Halite – A new calibration material for microdrilling resistance measurements

This paper aims at proposing a new calibration material for microdrilling resistance measurements. Microdrilling resistance is a microdestructive method mainly used in built heritage in order to determine the strength profile in depth. This method is suitable to detect changes in the material cohesion, either due to a different state of preservation or to the action of a consolidant. Calibration materials are often used in microdrilling measurements in order to characterise the drill bit initial value and to correct the variations existing within the initial values of a set of drill bits. Calibration materials are also useful to detect the wear effect on a drill bit due to an abrasive stone. Moreover, such materials can be used for comparing results obtained with different microdrilling machines. In this work, halite was chosen to be tested as a calibration material due to its properties, as low hardness and isotropy. Halite single crystals and halite salt stone from different provenances were tested in order to evaluate the suitability of this material to the requests of a calibration material for microdrilling resistance applications, as for instance being homogeneous, non-abrasive, sensitive and available worldwide. Experimental results show that halite from different provenances is very homogeneous, especially in the crystalline form. This form of halite is slightly more expensive than stone halite; however its costs are comparable to ARS and significantly lower than Macor (other calibration materials commonly used for microdrilling resistance measurements). Due to the advantages of halite for calibration purposes, this material should be further tested by other authors in order to validate our conclusions.     

System learning in an urban school district: A case study of intra-district learning

This paper presents evidence from a unique reform model that allowed teachers and other educators in a large urban district to collaborate with one another in the development of an innovation meant to improve student ownership and responsibility. In this longitudinal case study, we describe school stakeholders’ learning about the design, the process of knowledge-transfer to school teams, and how school teams shared their ongoing learning with one another. School implementation teams were initially reluctant to share their learning with one another. By engaging in a shared innovation development process with structures for routine sharing, over time, implementation team members were increasingly interested in sharing their learning with one another. We discuss the implications for school improvement efforts.     

An analysis of three different approaches to student teacher mentoring and their impact on knowledge generation in practicum settings

Mentoring in Teacher Education is a key component in the professional development of student teachers. However, little research focuses on the knowledge shared and generated in mentoring conversations. In this paper, we explore the knowledge student teachers articulate in mentoring conversations under three different post-lesson approaches to mentoring: dialogue journaling, regular conferences and stimulated-recall conferences. Propositional discourse analysis identified 4534 propositions that were subsequently classified into four types of knowledge: recalls, appraisals, rules and artefacts along with the precision of arguments therein. Additionally, log-linear analyses were conducted to search for differences among the three mentoring approaches. The results indicate that dialogue journaling demonstrated more appraisals of practice, regular conferences emphasised rules and artefacts, and stimulated-recall favoured more precision in the type of the arguments stated. The three mentoring styles favour different but complementary understandings of practice and point to the impact of various approaches to mentoring on the sort of knowledge shared and generated in post-lesson mentoring conferences.     

With Scale in Mind: A Continuous Improvement Model for Implementation

The conventional approach to scaling up educational reforms considers the development and testing phases to be distinct from the work of implementing at scale. Decades of research suggest that this approach yields inconsistent and often disappointing improvements for schools most in need. More recent scholarship on scaling school improvement suggests that these activities should be integrated into implementation, although this presents challenges in how we evaluate implementation in particular schools. This paper presents a framework to conceptualize implementation when design, implementation, and scaling up are integrated activities.     

Technical replicas of Portuguese ceramic tile bodies produced in the Oporto region in the late nineteenth to early twentieth centuries

Portugal is well known for its facades decorated entirely with ornamented glazed ceramic wall tiles called azulejos. On ageing, the tiles may detach and fall off, or deteriorate to such an extent that it becomes necessary to replicate them. Hence tile replication is a common practice in Portugal for façade restoration, but very often these new tiles do not have the same physical and/or chemical properties as the original ones. Such differences might be a factor in differential deterioration of the façades after restoration. One step toward an improvement in compatibility is to make new ceramic bodies with the same characteristics as the original ones. This study focuses on two types of glazed ceramic wall tiles from the Oporto region in Portugal: ‘calcic faience’ and pó de pedra. A total of 25 samples from the late nineteenth to early twentieth centuries were studied systematically as an attempt to improve knowledge of these materials and to create a basis for their replication. All samples were collected from facades that were under conservation/restoration at the time when sampling was performed. The original traditional ceramic bodies were analyzed by X-ray diffraction and X-ray fluorescence. Total open porosity, capillary absorption coefficient, and mercury intrusion porosimetry were also measured in order to gain knowledge on their physical characteristics in addition to their chemical and mineralogical compositions. High-temperature crystalline phases such as diopside, gehlenite, and mullite were found in the calcic faience, suggesting that the firing temperature of calcic faience bodies was within the range of 1100–1150?°C. Calcination trials were also performed in order to determine the most probable firing temperatures of the ceramic bodies. Collected data led to the assumption that the raw materials used for the ceramic bodies were kaolinitic clay, quartz sand, limestone, and talc. The raw materials for pó de pedra tiles were found to include kaolinite clay and quartz with firing temperatures estimated within the temperature range of 1150–1360?°C. Technical replicas made on the basis of these investigations were found to have the same mineralogical and capillary properties as the original tiles.     

The link between executive functions and literacy: introduction

This special issue was born within the M2S Project (Mindfulness to students’ success: Relating executive functions and writing through a mindfulness app to promote children’s cognitive, social, and health-related outcomes) to call researchers and practitioners’ attention to the role that executive functions play on the acquisition and development of literacy skills, a neglected topic in the field. The selected papers include various methods and techniques to examine the relationships between literacy and executive functions across languages/cultures and different age groups, with and without disabilities.

     

Improving the acquisition and retention of science material by fifth grade students through the use of imagery interventions

This study examined the effect of imagery interventions for the presentation of novel science vocabulary to fifth grade learners. Eighty-nine students from two schools in Long Island participated in this study and were randomly assigned to four different instructional interventions: a Picture Presentation method, in which a word was paired with a picture; an Image Creation??No Picture method, in which the participants were told to create an image of the word and draw it on paper; an Image Creation??Picture method, in which the students were presented with the picture and then told to draw it; and a Word Only method, which involved the simple verbal presentation of the word. Results demonstrated that students in the imagery intervention groups (Picture Presentation, Image Creation??No Picture, and Image Creation??Picture) scored higher on the outcome measures at both immediate and delayed recall. It was also shown that the deeper the students processed the ??to be learned?? vocabulary words, the higher they scored on the outcome measures. Based on the mean outcome measure scores at both time points, students in the Image Creation??Picture intervention scored the highest, followed by the students in the Image Creation??No Picture intervention, those in the Picture Presentation intervention, and finally the Word Only intervention students. Such a study has implications as to the most effective way to integrate science and literacy and successfully present novel concepts in the classroom.     

School innovation in district context: Comparing traditional public schools and charter schools

Market reforms in education are part of the educational policy landscape in many countries. Central to arguments for market reforms is the idea that competition and choice will spur changes in schools to be more innovative, which in turn will lead to better student outcomes. We define innovation in terms of a practice's relative prevalence in a local district context. A charter school is innovative in its use of a practice if the traditional public schools in its local school district are not using that practice. We explore factors based on arguments for charter schools that may affect a charter schools’ propensity toward innovation to explain variation in levels of innovation across charter schools. We find that, on the whole, charter schools do not fulfill their promise of innovation. Teacher tenure is the most notable exception. Parental involvement is the only characteristic of charter schools that significantly predicts variation in levels of organizational innovativeness.