434 research outputs found
Next generation of consumer aerosol valve design using inert gases
The current global consumer aerosol products such as deodorants, hairsprays, air-fresheners, polish, insecticide, disinfectant
are primarily utilised unfriendly environmental propellant of liquefied petroleum gas (LPG) for over three decades.
The advantages of the new innovative technology described in this paper are: (i) no butane or other liquefied
hydrocarbon gas; (ii) compressed air, nitrogen or other safe gas propellant; (iii) customer acceptable spray quality and
consistency during can lifetime; (iv) conventional cans and filling technology. Volatile organic compounds and greenhouse
gases must be avoided but there are no flashing propellants replacements that would provide the good atomisation and
spray reach. On the basis of the energy source for atomising, the only feasible source is inert gas (i.e. compressed air),
which improves atomisation by gas bubbles and turbulence inside the atomiser insert of the actuator. This research
concentrates on using ‘bubbly flow’ in the valve stem, with injection of compressed gas into the passing flow, thus also
generating turbulence. Using a vapour phase tap in conventional aerosol valves allows the propellant gas into the liquid
flow upstream of the valve. However, forcing bubbly flow through a valve is not ideal. The novel valves designed here,
using compressed gas, thus achieved the following objectives when the correct combination of gas and liquid inlets to the
valve, and the type and size of atomiser ‘insert’ were derived:
1. Produced a consistent flow rate and drop size of spray throughout the life of the can, compatible with the current
conventional aerosols that use LPG: a new ‘constancy’ parameter is defined and used to this end.
2. Obtained a discharge flow rate suited to the product to be sprayed; typically between 0.4 g/s and 2.5 g/s.
3. Attained the spray droplets size suited to the product to be sprayed; typically between 40 mm and 120 mm
Local Thermometry of Neutral Modes on the Quantum Hall Edge
A system of electrons in two dimensions and strong magnetic fields can be
tuned to create a gapped 2D system with one dimensional channels along the
edge. Interactions among these edge modes can lead to independent transport of
charge and heat, even in opposite directions. Measuring the chirality and
transport properties of these charge and heat modes can reveal otherwise hidden
structure in the edge. Here, we heat the outer edge of such a quantum Hall
system using a quantum point contact. By placing quantum dots upstream and
downstream along the edge of the heater, we can measure both the chemical
potential and temperature of that edge to study charge and heat transport,
respectively. We find that charge is transported exclusively downstream, but
heat can be transported upstream when the edge has additional structure related
to fractional quantum Hall physics.Comment: 24 pages, 18 figure
Broken symmetry states and divergent resistance in suspended bilayer graphene
Graphene [1] and its bilayer have generated tremendous excitement in the
physics community due to their unique electronic properties [2]. The intrinsic
physics of these materials, however, is partially masked by disorder, which can
arise from various sources such as ripples [3] or charged impurities [4].
Recent improvements in quality have been achieved by suspending graphene flakes
[5,6], yielding samples with very high mobilities and little charge
inhomogeneity. Here we report the fabrication of suspended bilayer graphene
devices with very little disorder. We observe fully developed quantized Hall
states at magnetic fields of 0.2 T, as well as broken symmetry states at
intermediate filling factors , , and . The
devices exhibit extremely high resistance in the state that grows
with magnetic field and scales as magnetic field divided by temperature. This
resistance is predominantly affected by the perpendicular component of the
applied field, indicating that the broken symmetry states arise from many-body
interactions.Comment: 23 pages, including 4 figures and supplementary information; accepted
to Nature Physic
The Effects of Two Planning Interventions on the Oral Health Behavior of Iranian Adolescents: A Cluster Randomized Controlled Trial.
PURPOSE: The aim of this study was to investigate the effectiveness of a planning intervention (specifying when, where, and how to act) and an implementation intention intervention (specifying the same in the format of an if-then plan) in increasing self-reported brushing in adolescents.
METHODS: The study adopted a cluster randomized controlled trial design, and 1158 students in 48 schools were randomized to planning, implementation intention, or active control conditions. After baseline assessment, all participants received a leaflet containing information and recommendations on oral health and instructions on correct brushing behavior. After reading the leaflets, they were provided with a toothbrush and toothpaste plus a calendar in which to record their brushing. Participants in the planning condition and in the implementation intention condition also received instructions to form specific plans regarding brushing behavior. Self-reported brushing, perceived behavioral control, self-monitoring, intention, frequency of planning, oral health-related quality of life, and dental plaque and periodontal status were measured 1 and 6 months later.
RESULTS: Both intervention conditions showed a significant improvement in the frequency of self-reported brushing, self-monitoring, frequency of planning, intention, perceived behavioral control, plaque index, periodontal health, and oral health-related quality of life compared to the control condition at both follow-ups. Comparing the two intervention conditions revealed that adolescents who received the implementation intention intervention had significantly greater improvement in the frequency of self-reported brushing, intention, frequency of planning, and periodontal health than those in planning condition.
CONCLUSIONS: Taken together, the findings suggest that forming implementation intentions as well as planning has the potential to increase dental self-reported brushing rates in adolescents, but that forming implementation intentions has the strongest impact on dental hygiene behavior and is, therefore, recommended.
TRIAL REGISTRATION NUMBER: The trial was registered with the ClinicalTrials.gov database (NCT02066987) https://www.clinicaltrials.gov/ct2/show/NCT02066987
A double blind, randomised placebo controlled trial of topical 2% viscous lidocaine in improving oral intake in children with painful infectious mouth conditions
<p>Abstract</p> <p>Background</p> <p>Painful infectious mouth conditions are a common presentation to emergency departments. Although self limiting, painful ulcerative lesions and inflamed mucosa can decrease oral intake and can lead to dehydration. Oral analgesia is of limited efficacy and is often refused by the patient. Despite widespread use of oral 2% viscous lidocaine for many years, there is little evidence for its efficacy as an analgesic and in aiding oral intake in children with painful infectious mouth conditions. This study aims to establish the effectiveness of 2% viscous lidocaine in increasing oral intake in these children by comparing it with placebo.</p> <p>Methods/Design</p> <p>This study is a randomised double-blind placebo controlled trial of children between 6 months and 8 years of age with painful infectious mouth conditions defined as gingivostomatitis (herpetic or non herpetic), ulcerative pharyngitis, herpangina and hand foot and mouth disease as assessed by the treating clinician in association with a history of poor oral fluid intake. It will be conducted at a single tertiary paediatric emergency department in Melbourne Australia.</p> <p>20 patients have already been randomised to receive 2% lidocaine or placebo in a pilot study to determine the sample size in a preplanned adaptive design. A further 80 patients will be randomised to receive either 2% lidocaine or placebo. The placebo agent is identical to lidocaine in terms of appearance, flavour and smell. All clinical and research staff involved, patients and their parents will be blinded to treatment allocation.</p> <p>The primary endpoint is the amount of fluid ingested by each child, expressed in ml/kg, within 60 minutes from the time of administration of the study mixture. Secondary endpoints are the proportion of patients ingesting 5 ml/kg and 10 ml/kg at 30 and 60 minutes after drug administration and the incidence of adverse events. Longer term outcomes will include the proportion of patients requiring hospital admission and length of emergency department stay.</p> <p>Discussion</p> <p>This trial will define the role of 2% lidocaine in the treatment of painful infectious mouth conditions</p> <p>Trial registration</p> <p>The trial is registered with the Australian and New Zealand Clinical Trials Registry - <a href="http://www.anzctr.org.au/ACTRN12609000566235.aspx">ACTRN12609000566235</a>.</p
Factors Relating to Managerial Stereotypes: The Role of Gender of the Employee and the Manager and Management Gender Ratio
Several studies have shown that the traditional stereotype of a "good" manager being masculine and male still exists. The recent changes in the proportion of women and female managers in organizations could affect these two managerial stereotypes, leading to a stronger preference for feminine characteristics and female leaders. This study examines if the gender of an employee, the gender of the manager, and the management gender ratio in an organization are related to employees' managerial stereotypes. 3229 respondents working in various organizations completed an electronic questionnaire. The results confirm our hypotheses that, although the general stereotype of a manager is masculine and although most prefer a man as a manager, female employees, employees with a female manager, and employees working in an organization with a high percentage of female managers, have a stronger preference for feminine characteristics of managers and for female managers. Moreover, we find that proximal variables are much stronger predictors of these preferences than more distal variables. Our study suggests that managerial stereotypes could change as a result of personal experiences and changes in the organizational context. The results imply that increasing the proportion of female managers is an effective way to overcome managerial stereotyping. This study examines the influence on managerial stereotypes of various proximal and distal factors derived from theory among a large group of employees (in contrast to students)
Dimension reduction for systems with slow relaxation
We develop reduced, stochastic models for high dimensional, dissipative
dynamical systems that relax very slowly to equilibrium and can encode long
term memory. We present a variety of empirical and first principles approaches
for model reduction, and build a mathematical framework for analyzing the
reduced models. We introduce the notions of universal and asymptotic filters to
characterize `optimal' model reductions for sloppy linear models. We illustrate
our methods by applying them to the practically important problem of modeling
evaporation in oil spills.Comment: 48 Pages, 13 figures. Paper dedicated to the memory of Leo Kadanof
Evaluation of the current knowledge limitations in breast cancer research: a gap analysis
BACKGROUND
A gap analysis was conducted to determine which areas of breast cancer research, if targeted by researchers and funding bodies, could produce the greatest impact on patients.
METHODS
Fifty-six Breast Cancer Campaign grant holders and prominent UK breast cancer researchers participated in a gap analysis of current breast cancer research. Before, during and following the meeting, groups in seven key research areas participated in cycles of presentation, literature review and discussion. Summary papers were prepared by each group and collated into this position paper highlighting the research gaps, with recommendations for action.
RESULTS
Gaps were identified in all seven themes. General barriers to progress were lack of financial and practical resources, and poor collaboration between disciplines. Critical gaps in each theme included: (1) genetics (knowledge of genetic changes, their effects and interactions); (2) initiation of breast cancer (how developmental signalling pathways cause ductal elongation and branching at the cellular level and influence stem cell dynamics, and how their disruption initiates tumour formation); (3) progression of breast cancer (deciphering the intracellular and extracellular regulators of early progression, tumour growth, angiogenesis and metastasis); (4) therapies and targets (understanding who develops advanced disease); (5) disease markers (incorporating intelligent trial design into all studies to ensure new treatments are tested in patient groups stratified using biomarkers); (6) prevention (strategies to prevent oestrogen-receptor negative tumours and the long-term effects of chemoprevention for oestrogen-receptor positive tumours); (7) psychosocial aspects of cancer (the use of appropriate psychosocial interventions, and the personal impact of all stages of the disease among patients from a range of ethnic and demographic backgrounds).
CONCLUSION
Through recommendations to address these gaps with future research, the long-term benefits to patients will include: better estimation of risk in families with breast cancer and strategies to reduce risk; better prediction of drug response and patient prognosis; improved tailoring of treatments to patient subgroups and development of new therapeutic approaches; earlier initiation of treatment; more effective use of resources for screening populations; and an enhanced experience for people with or at risk of breast cancer and their families. The challenge to funding bodies and researchers in all disciplines is to focus on these gaps and to drive advances in knowledge into improvements in patient care
Vitamin D supplementation and breast cancer prevention : a systematic review and meta-analysis of randomized clinical trials
In recent years, the scientific evidence linking vitamin D status or supplementation to breast cancer has grown notably. To investigate the role of vitamin D supplementation on breast cancer incidence, we conducted a systematic review and meta-analysis of randomized controlled trials comparing vitamin D with placebo or no treatment. We used OVID to search MEDLINE (R), EMBASE and CENTRAL until April 2012. We screened the reference lists of included studies and used the “Related Article” feature in PubMed to identify additional articles. No language restrictions were applied. Two reviewers independently extracted data on methodological quality, participants, intervention, comparison and outcomes. Risk Ratios and 95% Confident Intervals for breast cancer were pooled using a random-effects model. Heterogeneity was assessed using the I2 test. In sensitivity analysis, we assessed the impact of vitamin D dosage and mode of administration on treatment effects. Only two randomized controlled trials fulfilled the pre-set inclusion criteria. The pooled analysis included 5372 postmenopausal women. Overall, Risk Ratios and 95% Confident Intervals were 1.11 and 0.74–1.68. We found no evidence of heterogeneity. Neither vitamin D dosage nor mode of administration significantly affected breast cancer risk. However, treatment efficacy was somewhat greater when vitamin D was administered at the highest dosage and in combination with calcium (Risk Ratio 0.58, 95% Confident Interval 0.23–1.47 and Risk Ratio 0.93, 95% Confident Interval 0.54–1.60, respectively). In conclusions, vitamin D use seems not to be associated with a reduced risk of breast cancer development in postmenopausal women. However, the available evidence is still limited and inadequate to draw firm conclusions. Study protocol code: FARM8L2B5L
Laser cooling of a nanomechanical oscillator into its quantum ground state
A patterned Si nanobeam is formed which supports co-localized acoustic and
optical resonances that are coupled via radiation pressure. Starting from a
bath temperature of T=20K, the 3.68GHz nanomechanical mode is cooled into its
quantum mechanical ground state utilizing optical radiation pressure. The
mechanical mode displacement fluctuations, imprinted on the transmitted cooling
laser beam, indicate that a final phonon mode occupancy of 0.85 +-0.04 is
obtained.Comment: 18 pages, 10 figure
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