bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design‐based stereological analysis of the lung parenchymal architecture and alveolar type II cells in surfactant protein A and D double deficient mice
Authors: Jung Anja , Allen Lennell , Nyengaard Jens R. , Gundersen Hans Jørgen G. , Richter Joachim , Hawgood Samuel , Ochs Matthias 
Published: August 2005

AbstractAlveolar epithelial type II cells synthesize and secrete surfactant. The surfactant‐associated proteins A and D (SP‐A and SP‐D), members of the collectin protein family, participate in pulmonary immune defense, modulation of inflammation, and surfactant metabolism. Both proteins are known to have overlapping as well as distinct functions. The present study provides a design‐based stereological analysis of adult mice deficient in both SP‐A and SP‐D (A−D−) with special emphasis on parameters characterizing alveolar architecture and surfactant‐producing type II cells. Compared to wild‐type, A−D− mice have fewer and larger alveoli, an increase in the number and size of type II cells, as well as more numerous and larger alveolar macrophages. More surfactant‐storing lamellar bodies are seen in type II cells, leading to a threefold increase in the total volume of lamellar bodies per lung, but the mean volume of a single lamellar body remains constant. These results demonstrate that chronic deficiency of SP‐A and SP‐D in mice leads to parenchymal remodeling, type II cell hyperplasia and hypertrophy, and disturbed intracellular surfactant metabolism. The design‐based stereological approach presented here provides a framework for the quantitative lung structure analysis in gene‐manipulated mice as well as in human lung disease. © 2005 Wiley‐Liss, Inc.
Exploring the rabbit hole of possibilities by myself or with my group: The benefits and liabilities of activating counterfactual mind‐sets for information sharing and group coordination
Authors: Liljenquist Katie A. , Galinsky Adam D. , Kray Laura J. 
Published: August 2005

AbstractThe current experiment explored the effect of activating a counterfactual mind‐set on the discussion of unique information and group judgment accuracy. Evidence suggests that a counterfactual mind‐set is characterized by a focused, analytic mental state and, when activated at the group level, improves group judgment accuracy in the murder mystery paradigm (a hidden profile task). We hypothesized that the beneficial effect of the counterfactual mind‐set would only help group problem‐solving tasks if the mind‐set had been activated at the group level, allowing the analytical mind‐set to play out in an atmosphere of synergistic coordination. In contrast, if this highly focused mental state is activated at the individual level, it could impair group judgment quality because inwardly focused analytical individuals may fail to coordinate their behavior with other group members. Consistent with our hypothesis, activating a counterfactual mind‐set at the individual level had a debilitating effect on the group judgment task, whereas activating a counterfactual mind‐set at the group level had a facilitative effect, increasing information sharing, synergistic coordination and judgment accuracy. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis of poly(Pro–Hyp–Gly)n by direct polycondensation of (Pro–Hyp–Gly)n, where n = 1, 5, and 10, and stability of the triple‐helical structure
Authors: Kishimoto Takahiro , Morihara Yasushi , Osanai Michinori , Ogata Shin‐ichi , Kamitakahara Masanobu , Ohtsuki Chikara , Tanihara Masao 
Published: August 2005

AbstractPro–Hyp–Gly is a characteristic amino acid sequence found in fibrous collagens, and (Pro–Hyp–Gly)10, which has been widely used as a collagen‐model peptide, forms a stable triple‐helical structure. Here, we synthesized polypeptides consisting of the Pro–Hyp–Gly sequence by direct polycondensation of (Pro–Hyp–Gly)n, where n = 1, 5, and 10, using 1‐hydroxybenzotriazole and 1‐ethyl‐3‐(3‐dimethyl‐aminopropyl)‐carbodiimide hydrochloride in both phosphate buffer (pH = 7.4) and dimethylsulfoxide (DMSO) solutions for 48 h at 20°C. The reaction of (Pro–Hyp–Gly)5 and (Pro–Hyp–Gly)10 in DMSO successfully gave polypeptides with molecular weights over 10,000, whereas low molecular weight products were obtained by reaction in phosphate buffer (pH = 7.4). In contrast, Pro–Hyp–Gly at a concentration of 50 mg/mL in phosphate buffer (pH = 7.4) gave polypeptides with molecular weights over 10,000. The Fourier transform infrared (FTIR) and 1H nuclear magnetic resonance (NMR) spectra of poly(Pro–Hyp–Gly)10 revealed that the polymerization of (Pro–Hyp–Gly)10 described in this report had no side reactions. Each polypeptide obtained shows a collagen‐like triple‐helical structure, and the triple‐helical structures of poly(Pro–Hyp–Gly) and poly(Pro–Hyp–Gly)10 were stable up to T = 80°C, which suggests that the high molecular weight promotes stability of the triple‐helical structure, in addition to the high Hyp content. Furthermore, transmission electron microscopy (TEM) observations show that poly(Pro–Hyp–Gly)10 aggregates to form nanofiber‐like structures about 10 nm in width, which suggests that a Pro–Hyp–Gly repeating sequence contains enough information for triple‐helix formation, and for subsequent nanofiber‐like structure formation. © 2005 Wiley Periodicals, Inc. Biopolymers 79: 163–172, 2005This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Interfacial areas and gas hold‐ups at elevated pressures in a mechanically agitated gas‐liquid reactor
Authors: Oyevaar Martin , Zijl Ad , Westerterp Roel 
Published: August 2005

AbstractInterfacial areas and gas hold‐ups were determined at pressures of up to 1.7 MPa in a glass vessel, 88 mm in diameter and of standard geometry. Superficial gas velocities between 0.25 and 2.0 cm/s were used and the stirring speed varied between 4 and 30 rps. The interfacial areas were determined by the chemical method, using the model reaction between CO2 and aqueous diethanolamine (DEA). Hold‐ups were determined by observation of differences in height. In contrast to literature indications, the gas hold‐up was found to be independent of reactor pressure. This is also true for the interfacial area.
Engineering aspects and applications of crossflow microfiltration
Authors: Ripperger Siegfried 
Published: August 2005

AbstractCrossflow microfiltration (CMF) is a pressure driven membrane process for the separation of suspended microparticles, bacteria and emulsion droplets. The fluid to be filtered flows in parallel to the membrane surface and restricts the formation of a filter cake. This contribution explains the basic process characteristics and the combination of the crossflow technique with other membrane cleaning methods (periodic backflushing, chemical cleaning). Special attention is paid to the influence of different process parameters on the flux through the membrane. The principle of plant design and different operation modes are described. Engineering aspects such as hydrodynamics, energy requirement and selection of construction materials are discussed in some detail.
The influence of stress and attrition on crystal size distribution
Authors: Pohlisch Joachim , Mersmann Alfons 
Published: August 2005

AbstractAn important parameter influencing the crystal size distribution in mass crystallization from solution is the mechanical stress exerted on crystals in the crystallizer. This contribution presents the study of the influence of mechanical stress and attrition of the system potassium nitrate‐water in an FC‐crystallizer and in various draft‐tube crystallizers, fitted with different types of impellers. The intensity of stress is a newly defined variable which is used to describe the level of stress in crystallizers. The reduction of crystal size by attrition is described by the linear attrition rate. The influence of impeller design and crystal hold‐up on crystal size distribution and scale‐up rules is discussed.
Attrition and secondary nucleation in crystallizers
Authors: Mersmann Alfons , Sangl Reinhard , Kind Matthias , Pohlisch Joachim 
Published: August 2005

AbstractThe mean crystal size of coarse crystalline products is determined by secondary nucleation and crystal growth. Secondary unclei are mainly produced by contacts of crystals with parts of the crystallizer or with other crystals. As a consequence, attrition effects are very important. In this paper, a model is proposed in order to calculate the attrition rate of crystals, depending on the physical properties of the crystalline product, the geometry of the crystallizer and on the operating conditions such as the stirrer speed or the suspension density. The effective rate of secondary nucleation can be expressed in terms of the attrition rate by introducing effective values for number and size of attrition particles. Finally, a scale‐up criterion based on this model is derived. This criterion allows to predict effective rates of secondary nucleation and mean crystal sizes if data obtained in a laboratory crystallizer are available.
Theoretical and experimental study of sedimentation in vertical flow tanks
Authors: Horn Eva‐Maria , Wiesmann Udo 
Published: August 2005

AbstractSettling characteristics of four different suspensions were measured by batch settling tests (glass spheres in glycerol‐water mixtures and CaCO3) and by continuous settling test in a bench‐scale vertical flow tank (activated sludge and kaolin in water), including the measurement of solids concentrations inside the tank. The characteristics could be described by different correlation functions which now include all the information about the settling behaviour of ideal suspensions. Continuous settling experiments in a bench‐scale vertical flow tank were carried out with the same four material systems. These results correspond with sufficient accuracy to those from the theory of limiting flux if the settling characteristics determined earlier are considered.
Effect of combustion air preheating on NOx emissions from gas burners in high‐temperature industrial applications
Authors: Flamme Michael , Beckervordersandforth Christian Paul , Kremer Hans 
Published: August 2005

AbstractNOx emissions from different commercial gas burners for metal heat treatment applications were measured for a research project of the Gaswärme‐Institut. The burners, rated at up to 50 kW, were installed for the tests in a laboratory combustion chamber operated at temperatures of up to 1400°C. The air for combustion was preheated to maximum temperature of 600°C. Following the tests, the potentials of different NOx control techniques were investigated. Methods explored included staged combustion air injection, staged fuel injection and fuel gas injection into the flue for NOx reduction. The results showed that it is feasible to reduce the NOx content of flue gases by as much as 90%.
Thermal deactivation of heterogeneous catalyst, part 1. The theta‐rule ‐ a critical review
Authors: Kral Hans 
Published: August 2005

AbstractThermal deactivation can be described either by deactivation kinetics or by the isokinetic effect. The latter expression is used synonymously with the “compensation effect” and the “Theta‐Rule”. An examination of the original literature shows that only the compensation effect is applicable to thermal deactivation but not the Theta‐Rule. The introduction of the preparation temperature as a parameter of the compensation effect results in a “modified Theta‐Rule”, which describes the experimental data and is proposed for the non‐separable kinetics. The consequence of the observed deviations from the validity range of the Theta‐Rule is that the activation energy cannot be used as a universal activity criterion.
Heat transfer between particle beds and submerged surfaces
Authors: Molerus Otto , Scheuring Horst 
Published: August 2005

AbstractTheoretical modelling of heat transfer to particle beds comprises two sequential steps: transfer from the heating surface to contacting particles followed by transfer to the interior of the bed. Two different limiting case can be formulated for the second step: unmixed and homogeneously mixed bed. In the case, heat is transferred gradually via a repeated sequence of heat transfer in the gap between adjacent particles and conduction in the particulate material. In the second case, heat is transferred to the interior of the bed by mixing of particles which have previously attained the temperature of the heating surface. On the other hand, the mixing motion maintains a homogeneous lower temperature throughout the bed. Theory predicts a significant and easily measurable difference in the behaviour of heat transfer coefficients for the two regimes at long contact times t: unmixed beds ∝ \documentclass{article}\pagestyle{empty}\begin{document}$$ \sqrt t $$\end{document} and homogeneously mixed beds ∝ 1/t. For short times t, both regimes show the same behaviour, namely of t.From a theoretical standpoint, it makes sense to differentiate further between the behaviour patterns of unmixed beds: at long times t, instantaneous heat transfer coefficients are independent of heat transfer form the heating surface to adjacent particles. Comparison with experimental result from literature shows that the derived models, which are consistent, are suitable for describing the heat transfer from submerged surfaces to unmixed and mixed beds of particles.
The role of energy dissipation in contacting and mixing devices
Authors: Villermaux Jacques 
Published: August 2005

AbstractThe aim of the present paper is the discussion of the relevance of power dissipation as a criterion for the understanding and prediction of transfer and mixing efficiencies in contactors and chemical reactors. After reviewing the approach of Le Goff to the energetic efficiency of exchangers, based on the deviations from Chilton‐Colburn analogy, the following processes are studied: mass transfer between a flowing fluid and a reactive solid surface, transfer to a fixed object in a stirred vessel, macro‐ and micromixing of miscible fluids, and mass transfer in fluid‐fluid contractors (especially gas‐liquid reactors). It is concluded from the various examples that a direct relationship between the dissipated power and intensity of transfer or mixing can be established only under the two following conditions: local values must be considered at the point where the actual transfer and mixing occur, and not average values over the whole device, and power dissipation must be coupled to transfer or mixing and appear physically as the driving force of the process.
Mass transfer behaviour of gas‐liquid jet loop reactors
Authors: Warnecke Hans‐Joachim , Geisendörfer Matthias , Hempel Dietmar Christian 
Published: August 2005

AbstractA special type of jet loop reactor (JLR), designed for continuous operation and short residence times was investigated with regard to its mass transfer behaviour, described by the volumetric mass transfer coefficient kLa. The jet stream and superficial gas velocities are varied in two JLRs of different sizes, equipped with different nozzles. Fully desalinated water, 0.08 molar NaCI solution and solutions of different concentration of carboxymethyl cellulose (CMC) are used as the liquid phase. A steady‐state physical method is employed to determine kLa: air oxygen is purged from the liquid phase by gaseous nitrogen. The measurements show that the reactor is characterized by high power density and high mass transfer performance. No limit of mass transfer capacity was observed in the chosen ranges of volumetric gas and liquid flow rates, i.e. at a given jet stream velocity, the relationship between kLa and the superficial gas velocity is nearly linear. The investigations show that the mass transfer contributed by the jet stream largely depends on liquid phase composition.
Modelling of multiphase detonations with drop disintegration ‐ description of thermal detonations
Authors: Carachalios Constantinos , Unger Hermann , Bürger Manfred 
Published: August 2005

AbstractA model is presented which consists of steady‐state and transient codes for the description of reacting multiphase flow fields, including hydrodynamic fragmentation of liquid drops in relative flows. An application of this model for the description of large scale melt‐coolant interactions (thermal detonations) is described. A simulation of two‐phase chemical detonations, especially those with hydrodynamic disintegration of liquid fuel drops in the reaction zone, is possible, in principle, within the framework of the modeling.
Model discrimination and parameter estimation in the kinetic study of methanol synthesis
Authors: Xu Jianguo , Rickert Thomas , Hoffmann Ulrich 
Published: August 2005

AbstractThe new model discrimination method is based on the correlation coefficient test of experimental data sets for different reactions, without requiring a prior parameter estimation. The new parameter estimation method reduces by n the number of dimensions to be tested, compared to the classical method where n is the number of independent reactions in the system. This has reduced the computation time for most complex reactions to a level, comparable to that needed for single reactions. The example used is the kinetic study of methanol synthesis in which the formation rates of methanol, methane, ethanol and ethane are considered. Two adequately accurate models were obtained from an extensive range of plausible models by using the new model discrimination and parameter estimation method with a relatively small computation effort.
Kinetic investigation of methacrylic acid synthesis on hetropoly‐compounds
Authors: Haeberle Thomas , Emig Gerhard 
Published: August 2005

AbstractThe kinetics of heterogeneously catalyzed methacrylic acid synthesis from isobutyric acid has been investigated. Initial catalyst screening pointed to 10‐molybdo‐2‐vanado‐phosphoric acid and its Cs‐salts as the most promising catalysts. A model describing the reaction behaviour of all the different hetropoly‐compounds used in this work was developed. A relationship was found between model parameters and composition of different catalysts. First insight was gained into the catalyst deactivation phenomena. Deactivation appears to be caused mainly by loss of molybdenum with simultaneous collapse of the Keggin structure.
Less known behaviour of gas‐solid reactions: The expanding core model in catalytic and non‐catalytic systems
Authors: Doraiswamy Laxmangudi K. , Gokarn Ashok N. 
Published: August 2005

AbstractGas‐solid reactions cover a wide spectrum of industrial products. Over the years, many conceptual models have been developed to describe the progress of a gas‐solid reaction starting outside the solid particle as well as that occurring throughout the particle. But the behaviour of a reaction, initiated inside the pellet, is less known. In this paper, a brief outline is given of this relatively rare but important mode of gas‐solid reaction. The causes of this relatively less known behaviour and characteristic features of five typical systems displaying it are discussed.
Reversible absorption of nitric oxide in low volatile organic liquids containing cupric halides
Authors: Gestrich Wolfgang 
Published: August 2005

AbstractThe absorption of nitric oxide (NO) in phosphoric acid esters and polyethylene glycol ethers which contain cupric halides has been investigated. Due to high solubility of cupric halides and high equilibrium constants of formed nitrosyl complexes, the effective solubility of nitric oxide can be enhanced to about 100‐fold its solubility in the salt‐free organic liquid which itself amounts to only about 5‐fold the NO‐solubility in water. Calculations taking into account flue gas conditions indicate that the required gas‐liquid ratio in industrial absorption processes will lie in the normal range of flue gas scrubbing processes, namely in the region of 400:1 to 1000:1 in volume. Thus, such a reversible absorption process could a viable alternative to SCR‐processes in flue gas denitrification.
Heat transfer to submerged surfaces in coarse‐grained pressurized fluidized beds and fixed beds
Authors: Schweinzer Jürgen , Molerus Otto 
Published: August 2005

AbstractThis contribution reports on the theory underlying a uniform representation of heat transfer to submerged surfaces in fixed bed reactors and of gas convective part of heat transfer in fluidized beds with coarse‐grained bulk solids and/or at elevated pressure. Based on an analysis of the pressure drop behaviour of fixed bed percolation at different gas pressures and with different bulk solids, a new dimensionless pressure drop parameter was developed. Fixed bed heat transfer data are very well correlated by this new dimensionless number. As soon as fluid throughput is in excess of minimum fluidization velocity, the pressure drop parameter transforms into the well‐known Archimedes number. These two dimensionless numbers are connected by the condition of equilibrium for pressure drop and mass of practices in a fluidized bed. This equilibrium is fulfilled as soon as fluidization commences. Up to now, the Archimedes number has been generally accepted as the significant parameter, determining the gas convective part of heat transfer in fluidized beds; however, without any physical interpretation of this parameter. Introduction of the pressure drop number, which is consistent with the Archimedes number, reduces the heat transfer behaviour to pressure drop characteristics. The usefulness of this concept is proven by the comparison of experimental results and prediction.
Selective hydrogenation: Kinetic investigation of 1, 3‐cyclo‐octadiene and cyclo‐octene hydrogenation
Authors: Hass Thomas , Gaube Johann 
Published: August 2005

AbstractThe vapour phase hydrogenation of 1,3‐cyclo‐octadiene (COD) over Pd on alumina has been studied in the gas phase, using a recycle reactor. The dependences of COD hydrogenation rates and those of the consecutive cyclo‐octene (COE) hydrogenation on the reaction conditions are well described by a model which takes into account mass transfer in the porous layer of palladium. The kinetics of the COE hydrogenation is of a Langmuir‐Hinshelwood type. The hydrogenation of COD is of first order with respect to hydrogen. The reaction order with respect to COD is −0.15. If the catalyst surface is completely covered by COD, the hydrogenation of COE is totally suppressed. This indicates a much stronger adsorption of COD than of COE. Hydrogenation of COE can only occur in the innermost part of the pores when the transport of COD by diffusion is insufficient to supply the entire active surface of the catalyst. This happens if the ratio P/PCOD exceeds 2/φ2 with φ being the Thiele's modulus. This relationship permits a simple evaluation of the effective diffusion coefficient in the porous Pd‐layer.
Absorption process for the removal of organic solvents from exhaust air
Authors: Geisthardt Klaus , Holtze Jürgen , Ludwig Rolf , Pilhofer Theo 
Published: August 2005

AbstractIt is shown in this report that, under certain conditions, cleaning of exhaust air by absorption presents an interesting alternative to the existing methods. In particular, this process can be used with advantage for small quantities of exhaust air, high and strongly fluctuating solvent concentrations and solvent mixtures such as those occurring in batch operation. A washing agent was employed which had not been previously used for this purpose. Its properties, which were investigated in the laboratory, were confirmed during a 15‐months' trial period in a semi‐industrial plant. The process and plant were optimized for practical use. Through its option of solvent recovery from exhaust air, this physical absorption process contributes to environmental control.