A novel double-stator, double-rotor brushless electrical continuously variable transmission (E-CVT) system is proposed. This machine incorporates an inner stator which can fully utilize the space ...inside the inner rotor so as to reduce the volume of the machine. This design is based on magnetic flux modulating and magnetic gear effect to make the E-CVT system work in different operating modes. Different control modes of this proposed machine are also discussed and analyzed, including pure electric mode, hybrid mode, and battery charging mode. Time-stepping finite element method (TS-FEM) is used to analyze the dynamic performance of the machine. TS-FEM simulation results are reported to verify the validity of the proposed design.
The microstructures and tensile properties of Ti-44Al-6V-3Nb-0.3Y (at. %) alloy before and after hot rolling were investigated systematically. SEM results indicated that the as-rolled TiAl sheet was ...characterized by completely dynamically recrystallizated microstructures, except some refined lamellar colonies in the back end, which are primarily caused by the temperature drop during canned forging and subsequent pack rolling. By TEM analysis, the coarsening of γ lamellae by α lath decomposition during hot rolling are found. Meanwhile, by EBSD measurements, the phase composition and grain features of the as-forged and the as-rolled conditions were characterized and compared. Additionally, the tensile properties were tested to find that the room temperature tensile strength decreased obviously after hot rolling, with yield strength decreasing from 620 MPa to 520 MPa along transverse direction (TD) and to 485 MPa in rolling direction (RD), and the UTS from 680 MPa to 598 MPa and 556 MPa respectively. The reason for the degradation of the tensile strength is interpreted detailedly. After being heat-treated in single α phase field, beta phase was eliminated from current deformed TiAl alloy and the tensile properties were enhanced obviously.
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► A beta gamma TiAl sheet is fabricated by IM route and its microstructure is studied. ► The coarsening of γ lamellae by α lath decomposition takes place during rolling. ► The RT tensile strength after rolling is decreased and the reason is discussed. ► After treatment above T
α, β phase disappears and the tensile properties are improved.
Temperature programmed combustions (TPC) of Yang-Quan anthracite, Liao-Cheng lean coal and Li-Yan bituminous coal in oxy-fuel atmosphere were conducted in a thermogravimetric analyzer and ...characteristic parameters were deduced from the TG-DTG curves. The results showed that combustion got harder to progress as the coalification degree increasing. Within range of 40%, effect of heightening O
2
concentration favored the combustion process, but beyond this zone, the effect leveled off. The model-fitting mathematical approach was used to evaluated the kinetic triplet (
f
(α), E, A) through Coats–Redfern method. The calculation showed that
D
3
-Jander was the proper reaction model and the evaluations of
E
and
A
validated the experimental results.
A novel electrical continuously variable transmission (E-CVT) system is presented and analyzed based on harmonic spectra analysis of magnetic fields. Two rotors and one stator are integrated within ...one electric machine so as to keep the whole system compact. The main merits of this proposed torque transmission machine are its brushless structure, improved torque density, reduced stator end winding length, and reduced copper loss. The operating principle of the machine is described and its steady-state and transient performances are analyzed using time-stepping finite element method (TS-FEM). FEM results are used to confirm and validate the superior performance of the proposed machine.
A Spatio-Temporal Approach for Apathy Classification Das, Abhijit; Niu, Xuesong; Dantcheva, Antitza ...
IEEE transactions on circuits and systems for video technology,
05/2022, Letnik:
32, Številka:
5
Journal Article
Recenzirano
Apathy is characterized by symptoms such as reduced emotional response, lack of motivation, and limited social interaction. Current methods for apathy diagnosis require the patient's presence in a ...clinic and time consuming clinical interviews, which are costly and inconvenient for both, patients and clinical staff, hindering among other large-scale diagnostics. In this work, we propose a novel spatio-temporal framework for apathy classification, which is streamlined to analyze facial dynamics and emotion in videos. Specifically, we divide the videos into smaller clips, and proceed to extract associated facial dynamics and emotion-based features. Statistical representations/descriptors based on each feature and clip serve as input of the proposed Gated Recurrent Unit (GRU)-architecture. Temporal representations of individual features at the lower level of the proposed architecture are combined at deeper layers of the proposed GRU architecture, in order to obtain the final feature-set for apathy classification. Based on extensive experiments, we show that fusion of characteristics such as emotion and facial dynamics in proposed deep-bi-directional GRU obtains an accuracy of 95.34% in apathy classification.
Objectives
To report the association of lifestyle factors and plasma vitamin B-12 with hyperhomocysteinemia in a large sample of men and women living in a region of China where there is an increased ...risk of NTDs.
Design
Community-based, cross-sectional study of Lvliang City, Shanxi Province, China.
Setting
Hyperhomocysteinemia is an independent risk factor for cardiovascular disease (CVD) and a sensitive marker of vitamin B-12 and folate deficiency.
Participants
A total of 2355 (1044 men and 1311 women) participants born before 1 January 1958 (≥55 years of age) and living in Lvliang City for at least 2 months a year were included.
Measurements
The participants were assessed regarding demographic characteristics, height, weight, as well as having a physical examination and blood sampling for serum cholesterol, total homocysteine (tHcy), folate, and vitamin B12 levels.
Results
The median (25th–75th percentile) tHcy concentration was 21.5 (15.8–33.6)
µ
mol/L in men and 18.0 (13.4–24.8)
µ
mol/L in women. The overall prevalence of hyperhomocysteinemia (tHcy ≥15
µ
mol/L) was 72.6% (84.3% in men and 63.2% in women), inversely correlated with folate (r=–0.230, P=0.006) and vitamin B-12 (r=–0.540, P<0.001), and positively correlated with uric acid (r=0.054, P<0.001). Vitamin B-12 and folate deficiency, older age, and male gender were associated with elevated tHcy; with vitamin B-12 deficiency being the strongest.
Conclusions
Plasma tHcy concentration and hyperhomocysteinemia were significantly higher in this population than in previously studied populations. Vitamin B-12 and folate supplementation, concomitant lifestyle changes such as smoking cessation, and lipid-lowering treatments may help to decrease plasma tHcy concentrations and reduce the CVD risk in this population.
This paper presents a novel magnetless double-rotor flux switching motor for low cost cooling fan application. By creatively incorporating concentrated toroidal windings into a double-rotor ...middle-stator structure, the proposed motor not only realizes the flux switching feature, but also shortens the end-windings to improve its operational efficiency. To achieve a better performance, the motor dimensions, especially the stator and rotor pole arcs, are optimized. Meanwhile, with the introduction of a stepped air-gap, the torque at any rotor position is boosted and problems with zero output torque at starting is successfully avoided. The final optimized motor is analyzed using finite element method, and its validity is confirmed by the simulation results.
ABSTRACT
An increasing number of white dwarf stars shows atmospheric chemical composition polluted by heavy elements accreted from debris disc material. The existence of such debris discs strongly ...suggests the presence of one or more planet(s) whose gravitational interaction with rocky planetesimals is responsible for their disruption by tidal effect. The ZZ Ceti pulsator and polluted DAZ white dwarf GD 133 are good candidates for searching such a potential planet. We started in 2011 a photometric follow-up of its pulsations. As a result of this work in progress, we used the data gathered from 2011 to 2015 to make an asteroseismological analysis of GD 133, providing the star parameters from the best-fitting model with M/M⊙ = 0.630 ± 0.002, Teff = 12 400 ± 70 K, log(MHe/M) = −2.00 ± 0.02, log(MH/M) = −4.50 ± 0.02, and determining a rotation period of ≈7 d.
The high temperature deformation behaviors of Ti-45Al-2Nb-1.5V-1Mo-Y alloy were investigated in the temperature range 1100–1250 °C and the strain rate range 0.001–1.0 s−1. The true stress-strain ...curves exhibit typical work hardening and flow softening features; The peak stress of current alloy decreases with increasing temperature and decreasing strain rate, which can be represented by a hyperbolic sine equation using the Zener-Hollomon parameter. Thanks to the additions of element Mo and V, and the resulting B2 phase, this alloy possesses a low activation energy value of 370 kJ/mol, as well as a wide processing window of temperature above 1150 °C and strain rate under 0.1 s−1. The deformed microstructure consists of dominated DRX areas plus several remnant lamellar colonies; the inhomogeneous deformation microstructure is ascribed to the anisotropic plastic flow of lamellar colonies. By TEM observation and EBSD analysis further, the deformation mechanism of current alloy is concluded as dislocation slip and mechanical twins.
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► Soft β/B2 phase contributes to hot workability of TiAl alloy. ► This β γ-TiAl alloy possesses low Q value of 370 kJ/mol and wide processing window. ► The deformation mechanism is concluded as dislocation slip and mechanical twinning.
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