FLOW-INDUCED VIBRATION AND DAMAGE IN SIEVE-TRAY COLUMNS

Certain failures in absorption and distillation columns are attributed to flow induced vibrations. Mechanisms by which column pressure pulsations can occur are discussed. The mechanism most closely linked to the damage conditions is identified and its limits and characteristics defined. Interaction between the pulsation phenomenon and the mechanical damage is discussed.     

Psychometric procedures and the detection and exploration of behavioural deficits due to cerebral dysfunction in man: II.

There are basically two approaches to the use of psychometric tests in the detection of "brain damage": the first is centred around a view of regional equipotentiality of brain functioning and the second around a unitary view of brain functioning. The former was explored in an earlier paper in this journal (Rubino, 1970). The latter approach is explored here in terms of the utility of three well-known tests: the Bender Gestalt, the Benton Visual Retention Test, and the Graham Kendall Memory for Designs. The influence of such factors as age, diagnoses, hit-rates, etc., are briefly discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eye trigeminal sensitivity, tear film stability and conjunctival epithelium damage in 182 non-allergic, non-smoking Danes

The population distributions of CO(2)-induced irritation sensitivity in the eyes (COI), tear film stability (break-up time, BUT), and epithelium damage (ED) and the relation of these to basic potential confounders were assessed in an age- and gender-stratified random sample of citizens in Aarhus County, Denmark. One hundred eighty-two non-allergic, non-smoking persons participated. A general health questionnaire and an indoor air questionnaire was filled out before the measurements. The BUT was non-normally distributed, as was COI at 16% CO(2) and single ED-scores. However, COI average for all levels was normally distributed and the total score for ED was only marginally deviating. BUT decreased, the threshold to CO(2) increased, and irritation intensity at CO(2) eye exposure decreased with increasing age. ED was increased among women. There were no internal relations between the three measures, but reduced BUT was seen among subjects rating high levels of exposure to dust, electrostatic fields, and dry air. ED decreased by perceived unpleasant odors and increased with experiences of high temperatures. CO(2) sensitivity increased by perceived draught, dry air, and noise exposure prior to measurements. Selection bias cannot be excluded and the results may therefore not be truly representative of the general population. However, the results may be used as reference data for future use of measurements of break-up time, epithelium defects, and CO(2) sensitivity of the eyes in the indoor air. PRACTICAL IMPLICATIONS: The most direct implication is that results can be used as reference level for measurements in problem buildings and for individual measurements. The reference can also be used in research and the other results as basis for future hypotheses and for support of existing hypotheses.     

轮南油田注水井污染评价方法探讨

基于塔里木盆地轮南油田注入水对油藏污染的特点,定义注水井的实际注水量(Qt)与理论吸水量(Qf)之比为注水井吸水效率(α),根据α随注水时间(t)的变化所反映的地层污染的变化情况,将地层的污染程度分为无污染(α≥1.0)、轻微污染(0.9≤α<1)、一般污染(0.7≤α<0.9)和严重污染(0≤α<0.7)。α-t曲线可以反映不同注水时期注水井的地层污染状况,间接了解注水水质的变化情况;Qt-Qf图示法能直观反映较长注水时期内注水井的总体污染状况。与通常采用的"表皮系数"法(只能评价注水井在较短时间段内的污染状况,且获取参数成本高)相比,所提出的评价方法具有获取参数容易、分析简单、结果直观的优点,便于监测注水井注入水对地层的污染状况,及时发现注水井的水质问题。图3表3参5     

泵下锚定反洗技术

辽河油田地层压降快,供液能力差,部分井需要加深泵挂,但泵挂加深后,常规的泵上锚定和泵下反洗技术难以实现.针对这些情况,开展了泵下锚定反洗技术研究.研制了液压坐封GY241型锚定器和"自封与压缩胶筒"双重密封的ZY331型反洗封隔器.解决了深井中施工管柱热洗时的断脱问题,阻止了管柱的伸长与缩短,提高了泵效,防止了洗井液倒灌进地层造成油层污染.现场应用30井次,施工成功率100%,实现了深井泵下锚定与反洗技术的突破,具有良好的应用前景.     

Diagnostics of the Condition of the Flow-Through Part of High-Pressure and Intermediate-Pressure Cylinders by Running Measurements of Steam Pressure and Temperature in a Turbine

A method for diagnosing mechanical damage and wear of the blade system and the shroud, diaphragm, and end seals is presented. The method is based on the use of the readings of devices for scheduled control of the steam temperature and pressure at the outlet from the cylinders, in the extracted steam, and in the first shoulders of the end seals. Results of practical application of the method at electric power plants including those equipped with data-processing equipment are presented. The introduction of the suggested monitoring will make it possible to pass from scheduled repair to determining the repair time proceeding from the actual condition of the turbine.     

Damage Modeling of Notched Graphite/Epoxy Sandwich Panels in Compression

Open-hole honeycomb sandwich panels with woven graphite/epoxy facesheets and Nomex cores were tested uniaxially in compression to characterize their damage tolerance. A plain weave T-300 graphite fiber fabric was used for the facesheets in two stacking sequences: [45/0₂] and [0₃]. Observations of macroscopic sub-critical damage behavior were different in the two material systems. Linear damage zones (LDZ), consisting of fiber micro-buckles and extensive delamination, were typically observed in the [0₃] material. The [45/0₂] material exhibited a delamination/bulge zone (DBZ), which consisted of an out-of-plane curved deformation of the outer 45° ply accompanied by a delamination from the interior 0° plies. Modeling of these apparently distinct failure modes, and comparison to experimental data, revealed that the only mode representative of damage tolerant behavior is linear damage zone formation and propagation for both material systems, and that the delamination/bulge behavior is a secondary phenomenon.     

东北地区低温冷害年的环流特征及预测

采用中国东北三省5－9月≥10℃积温距平和水稻年景指数作为判断低温冷害年的因子,用聚类分析方法将1951－1995年划分成4类年型,选出19种对分类影响较大的环流特征量进行判别分析,得到很好的回判结果。使用几个严重低温冷害年的环流特征量,分析典型冷害年的主要环流特征,将所有环流特征量的年份加1年,再进行判别分析,选出18个环流特征量,预测下一年的年型,效果很好。     

汽轮机结构元件的损伤和寿命评估

提出了汽轮机转子在高应力疲劳与高温蠕变变互作用下的损伤本构模型与寿命评估方法,以及用于汽轮机转子结构分析的基本方程与变分原理,利用“间置加载”型荷载谱的特点,提出两个基本假设,并根据初始循环应力应变场对损过程中的循环应力应变场进行了有效描述,可对汽轮机转子结构寿命进行评估。     

Novel MMC microstructure with tailored distribution of the reinforcing phase

Saffil short fibre agglomerates with diameters of 0.4 mm to 1 mm have been prepared using a tumbling technique. These were packed and infiltrated with molten 6061 Al alloy to make a metal matrix composite (MMC) with a novel microstructure in which the composite spheres are randomly distributed in the fibre-free aluminium matrix. In parallel, a commercial preform made of identical Saffil alumina short fibres and having the same fibre volume faction was used to prepare a conventional MMC by the same technique. Microstructural observation indicates that, within the composite spheres, the local volume fraction of fibre decreases from the outer layer to the centre region.
The energy absorption during fracture was estimated by using a three point loading test on notched samples and was compared with that for conventional MMCs. Preliminary results suggest that this novel MMC possesses higher energy absorption capability and hence better damage tolerance. The fracture surfaces were examined by scanning electron microscopy in order to inform these experimental results.