bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preformed Particle Gel for Conformance Control: Factors Affecting Its Properties and Applications
Authors: Bai Baojun , Li Liangxiong , Liu Yuzhang , Liu He , Wang Zhongguo , You Chunmei 
Published: August 2007

Summary
Preformed particle gel (PPG) is a particled superabsorbent crossklinking polymer that can swell up to 200 times its orginal size in brine. The use of PPG as a fluid-diverting agent to control conformance is a novel process designed to overcome some distinct drawbacks inherent in in-situ gelation systems. This paper introduces the effect of gelant compositions and reservoir environments on the two properties of PPG: swollen gel strength and swelling capacity. Results have shown that PPG properties are influenced by gelant compositions, temperature, brine salinity, and pH below 6. Temperature increases PPG swelling capacity but decreases its swollen gel strength. Salinity decreases PPG swelling capacity but increases its swollen gel strength. PPG is thermostable at an elevated temperature of 120°C if a special additive agent is added into its gelant as a composition. PPG is strength- and size-controlled, environmentally friendly, and not sensitive to reservoir minerals and formation water salinity.
Two field applications are introduced to illustrate the criteria of well candidate selection and the design and operation process of PPG treatments. Field applications show that PPG treatment is a cost-effective method to correct permeability heterogeneity for the reservoirs with fractures or channels, both of which are widely found in mature waterflooded oil fields.
Geomechanical Effects on the SAGD Process
Authors: Collins Patrick M. 
Published: August 2007

Summary
Steam-assisted gravity drainage (SAGD) is a robust thermal process that has revolutionized the economic recovery of heavy oil and bitumen from the immense oil-sands deposits in western Canada, which have 1.6 to 2.5 trillion bbl of oil in place. With steam injection, reservoir pressures and temperatures are raised. These elevated pressures and temperatures alter the rock stresses sufficiently to cause shear failure within and beyond the growing steam chamber. The associated increases in porosity, permeability, and water transmissibility accelerate the process. Pressures ahead of the steam chamber are substantially increased, promoting future growth of the steam chamber. A methodology for determining the optimum injection pressure for geomechanical enhancement is presented that allows operators to customize steam pressures to their reservoirs.
In response, these geomechanical enhancements of porosity, permeability, and mobility alter the growth pattern of the steam chamber. The stresses in the rock will determine the directionality of the steam chamber growth; these are largely a function of the reservoir depth and tectonic loading. By anticipating the SAGD growth pattern, operators can optimize on the orientation and spacing of their wells.
Core tests are essential for the determination of reservoir properties, yet oil sand core disturbance is endemic. Most core results are invalid, given the high core-disturbance results in test specimens. Discussion on the causes and mitigation of core disturbance is presented.
Monitoring of the SAGD process is central to understanding where the process has been successful. Methods of monitoring the steam chamber are presented, including the use of satellite radar interferometry. Monitoring is particularly important to ensure caprock integrity because it is paramount that SAGD operations be contained within the reservoir.
There are several quarter-billion-dollar SAGD projects in western Canada that are currently in the design stage. It is essential that these designs use a fuller understanding of the SAGD process to optimize well placement and facilities design. Only by including the interaction of SAGD and geomechanics can we achieve a more complete understanding of the process.
Gas/Water Flow in Porous Media in the Presence of Adsorbed Polymer: Experimental Study on Non-Darcy Effects
Authors: Blanchard V. , Lasseux D. , Bertin H. , Pichery T. , Chauveteau G. , Tabary R. , Zaitoun A. 
Published: August 2007

Summary
The objective of this paper is to report some experimental investigations on the effect of polymer adsorption on gas/water flow in non-Darcy regimes in homogeneous porous media, in contrast to previously available analyses focused mainly on the Darcy regime. Our investigation concentrates on gas flow either at low mean pressure, when Klinkenberg effects (or gas slippage) must be considered, or at high flow rates, when inertial effects are significant.
The experimental study reported here consists of water and nitrogen injections into various silicon carbide model granular packs having different permeabilities. Experiments are carried out at different water saturations before and after polymer adsorption over flow regimes ranging from slip flow to inertial flow. In good agreement with previous works, in the Darcy regime, we observe an increase in irreducible water saturation and a strong reduction in the relative permeability to water, while the relative permeability to gas is slightly affected. At low mean pressure in the gas phase, the magnitude of the Klinkenberg effect is found to increase with water saturation in the absence of polymer, whereas for the same water saturation, the presence of an adsorbed polymer layer reduces this effect. In the inertial regime, a reduction of inertial effects is observed when gas is injected after polymer adsorption, taking into account water-saturation and permeability modifications. Experimental data are discussed according to hypotheses put forth to explain these effects. Consequences for practical use are also put under prospect.
Beneficial versus harmful effects of Angiotensin (1-7) on impulse propagation and cardiac arrhythmias in the failing heart
Authors: De Mello Walmor C , Ferrario Carlos M , Jessup Jewell A 
Published: August 2007

Introduction. The presence of Angiotensin (1-7) (Ang 1-7) and ACE 2 in the ventricle of cardiomyopathic hamsters as well as the influence of Ang (1-7) on membrane potential, impulse propagation and cardiac excitability were investigated. Methods. Histology and immunochemistry were used to demonstrate the presence of Ang (1-7) and ACE 2 in the ventricle of cardiomyopathic hamsters. Measurements of transmembrane potentials, conduction velocity and refractoriness were made using conventional intracellular microelectrodes. The influence of Ang (1-7) on sodium pump current was investigated in voltageclamped myocytes isolated from the ventricle. Results. The results indicated the presence of Ang (1-7) and ACE 2 in myocytes of cardiomyopathic hamsters. Moreover, Ang (1-7) (10-8 M) hyperpolarised the heart cell, increased the conduction velocity, and I reduced transiently the action potential duration. The cardiac refractoriness was also increased by the heptapeptide, an effect in part reduced by an inhibitor of mas receptor. These findings indicate that Ang (1-7) has important antiarrhythmic properties. However, the beneficial effects of Ang (1-7) are dose-dependent because at higher concentration (10-7 M) the heptapeptide elicited an appreciable increase of action potential duration and early-after depolarisations. Since losartan (10-7 M) did not counteract this effect of the high dose of the heptapeptide, it is possible to conclude that activation of AT1-receptors is not involved in this effect of Ang (1-7).To investigate the mechanism of the hyperpolarising action of Ang (1-7) the influence of the heptapeptide on the sodium potassium pump current was studied in myocytes isolated from the ventricle of cardiomyopathic hamsters. The peak pump current density was measured under voltage clamp using the whole cell configuration. The results indicated that Ang (1-7) (10—8 M) enhanced the electrogenic sodium pump, an effect suppressed by ouabain (10—7 M). Conclusions. Ang (1-7) has beneficial effects on the failing heart by activating the sodium pump, hyperpolarising the cell membrane and increasing the conduction velocity. These effects as well as the increment of refractoriness indicate that Ang (1-7) has antiarrhythmic properties. At higher concentrations (10—7 M), however, the heptapeptide induced early-after depolarisations which leads to the conclusion that an optimal generation of Ang (1-7) must be achieved to permit a protective role of Ang (1-7) on cardiac arrhythmias.
Sales and Marketing Management
Authors: Gorchels Linda 
Published: August 2007

Abstract

The term “marketing” is misunderstood and misapplied in many companies and industries. To improve the understanding, it may be helpful specifying what marketing
is not
. Marketing is
not
synonymous with advertising or sales. Marketing is an umbrella term covering a host of activities involved with strategy and planning. Advertising and sales are “after” activities involved with executing the plans. Both are
part
of the marketing function in an organization. Advertising often plays a rather substantial role in encouraging
consumers
to buy products and services for
household
use (or to support the sales effort in business‐to‐business sales). Selling often plays a rather substantial role in encouraging
business
purchasers to buy products and services for
organizational
use (or in negotiating with trade partners to stock consumer products).

Introduction

Fundamental Principles

Market Intelligence

Targeting Customers

Brand Image and Positioning

Marketing Strategy & Planning

Implementing Strategies & Plans

Concluding Remarks
Information Theory of Modulation Codes and Waveforms
Authors: Georghiades Costas N. 
Published: August 2007

Abstract

The fundamental problem of communication is the conveying of information (which may take several different forms) from a generating source through a communication medium to a desired destination. This conveyance of information, invariably, is achieved by transmitting signals that contain the desired information in some form and that efficiently carry the information through the communication medium. We refer to the process of superimposing an information signal onto another for efficient transmission as
modulation
.

Introduction

Analog Modulation

Digital Modulation
Climatic variability and the population dynamics of historical hunter–gatherers: The case of Sami of Northern Finland
Authors: Helle Samuli , Helama Samuli 
Published: August 2007

AbstractOur current knowledge on climate‐mediated effects on human population dynamics is based on preindustrial agrarian societies where climate‐induced crop failures had a major impact on fertility and mortality rates. However, because most of the human evolutionary history has been shaped by hunter–gatherer lifestyle relying on diverse plant and animal food sources, it is also important to understand how climate affected the population dynamics of hunter–gatherers. We thus studied whether climate, measured as a reconstructed annual mean temperature, had concurrent or delayed effects on the key components of population dynamics, annual births and deaths, in three historical (1722–1850) Sami populations of Northern Finland that depended mainly on fishing, hunting, and reindeer herding for their livelihood. We found only weak concurrent effects of mean temperature on annual births and deaths, although in general warm years correlated with increased birth and reduced mortality rates. Likewise, temperature‐mediated delayed effects were mainly absent: in one population only, a warm previous year tended to reduce the number of births. By contrast, annual numbers of births and deaths were more closely associated, as indicated by negative correlations between births and deaths up to three previous years. To summarize, in contrast to historical agrarian societies, the population dynamics of historical Sami seemed to be only weakly associated with annual mean temperature, which may indicate that these populations, probably due to their dietary breadth, were rather unaffected by climatic variation. Am. J. Hum. Biol., 2007. © 2007 Wiley‐Liss, Inc.
Compulsive singing: another aspect of punding in Parkinson's disease
Authors: Bonvin Christophe , Horvath Judit , Christe Blaise , Landis Theodor , Burkhard Pierre R. 
Published: August 2007

AbstractWe report on two patients with advanced Parkinson's disease who were exhibiting a peculiar and stereotyped behavior characterized by an irrepressible need to sing compulsively when under high‐dose dopamine replacement therapy. Sharing many features with punding, this singing behavior is proposed as a distinct manifestation of the dopamine dysregulation syndrome in Parkinson's disease. Ann Neurol 2007
Synthesis and characterization of new aromatic polyesters containing biphenyl side groups
Authors: Honkhambe Pandurang N. , Avadhani C. V. , Wadgaonkar Prakash P. , Salunkhe Manikrao M. 
Published: August 2007

AbstractAromatic polyesters containing biphenyl side groups were synthesized by phase‐transfer catalyzed interfacial polycondensation of 1‐(4‐biphenylyl)‐1,1‐bis(4‐hydroxyphenyl) ethane (BBHPE) with terephthaloyl chloride (TPC), isophthaloyl chloride (IPC), and a mixture of TPC/IPC (50 : 50 mol ratio). Copolyesters were synthesized by utilizing different molar proportions of BBHPE and 4,4′‐isopropylidenediphenol (BPA) with IPC and TPC. The inherent viscosities of polyesters were in the range 0.44–1.26 dL/g. All the polyesters were soluble in organic solvents such as dichloromethane, chloroform, tetrahydrofuran, meta‐cresol, pyridine, N,N‐dimethylformamide, N,N‐dimethylacetamide, and 1‐methyl‐2‐pyrrolidinone. Tough, transparent, and flexible films could be cast from chloroform solutions of these polyesters. WAXD measurements indicated that all the polyesters and copolyesters were amorphous in nature. Glass transition temperature of polyesters were in the range 198–256°C, while the initial degradation temperature of polyesters were in the range 444–481°C. Copolyesters derived from BBHPE exhibited improved solubility and higher glass transition temperatures compared to the corresponding polyesters based on BPA. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Supported SiO2‐nBuSnCl3/MAO/(nBuCp)2ZrCl2 catalyzing MAO cocatalyst‐free ethylene polymerization: Study of hydrogen responsiveness
Authors: Atiqullah M. , Moman A. A. , Akhtar M. N. , Al‐Muallem H. A. , Abu‐Raqabah A. H. , Ahmed Neaz 
Published: August 2007

AbstractA supported metallocene catalyst was synthesized by sequentially loading methylaluminoxane (MAO) (30 wt % in toluene) and (nBuCp)2ZrCl2 on partially dehydroxylated silica ES 70 modified by nBuSnCl3. Its shock load hydrogen responsiveness was evaluated by polymerizing ethylene for 1 h at 8.5 bar (g) and 75°C without separately feeding the MAO cocatalyst.The shock load hydrogen feeding increased the ethylene consumption (at a fairly constant rate), catalyst productivity, as well as the resin bulk density and average particle size at ΔP (of hydrogen) ≥∼3.0 psi. The bulk density increased from 0.25 to 0.31 g/cm3. This shows a procedure for overcoming the inherent drop in catalyst productivity caused by heterogenization of metallocenes (that is a method for catalyst activation) and improving the resulting resin bulk density. The volume‐weighted mean particle diameter of the resulting polyethylenes was found to be 5.80–11.12‐fold that of the catalyst corresponding to ΔP = 0.00–7.11 psi, respectively. The resulting kinetic profiles showed to be fairly stable. However, Mw and polydispersity index were not affected. The particle size distribution, average particle size, and the scanning electron microscope photographs of the resulting resin particles confirmed the occurrence of the replication phenomenon. On the basis of the above findings, the mechanism of ethylene polymerization under the present experimental conditions has been revisited. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Rigid poly(vinyl chloride) gelation in a Brabender measuring mixer. III. Transformation in the torque maximum
Authors: Tomaszewska Jolanta , Sterzyński Tomasz , Piszczek Kazimierz 
Published: August 2007

AbstractThe processing and structural effects occurring in a poly(vinyl chloride) (PVC) compound processed in a plastograph, at the time at which the maximum value of the torque (point X on the torque curve) was reached, were studied. The unplasticized PVC compound was processed at various temperatures (150–200°C) with a kneader operating at rotors speeds of 5–40 min−1. The changes in the temperature of the compound due to kneading and its influence on the progress of PVC gelation were analyzed. The gelation progress was studied with differential scanning calorimetry, rheological measurements, and scanning electron microscopy. The maximum value of the torque occurred within the temperature range (170–180°C) of the PVC compound, and it was independent of the adjusted temperature of the mixing chamber. The processing of the PVC compound in the kneader, with high mechanical charges and a comparatively low adjusted temperature (150–170°C), spontaneously generated an effect of self‐heating, resulting in an increasing temperature of the compound. Despite the surprisingly high degree of gelation (80–98%) of the PVC compound processed under these conditions (as determined by differential scanning calorimetry), the scanning electron microscopy observations indicated significant nonhomogeneity of the fracture surface. Consequently, the kneaded PVC compound at point X of the torque curve could be treated as a two‐phase system composed of a liquid, amorphous phase and elements of a grain structure. The transformation of both phases (particularly the quantitative and qualitative changes), which was significantly dependent on the PVC temperature and the shear rate applied by the rotors, determined the state of the melted compound at this point of the torque curve. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Damping behavior of hygrothermally conditioned carbon fiber/epoxy laminates
Authors: Botelho E. C. , Pardini L. C. , Rezende M. C. 
Published: August 2007

AbstractCarbon fiber reinforced polymer composites have been used in wide variety of applications including, aerospace, marine, sporting equipment as well as in the defense sector due to their outstanding properties at low density. In many of their applications, moisture absorption takes place which may result in a reduction in mechanical properties even at lower temperature service. In this work, the viscoelastic properties, such as storage modulus (E′) and loss modulus (E″), were obtained through vibration damping tests for three carbon fiber/epoxy composite families up to the saturation point (6 weeks). Three carbon fiber/epoxy composites having [0/0]s, [0/90]s, and [±45]s orientations were studied. During vibration tests the storage modulus (E′) and loss modulus (E″) were monitored as a function of moisture uptake, and it was observed that the natural frequencies and E′ values decreased with the increase during hygrothermal conditioning due to the matrix plasticization. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
CVD of Thin Ruby Films on Si(100) and Stainless Steel for Surface Temperature Sensor Applications
Authors: Pflitsch C. , Viefhaus D. , Atakan B. 
Published: August 2007

AbstractSurface temperature measurements are crucial in many applications; one promising approach is the use of thermographic phosphors. The temperatures of surfaces coated with such a material can easily be detected by measuring and evaluating the luminescence. In the present study, the CVD of chromium‐doped aluminum oxide films (ruby) on Si(100) and stainless steel substrates is investigated with respect to this application. Films are deposited in a cold‐wall reactor from oxygen and the acetylacetonates of aluminum and chromium under pressures between 200 hPa (200 mbar) and 240 hPa, and at temperatures between 1273 K and 1473 K. The growth of aluminum oxide, containing 1 % chromium, is confirmed by X‐ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X‐ray (EDX) spectroscopy. While films grown at 1273 K are mainly γ‐Al2O3 and θ‐Al2O3, α‐Al2O3 films are grown at higher temperatures. The films are analyzed by laser excitation with regard to the temperature‐dependent luminescence. The films consisting of mainly α‐Al2O3 are promising as temperature sensors, they show the typical phosphorescence of ruby, with phosphorescence lifetimes between 2.3 ms at 298 K and 6 μs at 813 K.
Visualization of Vortex Flow Patterns with a Uniformly Perforated Showerhead in a Model Lamp Heat, Single‐Wafer Thermal Processor
Authors: Cheng T. C. , Lin T. F. , Yang J. Y. , Jian S.‐R. 
Published: August 2007

AbstractFollowing the rapid progress in the growth of semiconductor thin crystal films, rapid thermal (RT) CVD not only allows for minimization of processing and cycle time, but also enables a significant reduction in the thermal budget. The flow recirculation in the processing chamber driven by the large buoyancy resulting from the temperature differences between the wafer and input gases is known to produce detrimental effects on the film properties. In this study, the proposed 8″ rapid thermal processor (RTP) with a showerhead inlet contains three basic types of flow patterns (plug, mixed, and buoyancy‐induced flow). The physical parameters, gas flow rate, and pressure of processing chamber are investigated in detail.
Experimenteller Bau einer frei geformten Mauerwerksschale
Authors: Wendland David , Jäger Wolfram , Schulten Christoph 
Published: August 2007

AbstractAn einer frei geformten Schalenkonstruktion werden die Möglichkeiten des Mauerwerks jenseits von senkrechten ebenen Bauelementen ausgelotet. Die Form wurde mit skulpturalen Arbeitstechniken entwickelt und auf Basis einer numerischen Modellierung schrittweise so weit optimiert, dass sie standfest wurde. In der Umsetzung im Maßstab 1:1 konnte die praktische Realisierbarkeit demonstriert werden.Das Projekt zeigt die Formbarkeit von Mauerwerk auch im Rahmen der allgemeinen technischen Anforderungen an Mauerwerksbau sowie die Wege, wie sich dies erreichen lässt. Dabei erweist sich auch die Machbarkeit geometrisch komplexer Schalenkonstruktionen aus Mauerwerk.Eine weitere Besonderheit des Projekts liegt in dem Ansatz, mit Hilfe moderner Informationstechnik wie in einem industriellen Prozess einen direkten Informationsfluss von der Planung zur Fertigung zu etablieren. Für die Randträger der Schale wurde ein Konstruktionsdetail zur Bewehrung des Mauerwerks quer zur Lagerfuge entwickelt.
Kann der Mauerwerksbau noch vom ETV Beton der ehemaligen DDR profitieren?
Authors: Gerstner Horst , Jäger Wolfram , Nguyen Song Ha 
Published: August 2007

AbstractIn der ehemaligen DDR ist man 1981 bei der Berechnung und Nachweisführung im Betonbau mit dem Einheitlichen Technischen Vorschriftenwerk (ETV) Beton [1] auf ein semiprobabilistisches Sicherheitskonzept übergegangen. Ziel war die Einsparung von Material, um den stärker werdenden wirtschaftlichen Zwängen Rechnung zu tragen und um die Zusammenarbeit im Rahmen des Rates für gegenseitige Wirtschaftshilfe (RGW) zu verbessern. Die erzielten Effekte konnten durch eine differenzierte und den realen Beanspruchungsbedingungen besser angepasste Festlegung der Teilsicherheitsbeiwerte sowohl auf der Einwirkungsseite als auch auf der Widerstandsseite erzielt werden. Es wird in diesem Beitrag ein kurzer Überblick über dieses Normenwerk und seine Hintergründe gegeben. Mögliche Auswirkungen für den Mauerwerksbau werden aufgezeigt.
Ausführung von Mauerwerk – so nicht!
Authors: Schubert Peter , Reis Josef 
Published: August 2007

AbstractEine wesentliche Voraussetzung für die Gewährleistung der planmäßigen Funktionsfähigkeit von Mauerwerkbauteilen und ‐bauwerken ist deren regel‐ und sachgerechte Ausführung. Leider entspricht die Ausführungsqualität in zunehmender Anzahl der Fälle nicht den Technischen Regelwerken. Dass diesbezüglich Handlungsbedarf besteht, wird an einem konkreten Beispiel verdeutlicht.