Search

Sebaceous differentiation in salivary gland tissue is common. However, sebaceous neoplasms within the salivary glands are rare. We present the case of a sebaceous lymphadenoma with unusual features, arising in the parotid gland of a 60-year-old male. To the best of our knowledge, this is the first report of the ultrasound and MRI characteristics of this rare tumour. The difficulties encountered in reaching a definitive diagnosis both radiologically and histologically are described.

Cet article examine les modèles culturels du riz malgache (vary gasy) et leurs implications dans le développement agricole dans l’est de Madagascar. Les données ont été collectées durant deux saisons, en 2003 avec les marchands de riz et les agronomes à Toamasina, et en 2004 avec les agriculteurs à Andasibe. La subsistance rurale des agriculteurs et marchands de riz de l’est de Madagascar assigne aux types de riz des significations qui incluent des croyances selon lesquelles certaines variétés sont meilleures pour la santé et produisent de meilleurs rendements que d’autres. Les marchands définissent les types de riz principalement par le rendement en grains à l’hectare ainsi que par le mode de culture (sec ou humide), la saison de croissance et la durée de la période de récolte. Les agronomes ignorent les préférences des marchands et des agriculteurs, les considérant comme sans réel lien avec les rendements, qui sont, selon eux, le seul critère pour évaluer le succès agricole. Le développement agricole à Madagascar ne peut se fonder sur un seul ensemble de connaissances faisant autorité sur les types de riz, mais doit tenir compte des points de vue de tous les participants. This paper examines folk models of Malagasy rice (vary gasy) and their implications for agricultural development in eastern Madagascar. Data on rice models were collected during two field seasons, in 2003 with rice merchants and agricultural scientists in Toamasina and in 2004 with rural farmers in Andasibe. Rural subsistence farmers and rice merchants in eastern Madagascar ascribe meanings to rice types, which include beliefs that certain types are healthier to consume and produce higher yields than other types. Rice merchants define rice types by characteristics of the rice kernel while farmers define rice types by characteristics of the rice plants. Agricultural scientists define rice types primarily by the grain yield per hectare as well as by farming method (dry and wet), growing season and length of time to harvest. Agricultural scientists disregard rice preferences of merchants and farmers as being inconsequential to rice yields, which are believed to be the primary metric of farming success. Agricultural development in Madagascar cannot rely upon one set of authoritative knowledge of rice types, but must take into account all the participants’ beliefs.

Summary Six videotapes covering 1406 administrations of items from the Griffiths Scales of Mental Development were made, and each one was shown to a different panel of 9 or 10 observers. Each person independently scored the items and made comments on administration and scoring. Reasons for disagreements among scorers were considered in terms of these comments and the characteristics of individuals and groups participating. Disagreement was particularly high for items from the Baby Scales. This was at least partly due to use of mothers' reports. Mothers' reports were found to present a particular problem when elicited on occasions for which they are not recommended by the manual. Across all ages disagreement was related to difficulties with both administrative and scoring criteria. The present study was designed to be sensitive to a range of sources of unreliability and the findings may have relevance for other infant assessment procedures.

In a companion paper the theoretical basis for the Canadian Atmospheric Environment Service oil spill behaviour model was discussed along with its evaluation, in non‐real time, using data collected from field experiments and a real spill. This paper deals with the use of the model in real time to provide guidance in support of the emergency created by an oil spill in the Canadian Beaufort Sea. The spill of about 2440 barrels of diesel oil occurred in September 1985, the result of storm damage to an artificial island used for hydrocarbon exploration. Model simulations were carried out for two time periods while the spill was being tracked. These simulations identified the marked shifts in the direction of movement of the spill. While the predictive skills for the two time periods varied, with re‐initialization the final observed slick location was predicted to within 2 km. This model prediction was used by the regulatory authorities as guidance information in locating the slick when it could not b...

Summary The effects of different elements on the A4 and A3 transformation points of iron are described, and a discussion given of the way in which this leads to different types of equilibrium diagram. The importance of the relative sizes of the constituent atoms in determining the structure of the alloys is emphasized, and it is shown how some of the structural characteristics are related to the relative positions of solvent and solute in the Periodic Table, although quantitative theory is lacking. The useful properties of steels generally involve structures which are not those of the equilibrium state, and some of the transformations concerned are briefly outlined.

Measurements have been made of the lattice spacings of pure ruthenium, and of dilute solid solutions of zirconium, niobium, molybdenum, rhodium, and palladium in ruthenium. In all cases the c lattice spacings and axial ratios of the c.p. hexagonal cell are increased by the formation of a solid solution, and at equiatomic percentages of solute the increases are in the order Rh

The use of the concepts of favourable and unfavourable size factor in predicting solid solubilities in metallic systems is discussed. The original concept of Hume-Rothery, Mabbott and Channel-Evans involved the use of atomic diameters which were defined as the closest distances of approach of atoms in the crystals of the elements. Atomic diameters defined in this way give a much better correlation with solid solubilities than do the Goldschmidt atomic diameters and a slightly better correlation than the Pauling single bond metallic radii. Recent suggestions that atomic diameters should be replaced by atomic volumes are reviewed and it is shown that the atomic volumes do not correlate well with the solid solubilities in alloy systems. In spite of the different crystal structures involved, the atomic volumes in the sequences Cu→ Zn → Ga→ Ge, Ag → Cd → In and Au → Hg → Tl show an almost exactly linear increase with atomic number.

Synopsis Copper is able to dissolve both zinc and aluminium, and in the binary systems Cu-Zn and Cu-Al there are typical primary (α) face-centred-cubic solid solutions, and body-centred-cubic (β) phases, which are 3/2 electron compounds. In these and other similar alloys of copper, the equilibrium between the α and β phases is determined mainly by the electron concentration, provided that the size-factors are favourable and the electrochemical factors are small. The present paper describes an experimental investigation of the effect of manganese, iron, cobalt and nickel on the α/β equilibrium in Cu-Zn and Cu-Al alloys at 672° C. For this purpose the isothermal sections of the ternary systems in the regions concerned have been determined by the method of annealing and microscopical examination. If it is assumed that the α/α + β and α+β/β solubility curves in the ternary isothermal sections are lines of constant electron concentration, the results show that, when present in small quantities, Ni, Co, Fe and ...

The equilibrium diagram of the system gold-gallium has been determined by a combination of thermal analysis, and microscopical and X-ray metallography. The work has led to the discovery of a close-packed α-phase, with ABAC… stacking sequence, lying outside the Au-rich α-solid solution. The small β-phase region claimed by Weibke and Hesse has been shown not to exist, whilst three new phases have been discovered in the intermediate region.

The equilibrium diagram of the system molybdenum-cobalt has been investigated by a combination of thermal analysis, microscopy, and X-ray techniques, and the crystal structures and lattice spacings of the different phases have been determined. Molybdenum can dissolve about 11.5 at. % cobalt at 1620°C, the temperature of the peritectic reaction αMo + Liq /agσ. Cobalt dissolves about 18 at. % molybdenum at 1335°C, the temperature of the (βCo + e) eutectic. The σ-phase extends over a slight range of composition in the region 37–38 at. % cobalt, and decomposes eutectoidally at 1250°C to form (αMo + e). The e-phase lies in the region (50–55) at. % cobalt. The crystal structure is of the D85 type, and the lattice constants were determined as a = 4.666 ± 0.005 kX, c = 25.6 ± 0.02 kX. At high temperatures, the e-phase is in equilibrium with β-Co, but at1200°C a new phase, denoted θ, is formed peritectoidally, and decomposes at 1025°C; the θ-phase gives a diffraction pattern whose lines can be fitted to a hexagonal cell with a = 2.5921 ± 0.0005 kX, and ca = 1.6218. The kappa, or Co3Mo phase is formed peritectoidally at 1025°C, and crystallises in the Do19 type of structure with a = 5.12 kX, ca = 0.803; this may be regarded as a superlattice of the close-packed hexagonal structure, with a doubled a spacing and a halved axial ratio. The results are discussed, and confirm the tendency of the σ-phases to occur at an electron concentration of 7.0–7.3.

The equilibrium diagram of the system niobium-nickel has been determined by a combination of thermal analysis, microscopical metallography, and X-ray techniques. Nickel is able to dissolve up to 12.5 at. % Nb at high temperatures, whilst niobium dissolves only 4.5 at. % of Ni. The system contains an intermediate phase (β) Ni3Nb with the Cu3Ti type of structure, which gives rise to a maximum on the liquidus curve at 1402°C. There is also a γ-phase of composition limits 50–54 atomic % Nb, formed by a peritectic reaction at 1295°C.

The Engel-Brewer theory of metal and alloy crystal structures is examined critically. The conclusion reached is that, for pure metals, the correlation between electron configuration and crystal structures exist only for the elements of Groups IIIA–VIA. The application of the theory to alloy structures is shown to involve many inconsistencies.

The equilibrium diagram of the system bismuth-palladium has been studied in the region 0–65 at.-% Pd by thermal analysis and microscopical methods. The freezing point of bismuth is depressed by the addition of palladium and sinks to a eutectic at 5.83 at.-% Pd and 256°C. The liquidus then rises to 485.4°C, at which temperature the compound “Bi 2 Pd” melts without change of composition. The compound BiPd gives rise to a pronounced maximum in the liquidus curve at 618°C, and there is a palladium-rich eutectic at 577°C. At low temperatures the composition of the “Bi 2 Pd” phase is about 34 at.-% Pd. It undergoes a transformation at 380°C, in contrast to the earlier work of Zhuravlev And Zhdanov , according to whom the transformation took place at 200°C. There is a remarkable resemblance between the equilibrium diagrams of the systems Pd-Sb and Pd-Bi. Both give rise to compounds of the type PdX 2 , the melting points of the Sb-compounds being systematically higher.

The equilibrium diagram of the system molybdenum-nickel has been determined by a combination of thermal, microscopical, and X-ray methods. The system contains an intermediate γ-phase whose composition limits include the value corresponding to MoNi3; this phase has an orthorhombic structure. In contradiction to previous work, the composition of the intermediate δ-phase does not include the equiatomic ratio, and has a slight composition range centred at about 47 at.% Ni. The intermediate β-phase has a composition in the region of 80.5–81 at.% Ni, and does not include the exact ratio MoNi4; the structure is tetragonal and may be regarded as derived from a MoNi4 superlattice of the f.c.c. Ni solid solution. The lattice spacings of the terminal solid solutions have been determined. The equilibrium diagram of the systems Mo-Co and Mo-Ni show many similarities, and these are discussed.

The limits of composition of the face-centred cubic solid solutions in binary alloys of the elements V, Cr, Fe, Co and Ni are discussed. The term group number (G.N.) is used to denote the position of the transition metal in the First Long Period (is. G.N.=4 for Ti). It is shown that if the binary equilibrium diagrams ere drawn in terms of the average G.N. values of the alloy, and if manganese is omitted as an abnormal element, the face-centred cubic solid solutions are stable from G.N. 10 (pure Ni) to a value of about 7.7, in cases where the aim-factors are favourable. The limits of the face-centred cubic solid solution occurs at an approximately constant G.N. value, in very much the same way that the limits of the α-solid solutions in copper and silver alloys occur at an approximately constant electron: atom ratio. It is ah shown that, when plotted in terms of average G.N. value, the liquidus and solidus curves for the γ-phases in the systems Fe-Co and Fe-Ni am almost superposed, this behaviour ...

Previous work suggested that the compound Bi4Rh existed in three modifications with transformation temperatures α/β 310°C and β/γ 390°C. Diffraction films taken in a high temperature X-ray camera show that only one structure exists between room temperature and 460°C, the temperature of the Bi4Rh ± Bi2Rh + Liq. peritectic horizontal. The crystal structure of this one modification is body-centred cubic, space group No. 230, lattice parameter 14.9274 ± 0.0002 A at 20°C, and is identical with the α-Bi4Rh modification of previous investigators. The liquidus curve of Bi-rich BiRh alloys has been redetermined and the most probable equilibrium diagram is reproduced.

The equilibrium diagram of the system Au-Cd has been investigated by thermal, microscopical, and X-ray diffraction methods. At high temperatures the phases present are 1. (1) the α solid solution of cadmium in gold, 2. (2) the α 2 phase which is of variable composition with close-packed hexagonal structure, and 3. (3) the β′ body-centred cubic phase which remains highly ordered at a few degrees below the melting point. No evidence was found for the existence of the α 3 phase claimed by Owen et al . or of the α″ phase postulated by Bystrom and Almin. On the cadmium-rich side, the α 2 phase has a normal close-packed hexagonal structure but, in the range 27–34 at. % Cd, highly faulted structures are observed, and a possible cause of this is suggested in terms of the curves of densities of electronic states. In the region of 25 at. % Cd, at low temperatures, a face-centred tetragonal phase is formed, and also a new face-centred cubic phase which has not been described before.

The equilibrium relations in the system bismuth-rhodium are examined. In agreement with the authors' previous work, no evidence is found for the existence of more than one modification of the compound Bi 4 Rh. Attempts to prepare further modifications by cooling from above the liquidus (as was done by Russian investigators) were unsuccessful. No evidence was found for the existence of the compound Bi 3 Rh claimed by Zhdanov et al . The compound Bi 2 Rh is shown to exist in two modifications, with a transition temperature of 425°C. The structure of the compound BiRh was confirmed as being of the NiAs type. The lattice spacings were measured up to 970°C, and kinks in the curves of c and c / a against temperature were found to exist at 800°C, and a less pronounced kink occurred in the curve for the a spacings, whilst the curve for temperature versus mean volume per atom was smooth.

The relative advantages of the X-ray and classical methods for the determination of phase boundaries in metallurgical equilibrium diagrams are discussed. For ordinary equilibrium diagram work at the higher temperatures, the classical methods appear more satisfactory and reliable, but the X-ray methods become increasingly valuable at the lower temperatures, provided that sufficiently long periods of annealing are used. The X-ray methods are of the greatest value in alloys in which superlattice transformations are involved. The difficulties of determining the composition of the filings comprising the X-ray specimen are emphasized, and also the dangers likely to arise from decomposition of filings during quenching. The general conclusion drawn is that the X-ray and classical methods should be used in conjunction, and that it is a mistake to rely on X-ray methods alone.

The equilibrium diagram of the system molybdenum-ruthenium has been determined for temperatures above 1450°C. Molybdenum dissolves about 30.5 at.% Ru at high temperatures and the solubility diminishes quickly as the temperature falls. Ruthenium dissolves 51 at.% Mo at high temperatures and the solubility diminishes slowly with falling temperature. The sigma phase exists in the region of 37.0 ± 1 at.% Ru and is formed by a peritectoid reaction slightly below the 1945°C eutectic horizontal between the solid solutions in molybdenum and ruthenium. The lattice spacings of the different phases have been measured, and the V.P. hardness numbers were determined for alloys in the “as-sintered” state prepared by powder methods.

The composition limits of the different crystal structures found in the alloys of Transition Elements of Groups VA to VIIIC are discussed. The alloys of these elements give rise to phases with crystal structures of the [sgrave], c.p. hexagonal, αMn, and βW types. The composition limits of these are often related to the Group Numbers of the constituent elements. If the equilibrium diagrams are drawn with the element of lower Group Number on the left, passage across the diagram from left to right results in the occurrence of different phases in the following order: b.c. cube→βW→[sgrave]→αMn →c.p.hex. →f.c. cube. In all systems one or more of the above phases is absent, but the characteristic order is retained. In the alloys of elements of Group VIIIC with the elements in the middle of the transition series, there is a general tendency for the primary solid solution in the element of Group VIIIC to be greater than that in the element of the earlier Group, and an explanstion of this is advanced.

The equilibrium diagram of the system niobium-cobalt has been determined by a combination of thermal analysis, microscopical metallography, and X-ray diffraction techniques. The freezing point of cobalt is lowered markedly on addition of niobium, and the liquidus curves sink to a eutectic point at 13.9 at.% Nb and 1237°C. The constituents of the eutectic are a solid solution of Nb in Co (5.5 at.% Nb), and an NbCo 3 -phase whose structure is based on that of the Laves C36 type. This decomposes peritectically at 1247°C to form liquid plus a “Co 2 Nb” phase whose composition extends from 27 to 33.3 at.% Nb and whose structure is of the Laves C 15 type. This gives rise to a maximum on the liquidus curve, and forms a eutectic with a phase denoted μ which exists over the range 50.5–52.7 at.% Nb, and whose structure is that of the W 6 Fe 7 type. The μ-phase gives rise to a flat maximum on the liquidus curve, surrounded by (NbCo 3 + μ) and (μ + Nb solid solution) eutectics. The maximum solubility of cobalt in solid niobium is 3.1 at.% at the 1374°C eutectic temperature. The significance of these results is discussed.

The complete constitutional diagram of the system Au-Hg has been determined by thermal analysis and X-ray diffraction methods, supplemented by microscopical work on gold-rich alloys. Much of the work was carried out in sealed tubes, and the pressure was an undetermined variable. The gold-rich alloys contain two intermediate phases denoted α' and ζ. The α'-phase is formed by a peritectic reaction at 419°C; it has a hexagonal crystal structure with lattice parameters a = 8.736 A and c = 9.577 A , and the unit cell contains 36 atoms. The ζ-phase is formed peritectically at 388°C. A phase Au2Hg was observed at temperatures below 122°C, and this appears to be of fixed composition; it is hexagonal with lattice parameters a = 13.98 A and c = 17.20 A . In contrast to the conclusions of some earlier workers, no evidence was found for the existence of any intermediate phase richer in mercury than Au2Hg.

Two X-ray cameras are described which can be used to very high temperatures. One of these is a Debye-Scherrer camera after the model of Westgren 1 in which electric current for heating passes through the specimen itself and this camera has been used up to 3100°C. In the application of this camera to Cr, Rh, Ru and W, only the room temperature modifications were detected, while for Hf photographs were obtained of the high temperature b.c.c. modification. The other camera is of the symmetrical parafocusing type with a refractory metal heater surrounding the specimen. The specimen, which is in the form of a block of the material under study, has a small hole drilled in it which forms effectively a black body cavity for temperature measurement. This camera has been used to determine accurately the temperature variation of the lattice parameter of Mo up to 1733°C.

The equilibrium diagrams of the later transition metals of the Second and Third Long Periods are examined systematically. It is shown that the body-centred cubic, close-packed hexagonal, and face-centred cubic phases have composition ranges whose boundaries appear to be controlled mainly by the Average Group Numbers of the alloys. Group Numbers of 6, 7, 8, 9, and 10 are allotted to the elements of Groups VIA, VIIA, VIIIA, B, and C respectively, so that an equiatomic alloy of Mo and Ru has an AGN value of 7.0. Relations with the elements of the first transition series are discussed.

It is proposed that the change in crystal structure on alloying the noble metals with elements of the B sub-groups (e.g. copper-zinc) is due to the Fermi surface touching the cube faces of the Brilloum zone of the face-centered cubic structure rather than the octahedral faces which are already touched in the pure metals. A reasonable band structure for copper is consistant with this suggestion.

(1954). The transition metals and their alloys. Advances in Physics: Vol. 3, No. 10, pp. 149-242.

ABS>The fact that Yb and Th exhibit very limited mutual solid and liquid miscibilities was interpreted in terms of a rule involving an electronegativity vs radius (for coordination number 12) graph. In this rule, an ellipse is drawn around one element on the graph, and the elements within the ellipse are predicted to form extensive solid solutions with this element, while the other elements lying outside the ellipse have limited solubilities. Numerous exceptions to the rule are given with Au, Ag, Cu, and Mg as solvent, and the justification of the rule is doubtful. Some of the reasons for the exceptions are discussed. It is concluded that an extreme difference in electronegativity (e.g., Au-Mg, AuIn, Ag-Li) does not preclude the formation of extensive solid solutions. (D.L.C.)

As a preliminary to the revision of the Griffiths scales, 79 examiners throughout Britain tested 447 infants under the age of 2 years during 1978-1982. Compared with the original standardization sample of 1947-1951, the 1980 sample mean general quotient (GQ) was significantly higher, even after adjustments had been made for a slightly skewed social class distribution. Nor did regional differences between samples account for the GQ differences. Unreliable items were not significantly more common among those where the median age at passing had changed most. Various technical difficulties in representing differences between samples were encountered and dealt with. A population's overall results may be given in terms of mean score increase per month, median age advance in weeks or months, e.g. per year, and increase in general developmental quotient. Findings of differences between populations in age at passing individual items can be given as advances in median age, but are better expressed as ratios of the median ages of the two samples in order to deal with the differences in the chronological age for which items are designed. Only then can items be compared for amount of change. In terms of score and mental age advances the second year appears more changed than the first, but in terms of GQ the reverse is true. The locomotor scale mean differs more than other scales from the original norms for both years of infancy, while the personal-social scale differs more in the first year. Taking the most cautious estimate of differences from the data available on both samples, at least 160 items are now passed earlier than in the 1950 sample and the ratio of 1950 to 1980 ages is greater than 110 for 83 of those. Further study of the Griffiths scales items, in relation to one another and to cultural factors, seems feasible on the basis of steps illustrated in this paper.