Bending bad—testing caramel wafer bars (#TestATunnocks)

During the coronavirus pandemic, there have been significant challenges in the remote teaching and demonstration of experiments, especially those that require laboratory testing equipment. With a desire to give students a feel for our materials laboratory on open days and allow them to gain a deeper understanding of what materials science and engineering is about, we have designed an experiment focused on composite materials that can be performed remotely and without specialist equipment. This enabled students to experience a bend test sensorily through seeing, hearing and feeling it, creating a strong link to then being able to relate it to the pre-prepared experimental data taken in the laboratory. This fun, easy-to-run and engaging experiment allowed a shared experience and encouraged a discussion about students' observations, differences in results and implications of the bend strength of sandwich composites. We have found it not only works well universally by all ages but can be used with younger children to think about words such as 'stronger', 'stiffer' and 'flexible' and how materials can be different in different directions

Resonant x-ray, absorption of strong-field-ionized, CF Br

We report on an experimental and theoretical study of strong-field laser ionization of CF3Br followed by resonant x-ray absorption at the Br K-edge. Distinct 1s → 4p, 5p Rydberg transitions of Br q+ (q = 1-4) atomic ions are observed and identified with Hartree-Fock-Slater and relativistic configuration interaction calculations. Time-dependent density functional theory and ab initio molecular dynamics calculations were performed to simulate the dissociative ionization process and the molecular orbitals for the q = 1-4 charge states. Measurements were made with both parallel and perpendicular linear polarizations of the laser and x-rays, but dichroism was not observed, indicating negligible alignment by the laser ionization process. This result is explained by calculations on atomic Br and the molecular simulation

Hábito de crescimento de Colletotrichum gossypii e C. gossypii var. Cephalosporioides em sementes de algodoeiro Growth habit of Colletotrichum gossypii and C. Gossypii var. Cephalosporioides on cotton seeds

Observações sobre o hábito de crescimento de Colletotrichum gossypii e C. gossypii var. cephalosporioides em sementes de algodoeiro, inoculadas artificialmente e incubadas a 20-22°C durante cinco a sete dias, evidenciaram as seguintes características: (a) em raízes: acérvulos isolados ou em grupos, massa conidial cor branco-suja, alaranjada ou salmão (mais freqüente), setas marrom-escuras, muitas vezes encobertas pela matriz gelatinosa; conídios produzidos também no micélio aéreo ou nas extremidades das setas, onde ficam aderidos, formando pequenos aglomerados; (b) na superfície das sementes: conídios produzidos nos ápices de setas que emergem diretamente do tegumento, ficando aderidos uns aos outros, formando cachos, semelhantes a cadeias, que são vistos brilhantes sob a luz, em estereomicroscópio. As setas férteis são formadas também no micélio aéreo que recobre as sementes, geralmente após cinco dias de incubação. Os acérvulos com massa conidial raramente são visíveis, exceto em sementes danificadas ou mortas. Como característica de C. gossypii, observou-se que as sementes exibem, de modo geral, uma coloração rosada, em decorrência da abundante esporulação; a ausência ou escassez de micélio aéreo e as setas curtas resultam em um crescimento rente ao tegumento e aspecto compacto. Comparativamente, nas sementes com C. gossypii var. cephalosporioides, as setas são mais longas e menos densas; o micélio aéreo com setas férteis ocorre com mais freqüência, conferindo às sementes tonalidades acinzentadas e aspecto solto. A constatação de setas férteis em lesões foliares de ramulose evidencia que, no campo, essas estruturas podem funcionar como autênticos conidióforos, desempenhando um importante papel epidemiológico, ao possibilitar a disseminação dos esporos pelos ventos, a longas distâncias.<br>The growth habit of Colletotrichum gossypii and C. gossypii var. cephalosporioides on artificially inoculated cotton seeds and incubated at 20-22°C during 5 to 7 days, showed the following characteristics: (a) on roots: single or coalesced acervuli, conidial mass dirty white, orange or salmon (frequently), dark brown setae, often covered by the gelatinous matrix; conidia also produced from the aerial mycelium or from the apex of the setae, where some of them remain bound to each other, forming small heads; (b) seed surface: the setae arise directly from the seed coat, bearing conidia in the apex. These conidia are seen slicked together, forming clusters resembling chains, bright under stereomicroscope light. The fertile setae are also produced from the aerial mycelium that cover the seeds, generally 5 days after incubation. The acervuli with conidial matrix are rarely visible, except for the embrionary tissues, under the damaged seed coat or for dead seeds. The seeds with C. gossypii show generally a light pink shade due to the abundant sporulation that cover the setae. The mycelium over the seeds is scanty or absent and the short setae appear flat on the seeds, resulting in a compact growth. In contrast, on seeds with C. gossypii var. cephalosporioides, the setae are taller and less dense. The aerial mycelium with fertile setae is frequent, giving to the seed a grayish and loose, fluffy appearance. The presence of fertile setae also could be seen on foliar lesions of ramulosis. This fact suggest that under field conditions these structures have a function of authentic conidiophores, which play an important epidemiological role on long distance spore dissemination by the wind

Macrolevel Model Development for Safety Assessment of Road Network Structures

Traffic analysis zones are often delineated by the existing street network. This practice may result in a considerable number of crashes on or near zonal boundaries. Although the traditional macrolevel approach to crash modeling assigns zonal attributes to all crashes that occur within the zonal boundary, this paper acknowledges the inaccuracy resulting from relating crashes on or near the boundary of the zone to merely the attributes of that zone. This paper proposes a novel approach to account for the spatial influence of neighboring zones on crashes that occur specifically on or near the zonal boundaries. Predictive models for pedestrian crashes per zone were developed with a hierarchical Bayesian framework and with separate predictor sets for boundary and interior (nonboundary) crashes. The hierarchical Bayesian model that accounted for spatial autocorrelation was found to have better goodness-of-fit measures than did models that had no specific consideration for crashes located on or near the boundaries. In addition, the models were able to capture some unique predictors associated explicitly with interior and boundary-related crashes. For example, two variables, total roadway length with a posted speed of 35 mph and long-term parking cost, were not statistically significant from zero in the interior crash model but were significantly different from zero at the 95% level in the boundary crash model