4,383 research outputs found

    Introduction to Library Trends 18 (3) Winter 1970: Problems of Acquisition for Research Libraries

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    Enhancement of Photoemission on P-type GaAs using Surface Acoustic Waves

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    We demonstrate that photoemission properties of GaAs photocathodes (PCs) can be altered by surface acoustic waves (SAWs) generated on the PC surface due to dynamical piezoelectric fields of SAWs. Simulations with COMSOL indicate that electron effective lifetime in p-doped GaAs may increase by a factor of 10x to 20x. It implies a significant, by a factor of 2x to 3x, increase of quantum efficiency (QE) for GaAs PCs. Essential steps in device fabrication are demonstrated, including deposition of an additional layer of ZnO for piezoelectric effect enhancement, measurements of I-V characteristic of the SAW device, and ability to survive high-temperature annealing.Comment: 5 pages, 4 figure

    Effects of burying and removing dead leaves from the ground on the development of scab epidemics in an apple organic orchard.

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    Ascospores produced on scabbed leaves in the leaf litter constitute the primary inoculum causing scab infections in apple orchards during the year. The trial, carried out in a commercial organic orchard, permitted to evaluate the effects of the removal of dead leaves located on the inter-row supplemented by the ploughing in of the leaves left on the row, on the development of scab epidemics. From the first recorded contamination to harvest time, lesions on leaves and fruits were counted to determine reduction in disease incidence and severity, compared with the untreated plots. Disease severity as a function of the distance from the untreated plot was also observed, to evaluate the spore dispersal gradient within the orchard. The results show that the ploughing in and the removal of the litter reduced disease incidence by 62% on leaves, and by almost 82% on fruits to harvest. Moreover, measurements of the dispersal gradient show that the spores do not disperse, or little, beyond 20m of the untreated zone

    Prospectives

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    Optical versus video see-through mead-mounted displays in medical visualization

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    We compare two technological approaches to augmented reality for 3-D medical visualization: optical and video see-through devices. We provide a context to discuss the technology by reviewing several medical applications of augmented-reality research efforts driven by real needs in the medical field, both in the United States and in Europe. We then discuss the issues for each approach, optical versus video, from both a technology and human-factor point of view. Finally, we point to potentially promising future developments of such devices including eye tracking and multifocus planes capabilities, as well as hybrid optical/video technology

    Spontaneous symmetry breaking in a two-lane model for bidirectional overtaking traffic

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    First we consider a unidirectional flux \omega_bar of vehicles each of which is characterized by its `natural' velocity v drawn from a distribution P(v). The traffic flow is modeled as a collection of straight `world lines' in the time-space plane, with overtaking events represented by a fixed queuing time tau imposed on the overtaking vehicle. This geometrical model exhibits platoon formation and allows, among many other things, for the calculation of the effective average velocity w=\phi(v) of a vehicle of natural velocity v. Secondly, we extend the model to two opposite lanes, A and B. We argue that the queuing time \tau in one lane is determined by the traffic density in the opposite lane. On the basis of reasonable additional assumptions we establish a set of equations that couple the two lanes and can be solved numerically. It appears that above a critical value \omega_bar_c of the control parameter \omega_bar the symmetry between the lanes is spontaneously broken: there is a slow lane where long platoons form behind the slowest vehicles, and a fast lane where overtaking is easy due to the wide spacing between the platoons in the opposite direction. A variant of the model is studied in which the spatial vehicle density \rho_bar rather than the flux \omega_bar is the control parameter. Unequal fluxes \omega_bar_A and \omega_bar_B in the two lanes are also considered. The symmetry breaking phenomenon exhibited by this model, even though no doubt hard to observe in pure form in real-life traffic, nevertheless indicates a tendency of such traffic.Comment: 50 pages, 16 figures; extra references adde

    PENGARUH BUDAYA ORGANISASI TERHADAP KINERJA KARYAWAN PT BOSOWA BERLIAN MOTOR KUPANG

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    Penelitian ini dilakukan di PT Bosowa Berlian Motor Kupang. Tujuannya untuk mengetahui pengaruh budaya organisasi terhadap kinerja karyawan PT Bosowa Berlian Motor Kupang. Penelitian ini merupakan penelitian kuantitatif dengan jumlah sampel 37 karyawan dengan menggunakan teknik sampling jenuh. Teknik analisis data yang digunakan adalah analisis deskriptif dan analisis inferensial. Hasil penelitian menunjukkan bahwa budaya organisasi berpengaruh signifikan terhadap kinerja karyawan PT Bosowa Berlian Motor Kupang. Bagi PT Bosowa Berlian Motor Kupang dalam rangka menjaga dan meningkatkan budaya organisasi yang terdapat pada perusahaan dan kinerja karyawan sehingga tetap pada kriteria penilaian yang sangat tinggi dan harus memperhatikan faktor lain yang dapat dikembangkan lebih lanjut oleh PT Bosowa Berlian Motor Kupang
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