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An attempt to assess the impact of climate change on the agricultural sector in FYR Macedonia using an aridity index approach

Considering the scale of global warming, we make an attempt to assess theimpact of climate change on Macedonian agriculture. Farmers’ adaptation is taken into account by using an alternative specification of the Ricardian model based on the use of aridity indices to capture the non-linear response of farmland values to temperature and precipitation. Econometric results indicate that winter and spr

Dissuasive exit signage for building fire evacuation

This work presents the result of a questionnaire study which investigates the design of dissuasive emergency signage, i.e. signage conveying a message of not utilizing a specific exit door. The work analyses and tests a set of key features of dissuasive emergency signage using the Theory of Affordances. The variables having the largest impact on observer preference, interpretation and noticeabilit

Electrons, holes, and the hall effect in amorphous silicon

The double sign anomaly in hydrogenated amorphous silicon, observed by LeComber et.al. [1] in 1977, has remained puzzling ever since. Recently we attacked this problem from two different directions using the equation-of-motion method. Calculations reproduce the double sign anomaly and were rationalised in terms of the behaviour of the spectral function. In a new type of calculation the motion of a

New applications of the equation-of-motion method: Optical properties

The equation-of-motion method offers advantages in the calculation of properties of large structural models, of the kind recently developed for a-Si (104 or more atoms). Originally developed for calculating densities of states, it has been shown to be adaptable to a wide variety of other purposes, including the study of localization, conductivity and the Hall effect. Recently we have shown how it

The computation of linear and nonlinear optical constants of semiconductors

We review the problem posed by the calculation of the optical constants of solids and the adaptation of the equation-of-motion method for this purpose. In the past crystalline materials were studied by employing Bloch's theorem, but for amorphous materials and surfaces symmetry cannot generally be used to reduce the computation to manageable proportions. The equation-of-motion method avoids the ne

Optical properties studied using linear muffin-tin orbital theory

A new method is presented for calculating optical properties within the framework of the self-consistent linear muffin-tin orbital (LMTO) band-structure theory. We show how Green's second identity along with the commutation relation between the position and Hamiltonian operators may be used to calculate, independently of the gauge, the velocity matrix elements required for optical properties. The

Magnetism and magneto-structural effects in transition-metal sulfides

Recent density-functional studies of the structural and electronic properties of a wide range of transition-metal sulphides (Raybaud P, Kresse G, Hafner J and Toulhoat H 1997 J. Phys.: Condens. Matter 9 11085, 11 107) are extended to consider the effect of magnetic ordering in sulphides formed by 3d transition metals. We find that CrS is well described as an itinerant antiferromagnet and that the

Fully unconstrained non-collinear magnetism in triangular Cr and Mn monolayers and overlayers on Cu(111) substrates

A recently developed fully unconstrained approach to non-collinear magnetism has been applied to the investigation of the magnetic ground state of triangular free-standing Cr and Mn monolayers and overlayers on Cu(111) substrates. Such systems represent a physical realization of a frustrated two-dimensional antiferromagnet. We find that the ground state of the Cr monolayers is non-collinear; it sh

Ab initio density functional study of phase stability and noncollinear magnetism in Mn

The crystalline and magnetic structures of all known polymorphs of Mn have been investigated using generalized spin-density functional theory based on an unconstrained vector-field description of the magnetization density. We find that at atomic volumes smaller than 12 Å3, the magnetic ground state of α-Mn is collinear with magnetic moments ranging between 0 and 3 µB depending on the local symmetr

Approximate maximum likelihood estimation using data-cloning ABC

A maximum likelihood methodology for a general class of models is presented, using an approximate Bayesian computation (ABC) approach. The typical target of ABC methods are models with intractable likelihoods, and we combine an ABC-MCMC sampler with so-called "data cloning" for maximum likelihood estimation. Accuracy of ABC methods relies on the use of a small threshold value for comparing simulat

Applied Problems and Use of Technology in Basic Courses in Probability and Statistics : A Way to Enhance Understanding and Increase Motivation

Several authors have reported problems on service courses in basic probability and statistics: students may lack motivation, find the theory difficult or boring, others see no applications for the results. To remedy these problems we have developed a learning environment where two important components are applied problems and use of technology. However, the mere existence of applied problems and t

Fuktsäkra träkonstruktioner II : Vägledning för utformning av träbaserade takkonstruktioner

Rapporten avser att ge generella riktlinjer och exempel på hur fuktsäkra takkonstruktioner i trä kan byggas. En rad viktiga faktorer som påverkar fuktsäkerheten och risken för fukt- och mögelrelaterade skador presenteras. Rapporten avser även att fungera som ett verktyg och stöd för svenska trähustillverkare, statliga och kommunala tjänstemän som handlägger byggrelaterade ärenden samt byggherrar o

) Inhibition of anaerobic phosphate release by nitric oxide in activated sludge

Activated sludge not containing significant numbers of denitrifying, polyphosphate [poly(P)]-accumulating bacteria was grown in a fill-and-draw system and exposed to alternating anaerobic and aerobic periods. During the aerobic period, poly(P) accumulated up to 100 mg of P · g of (dry) weight. When portions of the sludge were incubated anaerobically in the presence of acetate, 80 to 90% of the int

Polyphosphate formation by Acinetobacter johnsonii strain 210A: effect of cellular energy status and phosphate-specific transport system

In acetate-limited chemostat cultures of Acinetobacter johnsonii 210A at a dilution rate of 0.1 h−1 the polyphosphate content of the cells increased from 13% to 24% of the biomass dry weight by glucose (100 mM), which was only oxidized to gluconic acid. At this dilution rate, only about 17% of the energy from glucose oxidation was calculated to be used for polyphosphate synthesis, the remaining 83