LOCALIZATION OF OBJECT (SPINE) IN MEDICAL IMAGE USING ACTIVE SHAPE MODELS

Active shape models (ASM), consisting of a shape model and a local gray-level appearance model, can be used to locate the objects in images. In original ASM scheme, the model of object′s gray-level variations is based on the assumption of one-dimensional sampling and searching method. In this work a new way to model the gray-level appearance of the objects is explored, using a two-dimensional sampling and searching technique in a rectangular area around each landmark of object shape. The ASM based on this improvement is compared with the original ASM on an identical medical image set for task of spine localization. Experiments demonstrate that the method produces significantly fast, effective, accurate results for spine localization in medical images.

广州自行车轮滑极限中心工程施工新技术综述

广州自行车轮滑极限中心工程屋盖为单层椭圆球面钢网壳结构,通过采用定型柱模和可移动脚手架以加快立柱施工速度,采用扣件式钢管支架体系解决高大模板体系支模问题。通过流水段划分和施工分区加快施工进度。通过合理的吊装单元划分、现场分片拼装、相贯节点焊接、多点支撑环行行进的屋盖吊装工艺解决钢结构安装问题。屋面板安装采用直立锁边固定方式,在板肋设计反毛细凹槽,效果良好。完善而精致的赛道设计和施工是本工程的亮点。

Fixed-bed column study for deep removal of copper(Ⅱ) from simulated cobalt electrolyte using polystyrene-supported 2-aminomethylpyridine chelating resin

This study presents the deep removal of copper (Ⅱ) from the simulated cobalt electrolyte using fabricated polystyrene-supported 2-aminomethylpyridine chelating resin (PS-AMP) in a fixed-bed.The effects of bed height (7.0–14.0 cm),feed flow rate (4.5–9.0 mL/min),initial copper (Ⅱ) concentration of the feed (250–1000 mg/L),feed temperature (25–40 ℃) and the value of pH (2.0–4.0) on the adsorption process of the PS-AMP resin were investigated.The experimental data showed that the PS-AMP resin can deeply eliminate copper (Ⅱ) from the simulated cobalt electrolyte.The bed height,feed flow rate,initial copper (Ⅱ) concentration of the feed,feed temperature and feed pH value which corresponded to the highest removal of copper (Ⅱ) were 7.0 cm with 35 mm of the column diameter,4.5 mL/min,40℃,1000 mg/L and 4.0,respectively.The breakthrough capacity,the saturated capacity of the column and the mass ratio of Cu/Co (g/g) in the saturated resin were correspondingly 16.51 mg/g dry resin,61.72 mg/g dry resin and 37.67 under the optimal experimental conditions.The copper (Ⅱ) breakthrough curves were fitted by the empirical models of Thomas,Yoon-Nelson and Adam-Bohart,respectively.The Thomas model was found to be the most suitable one for predicting how the concentration of copper (Ⅱ) in the effluent changes with the adsorption time.

Valorization of natural diatomite mineral:Application to removal of anionic dye from aqueous solution in a batch and fixed-bed reactor

In this work,the efficiency of an adsorption process,in which Moroccan diatomite(ND)is used as a low-cost adsorbent to remove Congo red(CR)dye from contaminated waters in batch and column system,was examined.The influence of experimental conditions(pH,adsorbent dose and temperature)on the adsorption of CR onto the ND adsorbent was studied.A study of the adsorption kinetics for CR revealed that a pseudo-second-order model provided the best fit to the experimental kinetic data,and the equilibrium data were well described by the Langmuir isotherm model with an adsorption capacity of 6.07 mg/g using 15 g/L of ND,pH=6,contact time 3 h and 25℃.On the other hand,the ND regeneration tests were investigated and showed that the desorption reaches at least 50%when using ethanol as eluent.In addition,the adsorption process in a continuous mode was studied.Breakthrough curves were properly represented by the Yoon—Nelson model.Hence,the adsorption capacity of 5.71 mg/g was reached using 0.114 g of adsorbent,CR concentration of 6 mg/L and a flow of 1 mL/min under 25℃.

Stability analysis of the pillars between bedded salt cavern gas storages by cusp catastrophe model

The failure of pillars between bedded salt cavern gas storages can be seen as processes that the deformations of pillars convert from continuous gradual change system to catastrophe state,which are typical nonlinear catastrophe problems.In the paper,the cusp catastrophe model is proposed to obtain the stability factors of pillars.It can overcome the shortages of traditional strength reduction finite element method(SR FEM) and greatly improve the accuracy of stability factors obtained by numerical simulations.The influences of cavern depth,gas pressure,pillar width,and time on the stability factors are studied.Y-1 and Y-2 salt cavern gas storages,located at Jiangsu province of China,were simulated as examples.The stability factors of pillars between Y-1 and Y-2 were evaluated,and the running parameters were recommended to ensure the pillars stability.The results showed that the cusp catastrophe model has high practicability and can precisely predict the stability factors.The stability factors are equidirectional with the increase of gas pressure and pillar width,but reverse to the increase of cavern depth and time.The stability factors of pillars between Y-1 and Y-2 are small for narrow widths,which are influenced greatly by gas pressure,time,pressure difference,and gas production rate.In order to ensure the safety of pillars,the lowest gas pressure,safe running time,max.pressure difference and max.gas production rate of Y-1 and Y-2 were recommended as 7 MPa,5 years,3 MPa,and 0.50 MPa/d,respectively.