Synthesis of Ca(OH)2 nanoparticles with the addition of Triton X-100. Protective treatments on natural stones: Preliminary results

Calcium hydroxide is typically used in Cultural Heritage conservation for superficial protective treatments thanks to its conversion into calcium carbonate. Calcium carbonate is, in fact, compatible with many carbonate-based architectonic surfaces, because its characteristics are similar to those of the restored materials. In order to improve calcium hydroxide treatments, Ca(OH)₂ particles with sub-micrometric dimensions (nanolimes), are synthesised by a chemical precipitation process: a sodium hydroxide solution, used as precipitator, is added, drop by drop, to a calcium chloride one. In this paper, a nanometric calcium hydroxide, to be used in stones treatment, is produced adding in the initial solutions a surfactant agent (Triton X-100); the solutions are then mixed together simultaneously, drastically reducing the time needful for preparation. Different contents of surfactant are employed, and the influence on particles dimension and carbonatation process is analysed too. The obtained Ca(OH)₂ nanoparticles are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron diffraction (ED). The Ca(OH)₂ nanoparticles are regularly shaped, hexagonally plated and with side dimensions less than 200 nm: in particular, increasing the surfactant content, the particle dimension reaches values until 20 nm. Comparing nanolime suspensions obtained without and with the addition of the surfactant agent, the last ones have comparable, if not better, performances in terms of average particle size and morphology, crystallinity and reactivity. Afterwards, the alcoholic nanolime suspension obtained by using Triton X-100 is applied on some natural stones; in fact, the aim of this section is to compare the obtained results with those achieved using a nanolime synthesised without the surfactant agent. To evaluate the treatment effectiveness in a preliminary way, standard tests are performed and compared with the same tests previously obtained by the nanolime synthesised without the surfactant agent: “Scotch Tape Test” and capillarity test.     

Children with disabilities in the child protective services system: An analog study of investigation and case management

ObjectiveThe study used a series of vignettes to investigate how the presence of three disabilities (cerebral palsy, intellectual disabilities, emotional/behavioral disabilities) affects the processes and outcomes of child abuse investigations at two levels of child injury severity (moderate, severe).MethodSeventy-five CPS case workers completed study surveys and answered questions in response to a series of eight vignettes.ResultsThis study revealed differences in the responses of CPS case workers when the alleged victim of physical abuse had a disability. Children with disabilities were more likely than children without disabilities to be seen as having characteristics that contributed to their abuse. Most CPS workers felt at least some empathy with abusive parents; empathy was highest when the children had emotional/behavioral disabilities. Services recommended for families of children with disabilities were more likely to be child-focused. Parent-focused services, such as individual counseling and adult anger management, were more likely to be recommended for families of children without disabilities. In general, differences among disability groups and between cases involving children with and without disabilities were more pronounced when the children's injuries were less severe. Even with more severe injuries, such as a concussion or broken bones, the CPS workers still responded differently depending on the disability status of the child victims.ConclusionsRecommendations are made concerning the utilization of investigation teams that include disability specialists and the need for further disability-related training for CPS case workers.Practice implicationsThere is a strong need for training related to disability, with an emphasis on attitudes as well as knowledge and skills. The training should include examples of healthy family functioning and positive aspects of parenting a child with a disability to counteract the prevailing perception of disability as a cause of chronic stress and dysfunction; identification of broader ecological contexts in which these families live, including social response to disability and the disability-related service system and; strategies for disentangling the signs of abuse from characteristics of the disability. Interdisciplinary teams should include members from disability-related fields to share expertise and increase communication between systems.     

University students’ conceptions of learning across multiple domains

Research on students’ conceptions of learning is a growing and complex area of interest in the field of psychology of education. Even though much of the investigation addressed to explore conceptions of learning at the university level, still less research has considered how naïve (i.e. ‘learning as reduction of deficit knowledge through individual effort’) and sophisticated (i.e. ‘learning as opportunity and self-efficacy’) conceptions of learning are related to personal and contextual factors. This research investigated how gender, academic area, and level of study influence university students’ conceptions of learning. Three hundred forty-six university students participated in the study. They were either from humanities (240) or technical-scientific (106) areas of study and they were attending either a Bachelor (140) or Master’s degree (206) course. Conceptions of learning were explored using a self-report instrument (Learning Conceptions Questionnaire; LCQ). A MANOVA revealed that females show conceptions of learning more related to social and motivational aspects of learning with a greater personal involvement, compared with males. No typical pattern of conceptions of learning was found for humanities students or for technical-scientific students. Increasing with the level of study, students showed both naïve and sophisticated conceptions of learning increased, since both ‘learning as reduction of deficit knowledge through individual effort’ and ‘learning as opportunities and self-efficacy’ were more likely. Implications of these results and future lines of research will be discussed.     

e-Business usage across and within firms in the UK: profitability, externalities and policy

Using data from the third UK Community Innovation Survey we model the usage of e-business across and within firms in the UK in the year 2000 as a single observation upon an integrated process of inter- and intra-firm diffusion. The intra-firm dimension is a significant extension to standard analysis. The model estimates indicate that the pattern of e-business usage reflects the heterogeneity of firms in terms of size, other innovative activity and labour force skills (generating differences in the payoffs to use) as well as market and non-market intermediated externalities. The policy implications of the findings are discussed.