Showing papers by "Mobil published in 2006"

Kinetics and Mechanisms of Gas Hydrate Formation and Dissociation with Inhibitors

Abstract: A common chemical used in petroleum industry for preventing hydrates is methanol. Other alcohols and glycols (thermodynamic inhibitors) can also be used to shift hydrate formation to lower temperatures and higher pressures. A new family of chemicals called kinetic inhibitors delays the formation of hydrates, but does not change the equilibrium formation conditions. We have constructed several new types of apparatus and present results on the kinetics of hydrate formation and dissociation in static and dynamic conditions with fresh water and different solutions of water, seawater, and with thermodynamic and kinetic inhibitors. We also present new morphological forms of hydrate crystal growth in different static and dynamic conditions.

Lenksystem für Fahrzeug

Abstract: Die Erfindung betrifft ein Lenksystem fur ein Fahrzeug mit drei unabhangig voneinander lenkbaren Radern und einem die Rader mittels eines wahlbaren Lenkprogramms lenkenden Lenksollwertgeber, beispielweise einem Lenkrad, wobei neben dem Lenksollwertgeber ein Bedienelement zur Verschiebung der Lenklinie und ein Bedienelement zur Steuerung der Hauptrichtung des Fahrzeugs vorgesehen sind.

A floor plate for a vehicle

Abstract: Floor plate for attaching to the bottom of a vehicle, the floor plate comprising at least one element (10) having in its lower side at least one recess (22) defining a narrowing and where a layer of glue attaching the floor plate to the bottom extends into the recess and past the narrowing.

A Simple Transform Method in the Field of Image Processing

Abstract: This paper proposes a simple transform algorithm for digital image processing, which has the advantages of wavelet transform technique. This transform is theoretically reversible. Computer simulations are performed to confirm the validity.

Accounting Skills Hotel Enterprises Need Today

Abstract: The article presents a view of current happenings in the business and economic environment that are significantly influencing the knowledge requirements of modern accountants both worldwide and locally. First, we define the specific skills accountants are required to have apart from an in-depth expert knowledge of accounting. These skills have set the final boundary between accounting and bookkeeping. Later, the perspectives of certified accountants in Great Britain and Slovenia, as well as accountants working for Slovenian hotel enterprises are presented as regards the key factors influencing a change in accountants' tasks. Finally, the skills of modern accountants are presented, along with the underlying education and training system needed for gaining the title of a certified accountant.

A Model for Radio Access Unit Selection in Distributed Radio System

Abstract: In this paper, we present an analytic model for radio access unit selection in distributed radio system. The selection strategy is based on received signal strength measurements and described as a multiple state Markov chain. Performance analysis results show that numeric data achieved from the model are in good agreement with simulation results, which verifies the validity of the model. This model is helpful in designing seamless handoff schemes in distributed radio system.

The Network Centralized Location Scheme Based On Doppler in Distributed Antenna System

Abstract: This paper presents an estimation method of the location of user equipment (UE) using the velocity measure based on Doppler frequency shift in square distributed antenna system (DAS) layout. When the UE enters the cell, all remote antenna units (RAU) estimate the entering border of the cell, the initial entering position, the velocity of the UE, then update the new position till the UE move out from the cell. Thus the moving track of UE can be estimated. The performance is theoretically analyzed and simulations are performed to verify the correctness.

Asymptotic SER and Outage Probability of MIMO MRC in Correlated Fading

Abstract: This letter derives the asymptotic symbol error rate (SER) and outage probability of multiple-input multiple-output (MIMO) maximum ratio combining (MRC) systems. We consider Rayleigh fading channels with both transmit and receive spatial correlation. Our results are based on new asymptotic expressions which we derive for the p.d.f. and c.d.f. of the maximum eigenvalue of positive-definite quadratic forms in complex Gaussian matrices. We prove that spatial correlation does not affect the diversity order, but that it reduces the array gain and hence increases the SER in the high SNR regime.

Nuclear Magnetic Resonance of Coating and Adhesive Systems

Abstract: The interaction of the magnetic moment of an atomic nucleus with a static magnetic field gives rise to nuclear magnetic resonance (NMR). Examination of NMR can reveal both the chemical structure and physical characteristics of a chemical system and this makes the technique particularly useful for the study of materials such as those encountered in coating and adhesive applications. No other spectroscopic technique can offer such a detailed description, both qualitative and quantitative, of molecular structure, including features such as stereochemistry, reaction kinetics and surface phenomena. Each nucleus has a distinct precession frequency, allowing different (e.g. 13C, 1H, 29Si) to be observed within a sample. The technique does, however, suffer from a few drawbacks. First, it is not a particularly sensitive technique, and it is most readily applied to features that constitute at least a few percent of the sample. Second, sample preparation can be difficult; this can be especially true for coatings and adhesives materials, as will be discussed. The most detailed chemical information is obtained from the spectra of liquids or solutions, which precludes cross-linked or cured materials. The spectra of solids, including cross-linked and cured materials, must be studied using complex experimental approaches, and these often suffer from poor resolution.

Verfahren und Vorrichtung zur drahtlosen Signalübertragung und Verwendung eines derartigen Verfahrens

Abstract: Die Erfindung betrifft ein Verfahren und eine Vorrichtung zur drahtlosen Ubertragung mindestens eines Messwertes sowie die Verwendung eines derartigen Verfahrens. Eine Messeinrichtung weist einen Empfanger und einen Sender sowie einen nachschwingenden Resonator auf. Der Resonator wird in seiner Frequenzcharakteristik vom zu messenden Wert beeinflusst. Eine Steuer- und Auswerteeinrichtung weist zwei unabhangige Generatoren zur Erzeugung von Signalen mit einer ersten bzw. zweiten Hochfrequenz auf, aus welchen die Resonatorfrequenz durch Differenzbildung abgeleitet wird.

EVICD – eine Lebensdauermethode für komplexe mehrachsige Betriebsbelastungen für die Praxis

Abstract: Im vorliegenden Beitrag wird eine Ubersicht uber den letzten Entwicklungsstand von EVICD, der Anrisslebensdauervorhersagemethode fur beliebige mehrachsige Beanspruchungen gegeben. Das ursprunglich von W. Ott vorgeschlagene inkrementelle Schadigungsberechnungsverfahren auf der Grundlage der geleisteten plastischen Arbeit, das spater um einen zweiten Schadigungsparameter auf der Basis der Normalspannungen auf den Ebenen mit maximaler Schubspannung (EVICD-N) bzw. auf den Oktaederebenen (EVICD-J1) erganzt wurde, erfuhr eine Weiterentwicklung in den folgenden Punkten: Es wurde eine spezielle Input-Section vorgesehen, die fur gangige Formate ingenieurmasiger Vorgaben von Betriebsbeanspruchungen offen ist, ebenso fur die Eingabe der Ergebnisse von Dehnungsmessungen. In die Input-Section ist auch die mehrachsige Neuber-Methode zur rationellen Bestimmung der Beanspruchungen an Bauteilkerben aufgenommen. Am Ausgang der Input-Section wird der ortliche elastisch-plastische Spannungsablauf oder Dehnungsablauf an den Lebensdauerberechnungsmodul ubergeben. In den Schadigungsberechnungsmodul wurde das Mroz-Garud-Plastizitatsmodell eingearbeitet, weiterhin der Schadigungsberechnungsablauf durch die Einfuhrung eines ubersichtlichen Flussdiagramms fur potentielle Anwender transparent gemacht und als FORTRAN-Code realisiert. Damit wurden notwendige Voraussetzungen fur den allgemeinen Einsatz von EVICD in der Praxis geschaffen. EVICD wurde weiterhin auf breiter Basis verifiziert. Anhand einer von E. Haibach vorgeschlagenen Bewertungsmethode wird gezeigt, dass die Vorhersageergebnisse gegenuber denjenigen konventioneller Methoden verbessert werden konnten. EVICD – an advanced crack intiation life prediction method for engineering application In the present paper an overview of the latest stand in the development of EVICD, a crack initiation life prediction method for arbitrary multiaxial loading, is given. The incremental prediction method which was originally proposed by W. Ott and which was later extended by the introduction of a secondary damage parameter either based on the normal stress on the planes with maximum shear stresses (EVICD-N) or the normal stress on the octahedral planes (EVICD-J1) has been further developed: A special Input Section was created, which is open to all important types and formats of engineering input data for fatigue calculations. The results of strain measurements can also be taken. Further on, the multiaxial Neuber-Method has been worked in for a fast determination of the elastic plastic stresses and strains at fatigue critical locations of components. At the end of the Input Section the elastic plastic stress or strain path at the fatigue critical location is transferred to the damage evaluation modul of EVICD for an evaluation of the crack initiation life. The Mroz-Garud plasticity model has been worked in the damage evaluation model. The fatigue damage evaluation does occur after a transparent flow diagram and has been realized as a FORTRAN Code. This is important for a general use of EVICD in practice. Meanwhile EVICD has been verified on a broader basis. A representation of the prediction results after EVICD vs. the corresponding experimental results after a proposal of E. Haibach shows, that the prediction capability of EVICD has become better than that of conventional fatigue prediction methods.