Mobile Phone Use among Market Traders at Fairs in Rural Peru

We characterize market traders at two rural fairs in Puno, Peru, based on quantitative and qualitative data gathered in 2008, to gain insight into types of traders and the information needs that influence the degree to which they use mobile phones to make decisions regarding which weekly fairs to attend. Using variables such as origin, type of goods sold, means of transportation to the market, and reliance on networks, we identify traders as full-time traders, part-time traders, or subsistence traders, that is, people trading solely to survive. We find that when traders are already familiar with the technology, regularly rely on endogenous networks to make decisions, and have more to lose from failing to trade (e.g., those selling perishable goods), they are more likely to use mobile phones to decide where to sell.

Numerical analysis of including phase change material in a domestic hot water cylinder

The domestic hot water cylinder incorporates encapsulated pcm placed in 57 vertical pipes. The use of PCM increases the thermal energy storage capacity of the cylinder and allows the use of low cost electricity during low peak periods. After experimental validation the numerical model developed in the project will be used to optimize the distribution of the pcm inside the water tank.

Material Market

El proyecto está basado en un sistema que denominaremos Material Market a lo largo de todo el trabajo. La idea que subyace detrás de este Market es un sistema que gestiona la compra-venta de materiales por parte de los usuarios del sistema.

Semantic Web applications: a framework for industry and business exploitation – What is needed for the adoption of the Semantic Web from the market and industry

In recent years, Semantic Web (SW) research has resulted in significant outcomes. Various industries have adopted SW technologies, while the ‘deep web’ is still pursuing the critical transformation point, in which the majority of data found on the deep web will be exploited through SW value layers. In this article we analyse the SW applications from a ‘market’ perspective. We are setting the key requirements for real-world information systems that are SW-enabled and we discuss the major difficulties for the SW uptake that has been delayed. This article contributes to the literature of SW and knowledge management providing a context for discourse towards best practices on SW-based information systems.

Post-market environmental monitoring of Bt maize in Spain: Non-target effects of varieties derived from the event MON810 on predatory fauna

The Spanish Government has established post-market environmental monitoring (PMEM) as mandatory for genetically modified (GM) crop varieties cultivated in Spain. In order to comply with this regulation, effects of Bt maize varieties derived from the event MON810 on the predatory fauna were monitored for two years in northeast and central Spain. The study was carried out with a randomized block design in maize fields of 3-4 ha on which the abundance of plant-dwelling predators and the activity-density of soil-dwelling predators in Bt vs. non-Bt near-isogenic varieties were compared. To this end, the plots were sampled by visual inspection of a certain number of plants and pitfall traps 6 or 7 times throughout two seasons. No significant differences in predator densities on plants were found between Bt and non-Bt varieties. In the pitfall traps, significant differences between the two types of maize were found only in Staphylinidae, in which trap catches in non-Bt maize were higher than in Bt maize in central Spain. Based on the statistical power of the assays, surrogate arthropods for PMEM purposes are proposed; Orius spp. and Araneae for visual sampling and Carabidae, Araneae, and Staphylinidae for pitfall trapping. The other predator groups recorded in the study, Nabis sp. and Coccinellidae in visual sampling and Dermaptera in pitfall trapping, gave very poor power results. To help to establish a standardized protocol for PMEM of genetically modified crops, the effect-detecting capacity with a power of 0.8 of each predator group is given.

European employment strategy and spanish labour market policies

The paper aim is to analyse the influence of the European Employment Strategy (EES)in the implementation of the Spanish labour market policies. The first part of the paper describes the evolution and content of the EES. In the second one, the definition of activation is also explained. In addition to that, the ways how the EES develops and promotes active labour market policies are examined. The evolution of labour market policies in Spain and the current configuration of both active and passive policies are studied in the next three chapters. In these parts, the paper investigates to which extent the provisions of the EES have been implemented in Spain. The paper shows that: i) activation has been rising in the European countries since the implementation of the EES; ii) this fact has also happened in relative terms (comparing the evolution of active to passive policies); iii) Spain has been one of the countries which has led these processes; iv) the EES seems to have been influencing

Progress in a-Si:H/c-Si heterojunction emitters obtained by Hot-Wire CVD at 200°C

In this work, we investigate heterojunction emitters deposited by Hot-Wire CVD on p-type crystalline silicon. The emitter structure consists of an n-doped film (20 nm) combined with a thin intrinsic hydrogenated amorphous silicon buffer layer (5 nm). The microstructure of these films has been studied by spectroscopic ellipsometry in the UV-visible range. These measurements reveal that the microstructure of the n-doped film is strongly influenced by the amorphous silicon buffer. The Quasy-Steady-State Photoconductance (QSS-PC) technique allows us to estimate implicit open-circuit voltages near 700 mV for heterojunction emitters on p-type (0.8 Ω·cm) FZ silicon wafers. Finally, 1 cm 2 heterojunction solar cells with 15.4% conversion efficiencies (total area) have been fabricated on flat p-type (14 Ω·cm) CZ silicon wafers with aluminum back-surface-field contact.

Investigation of defect formation and electronic transport in microcrystalline silicon deposited by hot-wire CVD

We have investigated doped and undoped layers of microcrystalline silicon prepared by hot-wire chemical vapour deposition optically, electrically and by means of transmission electron microscopy. Besides needle-like crystals grown perpendicular to the substrate's surface, all of the layers contained a noncrystalline phase with a volume fraction between 4% and 25%. A high oxygen content of several per cent in the porous phase was detected by electron energy loss spectrometry. Deep-level transient spectroscopy of the crystals suggests that the concentration of electrically active defects is less than 1% of the undoped background concentration of typically 10^17 cm -3. Frequency-dependent measurements of the conductance and capacitance perpendicular to the substrate surface showed that a hopping process takes place within the noncrystalline phase parallel to the conduction in the crystals. The parasitic contribution to the electrical circuit arising from the porous phase is believed to be an important loss mechanism in the output of a pin-structured photovoltaic solar cell deposited by hot-wire CVD.

Studies on grain boundaries in nanocrystalline silicon grown by Hot-Wire CVD

The use of a tantalum wire in hot-wire chemical vapour deposition (HWCVD) has allowed the deposition of dense nanocrystalline silicon at low filament temperatures (1550 °C). A transition in the crystalline preferential orientation from (2 2 0) to (1 1 1) was observed around 1700 °C. Transmission electron microscopy (TEM) images, together with secondary ion mass spectrometry (SIMS) measurements, suggested that no oxidation occurred in materials obtained at low filament temperature due to the high density of the tissue surrounding grain boundaries. A greater concentration of SiH 3 radicals formed at these temperatures seemed to be responsible for the higher density.

EMU sovereign debt market crisis: Fundamentals-based or pure contagion?

We empirically investigate whether the transmission of the recent crisis in euro area sovereign debt markets was due to fundamentals-based or pure contagion. To do so, we examine the behaviour of EMU sovereign bond yield spreads with respect to the German bund for a sample of both central and peripheral countries from January 1999 to December 2012. First we apply a dynamic approach to analyse the evolution of the degree of Grangercausality within the 90 pairs of sovereign bond yield spreads in our sample, in order to detect episodes of significantly increased causality between them (which we associate with contagion) and episodes of significantly reduced interconnection (which we associate with immunisation). We then use an ordered logit model to assess the determinants of the occurrence of the episodes detected. Our results suggest the importance of variables proxying market sentiment and of variables proxying macrofundamentals in determining contagion and immunisation outcomes. Therefore, our findings underline the coexistence of “pure” and “fundamentals-based contagion” during the recent European debt crisis.

EMU sovereign debt market crisis: Fundamentals-based or pure contagion?

We empirically investigate whether the transmission of the recent crisis in euro area sovereign debt markets was due to fundamentals-based or pure contagion. To do so, we examine the behaviour of EMU sovereign bond yield spreads with respect to the German bund for a sample of both central and peripheral countries from January 1999 to December 2012. First we apply a dynamic approach to analyse the evolution of the degree of Grangercausality within the 90 pairs of sovereign bond yield spreads in our sample, in order to detect episodes of significantly increased causality between them (which we associate with contagion) and episodes of significantly reduced interconnection (which we associate with immunisation). We then use an ordered logit model to assess the determinants of the occurrence of the episodes detected. Our results suggest the importance of variables proxying market sentiment and of variables proxying macrofundamentals in determining contagion and immunisation outcomes. Therefore, our findings underline the coexistence of “pure” and “fundamentals-based contagion” during the recent European debt crisis.

Hot wire configuration for depositing device grade nano-crystalline silicon at high deposition rate

The University of Barcelona is developing a pilot-scale hot wire chemical vapor deposition (HW-CVD) set up for the deposition of nano-crystalline silicon (nc-Si:H) on 10 cm × 10 cm glass substrate at high deposition rate. The system manages 12 thin wires of 0.15-0.2 mm diameter in a very dense configuration. This permits depositing very uniform films, with inhomogeneities lower than 2.5%, at high deposition rate (1.5-3 nm/s), and maintaining the substrate temperature relatively low (250 °C). The wire configuration design, based on radicals' diffusion simulation, is exposed and the predicted homogeneity is validated with optical transmission scanning measurements of the deposited samples. Different deposition series were carried out by varying the substrate temperature, the silane to hydrogen dilution and the deposition pressure. By means of Fourier transform infrared spectroscopy (FTIR), the evolution in time of the nc-Si:H vibrational modes was monitored. Particular importance has been given to the study of the material stability against post-deposition oxidation.

Progress in single junction microcrystalline silicon solar cells deposited by Hot-Wire CVD

Hot-Wire Chemical Vapor Deposition has led to microcrystalline silicon solar cell efficiencies similar to those obtained with Plasma Enhanced CVD. The light-induced degradation behavior of microcrystalline silicon solar cells critically depends on the properties of their active layer. In the regime close to the transition to amorphous growth (around 60% of amorphous volume fraction), cells incorporating an intrinsic layer with slightly higher crystalline fraction and [220] preferential orientation are stable after more than 7000 h of AM1.5 light soaking. On the contrary, solar cells whose intrinsic layer has a slightly lower crystalline fraction and random or [111] preferential orientation exhibit clear light-induced degradation effects. A revision of the efficiencies of Hot-Wire deposited microcrystalline silicon solar cells is presented and the potential efficiency of this technology is also evaluated.

Market Index Biases and Minimum Risk Indices

Markets, in the real world, are not efficient zero-sum games where hypotheses of the CAPM are fulfilled. Then, it is easy to conclude the market portfolio is not located on Markowitz"s efficient frontier, and passive investments (and indexing) are not optimal but biased. In this paper, we define and analyze biases suffered by passive investors: the sample, construction, efficiency and active biases and tracking error are presented. We propose Minimum Risk Indices (MRI) as an alternative to deal with to market index biases, and to provide investors with portfolios closer to the efficient frontier, that is, more optimal investment possibilities. MRI (using a Parametric Value-at-Risk Minimization approach) are calculated for three stock markets achieving interesting results. Our indices are less risky and more profitable than current Market Indices in the Argentinean and Spanish markets, facing that way the Efficient Market Hypothesis. Two innovations must be outlined: an error dimension has been included in the backtesting and the Sharpe"s Ratio has been used to select the"best" MRI

Optoelectronic studies in nanocrystalline silicon Schottky diodes obtained by Hot-Wire Chemical Vapour Deposition

The very usual columnar growth of nanocrystalline silicon leads to electronic transport anisotropies. Whereas electrical measurements with coplanar electrodes only provide information about the electronic transport parallel to the substrate, it is the transverse transport which determines the collection efficiency in thin film solar cells. Hence, Schottky diodes on transparent electrodes were obtained by hot-wire CVD in order to perform external quantum efficiency and surface photovoltage studies in sandwich configuration. These measurements allowed to calculate a transverse collection length, which must correlate with the photovoltaic performance of thin film solar cells. Furthermore, the density of charge trapped at localized states in the bandgap was estimated from the voltage dependence of the depletion capacitance of these rectifying contacts.