Impact of AQUA Satellite Data on Hurricane Forecast: Danielle 2010

This study focuses on the impact of AQUA satellite data from AIRS and AMSU on the forecast of hurricane Danielle by the Global Forecast System (GFS) model. The data assimilation method adopted to ingest the data is the Gridpoint Statistical method (GSI) which is based on the three dimensional variational (3DVAR) data assimilation technique. Two experiments were carried out to investigate the impact of AQUA satellite radiance observation on the forecast of hurricane Danielle. The first experiment (Control) assimilated all the available data while the second experiment (No AQUA) incorporated all the observations but the AQUA satellite data. Data assimilation cycling started one week prior to hurricane genesis, on 15 August 2010 06 UTC. The root mean square track forecast error shows slightly negative impact at the early lead time and slightly positive impact at later lead time. However, the root mean square intensity forecast errors by the Control are shown to be lower than No AQUA for all forecast hours, indicating positive impact of the AQUA data on the intensity forecast

Fusion of anthropometric data and principal component analysis of the bones for generating a personalized skeleton: case of the lower limb

5th International Digital Human Modeling Symposium, BONN, ALLEMAGNE, 26-/06/2017 - 28/06/2017An approach is presented and evaluated here to provide realistic internal and external dimensions of Human Body Models for a broad range of predictor values, such as, for example, to estimate the dimensions of a slightly overweight 11 year old of height 1m40. The difficulty due to lack of sufficient internal and external data is alleviated by combining widely available anthropometric measurements with more sparse databases of surface meshes of bones. Assuming that the external anthropometric measurements are estimated from the predictors through a regression, the link with the internal shape dimensions is made through the subset of target ?skeletal? measurements that can be closely estimated from skeletal landmarks. The matching of internal dimensions then proceeds as follows. First the set of surface meshes of bones is aligned and a Principal Component Analysis (PCA) model of their variance compared to their mean shape is evaluated. This is done by aligning the bones, body part by body part, in such a way that the effect of posture is removed, and by evaluating the variance for the whole skeleton, so that the covariance of shapes between different bones is captured. Any subject sampled from this PCA model consists in a set of bones loosely positioned compared to each other, for particular values of the Principal Component (PC) modal magnitudes or scores. In a second step, values of these modal magnitudes are estimated in such a way that the corresponding sampled subject skeleton has dimensions that estimate closely the target skeletal anthropometric measurements. In this last step, a direct kinematic approach and a sequential quadratic programming method are used to reposition the sampled bones in an appropriate posture and to evaluate the most appropriate PC scores. The whole approach is successfully applied and evaluated on a three segment model of the lower limb

One-step hydrothermal synthesis of fluorescence carbon quantum dots with high product yield and quantum yield

A one-step hydrothermal synthesis of nitrogen and silicon co-doped fluorescence carbon quantum dots (N,Si-CQDs), from citric acid monohydrate and silane coupling agent KH-792 with a high product yield (PY) of 52.56% and high quantum yield (QY) of 97.32%, was developed. This greatly improves both the PY and QY of CQDs and provides a new approach for a large-scale production of high-quality CQDs. Furthermore, N,Si-CQDs were employed as phosphors without dispersants to fabricate white light-emitting diodes (WLEDs) with the color coordinates at (0.29, 0.32). It is suggested that N,Si-CQDs have great potential as promising fluorescent materials to be applied in WLEDs.Peer reviewe

The observation of diffraction phases in matter wave scattering

We study the diffraction phase of different orders via the Dyson expansion series, for ultracold atomic gases scattered by a standing-wave pulse. As these diffraction phases are not observable in a single pulse scattering process, a temporal Talbot-Lau interferometer consisting of two standing-wave pulses is demonstrated experimentally with a Bose-Einstein condensate to explore this physical effect. The role of the diffraction phases is clearly shown by the second standing-wave pulse in the relative population of different momentum states. Our experiments demonstrate obvious effects beyond the Raman-Nath method, while agree well with our theory by including the diffraction phases. In particular, the observed asymmetry in the dependence of the relative population on the interval between two standing-wave pulses reflects the diffraction phase differences. The role of interatomic interaction in the Talbot-Lau interferometer is also discussed.Comment: 7 pages, 3 figures, accepted by Phys. Rev.

Finite element models of the thigh-buttock complex for assessing static sitting discomfort and pressure sore risk

Being seated for long periods, while part of many leisure or occupational activities, can lead to discomfort, pain and sometimes health issues. The impact of prolonged sitting on the body has been widely studied in the literature, with a large number of human-body finite element models developed to simulate sitting and assess seat-induced discomfort or to investigate the biomechanical factors involved. Here, we review the finite element models developed to investigate sitting discomfort or risk of pressure sores. Our study examines finite element models from twenty-seven papers, seventeen dedicated to assessing seating discomfort and ten dedicated to investigating pressure ulcers caused by prolonged sitting. The models' mesh composition and material properties are found to differ widely. These models share a lack of validation and generally make little allowance for anthropometric diversity

A parametric model of the thigh-buttock complex for developing FE model to estimate seat pressure

5th International Digital Human Modeling Symposium, BONN, ALLEMAGNE, 26-/06/2017 - 28/06/2017Contact pressure on the seat surface is one of the most important factors to consider when assessing sitting discomfort (De Looze et al., 2003). Several finite element models of the thigh-buttock region have been developed to simulate user-seat interaction. However, the models predominantly match one specific body anthropometric type (often the 50th male per-centile in stature), meaning they cannot represent the large range of variation of sitters' population. The objective of this study was to develop a parametric model of the thigh-buttock region including both bones (pelvis and femur) and outer skin of varying ranges of anthropometry. Thirty-six participants (19 males, 17 females) of varying weight (healthy BMI, obese BMI) and stature (small, average height and tall) were recruited for this study. Using a VICON optoelectronic system, 8 pelvis anatomical landmarks were palpated manually in a seated position. Participants were then scanned using a portable handheld laser scanner (Nikon, ModelMaker MMD x /MMC Handheld Scanner) in a position with a thigh-trunk angle of approximately 110°. The position was maintained by an adjustable kneeling structure so that both the torso and the thighs were not supported, making it more accessible to scan the back, buttocks and thighs. After having pre-processed the 3D scans, a principal component analysis was first performed on the coordinates of the surface mesh including anatomical landmarks. Then, a statistical linear regression was run on the retained PC scores with stature, BMI and pelvis-femur angle as predictors in order to obtain a statistical shape model (SSM). Regarding bone surfaces, the SSMs of femur and pelvis were obtained using previously collected CT scans of 54 bodies from the University Libre de Bruxelles, Belgium. The bony landmarks predicted by the SSM of external shape were used as the inputs of the SSM of bones surface. Bone surface estimation was assessed with the use of MRI images of one subject. The parametric model of thigh-buttock complex will be used to generate the meshes of the finite element models to be developed for simulating occupant/seat interaction for a large range of anthropometry

Semivolatile behaviour and filter sampling artifacts for dicarboxylic acids during summer campaigns at three forested sites in Europe

The sampling artifacts for C(2)-C(5) dicarboxylic acids (DCAs) were studied by collecting high-volume PM(2.5) samples using front and back quartz-fibre filters. The filters were analysed for carbonaceous components, and for inorganic cationic and anionic and organic anionic species. Back/front filter ratios were determined for the C(2)-C(5) DCAs, but also for methanesulphonate (MSA(-)), the various inorganic species, and the carbonaceous components. The sampling artifacts for the inorganic species were small (< 5%) with the exception of those for nitrate. The median back/front filter ratios for MSA(-) and the C(2)-C(5)DCAs increased in the following order: oxalate (1.5%)-succinate (3%)-MSA(-) (4%)-malonate (2%-9%)-glutarate (7%-26%). Most of these ratios are smaller than those that were obtained for organic carbon, total carbon, and especially water-soluble organic carbon. Our back/front ratios for the C(2)-C(5) DCAs are lower to much lower than those found in other studies

Manipulating the momentum state of a condensate by sequences of standing wave pulses

We analyze the effects of sequences of standing wave pulses on a Bose-Einstein condensate (BEC). Experimental observations are in good agreement with a numerical simulation based on the band structure theory in the optical lattice. We also demonstrate that a coherent control method based on such sequences of pulses is very efficient for experimentally designing specific momentum states.Comment: 6 pages; 5 figures; submitted to PR

Neutrino Emission From Direct Urca Processes in Pion Condensed Quark Matter

We study neutrino emission from direct Urca processes in pion condensed quark matter. In compact stars with high baryon density, the emission is dominated by the gapless modes of the pion condensation which leads to an enhanced emissivity. While for massless quarks the enhancement is not remarkable, the emissivity is significantly larger and the cooling of the condensed matter is considerably faster than that in normal quark matter when the mass difference between $u$- and $d$-quarks is sizable.Comment: 12 pages,6 figures, published versio