Journal articles on the topic 'Matthew R. Holmes'

Resistivity, r (T), and Hall coefficient in weak (B < 1 T) magnetic fields, R (T), are investigated in Ca2Si and CaSi2 films at temperatures T between ~ 20 - 300 K. In CaSi2, r (T) is typical of metals increasing with T within the whole temperature range. On the other hand, the resistivity of Ca2Si is pertinent of semiconductors. Namely, it is activated below T ~ 200 K, exhibiting different slopes of ln r vs. T -1 plots at lower and higher T, and a weak increase between T ~ 200 - 300 K. Both materials demonstrate a complex dependence of R (T), including a change of the sign. Transport properties above have been analyzed assuming two groups of charge carriers, electrons and holes, contributing them.

In this paper, due to the effect of positively-charged screening holes, Coulomb potential energy 1/r is modified to be 1/rp, which is assumed to deviate slightly from the former. Using many-body perturbation theory, we obtain a simple analytic representation of the ground-state energy and correlation energy for a uniform electron gas. Our results agree with those obtained by the numerical and semi-analytic methods at low-density limit. Higher ground-state energies at high-density limit are calculated from our model. High order r expansion terms are found at high-density region. A curve of transition density versus p is drawn via the Misawa spin-scaling relation, which is in consistent with Perdew's study at low-density limit.

Within the framework of effective-mass approximation, the exciton states localized in cylindrical InGaN quantum dots (QDs) are investigated using a variational approach. The relationship between the exciton states and structural parameters of QDs with radius R and height L are studied in detail. The numerical results show that the exciton binding energy is sensitive to the ratio of R/L for a QD with a given volume. There is a maximum in the binding energy, where the electrons and holes are the most efficiently confined in the QDs with special structural parameters. The binding energy maximum can be obtained at about L = 1.7 nm for different QD volumes. The exciton binding energy and emission wavelength depend sensitively on structural parameters and the In content in the In x Ga 1-x N active layer. Our calculated emission wavelengths are in good agreement with experimental data.

X-ray absorption measurements have been made at the Cu L 3 and O K-edge on ( Hg 0.5 Bi 0.5) Sr 2( Ca 1-x Pr x) Cu 2 O 7-δ (x=0.35,0.50) and ( Hg 0.5 Bi 0.5) Sr 2( Ca 0.65 Nd 0.35)- Cu 2 O 7-δ superconducting systems. Our results clearly indicate that hole density decreases with increase in Pr content. The values of T c for Pr and Nd (x=0.35) systems are the same but the itinerant hole density is found to be larger in the latter case. In view of the fact that the density of holes depends more upon diamagnetic fraction than the T c in these superconducting systems, we can conclude that superconducting properties are different for these two cases.

Turbulent convection into stratified two-layer fluid systems in the presence of rotation has been investigated in a cylindrical laboratory tank. For a wide range of conditions the vertical stability of the flow depends only on the Richardson number Ri = g′h0/(B0R)2/3 (here, g′ = gδ ρi/ρ0 is the jump in the reduced gravity across the density interface, δ ρi is the jump in density itself, h0 is the depth of the top layer, B0 is the surface buoyancy flux and R is the radius of the source). We have found that for values of Ri greater than a critical value of Ric ≈ 11, the convective flow did not penetrate through the density interface, regardless of the values of the convective Rossby number Ro* = (B0/f3h02)1/2 of the flow (here f is the Coriolis parameter). In this case after the convective layer interacted with the density interface the mixed fluid, of intermediate density, propagated radially along the interface in the form of an intrusion. Later, if Ro* was less than approximately 5, mesoscale vortices with mean diameter D ≈ 8(RoR)2/3 and maximum swirl velocity v ≈ (B0R)1/3 were generated at the edge of this propagating front (here RoR = (B0/f3R2)1/2 is the Rossby number based on R). When Ri was less than 11, the convective flow eventually penetrated through the density interface and into the bottom layer. This occurred through the formation of discrete ‘convective holes’ beneath the source. At large values of Ro*, and at early times, one turbulent plume penetrated into the bottom layer from each hole. Later the initial holes coalesced to create one large lesion beneath the source.

The effective compliance moduli of a plate with a doubly periodic set of traction-free holes are considered. Attention is drawn to the perturbation form in which they are expressed by applying the complex variable methods in two-dimensional elasticity. This permits one to derive specific dimensionless combinations of the effective moduli, which are independent of the solid Poisson ratio. Using them saves computations of the structure moduli by FEM-like methods and helps one to evaluate their practical accuracy. Thus far, the only result of this kind has been observed numerically by Day, Snyder, Garboczi, and Thorpe (J. Mech. Phys. Solids. 40, pp. 1031–1051, 1992) and later proved by Cherkaev, Lurie, and Milton (Proc. R. Soc. London, Ser. A 458, pp. 519–529, 1992).

Thermally stimulated luminescence (TSL) of x-ray-induced defects in R-Ba–Cu–O (R = Gd, Ho, and Eu) has been measured. In the interval 25–400°C, Ho- and Eu-doped samples exhibit similar TSL with peaks at 65, 135, and 185°C. The GdBa2Cu3Ox has, in addition to the three aforementioned peaks, a maximum at 310°C. All TSL peaks are attributed to recombination of F+s – and F−s center electrons with Vs-type holes, requiring typical thermal activation energies 0.5–1.0 eV. Spectral emission data support this conclusion. Irreversible quenching of TSL is found to occur in each sample. It is postulated that adsorbed oxygen molecules interact with radiation-induced F+s and Fs centers to produce O−2 and O2−2 molecular ions, respectively, thereby reducing the surface oxygen vacancy concentration and quenching the luminescence. In addition to activation energies, other TSL parameters are extracted from the data. It is suggested that surface TSL in these oxide superconductors is independent of rare-earth dopant.

We study the t—J model with one hole and the frustrated Heisenberg J—J′ model in a square lattice. Specifically, we compute and compare for both, the doped and frustrated models, the dynamic spin-spin structure factor S(q, ω), and the B1g Raman scattering spectrum R(ω) at zero temperature. The behavior of these quantities differs between the t—J and the J—J′ models. We observe that both the B1g Raman spectrum as well as the structure factor for the t—J model are in qualitative agreement with experimental measurements while the corresponding results for the J—J′ model are not. These results indicate that the magnetic behavior of doped systems cannot be accurately modeled by a purely spin Hamiltonian. These results are of relevance to the claim that the effect of adding holes (doping) on the magnetic properties of the quantum Heisenberg antiferromagnet can be described by introducing second and sometimes third nearest-neighbor couplings, J′ and J″ respectively, in the original (undoped) Hamiltonian.

In order to address the problems of low screening efficiency, easy blocking of screen holes, and short service life of key parts commonly used in vibrating screen equipment, the TRIZ (Theory of the Solution of Inventive Problems) was applied in the present work to design a four-degree-of-freedom (4-DOF; three translational and one rotational movements) chaotic vibrating screen with a chaotic vibration exciter as the main power source and a 3-DOF (three translational movements) parallel kinetic chain as the kinematic constraint mechanism of the outer screen frame. Based on the topological structure theory, a hybrid mechanism with structure [ 4 SOC − C i 1 ∥ R i 2 ∥ R i 3 − + R , i = 1,2,3,4 ] was constructed as the kinematic constraint mechanism of the inner screen box of the chaotic vibrating screen to solve the freedom of motion and POC (position and orientation characteristic) equations of parallel kinematic constraint mechanism of the outer screen frame and hybrid constraint mechanism of the inner screen box. The dynamic simulation of a virtual prototype of the chaotic vibrating screen was carried out in ADAMS software, and MATLAB was used to chaos recognition of the simulation results. It was found that the chaotic exciter moved aperiodically in X-, Y-, and Z-directions when the chaotic exciter motor rotated at uniform speed, and the amplitude, velocity, and acceleration of the outer screen frame of the vibrating screen had characteristics of reciprocating aperiodic and irregular changes. Through the phase trajectories of the eccentric block and inner screen box of the exciter in all directions, it was observed that the motion output of the vibrating screen was a chaotic vibration. Therefore, the present paper can provide an important reference for the design and application of chaotic vibrating screens.

Trevor Wilson (ed.); Myanmar’s long road to national reconciliation (Jean A. Berley) Jennifer Lindsay (ed.); Between tongues; Translation and/of/in performance in Asia (Michael Bodden) Volker Grabowsky; Bevölkerung und Staat in Lan Na; Ein Beitrag zur Bevölkerungsgeschichte Südostasiens Peter Boomgaard) Odille Gannier, Cécile Picquoin (eds); Journal de bord d’Etienne Marchand; Le voyage du Solide autour du monde (1790-1792 (H.J.M. Claessen) Arjan van Helmond, Stani Michiels (eds); Jakarta megalopolis; Horizontal and vertical observations (Ben Derudder) Bert Scova Righini; Een leven in twee vaderlanden; Een biografie van Beb Vuijk (Liesbeth Dolk) Gerrit R. Knaap, J.R. van Diessen, W. Leijnse, M.P.B. Ziellemans; Grote Atlas van de Verenigde Oost-Indische Compagnie/ Comprehensive Atlas of the Dutch United East India Company; Volume II: Java en Madoera/Java and Madura (Amrit Gomperts) Nordin Hussin; Trade and society in the Straits of Melaka; Dutch Melaka and English Penang, 1780-1830 (Hans Hägerdal) Wilco van den Heuvel; Biak; Description of an Austronesian language of Papua (Volker Heeschen) Ann L. Appleton; Acts of integration, expressions of faith; Madness, death and ritual in Melanau ontology (Menno Hekker) Amity A. Doolittle; Property and politics in Sabah, Malaysia; Native struggles over land rights (Monica Janowski) Rajeswary Ampalavanar Brown; The rise of the corporate economy in Southeast Asia (J. Thomas Lindblad) Dwi Noverini Djenar; Semantic, pragmatic and discourse perspectives of preposition use; A study of Indonesian locatives (Don van Minde) Sherri Brainard, Dietlinde Behrens, A grammar of Yakan (Chandra Nuraini) Dietlinde Behrens; Yakan-English dictionary (Chandra Nuraini) Pierre Lemonnier; Le sabbat des lucioles; Sorcellerie, chamanisme et imaginaire cannibale en Nouvelle-Guinée (Anton Ploeg) Edgar Aleo and others; A voice from many rivers; Central Subanen oral and written literature. Translated and annotated by Felicia Brichoux (Nicole Revel) Joos van Vugt, José Eijt, Marjet Derks (eds); Tempo doeloe, tempo sekarang; Het proces van Indonesianisering in Nederlandse orden en congregaties (Karel Steenbrink) Nancy Eberhardt; Imagining the course of life; Self-transformation in a Shan Buddhist community (Nicholas Tapp) J.C. Smelik, C.M. Hogenstijn, W.J.M. Janssen; A.J. Duymaer van Twist; Gouverneur-Generaal van Nederlands-Indiё (1851-1856) (Gerard Termorshuizen) David Steinberg; Turmoil in Burma; Contested legitimacies in Myanmar (Sean Turnell) Carl A. Trocki; Singapore; Wealth, power and the culture of control (Bryan S. Turner) Matthew Isaac Cohen; The Komedie Stamboel; Popular theatre in colonial Indonesia, 1891-1903 (Holger Warnk) Jörgen Hellman; Ritual fasting on West Java (Robert Wessing) Waruno Mahdi; Malay words and Malay things; Lexical souvenirs from an exotic archipelago in German publications before 1700 (Edwin Wieringa) RECENT PUBLICATIONS Russell Jones, C.D. Grijns, J.W. de Vries, M. Siegers (eds); Loan-words in Indonesian and Malay VERHANDELINGEN 249 Peter Carey: The power of prophecy. Prince Dipanagara and the end of an old order in Java, 1785-1855

We demonstrate the existence of a chaotic invariant set of solutions of an idealized model for wind-forced quasi-geostrophic flow over a continental margin with variable topography. The model (originally formulated to investigate mean flow generation by topographic wave drag) has bottom topography that slopes linearly offshore and varies sinusoidally alongshore. The alongshore topographic scales are taken to be short compared to the cross-shelf scale, allowing Hart's (1979) quasi-two-dimensional approximation, and the governing equations reduce to a non-autonomous system of three coupled nonlinear ordinary differential equations. For weak (constant plus time-periodic) forcing and weak friction, we apply a recent extension (Wiggins & Holmes 1987) of the method of Melnikov (1963) to test for the existence of transverse homoclinic orbits in the model. The inviscid unforced equations have two constants of motion, corresponding to energy E and enstrophy M, and reduce to a one-degree-of-freedom Hamiltonian system which, for a range of values of the constant G = E − M, has a pair of homoclinic orbits to a hyperbolic saddle point. Weak forcing and friction cause slow variations in G, but for a range of parameter values one saddle point is shown to persist as a hyperbolic periodic orbit and Melnikov's method may be applied to study the perturbations of the associated homoclinic orbits. In the absence of time-periodic forcing, the hyperbolic periodic orbit reduces to the unstable fixed point that occurs with steady forcing and friction. The method yields analytical expressions for the parameter values for which sets of chaotic solutions exist for sufficiently weak time-dependent forcing and friction. The predictions of the perturbation analysis are verified numerically with computations of Poincaré sections for solutions in the stable and unstable manifolds of the hyperbolic periodic orbit and with computations of solutions for general initial-value problems. In the presence of constant positive wind stress τ0 (equatorward on eastern ocean boundaries), chaotic solutions exist when the ratio of the oscillatory wind stress τ1 to the bottom friction parameter r is above a critical value that depends on τ0/r and the bottom topographic height. The analysis complements a previous study of this model (Samelson & Allen 1987), in which chaotic solutions were observed numerically for weak near-resonant forcing and weak friction.

A low-cost and simple drop-casting method was used to fabricate a carbon nanodot (C-dot)/all-inorganic perovskite (CsPbBr3) nanosheet bilayer heterojunction photodetector on a SiO2/Si substrate. The C-dot/perovskite bilayer heterojunction photodetector shows a high performance with a responsivity (R) of 1.09 A/W, almost five times higher than that of a CsPbBr3-based photodetector (0.21 A/W). In addition, the hybrid photodetector exhibits a fast response speed of 1.318/1.342 µs and a highly stable photocurrent of 6.97 µA at 10 V bias voltage. These figures of merits are comparable with, or much better than, most reported perovskite heterojunction photodetectors. UV–Vis absorption and photoluminescent spectra measurements reveal that the C-dot/perovskite bilayer heterojunction has a band gap similar to the pure perovskite layer, confirming that the absorption and emission in the bilayer heterojunction is dominated by the top layer of the perovskite. Moreover, the emission intensity of the C-dot/perovskite bilayer heterojunction is less than that of the pure perovskite layer, indicating that a significant number of charges were extracted by the C-dot layer. The studied band alignment of the C-dots and perovskites in the dark and under emission reveals that the photodetector has a highly efficient charge separation mechanism at the C-dot/perovskite interface, where the recombination rate between photogenerated electrons and holes is significantly reduced. This highly efficient charge separation mechanism is the main reason behind the enhanced performance of the C-dot/perovskite bilayer heterojunction photodetector.

This issue of The Forum is focused on the military in American politics. It begins by reprinting the classic overview piece from Samuel Huntington. Damon Colletta then unpacks the state of our attention since Huntington, while John Griswold follows the evolution of Huntington’s organizing focus, the National Guard. Irving Louis Horowitz considers many of these same issues in light of the current role of the U.S. in the wider world. Beth Bailey introduces the biggest piece of civilmilitary involvement, in the form of the volunteer (and predecessor conscription) armed forces. Donald Downs raises the aspect of this politics that most closely touches the university, through ROTC. Lilly Goren considers the aspect that often absorbs the greatest number of congressmen, involving base closings. Matthew Holden and Gene Giannotta think about further, fresh ways to study civil-military relations, most especially between Presidents and their generals. And Jason Dempsey and Bradley Cooper introduce the newest program aimed at a crucial aspect of the military in American life, through “Joining Forces”, the military families initiative. Three book reviews close this issue of the journal: Kenneth Mayer on Jason K. Dempsey, Our Army: Soldiers, Politics, and American Civil-Military Relations; David Parker on David R. Mayhew, Partisan Balance: Why Political Parties Don’t Kill the U.S. Constitutional System; and Frances Lee on Gregory Koger, Filibustering: A Political History of Obstruction in the House and Senate.

ABSTRACTThe B2 ⌊ R ⌊ B19′ phase transformations in a Ni-50.7 at.% Ti alloy were investigated under a series of uniaxial tensile stresses. A custom-build X-ray sample holder with hot, cold and stressing stages was used for structure analysis at temperatures up to 140 °C under a variety of tensile stresses (up to 250 MPa). Reorientation and growth of favorably oriented variant domains of R phase and martensite under stress were observed. In the stress-assisted phase transformations, the favorable (020)M and (300)R planes are expected to align preferably parallel to (011)B2 planes, and the unfavorable (111)M and (112)R planes perpendicular to the (011)B2 planes. In addition, the results of semi-quantitative analyses of the relative amounts of parent phase and martensite formed under a specific stress and temperature condition, x=x(σ,T), are presented.

We theoretically study the electromechanical behaviors of a laminated thin-film piezoelectric semiconductor (PS) composite plate with flexural deformation. The nonlinear equations for drift currents of electrons and holes are linearized for a small carrier concentration perturbation. Following the structural theory systemized by R. D. Mindlin, a system of two-dimensional (2D) equations for the laminated thin-film PS plate, including the lowest order coupled extensional and flexural motion, are presented by expanding the displacement, potential, and the incremental concentration of electrons and holes as power series of the plate thickness. Based on the derived 2D equations, the analytical expressions of the electromechanical fields and distribution of electrons in the thin-film PS plate with an n-type ZnO layer subjected to a static bending are presented. The numerical results show that the electromechanical behaviors and piezotronic effects can be effectively controlled by the external applied force and initial concentration of carriers. The derived 2D equations and numerical results in this paper are helpful for developing piezotronic devices.

PIN solar cells were light soaked up to 60 hours. The cell characteristics, the optoelectronic properties and the microstructure parameter (R=I2100/I2100+I2000) as well as the hydrogen content (CH) and density of states (g(Ef)) of the active i-layer were monitored throughout the entire light induced degradation process and compared with the correspondents μτ product (for both carriers) inferred through steady photoconductivity and FST measurements.Data show a strong correlation between the decrease of μτ product for electron and the increase of the fraction of hydrogen bonded on internal surfaces (R increases from 0.1 to 0.4) suggesting structural changes during the light induced defects' formation. For holes, the μτ product remains approximately constant and only dependent on the initial hydrogen content. As g(Ef) increases, μτ presents an asymmetrical decrease showing that electrons are more sensitive to defects' growth than holes.We also observe that the rate of degradation is faster for samples having the lowest defect densities, R and CH, showing that the amount of degradation is not a simple function of the photon exposure (Gt product) but also depends on the material microstructure.

AbstractThe effect of magnetic fields to 15T on the electrical resistance (R) of Bi-Sr-Ca-Cu-O superconductors has been measured at precise temperatures during the transition to the superconducting state. The results show that the temperature at which the externally-applied magnetic field causes a divergence of resistance (R) as a function of inverse temperature is approximately at the same temperature where the positive Hall coefficient begins its steep descent to zero. At slightly higher temperature the Hall coefficient shows a singularity peak akin to a delta function. Internal electric field calculations show that the structure of the superconducting oxides, having more than a single building block polyhedron, gives rise to strong electrostatic fields in the unit cell which in turn causes charge separation or polarization. The charge separation is in accord with the importance of high oxidation states of the multivalence cations and suggests the use of high oxygen overpressure during processing. The magnitude of Tc scales closely with the number of bound holes (associated with the charge transfer excitations) per unit cell. Extensive computer calculations using this model indicate attractive pairing of electrons at inter-electron separations of about 10–15A.

ABSTRACTShubnikov-de Haas and Hall measurements have been performed on singly delta doped GaAs(Si) structures, grown by molecular beam epitaxy, enabling us to study the effects of illumination and temperature upon bulk and individual subband, mobilities and carrier concentrations. In a highly doped sample, where the peak 3D electron concentration approaches 2×1019cm−3, we have observed novel changes in subband transport characteristics, not observed in the lower doped samples, which we attribute to the presence of DX centre phenomena. This paper explains the variations in individual subband transport properties due to a possible shift of the electronic wave functions contained in the potential well. This shift occurs due to a recombination-autoionization(R-A) process involving filled DX centres and free holes upon sample illumination at low temperatures.

ABSTRACTIn this paper we describe a new method for the determination of the carrier lifetime (r) and the carrier Mobilities (μn, μp) in semiconductors. This technique utilizes a moving intensity grating that is generated by superposition of frequency shifted laser beams for the illumination of the sample. The Material parameters are extracted from the short circuit current in the sample induced by the moving grating as a function of it's velocity (vgr). We solve the continuity equations and Poisson's equation in the small signal approach for the modulated electron and hole densities and show how these densities result in an electric field that in turn acts on the electrons and holes in order to yield a short circuit current density jsc. From a fit of this expression for jsc to experimental data we determine μn, μp and τ.

ABSTRACTSurface diffusion and crystal growth processes have been studied in the Stranski-Krastanov growth system Ag/Si(111), using several UHV-SEM techniques. By depositing Ag at various rates 0.2 ≤ R ≤ 1.4 ML-min−1 through a mask of holes, surface diffusion of Ag over the intermediate layer has been observed, in competition with re-evaporation at high, and nucleation at low substrate temperatures, in the range 620 < T < 850K. The Si(111) √3Ag intermediate layer has been visualized using biassed secondary electron imaging. The surface diffusion and nucleation processes observed have been analyzed in terms of kinetic models. Comparison with experiment yields values for the adsorption, diffusion and binding (Ea′ Ed and Eb) energies of Ag on the intermediate layer. These values are approximately Ea = 2.45 ± 0.1 eV, Ed 0.35 ± 0.05 eV and Eb = 0.10 ± 0.03 eV, where the uncertainties result at least as much from lack of knowledge of pre-exponential factors in the models as in the accuracy of the experiments.

ABSTRACTA study of the complex dielectric properties at microwave and millimeterwave frequencies on several polyanilines was performed. The polymers investigated were based on emeraldine salts. The chemically synthesized emeraldine base was protonated with acids of various pH levels. Aqueous HCI (pH range 0.12 to 1.07) and Tosylic (pH range 0.22 to 1.13) were used. Complex permittivities of the emeraldine base and salts were determined at X-band and R-band using waveguide measurements. Characterization techniques were developed to reduce the measurement error. This included the electrical determination of the sample holder length and sample position. The real component of the dielectric constant was found to vary from 4 to 107 at Xband and from 3.8 to 926 at R-band. The dielectric loss spanned 3 orders of magnitude at X-band and 4 orders of magnitude at Rband. The frequency dependence was relatively level within each band with a slight decrease in each permittivity component with increasing frequency. The DC conductivity ranged from 10−4 S/cm to 10−1 S/cm for the emeraldine salts. The time dependence of the complex permittivity and DC conductivity was examined.

This paper presents an experimental investigation on the effect of interference-fit on the bearing strength and fatigue life of pin-loaded plain-woven and cross ply carbon fiber-reinforced plastic laminate (CFRP). Stainless steel pins are installed to five different sized holes on the CFRP specimens to achieve transition-fit and four interference-fits (0.2%, 0.4%, 0.6%, and 1.0%). The quasi-static and fatigue (R = 0.1) properties of the pin-loaded CFRP are then compared to each other. From the experimental results, it is demonstrated that the interference-fit can improve the joint stiffness per unit bearing area, or the joint stiffness, under both the static and dynamic bearing load conditions. The ultimate bearing strength, fatigue life, and joint stiffness of interference-fit samples are higher than those of the transition-fit samples and they are maximized at an interference-fit percentage of 0.4%. Regardless of interference-fit percentage, the fatigue life of a pin-loaded CFRP specimen tends to be proportional to its joint stiffness in the beginning of a fatigue test. During fatigue testing, the joint stiffness of pin-loaded CFRP gradually decreases to the range of 18.8 GPa/mm to 18.6 GPa/mm when bearing failure occurs. The increased joint stiffness by interference-fit delays CFRP hole damage growth by reducing pin displacement under fatigue cycles.

Abstract Emphasis on lean premixed combustion in modern low NOX combustion chambers limits the air available for cooling the combustion liner. Hence, the development of optimized liner cooling designs is imperative for effective usage of available coolant. An effective way to cool a gas turbine combustor liner is through effusion cooling. Effusion cooling (also known as full-coverage film cooling) involves uniformly spaced holes distributed throughout the liner’s curved surface area. This study presents findings from an experimental study on the characterization of the overall cooling effectiveness of an effusion-cooled liner wall, which was representative of a can combustor under heated flow (non-reacting) and lean-combustion (reacting) conditions. The model can combustor was equipped with an industrial swirler, which subjected the liner walls to engine representative flow and combustion conditions. In this study, two different effusion cooling liners with an inline and staggered arrangement of effusion holes have been studied. Non-dimensionalized streamwise hole-to-hole spacing (z/d) and spanwise hole-to-hole spacing (r/d) of 10 were used for both the effusion liners. These configurations were tested for five different blowing ratios ranging from 0.7 to 4.0 under both reacting and non-reacting conditions. The experiments were carried out at a constant main flow Reynolds number (based on combustor diameter) of 12,500. The non-reacting experiments were carried out by heating the mainstream air, and the reacting experiments were carried out under flame conditions at a total equivalence ratio of 0.65. Infrared thermography (IRT) was used to measure the liner outer surface temperature, and detailed overall effectiveness values were determined under steady-state conditions. It was observed that overall cooling effectiveness trends were different under reacting and non-reacting conditions. The cooling effectiveness for the non-reacting experiments exhibited a decreasing trend, and no consistent location of minimum cooling effectiveness was observed for the range of blowing ratios investigated in this study. For the reacting cases, the cooling effectiveness first follows a decreasing trend, reaches a distinct minimum, and then increases till the end of the combustor. Under non-reacting conditions, the staggered configuration was 9–25% more effective than inline configuration, and under reacting conditions, the staggered configuration was 4–8% more effective than inline configuration. From this study, it is clear that the coolant flame interaction for the reacting experiments impacted the liner cooling effectiveness and led to different overall cooling effectiveness distribution on the liner when compared with the non-reacting experiments.

Devido a evolução dos sistemas cerâmicos, atualmente, são permitidas inúmeras associações de materiais restauradores. Entretanto, mimetizar as características visuais das próteses livres de metal com próteses metalocerâmica permanece um desafio. Assim, o objetivo deste trabalho foi relatar o caso clínico de substituição de próteses desadaptadas, homogeneizando próteses parciais fixas livres de metal e metalocerâmicas dento e implantossuportadas, após cirurgia periodontal. O paciente de 55 anos, gênero masculino, compareceu à Clínica de Prótese Parcial Fixa, da Faculdade de Odontologia de Araçatuba – FOA/UNESP em 2017 queixando-se dos seus dentes anteriores estarem “feios” e com a “raiz aparecendo”. No exame clínico foi constatada recessão gengival nos elementos 11 e 13, os quais continham uma prótese parcial fixa de três elementos metalocerâmicas desadaptada, prótese sobre implante nos elementos 21 e 22, que apresentavam-se desadaptadas e com estética desfavorável. No exame radiográfico pôde-se observar a presença de um núcleo metálico fundido nos elementos 11 e 13. Foi proposto, então, a confecção de coroas totais livres de metal nos elementos anteriores superiores (13, 12, 11, 21 e 23) e coroa metalocerâmica para o elemento 22. Para isso, foi realizado enceramento diagnóstico inicial e, após o consentimento do paciente, foi efetuada a remoção das próteses antigas. Com a remoção, visualizamos uma depressão na vestibular do rebordo na área do 12 (ausente), solucionado com um enxerto gengival subepitelial. Após a realização dos preparos dentários e moldagem com silicone de adição as peças foram confeccionadas com sistema e.max Ceram (Ivoclar Vivadent). Após a prova estética e ajustes oclusais iniciais, as peças foram preparadas para cimentação resinosa com o sistema Variolink® N (Ivoclar Vivadent). O cimento transparente foi selecionado previamente por meio de provas com o kit Try-In. Conclui-se que, apesar da disparidade dos materiais, é possível mimetizá-los e oferecer resultados reabilitadores suficientemente estéticos e satisfatórios.Descritores: Implantação Dentária; Estética Dentária; Materiais Dentários.ReferênciasCardenas AFM, Mora CAP, Siqueira FSF, Parreiras SO, Gomes JC. Restabelecimento estético de um sorriso envelhecido: Caso clínico. Revista APCD de Estética. 2015;3(1):42-52.Strasding M, Fehmer V, Pjetursson BE, Sailer I. Extending the service life of existing dental restorations with esthetic and functional limitations. J Prosthet Dent. 2018;119(6):893-96.Koidou VP, Rosenstiel SF, Rashid RG. Celebrity smile esthetics assessment: Smile angulation. J Prosthet Dent, 2017;117(5):636-41.Levin, EI. Dental esthetics and the golden proportion. J Prosthet Dent. 1978;40(3):244-52.Flores-Mir C, Silva E, Barriga MI, Lagravere MO, Major PW. Lay person's perception of smile aesthetics in dental and facial views. J Orthod. 2004;31(3):204-9.Cotrim, ER, Vasconcelos Júnior, ÁV, Haddad, ACSS, Reis SAB. Perception of adults' smile esthetics among orthodontists, clinicians and laypeople. Dental Press J. Orthod. 2015;20(1):40-4.Chaudhari A, Bagga DK, Agrawal P, Kalra H, Sirohi D. An assessment of the self-satisfying smile among different professionals. J Int Oral Health. 2018;10(3):111-14.Papaspyridakos P, Chen CJ, Singh M, Weber HP, Gallucci GO. Success criteria in implant dentistry: a systematic review. J Dent Res. 2012;91(3):242-48.Bonfante EA, Suzuki M, Lorenzoni FC, Sena LA, Hirata R, Bonfante G et al. Probability of survival of implant-supported metal ceramic and CAD/CAM resin nanoceramic crowns. Dent Mater J. 2015;31(8):e168-77.Egilmez F, Ergun G, Cekic-Nagas I, Bozkaya S. Implant-supported hybrid prosthesis: conventional treatment method for borderline cases. Eur J Dent. 2015;9(3):442-48.Schweitzer DM, Goldstein GR, Ricci JL, Silva NR, Hittelman EL. Comparison of bond strength of a pressed ceramic fused to metal versus feldspathic porcelain fused to metal. J Prosthodont. 2005;14(4):239-47.Venkatachalam B, Goldstein GR, Pines MS, Hittelman EL. Ceramic pressed to metal versus feldspathic porcelain fused to metal: a comparative study of bond strength. Int J Prosthodont. 2009;22(1):94-100.Holden JE, Goldstein GR, Hittelman EL, Clark EA. Comparison of the marginal fit of pressable ceramic to metal ceramic restorations. J Prosthodont. 2009;18: 645-48.Sinhori BS, de Andrada MAC, Lopes GC, Monteiro Junior S, Baratieri LN. Influence of Teeth Preparation Finishing on the Adaptation of Lithium Disilicate Crowns. Int J Biomater. 2017; ID 2078526.Hoppen LRC, Garbin CA, Rigo L, Schuh C, FederizzI L. Comparação estética entre coroas confeccionadas com os sistemas Cubo e metalocerâmico. Rev Sul-Bras Odontol. 2010;7(2):146-53.Mazur CE, Machado CT, Malheiros Pfau VJ, Augusto Pfau, E. Planejamento multidisciplinar na reconstrução do sorriso. JCDR. 2017; 14(2):62-70.Zuhr O, Bäumer D, Hürzeler M The addition of soft tissue replacement grafts in plastic periodontal and implant surgery: critical elements in design and execution. J Clin Periodontol. 2014;41(Suppl15):S123-42.Consolaro A. Saucerização: um mecanismo natural de adaptação peri-implantar cervical. Dental Press Implantol, 2014;8(4):8-15.Nealon FH. Acrylic restorations by the operative nonpressure procedure. J Prosthet Dent. 1952;2(4):513-27.Newman MG, Takei H, Klokkevold PR, Carranza FA. Periodontia clínica. Rio de Janeiro: Elsevier Brasil; 2007. p.926-35.Raetzke PB. Covering localized areas of root exposure employing the “envelope” technique. J Periodontol. 1985;56(7):397-402.Hannah R, Ramani P, Sherlin HJ, Ranjith G, Ramasubramanian A, Jayaraj G et al. Awareness about the use, ethics and scope of dental photography among undergraduate dental students dentist behind the lens. RJPT. 2018; 11(3):1012-16.Alberton SB, Alberton V, Carvalho RV. Providing a harmonious smile with laminate veneers for a patient with peg-shaped lateral incisors. J Conserv Dent. 2017;20(3):210-13.Vervaeke S, Matthys C, Nassar R, Christiaens V, Cosyn J, De Bruyn H. Adapting the vertical position of implants with a conical connection in relation to soft tissue thickness prevents early implant surface exposure: A 2‐year prospective intra‐subject comparison. J Clin Periodontol. 2018;45(5):605-12.Anusavice K, Shen C, Rawls HR. Dental casting and soldering alloys. In: Anusavice KJ, Phillips’ Science of Dental Material. St. Louis: Elsevier; 2003. p.563–620.Arinc H. Implant-supported fixed partial prostheses with different prosthetic materials: a three-dimensional finite element stress analysis. Implant Dent. 2018;27(3):303-10.Monnet-Corti V, Antezack A, Pignoly M. Comment parfaire l’esthétique du sourire: toujours en rose! Orthod Fr. 2018;89(1):71-80.Tonetti MS, Cortellini P, Graziani F, Cairo F, Lang NP, Abundo R et al. Immediate versus delayed implant placement after anterior single tooth extraction: the timing randomized controlled clinical trial. J Clin Periodontol. 2017;44(2):215-24.Pradeep AR, Karthikeyan BV. Peri-implant papilla reconstruction: Realities and limitations. J Periodontol. 2006; 77(3):534-44.Nariman RH, Pai UY, Soumya MK, Hegde R. A clinical assessment of the volume of interproximal papilla after definitive prosthesis around immediate and delayed loading implants placed in the maxillary esthetic zone: An in vivo study. J Indian Prosthodont Soc. 2018;18(2):168-73.Neves FDD, Silveira-Júnior CD, Coró V, Silva-Neto JP, Simamoto-Júnior PC, Prado CJD. Gingival conditioning in an implant-supported prosthesis: a clinical report. J Oral Implantol. 2013;39(4):483-85.

07–198Agulló, G. (U Jaén, Spain; gluque@jaen.es), Overcoming age-related differences. ELT Journal (Oxford University Press) 60.4 (2006), 365–373.07–199Ammar, Ahlem (U de Montréal, Canada; ahlem.ammar@umontreal.ca) & Nina Spada, One size fits all? Recasts, prompts, and L2 learning. Studies in Second Language Acquisition (Cambridge University Press) 28.4 (2006), 543–574.07–200Bartram, Brendan (U Wolverhampton, UK), An examination of perceptions of parental influence on attitudes to language learning. Educational Research (Routledge/Taylor & Francis) 48.2 (2006), 211–221.07–201Bordag, Denisa (U Leipzig, Germany), Andreas Opitz & Thomas Pechmann, Gender processing in first and second languages: The role of noun termination. Journal of Experimental Psychology: Learning, Memory, and Cognition (American Psychological Association) 32.5 (2006), 1090–1101.07–202Brown, Jill (Monash U, Australia), Jenny Miller & Jane Mitchell, Interrupted schooling and the acquisition of literacy: Experiences of Sudanese refugees in Victorian secondary schools. Australian Journal of Language and Literacy (Australian Literacy Educators' Association) 29.2 (2006), 150–162.07–203Castagnaro, P. (Temple U, Japan), Audiolingual method and behaviorism: From misunderstanding to myth. Applied Linguistics (Oxford University Press) 27.3 (2006), 519–526.07–204Chang, Anna Ching-Shyang & John Read (Hsing-Wu College, Taiwan), The effects of listening support on the listening performance of EFL learners. TESOL Quarterly 40.2 (2006), 375–397.07–205Cieślicka, Anna (Adam Mickiewicz U, Poznań, Poland), Literal salience in on-line processing of idiomatic expressions by second language learners. Second Language Research (Sage) 22.2 (2006), 115–144.07–206Cots J. (U Lleida, Spain; jmcots@dal.udl.es), Teaching ‘with an attitude’: Critical Discourse Analysis in EFL teaching. ELT Journal (Oxford University Press) 60.4 (2006), 336–345.07–207Curdt-Christiansen, Xiao Lan (Nanyang Technological U, Singapore), Teaching and learning Chinese: Heritage language classroom discourse in Montreal Scots in contemporary social and educational context. Language, Culture and Curriculum (Multilingual Matters) 19.2 (2006), 189–207.07–208Ellis, Nick C. (U Michigan, USA), Selective attention and transfer phenomena in L2 acquisition: Contingency, cue competition, salience, interference, overshadowing, blocking, and perceptual learning. Applied Linguistics (Oxford University Press) 27.2 (2006), 164–194.07–209Ellis, Rod (U Auckland, New Zealand; r.ellis@auckland.ac.nz), Modelling learning difficulty and second language proficiency: The differential contributions of implicit and explicit knowledge. Applied Linguistics (Oxford University Press) 27.3 (2006), 431–463.07–210Ellis, Rod (U Auckland, New Zealand; r.ellis@auckland.ac.nz) & Younghee Sheen, Reexamining the role of recasts in second language acquisition. Studies in Second Language Acquisition (Cambridge University Press) 28.4 (2006), 575–600.07–211Erlam, R. (U Auckland, New Zealand), Elicited imitation as a measure of L2 implicit knowledge: An empirical validation study. Applied Linguistics (Oxford University Press) 27.3 (2006), 464–491.07–212Farrell, Thomas S. C. (Brock U, Canada; tfarrell@brocku.ca) & Christophe Mallard, The use of reception strategies by learners of French as a foreign language. The Modern Language Journal (Blackwell) 90.3 (2006), 338–352.07–213Folse, Keith S. (U Central Florida, USA), The effect of type of written exercise on L2 vocabulary retention. TESOL Quarterly 40.2 (2006), 273–293.07–214Goad, Heather (McGill U, Montreal, Canada) & Lydia White, Ultimate attainment in interlanguage grammars: A prosodic approach. Second Language Research (Sage) 22.3 (2006), 243–268.07–215Gullberg, Marianne (Max Planck Institute for Psycholinguistics, Germany; marianne.gullberg@mpi.nl), Some reasons for studying gesture and second language acquisition (Hommage à Adam Kendon). International Review of Applied Linguistics in Language Teaching (Walter de Gruyter) 44.2 (2006), 103–124.07–216Hall, Joan Kelly, An Cheng & Matthew Carlson (Pennsylvania State U, USA), Reconceptualizing multicompetence as a theory of language knowledge. Applied Linguistics (Oxford University Press) 27.2 (2006), 220–204.07–217Harada, Tetsuo (Waseda U, Japan; tharada@waseda.jp), The acquisition of single and geminate stops by English-speaking children in a Japanese immersion program. Studies in Second Language Acquisition (Cambridge University Press) 28.4 (2006), 601–632.07–218Hawkey, Roger (U Bristol, UK; roger@hawkey58.freeserve.co.uk), Teacher and learner perceptions of language learning activity. ELT Journal (Oxford University Press) 60.3 (2006), 242–252.07–219Hawkins, Roger (U Essex, UK) & Hajime Hattori, Interpretation of English multiplewh-questions by Japanese speakers: A missing uninterpretable feature account. Second Language Research (Sage) 22.3 (2006), 269–301.07–220Hayes-Harb, Rachel (U Utah, USA), Native speakers of Arabic and ESL texts: Evidence for the transfer of written word identification processes. TESOL Quarterly 40.2 (2006), 321–339.07–221Hirvela, Alan (Ohio State U, USA; hirvela.1@osu.edu), Computer-mediated communication in ESL teacher education. ELT Journal (Oxford University Press) 60.3 (2006), 233–241.07–222Hong-Nam, Kyungsim (U North Texas, USA; ksh0030@unt.edu) & Alexandra Leavell, Language learning strategy use of ESL students in an intensive English learning context. System (Elsevier) 34.3 (2006), 399–415.07–223Hopp, Holger (U Groningen, the Netherlands), Syntactic features and reanalysis in near-native processing. Second Language Research (Sage) 22.3 (2006), 369–397.07–224Jungheim, Nicholas (Waseda U, Japan; jungheim@waseda.jp), Learner and native speaker perspectives on a culturally-specific Japanese refusal. International Review of Applied Linguistics in Language Teaching (Walter de Gruyter) 44.2 (2006), 125–143.07–225Kim, Youngkyu (Ewha Womens U, Korea), Effects of input elaboration on vocabulary acquisition through reading by Korean learners of English as a Foreign Language. TESOL Quarterly 40.2 (2006), 341–373.07–226Lai, Chun & Yong Zhao (Michigan State U, USA; laichun1@msu.edu), Noticing and text-based chat. Language Learning & Technology (University of Hawaii) 10.3 (2006), 102–120.07–227Lee, Siok H. & James Muncie (Simon Fraser U, Canada), From receptive to productive: Improving ESL learners' use of vocabulary in a postreading composition task. TESOL Quarterly 40.2 (2006), 295–320.07–228Lee, Y. (DePaul U, USA; ylee19@depaul.edu), Towards respecification of communicative competence: Condition of L2 Instruction or its objective?Applied Linguistics (Oxford University Press) 27.3 (2006), 349–376.07–229Lew, Robert (Adam Mickiewicz U, Poznań, Poland; rlew@amu.edu.pl) & Anna Dziemianko, A new type of folk-inspired definition in English monolingual learners' dictionaries and its usefulness for conveying syntactic information. International Journal of Lexicography (Oxford University Press) 19.3 (2006), 225–242.07–230Liaw, Meei-ling (National Taichung U, Taiwan; meeilingliaw@gmail.com), E-learning and the development of intercultural competence. Language Learning & Technology (University of Hawaii) 10.3 (2006), 49–64.07–231Lieberman, Moti (American U, USA; aoshima@american.edu), Sachiko Aoshima & Colin Phillips, Nativelike biases in generation ofwh-questions by nonnative speakers of Japanese. Studies in Second Language Acquisition (Cambridge University Press) 28.3 (2006), 423–448.07–232Lin, Huifen (Kun Shan U, China; huifen5612@yahoo.com.tw) & Tsuiping Chen, Decreasing cognitive load for novice EFL learners: Effects of question and descriptive advance organisers in facilitating EFL learners' comprehension of an animation-based content lesson. System (Elsevier) 34.3 (2006), 416–431.07–233Liu, Meihua (Tsinghua U, China; ellenlmh@yahoo.com), Anxiety in Chinese EFL students at different proficiency levels. System (Elsevier) 34.3 (2006), 301–316.07–234Lotz, Anja (Philipps-Universität Marburg, Germany) & Annette Kinder, Transfer in artificial grammar learning: The role of repetition information. Journal of Experimental Psychology: Learning, Memory, and Cognition (American Psychological Association) 32.4 (2006), 707–715.07–235Lozano, Cristobal (Universidad Autónoma de Madrid, Spain), Focus and split-intransitivity: The acquisition of word order alternations in non-native Spanish. Second Language Research (Sage) 22.2 (2006), 145–187.07–236Macaro, Ernesto (U Oxford; ernesto.macaro@edstud.ox.ac.uk), Strategies for language learning and for language use: Revising the theoretical framework. The Modern Language Journal (Blackwell) 90.3 (2006), 320–337.07–237McCafferty, Steven (U Nevada, USA; mccaffes@unlv.nevada.edu), Gesture and the materialization of second language prosody. International Review of Applied Linguistics in Language Teaching (Walter de Gruyter) 44.2 (2006), 197–209.07–238Nassaji, Hossein (U Victoria, Canada; nassaji@uvic.ca), The relationship between depth of vocabulary knowledge and L2 learners' lexical inferencing strategy use and success. The Modern Language Journal (Blackwell) 90.3 (2006), 387–401.07–239Palfreyman, David (Zayed U, United Arab Emirates; David.Palfreyman@zu.ac.ae), Social context and resources for language learning. System (Elsevier) 34.3 (2006), 352–370.07–240Qing Ma (U Louvain, Belgium) & Peter Kelly, Computer assisted vocabulary learning: Design and evaluation. Computer Assisted Language Learning (Routledge/Taylor & Francis) 19.1 (2006), 15–45.07–241Reinders, Hayo & Marilyn Lewis (U Auckland, NZ), An evaluative checklist for self-access materials. ELT Journal (Oxford University Press) 60.3 (2006), 272–278.07–242Rule, Sarah (U Southampton, UK) & Emma Marsden, The acquisition of functional categories in early French second language grammars: The use of finite and non-finite verbs in negative contexts. Second Language Research (Sage) 22.2 (2006), 188–218.07–243Shin, Dong-Shin (U Massachusetts, Amherst, USA; dongshin@educ.umass.edu), ESL students' computer-mediated communication practices: Context configuration. Language Learning & Technology (University of Hawaii) 10.3 (2006), 65–84.07–244Sime, Daniela (U Strathclyde, UK; daniela.sime@strath.ac.uk), What do learners make of teachers' gestures in the language classroom?International Review of Applied Linguistics in Language Teaching (Walter de Gruyter) 44.2 (2006), 211–230.07–245Slabakova, Roumyana (U Iowa, USA), Is there a critical period for semantics?Second Language Research (Sage) 22.3 (2006), 302–338.07–246Slevc, L. Robert (U California, San Diego, USA; slevc@psy.ucsd.edu) & Akira Miyake, Individual differences in second-language proficiency: Does musical ability matter?. Psychological Science (Blackwell) 17.8 (2006), 675–681.07–247Sorace, Antonella (U Edinburgh, UK) & Francesca Filiaci, Anaphora resolution in near-native speakers of Italian. Second Language Research (Sage) 22.3 (2006), 339–368.07–248Stam, Gale (National-Louis U, USA; gstam@nl.edu), Thinking for speaking about motion: L1 and L2 speech and gesture. International Review of Applied Linguistics in Language Teaching (Walter de Gruyter) 44.2 (2006), 145–171.07–249Subrahmanyam, Kaveri (California State U, Los Angeles, USA) & Hsin-Hua Nancy Chen, A crosslinguistic study of children's noun learning: The case of object and substance words. First Language (Sage) 26.2 (2006), 141–160.07–250Sunderman, Gretchen (Florida State U, USA; gsunderm@fsu.edu) & Judith F. Kroll, First language activation during second language lexical processing: An investigation of lexical form, meaning, and grammatical class. Studies in Second Language Acquisition (Cambridge University Press) 28.3 (2006), 387–422.07–251ten Hacken, Pius (Swansea U, UK; p.ten-hacken@swansea.ac.uk), Andrea Abel & Judith Knapp, Word formation in an electronic learners' dictionary: ELDIT. International Journal of Lexicography (Oxford University Press) 19.3 (2006), 243–256.07–252Thi Hoang Oanh, Duong (Hue U, Vietnam; dthoangoahn@gmail.com) & Nguyen Thu Hien, Memorization and EFL students' strategies at university level in Vietnam. TESL-EJ (http://www.tesl-ej.org) 10.2 (2006), 17 pp.07–253Waters, A. (U Lancaster, UK; A.Waters@lancaster.ac.uk), Thinking and language learning. ELT Journal (Oxford University Press) 60.4 (2006), 319–327.07–254Williams, Peter (U East London, UK; pete.williams@rixcentre.org), Developing methods to evaluate web usability with people with learning difficulties. British Journal of Special Education (Blackwell) 33.4 (2006), 173–179.07–255Woodrow, Lindy J. (U Sydney, Australia; l.woodrow@edfac.usyd.edu.au), A model of adaptive language learning. The Modern Language Journal (Blackwell) 90.3 (2006), 297–319.07–256Yoshii, Makoto (Prefectural U Kumamoto, Japan; yoshii@pu-kumamoto.ac.jp), L1 and L2 glosses: Their effects on incidental vocabulary learning. Language Learning & Technology (University of Hawaii) 10.3 (2006), 85–101.07–257Yoshioka, Keiko (Leiden U, the Netherlands; k.yoshioka@let.leidenuniv.nl) & Eric Kellerman, Gestural introduction of ground reference in L2 narrative discourse. International Review of Applied Linguistics in Language Teaching (Walter de Gruyter) 44.2 (2006), 173–195.07–258Zyzik, Eve (Michigan State U, USA; zyzik@msu.edu), Transitivity alternations and sequence learning: Insights from L2 Spanish production data. Studies in Second Language Acquisition (Cambridge University Press) 28.3 (2006), 449–485.