20,371 research outputs found
ENGINE PERFORMANCE ON ATOMIZATION OF FUEL INJECTOR: A REVIEW
The impact of the fuel injection of fuel atoms on engine performance has been investigated to improve fuel efficiency and waste disposal features. The fuel swirl method for injection atomization was evaluated both by the analysis of the fuel flow and the sample test. The goal of the paper is to establish good fuel atomization over the range of engine performance. As a result of our studies, it has been concluded that the desired atomization can be achieved when gasoline is thrown into a circular motion. Fuel spray and atomization features play an important role in the performance of internal combustion engines. An atomization study to evaluate the numerical fuel injection used in the IGC (Inner Guide-vane Combustor) under various combination and performance conditions has been performed to determine the suspension of the proposed fuel injection to be used in the IGC. Additional results have shown that a single-hole fuel injection, forward injection direction, and a splash of
Forman's Ricci curvature - From networks to hypernetworks
Networks and their higher order generalizations, such as hypernetworks or
multiplex networks are ever more popular models in the applied sciences.
However, methods developed for the study of their structural properties go
little beyond the common name and the heavy reliance of combinatorial tools. We
show that, in fact, a geometric unifying approach is possible, by viewing them
as polyhedral complexes endowed with a simple, yet, the powerful notion of
curvature - the Forman Ricci curvature. We systematically explore some aspects
related to the modeling of weighted and directed hypernetworks and present
expressive and natural choices involved in their definitions. A benefit of this
approach is a simple method of structure-preserving embedding of hypernetworks
in Euclidean N-space. Furthermore, we introduce a simple and efficient manner
of computing the well established Ollivier-Ricci curvature of a hypernetwork.Comment: to appear: Complex Networks '18 (oral presentation
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Heading direction with respect to a reference point modulates place-cell activity.
The tuning of neurons in area CA1 of the hippocampus emerges through a combination of non-spatial input from different sensory modalities and spatial information about the animal's position and heading direction relative to the spatial enclosure being navigated. The positional modulation of CA1 neuronal responses has been widely studied (e.g. place tuning), but less is known about the modulation of these neurons by heading direction. Here, utilizing electrophysiological recordings from CA1 pyramidal cells in freely moving mice, we report that a majority of neural responses are modulated by the heading-direction of the animal relative to a point within or outside their enclosure that we call a reference point. The finding of heading-direction modulation relative to reference points identifies a novel representation encoded in the neuronal responses of the dorsal hippocampus
Risk-based autonomous vehicle motion control with considering human driverās behaviour
The selected motions of autonomous vehicles (AVs) are subject to the constraints from the surrounding traffic environment, infrastructure and the vehicleās dynamic capabilities. Normally, the motion control of the vehicle is composed of trajectory planning and trajectory following according to the surrounding risk factors, the vehiclesā capabilities as well as tyre/road interaction situations. However, pure trajectory following with a unique path may make the motion control of the vehicle be too careful and cautious with a large amount of steering effort. To follow a planned trajectory, the AVs with the traditional path-following control algorithms will correct their states even if the vehicles have only a slight deviation from the desired path or the vehicle detects static infrastructure like roadside trees. In this case, the safety of the AVs can be guaranteed to some degree, but the comfort and sense of hazards for the drivers are ignored, and sometimes the AVs have unusual motion behaviours which may not be acceptable to other road users. To solve this problem, this study aims to develop a safety corridor-based vehicle motion control approach by investigating human-driven vehicle behaviour and the vehicleās dynamic capabilities. The safety corridor is derived by the manoeuvring action feedback of actual drivers as collected in a driving simulator when presented with surrounding risk elements and enables the AVs to have safe trajectories within it. A corridor-based Nonlinear Model Predictive Control (NMPC) has been developed which controls the vehicle state to achieve a smooth and comfortable trajectory while applying trajectory constraints using the safety corridor. The safety corridor and motion controller are assessed using four typical scenarios to show that the vehicle has a human-like or human-oriented behaviour which is expected to be more acceptable for both drivers and other road users
A Sparse Stress Model
Force-directed layout methods constitute the most common approach to draw
general graphs. Among them, stress minimization produces layouts of
comparatively high quality but also imposes comparatively high computational
demands. We propose a speed-up method based on the aggregation of terms in the
objective function. It is akin to aggregate repulsion from far-away nodes
during spring embedding but transfers the idea from the layout space into a
preprocessing phase. An initial experimental study informs a method to select
representatives, and subsequent more extensive experiments indicate that our
method yields better approximations of minimum-stress layouts in less time than
related methods.Comment: Appears in the Proceedings of the 24th International Symposium on
Graph Drawing and Network Visualization (GD 2016
Adsorption efficiency of banana blossom peels (musa acuminata colla) adsorbent for chromium (VI) removal
The discharge of waste from industries into water has caused heavy metal pollution posing health risk to
biota such as lead and chromium (VI). Once the water has been polluted, it will limit the accessibility to
clean freshwater. Therefore, this paper aims to evaluate the adsorption efficiency of banana blossom
peels for the chromium (Cr) (VI) removal under different pH (1, 4, 7, and 10). Extraction of banana blosļæ½som peels adsorbent was carried out via chemical treatment using 0.1 M of HCI and 5% (w/v) NaOH soluļæ½tion. The morphology and functional groups of extracted banana blossom peels adsorbent were then
characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy
(FTIR), and subsequently, the Cr (VI) removal efficiency was examined using ultravioletāvisible specļæ½troscopy (UVāVIS). The extracted banana blossom peels adsorbent is found to have wavy surface with
shallow dents. Results demonstrated that adsorbent at pH 10 have the optimum removal of Cr (VI) with
18.87% followed by pH 7 (18.36%), pH 4 (12.28%) and pH 1 (12.00%) after 8 h. The maximum Cr (VI)
adsorption capacity is 227.27 mg/g. In this study, the pseudo-second-order model best describes the
adsorption process. Langmuir isotherm model is more favorable with high correlation coefficient of
0.99. In conclusion, adsorbent extracted from banana blossom has the potential to be used for Cr (VI)
removal in water sources and reduce disposal of agricultural wastes by transforming it into a valuable
material
Breast cancer biomarkers predict weight loss after gastric bypass surgery
<p>Abstract</p> <p>Background</p> <p>Obesity has long been associated with postmenopausal breast cancer risk and more recently with premenopausal breast cancer risk. We previously observed that nipple aspirate fluid (n) levels of prostate specific antigen (PSA) were associated with obesity. Serum (s) levels of adiponectin are lower in women with higher body mass index (BMI) and with breast cancer. We conducted a prospective study of obese women who underwent gastric bypass surgery to determine: 1) change in n- and s-adiponectin and nPSA after surgery and 2) if biomarker change is related to change in BMI. Samples (30-s, 28-n) and BMI were obtained from women 0, 3, 6 and 12 months after surgery.</p> <p>Findings</p> <p>There was a significant increase after surgery in pre- but not postmenopausal women at all time points in s-adiponectin and at 3 and 6 months in n-adiponectin. Low n-PSA and high s-adiponectin values were highly correlated with decrease in BMI from baseline.</p> <p>Conclusions</p> <p>Adiponectin increases locally in the breast and systemically in premenopausal women after gastric bypass. s-adiponectin in pre- and nPSA in postmenopausal women correlated with greater weight loss. This study provides preliminary evidence for biologic markers to predict weight loss after gastric bypass surgery.</p
Inferring Population Preferences via Mixtures of Spatial Voting Models
Understanding political phenomena requires measuring the political
preferences of society. We introduce a model based on mixtures of spatial
voting models that infers the underlying distribution of political preferences
of voters with only voting records of the population and political positions of
candidates in an election. Beyond offering a cost-effective alternative to
surveys, this method projects the political preferences of voters and
candidates into a shared latent preference space. This projection allows us to
directly compare the preferences of the two groups, which is desirable for
political science but difficult with traditional survey methods. After
validating the aggregated-level inferences of this model against results of
related work and on simple prediction tasks, we apply the model to better
understand the phenomenon of political polarization in the Texas, New York, and
Ohio electorates. Taken at face value, inferences drawn from our model indicate
that the electorates in these states may be less bimodal than the distribution
of candidates, but that the electorates are comparatively more extreme in their
variance. We conclude with a discussion of limitations of our method and
potential future directions for research.Comment: To be published in the 8th International Conference on Social
Informatics (SocInfo) 201
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