bluuebunny/crossref_metadata_2025_split huggingface dataset:
A theoretical and experimental investigation of fiber suspension drainage in the turbulent regime: Part 1: Presentation of a new theory for the turbulent drainage of fiber suspensions
Authors: Meadley C. K. 
Published: February 2011

AbstractA brief literature review, covering most of the major studies of fiber suspension drainage is given and it is found that a basic knowledge of the process is lacking when the flow is predominantly turbulent. The conventional viscous flow model of drainage is summarized for comparison purposes, and then a new theory, derived for the purpose of predicting fiber suspension drainage properties in the turbulent regime as a function of fiber, fiber mat and machine characteristics, is presented and discussed.A theoretical model of turbulent drainage is adopted, for which it is assumed that pressure drops arise predominantly due to turbulent dissipation rather than to viscous shear stress losses, and for which the resistance is proportional to the square of the drainage rate. A turbulent resistance function is thus formulated, relating drainage resistance characteristics to certain basic fiber and fiber mat properties and involving two general parameters, which remain to be evaluated experimentally. Use of this resistance function with the appropriate equation of motion for the drainage mechanics results in formulae for the calculation of drainage profiles and properties for various machine conditions.
Absorption of carbon dioxide by aqueous ammonia in a packed tower
Authors: Vassilatos G. , Trass O. , Johnson A. I. 
Published: February 2011

AbstractNew data were obtained for absorption of carbon dioxide from an air‐carbon dioxide mixture by aqueous ammonia solutions in a tower packed with 1/2 in. Raschig rings. The rates of absorption of carbon dioxide, expressed as over‐all volumetric coefficients KGa, were correlated with the ammonia concentration and the liquid flow rate.The data were analyzed in the light of the film, penetration and Kishinevsky theories for absorption with simultaneous chemical reaction. Effective interfacial areas, calculated from the data with the aid of the first two theories, were reasonable, and three to four times larger than the corresponding areas for pure physical absorption or vaporization under the same hydrodynamic conditions. Distinction between the two theories was not possible because, for the present system, both give nearly the same results. Results from Kishinevsky's theory were quite unreasonable.
Phase inversion in the mixing of immiscible liquids
Authors: Quinn J. A. , Sigloh D. B. 
Published: February 2011

AbstractData are reported on phase inversion in concentrated oil‐water mixtures dispersed in a fully‐baffled stirred tank. The results indicate that water continuous dispersions in which the water concentration is as small as 40% by volume can be formed.For a vertically centered impeller the concentration of the organic liquid required for phase inversion varies inversely with the rate of energy input. The effect of impeller position is also discussed.
Latent heat of vaporization of 1‐pentene
Authors: Cuffel R. F. , Kozicki William , Sage B. H. 
Published: February 2011

AbstractThe enthalpy change upon vaporization of l‐pentene was experimentally determined by calorimetric measurements at temperatures between 100° and 280°F. The results are in good agreement with available data at the lower temperatures and are presented in graphical and tabular form.
The gravity approach and coalescence of fluid drops at liquid interfaces
Authors: Mackay G. D. M. , Mason S. G. 
Published: February 2011

AbstractThe rate of thinning of the liquid film trapped between a fluid drop and a liquid interface and the subsequent coalescence of the drop were investigated using an interferometric method. The rate of film thinning for small drops was in good agreement over a narrow range of film thickness with two previously proposed models. The rate was greater than predicted when the film thickness was less than 0.2 μ presumably because of movement of the interfaces. The minimum thickness in the film at rupture was usually less than 500 Å. for drop diameters up to 2500 μ. The seemingly anomalous behavior of drops previously observed in a partial coalescence series resulted from uneven film thinning with larger drops. Partial coalescence between finite drops was investigated briefly; no secondary drop was produced when the drop diameter ratio was less than about 3.5.
The effect of acoustic turbulence on mass transfer at a column wall
Authors: Low D. I. R. , Hodgins J. W. 
Published: February 2011

AbstractMeasurements have been made of the mass transfer of naphthalene into an air stream in the presence of a standing sound wave propagated parallel to the surface. The flowrate range of the air stream was from Re = 100 to Re = 14,000. Concentration of the ablated naphthalene in the effluent air was measured by ultraviolet spectrophotometry.At the antinode for resonant frequency of 286 cps and a sound intensity of 154 db, mass transfer enhancement occurs at flowrates up to Re = 8,000; this enhancement is as large as 180% at low flows. The enhancement increases with sound intensity, and decreases with increasing frequency.At the node, the mass transfer was reduced in proportion to the intensity. The sound flux changes both concentration and velocity profiles in the column, probably by alteration of the boundary layer. Mass transfer enhancement appears to be a function of the ratio of oscillating velocity to superficial mean velocity. The significance of oscillation amplitude in the enhancement of mass transfer is established.
Temperature distribution and heat transfer in annular two‐phase (liquid‐liquid) flow
Authors: Bentwicw M. , Sideman S. 
Published: February 2011

AbstractAn analysis of the temperature distribution in a laminar annular two‐phase liquid‐liquid flow inside a semi‐infinite circular pipe is given. Graetz's general approach is adopted here so that the arbitrary temperature distribution at the inlet of the pipe is expressed by a series of eigenfunctions. The discontinuities in the physical properties of the fluids at their interface are accommodated by utilizing Graetz's method in a modified form.Attention is focused on the case where the less viscous fluid forms a thin annular film adjacent to the wall. It is shown that in order to heat a viscous oil it is more effective to allow the oil to flow inside a thin water annulus. As compared with the usual method of fuel oil heating, the system proposed has the advantages of improved surface conductivity as well as a reduced pressure gradient (due to the reduced viscosity of the water layer).
Heat transfer in spouted beds
Authors: Malek M. A. , Lu B C.‐Y. 
Published: February 2011

AbstractBed to wall heat transfer in spouted beds has been investigated in vertical 6‐ and 3‐in. columns using polyethylene, polystyrene, wheat, rice, millet, Timothy seeds or Ottawa sands as the bed material.Measurements indicate that the heat transfer coefficient, h, increases with increasing mass velocity of the air, G, up to the point of spouting. During spouting, h is independent of G, the column diameter and the orifice diameter, but increases with increasing diameter and heat capacity of the particles, and decreases with increasing bed height. The value of h varies from 10 to 24 Btu./(hr.) (sq.ft.) (°F.). A dimensional analysis has been used to correlate the data.Under similar conditions, h is from 10 to 66% lower for a spouted bed than for a fluidized bed, but G required for spouting varies from 35 to 55% of that for obtaining the maximum heat transfer in a fluidized bed.
The pipeline flow of capsules part 4 ‐ an experimental investigation of the transport in water of single cylindrical “capsules” with density greater than that of the water
Authors: Ellis H. S. 
Published: February 2011

AbstractThe last paper in this capsule pipelining series described investigations of the flow of equal‐density capsules transported by water in a horizontal pipe. In the present study, attention was directed to the flow of capsules with specific gravities in the range of 1.19 to 8.30. As before, capsules were used with diameter ratios of 0.39 to 0.89, and length to diameter ratios of 2 to 14, both flat and ellipsoidal end shapes being included.With water velocities greater than about 3 ft./sec., the larger diameter capsules moved at velocities up to 15% greater than the average water velocity, the actual values depending mainly on the capsule diameter and density. The velocity ratio, capsule velocity/‐average water velocity, typically increased with either increase of diameter or decrease of density, other factors being constant.Longer capsules moved more slowly than shorter ones of the same diameter and density at low water velocities, but the velocity ratio of the longer capsules increased more rapidly than that of the shorter capsules at higher water velocities. An ellipsoidal nose materially increased the velocity of smaller diameter capsules but the effect on the largest diameter capsules was small.The reduction of the effects of density and surface roughness at the higher capsule velocities suggests the formation of a thickening film of water under the capsule as its velocity increases.
Direct‐contact heat transfer between a single drop and an immiscible liquid medium
Authors: Sideman S. , Shabtai H. 
Published: February 2011

AbstractRelations describing heat transfer to a fluid drop moving freely in an immiscible continuous medium are reviewed, with analogous mass transfer information included. Theoretical and experimental equations for determining inside and outside transfer coefficients are presented for the three most common models, i.e. a rigid drop, a completely mixed drop, and a drop with internal circulation. The important equations are tabulated for easy reference. The effect of temperature gradients in the continuous medium, drop size and various end effects are also discussed.
Phase behavior of the n‐butane‐hydrogen sulphide system
Authors: Robinson Donald B. , Hughes R. E. , Sandercock J. A. W. 
Published: February 2011

AbstractPrevious work on binary and multicomponent systems containing hydrogen sulphide or n‐butane is briefly reviewed and the anomolous behavior of the hydrogen sulphide with hydrocarbons and of the n‐butane with non hydrocarbons is noted.Experimental equipment suitable for studying the phase behavior of simple or complex mixtures is described. The novel features include a new method for obtaining equilibrium between phases, for sampling, and for locating the meniscus between phases.Experimental data have been obtained for the n‐butane‐hydrogen sulphide system at seven temperatures between 100°F. and 275°F. and pressures up to 1165 p.s.i.a. A tendency toward azeotropic behavior was observed but an azeotrope was never fully developed.Equilibrium ratios for hydrogen sulphide and n‐butane were calculated at convergence pressures of 1000 p.s.i.a. at 240°F. and 800 p.s.i.a. at 275°F. The results agreed well with those determined from generalized correlations. It is concluded that the presence of hydrogen sulphide does not influence the behavior of n‐butane abnormally at the temperatures and pressures studied.
Some observations on tubular reactor stability
Authors: Raymond Lee R. , Amundson Neal R. 
Published: February 2011

AbstractFollowing van Heerden, it has been shown that the adiabatie empty tubular reactor in which an exothermic chemical reaction is carried out may exhibit multiple temperature and concentration profiles along its axis. The existence of these multiple steady states may be predicted from a steady state analysis alone. Whether these steady states are stable in the sense that a given state is restored when slightly perturbed cannot be determined by a rational analysis since the prerequisite mathematical apparatus is not available. A transient analysis of the full non‐linear equations shows that some states may be unstable.
Kinetics of the reduction of ferrous chloride with hydrogen
Authors: Rigg Tyson 
Published: February 2011

AbstractThe reduction of ferrous chloride with hydrogen at atmospheric pressure has been investigated at temperatures up to 583°C. The results show that the reaction rate is limited by the rate of diffusion of hydrogen chloride produced in the reaction. At constant temperature the rate is proportional to the difference between the equilibrium partial pressure and the back pressure of hydrogen chloride. The reaction rate has a strong dependence on temperature, corresponding to an “apparent activation energy” of 19.9 K. cal./mole. A reaction mechanism involving vaporization of ferrous chloride is suggested.
Chemical sampling as a data filter
Authors: Coulman George A. 
Published: February 2011

AbstractChemical processes are generally required to use sampled data. By the nature of the sampling method, differences exist between the known sample data theory and that related to chemical processes.Taking a sample from a chemical process stream really measures the weighted mean. The frequency filtering effect of this sampling is analyzed. The significant parameters and their effects are pointed out. Several weighting functions are evaluated and the relative values discussed.A continuous stirred tank reactor system is analyzed. The responses to the actual signal and the sampled signal are compared. This points out the validity of this method for use in a predictor model reference control system for example.
Thermal barriers for rocket motors
Authors: Belanger J. Y. 
Published: February 2011

AbstractThe very high temperatures associated with rocket motors have necessitated the development of new materials and techniques for thermally insulating various rocket components. Refractory fibres, in combination with heat resistant resins, have proven to be most promising. Composite materials such as metal‐ceramic combinations have also been used to meet the needs of special applications. Techniques developed at the Canadian Armament Research and Development Establishment for using these new materials in a 17‐inch diameter solid propellant rocket motor are described in detail.
Three‐stage multiphase‐switched‐capacitor boost DC‐AC inverter
Authors: Chang Yuen‐Haw , Luo Zih‐Yao 
Published: February 2011

SUMMARYA closed‐loop scheme of a three‐stage multiphase‐switched‐capacitor boost DC‐AC inverter (MPSCI) is proposed by combining the multiphase operation and sinusoidal‐pulse‐width‐modulation (SPWM) control for low‐power step‐up DC‐AC conversion and regulation. In this MPSCI, the power unit contains two parts: MPSC booster (front) and H‐bridge (rear). The MPSC booster is suggested for an inductor‐less step‐up DC‐DC conversion, where three voltage doublers in series are controlled with multiphase operation for boosting voltage gain up to 23= 8 at most. The H‐bridge is employed for DC‐AC inversion, where four solid‐state switches in H‐connection are controlled with SPWM to obtain a sinusoidal AC output. In addition, SPWM is adopted for enhancing output regulation not only to compensate the dynamic error, but also to reinforce robustness to source/loading variation. The relevant theoretical analysis and design include: MPSCI model, steady‐state/dynamic analysis, voltage conversion ratio, power efficiency, stability, capacitance selection, total harmonic distortion (THD), output filter, and closed‐loop control design. Finally, the closed‐loop MPSCI is simulated, and the hardware circuit is implemented and tested. All the results are illustrated to show the efficacy of the proposed scheme. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of all‐syn Functionalized Triphenylene Ketals
Authors: Boshta Nader M. , Bomkamp Martin , Schnakenburg Gregor , Waldvogel Siegfried R. 
Published: February 2011

AbstractThe stereoselective synthesis of triphenylene ketals offers access to unique scaffolds. For a good performance in supramolecular applications an all‐syn orientation of the functional groups is essential. The oxidative trimerization of catechol ketals by molybdenum pentachloride or mixtures with titanium tetrachloride leads to a template‐directed formation. Several heterocyclic moieties are suitable for this transformation. A template‐directed isomerization of anti,anti,syn isomers to the desired C3‐symmetric derivative was demonstrated in two cases.
Acute toxicity, histopathology, and coagulopathy in American kestrels (Falco sparverius) following administration of the rodenticide diphacinone
Authors: Rattner Barnett A , Horak Katherine E , Warner Sarah E , Day Daniel D , Meteyer Carol U , Volker Steven F , Eisemann John D , Johnston John J 
Published: February 2011

Abstract
The acute oral toxicity of the anticoagulant rodenticide diphacinone was found to be over 20 times greater in American kestrels (Falco sparverius; median lethal dose 96.8 mg/kg body weight) compared with Northern bobwhite (Colinus virginianus) and mallards (Anas platyrhynchos). Modest evidence of internal bleeding was observed at necropsy, although histological examination of heart, liver, kidney, lung, intestine, and skeletal muscle revealed hemorrhage over a wide range of doses (35.1–675 mg/kg). Residue analysis suggests that the half-life of diphacinone in the liver of kestrels that survived was relatively short, with the majority of the dose cleared within 7 d of exposure. Several precise and sensitive clotting assays (prothrombin time, Russell's viper venom time, thrombin clotting time) were adapted for use in this species, and oral administration of diphacinone at 50 mg/kg increased prothrombin time and Russell's viper venom time at 48 and 96 h postdose compared with controls. Prolongation of in vitro clotting time reflects impaired coagulation complex activity, and generally corresponded with the onset of overt signs of toxicity and lethality. In view of the toxicity and risk evaluation data derived from American kestrels, the involvement of diphacinone in some raptor mortality events, and the paucity of threshold effects data following short-term dietary exposure for birds of prey, additional feeding trials with captive raptors are warranted to characterize more fully the risk of secondary poisoning. Environ. Toxicol. Chem. 2011; 30:1213–1222. © 2011 SETAC
A Lagrangian approach to modelling stable isotopes in precipitation over mountainous terrain
Authors: Sinclair K. E. , Marshall S. J. , Moran T. A. 
Published: February 2011

AbstractA Lagrangian (Rayleigh) distillation model is used to track the evolution of stable isotopes in precipitation over mountainous terrain from the Pacific Coast of Canada to two alpine field sites in the Canadian Rocky Mountains. Precipitation δ18O at Vancouver constrains the model and air–mass back trajectories provide the water vapour pathway for 10 winter storm events. Isotopic values along storm pathways are modelled with a classical Rayleigh model that prescribes a linear decrease in temperature and pressure from initial to final conditions, and two models that account directly for orographic precipitation processes by: (i) applying an orographic rainfall model and (ii) using North American Regional Reanalysis data to calculate the change in vapour content along storm pathways. All models are significant predictors of snowpack δ18O, but the orographic model provides the best fit to precipitation‐weighted δ18O for each storm. The improvement in modelled δ18O by accounting for terrain along storm trajectories illustrates the need to account for orographically driven moisture loss when modelling vapour transport to ice core sites with mountainous upwind terrain. This finding is also applicable to isotopic studies of paleoaltimetry and source areas of groundwater recharge. Copyright © 2011 John Wiley & Sons, Ltd.
Spatial and temporal variations of precipitation in Haihe River Basin, China: six decades of measurements
Authors: Wang Zhonggen , Luo Yuzhou , Liu Changming , Xia Jun , Zhang Minghua 
Published: February 2011

AbstractThis study aims to determine temporal trends and spatial distribution of the annual and monthly precipitation in the Haihe River Basin, China, during 1951–2008. A significant decreasing trend was observed for the annual precipitation, mainly attributed to the abrupt decrease in the flood‐season precipitation (June–September) around the year of 1979. No significant trend was revealed for precipitation within Period I of 1951–1979 and Period II of 1980–2008. Results of this study indicated that the relative contributions of the flood‐season precipitation decreased temporally with time and spatially with elevation. This study also identified a potential movement of storm centers from east to west portions of the basin. In addition, analysis on the precipitation anomalies also suggested a redistribution of the non‐flood season precipitation over the study area. Compared with the west portion of the basin, generally, the east received relatively more precipitation during the non‐flood season, while similar trend of precipitation redistribution was not observed in the flood season. Copyright © 2011 John Wiley & Sons, Ltd.
Chemical synthesis of allyl‐[13C6]‐glucuronate
Authors: Latli Bachir , Hrapchak Matt , Seetharama Ravikumar , Krishnamurthy Dhileepkumar , Senanayake Chris H. 
Published: February 2011

AbstractThe synthesis of allyl‐[13C6]‐glucuronate from α‐D‐[13C6]‐glucose in five steps is described. Selective protection of the primary alcohol in the glucose with the bulky trityl group followed by acetylation in the same pot gave the fully protected sugar. Removal of the trityl group followed by oxidation of the primary alcohol to the acid and removal of the acetate groups using catalytic amounts of sodium methoxide gave the glucuronic acid. Reaction with allyl bromide using resin‐bound fluoride gave the title compound. Copyright © 2011 John Wiley & Sons, Ltd.
Image‐guided methods for biopsy of suspicious breast lesions
Authors: Vandromme Marianne J. , Umphrey Heidi , Krontiras Helen 
Published: February 2011

AbstractThe widespread use of breast imaging has resulted in the increased detection of clinically occult suspicious breast lesions. Between 1999 and 2004 the number of breast biopsies in the United States has increased steadily. The armamentarium of methods to biopsy suspicious breast lesions has also increased significantly since the early 1990s with technological advancements for both surgical breast biopsy and percutaneous image guided breast biopsies. J. Surg. Oncol. 2011; 103:299–305. © 2011 Wiley‐Liss, Inc.
New legislation affecting us nonprofits
Authors: Adler Betsy Buchalter 
Published: February 2011

AbstractIn the summer of 1996, Congress passed and the President signed, four pieces of legislation of significance to the nonprofit sector: the Taxpayers Bill of Rights 2 (TBR2), the Small Business Job Protection Bill of 1996 (Small Business Act), the Health Insurance Portability and Accountability Act of 1996, and the Personal Responsibility and Work Opportunity Reconciliation (Welfare Reform) Act of 1996. Taken together, these four laws contain what are perhaps the most significant changes to the Internal Revenue Code since the Tax Reform Act of 1986, and what are certainly the most profound changes in the rules affecting tax‐exempt organisations since the enactment of the 1969 legislation governing private foundations. This paper highlights the most significant features of these laws as they affect nonprofits.1
Women as philanthropists: Leading the transformation of fundraising
Authors: Taylor Martha A. , Kaminski Andrea R. 
Published: February 2011

AbstractThis paper provides an overview of women's motivations and potential as philanthropists. It includes demographic information that can help fundraisers approach and communicate with women of different generations and life stages. The conclusions are based on qualitative research conducted by the author and others. It explores some of the barriers to women's giving and offers specific recommendations for involving more women as donors. Finally, it explains how women as donors will help transform the fundraising profession and prepare nonprofit institutions for a changed funding environment in the future.