INFLUENCE OF PULP PULSATION ON THE BATCH FLOTATION OF GALENA

An experimental investigation into the effect of pulp pulsation on the flotation of an artificial mixture of galena and quartz has been conducted. Laboratory experiments have shown that the recovery and kinetics of lead flotation can be improved significantly by pulsating the pulp, while the grade and selectivity of the lead remained virtually unchanged. Pulsation of the pulp led to structural change of bubbles. An increase in the number of bubbles and a decrease in the bubble size resulted in an increase in the gas holdup in the pulp and a likely increase in the bubble-particle collision rate. Likewise, the viscosity of the slurry could be decreased by means of pulp vibration, enhancing mass transfer between the slurry phase and froth phase. At the same time, the energy input by pulp pulsation could help to lower the energy barrier for bubble-particle attachment by lowering the induction time of the attachment. In addition, non-selectively attached particles could be stripped off the bubble surface by the inertial forces acting on the particles during pulsation of the pulp. Image analysis of the froth showed that pulsation resulted in a more stable froth, with more numerous, smaller bubbles with higher loadings.     

Accelerating Mobile Video: A 64-Bit SIMD Architecture for Handheld Applications

Providing quality mobile video applications in hand-held mobile devices requires increased computational capability. Using Single Instruction Multiple Data (SIMD) techniques to expose and accelerate the data parallelism inherent in video processing increases performance in handheld and wireless systems. The paper introduces a new 64-bit SIMD coprocessor of the Intel® XScale® microarchitecture which is optimized for low-power handheld applications. The architecture blends the SIMD media processing style with the capabilities of the XScale microarchitecture. This paper provides an overview of the architecture, its instruction set, programming model, the pipeline organization and functional units. The paper also describes how key features of architecture improve the performance of video applications as compared to a scalar implementation. The performance and power improvements based upon measured results are analyzed to show how the opportunities of power savings by reducing the frequency and voltage can be realized.Nigel C. Paver has 13 years experience with the ARM architecture, and in the Intel PCA Components group in Austin, Texas, he is responsible for the architecture and implementation of multimedia coprocessors for the Intel XScale micro-architecture. He is also involved in product architecture and definition of Intel PCA processors. Before Intel, Nigel was one of the lead designers of the early AMULET asynchronous ARM microprocessors at the University of Manchester. He was also vice president in a startup company which used asynchronous design techniques to produce a low-power asynchronous DSP core. Nigel holds a Master of Science degree and Ph.D. in computer science from the University of Manchester and a Bachelor of Science degree in electronics from UMIST.Moinul Khan is a multimedia product architect at Intel Corporation PCA Components group. He is responsible PCA graphics and security architecture. His research interests are virtual prototyping, signal processing algorithms and architecture and communications networking. Before joining Intel he was a technology specialist and founding member of a startup at ATDC, Georgia. He worked on his doctoral research at Georgia Center for Advanced Telecommunications Technology at Georgia Institute of Technology. He received his B.Tech form Indian Insti-ture of Technology and MSEE from Georgia Tech. He also worked as a research member for Canadian Institute for Telecommunications Research and Bell Communications Laboratories.Bradley C. Aldrich joined Intel in 1997 where he is currently an architect within the PCA Components Group. His current work includes the development of coprocessor instruction support in addition to image capture and display technologies for XScale based application processors. He was previously a member of the Intel/Analog Devices joint development architecture team responsible for video enhancements for the Micro Signal Architecture. Prior to that he was a video system architect in Intel’s Digital Imaging and Video Division working on CMOS sensors, still cameras, and tethered PC based video peripherals. He has also worked as a device engineer for Motorola and as a test engineer for Tektronix. He received a BSEE in 1988 and MSEE in 1994 from the University of Texas at San Antonio.Christopher D. Emmons received a Bachelor of Science degree in Computer Science from the University of Texas at Austin in 2003. He joined Intel in 2001 and is currently a multimedia architect responsible for algorithm development and performance optimization for handheld products within the PCA Components Group. Prior to this he worked as an applications engineer providing performance and power analysis in support of product marketing groups. His research interests include video compression, operating system design, and dynamic resource management.     

一种新的字符提取和组合算法

工程图纸的扫描转换处理是ＣＡＤ／ＣＡＭ领域亟待解决的一个重要难题。图纸中通常包含了大量的字符，用以表示尺寸等信息，其处理方式完全不同于其他线型，提取并识别这些字符，是图纸处理中的关键组成部分。本文分析了现有的字符提取方法的不足，详细描述了一个新的提取算法，并且给出了算法在图纸扫描转换中的一个实例。该算法具有快速、高效和可靠的特点。     

简单多边形分解成凸多边形差组合的算法

本文说明一种把简单多边形分斛成凸多边形的差形式的组合的算法。该算法在求一简单多边形凸包的同时求出凸包和原多边形的差(把差称为内多边形),再对内多边形递归地作同样计算便可得到最终结果。最后证明了运算法的时间复杂性为O(N~2),其中N为原多边形的边数。     

A developmental study of novH gene expression in human central nervous system

The expression pattern of the human nephroblastoma overexpressed (novH) gene in the fetal human central nervous system was examined by in situ hybridization using digoxigenin-labeled novH-specific riboprobes. In the spinal cord, the nov-expressing neurons were first detected both in the ventral region at 16 weeks of gestation (G16W) and in the dorsal region at G38W. In the medulla, nov-expressing neurons were detected in the principal nucleus of the inferior olive, the hypoglossal nucleus and the dorsal motor nucleus of vagus at G16W. Nov-positive neurons were detected at G28W in the nucleus of the spinal tract of the trigeminal and cuneate nucleus, and at G38W in the abducens nucleus of pons, the red nucleus and the substantia nigra of the midbrain, the ventral posterolateral and the mediodorsal thalamic nucleus. A strong labeling was also detected in the striatum of the cerebrum and the cerebral cortex of the parietal lobe. These data established that novH is mainly expressed in somato-motor neurons in the lower central nervous system at early developmental stages and in the higher central nervous system at later stages, suggesting that nov may play an important role in neuronal differentiation.     

Impaired chemical coupling of cerebral blood flow is compatible with intact neurological outcome in neonates with perinatal risk factors

To develop chelating molecules that provide 99mTc-labeled polypeptides of high in vivo stability and high specific activities under mild reaction conditions, an asymmetrical bis(benzohydroxamamide) compound with an amine group, 4'-aminomethyl-N,N'-trimethylenedibenzohydroxamamide [NH2-C3(BHam)2], was designed and synthesized. The amine residue of NH2-C3(BHam)2 was converted to a maleimide group by reaction with N-succinimidyl-6-maleimidohexanoate, and the conjugation product was coupled to thiol groups of a monoclonal antibody against osteogenic sarcoma (OST7, IgG1) pretreated with 2-iminothiolane to prepare C3(BHam)2-OST7. 99mTc radiolabeling of C3(BHam)2-OST7 was performed by the exchange reaction with [99mTc]glucoheptonate. [99mTc]C3(BHam)2-OST7 was further characterized using directly radioiodinated OST7 ([125I]OST7) and [111In]labeled OST7 with 1-[4-[(5-maleimidopentyl)amidobenzyl]ethylenediamine-N,N, N'N'-tetraacetic acid (EMCS-Bz-EDTA) as references. [99mTc]C3(BHam)2-OST7 was obtained with radiochemical yields of over 94% at protein concentrations as low as 0.2 mg/mL at room temperature for 1 h. [99mTc]C3(BHam)2-OST7 remained stable after incubation in freshly prepared murine plasma and in the presence of cysteine. Similar binding affinities to tumor cells were observed between [99mTc]C3(BHam)2-OST7 and [125I]OST7. When injected into normal mice, [99mTc]C3(BHam)2-OST7 exhibited radioactivity levels in the blood similar to [111In]-EMCS-Bz-EDTA-OST7 up to 24 h postinjection with significantly faster elimination rate of the radioactivity from the liver. In nude mice bearing osteogenic sarcoma, no significant differences were observed in the radioactivity levels in the blood and the tumor between [99mTc]C3(BHam)2-OST7 and [125I]OST7 at 24 h postinjection. These findings indicated that C3(BHam)2 provided 99mTc chelate of high stability at low concentrations even when conjugated to an intact antibody. Such characteristics render bis(hydroxamamide) compounds useful as chelating molecules for preparation of 99mTc-labeled polypeptides.     

Effect of milk replacer program on digestion of nutrients in dairy calves

There are concerns with feeding young dairy calves amounts of milk solids approaching 0.9 kg of dry matter (DM) or more because of slumps in average daily gain (ADG) at weaning and low starter intakes. Additionally, programs feeding more than 0.6 kg of DM have not been thoroughly tested for success at different weaning ages. Four milk replacer (MR) programs were compared in trial 1. Program A was 0.44 kg of DM of a 21% crude protein (CP), 21% fat MR powder fed daily for 42 d. Program B was 0.66 kg of DM of a 27% CP, 17% fat MR powder fed daily for 42 d. Program C was 0.66 kg of DM of a 27% CP, 17% fat MR powder daily fed for 28 d. Program D was up to 1.09 kg of DM of a 29% CP, 21% fat MR daily fed for 49 d. Digestibility estimates were made and blood was sampled for serum constituents on d 53 to 56, and performance was measured for 84 d. Three programs feeding a 27% CP, 17% fat MR powder were compared in trial 2 over 56 d. Calves on program A were fed 0.66 kg of DM powder daily and weaned at 28 d. Calves on program B were fed 0.66 kg of DM powder daily and weaned at 42 d. Calves on program C were fed up to 1.09 kg of DM powder daily and weaned at 42 d. Digestibility estimates were made and blood was sampled for serum constituents d 21 to 24, d 36 to 39, and d 53 to 56. In trial 1, calves fed program A had the least overall ADG. Calves fed program D had the greatest ADG from 0 to 56 d, the least ADG from d 56 to 84, the least digestibility estimates, and the least concentrations of serum amylase. At 84 d, there were no differences in body weights of calves fed programs B, C, and D. In trial 2, calves fed program A had the greatest starter intake and greatest concentrations of serum amylase. Calves fed program C had the least estimates of digestibility from d 53 to 56 and the least serum concentrations of amylase. Calves fed up to 1.09 kg/d of 27 to 29% MR powders and weaned at 42 or 49 d had lower starter intakes, concentrations of serum amylase, and digestion of starter postweaning compared with calves fed conventional 21% CP, 21% fat MR powders fed at 0.44 kg/d. Calves fed 0.66 kg/d of a 27% CP, 17% fat MR powder and weaned at 28 or 42 d of age had no reductions in intake or digestion compared with calves fed conventional MR and gained as much total body weight from 0 to 84 d as calves stepped up to 1.09 kg of MR.     

Testing the “new associations” biological control concept with a tachinid parasitoid (Euclytia flava)

Males of the spined soldier bug,Podisus maculiventris (Heteroptera: Pentatomidae), produce an attractant pheromone that is exploited as a host-finding kairomone by a complex of parasitic species. The capability to catch hundreds of a generalist tachinid fly parasitoid,Euclytia flava, alive in traps baited with the pheromone ofP. maculiventris provided an opportunity to test the premise of the new associations biological control concept. The hypothesis that host species newly associated with a parasitoid are maladapted relative to native-native associations was tested by givingE. flava females a choice between native and exotic stink bugs (Heteroptera: Pentatomidae). WildE. flava females preferred to oviposit on exotic pentatomid species rather than indigenous, known host species, both in field traps baited with the pheromone of a native host and in the laboratory. Data presented here demonstrate that an invader may be vulnerable to native parasitoids in one aspect of the parasitism process (acceptance), yet go unrecognized as a potential host.     

Detecting changes in the operational states of hydrocyclones

In this investigation, video recordings of the underflow discharge of a pilot plant hydrocyclone were collected during classification of different precious metal ores. The underflow shape was monitored by determining the underflow width along a horizontal line through the image. This was accomplished by employing various noise reduction methods and identifying the flow boundaries via motion analysis. Subsequent monitoring of dilute, transitional and dense flow could be automated by embedding the underflow width measurements and making use of one-class support vector machines to estimate the distributional densities of the data in the resultant phase space. Experimental results suggest that the approach could provide a practical and inexpensive means of monitoring the operational states of hydrocyclones.