Showing papers by "Mobil published in 2009"

AlR2Cl/MgR2 combinations as universal cocatalysts for Ziegler–Natta, metallocene, and post‐metallocene catalysts

Abstract: Combinations of dialkylaluminum chlorides and dialkylmagnesium compounds, when used at molar [AlR2Cl]:[MgR2] ratios ≥ 2, act as universal cocatalysts for all three presently known types of alkene polymerization catalysts—Ziegler–Natta, metallocene, and post-metallocene. When these cocatalysts are used with supported Ti-based Ziegler–Natta catalysts, they produce catalyst systems which are 1.5–2 times more active than the systems utilizing AlR3 compounds as cocatalysts. Combinations of AlR2Cl/MgR2 cocatalysts and various metallocene complexes produce single-center catalyst systems similar to those formed in the presence of MAO. The same cocatalysts activate numerous post-metallocene Ti complexes containing bidentate ligands of a different nature and produce multicenter systems of very high activity. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3271–3285, 2009

Post‐oligomerization of α‐olefin oligomers: A route to single‐component and multicomponent synthetic lubricating oils

Abstract: This article describes a synthetic route to single-component and multicomponent base stocks for synthetic lubricated oils. The synthesis was carried out in two stages. First, oligomers of α-olefins (1-hexene, 4-methyl-1-pentene, and 1-decene) were prepared via reactions catalyzed by metallocene catalysts. The distribution of the oligomers with respect to their oligomerization number could be controlled by the reaction temperature. The oligomer mixtures were then fractionated, and the lightest components, dimers and trimers, were separated. Finally, the latter materials, branched α-olefins containing vinylidene double bonds, were further oligomerized with cationic catalysts. One such material prepared in the two-stage process, the dimer of the 1-decene dimer (C40 product), has a kinematic viscosity of 6.4 cs at 100°C and a viscosity index of 147. It represents the first example of a single-component base stock for synthetic lubricating oils. The post-oligomerization procedure was performed on unfractionated oligomer mixtures as well, leading to an improved distribution of the final materials with respect to the carbon atom number. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Modeling the variability in annual carbon fluxes related to biological soil crusts in a Mediterranean shrubland

Abstract: . Biological soil crusts (BSC) constitute a spatially prominent part of the photosynthesizing vegetation in many dryland ecosystems. This study assesses the annual net carbon deposition related to BSC growth in a Mediterranean shrubland for the years 2001–2003 using a model developed to account for the nature of hydration in the poikilohydric life trait of the BSC. Data for BSC-related net CO2 fluxes were obtained from in-situ measurements at the International Long-term Ecological Research site Sayeret Shaked (ILTER-SSK) in the northern Negev Desert, Israel. The BSC was smooth to rugose, up to 15 mm thick and consisted mainly of mosses, cyanobacteria and cyano-lichens. In order to obtain annual estimates, BSC-related CO2 fluxes were correlated with climate records provided by the meteorological station of the Terrestrial Ecosystem Monitoring Site network (TEMS) adjacent to SSK. The annual carbon deposition related to BSC growth was assessed from (1) an overall mean of net CO2 flux multiplied with annual activity periods of BSC based on precipitation records, and (2) from a simple precipitation-driven activity model (PdAM). This model combines an algorithm, previously developed to model gas exchange processes in vascular plants, with an empirical module that switches the algorithm on as soon as water is available to maintain activity of poikilohydric BSC. Based on a constant BSC area index of 0.6 m2 m−2 at ILTER-SSK, the final model suggests a large inter-annual variability in BSC-related net carbon deposition ranging from 7 to 51 kg ha−1 yr−1.

A Research on EOG Feature Parameters Extraction Based on Linear Predictive Coding Model

Abstract: EOG is a very effective eye movement recording method, which is not only noninvasive, but also can record any eye movements' information. In order to extract some features come form these information contained in EOG automatically, this paper presents a novel EOG feature parameters extraction algorithm. The proposed algorithm includes three main parts. The first is endpoint detection unit which detects the startpoint and endpoint of EOG signals. The second is a preprocessor which consists of band-pass filter, frame blocking procedure and windowing step. The third is feature parameters extracting part which extracts EOG feature by a linear predictive coding model and converts LPC parameters to LPC cepstral (LPCC) coefficients. Finally, the paper gives experimental results.

Enhancing the Testability of Web Services

Abstract: For the foreseeable future, testing will remain the mainstay of software quality assurance and measurement in all areas of software development, including Web services and service-oriented systems. In general, however, testing Web services is much more challenging than testing normal software applications, not because they are inherently more complex, but because of the limited control and access that users of Web services have over their development and deployment. Whereas the developers of normal applications, by definition, have full control over their application until release time, and thus, can subject them to all kinds of tests in various combinations (e.g., integration testing, system testing, regression testing, acceptance testing, etc.), users of Web services can often only test them at run-time after they have already been deployed and put into service. Moreover, users of Web services often have to share access to them with other concurrent users. In order to effectively test Web services under these conditions special measures and approaches need to be taken to enhance their testability. Right from the early phases of development, the testability of services needs to be taken into account and “designed into” services. In this chapter we consider these issues and with the aid of a case study we present a methodology that can be used to enhance the testability of Web services. DOI: 10.4018/978-1-60566-042-4.ch010

Heinz Heinemann’s Legacy at ExxonMobil: An Illustrious Career in Industrial Catalysis

Abstract: Heinz Heinemann contributed significantly to the field of heterogeneous catalysis over his 60 year career. As a scientist and later Catalysis Research Manager at ExxonMobil’s (then Mobil’s) Princeton Laboratory, he oversaw the development of many of the ZSM-5 processes for fuels and chemicals, most notably, a post-reforming process known as M-Forming. The M-Forming process development program justified Mobil’s commercial development of ZSM-5, which in turn led to the rapid development of many other ZSM-5 processes including Methanol-to-Gasoline, Middle Distillate Dewaxing, xylene isomerizaion, and lubes dewaxing.

An Efficient Joint Timing and Frequency Offset Estimation for OFDM Systems

Abstract: This paper presents a new joint frame synchronization and frequency offset estimation algorithm for orthogonal frequency division multiplexing (OFDM) systems as a modification to Zhang's method (Zhang et al., 2005). By designing a new training preamble weighted by PN sequence, the timing estimator is improved (at least 3dB with low SNR). By estimating time offset first, the computational load is greatly reduced with no loss in frequency offset estimation accuracy. The performance of the proposed method is evaluated by computer simulations in terms of timing error rate (TER) together with computational complexity.

A Recognition Algorithm for Chinese Chararcter Based on Minimum Distance Classifier

Abstract: This paper investigates problems of image character recognition, especially Chinese character recognition. We herein recommend a novel recognition algorithm which is based on minimum distance classifier. Aiming at a subset of the features in a character that a human can typically see for the identification of typewritten Chinese characters, the algorithm attempts to work with two classes of feature extraction-structure and statistics. The statistic feature decides the primary class and the structure feature is used to identify Chinese characters. This paper also describes, analyzes and compares several other methods and results. Experimental results indicate that the recognition algorithm is effective for Chinese character in image.

Method for applying marking material on upper surface of object, involves removing non-fixed marking material from upper surface, where non-fixed material remains on surface area that is not exposed to laser beam

Abstract: The method involves providing a marking material in connection with a binding material as a film material in the form of a thin film (FI) on a carrier (TR). The marking material is detached from the carrier and applied on an upper surface (OO) of an object (OB). The marking material is exposed to a laser beam to fix the marking material on the upper surface. A non-fixed marking material is removed from the upper surface, where the non-fixed marking material remains on a surface area of the upper surface's. The surface area is not exposed to the laser beam. The marking material contains a laser absorption material, a mineral material or a laser meltable material such as glass solder and hot-melt adhesive.

Verfahren zum dynamischen Lenkprogrammwechsel

Abstract: Die vorliegende Erfindung betrifft ein Verfahren zur dynamischen Steuerung eines Lenkprogrammwechsels zwischen geometrisch unabhangigen Lenkprogrammen eines Fahrzeugs, insbesondere Flurforderfahrzeug, das einen stetigen Ubergang zwischen den Lenkprogrammen sicherstellt und damit das Fahren und Lenken des Fahrzeugs wahrend des Lenkprogrammwechsels ermoglicht.

Method and device for purification of water

Abstract: In the purification of water by reverse osmosis, water is driven through a membrane which is formed into an element and is placed in a pressure vessel. The supplied water is pressurised unpurified water which is supplied from outside. The pressurisation takes place manually by a device with sufficient volume flow. A certain part of the water is withdrawn from the downstream side of the element. That amount of water which is the difference between supplied and withdrawn flow under pressure is forced through the membrane. This permeate flow is charged into the pressure vessel for permeate via the pressure which prevails on the inflow side of the membrane. The present invention also relates to a valve for use in the purification of water by reverse osmosis.