Sensitivity of ENSO characteristics to a new interactive flux correction scheme in a coupled GCM

A fast coupled global climate model (CGCM) is used to study the sensitivity of El Niño Southern Oscillation (ENSO) characteristics to a new interactive flux correction scheme. With no flux correction applied our CGCM reveals typical bias in the background state: for instance, the cold tongue in the tropical east Pacific becomes too cold, thus degrading atmospheric sensitivity to variations of sea surface temperature (SST). Sufficient atmospheric sensitivity is essential to ENSO. Our adjustment scheme aims to sustain atmospheric sensitivity by counteracting the SST drift in the model. With reduced bias in the forcing of the atmosphere, the CGCM displays ENSO-type variability that otherwise is absent. The adjustment approach employs a one-way anomaly coupling from the ocean to the atmosphere: heat fluxes seen by the ocean are based on full SST, while heat fluxes seen by the atmosphere are based on anomalies of SST. The latter requires knowledge of the model's climatological SST field, which is accumulated interactively in the spin-up phase ("training"). Applying the flux correction already during the training period (by utilizing the evolving SST climatology) is necessary for efficiently reducing the bias. The combination of corrected fluxes seen by the atmosphere and uncorrected fluxes seen by the ocean implies a restoring mechanism that counteracts the bias and allows for long stable integrations in our CGCM. A suite of sensitivity runs with varying training periods is utilized to study the effect of different levels of bias in the background state on important ENSO properties. Increased duration of training amplifies the coupled sensitivity in our model and leads to stronger amplitudes and longer periods of the Nino3. 4 index, increased emphasis of warm events that is reflected in enhanced skewness, and more pronounced teleconnections in the Pacific. Furthermore, with longer training durations we observe a mode switch of ENSO in our model that closely resembles the observed mode switch related to the mid-1970s "climate shift". © 2010 The Author(s)

Monte Carlo Hamiltonian of lattice gauge theory

We discuss how the concept of the Monte Carlo Hamiltonian can be applied to lattice gauge theories.Comment: "Non-Perturbative Quantum Field Theory: Lattice and Beyond", Guangzhou, China 200

Die Wertschöpfungskette unverpackter Lebensmittel Perspektiven und Herausforderungen

The concept of „unpackaged shopping“ aims at reducing waste along the entire value chain. Our project focusses on analysing the value chain of unpackaged food with regard to potentials, barriers and opportunities to expand the concept. The first results revealed that there are several challenges for “unpackaged shopping” to be observed, which can be grouped under six perspectives: supply, marketing, “inside”, “outside”, environment, and branch. For instance, the producers and suppliers are hesitant to change packaging processes due to a lack of demand, wholesalers are faced with potential additional cost for deposit systems, stores are having difficulties finding appropriate products and customers are struggling with the additional efforts of "unpackaged shopping". These challenges come along with cultural, social and psychological barriers such as changes in daily routines of delivery, selling and buying. Within the project solutions shall be developed that are compatible and feasible to all stages of the value chain

Аналитическое описание поверхностей зубьев эволютных передач

Зниження габаритів зубчастих передач є актуальною задачею сучасного машинобудування. Перспективний шлях її розв'язання – застосування еволютних передач із опукло-увігнутим контактом зубців. Отримані рівняння профілів еволютних зубців на основі методу профільних нормалей. Вони необхідні для подальших досліджень якісних показників та міцності еволютних зачеплень.Lowering of dimensions of gears is an actual task of a modern machine industry. The perspective way of its decision is application of evolute gears with the convax-concave contact. On the basis of method of type normal the equations of evolute teeth are got. They are needed for further researches of high-quality indexes and durability of evolute gearings

Origin of the large thermoelectric power in oxygen-variable RBaCo_{2}O_{5+x} (R=Gd, Nd)

Thermoelectric properties of GdBaCo_{2}O_{5+x} and NdBaCo_{2}O_{5+x} single crystals have been studied upon continuous doping of CoO_2 planes with either electrons or holes. The thermoelectric response and the resistivity behavior reveal a hopping character of the transport in both compounds, providing the basis for understanding the recently found remarkable divergence of the Seebeck coefficient at x=0.5. The doping dependence of the thermoelectric power evinces that the configurational entropy of charge carriers, enhanced by their spin and orbital degeneracy, plays a key role in the origin of the large thermoelectric response in these correlated oxides.Comment: 5 pages, 4 figures, accepted for publication in PR

The adsorption structure of furan on Pd(1 1 1)

The structure of molecular furan, C4H4O, on Pd(1 1 1) has been investigated by O K-edge near-edge X-ray absorption fine structure (NEXAFS) and C 1s scanned-energy mode photoelectron diffraction (PhD). NEXAFS shows the molecule to be adsorbed with the molecular plane close to parallel to the surface, a conclusion confirmed by the PhD analysis. Chemical-state specific C 1s PhD data were obtained for the two inequivalent C atoms in the furan, the α-C atoms adjacent to the O atom, and the β-C atoms bonded only to C atoms, but only the PhD modulations for the α-C emitters were of sufficiently large amplitude for detailed evaluation using multiple scattering calculations. This analysis shows the α-C atoms to be located approximately 0.6 Å off-atop surface Pd atoms with an associated C–Pd bondlength of 2.13 ± 0.03 Å. Two alternative local geometries consistent with the data place the O atom in off-atop or near-hollow locations, and for each of these local structures there are two equally-possible registries relative to the fcc and hcp hollow sites. The results are in good agreement with earlier density functional theory calculations which indicate that the fcc and hcp registries are equally probable, but the PhD results fail to distinguish the two distinct local bonding geometries

The determinants of urban household poverty in Malaysia

Since independence in 1950s Malaysia has been recognised as one of the more successful countries in fighting poverty: head count ratio came down to 5.7 percent by 2004. However the recent process of rapid urbanization has led to an increase of urban poverty aggravated further by the 1997 Asian financial crisis. It is important to understand the nature and scale of urbanization, the various driving forces that affect it and the determinants of urban poverty as linked to this process. Our paper identifies the determinants of urban poverty in Malaysia using a logistic regression. Multiple regression model which used to be the main tool of analysis in this kind of studies has been criticised for a number of drawbacks and binary probit or logit models have been proposed as alternative and widely used. Previous studies have used income to identify poor households. We have two problems with this procedure. First, the official poverty line in Malaysia is an consumption expenditure. Secondly data on household incomes are known to be less reliable than consumption data obtained from household expenditure surveys. We therefore compare a person’s consumption expenditure with the poverty line to determine its poverty status. This agrees with the idea that poverty is the inability to attain a critical minimum amount of consumption. We study the effect of human capital, region of residence and other household characteristics on urban poverty using this benchmark A sample of 2,403 urban households from the 2004-05 Household Expenditure Survey (HES) has been used in this research. We first estimate the probability of households with specified characteristics to fall below Malaysia’s official poverty line. Results show that human capital significantly reduces the chance of being poor while migrant workers are more prone to poverty. Household size, race and regions are also important determinants of poverty outcome in urban Malaysia. Then we analyse the sensitivity of the probability estimates to shift of the poverty line over a reasonable range. Effects of education, number of children, number of male adults, number of elderly, foreign migrant-headed household, Chinese household and households living in Region 1 on poverty are robust over the shifts. The findings have important policy implications for Malaysian government which has pledged to reduce overall poverty rate to 2.8 percent and eradicate hardcore poverty by 2010 under the Ninth Malaysian Plan

Defect distribution in a-plane GaN on Al2O3

The authors studied the structural and point defect distributions of hydride vapor phase epitaxial GaN film grown in the [11−20] a direction on (1−102) r-plane sapphire with metal-organic vapor phase deposited a-GaN template using transmission electron microscopy, secondary ion mass spectrometry, and positron annihilation spectroscopy. Grown-in extended and point defects show constant behavior as a function of thickness, contrary to the strong nonuniform defect distribution observed in GaN grown along the [0001] direction. The observed differences are explained by orientation-dependent and kinetics related defect incorporation.Peer reviewe

A structural study of a C3H3 species coadsorbed with CO on Pd(1 1 1)

The combination of chemical-state-specific C 1s scanned-energy mode photoelectron diffraction (PhD) and O K-edge near-edge X-ray absorption fine structure (NEXAFS) has been used to determine the local adsorption geometry of the coadsorbed C3H3 and CO species formed on Pd(1 1 1) by dissociation of molecular furan. CO is found to adopt the same geometry as in the Pd(1 1 1)c(4 × 2)-CO phase, occupying the two inequivalent three-fold coordinated hollow sites with the C–O axis perpendicular to the surface. C3H3 is found to lie with its molecular plane almost parallel to the surface, most probably with the two ‘outer’ C atoms in equivalent off-atop sites, although the PhD analysis formally fails to distinguish between two distinct local adsorption sites