3,807 research outputs found
Variable and reversible quantum structures on a single carbon nanotube
The band gap of a semiconducting single wall carbon nanotube decreases and
eventually vanishes leading to metalization as a result of increasing radial
deformation. This sets in a band offset between the undeformed and deformed
regions of a single nanotube. Based on the superlattice calculations, we show
that these features can be exploited to realize various quantum well structures
on a single nanotube with variable and reversible electronic properties. These
quantum structures and nanodevices incorporate mechanics and electronics.Comment: 7 pages, 4 figures, To be appear in PR
Collisional Damping of Giant Monopole and Quadrupole Resonances
Collisional damping widths of giant monopole and quadrupole excitations for
Sn and Pb at zero and finite temperatures are calculated within
Thomas-Fermi approximation by employing the microscopic in-medium
cross-sections of Li and Machleidt and the phenomenological Skyrme and Gogny
forces, and are compared with each other. The results for the collisional
widths of giant monopole and quadrupole vibrations at zero temperature as a
function of the mass number show that the collisional damping of giant monopole
vibrations accounts for about 30-40% of the observed widths at zero
temperature, while for giant quadrupole vibrations it accounts for only 20-30%
of the observed widths of zero temperature.Comment: RevTex, 12 pages, 6 PS figure
The effect of feeding frequency on growth performance and body composition in juvenile rainbow trout (Oncorhynchus mykiss) reared in cold seawater
This study was done to investigate the effects of different feeding frequencies on the growth, feed efficiency and specific growth rate (%) of juvenile of rainbow trout (Oncorhynchus mykiss, weight 16.44±0.22 g) rearing in cold sea water conditions (5.8 to 9.3°C; 17 to 18 ppt). Fish were fed on a commercial feed to the apparent satiation twice a day (Control), six times every day (TD6), four times every day (TD4) and three times every day (TD3) for 8 weeks of the trial. The fish fed to satiation in all the experimental groups. Weight gain, growth rate, feed intake and final body weight decreased with reduction of feeding frequency from six times daily to two times daily. The fish fed at TD6 had relatively high apparent net protein retention and better feed conversion efficiency compared with the fish fed at the control, TD4 and TD3. The feeding frequency had significant effect on the crude lipid, crude protein but not moisture and crude ash proximate composition of rainbow trout. It was recommended that six meals per day was the optimal feeding frequency for juvenile rainbow trout reared in cold sea water at 5.8 to 9.3°C, 17 to 18 ppt.Key words: Feeding frequencies, growth, body composition, sea water, Oncorhynchus mykiss
Metal nanoring and tube formation on carbon nanotubes
The structural and electronic properties of aluminum covered single wall
carbon nanotubes (SWNT) are studied from first-principles for a large number of
coverage. Aluminum-aluminum interaction that is stronger than aluminum-tube
interaction, prevents uniform metal coverage, and hence gives rise to the
clustering. However, a stable aluminum ring and aluminum nanotube with well
defined patterns can also form around the semiconducting SWNT and lead to
metallization. The persistent current in the Al nanoring is discussed to show
that a high magnetic field can be induced at the center of SWNT.Comment: Submitted to Physical Review
A Recombinant PvpA Protein-Based Diagnostic Prototype for Rapid Screening of Chicken Mycoplasma gallisepticum infections
Cataloged from PDF version of article.Mycoplasma gallisepticum is the primary agent of chronic respiratory disease causing important economic losses in the poultry industry. Serological monitoring is essential to maintain mycoplasma-free breeder flocks and often complicated by the cross-reactions between different mycoplasma species. To overcome serological cross-reactions, a large fragment of the M. gallisepticum PvpA cytadhesin, species-specific surface-exposed protein, was produced in E. coli as a recombinant protein (rPvpA336) and used as a potential diagnostic antigen. The rPvpA336 protein possesses 336 mycoplasma-specific amino acids with relative molecular weight of 44 kDa. A deletion region of 37 amino acids was identified when compared to the wild-type PvpA protein. Immunoreactivity of the rPvpA336 protein has been demonstrated by Western blot analysis with M. gallisepticum-positive and -negative chicken sera. Furthermore, an enzymatic rapid immunofiltration assay (ERIFA) prototype based on the rPvpA336 protein has been developed and its species-specific detection capability has been demonstrated by using M. gallisepticum and/or M. synoviae-positive and -negative chicken sera. In addition to its species-specificity, the ERIFA prototype presents certain advantages such as rapidity, field-applicability and cost-effectiveness. Therefore, these advantages would make the prototype a species-specific rapid diagnostic tool of choice in the field and limited laboratory conditions for screening M. gallisepticum infections. © 2007 Elsevier B.V. All rights reserved
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KC 4.1: Rural heritage and urban-rural linkages in the ICOMOS SDGs Policy Guidance
This Knowledge Café aims to provide a discussion platform to contribute to the drafting of a new ICOMOS SDGs Policy Guidance, from the perspective of rural heritage, landscapes and rural-urban linkages. While 50%-plus of global populations are urban dwellers, we tend to forget that the other half dwell in rural places.
One of the 7 Priority Actions of the ICOMOS SDGs Working Group in 2018 is the preparation of a consolidated policy statement, as an effective tool for advocacy and communication to wider society and the development world. Based on the need to boost the role of cultural heritage in sustainable development processes, this would be a robust Policy Guidance document, serving to improve the recognition of the role of cultural heritage protection, particularly as defined by SDG 11.4 and the New Urban Agenda. The ICOMOS SDGs Working Group aims to launch this document at the 10th World Urban Forum in 2020 and at the High-Level Political Forum in 2021.
The new Policy Guidance aims to emphasize âheritage as a resource, a strategic opportunityâ, using the framework of the 3 dimensions of sustainability, economic, social, environmental, and propose adding the 4th dimension of âcultureâ through an appropriate approach. The document should be based on solid scientific expertise sourced from ICOMOS membership. The Symposium on Rural Heritage: Landscapes and Beyond is a prime opportunity to involve some of this membership, ensuring a diverse and inclusive range of expertise in heritage informs the Policy Guidance. Rural heritage and landscapes, including rural-urban linkages, have great relevance for the intersection of cultural heritage and sustainable development, touching on many SDGs and issues raised in the New Urban Agenda, not to mention the Historic Urban Landscape Recommendation. To cite some examples of this inter-connectedness, the âinter-related categories of continuity and changeâ addressed during the Symposium, provide the following links:
- under âRural Cultureâ to SDG 11.4 (change management for tangible rural heritage), SDG 1.5, 2.4, 11.5, 11.b, 13.1 (risk of loss of intangible rural traditions/ practices), SDG 8.9, SDG 12.b (rural cultural tourism), SDG 16.7, 16.a, 17.9, 17.15, 17.17 (identity of people and places);
- under âRural economicsâ to SDG 1 (poverty eradication), SDG2 (food security), SDG3 (rural agricultural heritage), SDG 8 (improvement of markets and opportunities for rural traditional tools, techniques and rural heritage tourism), SDG 8 (infrastructure, services to small enterprises), SDG 11 (spatial form, territorial policies);
- under âRural Environmentâ to SDG 6 (water), 13 and 15 (desertification, climate-induced severe weather events, biodiversity, forest management); and
- under âRural Societyâ to SDG 1 (poverty alleviation) SDG 2 (agriculture), SDG 3.8, 3.c (health services), SDG 16, 17 (bottom-up governance).
- Some case studies from âMoroccan Rural Heritageâ can be proposed during the session from participants who may have relevant knowledge, to demonstrate these links.
The Knowledge CafĂ© will feature two speakers, Ege Yildirim and Patricia OâDonnell, giving the conceptual framework of the session, followed by Ilaria Rosetti presenting the method of open discussion, whereby breakout groups (e.g. 3-4 groups of 5-6) can discuss the links of rural heritage issues to the various 17 Goals and Targets under them, concluding with short reporting from each group, to be compiled and disseminated later by the conveners
The effect of orthodontic extraoral appliances on depression and the anxiety levels of patients and parents
Background: Psychosocial consequences and postâoperative anxiety in patients after fixed orthodontic treatment are important parameters that must be evaluated by clinicians not to effect patient and their parentâs psychosocial mood negatively.Objective: The aim of this study was to evaluate the changes in depression and anxiety levels of orthodontic patients and their parents before the extraoral appliance therapy, and at a 1âyear followâup.Materials and Methods: Patients and one of their parents responded to a series of questionnaires and evaluation scales in order to assess depression and anxiety levels. Two groups of patients and their parents were surveyed; one group that had not yet embarked on the treatment and another that had commenced extraâoral appliance therapy 1 year prior to the study.Results: The 1âyearâtreatment group scored significantly higher than the preâtreatment group on the depression scale and the traitâanxiety scale. Stateâtrait anxiety inventory scores did not differ significantly between the groups. The parents of the 1âyearâtreatment group also scored significantly higher on the Beck depression inventory than those of the preâtreatment group.Conclusion: The results of this study emphasize the need for due consideration of psychological parameters before and during treatment with extraâoral appliances, particularly with regard to depression and anxiety.Key words: Anxiety, depression, exoral appliance
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