Granite desalination using electromigration. Influence of type of granite and saline contaminant

We describe the results of electromigration desalination of two soluble salt-contaminated Galician granites. The efficacy of electromigration, which had not been previously applied to granite, was assessed for two types of granite contaminated with a 20% NaCl solution and seawater. Desalination effectiveness was evaluated as follows: (1) analysis of anode and cathode ion content during testing; (2) analysis of ions at different distances from the electrodes after testing; (3) pH assessment of the stone surfaces; and (4) evaluation of colour changes. Results were very satisfactory; by the end of testing, chloride was reduced by almost 100% in both the NaCl and seawater contaminated samples. Sulfate reduction was also significant, despite this ion's lower mobility. The granite pH values remained close to neutral and colour changes were minimal. The difference in effectiveness of the process for the two types of stone was associated with their dissimilar pore structure.     

Key values of a Dutch cooperation school and the practice of religious education

This article presents the results of a single case study from a cooperation school in the Netherlands. A cooperation school is the result of a merger between a public and a denominational school. Pupils from secular and religious backgrounds meet in the classroom. This religious diversity in this school is explored by an empirical research study. The research question was how key values of the school and of its teachers are exerted in religious education. Content analysis of interviews and videos of the ‘moment of contemplation’ show that there is a discrepancy between the school values and the practice of this moment. Conclusions concerning a social and a substantive perspective are drawn in the light of theoretical insight concerning diversity in religious education.     

Teaching as a system: COVID-19 as a lens into teacher change

Educational Studies in Mathematics - In the spring of 2020, schools and universities around the world were closed because of the COVID-19 pandemic. The relative lockdown affected more than...     

Differences in pedalling technique between road cyclists of different competitive levels

The purpose of this study was to compare the pedalling technique in road cyclists of different competitive levels. Eleven professional, thirteen elite and fourteen club cyclists were assessed at the beginning of their competition season. Cyclists’ anthropometric characteristics and bike measurements were recorded. Three sets of pedalling (200, 250 and 300 W) on a cycle ergometer that simulated their habitual cycling posture were performed at a constant cadence (~90 rpm), while kinetic and kinematic variables were registered. The results showed no differences on the main anthropometric variables and bike measurements. Professional cyclists obtained higher positive impulse proportion (1.5–3.3% and P < 0.05), mainly due to a lower resistive torque during the upstroke (15.4–28.7% and P < 0.05). They also showed a higher ankle range of movement (ROM, 1.1–4.0° and P < 0.05). Significant correlations (P < 0.05) were found between the cyclists’ body mass and the kinetic variables of pedalling: positive impulse proportion (r = ?0.59 to ?0.61), minimum (r = ?0.59 to ?0.63) and maximum torques (r = 0.35–0.47). In conclusion, professional cyclists had better pedalling technique than elite and club cyclists, because they opted for enhancing pulling force at the recovery phase to sustain the same power output. This technique depended on cycling experience and level of expertise.     

Adolescents’ Friendships,Academic Achievement,and Risk Behaviors: Same-Behavior and Cross-Behavior Selection and Influence Processes

This study examined to what extent adolescents’ and their friends’ risk behaviors (i.e., delinquency and alcohol use) hinder or promote their academic achievement (grade point average [GPA]), and vice versa. Longitudinal data were used (N = 1,219 seventh- to ninth-grade adolescents; M_age = 13.69). Results showed that risk behaviors negatively affected adolescents’ GPA, whereas GPA protected against engaging in risk behaviors. Moreover, adolescents tended to select friends who have similar behaviors and friends’ behaviors became more similar over time (same-behavior selection and influence). Furthermore, although same-behavior effects seemed to dominate, evidence was found for some cross-behavior selection effects and a tendency in seventh grade for cross-behavior influence effects. Concluding, it is important to investigate the interplay between different behaviors with longitudinal social network analysis.     

Simulating Oppression: Digital Gaming,Race and the Education of African American Children

Educational game designers and educators are using digital games as a platform for teaching academic content, including multicultural curriculum. However, it is unclear how well digital game-based learning can coexist with the goals of multicultural education for the purpose of meeting the needs of African American children. In this essay, we raise serious questions about the use of digital games to teach about social oppression in ways that privilege the psychological well-being of African American children. We argue that digital games that intend to recreate histories of racial oppression can be harmful to African American children if they reproduce popular and problematic notions of indigenous lives and experiences. We illuminate some of the dangers of such digital games through a preliminary exploration of one digital game designed to teach about facets of African American enslavement. Our essay concludes with recommendations for culturally relevant digital game-based learning design and instruction.     

Real options theory,flexibility and the media industry

Abstract

This conceptual paper is based on two propositions: 1.) An efficient flexibility management is a critical success factor for media companies. 2.) The concept of real options theory (ROT) aims at improving a company's flexibility management. As a consequence, it is analysed how ROT can contribute to the flexibility management in media companies. In this context, two research issues are investigated. First, it is shown that real options as substantiations of flexibility are of great importance for media companies: In doing so, it is outlined that options which focus on a company's fixed costs management and options which aim at improving a company's sales situation are of high relevance for all segments in the media industry. Contrarily, options which focus on a company's variable costs are only relevant for media companies engaged in the print segment. Second, it is illustrated how ROT can contribute to the reactive and proactive management of flexibility in media companies.