Nature of the Oxygen Species at Ni(110) and Ni(100) Surfaces Revealed by Exposure to Oxygen and Oxygen-Ammonia Mixtures: Evidence for the Surface Reactivity of O- Type Species

Adsorption of dioxygen at clean Ni(110) and Ni(100) surfaces gives rise to two prominent features in the O(1s) spectra at 530 and 531 eV due to O2- and O- type species, respectively. Interaction of ammonia with a Ni(100)-O surface where theta(oxygen) < 0.1 ML favors the dissociation of NH3 giving NHn, (n = 1, 2) and N(a) species. This is accompanied by a decrease in the intensity of the 531 eV feature. On the other hand. a Ni(100)-O surface where the oxygen species are mainly of the O2- type is unreactive, Coadsorption studies of NH3-O-2 mixtures show that at Ni(110) surfaces the uptake of both oxygen and ammonia increase with the proportion of oxygen in the NH3-O-2 mixture. The surface concentrations of the O- species and the NHn species also increase with the increase in the O-2/NH3 ratio while the slope of the plot of sigma(N) versus sigma(O-) is around unity. The results demonstrate the high surface reactivity of the O- species and its role in the dissociation of ammonia. Based on these observations, the possibility of the formation of a surface complex between ammonia and oxygen (specifically O-) is suggested. Results from vibrational spectroscopic studies of the coadsorption of NH3-O-2 mixtures are consistent with those from core-level spectroscopic studies.

Topology Optimization of Micromachined Structures with the Manufacturing Constraints of KOH Etching of (110) Silicon

The focus of this paper is on designing useful compliant micro-mechanisms of high-aspect-ratio which can be microfabricated by the cost-effective wet etching of (110) orientation silicon (Si) wafers. Wet etching of (110) Si imposes constraints on the geometry of the realized mechanisms because it allows only etch-through in the form of slots parallel to the wafer's flat with a certain minimum length. In this paper, we incorporate this constraint in the topology optimization and obtain compliant designs that meet the specifications on the desired motion for given input forces. Using this design technique and wet etching, we show that we can realize high-aspect-ratio compliant micro-mechanisms. For a (110) Si wafer of 250 µm thickness, the minimum length of the etch opening to get a slot is found to be 866 µm. The minimum achievable width of the slot is limited by the resolution of the lithography process and this can be a very small value. This is studied by conducting trials with different mask layouts on a (110) Si wafer. These constraints are taken care of by using a suitable design parameterization rather than by imposing the constraints explicitly. Topology optimization, as is well known, gives designs using only the essential design specifications. In this work, we show that our technique also gives manufacturable mechanism designs along with lithography mask layouts. Some designs obtained are transferred to lithography masks and mechanisms are fabricated on (110) Si wafers.

Dielectric properties of (110) oriented PbZrO3 and La-modified PbZrO3 thin films grown by sol-gel process on Pt(111)/Ti/SiO2/Si substrate

Highly (110) preferred orientated antiferroelectric PbZrO3 (PZ) and La-modified PZ thin films have been fabricated on Pt/Ti/SiO2/Si substrates using sol-gel process. Dielectric properties, electric field induced ferroelectric polarization, and the temperature dependence of the dielectric response have been explored as a function of composition. The Tc has been observed to decrease by ∼ 17 °C per 1 mol % of La doping. Double hysteresis loops were seen with zero remnant polarization and with coercive fields in between 176 and 193 kV/cm at 80 °C for antiferroelectric to ferroelectric phase transformation. These slim loops have been explained by the high orientation of the films along the polar direction of the antiparallel dipoles of a tetragonal primitive cell and by the strong electrostatic interaction between La ions and oxygen ions in an ABO3 perovskite unit cell. High quality films exhibited very low loss factor less than 0.015 at room temperature and pure PZ; 1 and 2 mol % La doped PZs have shown the room temperature dielectric constant of 135, 219, and 142 at the frequency of 10 kHz. The passive layer effects in these films have been explained by Curie constants and Curie temperatures. The ac conductivity and the corresponding Arrhenius plots have been shown and explained in terms of doping effect and electrode resistance.

Temperature-pressure-induced solid-solid < 100 > to < 110 > reorientation in FCC metallic nanowire: a molecular dynamic study

Atomistic simulation of initial < 100 > oriented FCC Cu nanowires shows a novel coupled temperature-pressure dependent reorientation from < 100 > to < 110 > phase. A temperature-pressure-induced solid-solid < 100 > to < 110 > reorientation diagram is generated for Cu nanowire with varying cross-sectional sizes. A critical pressure is reported for Cu nanowires with varying cross-sectional sizes, above which an initial < 100 > oriented nanowire shows temperature independent reorientation into the < 110 > phase. The effect of surface stresses on the < 100 > to < 110 > reorientation is also studied. The results indicate that above a critical cross-sectional size for a given temperature-pressure, < 100 > to < 110 > reorientation is not possible. It is also reported here that for a given applied pressure, an increase in temperature is required for the < 100 > to < 110 > reorientation with increasing cross-sectional size of the nanowire. The temperature-pressure-induced solid-solid < 100 > to < 110 > reorientation diagram reported in the present paper could further be used as guidelines for controlling the reorientations/shape memory in nano-scale applications of FCC metallic nanowires.

Spatiotemporal chaos in a model for CO oxidation on Pt(110)

We present numerical studies of a model for CO oxidation on the surface of Pt(110) proposed in Ref. 1. The model shows several interesting regimes, some of which exhibit spatiotemporal chaos. The time series of the CO concentration at a given point consists of a sequence of pulses. We concentrate on interpulse intervals theta and show that their distribution P(theta) approaches a delta function continuously as the system goes from a state M, with meandering spirals, to a state S, with spatially frozen spiral cores. This should be verifiable experimentally.

k.p based closed form energy band gap and transport electron effective mass model for 100] and 110] relaxed and strained Silicon nanowire

In this paper, we address a physics based closed form model for the energy band gap (E-g) and the transport electron effective mass in relaxed and strained 100] and 110] oriented rectangular Silicon Nanowire (SiNW). Our proposed analytical model along 100] and 110] directions are based on the k.p formalism of the conduction band energy dispersion relation through an appropriate rotation of the Hamiltonian of the electrons in the bulk crystal along 001] direction followed by the inclusion of a 4 x 4 Luttinger Hamiltonian for the description of the valance band structure. Using this, we demonstrate the variation in Eg and the transport electron effective mass as function of the cross-sectional dimensions in a relaxed 100] and 110] oriented SiNW. The behaviour of these two parameters in 100] oriented SiNW has further been studied with the inclusion of a uniaxial strain along the transport direction and a biaxial strain, which is assumed to be decomposed from a hydrostatic deformation along 001] with the former one. In addition, the energy band gap and the effective mass of a strained 110] oriented SiNW has also been formulated. Using this, we compare our analytical model with that of the extracted data using the nearest neighbour empirical tight binding sp(3)d(5)s* method based simulations and has been found to agree well over a wide range of device dimensions and applied strain. (C) 2012 Elsevier Ltd. All rights reserved.

Micropropagacion de dos clones de caña de azucar (Saccharum sp.) ISA 96-110 e ISA 96-111

El presente estudio se realizó con el objetivo de desarrollar metodología para la micropropagación a partir de ápices caulinares, utilizando la técnica Spinder, y posteriormente aclimatación de las vitroplantas de dos clones de caña de azúcar (Saccharum sp.) (ISA 96-110 e ISA 96- 111). Se estudió el efecto que sobre el establecimiento tendrian 4 variantes del medio de cultivo MS (1962), suplidas con 0.0, 0.2 y 0.6 mg/1 de 6-BAP. Se utilizaron 15 réplicas por tratamiento. Se evaluó el efecto que sobre la brotación tuvieron 4 variantes del medio MS (1962), a las que se les adicionó 0.0, 0.1 y 0.5 mg/1 de 6 BAP durante tres subcultivos sucesivos. Se utilizaron 5 réplicas por variante en estudio. Para inducir el mayor enraizamiento se probaron 4 variantes líquidas del medio MS ( 1962), suplidas con 0.0, 1.0 y 1.6 mg/1 de AlA. Para el estudio de aclimatación se emplearon 30 plantas por cultivar y se establecieron en un sustrato de lombrices Californiana (Eisenia foetida). El clon ISA 96-110 presentó mayor porcentaje de fenolización y menor curvatura que el clon ISA 96-111. El medio de cultivo MS + 0.60 m g/1 de 6-BAP indujo al menor porcentaje de fenolización (33.0) y mayor de curvatura (60.0) en el clon ISA 96-110, el medio MS + 0.20 mg/1 de 6- BAP en el clon ISA 96-111. La sobrevivencia de las plantas del clon ISA- 111 fue de 100 % en todos los medios de cultivo, para el ISA 96-11O sólo los medios MS + 0.20 y MS + 0.00 mg/1 de 6-BAP. No hubo aumento de los valores de las variables altura de la planta, número de brotes y de hojas con el aumento del número de subcultivos. El medio de cultivo que indujo mayor brotación para el clon ISA 96-11 O fue el MS + 0.30 mg/1, mientras que para el clon ISA 96-111 fue el MS + 0.1 mg/1 de 6- BAP. El clon ISA 96-111 reportó resultados superiores en longitud (5.75 cm) y número de raices (7.4) por planta. El medio de cultivo MS + 1.3 mg/1 de AlA indujo los mejores resultados en ambos clones. El comportamiento de las plantas del clon ISA 96-1 11 fueron superiores a las del clon ISA 96-11O al momento de la aclimatación

Sapientia, 1973, Vol. XXVIII, nº 110 (número completo)

Contenido: La inmanencia, característica fundamental de la filosofía moderna y contemporánea / Octavio N. Derisi – La corrupción de lo natural en la civilización inmanentista / Alberto Caturelli – La participación de la inteligencia en la experiencia sensible / Mario Enrique Sacchi – Notas y comentarios -- Bibliografía

Quantum Monte Carlo study of the CO interaction with a dimer model surface for Cr(110)

The chemisorption of CO on a Cr( 110) surface is investigated using the quantum Monte Carlo method in the diffusion Monte Carlo (DMC) variant and a model Cr2CO cluster. The present results are consistent with the earlier ab initio HF study with this model that showed the tilted/ near-parallel orientation as energetically favoured over the perpendicular arrangement. The DMC energy difference between the two orientations is larger (1.9 eV) than that computed in the previous study. The distribution and reorganization of electrons during CO adsorption on the model surface are analysed using the topological electron localization function method that yields electron populations, charge transfer and clear insight on the chemical bonding that occurs with CO adsorption and dissociation on the model surface.

碱金属在[110]单轴应力下的理论强度

<正> 我们知道,晶须的强度远远大于大晶体的强度,很可能接近于理想晶体的理论强度.而晶须的轴线则通常平行于晶体的三个主要方向[100],[110]或[111]。因此当计算理想晶体在单轴应力下的理论强度时,也必须考虑不同的应力方向.七十年代,Milstein等人利用Morse势和Born稳定性判据计算了立方晶体分别在[100],[110]和[111]单轴应力下的理论强度.由于有心力近似受到Cauchy关系的限制,我们在文献

Contribuições sociais estabelecidas pela Lei Complementar nº 110/2001 : razão da instituição e continuidade de exigência

Já se passaram quase doze anos da instituição das contribuições sociais previstas nos arts. 1º e 2º da Lei complementar n. 110/2001. Tais contribuições visavam repor nas contas vinculadas do FGTS os complementos de atualização monetária devida aos trabalhadores em razão de expurgos inflacionários efetuados após a edição dos planos econômicos de janeiro de 1989 (Plano Verão) e de abril de 1990 (Plano Collor I). O presente estudo pretende avaliar se ainda persistem os fatores que justificaram a cobrança da contribuição prevista no art. 1º da referida Lei, em face das razões que justificaram a sua criação. Pela existência de indícios de que os valores recolhidos já atenderam ao seu pressuposto e, com o intuito de responder a essa indagação, a presente pesquisa buscou embasamento na legislação que dá origem ao instituto do FGTS, bem como sua evolução. Nessa ocasião, procurou-se apresentar os antecedentes históricos do Fundo, sua natureza jurídica, prescrição e outras considerações ao regime do FGTS. Teve, também, como fonte de pesquisa, literatura que discute, objetivamente, os expurgos inflacionários nas contas vinculadas do FGTS. Não foi desprezada dos objetos de estudo a jurisprudência dos tribunais superiores, onde foi possível perceber a dimensão que alcançaram as ações judiciais promovidas pelos trabalhadores. Outra fonte de pesquisa de significado relevante na elaboração deste trabalho diz respeito às Demonstrações Financeiras do FGTS somadas aos Relatórios de Gestão, ambos referentes aos exercícios de 2000 a 2011. Por meio desse instrumental, foi possível fazer uma análise do patrimônio do FGTS e identificar o reflexo das contribuições sociais em sua evolução, assim como verificar que o referido Fundo, no decorrer de 2012, já terá amortizado integralmente as despesas decorrentes do pagamento dos complementos de atualização monetária creditados nas contas vinculadas do FGTS. Na metodologia adotada, foram considerados, também, artigos publicados em revistas e em meio eletrônico, leis específicas sobre a matéria, Manual do FGTS e dispositivos constitucionais. Tudo isso, aliado ao método indutivo, favoreceu a aplicação da pesquisa na elucidação da questão em foco.

Diário da Constituinte [gravação de vídeo] : [programa n. 110]

As grandes cidades brasileiras estão inchadas e a superpopulação causa grandes problemas. Ibsen Pinheiro (PMDB-RS) diz que as regiões ricas são os "primos pobres" do nosso sistema tributário e que a nova Constituição deverá disponibilizar maiores recursos aos grandes centros urbanos para resolver e melhorar a vida de millhões de brasileiros. A Comissão de Ordem Econômica sugere dispositivos para acelerar a reforma urbana, sendo o primeiro deles o que ataca a especulação imobiliária sobre terras urbanas, com a criação de um imposto progressivo nas áreas não construídas e não usadas. Joaquim Bevilacqua (PTB- SP) defende a necessidade de iniciar uma economia de produtividade, em que o capital não seja especulativo, mas que contribua para o desenvolvimento social. Outro dispositivo é o que cria o usucapião urbano, que permite ao cidadão requerer o título de propriedade de uma área de até 250 m2 que ocupar por cinco anos. Gerson Marcondes (PMDB-SP) diz que a proposta atende grande parte das grandes cidades, onde existem não só as favelas, mas também os lotes populares, os loteamentos clandestinos e irregulares. Para evitar problemas urbanos é preciso acabar com o inchaço das cidades grandes e, por isso, os constituintes sugerem o estímulo à povoação de áreas vazias. Renato Bernardi (PMDB-PR) apresenta emenda que estimula o desenvolvimento de áreas pouco povoadas. Jovens a partir de dezesseis anos poderão votar (voto facultativo). Aécio Neves (PMDB-MG) promove campanha para que os jovens de dezesseis aos dezoito anos possam votar. Tito Costa (PMDB-SP) não crê que o cidadão de dezesseis anos esteja apto a votar e a ser votado. Airton Cordeiro (PDT-PR) opina que os jovens podem votar, sobretudo em uma sociedade que impõe a este jovem a necessidade de entrar no mercado de trabalho. Bernardo Cabral (PMDB-AM) entregará relatório da Comissão de Sistematização a Ulysses Guimarães, Presidente da Assembleia Nacional Constituinte (ANC).

Unconventional spin texture of a topologically nontrivial semimetal Sb(110)

9 p.