3,458 research outputs found
Virtual reality for the built environment: A critical review of recent advances
This paper reviews the current state of the art for Virtual Reality (VR) and Virtual Environment (VE) applications in the field of the built environment. The review begins with a brief overview of technological components involved in enabling VR technology. A classification framework is developed to classify 150 journal papers in order to reveal the scholarly coverage of VR and VE from 2005 to 2011, inclusive. The classification framework summarizes achievements, established knowledge, research issues and challenges in the area. The framework is based on four layers of VR: concept and theory, implementation, evaluation and industrial adoption. These layers encompass architecture and design, urban planning and landscape, engineering, construction, facility management, lifecycle integration, training and education. This paper also discusses various representative VR research work in line with the classification framework. Finally the paper predicts future research trends in this area
3D Phase Field Modeling of Multi-Dendrites Evolution in Solidification and Validation by Synchrotron X-ray Tomography
In this paper, the dynamics of multi-dendrite concurrent growth and coarsening of an
Al-15 wt.% Cu alloy was studied using a highly computationally efficient 3D phase field model
and real-time synchrotron X-ray micro-tomography. High fidelity multi-dendrite simulations were
achieved and the results were compared directly with the time-evolved tomography datasets to
quantify the relative importance of multi-dendritic growth and coarsening. Coarsening mechanisms under different solidification conditions were further elucidated. The dominant coarsening
mechanisms change from small arm melting and interdendritic groove advancement to coalescence
when the solid volume fraction approaches ~0.70. Both tomography experiments and phase field
simulations indicated that multi-dendrite coarsening obeys the classical Lifshitz–Slyozov–Wagner
theory R
n − R
n
0 = kc(t − t0), but with a higher constant of n = 4.
3D phase field modeling of multi-dendrites evolution in solidification and validation by synchrotron x-ray tomography
© 2021 by the authors. Licensee MDPI, Basel, Switzerland. In this paper, the dynamics of multi-dendrite concurrent growth and coarsening of an Al-15 wt.% Cu alloy was studied using a highly computationally efficient 3D phase field model and real-time synchrotron X-ray micro-tomography. High fidelity multi-dendrite simulations were achieved and the results were compared directly with the time-evolved tomography datasets to quantify the relative importance of multi-dendritic growth and coarsening. Coarsening mechanisms under different solidification conditions were further elucidated. The dominant coarsening mechanisms change from small arm melting and interdendritic groove advancement to coalescence when the solid volume fraction approaches ~0.70. Both tomography experiments and phase field simulations indicated that multi-dendrite coarsening obeys the classical Lifshitz–Slyozov–Wagner theory Rn − Rn0=kc(t − t0), but with a higher constant of n = 4.3
Tat peptide-admixed elastic liposomal formulation of hirsutenone for the treatment of atopic dermatitis in NC/Nga mice
Myung Joo Kang1, Jae Yoon Eum1, Mi Sook Jeong2, Sang Han Park1, Ki Young Moon1, Mean Hyung Kang1, Min Soo Kim1, Sun Eun Choi1, Min Won Lee1, Do Ik Lee1, Hyoweon Bang2, Chung Soo Lee2, Seong Soo Joo3, Kapsok Li2, Mi-Kyung Lee2, Seong Jun Seo2, Young Wook Choi11College of Pharmacy, ChungAng University, Heuksuk-dong, Dongjak-gu, Seoul, 2College of Medicine, Chung-Ang University, Heuksukdong, Dongjak-gu, Seoul, 3Division of Marine Molecular Biotechnology, Gangneung-Wonju National University, Gangneung, South KoreaBackground: The aim of the present study was to enhance a topical delivery of hirsutenone (HST), a naturally occuring immunomodulator, employing Tat peptide-admixed elastic liposomes (EL/T).Methods: HST-loaded EL, consisting of phosphatidylcholine and Tween 80 (85:15 w/w%), were prepared using thin film hydration method. By adding Tat peptide to EL (0.16 w/w%), EL/T were formulated. The in vitro skin permeation of HST was examined using a Franz diffusion cell mounted with depilated mouse skin. Lesions for atopic dermatitis (AD) were induced by a topical application of diphenylcyclopropenone to NC/Nga mice. Therapeutic improvements of AD were evaluated by clinical skin severity scores. Immunological analyses on inducible nitric oxide synthase and cyclooxygenase-2 levels in the skin and interleukin (IL)-4, IL-13, immunoglobulin E, and eosinophil levels in the blood were also performed.Results: EL systems were superior to conventional cream, revealing greater flux values in a permeation study. The addition of Tat peptide further increased the skin permeation of HST. In an efficacy study with AD-induced NC/Nga mice, an HST-containing EL/T formulation brought a significant improvement in both skin severity score and immune-related responses for the levels of nitric oxide synthase, cyclooxygenase-2, IL-4, IL-13, immunoglobulin E, and eosinophils.Conclusion: A novel EL/T formulation was successfully developed for topical delivery of HST to treat AD.Keywords: hirsutenone, elastic liposomes, atopic dermatitis, NC/Nga mice, Tat peptid
Photometric redshift estimation of galaxies in the DESI Legacy Imaging Surveys
The accurate estimation of photometric redshifts plays a crucial role in
accomplishing science objectives of the large survey projects. The
template-fitting and machine learning are the two main types of methods applied
currently. Based on the training set obtained by cross-correlating the DESI
Legacy Imaging Surveys DR9 galaxy catalogue and SDSS DR16 galaxy catalogue, the
two kinds of methods are used and optimized, such as EAZY for template-fitting
approach and CATBOOST for machine learning. Then the created models are tested
by the cross-matched samples of the DESI Legacy Imaging SurveysDR9 galaxy
catalogue with LAMOST DR7, GAMA DR3 and WiggleZ galaxy catalogues. Moreover
three machine learning methods (CATBOOST, Multi-Layer Perceptron and Random
Forest) are compared, CATBOOST shows its superiority for our case. By feature
selection and optimization of model parameters, CATBOOST can obtain higher
accuracy with optical and infrared photometric information, the best
performance (, and per cent) with
, and is achieved. But EAZY can provide
more accurate photometric redshift estimation for high redshift galaxies,
especially beyond the redhisft range of training sample. Finally, we finish the
redshift estimation of all DESI DR9 galaxies with CATBOOST and EAZY, which will
contribute to the further study of galaxies and their properties.Comment: Accepted for publication in MNRAS. 14 pages, 9 figures, 11 table
Operando study of the dynamic evolution of multiple Fe-rich intermetallics of an Al recycled alloy in solidification by synchrotron X-ray and machine learning
Using synchrotron X-ray diffraction, tomography and machine-learning enabled phase segmentation strategy, we have studied under operando conditions the nucleation, co-growth and dynamic interplays among the dendritic and multiple intermetallic phases of a typical recycled Al alloy (Al5Cu1.5Fe1Si, wt.%) in solidification with and without ultrasound. The research has revealed and elucidated the underlying mechanisms that drive the formation of the very complex and convoluted Fe-rich phases with rhombic dodecahedron and 3D skeleton networks (the so-called Chinese-script type morphology). Through statistical microstructural analyses and numerical modelling of the ultrasound melt processing, the research has demonstrated that a short period of ultrasound processing of just 7 s in the liquid state is able to reduce the average size of the α-Al dendrites and the Fe-containing intermetallic phases by ∼5 times compared to the cases without ultrasound. For the first time, this work has revealed fully the nucleation and growth dynamics of the convoluted morphology of the Fe-containing intermetallic phases in 4D domain. The research has also demonstrated clearly the beneficial effects of applying ultrasound to control the Fe phases' morphology in recycled Al alloys and it is one of the most effective and green processing strategies
Long-term prognosis of symptomatic isolated middle cerebral artery disease in Korean stroke patients
<p>Abstract</p> <p>Background</p> <p>This study aimed to investigate the long-term mortality and recurrence rate of stroke in first-time stroke patients with symptomatic isolated middle cerebral artery disease (MCAD) under medical management.</p> <p>Methods</p> <p>We identified 141 first ever stroke patients (mean age, 64.4 ± 12.5 years; 53% male) with symptomatic isolated MCAD. MCAD was defined as significant stenosis of more than 50% or occlusion of the MCA as revealed by MR angiography. The median follow-up was 27.7 months. We determined a cumulative rate of stroke recurrence and mortality by Kaplan-Meier survival analyses and sought predictors using the Cox proportional hazard model.</p> <p>Results</p> <p>The cumulative composite outcome rate (stroke recurrence or any-cause death) was 14%, 19%, 22%, and 28% at years 1, 2, 3, and 5, respectively. The annual recurrence rate of stroke was 4.1%. The presence of diabetes mellitus was the only significant independent predictor of stroke recurrence or any cause of death in multivariate analyses of Cox proportional hazard model adjusted for any plausible potential confounding factors.</p> <p>Conclusions</p> <p>We estimated the long-term prognosis of stroke patients with isolated symptomatic MCAD under current medical management in Korea. Diabetes mellitus was found to be a significant predictor for stroke recurrence and mortality.</p
KSn4(PO4)(3)
The crystal structure of potassium tetratin(Ⅱ) tris(orthophosphate), KSn4(PO4)(3), obtained by hydrothermal synthesis, has been determined from single-crystal X-ray diffraction data. The structure consists of [Sn4(PO4)(3)] units sharing common corners, which leads to a three-dimensional network structure and generates cages along the c direction. The cages are occupied by K atoms on threefold axes
Synthesis, Characterization, and Photovoltaic Properties of Soluble TiOPc Derivatives
We have synthesized soluble TiOPc derivatives containing alkoxy groups for use as additives in dye-sensitized solar cells (DSSCs). The DSSC devices containing these TiOPc derivatives exhibited short-circuit current densities of 8.49~10.04 mA/cm2 and power conversion efficiencies of 2.73~3.62 % under AM 1.5 illumination and 100 mW/cm2 irradiation
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