35,530 research outputs found
Polyols in confectionery: the route to sugar-free, reduced sugar and reduced calorie confectionery
Polyol-containing confectionery offers considerable advantages over traditional sucrose-based confectionery in terms of reduced energy content and reduced cariogenicity. However, over-consumption of polyol confectionery may lead to gastrointestinal symptoms in some individuals. Rather than consider this as a distinct disadvantage to the consumer, this article discusses how careful consideration of the physico-chemical properties of polyols and advances in product development and formulation can provide suitable polyol-based products for the consumer. Furthermore. food legislation and ingredient pricing issues are just some of the factors that must be taken into account when designing new polyol-containing products if their functional benefits and good product quality are to be delivered to the consumer
Kinematically Redundant Octahedral Motion Platform for Virtual Reality Simulations
We propose a novel design of a parallel manipulator of Stewart Gough type for
virtual reality application of single individuals; i.e. an omni-directional
treadmill is mounted on the motion platform in order to improve VR immersion by
giving feedback to the human body. For this purpose we modify the well-known
octahedral manipulator in a way that it has one degree of kinematical
redundancy; namely an equiform reconfigurability of the base. The instantaneous
kinematics and singularities of this mechanism are studied, where especially
"unavoidable singularities" are characterized. These are poses of the motion
platform, which can only be realized by singular configurations of the
mechanism despite its kinematic redundancy.Comment: 13 pages, 6 figure
Unhealthy weight control behaviours in adolescent girls: a process model based on self-determination theory
This study used self-determination theory (Deci, E.L., & Ryan, R.M. (2000). The 'what' and 'why' of goal pursuits: Human needs and the self-determination of behavior. Psychological Inquiry, 11, 227-268.) to examine predictors of body image concerns and unhealthy weight control behaviours in a sample of 350 Greek adolescent girls. A process model was tested which proposed that perceptions of parental autonomy support and two life goals (health and image) would predict adolescents' degree of satisfaction of their basic psychological needs. In turn, psychological need satisfaction was hypothesised to negatively predict body image concerns (i.e. drive for thinness and body dissatisfaction) and, indirectly, unhealthy weight control behaviours. The predictions of the model were largely supported indicating that parental autonomy support and adaptive life goals can indirectly impact upon the extent to which female adolescents engage in unhealthy weight control behaviours via facilitating the latter's psychological need satisfaction
YouTube as a source of information for patients considering surgery for ulcerative colitis
© 2017 Elsevier Inc. Background With the range of health information online, assessing the resources that patients access may improve the content of preoperative information. Our aim was to assess the content of the most viewed videos on YouTube related to surgery for ulcerative colitis (UC). Methods YouTube was searched for videos containing information on surgery for UC. The 50 most viewed videos were identified and user interaction analyzed. Upload source was classified as patient, individual health care professional (HCP), or hospital/professional association. Video content was categorized using an inductive thematic analysis on a purposive sample list of videos. The overarching theme of each video was classified once data saturation was achieved. Results Thirty videos were uploaded by patients, 15 by hospitals and 5 by HCPs. Seventeen videos (34%) discussed life after surgery. Sixteen of these were uploaded by patients who had previously undergone surgery for UC. No videos of this theme were uploaded by HCPs. Ten videos (20%) described a number of different operations. Other themes identified were alternative health therapies (12%), colonoscopy (12%), life with UC (8%), miscellaneous (8%), and education for HCPs (6%). Patient uploaded videos had significantly more comments (P = 0.0079), with 28% of comments on patient videos being users requesting further information. Conclusions Understanding the sequelae of surgery is most important to preoperative patients. There are a lack of professional videos addressing this topic on YouTube. HCPs must participate in the production of videos and adapt preoperative consultations to address common preoperative concerns
Finite Element Modelling for the Investigation of Edge Effect in Acoustic Micro Imaging of Microelectronic Packages
In acoustic micro imaging of microelectronic packages, edge effect is often presented as artifacts of C-scan images, which may potentially obscure the detection of defects such as cracks and voids in the solder joints. The cause of edge effect is debatable. In this paper, a two-dimensional finite element model is developed on the basis of acoustic micro imaging of a flip-chip package using a 230 MHz focused transducer to investigate acoustic propagation inside the package in attempt to elucidate the fundamental mechanism that causes the edge effect. A virtual transducer is designed in the finite element model to reduce the coupling fluid domain, and its performance is characterised against the physical transducer specification. The numerical results showed that the Under Bump Metallization (UBM) structure inside the package has a significant impact on the edge effect. Simulated wavefields also showed that the edge effect is mainly attributed to the horizontal scatter, which is observed in the interface of silicon die-to-the outer radius of solder bump. The horizontal scatter occurs even for a flip-chip package without the UBM structure
Enhanced efficiency of solid-state NMR investigations of energy materials using an external automatic tuning/matching (eATM) robot.
We have developed and explored an external automatic tuning/matching (eATM) robot that can be attached to commercial and/or home-built magic angle spinning (MAS) or static nuclear magnetic resonance (NMR) probeheads. Complete synchronization and automation with Bruker and Tecmag spectrometers is ensured via transistor-transistor-logic (TTL) signals. The eATM robot enables an automated "on-the-fly" re-calibration of the radio frequency (rf) carrier frequency, which is beneficial whenever tuning/matching of the resonance circuit is required, e.g. variable temperature (VT) NMR, spin-echo mapping (variable offset cumulative spectroscopy, VOCS) and/or in situ NMR experiments of batteries. This allows a significant increase in efficiency for NMR experiments outside regular working hours (e.g. overnight) and, furthermore, enables measurements of quadrupolar nuclei which would not be possible in reasonable timeframes due to excessively large spectral widths. Additionally, different tuning/matching capacitor (and/or coil) settings for desired frequencies (e.g. Li and P at 117 and 122MHz, respectively, at 7.05 T) can be saved and made directly accessible before automatic tuning/matching, thus enabling automated measurements of multiple nuclei for one sample with no manual adjustment required by the user. We have applied this new eATM approach in static and MAS spin-echo mapping NMR experiments in different magnetic fields on four energy storage materials, namely: (1) paramagnetic Li and P MAS NMR (without manual recalibration) of the Li-ion battery cathode material LiFePO; (2) paramagnetic O VT-NMR of the solid oxide fuel cell cathode material LaNiO; (3) broadband Nb static NMR of the Li-ion battery material BNbO; and (4) broadband static I NMR of a potential Li-air battery product LiIO. In each case, insight into local atomic structure and dynamics arises primarily from the highly broadened (1-25MHz) NMR lineshapes that the eATM robot is uniquely suited to collect. These new developments in automation of NMR experiments are likely to advance the application of in and ex situ NMR investigations to an ever-increasing range of energy storage materials and systems.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 655444 (O.P.). D.M.H. acknowledges funding from the Cambridge Commonwealth Trusts. J.L. gratefully acknowledges Trinity College, Cambridge (UK) for funding. K.J.G. gratefully acknowledges funding from the Winston Churchill Foundation of the United States and the Herchel Smith Scholarship. M.B. is the CEO of NMR Service GmbH (Erfurt, Germany), which manufactures the eATM device; M.B. acknowledges funding of the Central Innovation Programme for small and medium-sized enterprises (SMEs; Zentrales Innovationsprogramm Mittelstand, ZIM) of the German Federal Ministry of Economic Affairs and Energy (Bundesministerium für Wirtschaft und Energie, BMWi) under the Grant No. KF 2845501UWF. DFT calculations were performed on (1) the Darwin Supercomputer of the University of Cambridge High Performance Computing Service (http://www.hpc.cam.ac.uk), provided by Dell Inc. using Strategic Research Infrastructure Funding from the Higher Education Funding Council for England and funding from the Science and Technology Facilities Council and (2) the Center for Functional Nanomaterials cluster, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-AC02-98CH10886
Correlators of Vertex Operators for Circular Strings with Winding Numbers in AdS5xS5
We compute semiclassically the two-point correlator of the marginal vertex
operators describing the rigid circular spinning string state with one large
spin and one windining number in AdS_5 and three large spins and three winding
numbers in S^5. The marginality condition and the conformal invariant
expression for the two-point correlator obtained by using an appropriate vertex
operator are shown to be associated with the diagonal and off-diagonal Virasoro
constraints respectively. We evaluate semiclassically the three-point
correlator of two heavy circular string vertex operators and one zero-momentum
dilaton vertex operator and discuss its relation with the derivative of the
dimension of the heavy circular string state with respect to the string
tension.Comment: 16 pages, LaTeX, no figure
Seeing Tree Structure from Vibration
Humans recognize object structure from both their appearance and motion;
often, motion helps to resolve ambiguities in object structure that arise when
we observe object appearance only. There are particular scenarios, however,
where neither appearance nor spatial-temporal motion signals are informative:
occluding twigs may look connected and have almost identical movements, though
they belong to different, possibly disconnected branches. We propose to tackle
this problem through spectrum analysis of motion signals, because vibrations of
disconnected branches, though visually similar, often have distinctive natural
frequencies. We propose a novel formulation of tree structure based on a
physics-based link model, and validate its effectiveness by theoretical
analysis, numerical simulation, and empirical experiments. With this
formulation, we use nonparametric Bayesian inference to reconstruct tree
structure from both spectral vibration signals and appearance cues. Our model
performs well in recognizing hierarchical tree structure from real-world videos
of trees and vessels.Comment: ECCV 2018. The first two authors contributed equally to this work.
Project page: http://tree.csail.mit.edu
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