234 research outputs found
Synthesis of Multiwall Carbon Nanotubes by Inductive Heating CCVD
The CCVD syntheses of MWCNTs from acetylene on Fe:Co:CaCO 3 and Fe:Co:CaO were performed using two different methods of heating: outer furnace and inductive heating. The comparative analysis of the MWCNTs obtained by the two methods show that the tubes grown in inductive heating have smaller diameters (5-25 nm), with fewer walls and aspect ratio of the order of hundreds. The ratio of outer to inner diameter (od/id) is ranging between 2 and 2.5. Inductively assisted CCVD is a very attractive method because of the major advantages that it presents, like low energetic consumption, thinner, well crystallized and more uniform tubes
Degradation of Organics in a Glow Discharge Under Martian Conditions
The primary objective of this project is to understand the consequences of glow electrical discharges on the chemistry and biology of Mars. The possibility was raised some time ago that the absence of organic material and carbonaceous matter in the Martian soil samples studied by the VikinG Landers might be due in part to an intrinsic atmospheric mechanism such as glow discharge. The high probability for dust interactions during Martian dust storms and dust devils, combined with the cold, dry climate of Mars most likely results in airborne dust that is highly charged. Such high electrostatic potentials generated during dust storms on Earth are not permitted in the low-pressure CO2 environment on Mars; therefore electrostatic energy released in the form of glow discharges is a highly likely phenomenon. Since glow discharge methods are used for cleaning and sterilizing surfaces throughout industry, the idea that dust in the Martian atmosphere undergoes a cleaning action many times over geologic time scales appears to be a plausible one
Assessing students' experiences of teaching-learning environments and approaches to learning.:Validation of a questionnaire used in different countries and varying contexts.
Twenty-First Century Research Needs in Electrostatic Processes Applied to Industry and Medicine
From the early century Nobel Prize winning (1923) experiments with charged oil droplets, resulting in the discovery of the elementary electronic charge by Robert Millikan, to the early 21st century Nobel Prize (2002) awarded to John Fenn for his invention of electrospray ionization mass spectroscopy and its applications to proteomics, electrostatic processes have been successfully applied to many areas of industry and medicine. Generation, transport, deposition, separation, analysis, and control of charged particles involved in the four states of matter: solid, liquid, gas, and plasma are of interest in many industrial and biomedical processes. In this paper, we briefly discuss some of the applications and research needs involving charged particles in industrial and medical applications including: (1) Generation and deposition of unipolarly charged dry powder without the presence of ions or excessive ozone, (2) Control of tribocharging process for consistent and reliable charging, (3) Thin film (less than 25 micrometers) powder coating and Powder coating on insulative surfaces, (4) Fluidization and dispersion of fine powders, (5) Mitigation of Mars dust, (6) Effect of particle charge on the lung deposition of inhaled medical aerosols, (7) Nanoparticle deposition, and (8) Plasma/Corona discharge processes. A brief discussion on the measurements of charged particles and suggestions for research needs are also included
Integrated liaison psychiatry services in England: a qualitative study of the views of liaison practitioners and acute hospital staffs from four distinctly different kinds of liaison service
Background: Liaison psychiatry services provide mental health care for patients in physical healthcare (usually acute hospital) settings including emergency departments. Liaison work involves close collaboration with acute hospital staff so that high quality care can be provided. Services however are patchy, relatively underfunded, heterogeneous and poorly integrated into acute hospital care pathways. Methods: We carried out in-depth semi-structured interviews with 73 liaison psychiatry and acute hospital staff from 11 different acute hospitals in England. The 11 hospitals were purposively sample to represent hospitals in which four different types of liaison services operated. Staff were identified to ensure diversity according to professional background, sub-specialism within the team, and whether they had a clinical or managerial focus. All interviews were audio-recorded and transcribed. The data were analysed using a best-fit framework analysis. Results: Several key themes emerged in relation to facilitators and barriers to the effective delivery of integrated services. There were problems with continuity of care across the secondary-primary interface; a lack of mental health resources in primary care to support discharge; a lack of shared information systems; a disproportionate length of time spent recording information as opposed to face to face patient contact; and a lack of a shared vision of care. Relatively few facilitators were identified although interviewees reported a focus on patient care. Similar problems were identified across different liaison service types. Conclusions: The problems that we have identified need to be addressed by both liaison and acute hospital teams, managers and funders, if high quality integrated physical and mental health care is to be provided in the acute hospital setting
The effects of constructivist learning environments: A commentary
This special issue on the effects of constructivist learning environments is based on a symposium organized during the last annual meeting of the American Educational Research Association in Chicago. The studies in this issue not only provide an overview of the multitude of forms a constructivist learning environment can take, they also provide the reader with an overview of recent advances in this domain of research. The present discussion article provides a critical reflection on the studies in this special issue and tries to identify their prospects and limitations
Organisation and delivery of liaison psychiatry services in general hospitals in England: results of a national survey
Objectives: To describe the current provision of hospital-based liaison psychiatry services in England, and to determine different models of liaison service that are currently operating in England.
Design: Cross-sectional observational study comprising an electronic survey followed by targeted telephone interviews.
Setting: All 179 acute hospitals with an emergency department in England.
Participants: 168 hospitals that had a liaison psychiatry service completed an electronic survey. Telephone interviews were conducted for 57 hospitals that reported specialist liaison services additional to provision for acute care.
Measures: Data included the location, service structures and staffing, working practices, relations with other mental health service providers, policies such as response times and funding. Model 2-based clustering was used to characterise the services. Telephone interviews identified the range of additional liaison psychiatry services provided.
Results: Most hospitals (141, 79%) reported a 7-day service responding to acute referrals from the emergency department and wards. However, under half of hospitals had 24 hours access to the service (78, 44%). One-third of hospitals (57, 32%) provided non-acute liaison work including outpatient clinics and links to specialist hospital services. 156 hospitals (87%) had a multidisciplinary service including a psychiatrist and mental health nurses. We derived a four-cluster model of liaison psychiatry using variables resulting from the electronic survey; the salient features of clusters were staffing numbers, especially nursing; provision of rapid response 24 hours 7-day acute services; offering outpatient and other non-acute work, and containing age-specific teams for older adults.
Conclusions: This is the most comprehensive study to date of liaison psychiatry in England and demonstrates the wide availability of such services nationally. Although all services provide an acute assessment function, there is no uniformity about hours of coverage or expectation of response times. Most services were better characterised by the model we developed than by current classification systems for liaison psychiatry
Influence of family and friend smoking on intentions to smoke and smoking-related attitudes and refusal self-efficacy among 9-10 year old children from deprived neighbourhoods: a cross-sectional study.
BACKGROUND: Smoking often starts in early adolescence and addiction can occur rapidly. For effective smoking prevention there is a need to identify at risk groups of preadolescent children and whether gender-specific intervention components are necessary. This study aimed to examine associations between mother, father, sibling and friend smoking and cognitive vulnerability to smoking among preadolescent children living in deprived neighbourhoods. METHODS: Cross-sectional data was collected from 9-10 year old children (n =1143; 50.7% girls; 85.6% White British) from 43 primary schools in Merseyside, England. Children completed a questionnaire that assessed their smoking-related behaviour, intentions, attitudes, and refusal self-efficacy, as well as parent, sibling and friend smoking. Data for boys and girls were analysed separately using multilevel linear and logistic regression models, adjusting for individual cognitions and school and deprivation level. RESULTS: Compared to girls, boys had lower non-smoking intentions (P = 0.02), refusal self-efficacy (P = 0.04) and were less likely to agree that smoking is 'definitely' bad for health (P < 0.01). Friend smoking was negatively associated with non-smoking intentions in girls (P < 0.01) and boys (P < 0.01), and with refusal self-efficacy in girls (P < 0.01). Sibling smoking was negatively associated with non-smoking intentions in girls (P < 0.01) but a positive association was found in boys (P = 0.02). Boys who had a smoking friend were less likely to 'definitely' believe that the smoke from other people's cigarettes is harmful (OR 0.57, 95% CI: 0.35 to 0.91, P = 0.02). Further, boys with a smoking friend (OR 0.38, 95% CI: 0.21 to 0.69, P < 0.01) or a smoking sibling (OR 0.45, 95% CI: 0.21 to 0.98) were less likely to 'definitely' believe that smoking is bad for health. CONCLUSION: This study indicates that sibling and friend smoking may represent important influences on 9-10 year old children's cognitive vulnerability toward smoking. Whilst some differential findings by gender were observed, these may not be sufficient to warrant separate prevention interventions. However, further research is needed
An instrument to determine the technological literacy levels of upper secondary school students
In this article, an instrument for assessing upper secondary school students’
levels of technological literacy is presented. The items making up the instrument emerged
from a previous study that employed a phenomenographic research approach to explore
students’ conceptions of technology in terms of their understanding of the nature of
technology and their interaction with technological artefacts. The instrument was validated
through administration to 1,245 students on completion of their 12 years of formal
schooling. A factor analysis was conducted on the data and Cronbach alpha reliability coefficients
determined. The results show that a five-dimension factor structure (namely,
artefact, process, direction/instruction, tinkering, and engagement) strongly supported the
dimensions as developed during the original phenomenographic study. The Cronbach
alpha reliability co-efficient of each dimension was satisfactory. Based on these findings,
the instrument has been shown to be valid and reliable and can be used with confidence
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