bluuebunny/crossref_metadata_2025 huggingface dataset:
An Analysis of Inverse Heat Transfer Problems With Phase Changes Using an Integral Method
Authors: Zabaras N. , Mukherjee S. , Richmond O.
Published: October 2009

This paper provides a methodology for the solution of certain inverse heat transfer problems with phase changes. It is aimed particularly at the design of casting processes. The idea is to use the inverse method to calculate the boundary flux history that will achieve the velocities and fluxes at the freezing front that are needed to control liquid feeding to the front, as well as yield the desired cast structure. The proposed method also can be applied to predict the freezing front motion using temperature measurements at internal points. A boundary element analysis with constant elements is used here in conjunction with Beck’s sensitivity analysis. The accuracy of the method is illustrated through one-dimensional numerical examples. It is demonstrated that, by using an integral formulation, one can extend all of the current methods for solving inverse heat conduction problems with stationary boundaries, to inverse Stefan problems. Such problems are of great technological significance.
The Influence of Secondary Convection on Axial Segregation in a Floating Zone
Authors: Murthy J. Y.
Published: October 2009

The redistribution of impurity due to secondary convection in a cylindrical floating zone is studied using a control volume-based numerical technique. The flow is induced by differential rotation of the feed rod and crystal. Attention is focused on the transient stage of segregation. It is found that the transient length increases with the strength of secondary convection. A maximum in radial segregation is found to occur when secondary convection creates radial gradients but is not strong enough to homogenize them. The influence of cellular structure on the transient length is also examined.
Electrically Induced Shape Oscillation of Drops as a Means of Direct-Contact Heat Transfer Enhancement: Part 1—Drop Dynamics
Authors: Kaji N. , Mori Y. H. , Tochitani Y.
Published: October 2009

The shape oscillation of liquid drops passing through an immiscible liquid medium subject to a low-frequency (1 ∼ 16 Hz) alternating electric field having a sinusoidal waveform has been studied experimentally with the intention of investigating the enhancement of the direct-contact heat exchange between the two liquids. We have found that the field can induce, depending on its frequency, not only the resonant oscillation of the second mode of the drops, but also another peculiar oscillation that is related to the resonant oscillation of the third mode superposed on the second-mode oscillation.
Transition Boiling Models in Heat Exchangers
Authors: France D. M. , Shin S. K. , Azimi M. , Shafiei A.
Published: October 2009

Models are presented for the inclusion of transition boiling heat transfer in the thermal analysis of liquid-heated boiling water heat exchangers. A relation was developed from experimental data for the prediction of the quality change in the transition boiling region. This quality relation was used alone and in conjunction with a transition boiling heat transfer coefficient to formulate two successful models. Predictions of heat exchanger heat transfer, including the transition boiling models, were compared with experimental results for high-pressure water in the range 7–15.3 MPa over a mass flux of 0.7–3.2 Mg/m2s.
A Numerical Study of Turbulent Heat Transfer in a Spherical Annulus
Authors: Stein W. , Brandt H.
Published: October 2009

A numerical study of steady, buoyant, incompressible water flow and heat transfer through a spherical annulus has been made. A two-dimensional computer code based on the TEACH code was rewritten in spherical coordinates to model the Navier–Stokes equation and to model fluid turbulence with a k–ε turbulence model. Results are given for the total system Nusselt number, local heat transfer rate, and fluid flow characteristics for both buoyant and nonbuoyant laminar and turbulence modeled flow. Incorporating both the turbulence model and buoyancy into the calculations improves the results.
Molten Metal Flow Around the Base of a Cavity During a High-Energy Beam Penetrating Process
Authors: Wei Peng Sheng , Chiou Lih Ren
Published: October 2009

An axisymmetric, quasi-steady-state model for the flow of molten metal in a thin layer surrounding the lower region of a vapor-filled cavity formed during a high-energy beam penetrating process is investigated for the first time. The shape of the vapor–liquid interface is determined by solving the momentum and energy equations and satisfying global mass conservation. Results show that the effective surface pressure and the force caused by the surface tension induce the upward flow of the liquid layer, which is responsible for the formation of the cavity. Distributions of the cavity temperatures, the liquid layer thickness, and the tangential velocity are also presented in this initial study.
Effects of Natural Convection on Ice Formation Around an Isothermally Cooled Horizontal Cylinder
Authors: Cheng K. C. , Inaba H. , Gilpin R. R.
Published: October 2009

The effects of maximum density near 4°C on steady-state, two-dimensional ice formation around an isothermally cooled horizontal cylinder in a quiescent water bath are studied experimentally for ambient water temperature T∞ = 1.9 to 18.0°C and cylinder surface temperature Tw = −20.0 to −16.2°C. The stagnation point Nusselt number, local heat transfer coefficient, and average Nusselt number behavior at the ice-water interface are studied using such parameters as ambient temperature, Rayleigh number, and a modified Grashof number Grd*. The temperature field in the ice layer is determined from the measured ice profiles by a point-matching method using a series solution of the Laplace equation in the ice. The average ice layer thickness and total low-temperature heat stored in the ice layer can be correlated using the parameter Gr*d0.5/θc2. A flow direction inversion region exists in the range T∞ = 5.2 to 8.1°C, Grd* = 3.8×104 to 1.3×105, and a minimum Nusselt number behavior occurs at T∞ = 5.2°C. Flow visualization photographs of the flow patterns near the ice surface are presented for T∞ = 3.8, 5.2, 8.1, and 12.1°C.
Forced Convection in the Entrance Region of a Packed Channel With Asymmetric Heating
Authors: Cheng P. , Hsu C. T. , Chowdhury A.
Published: October 2009

The problem of a thermally developing forced convective flow in a packed channel heated asymmetrically is analyzed in this paper. The flow in the packed channel is assumed to be hydrodynamically fully developed and is governed by the Brinkman–Darcy–Ergun equation with variable porosity taken into consideration. A closed-form solution based on the method of matched asymptotic expansions is obtained for the axial velocity distribution, and the wall effect on pressure drop is illustrated. The energy equation for the thermally developing flow, with transverse thermal dispersion and variable stagnant thermal conductivity taken into consideration, was solved numerically. To match the predicted temperature distributions with existing experimental data, it is found that a wall function must be introduced to model the transverse thermal dispersion process in order to account for the wall effect on the lateral mixing of fluid. The variations of the local Nusselt number along the streamwise direction in terms of the appropriate parameters are illustrated. The thermal entrance length effect on forced convection in a packed channel is discussed.
Asymmetric Scaled Equation of State and Critical Behavior of Binary Mixtures
Authors: Anisimov M. A. , Kiselev S. B. , Kostukova I. G.
Published: October 2009

An equation of state for binary mixtures, accounting for the asymmetry with respect to the critical isochore in the wide neighborhood of the liquid–gas critical line, has been obtained on the basis of the isomorphic scaled free energy of mixtures and the extended scaled equation of state for pure fluids. Universal behavior of critical binary mixtures is demonstrated. The universal function is used for the description of experimental heat capacity data for a number of binary mixtures.
Combined Parameter and Function Estimation in Heat Transfer With Application to Contact Conductance
Authors: Beck J. V.
Published: October 2009

This paper discusses parameter estimation, function estimation, and a combination of the two. An example of parameter estimation is the determination of thermal conductivity of solids from transient temperature measurements. An example of function estimation is the inverse heat conduction problem, which uses transient temperature measurements to determine the surface heat flux history. The examples used herein involve the determination of the thermal contact conductance. Two sets of very good data are analyzed. One set of steady-state data was obtained by Antonetti and Eid (1987). The other set was obtained by Moses and Johnson (1986) under transient conditions for periodic contact. Both sets of data are used to illustrate parameter, function, and combined estimation. It is demonstrated that the proposed methods are more powerful then commonly accepted methods. Many other heat transfer problems can be treated using the proposed techniques.
Progress in Turbulent Forced Convection
Authors: Pletcher R. H.
Published: October 2009

This paper presents a brief account of some recent progress toward the understanding and prediction of turbulent forced convection. The impact of technological advances in electronics and optical methods is pointed out. Coverage includes observations on structure, measurement techniques, experimental results, numerical strategies, turbulence modeling, and large eddy and full simulation.
Transient Response and Disturbance Growth in Vertical Buoyancy-Driven Flows
Authors: Gebhart B.
Published: October 2009

The basic physical characteristics of flow response to a changed bounding-surface energy input is reviewed. Response regimes are delineated in terms of locally laminar, unstable, transition, and turbulent flows and dimensionality and regimes intermediate to the others. Very large transient heat transfer effects arise. A key general question is how such regimes become unstable and progress to turbulence. Transient disturbance growth analysis is very difficult and few results are available. This paper develops a general and purely numerical formulation for two-dimensional transient response and disturbance growth. It relies on imposed random flow and associated temperature and disturbance motion pressure disturbances. It applies to any boundary region regime and is specialized here to disturbance growth in a developing buoyancy-driven flow, as an example.
Heat Transfer During Melting and Solidification of Metals
Authors: Viskanta R.
Published: October 2009

Recent advances in the understanding of melting and solidification heat transfer in metals and alloys are discussed. Since heat transfer is generally the rate-determining process, the emphasis in the paper is on fundamental heat transfer processes during solid–liquid phase transformation and comparison between mathematical-numerical model predictions with experimental data. After a brief discussion of theoretical considerations, unidirectional and multidirectional melting and solidification processes are reviewed. The important role played by buoyancy-driven fluid flow is discussed and problem areas needing research attention are identified.
Burnout on Cylinders
Authors: Lienhard J. H.
Published: October 2009

The cylinder is the most thoroughly studied boiling burnout configuration, starting with Nukiyama’s pioneering study and continuing through the present. This review paper summarizes much of what is known about the peak boiling heat flux in this arrangement taking into account such variables as size, properties of the boiled liquid, gravity, liquid subcooling, velocity of an imposed crossflow, and certain “nuisance” variables, as well.
Convective Boiling in Vertical Channels With Different Offset Strip Fin Geometries
Authors: Mandrusiak G. D. , Carey V. P.
Published: October 2009

Newly obtained local heat transfer data are presented for flow boiling of liquids in two partially heated vertical channels with different offset strip fin geometries operating at low to moderate wall superheat levels. Experiments were conducted in special test sections that permitted direct visual observation of the boiling process while simultaneously measuring the heat transfer coefficient along the channel. Data for which nucleate boiling appeared to be completely suppressed were analyzed together with similar results for other offset fin geometries to assess the effects of channel geometry variations on the two-phase heat transfer coefficient during annular film-flow evaporation. For all geometries considered, the data for annular film-flow evaporation were found to correlate well in terms of modified versions of the F and Martinelli parameters used by Bennett and Chen (1980) to correlate similar data for round tubes. For fin matrices of similar size and configuration, the forced convective component of the two-phase heat transfer coefficient was found to be well represented by a single F-parameter correlation curve. However, F-factor correlations for matrices having significant differences in fin and channel dimensions were found to differ substantially. An approximate superposition method for including the contribution of nucleate boiling to the two-phase heat transfer coefficient at low to moderate wall superheat levels is also proposed.
Numerical Solution of an Open Cavity, Natural Convection Heat Exchanger
Authors: Richmond D. A. , Hollands K. G. T.
Published: October 2009

An “open-cavity” natural convection heat exchanger is one in which the flow on one side is driven by buoyancy forces and in which the effect of associated piping, valves, and fittings on that side can be ignored, since the exchanger is effectively exposed there to an extensive fluid of uniform temperature. This paper reports a finite volume numerical solution of the full set of equations governing the flow on the natural convection side of such a heat exchanger. The exchanger’s dimensionless performance is shown to depend on five dimensionless groups: a modified Rayleigh number Ra*, a flow number F describing the forced convection heat capacity, a Biot number Bi describing the effect of forced convection side heat transfer coefficient, an aspect ratio AR, and the Prandtl number Pr. A parametric study is performed for suitable ranges of Ra*, F, and Bi, and for Pr = 6 and AR = 0.1. The results are presented in terms of a Nusselt number, a dimensionless flow rate, and the exchanger effectiveness as a function of these variables.
Calculated Temperature and Stress Distribution in the Edge Cladding of a Pulsed-Laser Slab
Authors: Lee Y. J. , Julien H. L.
Published: October 2009

The efficiency of solid-state laser amplifiers can be improved significantly by using an absorbing edge cladding on the laser slab to reduce parasitic light oscillation within the slab. An analytic solution for the conduction and thermal stress problem in a simply supported cladding has been developed for a periodic incident-light energy source in order to evaluate the influence of amplifier design variables on cladding stress. An approximate relationship between pulse frequency and the absorptivity corresponding to a minimum difference in thermally induced stresses is shown to be in agreement with this solution.
Relation Between the Thermal Effectiveness of Overall Parallel and Counterflow Heat Exchanger Geometries
Authors: Pignotti A.
Published: October 2009

A simple relation is established between the thermal effectiveness of two heat exchanger configurations that differ from each other in the inversion of either one of the two fluids. Using this relation, if the expression for the effectiveness of a configuration, as a function of the heat capacity rate ratio, and the number of heat transfer units, is known, the corresponding expression for the “inverse” configuration is immediately obtained. The relation is valid under the assumptions of temperature independence of the heat transfer coefficient and heat capacity rates, when one of the fluids proceeds through the exchanger in a single, mixed stream. The property is illustrated with several examples from the available literature.
Cost-Optimal Design of Dry Cooling Towers Through Mathematical Programming Techniques
Authors: Buys J. D. , Kro¨ger D. G.
Published: October 2009

The Constrained Variable Metric Algorithm is chosen to minimize the objective function (cost) in the design of a natural draft dry cooling tower. An existing cooling system design that has specific performance characteristics under prescribed operating conditions is selected as a reference unit. By changing design variables, but not exceeding prescribed constraints, a more cost-effective design is achieved. The influence of various parameters, and the sensitivity of the objective function to these parameters, are evaluated.
Augmentation of Laminar Forced-Convective Heat Transfer by the Application of a Transverse Electric Field
Authors: Fujino T. , Yokoyama Y. , Mori Y. H.
Published: October 2009

The effect of a uniform d-c electric field on laminar forced-convective heat transfer has been studied experimentally with a weakly conducting fluorocarbon refrigerant in the liquid state that is flowing in a channel confined by parallel-plate electrodes, one of which serves as a heat transfer surface of uniform heat flux. The dependencies of the heat transfer coefficient and the pressure drop on the sign and the magnitude of an applied voltage, the heat flux at the heat transfer surface, the electrical conductivity of the test fluid, etc. are presented, and the structure and the mechanism of the electroconvection causing the heat transfer enhancement are considered.
Heat Transfer in Compartment Fires Near Regions of Ceiling-Jet Impingement on a Wall
Authors: Cooper L. Y.
Published: October 2009

The problem of heat transfer to walls from fire-plume-driven ceiling jets during compartment fires is introduced. Estimates are obtained for the mass, momentum, and enthalpy flux of the ceiling jet immediately upstream of the ceiling–wall junction. An analogy is drawn between the flow dynamics and heat transfer at ceiling-jet/wall impingement and at the line impingement of a wall and a two-dimensional, plane, free jet. Using the analogy, results from the literature on plane, free-jet flows and corresponding wall-stagnation heat transfer rates are recast into a ceiling-jet/wall-impingement-problem formulation. This leads to a readily usable estimate for the heat transfer from the ceiling jet as it turns downward and begins its initial descent as a negatively buoyant flow along the compartment walls. Available data from a reduced-scale experiment provide some limited verification of the heat transfer estimate. Depending on the proximity of a wall to the point of plume–ceiling impingement, the result indicates that for typical full-scale compartment fires with energy release rates in the range 200–2000 kW and fire-to-ceiling distances of 2–3 m, the rate of heat transfer to walls can be enhanced by a factor of 1.1–2.3 over the heat transfer to ceilings immediately upstream of ceiling-jet impingement.
Axisymmetric Interfacial Condensation Model
Authors: Gerner F. M. , Tien C. L.
Published: October 2009

This paper employs a simple axisymmetric model to study interfacial condensation. Numerical results show the effects of interfacial forces, subcooling of the liquid, superheating of the vapor, and the presence of a noncondensable gas in the vapor. While pressure and shear stress play an important role in determining the flow fields, and hence interfacial mass and energy transport, interfacial mass fluxes do not. Subcooling of the liquid is the dominant mechanism in determining the interfacial condensation rate. While superheating of the vapor is insignificant, except near the critical point, a noncondensable gas in the vapor greatly reduces condensation.
Heat Transfer Characteristics in Two-Phase Closed Conventional and Concentric Annular Thermosyphons
Authors: Faghri A. , Chen M.-M. , Morgan M.
Published: October 2009

The heat transfer in the condenser sections of conventional and annular two-phase closed thermosyphon tubes has been studied experimentally and analytically. In addition, the results of a series of experiments on the flooding phenomena of the same thermosyphons are reported. Freon 113 and acetone were used as working fluids. An improved correlation was developed to predict the performance limits of conventional thermosyphons using the present and previously existing experimental data for flooding with different working fluids. The prediction of the theoretical Nusselt number for the situations associated with measured heat transfer coefficients in the condenser section indicated that the effect of interfacial shear on the film flow is small. The increase of the experimental reflux condensation heat transfer coefficients over theoretical predictions is attributed to waves at the vapor–liquid interface.
Finite Analytic Solution of Convective Heat Transfer for Tube Arrays in Crossflow: Part I—Flow Field Analysis
Authors: Wung Tzong-Shyan , Chen Ching Jen
Published: October 2009

The convective motion in two types of tube array is solved numerically by the Finite Analytic Method. The Finite Analytic Method utilizes the local analytic solution of governing differential equations in obtaining its discretized algebraic representation. Both in-line tube arrays and staggered tube arrays with longitudinal and transverse pitches of 2 are studied. The geometries are expressed in boundary-fitted coordinates on which the Navier–Stokes equations and energy equation are solved. Solutions for Reynolds numbers of 40, 120, 400, and 800 are obtained. Differences in stream function, vorticity function, and location of separation and reattachment for flow past in-line tube arrays and staggered tube array are predicted and compared. The zone of separation for both arrays tends to increase with increasing Reynolds number. The predicted results on flow field and heat transfer are shown to agree with available experimental measurements.
Natural Convection Flows Due to the Combined Buoyancy of Heat and Mass Diffusion in a Thermally Stratified Medium
Authors: Angirasa D. , Srinivasan J.
Published: October 2009

This paper presents a numerical study of laminar doubly diffusive free convection flows adjacent to a vertical surface in a stable thermally stratified medium. The two buoyant mechanisms are thermal diffusion and species diffusion. The species concentration is assumed to be small. Boussinesq approximations are incorporated and the governing conservation equations of mass, momentum, energy, and species are nondimensionalized. These equations are solved using a finite-difference method. The results are explained in terms of the basic physical mechanisms that govern these flows. It is observed that the ambient thermal stratification has a profound influence on the transport characteristics. The results show many interesting aspects of the complex interaction of the two buoyant mechanisms.
Heat and Mass Transfer During Piloted Ignition of Cellulosic Solids
Authors: Atreya A. , Wichman I. S.
Published: October 2009

This study presents the results of an experimental and theoretical investigation into the heat and mass transfer processes that occur during piloted ignition of cellulosic materials. The experiments were conducted on both horizontal and vertical samples of thick pieces of wood initially at ambient temperature. The time required to ignite the sample in the presence of a pilot flame and the surface temperature–time history of the sample were recorded. The data so obtained were used to identify the critical surface temperature at ignition. These results compare well with those previously reported in the literature. Based on the experimental observations an approximate analytical model for the piloted ignition process was developed. The model predictions are in good agreement with the experimental measurements. This model is based on the following observations: (i) Critical conditions at ignition are achieved solely by external radiation and surface radiant emission plays a dominant role in determining the surface temperature at ignition, and (ii) although the heat lost by the flame to the solid at the instant of ignition is significant and may cause thermal quenching its contribution to the enthalpy rise of the solid is negligible. Also, to simplify the description of the gas-phase combustion process the concepts of nearly constant limit diffusion flame temperature at extinction and nearly constant heat of combustion of oxygen for most hydrocarbons are profitably employed. The approximate model presented here provides simple formulas that show good agreement with the experiments. It also provides some justification for the use of critical surface temperature and critical fuel mass flux as ignition criteria.
Modeling the Thermally Governed Transient Flow Surges in Multitube Condensing Flow Systems With Thermal and Flow Distribution Asymmetry
Authors: Wedekind G. L. , Bhatt B. L.
Published: October 2009

In a tube-type condenser involving complete condensation, small changes in the inlet vapor flow rate momentarily cause very large transient surges in the outlet liquid flow rate. An equivalent single-tube model is proposed that predicts these transient flow surges for a multitube system. The model, based upon a system mean void fraction model developed earlier, includes the effects of thermal and flow distribution asymmetry associated with each individual condenser tube in the multitube system. Theoretical and experimental verification for a two-tube system is presented.
Surface Exchange Model of Radiative Heat Transfer From Anisotropic Scattering Layers
Authors: Ma Y. , Lee H. S.
Published: October 2009

Scaling laws are developed that reduce the radiative heat transfer problem in an isothermal, absorbing-emitting, planar layer to a radiative exchange problem between gray surfaces through a nonparticipating medium. The wall reflectivity and the surface temperatures become the parameters to be scaled. The scaled parameters are obtained by matching the heat fluxes leaving the original layer. The resulting scaled nonparticipating reflectivity is found to be a function of the original medium reflectivity and the optical depth. The scaled nonparticipating surface temperatures include the influence of the medium temperature and the boundary source. Excellent agreement is shown for the layer reflectance, transmittance, and emittance of some anisotropic scattering media, which are scaled to a nonparticipating layer using this and the previously developed scaling laws.
Transient Mass Transfer in Parallel Passage Dehumidifiers With and Without Solid Side Resistance
Authors: Chuah Y. K. , Norton P. , Kreith F.
Published: October 2009

Desiccant dehumidifiers have been used in industrial and commercial processes to provide air of lower relative humidity than can be achieved readily with vapor compression equipment. Parallel passage rotary wheel regenerators with silica gel on the passage walls are used as dehumidifiers for air-conditioning applications. This study presents an investigation of transient mass transfer in a parallel passage dehumidifier with a thin layer of silica gel on the passage walls. A two-film resistance model was used to approximate the overall transfer resistance between the process air and the solid desiccant. Isothermal transient mass transfer experiments using parallel passages with silica gel coated walls were conducted and analyzed. It was found that the two-film model agrees with the experimental results within the experimental accuracy. Although only silica gel was used in this study, the results may be extended to other solid desiccants.
Heat Transfer From a Small Heated Region to R-113 and FC-72
Authors: Samant K. R. , Simon T. W.
Published: October 2009

An experimental investigation of heat transfer from a small heated patch to a subcooled, fully developed turbulent flow is conducted. The test patch, approximately 0.25 mm long and 2.0 mm wide, is located on the floor of a small rectangular channel through which a coolant (R-113 or FC-72) is circulated. A thin film of Nichrome deposited on a quartz substrate serves as an integrated heater element and resistance thermometer. The maximum achievable heat flux with R-113, limited by the thermal decomposition temperature of the fluid, is 2.04 MW/m2 at a bulk velocity of 1.8 m/s and a high wall superheat of 80° C. The results obtained with FC-72 show large temperature excursions at the onset of nucleate boiling and a boiling hysteresis near the onset of nucleate boiling. These effects decrease with increasing velocity and/or subcooling. The heat flux at departure from nucleate boiling increases with increasing velocity and/or subcooling. A maximum heat flux of 4.26 MW/m2 at departure from nucleate boiling is observed.
Natural Convection in Horizontal Porous Layers: Effects of Darcy and Prandtl Numbers
Authors: Kladias N. , Prasad V.
Published: October 2009

Natural convection in horizontal porous layers heated from below is studied by employing a formulation based on the Brinkman–Forchheimer–extended Darcy equation of motion. The numerical solutions show that the convective flow is initiated at lower fluid Rayleigh number Raf than that predicted by the linear stability analysis for the Darcy flow model. The effect is considerable, particularly at a Darcy number Da greater than 10−4. On the other hand, an increase in the thermal conductivity of solid particles has a stabilizing effect. Also, the Rayleigh number Raf required for the onset of convection increases as the fluid Prandtl number is decreased. In the stable convection regime, the heat transfer rate increases with the Rayleigh number, the Prandtl number, the Darcy number, and the ratio of the solid and fluid thermal conductivities. However, there exists an asymptotic convection regime where the porous media solutions are independent of the permeability of the porous matrix or Darcy number. In this regime, the temperature and flow fields are very similar to those obtained for a fluid layer heated from below. Indeed, the Nusselt numbers for a porous medium with kf = ks match with the fluid results. The effect of Prandtl number is observed to be significant for Prf < 10, and is strengthened with an increase in Raf, Da, and ks/kf. An interesting effect, that a porous medium can transport more energy than the saturating fluid alone, is also revealed.
Wind Tunnel Experiments on Cooling Tower Plumes: Part 2—In a Nonuniform Crossflow of Boundary Layer Type
Authors: Andreopoulos J.
Published: October 2009

The basic characteristics of plumes issuing into a boundary layer-type crossflow are reported. The flow can be considered as an interaction between two vorticity fields with different length scales and turbulence intensities. The large eddies of the oncoming boundary layer are responsible for the observed sudden changes in the plume direction. The type of structure emanating from the tower depends on the instantaneous velocity ratio. Mean velocities and normal velocity gradients are smaller than those in the case of uniform crossflow and therefore, the measured turbulence intensities are lower too. The cross-stream turbulence brings high-momentum fluid into the wake region and the velocity defect decays very rapidly. Dilution of the plumes takes place faster in the presence of external turbulence than in the case with uniform crossflow. The spreading rate is increased dramatically by the external turbulence, which causes different effects on the hydrodynamic and thermal fields.
Act1, a U-box E3 Ubiquitin Ligase for IL-17 Signaling
Authors: Liu Caini , Qian Wen , Qian Youcun , Giltiay Natalia V. , Lu Yi , Swaidani Shadi , Misra Saurav , Deng Li , Chen Zhijian J. , Li Xiaoxia
Published: October 2009

The adaptor protein Act1 functions as a ubiquitin ligase to mediate interleukin-17 receptor–dependent activation of nuclear factor-κB.
Rebuilding Broken Bones
Authors: McDonald Heather B.
Published: October 2009

Geometrically complex bone structures can be engineered with human stem cells and a customized bone scaffold.
ITERATED EULER'S INTEGRALS AND NORMALIZED MULTIPLE SINE FUNCTIONS
Authors: TANAKA HIDEKAZU
Published: October 2009

We introduce iterated Euler's integrals, and we give expressions using zeta functions. Moreover, we prove that normalized multiple sine functions are expressed via iterated Euler's integrals. Then, we show basic properties of multiple sine functions from these results containing Kummer type formula.
A LANDMARK-BASED NAVIGATION SYSTEM FOR HIGH SPEED CARS IN THE ROADS WITH BRANCHES
Authors: SANJABI MERCEDEH , MAABI SOMAYEH , ESMAEILI ZAHRA , JAHANIAN ALI , KHALIGHI SIRVAN
Published: October 2009

Landmark-based car navigation is a widely used technique for automotive and robot navigation. Wireless landmarks have some key features such as robustness and simple detection that make them suitable for automotive navigation. In this paper, a light-weight embedded algorithm for high speed car navigation in the roads with branches is presented which can be efficiently used in real-time automotive systems. We implemented the proposed algorithm on a real-time MIPS-based embedded system and analyzed its accuracy and efficiency in some real road maps, especially for high speed movements in real roads. Experimental results show that the proposed algorithm can be used for high speeds (up to about 360 km/h) with a very small error rate. Additionally, the experimental results show that the power consumption of the proposed system is suitable for built-in car applications.
SPORTS BIOMECHANICAL INFORMATION ACQUISITION AND EVALUATION FOR KAYAKING EVENTS
Authors: MA ZUCHANG , ZHANG JINGMIN , SUN YINING , MEI TAO
Published: October 2009

Intensive understanding of sports biomechanical principles is an essential issue for sprint kayaking. In recent years, the authors have studied the acquisition of biomechanical information and the evaluation of competitive ability on sprint kayaking. In this study, first, an oar force sensor was developed to detect the stroke forces applied by paddler. The sensor was attached to a paddle with minimum mechanical involvement, hence the mechanical properties of the paddle was not changed. Second, an on-water instrument of biomechanical information acquisition was developed to detect stroke force, stroke frequency, stroke power, kayak speed, and acceleration synchronously. Third, 12 evaluation factors for kayaking ability were proposed based on the factor analysis. The 12 factors include (1) the stroke rate; (2) the speed fluctuation; (3 and 4) the hull pose (L/R); (5 and 6) the stroke force (L/R); (7 and 8) the endurance (L/R); (9 and 10) the stroke technique (L/R); (11 and 12) and the stroke rhythm (L/R). Finally, the stroke rate and the forward stoke technique was analyzed briefly.
THE TECTONICS OF THE SCHICHALLION COMPLEX
Authors: RAST NICHOLAS
Published: October 2009

The results of the present investigation of the Schichallion complex can be summarized as follows :–

(i) The succession established by Bailey & McCallien (1937) is confirmed.

(ii) The imprints of four separate movements, F
1
to F
4
, have been found in the area.

(iii) F
1
and F
2
are somewhat closely connected and are responsible for the two major systems of folding, which have produced the “Schichallion swing”.

(iv) No indications of “twisting” or “torsion” have been found.
On the Occurrence of the Genus
Physeter
(or Sperm Whale) in the Red Crag of Felixstow
Authors: Charlesworth Edward
Published: October 2009

Some years since, whilst looking over a collection of fossils in the possession of Mr. Brown of Stanway, I was struck by the appearance of a cylindrical nodule from the Red Crag of Felixstow, which seemed to me to exhibit indications of an organic structure unlike that of any fossil body which had previously come under my notice. With the permission of its owner I had a section made of this fossil; but the characters which it presented upon being cut did not enable me to arrive at any determination respecting its real nature. At a subsequent period, I learned from Mr. Brown that the nodule in question had been submitted by Professor Owen to microscopical examination, and identified as the tooth of a Cachalot.

In the reports of the British Association for 1842, this tooth is included in the list of British Fossil Mammalia; but Mr. Owen, through mistake, has there assigned it to the “Diluvium of Essex.” I am informed by Mr. Brown, that he procured the specimen from a man at Felixstow, who stated that he picked it up on the beach; and as several of the rarest known Crag fossils have been obtained at this spot under similar circumstances, there is no room to doubt its being a genuine fossil of the Crag formation.
On some of the Effects of the Holmfirth Flood
Authors: Prestwich Joseph
Published: October 2009

The broad tract of hilly country, which stretches north and south on the borders of Lancashire and Yorkshire, rises, in some places between Manchester and Huddersfield, to the height of nearly 2000 feet. The central ridge is here composed of the Millstone Grit Series, the elevated surfaces of which form extensive barren moors, and from which, owing to their lithological character and the large fall of rain, the surface-drainage is very considerable. On its eastern slope, the water is carried off by numerous small streams, falling into the various tributaries of the Humber. Their usual coarse is through narrow and picturesque valleys, which penetrate deep into the hills; amongst them is that of the Holme, which commences in the central range of hills, winds for nine miles east and north, and then joins the valley of the Colne at Huddersfield: it is well-wooded, and the scenery is generally bold and fine. At a short distance from the top of the valley, the Holme is joined by the Digley streamlet; the latter, however, being apparently the main stream, and draining, according to Capt. Moody, about 1920 acres of surface. It at first flows through a narrow and uncultivated ravine, which, three miles above the small town of Holmfirth, opens out into a narrow valley. This valley has always been subject to occasional floods, arising, however, from natural causes: one of the most disastrous occurred in 1777.
Notes on Ancient Boulder-clay of Natal
Authors: Sutherland
Published: October 2009

T
here
is largely developed in the Colony of Natal a formation which seems to be in all essential particulars identical with Mr. Bain’s claystone porphyry of the Cape of Good Hope. This formation flanks a long range of sandstone hills, which runs from the Tugela river frontier, at a distance of some six or eight miles from the sea, across the Umgeni river, and through the Berea hills to the mouth of the Umbilo. It also crops out extensively near Maritzburg, and stretches thence, in one direction, over the Umgeni and Umvoti to the Tugela valley between Greytown and the Biggersberg; and in the other direction over the Umlasi and Umkomasi towards the opposite frontier. In the latter course it goes onwards to the St. John’s river and to the further districts of the Cape.

The deposit itself consists of a greyish-blue argillaceous matrix, containing fragments of granite, gneiss, graphite, quartzite, greenstone, and clay-slate. These imbedded fragments are of various size, from the minute dimensions of sand-grains, up to vast blocks measuring 6 feet across, and weighing from 5 to 10 tons. They are smoothed, as if they had been subject to a certain amount of attrition in a muddy sediment; but they are not rounded like boulders that have been subjected to sea-breakers. The fracture of the rock is not conchoidal, and there is manifest in its substance a rude disposition towards wavy stratification.

The general appearance is that of a clay which has been deposited by aqueous action
Description of a Jaw of
Hyotherium
, from the Pliocene of India
Authors: Lydekker R.
Published: October 2009

I am again indebted to Col. J. W. Watson, the Political Resident in Kattiawar, for an interesting addition to our knowledge of the Siwalik fauna of Perim Island, on the western coast of India. The specimen in question (which Col. Watson has presented to the British Museum) is a portion of the left maxilla, with the three true molars, of a species of
Hyotherium
, which is apparently distinct from any named form. The fragment, of which an oral view is given in the accompanying woodcut, has been slightly water-worn, but not to such an extent as to damage it materially; the first molar has the dentine of the summits of the columns exposed by attrition, while the third molar is scarcely affected by such action. The teeth carry
the usual four main columns, with accessory columns on the inner side of the median longitudinal cleft, and have a well-marked and crenulated cingulum on the inner and fore-and-aft surfaces. The crowns of the first and second molars are squared and rather broader than long, while that of the third tooth has its postero-internal angle produced and its outer border sloping towards the median line.

The specimen may without doubt be referred to the genus Hyotherium, in the sense in which (following the lead of the late Prof. Peters) I have employed that term in the 'Catalogue of the Fossil Hammalia in the British Museum', and we may accordingly to compare it with the named European and Asiatic species of that
On a new Genus of Madreporaria (
Glyphastræa
), with Remarks on the Morphology of
Glyphastræa Forbesi
, Ed. & H., from the Tertiaries of Maryland, U. S.
Authors: Duncan P. Martin
Published: October 2009

Many years since, the late Dr. S. P. Woodward drew my attention to some very fine specimens of
Septastræa Forbesi
, Ed. & H., in the British Museum, and lately a well-preserved specimen has been sent to me from the Philosophical Institution at Scarborough. There has always been a doubt in my mind regarding the classificatory position of this large branching Tertiary species, and the examination of the specimen lately sent confirms the impression that the species differs so much from the Mesozoic
Septastrææ
that it cannot remain in the same genus, although it must still be placed in the Goniastræoid alliance.

The species mentioned in the ‘Histoire Naturelle des Coralliaires’ by Milne-Edwards and Jules Haime, described by M. de Fromentel in his ‘Introduction à l'étude des Polypiers,’ and published by myself in the “Monograph of the British Fossil Corals” (Pal. Soc. Lond.), with one exception, have the axial space nearly or quite open, and the columella is either absent or very rudimentary. But the species named after the late E. Forbes, I find, has the axial space completely closed, either by united septal ends with some additional tissue, or by a columella, which, by uniting with a number of septal ends and being increased in bulk by a remarkable dissepimental tissue, forms a very projecting central mass in perfect and full-grown calices.

The genus
Seiptastrcea
originated with d'Orbigny in 1849, and the diagnosis he gave was partly reproduced by Milne-Edwards and Jules tIaime in 1857. The species described in the
On the Occurrence of Species of the Genus
Diphyphyllum
, Lonsdale, in the Lower Carboniferous Strata of Scotland, with a Description of some new Species and Notices of Varieties
Authors: Thomson James
Published: October 2009

The object of this communication is to offer evidence in favour of the recognition of the genus
Diphyphyllum
, which was defined many years since by Lonsdale, and which has not been definitely accepted by any palæontologist, with the exception of M'Coy. It is proposed to give a slight history of the genus and species, and then to notify the occurrence of all the species with varieties in somewhat remarkable deposits in the Lower Carboniferous series of Scotland, and to describe two new species and a variety of one of them.

The facts now brought forward clearly prove the truth of Lonsdale's diagnosis of the genus, which enters the family Cyathophyllidæ of the Rugosa, and also necessitate the introduction into the generic diagnosis of the words “increase by gemmation and by fissiparity.”

The genus Diphyphyllum was defined by Lonsdale in Murchison, Keyserling, and De Verneuil's 'Geology of Russia and the Urals'(appendix, p. 622), and the type of the species D.
concinnum
, Lonsd., is in the collection of the Geological Society of London. The definition was as follows :—“ A stony lamelliferous polypidom ; lamcllm exceeding 12, biplated ; branched, branches dichotomous ; internal structure, triareal—1, central area intersected by flat, convex, or irregular diaphragms, no persistent axis ; 2, intermediate arca traversed vertically by lamellæ, interspaces crossed obliquely or downwards by extensions of the diaphragms and subordinate plates; 3, outer area traversed by lateral extensions of lamellæ, interspaces crossed by arched or vesicular laminæ inclined upwards and outwards ; stems not
Note on
Nummulites elegans
, Sowerby, and other English Nummulites
Authors: Jones T. Rupert
Published: October 2009

There being much confusion in the supposed relationship and published synonymy of
Nummulites elegans
(
Nummularia
, Sowerby), I propose to offer some remarks on the history of this species, more especially as less trouble would have been caused if I had taken more care years ago, and examined all, instead of only some, of Mr. Sowerby's specimens which have been associated with that name.

Having just now seen (October 1886), for the first time, the “Sowerby Collection” at the British Museum (Natural History, Cromwell Road), I find that Sowerby's labelled specimens of “
Nummularia elegans
” are really the same as my variety
Prestwichiana
of
Nummulites planulatus
, which the late Dr. Philippe De la Harpe regarded as a variety of
N. wemmelensis
. Other specimens, however, which belong to true
N. planulatus
, were confused by Sowerby with his
N. elegans
.

Specimens labelled “Nummularia elegans” on the original card, No. 44007 (1) in the “Sowerby Collection”, are exactly such as come from the well-known bed “no. 29” (at the base of the Barton Clay) of Prof. Prestwich's section of the strata at Alum Bay, Isle of Wight, in the Quart. Journ. Geol. Soc. vol. ii. (1846), p. 257, pl. 9. fig. 1. One horizontal section among them matches one of Sowerby's drawings in the ‘ Mineral Conchology,’ pl. 538, namely the 10th figure on the plate (counted in the order of the figs. 1, 2, 3), included in "fig. 2," and probably magnified two diameters. The other drawings in “fig. 2” do not match the
Notes on the Formation of Coal-seams, as suggested by evidence collected chiefly in the Leicestershire and South Derbyshire Coal-fields
Authors: Gresley W. S.
Published: October 2009

My principal object in this paper is to bring forward evidence in opposition to the view now generally accepted that coal-seams were formed from vegetation which grew on the spot.

It seems to me that the
growth-in-situ
theory has been, or is still, held by the majority of those who have considered or written upon the question to be the right one, partly because the accumulation of the vegetable matter of coal-beds by driftage appears to be totally beyond our comprehension, and partly (probably chiefly) because we have been told and led to believe that the underclays of coal-seams contain the
Stigmariæ
which were the very roots of the trees the remains of which constitute the bulk of the coal.

During an extensive experience in the midland district in connexion not only with coal-mining, but also with the working of the underbeds, the fireclays, both underground and in opencast workings, I have had unusual opportunities of studying the relationship of the coal-seams to the underbeds, their fossil contents, &c.

The various points for consideration may be taken as under:—

a
.

The relation of the fireclays to the coal-seams.

b
.

Mode of occurrence of
Stigmaria
in underbeds.

c
.

Erect fossil tree-stems with attached roots.

d
.

Lamination of coal-beds.

e
.

The presence of boulders &c. in the underclays.

f
.

The foreign bodies in coal-beds.

g
.

Marine fossils associated with coal-seams, brine, &c.

a. It must not be concluded, because almost every coal-seam