bluuebunny/crossref_metadata_2025 huggingface dataset:
Metallic barrelane: crystal structure, physical properties and bonding analysis of La16Al13
Authors: Niewa Rainer , Kirchner Martin , Zhang Hui , Schnelle Walter , Grin Yuri
Published: February 2005

Single crystals of the new intermetallic compound La16Al13 were obtained by thermal treatment of (La3O)Al in sealed Ta ampoules at 973 K, powder material for physical properties measurements from melt beads of appropriate composition at 773 K, well below the peritectic temperature of 978 K of the decomposition into LaAl and liquid. La16Al13 crystallizes hexagonal (space group P-62m, a = 918.3(2) pm, c = 1123.8(3) pm, R
gt(F) = 0.0293, R
all(F) = 0.0299, wR(F
2) = 0.0621) with one formula unit per unit cell. The crystal structure can be described as built from layers of face-sharing Edshammar polyhedra (AlLa2La9/2)2 alternating with layers of barrelane-like Al11 cages linked by La. La16Al13 is a Pauli-paramagnet with metallic electrical resistivity. Electron localization function calculation reveals covalent interactions within the Al11 cages. The resulting large number of the ‘free’ charge carriers explains the metal-like transport and magnetic properties in good agreement with the experiments and electronic band-structure calculation.
Structural phase transition of CeAuGe at high pressure
Authors: Brouskov Valeri , Hanfland Michael , Pöttgen Rainer , Schwarz Ulrich
Published: February 2005

Structural properties of the ternary intermetallic compound CeAuGe were investigated at hydrostatic pressures up to 15 GPa with high-resolution angle dispersive X-ray powder diffraction using synchrotron radiation and the diamond anvil cell technique. At 8.7(7) GPa a first order phase transition is observed from a hexagonal NdPtSb-type arrangement into an orthorhombic high-pressure modification with a TiNiSi-type crystal structure. The transformation is associated with a 3% shortening of the lattice parameter perpendicular to the puckered layers [AuGe]n and an elongation of one of the lattice parameters within the plane of the layers. The changes of interatomic distances are more pronounced than the metrical alterations and indicate that a transition from layer-type poly anions into a 3D network [AuGe]n is associated with the structural transformation.
Incommensurately modulated CeSi1.82
Authors: Leisegang Tilmann , Meyer Dirk C. , Doert Thomas , Zahn Gernot , Weißbach Torsten , Souptel Dmitri , Behr Günter , Paufler Peter
Published: February 2005

An incommensurately modulated structure of CeSi1.82 as determined by single-crystal X-ray diffraction at room temperature is reported. The observed satellite reflections reduce the orthorhombic symmetry of the X-ray pattern to a monoclinic one. This suggests the description of the modulated structure in the monoclinic superspace group I2/b(αβ0)00. The modulation wave vector was determined to q = 0.410(1) · a* + 0.610(1) · b*. The refinement was done using harmonic modulation functions for the displacement and the occupation probability of the atoms, the quality parameters converged to R
obs = 3.33% (R
obs = 2.56% for the main reflections, R
obs = 8.88% for the 1st order satellite reflections and R
obs = 33.06% for the 2nd order satellite reflections). The origin of the observed satellite reflections is attributed to a modulation of the partly occupied Si site caused by composition changes within the crystal.
Crystal structures of M2[B10H10] (M = Na, K, Rb) via real-space simulated annealing powder techniques
Authors: Hofmann K. , Albert Barbara
Published: February 2005

Alkali metal decahydro-closo-decaborates M2[B10H10] (M = Na, Rb, Cs) were synthesised by ion-exchange and characterised via infrared and 11B-NMR spectroscopy. The crystal structures of Na2[B10H10], K2[B10H10], and Rb2[B10H10] were determined from X-ray powder diffraction data using real-space techniques. The compounds crystallise in the monoclinic space group P21/n (no. 14) with the lattice constants: Na2[B10H10]: a = 1028.28(6) pm, b = 1302.18(5) pm, c = 667.34(3) pm, β = 93.754(3)°; K2[B10H10]: a = 1285.54(8) pm, b = 1117.84(7) pm, c = 682.27(4) pm, β = 93.357(3)°; Rb2[B10H10]: a = 1320.04(7) pm, b = 1136.88(6) pm, c = 704.23(4) pm, β = 94.158(3)°. The hydroborate anions are arranged almost hexa gonally with alkali metal cat ions in the tetrahedral interstices.
Solvothermal synthesis, phase transition and crystal structure of β- and γ-CuPb3Br7
Authors: Oldag Thorsten , Keller Hans-Lothar
Published: February 2005

Single crystals of CuPb3Br7 were solvothermally synthesized starting with CuBr and PbBr2 in diethylene glycol at a temperature of 453 K. Two reversible phase transitions were observed with the DSC method at temperatures of 156 K and 433 K. The crystal structures of the low and medium temperature modifications were determined with single crystal X-ray diffraction method. Both modifications can be derived from the Sr7Pt3 type structure and can be differentiated by minor atomic displacements and partial occupation of the additional copper positions.
[Ba2(C2H6O2)4][Ge2(C2H4O2)6] · 2.5 C2H6O2 – an ethanediolato complex of germanium. Synthesis, thermal decomposition and crystal structure
Authors: Jäger Lothar , Lorenz Volker , Wagner Christoph , Müller Thomas , Abicht Hans-Peter
Published: February 2005

[Ba2(C2H6O2)4][Ge2(C2H4O2)6] · 2.5 C2H6O2 (3a) is isolated from the reaction of GeO2 · aq with Ba(OH)2 · 8 H2O in glycol (1,2-ethanediol). 3a crystallizes in the space group P-1 with a = 10.324(2) Å, b = 13.932(3) Å, c = 15.800(3) Å, α = 102.86(2)°, β = 91.33°, γ = 109,47° and V = 2077.2(7) Å3. With increasing temperature 3a looses glycol and forms step by step [Ba(C2H6O2)2][Ge(C2H4O2)3] (3b), Ba[Ge(C2H4O2)3] (3c) and finally hexagonal BaGeO3 (4).
Synthesis and crystal structure of {[Li(NH3)4]2[18-crown-6]}[Li(NH3)4]2(Sn3
ph
6)2 · 4 NH3
Authors: Wiesler Katharina , Korber Nikolaus
Published: February 2005

{[Li(NH3)4]2[18-crown-6]}[Li(NH3)4]2(Sn3
ph
6)2 · 4 NH3 was prepared by reacting diphenyltin dichloride with lithium and 18-crown-6 in liquid ammonia. The crystal structure was obtained from low temperature single crystal X-ray data (P21/a, Z = 2, a = 18.483(5) Å, b = 13.240(2) Å, c = 22.919(5) Å; β = 103.65(3)°). The structure is built from previously unknown catena-hexaphenyltristannandiide anions, Sn3
ph
6, isolated tetraamminelithium complexes, and novel {[Li(NH3)4]2[18-crown-6]}2+ cations. In the latter divalent cation, two tetraamminelithium complexes coordinate to both sides of the crown ether via hydrogen bonds.
Nd(NH2SO3)(SO4) · 1.5 H2O: a non-centrosymmetric amidosulfate-sulfate of neodymium
Authors: Wickleder Mathias S.
Published: February 2005

The thermal decomposition of Nd(NH2SO3)3 · 2 H2O in a closed tube leads to violet single crystals of Nd(NH2SO3)(SO4) · 1.5 H2O. The compound crystallizes with the space group P1 (Z = 2, a = 689.2, b = 691.4, c = 962.0 pm, α = 109.64, β = 97.00, γ = 109.62°). The triclinic unit cell can be transformed into the respective bodycentered setting I1 (Z = 2, a = 977.9, b = 795.6, c = 1113.0 pm, α = 90.69, β = 115.06, γ = 88.98°) leading to a nearly monoclinic unit cell for the compound. In the crystal structure of Nd(NH2SO3)(SO4) · 1.5 H2O two Nd3+ ions are present. Nd(1)3+ is coordinated by four NH2SO3
– and two SO4
2– ions, and one H2O molecule. Owing to the chelating attack of the sulfate groups, the CN is nine. Nd(2)3+ is surrounded by four monodentate SO4
2– and two NH2SO3
– groups. Two H2O ligands fill up the coordination sphere and lead to a CN of eight. The linkage of the polyhedra leads to a three-dimensional network.
Synthesis of InxGa1–xN solid solutions
Authors: Kinski Isabel , Maurer Florian , Winkler Holger , Riedel Ralf
Published: February 2005

For the growth of group-III nitride thin films as well as GaN and AlN bulk phases precursors are widely used. Here, we introduce bulk phases of pure GaN, InN and solid solutions of InxGa1–xN synthesized by pyrolysis of molecular precursors in ammonia atmosphere. The dimeric [M(NMe2)3]2 (M = Al, Ga) is an oftentimes discussed precursor for conversion into group-III nitrides, while the other here presented gallium and indium amide derivatives have not been reported as appropriate precursors in literature so far. The given molecular structure of the precursors lead to a homogeneous distribution of Gallium and Indium on the cation positions in the solid solutions. GaN and InN and their solid solutions crystallizing in the wurtzite structure type follow Vegard’s law and therefore the lattice constant a
0 gives a hint about the degree of cations substitution in the structure. For the investigations of the synthesized bulk phases XRD, SEM and TEM coupled with EDX were used.
Chemical analyses and X-ray diffraction investigations of human hydroxyapatite minerals from aortic valve stenoses
Authors: Stork Ludwig , Müller Paul , Dronskowski Richard , Ortlepp Jan R.
Published: February 2005

A total of 23 solid, mineral-like samples from calcified aortic valves of human origin have been investigated by means of classic analytical techniques (atomic absorption spectroscopy) and powder X-ray diffraction methods (Rietveld approach). The calcification goes back to hexagonal Ca-deficient hydroxyapatite, and there is a large variance in absolute hydroxyapatite contents as well as in crystalline qualities. The source of the calcium deficiency has been traced back to the 4f calcium site of the crystal structure in P63/m, and the calcium loss is compensated by hydroxy group deficiencies. Despite no correlation between analytically and diffractionally determined calcium contents, the crystallinities of the samples and the sharpnesses of their Bragg peaks seem to be related with the sub-occupancy of the 4f calcium site.
M4,667Ch[SiO4]3 (M = Nd, Sm; Ch = O, S): structural comparison of two apatite-type lanthanoid chalcogenide ortho-oxosilicates
Authors: Hartenbach Ingo , Schleid Thomas
Published: February 2005

The lanthanoid chalcogenide ortho-oxosilicates M4.667Ch[SiO4]3 (M = Nd, Sm; Ch = O, S) with apatite-type crystal structure have been synthesized by the reaction of either M2O3 and SiO2 or M2O3, M, S and SiO2 using CsCl as flux in evacuated silica tubes at 850 °C for 7d. The title compounds crystallize hexagonally in the space group P63
/m with two formula units per unit cell. Their crystal structure contains two crystallographically independent lanthanoid cations, of which (M1) is surrounded by nine O ligands in the shape of a tricapped trigonal prism. Additionally, this site is only occupied by 81–84% to assure that the composition is electroneutral. The (M2) cations have an environment of seven O anions in the case of M4.667O[SiO4]3, which form a pentagonal bipyramid. Considering M4.667S[SiO4]3 this polyhedron changes, when one of the apical oxide particles is substituted by two sulfide ligands which then form a “two-legged” pentagonal bipyramid. Both the non-silicon bonded oxygen in the oxide derivative and the sulfur in the sulfide homologue are situated in a channel along [001]. While oxygen prefers a trigonal planar cationic coordination at the Wyckoff position 2a (CN = 3), the sulfur represents the centre of a trigonal antiprism at the Wyckoff position 2b (CN = 6).
On the crystal structure of a new modification of 2-amino-4,6-dichloro-1,3,5-triazine
Authors: Glaser Jochen , Tragl Sonja , Meyer Hans-Jürgen
Published: February 2005

The sublimation of 2-amino-4,6-dichloro-1,3,5-triazine yielded well developed needle-shaped crystals whose X-ray-powder pattern did not match with that of the known orthorhombic compound with the space group P212121 [1]. The investigation of a needle-shaped single crystal revealed a new monoclinic modification, which crystallizes in the space group P21/c. At T = 220 K the following lattice parameters were refined: a = 8.403(1) Å, b = 12.152(1) Å, c = 13.898(2) Å and β = 123.01(1)°. The unit cell volume amounts to 1190(1) Å3 for 8 formula units.
In-situinvestigation of oxygen diffusion in Sr, Mg-doped LaGaO3superionic conductors with a simultaneously applied electric field
Authors: Günter Marco Maria , Boysen Hans , Corte Carsten , Lerch Martin , Suard Emanuelle
Published: February 2005

In-situneutron powder diffraction investiägations of the oxygen super-ionic conductors La0.9Sr0.1Ga0.8Mg0.2O2.85and La0.8Sr0.2Ga0.8Mg0.2O2.80were performed at 1460 K with and without an applied electric field (U= 3 V DC) resulting in lasting ionic currents of 180–270 mA. At this temperature both samples adopt the cubic perovskite structure (Pm-3m). Field-induced structural changes are evidenced by anharmonic terms in the Debye-Waller factors of oxygen only for the first sample. The corresponding probability density function maps indicate curved diffusion pathways around the Ga atoms shifted further into the direction of an octahedral void with applied field. In addition, double maxima appear in the direction of the Ga—O bond which are more prominent in the second sample. A tentative explanation of the observed phenomena is given in terms of long range ordering of the corresponding potential minima and residual short range order clusters persisting at high temperatures.
High-pressure phase transition of the oxonitridosilicate chloride Ce4[Si4O3+xN7–x]Cl1–xOx with x = 0.12 and 0.18
Authors: Friedrich Alexandra , Knorr Karsten , Lieb Alexandra , Rath Stephanie , Hanfland Michael , Winkler Björn , Schnick Wolfgang
Published: February 2005

The high-pressure behaviour of the oxonitridosilicate chlorides Ce4[Si4O3+xN7–x]Cl1–xOx, x = 0.12 and 0.18, is investigated by in situ powder synchrotron X-ray diffraction. Pressures up to 28 GPa are generated using the diamond-anvil cell technique. A reversible phase transition of first order occurs at pressures between 8 and 10 GPa. Within this pressure range the high- and the low-pressure phases are observed concomitantly. At the phase transition the unit cell volume is reduced by about 5%, and the cubic symmetry (space group P213) is reduced to orthorhombic (space group P212121) following a translationengleiche group-subgroup relationship of index 3. A fit of a third-order Birch-Murnaghan equation of state to the p–V data results in a bulk modulus B
0 = 124(5) GPa with its pressure derivative B′ = 5(1) at V
0 = 1134.3(4) Å3 for the low-pressure phase and in B
0 = 153(10) GPa with B′ = 3.0(6) at V
0 = 1071(3) Å3 for the high-pressure phase. The orthorhombic phase shows an anisotropic axial compression with the a axis (which is the shortest axis) being more compressible (k(a) = 0.0143(4) 1/GPa) than the b and c axes (k(b) = 0.0045(2), k(c) = 0.0058(2) 1/GPa). The experimental results confirm an earlier prediction of the pressure-induced instability of isotypic Ce4[Si4O4N6]O, and also show that the bulk modulus was predicted reasonably well.
Noncentrosymmetric coordination networks based on nitrate and acetylenedicarboxylate anions
Authors: Schuy Andrea , Billetter Heinrich , Hohn Frauke , Pantenburg Ingo , Ruschewitz Uwe
Published: February 2005

Single crystals of Ba2(ADC)(NO3)2 · 4 H2O (1), Ba7(ADC)6(NO3)2 · 14 H2O (2), and Ba3(ADC)2Cl(NO3) × 5 H2O (3) were prepared by crystallisation at the phase boundary of a two phase system (ADC = C2(COO)2). They crystallize in noncentrosymmetric space groups (1: C2221, Z = 4; 2: I2, Z = 2; 3: P2212, Z = 2). For 1 a SHG signal of approx. 0.29 KDP (1 KDP = SHG of KH2PO4) was determined. All hitherto known compounds of the almost linear dianion of acetylenedicarboxylic acid crystallize in centrosymmetric space groups, but by inserting trigonal planar nitrate anions into the crystal structure a symmetry breaking seems to occur, which leads to noncentrosymmetric crystal structures. Several examples from the literature show that this observation might be also valid for other compounds.
The crystal structure of γ-P4, a low temperature modification of white phosphorus
Authors: Okudera Hiroki , Dinnebier Robert E. , Simon Arndt
Published: February 2005

The crystal structure of γ-P4, one of three modifications hitherto reported on white phosphorus, was determined from X-ray powder diffraction data collected at T = 123 K on a Guinier-Simon camera equipped with a cold gas blower and an image plate detector. Crystallographic data at T = 123 K are: space group C2/m, a = 9.1709(5) Å, b = 8.3385(5) Å, c = 5.4336(2) Å, and β = 90.311(3)°, V = 415.51(6) Å3, Z = 4. The crystal structure of γ-P4 was solved by the method of simulated annealing. The subsequent Rietveld refinement in the range 12° < 2θ < 92° employing rigid-body constraints on the P4 molecule converged at Rp
= 3.8, wRp
= 5.0, and RF

2 = 14.0%. The asymmetric unit of γ-P4 contains three P atoms; two P atoms in a molecule are related by a mirror plane which bisects the molecule. The centers of gravity of these P4 molecules show a distorted body-centered cubic arrangement. The four apices of the P4 tetrahedron point to the largest possible voids formed by neighbor molecules. The difference to the crystal structures of SiF4 and GeF4 with an exact bcc arrangement of tetrahedral molecules is discussed as well as, in terms of layer stackings, the similarity of the structures of γ- and β-P4.
Phosphorus-rich phosphorus selenides P14+xSe (x = 1, 5)
Authors: Ruck Michael , Hoppe Diana , Simon Paul
Published: February 2005

New phosphorus-rich phosphorus selenides P14+xSe (x = 1, 5) were synthesized by reaction of amorphous red phosphorus and SeO2. The crystal structures of P15Se and P19Se were solved from single-crystal X-ray data (space group Pnma (No. 62); P15Se: a = 9.963(2) Å, b = 3.231(1) Å, c = 13.412(3) Å; P19Se: a = 9.917(2) Å, b = 3.230(1) Å, c = 13.410(3) Å). The structures consist of pentagonal tubes packed collaterally with two-dimensional disorder, which was confirmed by TEM investigations.
Crystal structure and optical properties of the new 8O polytype of Ca2Ta2O7
Authors: Ebbinghaus Stefan G. , Kalytta Andreas , Kopf Jürgen , Weidenkaff Anke , Reller Armin
Published: February 2005

Single crystals of the new 8O modification of Ca2Ta2O7 were grown by optical floating zone melting and their structure was solved by X-ray diffraction. 8O Ca2Ta2O7 crystallizes in space group C2221 with a = 7.3690(2) Å, b = 12.7296(3) Å, c = 48.263(1) Å. The structure is related to the weberite structure type and can be described as a stacking of 8 basic building units per unit cell. Each building unit consists of one Ta3Ca and one Ca3Ta layer with a cubic close packed arrangement. Transmission measurements in the UV-Vis and IR region reveal a high transparency in a wide energy range from 0.2–3.5 eV. Dielectric measurements yield a high ɛ′ value of 60 at room temperature.
Photoluminescence of ZnGa2S4 : Eu2+
Authors: Wickleder Claudia , Zhang Shuang , Haeuseler Hartmut
Published: February 2005

ZnGa2S4:Eu2+ shows a light green emission at room as well as at low temperatures. The maximum of the band of the 4f65d1 → 4f7 emission is located at about 536 nm (18657 cm–1) and depends slightly on the excitation energy. The respective excitation band has a maximum at 470 nm (21277 cm–1). These results lead to the assumption that the Eu2+ ions are substituted at octahedral voids of the host lattice rather than at cationic sites. This is to be expected also because of the different ionic radii of the cations. Further emission and excitation bands are detected at higher energies in ZnGa2S4:Eu2+ as well as in undoped ZnGa2S4 which depend strongly on the respective excitation and emission energies and can, thus, be assigned to host lattice bands.
In situ bulk structural study on solid-state dynamics and catalytic activity correlations of a H4[PNbMo11O40] partial oxidation catalyst
Authors: Ressler Thorsten , Timpe Olaf , Girgsdies Frank
Published: February 2005

We report on the preparation and characterization of a niobium containing Keggin type heteropolyoxomolybdate (HPOM), H4[PNbMo11O40] · 13 H2O, with Nb substituting Mo in the Keggin ion. H4[PNbMo11O40] · 13 H2O exhibits a long-range order structure similar to that of H3[PMo12O40] · 13 H2O. The structural evolution of H4[PNbMo11O40] · 13 2O was studied under reducing (propene) and partial oxidation reaction conditions (propene and oxygen) by in situ X-ray diffraction and X-ray absorption spectroscopy combined with mass spectrometry and corroborated by thermogravimetric analysis. Following the loss of crystal water in the temperature range from 373 K to 573 K, a partial decomposition and reduction of the molybdenum and the formation of a characteristic cubic HPOM is observed at 573 K, similar to the structural evolution of H3[PMo12O40] · 13 H2O and H4[PVMo11O40] · 13 H2O during treatment in propene. However, in contrast to H3[PMo12O40] · 13 H2O and H4[PVMo11O40] · 13 H2O, the cubic HPOM decomposes rapidly and the MoO3 formed is subsequently reduced to MoO2. Nb centers in the Keggin ion considerably destabilize the HPOM and accelerate the decomposition towards MoO3. A similar structural evolution is observed under propene and oxygen. The formation of the cubic HPOM with Mo centers on extra-Keggin framework positions coincides with the onset of catalytic activity. However, at about 673 K the active phase further decomposes to a mixture of MoO3 and a more stable cubic HPOM resulting in a pronounced decrease of the catalytic activity. Evidently, preparation and structure-activity relationships for Nb containing mixed metal oxide catalysts need to take into account the particular structure directing properties of Nb during thermal activation.
The coloring problem in intermetallics: bonding and properties of Tb3Zn3.6Al7.4 with the La3Al11 structure type
Authors: Han Mi-Kyung , Morosan Emilia , Canfield Paul C. , Miller Gordon J.
Published: February 2005

Single crystals of the new compound Tb3Zn3.6(1)Al7.4(1) were obtained from Al and Zn-rich ternary solutions. The title compound crystallizes in the orthorhombic La3Al11 structure type (space group Immm (No. 71), Z = 2; a = 4.2334(1) Å, b = 9.9725(3) Å, c = 12.4659(1) Å). The inverse susceptibility above ca. 50 K shows Curie-Weiss behavior, and a metamagnetic transition is apparent in the T = 2 K field-dependent magnetization around Hc
∼ 20 kG. The resistivity increases with temperature in a roughly linear fashion, indicating the metallic character of this material. TB-LMTO-ASA electronic structure calculations indicate that this new intermetallic phase has all bonding states optimized in the [Zn4–xAl7+x] network, which classifies this compound among the so-called “polar intermetallics”. The calculations also provide a rationalization of the nonrandom ordering of Zn and Al atoms, which can be attributed to optimizing (Zn, Al)—(Zn, Al) orbital interactions.
Slow Food in a Fat Society: Satisfying Ethical Appetites
Authors: paxson heather
Published: February 2005

Slow Food in a Fat Society

Using historian Hillel Schwartz's utopian conception of a "fat society" as inspiration, this essay considers the potential contribution of the Slow Food movement to American notions of dietary ethics. In the United States, eating has been morally evaluated largely in terms of self-control, in relation to personal health and body image. In contrast, the dietary ethos of Slow Food is notable for its disregard of bodily aesthetics and secondary attention to nutrition. Slow Food might offer a path for redirecting moral consideration of food and eating away from the narcissistic, singular body, and toward a culinary ethic emphasizing our responsibilities to human and animal others, to cultural heritage, and to the environment.
The Cooking Ape: An Interview with Richard Wrangham
Authors: townsend elisabeth
Published: February 2005

Humans: The Cooking Ape

Perhaps the first to suggest that humans were cooking as early as 1.9 million years ago, Richard Wrangham shows through his new research and his imagination how and possibly when cooking changed humans dramatically. Wrangham, Harvard University primatologist and MacArthur Fellow, has been studying the evolution of human cooking. After 25 years of primate research at his site in Kibale, Uganda, Wrangham is best known for explaining the similarity and differences across species of primate social organizations. In Kibale, he has analyzed chimpanzees’ behavior: how it’s changed when they interact with the environment and how their social groups have evolved. In particular, he noticed how food changed their interactions with each other. Like that of chimps, human behavior has been affected by food, especially as they shifted from raw to cooked food. Moving from eating food as it was discovered to collecting edibles and cooking them altered our social relationships. Cooked food has changed Homo sapiens physically by making food more digestible thereby altering jaws, teeth, and guts, and providing more calories for more expensive organs such as the brain. Wrangham discusses when and how humans may have started using fire to cook food, what they cooked, and the transition from cooking in an outdoor fire to hearths and open ovens.
Sicilian Manna: A Sweet Gift of Nature
Authors: lanza anna tasca
Published: February 2005

An Unusual Ingredient – Manna

Manna, a gift from nature, comes from a kind of ash called “Fraxinus angustifolia” or “Fraxinus ornus” found in the surrounding areas of the towns of Castelbuono, Pollina and Cefalù (Italy). In the past, it was grown extensively in the Mediterranean basin though all traces of it seem to be lost. The history is pieced together with historical references from the Bible, health manuals from ancient civilizations, and references to the implements used to harvest it. Its mysterious or miraculous properties are presented; two kinds of manna were thought to exist, one from Heaven, and the other from a tree.

The ideal conditions for growing the trees and harvest are described with plentiful folklore, local customs, special vocabulary and tools mentioned. Manna is harvested in summertime when the plant is “in love”, from June to September or until the first rains, which would dissolve it, start to fall. The people of Pollina romantically call manna, “a sweet gift of nature”. It tastes like honey mixed with carob. The sap flows through a gash made with a special technique, using a curved cutter called a “mannarolo,” on the vein of the trunk of the tree, and it is left to drip for several days. The sap crystallizes and forms long clumps similar to stalactites, which are called “cannolo” in the manna-world vocabulary. The juice is violet and very bitter when it drips, but the contact with the air and the strong Sicilian sun dries and sweetens it. “Cannoli” are harvested with an “archetto.” There is a second and third grade of sap, which doesn’t crystallize or form cannoli. Prickly-pear leaves act as a sort of spout to catch the manna.

Its medicinal qualities include its mild laxative effect, its natural sweetness for dietary purposes, and its use in digestive alcoholic drinks and cosmetics is noted. It is sold at pharmacies and tobacco stores.
““Take One More Bite for Me””: Clara Davis and the Feeding of Young Children
Authors: scheindlin benjamin
Published: February 2005

Clara Davis and the Feeding of Young Children

Parents often worry about their children’s nutrition. Children under six engender particularly high parental anxiety, because of their young age and their naturally variable eating habits. In the 1920s, pioneering Midwestern pediatrician Clara Davis set out to determine if young children instinctively know what to eat, in her “self-selection of diet experiment.”

Davis offered newly weaned infants, aged seven to nine months, a wide variety of nutritious, unmixed meats, grains, vegetables, and fruits. She allowed them to eat whichever foods they chose, in whatever quantity they wanted, without adult guidance or interference. She measured the amounts eaten carefully, even weighing bibs to subtract the amount spilled, and calculated the children’s intake of calories, carbohydrate, fat, and protein. The study period lasted six to twelve months. The children tended to eat widely varying amounts from meal to meal, often displaying “food jags” during which they ate considerable quantities of a favored food. Overall they ate a wider variety and greater amount of foods than pediatricians of the day thought advisable, without any of the “pickiness” that plagued parents and pediatricians then as now. Furthermore, all the children grew and developed well and were quite healthy.

Subsequent research has confirmed Davis’ findings, in shorter, smaller-scale studies, some of which are discussed. Comment is made about the ethical complexion of Davis’ long term experiment from today’s viewpoint. Davis was always quick to point out what she herself called “the trick” of her experiment, that the infants and toddlers only had foods of high nutritional value to choose from, and never saw any junk food.
Measuring Ingredients: Food and Domesticity in Mexican Casta Paintings
Authors: scott nina m.
Published: February 2005

Measuring Ingredients: Food and Domesticity in Mexican Casta Paintings

Mexican casta paintings flourished as a popular art form in the eighteenth century. No one is sure of the exact origin of this type of painting, which depicted racial mixtures accompanied by local foods; most likely it was an export item for wealthy Spaniards who were returning home and wanted a souvenir of colorful and exotic Mexico.

Casta paintings were generally created in sets of sixteen canvases, and depicted all manner of racial hybridization among Whites, Blacks and Amerindians. The common trope was to portray a father, a mother, and an offspring, beginning with the Spanish male with Indian and Black consorts, and ending with an Indian couple, groupings which reflected social hierarchies of the colonial world. Most were painted by anonymous artists, though the canvases analyzed in this study are by known painters. Because of the emphasis on domestic relations, couples were often portrayed in kitchens or markets, which gives us valuable information on this aspect of daily life. The foods associated with the different castes also reflected socio-economic hierarchies, as well as reinforced the idea of America as land of bounty.

Colonial artists generally imitated European models, but with the casta paintings Mexican artists were instead urged to paint what distinguished their country from Spain, hereby contributing to a growing sense of independence from the metropolis.
Solving the Puzzle of Barolo and Barbaresco
Authors: smith brian
Published: February 2005

Solving the Puzzle of Barolo and Barbaresco

The Northeastern Italian region of Piedmont is home to the red wines of Barolo and Barbaresco, both of which have fascinated wine lovers for centuries. Part of their fascination is the Nebbiolo grape that is used to produce these wines – in the right hands, Nebbiolo can produce extremely attractive wines, full of exciting flavors and capable of aging for many years. But there are other elements that might be more important for the overall character of the wine than the hands of the winemaker, and those include the location of the vineyards, the environment that the grapes grow in, and, especially, the soil structure beneath the vines. Variations from one place to another mean that two wines labeled Barolo will not necessarily offer the same flavor profile.

Whereas there is a general set of characteristics that can be attributed to the wines of Barolo and Barbaresco, the influence of place is such that there are nuances that are enhanced by some soil structures, or reduced by others. Combining information about the different geological influences with empirical tasting experiences, this article breaks down the regions of Barolo and Barbaresco into their respective communes, with specific comments about the nature of the wines produced from Nebbiolo grapes grown within each individual commune.
Second Sight: The Art of Joan Steiner
Authors: wood d
Published: February 2005

Feast for the Eye

Joan Steiner has created a series of children’s picture books, entitled Look-Alikes, based on her observations that some objects look like others. Each book consists of about 10 illustrations intended as puzzles; readers are invited to enumerate the substitutions of look-alikes for their real counterparts. A barn, for instance, is a green metal toolbox and its silo is an aerosol can with toy train tracks as its ladder. The high incidence of food and food-related items in her work flaunts our expected purpose for and context of edibles. Steiner’s inventiveness is reminiscent of the Italian mannerist painter Arcimboldo whose portraits also employ food substitutions.
The Nature of Redemption
Authors: Fletcher Paul
Published: February 2005

This article enacts a critical engagement with Romantic tendencies in theological analyses of nature before moving on to assess the transformation of conceptions of life in the light of its codification and digitalisation. The piece concludes with a theological-political rejoinder predicated on the nature of messianic expectation.
An Ethics of NatureCulture and Creation
Authors: O'Brien Kevin
Published: February 2005

This essay first explores the postmodern, ecofeminist ethics emerging from Donna Haraway’s analysis of non-dualistic cyborg reality. It then argues that this perspective has many similarities with and much to teach to ecotheological ethics. I conclude with three ideas which I believe Haraway’s thought can contribute to the development of an environmental ethics in the Christian tradition: a clear and importantly complex picture of our world’s particular moral challenges, a modest approach to developing solutions to these challenges, and an emphasis on making explicit the problematic and destructive tendencies of the traditions within which we work
Augustinian Ecological Democracy
Authors: Szerszynski Bronislaw
Published: February 2005

In this article I critically explore the work of the social theorists Klaus Eder and Ulrich Beck, who in different ways use an account of the ‘postmodern’, plural character of contemporary ideas of nature to argue for the necessity and possibility of an ecological democracy. I argue that within such social theoretical understandings of the contemporary politics of nature is a tension between pagan and Christian understandings of difference—between an understanding of difference as fundamentally irreducible and irreconcilable, and one that sees difference as contained within an over-arching harmony. I cast suspicion on an account of postmodern difference which would see it as the resurgence of a pagan polytheism which had merely suppressed by two millennia of monotheism, in favour of an alternative account in which it appears as a historical product of the contingent path taken by the development of the Western sacred. I then explore ways in which Christian thought can provide the basis for an ontology of original peace in contrast to the original violence of pagan thought, on the basis of which might be built a different, ‘gothic’ understanding of ecological democracy, in which consensus is not grounded in the suppression of polysemy but in the harmonization of generative difference.
Christianity and Ecological Ethics
Authors: Deckers Jan
Published: February 2005

Christianity has contributed to the development of a strong anthropocentric ethic. Christian theologians have developed new ways of thinking about the place of humans in nature, often by focussing on the God-humanity relationship. Thinking about the third component of the metaphysical trinity, nature, has largely remained unchanged. Christian theology needs to make an ontological detour or tour de force to overcome lingering materialist and dualist conceptions of nature, and to embrace key aspects of process thought, most notably panexperientialism. This will pave the way for the required weak anthropocentric ethic.
Modeling and kinetics of allylation of phenol in a triphase‐catalytic membrane reactor
Authors: Wu Ho‐Shing , Lo May‐Huey
Published: February 2005

The reaction of allyl bromide with phenol, in the presence of quaternary methyl ammonium membrane in a 1,2‐dichloroethane/aqueous solution in a membrane reactor, was investigated. The reaction mechanism of this system was described by combining the experimental data and Langmuir–Hinshelwood theory. Theoretical models and calculations were performed to predict the kinetic behavior of the reaction system. Experimental results confirmed the developed model. The parameters of selectivity coefficient, adsorbing rate constant, and activation energy were obtained. © 2005 American Institute of Chemical Engineers AIChE J, 51: 960–970, 2005
Kinetics of dibenzylether hydrothermolysis in supercritical water
Authors: González Guillermo , Montané Daniel
Published: February 2005

The kinetics of dibenzylether (DBE) hydrothermolysis in hot compressed water has been investigated in a continuous tubular reactor system at a pressure from 225 to 362 bar, temperature from 325 to 390°C, and a constant water load of ΘW = 100 molwater/molDBE. Thermal scission of DBE yielded equimolar amounts of benzaldehyde and toluene; the rate constant in supercritical water decreased with water density showing that the volume of activation was positive, as expected for an unimolecular scission reaction. Benzyl alcohol was produced by DBE reversible hydrolysis catalyzed by free protons from water dissociation. Density and dielectric constant of water decreased the rates of hydrolysis and DBE formation, which means that the transition state complex has a positive volume of activation, and a lower dipolar moment than the reactants. As the dielectric constant raises the reaction rates are lowered, but the equilibrium shifts toward the formation of benzyl alcohol, which is more polar than DBE. The low dipole moment of the transition state complex was further supported by the negative effect of the ionic strength on the rate constant for DBE hydrolysis. © 2005 American Institute of Chemical Engineers AIChE J, 51: 971–981, 2005
Design of micro‐scale fuel processors assisted by numerical modeling
Authors: Cao Chunshe , Wang Yong , Holladay Jamie D. , Jones Evan O. , Palo Daniel R.
Published: February 2005

Computer‐aided design (CAD) of a micro‐scale fuel processor is described. Transport phenomena and reaction processes in a methanol steam reformer and a selective carbon monoxide methanator have been mathematically illustrated with a three‐dimensional pseudo‐homogeneous model based on fundamental conservation laws of mass and energy. Simulations provide carbon conversion as well as local temperature distributions in the micro‐scale fuel processors. Various reactor design options were evaluated by such numerical modeling predictions. The tailored temperature profile in the optimized reactor configuration and process conditions give high efficiency in generating low‐CO–content hydrogen‐rich gas stream for miniature fuel cell applications. © 2005 American Institute of Chemical Engineers AIChE J, 51: 982–988, 2005
Deactivation dynamics of rough catalytic surfaces
Authors: Filoche M. , Sapoval B. , Andrade J. S.
Published: February 2005

The dynamics of deactivation due to parallel fouling is investigated in the case of a rough reactive interface under diffusion‐limited conditions. For a first‐order reaction, a mathematical method is introduced that permits to analyze the response of the system for any type of interface geometry or input condition. Exact analytical results, such as the lifetime of the catalyst or its total production are calculated. The deactivation dynamics in specific geometries, such as a flat catalytic surface, an infinite pore or a rough surface, are examined. Through these three examples, a general picture of the role of the morphology on the system response is provided. Even more, this approach shows that the determination of a single time response function of a catalyst of unknown morphology provides a means to control the dynamics of the production process. © 2005 American Institute of Chemical Engineers AIChE J, 51: 998–1008, 2005
Electrochemically enhanced biosynthesis of gluconic acid
Authors: Gros Pierre , Bergel Alain
Published: February 2005

A bioelectrochemical interface was designed by entrapping glucose oxidase (GOx) in a polypyrrole film electrosynthesized on a platinum electrode. The efficiency of the modified electrodes for synthesis was evaluated with the reaction of glucose oxidation into gluconic acid by oxygen. Glucose transformation was carried out with or without the electrochemical step. The electrochemical step led to the regeneration of oxygen, which also ensured the oxidation of the hydrogen peroxide produced as a by‐product, thus protecting GOx against denaturing. The experimental results were first analyzed according to the “effectiveness factor/Thiele modulus” classic approach. They were confirmed theoretically by a model based on the resolution of glucose mass balance equation. Second, the simulation of the concentration profiles of oxygen and hydrogen peroxide inside the polymer film explained the experimental data, highlighting the protection of the enzyme by the electrochemical step. The maximum conversion yield was obtained with a 500‐nm‐thick polymer. As a consequence of the combined effects of oxygen regeneration and enzyme protection, the electrochemical step increased by a factor of 2 the transformation ratios obtained with immobilized GOx. Furthermore, the electrochemically enhanced process was 50% more efficient than the equivalent homogeneous process carried out for 24 h with the same amount of enzyme. © 2005 American Institute of Chemical Engineers AIChE J, 51: 989–997, 2005
Superior verbal ability and nonverbal learning disability in a child with a novel 17p12p13.1 deletion
Authors: Steele D.L. , Chisholm A.K. , McGhie J.D.R. , Gardner R.J.M. , Scheffer I.E. , Slater H.R. , Dawson G.
Published: February 2005

We report the case of a 10‐year‐old girl with the karyotype 46,XX,del(17)(p12p13.1) who presented a remarkable incongruence in higher cerebral functioning. Certain language skills were very superior, with reading and spelling at a 17–19 year‐old level of proficiency. Nonverbal skills, however, were mostly below average, executive functioning and socialization were impaired, and a diagnosis of “nonverbal learning disability” is applied. We speculate that the genes deleted include one or some which code for certain specific categories of neural substrate that subserve aspects of visual processing and higher functioning, but that no “language loci” have been deleted. The particular neuropsychological profile that we describe may assist diagnosis of this chromosomal deletion. © 2005 Wiley‐Liss, Inc.
Association analysis of the monoamine oxidase A and B genes with attention deficit hyperactivity disorder (ADHD) in an Irish sample: Preferential transmission of the MAO‐A 941G allele to affected children
Authors: Domschke Katharina , Sheehan Karen , Lowe Naomi , Kirley Aiveen , Mullins Celine , O'Sullivan Roderick , Freitag Christine , Becker Tim , Conroy Judith , Fitzgerald Michael , Gill Michael , Hawi Ziarih
Published: February 2005

Pharmacological and genetic studies suggest the importance of the dopaminergic, serotonergic, and noradrenergic systems in the pathogenesis of attention deficit hyperactivity disorder (ADHD). Monoamine oxidases A and B (MAO‐A and MAO‐B) degrade biogenic amines such as dopamine and serotonin and thereby control the levels of these neurotransmitters in the central nervous system. We examined four polymorphisms in the MAO‐A gene (30 bp promoter VNTR, CA microsatellite in intron 2, 941G/T SNP in exon 8, and A/G SNP in intron 12) as well as two markers in the MAO‐B gene (CA microsatellite in intron 2 and T/C SNP in intron 13) for association with ADHD in an Irish sample of 179 nuclear families. TDT analysis of the examined MAO‐A markers revealed a significant association of the more active MAO‐A 941G allele with the disorder (χ2 = 5.1, P = 0.03, OR = 1.7). In addition, haplotype analysis revealed a significantly increased transmission of a haplotype consisting of the shorter allele of the promoter VNTR (allele 1), the 6‐repeat allele of the CA microsatellite and the G‐allele of the 941G/T SNP (famhap global statistic 34.54, P = 0.01) to ADHD cases. No significant distortion in the number of transmitted alleles was observed between the two examined MAO‐B polymorphisms and ADHD. These findings suggest the importance of the 941G/T MAO‐A polymorphism in the development of ADHD at least in the Irish population. © 2005 Wiley‐Liss, Inc.
Synthesis and properties of poly(aryl ether sulfone ether ketone ketone) (PESEKK)
Authors: Wen Hong‐Li , Song Cai‐Sheng , Tong Yong‐Fen , Chen Lie , Liu Xiao‐Ling
Published: February 2005

4,4′‐bis(Phenoxy)diphenyl sulfone (DPODPS) was synthesized by reaction of phenol with bis(4‐chlorophenyl) sulfone in tetramethylene sulfone in the presence of NaOH. Two poly(aryl ether sulfone ether ketone ketone)s (PESKKs) with high molecular weight were prepared by low temperature solution polycondensation of DPODPS and terephthaloyl chloride (TPC) or isophthaloyl chloride (IPC), respectively, in 1,2‐dichloroethane and in the presence of aluminum chloride (AlCl3) andN‐methylpyrrolidone (NMP). The resulting polymers were characterized by various analytical techniques, such as FT‐IR,1H‐NMR, DSC, TG, and WAXD. The results show that theTgandTdof PESEKKs are much higher, but itsTmis lower than those of PEKK. The other results indicate that PESEKKs exhibit excellent thermostabilities at 300 ± 10°C. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 489–493, 2005
DABCO‐Directed Self‐Assembly of Bisporphyrins (DABCO=1,4‐Diazabicyclo[2.2.2]octane)
Authors: Ballester Pablo , Costa Antoni , Castilla Ana M. , Deyà Pere M. , Frontera Antonio , Gomila Rosa M. , Hunter Christopher A.
Published: February 2005

Three isomeric zinc bisporphyrins have been prepared by covalently linking together two aminoporphyrins with an isophthalic acid derivative. The porphyrins differ in the substitution pattern on the meso phenyl groups, that is, ortho, meta, or para. Titrations carried out by UV‐visible and 1H NMR spectroscopy have been used to map out the stabilities and the stoichiometries of the complexes formed with 1,4‐diazabicyclo[2.2.2]octane (DABCO) in chloroform. The ortho‐ and meta‐substituted bisporphyrins form 1:1 intramolecular sandwich complexes. The para‐substituted bisporphyrin cannot adopt the cofacial conformation required for this type of complex and forms a higher order 2:2 intermolecular assembly, which is stable over a wide range of DABCO concentrations.
The prognostic impact of the ubiquitin ligase subunits Skp2 and Cks1 in colorectal carcinoma
Authors: Shapira Ma'anit , Ben–Izhak Ofer , Linn Shai , Futerman Boris , Minkov Ira , Hershko Dan D.
Published: February 2005

BACKGROUND

Loss of the cell‐cycle inhibitory protein p27Kip1 is associated with poor prognosis in colorectal carcinoma. The decrease in p27Kip1 levels is the result of increased proteasome‐dependent degradation, mediated and rate‐limited by its specific ubiquitin ligase subunits S‐phase kinase protein (Skp) 2 and cyclin‐dependent kinase subunit (Cks) 1. Recently, Skp2 and Cks1 expression were found to be increased in some colorectal carcinomas, but their potential role as prognostic markers for survival is unknown. The present study was undertaken to assess the prognostic value of both Skp2 and Cks1 in colorectal carcinoma.

MATERIALS AND METHODS

The expression of Skp2, Cks1, and p27Kip1 was examined by immunohistochemistry using highly specific antibodies on formalin‐fixed, paraffin‐embedded tissue sections from 80 patients with colorectal carcinoma.

RESULTS

Overexpression of Skp2 and Cks1 strongly correlated with loss of p27Kip1 and loss of tumor differentiation. A significant decrease in overall survival was observed in patients expressing high Skp2 or Cks1 levels, and in particular, patients with Stage II and III disease. Each protein provided significant additional prognostic information to that given by disease stage, tumor grade, or p27Kip1 expression.

CONCLUSIONS

Results suggest that overexpression of Skp2 or Cks1 is strongly associated with poor prognosis and may thus be used as prognostic markers for overall survival in colorectal carcinoma. Cancer 2005. © 2005 American Cancer Society.