Miracle-dz/UniFAR-FTUs huggingface dataset:
Neutral beam heating in the START spherical tokamak

The tight aspect ratios (typically A≈1.4) and low magnetic field of spherical tokamak (ST) plasmas, when combined with densities approaching the Greenwald limit, provide a significant challenge for all currently available auxiliary heating and current drive schemes. NBI heating and current drive are difficult to interpret in sub-megampere machines, as in order to achieve suitable penetration into the plasma core, fast ions have to be highly suprathermal and, as a result of the low magnetic field, can be non-adiabatic (i.e. non-conserving of magnetic moment µ0). The physics of NBI heating in START is discussed. The neutral beam injector deployed on START was clearly successful, having been instrumental in producing a world record tokamak toroidal beta of ≈40%. A fast ion Monte Carlo code (LOCUST) is described that was developed to model non-adiabatic fast ion topologies together with a high level of charge exchange loss and cross-field transport (present in START due to an envelope of high density gas surrounding the plasma). Model predictions compare well with experimental data, collected using a scanning neutral particle analyser, bolometric instruments and equilibrium reconstruction using EFIT. In particular, beta calculations based upon reconstruction of the pressure profile (by combining measurements from Thomson scattering, charge exchange recombination spectroscopy and model predictions for the fast ion distribution function) agree well with beta values calculated using EFIT alone (the routine method for calculation of START beta). These results thus provide increased confidence in the ability of STs to sustain high beta high confinement H mode plasmas and in addition indicate that the injected fast ions in collisional START plasmas evolve mainly due to collisional and charge exchange processes, without driving any significant performance degrading fast particle MHD activity.
Slepian-Wolf Coding of Three Binary Sources Using LDPC Codes

A distributed source coding system of three sources is considered. We show how low-density parity-check (LDPC) codes can be used in SlepianWolf coding of three equiprobable, memoryless and correlated binary sources with rates close to the theoretical limit. Applying the syndrome concept, we can treat Slepian-Wolf coding of binary sources as a channel coding problem. LDPC codes are suitable for such an application because the correlation model can be used in the LDPC code design. An LDPC code is designed with performance very close to the Slepian-Wolf limit for three sources.
Measurement and verification of concentration-dependent diffusion coefficient: Ray tracing imagery of diffusion process

Ray tracing method is used to study the propagation of collimated beams in a liquid–core cylindrical lens (LCL), which has dual functions of diffusion cell and image formation. The diffusion images on the focal plane of the used LCL are simulated by establishing and solving both linear and nonlinear ray equations, the calculated results indicate that the complex imaging results of LCL in inhomogeneous media can be treated by the law of ray propagation in homogeneous media under the condition of small refractive index gradient of diffusion solution. Guided by the calculation conditions, the diffusion process of triethylene glycol aqueous solution is experimentally studied at room temperature by using the LCL in this paper. The spatial and temporal concentration profile Ce(z, t) of diffusion solution is obtained by analyzing diffusion image appearing on the focal plane of the LCL; Then, the concentration-dependent diffusion coefficient is assumed to be a polynomial D(C) = D0 × (1 + α1C + α2C2 + α3C3 + ⋅). The finite difference method is used to solve the Fick diffusion equation for calculating numerically the concentration profiles Cn(z, t). The D(C)of triethylene glycol aqueous solution is obtained by comparing the Cn(z, t) with Ce(z,t). Finally, the obtained polynomial D(C) is used to calculate the refractive index profiles nn(z,t)s of diffusion solution in the used LCL. Based on the ray propagation law in inhomogeneous media and the calculated n(z,t), the ray tracing method is used again to simulate the dynamic images of the whole experimental diffusion process to varify the correctness of the calculated D(C). The method presented in this work opens up a new way for both measuring and verifying the concentration-dependent liquid diffusion coefficients.
Forward dispersion relations and low-energy theorems for Compton scattering on spin-1 targets

The differential cross section in the laboratory system for Compton scattering on polarized and unpolarized spin-1 targets is derived up to the second and third order in photon energy respectively. The results are expressed in terms of charge, magnetic dipole moment, electric quadrupole moment, and four structure-dependent constants. The forward dispersion relations and low-energy theorems are combined to obtain two sum rules for these structure-dependent constants. The effects of C, P and T non-invariances are discussed.
Transmission through array of subwavelength metallic slits curved with a single step or multi-step

The transmission of normally incident plane wave through an array of subwavelength metallic slits curved with a single step or mutli-step has been explored theoretically. The transmission spectrum is simulated by using the finite-difference time-domain method. The influences of surface plasmon polaritons make the end of finite long sub-wavelength metallic slit behaves as magnetic-reflecting barrier. The electromagnetic fields in the subwavelength metallic slits are the superposition of standing wave and traveling wave. The standing electromagnetic oscillation behaves like LC oscillating circuit to decide the resonance wavelength. Therefore, the parameters of adding step may change the LC circuit and influence the transmission wavelength. A new explanation model is proposed in which the resonant wavelength is decided by four factors: the changed length for electric field, the changed length for magnetic field, the effective coefficient of capacitance, and the effective coefficient of inductance. The effect of adding step is presented to analyze the interaction of two steps in slit with mutli-step. This explanation model has been proved by the transmission through arrayed subwavelength metallic slits curved with two steps and fractal steps. All calculated results are well explained by our proposed model.
The geometric transfer function component for scintillation camera collimators with straight parallel holes

A theoretical approach has been developed that allows the geometric transfer function component for conventional scintillation camera collimators to be predicted in closed form. If transfer function analysis is to be useful in describing imaging system performance, the image of a point source must not depend on source position in a plane parallel to the detection plane. This shift invariance can be achieved by analysis of system response in terms of an effective point spread function, defined as the normalised image of a point source that would be obtained if the camera collimator were uniformly translated (but not rotated) during image formation. The geometric component of the corresponding effective transfer function is shown to be expressed simply by the absolute square of the two-dimensional Fourier transform of a collimator hole aperture, with the spatial frequency plane scaled by a factor which depends on collimator length, source-to-collimator distance, and collimator-to-detection plane distance. Closed form algebraic expression of the geometric transfer function have been obtained for all four common hole shapes (circular, hexagonal, square and triangular). Monte Carlo simulations and experimental measurements have shown these theoretical expressions to be highly accurate.
Reverse hierarchical PIV processing

A novel hierarchical processing scheme is proposed to efficiently increase the spatial resolution and dynamic range of detecting particle image displacements in PIV images. The technique takes full advantage of the multi-resolution characteristic of the discrete correlation function by starting the processing at the smallest scale and, if necessary, gradually building correlation planes into larger interrogation areas based on the result of inter-level correlation correction and validation. It is shown that the algorithm can be implemented in both direct and FFT based correlation algorithms with greatly reduced computational complexity. The technique opens new perspectives for locally adaptive super-resolution processing taking flow field, seeding, and imaging anomalies into account. Processing at the lowest scale (e.g. pixel or particle image size) allows the combination of correlation planes on any shape. Hence the proposed reverse hierarchical processing represents interrogation area optimization both in size and shape in order to maximize the correlation plane signal-to-noise ratio. The method is successfully demonstrated on experimentally obtained images.
Impact of the local void on the cosmological parameters

In this paper, I discuss the effects of a local void on the cosmological parameters. It is found that, if the supernova distance is absolutely calibrated, then the bias of all the cosmological parameters is always important, while if the supernova distance is relatively calibrated, the largest effects will appear in the dark energy equation of state. For a local void of size ∼ 100 Mpc, the bias effects mainly manifest in the low redshift range. Therefore, the piecewise dark energy equation of state, especially the one in the range of lowest redshift, will be more strongly affected than the constant equation of state. In order to reduce this bias in constraining the cosmological parameters, one could require the distance of all the adopted supernovas be greater than 1.2 ∼ 1.5 times of the radius of the local void. In this case, the residual bias can be safely ignored.
CA II TRIPLET SPECTROSCOPY OF SMALL MAGELLANIC CLOUD RED GIANTS. III. ABUNDANCES AND VELOCITIES FOR A SAMPLE OF 14 CLUSTERS

We obtained spectra of red giants in 15 Small Magellanic Cloud (SMC) clusters in the region of the Ca ii lines with FORS2 on the Very Large Telescope. We determined the mean metallicity and radial velocity with mean errors of 0.05 dex and 2.6 km s−1, respectively, from a mean of 6.5 members per cluster. One cluster (B113) was too young for a reliable metallicity determination and was excluded from the sample. We combined the sample studied here with 15 clusters previously studied by us using the same technique, and with 7 clusters whose metallicities determined by other authors are on a scale similar to ours. This compilation of 36 clusters is the largest SMC cluster sample currently available with accurate and homogeneously determined metallicities. We found a high probability that the metallicity distribution is bimodal, with potential peaks at −1.1 and −0.8 dex. Our data show no strong evidence of a metallicity gradient in the SMC clusters, somewhat at odds with recent evidence from Ca ii triplet spectra of a large sample of field stars. This may be revealing possible differences in the chemical history of clusters and field stars. Our clusters show a significant dispersion of metallicities, whatever age is considered, which could be reflecting the lack of a unique age–metallicity relation in this galaxy. None of the chemical evolution models currently available in the literature satisfactorily represents the global chemical enrichment processes of SMC clusters.
Antiferromagnetism

The ground state of a lattice with one electron per atom and antiferromagnetic interactions between nearest neighbours only is examined by a variational method similar in principle to the treatments by Hulthén (1938) and Kasteleijn (1952) of the linear-chain problem. The calculation involves a statistical problem which is shown to be exactly equivalent to the Ising ferromagnetic problem. This cannot be solved exactly, except in the one-dimensional case, and so the Bethe–Peierls method is used to solve it approximately. In complete contradiction to the Kubo (1953) variational calculation it is concluded that all lattices have disordered ground states. The energy differences between ordered and disordered states are small and so the nature of the ground state is likely to be sensitive to small additional ordering forces.
The amino terminal and E2F interaction domains are critical for C/EBPα-mediated induction of granulopoietic development of hematopoietic cells Running Head: C/EBPα mediated granulopoietic development Scientific Section Heading: Hematopoiesis

The transcription factor C/EBPα is critical for granulopoiesis. Gene disruption in mice blocks early granulocyte differentiation, and disruption of C/EBPα function has been implicated in human Acute Myelogenous Leukemia (AML), but no systematic structure-function analysis has been undertaken to identify the mechanisms involved in C/EBPα mediated granulocyte differentiation. Here we demonstrate that loss of either of two key regions result in disruption of C/EBPα granulocytic development: the amino terminus, and specific residues residing on the non-DNA binding face of the basic region. Mutation of either results in loss of C/EBPα inhibition of E2F and down-regulation c-Myc, but only mutation of the basic region results in loss of physical interaction with E2F. In contrast, while the amino terminal mutant retains the ability to interact with E2F, this mutant fails to bind a C/EBPα site efficiently, activate C/EBPα target genes, and is also defective in inhibition of E2F activity. These results further emphasize the importance of inhibition of proliferative pathways in granulopoiesis, and demonstrate that several regions of the C/EBPα protein are involved in this mechanism. dtenen@bidmc.harvard. edu For personal use only. by guest on June 2, 2013. bloodjournal.hematologylibrary. org From
Thomson scattering on a low-pressure, inductively-coupled gas discharge lamp

Excitation and light production processes in gas discharge lamps are the result of inelastic collisions between atoms and free electrons in the plasma. Therefore, knowledge of the electron density ne and temperature Te is essential for a proper understanding of such plasmas. In this paper, an experimental system for laser Thomson scattering on a low-pressure, inductively-coupled gas discharge lamp and measurements of ne and Te in this lamp are presented. The experimental system is suitable for low electron temperatures (down to below 0.2 eV) and employs a triple grating spectrograph for a high stray light rejection, or equivalently a low stray light redistribution (Reff≈7×10-9 nm-1 at 0.5 nm from the laser wavelength). The electron density detection limit of the system is ne≈1016 m-3. The modifications to the lamp that were necessary for the measurements are described, and results are presented and compared to previous work and trends expected from the electron particle and energy balances. The electron density and temperature are about ne≈1019 m-3 and Te≈1 eV in the most active part of the plasma; the exact values depend on the argon filling pressure, the mercury pressure and the position in the lamp.
Chemical kinetics of NO removal by pulsed corona discharges

Nitric oxides (NO and NO2) and SO2 emissions are a major environmental problem because of their negative influence on human health and vegetation. The federal regulations on limiting the pollution emitted by the engines of motor vehicles have triggered intense research on new techniques for the removal of these pollutants. New methods for exhaust gas cleaning are needed and among the several approaches to reduce the pollutant emissions, the non-thermal plasma technique shows promise (Luo J, Suib S L, Marques M, Hayashi Y and Matsumoto H 1998 J. Phys. Chem. A 102 7954). In this work, a volume-averaged model is presented that can describe the removal of NOx by the multi-pulse treatment of the exhaust gases at low temperatures and at atmospheric pressure in corona reactors. The model takes into account the production of active radicals after every discharge and the removal of NO by these radicals. Furthermore, the effect of ethene, one of the most important unburnt hydrocarbons in the exhaust gas, on the removal of NO is also investigated in this study. The effect of ethene has been investigated experimentally by several authors (Mizuno A, Chakrabati A and Okazaki K 1993 Non-Thermal Plasma Techniques for Pollution Control ed B M Penetrante and S E Schultheis (Berlin: Springer) p 165, Prather M J and Logan J A 1994 Proc. Combustion Institute 25 1513), but there are almost no studies which try to explain, in detail, the chemical processes in such a system. The detailed reaction mechanism used in this study consists of 443 elementary reactions and 50 chemical species. The results of our numerical simulations show good agreement with the experimental results published in the literature. Reaction flow analysis and sensitivity analysis are performed in order to identify the specific reaction paths and the rate-limiting reactions for typical operating conditions of pulsed corona reactors.
Vibration suppression and zero reaction maneuvers of flexible space structure mounted manipulators

This paper deals with vibration suppression control of a flexible space structure comprising a robotic manipulator arm. When the manipulator arm is operated without any special attention, the reaction of the arm may excite vibrations in the base structure. However, when the arm is operated under a control technique called `reaction null space' the manipulator dynamics is totally decoupled from the base dynamics. Thus, no vibrations are induced into the flexible structure. Such manipulator operations are called `zero reaction maneuvers'. On the other hand, the orthogonal complement of the reaction null space can be used to achieve maximum coupling with the base, in order to effectively damp the vibration energy in the structure out into the manipulator arm. Such operations are useful for vibration suppression control. The paper develops control laws for vibration suppression and zero reaction maneuvers using the reaction null-space concept, and examines the effectiveness of the control laws by experiments with a planar flexible base system.
Analyzing cosmic bubble collisions

We develop a set of controlled, analytic approximations to study the effects of bubble collisions on cosmology. We expand the initial perturbation to the inflaton field caused by the collision in a general power series, and determine its time evolution during inflation in terms of the coefficients in the expansion. In models where the observer's bubble undergoes sufficient slow-roll inflation to solve the flatness problem, in the thin wall limit only one coefficient in the expansion is relevant to observational cosmology, allowing nearly model-independent predictions. We discuss two approaches to determining the initial perturbation to the inflaton and the implications for the sign of the effect (a hot or cold spot on the Cosmic Microwave Background temperature map). Lastly, we analyze the effects of collisions with thick-wall bubbles, i.e. away from the thin-wall limit.
Predictors of the Intensity of Symptoms in a Cluster in Patients With Breast Cancer

Purpose: To examine the influence of selected demographic and clinical variables on the intensity of symptoms in two previously identified symptom clusters (psychoneurological and upper gastrointestinal) across the treatment trajectory for breast cancer. Design: A secondary analysis was conducted with a sample of 282 female breast-cancer patients who were receiving chemotherapy or radiation therapy in two American cancer centers. Data were collected three times across the treatment trajectory: baseline (before chemotherapy or radiation treatment) and two follow-up times after treatment initiation. Method: Multiple regression analyses were done at each time point to examine the influence of selected demographic and clinical variables on the intensity of symptoms in each cluster. Findings: Baseline physical performance status was a consistent predictor of symptom intensity in the psychoneurological cluster across time whereas age and treatment modality were consistent predictors of symptom intensity in the upper gastrointestinal cluster. Poor physical performance at baseline predicted more intense psychoneurological symptoms. Younger women and women undergoing chemotherapy experienced more intense gastrointestinal symptoms. In addition, at the second follow-up treatment modality also influenced intensity of symptoms in the psychoneurological cluster and race and baseline physical performance status also influenced the intensity of symptoms in the upper gastrointestinal cluster. Conclusions: Clinicians can anticipate that younger patients, patients with poor baseline physical performance status, and patients who receive chemotherapy will have more intense treatment-related gastrointestinal and psychoneurological symptoms during adjuvant breast cancer therapy. Further research is needed to determine whether collective management for symptoms in a cluster may be beneficial. Clinical Relevance: Clinicians can use findings from the present study to identify patients who need greater attention to symptom assessment and management, including anticipatory counseling of patients and families.
In search for key biogeochemical factors affecting plant species persistence in heathland and acidic grasslands: a comparison of common and rare species

1. During the last century, many plant species typical of heathland and nutrient-poor acidic grasslands have become rare whereas others have remained common. Habitat restoration often fails to enhance the rare species, which may in part be caused by the failure to restore the biogeochemical conditions suited to these species. Many soil variables have been shown to affect plant fitness but it is unknown what their relative importance is and whether any biogeochemical variable acts as a key factor constraining the persistence of rare heathland species. 2. We compiled a data set consisting of 300 vegetation samples and the associated soil chemical properties from a range of studies carried out across the Netherlands. We asked whether growth sites of rare and common species typical of heathland and acidic grasslands differed in their biogeochemical properties, and whether growth sites of rare species displayed less variation in soil biogeochemical variables (e.g. had narrower ecological amplitude). 3. Regardless of rarity, the species' growth sites were most accurately described by a curvilinear relationship between pH and Al/Ca ratios. Other soil characteristics did not vary systematically with changing acidity of the soil or the patterns were less pronounced. Acidification will therefore most rapidly and predictably result in an increase in Al/Ca ratio whereas this is not necessarily the case for the other soil variables affecting plant fitness. 4. The soil ammonium (NH4) concentration and ammonium/nitrate (NH4/NO3) ratio were 3.5 and 3 times higher, respectively, in growth sites of common species compared with those of rare species. No other measured variable differed significantly between rare and common plant species. 5. On average rare species had a significantly narrower ecological amplitude than common species for soil biogeochemical parameters. 6. Synthesis and applications. A greater sensitivity to high NH4 concentrations in combination with a narrower ecological tolerance zone for a range of soil biogeochemical factors may explain the demise of rare species adapted to nutrient-poor acidic habitats in recent decades. Conservation management should aim to restore low NH4 concentrations and NH4/NO3 ratios. Experimental studies indicate that the most effective way to do this is through removal of the topsoil in combination with liming.