Evaluation of the capability of local helioseismology to discern between monolithic and spaghetti sunspot models

The helioseismic properties of the wave scattering generated by monolithic and spaghetti sunspots are analyzed by means of numerical simulations. In these computations, an incident f or p1 mode travels through the sunspot model, which produces absorption and phase shift of the waves. The scattering is studied by inspecting the wavefield, computing travel-time shifts, and performing Fourier-Hankel analysis. The comparison between the results obtained for both sunspot models reveals that the differences in the absorption coefficient can be detected above noise level. The spaghetti model produces an steep increase of the phase shift with the degree of the mode at short wavelengths, while mode-mixing is more efficient for the monolithic model. These results provide a clue for what to look for in solar observations to discern the constitution of sunspots between the proposed monolithic and spaghetti models.Comment: Accepted for publication in The Astrophysical Journa

Helioseismic holography of simulated sunspots: magnetic and thermal contributions to travel times

Wave propagation through sunspots involves conversion between waves of acoustic and magnetic character. In addition, the thermal structure of sunspots is very different than that of the quiet Sun. As a consequence, the interpretation of local helioseismic measurements of sunspots has long been a challenge. With the aim of understanding these measurements, we carry out numerical simulations of wave propagation through sunspots. Helioseismic holography measurements made from the resulting simulated wavefields show qualitative agreement with observations of real sunspots. We use additional numerical experiments to determine, separately, the influence of the thermal structure of the sunspot and the direct effect of the sunspot magnetic field. We use the ray approximation to show that the travel-time shifts in the thermal (non-magnetic) sunspot model are primarily produced by changes in the wave path due to the Wilson depression rather than variations in the wave speed. This shows that inversions for the subsurface structure of sunspots must account for local changes in the density. In some ranges of horizontal phase speed and frequency there is agreement (within the noise level in the simulations) between the travel times measured in the full magnetic sunspot model and the thermal model. If this conclusion proves to be robust for a wide range of models, it would suggest a path towards inversions for sunspot structure.Comment: Accepted for publication in The Astrophysical Journa

A study of beryllium and beryllium-lithium complexes in single crystal silicon

When beryllium is thermally diffused into silicon, it gives rise to acceptor levels 191 MeV and 145 meV above the valence band. Quenching and annealing studies indicate that the 145-MeV level is due to a more complex beryllium configuration than the 191-MeV level. When lithium is thermally diffused into a beryllium-doped silicon sample, it produces two acceptor levels at 106 MeV and 81 MeV. Quenching and annealing studies indicate that these levels are due to lithium forming a complex with the defects responsible for the 191-MeV and 145-MeV beryllium levels, respectively. Electrical measurements imply that the lithium impurity ions are physically close to the beryllium impurity atoms. The ground state of the 106-MeV beryllium level is split into two levels, presumably by internal strains. Tentative models are proposed

Collective Fluorescence Enhancement In Nanoparticle Clusters

Many nanoscale systems are known to emit light intermittently under continuous illumination. In the fluorescence of single semiconductor nanoparticles, the distributions of bright and dark periods (\u27on\u27 and \u27off\u27 times) follow Levy statistics. Although fluorescence from single-quantum dots and from macroscopic quantum dot ensembles has been studied, there has been little study of fluorescence from small ensembles. Here we show that blinking nanorods (NRs) interact with each other in a cluster, and the interactions affect the blinking statistics. The on-times in the fluorescence of a NR cluster increase dramatically; in a cluster with N NRs, the maximum on-time increases by a factor of N or more compared with the combined signal from N well-separated NRs. Our study emphasizes the use of statistical properties in identifying the collective dynamics. The scaling of this interaction-induced increase of on-times with number of NRs reveals a novel collective effect at the nanoscale

I\u27m Only Sixteen

I\u27m only sixteen, \u27tis a nice little age,I would not be younger or older,Already I\u27ve conn\u27d over Love\u27s mystic page,And warm\u27d when I should have grown colder.I would like to be married,But wedlock, they say, Has troubles which I\u27ve never seen,So, I\u27d rather not barter my freedom away,For I\u27ve only just enter\u27d sixteen. I hate an old maid yet I don\u27t wish to wedUntil I have jilted my dozens;And the beaux who had been by my glances misled,I\u27d give to my young country cousins. Make hay while the sun shines, so wisely they say,Mine\u27s bright, and my pasture is green;I\u27ll think of November though blooming in May,For I\u27ve only just enterd sixteen. I\u27ve done with young fops they are playthings at best,And please while around you they flutter;The schoolgirls are getting to be quite a pest,And I warmly detest bread and butter.I can smile on a man if he\u27s not quite too old,Has whiskers is noble in mien;And i would not object to the music of gold,For I\u27ve only just enter\u27d sixteen

Evolution of Preprofessional Pharmacy Curricula

Objectives. To examine changes in preprofessional pharmacy curricular requirements and trends, and determine rationales for and implications of modifications. Methods. Prerequisite curricular requirements compiled between 2006 and 2011 from all doctor of pharmacy (PharmD) programs approved by the Accreditation Council of Pharmacy Education were reviewed to ascertain trends over the past 5 years. An online survey was conducted of 20 programs that required either 3 years of prerequisite courses or a bachelor’s degree, and a random sample of 20 programs that required 2 years of prerequisites. Standardized telephone interviews were then conducted with representatives of 9 programs. Results. In 2006, 4 programs required 3 years of prerequisite courses and none required a bachelor’s degree; by 2011, these increased to 18 programs and 7 programs, respectively. Of 40 programs surveyed, responses were received from 28 (70%), 9 (32%) of which reported having increased the number of prerequisite courses since 2006. Reasons given for changes included desire to raise the level of academic achievement of students entering the PharmD program, desire to increase incoming student maturity, and desire to add clinical sciences and experiential coursework to the pharmacy curriculum. Some colleges and schools experienced a temporary decrease in applicants. Conclusions. The preprofessional curriculum continues to evolve, with many programs increasing the number of course prerequisites. The implications of increasing prerequisites were variable and included a perceived increase in maturity and quality of applicants and, for some schools, a temporary decrease in the number of applicants

A Study of the Perceptions of Diversity and Inclusion Initiatives in Producing Improved Productive Work Cultures

Organizations today view diversity in the workforce as extending beyond antidiscrimination laws. Diversity in the workplace is viewed as a means for organizations to maintain a competitive edge in the global job market by focusing on inclusion and performance. Organizations have begun to recognize that diversity results in economic benefits when initiatives are aligned with their strategic plans, goals, and core values (U.S. Department of Commerce, 1999). The purpose of this study was to determine the perceptions of departmental personnel regarding the impact of diversity and inclusion initiatives in improving and sustaining productive work cultures. Additionally, this study sought to determine whether a relationship exists between perceptions of departmental personnel and their department’s work culture scores. Findings of the study included the following. Departmental personnel perceived the four survey constructs (Relationship with Team Members, Relationship with Manager, Individual’s Behavior and Attitudes, and Overall Work Culture) as impactful (useful) in improving and sustaining productive work cultures. Qualitative themes resulting from focus groups supported this research question. The only department where there was no significant difference between the managers’ and staff members’ ratings of section 2 of the Diversity and Inclusion Perceptions Survey was Department A. Departments B through E indicated there was a significant difference between the managers’ and staff members’ ratings on section 2 of the Diversity and Inclusion Perceptions Survey. Departmental personnel identified diversity and inclusion initiatives, Workshops and Learning Modules and Team Coaching, as being more impactful (useful) to their work cultures with no significant difference in manager and staff rankings. Lastly, there was a significant relationship between departmental personnel ratings of their perceptions of diversity and inclusion initiatives and work culture Tier scores

Tourism discretionary spending choice behaviour

Studies of tourism demand are numerous. But studies of how consumers apportion discretionary resources to tourism and across other competing categories of discretionary expenditure are non-existent. Therefore, how individuals and households make trade-offs between, or assess the respective utilities of, the various categories of discretionary expenditure and allocate discretionary financial resources, appears to be unknown. This study seeks to address this need by examining discretionary expenditure through choice experiments. The data provide insights into how each type of discretionary expenditure is valued and how each type competes for a share of the discretionary expenditure ‘pie’. We discuss the results with an emphasis on the implications for tourism marketing

New horses for old courses - questioning the limitations of sustainable tourism to supply-driven measures and the nature-based context

It seems a general belief that (1) sustainable tourism is supply-driven, and (2) sustainable tourists are visitors engaging in nature-based travel activities. Results reported in this paper challenge these assumptions. Findings from an online survey indicate that nature-based travel is not solely related to environmentally protective attitudes. Market-driven mechanisms could therefore be used to strengthen ecological sustainable tourism. Only 39 % of respondents classified as ‘Ecologically Caring Tourists’ stated that an intense experience of nature is a motivation for their vacation travel behaviour. The findings indicate two possible directions for the strengthening of sustainable tourism measures: (1) demand-driven mechanisms could be used in addition to supply-side measures to identify and attract groups of tourists with a smaller ecological footprint; (2) the tourism market suitable to increase ecological sustainability is likely to be much larger than assumed by focusing on nature-based tourism only. These findings could be of great benefit to any tourism destination in terms of the development of new tools and the identification of new tourism contexts for managing ecological sustainability