Barrier Lowering and Field Penetration at Metal-Dielectric Interfaces

We report here photoemission measurements on Si-SiO_2-Al structures in which the metal-SiO_2 barrier energy has been determined as a function of the electric field strength E in the dielectric. The expected barrier lowering is the sum of two terms: a) the Schottky term, proportional to E^(1/2) and b) a term due to the penetration of the electric field into the metal electrode, proportional to E. The experimental results are in good agreement with the model, where the Schottky effect involves the optical value of the dielectric constant of the oxide and the Thomas-Fermi screening distance in the metal is 1 Å. To our knowledge this represents the first unambiguous quantitative determination of either effect in a polar dielectric, although the Schottky effect alone has been observed in silicon

Stability of Solid State Reaction Fronts

We analyze the stability of a planar solid-solid interface at which a chemical reaction occurs. Examples include oxidation, nitridation, or silicide formation. Using a continuum model, including a general formula for the stress-dependence of the reaction rate, we show that stress effects can render a planar interface dynamically unstable with respect to perturbations of intermediate wavelength

Using an Escape Room toolbox approach to enhance pharmacology education

Background: Faculty are encouraged to use a variety of teaching/learning strategies to engage nursing students. While simulation and games are now common, there were no reports in the nursing literature using an “escape room” concept. Escape rooms use an entertainment approach as teams engage in critical thinking to solve puzzles and find clues to escape a room. In the classroom setting, this concept is modified to solve a mystery by finding various objects through a series of puzzles to locate clues. Some of these games involve finding numerical clues to open locks on a box, such as a toolbox. The purpose of this study was to describe the use of a toolbox gaming strategy based on an escape room concept to help students learn about cardiovascular medications in a pharmacology course. Methods: This pilot study employed a descriptive qualitative method to investigate an approach to pharmacology education. The sample consisted of first semester nursing students. Results: Student responses to criteria-based questions resulted in three themes: engaging, teamwork, and frustration, related to using a toolbox scenario strategy as a pathway to learning. Conclusions: This descriptive study yielded mixed results from the students who were frustrated by time constraints but engaged in the learning experience. Lessons are offered for future improvements

Isoscalar dipole strength in ^{208}_{82}Pb_{126}: the spurious mode and the strength in the continuum

Isoscalar dipole (compression) mode is studied first using schematic harmonic-oscillator model and, then, the self-consistent Hartree-Fock (HF) and random phase approximation (RPA) solved in coordinate space. Taking ^{208}Pb and the SkM* interaction as a numerical example, the spurious component and the strength in the continuum are carefully examined using the sum rules. It is pointed out that in the continuum calculation one has to use an extremely fine radial mesh in HF and RPA in order to separate, with good accuracy, the spurious component from intrinsic excitations.Comment: 19 pages, 2 figure

February 1966

Massachusetts Turf and Lawn Grass CouncilBetter Turf Through Research and Educatio

A qualitative study of independent fast food vendors near secondary schools in disadvantaged Scottish neighbourhoods

Background: Preventing and reducing childhood and adolescent obesity is a growing priority in many countries. Recent UK data suggest that children in more deprived areas have higher rates of obesity and poorer diet quality than those in less deprived areas. As adolescents spend a large proportion of time in school, interventions to improve the food environment in and around schools are being considered. Nutrient standards for school meals are mandatory in the UK, but many secondary pupils purchase foods outside schools at break or lunchtime that may not meet these standards. Methods: Qualitative interviews were conducted with fast food shop managers to explore barriers to offering healthier menu options. Recruitment targeted independently-owned shops near secondary schools (pupils aged c.12-17) in low-income areas of three Scottish cities. Ten interviews were completed, recorded, and transcribed for analysis. An inductive qualitative approach was used to analyse the data in NVivo 10. Results: Five themes emerged from the data: pride in what is sold; individual autonomy and responsibility; customer demand; profit margin; and neighbourhood context. Interviewees consistently expressed pride in the foods they sold, most of which were homemade. They felt that healthy eating and general wellbeing are the responsibility of the individual and that offering what customers want to eat, not necessarily what they should eat, was the only way to stay in business. Most vendors felt they were struggling to maintain a profit, and that many aspects of the low-income neighbourhood context would make change difficult or impossible. Conclusions: Independent food shops in low-income areas face barriers to offering healthy food choices, and interventions and policies that target the food environment around schools should take the neighbourhood context into consideration

Healthcare satisfaction in older and younger patients with cancer

Objective Although older patients represent the most rapidly growing segment of the oncology population, clinical care is guided by very little data on patient-reported outcomes, particularly satisfaction with healthcare. Using a large cancer center registry, we sought to describe factors associated with satisfaction with care for older and younger oncology patients. Methods Data were collected through the University of North Carolina Health Registry Cancer Survivorship Cohort. Satisfaction was measured with the Patient Satisfaction Questionnaire Short Form. Quality of life (QOL) measures included were the Promis Global short form and the Functional Assessment of Cancer Therapy General (FACT-G). Results A total of 2385 patients were included. 460 (20%) were aged 70 and above (older group). Older patients reported significantly higher levels of satisfaction in domains of time spent with doctor (scores 3.84 versus 3.73 p = 0.03) and financial aspects (scores 4.03 versus 3.44 p < 0.001) compared to younger patients. In multivariable analysis, higher QOL scores and higher self-reported ECOG performance status were associated with higher satisfaction scores. African American race was associated with lower satisfaction scores in all age groups. QOL was more closely correlated with satisfaction in older patients compared to younger patients. Conclusions Older patients with cancer report higher levels of satisfaction with care, in part due to lesser financial burden of care. Better QOL is associated with satisfaction with care in older patients. Use of patient-reported outcomes such as patient satisfaction may help improve patient-centered geriatric oncology care