6,669 research outputs found

    Diagnostics of accelerating plasma Semiannual progress report, 1 Mar. - 31 Aug. 1968

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    Plasma diagnostics in electromagnetically driven shock tubes using laser scattering methods as compared to spectroscopic technique

    Intersubband transitions in pseudomorphic InGaAs/GaAs/AlGaAs multiple step quantum wells

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    Intersubband transitions from the ground state to the first and second excited states in pseudomorphic AlGaAs/InGaAs/GaAs/AlGaAs multiple step quantum wells have been observed. The step well structure has a configuration of two AlGaAs barriers confining an InGaAs/GaAs step. Multiple step wells were grown on GaAs substrate with each InGaAs layer compressively strained. During the growth, a uniform growth condition was adopted so that inconvenient long growth interruptions and fast temperature ramps when switching the materials were eliminated. The sample was examined by cross‐sectional transmission electron microscopy, an x‐ray rocking curve technique, and the results show good crystal quality using this simple growth method. Theoretical calculations were performed to fit the intersubband absorption spectrum. The calculated energies are in good agreement with the observed peak positions for both the 1→2 and 1→3 transitions

    Exchange coupling between two ferromagnetic electrodes separated by a graphene nanoribbon

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    In this study, based on the self-energy method and the total energy calculation, the indirect exchange coupling between two semi-infinite ferromagnetic strips (FM electrodes) separated by metallic graphene nanoribbons (GNRs) is investigated. In order to form a FM/GNR/FM junction, a graphitic region of finite length is coupled to the FM electrodes along graphitic zigzag or armchair interfaces of width NN. The numerical results show that, the exchange coupling strength which can be obtained from the difference between the total energies of electrons in the ferromagnetic and antiferromagnetic couplings, has an oscillatory behavior, and depends on the Fermi energy and the length of the central region.Comment: 4 pages, 6 figures, International Conference on Theoretical Physics 'Dubna-Nano2008

    Obligations of poor countries in ensuring global justice: The case of Uganda

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    Obligations of global justice rest mainly on the global rich but also to a lesser extent on the global poor. The governments of poor countries are obliged to fulfill requirements of non-aggression, good governance and decency, along with all other requirements which facilitate the achievement of global justice. So far, obligations of poor countries seem to be taken as given yet the behavior of governments in poor countries and occurrences therein attest to the contrary;this suggests a need to mainstream these obligations in discussions about global justice. If poor countries do not live up to these requirements obstacles arise to the realization of global justice; and they act unjustly in relation to citizens of rich countries which provide them with aid. Uganda is taken as a case in point.publishedVersio

    Obligations of low income countries in ensuring equity in global health financing

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    Background. Despite common recognition of joint responsibility for global health by all countries particularly to ensure justice in global health, current discussions of countries’ obligations for global health largely ignore obligations of developing countries. This is especially the case with regards to obligations relating to health financing. Bearing in mind that it is not possible to achieve justice in global health without achieving equity in health financing at both domestic and global levels, our aim is to show how fulfilling the obligation we propose will make it easy to achieve equity in health financing at both domestic and international levels. Discussion. Achieving equity in global health financing is a crucial step towards achieving justice in global health. Our general view is that current discussions on global health equity largely ignore obligations of Low Income Country (LIC) governments and we recommend that these obligations should be mainstreamed in current discussions. While we recognise that various obligations need to be fulfilled in order to ultimately achieve justice in global health, for lack of space we prioritise obligations for health financing. Basing on the evidence that in most LICs health is not given priority in annual budget allocations, we propose that LIC governments should bear an obligation to allocate a certain minimum percent of their annual domestic budget resources to health, while they await external resources to supplement domestic ones. We recommend and demonstrate a mechanism for coordinating this obligation so that if the resulting obligations are fulfilled by both LIC and HIC governments it will be easy to achieve equity in global health financing. Summary. Although achieving justice in global health will depend on fulfilment of different categories of obligations, ensuring inter- and intra-country equity in health financing is pivotal. This can be achieved by requiring all LIC governments to allocate a certain optimal per cent of their domestic budget resources to health while they await external resources to top up in order to cover the whole cost of the minimum health opportunities for LIC citizens.publishedVersio

    Flux pump for HTS rotating machinery applications

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    High Temperature Superconducting (HTS) machines offer several benefits over the conventional machines. With the advent of YBCO materials, research and development in HTS applications has gained significant impetus. The application of flux pump has its own advantages over the conventional mechanism for magnetic field generation in superconductors. This paper reviews few relevant works and presents preliminary results from experiments carried out to provide justification on the application of flux pump for generating magnetic flux in a rotating machine

    The Design of Control Strategy for Blended Series-Parallel Power-Split PHEV – a Simulation Study

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    Electric Vehicles (EVs) have been extensively researched to reduce the fuel consumption and tailpipe emission. The series-parallel power-split Plug-in Electric Vehicle (PHEV) has been considered as one of the most suitable candidates. It contains both an internal combustion engine (ICE) and an electrical storage system (ESS) to achieve a better driving performance. The energy management system (EMS) is significant for a PHEV to improve the efficiency of the whole system. Electric vehicle mode (EV), charging depletion (CD) and charging sustaining (CS) modes will be discussed to build a control strategy in this study. This control strategy will be implemented with the state of charge (SoC) to show its impact through a simulation study

    Effects of engine emissions from high-speed civil transport aircraft: A two-dimensional modeling study, part 2

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    The AER two-dimensional chemistry-transport model is used to study the effect of supersonic and subsonic aircraft operation in the 2010 atmosphere on stratospheric ozone (O3). The results show that: (1) the calculated O3 response is smaller in the 2010 atmosphere compared to previous calculations performed in the 1980 atmosphere; (2) with the emissions provided, the calculated decrease in O3 column is less than 1 percent; and (3) the effect of model grid resolution on O3 response is small provided that the physics is not modified

    Pengaruh Gaya Kepemimpinan Transformasional dan Motivasi terhadap Kinerja Guru Dimediasikomitmen Organisasional (Studi pada Guru- Guru SMA Swasta di Kecamatan Pati)

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    The purpose of this research is to analyze how far the influence of transformational leadership style and motivation onteacher performance mediated organizational commitment in private high school teachers in the District of Pati. Theuse of this research is to clarify and enlarge the previous research about the influence of transformational leadershipstyles and motivation on teacher performance mediated organizational commitment. This research is an explanatoryresearch.The population is 193 teachers in private high schoolin District of Pati. Data analysis starts frominstrumenttest,normality test, muilticolonearitytest, heterocedastisity test, models test,hypothesis test and mediating effect test.The result showed that transformational leadership style has no influence on organizational commitment,motivation hasa positive influence and significant on organizationalcommitment, transformational leadership style has a positiveinfluence and significant on the teacher performance,motivation has a positive influence and significant on teacherperformance, organizational commitment has a positive influence and significant on teacherperformance,organizational commitment is not efective to mediate on the influence of transformational leadership styleon teacher performance, and organizational commitment is proved to mediate the influence of motivation on teacherperformance

    Recurrence of Preeclampsia in Northern Tanzania: A Registry-based Cohort Study.

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    Preeclampsia occurs in about 4 per cent of pregnancies worldwide, and may have particularly serious consequences for women in Africa. Studies in western countries have shown that women with preeclampsia in one pregnancy have a substantially increased risk of preeclampsia in subsequent pregnancies. We estimate the recurrence risks of preeclampsia in data from Northern Tanzania. A prospective cohort study was designed using 19,811 women who delivered singleton infants at a hospital in Northern Tanzania between 2000 and 2008. A total of 3,909 women were recorded with subsequent deliveries in the hospital with follow up through 2010. Adjusted recurrence risks of preeclampsia were computed using regression models. The absolute recurrence risk of preeclampsia was 25%, which was 9.2-fold (95% CI: 6.4 - 13.2) compared with the risk for women without prior preeclampsia. When there were signs that the preeclampsia in a previous pregnancy had been serious either because the baby was delivered preterm or had died in the perinatal period, the recurrence risk of preeclampsia was even higher. Women who had preeclampsia had increased risk of a series of adverse pregnancy outcomes in future pregnancies. These include perinatal death (RR= 4.3), a baby with low birth weight (RR= 3.5), or a preterm birth (RR= 2.5). These risks were only partly explained by recurrence of preeclampsia. Preeclampsia in one pregnancy is a strong predictor for preeclampsia and other adverse pregnancy outcomes in subsequent pregnancies in Tanzania. Women with previous preeclampsia may benefit from close follow-up during their pregnancies
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