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Carbon-silicon alloys in different stoichiometric ratios are synthesized by delithiation of carbon-lithium-silicon ternary alloys with ethanol followed by washing with HCl and distilled water. The as-prepared carbon-silicon materials are air and water stable. In contrast to mechanically milled or sputtered C-Si alloys studied in the past, the method of synthesizing C-Si alloys introduced in this work avoids the formation of inactive SiC even after two hours high energy ball milling. This results in C-Si alloys with significantly greater volumetric and specific capacity. When cycled in Li half-cells, C-Si alloys exhibit good cycling performance and lower volume expansion compared to conventionally made Si alloys. This is attributed to the presence of void spaces in the structure which can accommodate some of the Si volume expansion.

Under the Church Building Acts beginning in 1818, new English Anglican churches received governmental approval to formally rent sittings to congregants. Initial profits seem to have been high enough to make the practice financially viable. But over the Victorian era a flurry of popular protests and governmental acts, combined with lower rates of church-going, reduced the profitability of pew-renting. Churches built under the auspices of the Church Building Commissioners were generally offered grants in exchange for ending pew-rents. S.J.D. Green concluded that pew-renting was generally extinguished by the 1920s or earlier, which is correct regarding Anglican churches which received such “in lieu” grants. But Green’s assessment must be modified for other churches receiving no grants and needing even small profits. Primary sources reflect that many of these continued to set sittings for decades after the 1920s—in a few cases, into the 1960s and 1970s.

Before the early nineteenth century pew-renting was comparatively rare in Anglican churches, and where it existed the practice was generally administered as a less serious means of fund-raising. But just before 1800 or so, methods of administering the letting of sittings became more businesslike and impersonal. The frequency of pew-renting grew exponentially with the advent of the Church Building Acts beginning in 1818, but the profits realised were usually less than is assumed. The often offensive and sometimes dishonest administration of pew-rent schemes, when later combined with waning churchgoing and a consequent surfeit of rentable sittings, marked the system's decline.

Ordering of the two incommensurate charge density waves (CDW), ${\mathbf{q}}_{1}=(0.0, 0.243, 0.0)$ and ${\mathbf{q}}_{2}=(0.5, 0.263, 0.5)$, in the quasi-one-dimensional ${\mathrm{NbSe}}_{3}$ structure is studied by means of low-temperature scanning tunneling microscopy. Larger (100) van der Waals surfaces are analyzed using one-dimensional Fourier transforms along the three types of trigonal prismatic columns, running parallel to the monoclinic ${\mathbf{b}}_{0}$ direction. The procedure enables unambiguous differentiation between both CDWs modulating individual columns. In addition, it allows a quantitative comparison of modulation amplitudes along different columns of the same type and, in case of sufficiently large images, also along individual columns. It is confirmed that each CDW modulates both type-III and type-I columns with the narrowest isosceles bases. As a consequence beating is observed between the two slightly different modes. The bridging type-II columns appear not to be modulated. On a large scale the modulation amplitudes along individual columns vary, suggesting formation of CDW nanodomains. The possibility of interchanging both CDWs along columns forming symmetry-related pairs results in a charge difference, which is supposed to be the possible origin of CDW sliding.

The basic and the charge density wave (CDW) structures of the monoclinic ${\mathrm{NbS}}_{3}$-II polymorph were studied by synchrotron x-ray diffraction, ab initio calculations, simulation of electron diffraction patterns, and by atomic-resolution transmission electron and low-temperature scanning tunneling microscopies. It is confirmed that the basic structure belongs to the space group $P{2}_{1}/m$ and is described with a unit cell, formed of four pairs of symmetry-related trigonal prismatic (TP) columns [${a}_{0}=0.96509(8)\phantom{\rule{4pt}{0ex}}\mathrm{nm}$, ${b}_{0}=0.33459(2)\phantom{\rule{4pt}{0ex}}\mathrm{nm}$, ${c}_{0}=1.9850(1)\phantom{\rule{4pt}{0ex}}\mathrm{nm}$, and ${\ensuremath{\beta}}_{0}=110.695{(4)}^{\ensuremath{\circ}}$]. The incommensurate components of the two CDWs, $\stackrel{P\vec}{{q}_{1}}=(0,\phantom{\rule{4pt}{0ex}}0.298,0)$ and $\stackrel{P\vec}{{q}_{2}}=(0,\phantom{\rule{4pt}{0ex}}0.352,\phantom{\rule{4pt}{0ex}}0)$, are related as ${q}_{{1}_{b}}+2{q}_{{2}_{b}}\ensuremath{\approx}1$. Both CDWs form their own modulation patterns with unit cells (${a}_{\mathrm{m}}=2{a}_{0}$, ${b}_{\mathrm{m}}={b}_{0}/{q}_{\mathrm{jb}}$, ${c}_{\mathrm{m}}={c}_{0}$, ${\ensuremath{\beta}}_{m}={\ensuremath{\beta}}_{0}$) and are ordered along adjacent isosceles TP columns either pairwise or with both columns modulated by either the $\stackrel{P\vec}{{q}_{1}}$ or $\stackrel{P\vec}{{q}_{2}}$ CDW only. The CDWs are ordered according to one of the two possible modulation pattern space groups, $Cm$ or $C2/m$. If considered as long-period commensurate, the entire modulated structure with both CDWs included is described within experimental error with an enlarged unit cell ($a=2{a}_{0}$, $b=37{b}_{0}$, $c={c}_{0}$, and $\ensuremath{\beta}={\ensuremath{\beta}}_{0}$) and with all atoms displaced from their average positions in accord with the specified modulation pattern.

This work demonstrates the production of a well-controlled, chemical gradient on the surface of graphene. By inducing a gradient of oxygen functional groups, drops of water and dimethyl-methylphosphonate (a nerve agent simulant) are "pulled" in the direction of increasing oxygen content, while fluorine gradients "push" the droplet motion in the direction of decreasing fluorine content. The direction of motion is broadly attributed to increasing/decreasing hydrophilicity, which is correlated to high/low adhesion and binding energy. Such tunability in surface chemistry provides additional capabilities in device design for applications ranging from microfluidics to chemical sensing.

We review the features of the charge density wave (CDW) conductor $\mathrm{Nb}{\mathrm{S}}_{3}$ (phase II) and include several additional results from transport, compositional, and structural studies. Particularly, we highlight three central results: (1) In addition to the previously reported CDW transitions at ${T}_{\mathrm{P}1}=360\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ and ${T}_{\mathrm{P}2}=150\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, a third CDW transition occurs at a much higher temperature ${T}_{\mathrm{P}0}\ensuremath{\approx}620\ensuremath{-}650\phantom{\rule{0.16em}{0ex}}\mathrm{K}$; evidence for the nonlinear conductivity of this CDW is presented. (2) We show that the CDW associated with the ${T}_{\mathrm{P}2}$ transition arises from S vacancies acting as donors. Such a CDW transition has not been observed before. (3) We demonstrate the exceptional coherence of the ${T}_{\mathrm{P}1}$ CDW at room temperature. The effects of uniaxial strain on the CDW transition temperature and transport are reported.

Recent studies by a number of research groups have shown that the structure of epitaxial BiFeO3 (BFO) films changes drastically as a function of substrate-induced biaxial compression, with the crystal structure changing from one being nearly rhombohedral (R-like) to one being nearly tetragonal (T-like), where the “T-like” structure is characterized by a highly enhanced c/a ratio of out-of-plane c to in-plane a lattice parameters. In this work, we show that the critical compressive strain σc necessary to induce this transition can be reduced significantly by substituting 10% Ba for Bi [Bi0.9Ba0.1FeO3−δ (BBFO)] and that the “T-like” phase in both BBFO and BFO is stable up to the decomposition temperatures of the films in air. Furthermore, our results show that the BBFO solid solution shows clear ferromagnetic properties in contrast to its undoped BFO counterpart.

a b s t r a c t Charge density wave (CDW) ordering in the prototypical low-dimensional compound NbSe3 is reconsidered. It is shown that the model with two incommensurate modulations, q1 = (0, 0.241, 0) and q2 = (0.5, 0.260, 0.5), localized on type-III and type-I bi-capped trigonal prismatic columns, does not explain details, revealed by various microscopic methods. An alternative explanation, based on the existence of modulated layered nano-domains below both CDW onset temperatures, is suggested. It accounts for the presence of the q2 modulation in the STM images recorded above the T2 CDW transition and for the absence of q2 satellites in the corresponding diffraction patterns. The long periodic modulation, detected by LT STM, is attributed to a beating between the two CDWs, centered on adjacent columns of the same type. Such pairs of alternatively modulated columns represent the basic modulation units, ordered into nano-domains.

A x Nb 3 X 4 (A = In, Tl, ZnHg; X = S, Se, Te) compounds show CDW instabilities dependent on the type and concentration of intercalate. Tl or In intercalation flattens the Fermi surfaces and supports CDW formation. In the corresponding DOS spectrum the Fermi level is shifted towards coincidence with a small peak, derived mainly from the Nb dz 2 orbital. Localized modulated regions observed in STM images of Nb 3 X 4 at room temperature represent precursor effects to full CDW formation.

Surface reaction and diffusion of gold, deposited onto the (0 0 1) ZrTe 3 van der Waals (vdW) surface, is studied by transmission electron and scanning tunneling microscopy. It is shown that both processes compete at temperatures as low as room temperature. In case of diffusion the deposited gold mostly disappears from the surface and intercalates into the vdW gaps of the substrate. Residual unreacted gold agglomerates are rather mobile and are often displaced by the scanning tip along the [1 0 0] direction of the substrate. In case of reaction, which usually takes place at somewhat higher substrate temperatures, grains of Zr 3 Te 2 , AuTe 2 and/or Au 2 Te 3 are formed. Contrary to unreacted gold, the reaction products are not mobile.

Low energy electron diffraction from clean NbTe 2 surfaces shows very diffuse reflections. The effect is attributed to an anisotropic heating of the irradiated Te-Nb-Te surface layer. Diffraction patterns for electron energies below 90 eV correspond to an overlapped contribution from numerous domains, belonging to three orientational variants. Electrons of higher energies stabilize the parent high-temperature CdI 2 structure. A similar effect is observed during scanning tunneling microscopy, where the expected surface corrugation is usually lost for tunneling currents of a few ten nA.

Scanning tunneling microscopy of freshly cleaved NbTe2 van der Waals surfaces reveals that Te vacancies regularly appear in the topmost chains of the Te surface layer. As a result of reduced symmetry with regard to the parent CdI2 structure microdomains of three possible orientational variants are formed, separated by ortho (601)- or meta (1201)boundaries, while the para (1801)-boundaries are not detected. Regions close to the boundaries are often modulated with periodicities of the adjacent domains, confirming that the boundaries in neighboring Te–Nb–Te triple layers do not necessarily coincide. r 2002 Elsevier Science B.V. All rights reserved.

Covering a light-emitting diode (LED) with quantum dots (QDs) can produce a broad spectrum of white light. However, current techniques for applying QDs to LEDs suffer from a high density of defects and a non-uniform distribution of QDs, which respec-tively diminish the efficiency and quality of emitted light. Oak Ridge National Laboratory (ORNL) has the unique capability to thermally anneal QD structures at extremely high power densities for very short durations. This process, called pulse thermal proc-essing (PTP), reduces the number of point defects while main-taining the size and shape of the original QD nanostructure. Therefore, the efficiency of the QD wavelength conversion layer is improved without altering the emission spectrum defined by the size distribution of the quantum dot nanoparticles. The cur-rent research uses a thermal model to predict annealing tempera-tures during PTP and demonstrates up to a 300% increase in pho-toluminescence for QDs on passive substrates

For streamflow forecasting applications, rainfall–runoff hydrological models are often augmented with updating procedures that correct streamflow predictions based on the latest available observations of streamflow and their departures from model simulations. The most popular approach uses autoregressive (AR) models that exploit the "memory" in hydrological model simulation errors. AR models may be applied to raw errors directly or to normalised errors. In this study, we demonstrate that AR models applied in either way can sometimes cause over-correction of predictions. In using an AR model applied to raw errors, the over-correction usually occurs when streamflow is rapidly receding. In applying an AR model to normalised errors, the over-correction usually occurs when streamflow is rapidly rising. Furthermore, when parameters of a hydrological model and an AR model are estimated jointly, the AR model applied to normalised errors sometimes degrades the stand-alone performance of the base hydrological model. This is not desirable for forecasting applications, as predictions should rely as much as possible on the base hydrological model, and updating should be applied only to correct minor errors. To overcome the adverse effects of the ordinary AR models, a restricted AR model applied to normalised errors is introduced. The new model is evaluated on a number of catchments and is shown to reduce over-correction and to improve the performance of the base hydrological model considerably.

It has been proposed that physical activity moderates physiological or psychological responses to chronic conditions. The purpose of this study was to determine if women with a chronic functional gastrointestinal (GI) disorder, irritable bowel syndrome, had less active lifestyles than healthy controls and to test whether active women with irritable bowel syndrome had less severe recalled or daily reports of GI, psychological, and somatic symptoms than inactive women with irritable bowel syndrome. Questionnaires were used to measure GI and psychological distress and somatic symptoms in 89 women who participated in this study. A daily symptom and activity diary was kept for one menstrual cycle. Women with irritable bowel syndrome were significantly less likely to be active (48%) than control women (71%) (X2 = 3.4, p = .05). Within the irritable bowel syndrome group, active women were less likely to report a feeling of incomplete evacuation following a bowel movement than inactive women (p < .04), yet active women did not have less severe recalled psychological or somatic symptoms than inactive women. Active women with irritable bowel syndrome reported less severe daily somatic symptoms, which were accounted for by a lower level of fatigue (p = .003), but not daily GI or psychological symptoms. These results suggest that physical activity may produce select symptom improvement in women with irritable bowel syndrome.

A series of intercalated transition-metal dichalcogenides with nominal compositions AxNbCh2, with A=Cu, Co, Fe, Ch=S, Se and x=0.25, 0.33, were studied by scanning tunneling microscopy (STM). Evidence is given that intercalation influences the STM images. Intercalated Cu atoms occupy tetrahedral interstices in the van der Waals gaps, forming pairs with Nb atoms and adopting the 2Hb–MoS2 stacking of the host structure. Effects associated with non-stoichiometry, such as formation of agglomerates and incomplete ordering of the intercalated Cu are frequently observed. Fe and Co atoms occupy octahedral interstices in the gaps, form chains with alternating Nb and stabilize the 2Ha–NbS2 polytype. In case of (Fe,Co)xNbS2 2a0×2a0 and √3a0×√3a0 hexagonal superstructures are formed for x=1/4 and x=1/3, respectively, while in case of CuxNb(S,Se)2 only the x=1/4 fraction orders into a 2a0×2a0 hexagonal superstructure at room temperature. In all cases the superstructures are visible at the surfaces and are attributed to changes in the local densities of states caused by a charge transfer between the intercalated and the surface atoms. Typically these superstructures were observed to change during prolonged scanning, probably as a result of tip-induced fluctuations in the charge density. The experimental STM images are compared to simulated images calculated with the extended Huckel tight binding approximation.

The quasi-two-dimensional compound ${\mathrm{NbSe}}_{2}$ was studied by scanning tunneling microscopy. Small domains of a $\sqrt{13}{a}_{0}\ifmmode\times\else\texttimes\fi{}\sqrt{13}{a}_{0}$ superstructure, forming an angle of about $\ifmmode\pm\else\textpm\fi{}14\ifmmode^\circ\else\textdegree\fi{}$ with the average structure, were observed at the edges of some surface defects. The superstructure is unstable and disappears gradually during scanning under the influence of the strong local field between the tip and the sample. It is attributed to a modulation analogous to those known in other ${d}^{1}$ transition-metal dichalcogenides ${\mathrm{MX}}_{2}$ with octahedrally coordinated X-M-X layers. It is assumed to be triggered by a local nonstoichiometry, which transforms the trigonal prismatic 2H stacking into the octahedral 1T one.

The family of crystals Nb 3 X 4 ( X =Te,Se,S) are isostructural, quasi one-dimensional tunnel structures. The telluride exhibits a charge density wave below room temperature, but no such transition occurs in the selenide or sulfide. A variety of foreign atoms can be intercalated into the tunnels of these structures and it is known that thallium intercalation in Nb 3 Te 4 causes dramatic changes in the charge density wave characteristics, due to changes in the Fermi surface and density of states resulting from the electrons being transferred to the host crystal from the intercalated atoms. In this paper it is shown that indium intercalation in Nb 3 Se 4 and Nb 3 S 4 gives rise to superlattice reflections in electron diffraction patterns, which are interpreted as being due to charge density waves. The unusual variations of the charge density wave vectors with intercalate concentration are discussed and a model to account for them is proposed.

The room-temperature modulated structure of ${\mathrm{NbTe}}_{4}$ was studied by means of scanning tunneling microscopy. In addition to a relatively weak image of the average structure and stronger contrast from the incommensurate modulation, contributions from domains of nanometer sizes were detected, which appeared with variable amplitudes. The existence of secondary modulation displacements associated with precursor effects of modulation phase transitions was suggested earlier on the basis of electron-diffraction results and their computer simulation. The current results are direct evidence of these fine-scale modulation phenomena.

Tunnel structures, into which a variety of atoms can be intercalated, offer a promising approach for investigation of the interaction between charge-density waves (CDW{close_quote}s) and foreign atoms. For this purpose single crystals of Tl{sub x}Nb{sub 3}Te{sub 4} with 0{le}x{le}1 were prepared. CDW{close_quote}s were observed below room temperature for all crystals, despite the wide range of Tl content. The wave vectors were determined by electron diffraction and the transition temperatures by resistivity measurements. For x{lt}0.25 the transition temperatures were less than those of the pure material, while for x{gt}0.25 both the transition temperatures and wave vectors increased strongly and passed through a maximum near x=0.75. The results were interpreted in terms of the crystal structure and the variation of the electron density of states at the Fermi level, as additional electrons were contributed to the host crystal with increasing Tl content. This is an example of a quasi-one-dimensional, inorganic system in which the transition temperature and CDW vector can be conveniently tuned by adjustments of the intercalate content. {copyright} {ital 1997} {ital The American Physical Society}

Skilful forecasts of high streamflows a month or more in advance are likely to be of considerable benefit to emergency services and the broader community. This is particularly true for small-medium sized catchments (< 2000km2), where real-time warning systems are only able to give short notice of impending floods. In this study, we generate forecasts of high streamflows for the coming 1 month and coming 3 month periods using large-scale ocean/atmosphere climate indices and catchment wetness as predictors. Forecasts are generated with a combination of Bayesian joint probability modeling and Bayesian model averaging. High streamflows are defined as maximum single-day streamflows and maximum 5 day streamflows that occur during each 1 month or 3 month forecast period. Skill is clearly evident in the 1 month forecasts of high streamflows. Surprisingly, in several catchments positive skill is also evident in forecasts of large threshold events (exceedance probabilities of 25%) over the next month. Little skill is evident in forecasts of high streamflows for the 3 month period. We show that including climate indices as predictors adds little skill to the forecasts, and thus catchment wetness is by far the most important predictor. Accordingly, we recommend that forecasts may be improved by using accurate estimates of catchment wetness.

We describe a procedure for producing thin-film TEM specimens containing a thickness and/or composition gradient, utilizing an out-of-contact mask at an appropriate distance from the substrate. Imaging and diffraction capabilities of the TEM are used to examine the local structure of the film; EELS or EDX analysis provides the local elemental composition. The procedure is illustrated by results obtained from two binary-alloy systems: Se–Te (which displays a complete range of solid solubility) and Sn–Ge (where mutual solubility is very low).

Phases and phase transitions in the system Ta1-xNbxTe4 are studied for three compositions (x=0, 0.25, 0.5). The various phases are characterized by commensurate and/or incommensurate satellite reflections; the intensity variation of these satellites is analysed and critical exponents are determined: they characterize the type of transition. A tentative phase diagram is proposed.

A brief description of the competing mechanisms important for the stability of composition- and temperature-dependent modulation phases of Nb 1− x Ta x Te 4 is given, with some emphasis on the microstructural changes at the two high temperature phase transitions in TaTe 4 . The charge density wave sliding in NbSe 3 is explained on the basis of a structural model which takes into account the easy switching between the two modulation wavevectors along the same trigonal prismatic columns. The dependence of the interpolytypic transitions and various charge density wave transition temperatures on the amount of intercalated Ag in 1T-TaS 2 is discussed.

CuIn x Ga 1−x Se 2 (CIGS) as an absorber material in solar cells is already known to present a less toxic alternative to current solar cells based on toxic elements such as CdTe. CIGS developed as nanoparticles in solution are ideal for non-vacuum deposition methods which help achieve lower-cost solar cells, compared to high vacuum deposition methods. This study investigates deposition, processing, and characterization of aqueous-based CIGS nanoparticles. The films are deposited via sono-deposition, spin coating method, and drop cast method. The as-deposited thin films are characterized via X-Ray Diffraction (XRD), Optical Microscope, and Scanning Electron Microscopy (SEM, and STEM). The films are then annealed via Pulsed Thermal Processing (PTP) technique, and post-PTP characterization shows change in the morphology of CIGS nanoparticles.

The expression of the hematopoietic transcription factors GATA-1, GATA- 2, and GATA-3 was studied in eosinophils and basophils. Eosinophils express mRNA for GATA-1, GATA-2, and GATA-3. Basophils express GATA-2 and GATA-3. Treatment of HL-60 eosinophilic sublines with either interleukin-5 or butyric acid increased the expression of GATA-1 mRNA concomitant with the expression of eosinophil-specific genes, whereas levels of GATA-2 mRNA remained relatively constant. The presence of mRNA for these proteins in eosinophils and basophils suggests that gene transcription in these lineages may be regulated by GATA-binding proteins.

We have isolated and sequenced a 598-bp full length cDNA clone for the human Charcot-Leyden crystal (CLC) protein (eosinophil lysophospholipase), the unique and prominent constituent of human eosinophils and basophils that forms the hexagonal bipyramidal crystals classically observed in tissues and secretions from sites of eosinophil-associated inflammation. A 426-bp open reading frame encoded a 142-amino acid polypeptide with a predicted molecular mass of 16.5 kDa and isoelectric point of 7.28. The deduced amino acid sequence of CLC protein showed 20 to 30% similarity over regions of approximately 100 amino acids with the carboxyl-terminal domains of four IgE-binding proteins, including the 31-kDa human and rat IgE-binding proteins, the 35-kDa mouse carbohydrate binding protein (CBP35), Mac-2, the murine macrophage cell surface protein that is identical to CBP35, and the human homologue of Mac-2. These proteins are members of a superfamily of beta-galactoside binding S-type animal lectins, which includes a group of highly conserved 14-kDa lectins isolated from human lung, heart, placenta, bovine heart, chicken skin, mouse fibroblasts, and the electric organ of the electric eel; CLC protein also showed sequence similarities to these 14-kDa animal lectins, including conservation of 7 of 16 invariant amino acid residues thought to comprise the carbohydrate-binding domain of these proteins, with conservative amino acid changes at others; thus, CLC protein could potentially possess carbohydrate or IgE-binding activities. Northern analyses revealed an approximately 900-bp mRNA species that was present in peripheral blood eosinophils from patients with eosinophilia, basophils from patients with chronic myelogenous leukemia, and in HL-60 cells induced towards eosinophilic differentiation with B cell growth factor-II (IL-5) or granulocytic differentiation with DMSO, but was absent in neutrophils, monocytes, T cells, B cells, or HL-60 cells induced towards monocytic differentiation with vitamin D3. Southern analyses revealed a gene of approximately 5 to 6 kb in length. The cDNA clone and complete amino acid sequence data for CLC protein will facilitate structure-function analyses of its unusual hydrophobic properties, unique propensity for crystallization, lysophospholipase, and potential lectin-like activities.

High-resolution, spatially-resolved x-ray Laue patterns and high-resolution light beam induced current (LBIC) measurements are combined to study two multicrystalline solar cells made from the Heat Exchanger Method (HEM) and the Sting Ribbon Growth technique. The LBIC measurements were made at 4 different wavelengths (488, 633, 780, and 980 nm), resulting in penetration depths ranging from 100 µm. There is a strong correlation between the x-ray and LBIC measurements, showing that some twins and grain boundaries are effective in the reduction of local quantum efficiency, while others are benign.

A series of displacively modulated mixed crystals Ta1-xNbxTe4 (0

In many ways, TaTe4 and NbTe4 are nearly prototypical compounds for the study of charge-density waves (CDW). The compounds have a quasi-one-dimensional crystal structure in which chains of metal atoms are centered within extended cages of Te atoms in square antiprismatic coordination. The observed lattice distortions, involving mainly longitudinal motions of the metal atoms along the chains, correspond to that of the classic CDW model. In addition, the compounds exhibit the full spectrum of possible CDW-driven phase transitions: commensurate-to-incommensurate (C to IC), C to C and IC to IC. The subcell of TaTe4 is tetragonal with axes (a x a x c). At room temperature, the crystal is commensurately modulated giving rise to a supercell with axes (2a x 2a x 3c) and, upon heating, has been observed to undergo a C to C transition at about 450 K. In this paper, we report an additional C to IC transition occurring above 550 K. The evolution of the microstructure upon heating, including the formation of discommensuration arrays in the IC state, has been revealed by satellite dark-field (SDF) imaging.

Superconductivity has been observed in originally semiconducting ceramic samples of La{sub 2}CuO{sub 4} following oxidation in an electrochemical cell at room temperature. After processing, the room-temperature resistivity is lowered by over an order of magnitude and, on cooling below 150 K, acquires a metallic temperature dependence. The superconducting transition occurs near 45 K. Magnetic-susceptibility measurements confirm the bulk nature of the superconductivity. Furthermore, by reversing the polarization of the cell, semiconducting La{sub 2}CuO{sub 4} can again be produced. The homogeneity of the processed samples was verified by x-ray powder diffraction and energy-dispersive x-ray elemental analysis.

The notion that hostile feelings can be catharted from the psyche by playing football or other aggressive sports was virtually destroyed by behavioral scientists several decades ago. Nonetheless educators continue to support interscholastic football as a means of venting the aggressive emotions that supposedly characterize adolescence. This work examines this phenomenon, concluding that educators realize the sport actually increases aggression but hide behind the outdated hypothesis about catharsis to perpetuate the sport—an activity which gives them much pleasure.

The resistivity and Tc of Bi2Sr2CaCu2O8+δ can be reversibly modified at room temperature using an electrochemical cell. Whereas reducing with up to 0.02 mole fraction of charge enhances the Tc systematically from about 73 K to 88 K, further reduction decreases the Tc again and eventually goes on to suppress superconductivity altogether. Above 0.10 mole fraction ϱ(T) loses its metallic character and assumes a negative slope which, above 0.50 mole fraction, can be modeled in terms of a semiconductor with an activation energy of 30 ± 2 meV. Oxidizing the latter material restores superconductivity, albeit the reversibility is not complete. Electrochemical and EDX data are compatible with the reversible solid state diffusion of copper; we propose that copper is intercalating.

The cheerleader is a common sight at American scholastic sports events. Her apparent purpose is to generate enthusiasm among the spectators to spur her school's team on to victory. However, while many handbooks and manuals exist on the mechanics of cheerleading, how the cheerleader is presented to peers and adults and whether she performs any latent function beyond her manifest one has rarely been examined. Cheerleading would not exist if educators did not approve of its supposed mission; thus it may be assumed that educators feel some benefit exists, be it to themselves, the girls, the school, or the community at large. This article addresses the cheerleader's role and effect in the secondary school, and whether enthusiasm for the school and its athletics is the sole purpose of cheerleading. When organized cheerleading began at the University of Minnesota in the 1890s, its practice was restricted to males. It was not until some forty years later that the question of allowing female cheerleaders was seriously discussed (Gach 1938). Today, cheerleading has evolved into primarily a practice for girls and women. This discussion is therefore not concerned with males, or with the few cheerleaders in elementary schools. Because little formal analysis has been performed, information must be gleaned largely from popular sources and interviews. Cheerleading is widely regarded as a glamorous, exciting activity through which a girl may become a highly acclaimed school socialite. The cheerleader wears her uniform in the classroom, flaunting her success in a way that no other girl may-the leading female in the school play does not wear her costume off

The hypothesis that siblings fight simply to attract adults' attention has enjoyed much speculation and some study of children's fighting in recent years. Current research indicates that refusing to intervene causes fighting to wane, supposedly because children will adequately solve problems by themselves if left to do so. The phenomenon of learned helplessness, in which lethargy and despair result from an inability to escape pain, has been applied to battered spouses. This work tests the hypothesis that nonintervention into siblings' fighting is more likely to allow one child to establish superiority over another and that fighting stops because the defeated learns helplessness in the manner of an abused spouse. Implications and alternative methods of dealing with fighting are explored.

Deuteron T1 and T2 was studied as a function of hydration in homopolyglycine (PG) and homopolyproline (PP). Water deuteron relaxation rates in PG conform to a hydration model involving two types of primary hydration sites where water is directly bonded to the polymer. Once these sites are filled, additional water only bonds to water molecules at the primary sites and in so doing affect their dynamics. PP exhibits an anomalous T1 and T2 hydration dependence which has been interpreted in terms of a cooperative water molecule–PP molecule helical conformational rearrangement which occurs once a certain hydration level is reached. The proposal of a water–PP structure is tested using molecular dynamics simulations. © 2007 Wiley Periodicals, Inc. Biopolymers 86: 11–22, 2007. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com

If one were to ask most anyone what engineers do, they would say “solve problems.” And indeed, engineers do [but I would suggest that all people solve problems regardless of their chosen careers]. What are less obvious are [a] whether engineering students and graduates are effective problem solvers; [b] whether engineering education is facilitated effectively as a “problem to be solved” and [c] whether that engineering education intentionally facilitates the development by students of an effective problem solving approach. In this paper, it is argued that instructors use of effective problem solving in course development, preparation, and facilitation must include the explicit attention to the student development of effective problem solving procedures. In this paper, it is argued that students will become more effective problem solvers if instructors encourage them to use procedures that embrace ambiguity and if instructors more consistently expect them to apply the procedures to open-ended problems throughout the curriculum. As students move from well-defined problem solving to more complex problem solving, they will benefit from one general and effective problem-solving procedure that is sufficiently flexible to include the various and more specific procedures that students will encounter. With career paths continually evolving and with information generation growth ever expanding, such skills are absolutely critical to success, again regardless of career choice.Copyright © 2007 by ASME