐Fe2O3 recording disk
Authors: Terada Akira , Ishii Osamu , Shinohara Masayoshi , Nakagawa Takehiko 
Published: July 2007

AbstractAn α‐Fe2O3 thin film was sputtered onto an Al‐Mg substrate, after which it was transformed to γ‐Fe2O3 by reduction and oxidation and a magnetic memory disk was fabricated. The following results were obtained with regard to these processes: (1) The processing temperature must be below 330°C to maintain the initial surface state of the substrate. (2) If an α‐Fe2O3 film is reduced at 300°C for a few hours and oxidized in air, a homogeneous γ‐Fe2O3 film is obtained. (3) Addition of Ti to the film stabilizes the coercive force and broadens the acceptable conditions for reduction. A γ‐Fe2O3 film, to which Ti and Co have been added, has the following magnetic properties: residual magnetic flux density 2.5 kGs, coercive force 700 Oe, rectangular hysteresis ratio 0.8, coercive squareness 0.76, and film thickness 0.1 ‐ 0.2 μm. (4) Coercive force and demagnetization caused by heating and pressure are as stable as those of an ordinary sprayed magnetic memory medium. A γ‐Fe2O3 thin film disk, processed in the above‐described manner, can have a memory density of 104 − 105 bit/mm2.
Fluorescent lamp modelling for voltage fluctuations
Authors: Carrillo C. , Cidrás J. 
Published: July 2007

AbstractThe wide use of fluorescent lamps means their influence on the power system needs to be studied. A set of models that enables the evaluation of the electrical behaviour during steady state is presented in this paper. These models have different levels of complexity; starting by taking into account all the non‐linearities of the lamp, passing through neglecting the non‐linearities of the reactance, supposing the voltage wave shape of the tube to be square and, finally, treating the variations in the RMS source voltage as an steady‐state phenomenon. The most complex model needs an iterative algorithm to get results, however analytical expressions can be achieved with the other models. Several situations can be analysed with the different models but special attention is paid to the sinusoidal voltage source and the modulated voltage source cases. Also, the study presented in this paper is focused on obtaining the waveshape of current, voltage and power in the tube. These waveforms allow the study of the normal steady‐state functioning and the flicker phenomena. In this paper the simulation results for the above models in the two kinds of situations are shown. As a result, a performance test between the models is made and it is used to validate them.
Variation power, variation currents: Physical background and compensation rules
Authors: Depenbrock M. 
Published: July 2007

AbstractDerived from instantaneous power and average power the instantaneous power currents as well as the instantaneous active currents are clearly defined under steady state conditions. As a consequence instantaneous active power is also defined without any ambiguity. It is shown that if there is any difference between instantaneous power and instantaneous active power the apparent power becomes larger than the absolute value of the active power. Furthermore the rules are derived whether a power oscillation should be compensated or not and what energy storage capability of the compensator is then necessary.
Transactions evaluation and unit commitment in a bilateral electricity market using genetic algorithms
Authors: Mashhadi H. R. , Haubrich H.‐J. , Nießen S. , Modir Shanechi M. H. 
Published: July 2007

AbstractShort term optimal operation planning and the evaluation of multiple power transactions (scheduled contracts for power exchange at a specific time interval) in a deregulated environment based on a bilateral market model is a complex optimization problem for the planning personnel of electric utilities. With regard to time dependent constraints and costs in unit commitment (UC), the transaction evaluation problem and UC are coupled and therefore must be solved simultaneously. In this paper a new solution method based on genetic algorithm (GA) is presented. Due to the flexibility of GA, it is possible to select optimal transactions within the UC algorithm. The basic idea of the new method is to find an optimal load curve by means of an evolutionary process using an optimal combination of proposed transactions simultaneous with optimal scheduling of generation units. The capabilities of this approach are illustrated by means of a 26‐unit system with a set of proposed transactions that includes exchange with pump storage units and various forms of transactions such as peak, off‐peak and base load.
Robust intelligent control of a speed sensorless induction motor
Authors: Denaï M. A. , Attia S. A. 
Published: July 2007

AbstractThis paper reports results of recent applications of intelligent control techniques to a field oriented induction machine. Induction motors are characterised by complex, highly non‐linear and time‐varying dynamics and inaccessibility of some states and outputs for measurements. The advent of vector control techniques has partially solved induction motor control problems because they are sensitive to drive parameter variations and performance may deteriorate if conventional controllers such as PID are used. With fuzzy logic and neural networks based control‐lers, uncertainties in the plant parameters and non‐linearities can be dealt with more efficiently than model‐based techniques. However, a commonly known disadvantage of these methods is the lack of systematisarion and rigorous design tools. Hybrid control architectures, combining control theory with artificial intelligent tools can solve efficiently complex control problems. Three control approaches are developed and applied to adjust the speed of the drive system. The first control design combines the variable structure theory with fuzzy logic concept. In the second approach neural networks are used in an internal model control structure. Finally, a fuzzy state feedback controller is developed based on pole placement technique. A simulation study of these methods is presented. The effectiveness of these controllers is demonstrated for different operating conditions of the drive system.
Optimal capacitors on‐line operation on distribution networks by an integrated control system based on local neurocontrollers
Authors: Arces I. , Ippolito M. G. , Morana G. 
Published: July 2007

AbstractThis work proposes a contribution to the problem of an optimal control of switched capacitor banks installed in radial distribution networks, by studying the possibility of adopting an integrated control strategy based on the use of neural local controllers able to manage the status of every compensation bank. In order to analyse the feasibility of this solution, the kind of control proposed was implemented in a particular study case, which allowed to compare the performance of a set of local neurocontrollers with the results of a centralized optimisation procedure, for different conditions of load and network configuration.
Alternative modes of deficit financing and endogneous monetary and fiscal policy in the U.S.A. 1923–1982
Authors: Turnovsky Stephen J. , Wohar Mark E. 
Published: July 2007

AbstractThis paper first investigates the effects of alternative modes of deficit financing on the unemployment rate, the inflation rate and the real interest rate, within the framework of a small complete macroeconomic model. Secondly, it examines the nature of monetary and fiscal reaction functions. The two periods 1923–1960 and 1961–1982 are considered, with substantial differences in behaviour and policy being shown to exist between them. The most important conclusion is that long‐run monetary neutrality properties shown to exist over the latter period are not intrinsic to the U.S. economy, but rather are the result of the stabilization policies being conducted over that period.
A quantitative reassessment of the purchasing power parity hypothesis: Evidence from Norway and the United Kingdom
Authors: Edison Hali J. , Klovland Jan Tore 
Published: July 2007

AbstractAnnual data from Norway and the United Kingdom from 1874 to 1971 are used to reassess the empirical performance of the purchasing power parity (PPP) doctrine. The simple version of the PPP relationship is supported by the data only if different short‐run dynamics during a floating‐rate period 1914–1928 is allowed for. Two sets of factors were found to be important in amending the simple PPP model. These were short‐run cyclical variables affecting the adjustment towards the PPP equilibrium relationship and long‐run structural factors such as productivity and terms of trade. Within this expanded model the proportionality between the exchange rate and relative price levels could not be rejected.
A stochastic frontier cost function for residential child care provision
Authors: Hughes Michael D. 
Published: July 2007

AbstractWithin a public authority (the firm), there are often several production units. Costs and policy formulation are concerned with the units themselves, though inefficiency might arise at both the firm and unit levels. A stochastic frontier cost function is developed and estimated to describe one such situation where the firms are English local authorities and the production units are homes providing residential care for children. Measures of inefficiency are found for individual authorities.
Choice of employment status and the wages of employees and the self‐employed: Some further evidence
Authors: Gill Andrew M. 
Published: July 2007

AbstractUsing US data drawn from the 1978 young men NLS sample, this paper replicates a key finding reported by Rees and Shah in their analysis of self‐employment using large‐scale British data. A wage equation, which allows for sample selectivity, is estimated for subsamples of employees and the self‐employed. Despite differences between the data sets and the variables analysed, the NLS results support Rees and Shah's conclusion that there is positive selection bias in the observed earnings of employees.
Alternative specifications of the error process in the stochastic simulation of econometric models
Authors: Sterbenz Frederic P. , Calzolari Giorgio 
Published: July 2007

AbstractThis paper analyses the stochastic simulation of econometric models using three different methods for specifying the probability distribution of the structural error terms. The impact of these different assumptions on the simulation bias and model variance is explored empirically. Monte Carlo variance reduction techniques are used to distinguish the effects of the different specifications.