The limit analysis in soil and rock： a mature discipline of geomechanics

The solution of a slope stability problem can be approached by its least upper-bound and maximum lower-bound with high accuracy. The limit equilibrium methods that employ vertical slices imply a lower bound of the factor of safety. It has been successfully extended to the area of active earth pressure analysis that accounts for different input of locations of earth pressure applications. Those methods that employ slices with inclined interfaces give an upper-bound approach to the stability analysis. It enjoys a sound mechanical background and is able to provide accurate solutions of soil plasticity. It has been successfully extended to the area of bearing capacity analysis in which various empirical coefficients are no longer necessary. The 3D upper- and lower-bound methods under this framework have been made possible and show great potential for solving various engineering problems.     

Effects of slag fineness on durability of mortars

In recent years, the usages of by-products and wastes in industry have become more important. The importance of the sustainable development is also of increasing. The utilizations of wastes, as mineral admixture or fine aggregate, reduce the consumption of the natural resources and improve the durability of concrete. In this study, the effect of the fineness on the high temperature and sulphate resistances of concrete mortar specimens, produced with ground granulated blast-furnace slag (GBFS) replacing cement, is investigated. The compressive and flexural strength test results for all series related to durability effects, exposing temperature and solutions, exposure times for these durability effects, slag content and fineness are discussed. Conse- quently, the optimum slag contents are determined for producing the sulphate and high temperature resistant mortars.     

Research on the operating characteristics of parallel 4-DOF electric platform with 4TPS-PS structure

The 4TPS-PS parallel platform designed for a stabilization and automatic tracking system is a novel lower-mobility parallel mechanism. In the first part of this paper, the structure of the platform is described and the kinematics model is built. The workspace of the platform is defined as the full reachable rotation workspace when the Z coordinate dimension of the upper plate varies continuously. A fast searching method of the full reachable workspace is presented, after which the inverse kinematics of the platform is deduced. The forward and inverse solutions of the speed and force of the platform are deduced. According to the characteristic of the 4TPS-PS platform’s structure, a fast searching algorithm of the maximum generalized speed and maximum generalized force output by the upper plate is put forward based on the forward and inverse solutions of the platform’s speed and force. The 4TPS-PS platform prototype built by the State Key Laboratory of Fluid Power Transmission and Control of China is taken as the research subject. The full reachable rotation workspace of the prototype is computed out and analyzed. The curves of maximum generalized speed and maximum generalized force of the prototype are computed out and plotted. Finally, the com- puting and analyzing results of the operating characteristics are confirmed through the experiment.     

Influences affecting the soil-water characteristic curve

INTRODUCTION The soil-water characteristic curve (SWCC) gives the relationship between the amount of water in the soil (i.e. gravimetric or volumetric water content) and soil suction (i.e. matric suction at low suction and total suction at high suction). Many properties of a partially saturated soil such as the coefficient of permeability, shear strength and volume strain, pore size distribution, the amount of water contained in the pores at any suction, can be obtained from the SWCC. …     

Student Perceptions of Chemistry Laboratory Learning Environments, Student–Teacher Interactions and Attitudes in Secondary School Gifted Education Classes in Singapore

This study investigated the chemistry laboratory classroom environment, teacher–student interactions and student attitudes towards chemistry among 497 gifted and non-gifted secondary-school students in Singapore. The data were collected using the 35-item Chemistry Laboratory Environment Inventory (CLEI), the 48-item Questionnaire on Teacher Interaction (QTI) and the 30-item Questionnaire on Chemistry-Related Attitudes (QOCRA). Results supported the validity and reliability of the CLEI and QTI for this sample. Stream (gifted versus non-gifted) and gender differences were found in actual and preferred chemistry laboratory classroom environments and teacher–student interactions. Some statistically significant associations of modest magnitude were found between students' attitudes towards chemistry and both the laboratory classroom environment and the interpersonal behaviour of chemistry teachers. Suggestions for improving chemistry laboratory classroom environments and the teacher–student interactions for gifted students are provided.     

Extraordinary Animals and Expository Writing: Zoo in the Classroom

A zoo outreach program led to placing animals in classrooms where those animals became foci for numerous learning activities such as writing, observing, and care. Systematic debriefings suggested uniqueness to learning outcomes connected to zoo animals. Subsequent analysis of student writing indicated that students responded to situational interest by recording more observations, made use of more science facts, and used more science vocabulary when writing about unique animals (albino hedgehog, legless lizard) than ‘ordinary’ animals (rabbit, dove). The results are interpreted in terms of motivation, creating situational interest, and the familiarity of the schema available to the students. Policy implications are discussed.     

Initial and Further Education: Substitutes or Complements? Differences in Continuing Education and Training over the Life-Course of European Workers

This investigation examines the place of initial and further education in continuing education and training over the life-course of workers across Europe. The evidence presented demonstrates that in countries with a strong orientation towards vocational education, participation in continuing education and training among employees is higher than in countries that mainly provide general education. Moreover, it can be seen that the effect of the vocational orientation of the education system increases over the life-course of workers. The conclusion of this investigation is that further education complements rather than substitutes for initial education. This implies that national education and training policies meant to encourage lifelong learning should not only attempt to expand or redirect training received by already experienced workers, but also try to facilitate participation in initial vocational training.     

Promoting technology integration through collaborative apprenticeship

Teachers often learn technology skills and integration strategies in intensive seminars, ineffective means for professional learning because experiences are seldom transferred to instructional practices. Thus, effective technology integration requires teachers to obtain learning experiences within the context of their teaching so they can practice, reflect, and modify their practices. Learning in a teaching community is a social process that involves ongoing, on-site, and just-in-time support. Teachers need avenues to continually interact to provide such support across all members of the community. Collaborative Apprenticeship, a professional development model featuring reciprocal interactions, is one such approach to promoting technology integration. Teachers experienced in technology use serve as mentors of peer-teachers' technology applications aimed at improving instruction. Technology is progressively infused as peer-teachers learn to design technology-rich lessons from their technology-savvy peers through modeling, collaboration, and coaching.     

What Can Clients Tell Us about Seeking Counselling and Their Experience of It?

Research on counselling is often unknown to or ignored by counsellors. Research that explores counselling from the client’s perspective is even less familiar to most counsellors, perhaps because there is far less of it compared to the quantity of research investigating the process from the counsellor’s point of view. Nevertheless, research presenting the client’s perspective can be a useful guide to both counsellors and their clients. With this aim in mind, this article summarises some of the research that has been conducted from the client’s point of view and suggests implications for counselling practice.     

Promoting Parents' Social Capital to Increase Children's Attendance in Head Start: Evidence From an Experimental Intervention

Improving children's attendance is a high priority for Head Start and other early childhood education programs serving low-income children. We conducted a randomized control trial in a major northern city to evaluate the impact of a low-cost intervention designed to promote parents' social capital as a potential influence on children's attendance in Head Start centers. The intervention assigned children to treatment group classrooms based on (a) neighborhood of residence (geography condition) or (b) the geography condition plus the opportunity for parents to form partnerships in support of their children's attendance, or to control group classrooms according to Head Start guidelines only. We did not find impacts on average attendance throughout the year. However, the intervention did lead to increased attendance during the winter when average center attendance was lowest. There were no impacts on fall or spring attendance. Follow-up exploratory analyses of focus groups with parents and staff suggested that parents' level of connection and trust, self-generated partnership strategies, and commitment to their children's education may be factors by which parents' social capital expands and children's attendance improves.