McGraw-Hill Book Company Research Articles

Completion Posterior Quadrant Disconnection After Failed Temporal Lobectomy: 2-Dimensional Operative Video

Epilepsy is a chronic seizure disorder that affects about 1% of the global population.1 When seizure freedom cannot be obtained solely through antiseizure medicines (ASMs), the condition is termed medically refractory epilepsy (MRE).2,3 Though posterior quadrant disconnection (PQD) is underutilized in our experience, it is a highly effective surgical procedure for MRE restricted to the temporal, parietal, and/or occipital lobes.4-12 In this operative video, we demonstrate a right-sided completion PQD following failed temporal lobectomy in an 8-yr-old female with focal MRE. We review technical nuances, including (1) extension/revision of prior scalp incision, (2) placement of subdural strip for the identification of phase reversal and central sulcus, (3) disconnection of parietal and occipital lobes, (4) extension of the corticectomy to the pia overlying the falcotentorial junction and into the prior temporal lobectomy defect, and (5) posterior disconnection of the corpus callosum. Postoperatively, the patient experienced subtle left-arm weakness and central fever, both of which resolved. An external ventricular drain (EVD) was placed in the ventricle/operative cavity and left for 3 to 4 d until the draining cerebrospinal fluid (CSF) cleared. As of 3-mo follow-up, she has been seizure-free without complications. In summary, PQD is a safe and effective treatment option for MRE that can be utilized not only as an initial operation but also after failed surgery. Appropriate patient consent was obtained to perform this procedure and present this clinical case and surgical video for academic purposes. Image at 4:00 licensed under CC BY-2.5, 2006, modified from http://upload.wikimedia.org/wikipedia/commons/7/70/Lateral_head_skull.jpg (flipped and rotated). Image at 4:42, Public Domain: Gray H. Anatomy of the Human Body. 1918. Bartleby.com, https://commons.wikimedia.org/wiki/File:Lobes_of_the_brain_NL.svg; flipped, modified. Image at 6:42, Public Domain: House EL, Pansky B. A Functional Approach to Neuroanatomy. 1960. McGraw-Hill Book Company; https://upload.wikimedia.wikipedia.commons/5/52/Lawrence_1960_2.3.png; modified.

The quantum and electromagnetic process of photon emission by the hydrogen atom

Light emitted from atoms during transitions of electrons from higher to lower discrete states has the form of photons carrying energy and angular momentum. This paper considers the process of emission of a single photon from the hydrogen atom by using quantum theory and Maxwell's equations [W. Gough, Eur. J. Phys. 17, 208, 1996; L. D. Landau and E. M. Lifshitz, Quantum Mechanics (Pergamon Press, Oxford, 1965); J. D. Jackson, Classical Electrodynamics (John Wiley & Son, New York, 1975, 1982); P. M. Morse and H. Feshbach, Methods of Theoretical Physics (McGraw-Hill Book Company, Inc., New York, 1953)]. The electric and magnetic fields of a photon arise from the time-dependent quantum probability densities of the orbit and the spin current. This paper is an extension of the semiclassical description of photon emission published by the author earlier in 1999 [M. Kowalski, Phys. Essays 12, 312 (1999)]. In the semiclassical approach, the Coulomb force and a radiation resistance force have been taken into account to get time-dependent emission of the photon. In both the quantum and semiclassical cases, the transition takes place within a time interval equal to one period of the photon's wave. The creation of a one-wavelength-long photon is supported by the results of experiments using ultrafast (ultrashort) laser pulses to generate excited atoms, which emit light pulses shorter than two photon wavelengths [F. Krausz and M. Ivanov, Rev. Mod. Phys. 81, 163 (2009); H. Kapteyn and M. Murnane, Phys. World 12, 31 (1999)].

Understanding Lewis activities

The notion of activity is of a purely thermodynamic nature. It is intimately linked to the law of mass action and more generally to that of equilibrium constant. It was conceived and introduced in the realm of chemistry at the beginning of twentieth century by Lewis (Proc Am Acad Arts Sci 37:49‒69, 1901; Proc Am Acad Arts Sci 43:259‒293, 1907; J Am Chem Soc 30:668‒683, 1908) and Lewis and Randall (Thermodynamics and the free energy of chemical substances. McGraw-Hill Book Company, London, 1923). Its introduction permits us to overcome insuperable theoretical and practical difficulties encountered in chemistry, physics and biochemistry with great ease. Before discussing the notion of activity, it is necessary to introduce ideal and non-ideal chemical systems, the different scales of unities permitting one to express their composition and the concept of chemical potential. Here, we seek to locate the notion of activity within the framework of classical thermodynamics. We shall see that its introduction in chemistry enables us to generalize the use of the Gibbs energy function (formerly, and still in German, called the free enthalpy function) for introducing the concept of chemical equilibrium. This is carried out by the introduction of the pivotal function known as chemical potential. Then, we set out the interest that represents the handling of activities. It, purely and simply, permits one to formulate the mass action law when the studied chemical systems are not ideal. This is the vast majority of cases! This is followed by introducing the notions of fugacity and activity from a general viewpoint. We then confine ourselves to the study of the activity of gases, those of non-electrolytes in liquid solutions, the activities of electrolytes, the determination of activities of non-electrolytes and of electrolytes, calculation of activities of electrolytes essentially with the aid of Debye–Huckel relations and that of activity coefficients and activities, their relations with another thermodynamic function, that is to say the excess Gibbs energy, the determination of pH of an aqueous solution, the general principles of calculations involving activities in solutions, and finally, the determination of thermodynamic equilibrium constants of polyfunctional compounds.

Wild Flowers of the United States: Volume 1, The North-Eastern States (in two parts). Harold William Rickett. New York: McGraw-Hill Book Company, 1966. x, 559 pp. $39.50.

Wild Flowers of the United States: Volume 1, The North-Eastern States (in two parts). Harold William Rickett. New York: McGraw-Hill Book Company, 1966. x, 559 pp. $39.50.

In Memoriam: Dr. Clive L. Dym (1942–2016)

In Memoriam: Dr. Clive L. Dym (1942–2016)

External morphology of the eggs of Asplanchnopus multiceps (Schrank, 1793) (Rotifera): solving the 150-year-old case of mistaken identity

This report calls into question the practice of passing along illustrations and anatomical descriptions from the literature without scrutiny. An error made by Leydig (Zeischrift fur wissenschaftliche Zoologie 6:1–120, 1854) in characterizing the egg of Asplanchnopus multiceps was perpetuated in authoritative publications (Hyman, The Invertebrates: Acanthocephala, Aschelminthes, and Entoprocta. The pseudocoelomate Bilateria, McGraw-Hill Book Company, New York, 1951; Voigt, Rotatoria: Die Radertiere Mitteleuropas, Gebruder Borntraeger, Berlin-Nikolassee, 1957; Ruttner-Kolisko, Plankton rotifers, biology and taxonomy supplementary edition of Die Binnengewasser 26, Stuttgart, 1974; Koste, Rotatoria: Die Radertiere Mitteleuropas begrundet von Max Voigt. Monogononta 2. Auflage neubearbeitet von Walter Koste, Gebruder Borntraeger, Berlin, 1978; Mikrokosmos 76:171–175, 1987) well into the twentieth century. Daily tracking of individual mictic and amictic female A. multiceps demonstrates that the structure formerly considered to be a diapausing egg is, in fact, subitaneous. It develops without arrest into a male or female rotifer. True resting eggs containing dormant embryos are characterized by a very dark interior. In the majority of these eggs, the interior is surrounded by a halo-like zone consisting of a clear space and an external layer. The correct identification of subitaneous and resting eggs in A. multiceps confirms the description of Plate (Jenaische Zeitschrift fur Naturwissenschaft 19:1–120, 1885) and firmly establishes the mode of reproduction of this species as oviparous. Mictic females lay haploid male eggs first, followed by resting eggs if fertilization has taken place. In the absence of fertilization, mictic females lay significantly more (male) eggs than amictic females lay female eggs; however, their lifespan does not differ markedly.

GIS based quantitative morphometric analysis and its consequences: a case study from Shanur River Basin, Maharashtra India

A morphometric analysis of Shanur basin has been carried out using geoprocessing techniques in GIS. These techniques are found relevant for the extraction of river basin and its drainage networks. The extracted drainage network was classified according to Strahler’s system of classification and it reveals that the terrain exhibits dendritic to sub-dendritic drainage pattern. Hence, from the study, it is concluded that remote sensing data (SRTM–DEM data of 30 m resolution) coupled with geoprocessing techniques prove to be a competent tool used in morphometric analysis and evaluation of linear, slope, areal and relief aspects of morphometric parameters. The combined outcomes have established the topographical and even recent developmental situations in basin. It will also change the setup of the region. It therefore needs to analyze high level parameters of drainage and environment for suitable planning and management of water resource developmental plan and land resource development plan. The Shanur drainage basin is sprawled over an area of 281.33 km2. The slope of the basin varies from 1 to 10 %, and the slope variation is chiefly controlled by the local geology and erosion cycles. The main stream length ratio of the basin is 14.92 indicating that the study area is elongated with moderate relief and steep slopes. The morphometric parameters of the stream have been analyzed and calculated by applying standard methods and techniques viz. Horton (Trans Am Geophys Union 13:350–361, 1945), Miller (A quantitative geomorphologic study of drainage basin characteristics in the clinch mountain area, Virginia and Tennessee Columbia University, Department of Geology, Technical Report, No. 3, Contract N6 ONR 271–300, 1953), and Strahler (Handbook of applied hydrology, McGraw Hill Book Company, New York, 1964). GIS based on analysis of all morphometric parameters and the erosional development of the area by the streams has been progressed well beyond maturity and lithology is an influence in the drainage development. These studies are very useful for planning of rainwater harvesting and watershed management.

"I Want to Pump You Up!" Lance Armstrong, Alex Rodriguez, and the Biopolitics of Data- and Analogue-Flesh

"I Want to Pump You Up!" Lance Armstrong, Alex Rodriguez, and the Biopolitics of Data- and Analogue-Flesh

Toward a Composite Measure of Green Consumption: An Exploratory Study Using a Korean Sample

This study developed a composite measure of green consumption behaviors, incorporating multiple dimensions of green consumption behaviors. As a result of an extensive literature review, four value orientations were proposed: health-related egoistic value orientation, resource-related egoistic value orientation, altruistic value orientation, and biospheric value orientation. And a composite measure of green consumption which measured green consumption behavior manifesting the suggested value orientations were proposed and empirically tested using a Korean sample. After empirical testing and validating the proposed composite measure according to the measurement validation procedure proposed by Nunnally (New York: McGraw-Hill Book Company, 1978), the composite measure of green consumption behaviors was revised to three dimensions of green consumption behaviors: health-conscious green consumption behavior, resource-conscious green consumption behavior, and socially conscious green consumption behavior that combined originally suggested altruistic and biospheric value orientations. A multivariate regression analysis was employed to test the usability of the composite measure of green consumption behaviors and to identify the determinants of green consumption behaviors. As hypothesized, the results of regression analysis showed that perceived consumer effectiveness, reference persons, and perceived market situation are significant determinants of green consumption behaviors, and the effects of environmental concern and socioeconomics are limited. Based on these findings, public policy and marketing implications that promote green consumption are also proposed.

Foam flowing vertically upwards in pipes through expansions and contractions

The drift-flux analysis of one-dimensional two-phase flow of Wallis (Wallis, G.B., 1969. One-dimensional two-phase flow. McGraw-Hill Book Company, New York.) is utilised for the first time to model the behaviour of pneumatic foam flowing vertically through an expansion or an contraction. It is demonstrated that, although a sudden contraction of flow area decreases the liquid fraction, it does not affect the volumetric liquid over-flow rate. It is also demonstrated that a sudden expansion of flow area decreases both the liquid fraction and the volumetric liquid over-flow rate. The liquid fraction of a foam stabilised by 2.92 g/L sodium dodecyl sulphate (SDS) solution flowing through a sudden contraction or expansion was measured by an improved pressure gradient method. The results were found to be consistent with the theoretical analysis. This study has implications for foam fractionation device design, optimisation and process intensification.

Internal Medicine Residency Training on Topics in Ambulatory Care: A Status Report

Internal Medicine Residency Training on Topics in Ambulatory Care: A Status Report

Applications of adjoint theory to problems in aerospace and defence science

The adjoint simulation method is an efficient, computerised method for the performance analysis of linear time varying systems excited by deterministic and/or stochastic inputs. It is based on the impulse response function (or weighting function) of the so-called adjoint system---an associated linear system derived from the original system by clever utilisation of the mathematical principle of duality. We demonstrate the power of adjoint simulation in the context of guided missile homing loop studies and present a Matlab tool for its speedy implementation and execution. As an example, the tool analyses the miss distance performance of a generic guided missile against an evading target in two dimensional space. References Statistical performance analysis of nonlinear stochastic systems by the Monte Carlo method volume 23-1 of Mathematics and Computers in Simulation J. , pages 21--23, 1981. doi:10.1016/0378-4754(81)90004-5 Zarchan, P. Tactical and Strategic Missile Guidance , 5th Edition, AIAA Progress in Astronautics and Aeronautics, 2007. Weiss, M. Adjoint Method for Missile Performance Analysis on State-Space Models, volume 28-2 of Guidance, Control and Dynamics J. , pages 236--248, AIAA ,2005. Laning, J. H. and Battin, R. H. Random Processes in Automatic Control , McGraw-Hill Book Company, New York, NY, 1956. D. Bucco and M. Weiss. Development of a Matlab/Simulink Tool to Facilitate System Analysis and Simulation via the Adjoint and Covariance Methods, AIAA MST Conference , Aug 2007. http://www.aiaa.org/agenda.cfm?lumeetingid=1501&formatview=1&dateget=22-Aug-07 DeRusso, P. M., Roy, R. J., Close, C. M., and Desrochers, A. A. State Variables for Engineers, 2nd Edition , John Wiley and Sons, Inc., New York, NY, 1998. Moretti, G. Best Practices for Adopting Model-Based Design in Electronic System Development, White-paper, Gabe on EDA , 2007. http//www.mathworks.com/products/simulink/technicalliterature.html

A Neural Circuit Mechanism Integrating Motivational State with Memory Expression in Drosophila

Behavioral expression of food-associated memory in fruit flies is constrained by satiety and promoted by hunger, suggesting an influence of motivational state. Here, we identify a neural mechanism that integrates the internal state of hunger and appetitive memory. We show that stimulation of neurons that express neuropeptide F (dNPF), an ortholog of mammalian NPY, mimics food deprivation and promotes memory performance in satiated flies. Robust appetitive memory performance requires the dNPF receptor in six dopaminergic neurons that innervate a distinct region of the mushroom bodies. Blocking these dopaminergic neurons releases memory performance in satiated flies, whereas stimulation suppresses memory performance in hungry flies. Therefore, dNPF and dopamine provide a motivational switch in the mushroom body that controls the output of appetitive memory.

Subordination to periodic processes and synchronization

We study the subordination to a process that is periodic in the natural time scale, and equivalent to a clock with N states. The rationale for this investigation is given by a set of many interacting clocks with N states. The natural time scale representation corresponds to the dynamics of an individual clock with no interaction with the other clocks of this set. We argue that the cooperation among the clocks of this set has the effect of generating a global clock, whose times of sojourn in each of its N states are described by a distribution density with an inverse power law form and power index μ < 2 . This is equivalent to extending the widely used subordination method from fluctuation–dissipation processes to periodic processes, thereby raising the question of whether special conditions exist of perfect synchronization, signaled by regular oscillations, and especially by oscillations with no damping. We study first the case of a Poisson subordination function. We show that in spite of the random nature of the subordination method the procedure has the effect of creating damped oscillations, whose damping vanishes in the limiting case of N ≫ 1 , thereby suggesting a condition of perfect synchronization in this limit. The Bateman’s mathematical arguments [H. Bateman, Higher Transcendental Functions, vol. III, Robert K Krieger, Publishing Company, Inc. Krim.Fr. Drive Malabar, FL; Copyright 1953 by McGraw-Hill Book Company Inc.] indicate that the condition of perfect synchronization is possible also in the non-Poisson case, with μ < 2 , although it may lie beyond the range of computer simulation. To make the theoretical predictions accessible to numerical simulation, we use a subordination function whose survival probability is a Mittag–Leffler exponential function. This method prevents us from directly establishing the macroscopic coherence emerging from μ = 2 , which generates a perfect form of 1 / f noise. However, it affords indirect evidence that perfect synchronization signaled by undamped regular oscillations may be produced in this case. Furthermore, we explore a condition characterized by an excellent agreement between theory and numerical simulation, where the long-time region relaxation, with a perfect inverse power law decay, emerging from the subordination to ordinary fluctuation–dissipation processes, is replaced by exponentially damped regular oscillations.

High temperature strength and failure of the Ni-base superalloy PM 3030

The strength, fatigue life and fracture behavior of the oxide dispersion strengthened (ODS) nickel-base superalloy PM 3030 are investigated. The high Al content in PM 3030 leads to the formation of coherent γ′ particles and, thus, to additional precipitation strengthening. A coarse and elongated grain structure (R34) and two isotropic batches with mean grain sizes of 1 μm (R90) and 17 μm (R901315) are considered. Compressive constant strain rate tests and high cycle fatigue (HCF) tests are performed. Optical, scanning and transmission electron microscopy (OM, SEM and TEM) are carried out. The properties are compared with those of the solely oxide dispersion strengthened Ni-base alloy PM 1000 [Estrin, Y., Heilmaier, M., Drew, G., 1999. Creep properties of an oxide dispersion strengthened nickel-base alloy: the effect of grain orientation and grain aspect ratio. Mater. Sci. Eng. A 272(1), 163–173]. It is found that additional γ′ hardening provides an increase in quasi-static strength by about a factor 2 and in HCF life by about a factor 10 2–10 3 at temperatures up to 850 °C. When fatigue life is compared at a fixed ratio of stress amplitude-to-yield or ultimate compressive strength, R34 shows a fatigue life similar to that of PM 1000 at lower temperature (e.g. 600 °C) indicating that the quasi-static strength advantage is proportionally translated into improved fatigue performance; for higher temperatures (850 °C) however, R34 shows a shorter fatigue life as compared to PM 1000. Grain size reduction, as exemplified with the fine grain R90 batch, also provides an increase in strength up to the equicohesion temperature ( T E) [Dieter, G.E., 1986. Mechanical Metallurgy. SI Metric ed. McGraw-Hill Book Company, London]. Above T E, faster diffusion and grain boundary sliding [Raj, R., Ashby, M.F., 1971. On the grain boundary sliding and diffusional creep. Metall. Trans. 2, 1113–1127; Spingarn, J.R., Nix, W.D., 1978. Diffusional creep and diffusionally accommodated grain rearrangement. Acta Metall. 26, 1389–1398] lead to a drastic drop in strength for the R90 material. In contrast, the batch with intermediate grain size (R901315) shows strength comparable to that of R34 up to 850 °C. Furthermore, R901315 shows improved crack tolerance compared to its coarse grain counterpart R34. Due to premature crack initiating coarse oxide particles however, R901315 does not show any improvement in elongation to failure during tensile tests. Eliminating those coarse particles is expected to improve the ductility and toughness of this isotropic batch.

A two-dimensional, transient, compressible isothermal and two-phase model for the air-side electrode of PEM fuel cells

A two-dimensional, transient, compressible, isothermal and two-phase flow of reactant–product mixture in the air-side electrode of proton exchange membrane fuel cells (PEMFC) are numerically studied in the present paper. The mixture is composed of four species: oxygen, nitrogen, liquid water and water vapor. The governing PDE’s are conservation of the water vapor and oxygen species, momentum equation of the mixture ( gas + liquid ), mass conservation of the liquid phase, and mass conservation of the mixture. In this study, a separate PDE for the mass conservation of the liquid water is solved to calculate the saturation levels. The capillary pressure was used to determine the slip velocity between the phases. A full compressible form of the momentum equation was used, with the ∇ ⋅ V preserved in the equation. The Maxwell–Stefan equation was used to model the diffusive fluxes of the multi-component gas mixture. The strongly coupled equations are solved based on a recently developed finite volume SIMPLER scheme of S.V. Patankar, Numerical Heat Transfer and Fluid Flow, Hemisphere Publishing Corp., McGraw-Hill Book Company, 1984. The computational domain consists of two regions; an open area (gas delivery channel) linked to a porous gas diffusion layer (GDL). A single (unified) set of the PDE’s are used for the whole domain with the corresponding properties of each sub-domain. A polarization curve for the whole spectrum of the dry and wet regions were obtained. The results were compared with the experiments of E.A. Ticianelli, C.R. Derouin, A. Redondo, S. Srinivasan, J. Electrochem. Soc. 135 (1988) 2209, and good agreements were achieved.

Solving the Beck and Wieland model with optimal experimentation in DualPC

Currently, there is a renewed interest in the use of optimal experimentation (adaptive control) in economics. Example are found in [Amman, H. M. & Kendrick, D. A. (1999). Should macroeconomic policy makers consider parameter covariances. Computational Economics 14, 263–267; Amman, H. M. & Kendrick, D. A. (2003). Mitigation of the Lucas critique with stochastic control methods. Journal of Economic Dynamics and Control 27, 2035–2057; Cosimano, T. F. Optimal experimentation and the perturbation method in the neighborhood of the augmented linear regulator problem. Journal of Economics, Dynamics and Control (in press); Cosimano, T. F., & Gapen, M. T. (2005b). Recursive methods of dynamic linear economics and optimal experimentation using the perturbation method, Working paper. Notre Dame, Indiana, USA: Department of Finance, University of Notre Dame; Cosimano, T. F., & Gapen, M. T. (2005a). Program notes for optimal experimentation and the perturbation method in the neighborhood of the augmented linear regulator problem, Working paper. Notre Dame, Indiana, USA: Department of Finance, University of Notre Dame; Cosimano, T. F., & Gapen, M. T. (2006). An algorithm for approximating optimal experimentation problems using the perturbation method, Working paper. Notre Dame, Indiana, USA: Department of Finance, University of Notre Dame; Tesfaselassie, M. F., Schaling, E., & Eijffinger, S. (2007). Learning about the term structure and optimal rules for inflation targeting, Working paper. Tilburg, The Netherlands: Tilburg University; Tucci, M. P. (1997). Adaptive control in the presence of time-varying parameters. Journal of Economic Dynamics and Control, 22, 39–47; Wieland, V. (2000a). Learning by doing and the value of optimal experimentation. Journal of Economic Dynamics and Control, 24, 501–543; Wieland, V., (2000b). Monetary policy, parameter uncertainty and optimal learning. Journal of Monetary Economics, 46, 199–228] . In this paper we present the Beck & Wieland model [Beck, G., & Wieland, V. (2002). Learning and control in a changing economic environment. Journal of Economic Dynamics and Control, 26, 1359–1378] and the methodology to solve this model with time-varying parameters using the various control methods described in [Kendrick, D. A. (1981). Stochastic control for economic models (1st ed.), New York, NY, USA: McGraw-Hill Book Company; Kendrick, D. A. (2002). Stochastic control for economic models (2nd ed.) Available at url: http://www.eco.utexas.edu/faculty/Kendrick] . Furthermore, we also provide numerical results using the DualPC software [Amman, H. M., & Kendrick, D. A. (1999). The DualI/DualPC software for optimal control models: User’s guide. Working paper, Austin, TX 78712, USA: Center for Applied Research in Economics, University of Texas] and show first evidence that optimal experimentation or Dual Control may produce better results than Expected Optimal Feedback.

Mathematical properties and parameter estimation for transit compartment pharmacodynamic models

One feature of recent research in pharmacodynamic modelling has been the move towards more mechanistically based model structures. However, in all of these models there are common sub-systems, such as feedback loops and time-delays, whose properties and contribution to the model behaviour merit some mathematical analysis. In this paper a common pharmacodynamic model sub-structure is considered: the linear transit compartment. These models have a number of interesting properties as the length of the cascade chain is increased. In the limiting case a pure time-delay is achieved [Milsum, J.H., 1966. Biological Control Systems Analysis. McGraw-Hill Book Company, New York] and the initial behaviour becoming increasingly sensitive to parameter value perturbation. It is also shown that the modelled drug effect is attenuated, though the duration of action is longer. Through this analysis the range of behaviours that such models are capable of reproducing are characterised. The properties of these models and the experimental requirements are discussed in order to highlight how mathematical analysis prior to experimentation can enhance the utility of mathematical modelling.

Hydromagnetic stagnation point flow by a perturbation technique

An analysis is performed to study the momentum, heat and mass transfer characteristics of MHD natural convection flow and heat generating/absorbing fluid at the stagnation point of an isothermal two-dimensional porous body immersed in a fluid saturated porous medium. The results are obtained by solving the coupled non-linear partial differential equations describing the conservation of mass, momentum and energy by a perturbation technique [A. Aziz, T.Y. Na, Perturbation Methods in Heat Transfer, Springer-Verlag, Berlin, 1984 (pp. 1–184), R. Kenneth Cramer, Shih-I Pai, Magnetofluid Dynamics for Engineers and Applied Physicists, McGraw-Hill Book Company, New York, 1973 (pp. 164–171).]. These results are presented to illustrate the influence of the Hartmann number, Prandtl number, and dimensionless heat generation/absorption coefficient and suction injection parameter. Numerical results for the dimensionless velocity profiles, the temperature profiles, the local friction coefficient and the local Nusselt number are presented for various parameters. These effects of the different parameters on the velocity and temperature as well as the skin friction and wall heat transfer are presented graphically.

On the Hydrolysis of the Tetravalent Uranium Ion U4+

The formation of the hydrolytic complexes of U(IV) has been investigated at 25.00°C by measuring the Emf of a cell containing inert metal sponge and glass electrodes, in 3 mol·dm−3 aqueous NaClO4 solutions containing both U(VI) and U(IV) at acidities ranging between 10−0.5 and 10−1.8 mol·dm−3. The lower limit of acidity is imposed by the precipitation of the sparingly soluble oxides of U(IV) whereas the upper limit has been chosen in order to avoid large corrections for the liquid junction potential. The experimental data have been treated using classical graphical methods (Rossotti, F.J.C., Rossotti, H.: The Determination of Stability Constants. McGraw Hill Book Company, Inc. New York (1961)) and by the computerized least-squares program LETAGROP-ETITR (Sillen, L.G., Warnqvist, B.: Arkiv for Kemi. 31, 315–39 (1969)). The results can be explained by assuming the formation of two mononuclear complexes, U(OH)3+ and \(\mathop {{\rm U(OH)}}\nolimits_4^0\). The obtained formation constants in the 3 mol·dm−3 NaClO4 ionic medium are: \({\rm log}_{10}^\ast\beta_{1}=-1.62\pm 0.02\) and \({\rm log}_{10}^\ast\beta_{4} = -7.70 \pm 0.04\). The formal standard potential * E 6,4 for the couple UO2 2 +/U4 + at the same conditions is 335.7± 0.5 mV.