10,039 research outputs found
The annihilation of virtual photons into pseudoscalar mesons
We investigate the possibility to constrain the pion distribution amplitude
from the gamma* gamma* -> pi transition. For a surprisingly large range in the
two photon virtualities we find that the transition form factor is essentially
independent of the distribution amplitude. This in turn entails a
parameter-free prediction of QCD. The gamma* gamma* -> eta, eta' form factors
are also briefly discussed. We estimate that experimental studies might be
feasible at the existing e+ e- experiments BaBar, Belle, and CLEO.Comment: 22 pages latex, 9 figure
Two-Photon Annihilation into Baryon-Antibaryon Pairs
We study the handbag contribution to two-photon annihilation into
baryon-antibaryon pairs at large energy and momentum transfer. We derive
factorization of the process amplitude into a hard gamma gamma -> q qbar
subprocess and form factors describing the soft q qbar -> B Bbar transition,
assuming that the process is dominated by configurations where the (anti)quark
approximately carries the full momentum of the (anti)baryon. The form factors
represent moments of time-like generalized parton distributions, so-called B
Bbar distribution amplitudes. A characteristic feature of the handbag mechanism
is the absence of isospin-two components in the final state, which in
combination with flavor symmetry provides relations among the form factors for
the members of the lowest-lying baryon octet. Assuming dominance of the handbag
contribution, we can describe current experimental data with form factors of
plausible size, and predict the cross sections of presently unmeasured B Bbar
channels.Comment: 20 pages latex, 4 figures. v2: minor clarifications, references
update
General purpose airborne simulator - Conceptual design report
General purpose airborne simulator with capabilities for model controlled and response feedback types of variable stability operatio
Transformations to achieve the Sustainable Development Goals Includes the SDG Index and Dashboards. Sustainable Development Report 2019
The Sustainable Development Report 2019 presents an updated SDG Index and Dashboards with a refined assessment
of countries’ distance to SDG targets. The report has been successfully audited for the first time by the European Commission
Joint Research Centre. New indicators have been included, primarily to refine the indicator selection on agriculture, diets, gender
equality and freedom of speech. We have also added more metrics for international spillovers, including on fatal work accidents.
A new website and data visualization tools are available (http://sustainabledevelopment.report).
Once again, Nordic countries – Denmark, Sweden and Finland – top the SDG Index. Yet, even these countries
face major challenges in implementing one or several SDGs. No country is on track for achieving all 17 goals with major
performance gaps even in the top countries on SDG 12 (Responsible Consumption and Production), SDG 13 (Climate
Action), SDG 14 (Life Below Water) and SDG 15 (Life on Land). Income and wealth inequalities, as well as gaps in health
and education outcomes by population groups also remain important policy challenges in developing and developed
countries alike.
The Sustainable Development Report 2019 generates seven major findings:
1. High-level political commitment to the SDGs is falling short of historic promises
In September 2019, heads-of-states and governments will convene for the first time in person at the UN in New York to
review progress on their promises made four years after the adoption of the 2030 Agenda. Yet, our in-depth analyses show
that many have not taken the critical steps to implement the SDGs. Out of 43 countries surveyed on SDG implementation
efforts, including all G20 countries and countries with a population greater than 100 million, 33 countries have endorsed
the SDGs in official statements since January 1st, 2018. Yet in only 18 of them do central budget documents mention the
SDGs. This gap between rhetoric and action must be closed.
2. The SDGs can be operationalized through six SDG Transformations
SDG implementation can be organized along the following Transformations: 1. Education, Gender, and Inequality; 2. Health,
Wellbeing, and Demography; 3. Energy Decarbonization and Sustainable Industry; 4. Sustainable Food, Land, Water, Oceans;
5. Sustainable Cities and Communities; and 6. Digital Revolution for Sustainable Development. The transformations respect
strong interdependencies across the SDGs and can be operationalized by well-defined parts of governments in collaboration
with civil society, business, and other stakeholders. They must be underpinned and guided by the principles of Leave No One
Behind and Circularity and Decoupling of resource use from human wellbeing.
3. Trends on climate (SDG 13) and biodiversity (SDG 14 and SDG 15) are alarming
On average, countries obtain their worst scores on SDG 13 (Climate Action), SDG 14 (Life Below Water) and SDG 15 (Life on
Land). No country obtains a “green rating” (synonym of SDG achieved) on SDG 14 (Life Below Water). Trends on greenhouse
gas emissions and, even more so, on threatened species are moving in the wrong direction. These findings are in line with
the recent reports from the IPCC and IPBES on climate change mitigation and biodiversity protection, respectively.
4. Sustainable land-use and healthy diets require integrated agriculture, climate and health policy interventions
Land use and food production are not meeting people’s needs. Agriculture destroys forests and biodiversity, squanders
water and releases one-quarter of global greenhouse-gas emissions. In total, 78% of world nations for which data are
available obtain a “red rating” (synonym of major SDG challenge) on sustainable nitrogen management; the highest
number of “red” rating across all indicators included in the report. At the same time, one-third of food is wasted, 800 million
people remain undernourished, 2 billion are deficient in micronutrients, and obesity is on the rise. New indicators on
nations’ trophic level and yield gap closure highlight the depth of the challenge. Transformations towards sustainable landuse
and food systems are required to balance efficient and resilient agriculture and forestry with biodiversity conservation
and restoration as well as healthy diets
Development, Implementation, And Evaluation Of An Academic Advising Model For Use In The Small, Private College
Practical Bible Training School (PBTS! is a small, private college in need of improved academic advising services. The purpose of this project was to identify strategies in academic advising that would be appropriate for implementation in the small, private college setting, to develop an academic advising system that would address problems experienced at PBTS, and to implement and evaluate such a system through a trial model. A successful program would necessitate limited expansion of resources or personnel, applicability on an institution-wide basis, and demonstrated improvement in adviser and student satisfaction. A trial model was developed and implemented during the 1989-90 academic year. It consisted of pre- and in-service training for advisers, intrusive advising for high-risk students, dissemination of profile data on new students to advisers, streamlined registration and group advising, development of advising support materials, placement of an advising file in the library containing appropriate support materials for student use, and evaluation of advising services by both advisers and students. The model was evaluated through two twenty-five item, pretest-posttest questionnaires. One questionnaire assessed the satisfaction of the ten academic advisers with advising services and support; the other assessed the satisfaction of all returning students {approximately 60). The questionnaires were administered as a pretest at the beginning of the fall 1989 semester, and as a posttest at the end of the spring 1990 semester. An advising preferences survey was also administered to advisers and both returning and new students at the end of the spring 1990 semester. The implementation of the academic advising trial model was responsible for a substantial reduction in the number of advising areas rated “poor” or very poor” by over ten percent of academic advisers or returning students. Overall increase in the mean and median levels of satisfaction were found for both academic advisers and students. Statistically significant improvements in adviser satisfaction were four in fifteen of the twenty-five areas examined, and in returning student satisfaction in seventeen of the twenty-five analysis areas. Significant improvements in adviser satisfaction included the following: timely notification of advising assignments, information about prior abilities of advisees, tracking of the academic progress of high-risk advisees, awareness of advisee plans to drop a course or withdraw from school, information about support services and course options, sufficient resources to help advisees, satisfaction with registration and pre-registration, and satisfaction with the level of institutional support and recognition for advisers. Student satisfaction significantly improved for adviser clarification of recommendations and college policies and procedures, adviser knowledge of program requirements, tracking of what courses the advisee needed, and help in selecting appropriate courses, and adviser tracking of academic progress and help with academic problems. Significant improvements were also found for discussion of college support services, adviser availability, friendship, and genuine concern about the welfare and growth of the advisee, and the advisee\u27s overall experience with advising. Both students and advisers preferred procedures and materials used in the advising trial model over the former advising system by a significant margin. Former procedures were preferred in only one of the twenty-·six areas modified (advisers preferred that students get academic petition forms from the academic office instead of the adviser). It was recommended that PBTS adopt a permanent advising program based on the components of the advising trial model
Hard exclusive wide-angle processes
In this talk the handbag approach to hard exclusive wide-angle processes is
reviewed and applications, as for instance two-photon annihilations into pairs
of mesons, are discussed.Comment: 11 pages, 8 figures, using latex2e, invited talk presented at Meson
2012, Cracow 201
Corporate Adaptation: from Wholesale to Direct to Consumer Shipments
Technology has changed the way consumers\u27 buy that has caused a shift in the traditional channels of distribution. This paper reviews the role of a giftware wholesaler and the feasibility of serving in the internet distribution by offering direct to consumer shipments. lt will identify and analyze benchmarks in fulfillment set by Amazon as well as review potential options by considering the margins of both the wholesaler and the virtual retailer. The research will conduct two experiments that connect the wholesaler in the new distribution by accommodating direct consumer shipments: 1. Engaging Amazon Corporation in selling the wholesalers product and shipping direct to their customer. 2. Offering a conservative drop ship program to internet retailers. This paper will also address leadership issues that were prevalent in the wholesaler\u27s organization and identify necessary change as the organization prepares to build for the future
Polarization dependence of x-ray absorption spectra in Na_xCoO_2
In order to shed light on the electronic structure of Na_xCoO_2, and
motivated by recent Co L-edge X-ray absorption spectra (XAS) experiments with
polarized light, we calculate the electronic spectrum of a CoO_6 cluster
including all interactions between 3d orbitals. We obtain the ground state for
two electronic occupations in the cluster that correspond nominally to all O in
the O^{-2} oxidation state, and Co^{+3} or Co^{+4}. Then, all excited states
obtained by promotion of a Co 2p electron to a 3d electron, and the
corresponding matrix elements are calculated. A fit of the observed
experimental spectra is good and points out a large Co-O covalency and cubic
crystal field effects, that result in low spin Co 3d configurations. Our
results indicate that the effective hopping between different Co atoms plays a
major role in determining the symmetry of the ground state in the lattice.
Remaining quantitative discrepancies with the XAS experiments are expected to
come from composition effects of itineracy in the ground and excited states.Comment: 10 pages, 4 figure
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