Optimal Design of Novel Electromagnetic-Ring Active Balancing Actuator with Radial Excitation

Imbalance vibration is a typical failure mode of rotational machines and has significant negative effects on the effii-ciency,accuracy,and service life of equipment.To automatically reduce the imbalance vibration during the opera-tional process,different types of active balancing actuators have been designed and widely applied in actual produc-tion.However,the existing electromagnetic-ring active balancing actuator is designed based on an axial excitation structure which can cause structural instability and has low electromagnetic driving efficiency.In this paper,a novel radial excitation structure and the working principle of an electromagnetic-ring active balancing actuator with a combined driving strategy are presented in detail.Then,based on a finite element model,the performance param-eters of the actuator are analyzed,and reasonable design parameters are obtained.Self-locking torque measurements and comparative static and dynamic experiments are performed to validate the self-locking torque and driving effi-ciency of the actuator.The results indicate that this novel active balancing actuator has sufficient self-locking torque,achieves normal step rotation at 2000 r/min,and reduces the driving voltage by 12.5％.The proposed novel balancing actuator using radial excitation and a combination of permanent magnets and soft-iron blocks has improved electro-magnetic efficiency and a more stable and compact structure.     

High-performance Pb(Ni1/3Nb2/3)O3-PbZrO3-PbTiO3 ceramics with the triple point composition

Ternary 0.552Pb(Ni_1/3Nb_2/3)O₃-xPbZrO₃-(0.448-x)PbTiO₃ (PNN-PZ-PT) ceramics near the triple point compositions were fabricated by an improved two-step sintering method. The triple point composition 0.552PNN-0.135PZ-0.313PT ceramic has outstanding piezoelectric performance with piezoelectric coefficient d₃₃ = 1200 pC/N. Its easy fabrication and low cost make this piezoelectric material an excellent candidate for high sensitivity sensors and ultrasonic transducers. The evolution of domain structures for ceramics with composition near the triple point provides deeper insight into the mechanism of ultrahigh piezoelectric properties of PNN-PZ-PT ceramics.     

三维激光扫描测量技术在矿山精矿盘点中的应用

采用三维激光扫描非接触倾斜测量法，可以高效获取矿仓中精矿产品的物料堆积形态。通过优化精矿盘点扫描测量流程，精准计算出矿仓库存量，提高了精矿盘点数据的准确性、测量的高效性和操作的安全性。     

Use of micellar extraction and cloud point preconcentration for valorization of saponins from sisal (Agave sisalana) waste

Sisal (Agave sisalana) is the main hard fiber produced worldwide, with an estimated generation of 400 thousands t in 2011. From its leaves, only the hard fibers, which represent 3–5% of their weight, are removed. The remaining 95–97% is referred to as sisal waste and contains steroidal saponins that can be potentially used in foods, cosmetics and pharmaceuticals formulations, as well as for soil bioremediation. The present work aimed at to evaluate strategies for the extraction and concentration of saponins from sisal waste, focused on the use of clean solvents, such as water and ethanol. For this purpose, it was firstly performed a central composite rotatable design for the optimization of the extraction conditions followed by a comparison of this strategy with other methods (Soxhlet, ultrasound-assisted extraction and micellar extraction). Cloud point preconcentration was then tested, using several types and concentrations of salts. The use of orbital shaker extraction (200 rpm) with an ethanolic solution (30%, v/v) at 50 °C, a mass/volume ratio sisal/solvent of 0.17 (g/mL) for 4 h allowed a recovery of 38.6% of the saponins. When a micellar extraction strategy using 7.5% (v/v) of Triton X-100, under the above-mentioned conditions was performed, saponins recovery raised to 98.4%. In a subsequent step, the addition of 20% (m/v) sodium carbonate led to a preconcentration factor of 20.3. The best adsorbent for Triton removal from the preconcentrated solution was Amberlite FPX-66. The process strategy proposed in the present study showed to be efficient for saponins extraction and preconcentration from a low-cost, highly available agricultural waste.     

The 9‐point hedonic scale and hedonic ranking in food science: some reappraisals and alternatives

The 9‐point hedonic scale has been used routinely in food science, the same way for 60 years. Now, with advances in technology, data from the scale are being used for more and more complex programs for statistical analysis and modeling. Accordingly, it is worth reconsidering the presentation protocols and the analyses associated with the scale, as well as some alternatives. How the brain generates numbers and the types of numbers it generates has relevance for the choice of measurement protocols. There are alternatives to the generally used serial monadic protocol, which can be more suitable. Traditionally, the ‘words’ on the 9‐point hedonic scale are reassigned as ‘numbers’, while other ‘9‐point hedonic scales’ are purely numerical; the two are not interchangeable. Parametric statistical analysis of scaling data is examined critically and alternatives discussed. The potential of a promising alternative to scaling itself, simple ranking with a hedonic R‐Index signal detection analysis, is explored in comparison with the 9‐point hedonic scale. © 2014 Society of Chemical Industry     

220t/h循环流化床锅炉温度测点布置及其仪表选型

结合某年产20万t乙二醇项目,分析220t/h高温高压低倍率循环流化床燃煤锅炉温度测点的布置。通过对比各种温度检测仪表的优、缺点,并分析温度测点处介质的特点,给出了安化220t/h循环流化床锅炉温度仪表的选型方案。     

Effect of Drying Temperature on Mechanical Properties of Dried Corn

The effect of drying air temperature on the mechanical properties of corn kernels was investigated. Corn was dried at drying temperatures of 40, 50, 60 and 70°C and air flow rate of 1.8 kg/min in a convective dryer. The kernels were then loaded uniaxially in a material testing machine at a loading rate of 3 mm/min, up to the rupture point. An increase in drying temperature from 40 to 70°C increased kernel deformation at the rupture point by an average of 12%. Moreover, values of force, stress, toughness, and modulus of elasticity of corn decreased on average by 21, 26, 36, and 38%, respectively.     

Role of activated carbon on micropollutans degradation by ionizing radiation

The objective of this study was to analyze the influence of the presence of activated carbon on the degradation of the triiodinated contrast medium diatrizoate (DTZ) by the simultaneous use of gamma radiation and activated carbon. Four commercial activated carbons (Ceca, Witco, Sorbo, and Merck) with different textural and chemical characteristics were used for this purpose. The percentage DTZ removal obtained was considerably higher with the gamma radiation/activated carbon (GM/AC) system than with radiolysis in the absence of activated carbon, and it depended on the specific activated carbon employed. First, we optimized the amount of activated carbon required to maximize the amount of DTZ removed by the GM/AC system (0.06 g). The degradation constants were higher with the GM/AC system than with radiolysis alone, evidencing a synergic effect that favors pollutant removal. This synergic effect is independent of the textural but not the chemical characteristics of the activated carbon, observing a higher synergic activity for carbons with a higher surface content of oxygen, specifically quinone groups. We also highlight that the synergic effect of the activated carbon requires adsorbent–adsorbate electrostatic interaction and is absent when this interaction is hindered.     

高熔点聚α-烯烃的合成

利用过渡金属催化剂,包括负载型Ziegler-Natta催化剂和均相茂金属催化剂,进行了系列α-烯烃的聚合,所得聚α-烯烃的熔点基本都高于200℃,个别样品高于300℃。单体结构强烈影响单体聚合转化率,在所选单体中,以烯丙基环己烷(ACH)转化率最高,3-甲基-1-丁烯(3M1B)转化率最低。同时进行了个别单体的共聚,所得聚合物熔点低于均聚物。