Characterisation of buildup in an electric furnace for smelting copper concentrate

The results from a characterisation of buildup in an electric smelting furnace for treating copperrich feed material at the Boliden Ronnskar smelter in Sweden are presented. The aim of the work was to obtain better knowledge about the mechanisms behind the formation of the buildup. Samples from the buildup were taken during the rebuilding of the furnace. The samples were characterised using chemical and mineralogical techniques. The buildup consists mainly of different phases such as spinel, matte, olivine and metalloids and has a complex and varying mineralogy, which indicates that the buildup is not formed under equilibrium conditions.     

国内外钢包的粘渣及其对策

阐述了国内外钢外的粘渣状况及减轻粘渣的措施，并通过分析概括，提出了钢包粘渣的主要原因和减轻粘渣的对策。     

2~#闪速炉水套及冷却水管在线化学清洗

针对熔炼车间二系统2#闪速炉内铜水套和炉体周围冷却水管道腐蚀结垢严重的现象,提出了有效的除垢方法,保证了2#闪速炉的正常运转。     

Proactive interference and the dynamics of free recall.

Proactive interference (PI) has long been recognized as a major cause of forgetting. Two experiments were conducted that offer another look at the subject by providing a detailed analysis of recall latency distributions during the buildup of and release from PI. These functions were accurately characterized by the convolution of the normal and exponential distributions (viz., the ex-Gaussian), which previously has been shown to describe recognition latency distributions. Further, the fits revealed that the increase in recall latency associated with the buildup of PI results from a slowing of the exponential retrieval stage only. The same result was found even when a short retention interval was used (and recall probability remained constant). These findings suggest that free-recall latency may be a sensitive index of the increased search set size that has often been assumed to accompany the buildup of PI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The combination of photocatalysis and ozonolysis as a new approach for cleaning 2,4-dichlorophenoxyaceticacid polluted water

Treatment of 2,4-D polluted waters with photocatalysis leads to the buildup of high concentrations of the long living intermediate 2,4-DCP. A new approach using a combination of ozonolysis and photocatalysis gave better degradation results with lower intermediate concentrations. The advantages of photocatalysis giving a constant decline in TOC and of ozonolysis giving no buildup of high intermediate concentrations were combined. Degradation data of 2,4-D for photocatalysis, ozonolysis and the combination of both for different pH ranges are given. Data on the main intermediate 2,4-DCP are given for the three different approaches.     

Estimating Pollutant Mass Accumulation on Highways during Dry Periods

For determining the accumulated pollutant mass on highways, two years of monitoring data were used from eight highway sites in southern California. Buildup over antecedent dry days was calculated from mass washed off from the following storm and retained pollutant mass. Mass accumulation rates were determined for total suspended solids (TSS), chemical oxygen demand (COD), oil and grease, total Kjeldahl nitrogen, and total phosphorus, and are reported in g/m2-day. A revised buildup model is proposed using an alternative modeling approach to describe buildup during dry days between storms. The result shows that, between 1 and 10 antecedent dry days, the pollutant mass buildup rates are determined to be 0.544?g/m2-day for TSS, 0.114?g/m2-day for COD, and 0.0113?g/m2-day for oil and grease. Buildup rates decline in subsequent periods rates decreased by 79% for TSS, 78% for COD, and 61% less for oil and grease in the following 10–70?day period.     

Densification of porous powder preforms during hot forging. I. Processing lubricant for transverse hot forging

Conclusions Use of lubricants 2, 3, 4 and 5 (Table 1) in transverse hot densification does not prevent buildup formation on the tool. By contrast, the specially developed molybdenum disulfide and graphite base lubricant 1 [13] exhibits excellent friction- and wear-reducing characteristics. With this lubricant it is possible to produce high-density P/M parts of considerable length by transverse hot forging without buildup formation on the tool and with little nonuniformity of deformation in the surface layers of the material.Translated from Poroshkovaya Metallurgiya, No. 1(289), pp. 22–25, January, 1987.     

Echo suppression and discrimination suppression aspects of the precedence effect

The precedence effect is a phenomenon that may occur when a sound from one direction (the lead) is followed within a few milliseconds by the same or a similar sound from another direction (the lag, or the echo). Typically, the lag sound is not heard as a separate event, and changes in the lag sound's direction cannot be discriminated. The hypothesis is proposed in this study that these two aspects of precedence (echo suppression and discrimination suppression) are at least partially independent phenomena. Two experiments were conducted in which pairs of noise bursts were presented to subjects from two loudspeakers in the horizontal plane to simulate a lead sound and a lag sound (the echo). Echo suppression threshold was measured as the minimum echo delay at which subjects reported hearing two sounds rather than one sound; discrimination suppression threshold was measured as the minimum echo delay at which subjects could reliably discriminate between two positions of the echo. In Experiment 1, it was found that echo suppression threshold was the same as discrimination suppression threshold when measured with a single burst pair (average 5.4 msec). However, when measured after presentation of a train of burst pairs (a condition that may produce "buildup of suppression"), discrimination suppression threshold increased to 10.4 msec, while echo suppression threshold increased to 26.4 msec. The greater buildup of echo suppression than of discrimination suppression indicates that the two phenomena are distinct under buildup conditions and may be the reflection of different underlying mechanisms. Experiment 2 investigated the effect of the directional properties of the lead and lag sounds on discrimination suppression and echo suppression. There was no consistent effect of the spatial separation between lead and lag sources on discrimination suppression or echo suppression, nor was there any consistent difference between the two types of thresholds (overall average threshold was 5.9 msec). The negative result in Experiment 2 may have been due to the measurements being obtained only for single-stimulus conditions and not for buildup conditions that may involve more central processing by the auditory system.     

Adaptation reveals multiple levels of representation in auditory stream segregation.

When presented with alternating low and high tones, listeners are more likely to perceive 2 separate streams of tones (“streaming”) than a single coherent stream when the frequency separation (Δ?) between tones is greater and the number of tone presentations is greater (“buildup”). However, the same large-Δ? sequence reduces streaming for subsequent patterns presented after a gap of up to several seconds. Buildup occurs at a level of neural representation with sharp frequency tuning. The authors used adaptation to demonstrate that the contextual effect of prior Δ? arose from a representation with broad frequency tuning, unlike buildup. Separate adaptation did not occur in a representation of Δ? independent of frequency range, suggesting that any frequency-shift detectors undergoing adaptation are also frequency specific. A separate effect of prior perception was observed, dissociating stimulus-related (i.e., Δ?) and perception-related (i.e., 1 stream vs. 2 streams) adaptation. Viewing a visual analogue to auditory streaming had no effect on subsequent perception of streaming, suggesting adaptation in auditory-specific brain circuits. These results, along with previous findings on buildup, suggest that processing in at least 3 levels of auditory neural representation underlies segregation and formation of auditory streams. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

IEGT-电力半导体器件在安钢炉卷轧机的应用

介绍了注入增强栅晶体管IEGT的基本工作原理、工作特性、横向比较,以及其在安钢120t转炉炉卷轧机上的应用和效果.     

Planar imaging quantification using 3D attenuation correction data and Monte Carlo simulated buildup factors

A new method to correct for attenuation and the buildup of scatter in planar imaging quantification is presented. The method is based on the combined use of 3D density information provided by computed tomography to correct for attenuation and the application of Monte Carlo simulated buildup factors to correct for buildup in the projection pixels. CT and nuclear medicine images were obtained for a purpose-built nonhomogeneous phantom that models the human anatomy in the thoracic and abdominal regions. The CT transverse slices of the phantom were converted to a set of consecutive density maps. An algorithm was developed that projects the 3D information contained in the set of density maps to create opposing pairs of accurate 2D correction maps that were subsequently applied to planar images acquired from a dual-head gamma camera. A comparison of results obtained by the new method and the geometric mean approach based on published techniques is presented for some of the source arrangements used. Excellent results were obtained for various source-phantom configurations used to evaluate the method. Activity quantification of a line source at most locations in the nonhomogeneous phantom produced errors of less than 2%. Additionally, knowledge of the actual source depth is not required for accurate activity quantification. Quantification of volume sources placed in foam, Perspex and aluminium produced errors of less than 7% for the abdominal and thoracic configurations of the phantom.     

攀钢镀锌机组连续退火炉在线控制系统

针对攀钢现有的自动化控制模式,开发出一种在线优化二级控制系统（L2）。介绍了L2系统的组成及其功能。系统在线投入后运行稳定,各项生产技术指标得到了系统的优化,极大地减少了生产过程中生产参数的人工输入。     

Ejaculatory duct obstruction

The diagnosis, long-range pathophysiology and surgical approach to ejaculatory duct obstruction are presented. Of 5 cases 3 had epididymal extravasation from long-term pressure buildup and secondary epididymal obstruction. This is similar to the epididymal findings after long-term vasectomy.     

Masonry Cladding Stress Failures in Older Buildings

Cracked and crumbling masonry cladding on older buildings in the urban environment is often clearly evident with just casual observations. Aside from the potential hazard of unstable masonry over busy city sidewalks, cladding distress leads to the accelerating decay of underlying wall elements. In order to effectively treat deteriorating masonry cladding, a clear understanding of the fundamental causes of failure is necessary. Much of this cladding trouble is caused by stress buildup due to an interaction between the massive exterior masonry walls and the interlaced structural frame, a design common to tall buildings constructed in the early 1900s. This paper reviews the mechanism of masonry cladding stress buildup in these older structures and some remedial measures which have proven effective.     

论湘钢二烧2~# 90m~2烧结机的工艺技术创新

湘钢二烧 2 #90 m2 烧结机的建设达到了理想的预期目标。本文仅就其机组的工艺技术创新进行了总结和论述     

Buildup and release from proactive interference in a rhesus monkey.

The potential of the buildup and release from proactive interference (PI) technique in the study of animal categorization was demonstrated with a rhesus monkey. A serial probe recognition task was used with a list of 4 consecutive slide pictures (upper screen) followed by a single probe picture (lower screen). The monkey moved a lever to indicate whether or not the probe was contained in the list. PI built over 40 consecutive trials tested with either flowers or primate faces. PI was released on category change and then built during 40 trials with the second category. The first 2 serial positions showed somewhat greater PI buildup and release, supporting conclusions from human studies that the effects occur primarily in secondary memory. A second experiment provided 2 replications of the main effect and showed through color border changes and elimination of color differences that color was not a critical feature. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Understanding the bottom buildup in an electric copper smelting furnace by thermodynamic calculations

Thermodynamic calculations were used to investigate the liquidus temperature of the slag and the possible influence on the buildup formation in an electric copper smelting furnace. The impact of parameters such as Fe/SiO₂ ratio, partial pressure of oxygen and the content of the oxides ZnO, Al₂O₃ and Cr₂O₃ in the slag were investigated with respect to the liquidus temperature of the slag. Results show that the chromium content in the slag has the greatest impact on the liquidus temperature and on the formation of solid particles. The characterisation of the buildup done earlier showed that spinel phases were among the dominating phases. This is supported by the thermodynamic calculations in the present paper, where the chromite solid solution was found to be the primary precipitation phase.     

Driven by information: A tectonic theory of Stroop effects.

The goal of avoiding distraction (e.g., ignoring words when naming their print colors in a Stroop task) is opposed intrinsically by the penchant to process conspicuous and correlated characteristics of the environment (e.g., noticing trial-to-trial associations between the colors and the words). To reconcile these opposing forces, the authors propose a tectonic theory of selective attention in which 2 memory-based structures--dimensional imbalance and dimensional uncertainty--drive selection by processing salient, surprising, and/or correlated information contained within and across stimulus dimensions. Each structure modulates the buildup of excitation to targets and the buildup of inhibition to distractors and to memories of previous stimuli. Tectonic theory is implemented to simulate the impact of 4 types of context on the presence, magnitude, and direction of congruity effects and task effects in the Stroop paradigm. The tectonic model is shown to surpass other formal models in explaining the range and diversity of Stroop effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of the reducing-gas distribution in the tuyere belt on the buildup in midrex furnaces

The influence of the reducing-gas distribution in Midrex furnaces is investigated. The temperature of the tuyere belt in the furnace lining is studied experimentally, and blockage of the tuyeres by buildup is analyzed. The tuyeres are mainly blocked on account of the nonuniform reducing-gas distribution, which is associated with the temperature gradient over the length of the tuyere belt.     

Environmental and hold time effects on fatigue of low-tin lead-based solder

The effect of environment on the strain-controlled fatigue resistance of a high-lead-low-tin solder was determined by comparing results in vacuum to those in air (wet and dry) and CO₂ (wet and dry). At low strain amplitude, air and CO₂ were shown to reduce the cycles to failure defined on the basis of the decrease in maximum cycle stress. The effect increases as the strain amplitude is reduced. Water vapor had little effect. Previously, the Coffin-Manson (C-M) relation was shown to fail for tests in air. The amount of failure is less in vacuum. The main fatigue failure mode is grain-boundary (GB) cracking, and this is accelerated by air or CO₂. Auger spectroscopy showed that there is tin buildup near the surface during fatigue in air or CO₂. The more rapid GB fracture was attributed to tin oxide (or tin oxide-lead oxide solid solution) buildup in the GB, where diffusion is more rapid. Formerly Research Assistant, Northwestern University