School principals at their lonely work: Recording workday practices through ESM logs

This study used portable technology based on Experience Sampling Methodology (ESM log) to register workday practices of school principals and heads from Chilean schools who were implementing school improvement plans aimed at developing a culture of organizational learning. For a week, Smartphone devices which beeped seven times a day were given to School Principals and Heads of Technical-Pedagogical Units, who then answered closed questions about their current agenda. Six municipal schools in a district of the V Region of Chile participated in the study. The main results support the notion that, at the time of data collection, most school Principals and Heads of Technical-Pedagogical Units were working alone, and if they were interacting with other people, they were always in command. Following underlying assumed roles, most school principals reported performing administrative tasks, while Heads of Technical-Pedagogical Units mainly addressed instructional issues, fostering a rigid framework for the assignment of tasks. Follow-up semi-structured interviews confirmed that participants were not working as a team but rather alone on important issues and urgent matters. Participants regarded the use of the device as a very practical and useful tool to analyze their daily practices. Results are discussed focusing on the use of portable technology to address methodological issues faced when approaching research on educational leadership from a distributed leadership perspective.     

Deposition and photo-induced electrical resistivity of dip-coated NiO thin films from a precipitation process

Thin films of the semiconductor NiO are deposited using a straightforward combination of simple and versatile techniques: the co-precipitation in aqueous media along with the dip- coating process. The obtained material is characterized by gravimetric/differential thermal analysis (TG–DTA) and X-ray diffraction technique. TG curve shows 30 % of total mass loss, whereas DTA indicates the formation of the NiO phase about 578 K (305 °C). X-ray diffraction (XRD) data confirms the FCC crystalline phase of NiO, whose crystallinity increases with thermal annealing temperature. UV–Vis optical absorption measurements are carried out for films deposited on quartz substrate in order to avoid the masking of bandgap evaluation by substrate spectra overlapping. The evaluated bandgap is about 3.0 eV. Current–voltage (I–V) curves measured for different temperatures as well as the temperature-dependent resistivity data show typical semiconductor behavior with the resistivity increasing with the decreasing of temperature. The Arrhenius plot reveals a level 233 meV above the conduction band top, which was attributed to Ni²⁺ vacancy level, responsible for the p-type electrical nature of NiO, even in undoped samples. Light irradiation on the films leads to a remarkable behavior, because above bandgap light induced a resistivity increase, despite the electron–hole generation. This performance was associated with excitation of the Ni²⁺ vacancy level, due to the proximity between energy levels.     

Preparation of Phospholipid Multilayer Patterns of Controlled Size and Thickness by Capillary Assembly on a Microstructured Substrate

By dragging a phospholipid solution on microstructured silicon surfaces, phospholipid molecules are selectively deposited inside the microstructures to get regular phospholipid multilayer patterns of controlled thickness over a large scale (～cm²). By varying the dragging speed, the thickness of the patterns varies between 28 and 100 nm on average (7 to 25 bilayers). Electroswelling of phospholipid multilayer patterns leads to the formation of giant liposomes of controlled size and narrow size distributions.     

Evolution of railway network flexibility: The Spanish broad gauge case

The length of the Spanish broad gauge network has decreased in the 1956–2006 period. When looking at different railway maps through this period, it seems that the network is offering fewer and fewer alternatives when a line is cut, that is, the network is becoming less and less flexible. The goal of this article is to prove that the flexibility of the Spanish broad gauge network has decreased substantially in the 1956–2006 period. We have considered the network as a graph (ignoring traditional railway quality indicators such as commercial speed, number of tracks, electrifications, signaling, …) and we have chosen two simple indicators as accurate in this sense: the number of cycles (cycles provide an alternative to reach a station if there is a problem in one line) and the number of stations of intermediate degree. To achieve this, we have developed a piece of software that is an ad hoc extension of Maple’s networks package.     

Angiotensin-I converting enzyme inhibitory and antioxidant activities of protein hydrolysates from Phaseolus lunatus and Phaseolus vulgaris seeds

Phaseolus lunatus and Phaseolus vulgaris protein concentrates were hydrolyzed with the enzymes Alcalase^® and Flavourzyme^® at different reaction times, and the angiotensin-I converting enzyme (ACE-I) inhibitory activity, antioxidant properties and amino acid composition measured in the hydrolysates. With Alcalase^®, the highest degree of hydrolysis (DH) in P. lunatus was 37.94% at 45 min, and in P. vulgaris was 49.48% at 30 min. With Flavourzyme^®, the highest DH's were 22.03% and 26.05%, respectively, both at 90 min. ACE-I inhibitory activity in the Alcalase^® hydrolysates was IC₅₀ = 0.056 mg mL⁻¹ for P. lunatus at 90 min, and IC₅₀ = 0.061 mg mL⁻¹ for P. vulgaris at 60 min. In the Flavourzyme^® hydrolysates this activity was IC₅₀ = 0.0069 mg mL⁻¹ for P. lunatus at 90 min and IC₅₀ = 0.127 mg mL⁻¹ for P. vulgaris at 45 min. In SDS-PAGE, the hydrolysates exhibited low molecular weight bands. Antioxidant activity was 11.55 mmol L⁻¹ TEAC mg⁻¹ protein for P. lunatus with Flavourzyme^® at 90 min and 10.09 mmol L⁻¹ TEAC mg⁻¹ protein for P. vulgaris with Alcalase^® at 60 min. Amino acid composition exhibited high amino acid hydrophobic residues content.     

Evaluating the Utility of IPCC AR4 GCMs for Hydrological Application in South Korea

Understanding the uncertainty of climate models in space and time is necessary to help water resources managers and hydrologists in the selection of appropriate model for a specific application. In this paper, we use three separate methods to evaluate and compare the utility of 14 climate models for seven basins with area range of 2,656–26,355 km² on the South Korean Peninsula. On the one hand, the method of probabilistic uncertainty analysis is used to evaluate the capability of the studied General Circulation Models (GCMs) in recognizing the extreme events. On the other hand, we use two statistical tests (correlation coefficient and root mean square error) to examine the capability of the GCMs in simulating quantitatively each event. The results show that, for the first method, the performance of climate model varies depending on the number of climate model nodes used for a specific application of given basin, especially for monthly time scale. In addition, we find that, there are several GCMs showing good results for the probabilistic uncertainty test but poor results for the statistical test and conversely. Therefore, climate models should be evaluated for specific applications and specific regions. The results indicated quite clearly that, it is not easy to select an optimal climate model which can satisfy both applications using precipitation and temperature projections. However, the results of this study suggest that, there are several GCMs which are more useful than the others for general hydrological application in South Korean peninsula.     

PCB行业实施清洁生产取得的成效（2）——以汕头超声印制板（二厂）有限公司为例

汕头超声印制板（二厂）公司藉“节能减排”的契机，打破经验思维的束缚，把汕头超声印制板公司的成果和理念成功运用到本公司的清洁生产工作中，创造了良好的经济效益和环境效益。     

Experimental and Molecular Dynamics Simulations of Tribochemical Reactions with ZDDP: Zinc Phosphate–Iron Oxide Reaction

Zinc phosphate glass is considered to be the main constituent of tribofilms generated under boundary lubrication with zinc dialkyldithiophosphate (ZDDP), a well-known antiwear additive. The reaction occurring during friction between zinc phosphate glasses and steel native iron oxide layer is investigated by both an experimental approach and by Molecular Dynamics simulations (MD). The importance of this “tribochemical” reaction in the general ZDDP antiwear process is discussed.     

Synthesis, characterization and electrochemical properties of 4.8 V LiNi0.5Mn1.5O4 cathode material in lithium-ion batteries

In this work the synthesis of a nickel doped cubic manganese spinel has been studied for application as cathode material in secondary lithium batteries. Six different experimental approaches have been tested in order to carry out a screening of the various possible synthetic routes. The used synthetic strategies were wet chemistry (WC), solid state (SS), combustion synthesis (CS), cellulose-based sol-gel synthesis (SG-C), ascorbic acid-based sol-gel synthesis (SG-AA) and resorcinol/formaldehyde-based sol-gel synthesis (SG-RF). The goal of our study is to obtain insights about how the synthesis conditions can be modified in order to achieve a material with improved electrochemical performances in such devices, especially in high current operating regimes. The synthesized materials have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), atomic absorption, inductively coupled plasma (ICP-MS) atomic emission spectroscopy, surface area measurements and tested as high voltage cathodes in Li-ion electrochemical devices.