1,121 research outputs found
Adomian’s decomposition method to modeling power functionally graded thermoelastic materials in heat transfer and thermal stress analysis
This work deals with an iteration method for numerical solving the problem of one-dimensional coupled thermoelasticity under given boundary conditions. This iteration based on the Adomian’s decomposition method. All the material properties have been considered variable on position with a power law. The numerical results have been calculated for different cases of the gradient parameter and the gradient index. The numerical results have been shown in figures. The gradient parameter and the gradient index have significant effects on the temperature increment, the strain, the stress, and the displacement
MaaSim: A Liveability Simulation for Improving the Quality of Life in Cities
Urbanism is no longer planned on paper thanks to powerful models and 3D
simulation platforms. However, current work is not open to the public and lacks
an optimisation agent that could help in decision making. This paper describes
the creation of an open-source simulation based on an existing Dutch
liveability score with a built-in AI module. Features are selected using
feature engineering and Random Forests. Then, a modified scoring function is
built based on the former liveability classes. The score is predicted using
Random Forest for regression and achieved a recall of 0.83 with 10-fold
cross-validation. Afterwards, Exploratory Factor Analysis is applied to select
the actions present in the model. The resulting indicators are divided into 5
groups, and 12 actions are generated. The performance of four optimisation
algorithms is compared, namely NSGA-II, PAES, SPEA2 and eps-MOEA, on three
established criteria of quality: cardinality, the spread of the solutions,
spacing, and the resulting score and number of turns. Although all four
algorithms show different strengths, eps-MOEA is selected to be the most
suitable for this problem. Ultimately, the simulation incorporates the model
and the selected AI module in a GUI written in the Kivy framework for Python.
Tests performed on users show positive responses and encourage further
initiatives towards joining technology and public applications.Comment: 16 page
Garay’s Condition of Deformed Cylindrical and Translation Surfaces in E3
The motivation of the present work is to develop the finiteness property in our work [1, 2, 3, 4] by using Garay’s condition [5]. The mean curvature flow and the finiteness property of the cylindrical surfaces in E3 are investigated. Additionally, the linear deformation of such surfaces is studied. Finally, the translation surfaces are discussed
The Effects of Midline Cerebellar rTMS on Human Pharyngeal Cortical Activity in the Intact Swallowing Motor System
We sought to compare the effects of 10 Hz cerebellar vermis (vs. unilateral hemispheric and sham) repetitive transcranial magnetic stimulation (rTMS) on cortical neuroelectrical activity and thereafter 10 Hz cerebellar vermis (vs. sham) rTMS on swallowing behaviour. Healthy participants (n = 25) were randomly allocated to receive vermis, unilateral hemisphere or sham 10 Hz cerebellar rTMS. Recordings were made using pharyngeal electromyography and manometry catheters, obtaining motor-evoked potentials (MEPs) and pressure recordings. The amplitudes of MEPs elicited using single-pulse TMS delivered to the pharyngeal areas of the motor cortex bilaterally were measured pre- and post-cerebellar stimulation. As in previous studies, abductor policis brevis (APB) MEPs were measured to assess post-rTMS modulation specificity. Swallowing was assessed using a swallowing accuracy task. Measurements were made at baseline and 15-min intervals for an hour post-intervention. Measurements involved TMS being used to elicit 10 MEPs bilaterally over the pharyngeal areas of the motor cortex, over the APB cortical representation adjacent to the pharyngeal area with the lowest resting motor threshold and 5 MEPs bilaterally over pharyngeal areas of the cerebellar hemispheres. Swallowing accuracy was assessed by giving participants 10 attempts to swallow and hit a digital target. Cerebellar vermis rTMS caused significant suppression of cortical pharyngeal MEP amplitudes compared with unilateral rTMS and sham (P = 0.0005, 0.002). APB and cerebellar MEP amplitudes were unaffected as were pharyngeal and APB MEP latencies. Following cerebellar vermis rTMS there was a significant reduction in swallowing accuracy compared with sham (P = 0.001). Our findings demonstrate cerebellar vermis rTMS exerts a suppressive effect on pharyngeal motor cortical activity and swallowing behaviour
Cationic Gemini Surfactants For Carbon Steel In Sea Water
Abstract Corrosion inhibition of carbon steel alloy in sea water by different synthesized gemini surfactants {12-2-12, 14-2-14 and 16-2-16} have been investigated using weight loss, potentiodynamic polarization and surface tension measurements. The data obtained from all the used methods are in good agreement with each other and ensure the excellent inhibition efficiency of the tested surfactants for carbon steel in sea water. The inhibition efficiency increases with increasing the concentration of the studied inhibitors. Also, the adsorption ability of the surfactant molecules on carbon steel surface increases with the increase in the hydrocarbon chain length of the surfactant molecule from 12 to 16 and through 14 C atoms; meanwhile, the isotherm of 16-2-16 declares the formation of multilayer onto the used metal surface. The inhibitive action of the studied surfactants follows the order: 16-2-16 > 14-2-14> 12-2-12. The morphological changes of carbon steel surface were studied by Scanning Electron Microscope [SEM] ] and the study shows well inhibited surface on adding the cationic Gemini surfactants to the immersion solution . [Nessim I .M.; Hamdy A.; Osman M.M. and Shalaby M. N. Inhibitory Effect Of Som
The Homogeneity of Interstellar Oxygen in the Galactic Disk
We present an analysis of high resolution HST Space Telescope Imaging
Spectrograph (STIS) observations of O I 1356 and H I Lyman-alpha absorption in
36 sight lines that probe a variety of Galactic disk environments and include
paths that range over nearly 4 orders of magnitude in f(H_2), over 2 orders of
magnitude in mean sight line density, and that extend up to 6.5 kpc in length.
Consequently, we have undertaken the study of gas-phase O/H abundance ratio
homogeneity using the current sample and previously published Goddard
High-Resolution Spectrograph (GHRS) results. Two distinct trends are identified
in the 56 sight line sample: an apparent decrease in gas-phase oxygen abundance
with increasing mean sight line density and a gap between the mean O/H ratio
for sight lines shorter and longer than about 800 pc. The first effect is a
smooth transition between two depletion levels associated with large mean
density intervals; it is centered near a density of 1.5 cm^-3 and is similar to
trends evident in gas-phase abundances of other elements. Paths less dense than
the central value exhibit a mean O/H ratio of log_10 (O/H) = -3.41+/-0.01 (or
390+/-10 ppm), which is consistent with averages determined for several long,
low-density paths observed by STIS (Andre et al. 2003) and short low-density
paths observed by FUSE (Moos et al. 2002). Sight lines of higher mean density
exhibit an average O/H value of log_10 (O/H) = -3.55+/-0.02 (284+/-12 ppm). The
datapoints for low-density paths are scattered more widely than those for
denser sight lines, due to O/H ratios for paths shorter than 800 pc that are
generally about 0.10 dex lower than the values for longer ones.Comment: 33 pages, including 8 figures and 4 tables; accepted for publication
in ApJ, tentatively in Oct 200
Population-based study of acquired cerebellar ataxia in Al-Kharga district, New Valley, Egypt
Wafaa MA Farghaly1, Hamdy N El-Tallawy1, Ghaydaa A Shehata1, Tarek A Rageh1, Nabil Abdel Hakeem2, Noha M Abo-Elfetoh11Department of Neurology and Psychiatry, Assiut University, Assiut, Egypt; 2Al Azhar University, Assiut Branch, EgyptBackground: The aim of this research was to determine the prevalence and etiology of acquired ataxia in Al-Kharga district, New Valley, Egypt.Methods: A population-based study of acquired ataxia was conducted in a defined geographical region with a total population of 62,583. A door-to-door survey was used to identify cases of acquired cerebellar ataxia. Patients with acquired cerebellar ataxia at any age and of both genders were included. Cases of known inherited cerebellar ataxia, acquired neurological disorders with ataxia as a minor feature, or pure acquired sensory ataxia, were excluded.Results: We identified 17 cases of acquired ataxia, of which eight were vascular, six were an ataxic cerebral palsy subtype, and three involved postencephalitic ataxia. The crude prevalence rate for acquired ataxia was 27.16/100,000 (95% confidence interval [CI]: 14.3–40.1). The mean age of the patients at interview was 31.8 (range 4–72) years, with a male to female ratio of 2.1:1. The most frequent presenting complaint was disturbance of gait (90.7%). The majority (92%) were ambulatory, but only 9.3% were independently self-caring.Conclusion: This population-based study provides an insight into acquired cerebellar ataxia within a defined region, and may inform decisions about the rational use of health care resources for patients with acquired cerebellar ataxia. The most common causes of acquired cerebellar ataxia in this region were cerebrovascular injury and cerebral palsy.Keywords: acquired cerebellar ataxia, prevalence, subtypes, Egyp
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