New data acquisition system records bearing measurements directly

Digital data acquisition system records steady state and dynamic data of bearing and shaft displacement. Elliptical orbits formed can be reconstructed and the data reduced automatically. System also reads pressures, temperatures, flows, and torque during any one data scan

Linac-based free electron laser

A basic treatment of the principle of the linac-driven free-electron laser (FEL) is given. The first part of the paper describes the FEL in low-gain approximation, and in the second part the high-gain FEL theory is given. The majority of the treatment describes FELs in one dimensional approximation, neglecting effects by diffraction of radiation and by electron beam emittance. Only in the final section a few remarks on these issues are given. The ambition of the paper is by no means any progress in FEL theory but a clear presentation of basic FEL theory concepts with explicit derivation of the formulae from first principles

New developments on free electron lasers based on self-amplified spontaneous emission

After a brief introduction to the basic concept of Free Electron Lasers operating in the Self-Amplified Spontaneous Emission (SASE) mode, the paper presents the rapid progress achieved during the past 3 years in successfully proving this FEL process at shorter and shorter wavelengths, meanwhile reaching 80 nm. The technical challenges are discussed to be overcome in building FEL facilities for wavelengths much below the visible, and these challenges are compared with the present state-of-the-art. Finally, approved and proposed SASE FEL projects are briefly summarized

Lišajevi kao biomonitori: globalni, regionalni i lokalni aspekti

Lichens, a symbiosis of fungi and algae, have been widely used for biological monitoring of environmental quality. As some lichen species are virtually cosmopolitan organisms, they may be used for a survey of organic, inorganic, or radioactive contaminants on more or less a global scale, as well as for regional comparisons, and certainly at a more local scale. Some examples will be given for the use of different lichen species (Usnea ssp., Lecanora muralis, Pseudevernia furfuracea and Xanthoria parietina) in biological monitoring of trace elements in various contexts.Lišajevi, simbioza gljiva i algi, bili su u prošlosti u širokoj uporabi za biološki monitoring kakvoće okoliša. Kako određene vrste lišajeva predstavljaju gotovo kozmopolitske organizme, može ih se koristiti za praćenje organskih, anorganskih i radioaktivnih onečišćivala na globalnoj razini, ali svakako i na regionalnim i lokalnim razinama. U radu se daje nekoliko primjera korištenja različitih vrsta lišajeva za biološki monitoring elemenata u tragovima u raznim sustavima

InP-quantum dots in Al0.20Ga0.80InP with different barrier configurations

Systematic ensemble photoluminescence studies have been performed on type-I InP-quantum dots in Al0.20Ga0.80InP barriers, emitting at approximately 1.85 eV at 5 K. The influence of different barrier configurations as well as the incorporation of additional tunnel barriers on the optical properties has been investigated. The confinement energy between the dot barrier and the surrounding barrier layers, which is the sum of the band discontinuities for the valence and the conduction bands, was chosen to be approximately 190 meV by using Al0.50Ga0.50InP. In combination with 2 nm thick AlInP tunnel barriers, the internal quantum efficiency of these barrier configurations can be increased by up to a factor of 20 at elevated temperatures with respect to quantum dots without such layers.Comment: physica status solidi (c) (Proceedings of QD 2008

The potential demand for an HIV/AIDS vaccine in Brazil

This study assesses the potential demand by the public sector for a preventive HIV/AIDS vaccine in Brazil and the costs of alternative strategies for a vaccination program. Brazil has a mature AIDS epidemic: the percent of the population living with HIV or AIDS (about 0.6 percent of adults) is not as high as in other severely affected developing countries, but infection rates in specific risk groups in the population are very high and HIV has spread beyond these groups into the general population of low-risk individuals. Preventive HIV/AIDS vaccines are still in the testing stage. The characteristics of the first vaccines developed, in terms of their efficacy, duration of effectiveness, ease of administration, and price, are still unknown. But the potential benefits of such a vaccine in Brazil would be high. The study reviews the cost and impact of HIV/AIDS in Brazil, in terms of disease and economic burden, as a proxy for the benefits of an HIV/AIDS vaccine. The epidemiology of AIDS and Brazil's experience with immunization coverage with other vaccines are used to assess the number of vaccines, delivery strategies, and possible costs of an HIV/AIDS immunization program in Brazil, assuming the availability of a 100 percent effective AIDS vaccine that lasts a lifetime under different pricing and dosing assumptions. A low-cost, highly effective vaccine would likely be affordable to an upper-middle-income country like Brazil and yield large benefits from a policy of universal, publicly subsidized immunization. But if prices are higher and the impact less favorable, the costs and effects would have to be compared with other AIDS prevention programs or other health interventions. Both political and economic considerations will likely figure into public policy on HIV/AIDS vaccination, when such a vaccine is developed.Disease Control&Prevention,Early Child and Children's Health,Health Economics&Finance,Public Health Promotion,Health Monitoring&Evaluation,HIV AIDS,Health Monitoring&Evaluation,Health Economics&Finance,Adolescent Health,Health Indicators

Using the new products margin to predict the industry-level impact of trade reform

This paper develops a methodology for predicting the impact of trade liberalization on exports by industry (3-digit ISIC) based on the pre-liberalization distribution of exports by product (5-digit SITC). Using the results of Kehoe and Ruhl (2013) that much of the growth in trade after trade liberalization is in products that are traded very little or not at all, we predict that industries with a higher share of exports generated by least traded products will experience more growth. Using our methodology, we develop predictions for industry-level changes in trade for the United States and Korea following the U.S.-Korea Free Trade Agreement (KORUS). As a test for our methodology, we show that it performs significantly better than the applied general equilibrium models originally used for the policy evaluation of the North American Free Trade Agreement (NAFTA)

Crystal structure of THEP1 from the hyperthermophile Aquifex aeolicus: a variation of the RecA fold

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract Background aaTHEP1, the gene product of aq_1292 from Aquifex aeolicus, shows sequence homology to proteins from most thermophiles, hyperthermophiles, and higher organisms such as man, mouse, and fly. In contrast, there are almost no homologous proteins in mesophilic unicellular microorganisms. aaTHEP1 is a thermophilic enzyme exhibiting both ATPase and GTPase activity in vitro. Although annotated as a nucleotide kinase, such an activity could not be confirmed for aaTHEP1 experimentally and the in vivo function of aaTHEP1 is still unknown. Results Here we report the crystal structure of selenomethionine substituted nucleotide-free aaTHEP1 at 1.4 Å resolution using a multiple anomalous dispersion phasing protocol. The protein is composed of a single domain that belongs to the family of 3-layer (α/β/α)-structures consisting of nine central strands flanked by six helices. The closest structural homologue as determined by DALI is the RecA family. In contrast to the latter proteins, aaTHEP1 possesses an extension of the β-sheet consisting of four additional β-strands. Conclusion We conclude that the structure of aaTHEP1 represents a variation of the RecA fold. Although the catalytic function of aaTHEP1 remains unclear, structural details indicate that it does not belong to the group of GTPases, kinases or adenosyltransferases. A mainly positive electrostatic surface indicates that aaTHEP1 might be a DNA/RNA modifying enzyme. The resolved structure of aaTHEP1 can serve as paradigm for the complete THEP1 family.Published versio

Polarization fine-structure and enhanced single-photon emission of self-assembled lateral InGaAs quantum dot molecules embedded in a planar micro-cavity

Single lateral InGaAs quantum dot molecules have been embedded in a planar micro-cavity in order to increase the luminescence extraction efficiency. Using a combination of metal-organic vapor phase and molecular beam epitaxy samples could be produced that exhibit a 30 times enhanced single-photon emission rate. We also show that the single-photon emission is fully switchable between two different molecular excitonic recombination energies by applying a lateral electric field. Furthermore, the presence of a polarization fine-structure splitting of the molecular neutral excitonic states is reported which leads to two polarization-split classically correlated biexciton exciton cascades. The fine-structure splitting is found to be on the order of 10 micro-eV.Comment: 14 pages, 4 figures; the following article has been submitted to Journal of Applied Physics (29th ICPS - invited paper); after it is published, it will be found at http://jap.aip.org