4,557 research outputs found
Model for the free-volume distributions of equilibrium fluids
We introduce and test via molecular simulation a simple model for predicting
the manner in which interparticle interactions and thermodynamic conditions
impact the single-particle free-volume distributions of equilibrium fluids. The
model suggests a scaling relationship for the density-dependent behavior of the
hard-sphere system. It also predicts how the second virial coefficients of
fluids with short-range attractions affect their free-volume distributions.Comment: 7 pages, 5 figure
Spatio-temporal bivariate statistical models for atmospheric trace-gas inversion
Atmospheric trace-gas inversion refers to any technique used to predict
spatial and temporal fluxes using mole-fraction measurements and atmospheric
simulations obtained from computer models. Studies to date are most often of a
data-assimilation flavour, which implicitly consider univariate statistical
models with the flux as the variate of interest. This univariate approach
typically assumes that the flux field is either a spatially correlated Gaussian
process or a spatially uncorrelated non-Gaussian process with prior expectation
fixed using flux inventories (e.g., NAEI or EDGAR in Europe). Here, we extend
this approach in three ways. First, we develop a bivariate model for the
mole-fraction field and the flux field. The bivariate approach allows optimal
prediction of both the flux field and the mole-fraction field, and it leads to
significant computational savings over the univariate approach. Second, we
employ a lognormal spatial process for the flux field that captures both the
lognormal characteristics of the flux field (when appropriate) and its spatial
dependence. Third, we propose a new, geostatistical approach to incorporate the
flux inventories in our updates, such that the posterior spatial distribution
of the flux field is predominantly data-driven. The approach is illustrated on
a case study of methane (CH) emissions in the United Kingdom and Ireland.Comment: 39 pages, 8 figure
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Genetic and Environmental Associations With Pediatric Cerebral Arteriopathy.
Osteofibrous dysplasia of the proximal tibia: an illustrative case report
A 5 years old girl presented 3 years back with pain and swelling over the upper right leg for 2 years duration. X-ray, CT and MRI revealed osteolytic well defined lesion 2.5 × 2 cm in the meta-diaphyseal region of the proximal tibia with pathological fracture of anterolateral cortex. Child underwent thorough curettage of the lesion and the defect was filled with allograft (iliac crest graft) from mother which was harvested in an adjacent operation theatre. The limb was protected with a plaster splint for a period of 3 months. The graft gradually consolidated and new bone formation was apparent by 6 months. Remodelling of the medullary canal occurred at 1 year follow up. Child has been followed up to 3 years (till date) and there is no evidence of recurrence. The case illustrates that osteofibrous dyplasia can be effectively treated by curettage and replacement of defect by allograft from parents.
Controllability of nonlinear higher-order fractional damped stochastic systems involving multiple delays
This paper is concerned with the controllability problem for higher-order fractional damped stochastic systems with multiple delays, which involves fractional Caputo derivatives of any different orders. In the process of proof, we have proposed the controllability of considered linear system by establishing a controllability Grammian matrix and employing a control function. Sufficient conditions for the considered nonlinear system concerned to be controllable have been derived by constructing a proper control function and utilizing the Banach fixed point theorem with Burkholder–Davis–Gundy’s inequality. Finally, two examples are provided to emphasize the applicability of the derived results
Optical and electronic properties of sub-surface conducting layers in diamond created by MeV B-implantation at elevated temperatures
Boron implantation with in-situ dynamic annealing is used to produce highly
conductive sub-surface layers in type IIa (100) diamond plates for the search
of a superconducting phase transition. Here we demonstrate that high-fluence
MeV ion-implantation, at elevated temperatures avoids graphitization and can be
used to achieve doping densities of 6 at.%. In order to quantify the diamond
crystal damage associated with implantation Raman spectroscopy was performed,
demonstrating high temperature annealing recovers the lattice. Additionally,
low-temperature electronic transport measurements show evidence of charge
carrier densities close to the metal-insulator-transition. After electronic
characterization, secondary ion mass spectrometry was performed to map out the
ion profile of the implanted plates. The analysis shows close agreement with
the simulated ion-profile assuming scaling factors that take into account an
average change in diamond density due to device fabrication. Finally, the data
show that boron diffusion is negligible during the high temperature annealing
process.Comment: 22 pages, 6 figures, submitted to JA
Developing a three-dimensional (3D) assessment method for clubfoot-A study protocol
© 2018 Ganesan, Luximon, Al-Jumaily, Yip, Gibbons and Chivers. Background: Congenital talipes equinovarus (CTEV) or clubfoot is a common pediatric congenital foot deformity that occurs 1 in 1,000 live births. Clubfoot is characterized by four types of foot deformities: hindfoot equinus; midfoot cavus; forefoot adductus; and hindfoot varus. A structured assessment method for clubfoot is essential for quantifying the initial severity of clubfoot deformity and recording the progress of clubfoot intervention. Aim: This study aims to develop a three-dimensional (3D) assessment method to evaluate the initial severity of the clubfoot and monitor the structural changes of the clubfoot after each casting intervention. In addition, this study explores the relationship between the thermophysiological changes in the clubfoot at each stage of the casting intervention and in the normal foot. Methods: In this study, a total of 10 clubfoot children who are < 2 years old will be recruited. Also, the data of the unaffected feet of a total of 10 children with unilateral clubfoot will be obtained as a reference for normal feet. A Kinect 3D scanner will be used to collect the 3D images of the clubfoot and normal foot, and an Infrared thermography camera (IRT camera) will be used to collect the thermal images of the clubfoot. Three-dimensional scanning and IR imaging will be performed on the foot once a week before casting. In total, 6-8 scanning sessions will be performed for each child participant. The following parameters will be calculated as outcome measures to predict, monitor, and quantify the severity of the clubfoot: Angles cross section parameters, such as length, width, and the radial distance; distance between selected anatomical landmarks, and skin temperature of the clubfoot and normal foot. The skin temperature will be collected on selected areas (forefoot, mid foot, and hindfoot) to find out the relationship between the thermophysiological changes in the clubfoot at each stage of the casting treatment and in the normal foot. Ethics: The study has been reviewed and approved on 17 August 2016 by the Sydney Children's Hospitals Network Human Research Ethics Committee (SCHN HREC), Sydney, Australia. The Human Research Ethics Committee (HREC) registration number for this study is: HREC/16/SCHN/163
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