Effect of complexation of oxidised corn starch with mineral elements on physicochemical properties

The objective of this study was to determine the effect of complexation of oxidised starch with mineral elements on its physicochemical properties. Corn starch was oxidised with sodium hypochlorite and, afterwards, modified with ions of potassium, magnesium and iron. Thus, native and modified starches were analysed for: contents of mineral elements, colour parameters (L*a*b*), water binding capacity and solubility in water at temperature of 60 and 80 °C. Thermodynamic characteristics of gelatinisation by DSC, molecular weight distribution by GPC, intrinsic viscosity and pasting properties by RVA were studied. The efficiency of incorporation of metal ions into oxidised corn starch was about 30%, 20% and 20% for potassium, magnesium and iron ions, respectively. The complexation with potassium ions caused the greatest changes in the molecular weight distribution and the intrinsic viscosity of starches and viscosity of starch pastes. Only modification of starch with iron ions affected the colour parameters of the starch. Incorporation of metal ions into starch resulted also in changes in its water binding capacity and solubility in water.     

Remote Steering of Self‐Propelling Microcircuits by Modulated Electric Field

The principles and design of “active” self‐propelling particles that can convert energy, move directionally on their own, and perform a certain function is an emerging multidisciplinary research field, with high potential for future technologies. A simple and effective technique is presented for on‐demand steering of self‐propelling microdiodes that move electroosmotically on water surface, while supplied with energy by an external alternating (AC) field. It is demonstrated how one can control remotely the direction of diode locomotion by electronically modifying the applied AC signal. The swimming diodes change their direction of motion when a wave asymmetry (equivalent to a DC offset) is introduced into the signal. The data analysis shows that the ability to control and reverse the direction of motion is a result of the electrostatic torque between the asymmetrically polarized diodes and the ionic charges redistributed in the vessel. This novel principle of electrical signal‐coded steering of active functional devices, such as diodes and microcircuits, can find applications in motile sensors, MEMs, and microrobotics.     

Chemically modified organic/inorganic nanoporous composite particles for the adsorption of reactive black 5 from aqueous solution

In the present work, we report a chemically modified polyacrylamide/silica nanoporous composite adsorbent for the removal of reactive black 5 (RB5) azo dye from aqueous solutions. The composite adsorbent was synthesized in a packed bed and modified by ethylenediamine (EDA). The adsorbent was characterized by Fourier transformation infrared (FT-IR), thermogravimetric analysis (TGA), thermoporometry, Brunauer, Emmett and Teller (BET) method and scanning electron microscopy (SEM). Mechanical stability of the adsorbent was examined in a packed bed by following the back-pressure of the column. Pore diameter of the composite adsorbent in dry and wet states was estimated to be about 18.71 nm and 12.61 nm, respectively. Adsorption experiments were performed in batch mode and effect of various operational parameters on the adsorption capability of the adsorbent was studied systematically. The maximum adsorption capacity of the modified composites was found to be 454.5 mg RB5/g of adsorbent. The equilibrium data were analyzed by Langmuir, Freundlich, Sips, BET and Redlich–Peterson isotherm models and found to fit well to the BET isotherm. The data kinetically followed the pseudo-second-order model. High adsorption capacity, fast removal mechanism, and good mechanical stability are three advantages of the presented composite for the removal of RB5.     

Using laser ablation inductively coupled plasma mass spectroscopy (LA-ICP-MS) to determine the provenance of the cobalt pigment of Qinghua porcelain from Jingdezhen in Yuan Dynasty of China (1271–1368AD)

The provenance of cobalt mineral of the blue decoration in Yuan Qinghua porcelain would reveal the technological and cultural interaction between ancient China and the Islamic world. However, the limitation of conventional methods in the determining trace elements of the blue decoration hampered the deep research on provenance of the cobalt mineral. In the paper, we employed the good advantage of Laser-ablation-inductively-coupled-plasma-mass-spectroscopy (LA-ICP-MS) to determine the major element and trace elements of blue decoration of the different type of Qinghua successfully. The blue decoration of all different types of samples shared the same characteristics of higher FeO and lower Mn, which suggested the potter adopted the non-native cobalt material of China to paint the Yuan Qinghua in Jingdezheng, and the difference on the outside appearance of blue decoration of different samples were supposed to be related to the tenor of ore, the different treatment process of cobalt material and the firing process in the kiln. In addition, the significant differences on the element concentrations of Cu, Ni, Pb, Zr and Sb in the blue decoration between Yuan Qinghua and the Islamic blue and white wares of 13–14th century provided a new evidence to discuss the provenance of the cobalt of Yuan Qinghua porcelain.     

Preparation and characterisation of an easily absorbabl Mg‐casein hydrolysate complex produced through enzymatic hydrolysis and ultrafiltration

In this study, we synthesised a Mg‐casein hydrolysate complex that allowed the effective absorption of Mg. The type of enzyme (papain, alcalase 2.4 L, pepsin, trypsin) and the enzyme/substrate ratio for casein hydrolysis was optimised. When the enzyme/substrate ratio was 30%, the alcalase 2.4 L‐hydrolysate showed the highest Mg‐chelation efficiency, of 96.1%. To characterise and enhance the function of casein hydrolysate, we fractionated the casein hydrolysate according to molecular weight using ultrafiltration. The Mg‐chelation efficiency was increased with the decrease in the molecular‐weight range of the hydrolysate fractions. The smallest casein hydrolysate (fraction 5, 1 kDa<) is used for preparation of Mg‐casein hydrolysate complex. Synthesised Mg‐casein hydrolysate complex (fraction 5) exhibited 100% Mg solubility and 39.5% Mg bioavailability. These results indicated that the Mg‐casein hydrolysate remained a stable chelate during simulated gastro‐intestinal digestion in vitro. The Mg‐casein hydrolysate complex exhibited excellent antioxidant activity as well as Mg binding.     

Cathode plasma electrolytic deposition of Al2O3 coatings doped with SiC particles

Semiconductor particles doped Al₂O₃ coatings were prepared by cathode plasma electrolytic deposition in Al(NO₃)₃ electrolyte dispersed with SiC micro- and nano-particles (average particle sizes of 0.5–1.7?µm and 40?nm respectively). The effects of the concentrations and particle sizes of the SiC on the microstructures and tribological performances of the composite coatings were studied. In comparison with the case of dispersing with SiC microparticles, the dispersion of SiC nanoparticles in the coatings was more uniform. When the concentration of SiC nanoparticles was 5?g/L, the surface roughness of the composite coating was reduced by 63%, compared with that of the unmodified coating. Friction results demonstrated that the addition of 5?g/L SiC nanoparticles reduced the friction coefficient from 0.60 to 0.38 and decreased the wear volume under dry friction. The current density and bath voltage were measured to analyze the effects of SiC particles on the deposition process. The results showed that the SiC particles could alter the electrical behavior of the coatings during the deposition process, weaken the bombardment of the plasma, and improve the structures of the coatings.     

高炉灰中未燃煤粉含量检测方法研究

为提高高炉灰中未燃煤粉含量的检测效率及准确性,提出了一种矿相分析和化学成分分析相结合的新型检测方法。该方法利用研磨样代替镶嵌样,并用高炉灰化学成分分析对矿相分析进行验证。结果表明:铁与未燃煤粉含量的检测结果标准差分别为1.01%和0.62%,小于统计学的规定要求,说明该新型检测方法准确性良好。     

探究地质矿产勘查风险原因的分析及应对对策

我国有许多种类的地质矿产资源,地质矿产资源的勘查与开发有效地促进了我国工业生产的进步。整个社会的发展对于地质矿产资源的需求也非常高,所以必须开展高效的矿产资源勘查活动。但是目前地质矿产资源勘查中经常会存在一系列的风险,会对勘查人员及整个矿床造成不同程度的损害。相关企业必须采取有效的应对策略,有效降低企业的勘查风险。本文主要是基于地质矿产勘查风险原因的分析及应对策略两方面来展开进一步论述的。     

常用物探法在矿产资源勘探中的应用

随着经济社会的不断发展,井下的多种矿产资源引起了人们的广泛重视。然而由于可开发的地质资源埋藏较深,开采难度非常大,为了有效减少成本投入,避免投资风险,在能源开发过程中,应用物探方法进行勘查是非常有必要的。下文介绍了几种常用的物探方法,对其在具体的应用过程进行探讨,希望能为相关工作的开展提供一定的参考作用。     

选矿生产指标可视化监控平台研究

针对选矿工业过程流程长、工序多、生产指标多的特点,结合数据可视化及可视分析技术,开发一种选矿生产指标可视化监控组态平台。该平台包括生产工艺可视化组态设计环境、生产指标监控和可视及可视分析3个工具。组态设计环境支持以组态方式绘制工艺流程图,并能通过可视界面自定义生产工序的输入输出指标、触发事件、约束规则、工序状态属性、提示信息等;支持集成专家知识、经验和规则以实现基于知识的生产指标监控;提供算法配置接口,方便集成指标监控算法。其组态出的每一个工序都可以复用和扩展,可以构建选矿行业的基础工序单元组件库,形成选矿行业的知识积累。基于可视的工艺流程,利用指标监控工具为指标配置可视化方案,实现指标可视化监控。可视化方案由可视及可视分析工具提供,包括实时数据、历史数据及其统计特性、多指标综合对比分析、指标关联关系分析、多视图等可视方案。此外,为了提升工序指标监控效率和减轻操作人员监控强度,系统提供因子分析、Pearson相关分析、互信息、信息熵等分析手段,以辅助人们提取出工序关键监控指标,从而实现对监控生产指标的约简。由于该平台以组态方式提供,使其可以快速应用于其他流程行业,实现生产指标可视化监控的组态化。最后,该系统作为选矿生产执行系统的一部分成功应用到某选矿厂生产过程中,取得了良好的应用效果。