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31.
The absorption of pure chlorine into aqueous sodium carbonate solutions accompanied by the desorption of carbon dioxide was studied both theoretically and experimentally. The absorption rates of chlorine and the desorption rates of carbon dioxide were measured at 25°C using a baffled agitated vessel operated batchwise. The experimental results were analyzed with the chemical absorption theory based on the Lévěque model. The measured absorption and desorption rates were in good agreement with the theoretical predictions. 相似文献
32.
Mi Young Choi S. Anandhan Ji Ho Youk Du Hyun Baik Seung Won Seo Han Sup Lee 《应用聚合物科学杂志》2006,102(3):3048-3055
Nanocomposites based on thermoplastic elastomeric polyurethane (TPU) and layered silicate clay were prepared by in situ synthesis. The properties of nanocomposites of TPU with unmodified clay were compared with that of organically modified clay. The nanocomposites of the TPU and organomodified clay showed better dispersion and exhibited superior properties. Exfoliation of the clay layers was observed at low organoclay contents, whereas an intercalated morphology was observed at higher clay contents. As one of major purposes of this study, the effect of the silicate layers in the nanocomposites on the order–disorder transition temperature (TODT) of the TPU was evaluated from the intensity change of the hydrogen‐bonded and free carbonyl stretching peaks and from the peak position change of the N? H bending peak. The presence of the organoclay increased TODT by approximately 10°C, which indicated improved stability in the phase‐separated domain structure. The layered silicate clay caused a tremendous improvement in the stiffness of the TPU; meanwhile, a reduction in the ultimate elongation was observed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3048–3055, 2006 相似文献
33.
The extrudate swell effect has not received sufficient attention in modeling the film blowing process. This effect is addressed in this paper, and as an ab initio study, only viscous fluids were considered. The problem region was separated into two zones; the extrudate swell zone and the film blowing zone. The annular extrudate swell problem was solved using a finite element method. The film blowing process was modeled following Pearson and Petrie's (4) work. Although only viscous fluids were considered, the simulation results show a remarkable difference when swelling was included in the modeling. Viscoelastic fluids, which are more realistic for polymer melts, were not investigated here because of the so called high Weisenberg number problem. This is an open area still under investigation. 相似文献
34.
Dongjin Seo 《Polymer》2005,46(17):6482-6493
Foam reaction injection molding (FRIM) is one of the most popular and useful processes for producing polyurethane foam with a complex geometry. A theoretical model which includes chemical reactions, foaming, and mold filling was developed to analyze FRIM. Energy balance equation was derived by considering polyurethane reaction, water-isocyanate reaction, and evaporation of physical blowing agents. Density and viscosity model was proposed for the bubble suspension, which was assumed to be a homogeneous phase. Based on the theoretical model, three-dimensional numerical simulation for mold filling of the polyurethane foam was carried out to predict flow field, flow front advancement, and density distribution during mold filling. Mold filling of a refrigerator cavity was investigated numerically. The density and thermal conductivity of the foam in the flow front was higher than those in the initially filled region. 相似文献
35.
Chan-Yeol Seo Seung-Jun Choi Jeon Choi Choong-Nyeon Park Paul. S. Lee Jai-Young Lee 《Journal of Alloys and Compounds》2003,350(1-2):324-331
AB5-type intermetallic compounds were prepared by arc-melting in argon atmosphere. The composition of a stoichiometric compound LaNi3.6Al0.4Co0.7Mn0.3 with a hexagonal CaCu5 structure was varied by stoichiometric and nonstoichiometric addition of Ti. With the increase of the Ti y0.05 content in LaNi3.6Al0.4Co0.7Mn0.3Tiy, the hydrogen storage capacity is enhanced, whereas when y=0.1–0.3, it is decreased. The discharge capacity and cyclability are increased considerably by addition of titanium in the range of 0.02–0.1 with a maximum value at about 0.1%. The highest maximum capacity is achieved for a nonstoichiometric addition of 0.05% Ti. The kinetic properties are also additionally improved by the formation of a titanium-rich second phase. This can explain the improvement of the capacity for alloys with low Ti content. The decrease in capacity for high Ti content was also correlated with the amount of the Ti-rich phase. Therefore, the improvement of kinetics are due to the catalytic effect, grain boundary diffusion effect or more pronounced alloy pulverization upon cycling. This study has been aimed to improve the electrode properties of a series of multicomponent LaNi3.6Al0.4Co0.7Mn0.3Tiy (y=0.0, 0.02, 0.05, 0.1, 0.2, 0.3) alloys which have mutual complementary properties. All the prepared alloys have been subjected to analyses by EDS, SEM and XRD. In order to determine the hydrogen storage capacity, the pressure composition isotherms (P–C–T curves) have been used. The metal hydride electrodes were characterized by galvanostatic cycling test. 相似文献
36.
Sang Chul Seo Hyun Jung Kim Byung Ho Park Kwang Suk Son Sung Keun Lee Sun Bae Kang Donggyu Kim 《Metals and Materials International》2006,12(3):273-277
In a continuous casting steelmaking operation, the surface of a slab is under a condition that can be characterized as high-temperature,
low-cycle fatigue in which the tensile and compressive stress is repeatedly developed. For this reason, for the evaluation
of the hot ductility of a slab, considering the fatigue deformation is more feasible before a tensile or compressive test.
In this study, the effects of low-cycle fatigue on the hot ductility of steels with a carbon content of 0.06–0.8 wt.% are
investigated at various temperatures. For a carbon content of 0.06%, there were no significant differences between the RA
values from a simple tensile test and those from a tensile test after fatigue deformation. The tendency of ductility deterioration
with fatigue deformation is evident in 0.1 %C steel, and is due to the deformation-induced ferrite film that forms around
the prior austenite grain. Conversely, high carbon steel containing 0.8 %C did not show a recovery of hot ductility in a low
temperature region, and the specimen on which the tensile was measured after fatigue showed a higher hot ductility in the
low temperature region, which is thought to result from the pearlite refinement effects. As the results obtained in this work
showed noticeable differences in the hot ductility of carbon steel through the test conditions, it is suggested that for more
accurate data, fatigue deformation be adopted in which the temperature range in an unbending operation is determined in the
steelmaking factory. 相似文献
37.
Takashi Yamauchi Jinsil Hwaryoung Seo Noel Jett Greg Parks Casady Bowman 《International journal of human-computer interaction》2013,29(12):911-921
Computer cursor and mouse activities such as moving, pointing, selecting, and dragging are essential parts of everyday interactions. Yet it is unknown how men and women differ in the way they move computer cursors. This study examines gender differences in movements of computer cursors. In one experiment, the authors measured trajectories of computer cursors every 20 ms in a simple choice-reaching task and tested the extent to which movement features related to controlling and targeting diverge between male and female participants. Results showed significant gender differences in cursor motions. Female participants deviated from the straight path toward the target location to a larger degree than did male participants, and female participants showed more backward motions (deviating backward from the target location) than did male participants. Implications for sources of these gender differences, user interface and input device design, and musculoskeletal disorders in women are also discussed. 相似文献
38.
39.
OBJECTIVE: To investigate the relationship among friction, applied torque, and axial push force on cylindrical handles. BACKGROUND: We have earlier demonstrated that participants can exert greater contact force and torque in an "inward" movement of the hand about the long axis of a gripped cylinder (wrist flexion/forearm supination) than they can in an "outward" hand movement. METHOD: Twelve healthy participants exerted anteriorly directed maximum push forces along the long axis of aluminum and rubber handles while applying deliberate inward or outward torques, no torque (straight), and an unspecified (preferred) torque. RESULTS: Axial push force was 12% greater for the rubber handle than for the aluminum handle. Participants exerted mean torques of 1.1, 0.3, 2.5, and -2.0 Nm and axial push forces of 94, 85, 75, and 65 N for the preferred, straight, inward, and outward trials, respectively. Left to decide for themselves, participants tended to apply inward torques, which were associated with increased axial push forces. CONCLUSION: Axial push force was limited by hand-handle coupling--not the whole body's push strength. Participants appeared to intuitively know that the application of an inward torque would improve their maximum axial push force. Axial push forces were least when a deliberate torque was requested, probably because high levels of torque exertions interfered with the push. APPLICATION: A low-friction handle decreases maximum axial push force. It should be anticipated that people will apply inward torque during maximum axial push. 相似文献
40.
The influence of wall charge distribution on the time lag of address discharge in an AC plasma display panel is investigated using two different reset waveforms: one (typical reset) induces both face and surface discharges and the other (TR reset) induces face discharges only. The measured formative time lag and statistical time lag of address discharge for TR were 21–31 ns and 31–74 ns shorter than the one for the typical reset, respectively. The TR reset resulted in much less increase of statistical time lag than the typical reset when the reset-to-address time interval was increased, and 70 ns smaller deviation of the statistical time lag among different color cells. Calculations show that the TR reset forms a much smoother wall charge profile, which is less susceptible to cell parameter variations, than the typical reset. The observed differences in the time lags of address discharge between different scan lines and color cells are strongly correlated to the differences of the wall charge profile, indicating that a smooth wall charge profile formed by the reset using face discharges only reduces the time lag of address discharge and minimizes the susceptibility of address discharge to cell parameter variation. 相似文献