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The phonon is the physical particle representing mechanical vibration and is responsible for the transmission of everyday sound and heat. Understanding and controlling the phononic properties of materials provides opportunities to thermally insulate buildings, reduce environmental noise, transform waste heat into electricity and develop earthquake protection. Here I review recent progress and the development of new ideas and devices that make use of phononic properties to control both sound and heat. Advances in sonic and thermal diodes, optomechanical crystals, acoustic and thermal cloaking, hypersonic phononic crystals, thermoelectrics, and thermocrystals herald the next technological revolution in phononics., In recent decades, major technological revolutions have transformed our society and daily lives. Their remarkable innovations have been based primarily on our improved ability to manipulate two particles: electrons and [...]

Heat denaturation of recombinant human lactoferrin (rhLf) from rice with 3 different iron-saturation degrees, holo rhLf (iron-saturated), AsIs rhLf (60% iron saturation), and apo rhLf (iron- depleted), was studied. The 3 forms of rhLf were subjected to heat treatment, and the kinetic and thermodynamic parameters of the denaturation process were determined. Thermal denaturation of rhLf was assessed by measuring the loss of reactivity against specific antibodies. [D.sub.t] values (time to reduce 90% of immunoreactivity) decreased with increasing temperature of treatment for apo and holo rhLf, those values being higher for the iron-saturated form, which indicates that iron confers thermal stability to rhLf. However, AsIs rhLf showed a different behaviour with an increase in resistance to heat between 79 °C and 84 °C, so that the kinetic parameters could not be calculated. The heat denaturation process for apo and holo rhLf was best described assuming a reaction order of 1.5. The activation energy of the denaturation process was 648.20 kJ/mol for holo rhLf and 406.94 kJ/mol for apo rhLf, confirming that iron-depleted rhLf is more sensitive to heat treatment than iron-saturated rhLf. Key words: recombinant human lactoferrin, transgenic rice, heat denaturation, kinetic parameters, thermodynamic parameters. Nous avons etudie la denaturation thermique de lactoferrine recombinante humaine (rhLf) produite chez le riz possedant trois niveaux differents de saturation en fer : saturee en fer ou holo rhLf; saturee a 60 %, comme celle isolee du riz ou AsIs rhLf; et depourvue de fer ou apo rhLf. Les trois formes de rhLf ont ete soumises a un traitement thermique et les parametres cinetiques et thermodynamiques du processus de denaturation ont ete determines. La denaturation thermique de la rhLf a ete determinee en mesurant la perte de reactivite envers certains anticorps specifiques. Les valeurs de [D.sub.t] (temps requis pour reduire de 90 % l'immunoreactivite) diminuaient en fonction de l'augmentation des temperatures de traitement de l'apo et de la holo rhLf, ces valeurs etant plus elevees pour la forme saturee en fer, ce qui indique que le fer confere une stabilite thermique a la rhLf. Cependant la AsIs rhLf se comportait differemment, avec une augmentation de la resistance a la chaleur entre 79 °C et 84 °C, faisant en sorte que les parametres cinetiques ne pouvaient pas etre calcules. Le processus de denaturation thermique de l'apo et de la holo rhLf etait le mieux decrit en supposant que la reaction soit d'ordre 1,5. L'energie d'activation du processus de denaturation de la holo rhLf etait de 648,20 kJ/mol alors que celle de l'apo rhLf etait de 406,94 kJ/mol, ce qui confirme que la rhLf depourvue de fer est plus sensible a la chaleur que la rhLf saturee en fer. Mots-cles: lactoferrine recombinante humaine, riz transgenique, denaturation par la chaleur, parametres cinetiques, parametres thermodynamiques., Introduction Lactoferrin (Lf) is a nonheme iron-binding protein that belongs to the transferrin protein family. Lf is a monomeric glycoprotein with a molecular mass of 80 kDa, and the polypeptidic [...]

Electro-migration techniques, such as electrophoresis, are widely utilized in analytical sciences. If a single electrolyte is used, the field strength is typically assumed to be well-defined. Heat-associated field distortion (HAFD) has been suggested as a result of the nonuniform heat dissipation throughout the electrolyte; however, it has never been experimentally studied. Here, we experimentally demonstrated HAFD for the first time. We used capillary electrophoresis (CE) with a capillary having parts with different heat dissipation efficiencies. Our experiments showed a difference in field strength of approximately 1.5 times between the different parts of the capillary for a typical CE electrolyte. This result suggests that HAFD is a well pronounced phenomenon that can be a potential source of errors and instabilities in electro-migration experiments. 10.1021/ac102018m

The thermal conductivity of a metallic test piece is one of the principal parameters that influence the temperature buildup at tribocontacts and this normally plays an important role in the unlubricated dry sliding wear of metallic materials. It is, however, not clear whether thermal conductivity is an equally important parameter in the case of wear of metals at cryogenic temperatures, in particular, at liquid nitrogen temperature ([LN.sub.2]) of -196[degrees]C. In order to assess the influence of such a physical property of selected nonferrous metals on their tribological behavior in the [LN.sub.2] environment, we have studied the friction and wear properties of high purity copper (Cu) and titanium (Ti) against the bearing grade steel. These two materials have been processed to produce samples of comparable hardness that have widely different thermal conductivities at room temperature and at test temperature. Wear tests were conducted at three different sliding speeds (0.89 m/s, 1.11 m/s, and 1.34 m/s) under 10 N load, and the friction and wear data were compared. Ti exhibited an order of magnitude higher wear rate (~[10.sup.-3] [mm.sup.3]/N m) as compared with Cu in identical test conditions. While evidences of abrasive wear and adhesive wear, without any oxidative wear, were found in worn Cu surfaces, worn Ti surfaces showed evidences of significant oxidative wear and mechanical damage of tribolayers. Higher wear rate in Ti appeared to be a result of oxidative wear of Ti, which seemed to be driven by the depletion of [LN.sub.2] blanket at the tribocontacts under the influence of high flash temperature (14-76 [degrees]C) as compared with the boiling temperature of [LN.sub.2] (-196[degrees]C). These results demonstrate that the materials with similar hardness subjected to identical [LN.sub.2] wear test conditions can have significantly different wear rates because of the difference in the flash temperatures, which depend on the thermal conductivity of the test pieces. [DOI: 10.1115/1.4002503] Keywords: cryogenic wear, titanium, copper, flash temperature

During the reflood phase, following a loss-of-coolant-accident (LOCA), the main mechanism for the precursory cooling of the fuel is by convective heat transfer to the vapor, with the vapor being cooled by the evaporation of the entrained saturated droplets. However, it is believed that the droplets that reach the rod could have an effect on this cooling process. Despite the fact that those droplets do not actually wet the fuel rod due to the formation of a vapor film that sustains them and prevents them from touching the wall, the temperature drop caused by the impingement of such water droplets on a very hot solid surface (whose temperature is beyond the Leidenfrost temperature (1966, 'A Track About Some Qualities of Common Water, ' Int. J. Heat Mass Transfer, 9, pp. 1153-1166)) is of the order of 30-150[degrees]C (2008, The Role of Entrained Droplets in Precursory Cooling During PWR Post-LOCA Reflood, TOPSAFE, Dubrovnik, Croatia, 1995, 'Heat Transfer During Liquid Contact on Superheated Surfaces,' ASME J. Heat Transfer, 117, pp. 693-697). The associated heat flux is of the order of [10.sup.5]-[10.sup.7] W/[m.sup.2] and the heat extracted is in the range of 0.05 J over the time period of the interaction (a few ms) (2008, The Role of Entrained Droplets in Precursory Cooling During PWR Post-LOCA Reflood, TOPSAFE, Dubrovnik, Croatia, 1995, 'Heat Transfer During Liquid Contact on Superheated Surfaces,' ASME J. Heat Transfer, 117, pp. 693-697). The hydrodynamic behavior of the droplets upon impingement is reported to affect the heat transfer effectiveness of the droplets. In the dispersed flow regime the droplets are more likely to impinge on the hot surface at a very small angle sliding along the solid wail still without actually touching it, and remaining in a close proximity for a much larger time period. This changes the heat transfer behavior of the droplet. Here, we investigate numerically the hydrodynamics of the impingement of such droplets on a hot solid surface at various incident angles and various velocities of approach. For our simulations, we use a computational fluid dynamics (CFD), finite-volume computational algorithm (TransAT[c]). The level set method is used for the tracking of the interface. We present three-dimensional results of those impinging droplets. The validation of our simulation is done against experimental data already available in the literature. Then, we compare the findings of those results with previous correlations. [DOI: 10.1115/1.4000867]

Sesame (Sesamum indicum L) is one of the oldest cultivated plants. Its seed contains about 42-54% quality oil, 22-25% protein, 20-25% carbohydrates and 4-6% ash. This composition varies with genetic and environmental factors. Conditioning of oil seeds which include roasting, flaking, size reduction, cooking, pre-pressing and drying, is an important operation in the production line of sesame oil. This work investigated effects of initial moisture content, roasting duration and temperature on initial Peroxide Value (PV) and Oxidative Stability (OS) of un-refined sesame oil using response surface methodology. Goza-25, a variety of sesame seed that is commercially cultivated in Nigeria was used for the study. Initial moisture content levels were 4, 7, 10, 13 and 16% wet basis (wb). Roasting duration and temperature levels were 5, 10, 15, 20 and 25 minutes, and 50, 70, 90, 110 and 130 °C respectively. The recorded minimum and maximum PV were 3.9 and 15.4 meq/kg respectively. Mean value was 9.85 ± 3.9 meq/kg. Peroxide value increased with increasing moisture content and reduced with increasing roasting duration. Analysis of variance and regression analysis of obtained data showed that application of quadratic model to predict effect of initial moisture content, roasting duration and temperature on peroxide value is significant at p ≤ 0.05. Within the studied range, 13 h was the minimum OS recorded while maximum were 63.3 h. Mean of the data was 38.37 ± 16.02. Using the conversion factor of one hour of an active oxygen hour as being equivalent to 15 days; the expressed sesame oil in its present form will retain its quality for a maximum period of 949 days. Rise in roasting temperature and duration increased the oxidative stability, a reverse was observed with initial moisture content. High moisture content reduced the quality and storage life while heat treatment increased both the initial quality and storage life of the mechanically expressed oil. Peroxide value and oxidative stability of crude sesame oil significantly (p ≤ 0.05) depend on moisture content of the seed, roasting duration and temperature. Key words: Sesame, Oil, Crude, Oxidation, Storage, INTRODUCTION Sesame (Sesamum indicum L) also known as sesamum, gingelly, sim sim, beniseed and til is the one of the oldest cultivated plants [1]. Its seed contains about 42-54% quality [...]

The nontrivial issues associated with calculating the steady state heat spreading effects generated by a heat source on top of a multilayer assembly such as a printed circuit board are discussed. It is argued that problems arise with the interpretation of heat spreading effects due to a misconception about the meaning of often-quoted flux limits and especially the physical meaning of thermal resistance. The usefulness of a number of approaches that are generally in use to analyze heat spreading effects is discussed and it is shown that the popular series-resistance approach has severe limitations. A number of test cases are covered in detail and the results testify to this assertion. [DOI: 10.1115/1.4001856]

There are two important factors that accompany heat-induced shrinkage of collagenous tissues: mechanical property degradation and partial recovery from the shrunken length (elongation) upon returning to room temperature (defined here as acute recovery). These undesirable factors reduce the efficacy of thermal therapies. We applied chemical cross-linking adjuvant to thermal treatment on New Zealand White rabbit patellar tendon complexes to explore the feasibility of reducing the impact of these undesirable side-effects. Our results have shown that with exposure to 0.5% w/v glutaraldehyde solution during heating, the recovery response of the patellar tendon tissue was decreased, and the mechanical properties of the tissue were significantly improved. [DOI: 10.1115/1.4001924]

Natural convection in macroscopically immobile solutions may still alter electrochemical experiments performed with electrodes of micrometric dimensions. A model accounting for the influence of natural convection allowed delineating conditions under which it interferes with mass transport. Several electrochemical behaviors may be observed according to the time scale of the experiment, electrode dimensions, and intensity of natural convection. The range of parameters in which ultramicrelectrodes behave under a hue diffusional steady state was identified. Mapping of concentration profiles was performed experimentally by scanning electrochemical microscopy in the vicinity of microelectrodes of various radii. The results validated remarkably the predictions of the model, evidencing in particular the alteration of the diffusional steady state by natural convection. 10.1021/ac101210r

Starting from the conservation laws for mass, momentum, and energy together with a three-species bulk microphysics model, a model for the interaction of internal gravity waves and deep convective hot towers is derived using multiscale asymptotic techniques. From the leading-order equations, a closed model for the large-scale flow is obtained analytically by applying horizontal averages conditioned on the small-scale hot towers. No closure approximations are required besides adopting the asymptotic limit regime on which the analysis is based. The resulting model is an extension of the anelastic equations linearized about a constant background flow. Moist processes enter through the area fraction of saturated regions and through two additional dynamic equations describing the coupled evolution of the conditionally averaged small-scale vertical velocity and buoyancy. A two-way coupling between the large-scale dynamics and these small-scale quantities is obtained: moisture reduces the effective stability for the large-scale flow, and microscale up- and downdrafts define a large-scale averaged potential temperature source term. In turn, large-scale vertical velocities induce small-scale potential temperature fluctuations due to the discrepancy in effective stability between saturated and nonsaturated regions. The dispersion relation and group velocity of the system are analyzed and moisture is found to have several effects: (i) it reduces vertical energy transport by waves, (ii) it increases vertical wavenumbers but decreases the slope at which wave packets travel, (iii) it introduces a new lower horizontal cutoff wavenumber in addition to the well-known high wavenumber cutoff, and (iv) moisture can cause critical layers. Numerical examples reveal the effects of moisture on steady-state and time-dependent mountain waves in the present hot-tower regime. DOI: 10.1175/2010JAS3269.1

We examine the effect of photodarkening-induced pump light absorption on Yb-doped fiber thermal loading. In these experiments, the fiber is cladding pumped at 915 nm, air cooled by natural convection, and monitored with a midinfrared thermal camera. The fiber temperature is found to correlate with progressive photodarkening. The maximum observed fiber temperature was 120 [degrees]C, recorded at a pump power of 10.5 W. The observed increase in fiber temperature can be explained by a model that takes into account the combined effects of the Yb-silica quantum defect, the temperature dependence of the Yb-absorption cross section, and photodarkening-induced loss at 915 nm. We hypothesize that the latter effect results in the progressive activation of temperature-dependent photochemical processes (e.g., bleaching) and is ah important consideration with regard to the accurate modeling of Yb-doped fiber photodarkening kinetics. OCIS codes: 140.3510, 160.5690, 140.6810, 140.3615.

An explanation for high-frequency cycles of sea level in non-glacial times has remained elusive, despite more than two centuries of research since Lavoisier's seminal observations were published in 1789. In the development of seismic stratigraphy in the 1970s, putatively global high-frequency changes in relative sea level (Vail third-order cycles) were attributed to an unknown eustatic mechanism, prompting a search for Mesozoic ice ages. Over the last decade, a regional mechanism of sea-level control has been developed from studies of the sedimentary record in high-quality oil-industry data. These geological studies have supported the geophysical prediction that significant regional control of sea level is exercised by mantle-induced vertical motions of the Earth's surface. These vertical motions can occur over time intervals from several tens of million years to less than a million years, with amplitudes of tens of metres or more even at the shorter intervals. The vertical motions are not confined to regions with major hotspots. There are two related controls of surface vertical motion: evolution of mantle-convection cells, and pulsing flow within each cell. The effects are evident in the sedimentary record of North Atlantic basins. Mantle convection provides an alternative, regional, mechanism to eustatic control for explaining medium-frequency to high-frequency sea-level cycles. doi: 10.1144/0016-76492009-127.

Problem statement: Jet impingement quenching has a very effective and large cooling potential and is a very effective means of cooling for many applications. It gives rise to heterogeneous and/or homogeneous nucleation of bubbles, which is yet to be explored. Approach: Analytically investigate the phenomenon that happened during a brief contact of a water jet impinging on a hot surface. In particular, explore the possibility of homogeneous bubble formation during jet impingement quenching. A simple semi-infinite conduction heat transfer model was considered in this case and the heat transfer analysis had been carried out for two heating cases of the impinging liquid, namely with (i) Prescribed Surface Temperature (PST-case) and (ii) Time-dependent Surface Temperature (TST-case). For each of above cases, explicit equations for temperature distribution within liquid, average liquid temperature, average internal energy and surface heat flux had been derived as a function of liquid depth and contact time. These equations were solved numerically and their outcomes were discussed. Furthermore, a critical contact time, t * at which the temperature on the opposite side of the liquid depth reached saturation temperature, [T.sub.sat] was determined. The heat flux ([q.sub.s]) at time t * was also determined and compared with the thermodynamic limit of the maximum heat flux ([q.sub.max]) which decided the validity of this analytical investigation. Results: During jet impingement quenching of hot surfaces near/above the thermodynamic limiting temperature, water stored enough energy for a contact period of 5-10 [micro]s depending on the type of boundary conditions considered for triggering homogeneous bubble nucleation. A contact time of 4[micro]s was required to trigger homogeneous bubble nucleation for the conditions where the impinging surface had a fixed temperature throughout the cooling process. A contact time of 6.5 [micro]s was required to initiate homogeneous bubble nucleation for the conditions where the impinging surface temperature dropped at a rate depending on time. For both cases, the average internal energy of the liquid exceeded the minimum energy necessary for bubble formation. Moreover, the average heat flux, q never exceeded the thermodynamic limit of the maximum heat flux, [q.sub.max]. Conclusion: When water was heated above the thermodynamic limit of superheat during jet impingement, there is always a chance of homogeneous bubble nucleation. Key words: Homogeneous nucleation of bubbles, heat conduction, jet impingement quenching, semiinfinite solid, thermodynamic limit of liquid superheat, INTRODUCTION Jet impingement quenching has a very effective and large cooling potential and is a very effective means of cooling for many applications. It is very important in Loss Of [...]

The study of heat and moisture flows in multiple layers of different materials that make up the unsaturated zone is of great importance when characterizing the behaviour of these materials. In the present paper, analytical solutions of the one-dimensional heat and moisture coupled diffusion problem for layered materials under two different sets of boundary conditions are proposed. The coupled flow of heat and moisture are assumed to follow the theory of Philip and De Vries, and the solutions are derived analytically using integral transform methods. A comparison between the analytical and numerical solutions for one example problem shows satisfactory results. Furthermore, a procedure is presented for estimating heat and moisture distribution profiles in any layered materials using the derived analytical solutions. It is expected that the proposed analytical solutions will be used effectively for preliminary analyses of coupled heat and moisture movements in unsaturated porous media. Key words: heat and moisture coupled diffusion problem, layered materials. Lors de la caraclerisation du comporiemeni de differenls materiaux qui composent la zone non saturee, l'etude de l'ecoulement de la chaleur et de l'humidite dans les couches multiples de ces materiaux est particulifiremeni importante. Dans cet article, nous proposons des solutions analytiques pour la diffusion unidimensionnelle de la chaleur et de l'humidite de facon couplee pour des materiaux ayant plusieurs couches et sous deux types de conditions frontieres differentes. L'ecoulement couple de la chaleur et de l'humidite suit la theorie de Philip et De Vries et les solutions sont derivees de facon analytique a l'aide de methodes de transformation d'integrales. Les resultats d'un exemple de probleme obtenus a l'aide des solutions analytiques et numeriques ont ete compares, et la comparaison s'est averee satisfaisante. De plus, une procedure est presentee permettant d'estimer les profils de distribution de la chaleur et de I'humidite dans un materiau a plusieurs couches a l'aide des solutions analytiques derivees. Les solutions analytiques proposees pounonl eire utilisees dans les analyses preliminaires des mouvements couples de chaleur et d'humidite dans les milieux poreux non satures. Mots-cles : probleme de diffusion couplee de chaleur et d'humidite, materiaux a couches. [Traduit par la Redaction], Introduction The coupled processes of heat transfer and moisture movement in unsaturated materials are of interest to many scientists and engineers in the fields of soil physics, agricultural science, rock [...]

The flow characteristics and heat transfer are studied in a vertical annulus of a heated cylinder surrounded by a permeable cylinder, subject to cross uniform wind with open end to the environment and in the presence of natural convection. The objective here is to develop a computationally efficient model capable of capturing the physics of the flow and heat transport to predict air renewal rates in the vertical annulus. The small quantities of air infiltrating/exfiltrating through the porous cylinder over its upstream/ downstream regions do not substantially affect the external flow pattern around the clothed cylinder. The air annulus flow and heat transport model predicted the radial and vertical mass fluxes and the mass flow rate at the opening as a function of environment conditions, porous cylinder thermal properties, wind speed, and annulus geometry. Experiments were performed in a low speed wind tunnel (0.5-5 m/s), in which an isothermally heated vertical cylinder surrounded by a clothed outer cylinder was placed in uniform cross wind. The tracer gas method is used to predict total ventilation flow rates through the fabric and the opening. Good agreement was found between the model and experimental measurements of air renewal rate and predicted heat loss from the inner cylinder at steady conditions. A parametric study is performed to study the effect of wind speed and temperature difference between the wind and skin temperature on induced ventilation through the clothing and the opening. It is found that natural convection enhances ventilation of the annulus air at wind speed, less than 3 m/s, while at higher speeds, natural convection effect is negligible. As the temperature difference between external wind and inner cylinder surface increases, the vertical air temperature gradient and total upward airflow through the opening increase. [DOI: 10.1115/1.4000429] Keywords: mixed convection in vertical annulus, clothed vertical heated cylinder ventilation, airflow through porous cylinder

Tracers are used in a large-eddy simulation of shallow convection to show that stochastic entrainment (and not cloud-base properties) determines the fate of convecting parcels. The tracers are used to diagnose the correlations between a parcel's state above the cloud base and both the parcel's state at the cloud base and its entrainment history. The correlation with the cloud-base state goes to zero a few hundred meters above the cloud base. On the other hand, correlations between a parcel's state and its net entrainment are large. Evidence is found that the entrainment events may be described as a stochastic Poisson process. A parcel model is constructed with stochastic entrainment that is able to replicate the mean and standard deviation of cloud properties. Turning off cloud-base variability has little effect on the results, which suggests that stochastic mass-flux models may be initialized with a single set of properties. The success of the stochastic parcel model suggests that it holds promise as the framework for a convective parameterization. DOI: 10.1175/2009JAS3307.1

Atmospheric gravity waves have a major effect on atmospheric circulation, structure, and stability on a global scale. Gravity waves can be generated by convection, but in many cases it is difficult to link convection directly to a specific wave event. In this research, the authors examine an event on 12 January 2003 when convective waves were clearly generated by a period of extremely intense rainfall in the region of Darwin, Australia, during the early morning. The waves were observed by the Atmospheric Infrared Sounder (AIRS) instrument on board the Aqua satellite, and a dry version of a nonlinear, three-dimensional mesoscale cloud-resolving model is used to generate a comparable wave field. The model is forced by a spatially and temporally varying heating field obtained from a scanning radar located north of Darwin at Gunn Point. With typical cloud-resolving model studies it is generally not possible to compare the model results feature-for-feature with observations since although the model precipitation and small-scale heating may be similar to observations, they will occur at different locations and times. In this case the comparison is possible since the model is forced by the observed heating pattern. It is shown that the model output wave pattern corresponds well to the wave pattern observed by the AIRS instrument at the time of the AIRS overpass. DOI: 10.1175/2009JAS3197.1

Thermal conductivity measurement is a quick and easy test for compacted soils. This study presents the results of thermal conductivity testing on silt compacted under standard and modified Proctor efforts. A comparison of moisture content measurements from both lab oven and field oven is also presented and discussed. Measured thermal conductivity was correlated to the bulk density and water content. It is further correlated to Young's modulus and Shear modulus of the compacted silt, which were determined through ultrasonic pulse velocity measurements. Several trends were observed which may be used to correlate soil thermal conductivity of the compacted silt to compaction and elastic moduli for quality control/quality assurance of compacted soil. DOI: 10.1061/(ASCE)MT.1943-5533.0000035 CE Database subject headings: Fiber reinforced polymer; Composite materials; Sustainable development; Silts; Elasticity; Compacted soils. Author keywords: Thermal conductivity; Compacted silts; Elastic modulus.

Thermal conductivity of the Earth's lower mantle greatly impacts the mantle convection style and affects the heat conduction from the core to the mantle. Direct laboratory measurement of thermal conductivity of mantle minerals remains a technical challenge at the pressure-temperature (P-T) conditions relevant to the lower mantle, and previously estimated values are extrapolated from low P-T data based on simple empirical thermal transport models. By using a numerical technique that combines first-principles electronic structure theory and Peierls--Boltzmann transport theory, we predict the lattice thermal conductivity of MgO, previously used to estimate the thermal conductivity in the Earth, at conditions from ambient to the core-mantle boundary (CMB). We show that our first-principles technique provides a realistic model for the P-T dependence of lattice thermal conductivity of MgO at conditions from ambient to the CMB, and we propose thermal conductivity profiles of MgO in the lower mantle based on geotherm models. The calculated conductivity increases from 15-20 W/K-m at the 670 km seismic discontinuity to 40-50 W/K-m at the CMB. This large depth variation in calculated thermal conductivity should be included in models of mantle convection, which has been traditionally studied based on the assumption of constant conductivity. first-principles | phonon transport theory | phonon lifetime | high pressure | Lower Mantle www.pnas.org/cgi/doi/10.1073/pnas.0907194107

Convectively forced mesoscale flows in a shear flow with a critical level are theoretically investigated by obtaining analytic solutions for a hydrostatic, nonrotating, inviscid, Boussinesq airflow system. The response to surface pulse heating shows that near the center of the moving mode, the magnitude of the vertical velocity becomes constant after some time, whereas the magnitudes of the vertical displacement and perturbation horizontal velocity increase linearly with time. It is confirmed from the solutions obtained in present and previous studies that this result is valid regardless of the basic-state wind profile and dimension. The response to 3D finite-depth steady heating representing latent heating due to cumulus convection shows that, unlike in two dimensions, a low-level updraft that is necessary to sustain deep convection always occurs at the heating center regardless of the intensity of vertical wind shear and the heating depth. For deep heating across a critical level, little change occurs in the perturbation field below the critical level, although the heating top height increases. This is because downward-propagating gravity waves induced by the heating above, but not near, the critical level can hardly affect the flow response field below the critical level. When the basic-state wind backs with height, the vertex of V-shaped perturbations above the heating top points to a direction rotated a little clockwise from the basic-state wind direction. This is because the V-shaped perturbations above the heating top is induced by upward-propagating gravity waves that have passed through the layer below where the basic-state wind direction is clockwise relative to that above. DOI: 10.1175/2009JAS3110.1

Fire lines are complex phenomena with a broad range of scales of cross-line dimension, undulations, and along-line variation in heating rates. While some earlier studies have examined parcel processes in two-dimensional simulations, the complexity of fire lines in nature motivates a study in which the impact of three-dimensional fire line details on parcel processes is examined systematically. This numerical modeling study aims to understand how fundamental processes identified in 2D simulations operate in 3D simulations where the fire line is neither straight nor uniform in intensity. The first step is to perform simulations in a 3D model, with no fire line undulations or inhomogeneity. In general, convective modes simulated in the 2D model are reproduced in the 3D model. In one particular case with strong vertical wind shear, new convection develops separate from the main line of convection as a result of local changes to parcel speed and heating. However, in general the processes in the 2D and 3D simulations are identical. The second step is to examine 3D experiments wherein fire line shape and along-line inhomogeneity are varied. Parcel heating, as well as convective mode, is shown to exhibit sensitivity to fire line shape and along-line inhomogeneity. DOI: 10.1175/2009JAS3226.1

As global warming entails new conditions for the built environment, the thermal and energy performance of existing buildings, which are designed based on current weather data, may become unclear and remain a great concern. Through building computer simulation and qualitative analysis of the weighted factor for the outdoor temperature impact on building energy and thermal performance, this paper investigates the sensitivity of different office building zoning to the potential global warming. A standard office building type is examined for all eight capital cities in Australia. Results show that comparing the middle and top floors, except for cool climate (i.e. Hobart), the ground floor appears to be the most sensitive to the effect of global warming and has the highest tendency for a overheating problem. From the analysis of the responses of different zone orientations to the outdoor air temperature increase, it is also found that there are widely varied responses between zone orientations, with South zone (in the southern hemisphere) being the most sensitive. With an increased external air temperature, the variation between different floors or zone orientations will become more significant, up to 53 percent increase of overheating hours in Darwin and 47 percent increase of cooling load in Hobart. Keywords: Building form, Building performance, Global warming, Office building, Zone type, Introduction Greenhouse gas emissions and associated global warming is a significant concern for the world community. This problem is now widely recognised as having significant potential to seriously affect the [...]

Problem statement: Earlier work on ohmic heating technique focused on viscous food and foods containing solid particles. In this study, the use of ohmic heating on sterilization of guava juice is carried out. Computational fluid dynamics is used to model and simulate the system. Approach: Investigate the buoyancy effect on the CFD simulation of continuous ohmic heating systems of fluid foods. A two-dimensional model describing the flow, temperature and electric field distribution of non-Newtonian power law guava juice fluid in a cylindrical continuous ohmic heating cell was developed. The electrical conductivity, thermo physical and rheological properties of the fluid was temperature dependent. The numerical simulation was carried out using FLUENT 6.1 software package. A user defined functions available in FLUENT 6.1 was employed for the electric field equation. The heating cell used consisted of a cylindrical tube of diameter 0.05 m, height 0.50 m and having three collinear electrodes of 0.02 m width separated by a distance of 0.22 m. The sample was subjected to zero voltage at the top and bottom of electrodes while electrical potential of 90 volts (AC 50-60 Hz) was set at the middle electrode. The inlet velocity is 0.003 m [sec.sup.1] and the temperature is in the range of 30-90[degrees]C. Results: The simulation was carried with and without buoyancy driven force effect. The ohmic heating was successfully simulated using CFD and the results shows that the buoyancy has a strong effect in temperature profiles and flow pattern of the collinear electrodes configuration ohmic heating. A more uniform velocity and temperature profiles were obtained with the buoyancy effect included. Conclusion: For accurate results, the inclusion of buoyancy effect into the CFD simulation is important. Key word: CFD numerical modeling, 2D ohmic heating, Natural convection, guava juice, INTRODUCTION Ohmic heating is a developing technology with considerable potential for the food industry. The main advantages of ohmic processing are the rapid and relatively uniform heating achieved, together with [...]

Buoyancy and velocity scales for dry convection in statistical equilibrium were derived in the early twentieth century by Prandtl, but the scaling of convective velocity and buoyancy, as well as the fractional area coverage of convective clouds, is still unresolved for moist convection. In this paper, high-resolution simulations of an atmosphere in radiative-convective equilibrium are performed using the Weather Research and Forecasting (WRF) model, a three-dimensional, nonhydrostatic, convection-resolving, limited-area model. The velocity and buoyancy scales for moist convection in statistical equilibrium are characterized by prescribing different constant cooling rates to the system. It is shown that the spatiotemporal properties of deep moist convection and buoyancy and velocity scales at equilibrium depend on the terminal velocity of raindrops and a hypothesis is developed to explain this behavior. This hypothesis is evaluated and discussed in the context of the numerical results provided by the WRF model. The influence of domain size on radiative-convective equilibrium statistics is also assessed. The dependence of finescale spatiotemporal properties of convective structures on numerical and physical details is investigated. DOI: 10.1175/2009JAS3103.1

This study compares two models that differ primarily in their cloud parameterizations and produce extremely different simulations of the Madden-Julian oscillation (MJO). The Community Atmosphere Model (CAM) version 3.0 from NCAR uses the Zhang-McFaflane scheme for deep convection and does not produce an MJO. The 'superparameterized' version of the CAM (SP-CAM) replaces the cloud parameterizations with a two-dimensional cloud-resolving model (CRM) in each grid column and produces an extremely vigorous MJO. This analysis shows that the CAM is unable to produce high-humidity regions in the mid- to lower troposphere because of a lack of coupling between parameterized convection and environmental relative humidity. The SP-CAM produces an overly moist column due in part to excessive near-surface winds and evaporation during strong convective events. In the real tropics and the SP-CAM, convection within a highhumidity environment produces intense latent heating, which excites the large-scale circulation that is the signature of the MJO. The authors suggest that a model must realistically represent convective processes that moisten the entire tropical troposphere in order to produce a simulation of the MJO. DOI: 10.1175/2009JAS3081.1

This study examines the seasonal and diurnal dynamics of convective cloud entities--small cells and a mesoscale convective complex-like pattern--in the foothills of the tropical eastern Andes. The investigation is based on Geostationary Operational Environmental Satellite-East (GOES-E) satellite imagery (2005-07), images of a scanning X-band rain radar, and data from regular meteorological stations. The work was conducted in the framework of a major ecological research program, the Research Unit 816, in which meteorological instruments are installed in the Rio San Francisco valley, breaching the eastern Andes of south Ecuador. GOES image segmentation to discriminate convective cells and other clouds is performed for a 600 x 600 [km.sup.2] target area, using the concept of connected component labeling by applying the 8-connectivity scheme as well as thresholds for minimum blackbody temperature, spatial extent, and eccentricity of the extracted components. The results show that the formation of convective clouds in the lowland part of the target area mainly occurs in austral summer during late afternoon. Nocturnal enhancement of cell formation could be observed from October to April (particularly February--April) between 0100 and 0400 LST (LST = UTC - 5 h) in the Andean foothill region of the target area, which is the relatively dry season of the adjacent eastern Andean slopes. Nocturnal cell formation is especially marked southeast of the Rio San Francisco valley in the southeast Andes of Ecuador, where a confluence area of major katabatic outflow systems coincide with a quasi-concave shape of the Andean terrain line. The confluent cold-air drainage flow leads to low-level instability and cellular convection in the warm, moist Amazon air mass. The novel result of the current study is to provide statistical evidence that, under these special topographic situations, katabatic outflow is strong enough to generate mainly mesoscale convective complexes (MCCs) with a great spatial extent. The MCC-like systems often increase in expanse during their mature phase and propagate toward the Andes because of the prevailing upper-air easterlies, causing early morning peaks of rainfall in the valley of the Rio San Francisco. it is striking that MCC formation in the foothill area is clearly reduced during the main rainy season [June--August (JJA)] of the higher eastern Andean slopes. At a first glance, this contradiction can be explained by rainfall persistence in the Rio San Francisco valley, which is clearly lower during the time of convective activity (December--April) in comparison with JJA, during which low-intensity rainfall is released by predominantly advective clouds with greater temporal endurance.

We propose a new numerical model to analyze heat induced by two-photon absorption and free-carrier absorption, while high intensity optical pulses propagate along silicon-on-insulator (SOI) nanowave-guides (NWGs). Using this model, we demonstrate that such induced heat causes a shift in the amount of wavelength conversion and hence deteriorates the converter output characteristics for pulses in the picosecond regime. The wavelength shift induced by a pulse with maximum input intensity and full width at half-maximum of [I.sub.max] = 1.5 X [10.sup.10] W.[cm.sup.-2] and [T.sub.FWHM] = 30 ps, propagating along a SOI NWG with an effective cross-sectional area of [a.sub.eff] = 0.15 [micro][m.sup.2], is shown to be [DELTA][[lambda].sub.s] = 8 pm. We also demonstrate that such a shift can be compensated by tuning the pump intensity down by approximately 6.33%. OCIS codes: 130.4705, 190.3270, 190.4360, 230.7370, 230.7405.

In this paper, a mathematical investigation on the effect of convective cooling on a reactive third-grade fluid flowing steadily through a cylindrical pipe is performed. It is assumed that the system exchange heat, with the ambient following Newton's cooling law and the reaction, is exothermic under Arrhenius kinetics, neglecting the consumption of the material. The simplified governing nonlinear equations of momentum and energy are obtained and solved using a special type of the Hermite--Pade approximation technique. The important properties of the overall flow structure including velocity field, temperature field, bifurcations, and thermal criticality conditions are discussed. [DOI: 10.1115/1.3086587] Keywords: cylindrical pipe, third-grade fluid, Arrhenius kinetics, thermal criticality, Hermite--Pade approximants, convective cooling

A method for measurement of temperature in laminar free convection flow of water is presented using digital holographic interferometry. The method is relatively simple and fast because the method uses lensless Fourier transform digital holography, for which the reconstruction algorithm is simple and fast, and also the method does not require use of any extra experimental efforts as in phase shifting. The quantitative unwrapped phase difference is calculated experimentally from two digital holograms recorded in two different states of water--one in the quiescent state, the other in the laminar free convection. Unknown temperature in laminar free convection is measured quantitatively using a known value of temperature in the quiescent state from the unwrapped phase difference, where the equation by Tilton and Taylor describing the variation of refractive index of water with temperature is used to connect the phase with temperature. Experiments are also performed to visualize the turbulent free convection flow. OCIS codes: 090.1760, 090.1995, 090.2880, 100.2000, 120.2880.

This paper presents a thin millimeter-scaled device that can generate a closed flow within itself with a velocity of the order of a few m/s. The device comprises a piezoelectric pump with a PZT membrane, housing chamber, and a closed network channel connected to the housing chamber through a specific throat. We investigate the device by computational fluid dynamics. This device is used to produce several free jet flows depending on the structure of the network channel In this study, four jet flows comprising two perpendicular pairs of flows are demonstrated. If the PZT membrane vibrates within a suitable range, the self-similarity of the axial velocity (along the jet direction) to the cross distances scaled by the half-widths of the jet is observed for a certain range of axial distance. Each jet flow can bend almost freely in three dimensions. The two remaining flow components are small as compared to the axial component. The device potentially has wide applications in flow-based sensors. [DOI: 10.1115/1.3089538] Keywords: microfluidics, micropumps, piezoelectrics, numerical simulation, free jet flows

It is well known that an isothermal dielectric liquid can be driven by electroconvection. It has been demonstrated that two phenomena could generate space charge in isothermal dielectric liquids and then induce a fluid movement. These two electroconvective effects are bulk conduction and ion injection. In order to improve the performance of electroconvective devices, the velocity of the flows must be recorded as accurately and precisely as possible. In this paper, the Particle Image Velocimetry (PIV) method that was originally developed in the field of experimental fluid mechanics is adapted to electroconvective flow measurements. The choice and the size of seeding particles are discussed. The influence of the seeding particles density on the current is measured. In this work, experiments were investigated on a typical two-dimensional charged plume flow produced between a blade and a flat plate. Both negative and positive polarities are also investigated. Index Terms--Blade-plane geometry, charged plume, dielectric liquid, electrohydrodynamics, particle image velocimetry.

A breadboard GC detector based on Penning ionization electron spectroscopy in plasma (PIES) was investigated. The PIES detector was set up in series with a gas chromatograph and a thermal conductivity detector. Two-dimensional PIES chromatograms were recorded for carbon monoxide, carbon dioxide, and methane. The analytes were identified independently of the GC retention time, and their concentrations were measured in a range between I and 100 ppm. PIES spectra for methane were observed for the first time and displayed two characteristic peaks with electron energies of 7.1 and 5.4 eV. Rate coefficients for Penning ionization due to collisions between [2.sup.3]S helium metastable atoms and analyte molecules under study were found to be [k.sup.*.sub.co] = (0.7 [+ or -] 0.2) x [10.sup.-10], [k.sup.*.sub.co2] = (1.8 [+ or -] 0.7) x [10.sup.-10], [k.sup.*.sub.7.1 CH4] = (4.7 [+ or -] 0.6) x [10.sup.-10], and [k.sup.*.sub.5.4 CH4] = (8 [+ or -] 2) x [10.sup.-10] [cm.sup.3]/s. The work provides the basis for the development of a portable and robust analytical platform capable of in situ real-time monitoring of greenhouse gases, with a perspective toward laboratory-on-chip realization.

A photothermal experiment with mirage detection was used to determine the thermal conductivity of various thin films deposited on semiconductor substrates. The first type consisted of conducting oxide films: ZnO and CdO deposited on GaSb:Te, while the other contained high dielectric constant Hf[O.sub.2] layers on Si. All films were fabricated using a magnetron sputtering technique. Experimental results showed that the value of the thermal conductivity of ZnO and CdO films is lower than the value obtained for Hf[O.sub.2]. Thermal conductivities of investigated thin films are about 2 orders of magnitude lower than those corresponding to bulk materials. OCIS codes: 310.0310, 310.6870, 310.7005, 310.1210.

This paper reports the design study performed on a heat conduction panel having several heat sources at separate locations and a heat sink on one of the panel corners. The panel is given a thickness distribution so as to provide spatially varying heat conduction paths from the heat sources to the heat sink. The objective of thickness distribution design is to reduce the variation among heat source temperatures and the maximum heat source temperature simultaneously. The genetic algorithm is used to search for an optimum thickness distribution. The problem is a generic representation of the situations that are becoming common in a compact electronic equipment. [DOI: 10.1115/1.2993137] Keywords: heat conduction path design, multiple heat sources, displaced heat sink, genetic algorithm application

The first ~600 million years of Earth history (the 'Hadean' eon) remain poorly understood, largely because there is no rock record dating from that era. Detrital Hadean igneous zircons from [...]

In this study, natural convection heat transfer in a vertical flat-plate solar air heater of 2.5 m height and 1 m width, with one- and two-glass covers was studied experimentally. Totally six cases of airflow (two for air heater with one glass cover and four for air heater with two-glass covers) were considered. These cases included states that air could flow within spaces between absorber plate and glass covers or air was enclosed in such spaces. Absorber plate temperature, back-plate temperature, glass cover temperatures, mass flow rates of air within channels and the solar radiation were measured. The following relations are suggested: For channels in which air could flow: Nu = [0.7362Ra.sup.0.2579] For enclosures: Nu = [0.1377Ra.sup.0.2229] In the first relation, the characteristic length in Ra and Nu is the height of the air heater and in the second relation this length is the distance between the two vertical plates. The efficiency of the air heater was determined in various cases. The maximum efficiency was found for when the air heater had two glass covers and air could flow in all channels. Keywords: Solar energy; Flat plate solar air heater; Natural convection; Heat transfer coefficient; Experimental method

By means of a fundamental solution for a single inhomogeneity embedded in a functionally graded material matrix, a self-consistent model is proposed to investigate the effective thermal conductivity distribution in a functionally graded particulate nanocomposite. The 'Kapitza thermal resistance' along the interface between a particle and the matrix is simulated with a perfect interface but a lower thermal conductivity of the particle. The results indicate that the effective thermal conductivity distribution greatly depends on Kapitza thermal resistance, particle size, and degree of material gradient. [DOI: 10.1115/1.2936893] Keywords: functionally graded nanocomposites, effective thermal conductivity, self-consistent method, Kapitza thermal resistance, heat conduction

Abstract: A Transparent Water Storage Envelope (TWSE) is an innovative curtain wall system being developed to improve the overall energy efficiency of commercial buildings by means of minimizing the cooling [...]

Thermal conduction mechanism of heat transfer of nickel tape immersed in liquid nitrogen and heated by a step-like direct current is studied. The heat transfer by thermal conduction into liquid nitrogen is significant.

Magnetohydrodynamics natural convection in an inclined enclosure with a partition is studied numerically using a differential quadrature method. Governing equations for the fluid flow and heat transfer are solved for the Rayleigh number varying from [10.sup.4] to [10.sup.6], the Prandtl numbers (0.1, 1, and 10), four different Nartmann numbers (0, 25, 50, and 100), the inclination angle ranging from 0 deg to 90 deg, and the magnetic field with the x and y directions. The results show that the convective flow weakens considerably with increasing magnetic field strength, and the x-directional magnetic field is more effective in reducing the convection intensity. As the inclination angle increases, multicellular flows begin to develop on both sides of the enclosure for higher values of the Hartmann number if the enclosure is under the x-directional magnetic field. The vorticity generation intensity increases with increase of Rayleigh number. On the other hand, increasing Hartmann number has a negative effect on vorticity generation. With an increase in the inclination angle, the intensity of vorticity generation is observed to shift to top left corners and bottom right corners. Vorticity generation loops in each region of enclosure form due to multicelluar flow for an x-directional magnetic field when the inclination angle is increased further. In addition, depending on the boundary layer developed, the vorticity value on the hot wall increases first sharply with increasing y and then begins to decrease gradually. For the high Rayleigh numbers, the average Nusselt number shows an increasing trend as the inclination angle increases and a peak value is detected. Beyond the peak point, the foregoing trend reverses to decrease with the further increase of the inclination angle. The results also show that the Prandtl number has only a marginal effect on the flow and heat transfer. [DOI: 10.1115/1.2829567] Keywords: natural convection, MHD, PDQ, enclosure, vorticity, stream function

The finescale structure and dynamics of cumulus, evolving from shallow to deep convection, and the accompanying changes in the environment and boundary layer over mountainous terrain were the subjects of a field campaign in July-August 2006. Few measurements exist of the transport of boundary layer air into the deep troposphere by the orographic toroidal circulation and orographic convection. The campaign was conducted over the Santa Catalina Mountains in southern Arizona, a natural laboratory to study convection, given the spatially and temporally regular development of cumulus driven by elevated heating and convergent boundary layer flow. Cumuli and their environment were sampled via coordinated observations from the surface, radiosonde balloons, and aircraft, along with airborne radar data and stereophotogrammetry from two angles. The collected dataset is expected to yield new insights in the boundary layer processes leading to orographic convection, in the cumulus-induced transport of boundary layer air into the troposphere, and in fundamental cumulus dynamics. This article summarizes the motivations, objectives, experimental strategies, preliminary findings, and the potential research paths stirred by the project.

Severe thunderstorms comprise an extreme class of deep convective clouds and produce high-impact weather such as destructive surface winds, hail, and tornadoes. This study addresses the question of how severe thunderstorm frequency in the United States might change because of enhanced global radiative forcing associated with elevated greenhouse gas concentrations. We use global climate models and a high-resolution regional climate model to examine the larger-scale (or 'environmental') meteorological conditions that foster severe thunderstorm formation. Across this model suite, we find a net increase during the late 21st century in the number of days in which these severe thunderstorm environmental conditions (NDSEV) occur. Attributed primarily to increases in atmospheric water vapor within the planetary boundary layer, the largest increases in NDSEV are shown during the summer season, in proximity to the Gulf of Mexico and Atlantic coastal regions. For example, this analysis suggests a future increase in NDSEV of 100% or more in locations such as Atlanta, GA, and New York, NY. Any direct application of these results to the frequency of actual storms also must consider the storm initiation. climate change | United States | convective storm

Gas microconvection is a strategic research area in transport phenomena since it is the basis for a wide range of miniaturized high-performance applications like microelectromechanical systems. The literature reveals that in the single-phase continuum regime, microconvection characteristics significantly differ from those in the conventionally sized channels. Deviations from the expected behavior have been attributed to scaling effects that surface at the microscale. For most gas microflow applications that are in the slip or early transition regimes, the analysis is further complicated by rarefaction and compressibility effects. Therefore, microslip flows are comprehensively reviewed to identify the implications of reported findings with respect to the validity of continuum-based models. Based on the synthesis of studies, the need to better demark the continuum and free-molecUlar flow regimes is revealed, which necessitates the identification of important nonrarefaction scaling effects. This would enable the Computationally inexpensive continuum models to be extended to higher Knudsen numbers. The analyses suggest that early transition regime behavior is characterized more by conjugate nonrarefaction scaling effects and higher order slip boundary conditions than purely by rarefaction. [2006-0146] Index Terms--Continuum, free molecular, Knudsen number, microchannel, microflow, microscale, rarefaction, scaling effect, slip flow, surface roughness, transition flow, variations in fluid properties.

The thermal conduction along the heated silicon probe tip and the polymer for finding indent formation conditions is presented by using a simple modeling approach. There is a steady state and transient indent formation.

The article presents the experimental data for forced-convection condensation of low-pressure steam on five integral-fin tubes with different fin spacing. Vapor velocities are reported to be an important controlling factor in heat-transfer process.

Multilevel 15-yr ECMWF Re-Analysis (ERA-15) and satellite-observed brightness temperature ([T.sub.b]) data for the period May-October 1992 are used to examine the horizontal and vertical structures of convectively coupled equatorial waves. Dynamical waves are isolated using a methodology developed previously. Composite structures of convectively coupled equatorial waves are obtained using linear regression/correlation between convection ([T.sub.b]) and dynamical structures. It is found that the relationship depends on the ambient flow and the nature of the convective coupling, and varies between off-equatorial-and equatorial-centered convection, different hemispheres, and seasons. The Kelvin wave structure in the Western Hemisphere is generally consistent with classic equatorial wave theory and has its convection located in the region of low-level convergence. In the Eastern Hemisphere the Kelvin wave tends to have convection in the region of enhanced lower-tropospheric westerlies and a tilted vertical structure. The Kelvin wave also tends to have a third peak in zonal wind amplitude at 500 hPa and exhibits upward propagation into the lower stratosphere. Lower-tropospheric westward-moving mixed Rossby--gravity (WMRG) and n = 1 Rossby (RI) wave structures and their relationship with convection are consistent with classic equatorial wave theory and the implied lower-tropospheric convergences. In the Eastern Hemisphere the WMRG and R1 waves have first baroclinic mode structures in the vertical. However, in the Western Hemisphere, the R1 wave has a barotropic structure. In the Eastern Hemisphere the R1 wave, like the Kelvin wave, tends to have equatorial convection in the region of enhanced lower-level westerlies, suggesting that enhanced surface energy fluxes associated with these waves may play an important organizing role for equatorial convection in this warm-water hemisphere. In the upper troposphere, eastward-moving Rossby-gravity (EMRG) and n = 1 gravity waves are found in the Eastern Hemisphere, and eastward-moving WMRG and R1 waves are found in the Western Hemisphere, suggestive of Doppler shifting of waves by the ambient flow.