Traditional roof coverings in the North York Moors National Park

Purpose – The paper seeks to deal with vernacular roofing practices within the North York Moors National Park. Design/methodology/approach – Initially the paper carries out a literature review of the geography and geology of the area and identifies what makes it physically unique. The paper then examines the development of various roofing materials, including thatch, stone slates and pantiles with case studies of old practice and modern methods from around the Park. Findings – Roofing styles are simplistic and have steered away from the intricate in favour of the indigenous or readily available. The paper demonstrates the much-regionalised nature of the roofing materials and recognises this as one of the special cultural features worthy of conservation. Research limitations/implications – The results are limited to the North York Moors National Park but the approach taken could be extended to other conservation areas. Practical implications – The results of the research will benefit those involved in the conservation of vernacular buildings in the North York Moors National Park. Originality/value – The paper calls for additional guidance for roofers and specifiers on traditional vernacular techniques and for existing funding under the Environmental Stewardship Scheme to be extended to include rural communities in National Parks

Beneficial effects of dark chocolate for episodic memory in healthy young adults: a parallel-groups acute intervention with a white chocolate control

There is good evidence that cocoa flavonoids can acutely improve cognitive function in humans, possibly via mechanisms such as increased cerebral blood flow. To date, much of the evidence is based on measures of executive function with extracts and cocoa-based interventions with a high flavonoid content. The aim of the present study was to explore whether benefits to episodic verbal memory and mood are observed two hours post consumption of a commercially available dark chocolate (DC) bar relative to a 35 g white chocolate bar (WC). Ninety-eight healthy young adults (n = 57 females) aged 18−24 years consumed either a 35 g DC bar or a calorie-matched low flavonoid WC bar. Verbal episodic memory and mood were assessed pre consumption and 2 h post consumption. An ANOVA analysis showed that the DC was associated with better verbal memory performance for several outcome measures of the Rey Auditory Verbal Learning Test relative to the WC, however, there were no effects on mood. These findings lend support to the notion that everyday available portions of dark chocolate can confer benefits to the brain in healthy consumers

The bryoflora of Fernando de Noronha, Brasil

Twenty-two species of bryophytes are reported from Fernando de Noronha. One of these, Fissidens veracruzensis Pursell, has not been reported previously from Brasil

The Development of Student Conceptions of the Earth-Sun Relationship in an Inquiry-Based Curriculum

This investigation examined conceptual change in three fifth-grade students as they participated in a curriculum on Earth's surface temperature. Data were collected via individual interviews and classroom observations and interactions, and were analyzed by comparing the students' thinking at various points before, during and after the unit. Throughout the study, the students exhibited misconceptions identified in current literature as well as novel misconceptions of their own. Although the curriculum was found to be partially effective, the students retained some misconceptions with which they began the study, revealing that conceptual understanding may be more fragmentary than theory-like, and that the depth of one's prior knowledge affects how readily new knowledge is constructed. Educational levels: Graduate or professional

Quantum Dynamics of Skyrmions in Chiral Magnets

We study the quantum propagation of a Skyrmion in chiral magnetic insulators by generalizing the micromagnetic equations of motion to a finite-temperature path integral formalism, using field theoretic tools. Promoting the center of the Skyrmion to a dynamic quantity, the fluctuations around the Skyrmionic configuration give rise to a time-dependent damping of the Skyrmion motion. From the frequency dependence of the damping kernel, we are able to identify the Skyrmion mass, thus providing a microscopic description of the kinematic properties of Skyrmions. When defects are present or a magnetic trap is applied, the Skyrmion mass acquires a finite value proportional to the effective spin, even at vanishingly small temperature. We demonstrate that a Skyrmion in a confined geometry provided by a magnetic trap behaves as a massive particle owing to its quasi-one-dimensional confinement. An additional quantum mass term is predicted, independent of the effective spin, with an explicit temperature dependence which remains finite even at zero temperature.Comment: 14 pages, 10 figure

Minimum Energy Path to Membrane Pore Formation and Rupture

We combine dynamic self-consistent field theory with the string method to calculate the minimum energy path to membrane pore formation and rupture. In the regime where nucleation can occur on experimentally relevant time scales, the structure of the critical nucleus is between a solvophilic stalk and a locally thinned membrane. Classical nucleation theory fails to capture these molecular details and significantly overestimates the free energy barrier. Our results suggest that thermally nucleated rupture may be an important factor for the low rupture strains observed in lipid membranes

Influence of Yttrium on the Thermal Stability of Ti-Al-N Thin Films

Ti(1-x)Al(x)N coated tools are commonly used in high-speed machining, where the cutting edge of an end-mill or insert is exposed to temperatures up to 1100 degrees C. Here, we investigate the effect of Yttrium addition on the thermal stability of Ti(1-x)Al(x)N coatings. Reactive DC magnetron sputtering of powder metallurgically prepared Ti(0.50)Al(0.50), Ti(0.49)Al(0.49)Y(0.02), and Ti(0.46)Al(0.46)Y(0.08) targets result in the formation of single-phase cubic (c) Ti(0.45)Al(0.55)N, binary cubic/wurtzite c/w-Ti(0.41)Al(0.57)Y(0.02)N and singe-phase w-Ti(0.38)Al(0.54)Y(0.08)N coatings. Using pulsed DC reactive magnetron sputtering for the Ti(0.49)Al(0.49)Y(0.02) target allows preparing single-phase c-Ti(0.46)Al(0.52)Y(0.02)N coatings. By employing thermal analyses in combination with X-ray diffraction and transmission electron microscopy investigations of as deposited and annealed (in He atmosphere) samples, we revealed that Y effectively retards the decomposition of the Ti(1-x-y)Al(x)Y(y)N solid-solution to higher temperatures and promotes the precipitation of c-TiN, c-YN, and w-AlN. Due to their different microstructure and morphology already in the as deposited state, the hardness of the coatings decreases from similar to 35 to 22 GPa with increasing Y-content and increasing wurtzite phase fraction. Highest peak hardness of similar to 38 GPa is obtained for the Y-free c-Ti(0.45)Al(0.55)N coating after annealing at T(a) = 950 degrees C, due to spinodal decomposition. After annealing above 1000 degrees C the highest hardness is obtained for the 2 mol % YN containing c-Ti(0.46)Al(0.52)Y(0.02)N coating with similar to 29 and 28 GPa for T(a) = 1150 and 1200 degrees C, respectively