Simulation on kink-band formation during axial compression of a unidirectional carbon fiber-reinforced plastic constructed by X-ray computed tomography images

X-ray computed tomography was used to obtain cross-sectional images of a unidirectional carbon fiber-reinforced plastic, where fiber locations in each cross-sectional image were identified. The three-dimensional model with fiber waviness was developed by connecting the fiber locations along the fiber direction. Numerical simulation for the initiation and formation of a kink-band during axial compression was performed using the three-dimensional finite element model. The load was increased almost linearly until it reached the compressive strength, after which both load and displacement were decreased, showing snap-back behavior. The matrix yielded locally with the increased axial compression, and fibers started to fall due to insufficient support by the yielded matrix. A kink-band was formed with an increase in the yielded area, and thus, the initiation of a kink-band was defined as the local yielding of the matrix. It was also shown that the kink-band was formed at the longitudinal location at which the average of initial local fiber misalignment angles in the cross-section was relatively large.     

Adaptive timeliness of consensus in presence of crash and timing faults

The Δ$\mathrm{\Delta }$-timed uniform consensus is a stronger variant of the traditional consensus and it satisfies the following additional property: every correct process terminates its execution within a constant time Δ$\mathrm{\Delta }$ (Δ$\mathrm{\Delta }$-timeliness), and no two processes decide differently (uniformity). In this paper, we consider the Δ$\mathrm{\Delta }$-timed uniform consensus problem in presence of _fc$f_{\mathrm{c}}$ crash processes and _ft$f_{\mathrm{t}}$ timing-faulty processes, and propose a Δ$\mathrm{\Delta }$-timed uniform consensus algorithm. The proposed algorithm is adaptive in the following sense: it solves the Δ$\mathrm{\Delta }$-timed uniform consensus when at least _ft+1$f_{\mathrm{t}}+1$ correct processes exist in the system. If the system has less than _ft+1$f_{\mathrm{t}}+1$ correct processes, the algorithm cannot solve the Δ$\mathrm{\Delta }$-timed uniform consensus. However, as long as _ft+1$f_{\mathrm{t}}+1$ processes are non-crashed, the algorithm solves (non-timed) uniform consensus. We also investigate the maximum number of faulty processes that can be tolerated. We show that any Δ$\mathrm{\Delta }$-timed uniform consensus algorithm tolerating up to _ft$f_{\mathrm{t}}$ timing-faulty processes requires that the system has at least _ft+1$f_{\mathrm{t}}+1$ correct processes. This impossibility result implies that the proposed algorithm attains the maximum resilience about the number of faulty processes. We also show that any Δ$\mathrm{\Delta }$-timed uniform consensus algorithm tolerating up to _ft$f_{\mathrm{t}}$ timing-faulty processes cannot solve the (non-timed) uniform consensus when the system has less than _ft+1$f_{\mathrm{t}}+1$ non-crashed processes. This impossibility result implies that our algorithm attains the maximum adaptiveness.     

The curing behavior of resol. III. Effect of alkali metal hydroxides and alkaline earth metal hydroxides as catalyst for the cure of resol

The effect of the addition of cure catalysts on the cure acceleration of ammonia free resol was investigated by means of Curelastometer. The resol which was prepared by the reaction between phenol and formaldehyde with molar ratio 1:1.2 in the presence of NaOH (0.02 mol to phenol) was neutralized with HCI. Catalyst selected from LiOH, NaOH, KOH, Mg(OH)₂, Ca(OH)₂, Sr(OH)₂, and Ba(OH)₂ was added to the resol, and curing behavior of the resol was examined. Both alkali metal hydroxides and alkaline earth metal hydroxides accelerate the curing of resol. The cure acceleration effect of barium hydroxide is the largest. In the relation between the kinds of catalysts and the cure acceleration effect, the larger the ion radius of catalyst the faster the cure of resol. Cure speed of the resol containing either sodium hydroxide or barium hydroxide as a curing catalyst increases with an increase in the amount of catalyst. Apparent activation energies of curing behavior of the resols containing the cure catalysts were in the range 17.0–21.3 kcal/mol.     

Identification of angular and positional deviations inherent to 5-axis machining centers with a tilting-rotary table by simultaneous four-axis control movements

This paper describes a method for identifying the eight deviations inherent to five axis control machining centers by means of simultaneous four-axis control movements. Some methods to identify the deviations have been proposed. However, a simultaneous four-axis control technique using a ball bar instrument has not been applied to the measurement of relative displacements between the main spindle and the worktable. Furthermore, the method for assessing the deviations from the trajectories has not been proposed. Thus, in this paper, a calibration method based on the simultaneous four-axis control technique is proposed for five axis control machining centers with a tilting rotary table. To confirm the validity of the proposed method, simulations were conducted. The trajectories were obtained by means of a mathematical model into which the eight deviations were substituted. In the first step, four of the eight deviations were estimated by an observation equation for which two measurement trajectories and six reference ones were used. In the second step, the remaining four deviations were geometrically calculated using the values estimated by the observation equation. As a result, it was found that the proposed method was sufficient to identify the deviations accurately.     

Effect of Nitrate on Nodule and Root Growth of Soybean (Glycine max (L.) Merr.)

The application of combined nitrogen, especially nitrate, to soybean plants is known to strongly inhibit nodule formation, growth and nitrogen fixation. In the present study, we measured the effects of supplying 5 mM nitrate on the growth of nodules, primary root, and lateral roots under light at 28 °C or dark at 18 °C conditions. Photographs of the nodulated roots were periodically taken by a digital camera at 1-h intervals, and the size of the nodules was measured with newly developed computer software. Nodule growth was depressed approximately 7 h after the addition of nitrate under light conditions. The nodule growth rate under dark conditions was almost half that under light conditions, and nodule growth was further suppressed by the addition of 5 mM nitrate. Similar results were observed for the extending growth rate of the primary root as those for nodule growth supplied with 5 mM nitrate under light/dark conditions. In contrast, the growth of lateral roots was promoted by the addition of 5 mM nitrate. The 2D-PAGE profiles of nodule protein showed similar patterns between the 0 and 5 mM nitrate treatments, which suggested that metabolic integrity may be maintained with the 5 mM nitrate treatment. Further studies are required to confirm whether light or temperature condition may give the primary effect on the growth of nodules and roots.     

Hi-QIP工艺—一种新型的炼铁技术

Hi-QIP工艺(优质铁粒工艺)是一种新型的煤基生产优质铁粒的生产工艺.通过应用这种技术,在转底炉中能生产出熔融还原铁,而且,用这种方法进行生产时,没有对原材料混合物的质量波动提出要求.文章论述的是用这种方法所进行的中试场试验及结果.     

Crystalline structure of polyethylene containing vinylene units in the main chain

Polyethylene containing trans- or cis-vinylene units in the main chain has been synthesized by means of partial hydrogenation of trans- or cis-polypentenamer (TP or CP), and trans-polyoctenamer (TO). Crystalline structure of the polymers has been investigated with wide-angle X-ray diffraction, FT-IR analyses, solid-state NMR measurements and quantum chemical calculations of the NMR chemical shifts. These results clear that the partially hydrogenated TP or CP samples having an average number of methylene units of 6.9-8.4 per vinylene unit forms not only orthorhombic crystal but hexagonal-like crystal.     

A strategy for identifying static deviations in universal spindle head type multi-axis machining centers

This research was conducted in order to investigate the effectiveness of the checking method specified in ISO 10791-6 and to propose an additional method for identifying the geometric deviations inherent to five-axis machining centers with a universal spindle head. The specified method is not sufficient for assessing the influence of individual geometric deviations. Therefore, additional measurements are needed in order to use this checking method effectively. The spherical motion in the additional measurements is a modified version of the ISO standard. Some of the deviations are presumed based on the result of the additional measurements, and so the method of identifying the remainder of the geometric deviations was designed by analyzing the link geometry of the machine. The identification procedure consists of three steps. In the first and second steps, after performing two measurements, six out of ten deviations are identified by means of an observation equation. In the third step, four of the ten deviations are identified by means of the link geometry. The exactness of the proposed procedure for identifying the deviations inherent to the five-axis machine is confirmed through simulations.