W. Shockley

In order to find an upper theoretical limit for the efficiency of p‐n junction solar energy converters, a limiting efficiency, called the detailed balance limit of efficiency, has been calculated for an ideal case in which the only recombination mechanism of hole‐electron pairs is radiative as required by the principle of detailed balance. The efficiency is also calculated for the case in which radiative recombination is only a fixed fraction fc of the total recombination, the rest being nonradiative. Efficiencies at the matched loads have been calculated with band gap and fc as parameters, the sun and cell being assumed to be blackbodies with temperatures of 6000°K and 300°K, respectively. The maximum efficiency is found to be 30% for an energy gap of 1.1 ev and fc = 1. Actual junctions do not obey the predicted current‐voltage relationship, and reasons for the difference and its relevance to efficiency are discussed.

The statistics of the recombination of holes and electrons in semiconductors is analyzed on the basis of a model in which the recombination occurs through the mechanism of trapping. A trap is assumed to have an energy level in the energy gap so that its charge may have either of two values differing by one electronic charge. The dependence of lifetime of injected carriers upon initial conductivity and upon injected carrier density is discussed.

The method of effective mass, extended to apply to gradual shifts in energy bands resulting from deformations of the crystal lattice, is used to estimate the interaction between electrons of thermal energy and the acoustical modes of vibration. The mobilities of electrons and holes are thus related to the shifts of the conduction and valence-bond (filled) bands, respectively, associated with dilations of longitudinal waves. The theory is checked by comparison of the sum of the shifts of the conduction and valence-bond bands, as derived from the mobilities, with the shift of the energy gap with dilation. The latter is obtained independently for silicon, germanium and tellurium from one or more of the following: (1) the change in intrinsic conductivity with pressure, (2) the change in resistance of an $n\ensuremath{-}p$ junction with pressure, and (3) the variation of intrinsic concentration with temperature and the thermal expansion coefficient. Higher mobilities of electrons and holes in germanium as compared with silicon are correlated with a smaller shift of energy gap with dilation.

For certain p-n junctions, it has been observed that the measured current-voltage characteristics deviate from the ideal case of the diffusion model. It is the purpose of this paper to show that the current due to generation and recombination of carriers from generation-recombination centers in the space charge region of a p-n junction accounts for the observed characteristics. This phenomenon dominates in semiconductors with large energy gap, low lifetimes, and low resistivity. This model not only accounts for the nonsaturable reverse current, but also predicts an apparent exp (qV/nkT) dependence of the forward current in a p-n junction. The relative importance of the diffusion current outside the space charge layer and the recombination current inside the space charge layer also explains the increase of the emitter efficiency of silicon transistors with emitter current. A correlation of the theory with experiment indicates that the energy level of the centers is a few kT from the intrinsic Fermi level.

The energies and motions of grain boundaries between two crystallites are investigated theoretically using the dislocation model of grain boundaries. Quantitative predictions made for simple boundaries for cases in which the plane of the boundary contains the axis of relative rotation of the grains appear to agree with available experimental data. The quantitative expression for energy per unit area for small angles is approximately $[\frac{\mathrm{Ga}}{4\ensuremath{\pi}(1\ensuremath{-}\ensuremath{\sigma})}]\ensuremath{\theta}[A\ensuremath{-}\mathrm{ln}\ensuremath{\theta}]$ where $G$ is the rigidity modulus, $a$ the lattice constant, $\ensuremath{\sigma}$ Poisson's ratio, $\ensuremath{\theta}$ the relative rotation and $A$ approximately 0.23. Grain boundaries of the form considered may permit intercrystalline slip and may act as stress raisers for the generation of dislocations.

In a single crystal of semiconductor the impurity concentration may vary from p-type to n-type producing a mechanically continuous rectifying junction. The theory of potential distribution and rectification for p-n junctions is developed with emphasis on germanium. The currents across the junction are carried by the diffusion of holes in n-type material and electrons in p-type material, resulting in an admittance for a simple case varying as (1 + iωτ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</inf> ) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/2</sup> where τ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</inf> is the lifetime of a hole in the n-region. Contact potentials across p-n junctions, carrying no current, may develop when hole or electron injection occurs. The principles and theory of a p-n-p transistor are described.

A set of electronic polarizabilities has been obtained from a least-squares fit of experimental refraction data using simple additivity and a Lorentz factor of $\frac{4\ensuremath{\pi}}{3}$. Except for the fluorides, the electronic polarizability values of the alkali-halide crystals calculated from this set agree with the experimental data within 3 percent. Similar least-squares fits were attempted with various values of the Lorentz factor, the best fit being obtained for $\frac{4\ensuremath{\pi}}{3}$. On the basis of $\frac{4\ensuremath{\pi}}{3}$, the additivity assumption and the alkali-halide set, polarizabilities have been obtained for other ions. The best values for the sodium $D$ line in ${\mathrm{A}}^{3}$ are ${\mathrm{Li}}^{+}$ 0.03, ${\mathrm{Na}}^{+}$ 0.41, ${\mathrm{K}}^{+}$ 1.33, ${\mathrm{Rb}}^{+}$ 1.98, ${\mathrm{Cs}}^{+}$ 3.34, ${\mathrm{F}}^{\ensuremath{-}}$ 0.64, ${\mathrm{Cl}}^{\ensuremath{-}}$ 2.96, ${\mathrm{Br}}^{\ensuremath{-}}$ 4.16, ${\mathrm{I}}^{\ensuremath{-}}$ 6.43, ${\mathrm{Ca}}^{++}$ 1.1, ${\mathrm{Sr}}^{++}$ 1.6, ${\mathrm{Ba}}^{++}$ 2.5, ${\mathrm{O}}^{\ensuremath{-}\ensuremath{-}}$ 0.5-3.2, ${\mathrm{S}}^{\ensuremath{-}\ensuremath{-}}$ 4.8-5.9, ${\mathrm{Se}}^{\ensuremath{-}\ensuremath{-}}$ 6.0-7.5, ${\mathrm{Te}}^{\ensuremath{-}\ensuremath{-}}$ 8.3-10.2, ${\mathrm{Ag}}^{+}$ 2.4, ${\mathrm{Cu}}^{+}$ 1.6, ${\mathrm{Cu}}^{++}$ 0.2, ${\mathrm{Zn}}^{++}$ 0.8, ${\mathrm{Cd}}^{++}$ 1.8, ${\mathrm{Ge}}^{4+}$ 1, ${\mathrm{Sn}}^{4+}$ 3.4, ${\mathrm{Pb}}^{++}$ 4.9. Values represented by a spread indicate ions that cannot be treated additively.

The wave functions and energy levels associated with a finite one-dimensional periodic potential field are investigated. In a plot of the energy spectrum versus interatomic distance the surface levels appear only at lattice constants so small that the boundary curves for the allowed energy bands have crossed. The levels appear in the "forbidden" region between allowed bands in pairs one coming from each of the adjoining bands. In three dimensions these surface levels give rise to surface bands. The surface bands probably exist and are half-filled for diamond. They exist for all metals and are entirely unoccupied only for the monovalent metals.

General expressions are derived for the currents which flow in the external circuit connecting a system of conductors when a point charge is moving among the conductors. The results are applied to obtain explicit expressions for several cases of practical interest.

The spectral distribution of the rate of photon generation for the photon-radiative recombination of electrons and holes in germanium is determined from known optical properties by application of the principle of detailed balance. Quantities characterizing the process are evaluated: The thermal equilibrium recombination rate at 300\ifmmode^\circ\else\textdegree\fi{}K is 1.57\ifmmode\times\else\texttimes\fi{}${10}^{13}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ ${\mathrm{sec}}^{\ensuremath{-}1}$, which corresponds to a recombination cross section of 2.9\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}21}$ ${\mathrm{cm}}^{2}$ and a decay time for a small disturbance in carrier concentration in intrinsic material of 0.75 sec. The extension to the steady-state case of added current carriers is given, and estimates are included of the dependence of the quantities on temperature.

The phenomena of secondary ionization, avalanche breakdown and microplasma phenomena in p-n junctions are analyzed using a simplified model in which holes and electrons have identical properties described by four constants. Only two scattering processes for carriers are considered, each having two constants: generation of highest energy or Raman phonons, energy ER and mean-free-path LR; ionization or electron-hole pair production, threshold carrier energy Ei and mean-free-path Li. ER is determined from neutron scattering data; ER = 0·063 eV for Si and 0·037 eV for Ge. The other three constants are adjustable. Ei and Li/LR = r are chosen to fit data on quantum yield for photons with 1 <hv <5 eV using the formula Q = 3−2 exp(Eg+2Ei−hv)2rER. For silicon this gives Ei = 1·1 eV (which is equal to the energy gap Eg) and r = 17·5. For germanium Ei is also about 1·1 eV and r = 57. The simple model predicts that the ionization coefficient α(F) varies with field F as (qFrER)exp −(EiqLRF) which is in good agreement with data for electrons in silicon if LR is set equal to 50 Å. The model predicts an energy per pair for ionization by high-energy particles of about 2·2 Ei+rER which is in good agreement with measured values. It also predicts a hot-carrier random energy of about 0·2 eV for F = 400,000 V/cm, which agrees with the spectra of hole-electron recombination in microplasmas. Thus the three adjustable constants permit fitting six pieces of experimental data in four independent experiments in spite of the fact that the intricacies of the band structure are disregarded. The effects of statistical spatial fluctuations of donor and acceptor ions are considered and it is concluded that these will be randomly distributed according to a Poisson distribution. This randomness leads to a characteristic fluctuation voltage (qFBK)12 − 0·3 V for silicon where FB is the breakdown field, and the dielectric constant K = 1·04 × 10−12 F/cm for silicon. The effect of these fluctuations is to produce local regions in a p-n junction with breakdown about 0·7 V lower than the average in uncompensated material. The fluctuations of voltage are larger by [(Nd+Na)(Nd−Na)]12 in compensated material. The fluctuations can increase the apparent ionization coefficient substantially. Microplasma effects are considered and it is shown that in a junction with only the Poisson fluctuations the microplasma should be stabilized by an apparent series resistance due to space charge of magnitude 1υmaxK − 105 Ω where υmax = (ERm∗)12 is the limiting drift velocity. This is much larger than the spreading resistance term of magnitude 1μFBK − 2000 Ω. It is concluded that typical noisy microplasma phenomena are probably associated with localized structural defects probably having two characteristics: (1) they increase the effect ionization coefficient to a value greater than 105 cm−1 over a region less than 10−5 cm long; (2) they have a mechanism for capturing charge which increases the field once the microplasma has formed. Small SiO2 precipitates and dense arrays of dislocations appear to have the requisite properties. Metal precipitates in the space-charge layer produce “soft” reverse characteristics with localized currents of the form V6±1. Un modèle simplifié, où électrons et trous ont des propriétés identiques décrites par quatre constantes a été employé pour analyser les phénomènes d'ionisation secondaire, de microplasma et de rupture à avalanche. Seuls deux procédés de diffusion de porteurs, ayant chacun deux constantes, sont considérés: génération de phonons Raman ayant la plus grande énergie (énergie ER et libre parcours moyen LR); ionisation ou production d'électrons-trous (limite d'énergie de porteur Ei et libre parcours moyen Li). ER est déterminée par les données de diffusion des neutrons; ER = 0,063 eV pour le Si et 0,037 pour le Ge. Les trois autres constantes peuvent être ajustées. Ei et Li/LR = r ont été choisies de facon à s'adapter au rendement quantique des photons d'après la formule Q = 3−2 exp(Eg+2Ei−h)2rE, avec la limite 1 <h <5 eV. Ceci donne pour le silicium, Ei = 1,1 eV (valeur égale a l'intervalle d'énergie Eg) et r = 17,5. Pour le germanium, Ei est aussi environ 1,1 eV et r = 57. Le modèle simplifié prédit que le coefficient d'ionisation α(F) varie en fonction du champ F d'après l'expression (qFrER)exp −(EiqLRF), ce qui est en accord avec les données de Chynoweth pour les électrons dans le Silicium si L = 50 Å. Le modèle prédit une valeur de 2,2 Ei+ER pour l'énergie de chaque paire obtenue par ionisation de particule à haute ènergie; ce résultat s'accorde avec les valeurs mesurées. Il prèdit aussi une énergie aléatoire de porteur à chaud d'environ 0,2 eV pour F = 400.000 V/cm, en accord avec le spectre de recombinaisons trou-electron des microplasma. Ainsi les trois constantes qui peuvent être choisies permettent d'ajuster six données expérimentales dans quatre expériences indépendantes malgrè que l'on ignore les complications de la structure de bande. Les effets des fluctuations statistiques d'espace des ions donneurs et accepteurs sont analysés et on conclut que ceux-ci seront distribués aléatoirement en accord avec une distribution de Poisson. Cette tendance aléatoire menè a une tension caractéristique de fluctuation d'après l'équation (qFBK)12 − 0,3 V pour le Silicium, FB étant le champ de rupture et K la constante ` diélectrique (+1,04×10−12F/cm). L'effet de ces fluctuations est de produire des régions localisées dans une jonction p-n ayant des tensions de rupture d'environ 0,7 V de moins que la moyenne dans un materiau non-compensé. Les fluctuations peuvent augmenter sensiblement le coefficient d'ionisation apparent dans un matériau compensé, le facteur d'augmentation des fluctuations étant sol[(Nd+Na)(Nd−Na)]12 dans ces mêmes conditions. Les effets microplasma sont considérés et on démontre que dans une jonction, ne comprenant que les seules fluctuations de Poisson, le microplasma doit être stabilisé par une resistance en série apparente dûe à la charge d'espace de valeur 1υmax. K ⋍ 105 Ω ou υmax = (ERm∗)12 est la limite de la vitesse d'apport. La resistance d'extension donnée par la formule 1μFBK − 2000 Ω est beaucoup plus petite. On conclut que les phénomènes des microplasmas bruyants typiques sont peut-être associés avec des défauts de structure locaux ayant probablement les deux caractéristiques suivantes: (1) Ils augmentent le coefficient d'ionisation effectif d'une valeur plus grande que 10−1 cm sur une surface moins longue que 10−5 cm; (2) ils possèdent un mécanisme pour capturer des charges qui augmentent le champ, une fois le microplasma formé. De petits précipités de SiO2 et des assemblages denses de dislocations semblent avoir les propriétés requises. Des precipités de métal dans la couche de charge d'espace produisent des caractéristiques ramollies dans le sens inverti avec des courants localisés d'après V6±1. Die Phänomene der sekundären Ionisation, des Lawinenzusammenbruchs und Mikroplasma-Erscheinungen in p-n-Übergängen werden an einem einfachen Modell erörtert, in dem Löcher und Elektronen identische, durch 4 Konstante bestimmte Eigenschaften besitzen. Nur zwei Streuprozesse für Träger werden berücksichtigt, jeder mit zwei Konstanten: die Erzeugung von Phononen höchster Energie (Raman-Phononen), Energie ER, und die mittlere freie Weglänge LR; die Ionisation oder Elektron-Loch-Paar Erzeugung, Schwellenenergie der Träger Ei, mittlere freie Weglänge Li. ER wird durch Neutronenstreuung bestimmt; ER = 0,063 eV für Si und 0,037 eV für Ge. Die übrigen drei Konstanten sind regulierbar. Ei und Li/LR = r werden so gewählt, dass sie der Quantenausbeute für Photonen (1 <h <5 eV) entsprechen, wobei die Formel Q = 3−2 exp(Eg+2Ei−h)2rER benutzt wird. Für Silizium ist Ei = 1,1 eV (gleich der Energielücke Eg), r = 17,5. Für Germanium ist Ei ebenfalls etwa 1,1 eV und r = 57. Nach dem einfachen Modell soll der Ionisationskoeffizient α(F) mit den Feld nach folgender Beziehung variieren: (qFrERexp−(EiqLRF). Dies steht in guter Übereinstimmung mit Chynoweths Angaben für Elektronen in Silizium, wenn man LR = 50 Å setzt. Die Energie eines Paares bei Ionisation durch hochenergetische Teilchen soll nach dem Modell etwa 2,2Ei+rER betragen, was mit den Messungen gut übereinstimmt. Die statistische Energie der heissen Träger sollte etwa 0,2 eV sein, wenn F = 400 000 V/cm. Dies stimmt mit den Spektren der Rekombination von Löchern und Elektronen im Mikroplasma überein. Mit Hilfe der drei regulierbaren Konstanten lassen sich also 6 experimentelle Messungsergebnisse in 4 unabhängige Versuche einfügen, obwohl man die komplexe Bandstruktur nicht berücksichtigt. Die Effekte statistischer räumlicher Schwankungen der Donator und Akzeptorionen werden in Betracht gezogen, mit dem Ergebnis, dass diese nach einer Poissonschen Verteilung statistisch angeordnet sind. Dies führt zu einer charakteristischen Schwankungsspannung (qFBK)12 − 0,3 V für Silizium, wo FB das Feld beim Zusammenbruch und K die Dielektrizitätskonstante +1,04 × ×10−12F/cm für Si ist. Durch diese Schwankungen entstehen in einem p-n-Übergang lokale Zonen, deren Zusammenbruchsspannung um etwa 0,7 V niedriger ist als der Durchschnitt in nicht kompensiertem Material. Hier sind die Spannungsschwankungen um [(Nd+Na)(Nd−Na)]12 grösser. Diese Schwankungen können den scheinbaren Ionisationskoeffizienten beträchtlich erhöhen. Mikroplasmaerscheinungen werden dann erörtert, und es wird gezeigt, dass in einem Übergang, in dem nur Poisson-Schwankungen auftreten, das Mikroplasma durch einen scheinbaren Serienwiderstand stabilisiert werden sollte, der von einer Raumladung der Grösse 1υmaxK ⋍ 105 Ω herrührt, wo υmax = (ERm)12 der Grenzwert der Driftgeschweindigkeit ist. Dieser Wert ist viel grösser als der Ausbreitungswiderstand von 1υFBK ⋍ 2000 Ω. Typpsche Rauscherscheinungen im Mikroplasma werden lokalisierten Strukturdefekten zugeschrieben, die wahrscheinlich zwei Kennzeichen haben: (1) Sie erhöhen den effektiven Ionisationskoeffizienten auf einen Wert von über 105 cm−1 über eine weniger als 10−5 cm lange Zone. (2) Sie sind imstande, Ladung einzufangen, die nach Bildung des Mikroplasmas das Feld verstärkt. Kleine Niederschläge von SiO2 und dichte Anordnungen von Dislokationen scheinen die erforderlichen Eigenschaften zu besitzen. Metallniederschläge in der Raumladungsschicht erzeugen “weiche” Umkehrcharakteristiken mit lokalislierten Strömen der Form V6±1.

The general solution of the elastic equations for an arbitrary homogeneous anisotropic solid is found for the case where the elastic state is independent of one (say x3) of the three Cartesian coordinates x1, x2, x3. Three complex variables zl = x1 + plx2 (l = 1, 2, 3) are introduced, the pl being complex parameters determined by the elastic constants. The components of the displacement (u1, u2, u3) can be expressed as linear combinations of three analytic functions, one of z(l), one of z(2), and one of z(3). The particular form of solution which gives a dislocation along the x3-axis with arbitrary Burgers vector (a1, a2, a3) is found. (The solution for a uniform distribution of body force along the x3-axis appears as a by-product.) As is well known, for isotropy we have u3= 0 for an edge dislocation and u1 = 0, u2 = 0 for a screw dislocation. This is not true in the anisotropic case unless the x1x2 plane is a plane of symmetry. Two cases are discussed in detail, a screw dislocation running perpendicular to a symmetry plane of an otherwise arbitrary crystal, and an edge dislocation running parallel to a fourfold axis of a cubic crystal. La solution générale des équations de l'élasticité pour un solide anisotrope, homogène est trouvée dans le cas où l'état élastique est indépendant d'une (mettons x3) des trois coordonnées cartésiennes x1, x2, x3. Trois variables complexes z(l) = x1 + p(l)x2, (l = 1,2,3) sont introduites, les p(l) étant des paramètres complexes déterminés par les constantes d'élasticité. Les composantes du déplacement (u1, u2, u3) peuvent être exprimées comme des combinaisons linéaires de trois fonctions analytiques, une de z(1), une de z(2), et une de z(3). Une forme particulière de solution est trouvée, elle donne une dislocation le long de l'axe x3 avec un vecteur de Burgers arbitraire (a1, a2, a3). (En même temps apparait, comme sous-produit, la solution dans le cas d'une distribution uniforme de la force interne le long de l'axe x3). Dans le cas d'isotropie, u3 = 0 pour une dislocation-coin et u1 = 0, u2 = 0 pour une dislocation-vis. Ceci n'est pas vrai dans le cas d'anisotropie, à moins que le plan x1x2 soit un plan de symétrie. Deux cas sont discutés en détail, une dislocation-vis perpendiculaire à un plan de symétrie d'un cristal, qui est d'autre part quelconque, et une dislocation-coin parallèle à un axe quaternaire d'un cristal cubique. Die allgemeine Lösung der Elastizitätsgleichungen für einen willkürlichen anisotropen Festkörper wird für den Fall angegeben, in dem der Elastizitätszustand von einer (zB.x3) der drei Cartesischen Koordinaten x1, x2, x3 unabhängig ist. Es werden drei komplexe Veränderliche z(l) = x1 + p(l)x2 (l = 1, 2, 3) eingeführt, wobei die p(l) komplexe Parameter sind, die durch die Elastizitätskonstanten bestimmt sind. Die Verschiebungskomponenten (u1, u2, u3) können als lineare Kombinationen von drei analytischen Funktionen, nämlich als eine von z1, eine von z2 und eine von z3, ausgedrückt werden. Eine spezielle Form der Lösung wurde für eine Versetzung in der x3-Achse mit willkürlichem Burgers-Vektor (a1, a2, a3) gefunden. (Als Nebenresultat ergibt sich die Lösung für eine gleichförmige Verteilung der Kraft entlang der x3-Achse.) Bekanntlich gilt im isotropen Fall für eine Stufenversetzung u3 = 0 und für eine Schraubenversetzung u1 = 0 und u2 = 0. Im anisotropen Fall trifft das nicht zu, ausser wenn die x1x2 Ebene die Symmetrieebene ist. Zwei Fälle werden eingehend diskutiert: (1) Eine Schraubenversetzung, die senkrecht zu einer Symmetrieebene eines sonst willkürlichen Kristalles verläuft, (2) Eine Stufenversetzung, die parallel einer der vierfachen Achsen eines kubischen Kristalles verläuft.

The theory for a new form of transistor is presented. This transistor is of the "field-effect" type in which the conductivity of a layer of semiconductor is modulated by a transverse electric field. Since the amplifying action involves currents carried pre-dominantly by one kind of carrier, the name "unipolar" is proposed to distinguish these transistors from point-contact and junction types, which are "bipolar" in this sense. Regarded as an analog for a vacuum-tube triode, the unipolar field-effect transistor may have a mμ of 10 or more, high output resistance, and a frequency response higher than bipolar transistors of comparable dimensions.

The prognostication of head and neck squamous cell carcinoma (HNSCC) is largely based upon the tumor size and location and the presence of lymph node metastases. Here we show that gene expression patterns from 60 HNSCC samples assayed on cDNA microarrays allowed categorization of these tumors into four distinct subtypes. These subtypes showed statistically significant differences in recurrence-free survival and included a subtype with a possible EGFR-pathway signature, a mesenchymal-enriched subtype, a normal epithelium-like subtype, and a subtype with high levels of antioxidant enzymes. Supervised analyses to predict lymph node metastasis status were approximately 80% accurate when tumor subsite and pathological node status were considered simultaneously. This work represents an important step toward the identification of clinically significant biomarkers for HNSCC.

The elastic constants of nickel crystals, and their variation with magnetic field (ΔE effect), have been measured by a 10-megacycle ultrasonic pulsing method. The constants of three crystals agree well with one another when the crystals are magnetically saturated, but vary with domain distribution when demagnetized. The maximum ΔE effect observed is much less (3%) than has been observed at lower frequencies (20%). By measuring the ΔE effect and the decrement of polycrystalline rods at low frequencies, it is shown that the small effect observed at 10 megacycles is due to a relaxation in the domain wall motion due to microeddy-current damping. From the initial slope of the decrement-frequency curve, and also from the frequency of maximum decrement, the size of the average domain is found to he about 0.04 mm. Actual domains in single nickel crystals have been observed optically by Williams, who finds domain widths of 0.02 to 0.2 mm.

Experimental results are given on the velocity of propagation of a single domain boundary in a crystal of silicon iron with a simple domain structure. In weak applied magnetic fields (\ensuremath{\sim}0.003 oersted) the velocity is given by a relation of the form $v=G(H\ensuremath{-}{H}_{0})$, where $G$ is a constant \ensuremath{\sim}4 cm/sec./oersted in this crystal, and ${H}_{0}\ensuremath{\cong}0.003$ oersted is the starting field. Calculation of the eddy current losses accompanying the motion of a plane boundary gives a theoretical expression for $G$ in good agreement with experimental values; the predicted linear dependence on the resistivity was approximately verified by measurements at 78\ifmmode^\circ\else\textdegree\fi{}, 194\ifmmode^\circ\else\textdegree\fi{}, and 293\ifmmode^\circ\else\textdegree\fi{}K. In stronger fields (&gt;5 oersteds) there is evidence that the wall closes on itself, and the experimental velocity of collapse of the wall as deduced from flux changes agrees with the theoretical result based on a model of eddy current losses accompanying a collapsing cylindrical boundary. The results have a bearing on the well-known eddy current anomaly, namely, the fact that the total loss in a ferromagnetic material undergoing a.c. magnetization is often two or three times larger than the eddy-current and hysteresis losses calculated in the usual way assuming a spatially uniform and isotropic classical permeability.

The mobilities of holes injected into $n$-type germanium and of electrons injected into $p$-type germanium have been determined by measuring transit times between emitter and collector in single crystal rods. Strong electric fields in addition to those due to injected current were employed so that spreading effects due to diffusion were reduced. The mobilities at 300\ifmmode^\circ\else\textdegree\fi{}K are 1700 ${\mathrm{cm}}^{2}$/volt-sec for holes and 3600 ${\mathrm{cm}}^{2}$/volt-sec for electrons with an error of probably less than five percent. The value for electrons is about 20 percent higher than the best estimates obtained from the conventional interpretation of the Hall effect and the difference may be due to curved energy band surfaces in the Brillouin zone. Studies of rates of decay indicate that recombination of holes and electrons takes place largely on the surface of small samples with constants varying from ${10}^{2}$ to &gt; ${10}^{4}$ cm/sec for special treatments.

The effects of diffusion of electrons through a thin $p$-type layer of germanium have been studied in specimens consisting of two $n$-type regions with the $p$-type region interposed. It is found that potentials applied to one $n$-type region are transmitted by diffusing electrons through the $p$-type layer although the latter is grounded through an ohmic contact. When one of the $p\ensuremath{-}n$ junctions is biased to saturation, power gain can be obtained through the device. Used as "$n\ensuremath{-}p\ensuremath{-}n$ transistors" these units will operate on currents as low as 10 microamperes and voltages as low as 0.1 volt, have power gains of 50 db, and noise figures of about 10 db at 1000 cps. Their current-voltage characteristics are in good agreement with the diffusion theory.

Magnetic powder patterns have been obtained on electrolytically polished surfaces of single crystals of iron containing 3.8 weight percent silicon. Domains are easily visible, outlined by accumulations of colloidal magnetic particles. Several techniques have been developed that enable the direction of magnetization in each domain to be determined. Many types of domain patterns are observed, depending on the orientation of the surface with respect to the crystal axes. The simpler patterns can now be interpreted in some detail, and support the idea that the internal domain structure is relatively simple and is usually composed of a series of plates or slabs magnetized at 45\ifmmode^\circ\else\textdegree\fi{} or 90\ifmmode^\circ\else\textdegree\fi{} to the plate length. In one case it is verified that the plate thickness depends on plate length in approximate accordance with theory; and, for the more complicated "tree" patterns, comparison of theory with experiment shows that good agreement can be obtained using theoretical values of the wall energy. Further verification of the theory of Bloch walls is obtained by determining from experiment the change in spin orientation on traversing the wall.

Head and neck squamous cell carcinoma (HNSCC) is a frequently fatal heterogeneous disease. Beyond the role of human papilloma virus (HPV), no validated molecular characterization of the disease has been established. Using an integrated genomic analysis and validation methodology we confirm four molecular classes of HNSCC (basal, mesenchymal, atypical, and classical) consistent with signatures established for squamous carcinoma of the lung, including deregulation of the KEAP1/NFE2L2 oxidative stress pathway, differential utilization of the lineage markers SOX2 and TP63, and preference for the oncogenes PIK3CA and EGFR. For potential clinical use the signatures are complimentary to classification by HPV infection status as well as the putative high risk marker CCND1 copy number gain. A molecular etiology for the subtypes is suggested by statistically significant chromosomal gains and losses and differential cell of origin expression patterns. Model systems representative of each of the four subtypes are also presented.

Metal precipitates in junctions were found to cause excess reverse current below avalanche breakdown, which is conjectured to be due to Zener tunneling at localized high-field points. This current varies as Vn where n is between 4 and 7. By a potential plotting method, it was shown that this excess current is not caused by a surface effect. Metal precipitates can be removed or prevented by ``gettering'' from surface layers. Metallic coatings and certain glassy oxide layers were investigated. Results indicate that layers of Ni and Zn have a limited gettering effect. Glassy layers, especially those of boron and phosphorus, have the greatest gettering effect.

A flaw with $s$ electronic units of negative charge makes transitions to charge $s+1$ by hole emission at rate $e(p, s)$ or by electron capture at rate $nc(n, s)$ and returns to charge $s$ at rates $e(n, s+1)$ and $pc(p, s+1)$. Here $n$ is the electron density in the conduction band and $p$ is the hole density in the valence band. The steady-state ratio of populations ${N}_{s+1}$ to ${N}_{s}$ is given by $\frac{c(n, s)[n+{n}^{*}(s+\frac{1}{2})]}{c(p, s+1)[p+{p}^{*}(s+\frac{1}{2})]},$ where ${n}^{*}(s+\frac{1}{2})=\frac{e(p, s)}{c(n, s)}$ and ${p}^{*}(s\frac{1}{2})=\frac{e(n, s+1)}{c(p, s+1)}$. This distribution corresponds to an effective Fermi level for the flaws only for the condition of thermal equilibrium. Expressions for the recombination rate based on the steady-state distribution are derived. For a given transition $s\ensuremath{\rightleftarrows}s+1$ the following special cases are defined: (1) denuded: $n&lt;{n}^{*}$, $p&lt;{p}^{*}$; (2) $n$-dominated: $n&gt;{n}^{*}$, $p&lt;{p}^{*}$; (3) $p$-dominated: $n&lt;{n}^{*}$, $p&gt;{p}^{*}$; (4) flooded: $n&gt;{n}^{*}$, $p&gt;{p}^{*}$. Diagrams which aid in visualizing the relative importance of the various transitions are presented. Some speculations on the nature of trapping centers are given.

It is well-known that some workers in scientific research laboratories are enormously more creative than others. If the number of scientific publications is used as a measure of productivity, it is found that some individuals create new science at a rate at least fifty times greater than others. Thus differences in rates of scientific production are much bigger than differences in the rates of performing simpler acts, such as the rate of running the mile, or the number of words a man can speak per minute. On the basis of statistical studies of rates of publication, it is found that it is more appropriate to consider not simply the rate of publication but its logarithm. The logarithm appears to have a normal distribution over the population of typical research laboratories. The existence of a "log-normal distribution" suggests that the logarithm of the rate of production is a manifestation of some fairly fundamental mental attribute. The great variation in rate of production from one individual to another can be explained on the basis of simplified models of the mental processes concerned. The common feature in the models is that a large number of factors are involved so that small changes in each, all in the same direction, may result in a very large change in output. For example, the number of ideas a scientist can bring into awareness at one time may control his ability to make an invention and his rate of invention may increase very rapidly with this number.

The structural simplicity of two-terminal compared to three-terminal devices indicates the potential importance of two terminal devices employing semiconductors and having negative resistance at frequencies properly related to the transit time of carriers through them. Such negative resistances may be combined with unsymmetrically transmitting components, such as gyrators or Hall effect plates, to form dissected amplifiers that may be made to simulate conventional three-terminal amplifiers and operate at high frequencies. The characteristics of several structures are analyzed on the basis of theory and it is found that negative resistances are possible for properly designed structures.

A localized flaw such as a vacancy-interstitial pair, gold atom, or small void is considered. It is found that the charge situation can be described by a set of energy levels which are independent of the Fermi level but which are temperature-dependent. If the flaw is electrically neutral for a certain position of the Fermi level, then as the Fermi level is raised from the neutral level successively above each higher-lying level of the set, the flaw acquires an additional electron unit of negative charge. These levels are called the first-acceptor level, second-acceptor level, etc. The energy levels are essentially equal to $\mathrm{kT}\mathrm{ln}(\frac{{Z}_{1}}{{Z}_{2}})$, where ${Z}_{1}$ and ${Z}_{2}$ are the contributions of the flaw to the state sum for the system for the two conditions of charge. Similarly, as the Fermi level is lowered below the neutral point, it passes the first-donor level, second-donor level, etc., and the flaw acquires charges of plus one, plus two, etc. The statistics are derived for the distribution for the various conditions of charge, referred to as first-donor condition, neutral condition, first-acceptor condition, etc.

The energies of the two-phonon summation bands and the reststrahlen bands have been measured in $\mathrm{Ga}{\mathrm{As}}_{x}{\mathrm{P}}_{1\ensuremath{-}x}$ single crystals. The data were obtained by observing the transmittance and the reflectivity at 300\ifmmode^\circ\else\textdegree\fi{}K in the region of 400 to 800 ${\mathrm{cm}}^{\ensuremath{-}1}$ and 220 to 500 ${\mathrm{cm}}^{\ensuremath{-}1}$, respectively. Crystals were prepared by open-tube epitaxial vapor-growth techniques and were not subject to any free-carrier absorption in the near infrared. The alloys show absorption peaks at frequencies which are only slightly shifted from the transverse optic $\mathrm{TO}(\ensuremath{\Gamma})$ phonons, as well as several optical and acoustical zone-boundary phonons, characteristic of both GaP and GaAs. The reststrahlen-like band spectra of these alloys are explained by a virtual-crystal model in which average parabolic potentials are given to the three species of atoms in the lattice. This model does not require the assumption of gross composition inhomogeneities, which are known to be absent in these crystals.

The theory of order and disorder, in the form used by Bragg and Williams, is extended to arbitrary composition of the constituent elements. The work is based upon the nearest neighbor interaction assumption of Bethe and the connection between the Bethe and Bragg-Williams theory is shown. In order to extend the Bragg-Williams theory to compositions other than 25 and 50 atomic percent, new definitions of order are developed. The results are presented in terms of phase diagrams and curves showing energy vs. temperature, specific heat vs. temperature and state order vs. temperature. These results are of importance in giving a general picture of the order-disorder transformation for a wide composition range. They are not in detailed accord with experiment due to the rather idealized picture underlying the nearest neighbor assumption.

A situation analogous to thermionic emission into vacuum can occur in semiconductors. A semiconductor analog for a plane parallel vacuum diode may consist of two layers of $n$ type semiconductor bounding a plane parallel slab of pure semiconductor. The current density analogous to Child's law is $J=\frac{9\ensuremath{\kappa}{\ensuremath{\epsilon}}_{0}\ensuremath{\mu}{V}^{2}}{8{W}^{3}}$, where $\ensuremath{\kappa}=\mathrm{dielectric}\mathrm{constant}$, ${\ensuremath{\epsilon}}_{0}=\mathrm{mks}\mathrm{permittivity}$, $\ensuremath{\mu}=\mathrm{mobility}$, $V=\mathrm{applied}\mathrm{voltage}$, and $W=\mathrm{thickness}\mathrm{of}\mathrm{pure}\mathrm{region}$. The condition prevailing at the space-charge maximum is analyzed taking into account diffusion due to random thermal motion. Brief discussions are given of the effect of fixed space charge, the dependence of mobility upon electric field strength and the role of space-charge limited emission in a new class of unipolar transistors.

The problem of the potential distribution, current, and electron transit time resulting from the perpendicular injection of electrons into the space between parallel planes is considered. The electrons are assumed to be injected uniformly with velocities corresponding to the potential of the plane through which they are injected. Consideration of all possible solutions of the basic equation shows that four general types of potential distribution are possible. Curves are given which enable the easy calculation of transmitted current and transit time and show the complete potential distribution for any concrete example. The case for current injected through both planes is also considered. The complete mathematical treatment is given in the appendix.

The Wigner and Seitz method of cellular potentials has been applied to the calculation of wave functions in NaCl. A renormalized Hartree field has been used around the Cl and the Prokofjew field around the Na. The relative heights of the potentials are determined by use of Madelung's number. The problem of joining the functions at the cell boundaries has been treated by the Slater method of fitting $\ensuremath{\psi}$ and ${\ensuremath{\psi}}^{\ensuremath{'}}$ at midpoints. For the outer Cl electrons a reasonable approximation is to join at Cl---Cl midpoints only. This gives rise to a face-centered lattice for which solutions of the Slater conditions have been found by Krutter. Several new solutions have been derived which allow fairly accurate energy contours in momentum space to be drawn for the Cl $3p$ band. If the joining is made at Cl---Na midpoints alone, a large number of unsatisfactory zero-width bands arise. When both Cl---Cl and Cl---Na midpoints are used, the boundary conditions can be treated only for special cases. For these they are consistent with the Cl---Cl solutions. Several attempts to calculate the ultraviolet absorption frequency are described and the difficulties involved are discussed.

The relations are investigated between three types of theory for explaining absorption of light by ionic crystals: absorption by independent atoms or ions, absorption according to Frenkel's excitation waves, and absorption according to energy bands and lattice functions, as used in the theory of metals. It is shown that each method leads to a set of unperturbed wave functions, which are related to each other by linear combinations, and that no one set is correct at the actual distance of separation in the crystal. Instead, combinations must be used, leading both to continuous absorption as in the energy bands, and to one or two discrete lines in connection with each continuum, as in absorption by independent atoms or in excitation waves. These conclusions are compared with experiment, explaining in a general way the sharp structure observed both in the near and far ultraviolet absorption spectra of these crystals. The discussion deals throughout with the undistorted crystal, leaving out of account the new absorption bands which are known to appear in these crystals after considerable illumination, resulting from the deposition of free alkali in the crystal.

The self-diffusion of copper has been measured with a radioactive isotope prepared by neutron bombardment of zinc. The isotope is electroplated in a thin layer upon the surface of a copper disk. By measuring the decrease in $\ensuremath{\beta}$-ray emission from the sample due to the penetration of the radioactive copper, the self-diffusion constant is determined within the limits of accuracy as 11 ${\mathrm{cm}}^{2}$/sec. $\mathrm{exp}(\ensuremath{-}\frac{57,200}{\mathrm{RT}})$. Methods of analyzing such data are given and the significance of the variation of activation energy between self-diffusion and heterogeneous diffusion is discussed.

The behavior of thickness/shear-mode quartz resonators is explained both mathematically and experimentally in terms of lateral standing-wave trapped-energy modes. A cutoff phenomenon, similar to that occurring in optical total internal reflection, results in energy trapping or the restriction of vibratory energy almost exclusively to the electroded region of a resonator, with an energy distribution decreasing exponentially with distance from the electrode edge. Consideration of boundary conditions at the electrode edges of an idealized two-dimensional model yields an expression for the eigenfrequencies of symmetric inharmonic overtone modes (lateral standing waves) that can exist in the electroded region of fundamental- and harmonic-mode resonators. Design formulas for the suppression of these unwanted modes are included. They show that electrode thickness and lateral dimensions can be traded off against one another to obtain a wide range of motional parameters. Previously, unwanted responses were eliminated by restricting the electrode diameter to empirically established values. The present understanding has led to a reduction in resonant resistance and an increase in motional capacitance by at least a factor of four with hf and vhf fundamental- and harmonic-mode filter crystals. Experimental data that verify results predicted by energy-trapping theory are given, and application to design of single- and multi-electrode resonators is considered. Specific examples in the 10- to 180-MHz frequency range are given.

The solubility of a charged impurity in a semiconductor depends upon the Fermi level. This dependence may be understood in terms of a conceptual model in which an impurity is allowed to diffuse in a specimen containing a $p\ensuremath{-}n$ junction, so that the Fermi level varies in respect to the band edges. If the impurity can exist in many states of charge (i.e., is a "flaw"), then the concentration of flaws with charge $r$ times the electronic charge varies as the $r\mathrm{th}$ power of the hole density. Summing the concentrations for the different states of charge gives the solubility and its dependence upon hole concentration, and, hence, Fermi level.

A hollow rectangle cut from a single crystal of 3.8 percent silicon iron has been studied with the aid of powder patterns and flux measurements. The edges and surfaces were all cut accurately parallel to 100&gt;, the directions of easy magnetization. The domain pattern consists of 8 domains, four forming an inner rectangle magnetized in one direction and the others forming an oppositely magnetized outer rectangle. Changes in magnetization occur by the growth of one set of domains at the expense of the other. In the saturated condition, each leg of the rectangle is one domain about 1.5\ifmmode\times\else\texttimes\fi{}0.1\ifmmode\times\else\texttimes\fi{}0.1 cm in size. Implications of these results in connection with Barkhausen effect are discussed, and a method of measuring the energy of the Bloch wall is proposed.

Abstract Objectives/Hypothesis: Preferred treatment of oral/plunging ranulas remains controversial. We present our experience with ranulas at the University of North Carolina (UNC) and review the literature. Methods: Retrospective review. From 1990 to 2007, 16 oral ranulas and 10 plunging ranulas were treated at UNC. Combining the UNC series with the literature identified 864 cases for review. An online survey was conducted to identify current treatment patterns. Results: In the UNC series, procedures for oral ranulas varied from ranula excision (50%), combined ranula and sublingual gland excision (44%), excision of the ranula along with the sublingual gland and submandibular gland (6%). A cervical approach was used in nine plunging ranula cases. One case was treated transorally with sublingual gland removal and evacuation of the ranula. Otherwise, the plunging ranula was removed along with the sublingual gland (20%), submandibular gland (50%), or both (20%). One hundred fifty‐one complications were identified from the literature. Recurrence was considered a complication and was most prevalent (63%). Nonrecurrent complications included tongue hypesthesia (26%), bleeding/hematoma (7%), postoperative infection (3%), and Wharton's duct injury (1%). Sublingual gland excision yielded the fewest complications (3%). Procedures and associated complication rates were: transoral excision of sublingual gland (3%); transoral excision of sublingual gland and ranula (12%); marsupialization (24%); transcervical excision of sublingual gland, submandibular gland, and ranula (33%); OK‐432 (49%); and aspiration (82%). Conclusions: Based on our review, definitive treatment yielding lowest recurrence and complication rates for all ranulas is transoral excision of the ipsilateral sublingual gland with ranula evacuation. Laryngoscope, 2009

Summary Energy trapping is proposed as an explanation for the behavior of high frequency quartz filter crystals. Published elastic wave theory for lossless wafers includes a cut-off phenomenon: If the portion of the wafer surrounding the resonator has a cut-off frequency higher than the exciting frequency:, the resulting vibratory energy is essentially confined to the resonator with an energy distribution decreasing exponentially with distance away from the resonator. This exponential decay is not associated with energy loss but acts to trap the oscillating energy within a confined region. This energy trapping gives a basis for the high Qm observed for crystals mounted on low Q supports and for the low inter-resonator coupling observed for multi-resonator wafers. Measurements which support the energy trapping mechanism theory for exponential energy decay with distance have been obtained by varying inter-resonator spacing or distance from resonator to wafer edge These findings are applicable to improved design for high frequency filter crystals with both single and multiple electrode pairs.

The noise in secondary-emission electron multipliers is considered from a theoretical viewpoint. The noise properties of a stage are correlated with its secondary-emission properties: the mean value m and mean-square deviation δ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> of the number of secondaries per primary. If IpA2 and IsAf2 denote the mean-square noise current lying in the frequency band Δf in the primary- and secondary-electron currents, then 1aAf2= m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> I, PV2+ 622eI,, Af where Ī <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</inf> is primary direct current. This result is applied to many-stage multipliers. For n similar stages I, f2= M2I2PA2+ f 2[ M( M )/ m( m21)] 2eIpAf where M=m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</sup> is the over-all gain of the multiplier.

A very thin layer of radioactive copper was electrolytically deposited on a copper blank. The surface was then oxidized in air at 1000°C for 18 minutes, giving an oxide layer with a thickness of 1.25×10−2 cm. After quenching, successive layers of the oxide were removed chemically, and the copper activity in each layer was measured. The observed self-diffusion of radioactive copper in the oxide agrees quantitatively with a theory based on the following assumptions: (a) The oxide grows by diffusion of vacant Cu+ sites from the outer surface of the oxide inward to the metal. (b) The concentration of vacant sites as the oxygen-oxide interface is independent of the oxide thickness, and drops linearly from this constant value to zero at the metal boundary. (c) Accompanying the inward flow of vacant sites, there is a flow of positive electron holes such as to maintain electrical neutrality. (d) Self-diffusion of copper ions takes place only by motion into vacant sites. The results give a fairly direct confirmation of the theory of oxidation first suggested by Wagner.

An improved experimental technique is described for the investigation of carrier multiplication in very small areas, particularly microplasmas. A light spot of a few microns diameter is positioned to cover a microplasma of comparable or smaller size and the multiplied photocurrent is measured as a function of reverse voltage. When the size of the microplasma is much smaller than the light spot, then the multiplication as a function of voltage is dependent upon the characteristics of the microplasma in an upper voltage range just below the microplasma breakdown voltage. In a lower voltage range the microplasma has negligible effect on multiplication. By comparing for the upper and lower voltage ranges the behavior of the reciprocal of the multiplication factor as a function of voltage, it is possible to determine that the diameters of the area of the microplasma regions vary from less than one to more than 5 μ. Multiplication factors as high as 106 were measured. At high multiplication (M&amp;gt;100), a deviation from the theoretically expected linear dependence of 1/M vs V is observed. This deviation can be described by two effects: (1) the influence of the space charge of the multiplied carriers and (2) the pulsing mechanism of the microplasma. Because of this deviation, microplasma diameters of less than 1 μ cannot be accurately determined. Another consequence of the pulsing effect is an apparent negative resistance in the V—I characteristic of a diode containing a microplasma. Dependence of the apparent negative resistance on load resistance, shunting capacity, and light intensity was investigated, and can be explained with the pulse model.

The cellular method of constructing wave functions for electrons in crystals developed principally by Wigner and Seitz and Slater is tested by applying it to an artificial crystal in which the potential is constant. Knowledge of the exact solutions for this case, plane waves, shows that the cellular method is quite accurate in the first Brillouin zone but may be in error by a factor of two in the second. Hence calculations of occupied levels in Li and Na are probably quite good; for Cu, Ca, diamond, LiF, and NaCl the errors will be larger. Calculations of excited states are likely to be very much in error. The accuracy of the cellular method is shown to improve very slowly with increasing number of continuity conditions.

Diffusion fronts in samples containing grain boundaries are spike shaped. Velocity of spike advance and angle between spike and boundary are measured. The "spike-velocity method" of analysis permits evaluation of two effective widths, ${W}_{D}$ and ${W}_{0}$, which describe the diffusion properties of the boundary. This method has been used to analyze data on phosphorus diffusion into boron-doped silicon at 1200\ifmmode^\circ\else\textdegree\fi{}C and 1050\ifmmode^\circ\else\textdegree\fi{}C. It is concluded that an enhanced diffusion current flows along each dislocation of the grain boundary over a cross section less than one Burgers-vector square. The diffusion current density is about 300 000 times that of the bulk. This corresponds to an energy of 1.5 ev by which grain boundary diffusion is favored over the bulk diffusion. This enhancement is believed to be caused by enrichment of phosphorus and also partly by the extra concentration of vacancies near the dislocation cores. Some possible extensions of the studies to include saturation effects at the dislocation cores are discussed.

Techniques are described which utilize the "print out effect" to obtain both the direction and velocity of photoelectrons in silver chloride crystals in an electric field. Hall mobility of the electrons is calculated from their change in direction produced by crossed electric and magnetic fields. Drift mobility of the electrons is obtained by measurement of their velocity in known electric fields. The value obtained for the Hall mobility ($R\ensuremath{\sigma}$) multiplied by $\frac{8}{3\ensuremath{\pi}}$ is 51 ${\mathrm{cm}}^{2}$/volt sec at 25\ifmmode^\circ\else\textdegree\fi{}C. The values obtained for the drift mobility are shown to be a function of temperature. A value of 49.5 ${\mathrm{cm}}^{2}$/volt sec was obtained at 25\ifmmode^\circ\else\textdegree\fi{}C, which is within experimental error of $(\frac{8}{3\ensuremath{\pi}})R\ensuremath{\sigma}$, indicating that acoustical scattering is the principal mechanism and that temporary trapping is unimportant. A summary of the behavior of conduction electrons in silver chloride, calculated from the results of these experiments, is included.

The electronic mechanisms that are of chief interest in transistor electronics are discussed from the point of view of solid-state physics. The important concepts of holes, electrons, donors, acceptors, and deathnium (recomibination center for holes and electrons) are treated from a unified viewpoint as imperfections in a nearly perfect crystal. The behavior of an excess electron as a negative particle moving with random thermal motion and drifting in an electric field is described in detail. A hole is similar to an electron in all regards save sign of charge. Some fundamental experiments have been performed with transistor techniques and exhibit clearly the behavior of holes and electrons. The interactions of holes, electrons, donors, acceptors, and deathnium give rise to the properties of p-n junctions, p-n junction transistors, and Zener diodes. Point-contact transistors are not understood as well from a fundamental viewpoint. A new class of unipolar transistors is discussed. Of these, the analog transistor is described in terms of analogy to a vacuum tube.

Holes injected by an emitter point into thin single-crystal filaments of germanium can be detected by collector points. From studies of transient phenomena the drift velocity and lifetimes (as long as 140 microseconds) can be directly observed and the mobility measured. Hole concentrations and hole currents are measured in terms of the modulation of the conductivity produced by their presence. Filamentary transistors utilizing this modulation of conductivity are described.

A new and simple electron microscope has been designed for small cylindrical filaments. Die marks are found to be prominent in the electron images of all drawn wires. The activation of thoriated tungsten has been studied. Electron emission from single crystals grown in drawn pure tungsten filaments varies around the wire circumference and depends systematically on crystallographic direction. This variation of emission with crystallographic direction is more pronounced and complex when the filament is allowed to self-activate in cesium or potassium vapor.

• Stage I and II squamous cell cancers of the oral cavity have a high recurrence rate given their size and relative amenability to surgical resection. It has been suggested that one way to decrease this recurrence rate is to augment the surgical resection of these tumors with either elective neck dissection or radiation therapy. However, this would expose a significant number of patients to the unnecessary morbidity associated with either of these modalities. In an attempt to identify those patients most at risk for recurrence, we retrospectively determined the clinical and histologic factors that were associated with recurrence in 49 patients with stage I and II oral cavity cancer. Multiple regression analysis revealed that when various interactions between variables were controlled for, only the presence of a positive surgical margin or a tumor depth greater than 5 mm was significantly associated with recurrence. Each individually increased the likelihood of recurrence almost threefold. (<i>Arch Otolaryngol Head Neck Surg.</i>1992;118:483-485)

External laryngeal trauma (ELT) is a rare but clinically important injury.To perform the first population-based, time series analysis of the epidemiology, management, and outcomes of ELT using an 11-state, inpatient sample database containing more than 54 million patients.Three hundred ninety-two patients with a primary or secondary diagnosis of ELT were identified. Over a 5-year period, the incidence of ELT in this series was 1/137,000. The mean (+/-SD) age was 37 (+/-7) years, and the overall mortality rate was 2.04%. Two hundred forty-eight patients required surgical intervention.The average length of stay for 67 patients not requiring surgical intervention for any injury was 3 (+/-2) days, with no mortality. One hundred eighty patients underwent endoscopy, with 14 requiring tracheotomy alone and 57 requiring tracheotomy plus laryngeal repair. The average length of stay and the mortality rate were higher in these latter groups. Overall, 139 patients underwent tracheotomy, with a mortality rate of 5%, while 96 patients underwent laryngeal repair, with a mortality rate of 1%. Surgical treatment was performed in 140 patients with ELT within 24 hours after presentation, while another 60 received treatment within 48 hours. Associated injuries included skull base or intracranial injury (13%), open neck injury (9%), cervical spine injury (8%), and esophageal or pharyngeal injury (3%).External laryngeal trauma is a rare injury, with most patients requiring surgical intervention.

The failure in 1945 of experiments proposed by Shockley, on what today would be called thin-film field-effect transistors, was a creative failure that stimulated Bardeen in early 1946 to propose that a surface-state shield blocked the field from the semiconductor's interior. Bell Laboratories' "transistor group to be" for the next eighteen months focused, not on practical, but on scientific aspects of the failure. Focus on the practical resumed (with a step-function increase, lasting several months, in "the will to think" about new concepts of semiconductor amplifiers, as measured by the rate of filling of laboratory notebook pages by Bardeen, Brattain, and Shockley) on 17 November 1947, when in his surface-state research, Brattain penetrated the shield by applying the field through an electrolyte. Within six days, patentable field-effect transistor inventions were conceived. Although useless as devices, these inventions were creative failures used by Bardeen and Brattain to discover the point-contact transistor three weeks later. Five weeks after this discovery, Shockley conceived the junction transistor while designing "imref" experiments on the point-contact transistor's inversion layer so that in 1951, the point-contact transistor in its turn became a creative failure when replaced by the junction transistor whose conception it had aided. But the path of thought to the conception of the junction transistor and the subsequent path to its practical realization are proven to be highly indirect by historical research on laboratory notebook entries. Specifically, Shockley's conception of the junction transistor was delayed by at least four months because he missed opportunities, obvious by hindsight, to recognize the possibility of minority carrier injection. The author hopes that the presentation of details of his limitations in making this important invention may help readers to accept their own limitations and, thereby, to become more persistent and, hence, creative.

The effects of charges on oxide covered silicon surfaces were studied utilizing the Kelvin vibrating condenser method to measure contact potential differences. This technique was used to determine the amount of electrical charges in or on the insulating layer. The results were compared with the values of total charge obtained by integrating ammeter currents. From these experiments it can be concluded that the measured contact potential difference was caused by charges located on the outer surface of the oxide layer. This agrees with the model of surface ion motion proposed previously by Atalla and coworkers.

A method of treating transport of injected minority carriers is developed applicable to cases in which the physical dimension and the mean free path for capture may be less than the mean free path for scattering. The basic differential equations of scattering and capture are those of the conservation of flux method of McKelvey, Longini, and Brody, and the results agree with theirs, the new feature being a demonstration that the basic equations are equivalent to a continuity equation of the conventional form but with a diffusion constant reduced by including the effect of capture in shortening the mean free path. This method of treatment reduces the problems to a familiar form when suitable boundary conditions are introduced. The basic differential equations of scattering and capture are shown to correspond to certain simplifying and restricting assumptions about the carrier velocity distributions. The treatment is extended from the case of one dimension with zero electric field to three dimensions with electric fields.

The statistics of recombination and of trapping of electrons and holes through traps of a single species are presented. The results of the Shockley-Read recombination theory are derived and more fully interpreted. A level of energy known as the equality level is introduced. When the Fermi level lies at this level, the four basic processes of electron capture, electron emission, hole capture, and hole emission all proceed at equal rates. Transient cases for large trap density are presented.

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Recently a far more intimate and detailed view of the basic processes by which electrons carry current has been made possible by new experiments based upon the invention of the transistor.

By the calculation of transitions between states appropriate to electrons moving in a large uniform electric field superimposed on a periodic crystal field, it is shown the probabilities of scattering by lattice vibrations or imperfections are independent of the uniform field and are given by the usual expressions derived for zero field. This justifies the procedure of treating acceleration by the field and scattering as independent processes.

CT Detection of Mandibular Invasion by Squamous Cell Carcinoma of the Oral CavitySuresh K. Mukherji1 2 3 4, David L. Isaacs1, Andrew Creager5, William Shockley2 3, Mark Weissler2 3 and Dianne Armao1Audio Available | Share

Objectives/Hypothesis: Positron emission tomography (PET) has shown promise for early detection and accurate staging of cancer patients. A limited number of studies suggest PET/computed tomography (CT) may improve these variables; however, no published study has specifically evaluated clinical outcomes with PET/CT for head and neck (HN) tumors. The current study evaluates the use, accuracy, and implications for patient management of PET/CT scans in patients with HN tumors. Study Design: Retrospective cohort outcomes study at a tertiary care center. Methods: The authors identified 795 consecutive PET/CT at our institution. A total of 113 were obtained for HN tumors; 97 were used in the final analysis. Accuracy, use, and implications for patient care management decisions were correlated with each PET/CT scan. Multiple regression analysis was performed. Results: Accuracy, sensitivity, and specificity were measured by comparing the PET/CT results at the primary tumor site, cervical node sites, and distant sites with either pathologic or definitive clinical diagnoses. PET/CT had an overall per scan accuracy of 72% and a per patient accuracy of 69%. When stratification for rationale of obtaining the scan was performed, accuracy was 80% for staging distant disease, 67% for primary tumor evaluation, 72% for evaluation for recurrence, and 60% for unknown primary tumor evaluation. Conclusions: PET/CT imaging is a promising tool for evaluating HN tumors; however, in clinical practice, the proper use of such technology is not well studied. In our study, PET/CT had an overall accuracy of 72% in evaluating HN tumors, and PET/CT had the most accuracy in the detection of distant metastasis.

Introduction: Despite improvements in automotive safety, motor vehicle collision (MVC)-related facial fractures remain common and represent preventable injuries. This study examines the changing characteristics of facial fractures treated at a regional, level I trauma center, from 2005 to 2010. Methods: We identified all patients with facial fractures admitted to our hospital, from 2005 to 2010, by querying the North Carolina Trauma Registry, using International Classification of Diseases, Ninth Revision codes. Prospectively collected data, sorted by year, were descriptively analyzed for demographics, referral patterns, etiology, anatomic location, and clinical outcomes. Results: Number of patients with facial fractures increased from 201 per year to 263 per year (total n = 1508). Although transport distances remained constant at ∼85 miles, standard deviation increased from 37 to 68 miles. Transport time increased from 87 to 119 minutes. Referrals came from 28 surrounding counties in 2005 and 43 counties in 2010. Regarding etiology, MVCs decreased from 40% to 27%, all-terrain vehicle crashes decreased from 6% to 2%, falls increased from 8% to 19%, and bicycle accidents increased from 3% to 6%. Regarding anatomic location, frontal sinus fractures increased from 8% to 37%, zygomaticomaxillary fractures increased from 9% to 18%, nasoethmoid fractures decreased from 12% to 6%, orbital floor fractures decreased from 6% to 3%, and mandible fractures decreased from 28% to 18%. Single-site fractures increased from 75% to 90%. Length of intensive care unit and hospital stay remained stable at 3 and 7 days, respectively. Conclusions: Despite a decrease in MVC-related facial fractures, the overall increase in facial fractures referred to our trauma center is due to a growing number of patient transfers from rural hospitals, where a paucity of qualified surgeons may exist.

Summary form only. An abstract of the above-titled article, taken from the 1963 IEEE International Convention (held March 25-28, New York, NY, USA), is presented.

There are many well-established principles and surgical techniques for nasal reconstruction. The purpose of this study is to describe contemporary reconstruction of nasal defects. The unique anatomic features of the nose make this a challenging task. Although obtaining an optimal esthetic result is always the goal of reconstruction, maintenance and restoration of nasal function are of equal importance.The first step of nasal reconstruction is a thoughtful analysis of the defect. The best surgical option will provide the patient with an excellent esthetic result and nasal function. Depending upon the extent of the defect as well as the anatomic site, a local flap, full-thickness skin graft, composite graft, or interpolated flap will provide the optimal result. The decision will depend on the surgeon's experience and expertise, as well as expectations and desires of the patient. Many cutaneous defects will require not only reconstruction of the defect, but also cartilage grafts to provide nasal contour and support. Most large or complex defects will require a paramedian forehead flap for reconstruction along with cartilaginous and/or bony support, as well as a lining flap.This study highlights recent advances in nasal reconstruction and novel modifications of well-accepted traditional techniques.

Abstract Purpose: We evaluated X-ray repair complementing defective repair in Chinese hamster cells 1 (XRCC1) protein in head and neck squamous cell carcinoma (HNSCC) patients in association with outcome. Experimental Design: XRCC1 protein expression was assessed by immunohistochemical (IHC) staining of pretreatment tissue samples in 138 consecutive HNSCC patients treated with surgery (n = 31), radiation (15), surgery and radiation (23), surgery and adjuvant chemoradiation (17), primary chemoradiation (51), and palliative measures (1). Results: Patients with high XRCC1 expression by IHC (n = 77) compared with patients with low XRCC1 expression (n = 60) had poorer median overall survival (OS; 41.0 months vs. OS not reached, P = 0.009) and poorer progression-free survival (28.0 months vs. 73.0 months, P = 0.031). This association was primarily due to patients who received chemoradiation (median OS of high- and low-XRCC1 expression patients, 35.5 months and not reached respectively, HR 3.48; 95% CI: 1.44–8.38; P = 0.006). In patients treated with nonchemoradiation modalities, there was no survival difference by XRCC1 expression. In multivariable analysis, high XRCC1 expression and p16INK4a-positive status were independently associated with survival in the overall study population (HR = 2.62; 95% CI: 1.52–4.52; P &amp;lt; 0.001 and HR = 0.21; 95% CI: 0.06–0.71; P = 0.012, respectively) and among chemoradiation patients (HR = 6.02; 95% CI: 2.36–15.37; P &amp;lt; 0.001 and HR = 0.26; 95% CI: 0.08–0.92, respectively; P = 0.037). Conclusions: In HNSCC, high XRCC1 protein expression is associated with poorer survival, particularly in patients receiving chemoradiation. Future validation of these findings may enable identification of HNSCC expressing patients who benefit from chemoradiation treatment. Clin Cancer Res; 17(20); 6542–52. ©2011 AACR.

Received 29 September 1967DOI:https://doi.org/10.1103/PhysRevLett.20.343©1968 American Physical Society

This article addresses the use of scar revision surgery as it relates to the use of Z-plasty, W-plasty, and geometric broken line closure. Each of these techniques is discussed in detail and the author provides perspectives regarding the indications, advantages, and limitations of each procedure. The surgeon should be experienced with each of these and apply these methods as appropriate. As with any technique, careful preoperative planning along with meticulous execution will lead to optimal results.

Application of the methodology of analysis of Shockley surface states confirms the existence of Wannier's Stark ladders of energy levels in finite crystals for wave functions that decay exponentially towards both edges of the crystal and shows that the perfectly regular energy intervals will be minutely disturbed by tunneling effects. If phonon scattering is neglected, coherent oscillations of electrons associated with specified energy bands are predicted.

Information on polymorphous low-grade adenocarcinoma (PLGA) consists primarily of case reports and small institutional series with varying recurrence rates. In this report, we describe our institutional experience and conduct a review of the literature to assess the overall incidence of PLGA among oral salivary gland tumors and determine recurrence rates.A retrospective case series and literature-based review was performed.Retrospective case series at an academic tertiary referral center. Review of clinical records and pathological analysis of tissue specimens from 20 patients treated for PLGA from July 1, 1990 to July 1, 2011. A literature-based review on PLGA was also performed.Twenty patients (mean age, 54 years; eight males) with PLGA based on pathologic diagnosis were included. The most common initial presentation was an asymptomatic mass (45%), and the most frequent site was the palate (60%). Our literature review identified 54 case reports, eight case series, and 17 large series. In total, 456 cases of PLGA were identified, with an overall recurrence rate of 19%. Half of the recurrences occurred by 36 months; however, recurrences were reported up to 24 years after initial resection.PLGA arises from minor salivary glands and is characteristically slow growing and indolent. Although these tumors may be histologically low-grade, our review highlights the high rates of recurrence of these tumors as well as the ability to metastasize to local lymph nodes and distant organs. The mainstay of treatment should be wide surgical excision with long-term oncologic follow-up.4.

Recently, the management of head and neck squamous cell carcinoma (HNSCC) has focused considerable attention on biomarkers, which may influence outcomes. Tests for human papilloma infection, including direct assessment of the virus as well as an associated tumour suppressor gene p16, are considered reproducible. Tumours from familial melanoma syndromes have suggested that nuclear localisation of p16 might have a further role in risk stratification. We hypothesised p16 staining that considered nuclear localisation might be informative for predicting outcomes in a broader set of HNSCC tumours not limited to the oropharynx, human papilloma virus (HPV) status or by smoking status.Patients treated for HNSCC from 2002 to 2006 at UNC (University of North Carolina at Chapel Hill) hospitals that had banked tissue available were eligible for this study. Tissue microarrays (TMA) were generated in triplicate. Immunohistochemical (IHC) staining for p16 was performed and scored separately for nuclear and cytoplasmic staining. Human papilloma virus staining was also carried out using monoclonal antibody E6H4. p16 expression, HPV status and other clinical features were correlated with progression-free (PFS) and overall survival (OS).A total of 135 patients had sufficient sample for this analysis. Median age at diagnosis was 57 years (range 20-82), with 68.9% males, 8.9% never smokers and 32.6% never drinkers. Three-year OS rate and PFS rate was 63.0% and 54.1%, respectively. Based on the p16 staining score, patients were divided into three groups: high nuclear, high cytoplasmic staining group (HN), low nuclear, low cytoplasmic staining group (LS) and high cytoplasmic, low nuclear staining group (HC). The HN and the LS groups had significantly better OS than the HC group with hazard ratios of 0.10 and 0.37, respectively, after controlling for other factors, including HPV status. These two groups also had significantly better PFS than the HC staining group. This finding was consistent for sites outside the oropharynx and did not require adjustment for smoking status.Different p16 protein localisation suggested different survival outcomes in a manner that does not require limiting the biomarker to the oropharynx and does not require assessment of smoking status.

Received 16 September 1963DOI:https://doi.org/10.1103/PhysRevLett.11.489©1963 American Physical Society

Background: Nasal septal perforations (NSPs) are notoriously difficult to fix and closure can paradoxically lead to worsening of symptoms, prompting numerous techniques for repair including temporoparietal fascia (TPF)–polydioxanone (PDS) plate interposition grafting. Objectives: To compare rates of NSP closure with TPF–PDS interposition grafting among a variety of institutions with diverse environmental influences and patient-specific factors. Methods: Retrospective review of patients undergoing TPF–PDS interposition grafting at seven different U.S. institutions over 5 years. Outcomes include closure rate, self-reported symptom improvement, change in Nasal Obstruction Symptomatic Evaluation (NOSE) score, and postoperative complications. Results: Sixty-two patients (39 female) with a mean age of 41.5 years were included. Most common perforation location was anterior (53%), and average size was 1.70 cm2. NSP closure with symptomatic improvement was achieved in 95% of participants. Postoperative NOSE scores decreased on average by 42 points. Residual crusting occurred in 29% of patients, independent of external factors. Conclusions: TPF–PDS interposition grafting is highly effective for NSP repair in a wide variety of settings, and NOSE scores correspond well with patient-reported outcomes.

Purpose Pretreatment CT volumetric measurement of the primary tumor has been shown to be a predictor of local control in patients with laryngeal carcinoma treated with radiation therapy (RT) alone. A direct association has been demonstrated between tumor volume of supraglottic squamous cell carcinoma (SGSCCA) and local control. However, the association between tumor volume of SGSCCA and local control has not been investigated in patients treated surgically. The purpose of this study was to determine the relationship between SGSCCA tumor volume and local control in patients treated surgically. Materials and Methods Primary site tumor volume was calculated from pretreatment CT studies in 37 laryngeal supraglottic carcinomas treated surgically. All patients had clinical follow-up for evidence of recurrent tumor along the surgical margins at the primary site for a minimum of 2 years after completion of treatment. Statistical analysis consisted of Mantel-Haenszel chi-square tests and Fisher's exact test. Results Overall local control rate was 92% (33 of 37). Tumor volume was significantly associated with local control (p <.05). Local control rate for tumors with volumes <16 cc was 94% (32 of 34) (p <.05). Conclusions Pretreatment CT volumetric analysis is useful for predicting local control in patients with SGSCCA carcinoma treated surgically. © 2000 John Wiley & Sons, Inc. Head Neck 22: 282–287, 2000.

Abstract This study was conducted to re‐examine the osteological anatomy of the orbit. Previous studies examined dried human skulls; this study looks at cadaveric specimens in a population that more closely resembles the population in the United States. Measurements were made of the bony orbit to define safe distances for surgical intervention and to identify distances to intraorbital fissures, canals, and foramina. Safe distances to the optic nerve were identified by subtracting 5 mm from the shortest measured specimen. The safe distances were as follows: medial quadrant, 29 mm; inferior quadrant, 39 mm; superior quadrant, 38 mm; and lateral quadrant, 36 mm. Staying close to the bony wall, not exceeding these parameters, and careful identification of anatomical structures should keep the surgeon from inadvertent damage to the intraorbital structures.

Background. Odontogenic neoplasms of predominately clear cells are unusual. They represent a diagnostic dilemma, and as a result, treatment strategies are diverse. Our goal is to present two new cases, summarize reported cases of clear cell odontogenic carcinoma (CCOC), assess potential risk factors for recurrence, and propose definitive surgical and therapeutic strategies. Methods. A literature search and analysis was performed. Regression models were used to predict risk factors for recurrence. Results. Forty-three cases of CCOC were reviewed, including two reported here. The overall rate of recurrent disease was 55%. Local recurrence rates were higher for curettage (80%) than for resection alone (43%). Age (p = .20), sex (p = .28), and tumor site (p = .50) did not predict risk for recurrence. Conclusions. CCOC is a potentially aggressive tumor with a tendency for recurrence. Treatment strategies should be directed toward wide surgical resection with confirmation of tumor-free margins. Lymph node dissection and adjuvant radiation therapy should be considered in selected cases. © 2005 Wiley Periodicals, Inc. Head Neck 27: XXX–XXX, 2005

Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans the biological, physical, and social sciences.

Objective Nanofiber‐supported, in vitro–generated cartilage may represent an optimal starting material for the development of a cartilage implant for use in microtia reconstruction. To do so, the authors aim to first characterize the molecular composition of endogenous auricular cartilage and determine if human umbilical cord mesenchymal stem cells (hUCMSCs) can be differentiated into cartilage in vitro. Study Design Prospective, controlled. Setting Academic research laboratory. Subjects and Methods Human ear cartilage from normal adults, pediatric patients with microtia, and pediatric patients with preauricular appendages (n = 2) was analyzed for collagens I, II, and X and elastin expression. In parallel, hUCMSCs were cultured on either polycaprolactone (PCL) or D, L‐lactide‐co‐glycolic acid (PLGA) nanofiber scaffolds for 21 days under chondrogenic conditions. Cells were harvested for histologic, biochemical, and quantitative polymerase chain reaction analysis. Control cells were grown under both chondrogenic and nonchondrogenic conditions in the absence of nanofiber scaffolds. Results Histological analysis of human ear cartilage revealed similar levels and distribution of collagens I and X and elastin. Collagen II was not highly expressed in the microtia samples. hUCMSC cultures stained positively for glycosaminosglycans (GAG) and sulfated proteoglycans. Compared to control cells, hUCMSCs grown on PLGA nanofiber scaffolds had a higher differentiation index ( P ≤. 012) and higher levels of collagen X mRNA expression ( P ≤. 006). Conclusion These data provide information regarding the composition of endogenous ear cartilage and suggest that hUCMSCs grown on PLGA nanofiber scaffolds may represent an optimal starting material for the development of a cartilage implant for use in microtia reconstruction.

Collapse or compromise of the internal nasal valve (INV) results in symptomatic nasal obstruction; thus, various surgical maneuvers are designed to support the INV. To determine the effect on nasal airflow after various surgical techniques focused at the level of the INV and lateral nasal sidewall. A fresh cadaver head was obtained and underwent suture and cartilage graft techniques directed at the level of the INV using an external approach. Preoperative and postoperative digital nasal models were created from the high-resolution, fine-cut, computed tomographic imaging after each intervention. Isolating the interventions to the level of the INV, we used computational fluid dynamic techniques to calculate nasal resistance, nasal airflow, and nasal airflow partitioning for each intervention. Suture and cartilage graft techniques. Nasal airflow, nasal resistance, and partitioning of airflow. Using the soft-tissue elevation model as baseline, computational fluid dynamic analysis predicted that most of the suture and cartilage graft techniques directed toward the nasal valve improved nasal airflow and partitioning while reducing nasal resistance. Specifically, medial and modified flare suture techniques alone improved nasal airflow by 16.9% and 15.1%, respectively. The combination of spreader grafts and modified flare suture improved nasal airflow by 13.2%, whereas spreader grafts alone only improved airflow by 5.9%. The largest improvements in bilateral nasal resistance were achieved using the medial and modified flare sutures, outperforming the combination of spreader grafts and modified flare suture. Techniques directed at supporting the INV have tremendous value in the treatment of nasal obstruction. The use of flare sutures alone can address dynamic valve collapse or upper lateral cartilage incompetence without gross disruption of the nasal architecture. Using computational fluid dynamic techniques, this study suggests that flare sutures alone may improve flow and reduce resistance when placed medially, surpassing spreader grafts alone or in combination with flare sutures. The longevity of these maneuvers can only be assessed in the clinical setting. Studies in additional specimens and clinical correlation in human subjects deserve further attention and investigation. NA.