Modulation of NTC frequencies by Pc5 ULF pulsations : experimental test of the generation mechanism and magnetoseismology of the emitting surface

Nonthermal continuum (NTC) radiation is believed to be emitted by the conversion of an electrostatic wave into an electromagnetic one, which takes place at the Earth's magnetic equator. It is generally accepted that the frequency of the electrostatic wave at the source meets a local characteristic frequency placed in between two multiples of the electron cyclotron frequency, fce, which results in emission of a narrow band frequency element. In an event on 14 August 2003, we compare oscillations of the central frequency of distinct NTC frequency elements observed from Cluster orbiting near perigee, with simultaneous Pc5 Ultra Low Frequency (ULF) pulsations in the magnetic field observed from the same platform. The latter magnetic perturbations are interpreted as magnetohydrodynamic poloidal waves, where fundamental and second harmonic modes coexist. The NTC oscillation and the fundamental wave have similar periods, but are phase shifted by a quarter of period. From the correlation between both signals, and the proximity of the NTC source (localized via triangulation) with Cluster, we infer that the poloidal perturbations are spatially uniform between the source and the satellites. From the phase shift between signals, we conclude that the electrostatic wave which converts into NTC is mainly governed by the plasma density, affected by movements of the magnetic field lines. Furthermore, we demonstrate that the observations can be used to perform a magnetoseismology of the emitting surface. The results show a steepening of the plasmapause density profile near the satellites, which can be responsible for the generation of NTC emission

High-Spatial-Resolution Monitoring of Strong Magnetic Field using Rb vapor Nanometric-Thin Cell

We have implemented the so-called $\lambda$-Zeeman technique (LZT) to investigate individual hyperfine transitions between Zeeman sublevels of the Rb atoms in a strong external magnetic field $B$ in the range of $2500 - 5000$ G (recently it was established that LZT is very convenient for the range of $10 - 2500$ G). Atoms are confined in a nanometric thin cell (NTC) with the thickness $L = \lambda$, where $\lambda$ is the resonant wavelength 794 nm for Rb $D_1$ line. Narrow velocity selective optical pumping (VSOP) resonances in the transmission spectrum of the NTC are split into several components in a magnetic field with the frequency positions and transition probabilities depending on the $B$-field. Possible applications are described, such as magnetometers with nanometric local spatial resolution and tunable atomic frequency references.Comment: 12 page

Peningkatan Proses Pembersihan Strip Pelapis Dari Manual ke Semi Otomatis

Memproduksi sensor NTC melewati proses electrostatic coating / pelapisan NTC menggunakan bubuk. Sebelum memasuki proses electrostatic coating, NTC diletakkan pada strip (besi berbahan stainless) dan direkatkan menggunakan isolasi agar NTC tidak terjatuh. Kemudian NTC akan melewati beberapa proses sampai dengan proses untapping. Proses untapping bertujuan melepaskan isolasi dari NTC. Saat isolasi dilepas dari NTC, lem bekas isolasi menempel pada strip. Untuk memulai kembali ke proses awal dibutuhkan strip yang bersih, sehingga manpower harus melakukan pembersihan strip secara manual. Oleh karena itu dilakukan sebuah inovasi dengan membuat mesin untuk mengubah proses pembersihan strip dari manual ke semi otomatis. Peneltian ini ditujukan pada proses brushing station untuk mendapatkan parameter yang bagus guna menghasilkan strip yang bersih. Menggunakan metode Design of Experiment untuk mendapatkan parameter yang menjadi ketetapan prosedur di brushing station. Dari hasil pengujian didapat nilai parameter pada penekanan brush 3.6 mm dengan kecepatan motor 5000 Rpm dapat menghasilkan strip yang bersih

Energy Efficient Network-on-Chip Architectures for Many-Core Near-Threshold Computing System

Near threshold computing has unraveled a promising design space for energy efficient computing. However, it is still plagued by sub-optimal system performance. Application characteristics and hardware non-idealities of conventional architectures (those optimized for nominal voltage) prevent us from fully leveraging the potential of NTC systems. Increasing the computational core count still forms the bedrock of a multitude of contemporary works that address the problem of performance degradation in NTC systems. However, these works do not categorically address the shortcomings of the conventional on-chip interconnect fabric in a many core environment. In this work, we quantitatively demonstrate the performance bottleneck created by a conventional NTC architecture in many-core NTC systems. To reclaim the performance lost due to a sub-optimal NoC in many-core NTC systems, we propose BoostNoC—a power efficient, multi-layered network-on-chip architecture. BoostNoC improves the system performance by nearly 2× over a conventional NTC system, while largely sustaining its energy benefits. Further, capitalizing on the application characteristics, we propose two BoostNoC derivative designs: (i) PG BoostNoC; and (ii) Drowsy BoostNoC; to improve the energy efficiency by 1.4× and 1.37×, respectively over conventional NTC system

A profile of anaesthesia trainees in Hong Kong

Objectives. To examine the demographics, professional background, progress, and aspirations of anaesthesia trainees in Hong Kong. Design. Anonymous questionnaire consisting of 56 items grouped into the areas of demographics, and anaesthetic and postanaesthetic training. Eight of the items were open questions. Descriptive analyses were undertaken for the closed items. Setting. Hong Kong College of Anaesthesiologists, Hong Kong. Participants. All trainees. Main outcome measures. Demographic data, aspects of training, supervision, working environment, career aspirations, job satisfaction, and morale. Results. The response rate was 77%. The various problems highlighted by respondents included the need for more input and feedback into individual training programmes, the lack of senior support, and the need for more relevant and examination-orientated courses and workshops. Unsatisfactory aspects of the specialty reported were the lack of control over work routines, relationships with surgeons, boredom, and the poor public image of the specialty. Eighty-four percent of respondents reported having reasonable to good job satisfaction. Conclusions. Ongoing benefits could be derived from enhancing communication between trainees and the Hong Kong College of Anaesthesiologists, through appropriate channels for trainee feedback.published_or_final_versio

Study of an Alternate Mechanism for the Origin of Fermion Generations

In usual extended technicolor (ETC) theories based on the group ${\rm{SU}(N_{ETC}})_{ETC}$, the quarks of charge 2/3 and -1/3 and the charged leptons of all generations arise from ETC fermion multiplets transforming according to the fundamental representation. Here we investigate a different idea for the origin of SM fermion generations, in which quarks and charged leptons of different generations arise from ETC fermions transforming according to different representations of ${\rm{SU}(N_{ETC}})_{ETC}$. Although this mechanism would have the potential, {\it a priori}, to allow a reduction in the value of $N_{ETC}$ relative to conventional ETC models, we show that, at least in simple models, it is excluded by the fact that the technicolor sector is not asymptotically free or by the appearance of fermions with exotic quantum numbers which are not observed.Comment: 6 pages, late

Technipion Limits from LHC Higgs Searches

LHC searches for the standard model Higgs Boson in di-photon or di-tau decay modes place strong constraints on the light top-pion state predicted in technicolor models that include colored technifermions. Compared with the standard Higgs Boson, the top-pions have an enhanced production rate (largely because the technipion decay constant is smaller than the weak scale) and also enhanced branching ratios into di-photon and di-tau final states (largely due to the suppression of WW decays of the technipions). These factors combine to make the technipions more visible in both channels than a standard model Higgs would be. Hence, the recent ATLAS and CMS searches for Higgs bosons exclude the presence of technipions with masses from 110 GeV to nearly twice the top-quark mass in technicolor models that (a) include colored technifermions (b) feature topcolor dynamics and (c) have technicolor groups with three or more technicolors. For certain models, the limits also apply out to higher technipion masses or down to the minimum number of technicolors. The limits may be softened somewhat in models where extended technicolor plays a significant role in producing the top quark's mass. Additional LHC data on di-tau and di-photon final states will be extremely valuable in further exploring technicolor parameter space.Comment: 15 pages, 5 figures, PDF-LaTe